Tool bag may reach Earth or burn up

Remains of a tool bag dropped by a NASA astronaut during a space walk last year are expected to reach the Earth surface later on Tuesday. The bag was expected to reach the Earth on July 25, but then scientists recalculated the date. However, specialists still cannot say where exactly this can happen.

“Tools for work in outer space are made of special high-alloy steel, that is why it is quite probable that some fragments will not burn in Earth atmosphere, but will reach the Earth surface,” said an expert. However, the over whelming majority of debris and space garbage burn as they enter the atmosphere.

Endeavour’s Heide Stefanyshyn-Piper lost her grip on the tool bag during a space walk on November 18, 2008. NASA reported then that the backpack-sized bag was one of the biggest objects ever lost by astronauts.

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How cats have their way

Cats coax their owners into giving them what they want with a special purr that blends their normal soft, low sound with a high-pitched element that is hard to ignore, British researchers said recently.

The high- frequency part is similar to a cry or a meow, and cats incorporate this into their normal, contended purr to exploit the nurturing instincts of humans for their own needs – usually to get fed, according to scientists.

Lead author Dr Karen McComb of Sussex University in southern England said she initiated the study after being repeatedly worken up in the mornings by her own cat, Pepo.

“I wondered why this purrings sounded so annoying and was so difficult to ignore. Talking with other cat owners, I found that some of them- including co-author Anna Taylor – also had cats who showed similar behaviour,” she said.

McComb and her team tested human responses to different purring types, including “solicitation” purrs- which included the high-frequency element and were made by hungry cats- against “non- solicitation” or normal purrs.

“When humans were played purrs recorded while cats were actively seeking food at equal volume to purrs recorded in non-solicitation contexts, even those with no experience of cats judged the solicitation’ purrs to be more urgent and less pleasant,” she said.

When the team re-synthesized the purrs to remove the embedded cry, the urgency ratings decreased significantly.

McComb concluded that the cats were using the special purr to make their views known without risking irritating humans with an overt meow. However, this solution appears only to work in cats living one-on-one with their owners—cats in large house holds usually have to meow to be heard.

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Swine flu: race to produce vaccines by the end of the year

Vaccines against swine flu have already been developed in laboratories around the world, but will not be readily available until at least October and perhaps as late as December, according to one manufacturer.

Around the world pharmaceutical companies have been producing vaccine strains for at least a month. Some are in the experimental stages, while others are approaching the need for clinical trials. However they are “by no means” ready yet, according to the World Health Organisation.

First batches:

The U.K.’s Department of Health has said it has signed contracts to supply enough vaccines for the entire British population and expects the first batches to arrive in the “early autumn.”

In April, the race to produce a successful vaccine against HINI began in earnest, when, under orders from the WHO, institutes in the U.K., the U.S., Japan and Australia began work to produce a “seed strain” of the virus, which could then go on to provide for a vaccine.

In the U.K., scientists at the Health Protection Agency’s National Institute for Biological Standards and Control (NIBSC) began work on a strain isolated fro a patient in the U.S Using a technique called “reverse genetics” the scientist took the genes that make the outer coating of the swine flu virus and then attached them to a harmless human virus known as PR8.

This reconstructed virus is considered safe for humans and will trigger an immune response that protects people against the swine flu strain.

By 28 May, NIBSC had completed its work. It sent the starter virus out to manufacturers, including GSK and Baxter.

The next step was to develop the virus and grow it inside chicken eggs, to produce it in vast quantities. The production involves refining it further and then, once the experimental phase is finished, conducting clinical trials of the vaccine.

It has been reported that CSL, a biopharmaceutical in Melbourne, Australia, has created an effective vaccine, but it is awaiting human trials to fix upon the correct dosage.

On 14 July, a spokesman for GSK said the company had started production of the vaccine last “final vaccine” to be available from between four and six months from then. He said that the clinical trials would happen “before autumn.”

Clinical trials:

Commenting on when vaccines would be ready for use, Marine-Paule Kieny, director of the Initiative for Vaccine Research, at the World Health Organisation, in Geneva, Switzerland, said: “They are produced but they are by no means ready to be licensed yet.”

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Human sperm created, claim scientists

Scientists have claimed to have created human sperm, which they say could lead to new treatment for male infertility.

The sperm was grown in a laboratory in Newcastle, England, from embryonic stem cells. Led by Professor Karim Nayernia, the researchers developed a method of growing early-stage sperm from human embryonic stem cells by using retinoic acid, a vitamin A derivative.

They found that about 20 per cent of the cells produced early-stage sperm cells or spermatagonia and, after further culture, they could see a number of cells continue to split and divide.

The breakthrough, they said came when some cells continued to grow, elongating and growing a tail that caused them to move, and forming recognizable sperm cells.

Professor Nayernia of Newcastle University and the North East England Stem Cell Institute (Nesci) described the cells as “fully mature, functional” sperm, which he called In Vitro Derived (IVD) sperm.

‘Important development’

He said:

“This is an important development as it will allow researchers to study in detail how sperm forms and lead to a better understanding of infertility in men – why it happens and what is causing it.

“This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own.

“It will also allow scientists to study how cells involved in reproduction are affected by toxins, for example why young boys with leukaemia who undergo chemotherapy can become infertile for life and possibly lead us to a solution.”

The scientist, who created mice sperm six years ago, using similar techniques, said he used four criteria to determine whether the cells he produced were sperm.

They were: the presence of proteins specific to sperm, one of which is located in the tail and very important for activating egg division; chromosome analysis, which showed that the sperm produced contained 23 chromosomes or half of the chromosome set- this is specific to sperm cells; the shape of the sperm, which has a tail and a head; and finally the movement of the sperm – “we could clearly see the movement of the sperm using the tail”.

But his findings, published in the academic journal stem cell and development, were met by a barrage of criticism from other scientists, who said further research was needed to determine the authenticity of his claims.

Dr. Allan Pacey of the University of Sheffield, England, said: “As a sperm biologist of 20 years experience, I am unconvinced from the data presented in this paper that the cells….. Produced by Professor Nayernia’s group can be accurately called ‘spermotozoa’”.

After watching a video clip of the cells, he said that while they possessed “some of the distinctive genetic features and molecular markers seen in sperm,” there were other characteristics of human sperm that were not described in the paper, while the footage “did not have sufficient resolution” for him to properly assess how the sperm was moving, another indicative factor of sperm behaviour.

Professor Azim Surani, a specialist in physiology and reproduction at the University of Cambridge, observed that the cells should be tested to find out how they developed inside an animal egg.

“These sperm-like cells made in a dish from embryonic stem cells are a long way from being authentic sperm cells,” he said.

Professor Robin Lovell Badge from the U.K.’s Medical Research Council Institute of Medical Research said, “The findings need much better evidence that such in-vitro derived sperm are normal.” But he added that any progress by the team “will be very important for research” and “ultimately, although definitely not yet, fertility treatments”.

Professor Nayernia responded by saying that his research paper was clearly labeled a “proof of principle,” which concluded that it was in its early stages and further research was needed.

He added that his findings would not lead to human beings being produced “in a dish,” but were rather “a way of investigating why some people are infertile and the reasons behind it.”

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Cot death linked to mood chemical

London: A new research has offered fresh insights into the origins of sudden infant death syndrome or SIDS-the risk of cot death is higher in babies who have an imbalance of a “mood chemical” in their brain.

Crib or cot death is the leading cause of death during the first year of life. In their study on mice, a team of scientists in Europe has found that an imbalance of brain-signaling chemical known as serotonin, which regulates mood, can kill infant animals; in fact, they have identified a possible genetic cause of this imbalance. if the genetic link is confirmed, the research could lead to ways of identifying babies at risk, the times reported.

However, according to them, the abnormalities could also be a result of environmental factors particularly parental smoking.”Ultimately, we hope it will give new idea to diagnose babies at risk for SIDS,”enrica audero, who led research in Italy, said.

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Now, shoes that can predict fall

Elderly people can now heave a sigh of relief-thanks to scientists who have developed a footwear which can predict when one is going to fall.

Called the ishoe, it is actually a high-tech insole fitted with a number of computerized sensors that can monitor balance through the soles of the feet. By checking which parts of the foot are bearing the most pleasure, the “smart” insole works out the risk of a fall, the Daily mail reported.

According to the scientists at the Massachusetts Institute of Technology, as falls are becoming an increasing problem for aged people, the footwear could slash the number of hip fractures in the elderly.

Though the experimental device is able only to relay, the results to a computer for doctors to analyse. And,if the patient is at risk, they can be referred for strength training such as”tai chi” to reduce their risk,they say.

But lead researcher Erez Lieberman hopes to install an alarm system that can warn of an impending tumble. He and his team, who developed the ishoe, are currently testing it on 60 elderly people. Help the aged, an organization for the elderly, has appreciated the work of scientists.

“Falls are a huge problem. One person dies every five hours as a result of a fall. If this invention can identify those most at risk it would be very helpful. But we also need the services in place to support these people once they are identified” its senior police officer charlotte potter said.

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Food and violent behaviour

It is quite interesting to know that there is a well connection between food and mood disorders of humans. Diet is important not only for physical health, but also for better mental health. Nutrition can play an important role to manage many kinds of difficulties in behavior, learning and mood. But most of the people are not aware though it has scientific evidence about nutritional and behavioral disorders.

A person who encourages his diet with lots of fish, especially sardine, will allow him to keep distance with criminal behavior. Similarly, intake of fish oils can bring down violent moods to the consumers, says study. The plain and simple fact is that small changes in nutritional status can bring healthy benefits in the long term that can also reduce the criminal tendencies. People’s mood and behavior are mainly dependent on the nutrients the brain gets from the diet. It is essential to concentrate on the diet for general well-being.

Research says that individuals eating an unhealthy diet are most likely to commit suicide that others. A person who intakes a lot of fresh fruits and vegetables each day he can able to control his mood and behavior that can also meet the number of disciplinary incidents in his life. He is also supposed to cut down the use of sugar and soft drinks which may encourage obesity. People who failed to keep levels of sugar in their bloodstream are more likely to be violent and aggressive. But it is essential to maintain the right level of sugar in the body.

People can improve the right quality of life by incorporating right food at the right time. The right kinds of nutrients allow functioning the whole body correctly and perfectly. Thus helps to stick with prosperous life. Doctors usually recommend a balanced diet, which would include stuff from all the food groups in the limited portions.

Some scientists say that food habits do not have any impact on behavior. They said that psychological and sociological reasons should not be overlooked. However, it is important to eat healthy to meet the nutrient needs for general well-being.

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Direct and Indirect Calorimetry

Direct calorimetry measures the amount of body heat released by a person. The subject is put into an insulated chamber, often the size of a small bedroom, and body heat released raises the temperature of a layer of water surrounding the chamber. A kcal, as you recall, is related to the amount of heat available to raise the temperature of the water. By measuring the water temperature in the direct calorimeter before and after the body releases heat, scientists can determine the energy expended. This method resembles the bomb calorimeter method for measuring the energy content in food.

Direct calorimetry works because almost all the energy used by the body eventually leaves as heat. However, few studies use direct calorimetry, mostly because of its expense and complexity.

For indirect calorimetry, instead of measuring heat output, the most commonly used method measures the amount of oxygen a person uses. A predictable relationship exists between the body’s use of energy and oxygen. For example, when metabolizing a mixed diet of carbohydrate, fat, and protein-a typical blend of nutrients the human body needs 1 litter of oxygen to yield about 4.95 kcal of energy.

Instruments used to measure oxygen consumption for indirect calorimetry have great versatility. They can be mounted on carts and rolled up to a hospital bed or carried in backpacks while a person plays tennis or jogs. There are even new hand held instruments. Tables showing energy demands of exercises rely on information gained from indirect calorimetry studies.

Another approach to indirect calorimetry uses stable isotopes of oxygen and hydrogen. In this method, a person consumes isotopically labeled water. A technician measures the 2H2o and the H2 18O later that arises in body fluids, such as urine. Using the difference between the decline in the amount of 2H2O compared to H2 18O over a week or so and some mathematical formulas, total carbon dioxide (CO2) output per day can be estimated. This method works because 2H diffuses throughout the body’s water and the 18O diffuses throughout both the body water and bicarbonate (HCO3) stores. 2H is then only eliminated from the body via water production, while the 18O is eliminated both as water and carbon dioxide originally associated with bicarbonate. This ultimate estimate of CO2 output is used to calculate energy expenditure, just as id done with oxygen use in indirect calorimetry. 2H and 18O are stable isotopes of hydrogen and oxygen (therefore, they are nonradioactive); special instruments can measure them in body-fluids. This stable isotope method is quite accurate but also very expensive. It is the basis for setting energy needs for humans.

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