Hemolysis of Horse Red Blood Cell Essay Example | Topics and Well Written Essays - 500 words

Hemolysis of Horse Red Blood Cell - Essay Example There are factors that contribute to the ability of the solute to pass through the cell membrane. One is the permeability of the cell membrane. Cell membrane is a lipid bilayer which does not allow ions and small hydrophilic molecules to freely pass the membrane (Kimball). Thus, for the sodium chloride, sodium sulfate and D-glucose solution to hemolyze the cell, a dilute solution should be used since this would increase the water concentration in the medium causing osmosis to occur. Another factor that determine membrane permeability is lipid solubility. Generally, low solubility in lipid would mean slower rate of entry to the cell (Crawford). Hydrophilic substances will pass through the membrane slowly. As shown in the results, D-glucose, sodium chloride and sodium sulfate were not able to cause hemolysis, Polarity and molecular size also affect the rate of entry of solute. Most polar molecules are hydrophilic; they cannot easily permeate the membrane (Cell Membrane, 2). Ethanol, propano-1-ol and glycerol, although polar, are small enough to pass through the membrane (Membrane Permeability). Notice that the time of hemolysis increases with molecular size with the glycerol having the longest time. Ammonium chloride was able to hemolyze the cell compared to other salts.

DNA Evidence Research Paper Example | Topics and Well Written Essays - 750 words

DNA Evidence - Research Paper Example The research on DNA evidence started showing significant improvement by the 20th century. DNA evidence became widespread and it became a problem-solving tool for immigration disputes, refining the assay, resolving specimen identity, detecting genetic differences and identifying criminals; thus, the need for DNA identity testing became significant. Historically, DNA evidence began in the forensic field when ABO blood group was used as a system in providing evidence of crime issues. Later, the paternity identification that based on serum protein variation became commonly used. However, it was not until when Jeffrey became a pioneer of DNA based identity testing. DNA evidence became common in federal courts, and the first DNA evidence was carried out in the court case of Andrews Vs., Florida in 1988 (Newton, 2008). Many states started adopting DNA evidence in order to identify crime issues as a way of maintaining criminal justice. DNA evidence started evolving as an effective technique of providing proof over crimes issues. It is used up to present in many areas including clinical applications for testing identity, and also solving paternity issues in case of child denial or resolving specimen identity; thus determining the origin of mishandled specimens. The major sources of DNA evidence include semen, bone, blood, skin cells, hair, teeth, urine, tissue, saliva, feces, and vomit. First, blood is one of the main sources of DNA evidence. The substrate in which bloodstain is found can determine the DNA testing; thus providing effective evidence in case of homicide or any other crimes issues. Blood contains some substances that may hamper successful DNA testing process; thus, these substances can be removed through purification methods (Parks, 2010). DNA profiling is the only way through which scientists can be able to stain of a given blood mixture. Through DNA testing, one can be able to determine in case specimen are from the same or different sexes. Semen is anot her source of DNA testing. The semen stains can be analyzed and examined as well as tested through conventional methods in order to provide the required evidence. Sperm cell staining can help in determining in case the stain is the outcome of vaginal drainage. This will enable scientists to determine the rape cases through DNA analysis of semen stains. Moreover, body tissues, saliva and hair roots are among the major sources of DNA evidence. DNA strand isolation from body tissues can help in achieving the intended goals of DNA evidence. DNA survival can be found in teeth or dense bones. The remains of body tissues that have been scattered by either gunshot or trauma can adhere to the bullet; thus, they can sometimes yield sufficient DNA testing. There are some treated tissues by use of the chemical treatment known as formaldehyde and embalming. DNA testing can be successful in both tissues. For instance, a body of a person killed and buried for many years can still yield better resu lts when used in carrying out DNA evidence. Hair roots can be the legitimate source of DNA evidence, but they are not effective in regular forensic use. Saliva can be taken from penile marks, bite marks,  bottles and cigarette butts found in the crime scene. Despite the exciting promise of DNA technology, DNA evidence poses some problems.

Global Warming Essay Example for Free

Global Warming Essay Every day we go about our own business. Many of us never take the time to look around and see how we are affecting our earth’s atmosphere. Everywhere you look today you are bound to see some factory or machinery polluting our air. Just think how many times you have seen those large semi trucks or big fossil fuel factories emitting thick dark smoke into the atmosphere. We need to come to reality and realize that all that polluting we have been doing over the last half-century is finally catching up to us. It is very easy to detect through scientific research that our earth’s climate is changing, Time magazine reports in its 2004 issue that the earth’s average temperature is increasing at a steady rate. Yes, we all have heard the term â€Å"global warming†, however many people don’t know in depth what global warming is, or how our actions will affect our earth if we don’t respond to the issue. If we can educate ourselves on what global warming is and how it will affect us in the near and far future, we can then begin to change our old habits of polluting and create new habits and goals to living in a much healthier and cleaner environment. During the earliest times, the life-styles of our ancestors were very simple. The air they breathed was clean. The streams were clear and free of harmful organisms. They used natural fertilizers for their agricultural crops. The surroundings were free of household throwaways. Today, there has been a tremendous growth in science and technology. Such advances have brought about changes in terms of new products, improved equipment, and more effective methodologies. Unfortunately, this same technology which made life easier for us produced wastes which are now affecting the quality of our surrounding air, water, and land. Factories and motor vehicles send tons of pollutants into our air. Excessive air pollution poses a danger to our health and environment. It can likewise cause stunted growth and even death to our plants. Out streams are polluted by discharges from industrial plants that use chemicals. Garbage and sink wastes are carelessly thrown in our surroundings. Synthetic fertilizers and insecticides pollute our land and farm products. At the same time, the burning of fossil fuels, particularly coal and oil, produces sulfur dioxide and nitrogen oxides which are hazardous to the atmosphere. Findings show that a single smokestack may produce as much as 500 tons of sulfur dioxide a day. When these gases combine with oxygen and moisture, sulfuric acid and nitric acid is formed. The rain will carry the acids to the ground (acid rain) which may cause the depletion of calcium and magnesium in the soil, elements needed by plants for the formation of chlorophyll and wood, or it may cause the release of aluminum in the soil, which are poisonous and can kill the roots of trees. How can we take care of our environment? We must undertake measures to preserve our resources and minimize utilization of energy before it’s too late. Our fight against pollution is an initial step toward conserving our environmental resources and energy. We must all join hands for this common goal. Furthermore, of all issues affecting humanity, climate change is the most pervasive and truly global, posing a very real and serious threat to our environment. Climate change is the alteration of the pattern of global climate that may be due to human activity that alters the composition of the atmosphere.

Safeguarding the Welfare and Innocence of a Child

Safeguarding the Welfare and Innocence of a Child Childhood experiences differ from person to person in many ways. One’s personal experience of childhood is likely to affect their understanding of childhood and their ideal vision of childhood. When I reminisce about childhood, the ideal vision of children frolicking around the park, having fun and carefree days comes to mind. As described by Rousseau, childhood is a brief period of sanctuary before encountering the perils and hardships of adulthood. This line by Rousseau: Why fill with bitterness the fleeting early days of childhood, days which will no more return for them than for you? encapsulates my ideal vision of childhood, a time of pure innocence that will never be recaptured and should be the best time of our lives (Hutchison Charlesworth 2000; Wood 2003). Brought up in Singapore as the youngest child in a family of four, my childhood experience was built upon an â€Å"Asian construction of childhood† with beliefs and ideas of Asian cultural influence. However , being the youngest child made me the perpetual â€Å"baby† of the family, with constant protection and showering of care. Coupled with the media’s constant representation of the innocent child through various movies and images, my view of childhood is inevitably skewed towards this image. The image of innocence recognizes a child’s vulnerability and immaturity, reflecting the need to provide care and protection in order to preserve the physical and spiritual purity of the child. James Prout (1990) recognized that while childhood innocence is a socially constructed phenomenon, biological immaturity is a fact of childhood. Therefore in this image, childhood is viewed separately from adulthood, with the responsibility of the young and innocent firmly in the hands of adults. It is further supported by the code of ethics in the UN Convention on the Rights of the Child (CRC), where adults are in a position of power, with the expectation of making decisions in the best interests of the child due to their innocence and perceived incapability of making the right decisions. In my experience of childhood, my brother and I were kept on constant adult supervision without the need or option to make any decisions. Everything was taken care of by Linda, our domestic worker fr om the Philippines and she was tasked to follow instructions and daily routines set out for us by my parents. Rousseau noted that children are born into an original natural state of essential goodness. However, their closeness with nature and natural goodness is being threatened or degraded by culture. In my infant years, protecting us from the ‘corruption’ of society was exactly what my parents wanted by limiting our exposure to sources of corruption such as violence in music, television and games. Postman (1983) highlighted a shift away from child innocence due to the myriad of media universally available to children. In recent years, the proliferation of technology and wider exposure to the Internet further deepened my view of the need to protect a child’s innocence. With more children playing games on internet-ready devices like the iPads, the ‘corruption’ of society slowly creeping into a child’s environment even without stepping out of h ome. While the image of innocence seem ideal at the infant stage to protect their innocence, upon further consideration, critics highlighted that continual treatment of a child in this view may hamper their development. . This is where I feel the limiting of experience and of opportunity may be critical and damaging for the child. As highlighted by Woodrow (1999), maintaining this focus as a child matures will deny them agency and inhibits the potential development of skills required to handle challenges in the future. With adults perceived as having power and responsibility over and for children, this raises another debatable point of whether they are always acting in the best interest of the child. In this construct of childhood innocence, Hutchison and Charlesworth (2000) argue that childhood becomes sentimentalized, while Docket (1998) feels that this nostalgic view stops us taking children seriously. Upon reflecting on my initial understanding and experience of the image of innocence, perhaps childhood consists of transitional phases consisting of multiple definitional perspectives. A transition into the frame of child development is a solution to progressively give a child more agency and Piaget’s view on childhood encapsulates it. Piaget noted the conception of childhood as certain transition stages of their lives at about 18 months, 7 years and 11 or 12 years, where a child will develop from immaturity to rationality, increasing their ability to understand their surroundings and have new capabilities to undertake certain tasks. The child is now viewed in the image of an embryo adult, seen as ‘human becomings’ rather than ‘human beings’ in preparation for the future (Hutchison Charlesworth 2000). At the early stages, as the child is positioned as less knowing, it is the responsibility of parents to use their own knowledge or resources to groom and nurture the abilities of their children at home. Upon attending school, the child is subjected to a politically influenced curriculum designed by teachers, which pushes them to achieve results and judged on standardized tests (Woodrow 1999). In relating my childhood experience in this perspective, grooming a child to undertake certain tasks is a challenge and very much depends on whether the agentic child is willing to accept it. At the age of 7, I was enrolled for swimming lessons but strongly refused to do so due to my immaturity and lack of understanding about it. However, after carefully explaining to me the importance of swimming as a life skill 2 years later, the increase in rationality and readiness led me to acquire new capabilities. In other instances, I was coerced to accompany my older brother in attending other courses beyond my will, and such scenarios depict images of a tyrannical adult as opposed to loving guides. Therefore, the adult must take special considerat ion when faced with such situations, as it may result in the poor emotional connection between children and adults as noted by Hoffman (2000) within this construct of childhood. In addition to this, the adult will have to constantly ensure a child’s needs for emotional stability, security, confidence, self-esteem are met. These images are never stable or unitary and their meanings are contestable. It is easy to over-simplify and homogenize the idea of childhood, and the children who go through that phase of life, ignoring cultural influence that children experience which differentially produce conceptions of childhood (Woodrow 1999). Everyone’s childhood is a unique phase of life. The only commonality is how one’s childhood is a determining factor of how their life shapes out to be, and the way it will influence childhood for their kids. To a child, what matters most is parents, as they will learn everything from them. The underlying idea of childhood is complex, and the role that adults play is rather confusing. The UN CRC states that all children have a right to speak freely and to be listened to by adults over decisions that affect them. While we recognize that a child has the right to be heard, and that they should have a say in their plans for the future, just to how much extent should they be given that freedom? By putting power and responsibility in the hands of children, does this confuse the role of adults and their responsibilities of shaping childhood? How will this affect an adult’s role in making decisions in the best interest of the child? On the topic of best interest of a child, an adult should act in the best interest of the child, but what’s best for the child may not exactly be in the same view in the eyes of the child. Also, an adult may not always act in the best interest of the child but rather, the most convenient option. How then are we going to police what’s right and what’s wrong. There can be guidelines in place but whether it’s enforced in the compounds of a home is something beyond our control. At the end of the day, there’s no single correct way of raising a child, as there are way too many variables to consider. Each child is different, each parents has their own views on how to raise a child. We are unclear who is in charge of childhood: teachers, parents, politicians, or children themselves? Alongside listening to children, the real question we need to be asking, as parents, educators, employers and politicians, is: have we created a society that has destroyed the childhood we want for our children?

The Symbolic Role of Birds in Kate Chopins The Awakening Essay

The Symbolic Role of Birds in Kate Chopin's The Awakening The Awakening by Kate Chopin is a truly enlightening novel about a young woman who begins to really live her life for herself, breaking out of the various barriers of society and family. Chopin uses symbolism as an excellent tool to slip her ideas to readers, causing them to think, giving readers a glimpse into the life of this young woman at a time when women were harnessed by many restraints. The birds that appear throughout the novel are the most intriguing symbols; they are used many different ways, to mean many different things, and to portray various emotions and situations. As the novel begins, Chopin likens Edna to a bird in a gilded cage. Edna is not free, but that is okay because she has not yet begun to see what life has to offer; she has not yet begun to awaken. Through Edna's desire for Robert, she begins to realize that she is like the bird in the cage, not wanting for anything materially but still trapped. Edna cannot fly away to freedom; she is tied by social constraints and especially by he...

Stories and a White Man: An Open Letter to My Navaho Students :: Essays Papers

Stories and a White Man: An Open Letter to My Navaho Students Some of your Elders encourage you to leave the university and return to the reservation. They tell you that the university is not for you. I respect your Elders because I understand that they wish the best for you, but I cannot agree with them. Come here. Let's share a place together, here on this page, as real as Second Mesa where the wind makes its own stories and all of us must listen to the language of Crow in order to find our way home. Right now let's share a place where we wait trustingly and where storytellers are never victims because they have their stories to protect them. Let our moment together be a home of stories, and let us agree to live in a world where such a place as this one exists. My Uncle Mace was Native American. I'm not sure what nation he came from, but I understand it was one of those "civilized" tribes because unlike the Apache they did not tell jokes that ended with "White men are stupid." So White men called them "civilized." Uncle Mace told me stories. He would start with, "Now, everything I tell you is true." Then he would tell me something confusing and crazy and wonderful, something about bears or ants or giants. Some of his favorite stories were about a race of great ones who were men but did things men could not do. Anyway, I believed they were true stories, and I have to admit that I probably still do. There's a place in me where Uncle Mace still lives. My great grandfather used to take me along when he went to visit sick animals. He was a homemade veterinarian, and the farmers loved him because they never got around to paying him. His specialty was to cure bloated cattle. He would walk up beside the animal and stick a knife into its belly. Anyway, he always drank whisky as we drove along, and he always made up songs. He had a voice filtered through gravel and tar, but the songs were stories, and I believed them like the stories of my Uncle Mace. One song went something like this: When I was a young man I had long green pants. I wore them all day but they were full of ants. Sometimes at night I would wonder how he was able to get along with his green-ant pants.

American films Essay

be at work making sure he works his ass off to get us where we are now. Although I don’t see him most of the time during my childhood, and he missed almost every one of my birthday’s I can never be mad at him for it. Something I most admire my father for is the fact he gave up his family and life he had back in the islands to support his daughter and pregnant wife, which changed all our lives. As soon as he joined the military he flew us 2 kids and my mother out to America to see our new house in Hawaii. The day we all came to America was the day we left behind the poverty and worries back in Samoa. Since that day, I have always respected my father. Even though I sometimes abhor is actions towards discipline, I constantly think back to the days we had it rough and who it was that became our hero from there on out. Without his decisions on coming to America and toward his responsibilities, I wouldn’t have had hope in finding a future for myself back in the islands . Because of my father’s life changing choices, I am living a life of a lifetime; a humble lifestyle.