Tag Archives: ultraviolet light

Testing Water for Antibiotic-Resistant Bacteria

Antibiotic-resistant bacteria are an important concern for disease prevention in the future. UA doctoral candidate Victoria Obergh is testing Tucson-area wastewater systems to find out where these bacteria can be found 

In the lab, Victoria Obergh transfers bacterial DNA samples into a tray. A graduate student in the University of Arizona’s Department of Soil, Water and Environmental Science, part of the College of Agriculture and Life Sciences, Obergh works with the samples under a sterile hood sporting an ultraviolet light to kill any unwanted DNA. (more…)

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What lit up the universe?

New research from UCL shows we will soon uncover the origin of the ultraviolet light that bathes the cosmos, helping scientists understand how galaxies were built.

The study published in The Astrophysical Journal Letters by UCL cosmologists Dr Andrew Pontzen and Dr Hiranya Peiris (both UCL Physics & Astronomy), together with collaborators at Princeton and Barcelona Universities, shows how forthcoming astronomical surveys will reveal what lit up the cosmos. (more…)

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The rhythm of everything

Dawn triggers basic biological changes in the waking human body. As the sun rises, so does heart rate, blood pressure and body temperature. The liver, the kidneys and many natural processes also begin shifting from idle into high gear. Then as daylight wanes and darkness descends, these processes likewise begin to subside, returning to their lowest levels again as we sleep.

These internal biological patterns are tightly linked to an external cosmic pattern: the earth’s rotation around the sun once every 24 hours. This endless loop of light and darkness and the corresponding synchrony of internal and external clocks, are called circadian rhythms, from “circa diem,” Latin for “approximately a day.” Circadian rhythms influence almost all living organisms, from bacteria to algae, insects, birds and, as is increasingly understood by science, humans beings. (more…)

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Study Explains Skin’s Response to UVA Light

Researchers have strengthened their understanding of how skin cells called melanocytes sense ultraviolet light and act to protect themselves with melanin. In a new study, they report experiments showing that an ion channel well-known elsewhere in the body for its chemical sensitivity, plays a central role in this process. (more…)

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Graphene Membranes May Lead To Enhanced Natural Gas Production, Less CO2 Pollution, Says CU Study

Engineering faculty and students at the University of Colorado Boulder have produced the first experimental results showing that atomically thin graphene membranes with tiny pores can effectively and efficiently separate gas molecules through size-selective sieving.

The findings are a significant step toward the realization of more energy-efficient membranes for natural gas production and for reducing carbon dioxide emissions from power plant exhaust pipes.

Mechanical engineering professors Scott Bunch and John Pellegrino co-authored a paper in Nature Nanotechnology with graduate students Steven Koenig and Luda Wang detailing the experiments. The paper was published Oct. 7 in the journal’s online edition. (more…)

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First Stars, Galaxies Formed more Rapidly than Expected

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (more…)

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Researchers ‘Print’ Polymers That Bend Into 3-D Shapes

*Technique could be used to direct growth of blood vessels or tissues in the laboratory*

Christian Santangelo, Ryan Hayward and colleagues at the University of Massachusetts Amherst recently employed photographic techniques and polymer science to develop a new technique for printing two-dimensional sheets of polymers that can fold into three-dimensional shapes when water is added. The technique may lead to wide ranging practical applications from medicine to robotics

The journal Science publishes the research in its March 9 issue. (more…)

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The Next Big Step Toward Atom-Specific Dynamical Chemistry

*Berkeley Lab scientists push chemistry to the edge, testing plans for a new generation of light sources*

For Ali Belkacem of Berkeley Lab’s Chemical Sciences Division, “What is chemistry?” is not a rhetorical question.

“Chemistry is inherently dynamical,” he answers. “That means, to make inroads in understanding – and ultimately control – we have to understand how atoms combine to form molecules; how electrons and nuclei couple; how molecules interact, react, and transform; how electrical charges flow; and how different forms of energy move within a molecule or across molecular boundaries.” The list ends with a final and most important question: “How do all these things behave in a correlated way, ‘dynamically’ in time and space, both at the electron and atomic levels?” (more…)

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