US Presidents and the Presidency Essay Example | Topics and Well Written Essays - 4500 words

US Presidents and the Presidency - Essay Example The most outstanding leaders in American history include the founding fathers or early leaders: George Washington, John Adams, Thomas Jefferson; those who presided in times of internal and external conflict: Abraham Lincoln, and Franklin D. Roosevelt; intercontinental political leaders like James Monroe who declared the American hemisphere off-limits for European colonialist invaders; Woodrow Wilson and his isolationist and international concepts. Erstwhile stately global leaders presiding throughout the Cold War period like Harry S. Truman, John F. Kennedy. Other notable presidents are those who rebuilt the American economy including Ronald Reagan and Bill Clinton. The 21st century has heralded the threat of international terrorism particularly against American interests in addition to the current global financial crisis. The 43rd president George W. Bush was the first president of the new millennium who has been accused of inciting and provoking the wrath of the Islamic terrorists. The current president, Barrack Obama is also remarkable historically in being the first African American president in addition to have being the only one born outside the continental USA. One of the most outstanding American presidents is Abraham Lincoln the 16th US president, who has been credited for his significant leadership, preserving the United States union when it was threatened by bitter internal turmoil from the breakaway southern Confederate states. The main cause of the conflict was the latter opposition to the abolition of slave trade in the US intended to grant African Americans freedom; hence, he is accredited for ending slavery in America. Lincoln successfully consolidated his power base within the Republican Party by integrating the moderate Copperheads faction and the abolitionist Radical Republicans as well as gravitating public opinion to his favour. During his famous Gettysburg

Horror in Frankenstein Essay Example for Free

Horror in Frankenstein Essay There are many forms of tension and horror in this novel. There is a monster, theres grave robbing, the whole story is against religion and it is warning the reader that trying to play God can only have bad consequences. The novel is controversial in its content and it focuses on peoples prejudice and discrimination together with how people judge others too readily. Another thing that could have been scary for the readers at the time is the idea of electricity bringing life. Since electricity was a reasonably new thing, the concept of this new, weird technology described in the book could have been seen as horrific. Also, the atmosphere was a big part of the horror and tension, pathetic fallacy was used when Dr Frankenstein was creating his monster It was already one in the morning; the rain pattered dismally against the panes, and my candle was nearly burnt out, It was strange, at the time of the novel being published, for a woman to write a book quite as horrific as Frankenstein. There were many things which could have influenced Mary Shelley in writing a book of this sort, myths, religion, other novels. She could have been influenced by the legends of the poles when creating Robert Waltons character. She was most likely to have been influenced by scientific research and advances at the time such as discovering electricity. She could have been trying to get people to understand that this type or research and messing around with life and death were wrong. Lastly I think she also had literary influences and I believe that Mary Shelley wanted the novel to be romantic in a way. Mary Shelley creates a lot of tension in the novel, this all starts in letter four from Robert Walton to his sister. She does this very effectively the whole way through the letter, the first line shows this, So strange an accident has happened to us that I cannot forbear recording it it then takes Walton quite a while to get to the point of explaining the accident, this creates a lot of tension. The whole story about Victor Frankenstein and the events in the letter four are told slowly and gradually adding to the sense of tension, mystery and intrigue for the reader. This effect is carried on throughout the whole novel which is, I think, one of the main reasons for the novel being so well known and enjoyed. There are quite a few causes of tension in letter four, another example is when Waltons ship was surrounded by ice, which closed it in scarcely leaving her the sea-room in which she floated. This creates tension by giving the impression of them being trapped in a dangerous environment. After this, the spotting of the creature creates tension, we perceived a low carriage a being which had the shape of a man, but apparently of gigantic stature, sat in the sledge. The fact that this is a creature unlike a normal person adds to the tension. Also as the crew and Walton thought that they were alone, being away from civilization, trapped on a boat with a strange creature nearby creates fear as there would be no help at hand if needed. The next thing that created tension was having Dr Frankenstein on board; he was quite a strange person and did not appear normal. When he was found he asked Walton where he was going before he boarded. This, under the circumstances, is a weird question to ask. Walton wrote, You may conceive my astonishment on hearing such a question from a man on the brink of destruction.

Under Article 223-6 of the French Penal Code(Chapter

Under Article 223-6 of the French Penal Code(Chapter Under Article 223-6 of the French Penal Code(Chapter III, Section 3)..'anyone who wilfully fails to render to a person in danger any assistance which, without risk to himself or to third parties, he could render him either by his own action, or by initiating rescue operations..' is punishable by imprisonment and fine. Essay Question: What is the criminal law in England and Wales on liability for omissions to act? Having regard to the above extract from the French Penal Code, critically discuss whether the current English Law on this issue should be changed. The criminal law in England and Wales on liability for omissions to act: Unlike the French Penal code, which provides a general duty on all persons to assist others in peril according to their abilities, breach of which is a specific offence in its own right, English criminal law does not impose a general duty to act to save other people or property from harm, even if this could be done without any risk or inconvenience. For example, a man who simply stands and observes a child drowning in a shallow pool when he is in a position to easily rescue it should he choose to do so, commits no offence under English law, because he is not under a duty to rescue it. A duty to act may however arise under a contract, the most obvious example being where the failure to fulfil a contractual obligation is likely to endanger the lives of others. Liability is not necessarily precluded by the injured person not being a party to the contract; in the case of Pittwood[1], the defendant, who was a level-crossing keeper, in breach of his contract of employment, failed to close the gate when a train was approaching, resulting in someone dying on the crossing. Wright J confirmed that criminal liability can be incurred from a person’s failure to perform their contractual duty and held that, in this case, a duty was owed to the road users even though, prima facie, the contractual obligation was owed only to the railway company. A person who holds a public office, such as a police officer, may also be under a duty to care for others. For example, in the case of Dytham[2], a uniformed police officer failed to act when he saw a man being kicked to death a few yards away and was convicted on charges of ‘misconduct in a public office’. Likewise, a parent is under a duty to save his/her young child from harm; a parent who has allowed his/her baby child to starve to death may, depending upon his/her state of mind, be convicted of murder or manslaughter[3]. Other close relationships may also involve a similar duty[4], such as between a husband and wife, although this particular example might be more akin to a contractual duty arising from the contract of marriage than to the duty in the above example. The voluntary carer of a person unable to look after him/herself is also bound by a duty of care towards that person under English criminal law. In Nicholls[5], the defendant received a young child into her care, on the death of that child’s mother. Brett J directed the jury that if a person chooses to take on the care of someone who is helpless, either from infancy, infirmity or mental illness, he is bound to execute that responsibility and, if he allows him/her to die, he may be guilty of manslaughter. In Stone[6], this principle was extended to include situations where a person does not overtly accept the responsibility of carer, but where the situation has lead to such; for example, in a situation where two people have lived together for some time, and the health of one of those people deteriorates to a state where they become dependent upon the other for care, then the court may be prepared to imply a voluntary undertaking of care from the very fact that the healthy party did in fact oblige[7]. Such a duty will of course be extinguished if the relationship between these two parties should end, or if the ill party orally releases the other from his/her responsibilities [providing of course that the party is in a state capable of making a rational decision]. An example of this latter situation might be a patient releasing her doctor from his duty of care towards her by instructing him that should she become ill, she does not wish to be treated. Such an advance refusal will only be effective if the patient is fully compos mentis, has not been unduly influenced in respect of her decision and has contemplated the actual situation which will arise, understanding all the consequences of refusing treatment in such a situation[8]. A duty of care can also arise from an accident; where the accused inadvertently and without the appropriate mens rea performs an act which places a person or property in danger, but before the resulting harm is complete, becomes aware of the train of events caused by his inadvertent act, then that party is, by virtue of the English criminal law, under a duty to take such steps as lie within his power to try to prevent or reduce the risk of harm; if he does not, then he may be criminally liable for the consequences. The case authority for this special duty situation is the case of Miller[9], in which the defendant had, quite by accident, fallen asleep in the plaintiff’s house with a lit cigarette in his fingertips. He awoke to find that he had set the mattress of the bed, in which he was sleeping, alight, but rather than raising alarm or trying to extinguish the fire, he simply went into the adjacent room and fell asleep in there. The House of Lords affirmed his conviction for arson, contrary to s1(1) and (3) of the Criminal Damage Act 1971, as he was in breach of his duty to take reasonable care to extinguish the fire which he had accidentally caused, being in a position to do so. As yet there is no clear authority on how much of a risk a person under such a duty to act might be expected to run in order to perform that duty, but the common law duty requires ‘reasonable’ steps to be taken, a criterion which will be assessed in light of all the circumstances of the particular case in question. So far we have focussed our discussion around the duties of ordinary citizen’s in daily life as developed by the English common law. It should be noted that there are also in place many statutory schemes of regulation in regard to industry and commerce, such as the offence of failing to comply with a limitation, condition or notice contrary to the Radioactive Substances Act 1993. There are also statutory schemes for the distribution of public money, such as the failure to notify a change of circumstances under the Social Security Administration (Fraud) Act 1997, and schemes for other licensed regulated activity such as failing to report a road accident. These statutory schemes are simple rules which must be followed as a condition of engaging in these activities, and are relatively non-contentious in their lack of general application to the ‘ordinary citizen’. Critical discussion regarding the issue of whether the current English Law, as described above, should be changed so as to be more like the law contained in Article 223-6 of the French Penal Code(Chapter III, Section 3): As we have seen from the above description, English criminal law does not generally criminalize the failure to render assistance to another citizen who is in peril, even where such assistance would be easy and cause no harm to ourselves. In contrast, the law under Article 223-6 of the French Penal Code (Chapter III, Section3), as quoted within the question of this essay, does create a general duty to rescue, and does criminalise such omissions. The position of the English criminal law in not generally criminalising such omissions might be defended on grounds that the vagueness of the terms involved with criminalizing such omissions [such as ‘reasonable steps’] would leave citizens with no clear warning of what they must do and when [the principle of ‘fair warning’]. It may also be defended on grounds that this resulting uncertainty would have a weakening effect on the rule of law and would also lead to too great a reliance on prosecutorial discretion in defining the effective scope of such omission criminalisation. The English position might be best defended however by adherence to the principle of autonomy; â€Å"the imposition of a duty to act restricts one’s liberty to pursue one’s own ends and desires by requiring one to do a particular thing at a particular time.† The position of the French Penal Code in generally criminalising such omissions might be defended on grounds that more important than the principles of fair warning, rule of law and individual autonomy is the protection of human life and human safety. A. Ashworth and E. Steiner[10] argue that Article 223(2) is a deliberate attempt to set the protection of one citizen’s life or safety above the protection of the maximum liberty of other citizens. The position might also be defended by the fact that since its introduction in 1941, this French Penal Code, responsible for generally criminalising a failure to rescue, has not been considered oppressive[11] in the way that vehement advocates of the English approach might lead one to believe such a law would. The truth is that both the English and the French approach in regards to liability for omissions to act have their respective shortcomings. The English approach does not afford enough weight to the worthy protection of the fundamental interest in human life and safety; the French approach does not afford sufficient attention to the worthy principles of autonomy, fair warning and the rule of law. Perhaps the solution therefore would be a compromise? I believe that the lesson English criminal law should learn from the Penal Code of our Continental comrades is the importance in recognising the harms involved with not helping a person who is in peril; English law must retain its firm stance with regards autonomy, fair warning and rule of law, but simultaneously afford a greater degree of attention to the protection of the fundamental interest in human life. As M. A. Menlowe[12] writes: â€Å"†¦when fundamental interests are involved (life, physical integrity), we should pause before accepting that an individual’s freedom of action is more valuable than a requirement to carry out a non-burdensome rescue.† In conclusion therefore, I would argue that perhaps a compromise should be employed by the English criminal law; a ‘duty of easy rescue’. The law should criminalise omissions to rescue those in peril where such a rescue is a simple and harmless task, but should not punish someone for not engaging in a rescue attempt when the risks associated with such a rescue are uncertain and complicated. Pessimists might argue that it would be too difficult to create a law which attempted a balance between on the one hand the respect for autonomy, adherence to the principle of fair warning and adequate protection of the rule of law, and on the other, a respect for protection of the fundamental interest in human life, but such critics should bear in mind that these three former principles are often found balanced with other interests throughout English law. As Feinberg remarks: â€Å"similar line-drawing problems exist throughout the law, and most have been found manageable.[13]† Bibliography A. Ashworth and E. Steiner ‘Criminal Ommissions and Public Duties (1990) 10 Legal Studies 153 A. Ashworth, ‘Principles of Criminal Law’, 3d. Oxford University Press 1999 p50 M. A. Menlowe. ‘The Philosophical Foundations of a Duty to Rescue,’ in M. A. Menlowe and A. McCall Smith (eds), The Duty to Rescue (1993) Feinberg, Harmless Wrongdoing, xii, summarising his argument in ‘Harm to Others’ 150-9 (1984) Cases cited: Pittwood (1902) 19 TLR 37 Dytham [1979] 3 All ER 641 Gibbins (1918) 82 JP 287 Smith [1979] Crim LR 251 Nicholls (1874) 13 Cox CC 75 Stone [1977] QB 354 Re T [1993] Fam 95 Miller [1983] 2 AC 161 Footnotes [1] Pittwood (1902) 19 TLR 37 [2] Dytham [1979] 3 All ER 641 [3] Gibbins (1918) 82 JP 287 [4] Smith [1979] Crim LR 251 [5] Nicholls (1874) 13 Cox CC 75 [6] Stone [1977] QB 354 [7] Stone [1977] QB 354 [8] These criteria were first set out in the case of Re T [1993] Fam 95 [9] Miller [1983] 2 AC 161 [10] A. Ashworth and E. Steiner ‘Criminal Ommissions and Public Duties (1990) 10 Legal Studies 153 [11] A. Ashworth, ‘Principles of Criminal Law’, 3d. Oxford University Press 1999 p50 [12] M. A. Menlowe. ‘The Philosophical Foundations of a Duty to Rescue,’ in M. A. Menlowe and A. McCall Smith (eds), The Duty to Rescue (1993) [13] Feinberg, Harmless Wrongdoing, xii, summarising his argument in ‘Harm to Others’ 150-9

The Law Of Evidence

The Law Of Evidence Smooth muscle is one of three muscle fiber types found in animals. Unlike skeletal and cardiac muscle cells, smooth muscle cells are not striated, and have single nuclei. Smooth muscles are typically under control of the autonomic nervous system, and do not contract voluntarily. Smooth muscle contracts slowly, and does not exhibit the characteristic twitch seen in skeletal muscle. In addition, smooth muscle is not prone to muscle fatigue, making it an ideal component of sphincter muscles. Smooth muscle is found in the gastrointestinal tract of many animals, and is responsible for peristaltic movements. Smooth muscle contractions are affected by calcium and potassium ions. Calcium ion influx into the smooth muscle cell initiates a contraction. Potassium ion concentration in the extra cellular medium affects the resting membrane potential of the cell, bringing it closer to or farther away from its threshold voltage. Neurotransmitters affect different types of smooth muscle differently, depending on the association of the smooth muscle with excitable cells. In general, acetylcholine increases the muscle cells permeability to calcium, while epinephrine decreases the cells permeability to calcium. Introduction and aim of the experiment The following report was to test a smooth muscle which was collected from the intestine of a rabbit. The main of this experiment was to see how the surrounding environment of the muscle could affect how muscle contracted. The experiment consisted of different environments and the muscle was monitored and results were recorded of the amplitude and the frequency of the wavelengths. The levels of muscle contractions and relaxations were measured using a transducer, a D.C amplifier, and a laboratory computer. Overview of experiment The smooth muscle was a small part of the intestine which was prepared correctly by trimming off the attached mesentery and fat. This experiment only required one piece of this smooth muscle and this was then placed into a beaker which was aerated and fed Ringer-Locke solution this is an aqueous solution containing the chlorides of sodium and potassium and calcium that is isotonic to animal tissues. The experiment only required one piece of small intestine, which had the length of 2-3 cm long. The intestine was held in place with a tissue holder, and was attached to the transducer via a piece of string. The transducer detected contractions and relaxation of the muscle, and via the D.C amplifier showed on the computer the frequency and strength of the contractions and relaxations. The solution that the muscle was placed in was kept at the temperature of 37 Celsius apart from when the environment condition changed was the temperature. This type of setup is known as in vivo preparation. This preparation of the smooth intestine allows a precise control of the environmental conditions. Brief description of test carried out The test which was carried out had six parts to it. The first part of the experiment was to gain initial control of the muscle this was done by having optimum conditions for the smooth muscle so it could achieve a steady rate of contraction and relaxation. This was achieved by adding Ringer-Locke solution and keeping it aerated. By having this set up it allowed the muscle environment to be very closely met to the ideal body environment where the muscle would have a good contraction and relaxation rate. The muscle was left in this preparation until the readings on the computer were constant (about 4 minutes) the initial control was labelled using the comment bar. The next environment was non-aerated this meant to turn the air supply off which was coming to the bath where the muscle was held. Then the Ringer-Locke solution was removed from the bath and fresh Ringer-Locke solution was then placed into the bath. The reason for removing the old solution was to prevent any inaccurate readings as the solution could still have contained oxygen which would have affected the results. This part of the test was recorded after every 5, 10, 15 minutes and the results where inserted into a table. The main purpose of using this environment was to see what the muscle contractions and relaxations are when there is a lack of oxygen. This part of the experiment was again labelled on the comment bar. The next part of the experiment was to remove the Ringer-Locke solution and replace it with 50ml of glucose free solution and again results were recorded after every 5 ,10, 15 minutes and recorded into a table. The fourth different environment was change in temperature. The Ringer-Locke solution of 37 Celsius was replaced with a Ringer-Locke solution that was cooled to 4 Celsius. The purpose of this environment was to test the muscle activity in a cold environment and to analyse the effects. The fifth environment involved the use of calcium free solution this replaced the Ringer-Locke solution. This was analysed for 5 minutes to see how the muscle activity was affected. The final environment was to do with changes in the pH. The pH was changed from pH7 which is neutral to a different pH. The solution with different pH was prepared before hand and the purpose of this environment was to see what effect a pH change would have on the muscle activity. After each part of the experiment initial control was established before moving on to the next part the reason for this being to keep the muscle running properly before each part of the experiment and to cause less damage to the smooth muscle. Also each part of the experiment was labelled on the comment bar this was done to show each different part clearly so it was not confused. (Clear methods are shown in the printouts) Results table for my experiment Firstly the results achieved ere done by looking at the different graphs and to work out the amplitude for the graph the following was done: Example (Graph not related to report) To work out the amplitude of the graph recording two figures were recorded one being the peak of the wave and the other being the lowest part of the wave To work out the frequency for each part of the experiment the amount of waves were recorded in a minute time period. The frequency in this case was how many times the muscles contracted and relaxed in a minutes. The amplitude was the strength of each contraction and relaxing of the muscle. The maximum and minimum amplitudes were collected for each environment and recorded; the amplitude chosen was picked at random as well as the minute where the frequency of waves was calculated. These are results are shown in the table below: Environments Frequency per Minute (min-1) Amplitude 1 Amplitude 2 Maximum Minimum Maximum Minimum Initial control 15 2.10 0.78 1.96 0.65 Non aerated 5 Mins 13 1.94 0.47 1.89 0.38 Non aerated 10 Mins 17 1.53 0.36 1.51 0.38 Non aerated 15 Mins 16 1.58 0.38 1.54 0.36 Lack of glucose 5 mins 17 1.34 0.47 1.49 0.41 Lack of glucose 10 mins 17 1.51 0.43 1.52 0.45 Lack of glucose 15 mins 17 1.37 0.45 1.43 0.46 Cold ringer solution 5 Mins 14 1.76 0.44 1.73 0.51 Calcium Lack 5 Mins 12 1.15 0.63 .95 0.47 Change of pH Flat No waves Discussion of results Firstly a diagram of the intestine is needed to show how it works and what different types of cells it contains. This is needed as it will help to understand why the muscle behaved differently when tested with six different environments. A diagram of the small intestine is shown below; The small intestine contains the 4 basic layers which are serosa, muscularis, submucosa, and mucosa. Small intestine wall is composed of the same four layers that make up most of the gastrointestinal tract: serosa, muscularis, submucosa, and mucosa. The mucosa is composed of a layer of epithelium, lamina propria, and muscularis mucosae. The epithelial layer of the small intestinal musoca consists of simple columnar epithelium that contains many types of cells. Some of these are the following: Enetrocytes these help with the transport of substances from lumen of the intestine to the circulatory system, synthesis of the glycoprotein enzymes needed for terminal digestion and absorption. Goblet cells these are unicellular mucin also known as secreting glands. Paneth cells these are located at the bottom of the intestinal glands. Their main function is their secretion of granules which contain lysozyme this enzyme helps breakdown bacteria also known as phagocytosis. Paneth cells may have a role in regulating the microbial population in the small intestine. Enteroendocrine cells these are mostly found again in the lower parts of the intestinal gland known as the crypt. The main function of these cells is to release several hormones. The main one beings cholecystokinin, secretin and gastric inhibitory peptide these help increase pancreatic and gallbladder activity. Intermediate cells these are young enterocytes and goblet cell which are able to withstand cell division. Apart from the smooth muscle many other cells and vessels make up the intestine. The small intestine also contains submucosal artery and vein, lymphatic vessel, submucosal plexus, circular layer of smooth muscle, and myenteric plexus. All these tissues, cells, and vessel combine to make the small intestine wall. The smooth muscle in the control environment was able to obtain a steady frequency through out its 4 minute period with 15 waves per minute. The waves which were seen were the smooth muscle contracting and relaxing. The amplitude levels of the waves were both quite high showing strong contractions rate the reason for this was that the environment set was to ideal conditions where the muscle could perform its best. It had a max amplitude of 2.10 and min amplitude of 0.78 which shows that having ideal conditions the muscle is able to behave normally without any problems. The effect of oxygen lack of the smooth muscle cause the small intestine to increase the frequency, at 5 minutes no aerated the frequency had first dropped to 13 and after 15 minutes the frequency of contraction and relaxations had increased to 17 the reason or this being without oxygen the smooth muscles started to have spasms as it was unable to contract properly without the oxygen supply needed. Also the amplitude levels decreased quite quickly from 1.94 (max) and 0.47(min) at 5 minutes to 1.58(max) and 0.38 (min) at 15 minutes. The reason for this was that without oxygen the muscle was unable to make the energy needed for strong contractions as the peak is lowered as can be seen on the traces. This was detected by the pull on the string that was attached to the transducer; the pull was not as strong so this was recorded on the traces. So without oxygen the muscle cells are still able to make ATP but a small amount. Only about 2 ATP are produced per molecule of glucose in glycolys is. If there is no oxygen present, the Pyruvate produced in glycolysis undergoes fermentation to regenerate the NAD+ used in glycolysis. This is known as anaerobic respiration, anaerobic respiration generates only two ATPs, and lactic acid is produced. Most lactic acid diffuses out of the cell and into the bloodstream and is subsequently absorbed by the liver. Some of the lactic acid remains in the muscle fibers, where it contributes to muscle fatigue. Because both the liver and muscle fibers must convert the lactic acid back to pyruvic acid when oxygen becomes available, anaerobic respiration is said to produce oxygen debt The next part of the experiment was to test how the muscle activity differed when placed in glucose free solution. From this part of the test the frequency of muscle activity stayed consistent throughout the 15 minutes. The traces show consistent movement and also the amplitudes levels differed as at 5 minutes (1.34) the maximum amplitude was low then at 10 minutes (1.51) it wet higher and at 15 minutes (1.37) it decreased again to a similar figure which was at 5 minutes. By looking at this result the results are not as accurate as they should have been, meaning they may have been some kind of inaccuracy when following the method as without glucose, ATP can not be made and the amplitude of the waves should have been lower. ATP can be made from glucose which is stored in the carbohydrate glycogen. Through the metabolic process of glycogenolysis, glycogen is broken down to release glucose. ATP is then generated from glucose by cellular respiration. Also ATP can be produced from glucose and fatty acids obtained from the bloodstream. When energy requirements are high, glucose from glycogen stored in the liver and fatty acids from fat stored in adipose cells and the liver are released into the bloodstream. Glucose and fatty acids are then absorbed from the bloodstream by muscle cells. ATP is then generated from these energy-rich molecules by cellular respiration. Without glucose the frequecny should hve increased but the amplitudes levels should have decreased as there was not a sufficient energy source which could supply the muscle so it could contract and relax. The next part of the experiment consisted of placing the smooth muscle into a cooled solution of 4 Celsius from a change of 37 Celsius. There was not much change to the frequency but it did drop a little bit due to the muscle not being used to these environmental conditions. The amplitude differed from the control readings as they had decreased but were still quite high as they had the nutrients in the solutions which helped them to contract. If this experiment was left to carry on then there would be further change as the solution would gradually heat up to room temperature and this would mean that the smooth muscle activity would increase. Calcium plays a big part in all muscle contraction as well as smooth muscle contraction which is different as it does not contain troponin. In smooth muscles calcium ions enter from outside the cell. They then bind to an enzyme complex on myosin; this then breaks up ATP into ADP and then transfers the Pi directly into myosin. By doing this it allows the myosin to activate and from cross ridges with actin. When the calcium is pumped out of the cell, the Pi gets removed from myosin by an enzyme this allows the myosin to become inactive and the smooth muscle is able to relax. This process is also known as myosin regulated contraction. In the experiment where calcium free solution was added it affected the smooth muscle immensely as the frequency of contracting and relaxing dropped to 12. Also the amplitude levels came down as the contractions and relaxations levels were not strong the max being 0.95 and the minimum being 0.47 if this was left for a longer period of time the frequency levels may have dropped more. Without calcium entering the cell the smooth muscle is unable to do the process which is described above. While making the Ringer-Locke solution it is not only the calcium ions which are important to the smooth muscles. Some others are potassium chloride and sodium chloride, the reason these ions are needed because it helps to portray an environment such as the body with ideal conditions. If only distilled water was used it would mean the cells in the muscles would up take the water and blow up. So these ions are used so they are able to keep a concentration gradient and allow everything to work correctly as it would in the smooth muscles natural environment. The final environment was the change in pH levels. The results showed that the muscle had stopped functioning and there was no reading on the traces. This meant that there was no muscle contraction or relaxing. The reason for this was the muscle had broken down the reason for this muscle fatigue was that the low pH had affected the smooth muscle as it was unable to perform in this type of environment. Also as the low pH solution was there for a certain period of time the muscle was unable to remove it and therefore caused the muscle to breakdown. The low pH may have affected the sarcoplasmic reticulum which may lead to the interfere of the intercellular calcium concentrations, this can lead to long term physical muscle damage as muscle fibers are affected. While preparing the isolated smooth muscle many precautions are taken so the muscle can avoid excessive pH changes. One of these precautions which are taken is to make sure that before inserting the small intestine into the bath. The solution will need to be tested with pH indicator test strips which will give a fairly accurate reading of the solution which the smooth muscle will be placed. This is very important as if the pH is incorrect it will mean that the smooth muscle will not perform to its full potential meaning the results achieved will be inaccurate. To gain accurate results all solutions which are used will need to be checked to see if they are the correct pH by using the ph indicating strips. After this test the smooth muscle was unable to reach the control again as the muscle had broken down. If this experiment was done again at room temperature the results would differ as the performance of the muscle would decrease. This is because the optimum temperature inside the body is around 37 Celsius and this temperature allows the muscle to work at an optimum rate. The lower temperature will mean that muscle contraction will be slower as there will be an effect on enzyme reactions as the more heat there is the more kinetic energy there is this will mean that the muscle activity will be good. If acetylcholine was added to the solution bath of the smooth muscle the membrane potential would decrease and the frequency of waves would increase. The muscle will become more active, with an increase in tonic tension and the number of rhythmic contractions. The effect is mediated by enzymes which increases the intracellular Calcium concentration. Another substance which could have been added was adrenaline. Adrenaline allows blood to flow more easily to your muscles. This means that more oxygen is carried to your muscles by the extra blood, which allows your muscles to function at elevated levels. Adrenaline also facilitates the conversion of the bodys fuel source (glycogen) into its fuel (glucose). This carbohydrate gives energy to muscles, and a sudden burst of glucose also allows muscles to strengthen further. Skeletal and smooth muscle muscles differences in structure and function There are many differences between the two types of muscles the differences are stated below: Snmooth muscles Skeletal muscle A smooth muscle fiber has no T tubules, and the sarcoplasmic reticulum forms a loose network throughout the sarcoplasm. Are long cyrindrical cells that contain many nuclei Smooth muscle tissue has no myofibrils or sarcomeres They are striated this shows their precise alignments of their myofilaments. This tissue also has no striations and is called nonstriated muscle. Thick filaments consist of myosin as thin filaments consist mostly of actin. Thick filaments are scattered throughout the sarcoplasm of a smooth muscle cell Each independent cell is stimulated by a motor neurone. Adjacent smooth muscle cells are bound together at dense bodies, transmitting the contractile forces from cell to cell throughout the tissue. Connective endomysium seprates cell Function Differences Smooth muscles cells are an involuntary action and can work slower so they do not have muscle fatigue. Skeletal Muscle contains both Fast Slow Twitch muscle fibers, that allow for a faster reaction where needed, and the opposite is true for the Slow as well Smooth muscle lines your arteries and airways and serves to contract or relax to help control blood pressure. skeletal muscles function almost continuously to maintain your posture making one tiny adjustment after another to keep your body upright They are also present in the iris of the eye to control the size of the pupil in response to light. By the use of the radial and circular muscle. Skeletal muscle is also important for holding your bones in the correct position and prevents your joints from dislocating. Some skeletal muscles in your face are directly attached to your skin They line the GI tract to move foodthrough the intestines. This is done by peristalsis. Skeletal muscle generates heat as a by-product of muscle activity. This heat is vital for maintaining your normal body temperature.

Evolution and Education :: Science Teaching Argumentative Essays

Evolution and Education Whenever various debates have taken place in parts of the country regarding whether evolution should be taught in schools, I have always observed the situation with a degree of incredulousness; neither the parochial education I received in elementary and middle school nor the public education I received for high school ever attempted to dissuade us from learning about evolution, and while none of my classes ever taught evolution with as much depth as Ernst Mayr attempted to convey in What Evolution Is, both systems taught it as a fact – one that we took for granted. The debate on the use of the word "evolution" in the Georgia school system initially appeared to me to be a manifestation of more anti-evolution tendencies, although Superintendent Kathy Cox has not commented on the theory of evolution itself; "the unfortunate truth," stated Cox as her rationale, "is that 'evolution' has become a controversial buzzword that could prevent some from reading the proposed biology curriculum" (Gross A10). Whatever her own beliefs on the subject are, however, the elimin ation of the term "evolution" may provide cool comfort to the theory's detractors, but its overall effect is merely to hamper the student's understanding of what evolution entails. In place of "evolution," Georgia's proposed replacement is "biological changes over time"; it hopes to convey the meaning behind the word without using the word itself (Gross A10). Mayr's own definition seems to be rather similar when he states, "Evolution is change in the properties of populations of organisms over time," but a word expresses more than what a clipped dictionary definition can allow (Mayr 8). When "evolution" is used in daily parlance in a non-biological context, adaption is often an unspoken yet important component of it. If one speaks of "evolving as a person" or "evolving in his role as team captain," there is a sense that one is moving from a less-adapted state to becoming better suited for whatever it is one does. It implies that there is a development of certain qualities to be better suited for the environment an individual may find him- or herself in, not simply "changes over time" for the sake of change; while there is indeed a degree of randomness in how a species may evolve (or come to destruction, as the well-adapted dinosaurs did when a meteor struck and indelibly altered the environment), for the most part the changes are not entirely due to chance.

Understanding the Atkins Diet Essay -- Health Nutrition Diet Exercise

Understanding the Atkins Diet   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚     Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The Atkins diet is strictly regimented with a carbohydrate controlled and protein abundant regime. It is because of the promotion of protein consumption that the Atkins diet represents significant health risks. The diet requires strict adherence to a protein rich plan in order to achieve the desired results. The potential health problems resulting from this diet could be seveer simply because too much protein raises saturated fat levels. Such levels can lead to heart disease, osteoporosis, or kidney disease. The Atkins diet is examined below in relation to these health risks in order to evaluate the damage that it represents.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The Atkins diet proceeds in a set of phases. As guidance, the way these phases are presented indicates the potential for unhealthy consequences. The first phase of the Atkins diet allows the dieter to eat three meals a day. The dieter can à ¢Ã¢â€š ¬Ã…“eat liberally of combinations of fat and protein in the form of poultry, fish, shellfish, eggs and red meat, as well as pure, natural fat in the form of butter, mayonnaise, olive oil, safflower, sunflower and other vegetable oils...à ¢Ã¢â€š ¬ (Atkins.com). This is the only place in the diet description where animal protein consumption is addressed.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The second phase of the diet requires an à ¢Ã¢â€š ¬Ã…“incrementally increasing of the dieterà ¢Ã¢â€š ¬Ã¢â€ž ¢s carbohydrate intake... and this may be as low as 25 grams or as high as 50 grams if you are exceptionally activeà ¢Ã¢â€š ¬ (Atkins.com). However, it is still recommended that the dieter keep protein and fat as the mainstay of the nutritional regimen. This statement does not state whether the dieter should, for example, eat extra lean turkey or ... ... tailor his/her diet in order to lose weight while maintaining a healthy level of cholesterol as well as a healthy heart and kidneys. Such guidelines, however, are clearly not within the agenda of an à ¢Ã¢â€š ¬Ã…“all the meat you can eatà ¢Ã¢â€š ¬ dietary program.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Because there are no guidelines for protein in take, the dangers posed by over consumption of protein are ignored by the Atkins diet plan. The requirement encouraging over consumption of meat proteins clearly promotes known health risks. These health risks are widely recognized by the medical community. Avoidance of elevated levels of protein consumption is clearly an important part of a life style that is healthy for the heart, bones, and kidneys. It is more than unfortunate that the Atkins program promotes such a dangerously unbalanced diet. The healthy choice is to avoid the Atkins diet.

Cells And Cell Theory :: essays research papers

Cells and Cell Theory What advantages does small size give to a cell? Many cellular processes occur by diffusion, which is efficient over short distances, but less efficient over long distances. Since all materials going in and out of a cell must pass through the plasma membrane, the greater the surface area of this membrane, the faster a given quantity of molecules can pass through. Smaller cells have a much greater surface-to-volume ratio than larger cells and therefore can "feed" all areas of the cell in less time. What is "surface-to-volume ratio," and how does it affect cell size? The surface-to-volume ratio is a mathematical relationship between the volume of an object and the amount of surface area it has. This ratio often plays an important role in biological structures. Think of a cell as a sphere: The surface area of a sphere can be calculated by 4Ã ° r2 where r is the radius of the sphere. Volume of a sphere can be calculated by 4/3 Ã ° r3. An increase in r will increase the surface area by a power of two, but increase the volume by a power of three. This means that the volume will increase much faster than the surface area. This puts an upper limit on the size of a cell, because if the cell volume gets too big, there won't be enough membrane to transport the amount of food in and wastes out to support that large cell size. What is the difference between prokaryotic and eukaryotic cells? Prokaryotic cells are more simple: they are usually much smaller and don't have a nucleus or any other membrane-bound organelles. Bacteria are prokaryotes. Eukaryotic cells are much more complex, are usually larger, and have a nucleus and several other membrane-bound organelles that allow them to compartmentalize their functions. All multicellular plants and animals are eukaryotes. A helpful trick to remember is that "you" are a "eu"karyote. Are there any single-celled eukaryotes? Yes--yeast, for example. Yeast are single-celled organisms, but they do contain a membrane-bound nucleus, mitochondria, and other organelles. What are the advantages and disadvantages of prokaryotic compared to eukaryotic cells? Although prokaryotes may seem more primitive than eukaryotes, they are among the most successful species on our plant and comprise a very large percentage of the total mass of all living things on earth. Simple, small, and single-celled organisms can reproduce quickly and evolve quickly. Prokaryotes can generate millions of progeny in a short period of time.