Prime Minister Essay Example | Topics and Well Written Essays - 1250 words

Prime Minister - Essay Example UK Prime Minister could be termed as 'dude with all the power' once he is elected2. Today, most of the constitutional monarchies are prime ministerial by nature and structure. It is alleged that the Prime Minister's office does not have much legal roots, but is open to speculation and calculation of historians and political scientists3. In recent years, perhaps the most accused Prime Minister as a dictator is Margaret Thatcher4. Not having properly written powers has not prevented the Prime Minister's office from being in control of most of the situations5. The nature of the Prime Minister's work is all-pervasive. He is the national leader, chief policy maker, Parliament leader, leader of the ruling party and the most powerful point in whole of United Kingdom and all information and power are at his disposal6. UK Prime Ministers are also charged of sometimes behaving like the United States President. The Prime Minister, even though appointed by the British Monarch, is bound by the constitutional convention and if happens to lose the majority in House of Commons, is bound to resign or request for a general election. To some extent, Prime Minister's office is still a de facto shade in it; it is governed more by custom than by the law of the land. British Monarch is bound by Prime Minister's advice and this gives the Prime Minister a more powerful position. He also can use certain royal prerogatives directly7. Even though Prime Ministers are never prevented from running the country in their own individual syle, the fact remains that the his position remains ambiguous as he is not empowered by any statutory authority, other than his position, usually, as the First Lord of the Treasury, which grants him his salary and the public accommodation. The office of the Prime Minister is more conventional than that of a rightful position from the Constitution. But during times of emergency, the office attains greater significance as demanded by the circumstances8. As the Prime Minister is entitled to 'create a Cabinet', a corrupt Prime Minister can take advantage of this situation and fill the posts with his own people, who would blindly support him under all circumstances. As the Monarch's Royal Prerogative is applied by Prime Minister's advice, he could give the monarch feedbacks and suggestions, which would eventually serve his purpose and misguide the Sovereign in matters of country and law. The 'face' of the Royal power, the Cabinet can be bought by the Prime Minister and the whole set of officials, cabinet ministers, and even the members of the Ruling Party could be in his favour, if he bribes and favours them. He has power over Privy Counsellors, Ambassadors, Civil Servants, High Commissioners, army, military officers, judges, Bishops and Archbishops of the Church of England. Almost all these posts are filled up with the Prime Minister's advice to the Sovereign and a corrupt Prime Minister can bring his own people, with the ultimate goa l of becoming a dictator. Even the peerages,

Essay for kirklands class Essay Example for Free

Essay for kirklands class Essay I believe that the state should not by itself have the power to declare war on another nation or country without the consent of the national government. the reason behind why I think this is because I believe that the government itself has enough power to keep the branches and there paper works in order and to do what is needed and expected of them to do nothing easel over that or under. I also believe that we south Carolinians if we do not like what north Korea is doing we should just stay out of it unless north Korea brings us into it and the reason I think this is because, us south Carolinians declaring war on north Korea just because we don’t like what they are doing is pretty stupid to me. I believe we are smart enough to figure it out without declaring war on a country or a nation. If south Carolina is having problems maintaining their drinking water supplies, and if the government has attempted numerous times to correct the problem, but has repeatedly failed, I believe that the government should problem get help form a nether government or help from whoever can fix this problem because we need water and without water we will die. I believe that the national government should beagle to take action because it is a life or death situation so yes I think that the government of South Carolina also known as the local government should be able to get help from the national government and take the measures needed to fix this problem. I believe that the local government should try to figure it out before getting help from the national government, and if the national government can’t fix it then I think that the national government should beagle to ask another government for help to fix this life or death situation. But if they need to shut down the factory then they should do it because if the south Carolinians don’t have any water they could die and they need water because water was made to keep us alive just like food was made to keep us alive without water you can’t take a shower either and so everyone would stink. If the local chemical factory is causing this problem then they need to shut the chemical  factory down and move it to a different area so it can’t cause anymore problems to our water systems and we would need to move it to a place where it can’t contaminate anything that could herm us or bother us like were its not close to a farm food supplies or water supplies.

Substrate On Rate Respiration In Saccharomyces Cerevisiae

Substrate On Rate Respiration In Saccharomyces Cerevisiae The aim of this investigation is to examine what effects different substrates have on the respiration of yeast. I will investigate this by measuring the amount of carbon dioxide evolved during anaerobic respiration. The volume of CO2 gas will be collected using a gas syringe. BACKGROUND INFORMATION YEAST Saccharomyces cerevisiae, also known as yeast, is a micro organism that uses saprophytic digestion to break down substrates. This is achieved through releasing specific enzymes to break down specific substrates, but if yeast does not contain a certain types of enzyme then it cannot break down its substrate. The more the enzyme of a particular substrate, the faster the rate of breakdown and therefore the more CO2 is produced. This will help me to test how much CO2 each substrate produces. Yeast can also respire aerobically and anerobically depending on the availability of O2. If there is plentiful of O2 then yeast would respire aerobically with sugars, producing H2O and CO2 as waste products. However, if no oxygen is available then the fermentation would occur which converts sugars into CO2 and ethanol. RESPIRATION Respiration is the process by which energy is released energy from glucose in the presence of Oxygen, forming carbon dioxide and water as waste products. Glucose releases energy in a series of reactions that take place inside components of the cell. The stages are briefly explained below: GLYCOLYSIS To get the sugar in a more reactive form it is produced to fructose-1,6-bisphosphate by the addition 2 phosphate molecules. This process is a phosphorylation reaction. The fructose-1,6-bisphosphate is then broken down into 2 molecules of glyceraldehydes-3-phosphate, which comprises of 3C each. The glyceraldehydes-3-phosphate converted into pyruvate via the oxidation process where each GAL3P molecule releases 2 hydrogen ions and 2 electrons. The electrons are then transferred to NAD to produce NADH (reduced NAD) and the energy is used to produce 4ATP from 4ADP and 4Pi. Finally there is a net yield of 2 molecules of ATP, and 2 molecules of pyruvate which is used in the link reaction and 2 molecules of reduced NAD which carries on to the link reaction. LINK REACTION In the link reaction the 2 molecules of pyruvate leave the cytoplasm of the cell and enter the mitochondrial matrix. This is an oxidation reaction where 2 NAD molecules oxidise 2 pyruvate molecules into 2 acid molecules. These 2 molecules of acetic acid then go on to combine with 2 coenzyme-A molecules to form Acetyl Co enzyme A. in the end of this stage 2 molecules of reduced NAD form, 2 molecules of CO2 is lost and most importantly, Acetyl Co enzyme A is formed through the conversion of pyruvate. This is then used in the next stage of respiration. KREBS CYCLE At the start Acetyl Coenzyme A , combines with Citrate Synthase an enzyme as well and a 4 carbon molecule called oxaloacetate, forming Citrate. Then, Citrate goes through the process of oxidative decarboxylation which forms a 5 carbon molecule called oxoglutarate.at this point NADH is produced and CO2 is removed. In the latter stages of the krebs cycle, the oxoglutarate is changed into a 4 carbon oxaloacetate molecule. NADH is made and 1 molecule ATP is also made. The volume of CO2 that is produced in the krebs cycle is important as this is the dependant variable. ELECTRON TRANSPORT CHAIN In this stage all of the NADH and FADH that has been produced in the previous stages is converted into ATP. This takes place in the cristae of the mitochondria. The NADH and FADH electrons move. When the electrons pass from one carrier to another, a series of reduction and oxidation reactions take place which releases energy in the process. This energy is used to pump H+ ions from the matrix into the intermembrane space, thus creating a gradient where the concentration of the H+ ions in the intermembranal space is higher than it s in the matrix. The inner membrane contains enzymes called ATP Synthase and The H+ ions diffuse through these enzymes causing energy to be released which is used to synthesise ATP through phosphorylation. The process is called because the final terminal electron acceptor is oxygen which picks up the electrons from the chain and the H+ ion from the matrix to form H20 as a waste product. This reaction is catalysed by the enzyme Cytochrome Oxidase For every NADH which enters the chain and is oxidised by NADH dehydrogenase, 3 ATP are produced. For each FADH that enters the chain, 2 molecules of ATP are made. ENZYMES Enzymes are proteins that can effectively increase the rate of a reaction by lowering the required energy (activation energy) needed in order for the reaction to occur. Enzymes have a tertiary structure which decides the shape of the active site. The substrate must be specific to the active site because if they were not complementary to each other, then the substrate can no longer bind to the active site, thus the enzyme substrate complex does not form. The performance of enzymes can be affected in several ways some of which I have explained below. TEMPERATURE An increase in temperature will cause an increase in the rate of reaction because both the enzyme particles and substrate particles have gained kinetic energy. This will result in the particles to move faster, thus increasing collision frequency and the numbers of successful collisions as the particles have the required activation energy. If the temperature rises above the optimum temperature then the enzymes can become denatured. This happens because the enzyme molecule vibrates more causing the weak hydrogen bonds (holding the 3D structure of the enzyme together) to break. This eventually leads to the shape of the active site being altered. Consequently, the substrate will not be able to bind with the substrate as the shape of the active site is no longer complementary so the substrate enzyme complex can not form. This is important in my experiment because if the yeast (enzyme) was to become denatured then it would not be able to bind with the substrate (e.g. glucose) and the react ion would not be catalysed, preventing any CO2 from being formed. I must ensure that temperature is kept constant throughout. PH Another factor which can affect enzymes is pH. Enzymes also have an optimum pH which is pH enzymes work best at. Changing the pH can change the tertiary structure due to the number of H+ ion in an acid or the OH- ions in an alkali. These ions disrupt the hydrogen and ionic bonds between -NH2 and -COOH. This will cause the tertiary structure to break down and changing the active site in the process. Once again, the substrate will no longer be able to bind with the active site, hence no substrate enzyme complex will form. I intend to use a buffer solution which will resist any changes in pH. SUBSTRATE CONCENTRATION Increasing substrate concentration increases enzyme activity as they are more molecules to occupy the active site, thus a faster reaction. If more enzyme substrate complex forms then more CO2 will be produced. However this is occurs only for a certain period until all the active sites are saturated with substrates. Therefore an increase in substrate concentration will not result in a increase in the rate of reaction. PLANNING THE DEPENDANT AND INDEPENDENT VARIABLE The dependant variable will be the volume of C02 produced during respiration and the independent variable will be the substrates that I decide to use in the experiment. These are Glucose, Fructose, Maltose, Lactose and Sucrose. NULL HYPOTHESIS The substrates will have no effect on the volume of CO2 produced during the respiration of yeast. HYPOTHESIS As the substrates are changed, the volume of CO2 formed during the respiration of yeast will also change PREDICTION I predict that of all my substrates, maltose will produce the greatest volume of CO2 when added to yeast in a fixed amount of time. Referring to my background knowledge, I know that glucose and fructose monosaccharides which can be directly absorbed by the yeast as no enzymes are required to break them down. This will allow for glycolysis to take place quicker. However I think that glucose will produce CO2 quicker than fructose because glucose is the main food source/ respiratory substrate for yeast, thus there will more glucose carrier proteins present in yeast. If more carriers are present then will enable absorption to occur quicker, hence respiration will happen quicker. So I believe glucose will produce more CO2 than fructose within a given time period. However in terms of volume of C02, I believe maltose will exceed both of these monosaccharides. Maltose is a disaccharide that consists of two glucose molecules held together by a glycosidic bond. Once this bond is broken down by maltase, there will be twice as many glucose molecules available in the same volume of other substrates such as glucose. More sugars can then be provided for respiration, hence more CO2 produced in 45 minutes. One point that must be taken into to account is that maltose cant be used directly, so it could take time before the glucose can be used. In addition, as glucose is a polar molecule it must be transported via facilitated diffusion. This could be a limiting factor if all the carriers become occupied, which would slow down the respiration process as a result. After fructose, I predict sucrose will be the 4th substrate to produce the most CO2. Sucrose is also a disaccharide which consists of a glucose and fructose molecule. This substrate also requires enzymes to break it down and this could be a time consuming process as there is a limited amount of time. Furthermore, there arent as many fructose carrier proteins present in yeast cell membrane compared to glucose. Finally I predict lactose will produce the least amount of CO2 purely because yeast doesnt contain the enzyme lactase to digest lactose. This means that its monomers galactose and glucose cannot be used in respiration, thus no CO2 will be produced as a by-product. APPARATUS The following apparatus will be used when conducting the experiment: Clamp and stand Gas syringe accurate to 0.5cm ³/mol Water bath heated to 400C Dry Yeast Thermometer Boiling tubes Safety goggles Universal indicator Distilled water Buffer solution (slightly acidic) Substrates Electronic weighing balance (2 d.p) Stop watch Rubber bung and rubber tube Pipette (15cm3) funnel Measuring cylinders ( 250cm3) Stirring rod Conical Flask Beakers ( 250cm3, 20cm3) METHOD OF INVESTIGATION Steps Accuracy Reason for method 1. Clean all the apparatus used to contain sugars or yeast using distilled water. Set up water bath at a temperature of 40 °C. N/A Cleaning with distilled water ensures that all the equipment to be used in the experiment is clean and is free from impurities that could possibly interfere with CO2 collection.The water bath will be set to 400C because this is the temperature that I have decided to use in my experiments. 2. Fill up a 1 litre beaker precisely up to the 1litre mark with distilled water. Then add a buffer tablet into the beaker and stir thoroughly with a stirring rod Make sure the distilled water has been filled up exactly to the 1L mark. This is the step on how to produce a buffer solution. A buffer solution is required as it dissolves the yeast and substrate together. Allowing collision of the yeast and the substrate is vital otherwise a reaction would not occur 3. Weigh 30g of dry yeast using an electronic balance and transfer it into a beaker. The scale will be accurate to 2 d.p. to allow consistency. If a solution contains more yeast, then more collisions may be involved between the enzymes and substrate, hence a greater rate of respiration, and more CO2 being produced than there should be. 30g of yeast will provide a stock solution for all 15 experiments, thus each experiment will use 2g of yeast. Excess yeast cells in the solution, will cause a large volume of CO2 production as more respiration will occur so 2g is a suitable amount. Keeping a constant concentration of yeast will ensure that my test is fair because an increase in yeast concentration will increase the amount of cells respiring therefore the volume of CO2 will increase 4. Place 250cm3 of buffer solution into a 300cm3 beaker containing dry yeast. Stir thoroughly Ensure that the volume is read from the bottom of the meniscus level. The volume must be read at eye level I have decided to use a bulk buffer solution because it keeps the concentration of yeast constant. Errors are more likely to occur if I had to weigh 2g of yeast and 15cm3 of buffer solution before each experiment. I have also taken into account of any spillages that may occur so I have ensured that I have prepared more than the required amount. 5. Accurately weigh the amount of substrate needed using the electronic balance and place into a 20cm3 beaker. Then, using a pipette, collect 15cm3 of buffer solution into a measuring cylinder and add it to the substrate beaker. The solution should be stirred and the beaker should then be placed in the water bath. Before using the balance confirm that it has been adjusted to 0. The measuring cylinder will be accurate to 0.1cm3. Again, ensure that the reading is taken from the bottom of the meniscus and at eye level. I must weigh the correct amount of substrate so that the concentration remains constant throughout the experiment (1M) 6. I will Prepare the conical flasks and attach the rubber tubing (connected to the rubber bung) to the gas syringe. I will carefully measure 15cm3 of yeast solution with the aid of a pipette and transfer it into a conical flask. This will then be stirred thoroughly and placed back into the water bath. Pipette is accurate to 0.5cm3. The yeast has to be measured very accurately otherwise this would affect my results. For example if too much yeast is added, then there would be increase in amount of enzymes available and so there would be increase in successful collisions resulting in a faster rate of reaction with more CO2 being produced per unit time. The solution has to be agitated to ensure that the yeast molecules are evenly spread and do not settle to the bottom of the boiling tube so that the chances of collisions increases. The water bath will maintain the temperature of the yeast solution. This will prevent the enzymes from being affected by a change in temperature. 7. Use a thermometer to measure the temperature of both the water bath and yeast solution to ensure they are both 400C. As soon as the substrate is poured into the conical flask containing the yeast, immediately attach the bung onto the flask. This should be followed by timing using the stop watch. The stop watch is accurate to 0.01seconds. I have considered the difficulty faced when applying the rubber bung and starting the stop watch. I must make sure that I start the stop watch as soon as the bung is placed in postion and I intend to keep this the same for my other experiments. A rubber bung and the rubber tube will be attached instantly as respiration can occur immediately. The CO2 produced will be collected in the gas syringe. It is important that does not escape. if this did happen then a smaller volume of CO2 would be collected by the syringe, thus the results obtained would not be precise.The stop clock will need to be started immediately to ensure all the experiments go on for exactly the same amount of time, if one experiment was to go on for longer more CO2 would be produced and thus I would get anomalies in my results. To avoid this, the clock needs to be started as soon as the experiment begins. 8. Take readings after 5 minutes of the co2 collected into the gas syringe with the aid of a stop watch. This step should be repeated until the 45th minute for each experiment. The temperature of the solution must also be taken, which should remain constant at 400C. The readings must be taken straight after each interval. For example, I would take the reading just before the 5th minute interval. The Stop watch is accurate to 0.01seconds. The purpose of this step is to observe how much CO2 each substrate produces as time passes. 9. Using a universal indicator I will measure the PH after testing each substrate. The PH should constant throughout but if not, then it should still be recorded. The beakers, conical flask and measuring cylinders should be rinsed with distilled water after each experiment NA It is important to control PH as it could affect the amount of CO2. I will talk about this in greater detail in controlled variables. Rinsing removes any residue that may have been left over in the equipment CONTROLLED VARIABLES Controlled Variable How I will control it Why I will control it Temperature This variable will be controlled using a water bath which will be set to 40 °C throughout the experiment. The temperature must be controlled because the temperature will affect the rate of respiration of the yeast. If the temperature is changed, for example, too high then this may denature the enzymes used by yeast to digest substrates. pH The purpose of a buffer solution is to resist any changes in pH, therefore I will control the pH by add the yeast and substrate to a buffer solution. When CO2 is released, it would dissociate, forming hydrogen ions and hydrogen carbonate. These will cause the pH to decrease and become more acidic. A decrease in pH would affect enzyme activity as this disrupts the charges (H+ and OH-) on the enzymes. This will result in changes in the ionic and hydrogen bonds holding the enzyme together. The enzyme would denature, thus the substrate will no longer fit and so an enzyme-substrate complex will not form. Concentration of yeast used I will prepare stock solution of yeast (30g) containing 250cm3 of buffer solution. This variable can be controlled by simply keeping the amount of yeast (15cm3) used constant throughout the experiments. A stock solution will automatically eliminate any changes to the concentration of yeast since I will be taking the same amount of yeast from the same solution so it will always remain the same. Maintaining the concentration ensures that the same surface area is exposed by the yeast over which enzymes are released for extra cellular digestion to take place. Concentration of the substrate 15cm3 of a 1M substrate solution will be used constantly. If more substrate is added then more C02 would be produced. This is because there is more substrate available for the yeast to digest for respiration, hence producing larger volumes of C02 than it should. If this variable is not controlled then it I would not be able to determine if an increase in CO2 is due to the type of substrate increase in concentration. Timing I will time the experiment using a stop watch in all of my experiments. I will constantly time the experiment for a total of 45 minutes, ensuring that the reading is taken immediately after each 5 minute interval. I have to control this factor because if the yeast is left in the substrate for a longer time period for one experiment then this will allow more respiration to occur. The yeast will digest the substrate to produce more CO2 so therefore all solutions must be left to respire for exactly the same amount of time in order to obtain reliable results. Culture of yeast Use the same brand of yeast in all experiments. Different types of yeast may cause different results as the number of carrier proteins may vary for a particular substrate. Using the same yeast will ensure that the size of the yeast in each experiment remains the same. CALCULATING SUBSTRATE CONCENTRATION In order to keep the substrate concentration the same I will have to calculate the mass of each of my substrates. Firstly, I will use the following equation: Moles = Molarity x Volume 1000 The substrate concentration I will be using will be 0.5M and the volume will be 25cm3. In order to determine the mass from the number of moles I shall then use: Mass = Moles x Mr CALCULATIONS FOR GLUCOSE AND FRUCTOSE 1000 0.5 X 25 = 0.0125mol Fructose and Glucose has the same Mr of 180 0.0125 X 180 = 2.25g I need add 2.25 of each substrate into 25cm3 of buffer solution. I will produce a stock solution which will help maintain the concentration of the substrates throughout. I will be carrying out 2 experiments for Glucose or Fructose so I will need 4.5g of each (2 X 2.25 = 4.5g). CALCULATION FOR MALTOSE, SUCROSE AND LACTOSE 10000.5 X 25 = 0.0125mol Maltose, Sucrose and Lactose have the same Mr of 342 Maltose, Sucrose and Lactose are isomers consisting of two monosaccharides linked together by a glycosidic bond. I have taken into account that when a condensation recaction occurs to form this disaccharide then a water molecule is removed so I must substract the Mr of a water molecule from the Mr of the disaccharide. 360-18= 342 0.0125 X 342 = 4.28g So I will add 4.28g of Maltose, Sucrose and Lactose with 25cm3 of buffer solution. I will also produce a stock solution which will allow me to carry out the required amount of experiments. Therefore, I need to measure 8.56g (2 X 4.28g = 8.56g) of each substrate which will then be dissolved into buffer solution. CONTROLLED EXPERIMENTS I have decided to carry out 6 controlled experiments for each of the 5 substrate in conjunction with the normal experiments. I will conduct these experiments in order to demonstrate and prove that the process of respiration cannot occur without the presence of the respiratory substrate as well as the yeast. The first experiment will involving a boiling tube containing only the 25cm3 of yeast solution. After placing the boiling tube in the water bath (400C), I will then record how much CO2 is produced. This would be conducted in the same way as my method where I would take readings after every 5 minutes until the 45th minute has been reached. The other 5 control experiments will only consist of the substrates. I will measure 15cm3 of each substrate into separate boiling tubes. These will also be placed in a water bath and the volume of CO2 produced will be recorded at every 5 minute intervals for 45 minutes. No CO2 being produced will confirm that the yeast cannot produce CO2 with the presence of a substrate and a substrate cannot respire on its own. DATA ANALYSIS Below is an exemplar table which will be used to analyse the results produced in the experiment This table will help me to calculate the average of the CO2 produced in each of the experiments after every 5 minutes. I will produce line graphs using the averages of CO2, which will enable me to compare the averages of the different substrates. From this, I can determine if digestion for polysaccharides and disaccharides effects how much CO2 is produced. This is how I will present the average of CO2 production for each substrate: Graph showing the volume of CO2 produced against the time taken Average CO2 Production (cm3) Time (mins) A t- test is a statistical test that takes a look the amount of data, if there is a difference between the means of two sets of data and also the spread of the data. A t-test is relevant as I will be using a large sample of results which will consist of results from other members in m class and including mine. The formula for the t-test is: I have decided to construct a histogram for each substrate as this will allow me to compare my data easily after plotting frequency against experiments. A histogram will show if there any significant overlap between two substrates. Consequently, this can help me to make a decision of whether or not a t-test must be carried out. The below histogram would require a t-test: Glucose Maltose MODIFICATIONS I will use an inverted burette for measuring the volume of CO2 produced instead of a gas syringe. When carrying out my preliminary experiments I found that the gas syringe didnt move smoothly, therefore i was unable to accurately read how much CO2 was being produced. Therefore I will use an inverted burette which has an inaccuracy of 0.1cm3 Unfortunately, no buffer solution is available to control the pH of solution. In order to confirm that the pH hasnt changed, I will measure the pH at the start and end of each experiment. This will achieved using a universal indicator. I have changed the point at which I will take the reading. Initially I chose to take a reading jus before swirling the flask but I have now realised that this is incorrect. It would be wrong to do it this way because I want all the CO2 to escape from the flask before each reading is taken. So I will now take reading after swirling the conical flask.

Walmart ecommerce ops Essay examples -- essays research papers

What is Wal-Mart dong that seems to fit a definition of â€Å"successful† e-commerce operations? What cold they do better? How does shopping on-line compare to your experience looking for a similar type of item at a bricks-and-mortar store? How does this site compare to other experiences you’ve had with e-commerce   Ã‚  Ã‚  Ã‚  Ã‚  When you talk about Wal-Mart the first thing that you have to remember is that they are the largest retailer in the world. Wal-Mart employs more people in the United States than any other company and is second only to the federal government in the number of employees that they have on the payroll. These are important facts to consider in that due to their tremendous size, Wal-Mart has an enormous effect on the economy and the way that business is conducted. In many instances, if a company wants to continue to do business they have to either follow what Wal-Mart is doing or attempt to compete against Wal-Mart in some other fashion. It is not unreasonable to state that Wal-Mart is the reason why many businesses are in business today. They were forced out by the sheer size of Wal-Mart.   Ã‚  Ã‚  Ã‚  Ã‚  So, with this in mind it is interesting to note that Wal-Mart ranks only third on the e-commerce scale behind Dell computers and Amazon. (Sullivan 2004) What is the reason for this? It’s hard to say and point to one specific reason why Wal-Mart doesn’t lead this list but maybe looking at the criteria outlined in the background reading will help to answer this question. (Wollan 2003)   Ã‚  Ã‚  Ã‚  Ã‚  In the background reading a list of criteria is given that outlines the advantages of e-commerce as it relates to operations management. The companies that are able to capitalize on these are the ones that will be successful. Wal-Mart is able to capitalize and continues to do so as it improves and expands into the e-commerce environment. Some of these advantages are: †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Better availability of service †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Cost reduction in information processing †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Better of timeliness of service †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Better access to customer markets †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Initial cost of operations less expensive †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Operating costs of operations less expensive †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Bet... ...Wal-Mart provides not only a Boolean search box but also some â€Å"pretty† tabs labeled with general names such as toys and electronics. But this is not special and is in fact pretty much the norm for companies that do business online. In other words, the Walmart.com website does not stand out from the crowd. As a matter of fact if you compare the Amazon.com websites to Walmart.com they look very similar. (Amazon 2005) I found the Dell website to be less friendly and almost irritating with the addition of pop-up ads that I had to close. (Dell, 2005) REFERENCES Amazon (2005) [Company web-site]. Retrieved June 19, 2005 from http://www.amazon.com/exec/obidos/subst/home/home.html/103-3903465-0764615 Dell Computers, (2005) [Company web-site]. Retrieved June 19, 2005 from http://www.dell.com/ Sullivan, Laurie. (2004, November, 8). E-Commerce: Promise Fulfilled. InformationWeek, 1013(3), 70. Wal-Mart. (2005). [Company web-site]. Retrieved on February 21, 2005, from http://www.walmart.com Wollan, M. L. (2003). E-commerce operations management. PowerPoint presentation for OPM 500, Module 5. Zimmerman, A. (2003, Nov. 21). To sell goods to Wal-Mart, get on the net. Wall Street Journal, B.1.

Peter Stark Essay

Summary of Stark’s article Peter Stark’s article As Freezing Persons Recollect The Snow—First Chill—Then Stupor—Then The Letting go: the cold hard facts of freezing to death talks and explains what happens to the human body when a person is freezing to death but it also gives an enjoyable story for the reader. The character in this story is in his way to a friend’s house for dinner and night cross country ski when his jeep slides off the road and gets stuck in a snow bank. Stark made it clear that his character was not panicked at first but just simply worried about missing the dinner with his friends. Not wanting to miss his plans the character puts his skis on, looks at the map, and heads to the cabin on top of the hill. While this story is unfolding Stark includes scientific data about the lowest core temperature a human can have before perishing. The character wants to save time by going up the steep hill instead of following the road that has many switch backs this is wh en everything starts to go wrong. The character goes for about an hour with no sign of the road, while assessing the map he hears a metallic pop and a piece of his binding has popped out. The character is trying to find the piece of his binding and while he does this his body temperature begins to lower after finding the piece his core temperature has lowered a substantial amount. The character has now started to panic and decides to go back to the jeep and its warmth on his way down he falls and lands pretty hard and he is feeling very tired so decides to rest. The rest of the story goes on with him losing and gaining conciseness but his body is too weak to get up and move on and more data about core temperatures and hypothermia. The friends find the character in the snow half naked but he isn’t dead he has a faint heart beat so they take him to the hospital and the doctor brings up his core temperature. The character survives. Stark, Peter.â€Å"As Freezing Persons Recollect The Snow—First Chill†”Then Stupor—Then The Letting go: the cold hard facts of freezing to death†. Outside magazine. Outside online. January 1997.web 26.aug. 2010

abu essays

abu essays INTERNET REGULATION: POLICING CYBERSPACE The Internet is a method of communication and a source of information that is becoming more popular among those who are interested in, and have the time to surf the information superhighway. The problem with this much information being accessible to this many people is that some of it is deemed inappropriate for minors. The government wants censorship, but a segment of the population does not. Legislative regulation of the Internet would be an appropriate function The Communications Decency Act is an amendment which prevents the information superhighway from becoming a computer "red light district." On June 14, 1995, by a vote of 84-16, the United States Senate passed the amendment. It is now being brought through the House of Representatives.1 The Internet is owned and operated by the government, which gives them the obligation to restrict the materials available through it. Though it appears to have sprung up overnight, the inspiration of free-spirited hackers, it in fact was born in Defense Department Cold War projects of the 1950s.2 The United States Government owns the Internet and has the responsibility to determine who uses it and how it The government must control what information is This material is not lawfully available through the mail or over the telephone, there is no valid reason these perverts should be allowed unimpeded on the Internet. Since our initiative, the industry has commendably advanced some blocking devices, but they are not a substitute for Because the Internet has become one of the biggest sources of information in this world, legislative safeguards are The government gives citizens the privilege of using the Internet, but it has never given them the right to use They seem to rationalize that the framers of the constitution planned make certain that above all else...

SummaryCritique essays

SummaryCritique essays #___________ COURSE#_______ SECTION/TIME______ REFERENCE: Darley, J. M., , B. (1968). Bystander intervention in emergencies: Diffusion of responsibility in R. Hock (Ed.), Forty Studies That Changed Psychology (295-303). Upper Saddle, N. J.: Prentice Hall. SUMMARY: Society dictates that we take action to help others in emergency situations, but often, we do not. In the famous case of Genovese, where 38 bystanders watched a woman get brutally murdered, only one person called the police. Darley and Latane analyzed the bystanders reactions. They believed that the reason no one took steps to help Kitty Genovese was a phenomena they called diffusion of responsibility. As the number of bystanders in an emergency increases, the greater the belief that someone else will help. With 3 different groups of subjects, Darley and Latane measured the percentage of subjects in each condition who helped the alleged troubled student. They also measured the amount of time it took them to respond. After four minutes, the experiment was terminated. Their findings supported their hypothesis as the amount of delay in helping was greater when more by-standers were present. They also considered the role of social influence in the study. What was it a bout the presence of others that was so influential? Beyond their specific findings, Darley and Latanes ground-breaking research on helping behavior and diffusion of responsibility, continues to influence many studies on very topical issues. CRITIQUE: Darley and Latane contributed greatly to explaining a perplexing human behavior. Hopefully, as more people learn about the bystander effect, they will become aware of the need to act in any emergency situation, even if others are present. Research has demonstrated that when people have learned about the bystander effect, their participation level is higher in emerge ...

How to Earn an Online High School Diploma as an Adult

How to Earn an Online High School Diploma as an Adult Adults who didnt graduate high school realize that getting a high school diploma can improve their employment prospects and make them eligible for workplace promotions. But most don’t have the leisure of spending seven hours a day on a school campus. Online high school diploma programs offer adults the chance to schedule school work at their convenience and complete courses at their own pace. Why Degrees Are Important Before enrolling in an adult online high school diploma program, think about your needs. Completing a high school diploma can give bring personal satisfaction and can make you more competitive for some jobs. You may need a high school diploma to join the military or be hired at some entry-level jobs. And there are other options for adult education. If you have the skills and are willing to spend a couple of years in class, you may be able to go straight to a community college and complete an associate’s degree. This may be the best choice for advanced students who plan on attending college anyway. Alternatively, you may decide to take an exam and earn a GED. This choice appeals to students who have several years of remaining high school credits and would prefer a quick fix. Make sure to weigh all your options before you make a choice. Online School With Adult Programs If you decide that earning an online diploma is the best choice, the next step is to choose an online high school program. Make sure the school you select is accredited by the proper organization. Schools that are regionally accredited are the most widely accepted by employers and colleges. Many employers and colleges also accept credits from schools accredited by the Distance Education Training Council. However, a diploma from these schools will not be as commonly accepted. Make a list of questions to ask each online high school you consider. Find out: Whether the high school has an accelerated program for adults.Whether it provides support for students who need help.How much work you will need to complete. Tuition and Financial Aid If you are in your late teens or early 20s, you may qualify to finish your education at an online charter high school for free (depending on your state law.) Otherwise, you will need to pay for your classes. Ask the online high school you select whether there are any tuition assistance or financial aid programs. Many online high schools offer adult students a tuition payment program that allows payments to be spread out over a semester instead of a lump sum due at the beginning of classes. If tuition is still too steep, you may be able to qualify for an educational loan. Talk to your school and your bank. Complete the Required Courses Finishing your online high school courses may take several years or just a few weeks. As an adult, it can be difficult to manage school responsibilities in addition to a busy life. But know that your sacrifices will be worth it. Once you’ve earned your online high school diploma, take the time to celebrate. Hang your new diploma on the wall. You now qualify for a greater number of jobs and are eligible for more workplace promotions. Plus, you have the personal satisfaction of knowing you completed a worthwhile goal.

Current event on macroeconomics Article Example | Topics and Well Written Essays - 500 words

Current event on macroeconomics - Article Example The article indicates that in 2013, North Carolina was the only state in US where the jobless were not provided with the extended benefits yet the state registered had one on the largest improvements in market performance as well as economic growth (John 16). US Bureau of Labor indicated that in the second half of 2013, the payroll jobs in North Carolina rose by 1.5% compared with 0.8% rise in jobs opportunities nationally. Similarly, the unemployment rate in the state dropped by 17% while the nationally it dropped by 12%. Despite the dropping labor force in North Carolina in 2013, it started to rise again in the first quarter of 2014. This article indicates that from June 2013 up to June 2014, North Carolina employment population ratio increased three times more than that of national average. Thus, it is an indication that by ending the extended benefits program, it led to job creation as well as job acceptance. Notable macroeconomic concepts that are covered by the article include unemployment and extended benefits programs. Extended benefits entail the payments that are available to employees who have exhausted regular employment insurance benefits. During the periods of high unemployment, the states provides weeks of benefits, a vital economic strategy that aims increasing the consumers purchasing power as well as the aggregate demand. After passing the American Taxpayer Relief Act of 2012 and the signing by the President, the deadlines for the Emergency Unemployment Compensation were extended to December 2013. However, the act did not affect the number of weeks of benefits available under the Emergency Unemployment Compensation. According to the Department of labor, the federal government budgets reduction referred to as sequestration may affect the resident’s unemployment insurance benefits in the week ending October 6th. The government has directed the Department of labor to re duce by 7.2% the payments of individuals who are receiving the

Abandoned vehicle problem evidences Assignment Example | Topics and Well Written Essays - 750 words

Abandoned vehicle problem evidences - Assignment Example An abandoned vehicle can be plainly defined as a vehicle gone unattended, left parked with no information about the owner and further parked within an area of 10 feet or more or less the same, for a time period of 48 hours and in the publicly used or mostly in the privately owned area for around 30 days, without the permission or consent of the zone owner (Alaska Department of Administration, 2011). Some of the most common reasons of the car abandoning are as follows: Most of the cars abandoned in Jeddah are by the expats who do not find enough time to dispose of their cars and travel back to their native lands without going through the hassle of disposing off their vehicles. Some abandoned vehicles, that as in fulfill the above definition of vehicle abandoning i.e., stay parked at airports or other areas for a period of 30 days are actually left or parked by expats until their return from vacations from their native lands. Majority of these cars are old and derelict for a safe daily based use and parked as useless by the owner after they have removed all the proves of their ownership. Another big part of these abandoned cars come from both the local residents and expats who flee away from holding any accountability to the money owed for the cars, most of which comprise of luxurious sports cars. Some abandoned cars are highly under car loan defaults and the owners look for sneak away by parking the cars as unrecognized. Because of the above reasons and further many not identified properly, the car abandoning has turned into one of the biggest reportable issues of The Kingdom of Saudi Arabia, specifically in Birman and Jeddah. According to reports, Law enforcement officers have been into devastating nightmares dealing with the abandoned vehicles that have apparently been aggressively multiplying over the time. The major threats and environmental nuisance these abandoned vehicles are posing is rising alarmingly. They are taking up unwanted space and creating a se nse of insecurity amongst the normal residents as the long parked cars give a secure pathway for crimes (Historic Vehicle, 2012). Another big issue related to the vehicle abandoning is that they, if seen from a financial perspective are a big block towards making the cash liquid. Liquid cash is very important for the refining and uplifting of economic standards and the Kingdom of Saudi Arabia is amongst the strongest Arab economies. Their strength is most looked after for the viable working of the Arab and most importantly the economy of all the Muslim countries. A block of average 7200 vehicles per month is a bid hindrance to the smooth working of their economic system. The reinforcement authorities have actively involved Department of Specialized Hygiene of the Waste Department of Municipality to draft out feasible and practical strategies to work over the abandoned vehicles. Now, these abandoned cars are left at wait for the owner’s contact for maximum six months. During t his time, efforts are made to trace the owner and the vehicle is also printed in newspaper for any whereabouts of the owner. If the owner gets traced, he is levied with a penalty and warned to dispose of the vehicle officially or otherwise keep the vehicle and clear off the claims that the vehicle holds. Regular checks are made about the outstanding vehicle schedules that had prompted the owner to attempt silent abandoning (Seatlle, 2013). If the owner is found to have

Edinburgh Napier University aspires to be 'environmentally friendly' Essay

Edinburgh Napier University aspires to be 'environmentally friendly' and 'sustainable'. Write a report for the Principal - Essay Example Write a report for the Principal describing what would be entailed in achieving this objective including an appraisal of the costs and the benefits Definition of sustainability Sustainability generally refers to the capacity to endure, to maintain and endure. Within the context of UK higher education, sustainability includes various aspects, including research studies on sustainability, the process of sustaining the university, and universities of sustainability. In Britain, funding is tapped by authorizing research related to environmental studies and climate change. The opening and offering of master’s courses considering the environmental angle on specific disciplines on environmental economics as well as climate modelling also make up part of the general elements making up sustainability in UK universities. The process of sustaining the university includes the designation of energy-reduction leaders in the school. Their focus would be on decreasing the negative impact and environmental impact of school activities; a focus on reducing carbon and energy bills is also crucial to ensuring sustainability in universities. The role of the university in sustaining the local environment is also important, and this includes the emissions produced by students through their travel activities. For universities of sustainability, the highlight of the education in the universities focuses on teaching environmental responsibility to the students, on fixing the curriculum in order to guarantee that the courses being offered also include the instruction of new skills and information which can impact on climate change and environmental sustainability. Themes included in this university sustainability are important if the university discussions in consideration of sustainability are more than lip-service commitments. Trans-disciplinarity and fluidity of sustainability discussions are part of these themes. The importance of trans-disciplinarity is highlighted in relation to sustainability, with the assistance and coordinated activities of university resources and environmental agencies. System of environmental sustainability In order to achieve environmental sustainability in the Edinburgh Napier University, there is a need to implement important changes in the university courses and curricula. The Sustainability Tracking Assessment & Rating System, also known as STARS can be applied to the university in order to determine and measure its environmental sustainability (AASHE, 2013a). This is a transparent and self-reporting system designed for colleges and universities in order to evaluate sustainability performance. This system was established by the American- based, Association for the Advancement of Sustainability in Higher Education (AASHE) which is considered the international leader in the development of sustainability measures, promoting strong participation from various representatives in higher education. This system seeks to establish a st andard in establishing sustainability in different elements of higher education. It also seeks to provide

Free File Sharing Essay Example | Topics and Well Written Essays - 750 words - 1

Free File Sharing - Essay Example In this light, all parties involved in the sharing tend to believe that the internet is a free place for them to give away file to their friends and other interested parties. This occurs especially with the new technologies that are coming up, such as peer-to-peer file sharing and other sites. With such events transpiring, some unscrupulous file owners tend to sell the said files for a profit that they get to spend and rip off the original owners of their dues, both in terms of moral support and financially (Biron). This is tantamount to physical and practical theft, which on a moral scale, and according to social norms, is wrong. In addition, morally, it is innate for one to conform to social norms, of which downloading of copyrighted materials is analogous to looting of physical property due to the awareness of the wrongdoing. However, ignorance is no defense and is bliss thus; sharing of copyrighted material over the internet makes, those participating in the issue believe they ar e doing right, but it is wrong. Free file sharing of copyrighted materials leads to the loss of revenue to the all that are involved (Debatepedia). This is concerning the artist not making the amount of financial remuneration that is they should receive. In this light, the artists lose their revenue on a massive scale, meaning that the artists are robbed of their dues, which translates to poor living standards of the said parties. As a result, it is wrong of an individual, in his or her right mind, to deprive another of their deserved standards of living. In relation to the government, the artists that own the copyrighted materials end up making less amounts of money. For this reason, the government rates, which tend to charge higher taxes for increased amounts of revenue, charges the artist less. This means that the government loses large amounts of funds to the pirates that share files for free

Who influence me Essay Example | Topics and Well Written Essays - 750 words

Who influence me - Essay Example It was after several months of training that she went to India and took her initial vows as a nun. Teresa taught at St Mary’s high school in Calcutta from 1931 to 1948. During her stay at the convent, Teresa saw how the poor suffered. This resulted to her being granted permission to go and work amongst the poorest of the poor in the slums of Calcutta. Depending on divine providence, Teresa started an open school at the slums of Calcutta. Fortunately, she was joined by many volunteers and financial aid also increased. As a result, Teresa was able to expand on her line of work (Nobelprice 1979 par 2). Teresa started her own order in October 7, 1990 after getting permission from the Holy See. She named it "The Missionaries of Charity". The task of the Missionaries of Charity was to take care of the less fortunate that had no one to take care of. The Missionaries Charity became an international religious family under Pope Paul IV. Currently the order has active and contemplative branches comprising of sisters and brothers in many countries. Between 1963 and 1984, several branches were established; Contemplative branch of the Sisters and the Active branch of the Brothers was founded in 1963, the Contemplative branch of the Brothers was added in 1979 and the Priest branch was established in 1984. The Missionaries Charity has over the years spread all over the world including the former Soviet Union and some Eastern European countries. They take care of the less fortunate people in continents like Asia, Africa and Latin America. They also assist people affected by catastrophes like, famine, floods and epidemics. The Missionaries Charity society has home all over the world where they take care of, AID’S victims, homeless, alcoholics and even shut-ins. On March 29, 1969, Co-workers aided and assisted the Missionaries Charity to become an official international

Microsoft Windows operating system Essay Example | Topics and Well Written Essays - 500 words

Microsoft Windows operating system - Essay Example But in case of Microsoft operating the market is totally dominated by Microsoft. Based solely on market share, Microsoft appears to have a near-monopoly in operating systems for personal computers yet Microsoft priced the Windows OS very smartly and kept it at bare minimum and thus succeeded in capturing in the market. The law of demand tells us that as the price of a commodity falls, the quantity demanded increases and vice-versa. But the law is silent on the extent of increase in demand as a result of decrease in certain percentage of prices. That means the law of demand tells us only the direction of change, but not the rate which the change takes place. To know about the rate of change we should know the 'price elasticity of demand'. Elasticity of demand can be defined as the "degree of responsiveness of quantity demanded to a change in price." It thus represents the rate of change in the quantity demanded due to a change in price. Now in case of Microsoft it can be said that, if we treat PCs as a single homogeneous commodity, then Microsoft's pricing of Windows was 'not' consistent with its status of a monopoly over personal computer (PC) operating systems. Therefore Microsoft started with such penetrative pricing that consumers had no option but to go for it. The company priced Windows as low as it can because of several types of substitution; For the fi

Free File Sharing Essay Example | Topics and Well Written Essays - 750 words - 1

Free File Sharing - Essay Example In this light, all parties involved in the sharing tend to believe that the internet is a free place for them to give away file to their friends and other interested parties. This occurs especially with the new technologies that are coming up, such as peer-to-peer file sharing and other sites. With such events transpiring, some unscrupulous file owners tend to sell the said files for a profit that they get to spend and rip off the original owners of their dues, both in terms of moral support and financially (Biron). This is tantamount to physical and practical theft, which on a moral scale, and according to social norms, is wrong. In addition, morally, it is innate for one to conform to social norms, of which downloading of copyrighted materials is analogous to looting of physical property due to the awareness of the wrongdoing. However, ignorance is no defense and is bliss thus; sharing of copyrighted material over the internet makes, those participating in the issue believe they ar e doing right, but it is wrong. Free file sharing of copyrighted materials leads to the loss of revenue to the all that are involved (Debatepedia). This is concerning the artist not making the amount of financial remuneration that is they should receive. In this light, the artists lose their revenue on a massive scale, meaning that the artists are robbed of their dues, which translates to poor living standards of the said parties. As a result, it is wrong of an individual, in his or her right mind, to deprive another of their deserved standards of living. In relation to the government, the artists that own the copyrighted materials end up making less amounts of money. For this reason, the government rates, which tend to charge higher taxes for increased amounts of revenue, charges the artist less. This means that the government loses large amounts of funds to the pirates that share files for free

Microsoft Windows operating system Essay Example | Topics and Well Written Essays - 500 words

Microsoft Windows operating system - Essay Example But in case of Microsoft operating the market is totally dominated by Microsoft. Based solely on market share, Microsoft appears to have a near-monopoly in operating systems for personal computers yet Microsoft priced the Windows OS very smartly and kept it at bare minimum and thus succeeded in capturing in the market. The law of demand tells us that as the price of a commodity falls, the quantity demanded increases and vice-versa. But the law is silent on the extent of increase in demand as a result of decrease in certain percentage of prices. That means the law of demand tells us only the direction of change, but not the rate which the change takes place. To know about the rate of change we should know the 'price elasticity of demand'. Elasticity of demand can be defined as the "degree of responsiveness of quantity demanded to a change in price." It thus represents the rate of change in the quantity demanded due to a change in price. Now in case of Microsoft it can be said that, if we treat PCs as a single homogeneous commodity, then Microsoft's pricing of Windows was 'not' consistent with its status of a monopoly over personal computer (PC) operating systems. Therefore Microsoft started with such penetrative pricing that consumers had no option but to go for it. The company priced Windows as low as it can because of several types of substitution; For the fi

Automated Record System of Barangay 38 a Thesis Proposal Essay Example for Free

Automated Record System of Barangay 38 a Thesis Proposal Essay Barangay P.N.P Compound is located in the heart of Davao City particularly situated in the center of San Pedro , Bolton , Rizal and Quimpo Boulevard Sts. Even in the older times it is the center of trade and religious activities. Barangay P.N.P Compound in the late 1940`s used to be a swampy area with barely 20 houses ( more or less ) built from light materials was situated. Since our barangay is located near barangay bucana which is also very near the coastal areas most parts of our barangay is usually submerged in water caused by the changes in the sea level. According to the pioneer residents which is now our senior citizens , the area during Their times were mostly fishponds and crabs were all over the place specially during High tide . However , as time passes by population gradually increase and fishponds Turned into houses and establishments . In the year 1978 , our first appointed Tenyente Del Barrio Mrs. Lourdes Espiritu was placed in the position but during Mrs. Espiritu`s term their were still no kagawads . However due to health problems she Was replaced by barangay captain Angelita B. Maneja who was duly appointed by the City Mayor that time , together with six (6) of her barangay . The first ever barangay election was held during the late 80`s . In 1993 , under The administration of the late barangay chairwoman Paz Oracion , our barangay hall was constructed. Although made with wood and light materials it is still an Accomplishment that needs to be recognized up to the present times. In 1994, Barangay Captain Paz Oracion was re-elected with new set of barangay council. During the May 7,1993 barangay election barangay Chairman aspirants Robert Cepe and Paz Oracion both got the same number of votes . However , by means of â€Å" toss coin â€Å" which was done in front of the Barangay Hall Robert Cepe was declared as the new Barangay Captain . He serve for the position from May – September 1997 . Paz Oracion Field a petition in court and a recount was granted . It was found out that there were Two (2) ballots that were invalidated . As a result Paz Oracion was declared as the Barangay . At present , we have already made may improvements and developments Within the barangay . We have estimated a total number of six hundred houses (600) And population have also increased . We are constantly thankful to the past and Present Barangay Officials , the constituents and all those local Government Units and Officials who have unendingly given their support , effort and dedication in the spirit Of public service which paved the way in making us one of the developed barangay`s In the heart of the City. Statement of the Problems The study will seek to the following question : †¢ How should the current system security problems be solved in order to provide a system which is proof against unauthorized person ? †¢ What is the difference between manual record keeping and automated record keeping . Objectives of the study This study conducted in surveyed for the purpose of city government serve a barangay . †¢ To know how the barangay was created. †¢ How it become a reservation of Philippine National Police or know as P.N.P compound. Significance of the study This signifies as basis of a barangay to ensure the people living in b Barangay the maintenance , peace in order , health and sanitation . Scope and limitation of the study The scope of the study will focus on the computerization of barangay P.N.P Compound . The barangay officials and staff of the said barangay will be the major respondents of the study , being the direct representative of the establishment. The proposed system will be created using Microsoft Visual Basic as the Front end and Database Management System (DMS) as the Back – end . Definition of terms The following definitions are based on the conceptual and the operational definitions †¢ Conceptual Definitions : †¢ Automated automatic the password , store and process †¢ Record a process where the entries are recorded into a storage device . †¢ System instrumentality that combines interrelated interacting artifacts designed to Work as a coherent entity Operational Definitions : †¢ Automated process all the data †¢ Record a process where information is permanently stored in a database . †¢ System a collection of related process that benefits from each other .

Assessment Frameworks of Multiple Stressors

Assessment Frameworks of Multiple Stressors A review of environmental and human health risk assessment frameworks of multiple stressors: the case of endocrine disruptors Abstract This review is a compilation of the recommended approaches and methods for the development of a risk assessment framework of multiple stressors. Some of the driving forces contributing to address this subject are the current demands of stakeholders like the drinking water industry, the society and regulators of evaluating the risks of mixtures of contaminants that may harm human beings and the environment. Therefore, our work aims at exploring the possibility of integrating within the risk assessment, environmental, human and societal aspects, acknowledging new international regulations and policies for the safe use of chemicals which enforce the integrative study of the hazards of multiple chemicals on humans and the environment throughout their life-cycle. We chose the group of compounds called endocrine disruptors as an example of multiple stressors because of their emerging relevance and the fact that they usually integrate complex mixtures, originate from multiple sources and ex ist in several environmental compartments, generating adverse effects on receptors through different routes and pathways. Their actions may be severe chronic and long-term modifications of the normal development and reproduction patterns of the individual and/or its progeny, eventually representing systemic risks at the population level which may affect sustainability and biodiversity. Due to the ubiquity of these chemicals, it is necessary to address the inclusion of human beings as potential receptors and deal with risk assessment in an integrated manner. As endocrine disruptors may provoke differentiated responses relative to the developmental stage, acting through varied mechanisms and at very low concentrations, with the particularity that their toxicokinetics may present sometimes unusual dose-response curves, might challenge long-term predictions and hazard characterization, adding to risk assessment uncertainties. References to the current methodologies including the applica ble bioassays, chemical analysis, modeling, statistics tools and equations to calculate joint effects considering the interactions of toxicants within a mixture are also discussed in this review. KEY WORDS: risk assessment, endocrine disruptors, multiple stressors 1. Introduction The aim of this review is to analyze the risk assessment frameworks and current practices, the integration of environmental and human health methodologies, the effects evaluation and how to assess the risk of complex mixtures of chemicals. Assessing the risks of multiple stressors for human health and the environment arises from the realization that biological and physical stressors usually coexist in complex mixtures in the natural and constructed environment, sometimes generating impacts on living creatures. Historically, since the publication in 1962 of the book â€Å"Silent Spring†, by Rachel Carson, a warning on the deleterious actions on wildlife of persistent toxicants, such as DDT, which caused a decrease of birds in Pennsylvania, became presentwas recognised among the scientific world, the media and the society. More recently, the research by Dr. Theo Colborn on the reproductive disorders of predators in the Great Lakes of North America and her book, published in 1996 â€Å"Our Stolen Future† co-authored by herself with Dianne Dumanoski and John Peterson Myers, was able to generate public awareness on the threats that EDCs might pose to human beings and the environment. Some of the driving forces for writing this review are the demands of stakeholders represented by the community, the NGOs, the health and environmental regulators, the manufacture industrial sector and the drinking water companies. For instance, the European Environment and Health Strategy emphatically stresses the gaps in knowledge related to risk assessment methodologies that include foetuses, infants and children and calls for the precautionary principle within the strategy for environmental contaminants, for which there is a sufficient level of scientific evidence at the effect level (e.g. molecular, cellular, or tissue-related) to show the likelihood of health impacts. Not enough information exists on the link between emissions of dioxins and PCBs and other substances and their accumulation in ecosystems and foodstuffs. The need for research on the understanding of the links between environmental factors and certain diseases is recognized, but, due to the complexity of the issue , the immediate action is to gather evidence in order to concrete measures to protect human health and the environment. Many reports are able to demonstrate through laboratory experiments and field surveys that exposure of animals to chemicals released into the environment exert reproductive or developmental effects on the individual and its off-spring, affecting the viability of the species at a population level (Colborn and Smolen 1997). As a matter of fact, these kind of adverse effects have been observed in wildlife and many of them can be attributed to the exposure to man-made chemicals. The cause-effect relationship is still controversial in human beings, but still a matter of concern due to the severity of probable harm that could affect individuals and populations. Thus, regulatory decisions must be informed by risk assessment on this important topic (Fenner-Crisp 2000). Endocrine-mediated effects may be more relevant in populations rather than in individuals. As there is still not consensus about a cause-effect relationship, it is recommended a science-based precautionary approach to protect public health. Further research is needed to demonstrate effects and carry out birth defect registries and epidemiology studies designed to track delayed effects of environmental exposures (Solomon and Schettler 2000). The classical paradigm of human health risk assessment authored by the National Research Council (NRC, 1983) is composed of four steps: hazard identification, dose-response assessment, exposure assessment and risk characterization. This paradigm was modified in 1994 to include characterization of each component. One of the approaches considered by some authors as best suited for developing a risk assessment of multiple stressors is a cumulative risk assessment framework, which may include societal aspects with participatory involvement of stakeholders (Gentile and Harwell 2001; Callahan and Sexton 2007; USEPA 2003). The global trend towards a policy-driven integration applied to risk assessment, demanded by regulations on safety of chemicals and industrial operations should ideally include a multiplicity of stressors, compartments, geographical scales, and end-points (Assmuth and Hildà ©n 2008). For example, the new European Union Regulation on chemicals and its safe use (REACH, EC 1907/2006) enforces linking risks to human health and the environment for chemicals throughout their life cycle. In United States, the Environmental Protection Agency, still discusses both topics separately because of practical reasons, but acknowledging the need to integrate them. An overview of the most suitable risk assessment frameworks is described in this literature review, focusing on the case of mixtures of reproductive endocrine disruptors. Matters that differentiate this topic are also presented, regarding particularities in mechanistic and toxicokinetics aspects and some of the sources of uncertainties and confounding factors. Developing a novel approach to the classical risk assessment scheme is also a goal, with the intention of contributing to design a risk assessment framework comprising a choice of tests, models, computational and statistical tools. 2. Hazard identification In this stage the nature of the hazard is described taking into account toxicity data. The hazard can then be characterized deriving numerical values of acceptability of the risk, based on mechanisms of action, biological extrapolation, dose-response and dose-effect relationships, and related uncertainties (Fenner-Crisp, 2003). 2.1. Nature of the hazard Endocrine disruptors (EDCs) are substances that interfere with the endocrine system by changing homeostasis and producing developmental effects and/or diminishing the fertility of the organisms. EDCs include a broad range of substances which can be classified according to their effect. The best known are the environmental estrogens, alkylphenol and its ethoxylates, the monomer in polycarbonate manufacture bisphenol A, some pesticides and chlorinated organics. 2.2. Sources of EDCs Possible sources of watercourses pollution with EDCs are wastewater sewage discharge, industrial effluents, or point and non-point source contamination of watercourses with agrochemicals such as herbicides or pesticides. Sewage discharge from cities contains residues of domestic products such as personal care products, pharmaceuticals and detergents and excreta with natural and artificial steroidal hormones from contraceptive pill usage. Nonylphenol (NP) is a highly hydrophobic bioccumulating biodegradation by-product of nonylphenol ethoxylate non-ionic surfactants which persists in sewage sludge and river sediments. Its use and production have been banned in EU countries and strictly monitored in many other countries such as Canada and Japan (Soares et al. 2008). Pulp mills are some of the industries associated to studies on endocrine disruption. Bleached Kraft pulp mill effluents have been linked to both estrogenic and androgenic effects on biota, depending on the process characteristics and wastewater treatment. Several studies have associated the chlorination of organic matter to the estrogenicity of the effluent. Nowadays, the application of elemental-chlorine-free processes has diminished the risk of dioxins and furans formation, but not eliminated it, as other halogenated organics are formed by use of chlorine dioxide as bleaching agent. Various wood-extractive compounds produced in the pulping process, such as rosin acids and phytosterols and found in pulp mills effluents have also been considered potentially responsible of endocrine disruption (Hewitt et al. 2008). The main identified resin acids in pulp mill effluents are: pimaric, isopimaric, sandaracopimaric, palustric, dehydroabietic, abietic and neoabietic acid (Merilà ¤inen and Oikari, 2008). Other compounds found in this type of effluent are phenolic guaiacyl-based lignin degradation products, diterpenoids, and dimethoxy stilbene (Belknap et al, 2006). Modern analytical methods, like full-scan GC-MS have been used to identify wood related extractives in final effluent from a chlorine dioxide bleached pulp mill effluent, including monoterpenes, phenolics, fatty acids, resin acids, resin acid neutrals and sterols (Wartman et al. 2009). Receptor binding bioassays for androgens and estrogens indicated that androgens were most abundant in this effluent and the range of androgens for the various extraction protocols used was 189-283 ng/L as testosterone equivalent concentration. Some examples of common sources of EDCs and typical environmental concentrations are summarized on Table 1. Table 1.Sources of EDCs and typical environmental concentrations Origin, use and occurrence Source of environmental exposure EDC group Example molecule Typical concentrations Reference Industrial (pulp and paper mills) Contaminated fish Resin acids pimaric acid 4-140  µg g-1 Owens et al, 1994 Industrial (pulp and paper mills) Industrial wastewater treatment plant Chlorinated organics 2,4,6-trichlorophenol 1.5  µg l-1 Owens et al, 1994 Industrial (pulp and paper mills) Final stage secondary treatment Phytosterols ÃŽ ²-sitosterol 58.42  µg l-1 Landman et al, 2008 Domestic, (contraceptive pills) Sewage effluent Pharmaceuticals 17ÃŽ ±-ethynylestradiol 14-17 ng l-1 Liu et al, 2004 Human and animal excreta Sewage effluent Natural steroid hormones 17ÃŽ ²-estradiol 5.0 ng l-1 Koh YKK et al, 2007 Domestic and industrial (laundry detergents, wool scouring processes) Sewage sludge Non ionic surfactants 4-nonylphenol 829.3 mg/kg Gonzà ¡lez et al, 2010 Domestic and industrial (polycarbonate bottles) Leaching from solid waste, sewage effluent Polycarbonate bisphenol A 0.62  µg l-1 Sà ¡nchez-Avila et al, 2009 Agricultural (soil fertilization) Livestock waste Male steroid hormones testosterone 10-1830 ng l−1 Lange et al, 2002 Agricultural (dairy farming) Streams contaminated by dairy cow excreta Female steroid hormones 17ÃŽ ²-oestradiol 0.04-3.6 ng l−1 Matthiessen et al, 2006 Agricultural (weed and grass control in soybean crops) Run-off Herbicide glyphosate 0.1-0.7 mg l-1 Peruzzo et al, 2008 2.2. Dose-response assessment There are several methods to demonstrate dose-response relationships, either by in vivo or in vitro tests. Fish reproduction tests, like the ones using the model fish fathead minnow (Pimephales promelas) have shown a decrease in fecundity associated with depressed steroid and vitellogenin (Vtg) production in female specimens (Ankley et al. 2008). Many of the tests rely on the measurement of an increase of Vtg as biomarker of estrogenicity as seen in several publications (Schwaiger et al. 2002; An et al. 2008; Holbech et al. 2006 Panter et al, 1998; Sohoni et al. 2001; Kunz and Fent, 2009). Tests results on resin acids show different responses in the first generation of fish than in the second (Christianson-Heiska et al. 2007). In some cases there are not many examples of in vivo tests, like for glyphosate. A fish exposure tests with this compound showed Vtg induction in female fish, indicative of estrogenic activity (An et al, 2008). An investigation working the commercial formulation of the herbicide glyphosate and human placental cells demonstrated its toxicity at concentrations lower than the usual in agricultural practices. The aromatase activity disruption seems to be due not only to glyphosate but also to co-adjuvants (the surfactant nonylphenol or others), which enhance its bioavailability and/or bioaccumulation (Richard et al. 2005; Gasnier et al. 2009). Table 2 shows some examples of dose-response experiments working with fish, crustacea, molluscs and amphibia. Varied protocols exist to develop ecotoxicity tests, in flow-through, static or partly renewal conditions, and with different duration and end-points. Only chronic effects and particularly developmental and reproductive effects were conside red. Table 2. Dose-response for endocrine disruption effects in freshwater organisms exposed to single EDCs EDC chemical name Taxonomic group Species Dose to produce effect Effect Test conditions Reference 4-nonylphenol Fish Rivulus marmoratus 300  µg l-1 Testicular agenesis and oogenesis inhibition in 100 % fish Static system, daily renewal Tanaka and Grizzle, 2002 4-nonylphenol Fish Oncorhynchus mykiss, rainbow trout 1 -10  µg l-1 10  µg l-1 High Vtg in adult male fish plasma Low hatching rate Intermittent exposure of adult fish for 4 months until spawning Schwaiger et al, 2002 4-nonylphenol Crustacean Ceriodaphnia dubia NOEC for reproduction: 1  µg l-1 Low hatching rate 7 days chronic exposure, static Isidori et al, 2005 Glyphosate Fish Carassius carassius, crucian carp 100% effluent Vtg induction in female fish (38.6 +/- 9.8  µg l-1) 3 weeks, continuous exposure An et al, 2008 Glyphosate Mollusk Pseudosuccinea columella, aquatic snail 1 mg l-1 10 mg l-1 Faster development of F3 embryos Hatching inhibition 3 generation continuous Tate et al, 1997 Estrone Fish Danio rerio LOEC: 14 ng l-1 50 ng l-1 Significant Vtg increase Higher female ratio 40 days fish sexual development test Holbech et al, 2006 17ÃŽ ²-Estradiol Fish Danio rerio LOEC: 54 ng l-1 Significant Vtg increase Higher female ratio 40 days fish sexual development test Holbech et al, 2006 17ÃŽ ²-Estradiol Fish Pimephales promelas, fathead minnow 100 ng l-1 Significant Vtg increase Testicular growth inhibition 21 days male fish exposure Panter et al, 1998 Estriol Fish Danio rerio LOEC: 0.6  µg l-1 21.7  µg l-1 Significant Vtg increase Higher female ratio 40 days fish sexual development test Holbech et al, 2006 Dehydroabietic acid (DHAA), resin acid Fish Danio rerio, zebra fish 50  µg l-1 Low plasma Vtg in female in F0; high Vtg and affected spermatogenesis in F1 males 2 generations, continuous Christianson-Heiska et al 2008 ÃŽ ²-sitosterol Fish Danio rerio 10-20  µg l-1 F1: higher ratio of male fish; F2: higher ratio of female fish 2 generation fish exposure test Nakari and Erkomaa, 2003 Quercetin, phytoestrogen Amphibian Xenopus laevis, frog 200  µg l-1 Higher female ratio > 10% abnormal testes (some with ovotestes) Exposure up to 1 month post-metamorphosis Cong et al, 2006 Phenanthrene, PAH Fish Oryzias latipes, Medaka NOEL: 100  µg l-1 Developmental, hatching 18 days, renewal Rhodes et al, 2005 Bisphenol A Mollusk Marisa cornuaretis, aquatic snail NOEC: 640  µg l-1 Developmental 12 weeks, juvenile snails Forbes et al, 2007 Bisphenol A Fish Pimephales promellas 16  µg l-1 640 and 1280  µg l-1 640  µg l-1 1280  µg l-1 Altered spermatogenesis Growth inhibition and Vtg induction in male fish Reduced hatchability in F1 generation Egg production inhibition 3 generation reproduction exposure test Sohoni et al, 2001 Bisphenol A Fish Brachydanio rerio, zebrafish EC50: 2.90  µg l-1 Embryo malformation and low hatchability 72 h exposure Liu et al, 2007 Benzo-ÃŽ ±-pirene (BaP) (PAH) Fish Fundulus heteroclitus , common mummichog 10  µg l-1 CYP19A1 expression decreased by about 50% in immature stage I oocytes Exposure for 10 or 15 days by in situ hybridization, several developmental stages Dong et al, 2008 Polychlorinated biphenyl 126 Fish Danio rerio, zebrafish LC50: 3.270 mg l-1 Developmental effects through aryl hydrocarbon receptor activation Dilutions of PCB 126 for 12 weeks SiÃ…Å ¸man et al, 2007 Polychlorinated biphenyl 126 Fish Salvelinus namaycush, lake trout 3 ÃŽ ¼g kg−1body weight Retinol depletion Oral exposure for 12 weeks; confirmation with radiolabelled retinol Palacea et al, 1997 Benzophenone-1 Fish Pimephales promelas 4919  µg l-1 Vtg induction 14 days exposure, semi-static, renewal Kunz and Fent, 2009 3. Exposure assessment 3.1. Ecosystems and human sub-populations potentially at risk of endocrine disruption effects Increasing evidence generated by scientists turn endocrine disruption into a recognized risk to the environment. Due to the ubiquity of EDCs and the widespread routes of exposure, most ecosystems and human populations are potentially at risk of endocrine disruption. Notwithstanding this fact, under the scope of a risk assessment of EDCs the potentially most vulnerable risk subgroups are identified corresponding to maternal, fetal and early developmental stages. The concern that prenatal or childhood exposure to EDCs may be responsible for abnormalities in human sexual and reproductive health are still in the hypothetical ground. However, many reports on exposure to high concentrations of recognized EDCs such as DES, certain PCBs, and DDT demonstrate this fact. At low-doses the question remains unanswered whether there could be a critical window where they could harm the fetal development (Hood 2005). Several reports on human developmental anomalies and reproductive ailments have been raising international concern, such as a seven fold increase risk of testicular cancer since 1969 to 2002 in men from several countries of Europe, United States and New Zealand. Also, the sperm density halved, as rates of cryptorchidism (undescended testicles) and hypospadias (shortened urinary tracts) simultaneously rose. It is thought that human congenital malformation of sex organs, low sperm quality, endometriosis, reduced fertility and some types of cancers of breast and testis could be linked to exposure to EDCs. More than 80000 synthetic chemicals are produced in the world and have still not been fully evaluating with regards to endocrine disruption. In 1996, the U.S. Environmental Protection Agency initiated an Endocrine Disruption Screening Program to evaluate more than 15,000 chemicals calling for a policy based on the â€Å"precautionary approach† to be overcautious and protect huma n health and the environment. A historical example of policies which demanded the banning of a drug due to these after-effects is the case of diethylstilbestrol (DEADES), which used to be prescribed to pregnant women to prevent spontaneous abortions because it produced higher risk of genital deformities and cancer in the offspring, among other effects (Stair 2008). Internationally there is consensus that the most vulnerable group for EDCs exposure are children. For example, in European countries, the Strategy for Environment and Health known as â€Å"SCALE† for Science, Children, Awareness, Legislation and Evaluation, has set as a priority agenda for the evaluation diseases caused by endocrine disruptors in children. The exposure to insecticides and herbicides used in agricultural practices has been linked to developmental or reproductive effects in wild animals and also in human beings. The occupational exposure to pesticide has received much attention, as for example prolonged time-to-pregnancy was observed in male greenhouse workers exposed to pesticides before conception of their first pregnancy (Bretveld et al 2008). The domestic exposure of children to residues of pesticides in low-level long-term exposures are associated to chronic effects and include routes of exposure such as fruit or breast milk (Goodman and Laverda 2002). 3.2. Evidence of endocrine disruption effects in wildlife around the world There are reports on impacts on wildlife reproduction and development observed in invertebrates, fish, reptiles, birds and mammals, sometimes confirmed by laboratory tests. In laboratory experiments the impacts to fish populations by EDCs affect reproductive health and persistence of various fish species (Mills and Chichester 2005). Many examples of impacts due to exposure to endocrine disruptors exist in wildlife, such as the seals population decline in the Baltic and North Sea, the high levels of female egg yolk in male fish or snail imposex and intersex around the world. Intersexuality of fish has been demonstrated in several investigations carried out in rivers around the world. The findings of abnormal reproductive female-like ducts and oocytes in male fish were related to the treated sewage discharge from the cities in laboratory experiments measuring induction of plasma vitellogenin in exposed male fish (Jobling et al. 2002). Field studies were carried out using wild roach as a model fish to confirm the incidence and the severity of intersex which correlated with the predicted concentrations of the natural estrogens (E1 and E2) and the synthetic contraceptive pill estrogen (EE2) present (Jobling et al. 2006). Some case-studies have made clear that the estrogenic activity of municipal wastewater correlates to demographics. The number of inhabitants was found to correlate with changes in estrogenic activities in a research conducted at a university city in US, with seasonal fluctuations in population. The concentrations of synthetic and natural estrogens and other EDCs were measured and effects demonstrated through the application of in vivo and in vitro tests (fish exposure with Vtg induction measurement and the yeast estrogen screen) (Brooks et al. 2003). The demonstration of effects of pulp mill effluents has also been supported by fish surveys with a sampling design that includes upstream and downstream sites from the discharge pipe of the pulp mill. For instance, Munkittrick et al. (1994) have demonstrated that the absence of chlorine bleaching or the presence of secondary treatment does not eliminate estrogenic responses evidenced by decreased circulating levels of sex steroids, decreased gonadal size, which implies that there may be multiple causative agents. In other cases, androgenic effects have been noticed, such as a biased male to female ratio in fish in Sweden downstream from pulp mills (Larsson and Fà ¶rlin 2002). As seen on Table 3, several adverse endocrine effects are evidenced in various animals, from mollusks to amphibian but they also appear in higher animal species. Table 3. Effects of EDCs in wildlife evidenced through field studies Animal Effect EDCs Postulated mechanism or causative agent Reference Frog High incidence of deformed frogs in Minnesota, United States Multiple EDCs Retinoid signaling pathways activation Gardiner et al. 2003 Marine Gastropods Masculinization of female snails (imposex) occurs worldwide. Females grow accessory sex organs including sperm ducts, seminal vesicles, external sperm grooves, and penises. Exposure to low levels of tributyltin (TBT) (1ng/l) Aromatase inhibition, testosterone inhibition, or neuroendocrine disorder or interaction with retinoid receptors Novà ¡k et al. 2008 Wild roach (Rutilius rutilus) Intersex, and high plasma Vtg concentration Multiple EDCs Sewage effluent from wastewater treatment plant discharging into rivers Joblin et al. 2006 Mosquitofish (Gambusia affinis) Masculinization (90% affected in number of segments in the longest anal fin ray). Androgen-dependent gene expression by luciferase test Kraft pulp mill effluent Affinity for human androgen receptor (hAR) Parks et al. 2001 Eastern Mosquitofish, (Gambusia holbrooki) Androgenic activity measured by androgen receptor transcription assay with human receptor in sediment. Fish masculinization. Paper mill effluent, river Pine pulp-derived phytosteroids accumulate in river sediment where they are converted by microbes into progesterone and this into androstenedione and other bioactive steroids Jenkins et al. 2003 3.3. Conceptual model Deriving a conceptual model requires knowing the pathways and toxicokinetics of the EDCs identified in the hazard identification step. An effects-based assessment start by identifying the effects and the relevant stressors and geographically located (for example through the use of GIS software). On the other hand, the model used in stressor-based assessments, depicts how stressors affect receptors and it is commonly applied when evaluating risks of environmental pollution. If a river basin is evaluated, the sources of contamination are studied, identifying the pathways, receptors and effects. To develop the human health risk assessment component, the fish consumption of the population and the drinking water intake are two of the main factors to consider especially for the most vulnerable population, which are newborn and lactating infants. The food chain is the main source of exposure, and in particular, fish consumption and drinking water are possible sources for the nursing mother and the pathway of distribution through the milk to the baby, but the direct intake of drinking water is important in the case of formula preparation. The environmental risk assessment should consider fish, crustacean and sediment dwelling organisms within the framework. During pregnancy maternal fat is moved, releasing to the blood the bioaccumulated compounds, due to their liposolubility and persistence, through all the different exposure routes (foodstuffs, environmental, occupational) throughout her life. Acute exposure should also be considered if it happened previously to gestation or during this period. There are substances that traspass the placental barrier and chemicals reach the offspring. Also, through the breastmilk, explaining the extrangely high levels of some xenobiotics (Fernà ¡ndez et al. 2007). 3.4. Methodologies to determine dose-response in exposure assessment The analysis of exposure and effect determines the concentration of the EDC on the environment matrixes matrices (water courses, ground water, drinking water, soil, sediment, air, biota), and assesses the potential or actual effects. In order to do so, many tools are recommended and in general a tiered approach is the most suited for this task as it helps to work in a logical order and increasing the specificity of the tests. One of the main sources of exposure to most chemicals is through the food chain. The bioconcentration of organics in beef, cow milk and vegetation correlates to the octanol-water partition coefficient (Kow) to predict the bioaccumulation in the aquatic and terrestrial food chains (Travis and Arms 1988). There are many models based on the characteristics of the chemicals, such as the fugacity model, which allows to predict the expected concentrations in six environmental compartments (water, air, soil, bottom and suspended sediment and fish) (MacKay et al. 1985). 3.4.1. The use of a tiered methodology to demonstrate endocrine disruptive effects This type of approach is carried out including different tests, such as bioassays, in vitro tests and field studies as part of the experimental design. The methodologies generally employed are in vivo fish reproduction exposure tests and in vitro receptor binding bioassays, for androgens and estrogens (Wartman et al., 2009). Even though there is an international trend towards diminishing the use of live organisms for experimentation for safety testing, in vivo tests are still of key importance for the confirmation of the findings of in vitro screens. Some of the most utilized tests relay on the use of fish as model experimental organism in various life-stages, as for example the 21 days reproduction fish test with fathead minnow (EPA/600/R-01/067). 3.4.2. In vitro screens and tests Some of the in vitro assays that can be used as screening tools of estrogenic activity are the following: yeast based assays, cell proliferation assays, bindin

The Half-Brothers by Elizabeth Gaskell Essay -- Papers

The Half-Brothers by Elizabeth Gaskell This story, The Half-Brothers, written by Elizabeth Gaskell is set in 19th century Cumberland. This story is based on some of things that happened in Mrs Gaskell's life such as her losing her children. The half brothers are Gregory and his younger brother whose name we never find out. Their mother loses her first husband and she re-marries William Preston. Their mother, Helen, dies in childbirth leaving Gregory to be brought up by his stepfather. Even though he had been badly treated by him, Gregory shows throughout that he is a true Christian. Mrs Gaskell in this story makes Helen into a very sympathetic character. The very first sentence 'My mother was twice married' is made to make us feel sympathy for her because we know that something bad must have happened in her first marriage but we don't know what it is until later on in the paragraph. Helen is also made a sympathetic character by Mrs Gaskell listing a series of dreadful events that happened to Helen. Saying how young she is 'She was barely seventeen' makes us feel sympathetic for Helen knowing that she is young and helpless. We also begin to think from this that she is too young to be married. The grief occurs when she loses her husband and she is left to look after a young child on her own. She was only just able to walk. We begin to think things are getting better for her when her sister comes to help her. They had a plan. 'They plotted how to make every penny they could'. Everything goes wrong. 'The farm on her hands for four years or more by the lease'. We feel sympathy for her knowing that she has too much to cope with on h... ...to cope with in such a short space of time. Another sentimental point is all the things that happened to Helen, such as her losing most of her family and becoming helpless. Sentimentality is formed from William Preston's last request. We know that he really is deeply sorry for the way he treated Gregory. The description of Gregory's body when he dies is very easy to make a picture in your head because it is described so detailed. I don't think the story is over-emotional or exaggerated. It is written very well and the sentimental parts of the story are brought out and expressed well. Sentimental means that something is dear to you and that it means something to you. The things that happen to Helen in the story are very closely related to things that happened in Mrs Gaskell's life and therefore are sentimental to her.

College Has Exceeded My Expectations :: Personal Narratives Flagstaff College Essays

College Has Exceeded My Expectations A new place to live, new friends, a new diverse campus, new classes, and even a newfound freedom: that was what I found waiting from me the first day I moved up to Northern Arizona University. These were the things I was in search for when I was looking through all of the different colleges that I could possibly go to. NAU had them all but most importantly, NAU had a wonderful communications program, which just made everything a little better. Having lived in the same cozy house in Tucson for all my life, I wanted a change of scenery and from the hot climate. So as I started my search for the perfect college I would look to see if I could live on campus, or anywhere out of Tucson. Coming up here to NAU I am given a chance to live in a new place, McConnell Hall, and have pride in the place that I live. It is wonderful being able to say that I live here and it is my own room. I know it is not a house or an apartment, but it is still fantastic for a first move. I would not choose to live anywhere else at this moment in my life than to live on campus. You get to meet so many different people and there’s usually something going on, most of the time it just random things though. What is great about living on campus is how random people just show up in your room. Knocking is not something that is known to people who live in my hall. It is not uncommon for people to just walk in to talk, or if they do knock, they knock once while they are walking in. It is great way to meet people, mostly friends. People come into your room to steal ideas of how they should put things in their room, to borrow things such as a screwdriver or just a can opener, or to even just hang out. What was cool was that I meet a friend of mine in the bathroom when she got her hand stuck in a vase she was washing. In the dorms you meet people in irregular ways, but it makes for great conversations later on.