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Familiar drugs may block Ebola virus infection

A well-known class of molecules, many of which are already in use therapeutically, may be able to block the Ebola virus’s entry into cells and halt the disease in its tracks, according to researchers at the University of Illinois at Chicago.


The study is available online in advance of print in the Journal of Virology.

 

 

Ebola and the closely related Marburg virus are among the most lethal in the world, both highly contagious and deadly. There is an urgent need to develop either a vaccine or effective antiviral therapy to prevent future outbreaks.

 

 

“We know very little about the basic biology of these diseases,” said Lijun Rong, UIC professor in microbiology and immunology and principal investigator on the new study.

 

 

Rong and his colleagues found that Ebola and Marburg viruses both use gateways called G protein-coupled receptors, or GPCRs, to enter a cell after attaching to its surface. Blocking entry with a drug that ties up the receptor may prove to be an effective therapy.

 

 

“These G protein-coupled receptors are a big family of closely related molecules in humans — altogether, probably more than a thousand,” said Rong. Because GPCRs are involved in many human diseases, he said, a host of drugs have already been developed that target them.

 

 

“In the history of therapeutics, about half of our drugs were developed to target GPCRs. For example, a number of antihistamines used as allergy medications are GPCR receptor antagonists,” he said.

 

 

Rong and his coworkers screened  approximately a thousand compounds using a NIH-funded high-throughput screening facility. They found 20 GPCR antagonists, or molecules that block GPCR receptors, were able to block Ebola and Marburg viruses from entering cells.

 

Learning how the two viruses infect cells and how they can be blocked offers the hope of finding therapeutics to combat both deadly diseases, Rong said.

 

“There are a lot of drugs and compounds that work through this mechanism — acting as antagonists to GPCR receptors,” he said. “This gives us a huge repertoire that can be tested against Ebola/Marburg.”

 

 

 

 

Source: University of Illinois at Chicago

 

 

Published on   13th August 2015

The Shame of Psychology

Thomas Scheff would like psychologists to talk about emotion — not simply to share feelings, but to advance science. According to the emeritus professor of sociology at UC Santa Barbara, intuition could be the catalyst that enables psychology to progress in areas in which it has stagnated.


His research, “Three Scandals in Psychology: The Need for a New Approach,” is published in the Review of General Psychology.

 

Scheff argues that research into aggression catharsis, stigma and self-esteem have become bogged down because scientific method in psychology is blind to the insights that intuition — that which doesn’t require “rational” thought — can provide.

 

Scheff points to the example of Danish astronomer Tycho Brahe, who spent his life trying to determine the orbit of Venus. Although his observations were meticulous, the science was sabotaged by the common belief that the planets revolved around the Earth. After Brahe’s death, Johannes Kepler, working with Brahe’s data, solved the problem through an accident of intuition.

 

“Scientific and other methods, no matter how scrupulously applied, are helpless in the face of misleading tropes,” Scheff writes in the paper. He defines tropes as false assumptions — ideas taken for granted that may be untrue or only partially true.

 

Aggression catharsis, or the venting of anger, is a trope embraced by the public, he continues. Psychologists have shown that venting doesn’t work, but they’ve erred in thinking that there is no such thing as catharsis, according to Scheff. He argues that catharsis is real and achieved through “pendulation,” the process by which people alternate between reliving an experience and watching themselves relive it.

 

“You’re going back and forth between the emotional moment and the safe present,” he said. “Some writers call it the safe zone. You’ve found the safe zone where you can relive fear that’s actually pleasant. That’s why young people like to ride rollercoasters; because they feel safe. The rollercoaster is a safe machine and therefore they can feel fear in a safe zone.”

 

Scheff recalled that venting was an accepted therapy for many years, despite its

evident failure. Working as a marriage counselor decades ago, he was encouraged to use venting in his practice. “My teachers told me that the way to deal with angry people was to have them beat on a pillow with a tennis racquet and yell at the pillow,” he said. “It never worked. I never had one client who was helped by that.”

 

Stigma, which has been studied extensively, is another area that most psychologists get wrong, according to Scheff. The problem, he explained, is that stigma usually is defined as a mark of disgrace as a result of some humiliation. However, he argued, stigma is a certain kind of shame that is actually an emotion — something science poorly understands.  “Scholars are just as confused by emotions as the public,” he said. “They’re studying an emotion, but they don’t know it, because it’s hidden in modern societies.”

 

Shame is particularly misunderstood, Scheff claimed, because of its social toxicity. “Why the reluctance to use shame? In an individualistic society, shame is shameful,” he said. “It’s shame about shame. You know what happens in a theater fire, where people get afraid because others are frightened? They get into a loop and they do horrible things. That’s a fear cycle, a fear loop. Modern societies, because they’re so individualistic, they’re in shame loops.”

 

Scheff has a harsh assessment of the study of self-esteem. He noted that over the past 50 years more than 20,000 studies have used some 200 self-esteem scales. Their failure, he said, is clear; the scales’ ability to predict behavior is less than 5 percent.

 

“Despite the failure and the critics, researchers have continued to research with self-esteem scales, as if they want to repeat the Brahe error forever,” he said, adding that the problem is one of researchers confusing thoughts with emotions. Future studies, he noted, could split the scale into cognitive and emotional components.

 

As someone who has studied emotions for 40 years, Scheff noted that psychology and the public will progress only after the meaning and ramifications of emotions are addressed. “We need to be able to talk about them to ourselves and others,” he said. “Feel and reveal is the secret.”

 

 

 

 

Source: University of California – Santa Barbara.

 

Published on 26th  June 2015

Distinguishing coincidence from causality: connections in the climate system

Detecting how changes in one spot on Earth – in temperature, rain, wind – are linked to changes in another, far away area is key to assessing climate risks. Scientists now developed a new technique of finding out if one change can cause another change or not, and which regions are important gateways for such teleconnections. They use advanced mathematical tools for an unprecedented analysis of data from thousands of air pressure measurements. The method now published in Nature Communications can be applied to assess geoengineering impacts as well as global effects of local extreme weather events, and can potentially also be applied to the diffusion of disturbances in financial markets, or the human brain.


 

“Despite the chaos of weather you see a lot of correlations – for instance higher pressure in the East Pacific is often followed by lower pressure in the Indian Monsoon region,” says lead-author Jakob Runge of the Potsdam Institute for Climate Impact Research (PIK). “However, if you take a closer look, you find that many correlations are simply due to another process driving both regions, an important example being the solar cycle. So you use elaborate statistics to reveal such spurious links, find new indirect pathways, and step by step you reconstruct a network more closely representing cause and effect.” The new tool detects where major perturbations entering the climate system have the largest global effect, and via which pathways they are conveyed.

 

East Pacific, Indonesia, tropical Atlantic most important

 

The East Pacific, Indonesia and the tropical Atlantic are the regions most important for spreading and transmitting perturbations, the scientists found. One reason is that in these regions particularly huge air masses rise high up in the atmosphere. So for instance warming in the East Pacific can disturb the Indian Monsoon, even though it is thousands of kilometers away. This can put at risk yields on which millions of small farmers and in fact large parts of the population depend.

 

“How to robustly distinguish coincidence from causality in complex nonlinear systems has long been a riddle,” says Jürgen Kurths, co-author and head of PIK’s Research Domain Transdisciplinary Concepts and Methods. “Conventional approaches, based on pairwise association measures, in some cases showed good results. Yet these methods are rather limited. You can compare it to multiple organ failure in the human body – a real puzzle for the doctors. We’re glad that we can now present a new approach to understanding the connections, which is the basis for ideally making the whole system more resilient.”

 

 

 

Source: Potsdam Institute for Climate Impact Research (PIK)

 

Published on  8th  October  2015

Plasmonic’ material could bring ultrafast all-optical communications

Researchers have created a new “plasmonic oxide material” that could make possible devices for optical communications that are at least 10 times faster than conventional technologies.


In optical communications, laser pulses are used to transmit information along fiber-optic cables for telephone service, the Internet and cable television.

 

Researchers at Purdue University have shown how an optical material made of aluminum-doped zinc oxide (AZO) is able to modulate – or change – how much light is reflected by 40 percent while requiring less power than other “all-optical” semiconductor devices.

 

“Low power is important because if you want to operate very fast – and we show the potential for up to a terahertz or more – then you need low energy dissipation,” said doctoral student Nathaniel Kinsey. “Otherwise, your material would heat up and melt when you start pushing it really fast. All-optical means that unlike conventional technologies we don’t use any electrical signals to control the system. Both the data stream and the control signals are optical pulses.”

 

Being able to modulate the amount of light reflected is necessary for potential industrial applications such as data transmission.

 

“We can engineer the film to provide either a decrease or an increase in reflection, whatever is needed for the particular application,” said Kinsey, working with a team of researchers led by Alexandra Boltasseva, an associate professor of electrical and computer engineering, and Vladimir M. Shalaev, scientific director of nanophotonics at Purdue’s Birck Nanotechnology Center and a distinguished professor of electrical and computer engineering. “You can use either an increase or a decrease in the reflection to encode data. It just depends on what you are trying to do. This change in the reflection also results in a change in the transmission.”

 

Findings were detailed in a research paper appearing in July in the journal Optica, published by the Optical Society of America.

 

The material has been shown to work in the near-infrared range of the spectrum, which is used in optical communications, and it is compatible with the complementary metal–oxide–semiconductor (CMOS) manufacturing process used to construct integrated circuits. Such a technology could bring devices that process high-speed optical communications.

 

The researchers have proposed creating an “all optical plasmonic modulator using CMOS-compatible materials,” or an optical transistor.

 

In electronics, silicon-based transistors are critical building blocks that switch power and amplify signals. An optical transistor could perform a similar role for light instead of electricity, bringing far faster systems than now possible.

 

The Optica paper, featured on the cover of the journal, was authored by Kinsey, graduate students Clayton DeVault and Jongbum Kim; visiting scholar Marcello Ferrera from Heriot-Watt University in Edinburgh, Scotland; Shalaev and Boltasseva.

 

Exposing the material to a pulsing laser light causes electrons to move from one energy level called the valence band to a higher energy level called the conduction band. As the electrons move to the conduction band they leave behind “holes” in the valance band, and eventually the electrons recombine with these holes.

 

The switching speed of transistors is limited by how fast it takes conventional semiconductors such as silicon to complete this cycle of light to be absorbed, excite electrons, produce holes and then recombine.

 

“So what we would like to do is drastically speed this up,” Kinsey said.

 

This cycle takes about 350 femtoseconds to complete in the new AZO films, which is roughly 5,000 times faster than crystalline silicon and so fleeting that light travels only about 100 microns, or roughly the thickness of a sheet of paper, in that time.

 

“We were surprised that it was this fast,” Kinsey said.

 

The increase in speed could translate into devices at least 10 times faster than conventional silicon-based electronics.

 

The AZO films are said to be “Epsilon-near-zero,” meaning the refractive index is near zero, a quality found normally in metals and new “metamaterials,” which contain features, patterns or elements that enable unprecedented control of light by harnessing clouds of electrons called surface plasmons. Unlike natural materials, metamaterials are able to reduce the index of refraction to less than one or less than zero. Refraction occurs as electromagnetic waves, including light, bend when passing from one material into another. Each material has its own refraction index, which describes how much light will bend in that particular material and defines how much the speed of light slows down while passing through a material.

 

The pulsing laser light changes the AZO’s index of refraction, which, in turn, modulates the amount of reflection and could make higher performance possible.

 

“If you are operating in the range where your refractive index is low then you can have an enhanced effect, so enhanced reflection change and enhanced transmission change,” he said.

 

The researchers “doped” zinc oxide with aluminum, meaning the zinc oxide is impregnated with aluminum atoms to alter the material’s optical properties. Doping the zinc oxide causes it to behave like a metal at certain wavelengths and like a dielectric at other wavelengths.

 

A new low-temperature fabrication process is critical to the material’s properties and for its CMOS compatibility.

 

“For industrial applications you can’t go to really high fabrication temperatures because that damages underlying material on the chip or device,” Kinsey said. “An interesting thing about these materials is that by changing factors like the processing temperature you can drastically change the properties of the films. They can be metallic or they can be very much dielectric.”

 

The AZO also makes it possible to “tune” the optical properties of metamaterials, an advance that could hasten their commercialization, Boltasseva said.

 

The ongoing research is based at Purdue’s Birck Nanotechnology Center and is funded by the Air Force Office of Scientific Research, a Marie Curie Outgoing International Fellowship, the National Science Foundation, and the Office of Naval Research.

 

 

Source: Purdue University

 

Published on  31st July  2015

Study Sheds Light on Source of Drug Addicts Risk-Taking Behavior

A study out today provides new insight into how the brains of drug addicts may be wired differently.  The findings, which appear in the journal Psychopharmacology, show that while drug users have very strong motivation to seek out “rewards,” they exhibit an impaired ability to adjust their behavior and are less fulfilled once they have achieved what they desire.  Addressing this disconnect between the craving for a drug and the ability to regulate behavior may be one of the keys to breaking the cycle of addiction.

Legacy of slavery still impacts education in the South

Slavery was abolished more than 150 years ago, but its effects are still felt today in K-12 education in the South, according to a new Rice University study, “How the Legacy of Slavery and Racial Composition Shape Public School Enrollment in the American South.”


 

“Our results suggest that the legacy of slavery contributes to black-white education disparities through greater public-private school racial segregation,” said Heather O’Connell, co-author and postdoctoral fellow at Rice’s Kinder Institute for Urban Research.

 

Using regression analysis to explain differences in the degree of attendance disparities across most counties in the South, researchers found a correlation between historical geographic slave concentration and modern day K-12 school segregation. An increase in slave concentration is related to greater underrepresentation of white students in public schools.

 

Overall, the proportion of black students in a county who are enrolled in public schools is an average of 17 percent higher than white students. But that gap in public school attendance is even larger where slaves were more heavily concentrated, increasing by just over 1 percentage point with every 10 percentage-point increase in slave concentration.

 

Soon after slavery was abolished, the former slaves quickly organized schools, according to the study. However, white resistance was substantial. Several other separation tactics were employed along the way, but the construction of private schools was the most recent action taken to maintain a segregated school system.

 

“As blacks began to enter the local white public schools, private schools cropped up seemingly overnight,” the researchers said.

 

Private schools are important for explaining contemporary school segregation. The study found that having more private schools in a county is related to a greater underrepresentation of white students in public schools. But this relationship doesn’t explain why slavery still matters for public-private school segregation.

 

The researchers found the same is true when considering another important county characteristic — the relative size of the black population. Generally speaking, a larger concentration of black students is related to increased separation of white students. The findings of this study support this “white flight” argument, but add another dimension.

 

“Whites are increasingly not enrolled in public schools in counties with higher black concentrations and are instead increasingly enrolled in private schools,” the researchers said. But O’Connell said that the role of black population concentration plays out primarily in states where slavery was most strongly rooted.

 

The study found that the black population concentration relationship only holds in the original Confederate States, or Deep South: Alabama, Florida, Georgia, Louisiana, Mississippi, South Carolina and Texas.

 

Even with this added dimension, the researchers were unable to identify tangible county characteristics that explain why slave concentration from 1860 is related to contemporary school enrollment patterns. The relationship is complex, but the authors urge greater attention to how slavery relates to contemporary racial disparities.

 

“Understanding the role of our slavery history provides insight into the structural foundations supporting this segregation, which might be valuable to efforts to reverse dangerous trends in school resegregation that have been increasing across the South over the last few decades,” O’Connell said.

 

 

 

 

Source: Rice University

 

Published on 26th  June 2015

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