Explore further The researchers from the University of Vienna, Austria, and the University of Oxford in the UK, first trained ten dogs to open a sliding door in a box using either their mouth or paws. They then asked the owners to open the door using either the mouth or hand, and gave the dogs food rewards if they opened the door using the same method (compatible group) or the other method (incompatible group).The results showed that the dogs in the compatible group were able to gain the reward much more easily and with fewer trials than those who had to counterimitate their owners. This strongly suggests that dogs, like humans, learn by automatic imitation.In a second experiment all the dogs were rewarded if they imitated their owners, and in this case the dogs who had been in the incompatible group fared worse than those in the compatible group, making more errors through counterimitation. The researchers say this suggests the imitation depends on “sensorimotor experience and phylogenetically general mechanisms of associative learning” and that imitation in dogs is shaped more by their interactions with people than by their evolutionary history of domestication.All ten dogs were over eight months old and had completed agility, rescue, and obedience training. They were randomly assigned to the two groups, with three border collies, one Australian shepherd and a mixed breed in the compatible group, and four border collies and a mixed breed in the other. The experiments were carried out at the homes of the participants, who all resided in Austria.Leader of the team, Dr Friederike Range, from the University of Vienna, said learning by automatic imitation has evolutionary advantages because animals can learn without having to go through a trial and error process, which always carries a risk. She also said the results suggest the dogs brought to the experiment a tendency to automatically imitate their owners, even when it proved costly to do so.Scientists are interested in automatic imitation because it is pervasive in human life, where it promotes cooperation, and it is thought to be necessary for imitation learning, which may be crucial for the cultural inheritance of behaviors. The results of the study support a theory of learning that suggests a “mirror neurons” system is involved, and that the capacity to imitate develops as an animal learns and interacts with humans, rather than the ability being present from birth. The paper was published in the Proceedings of the Royal Society B and is available online. Automatic imitation is not only a human trait, research finds More information: Automatic imitation in dogs, Proceedings of the Royal Society B, Published online before print July 28, 2010, doi:10.1098/rspb.2010.1142 (PhysOrg.com) — Scientists studying imitative behavior have found that, just like people, dogs learn quickest by automatic imitation. Apart from the budgerigar, this is the first time automatic imitation has been demonstrated in a non-human species. © 2010 PhysOrg.com Image credit: Mdk572, Wikipedia. Citation: It’s official: dogs really do imitate their owners (2010, July 30) retrieved 18 August 2019 from https://phys.org/news/2010-07-dogs-imitate-owners.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: Science DOI: 10.1126/science.1207115 Journal information: Science © 2011 PhysOrg.com (PhysOrg.com) — Anyone who has ever worn eyeglasses for any length of time can surely attest to the annoyance of constantly having to clean off the oil left behind by finger touching. Not only does it dirty the lens, but removal requires a solvent, rather than a simple tissue. Doris Vollmer can relate, and that’s just what got her thinking about the soot given off by her Christmas candles. As a polymer research scientist with the Max Planck Institute in Germany, she knew the soot was water resistant, but what she wanted to know was whether it was oil resistant as well. So, she and her colleagues held a glass slide over a candle and then tested it. In doing so, as she and her team describe in Science, they found that after some tweaking, the result was a truly remarkable repellency material. After discovering that the soot that showed up on the glass slide not only coated the glass in black, making it impossible to see through, they also found that it wasn’t very stable either. Water dripped on it rolled right off, but carried some of the soot with it, which would mean constant reapplication if trying to use it as a repellant. To counter the instability, they coated they soot with silica using a chemical vapor process. Then, to make the black coating clear, the whole works was calcined (heated to bring about a thermal decomposition). The result was a clear omniphobicity (repels both oil and water) coating that could have many uses in commercial products.It turns out the soot is naturally water resistant due to the way its carbon particles align themselves on a surface, much like a fractal type network, where there just isn’t enough space for water or other liquids to pass through. The team found that the bonds were so strong that the material retained its repellency qualities even when blasted with sand or abused in other ways.It’s not clear just yet if the coating will indeed one day be applied to eyeglasses, forever relieving wearers from the vagaries of fingerprints, but the results thus far look promising for treating various metals or glass to create non-stick surfaces for use in a variety of industrial applications. Citation: Simple technique results in surprising repellency results (2011, December 2) retrieved 18 August 2019 from https://phys.org/news/2011-12-simple-technique-results-repellency.html Explore further 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. Japanese researchers turn a crab shell transparent
More information: Towards high-speed imaging of infrared photons with bio-inspired nanoarchitectures, Nature Photonics (2012) doi:10.1038/nphoton.2011.355AbstractExisting infrared detectors rely on complex microfabrication and thermal management methods. Here, we report an attractive platform of low-thermal-mass resonators inspired by the architectures of iridescent Morpho butterfly scales. In these resonators, the optical cavity is modulated by its thermal expansion and refractive index change, resulting in ‘wavelength conversion’ of mid-wave infrared (3–8 µm) radiation into visible iridescence changes. By doping Morpho butterfly scales with single-walled carbon nanotubes, we achieved mid-wave infrared detection with 18–62 mK noise-equivalent temperature difference and 35–40 Hz heat-sink-free response speed. The nanoscale pitch and the extremely small thermal mass of individual ‘pixels’ promise significant improvements over existing detectors. Computational analysis explains the origin of this thermal response and guides future conceptually new bio-inspired thermal imaging sensor designs. 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. Colors of Butterfly Wing Yield Clues to Light-Altering Structures Citation: Researchers make better heat sensor based on butterfly wings (2012, February 13) retrieved 18 August 2019 from https://phys.org/news/2012-02-sensor-based-butterfly-wings.html Journal information: Nature Photonics Explore further In their study, the team used the Morpho sulkowsky butterfly, a native of South America, a species known for its iridescence. It, like most butterflies, has wings that are made up of thousands of tiny tree-like structures made of chitin. When light strikes the branches and folds of the nanosized structures, it’s bounced around causing a multitude of reflections and refractions, partly accounting for the coloring that we see when looking at them. The other part is caused by the chitin expanding (changing its refraction index) when exposed to infrared radiation, which is subsequently converted to visible light. The chitin expands by actually absorbing the infrared light, a property that is of special interest to the team of researchers at General Electric’s Global Research Center; a group who has found they can increase the heat absorption of the chitin by adding a layer of carbon nanotubes. In so doing they discovered the resultant product could sense temperature differences as small as 0.018 °C.Thermal imaging systems are used in night vision goggles to help people see in the dark and in many other devices such as those that detect heat loss from buildings. As more sensitive devices are made, higher resolutions can be had which could lead to sensors able to detect medical conditions earlier, or problems with mechanical machinery. If this new method using fabricated butterfly wings and nanotubes pans out, it would also vastly reduce the cost associated with manufacturing such devices because it would do away with such components as heat sinks and the need to fabricate other micro-components. © 2011 PhysOrg.com (PhysOrg.com) — Scientists have long known that butterfly wings produce their iridescent colors by bouncing light around and between tiny ridges in structures made of chitin. More recently they’ve discovered that the chitin material in their wings also expands when struck by infrared radiation which causes a change in its refraction index, converting it to visible light. Now, by adding a layer of carbon nanotubes to the wing material, the researchers have found they are able to increase the amount of heat absorbed. This discovery, the team writes in their paper published in Nature Photonics, could lead to new kinds of thermal imaging systems. Morpho didius batterfly. Image: Wikipedia.
Journal information: Science © 2013 Phys.org In order for cells in living creatures to function properly, they must have a means for allowing water to pass through from the outside world into their inner structure—through their membranes. This is how they receive nutrients. At the same time, the water that passes through the membrane must be filtered to keep unwanted material from being carried through with the water. How this happens has been somewhat of a mystery because the channels that carry the water (aquporins) are so small—traditional methods only allow for snapshot views. Progress was made a decade ago, however, when a team of researchers developed a technique that allowed for viewing the process by which potassium ions are transported through potassium channels. In this new effort. the joint American-Swedish team took a similar approach to help them capture the process by which Pichia pastoris yeast is transported through an aquaporin 1 protein.The technique involved capturing the process as it happened at ultra-high resolution—in this case just 0.88 Angstroms. This resolution allowed the researchers to see that the process is very similar to the one found by the team that captured the movement of potassium ions. They found that the way hydrogen bonds were shaped prevented protons from passing through the cell membrane along with the water that carried them. Of particular note, they found that two distinct structures, the NPA-signature motif and the selectivity filter caused water molecules to be oriented in just the right fashion to facilitate the passage of the molecules through the pores in the channel while stopping the unwanted protons.The technique the team developed marks a record for high-resolution captures of cell membrane processes, and paves the way for other research efforts looking to determine how water carrying other unwanted material is filtered by channels in cell membranes. Explore further Fold of Aqy1. (A) The six transmembrane helices and the seventh pseudo-transmembrane helix formed by loops B (orange) and E (green). (B) Water molecule positions within the channel (red spheres). The dual-NPA–aquaporin signature motif (bottom box) and the SF (top box) are highlighted. Credit: Science 14 June 2013: Vol. 340 no. 6138 pp. 1346-1349 DOI: 10.1126/science.1234306 More information: Subangstrom Resolution X-Ray Structure Details Aquaporin-Water Interactions, Science 14 June 2013: Vol. 340 no. 6138 pp. 1346-1349 DOI: 10.1126/science.1234306 https://sp2.img.hsyaolu.com.cn/wp-shlf1314/2020/IMG5341.jpg” alt=”last_img” />
Back in 2003 satellite sensor data indicated that the foliage below in the Amazon basin was reflecting back more near-infrared light during a drought year than was recorded in non-drought years. This suggested that more photosynthesis was going on which would mean the Amazon rain forest was greener during the drought than during other times. Other sensor data appeared to back up that result, as the forest appeared to become greener during the dry season each year. Researchers reporting on this apparent oddity suggested in a published paper that the increase in greenness proved that sunlight was the primary driver behind photosynthesis, not water amounts. Since that time other researchers have argued that some other factor must be at play (such as differences in cloud cover) because it simply wasn’t logical to conclude that a rain forest would grow greener during dry times. In this new effort, the researchers have taken a more serious approach to proving that the original satellite data was being interpreted incorrectly.To settle the matter once and for all, the researchers attacked the problem in two ways. The first involved using a ray-tracing technique that allowed for simulating the trajectories of photons striking leaves. Doing so showed that what appeared to be a greening of the Amazon forest was actually an illusion due to shadowing that occurred when the remote sensor was behind the sun. Amazon rainforest more able to withstand drought than previously thought Journal information: Nature Explore further Amazon forest canopy from below. Credit: D.Morton © 2014 Phys.org Citation: Study shows extra Amazon greenness during drought an optical illusion (2014, February 6) retrieved 18 August 2019 from https://phys.org/news/2014-02-extra-amazon-greenness-drought-optical.html (Phys.org) —A diverse group of researchers led by a team out of NASA’s Goddard Space Flight Center has dispelled the notion that the Amazon basin becomes greener during times of less rain. In their paper published in the journal Nature, the team describes how they undertook two separate studies of Amazon foliage and how both showed that the apparent increase in greenness in satellite images was due to an optical illusion. Kamel Soudana and Chrstophe Francois offer some perspective on the team’s findings in an accompanying News & Views piece in the same journal. More information: Amazon forests maintain consistent canopy structure and greenness during the dry season, Nature (2014) DOI: 10.1038/nature13006AbstractThe seasonality of sunlight and rainfall regulates net primary production in tropical forests. Previous studies have suggested that light is more limiting than water for tropical forest productivity, consistent with greening of Amazon forests during the dry season in satellite data. We evaluated four potential mechanisms for the seasonal green-up phenomenon, including increases in leaf area or leaf reflectance, using a sophisticated radiative transfer model8 and independent satellite observations from lidar and optical sensors. Here we show that the apparent green up of Amazon forests in optical remote sensing data resulted from seasonal changes in near-infrared reflectance, an artefact of variations in sun-sensor geometry. Correcting this bidirectional reflectance effect eliminated seasonal changes in surface reflectance, consistent with independent lidar observations and model simulations with unchanging canopy properties. The stability of Amazon forest structure and reflectance over seasonal timescales challenges the paradigm of light-limited net primary production in Amazon forests and enhanced forest growth during drought conditions. Correcting optical remote sensing data for artefacts of sun-sensor geometry is essential to isolate the response of global vegetation to seasonal and interannual climate variability.Press release Oblique view of the Amazon forest from above the canopy. Credit: M.Palace In the second experiment, the team used data from lidar satellite observations—they’re not impacted by sensor geometry because a laser is used instead of sunlight as the source of illumination. The second study agreed with the first—the apparent greening of the Amazon rain forest was a simple optical illusion caused by sun-leaf shadowing effects.This new study appears to settle the matter once and for all, but of course doesn’t settle the argument regarding the primary driver of photosynthesis—something that is becoming increasingly important as global warming causes changes to weather systems in tropical zones. 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.
© 2014 Phys.org Two-dimensional sheets of electronic materials show promise for practical nanoelectronics Journal information: Nature Materials While carbon nanotubes have dominated the headlines in the search for the basis of the next generation of computer chips, scientists have been making inroads using other materials as well—one in particular, MoS2, has shown promise. It’s actually been used to create working electronic devices. Unfortunately, its use in mass producible devices has been limited by the same constraint as that found with carbon nanotubes—the resistance that occurs when attempting to connect the semiconductor to other electronics. The problem comes about because the sheets are so thin, attempting to attach wires has been problematic and research into doping methods has not gone well. In this new effort, the researchers have found a way to change the phase of a sheet of MoS2 from a semiconductor, to metallic, i.e. a fully conducting contact.The idea is that if a tiny section of a MoS2 sheet can be phase shifted to a metallic state, then wires could very easily be connected to it, and that’s exactly what they team has done—they developed a process they call lithiation which modifies the MoS2 to the metallic phase, by exposing the material to n-butyl lithium. To make sure it really works, they successfully built several field effect transistors using the modified sheets.There are still some problems however, the team is having trouble finding a way to accurately phase shift just the part of a sheet they’re after, and because MoS2 is metastable, it tends to shift back to its purely semiconductor phase under certain conditions, and the researchers aren’t sure just yet what exactly those conditions are. The team is working on these issues, of course—one possible solution may be in producing MoS2 differently—creating flakes using exfoliation, perhaps or chemical vapor deposition. More information: Phase-engineered low-resistance contacts for ultrathin MoS2 transistors, Nature Materials (2014) DOI: 10.1038/nmat4080AbstractUltrathin molybdenum disulphide (MoS2) has emerged as an interesting layered semiconductor because of its finite energy bandgap and the absence of dangling bonds. However, metals deposited on the semiconducting 2H phase usually form high-resistance (0.7 kΩ μm–10 kΩ μm) contacts, leading to Schottky-limited transport. In this study, we demonstrate that the metallic 1T phase of MoS2 can be locally induced on semiconducting 2H phase nanosheets, thus decreasing contact resistances to 200–300 Ω μm at zero gate bias. Field-effect transistors (FETs) with 1T phase electrodes fabricated and tested in air exhibit mobility values of ~50 cm2 V−1 s−1, subthreshold swing values below 100 mV per decade, on/off ratios of >107, drive currents approaching ~100 μA μm−1, and excellent current saturation. The deposition of different metals has limited influence on the FET performance, suggesting that the 1T/2H interface controls carrier injection into the channel. An increased reproducibility of the electrical characteristics is also obtained with our strategy based on phase engineering of MoS2. (Phys.org) —A team of researchers with members from Rutgers University and Los Alamos National Laboratory has found a way to get around the problem of metals forming high-resistance when deposited on 2H phase molybdenum disulphide (MoS2). In their paper published in the journal Nature Materials, the team describes how they came up with a process for inducing 2H phase nanosheets to the metallic 1T phase, thereby reducing contact resistance. 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. Crystal structures of the 2H and 1T phases, respectively. In the upper diagram, trigonal prismatic (a) and octahedral (b) coordinations are shown. The lower panel shows the c-axis view of single-layer TMD with trigonal prismatic (a) and octahedral (b) coordinations. Atom colour code: purple, metal; yellow, chalcogen. Credit: Nature Materials (2014) doi:10.1038/nmat4080 Citation: Researchers find a way to reduce contact resistance with molybdenum disulphide nanosheets (2014, September 5) retrieved 18 August 2019 from https://phys.org/news/2014-09-contact-resistance-molybdenum-disulphide-nanosheets.html Explore further
The remarks made by Bhagwat in Rajasthan on Monday that conversion to Christianity was the main objective behind Mother Teresa’s service to the poor were condemned as “rubbish” and “uncharitable” and an attempt to malign her. The Government said it had nothing to do with Bhagwat’s remarks. The Missionaries of Charity trashed Bhagwat’s claim, saying he was “misinformed”.”He is misinformed. It should be absolutely clear that conversion was not going on when Mother was there, nor it is going on now. The whole motive is to serve the poor selflessly, bring joy and dignity into their lives,” Sunita Kumar, spokesperson of the organisation founded by Teresa in 1950, told a news agency in Kolkata. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIA close confidant of the Mother for many years, she said, “I never saw anything like that (conversion) happening. It is all rubbish”.Teresa, who died in 1997 in Kolkata, had won the 1979 Nobel Peace Prize and was beatified as the “Blessed Teresa of Calcutta” in 2003.Institute of the Blessed Virgin Mary (Loreto)’s Sister S M Cyril, who knew Teresa closely, said it was silly and stupid to think like that. “It is completely wrong that they have been propagating conversion. She never hoped that those who are serving will convert to Christianity. She had selfless love for people in her heart and that is why she served them,” said the Padma Shri awardee who has served as the principal of Loreto Day School, Sealdah. The Catholic Church voiced its strong resentment over Bhagwat’s remarks, dubbing it unfortunate.”It is quite unfortunate that the services of such a world renowned Nobel Prize laureate and Bharat Ratna awardee like Mother Teresa being dragged into unwarranted controversies,” President of the Catholic Bishops’ Conference of India (CBCI) Cardinal Mar Baselios Cleemis said.
Grandparents are often extremely fond of their grandchildren but a study says that affection from grandparents may lead to childhood obesity.Grandparents tend to indulge, overfeed and protect grandchildren in their care from physical chores, thus increasing their risk of obesity, found the study.The motive for the action of grandparents is affection and stems from their personal experiences, misunderstanding and poor recognition of the adverse health effects of childhood obesity. Also Read – ‘Playing Jojo was emotionally exhausting’Children cared for by grandparents also consume unhealthy snacks and drinks more frequently.“Our study reveals that grandparents contribute to childhood obesity through inappropriate perception, with many sharing the belief that fat children are healthy and obesity-related diseases only happen in adults,” said co-author Bai Li, research fellow at the University of Birmingham. Grandparents will often assess weight status by comparing their grandchildren with their peers, rather than seeking professional opinion. Also Read – Leslie doing new comedy special with Netflix“The inappropriate behaviour of grandparents, including overfeeding and indulging through excusing the children from household chores, is another contributing factor, and differs greatly from that of parents, carers and school teachers,” Li said in International Journal of Behavioural Nutrition and Physical Activity.“This study highlights the need to include grandparents in future interventions to promote healthy behaviours among children,” said co-author Peymane Adab, professor of public health, University of Birmingham.“It is imperative that we now work with families, stakeholders and Chinese governmental bodies to tackle this pandemic,” Adab said.
Kolkata: State Education minister Partha Chatterjee on Sunday said that the government will conduct a probe and take action if actor Farhan Akhtar lodges a specific complaint regarding an error in a textbook in Bengali language, where legendary athlete Milkha Singh, popularly known as the ‘flying Sikh’, has been depicted wrongly. Instead of Milkha Singh’s photo, the book has used Farhan’s picture, who played the role of the sprinter in the 2013 superhit Bhaag Milkha Bhaag. The actor has requested state Education minister Partha Chatterjee in a tweet to look into the matter. Also Read – Rain batters Kolkata, cripples normal lifeChairman of the syllabus restructure committee Avik Majumdar reiterated that the book is not taught at any government-run school in the state. “The error may be on the part of any publisher of books at the private level. I have talked with the officials of the state Education department and we will hold an inquiry,” Majumdar said. The syllabus restructure committee in the state oversees the books that are taught in government schools across the state. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedIt may be mentioned that a Twitter user, who goes by the name of ‘Lyfe Ghosh’, noticed the goof-up and shared the picture of the textbook page on the microblogging site and tagged the actor.Sharing the picture on Twitter, he wrote: “image of @FarOutAkhtar is portrayed as Milkha Singh in a West Bengal text book. Not at all shocked. Its become a regular incident here (sic).”Taking cognizance of the person’s tweet, Farhan urged Bengal’s minister of School Education to replace the textbook. He wrote: “To the Minister of School Education, West Bengal. There is a glaring error with the image used in one of the school textbooks to depict Milkha Singh-ji. Could you please request the publisher to recall and replace this book? Sincerely.” The actor tagged Trinamool Congress MP Derek O’ Brien in his tweet, who replied promptly on his Twitter handle: “On it. Thanks for the feedback.” Farhan thanked him in another tweet, saying he had tagged the MP because of his strong commitment to education.It may be mentioned that the actor had portrayed the challenging role of the legendary track athlete in Rakeysh Omprakash Mehra’s Bhaag Milkha Bhaag that had hit the theatres in 2013. Milkha Singh, one of the most successful Indian athletes, had scripted history when he took to the track in the 1958 Commonwealth Games.