Stem cell research use and, how it may help find a cure for muscular dystrophy

Stem cell research provides hope for the cure of muscular dystrophy. Stem cells research is a relatively novel technology that utilizes primitive cells of human beings and develops them to come up with a variety of human cells including brain cells, blood cells and muscle cells. Scientists claim that stem cell research provides hope for and has the potential to reveal treatments and possibly even cures for serious diseases such as neurodegenerative diseases like Parkinsons and Alzheimers disease, diabetes, heart diseases and muscular disorders such as Muscular Dystrophy. This paper is going to explore published work, reviewed journals and legitimate websites to reveal the uses of stem cell research and how it can be utilized to find a cure for Muscular Dystrophy.

Introduction
Human stem cells, according to National Bioethics Advisory Commission, United States, are obtained either from embryos or adult tissue (p, 9). Embryonic stem cells can be developed for the sole intent of stem cells research these cells can also be leftover embryos from other sources such as in-vitro fertilization (National Bioethics Advisory Commission, United States p, 11). National Institutes of Health states that in in-vitro fertilization embryos are developed in surplus in advance and only a few embryos, which are considered most viable, are selected for fertilization treatment (para, 1). This results in some embryos being leftover. They are donated to those looking for fertility assistance and also for the purpose of research or destroyed in case they are not put into use. The process of harvesting of embryonic and adult stem cells for medical purposes, according to National Institutes of Health, can be referred to as therapeutic cloning (para, 1). Though closely related to reproductive cloning the goals of therapeutic cloning are different. It does not strive to develop whole human beings rather it focuses on making embryos as a resource of embryonic stem cells for medical purposes (Forman p, 10). Adult stem cells are obtained from adults with minor injury to the adult. It is however, difficult to harvest adult stem cells as compared to embryonic stem cells. Embryonic stem cells can also be utilized for numerous roles as compared to adult stem cells. As a result of their potential use as well as the question in regards to when life begins, embryonic stem cells are the principle subjects of debate concerning stem cells research (Forman p, 11). This debate, in general as asserted by the Forman, contains two major ethical concerns the potential for human cloning and whether pre-embryos and embryos are human life (p, 20). The fears of human cloning, brought about by stem cell research, generate a huge controversy over this issue. When stem cell research first gained popularity scientists were concerned with the likelihood of employing stem cells to clone humans. Proponents, as indicated by the National Bioethics Advisory Commission, United States, give many reasons in support of human cloning, including the likelihood of developing another person and in case body parts and tissues become diseased or dysfunctional replacements can be obtained from the clone (p, 209). Opponents on the other hand argue that it is not within mans authority to develop, control and destroy human life. Opponents argue that life begins at conception and that the use of human and even embryos, for purposes of research is not ethical (National Bioethics Advisory Commission, United States p, 213). Proponents on the other hand argue that embryos are only insignificant amounts of undifferentiated tissue, and due to the fact that they are already destined for destruction and have great potential benefit, they are supposed to be used potentially to help others. In the United States it is legal to carry out stem cells research. Privately financed laboratories carry out both adult and embryonic stem cell research with leftover embryos from other processes as well as those specifically harvested for research (Forman p, 85).

Stem cell research use and, how it may help find a cure for muscular dystrophy
Stem cells, according to Starr, have a very high potential of developing into any type of cell in the body (p, 35). These cells also serve as a source of cells for internal repair system. They continually divide in order to replenish other cells for as long as the person is alive. After dividing, stem cells have the ability of remaining either as stem cells or becoming other specialized cell types in the body such as blood cells, brain cells or muscle cells. Stem cells have the ability of renewing themselves through cell division (Starr p, 42). Starr states that, they can also, under specialized experimental or physiological conditions, be induced to become specialized tissue or cells to carry out specific roles (p, 42). In some organs, for example the gut, brain, and bone marrow in addition to muscle cells, stem cells continually divide to replace and repair tissues that are worn out or damaged. In other organs such as the pancreas, the liver and the heart stem cells can only divide under special circumstances.

Stem cell research is currently focusing on how stem cells can be manipulated to create replacements for diseased and dysfunctional tissues and organs (National Institutes of Health para, 2). Stem cells, as EuroStemCell asserts, offers hope that one day a cure for wasted muscles in patients with muscular dystrophy will be obtained (para, 1). Studies carried out using mice have revealed that some types of stem cells found in blood vessels could greatly assist individuals suffering from particular forms of muscle dystrophy such as Limb-Girdle Muscular Dystrophy (EuroStemCell para, 1). Researchers however, argue that a lot of studies need to be carried out before these findings can be applied to humans. This offers a new focus on research relating to muscular dystrophy. Muscular dystrophy, according to EuroStemCell, is a group of muscular disorders brought about by genetic defects that result in the death of muscle cells and an increase in muscle weakness as time progresses (para, 1). Gene mutation is the major factor that leads to muscular dystrophy (EuroStemCell para, 1). Degeneration, in Duchenne and Beckers muscular dystrophy for example, occur as a result of genetic fault in the production of dystrophin, a protein in the muscle fibers (EuroStemCell para, 2). Currently this disorder has no cure. However, research has shown that if genetically corrected stem cells are introduced into muscles that have been affected by muscular dystrophy they could redevelop muscle fibers that have fully functional stem cells (EuroStemCell para, 3). Once the corrected cells are delivered into the target muscles they would continually produce new groups of muscle cells that are healthy to replace the damaged fibers. Research has revealed that if stem cells are targeted and their numbers boosted the bodys ability to repair muscles could be enhanced (University of New South Wales para, 2).

Scientists have discovered that stem cells, also referred to as mesoangioblasts, have the ability of crossing into muscle tissue from bloodstream (University of New South Wales para, 2). Scientists, therefore according to University of New South Wales, suggest that mesoangioblasts could be obtained from a patients blood vessels, corrected in the lab, and then injected back into the bloodstream (para, 2). The corrected stem cells could then migrate from the patients bloodstream into the muscles where they would start producing healthy cells. These cells would not be attacked by the patients immune system because they were originally obtained from that person (University of New South Wales para, 3). Research, as stated by Cellnews, conducted using mice revealed that treated muscles contained a lot of larger and apparently healthier muscle fibers (para, 2). Mice that had their muscles treated were able to walk on a rotating wheel for a longer period as compared to those whose muscles were not treated (Cellnews para, 2). Scientists however, argue that a lot of hurdles need to be broken before these findings can be applied on human beings. One of the hurdles to overcome concerns that most appropriate way to deliver mesoangioblasts to their target sites. The consequent integration as well as survival of the cells they produce is the other problem. The third hurdle that scientists have to overcome is the mode of controlling the bodys immune system response to foreign cells. The other hurdle that scientists face involves most suitable techniques to use in order to preserve all other stem cells destined to become muscle cells as well as avoid the danger of development of other diseases such as tumors, while enhancing the overall strength and coordination of muscles (Cellnews para, 3). The other problem is that stem cells have the ability of making a wide variety of cells it is very hard for scientists to trick and pull out only the cell they want. All in all Scientists are focused on primary study into muscle stem cells of both embryonic and adult origin. Scientists have isolated mesoangioblasts from biopsies of human muscles in order to gain a proper understanding of their properties and also observe how these cells might behave if transplanted (EuroStemCell para, 5).

Stem cell research is a major avenue of studies that are aimed at discovering cure for muscular dystrophy. Scientists argue that, if corrected mesoangioblasts are transplanted into the muscle, this would lead to muscle regeneration and result in stronger contractility (EuroStemCell para, 6). Studies have also revealed that muscle coordination of treated mice is better than that of untreated mice, though not as good as normal mice (University of New South Wales para, 5). However, the improved coordination is significant because it reveals that corrected mesoangioblasts have benefited the quality of life of the animal. Research is being conducted to reveal whether corrected stem cells have the ability of generating muscle stem cells to replenish muscles (University of New South Wales para, 6).  Studies carried out by a Harvard research team, allowed them develop a new procedure that gave them a ready entry to a supply of adult mesoangioblasts in mice they used these stem cells to counter the impacts of Duchenne Muscular Dystrophy in experimental animals (Carroll para, 1). This team was able to distinguish muscle stem cells by identifying fundamental proteins found on the surface. They were then harvested and transplanted into the muscles of diseased mice. The transplanted stem cells, as indicated b y Carroll, spread from the injection point and prompted the development of novel stem cells that assisted in improving performance of the muscle (para, 1). Wnt7, as research carried out by the Harvard research team revealed, is a protein that increases adult stem cells production in muscle tissue (Carroll para, 1). This protein therefore plays a major role of building muscle tissue that is bigger and stronger. This study, by the Harvard research team, reveals the presence of regenerating muscle mesoangioblasts in skeletal muscle of adults, and exhibits the probable benefits of stem cells therapy if used for the treatment of degenerative muscle disorders such as muscular dystrophy (Carroll para, 2).

Conclusion
It can therefore be concluded that stem cell research provides hope for the cure of muscular dystrophy, a group of muscular disorders brought about by genetic defects that result in the death of muscle cells and an increase in muscle weakness as time progresses. Stem cell research is currently focusing on how stem cells can be manipulated to create replacements for diseased and dysfunctional tissues and organs. Human stem cells are obtained either from embryos or adult tissue. Embryonic stem cells can be utilized for numerous roles as compared to adult stem cells, because they have a very high potential of developing into any type of cell in the body. Research conducted using mice revealed that treated muscles contained a lot of larger and apparently healthier muscle fibers. Transplantation of treated mesoangioblasts into the muscle, leads to muscle regeneration and results in stronger contractility of muscles. Muscle coordination is also enhanced if corrected stem cells are injected into the diseased muscles. Improved coordination reveals that corrected mesoangioblasts benefits the quality of life of a patient.

Pros and cons of genetic engineering

Genetic engineering is the alteration of genetic material by direct intervention in genetic processes with the aim of creating new substances or improving the functions of the existing ones. It is a young, exciting, and controversial branch of the biological sciences. It brings with it the possibilities for cure of several genetic diseases and numerous material improvements to the every day life of man. Human genome projects is one of the signs of benefit of genetic engineering where as there are also threats for potential malicious use of the technology.  

Scientists are now able to create new species of animals by transferring genetic material from one or more organisms and genetically modifying them into the genes of another organism. The process results in creation of new organisms which are completely new to the earth and are made to specifically posses the traits that humans desire in either plants or animals (Arnold, para. 3).

This simply implies that through genetic engineering, farm animals can be made to grow faster and have desirable traits like having healthier meat and flesh and tolerant to pain and suffering which are always common in the current farms. Genetically modified animals are also used in research to enable researchers discover treatments for genetic diseases such as breast cancer. Animals which are facing extinction or those that are endangered can be cloned and this serves the wildlife management in achieving their goal of preserving and also ensuring that endangered animals information are not lost when the last of them finally dies (Barash, para. 4).

Principles of genetic engineering
The focal point of genetic engineering is the recombinant DNA which simply means a DNA which is genetically altered via the process referred to as gene splicing. In gene splicing, a DNA strand is divided into a half in terms of its length and joined with genetic material from another organism or another species of organism. Application of gene splicing results in two new important techniques. Gene transfer or inclusion of genetic material into the cell of another organism is achieved through the use of micro organisms that serve as vectors or carriers. Gene therapy is therefore defined as introduction of normal or genetically changed genes to cells so as to replace the faulty genes which are responsible for genetic disorders (Chadwick, para. 3).

It is also possible to divide DNA into shorter strands by the use of restriction enzymes whereby enzyme in this context refers to a type of protein that hastens the process of chemical reactions. The ends of the shorts fragments are highly attracted to complementary ends on the other DNA fragments and will be attracted to those strands found in the target DNA. By simply looking at the size of the fragment created through the use of enzymes, researchers are able to know whether the gene has proper genetic code or not. The technique has been employed in the analysis of fetal cells and in diagnosis of some specific blood disorders such as sickle cell anemia (Branford, p. 23).

Genetic engineering just like any other important technology or human action has benefits and costs. It is just similar to convectional industrial technology which is quite beneficial but can also be extremely dangerous if it is not practiced with caution. When the technology is used exclusively for constructive purposes such as a generation of medicine and research for human diseases, it can be very useful to the society. The use of genetic engineering for biological warfare raises a lot of concerns on the potential of abuse of this technology. In discussing genetic engineering, this paper is going to consider the pros and cons of the technology in the fields of agriculture, medicine, and food production (Perzigian, para. 5).

Pros of genetic engineering
The most famous reason given for the support of genetic engineering is its potential use in preventive medicine. Just a few cells from an embryo can be genetically analyzed to detect harmful mutations or predilection to certain genetic disorders at which point could be genetically taken either through somatic cell or germ line gene modification. Some of the advancements in the field of medicine include discovery of the causes of Huntingtons disease which has enabled the scientists to strive to determine its normal functions (Jeremy, p. 11). Should researchers succeed in these studies, the technology could then be applied in eradicating debilitating and sudden dangerous diseases that affects almost 30,000 Americans and which is also able to affect 150,000 more individuals via genetic inheritance. The second achievement in the field of medicine courtesy of genetic engineering is successful diagnosis of familial adenomatous polyposis coli which is the dominant cancer predisposition syndrome which was realized in three implantation embryos. The cancer predisposition affects 1 individual in every 1000 Americans, British and Japanese therefore it is a common difficulty. Other developments include demonstration that schizophrenia is inherited and birth defects such as Downers syndrome can be eliminated via genetic engineering (Nicholl, p. 126).

The second reason for genetic engineering is the elimination of common defects that differ in seriousness like sensory impairment. Several chromosomes associated with hearing impairment have been identified. Despite the fact that the management of these conditions initially appeared possible, as the eradication of complete blindness or deafness would improve the quality of life of these patients, complete elimination of sensory conditions and actually lifting sensory ability to a level which is above normal are separated by a very small line.

Genetic engineering is widely applied in the field of agriculture. Food crops such as maize, rice, and potatoes are being genetically modified in several ways. Some of the benefits of genetic engineering in agriculture are higher crop yields, production of more nutritious foods, ability of the crops to be grown even in harsh environment, production of crops which are more resistant to pests and this eliminates the use of potentially dangerous pesticides, ability to remove undesirable traits, foods with better flavor and longer shelf life, and possibility of using crops as cheap source of medicine (Barash, para. 7).

Genetically engineered seeds are not eaten by pests and are able to survive in relatively harsh climatic conditions. There is a recently discovered plant gene referred to as At-DBF2 which when introduced into a tomato and tobacco cells is observed to increase their adaptation to harsh soil and climatic conditions. Biotechnology can also be applied in prolonging half life of foods, therefore fruits and vegetables can have their shelf life greatly improved. Genetic engineering in food can be employed to produce completely new substances like proteins and other food nutrients. Genetic modification of foods can also be employed in increasing the medicinal value of foods therefore resulting in homegrown edible vaccines.

Genetic engineering has a great ability in case of human beings. Human genetic engineering is the branch of genetic engineering which is involved with modifying the genes of humans before they are born (Redmond, para. 8). The technique can be applied in altering certain traits in an individual. Positive genetic engineering is concerned with enhancing the good traits in an individual such as increasing life expectancy or human capacity while negative genetic engineering is concerned with suppression of bad traits in humans such as predilection to genetic disorders. Through genetic engineering, treatment for some dangerous diseases can be discovered. If the genes which are responsible for extraordinary qualities in human can be discovered, the genes can be inserted into the genotypes of humans. It can also be used to bring about desirable structural and functional changes in individuals (Branford, p. 23).

Through genetic engineering transgenic agricultural animals can be created. The animals created in this manner are better placed to resist disease, have enhanced growth performance, and possess greater reproductive traits. An example of an animal which has undergone genetic engineering is salmon. Transgenic salmon is able to grow into a larger size and also at a faster rate as compared to other varieties of salmon. The transgenic salmon has already been created and farmed. Genetic engineering is also used in bovines through the use of growth hormones in dairy cows to increase their level of production. With the increased use of the technology, there is a possibility that a transgenic sheep will be produced in future which will produce a better wool, cattle will be engineered to more efficiently convert feed into high quality milk and meat (Perzigian, 6).

Cons of genetic engineering
While genetic engineering is currently making a permanent mark in the society, and its promise of great things to come, the technology is faced with a lot of controversies about the ramifications it has for the society and the environment. The most common people against this practice are environmental advocates together with animal rights activists. For each benefit that genetic engineering brings, there is an intrinsic danger which comes with it. In general, the opponents of the technology maintains that it creates a huge reduction in the position of animals, rendering them as nothing more than testing objects for factory farming, drug and organ manufacturing. There are real and assumed potential risks associated with genetic engineering (Poulter, p. 23).    

Genetic engineering in terms of gene therapy can be a very dangerous business (Nicholl, p. 300). In gene therapy, a micro organism which in most cases is the virus is used as a carrier to deliver the genes being introduced inside the cell, there is some degree of fear about the possible virulence of the carrier virus despite the fact that virulence factors have been suppressed. There is also a possibility of the gene landing in the wrong place and resulting in harm to the individual by being expressed in unusual ways. There have been numerous deaths experienced in gene therapy trials with the most popular case being of Jesse Gelsinger which occurred in 1999 (Chadwick, para. 9).

Opposition to the use of genetic engineering in food and agriculture is based on several fears. One of the fears is that a gene which is supposed to make crops resistance to herbicide may spill to other crops resulting in some kind of super weed or a genetic modification that is transmitted through pollination. Creation of such plants is likely to pose some hazard to the ecosystem. There is also an issue that unusual gene expression may results in crops which are more likely to elicit allergic reactions in the people. There is also a possibility that genetic engineered foodstuffs can result in altered nutritional value in the process of improving tastes and appearance (Barash, para. 6).

Horizontal gene transfer can result in new pathogens. In the process of increasing resistance to diseases in plants, the genes responsible for resistance may get transferred to harmful pathogens. Gene therapy in humans can result in some specific side effects. While trying to treat one problem, the therapy may result in another problem. Since a single cell is responsible for several traits, identification and isolation of a single cell responsible for a single trait is not easy (Mae-Wan Ho  Cummins, p. 149).

Genetic engineering in humans can hinder the diversity of human beings. Cloning can be dangerous to individuality. In addition, such processes may not be afforded by the majority of the people thus making gene therapy impossibility for the common man (Branford, p. 23).

Transgenic agricultural animals pose various threats. There is a possibility that creating more efficient farm animals will bring to a standstill the process of selective breeding thereby resulting in lessened genetic diversity of animals. Through this, a whole hard can become susceptible to new strains of infectious diseases. An example of such a procedure which led to more problems to the animals engineered was implantation of human growth hormone into a pig by the USDA. The resultant pigs were bowlegged, cross eyed, arthritic, and had a faulty immune system which made them highly susceptible to pneumonia. The same thing can happen to cows which are normally administered with growth hormones to increase milk production are also likely to suffer from udder diseases (Jeremy, p. 11).

Should the genetically engineered animals escape into the wild, they expose native animals populations to great risks and are likely to interfere with the overall balance of the ecosystem. These animals are likely to pose ecological roulette because their exact function in the ecology is not clear. There is also another fear concerning genetic engineering that it is likely to reduce the human gene pool thereby making man quite susceptible to several diseases. Cloning also falls under genetic engineering and if the practice is taken over by malicious individuals, clones can be made for doomsday army or anything more serious than that. The practice is also considered both inhumane and unethical. Improper testing on animals is likely to result in some damage to the ecosystem (Arnold, para. 8).

Genetic engineering has the potential of causing more serious problems in the future. According to history, it takes a few decades for the complete set of risks linked with any technology to be realized. One of such development was CFC which people did not predict could cause more harm to the ozone layer like it did. The ability to think about the potential risks of genetic engineering in the future is masked by the available knowledge in the related disciplines such as psychology, genetics, and nutrition. The current pressure exerted in the food production can be equated to that experienced by the UK authorities who made them not to link BSE with a new variant of the incurable condition which was reported in man referred to as CJD. Those individuals who linked the two conditions were criticized. Unlike other faulty technology mistakes which can be fixed by redesigning the machinery, mistakes associated by genetic engineering are a bit complex and cannot be easily rectified (Barash, para. 10).

Conclusion
Genetic engineering is a valuable technology, but is does not lack faults and technical difficulties. Just like other technologies, there is non with absolute safety or zero risk. Every technology comes with risk attached to it and genetic engineering is not an exception. As long as the benefits associated with the technology are far much beyond its negative effects, and there are efforts put in place to ensure that the risks associated with it are minimized, new technologies such as genetic engineering should be pursued with a lot of dynamism.

THREATS TO BIODIVERSITY

Birds in the Hawaiian ecosystem are facing extinction due to degradation and loss of their habitat from effects of animals such as the feral ungulates. These animals eat native plants and destroy ground cover through their hooves and grazing activities. According to the bird channel website, there has been a 64 reduction in the birds population during the period 1973-2000. It is estimated that nearly two thirds of birds extinctions in the United States have happened in Hawaiis habitats. These birds are also killed by avian malaria transmitted by mosquitoes. In order to restore the Hawaiian ecosystem, the population of ungulate animals needs to be regulated. Birds such as the Akikiki and Akekee have already been classified among the birds facing extinction through the Endangered Species Act, (ESA).

Animals such as feral pigs are usually omnivorous and chew tree trunks leaving holes. They also eat immature trees and young seedlings. Rain water collects in these hollows creating breeding places for mosquitoes. This facilitates the spread of malaria. Their hooves also leave behind pits which may form shallow ponds on the ground that acts as breeding places. The Axis deer and feral sheep feed on native trees and seedlings that birds depend upon as sources of their food. This has led to devastating effects on the survival of birds such as the honey creeper. Destruction of seeds and seedlings result to food shortages as a result of the disruption of the food chain. Goats and feral cattle are able to graze over large areas of land in search of pasture. They act as agents of deforestation leading to reduced numbers of bird population that live in forests. This is due a reduction in the level of vegetation cover since cattle are heavy feeders and graze in large numbers. They dont allow space for regeneration of new vegetation growth (Drost and Fellers). Their breeding rates are also very high and if left uncontrolled will lead to total removal of vegetation cover. Initially most of the vegetation cover consisted of lowland ecosystems that can not adapt easily to ungulate activities and therefore urgent measures needs to be taken to conserve the ecosystems.

Ungulates are also known agents of seed dispersal through their hooves and also through their feeding habits, they are able to spread seeds of invasive weeds such as the naturalized vascular alien plants which are aggressive in terms of out competing the survival of native plant species which are depended upon by birds as food (Jenkins and Maguire).

Soil erosion caused by hooves of ungulates has facilitated the growth of invasive plants. Ungulates destruction of vegetative cover has made it possible for rodents like rats to survive in the destroyed vegetation. These rats prey directly on the birds and also eat eggs laid by birds. This makes it difficult for the population of birds to grow.

It can clearly be seen that measures taken to conserve the Hawaiian ecosystem will be very difficult without the elimination of ungulates. The most important measure towards successful restoration efforts of birds survival will be to eliminate control the ungulate population. Measures such as monitoring the population of ungulates by creating separate areas for these animals can be achieved through fencing. Spread of ungulates should controlled by preventing further migration of these animals to new areas within the ecosystem. The government should also fund conservation efforts towards restoring the ecosystems of birds. This can help in preventing birds from facing possible extinctions (Stone and Loope).  

Human population and new disease out breaks

Drug resistance has increased in the recent years. This is because of the poor use of drug and drug products. Because of drug resistance, human populations are faced with the danger of disease out breaks and emergence of new diseases from resistant strains. This paper is going to look into some of the factors that contribute to the increase of these risks and measures that can be taken to avoid the situation.

Human population is faced with a danger of being infected with emerging diseases. Emerging diseases are those diseases whose occurrence in humans has been on the rise in the recent past and still threatens to continue increasing. These diseases can also be occurring for the first time and are spreading to different areas. They can be transmitted through different means such as person to person transmission, transmission by insectsanimals or through water contamination. There are many factors that have been found to enhance development of new infections which include human, biological and environmental (Bowen et al, 2007).

In biological causes, the major contributing factors are mutations and drug resistance. New infectious strains can be as a result of unregulated use of drugs together with misuse, mutation of disease causing organisms or it can be as a result of drug abuse. Because of this, new strains of more infectious organisms are likely to develop and there will be an increase in antimicrobial resistance which will be resistant to the current available drugs leading to new infections that are drug resistant. This will affect the way in which drugs used in treatment of common diseases work (Brower  Chalk, 2003).

Microorganisms undergo mutations that help them survive in increasingly hostile conditions in the hosts. An example is the HIVAIDS which was not know until, the early 1980s but it has spread and infected about 24 million people world wide. Its origin is not exactly known but its suspected to have originated from monkeys which had viruses that caused Aids-like illness. New types of hemorrhagic fever have emerged with Ebola being the most notorious of all. The first case of Ebola was first discovered in Zaire and Sudan in the year 1976. It has since spread to countries like Cote dlvoire, Liberia and other countries. Animals are presumed to be the carriers of this virus but no exact animal has been identified (Outbreaks of Animal-Related Illnesses, 2003).

Hantavirus syndrome in the USA has also emerged with characteristics of respiratory failure and a fatality rate of more than 50  of its victims. Since its detection in 1993, it has continued to spread to different states and countries like Argentina together with Brazil. Rodents are the primary carriers of this virus in particular the deer mice. Other discoveries of Hantaviruses have been found in Asia for a long period of time in which they cause hemorrhagic fever in man (New WHO Office, 2001).

A worldwide influenza pandemic threat is continually increasing. It has been noted that in every 20 years there occurs a major shift in the genetic composition of influenza virus triggering epidemics in most parts of the world. Another shift is expected to happen in the near future. The origin of influenza virus is thought to be China. Ducks, pigs and chicken act as reservoir hosts to the virus. When they are raised together in farms, exchange of genetic materials between the viruses occurs which bring about new strains of the virus. This results in an epidemic of human influenza with each epidemic resulting from a different strain of virus.

Strains such as cholera strains together with influenza no longer follow the previous pattern where they used to infect children but instead they infect all age groups. This is because of the new strains that adults have also not acquired immunity against them which comes about after an infection.
According to Huhn et al, 2005, development of different kinds of strains is brought about by treatments that do not bring about cure. An increase in the use of antimicrobials which are usually in form of sub-therapeutic doses and counterfeit is an indication in more problems that are likely to emerge in the near future.

Modern medicine practices have also contributed to the spread of new diseases. Spread of diseases found in blood such as hepatitis and others like syphilis HIV and malaria have been on the rise. Medical procedures like kidney dialysis, multiple blood transfusions together with the different forms of transfusions have contributed greatly to the outbreaks. Other practices in immunization such as Relaxation quickly result to reoccurrence of some diseases. An example is the latest spread of diphtheria in Russia together with former USSR republics (Loppacher, Kerr  Barichello, 2008).

New diseases in animals like bovine spongiform encephalopathy are exposing a great health risk to human beings. This disease causes madness in cows and there are fears that the organisms responsible may be passed on from cows to humans causing a variant incurable Creutzfeldt-Jakob disease that affects the brain. Because of this threat, the beef market in Britain has largely been affected with strict measures being introduced to safeguard the health of the British population (Bowen et al, 2007).

Antimicrobial resistance
This has become a major public problem through out the world. It occurs when organisms that bring about diseases become resistant to antimicrobial drugs together with other agents used in treatment. Resistance occurs in the following ways through evolution of the molecule in the target moleculeorganism of a particular drug making it impossible for the drug to bind with the molecule, the target cell or organism may produce better enzymes that corrupt the drug or the organisms can come up with a way of eliminating the drug from their system (Drake, 2005).

Because of resistance, there has been an increase in the number of infections that can not be treated using the normal treatment. This has had a negative impact on treatment of diseases like T.B, cholera, pneumonia, malaria and dysentery. These are not the first cases of drug resistance because the problem has existed for almost a decade. This period saw a decline in new antimicrobial development with an increase in resistance to existing antimicrobials. This has left doctors together with parents in a helpless situation. Each and every individual regardless of their age group is affected. The Elderly, young, chronically ill, people with compromised immunity together with patients undergoing surgery are at risk of developing resistance to existing medication (Loppacher, Kerr  Barichello, 2008).

According to Caballero-Anthony (2006), drug resistance increases the probability of an individual dying, elongation of an epidemic and also longer periods of illness. Bacteria have an inherent ability to evolve genes which help them become resistant to any antimicrobial. When an antimicrobial agent kills susceptible bacteria, it gives selective pressures that encourage bacteria with resistant gene to overgrow. When antimicrobial agents are continuously used, resistant strains multiply and spread.
A good example is the current crisis of antimicrobial resistance which is a result of unregulated together with inappropriate use of antibiotics. Some people use antibiotics in treatment of wrong infections, they also dont take the required doses or they prolong or shorten the period that they are supposed to be using the drug. This has brought about numerous implications in the medical world. Drugs that cost a lot to produce can only be used for treatment within a short period of time after which they become ineffective. As resistance continues to mount, the gap between infection and control widens reducing the lifespan of drugs and people.

Examples of bacterial resistance
Enterococci bacterial that is a common infection in hospitals has developed resistance to the first line drugs of treatment like beta-lactams and aminoglycosides. This has caused patients to suffer for a long period of time with only one option of treatment by vancomycin which is administered intravenously. Although Vancomycin has been the treatment of choice for long, it has gradually started developing resistance over the past 10 years.

Staphylococcus that causes food poisoning, skin infections, osteomyelitis, endocarditis together with other disorders, has also become resistant to all antibiotics apart from vancomycin. In case a strain that is resistant to vancomycin emerges, most hospital-acquired infections will be impossible to treat.
Streptococci which is the commonest cause of bacterial diseases, has slowly become resistant to a number of antibiotics for the last quarter of a century. It causes infections in the middle ear, wounds, throat and skin.

Pneumococcus which is responsible for respiratory infections among children is also becoming resistant to drugs.  Its strains that could previously be treated using penicillin are becoming resistant with 18  of the cases being reported in American and 40 in South Africa.

Malaria resistance comes with a double resistance. This includes plasmodium parasites resistance to anti-malarial medications and resistance of the anopheles mosquitoes to insecticides hence limiting the action of anti-malarial drugs. Anti-malarial drugs act by killing malarial parasite when multiplying in the blood. Unfortunately because of the poor supply and use of drugs, rapid resistance to the drug in majority of places world over has arose (Infectious Diseases, 2004).

Drug resistance in TB has also become wide spread in the recent past although a lot of attention has been turned to the alarming occurrences of multi-drug resistance strains common in the states. Drug resistance is a result poor prescription of drugs or lack of compliance with prescription. It becomes dangerous when it has become incurable leaving doctors with a situation similar to that that existed prior to discovery of antibiotics (Edison, Sewell, Graves  Olson, 2000).

Drug resistance brings about problems in metabolism. It also leaves doctors wondering on other means available that they can use in controlling the spread of the resistant strain to the rest of the population. Resistance to first line drugs for HIVAIDS, T.B, respiratory infections, malaria and also diarrhea has made the diseases to be among the leading killers in the world. It has also led to doctors turning to the second or third line drugs of treatment that have proved to be expensive. If this alternative treatment (second and third line of treatment drugs) also becomes in effective because of resistance then doctors will run out of treatment options unless new discoveries are made (Drake, 2005).

In order to avoid the risk of out break of new diseases, we need to be cautious in the way we use drugs. Drugs should be used according to instructions that are given and within the specified period. It is through that, that we can avoid emergence of new diseases that are resistant to medication. Vectors through which new infections can be acquired should be given proper attention and necessary steps taken to ensure they do not infect people.

Glycosylation

Glycosylation refers to an enzymatic process involving the linking of saccharides to generate glycans (Haltiwanger  Lowe, 2004). This carbohydrates are usually linked to proteins and lipids in the cell. This is an important process in the body as it produces glycans which are significant biopolymers that are found within cells. The glycans that are generated have several structural and functional functions within membranes as well as secreted proteins especially in the folding of proteins. Most of the proteins that are produced in the rough Endoplasmic reticulum undergo this process of glycosylation. Glycosylation is also occurs in the nucleus in addition to the cytoplasm. There are five types of glycans that are produces as a result of glycosylation
N-linked glycans which are attached to arginine side chains.
O-linked glycans which are attached to hydroxyproline side chains.
C-linked glycans which are attached to tryptophan side chain.
Phospho-glycans which are connected through a phosphate of phospho-serines.
Glypiates which are formed as a result of the addition of a GPI anchor.

Glycosylation is both a co-translational as well as post-translational modification. It is an enzymatic controlled process that is site specific. Under this process, a donor molecule is usually added which in most cases are activated nucleotide sugars known as oligosaccharides. The process of glycosylation can take place on different portions of the same protein where the oligosaccharides attach themselves (Schachter, 2004). After attachment of the oligosaccharide and the protein is properly folded, the oligosaccharide is then removed from the protein which is then taken to the Endoplasmic Reticulum. N-linked glycosylation and O-linked glycosylation are the most common forms of glycosylation.

N-linked glycosylation
This process involves the addition of a 14-sugar molecule to the hydrogen of an asparagine located within the polypeptide sequence of the intended protein. This 14-sugar molecule is composed of 2 N-acetylglucosamine, 3 glucose, and 9 mannose, molecules.

O-linked glycosylation
O-linked glycosylation involves the addition of N-acetyl-galactosamine and which normally takes place at a later phase of protein processing within the Golgi apparatus (Hang  Bertozzi, 2005).

Critical Review of a scientific paper

Article Comparison of Two Chromogenic Media for Selective Isolation of Vancomycin Resistant Enterococci from Stool Specimens.  Journal of Clinical Microbiology, 47 4113-4116
Authors Heidrun Peltroche-Llacsahuanga, Janetta Top, Josefine Weber-Heynemann, Rudolf   Ltticken, and Gerhard Haase (2009).

Summary Overview
The purpose of the study is to compare the efficacy of two chromogenic media in on rapid detection of Vancomyin Resistant Enterecocci (VRE). The two chromogenic media under study are Chromoagar VRE (CHR) a formulation that originates from France and chomID VRE (C-ID), a formulation that originates from Germany. The introduction reveals the need to identify a medium that rapidly detects VRE. This justifies the study because serious clinical infections that are associated with VRE are on the rise (Peltroche-Llacsahuanga et al (2009 Sakka et al, 2008 Cheng, et al, 2004) yet rapid methods to detect these strains in patient samples are very costly. According to Peltroche-Llacsahuanga et al (2009) a study on the chromogenic media could provide a dependable yet affordable method in rapid detection of VRE strains and hence assist in the control of the spread of the clinical infections.  The chromogenic media performances are tested on selectivity, colony color stability and colony growth characteristics and the ability of VRE recovery from clinical stool samples. The materials used include all the June 2009 compliant species of Enterococcus which are 38 in number which are cultured on the two kinds of chromogenic media.  All these species are resistant to vancomycin at concentrations of 0.125 to 256 gml.  The National Reference Center for Streptococci acts as the data material that provides reference strains for the control experiment. Stool specimens from the gastrointestinal tracks of infected people are used as enriching media. Incubators, light microscope, digital cameras and stereomicroscope are the tools that assist in the detection process. Biochemical analysis and further identification is aided by xylose fermentation tests, Gram stain, furazolidone and mupirocin.

Confirmation of Enterococcus strains is performed by vancomycin, teicoplanin and multiplex PCR. The method entails collecting stool specimens from affected patients in intensive care unit, post surgical gastroenterology wards and oncology departments. Broth enrichment step is performed on the stool specimen overnight and reference strains Enterococcus faecium  (VREfm) and Enterococccus faecalis (VREfs) of different isotonic dilutions are streaked on both the mixed culture from patients samples and pure culture from the culture collection centers, then plated on the two chromogenic media. This is followed by a 48 hour incubatory period and observations are carried out at intervals of 24 hours. The results observed show that C-ID medium support prominent distinctive VRE colony growth as opposed to CHR after 24 hours of incubation in pure culture. In the mixed culture, a train that could not be detected with CHR was detected by C-ID and vice versa. Therefore both media had a high specificity of 98.2 percent. Individually, CHR showed a specificity of 96.5 percent while C-ID was at 97.5 percent. Color stability was also achieved after 48 hour incubation on CHR. C-ID assists distinction and early detection of colony characteristics after 24 hours but instability in colony color is observed after 48 hours. However, the study reveals that both CHR and C-ID are unable to perform rapid detection of Enterococcus. This is because of failure to detect most of the strains of Enterecocci in pure form, and only the growth of the reference strains on the media were detected. Miranda, et al (2005) highlights the efficacy of chromocult media, although the same problem of detection is observed. This is attributed to the high microbial load in the gut which led to a growth of most of gastrointestinal bacteria and yeast, an observation that has also been made by DAgata et al (2002).  Neither isotonic dilutions nor direct agar plating was able to assist in the pure selection of Enterococcus strain from the incubated cultures, although confirmation tests show that these strains were present. C-ID media presents a cost effective stool screening for detection of VRE but procedures for detection and confirmation slow down the process. Asir et al (2009) compares three chromogenic media-AES VRE agar, C-ID VRE agar which are synthetically designed for VRE detection and the traditional Oxoid VRE agar and the results show that all the media are useful in detection of VRE but it is easier with the VRE designed media. Khudaier et al (2007) use bile esculin azide chromogenic agar for VRE identification. A higher microbial load and spread of VRE occurs with patients on longer hospital stay (Donskey et al, 2001). However, selective decontamination of digestive tract suggested by some studies is not a valid method for suppressing VRE. Bonten (2006) reports that topical applications of antibiotics on affected admitted patients may not effectively eliminate VRE because of gene transfer within the strains, a study complying with that of Khudaier et al (2007) and DAgata et al (2002). Nahum et al (2002) recommend intravenous vancomycin prophylaxis but over a short period of time.  Peltroche-Llacsahuanga et al (2009) study does not point out to the possibility of gene transfer across the strains in the broth enrichment culture.  Any study done should consider caution to the workers especially those involved in collection of samples, and this is because of the high infection rate of clinical indications caused by VRE, as indicated through the study by Tokars et al (2001).

Critical Review
Generally, studies concerning evaluation of chromogenic agar in screening of VRE in stool samples are many and this is as a result of the high prevalence rates of clinical infections caused by VRE. In these terms, I would say that this is not a novel study but one that builds on other studies in the collective effort to find quicker methods to control VRE infections. Broth enrichment, PCR, and agar plating methods used for this study are widely used in microbiology studies, and several studies have compared various chromogenic agars (Asir et al, 2009). However, this is the first time that CHR and C-ID are compared on their performance in selectivity and stability of VRE strains.  This study is very important to medical microbiology. Detection of gastrointestinal flora requires rapid and accurate methodologies where pathogenecity is concerned, and therefore methods that can quickly identify disease causative agents need to be proposed. However, the method does not provide the solution to the problem and further studies need to be carried out in identifying a quicker method for VRE strains. At the moment Enterococcus detection on C-ID at 24 hours incubation seems a beneficial method although considerable delays occur in exact species identification. In hospitals the prevalence in clinical infections rates increase with the length of the hospital stay and hence early detection of VRE will aid in controlling this phenomenon. This article is well summarized with all important procedures noted in a short length. However, there is still need for further summarizing in discussion section. The mention and explanation of Pediococcus species and yeast occurrences seems to divert the attention from the purpose of the study and should have been handled as a separate study. Worth noting is that the authors have correctly used and written the bacterial names and have respected the biological nomenclature of writing scientific names. Generally, the article is concisely written but the use too many commercial abbreviations and referrals bring complexity and reduce the flow of the reading. The exclusion of titles within the study complicates the article further and jeopardizes the form organization, because it is hard to draw end of one section and the beginning of the next, except of the abstract which is bold and appears at the beginning of the document. This article is therefore written for microbiologists and an audience that is familiar with microbiological procedures.

Title
The title of the article is of a clear and appropriate length and reflects the content of the paper. This makes it easier for the reader to grasp the purpose of the study.

Abstract
For any scientific paper, the abstract is the core section because it provides the whole research in a nutshell. In my view, the authors have not achieved the purpose of total inclusive informative with this abstract. The abstract fully indicates the methodology, results and conclusions but it does not out line the aim of the study.

Introduction
The introduction reveals the research question and enables the reader to understand the importance of the study. Understandably, non-infected patients but whose guts are colonized with VRE strains are potential source of the spread of clinical infections and studies are done find a control measure through rapid detection procedures. However, there is limited literature that relates this study to others. Most of the literatures quoted are in regard to the standard procedures used. The authors should have provided more literature to enable an easy understanding on why the two chromogenic agars were preferred in solving the research question.

Materials and methods
The materials and methods used are relevant for the research question. Any microbiological analysis procedure entails isotonic dilutions of culture, culture enrichment steps, incubation and streaking on selective media. Microscopes are important instruments in observing colony characteristics.  Bacteria identification methods like gram stains, E-tests and PCR are common in similar studies, and the methodology is replicable for several other microbiology studies. The article also mentions and refers to well known procedures rather than detailing them, for instance the gram stain method and multiplex PCR are common methods that have been mention rather than  being explained. Worth noting is that references have been provided for all the methods and even a mention of the kind of study on which the method applies has been explained in some instances. The article has highlighted a clear and well explained methodology.

Results
The results presented are mostly from the authors work and there is a lack of comparison to other works.  The presentation of results in both word and graphic makes the article very comprehensive. A supplemental article is also availed to further enhance the understanding of the results. Studying colony characteristics in microbiology is best observed through photos taken. The article should have emphasized more on graphic presentations rather than explaining the colors and growth characteristics of colonies through text. Most of the results have been given in both text and figures.

Tables and figures
There is proper use of tables and figures which are well labeled but the legends are inadequately used, for instance on table 2. The tables in the article cannot be understood at first glance and one has to constantly refer to the text. The figures are clear and of high quality and can be understood as soon as one understands the article. The quality and design of the tables and figures is fairly good because of proportionality and labeling. However figure 1 is less proportionate in form.

Discussion
The authors have appropriately interpreted their results but lack of comparison to other studies makes it hard to determine the position of this study as far rapid detection chromogenic media is concerned. The authors have also not discussed the issue of contrast observation on the media between their own findings and the expectation of the manufacturer. There could be possibilities that errors in manufacture or instruction pamphlets alter the interpretation of the results. Anyway, following the methodology and discussion, it can be argued that the authors conclusion is acceptable to their findings.

Stem Cell Biology

Stems cells are cells which are capable of dividing for indefinite periods in culture and produce multiple specialized cell types. These cells have the ability of developing into many tissues such as bone, brain, muscle, and other body tissues. Embryonic stem cells are primitive cells which are capable of differentiating to any adult cell (Kurkalli, Gurevitch, Sosnik, Cohn  Slavin, 1994).

Improvement in stem cell usage
Any injury to adult nervous system can be very devastating owing to the fact that neurons are incapable of regenerating after injury to assume the normal function. Insult to the central nervous system results in a break in communication as well as series of events that can lead to cell death. The discovery of stem cells which are capable of differentiating into neurons is a breakthrough in brain repair. It can be achieved through stimulation of stem cells present in the adult brain or through transplantation (Bruijn, 2007). The discovery of the use of these cells in carrying out brain repair after injury is the driving force in this explosive field of research. The idea of stem cells can also be involved in developing drugs and testing for their safety.

Concerns on the commercial use of the therapy
As much as the discovery is considered very important in treating brain damage, it is important for the scientists and clinicians to use it with a lot of caution, plan thorough studies on its use, and concentrate on the main laboratory experiments to provide answers to the challenges still facing this approach. For the therapy to be safe for use, it is important that adequate and necessary studies are carried out to learn about its properties and complexities of different stem cells available (Bruijn, 2007).

Why Marijuana should remain illegal for medicinal purposes

Medicinal marijuana is also known as Medical Cannabis. Physicians for patients requiring stimulation of all sorts prescribe it as herbal therapy. For example, it is used to induce hunger in those with low appetite, treat glaucoma, avert vomit and diarrhea as well as relieving pain. It has been in use as early as 737 B.C. Medical marijuana can be administered through drinking, smoking, vaporization and in capsule form. Some of the countries that use marijuana for medicinal purposes include Austria, Netherlands, Spain, Germany, Israel, Portugal and some states in America among others. This case study seeks to oppose the argument that certain illegal substances such as marijuana should be used legally for medicinal purposes.

Proponents
Proponents argue that medicinal marijuana has more benefits to its partakers than risks. They claim that medicinal marijuana has proved to be effective in the treatment and control of symptoms as well as reducing chronic pain in patients. These conditions include glaucoma, AIDS, epilepsy, cancer, migraines, and multiple sclerosis among others. They feel that less deaths would be reported resulting from these conditions if medicinal marijuana was legalized. They also claim that medicinal marijuana has satisfied researches by the fact that it is less toxic as compared to other legal drugs This makes it safe for use in treating and relieving the above conditions. They feel that patients using medicinal marijuana should be protected by the law against penalties.

The physicians who offer it as a prescription must also be protected by the law. They continue to argue that smoked marijuana has no well-clarified health risks and this makes the safer as a legal prescription. They go ahead to say that puffing is the best medicine and that air pollution poses greater health threats than a joint of marijuana. It has been established that patients partaking the medicinal marijuana were more immune to diseases than those on placebo were. They also gained weight significantly. Medicinal marijuana lessens the pain and disillusionment effects that result from terminal illnesses like cancers and AIDs. They therefore feel that medicinal marijuana should be offered on compassionate grounds.

Opponents
Those opposed to legalization of medicinal marijuana as a drug argue that its medical benefits have not been documented. They feel that using marijuana is very dangerous to the health of a patient. In their view, there are safer and more effective drugs that physicians can prescribe to their patients. Marijuana is known to alter the normal functioning of the body. In many cases, it has decreased the blood pressure and increased the heart rate in many patients. These fluctuations are detrimental to an individuals health. Smoked marijuana has diverse effects on an individual. It has been known to cause damage to the lungs, brain, and heart. It has also been associated with low immunity thus exposing patients to more ailments.

People smoking marijuana have been known to suffer from memory loss as well as impaired learning. Their general outlook towards life is misjudged and their perception changes too. Compounds that cause cancer have been established to exist in smoked marijuana. It has also been attributed to accidents on both the roads and work places. In the case of reducing AIDs effects, the opponents seek to differ and their argument is that marijuana causes a deficit in immunity. This may end up exposing the already immunity weak patient to pathogens.

Conclusion
From this study, medicinal marijuana could be useful to the health of a patient. At the same time, it would be absurd to overlook its negative effects to the health of a patient. The fact that it can be used as a stimulant for positive results and that it can bring relief to patients does not mean that it should be legalized since there are other drugs that can serve the same purpose. This is because long-term effects such as loss of immunity and addictions cannot be overlooked. Furthermore, medical benefits of marijuana have not been documented. Legalizing substances such as marijuana for medicinal purposes would definitely take deep evaluation of the pros and cons.

Science Article Summary Cyclin B-Cdk1 Activates Its Own Pump

In the article written by Arne Lindqvist entitled Cyclin B-Cdk1 Activates Its Own Pump to Get into the Nucleus, the author points out that the transition to mitosis involves the importation of the kinase complex into the nucleus through the modification of the activity of the nucleocytoplasmic transport machinery.

According to the author, Cdk1 is complex because the cyclin B phosphorylates hundreds of target proteins that would promote the transition from the interphase to the mitosis (Lindqvist 197).  This leads to a dramatic cellular rearrangements requiring strict coordination of the cytoplasmic and nuclear events, especially since the cytoplasmic microtubules and the nuclear chromatin have to be reorganized first before the nuclear envelope breakdown for efficient capture of the chromosomes through the microtubles (Lindqvist 197).

According to Lindqvist,
Cyclin B-Cdk1 is responsible for these reorganizations, the mechanism by which its activity is regulated spatially and temporally has been the subject of intense investigation for two decades. (Lindqvist 197)    
How the nuclear translocation is regulated has been the subject of investigation in the past.  However, it has been concluded that the cyclin B-Cdk1 is first activated in the cytoplasmspecifically in the centrosomes (Lindqvist 197).  The regulation of the nuclear translocation starts by altering its interactions using import and export factors.  However, it remains to be unknown whether the Plk1 phosphorylates a residue, which can block the nuclear export.  

In a study done by Gavet and Pines, a novel biosensor was used, phosphorylated by cyclin B-Cdk1 in order to concurrently quantitate the kinase activity and the subcellular distribution patterns while the cell progresses into mitosis.  The cyclin B-Cdk1, upon phosphorylation, binds to the phosphoylated sequence, bringing the two fluorophores closer to one another.  The decreased distance leads to the increased efficiency of the Forster resonance energy transfer or FRET.  They found out that the biosensor in live cells was phosphorylated with similar kinetics in both the nucleus and the cytoplasm during mitotic entry (Lindqvist 197).  According to them, this is definitely surprising, since most of the cyclin B-Cdk1 is in the cytoplasm during the activation, which means that a large part of cyclin B-Cdk1 resides in the nucleus, as the activation continues in late phase.

Lindqvist observes that a mechanism must be at hand to ensure the distribution of active cyclin B-Cdk1 between nucleus and cytoplasm.  In the findings of Gavet and Pines, the nuclear translocation would depend on the dramatic increase in the nuclear import of cyclin B and not on the decrease in nuclear export.  Lindqvist adds that Plk1 does not affect the rate of cyclin B-Cdk1 nuclear translocation but, rather, cannot process through the phosphorylation of the previously identified residues in cyclin B.  According to the source, Gavet and Pines found that cyclin B-Cdk1 activity itself directly regulates nuclear translocation by dramatically increasing its own nuclear import (Lindqvist 198).

There are three implications with regards to this finding first, that the cyclin B-Cdk1 is first activated in the cytoplasm second, that it is not possible to restrict active pool of cyclin B-Cdk1 to the cytoplasm, since the active cyclin B-Cdk1 will promote its own translocation third and final, that the coupling cyclin B-Cdk1 activity to its own nuclear import is an elegant mechanism that ensures the activation of the B-Cdk1 throughout the cell (Lindqvist 198).  Therefore, all these indicate that there is a possibility that other proteins also translocate at the same time as the cyclin B-Cdk1.  This directs cellular rearrangements through the redistribution of proteins during the mitotic entry.

Environmental Biology

1) Genetic Modification of Food - Agree or DisagreePost in the discussion area a website or news article relating to genetic modification of organsisms, especially pertaining to food resources. Are you in favor of or against genetic modification of food

Answer httpwww.ornl.govscitechresourcesHuman_Genomeelsigmfood.shtmlGenetic modification of food has become a controversial subject, in my opinion, without reason. By genetically modifying food items, we are taking advantage of the limited resources we have left on Earth. Through genetic modification, insect-resistant crops reduce the need for toxic pesticides, beef is healthier, eliminating loss of livestock, and medicinal applications have been identified, aiding humans even more. Genetic modification of food is a valuable innovation that will continue to help the human race for many years to come.

2) Post your views regarding bottled water. Is it better for you than tap water What do your friends and family believe What types of regulations are put on bottled water vs. tap water Do you personally buy bottled waterMarine Resource Use (21 Messages  20 New )

Answer httpwww.allaboutwater.orgregulations.html Personally, I think bottle water is an enormous waste of money, resources and landfill space. Municipal tap water is tested and has to meet rigorous standards, it is even supplemented with fluoride, something that bottled water does not normally contain. I do not ever buy bottled water, although my family and friends do, insisting it is more convenient.

One of the biggest differences with bottled and tap water is who is regulating its quality and contents. As a food item, bottled water is controlled by the Food and Drug Administration, tap water is regulated by the much stricter, Environmental Protection Agency. I would rather be able to pull up my EPA-mandated municipal water report and check the findings myself then trust a bottler as to the quality of the water.

3) Post any current information regarding the status of a resource we are using from the oceans. It could be a topic such as the population trend of a certain species, a new mineral we are mining, or the changing composition of the water.Answer Dutch dredging equipment manufacturer and dredger builder IHC Merwede says that in response to an increasing number of requests for deepsea dredging and mining application solutions, it has combined all of its activities in the sector to create a new business unit, IHC Deep Sea Dredging  Mining.

The new business unit will focus on the extraction of minerals in deep water (to a depth of 3,000m) and vertical transportation of these materials. (April 28, 2010) Source httpwww.sandandgravel.comnewsarticle.aspv112923

Indias National Institute of Ocean Technology (NIOT) will test indigenously built deep-sea mining equipment in April at a never before attempted depth of 1,100. The 15t crawler has already been tested at 500m and will eventually be used at depths up to 6,000m. It may take up to two weeks for the crawler to touch 1,100m into the deep, according to the Times of India. The test will be conducted when the Sagar Nidhi, the only vessel capable of hosting the equipment in the country, will return from an Antarctic expedition. The equipment will be used for mining the Indian Ocean for rare minerals, including magnesium, as part of a Rs 150 crore (33m) project. The equipment will be ready for large-scale mining operations after a couple of years. The NIOT is also developing a remote operable vehicle mounted with sensors and cameras to explore ocean depths at 3,000m. (March 23, 2010) Source httpwww.mining-technology.comnewsnews80078.html

Visit the following two links to learn more about Chicagos air quality.Chicagos Toxic AirHow Clean is Your AirIn the discussion area, post the closest 2 or 3 polluters to where you live and what types of pollutants they are releasing.Answer

The closest two polluters to me (area code 60644) are Chicago Castings Company at 1400 S Laramie Ave in Cicero, IL and Corn Products Argo Plant at 6400 S Archer Ave in Bedford Park, IL. Chicago Castings release manganese, lead, mercury and their components into the air. In total, they have released 9,363 pounds of these toxic elements. Corn Products Agro Plant has released 1,113,870 pounds of toxic pollutants into the air. This is composed of Sulfuric acid, Hydrochloric acid, Hydrogen flouride, n-Hexane, lead and lead compounds, mercury and mercury compounds, ammonia and dioxin and dioxin-like compounds.

5) Post in the discussion area a website or news article describing a recent development in renewable energy research.AnswerLONGMONT  Vice President Joe Biden lauded Colorado s contributions to renewable energy and alternative transportation at a speech Friday east of Longmont. Biden spoke at UQM Technologies, which makes high-power electric motors and received about 45 million in federal stimulus funds. Biden said the money provides seed capital to help UQM buy a new production plant. The Recovery Act is not just about getting us through today, Biden said. He said the stimulus dollars are helping small companies break to the front of the alternative energy world, where he said the United States should be. Biden said the United States has lost its lead in the field. Its time for us to begin to innovate again on a wholesale scale, Biden said. Among those joining Biden were Congresswoman Betsy Markey, Gov. Bill Ritter and Sen. Mark Udall. In the crowd were CSU President Tony Frank and CSU system Chancellor Joe Blake. The event drew hundreds of people. Organizers were unable to provide an immediate count. Biden said federal funds have long been used to spur innovation, from the transcontinental railroad to the Internet. We have put basic research off for too long, Biden said. I think we re back on the road. (April 30, 2010) httpwww.coloradoan.comarticle20100430UPDATES01100430027

6) Post your thoughts on a public versus private role in providing public services. Private services receive little, if any governement money, public services constantly receive money from the government. Private services tend to have more money, as they are operating for profit andor receive large donations from interested benefactors. Because of this private funding, private services have the discretion to help (or not help) whomever they choose. I think this is a dangerous thing to rely on as there is a high potential that people or services are denied. A combination of private services and public services would be best public ensures that no service is missed while private has the opportunity to provide a higher level of carservice.

7) What do you feel should be done to address the issues faced in Tijuana and San Diego Provide any updated information you can find regarding the current status of the Bajagua project.Answer The Bajagua Project was officially shot down on May 15, 2008, ending plans for a 59 million gallon sewage treatment plant in Tijuana. After the plant was built, the United States was to pay Bajagua for its operation. Instead of moving forward on the Bajagua Project, a company called PCL was awarded the 87.6-million upgrade of the South Bay Wastewater Treatment Plant in San Ysidro, California. It is important to consider the long term cost of services. United States Senator Dianne Feinstein projected that, over 20 years, the Bajagua project is estimated to cost taxpayers 539 million, compared with 331 million to upgrade the San Ysidro plant.

Vivace

In 2008 Michael Bernitsas invented a device that would help in harnessing renewable sources, the device which he named Vivace utilizes vortex induced vibration, and these forms of vibrations have been destructive in the past example the destruction of the Tacoma Bridge. According to Bernitsas these destructive forces can be controlled and converted into electric energy using his device.
The prototype device created by Bernitsas contained a submerged cylinder that is supported by a spring, when this cylinder is submerged then the vortex induced vibration enables the cylinder to move up and down, this motion is then converted into electric energy. Bernitsas also points out that vortex induced vibration also exit in the atmosphere and that scientist should work on a device that would help in harnessing these forms of energy.

His invention was based on fish motions, according to him a fish is able to swim against currents due to this form of energy, a fish will harness this form of energy and shreds it and therefore it is able to swim against strong currents.

Bernitsas tested this device in a lab whereby the device was placed in a container filled with 8,000 gallons of water, results showed that when the water circulated at a slow speed of 3 knots the device produced approximately 51 watts of electric energy. This amount of energy is enough to light 6 electric bulbs.

Bernitsas stated that a large device could produce electricity enough for an entire community, and many small devices would also be used by ship owners, who would use them to power to power batteries when their ships were anchored,

One advantage of this form of energy is that it is a renewable source of energy and also environmental friendly. Another advantage of this device is that it can capture energy in slow moving water currents, it can also be adjusted to harness energy in fast moving water currents, this is an advantage given that other techniques such as hydroelectric power generation can only harness energy at stated water currents and may be impossible to generate power when there are slow water currents.

The device is relatively cheap compared to other devices used to harness renewable energy. However energy costs of this device show that it is relatively expensive, according to him this device would produce electricity at a cost of 5.5 cents KWH, and this is relatively high compared to coal energy which costs 4 cents per KWH. However, this form of energy is relatively cheap compared to solar energy that costs 16 to 48 cents per KWH and also wind energy that costs 7 cents per KWH.

The greatest challenge of this form o0f energy is that oil prices have remained relatively low the low cost of oil makes it impossible for individuals to harness renewable sources of energy. However scientist state that as oil reservoirs decline then there will be an increase in oil prices, the high prices of oil will encourage people to utilize alternative sources of energy, in the last few years there has been increased efforts by nations to promote the utilization of green energy sources such as hydroelectric power, solar and wind energy, therefore the introduction of this device in the market will aid in promoting the use of renewable forms of energy.

Anatomy of a Flirt

Most people often become too attached to the external appearance of flirting that they do not even bother to wonder what is exactly going on within the body while a man is flirting with a woman, and vice versa. Everything that goes on outside must have had a physiological basis  this includes ones emotions, words, choices and actions such as flirtation. Flirtation is in fact the result of the coordination of the external parts of the body, certain internal organs and most of all, the hormones. This paper seeks to investigate the roles of each of these three physiological components of flirting.

External Parts of the Body Involved
We know someone is flirting first of all with his external appearance and using the different parts of his body.

Male Body Parts. Men use mainly their body probably the trunk, arms and chin (Flirtation Body Language). They usually arch, stretch or swivel their bodies when flirting, sometimes consciously but most of the time unconsciously. With their arms, they make grand gestures or they place their arms behind their head while leaning back in the chair. Lastly, they often point their chin in the air (Flirtation Body Language). It is said that often times, these gestures mean Look at me, trust me, Im powerful, but I wont hurt you. And I dont want anything much...yet (Flirtation Body Language). Other parts of the male body that may be used in flirtation include the pectoral muscles and a hairy chest (Flirtation Body Language), and perhaps biceps whose strength men usually show off during arm wrestling matches.

Female Body Parts. Among women, the parts of the body commonly used involve the eyes, lips, mouth, eyebrows, neck, back, buttocks and chest. With their eyes, women glance and make a short or sustained gaze. The lips are mainly used for smiling, licking and pouting (Flirtation Body Language). The mouth is used for giggling and laughing (Flirtation Body Language). Women use their eyebrows to make eyebrow flash or an exaggerated rising of the eyebrows of both eyes, followed by a rapid lowering (Flirtation Body Language). Women are also good at combining gestures using different parts of the body. A woman might make a coy smile while tilting her head downwardpartially avertingthe eyes and coveringthe mouth (Flirtation Body Language). Lastly, a woman may also expose her neck, force the buttocks to tilt out and up and her chest to thrust forward (Flirtation Body Language). All of these flirtatious movements with the appropriate body parts indicate the idea of submissiveness.
Aside from the body language and body parts previously mentioned, there is also body language that stops flirtation. Among women, one type of body language that stops flirtation is by orienting her body away slightly or cross her arms across her chest, or avoid meeting the mans eyes. (Flirtation Body Language)

Internal Organs Involved
Aside from the external parts of the body, flirtation involves also certain internal organs.

Brain. The area of the brain called nucleus accumbens is the part known as essential pleasure centers, and it is where oxytocin and dopamine receptors overlap (Johnson).

Several areas of the brain are also considered receptors for sex steroids (Blair). These specific areas of the brain mediate the effects both of circulating gonadal steroid hormones and of locally produced neuroactive steroids and are involved in autonomic regulation and a wide range of homeostatic regulatory processes (Blair).

Other parts of the brain involved in flirtation include the areas that respond to visual stimuli. Aside from the visual cortex, the part that is directly concerned with visual stimuli is the hypothalamus. It is believed that physical characteristics stimulatethe hypothalamus, which is followed by sensations such as elevated heart rate, perspiration, and a general feeling of sexual arousal (Fernandez). It is worth mentioning that for men, such visual cues usually refer to young women for A preference for youth is linked to a womans reproductive capacity and that healthier and more youthful women are more likely to reproduce take care of the children after birth and perpetuate the males gene (Fernandez).

Heart and Cardiovascular System. The cardiovascular system is involved in the sympathetic response of the body to the emotions associated with flirtation. The specific parts of the cardiovascular system that are affected by such emotions involve coronary function, blood pressure, and volume (Huxley). It also follows that ones heart rate and respiratory rate also go up (James), and with the rise in blood pressure that follows, one immediately gets a flushed feeling from head to toe (James).

Hormones Involved
The process of flirtation is also hormonal in nature. Aside from the involvement of body parts and certain internal organs like the heart, flirtation also involves hormones, or proteins secreted by the endocrine glands.

Flirtation usually makes up the first three stages of love lust, attraction and attachment.
During the first stage when lust takes on an individual, the hormones involved are testosterone and estrogen  in both men and women (The Science of Love).

Testosterone. It is believed that Women with high levels of testosterone are more attracted to masculine-looking men and that men, whose levels of the hormone are increased, are more attracted to feminine faces (Testosterone Levels). Testosterone is produced by the testes in males and released into the blood but the formation of which is triggered by the pituitary gland that constantly releases the hormone from puberty.

Dr. Ben Jones, a psychology lecturer at the Aberdeen University Face Research Laboratory, stated that sex drive is higher when testosterone levels are also high and that men and women in hormonal states where their interest in sex is highest show stronger attraction to high-quality - or healthy - mates although studies show that attraction is affected by fluctuations in testosterone levels (Testosterone Levels).

Estrogen. According to Ivanka Savic, Associate Professor and Senior Consultant Neurologist at the Karolinska Institute in Stockholm, When smelled, an estrogen like compound triggers blood flow to the hypothalamus in mens brains but not womens (Fernandez) and when women produce less estrogen during their menstrual cycle, their scent can be more or less appealing to males (Fernandez). Similar to testosterone, estrogen is released by the female reproductive organs, the ovaries, before they are released into the blood and the production is mediated by the pituitary gland.

Pheromones. Pheromones are known as naturally occurring substances the fertile body excretes externallyto trigger a response from the opposite sex of the same species (What are Pheromones). The protein called aphrodisin appears to be a carrier protein for a smaller molecule thatmay be the real pheromone (Pines). Since the first pheromone was identified in 1956 as a powerful sex attractant for silkworm moths (Pines), scientists have tried isolating the hormone in the laboratory. It is believed that the most direct scientific route to understanding pheromones is through genetics (Pines) for there have been a great deal of evidence pointing to the likelihood of pheromone sensation through sensor neurons.

The second stage, or the attraction stage, is governed by the actions of three main neurotransmitters namely adrenaline, dopamine and serotonin (The Science of Love).

Adrenaline. Also known as norepinehrine, this hormone, which is produced by the adrenal glands, heightens attention, short-term memory, hyperactivity, sleeplessness and goal-oriented behavior (Cupids Arrow). Based on these, one can see that somehow adrenaline treats love like it is something worth working hard for like a goal. The reason is that, when one wants to achieve his goal, his attention is also heightened and focused, and he becomes restless and sleepless. Adrenaline, because of its function in triggering excitement, is also considered a natural mood enhancer (Vasquez).

Dopamine. When the brains of couples who claimed to be in love were examined, what they discovered were high levels of the neurotransmitter dopamine (The Science of Love). It is believed that this neurotransmitter triggers an intense rush of pleasure and has the same effect on the brain as taking cocaine (The Science of Love). Dopamine was also known to cause increased energy, less need for sleep or food, focused attention and exquisite delight in smallest details of this novel relationship (The Science of Love). Just like adrenaline, dopamine is also considered a natural mood enhancer(Vasquez). Dopamine is produced in various parts of the body including the gastrointestinal tract. (Eisenhofer)

Serotonin. Serotonin is the chemical which seems to explain why when youre falling in love, your new lover keeps popping into your thoughts (The Science of Love). It is produced by the intestines and the brain (Manson) and released into the blood.

The third stage in love is attachment stage and the two major hormones involved in this feeling include oxytocin and vasopressin (The Science of Love).

Oxytocin. Oxytocin, also known as the trust hormone or cuddle hormone (The Science of Love), is actually one hormone released by men and women during orgasm (The Science of Love). This hormone is made in the hypothalamus and released through the posterior lobe of the pituitary gland into the blood. It is perhaps responsible for deepening the feelings of attachment and making couples feel much closer to one another after they have had sex (The Science of Love). Aside from this, oxytocin is also said to help cement the strong bond between mother and baby (The Science of Love) upon the simultaneous release of the hormone during childbirth.

In one experiment with voles, neuroendocrinologist Sue Carter injected this particular hormone into the brains of voles and found out that they formed bonds more quickly than usual (Johnson). When Carter and her colleagues tried injecting chemicals that blocked the receptors of oxytocin to cut off the supply of the hormone, the result was indiscriminate mating without any lasting attachment (Johnson).

Vasopressin. Vasopressin, on the other hand, is considered an important hormone in the long-term commitment stage and is released after sex (The Science of Love) although some sources say this is released by men during sex (Vasquez). Aside from the aforementioned function, this particular hormone, which is also called anti-diuretic hormone (The Science of Love), also works hand in hand with the kidneys in order to control thirst. Vasopressin is produced by the pituitary gland and released into the blood.

DARPP-32. DARPP-32, according to Rockefeller University in New York and Baylor College of Medicine in Houston, is the essential ingredient in the brain pathway that makes female mice and rats sexually receptive (McManamy). Furthermore, the works of 2000 Nobel Laureate Paul Greengard PhD, the man behind DARPP-32 have provided new insights into schizophrenia and drug use (McManamy). Indeed further research on DARPP-32 is important in determining the exact pathways of hormones in the brain when one gets sexually excited. The practical purpose of this would be to determine which pathways represent actions that must be avoided or repeated to elicit the desired sexual response in human relationships.

Conclusion
Flirtation is indeed not only made up of three physiological components that include the external organs, internal organs, and hormones. It is also a process where these three components interact with one another to produce smooth flirtation. The external body parts in both men and women help each other form suggestive movements that imply either trust or submissiveness.  The internal organs are the seat of the production of hormones and these organs initiate, direct or facilitate the movements. Lastly, the hormones produced by the brain and the endocrine glands affect the brain itself in several ways that would encourage love, sex or simply attraction. A more thorough and in-depth investigation into the physiology of flirtation may bring about breakthroughs in eliciting romances as well as perhaps in maintaining wonderful and fulfilling relationships.

Apatosaurus Brontosaurus

Sauropods were large, long-necked plant-eating dinosaurs that first appeared in the Triassic Period and proliferated in the Jurassic. They had tiny heads that logded even tinier brains, and long tails which counterbalanced their very long necks. To the infraorder of sauropods (lizard-footed) belonged the five families of Diplodocids, Brachiosaurids, Carnasaurids, Titanosaurids and Cetiosaurids. The dinosaurian species Apatosaurus belonged to the sauropod family of Diplodocids they were land-roaming giants that lived in the present day North American region for a relatively brief period during the Jurassic, between about 157 mya and 146 mya. They were among the largest animals that ever lived on the planet, and are generally considered as the largest type of dinosaur. Apatosaurus reached a length of 70 to 90 feet from the end of their tail to the mouth, with their necks alone being over 20 to 40 feet long. They were about 15 feet tall at hips, weighing around 30 to 35 thousand kilograms, or about the weight of 5 elephants. An interesting feature of diplodocoids, a part of their physiognomy, is that they had their nostrils positioned above their eyes, on the top of their heads.  

The name Apatosaurus, meaning deceptive lizard is not particularly apt for these dinosaurs, and was given for some circumstantial reasons associated with their original discovery. However, these giant creatures are also popularly known by another name Brontosaurus, meaning thunder lizard, which is a much more appropriate description of the mighty beast. The reason these dinosaurs have two names  only Apatosaurus being the scientifically accepted  is that when the first fossil of this species was discovered in latter half of 19th century, it was named Apatosaurus subsequently another skeleton of a presumably new species of dinosaurs was discovered and was named Brontosaurus, but only much later was it found out that both Apatosaurus and Brontosaurus referred to the same species. This is one of the well-known stories in the dinosaur lore. In 1870s in the United States, there was a widespread interest in hunting the dinosaur fossils. Two men worked particularly assiduously and enjoyed prolific results in the pursuit of dinosaurs Othaniel C. Marsh and Edward D. Cope. These legendary rival professors of paleontology who worked for U.S. geological survey discovered 136 dinosaur species between them, whereas there were only 9 known species before their time. In late 1870s in Wyoming, Marsh found two very large skeletons of the same animal, and named it Apatosaurus. Some time afterward, a huge sauropod skeleton was discovered by an expedition working under Cope, and it was named Brontosaurus. In both these independent fossil discoveries, skulls of the animals were not found, and therefore the resemblances were not easily noticed. Decades later, in the early 1900s, a Brontosaur skeleton was displayed in the Museum of Natural History at Yale. It came to the notice of an investigator who realized that Brontosaur was the same as Apatosaurus. According to established scientific conventions only the name first given to a species remains valid, however the name Brontosaurus was by then firmly entrenched in the public consciousness. Therefore the name Brontosaurus was not altogether discarded and was retained as a synonym. However, after a controversy in the 1980s involving a U.S. postal stamp that labeled the creature as Brontosaurus, the term has become obsolescent.

Apatosaurus  Brontosaurus was so massive that at first scientists conjectured that this animal lived in swamplands where part of its enormous body weight could be supported by the buoyancy of water. However, in the later decades as more fossils of this animal were excavated and none were found near watery areas, this conjecture was dropped. Their skeletons were also not particularly adapted for living in water. Apatosaurus could have been a grazing animal that lived and moved in herds. However, it could also have been a solitary animal, because fossils of Apatosaurus were so far found only in isolation and not in clusters. However, fossil tracks of sauropodian herds were found.  These animals may not have had much difficulty in finding food because the terrain was abundantly covered by plants at that time. However, according to some estimates, an Apatosaurus might have needed to consume in excess of one ton of plant material every day. To procure such massive amounts of food, these animals might have routinely expended considerable time and effort. And in the process they would have significantly reshaped the landscape around them.  They had peg-like teeth which could strip leaves from plants, needles from tree-tops and so on, but these teeth could not chew. Therefore it could be possible that these animals swallowed stones along with their food, which could then help break up the ingested food, a strategy followed by some birds.

A special characteristic of diplodocids in terms of their bone structure is that they had hollows in their vertebrae. Nevertheless, they were strong enough. The cervical vertebrae of Apatosaurus were stronger and shorter than the other diplodocids, for example Diplodocus. Diplodocids had a deep and heavy midsection. Apatosaurus had huge bones in the midsection of their bodies. Their ribs were elongated. Apatosaurus did not have a muscular diaphragm, and had avian type lungs. The estimated total lung volume is about 1400 liters with a dead-space volume of 184 liters.

Owing to their fantastically huge size, they had little to fear from predators. Apatosaurus enormous tapering tail could serve as a whiplash against any possible attackers. Their main enemy was Allosaurus, which was a ferocious meat-eating dinosaur but very much smaller in size. If indeed these diplodocids traveled in herds, their collectivity could have served as an additional protective measure. However, the speed of their mobility was rather restricted. They had four huge limbs that could support their massive body weight and they walked on all four legs, but understandably enough the adults of the species could only lumber along. The hind limbs of these animals were larger and longer than their forelimbs. They could walk up to 10 miles or 16 kms a day. Their long tails would stand fully stretched out as they walked, in order balance their bodies. The need to hold their tails up also arose because dragging such a massive tail on ground could have got it entangled in the vegetation or caught up in the cracks of rocks. Occasionally the tail could have been used as a third limb to support the weight of the body when these animals raised their heads and forelimbs limbs up to grab leaves higher up. The younger ones of the species could become easy prey for Allosaurus or other theropodian predators such as Ceratosaurus, but the juveniles exhibited more agility than the mature ones. Footprint fossils (known as trackways) of Apatosaurian juveniles discovered more recently suggest that while growing, Apatosaurus could run on their hind legs in the manner of some species of lizards today.
These sauropods grew to their full size rather rapidly. It might have taken an Apatosaurus only 15 to 20 years to put on its full body weight of 25 to 35 tons. The average life span of these animals could have been around a 100 years. Scientists still do not have an explanation as to why Tyrannosaurus Rex, Apatosaurus and other huge varieties of dinosaurs were so large and heavy. But it is clear that to support such gigantic beasts the land must have been extraordinarily rich in vegetation.
Diplodocids were formerly thought to have held their heads high and necks straight up so that they could easily graze from tree tops. But this picture presented some problems because it would not be possible for the blood flow to reach up to the brains in order to oxygenate it if these animals held their long and slender necks nearly vertically up. Accordingly, their necks would have been typically positioned at a 45 angle to their body while grazing from tall trees. The structure of neck bones also would not have allowed an Apatosaurus to bend its neck further back. In a resting position, the necks would have normally assumed a more comfortable angle, which is being parallel to the ground or actually leaning downwards. Diplodocids generally tended to hold their necks horizontally. Also, these extremely long diplodocid necks had very limited mobility.

Incidentally, in whatever position the neck was placed, pumping blood along its enormous length all the way up to the head and the brain would have presented a great challenge to the animals heart. These animals were walking and grazing much of their waking time, and their brains would be situated many meters high above their hearts for many hours a day. Therefore, Apatosaurus blood pressure should have been around 4 times higher than humans, and their hearts would have been very powerful machines indeed to sustain such an enormous blood pressure.  

Considering that these diplodocids grew at phenomenal rates, growing 20 kg a day and achieving 90 of their adult size only after the first 10 years of their life, they would have required a large amount of energy to maintain their growth rates, and their physiology could have been homeothermic. Large-size sauropods in general could have been inertial homeotherms. This means that once they were heated by either external environment or internal processes they could maintain this temperature for a long time by fermenting bacteria harbored in their spacious guts. The fact that the surface area  volume ratio was lower in sauropods compared to many other species of dinosaurs would have also helped them maintain the body temperature. In case of overheating, heat venting could have been achieved by means of long necks, tails and legs.

Sauropodian eggs were huge, up to one foot in width. It is likely that sauropods did not take care of their eggs.

The states of Wyoming, Colorado, Utah and Oklahoma yielded the most abundant fossils of Apatosaurus as well as other sauropods so far. These beasts may also have lived in a much more extensive area further north and south. Four subspecies of Apatosaurus have been identified ajax (mostly in Colorado), excelsus (Utah and Oklahoma), louisae (mostly in Colorado), yahnahpin (mostly in Wyoming). Today, Brontosaurus still remains one of the most familiar names of all dinosaurs, perhaps next only to Tyrannosaurus Rex.