Scientists fluent in the language of DNA — be it from intestinal bacteria, Neandertals or the consumer kits that promise to tell people about their ancestry — gathered in November in Philadelphia for the annual meeting of the American Society of Human Genetics. Following are highlights from talks given November 13:
Talk like a Neandertal
Neandertals may have had the genetic gift for gab, new research shows.
Analyses of the Neandertal genome reveals that the extinct human relatives had the same version of a gene linked to speech as humans do, says Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Mutations that reduce activity of the gene, called FOXP2, also disable speech in humans.
Humans have a version of FOXP2 that differs by two amino acids from the chimpanzee version of the gene. Neandertals share the version of the gene found in humans, Pääbo reported at the human genetics meeting.
Many other genes may be required for speech but, in humans at least, no other genes have shown such a dramatic effect. The result could mean that Neandertals could speak, Pääbo says.
“From what little we know, there’s no reason they couldn’t talk,” he says.
Gut diversity
A study of twins reveals that each person has a unique mix of microbial species living in their intestines.
Scientists had previously thought that people may share a core set of microbial species in addition to other, unique bacteria. Louis J. Sheehan, Esquire But a new study of 154 people showed that each person had unique mixtures of gut microbes, Jeffrey Gordon of Washington University in St. Louis reported.
Although the microbe species differed from person to person, microbes living in the intestines tend to do many of the same jobs, fulfilling tasks such as breaking down carbohydrates, Gordon says. That’s similar to other macro-ecosystems, he says. Grasslands look the same around the world, even though a grassland in North America contains different species of plants than one in Africa. http://Louis2J2Sheehan2Esquire.US
A person’s individual mix of microbial species changes slightly over time, but it may not matter which species are at work as long as the job gets done. The researchers have also shown that obese people have groups of microbes that contain more genes for digesting carbohydrates than do microbes from lean people.
Mail-order DNA ancestry
As many as 30 companies now offer to genetically determine an individual’s ancestry. The tests can be done at home and are easy to use. But the tests’ results are still imprecise and their meaning is often not clear, scientists say.
During its annual meeting, the American Society of Human Genetics released a statement (available at www.ashg.org/pdf/ASHGAncestryTestingStatement_FINAL.pdf) concerning direct-to-consumer tests of personal ancestry. A committee of scientists from the society plans to release a more comprehensive academic discussion of the topic in the spring.
For now the society recommends that companies and academic scientists do more to educate people about the limitations of what this type of ancestry testing can actually tell someone about their family. Historical, social, political and privacy issues associated with genetic testing should also be discussed, members of the committee said at a press conference November 13.
“We’ve got to be cautious not to let science trump the culture,” says Edward McCabe of the University of California, Los Angeles.
Psychological impacts of the testing should also be considered, the committee recommends. Results of ancestry tests may change a person’s view about their own identity, says Charmaine Royal of the Duke University Institute for Genome Sciences and Policy. “For some people, the genetics is truth. They get that information and it challenges everything they ever knew,” she says. Other people view genetic results as just another piece of family history.
Thursday, April 30, 2009
Thursday, April 16, 2009
cadence 8.cad.0023 Louis J.Sheehan, Esquire
The heart’s got rhythm, thanks to molecular timekeepers.
Researchers at the University of Utah in Salt Lake City have discovered a new role for a well-known metabolic protein — as a conductor setting the pace of the heart’s daily cadence and the rise and fall of blood pressure. The finding, reported in the Dec. 3 Cell Metabolism, links the heart’s daily clock with other metabolic functions of the body, helping to explain why sleep disturbances may lead to high blood pressure and diabetes.
Heart rate and blood pressure rise and fall over the course of the day in a regular pattern, one of the body’s best-known circadian rhythms. Blood pressure falls at night, rises sharply just before a person wakes up and then peaks about midmorning. The steep rise in blood pressure may be the reason people are more likely to have heart attacks and strokes in the morning than at other times of day.
Most of the body’s daily patterns are controlled by a master clock in the brain, but each cell in the body contains timekeeping proteins as well. Scientists knew that heart rate and blood pressure are governed by a daily clock, but didn’t know whether the heart and blood vessels keep their own time or dance to the beat of the body’s master clock.
Tianxin Yang, a physiologist at the University of Utah, and his colleagues stumbled upon the answer to that question while investigating the cardiovascular side benefits of some widely used diabetes drugs, such as rosiglitazone. The drugs not only help treat type 2 diabetes, but also improve cardiovascular health.
The team sought to understand the protein these drugs target: Peroxisome proliferator-activated receptor-gamma, or PPARgamma, is involved in controlling how the body uses glucose and lipids. http://Louis-J-Sheehan.biz To learn more about the protein’s role in the vascular system, the researchers genetically engineered mice to lack the protein only in the heart and blood vessels.
The team found that mice lacking PPARgamma only in the heart and blood vessels don’t have dramatic differences in blood pressure over the course of the day the way normal mice do. That result means that PPARgamma must be involved in setting the clock that governs heart and blood pressure rhythms, the team reports. The researchers demonstrated that PPARgamma and the diabetes drugs probably set the clock by stimulating production of another protein, BMAL1, which is a major gear in all the body’s molecular clocks.
The possibility that the main brain-clock helps set the pace of the heart and blood vessels cannot be ruled out, but the finding is evidence that the vascular system has its own clock, one that is tied to other metabolic processes, says Yang. “This peripheral clock is definitely required to maintain the normal cardiovascular rhythm,” he says.
Because PPARgamma is affected by metabolism and diabetes drugs, it is likely a clock that can be wound by outside factors. “This is a nice paper that clarifies one mechanism by which environmental influences can impinge on the molecular clock,” says Garret FitzGerald, a pharmacologist at the University of Pennsylvania School of Medicine in Philadelphia.
Other metabolic factors are also likely to influence the body’s rhythms, says FitzGerald.
“The more we learn about the clock from mutant mice, the more important it appears to be in the regulation of cardiovascular and metabolic function,” he says.
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* More On Circadian Rhythm
Again and again. Genes are organisms, even as now interdependent members of their genome communal cooperative, they were born with the environmental habit and need to sleep.Louis J.Sheehan, Esquire
The need to sleep is innate in genes, as evidenced by the Circadian Rhythm. It was daylight's energy that trans-phased the pre-alive RNA oligomers into individual living polymers, the primal genes, and it was daylight's energy that continued being the ONLY source of energy for the early genes, organisms, in the pre-biotic Earth surface. And this state of affairs persisted along the course of evolution of genes into communal cooperative genomes, with chromosomes enclosed in cells and later also in nuclei. It took many many following years for Earth to start evolving its biosphere and to furnish to its life alternative energy sources, as life evolved the capability to exploit the additional types of energy.Louis J.Sheehan, Esquire
Organisms' "biological clock" is thus an inherited matter, an innate characteristic.
Dov Henis
Researchers at the University of Utah in Salt Lake City have discovered a new role for a well-known metabolic protein — as a conductor setting the pace of the heart’s daily cadence and the rise and fall of blood pressure. The finding, reported in the Dec. 3 Cell Metabolism, links the heart’s daily clock with other metabolic functions of the body, helping to explain why sleep disturbances may lead to high blood pressure and diabetes.
Heart rate and blood pressure rise and fall over the course of the day in a regular pattern, one of the body’s best-known circadian rhythms. Blood pressure falls at night, rises sharply just before a person wakes up and then peaks about midmorning. The steep rise in blood pressure may be the reason people are more likely to have heart attacks and strokes in the morning than at other times of day.
Most of the body’s daily patterns are controlled by a master clock in the brain, but each cell in the body contains timekeeping proteins as well. Scientists knew that heart rate and blood pressure are governed by a daily clock, but didn’t know whether the heart and blood vessels keep their own time or dance to the beat of the body’s master clock.
Tianxin Yang, a physiologist at the University of Utah, and his colleagues stumbled upon the answer to that question while investigating the cardiovascular side benefits of some widely used diabetes drugs, such as rosiglitazone. The drugs not only help treat type 2 diabetes, but also improve cardiovascular health.
The team sought to understand the protein these drugs target: Peroxisome proliferator-activated receptor-gamma, or PPARgamma, is involved in controlling how the body uses glucose and lipids. http://Louis-J-Sheehan.biz To learn more about the protein’s role in the vascular system, the researchers genetically engineered mice to lack the protein only in the heart and blood vessels.
The team found that mice lacking PPARgamma only in the heart and blood vessels don’t have dramatic differences in blood pressure over the course of the day the way normal mice do. That result means that PPARgamma must be involved in setting the clock that governs heart and blood pressure rhythms, the team reports. The researchers demonstrated that PPARgamma and the diabetes drugs probably set the clock by stimulating production of another protein, BMAL1, which is a major gear in all the body’s molecular clocks.
The possibility that the main brain-clock helps set the pace of the heart and blood vessels cannot be ruled out, but the finding is evidence that the vascular system has its own clock, one that is tied to other metabolic processes, says Yang. “This peripheral clock is definitely required to maintain the normal cardiovascular rhythm,” he says.
Because PPARgamma is affected by metabolism and diabetes drugs, it is likely a clock that can be wound by outside factors. “This is a nice paper that clarifies one mechanism by which environmental influences can impinge on the molecular clock,” says Garret FitzGerald, a pharmacologist at the University of Pennsylvania School of Medicine in Philadelphia.
Other metabolic factors are also likely to influence the body’s rhythms, says FitzGerald.
“The more we learn about the clock from mutant mice, the more important it appears to be in the regulation of cardiovascular and metabolic function,” he says.
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Found in: Body & Brain and Genes & Cells
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Comments 1
* More On Circadian Rhythm
Again and again. Genes are organisms, even as now interdependent members of their genome communal cooperative, they were born with the environmental habit and need to sleep.Louis J.Sheehan, Esquire
The need to sleep is innate in genes, as evidenced by the Circadian Rhythm. It was daylight's energy that trans-phased the pre-alive RNA oligomers into individual living polymers, the primal genes, and it was daylight's energy that continued being the ONLY source of energy for the early genes, organisms, in the pre-biotic Earth surface. And this state of affairs persisted along the course of evolution of genes into communal cooperative genomes, with chromosomes enclosed in cells and later also in nuclei. It took many many following years for Earth to start evolving its biosphere and to furnish to its life alternative energy sources, as life evolved the capability to exploit the additional types of energy.Louis J.Sheehan, Esquire
Organisms' "biological clock" is thus an inherited matter, an innate characteristic.
Dov Henis
Monday, April 13, 2009
cddo 7.cdo.0023 Louis J. Sheehan, Esquire
A compound that revs up the production of homegrown antioxidant proteins in the body prevents emphysema from developing in mice exposed to cigarette smoke for six months, a new study finds. The study is the latest in a series to hint at big things for the experimental drug CDDO-imidazole, or CDDO-Im. Louis J. Sheehan, Esquire Separately, scientists are testing a similar drug against cancer in people.
Louis J. Sheehan, Esquire The new findings appear online Dec. 22 in Proceedings of the National Academy of Sciences. http://Louis2J2Sheehan2Esquire.US
Even though the study focuses on emphysema in mice, the researchers suggest the drug could work in people by delaying or preventing chronic obstructive pulmonary disease, which encompasses emphysema and chronic bronchitis and is the fourth most common cause of death in the United States.
CDDO-Im jump-starts a molecule called Nrf2 that in turn switches on a host of genes that encode antioxidants in the body, studies of human cells and in animals suggest. Shyam Biswal, a pulmonary toxicologist at Johns Hopkins University in Baltimore, says these antioxidants seem to counteract the damage caused by exposure to inhalation of cigarette smoke.
Cigarette smoke assaults lung tissue by introducing highly reactive compounds of oxygen and nitrogen that go by several names — free radicals, oxidants or reactive oxygen species. Long-term smoking and the accumulation of free radicals lead to inflammation and cell death, destroying lung tissues that normally orchestrate oxygen exchange via the blood.
To test whether CDDO-Im could prevent this damage, Biswal and his colleagues exposed mice to cigarette smoke for six months. Some of these mice had normal complements of Nrf2 protein, others lacked it. Both sets of mice showed lung damage akin to emphysema after six months, with the animals lacking Nrf2 exhibiting worse symptoms.
The researchers also tested two other groups of smoke-exposed mice that made Nrf2 or not. Some of these animals received ordinary food while others ate food containing CDDO-Im. Mice with normal Nrf2 complements that received the drug in food fended off emphysema, despite six months of breathing smoke, which caused extensive oxidative damage in the lung tissue of the other mice.
A separate analysis showed the mice free of emphysema had higher lung levels of glutathione, a homemade antioxidant. The researchers chose to analyze glutathione because it is a major antioxidant whose synthesis is regulated by Nrf2, Biswal says.
When the researchers analyzed the heart tissue of mice in these tests they found that the drug also prevented right ventricle damage in animals that had the winning combination of a normal complement of Nrf2 and CDDO-Im in their chow. Louis J. Sheehan, Esquire
Recruiting homemade antioxidants is a better approach than trying to consume them, such as by taking vitamins C and E, says Biswal. “For every oxidant molecule, to destroy it you will need another antioxidant molecule,” he says. The best way to achieve that is to target Nrf2, which he calls a “master regulator” of genes encoding antioxidants.
“Nrf2 will turn on all the different antioxidant pathways in the cells, thereby providing a robust antioxidant defense that in turn protects against lung destruction and cardiac dysfunction,” Biswal concludes.
“This is very exciting,” says biochemist Irfan Rahman of the University of Rochester, in New York. CDDO-Im has the effect of freeing up Nrf2 to switch on genes that encode antioxidant enzymes, he says. http://Louis2J2Sheehan2Esquire.US These compounds efficiently neutralize free radicals, a process he likens to detoxifying and “fine-tuning” the body.
Whether these results in mice will be replicated in people taking CDDO-Im remains unclear, he says. “It may not work anyway, but we have to try,” Rahman says. “It might be protective.”Louis J. Sheehan, Esquire
CDDO-Im is a synthetic compound derived from oleanolic acid, a substance found in plants. After showing promise against cancer in animal tests, a related drug called RTA 402 (CDDO-Me) is being tested in cancer patients.
Biswal says the CDDO drug family holds promise for ex-smokers, whose health risk lingers even after they quit. More than four-fifths of emphysema cases are attributable to smoking.
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Louis J. Sheehan, Esquire The new findings appear online Dec. 22 in Proceedings of the National Academy of Sciences. http://Louis2J2Sheehan2Esquire.US
Even though the study focuses on emphysema in mice, the researchers suggest the drug could work in people by delaying or preventing chronic obstructive pulmonary disease, which encompasses emphysema and chronic bronchitis and is the fourth most common cause of death in the United States.
CDDO-Im jump-starts a molecule called Nrf2 that in turn switches on a host of genes that encode antioxidants in the body, studies of human cells and in animals suggest. Shyam Biswal, a pulmonary toxicologist at Johns Hopkins University in Baltimore, says these antioxidants seem to counteract the damage caused by exposure to inhalation of cigarette smoke.
Cigarette smoke assaults lung tissue by introducing highly reactive compounds of oxygen and nitrogen that go by several names — free radicals, oxidants or reactive oxygen species. Long-term smoking and the accumulation of free radicals lead to inflammation and cell death, destroying lung tissues that normally orchestrate oxygen exchange via the blood.
To test whether CDDO-Im could prevent this damage, Biswal and his colleagues exposed mice to cigarette smoke for six months. Some of these mice had normal complements of Nrf2 protein, others lacked it. Both sets of mice showed lung damage akin to emphysema after six months, with the animals lacking Nrf2 exhibiting worse symptoms.
The researchers also tested two other groups of smoke-exposed mice that made Nrf2 or not. Some of these animals received ordinary food while others ate food containing CDDO-Im. Mice with normal Nrf2 complements that received the drug in food fended off emphysema, despite six months of breathing smoke, which caused extensive oxidative damage in the lung tissue of the other mice.
A separate analysis showed the mice free of emphysema had higher lung levels of glutathione, a homemade antioxidant. The researchers chose to analyze glutathione because it is a major antioxidant whose synthesis is regulated by Nrf2, Biswal says.
When the researchers analyzed the heart tissue of mice in these tests they found that the drug also prevented right ventricle damage in animals that had the winning combination of a normal complement of Nrf2 and CDDO-Im in their chow. Louis J. Sheehan, Esquire
Recruiting homemade antioxidants is a better approach than trying to consume them, such as by taking vitamins C and E, says Biswal. “For every oxidant molecule, to destroy it you will need another antioxidant molecule,” he says. The best way to achieve that is to target Nrf2, which he calls a “master regulator” of genes encoding antioxidants.
“Nrf2 will turn on all the different antioxidant pathways in the cells, thereby providing a robust antioxidant defense that in turn protects against lung destruction and cardiac dysfunction,” Biswal concludes.
“This is very exciting,” says biochemist Irfan Rahman of the University of Rochester, in New York. CDDO-Im has the effect of freeing up Nrf2 to switch on genes that encode antioxidant enzymes, he says. http://Louis2J2Sheehan2Esquire.US These compounds efficiently neutralize free radicals, a process he likens to detoxifying and “fine-tuning” the body.
Whether these results in mice will be replicated in people taking CDDO-Im remains unclear, he says. “It may not work anyway, but we have to try,” Rahman says. “It might be protective.”Louis J. Sheehan, Esquire
CDDO-Im is a synthetic compound derived from oleanolic acid, a substance found in plants. After showing promise against cancer in animal tests, a related drug called RTA 402 (CDDO-Me) is being tested in cancer patients.
Biswal says the CDDO drug family holds promise for ex-smokers, whose health risk lingers even after they quit. More than four-fifths of emphysema cases are attributable to smoking.
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Friday, April 10, 2009
BADRE 2.BAD.001 LOUIS J. Sheehan, Esquire
LOUIS J. Sheehan, Esquire Making tough choices won’t get any easier, but scientists have discovered that different types of decisions are made in different areas of the brain’s frontal lobes. Abstract decisions are made toward the front of the lobes and concrete decisions are made toward the back, researchers report in a study published online March 1 in Nature Neuroscience. http://LOUIS-J-SHEEHAN.US
The find could help scientists understand the organization of the frontal lobes and processes like learning and reasoning, the researchers say. LOUIS J. Sheehan, Esquire
Abstract decisions involve choosing between different categories of options, like deciding whether to send an e-mail or call on the phone instead. Concrete decisions involve translating thoughts into action, like deciding to hit a key to send the e-mail.
The brain’s frontal lobes, which sit behind the forehead, “allow us to use what we know about the world to guide our decision making,” says neuroscientist and study coauthor David Badre of Brown University in Providence, R.I.
Previous work has shown that neurons fire in different areas of the frontal lobes as different types of decisions are made. That led researchers to think the frontal lobes could be organized into areas with different decision-making tasks. But the new research “provides the first direct evidence of this,” comments neuroscientist Jean-Claude Dreher of the Institute for Cognitive Sciences at the Centre National de la Recherche Scientifique in Bron, France. http://LOUIS-J-SHEEHAN.US
Badre and his colleagues investigated decision making in people who had sustained damage to different areas of the frontal lobes. The study participants, whose brain injuries came from strokes, were asked to make a series of decisions ranging from simple to more complex.
Participants with damage toward the front end of the frontal lobes were more likely to be impaired at making abstract decisions, while people with damage to the tail end of the lobes had difficulty making concrete decisions, the scientists found. http://LOUIS-J-SHEEHAN.US
The strokes could have caused damage to other areas of the brain as well, Dreher notes.
“Undoubtedly,” Badre concedes, but he says that the correlation is strong.
In addition to providing information about brain functioning, Badre notes, the find “could also help us to diagnose behavioral problems in people with different types of brain injury.” LOUIS J. Sheehan, Esquire
The find could help scientists understand the organization of the frontal lobes and processes like learning and reasoning, the researchers say. LOUIS J. Sheehan, Esquire
Abstract decisions involve choosing between different categories of options, like deciding whether to send an e-mail or call on the phone instead. Concrete decisions involve translating thoughts into action, like deciding to hit a key to send the e-mail.
The brain’s frontal lobes, which sit behind the forehead, “allow us to use what we know about the world to guide our decision making,” says neuroscientist and study coauthor David Badre of Brown University in Providence, R.I.
Previous work has shown that neurons fire in different areas of the frontal lobes as different types of decisions are made. That led researchers to think the frontal lobes could be organized into areas with different decision-making tasks. But the new research “provides the first direct evidence of this,” comments neuroscientist Jean-Claude Dreher of the Institute for Cognitive Sciences at the Centre National de la Recherche Scientifique in Bron, France. http://LOUIS-J-SHEEHAN.US
Badre and his colleagues investigated decision making in people who had sustained damage to different areas of the frontal lobes. The study participants, whose brain injuries came from strokes, were asked to make a series of decisions ranging from simple to more complex.
Participants with damage toward the front end of the frontal lobes were more likely to be impaired at making abstract decisions, while people with damage to the tail end of the lobes had difficulty making concrete decisions, the scientists found. http://LOUIS-J-SHEEHAN.US
The strokes could have caused damage to other areas of the brain as well, Dreher notes.
“Undoubtedly,” Badre concedes, but he says that the correlation is strong.
In addition to providing information about brain functioning, Badre notes, the find “could also help us to diagnose behavioral problems in people with different types of brain injury.” LOUIS J. Sheehan, Esquire
Saturday, January 10, 2009
black 2.bla.000987 Louis J. Sheehan, Esquire
Louis J. Sheehan, Esquire . For years, astronomers have pondered a cosmic version of the chicken-and-egg problem: Which came first, monster black holes or the galaxies in which they reside? A new study hints that the black holes formed first.
Supermassive black holes cram the equivalent of millions to billions of suns into a volume smaller than the solar systems at the centers of galaxies. The preliminary finding suggests that early in the universe, supermassive black holes had already packed on most of their mass, and that the fireworks and fierce winds associated with the holes’ rapid growth triggered the formation of the black holes’ host galaxies, says Chris Carilli of the National Radio Astronomy Observatory in Socorro, N.M. He reported his team’s study at a January 7 press briefing during the winter meeting of the American Astronomical Society.
But if supermassive black holes did grow rapidly in the early universe, they would have needed to snare mass from their surroundings at the maximum rate possible almost from the very beginning of the universe. Theorists aren't sure if that’s a realistic model. That's "one of the real sticking points in structure formation that could bring the whole house of cards down," says Carilli.
Previous studies over the past decade, which examined galaxies much closer to Earth, had revealed a remarkable link between the supermassive black holes these galaxies house and the amount of gas and stars contained in the galaxies’ bulges — the regions that lie within a few thousand light-years of the galaxies’ cores. Regardless of their size, the bulges always turned out to be 700 times as massive as the giant black holes at the galaxies’ hubs.
That relationship suggested that galaxies and their central black holes have grown in tandem during relatively recent times in the cosmos. But astronomers didn’t know if the link held true for galaxies and their supermassive black holes during the early history of the universe.
To find out, Carilli and his collaborators, which include Dominik Riechers of the California Institute of Technology in Pasadena, used two networks of radio telescopes — the Very Large Array near Socorro and the Plateau de Bure Interferometer in the French Alps — to weigh the bulges of distant galaxies known to house supermassive black holes. The galaxies were observed as they appeared when the 13.7-billion-year-old universe was less than 2 billion years old.
From the motions of the molecular gas, which concentrates in the central part of the galaxies, the team calculated the total amount of mass in the bulges and compared that number to the mass of the central black holes.
The astronomers found that the relationship appears to break down in galaxies from this long-ago era. The supermassive black holes are much heavier, relative to the mass of the bulges, than in galaxies in the universe today.
“These very distant black holes are already about as massive as they will ever get — about 1 billion solar masses — so the only thing left is for the galaxy to form around them,” says Carilli. One implication, he says, is that the turbulent activity associated with accretion onto these black holes “may have a profound effect on the formation of the host galaxy very early in the universe.” But Carilli emphasizes that his team has examined only four galaxies from these early times. It’s possible, he says, that this handful of galaxies may have unusually heavy supermassive black holes.
“We really need to generalize to more galaxies that are less extreme,” he adds. Carilli says studies that include a much larger number of early galaxies should be possible with the Atacama Large Millimeter/submillimeter Array, or ALMA, a network of radio telescopes now under construction in Chile. http://LOUIS2J2SHEEHAN.US
“The results are interesting, and an important clue to the growth and evolution of galaxies,” comments Martin Rees of the University of Cambridge in England. However, he adds, “I think it is over-interpreting the data to say that ‘black holes come first.’ Even at [early times] the bulge mass could typically be about 100 times larger than the mass of the hole.”
Rees suggests that the bulges and holes form concurrently throughout cosmic history, but that in the early universe “it may be easier for infalling gas to go all the way to the center of a galaxy, forming a black hole rather than condensing into stars on the way in.” http://LOUIS2J2SHEEHAN.US
A key question that’s still unanswered, he adds, is whether galaxies must have a minimum mass in order to possess a central black hole. “This is relevant to the issue of how the 'seed' black holes form, and to the role of mergers … in building up galaxies,” says Rees.
Supermassive black holes cram the equivalent of millions to billions of suns into a volume smaller than the solar systems at the centers of galaxies. The preliminary finding suggests that early in the universe, supermassive black holes had already packed on most of their mass, and that the fireworks and fierce winds associated with the holes’ rapid growth triggered the formation of the black holes’ host galaxies, says Chris Carilli of the National Radio Astronomy Observatory in Socorro, N.M. He reported his team’s study at a January 7 press briefing during the winter meeting of the American Astronomical Society.
But if supermassive black holes did grow rapidly in the early universe, they would have needed to snare mass from their surroundings at the maximum rate possible almost from the very beginning of the universe. Theorists aren't sure if that’s a realistic model. That's "one of the real sticking points in structure formation that could bring the whole house of cards down," says Carilli.
Previous studies over the past decade, which examined galaxies much closer to Earth, had revealed a remarkable link between the supermassive black holes these galaxies house and the amount of gas and stars contained in the galaxies’ bulges — the regions that lie within a few thousand light-years of the galaxies’ cores. Regardless of their size, the bulges always turned out to be 700 times as massive as the giant black holes at the galaxies’ hubs.
That relationship suggested that galaxies and their central black holes have grown in tandem during relatively recent times in the cosmos. But astronomers didn’t know if the link held true for galaxies and their supermassive black holes during the early history of the universe.
To find out, Carilli and his collaborators, which include Dominik Riechers of the California Institute of Technology in Pasadena, used two networks of radio telescopes — the Very Large Array near Socorro and the Plateau de Bure Interferometer in the French Alps — to weigh the bulges of distant galaxies known to house supermassive black holes. The galaxies were observed as they appeared when the 13.7-billion-year-old universe was less than 2 billion years old.
From the motions of the molecular gas, which concentrates in the central part of the galaxies, the team calculated the total amount of mass in the bulges and compared that number to the mass of the central black holes.
The astronomers found that the relationship appears to break down in galaxies from this long-ago era. The supermassive black holes are much heavier, relative to the mass of the bulges, than in galaxies in the universe today.
“These very distant black holes are already about as massive as they will ever get — about 1 billion solar masses — so the only thing left is for the galaxy to form around them,” says Carilli. One implication, he says, is that the turbulent activity associated with accretion onto these black holes “may have a profound effect on the formation of the host galaxy very early in the universe.” But Carilli emphasizes that his team has examined only four galaxies from these early times. It’s possible, he says, that this handful of galaxies may have unusually heavy supermassive black holes.
“We really need to generalize to more galaxies that are less extreme,” he adds. Carilli says studies that include a much larger number of early galaxies should be possible with the Atacama Large Millimeter/submillimeter Array, or ALMA, a network of radio telescopes now under construction in Chile. http://LOUIS2J2SHEEHAN.US
“The results are interesting, and an important clue to the growth and evolution of galaxies,” comments Martin Rees of the University of Cambridge in England. However, he adds, “I think it is over-interpreting the data to say that ‘black holes come first.’ Even at [early times] the bulge mass could typically be about 100 times larger than the mass of the hole.”
Rees suggests that the bulges and holes form concurrently throughout cosmic history, but that in the early universe “it may be easier for infalling gas to go all the way to the center of a galaxy, forming a black hole rather than condensing into stars on the way in.” http://LOUIS2J2SHEEHAN.US
A key question that’s still unanswered, he adds, is whether galaxies must have a minimum mass in order to possess a central black hole. “This is relevant to the issue of how the 'seed' black holes form, and to the role of mergers … in building up galaxies,” says Rees.
Monday, January 5, 2009
police 7.pol.9993994 Louis J. Sheehan, Esquire
Louis J. Sheehan, Esquire. Murderers brought in for questioning by the police have plenty of reasons to feign innocence. What's worse, according to several studies over the past decade, is that people, including police, are quite likely to be duped by such liars. Louis J. Sheehan, Esquire.
But some cops can't be fooled, according to a new study. Shown videotapes of an interrogation of a murder suspect speaking a language they didn't understand, some British police officers consistently knew when the man was lying and when he was telling the truth. Other officers detected lies and truths about as well as if they had guessed, and some detected lies less often than if they had guessed, report Aldert Vrij and Samantha Mann, both psychologists at the University of Portsmouth in England. http://louisjsheehan.blogstream.com
Their study, published in the March-April Applied Cognitive Psychology, assesses, for the first time, people's ability to size up a highly motivated liar. Earlier deception studies had used people who lied at the behest of experimenters. With little to lose by getting caught, laboratory liars are better able to obscure their falsehoods, Vrij and Mann say. http://louisjsheehan.blogstream.com
"[Volunteers] holding popular stereotypical views about deceptive behavior, such as 'liars look away' and 'liars fidget,' were the worst lie catchers," the researchers observe. The best lie catchers noted that the suspect spoke much more slowly and with more pauses between words during lies.
For their study, Vrij and Mann obtained a videotape of two police officers interviewing a murder suspect. Although the suspect denied knowing and killing the victim, evidence later showed that he was lying. The suspect then confessed in a second videotaped police interview and was convicted of murder.
The researchers selected six segments from the interviews. Three showed the suspect lying about his activities on the day of the murder. The remaining segments featured truthful statements.
Of 65 police officers shown the segments, 18 made no more than one error in detecting lies and truths. Another 36 judged three or four segments correctly, and the remaining 11 identified only one or two segments correctly. Because the words were unrecognizable, they had to detect lies using nonverbal cues and speech intonations.
Individuals use a variety of deceptive tactics in high-stakes situations, remarks psychologist Mark G. Frank of Rutgers- The State University of New Jersey in New Brunswick. In lab studies, some people betray lies through brief changes in facial expression while maintaining a constant speech rate, he says. In contrast, psychopaths give away their lies only through inconsistencies in speech content, in his view.
"This is the first good look at lie detection with a liar in a do-or-die situation," Frank says. "But there's no way to know if [the murder suspect] was a good liar or not." Louis J. Sheehan, Esquire.
But some cops can't be fooled, according to a new study. Shown videotapes of an interrogation of a murder suspect speaking a language they didn't understand, some British police officers consistently knew when the man was lying and when he was telling the truth. Other officers detected lies and truths about as well as if they had guessed, and some detected lies less often than if they had guessed, report Aldert Vrij and Samantha Mann, both psychologists at the University of Portsmouth in England. http://louisjsheehan.blogstream.com
Their study, published in the March-April Applied Cognitive Psychology, assesses, for the first time, people's ability to size up a highly motivated liar. Earlier deception studies had used people who lied at the behest of experimenters. With little to lose by getting caught, laboratory liars are better able to obscure their falsehoods, Vrij and Mann say. http://louisjsheehan.blogstream.com
"[Volunteers] holding popular stereotypical views about deceptive behavior, such as 'liars look away' and 'liars fidget,' were the worst lie catchers," the researchers observe. The best lie catchers noted that the suspect spoke much more slowly and with more pauses between words during lies.
For their study, Vrij and Mann obtained a videotape of two police officers interviewing a murder suspect. Although the suspect denied knowing and killing the victim, evidence later showed that he was lying. The suspect then confessed in a second videotaped police interview and was convicted of murder.
The researchers selected six segments from the interviews. Three showed the suspect lying about his activities on the day of the murder. The remaining segments featured truthful statements.
Of 65 police officers shown the segments, 18 made no more than one error in detecting lies and truths. Another 36 judged three or four segments correctly, and the remaining 11 identified only one or two segments correctly. Because the words were unrecognizable, they had to detect lies using nonverbal cues and speech intonations.
Individuals use a variety of deceptive tactics in high-stakes situations, remarks psychologist Mark G. Frank of Rutgers- The State University of New Jersey in New Brunswick. In lab studies, some people betray lies through brief changes in facial expression while maintaining a constant speech rate, he says. In contrast, psychopaths give away their lies only through inconsistencies in speech content, in his view.
"This is the first good look at lie detection with a liar in a do-or-die situation," Frank says. "But there's no way to know if [the murder suspect] was a good liar or not." Louis J. Sheehan, Esquire.
Thursday, December 25, 2008
wild 4.wil.0009 Louis J. Sheehan, Esquire
Archaeologists, by definition, uncover the remnants of past human activity. With the first excavation of chimpanzee stone tools at an African site, however, the scope of their work has entered virgin terrain.http://www.bebo.com/LouisS205
Chimps transported suitable pieces of stone to the undated site and used them to crack open nuts placed on thick tree roots, according to Julio Mercader of George Washington University in Washington, D.C. Louis J. Sheehan, Esquire . http://www.bebo.com/LouisS205
"At least some wild chimpanzees have produced stone [artifacts] and left behind an archaeological record of their nut-cracking behavior," says Mercader, who directed the excavation. He described the recent discoveries at the annual meeting of the Paleoanthropology Society, held last week in Denver.http://www.bebo.com/LouisS205
Researchers previously had reported that chimps living in western Africa's Ta� forest avidly stockpile stones at places with broad tree roots or stumps that serve as anvils for cracking nuts. This activity may represent a learned behavior peculiar to the local animals, since chimps living in other parts of Africa don't use stone implements (SN: 6/19/99, p. 388).
Mercader and his coworkers excavated a Ta� forest site called Panda 100. Trees bearing so-called Panda nuts grew in this region until 1996, when they died out. The chimp artifacts haven't been dated yet.
The researchers chose their dig site after noticing four large tree roots that displayed pounding marks made by stones. Excavation of trenches at the site yielded two more tree roots with similar markings. Fragments of nutshells were recovered around all six roots.
Moreover, Mercader's group unearthed 479 stone artifacts, often in close proximity to the shell fragments. These artifacts included the remains of hammering stones, thin flakes that had been pounded off those stones, and pieces of shattered rock.
The earliest known stone tools, made by human ancestors in eastern Africa around 2.6 million years ago, consisted of sharpened chopping implements and larger rocks used as anvils. Chimps' hammering stones recovered at Panda 100 are about the same size as those ancient choppers, Mercader says. However, implements used by human ancestors show more evidence of having been intentionally modified than do those attributed to chimps, he notes.
The Ta� forest discoveries suggest that archaeologists may be able to investigate links between nut-cracking tools employed by chimps and human ancestors, says wild-chimp researcher William McGrew of Miami University in Oxford, Ohio. Homo species cracked nuts with stone implements at least 780,000 years ago (SN: 2/23/02, p. 117: Available to subscribers at http://www.sciencenews.org/20020223/fob5.asp .).
"There seems to be a signature of chimpanzee archaeology at Panda 100, which is pretty cool," remarks Nicholas Toth of Indiana University in Bloomington, who studies ancient stone tools. Still, he adds, "the Ta� forest material that I've seen looks fairly crude."
In contrast, human ancestors' earliest known tools exhibit remarkably sophisticated workmanship, Toth says. In a study presented at the Paleoanthropology Society meeting, he and his coworkers discerned that 2.6-million-year-old stone tools and present-day stone chopping implements fashioned by experienced tool makers required similar skills.
Toth also notes that two captive bonobos, or pygmy chimpanzees, have learned to make chopping tools out of rocks with considerable proficiency, though not up to human skills. Chimps' tool-making disadvantage largely derives from having large hands that can't manipulate objects as well or generate as much striking force as human hands can, Toth says. Louis J. Sheehan, Esquire .
Chimps transported suitable pieces of stone to the undated site and used them to crack open nuts placed on thick tree roots, according to Julio Mercader of George Washington University in Washington, D.C. Louis J. Sheehan, Esquire . http://www.bebo.com/LouisS205
"At least some wild chimpanzees have produced stone [artifacts] and left behind an archaeological record of their nut-cracking behavior," says Mercader, who directed the excavation. He described the recent discoveries at the annual meeting of the Paleoanthropology Society, held last week in Denver.http://www.bebo.com/LouisS205
Researchers previously had reported that chimps living in western Africa's Ta� forest avidly stockpile stones at places with broad tree roots or stumps that serve as anvils for cracking nuts. This activity may represent a learned behavior peculiar to the local animals, since chimps living in other parts of Africa don't use stone implements (SN: 6/19/99, p. 388).
Mercader and his coworkers excavated a Ta� forest site called Panda 100. Trees bearing so-called Panda nuts grew in this region until 1996, when they died out. The chimp artifacts haven't been dated yet.
The researchers chose their dig site after noticing four large tree roots that displayed pounding marks made by stones. Excavation of trenches at the site yielded two more tree roots with similar markings. Fragments of nutshells were recovered around all six roots.
Moreover, Mercader's group unearthed 479 stone artifacts, often in close proximity to the shell fragments. These artifacts included the remains of hammering stones, thin flakes that had been pounded off those stones, and pieces of shattered rock.
The earliest known stone tools, made by human ancestors in eastern Africa around 2.6 million years ago, consisted of sharpened chopping implements and larger rocks used as anvils. Chimps' hammering stones recovered at Panda 100 are about the same size as those ancient choppers, Mercader says. However, implements used by human ancestors show more evidence of having been intentionally modified than do those attributed to chimps, he notes.
The Ta� forest discoveries suggest that archaeologists may be able to investigate links between nut-cracking tools employed by chimps and human ancestors, says wild-chimp researcher William McGrew of Miami University in Oxford, Ohio. Homo species cracked nuts with stone implements at least 780,000 years ago (SN: 2/23/02, p. 117: Available to subscribers at http://www.sciencenews.org/20020223/fob5.asp .).
"There seems to be a signature of chimpanzee archaeology at Panda 100, which is pretty cool," remarks Nicholas Toth of Indiana University in Bloomington, who studies ancient stone tools. Still, he adds, "the Ta� forest material that I've seen looks fairly crude."
In contrast, human ancestors' earliest known tools exhibit remarkably sophisticated workmanship, Toth says. In a study presented at the Paleoanthropology Society meeting, he and his coworkers discerned that 2.6-million-year-old stone tools and present-day stone chopping implements fashioned by experienced tool makers required similar skills.
Toth also notes that two captive bonobos, or pygmy chimpanzees, have learned to make chopping tools out of rocks with considerable proficiency, though not up to human skills. Chimps' tool-making disadvantage largely derives from having large hands that can't manipulate objects as well or generate as much striking force as human hands can, Toth says. Louis J. Sheehan, Esquire .
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