Con olor a Geosmina @joshinthelab - Tumblr Blog

Image of the Week - July 11, 2016

CIL:38954 - http://www.cellimagelibrary.org/images/38954

Description: A confocal micrograph of stained and autofluorescent cells of xylem in the stem of buttercup (Ranunculus), showing xylem vessels whose walls are studded with pits that allow passage of water from one vessel to another.

Author: Jim Haseloff

Licensing: Attribution-NonCommercial-NoDerivs 2.0 UK: England & Wales (CC BY-NC-ND 2.0 UK)

infinity-imagined

A helical TALE protein molecule wrapped around a double helix of DNA. TALE stands for “Transcription Activator-Like Effectors”, they are produced by Xanthomonas bacteria when entering a plant cell. They manipulate the host cell by switching on certain genes that make the plant cell more susceptible to infection. TALE subunits bind to the nucleotides of DNA in a 1:1 ratio, and each subunit has a pair of amino acids that is specific to a single DNA base. This enables the TALEs to recognize and activate specific sequences of DNA.

Animation rendered from PDB file 3UGM with qutemol.

themedicalstate

How the Brain Builds Memory Chains

Recollections of successive events physically entangle each other when brain cells store them

Think about the first time you met your college roommate. You were probably nervous, talking a little too loudly and laughing a little too heartily. What else does that memory bring to mind? The lunch you shared later? The dorm mates you met that night? Memories beget memories, and as soon as you think of one, you think of more. Now neuroscientists are starting to figure out why.

When two events happen in short succession, they feel somehow linked to each other. It turns out that apparent link has a physical manifestation in our brains, as researchers from the Hospital for Sick Children in Toronto (SickKids), the University of Toronto and Stanford University describe in Science. “Intuitively we know that there’s a structure to our memory,” says neuroscientist Paul Frankland, affiliated with both the University of Toronto and SickKids. “These experiments are starting to scratch the surface of how memories are linked in the brain.”

In your brain, and in the brains of lab mice, recollections are physically represented as collections of neurons with strengthened connections to one another. These clusters of connected cells are known as engrams, or memory traces. When a mouse receives a light shock to the foot in a particular cage, an engram forms to encode the memory of that event. Once that memory forms the set of neurons that make up the engram are more likely to fire. Furthermore, more excitable neurons—that is, brain cells that activate easily—are more likely to be recruited into an engram, so if you increase the excitability of particular neurons, you can preferentially include them in a new engram.

The question was, did that principle apply to two memories that happen close together in time? Neurons in a newly formed memory trace are subsequently more excitable than neighboring brain cells for a transient period of time. It follows then that a memory formed soon after the first might be encoded in an overlapping population of neurons, which is exactly what Frankland and study co-lead author Sheena Josselyn, found.

Mice who formed a fear memory—one where they were given a foot shock in a particular environment—and then formed a second memory six hours later had formed those two memories in overlapping engrams. The rodents who formed the same memories 24 hours apart had separate sets of neurons related to each memory.

Josselyn, a neuroscientist at SickKids and the University of Toronto, and Frankland’s group was also able to tinker with the link between two memories by adjusting the excitability of neurons during different time points. Mice should normally form separate memories when events happen 24 hours apart, but when the researchers re-excited the neurons in the first memory engram while the second memory was forming, they could artificially link those experiences.

When they tried to disentangle memories that happened six hours apart, however, they ran into trouble. Decreasing the excitability of the neurons in the first memory during the second event seemed to prevent the second memory from forming. “We were blown away by that,” Josselyn says. In these types of experiments, she explains, they are only ever manipulating about 10 percent of the neurons in the amygdala. If this second memory cannot form, however, that implies something is changing in the other 90 percent of neurons. Their findings mean that neurons are competing to be included in the new engram, and in this competition excitability rules. That 10 percent of neurons are the winners because they inhibit the other 90 percent—it is winner take all.

Being able to look inside a brain at this level of specificity is wholly novel, says neuroscientist Steve Ramirez at Harvard University who was not involved in the new study. “It’s the kind of research that literally 10 years ago it would have been just bananas to think that we could go in and find these memories,” he says. “The future of this research is to get a blueprint of how memory works.”

Although the researchers could only look at two memories at a time, the ultimate goal is to understand a whole network of memories. More than that, Josselyn says, the aim is to understand how memories layer on each other. Put more simply, she adds, “what is knowledge, as opposed to what is a specific memory?”

To answer that question they must enter largely untrodden territory. To date this study is only the second of its kind. Josselyn and Frankland studied overlapping memory formation in a brain region called the amygdala, associated with fear experience recollection. In a Nature article published in June neuroscientist Alcino Silva at the University of California, Los Angeles, and his colleagues found the same principle to hold true in the hippocampus, which stores more factual knowledge.

The interaction between memories is in fact a fundamental part of how we form a coherent view of the world. That is a massive goal but these experiments have pushed us in the right direction. “This is a stepping-stone toward understanding how we link information across time,” Silva says, “and I think that’s one of the great mysteries of science because behind that is our ability to understand our world.”

Source: Scientific American (by Sara Chodosh)

¡El arte en la ciencia! Guapa cepa de Colletotrichum. #IsBeautyFull ;) #science #biotechnologylab #biotechnology #DoScience #Agrigenomics (en ENES León Guanajuato)

#biotechnologylab #science #doscience #agrigenomics #isbeautyfull #biotechnology

#Guanajuato

#guanajuato

illustratedwomeninhistory

Ada Lovelace was a British Analyst, Metaphysician, and Founder of Scientific Computing. Lovelace was born Ada Gordon in 1815. Her father, George Gordon, Lord Byron and her mother Annabella Milbanke separated when she was a month old. A few months later, Lord Byron left England and never saw Ada again. Lovelace’s mother raised her under a strict regimen of science, logic, and mathematics so that she would not succumb to her father’s ‘poetic madness’. Lovelace was also forced to lie still for extended periods of time in the hope that it would help her develop self-control. Lovelace was talented with numbers and language from an early age and was fascinated with machines, she poured over diagrams of new inventions of the Industrial Revolution that filled the scientific magazines. Lovelace was taught by William Frend, a social reformer; William King, the family’s doctor; and Mary Somerville, a Scottish astronomer and mathematician. Somerville was one of the first women to be admitted into the Royal Astronomical Society. At the age of 17, Lovelace met Charles Babbage, Lucasian professor of mathematics at Cambridge. He was known as the inventor of the Difference Engine, an elaborate calculating machine that operated by the method of finite differences. Babbage became a mentor to Lovelace and through him, she began studying advanced mathematics with University of London professor Augustus de Morgan. At 19 Lovelace married William King, an aristocrat ten years her senior. King was made Earl of Lovelace in 1838 and Lovelace became Lady Ada King, Countess of Lovelace, although she is simply known as Ada Lovelace. In 1834 Babbage had created plans for a new kind of calculating machine called an Analytical Engine but he had not at that point finished his Difference Engine. He gained support for his project abroad and in 1842 the Italian mathematician, Louis Menebrea, published a memoir in French on the subject of the Analytical Engine. Lovelace translated the short article describing the Analytical Engine so that it could be published in England. She was asked to elaborate on the article as she understood the subject so well, her notes, thoughts and other additions expanded the article to three times the length of the original. Her insights included several early ‘computer programs’ including a method for calculating a sequence of Bernoulli numbers with the Engine. Her plan would have run correctly if the Analytical engine had been built and is recognised as the world’s first computer program. Her ideas were the first to be published on the matter and so she is thought of as “the first computer programmer.” She also noted her observations on the potential uses of of the machine, including the manipulation of symbols and creation of music. Lovelace did not get recognition for her work during her lifetime but in the 1940’s Lovelace’s notes became one of the critical documents to inspire Alan Turing’s work on the first modern computers. In the 1950’s her notes were republished in Faster Than Thought: A Symposium on Digital Computing Machines in 1953 bringing her recognition and leading to her recieving many posthumour honors for her work. In the 1980’s the U.S. Department of Defense named a newly developed computer language “Ada,” after Lovelace and since 1998 the British Computer Society has awarded a medal in her name and in 2008 they initiated an annual competition for women students of computer. Ada Lovelace has inspired “Ada Lovelace Day” an annual event to raise the profile of women in science, technology, engineering and maths. There is also a non-profit organisation edicated to increasing the involvement of women in the free culture and open source movements named after her called 'The Ada Initiative’. Sources here, here, here and here

biotecnologiasi

Una bacteria modificada convierte la energía del Sol en combustible líquido

Científicos de EE UU logran almacenar el inagotable poder energético solar en un alcohol; una bacteria que vive entre heces desafía a los amos del petróleo

Almacenar la inagotable energía del Sol, sometida a los vaivenes de las nubes y del día y la noche, está más cerca. Investigadores de la Universidad de Harvard (EE UU) han concebido un sofisticado sistema que utiliza una bacteria modificada genéticamente para convertir la energía solar en un combustible líquido. El enfoque, si confirma su rentabilidad, ayudaría a afrontar el desafío energético y a luchar contra el cambio climático.

Los investigadores, encabezados por el químico estadounidense Daniel Nocera, han utilizado la energía del Sol para obtener hidrógeno del agua (formada por dos átomos de hidrógeno y uno de oxígeno). Con este hidrógeno, la bacteria modificada, de la especie Ralstonia eutropha, es capaz de convertir CO2, el principal gas responsable del calentamiento global, en un alcohol combustible, el isopropanol. Al ser líquido, podría ser transportado mediante las infraestructuras actuales, subrayan los autores.

Nocera lleva años acariciando una revolución energética planetaria. En 2009, fue considerado una de las 100 personas más influyentes del mundo por la revista Time como reconocimiento a sus avances hacia combustibles inspirados en la fotosíntesis de las plantas.

Al ser líquido, el combustible podría ser transportado mediante las infraestructuras actuales “Las células fotovoltaicas tienen un considerable potencial para satisfacer las futuras necesidades de energía renovable, pero se necesitan métodos eficientes y escalables para almacenar la electricidad intermitente que producen y poder implantar la energía solar a gran escala”, explican los autores hoy en la revista científica PNAS. Su sistema podría ser ese anhelado almacén de energía solar.

Otros equipos científicos han llegado a métodos similares, pero han necesitado acelerar las reacciones químicas con metales preciosos, como el platino y el indio, disparando los costes. El equipo de Nocera emplea como catalizadores metales abundantes en la Tierra, como el cobalto, logrando un rendimiento que triplica el de los mejores combustibles bioelectroquímicos existentes, logrados por sistemas parecidos. Para los autores, es “una importante prueba de concepto”.

“Todavía no vamos a utilizar este sistema en nuestros coches. De momento, es solo un descubrimiento científico. Ahora tenemos que mejorar las ineficiencias para que sea comercial, aunque ya somos tan eficientes, o más, que la fotosíntesis natural”, señala Nocera.

Ninguna empresa se ha interesado todavía por el nuevo sistema. El año pasado, la multinacional estadounidense Lockheed Martin, un gigante de la industria aeroespacial y militar, compró uno de los anteriores productos del laboratorio de Nocera: una especie de hoja artificial que utiliza la energía solar para separar el hidrógeno y el oxígeno del agua. El hidrógeno también se puede emplear como combustible, aunque hay pocas infraestructuras para facilitar su uso.

Hace dos años, científicos de la Universidad de Exeter (Reino Unido) y de la petrolera Shell modificaron los genes de otra bacteria, la Escherichia coli, para que fabricara diésel a partir de ácidos grasos. El biocombustible, prometedor, también se enfrenta ahora a desafíos para su comercialización, como su abaratamiento. En 2013, producir un litro costaba miles de euros.

How our brains make memories. By tracking mRNA in brain cells, scientists captured the brain making memories. Hye Yoon Park, Ph.D.

What is art? What is copy?

polvoramx

#LunesVisual

Fideo Maldad

¡¡Go, go, go-Grow, grow, grow!!

genteyhogaressostenibles

Curso Completo Diseño y Cultivo Huerto Ecológico

MÓDULO I: DISEÑO INTEGRAL, CREACIÓN Y PREPARACIÓN DEL HUERTO, MANEJO DE SEMILLEROS Y PLANTELES MÓDULO IICURSO COMPLETO DE COMPOSTAJE MICROORGANISMOS EFECTIVOS, VERMICOMPOST

Más información: La Ruta Natural

ipoecollection

sersh

rookiemag

“I get a lot of adults who are like, ‘You don’t know shit,’ and it’s like, ‘You don’t know shit. You have no idea what it’s like to be 17 years old.’” - Maisie Williams for Dazed Magazine’s Spring/Summer 2015 Issue [x]

That quote!

- Hazel