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 virus might become more infective

The swine-origin influenza a (HINI) virus that is responsible for the current pandemic clearly has the ability to leap from one human to another. The chain of transmission, aided by global air travel, has taken the virus from Mexico among humans in late march to countries around the globe.

Yet scientists who have been studying the virus say that changes is its genetic makeup could make it even more efficient at spreading and infecting people. Viruses are mostly genetic material packaged in protective coating and have no way of reproducing by themselves. So they are obligate parasites that must enter and take over a living cell, using the latter to make copies of themselves. Flu viruses use a protein on their outer surface known as hemagglutinin (HA) to gain entry into cells. Infection begins with the viral HA latching onto a receptor molecule on a cell’s surface.

Receptor molecule:
The receptor molecule has sialic acid linked to a sugar. Human-adapted flu viruses attach themselves to receptors with an ‘alpha-2-6’linkage between sialic acid and the sugar. bird flu viruses, on the one hand, bind to receptors with an ‘alpha-2-3’linkage.the alpha-2-6 receptors are found on cell along the human upper airway, such as the nose and throat.

Flu viruses that colonise these cells are then able to spread through tiny droplets that spray out when an infected person sneezes orcoughs.such iruses get transmitted much more easily and rapidly among humans. The HA of the amino acids necessary for”high affinity binding” to the alpha-2-6 receptor, according to research by ram sasisekharan and his colleagues at the Massachusetts institute of technology(MIT)that was published in nature biotechnology last month Dr.sasisekharan is Edward hoop taplin professor and director of the Harvard-MIT division of health sciences and technology.

Even so, the binding affinity of the swine-origin virus to the alpha-2-6 receptor was less than that of the 1918 HINI virus that caused the worst flu pandemic of the 20th century, says a study from the MIT group and a team of scientists from the U.S.centers for disease control and prevention (CDC) that was published recently online by science.

The efficiency with which flu viruses are able to spread through droplets is also affected by their ‘polymerase basic protein 2’ (PB2).”A single amino acid substitution from glutamic acid to lysine at amino acid position 627 supports efficient influenza virus replication at the lower temperature (33 degree C) found in the mammalian airway and contributes to efficient transmission in mammals,“ the MIT and CDC scientists pointed out in their science paper.

Glutamic acid
But in contrast to the seasonal strains of HINI that in fect humans, the swine-origin HINI virus has glutamic acid at that position in its PB2, which too affects the efficiency of the latter’s droplet transmission. given the propensity for the flu virus to develop mutations in its genome as well as for it to swap gene segments with other flu viruses(a process known as reassortment),it is possible that the swine origin virus could become even more adept at human-to-human transmission.

“Based on this study, we anticipate that mutations in the (receptor-binding site0of HA combined with mutation/reassortment of PB2 would increase the transmission efficiency of the 2009 HINI (swine-origin virus),” observed Dr.Sasisekharan in an email to this correspondent. “We need to pay careful attention to the evolution of this virus,” he said in a press release issued by MIT.

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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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What is pneumonia?

Pneumonia is a contagious disease that occurs in the human body due to the inflammation of bacteria, virus, or fungus in the lungs. It can also occurred by inhaling vomit on certain chemicals. It is a serious illness that affects one out of every 100 people each year. People of all ages are highly suffered from this disease including older adults, babies, infants; young children are all at highest risk. It can weaken immune system and pass to ill the lungs. Pneumonia can be spread to the people through the air of bacteria. People with pneumonia may also experience fever, difficult or painful breathing, painful and productive coughs.

There are several causes of pneumonia. Although most cases of pneumonia are caused by a viral, bacterial or fungal infection and also by the obstruction of bronchial tubes. It can transmit by coughs and sneezes, and by hand washing. These can all easily spread the bacteria from the infected person to other human body. Even if the person is supposed to share drinking glass and eating utensils can also have a high chance to stick with the disease of pneumonia. People can also lower your chances of guessing pneumonia by staying away from cold, measles, or little chicken pox.
Inhaling of gasoline, lighter fluid, kerosene, liquid polishes, waxier can result in pneumonia rapidly. It can all lose out the elasticity of the lungs and start to spoil the life. But it can be treated well by the efficient physicians. The treatment can vary from person to person depend upon the cause and severity of the pneumonia disease. The treatment includes antibiotics to bacterial pneumonia but ineffective in viral pneumonia. It can be treated well with antiviral medications. Antibiotics may be prescribed when bacteria pneumonia occurs.

The most important signs and symptoms of this contagious disease includes fever, chills, nausea, vomiting, diarrhea, feeling short of breath, slow or rapid breathing, cough with yellowish and greenish mucus, severe pains along the chest wall and much more cigarette smoking also increases the risk of pneumonia. People with AIDS can susceptible with this health disorder. People who have received tissue of organ transplants can develop this pneumonia. It is also more common in people who have had a stroke, Parkinson’s disease or previous throat surgery. The symptoms include headache, loss of apprise, fatigue, confusion, especially in older people, excessive swelling, unexplained weight loss, worsening respiratory symptoms, shaking chilies.

Pneumonia can be prevented by hand washing after blowing the nose, going to the bathroom, diapering and before eating or preparing foods. It is better to quit or avoid smoking habit to decrease the risk of this disease. People can also wear a mask when they clean dusty or muddy areas. It helps to prevent with this disease. People with pneumonia can travel from mild to severe and even be deadly.

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Treatment for food poisoning

Food poisoning is more common to humans. It occurs because of the consumption of food with the presence of bacteria, parasites, viruses, toxins or chemicals. It occurs at any stages of both men and women. The symptoms of this severe illness include vomiting, diarrhea, headache and adnominal cramping. Most of the people recover on their own from food poisoning. But some of the patients have severe discus and require hospitalization for further treatment. It is a serious illness that may lead to death. So it is essential to visit physician if anyone experience food poisoning.

There are several treatments to give up food poisoning. (First, one should concentrate on healthy food habits for being healthy and wealthy). The treatment can vary from person to person because it depends on the type of contaminant and the amount eaten. The patient may also experience fever, chills, bloody stools, and dehydration. It is important to prepare food clean and hygiene for food handless. They must wash their hands before and after cooking. This type of approach may reduce the risks of food poisoning.

Food poisoning can be treated at home when the patient is not affected seriously. They are not supposed to eat solid food and encourage drinking plenty of fluids. It is also best to avoid alcoholic, caffeinated and sugary drinks. It is reliable to recommended doctor for children with food poisoning. They can also always treat under doctor care. This can also damage immune system and nervous system and may encourage some diseases.

Medically it can be treated well under antibiotic treatment and aggressive dehydration. Anti-vomiting and diarrhea medications may also be given to the patients of food poisoning. Antibiotic are rare treatment for food prisoners. In some issues, antibiotic treatments can worsen the bad condition. Aggressive treatment is more essential to mushroom poisoning or eating foods contaminated with pesticides. These can be very serious and must require intensive care in the hospital.

Food poisoning can be prevented under the shopping of healthy items. One should concentrate on cooking raw meat, poultry and other food items. It is because that food particle may contain bacteria. It cannot be seen, smelled of tasted, which may present on any food. It is safe to store food in refuge sates and should check out the temperature of every food particles. It is fine to use cooked leftovers within four days. Safe cooking and safe storage of foods may reduce food poisoning of people.

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