Daily Archives: February 21, 2019

In small groups, people follow high-performing leaders

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researchers at the NYU Tandon School of Engineering have cracked the code on how leaders arise from small groups of people over time. The work is detailed in a study, “Social information and Spontaneous Emergence of Leaders in Human Groups,” published in The Royal Society Interface.

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To conduct the research, the team convened several groups of five volunteers each to participate in a cognitive test arranged in 10 consecutive rounds. The task involved estimating the number of dots displayed for just half a second on a large screen. In each round, participants were asked to choose one from multiple answers using a custom-made clicker, without verbally communicating with one another. Because the dots were visible for only an instant, group members, lacking the time to count them, had to venture a guess. However, the experiments were structured so that participants could alter their answers based on the answers of others in their group: once all participants had chosen their initial answers, the screen—viewable by all—displayed the current answers of all members along with their past performance in selecting correct responses. Participants then had a 10-second window in which to change their responses based on those of the others in the group.

The researchers, analyzing how participant responses evolved over the course of the experiment, found that individuals did not choose the simple majority rule, as posited by the wisdom of crowds. Rather, they dynamically decided whom to follow in making decisions, based on how well each group member performed over time. Based on their observations, the researchers inferred a dynamic evolution of the network of interaction, in which participants were nodes and the links were the consequences of social influence. For example, the investigators generated a link from one participant to another if the first had changed his or her answer to that of the second. The speed at which the network grew increased over the course of each of the rounds.

“Individuals used social information more and more over time, and the more accurate the information, the more influence it had over participants’ choices,” said Porfiri. “Therefore, the relationship between participants’ performance and their social influence was reinforced over time, resulting in the emergence of group leaders.”

To discern the influence of social networks within evolving group dynamics, the investigators noted that:

  • Participants were influenced by in changing their answers. On average, participants changed answers to ones that nobody had selected only about 5 percent of the time. (There were more than 9 instances over all rounds in which participants changed answers to those of others and only 0.6 in which they changed answers to those no one had selected.)
  • Participants were more likely to be copied by others if their performances were good, even if their answers differed from those of the group majority.

Nakayama, the lead author, explained that the behavior of small groups is strikingly different than that of much larger gatherings of people.

“Where a large crowd would adopt a simple majority rule, with an increase in the accuracy of performance over repeated interactions, individuals rely more on social than personal information and as a consequence, good performers would emerge as leaders, exerting a stronger influence on others over time, “he said.

Read more at: https://phys.org/news/2019-02-small-groups-people-high-performing-leaders.html#jCp

Source: In small groups, people follow high-performing leaders

Physicists get thousands of semiconductor nuclei to do ‘quantum dances’ in unison

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A team of Cambridge researchers have found a way to control the sea of nuclei in semiconductor quantum dots so they can operate as a quantum memory device.

Quantum dots are crystals made up of thousands of atoms, and each of these atoms interacts magnetically with the trapped electron. If left alone to its own devices, this interaction of the electron with the nuclear spins, limits the usefulness of the electron as a bit—a qubit.

Led by Professor Mete Atatüre, a Fellow at St John’s College, University of Cambridge, the research group, located at the Cavendish Laboratory, exploit the laws of quantum physics and optics to investigate computing, sensing or communication applications.

Atatüre said: “Quantum dots offer an ideal interface, as mediated by light, to a system where the dynamics of individual interacting spins could be controlled and exploited. Because the nuclei randomly ‘steal’ information from the electron they have traditionally been an annoyance, but we have shown we can harness them as a resource.”

The Cambridge team found a way to exploit the interaction between the electron and the thousands of nuclei using lasers to ‘cool’ the nuclei to less than 1 milliKelvin, or a thousandth of a degree above the absolute zero temperature. They then showed they can control and manipulate the thousands of nuclei as if they form a single body in unison, like a second qubit. This proves the nuclei in the quantum dot can exchange information with the electron qubit and can be used to store quantum information as a device. The findings have been published in Science today.

Quantum computing aims to harness fundamental concepts of quantum physics, such as entanglement and superposition principle, to outperform current approaches to computing and could revolutionise technology, business and research. Just like classical computers, quantum computers need a processor, memory, and a bus to transport the information backwards and forwards. The processor is a qubit which can be an electron trapped in a quantum dot, the bus is a single photon that these generate and are ideal for exchanging information. But the missing link for quantum dots is quantum memory.

Atatüre said: “Instead of talking to individual nuclear spins, we worked on accessing collective spin waves by lasers. This is like a stadium where you don’t need to worry about who raises their hands in the Mexican wave going round, as long as there is one collective wave because they all dance in unison.

“We then went on to show that these spin waves have quantum coherence. This was the missing piece of the jigsaw and we now have everything needed to build a dedicated quantum memory for every qubit.”

Read more at: https://phys.org/news/2019-02-physicists-thousands-semiconductor-nuclei-quantum.html#jCp

Source: Physicists get thousands of semiconductor nuclei to do ‘quantum dances’ in unison

Earth’s atmosphere extends much farther than previously thought

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Most people think that the Earth’s atmosphere stops a bit over 62 miles (100 km) from the surface, but a new study based on observations made over two decades ago by the joint US-European Solar and Heliospheric Observatory (SOHO) satellite shows that it actually extends as far 391,000 miles (630,000 km) or 50 times the Earth’s diameter. This makes the Moon a very high altitude aircraft.

Source: Earth’s atmosphere extends much farther than previously thought

Squid could provide an eco-friendly alternative to plastics

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The remarkable properties of a recently-discovered squid protein could revolutionize materials in a way that would be unattainable with conventional plastic, finds a review published in Frontiers in Chemistry. Originating in the ringed teeth of a squid’s predatory arms, this protein can be processed into fibers and films with applications ranging from ‘smart’ clothes for health monitoring, to self-healing recyclable fabrics that reduce microplastic pollution. Materials made from this protein are eco-friendly and biodegradable, with sustainable large-scale production achieved using laboratory culture methods.

“Squid proteins can be used to produce next generation for an array of fields including energy and biomedicine, as well as the security and defense sector,” says lead author Melik Demirel, Lloyd and Dorothy Foehr Huck Endowed Chair in Biomimetic Materials, and Director of Center for Research on Advanced Fiber Technologies (CRAFT) at Penn State University, USA. “We reviewed the current knowledge on squid ring teeth-based materials, which are an excellent alternative to plastics because they are eco-friendly and environmentally sustainable.”

Squid ring teeth are all-rounders

As humanity awakens to the aftermath of a 100-year party of plastic production, we are beginning to heed nature’s warnings—and its solutions.

“Nature produces a variety of smart materials capable of environmental sensing, self-healing and exceptional mechanical function. These materials, or biopolymers, have unique physical properties that are not readily found in synthetic polymers like plastic. Importantly, biopolymers are sustainable and can be engineered to enhance their physical properties,” explains Demirel.

The oceans, which have borne the brunt of plastic pollution, are at the center of the search for sustainable alternatives. A newly-discovered protein from squid ring teeth (SRT) – circular predatory appendages located on the suction cups of squid, used to strongly grasp prey—has gained interest because of its remarkable properties and sustainable production.

The elasticity, flexibility and strength of SRT-based materials, as well as their self-healing, optical, and thermal and electrical conducting properties, can be explained by the variety of molecular arrangements they can adopt. SRT proteins are composed of arranged in such a way that micro-phase separation occurs. This is a similar situation to oil and water but on a much smaller, nano-scale. The blocks cannot separate completely to produce two distinct layers, so instead molecular-level shapes are created, such as repeating cylindrical blocks, disordered tangles or ordered layers. The shapes formed dictate the property of the material and scientists have experimented with these to produce SRT-based products for a variety of uses.

In the textiles industry, SRT protein could address one of the main sources of microplastic pollution by providing an abrasion-resistant coating that reduces microfiber erosion in washing machines. Similarly, a self-healing SRT coating could increase the longevity and safety of damage-prone biochemical implants, as well as garments tailored for protection against chemical and biological warfare agents.

It is even possible to interleave multiple layers of SRT proteins with other compounds or technology, which could lead to the development of ‘smart’ clothes that can protect us from pollutants in the air while also keeping an eye on our health. The optical properties of SRT-based materials mean these clothes could also display information about our health or surroundings. Flexible SRT-based photonic devices—components that create, manipulate or detect light, such as LEDs and optical displays, which are typically manufactured with hard materials like glass and quartz—are currently in development.

“SRT photonics are biocompatible and biodegradable, so could be used to make not only wearable health monitors but also implantable devices for biosensing and biodetection,” adds Demirel.

No squid was harmed in the making of this film

One of the main advantages of SRT-based materials over synthetic materials and plastics made from fossil fuels are its eco-credentials. SRT proteins are cheaply and easily produced from renewable resources and researchers have found a way of producing it without catching a squid.”We don’t want to deplete natural resources and hence we produce these proteins in genetically modified bacteria. The process is based on fermentation and uses sugar, water, and oxygen to produce biopolymers,” explains Demirel.

It is hoped that the SRT-based prototypes will soon become available more widely, but more development is needed.

Demirel explains, “Scaling up these materials requires additional work. We are now working on the processing technology of these materials so that we can make them available in industrial manufacturing processes.”

Read more at: https://phys.org/news/2019-02-squid-eco-friendly-alternative-plastics.html#jCp

Source: Squid could provide an eco-friendly alternative to plastics

why does Singapore Airlines have an embedded camera looking at you on the inflight entertainment system? Just like the Google Nest spy, they say it’s ummm all ok, nothing to see here.

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Given Singapore’s reputation for being an unabashed surveillance state, a passenger on a Singapore Airlines (SIA) flight could be forgiven for being a little paranoid.

Vitaly Kamluk, an information security expert and a high-ranking executive of cybersecurity company Kaspersky Lab, went on Twitter with concerns about an embedded camera in SIA’s inflight entertainment systems. He tagged SIA in his post on Sunday, asking the airline to clarify how the camera is being used.

SIA quickly responded, telling Kamluk that the cameras have been disabled, with no plans to use them in the future. While not all of their devices sport the camera, SIA said that some of its newer inflight entertainment systems come with cameras embedded in the hardware. Left unexplained was how the camera-equipped entertainment systems had come to be purchased in the first place.

In another tweet, SIA affirmed that the cameras were already built in by the original equipment manufacturers in newer inflight entertainment systems.

Kamluk recommended that it’s best to disable the cameras physically — with stickers, for example — to provide better peace of mind.

Could cameras built into inflight entertainment systems actually be used as a feature though? It’s possible, according to Panasonic Avionics. Back in 2017, the inflight entertainment device developer mentioned that it was studying how eye tracking can be used for a better passenger experience. Cameras can be used for identity recognition on planes, which in turn, would allow for in-flight biometric payment (much like Face ID on Apple devices) and personalized services.

It’s a long shot, but SIA could actually utilize such systems in the future. The camera’s already there, anyway.

Source: Cybersecurity expert questions existence of embedded camera on SIA’s inflight entertainment systems