Wednesday 2 May 2012

Why bigger animals aren't always faster

Above a certain size, lizards were changing the way they ran, according to a new research. File Photo: K. Gopinathan
The Hindu Above a certain size, lizards were changing the way they ran, according to a new research. File Photo: K. Gopinathan 
 
Researchers have shed light on why bigger is not always better when it comes to running speed.
"Typically, bigger animals tend to run faster than smaller animals, because they have longer legs,” said Christofer J. Clemente of Harvard University, who led the research. "But this only works up to a point. The fastest land animal is neither the biggest nor the smallest, but something in between. Think about the size of an elephant, a mouse and a cheetah.” Clemente and his team studied monitor lizards to show that that the same principle applies within species as well as across species, and to identify why this is the case. Because adult monitor lizards vary substantially in size, they are an ideal species for testing how size affects speed. The researchers timed and photographed monitors ranging from two to 12 pounds, as sprinted across a 45-foot track.
The researchers found that the midsize lizards were fastest-and they discovered why.
Using high-speed cameras and markers placed at key spots on the lizards’ bodies, the researchers created computer models comparing characteristics of the lizards’ running strides.
"We then looked at how the mechanics of the stride changed with body size, and we found that the changes in the stride were consistent with the changes in speed,” Clemente said. "Above a certain size, lizards were changing the way they ran, perhaps due to a decreased ability of the bones and muscles to support a larger body mass.” Testing this phenomenon within a single species helps clear up questions about why the biggest animals aren’t the fastest. Large animals tend to be closely related evolutionarily. So it’s hard to tell whether slower speeds are due to biomechanical issues stemming from size, or from any number of other factors stemming from a shared evolutionary history.
Looking at individuals within a species rather than making cross-species comparisons helps to eliminate this phylogenetic bias. The results bolster the hypothesis that large size creates biomechanical constraints.
"Larger lizards’ legs can no longer support their body weight, and they have to change their style of running, making them slower,” Clemente added.
The study has been published in the journal Physiological and Biochemical Zoology.

The Govt may hike up more D.A. from July,2012 on the basis price index

New Delhi, May  1, 2012:   All India Consumer Price Index Number for Industrial Workers (CPI-IW) on base 2001=100 for the month of March, 2012 increased by 2 points and stood at 201 (two hundred one).
During March, 2012, the index recorded maximum increase of 7 points each in Bhilwara,Vijaywada  and  Salem centres, 6 points each in Belgaum, Ajmer, Ghaziabad and Mundakkayam centres, 5 points in 3centres, 4 points in 6 centres, 3 points in 12 centres, 2 points in 19 centres and 1 point in 19 centres. The index decreased by 2 points in Tripura centre and 1 point each in Darjeeling, Sholapur and Puducherry centres, while in the remaining 8centres the index remained stationary.
The indices in respect of the six major centres are as follows :
1. Ahmedabad  -201,  2. Bangalore-206,  3. Chennai-187,  4. Delhi-185,  5. Kolkata-190 and  6. Mumbai-204
The point to point rate of inflation based on CPI-IW(General) for the month of March, 2012 is 8.65% as compared to 7.57% in February, 2012. Inflation based on Food Index attained the level of 8.16% in March, 2012 as compared to 5.08% in February, 2012.
The CPI-IW for April, 2012 will be released on the last working day of the next month, i.e. 31st May, 2012.

Huge increase in candidates seeking central jobs

Mumbai, May 1, 2012(IANS): There has been a whopping eight-fold increase in the number of applicants for the prestigious Staff Selection Commission examinations, from one million to nearly nine million in the past four years, a top official said here Tuesday.


In 2008-2009, the SSC exams hopefuls were one million, which shot up to 8.85 million in 2011-2012, said SSC chairman N. K. Raghupathy.

“We are expecting 13 million applications during this year – 2012-13. The SSC is being tasked with recruiting large number of personnel for internal security agencies of the Home Ministry,” Raghupathy told media persons here this evening.
In order to handle the huge number of applications and as part of its mission to modernize the recruitment system for government jobs, Raghupathy said that SSC has introduced online application facilities.
“We want to take this process further and study feasibility of introducing online examinations. But, we are hindered by lack of hardware infrastructure,” Raghupathy admitted.
For instance, he explained that making available sufficient number of computer terminals for such a large number of candidates is the biggest challenge in introducing online examinations.
Discussing other developments, he said the SSC has restructured the examination pattern as per the recommendations made by the Second Administrative Reforms Commission.
It has improved the communication with applicants through its 10 regional language websites to attract more candidates.