quinta-feira, 2 de outubro de 2014

Hospitals with aggressive treatment styles had lower failure-to-rescue rates

 


Hospitals with aggressive treatment styles, also known as high hospital care intensity (HCI), had lower rates of patients dying from a major complication (failure to rescue) but longer hospitalizations, writes Kyle H. Sheetz, M.D., M.S., of the Center for Healthcare Outcomes and Policy, Ann Arbor, Mich., and colleagues.

The intensity of medical care varies around the country. Intensity is synonymous with an aggressive treatment style and it has been implicated in rising health care costs, especially during the end-of-life period. Inpatient surgery also is a cost burden. The authors analyzed national Medicare data to examine increased HCI and outcomes after major surgery.

The data identified 706,520 patients at 2,544 hospitals who underwent 1 of 7 major cardiovascular, orthopedic or general surgical operations. The Dartmouth Atlas provides metrics of health care intensity for Medicare beneficiaries in their last two years of life.

Patients who had surgery at high HCI vs. low HCI hospitals had increased major complication rates. However, patients who had surgery at high HCI hospitals were 5 percent less likely to die of a major complication (failure to rescue) than at a low HCI facility. However, patients treated at high-HCI hospitals had longer hospitalizations, more inpatient deaths and lower hospice use during the final two years of life.

"Hospital care intensity has an independent influence on established quality metrics for surgical care, although its ability to improve quality through direct augmentation appears limited."


Story Source:

The above story is based on materials provided by The JAMA Network Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kyle H. Sheetz, Justin B. Dimick, Amir A. Ghaferi. The Association Between Hospital Care Intensity and Surgical Outcomes in Medicare Patients. JAMA Surgery, 2014; DOI: 10.1001/jamasurg.2014.552

 

Ethical filament: Can fair trade plastic save people and the planet?

 

October 1, 2014

Michigan Technological University

It’s old news that open-source 3-D printing is cheaper than conventional manufacturing, not to mention greener and incredibly useful for making everything from lab equipment to chess pieces. Now it’s time add another star to the 3-D printing constellation. It may help lift some of the world’s most destitute people from poverty while cleaning up a major blight on the earth and its oceans: plastic trash.


Waste pickers in the developing world barely eke out a living scouring landfills for trash to sell. They usually don't bother with plastic, however, because it has almost no value. But thanks to an emerging market, waste plastic may soon be a more alluring target; it can serve as a feedstock for 3D printer filament.

It's old news that open-source 3D printing is cheaper than conventional manufacturing, not to mention greener and incredibly useful for making everything from lab equipment to chess pieces. Now it's time add another star to the 3D printing constellation. It may help lift some of the world's most destitute people from poverty while cleaning up a major blight on Earth and its oceans: plastic trash.

At the center of the movement is a new set of standards inspired by fair trade products ranging from diamonds to chocolate.

"We are creating a new class of material called ethical 3D printing filament, like fair trade coffee," said Joshua Pearce of Michigan Technological University. "It's a way to help the poorest of the poor up the economic ladder."

Waste pickers in the developing world barely eke out a living scouring landfills for trash to sell. They usually don't bother with plastic, however, because it has almost no value.

But thanks to an emerging market, waste plastic may soon be a more alluring target; it can serve as a feedstock for 3D printer filament. What makes it especially attractive is the cost of conventional filament made from virgin plastic: about $35 to $50 a kilogram.

Pearce's group has already developed a recyclebot that turns milk jugs and other plastic trash into filament for pennies on the dollar. And next-generation commercial-grade recyclebots are creating opportunities for businesses. But for waste pickers to truly benefit, Pearce says, the recycled filament industry will need to adhere to certain fair labor and environmental practices.

Here's how it would work. Under fair trade standards for ethical 3D printing filament, manufacturers would guarantee that their enterprise meets certain conditions, which Pearce and his colleagues published in the Journal of Sustainable Development. They include the following:

• minimum pricing to assure that workers receive fair wages • a fair-trade premium added to the filament's price that supports development projects • a regular work week of 48 hours and a ban on child labor and forced labor • environmentally conscious manufacturing practices • safeguards for workers' health and safety • the right to unionize • a ban on discrimination and sexual and physical harassment

Businesses that make or use ethical filament could charge a premium for their product, though it would still cost less than conventional 3D filament. "Filament prices are so high that places like Protoprint and Plastic Bank could sell their filament at half that price and still give pickers a living wage while doing good for the environment," said Pearce.

Protoprint, a 3D printing firm in Pune, India, is collaborating with techfortrade. The London-based nonprofit harnesses technology to eliminate poverty through economic development. After working with Pearce, techfortrade plans to fully implement his fair trade standards for filament in the Ethical Filament Foundation.

"Joshua's knowledge and his passion, plus his open, collaborative approach, persuaded us that his ethical filament standards would do for 3D printer filament what Fair Trade did for coffee," said William Hoyle, CEO of techfortrade. "We're now close to making this idea a reality; Protoprint is planning to make the first ethical filament offering available in January, and our other ventures in Latin America will follow."

The paper on fair trade filament, "Evaluation of Potential Fair Trade Standards for an Ethical 3D Printing Filament," is coauthored by Pearce, Savanna R. Feeley of Michigan State University and Bas Wijnen, a PhD candidate in materials science and engineering at Michigan Tech and published this month in the Journal of Sustainable Development.


Story Source:

The above story is based on materials provided by Michigan Technological University. The original article was written by Marcia Goodrich. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. R. Feeley, Bas Wijnen, Joshua M. Pearce. Evaluation of Potential Fair Trade Standards for an Ethical 3-D Printing Filament. Journal of Sustainable Development, 2014; 7 (5) DOI: 10.5539/jsd.v7n5p1

 

Novel approach to magnetic measurements atom-by-atom

 

October 1, 2014

Uppsala Universitet  

Having the possibility to measure magnetic properties of materials at atomic precision is one of the important goals of today's experimental physics. Such measurement technique would give engineers and physicists an ultimate handle over magnetic properties of nano-structures for future applications. Researchers now propose a new method, utilizing properties of the quantum world – the phase of the electron beam – to detect magnetism with atom-by-atom precision.


Having the possibility to measure magnetic properties of materials at atomic precision is one of the important goals of today's experimental physics. Such measurement technique would give engineers and physicists an ultimate handle over magnetic properties of nano-structures for future applications. In an article published in Physical Review Letters researchers propose a new method, utilizing properties of the quantum world -- the phase of the electron beam -- to detect magnetism with atom-by-atom precision.

The electron microscope is a fascinating instrument. It uses a highly accelerated electron beam, which passes right through the sample. The way how the beam scatters in that process, gives scientists a whole lot of information about the sample itself. Today it allows us to watch individual atoms and distinguish them by their atomic number. Scientists even learned how to extract a position of every single atom in a nanoparticle. Much of this became possible thanks to the invention of an aberration corrector -- a device, which sharpens the image of microscope, the same way as glasses help our eyes.

There is however one domain, where microscopy is still relatively in its beginnings and that is the study of magnetic properties. A team of three scientists, Jan Rusz from Uppsala University, Sweden, Juan-Carlos Idrobo from Oak Ridge National Laboratory, USA, and Somnath Bhowmick from Indian Institute of Technology, India, have proposed a new way, which should bring the resolution in magnetic studies on par with watching individual atoms.

The trick lies in an inovative use of the aberration corrector -- "the glasses of the microscope." It is used to correct all errors of the microscope optics, except for one specific distortion, which is tuned to the symmetry of the measured crystal. Imagine your glasses intentionally curved in a specific way, which allows you to see something, that you could not spot before. In the strange world of quantum mechanics this is exactly what happens. The distortion enhances the magnetic signal, which can be then easily measured.

- With this new method, we bring the atomic resolution magnetic measurements to about 400 laboratories world-wide, which are equipped with modern scanning transmission electron microscopes with aberration correctors, says Jan Rusz, and expects that the first experimental confirmations will come very soon.


Story Source:

The above story is based on materials provided by Uppsala Universitet. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ján Rusz, Juan-Carlos Idrobo, Somnath Bhowmick. Achieving Atomic Resolution Magnetic Dichroism by Controlling the Phase Symmetry of an Electron Probe. Physical Review Letters, 2014; 113 (14) DOI: 10.1103/PhysRevLett.113.145501

 

Mantis shrimp's eyes inspire new cancer-detecting camera

 

The complex eyes of the mantis shrimp are inspiring new cameras that can detect cancer and...

The complex eyes of the mantis shrimp are inspiring new cameras that can detect cancer and visualize brain activity (Photo: Roy Caldwell)

One of nature’s most notorious psychopaths may be giving cancer patients new hope. The mantis shrimp is famous for having a punch like a .22 bullet and a perpetual bad attitude, but it also has the most complex eyes in the animal kingdom, which are excellent at detecting polarized light. With this in mind, researchers at the University of Queensland (UQ) are developing new cameras based on the mantis shrimp’s eyes that can detect a variety of cancer tissues.

Polarized light is a non-invasive way of detecting cancers because cancerous tissue reflects light differently from normal tissue. The problem is, the human eye can’t see polarized light and, though cameras that detect polarized light are already being used for detecting cancer, they still leave a lot to be desired. However, the mantis shrimp may help give the technology a major boost because its eyes are better at handling polarized light than anything man made.

The mantis shrimp already boasts a formidable armory of traits. It has an extremely tough mantle that has inspired a new generation of body armor, deadly claws with a supersonic punch, and a reputation for responding to most situations by belting someone or something. However, its eyes are in a league by themselves.

The mantis shrimp’s eye consists of two flattened hemispheres split into three regions, with the central band crowded with specialized receptors. This means that each eye possesses trinocular vision and depth perception. In addition, the mantis shrimp has 16 different photoreceptor pigments with 12 reserved for color sensitivity and the others for color filtering.

What this means is that the mantis shrimp has shellfish super vision. Where humans can see only three colors, the mantis shrimp can effectively see nine more colors than we can. Also, it can see both polarized light and multispectral images because each of the 10 thousand individual photocells, called ommatidia, found in eye eye has a pigment cell for color vision and an array of microvilli that perform as extremely efficient polarization filters.

"Humans can’t see [cancerous tissue surrounded by healthy tissue], but a mantis shrimp could walk up to it and hit it," says Professor Justin Marshall, from the Queensland Brain Institute at UQ. "We see color with hues and shades, and objects that contrast – a red apple in a green tree for example – but our research is revealing a number of animals that use polarized light to detect and discriminate between objects. The camera that we've developed in close collaboration with US and UK scientists shoots video and could provide immediate feedback on detecting cancer and monitoring the activity of exposed nerve cells. It converts the invisible messages into colors that our visual system is comfortable with."

Marshall says that when perfected, the technology could even be adapted to smartphones for self-diagnosis, allowing patients to monitor their own condition, which would free up scarce medical resources. In addition, the ability of the mantis shrimp camera to see nerve cell activity could make it a new tool for neuroscience.

The UQ research was published in IEEE.

Source: University of Queensland

 

Paint on 'smart' bandage emits phosphorescent glow for healing below

 


The transparent liquid bandage displays a quantitative, oxygenation-sensitive colormap that can be easily acquired using a simple camera or smartphone.

Inspired by a desire to help wounded soldiers, an international, multidisciplinary team of researchers led by Assistant Professor Conor L. Evans at the Wellman Center for Photomedicine of Massachusetts General Hospital (MGH) and Harvard Medical School (HMS) has created a paint-on, see-through, "smart" bandage that glows to indicate a wound's tissue oxygenation concentration. Because oxygen plays a critical role in healing, mapping these levels in severe wounds and burns can help to significantly improve the success of surgeries to restore limbs and physical functions. The work was published today in The Optical Society's (OSA) open-access journal Biomedical Optics Express.

"Information about tissue oxygenation is clinically relevant but is often inaccessible due to a lack of accurate or noninvasive measurements," explained lead author Zongxi Li, an HMS research fellow on Evans' team.

Now, the "smart" bandage developed by the team provides direct, noninvasive measurement of tissue oxygenation by combining three simple, compact and inexpensive components: a bright sensor molecule with a long phosphorescence lifetime and appropriate dynamic range; a bandage material compatible with the sensor molecule that conforms to the skin's surface to form an airtight seal; and an imaging device capable of capturing the oxygen-dependent signals from the bandage with high signal-to-noise ratio.

This work is part of the team's long-term program "to develop a Sensing, Monitoring And Release of Therapeutics (SMART) bandage for improved care of patients with acute or chronic wounds," says Evans, senior author on the Biomedical Optics Express paper.

How exactly does a 'smart' bandage work?

For starters, the bandage's not-so-secret key ingredient is phosphors -- molecules that absorb light and then emit it via a process known as phosphorescence.

Phosphorescence is encountered by many on a daily basis -- ranging from glow-in-the-dark dials on watches to t-shirt lettering. "How brightly our phosphorescent molecules emit light depends on how much oxygen is present," said Li. "As the concentration of oxygen is reduced, the phosphors glow both longer and more brightly." To make the bandage simple to interpret, the team also incorporated a green oxygen-insensitive reference dye, so that changes in tissue oxygenation are displayed as a green-to-red colormap.

The bandage is applied by "painting" it onto the skin's surface as a viscous liquid, which dries to a solid thin film within a minute. Once the first layer has dried, a transparent barrier layer is then applied atop it to protect the film and slow the rate of oxygen exchange between the bandage and room air -- making the bandage sensitive to the oxygen within tissue.

The final piece involves a camera-based readout device, which performs two functions: it provides a burst of excitation light that triggers the emission of the phosphors inside the bandage, and then it records the phosphors' emission. "Depending on the camera's configuration, we can measure either the brightness or color of the emitted light across the bandage or the change in brightness over time," Li said. "Both of these signals can be used to create an oxygenation map." The emitted light from the bandage is bright enough that it can be acquired using a regular camera or smartphone -- opening the possibility to a portable, field-ready device.

Immediate applications and future goals

Immediate applications for the oxygen-sensing bandage include monitoring patients with a risk of developing ischemic (restricted blood supply) conditions, postoperative monitoring of skin grafts or flaps, and burn-depth determination as a guide for surgical debridement -- the removal of dead or damaged tissue from the body.

"The need for a reliable, accurate and easy-to-use method of rapid assessment of blood flow to the skin for patients remains a clinical necessity," said co-author Samuel Lin, an HMS associate professor of surgery at Beth Israel Deaconess Medical Center. "Plastic surgeons continuously monitor the state of blood flow to the skin, so the liquid-bandage oxygenation sensor is an exciting step toward improving patient care within the realm of vascular blood flow examination of the skin."

What's the next step for the bandage? "We're developing brighter sensor molecules to improve the bandage's oxygen sensing efficiency," said Emmanuel Roussakis, another research fellow in Evans' laboratory and co-author, who is leading the sensor development effort. The team's laboratory research will also focus on expanding the sensing capability of the bandage to other treatment-related parameters -- such as pH, bacterial load, oxidative states and specific disease markers -- and incorporating an on-demand drug release capacity.

"In the future, our goal for the bandage is to incorporate therapeutic release capabilities that allow for on-demand drug administration at a desired location," says Evans. "It allows for the visual assessment of the wound bed, so treatment-related wound parameters are readily accessible without the need for bandage removal -- preventing unnecessary wound disruption and reducing the chance for bacterial infection."

Beyond the lab, the team's aim is to move this technology from the bench to the bedside, so they are actively searching for industry partners. They acknowledge research support from the Military Medical Photonics Program from the U.S. Department of Defense, and National Institutes of Health.


Story Source:

The above story is based on materials provided by The Optical Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zongxi Li, Emmanuel Roussakis, Pieter G. L. Koolen, Ahmed M. S. Ibrahim, Kuylhee Kim, Lloyd F. Rose, Jesse Wu, Alexander J. Nichols, Yunjung Baek, Reginald Birngruber, Gabriela Apiou-Sbirlea, Robina Matyal, Thomas Huang, Rodney Chan, Samuel J. Lin, and Conor L. Evans. Non-invasive transdermal two-dimensional mapping of cutaneous oxygenation with a rapid-drying liquid bandage. Biomed. Opt. Express, 5, 3748-3764 (2014) [link]

 

New drug-delivery capsule may replace injections

 


A schematic drawing of a microneedle pill with hollow needles. When the pill reaches the desired location in the digestive tract, the pH-sensitive coating surrounding the capsule dissolves, allowing the drug to be released through the microneedles.

Given a choice, most patients would prefer to take a drug orally instead of getting an injection. Unfortunately, many drugs, especially those made from large proteins, cannot be given as a pill because they get broken down in the stomach before they can be absorbed.

To help overcome that obstacle, researchers at MIT and Massachusetts General Hospital (MGH) have devised a novel drug capsule coated with tiny needles that can inject drugs directly into the lining of the stomach after the capsule is swallowed. In animal studies, the team found that the capsule delivered insulin more efficiently than injection under the skin, and there were no harmful side effects as the capsule passed through the digestive system.

"This could be a way that the patient can circumvent the need to have an infusion or subcutaneous administration of a drug," says Giovanni Traverso, a research fellow at MIT's Koch Institute for Integrative Cancer Research, a gastroenterologist at MGH, and one of the lead authors of the paper, which appears in the Journal of Pharmaceutical Sciences.

Although the researchers tested their capsule with insulin, they anticipate that it would be most useful for delivering biopharmaceuticals such as antibodies, which are used to treat cancer and autoimmune disorders like arthritis and Crohn's disease. This class of drugs, known as "biologics," also includes vaccines, recombinant DNA, and RNA.

"The large size of these biologic drugs makes them nonabsorbable. And before they even would be absorbed, they're degraded in your GI tract by acids and enzymes that just eat up the molecules and make them inactive," says Carl Schoellhammer, a graduate student in chemical engineering and a lead author of the paper.

Safe and effective delivery

Scientists have tried designing microparticles and nanoparticles that can deliver biologics, but such particles are expensive to produce and require a new version to be engineered for each drug.

Schoellhammer, Traverso, and their colleagues set out to design a capsule that would serve as a platform for the delivery of a wide range of therapeutics, prevent degradation of the drugs, and inject the payload directly into the lining of the GI tract. Their prototype acrylic capsule, 2 centimeters long and 1 centimeter in diameter, includes a reservoir for the drug and is coated with hollow, stainless steel needles about 5 millimeters long.

Previous studies of accidental ingestion of sharp objects in human patients have suggested that it could be safe to swallow a capsule coated with short needles. Because there are no pain receptors in the GI tract, patients would not feel any pain from the drug injection.

To test whether this type of capsule could allow safe and effective drug delivery, the researchers tested it in pigs, with insulin as the drug payload. It took more than a week for the capsules to move through the entire digestive tract, and the researchers found no traces of tissue damage, supporting the potential safety of this novel approach.

They also found that the microneedles successfully injected insulin into the lining of the stomach, small intestine, and colon, causing the animals' blood glucose levels to drop. This reduction in blood glucose was faster and larger than the drop seen when the same amount of glucose was given by subcutaneous injection.

"The kinetics are much better, and much faster-onset, than those seen with traditional under-the-skin administration," Traverso says. "For molecules that are particularly difficult to absorb, this would be a way of actually administering them at much higher efficiency."

"This is a very interesting approach," says Samir Mitragotri, a professor of chemical engineering at the University of California at Santa Barbara who was not involved in the research. "Oral delivery of drugs is a major challenge, especially for protein drugs. There is tremendous motivation on various fronts for finding other ways to deliver drugs without using the standard needle and syringe."

Further optimization

This approach could also be used to administer vaccines that normally have to be injected, the researchers say.

The team now plans to modify the capsule so that peristalsis, or contractions of the digestive tract, would slowly squeeze the drug out of the capsule as it travels through the tract. They are also working on capsules with needles made of degradable polymers and sugar that would break off and become embedded in the gut lining, where they would slowly disintegrate and release the drug. This would further minimize any safety concern.

 

 

Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Anne Trafton. Note: Materials may be edited for content and length.


Journal Reference:

  1. Giovanni Traverso, Carl M. Schoellhammer, Avi Schroeder, Ruby Maa, Gregory Y. Lauwers, Baris E. Polat, Daniel G. Anderson, Daniel Blankschtein, Robert Langer. Microneedles for Drug Delivery via the Gastrointestinal Tract. Journal of Pharmaceutical Sciences, 2014; DOI: 10.1002/jps.24182

New absorber will lead to better biosensors

 


Biological sensors, or biosensors, are like technological canaries in the coalmine. By converting a biological response into an optical or electrical signal, they can alert us to dangers in our external and internal environments. They can sense toxic chemicals and particles in the air and enzymes, molecules, and antibodies in the body that could indicate diabetes, cancer, and other diseases.

An optical biosensor works by absorbing a specific bandwidth of light and shifting the spectrum when it senses minor changes in the environment. The narrower the band of absorbed light is, the more sensitive the biosensor.

"Currently, plasmonic absorbers used in biosensors have a resonant bandwidth of 50 nanometers," said Koray Aydin, assistant professor of electrical engineering and computer science in the McCormick School of Engineering. "It is significantly challenging to design absorbers with narrower bandwidths."

Aydin and his team have created a new nanostructure that absorbs a very narrow spectrum of light -- having a bandwidth of just 12 nanometers. This ultranarrow band absorber can be used for a variety of applications, including better biosensors.

"We believe that our unique narrowband absorber design will enhance the sensitivity of biosensors," Aydin said. "It's been a challenge to sense very small particles or very low concentrations of a substance."

This research was described in the paper "Ultranarrow band absorbers based on surface lattice resonances in nanostructured metal surfaces," published in the July 29 issue of ACS Nano.

Typical absorber designs use two metal sheets with a non-metallic insulating material in between. By using nanofabrication techniques in the lab, Aydin's team found that removing the insulating layer -- leaving only metallic nanostructures -- caused the structure to absorb a much narrower band of light. The absorption of light is also high, exceeding 90 percent at visible frequencies.

Aydin said this design can also be used in applications for photothermal therapy, thermo-photovoltaics, heat-assisted magnetic recording, thermal emission, and solar-steam generation.

"The beauty of our design is that we found a way to engineer the material by using a different substrate," Aydin said.


Story Source:

The above story is based on materials provided by Northwestern University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zhongyang Li, Serkan Butun, Koray Aydin. Ultranarrow Band Absorbers Based on Surface Lattice Resonances in Nanostructured Metal Surfaces. ACS Nano, 2014; 8 (8): 8242 DOI: 10.1021/nn502617t

 

Chapada Diamantina–Brasil - II

 

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As rochas da Chapada Diamantina fazem parte da unidade geológica conhecida como Supergrupo Espinhaço, que tomou este nome por ocorrer na serra do Espinhaço, no estado de Minas Gerais. Apresenta-se em geral como um altiplano extenso, com altitude média entre 800 e 1.200m acima do nível do mar. As serras que compõem a Chapada Diamantina abrangem uma área aproximada de 38.000 km² e são as divisoras de águas entre a bacia do rio São Francisco (rios S. Onofre, Paramirim) e os rios que deságuam diretamente no oceano Atlântico, como o Rio de Contas e o Rio Paraguaçu. As montanhas mais altas do Nordeste brasileiro estão na Chapada Diamantina: o Pico do Barbado com 2.033 metros, o Pico do Itobira com 1.970 metros e o Pico das Almas com 1.958 metros.

A Chapada Diamantina nem sempre foi uma imponente cadeia de serras. Há cerca de um bilhão e setecentos milhões de anos, iniciou-se a formação da bacia sedimentar do Espinhaço, a partir de uma série de extensas depressões que foram preenchidas com materiais expelidos de vulcões, areias sopradas pelo vento e cascalhos caídos de suas bordas. Sobre essas depressões depositaram-se sedimentos em uma região em forma de bacia, sob a influencia de rios, ventos e mares. Posteriormente, aconteceu um fenômeno chamado soerguimento, que elevou as camadas de sedimentos acima do nível do mar, pressionada pela força epirogenética, tendo aos pouco um sofrível erguimento ao longo de milhões de anos. As inúmeras camadas de arenitos, conglomerados, e calcários, hoje expostas na Chapada Diamantina, representam os depósitos sedimentares primitivos; a paisagem atual é o produto das atividades daqueles agentes ao longo do tempo geológico. Nas ruas e calçadas das cidades da Chapada, lajes de superfícies onduladas revelam a ação dos ventos e das águas que passavam sobre areais antigos.

Chapada Diamantina– Brasil

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A Chapada Diamantina é uma região de serras, protegida pelo Parque Nacional da Chapada Diamantina, situada no centro do estado brasileiro da Bahia, onde nascem quase todos os rios das bacias do Paraguaçu, do Jacuípe e do Rio de Contas. Essas correntes de águas brotam nos cumes e deslizam pelo relevo em belos regatos, despencam em borbulhantes cachoeiras e formam transparentes piscinas naturais. O parque nacional é administrado pelo Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio).1

A vegetação é exuberante, composta de espécies da caatinga semi-árida e da flora serrana, com destaque para as bromélias, orquídeas e sempre-vivas.

A Chapada Diamantina é composta por 28 municípios: Abaíra e seu distrito Ouro Verde e Catolés, Andaraí, Barra da Estiva, Dom Basílio, Ibitiara, Itaetê, Livramento de Nossa Senhora, Marcionílio Souza, Morro do Chapéu, Novo Horizonte, Palmeiras, Rio de Contas e seus distritos Arapiranga e Marcolino Moura, Ruy Barbosa, Seabra, Souto Soares, Tapiramutá, Utinga, Wagner, Boninal, Bonito, Ibicoara e seu distrito Cascavel, Ibiquera, Iraquara, Jussiape e seu distrito Caraguataí, Lençóis, Mucugê, Nova Redenção e Piatã e seus distritos Cabrália e Inúbia.

New frontier in error-correcting codes

 


Error-correcting codes are one of the glories of the information age: They're what guarantee the flawless transmission of digital information over the airwaves or through copper wire, even in the presence of the corrupting influences that engineers call "noise."

But classical error-correcting codes work best with large chunks of data: The bigger the chunk, the higher the rate at which it can be transmitted error-free. In the Internet age, however, distributed computing is becoming more and more common, with devices repeatedly exchanging small chunks of data over long periods of time.

So for the last 20 years, researchers have been investigating interactive-coding schemes, which address the problem of long sequences of short exchanges. Like classical error-correcting codes, interactive codes are evaluated according to three criteria: How much noise can they tolerate? What's the maximum transmission rate they afford? And how time-consuming are the encoding and decoding processes?

At the IEEE Symposium on Foundations of Computer Science this month, MIT graduate students past and present will describe the first interactive coding scheme to approach the optimum on all three measures.

"Previous to this work, it was known how to get two out of three of these things to be optimal," says Mohsen Ghaffari, a graduate student in electrical engineering and computer science and one of the paper's two co-authors. "This paper achieves all three of them."

Vicious noise

Moreover, where Claude Shannon's groundbreaking 1948 analysis of error-correcting codes considered the case of random noise, in which every bit of transmitted data has the same chance of being corrupted, Ghaffari and his collaborator -- Bernhard Haeupler, who did his graduate work at MIT and is now an assistant professor at Carnegie Mellon University -- consider the more stringent case of "adversarial noise," in which an antagonist is trying to interfere with transmission in the most disruptive way possible.

"We don't know what type of random noise will be the one that actually captures reality," Ghaffari explains. "If we knew the best one, we would just use that. But generally, we don't know. So you try to generate a coding that is as general as possible." A coding scheme that could thwart an active adversary would also thwart any type of random noise.

Error-correcting codes -- both classical and interactive -- work by adding some extra information to the message to be transmitted. They might, for instance, tack on some bits that describe arithmetic relationships between the message bits. Both the message bits and the extra bits are liable to corruption, so decoding a message -- extracting the true sequence of message bits from the sequence that arrives at the receiver -- is usually a process of iterating back and forth between the message bits and the extra bits, trying to iron out discrepancies.

In interactive communication, the maximum tolerable error rate is one-fourth: If the adversary can corrupt more than a quarter of the bits sent, perfectly reliable communication is impossible. Some prior interactive-coding schemes, Ghaffari explains, could handle that error rate without requiring too many extra bits. But the decoding process was prohibitively complex.

Making a list

To keep the complexity down, Ghaffari and Haeupler adopted a technique called list decoding. Rather than iterating back and forth between message bits and extra bits until the single most probable interpretation emerges, their algorithm iterates just long enough to create a list of likely candidates. At the end of their mutual computation, each of the interacting devices may have a list with hundreds of entries.

But each device, while it has only imperfect knowledge of the messages sent by the other, has perfect knowledge of the messages it sent. So if, at the computation's end, the devices simply exchange lists, each has enough additional information to zero in on the optimal decoding.

The maximum tolerable error rate for an interactive-coding scheme -- one-fourth -- is a theoretical result. The minimum length of an encoded message and the minimum decoding complexity, on the other hand, are surmises based on observation.

But Ghaffari and Haeupler's decoding algorithm is nearly linear, meaning that its execution time is roughly proportional to the length of the messages exchanged.

But linear relationships are still defined by constants: y = x is a linear relationship, but so is y = 1,000,000,000x. A linear algorithm that takes an extra second of computation for each additional bit of data it considers isn't as good as a linear algorithm that takes an extra microsecond.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Larry Hardesty. Note: Materials may be edited for content and length.


 

Adolescent exposure to THC may cause immune systems to go up in smoke

 


When it comes to using marijuana, new research, involving mice and published in the October 2014 issue of the Journal of Leukocyte Biology, suggests that just because you can do it, doesn't mean that you should. That's because a team of Italian scientists have found that using marijuana in adolescence may do serious long-term damage to the immune system. This damage may result in autoimmune diseases and chronic inflammatory diseases, such as multiple sclerosis, inflammatory bowel disease and rheumatoid arthritis in adulthood.

"I hope that the knowledge that early exposure to marijuana is associated with immediate and long-term deleterious effects on the immune system may reach adolescents and their families," said Paola Sacerdote, Ph.D., a researcher involved in the work from the Università degli Studi di Milano in Milano, Italy. "The increased risk of getting sick in adulthood may hopefully be a deterrent for marijuana abuse among young individuals."

To make this discovery, scientists injected "adolescent" mice with THC, the main active component of marijuana, for 10 days. This period in the mouse lifecycle corresponded to the adolescence period in humans (approximately ages 12-18). A second group of adolescent mice received only a placebo. At the end of treatments, both groups of animals were left undisturbed for approximately two months, until they reached full adulthood. The activity of the immune system was then evaluated, taking into consideration several important measurements, such as the ability of leukocytes to produce cytokines to mount an antibody response to vaccination or the capacity of macrophage to phagocyte particles. The group of mice treated with THC in adolescence had severe alterations of immune responses in adulthood, characterized by a clear switch toward a pro-inflammatory and cytotoxic phenotype.

"The immune system is characterized by an impressive ability to 'remember' previous exposures and changes during the period of immune system development especially early in life can have important long-term consequences," said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. "These studies not only point to adolescence as a key phase of immune system sensitivity, but also highly the dramatic and long-lasting negative effects that a common recreational drug abused by teenagers may have on immune function."


Story Source:

The above story is based on materials provided by Federation of American Societies for Experimental Biology. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Moretti, M. Castelli, S. Franchi, M. A. Raggi, L. Mercolini, M. Protti, L. Somaini, A. E. Panerai, P. Sacerdote. 9-Tetrahydrocannabinol-induced anti-inflammatory responses in adolescent mice switch to proinflammatory in adulthood. Journal of Leukocyte Biology, 2014; 96 (4): 523 DOI: 10.1189/jlb.3HI0713-406RR

 

New blood test determines whether you have or are likely to get cancer

 

September 30, 2014

Federation of American Societies for Experimental Biology

Early detection and the risk assessment of cancer as easy as a simple blood test, a new study suggests. "A blood test to detect cancer and determine one's risk for cancer is a game-changer," said one expert. "A test like this -- which is sophisticated in design and simple to perform -- could make effective cancer screening available in places where traditional medical technology might not be available."


A new research report published in the October 2014 issue of The FASEB Journal may make the early detection of cancer as easy as a simple blood test. This test, called the "lymphocyte genome sensitivity" (LGS) test, could not only detect some cancers earlier than ever before, but it may eliminate the need for some types of biopsies, as well as identify those more likely to develop cancer in the future.

"The test could allow earlier cancer detection, so helping to save peoples' lives," said Diana Anderson, a researcher involved in the work from the School of Life Sciences at the University of Bradford in West Yorkshire, United Kingdom.

To develop this test, Anderson and colleagues took blood samples from a group of people that included healthy individuals, cancer patients and people believed to be at a higher risk than normal to develop cancer. White blood cells (lymphocytes) in these samples were examined in a Comet test, by embedding the cells in a jelly-like substance, called agar, on a microscope slide. In this test, damage to the genetic material (DNA) of the cells was caused by treatment with ultraviolet (UVA) light. This damage was observed in the form of DNA pieces being pulled within the agar in an electric field toward the positive end of the field. This caused a comet-like tail, and the longer the tail the more DNA damage. Different thicknesses of the agar were applied to the slides. In healthy people, as different thicknesses were added, DNA-damaged tail responses returned to normal levels. In cancer patients, DNA-damaged tail responses remained high and in those people who might develop pre-cancerous diseases, tail responses were in between. This means that people with cancer have DNA which is more easily damaged by UVA than do other people, so the test shows the sensitivity to damage of all the genome in a cell. The LGS test has been used to examine blood samples from cancer patients with melanoma, colon cancer and lung cancer, and all gave the same outcomes.

"A blood test to detect cancer and determine one's risk for cancer is a game-changer," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "A test like this -- which is sophisticated in design and simple to perform -- could make effective cancer screening available in places where traditional medical technology might not be available."


Story Source:

The above story is based on materials provided by Federation of American Societies for Experimental Biology. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Anderson, M. Najafzadeh, R. Gopalan, N. Ghaderi, A. J. Scally, S. T. Britland, B. K. Jacobs, P. D. Reynolds, J. Davies, A. L. Wright, S. Al-Ghazal, D. Sharpe, M. C. Denyer. Sensitivity and specificity of the empirical lymphocyte genome sensitivity (LGS) assay: implications for improving cancer diagnostics. The FASEB Journal, 2014; 28 (10): 4563 DOI: 10.1096/fj.14-254748

 

Synthetic sperm protein raises the chance for successful in vitro fertilization

 


Having trouble getting pregnant -- even with IVF? Here's some hope: A new research report published in October 2014 issue of The FASEB Journal, explains how scientists developed a synthetic version of a sperm-originated protein known as PAWP, which induced embryo development in human and mouse eggs similar to the natural triggering of embryo development by the sperm cell during fertilization.

"We believe that the results of this study represent a major paradigm shift in our understanding of human fertilization by providing a precise answer to a fundamental unresolved scientific question in developmental biology," said Mahmoud Aarabi, M.D., Ph.D., a researcher involved in the work from the Department of Human Genetics at Montreal Children's Hospital Research Institute in Montreal, Canada. "Based on our findings, we envision that physicians will be able to improve their diagnosis and treatment of infertility, a problem that affects 10-15 percent of couples worldwide, and scientists will be able to finally resolve the signalling pathway leading to initiation of embryonic development in mammals."

To make their advance, Aarabi and colleagues injected transcripts coding for PAWP protein into human eggs, and the immediate fertilization events, including release of calcium inside the eggs, were investigated carefully. (The human eggs used in this study were donated by infertile women and consisted of immature eggs that were further matured in the laboratory and thus were not suitable for IVF.) The injected eggs were fixed before cell division. A similar protocol was used in mice where the PAWP protein was injected into the eggs. The scientists found that when PAWP inhibitors were injected with the sperm cell into the eggs, a procedure known as ICSI in human infertility therapy, they blocked the sperm-induced fertilization. This is the first time that any sperm protein is shown to be susceptible to such an important inhibition effect.

"Reducing the number of IVF cycles for couple would save them money and disappointment," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Equally important, this research helps us better understand the events that occur when an egg is first fertilized as well as what we can do to influence those events."


Story Source:

The above story is based on materials provided by Federation of American Societies for Experimental Biology. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Aarabi, H. Balakier, S. Bashar, S. I. Moskovtsev, P. Sutovsky, C. L. Librach, R. Oko. Sperm-derived WW domain-binding protein, PAWP, elicits calcium oscillations and oocyte activation in humans and mice. The FASEB Journal, 2014; 28 (10): 4434 DOI: 10.1096/fj.14-256495

 

Longitudinal report shows challenging reality of aging with an intellectual disability

 


A new report launched today by the Intellectual Disability Supplement to TILDA (The Irish Longitudinal Study on aging) conducted by academics from the School of Nursing and Midwifery, Trinity College Dublin, Ireland, has highlighted the serious, complex and unique health and social challenges facing Ireland's intellectual disability population.

The IDS-TILDA study is the first study of its kind in Europe and the only one in the world with the ability to compare the aging of people with intellectual disability directly with the general aging population.

For the first time in history, people in Ireland with an intellectual disability are growing old in considerable numbers. The IDS-TILDA Wave 2 Report, entitled Advancing Years, Different Challenges, looked at how the aging process is affecting the physical wellbeing and mental health of the more than 30,000 people in Ireland with an intellectual disability.

Among the key findings from the report which was launched today are a marked increase in the prevalence of dementia for people with Down syndrome, particularly in comparison to the general aging population; a range of stark findings relating to the levels of genuine connectedness to local communities among even those people with ID who had been moved to more community based residential settings as part of the Irish Government's health policy; and 50% lower rates of hypertension and three times lower rate of heart attack for people with ID compared to the general population despite having a higher risk profile than the general population.

Dean of the Faculty of Health Sciences in Trinity and Principal Investigator of IDS-TILDA, Professor Mary McCarron said: "This is the first time in history we have ever had a population of people with an intellectual disability who have reached old age and this is something that we should celebrate. However, there are a number of very serious health concerns that we need to better understand in this population. Unless we can address some of these challenges older people with ID are likely to live a poor quality of life as they grow older and aging in poor health is an empty prize."

Key Findings

Physical Health:

  • In the three year period since the first IDS-TILDA study was conducted (in 2010), the prevalence of dementia among people with Down syndrome has almost doubled from 15.8% to 29.9%. These are much higher levels than those seen in the general population. The average age of onset of dementia for people with Down syndrome was 55 years of age with some cases presenting in their early 40's. By comparison the majority of people with dementia in the general population are over 65 years of age.
  • Rates of hypertension were more than 50% lower for people with ID (17.5%) than for the general population (37%) while myocardial infarction (heart attack) was almost 3 times higher among the general population (as reported by TILDA) than for people with ID.
  • Reported rates of osteoporosis among people with ID had doubled by Wave 2 from 8.1% to 16.4%. However, measurements taken during the study's health assessments found that nearly 70% of people with ID indicated poor bone health implying a high level of under diagnosis of poor bone health among people aging with ID.
  • Over 70% of participants engaged in only low levels of physical activity, i.e., in levels of activity not likely to result in health benefits.
  • Rates of overweight and obesity were 67% however over 60% perceived themselves within a healthy normal weight range.
  • There was an almost 50% increase in the prevalence of cataracts since Wave 1 and macular degeneration rates almost doubled. These are higher reported rates compared to the general population.

Social participation and social connectedness:

  • Family networks of older people with ID in Ireland looked very different to that of the general population- older people with ID are generally single/unmarried and without any children or grandchildren. They are far more reliant on siblings and extended family to provide family networks, especially as they age and parents pass away. In addition, most family members of older people with ID lived in different neighbourhoods than their relative with ID.
  • Two thirds (66.3%) of respondents reported having trouble with reading, writing, numeracy and money management while 62.7% reported they were unable to read their own name. 32% of respondents had no education and the majority (85.7%) of adults with an ID were not currently engaged in further education.
  • Regardless of age over 70% of respondents participated in social activities with staff, with those with moderate to severe ID, regardless of whether they lived in the community or an institutional setting being heavily dependent on paid staff. Movement to a community group home did not appear to change the central social role that staff play in the lives of older adults with ID.
  • Internet use grew very slightly from 7.3% to 10.5%, however, this remains far below the usage rates among the general population of 77% (CSO, 2012). Just 12.6% said that they were able to turn on a computer. Ownership of mobile phones remained essentially the same (23.8%) and continues to compare poorly with mobile phone ownership figures nationally. Less than one in 20 could send a text message.
  • A significant proportion of people with ID, almost two-thirds (64.2%) either experience difficulty or else do not travel around their community at all.

Professor McCarron said: "The IDS-TILDA report provides the platform to raise the visibility, needs and experiences of people with ID as they grow older. It ensures there is evidence to underpin policy and evaluate how policy actually affects this population so that not only can we ensure that we have added years to life for people with ID as they grow old but also, and critically, that we have added life to years."

She continued: "In terms of social connectedness, our findings show that movement to the community does not necessarily equate with community integration. A change of geographical location in its own right isn't enough. The report confirms that despite often serving a higher functioning and younger population, community group home experiences in terms of community engagement resemble more traditional settings and a renewed effort is needed to ensure that community group homes are organised to support greater levels of genuine integration."

Professor McCarron concluded: "Our findings raise serious concerns for the planned movement from congregated settings of older adults with more severe and profound levels of ID and higher levels of ill health. We promised that movement to the community would improve the quality of people's lives. Unless the community is truly organised and resourced to support aging people with ID when there are complex health issues, their experience may instead be one of social isolation, loneliness and new forms of institutionalisation."

The full report is available here: https://www.dropbox.com/s/y4hkct5m8p85o1b/IDS-TILDA%20Report%20Wave%202%20September%202014%20-FINAL.pdf?dl=0

 


Story Source:

The above story is based on materials provided by Trinity College Dublin. Note: Materials may be edited for content and length.