viernes, 30 de noviembre de 2012

A New, Genetically Distinct Lion Population is Found

November 30, 2012

Photo courtesy of Joerg Junhold and Klaus Eulenberger, Leipzig Zoo.
In a twist on the Lion King’s “Circle of Life,” a group of researchers identified a population of genetically distinct lions—in a zoo. The finding came after an Addis Ababa zoo asked researchers in its sister city of Leipzig to help prove that their lions not only looked unusual, but were genetically unique. The finding would help the struggling zoo to obtain funding to continue breeding the lions and to improve their living conditions.

The Addis Ababa zoo lions have dark manes and small bodies, unlike other African lions. But life in captivity can sometimes influence appearance. A team of researchers, led by the Max Planck Institute for Evolutionary Anthropology in Germany and the University of York in the UK, checked to see if the lions really are different by comparing DNA samples of 15 lions from the zoo to six populations of wild lions.

Their genetic analysis revealed that the gene sequence of all fifteen lions were unique and showed little sign of inbreeding. The study was recently published in the European Journal of Wildlife Research (

The zoo’s lions belonged to Ethiopia’s deceased emperor, Haile Selassie, who established the zoo in 1948. But their origins are unknown. One theory is that the seven founder lions—five males and two females—came from southwestern Ethiopia. Wild lions that look like this may no longer live there because their strikingly dark mane proved too alluring to hunters.

Since the wild source population is unknown, we cannot be sure whether it still exists,” says lead author Susann Bruche. “Lions with similar appearance have been largely diminished mainly due to hunting for their mane.

Bruche says that according to the Ethiopian authorities, lions that resemble the zoo lions still exist in the east and northeast of the country, in the Babille Elephant Sanctuary and in a wildlife rescue facility in Ensessakotteh.(

This isn’t the first lion population to survive only in zoos. Two significant lion populations, the North African Barbary lions and the South African Cape lions, have already become extinct in the wild. As Ethiopia’s population of lions declines, “Every effort should be made to maintain this population to keep the genetic heritage alive,” says Bruche.

Construction work is currently underway in the Addis Ababa zoo to create a facility modeled on the lions’ natural environment. The zoo will continue to breed the lions to keep the population alive.

NBDNano doing a conceptual design of a self-filling water bottle


NBD makes use of a nano-scale surface to enhance water condensation. Mimicking the Namib Desert Beetle, our nanotechnology can be used to collect water in the most arid regions of the world. 

Our Technology
(Photo From: Moongateclimber/Wikipedia Commons )

Superhydrophobic and superhydrophilic surfaces have a variety of commercial applications. NBD is targeting water harvesting by employing these alternating chemical surface features in varied micro-patterns/arrays affording unique and uncharacteristic properties. Our surface engineering solutions are based on years of research of coming from elite university laboratories in a range of fields, including materials science and chemical engineering.

  • Enhanced dehumidification for house-hold consumers
  • Production of potable water for military operations
  • Production of water for greenhouses to support plant life
  • Production of potable water for third world nation
NBD is currently in a heavy R&D phase, during which we will be optimizing our chemical coatings and building prototypes of devices to utilize these coatings - including a conceptual design of a self-filling water bottle. We will also be exploring additional uses of these unique coatings, in order to best position ourselves for a launch in 2014-2015. Thank you for your support!

Our Team
Miguel is a co-founder of NBD with a background in startups. While this is his second stint at starting a company, he also has worked at TechStars, an early stage investor in seed startups. He has a degree in Biology from Boston College.
Andy is a co-founder and lead chemist. Andy has several years of experience in organic chemistry and has presented his work at a number of conferences including local, national, and international venues. Andy is now a grad student at MIT working towards his PhD in Organic Chemistry. He is a graduate of Trinity College.
Deckard is a co-founder of NBD with a background in biomimicry. Deckard had the inspiration for this company while taking a class about the Namib Desert Beetle. He has a degree in Biology with a concentration in bioinformatics from Boston College.

Rob is the lead engineer for NBD. Rob is a mechanical engineer from Northeastern University and has a widespread background in aerospace, medical, and consumer product design. Rob has also worked as a design consultant for several Boston based startups.

La quinta edición de las Perspectivas del Medio Ambiente Mundial (GEO-5)


El mundo sigue precipitándose por una pendiente no sostenible a pesar de los más de quinientos objetivos acordados a nivel internacional para respaldar la gestión sostenible del medio ambiente y mejorar el bienestar humano, según la nueva evaluación de gran alcance coordinada por el Programa de las Naciones para el Medio Ambiente (PNUMA).

La zona del gran delta del río Perla, al sureste de China, constituye la «megarregión» más grande del mundo con una población de aproximadamente 120 millones de personas (ONU, 2010). En los últimos veinte años, las poblaciones de las ciudades del delta Guangzhou y Shenzhen han alcanzado, cada una, los casi 10 millones de personas, mientras que Hong Kong, Foshan y Dongguan han crecido hasta alrededor de 5 millones cada una (ONU, 2009). Empiezan a desdibujarse las fronteras entre las ciudades para conformar una sola gran mancha urbana. En la zona central del delta que aparece en la imagen había poco más de 20 millones de personas a principios de la década de 1990, pero desde entonces la población se ha triplicado hasta alcanzar prácticamente 60 millones (SEDAC, 2010). Esta intensa urbanización ha causado la pérdida de tierras productivas y áreas naturales, además de otros problemas ambientales (Yan et al., 2009).

jueves, 29 de noviembre de 2012

MESSENGER Finds New Evidence for Water Ice at Mercury's Poles


Mercury's North Polar Region Acquired By The Arecibo Observatory

A Mosaic of MESSENGER Images of Mercury's North Polar Region

Permanently Shadowed Polar Craters

New observations by the MESSENGER spacecraft provide compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters. 

Three independent lines of evidence support this conclusion: the first measurements of excess hydrogen at Mercury's north pole with MESSENGER's Neutron Spectrometer, the first measurements of the reflectance of Mercury's polar deposits at near-infrared wavelengths with the Mercury Laser Altimeter (MLA), and the first detailed models of the surface and near-surface temperatures of Mercury's north polar regions that utilize the actual topography of Mercury's surface measured by the MLA. These findings are presented in three papers published online today in Science Express

Given its proximity to the Sun, Mercury would seem to be an unlikely place to find ice. But the tilt of Mercury's rotational axis is almost zero — less than one degree — so there are pockets at the planet's poles that never see sunlight. Scientists suggested decades ago that there might be water ice and other frozen volatiles trapped at Mercury's poles. 

The idea received a boost in 1991, when the Arecibo radio telescope in Puerto Rico detected unusually radar-bright patches at Mercury's poles, spots that reflected radio waves in the way one would expect if there were water ice. Many of these patches corresponded to the location of large impact craters mapped by the Mariner 10 spacecraft in the 1970s. But because Mariner saw less than 50 percent of the planet, planetary scientists lacked a complete diagram of the poles to compare with the images. 

MESSENGER's arrival at Mercury last year changed that. Images from the spacecraft's Mercury Dual Imaging System taken in 2011 and earlier this year confirmed that radar-bright features at Mercury's north and south poles are within shadowed regions on Mercury's surface, findings that are consistent with the water-ice hypothesis. 

Now the newest data from MESSENGER strongly indicate that water ice is the major constituent of Mercury's north polar deposits, that ice is exposed at the surface in the coldest of those deposits, but that the ice is buried beneath an unusually dark material across most of the deposits, areas where temperatures are a bit too warm for ice to be stable at the surface itself. 

MESSENGER uses neutron spectroscopy to measure average hydrogen concentrations within Mercury's radar-bright regions. Water-ice concentrations are derived from the hydrogen measurements. "The neutron data indicate that Mercury's radar-bright polar deposits contain, on average, a hydrogen-rich layer more than tens of centimeters thick beneath a surficial layer 10 to 20 centimeters thick that is less rich in hydrogen," writes David Lawrence, a MESSENGER Participating Scientist based at The Johns Hopkins University Applied Physics Laboratory and the lead author of one of the papers. "The buried layer has a hydrogen content consistent with nearly pure water ice.

Data from MESSENGER's Mercury Laser Altimeter (MLA) — which has fired more than 10 million laser pulses at Mercury to make detailed maps of the planet's topography — corroborate the radar results and Neutron Spectrometer measurements of Mercury's polar region, writes Gregory Neumann of the NASA Goddard Space Flight Center. In a second paper, Neumann and his colleagues report that the first MLA measurements of the shadowed north polar regions reveal irregular dark and bright deposits at near-infrared wavelength near Mercury's north pole. 

"These reflectance anomalies are concentrated on poleward-facing slopes and are spatially collocated with areas of high radar backscatter postulated to be the result of near-surface water ice," Neumann writes. "Correlation of observed reflectance with modeled temperatures indicates that the optically bright regions are consistent with surface water ice."
The MLA also recorded dark patches with diminished reflectance, consistent with the theory that the ice in those areas is covered by a thermally insulating layer. Neumann suggests that impacts of comets or volatile-rich asteroids could have provided both the dark and bright deposits, a finding corroborated in a third paper led by David Paige of the University of California, Los Angeles

Paige and his colleagues provided the first detailed models of the surface and near-surface temperatures of Mercury's north polar regions that utilize the actual topography of Mercury's surface measured by the MLA. The measurements "show that the spatial distribution of regions of high radar backscatter is well matched by the predicted distribution of thermally stable water ice," he writes. 

According to Paige, the dark material is likely a mix of complex organic compounds delivered to Mercury by the impacts of comets and volatile-rich asteroids, the same objects that likely delivered water to the innermost planet.The organic material may have been darkened further by exposure to the harsh radiation at Mercury's surface, even in permanently shadowed areas. 

This dark insulating material is a new wrinkle to the story, says Sean Solomon of the Columbia University's Lamont-Doherty Earth Observatory, principal investigator of the MESSENGER mission. "For more than 20 years the jury has been deliberating on whether the planet closest to the Sun hosts abundant water ice in its permanently shadowed polar regions. MESSENGER has now supplied a unanimous affirmative verdict.

"But the new observations have also raised new questions," adds Solomon. "Do the dark materials in the polar deposits consist mostly of organic compounds? What kind of chemical reactions has that material experienced? Are there any regions on or within Mercury that might have both liquid water and organic compounds? Only with the continued exploration of Mercury can we hope to make progress on these new questions.

For more information about the MESSENGER mission, visit: and

Humans Have Been Evolving Like Crazy Over the Past Few Thousand Years

November 29, 2012 10:58 am
A DNA molecule Photo: ynse / Wikimedia Commons
It’s a common argument of the know-it-all teen, fresh from an introductory biology course: “Life is so cushy now,” he might say, “People aren’t even evolving anymore.” As the argument goes, most people live a decently long life and have a chance to pass on their genes, since we aren’t so often being gobbled up by lions or succumbing to now-curable diseases. With this comes a dampening on the forces of natural selection, and a stagnation, or even weakening, of the human species.

But the truth, it seems, couldn’t be more different. Over the past 5 to 10 thousand years, says Nature, reporting on a new study, the genetic diversity in the human population has exploded, a bloom that serves as stage one in the process of evolution.

The human genome has been busy over the past 5,000 years. Human populations have grown exponentially, and new genetic mutations arise with each generation. Humans now have a vast abundance of rare genetic variants in the protein-encoding sections of the genome.

Brandon Keim, writing in Wired, says, “As a species, we are freshly bursting with the raw material of evolution.”

Most of the mutations that we found arose in the last 200 generations or so. There hasn’t been much time for random change or deterministic change through natural selection,” said geneticist Joshua Akey of the University of Washington, co-author of the Nov. 28 Nature study. “We have a repository of all this new variation for humanity to use as a substrate. In a way, we’re more evolvable now than at any time in our history.

Most of the new genetic shifts are extremely rare, appearing in only a small slice of the human population. The researchers look at their newly unveiled realization of the breadth of human diversity in terms of what it could mean for trying to understand the genetic basis of a number of diseases, or in what it tells us about humanity’s evolution history. But what it also means is that—come the emergence of a new disease or the turned tide of the zombie apocalypse—BAM, rapid evolution. Bring it, selection pressures. We got this.

miércoles, 28 de noviembre de 2012

Beneath 50-foot ice layer, an Antarctic lake full of life

By Jon Bardin
November 27, 2012, 9:07 a.m.
Lake Vida, an Antarctic lake sealed under 50 feet of ice, is nonetheless teeming with bacteria, according to a new study. Above, the researchers' field camp at Lake Vida during the study.(Emanuele Kuhn / Desert Research Institute)
Beneath a 50-foot-thick sheet of ice, the salty, frigid Antarctic Lake Vida is somehow teeming with life. That’s according to a report published Monday in the Proceedings of the National Academy of Sciences.

Lake Vida provides a unique test of what happens to life over long periods of time when organisms are exposed to extremely harsh conditions. The layer of ice completely seals off the lake. The water is 13 degrees below zero Celsius, is very salty and contains no oxygen.

Nonetheless, when researchers drilled through the ice to carefully sample what lies below, they found the lake was full of life even though it has been sealed off for around 2,800 years: Vida contained about one-tenth the microbial life of a lake in a mild climate under average environmental conditions, an amount far above what the researchers expected.

Researchers using DNA analysis identified 32 species of bacteria from eight phyla but found no archaea, a category of microbes considered distinct from bacteria that tend to live in extreme environments.

Based on the amount of time the lake has been closed off, the researchers had anticipated that it would be nearing the end of its energy stores. But given the robust bacterial world they found, that seemed not to be the case.

That means a major source of energy is likely coming from elsewhere — potentially from hydrogen released via chemical reactions taking place between the water and iron contained in the rocks on lake floor. But the researchers remain unsure exactly how life has survived under the ice of Lake Vida.

It’s a topic certain to receive further attention, both because it may shed light on how life evolved on Earth, and it may provide clues as to how life could potentially exist on other planets that have environments unlike the one we are used to.

Return to the Science Now blog.

Copyright © 2012, Los Angeles Times

Tiny Algae Shed Light on Photosynthesis as a Dynamic Property

One of the first chemical reactions children learn is the recipe for photosynthesis, combining carbon dioxide, water and solar energy to produce organic compounds. Many of the world’s most important photosynthetic eukaryotes such as plants did not develop the ability to combine these ingredients themselves. Rather, they got their light-harnessing organelles—chloroplasts—indirectly by stealing them from other organisms. In some instances, this has resulted in algae with multiple, distinct genomes, the evolutionary equivalent of a “turducken*.

Chloroplasts originally evolved from photosynthetic bacteria by primary endosymbiosis, in which a bacterium or other prokaryote is engulfed by a eukaryotic host. The chloroplasts of red and green algae have subsequently come to reside within other, previously non-photosynthetic eukaryotes by secondary endosymbiosis. Such events have contributed to the global diversity of photosynthetic organisms that play a crucial role in regulating and maintaining the global carbon cycle. In most organisms that acquired photosynthesis by this mechanism, the nucleus from the ingested algal cell has disappeared, but in some cases it persists as a residual organelle known as a nucleomorph. Such organisms have four distinct genomes.

Photo: Primary and secondary endosymbiosis is depicted in this diagram, which shows movement of DNA from the cyanobacterial progenitor of plastids to the primary host nucleus and, subsequently, to the nucleus of the secondary host. (John M. Archibald, Dalhousie University, Canada)
To better understand the process of secondary endosymbiosis and why nucleomorphs persist in some organisms, an international team composed of 73 researchers at 27 institutions, including the U.S. Department of Energy Joint Genome Institute (DOE JGI), collaborated to sequence and analyze the genomes and transcriptomes (the expressed genes) of two tiny algae. The team led by John Archibald of Canada’s Dalhousie University published their findings on the algae Bigelowellia natans and Guillardia theta ahead online November 29, 2012 in Nature.

Archibald compared these algae to Russian nesting dolls with “sophisticated sub-cellular protein-targeting machinery” and four genomes derived from the two eukaryotes that merged over time. Approximately 50 percent of the genes in both genomes are 'unique' with no obvious counterpart in other organisms,” he added. “This indicates just how different they are from characterized species.

Photo: SEM of the endosymbiotic algae G. theta the first cryptophyte to be sequenced. 
(Dr. Geoff McFadden, University of Melbourne, Australia)
DOE JGI Fungal Genomics Program head Igor Grigoriev called B. natans and G. theta “living fossils” because of the remnant nucleomorph. He added that algae are relevant to the Department of Energy Office of Science research portfolio for their potential applications in the fields of bioenergy and environment, noting that the DOE JGI has published over 75 percent of the publicly available algal genomes. “Iterations of endosymbiosis have led to a global diversity of these primary producers. Sequencing these two algae, the first cryptophyte and the first chlorarachniophyte sequenced, helped us to fill in the gaps in the Eukaryotic Tree of Life, and obtain additional references for better understanding of eukaryotic evolution.

Archibald said that “G. theta and B. natans both possess a surprisingly complex suite of enzymes involved in carbon metabolism, and thus represent a useful resource for scientists engaged in both basic and applied research, including photosynthesis, sub-cellular trafficking and biofuels development.

The DOE JGI sequenced the genomes of B. natans (95 million nucleotides or bases: Mb) and G. theta (87 Mb) from single cell isolates provided by Bigelow Laboratory for Ocean Sciences as part of the 2007 Community Sequencing Program portfolio. In addition, the transcriptomes were sequenced separately by the National Center for Genome Resources in New Mexico. Among the team’s findings is an answer to the question of why nucleomorphs still exist.

Photo: SEM of B. natans the first chlorarachniophyte to be sequenced. 
(Dr. Geoff McFadden, University of Melbourne, Australia)
The reason for the persistence of nucleomorphs in both organisms appears to be surprisingly simple: they are no longer able to transfer their DNA to the host cell nucleus by the process of endosymbiotic gene transfer,” said Archibald. Unlike most other secondarily photosynthetic eukaryotes in which the endosymbiont’s genetic matter has completely migrated over to the host, in cryptophytes and chlorarachniophytes the nucleus and chloroplast from the engulfed algae remain partitioned off from the host cell. “As a consequence,” he added,“ genetic and biochemical mosaicism is rampant in G. theta and B. natans.

Both researchers highlighted the unexpected finding of alternative splicing in B. natans. Grigoriev noted that the phenomenon is one typical for higher eukaryotes, and Archibald added that the levels “greatly exceed that seen in the model plant Arabidopsis and on par with the human cerebral cortex, unprecedented and truly remarkable for a unicellular organism. This challenges the paradigm that complex alternative splicing is a phenomenon limited to sophisticated multicellular organisms.

The evolution of chloroplasts, the photosynthetic compartments of plants and algal cells, is complex but has had a profound effect on our planet,” said Chris Howe, Professor of Plant and Microbial Biochemistry at Cambridge University in England. “This paper gives us fascinating insights into how host and nucleomorph genomes have been remodeled during evolution. As well as providing a goldmine of information on the general biology of these organisms, the paper shows us that the nucleomorph genomes have probably persisted simply because the mechanism for transfer of genes to the nucleus was closed off, rather than because nucleomorphs had to be retained as separate entities. The paper also shows us that the evolutionary history of the nucleomorph-containing organisms was even more complex than we thought, with evidence for genes from many different sources in their nuclei. Overall, it has provided important insights into the fundamental processes of cell symbiosis and genome reshaping that have produced some of the most important organisms we see today.

*a seasonal dish that consists of a deboned chicken stuffed into a deboned duck, which itself is stuffed into a deboned turkey.

The U.S. Department of Energy Joint Genome Institute, supported by the DOE Office of Science, is committed to advancing genomics in support of DOE missions related to clean energy generation and environmental characterization and cleanup. DOE JGI, headquartered in Walnut Creek, Calif., provides integrated high-throughput sequencing and computational analysis that enable systems-based scientific approaches to these challenges. Follow @doe_jgi on Twitter.

DOE’s Office of Science is the largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit

DNA imaged with electron microscope for the first time

ORIGINAL: New Scientist
November 2012 

It's the most famous corkscrew in history. Now an electron microscope has captured the famous Watson-Crick double helix in all its glory, by imaging threads of DNA resting on a silicon bed of nails. The technique will let researchers see how proteins, RNA and other biomolecules interact with DNA.
It may be why life is screwed up (Image: Enzo di Fabrizio)
The structure of DNA was originally discovered using X-ray crystallography. This involves X-rays scattering off atoms in crystallised arrays of DNA to form a complex pattern of dots on photographic film. Interpreting the images requires complex mathematics to figure out what crystal structure could give rise to the observed patterns.

The new images are much more obvious, as they are a direct picture of the DNA strands, albeit seen with electrons rather than X-ray photons. The trick used by Enzo di Fabrizio at the University of Genoa, Italy, and his team was to snag DNA threads out of a dilute solution and lay them on a bed of nanoscopic silicon pillars.

A tightrope of DNA between two silicon nanopillars (Image: Enzo di Fabrizio)

The team developed a pattern of pillars that is extremely water-repellent, causing the moisture to evaporate quickly and leave behind strands of DNA stretched out and ready to view. The team also drilled tiny holes in the base of the nanopillar bed, through which they shone beams of electrons to make their high-resolution images. The results reveal the corkscrew thread of the DNA double helix, clearly visible. With this technique, researchers should be able to see how single molecules of DNA interact with other biomolecules.

DNA cords
But at present, the method only works with "cords" of DNA made up of six molecules wrapped around an seventh acting as a core. That's because the electron energies are high enough to break up a single DNA molecule.

Using more sensitive detectors that can respond to lower-energy electrons should soon allow the team to see individual double helices, and even unwound single strands of DNA. "With improved sample preparation and better imaging resolution, we could directly observe DNA at the level of single bases," says di Fabrizio.

Earlier this year a University College London team led by Bart Hoogenboom felt their way along individual strands of DNA using the Braille-like technique of atomic-force microscopy ( Like the Italian team, they were able to detect the twisting groove that separates the twin strands of the double helix.

Journal reference: Nanoletters,

Soft robots and the origins of life

ORIGINAL: The Economist

George Whitesides, head of the Whitesides Research Group at Harvard University, builds robots that move like octopuses and investigates the chemical beginnings of life

ORIGINAL: Science Video Portal
Soft Machines Get Camouflaged
S. A. Morin et al.

Many creatures utilize ornate colors and patterns as a means of camouflaging and in some cases standing out against their environments—but this adaptive camouflage has rarely been mimicked in synthetic systems. Through the use of circulating colored fluids and motion-inducing pneumatic pressurization, Morin et al. demonstrate variable camouflage and display in soft, flexible, mobile machines.

Chemiluminescent soft robotics.

A True Elite Education at Half the Price

Leigh Buchanan | Inc. magazine
Oct 30, 2012

The Minerva Project has a plan to take online education to the next level.
Illustration by Brett Ryder
Add caption
Illustration by Lauren Tamaki
You'll get no brownie points for how good an athlete you are, for how much money your parents can donate. Ben Nelson, CEO of the Minerva Project

There may be no brand more venerable than the Ivy League. Individually and together, its eight members connote the pinnacle of scholarship. No university has emerged to challenge its intellectual supremacy in more than a century. On that timeline, Caltech, founded in 1891, is a start-up.

But now there is the Minerva Project. Ben Nelson, former CEO of the online photo service Snapfish, is building a school he asserts will be more rigorous than Harvard or Yale. "It will be harder to get into Minerva than any other university," says Nelson. "You'll have the same criteria for your grades, essay, and application. But you'll get no brownie points for how good an athlete you are, for how much money your parents can donate, or for what state you were born in." While Nelson is raising the floor established by elite universities in terms of who qualifies for admission, he is also raising the ceiling in terms of how many to admit. Like virtually every other higher-education start-up, Minerva, based in San Francisco, will live online. That means Nelson can swing wide his doors to tens of thousands of top-drawer students, many of them international. "Harvard allows 2,000 students into the admission cycle, of whom 200 are not American," says Nelson. "Clearly, that's not a good representation of the smartest people in the world."

The company, a for-profit, expects to admit its first class of several hundred in the fall of 2014 or 2015. Tuition will cost less than $20,000--half the price of the Ivy League. In April, Benchmark Capital invested $25 million, the largest seed round in its history. "The idea of giving kids a world-class, credentialed education is the most ambitious goal we've seen in this space," says Kevin Harvey, a Benchmark general partner.

Minerva isn't Nelson's first stab at transforming education. Twenty years ago, at the University of Pennsylvania, he enrolled in a class about the history of universities. "I studied Penn and Franklin and Hopkins," says Nelson. "Then I looked around and said, 'This is not what it's supposed to be.'?" His chief criticism: Schools were training people to be successful but not to become the kind of leaders who could move the world forward. So he joined the student government and spent the next four years loudly advocating for change.

Post-Snapfish, Nelson thought again about education reform. He still wanted to improve elite education, but his more pressing concern was to expand it. Since Nelson's graduation, top schools had adopted needs-blind admission policies, and students around the world increasingly coveted a U.S. education. The result was far more demand from worthy students than the Ivies and their prestigious brethren could handle. "Admissions officers at elite universities will tell you that they could take everyone they've accepted, reject them, then accept the next tier 10 times over and not be able to tell the difference in quality," says Nelson.

Minerva will be global in more than its student body. Nelson plans to establish dormitory clusters in cities around the world. After their freshman years, students will be strongly encouraged to spend each semester in a different location. Students unable to participate in this movable feast must demonstrate proficiency in three languages to graduate.

Minerva's curricular innovations emerge from a distinction Nelson draws between knowledge dissemination and intellectual development. Knowledge, he maintains, is free and ubiquitous on the Internet, with nonprofits like Khan Academy and schools like Stanford posting thousands of lectures and lessons. So Minerva will offer no introductory classes. Rather, students are expected to master the basics of every subject on their own. During their freshman year, all students will follow the same core curriculum focused on subjects including multimodal communications and complex-systems analysis. That foundation laid, every subsequent course can be taught at a very high level. "If you were to look at sophomore-junior-senior years at Minerva, they will be equivalent to junior-senior-and-master's years at most other elite universities," says Nelson.

He is also upending the pedagogic convention whereby tenured faculty deliver weekly lectures, followed by discussion sections presided over by beleaguered grad students. The school will bestow Minerva Prizes--characterized by Nelson as Nobel awards for teaching--on star academics at top universities. Prizewinners will "curate" classes for Minerva. That will entail creating original course materials; the professors can also invite their respected peers to contribute specialized expertise. Classes will gather online to view and discuss the material, overseen by the full-time faculty--all of whom will be Ph.D.'s or the equivalent and all of whom will receive both salaries and stock options.

Nelson's vision has already resonated at the highest levels of traditional academe. Former Harvard president and Treasury Secretary Larry Summers offered to chair Minerva's advisory board after a single meeting with its founder. Another adviser is Bob Kerrey, a former U.S. senator, Nebraska governor, and president of the New School. "What he's got is one of the best private-education ideas I've ever heard," says Kerrey. "I think he's going to be successful, and as a consequence, university presidents across the country are going to be able to say to their boards and their faculties, 'We have to change.' He's going to have a very, very positive impact on all of higher education in America."

For Nelson, that impact will be measured by how many brilliant students he can endow with what he calls the Minerva brain and establish in roles in which they can make a difference. Toward that end, he is creating a department to help graduates raise money and make connections for new businesses and other projects. The department will also perform many functions of a traditional publicist--promoting the accomplishments of alumni so alumni can concentrate on their actual work. "We want to create an ethos where what's rewarded is doing as opposed to self-promotion," says Nelson. "It's the difference between graduating people who are focused on themselves and graduating people who are focused on moving the world forward."

Leigh Buchanan is an editor at large for Inc. magazine. A former editor at Harvard Business Review and founding editor of WebMaster magazine, she writes regular columns on leadership and workplace culture. @LeighEBuchanan

martes, 27 de noviembre de 2012

Quantum Dots Make Artificial Photosynthesis Last Longer

ORIGINAL: Tech Review
November 8, 2012

Nanoparticles offer a solution to a key problem with splitting water with sunlight to generate hydrogen.

Why It Matters
Artificial photosynthesis—splitting water with energy from sunlight—could provide a way to harness and store power from the sun and provide carbon-free fuel for cars.

Hydrogen generator: Researchers used this setup to measure hydrogen production facilitated by novel nanoparticles.
Using the energy in sunlight together with water and air to make fuel—artificial photosynthesis—is a little closer thanks to an advance involving nanoscale crystals known as quantum dots.

Researchers have been working on artificial photosynthesis for many years (see “Sun + Water = Fuel”). One approach involves using particles that combine light-absorbing materials with catalysts that can split water. But the light-absorbing materials tend to deteriorate quickly in sunlight, rendering the approach impractical.

In the latest issue of the journal Science, researchers from the University of Rochester show that quantum dots not only absorb the light but also are far more durable than previous light-absorbing materials. The new approach also has the advantage of not requiring any precious metals, so it might be relatively cheap.

The new approach doesn’t solve all of the challenges with artificial photosynthesis. The proof-of-concept system developed by the Rochester team does only half of the water-splitting reaction—that is, it makes hydrogen, but not oxygen. What’s more, particle-based approaches like this one generate both hydrogen and oxygen in one container, and there’s a danger that they will interact and explode. Alternate approaches to photosynthesis that generate hydrogen and oxygen in separate containers are safer.

The remaining difficulties point to the need for efforts like the Department of Energy Innovation Hub at Caltech. The hub is designed to evaluate advances like this one in light of how they might work in a complete artificial photosynthesis system—and if such approaches look workable, to build and test prototype systems (see “Artificial Photosynthesis Effort Takes Root”).

Caminando Colombia

ORIGINAL: Vanguardia
24 de Noviembre de 2012

Caminando Colombia
Se realizó en Colombia en el lanzamiento oficial del segundo y más completo resumen de lo que para Andrés Hurtado García, catalogado por muchos como el mejor fotógrafo de nuestro país, significa ser colombiano.

Con la natural expectativa de que el nuevo libro del maestro Andrés Hurtado García no solo colme la satisfacción de mirar a Colombia en el natural espejo de sus paisajes, de sus ríos, lagunas, valles, montañas, páramos, cañones, playas y playones, sino que reviva el verdadero nacionalismo que trasciende las banderas y los discursos políticos, Villegas Editores hizo el lanzamiento oficial del segundo y, seguro, el más completo resumen de lo que para el mejor fotógrafo de nuestro país significa ser colombiano.

Y para los que no lo tenemos aún en nuestras manos, pues debemos partir de imaginarlo a partir de su título, arriesgado, por cierto: Caminando Colombia.

Arriesgado y recursivo cuando acude a una de las formas gramaticales más complejas de usar, el gerundio. Una variación expositiva que de tajo elimina el tiempo en que sucedió la acción (tácitamente deja entrever que es un proceso de muchos años tirando literalmente pata por el territorio nacional). Elimina igualmente la posibilidad de saber si se caminó solo o en compañía, como lo sugieren los cánones del caminante, y, en consecuencia, no queda más que dejar que la flecha apunte hacia un solo lado, el sujeto directo de la acción: Colombia.

Y para los que no lo tenemos aún en nuestras manos, pues debemos partir de imaginarlo a partir de su título, arriesgado, por cierto: Caminando Colombia

Caminando Santander
Andrés Hurtado García es un hermano lasallista de origen caldense, doctor en lingüística y fotógrafo por amor, pasión y convicción. Presentación que sonaría odiosa en la sencillez y la timidez que lo caracterizan, pero necesaria a la hora de querer subrayar la importancia de lo que sus palabras refrendan cuando hace referencia a Santander: “Mi recorrido por todos los rincones de Colombia me ha llevado a declarar a Santander como el departamento más completo: en la lista de valores que me he inventado para catalogar los departamentos, Santander ocupa indudablemente el primer lugar. Tres son los factores que exijo: pueblos hermosos, bellezas naturales e identidad histórica asumida. Santander tiene, en efecto, los pueblos más bellos de Colombia. ¿Quién se atrevería a negarlo? Barichara es la cumbre de la belleza de los pueblos del país. Bellezas naturales indiscutibles y únicas: el Cañón de Chicamocha con sus pueblos y los “barrigones”, los árboles más bellos del país; las cavernas, el impresionante Páramo de Santurbán, estrella fluvial del oriente colombiano. Y, para terminar, la identidad histórica asumida; el peso de la historia de los Comuneros se siente, vibra en las “bravas tierras de Santander” y en sus gentes.

El más fiel de sus compañeros de caminos en Santander es el abogado, caminante, buzo y fotógrafo Jorge William Sánchez Latorre, justamente llamado “el guardián de Santurban” por su posición férrea en defensa de este recurso natural de los colombianos. Sobre su amistad con Andrés Hurtado, resalta: “Invité a Andrés una vez a recorrer el páramo, y con esa vez fue suficiente para que regresara en cuatro oportunidades a Santurbán y en tres al Cañón del Chicamocha, y quedó tan claramente impregnado de estos lugares, que incluso hemos pasado un 31 de diciembre acampando al lado de la laguna La Pintada en el corazón del Santurbán y una Navidad compartida con la comunidad de la vereda El Embudo, en el sitio donde confluyen los ríos Guaca y Chicamocha, en lo más profundo del cañón”.

Un regalo que todo colombiano debe darse, y que todo santandereano debería tener por el solo hecho de saber que la mirada sensible de este artista de la lente tiene sus teles y gran angulares apuntando en dirección oriente, hacia la luz que se multiplica en el crisol mágico de las montañas del Chicamocha, en el romántico encuentro de la piedra y el cielo de Barichara, o el respetable silencio gélido del amenazado Páramo de Santurbán.

Colombia Secreta. Villegas Editores
Vivir en carpa, inventar caminos; soñar inmensidades, atisbar y ganar lejanos horizontes; huir del destino de los sedentarios, amar por encima de todo la suprema libertad de los nómadas "¡He aquí la vida!”.

Este es un libro muy especial sobre una Colombia escondida, sobre un país que difícilmente hemos llegado a soñar. Su autor, Andrés Hurtado García, combina la docencia, el montañismo y la práctica del periodismo en el diario más importante del país, con una profunda devoción por la fotografía, un oficio que domina con hábil maestría. Este incomparable documento nos revela en bellas imágenes y deliciosas anécdotas 

los lugares más hermosos de la geografía colombiana que el autor ha descifrado a lo largo de 15 años de infatigables recorridos por sus costas, montañas, valles, llanos, volcanes, ríos, lagos y lagunas, así como por la tupida y generosa selva amazónica. Un libro obligatorio sobre el que podría ser el país más bello del mundo.

Andrés Hurtado García, docente colombiano, profundamente espiritual, que además de hombre culto es un caminante nato, un nómada aventurero de lugares y caminos, escalador de alturas impensadas, navegador confiado de ríos y corrientes.

Disponible en inglés con el título:
Unseen Colombia
Memoria de diseño
Colombia Secreta. Villegas Editores
Colombia Secreta. Villegas Editores

lunes, 26 de noviembre de 2012

Giving graphene the bends makes it transistor-ready

ORIGINAL: New Scientist
23 November 2012

Transistor-ready (Image: Alfred Pasieka/Getty)
Sometimes bending something destroys it, but graphene grown on a rippling surface develops the semiconducting properties required for it to act as a transistor. The technique could be what's needed for the wonder material to finally replace silicon as the bedrock of computing.

Graphene is a sheet of carbon just one atom thick, with the atoms arranged in a hexagonal grid, like chicken wire. As well as being thin, super-strong and very flexible, this structure allows electrons to zip through at high speeds. It therefore seems poised to become the basis for ultra-fast computers.

But there's a problem. Materials used to make transistors have to be able to switch current on and off to create logic circuits. This switchability depends on there being a difference, known as a band gap, between the energy possessed by the material's free electrons, and the energy they would need to move around and conduct electricity. Only applying the right amount of external energy allows electrons to jump the band gap to become conducting.

Semiconductors like silicon have band gaps, making for good transistors. But because of its natural conductivity, graphene has a band gap of zero – making it unsuitable for transistors.

Nanoribbon solution
Various solutions have been proposed for turning graphene into a semiconductor, including adding an insulating layer between two layers of graphene to reduce its conductivity, or carving it into very narrow ribbons, which alters its structure, making it easier to turn current off.

However, both of these use conventional etching techniques, placing limits on just how small such graphene transistors could get. For example, creating ribbons any less than 10 nanometres wide has until now left them with edges so ragged that the band gap disappears.

Now Ed Conrad at the Georgia Institute of Technology in Atlanta and colleagues have found a way to create much narrower nanoribbons, without destroying their semiconductor capabilities, in a much simpler way.

The trick was to grow graphene sheets on a rippling surface covered in parallel trenches, each 18 nanometres deep. The team found that where the surface of the sheet dipped into a trench, the graphene's properties became semiconducting, with a band gap of 0.5 electronvolts, rather like the nanoribbons. Crucially, however, these strips of semiconductor were just 1.5 nanometres wide and sleek, not ragged.

Silicon replacement?
"The results are very important, because the existence of a band gap makes it possible to use graphene in nanoelectronics," says Luis Brey at the Materials Science Institute in Madrid, Spain. But the reason the gap exists is not yet clear. "More theoretical work is needed in order to understand how a 0.5 electronvolt gap appears in this structure," he says.

Chris Howard at University College London calls the work a strong development that opens up many potential applications, including high-performance electronics.

Silicon won't be replaced just yet, adds Conrad. "But graphene could push Moore's law to its limits."

Journal reference: Nature Physics, DOI: 10.1038/nphys2487