Science and Technology - Briefs

 
Published: Saturday 30 June 2012

MICROBIOLOGY
Algae against malaria

imageMalaria affects billions of people worldwide. No cheap vaccine is widely available for it. Now scientists have developed a low-cost method of producing malarial vaccine using algae. The potential vaccine hinges on an edible green microalgae called Chlamydomonas reinhardtii, which was modified to make a protein that is produced by the malarial parasite during its life stage in the mosquito gut. This protein, when injected inside a body, stimulates the production of antibodies that can block the parasite’s reproductive cycle in a mosquito’s gut, preventing the transmission of the parasite from mosquitoes to other hosts. Laboratory mice injected with the protein could successfully fight malaria. PLoS ONE, May 16

imageASTROPHYSICS
Gravity helps find planet

An unseen planet outside our solar system has been discovered—using a 150-year-old technique which helped find Neptune. Using NASA’s Kepler Space Telescope, scientists observed the gravitational tugging of the hidden planet, KOI-872c, on another known planet orbiting the sun-like star KOI-872. The technique had earlier led to Neptune’s discovery in the year 1846, via its gravitational influence on Uranus. This is the first time the technique has been successfully used to identify a planet outside our solar system. KOI-872c orbits its sun every 57 day. Science, May 10

imageCHEMISTRY
Choking fungicide

Chlorothalonil, one of the world’s most common fungicides, is killing freshwater organisms. Even at levels below those deemed safe by the US, chlorothalonil—used on food crops—killed amphibians, algae, and aquatic plants. The loss of these organisms freed the algae from predation and competition, which eventually resulted in algal blooms that were similar to the effects of eutrophication. Though some species recover from the assault, the ecosystem fundamentally changes, say scientists who conducted the study on tanks used to mimic pond conditions. Ecology Letters, May 16

TECHNOLOGY
Cheap diabetes test

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A newly developed inexpensive device for testing diabetes could prove to be godsent for rural India where poverty limits availability of healthcare. The device detects glucose levels in the urine instead of blood. The sample is injected into a container and one end of a paper strip is dipped into it. The urine travels up the strip and onto a pad that contains enzyme glucose oxidase. The glucose in the sample reacts with the enzyme to produce hydrogen peroxide, which is detected by the electrode below. The strip runs down to a sink, which pulls liquid through the whole system. This test results are similar to those from commercially available clinical instrument. Analytical Chemistry, May 1

imageZOOLOGY
What makes it colourful?

They are prized for their beautiful plumage but what makes birds’ feathers so colourful was not known. Now, an X-ray analysis of the structure of feathers from 230 species has revealed the three-dimensional nanostructures responsible for the colours in feathers. While many birds produce colours using pigments, there are no blue pigments in birds, while green pigments are rare. Birds have evolved to produce shorter and middle wavelength colours such as violet, indigo, blue and green, structurally by the scattering of light photons by nanoscale sub-surface features in the feather called biophotonic nanostructures. The finding could inspire new photonic devices. Journal of the Royal Society Interface, May 9

imageECOLOGY
Velcro petals to cling on

Garden flowers like petunias and roses have evolved Velcro-like cells on petals that help bees grip flowers, especially when the wind is blowing. Conical cells on the petals allow bees to maintain a foothold while being shaken around. The insects hold on by locking their claws into gaps between the cells. Using a shaking platform to mimic the way flowers move in the wind, a group of bumblebees were offered the choice of a normal plant (petunia) and a mutant strain without conical cells. As the speed of shaking increased, the bees increased their preference for the conical-celled flowers. Functional Ecology, May 29

CHEMISTRY
Buckle up

Adding traces of water can tremendously speed up chemical reactions. Without water heat is needed to speed up a reaction. Though scientists have known about this property, they lacked a fundamental grasp of how it happens. Scientists recently studied this on a common catalyst, iron oxide. They found that the most minute amounts of water make hydrogen diffuse 10,000 trillion times faster on iron oxide than it would have diffused in the absence of water. Science, May 18

imageBIOLOGY
A pathway to remember

Scientists have long identified areas of the brain responsible for initiating rhythmic movements like swimming, but the precise neuron-by-neuron pathway in any vertebrate was not unknown, till now. After studying movements of tadpole of frog Xenopus, it was found that the pathway to initiate swimming consists of four types of neurons. By touching skin on the head of the tadpole, scientists identified nerve cells that detect the touch, two types of brain nerve cells which pass on the signal, and the motor nerve cells that control the swimming muscles. The finding could help understand initiation of locomotion in people and have implications for treating disorders like Parkinson’s. Journal of Physiology, May 16

imageLIFE SCIENCES
Sunscreen blamed

An ingredient present in most sunscreens could be tied to a higher risk of developing endometriosis, a painful condition in women in which cells from the lining of the uterus flourish outside the uterine cavity. Scientists have found that a type of benzophenones (BP), a group of chemicals, can pass through the skin and mimic the effects of the female sex hormone estrogen. They measured levels of five kinds of BP in the urine of 625 women for endometriosis, a problem which leads to irregular bleeding and pain, and found higher levels of one BP called, 2,4OH-BP. Women with the highest level of this chemical (65 per cent) had the greatest likelihood of affliction. Environmental Science & Technology, April 17

HEALTH
Sedentary lifestyle fuels cancer threat

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Cases of cancer are likely to rise by 75 per cent by 2030 worldwide due to sedentary lifestyle. Researchers used four levels (low, medium, high and very high) of the Human Development Index (HDI)—an indicator of life expectancy, education and GDP—to analyse cancer patterns in 2008 and produced future scenarios for 184 countries. They found nations with low HDI will see high rates of infection-linked cancers, such as cervical and stomach. Those with very high and high HDI, such as the US and Australia, will be afflicted by cancers associated with smoking and diet, like breast, lung and prostate cancer. Since medium HDI countries like India are turning to Western lifestyles, they are likely to be affected in a similar manner as high HDI nations. The Lancet Oncology, June 1

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