Skip navigation.
მთავარი

საძიებლები

მიმდინარეობს საიტის განახლება

ძიება ქართულ ბიბლიოთეკებში

Create your own Custom Search Engine
ძიება ქართულ ლექსიკონებში და ენციკლოპედიებში
Create your own Custom Search Engine
ძიება მსოფლიოს უნივერსიტეტების ღია სამეცნიერო არქივებში

Create your own Custom Search Engine

ღონისძიების ჩატარება ეროვნულ სამეცნიერო ბიბლიოთკაში

თქვენი ღონისძიების ჩასატარებლად ეროვნულ სამეცნიერო ბიბლიოთკაში, გთხოვთ, შეავსოთ სააპლიკაციო ფორმა და გადგმოგზავნოთ ელექტრონულ მისამართზე: infopr@sciencelib.ge

მსოფლიო სამეცნიერო სიახლეები

Gene editing just got easier

( Baylor College of Medicine ) An international team of researchers has made CRISPR technology more accessible and standardized by simplifying its complex implementation in a way that offers a broad platform for off-the shelf genome engineering.
კატეგორიები: ახალი ტექნოლოგიები

Ukrainian villages still suffering legacy of Chernobyl more than 30 years on

EurekAlert! - მედიცინა - პარ, 08/06/2018 - 08:00
( University of Exeter ) Milk in parts of Ukraine has radioactivity levels up to five times over the country's official safe limit, new research shows.
კატეგორიები: მედიცინა

La Nasa veut privatiser la station spatiale internationale

Yahoo! Actualités: Les titres Sciences - პარ, 08/06/2018 - 08:00
L'administration Trump souhaite transférer une partie des coûts de la station spatiale au privé. Un projet qui ne fait pas l'unanimité.

Vor G-7-Gipfel: Trump wettert gegen EU und Kanada

Wissen - FAZ.NET Frankfurter Algemeine - პარ, 08/06/2018 - 07:20
Vor ihrem Treffen machen die Protagonisten im Handelsstreit Front gegeneinander. Donald Trump trifft Japans Abe und schimpft auf europäische und kanadische Schutzzölle. Frankreichs Macron ist schon in Kanada und distanziert sich vom amerikanischen Präsidenten.

სიცოცხლის არსებობის ნიშნები მარსზე

astronet.ge - პარ, 08/06/2018 - 07:15
 მეცნიერთა საერთაშორისო ჯგუფმა(ა.შ.შ, საფრანგეთი, მექსიკა), 3 მილირდი წლის ასაკის მარსულ

Jens Spahn: Gesundheitsminister will HIV-Selbsttests zulassen

Wissen - FAZ.NET Frankfurter Algemeine - პარ, 08/06/2018 - 06:26
In Deutschland soll bald jeder selbst testen können, ob er den Aids-Erreger in sich trägt. Bundesgesundheitsminister Jens Spahn will HIV-Selbsttests frei verkäuflich machen. Das soll Hürden senken.

Türkei: Erdogan könnte nach Wahlen Ausnahmezustand aufheben

Wissen - FAZ.NET Frankfurter Algemeine - პარ, 08/06/2018 - 06:00
Bis zu den vorgezogenen Wahlen bleibt der 2016 verhängte Ausnahmezustand in Kraft – danach könne man darüber reden, so der türkische Präsident Erdogan. Seine Macht gefestigt hat er so oder so.

Bis zu 14 Millionen betroffen: Neue Datenpanne bei Facebook

Wissen - FAZ.NET Frankfurter Algemeine - პარ, 08/06/2018 - 05:39
Nachrichten, die nur für bestimmte Nutzer gedacht waren, wurden für alle Welt sichtbar gepostet. Der Fehler passierte vor wenigen Wochen, gestand Facebook ein. Wer betroffen ist, soll informiert werden.

Bertrand Cantat toujours au centre de la discorde

lemonde.fr - Culture - პარ, 08/06/2018 - 03:35
Le concert au Zénith de Paris du chanteur, qui s’en est pris sur scène aux journalistes, a été précédé d’une manifestation.

The 360 degree phone camera 'revolution'

BBC Technology - პარ, 08/06/2018 - 03:34
BBC Click's Dan Simmons looks at some of the best technology news stories of the week.
კატეგორიები: ახალი ტექნოლოგიები

Electric thrills

BBC Technology - პარ, 08/06/2018 - 03:29
Electric motorbikes are fast, clean, and quiet - could they eclipse electric cars?
კატეგორიები: ახალი ტექნოლოგიები

How electric motorbikes are zooming into the fast lane

BBC Technology - პარ, 08/06/2018 - 03:28
Legislation against vehicle pollution is giving electric motorbikes a boost around the world.
კატეგორიები: ახალი ტექნოლოგიები

Découverte prometteuse dans la quête de la vie sur Mars

Yahoo! Actualités: Les titres Sciences - პარ, 08/06/2018 - 03:26
ESPACE - Le robot Curiosity a détecté de la matière organique, ce qui signifie qu'il y a pu avoir de la vie par le passé...

‘Brain password’ uses Leo DiCaprio to unlock your phone

Futurity.org - პარ, 08/06/2018 - 03:19

Researchers are working on a “brain password” system that could let you unlock your phone with your brainwaves—or your reaction to a photo of Leonardo DiCaprio.

“Like a password, it’s easy to reset; and like a biometric, it’s easy to use.”

To overcome password fatigue, many smartphones include facial recognition, fingerprint scans, and other biometric systems. The trouble with these easy-to-use tools, however, is that once compromised—and yes, they can be hacked—you can’t reset them.

“You can’t grow a new fingerprint or iris if that information is divulged,” says Wenyao Xu, assistant professor of computer science and engineering in the School of Engineering and Applied Sciences at the University at Buffalo.

“That’s why we’re developing a new type of password—one that measures your brainwaves in response to a series of pictures. Like a password, it’s easy to reset; and like a biometric, it’s easy to use.”

The “brain password,” which would require users to wear a headset, could have implications in banking, law enforcement, airport security, and other areas.

Unlocking your phone with your brain

“To the best of our knowledge, this is the first in-depth research study on a truly cancelable brain biometric system. We refer to this as ‘hard cancellation,’ meaning the original brain password can be reset without divulging the user’s identity,” says collaborator Zhanpeng Jin, associate professor of computer science and engineering at UB.

They describe the work in a study that will be presented June 11 at MobiSys 2018, a mobile computing conference that the Association for Computing Machinery will host in Germany.

Xu was motivated to create a cancelable biometric password after hackers stole the fingerprint files of 5.6 million workers from the US Office of Personal Management in 2015.

Perhaps the most accessible way to record brain activity is through electroencephalography, which uses electrodes to measure the brain’s unique patterns of electrical activity.

For their system, Xu and collaborators reconfigured a virtual reality headset, reducing the number of electrodes to six. Three record brain activity, two serve as grounds, and the last acts as a reference point. Typically, these headsets have 32 to 64 electrodes.

The electrodes recording brain activity measure three areas of the organ: the intraparietal sulcus (controls declarative memory), the inferior parietal lobule (processes face recognition), and the temporo parietal junction (reading comprehension).

Researchers chose specific image types to stimulate each brain region. They used animal pictures for the intraparietal sulcus because one’s memory of a certain animal can be highly individualized. For example, a person who suffered a spider bite will have a different reaction than someone who hasn’t.

For the inferior parietal lobule, researchers relied on recognizable celebrities such as Leonardo DiCaprio. For the temporo parietal junction, they used encouraging phrases such as “aspire to inspire.”

How does it work?

Users are shown the three images in rapid succession—1.2 seconds to be exact. The process is repeated three additional times. By the end of the fourth time, after 4.8 seconds, the brain password is ready.

Researchers recruited 179 adults—93 men, 86 women—to test the brain password. Test subjects’ average age was 30. They collected data from three sessions, including one that occurred five months after the original test. The goal of the last test was to see how brain passwords functioned over time.

Overall, brain passwords were more than 95 percent effective. The performance dipped slightly, by 1 percent, on the last test.

‘Smart fabric’ could store passcodes or I.D. in clothes

While wearing a headset may not appeal to common internet users, Xu says that may change over time, especially if the device becomes something more like Google Glass.

Plus, he says, companies with deep concerns about cybersecurity may be early adopters of the technology. As for privacy concerns, Xu says the system—even if hacked—would not divulge sensitive information.

“These passwords contain information gathered from only three channels in less than five seconds. Semantic memory attacks need much more time than that,” says Xu, who plans to continue work on the system to make it more reliable and appealing to users.

The National Science Foundation and its Center for Identification Technology Research supported the research.

Source: University at Buffalo

The post ‘Brain password’ uses Leo DiCaprio to unlock your phone appeared first on Futurity.

Guppy guys grow bigger brains when predators are near

Futurity.org - პარ, 08/06/2018 - 03:04

Male guppies exposed to predators in the wild or in captivity have heavier brains than those living in relatively predator-free conditions, according to new research.

Behavioral ecologists sampled guppies from two rivers in northern Trinidad. In each river, guppies live both above a waterfall, a location that only guppies and a few other small species of fish have managed to colonize, and below the fall, where many predators including pike cichlids live.

“The brain is a highly malleable organ and experiences early in life can shape how it develops.”

“Guppies offer an excellent model for evolutionary research because they have colonized multiple independent rivers in Trinidad where they are exposed to a variety of different conditions,” says lead author Adam Reddon, now at Liverpool John Moores University in the UK, who worked on the project as a postdoctoral fellow in the lab of biology professor Simon Reader at McGill University.

“We were particularly interested in finding out how the brains of these widely-distributed fish have evolved for dealing with the challenges of living under predation threat.”

guppies Wild-type guppies in an aquarium with two females to the left and three males (note their smaller body size and orange-color patches) to the right. (Credit: Laura Chouinard-Thuly/McGill)

The researchers looked at whether there are differences in relative brain mass between wild guppies they collected from high and low predation populations and found that, for their body size, males collected from high predation sites had on average 17 percent heavier brains compared to males from low predation sites in the same river. Female guppies, by contrast, did not show this pattern.

To test the origins of these findings, the ecologists conducted a laboratory experiment in which they exposed young guppies to cues of predation risk

“The brain is a highly malleable organ and experiences early in life can shape how it develops. We wanted to see if the predation effect we detected in male guppies in the wild could be due to experiences in their early life stages,” says coauthor Laura Chouinard-Thuly, a PhD candidate in biology at McGill.

Researchers exposed the fish to the sight of a predator living in an adjacent aquarium for five minutes at a time, five times a week, during the first 45 days of their life. The researchers also added the scents of predators and an alarm cue guppies release. Guppies in the control group were exposed to the sight and smells of a non-predatory fish.

Again, the researchers found that males exposed to predator cues during development had 21 percent heavier brains than the control group. They found no evidence that the exposure to predation cues influenced the relative brain mass of female guppies. Males are more brightly colored and attractive to predators. The results suggest that a larger brain for their body size is advantageous under predation threat, perhaps allowing the fish to detect, learn about, or react to predators better.

Tool gives scientists a glimpse of real-time brain activity

Brains can use a lot of energy and are generally only as large as they need to be for animal survival and reproduction. Female guppies are 2-10 times the size of males and tend to live longer. They play a slow and steady strategy to reproduce and so may consistently benefit from paying the high costs of building and maintaining larger brain tissue, whereas male guppies may only benefit under high predation risk.

“Female guppies have larger brains for their body size than do males; our results suggest that males only grow larger brains when they will benefit,” Reader says. “Obviously, the next steps are to determine which parts of the brain are expanding, and how this impacts behavior”.

The research appears in the journal Functional Ecology. Funding came from the Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation.

Source: McGill University

The post Guppy guys grow bigger brains when predators are near appeared first on Futurity.

Just how gross are airplane cabins really?

Futurity.org - პარ, 08/06/2018 - 02:59

The bacterial communities accompanying airline passengers at 30,000 feet have a lot in common with the bacterial communities surrounding people in their homes and offices, according to a new study.

“Airline passengers should not be frightened by sensational stories about germs on a plane…”

Using advanced sequencing technology, researchers studied the bacteria found on three components of an airliner cabin that are commonly touched by passengers: tray tables, seat belt buckles, and the handles of lavatory doors. They swabbed those items before and after ten transcontinental flights and also sampled air in the rear of the cabin during flight.

What they found was surprisingly unexciting.

“Airline passengers should not be frightened by sensational stories about germs on a plane,” says Vicki Stover Hertzberg, a professor in Emory University’s Nell Hodgson Woodruff School of Nursing and a coauthor of the study in Microbial Ecology. “They should recognize that microbes are everywhere and that an airplane is no better and no worse than an office building, a subway car, home, or a classroom. These environments all have microbiomes that look like places occupied by people.”

Given the unusual nature of an aircraft cabin, the researchers hadn’t known what to expect from their microbiome study. On transcontinental flights, passengers spend four or five hours in close proximity breathing a very dry mix of outdoor air and recycled cabin air that passes through special filters, similar to those found in operating rooms.

“There were reasons to believe that the communities of bacteria in an aircraft cabin might be different from those in other parts of the built environment, so it surprised me that what we found was very similar to what other researchers have found in homes and offices,” says Howard Weiss, a professor in Georgia Institute of Technology’s School of Mathematics and the study’s corresponding author. “What we found was bacterial communities that were mostly derived from human skin, the human mouth—and some environmental bacteria.”

The sampling found significant variations from flight to flight, which is consistent with the differences other researchers have found among the cars of passenger trains, Weiss notes. Each aircraft seemed to have its own microbiome, but the researchers did not detect statistically significant differences between preflight and post-flight conditions on the flights they studied.

“I carry a bottle of hand sanitizer in my computer bag whenever I travel…”

“We identified a core airplane microbiome—the genera that were present in every sample we studied,” Weiss adds. The core microbiome included genera Propionibacterium, Burkholderia, Staphylococcus, and Strepococcus (oralis).

Though the study revealed bacteria common to other parts of the built environment, Weiss still suggests travelers exercise reasonable caution.

“I carry a bottle of hand sanitizer in my computer bag whenever I travel,” says Weiss. “It’s a good practice to wash or sanitize your hands, avoid touching your face, and get a flu shot every year.”

This new information on the aircraft microbiome provides a baseline for further study, and could lead to improved techniques for maintaining healthy aircraft.

“The finding that airplanes have their own unique microbiome should not be totally surprising since we have been exploring the unique microbiome of everything from humans to spacecraft to salt ponds in Australia. The study does have important implications for industrial cleaning and sterilization standards for airplanes,” says Christopher Dupont, another coauthor and an associate professor in the microbial and environmental genomics department at the J. Craig Venter Institute, which provided bioinformatics analysis of the study’s data.

The 229 samples researchers obtained from the aircraft cabin testing were subjected to 16S rRNA sequencing, which was done at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama. The small amount of genetic material captured on the swabs and air sampling limited the level of detail the testing could provide to identifying genera of bacteria, Weiss says.

In March, in the journal Proceedings of the National Academy of Sciences, the researchers reported on the results of another component of the FlyHealthy study that looked at potential transmission of respiratory viruses on aircraft. They found that an infectious passenger with influenza or other droplet-transmitted respiratory infection will most likely not transmit infection to passengers seated farther away than two seats laterally and one row in front or back on an aircraft.

Here’s whose germs can infect you on a plane

That portion of the study was designed to assess rates and routes of possible infectious disease transmission during flights, using a model that combines estimated infectivity and patterns of contact among aircraft passengers and crew members to determine likelihood of infection. FlyHealthy team members monitored specific areas of the passenger cabin, developing information about contacts between passengers as they moved around.

Among next steps, the researchers would like to study the microbiome of airport areas, especially the departure lounges where passengers congregate before boarding. They would also like to study long-haul international flights in which passengers spend more time together—and are more likely to move about the cabin.

Additional coatuhors are from the HudsonAlpha Institute for Biotechnology and the Boeing Company. A contract between the Georgia Institute of Technology and the Boeing Company supported the work.

Source: Georgia Tech

The post Just how gross are airplane cabins really? appeared first on Futurity.

Brain ‘ripples’ lock in mental maps while bodies rest

Futurity.org - პარ, 08/06/2018 - 02:36

New research using machine learning techniques shows that it’s possible to harvest minimal data from animal brains during periods of rest to shed light on how the brain forms and retains memories.

The researchers’ work employs hidden Markov models commonly used in machine learning to study sequential patterns. Their strategy analyzes waves of firing neurons that race in an instant across the hippocampus and beyond in animals while they’re active and, significantly, while they rest.

Mental maps

The firing patterns of neurons in the hippocampus—seahorse-shaped tissues in each hemisphere of the brain—have long been seen as important to the formation and storage of memories. Researchers detect and measure these patterns by placing electrodes into the brains to monitor them in real time.

mouse memoryUsing hidden Markov models that analyze sequences of data to predict next steps, researchers showed how to identify structures related to memory from neuronal firing patterns gathered while animals rested. The technique could help neuroscientists understand how the brain builds and commits spatial and temporal maps to memory. (Credit: Etienne Ackermann/Rice)

“Animals encode a memory of an environment as they run around,” says Caleb Kemere, an assistant professor of electrical and computer engineering at Rice University who specializes in neuroscience. “They form a spatial map as individual neurons are activated in different places. When they’re awake in our experiments, they’re probably doing that exploration process 40 to 60 percent of the time.

“But for the other 40 percent, they’re scratching themselves, or they’re eating, or they’re sort of snoozing,” he says. “They’re not asleep, but they’re paused; I like to call it introspecting.”

Those periods of introspection provided the critical data for the study that inverted the usual process of matching brain activity to movement while the animals were active. The researchers gathered the primary data over the course of many experiments under the direction of Kamran Diba, an associate professor and leader of the Neural Circuits and Memory Lab at Michigan Medicine.

As the animals explored either back-and-forth tracks or maze-like environments, electrodes in their brains sensed sharp wave-associated bursts of neural activity called population burst events (PBEs). In these events, between 50,000 and 100,000 neurons all fire within 100 milliseconds and send ripples throughout the brain that are not yet fully understood.

Experiments elsewhere had shown that PBEs included the activation of place cells in the hippocampus when an animal is in a particular location. These cells fire in a sequence that helps program the brain’s spatial and episodic memory, allowing the animal to build an internal map of its environment.

But the new experiments ignored all neural activity during active behavior or exploration and relied on data gathered only when the animals were paused—in total, about 2 percent of the time during experiments. The research team’s models were able to sort “recall” or “reactivation” bursts that appear to represent memories from other noisy signals in the hippocampus.

The researchers believe these signals in active animals presage the encoding of cells that make up place fields and show that in resting minds, PBEs offer a way to uncover a memory or spatial map without directly observing those cells in the locations that they would normally fire.

“We realized there’s enough data in those periods of reactivation that we can construct models from what the animals remember,” Kemere says. These turned out to correspond remarkably well with patterns represented by Bayesian analysis of theta waves generated while the animals were active, he says.

“When I was recording the data, I was mostly interested in neuronal activity during theta oscillations, when the animal was running,” Diba says. “However, the resting information turned out to be the most interesting aspect.”

Reconstructed memories

Markov models provided a template on which the pieces of a memory could be assembled. “Markovian dynamics simply state that you can predict your next step by only knowing your current step,” says Rice graduate student Etienne Ackermann, co-lead author of the paper. “You don’t need to know your entire past before that.

“In the brain, we think about these steps as underlying states that we cannot see directly,” he says. “They’re really hidden. But we can observe some proxy to those underlying states when we record electrical activity. It doesn’t tell us the internal state of the brain, but it can give us enough information to use a hidden Markov model to make a best guess about the sequence of the states.”

With enough sequences, the researchers were able to statistically recognize those that represent the memory of an environment, even when the experiments were unsupervised—that is, with no data that directly correlated brain activity with physical activity.

“I was surprised at how well it worked, and how much rich information about the environment was captured by the hidden Markov models,” says Diba, whose lab helped strategize ways to identify events.

“This is a really neat example of how we can use advanced machine learning techniques on brain data,” Kemere says. “It gives us the ability to see the structure of memory when those memories are being covertly expressed.

Evidence shows animals can play back memories

“With the hippocampus, you can normally see the structure of a memory by correlating it with animal behavior,” he says. “By using unsupervised learning, we were able to form that same structure from the periods when there was no behavior. This reveals an incredible richness in these covert memories.”

Kemere says the new models can be used to analyze existing sleep data sets. “We’ve known for a while that when animals sleep, reactivation and consolidation processes go on,” he says. “We can gather data but we really haven’t known what to do with it.”

He expects the models will help researchers sort forming memories from signals that represent dreams, noise, or even the essential process of forgetting useless data.

“Because we haven’t had a good way to quantitatively assess whether something is a good memory or a noisy memory, there are a lot of hypotheses about how sleep and reactivation should work that we haven’t been able to test,” Kemere says. “This is going to allow us to understand memory in places where we never have before.”

Protein calls up ‘reserves’ to make stronger memories

Researchers from the University of Michigan; the University of Wisconsin-Milwaukee; the University of Texas Southwestern at Dallas; and the University of California, Berkeley, contributed to this research.

The National Science Foundation, the National Institute of Mental Health, and the Human Frontiers Science Program supported the research. The team’s paper appears in the journal eLife.

Source: Rice University

The post Brain ‘ripples’ lock in mental maps while bodies rest appeared first on Futurity.

ინფოარხების ცნობების შეკრება