Month: August 2014

WASHINGTON (TIP): Scientists using mission data from Nasa’s Cassini spacecraft have identified 101 distinct geysers erupting on Saturn’s icy moon Enceladus. Their analysis suggests it is possible for liquid water to reach from the moon’s underground sea all the way to its surface.

Over a period of almost seven years, Cassini’s cameras surveyed the south polar terrain of the small moon, a unique geological basin renowned for its four prominent “tiger stripe” fractures and the geysers of tiny icy particles and water vapour first sighted there nearly 10 years ago.

The result of the survey is a map of 101 geysers, each erupting from one of the tiger stripe fractures, and the discovery that individual geysers are coincident with small hot spots. To determine the surface locations of the geysers researchers employed the same process of triangulation used historically to survey geological features on Earth, such as mountains.

When the researchers compared the geysers’ locations with low-resolution maps of thermal emission, it became apparent the greatest geyser activity coincided with the greatest thermal radiation. Comparisons between the geysers and tidal stresses revealed similar connections. The researchers then compared the survey results with high-resolution data collected in 2010 by Cassini’s heatsensing instruments.

Individual geysers were found to coincide with small-scale hot spots, only a few dozen feet (or tens of metres) across, which were too small to be produced by frictional heating, but the right size to be the result of condensation of vapour on the nearsurface walls of the fractures.

This immediately implicated the hot spots as the signature of the geysering process. “Once we had these results in hand, we knew right away heat was not causing the geysers, but vice versa,” said Carolyn Porco, leader of the Cassini imaging team from the Space Science Institute in Boulder, Colorado, and lead author of the first paper. “It also told us the geysers are not a near-surface phenomenon, but have much deeper roots,” Porco said.

The researchers concluded that the only plausible source of the material forming the geysers is the sea now known to exist beneath the ice shell. They also found that narrow pathways through the ice shell can remain open from the sea all the way to the surface, if filled with liquid water.

Each time you eat chicken, you could also be consuming a cocktail of antibiotics. A lab study released by Centre for Science and Environment (CSE) found antibiotic residues in 40% of chicken samples bought from outlets in Delhi and NCR. Antibiotics are substances that can destroy or inhibit the growth of micro-organisms. They are widely used in prevention and treatment of infectious diseases.

1: Six antibiotics tested from there antibiotic classes – tetracyclines, fluoroquinolones and aminoglycosides.

2: Each chicken sample analyzed thrice.

3: Antibiotics found in all tissues tested- muscles, liver and kidney.

4: No significant difference in residues in different parts of chicken. 5: More than on antibiotic found in 17% chickens.

Why this could be dangerous?

1: Banned in certain countries for use in animals due to concerns about antibiotic resistance (Enrofl oxacin and Ciprofl oxacin).

2: Considered critical (ciprofl oxacin) and highly important (tetracyclines) for humans. 3: Among the highest prescribed in India (ciprofl oxacin).

Why antibiotics are given to chicken?

1: Because this cheap input has a growth promoting effect, making the chicken look fatter.

2: Due to unsanitary conditions in poultry, chickens contract bacterial infections that require treatment antibiotics.

3: Antibiotic for feed is freely available at a low cost in Delhi and outside.

4: Raw chicken has more antibiotic residue than cooked chicken.

5: Regularly exposing yourself to antibiotics through chicken will lead to resistance to some of the important and common antibiotics.

Prevalence of antibiotic resistance? In US:

2 million illnesses and 23,000 deaths annually; estimated $ 20 billion as direct annual healthcare cost. In EU: 25,000 deaths and about Euro 1.5 billion of healthcare cost & productivity losses.

In India (no national level estimate): About one-third of two lakh children that die in the fi rst four weeks are victims of antibiotic resistance; about 15% of those re-treated for TB are resistant to multiple drugs.

What about regulations

India has no regulations or standards for antibiotics given to farm animals.

Some European countries banned use of penicillin, streptomycin and tetracyclines as growth promoters in 1970s. In 1986, Sweden banned antibiotic growth promoters and Denmark followed it.

EU prohibited antibiotic growth promoters in 2006. Between 1995 and 2008, Denmark’s strong policies led to reduction in antibiotic usage by 90% in poultry and 51% in pigs. USA’s voluntary approach a failure. About 80% of antibiotics used in food-producing animals. In 2009-11, use of lincosamides, penicillins and tetracyclines grew by 64%, 44% and 22%, respectively.

CHANDIGARH (TIP): Scientists in Karnal have successfully cloned a male calf from the frozen semen of a Murrah bull which died 10 years ago. “We have for the first time produced a male cloned calf from the somatic cell of progeny-tested bull which died 10 years ago,” director of National Dairy Research Institute (NDRI) Dr AK Srivastava said.

The calf, who has been given name of Rajat, was born on July 23 by using “hand-guided cloning” technique and its weight at the time of the birth was 32 kg, a release from NDRI said. The Murrah bull, whose frozen semen was used to produce male calf, had been ranked first in the 5th set of all-India progeny-testing programme.

A progeny test is performed by mating the male with a number of females to produce many progenies and the average performance of the offspring is then found, giving a measure of the male’s respective value, and it takes years to evaluate its superiority, an NDRI release said. The NDRI Director said there was an acute shortage of good-quality bulls and the technology of “hand-guided cloning” could decrease this gap and supply elite bulls in the shortest possible time.

“We do not have progeny-tested bulls and moreover, there is a shortage of 80-90 million doses of semen in the country.We have frozen semen of progeny-tested bulls and we can produce good quality of bulls by this cloning technique,” Srivastava said. Cloning, which helps in faster multiplication of superior germplasm, can be done through males by producing clones of progeny-tested bulls and through females by producing clone of high-yielding lactating females.

A team of seven scientists — SK Singla, MS Chauhan, RS Manik, P Palta, Shiv Parsad, Anuj Raja and Amol Sahare — was involved in the production of cloned calf. S Ayyappan, secretary, department of agricultural research and education (DARE) and director general, Indian Council of Agricultural Research (ICAR), congratulated the team and said this achievement of producing cloned calf from progeny-tested bull by hand-guided cloning technique will facilitate faster multiplication of elite germplasm and help face the challenges of increasing demands of milk, said the release.

WASHINGTON (TIP): The loss and decline of animals is contributing to what appears to be the early days of the planet’s sixth mass biological extinction event, scientists warn. Since 1500, more than 320 terrestrial vertebrates have become extinct. Populations of the remaining species show a 25 per cent average decline in abundance.

The situation is similarly dire for invertebrate animal life, researchers said. While previous extinctions have been driven by natural planetary transformations or catastrophic asteroid strikes, the current die-off can be associated to human activity, a situation that the lead author Rodolfo Dirzo, a professor of biology at Stanford University, designates an era of “Anthropocene defaunation.”

Across vertebrates, 16 to 33 per cent of all species are estimated to be globally threatened or endangered. Large animals – described as megafauna and including elephants, rhinoceroses, polar bears and countless other species worldwide – face the highest rate of decline, a trend that matches previous extinction events. Larger animals tend to have lower population growth rates and produce fewer offspring.

They need larger habitat areas to maintain viable populations. Although these species represent a relatively low percentage of the animals at risk, their loss would have trickle-down effects that could shake the stability of other species and, in some cases, even human health.