How to Improve Your Health Essay

Introduction Who wouldn’t want to know the recipe for good health? The mixture of healthy diet and physical activity helps the body’s system function better, reducing the risk of heart diseases, diabetes, between other diseases that cause death. To be healthy your body requires a balance of the consumption of the calories on your foods and drinks with your physical activity. Nowadays people are always in a hurry and they forget the importance of taking care of themselves. Most people are sitting at work or in front of the TV the whole day and since people don’t make enough time to prepare their food, all they can eat at a restaurant it is not exactly healthy food. You must understand that not taking care of what you eat and the physical activity you follow every day you are just harming your health and putting it at risk. Today I will speak about how to improve your health. Transition: So what can people do to improve their health? Body It is very important for everyone to take care of themselves. Our body is the  only place we have to live in and it needs for us to take care of it. A healthy diet and physical activity are two essential things to improve our health. I According to the Centers for Disease Control and Prevention, over 69.2% of the population is overweight; this is mainly for the lack of care and time that we put to ourselves. But people need to be committed to make a healthy change in their life to make a difference. A I completely understand that when people hear â€Å"Healthy Diet† they automatically associate it with something hard, almost impossible to do. So we can call it healthy eating habits, but it is easier to understand, the unhealthy foods you need to avoid, such as food with high saturated and trans fats, added sugars and high amounts of sodium which only raises your blood pressure. B You can start by doing changes in your diet, such as switching from whole milk to low fat milk o r fat free milk. Changing a drink loaded in sugar for a natural fruit juice, and avoiding white bread changing it for wheat bread. II If exercise and healthy eating improve your health, bad eating and a sedentary life does completely the opposite; causing overweigh and increases the risk of cancers. A According to the National Heart and Blood Institute over weight and obesity are the main causes of Heart Disease, strokes, type 2 diabetes, cancer, between many other health problems. B Health care professionals state that risk increases with a waist greater than 35 inches for women, 40 inches for men. The recommend diet to follow is rich in fruits and vegetables, whole grains, and fat-free and low-fat dairy products. It is very important to add fruit and vegetables to each meal because they contain many vitamins and minerals our body needs to lower the risk of diseases. III Balance calories from foods and drinks with physical activity are very important. Physical activity will help to lower the risk of heart diseases and cancers. A Exercise help strength your heart and help your lungs work better. It also strength your muscles and keep your joins in good conditions. It is recommended a minimum of 30 minutes of cardio a day. B You don’t necessary need to go to a gym, daily activities count too, you just need to make sure you are doing them to raise your heart rate. Walking the stairs instead of taking the elevator, or choosing a far parking space so you can walk to your destination, as well as washing your car are some  examples of daily activities that can help you. Conclusion I A balance diet and physical activity improves your chances of living longer and living healthier A Unhealthy eating and sedentary life lead to diseases B Healthy diet C Physical activity References U.S. Dept. of Health and Human Services. 2008 Physical Activity Guidelines for Americans. 2008. Centers for Disease Control and Prevention. (n.d). â€Å"Obesity and Overweight.† Nov 21, 2013. CDC/ National Center for Health Statistics. March 28,2014. Print. National Heart, Lung, and Blood. (n.d.). â€Å"What Are the Health Risks of Overweight and Obesity.† July 13, 2012. USA.gov. March 28,2014. Print.

Humanity Case Essay

Humanity.   Perhaps this is the only word that can explain the strange comings and goings of the man from Nazareth, called Jesus.   â€Å"The Lost Tomb of Jesus,† aired March 3, on the Discovery Channel, an amazing piece of documentary.   In the city of Jerusalem, in the midst of an apartment complex, was found a place of burial.   Perhaps the burial place of, Mary Magdalene, her son Judah, and two brothers-in-law, Simon and James.   Were these the relatives of Jesus the Christ, in the scheme of things the question seems to be irrelevant. Humanity   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Although there is great emphasis placed on the Christ, the Messiah.   Very few people seem interested at all in Jesus’ humanity.   People are offended at the thought that Jesus may have deigned to have been with a woman, much less married to a whore.   Yet this is the very story told in Hosea.   God’s unquestioning love of even, maybe most especially, one who would be unfaithful.   It seems to me of all of Jesus’ disciples, Mary is the one who ‘got it.’   Only an outcast could truly understand the message of Christ.   To be offered kindness, when only suffering has come at the hands of man, is an indescribable miracle.   How Mary must have loved this man, Jesus.   The Divine, the Christ.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Jesus’ humanity is controversial.   And I don’t know why.   If Jesus was not fully human, how could God come to know what it is to be human?   To struggle?   To be defeated?   To know unbridled joy?   To be shortsighted as man is and yet still have the ability to hope.   How God must love us for that!   Yes, ‘all have sinned and come short of the Glory of God.’   Who among us is not aware of their own shortcomings?   Everyone I know.   To be human is to be all to aware of what we are not.   Was that the purpose of Jesus’ coming?   To remind each of us of our all too familiar failures?   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚      Many others are outraged that anyone should question the Divinity of Christ, as though questioning such a thing changes the very nature of God?   Hardly.   What question could man possibly ask that could be found to be offensive to God?   Yet, this question of Divinity versus Humanity, people seem to struggle over.   Christ is all or none.   Even those who would say Jesus was both human and God, cannot admit that Jesus could have succumbed in his humanity to be human.   And what a terrible misrepresentation.   All throughout the Bible God is represented as part of humankind.   Why would humanity be denied what most Christians’ believe to be God’s only Son.   There is of course, great misrepresentation and misunderstanding about the chronology of the canon.    That Jesus’ divinity was not even declared until 300 years after his death.   By whom?   Why man of course?   I wonder if God would be pleased with all that the ‘church’, not the body, has accomplished?   Just recently, I visited a new church and although I liked the people.   I was saddened when the pastor started talking about the ‘building’ fund.   Is this what Christianity has been reduced to?   Buildings?   What of the starving?   What of the homeless?   What of the person who has not known the kindness of a human touch, due to illness or simple isolation?   What of these?   Does God not plague us to be in touch with his light, his life, his children?   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The Lost Tomb of Jesus is a wonderful representation of the possibility that Jesus was all he said he was.   A miracle.   A blessing in disguise.   Both human and Divine.   Just like the rest of us.   A bit of God rests in us all at the heart of God’s highest creation, mankind.   Rejoice!   Awake!   God is among us!   Living when we thought he was dead!   Alleluia!   Jesus is Alive!

Ethical Perspective: the Role of Social Media in Recruitment and Selection Essay

Ethical Perspective: The Role of Social Media in Recruitment and Selection â€Å"A† is a Bangladeshi holding company that conducts its business all over the world. The company aims to be recognized as a global brand and is currently in the process of expanding its operation. To achieve its goal of global expansion, â€Å"A† is looking to hire new executives who are young, energetic and outgoing. The executives should have good communication skill as they will have to correspond with potential clients from all over the world. They should also possess a likeable personality as their work will be people-oriented. The executives should be technologically competent as they may have to communicate online. Mr. Rahim is a senior manager who wants to use social media as a tool to collect more information about the potential recruits. He argues that, as the candidates themselves shared the information on public, it will be completely legal and ethical to use that information in their recruitment and selection process. Look more:  google recruitment process essay As the candidates themselves shared their personal information on a public website, it would not be a breach of privacy to use that information either. He also argues that, when people are asked to share information in a job interview, they are more like to only share the information that make them look good and conceal the information that make them look bad. Thus, the information collected from their personal Facebook, LinkedIn and Twitter accounts should help the company judge the candidate from an unbiased point of view. Mr.  Karim, another senior manager, is however against the use of social media to collect personal information. From his point of view, it will be an invasion of privacy to collect information from their social media accounts as the candidates intended their accounts for personal use. He also believes that the company should only use the information provided by the candidates themselves in the recruitment and selection process. He thinks that the data collected from social media sites are more likely to be biased as the candidates may not have been serious when posting them. He argues that although the potential recruits shared their personal information on a public website, they did not give them the permission to use it as a criterion to evaluate their job effectiveness. If this information relates to some aspect of a candidate’s background that could not be requested in an interview, such as age, cultural background, sexual orientation, etc, they could be contravening discrimination law. As the job requires good communicative skills, Mr.  Rahim believes that the company should look into the social media presence of their potential recruits. He argues, that if someone doesn’t have a social media account in this age, they are most likely to be backdated and quite incapable of working in a global company. Also, people who have more friends or followers in facebook and twitter are more likely to be outgoing. As the company is looking for outgoing people to join the organization, it should be a valid and reliable selection tool. Mr. Karim is strongly against this view. He argues that a person’s personality cannot be judged by looking at their social media profile. Just because someone has more friends or followers on social media sites, it cannot be said for certain that person has a more likeable personality. It will be unethical and discriminatory to exclude quality candidates just because they are not active on social media sites. Mr.  Rahim believes that people who post sexist, racist, homophobic remarks on facebook may damage the business reputation of â€Å"A†. Some international business partners of â€Å"A† may even stop doing business with them. So, â€Å"A† has every right to discriminate against employees who post controversial content on their social media accounts. People, who identify with extremist religious or political groups on social media sites, should not be selected as employees. Mr.  Karim argues people’s behavior on social media may not be a true reflection of their views. Just because someone appears sexist, racist or homophobic on social media, that doesn’t mean that that’s how they are in real life. Also, a person’s religious and political views are completely his own. It is certainly not ethical to judge a candidate simply based on what they do in their own time away from work. â€Å"A† cannot discriminate against potential candidates just because they shared their views strongly on social media sites.

Managerial Accounting for Decision Making Essay

Managerial Accounting for Decision Making - Essay Example Horngren and Sundem, 1990. P- 4’ (MACINTOSH & QUATTRONE. 2010) Management accounting system is a part of the larger control system in the organization used to measure, monitor and motivate the managers and employees in the organization and also to coordinate with the other components of the organization like machine, information, material and technologies etc. For a robust control system it is necessary for the entire control mechanism to support each other, management accounting system can play a great part in coordinating and controlling all the activities in the organization. (MACINTOSH & QUATTRONE. 2010) Management accounting system not only helps in planning and coordinating activities of the organization but also plays a vital role in performance measurement and decision making by providing information for managers to make timely decisions, to be effective and efficient in the execution of the business and to improve overall performance of the organization. ... between financial and management accounting for which one thinks that they both perform the same function like both are used in the reporting purpose and helps managers in analyzing the company’s performance and take action for control. But it’s important to mark the differences and benefits that management accounting can solely provide to the organization. Financial accounting is used at the end of the financial year when auditors come for the audit. They work on the historical data that how company performed during the year and prepare their report for the shareholders confirming company’s accounts give a true and fair view. Management accounting however is used to provide information for managers only on a continuous basis that is it doesn’t wait for the financial year to end. It is forward looking and focuses on information that managers can use to make decisions for the future. Therefore if company has issues and loopholes in the control and informati on systems it can be corrected right on time. Management accounting system in short makes the managers adopt a more forward looking approach for the business. (NEEDLES, POWERS & CROSSON .2010) Part A. 2. Identify from the case study the reasons why Tania thinks that Nosystem Limited should install a management accounting system Analyzing the case given it could be argued that Nosystem needs to install management accounting system. As Tania emphasized that Nosystem is a growing organization now there is a growing need for the planning, control and coordinating activities. By installing management accounting system Nosystem can plan its activities at all levels that is strategic, tactical and operational levels to achieve the ultimate goal and objective of the company mentioned in the mission statement. Further

Why Cristiano Ronaldo is a Hero Essay Example | Topics and Well Written Essays - 500 words - 7

Why Cristiano Ronaldo is a Hero - Essay Example The first aspect that makes him a hero is the fact that Cristiano Ronaldo does not take alcohol. This may not appear to be unusual since there are many people like him who still do not take alcohol. However, the only thing that makes him a hero, regarding this aspect, is his reason for not doing it. His father used to take alcohol and consequently was affected by a liver disease, which emanated from alcohol intake. Having a deep love for his father, who had inspired him much to the footballer that he is today, he made a decision that alcohol was not good and therefore he would not take it. This to me is a heroic deed, because the reason behind his decision was the love he had for his father and the bitterness of his death, which emanated from alcohol. Thus, it is a heroic decision, based on a real-life experience, which serves to indicate the love and appreciation he had for his father. Notwithstanding that he has a lot of money and access to alcohol, and even more temptations based on his social status, he resolved and stuck to that decision. This is a heroic deed that needs to be applauded. More to his heroic deed is the fact that he has reached yet another decision that is very rare. He is among the very few celebrities who do not have a tattoo on his body. It is not out of the fact that he is not interested in beauty and fashion. Neither is the decision to avoid tattoos on his body influenced by any religious, cultural or social belief. He resolved not to have any tattoos on his body since he likes donating blood frequently. This is yet another thing that makes him unique and a hero. He displays the possession of a heart that is willing to serve the plight of others, through saving their lives. While having avoiding tattoos on the body is a decision that can easily be reached by anybody, his reason for doing it makes him stand out.  Ã‚  

Pervasive Computing in Security Essay Example | Topics and Well Written Essays - 1750 words

Pervasive Computing in Security - Essay Example Authentication is the process of proving that you are who you say you are and establishing proof of identity. Authentication can be achieved through the use of passwords, smart cards, biometrics, or a combination thereof. People are the next most important security component. Often, people are the weakest link in any security infrastructure. Most corporate security relies on the password a user chooses. If the user chooses his or her first name as the password, the time, energy, and money spent evaluating, purchasing, and implementing security solutions go out the window. Numerous methods exist to gain access to a system. Social engineering preying on the weakest factor in any security infrastructure, the human-is one of the most successful methods. From pretending to be a helpdesk worker and asking users to change their passwords, to dressing up as the copy machine repair technician to gain physical access to a building, social engineering is effective in gaining access to an organization's systems. (Andress, 2003) Other methods include trying to guess username and password combinations and using exploits in operating systems and applications to gain access to systems. Some common exploits include buffer overflows, Windows exploits, and Web server application exploits. The most popular tool for information theft attacks is the network sniffer. With a sniffer, an attacker monitors traffic on a network, usually looking for username-password combinations. (Andres, 2003) The use of sniffers is known as a passive attack because the sniffer's snooping does not require any action on the part of the attacker. Active attacks, on the other hand, do require action. Examples of active attacks are "dumpster diving" or calling up an individual at a target company and asking for information. Security Awareness Security awareness can be provided at the utmost by conducting seminars and awareness campaigns. Such campaigns work well in explaining topics like password selection, screen locking, document labeling, and physical (door) security. Posters, e-mails, screensavers, and mouse pads printed with security tips and expectations help provide day-to-day reminders. Some companies even establish security incentive programs for their employees. Multifactor Authentication The three major types of authentication which are commonly used now a days are: Something you know-personal identification number (PIN), password. Something you have-SecurID, smart card, iButton. Something you are-that is, some measurable physical characteristic of you, such as fingerprints

What changes have enabled Michael Porter to see Procurement Essay

What changes have enabled Michael Porter to see Procurement (Purchasing) in a more strategic light - Essay Example Porter explains when a unique product is produced; a firm could have the advantage to set premium price for it, calling it as a differentiation advantage. In addition, he wants to point out there is competitive advantage earned when a firm could produce existing similar product offerings, but at lower cost. He calls this cost advantage. Today, most, if not all, firms require outsourcing almost everything just in order to provide or come up with service or product offerings. This can be clearly elaborated in the value chain, which at the bottom line, one would be able to realize the associated cost generated in production of certain product or service. In order to achieve cost advantage as Porter defines, it is therefore important to at least minimize or cut cost in order to produce offerings that would have competitive price. Procurement or purchasing is an important component in Michael Porter’s value chain model. In this model, he originally identifies procurement to be just a support activity. However, recently, he emphasises the potential strategic contribution of procurement to shared value, as published in the Harvard Business Review. Concerning Porter’s recent claim, this paper tries to present the existing trend to justify whether opportunities for purchasing to contribute more strategically have increased, and how it might have addressed relevant matters in the difficult economic conditions facing organisations today. Significant trending Purchasing together with its strategic importance has long been remarkably considered, but there was actually less appreciation of it when it comes to what it can actually do with business performance. Concerning this issue, a study with empirical analysis conducted on 141 industrial companies reveals interaction among purchasing efficacy (purchasing strategic objectives and capabilities) and strategic integration of purchasing (between business strategy and purchasing strategic objectives) (Benito, 2007 , p.901). Today, one essential point of understanding the actual strategic importance of purchasing can be viewed within the context of its actual contribution to business performance. So this goes with finding interesting stuffs about the likelihood of its contribution to creation of profit, customer satisfaction, increase market share and more. After all, business performance might include different metrics that could help measure and as bases of actual business growth. Regarding this, it has become a considerable point to constantly investigate purchasing using various empirical researches just to be able to quantify its actual significance as a strategic function. A recent study conducted to investigate the empirical contribution of purchasing and supply management (PSM) to the company’s success generated a substantial result based on the information gathered from the international survey of 306 major companies from eight industry sectors (Hartmann et al., 2012, p.22). Th e study showcases empirical evidence leading to the point PSM has remarkable contribution to the company success. The contributed value was found to be mediated by three operational performances such as cost, quality and innovation (Hartmann et al., 2012, p.22). PSM, increasingly regarded by senior management to strategically influence operational performance and financial performance, however, was found to still require external survey methodology that complements the internal perceptional measures of PSM performance, and a comprehensive performance measurement framework

Predatory Lending Practices Essay Example | Topics and Well Written Essays - 1500 words

Predatory Lending Practices - Essay Example When lenders began offering loans to deprived borrowers with low or bad credit standing, sub-prime loans were priced higher to compensate for the risk. Regardless of the a client's personal credit history, these finance companies offer the chance and allowance of refinancing or new mortgage that overwhelms he borrower with high fees and expensive often unhelpful terms. Minority borrowers composed of hard working people and low-wealth are the usual of consumers availing this type of loan to obtain financing. Availability of fair credit terms should be a major priority for responsible lenders as people no matter what the noted deficiencies are members of a civilized society with moral rights to uphold regardless of condition of credit orientation. However, seemingly cognizant of the needs of this minority sector, financing institutions have blossomed giving effect to what has been observed as a tragic loophole in Federal reserves that charges people with exorbitant interests and penalt ies. When the growth in equity lending has created risk management practices in response to financial institutions with equity lending programs, financial institutions' credit risk management practices for home equity lending have not kept pace with the product's rapid growth and easing of underwriting standards. We have seen numerous fore-closures on home properties in the past years that would eventually reflect in an economic meltdown. Further studies revealed predatory practices of lending institutions as the culprit in this scenario that charged exorbitant and often unnecessary fees and interests into the gross amounts that may no longer be viable for a medium to low wage earning homeowner. How can management eliminate the negative symptoms How can management fully capitalize on an opportunity Risk Management standards would create a favorable scenario over the increased lending with favorable tax treatments that may allow home equity loans and lines attractive to its consumers that offers a modest repayment schemes and relaxed structures that was currently devoid in its system. Institutions should capitalize on the rise on home values coupled with lower interest rates that make a product more attractive yet attainable and helpful to its user. The identification of certain risk factors in the system of practices in a financial lending institutions helps to identify the culprits that serves to practice certain features that offer an "interest-only" amortization that requires no principal amount applied. Documentation or its absence provides no room for evaluative measures and appraisals within the healthy structure. Risk management systems call for lending measures conducted in a safe and sound manner pursued with adequate allowances for loan losses and appropriate capital levels without negating sound practices in the accepted lending policies. Management principles actively assess the changes in the consumer's ability to pay and the potential decline of a home value and entertain this scenario without generating allowances that charge exorbitant fees disabling the capacity of the borrower from paying his dues and eventually leading to the

Activist Technical Geek and Sensitive Nature-Lover Research Paper

Activist Technical Geek and Sensitive Nature-Lover - Research Paper Example Secondly, no one had described the design of a search engine, in an academic way before (Brin and Page), so, unlike other disciplines, the knowledge was not shared by a scholarly community. That makes it more difficult to advance knowledge because there is limited opportunity for dialogue. To address the second problem, he wrote and published a very careful academic description, in great detail (Brin and Page), so that the knowledge could be shared and later advanced. Third, he needed to decide how to handle the additional information in hypertext and how to prioritize it, since anyone can write anything and put it on the web (Brin and Page). There needed to be a way to sort out the opinions of the uninformed from the research of top scholars. Also, there should be a way to respond differently to people looking for articles and people looking for pictures. To address the third problem, Google contained priority and category levels. Google Scholar, for example, brings up academic articles and citations, while Google Images brings up pictures and cartoons, and Wikipedia falls under a general web search category. Therefore, I see that this man is not just a technical geek but is a sensitive, fully engaged person. I think this is the key to understanding him. Yes, his brilliance and vision resulted in Google, but he was more than that. He set an example of how Google can create community and connect people in their experience of each other.   He is a very committed person and this is reflected in his professional life and in his personal life.

Attitudes Towards Jewish Migration to Australia in the 1930s Essay Example for Free

Attitudes Towards Jewish Migration to Australia in the 1930s Essay Describe and account for attitudes towards Jewish migration to Australia in the 1930s (distinguishing between political and public attitudes). Did Australian policy towards Jewish refugees change significantly during and after war from what had prevailed in the 1930s? How would you explain the policy continuity or change? Throughout the 20th Century, the policy adopted by Australia towards Jewish migration can best be described as one of restriction and limitation. Australian political and public attitudes during the 1930s were influenced by fears of the Jewish community’s inability to assimilate into Australian culture, the threat that they may have posed on job security and standards of living as well as the potential for their arrival to stimulate extreme anti-Semitism problems within Australia. The outbreak of war and the publication of Jewish persecution in Europe did little to alter the feelings of insecurity towards Jewish communities in Australia. While there were some attempts to increase the arrival of Jewish people after World War II, the sentiment of the majority of the Australian population remained unchanged and restrictions on immigration were still enforced. This theme of underlying racial prejudice continued to shape Australian policy throughout this entire period. During the 1930s, it is evident that the Coalition Government, comprised of the United Australia Party and Australian Country Party, made attempts to restrict the immigration of Jews into the country. First and foremost, the recent Australian struggle through the Depression meant that the Government was intent on protecting the job security and living standards of the Australian populace. The migration of any foreign immigrants was therefore unpopular due to the threats it placed on the Australian worker. This policy became an excuse for limiting the number of Jewish refugees accepted into Australia and resulted in an increase of the amount of landing money required to five hundred pounds for alien immigrants. This requirement was difficult for the majority of Jewish refugees to satisfy, making their entry into Australia virtually impossible. This policy remained in place until 1936 when the amount required was reduced to two hundred pounds or fifty pounds with a guarantor. Due to the poor economic conditions that had been experienced in Australia throughout the 1930s, the Government was reluctant to increase Jewish migration when so many of the migrants were impoverished, meaning that they would place a further strain on the Australian economy. The Government was also reluctant to permit the entry of a significant number of Jewish refugees due to the belief of their inability to assimilate into Australian society compared with some other cultures. The Government believed that the Jews were a separate race due to their distinctly different religious beliefs and customs and that this would significantly inhibit their assimilation into the Australian population. Australia’s political attitude towards Jewish migration was made clear at the Evian Conference, a meeting for the discussion of Jewish refugees, in June 1938. Australia realised the importance of attending the meeting so as not to gain a bad reputation, however the outcome showed that the Government was unwilling to increase the number of Jewish immigrants into the country. At this international meeting, the Australian representative Colonel T. W. White stressed the idea that Australia did not suffer from internal racial problems and its desire to maintain these peaceful conditions meant that allowing ‘undesirable’ migrants into the country was not an option. Colonel White also made it clear that the Australian Government felt that as a young nation, the importance of maintaining a strong connection with its Anglo-Saxon roots was vital for the growth of the Australian population. At the conference, the nations present most often put forward the case that they had already done what they felt was enough in response to the refugee crisis without undermining the standards of living within their own countries. It was felt however, that due to the vast amounts of free space and low population compared to some other nations, Australia should take a greater role in accepting refugees as the economy would not be as degraded and these refugees had the potential to provide workers needed in primary and secondary industries. Despite the prevalence of this resistance to Jewish migration, it is evident that there was at least one politician who pushed for the Australian Government to accept more refugees. Stanley Bruce, a former Australian Prime Minister who moved to London and became the Australian High Commissioner to the United Kingdom was well known on an international platform due to his appearance at numerous world conferences and meetings as an Australian representative. He pressed for Australia to take a more humanitarian approach to the issue of refugee migration, especially after the Kristallnacht in Germany and Austria in November 1938. He appealed for the Government to increase its quota to 0,000 refugees over a three year period, thereby doubling the 15,000 quota suggested by the Australian Government. With a large increase in the number of applications being made to Australia House for entry into Australia after the Kristallnacht, this number seemed reasonable to Bruce. Instead it was decided in December of 1938 that Australia would accept 15,000 refugees over three years. In comparison with the number of refugees that had been accepted over the past five years, this was a significant increase, however not enough to satisfy the humanitarian plight of Bruce. It is also evident that this quota was never reached as the outbreak of war in 1939 saw the termination of immigration and by this time only 7-8,000 refugees had been accepted into the country. While the Government was developing its policy regarding migration during the 1930s, politicians were under a significant amount of pressure from the Australian public to limit the growth of the Jewish population in Australia. Interestingly, this sentiment was felt from groups in both non-Jewish and Jewish communities in Australia. The Australian Jewish community were opposed to the large influx of Eastern European Jews due to the difference in language spoken which they felt would make it difficult for them to assimilate easily into Australian society with the help of the already established Jewish community. Another fear was that due to the impoverished state of the Jewish refugees, the Australian Jewish community would be burdened by the arrival of the poor refugees and thus their status within society would be diminished. It was also hard to convince the majority of the Australian populace of the benefits of a large migrant intake. It is evident that many Australians felt that the Jewish population would undermine the standards of living as well as pose threats to the security of their jobs, a prominent issue after the hardship of the Depression. There was belief that the Jews were far too distinguishable from the normal ‘Australian way of life’ through the way they dressed, their general behaviour and their religious customs. This sentiment was particularly strong amongst religious groups within Australia. For example a particular Anglican group felt that the Jewish community should not be welcomed on a large scale as their beliefs would challenge the traditional Christian teachings of many Australians. It was also feared that the establishment of a larger Jewish community in Australia may lead to the development of a strong anti-Semitic . movement within Australia. The Australian community was aware of the problems this had created in other nations and was fearful that the same problem would face Australians. Therefore, the preference of the public was for the migration of smaller numbers of Jews, as it was felt they could be more easily assimilated into Australian culture this way. The public resistance to migration was further evinced by the fact that members of the public made requests to the Government to create specific application requirements and toughen selection procedures in order to restrict the numbers of migrants who were able to meet these requirements. Throughout this period Australians were unaware of the atrocities that were to follow during the war period and so their priorities lay with the protection of the economy, maintaining standards of living and ensuring peaceful relations between members of society. Despite this widespread public sentiment, there was some pressure from the media to increase Jewish migration for humanitarian reasons. The Sydney Morning Herald and the West Australian both stressed the need to make a larger contribution to the refugee problem and expressed that Australia was in fact not doing enough to assist the refugees. It is also evident that within some professions, there was encouragement of refugee migration, for example some architects in New South Wales welcomed the arrival of Jewish migrants with an architectural background as they had the potential to bring with them new ideas and thus add to the cultural identity of Australia. However, such opinions were in the minority and there is increasing evidence that the majority of Australians, along with their political counterparts, were sceptical of the Jewish arrival and wished for only particular migrants to be allowed into the country that were non-intrusive and therefore able to assimilate easily. While Jewish migrants that entered Australia during the 1930s did their best to quickly assimilate into Australian society, the outbreak of war in 1939 prevented this from occurring as once more Jewish migrants were seen as aliens who threatened the security of Australia. Throughout the first few months of the war, newspapers around Australia detailed some of the atrocities occurring in Europe against the Jewish population. However by 1940 the large publication of this murderous activity had declined significantly. While the papers still published stories about the treatment of Jews in Europe, the Australian public was largely unaware of the extent of the persecution. With the world at war, Australians were fearful of people who had previous ties with Germany and the Nazis and therefore refugees were termed ‘enemy aliens’. In Britain this led to harsh internment policies of these potential spies, however in Australia the internment policy was more relaxed. It is evident however that even if the refugees were not interned during the war period they were often treated with hostility by other Australians. Jewish communities in Australia also had to deal with frequent police checks and restraints on their freedoms, such as the ability to own a radio. There is evidence to suggest that post-war attitudes to Jewish persons in Australia in many respects mirrored those of the pre-war years. After the direct attack on the Australian mainland during the second half of World War II, Australian Government policy was directed towards increasing the population so as not to leave the vast unoccupied lands in Northern Australia unprotected. For the first time, Australia began to look further than Britain for prospective migrants, although it is apparent that regardless of this, Jewish migration was still looked upon unfavourably. After World War II, both of the major political parties shared a similar view in relation to Jewish migration; that the emphasis should be placed on the arrival of British migrations in preference to any others. The newly appointed Minister for Immigration, Arthur Calwell’s policy in the early post-war years implied a restriction on Jewish migration. While he had introduced a family reunion scheme in which 2,000 survivors of the Holocaust could be united with family in Australia, this only lasted for a period of twelve months, after which time limitations on Jewish migration were increased. One such example was the limitation of the number of Jewish migrants per ship arriving in Australia to 25% of the total number of people travelling on the ship. The Liberal party policy under the Opposition leader Robert Menzies followed along the same lines as the pre-war policy in that Jewish migration should be kept at a minimum due to the potential for extreme anti-Semitism to develop in Australia and the impact that the migrants may have on Australian standards of living. Under the direction of Calwell, migrants were accepted through the Displaced Persons Scheme. Under this scheme there were 34,890 arrivals into Australia in 1946, of which only 187 were Jews. Of these 187 Jewish arrivals, only 156 were permanent migrants. This is an incredibly low number given the large number of Jewish people that would have been seeking respite after the end of the Holocaust in Europe. A statement regarding the migrant intake in 1946 by Calwell expressed his feelings that the Australian Government had done all that it could at the present time to assist with the post-war refugee problem. He also expressed that the Government was only able to accept refugees that already had family living in Australia with whom they could settle with due to the housing shortage being experienced at the time. The post war attitude of the Australian public towards Jewish migration attitude was also reminiscent of the 1930s period. Australians had developed a fear of foreigners after their close encounter with the Japanese during the second half of World War II. This insecurity led them to believe that Jewish migrants would smuggle opium into the country. The Jews were also criticised for their preference to establish communities within the city as opposed to rural areas where Australians thought migrants would make a more significant contribution to the development of the nation. There were numerous newspapers and magazines which circulated negative opinions towards the post-war migration of Jewish persons to Australia. For example an excerpt from the Bulletin in August 1946 detailed the feelings of many Australians at this time that Jewish migrants should be some of the last ethnic groups considered due to the tendency for them to form ghettoes and compete with Australians for jobs. One public attitude that did change was that of the Australian Jewish community. Instead of looking towards the Jewish refugees as a threat to their social status, after the horrors of the Holocaust, many people were keen to provide as much assistance as possible to the survivors. Therefore the Australian Jewish community were supportive of the Government’s family reunion programme and the seemingly humanitarian plight of Arthur Calwell at this time. Under increasing pressure from the public and other members of Government, Arthur Calwell’s humanitarian position on Jewish migration was changed to restrict Jewish immigration. From 1947 onwards the refugee immigration program ceased to exist and so the ability to migrate to Australia was determined by the suitability of the person for employment in Australia. This change in policy made it increasingly difficult for Jewish people to migrate to Australia as Peter Witting found when he and his family applied to leave Shanghai for Australia in 1947. It is also evident that the Australian Government made false claims that acceptance decisions were made without racial prejudice when the selection committee of the International Refugee Organisation in Australia were secretly told to select only migrants of Baltic background, thereby excluding Jews once again. Overall, it can be seen that Australia’s attitudes towards Jewish migration followed a similar pattern from the 1930s through to the immediate post-war years. The underlying feelings of Australians throughout this period were of anxiety, apprehension and hostility which ultimately impacted on the attitude of Australia towards migrants. The restrictions placed on migration in the 1930s via the quota system and high landing permit costs through to the opinions displayed at the Evian Conference portrayed an image that suggested an Australian fear of Jewish people. These feelings were motivated by the fear of the rise of anti-Semitism in Australia and threats to the security of Australian jobs and standard of living that the public and government believed Jewish migration would pose. These tensions remained during the war when the Government placed restrictions on the freedoms of Jewish people, who were considered a threat to the security of Australia. During the post-war period, despite the fact that there was some effort to increase the numbers of Jewish people entering Australia through Government policy and the support of the Jewish Welfare Society in Australia, the Australian public remained sceptical of the arrivals and the effects they would have on society. The further restrictions placed on Jewish migration after 1946 indicates that minimal changes to political and public opinion were evident over time and that racial prejudice against Jewish migrants still existed after the events of World War II.

Effect of Adolescent Cannabis Use on Brain Functions

Effect of Adolescent Cannabis Use on Brain Functions Cannabis Use During Adolescence: A Review of Impacts on Brain Functions and Associated Outcomes Recent years have seen a dramatic increase in the social acceptability of cannabis usage in the United States, with several states having already legalized recreational use of the substance and several more projected to do so within the next several years (Leyton, 2016).   Concurrently, there has been an increase in the amount of adolescents who report using cannabis, with recent data indicating that 39% of high school seniors report using cannabis within the past year and 6-7% reporting daily or near daily cannabis use (Johnston & O’Malley, 2015).   Despite increasing utilization of cannabis products for pain management and other ailments (Hwang & Clarke, 2016), some in the scientific community have expressed concern about the potential ramifications of recreational legalization of cannabis.   Chief amongst these concerns is the idea that adolescents will have very easy access to increasingly potent cannabis and synthetic cannabis products (Sobesky & Gorgens, 2016), as a great deal of research has indicated that the use of cannabis poses several risks specific to individuals in the adolescent age range (see Levine, Clemenza, Rynn, & Lieberman, 2017).   This paper will summarize the research examining the impact of cannabis use on the developing adolescent brain and potential associated outcomes, particularly in the areas of cognition/executive function, anxiety and depression, psychotic disorders, and future substance use/dependence.   The Adolescent Brain To understand the impact of cannabis use on the developing adolescent brain, it is first necessary to understand the changes taking place in the brain during this developmental period.   Not surprisingly, the period of adolescence is a time of tremendous change in the circuitry of the brain.   According to Arain et al. (2013), there is a significant amount of neuronal plasticity in the brain during adolescence, meaning the â€Å"wiring† of the brain is extremely adaptable to learning and experience.   Such plasticity, particularly in the prefrontal cortex, lends itself to difficulty thinking rationally and critically, often leading to the impulsive decision-making that is characteristic of the adolescent years.   In addition, the hypothalamic pituitary adrenal (HPA) axis, the system responsible for regulating human responses to stress, also undergoes significant development during the period of adolescence.   Within this system, the amount and duration of adrenocorti cotropic hormone (ACTH) and glucocorticoids released in response to stress increase significantly as compared to other life periods (Romeo, 2013).   Shortly before puberty, a â€Å"surge† of synaptogenesis and neuronal growth occurs in which grey matter in the brain thickens substantially.   From this point throughout the period of adolescence, the brain is continually rewired through dendritic pruning and increased myelination of synapses, particularly in the prefrontal cortex (Arain et al., 2013; Lubman, Bonomo, & Yucel, 2007).   In addition, white matter increases are seen in the corpus callosum (Arain et al., 2013).   Taken together, these changes increase the efficiency of communication within the brain, allowing for the eventual development of more complex cognitive functioning, including improved impulse control, operational thinking, and working memory (Hart, 2007; Lubman et al., 2007).   In addition to the constant rewiring of brain circuitry that occurs during adolescence, the levels of three neurotransmitters – dopamine, serotonin, and melatonin – change during the adolescent period (Arain et al., 2013).   According to Dahl (2003), dopamine and serotonin levels decrease during adolescence, resulting in emotional dysregulation, mood disruptions, and difficulties with impulse control.   Melatonin levels, on the other hand, increase, which in turn increases the amount of sleep that adolescents need to be fully â€Å"re-charged.†Ã‚     Given the massive changes that are occurring in the brain during the period of adolescence, it is a time in which the brain is especially susceptible to the use of substances, (Lubman et al., 2007) including cannabis.   Cannabis’ Action in the Brain Before discussing the specific impacts of cannabis use on the adolescent brain, it is important to understand how cannabis acts in the brain in general.   First, the brain has an endogenous cannabinoid system (endocannabinoid system) made up of the ligands anandamide and 2-arachidonoyl glycerol (2-AG) and cannabinoid receptors known as CB1 and CB2 receptors (Moreira & Lutz, 2008).   CB1 receptors are located throughout the brain, but are particularly populous in the front region of the cerebral cortex, the basal ganglia, the cerebellum, the hypothalamus, the anterior cingulate cortex, and the hippocampus; CB2 receptors are generally found throughout the body’s immune system (Hill et al., 2010; Iversen, 2004).   The endocannabinoid system plays a role in a number of processes, including the regulation of the HPA axis stress response (Hill et al., 2010; Lee & Gorzalka, 2015), neural plasticity, and learning and memory (Lu et al., 2008).   According to Iversen (2004), the psychoactive component in cannabis is Δ9-tetrahydrocannabinol (THC).   THC, as well as increasingly popular synthetic cannabinoids, act as agonists on CB1 cannabinoid receptors in the brain.   Because CB1 receptors are generally presynaptic rather than postsynaptic, cannabinoids control the release of certain neurotransmitters, including acetylcholine, L-glutamate, ÃŽ ³-aminobutyric acid (GABA), noradrenaline (norepinephrine), dopamine, and 5-hydroxytryptamine (5-HT).   The use of exogenous cannabinoids, such as marijuana or synthetic marijuana products, leads to an unnaturally long-lasting activation of CB1 receptors, ultimately inhibiting the release of the aforementioned neurotransmitters in selected areas of the brain (Iversen, 2004).   In addition to its impact on CB1 receptors and associated neurotransmitters, THC also appears to trigger the firing of dopaminergic neurons in the ventral tegmental area of the brain and the nucleus accumbens – areas of the brain that are heavily implicated in the brain’s reward circuit associated with drug use.   This effect is also seen with heroin, cocaine, amphetamines, and nicotine, suggesting that THC may also act on the opioid receptor system within the brain (Iversen, 2004). Impact on Cognition and Executive Function Tasks The literature has focused on several larger areas of impact regarding cannabis use during adolescence, one of these being the potential impacts on cognition and tasks of executive function.   As previously mentioned, the brain undergoes a significant amount of change in the adolescent years, including the frequent re-wiring of neural connections through neural pruning processes, particularly in the prefrontal cortex.   According to Filbey, McQueeny, DeWitt, and Mishra (2015), cannabis use during adolescence disrupts this normal pruning process through its modulation of neurotransmitters and inhibition of microglial processes.   This results in abnormal connectivity within the brain, including a decrease in white matter volume and integrity (Gruber, Dahlgren, Sagar, Gonenc, & Lukas, 2014; Jacobus et al., 2009). Such changes result in a number of cognitive impacts, including increased impulsivity, poorer reaction times, and increased errors on executive function tasks (e.g., planning, organization, self-regulation, etc.) (Becker, Wagner, Gouzoulis-Mayfrank, Spuentrup, & Daumann, 2010; Gruber et al., 2014).   Indeed, studies have indicated that individuals who begin marijuana use in early adolescence are at an increased risk for developing deficits in attention (Ehrenreich et al., 1999) and visual processing (Tapert, Granholm, Leedy, & Brown, 2002), and exhibit a decreased full scale IQ and verbal IQ in adulthood (Meier et al., 2012).   Memory also appears to be affected by adolescent-onset cannabis use (Tait, Mackinnon, & Christensen, 2011), likely via its impact on the hippocampus – a part of the brain heavily implicated in memory functions.   Animal research has shown that the hippocampus is affected by cannabis use especially during the period of adolescence.   In rats, adolescent exposure to cannabis impacted the microstructure of the hippocampus as well as abnormalities in the way that proteins are expressed in the hippocampus (Quinn et al., 2008).   Specifically, it appears that exogenous cannabinoids bind to CB1 receptors and inhibit the release of glutamate, thus contributing to deficits in short-term memory (Hart, 2007) and negatively impacting performance on memory-related tasks (see Levine et al., 2017).   Some animal studies indicate that lower levels of cannabis use (those most reflective of the actual amount that adolescents use) are not predictive of long-lasting hippocampal changes.   However, because current cannabis products are continuing to increase in potency (Levine et al., 2017), hippocampal changes and subsequent memory problems are topics of concern, especially with regard to adolescent users of cannabis.   Working memory also appears to be impacted by cannabis use, particularly in individuals that began using cannabis before the age of sixteen.   Becker et al. (2010) used functional magnetic resonance imaging to examine performance on a working memory task in individuals who began using cannabis before age sixteen (early-onset) as compared to individuals who began using cannabis after the age of sixteen (later-onset).   Results of this study indicated that early-onset cannabis users exhibited increased cortical activity in the parietal lobe as compared to later-onset cannabis users.   The researchers concluded that this increased cortical activity indicated decreased cortical efficiency in response to challenging working memory-related tasks in early-onset, but not later-onset, cannabis users (Becker et al., 2010).   Such findings are consistent with a number of studies indicating that an earlier age of onset of cannabis use is associated with greater risk of negative impacts on cognitive functioning during adulthood (Ehrenreich et al., 1999; Fontes et al., 2011; Meier et al., 2012; Pope et al., 2003).   Impact on the Development of Anxiety and Depression Several studies indicate a connection between adolescent-onset cannabis use and the development of both anxiety and depressive disorders (e.g., Brook, Rosen, & Brook, 2001; Degenhardt et al., 2013; Fairman, 2015; Hayatbakhsh et al., 2007; Patton et al., 2002; van Laar, van Dorsselaer, Monshouwer, & de Graaf, 2007).   Though past researchers have speculated about the directionality of this relationship, studies have consistently indicated that adolescent-onset depression is not predictive of later cannabis use (e.g., Degenhardt, Hall, & Lynskey, 2003; Moore et al., 2007; Womack, Shaw, Weaver, & Forbes, 2016), negating the idea that depressive and/or anxiety symptoms lead to engagement in cannabis use as a method of symptom relief.   Instead, such findings promote the idea that cannabis use during adolescence, in combination with other potential risk factors, increase the risk for the development of anxiety and depressive symptoms in adulthood (Levine et al., 2017).   As with the cognitive changes discussed in the previous section of this paper, it is early-onset use of cannabis that appears to be riskiest with regard to the development of future anxiety and depressive symptoms (Hayatbakhsh et al., 2007; Patton et al., 2002).   In an interesting study by Spechler et al. (2015), fMRIs were used to examine activity in the amygdalas of adolescent users of cannabis.   The researchers showed participants images of both angry and neutral faces, a well-known test of amygdala activity and a well-regarded index of emotional processing.   Results of this study indicated that compared to the control group, adolescent cannabis users exhibited increased amygdala activity in response to the images of angry faces whereas the control group showed the same amount of amygdala activity when shown images of neutral faces.   Spechler et al. (2015) concluded that adolescent cannabis use is associated with increased hypersensitivity to negative affect.   However, in this case, the directionality of the relationship is unclear: it is possible that the sensitivity of the amygdala pre-dated the cannabis use and the cannabis use was engaged in due to its anxiolytic effect.   Conversely, it is possible that cannabis use led to increased sensitivity in the amygdala.   Either way, it appears that adolescent cannabis users are overly sensitive to negative affect and the potential threat that accompanies it, which may explain the increased incidence of depressive and anxious symptomatology in this population.    There are several potential neurobiological mechanisms explaining the relationship between adolescent cannabis use and the development of anxiety and depressive symptoms.   One possibility is the impact of exogenous cannabinoids on the HPA axis system.   The endocannabinoid system regulates the responsivity of the HPA axis, which, as previously mentioned, undergoes significant development during the adolescent years (Hill et al., 2010; Lee & Gorzalka, 2015; Romeo, 2013).   Studies with both human and rodent subjects have indicated that the use of exogenous cannabinoids during adolescence has the capacity to alter HPA axis stress responses, thus impacting emotionality and the development of anxiety-related symptoms (Lee & Gorzalka, 2015).   Lovelace et al. (2015) discuss another neurobiological mechanism that may underlie the relationship between adolescent cannabis use and the development of anxiety and depression.   In a rodent study, these researchers examined maladaptations in the prefrontal cortex due to cannabis use by looking at presynaptic plasticity at glutamatergic synapses in adolescent rats.   The results indicated that exposure to exogenous cannabinoids during adolescence led to over-activation of CB1 receptors, which led to permanent changes in synapses in the prefrontal cortex.   Overall, mice exposed to exogenous cannabinoids during adolescence showed a loss of presynaptic plasticity, which impacts the brain’s ability to adapt to changing environments and thus may contribute to an increased vulnerability of psychopathology during adulthood (Lovelace et al., 2015).   In an interesting rodent study conducted by Rubino et al. (2008), researchers found that exposure to THC during adolescence was associated with decreased density and function of CB1 receptors in the ventral tegmental area, the nucleus accumbens, and the amygdala.   These areas of the brain are implicated in emotional processing and reward and are thus implicated in the development of depressive symptomatology.   The behavior of the rats in this study also mirrored depressive symptomatology.   Specifically, rats exposed to THC during adolescence exhibited both â€Å"behavioral despair† (which the researchers defined as time the rats were immobile) and anhedonia (as measured through decreased consumption of sucrose).   Taken together, it appears that several neurobiological mechanisms are at play in the connection between adolescent cannabis use and the development of anxiety and depressive symptoms.   Impact on the Development of Psychotic Disorders A substantial body of literature has indicated a connection between the use of cannabis during adolescence and the later development of psychotic disorders (e.g., van Os et al., 2002; Henquet et al., 2005; Stefanis et al., 2004).   This is especially true for individuals who are already genetically predisposed to develop psychotic disorders (Henquet et al., 2005) though the connection has also been found in individuals that do not have this genetic predisposition (van Os et al., 2002).   As with the impact on cognition and on anxiety/depressive symptoms, it appears that early-onset cannabis use (Arseneault et al., 2002; Moore et al., 2007) as well as heavier (i.e. daily or near-daily) use pose the greatest risk for the later development of a psychotic disorder (Moore et al., 2007; van Os et al., 2002). Rubino and Parolaro (2014) discuss the possible neurobiological mechanisms behind the connection between adolescent cannabis use and the development of psychotic disorders.   In general, it appears that the use of exogenous cannabinoids during adolescence disrupts the maturational processes occurring in the brain during this time, especially in the hippocampus and the prefrontal cortex – two areas of the brain that are implicated in the psychotic disorder schizophrenia, in particular.   The endocannabinoid system itself undergoes a significant amount of change during the adolescent years; thus, exogenous cannabinoid exposure during this time period has the potential to alter the long-term functionality of CB1 receptors, which then impacts the activity of several neurotransmitters implicated in psychotic symptomatology, especially dopamine (Rubino & Parolaro, 2014). Additionally, being exposed to cannabis during the adolescent period has been shown to disrupt prepulse inhib ition (the ability to accurately perceive and process stimuli) and down-regulate GABAergic activity in the prefrontal cortex – both symptoms commonly seen in individuals with schizophrenia (Morales-Muà ±oz et al., 2014; Zamberletti et al., 2014).  Ã‚   As previously mentioned, individuals who have a genetically predisposed vulnerability to develop psychotic disorders are at an especially high risk to do so if they engage in cannabis use during adolescence (Henquet et al., 2005).   For example, individuals who have a specific variant of the gene for catechol-O-methyltransferase (COMT), which breaks down dopamine – the neurotransmitter implicated in schizophrenia – are at a much higher risk for developing the disorder if they used cannabis during adolescence as compared to individuals who do not have that specific variant of the gene for COMT (Caspi et al., 2005).   Another gene that influences the relationship between adolescent cannabis use and psychosis is the ATK1 gene, which affects dopamine breakdown in the striatum.   According to DiForti et al. (2012), cannabis users with a certain variant of the ATK1 gene were seven times more likely to develop psychosis as compared to individuals with this gene variant w ho did not use cannabis.   Clearly, in individuals that already possess these specific genetic variants, cannabis use during adolescence can be the trigger that leads to the expression of these genes and the development of psychotic symptoms and/or disorders.   In addition, adults with psychotic disorders who used cannabis during adolescence are at a greater risk for relapse of psychotic symptoms, poorer adherence to treatment, and increased rates of hospitalization related to their diagnosis (Hunt, Bergen, & Bashir, 2002; Lewis, Tarrier, & Drake, 2005; Wade et al., 2006).   Impact on the Future Development of Substance Use Disorders   Several studies have indicated a link between adolescent cannabis use and the later development of a substance use disorder.   Again, this relationship is especially strong for individuals that engage in cannabis use in early adolescence and who engage in heavy (i.e., daily or near-daily) use (Fergusson, Boden, & Horwood, 2006; Hall & Lynskey, 2005; Stuart & Green, 2008).  Ã‚   Past researchers have speculated upon various explanations for this trend, including the so-called ‘gateway hypothesis.’   In general, the ‘gateway hypothesis’ assumes that individuals who use â€Å"harder† drugs such as heroin and cocaine almost always started their use of substances with using cannabis, and that this link is explicitly causal (Van Gundy & Rebellon, 2010).  Ã‚   This hypothesis is based on research findings indicating that the use of cannabis during adolescence often predates the use of other illicit substances, including heroin, methamphetamines, and cocaine (Fergusson et al., 2006).   Though the causality of this link has been repeatedly questioned in the literature (e.g., Morral, McCaffrey, & Paddock, 2002; Van Gundy & Rebellon, 2010), many researchers have attempted to explain the mechanisms behind the early use of cannabis and the later use of other substances and/or development of a substance use disorder.   There are countless potential psychosocial explanations for this connection (e.g., peer pressure, propensity toward risk-taking behaviors, availability of substances, etc.); however, for the purposes of this paper, the potential neurobiological mechanisms behind the connection will be discussed. The major possible neurobiological mechanism behind the connection between early cannabis use and the later development of a substance use disorder has to do with the effect of cannabis on the brain’s opioidergic system.   A great deal of animal research has indicated that the endocannabinoid system and the opioidergic system are intricately linked.   For example, Pickel, Chan, Kash, Rodriguez, and Mackie (2004) and Rodriguez, Mackie, and Pickel (2001) found that CB1 receptors and  µ opioid receptors are found on the same neurons in both the striatum and the ventral tegmental area, and Cossu et al. (2001) and Ledent et al. (1999) found that animals without CB1 receptor genes do not self-administer opioids. Drawing upon this clear connection between the endocannabinoid and opioidergic brain systems, Ellgren, Spano, and Hurd (2007) investigated the hypothesis that cannabis exposure during adolescence changes opioid-related neural functions and leads to increased likelihood of later opioid use.   Findings of this research confirmed that rats exposed to THC during the adolescent period self-administered greater amounts of heroin compared to the control group.   Moreover, findings indicated that rats exposed to THC in adolescence showed a persistent disturbance in the activity of enkephalin, which is the endogenous opioid neuropeptide associated with reward behaviors and hedonic states.   Findings also indicated that THC exposure led to changes in the functions of  µ opioid receptors such that heroin use was more reinforcing (via dopamine release) for rats exposed to THC during adolescence as compared to the control group.   Taken together, these results indicate that cannabis use during adolescence leads to a greater vulnerability to the reinforcing effects of opioids during adulthood, potentially leading to a greater risk for dependence and likelihood of relapse of substance use disorders.   Conclusion Despite the increasing popularity of cannabis use, both for medicinal and recreational purposes (Hwang & Clarke, 2016; Leyton, 2016), it is important to consider the resulting increased availability of cannabis to individuals during the sensitive period of adolescence.   Given the profound changes occurring in the brain during adolescence (Arain et al., 2013; Dahl, 2003; Hart, 2007; Lubman et al., 2007), teenagers are particularly susceptible to the influence of substances, which may lead to lasting changes in the brain’s functioning.   Such changes are associated with poor outcomes in several areas, including deficits in performance on executive function tasks (Becker et al., 2010; Ehrenreich et al., 1999; Fontes et al., 2011; Gruber et al., 2014; Meier et al., 2012; Pope et al., 2003; Tapert et al., 2002), an increased risk for the development of anxiety and/or depressive symptoms (Brook et al., 2001; Degenhardt et al., 2013; Fairman, 2015; Hayatbakhsh et al., 2007; Patt on et al., 2002; van Laar, van Dorsselaer, Monshouwer, & de Graaf, 2007), an increased risk for the development of a psychotic disorder (Arseneault et al., 2002; Caspi et al., 2005; DiForti et al., 2012; Henquet et al., 2005; Moore et al., 2007; Rubino & Parolaro, 2014; Stefanis et al., 2004; van Os et al., 2002), and an increased risk for future substance use/dependence (Fergusson et al., 2006; Hall & Lynskey, 2005; Stuart & Green, 2008).   Such considerations may have important implications for policy development related to the legalization of cannabis.   References Arain, M., Haque, M., Johal, L., Mathur, P., Nel, W., Rais, A., Sandu, R., & Sharma, S. 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S., Morgan, C., Powell, J., & Murray, R. M. (2012). Confirmation that the AKT1 (rs2494732) genotype influences the risk of psychosis in cannabis users.  Biological Psychiatry,  72(10), 811-816. doi:http://dx.doi.org/10.1016/j.biopsych.2012.06.020 Ehrenreich, H., Rinn, T., Kunert, H. J., Moeller, M. R., Poser, W., Schilling, L., Gigerenzer, G., & Hoehe, M. R. (1999). Specific attentional dysfunction in adults following early start of cannabis use.  Psychopharmacology,  142(3), 295-301. doi:http://dx.doi.org/10.1007/s002130050892 Ellgren, M., Spano, S. M., & Hurd, Y. L. (2007). Adolescent cannabis exposure alters opiate intake and opioid limbic neuronal populations in adult rats. Neuropsychopharmacology,  32(3), 607-15. doi:http://dx.doi.org/10.1038/sj.npp.1301127 Fairman, B. J. (2015).  Contributions to the epidemiology and mental health consequences of cannabis smoking  (Order No. AAI3619011). Available from PsycINFO. (1664224820; 2015-99040-239). Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search-proquest-com.proxyiub.uits.iu.edu/docview/1664224820?accountid=11620 Fergusson, D. M., Boden, J. M., & Horwood, L. J. (2006). Cannabis use and other illicit drug use: Testing the cannabis gateway hypothesis.  Addiction,  101(4), 556-569. doi:http://dx.doi.org/10.1111/j.1360-0443.2005.01322.x Filbey, F. M., McQueeny, T., DeWitt, S. J., & Mishra, V. (2015). Preliminary findings demonstrating latent effects of early adolescent marijuana use onset on cortical architecture. Developmental Cognitive Neuroscience, 16, 16-22. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1016/j.dcn.2015.10.001 Fontes, M. A., Bolla, K. I., Cunha, P. J., Almeida, P. P., Jungerman, F., Laranjeira, R. R., Bressan, R. A., & Lacerda, A. L. T. (2011). Cannabis use before age 15 and subsequent executive functioning.  The British Journal of Psychiatry,  198(6), 442-447. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1192/bjp.bp.110.077479 Gruber, S. A., Dahlgren, M. K., Sagar, K. A., Gà ¶nenà §, A., & Lukas, S. E. (2014). Worth the wait: Effects of age of onset of marijuana use on white matter and impulsivity. Psychopharmacology, 231(8), 1455-1465. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1007/s00213-013-3326-z Hall, W. D., & Lynskey, M. (2005). Is cannabis a gateway drug? testing hypotheses about the relationship between cannabis use and the use of other illicit drugs.Drug and Alcohol Review,  24(1), 39-48. doi:http://dx.doi.org/10.1080/09595230500126698 Hart, H. (2007). Alcohol, drugs, and the adolescent brain.  Developmental Medicine and Child Neurology,  49(12), 883. Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search-proquest-com.proxyiub.uits.iu.edu/docview/195605999?accountid=11620 Hayatbakhsh, M. R., Najman, J. M., Jamrozik, K., Mamun, A. A., Alati, R., & Bor, W. (2007). Cannabis and anxiety and depression in young adults: A large prospective study.  Journal of the American Academy of Child & Adolescent Psychiatry,  46(3), 408-417. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1097/chi.0b013e31802dc54d Henquet, C., Krabbendam, L., Spauwen, J., Kaplan, C., Lieb, R., Wittchen, H., & Van Os, J. (2005). Prospective cohort study of cannabis use, predisposition for psychosis, and psychotic symptoms in young people.  BMJ: British Medical Journal,  330(7481), 11. doi:http://dx.doi.org/10.1136/bmj.38267.664086.63 Hill, M. N., Patel, S., Campolongo, P., Tasker, J. G., Wotjak, C. T., & Bains, J. S. (2010). Functional interactions between stress and the endocannabinoid system: From synaptic signaling to behavioral output.  The Journal of Neuroscience,  30(45), 14980-14986. doi:http://dx.doi.org/10.1523/JNEUROSCI.4283-10.2010 Hunt, G. E., Bergen, J., & Bashir, M. (2002). Medication compliance and comorbid substance abuse in schizophrenia: Impact on community survival 4 years after a relapse.  Schizophrenia Research,  54(3), 253-264. doi:http://dx.doi.org/10.1016/S0920-9964(01)00261-4 Hwang, J. K., & Clarke, H. (2016). Cannabis and pain: A review.  Journal of Pain Management,  9(4), 395-413. Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search.proquest.com/docview/1949290907?accountid=11620 Iversen, L. (2004). How cannabis works in the brain. In D. Castle, & R. Murray (Eds.),  Marijuana and madness: Psychiatry and neurobiology; marijuana and madness: Psychiatry and neurobiology  (pp. 19-40, Chapter xvi, 218 Pages) Cambridge University Press, New York, NY. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1017/CBO9780511543630.004 Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search-proquest-com.proxyiub.uits.iu.edu/docview/620584373?accountid=11620\ Jacobus, J., McQueeny, T., Bava, S., Schweinsburg, B. C., Frank, L. R., Yang, T. T., & Tapert, S. F. (2009). White matter integrity in adolescents with histories of marijuana use and binge drinking.  Neurotoxicology and Teratology,  31(6), 349-355. doi:http://dx.doi.org/10.1016/j.ntt.2009.07.006 Johnston, L. & O’Malley, P.M. (2015). Monitoring the Future: National Survey Results on Drug Use, 1975-2014. Bethesda, MD: National Institute on Drug Abuse, U.S. Dept. of Health and Human Services, National Institutes of Health Ledent, C., Valverde, O., Cossu, G., Petitet, F., Aubert, J. F., Beslot, F., Bohme, G. A., Imperato, A., Pedrazzini, T., Roques, B. P. Vassart, G., Fratta, W., & Parmentier, M. (1999). Unresponsiveness to cannabinoids and reduced addictive effects of opiates in CB1 receptor knockout mice.  Science,  283(5400), 401-404. Lee, T. T. Y., & Gorzalka, B. B. (2015). Evidence for a role of adolescent endocannabinoid signaling in regulating HPA axis stress responsivity and emotional behavior development. In  International review of neurobiology  (Vol. 125, pp. 49-84). Academic Press.   Retrieved from https://www-sciencedirect-com.proxyiub.uits.iu.edu/science/article/pii/S0074774215000987?_rdoc=1&_fmt=high&_origin=gateway&_docanchor=&md5=b8429449ccfc9c30159a5f9aeaa92ffb Levine, A., Clemenza, K., Rynn, M., & Lieberman, J. (2017). Evidence for the risks and consequences of adolescent cannabis exposure.  Journal of the American Academy of Child & Adolescent Psychiatry,  56(3), 214-225. http://dx.doi.org.proxyiub.uits.iu.edu/10.1016/j.jaac.2016.12.014 Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search-proquest-com.proxyiub.uits.iu.edu/docview/1875567972?accountid=11620 Lewis, S. W., Tarrier, N., & Drake, R. J. (2005). Integrating non-drug treatments in early schizophrenia.  The British Journal of Psychiatry,  187, s65-s71. doi:http://dx.doi.org/10.1192/bjp.187.48.s65 Leyton, M. (2016). Legalizing marijuana. Journal of Psychiatry & Neuroscience, 41(2), 75-76. http://dx.doi.org.proxyiub.uits.iu.edu/10.1503/jpn.160012 Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search-proquest-com.proxyiub.uits.iu.edu/docview/1819128922?accountid=11620 Lovelace, J. W., Corches, A., Vieira, P. A., Hiroto, A. S., Mackie, K., & Korzus, E. (2015). An animal model of female adolescent cannabinoid exposure elicits a long-lasting deficit in presynaptic long-term plasticity.  Neuropharmacology,  99, 242-255. doi:http://dx.doi.org/10.1016/j.neuropharm.2015.04.034 Lu, A. T., Ogdie, M. N., Jà ¤rvelin, M., Moilanen, I. K., Loo, S. K., McCracken, J. T., McGough, J. J., Yang, M. H., Peltonen, L., Nelson, S. F., Cantor, R. M., & Smalley, S. L. (2008). Association of the cannabinoid receptor gene (CNR1) with ADHD and post-traumatic stress disorder.  American Journal of Medical Genetics Part B: Neuropsychiatric Genetics,  147b(8), 1488-1494. doi:http://dx.doi.org/10.1002/ajmg.b.30693 Lubman, D., Bonomo, Y., & Yucel, M. (2007).   Drug use in young people; short-term effects and long-term harms. In Gilvarry, E., & McArdle, P. (Eds.).   Alcohol, Drugs, and Young People: Clinical Approaches, Clinics in Developmental Medicine No. 172. London: Mac Keith Press, pp. 18-50.   Meier, M. H., Caspi, A., Ambler, A., Harrington, H., Houts, R., Keefe, R. S. E., MacDonald, K., Ward, A., Poulton, R., & Moffitt, T. E. (2012). Persistent cannabis users show neuropsychological decline from childhood to midlife.  PNAS Proceedings of the National Academy of Sciences of the United States of America,  109(40), E2657-E2664. doi:http://dx.doi.org/10.1073/pnas.1206820109 Moore, T. H. M., Zammit, S., Lingford-Hughes, A., Barnes, T. R. E., Jones, P. B., Burke, M., & Lewis, G. (2007). Cannabis use and risk of psychotic or affective mental heath outcomes: A systematic review.  The Lancet,  370(9584), 319-328. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1016/S0140-6736(07)61162-3 Morales-Muà ±oz, I., Jurado-Barba, R., Ponce, G., Martà ­nez-Gras, I., à ngel Jimà ©nez-Arriero, M., Moratti, S., & Rubio, G. (2014). Characterizing cannabis-induced psychosis: A study with prepulse inhibition of the startle reflex.  Psychiatry Research,  220(1-2), 535-540. doi:http://dx.doi.org/10.1016/j.psychres.2014.08.010 Moreira, F. A., & Lutz, B. (2008). The endocannabinoid system: Emotion, learning and addiction.  Addiction Biology,  13(2), 196-212. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1111/j.1369-1600.2008.00104.x Morral, A. R., McCaffrey, D. F., & Paddock, S. M. (2002). Reassessing the marijuana gateway effect.  Addiction,  97(12), 1493-1504. doi:http://dx.doi.org/10.1046/j.1360-0443.2002.00280.x Patton, G. C., Coffey, C., Carlin, J. B., Degenhardt, L., Lynskey, M., & Hall, W. (2002). Cannabis use and mental health in younger people: Cohort study.  BMJ: British Medical Journal,  325(7374), 1195-1198. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1136/bmj.325.7374.1195 Pickel, V. M., Chan, J., Kash, T. L., Rodriguez, J. J., & MacKie, K. (2004). Compartment-specific localization of cannabinoid 1 (CB1) and ÃŽ ¼-opioid receptors in rat nucleus accumbens.  Neuroscience,  127(1), 101-112. Pope, H. G., Jr., Gruber, A. J., Hudson, J. I., Cohane, G., Heustis, M. A., & Yurgelun-Todd, D. (2003). Early-onset cannabis use and cognitive deficits: What is the nature of the association?  Drug and Alcohol Dependence,  69(3), 303-310. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1016/S0376-8716(02)00334-4 Quinn, H. R., Matsumoto, I., Callaghan, P. D., Long, L. E., Arnold, J. C., Gunasekaran, N., Thompson, M. R., Dawson, B., Mallet, P. E., Kashem, M. A., Mastuda-Matsumoto, H., Iwazaki, T., & McGregor, I. S. (2008). Adolescent rats find repeated Δ⠁ ¹-THC less aversive than adult rats but display greater residual cognitive deficits and changes in hippocampal protein expression following exposure.Neuropsychopharmacology,  33(5), 1113-1126. doi:http://dx.doi.org/10.1038/sj.npp.1301475 RodrÄ ±ÃŒ guez, J. J., Mackie, K., & Pickel, V. M. (2001). Ultrastructural localization of the CB1 cannabinoid receptor in ÃŽ ¼-opioid receptor patches of the rat caudate putamen nucleus.  Journal of Neuroscience,  21(3), 823-833 Romeo, R. D. (2013). The teenage brain: The stress response and the adolescent brain.  Current Directions in Psychological Science,  22(2), 140-145. doi:http://dx.doi.org/10.1177/0963721413475445 Rubino, T., & Parolaro, D. (2014). Cannabis abuse in adolescence and the risk of psychosis: A brief review of the preclinical evidence.  Progress in Neuro-Psychopharmacology & Biological Psychiatry,  52, 41-44. doi:http://dx.doi.org/10.1016/j.pnpbp.2013.07.020 Rubino, T., Realini, N., Guidali, C., Braida, D., Capurro, V., Castiglioni, C., & Parolaro, D. (2008). Chronic Δ 9-tetrahydrocannabinol during adolescence provokes sex-dependent changes in the emotional profile in adult rats: behavioral and biochemical correlates.  Neuropsychopharmacology,  33(11), 2760. Sobesky, M., & Gorgens, K. (2016). Cannabis and adolescents: Exploring the substance misuse treatment provider experience in a climate of legalization. International Journal of Drug Policy, 33, 66-74. http://dx.doi.org.proxyiub.uits.iu.edu/10.1016/j.drugpo.2016.02.008 Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search-proquest-com.proxyiub.uits.iu.edu/docview/1813639780?accountid=11620 Spechler, P. A., Orr, C. A., Chaarani, B., Kan, K., Mackey, S., Morton, A., Snowe, M. P., Hudson, K. E., Althoff, R. R., Higgins, S. T., Cattrell, A., Flor, H., Nees, F., Banaschewski, T., Bokde, A. L. W., Whelan, R., Buchel, C., Bromburg, U., Conrod, P., Frouin, V., Papadopoulous, D., Gallinat, J., Heinz, A., Walter, H., Ittermann, B., Gowland, P., Paus, T., Poustka, L., Martinot, J., Artiges, E., Smolka, M. N., Schumann, G., & Garavan, H. (2015). Cannabis use in early adolescence: Evidence of amygdala hypersensitivity to signals of threat.  Developmental Cognitive Neuroscience,  16, 63-70. doi:http://dx.doi.org/10.1016/j.dcn.2015.08.007 Stefanis, N. C., Delespaul, P., Henquet, C., Bakoula, C., Stefanis, C. N., & Van Os, J. (2004). Early adolescent cannabis exposure and positive and negative dimensions of psychosis.  Addiction,  99(10), 1333-1341. doi:http://dx.doi.org/10.1111/j.1360-0443.2004.00806.x Stuart, E. A., & Green, K. M. (2008). Using full matching to estimate causal effects in nonexperimental studies: Examining the relationship between adolescent marijuana use and adult outcomes.  Developmental Psychology,  44(2), 395-406. doi:http://dx.doi.org/10.1037/0012-1649.44.2.395 Tait, R. J., Mackinnon, A., & Christensen, H. (2011). Cannabis use and cognitive function: 8†year trajectory in a young adult cohort.  Addiction,  106(12), 2195-2203. doi:http://dx.doi.org/10.1111/j.1360-0443.2011.03574.x Tapert, S. F., Granholm, E., Leedy, N. G., & Brown, S. A. (2002). Substance use and withdrawal: Neuropsychological functioning over 8 years in youth.  Journal of the International Neuropsychological Society,  8(7), 873-883. doi:http://dx.doi.org/10.1017/S1355617702870011 Van Gundy, K., & Rebellon, C. J. (2010). A life-course perspective on the gateway hypothesis.  Journal of Health and Social Behavior,  51(3), 244-59. Retrieved from http://proxyiub.uits.iu.edu/login?url=https://search.proquest.com/docview/755695027?accountid=11620 van Laar, M., van Dorsselaer, S., Monshouwer, K., & de Graaf, R. (2007). Does cannabis use predict the first incidence of mood and anxiety disorders in the adult population?  Addiction,  102(8), 1251-1260. doi:http://dx.doi.org.proxyiub.uits.iu.edu/10.1111/j.1360-0443.2007.01875.x Van Os, J., Bak, M., Hanssen, M., Bijl, R. V., De Graaf, R., & Verdoux, H. (2002). Cannabis use and psychosis: a longitudinal population-based study.  American journal of epidemiology,  156(4), 319-327.   doi: https://doi.org/10.1093/aje/kwf043 Wade, D., Harrigan, S., Edwards, J., Burgess, P. M., Whelan, G., & McGorry, P. D. (2006). Course of substance misuse and daily tobacco use in first-episode psychosis.  Schizophrenia Research,  81(2-3), 145-150. doi:http://dx.doi.org/10.1016/j.schres.2005.09.010 Womack, S. R., Shaw, D. S., Weaver, C. M., & Forbes, E. E. (2016). 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Source Of Mechanical Energy Engineering Essay

Source Of Mechanical Energy Engineering Essay Introduction Electricity is a basic part of nature and it is one of our most widely used forms of energy. It is a secondary energy source that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. Many cities and towns were built alongside waterfalls (a primary source of mechanical energy) that turned water wheels to perform work. Electricity consists of the presence of electric charges, as well as the flow of those charges. There are three forms of electricity. One form is static electricity, which is the presence of either positive (+) or negative (à ¢Ã‹â€ Ã¢â‚¬â„¢) electric charges in or on an object, usually a non-conducting material. The second form of electricity is the flow or movement of free electrons through a conducting material, such as a metal wire, toward an area of positive electric charges Electricity appears in two forms: alternating current (AC) and direct current (DC). Direct current does not change directions the electron flow is always from the negative pole to the positive pole although as we mentioned before, the electrons themselves dont really move, its the holes that are created that move. Direct current is almost always what is used inside of electronic devices to power the various internal components, but it is a harmful thing in audio signals, which are alternating current. Alternating current (AC) electricity is the type of electricity commonly used in homes and businesses throughout the world. While direct current (DC) electricity flows in one direction through a wire, AC electricity alternates its direction in a back-and-forth motion. The direction alternates between 50 and 60 times per second, depending on the electrical system of the country. AC electricity is created by an AC electric generator, which determines the frequency. What is special about AC electricity is that the voltage can be readily changed, thus making it more suitable for long-distance transmission than DC electricity. But also, AC can employ capacitors and inductors in electronic circuitry, allowing for a wide range of applications. Direct current or DC electricity is the continuous movement of electrons from an area of negative (à ¢Ã‹â€ Ã¢â‚¬â„¢) charges to an area of positive (+) charges through a conducting material such as a metal wire. Whereas static electricity sparks consist of the sudden movement of electrons from a negative to positive surface, DC electricity is the continuous movement of the electrons through a wire. A DC circuit is necessary to allow the current or steam of electrons to flow. Such a circuit consists of a source of electrical energy (such as a battery) and a conducting wire running from the positive end of the source to the negative terminal. Electrical devices may be included in the circuit. DC electricity in a circuit consists of voltage, current and resistance. The flow of DC electricity is similar to the flow of water through a hose. Electrical Wiring Electrical wiring system is a network of electrical conductors for carrying electrical current to the electrical equipment involved. This method is related to the wiring system for buildings in Malaysia. In Malaysia, the electric wiring system is subject to the rules established by the Energy Commission as provided under the Electricity Supply Act 1990, Electricity Regulations 1994, the MS IEC 60364:2003 Standard Electrical Installations of Building, MS 1936:2006 Electrical Installations of Building Guide To MS IEC 60364 and the MS 1979:2007 Electrical Installation of Building Code of Practice. Wiring systems used in Malaysia is very similar to the electrical wiring standards used by the United Kingdom but by the standards of the wire conductor already changed. NEW TOWN DEVELOPMENT SDN BHD PROJECT The high-rise building electrical system For The New Town Development Sdn Bhd project, this building was a high-rise commercial building. The building comprises of 4 storey basement parking and 7 storey shopping complex and the rest are offices lot. So, for the electrical installation should at every floor there were a number of electrical panels to serve all the lighting and power requirements on that floor including the lighting, switched socket outlets, toilet exhaust fans and anything else. Some areas of the office used an open floor office systems so under floor trunking was also used here. Besides, a few of the panel were located inside the riser room of each floor. However, since each was a large area some panels needed to be located at the office area. Wiring directly from the electrical riser would be unnecessarily too long. Therefore, the electrical consultant locates these electrical panels along the corridors throughout the building. The design architect was requested to provide small rooms to house the panel. Alternatively, small electrical cabinets with lockable doors and sufficient work access and ventilation would be acceptable. If the planned building is very high example like 40 storey office building or in cases where heavy loads are located at higher levels of the building, it may be necessary to provide substations at the higher levels of the building. For the 40-storey office building, an 11/415 kV substation may be necessary at one of the upper floor. It may be located at twentieth floor, for example. All the electrical substation room spaces as explained earlier will then need to be provided except the authoritys electrical rooms. The floors of this substation would then need to be specifically designed by the appointed structural consultants to handle the loads of all the substation equipment. Based on the structures and other factors was related. We propose the installation of electricity for this building using the radial system and ring main system. Because its easier to maintain and simple system for the design and construction. In addition, using the rising main distribution system is important because the building is more than 5 levels. So, to distribute electric power at every level is appropriate to use the rising main for the building. Basement A basement is one or more floors of a building that are either completely or partially below the ground floor. Basements are typically used as a utility space for a building where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system are located; so also are amenities such as the electrical distribution system, and cable television distribution point. In British English the word basement is used for underground floors of, for example, department stores but is used for a space below the ground floor of a house only when it is habitable, with windows and (usually) its own access. The word cellar is used to apply to any such large underground room. Subcellar is a cellar that lies further underneath. Based on the planned building project, the level of 1st to 4th is the basement. In part this is a car park. Therefore, we recommend the installation of electricity in the area using ring system. Ring system is ideal because in this part do not use electrical appliances and many others. Basement car parks.jpg Basement pendlehill1.jpg Basement Ring Main System in Basement A ring main wiring circuit is the alternative to a radial wiring circuit. In a radial wiring circuit, the wiring starts at the circuit breaker and connects to each device on the circuit (fans, outlets, lamps, etc) in turn. When it reaches the last device, the wiring simply ends. Ring main wiring goes one step further instead of ending the wiring at the last device; it pulls more wiring back from the last device to the circuit breaker, completing a loop. Ring main wiring is required in some places, and illegal in others. The main advantage to a ring main system is smaller wiring. Since each device on the ring has two hot wires connecting it to the circuit breaker (one on each side of the loop), smaller wiring can be used to safely carry the electric current. Smaller wire is both cheaper and easier to work with. It bends more easily, can be pulled around corners with less effort, and is easier to fit into the screws and connectors you need to attach it to. One other advantage is wiring distance. Wire has some small amount of resistance, and the longer the wire goes to reach the device it is powering, the more resistance it has. This results in a voltage drop over the length of the wire run (by Ohms Law), which could affect the operation of your electrical devices if it drops too low. The maximum distance from the circuit breaker around the ring is the midpoint of the ring, while the maximum distance in a radial circuit is the end of the chain. In this manner, the ring setup effectively cuts the distance to the farthest device in half. The radial system does have one advantage over ring main. If a break were to occur somewhere in the wiring loop of a ring main system, you wouldnt know it. Everything would still function normally because it is still powered from one end. However, this means that if you took advantage of the ability to run smaller wiring (and everyone does), your wire is now undersized for the current it is expected to handle because the system is no longer powered from two wires, only one. This can result in overheating of the wires, which in turn breaks down the insulation and can start a fire. In electricity supply, a ring final circuit or ring circuit (informally also ring main or just ring) is an electrical wiring technique developed and primarily used in the United Kingdom that provides two independent conductors for live, neutral and protective earth (ground) within a building for each connected load or socket. 557px-Ring_circuit.svg.png ring distribution Ring Main Distribution Size of cable used to ring system is 2.5 mm2. Installation Rules of Ring System at basement Rules for ring circuits say that the cable rating must be no less than two thirds of the rating of the protective device. This means that the risk of sustained overloading of the cable can be considered minimal. In practice, however, it is extremely uncommon to encounter a ring with a protective device other than a 30 A fuse, 30 A breaker, or 32 A breaker, and a cable size other than those mentioned above. The IEE Wiring Regulations (BS 7671) permit an unlimited number of socket outlets to be installed on a ring circuit, provided that the floor area served does not exceed 100 m2. In practice, most small and medium houses have one ring circuit per storey, but for this building should having more. An installation designer may determine by experience and calculation whether additional circuits are required for areas of high demand; for example, it is common practice to put kitchens on their own ring circuit or sometimes a ring circuit shared with a utility room to avoid putting a heavy load at one point on the main downstairs ring circuit. A heavy concentration of load close together on a ring circuit can cause minor overloading of one of the cables if near the end of the ring, so kitchens should not be wired at one end of a ring circuit. Unfused spurs from a ring wired in the same cable as the ring are allowed to run one single or double socket (the use of two singles was previously allowed but was banned because of people replacing them with doubles) or one fused connection unit (FCU). Spurs may either start from a socket or be joined to the ring cable with a junction box or other approved method of joining cables. Triple and larger sockets are generally fused and therefore can also be placed on a spur. It is not permitted to have more spurs than sockets on the ring, and it is considered bad practice by most electricians to have spurs in a new installation (some think they are bad practice in all cases).Where loads other than BS 1363 sockets are connected to a ring circuit or it is desired to place more than one socket for low power equipment on a spur, a BS 1363 fused connection unit (FCU) is used. In the case of fixed appliances this will be a switched fused connection unit (SFCU) to provide a point of isolation for the appliance, but in other cases such as feeding multiple lighting points (putting lighting on a ring through is generally considered bad practice in new installation but is often done when adding lights to an existing property) or multiple sockets, an unswitched one is often preferable. Shopping Complex Based on commercial building a project was planned by the New Town Development Sdn Bhd. A 40 storey high building will put the shopping complex of seven stories are starting at level 5th to 11th. Thus, the electrical installation for this we propose to use a radial system. We feel the radial system is suitable for shopping complex. Because there are a lot of use of electrical appliances such as lights, air conditioners and so on. In addition, the radial system is easy to designed, built and maintained. Shopping Complex at level 5th Shopping Complex at level 5th 8th Offices In this building project, a total of 29 levels will be provided for offices start from level 12th to 40th. Based on this, we agreed to use the same method of electrical installations such as shopping complexes, namely the radial system. This method is ideal because it is easy to maintain. In addition, if there is damage to the wire. It is easily known and easily repaired than the ring system. Office Radial System in Shopping Complex and Offices The radial system is widely used, economical systems often found in low-load density areas. To reduce the duration of interruption, overhead feeders can be protected by automatic reclosing devices located at the substation or at various locations on the feeder. This device reenergizes the feeder if the fault is temporary. To further reduce the duration and extent of customer interruptions, sectionalizing fuses are installed on branches of radial feeders allowing unaffected portions of a feeder to remain in service. Radial distribution systems are the simplest systems to plan, construct, and maintain, but are also the least reliable because of the radial nature of the design being served from a single source at a time. If any part of the system experiences a failure, some or all of the customers served by the radial feeder will be without power until a repair is completed. Straightforward design, lower cost, and decent reliability are the distinguishing characteristics of the RDS. An auto-loop distribution system is a special type of radial distribution system and is differentiated by having two feeders that tie to a customer load. The auto-loop system automatically senses the loss of one source of voltage and quickly and automatically switches the load to the second feeder. This type of system adds reliability benefits by keeping outages to a few seconds (or less) but the added cost of having two sets of utility equipment at one location, could be as high as hundreds of thousands of dollars for each installation. radial distribution Radial System Radial system distribution Size of cable commonly used for circuit radius is 4 mm2 Rising Main Distribution for commercial building For multi-storey buildings such as this are ideal to use the rising system. This is because, to ensure that each level of the building is fully supplied with electricity from renewable sources of electricity. A riser is a feeding cable or pipe giving supply to upper floors of a multi-storey building (high rise building). The above picture shows a typical installation of bus duct rising mains in the riser room at individual floor of a high rise building (The Bus duct was taken in the riser room at one of the upper floors of a high rise building). Most of the major components of a bus duct riser system. In electrical works, a riser is a set of cables the supply the upper floors. The feeding cables rise up straight to the top floor. Then at each floor a tap-off unit is connected so electricity can be supplied to that floor (for this project, we propose the radial distribution system). An alternative is to run one individual set of cables to each floor. Then there would be many cables that need to be installed the number of which is directly proportional to the number of upper floors. There are actually three risers, first one is the normal main electricity supply. This supply is just the normal authority supply like the one you have in your house. The 100A tap off unit is for this riser. The second tap off, which is one of the 60A units, is what is called essential supply, or emergency supply. It is a normal authority supply like the one you have from the 100A tap off unit above. However, it is also backed by a standby diesel generator. This means that if the electricity supply from the authority distribution network fails due to problem with their underground distribution cables or whatever, the standby electric generator would kick in and switch in the locally generated electricity to this electrical riser. Large capacity electric generators are expensive. Therefore, it is not economical to supply all electricity needs in the building from this generator. That is why separate electrical risers are used, and the normal riser is not backed by the generator supply. The third tap off unit (the second 60A unit) is for the air conditioning system. It is quite common (and is considered a better design) to have a separate feeder cable for the air conditioning and mechanical ventilation (ACMV) system in a large building. That is the reason for the third electrical riser here. rising main detail Rising Main Distribution Rising main distribution is use to distribute 415v 3-phase electricity from main distribution board to all floors. The copper vertical bus bars which run up in electricity cable riser. The vertical duct or trunking to the height of the building. To prevent the spread of fire and smoke, fire barriers are incorporated with the bus bar chamber at each compartment floor level. One more point to note here is that some office buildings use the generator-backed supply example like essential supply to feed the electrical riser for the air-conditioning system. With this arrangement, ACMV equipment that need to continue operating even during the mains failure do not need to be connected to ESSENTIAL supply riser, which is why it is given a separate riser in the first place. Observe the large flexible conduits coming out from the bottom of the tap off units and connect to the orange-colored electrical trunking. Some installations use rigid metal trunking for this purpose. Cables are run from a tap off unit into the flexible conduit to go to the orange metal trunking. They run inside the trunking to connect to the respective sub-switchboard. The switchboard for the air conditioning system is normally located inside the AHU room of that particular floor. From the sub-switchboards, separate outgoing cables are run inside the trunking to connect to separate distribution boards (DB) on that particular floor. Even though electrical installations at hospitals are relatively much more complex than the office building above, the installation at their hostel and staff quarters buildings are usually very simple. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhV61rUq88O0Xy7YTrelt2yowwifONeIa-ZW7yh19vQmkPeu3J-1Y7hHgQtz307XF0UkqiXu_SSFa4Fb_V1HKNccdwSnobstKbpmjUQKaXqszVRJwDFYalpR8If4H4S2kZh4ElmdZqr2HQE/s320/Floor+Sub-switchboard+Picture.JPG Typical bus duct rising main at individual building floors https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizG7RI6nSwjAbnDarQy28B7pIIM3MKyIIlrS7DlRYlt9598Kb1XOmHb93MTPxkxwba1kJw0NHVhvemp8MPknrxpJN8Ss5cZ5_nVCUQuhDJy0KyW3RP7JkCJEPVxRpi4M6gGJ4dM8Qjy3Mk/s320/Electrical+Busduct+Riser+Picture.jpg The electrical riser room Basically, there only two new components at each riser, which is the Termination Box (Feed In Box) and the incoming cables that terminate into the termination box. The generator-backed Essential supply cables need to have red colored insulation. It is because this supply is part of the fire emergency system of the building. A fire-rated cable must be able to continue operating for a certain number of hours during fire before it fails. This is the requirement. It used to be MICC (mineral insulated copper cables) cables that play this role, but now people use mostly the fire-rated cables for this purpose except in very special installation condition. The fire-rated cables are cheaper, easy to install and maintain. The black-colored cables are from the Normal supply. That means the other ends of the cables are connected to the Normal Supply main switchboard. While the red cables are connected to the Essential Supply main switchboard. Which means the Essential Supply main switchboard is the one that is backed by the standby electric generator. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnUVFo4Ow5O_5aw9gXLgkgEPRhwKKH0zb_7mRsVKQ2WdZ7o6yZUfoZjc8QqHUraNIOSak96q4urdP0h8mH7uAvvLc226vQ2GV_N6oGmzVvVD9V-Pb-2sK-JxSVlojWplOwYVN2S-WDhWQQ/s320/Busbar+Trunking+Picture.jpg The bus duct risers at riser room https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwUQiCxmY8rNhbDnm4jSfrAXbOuXJrBgZ3qxqRfnwqq6FLylNA7y0oO0oA3HijKJC1mYE1oI7aG4Q0z2djGi7YksNw_nNX4rx5ReexorHCt-Y3yFz1sVxPo69xpZurPA4o8QK4dmgYQBv0/s320/60+A+TPN+Tap+Off+Unit+Image.jpg The front view of one of the 60A TPN tap off units https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjniMJNRxBQAejfUrfX5ges2TGPfDQy3duDxKBWnV2v_ewIhLlt5VBmciGy4s7mYmhujg6YbCSeBQPY5TobwTQ8mM-Yc8SVw-RrbvMrQXMKf2cMj1jIHUD_t7NI2TPMYnHWsqNwPFYwcNbU/s320/Busduct+Conductors+Arrangement+Image.JPG A closer view of the vertical bus duct showing the arrangement of the conductors inside Cables and busways A busbar trunking system comprises a set of conductors protected by an enclosure. Used for the transmission and distribution of electrical power, busbar trunking systems have all the necessary features for fitting: connectors, straights, angles, fixings, etc. The tap-off points placed at regular intervals make power available at every point in the installation. A busbar trunking is placed at the offices. http://www.electrical-installation.org/w/images/c/c9/FigE37.jpg Busbar trunking system design for distribution of currents from 25 to 4000A. The various types of busbar trunking Busbar trunking systems are present at every level in electrical distribution: from the link between the transformer and the low voltage switch switchboard (MLVS) to the distribution of power sockets and lighting to offices, or power distribution to workshops. http://www.electrical-installation.org/w/images/3/32/FigE38.jpg Radial distribution using busways at the offices There are essentially three categories of busways that we proposed for the commercial building, that is; 1) Transformer to MLVS busbar trunking Installation of the busway may be considered as permanent and will most likely never be modified. There are no tap-off points. Frequently used for short runs, it is almost always used for ratings above 1,600 /2,000 A, i.e. when the use of parallel cables makes installation impossible. Busways are also used between the MLVS and downstream distribution switchboards. The characteristics of main-distribution busways authorize operational currents from1,000 to 5,000 A and short-circuit withstands up to 150 kA. 2) Sub-distribution busbar trunking with low or high tap-off densities Downstream of main-distribution busbar trunking, two types of applications must be supplied: Mid-sized premises (industrial workshops with injection presses and metalwork machines or large supermarkets with heavy loads). The short-circuit and current levels can be fairly high (respectively 20 to 70 kA and 100 to 1,000 A). Small sites (workshops with machine-tools, textile factories with small machines,supermarkets with small loads). The short-circuit and current levels are lower (respectively 10 to 40 kA and 40 to 400 A). Sub-distribution using busbar trunking meets user needs in terms of: Modifications and upgrades given the high number of tap-off points Dependability and continuity of service because tap-off units can be connected under energized conditions in complete safety The sub-distribution concept is also valid for vertical distribution in the form of 100 to 5,000 A risers in tall buildings. 3) Lighting distribution busbar trunking Lighting circuits can be distributed using two types of busbar trunking according to whether the lighting fixtures are suspended from the busbar trunking or not. Busbar trunking designed for the suspension of lighting fixtures These busways supply and support light fixtures (industrial reflectors, discharge lamps, etc.). They are used in supermarkets, department stores and warehouses. The busbar trunkings are very rigid and are designed for one or two 25 A or 40 A circuits. They have tap-off outlets every 0.5 to 1 m. Busbar trunking not designed for the suspension of lighting fixtures Similar to prefabricated cable systems, these busways are used to supply all types of lighting fixtures secured to the building structure. They are used in commercial buildings (offices, shops, restaurants and etc.), especially in false ceilings. The busbar trunking is flexible and designed for one 20 A circuit. It has tap-off outlets every 1.2 m to 3 m. Busbar trunking systems are suited to the requirements of a large number of buildings. Industrial buildings: garages, workshops, farm buildings, logistic centers, etc. Commercial areas: stores, shopping malls, supermarkets, hotels, etc. Tertiary buildings: offices, schools, hospitals, sports rooms, cruise liners, etc. Examples of Canalis busbar trunking systems http://www.electrical-installation.org/w/images/3/39/FigE40.jpg Flexible busbar trunking not capable of supporting light fittings  : Canalis KDP (20 A) http://www.electrical-installation.org/w/images/5/5c/FigE41.jpg Rigid busbar trunking able to support light fittings  : Canalis KBA or KBB (25 and 40 A) http://www.electrical-installation.org/w/images/b/b3/FigE42.jpg Lighting duct  : Canalis KBX (25 A) http://www.electrical-installation.org/w/images/a/a5/FigE43.jpg A busway for medium power distribution: Canalis KN (40 up to 160 A) http://www.electrical-installation.org/w/images/5/52/FigE44.jpg A busway for medium power distribution: Canalis KS (100 up to 1000A) http://www.electrical-installation.org/w/images/4/47/FigE45.jpg A busway for high power distribution: Canalis KT (800 up to 1000 A) Trunking and Conduit System in Commercial Building https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKLD2-uA977MoW5B_zHS25IsH-N1qgHyMBIub0NZmhJdVb8Rj6BoYrFqsUMgxduSTY2dCDFZFs8lxTSb-I72B_rfCdE2aquR6oDmgPnAafPlblmE5qscQQAhR6pl1zANROQZX-b_4MOGy4/s320/Mechanical+and+Electrical+Coordination+Picture.jpg Conduit and trunking This picture shows how the electrical conduit and trunking installation should be coordinated with water pipes on the building. Trade subcontractors (water piping sub-contractors, electrical sub-contractors, telephone cabling contractor, computer network contractor and others) must not be allowed to proceed with the installation of their individual services and equipment on the first come, first served basis. Prior to the commencement of the installation works by trade sub-contractors, a set of proper coordinated drawings, endorsed by all relevant parties, should be made available to all the sub-contractors involved in a particular area. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6nbXcG7Zbu1rKby958MAYEc8EXN0jzomHz9trvAGeuzB_oyybn_egiE_Jf4v4xwgTy6J7vmQ9Ehul2Ya3p1jziXGKnEq1QlL9oQggHTqYcGnj0UgNjt7pWA6TLwqNWlpNsJRFF4tAZlPS/s320/Below+Slab+Trunking+Installation+Photo.jpg Electric trunking running below soffit of a concrete floor slab There is no electrical installation work of a significant size can be done properly without the use of an electric trunking. A trunking is a larger size of a conduit. When you need to run a number of electric conduits along each other for a significant distance, then consider using a trunking in place of the conduits. There are so many sizes you can choose from. The above picture is an example of a trunking installation above ceiling level, under the soffit of the concrete floor slab. we also labeled some of the other services there for the benefit of those non-electrical readers who need pictures like this for reference, to know what is what among the myriads of pipes, conduits and trunking running above the ceiling level. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVEfmIApkNj19S2b4vhZi-1isA8nTIh7M0L672RPrrkv_tehHT5HtY7TT2nhJB5zmVjJROyleelMPQGidxSL7L31FzZ-mydEVv6A_wVBIfeWr2-APz5ILNi584yZ5BTEYEr56DmSMMS3Ul/s320/Wiring+Trunking+Picture.jpg Electrical trunking in and out of the electric panels There are electrical trunking connecting the panels at above and below the panels. But the box-up walls have hid them. This picture is metal trunking. In future, the maintenance electrician would need to access and open the cover of the trunking in the repair and upgrading works. Therefore, a means of access is required, which was not provided at all at the mock-up unit. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvdpm9DlN8YOf9fR8WW8C0ynAf_vq6cuQKom7LtZUiWHC9fPXx7Eq-93jbs5E6kz1sXpBv_6pqu9VMYkLo_E61WPwaLlh8wQIHD_tJRAvJbKpoJ4NZGlSCMVmel4LpJ0Iq3A0PLJFcJ9p_/s320/Underfloor+Trunking+Installation+Photo.jpg Under floor trunking installation The under floor trunking system has been around for a long time. An under floor trunking system is an alternative way of providing the dedicated routes to run electrical cables, telephone cables or any other wiring cables. An 11KV cable is not a wiring cable. A 25 sq.mm electrical feeder cable to supply an 11 KW fire pump panel is not a wiring cable. The 1.5 sq.mm cables that are used for wiring the office lights are categorized wiring cables. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK3nUI41uH4Ci_zKiqpeCZ5qYLnvUTJwTSJQQVbaSizaihQ1Km2ksk4HQMZBeXPDt3fbERK-xyeKjfPK4GUmVBEd3qvZFIP2OFP3WaFJDiUe5AloWC8QDrSNDpO2PXO8bUhmx798b_Ia5U/s320/Surface+Conduit+Installation+Picture.jpg Surface conduits The conduits are used to protect the wiring cables that carry the electrical current. Electricity is dangerous. Even though the electric conductors that carry the current is insulated by some PVC covering materials or whatever, the covering material is not strong enough to protect the cable from damage. When the covering is damaged, the electrical conductor inside may be exposed to touch or it can also unintentionally come into contact with things that can carry electric current. This scenario would present a high risk of electric shocks. Therefore, we protect the electric cables so that they do not present the dangers of electric shocks to people (or animals). A second reason to protect the cables is to make sure the electrical system stays reliable. When the cable PVC covering is damaged, the conducting metal can come into contact with other metals that are in contact with earth. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhubiLUOe8e3qfmVf0qDSTIgXjb9hl7ezv8IEdUskD9yXAMsS8Y9Q-UdpKnYR3IQmzZ5M0L4n-EQowlOT7RS1gchILr6IPMnWycucoTGqTqqReSrEBj0GI8VUfXIjD8J4y1bVffshY2dMy7/s320/Overhead+Projector+Installation+Picture.jpg A motorized overhead projector The electrical contractor produced a mock-up unit of the installation bracket for motorized overhead projector. The overhead projector was for meeting rooms (offices level). There were about thirty units to be installed through the building. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFL_Z9UTla9-kS2WbovqO2CpSOroEJU0-D6EFgGmf-fyRvMUIVmZk32c2sIByD3S008sbthjpkgxHz_7Lu5TBmu5DbzwRDyo57VkZbSp0x1T1yiYE5jurDzzrRAKkbQU5AWo33U6wsbr94/s320/Feeder+pillar+picture.jpg Compound lighting feeder pillar A building construction of significant size is usually not complete without at least one small outdoor weatherproof feeder pillar. High rise building electric closets https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6-86IaAb_GZlWICcVlLj3U_q5rczENIjs2ZdWy2doCZPr-8SalcetkNiZIHBDFtyuy2sK92080olOja9BN49XL0axUs088djMUY6W_Lluqmwzx3zZpUcBs-bXSRMOW3JSzUkxvyQCdEAW/s320/Electric+Closet+Picture.jpg Electric closet The electric closet in the following pictures has been done for a multi storey bui