Thursday, November 29, 2012
Auditory test predicts coma awakening
Patients whose sound discrimination improved in 48 hours eventually awoke.
A coma patient’s chances of surviving and waking up could be predicted by changes in the brain’s ability to discriminate sounds, new research suggests.
Recovery from coma has been linked to auditory function before, but it wasn’t clear whether function depended on the time of assessment. Whereas previous studies tested patients several days or weeks after comas set in, a new study looks at the critical phase during the first 48 hours. At early stages, comatose brains can still distinguish between different sound patterns,. How this ability progresses over time can predict whether a coma patient will survive and ultimately awaken, researchers report.
“It’s a very promising tool for prognosis,” says neurologist Mélanie Boly of the Belgian National Fund for Scientific Research, who was not involved with the study. “For the family, it’s very important to know if someone will recover or not.”
A team led by neuroscientist Marzia De Lucia of the University of Lausanne in Switzerland studied 30 coma patients who had experienced heart attacks that deprived their brains of oxygen. All the patients underwent therapeutic hypothermia, a standard treatment to minimize brain damage, in which their bodies were cooled to 33° Celsius for 24 hours.
De Lucia and colleagues played sounds for the patients and recorded their brain activity using scalp electrodes — once in hypothermic conditions during the first 24 hours of coma, and again a day later at normal body temperature. The sounds were a series of pure tones interspersed with sounds of different pitch, duration or location. The brain signals revealed how well patients could discriminate the sounds, compared with five healthy subjects.
After three months, the coma patients had either died or awoken. All the patients whose discrimination improved by the second day of testing survived and awoke from their comas. By contrast, many of those whose sound discrimination deteriorated by the second day did not survive. The results were reported online November 12 in Brain.
Psychophysiologist Geert van Boxtel of Tilburg University, in the Netherlands, found it surprising that “irrespective of outcome, at the first recording, all of the patients showed signs of auditory discrimination.” This, De Lucia says, suggests that residual auditory function itself does not predict recovery; rather, it’s the progression of function over time that is predictive.
The study couldn’t distinguish whether auditory function initially was preserved due to the hypothermia treatment or was related merely to the early stage of coma. But the scientists speculate that distracting neural jabber may have been reduced during the hypothermia, making it easier for the patients’ brains to separate sounds.
De Lucia and her colleagues are now running a follow-up study with 120 coma patients, to see whether the results can be replicated in a bigger population. “This test could give information about patients who will survive during the first two days of coma, when doctors can still make decisions about treatment,” De Lucia says.
A coma patient’s chances of surviving and waking up could be predicted by changes in the brain’s ability to discriminate sounds, new research suggests.
Recovery from coma has been linked to auditory function before, but it wasn’t clear whether function depended on the time of assessment. Whereas previous studies tested patients several days or weeks after comas set in, a new study looks at the critical phase during the first 48 hours. At early stages, comatose brains can still distinguish between different sound patterns,. How this ability progresses over time can predict whether a coma patient will survive and ultimately awaken, researchers report.
“It’s a very promising tool for prognosis,” says neurologist Mélanie Boly of the Belgian National Fund for Scientific Research, who was not involved with the study. “For the family, it’s very important to know if someone will recover or not.”
A team led by neuroscientist Marzia De Lucia of the University of Lausanne in Switzerland studied 30 coma patients who had experienced heart attacks that deprived their brains of oxygen. All the patients underwent therapeutic hypothermia, a standard treatment to minimize brain damage, in which their bodies were cooled to 33° Celsius for 24 hours.
De Lucia and colleagues played sounds for the patients and recorded their brain activity using scalp electrodes — once in hypothermic conditions during the first 24 hours of coma, and again a day later at normal body temperature. The sounds were a series of pure tones interspersed with sounds of different pitch, duration or location. The brain signals revealed how well patients could discriminate the sounds, compared with five healthy subjects.
After three months, the coma patients had either died or awoken. All the patients whose discrimination improved by the second day of testing survived and awoke from their comas. By contrast, many of those whose sound discrimination deteriorated by the second day did not survive. The results were reported online November 12 in Brain.
Psychophysiologist Geert van Boxtel of Tilburg University, in the Netherlands, found it surprising that “irrespective of outcome, at the first recording, all of the patients showed signs of auditory discrimination.” This, De Lucia says, suggests that residual auditory function itself does not predict recovery; rather, it’s the progression of function over time that is predictive.
The study couldn’t distinguish whether auditory function initially was preserved due to the hypothermia treatment or was related merely to the early stage of coma. But the scientists speculate that distracting neural jabber may have been reduced during the hypothermia, making it easier for the patients’ brains to separate sounds.
De Lucia and her colleagues are now running a follow-up study with 120 coma patients, to see whether the results can be replicated in a bigger population. “This test could give information about patients who will survive during the first two days of coma, when doctors can still make decisions about treatment,” De Lucia says.
Genetic diversity exploded in recent millennia
Vast number of human DNA variants arose only in the past 5,000 years.
A new look at living people’s DNA reveals that the human genome just isn’t what it was in Neolithic times.
Most of the genetic quirks people carry today popped up within the last 5,000 years or so, researchers report online November 28 in Nature.Human populations exploded from no more than a few million to 7 billion, thanks largely to the rise of agriculture.
Researchers examined more than 15,000 genes in each of 6,515 people of European-American or African-American ancestry, looking for genetic variants. Previously, the team reported finding a plethora of rare genetic variants in a smaller sample. Now, the researchers have been able to date when most of the variants arose.
Of the 709,816 genetic variants found in European-Americans in the study, more than 81 percent arose in the past 5,000 years, the researchers determined. African-Americans in the study collectively carried 643,128 genetic variants, more than 58 percent of which are less than 5,000 years old. That may seem like a long time, but it’s only about 5 percent of the time humans have existed in modern form, says study coauthor Joshua Akey, a geneticist at the University of Washington in Seattle.
Although the human population explosion has been obvious from a demographer’s point of view, that growth has been all but invisible to geneticists studying common genetic variants. It takes time for a genetic variant, if it’s not discarded, to rise to prominence. Common variants — those found in 5 percent or more of the population — tend to be old tweaks that have stuck around, usually because they usually don’t have a big effect on health.
The new study will give scientists a clear picture of the stamp the recent population explosion has left on human genes, says Sarah Tishkoff, a geneticist at the University of Pennsylvania in Philadelphia. The work may help track down variants that affect people’s risk of developing common diseases, she says. Currently, by linking common variants to illness, scientists can explain only a small fraction of the genetic role in disease risk.
When humans migrated out of Africa about 70,000 years ago, they carried with them mutated versions of genes that natural selection might have weeded out had they stayed in Africa, the researchers found. By chance, many of these potentially harmful mutations endured in the migrants, and then were passed along to myriad descendants as the emigrants began to expand their populations in Europe. But many other potentially harmful mutations — if carried by only a small fraction of ancient migrants — were lost as small groups of humans trickled out of the African continent to populate the rest of the world.
In European-Americans, variants predicted to have harmful effects tend to be younger than those in African-Americans — 3,000 years old on average in European-Americans versus 6,200 years old in African-Americans. (African populations have grown in recent millennia, but not as much as populations outside Africa, which went from zero to billions in less than 100,000 years.) Evolution has not had time to purge the newest harmful changes in either group, and many of them pack a wallop in terms of disease risk.
Even though most of the genetic variants the researchers uncovered are predicted to change the workings of proteins in harmful ways, some of the genetic tweaks might someday give humans an evolutionary advantage, says Akey. Exactly which variants turn out to be good and which will cause trouble is unpredictable. “It’s hard to speculate on the genetic health of our species when the environment is changing,” he says. “We’ll have to check back in a few thousand years.” But, he adds, one thing is for certain: “If we stop changing, we’re evolutionarily dead.”
A new look at living people’s DNA reveals that the human genome just isn’t what it was in Neolithic times.
Most of the genetic quirks people carry today popped up within the last 5,000 years or so, researchers report online November 28 in Nature.Human populations exploded from no more than a few million to 7 billion, thanks largely to the rise of agriculture.
Researchers examined more than 15,000 genes in each of 6,515 people of European-American or African-American ancestry, looking for genetic variants. Previously, the team reported finding a plethora of rare genetic variants in a smaller sample. Now, the researchers have been able to date when most of the variants arose.
Of the 709,816 genetic variants found in European-Americans in the study, more than 81 percent arose in the past 5,000 years, the researchers determined. African-Americans in the study collectively carried 643,128 genetic variants, more than 58 percent of which are less than 5,000 years old. That may seem like a long time, but it’s only about 5 percent of the time humans have existed in modern form, says study coauthor Joshua Akey, a geneticist at the University of Washington in Seattle.
Although the human population explosion has been obvious from a demographer’s point of view, that growth has been all but invisible to geneticists studying common genetic variants. It takes time for a genetic variant, if it’s not discarded, to rise to prominence. Common variants — those found in 5 percent or more of the population — tend to be old tweaks that have stuck around, usually because they usually don’t have a big effect on health.
The new study will give scientists a clear picture of the stamp the recent population explosion has left on human genes, says Sarah Tishkoff, a geneticist at the University of Pennsylvania in Philadelphia. The work may help track down variants that affect people’s risk of developing common diseases, she says. Currently, by linking common variants to illness, scientists can explain only a small fraction of the genetic role in disease risk.
When humans migrated out of Africa about 70,000 years ago, they carried with them mutated versions of genes that natural selection might have weeded out had they stayed in Africa, the researchers found. By chance, many of these potentially harmful mutations endured in the migrants, and then were passed along to myriad descendants as the emigrants began to expand their populations in Europe. But many other potentially harmful mutations — if carried by only a small fraction of ancient migrants — were lost as small groups of humans trickled out of the African continent to populate the rest of the world.
In European-Americans, variants predicted to have harmful effects tend to be younger than those in African-Americans — 3,000 years old on average in European-Americans versus 6,200 years old in African-Americans. (African populations have grown in recent millennia, but not as much as populations outside Africa, which went from zero to billions in less than 100,000 years.) Evolution has not had time to purge the newest harmful changes in either group, and many of them pack a wallop in terms of disease risk.
Even though most of the genetic variants the researchers uncovered are predicted to change the workings of proteins in harmful ways, some of the genetic tweaks might someday give humans an evolutionary advantage, says Akey. Exactly which variants turn out to be good and which will cause trouble is unpredictable. “It’s hard to speculate on the genetic health of our species when the environment is changing,” he says. “We’ll have to check back in a few thousand years.” But, he adds, one thing is for certain: “If we stop changing, we’re evolutionarily dead.”
Amazon deforestation drops to record low
The rate of deforestation in the Brazilian Amazon has fallen to yet another record low this year. The new figure, a staggering 27% drop from 2011, exceeded the expectations of the Brazilian government and puts the country on the verge of fulfilling the promise it made at the COP 15 climate meeting in Copenhagen in 2009: to slash the rate of destruction of the world’s largest tropical forest by 80% by 2020.
According to preliminary calculations released on Tuesday, 27 November, by Inpe (National Institute for Space Research), 4,656 square kilometres of forest were clear-cut in the Amazon over the 12 months from August 2011 to July 2012, compared to 6,418 km2 from August 2010 to July 2011. The estimate was based on fine-resolution satellite images that capture nearly all the deforestation hotspots. The figures are always reviewed in the following year, but the final number never strays too much from the December estimate.
The 2012 rate is only about 4% higher than the 2020 target of 3,907 km2 that Brazil volunteered as part of its commitment to the 2009 Copenhagen Accord. It was also a rare piece of good news as diplomats from 194 nations gathered in Doha, Qatar, for yet another attempt to salvage multilateral climate talks and negotiate the terms of an extension of the Kyoto Protocol. Ambassador André Corrêa do Lago, Brazil’s chief negotiator at COP 18, was applauded upon announcing the figure at the plenary. “Once again, the good news on the climate agenda comes from Brazil,” said Brazilian environment minister, Izabella Teixeira, in an interview with Nature after releasing the Inpe data. “What we need now is that developed countries also deliver on their promises, so that the planet can effectively cope with the challenge of climate change,” she said.
Nailing down the remaining 4% of the target will be no easy task for Brazil, however. High prices of grain and gold in the international market, combined with a weakened Forest Code by the Congress, have caused clear-cutting to go up by 220% in August, the first month of the 2013 data series. Teixeira says that the picture for September and October is much brighter, but Imazon, an environmental think tank that uses a different methodology to independently calculate deforestation rates, has seen a 125% increase from August to October compared to August–October 2011.
Money for fighting climate change is also due to vanish in the South American nation. Earlier this month, the Congress passed a law that redistributes royalties from the country’s booming oil industry that were used to feed the national Climate Fund. The new law, now awaiting sanction by president Dilma Rousseff, has the potential to eliminate up to US$500 million a year in funds that should finance climate adaptation and mitigation.
According to preliminary calculations released on Tuesday, 27 November, by Inpe (National Institute for Space Research), 4,656 square kilometres of forest were clear-cut in the Amazon over the 12 months from August 2011 to July 2012, compared to 6,418 km2 from August 2010 to July 2011. The estimate was based on fine-resolution satellite images that capture nearly all the deforestation hotspots. The figures are always reviewed in the following year, but the final number never strays too much from the December estimate.
The 2012 rate is only about 4% higher than the 2020 target of 3,907 km2 that Brazil volunteered as part of its commitment to the 2009 Copenhagen Accord. It was also a rare piece of good news as diplomats from 194 nations gathered in Doha, Qatar, for yet another attempt to salvage multilateral climate talks and negotiate the terms of an extension of the Kyoto Protocol. Ambassador André Corrêa do Lago, Brazil’s chief negotiator at COP 18, was applauded upon announcing the figure at the plenary. “Once again, the good news on the climate agenda comes from Brazil,” said Brazilian environment minister, Izabella Teixeira, in an interview with Nature after releasing the Inpe data. “What we need now is that developed countries also deliver on their promises, so that the planet can effectively cope with the challenge of climate change,” she said.
Nailing down the remaining 4% of the target will be no easy task for Brazil, however. High prices of grain and gold in the international market, combined with a weakened Forest Code by the Congress, have caused clear-cutting to go up by 220% in August, the first month of the 2013 data series. Teixeira says that the picture for September and October is much brighter, but Imazon, an environmental think tank that uses a different methodology to independently calculate deforestation rates, has seen a 125% increase from August to October compared to August–October 2011.
Money for fighting climate change is also due to vanish in the South American nation. Earlier this month, the Congress passed a law that redistributes royalties from the country’s booming oil industry that were used to feed the national Climate Fund. The new law, now awaiting sanction by president Dilma Rousseff, has the potential to eliminate up to US$500 million a year in funds that should finance climate adaptation and mitigation.
Mago de Oz new CD: Hechizos,Pócimas y Brujería
Here you have some of the song of the incredible new CD of the Spanish Rock/Metal musical group Mago de Oz:
Enjoy it !!
Enjoy it !!
Monday, November 12, 2012
Sunday, November 11, 2012
Funny explanation about Internet and Intranet
Here you have a very funny explanation about the Internet and the Intranet.
Enjoy it!
Enjoy it!
Visual explanation about internet and intranet
Here you have an explanation about the differences between Internet and Intranet in Spanish.
Internet vs. Intranet
An intranet is a computer network used to share information, operational systems, or
computing services within an organization. The term is used in contrast to internet, a network between
organizations, and instead refers to a network within an organization.
Sometimes, the term refers only to the organization's internal website, but may
be a more extensive part of the organization's information technology
infrastructure, and may be composed of multiple local area networks.
In the next days I will post more information about this topic!!
 |
| Intranet |
The
Internet is a global system of
interconnected computer networks that serves billions
of users worldwide. It is a network of
networks that consists of millions of private, public, academic,
business, and government networks, of local to global scope, that are linked by
a broad array of electronic, wireless and optical networking technologies.
 |
| Internet |
Some intranet systems use internet to comunicate or to share information with the organization.
In the next days I will post more information about this topic!!
Friday, November 9, 2012
Hi everyone!
Hi, my name is Javier and this is my blog. In the next days I will post information and news about topics related to science, technology, nature and traveling, in Spain and arround the world.
Enjoy it!
"Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves." ~John Muir
"The World is a book, and those who do not travel read only a page." ~St. Augustine
Enjoy it!
"Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves." ~John Muir
"The World is a book, and those who do not travel read only a page." ~St. Augustine
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