Cockroaches and Hemolymph Concentration in the Body Essay Example for Free

Cockroaches and Hemolymph Concentration in the Body Essay This lab was conducted to determine the concentration of hemolymph in the body of a cockroach. It was done by making serial dilutions to make a standard graph by injecting a dye into a cockroach and determining the concentration at different times with the use of a spectrophotometer to find the optical density which is measured in absorbance. Results showed that the concentration was not within the pre-experiment research range. Introduction: Cockroaches as well as all other insects have an open circulatory system. Unlike humans who have a closed circulatory system with arteries and veins, insects do not have any arteries or veins. They have a body of internal fluids and they use diffusion to transfer nutrients and oxygen across their bodies. This process of diffusion is only made possible because of their small bodies. In practical terms, cockroaches are cheaper than vertebrates, and since they are neither furry nor cuddly their use does not anger the animal-rights enthusiasts. In terms of economics and public health, we need to know everything we can about insects because of their enormous impact on humans as crop pests, carriers of disease, pollinators, etc. But they also have a fascination in their own right. For instance, they represent the only other major group of animals that, with the higher vertebrates, have successfully conquered the terrestrial habitat. Insects and mammals have a vastly different evolutionary heritage: evolution has had to work with very different basic body plans to produce two highly successful terrestrial organism (Smith 119-139). Insects regulate their hemolymph volume by a variety of mechanisms including hormonal and metabolic factors. In an aquatic environment, insects must continuously excrete water to compensate for water uptake, whereas in a hot, dry terrestrial environment the insect must conserve water – in both these instances, the volume of the hemolymph is regulated to prevent excessive water gain or loss. In any given insect species, the volume of the hemolymph at any particular time during the life cycle will tend to be fairly constant. However, stressing the insect, for example by exposure to very high temperatures or by starvation, will result in changes in the hemolymph volume. The Internal fluid in the insect’s body is termed Hemolymph it contains both blood and other fluids. The hemolymph is used to transfer nutrients, ions, and waste to different organs in the body. It also is used to defend against microorganisms that might attack the insect’s body. The Hemocoel houses the hemolymph where all the organs are located. My hypothesis was that the hemolymph in the insect’s body was about 20-40% of the body mass. Materials and Methods: In order to find the cockroachs hemolymph volume, a small quantity of concentrated dye was injected which helped one to find how much the dye was diluted. A spectrophotometer was used to find the dye concentration needed in the cockroach. A spectrophotometer worked because dyes and other chemicals absorb light of characteristic wavelengths, and the amount of absorption depended on the concentration of the chemical. Knowing the original concentration and the final concentration it was to calculate what volume (the hemolymph volume) would have been necessary to dilute the dye that much. A range of volumes was chosen extending from below to above the probable values for hemolymph volume; you can produce a standard curve for optical density of solution on which you can read hemolymph volume directly. One advantage of this was that any errors in the procedure with the cockroach were likely to be similar to those for determining the standard curve, and they therefore canceled each other out. We started off by making serial solutions to make a standard curve for dye concentrations. We put 100, 200, 300 and 400 ul of a Ringer solution mixed with 10 ul of dye. We then put 5 ul of the first tubes into tubes that had 2500 ul of Ringer solution using a pippete. We then measured the optical density (Absorbance) of our serial dilutions with a spectrophotometer at 522 nm. Then we graphed the data, we made it linear by doing 1/OD to get an equation for the line. The next thing we did is we anesthetized our cockroaches with CO2 and we weighed our cockroaches. We then injected 10 ul of dye into the abdomen of the insect. We waited until the dye was mixed in the hemolymph evenly then we took samples at different points in time at 5, 15 and 20 min in time. We injected next to the armpit of the leg and used cold capillaries to obtain our samples. We then used the spectrophotometer to measure the OD of the samples mixed with 2500 ul of ringer solution at the different time periods. We then plotted the data and obtained the  equation. Then we plugged the reciprocal of y intercept to the equation and found the x value which equals the volume. This is a graph illustration of time(seconds) Versus optical density Discussion: After the lab was done, my original hypothesis was rejected. I predicted that the cockroach would have 20-40% hemolymph concentration. This turned out to be incorrect. Our cockroach had a percentage of approximately 15%. The result is not far from the 20% range I predicted nevertheless, not specifically accurate at all. According to my prior research, an average hemolypmh is around 25 percent and makes up about 20% of the body weigh of the cockroach. According to this research, my hypothesis was correct about the concentration of hemolyph (Czpla 171-181) There is always some variation within experiments so; something that was done during the experiment possibly could have gone wrong. The variation could have been due to the lack of following the specific time or variables. It was most likely due to a human error, which my group possible overlooked. There could have been mishandling of the specialized equipment such as the pipette or the spectrometer. It is really easy to mishandle the pipet and can result in the wrong amounts of water used for the experiment. This could affect the optical density and result in excess data. Some of the equipment was old and not always properly and fully functional. In a good preparation, the three data points for optical density (OD) will lie approximately on an exponentially declining curve (dye excretion rate may be a function of dye concentration). The extrapolation back to zero time should therefore follow this curve. Often, however, the first point will be noticeably high or low compared to the trend of the later points. This is probably due to poor mixing, either because of poor circulation, or poor injection where the dye sometimes appears to be trapped close to the point of injection. In this case, the best that can be done is to extrapolate from the later points, which, since there are only two points, will have to be a linear extrapolation. My results were in an exponentially declining curve so,I can not relate any error due to the mixing. A factor, which should be discussed because it could’ve provided some potential errors, is the removal of hemolymph from the cockroach during the 30-minute sampling period. This could have reduced the hemolymph volume. The error becomes progressively larger as the 5  µl samples are removed. If mixing is incomplete, the OD may apparently increase. Another possible source of error is the distribution of the dye, that is, how long does it take for the dye to be distributed uniformly throughout the hemolymph? This could have been a potential error, it is something I remember happening during the experiment though I did not realize the implications of it at the time. As time goes by, the Optical Density in the samples taken goes down in value. That shows that the dye within the body of the cockroach is getting transferred outside of the body of the insect. The Hemolymph concentration in this cockroach is . 2/1. 3= 15% that is not within the range of the concentration that should be which is within the range of 20-40%. There might have been an error in the spectrophotometer or maybe the dye didn’t spread well enough within the body, which would ruin our results. The sex of the cockroach might also play a role on the concentration of Hemolymph. For the future, if I were to carry out the same experiment I would stick to my prediction but would be more careful in carrying out the experiment. I would make sure I carried out the experiment exactly right.

Essay on Camus’ The Stranger (The Outsider): Meursault as Metaphysical

Meursault as Metaphysical Rebel in The Stranger (The Outsider)  Ã‚     Ã‚   The Stranger by Albert Camus was published in 1942. The setting of the novel is Algiers where Camus spent his youth in poverty. In many ways the main character, Meursault, is a typical Algerian youth. Like them, and like Camus himself, Meursault was in love with the sun and the sea. His life is devoted to appreciating physical sensations. He seems so devoid of emotion. Something in Meursault's character has appealed primarily to readers since the book's publication. Is he an absurd anti-hero? Is he a moral monster? Is he a rebel against a conventional morality? Critics and readers alike have disputed a variety of approaches to Meursault. I believe he is the embryo of Camus' metaphysical rebel as articulated in the philosophical essay, The Rebel. He is the man who says by his actions, "I will go this far, but no farther." In order to understand Meursault's rebellion we must first understand the nature of his personality as portrayed by Camus. The novel begins with the laconic assertion "Mother died today. Or, maybe, yesterday; I can't be sure." His mother's death briefly interrupts the pleasant flow of Meursault's life, a life devoted to appreciating sensation. He loves the feel of a crisp towel in the washroom. He enjoys eating, drinking, and smoking cigarettes. He loves to watch the sea and the sky. Swimming and making love to pretty girls like Marie are his favorite pastimes, so much so that an offer of a job promotion in Paris does not in the least appeal to him. When something bores him or distresses him he simply goes to sleep, as he does on the bus to his mother's funeral and even in jail. He is a detached observer of life. Symbolic of this quality... ... noble act. Even we might be able to do that.    BIBLIOGRAPHY Bree, Germaine. Camus. New York: Harcourt Brace, 1964. Camus, Albert. The Rebel. New York: Vintage Books, 1954 Champigny, Robert. A Pagan Hero. Philadelphia: University of Pennsylvania Press, 1969. Cruickshank, John. Albert Camus and the Literature of Revolt. New York: Oxford University Press, 1960. King. Adele. Camus. New York: Capricorn Books, 1971. Lottman, Herbert R. Albert Camus: A Biography. New York: George Braziller Inc. 1980. Masters, Brian. Camus: A Study. London: Heinemann, 1974. McCarthy, Patrick. Camus: A Critical Study of his Life and Works. London: Hamish Hamilton, 1982. O'Brien, Conor Cruise. Albert Camus of Europe and Asia. New York: Viking Press, 1970. Quillot, Roger. The Sea and Prisons. University of Alabama: University of Alabama Press, 1970   

The Importance of Marriage in Pride and Prejudice

Set in late 18th Century England, Pride and Prejudice depicts the search of women for the ‘inevitable' husband and of a male dominant society, within which no woman can be considered truly successful without the assistance of a man of ‘good fortune'. Austen addresses the common ideals of society throughout Pride and Prejudice, such as the monetary values of marriage and the need of a woman to find security for herself and her future children. The opening line of the novel reads ‘It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife. Austen not only uses this line to introduce a key theme of the novel, but also hints at the underlining themes of the novel and at the irony and satire due to follow. This is also a use of proleptic irony, Elizabeth is considered as a woman who seeks true love, rather than a marriage based on the fortune of the male; however, upon seeing Pemberley Austen presents Elizabeth as considering money for the first time, the sheer size of the house impresses her and thus she cannot disregard its appeal. During both the 18th and 19th centuries marriage was regarded both a social and biological destiny for woman across all the classes. Austen portrays this belief through Charlotte Lucas whom after gaining some composure considers â€Å"Without thinking highly either of men or of matrimony, marriage had always been her object; it was the only honourable provision for a well-educated young woman of small fortune, and however uncertain of giving happiness, must be their pleasantest preservative from want† (Austen,J. 1853: 22). This amplifies the importance of the rejection of marriage by Elizabeth to Mr Collins, whom by the opinions of society at the time, the natural reaction for a woman in her situation would have been to accept. For she cannot afford to be overly choosy when it comes to marriage – earlier on in the novel Austen describes Mr Bennett cautiously going through the accounts of the estate, in which we are indirectly informed that the accounts are not looking positive. This marriage rejection is also relevant to the life of Austen, who we have learnt rejected a marriage proposal after overnight mentation. Marriage during the 18th and 19th centuries would be a whole family affair, and thus the effects of a marriage proposal or rejection would be felt throughout the generations. Families would look to ally themselves with other families of similar rank, hence marriage between cousins was common practice. This would ensure that both wealth and property would remain within the same family for generations via entailment, thus explaining the disappointment of Mrs Bennett upon finding out of the rejection of marriage between Elizabeth and Mr Collins. Moving to their husbands' establishment would often be the only possible freedom available to girls, though not to be confused in any way with independence, which girls at the time would be lacking. This was another reason that leading families would ally with one another, or often marry within – a family would never wish for their daughter(s) to be associated with a family of lower social value, and thus a smaller estate, or require any future financial support from them – this dependence would grow increasingly expensive and as Austen presents the Bennetts as a family with some financial troubles there is no question as to why she identifies the need for the daughters to be married off. With marriage being the ultimate goal for any young girl within Pride and Prejudice, events leading up to any such event are considered significant. For example, any balls or dances and the partnerships which develop within these; any ‘chance' encounters, such as meetings within town. Marriage would be a key theme of conversation within social circles of girls beyond puberty, the legal age for marriage was 16 (or the age of ‘coming out'), it was much desired by the age of 18 and would threaten to be beyond availability for girls of 20 or older. Girls would worry about being considered an ‘old maid' beyond the age of 20 which explains the desire that Austen presents Charlotte to have in ‘catching' Mr Collins and the warning that Mr Collins gives Elizabeth, who upon rejection of Mr Collins' proposal is already 21. Though the legal age of marriage in England was 16, due to the Marriage Act of 1853, it is assumed that Lydia and Wickham elope to Gretna Green in order to complete their marriage, rather than be living in sin and thus have society look down on them as an unlawfully acquainted couple – in Scotland was not necessary to live in each others' company for a minimum of 3 weeks prior to marriage like it was in England, thus allowing for an instant marriage. Much like the partnership between Darcy and Elizabeth we are made to wait for them to be partners in dance, it is a recurring theme throughout the novel that the longer the time period before the first dance between a couple the longer the time period will also be before they are romantically interested in one another. â€Å"To be fond of dancing was a certain step towards falling in love† (Austen, J. 1853: 6), thus the reluctance of Darcy to participate in dancing earlier on in the novel marks his limited social availability. However he becomes more available to Elizabeth later on in the novel as Austen presents him as someone whom is interested in being acquainted with Elizabeth and thus he asks her to dance, though even the act of doing this is portrayed as being difficult for him to achieve. The partnership between Elizabeth and Darcy is a stark contrast to that of Jane and Bingley, which Austen develops from the introduction of the two parties – they dance at the first meeting of one another and are thus romantically involved with one another from this point. Mr Bennett is presented by Austen as a man who is interested in the happiness of his daughters, though namely Lizzy, he is rarely phased by the actions of Lydia, Jane or Mrs Bennett however upon learning of Mr Collins' proposal states â€Å"Your mother will never see you again if you do not marry Mr. Collins†¦ And I will never see you again if you do. † (Austen, J. 853: 64) Austen uses this conversation as a means of demonstrating the understanding and respect that exists between both Lizzy and her father, with Mrs Bennett already having come to the conclusion that Mr Bennett would insist on Lizzy marrying Mr Collins, however in this scene Austen also manages to portray a subtle humour – we read earlier on in the novel of Mrs Bennett's ‘nerves' and this is just another example of Mr Bennett knowing how to vex her, with the reader remembering earlier on in the book when Mr Bennett states â€Å"You mistake me, my dear. I have a high respect for your nerves. They are my old friends. I have heard you mention them with consideration these last twenty years at least. † (Austen, J. 1853: 4). With Lizzy being truly her father's daughter she knows that she will have the support of the parent who means the most to her, or at least the parent whom she is more interested in pleasing. Mr Bennett plays a pivotal role in the marriage of Lizzy, he has the final say on whether or not she marries Darcy, throughout the novel Austen doesn't portray any form of interaction between Mr Bennett and any of his other daughters or their respective partners regarding the issue of marriage. Though this may be due to Elizabeth's importance to the novel, we assume that this is also due to the value of her partnership with Darcy and how this is used to show her romantic development throughout the novel. Austen presents Elizabeth as a character who goes through the typically romantic process of falling in love with someone – both Elizabeth and Darcy must overcome a variety of obstacles in order for their love to Blossom, their story starts with bad first impressions of one another, with Lizzy assuming Darcy to be a pompous, arrogant man and Darcy being blinded by Lizzy's social inferiority. Austen wrote this novel based in an era within which girls being forced in to marriages for financial reasons was coming to an end and though monetary reasons were still considered a valid reason for marriage, or at least one for which marriage would be considered acceptable by one's family, people were also marrying due to love for one another. Lizzy represents the new era within which love is the main reason for marriage or courtship, we recognise this as Lizzy is aware of Darcy's fortune from an early stage of the novel, however she dismisses him due to his arrogant behaviour – if Lizzy was only interested in his wealth, or if this were the reason of her interest in Darcy then Austen would have ensured that she, like her other sisters, flaunted herself in front of a male of such high social value. Austen represents marriage for the ‘wrong' reasons with the marriage between Mr and Mrs Bennett. With Mr Bennett having previously married Mrs Bennett for her youth and good looks, with Mrs Bennett declaring â€Å"I certainly have had my share of beauty, but I do not pretend to be anything extraordinary now. â€Å", he now finds his only happiness through private study or mocking his wife, referring to her ‘nerves' as his ‘old friends', with his witty humour being too complex for her to understand and thus not being able to tell when he is using sarcasm. This sarcasm is a trait which Lizzy shares, for example in Chapter 28 when describing Miss De Bourgh, Lizzy states â€Å"She looks sickly and cross. Yes, she will do for him very well. She will make him a very proper wife. † This use of juxtaposition is rife in Austen's work and is often used for comic effect. Austen uses the juxtaposed relationship between Lizzy and Darcy to present us with an example of marrying for love, rather than superficial reasons which are evident throughout the novel. Examples such as Mr Collins and Charlotte Lucas, or Lydia and Wickham are doomed to fail, or at least to result in the severe unhappiness of the parties involved due to the basis of the relationships being built on financial security or social status. Lizzy and Darcy represent a marriage which ignores the superficial values and focuses on true love, Austen shows us as the reader that this is the only way to have a truly successful and happy marriage to one another and she manages to gain our agreement by portraying the other possible choices throughout the novel.

A Case Study of T.C. Aspergers Syndrome Essay - 1943 Words

Case History: T.C. is a 13 year old, 2 month old girl in the seventh grade. T.C. lives with her parents and she is the oldest of three children. T.C.’s prenatal and birth history was unremarkable. T.C. was normal developing until 18 months old. By 18 months old it was apparent that T.C. was delayed in speech. In addition, she walked on her toes, did not make eye contact with others, had a terrible fear of loud sounds, cried frequently, and was a poor sleeper. She was evaluated before her second birthday and was diagnosed with Asperger’s Syndrome or related pervasion developmental disorders and has profound difficulty with social interaction. She has received speech therapy, with an emphasis on social skills training, intense therapeutic†¦show more content†¦82), and it is important to use a happy tone of voice. After role playing with her SLP with different types of voice tones, T.C. practiced reading a passage slowly using proper intonation, stretching and pausing. After reading smoothly, T.C. was asked to state the most important detail using the proper intonation and facial expression when responding. Corrective feedback was used to correct the student when she did not use the appropriate tone and intonation when reading the passage. In addition, the SLP modeled and had T.C. communicate different messages using the appropriate volume for suitable situations. For example, T.C. was asked to speak in the appropriate tone when there is no one else speaking (quiet voice), i.e. a quiet classroom; to speak in the appropriate tone where there are others talking (louder voice), i.e. in the schoolyard during recess; and when you are standing right next to a listener (quiet voice), i.e. when speaking to one friend. The SLP and T.C. role played standing far away from one another to demonstrate using the appropriate tone. T.C. was verbally praised when she demonstrated the tone of voice to keep her motivated. Session #2: The SLP went over different scenarios with T.C. when retelling a story with salient details and suggested activities when calling a friend on the telephone. In one scenario, the SLP and T.C. role played was calling a friend to make plans that day. The SLP was the friend and T.C. was herself. It