SNIPPETS-Identifying gender from a fingerprint
Sindya N Bhanoo Dec 1, 2015, The New York Times
A simple test performed at a crime scene may help forensic scientists determine whether a fingerprint belongs to a man or a woman, a new study reports. The test is based on certain amino acids found in the fingerprints. Levels are twice as high in the sweat of women as in that of men.
“Fingerprints have really been treated as pictures for more than a hundred years,” said Jan Halamek, a forensic scientist at the State University of New York at Albany and one of the study’s authors. “The only major improvements in recent years have been due to software and databases that make it faster to match fingerprints.”
Regardless of the surface type, they found it was possible to tell whether the fingerprint belonged to a woman by testing levels of residual amino acids. The report was published in the journal Analytical Chemistry. The study involved only a few fingerprints, however, and a larger sample is required to ensure the results are statistically significant, Jan said.
He and his colleagues are developing additional fingerprint tests based on protein markers found in blood samples. “We want to create a very simple kit which can determine on the spot whether the person was young or old, male or female, and their ethnicity,” Jan said. These tests, he cautioned, could not replace DNA tests, which are reliable but also time-consuming and expensive.
Astrobiological impacts of neutrinos
This year’s Physics Nobel Prize for the discovery of neutrino oscillations implies that at least one of the three neutrino species has a tiny mass, possibly of the order of one or a few electron volts. Individual neutrino masses are yet to be accurately ascertained. But the oscillations measure is the mass difference squared, i.e., for two species 1 and 2 or more, it is precisely the product of the mass difference squared and the mixing angle.
For instance, independent cosmological evidence from the Wilkinson Microwave Anisotropy Probe (WMAP) suggests that the sum total of the masses is about an electron volt. Other experiments suggest a few electron volts. As each neutrino has a corresponding antineutrino, there are totally six types of neutrinos.
Now, neutrinos are expected to have been produced profusely in the very initial stages of the universe, i.e., during the Big Bang. Similar to the microwave background which is the fossil remnant of the high energy radiation, which characterised the hot dense phase of the earlier epoch, we also expect a fossil remnant of neutrinos, which now form a background with an estimated density of about 150 per cubic centimetre, per species. So, in summation, from all the six species we expect a fossil neutrino background with a number density of 1,000 per cubic centimetre.
So, if each neutrino had a mass of about even 20 electron volts, this would imply that the Universe would have a density much greater than the closure density and would have collapsed several billion years ago. But a universe where a neutrino had a 50 electron volt rest mass would definitely not have had much of a chance to develop biological life, let alone support advanced forms of evolved life.
Since at present, we do not have a definitive understanding of neutrino masses, one wonders whether there can be some anthropic requirement for low masses. Neutrinos are known to be produced prodigiously in a Type-2 supernova, where a massive star collapses after its iron core can no longer continue to produce thermonuclear energy.
A supernova occurring 10 light years away would produce 10 billion neutrino captures in a kiloton detector and each of us would capture one lakh high energy neutrinos, which could potentially cause DNA cell damage. The captured neutrinos would produce damaging gamma rays, high energy neutrons, among other elements. So, life on potential planets neighbouring massive star associations, (or stellar systems) like OB associations could be severely constrained.
“Fingerprints have really been treated as pictures for more than a hundred years,” said Jan Halamek, a forensic scientist at the State University of New York at Albany and one of the study’s authors. “The only major improvements in recent years have been due to software and databases that make it faster to match fingerprints.”
Regardless of the surface type, they found it was possible to tell whether the fingerprint belonged to a woman by testing levels of residual amino acids. The report was published in the journal Analytical Chemistry. The study involved only a few fingerprints, however, and a larger sample is required to ensure the results are statistically significant, Jan said.
He and his colleagues are developing additional fingerprint tests based on protein markers found in blood samples. “We want to create a very simple kit which can determine on the spot whether the person was young or old, male or female, and their ethnicity,” Jan said. These tests, he cautioned, could not replace DNA tests, which are reliable but also time-consuming and expensive.
Astrobiological impacts of neutrinos
This year’s Physics Nobel Prize for the discovery of neutrino oscillations implies that at least one of the three neutrino species has a tiny mass, possibly of the order of one or a few electron volts. Individual neutrino masses are yet to be accurately ascertained. But the oscillations measure is the mass difference squared, i.e., for two species 1 and 2 or more, it is precisely the product of the mass difference squared and the mixing angle.
For instance, independent cosmological evidence from the Wilkinson Microwave Anisotropy Probe (WMAP) suggests that the sum total of the masses is about an electron volt. Other experiments suggest a few electron volts. As each neutrino has a corresponding antineutrino, there are totally six types of neutrinos.
Now, neutrinos are expected to have been produced profusely in the very initial stages of the universe, i.e., during the Big Bang. Similar to the microwave background which is the fossil remnant of the high energy radiation, which characterised the hot dense phase of the earlier epoch, we also expect a fossil remnant of neutrinos, which now form a background with an estimated density of about 150 per cubic centimetre, per species. So, in summation, from all the six species we expect a fossil neutrino background with a number density of 1,000 per cubic centimetre.
So, if each neutrino had a mass of about even 20 electron volts, this would imply that the Universe would have a density much greater than the closure density and would have collapsed several billion years ago. But a universe where a neutrino had a 50 electron volt rest mass would definitely not have had much of a chance to develop biological life, let alone support advanced forms of evolved life.
Since at present, we do not have a definitive understanding of neutrino masses, one wonders whether there can be some anthropic requirement for low masses. Neutrinos are known to be produced prodigiously in a Type-2 supernova, where a massive star collapses after its iron core can no longer continue to produce thermonuclear energy.
A supernova occurring 10 light years away would produce 10 billion neutrino captures in a kiloton detector and each of us would capture one lakh high energy neutrinos, which could potentially cause DNA cell damage. The captured neutrinos would produce damaging gamma rays, high energy neutrons, among other elements. So, life on potential planets neighbouring massive star associations, (or stellar systems) like OB associations could be severely constrained.
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