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Feb 23, 2017

Synopsis: Revealing a Hidden Spin Polarization

Posted by in category: materials

Photoemission spectroscopy has detected two different populations of spin-polarized electrons that are “hidden” within a layered, graphene-like material.

The layers inside certain materials can carry spin-polarized electrons, but this polarization is hidden to measurements that aren’t sufficiently localized. A new study using photoemission spectroscopy has detected the hidden spin polarization in a graphene-like material called molybdenum disulfide (MoS22). Unique to this work is the ability to target specific populations of spin-polarized electrons with circularly polarized light.

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Feb 22, 2017

Group develops deep, non-invasive imaging of mouse brain

Posted by in categories: engineering, neuroscience, physics

A three-photon microscopic video of neurons in a mouse brain. The imaging depth is approximately 1 millimeter below the surface of the brain. The firing of the neurons is captured by an indicator that is based on green fluorescent protein GFP, which glows brighter as the neuron sends a signal.

Nearly four years ago, then-President Obama launched the BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative, to “accelerate the development and application of new technologies that will enable researchers to produce dynamic pictures of the brain.”

Several of the program’s initial funding awards went to Cornell’s Chris Xu, the Mong Family Foundation Director of Cornell Neurotech – Engineering, and professor and director of undergraduate studies in applied and engineering physics. Xu’s projects aimed to develop new imaging techniques to achieve large scale, noninvasive imaging of neuronal activity.

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Feb 22, 2017

Why I Will No Longer Do Research Sponsored By The Department Of Homeland Security

Posted by in categories: education, ethics, government, security

“As academics we can sign petitions, but it is not enough.”

As academics we can sign petitions, but it is not enough. Scott Aaronson wrote very eloquently about this issue after the initial ban was announced (see also Terry Tao). My department has seen a dramatic decrease in the number of applicants in general and not just from Iran. We were just informed that we can no longer make Teaching Assistant offers for students who are unlikely to get a visa to come here.

The Department of Homeland Security has demonstrated its blatant disregard for moral norms. Why should we trust its scientific norms? What confidence do we have that funding will not be used in some coercive way? What does it say to our students when we ask them to work for DHS? Yes, the government is big, but at some point the argument that it’s mostly the guy at the top who is bad but the rest of the agency is still committed to good science becomes just too hard to swallow. I decided that I can’t square that circle. Each one of us should think hard about whether we want to.

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Feb 22, 2017

Switched-on DNA spark nano-electronic applications

Posted by in categories: bioengineering, biotech/medical, nanotechnology

DNA, the stuff of life, may very well also pack quite the jolt for engineers trying to advance the development of tiny, low-cost electronic devices.

Much like flipping your light switch at home — –only on a scale 1,000 times smaller than a human hair — –an ASU-led team has now developed the first controllable DNA switch to regulate the flow of electricity within a single, atomic-sized molecule. The new study, led by ASU Biodesign Institute researcher Nongjian Tao, was published in the advanced online journal Nature Communications ( DOI: 10.1038/ncomms14471).

“It has been established that charge transport is possible in DNA, but for a useful device, one wants to be able to turn the charge transport on and off. We achieved this goal by chemically modifying DNA,” said Tao, who directs the Biodesign Center for Bioelectronics and Biosensors and is a professor in the Fulton Schools of Engineering.

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Feb 22, 2017

Study Reveals Essential Role of Sympathetic Nerves in Muscle Health

Posted by in categories: biotech/medical, chemistry, health

Contrary to what has long been believed, the role of the sympathetic nervous system in muscle tissue goes far beyond controlling blood flow by contracting or relaxing blood vessels, according to studies conducted at the University of São Paulo (USP) in Brazil.

With support from FAPESP and the collaboration of researchers at Mannheim University and Heidelberg University in Germany, a group of Brazilian researchers led by Isis do Carmo Kettelhut and Luiz Carlos Carvalho Navegantes at the University of São Paulo’s Ribeirão Preto Medical School (FMRP USP) have demonstrated the importance of sympathetic innervation for the growth and maintenance of muscle mass and also for the control of movement.

Kettelhut is a full professor at FMRP -USP’s Biochemistry & Immunology Department. Navegantes is a professor in the same institution’s Physiology Department.

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Feb 22, 2017

Researchers uncover brain circuitry central to reward-seeking behavior

Posted by in category: neuroscience

Green: NAc-projecting prefrontal cortex neurons become active during the presentation of a reward-predictive cue, and this activity drives reward-seeking behavior. Purple: PVT-projecting prefrontal cortex neurons inhibited during reward-predictive cue. Credit: The Stuber Lab (UNC School of Medicine)

The prefrontal cortex, a large and recently evolved structure that wraps the front of the brain, has powerful “executive” control over behavior, particularly in humans. The details of how it exerts that control have been elusive, but UNC School of Medicine scientists, publishing today in Nature, have now uncovered some of those details, using sophisticated techniques for recording and controlling the activity of neurons in live mice.

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Feb 22, 2017

OCD-like behavior linked to genetic mutation, study finds

Posted by in categories: biotech/medical, genetics, neuroscience

Got OCD; check your genes for a mutation.


A new Northwestern Medicine study found evidence suggesting how neural dysfunction in a certain region of the brain can lead to obsessive and repetitive behaviors much like obsessive-compulsive disorder (OCD).

Both in humans and in mice, there is a circuit in the brain called the corticostriatal connection that regulates habitual and repetitive actions. The study found certain synaptic receptors are important for the development of this brain circuit. If these receptors are eliminated in mice, they exhibit obsessive behavior, such as over-grooming.

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Feb 22, 2017

From Fractured Genomes to Broken Minds

Posted by in category: biotech/medical

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In recent years, we have dramatically changed our view of human genome, from a collection of DNA base pairs that was largely quite stable to one whose very structure can change. We’ve learned that higher-order structural features, such as specific configurations of repeated base pair sequences, can predispose for DNA rearrangements.

One of the most intriguing types of DNA rearrangements is copy-number variants (CNVs), deletions or duplications of parts of the genome. While CNVs range in size from a few hundred base pairs to several mega-bases affecting the copy number of one to dozens of juxtaposed genes, they are not identifiable by conventional light microscopy. It was not until a few years ago that improved technology enabled us to perform high-resolution genome-wide surveys of CNVs in individual genomes. These surveys revealed a large amount of copy number variation (at least 12,000 CNVs overlapping more than 1,000 genes), most of which represent benign polymorphic changes. CNVs are classified as rare (occurring at a frequency of 1 percent in the population) or common; collectively they cover at least 12–13 percent of the genome in the general population.

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Feb 22, 2017

Scientists create a nano-trampoline to probe quantum behavior

Posted by in categories: nanotechnology, quantum physics

Very cool.


A research group from Bar-Ilan University, in collaboration with French colleagues at CNRS Grenoble, has developed a unique experiment to detect quantum events in ultra-thin films. This novel research, to be published in the scientific journal Nature Communications, enhances the understanding of basic phenomena that occur in nano-sized systems close to absolute zero temperature.

Transitions, Phases and Critical Points

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Feb 22, 2017

Solar photovoltaic windows rely on inexpensive silicon quantum dots

Posted by in categories: nanotechnology, quantum physics, solar power, sustainability

Luminescent solar concentrators (LSCs), which are flat panes of mostly transparent material that take sunlight (both diffuse and directed) and concentrate it at the panes’ edges, can be used as “photovoltaic windows,” which, as the name makes clear, collect solar energy while serving as ordinary windows. Now, researchers at the Università degli Studi di Milano-Bicocca and Glass to Power Srl (both of Milano, Italy) and the University of Minnesota (Minneapolis, MN) are lowering the potential cost of such windows by using silicon nanoparticles as the fluorescent absorber/emitter in the LSC windows.

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