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Science Snippets - Jan 9

Last Updated 08 January 2018, 15:14 IST

Increased use of nanoparticles harmful

Scientists from Council of Scientific and Industrial Research – Indian Institute of Toxicology Research and Amity University, Uttar Pradesh have been studying the harmful effects of Zinc Oxide nanoparticles (ZnO NPs) on living tissue and genes in mice, and their study reveals a potential threat lurking if increasing use of such nanoparticles is not addressed soon. Earlier studies have already established the potential of ZnO NPs to cause damage to DNA. In the study, scientists wanted to check for the genotoxic potential of ZnO NPs.

For their study, Swiss mice were administered ZnO NPs at dose levels 300 and 2000 mg/kg body weight, for duration of two days, 24 hours apart. After administration, the organism was checked for chromosomal aberration using the Organisation for Ecinomic Co-operation and Development (OECD) guidelines.

The results showed an increase in reactive oxygen species at the highest dose of 2,000 mg/kg body weight. The results showed conclusively that administration of ZnO NPs induced the production of reactive oxygen species, which in turn leads to chromosomal aberrations.

Variations in height

New research from Space Physics Laboratories, Thiruvananthapuram and Indian Institute of Science, Bengaluru has used a ground-based microwave radiometer profiler to evaluate the height of the atmospheric boundary layer. This was used to provide a better time resolution of the evolution of atmospheric boundary layer height (BLH) over the period of a day, over a tropical coastal region. The results showed that a monthly mean diurnal variation of the BLH showed a strong diurnal variation, with the highest occurring at around 12.00 to 3.00 pm and the lowest occurring during nighttime. It also showed that the daytime BLH was at a maximum in April, and the minimum occurring in July.

Mind Field: Isolation

In one sense, our global society is more connected now than ever before. In another, we've never been more isolated. Meanwhile, our thirst for non-stop stimulation strips away our desire for intimate knowledge of the self. But what effect do these factors have on the health, development and vitality of our brains?

Created and directed by Michael Stevens, the documentary Mind Field: Isolation seeks the answer to this question through a series of experiments. The documentary shows how regardless of how mundane our activities might be, we feel the need to fill our time with as many sources of stimulation as possible, and explores the possible impacts of isolation. To watch the documentary, visit www.bit.ly/2lZ1oUu.

Extending LiFi networks

Smart paint containing fluorescent and phosphorescent pigments could extend the possibilities of proposed LiFi networks, reports a research by  K S Narayan and team at the Jawaharlal Nehru Centre for Advanced Scientific Research in Bengaluru.

The researchers analysed the effect of nearby luminescent surfaces on the noise characteristics of visible light communication system (VLC) signals, and found that secondary emission could limit bandwidth locally by overwhelming receivers. The residual glow from phosphors could even be modulated to transmit a signal after the primary LED source has been turned off.

It has already been established  that VLCs can operate without line-of-sight contact between transmitters and receivers, since sufficiently high signal-to-noise ratios can be retained in light reflected from surfaces in the local environment. Now, Narayan and his team have investigated the situation for more complex arrangements, in which a luminescent component is superimposed on the primary signal.

The researchers measured the noise in the signal transmitted directly by the LED, and compared it with that contained in the signal mediated by fluorescent and phosphorescent surfaces. The research is published in the Journal of Optics.

Finding ET

NASA has developed an innovative new spectroscopy instrument to aid the search for extraterrestrial life. The new instrument is designed to detect compounds and minerals associated with biological activity more quickly and with greater sensitivity than previous instruments. Researchers at NASA Langley Research Centre and the University of Hawaii developed the new instrument, which improves on an analytical technique known as micro Raman spectroscopy. This technique uses the interaction between laser light and a sample to provide chemical composition information on a microscopic scale. In the journal  Applied Optics, the researchers report that their new system   is the first to perform micro-Raman analysis of samples 10 cm away from the instrument with 17.3-micron resolution.

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(Published 08 January 2018, 11:16 IST)

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