sábado, 30 de junio de 2012

Programmable DNA Scissors Found for Bacterial Immune System

ORIGINAL: ScienceDaily
Programmable DNA scissors: A double-RNA structure in the bacterial immune system has been discovered that directs Cas9 protein to cleave and destroy invading DNA at specific nucleotide sequences. This same dual RNA structure should be programmable for genome editing. (Credit: Image by H. Adam Steinberg, artforscience.com)
ScienceDaily (June 28, 2012) — Genetic engineers and genomics researchers should welcome the news from the Lawrence Berkeley National Laboratory (Berkeley Lab) where an international team of scientists has discovered a new and possibly more effective means of editing genomes. This discovery holds potentially big implications for advanced biofuels and therapeutic drugs, as genetically modified microorganisms, such as bacteria and fungi, are expected to play a key role in the green chemistry production of these and other valuable chemical products.

Jennifer Doudna, a biochemist with Berkeley Lab's Physical Biosciences Division and professor at the University of California (UC) Berkeley, helped lead the team that identified a double-RNA structure responsible for directing a bacterial protein to cleave foreign DNA at specific nucleotide sequences. Furthermore, the research team found that it is possible to program the protein with a single RNA to enable cleavage of essentially any DNA sequence.

"We've discovered the mechanism behind the RNA-guided cleavage of double-stranded DNA that is central to the bacterial acquired immunity system," says Doudna, who holds appointments with UC Berkeley's Department of Molecular and Cell Biology and Department of Chemistry, and is an investigator with the Howard Hughes Medical Institute (HHMI). "Our results could provide genetic engineers with a new and promising alternative to artificial enzymes for gene targeting and genome editing in bacteria and other cell types."

Doudna is one of two corresponding authors of a paper in the journal Science describing this work titled "A programmable dual RNA-guided DNA endonuclease in adaptive bacterial immunity." The second corresponding author is Emmanuelle Charpentier of the Laboratory for Molecular Infection Medicine at Sweden's Umeå University. Other co-authors of the paper were Martin Jinek, Krzysztof Chylinski, Ines Fonfara and Michael Hauer.

Bacterial and archaeon microbes face a never-ending onslaught from viruses and invading circles of nucleic acid known as plasmids. To survive, the microbes deploy an adaptive-type nucleic acid-based immune system that revolves around a genetic element known as CRISPR, which stands for Clustered Regularly Interspaced Short Palindromic Repeats. Through the combination of CRISPRs and associated endonucleases, called CRISPR-associated -- "Cas" -- proteins, bacteria and archaeons are able to utilize small customized crRNA molecules (for CRISPR-derived RNA) to target and destroy the DNA of invading viruses and plasmids.

There are three distinct types of CRISPR/Cas immunity systems. Doudna and her colleagues studied the Type II system which relies exclusively upon one family of endonucleases for the targeting and cleaving of foreign DNA, the Cas9 proteins.

"For the Type II CRISPR/Cas system, we found that crRNA connects via base-pairs with a trans-activating RNA (tracrRNA), to form a two-RNA structure," Doudna says. "These dual RNA molecules (tracrRNA:crRNA) direct Cas9 proteins to introduce double-stranded DNA breaks at specific sites targeted by the crRNA-guide sequence."

Doudna and her colleagues demonstrated that the dual tracrRNA:crRNA molecules can be engineered as a single RNA chimera for site-specific DNA cleavage, opening the door to RNA-programmable genome editing.

"Cas9 binds to the tracrRNA:crRNA complex which in turn directs it to a specific DNA sequence through base-pairing between the crRNA and the target DNA," Doudna says. "Microbes use this elegant mechanism to cleave and destroy viruses and plasmids, but for genome editing, the system could be used to introduce targeted DNA changes into the genome.

Doudna notes that the "beauty of CRISPR loci" is that they can be moved around on plasmids.

"It is well-established that CRISPR systems can be transplanted into heterologous bacterial strains," she says. "Also, there is evidence to suggest that CRISPR loci are horizontally transferred in nature."

Doudna and her colleagues are now in the process of gathering more details on how the RNA-guided cleavage reaction works and testing whether the system will work in eukaryotic organisms including fungi, worms, plants and human cells.

"Although we've not yet demonstrated genome editing, given the mechanism we describe it is now a very real possibility," Doudna says.

This work was funded primarily by the Howard Hughes Medical Institute, the Austrian Science Fund and the Swedish Research Council.

Story Source:
The above story is reprinted from materials provided by DOE/Lawrence Berkeley National Laboratory .

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
M. Jinek, K. Chylinski, I. Fonfara, M. Hauer, J. A. Doudna, E. Charpentier. A Programmable Dual-RNA-Guided DNA Endonuclease in Adaptive Bacterial Immunity.Science, 2012; DOI: 10.1126/science.1225829

Exxon's CEO is Right, We Will Adapt to Climate Change

¿Es la adaptabilidad infinita? o ¿Este cambio climático antropocéntrico podrá causar la extinción humana? Habrá que preguntarle a Exxon. 
Vanessa Restrepo Schild

ORIGINAL: TreeHugger
I'm a day late to this image above and the social media outrage around it, but I've been thinking, and unfortunately ExxonMobil's CEO is right. That's the unfashionable thing to say in green circles, but he is right.

Humanity has spent its time on this planet adapting. Both adapting the world we inhabit to meet our needs, on various timescales and over various areas of the globe, as well as adapting to the local conditions under which we live.

And, we will adapt to climate change.

But nevertheless, the statement is obfuscation of the highest order; it is literally true but contextually entirely false. And it is there where it's deep insidiousness resides.

How many humans the planet can support in a world that is 2°C, 3°C, 4-6°C warmer on average—with all the ecosystem, biodiversity, agricultural changes that brings—is a very much open question. The odds are solidly in favor of far less than it now does, just because of climate change, ignoring resource overconsumption and population growth.

Which is all to say, that while humanity will adapt to a climate changed world is true, there is no doubt that climate change will create, in comparison to today, let alone a pre-industrial, lower population world, a world that is less bountiful, prone to more extremes of temperature and weather in many places, less fecund—and since we're talking about human adaptation, more difficult to live in and less conducive to human civilization.

The thing in Rex Tillerson's statement that is so mind-numbing egregious to me is the apparent full public blindness to the fact that this is the world that we are creating, that humanity is creating largely because of the products that Tillerson's company produces. It's made worse by the fact that Exxon has historically, and currently, funded countless organizations that attempt to sow doubt about this fact, apparently solely to enrich themselves.

Evidence of life on Mars could come from Martian moon Phobos

ScienceDaily (June 29, 2012) — A mission to a Martian moon could return with alien life, according to experts at Purdue University, but don't expect the invasion scenario presented by summer blockbusters like "Men in Black 3" or "Prometheus."

"We are talking little green microbes, not little green men," said Jay Melosh, a distinguished professor of earth, atmospheric and planetary sciences and physics and aerospace engineering at Purdue. "A sample from the moon Phobos, which is much easier to reach than the Red Planet itself, would almost surely contain Martian material blasted off from large asteroid impacts. If life on Mars exists or existed within the last 10 million years, a mission to Phobos could yield our first evidence of life beyond Earth."

Melosh led a team chosen by NASA's Planetary Protection Office to evaluate if a sample from Phobos could contain enough recent material from Mars to include viable Martian organisms. The study was commissioned to prepare for the failed 2011 Russian Phobos-Grunt mission, but there is continued international interest in a Phobos mission, he said. It will likely be a recurring topic as NASA reformulates its Mars Exploration Program.

A Phobos mission was discussed at NASA's Concepts and Approaches for Mars Exploration workshop and a report issued June 26 stated that the Martian moons are "important destinations that may provide much of the value of human surface exploration at reduced cost and risk."

Melosh collaborated with Kathleen Howell, the Hsu Lo Professor of Aeronautical and Astronautical Engineering, and graduate students Loic Chappaz and Mar Vaquero on the project.

The researchers combined their expertise in impact cratering and orbital mechanics to determine how much material was displaced by particular asteroid impacts and whether individual particles would land on Phobos, the closer of the two Martian moons.

The team concluded that a 200-gram sample scooped from the surface of Phobos could contain, on average, about one-tenth of a milligram of Mars surface material launched in the past 10 million years and 50 billion individual particles from Mars. The same sample could contain as much as 50 milligrams of Mars surface material from the past 3.5 billion years.

"The time frames are important because it is thought that after 10 million years of exposure to the high levels of radiation on Phobos, any biologically active material would be destroyed," Howell said. "Of course older Martian material would still be rich with information, but there would be much less concern about bringing a viable organism back to Earth and necessary quarantine measures."

When an asteroid hits the surface of a planet it ejects a cone-shaped spray of surface material, similar to the splash created when someone does a cannonball into a swimming pool. These massive impacts pulverize the surface material and scatter high-speed fragments. The team calculated that the bulk of the fragments from such a blast on Mars would be particles about one-thousandth of a millimeter in diameter, or 100 times smaller than a grain of sand, but similar in size to terrestrial bacteria.

The team followed the possible paths the tiny particles could take as they were hurtled from the planet's surface through space, examining possible speeds, angles of departure and orbital forces. The team plotted more than 10 million trajectories and evaluated which would intercept Phobos and where they might land on the moon during its eight-hour orbit around Mars.

The probability of a particle landing on Phobos depends primarily on the power of the blast that launched it from the surface, Chappaz said.

"It is estimated that during the past 10 million years there have been at least four large impact events powerful enough to launch material into space, and we focused on several large craters as possible points of origin," he said. "It turns out that no matter where Phobos is in its orbit, it would have captured material from these powerful impact events."

After the team submitted its report, scientists identified a large, nearly 60-kilometers-in-diameter crater on Mars. The crater, named Mojave, is estimated to be less than 5 million years old, and its existence suggests that there would be an even greater amount of Martian material on Phobos that could contain viable organisms than estimated, Melosh said.

"It is not outside the realm of possibility that a sample could contain a dormant organism that might wake up when exposed to more favorable conditions on Earth," he said. "I participated in a study that found that living microbes can survive launch from impacts on rock, and other studies have shown some microscopic organisms can tolerate a lot of cosmic radiation."

This possibility has been a consideration for some time, and Michael Crichton's "The Andromeda Strain" brought it to public consciousness in 1969. However the movie scenario of a fatal contamination is unlikely, Melosh said.

"Approximately one ton of Martian material lands on Earth every year, " he said. "There is a lot more swapping back and forth of material within our solar system than people realize. In fact, we may owe our existence to life on Mars."

Howell also is optimistic that life is not unique to Earth.

"It's difficult to believe there hasn't been life somewhere out there in the vast expanse of space," Howell said. "The question is if the timeline overlaps with ours enough for us to recognize it. Even if we found no evidence of life in a sample from Phobos, it would not be a definitive answer to the question of whether or not there was life on Mars. There still may have been life that existed too long ago for us to detect it."

Melosh recently presented the team's findings at a joint NASA and European Space Agency meeting in Austria, and Chappaz will present the data at a meeting on July 14 in Mysore, India.

Richard Feynman - The Pleasure Of Finding Things Out

The Pleasure of Finding Things Out was filmed in 1981 and will delight and inspire anyone who would like to share something of the joys of scientific discovery. Feynman is a master storyteller, and his tales -- about childhood, Los Alamos, or how he won a Nobel Prize -- are a vivid and entertaining insight into the mind of a great scientist at work and play.

In this candid interview Feynman touches on a wide array of topics from the beauty of nature to particle physics. He explains things that are hard to grasp in layman's terms much like Carl Sagan did in the cosmos series. His explanation of the scientific method covers what we know, why we know it and most importantly, what we don't know and the pleasure of figuring it out.

Professor Sir Harry Kroto, Nobel Prize for Chemistry said "The 1981 Feynman Horizon is the best science program I have ever seen. This is not just my opinion -- it is also the opinion of many of the best scientists that I know who have seen the program... It should be mandatory viewing for all students whether they be science or arts students."

Discovery: Earth's Oldest Crater Is Largest Too

Douglas Main, OurAmazingPlanet Staff Writer
Date: 29 June 2012 Time: 04:42 PM ET

An artistic interpretation of how a large meteorite impact might have looked. The crater formed in modern-day Greenland may be the oldest and largest yet discovered on Earth. CREDIT: Carsten Egestal Thuesen, GEUS 
A study of Greenland's rocks may have turned up something unexpected: the oldest and largest meteorite crater ever found on Earth.

Researchers think the crater was formed 3 billion years ago, making it the oldest ever found, said Danish researcher Adam Garde. The impact crater currently measures about 62 miles (100 kilometers) from one side to another. But before it eroded, it was likely more than 310 miles (500 km) wide, which would make it the biggest on Earth, Garde told OurAmazingPlanet.

The team has calculated it was caused by a meteorite 19 miles (30 km) wide, which, if it hit Earth today, would wipe out all higher life.

Mystery feature

In the 3 billion years since impact, the land has been eroded down to about 16 miles (25 km) below the original surface. But the effects of the intense shock wave and heat penetrated deep into the Earth, and remain visible today, said Garde, a researcher at the Geological Survey of Denmark and Greenland. [ Meteor Mania: How Well Do You Know 'Shooting Stars'? ]

Garde had been conducting research on Greenland's geology and noticed several strange features that didn't make sense. One day in September 2009, he came up with the extreme explanation of an impact from a meteorite. His team collected samples over the years and published the results in the July issue of the journal Earth and Planetary Science Letters. He's now "100 percent positive" it's a crater, for several reasons, he said.

For one, he found widespread crushed rocks in a circular shape that seemed to be caused by the shock waves of a massive impact.
Second, there are deposits of a melted mineral called K-feldspar (or potassium-feldspar) that could have been liquefied only at extremely high heat, like that caused by an meteorite's crash-landing .
There's also widespread evidence of weathering by hot water, which he thinks was caused by the ocean rushing into the crater after it struck the area. The area may have been covered by a shallow ocean at the time, but even if it wasn't, it doesn't matter, Garde said. "The crater from a meteorite that big would have caused the sea to rush in," he said.

Mining for minerals

The black circle on map shows the location of the meteorite impact near the town of Maniitsoq in Greenland. CREDIT: Geological Survey of Denmark and Greenland
John Spray, a meteorite expert at the University of New Brunswick, who wasn't involved in the research, said he thinks it's probably a meteor crater, but points out that it hasn't been proved, and may not be for some time. "It's very interesting and it's good science," he said. "But we don't really know how to recognize very old impact craters, because they are typically so highly modified."

That's because Earth is alive and constantly changing due processes such as erosion, precipitation and plate tectonics. At one time Earth likely had as many craters as the moon, which is essentially geologically dead. But these have mostly been wiped away, destroyed by erosion and the like.

Only around 180 impact craters have ever been discovered on Earth, and nearly one-third of them contain significant minerals deposits such as precious metals. The Canadian mining company, North American Nickel, is exploring the region where the potentially newfound crater is for nickel and other mineral deposits, company geologist John Roozendaal said. They are conducting airborne surveys and will soon do more mapping, small-scale sampling and drilling to see if they can find an area that could be economical to mine.

These impacts are of interest to mining companies not because of the large meteorites themselves — they typically vaporize — but because of the effect upon the Earth's surface. The impact heats rocks so much that metals can melt and then collect toward the bottom of the crater. Craters can also be important sources of oil and gas; the crushed, permeable rocks can act like a sponge, absorbing hydrocarbons.

Before this discovery, the oldest crater was thought to be the Vredefort crater in South Africa, estimated to be 2 billion years old. At 186 miles (300 km) wide, it's also the largest crater that remains visible. Scientists expect that there were many more craters formed around 3-4 billion years ago when Earth lacked a protective atmosphere.

Garde said the most interesting thing about the experience was finding an alternate explanation for something outside of his training. "I had a problem I couldn't solve in a region I knew very well," he said. "A meteor impact was the idea that made everything fall into place — It's not something I was looking for."

This article was provided by OurAmazingPlanet , a sister site of SPACE.com. Reach Douglas Main at dmain@techmedianetwork.com . Follow him on Twitter @Douglas_Main . Follow OurAmazingPlanet on Twitter @OAPlanet . We're also on Facebook and Google+ .

La solución de Islandia para salir de la crisis: ni un céntimo para los bancos

eva pastrana @ABC_es / madrid
Día 07/06/2012 - 05.14h

El país que no dio dinero público a la banca y llevó a políticos y banqueros a los tribunales ya está saliendo de la crisis

marius montan 

Islandia, 2007: país pequeño, poco poblado y con alto grado de bienestar social. Cuatro pequeños bancos operaban en el interior del país. Poco a poco se fue permitiendo privatizar ciertos recursos, se facilitó la especulación bancaria. Se abusó de la vivienda como recurso de inversión, llegó el boom inmobiliario y con él, la concesión de créditos sin límite. En España ya hemos visto la película, pero en esta ocasión el final cambia.

Como ocurrió con nuestro país, un par de años después Islandia se colapsó. En 2008, fueron nacionalizados los tres mayores bancos y su deuda pública empezó a multiplicarse. Un año después, el Parlamento acordaba devolver la deuda a Gran Bretaña y Holanda, sus principales acreedores bancarios. Cada familia islandesa debía pagar 3.500 durante 15 años al 5,5 % de interés. Aumentaron las protestas sociales y se convocó un referéndum en el que se decidió rebajar el interés al 3% y aumentar el periodo de pago a 37 años. 

Finalmente, Islandia tuvo que pedir un rescate internacional del FMI que le obligó a acometer importantes ajustes económicos. Pero, ahí empieza la diferencia: el Gobierno islandés no desembolsó ni una sola corona de los contribuyentes en los bancos. Los dejó quebrar

En octubre de 2008, Islandia dejó morir a tres grandes bancos —el Kaupthing, el Landsbanki Íslands y el Glitnir—. Renegoció la deuda con los acreedores (en su mayor parte de Alemania, Reino Unido y Holanda) y permitió que tomaran el control de las nuevas entidades. No obstante, se calcula que los tenedores de la deuda (casi todos extranjeros) sufrieron una quita del 70%. 

Islandia no es España
Pese a las semejanzas en el discurrir de los acontecimientos, Islandia parte de un punto muy distinto. En el país escandinavo, para empezar, no circulan euros y eso les permite devaluar su moneda temporalmente, para ser más competitivos. En segundo lugar, los acreedores de la inmensa deuda de sus bancos, no eran los islandeses, sino alemanes, británicos y holandeses. Eso puede explicar que dejar morir a la banca, sea una opción para ellos, pero no para España.

Sin embargo, hay otro tipo de medidas que Islandia tomó. Los tribunales escandinavos, por ejemplo, juzgaron si el ex primer ministro Geir Haarde era «parte responsable en la crisis financiera». Se trata, por el momento, del único proceso judicial abierto en el mundo contra un político por su presunta implicación en una crisis económica.

El ex primer ministro negó todos los cargos. «Ninguno de nosotros estimaba que había algo mal en el sistema bancario», se defendió, al tiempo que añadía que no había ningún signo «claro» de que fuera a producirse ese «crack». Finalmente Haarde fue exculpado de tres de los cuatro cargos que se le imputaban aunque se le condenó por violar la ley de responsabilidad de los ministros.

También sentará en el banquillo de los acusados la cúpula directiva del banco islandés Kaupthing Bank. El presidente y el consejero delegado de la entidad, fueron acusados junto a otros de fraude y manipulación por la Fiscalía Especial de Islandia, en el marco de sus investigaciones sobre el colapso de la banca islandesa en 2008.

Brotes verdes
A Islandia aún le quedan asuntos por resolver, pero está en el camino de conseguirlo. Su deuda pública sigue suponiendo el 100% del PIB y tiene una importante deuda privada, la inflación no está del todo estable y, aunque pagó anticipadamente de 339, 2 millones al FMI, aún le queda parte del préstamo por devolver.

El mismo órgano acaba de publicar su última revisión sobre el estado de Islandia y las previsiones dicen que este año su economía crecerá un 2,4%, con un consumo privado tirando al 3% y compensando la caída de la inversión pública fruto de las medidas de austeridad.

En la estepa islandesa ya se ven brotes verdes. Los islandeses han tirado el libro de estilo de las crisis económicas por la ventana y, por lo que parece, les está saliendo bien.

Colombia: 45% de vehículos a gas natural "rajados" en emisión de gases

El estudio sobre emisiones vehiculares fue realizado por el Banco Mundial y la UN. Fotos: Unimedios. 

Bogotá D. C., Jun. 29 de 2012 - Agencia de Noticias UN- Un estudio realizado por el Banco Mundial y la UN, arroja esta alarmante cifra y determina que no se están realizando las mediciones con la tecnología adecuada.

Los centros de diagnóstico automotor (encargados de emitir los Certificados de Revisión Técnico Mecánica) y las autoridades ambientales están midiendo con equipos que no están autorizados, regulados y verificados”, explicó Helmer Acevedo, profesor del Departamento de Ingeniería Mecánica y Mecatrónica de la UN e integrante del equipo que realizó investigación.

Para superar la situación, el estudio Evaluation of methods and equipment to measure vehicular emissions through static testing and determination of maximum permissible limits for mobile sources, recomienda, entre otras medidas, “crear un centro de medición de emisiones a cargo del Gobierno colombiano cuya función sea, entre otras, ejercer el cumplimiento de normas ambientales de vehículos”.

En cuanto a la opacidad (cantidad de humo negro) que están emitiendo los vehículos de servicio público y carga, la investigación muestra que los niveles contaminantes siguen siendo altos. “Existe una gran informalidad. La mayoría de estos automotores tienen tecnología obsoleta. Además, tienen serios problemas en el tema de mantenimiento”, dijo el ingeniero Acevedo.

De hecho, agregó el investigador, “Medellín tiene niveles de emisión de humo negro más bajos, si se compara con Cali o Barranquilla. La razón es que el mantenimiento de los vehículos es muchísimo mejor en la capital de Antioquia que en las otras dos ciudades.

La investigación, que tomó datos en Barranquilla, Cali, Medellín y Bucaramanga, será uno de los insumos que utilizará el Ministerio de Ambiente y Desarrollo Sostenible en las mesas de trabajo que se reunirán para diseñar normas que puedan subsanar los problemas encontrados. Un tema importante, por ejemplo, serán los nuevos límites de opacidad que regirán en Colombia a partir del año entrante.

El estudio, con una duración de siete meses, tenía tres grandes objetivos:

  1. el primero, adelantar una revisión bibliográfica sobre cuáles son las nuevas tendencias mundiales en la medición de emisiones para vehículos convertidos a gas natural y que funcionan con biocombustibles. “Hicimos una revisión bibliográfica y determinamos cuáles eran los mejores equipos y cómo estaba nuestra normatividad nacional en el contexto internacional”, dijo Acevedo.
  2. En segundo lugar, revisar cómo se está haciendo la tarea de expedir los certificados de emisiones de los vehículos. 
  3. Y, finalmente, efectuar una medición de 1.500 vehículos de diésel o ACPM en todo el país. 


N° 678


viernes, 29 de junio de 2012

Four Concepts For The Future That Could Create A More Sustainable World


In the next 15 years, the course of human society will be drastically altered by new technologies that we can’t even dream of. But, with enough planning now, we can push the development of those technologies toward those that make life better. These four ideas will help us get there.

Earlier this year, Sony teamed up with the  Forum Of The Future  to brainstorm four scenarios of what life will be like in 2025. Among them:
  • a treadmill of "hyperinnovation" and declining carbon emissions
  • a scenario of damaging climate change and reactive technologies (like solar paint), 
  • a scenario where sustainability and strong community ties are emphasized, and 
  • a world where the sharing economy has taken off on a global scale.
Now Sony and a handful of partners have come up with four concepts --
  • a platform, 
  • a product, 
  • a place, and 
  • a philosophy--
that could exist within and take advantage of these visions of the future 15 years from now.

In the future, it’s possible that nearly everything will have an IP address--your clothes, your plants, and your refrigerator will all freely send and receive data. The proposed Internet of Things Academy will teach people to use the hardware and software behind this connected world, allowing them to do everything from creating experimental economic models to public health monitoring initiatives. 

The concept of an Internet of Things--a system where the Internet is connected the physical world around us--has been around since the 1990s. We’re already seeing faint signals of its existence. In fact, a project that Co.Exist covered just the other day--the crowd-controlled ArduSat satellite --is a perfect example of what we could see more of in the future.

This cloud-connected, modular device will stay with users for a lifetime, "generating a similar sort of affection and sense of personal connection as a favorite watch," according to Sony’s brief. The device can be upgraded to include motion sensors, projectors, energy generation modules, and more--all generated by local 3-D printing to minimize environmental impact. 

The device is durable enough that it ages well and so customizable that nearly everyone could fit it with a design they like. It’s the dream antidote to today’s throwaway electronics cycle, where devices are constantly tossed for the newest upgrade.

The world is on track to have 75% of all humanity living in cities by 2050. What happens to the other 25%? Sony envisions the HyperVillage--a completely self-reliant but globally connected community "underpinned by the highest spec software and hardware." These HyperVillages will use technology to monitor local resources (water, fisheries, etc.) and to share "maker" knowledge with the larger world. All power is generated from community-owned renewable energy hubs, and immersive technology allows rural denizens to virtually travel to urban spaces for big events.

We’re already seeing a resurgence in "maker" culture--just visit your local Maker Faire to see how popular it has become--and projects like Alchematter (a Wikipedia for people who make things) are making it increasingly easy for people to become self-reliant. At the same time, local, independent economies are taking off, with some neighborhoods even creating their own currencies .

The Shift is more of a question than anything else. Sony asks, "Is it time to re-focus society’s relationship with technology so that it genuinely meets human needs?" Digital technology has changed the way we live, but there’s still a long way to go for it to truly revolutionize our personal well-being and connection with nature (an example of the latter is Urban Edibles , a digital database of wild food sources in Portland, Oregon). Instead, we often allow these technologies to waste our time and distract us (the average user spends 2.5 hours on email everyday), leaving little downtime to actually process what we experience.

The answer to Sony’s question is, of course, a resounding yes.

"Leap Second" to Be Added to the Weekend


Brian Handwerk
June 29, 2012

World timekeepers are giving you a (very) little more downtime Saturday.

The Shepherd 24-hour gate clock at the Royal Observatory in Greenwich, England.. Photograph by Eric Nathan, Alamy
Blink and you'll miss it, but this weekend's going to be a little longer than most. Just after 7:59:59 p.m. ET—23:59:59 coordinated universal time—a "leap second" will be tacked on to the world's atomic timepieces.

The chronological change spotlights some of the quirks of an increasingly critical task—keeping the world's clocks perfectly synced.

Coordinated universal time (UTC) is an atomic time scale derived from a variation of the metallic element cesium's atom. This truly atomic "clock" ticks with microwave light about nine billion times each second, allowing us to slice and dice time with extreme precision.

The official UTC time is set by the Paris-based International Bureau of Weights and Measures, which gathers contributions from labs in some 50 nations and computes an internationally agreed-on average.

Why a Leap Second?

This year's leap second—the 26th to be added to UTC since 1972—exists because time was traditionally based on a full rotation of the Earth and was related to heavenly bodies, which defined the length of the day.

This rotational time, called UT1, divides the day into 86,400 seconds.

But the atomic era demanded more exact timekeeping, and the world began doing business by UTC in 1972.

The two time scales, though, aren't quite in sync, because Earth spins a bit slower each year due to tides and internal processes that create a gap between the two scales.

The International Earth Rotation and Reference Systems Service monitors this difference and periodically inserts a leap second to keep the two in tandem.

Leap Second Pains
The difference between atomic and rotational time is tiny—only an hour or so every thousand years.

But the leap second causes a host of timekeeping issues, because no clock can accommodate an extra second. Instead, clocks are traditionally stopped at 23:59:59 for one second—but life goes on, and gets in the way.

"It might seem stupid to say that you have a difference of only one second," Elisa Felicitas Arias of the International Bureau of Weights and Measures told National Geographic News in 2008.

"But for the stock exchange, one second is important. For an airport, one second is important. For global navigation satellite systems, the difference of a second is unacceptable."

Navigation systems work by measuring the time it takes a signal to travel between a known satellite location and a receiver. Such systems require extreme precision on the level of nanoseconds, or billionths of a second.

"In one billionth of a second, light travels about one foot [30 centimeters]," said Dennis McCarthy of the U.S. Naval Observatory in Washington, D.C.

"So for navigational accuracy, [even a] billionth of a second can be important."

Mobile phone networks have blacked out in past years when their timekeeping got out of sync because of failure to observe the leap second, said Judah Levine of the National Institute of Standards and Technology in Boulder, Colorado.

The electric power grid is also vulnerable.

"Companies share power and it's very important that all generating stations are running at the same frequency," said Levine, sometimes called the nation's timekeeper. "That's a very serious issue."

Goodbye, Leap Second?
Arias of the International Bureau of Weights and Measures is part of a working group that's arguing to abolish the leap second.

"The leap second was created in 1972 because there was a need to have a time scale somehow linked to rotational time," she said.

"At that time celestial navigation was common, and people needed to have time linked to the rotation of the Earth."

"Today we don't need to the leap second for navigation, because the GPS system exists for finding directions in the sea, or anywhere on Earth."

But if the leap second is abolished, it could cause problems for astronomers. Complex adjustments may be needed for research that has long relied on a strong connection between clocks and the sun.

For now, the leap second ticks on, despite the fact that its implications can rattle even the nation's timekeeper.

"It can become super-duper confusing," Levine said.

Mysterious African 'Fairy Circles' Stump Scientists

ORIGINAL: Live Science
Stephanie Pappas, LiveScience Senior Writer
27 June 2012

Mysterious bare spots called "fairy circles" dotting the sandy desert grasslands of Nambia have long stumped scientists who have no idea how the strange patterns form. CREDIT: Mike and Ann Scott of the NamibRand Nature Reserve
In the sandy desert grasslands of Namibia in southern Africa, mysterious bare spots known as "fairy circles" will form and then disappear years later for no reason anyone can determine. A new look at these strange patterns doesn't solve the wistful mystery but at least reveals that the largest of the circles can linger for a lifetime.

Small fairy circles stick around an average of 24 years, while larger ones can exist as long as 75 years, according to research detailed today (June 27) in the journal PLoS ONE. Still, the study sheds little light on why the circles form , persist and then vanish into the landscape after decades.

"The why question is very difficult," said study researcher Walter Tschinkel, a biologist at Florida State University. "There are a number of hypotheses on the table, and the evidence for none of them is convincing." [ See Photos of Fairy Circles ]

Circles of life (and death)

Tschinkel grew interested in fairy circles during a 2005 safari to NamibRand Nature Reserve in southwest Namibia, in the Namib Desert. It was his first experience with the round clearings, tens of thousands of which expose the red sandy soil in the area. A short time after the circles form, a tall ring of grass grows around the border, highlighting the bare area.
The smallest are about 6.5 feet (2 meters) in diameter, while the largest can be almost 40 feet (12 m) across. Eventually, plants move back in, re-colonizing the circles and leaving only slightly indented "ghost circles" behind. CREDIT: Mike and Ann Scott of the Namib Rand Nature Reserve
Few researchers have studied fairy circles, in part because of their remoteness, 111 miles (180 km) from the nearest village. It's an arid landscape where springbok, ostriches, leopards and other large animals roam, Tschinkel told LiveScience.

"It's like dying and going to heaven if you like remote, beautiful desert places," he said.

At first glance, Tschinkel assumed the circles marked underground nests of harvester termites. But digs have shown no evidence of termite nests under fairy circles. Other explanations, such as differences in soil nutrients or the death of seedlings by toxic vapors from the ground, have likewise failed to hold up to study.

In fact, little was known even about the life cycle of the circles, Tschinkel said. With the help of the nature reserve's staff, satellite images and aerial photos, he set out to change that. By comparing satellite images from 2004 and 2008, he found that circles are quite stable, popping up at nearly their full size, or growing quickly to full size once they get started. The smallest are about 6.5 feet (2 meters) in diameter, while the largest can be almost 40 feet (12 m) across. Winds scour the bare areas of soil, turning them into slight depressions. Eventually plants move back in, recolonizing the circles and leaving only slightly indented "ghost circles" behind. [ Gallery: Aerial Photos Reveal Mysterious Stone Structures ]

Assuming that the overall number of fairy circles on the landscape is fairly steady, Tschinkel used the satellite photos to look at how quickly the circles go from birth to maturity to revegetation. That yielded rough estimates of the circles' life spans. Most probably exist for 30 to 60 years, Tschinkel said.

Persisting mystery

Tschinkel was able to bolster these estimates thanks to a fundraising effort by the Namib Rand Nature Reserve, which sells sponsorships to fairy circles. The sponsored circles are marked with a ceramic plate, and their GPS coordinates are recorded. Over the 10 years of the sponsorship program, staff members have checked on the status of the sold circles. Their data yielded similar age ranges for fairy circles as the satellite images did, Tschinkel found.

He also determined that the circles form only on sandy soil with minimal stoniness, and that they don't form on shifting dunes or alluvial fans, where sands are deposited by water.

Some of Tschinkel's experiments are still ongoing, but so far, they've generated no leads on the circles' origins. Tschinkel suspects the circles are the product of some form of natural self-organization by plants.

"There are some mathematical models that are based on the idea that plants can withdraw resources toward themselves, which has a positive feedback on plant growth where they're located, but it has a negative effect on plants at a greater distance," he said.

Computer models based on this math can generate landscapes that look a bit like the fairy circle fields of Namibia, he said. But even if that hypothesis is on the right track, it doesn't explain how the plants are creating this pattern, not when hoarding soil nutrients and some other possible factors have already been ruled out.

With few people studying the circles — and no funding for chasing down the mysteries of the landscape of southern Africa — Tschinkel said the fairy circles will likely remain an enigma.

"I'm not too worried that this mystery is going to be solved anytime soon," he said. And the persistence of the mystery makes it ever more intriguing.

"That's science, isn't it?" Tschinkel said. "If you knew the answer ahead of time, it wouldn't be much fun."

Follow Stephanie Pappas on Twitter @sipappas or LiveScience @livescience . We're also on Facebook & Google+ .

The melting Artic

ORIGINAL: The Economist

Warming temperatures due to climate change are dramatically changing the environment in the Arctic. The impact will be felt around the world

jueves, 28 de junio de 2012

Verdéate: Reta tu lado verde

¿Qué tal si comienzas a reducir tu impacto medioambiental tomando un Reto Verde?

Ponemos a tu disposición nuestra experiencia y creatividad a través de los siguiente servicios. Si deseas información específica para alguno de ellos sólo tienes que dar click en "+ Información". Te enviaremos una propuesta personalizada a tus necesidades.

miércoles, 27 de junio de 2012

Chinese student builds his own solar car for $2400

ORIGINAL: Ecofriend
Apr 10 2012

We all profess the use of electric vehicles and methods such as carpooling to help cut down on emissions and reduce your own carbon footprint. Each day commuters across the globe add the huge amounts of carbon gases into the atmosphere and most of them do not even realize or worry too much about the damage they are causing to the planet’s environment. But Zhuzhen Lin is someone who has decided to tackle the problem head on and do his little bit by not depending on the fossil fuel powered vehicles. Student of Zhejiang Xiangshan schools, he has built his own solar car, which cost him around $2400.

Zhejiang 19-year-old technical school 15000 create solar cars
The car can travel 70 kilometers in one charge.

The car built by this 19 year old is not just all solar, as you can even hook its batteries up to grid power on a rainy day to still cruise around without any hassles. The car has a range of about 70 Km when fully charged and can hit maximum speeds of about 40 km/hr. the solar powered car draws its energy from the 22 photovoltaic panels that are installed on its roof, sides and rear. This basically does away with any worries about aesthetics and squarely puts function ahead of form.

The best part is that Lin could craft up the solar car for just 15000 Yuan and that comes to around $2400. Creating a solar car for that price tag might be a good way forward for more such users who are not too worried about the design and just want to get a green ride without having to fork out huge amounts of cash for it. With a few improvements and tweaks, maybe one can have a commercialized version as well.

Via: Tieba

Urge planificación sostenible de La Mojana

Por: Leonel Vega Mora, Profesor e investigador, Departamento de Ingeniería Civil y Agrícola - Universidad Nacional de Colombia
Jun. 09 de 2012

Unos 400 mil habitantes, distribuidos en 11 municipios y 4 departamentos, viven en la zona de La Mojana. Miles sufren los rigores de las inundaciones.
El dique marginal del río Cauca fue construido de forma deficiente, sin seguir todas las recomendaciones técnicas planteadas por la UN. - Fotos: Cortesía Leonel Vega Mora
Problemas sociales, económicos y hasta de seguridad afrontan los habitantes de La Mojana a causa de las inundaciones. Los más afectados son los niños.
Una detallada y exhaustiva investigación hecha por la Universidad Nacional de Colombia entrega recomendaciones técnicas para el ordenamiento ambiental y el desarrollo territorial de esta depresión terrestre del Caribe colombiano. Se requiere adecuar los caños receptores y reconstruir el dique marginal del río Cauca para controlar las inundaciones. El documento ya está en manos del Gobierno nacional.

La región de La Mojana forma parte de la depresión momposina, una gran zona baja inundable que se formó a finales de la era Terciaria (hace 20 o 30 millones años) por el lento hundimiento de la placa tectónica del Caribe bajo la placa de Suramérica.

 Desde su formación, ha sido irrigada por los desbordes naturales del río Cauca en su margen izquierda, lo que ha conformado un sistema hídrico de drenaje que involucra múltiples caños y ciénagas. Esto posibilita la distribución de agua y sedimentos, función básica que garantiza el aporte continuo de nutrientes y el mantenimiento de la riqueza ecosistémica de la región.
Este enorme humedal, de alto valor estratégico para el desarrollo del Caribe colombiano, constituye un gran “delta interno” en el que confluyen los ríos San Jorge, Cauca, Nechí y Magdalena (región Brazo de Loba), que presta cuantiosos e indispensables servicios ambientales.

Aunque el Gobierno nacional ha definido estudios, políticas, planes y programas, la región presenta problemas sociales, económicos, institucionales y ambientales, por no mencionar los de orden público.

La mayoría son consecuencia de obras inadecuadas. En primer lugar, de la construcción de la carretera San Marcos-Majagual-Achí, que se diseñó y construyó sin las condiciones ambientales necesarias para garantizar el libre flujo de agua a través de los caños que recogen las aguas desbordadas del Cauca.

Y, en segundo lugar, de la construcción del dique marginal de este río, entre Nechí y Achí, que fue erigido sin tomar en cuenta muchas de las especificaciones técnicas del diseño original –elaborado por la Universidad Nacional de Colombia–, orientadas a garantizar el desborde controlado de las aguas hacia los caños de La Mojana.

Las dos megaestructuras provocaron cambios importantes en el régimen hídrico y sedimentario del ecosistema. Se pueden distinguir tres zonas definidas:
  • la más baja (al norte), en donde las inundaciones duran, en promedio, seis meses; 
  • la intermedia, en las que se extienden entre tres y cuatro meses; y 
  • la más alta (al sur), en las que duran menos de tres meses.

El 7 de junio de 2011, el Gobierno nacional, a través del Departamento Nacional de Planeación (DNP), celebró con la UN un convenio interadministrativo cuyo fin es “aunar esfuerzos para la formulación de estrategias de corto plazo que requiere el ordenamiento ambiental y el desarrollo territorial de la región de La Mojana; particularmente para la realización de estudios, análisis y recomendaciones sobre las obras de infraestructura necesarias y prioritarias”.

Así, se constituyó el equipo de trabajo UN-Mojana, coordinado técnicamente por profesores de Bogotá y Medellín que son apoyados por estudiantes de maestría y pregrado, profesionales externos y funcionarios de labores administrativas.

Su trabajo incluyó buena parte de los cauces y paleocauces (ríos secos que se reactivan en tiempos de grandes lluvias) del sistema fluvial del río Cauca. Durante la labor de fotointerpretación, el equipo confirmó un amplio sistema de paleocauces en la zona central (caño San Matías, Rabón, la Sangre, La Mojana y Panceguita, entre otros), que evidencian un periodo reciente (holoceno superior) de sedimentación y cambios de curso (avulsión).

En cuanto a la dinámica fluvial reciente, corroboró un proceso de formación de rompederos (sitios donde el agua daña las obras de contención), en la margen izquierda del río Cauca y, en menor medida, en la margen derecha. Este indica una lenta acumulación de sedimentos (colmatación) en el curso actual del río, que lo obliga a buscar vías alternas de circulación y que puede ser acrecentado por los aportes de la minería aluvial de oro que se presenta en sectores del bajo Cauca y Nechí.


La modelación matemática, desarrollada por el profesor Luis Alejandro Camacho –de la Facultad de Ingeniería de la UN en Bogotá–, permitió comparar alternativas de manejo hídrico y de sedimentos, así como identificar los problemas de inundaciones y de disponibilidad del agua en diferentes condiciones hidrológicas.

Los resultados más importantes tienen que ver con la verificación del comportamiento hidráulico de los diques-vertederos, en los siete sitios que se proponen como alternativa de control del río.

Las predicciones del modelo muestran que la alternativa propuesta es viable hidráulicamente y que reduciría las inundaciones en cerca de 25.150 millones de metros cúbicos.

Además, indican que el sistema sería capaz de mantener el área sin inundaciones por un periodo de cincuenta años. Para un nivel de protección más alto –por ejemplo, de cien años–, sería necesario ampliar más los canales y modificar las estructuras de vertimiento elevando el dique a una cota mayor.

Dique marginal

La evaluación del dique marginal del río Cauca –coordinada por la profesora Lilian Posada, de la Facultad de Minas de la UN en Medellínestableció que el diseño original (entregado por la UN) cumplía con las especificaciones técnicas de control del agua de desborde.

Sin embargo, fue construido de forma deficiente y sin seguir muchos de los lineamientos establecidos, como, por ejemplo, ser multipropósito (control de inundación y vía carreteable), disponer de diques-vertederos (en los sitios críticos para garantizar los caudales de desborde) o estar alineado a una distancia considerable del lecho menor del río.

El análisis de sus puntos críticos llevó a diseñar refuerzos para el terraplén y a recomendar protecciones para las bancas del canal, en donde el dique –aun en buen estado– se ve amenazado por la socavación y erosión de las bancas. Para los tramos más deteriorados se rediseñaron nuevos diques-vertederos, más alejados de la orilla.

Regresar los caudales

El estudio de viabilidad, adelantado por los profesores Jaime Iván Ordóñez, Gabriel Pinilla, Kim Robertson y Leonel Vega –bajo la coordinación del profesor Luis Alejandro Camacho–, determinó que no resulta viable la idea de hacer un canal paralelo a la carretera San Marcos-Achí ni la de mejorar solo un canal de los existentes (el del caño Rabón, que es paralelo a la vía en la mayor parte de su recorrido).

Como complemento, el análisis ambiental de los caños y ecosistemas de la zona media y baja, coordinado por la profesora Lilian Posada, confirmó la necesidad de regresar los caudales a la región, para detener el deterioro causado por la falta de conectividad del río con los humedales.

Se requiere, entonces, ingresar una cantidad mayor de agua a través de diques-vertederos, pero adecuando los caños receptores. Para esto, se hace necesaria no solo la reconstrucción del dique marginal, con sus correspondientes diques-vertederos, sino también la adecuación y mejoramiento de casi todos los caños o, al menos, de los más importantes (Rabón, Pescado y Muñoz, Barro y San Matías, así como Mojana y Pancegüita).


En general, el equipo de la UN considera que cualquier planteamiento de alternativas de control de inundaciones para La Mojana debe basarse en un entendimiento claro 

  • de las condiciones geológicas y geomorfológicas del área, 
  • de la naturaleza del sistema de drenaje, 
  • de las características físicas, bióticas y socioeconómicas del medioambiente y 
  • de los efectos de la infraestructura actual.
En este sentido, se hace prioritario efectuar las siguientes actividades, cuyo fin es garantizar un mínimo de información básica de la región:

  1. instrumentación hidrometeorológica de la red Ideam
  2. levantamiento altimétrico de precisión (mediante lidar) de ríos y caños de La Mojana; 
  3. levantamiento topobatimétrico de ciénagas; 
  4. campañas de calidad del agua para la calibración del modelo integrado; 
  5. actualización del modelo matemático.
De otra parte, la profesora Verónica Botero, de la Escuela de Geociencias y Medioambiente de la UN en Medellín, en su diagnóstico sobre las prácticas e instrumentos de gestión, demostró que no existe articulación entre lo regional y lo local, lo que lleva a una planificación fragmentada del territorio.

Además, encontró que se desconocen los factores que intervienen en el riesgo de inundación, así como la relación que este tiene con los diferentes componentes del desarrollo y del ordenamiento. Igualmente, halló que la capacidad de gestión del riesgo de los municipios es baja, lo que los hace más vulnerables.

Por eso, plantea revisar el actual sistema de gestión y diseñar un nuevo modelo institucional y político que englobe todos sus aspectos en una política nacional de riesgo, debidamente instrumentalizada.

Finalmente, mediante el proceso de evaluación sistémica de la dimensión ambiental, adelantado por el profesor Leonel Vega, fue posible identificar, valorar y hacer el análisis cualitativo de impactos ambientales para cuatro escenarios de intervención humana: 

  • condición antigua, 
  • actual, 
  • mejorada y 
  • ambientalmente sostenible.
Se requiere proceder al análisis cuantitativo, a fin de definir las medidas de manejo ambiental más efectivas para mitigar, compensar y eliminar dichos impactos; así como para garantizar el ordenamiento, planificación y desarrollo territorial sostenible de La Mojana.


La modelación matemática, que muestra las variaciones en el tiempo de la información hidrológica de la zona (hidrogramas) para cada uno de los caños receptores, comprobó, en todos los casos, que la capacidad hidráulica de los canales es suficiente para evacuar los caudales a través de secciones ampliadas mediante dragado.

Para la adecuación de los caños existen dos alternativas, que difieren en cómo disponen el material extraído de las paredes y del lecho del canal. La primera contempla dejarlo en el mismo lecho, pero empaquetado en contenedores que, a la vez, refuerzan la base del talud del canal y lo estabilizan. Esta solución es la más costosa.

La segunda contempla disponerlo en la planicie dentro de pozos recubiertos con un textil y adecuadamente drenados para regresar las aguas de precipitación al canal.

La elección de una u otra alternativa deberá hacerse después de analizar, en cada caño, la calidad de los sedimentos y, por supuesto, los costos.

Las anteriores son solo algunas de las recomendaciones que entregan los profesionales de la UN, luego de un exhaustivo y minucioso trabajo investigativo. En manos del Estado colombiano está el apropiarse de estos estudios y ejecutar las obras con los criterios técnicos entregados, para contribuir así al mejoramiento de la calidad de vida de sus habitantes y al desarrollo sostenible de la región.