Sci-tech
Tiny
Human Species
The
fossil of a one-metre tall "Hobbit" discovered in
Indonesia may represent a separate species of early humans,
according to a study. The study was carried out by some US,
Australian and Indonesian researchers. The Hobbit was among
the tiny fossils of as many as eight individuals found in
layers dating from 95,000 to 12,000 years ago in a cave on
the Indonesian island of Flores. The Hobbit skeleton was the
most complete specimen and the only one with the skull. Scientists
said the specimen, nicknamed the Hobbit after a character
created by J.R.R. Tolkien, showed clearly that it was a normal
adult of its species. The Hobbit's brain, about 417 cubic
cm in size, had unique features that could allow advanced
behaviour such as hunting, fire-making and the use of stone
tools. However, the theory that the Hobbit may represent a
new human species has met with skepticism. Critics said the
bones could represent a human pygmy or a human afflicted with
microcephaly characterised by a small head circumference.
Hill
Folk Live Longer
People
living in the hills have a longer life span and lower rates
of death due to heart disease than those living in lowland
areas, says a new research. The findings were based on tracking
the cardiovascular health and death rates people living in
hilly areas. They point out that living at moderately high
altitude produces long term physiological changes in the body
to enable it to cope with lower levels of oxygen, and that
this, combined with the exertion required to walk uphill regularly
on rugged terrain, could give the heart a better work-out.
Information on risk factors, including gender, age, weight,
smoking habit, blood pressure, and alcohol consumption, were
collected for each person in 1981. Blood samples were also
taken to build up the profile of biochemical health. After
taking account of all the cardiovascular risk factors, it
was found that mountain village residents had lower death
rates, and lower rates of death from heart disease, than their
peers in the lowlands. The effects were more pronounced among
the men.
Super-Conducting
Electrons
Scientists
in Beijing and Tokyo say they have successfully observed super-conducting
electrons by an ultra-high resolution photoemission spectroscope
that they invented. Chen Chuangtian, academician of the Chinese
Academy of Sciences, Xu Zuyan, academician of the Chinese
Academy of Engineering, and Shuntaro Watanabe and Shik Shi,
professors at the University of Tokyo Institute for Solid
State Physics, led the joint research. "We successfully
observed super-conducting electrons directly by the photoemission
spectroscope with the highest resolution of the world,"
said Chen. "We will be able to solve the exotic super-conducting
mechanism." Three US scientists who depicted the super-conducting
mechanism of metal superconductors won the 1972 Nobel Prize.
But scientists know that compound superconductors have a different
super-conducting mechanism. Chen's team developed the optical
special crystal and the prism-non-linear optical crystal coupling
technique while Watanabe's team developed the laser system
using this crystal. "With the new equipment," he
said, "we observed the super-conducting electrons of
a compound directly for the first time and found that its
super-conducting mechanism has not been known."
Invisibility
Cloak
Researchers,
bringing the magic of Harry Potter into the world of scientific
fact, are developing a cloaking device that makes objects
invisible. Electronic engineers at the University of Pennsylvania
in the US are working on a real invisibility shield called
a 'plasmonic cover', which works by preventing objects from
reflecting and scattering light. The cloak could have widespread
use in the military as it would be more effective than current
stealth technology. Although no final product has been made,
the engineers claim their proposal "does not obviously
violate any of the laws of physics". According to Andrea
Alu and Nader Engheta, the engineers behind the project, objects
are visible because light bounces off them. If this could
be prevented and the objects did not reflect any light, they
would become invisible. The 'plasmonic screen' made of plasmons
- created when the electrons on the surface of a metallic
material move in rhythm - achieves this by resonating in tune
with the illuminating light, they said. The developers claim
a shell of this material will reduce light-scatter to the
extent that an object will become invisible.
Religiousness
Lies in the Genes
A
person's religious nature is more influenced by his genes
than the environment as he grows older, reveals a new study.
According to the study published in the Journal of Personality,
researchers studied adult male monozygotic (MZ) (i.e. Identical
twins) and dizygotic (DZ)(i.e. fraternal twins) and found
that both genes and environment influence difference in religiousness.
But during the transition from adolescence to adulthood, genetic
factors increase in importance while shared environmental
factors decrease. The MZ twins maintained their religious
similarity over time, while the DZ twins became more dissimilar.
"These correlation suggest low genetic and high environmental
influences when the twins were young but a larger genetic
influence as the twins age" the authors state.
Religiousness
was tested using self-report of nine items that measured the
centrality of religion in their lives. External items were
found to be more environmentally and less genetically influenced
during childhood but more genetically influenced in adulthood.
The internal scale showed a similar pattern, but the genetic
influences seemed to be slightly larger in childhood compared
to the external scale and so more consistent across the two
ages. "Like other personality traits, adult religiousness
is heritable and though changes in religiousness occur during
development, it is fairly stable," the authors conclude.
Source:
Discovery News, Nature, Webindia123 and Xinhua.
Compiled
by: Imran H. Khan
Copyright
(R) thedailystar.net 2005
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