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Animal Brains Networked Into Organic Computer ‘Brainet’ [1324]

de System Administrator - martes, 20 de octubre de 2015, 21:23
 

Animal Brains Networked Into Organic Computer ‘Brainet’

By Shelly Fan

Imagine a future where computers no longer run on silicon chips. The replacement?

Brains.

Thanks to two separate studies recently published in Scientific Reports, we may be edging towards that future. In a series of experiments, scientists connected live animal brains into a functional organic computer. The “Brainet”, as they call it, could perform basic computational tasks—and do it better than each animal alone.

“Scientifically and technically, this is brilliantly done,” says Dr. Natasha Kovacevic, a brain-machine interface expert at the Rotman Research Institute who was not involved in the study, to Singularity Hub. “It’s amazing, but also scary that we can use live animals mechanistically as computer chips.”

 

The team, led by Dr. Miguel A. L. Nicolelis from Duke University, has long been pushing the boundaries of brain-machine interfaces—to the point machines are no longer even in the equation. A few years back, they broke ground when they developed a system that allowed monkeys to move a virtual arm with their brain waves alone, and “feel” whatever the digital avatar touched.

The new cutting-edge eschews arms—robotic or virtual—altogether, and goes directly brain-to-brain.

In 2013, Nicolelis and colleagues transferred information between two rat brains with the aid of a brain chip. They trained an “encoder” rat to press one of two potential levers upon seeing an LED light, while they recorded its cortical activity.

Next, the team used the recordings to stimulate the corresponding brain regions of a second rat that wasn’t trained on the task. Impressively this “decoder” rat picked the correct lever over 60% of the time—a result that, while imperfect, suggested it might be feasible to couple animals’ brains together into a network.

Given that wiring multiple processors in parallel speeds up digital computers, the team wondered if forming a Brainet might likewise give biological computers a speed boost.

In the first study, the team implanted arrays of microelectrodes that both record signals and stimulate neurons into the brains of four rats. They then physically hooked the rat brains up using a brain-to-brain interface.

After giving all rats a short zap that acted as a “go” signal, the team monitored their brain waves and rewarded the animals with water if the brain waves oscillated in unison. The purpose? To see whether by synching brains up, subjects might be able to achieve a goal that no single brain can do individually, Nicolelis told Motherboard.

Through many trials over the next 1.5 weeks, the rats learned to synchronize their brain waves at will.

 

In one experiment, a kind of bizarre game of “telephone,” the scientists found they could transmit information sequentially through the Brainet. First, they hooked up three rats, then stimulated the first rat’s brain, recorded the resulting activity, and delivered it to the second rat. Not only did the second ­rat produce a similar brain activity pattern that was further passed down the chain, but the third rat reliably decoded and delivered the pattern back to the first animal, which reported the correct “message” in roughly 35% of the trials—around two times better than how each rat performed when having to do the same four-step task alone.

Essentially, Nicolelis turned rat brains into a meaty artificial network that could classify, store and transfer data. However, no “thinking” in the traditional sense occurred; the animals’ sensory cortices simply functioned like silicon processors.

In a separate study, scientists built upon previous work in the field of neuroprosthetics to see if a Brainet could control a digital arm better than its individual components.

The team implanted a large electrode array into three rhesus monkeys to record their brain activity, and then taught the animals to move a virtual arm in 3D space by picturing the motion in their heads. The monkeys were then given shared control over the arm, with each member in charge of only two out of the three dimensions.

Despite not being physically wired together, the monkeys’ brain activity synchronized, allowing them to match each other’s movement speed and collectively grab a digital ball with ease. The system was also resilient to slackers—even if one member dropped the ball (pun intended) and tuned out momentarily, the other two still managed to perform the task (just far less efficiently).

(Watch a video of the monkey Brainet in action below. The colored dots represent the three monkeys, the black dot is their average, and the circle is the virtual ball.)

Both studies show that when it comes to combining brainpower, 1+1=2.1. The same holds true for humans. When gamers combined their brainwaves through EEG to control a spacecraft simulator in a computer game, they did it better than each person alone.

With increasingly sophisticated devices that stimulate and record the brain non-invasively, it’s not hard to picture the possibility of wiring up human brains to solve thorny problems that baffle individual minds.

In fact, Kovacevic recently crowdsourced EEG data from over 500 volunteers as they collectively played a neurofeedback game at My Virtual Brain, a spectacle that combines science with art and music.

Brainets are certainly intellectually intriguing, Kovacevic acknowledges. Yet privacy and other ethical issues aside, there’s something disturbing about this image, she says. “My main concern is that we, as humans, are losing something of ourselves when we use sentient beings as simple computational tools.”

Just because we can do something, does it mean we should?

“With all due respect, in this case I vote no.”

Image Credit: Katie Zhuang/Nicolelis lab/Duke University

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Animations [711]

de System Administrator - martes, 20 de octubre de 2015, 21:25
 

by Janet Iwasa

How animations can help scientists test a hypothesis

3D animation can bring scientific hypotheses to life. Molecular biologist (and TED Fellow) Janet Iwasa introduces a new open-source animation software designed just for scientists.

Ver Video

0:11 - Take a look at this drawing. Can you tell what it is? I'm a molecular biologist by training, and I've seen a lot of these kinds of drawings. They're usually referred to as a model figure, a drawing that shows how we think a cellular or molecular process occurs. This particular drawing is of a process called clathrin-mediated endocytosis. It's a process by which a molecule can get from the outside of the cell to the inside by getting captured in a bubble or a vesicle that then gets internalized by the cell. There's a problem with this drawing, though, and it's mainly in what it doesn't show. From lots of experiments,from lots of different scientists, we know a lot about what these molecules look like, how they move around in the cell, and that this is all taking place in an incredibly dynamic environment.

1:02 - So in collaboration with a clathrin expert Tomas Kirchhausen, we decided to create a new kind of model figure that showed all of that. So we start outside of the cell. Now we're looking inside. Clathrin are these three-legged molecules that can self-assemble into soccer-ball-like shapes. Through connections with a membrane, clathrin is able to deform the membrane and form this sort of a cup that forms this sort of a bubble, or a vesicle, that's now capturing some of the proteins that were outside of the cell. Proteins are coming in now that basically pinch off this vesicle, making it separate from the rest of the membrane, and now clathrin is basically done with its job, and so proteins are coming in now —we've covered them yellow and orange — that are responsible for taking apart this clathrin cage. And so all of these proteins can get basically recycled and used all over again.

 

Janet Iwasa - Molecular animator - Full bio
 

1:48 - These processes are too small to be seen directly, even with the best microscopes, so animations like this provide a really powerful way of visualizing a hypothesis.

1:59 - Here's another illustration, and this is a drawing of how a researcher might think that the HIV virus gets into and out of cells. And again, this is a vast oversimplification and doesn't begin to show what we actually know about these processes.

2:14 - You might be surprised to know that these simple drawings are the only way that most biologists visualize their molecular hypotheses. Why? Because creating movies of processes as we think they actually occur is really hard. I spent months in Hollywood learning 3D animation software, and I spend months on each animation, and that's just time that most researchers can't afford. The payoffs can be huge, though. Molecular animations are unparalleled in their ability to convey a great deal of informationto broad audiences with extreme accuracy. And I'm working on a new project now called "The Science of HIV" where I'll be animating the entire life cycle of the HIV virus as accurately as possible and all in molecular detail. The animation will feature data from thousands of researchers collected over decades, data on what this virus looks like, how it's able to infect cells in our body, and how therapeutics are helping to combat infection.

3:16 - Over the years, I found that animations aren't just useful for communicating an idea, but they're also really useful for exploring a hypothesis. Biologists for the most part are still using a paper and pencil to visualize the processes they study, and with the data we have now, that's just not good enough anymore. The process of creating an animation can act as a catalyst that allows researchers to crystalize and refine their own ideas. One researcher I worked with who works on the molecular mechanisms of neurodegenerative diseases came up with experiments that were related directly to the animation that she and I worked on together, and in this way, animation can feed back into the research process.

3:56 - I believe that animation can change biology. It can change the way that we communicate with one another, how we explore our data and how we teach our students. But for that change to happen, we need more researchers creating animations, and toward that end, I brought together a team of biologists, animators and programmers to create a new, free, open-source software — we call it Molecular Flipbook — that's created just for biologists just to create molecular animations. From our testing, we've found that it only takes 15 minutes for a biologist who has never touched animation software before to create her first molecular animation of her own hypothesis. We're also building an online database where anyone can view, download and contribute their own animations. We're really excited to announce that the beta version of the molecular animation software toolkit will be available for download today. We are really excited to see what biologists will create with it and what new insights they're able to gain from finally being able to animate their own model figures.

4:59 - Thank you.

5:01 - (Applause)

Link: http://on.ted.com/b0M24

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Ansiedad Anticipatoria [1157]

de System Administrator - domingo, 15 de marzo de 2015, 01:39
 

Ansiedad anticipatoria: síntomas y soluciones a los miedos infundados

por María Dolors Mas Delblanch

David todavía tiembla, sentado en el sofá de mi consulta, cuando me cuenta “estaba sólo en casa, acabándome de preparar. Había quedado con mi novia a las ocho, teníamos que ir a una cena formal con nuestros padres. Mientras me ponía el reloj, de forma automática, miré la hora, eran las ocho y diez y Marta no había llegado.

En ese momento, sin esperarlo, empecé a pensar que, seguramente Marta había tenido un accidente al regresar y que, en cuanto llamaran sería la policía que me pediría  que fuera a reconocerla y…por favor, pensé tantas cosas en un minuto, el corazón me dio un vuelco y empezó a latir fuertemente, me tuve que quitar la corbata porque sudaba profusamente, empecé a ahogarme y a sentirme inestable, como si la visión se volviera borrosa, estaba convencido de que me volvería loco… otro vuelco fue treinta segundos después cuando el timbre sonó y Marta entró sonriente y pidiendo disculpas por haber llegado tarde…

¿Qué me pasó? ¿Cómo lo puedo controlar? Porque me ha vuelto a ocurrir otras veces, ¿me curaré algún día?”

Lo que le ocurrió a David es una situación bastante típica que sucede, también, a muchos otros pacientes y, a la cual llamamos ansiedad aunque, en este caso, le pondremos un “apellido”: anticipatoria. Como ya hemos visto en anteriores artículos en Siquia, llamamos ansiedad a unarespuesta positiva y natural del organismo que sirve para defenderse de una amenaza, ya sea está real o percibida. Sólo si se superan ciertos umbrales de activación, la ansiedad se convierte en una respuesta patológica, que se manifiesta en cuadros de pánico, quedando una elevada parte residual la cual se suele somatizar en el organismo ocasionando síntomas de tipo psicofisiológico, es cuando decimos que el cuerpo, duele, ya que lo hace de una forma totalmente inespecífica, vaga y afectando a diversos órganos y sistemas.

La anticipación está relacionada con imaginar el futuro. Cuando David mira la hora  y ve que pasan diez minutos respecto de la hora de la cita con su novia, empieza a pensar en lo qué le puede haber sucedido. Anticipa que  le debe haber ocurrido algo horrible que haya motivado que no estuviera allí a las ocho, tal y como quedaron. Más tarde, se imagina ya en la situación de que se cumplan sus peores expectativas y por todo lo que debería pasar. Mientras piensa esto su corazón late muy rápido, su respiración es superficial y rápida, comienzan las sensaciones que conducen a una crisis de pánico. Por tanto, como vemos, la función principal de la ansiedad es movilizar al organismo frente a posibles amenazas, reales o percibidas. Sin embargo, cuando hablamos de ansiedad anticipatoria, su función es activar al organismo antes de que este posible peligro ocurra. Es decir, nos advierte. En otras palabras, “quien avisa, no es traidor”… aunque demasiadas veces lo que ocurre es que el peligro es inexistente.

Funciones de la ansiedad anticipatoria

La ansiedad anticipatoria es un proceso de evaluación cognitiva que, teniendo en cuenta la experiencia, entre otras cuestiones, predice las consecuencias que un acontecimiento determinado ( el retraso de Marta, en el ejemplo) produce en la conducta del paciente ( David, en este caso).

  • Evaluación primaria: cómo, cuándo, de qué manera algo perjudica o beneficia al paciente
  • Evaluación secundaria: qué puede hacerse al respecto, por parte del propio paciente
  • Expectativa de eficacia: qué capacidad se atribuye la persona para hacer algo que cambie la situación
  • Expectativa de resultados: qué resultados se calculan como probables para el paciente lo cual produce un estado emocional agradable o desagradable, dependiendo de que el individuo se vea afectado positiva o negativamente.

La anticipación también produce un efecto motivacional. Según Bandura (1986) “los pensamientos anticipatorios que no exceden los límites de la realidad tienen un valor funcional porque motivan el desarrollo de competencias y de planes de acción”. La anticipación es parte de la acción ya que es un factor tanto regulador como inductor de la conducta y emociones.

El pensamiento tiene una importante capacidad de auto-activación fisiológica de la emoción. Las anticipaciones referidas a amenazas, daños o perjuicios, generan ansiedad. Estos pensamientos percibidos, lo cual no significa que sean irreales, pueden resultar tan activadores como los propios eventos reales. Es entonces cuando los pulmones, el corazón, el estómago y los músculos no saben qué ocurre y, por tanto, no toman ninguna decisión que implique una actuación por su parte. Son los centros nerviosos superiores, la corteza cerebral, especialmente, pero no únicamente,  la que presupone nuestra realidad, de forma correcta o incorrecta así como la manera cómo nos está afectando y toma decisiones acerca de lo que podemos hacer. Por tanto, se produce una respuesta psicofisiológica  que será la que permitirá responder al organismo.

Sintomatología de la ansiedad anticipatoria

No se puede menospreciar la importancia de la ansiedad anticipatoria ya que, en contra de lo que algunos puedan pensar, se trata de un problema real que produce una sintomatología absolutamente real. Cuando la mente espera lo peor (“Marta debe haber tenido un accidente”), el cuerpo se prepara para recibir el impacto emocional de una noticia que no recibirá (pero aún no lo sabe, por tanto, tensión, taquicardia…) y la preocupación (“llega 10 minutos tarde y no es habitual en ella, en un día tan importante”), es interpretado por el organismo como una situación peligrosa. Si esta forma de pensar se convierte en habitual, el trastorno tiende a cronificarse.

Por otra parte, además de hacerle sentir angustiado, la ansiedad puede jugar con su estado de ánimo, haciéndole sentir enojado, confundido, desesperanzado irritable o triste, lo cual puede acabar afectando su capacidad de concentración y de toma de decisiones.

La sintomatología física de la ansiedad anticipatoria incluye:

  • Tensión muscular.
  • Sudoración
  • Palpitaciones y/o taquicardia
  • Cefaleas
  • Disnea
  • Voz temblorosa
  • Mareos y náuseas
  • Problemas digestivo
  • Disminuye la capacidad del paciente para concentrarse, lo que puede disminuir su rendimiento.

Los síntomas físicos de la ansiedad anticipatoria pueden ser muy intensos  lo que produce que la persona puede pensar que  está sufriendo un  infarto. Ello es debido a que esté primer ataque de pánico suele ser  repentino e inesperado, pero, sin embargo,  cambia toda la percepción del paciente. Ya que, después de sufrir uno, comienza a sentir una ansiedad anticipatoria constante, debido al miedo a sufrir un segundo, de la misma manera, que les ocurre a los pacientes que padecen fobias o ansiedad específica.

Tratamiento de la ansiedad anticipatoria

En general, podemos decir que hay tres tipos de tratamiento: psicoterapia, farmacológico o una combinación de ambos. De ellos,hablamos un poquito enseguida. Lo más importante es que tanto la ansiedad específica como la anticipatoria, se pueden tratar.

Sin embargo, muchos de los consejos que se dan para tratar la ansiedad específica también funcionan en el caso de la ansiedad anticipatoria. Estos son algunos consejos a tener en cuenta:

1. Cambia tu pensamiento. La ansiedad anticipatoria es una interpretación catastrófica o negativa sobre un resultado desconocido. Aprende a contemplar la existencia de interpretaciones positivas. Dicho de otra forma: cambia tu pensamiento de tipo “profecía autocumplida” ( es decir, predicciones que son las “causantes” de que algo suceda en nuestro pensamiento o, de otra manera, ponernos nosotros mismos la piedra para tropezar a gusto) por pensamientos realistas ( si algo es, es).

2. Ejercicio físico. Porque posee indudables beneficios, a diversos niveles. Distrae, ayuda a quemar calorías, a relajarte y a liberar la adrenalina adicional que se produce cuando te pones ansioso.

3. Distráete. Encontrar alguna actividad agradable puede reducir la ansiedad ya que ocupa su mente, por ejemplo: leer un libro, salir a caminar, ir al cine, entre otras.

4. Aprende técnicas de relajación. Existen técnicas de relajación, respiración, visualización, imaginación, mindfulness, que sólo podrá practicar con su psicólogo y será capaz de reducir su nivel de ansiedad anticipatoria. Con los ejercicios correctos, puedes incluso aprender a calmar una crisis de ansiedad. 

Respecto al tratamiento formal de la ansiedad anticipatoria, muchas veces se recomienda el uso de medicamentos ansiolíoticos para tratar la ansiedad los cuáles pueden ser muy útiles para aliviar los síntomas a corto plazo. Sin embargo- y como ya dijimos en un post anterior- se está produciendo una verdadera adicción a los psicofármacos con escasas ventajas y muchos efectos secundarios, algunos de los cuales son peligrosos para la salud.

La psicoterapia, por su parte, ha demostrado ser bastante eficaz, especialmente, la terapia cognitivo- conductual que ayuda, sobre todo, a cambiar patrones de pensamiento, que es el punto clave para superar la ansiedad anticipatoria.

Para ello, usa varias técnicas como son;:parada de pensamiento, estar en contacto con el aquí y el ahora, visualizar el enfrentamiento a situaciones temidas o hallar que parte hay de realidad y cual de irrealidad en sus anticipaciones de hechos futuros.

Pasos para enfrentarse a lo desconocido e incierto y eliminar la ansiedad anticipatoria

Y, es que en ello consiste, precisamente. Si eres una persona que constantemente te preocupas por lo que va a pasar en el futuro, sea una actividad próxima o tu propio futuro, estás sufriendo posiblemente, un trastorno de ansiedad anticipatoria la cual está relacionada con la intolerancia a la incertidumbre y la necesidad de control. Por ello, se asocia con situaciones en las que la persona tiene elevadas expectativas sobre el propio rendimiento.

La persona repite en su mente, de forma recurrente, escenarios catastróficos en los que todo sale mal. Es decir, presenta un pensamiento negativo, repetido continuamente, lo cual favorece la aparición de las profecías autocumplidas o predicciones causantes de que algo  suceda. Como decíamos un poco antes, son la piedra que nos ponemos con la cual tropezar.

Cómo controlar ansiedad anticipatoria: consejos prácticos

1. Detener el círculo vicioso de las emociones negativas. Casicada pensamiento nos produce una emoción. Por tanto, si llenamos nuestra mente de ideas catastrofistas, estaremos muy ansiosos. Entonces, para interrumpir la ansiedad anticipatoria es necesario descubrir las emociones negativas que esta produce y calmarla. Por ejemplo: respira profundamente y relájate. Cuando creas que vuelves a tener el control sobre tus emociones puedes analizar la situación racionalmente.

2. Descubrir los pensamientos negativos. ¿Qué estás pensando? Puedes escribirlo en un papel. Te darás cuenta de que te centras más en las cosas que pueden salir mal que en los aspectos positivos. Esa es la causa de la ansiedad anticipatoria.

3. Descompone cada pensamiento. Toma los pensamientos, uno a uno, y piensa cuál podría ser el peor escenario que podría ocurrir. ¿Qué puedes esperar en el peor de los casos? ¿Cómo te sentirías? La mayoría de las veces observarás cómo tus respuestas no son tan malas como suponías en un principio y, por tanto, lo que ocurre es que estás magnificando las consecuencias de ese pensamiento y es ello, precisamente, lo que te da miedo.

4. Varía el foco de atención. Llegados a este punto, se observa que necesitas cambiar de actitud, lo cual significa que deberás centrarte en los aspectos positivos. Obviamente, te puede salir mal, pero cómo bien sabes, una actitud positiva mueve montañas. Y, por otra parte, también está claro que sólo con cambiar a un pensamiento positivo, tu problema no habrá terminado.

5. Prepárate para la incertidumbre. En realidad, la vida es bastante incierta y, cuanto antes lo asumas, mejor. Para eliminar la ansiedad anticipatoria es necesario que aprendas a vivir con la incertidumbre sin sentirte incómodo, sino tolerando que está forma parte de tu, -de nuestra- vida. Una buena estrategia es concentrarse en el aquí y el ahora, intentando controlar la tendencia a suponer lo que pasará en el futuro.

En definitiva, la ansiedad anticipatoria consiste en pensar que vamos a sufrir mucho y que pasaremos mucho miedo. Entonces, sentimos miedo por el miedo que creemos que vamos a pasar. De ahí que la expresión “Miedo al miedo” se haya hecho tan popular, hasta el punto de usarse como título para un libro de poesía (de Hernán Narbona), e incluso para el de una canción de hip-hop. La letra del rap que interpretan el grupo Desplante, con Diana Feria, comienza diciendo: “Esto ocurre muchas veces, cuando el temor a temer es más grande que tod

  • Alteraciones de sueño
  • Fatiga

Respecto a la sintomatología psicosocial, hallamos:

  • Problemas en las relaciones interpersonales, ya que los pacientes están constantemente tensos y preocupados, a veces, sin una razón aparente.o aquello en lo que crees…”.

Deja tu consulta a la psicóloga Dolors Mas o, si quieres más info, mirá como te ayudamos a través del equipo de psicólogos online de Siquia.

Sobre la autora de este artículo

María Dolors Mas Delblanch es psicóloga en Badalona con Nº Colegiada 17222. Sus especialidades son la ansiedad, la depresión y el TDAH. Atienda a parejas y a madres y padres con dudas sobre la crianza de sus hijos. Puedes leer más artículos de estas temáticas firmadas por la psicóloga en Siquia y dejarle tu consulta.

Link: http://www.siquia.com

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Ansiedad: Comentarios sobre las historias personales asociadas a ella [1145]

de System Administrator - martes, 10 de marzo de 2015, 23:30
 

Ansiedad: Comentarios sobre las historias personales asociadas a ella

por Héctor Gamba-Collazos | Universidad Manuela Beltrán

Acudiendo a la noción de narración, el texto busca hacer una reflexión sobre las experiencias de ansiedad, para ello inicialmente se destaca que el concepto no puede ser considerado en sí mismo como un problema o como una patología ya que, por el contrario, hace referencia a un conjunto de reacciones que tiene gran valor adaptativo puesto que prepara al sujeto para enfrentar una amenaza. Posteriormente, se resalta que las experiencias de ansiedad no se restringen al nivel fisiológico, sino que están asociadas con una narración particular que, por ejemplo, gira alrededor de las amenazas ambientales y la insuficiencia personal en los casos en los que la ansiedad se torna problemática Con lo anterior, se concluye que el concepto no hace referencia a un padecimiento del que el sujeto es víctima, sino a una experiencia en la que el individuo es un agente activo con un repertorio de acciones que se adopta y mantiene en función de la historia personal construida.

Por favor lea el PDF adjunto.

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Antioxidants Facilitate Melanoma Metastasis [1492]

de System Administrator - jueves, 8 de octubre de 2015, 13:02
 

Vitamin C, an antioxidant | C. BICKEL, SCIENCE TRANSLATIONAL MEDICINE

Antioxidants Facilitate Melanoma Metastasis

By Anna Azvolinsky

Two compounds boost the ability of melanoma cells to invade other tissues in mice, providing additional evidence that antioxidants can be beneficial to malignant cells as well as healthy ones.

Antioxidants decrease the levels of DNA-damaging, cancer-causing reactive oxygen species (ROS) that are formed during normal metabolism. Yet clinical trials that evaluated the health benefits of antioxidants like vitamin E and beta carotene have not found that these supplements can prevent cancer; some have even demonstrated an uptick in cancer risk associated with antioxidant supplementation.  

A team of researchers at the University of Gothenburg in Sweden has now shown that mice with melanoma fed an antioxidant had double the number of lymph node metastases and more malignant disease compared to animals with the same cancer who were not given antioxidants. The results, published today (October 7) in Science Translational Medicine, provide further evidence that antioxidants are likely not beneficial to the health of those with melanoma and other tumors and could, in fact, be harmful.

“Metastasis is really the most dangerous part of a cancer so we believe that melanoma patients and those who have an increased risk of this disease should be aware of the potential harm of antioxidants,” study coauthor Martin Bergo told The Scientist.

“This is a carefully designed, well-controlled, and beautifully executed study,” Dimitrios Anastasiou, who studies cancer metabolism at the U.K.’s Francis Crick Institute wrote in an email. “Antioxidants are easily accessible to the wider public . . . making them susceptible to potential misuse. These findings highlight the need for further robust studies that aim to clarify in which context antioxidants should be used or avoided.”

In January 2014, the Swedish group showed that antioxidants can accelerate the growth of primary lung tumors. For the present study, the researchers fed mice with early-stage malignant melanoma the antioxidant N-acetylcysteine (NAC). The researchers found that the sizes and number of primary melanoma tumors were the same between the control mice and the animals given antioxidants. But the latter group had twice as many lymph-node metastases “and when we looked inside the lymph nodes, those in the antioxidant-treated group contained more malignant cells,” said Bergo.

The team observed similar results working with cultured human melanoma cell lines. Adding either NAC or another antioxidant—a soluble vitamin E analog—to the culture didn’t affect the cells’ proliferation, but did increase their migration abilities and invasive properties. These properties were dependent on the production of glutathione, an antioxidant endogenous to cells.

Unlike the lung cancer study, which showed the antioxidants worked by reducing the activity of tumor suppressor p53, in the melanoma experiments, the antioxidants appeared to work by increasing the levels of reduced glutathione—which neutralizes ROS—and increasing levels of rhoA, an enzyme activated during cell migration and invasion. Combined, the results of both studies suggest that antioxidants can accelerate cancer progression through two apparently different mechanisms.

In an email, melanoma researcher Meenhard Herlyn of the Wistar Institute in Philadelphia noted that there’s more to learn about how antioxidants might affect people with melanoma. “Certainly the use of vitamin E and its analogs should be reconsidered if patients have already been diagnosed with a tumor,” he wrote.

While ROS can damage cells when present at high levels, they also help protect cells, including through the reversible oxidation of proteins, explained Anastasiou. “Various mechanisms exist to ensure that ROS levels are carefully balanced. Antioxidants may interfere with this balance, either within the tumor or its microenvironment, potentially disrupting regulatory pathways controlled by ROS,” he wrote in an email.

Bergo’s team will next test whether topical application of antioxidants—such as those found in lotions and sunscreens—have a similar effect on established melanoma tumors.

“Antioxidants can probably protect both healthy cells and tumor cells from free radical,” said Bergo noted. “Free radicals can slow down tumor proliferation and metastasis and antioxidants can help tumors overcome those limitations.”

“The challenges will be to understand how generally applicable are these observations to other tumor types and to translate these findings into clinically useful dietary guidelines,” noted Anastasiou.

K. Le Gal et al., “Antioxidants can increase melanoma metastasis in mice,” Science Translational Medicine, doi:10.1126/scitranslmed.aad3740, 2015.

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Application of Genetically Humanized Mouse Models for Biomedical Research [989]

de System Administrator - miércoles, 12 de noviembre de 2014, 14:03
 

 

The Advantage and Application of Genetically Humanized Mouse Models for Biomedical Research

The use of genetically engineered mice in experimental medical research has led to significant advances in our understanding of human health and disease. 

From the development of transgenic and gene targeting methods to recent innovations in gene-editing technologies, manipulation of the mouse genome has become increasingly sophisticated.

This white paper discusses the available technologies used in the generation of genetically humanized mice and the favored applications of these models in biomedical research.

>> Download This White Paper to Learn: 

  • Transgenic Technologies
  • Types of DNA Vectors for Humanization
  • How to Apply Genetically Humanized Models in:
    • Efficacy and Safety Testing of Therapeutic Compounds and Biologics
    • Drug Metabolism and Disposition
    • Novel Therapeutic Approaches In Vivo
    • The Immune System

Please read the attached whitepaper.

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APRENDA A ORGANIZAR SUS ACTIVIDADES [893]

de System Administrator - viernes, 26 de septiembre de 2014, 13:16
 
FOLLETO:

APRENDA A ORGANIZAR SUS ACTIVIDADES

por Servicio Andaluz de Salud

Este folleto, elaborado por el Servicio Andaluz de Salud, pretende ser una herramienta más de apoyo dirigida a aquellas personas que cursan depresión, algún tipo de trastorno de ansiedad, o que por cualquier razón tengan problemas en la organización de sus actividades. En este sencillo folleto encontraremos consejos útiles, así como un plan diario de actividades simple pero muy eficaz.

Continúa en el folleto adjunto.

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Are People in Silicon Valley Just Smarter? [1247]

de System Administrator - miércoles, 17 de junio de 2015, 10:25
 

Are People in Silicon Valley Just Smarter?

BY PETER DIAMANDIS

Why is Silicon Valley better at innovating than most of the world? Why are the number of successful startups so high there? Where is the next Mecca of tech-startup success going to emerge?

This post is about where and why innovation happens, and where it's going next.

It Started in a Coffee Shop

In the 18th century, coffeehouses had an enormous impact on Enlightenment culture.

As Steven Johnson says in his book Where Good Ideas Come From, "It's no accident that the Age of Reason accompanies the rise of caffeinated beverages."

The coffeehouse became the hub for information sharing.

Suddenly, commoners could interact with the royals, meet, mingle and share ideas.

In his book London Coffee Houses, Bryant Lillywhite explains it this way:

"The London coffee-houses provided a gathering place where, for a penny admission charge, any man who was reasonably dressed could smoke his long, clay pipe, sip a dish of coffee, read the newsletters of the day, or enter into conversation with other patrons.

"At the period when journalism was in its infancy and the postal system was unorganized and irregular, the coffeehouse provided a centre of communication for news and information . . . Naturally, this dissemination of news led to the dissemination of ideas, and the coffee-house served as a forum for their discussion."

Beyond the Coffee Shop

Today, researchers have recognized that the coffee-shop phenomenon is actually just a mirror of what occurs when people move from sparse rural areas to jam-packed cities.

As people begin living atop one another, so too do their ideas. And, as Matt Ridley aptly describes, innovation happens when these crowded ideas "have sex."

Geoffrey West, a physicist from Santa Fe Institute, found that when a city's population doubles, there is a 15 percent increase in income, wealth and innovation. (He measured innovation by counting the number of new patents.)

Why Silicon Valley Is Getting It Right

My friend Philip Rosedale, the creator of Second Life and now CEO of High Fidelity, spent some time investigating why the Bay Area in particular has become such a hub for technology and innovation.

As Rosedale explains, "I think the magic of Silicon Valley is not in fostering risk-taking, but instead in making it safe to work on risky things...There are two things happening in Silicon Valley that are qualitatively different than anywhere else."

Those things are:

  1. The sheer density of tech “founders per capita” is 10 times greater than the norm for other cities (see figure below).
  2. There is a far greater level of information sharing between entrepreneurs.

Image: San Francisco has about twice the density of the next-highest city (Boston), and about five times the density of New York.

Rosedale goes on, "You can't walk down the street without (almost literally) running into someone else who is starting a tech company. While tech ventures are individually risky, a sufficiently large number of them close to each other makes the experience of working in startups safe for any one individual."

"I like to visualize this as a series of lily pads in a pond, occasionally submerging as their funding runs out," he explains. "If you are a frog, and there are enough other lily pads nearby, you'll do just fine."

"Beyond simply having a lot of people near you to work with, I believe that the openness and willingness to share inherent to Silicon Valley is a big driver in this effect."

Beyond the Next Coffee House

For entrepreneurial technology innovation to occur, you need two things: a densely packed population of tech-savvy entrepreneurs and a culture of freely sharing and building on ideas.

Rosedale, who is working on the key technologies to intimately and powerfully connect people using virtual worlds, points out, "If we create a virtual world, we can expect a sudden disruption as the biggest 'city' of the tech future goes 100 percent online."

Just as the coffeehouse is a pale comparison to today's high-density city, so too will today's city be a pale comparison to the coming high fidelity, virtual online innovation communities.

Imagine a near-term future where any entrepreneur, anywhere on the planet, independent of the language they speak (think instant translation), can grab their VR headset (e.g., Oculus, Hololens, Magic Leap) and immerse themselves in an extremely high-resolution and low-latency VR world filled with like-minded, creative, insightful and experienced entrepreneurs.

But this hyperconnected world is not happening in isolation from other changes.

As I've noted in previous posts, the number of people connected to the Internet is exploding, going from 1.8 billion in 2010 to 2.8 billion today, and as many as 5 billion by 2020.

The opportunities for collaborative thinking are growing exponentially, and since progress is cumulative, the resulting innovations are going to grow exponentially as well.

Ultimately, these virtual worlds will create massive, global virtual coffeehouses for entrepreneurs to meet, to innovate, to create businesses and solve problems.

It's for this reason (among many others) that I believe we are living during the most exciting time ever.

The tools we are developing will bring about an age of abundance, and we will be able to meet the needs of every man, woman and child on Earth.

Image Credit: Impact Hub/Flickr

 

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Aristotelian Biology [894]

de System Administrator - viernes, 26 de septiembre de 2014, 14:09
 

Aristotelian Biology

The ancient Greek philosopher was the first scientist.

By Armand Marie Leroi

In the Aegean Sea there is an island called Lesbos. It has pine-forested mountains, glades of chestnut trees, and valleys filled with blooming rhododendrons. Terrapins and eels navigate the rivers. In the spring and autumn, migrating birds pause there in the thousands as they travel between Africa and Europe.

And there is the Lagoon. Twenty-two kilometers long, 10 wide, Kolpos Kallonis nearly cuts the island in two. The richest body of water in the Aegean, it is famous for its pilchards, which are best eaten raw, washed down with ouzo. I first went to the Lagoon more than 10 years ago, but have returned many times since. I have done so because it was on its shores that my science—biology—was born.

Around 345 BC, Aristotle left Athens, where for 20 years he had studied and taught at Plato’s Academy. He traveled east, across the Aegean, married, and settled on Lesbos for three years. D’Arcy Thompson, the Scottish zoologist and Aristotle scholar, said it was the “honeymoon of his life.” It was there that Aristotle began to study the natural world and so turned himself into not merely the first biologist, but the first scientist. Other philosophers before him had speculated about the causes of the natural world, but he was the first to combine theory with empirical investigation.

Aristotle’s philosophical works, such as Metaphysics, Politics, Poetics, and his logical treatises loom over the history of Western thought like a mountain range. But he devoted nearly a third of his writings—a dozen volumes, thousands of pages—to living things. There is comparative zoology in Historia animalium, functional anatomy in The Parts of Animals, a book on growth, two on animal locomotion, and two on aging and death. There were books on plants, too, but they have been lost.

And then there is his greatest work of all. The Generation of Animals described how animals develop in the egg and womb and outlined a theory of inheritance. It was the best one around until the day, 2,300 years later, when Gregor Mendel published his “Experiments on Plant Hybridization.” Aristotle underpinned his biology with a physical and chemical theory and a scientific method that lies atop metaphysical bedrock. There’s a sense in which his entire philosophy was constructed in order to study living things.

Aristotle’s books are lecture notes for an epic biology course. They’re a hard read: terse and riddled with unfamiliar terms. He talks of the “soul” and you think of some mystical, immaterial substance that survives our mortal frames. But that’s Aquinas’s soul, not Aristotle’s: his soul is pure physiology. It’s the system that keeps us, and every living thing, alive. Taken together, I think that Aristotle’s biology is the greatest scientific edifice ever built by a single man. I’ll allow one challenger. And that is only because Charles Darwin gave us the idea that eluded Aristotle: evolution.

Aristotle’s biology is all but forgotten. It was the principal casualty of the Scientific Revolution. He was the giant who had to be slain so that we could pass through the gates of philosophy to reach the green fields of science that lay beyond. And yet, if, as a biologist, you read him, you realize how familiar it all seems—how so many of our ideas were first his.

But that’s no reason to read him. True, Max Delbrück said that Aristotle deserved a Nobel for having the idea of DNA—but that was just an affectionate joke. No, we should read him not for his science but for his example. He shows us how to transcend the ideas and theories that constrain our thoughts. He went down to the Lagoon’s shore, picked up a snail, and asked, “What’s inside?” It’s such a simple question, but it launched a science vast and beautiful. And that is what Aristotle gives us: the courage to seek and discover new worlds.

Armand Marie Leroi is a professor of evolutionary developmental biology at Imperial College London. Read an excerpt of The Lagoon: How Aristotle Invented Science.

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Arte [681]

de System Administrator - martes, 5 de agosto de 2014, 00:45
 

Video: Las Reglas Ocultas del Arte [681]


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