123 Street, NYC, US 0123456789 info@example.com

上海419论坛,上海龙凤419,爱上海 - Powered by Leondra Scottie!

wvehpdnk

first_img(PhysOrg.com) — Quadrotors, robotic vehicles resembling tiny helicopters, have been demonstrated by a group of scientists in the US. The quadrotors were shown carrying out impressive maneuvers and lifting payloads both singly and in groups working together. Self-assembling vehicles take flight (w/ Video) The unmanned autonomous vehicles (UAVs) were developed by computer science, mechanical engineering and electrical engineering students at the University of Pennsylvania’s General Robotics, Automation, Sensing and Perception (GRASP) laboratory. Each tiny vehicle has a claw-like grip it can use to pick up an object weighing around 0.5 kg, but the vehicles can work in groups to pick up heavier payloads.The Quadrotors are highly maneuverable, and can flip multiple times and fly through windows or between other quadrotors, with only a few centimeters’ clearance on each side. When fitted with Velcro under the vehicle and on a surface, the quadrotors can perch on inclined, vertical or even inverted surfaces. A quadrotor (also called a quadrocopter) is a vehicle lifted and flown by means of four rotors. The quadrotor is maneuvered by adjusting the relative speed of each of the four rotors. Unlike standard helicopters, the blades on quadrotors are fixed pitch. © 2010 PhysOrg.com 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.center_img Explore further The GRASP laboratory is not the only group working on miniature UAVs for lifting payloads. As PhysOrg reported in June, a group in Switzerland has demonstrated a “distributed flight array” of robotic vehicles working together to lift objects. The Swiss group’s robotic vehicles work as a multiple vehicle flight platform and only fly erratically as single units, whereas the Pennsylvania group’s vehicles function well individually. Control of multiple quadrotor robots to cooperatively transport a payload. A gripping mechanism attached to each quadrotor permits grasping of the payload. Work done at GRASP Lab, University of Pennsylvania. Citation: GRASP lab demonstrates quadrotors (w/ Video) (2010, July 16) retrieved 18 August 2019 from https://phys.org/news/2010-07-grasp-lab-quadrotors-video.htmllast_img read more

jvtbbmru

first_img Explore further (PhysOrg.com) — Researchers from the Fordham University in New York have uncovered evidence that what the world has looked to as the iconic Nile crocodile is actually two different species of crocodile that are only distantly related. The new research is published in Molecular Ecology. The researchers, led by Evon Hekka, began this study when a colleague of hers, Michael Klemens from the Wildlife Conservation Society, sent her a DNA sample of some crocodiles that he had been in close contact with in an oasis in Ennedi Plateau, Chad. The travel guide he had been with suggested that they jump in the water and swim with these crocodiles as they were known for their docile behavior. Because of the odd nature of the behavior, Klemens had taken a tissue sample from a dead crocodile located nearby and sent it to Hekka.Hekka had been working on Nile crocodile samples when she received this one from Klemens and when the results came back from the DNA sequencing, she repeated the test because she was convinced that she had done something wrong.Hekka and her team began collecting various different Nile crocodile samples, including museum samples of some 2,000-year-old mummified crocodiles for a total of 180 different samples. It was determined that there was indeed two different species of crocodiles known as Crocodylus niloticus and Crocodylus suchus.All of the mummified crocodile remains were of the C. suchus and indicate that ancient Egyptians recognized a difference in species. The Greek historian Herodotus wrote that Egyptians were selective when choosing crocodiles for their ceremonies and generally chose the tamer and more docile crocodiles.The distinction between the two species will have implications when it comes to conservation. The current range of the C. suchus is shrinking and their numbers are declining. While both species used to overlap in areas, the more aggressive C. niloticus has taken control of the region and pushed the docile C. suchus to more interior regions. The range of the C. suchus is under threat from oil industries and oil extraction and the crocodiles have seen a decline in numbers due to unregulated trading of skin and bush meat.This new evidence shows that C. suchus is much rarer than what was previously known simply as the Nile crocodile. While some areas in West Africa were hoping to be able to increase their trade in skins to increase revenue, this new study is likely to stop that from happening and may even reduce the amount they are allowed to trade. Borneo’s crocodiles ‘no longer endangered’ Nile crocidile (Crocodylus niloticus). Image: Wikipedia. Citation: Nile crocodile is actually two different species (2011, September 15) retrieved 18 August 2019 from https://phys.org/news/2011-09-nile-crocodile-species.html © 2011 PhysOrg.com More information: An ancient icon reveals new mysteries: mummy DNA resurrects a cryptic species within the Nile crocodile, Molecular Ecology, DOI: 10.1111/j.1365-294X.2011.05245.xAbstractThe Nile crocodile (Crocodylus niloticus) is an ancient icon of both cultural and scientific interest. The species is emblematic of the great civilizations of the Nile River valley and serves as a model for international wildlife conservation. Despite its familiarity, a centuries-long dispute over the taxonomic status of the Nile crocodile remains unresolved. This dispute not only confounds our understanding of the origins and biogeography of the ‘true crocodiles’ of the crown genus Crocodylus, but also complicates conservation and management of this commercially valuable species. We have taken a total evidence approach involving phylogenetic analysis of mitochondrial and nuclear markers, as well as karyotype analysis of chromosome number and structure, to assess the monophyletic status of the Nile crocodile. Samples were collected from throughout Africa, covering all major bioregions. We also utilized specimens from museum collections, including mummified crocodiles from the ancient Egyptian temples at Thebes and the Grottes de Samoun, to reconstruct the genetic profiles of extirpated populations. Our analyses reveal a cryptic evolutionary lineage within the Nile crocodile that elucidates the biogeographic history of the genus and clarifies long-standing arguments over the species’ taxonomic identity and conservation status. An examination of crocodile mummy haplotypes indicates that the cryptic lineage corresponds to an earlier description of C. suchus and suggests that both African Crocodylus lineages historically inhabited the Nile River. Recent survey efforts indicate that C. suchus is declining or extirpated throughout much of its distribution. Without proper recognition of this cryptic species, current sustainable use-based management policies for the Nile crocodile may do more harm than good.via Discover 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.last_img read more

skxowwxh

first_imgScreenshot of the e Serial Interception Sequence Learning task in progress. Credit: Hristo Bojinov, Neuroscience Meets Cryptography: Designing Crypto Primitives Secure Against Rubber Hose Attacks, 21st USENIX Security Symposium. 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. This, as the authors point out, represents a turning point in how security experts might treat authentication. Traditionally, it has been about either who you are (biometrics), what you know (passwords) or what you have (tokens).The newly added twist, as the research takes on further development, will also work at authentication based on what you really know but do not know. The research team suggests its authentication category as “a subclass of behavioral biometric measurement.”Bojinov sees the application in high-risk scenarios when the code-holder needs to be physically present, such as to gain access to a nuclear or military facility. “Now, suppose a clever attacker captures an authenticated user. The attacker can steal the user’s hardware token, fake the user’s biometrics, and coerce the victim into revealing his or her secret key. At this point the attacker can impersonate the victim and defeat the expensive authentication system deployed at the facility,” the authors said.The paper, which they intend to present next month at the 21st USENIX Security Symposium in Bellevue, Washington, is called “Designing Crypto Primitives Secure Against Rubber Hose Attacks.” The authors are Hristo Bojinov, Daniel Sanchez, Paul Reber, Dan Boneh, and Patrick Lincoln. The team further explained what they mean by rubber hose attacks: “Cryptographic systems often rely on the secrecy of cryptographic keys given to users. Many schemes, however, cannot resist coercion attacks where the user is forcibly asked by an attacker to reveal the key. These attacks, known as rubber hose cryptanalysis, are often the easiest way to defeat cryptography. We present a defense against coercion attacks using the concept of implicit learning from cognitive psychology.”Bojinov and colleagues designed a game lasting 30 to 45 minutes in which players intercept falling objects by pressing a key. The objects appear in one of six positions, each corresponding to a different key. Positions of objects were not always random. a hidden sequence of 30 successive positions was repeated over 100 times. Players made fewer errors when they encountered this sequence on successive rounds. This learning persisted when the players were tested two weeks later.“We performed a number of user studies using Amazon’s Mechanical Turk to verify that participants can successfully re-authenticate over time and that they are unable to reconstruct or even recognize short fragments of the planted secret.”If another person were to try to discover the sequence by forcing the password holder to play a similar game and watching to see when they make fewer errors, chances would be slim. The sequence consists of 30 key presses in six different positions. Testing 100 users nonstop for a year would result in less than a 1 in 60,000 chance of extracting the sequence.So far, results of their research indicate the game could form the basis of a security system of this nature. Users would learn a sequence unique to them in an initial session and later prove that they know it by playing the same game. Nonetheless, the authors acknowledge that much work remains before the system can be deployed in a user-friendly state. The team hopes to further analyze the rate at which implicitly learned passwords are forgotten, and the required frequency of refresher sessions. (Phys.org) — Security experts are turning to cognitive psychology for fresh ideas on authentication. Hristo Bojinov of Stanford University and others on his team have a new authentication design based on the concept of implicit learning. Implicit learning refers to learning patterns without any conscious knowledge of the learned pattern. An example of this is riding a bicycle. One knows how to ride a bicycle, but cannot explain how. The technique involves, through a crafted computer game, delivering a secret password in the user’s brain without the user consciously knowing what the password is. Hotmail in hot water over password flaw, rushes fix © 2012 Phys.orgcenter_img Citation: Neuroscience joins cryptography (2012, July 19) retrieved 18 August 2019 from https://phys.org/news/2012-07-neuroscience-cryptography.html via Newscientist Explore further More information:last_img read more

jvtbbmru

first_img Bees use colour-coding to collect pollen and nectar More information: Bees use the taste of pollen to determine which flowers to visit, Biology Letters, rsbl.royalsocietypublishing.or … .1098/rsbl.2016.0356AbstractPollen plays a dual role as both a gametophyte and nutritional reward for pollinators. Although pollen chemistry varies across plant species, its functional significance in pollination has remained obscure, in part because little is known about how floral visitors assess it. Bees rely on pollen for protein, but whether foragers evaluate its chemistry is unclear, as it is primarily consumed by larvae.We asked whether the chemical composition of pollen influences bumblebees’ foraging behaviour. Using putatively sweet and bitter pollen blends, we found that chemical composition influenced two aspects of bee behaviour relevant to plant fitness: the amount of pollen collected and the likelihood of subsequently visiting a visually similar flower. These findings offer a new perspective on the nutritional ecology of plant–pollinator interactions, as they show that pollen’s taste may mediate its collection and transfer. Everyone knows that bees visit flowers to collect nectar, which they bring back to their hive; less well known is that the pollen from the flowers that sticks to parts of their bodies (which is carried from flower to flower allowing for pollination) is also used by the bees as a food resource. Also, prior research has shown that flower color helps bees figure out which flower to visit, but now it appears they also rely on the taste of pollen in making their choice.The experiments conducted by the researchers involved filming the activities of six colonies of Bombus impatiens (the common eastern bumblebee) as they flitted from artificial flower to artificial flower, each fitted with an artificial anther and loaded with one of three different types of pollen: neutral cellulose, sweet sucrose or bitter quinine. The idea was to learn more about the preferences of the bees regarding taste—aroma was ruled out as a factor in choosing pollens by offering only pollens that were odorless.The researchers ran multiple trials, each approximately five minutes in duration, with bees that had been tagged to allow for tracking individual activities. As they filmed the bees, the researchers also recorded their body temperatures using thermal imaging. The team found that the bees spent approximately three times as much of their time collecting from the sucrose-covered anthers as they did from those covered in quinine, and 50 percent less time on those covered in cellulose. Still, the bees were persistent, and wound up collecting all the pollen that was available, though they tended to make return trips to flowers with sucrose as their first choice. Interestingly, it was the return trips during which the differences were noted, suggesting that the bees did not taste the pollen till they were in flight, or in some cases in the hive. Credit: Lilla Frerichs/public domain (Phys.org)—A trio of researchers with the University of Nevada has found evidence that suggests bees have different taste preferences when it comes to pollen. In their paper published in the journal Biology Letters, Felicity Muth, Jacob Francis and Anne Leonard describe experiments they carried out with several bee colonies and what they learned by doing so. © 2016 Phys.orgcenter_img Journal information: Biology Letters Citation: Bees found to use pollens’ taste to determine which flowers to visit (2016, July 13) retrieved 18 August 2019 from https://phys.org/news/2016-07-bees-pollens.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.last_img read more

skxowwxh

first_imgTo examine the relationship between sense of agency (SoA) over thoughts (i.e., the experience of being the source of one’s own thoughts) and obsessive-compulsive (OC) symptoms, Fradkin et al. told participants that an imperceptible and nonaudible auditory message (sham) could insert thoughts in their minds and measured whether they reported having experienced inserted thoughts. Participants were informed about the message that they would supposedly randomly hear (e.g., a negative word, such as death, or a neutral word, such as chair) and were instructed to click the mouse whenever they thought they heard it. Participants also completed an OC Inventory. Participants with high OC symptoms were more likely to falsely hear the sham message than were participants with low OC symptoms, showing less SoA over their thoughts. This tendency was not altered by the valence of the thoughts. Low SoA seemed related to surprise (i.e., the extent to which a thought seems out of context, given one’s other thoughts), and participants who reported experiencing out-of-context or surprising thoughts in daily life were more likely to hear the sham message. Thus, context and experience of violated expectations seem to accompany low SoA. These findings suggest that besides the content and appraisals of intrusive thoughts, researchers and practitioners should also focus on the contextual and phenomenological characteristics of intrusive thoughts. Motivations to Experience Happiness or Sadness in Depression: Temporal Stability and Implications for Coping With StressYael Millgram, Jutta Joormann, Jonathan D. Huppert, Avital Lampert, and Maya Tamir Thoughts as Unexpected Intruders: Context, Obsessive-Compulsive Symptoms, and the Sense of Agency Over ThoughtsIsaac Fradkin, Baruch Eitam, Asher Y. Strauss, and Jonathan D. Huppert Individuals experiencing various levels of depression rated their motivations to experience sadness and happiness, their current emotions and stress, and their attempts to regulate or change their emotional reactions. They were assessed three times: before an exam period, during the academic semester, and 1 to 3 months later during an exam period. In all of the assessments, individuals experiencing more depression were less likely to be motivated to experience happiness and more motivated to experience sadness compared with individuals experiencing less depression. Thus, higher motivation to experience sadness and lower motivation to experience happiness seem to be stable predispositions associated with depression. Individuals experiencing more depression and who were less motivated to experience happiness were less likely to sustain happiness when exposed to happy stimuli and to downplay their negative emotions during real-life stressful events (i.e., exams) compared with individuals not experiencing depression. These findings suggest that helping individuals with depression enhance their motivation to experience happiness may promote better adjustment to stress in daily life. Genetic and Environmental Associations Among Executive Functions, Trait Anxiety, and Depression Symptoms in Middle AgeDaniel E. Gustavson, Carol E. Franz, Matthew S. Panizzon, Chandra A. Reynolds, Hong Xian, Kristen C. Jacobson, Rosemary Toomey, Michael J. Lyons, and William S. Kremen Read about research recently published in Clinical Psychological Science: To determine whether anxiety and depression symptoms are associated with a decreased ability to control and modify one’s own behavior in response to a goal (i.e., executive functioning), and to discern the role of genetic influences on this association, Gustavson and colleagues tested more than 500 middle-aged twin pairs. They measured participants’ anxiety and depression symptoms and their executive functioning — general cognitive ability, working memory, ability to inhibit responses, and ability to shift task goals. More anxiety/depression symptoms were associated with poorer executive functioning, and this relationship was mostly explained by genetic influences. However, environmental influences also affected the relationship between depression and executive functioning but not the relationship between cognitive functioning and anxiety. These associations were observed in late middle age, when cognitive abilities begin to decline, suggesting the importance of considering executive functioning when examining the relationship between anxiety, depression, and cognitive decline. Moreover, decline in executive functioning may underlie age-related decline in other cognitive abilities. Psychological interventions for individuals with anxiety or depression may be more successful when they include training in executive-functioning tasks. last_img read more

wvehpdnk

first_imgKolkata: The training of the second batch of Jalosathis has completed on Wednesday, at the Police Training College in Barrackpore.They will be deployed at the jetties to avoid any untoward incident. The state Transport department has improved the infrastructure of the jetties, following a Standard Operating Procedure (SOP).It may be recalled that around 91 Jalosathis had received training in the first batch and they have already been deployed at different jetties. Also Read – Heavy rain hits traffic, flightsThe state Transport department took up the project to improve the infrastructure of jetties, to avoid incidents like the one at Telenipara, that claimed lives when a temporary jetty had collapsed and at the same time, to deploy Jalosathis at all the jetties. The main task of the Jalosathis will be to ensure that the SOP is followed at the jetties and it includes keeping a tab to check overloading of vessels and to ensure safety of passengers. At the same time, they also have to ensure that all passengers put on safety jackets and proper illumination of the area. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedBesides taking up the project of improving infrastructure of jetties, the state government had introduced the Jalodhara scheme to replace the semi-mechanised vessels with properly designed modern ones.The state Transport department will be engaging a total of 626 Jalosathis and they will be undergoing training in phases. Sources said that Jalosathis will be deployed at different jetties in Hooghly, North 24-Parganas, Howrah, South 24-Parganas and 11 jetties of the West Bengal Transport Corporation.last_img read more

uiihphxo

first_imgKolkata: Three youths were killed in a road accident when they were riding on a motorcycle. The incident took place at Tumbani village near Rampurhat in Birbhum on Tuesday morning. The incident caused traffic disruption on Dumka-Rampurhat Road for nearly an hour. The victims have been identified as Bablu Soren (34), Baidyanath Kisku (22) and Chunde Soren (23). Police said that Bablu was riding the motorcycle with the two others as pillion, on their way to Rampurhat from Hariharpur village in Birbhum. When they were crossing Kharbana area, a speeding dumper hit them. The dumper was on its way to Jharkhand when the accident occurred. Also Read – Bose & Gandhi: More similar than apart, says Sugata BoseThe driver of the vehicle fled the spot immediately after the accident, leaving the dumper at the site. All the three victims were rushed to a nearby hospital, where they were declared brought dead. The local residents staged a sit-in demonstration at the spot, protesting against overspeeding of the trucks in the area. According to the police, the victims had received injuries in various parts of their bodies. The exact cause of the accident is yet to be ascertained by the police. According to the preliminary investigation, police came to know that the dumper was moving at a high speed, as a result of which the driver could not control the vehicle. Senior police officers reached the spot after the accident and lifted the demonstration. Initially, the local residents engaged in an altercation with the police officers but later agreed to lift the agitation.last_img read more

skxowwxh

first_imgKolkata: At least 20 shops were burnt to ashes after a major fire broke out at a roadside market in New Town on the wee hours of Wednesday. Though the intensity of the fire was quite high, none was injured due to the incident.According to local residents, around 5 am on Wednesday, residents of canal side of Gouranganagar saw thick smoke coming out from a shop. Immediately, the shop owners, police and fire brigade were informed. But before taking steps, the fire started spreading to other shops. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataAs there was some hotels, LPG cylinders were present inside the shops. As soon as the flames touched the hotels, LPG cylinders started exploding. Local residents claimed that at least three LPG cylinder exploded due to the fire. Upon receiving the news two fire tenders from Bidhannagar Fire Station were pressed in to action. Later, two more fire tenders were sent from Maniktala and Madhyamgram fire station to douse the fire. As source of water was available from the Bagjola canal, fire fighters had no problem to get water to douse the fire. Also Read – Lightning kills 8, injures 16 in stateBut due to the multiple LPG cylinder explosion, it took long time to control the fire. On Wednesday, early morning fire broke out in some Bagjola Canal side shops made of bamboo shed and tin shed in which approximately 10 shops were completely gutted into fire. Two fire tenders were deployed and extinguished the fire. After almost two hours fire was controlled. Later, for almost an hour fire fighters kept on spraying water to douse the fire completely. It is suspected that the fire had occurred due to a short circuit in the electric wires.last_img read more

wvehpdnk

first_imgKolkata: Two persons were arrested in the past two days from Howrah and the city for possessing unaccounted money worth Rs 30 lakh.In both the cases, the police informed the Income Tax department about the unaccounted money confiscated from the accused persons. According to the police, late on Thursday, sleuths from Burrabazar police station got a tip-off about a person carrying huge amount of money. Officers started keeping an eye on the pedestrians at Rabindra Sarani near Raja Katra areas. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataThe police source spotted and identified the man as Shadab Ahmed Siddiquee, who had a bag with him. He was intercepted by the officers at Rabindra Sarani. During questioning several ambiguities were found in his statement. When his bag was searched, officers found it stashed with cash. Siddiquee was immediately taken to Burrabazar police station for interrogation. He was asked to provide necessary documents. As he could not to provide them, officers arrested him. Cops said he was carrying Rs 10 lakh in cash. Also Read – Lightning kills 8, injures 16 in stateLate on Friday, another person was arrested with Rs 20 lakh from near Howrah Bridge. When sleuths from Golabari police station under Howrah Police were checking vehicles, they spotted a person in a taxi with a briefcase. The man identified Purna Chandra Choudhury was questioned by the police officers. As there were several ambiguities in his statement, they searched his briefcase and found Rs 20 lakh in cash. He was immediately detained and taken to the police station. Choudhury was arrested as he was not able to provide any valid document or reason supporting possession of Rs 20 lakh in cash.last_img read more

skxowwxh

first_imgKolkata: Police recovered an elderly women, who was locked up inside an apartment by her daughter-in-law, on Krishna Chatterjee Lane in Bali police station limits on Tuesday.The police said Jyotsna Das Gupta (80) lived with her daughter-in law Sujata in the four-storeyed apartment. Her son had died two years ago. Because of ailment she could not walk without taking support. While leaving her alone at home, Sujata had made arrangments for her medical care. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataThe police did not arrest any one in the case as Sujata and her daughter Indrani Dasgupta tendered an apology and assured the cops that they would never lock up the elderly woman at home. On Saturday, Sujata left for her daughter’s house in Bhadreshwar and she locked up the elderly woman at home. On Sunday, occupants of other apartment saw newspaper were piled outside the gate of the house. They tried to reachout to the elderly woman but they failed and informed the police. Officers from Bally police station arrived on Tuesday morning and they broke open the gate. Cops called up Indrani Dasgupta, the granddaughter of the woman, who was a schoolteacher. Also Read – Lightning kills 8, injures 16 in stateIndrani told the police that often went out leaving her grandmother alone and locking up the apartment from outside. Sujata arrived almost one-and-a-half-hours after the cops informed her about the situation. She opened the room and police found that the elderly woman was sleeping on a cot. The woman is stone deaf and cannot walk without taking support. Both the mother and the daughter admitted their mistake and tendered unconditional apology. The police arranged for doctors who treated the elderly woman.last_img read more