What causes Anorexia
What causes Anorexia? For people with anorexia, it really is true that one can never be too thin. Despite being dangerously underweight, anorexics see a fat person when they look in the mirror. What they don't see is the tremendous physical and emotional damage that self-starvation inflicts, so they continue to diet, fast, purge, and over-exercise. While people with anorexia often deny having a problem, the truth is that anorexia is a serious and potentially deadly eating disorder. Fortunately, recovery is possible. With proper treatment and support, you or someone you care about can break anorexia's self-destructive pattern and regain your health and happiness. What exactly is anorexia nervosa? An example; (Maria's Story) Seventeen-year-old Maria has been on one diet or another since she was in junior high. She recently lost 10 pounds from an already slender frame after becoming a strict vegetarian. Her parents are concerned about the weight loss, but Maria insists that she's just under stress at school. Meanwhile, her vegetarian diet is becoming stricter by the day. Maria obsessively counts calories, measures food portions, and weighs herself at least twice a day. She refuses to eat at restaurants, in the school cafeteria, or anywhere else in public, and she lives on salad dressed with vinegar, rice cakes, and sugar-free Jell-O. Maria also has a large stash of
Discuss The Significance Of Normal And Abnormal Mitosis And Meiosis In The Lifecycle Of Humans
Discuss The Significance Of Normal And Abnormal Mitosis And Meiosis In The Lifecycle Of Humans. Introduction: Mitosis is a type of cell division. The nucleus divides once and produces two identical nuclei. The new daughter cells are genetically identical both to each other and the parent cells. The only source of genetic variation in the cells is via mutations. Mitosis is used for growth and repair. Some tissues must be repaired often for example, the lining of the gut, white blood cells, skin. The skin cell lifespan is only a few days. The same chromosome number is retained from generation to generation. The duplication of a chromosome is followed by a nuclear and cell division. Nuclear division its self is a continuous process, but for ease of description, four main stages are recognised. The four stages are known as Prophase, Metaphase, Anaphase and Telophase. When a cell is preparing to divide, it is said to be in Interphase. At this stage the cell forms new cell organelles to supply the daughter cells. The DNA replicates so the there is sufficient DNA for the two daughter cells. The cell then builds up its store of energy in preparation for the cell division. Mitosis starts with Prophase, where the chromosomes condense becoming more tightly coiled and folded and so appear more shorter and fatter as Prophase progresses. As soon as the chromosomes begin to condense,
Photo Identification methods
CONTENTS CONTENTS 1 USES OF PHOTO ID 2 TAKE PICTURES 2 WORKING CONDITIONS 2 UTIFITY 3 CRITERIA SELECTION PHOTO 5 SAMPLING 5 ERRORS 8 DISADVANTAGE 8 DATA COLLECTION 8 DATA ANALYSIS 8 OUR OBSERVATION - EXAMPLE PHOTO - ID 9 HUMPBACK WHALE 9 MINKE WHALE 11 WHITE - BEAKED DOLPHINS 12 DEDUCTION 14 REFERENCES 15 SUPPLEMENT 16 CHECKLIST USED PICTURE 16 OTHER INTERESTING PICTURE TAKE DURING USE PHOTO - ID 16 USES OF PHOTO ID Photo identification it use for watching and determining animals behavior, population biology and ecology. For example animals behavior can be group composition, social interactions and focal animals behavioral observations. For example population biology can be life span, birth rate, mortality rate and abundance estimates. Population must be definable because at least two and preferably more animals. Should be made to try to ensure that all animals have an equal probability of being captured during any one sampling. Should be made to try to ensure that all animals have an equal probability of being captured during any one sampling occasion. Better chance to capture the animals with a high probability of bias caprure number of recaptures up and leads to underestimation of population size. Identify an invidual animals is possibly, because we photographing sample of animals at deferent places - > enable movement and migration. It can also
Components of Biological Membranes.
Components of Biological Membranes Introduction. Biological membranes surround all living cells, and may also be found surrounding many of an eukaryotes organelles. The membrane is essential to the survival of a cell due to its diverse range of functions. There are general functions common to all membranes such as control of permeability, and then there are specialised functions that depend upon the cell type, such as conveyance of an action potential in neurones. However, despite the diversity of function, the structure of membranes is remarkably similar. All membranes are composed of lipid, protein and carbohydrate, but it is the ratio of these components that varies. For example the protein component may be as high as 80% in Erythrocytes, and as low as 18% in myelinated neurones. Alternately, the lipid component may be as high as 80% in myelinated neurones, and as low as 15% in skeletal muscle fibres. The initial model for membrane structure was proposed by Danielli and Davson in the late 1930s. They suggested that the plasma membrane consisted of a lipid bilayer coated on both sides by protein. In 1960, Michael Robertson proposed the Unit Membrane Hypothesis which suggests that all biological membranes -regardless of location- have a similar basic structure. This has been confirmed by research techniques. In the 1970s, Singer and Nicholson announced a modified version
A comparison of marine organisms on shale & limestone coasts. Doolin, Ireland.
A COMPARISON OF MARINE ORGANISMS ON SHALE & LIMESTONE COASTS. DOOLIN, IRELAND. Introduction Doolin is situated in the Burren area of county Clare, Ireland. The area is famous for its limestone landscape and is highly acknowledged as an area of global importance for its flora, fauna and ecology. Doolin represents a unique limestone pavement and terrain which supports a diversity of rare marine habitats. In 1988, in recognition of its importance, the state Wildlife Service recommended the designation of the area as a Nature Reserve. Due to the extent of coastline in county Clare, the marine and coastal habitats are very important. The Atlantic Ocean off the west coast of Ireland is relatively clean compared to other oceans. This is illustrated by the amount of seaweed there. The Gulf Stream off the west coast of Ireland creates a warm, oceanic climate, which has a very significant influence on the species and habitats which occur in Doolin and increases the biodiversity. -Fig 01- Doolin Village The Doolin coast consists of both limestone and shale wave-cut platforms, both of which appear rich in diversity of flora and fauna. Doolin coast contains a wide range of invertebrates, some highly mobile, others fixed or sedatory, and shore fishes, are a characteristic feature. Brightly coloured lichens form distinct bands on the high shore, seaweeds are present in abundance,
Discuss how changes in control of the cell cycle contribute to cancer development Cancer is a multifarious disease, with a common feature that most tumours harbour one or more genetic mutations that allow them to advance outside their normal growth restr
Discuss how changes in control of the cell cycle contribute to cancer development Cancer is a multifarious disease, with a common feature that most tumours harbour one or more genetic mutations that allow them to advance outside their normal growth restraints. This proliferation is normally harnessed by the control of the cell division cycle, which in turn, is majorly regulated by the cyclin dependent kinases (Cdks) family of serine/threonine kinases and their regulatory partners, the cyclins (Errico, et al., 2009). In this essay, the roles of Cdks, cyclin complexes, regulatory proteins and other cell-cycle regulatory processes will be underlined, followed by an analysis of the genetic lesions in these regulators which may contribute to tumorigenesis. Fundamentally, cancer, or a neoplasm is a disease where cellular proliferation is no longer under normal growth control. The growth of this clone of cells exceeds, and is uncoordinated with that of normal surrounding tissues (NHS, 2009). Ultimately, this deregulation of growth and division of the cancer cells disrupts and interferes with the normal functioning of the body, either at its origin or through spreading to another location, eventually resulting in the potential death of the sufferer if left untreated. Other complex characteristics include the ability of the cancer cells to induce vascularisation of the tumour in
International Biodiversity Day 2005
[SW1] International Biodiversity Day 2005 Sunday May 22, was the International Day for Biological Diversity. Each year celebrated to increase understanding and awareness of biodiversity issues. Biological Diversity is defined[SW2] as: Life on earth: the variety of all plants, animals and microorganisms. Celebrating the day also marks the signing of the International Convention on Biological Diversity by 150 government leaders at the 1992 Earth Summit (aka the Rio Summit) in Rio de Janeiro, Brazil, dedicated to promoting sustainable development. Thought as a practical tool for translating the principles of Agenda 21 into reality. The Convention recognises that biological diversity is about more than plants, animals and micro-organisms and their ecosystems. It is also about people and our need for food security, medicines, fresh air and water, shelter, and a clean and healthy environment in which to live. Biodiversity is the source of the essential goods and ecological services that make up the source of life for all. The celebration each year of the International Day for Biological Diversity is an occasion to reflect on our responsibility to safeguard this precious heritage for future generations. Sadly, the earth's biological foundation is eroding at a rate unequalled in at least 65 million years. Globally, species have been disappearing at 50-100 times the natural
Drugs from the Sea.
Drugs from the Sea Tyler Herrington Chemistry 11 Mr. Tuckwell Oct. 1, 2003 Medicinal drugs are a very important issue to many humans today. They are used to prevent diseases and to cure infected people. Unfortunately, many strands of bacteria are now becoming immune to many of our current vaccines, and we urgently need to find new sources of disease fighting entities. A marine biology based institution, by the name of the Scripps Institution of Oceanography, located on the coast of California, in La Jolla, has realized that the ocean has many great opportunities for new medicines; it is just a matter of where we look. A marine biologist, based at this institution, by the name of William Fenical, is the director of marine based vaccine research. His current research could lead to future vaccines for cancer and possibly even today's incurable viruses. He explains that the days of being able to just wander a forest, take a dirt sample, and find a medicinal substance are over. Many of the past medicines, he says, are becoming obsolete. Many marine vaccines are currently in clinical trial and a few look like they could be successful in the near future. Ecteinascidin 743, for example is a marine-based drug, derived from a sea whip, Ecteinascidin turbinata, which has been proven in lab studies to be effective in fighting against human breast cancers and rodent leukemias.
Macromolecular composition of a liver cell
Macromolecular Composition of the Liver cell Abstract A liver cell is to be homogenised and fractionated into a nuclei rich sediment and a nuclei free supernatant using centrifugation. After treatment with perchloric acid the samples are centrifuged producing supernatants containing glycogen, and these are decanted and stored. The sediments are washed, then treated with KOH and perchloric acid and centrifuged again. This supernatant contains ribonucleotides and it is also stored. The remaining precipitates are suspended in KOH and incubated to ensure it is fully dissolved. The addition of various reagents to each of the supernatants and suspended sediments will allow for an examination of the distribution of RNA, DNA, glycogen and protein, and for an explanation of why this is so. Introduction For supernatants to be produced for examination of this kind, the liver cells must be fractionated to allow specific organelles and molecules to be collected. This is done through homogenisation and differential centrifugation. During homogenisation citric acid is added and in put in a pre-cooled homogeniser; liver is easily broken up. It would be relatively much more difficult to homogenise a plant cell due to the presence of a cell wall, an outer layer that maintains cell shape and is made of cellulose, other polysaccharides and protein (Campbell and Reece, 2005). A centrifuge
proteins in mammalian PC12
The behaviour of long polyglutamine-containing proteins in mammalian PC12 cells Project report in partial fulfilment for the degree of MSc in Neuroscience August 2008 Janahi Visakan Supervised by Dr Angela Hodges Department Of Neuroscience Institute of Psychiatry King's College London University Of London The behaviour of long polyglutamine-containing proteins in mammalian PC12 cells Abstract Huntington's disease is an autosomal dominant, inherited neurodegenerative disorder induced by a glutamine expansion repeat at the N-terminal end of the huintingtin protein. These N-terminal fragments of huntingtin aggregate in the nucleus and destroy cells. This genetic disorder is accompanied by motor, cognitive, personality changes and psychiatric symptoms. If the number of glutamine residues increase to more than 37, then this induces an adult, onset gradual progressive neurodegeneration known as HD.The genome of D.discoideum, a social amoeba consists of polyglutamine fragments longer than 40 residues. These long polyglutamine fragments do not confer any toxic effects .In addition the genome sequencing of D.discoideum has demonstrated that this organism is able to withstand a large number of proteins containing long polyglutamine stretches. A synthetically generated CAAX repeat construct was clone d into a mammalian expression vector using the gateway system (Invitrogen) to