What global climate change may mean for leaf litter in streams and rivers

Science Daily - Fri, 03/03/2017 - 1:13pm
Carbon emissions to the atmosphere from streams and rivers are expected to increase as warmer water temperatures stimulate faster rates of organic matter breakdown. But a new study suggests these decay rates may not increase as much as expected. In fact, the study indicates average breakdown rates may increase 5 percent to 21 percent with a 1 degree to 4-degree Celsius rise in water temperature — half as much as the 10 percent to 45 percent increase predicted by metabolic theory.
Categories: Science

A hot cup of attention tempered with chocolate, please

Science Daily - Fri, 03/03/2017 - 1:12pm
Deep down, we always knew it, but science is proving that cocoa and caffeine are indeed the best marriage ever. Researchers examined the acute effects of brewed cocoa consumption on attention, motivation to perform cognitive work and feelings of anxiety, energy and fatigue.
Categories: Science

Social rejection by those closest to you can lead to subsequent drinking

Science Daily - Fri, 03/03/2017 - 1:12pm
The need to belong and experience social connections is a fundamental human characteristic. Prior research has shown that social rejection is linked to increases in negative emotions, distress, and hostility. This study examined the impact of social rejection on alcohol use, and whether the impact differed when the social rejection was by close others, such as friends, spouses or family members, or by strangers or acquaintances.
Categories: Science

Mike Pence Used His AOL Email For Indiana State Business -- and It Got Hacked

Slashdot - Fri, 03/03/2017 - 1:00pm
An anonymous reader quotes a report from The Verge: Vice President Mike Pence used a personal AOL email account to conduct sensitive state business -- including issues related to homeland security -- as the governor of Indiana, according to a report from The Indianapolis Star. Not only that, but Pence's email account was also compromised last year, the report reveals. Because personal email accounts are not subject to same types of public transparency laws, it's up to the official and his or her transition staff to hand over any sensitive state-related messages for archiving. Emails from a state account are automatically stored on state servers and subject to public records requests. Pence's office claims the contents of his personal AOL account used for state business are in fact in the process of being archived. A larger concern, however, is security. By using a private AOL account to conduct sensitive state matters, Pence could have exposed sensitive state business. In the hacking incident last year, Pence's email account was compromised by a scammer who used it to try and extort money from members of his contact list by claiming Pence and his wife were stranded in the Philippines, The Indianapolis Star reports. This hack didn't appear to have had been designed specifically to breach Pence's office, which made clear that his AOL account could be compromised by relatively benign breaching techniques designed by spammers and low-level hackers. It is not illegal in Indiana to own and use a personal account while in office, nor is it against the law to handle work-related matters from a personal account -- so long as those emails are in some way archived. However, the Star reports that Pence made no efforts to preserve his AOL emails under after he left office and is only just now doing months after public records requests were first made. "Similar to previous governors, during his time as governor of Indiana, Mike Pence maintained a state email account and a personal email account," reads a statement given to the The Indianapolis Star. "As governor, Mr. Pence fully complied with Indiana law regarding email use and retention. Government emails involving his state and personal accounts are being archived by the state consistent with Indiana law, and are being managed according to Indiana's Access to Public Records Act."

Read more of this story at Slashdot.

Categories: Science

NASA Spacecraft Avoids Collision with Martian Moon Phobos

Space.com - Fri, 03/03/2017 - 12:38pm
Close call! NASA's Mars-orbiting spacecraft shifted course this week to avoid a future collision with Mars' dark moon Phobos.
Categories: Science

Logan Review: This Is How Wolverine Was Supposed to End

Wired News - Fri, 03/03/2017 - 12:30pm
Hugh Jackman's final turn in the claws is his best yet. The post Logan Review: This Is How Wolverine Was Supposed to End appeared first on WIRED.
Categories: Science

New Jupiter Images: Do You See Cotton Candy or Van Gogh's 'Starry Night'?

Space.com - Fri, 03/03/2017 - 12:30pm
Images of Jupiter captured by NASA's Juno probe look like great works of art when processed by citizen scientists. New additions show the cloud tops of Jupiter in cotton-candy colors, and swirls that resemble the sky in Vincent Van Gogh's "Starry Night."
Categories: Science

California’s Looking for New Tax Revenue? Weed ’em and Reap

Wired News - Fri, 03/03/2017 - 12:00pm
The stoners have spoken: California is set to become the country's largest legal marijuana market . But the path to legit pot isn't straight and narrow. The post California's Looking for New Tax Revenue? Weed 'em and Reap appeared first on WIRED.
Categories: Science

Lasers and Galoshes: How the Feds Divine if Rivers Need Help

Wired News - Fri, 03/03/2017 - 12:00pm
Federal protection for water is way bigger—and way more technical—than the Clean Water Rule. The post Lasers and Galoshes: How the Feds Divine if Rivers Need Help appeared first on WIRED.
Categories: Science

Could SpaceX Really Launch People Around the Moon Next Year?

Space.com - Fri, 03/03/2017 - 12:00pm
A lot will have to go right for SpaceX to meet its ambitious goal of launching two people on a mission around the moon before the end of 2018, experts say.
Categories: Science

Astronaut's-Eye View: Stunning Spacewalk Video Captures Vistas from Space

Space.com - Fri, 03/03/2017 - 12:00pm
A new video shows a space station spacewalk from the astrounaut's perspective.
Categories: Science

Where Are All the Baby Stars? High-Flying Balloon Telescope Could Find Out

Space.com - Fri, 03/03/2017 - 12:00pm
After 11 days of riding Antarctic air currents, BLAST descended and hit a snag.
Categories: Science

Groundbreaking technology rewarms large-scale animal tissues preserved at low temperatures

Kurzweil AI - Fri, 03/03/2017 - 4:16am

Inductive radio-frequency heating of magnetic nanoparticles embedded in tissue (red material in container) preserved at very low temperatures restored the tissue without damage (credit: Navid Manuchehrabadi et al./Science Translational Medicine)

A research team led by the University of Minnesota has discovered a way to rewarm large-scale animal heart valves and blood vessels preserved at very low (cryogenic) temperatures without damaging the tissue. The discovery could one day lead to saving millions of human lives by creating cryogenic tissue and organ banks of organs and tissues for transplantation.

The research was published March 1 in an open-access paper in Science Translational Medicine.

Long-term preservation methods like vitrification cool biological samples to an ice-free glassy state, using very low temperatures between -160 and -196 degrees Celsius, but tissues larger than 1 milliliter (0.03 fluid ounce) often suffer major damage during the rewarming process, making them unusable for tissues.

In the new research, the researchers were able to restore 50 milliliters (1.7 fluid ounces) of tissue with warming at more than 130°C/minute without damage.

Radiofrequency inductive heating of iron nanoparticles

To achieve that, they developed a revolutionary new method using silica-coated iron-oxide nanoparticles dispersed throughout a cryoprotectant solution around the tissue. The nanoparticles act as tiny heaters around the tissue when they are activated using noninvasive radiofrequency inductive energy, rapidly and uniformly warming the tissue.

This transmission electron microscopy (TEM) image shows the iron oxide nanoparticles (coated in mesoporous silica) that are used in the tissue warming process. (credit: Haynes research group/University of Minnesota)

The results showed that none of the tissues displayed signs of harm — unlike control samples using vitrification and rewarmed slowly over ice or using convection warming. The researchers were also able to successfully wash away the iron oxide nanoparticles from the sample following the warming.

“This is the first time that anyone has been able to scale up to a larger biological system and demonstrate successful, fast, and uniform warming of hundreds of degrees Celsius per minute of preserved tissue without damaging the tissue,” said University of Minnesota mechanical engineering and biomedical engineering professor John Bischof, the senior author of the study.

Organs next

Bischof said there is a strong possibility they could scale up to even larger systems, like organs. The researchers plan to start with rodent organs (such as rat and rabbit) and then scale up to pig organs and then, hopefully, human organs. The technology might also be applied beyond cryogenics, including delivering lethal pulses of heat to cancer cells.

The researchers’ goal is to eliminate transplant waiting lists. Currently, hearts and lungs donated for transplantation must be discarded because these tissues cannot be kept on ice for longer than a matter of hours, according to the researchers.*

It will be interesting to see if the technology can one day be extended to cryonics.

The research was funded by the National Science Foundation (NSF), National Institutes of Health (NIH), U.S. Army Medical Research and Materiel Command, Minnesota Futures Grant from the University of Minnesota, and the University of Minnesota Carl and Janet Kuhrmeyer Chair in Mechanical Engineering. Researchers at Carnegie Mellon University, Clemson University and Tissue Testing Technologies LLC were also involved in the study.

* “A major limitation of transplantation is the ischemic injury that tissue and organs sustain during the time between recovery from the donor and implantation in the recipient. The maximum tolerable organ preservation for transplantation by hypothermic storage is typically 4 hours for heart and lungs; 8 to 12 hours for liver, intestine, and pancreas; and up to 36 hours for kidney transplants. In many cases, such limits actually prevent viable tissue or organs from reaching recipients. For instance, more than 60% of donor hearts and lungs are not used or transplanted partly because their maximum hypothermic preservation times have been exceeded. Further, if only half of these discarded organs were transplanted, then it has been estimated that wait lists for these organs could be extinguished within 2 to 3 years.” — Navid Manuchehrabadi et al./Science Translational Medicine

Abstract of Improved tissue cryopreservation using inductive heating of magnetic nanoparticles

Vitrification, a kinetic process of liquid solidification into glass, poses many potential benefits for tissue cryopreservation including indefinite storage, banking, and facilitation of tissue matching for transplantation. To date, however, successful rewarming of tissues vitrified in VS55, a cryoprotectant solution, can only be achieved by convective warming of small volumes on the order of 1 ml. Successful rewarming requires both uniform and fast rates to reduce thermal mechanical stress and cracks, and to prevent rewarming phase crystallization. We present a scalable nanowarming technology for 1- to 80-ml samples using radiofrequency-excited mesoporous silica–coated iron oxide nanoparticles in VS55. Advanced imaging including sweep imaging with Fourier transform and microcomputed tomography was used to verify loading and unloading of VS55 and nanoparticles and successful vitrification of porcine arteries. Nanowarming was then used to demonstrate uniform and rapid rewarming at >130°C/min in both physical (1 to 80 ml) and biological systems including human dermal fibroblast cells, porcine arteries and porcine aortic heart valve leaflet tissues (1 to 50 ml). Nanowarming yielded viability that matched control and/or exceeded gold standard convective warming in 1- to 50-ml systems, and improved viability compared to slow-warmed (crystallized) samples. Last, biomechanical testing displayed no significant biomechanical property changes in blood vessel length or elastic modulus after nanowarming compared to untreated fresh control porcine arteries. In aggregate, these results demonstrate new physical and biological evidence that nanowarming can improve the outcome of vitrified cryogenic storage of tissues in larger sample volumes.

Categories: Science

Tiny fibers open new windows into the brain

Kurzweil AI - Thu, 02/03/2017 - 7:53am

A multifunctional flexible fiber that enables viral delivery, optical stimulation, and recording with one-step surgery. (credit: Seongjun Park et al./Nature Neuroscience)

Imagine a single flexible polymer fiber 200 micrometers across — about the width of a human hair — that can deliver a combination of optical, electrical, and chemical signals between different brain regions, with the softness and flexibility of brain tissue — allowing neuroscientists to leave implants in place and have them retain their functions over much longer periods than is currently possible with typical stiff, metallic fibers.

That’s what a team of MIT scientists has reported in the journal Nature Neuroscience. (Previous research efforts in neuroscience have generally relied on separate devices: needles to inject viral vectors for optogenetics, optical fibers for light delivery, and arrays of electrodes for recording, adding complication and the need for tricky alignments among the different devices.)

Multifunctional

For example, in tests with lab mice, the researchers were able to inject viral vectors that carried genes called opsins (which sensitize neurons to light) through one of two fluid channels in the fiber. They waited for the opsins to take effect, then sent a pulse of light through the optical waveguide in the center, and recorded the resulting neuronal activity, using six electrodes to pinpoint specific reactions. All of this was done through a single flexible fiber.

“It can deliver the virus [containing the opsins] straight to the cell, and then stimulate the response and record the activity — and [the fiber] is sufficiently small and biocompatible so it can be kept in for a long time,” says Polina Anikeeva, a professor in the MIT Department of Materials Science and Engineering.

Since each fiber is so small, “potentially, we could use many of them to observe different regions of activity,” she says. In their initial tests, the researchers placed probes in two different brain regions at once, varying which regions they used from one experiment to the next, and measuring how long it took for responses to travel between them.

The key ingredient that made this multifunctional fiber possible was the development of conductive “wires” that maintained the needed flexibility while also carrying electrical signals well. The team engineered a composite of conductive polyethylene doped with graphite flakes. The polyethylene was initially formed into layers, sprinkled with graphite flakes, then compressed; then another pair of layers was added and compressed, and then another, and so on.

The team aims to reduce the width of the fibers further, to make their properties even closer to those of the neural tissue and use material that is even softer to match the adjacent tissue.

The research team included members of MIT’s Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, McGovern Institute for Brain Research, Department of Chemical Engineering, and Department of Mechanical Engineering, as well as researchers at Tohuku University in Japan and Virginia Polytechnic Institute. It was supported by the National Institute of Neurological Disorders and Stroke, the National Science Foundation, the MIT Center for Materials Science and Engineering, the Center for Sensorimotor Neural Engineering, and the McGovern Institute for Brain Research.

Abstract of One-step optogenetics with multifunctional flexible polymer fibers

Optogenetic interrogation of neural pathways relies on delivery of light-sensitive opsins into tissue and subsequent optical illumination and electrical recording from the regions of interest. Despite the recent development of multifunctional neural probes, integration of these modalities in a single biocompatible platform remains a challenge. We developed a device composed of an optical waveguide, six electrodes and two microfluidic channels produced via fiber drawing. Our probes facilitated injections of viral vectors carrying opsin genes while providing collocated neural recording and optical stimulation. The miniature (<200 μm) footprint and modest weight (<0.5 g) of these probes allowed for multiple implantations into the mouse brain, which enabled opto-electrophysiological investigation of projections from the basolateral amygdala to the medial prefrontal cortex and ventral hippocampus during behavioral experiments. Fabricated solely from polymers and polymer composites, these flexible probes minimized tissue response to achieve chronic multimodal interrogation of brain circuits with high fidelity.

Categories: Science

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