Citation: Scientists say plants can remember properties of light (2010, July 16) retrieved 18 August 2019 from https://phys.org/news/2010-07-scientists-properties.html More information: via BBC This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further The images showed chemical reactions in leaves that were not exposed to light (PhysOrg.com) — Researchers in Poland say plants are able to remember and react to information on light intensity and quality by transmitting information from leaf to leaf. © 2010 PhysOrg.com Internal clock, external light regulate plant growth The scientists, led by Professor Stanislaw Karpinski of the Warsaw University of Life Sciences, used fluorescence imaging to view the response of specimens of the Arabidopsisa plant to light shone on them. They found that when light was shone on one leaf at the bottom of the plant the entire plant responded. The response, in the form of a cascade of chemical reactions induced by the light, continued even after the light source was removed, suggesting the plant was remembering the information contained in the light.Karpinski and colleagues discovered that when light is shone on a leaf a chemical reaction begins in one leaf cell and the reaction is immediately signaled to the rest of the plant by photo-electro-physiological signals (PEPS) from specialized cells called bundle sheath cells. Karpinski said the cells function in a similar way to a nervous system in animals.Professor Karpinski said animals have a “network of neurons, synapses, electro-physiological circuits and memory, but plants have their network of chloroplasts (connected by stromules), photo-electro-physiological signals transduced by bundle sheath cells, and cellular light memory.”Another discovery made by the team was that the plants responded differently to red, white and blue light. Karpinski thought the different responses might produce chemical reactions that protected the plant against disease. To test this idea the team shone light on the plant for an hour and then infected it with either bacteria or viruses.The results showed that if plants were infected before having the light shone on them there was no resistance to the disease, but if the light was shone on them for an hour and then they were infected 24 hours later, the plants did resist the infection. Karpinski said this demonstrated exposure to the light built up the plant’s immunity to pathogens, and that they were able to adjust to varying light conditions. Karpinski said that the quality of light varies from season to season and it appears the plants might use the information in the light to determine the season and immunize themselves against diseases prevalent at that time of year.The findings were presented at the annual meeting of the Society for Experimental Biology in Prague, Czech Republic.
Citation: Decoding early Martian weather: Analyzing carbonate minerals in meteorite Allan Hills 84001 (2011, October 24) retrieved 18 August 2019 from https://phys.org/news/2011-10-decoding-early-martian-weather-carbonate.html More information: Carbonates in the Martian meteorite Allan Hills 84001 formed at 18 ± 4 °C in a near-surface aqueous environment, Published online before print October 3, 2011, PNAS October 11, 2011 vol. 108 no. 41 16895-16899, doi:10.1073/pnas.1109444108 Explore further Led by Itay Halevy (currently at the Weizmann Institute of Science in Israel), along with Woodward W. Fischer and John M. Eiler, the research team faced a number of challenges. “The main challenge,” Halevy says, “was making an isotope clumping measurement on a precious, low-carbonate-abundance material.” Isotope clumping in carbonates denotes the tendency of heavy carbon and oxygen isotopes in carbonates (and in CO2) to bond with each other rather than with the elements’ lighter isotopes. This temperature-dependent tendency is the basis of multiply substituted (clumped) isotope thermometry. Clumped isotope thermometry is based on the tendency of heavy carbon and oxygen isotopes to bond with each other rather than with the lighter isotopes of these elements in a way that is effectively independent of the material’s isotopic composition: However abundant or rare the heavy isotopes are in a sample, they will still prefer to form bonds with each other, and this preference will always depend on temperature – and the colder it is, the higher the preference. “Other isotopic thermometers are based on the temperature dependence of the difference in chemical or isotopic composition between the aqueous solution and the carbonates that precipitate from it,” notes Halevy, “so to derive temperature one must know the chemical or isotopic composition of both the carbonates and the parent fluid. Unfortunately, it is impossible to know the composition of ancient fluids and so one must make some assumptions about their composition. Any temperature determined in this way is always dependent on these assumptions.” Clumped isotope thermometry avoids this because no matter how abundant the heavy isotopes are, they will always tend to bond in a temperature-dependent way.“The clumping measurement, developed by John Eiler and his students and postdocs at Caltech over the last seven to eight years, is itself challenging to make,” Halevy continues. The natural abundance of C-O clumps is only a few tens parts-per-million, which means you have to measure a lot of material to get a precise and accurate result – and we didn’t have a lot of material. ALH84001 is a 4-billion-year-old, originally 2 kg Martian rock; we had 5.5 grams, using 3 grams in the analysis – and of these 3 grams, only about 1% was carbonate minerals.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. While that was an appreciable amount of carbonate for a single clumping measurement, the researchers wanted to cut the gas into three measurements to get an internal stratigraphy (the study of strata, or layers) of the carbonate concretions. “To this,” Halevy comments, “add the increased risk of sample contamination associated with long acid digestion times – up to 12 hours for the more recalcitrant magnesium-rich carbonates – and you have the makings of an analytical challenge.”To overcome the low abundance of carbonate, the team performed a microvolume measurement. “Basically,” Halevy explains, “we froze the sample of CO2 gas released from the carbonates by acid digestion into a very small volume, shut it off from a lot of dead volume in the plumbing of the mass spectrometer, and thawed it in the small volume alone. The high pressure achieved by compressing the gas into a small volume allowed us to make the measurement under conditions that are close to the way the clumping measurement is typically made. Still, there are some important differences from a typical clumping measurement, so it took a lot of experimentation to map how the microvolume affected the results and to figure out ways to minimize these effects – or at least account for them.” As for the increased risk of contamination, the team performed extra purification steps to remove miscellaneous contaminants and again experimented extensively to convince themselves that the measurement was in no way compromised by the long reaction times.There are other innovations that could be applied to the protocol, mainly having to do with instrument improvements. “As mass spectrometers become more sensitive and are able to better differentiate between molecules of slightly differing mass,” Halevy explains, “low sample abundance and contamination will cease to be issues. A clumping measurement would be easier to make on small amounts of sample and any contaminations would be easily distinguishable from the CO2 molecules of interest. This would increase confidence in the measured temperature. “Halevy also points out that they developed the aquifer hypothesis on the basis of isotopic variability within the carbonate concretions and in light of the new insight that the temperature hovered around 20 °C. “Basically, given the temperature, the isotopic variability can only be explained by the drying-out of an aqueous reservoir that did not exchange CO2 freely with the atmosphere. The only environment we could come up with that meets these requirements is a subsurface aquifer. Increased confidence in the measured temperature would translate into increased confidence in this model for the formation environment of the carbonates.”Regarding computer modeling, Halevy says that while computer models are important for developing a quantitative understanding of analytical results, such as those presented in the paper, they can’t replace the measurements. “The measurements provide the physical constraints,” Halevy states, “and we can then use computer simulation to try and tease out information about process and environment.” In the team’s study, for example, measurements yielded the temperature and isotopic composition of the aqueous solution, while computer simulations allowed a quantitative estimate of how much of the water had to have evaporated, depending on the conditions of evaporation.In terms of applying their findings to exoplanetary exploration, Halevy stresses that “The mass spectrometers on or rovers, as well as the means for sample preparation and purification, would have to improve dramatically for a carbonate clumping measurement to be made in situ. Nevertheless, this may not be beyond the realm of possibility and may teach us much about aqueous processes on other planets. In addition, the ability to make a carbonate clumping measurement automatically implies the ability to measure clumping in CO2 and, therefore, the ability to explore certain atmospheric processes. Finally, clumping in molecules other than CO2 – such as organic molecules – may hold information not only about temperature, but the processes that formed them as well.”Halevy’s research will continue to include an analytical/experimental component and a modeling/simulation component. “Providing quantitative constraints on chemical processes on modern and ancient Mars will continue to feature prominently in my research,” Halevy concludes. “These same approaches will also be applied to understanding the geochemistry of Earth’s early oceans and atmospheric evolution.” (PhysOrg.com) — While geological evidence points to the presence of liquid water on Mars during the Noachian epoch (the period from 4.5 to 3.5 billion years ago), determining the temperature of that water – a factor critical to the probability of its ability to support early life – has hitherto been impossible. Recently, however, researchers at California Institute of Technology Geological and Planetary Sciences have derived a precipitation temperature of 18 °C from carbonate minerals found in the 4.1 billion-year-old Allan Hills 84001 (ALH84001) meteorite. Although this ancient aquifer’s temperature was relatively mild, the researchers note that their findings do not necessarily demonstrate habitability. Copyright 2011 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Model for carbonate formation in ALH84001. (A) Physical model of a shallow subsurface aquifer. The depth of carbonate formation is constrained by a combination of the cosmic ray exposure pattern of ALH84001 and Martian meteorite ejection models (48, 49). (B) Reduction of the physical model to a geochemical model of carbonate precipitation and CO2 degassing driven by gradual evaporation of water in a confined volume, coupled to loss of the vapor phase. Copyright (c) PNAS, doi:10.1073/pnas.1109444108 Wet and mild: Researchers take the temperature of Mars’s past
(PhysOrg.com) — Edmodo, the leading education centric social networking site has announced that it is opening its Application Programming Interface (API) to third party developers in a bid to entice more teachers to use the site. Edmodo is a Facebook-like site that is restricted to teachers, parents, students and school districts and is used primarily as an online tool between teachers and their students. It currently has a user base of approximately six million. By opening up their API, Edmodo is hoping to increase that number and to profit from its take on the applications that are created and sold for the platform. Citation: Education social networking site Edmodo to open API to third party developers (2012, March 7) retrieved 18 August 2019 from https://phys.org/news/2012-03-social-networking-site-edmodo-api.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: Press release Teachers admit to bullying students Explore further Edmodo was founded in 2008 by Nicolas Borg and Jeff O’Hara and is based in San Mateo California. It’s currently available in English, Spanish, Portuguese, German, Greek and French and as a result is used by educators and students across the globe. To use the site, teachers create an account for themselves that includes a profile and a means for adding all of the students in a class. After that, teachers and their students can communicate back and forth, quizzes can be given, grades posted (privately) and questions can be asked and answered. The whole point is to facilitate a process outside of the normal learning environment of the classroom to allow both teachers and their students a secondary avenue for reaching goals in the educational process.By opening up their API, Edmodo will allow third party developers to create apps for the site that can be used in ways very similar to those users see on Facebook, except of course, the apps on Edmodo will all be aimed specifically at helping teachers teach, and students learn. To make sure that happens, Edmodo has created a sister site called the Teacher-Developer Exchange that provides a mechanism for teachers and developers to communicate with one another directly.To get the ball rolling, Edmodo has also announced that 35 initial apps are already available for download from its own apps store, some of which are free, while some are not. Edmodo gets a fifteen percent cut on each app sold. Apps are expected to range from learning games for the students, to addendums to textbooks, to processes that help teachers create and manage their lesson plans. What’s not clear yet is whether school districts will get in on the act and pay for the apps that teachers want to use or if Edmodo will offer discounts for school districts that do so. © 2011 PhysOrg.com
© 2012 Phys.Org (Phys.org) — Researchers from Microsoft and the University of Washington have together created a system whereby a computer user can use hand gestures to instigate a limited set of computer commands such as scrolling and mimicking mouse double-clicking, that uses nothing but inaudible sound and doesn’t require any hardware other than a standard computer microphone and speakers. PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen The system is based on the now famous Doppler Effect, whereby the frequency of sound waves changes as an object making noises passes by another that hears it. In the real world, most recognize it as the way sirens appear to change the way they sound when an emergency vehicle passes by. With this new system, the engineers record the change in frequency of a tone (20 and 22 kilohertz, beyond normal hearing range) generated by the computer’s speaker using the computer’s microphone, when an object, such as a hand passes by. Software, the team calls SoundWave analyzes the frequencies and converts them to computer commands. It can also be used with a Smartphone. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: SoundWave: Using the Doppler Effect to Sense Gestures (research paper)Project page: research.microsoft.com/en-us/u … roups/cue/soundwave/ Microsoft Kinect makes moves on computers Explore further Play Video credit: Dan Morris and Desney Tan Thus far, the team has managed to capture five basic variables involved with the change in frequency: velocity, direction, proximity, the size of the object and time variation. By capturing and measuring these variables when hand gestures are made in front of a computer, SoundWave is able to perform scrolling, recognize tap and double tap (mimic mouse clicks) perform a two handed seesaw (to turn objects on screen) and recognize sustained motion. The result is a system that is good enough to allow a computer user to play a game of Tetris without ever touching the computer. It also can be made to recognize when a person approaches a computer, causing it to wake up, or to go back to sleep as soon as the person leaves.The team has tested the software on a multitude of different kinds and brands of computers using existing hardware and has found that no tweaking was necessary to perform basic functions and overall commands were executed correctly ninety percent of the time. They also tested the system using a variety of users and in several environments, including a noisy cafeteria and found the software worked reliably in virtually every scenario.At this point, it appears the team is positioning the SoundWave software as an add-on to computers, serving to fill in some of the gaps in other gesture based systems (such as Microsoft’s Kinect) that rely on cameras and other sensors. They are set to submit a paper for review describing the SoundWave system at the upcoming ACM SIGCHI Conference on Human Factors in Computing. Citation: Researchers use Doppler Effect for computer gesture control (2012, May 7) retrieved 18 August 2019 from https://phys.org/news/2012-05-doppler-effect-gesture.html SoundWave allows non-contact, real time in-air gesture sensing on existing commodity computing devices.
Journal information: Biology Letters New evidence suggests some birds gave up flight to become better swimmers Explore further Most drivers upon encountering birds in the roadway assume that the birds are attempting to gauge their speed and then take flight just before they arrive. This new study by the pair in France suggests that’s not how it works at all—instead, birds note how fast cars travel over many days, weeks, months, etc. and build a memory map based on the average speed of such vehicles. When a car approaches, they then pull that data from their brains and use it to decide when to fly away when a car approaches.The researchers found this out by using a stopwatch to measure how much time birds took to take off from the roadway ahead of them as they drove, which they called the Flight Initiation Distance (FID) and then by stopping to measure the distance traveled. They then set about changing their speed relative to the speed limit, sometimes driving under, over or at the set limit. They also tested birds on different roads with different posted limits, from 20 to 110 kmph. In so doing, they found that the birds studied did not try to guess how fast an individual car was traveling, but instead relied on average speed estimates they’d learned from observing traffic patterns on different roads. They also found that the birds tended to take flight earlier if they were standing in the middle of the road rather than to the side.In all the team recorded 134 instances of birds taking flight, with over 20 species measured. They noted that larger or heavier birds tended to have longer FIDs then did small agile birds and that FIDs grew longer for all species as the speed limit increased. They suggest most collisions with birds on roadways come about due to drivers exceeding the speed limit, catching the birds by surprise. Citation: Investigation reveals birds on roads adapt to speed limits (2013, August 21) retrieved 18 August 2019 from https://phys.org/news/2013-08-reveals-birds-roads-limits.html (Phys.org) —Two biologists from Canada working in France have found that birds that land on roads adapt to average highway speeds—the higher the speed limit, the sooner they take flight when a car approaches. In their paper published in the journal Biology Letters, Pierre Legagneux and Simon Ducatez of the University of Quebec and McGill University respectively, describe the field study they conducted timing birds on roads in France. More information: European birds adjust their flight initiation distance to road speed limits, Biology Letters, Published 21 August 2013 DOI: 10.1098/rsbl.2013.0417AbstractBehavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals’ mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals’ ability to respond adaptively to local speed limits. © 2013 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
A massive, very young clump in a disk galaxy at z = 1.987. Credit: Nature 521, 54–56 (07 May 2015) doi:10.1038/nature14409 (Phys.org)—An international team of space scientists has identified and observed the early stages of the creation of a star-forming clump, the first ever observed. In their paper published in the journal Nature, the team describes how they analyzed imaging and spectroscopy from the Hubble Space telescope to identify the clump, which they believe is likely to one day form a star. © 2015 Phys.org Citation: Researchers report first observation of early stages of creation of a star-forming clump (2015, May 7) retrieved 18 August 2019 from https://phys.org/news/2015-05-early-stages-creation-star-forming-clump.html As the team reports, star forming clumps come about in dense clouds of gas and dust which are known as dark nebulae—in such clouds, particularly in dense portions, the materials tend to coalesce due to gravitational attraction, into clumps—these clumps eventually evolve into proto-stars, and then finally stars. The galaxy under observation (in the cluster CL J144910856) was calculated to have come into existence approximately three billion years after the Big Bang—making it less than ten million years old. Dark nebulae that produce stars are known informally as star factories and the team suggests that they are responsible for the formation of the central bulge in spiral galaxies. They estimate the clump they have been studying has up to a billion bits of material and note that it was only because of the very high resolution offered by the Hubble telescope that they were able to make the discovery at all. They also suggest that their observations indicate that star formation regions are rare, but when they do exist, tend to have a very long lifespan. Thus far, they report, they have studied 68 galaxies in the cluster for signs of rapid star formation.It is hoped that the finding by the team will lead to a better understanding of star formation and by extension, galaxy formation, particularly in the early years of the universe. The clump under observation in this latest observation is believed to be very young, which could offer clues as to its initial state—currently the process by which clumps start to form is not really understood.The researchers suggest that many more such clumps, particularly larger samples, will need to found and studied before true insights into the nature of early star formation can be gained. Image: Hubble eyes galactic refurbishment This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: An extremely young massive clump forming by gravitational collapse in a primordial galaxy, Nature, 521, 54–56 (07 May 2015) DOI: 10.1038/nature14409 . Arxiv: http://xxx.tau.ac.il/abs/1505.01290AbstractWhen cosmic star formation history reaches a peak (at about redshift z ≈ 2), galaxies vigorously fed by cosmic reservoirs are dominated by gas and contain massive star-forming clumps, which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges. Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses, coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies. Explore further Journal information: Nature
(Left) The different molecular structures of the two natural base pairs (black) and the artificial base pair (red and blue) cause the base pairs to absorb light at different wavelengths, as shown at right. The average solar spectrum reaching the Earth’s surface is shown in orange, and the emission spectrum from standard fluorescent lighting is in yellow. Credit: Pollum et al. ©2016 American Chemical Society To investigate how this light absorption difference may affect living cells, the researchers in the new study performed an experiment with living cancer cells from human skin (epidermoid carcinoma cells). When exposed to a low dose of near-visible light, cells that had not been treated with the artificial nucleoside d5SICS exhibited no change in cell survival. Cells that had been treated with the artificial nucleoside, but not exposed to near-visible light, were similarly unaffected. But cells containing the artificial nucleoside that were briefly exposed to near-visible light exhibited a substantial decrease in cell proliferation, indicating that the artificial nucleoside had photosensitized these cells to near-visible light, resulting in photochemical damage. (Left) When exposed to low doses of near-visible light, living skin cancer cells that contain d5SICS exhibit a large decrease in cell proliferation compared to those not exposed to the light. (Right) Cells with d5SICS exposed to near-visible light show high levels of reactive oxygen species (ROS), as seen by the fluorescence of the ROS dye, compared to cells with d5SICS that were not exposed to the light. Credit: Pollum et al. ©2016 American Chemical Society Explore further Citation: Unintended consequences of creating the world’s first semisynthetic organism (2016, September 12) retrieved 18 August 2019 from https://phys.org/news/2016-09-unintended-consequences-world-semisynthetic.html © 2016 Phys.org Based on further investigation, the researchers think that one of the most probable mechanisms of the light-induced damage is that light exposure produces reactive oxygen species (ROS) inside the cells. High levels of ROS are known to cause cell damage, and the living cells containing the artificial nucleoside exhibited much higher levels of ROS upon exposure to near-visible light than untreated cells did.Overall, the results illustrate the complexities involved in the ways that making even a small modification to an organism’s genetic code may have far-reaching and unforeseen consequences for the entire organism.The upside, however, is that some of the unforeseen consequences may have benefits if used in a controlled way. For instance, the researchers are currently investigating how the phototoxicity of the artificial nuceloside could be used as a method to treat cancer.”The significant phototoxic activity of d5SICS in epidermoid carcinoma cells has the potential to open new opportunities for its use in topical photodynamic therapy applications, as our group and others have recently proposed for several nucleobase analogues,” Crespo-Hernández said.The authors acknowledge funding from the National Science Foundation CAREER Program (Grant CHE-1255084 and CHE-1539808). Chemists create mimic of key vision protein More information: Marvin Pollum et al. “Unintended Consequences of Expanding the Genetic Alphabet.” Journal of the American Chemical Society. DOI: 10.1021/jacs.6b06822 Journal information: Journal of the American Chemical Society (Phys.org)—In 2014, the incorporation of two artificial letters of genetic code into the DNA of Escherichia coli gave the bacteria the distinction of becoming the world’s first stable semisynthetic organism. The modification was intended to illustrate the possibility of enabling organisms to incorporate and replicate an artificial base pair for the future biosynthesis of novel proteins. But now in a new study, scientists have discovered that the artificial base pair has an unintended consequence on living cells: phototoxicity. The new results show that the artificial base pair makes living cells more susceptible to damage from low doses of sunlight and standard fluorescent light bulbs, leading to a significant decrease in cell survival and growth.The study, titled “Unintended Consequences of Expanding the Genetic Alphabet,” is published in a recent issue of the Journal of the American Chemical Society by a team of researchers led by Carlos E. Crespo-Hernández from Case Western Reserve University, along with coauthors from Case Western and Columbia University.”There is currently an ongoing quest to genetically modify living cells and organisms with different purposes,” Crespo-Hernández told Phys.org. “Our work clearly cautions scientists that care must be exercised when efforts are made to expand the genetic alphabet, especially if the synthetic organisms may be exposed to light—a fact that has been hitherto overlooked.”The artificial base pair consists of two nucleosides (which are nucleotides without a phosphate group) called d5SICS and dNaM. These artificial nucleosides have different chemical structures than the natural nucleosides, which are those made of the adenine, guanine, thymine, and cytosine nucleobases. Due to their different chemical structures, the artificial and natural nucleosides absorb light at different wavelengths. The artificial nucleosides strongly absorb light with wavelengths in the near-visible range, or just under 400 nm. In contrast, natural nucleosides absorb light most strongly at higher energies, those with wavelengths less than 300 nm. Since everyday lighting, such as the sunlight that reaches Earth’s surface and fluorescent light bulbs, contains much more light in the near-visible range than in the higher-energy ultraviolet range, we receive significantly greater exposure to light with near-visible wavelengths. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
(Top) The TRES RV measurements of KELT-20b with the best fit model shown in red. The residuals to the fit are shown below. (Bottom) The RV measurements phase-folded to the global fit determined ephemeris. The predicted RM effect is shown at 0.25 phase. The residuals are shown below. Credit: Lund et al., 2017. Citation: New ‘hot Jupiter’ with short orbital period discovered (2017, July 12) retrieved 18 August 2019 from https://phys.org/news/2017-07-hot-jupiter-short-orbital-period.html ‘Hot Jupiter’ transiting a rapidly-rotating star discovered © 2017 Phys.org More information: KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603, arXiv:1707.01518 [astro-ph.EP] arxiv.org/abs/1707.01518 (Phys.org)—An international team of astronomers reports the discovery of a new “hot Jupiter” exoplanet with a short orbital period of just three and a half days. The newly detected giant planet, designated KELT-20b, circles a rapidly rotating star known as HD 185603 (or KELT-20). The finding was presented in a paper published July 5 on arXiv.org. Explore further The new planet was identified by a group of researchers led by Michael Lund of the Vanderbilt University in Nashville, Tennessee. The astronomers observed HD 185603 using the KELT-North telescope in Arizona to identify the initial transit signal of a potential planet. The observations were made as part of the Kilodegree Extremely Little Telescope (KELT) survey, which is dedicated to searching for transiting exoplanets around bright stars.The observational campaign was carried out from May to November 2014, and allowed the scientists to identify KELT-20b as an exoplanet candidate. Afterwards, the researchers analyzed archival data and conducted follow-up observations and high-resolution imaging of the object, which resulted in confirming the planetary status of KELT-20b.”We identified the initial transit signal in KELT-North survey data. Archival and follow-up photometry, the Gaia parallax, radial velocities, Doppler tomography, and adaptive optics imaging were used to confirm the planetary nature of the companion and characterize the system,” the authors wrote in the paper.According to the study, KELT-20b has a radius of about 1.73 Jupiter radii and a maximum mass of 3.5 Jupiter masses. It orbits its host every 3.47 days at a distance of approximately 0.05 AU. The planet’s equilibrium temperature is about 2,261 K.The derived parameters of KELT-20b indicate that is belongs to group of planets known as “hot Jupiters.” These exoworlds are similar in characteristics to the solar system’s biggest planet, with orbital periods of less than 10 days. They have high surface temperatures, as they orbit their host stars very closely.The researchers emphasized that the newly discovered planetary system is extraordinary in several ways and that the planet itself is unusual when compared to other “hot Jupiters.””The KELT-20 system represents one of the most extreme transiting hot Jupiter systems, and indeed, one of the most extreme transiting exoplanet systems yet discovered by several measures. The host star is both exceptionally bright (V ∼ 7.6), and exceptionally hot (Teff ~ 8,700 K). It is only the sixth A star known to host a transiting giant companion. The planet itself is on a relatively short period orbit of P ~ 3.5 days, and thus receives an extreme amount of stellar insolation, resulting in an estimated equilibrium temperature of ∼ 2,250 K,” the team concluded.They added that KELT-20b is a great example of a “hot Jupiter” suffering from extreme stellar irradiation, particularly in ultraviolet wavelengths. Therefore, the planet is an excellent target for detailed follow-up observations and characterization. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Explore further More information: Salma Ghezal et al. Embalmed heads of the Celtic Iron Age in the south of France, Journal of Archaeological Science (2018). DOI: 10.1016/j.jas.2018.09.011 © 2019 Science X Network A team of researchers from University Paul-Valéry Montpellier and UMR-IMBE, Université d’Avignon has found evidence of possible embalming of severed heads by Iron Age Celts living in southern France. In their paper published in Journal of Archaeological Science, the group describes their study of skull fragments excavated at a dig site near Le Cailar, in southern France, and what their analysis found. Pictures of a. Total assemblage b. CLR K16 R9 286 exterior surface c. CLR N17 R3 53 interior surface cranial fragments (after Ghezal and Gosnell). Credit: Journal of Archaeological Science (2018). DOI: 10.1016/j.jas.2018.09.011 Skull fragments with carved long, deliberate lines found at Gobekli Tepe Citation: Skull fragments suggest Iron Age Celts in southern France tried to embalm severed heads (2019, February 5) retrieved 18 August 2019 from https://phys.org/news/2019-02-skull-fragments-iron-age-celts.html The researchers were studying skull fragments uncovered at Le Cailar—to date, over 100 have been found. The skulls are believed to be those of enemy combatants who lost their heads after losing their lives in battle. The fragments have been dated back to the third century BC—a time when the town was a Celtic settlement.The researchers report that many of the skulls had cuts indicating they had been decapitated, and some also had marks suggesting the brains had been removed. In some cases, tongues had also been removed. To learn more about the history of the skulls, the researchers ground up small portions of several specimens into dust, and then subjected the dust to gas chromatography-mass spectrometry testing. They report that they found small amounts of diterpenoic compounds in several of the fragments, which are molecules that are produced when conifer resins break down, typically when heated. They also found evidence of cholesterols and fatty acids. As a control, the researchers performed the same tests on animal skulls that had been dug up at the same dig site—none of them had evidence of conifer resin.The researchers suggest the resin within the skull fragments resulted from dipping the skulls in a resin-based liquid as a means of slowing decay—a form of embalming. They note also that all of the skull fragments were found inside the walls of the compound, suggesting that the heads had been mounted for those living inside, rather than as a means of frightening would-be attackers.The researchers also report that they have not yet found any evidence that might explain the reason for embalming the heads, but suggest it might have been a means of showing respect to well-known warriors. The hope to learn more as excavation continues at the site. Journal information: Journal of Archaeological Science This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
— Modern science is largely a team sport, and over the past few decades the makeup of those teams has shifted, from small groups of collaborators to ever larger consortiums, with rosters far longer than that of the New England Patriots. Answering big questions often requires scientists and institutions to pool resources and data, whether the research involves detecting gravitational waves in deep space, or sorting out the genetics of brain development. Psychologists have found that people working in larger groups tend to generate fewer ideas than when they work in smaller groups, or when working alone, and become less receptive to ideas from outside. Why that would be isn’t entirely clear, but it runs counter to intuition, said Suparna Rajaram, a professor of psychology at Stony Brook University. Read the whole story: The New York Times But that shift has prompted scientists to examine the relative merits of small groups versus large ones. Is supersizing research projects the most efficient way to advance knowledge? What is gained and what, if anything, is lost?
Ever thought of Ramayana depicted entirely through paintings? Well, more than 101 Ramayana based paintings are on display at National Museum titled as Rama Katha — The story of Rama through Indian miniatures.The paintings created between 17-19 century depicts various parts of Valmiki’s story like, the Portrait of Rama, Hanuman carrying the Dongiri mountain Rama breaking the Shiva’s bow in king Janak’s court, Rama, Laxman and the golden deer, fire ordeal of Sita, Ravan on his golden throne among others. Also Read – ‘Playing Jojo was emotionally exhausting’The paintings also throw light on varied interpretations of the same story across stylistic genres like Pahari style, Kalighat style, Rajasthani style, Moughal style and many more. The paintings have been collected from various parts of India and more than 70 paintings are on display for the first time. The selection of art work has been done carefully so that each style is exhibited and viewers can compare, understand and imbibe the styles.The exhibition promises to be an experience of different styles of miniature paintings. Later this year, these paintings will travel to Royal Museum of Art and History at Brussels in Belgium, to be displayed.
Kolkata: Union Ministry of Ayurveda, Yoga & Naturopathy, Unani, Siddha and Homeopathy (AYUSH) has decided not to give permission to the state governments to open any AYUSH medical college and hospital for the next two years.The Centre, however, claimed that the move has been made to carry out a comprehensive drive to enhance existing infrastructure of the AYUSH medical colleges.For the next two years, the AYUSH Ministry will not accept any applications from any state government. The director of Ministry of AYUSH has already written to the chief secretaries of the states in this regard. Also Read – Heavy rain hits traffic, flightsState governments need to take no-objection certificate from the Centre for setting up an AYUSH medical college. The Union ministry has also decided not to construct any medical institutions under its fold for the next two academic years, as they will concentrate more on the development of existing infrastructure of all these hospitals. In a recent notification issued by the Ministry of AYUSH, all the state governments and universities have been urged not to give consent of affiliation to any institution which is under construction. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe restrictions will be imposed only for the 2019-20 and 2020-21 academic years. The Centre has also requested the states not to receive any fresh application, as the Centre would not entertain any such application.According to sources, there are around 626 AYUSH medical colleges across the country, among which around 17 are in Bengal. According to the ministry of AYUSH, there are areas which require some infrastructural revamp and hence it is the priority of the ministry to put in place adequate infrastructure so that people coming to the hospitals can avail best quality treatment. The ministry, during its inspection of colleges, will examine and assess if they maintain the prescribed standards. There will be a reform in the education system at all the AYUSH medical colleges in the country. According to the sources, the reforms will improve the quality of education, which will have an impact on providing quality healthcare delivery system rendered by the AYUSH system of medicine.The existing AYUSH medical colleges will, however, be able to admit candidates in various undergraduate courses for the next two academic years. The admissions will be made only through the National Eligibility cum Entrance Test (NEET).The notification also mentions that AYUSH National Teachers Eligibility Test is to be conducted for appointment of all teachers in AYUSH institutions and an unique verification code for such teachers will be allotted before their appointment.The main purpose of the initiatives is to bring transparency and improvement in the quality of all the AYUSH institutions. The ministry also takes up initiatives to achieve standards in AYUSH medical education in the country.
BALURGHAT: A local meat seller in Balurghat has been accused of being involved in selling decomposed meat to an inhabitant of the civic area. The buyer, Ajay Chanda, who is a state government employee and a resident of Balurghat Khadimpur, demonstrated before the shop, demanding immediate return of fresh meat in place of the decomposed meat.Law enforcers from Balurghat police station rushed to the spot, hearing about the incident from the locals. A probe has already been initiated by the South Dinajpur Food Security department after receiving the complaint from Chanda. Preliminary investigation has revealed that the accused meat seller, Chhoton Mali, has no authorised trade licence to run the shop and trade. Also Read – Heavy rain hits traffic, flightsOn Monday, Chanda purchased meat from Mali’s meat shop located in Sare Tin Number More area. Bad smell of decomposed meat came out while cooking at night.On Tuesday, Chanda reached the shop with the half cooked meat, demanding replacement with fresh meat. Mali denied him of replacement and the duo got involved in an argument. Locals gathered there to know what the matter was. Police reached the spot after being informed by the locals.
Bollywood heartthrob Salman Khan and young star Harshali Malhotra, who featured together in the latest blockbuster Bajrangi Bhaijaan fly high up over the skies in Old Delhi. Not
More than a month after she was allegedly raped by a neighbour in North-west Delhi, the statement of a
The study also says, if they do go, they are more likely to choose a male doctor and are less likely to be honest with that doctor about their symptoms.The researchers found that men who held traditional beliefs about masculinity — that men should be tough, brave, self-reliant and restrained in their expression of emotion — were more likely to ignore medical problems, or at least put off dealing with them, than women or than men with less traditional beliefs. Also Read – ‘Playing Jojo was emotionally exhausting’“The question that we wanted to answer was, why do men die earlier than women?” said Diana Sanchez from Rutgers University in the US. “Men can expect to die five years earlier than women and physiological differences don’t explain that difference,” Sanchez added in the paper published in the journal Preventive Medicine. For their study, researchers asked about 250 men participants to fill an online questionnaire designed to elicit their opinions about manhood and relative attributes of men and women. They also answered questions about the preference of doctor. The higher they scored on the masculinity scale, the more likely participants were to prefer a male to a female doctor. They were more likely to choose a male doctor, based on the belief that male doctors were more competent than female doctors. Also Read – Leslie doing new comedy special with Netflix“That’s because they don’t want to show weakness or dependence to another man, including a male doctor,” Sanchez explained.The researchers then recruited 250 male undergraduates at a large public university and had them fill out similar questionnaires.Each subject was interviewed by male and female pre-medical and nursing students about their medical conditions.Ironically, the researchers found that men tend to be more honest about their medical symptoms with female doctors, because to be honest about vulnerabilities causes them no loss of status with women.
Kolkata: The state Tribal Development department has undertaken a special intervention programme for the development of vulnerable tribal groups like Shabar (Lodha), Birhore and Toto.The department has conducted a survey following the instruction of Chief Minister Mamata Banerjee. According to the 2011 census, Shabar population in the state is around 40,000, of whom 18,000 reside in Jhargram. There are 1,500 Totos who stay in Madarihat-Birpara block of Alipurduar, while there are 365 Birhores who live in the Ayodhya Hills of Purulia. Also Read – Rain batters Kolkata, cripples normal lifeThe Tribal Development department has provided a special budget of Rs 12.90 crore in the current fiscal for implementation of the schemes. These are likely to enhance their livelihood opportunities, arrest migration and improve social habits. It has been decided that new dwelling houses under Bangla Awas Yojana will be constructed, while the houses that are in bad shape will be repaired or renovated. The state government will also conduct a special drive to provide drinking water in the tribal habitations. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedSelf-Help Groups (SHG) will be set up to provide better livelihood. Cattle and goat rearing, backyard poultry, horticulture and floriculture, orchard and kitchen gardening will be encouraged. Tribal department officials, along with the local Gram Panchayats, will visit the areas to encourage the beneficiaries and make them aware of the various schemes that are being taken up by the state government. Agriculture will be boosted by improving the irrigation system. Special emphasis will be given on the traditional handicraft products and attempts will be made to give them skill training and design development. Artisan clusters will be developed and soft loans will be given to the artisans under various subsidy schemes. It may be mentioned that supply of rice at Rs 2 a kilo by the state government has helped the tribal people enormously. The people are now getting two square meals a day. Awareness campaigns will be launched about the schemes taken up by the state government and how they are going to benefit them.
The ability to smell food may be making you fat, while its absence may trick the body into thinking that it has already eaten, scientists say. Researchers, including those from University of California, Berkeley in the US found that obese mice who lost their sense of smell also lost weight on a high fat diet.The slimmed-down but smell-deficient mice ate the same amount of fatty food as mice that retained their sense of smell and ballooned to twice their normal weight, they said. Also Read – Add new books to your shelfThe team also found that mice with a boosted sense of smell – super-smellers – got even fatter on a high-fat diet than did mice with normal smell.The odour of what we eat may play an important role in how the body deals with calories. If you can not smell your food, you may burn it rather than store it, researchers said.Sensory systems play a role in metabolism. Weight gain is not purely a measure of the calories taken in, it is also related to how those calories are perceived, they said. Also Read – Over 2 hours screen time daily will make your kids impulsive”This paper is one of the first studies that really shows if we manipulate olfactory inputs we can actually alter how the brain perceives energy balance, and how the brain regulates energy balance,” said Celine Riera, a fellow at Cedars-Sinai Medical Centre in Los Angeles in the US.Researchers noted that mice, as well as humans, are more sensitive to smells when they are hungry than after they have eaten, so perhaps the lack of smell tricks the body into thinking it has already eaten. While searching for food, the body stores calories in case it is unsuccessful. Once food is secured, the body feels free to burn it.Researchers used gene therapy to destroy olfactory neurons in the noses of adult mice but spare stem cells, so that the animals lost their sense of smell only temporarily – for about three weeks – before the olfactory neurons regrew.The smell-deficient mice rapidly burned calories up by regulating their sympathetic nervous system, which is known to increase fat burning.The team noted that the mice turned their beige fat cells – the subcutaneous fat storage cells that accumulate around our thighs and midriffs – into brown fat cells, which burn fatty acids to produce heat.Some turned almost all of their beige fat into brown fat, becoming lean, mean burning machines.In these mice, white fat cells – the storage cells that cluster around our internal organs and are associated with poor health outcomes – also shrank in size.Researchers found that the obese mice, which had also developed glucose intolerance – a condition that leads to diabetes – not only lost weight on a high-fat diet, but regained normal glucose tolerance.The study was published this week in the journal Cell Metabolism.
The number of people with serious Yoga-related injuries are on the rise, according to an Australian study that warns people to practice yogic poses with caution. Researchers from Central Queensland University in Australia analysed all yoga injuries presented at emergency departments between 2009 and 2016 in Victoria.They found that Yoga-related injuries that were serious enough to land people in local emergency department rose by almost 80 per cent during that time and ranged mainly from knee injuries, shoulder dislocations to head and neck injuries. Also Read – Add new books to your shelf”I think people know the correct technique, but they might be pushing themselves too early, especially if you look into the influencers on social media,” said Betul Sekendiz of Central Queensland University.”There is a high focus on pictures to attract likes, so people may be pushing themselves without enough preparation or warm up to get into those poses just for the sake of a picture,” said Sekendiz.”I think on social media, the most frequent pose we see females performing is the headstand,” he said. The study found 66 recorded cases of yoga injuries and almost 10 per cent of those injuries were serious enough for the person to be admitted to hospital for further treatment. “I am not saying we should stop doing yoga, but we need to look into what’s going wrong here,” Sekendiz said. Also Read – Over 2 hours screen time daily will make your kids impulsiveAn article published in The New York Times investigating the prevalence of yoga-related injuries found that several factors seem to be related to the rising number of pulls, tears and sprains prevalent among yogis. A major contributing factor is a shift in both those who teach and practice yoga. More than ever before, adults who are mostly otherwise sedentary and unfamiliar with the practice are turning to yoga to improve flexibility and strength. While this can be helpful in many instances when students are properly guided, a tight, inactive or aging body mixed with a vigorous practice or an experienced teacher can also sometimes serve as a recipe for disaster. “As with any other form of physical practice, yoga should be practiced carefully under the guidance of a qualified instructor in order to reduce risk. If you’ve been injured in the past, or have been mostly sedentary, consider skipping some of the riskiest poses all together”, suggests draxe.com.Five ways to avoid injuries1. Gently stretch tight areasStretching (and similar dynamic movements like calisthenics) should always be done mindfully, gently and slowing. Take your time loosening tight areas — such as the hips, calves or hamstring — being careful not to move too quickly into any poses. Try to warm the body up before any vigorous practice with some dynamic stretching, since this helps to loosen muscles that might be prone to pulls. It’s okay to feel mild to moderate resistance while stretching or bending, but be careful not to push past your limits.2. Reduce muscular compensations through regular strength-trainingIn addition to doing yoga, resistance-training and “functional exercise” can help reduce compensations by building strength in weak areas. Focus on regularly doing cardiovascular and full-body resistance exercises several times per week based on your physical abilities. 3. Practice yoga cautiously (Especially if you’re a beginner)You should always practice yoga with a trained and qualified teacher, but still be careful to listen to your body during practice. Don’t assume that any teacher knows exactly how to modify postures to suit your specific needs, and don’t assume that you should be able to bend or move in ways that other students can.4. Consider sticking to gentler stylesIf you’re susceptible to dizziness, muscle cramps or the effects of heat and dehydration, keep in mind that hot yoga (Bikram) might not be the best match for you. Try to ease your way into any yoga practice by attending basic/beginner classes or workshops, or even trying restorative/yin yoga at first which move at a slower pace.5. Use props for supportProps including yoga blocks, straps, blankets or even a wall or chair can really come in handy. These are especially useful for yoga newbies, the elderly or those recovering from injuries.
Kolkata: Election Commission officials would capture videos of Prime Minister Narendra Modi’s election rally at Brigade Parade ground on Wednesday.The commission will also keep a tab on the rally to ascertain if there is any violation of the Model Code of Conduct (MCC). The commission will also carry out an assessment to know if the entire cost of organising the rally has been spent as declared by the state BJP leaders, while taking permission for it. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataThe commission will also monitor to see if the controversial theme song of the party sung by its Asansol MP Babul Supriyo is played during the rally. The song is yet to receive permission from the EC. Meanwhile, Special Central Police Observer Vivek Dubey will hold meeting with all the observers at Siliguri Circuit Bench on Wednesday, to take a stock on the poll-preparedness in the two districts that will go to poll in the first phase on April 11. Also Read – Lightning kills 8, injures 16 in stateSeven companies of Central Forces have been sent to North Bengal for the first phase of polls. The first phase of elections would be held in Alipurduar and Cooch Behar. Sanjay Basu, additional Chief Electoral Officer, said that seven companies have been taken from the existing 10 companies which have been presently deployed in the state. The forces have been sent to the North Bengal districts as a part of the confidence boosting measure.