martes, 15 de marzo de 2011

Better Brain Wiring Linked to Family Genes


Better Brain Wiring Linked to Family Genes

ScienceDaily (Mar. 15, 2011) — How well our brain functions is largely based on our family's genetic makeup, according to a University of Melbourne led study. The study published in The Journal of Neuroscience provides the first evidence of a genetic effect on how 'cost-efficient' our brain network wiring is, shedding light on some of the brain's make up.
Lead author Dr Alex Fornito from the Melbourne Neuropsychiatry Centre at the University of Melbourne said the findings have important implications for understanding why some people are better able to perform certain tasks than others and the genetic basis of mental illnesses and some neurological diseases.
He said how the brain's network is organized has been a mystery to scientists for years. "The brain is an extraordinarily complex network of billions of nerve cells interconnected by trillions of fibers," he said.
"The brain tries to maximize its bang-for-buck by striking a balance between making more connections to promote efficient communication and minimizing the "cost" or amount of wiring required to make these connections. Our findings indicate that this balance, called 'cost-efficiency', has a strong genetic basis."
"Ultimately, this research may help us uncover which specific genes are important in explaining differences in cognitive abilities, risk for mental illness and neurological diseases such as schizophrenia and Alzheimer's disease, leading to new gene-based therapies for these disorders."
"Although genes play a major role in brain function, the environment and other factors contribute to when things go wrong in cases of mental illness and other brain disorders," he said.
The research team, which included scientists at the Universities of Queensland and Cambridge, UK compared the brain scans of 38 identical and 26 non-identical twins from the Australian Twin Registry.
Using new techniques, the researchers were able to construct detailed maps of each person's brain network and measured the cost-efficiency of network connections for the entire brain, as well as for specific brain regions.
"We found that people differed greatly in terms of how cost-efficient the functioning of their brain networks were, and that over half of these differences could be explained by genes," said Dr Fornito.
Across the entire brain, more than half (60%) of the differences between people could be explained by genes. Some of the strongest effects were observed for regions of the prefrontal cortex which play a vital role in planning, strategic thinking, decision-making and memory.
Previous work has shown that people with more efficient brain connections score higher on tests of intelligence, and that brain network cost-efficiency is reduced in people with schizophrenia, particularly in the prefrontal cortex.
"This exciting discovery opens up a whole new area of research focus for scientists around the world," he said.
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Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Melbourne.

Journal Reference:
  1. A. Fornito, A. Zalesky, D. S. Bassett, D. Meunier, I. Ellison-Wright, M. Yucel, S. J. Wood, K. Shaw, J. O'Connor, D. Nertney, B. J. Mowry, C. Pantelis, E. T. Bullmore. Genetic Influences on Cost-Efficient Organization of Human Cortical Functional NetworksJournal of Neuroscience, 2011; 31 (9): 3261 DOI: 10.1523/JNEUROSCI.4858-10.2011

Science Times: Animals


Science Times: Animals
Animals and people. We have always been bound together. Humans are animals, after all. And each new bit of scientific research adds weight and complexity to our genetic intimacy, not just with primates, but with distant relatives like fruit flies and sponges. We share behaviors. We share homes and habitats. We consume each other. Mostly we eat them, a moral quandary for many people. But we still do feed multitudes of parasites, mosquitoes and the odd shark. This issue of Science Times is devoted to our many bonds with animals, and also to the distance between us and them. No other animal makes operas or nuclear weapons. How did we become so different? What made us human?
Jason Holley
Animals and people. We have always been bound together. Humans are animals, after all. And each new bit of scientific research adds weight and complexity to our genetic intimacy, not just with primates, but with distant relatives like fruit flies and sponges. We share behaviors. We share homes and habitats. We consume each other. Mostly we eat them, a moral quandary for many people. But we still do feed multitudes of parasites, mosquitoes and the odd shark. This issue of Science Times is devoted to our many bonds with animals, and also to the distance between us and them. No other animal makes operas or nuclear weapons. How did we become so different? What made us human?
Christopher Silas Neal

The Creature Connection

Our love for animals can be traced to our capacity to infer the mental states of others, which archaeological evidence suggests emerged more than 50,000 ago.

From Single Cells, a Vast Kingdom Arose

The beginning of animals is one of the more mysterious episodes in the history of life, and intermediate species are extinct.
ESSAY

No Face, but Plants Like Life Too

Vegetable behavior, and other ruminations on what we kill so we can eat.

Supremacy of a Social Network

The ability to cooperate, to make individuals subordinate their strong sense of self-interest to the needs of the group, lies at the root of human achievement.

Emotional Power Broker of the Modern Family

Pets alter not only a family’s routines but also its hierarchy, social rhythm and web of relationships.
A polydactyl “Hemingway cat.”

For Whom the Cell Mutates: The Origins of Genetic Quirks

While the origins of the cats at Hemingway’s longtime home in Key West, Fla., remain murky, the cause of their polydactyly is no longer a mystery.
Earthquake in Japan
The No. 3 reactor building of the Fukushima Daiichi nuclear plant burned Monday after a blast following an earthquake and tsunami in this satellite image.

Japan Faces Potential Nuclear Disaster as Radiation Levels Rise

Japan faced the likelihood of a catastrophic nuclear accident after an explosion further damaged one of the crippled reactors and a fire at another spewed large amounts of radioactive material into the air.

A Look at the Mechanics of a Partial Meltdown

Fuel rods must be completely covered in cooling water if they are not to overheat, but overheating does not immediately lead to actual melting.

INTERACTIVE FEATURE: How Shifting Plates Caused the Earthquake and Tsunami in Japan

Diagram and maps showing what caused the Japan earthquake and tsunami.

INTERACTIVE MAP: Map of the Damage From the Japanese Earthquake

An interactive map and photographs of places in Japan that were damaged by the March 11 earthquake and subsequent tsunami.

INTERACTIVE FEATURE: How a Reactor Shuts Down and What Happens in a Meltdown

What happens to a reactor in a meltdown.

Quake Moves Japan Closer to U.S. and Alters Earth’s Spin

The unbuckling of two tectonic plates shifted Japan’s coastline by up to 13 feet, and a 250-mile-long section dropped in altitude by about two feet.
More Science News

Physicist’s Jailing Is Veiled in Mystery

More than 500 days after Adlène Hicheur, a French-Algerian scientist, was detained by French authorities, no charges have been brought.
SMARTER THAN YOU THINK

Poker Bots Invade Online Gambling

Card-playing software is now good enough to win tens of thousands of dollars on major poker sites, and human players aren’t happy about it.

lunes, 14 de marzo de 2011

Chemical Composition of the Human Body


Chemical Composition of the Human Body

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The table below shows the approximate quantities of the chemical elements present in an average 70kg man.
Element            
Amount / kg 
Amount / Mol.
Oxygen
  43
2700
Carbon
16
1300
Hydrogen
7
7000
Nitrogen
1
.8
130
Calcium
1
.0
25
Phosphorus
0
.78
25
Sulphur
0
.14
4
.4
Potassium
0
.14
3
.6
Sodium
0
.10
4
.3
Chlorine
0
.095
2
.7
Magnesium
0
.019
0
.78
Silicon
0
.018
0
.64
Iron
0
.0042
0
.075
Fluorine
0
.0026
0
.14
Zinc
0
.0023
0
.035
Rubidium
0
.00032
0
.0037
Strontium
0
.00032
0
.0037
Bromine
0
.00020
0
.0025
Lead
0
.00012
0
.00058
Copper
0
.000072
0
.0011
Aluminium
0
.000061
0
.0023
Cadmium
0
.000050
0
.00044
Boron
< 0
.000048
0
.0044
Barium
0
.000022
0
.00016
Tin
< 0
.000017
0
.00014
Iodine
0
.000013
0
.00010
Manganese
0
.000012
0
.00022
Nickel
0
.000010
0
.00017
Gold
< 0
.000010
0
.000051
Molybdenum
< 0
.0000093
0
.000097
Chromium
< 0
.0000018
0
.000035
Caesium
0
.0000015
0
.000011
Cobalt
0
.0000015
0
.000025
Uranium
0
.00000009
0
.00000038
Beryllium
0
.000000036
0
.0000040
Radium
3.1×10-14
1.4×10-13
            

Chemical composition of the human body by mass
Pie chart showing chemical composition of human body by mass

“SEMANA DEL CEREBRO”

La Sociedad Mexicana de Ciencias Fisiológicas (SMCF) y el 

Capítulo Mexicano de la Society for Neuroscience (SFN) invitan a 
las actividades que se llevarán a cabo en la Facultad de Medicina, 
U.N.A.M., como parte de la
“SEMANA DEL CEREBRO”
del 14 al 18 de marzo 2011
 Concurso de Carteles
 Exposición de Carteles
 Conferencias en el Auditorio Guevara Rojas, 12:00 a 14:00 hrs.
Lunes 14 - Los sistemas cerebrales del placer.
Dr. Oscar Prospéro García, Fac. Medicina, UNAM.
Martes 15 - ¿Como la arquitectura de nuestro cerebro determina quienes 
somos?
Dr. Victor Rodriguez Molina, Fac. Medicina, UNAM y Fac. Medicina, UAEM.
Miércoles 16 - Papel de la inflamación y de las citoquinas pro-inflamatorias en 
el mantenimiento de la actividad glial y muerte neuronal en el parkinsonismo.
Dra. María Trinidad Herrero. Universidad de Murcia, España.
Jueves 17 - Neurobiología y neuroquímica del amor: Diferencia del cerebro 
femenino y masculino asociadas al enamoramiento.
Dr. Eduardo Calixto González. Fac. Medicina, UNAM e Instituto Nacional de 
Psiquiatría.
Viernes 18 - Naturalizar la conciencia.
Dr. Martín Bonfil, UNIVERSUM, UNAM.
14:00 hrs. Premiación de carteles y clausura.
Coordinación e informes:
Francisco Estrada (fesro@hotmail.com)
Virginia Inclán (inclan@servidor.unam.mx)
Luz Navarro (lnavarro@servidor.unam.mx)
Leticia Verdugo (leticia@servidor.unam.mx)