CONTRA EL PINGALISMO CASTRISTA/
"Se que no existe el consuelo
que no existe
la anhelada tierrra de mis suenos
ni la desgarrada vision de nuestros heroes.
Pero
te seguimos buscando, patria,..." - Reinaldo Arenas
Photonic
quantum computer: two spontaneous photon-pair source are integrated
within a tuneable Mach-Zehnder interferometer. The system is capable of
generating and manipulating path-entangled two-photon states (credit: J.
W. Silverstone et al./Nature Photonics)
Scientists and engineers from an international collaboration led by Mark Thompson from the University of Bristol
have, for the first time, generated and manipulated single photons on a
silicon chip — a major step forward in the race to build a quantum
computer, achieved by shrinking down key components and integrating them
onto a silicon microchip, according to the researchers.
Previous attempts have required external light sources to generate
the photons; this new chip integrates components that can generate
photons inside the chip.
Potential for scaling
“We were surprised by how well the integrated sources performed
together,” admits Joshua Silverstone, lead author of the paper. “They
produced high-quality identical photons in a reproducible way,
confirming that we could one day manufacture a silicon chip with
hundreds of similar sources on it, all working together. This could
eventually lead to an optical quantum computer capable of performing
enormously complex calculations.”
“Single-photon detectors, sources and circuits have all been
developed separately in silicon but putting them all together and
integrating them on a chip is a huge challenge,” said Thompson.
“Our device is the most functionally complex photonic quantum circuit
to date, and was fabricated by Toshiba using exactly the same
manufacturing techniques used to make conventional electronic devices.
We can generate and manipulate quantum entanglement all within a single
millimeter-sized microchip.”
The group, which, includes researchers from Toshiba Corporation
(Japan), Stanford University (US), University of Glasgow (UK) and TU
Delft (The Netherlands), now plans to integrate the remaining necessary
components onto a chip, and show that large-scale quantum devices using
photons are possible.
“Our group has been making steady progress towards a functioning
quantum computer over the last five years,” said Thompson. “We hope to
have within the next couple of years, photon-based devices complex
enough to rival modern computing hardware for highly-specialized tasks.”
Bristol’s newly established Centre for Doctoral Training in Quantum Engineering
will train a new generation of engineers, scientists, and entrepreneurs
to harness the power of quantum mechanics and lead the quantum
technology revolution. This innovative center bridges the gaps between
physics, engineering, mathematics and computer science, working closely
with chemists and biologists while interacting strongly with industry.
K. Eric Drexler is known as the founding father of nanotechnology—the science of engineering on a molecular level. In Radical Abundance, he shows how rapid scientific progress is about to change our world. Thanks to atomically precise manufacturing, we will soon have the power to produce radically more of what people want, and at a lower cost. The result will shake the very foundations of our economy and environment.
Already, scientists have constructed prototypes for circuit boards built of millions of precisely arranged atoms. The advent of this kind of atomic precision promises to change the way we make things—cleanly, inexpensively, and on a global scale. It allows us to imagine a world where solar arrays cost no more than cardboard and aluminum foil, and laptops cost about the same.
A provocative tour of cutting edge science and its implications by the field’s founder and master, Radical Abundance offers a mind-expanding vision of a world hurtling toward an unexpected future.
The topics include:
The nature of science and engineering, and the prospects for a deep transformation in the material basis of civilization.
Why all of this is surprisingly understandable.
A personal narrative of the emergence of the molecular nanotechnology concept and the turbulent history of progress and politics that followed
The quiet rise of macromolecular nanotechnologies, their power, and the rapidly advancing state of the art
Incremental paths toward advanced nanotechnologies, the inherent accelerators, and the institutional challenges
The technologies of radical abundance, what they are, and what they will enable
Disruptive solutions for problems of economic development, energy, resource depletion, and the environment
Potential pitfalls in competitive national strategies; shared interests in risk reduction and cooperative transition management
Steps toward changing the conversation about the future
A miniature artificial human liver has been grown by British scientists in a major medical breakthrough this week.
LONDON: A miniature artificial human liver has been grown by British scientists in a major medical breakthrough this week.
The organ, which is about the size of a thumbnail, was grown using stem cells in blood taken from umbilical cords.
It is hoped such mini-livers could be used to test drugs – reducing the need for animal experiments – to help repair damaged livers and eventually to produce entire organs for lifesaving transplants.
Colin McGuckin, a professor specialising in regenerative medicine, made the breakthrough with Nico Forraz at Newcastle University in northeast England.
While other scientists have created liver cells, the Newcastle team are the first to create sizeable sections of tissue from stem cells from the umbilical cord.
The pair extracted blood from the umbilical cords of newborn babies. They were then placed in a ‘bioreactor’ developed by the U.S. space agency NASA, which mimics the effects of weightlessness. This allowed the cells to multiply more quickly. Chemicals and hormones were then added to encourage the stem cells to turn into liver tissue.
“We take the stem cells from the umbilical cord blood and make small mini-livers,” said McGuckin. “We then give them to pharmaceutical companies and they can use them to test new drugs on.
“When a drug company is developing a new drug it first tests it on human cells and then tests it on animals before beginning trials on humans,” he said.
He added that: “Moving from testing on animals to humans is a massive leap and there is still a risk. But by using the mini-livers we have developed there is no need to test on animals or humans.”
The mini-livers could potentially be used like dialysis machines, buying time for a patient’s liver to repair itself or for doctors to find a replacement liver, according to the researchers.
Professor Ian Gilmore, a liver specialist at the Royal Liverpool Hospital in northwest England, said that the Newcastle team had made a “big ethical leap forward” in not requiring embryos to produce tissue.
“It is exciting because there is a real dearth of treatments available for people with liver disease,” he said.
LONDON - Scientists have grown the first mini human brains in a laboratory and say their success could lead to new levels of understanding about the way brains develop and what goes wrong in disorders like schizophrenia and autism.
Researchers based in Austria started with human stem cells and created a culture in the lab that allowed them to grow into so-called "cerebral organoids" - or mini brains - that consisted of several distinct brain regions.
It is the first time that scientists have managed to replicate the development of brain tissue in three dimensions.
Using the organoids, the scientists were then able to produce a biological model of how a rare brain condition called microcephaly develops - suggesting the same technique could in future be used to model disorders like autism or schizophrenia that affect millions of people around the world.
"This study offers the promise of a major new tool for understanding the causes of major developmental disorders of the brain ... as well as testing possible treatments," said Paul Matthews, a professor of clinical neuroscience at Imperial College London, who was not involved in the research but was impressed with its results.
Zameel Cader, a consultant neurologist at Britain's John Radcliffe Hospital in Oxford, described the work as "fascinating and exciting". He said it extended the possibility of stem cell technologies for understanding brain development and disease mechanisms - and for discovering new drugs.
Although it starts as relatively simple tissue, the human brain swiftly develops into the most complex known natural structure, and scientists are largely in the dark about how that happens.
This makes it extremely difficult for researchers to gain an understanding of what might be going wrong in - and therefore how to treat - many common disorders of the brain such as depression, schizophrenia and autism.
GROWING STEM CELLS
To create their brain tissue, Juergen Knoblich and Madeline Lancaster at Austria's Institute of Molecular Biotechnology and fellow researchers at Britain's Edinburgh University Human Genetics Unit began with human stem cells and grew them with a special combination of nutrients designed to capitalise on the cells' innate ability to organise into complex organ structures.
They grew tissue called neuroectoderm - the layer of cells in the embryo from which all components of the brain and nervous system develop.
Fragments of this tissue were then embedded in a scaffold and put into a spinning bioreactor - a system that circulates oxygen and nutrients to allow them to grow into cerebral organoids.
After a month, the fragments had organised themselves into primitive structures that could be recognized as developing brain regions such as retina, choroid plexus and cerebral cortex, the researchers explained in a telephone briefing.
At two months, the organoids reached a maximum size of around 4 millimetres (0.16 inches), they said. Although they were very small and still a long way from resembling anything like the detailed structure of a fully developed human brain, they did contain firing neurons and distinct types of neural tissue.
"This is one of the cases where size doesn't really matter," Knoblich told reporters.
"Our system is not optimized for generation of an entire brain and that was not at all our goal. Our major goal was to analyze the development of human brain (tissue) and generate a model system we can use to transfer knowledge from animal models to a human setting."
In an early sign of how such mini brains may be useful for studying disease in the future, Knoblich's team were able to use their organoids to model the development of microcephaly, a rare neurological condition in which patients develop an abnormally small head, and identify what causes it.
Both the research team and other experts acknowledged, however, that the work was a very long way from growing a fully-functioning human brain in a laboratory.
"The human brain is the most complex thing in the known universe and has a frighteningly elaborate number of connections and interactions, both between its numerous subdivisions and the body in general," said Dean Burnett, lecturer in psychiatry at Cardiff University.
"Saying you can replicate the workings of the brain with some tissue in a dish in the lab is like inventing the first abacus and saying you can use it to run the latest version of Microsoft Windows - there is a connection there, but we're a long way from that sort of application yet."
A close up of an organoid with retinal tissue (brown)./ www.theverge.com
Jan Scheuermann, who has quadriplegia, brings a chocolate bar to her mouth using a robot arm she is guiding with her thoughts, while researcher Elke Brown, M.D., watches in the background (credit: UPMC)
Reaching out to “high five” someone, grasping and moving objects of different shapes and sizes, feeding herself dark chocolate.
For Jan Scheuermann and a team of researchers from the University of Pittsburgh School of Medicine and UPMC, accomplishing these seemingly ordinary tasks demonstrated for the first time that a person with longstanding quadriplegia can maneuver a mind-controlled, human-like robot arm in seven dimensions (7D) to consistently perform many of the natural and complex motions of everyday life.
In a study published in the online version of The Lancet, the researchers described the brain-computer interface (BCI) technology and training programs that allowed Ms. Scheuermann, 53, to intentionally move an arm, turn and bend a wrist, and close a hand for the first time in nine years.
Less than a year after she told the research team, “I’m going to feed myself chocolate before this is over,” Ms. Scheuermann savored its taste and announced as they applauded her feat, “One small nibble for a woman, one giant bite for BCI.”
“This is a spectacular leap toward greater function and independence for people who are unable to move their own arms,” agreed senior investigator Andrew B. Schwartz, Ph.D., professor, Department of Neurobiology, Pitt School of Medicine. “This technology, which interprets brain signals to guide a robot arm, has enormous potential that we are continuing to explore. Our study has shown us that it is technically feasible to restore ability; the participants have told us that BCI gives them hope for the future.”
On Feb. 10, 2012, after screening tests to confirm that she was eligible for the study, co-investigator and UPMC neurosurgeon Elizabeth Tyler-Kabara, M.D., Ph.D., assistant professor, Department of Neurological Surgery, Pitt School of Medicine, placed two quarter-inch square electrode grids with 96 tiny contact points each in the regions of Ms. Scheuermann’s brain that would normally control right arm and hand movement.
The electrode points pick up signals from individual neurons and computer algorithms are used to identify the firing patterns associated with particular observed or imagined movements, such as raising or lowering the arm, or turning the wrist, explained lead investigator Jennifer Collinger, Ph.D., assistant professor, Department of Physical Medicine and Rehabilitation (PM&R), and research scientist for the VA Pittsburgh Healthcare System. That intent to move is then translated into actual movement of the robot arm, which was developed by Johns Hopkins University’s Applied Physics Lab.
Two days after the operation, the team hooked up the two terminals that protrude from Ms. Scheuermann’s skull to the computer. “We could actually see the neurons fire on the computer screen when she thought about closing her hand,” Dr. Collinger said. “When she stopped, they stopped firing. So we thought, ‘This is really going to work.’”
7D control
How the neuroprosthetic system works. Two silicon-substrate microelectrode arrays surgically implanted in the motor cortex (upper right) allow recordings of ensemble neuronal activity, which are then translated into intended movement commands. This brain-derived information is conveyed to a shared controller that integrates the participant’s intent, robotic position feedback, and task-dependent constraints. Using this bioinspired brain-machine interface, the paralyzed woman could manipulate objects of various shapes and sizes in a 3D workspace. (Credit: Jennifer L Collinger et al./The Lancet)
Within a week, Ms. Scheuermann could reach in and out, left and right, and up and down with the arm, which she named Hector, giving her 3-dimensional control that had her high-fiving with the researchers. “What we did in the first week they thought we’d be stuck on for a month,” she noted.
Before three months had passed, she also could flex the wrist back and forth, move it from side to side and rotate it clockwise and counter-clockwise, as well as grip objects, adding up to what scientists call 7D control.
In a study task called the Action Research Arm Test, Ms. Scheuermann guided the arm from a position four inches above a table to pick up blocks and tubes of different sizes, a ball and a stone and put them down on a nearby tray. She also picked up cones from one base to restack them on another a foot away, another task requiring grasping, transporting and positioning of objects with precision.
“Our findings indicate that by a variety of measures, she was able to improve her performance consistently over many days,” Dr. Schwartz explained. “The training methods and algorithms that we used in monkey models of this technology also worked for Jan, suggesting that it’s possible for people with long-term paralysis to recover natural, intuitive command signals to orient a prosthetic hand and arm to allow meaningful interaction with the environment.”
Electrocortigraphy (ECoG) study
In a separate study, researchers also continue to study BCI technology that uses an electrocortigraphy (ECoG) grid, which sits on the surface of the brain rather than slightly penetrates the tissue as in the case of the grids used for Ms. Scheuermann.
In both studies, “we’re recording electrical activity in the brain, and the goal is to try to decode what that activity means and then use that code to control an arm,” said senior investigator Michael Boninger, M.D., professor and chair, PM&R, and director of UPMC Rehabilitation Institute. “We are learning so much about how the brain controls motor activity, thanks to the hard work and dedication of our trial participants. Perhaps in five to 10 years, we will have a device that can be used in the day-to-day lives of people who are not able to use their own arms.”
The next step for BCI technology will likely use a two-way electrode system that can not only capture the intention to move, but in addition, will stimulate the brain to generate sensation, potentially allowing a user to adjust grip strength to firmly grasp a doorknob or gently cradle an egg.
After that, “we’re hoping this can become a fully implanted, wireless system that people can actually use in their homes without our supervision,” Dr. Collinger said. “It might even be possible to combine brain control with a device that directly stimulates muscles to restore movement of the individual’s own limb.”
For now, Ms. Scheuermann is expected to continue to put the BCI technology through its paces for two more months, and then the implants will be removed in another operation.
“This is the ride of my life,” she said. “This is the rollercoaster. This is skydiving. It’s just fabulous, and I’m enjoying every second of it.”
The BCI projects are funded by the Defense Advanced Research Projects Agency, National Institutes of Health, the U.S. Department of Veteran’s Affairs, the UPMC Rehabilitation Institute and the University of Pittsburgh Clinical and Translational Science Institute.
For more information about participating in the trials, call 412-383-1355.
How this compares to previous studies
The results of previous work have shown that neural activity can be recorded from the motor cortex and translated to movement of an external device or the individual’s own muscles, the authors say. However, until now, the results of human studies have not shown whether the natural and complex movements can be done consistently for different tasks.
“Here, we have shown that a person with chronic tetraplegia can do complex and coordinated movements freely in seven-dimensional space consistently over several weeks of testing. This study is different from previous studies in which investigators had little control in translation dimensions, used staged control schemes, or had insufficient workspace to complete very structured tasks.
“Increasing dimensional control allows our participant to fully explore the workspace by placing the hand in the desired three-dimensional location and orienting the palm in three dimensions. This study is the first time that performance has been quantified with functional clinical assessments. Although in most human studies only a few days of performance data were reported, we have shown that the participant learned to improve her performance consistently over many days using different metrics.
“By using training methods and algorithms validated in non-human primate work, individuals with long-term paralysis can recover the natural and intuitive command signals for hand placement, orientation, and reaching to move freely in space and interact with the environment.”
In 2005 engineers at the U.S. Department of Energy's (DoE) Oak Ridge National Laboratory unveiled Jaguar, a system that would later be upgraded into a world-beating supercomputer. By 2011 it had grown to a room-size system that used seven megawatts of energy, ran nearly 225,000 processor cores and had a peak performance of 2.3 petaflops, or 2.3 quadrillion calculations per second. Topping Jaguar, albeit necessary to deliver ever more complex modeling of sophisticated energy challenges, would not be easy.
Simply adding more CPUs, or central processing units, to scale Jaguar to 20 petaflops would require enough energy to power 60,000 homes. To best their own record, the Oak Ridge engineers instead turned to video games—or more precisely, to the graphics processors used in Microsoft Xboxes, Nintendo Wiis and other video game systems.
As of Monday Jaguar becomes Titan, a supercomputer that leverages both CPU and GPU (graphics processing unit) accelerators to deliver 10 times the performance of Jaguar with more than five times the power efficiency.
The key to Titan's speed and efficiency is a design that uses more than 18,500 NVIDIA GPUs, along with nearly 300,000 CPU cores, which typically form the foundation of high-performance computers. The GPUs account for about 90 percent of the system's computational performance and enable Titan to remain roughly the same size as Jaguar.
When fully brought up to speed, Titan (a Cray XK7 system) promises to be the world's most powerful open-science supercomputer, even more powerful than the DoE's Sequoia, a 16.3-petaflop IBM Blue Gene/Q system crowned the world's fastest supercomputer in June. Sequoia differs from Jaguar/Titan, which placed sixth on the list, in that Sequoia is used exclusively by the DoE's National Nuclear Security Administration to monitor U.S. nukes. Titan will be used by a variety of researchers for a variety of projects.
Titan will initially support a handful of key projects at Oak Ridge, including Denovo, simulation software that models the behavior of neutrons in a nuclear power reactor. Oak Ridge's engineers designed Denovo for Jaguar as a way to help extend the lives of the U.S.'s aging nuclear power plants, which provide about a fifth of the country's electricity. Running Denovo, Titan will take 13 hours to model the complete state of a reactor core at a specified point in time, a job that took Jaguar 60 hours to perform.
"The ability to burn nuclear fuel uniformly is very much dependent on knowing and being able to predict the distribution of neutrons in the core," says Tom Evans, a computational scientist at Oak Ridge's Consortium for the Advanced Simulation of Light Water Reactors (CASL), which created Denovo. Titan will enable much more precise simulations.
Titan calculations will also be used to provide nanoscale analysis of materials used to build electric motors and generators as well as model the burning of a variety of fuels in internal combustion engines. Still another application will simulate long-term global climate. A sizable amount of Titan's capacity in the coming year will be devoted to the DoE's Innovative and Novel Computational Impact on Theory and Experiment program (INCITE), which invites academia, government researchers and industry to apply for access to the supercomputer for their various projects. More >>
The RSC web site features an article on molecular machines written by
Josh Howgego that gives a very good brief introduction to the topic: Rise of the molecular machines. A downloadable PDF of the article as it originally appeared in Education in Chemistry
provides better images of the figures than does the HTML version. The
article explains how chemists have worked to mimic the function of
biological molecular machine like muscles, by using intermolecular
forces to control movements of mechanically interlocked molecules. The
first example given is from the work of Fraser Stoddart, winner of the 2007 Feynman Prizes in Nanotechnology for Experimental work and Co-Chair of the January 2013 Foresight Technical Conference: Illuminating Atomic Precision, which will feature a session
on “Molecular Machines and Non-Equilibrium Processes,” which Prof.
Stoddart will chair. The article goes on to explain that harnessing
simple molecular shuttles of the type pioneered by Stoddart to do real
work like muscles has proved difficult, and cites as a prototype
solution a molecular machine that works in a different way: a walker
that sequentially makes and breaks different types of covalent bonds,
developed by David Leigh, winner of the 2007 Feynman Prizes in Nanotechnology
in the Theory category. The article finishes with a description of a
nanocar developed by Ben Feringa that uses electricity to move across a
metal surface by rotating paddle-like wheels.
Eric Selby, uno de los usuarios de las gafas Argus II
En las últimas semanas se está hablando bastante de un par de «ojos
biónicos» que pronto podrían empezar a ser utilizados de forma regular
en humanos, al menos en Europa.
Uno de ellos es el Argus II,
desarrollado por Second Sight, que consiste en unas gafas que llevan
una cámara que van conectadas a una unidad de procesamiento de imagen
donde y que tienen un transmisor para enviar las señales al implante.
Gafas Argus II
Este va colocado en la parte exterior del globo ocular, donde se
alojan la antena y la electrónica que lo hacen funcionar, que a su vez
envían las señales pertinentes a una serie de electrodos que van
implantados en la retina.
El otro es el llamado Nano Retina,
que lleva el sensor en el interior del ojo y que usa unas gafas que
emiten un láser casi infrarrojo que permite a las células fotoelétricas
del implante obtener energía para que este funcione, eliminando la
necesidad de usar baterías externas como en el caso del Argus II.
El Argus II es el más caro de los dos, con un precio de unos 115.000
dólares, y necesita una operación de 4 horas para su implantación; el
Nano Retina ronda los 60.000 dólares y se implanta en media hora con una
operación con anestesia local.
El Argus II proporciona el equivalente de un display de 60 pixeles en
forma de patrones de luz que el cerebro del paciente tiene que aprender
a interpretar y hasta ahora ha dado resultados prometedores, dentro de
sus limitaciones, como por ejemplo en el caso de Eric Selby, quien entre otras cosas es de nuevo capaz de distinguir la acera de la calzada desde que lleva uno de estos implantes.
El Nano Retina, por su parte, da una resolución de 24x24 en su
primera versión, que ya ha sido fabricada y será sometida a pruebas con
humanos en 2013, mientras que la segunda generación dará una resolución
de 72x72, y el fabricante dice que permitirá a los pacientes que lo
reciban ver la televisión e identificar caras, a pesar de que si nos
atenemos al vídeo da la impresión de que hasta podrían leer, algo por
ahora muy lejos de las posibilidades de estos dispositivos.
Estas prestaciones, por supuesto, se quedan muy cortas no solo comparadas con el ojo biónico de Lee Austin, el hombre de los seis millones de dólares, sino con nuestros ojos naturales, pero no hay que olvidar que desarrollar este tipo de implantes tiene un serio problema.
Y es que no sabemos lo suficiente acerca del proceso mediante el que
el cerebro y el ojo se entienden y como el segundo convierte la luz que
recibe en las señales que envía al cerebro, así que vamos un poco a ojo
en todo esto.
Para avanzar en esta dirección hay estudios que han recogido las
señales que circulan por el nervio óptico de un animal cuando su ojo ve
imágenes y que a base de analizarlas han conseguido reproducir los patrones correspondientes,
o al menos eso se supone, aunque falta todavía probar esto en humanos.
Es una técnica que además quizás se podría aplicar a los demás sentidos
si se demuestra que funciona correctamente.
Otra imitación es que las prótesis actuales, tanto las dos
mencionadas como otras en desarrollo, necesitan además que el nervio
óptico del paciente funcione correctamente, por lo que sólo son útiles
en caso de patologías que provocan una degeneración de la retina.
Pero en cualquier caso son un paso más en la dirección de poder ir
parcheando nuestros cuerpos mediante la tecnología, algo que quizás
algún día nos haga más que humanos.
seria conveniente que el vastago de castro 1 y la ministra de ciencia, tecnologia y medio ambiente [cargo donde sobran las tres denominaciones] dejaran la boberia de la nanotecnologia kubiche y arrancaran por donde es, la frontera tecnologica del asunto. pero que la'bana retome el ritual aspergiano [del sindrome] cientifico-tecnologico tantas veces ejecutado por el mesias del bonche en jefe, es caricaturisticamente entendible pero, que los medios desde el nuevo herald hasta el abc iberico lo repitan amplificadamente sin filtrarlo como corresponde, es una conducta esquizofrenica y/ o manipuladora.
Almacenar datos informáticos en secuencias de ADN o en soportes de
memoria basados en ADN puede sonar raro y lo es. Pero es posible y al
parecer es un método bastante capaz: un grupo de investigadores ha
conseguido almacenar unos 700 terabytes (unos 720.000 GB) en un gramo de
ADN.
Al fin y al cabo el ADN almacena información, que es algo que nos
encanta hacer a los humanos; nos pasamos el día averiguando dónde más y
cómo almacenar datos con la mayor capacidad y velocidad de acceso a
ellos que sea posible. Y el ADN parece un buen lugar: un disco Blu-Ray
puede contener hasta 25GB, o 50 GB si es de capa doble, por lo que hacen
falta unos 14.000 para igualar la capacidad de un gramo de ADN. Más
aún, almacenar una cantidad de información equivalente supondrían más de
230 discos duros de 3 TB, que suponen unos 150 kilos de peso, calculan en ExtremeTech.
Hace unos meses un equipo de genetistas y nanoingenieros combinaron ADN de salmón y nanopartículas de plata para construir un soporte de memoria
que funciona de forma similar a un disco óptico. Es decir, se escribe
la información una vez, la cual queda secuenciada en el ADN, y se puede
leer tantas veces como se quiera. Según los investigadores una vez
configurado el polímero compuesto por ADN y nanopartículas el patrón de
datos se mantiene inalterable de forma indefinida.
Tanto si el destino es una memoria basada en ADN como una secuencia
de ADN convencional el proceso es similar: primero hay que convertir la
información digital, que se expresa en forma de 1 y 0 en el lenguaje del
ADN, que utiliza las bases A, G, T y C.
Por ejemplo, los ceros se convierten en el par de bases A o C y los
unos en las bases G o T. La secuencia codificada se guarda en cadenas de
ADN convencional o modificado, caso del modelo con nanopartículas de
plata. Así es como un investigador guardó miles de millones de copias de
su último libro en un pequeño tubo de ensayo «y en condiciones normales
durarará cientos de años». O lo que es lo mismo: un dispositivo con
este tipo de memoria puede almacenar, «en lo que ocupa un dedo pulgar
tanta información como la que hay en Internet».
De momento la técnica sigue estando limitada a su uso en laboratorio y
al desarrollo de variantes basadas en el mismo principio, pero el coste
de secuenciar ADN se ha reducido significativamente en los últimos 10 años, pasando de los 10.000 dólares por cada millón de par de bases secuenciada a los 10 céntimos por millón actuales.
For years artificial muscles have promised to deliver a more flexible, more durable alternative to electric motors and hydraulic systems. These lab-made actuators are usually created by putting an electrical charge into a piece of polymer or into an aerogel sheet made from carbon nanotubes, causing those materials to expand and contract. This motion could someday be used to power turbines, animate robots or move prosthetic limbs.
In a new study published in the October 14 issue of Science, an international team of researchers describes how they’re taking carbon nanotube artificial muscles in a new direction. Scientists at the University of Texas at Dallas’ Alan G. MacDiarmid NanoTech Institute have already demonstrated in the lab the ability of these muscle-like carbon nanotubes to flex even in extreme temperatures that would freeze or, on the other end of the spectrum, decompose electroactive polymer-based artificial muscles.
Their latest work—with scientists from the University of Wollongong in Australia, the University of British Columbia in Canada, and Hanyang University in Korea—indicates that these carbon nanotubes can be spun into yarns (see inset to the left) and, when dipped into an electrolyte solution, move in a twisting direction that mimics the stiffness, extension, bending and torsion of natural muscles found in an elephant’s trunk and squid tentacles. The researchers found that the yarns can even untwist (moving with the opposite rotation) when the applied voltage is changed. More >
If you give a nanodiamond to your fiancée, you can forget about the wedding. But a new study reports that these tiny flecks of carbon can shrink tumors in mice by delivering chemotherapy drugs to cancer cells.
Lead author Dean Ho, a biomedical engineer at Northwestern University in Evanston, Illinois, says that one of the major challenges in chemotherapy is when tumor cells develop mechanisms to pump drugs right back out. But Ho reasoned that when the drug is bound to a nanoparticle, the combination would be too large for the pump, so tumors would have a hard time evolving resistance.
If you give a nanodiamond to your fiancée, you can forget about the wedding. But a new study reports that these tiny flecks of carbon can shrink tumors in mice by delivering chemotherapy drugs to cancer cells.
Lead author Dean Ho, a biomedical engineer at Northwestern University in Evanston, Illinois, says that one of the major challenges in chemotherapy is when tumor cells develop mechanisms to pump drugs right back out. But Ho reasoned that when the drug is bound to a nanoparticle, the combination would be too large for the pump, so tumors would have a hard time evolving resistance. More Here
¨Saturno jugando con sus hijos¨/ Pedro Pablo Oliva
Seguidores
Carta desde la carcel de Fidel Castro Ruz
“…después de todo, para mí la cárcel es un buen descanso, que sólo tiene de malo el que es obligatorio. Leo mucho y estudio mucho. Parece increíble, las horas pasan como si fuesen minutos y yo, que soy de temperamento intranquilo, me paso el día leyendo, apenas sin moverme para nada. La correspondencia llega normalmente…”
“…Como soy cocinero, de vez en cuando me entretengo preparando algún pisto. Hace poco me mandó mi hermana desde Oriente un pequeño jamón y preparé un bisté con jalea de guayaba. También preparo spaghettis de vez en cuando, de distintas formas, inventadas todas por mí; o bien tortilla de queso. ¡Ah! ¡Qué bien me quedan! por supuesto, que el repertorio no se queda ahí. Cuelo también café que me queda muy sabroso”. “…En cuanto a fumar, en estos días pasados he estado rico: una caja de tabacos H. Upman del doctor Miró Cardona, dos cajas muy buenas de mi hermano Ramón….”. “Me voy a cenar: spaghettis con calamares, bombones italianos de postre, café acabadito de colar y después un H. Upman #4. ¿No me envidias?”. “…Me cuidan, me cuidan un poquito entre todos. No le hacen caso a uno, siempre estoy peleando para que no me manden nada. Cuando cojo el sol por la mañana en shorts y siento el aire de mar, me parece que estoy en una playa… ¡Me van a hacer creer que estoy de vacaciones! ¿Qué diría Carlos Marx de semejantes revolucionarios?”.
Quotes
¨La patria es dicha de todos, y dolor de todos, y cielo para todos, y no feudo ni capellanía de nadie¨ - Marti
"No temas ni a la prision, ni a la pobreza, ni a la muerte. Teme al miedo" - Giacomo Leopardi
¨Por eso es muy importante, Vicky, hijo mío, que recuerdes siempre para qué sirve la cabeza: para atravesar paredes¨– Halvar de Flake[El vikingo]
"Como no me he preocupado de nacer, no me preocupo de morir"- Lorca
"Al final, no os preguntarán qué habéis sabido, sino qué habéis hecho" - Jean de Gerson
"Si queremos que todo siga como está, es necesario que todo cambie" - Giuseppe Tomasi di Lampedusa
"Todo hombre paga su grandeza con muchas pequeñeces, su victoria con muchas derrotas, su riqueza con múltiples quiebras" - Giovanni Papini
"Life is what happens while you are busy making other plans" - John Lennon
"Habla bajo, lleva siempre un gran palo y llegarás lejos" - Proverbio Africano
"No hay medicina para el miedo"-Proverbio escoces "El supremo arte de la guerra es doblegar al enemigo sin luchar" -Sun Tzu
"You do not really understand something unless you can explain it to your grandmother" - Albert Einstein
"It is inaccurate to say I hate everything. I am strongly in favor of common sense, common honesty, and common decency. This makes me forever ineligible for public office" - H. L. Menken
"I swore never to be silent whenever and wherever human beings endure suffering and humiliation. We must always take sides. Neutrality helps the oppressor, never the victim. Silence encourages the tormentor, never the tormented" -Elie Wiesel
"Stay hungry, stay foolish" - Steve Jobs
"If you put the federal government in charge of the Sahara Desert , in five years ther'ed be a shortage of sand" - Milton Friedman
"The tragedy of modern man is not that he knows less and less about the meaning of his own life, but that it bothers him less and less" - Vaclav Havel
"No se puede controlar el resultado, pero si lo que uno haga para alcanzarlo" - Vitor Belfort [MMA Fighter]
Liborio
A la puerta de la gloria está San Pedro sentado y ve llegar a su lado a un hombre de cierta historia. No consigue hacer memoria y le pregunta con celo: ¿Quién eras allá en el suelo? Era Liborio mi nombre. Has sufrido mucho, hombre, entra, te has ganado el cielo.
Para Raul Castro
Cuba ocupa el penultimo lugar en el mundo en libertad economica solo superada por Corea del Norte.
Cuba ocupa el lugar 147 entre 153 paises evaluados en "Democracia, Mercado y Transparencia 2007"
Cuando vinieron a buscar a los comunistas, Callé: yo no soy comunista. Cuando vinieron a buscar a los sindicalistas, Callé: yo no soy sindicalista. Cuando vinieron a buscar a los judíos, Callé: yo no soy judío. Cuando vinieron a buscar a los católicos, Callé: yo no soy “tan católico”. Cuando vinieron a buscarme a mí, Callé: no había quien me escuchara.
Un sitio donde los hechos y sus huellas nos conmueven o cautivan
CUBA LLORA Y EL MUNDO Y NOSOTROS NO ESCUCHAMOS
Donde esta el Mundo, donde los Democratas, donde los Liberales? El pueblo de Cuba llora y nadie escucha. Donde estan los Green, los Socialdemocratas, los Ricos y los Pobres, los Con Voz y Sin Voz? Cuba llora y nadie escucha. Donde estan el Jet Set, los Reyes y Principes, Patricios y Plebeyos? Cuba desesperada clama por solidaridad. Donde Bob Dylan, donde Martin Luther King, donde Hollywood y sus estrellas? Donde la Middle Class democrata y conservadora, o acaso tambien liberal a ratos? Y Gandhi? Y el Dios de Todos? Donde los Santos y Virgenes; los Dioses de Cristianos, Protestantes, Musulmanes, Budistas, Testigos de Jehova y Adventistas del Septimo Dia. Donde estan Ochun y todas las deidades del Panteon Yoruba que no acuden a nuestro llanto? Donde Juan Pablo II que no exige mas que Cuba se abra al Mundo y que el Mundo se abra a Cuba? Que hacen ahora mismo Alberto de Monaco y el Principe Felipe que no los escuchamos? Donde Madonna, donde Angelina Jolie y sus adoptados around de world; o nos hara falta un Brando erguido en un Oscar por Cuba? Donde Sean Penn? Donde esta la Aristocracia Obrera y los Obreros menos Aristocraticos, donde los Working Class que no estan junto a un pueblo que lanquidece, sufre y llora por la ignominia? Que hacen ahora mismo Zapatero y Rajoy que no los escuchamos, y Harper y Dion, e Hillary y Obama; donde McCain que no los escuchamos? Y los muertos? Y los que estan muriendo? Y los que van a morir? Y los que se lanzan desesperados al mar? Donde estan el minero cantabrico o el pescador de percebes gijonese? Los Canarios donde estan? A los africanos no los oimos, y a los australianos con su acento de hombres duros tampoco. Y aquellos chinos milenarios de Canton que fundaron raices eternas en la Isla? Y que de la Queen Elizabeth y los Lords y Gentlemen? Que hace ahora mismo el combativo Principe Harry que no lo escuchamos? Donde los Rockefellers? Donde los Duponts? Donde Kate Moss? Donde el Presidente de la ONU? Y Solana donde esta? Y los Generales y Doctores? Y los Lam y los Fabelo, y los Sivio y los Fito Paez? Y que de Canseco y Miñoso? Y de los veteranos de Bahia de Cochinos y de los balseros y de los recien llegados? Y Carlos Otero y Susana Perez? Y el Bola, y Pancho Cespedes? Y YO y TU? Y todos nosotros que estamos aqui y alla rumiando frustaciones y resquemores, envidias y sinsabores; autoelogios y nostalgias, en tanto Louis Michel comulga con Perez Roque mientras Biscet y una NACION lanquidecen? Donde Maceo, donde Marti; donde aquel Villena con su carga para matar bribones? Cuba llora y clama y el Mundo NO ESCUCHA!!!
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