viernes, 31 de agosto de 2012

We need your help today to ensure that this fight continues

ORIGINAL: Amazon Watch

This summer I was on the ground with the Amazon Watch team standing with communities on the front lines of the fight to stop the Belo Monte Dam. I dug my toes into the red clay banks of the early stages of construction and watched as 300 indigenous and local people ripped through the earthen barricade in desperate attempt to free the mighty Xingu River, if only for a moment. We need your help today to ensure that this fight continues.>

The last few weeks have been marked by glorious moments of victory and new challenges. Our efforts were validated when a Brazilian judge ordered the immediate halt to construction and suspended all activities at the dam site. Hope!

This was a true win, led by indigenous and local communities and won by the collective efforts of citizens from around the world standing with them...and by you.

As we suspected might happen, President Dilma pressured a member of the Brazilian Supreme Court resulting in Chief Justice Carlos Ayres Britto overturning the decision without giving essential consideration to indigenous rights implications. Back on the roller coaster.

The Federal Public Prosecutor's office is expected to appeal this decision and demand a review by the full Supreme Court. They must uphold the historic decision that suspended this highly controversial project just two weeks ago. Help us make this possible.>

Now is THE moment to dig our toes deep into that red clay and stand steadfast, collectively, in resistance to the Belo Monte Dam. Already over a million of you from around the globe have rallied behind this effort. With your support the people of the Xingu can win.>

For the Amazon,

Atossa Soltani
Executive Director

Invitación a la 8a Rueda de Negocios Tecnnova, Medellín 24 y 25 septiembre

ORIGINAL: Tecnnova



Contralora alerta por riesgos de daño ambiental en los páramos

ORIGINAL: El Colombiano
Colprensa
27 de agosto de 2012

Foto: El Colombiano
La Contralora General de la República, Sandra Morelli Rico, advirtió al ministro de Ambiente, Frank Pearl y al Gobierno Nacional por los riesgos de daño ambiental sobre los páramos del país por la ejecución de proyectos, obras y actividades de explotación y exploración minera, labores agropecuarias, de explotación maderera e incluso de construcción.

El ente fiscal, consideró que se podrían estar presentando actividades de exploración minera en zonas prohibidas y es urgente que las autoridades ambientales protejan las áreas de su jurisdicción. Según algunos académicos se pueden generar daños ambientales sobre la calidad del agua, el paisaje y los ecosistemas de los páramos.

Según esta alerta, la afectación de los páramos por la ejecución de obras, proyectos y actividades de diverso tipo puede poner en riesgo a :

  • Bogotá, con los páramos de Chingaza y Sumapaz>
  • Medellín, páramo de Belmira;>
  • Bucaramanga y Cúcuta, páramo de Santurbán
  • Tunja, páramo de Rabanal
  • Ibagué, Armenia, Pereira y Manizales, con los páramos del Parque de los Nevados y en
  • Popayán el páramo de Puracé.
La función de advertencia de la Contraloría, también incluye a la directora general del Instituto de Investigación de Recursos Biológicos Alexander von Humboldt , los miembros de los Consejos Directivos de las Corporaciones Autónomas Regionales y en general los directores de las autoridades ambientales.

También se señaló que existen irregularidades en el otorgamiento o inscripción en el Registro Minero de títulos luego de la expedición de la Ley 1382 de 2010,que prohibió de manera expresa la exploración y explotación minera en los páramos, precisó el ente fiscal

Autoridades evalúan causas del desastre ecológico en Mallorquín

ORIGINAL: El Heraldo
Por Marly Obredor Salazar

Una comisión de la Gerencia de la Contraloría General de la República recorrió la ciénaga.
Establecer con claridad las causas de la alteración del equilibrio del ecosistema de la ciénaga de Mallorquín, que desencadenó en la mortandad de peces reportada ayer, es la prioridad de las autoridades ambientales de Barranquilla.

De acuerdo a lo expresado por el jefe de Control y Vigilancia del Damab, Ángel Romo Padilla, un equipo técnico de la entidad ambiental diseñó un programa de muestreo para establecer la calidad del agua de la ciénaga y la que llega del arroyo León.

Así mismo, programó un recorrido para analizar los vertimientos de agua que realizan diferentes empresas a esa cuenca. “Debemos identificar cuáles empresas realizan vertimientos en la ciénaga, para luego establecer las características físico-química de los mismos”, expresó el funcionario.

Romo indicó que de acuerdo a las características que se notaron en el agua (color verdoso, proliferación de algas), esto podría darse por el aporte de nutrientes como fósforo y nitrógeno.No me gustaría especular, pero estos elementos podrían estar presentes en el agua que salen de la Edar (Estación Depuradora de Aguas Residuales del Distrito de Barranquilla), ubicada en el barrio El Pueblo”.

El ingeniero ambiental dijo que los análisis de laboratorio deberán comprobar o descartar esta hipótesis. Indicó que precisamente el Damab financió un proyecto de optimización de la Edar.

Esta teoría coincide con la denuncia realizada por Luz Helena de Sarmiento, líder de la veeduría ciudadana conformada por las comunidades de Puerto Colombia, quien cuestionó si la laguna de oxidación del Pueblito tiene la capacidad requerida para tratar las aguas residuales provenientes de las empresas instaladas en el sector de Juan Mina.

El ingeniero Ramón Hemer, gerente de Operaciones de la empresa Triple A, que tiene a su cargo la Estación de Aguas Residuales, descartó de plano que el agua que sale de la Edar esté ocasionando el daño ecológico.

El funcionario dijo que el agua que es tratada en la Edar es de uso doméstico y no industrial, “nuestro comportamiento ha sido el mismo durante los 12 años de funcionamiento de la estación, en cuanto al agua de entrada y al agua de salida. Mucho más ahora que el Damab adelanta el proyecto de optimización para eliminar nitrógeno y fósforo”, insistió.

El representante de la Triple A, empresa que apoyó la recolección de los peces muertos de la Ciénaga, dijo que se inclina más hacia la teoría que indica que las aguas se encontraban estancadas a la altura del puente sobre la 51B y que al correr, ocasionaron la mortandad.

También pidió que se revisen los canales que intercomunican las aguas de la ciénaga con el Río Magdalena, pues tiene conocimiento que los mismo se encuentran taponados, lo que también podría afectar el equilibrio natural de ese cuerpo.

Ayer, una comisión de la Gerencia de la Contraloría General de la República, liderada por Manuel Díaz Jimeno, se hizo presente en la zona y realizó un recorrido por la ciénaga, al tiempo que escuchó las inquietudes de los pescadores.

Arctic Sea Ice Hits New and Early Summer Low for Satellite Era

ORIGINAL: NYTimes
August 27, 2012

Sunsets started to tease the Arctic horizon as scientists on board the U.S. Coast Guard Cutter Healy headed south in the Chukchi Sea during the final days collecting ocean data for the 2011 ICESCAPE mission.  The ICESCAPE mission, or "Impacts of Climate on Ecosystems and Chemistry of the Arctic Pacific Environment," is a NASA shipborne investigation to study how changing conditions in the Arctic affect the ocean's chemistry and ecosystems. The bulk of the research took place in the Beaufort and Chukchi seas in summer 2010 and 2011. Credit: NASA/Kathryn Hansen

11:44 p.m. | Updates from several scientists below |
The planet is warming and the Arctic is warming the most, as long foreseen by scientists in a climate system pushed out of balance through the rapid buildup of heat-trapping greenhouse gases in the atmosphere. One result is greater loss of Arctic sea ice in the annual summer warmup.

Today, the National Snow and Ice Data Center announced that the annual summer retreat of Arctic Ocean sea ice had reached a new low for the 33-year satellite era of careful monitoring (1.58 million square miles, or 4.1 million square kilometers), and there is still another week or two of melting before the typical summer ice minimum occurs.

This quote in the release from Walt Meier of the ice center efficiently encapsulates the context:
"By itself it’s just a number, and occasionally records are going to get set. But in the context of what’s happened in the last several years and throughout the satellite record, it’s an indication that the Arctic sea ice cover is fundamentally changing."

The animated sea-ice imagery above — from one of two autonomous cameras set on ice near the North Pole each spring — gives a close-focus view of the slushy conditions that develop on the shifting ice when the summer sun is at its peak. (This is part of the annual North Pole Environmental Observatory project that I reported on in 2003; the cameras drift with the ice through the summer and are currently over the shoulder of Greenland. You can track their position here.)

Justin Gillis has more on this development over on the news side of The Times. This excerpt echoes the thinking of quite a few ice researchers I’ve interviewed over recent years:

“It’s hard even for people like me to believe, to see that climate change is actually doing what our worst fears dictated,” said Jennifer A. Francis, a Rutgers University scientist who studies the effect of sea ice on weather patterns. “It’s starting to give me chills, to tell you the truth.”

Still, there are many other veteran sea-ice scientists (this is not false balance) who note that the complexity of this system has consistently defied predictions in either direction (see this year’s Sea Ice Outlook forecasts to get the range of forecasts).

A 12-Year View of the Global Pulse of Fire

ORIGINAL: NYTimes
August 30, 2012

Record Temperatures and Wildfires in Eastern Russia. Photo: NASA. http://www.nasa.gov/mission_pages/fires/main/world/20120828-russia.html
A recent reader comment about this year’s season of heat and wildfire in Siberia prompted me to scan NASA Web pages for relevant data and images. I found this fascinating 12-year animation showing the annual shifts in frequency and distribution of fires — both wild and human-set — around the planet. Here’s some of the space agency’s explainer, with a link to the rest:


The fire maps show the locations of actively burning fires around the world on a monthly basis, based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The colors are based on a count of the number (not size) of fires observed within a 1,000-square-kilometer area. White pixels show the high end of the count —as many as 100 fires in a 1,000-square-kilometer area per day. Yellow pixels show as many as 10 fires, orange shows as many as 5 fires, and red areas as few as 1 fire per day.

Some of the global patterns that appear in the fire maps over time are the result of natural cycles of rainfall, dryness, and lightning. For example, naturally occurring fires are common in the boreal forests of Canada in the summer. In other parts of the world, the patterns are the result of human activity. For example, the intense burning in the heart of South America from August-October is a result of human-triggered fires, both intentional and accidental…. Read more. 

Fascinating NASA Earth Observatory animation shows the annual pulsing of fires (number, not size!) around the world. The space agency's description:

On Earth, something is always burning. Wildfires are started by lightning or accidentally by people, and people use controlled fires to manage farmland and pasture and clear natural vegetation for farmland. Fires can generate large amounts of smoke pollution, release greenhouse gases, and unintentionally degrade ecosystems. But fires can also clear away dead and dying underbrush, which can help restore an ecosystem to good health. In many ecosystems, including boreal forests and grasslands, plants have co-evolved with fire and require periodic burning to reproduce.

The fire maps show the locations of actively burning fires around the world on a monthly basis, based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. The colors are based on a count of the number (not size) of fires observed within a 1,000-square-kilometer area. White pixels show the high end of the count —as many as 100 fires in a 1,000-square-kilometer area per day. Yellow pixels show as many as 10 fires, orange shows as many as 5 fires, and red areas as few as 1 fire per day.

Some of the global patterns that appear in the fire maps over time are the result of natural cycles of rainfall, dryness, and lightning. For example, naturally occurring fires are common in the boreal forests of Canada in the summer. In other parts of the world, the patterns are the result of human activity. For example, the intense burning in the heart of South America from August-October is a result of human-triggered fires, both intentional and accidental, in the Amazon Rainforest and the Cerrado (a grassland/savanna ecosystem) to the south. Across Africa, a band of widespread agricultural burning sweeps north to south over the continent as the dry season progresses each year. Agricultural burning occurs in late winter and early spring each year across Southeast Asia.


jueves, 30 de agosto de 2012

Un antioqueño es elegido por el MIT entre los 35 innovadores menores de 35 años más destacados del mundo

ORIGINAL Caracol Radio
AGOSTO 23 DE 2012

Este emprendedor diseñó de un dispositivo que cuida de los bebés prematuros, un prototipo que tiene la peculiaridad de adaptarse a las necesidades físicas del mismo. 



El colombiano Juan Sebastián Osorio fue elegido por la revista MIT Technology Review como uno de los 35 jóvenes innovadores menores de 35 años más destacados del mundo, luego de un proceso que se inició a partir de la realización en Medellín, por primera vez en América Latina, de Emtech, el principal encuentro de tecnologías emergentes del mundo.

Es la primera vez que un miembro de la comunidad TR35 de Technology Review en español es elegido para formar parte de los premiados a nivel global, y de esta forma, Juan Sebastián Osorio comparte reconocimiento con profesionales como Mark Zuckerberg, Sergey Brin o Jack Dorsey, que fueron premiados cuando sus carreras aún eran desconocidas.

Juan Sebastián Osorio tendrá la oportunidad de exponer su proyecto en la conferencia Emtech MIT 2012, en Boston, entre el 24 y el 26 del próximo mes de octubre, y consideró que este premio supondrá un “Impulso definitivo a su carrera”, pero también “Para toda una comunidad de innovadores y emprendedores que, desde Colombia y toda Latinoamérica, se está dando a conocer”.

Juan Sebastián Osorio es el creador de un dispositivo que cuida de los bebés prematuros, un prototipo desarrollado por este innovador, que tiene la peculiaridad de adaptarse a las necesidades físicas de los bebés. 

El mecanismo es capaz de detectar problemas en el sistema respiratorio de los recién nacidos prematuros, evitando fallos de medición que pueden resultar fatales.

Esta tecnología, capaz incluso de prevenir la apnea, ayudaría a los hospitales a ahorrar costos y evitaría la hospitalización de los bebés afectados, casi un 85 % de los nacidos antes de las 34 semanas.

La alegría es inmensa, para mí y para toda mi familia”, expresó Juan Sebastián, y destacó que “El premio es una demostración de que en Latinoamérica hay potencial, y que lo más importante de estos países es su capital humano”.

Es la segunda vez que el MIT se fija en la trayectoria de este antioqueño, estudiante de ingeniería biomédica de la Escuela de Ingeniería de Antioquia, Universidad CES. El pasado mes de julio, Osorio era reconocido por la revista MIT Technology Review en español como uno de los diez innovadores colombianos más destacados del país, en la primera edición de los premios TR35 Colombia.

Indígenas se oponen al régimen ecológico de Evo Morales

Agosto 30, 2012

Los indígenas amazónicos defienden la reserva Tipnis y se niegan a aceptar las propuestas del presidente boliviano Evo Morales, quien pretende crear un tramo vial que cruce la Amazonía. Manifiestan que su régimen ecológico es un “atropello a sus derechos Foto: Tomado de Internet
Con el fin de defender los parques naturales de actividades ilegales en territorio boliviano, el presidente Evo Morales creó un régimen ecológico al que se oponen los indígenas de la zona, quienes se oponen a la creación de una carretera que cruza la Amazonía, los nativos manifiestan que es un “atropello” a su comunidad.

"Mediante un nuevo regimiento, el primer regimiento ecológico que se crea hoy acá, se va a defender el medio ambiente y aquí vamos a aprender también a defender los derechos de la Madre Tierra y desde acá se va a planificar cómo defender los parques nacionales", manifestó el mandatario.

"La primera tarea inmediata" de este regimiento será "no permitir ningún nuevo asentamiento en el Parque (..) Isiboro Sécure, no permitir ningún avasallamiento de hermanos indígenas de esta región" aclaró el presidente por lo que las comunidades indígenas no tardaron en oponerse al régimen.

Según la estructura del régimen que lleva el nombre del cacique indígena Juan Maraza, se contempla la creación de la Escuela Ecológica para la Protección de Parques, donde los soldados se capacitarán para defender esos territorios de la explotación ilegal de recursos naturales.

"Es tan importante que los bolivianos y bolivianas sepamos entender sobre el medio ambiente, la naturaleza, la Pachamama, el planeta y por eso decidimos en el Gabinete fundar el regimiento ecológico y una escuela de cuidado del medio ambiente", anunció el presidente Morales.

El régimen ecológico se encargará de proteger los parques de tres acciones específicos:
  • la depredación forestal ilegal,
  • la siembra de la coca y
  • la presencia de avasalladores de tierras en los parques.
Por su parte, Los amazónicos marcharon dos veces en menos de un año contra el proyecto vial y rechazan una consulta del Gobierno en la reserva al respecto porque consideran que los resultados serán manipulados.

También sostienen que si la carretera atraviesa su territorio, habrá una invasión de campesinos de la zona vecina del Chapare, donde se cultiva coca, base para fabricar cocaína.

Morales, que dirige a sindicatos del Chapare, pidió a los campesinos que no cometan el "grave error" de ingresar al parque porque el Gobierno y el nuevo regimiento no permitirán esos asentamientos

Sea Lights Help Seals Hunt in the Dark

ORIGINAL: LiveScience
Charles Choi, LiveScience Contributor
Date: 29 August 2012 Time: 05:01 PM ET


These devices included satellite tags that relayed temperature and other data, as well as sensors that monitored light and recorded the depth and lengths of dives. Shown here, researchers Kevin Coustaut, Nory El Ksabi and Jade Vacquie Garcia. CREDIT: Elodie Camprasse. 

The glow that certain fish give off may help the world's largest seals hunt them down.

Southern elephant seals spend about 10 months in the southern Indian Ocean, coming ashore only to breed and molt. They forage over broad distances, during which time they dive continuously, sometimes deeper than 4,900 feet (1,500 meters).

The deep, dark ocean is a challenging place to find prey. Whales use echolocation — the biological equivalent of sonar — to scan for potential food, while penguins rely on scent. However, it remained uncertain how southern elephant seals foraged in the deep sea. Scientists now have a better idea after attaching electronic devices to some of them.

Shining a light on prey

Southern elephant seals are the world's largest seals. "Standing next to a male over 3 tonnes (6,600 pounds) and 4 meters (13 feet) long is particularly impressive," researcher Jade Vacquié-Garcia, a marine biologist at the Center for Biological Studies of Chize in France, told LiveScience.

The researchers analyzed a total of 3,386 dives. They deduced that seals found good areas to forage based on how fast they ascended from and dove back to those areas. CREDIT: Elodie Camprasse.
The elephant seals primarily prey on lanternfish, which are bioluminescent — they naturally give off a glow. The glow helps the fish communicate with other members of their species; it also allows them to startle predators and to hide from carnivores lurking underneath by mimicking the light from above. [Bioluminescence: A Glow in the Dark Gallery]

Past research showed the vision of these seals is specialized to weak light, with peak sensitivity for the same blue light that lanternfish give off. Scientists who tagged southern elephant seals in the southern Indian Ocean were surprised to find these seals may track lanternfish by sight.

"Each year about 10 tags are deployed on seals in Kerguelen Islands, French territories in the southern Indian Ocean," Vacquié-Garcia said. "We leave for several months, living on an island swept by storms from the Southern Ocean where the seals come onshore twice per year. The experience is unique and very exciting."

In addition to the seals, "the seabird colonies are also very numerous — albatrosses, penguins," Vacquié-Garcia said. "This is one of the few places in the world where we are confronted with the wild world with such intensity. It is a real privilege."

The scientists anesthetized four female seals and glued electronics onto their heads. These devices included satellite tags that relayed temperature and other data, as well as sensors that monitored light and recorded the depth and lengths of dives.

"The initial topic of the study was absolutely not dedicated to bioluminescence," Vacquié-Garcia said. "The light sensor was originally aimed to see if there was a link between the depth of penetration of light from above and how productive a depth was," in terms of life in that layer.

Foraging with light
The researchers analyzed a total of 3,386 dives and deduced that seals found good areas to forage based on how fast they ascended from those areas and dove back to them.
Scientists anesthetized four female elephant seals from the southern Indian Ocean and glued electronics onto their heads. CREDIT: Elodie Camprasse.
Increased bioluminescence deep underwater, where there was no light from above, was linked with foraging. This suggests these glows help the seals forage more and find prey.

"We had confirmation that without really wanting to, we had recorded the events of bioluminescence along the dive tracks of seals," Vacquié-Garcia said.

Future research could aim to identify with certainty what bioluminescent species the seals encountered, and how bioluminescent events change around the seals as they swim.

The scientists detailed their findings online Aug. 29 in the journal PLoS ONE.

Would You Infect Yourself With Worms For Better Health?

ORIGINAL: FastCO

The death of important gut-dwelling parasites that we co-evolved with may be causing the rise in food allergies and other diseases. Now scientists are working on finding ways to have us and our worms live in harmony again.

Jim Lahey, founder of Sullivan Street Bakery in New York, fosters an obsession with microorganisms. Yeasts and bacteria give rise to his leavened sourdough breads--and he recently infected himself with intestinal worms to stave off a wheat sensitivity he attributes to working around flour dust. “These worms are meant to be in our bodies as part of human evolution."

Lahey may be taking the experiments further than most, but he is not alone in thinking that a modern, industrialized world may be making us sick because our good, clean standard of living is too easy on the body. Hygiene is a mixed blessing: Washing your hands, drinking clean water, and eating safe, refrigerated foods comes with vast reductions in childhood mortality. Yet, the hygiene hypothesis--an idea first put forward by epidemiologist David Strachan in 1989--suggests that chronic underexposure to germs and pathogens also corresponds with the rise of allergies and chronic inflammatory diseases.These worms are meant to be in our bodies as part of human evolution.

Joel Weinstock, a physician and a gastroenterology researcher at Tufts University, has been studying the therapeutic potential of gastro-intestinal worms called helminths for over a decade. He says that changes in our flora and fauna influence health and can make us more prone to diseases. “Think about the diseases that emerged in the 20th century: Food allergy was exceedingly rare. Now, it’s very common.”

Evolution is a long slow slog and our genes haven’t changed. What has changed: the loss of “protective factors,” the life forms that dwell in our homes, our soil, and our guts, including parasites called helminths. “Those organisms have very powerful influence and people always had them,” he says. “For the first time in our evolution, we had children grow up without them.”

When the immune system starts attacking our intestines with reckless abandon, the reaction can lead to inflammatory bowel diseases (IBD) like Crohn’s disease and colitis. Weinstock has found that intestinal worms act as powerful therapeutic agents. In one clinical study of 52 volunteers with colitis, he observed significant improvements in those treated with whipworm eggs compared to those treated with an inert placebo. Those organisms have very powerful influence and people always had them.

Weinstock says he fields several calls a day from all over the world requesting information about the promising treatment, but he cautions against prescribing helminths for everyone, especially since manufacturing and testing processes for a standardized immunotherapy are still underway. But he believes the practice will be a component of mainstream medicine within three years--and could “immunize” patients against inflammation in the gut.

There’s certain exposures that may be healthy for us rather than harmful,” he says. “Right now, it’s hard to know what to recommend because ‘going and playing in the mud’ might expose you to the right organisms or the wrong organisms. We can’t say what is appropriate hygiene. Eventually, though, we’ll have an agent that we may give to children like a vaccine.”


miércoles, 29 de agosto de 2012

Oldest mites in amber discovered

ORIGINAL: Science News
August 27th, 2012
230-million-year-old fossils push back date of resin-preserved arthropods

ANCIENT MITES The new mite speciesTriasacarus fedelei (top) and Ampezzoa triassica (bottom) were found in 230-million-year-old amber. The find pushes back the record of oldest arthropods preserved in amber by about 100 million years. A. Schmidt/University of Göttingen

Mites could give competitors on Survivor a run for their game-show money.

Two of the tiny creatures, trapped in fossilized tree resin, smash the record for ancient amber-preserved arthropods, a group of critters that includes beetles, butterflies, spiders and shrimp. At 230 million years old, the mite fossils are about 100 million years older than previous finds, and suggest that mites’ basic body blueprint may be built to outwit, outplay and outlast.

Dinosaurs have come and gone, but mites have hardly changed,” says David Grimaldi of the American Museum of Natural History in New York City. “Their body form is quite similar to what we see in gall mites today.”

CAPTURED IN TIME Amber droplets are remnants of resin that oozed out of an ancient conifer tree and hardened, trapping tiny animals inside. Scientists discovered new species of mites in 230-million-year-old droplets.S. Castelli/University of Padova

That similarity is somewhat surprising considering that the Earth was profoundly different 230 million years ago, when most plants were ferns, the Atlantic Ocean didn’t exist and pterosaurs cruised the skies. The Triassic-period mites, however, look just like their present-day relatives: They have segmented bodies, piercing mouthparts and legs bristling with “featherclaws,” Grimaldi and his colleagues report online August 27 in the Proceedings of the National Academy of Sciences.  

Mites seem to have made major adaptations, however, to their food supply. Unlike modern gall mites, which feast mostly on flowering plants (sometimes forming bumpy growths on the leaves), the Triassic ones chowed on a more primitive type of greenery: conifers. Grimaldi’s team discovered the two new species of mites, one Triasacarus fedelei and the other Ampezzoa triassica, smothered in droplets of amber from a now-extinct species of cone-bearing tree. The amber also held the remnants of a fly. 

The golden globules are about the size of a grain of rice. The creatures are visible only through a microscope as tiny flecks that mar the fossilized resin’s clarity. “You can see these little critters in all their lifelike glory — it’s really quite amazing,” says paleoentomologist Michael Engel of the University of Kansas in Lawrence.

Limestone and shale can also hold arthropod fossils, but amber allows researchers to take a more intimate look. “The detail preservation in these mites is leaps better than other Triassic arthropods,” Engel says. “Actually, leaps is an understatement. The difference in preservation is a massive chasm.”

The team picked through ancient sediments in the Dolomite Alps of northeastern Italy in search of resin dollops, then took two years to examine 70,000 amber droplets, shards and fragments. Only three housed arthropods. “With this discovery, we’re obviously all hot and ready to go back and screen through lots more,” Grimaldi says. Arthropods are the most diverse group of creatures on Earth, making up more than 50 percent of all known species. They’re one of the key lineages of life, says Engel. “Anything we can do to better understand what led to their successes and failures can tell us how they shaped the planet in the past and how they’re shaping the planet today,” he says. 

Modeling the Cell

ORIGINAL: The Scientist
By Jef Akst
July 23, 2012

The first full computer model of a single-celled organism mimics the bacterium’s behaviors and paves the way to more complete disease models.

Digital DNA, Art in Public Places,
Palo Alto, California FLICKR, 
WONDERLANE
Mycoplasma genitalium, a bacterium known to cause urethritis, made headlines in 2008 when J. Craig Venter and colleagues announced that they had manufactured and assembled the organism’s 600,000 base pair genome. Now, the microbe is in the news again—this time for becoming the first organism to be fully modeled by a computer program.

Bioengineering professor Markus Covert of Stanford University and colleagues scoured some 1,000 papers in the scientific literature to glean the information needed about the functions of M. genitalium proteins and genes to model how the bacterium behaves in the real world. In the end, they constructed a computer simulation that incorporates every known gene function. The team published its results last week (July 19) in Cell.

So far, it all works great,” Covert told The Chronicle of Higher Education. “We were able to recapitulate a lot of the behaviors of the cell.” Running hundreds of simulations, the researchers identified key factors involved in processes such as cell growth. They also were able to test the effects of knocking out individual genes—an exercise that proved “extremely predictive,” Covert said.

Past modeling studies have created programs that reflected certain functions of cells, such as the metabolism of E. coli, but this is the first to model an entire organism. But with only 460 genes, however, M. genitalium is a relatively simple. (By comparison, the metabolic E. coli model involved about 1,300 genes.) Still, the new model is an important first step.”He did this for the entire cell,” bioengineer Bernhard Palsson of the University of California at San Diego told The Chronicle. “So that’s the achievement here.”

Such models could help uncover mechanisms involved in cancers and other diseases, Covert added. “The simple fact is, there’s no way we are going to wrap our heads around cancer or any complex disease without a computer model, and so I see this as definitely a big start,” he told The Chronicle.

martes, 28 de agosto de 2012

El fascinante hallazgo geológico de Curiosity en Marte

ORIGINAL: BBC
Redacción BBC Mundo
Martes, 28 de agosto de 2012

Curiosity detectó una "discordancia" en las capas del Monte Sharp.
El explorador de Marte, Curiosity, está dedicado a un frenesí de actividad de multimedios, antes de su misión científica propiamente dicha.

Por lo pronto, envió la primera foto de su teleobjetivo de 100 milímetros, que ya detectó una intrigante "discordancia" geológica.

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La Nasa también dio a conocer una foto panorámica en colores del Monte Sharp, la meta definitiva del explorador.

Este lunes, el robot transmitió "la primera grabación de una voz en ser enviada a otro planeta", y el martes transmitirá una canción del artista will.i.am, como parte de un evento educativo.

Pero junto a estas manifestaciones, Curiosity -también conocido como el Laboratorio de Ciencia de Marte- ya está afinando sus instrumentos para una misión científica de un alcance sin precedentes en el planeta rojo.

La Nasa dijo que el explorador ya ha enviado más información de Marte que todos los anteriores vehículos combinados de la agencia.

Eventualmente rodará hasta la base del Monte Sharp, la montaña de 5.000 metros de altura en el centro del cráter Gale, en el que aterrizó hace poco más de tres semanas.

Herramientas de lujo
Por ahora está examinando las "marcas de la erosión" dejadas por la grúa propulsada por cohetes que descendió al explorador hasta la superficie del planeta, dando así una visión de lo que se encuentra justo debajo de él.

El explorador empleará ahora su albedo dinámico de neutrones o instrumento Dan, que dispara las partículas subatómicas en la superficie para examinar los niveles de hidrógeno y minerales con hidroxilo, que podrían dar indicios de una previa historia de Marte rica en agua.
Las fotos fueron tomadas el 23 de agosto con una cámara de 34 milímetros.
Otra herramienta de su arsenal, el espectrómetro ChemCam, que usa un láser para vaporizar rocas y luego examinar químicamente el vapor, también mirará las marcas de la erosión.

Y el Análisis de muestras en Marte o instrumento Sam, un paquete de tres herramientas de análisis, ya está encendido y se está probando en anticipación a su "olfateo" de la atmósfera marciana. Las pruebas incluyen el análisis de una muestra de aire de la Tierra que quedó adentro en el lanzamiento.

Pero lo que ya ha capturado el interés de los ingenieros de la Nasa es la llamada "discordancia" detectada en las primeras imágenes del Monte Sharp enviadas por el explorador.

El término se refiere una pieza evidentemente ausente en el registro geológico, donde una capa de sedimento que no se alinea geológica y perfectamente con la de encima.

Las imágenes desde la órbita indicaron que las colinas más bajas del Monte Sharp consistían en sedimentos planos ricos en minerales "hidratados", formados en presencia de agua, pero las capas encima parecían carecer de los minerales.

Ahora bien, el Mastcam del explorador -que brinda la nueva imagen panorámica en color- ha tomado una imagen de la brecha, que muestra sedimentos aparentemente depositados en un ángulo marcadamente diferente de aquellos debajo de ellos. Depósitos similares sobre la Tierra pueden surgir debido a actividad tectónica o volcánica.

Los puntos blancos marcan la línea entre dos diferentes estratos geológicos.
Desvío
Sin embargo, investigaciones posteriores tendrán que esperar un tiempo, mientras Curiosity hace un pequeño desvío.

La actividad de multimedios del explorador continuará mientras realiza un trayecto corto de 10 metros y se dedica el martes a tomar estereogramas: como nuestros ojos, combinando dos imágenes para lograr información acerca de profundidad y distancia.

A las 20:00 GMT, transmitirá una nueva canción de will.i.am, que pasará la televisión de la Nasa, como parte de una iniciativa para la educación primaria que hará uso de la tecnología de la agencia, incluido el explorador.

El lunes, el robot recibió y mandó de vuelta un mensaje grabado por el administrador de la Nasa, Charles Bolden, que decía: "El conocimiento que esperamos ganar de nuestra observación y análisis del cráter Gale nos enseñará mucho sobre la posibilidad de vida en Marte, así como las posibilidades del pasado y el futuro de nuestro propio planeta".

La próxima parada para el explorador será Glenelg, 400 metros al este, que parece ser la intersección de tres distintas regiones geológicas; cosechas potencialmente ricas para la serie de herramientas de Curiosity.

"Cuando finalmente lleguemos a Glenelg, deseamos estudiar el promontorio y dar una mirada a los contactos entre los tres terrenos", dijo a la BBC Joy Crisp, una científica que trabaja en la misión.

De ahí partirá hacia la base del Monte Sharp en un viaje que tomará varios meses.

Multiband Solar Cell

ORIGINAL: LBNL
Ene 28, 2011

It was recognized over thirty years ago that the introduction of states in a semiconductor band gap presents an alternative to multijunction designs for improving the power conversion efficiency of solar cells. The intermediate band acts as a “stepping stone,” allowing absorption of photons at three different energy levels, corresponding to the three different band gaps. In particular, low-energy photons are captured that would pass through a conventional solar cell (Fig. 1). Detailed theoretical calculations indicated that a single junction cell with a properly located band of intermediate states could achieve power conversion efficiencies up to 62% - i.e. higher than those for optimized double-junction tandem cells (Fig. 2). Even higher efficiencies of up to 71.7% were predicted for materials with two bands of intermediate states. 
Figure 1 A schematic of an intermediate band solar cell
Until very recently, practical realization of semiconductors with this multi-band structure had not been achieved. We have designed and synthesized a new class of semiconductor alloys with an intermediate band within the energy gap. The design of our material is based on the recently introduced band anticrossing (BAC) model of highly mismatched semiconductor alloys (HMAs). Group III-N-V alloys in which group V anions are partially replaced with N or group II-O-VI alloys in which column VI element is replaced with O are the well known examples of the HMAs. The electronic structure of the HMAs is determined by the interaction between localized states associated with N or O atoms and the extended states of the host semiconductor. As a result the conduction band splits into two subbands (E- and E+) with non-parabolic dispersion relations.
In most instances, e.g. N in GaAs or O in CdTe, the localized states are located within the conduction band and consequently a relatively wide lower subband is formed. A narrow band can be formed only if the localized states occur well below the conduction band edge. 

Figure 2 Comparison of the maximum power conversion efficiency of an intermediate band solar cell, a single gap solar cell, and a double junction tandem cell. The higher gap values for the tandem cell and the IBSC are indicated on the plot. (after Luque et. al. PRL, 78, 5014(1997)) 
In this case the E- subband states are of highly localized character and the E+subband states become more extended. This situation occurs for O in ZnTe, MnTe, MgTe. Figure 3 illustrates the formation of a narrow intermediate band by the incorporation of O into ZnTe. In addition to the O content, Mn alloying can also be used to adjust the energy level positions. Thus, band locations corresponding to those that are optimal for a multiband solar cell can be produced in ZnTeO and ZnMnTeO. With multiple band gaps that fall within the solar energy spectrum, Zn1-xMnxOyTe1-y is well suited for the proposed high efficiency intermediate band solar cells (IBSCs). This new II-VI oxide multi-band semiconductor was synthesized using the combination of oxygen ion implantation and pulsed laser melting. This highly non-equilibrium technique allowed for the synthesis of ZnMnOTe alloys with up to 3% of Te replaced with O atoms. Fig. 4 shows PR spectra from a Zn0.88Mn0.12Te substrate and two Zn0.88Mn0.12Te samples implanted with 3.3% of O followed by PLM with laser energy fluence of 0.15 and 0.3 J/cm2. Two optical transitions occurring at energies distinctly different from the fundamental band gap transition EM (=2.31 eV) of the Zn0.88Mn0.12Te matrix can be clearly observed at ~1.8 and 2.6 eV from the samples after PLM.

Fig. 3. Band anticrossing and formation of an intermediate band in Zn1-yMnyTe1-xOx.
Fig. 4. Photomodulated reflectance (PR) spectra obtained from Zn0.88Mn0.12Te samples as-grown and implanted with 3.3% O+followed by PLM with energy fluence of 0.15 and 0.3 J/cm2

These two optical transitions can be attributed to transitions from the valence band to the two conduction subbands, E+ (~2.6 eV) and E- (~1.8 eV) formed as a result of the hybridization of the localized O states and the extended conduction band states of ZnMnTe.

Our results from optical transitions clearly demonstrate that three types of optical transitions are possible in this band structure; (1) the transitions from the valence band to the E+subband with the absorption edge at EV+=E+(k=0)-EV(k=0)=2.56 eV, (2) transitions from the valence band to E- subband with the edge at EV-=E-(k=0)-EV(k=0)=1.83 eV and (3) the low energy transitions from E- to E+ with the absorption edge atE_+=E+(k=0)-E_(k=0)=0.73 eV. The three absorption edges span much of the solar spectrum, demonstrating that these alloys are good candidates for the multi-band semiconductors envisioned for high efficiency photovoltaic devices.

Detailed balance calculations of the power conversion efficiency for a intermediate band solar cell based on this material is shown in Fig. 5. Even for this non-optimal band gap configuration we calculate a power conversion efficiency of 45%, which is higher than the ideal efficiency of any solar cell based on a single junction in a single-gap semiconductor and is comparable to the efficiency of double-junction cells.

The potential technological importance of the multiband semiconductors raises the question if they can also be realized in group III-Nx-V1-x HMAs as well. In most III-V compounds the localized N level lies above the conduction band edge. An exception is the GaAs1-yPy alloy system in which N-level falls below the conduction band edge for y>0.3. Consequently the anticrossing interaction of the N states with the extended conduction band states in these GaAsP alloys is expected to result in the formation of a narrow band of intermediate states. Recently we have also synthesized GaNxAs1-yPy with y=0 to 0.4 using N+-implantation followed by PLM and RTA techniques. With an implanted N concentration of 2%, the N concentration incorporated in the As sublattice amounts to about 1% and 0.3% for films with y≤0.12 and y>0.12, respectively. GaNxAs1-yPy with y>0.2 clearly shows strong optical transitions corresponding to both the lower (E-) and upper (E+) conduction subbands. GaNxAs1-yPy alloys with y>0.3 have a three band structure making them suitable for testing the theoretical predictions of the highly-efficient intermediate band solar cell concept. Theoretical ideal efficiency for IBSC using the GaN0.02As0.58P0.4 is calculated to be >55%.
Fig. 5: The calculated power conversion efficiency for a solar cell fabricated from a Zn0.88Mn0.12OxTe1-x alloy as a function of O content. The solid line is an empirical polynomial fit of the calculated data. 
Selected References:
  • A. Luque, A. Marti., Phys. Rev. Lett., 78, 5014 (1997).
  • K. M. Yu, W. Walukiewicz, J. Wu, W. Shan, and J. W. Beeman, M. A. Scarpulla, O. D. Dubon, and P. Becla, “Diluted II-VI Oxide Semiconductors with Multiple Band Gaps,” Phys. Rev. Lett. 91, 246203 (2003).
  • W. Shan, K. M. Yu, W. Walukiewicz, J. Wu, J. W. Beeman, and J.W. Ager III, M.A. Scarpulla, O.D. Dubon, and E. E. Haller, “Effects of Pressure on the Band Structure of Highly Mismatched Zn1-yMnyOxTe1-x Alloy,” Appl. Phys. Lett. 84, 924 (2004).
  • K. M. Yu, W. Walukiewicz, J.W. Ager III, D. Bour, R. Farshchi, O. D. Dubon, S. X. Li, I. D. Sharp, and E. E. Haller, “Multiband GaNAsP Quaternary Alloys,” Appl. Phys. Lett. 88, 092110 (2006).
  • K. M. Yu, W. Walukiewicz, M. A. Scarpulla, O. D. Dubon, W. Shan, J. Wu, J. W. Beeman, and P. Becla, “Synthesis and Properties of Highly Mismatched II-O-VI Alloys,” invited paper, pres. at E-MRS 2004 SPRING MEETING, Symposium M: Dilute nitride and related mismatched semiconductor alloys, Palais de la Musique et des Congres, Strasbourg, France, May 24-28, 2004. IEE Proceedings-Optoelectronics 151 (5): 452-459, Oct. 2004 (IEE-Inst. Elec. Emg., Michael Faraday House, Six Hills Way, Stevenage, Hertford, SG1 2AY, ENGLAND).

ORIGINAL: Ecoosfera

Nuevos paneles solares capturan más energía de los rayos solares no visibles


En un invento que podría revolucionar a corto plazo la generación de energía alternativa a través del sol, un grupo de investigadores del Lawrence Berkeley National Laboratory anunció la creación de páneles solares que cargan energía aún en la oscuridad. La relevancia de este invento resulta evidente ya que permitiría eficientar radicalmente la creación de energía aprovechable a través del sol.

Actualmente uno de los grandes problemas de la energía solar es que depende de las horas de sol a las que esten expuestas los páneles. Esto quiere decir que en latitudes del norte, donde existen temporadas en las que el sol escacea, a veces resulta poco rentable la instalación de una infraestructura. Lo mismo sucede en días nublados y en promedio la mitad del tiempo no estarás produciendo energía por medio de esta vía.

Pero estas nuevas celdas solares permitirán la generación de energía aun durante la noche ya que están diseñadas para aprovechar casi la totalidad del espectro del sol, incluso cuando este no es visible en un lugar durante la noche. Pero el otro aspecto fundamental para considerar esta invención como algo energéticamente esperanzador es el hecho de que su costo será bastante accesible lo cual permitirá que su aprovechamiento se popularize y en este sentido es un real candidato a mejorar las expectativas frente a las energías alternativas con miras a emanciparnos de nuestra histórica dependencia de los hidrocarburos