Published: Wednesday 30 September 2009

Never too late

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Flowers are more resilient than they appear. They shoot up against all odds. The credit goes to genetic matter called microRNA that inhibit protein formation crucial to flowering in young plants. External cues like sunlight make them flower. But in the absence of cues, too, flowers do blossom; the activity of microRNA decreases with age ensuring enough flowering proteins are produced before the plant dies (Cell, August 21).

An anti-cancer bacterium

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Salinispora tropica
Cancerous cells divide and grow much faster than healthy cells. As a consequence, cancer cells accumulate larger quantities of waste. The waste is managed by protein molecules called proteasomes which are a cell's sanitation workers. In their absence a cell will choke on its waste and die. Cancer researchers have found a molecule produced by a marine bacterium (Salinispora tropica) that can choke the cancer cells by disabling their proteasomes. Drugs manufactured to target cancerous cells end up hurting healthy cells as well. In this case, the healthy cells were found to better resist the drug thus restricting its impact mostly on the cancerous ones (Journal of Medicinal Chemistry, August).

Its a tough one

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Plastic does not decompose. It stays intact in a landfill for hundreds of years. This makes it difficult to get rid of one of the most toxic pollutants ever created by man. A team found it does decompose in oceans, and with surprising rapidity. But this is not good news. The team simulated the temperatures and other conditions that leads to plastic's breakdown in the ocean and found that it adds two very toxic compounds to the water, namely, bisphenol and styrene. These are not found naturally and while bisphenol disrupts hormone functions, styrene is a potent carcinogen. Millions of tonnes of plastic debris enter the oceans every year. (American Chemical Society meeting, August)

The sun has flares

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The temperature of the sun's surface is 5,427 C. Yet it is millions of degrees cooler than the sun's outer atmosphere. Astrophycists probing into the mystery found the answer in sudden bursts of energy called nanoflares. These can also be blamed for influencing changes in X-ray and UV radiations which enter the earth's atmosphere and disrupt communication signals like radio and electrical transmissions (International Astronomical Union General Assembly, August 6).

The nod to kill

The immune system releases a protein molecule when the respiratory system is attacked. This protein, called NOD2, can recognize the influenza A and the respiratory tract infection virus. Microbiologists say it is more than a sensor: the immune system cannot attack the viruses unless the protein orders it to do so. In tests, mice lacking the sensor died of respiratory infections in 10 days. This molecule can be used to develop drugs to boost the immune system. In people with lowered immunity such diseases are life-threatening (Nature, August 23

What makes her fat

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Active levels of testosterone in the blood of menopausal women causes visceral fat to accumulate; age is not the culprit as was believed. Earlier studies have shown that increase in visceral fat is a risk factor for acute coronary diseases and strokes. Female reproductive organs produce testosterone in low quantities. Although a male hormone, it helps women maintain muscle and bone strength. During the menopause transition period there is hormonal imbalance leading to an increase in the blood level of testosterone (Obesity, August 20).

Dinner at 7?
Of the various tricks that parasites use to fool host immune systems, here is a new one: the parasite that causes leishmaniasis (kala azar), coaxes the immune system to feed it instead of killing it. When an infected sandfly bites a human it transfers the parasites along with a sticky gel produced by them. Immune cells are then
released at the site. These cells usually produce nitric oxide to kill the pathogens. In this case, the researchers found they produced polyamines--food for the parasite. On further research, they found the sticky gel responsible in helping the parasite establish this connection with the immune cells. The same gel protects the parasites from the fly's defences. (PLoS Pathogens, August 20)

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