Drug safety assessment

Drug safety assessment INTRODUCTION Pre-clinical studies or pre-clinical trials are very important stage of research in drug development process. Pre-clinical trials are also known as non-clinical safety assessment. The main purpose of carrying out these studies is to ensure that the test compound is safe before testing in humans (clinical trials), characterise toxicity and target organs, to fulfil regulatory requirements and to protect employees in manufacturing. In other words, quality, safety and efficacy of a test compound are determined during pre-clinical studies. Animals such as rodents (mice, rat) and non-rodent (monkey, dog) are used in pre-clinical trials before administration to humans (clinical trial phase) so as to separate efficacy from toxicity in human volunteers. The international conferences on harmonisation (ICH) for drug development are regulatory authorities which provide instructions for development and registration of new chemical entities (NCE) likewise instructions for carrying out assessment i n animals. The concept of the 3Rs (Reduction, Refinement and Replacement) is widely employed by ICH for pharmaceutical industries to comply. This concept is employed so as to reduce the numbers of animals and also to avoid prolonged testing period. Anti-arthritis drug are used to treat arthritis (inflammation of joints). Important pre-clinical tests required include general toxicology, safety pharmacology, reproductive toxicology, carcinogenicity studies and genetic toxicology . PRE-CLINICAL TESTS Test for Carcinogenicity Carcinogenicity The carcinogenicity study evaluates the carcinogenic potential of the compound. During pre-clinical studies, animals are used firstly so as to determine the potential risk of the anti-arthritis drug in humans. In order to evaluate carcinogenicity, two types of studies are conducted which are the short-term study and the long-term study. The short-term study involves using the four transgenic models. The four transgenic models used are inactivated tumour suppressor gene (p53+/- model), activated oncogene (Tg.Ac model and rasH2) and inactivated DNA repair gene (XPA-1-model). The genetic alterations of the four transgenic models are made in relation to carcinogenesis processes. The long-term study involves the use of mice or rats of both sexes and is usually a two years study. The correlation between rats to humans is about 70% and is more sensitive making them the major specie of animal used for the long-term carcinogenicity studies. Spragne-daweley has high chances of survival and as a result, these strains of rats are required for the 2years bioassay. Treated animals are divided into three groups each containing about 50-100 animals per sex. In rats, the treated groups are observed for 24months while 18months in mice. Large numbers of animal are used for this study because continuous dosing of the drug could induce tumour and also to achieve a strong statistical result. Furthermore, non-genotoxic carcinogens can cause some rodent strains to be susceptible to tumour induction and in order to distinguish rodent specific processes related to human, understanding carcinogenesis mechanisms based on the specificity of tissues is very vital. Genotoxicity Test Genotoxicity test is carried out so as to determine whether the anti-arthritis drug can cause genetic damage. The genotoxicity test required include; mouse lymphoma assay (MLA) otherwise known as in vitro mammalian cell clastogenecity, the Bruce Ames test (Ames test) and mouse micronuclei assay. These tests detects whether the anti-arthritis can cause alterations in chromosome and damage to DNA leading to genetic mutation and ultimately results in malignant tumour (cancerous cell).The Ames test is commonly used for the genotoxicity test and it detects whether the drug is genotoxic. This occurs by causing back mutation in bacteria colonies and it takes up to about 48hours . Gene mutation, clastogenecity of a genotoxic compound and chromosomal aberrations are determined via the mouse lymphoma assay (MLA) or in vitro mammalian cell clastogenecity. The MLA requires between 2-3weeks and can either give a negative result to the Ames test or not detected at all. An additional test used in g enotoxicity testing is the mouse micronuclei assay which is an in vivo study. This is required because regulatory authorities (ICH) requires both in vitro and in vivo test. The process of ADME of the anti-arthritis drug is used to detect genotoxicity via the mouse micronuclei assay. After performing all the three tests discussed and the anti-arthritis drug remains positive to all, then the drug is probably carcinogenic to humans. Test for Organ Toxicity and Biochemical Dysregulation Safety Pharmacology Safety pharmacology of the anti-arthritis drug is required to detect target organ toxicity such as cardiovascular, central nervous, respiratory, renal and gastrointestinal system. Rodents (such as mice and rats) and non-rodents (such as guinea pigs and dogs) are required or used for safety pharmacology test. Rats or mice are required for CNS and respiratory studies while dog is required for cardiovascular studies. The pharmacological activity of the anti-arthritis drug is determined by carrying out the ligand binding assay which makes in vitro studies preferable to in vivo studies. In safety pharmacology studies, the animals are divided into four groups, three treated group and one control group. The maximum number of rats required per group is fifteen and four dogs group. The duration of dosage in safety pharmacology studies is usually one month . The ICH (S7A) perspective on cardiovascular safety pharmacology required core battery studies and follow up studies. Some of the core bat tery studies include heart rate, electrocardiogram and blood pressure must be evaluated. In vitro and in vivo evaluations, conductance abnormalities including methods for assessing repolarisation must be put into consideration . Some of the follow up studies include vascular resistance, cardiac output, the effects of exogenous and/or endogenous compound on the cardiovascular responses and so on . General Toxicity studies General toxicology test is required for dose determination for No observed effect level (NOEL). The acute toxicity test is also known single dose toxicity and is required to assess biochemical dysregulation and also to determine the levels at which the anti-arthritis drug could cause an adverse reaction. The animals used for general toxicity test are rats and dogs and are usually dosed between 14-28days. Change in organ weight, histopathology, mortality rate, clinical pathology and necropsy are the parameters required to assess toxicity.General toxicology must be done before one month of reproductive studies. Reproductive Toxicity Studies The aim of reproductive toxicity studies is to reveal any effect of the anti-arthritis drug on mammalian reproduction. Rats and rabbits are the most commonly used and widely accepted animal. Rabbits are used because semen is easily collected. The ICH study design for reproductive toxicity studies include fertility and early embryonic development to implantation (rabbits dosed from day 6-18, rats dosed from day 6-15), organogenesis otherwise known as embryo-foetal development and pre and post-natal development (treatment last for 15gestation days and 21lactation days).The study design for fertility and early embryonic development studies requires four groups of 20males and 20females animal. Also, the study design for embryo-foetal development generally have four groups of 20rats or 20rabbits and ICH require evaluation of 16 to 20litters to provide a degree of consistency between studies [8; 9; 12; 13; 14]. Information derived from acute and repeated dose toxicity studies of at least o ne month are required before reproductive toxicology. Conclusion Pre-clinical studies must be carried out before clinical trials so as to protect human volunteers. All the studies described above determine how competent the anti-arthritis drug is before proceeding to clinical trials. All the regulations provided by ICH are widely used most especially the concept of 3Rs. Safety, quality and efficacy are the main objectives for carrying out preclinical studies. Some of the test required during preclinical studies includes carcinogenicity test which involves the short term and long term studies, genotoxicity test, reproductive test, safety pharmacology, renal toxicity test, cardiovascular toxicity test, general toxicity test and neurotoxicity test (functional observation battery test). REFERENCES ICH harmonised tripartite guideline, Dose selection for carcinogenicity studies of pharmaceuticals S1C(R2). Available at: http://www.ema.europa.eu/pdfs/human/ich/038395en.pdf ICH harmonised tripartite guideline, Guidance on specific aspects of regulatory genotoxicity tests for pharmaceuticals S2A Available at: http://www.bcg-usa.com/regulatory/docs/ich/ICHS2A.pdf ICH harmonised tripartite guideline, Safety pharmacology studies for human pharmaceuticals S7A. Available at: http://www.tga.gov.au/docs/pdf/euguide/ich/053900en.pdf G.B. Jena et al., 2001, Genotoxicity testing, a regulatory requirement for drug discovery and development: impact of ICH guidelines, Indian Journal of Pharmacology. David J. Tweats 1998, Impact of ICH guidelines on genotoxicity testing, PSTT Vol 1, No. 5. ICH harmonised tripartite guideline, Guideline on the need for carcinogenicity studies of pharmaceuticals S1A. Available at: http://www.bcg-usa.com/regulatory/docs/ich/ICHS1A.pdf Guideline for industry, The need for long-term rodent carcinogenicity studies of pharmaceuticals. Availableat: http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm074911.pdf ICH M3; Timing of pre-clinical studies in relation to clinical trials (see safety topics). Available at: http://www.ich.org/cache/compo/276-254-1.html Preclinical toxicology: Points to consider in programme design. Available at: http://www.pacificbiolabs.com/preclinical James L. Stevens, (2006). Future of toxicology mechanisms of toxicity and drug safety: where do we go from here? Chem. Res. Toxicol., 19, 1393-1401. Yasuo Ohno, (2002). ICH Guidelines-Implementation of the 3Rs: Incorporating Best Scientific Practices into the regulatory Process. Regulatory Testing and Animal Welfare. ILAR Journal V43 Supplement 2002. Lecture notes by Dr Jean-Pierre Valentin, Director Safety Pharmacology, Safety Assessment UK, AstraZeneca. Lecture notes by Dr Lorna M. Burns, Sequani limited, Ledbury, Herefordshire Lecture notes by Dr M. Kelly.

Estimated Heat Distribution by Convection in Water Essay

Introduction This report assesses the distribution of heat by convection in water to estimate the heat conductivity of water. The transfer of heat from a heating coil to a fluid is conduction but the heat transfer within the fluid is convection. This is basically fluid flow of particles arising from nature, heat, chemical or kinetics. The distribution of heat is assessed with various factors introduced. In this case a magnetic stirrer and a motor. This report presents an estimate of the effect of free and forced convention on the distribution of heat in water. Experimental method The apparatus were arranged as shown in fig. 1. A beaker of five litre capacity was places on a motor, four litres (4L) of cold water was put in a beaker. A heating coil and three thermometers were placed at various depths in the beaker of water and their various distances from the base of the beaker were recorded. Power was supplied to the motor and heating coil and at intervals of four minutes each; the temperatures on all three thermometers were read simultaneously. After four successful readings, the electricity supply was disconnected and the ambient temperature was recorded. This same procedure was repeated twice, the first with a magnetic stirrer and the next time without the magnetic stirrer but the motor operating. Distance from base (m) Temperature (C) Heating Coil 0.08 – T1 0.02 24 T 2 0.09 24 T 3 0.12 24 Table 1. Distances of apparatus and initial temperature readings of the water. Table 1 shows the ambient temperature readings collected before the experiment was carried out. It also shows the positions of the heating coil and thermometers from the base of the of the beaker. Results The time was kept in minutes to measure the intervals at which readings were taken. The temperature of the water was measured with thermometers in degreed Celsius and recalculated in degrees Kelvin and the positions of the heating coil and thermometers were also measured in meters. Time (minutes) T1 (0.02m) T2 (0.09m) T3 (0.12m) 0 24 24 24 4 24 28 32 8 24 39 42 12 24 46 49 16 24 54 56 Table 2: Free convection Time (minutes) T1 (0.02m) T2 (0.09m) T3 (0.12m) 0 20 20 20 4 26 26 26 8 32 32 32 12 37 37 37 16 42 42 42 Table 3: Forced convection (stirrer and motor) Time (minutes) T1 (0.02m) T2 (0.09m) T3 (0.12m) 0 20 20 20 4 20 29 32 8 21 36 38 12 21 44 46 16 22 51 54 Table 4: Forced convection (motor only) Fig 2: Free convection Fig 3: Forced convection (stirrer and motor) Fig 4: Forced convection (motor only) The readings and results derived from the experiment are being used to calculate an estimate amount of energy input and compare it with the theoretical value. Q represents energy input represents the power input t represents the duration for which the water was heated at 220v = 300w, but since 240v was used corrected value of = 300 240220 = 358 w = 16 minutes60 = 960s = 327.3960 = 314208J = 314.2 KJ Experiment 1. Free convection Assuming density of water to be 1000kg/m3 Cp = 4.18KJ/kgK = 24 – 24 = 0 = 54 – 24 = 30 = 56 – 24 = 32 = 4/34.18(0 +30 +32) = 345.55KJ Experiment 2. Forced convection (stirrer and motor) = 42 – 20 =22 = 42 – 20 =22 = 42 – 20 =22 = 4/34.18(22 +22 +22) = 367.84KJ Experiment 3. Forced convection (motor only) = 22 – 20 = 2 = 51 – 20 = 31 = 54 – 20 = 34 = 4/34.18(2 +31 +34) = 373.41KJ Estimates of errors involved in this experiment are a follows:- Time = 1 second in 60 seconds Length = 0.01 meters of 0.1 meters Temperature = 1 C Discussion In the experiment that involved forced convection from both the motor and stirrer the heat distribution was better and more accurate. This can be confirmed by the comparison of the energy input calculated based on experimental values with the energy input calculated based on the theoretical values. Readings to support this is shown in Table 3 and fig 3. A poor distribution of heat occurred in the first experiment where the water was heated freely. This is represented in Table 2 and figure 2 and by comparison of the experimental and theoretical values of the energy inputs. In experiment 3 where only the motor was used the graph 3 and figure 4 shows a better distribution of heat compared to experiment 1. Conclusion In a freely heated body of water, higher temperatures are taken from closer to the surface and lower temperatures towards the bottom. With introduction of kinetic energy from the stirrer and motor, the velocity of fluid flow increased thereby increasing the rate of heat transfer and the even distribution of heat through the water. This shows that water is a poor conductor of heat energy if heated with free convection.

Rationale – I have decided to study the gender-oriented issue of conjugal roles in the family

I have decided to study the gender-oriented issue of conjugal roles in the family. This area of sociological interest came about when we looked at family life and the symmetrical family. Another reason for my interest in this is it is still an issue despite all the changes such as sex discrimination, and even though feminists have raised the issue it seems that there is still not equality in the allocation of domestic tasks between husband and wife. The Lancaster Regionalism Group found an increase in men's participation but not in the unpopular chores, while Alan Warde suggests that the nature of household tasks varied between couples. From this evidence I derived my hypothesis â€Å"Men do help around the home but do not make an equal contribution†. Primary research will be used and will take the form of a diary. For my variables my sample size will be ten married / cohabiting couples. Both male and female will be in full time employment aged between 30 to 40, as I have access to these respondents. They will be chosen using a snowballing method. A quantitative method will be used to measure the time spent on tasks around the home, and the nature of tasks performed. CONTEXT. The issue of the domestic division of labour was raised by feminists like Ann Oakley in her study â€Å"The sociology of Housework† in which she argued that housework should be taken seriously as a type of â€Å"work†. Other feminists have developed this theme and looked at ways in which women experience inequality in the home. My first source is drawn from the Lancaster Regionalism Group's investigation into the household division of labour in Northwest England in 1988. This concept â€Å"domestic division of labour† is crucial because it relates to my aim. The â€Å"domestic division of labour† describes the way in which household tasks are allocated in the home. These researchers found that husbands tend to do a very much larger proportion of tasks concerned with the home such as car maintenance etc. However the women do the vast amount of domestic chores. The Lancaster researchers examined the popularity of different household chores. They wanted to test whether the male or female partner was likely to get the unpopular job. From their list of 20 tasks ironing, washing clothes and dishes were chosen as the most disliked chores. Although men had last washed the dishes in 23% of households, only 5% had done the ironing and 3% had last cleaned the dishes. The least pleasant of all tasks cleaning the toilet was last done in 81% of households by women. The Lancaster Regionalism Group concluded that there was some evidence that attitudes had changed but the actual pattern of behaviour remains much the same as it was in the earlier generation. The Lancaster Regionalism Groups work links in with my own hypothesis because the study found an increase in men's participation but not in the unpopular chores. Secondly there is the feminist approach to the domestic division of labour. The feminist Ann Oakley argued that the social scientists who claimed it was natural for women to take a caring role in the family e.g. perform household tasks had been tricked by their own prejudices into assuming what it meant to be a woman. Some contemporary sociologists have taken Stoller's argument and suggest that women take on more domestic responsibilities in any given household because it is seen as culturally appropriate feminine behaviour. Therefore it is difficult to discover whether the sharing (or not) of domestic tasks can be seen as a true measure of â€Å"equality†. My third source is drawn from Gershunys study on domestic division of labour. He measured changes in the domestic division of labour by looking at the use of time in the household. He investigated the dual burden hypothesis, which states that even when women take up professional work, they continue to carry on the domestic work. Gershuny found that over the period of 1974-5 to 1987 the husbands of working women continued to do less than half the total paid and unpaid work done by their spouses. However in some types of household's men did contribute equally and husbands share of work had risen. This source is relevant to my hypothesis because the source concludes there is evidence to show that men were taking on more mundane tasks as done by women, but such tasks continued to be the female's responsibility. My next source is the article † Domestic divisions of labour† by Alan Warde.The source concerns the aspect of women's two roles, their conventional responsibility for housework and paid work. According to the study where wives are involved in paid employment they spend fewer hours, on housework where men seem to be doing more. Nevertheless, women still do a greater share of domestic work. There is a strong gender division of tasks, with women doing routine household jobs. The article concludes that the traditional patterns remain very much in evidence and the rate at which men are learning to do female tasks may be slower than that at which women are learning to do male tasks like plastering etc. This source is relevant to my study because selected tasks between husband and wife remain much the same, women doing more housework and men doing painting etc. My final source is once again on the domestic division of labour by Madeleine Leonard. The article suggests that housework remains women's work. Research shows that there is a clear gender division of labour in housework tasks just like the Lancashire Regionalism group found in their study. This source is relevant to my study because it suggests that even though men are making a contribution when it comes to chores they are still not doing an equal share. These studies suggest that, despite much greater equality for women there is still an imbalance of responsibility when it comes to household chores. However my own research may suggest otherwise. Methodology Three main areas need to be covered for this research. Firstly, there needs to be a way of measuring the amount of domestic labour performed by females and males in the present day family groups. I have decided to measure who does what around the home. Secondly I will be measuring the tasks done with others and the time spent on chores. The principal research method I will use will be a diary, as I believe this is a more original method for this research. Not only will this method give me a greater validity but also an insight into the issue. I also hope it will identify trends within my sample group about the amount of housework performed. Using the diary method will also enable me to replicate Wilmott and Youngs approach, as they too used a diary method in their study of the â€Å"symmetrical family† where they asked respondents to keep a diary detailing the hours spent on paid and unpaid work. My sample will consist of 10 couple's aged between 30 to 40 who are all employed. They will be chosen using the snowballing method. Using this method offers a wide range of advantages for example it will enable me to obtain a relevant sample without having a sampling frame. The diary method will involve asking my respondents to keep a strict diary recording and detailing the amount of domestic labour they performed throughout the day, as well tasks done alone and the time spent on chores. When using these method respondents would need to keep this diary for up to a week. The diary will offer the opportunity to let the respondents record their account of the domestic labour performed without causing any bias, and so it will be a more reliable source. An example of sociological research that has used a diary method is Wilmott and Young's study of the symmetrical family where they asked respondents to keep a diary detailing the hours spent on paid and unpaid work. Another study example where a diary method has been used is Ann Oakley's study on the sociology of housework. Oakley asked respondents to keep a housework diary, revealing for the feminist debate the hard work and long hours housework demands. The advantage of using the diary method is qualitative data can discover peoples meaning and interpretations and can often also be examined systematically to identify patterns by using content analysis. This approach is favoured because it is free of values and scientific. Another advantage of using the diary method is it is a more reliable source when it comes to ethical issues, as respondents will not be influenced when recording the amount of work performed & will not reveal aspects of their lives they wish to remain hidden. One of the other reasons why I decided to use the diary method is it does not limit the resource-based area of time and money. The diary method will enable me to collect informative, relevant and original data whilst remaining within practical constraints. The diary method reflects two major methodological disadvantages selectivity and it is typical. The selectivity issue is a problem because the respondent will decide what is included not me the researcher. This could lead to irrelevance and inaccuracy & a difficulty in comparing data from different respondents. However to over come this disadvantage I will divide the diary into three categories to specify what sort of things to include. However this solution may too be a disadvantage as I am using a qualitative method this may lead to bias because I am imposing a framework on the respondent. The second disadvantage is typical because I do not know the amount of confidence I can have in the usualness of the day recorded. Most people's lives follow regular patterns but if my diary period of ten days is untypical then my picture as the researcher will be distorted. EVIDENCE. Despite the progress made by women in the twentieth century, which has brought about a substantial amount of change and has put an end to inequality and discrimination between sexes in many areas, women have still not won the battle of equality between men when it comes to domestic work in the home. When talking about work, it can be assumed that this refers to paid employment. However there is one job which is performed full time by women more than men, which is housework or domestic labour. My research concludes that domestic work done by women is hardly ever recognised. For instance respondent A had done more hours of domestic work in a week compared to her husband respondent k (refer to appendix). From my diary I can estimate women spend an average of fifty hours a week on housework which is far more than most people spend in paid employment. Men seemed to be doing less than this amount of domestic work compared to their wives, in some days doing less than half what they consider to be housework or related tasks. I have found from my diaries that housework is still seen as the main responsibility of women even though both partners are working in full time paid employment. It is still women who take on the main responsibility for housework from all the ten couples who took part in my experiment. My findings show that women still have an unequal role with men in the homestead. Much of this inequality arises because the central role of women is still seen by a male dominated society as that of housewife and mother. For instance a similarity I found in my study was that nearly all the female respondents who took part carried out similar tasks over one week such as cleaning the toilet, cooking and hovering etc. Whereas the male respondents tasks where also similar for instance gardening and painting etc. This may suggest that many jobs are still seen as men's job and women's job. This compares with the Lancaster Regionalism Group's study. This study showed that 80%of women were responsible for general domestic duties such as cleaning the toilet and only 31% of men took full responsibility for work to be done in the homestead. This tells me about my aims that many full time working women have two jobs in comparison to the men's one job. My own findings reveal that although a wide range of jobs and opportunities are available to women the main role of a woman's life is expected to be that of housewife. Although out of the 10 couples who took part in my experiment only 2% shared the responsibility of housework equally. This compares with Gershuney's study because he found that in some types of households men did contribute equally. The only difference, which was clear in my study, was that attitudes to domestic chores are changing. Respondents k and L(refer to appendix) were doing tasks such as cooking, making the tea etc all tasks done by women out of the other couples who took part in my experiment. This for instance compares to Gershuney's study because he found men were taking on more mundane tasks as done by women. The process of conducting my research went well although I would make a number of changes if I were to carry the experiment out again. For instance I decided that half an hour would be suitable and a long enough space of time for respondents to record the tasks done. I now think that this time period was not suitable, as this was too short. People may spend longer than half an hour on certain tasks such as hovering and so this may not have been recorded in the diary. I believe that forty-five minutes would have been a longer space of time. However if I had decided to choose to go with more than forty five minutes than respondents may not choose to record tasks that take them less than five minutes for example putting the rubbish out. After carrying out the experiment the ten couples who took part said they found it difficult recording what they thought was a task. Questions raised from the respondents included would walking the dog and taking the kids to school be considered a task?. To overcome this problem I could list about twenty tasks such as hovering, and other possible variations on a cover sheet and attach it to the diary and instruct respondents to record only the tasks on the cover sheet. I found that some respondents were recording gardening, and painting etc the problem with this is some people may choose to do gardening or painting as a hobby so these can not be recorded as chores. Again using a cover sheet could solve this problem. From my diaries I found that men were spending only half an hour on tasks when doing it on there own. However when they recorded tasks done with others they were spending more time on tasks of up to an hour. This shows that women obviously take more time on domestic chores whereas even though men are doing there bit the time taken is much shorter. By comparing all the diaries from males I could see that the tasks done by men were very similar such as changing a light bulb or fuse. This was also the case with women all the tasks done by them over the week was also very similar such as cooking, changing the linen etc. This shows me that there is a gender division when it comes to household tasks. The main role of a women's life is still to be that of a housewife, having dinner ready on the table, cleaning the house etc although men are doing there part in the domestic sphere but just not enough compared to men. This compares to the study of † Back to the future† by Madeline Leonard. She found that housework by large remains women's work, and this more than any other factor accounts for women's continued exploitation in the home. In her study she found that women are responsible for cooking, cleaning, washing and ironing, while men do jobs such as gardening and home maintenance. The key findings of all my primary research include that although it is true that women have made a huge progress, total equality in the home is still a myth. The battle of the sexes when it comes to domestic tasks has still not met its equilibrium although evidence from my research suggests that attitudes are changing slowly. EVALUATION & FINAL CONCLUSIONS. The sampling problems apparent in my research were that there were problems finding an equal number of working class and middle class couples. Consequently my sample was mainly working class. This problem simply reflected the facts of the type of domestic work that I the researcher was looking for. There may have been a need to adjust my hypothesis or the sample characteristics because it was too broad. My sample was reduced to ten couples because when I went round to respondent's homes they were not in. To overcome this problem I the researcher could have made the diary worth while for the respondents in order to motivate them to take part. I now believe that the sample I chose to use was not representative. This is because only ten couples took part. The couples in the survey were mainly working women and men and so may not be representative of professional men and women. There is no indication in the data that a range of different types of couples, e.g. working class, members of ethnic minorities, etc was sampled. The strengths of my research are that I focused on the comparative approach by using the snowballing method for example the way the couples were randomly sampled. The representatives of the sample, especially the equal sexes ratio. All diaries were handed out to respondents in their home because of the anonymity of the diaries. The weaknesses of my research were that the respondents might have thought the research was official and feel threatened by it, and so refuse to co-operate with it etc. Therefore the responses may not therefore reflect the truth, despite anonymity. The respondents were not supervised when they were filling in the diary and in reaction, some respondents may not have co-operated fully, experience of self reports tell us that people have a tendency to exaggerate, lie, not take surveys seriously. I did explore the issue in sufficient depth because my secondary data was appropriate to draw a suitable hypothesis. My secondary data was derived from a range of sources: social studies review, the Lancaster Regionalism Group etc. These all gave me an official picture of the domestic division of labour situation. The sources of data that I have collected are the most effective in relation to my aims. However other methods of data collection might have been possible for instance a large-scale survey of the population could be conducted of the workload shared between husband and wife in general. I could include questions on women's role as housewife which operationalise in various ways positive and negative attitudes towards them. Interviews could be conducted with husbands, which would measure their attitudes and their perception of social attitudes towards housewives. A content analysis could be carried out on newspaper coverage of the role of women in the home. My choice of method did affect my results for example by using the diary method I was able to control variables via using a snowballing sample. It is seen to have high reliability because it is easily repeated. Other sociologists can verify the data obtained by using the same standardised diary and similar samples. It is also seen as objective because the sample population is randomly rather than deliberately selected. During the diary schedule I did attempt to operationalise the concept domestic division of labour etc in such a way that it was not judgmental of the couples. I used my personal theoretical perspective and related this to my choice of method for instance the couples could have been interviewed together, although a more interesting variation that I chose was to use a diary method. This method was chosen so that they could record the amount of domestic tasks done separately. I was then able to compare data to get a gender version of the amount of tasks done. My experience of carrying out the research compares to the interpretivists. Firstly, the task of the researcher is to investigate how those taking part in the study interpret the world around them. In order to do this, the sociologist has to get inside their heads and see the world through their eyes. This is called â€Å"verstehen† and is an attempt to empathise with those being studied. Second, interpretivists emphasise validity seeing the world as it really is. Validity played a great importance in my chosen method because I was trying to find out how domestic tasks were shared so seeing the world as it really is. Third, cause and effect relationships are impossible to construct because people socially construct social situations and the interpretations people give to certain situations often vary. I found this to be the case in my research between couples. I do think my results are presented in the most effective way. As my chosen method was qualitative I was not able to produce any statistical data however my diaries were in columns with appropriate headings. To study this research further people could develop the idea of helping around the home by using Wilmot and young's assertion that the family is still symmetrical. Also people could research whether women actually want to be helped when it comes to household tasks even though feminists argue that the family is still an exploitative arrangement for women. CONCLUSION My hypothesis read†¦ † Men do help around the home but do not make an equal contribution† I can conclude that my hypothesis was correct because I found from my diaries that women are still doing more than there fair share of domestic work compared to men. This is the case because the extensions of traditional domestic roles of housewives and mothers are still in which women continue to be socialised these include serving and waiting on people, catering for them and cleaning and clearing up after others. These are all jobs women traditionally did and still do in the home. Such jobs include primary school teaching, low-grade catering work, working as shop assistants, supermarket shop fillers, secretaries' etc. For example secretaries often serve their (usually male bosses), organise the office in the workplace to make things easier for them, making tea and coffee and clearing up after their meetings. Primary school involves childminding, catering involves cooking etc. Women have limited career opportunities than males for a number of different reasons. There is the gender stereotyping at school and the wider gender role socialisation process in the home and in the work place. This is similar to the article † Back to the future† by Madeleine Leonard who found that this gender role socialisation process in the home made women continue to see housework as an important part of being a â€Å"good wife and mother† and are satisfied with the unequal domestic division of labour.

Facts About the Crystal Jelly

The crystal jelly (Aequorea victoria) has been called the most influential bioluminescent marine organism. This cnidarian possesses green fluorescent protein (GFP) and a photoprotein (or a protein that gives off light) called aequorin, both of which are used in laboratory, clinical and molecular research. Proteins from this sea jelly are also being studied for use in early detection of cancer. Description The aptly named crystal jelly is clear but may glow greenish-blue. Its bell may grow up to 10 inches in diameter. Classification Kingdom: AnimaliaPhylum: CnidariaClass: HydrozoaOrder: LeptothecataFamily: AequoreidaeGenus: AequoreaSpecies: victoria Habitat and Distribution The crystal jelly lives in pelagic waters in the Pacific Ocean from Vancouver, British Columbia, to central California. Feeding The crystal jelly eats copepods, and other planktonic creatures, comb jellies, and other jellyfish.