Fossil Free: Microbe Helps Convert Solar Power to Liquid Fuel

By pairing biology and photovoltaics, a new "electrofuel" system could build alternative fuels

Source: Scientific American

Author: David Biello 

Link: http://www.scientificamerican.com/article.cfm?id=microbe-uses-solar-electricity-to-build-liquid-fuel#comments

Key Words: Energia e sustentabilidade; Engenharia Genética; Microorganismos; Monera; Bactérias.

ELECTROFUEL: This novel bioreactor uses the electricity from a photovoltaic panel to help a microbe build CO2 into a liquid fuel.Image: Courtesy of Han Li

A new "bioreactor" could store electricity as liquid fuel with the help of a genetically engineered microbe and copious carbon dioxide. The idea—dubbed "electrofuels" by a federal agency funding the research—could offer electricity storage that would have the energy density of fuels such as gasoline. If it works, the hybrid bioelectric system would also offer a more efficient way of turning sunlight to fuel than growing plants and converting them into biofuel.

"The method provides a way to store electrical energy in a form that can be readily used as a transportation fuel," chemical engineer James Liao of the University of California, Los Angeles, explains. Liao and his colleagues report on their "integrated electro-microbial bioreactor" in Science on March 30.

To convert electricity into liquid fuel, Liao and his colleagues focused on Ralstonia eutropha, a soil microbe that can use hydrogen as an energy source to build CO2 into more microbial growth. Already, the microbe's biological machinery is being harnessed for industrial purposes—for example, to churn out plastic instead of proteins. By tweaking the industrial microorganism's genetics, the team now has coaxed it to churn out various butanols—a liquid fuel. "If one speaks with combustion engineers, then they will tell you that the simplest real fuel is butanol," says chemist Andrew Bocarsly of Princeton University, who is not involved in the electrofuel project.

Liao's bioreactor gets its electricity from a solar panel. The current flows into an electrode in the bioreactor, which is full of water, CO2 and R. eutropha. The electricity starts a chemical reaction that uses the CO2 to make formate—carbon dioxide with a hydrogen atom attached, which is an ion (electrically charged) that substitutes for insoluble hydrogen as an energy source for the microbe. The genetically engineered R. eutropha then consumes the formate, yielding butanols, plus more CO2 as a waste product—the latter of which is recycled back through the biochemical process.

R. eutropha doesn't particularly like to be shocked, however, so Liao's team built a "porous ceramic cup" to shield the microbe from the electrical current. Powered by its photovoltaic panel, the bioreactor produced 140 milligrams per liter of butanol fuel over 80 hours, although it then stopped working. "In principle, we can use the same approach to produce other kinds of fuels or chemicals," Liao says.

The approach combines the appeal of energy-dense liquid fuels—packing 50-times or more the energy per kilogram of even the best batteries—with the potential to produce more fuel in a limited area than plants. Photosynthesis achieves the same thing, absorbing sunlight and storing its energy in the bonds of carbohydrate molecules—otherwise known as food and, nowadays, fuel. But photosynthesis is inefficient. For example, corn converted to ethanol captures less than 0.2 percent of the original energy in the sunlight as fuel. A photovoltaic cell can convert 15 percent of incoming photons into electricity, but such solar electricity is hard to store. Using solar power in an electrofuel bioreactor such as Liao's could theoretically convert as much as 9 percent of the incoming sunlight into the final and storable fuel. "By combining a man-made device, which has a great potential for improvement, with biological CO2 fixation, we get the best of both worlds," Liao argues, although that kind of efficiency has yet to be demonstrated. Even this demonstration process turns more sunlight into liquid fuel, however, than biofuels such as corn ethanol or even photosynthetic microbes genetically altered to make butanols. Plus, Liao adds, "it is possible toincrease the productivity much higher, since Ralstonia is an industrial microorganism."

Comentário: Hum...interessante. Mas tenho lá minhas dúvidas de quando essas bactérias estiverem fora de controle, ou seja, soltas no ambiente. Ainda acho que a energia solar é a maior, mais limpa, mais segura e mais justa fonte de energia.

ONU pede ação internacional urgente para combater desigualdades sociais e riscos ambientais

Fonte: ONUBrasil

http://www.onu.org.br/onu-pede-acao-internacional-urgente-para-combater-desigualdades-sociais-e-riscos-ambientais/

ASSUNTO: Recursos naturais - Desigualdade Social - Risco Ambiental - Socioembiental.

Justiça social e proteção ambiental são igualmente urgentes e intrinsecamente ligadas a objetivos universais, necessitando de ação global coordenada nas duas frentes na Conferência das Nações Unidas sobre Desenvolvimento Sustentável (Rio+20), em junho. Esta argumentação, baseada no relatório “Sustentabilidade e Equidade: Um futuro melhor para todos”, propicia a discussão do Fórum Global para o Desenvolvimento Humano (22 e 23/03). O evento em Istambul, na Turquia, vai analisar os críticos desafios sociais, econômicos e ambientais que o mundo enfrenta atualmente, incluindo melhores abordagens para avaliar o progresso nacional e global.

“O mundo está numa encruzilhada”, afirmou o Secretário-Geral da ONU, Ban Ki-moon, em mensagem. “Precisamos de todos, ministros, parlamentares, empresários, líderes da sociedade civil e jovens para, juntos, transformar nossas economias, colocar nossas sociedades numa posição mais justa e equitativa, e para proteger os recursos e ecossistemas dos quais nosso futuro compartilhado depende.”

“O conceito de desenvolvimento humano originou da insatisfação bem fundamentada no uso exclusivo do produto interno bruto como uma medida de progresso humano”, destacou Ban. “Apesar deste entendimento ter se tornado uma espécie de referência em nosso pensamento sobre desenvolvimento, ainda há necessidade de mudança dramática na forma de valorizar e medir o progresso.”

“O desenvolvimento sustentável reconhece que nossos objetivos econômicos, sociais e ambientais não são concorrentes que devem ser colocados uns contra os outros, mas são objetivos interligados, mais efetivos quando perseguidos juntos e de maneira holística”, disse o Secretário-Geral. “Precisamos de um documento final na Rio+20 que reflita este entendimento e que relacione as preocupações de todos.”

Segundo a Administradora Adjunta do Programa das Nações Unidas para o Desenvolvimento (PNUD), Rebeca Grynspan, o Fórum “oferece uma oportunidade única para debater as mensagens que queremos levar para o Brasil, refletindo sobre o que aprendemos desde a Conferência de Estocolmo em 1972 e da Cúpula dos Povos em 1992.”

“Devemos reconhecer que alto carbono e o crescimento desigual são por si prejudiciais ao reproduzir instabilidade social e violência e destruir habitats naturais críticos para subsistência. Precisamos de um novo paradigma de crescimento e uma nova abordagem para a economia política de desenvolvimento sustentável”, acrescentou Grynspan na abertura do evento.

Políticos de diversos países farão intervenções. Para amanhã está prevista a palestra do Senador e ex-Ministro da Educação do Brasil Cristovam Buarque. Para acessar a programação,clique aqui.

O Fórum, organizado pelo PNUD e pela Turquia, com apoio da Dinamarca, será concluído com uma “Declaração de Istambul”, articulando as propostas conjuntas dos participantes e prioridades para a Rio+20.

The Ballooning Brain: Defective Genes May Explain Uncontrolled Brain Growth in Autism

Autistic children's brains may grow too big, too soon. A new study links this unusual growth to abnormal gene activity that fails to prune unnecessary neural connections

Source: Scientific American

http://www.scientificamerican.com/article.cfm?id=courchesne-gene-expression

By Ferris Jabr

BOUNTIFUL BRAINS: Eric Courchesne's studies suggest that autistic brains brim with too many neurons for their own good.Image: FR86, iStockphoto

As a baby grows inside the womb, its brain does not simply expand like a dehydrated sponge dropped in water. Early brain development is an elaborate procession. Every minute some 250,000 neurons bloom, squirming past one another like so many schoolchildren rushing to their seats at the sound of the bell. Each neuron grows a long root at one end and a crown of branches at the other, linking itself to fellow cells near and far. By the end of the second trimester, neurons in the baby's brain have formed trillions of connections, many of which will not survive into adulthood—the least traveled paths will eventually wither.

Sometimes, the developing brain blunders, resulting in "neuro-developmental disorders," such as autism. But exactly why or how early cellular mistakes cause autism has eluded medical science. Now, Eric Courchesneof the University of California, San Diego, thinks he has linked atypical gene activity to excessive growth in the autistic brain. With the new data, he has started to trace a cascade of genetic and cellular changes that he thinks define autism. Although intrigued by Courchesne's work, other researchers caution that explosive neural growth is not necessarily a defining feature of all autistic brains.

Since 1998 Courchesne has been searching autistic brains for unusual structural features. His studies suggest that while in the womb, the autistic brain sprouts an excess of neurons and continues to balloon during the first five years of life, as all those extra neurons grow larger and form connections. Sometime after age four or five, Courchesne has also found, autistic brains actually start to lose neural connections, faster than typical brains.

In a study published November 2011 in JAMA, The Journal of the American Medical Association, Courchesne reported that children with autism have 67 percent more neurons in their prefrontal cortex (PFC) than typical children. Located in the area of the brain just behind the eyes, the PFC is responsible for what psychologists call "executive functions"—high-level thinking, such as planning ahead, inhibiting impulses and directing attention. In his 2011 study Courchesne sliced up brain tissue from six autistic children and seven typical children who had passed away and counted the number of cell bodies in the sections to estimate the total number of neurons in their PFCs.

Now, Courchesne and his colleagues have analyzed DNA and RNA in 33 cubes of brain tissue from people who passed away, 15 of whom were autistic (nine children and six adults) and 18 who had typical brains (seven children and 11 adults). Looking at the order of DNA's building blocks reveals whether individual genes have mutations; measuring levels of RNA indicates how often those genes were translated into proteins. Such gene expression, Courchesne and his colleagues found, varied between autistic and typical brains. In brain tissue from both autistic children and autistic adults, genes coding for proteins that identify and repair mistakes in DNA were expressed at unusually low levels. Additionally, all autistic brains demonstrated unusual activity levels for genes that determine when neurons grow and die and how newborn neurons migrate during early development. Some genes involved in immune responses, cell-to-cell communication and tissue repair, however, were expressed at unusual levels in adult autistic brains, but not in autistic children's brains. The results appear in the March 22 issue of PLoS Genetics.

By combining his new findings with his earlier discoveries, Courchesne has started to construct a kind of timeline of autism in the brain. Perhaps, as the brain of a future autistic child develops in the womb, something—an inherited mutation or an environmental factor like a virus, toxin or hormone—muffles the expression of genes coding for proteins that usually fix mistakes in sequences of DNA. Errors accumulate. The genetic systems controlling the growth of new neurons go haywire, and brain cells divide much more frequently than usual, accounting for the excess neurons found in the PFC of autistic children. Between birth and age five, the extra neurons in the autistic brain grow physically larger and form more connections than in a typical child's brain. Unused connections are not pruned away as they should be. Later, in adolescence and adulthood, the immune system reacts against the brain's overzealous growth, which might explain the unusual levels of immune genes Courchesne found in his new study and why, in earlier work, he had discovered that when autistic children become teenagers, some brain regions actually start shrinking compared with typical brains.

Not all researchers, however, accept that the patterns of brain growth Courchesne has discovered are relevant to everyone with autism. Nicholas Lange, a biostatistician in the psychiatry department at Harvard Medical School, says that Courchesne analyzed too few samples in his new study to generalize the results to the larger autistic community. Some researchers have surfaced evidence that around 15 percent of autistic children have smaller than usual heads, a condition known as microcephaly, which indicates an abnormally small brain. David Amaral of the University of California, Davis, has previously told reporters that in an unpublished neuroimaging study, he found that only about 11 of 114 autistic children had unusually large brains. Other researchers point out that, in his research with tissue samples from brain banks, Courchesne fails to compare the number of neurons in the cerebral cortex with other parts of the brain—it remains unclear why only the PFC would explode in growth.

But acquiring enough preserved tissue from brain banks to conduct meaningful studies is no easy task—they are incredibly coveted resources, and Courchesne's new study relies on a respectable sample. Looking at gene expression in postmortem brain tissue offers insights into the biology of autism that neuroimaging studies and analysis of DNA and RNA in blood cannot provide because different cell types express different sets of genes. Courchesne's newest findings at least partially echo earlier research byDaniel Geschwind of the University of California, Los Angeles, who also linked autism to unusual activity of genes that control immune responses and how neurons organize themselves in the developing brain. Although Courchesne's concept of autistic brain development is far from flawless or complete, it remains one of the most cohesive theories offered so far—one that suggests the possibility of treatment as well. If scientists definitively link autism to a characteristic sequence of changes in gene expression and unusual neural growth, then it becomes possible to target and reverse any one of the thousands of steps in that sequence.

"Each individual autistic person likely has their own specific profile of dysregulated [sic] genes," Courchesne says, "which means that autism is a very complicated problem. But it's now knowable. We are getting at core knowledge. If we confirm that the starting point is gene activity, we can do something about it, because gene activity can be modified."

Comentário: Embora ainda estejamos muito aquém do diagnóstico pré-natal. Devemos considerar que com esta notícia surge uma luz no fundo do túnel. Até pouco tempo não tínhamos claro o que acontecia com os portadores desta síndrome. Apenas suposições. Agora a estrutura neuronal aponta diferenças. Já é um caminho a ser percorrido.  

Cientistas clonam primeira cabra que produz lã de alta qualidade

Fonte: Folha.com - Ciências
Link: http://www1.folha.uol.com.br/ciencia/1061982-cientistas-clonam-primeira-cabra-que-produz-la-de-alta-qualidade.shtml

ASSUNTO: Genética - clonagem

Cientistas clonaram com sucesso pela primeira vez uma cabra que produz a lã de alta qualidade pashmina, muito apreciada para a confecção de roupas e acessórios.

Batizada de Noori, a fêmea nasceu saudável no dia 9 de março em no laboratório da Caxemira, na Índia.

	Dar Yasin/Associated Press
	A cabra clonada Noori é clicada com sua "mãe de aluguel" em centro de pesquisa na Índia

De acordo com uma nota, o embrião foi implantado e se desenvolveu no útero de uma outra fêmea, que funcionou como uma "mãe de aluguel". A técnica levou dois anos para ser padronizada com sucesso.

Famosa pela lã, a Capra hircus é encontrada na natureza na região do Himalaia.

Cientistas acham nova espécie de anfíbio em estádio do Bronx

Fonte: Folha.com - Ciências

Link: http://www1.folha.uol.com.br/ciencia/1062310-cientistas-acham-nova-especie-de-anfibio-em-estadio-do-bronx.shtml

ASSUNTO: Taxonomia - Diversidade Biológica - Anfíbios - Anuro

O estádio de beisebol Yankee, no bairro nova-iorquino do Bronx, serviu de moradia para uma nova espécie de sapo que só agora foi reconhecida cientificamente.

"Isso mostra que há ainda novas e importantes espécies esperando para serem descobertas nas grandes cidades norte-americanas", comentou o biólogo Brad Shaffer, da UCLA (Universidade da Califórnia), que não fez parte da identificação do anfíbio.

O animal poderia ter vivido em locais com mais verde que estão próximos a Nova York, mas escolheu viver em um dos pontos turísticos e esportivos mais conhecidos da cidade.

	Brian Curry/Associated Press
	A nova espécie de sapo encontrada por pesquisadores americanos no bairro do Bronx, em Nova York

A bióloga Cathy Newman, da Universidade Estadual da Louisiana, é a autora principal do estudo, publicado na revista "Molecular Phylogenetics and Evolution".

Ela conta que foi procurada pela colega Jeremy Feinberg, da Universidade Rutgers, para tratar de sapos que pareciam ser diferentes.

Uma das primeiras pistas de que seria uma nova espécie foi o coaxar diferenciado. Não se parecia como o de um sapo-leopardo: o som emitido era mais curto do que o prolongado típico dessa espécie. A confirmação veio depois com uma análise comparativa com o DNA.

"Eu estava esperando encontrar um dos sapos-leonardo [há os dos noroeste e sudoeste na área] que, por alguma razão, tinha um comportamento atípico ou que fosse um híbrido", disse Newman.

"Foi realmente uma surpresa uma vez que obtivemos dados que sugeriam fortemente que [o anfíbio] era uma nova espécie. É fascinante em uma área pesadamente urbanizada [como aquela]."

O nome do bicho ainda não foi escolhido.

Worm Discovery Illuminates How Our Brains Might Have Evolved

Genetic traces similar to those in vertebrate brains have been found in lowly worms, but not all scientists are convinced that complex brains were already in the works more than 500 million years ago

ASSUNTO: Evolução - Nematelmintos - Desenvolvimento do Cérebro

Source: Scientific American

Link: http://www.scientificamerican.com/article.cfm?id=worm-discovery-brain-evolution

By Katherine Harmon  | March 15, 2012

HUMBLE BEGINNINGS OF THE BRAIN?:New research suggests that the genetic blueprints for our big brains might be present in this simple acorn worm. But not all invertebrate researchers agree.Image: Ariel Pani

Our earliest invertebrate ancestors did not have brains. Yet, over hundreds of millions of years, we and other vertebrates have developed amazingly complicated mental machinery. "It must have evolutionary rootssomewhere, but where?" wrote Henry Gee, an editor at Nature, in an essay published in the journal's March 15 issue. (Scientific American is part of Nature Publishing Group.)

Years of study of common invertebrate lab subjects, such as amphioxus (Branchiostoma lanceolatum) or nematodes, have yielded scant evidence as to the origins of the big, centralized brains we all develop as embryos. Until, that is, researchers turned their gaze to the humble acorn worm (Saccoglossus kowaleskii).

These unlovely, simple little worms live most of their brainless lives buried in deep-sea beds. Researchers have probed the genetic patterns of their developing larvae and think they might have discovered a set of signals similar to the ones we use to build our central nervous system. The findings are reported online in the same issue ofNature.

But not everyone in the invertebrate community is convinced that the early antecedent to the vertebrate brain has been discovered. And these little worms seem to be stirring up controversy in the quest to find the beginnings of our own brains.

Complexity from simplicity

All of our features—from our brains to our bones—emerged from elaboration on the simplest of genetic patterns found in primitive gunk. But scientists have been keen to find out just how far back they can trace key developments, such as the signals that spurred our central nervous system to develop.

"The vertebrate brain is really exquisitely complex and elaborate," says Ariel Pani, a graduate researcher at Stanford University and co-author of the new paper. The brain is prompted into being during development by a long chain of genetically determined signals. "There are particular developmental processes in vertebrates that seem to be absent in other species"—or at least those that have been most commonly studied, such as the amphioxus, Pani notes. Thus, many scientists had presumed that these genetic tools had only emerged with the vertebrate line itself.

That is where members of the hemichordate group, such as S. kowaleskii, can broaden the view into our joint invertebrate past. The last common ancestor this worm had with vertebrates probably lived more than 500 million years ago. So is it possible that this ancient ancestor already contained the genetic groundwork for big brains—and that this ability has since been lost in more common invertebrate subjects?

Lean foundations

The path from a few cells to a full brain has taken hundreds of millions of years in evolutionary time. But during embryonic development, the elaborate process takes just days or months. During an animal's embryonic phase, clusters of proteins—called signaling centers—help spur the creation of different parts of the body. Three major signaling areas in vertebrates—the anterior neural ridge, the zona limitans intrathalamica and the isthmic organizer—are responsible for starting off the major divisions within the central nervous system, such as separating the mid and hind parts of the brain.