The Methods of Selection in the Recruitment Process Assignment

The Methods of Selection in the Recruitment Process - Assignment Example If the organization does not come to terms with these methods of selection, it hires other companies which search for the required talent. However, what is needed here is an understanding that shall reach upon the premise of hiring people who are skilled enough to deliver the goods as and when required. Recruitment process is important to understand within an organization because it is the basis of resource provision that employers look forward to having (Bierman, 2002). The recruitment process paves the way for the growth and development domains of an organization since it finds the ways and means through which success will be deciphered in a proper way. What is even more significant is the way under which the human resources management department deals with the process of recruitment that shall only make the entire process understandable to the publics who are outside the domains of the organization (Noe, 2009). These publics would want to know what kind of recruitment strategies a re in place within the organization and where the hiring regimes are coming into full action. Since these publics have a fair amount of say within the working methodologies, it is only natural to think of the discussion of stakeholders because these stakeholders have one or the other stake within the organization. Either the shares are being looked after by these stakeholders or they have invested a fair bit under the aegis of the organization (Laser, 1994). The need is to realize where the stakeholders deem the company in a positive way and what kind of optimism they have in mind regarding the chosen organization. In the same light, the organizational discourse must find a way through which the recruitment processes are handled in an ethical and moral way. If the hiring and firing domains are settled properly by the selection methodologies which are in place, then this should mean that the organization is doing something right for the new hires. This would be translated in the form of people joining its fore and aspiring to become a part of it in the coming times as well (Mckinney, 1991). However, many organizations are not well equipped to tackle all these issues and end up being at the receiving end of the public wrath for a number of reasons. The recruitment processes within China and the United Kingdom are important to understand because it outlines the basis of properly utilizing the resources within the domains of an organization. If the recruitment process manifests time delays and similar issues, then it would mean that there are serious problems that exist within the fore of hiring individuals within an organizational setting. Therefore the role of the human resources management department

Greek and Roman art Essay Example | Topics and Well Written Essays - 1750 words

Greek and Roman art - Essay Example The Greek Architecture is roughly divided into the Archaic Age, Classical age and the Hellenistic age. The period starting from 800-500 BC is known as the Archaic age (Pedly, 2007).. Structured temples with a rectangular shape centre and portico in the front started to appear in the Archaic Age. Excavations dating earlier to this age were found in Heroon at Lefkandi a village in Euboea Island (Catling et al., 1991). This structure was referred to as â€Å"Heroon† meaning the â€Å"Heroes Grave†. The mound is nearly 13.8 meters wide. The excavation here dated back to 950 BC. A cemetery like structure with the remains of a man’s ash and a women’s body were found here in 1960 (Lemos, 2009). The Lefkandi excavations are considered quite significant in the history of Greek Architecture because they provide ample insight into the late bronze and early ion age civilizations like Xeropolis (Lemos, 2009). Excavations carried out in Lefkandi in 2003 bought up severa l cemeteries in the area similar to the Heroon of Lefkandi. The structures of these cemeteries are the base of later Greek temples built in the Archaic age. There is a wooden veranda similar to the later days Greek temples Portico. The ashes of the man were stored in a bronze amphora with carvings depicting hunting scenes (Catling et al., 1991). ... The area surrounding Lefkandi is widely known as Old Eretria. These people who settled here should have live here from the early Bronze Age till the beginning of the Archaic period (Catling et al., 1991). They might have moved away from the area because of the Lelantine War. Another notable cemetery found close to the Heroon of Lefkandi is the cemetery for Toumba1. The building should have been erected around tenth century BC. The burial mound has a main entrance on the eastern side, three rooms and a wide corridor. Rows of wooden columns supported the roof and the building ends with an apsidal on the west (Catling et al, 1991). There is a row of post-holes on the walls facing north and south. There is a huge wooden veranda known as peristrasis. This veranda and the post-holes are found in early Greek temples constructed during the Archaic age too (Lemos, 2009). The people buried here are considered to be quite rich as several costly offerings starting from pots to jewellery were exc avated along with the bodies. They should have been offered to the dead as a token of love and gratitude (Lemos, 2009). The Heroon at Lefkandi is considered as a prominent archaeological discovery due to various reasons. The Archaic period is often considered as the beginning of Greek architecture and civilization. But, the Lefkandi excavations proved civilizations and occupations dating back to two hundred years or before prevailed in the area. These excavations were the substantial proof for the culture of Late Helladic IIIC2 period which prevailed around 1075 BCE (Evley, 2006). Many more cemeteries constructed exactly in the style of later day Greek temples like Skoubris and Palia Perivolia was found in the area (Catling et al., 1991). The

Economics for Managers Japan Case Essay Example | Topics and Well Written Essays - 2750 words

Economics for Managers Japan Case - Essay Example For almost a decade, the Japanese have started to adopt a risk-averse mindset after the fall of the dotcoms. Due to the circumstances, zero-return in cash has become the mindset of the people. While prices continue to drop, people further delay their consumption for the hope of lower prices. This hoarding of cash or investing in zero-return or non-interest-bearing savings leads to stagnation and later, worsening deflation in the economy. Thus the country wishes for some inflation to happen by increasing aggregate demand either through an increase in consumer spending, or channeling of money to some real investments in order to stimulate growth in the economy. Because of inflation, the relatively low or zero-return of investments most Japanese consumers have produces a negative interest rate. The Japanese Central Bank now hopes that consumers will then shift their investments to interest-bearing or higher-yielding investments to offset the effect of inflation, such as shares and real estate in order to give a boost to the economy. The cost-push inflation in the economy thus requires the Japanese Central Bank to use some monetary policy to curb it. However, Japanese Central Bank cannot just increase the interest rate in the meantime. While the global economy seems to pose a threat, increasing the interest rate will hurt the economy and worsen the impact of this threat if it happens. Thus, the Japanese Central Bank will keep the interest rates low in order to lessen the impact of the economic crisis abroad to the Japanese economy. The aggregate prices or the overall inflation within an economy is set by the interaction of the aggregate demand and aggregate supply. On one hand, aggregate demand is determined by the total amount  of consumption, investment, government spending and net exports in an economy.

I think that pornography is harmful to a couples relationship Essay

I think that pornography is harmful to a couples relationship - Essay Example In today’s world of technology where everything has gone cyber, all multimedia including pornography is available on the internet easily accessible around the world and has become part and parcel of people’s sexual lives especially youngsters. I would strongly recommend all couples to accept this notion to be a healthy part of their relationships and, in case of any difference of opinions, to discuss openly about this agenda and give it a try to experience the fruitful outcome it generates between them. Through ages, surveys have been conducted to determine whether pornography is harmful for a relationship and what effects it produces for a couple. Consequently, researchers have identified few established facts about the aftereffects of watching pornography by a couple, individually or together. If we see in terms of collectively watching it, we come across two major advantages it provides as explained in a lecture by Mr. Chen: It contributes to the learning and sexual knowledge of couple. They can educate by identifying new exciting activities and ways to physically mate with one’s partner. They can know new ways to stimulate the partner and about the dos and don’ts during sex. It also adds to their chemistry by enhancing the intimacy and ecstasy between them in bed. Couples tend to get bored soon due to repetition of similar activities in every session. Pornography makes them look forward to their regular intercourse sessions where they can try new things as seen on video, creating better thrill and variations (Chen, 14 March 2013). Variety in sexual relationship plays a vital part for almost all couples. According to Crooks and Baur, many individuals have a misconception that excitement and arousals stirred in their sexual experiences will always stay the same as in initial stage. Soon, they seek alternatives as their saving grace to gain satisfaction which they cannot get anymore from their own relationship (Crooks and Baur, pp. 201). This destroys a relationship completely and might ultimately result in breakup out of need for change! This is where the essential role of pornography sweeps in, creating new vibes of pleasures and sensuality. It is important for couple to allow its involvement in their sexual lives and discuss about it when the need arises. Speaking on an individual level, it is also necessary to have personal space to watch pornography occasionally when he or she feels too overdosed with intercourse. Also, according to an article provided in Elia’s book, researches showed that individuals, especially men, claim that, inspired from tactics used in pornographic content, they discovered new methods to pleasure themselves and guide their partners to do the same during sex to stimulate them better. The craving to improvise and to try something different got fulfilled for most of the men by indulging themselves in self-pleasure while watching pornography (Elia, John and Albert, pp. 283). Se xual pleasures are the primary goal for any intimate activity carried out by a couple. In his book, â€Å"Sex Industry: Porn and Prostitution† (Pp. 269-273), suggests that self-pleasures while watching pornography motivates individuals to try these activities with their partners as well. They associate having intercourse with their partners to the reward of getting arousals and ultimately orgasm. There is a possibility of enhancement of emotional attachments in a couple through attaining orgasms which in turn are guided through education learnt via pornography. Therefore, it might prove to be beneficial to discover oneself through self-pleasure exercises during pornography and

Educator interview Essay Example | Topics and Well Written Essays - 750 words

Educator interview - Essay Example There are a number of qualifications that nurses, doctors or any health care professional must meet in order to become an 'educator'. The main qualification, of course, is to have obtained the education necessary to educate others. Formal schooling, training, practice and instruction are all key components to obtaining that education. "The current emphasis on providing quality undergraduate and postgraduate medical education has focused attention on the educational responsibilities of all doctors. There is a greater awareness of the need to train doctors as educators and courses have been set up to satisfy this need" (Hesketh 2001, pg 556). Other training that this individual must go through is how to develop curriculum and effective lesson planning. It is important that they also develop the skills to communicate with students as well as appraising and assessing a student's progress. These skills can be obtained by attending courses focused on the training of teachers. Health care professionals can also be teachers who work with individuals already employed in the health care industry. Such roles may include providing education for staff development and continuing education. ... The teaching individual must keep current on the latest technology and training available in the field in order to communicate that to colleagues. Another method for obtaining the information to be taught is by participating in the industry, as a nurse, as a doctor or professional or even as a researcher. "Nurses are increasingly involved in clinical trials. Any nurse involved in clinical trials may perform one or more of the following roles; patient educator, patient ally, direct care giver, coordinator of care and research administrator of research resources and participant in the conduct of the study" (Ambaum 1997, pg. 5316). These increasing responsibilities for nurses also opens up a whole new world of opportunities for these individuals. Now, they can not only be educators in the 'normal' sense of the world, but in other situations as well. In order for these professionals to do so, they must have the support that any teaching professional would need to accomplish their objective. "A medical educator has needs that are specific to educators and needs that are common to all medical faculty members. And educator needs time to perform educational duties, space to carry out educational activities, and money to buy time, space and other resources." " Just as important as time, space, and money are to the success of an educator is having an infrastructure that supports the educator and the educational mission" (Collins 2005, pp 914-915).According to Collins, creating such an infrastructure would include building a system that could provide educational leadership opportunities, funding for medical educational research, students, student and peer feedback and faculty development and mentoring. It would also

Nutrition - Obesity Essay Example for Free

Nutrition Obesity Essay Objective: To assess the association between the consumption of fast food (FF) and body mass index (BMI) of teenagers in a large UK birth cohort. Methods: A structural equation modelling (SEM) approach was chosen to allow direct statistical testing of a theoretical model. SEM is a combination of confirmatory factor and path analysis, which allows for the inclusion of latent (unmeasured) variables. This approach was used to build two models: the effect of FF outlet visits and food choices and the effect of FF exposure on consumption and BMI. Results: A total of 3620 participants had data for height and weight from the age 13 clinic and the frequency of FF outlet visits, and so were included in these analyses. This SEM model of food choices showed that increased frequency of eating at FF outlets is positively associated with higher consumption of unhealthy foods (b ? 0. 29, Po0. 001) and negatively associated with the consumption of healthy foods (b ? A1. 02, Po0. 001). The SEM model of FF exposure and BMI showed that higher exposure to FF increases the frequency of visits to FF outlets (b ? 0. 61, Po0.001), which is associated with higher body mass index standard deviation score (BMISDS; b ? 0. 08, Po0. 001). Deprivation was the largest contributing variable to the exposure (b ? 9. 2, Po0. 001). Conclusions: The teenagers who ate at FF restaurants consumed more unhealthy foods and were more likely to have higher BMISDS than those teenagers who did not eat frequently at FF restaurants. Teenagers who were exposed to more takeaway foods at home ate more frequently at FF restaurants and eating at FF restaurants was also associated with lower intakes of vegetables and raw fruit in this cohort. International Journal of Obesity (2011) 35, 1325–1330; doi:10. 1038/ijo. 2011. 120; published online 28 June 2011 Keywords: fast food; overweight; ALSPAC Introduction Childhood obesity prevalence have risen dramatically in the last 30 years in the Western world with the most recent figures for England and Wales show that 17% of boys and 16% of girls are obese. 1 An increase in the availability of calorie dense foods is implicated as one of the factors in the aetiology of the obesity epidemic. Fast food (FF) is one section of the food market that has grown steadily over the last few decades and it was worth d8. 9 billion in the United Kingdom in 2005. 2 FF is typically quick, convenient, cheap and Correspondence: Dr LK Fraser, School of Geography, University of Leeds, University road, Leeds LS2 9JT, UK. E-mail: l. k. [emailprotected] ac. uk Received 6 February 2011; revised 21 April 2011; accepted 12 May 2011; published online 28 June 2011 uniform in its production,3 but FF is often high in saturated fats, energy dense and has low micronutrient content. 4–9 Studies from the United States of America have shown that children who consume FF (when compared with children who do not eat FF) have higher energy intake and higher fat intakes9,10 as well as lower vegetable and milk intake. 10,11 Therefore, the consumption of such foods could possibly result in a positive energy balance; and hence, weight gain. There is some evidence from longitudinal studies in the United States of America that consuming FF as a teenager can result in weight gain in both early12 and middle adulthood. 13 FF is often marketed to children and adolescents through television, internet and movie advertising,14–17 with brand recognition being present from an early age. 18 The addition of toys as gifts with FF meals also attracts children. There is growing body of literature that has assessed the location of FF outlets and has found that areas of higher deprivation Fast food and body mass index LK Fraser et al 1326 have more FF outlets19–21 and that FF outlets are often located close to schools. 22–24 The majority of research to date has been undertaken in the United States of America, but a study that analysed the fat content of a FF meal in McDonald’s and Kentucky Fried Chicken outlets in 35 countries showed that the amount of fat varied considerably between countries, within the same FF outlet. 25 This means that results from studies in the United States of America may not be generalisable to other countries. This study aims to assess the cross-sectional association between the consumption of FF and the body mass index (BMI) of teenagers in a large UK birth cohort. Methods The data for this study were obtained from the Avon Longitudinal Study of Parents and Children (ALSPAC),26 which is a birth cohort study where pregnant mothers who lived in the old Avon County in the United Kingdom (the Bristol region) were recruited in the early 1990s. A total of 14 541 mothers completed recruitment. Because of retrospective recruitment the total sample size was 15 224 fetuses and 14 610 live births. This paper presents data on the teenagers who attended the year 13 clinic and completed the year 13 questionnaire. Variables The food frequency data were collected from the questionnaires completed by mother (or carer) and separate questionnaires completed by the teenagers themselves at age 13 years. The data used from the carer questionnaire (collected at the same time point) referred to the questions ‘How often does s/he eat in a FF restaurant? The responses to this question were collected as never/rarely, once a month, once every 2 weeks, once or twice per week, 3–4 times a week, 5 or more times a week. The carers were also asked ‘In total, how many portions of vegetables does s/he eat in a week (do not include potatoes)’, ‘In total, how many portions of raw fruit does s/he eat in a week? ’ These were free numerical responses, which were retained as a continuous variable for analyses. In the food frequency part of the teenager completed questionnaire the teenagers were asked ‘If you ever buy food yourself from outside school, or from school vending machines, how often do you buy and eat each of the following things (include after school and weekends): chips, burger, pizza, sandwich, pies or pasties, chocolate, crisps, fruit and other food. ’ The height and weight data were collected at clinic visits at B13 years. The exact age, sex, height and weight were used to calculate a BMI standard deviation score (BMISDS) for each participant (1990 UK reference dataset). 27 The teenagers International Journal of Obesity were classified as obese if their BMISDS was greater than the 95th percentile (BMISDS41. 64). The physical activity data were collected via accelerometry at the age 13 clinic visit. 28 The participants wore an accelerometer for seven consecutive days and the measure used from this is mean counts per minute, which is a continuous variable. A deprivation score was assigned to each participant by matching the coordinates of their residential address (when carer questionnaire was completed) to the appropriate lower super output area. Each lower super output area has an index of multiple deprivation score (Index of Multiple Deprivation 2007 (IMD))29 assigned from the local census data. This is a continuous variable in which a higher number indicates an area of higher deprivation. Ethnicity was assigned as per the child’s ethnicity into a binary variable of ‘white British’ and ‘other’ ethnicity. Statistical modelling Descriptive statistics were performed in STATA version 10 (StataCorp LP, College Station, TX, USA). A structural equation modelling (SEM) approach was chosen to allow direct statistical testing of a theoretical model. SEM has many benefits over traditional regression techniques, which include the ability to model equations simultaneously and the incorporation of latent variables. 30 SEM is a combination of confirmatory factor and path analysis, which allows for the inclusion of latent (unmeasured) variables. 31 This approach was used to build two models: the effect of FF outlet visits and food choices and the effect of FF exposure on consumption and BMI. The SEM analyses were undertaken in AMOS version 17. 0 (IBM SPSS, USA). The hypothesised model for food choices is shown in the results section (Figure 2). The observed variables are displayed as boxes and latent variables as circles. Each observed variable has an associated random error term and each latent variable has an associated disturbance term, which represents the variance in the latent variable that has not been explained by the observed variables associated with that latent variable. Regression paths are shown by singleheaded arrows and covariances by double-headed curved arrows. The model fit was assessed by two indices; the comparative fit index (CFI) and the root mean square error of approximation (RMSEA). The CFI is a comparison of the hypothesised model compared with an independence model where all parameters are assumed to be independent. The RMSEA gives an indication of ‘how well would the model, with unknown but optimally chosen values, fit the population covariance matrix if it were available’. 32 A combination of CFI40. 95 and a RMSEA of o0. 50 is a sign of good model fit. The w2-test of overall fit is very sensitive to large sample size so has not been used in these models. 30 The two models were constructed a priori using previous research. The nutritional content of chips, burgers, pizza and Fast food and body mass index LK Fraser et al 1327 pies are known to be high in saturated fat and energy and therefore are ‘unhealthy’,4–9,33 whereas fruit and vegetables are known to contain fibre and vitamins and so are classified as ‘healthy’. Exposure to FF outlets is known to be higher in areas of higher deprivation. 19–21 In the food choices model, unhealthy consumption (latent variable) was modelled from the frequency of consumption of chips, burger, pizza and pies (reported by the teenagers themselves), and the healthy consumption was modelled from the number of pieces of vegetables and raw fruit consumed by the teenager (maternal report). The number of times that the teenager visited a FF outlet (maternal report) was regressed on the unhealthy and healthy consumption variables. The model for the effect of FF exposure on consumption and BMISDS is shown in Figure 3. Here exposure is a latent variable modelled from maternal and paternal takeaway frequency and deprivation score. The exposure is regressed on the number of visits to FF outlet. The BMISDS at age 13 years is the main outcome of this model. Ethical approval for the study was obtained from the ALSPAC Law and Ethics Committee and the local research ethics committees. Results A total of 3620 participants have data for height and weight from the age 13 clinic and the frequency of FF outlet visits, and were included in these analyses (SEM cannot use individuals with missing data). A total of 1711 (47. 3%) were boys and 456 (12.6%) obese. The descriptive statistics are shown in Table 1. Frequency of visiting FF outlets and food consumption frequencies are shown in Figure 1. The results of model 1 are shown in Figure 2 with regression weights shown in Table 2. This model showed that increased frequency of eating at FF outlets was positively associated with higher consumption of unhealthy foods (b ? 0. 29, Po0. 001) and negatively associated with the consumption of healthy foods (b ? A1. 02, Po0. 001). The CFI for model 1 was 0. 98 and the RMSEA was 0. 05 (90% confidence interval 0. 044, 0. 058). These represent good approximate model fit. Table 1. The results of model 2 are shown in Figure 3 with regression weight shown in Table 3. This model showed that increased exposure to FF increased the frequency of visits to FF outlets (b ? 0. 61, Po0. 001), which in turn was associated with higher BMISDS (b ? 0. 08, Po0. 001). Deprivation was the largest contributing variable to the exposure (b ? 9. 2, Po0. 001). The CFI for model 2 was 0. 98, and the RMSEA was 0. 021 (90% confidence interval 0. 009, 0. 033). These represent very good approximate model fit. Discussion This study shows that teenagers who are exposed to more unhealthy foods at home are more likely to eat at FF restaurants and have a higher BMISDS. The negative association of increased visits to FF outlets on consumption of healthy foods (fruit and vegetables) has also been demonstrated. The FF restaurant use in this analysis was reported by the mother or main carer of the teenager and showed that nearly 60% of all the teenagers ate at a FF restaurant at least once a month. This appears to be less frequently than in the United States of America, where studies showed that 60% of older children and adolescents ate FF more than once per week34 and that B30% of children ate at a FF restaurant on any typical day. 9. As one part of the SEM this study showed that eating at a FF outlet was associated with a higher BMISDS. There were no previous UK studies to compare these results with, but previous studies from the United States of America have not found consistent results. Boutelle et al. 11 found no association between frequency of FF consumption and adolescent BMI or weight status, and an Australian study Descriptive statistics Mean BMISDS Deprivation (IMD 2007)29 Physical activity (c. p. m. ) Raw fruit (portions per week) Vegetables (portions per week) s. d. Median IQR 0. 29 13. 7 541 9. 5 9. 5 1. 14 11. 4 190 7 7 0. 024 10. 6 511 8 8 A0. 47, 1. 06 5. 9, 17. 0 404, 653 5, 14 5, 12 Abbreviations: BMISDS, body mass index standard deviation score for age and sex; c. p. m. , cycles per minute; IMD 2007, Index of Multiple Deprivation 2007; IQR, interquartile range. Figure 1 Food frequency data. International Journal of Obesity Fast food and body mass index LK Fraser et al 1328 Figure 2 Results of SEM model of food choices. Table 2 Results of SEM model of food choices Regression weights a Unhealthy’fast food Healthy’fast food Chips’unhealthy Burger’unhealthy Fruit’healthy Vegetables’healthy Pizza’unhealthy Pies’unhealthy Estimate s. e. CR P 0. 285 A1. 023 1. 000 0. 732 1. 000 1. 157 0. 774 0. 530 0. 021 0. 124 13. 439 A8. 274 o0. 001 o0. 001 0. 016 45. 243 o0. 001 0. 148 0. 018 0. 016 7. 802 42. 483 32. 720 o0. 001 o0. 001 o0. 001 Abbreviations: CR, critical ratio; SEM, structural equation modeling. aAll consumption variables units: never/rarely, once a month, once every 2 weeks, once or twice per week, 3–4 times a week, 5 or more times a week. showed that FF eaten at home (but not away from home) was associated with higher BMI in adolescents (MacFarlane). Two longitudinal studies using data from the CARDIA study found that higher FF intake in adolescence was associated with higher BMI in young adulthood12 and those who ate FF more than twice a week had put on an extra 4. 5 kg of weight 15 years later. 13 The teenagers who ate more frequently at FF restaurants were more likely to eat less fruit and vegetables, as well as consume more unhealthy foods (chips, burger, pizza, pies) than those teenagers who ate at FF restaurants less frequently. This is an indication that the consumption of unhealthy foods may displace healthy food choices. This is similar to previous research in the United States of America, International Journal of Obesity which showed that children who ate FF consumed 45 g less vegetables per day than children who did not eat FF. 10 At age 13 years the food frequency data were a combination of maternal and self-report from the teenagers, but the total macro- and micronutrient values could not be assessed in this study as these data were not yet available at the time of writing. Deprivation was the largest contributor to the FF exposure variable. This could be explained by the fact that those of higher deprivation eat more FF because of the relative cheapness of FF. It has also been shown in many studies in the United Kingdom and the United States of America that areas of higher deprivation have more FF outlets than more affluent areas therefore, FF is more readily available. 35 An interesting economics paper from the United States of America showed that increasing the cost of FF by $1 could decrease BMI by 0. 78 units. 36 The increased consumption of unhealthy foods (chips, burger, pizzas and pies) by those teenagers who ate more frequently at FF outlets was not surprising, but the associated negative effect of the consumption of fruit and vegetables by these participants is important. These teenagers will not only be consuming more of the saturated fat and salt from the burgers, and so on, but at the same time they are not consuming important nutrients from fruit and vegetables. Although many FF outlets now offer more healthy alternatives such as fruit and vegetables, the consumers may still be choosing the unhealthy foods. Fast food and body mass index LK Fraser et al 1329 The FF question completed by the carer did not specify what constituted FF so some respondents may only count large franchises as FF whereas others may use a broader definition that includes independent takeaways. Although the frequency of eating at a FF restaurant was asked, the carers were not asked about the food eaten from these establishments and many FF restaurants now offer more ‘healthy’ alternatives. Although the majority of FF items do not meet the Food Standards Agency nutrient standards for total fat, saturated fat, sugar and sodium there are wide variations in similar products from different FF outlets with sodium content varying by up to four times in fried chicken products. 37 Therefore, having data on which food items were consumed from which FF outlet would further enhance future studies. There was no information on why the teenagers ate at FF restaurants, and key questions for the future include; was there no alternative eating establishments in their neighbourhood? Did they prefer FF to other meals or was the cost of food important? Conclusions This study has shown that the teenagers who ate at FF restaurants consumed more unhealthy foods and were more likely to have higher BMISDS than those teenagers who did not eat frequently at FF restaurants. Teenagers who were exposed to more takeaway foods at home ate more frequently at FF restaurants. Eating at FF restaurants was also associated with lower intakes of vegetables and raw fruit in this cohort. Figure 3 The SEM model of FF exposure and BMI. Table 3 Results of SEM model of FF exposure and body mass index Regression weights Fast food ’exposure. Maternal fast food’exposure Deprivation’exposure Paternal fast food’exposure BMISDS’fast food BMISDS’c. p. m. a Estimate s. e. CR 0. 61 1. 000 9. 20 0. 66 0. 08 0. 00 0. 07 8. 654 1. 07 0. 08 0. 02 0. 00 8. 605 8. 680 3. 586 A3. 351 P o0. 001 o0. 001 o0. 001 o0. 001 o0. 001 Abbreviations: BMISDS, body mass index standard deviation score for age and sex; c. p. m. , cycles per minute; CR, critical ratio; FF, fast food; IMD 2007, Index of Multiple Deprivation 2007; SEM, structural equation modeling. a All consumption variables units: never/rarely, once a month, once every 2 weeks, once or twice per week, 3–4 times a week, 5 or more times a week. Strengths/limitations This is a large dataset with good-quality height and weight data taken at clinic visits by trained staff using validated equipment. There were food consumption data about the teenagers available from both the teenagers and their carers, but this is a cross-sectional study so causation cannot be implied from this data. As expected in a longitudinal study there is attrition and the subcohort used in this study may not be truly representative of the whole cohort. Conflict of interest The authors declare no conflict of interest. Acknowledgements. We are extremely grateful to all the families who took part in this study, the midwives for their help in recruiting and the whole ALSPAC team, which include interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists and nurses. The UK Medical Research Council (grant ref: 74882), The Wellcome Trust (grant ref: 076467) and the University of Bristol provide core support for ALSPAC. LKF was funded by ESRC/MRC studentship. References 1 Craig RS. Health survey for England 2007, 2008. Available from http://www. natcen. ac. uk/study/health-survey-for-england-2007. 2 Keynote.UK fast food and home delivery outlets, 2006. International Journal of Obesity Fast food and body mass index LK Fraser et al 1330 3 DeMaria AN. Of fast food and franchises. J Am Coll Cardiol 2003; 41: 1227–1228. 4 Astrup A. Super-sized and diabetic by frequent fast-food consumption? Lancet 2005; 365: 4–5. 5 Brown K, McIlveen H, Strugnell C. Young consumers and the hospitality spectrum. Appetite 1998; 31: 403. 6 Harnack LJ, French SA, Oakes JM, Story MT, Jeffery RW, Rydell SA. Effects of calorie labeling and value size pricing on fast food meal choices: results from an experimental trial. Int J Behav Nutr Phys Act 2008; 5: 63. 7 Lewis LB, Sloane DC, Nascimento LM, Diamant AL, Guinyard JJ, Yancey AK et al. African Americans’ access to healthy food options in South Los Angeles restaurants. Am J Public Health 2005; 95: 668–673. 8 Paeratakul S, Ferdinand DP, Champagne CM, Ryan DH, Bray GA. Fast-food consumption among US adults and children: dietary and nutrient intake profile. J Am Diet Assoc 2003; 103: 1332–1338. 9 Schmidt M, Affenito SG, Striegel-Moore R, Khoury PR, Barton B, Crawford P et al. Fast-food intake and diet quality in black and white girls the national heart, lung, and blood institute growth and health study. Arch Pediatr Adolesc Med 2005; 159: 626–631. 10 Bowman SA, Gortmaker SL, Ebbeling CB, Pereira MA, Ludwig DS. Effects of fast-food consumption on energy intake and diet quality among children in a national household survey. Pediatrics 2004; 113: 112–118. 11 Boutelle KN, Fulkerson JA, Neumark-Sztainer D, Story M, French SA. Fast food for family meals: relationships with parent and adolescent food intake, home food availability and weight status. Public Health Nutr 2007; 10: 16–23. 12 Duffey KJ, Gordon-Larsen P, Jacobs DR, Williams OD, Popkin BM. Differential associations of fast food and restaurant food consumption with 3-y change in body mass index: the Coronary Artery Risk Development in Young Adults Study. Am J Clin Nutr 2007; 85: 201–208. 13 Pereira MA, Kartashov AI, Ebbeling CB, Van Horn L, Slattery M, Jacobs DR et al. Fast-food habits, weight gain, and insulin resistance (the CARDIA study): 15-year prospective analysis. Lancet 2005; 365: 36–42. 14 Sutherland LA, MacKenzie T, Purvis LA, Dalton M. Prevalence of food and beverage brands in movies: 1996–2005. Pediatrics 2010; 125: 468–474. 15 Powell LM, Szczypka G, Chaloupka FJ. Trends in exposure to television food advertisements among children and adolescents in the United States. Arch Pediatr Adolesc Med 2010; 164: 794–802. 16 Hillier A, Cole BL, Smith TE, Yancey AK, Williams JD, Grier SA et al. Clustering of unhealthy outdoor advertisements around child-serving institutions: a comparison of three cities. Health Place 2009; 15: 935–945. 17 Lingas EO, Dorfman L, Bukofzer E. Nutrition content of food and beverage products on Web sites popular with children. 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Chemical Synthesis of a Gene: Phosphodiester Approach

Chemical Synthesis of a Gene: Phosphodiester Approach Chemical synthesis of a gene is the process of synthesizing an artificially designed gene into a physical DNA sequence by chemical methods. The amino acid sequence of the protein encoded by a gene enables the deduction of base sequence of the concerned gene. From the amino acid sequence of the protein and using a set of optimal codons, the nucleotide sequence of the gene can be back translated. However, the degeneracy of genetic code may present some problems, but a functional sequence of the gene can nonetheless be worked out and can be optimized for codon usage as well as for base composition. In principle, a DNA synthesizer can be used to synthesize the DNA sequence chemically and this can be cloned in the usual manner. But this is not so simple. A synthesizer will add bases sequentially one at a time to the growing oligonucleotide chain through a series of chemical reactions and washing steps. Synthesis of oligonucleotides 30-50 bases long is very reliable, longer sequences can be synthesized but the practical limit is not more than 100 bases. One way to solve this is to synthesize short fragments and join them chemically or enzymatically to create the longer fragment. However, the synthesizer makes single-stranded DNA, so the complementary strand has to be synthesized again to create a double-stranded DNA. It involves a lot of work but is achievable. Early studies. The synthesis of nucleic acids in the laboratory started about thirty years ago. Early synthetic efforts used phosphodiester approach which enabled the synthesis of short oligonucleotides of 10-20 nucleotides. This approach was based on the selection of the proper condensing agents for phosphodiester bond formation and at the same time suitable protective groups were employed for the bases and the ribose moiety. These oligonucleotides were then assembled into longer DNA fragments with the help of kinase and DNA ligase. From the known primary structure of a ribonucleic acid, tyrosine tRNA, Dr H Khorana and his colleagues deduced the DNA sequence and synthesized successfully a DNA segment containing 200 bp coding for the structural gene for tyrosine tRNA. However, the low yields in the condensation step, the long reaction times, and especially the time-consuming purification of intermediates led to believe that chemical gene synthesis is unlikely to become a standard lab oratory method. Since then, the procedure for oligonucleotide synthesis has been improved by several workers and they provide different approaches for synthesis as well as protection of bases and sugar moieties. There are three distinct methods: (1) phosphodiester approach, (2) phosphotriester or phosphate triester approach and (3) phosphite triester or phosphoramidite approach. Phosphodiester approach This method involves the formation of an ester linkage between an activated phosphate group of one nucleotide with the hydroxyl group of another nucleoside, thus forming the natural phosphodiester bridge between the 5-OH of one nucleoside unit and the 3-OH of the next. Here, 3-O-acetylnucleoside-5-O-phosphate (a) is activated by N,N-dicyclo- hexylcarbodiimide (DCC) or p-toluenesulphonylchloride(PTS/PTsCl) and subjected to react with a 5-O-protected nucleoside (b) to give a protected dinucleoside monophosphate or phosphodiester (c). Activation of phosphate moiety is essential for easier formation of the phosphodiester linkage and this is mediated by DCC or PTsCl. Now, to increase the chain length, one has to remove the 3-O-acetyl group by base catalysed hydrolysis. Further chain elongation is carried out by repeating the process. The major drawback of the phosphodiester method is the formation of pyrophosphate oligomers and oligonucleotides branched at the internucleosidic phosphate. Phosphotriester approach In this method, oligonucleotide branch formation is avoided by protecting the phosphate group with an ethylcyano group. A nucleotide containing 5-OH protected and phosphate protected by MMT and 2-cyanoethyl group respectively (compound a) is activated with 2,4,6-Triisopropylbenzenesulfonyl chloride (TPSCl) and subjected to reaction with a 3-O-protected nucleoside (b). This generates a dinucleoside monophosphate or phosphotriester (c) in which phosphate group is protected by 2-cyanoethyl group. The basic difference between phosphodiester and phosphotriester method is that, in phosphodiester method, the phosphate group is protected by two phosphoester linkage but in phosphotriester method the phosphate group is protected by one extra phosphoester linkage with 2-cyanoethyl group. In phosphotriester method, the formation of oligonucleotide branch at the internucleosidic phosphate is avoided. Phosphite triester or phosphoramidite approach The phosphite triester or phosphoramidite approach for oligonucleotide synthesis was based upon the use of phosphoramidite monomers and the use of tetrazole catalysis. In phosphite triester method, the starting compound is N-6-benzoyldeoxyadenosinephosphoramidite (if adenine is the first base) where the phosphorous atom is in the +3 oxidation state. So unlike the other methods, the formation of oligonucleotides branch is not possible in this process. In this approach, the oligonucleotide is synthesized by a series of reactions described below. Protection of base and sugar In this step, the free -NH2 group of the bases are protected by benzoylation or acylation depending upon the nature of bases. The 5-hydroxyl group is also protected by dimethoxytrityl group (DMT), which protects only primary hydroxyl group but not secondary. The reactions are illustrated in CSG_Fig 3., the blocked bases are shown in the inset. Formation of phosphite triester or phosphoramidite In this step phosphite triester is synthesized by a series of reactions. First, 2-cyanoethanol on reaction with phosphorus trichloride produces an intermediate compound which on further reaction with di-isopropylamine (two-equivalent) and 5-OH protected nucleoside (one-equivalent) produces phosphite triester (CSG_Fig 4). This phosphoramidite will be repeatedly used during the oligonucleotide synthesis process described below. The synthesis procedure The synthesis is carried out in several steps described below: Step 1: The deblocking step The first base, which is attached to the solid support, is at first inactive because all the active sites have been blocked or protected. The free -NH2 groups in the bases remains protected by benzoylation or acylation depending upon the bases and the -OH group is protected by dimethoxytrityl group (DMT). To add the next base, the DMT group protecting the 5-hydroxyl group must be removed (deblocking). This step is also called detritylation. This is done by adding either dichloroacetic acid (DCA) or trichloroacetic acid (TCA) in dichloromethane (DCM), to the reaction column. The 5-hydroxyl group is now the only reactive group on the base monomer. This ensures that the addition of the next base will only bind to that site. The reaction column is then washed to remove any extra acid and by-products. Step 2: Base condensation The step2 is basically a condensation step. Now prior to addition of the well protected nucleotide to the column, it is essential to activate the phosphate group, so that the nucleophilic attack on phosphorous atom takes place easily. This is best done by adding tetrazole to the nucleotide in dichloromethane medium. In presence of tetrazole, diisopropylamine group of the nucleotide becomes positively charged and hence its departure would be easier after nucleophilic attack of 5-hydroxyl group of the previous nucleotide which is attached with resin column. After the reaction, the column was washed to remove extra tetrazole, unbound nucleotide and byproduct (diisopropylamine). Step 3: Capping In case of unreacted nucleoside attached with resin, the 5-hydroxyl group is unprotected this may react later with the addition of different nucleotides. If left unprotected, it will lead to the formation of a mixture of oligonucleotides. The 5-hydroxyl group is therefore blocked by adding acetic anhydride and N-methylimidazole (capping). After capping, the reaction column is thoroughly washed to remove extra acetic anhydride and N-methylimidazole. Step 4: Oxidation This step is basically an oxidation step. In this step, the phosphite linkage is oxidized to give more stable phosphate linkage. The oxidation is best done by adding a mixture of dilute aqueous iodine solution, pyridine (Py) and tetrahydorfuran (THF) to the reaction column. The steps one through four, i.e., deblocking, base condensation, capping and oxidation, are repeated until all desired bases have been added to the column. This cycle is completed once for each additional base. Step 5 Detachment of oligonucleotide from solid support After all bases have been added the oligonucletide must be cleaved from the solid support and deprotected before it can be effectively used. For detachment of oligonucleotides form resin, the column is treated with 28% ammonium hydroxide solution (NH4OH), and at the same time the ethylcyano group on the phosphate group is removed. Step 6: Purification and isolation of oligonucleotide In this step, NH4OH is evaporated from the ammonium hydroxide solution of oligonucleotides to get crude product. The crude product is a mixture of oligonucleotide, cleaved protective groups and oligonucleotides with internal deletions. Now this crude product is subjected to boiling in a sealed tube with NH4OH at 55 °C. The main purpose of this reaction is to remove the base protecting group. After evaporation of NH4OH, the crude product is subjected to desalting followed by Polyacrylamide Gel Electrophoresis, to purify the oligonucleotides. Desalting is used mainly to remove the ammonium ion. This is done by ethanol precipitation, size-exclusion chromatography, or reverse-phase chromatography. Oligonucleotides are synthesized by the stepwise addition of nucleoside-3à ¢Ã¢â€š ¬Ã‚ ²-phosphoramidite monomers to solid-phase supports in an automated DNA synthesizer. In solid-phase synthesis, 3-terminal hydroxy group of the first added nucleoside is attached to the solid surface by covalent interaction. The solid support is contained in columns whose dimensions depend on the scale of synthesis. The two most frequently used solid phase materials are Control Pore Glass (CPG) and macroporous polystyrene (MPPS). CPG is commonly defined by its pore size, for example pore sizes of 500Ã… are used to allow the oligonucleotides preparation of about 50 -mer. To improve the performance of native CPG some modification is required. This is done by treating the material with (3-aminopropyl)triethoxysilane) to give Aminopropyl CPG. The amino group then serves as the anchoring point for the first added oligonucleoside. MPPS is synthesized by polymerization of divinylbenzene, styrene, and 4-chloromethylstyrene in the presence of a porogeneous agent. It is a low-swellable, highly cross-linked polystyrene and suitable for oligonucleotide synthesis. The macroporous chloromethyl MPPS obtained is often converted to aminomethyl MPPS to improve the efficiency of the support. Annealing of oligonucleotides For chemically synthesize a gene, the next step will be to assemble the oligonucleotides to form a complete gene. This is achieved by enzymatic methods which include polymerase cycling and ligase reactions. Some of the strategies are discussed below. Assembling oligonucleotides by single-step PCR. For synthesis of a gene, the oligonucleotides (about 30-60 nt long) are synthesized chemically so that each oligonucleotide has a 6-9 nt overlap with its neighboring oligonucleotide. These are then assembled in a single-step PCR. In this method, oligonucleotides are first ligated and then the product, the entire gene, is PCR amplified using the outmost oligonucleotides as primers. This method was first used to synthesize a 924-bp gene coding for an isozyme of horseradish peroxidase. Another method was developed by WPC Stemmer which did not use any ligase for joining the oligonucleotide products. It however, relied on Taq DNA polymerase (PCR cycling) for joining the individual oligonucleotides. Assembling oligonucleotides by two-step PCR. The method involves two steps. (i) Synthesis of individual fragments of the DNA of interest: ten to twelve 60mer oligonucleotides with 20 bp overlap are mixed and a PCR reaction is carried out with high-fidelity DNA polymerase Pfu to produce DNA fragments that are 500 bp in length. (ii) Synthesis of the entire sequence of the DNA of interest: five to ten PCR products from the first step are combined and used as the template for a second PCR reaction using high-fidelity DNA polymerase pyrobest, with the two outermost oligonucleotides as primers. Several modifications of the above procedure have been presented. One such method called PAS (PCR-based accurate synthesis) involves (i) synthesis of oligonucleotides to cover the entire DNA sequence (ii) PCR to synthesize DNA fragments (iii) second PCR for assembly of the products of the first PCR and (iv) cloning of the synthetic DNA and then verification by DNA sequencing. Besides, other methods in use for gene synthesis are successive extension PCR, simplified gene synthesis (PCR based), synthons and ligation by selection, to name a few. Review questions and problems What is the advantage of phosphatetriester method over phosphatediester method? What is the advantage of phosphitetriester method over phosphatetriester and  phosphatediester method? What is the main advantage to use DMTCl for protecting the 5-hydroxyl group? How could you attach the first nucleoside to the solid support? What is the utility of capping step in the oligonucleotides synthesis? Why capping is done by aceticanhydride? What is the function of iodine in the oxidation step of oligonucleotides synthesis? How could you protect only the free -NH2 group of the bases of a nucleoside? What is the reagent used for the removal of 2-cyanoethyl group from the  synthesized oligonucleotides? What is the byproduct produced from the base-condensation step of oligonucleotides  synthesis in phosphite triester method? How could you deprotect the bases of oligonucleotides? What is the function of tetrazole in the base condensation step of oligonucleotide synthesis? What is the basic principle for synthesizing a gene from the corresponding oligonucleotides by (a) PCR-based one-step DNA synthesis, (b) PCR-based two-step DNA synthesis?