first_img Special nanotubes could improve solar power and imaging technology Explore further Citation: Carbon nanotubes could act as an efficient music speaker (2008, November 3) retrieved 18 August 2019 from https://phys.org/news/2008-11-carbon-nanotubes-efficient-music-speaker.html The team, which consists of scientists Shoushan Fan and colleagues at Tsinghua University in Beijing, China, and Beijing Normal University, hope that the discovery could lead to the development of cheap, flat loudspeakers. Examples of carbon nanotubes´ musical abilities can be heard here and here.To create the nanotube speaker, the researchers sent an audio frequency current through a thin sheet of carbon nanotubes, generating a sound. Unlike standard loudspeakers that generate sound by vibrations in the surrounding air molecules, the nanotube speaker doesn´t emit vibrations. The team used a laser vibrometer to detect vibrations in the sheet, but found nothing.Instead, the nanotube speaker likely works as a thermoacoustic device: when an alternating current passes through the sheet, the sheet experiences rapid temperature oscillations alternating between room temperature and 80 °C (176 °F). These temperature oscillations cause pressure oscillations in the surrounding air, producing the sound, while the nanotube sheet remains static. One advantage of this method is that, even if part of the nanotube sheet breaks, it should continue to emit sound, unlike conventional speakers.This thermoacoustic phenomenon was actually discovered in the late nineteenth century, when scientists passed a current through a thin foil to produce sound, leading to the invention of the “thermophone.” Although the principle is the same, however, the nanotube sheet acts much more efficiently than foil because it doesn´t require nearly as much applied heat to increase its temperature. Specifically, the nanotube sheet´s heat capacity is 260 times smaller than platinum foil, making nanotubes 260 times more efficient and able to produce a louder sound.The Chinese researchers envision several interesting applications for the nanotube speakers. Because the nanotube sheets can be stretched to be visually transparent and still produce sound, they might be fitted over the front of an LCD screen to replace conventional speakers. Another possibility is incorporating the nanotube speakers into textiles to create musical clothes.More information: Xiao, Lin, et al. “Flexible, Stretchable, Transparent Carbon Nanotube Thin Film Loudspeakers.” ASAP Nano Lett., ASAP Article, 10.1021/nl802750z. © 2009 PhysOrg.com (PhysOrg.com) — While carbon nanotubes are widely praised for their strength and electrical properties, no one has thoroughly investigated their acoustic properties, until now. A team of Chinese researchers has found that zapping sheets of carbon nanotubes with an electric current causes the nanotubes to emit sound. Excerpt from a video of Lin Xiao´s nanotube music speaker. The speaker produces sound when a current passes through, due to a thermoacoustic effect. Credit: Lin Xiao, et al. 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

first_img 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. Citation: Research trio suggest intergenerational fertility correlations could reverse low birthrates (2014, January 30) retrieved 18 August 2019 from https://phys.org/news/2014-01-fertile-future.html The models the scientists designed suggest that fertility rates are likely to rise with average family sizes increasing. Credit: comedy_nose Explore further (Phys.org) —A trio of researchers at Stockholm University is suggesting that the current worldwide trend of low birth rates could reverse itself due to intergenerational fertility correlations. In their paper published in Proceedings of the Royal Society B: Biological Sciences, the team describes how they built mathematical models that use correlations between family size and birth rates to illustrate population growth rates in the future. © 2014 Phys.orgcenter_img Journal information: Proceedings of the Royal Society B Human history has shown over thousands of years that there is a correlation between family size and birth rates—people that come from large families tend to have more kids than people who come from small families. Over the past 200 years, however, that trend has been altered—birth control and societal roles has led to radically smaller family size in most countries of the world (the lone exception being sub-Saharan Africa). If the trend continues, it could spell trouble for modern societies as older people begin to outnumber the young—it’s young people, after all, who generally do most of the work in a society. But low birth rates may change, the researchers suggest, due to natural tendencies. They’ve created mathematical models that indicate worldwide population is likely to take one of two paths.In the first scenario, if people from large families have more kids, even if there are far fewer of them, eventually, a shift will occur as each generation produces more offspring than average—at some point they would overtake the lower birthrate people, causing a growth in population.In the second scenario, societal barriers appear that override intergenerational fertility correlations—similar to those that have caused low birth rates today. If the population grew too large for the planet to support, for example, natural processes would cause lower birth rates (or higher death rates) to occur—people would ignore the size of the family they were born into and intentionally choose to have fewer kids, causing population growth rates to slow.Obviously no one knows if societies of the future will keep adding disincentives for having larger than average families–overriding intergenerational fertility correlations—but the models make it clear that if nature is allowed to take its course, it’s very likely that several generations into the future, fertility rates may climb again, presenting governments with a whole new set of problems. The researchers suggest it’s time that other researchers and governments stop ignoring such correlations, as the evidence for it is overwhelming. More information: Martin Kolk, Daniel Cownden, and Magnus Enquist.” Correlations in fertility across generations: can low fertility persist?” Proc. R. Soc. B March 22, 2014 281 1779 20132561; DOI: 10.1098/rspb.2013.2561 1471-2954AbstractCorrelations in family size across generations could have a major influence on human population size in the future. Empirical studies have shown that the associations between the fertility of parents and the fertility of children are substantial and growing over time. Despite their potential long-term consequences, intergenerational fertility correlations have largely been ignored by researchers. We present a model of the fertility transition as a cultural process acting on new lifestyles associated with fertility. Differences in parental and social influences on the acquisition of these lifestyles result in intergenerational correlations in fertility. We show different scenarios for future population size based on models that disregard intergenerational correlations in fertility, models with fertility correlations and a single lifestyle, and models with fertility correlations and multiple lifestyles. We show that intergenerational fertility correlations will result in an increase in fertility over time. However, present low-fertility levels may persist if the rapid introduction of new cultural lifestyles continues into the future.Press release Study on human fertility models find those based on economics the most reliablelast_img read more

first_img In order to make progress for rare diseases, David tells me, he realized that if he didn’t drive things forward than no one would. After being given his diagnosis as a medical student concentrating on oncology, David switched gears and made CD his first order of business. When he observed all the hurdles in the way of progress, he decided to get an MBA at Wharton, developing business contacts and funding sources for the network of CD researchers he was building. He created a community for patients and physicians to collaborate and share high-potential research ideas. In parallel, he began to conduct CD research at Penn and identify top experts to conduct other priority projects. More recently, the CDCN launched a registry of people with CD so they could share patient records and unpublished cases of the disease.An immediate consequence of these efforts was a redefinition of the more deadly form of CD disease—the so-called ‘multicentric’ form that involves several regions of enlarged lymph nodes as opposed to just one. The former consensus held that benign lymph node tumors secreted Interleukin-6 (IL-6), which in turn hyperactivated the immune system and caused widespread organ dysfunction. The new explanation is pretty much the opposite. In other words, an overactive immune system is what seems to cause the tumors, flu-like symptoms and organ system dysfunction in the first place. The job is therefore to first explain the cause of hyperactivation of different proinflammatory cells and proteins (including Il-6), and then identify ways to stop them.In this view, multicentric CD can be seen as a common endpoint that can be expressed by traversing different paths. In some cases it is due to infection with the HHV-8 virus. This particular pathogen happens to express its own Il-6 type protein that, despite having just 40% sequence homology with our own Il-6, still manages to cause havoc. HHV-8 causes about half of the multicentric form of CD and provides one of many important clues. Other cases, which are called “idiopathic multicentric CD”, may be due as yet unknown viral infection, purely autoimmune mechanisms, or even germ-line disturbances in innate immune regulation. One thing that could be a complication involved in the latter is the increasingly common finding of individuals possessing mosaic and chimeric germ lines. Credit: Cell (2016). DOI: 10.1016/j.cell.2016.10.017 (Phys.org)—Dr. David Fajgenbaum is the founder of Castleman Disease Collaborative Network. Its goal is to organize patients with Castleman disease (CD), find an explanation for this rare and enigmatic immunological disorder that involves the immune system attacking vital organs, and beat it. As an orphan disease researcher at Penn, and a sufferer of CD himself, David’s first-person, n-of-1 approach to a medical brick wall has emerged as the new, and only viable blueprint for moving the bar forward in real time. Citation: Checkmate for Castleman disease (2016, November 14) retrieved 18 August 2019 from https://phys.org/news/2016-11-checkmate-castleman-disease.html Immune system B cells play a role in tackling liver cancer and provide a marker for patient prognosis Explore further More information: Yang Li et al. A Functional Genomics Approach to Understand Variation in Cytokine Production in Humans, Cell (2016). DOI: 10.1016/j.cell.2016.10.017AbstractAs part of the Human Functional Genomics Project, which aims to understand the factors that determine the variability of immune responses, we investigated genetic variants affecting cytokine production in response to ex vivo stimulation in two independent cohorts of 500 and 200 healthy individuals. We demonstrate a strong impact of genetic heritability on cytokine production capacity after challenge with bacterial, fungal, viral, and non-microbial stimuli. In addition to 17 novel genome-wide significant cytokine QTLs (cQTLs), our study provides a comprehensive picture of the genetic variants that influence six different cytokines in whole blood, blood mononuclear cells, and macrophages. Important biological pathways that contain cytokine QTLs map to pattern recognition receptors (TLR1-6-10 cluster), cytokine and complement inhibitors, and the kallikrein system. The cytokine QTLs show enrichment for monocyte-specific enhancers, are more often located in regions under positive selection, and are significantly enriched among SNPs associated with infections and immune-mediated diseases. Genetic sequencing and subsequent functional proteomics will be one valuable source of new information here. Once suspect genes are identified they can potentially be expressed in different cells to see what effects different mutants may have on function. These days, it is perhaps just as likely that advanced simulation tools based on molecular dynamics will give the first functional clues about changes in protein folding or function in the cell. David mentioned that 15 patients, himself included are now getting whole genome sequencing done. This is much more useful than the commonly done ‘exome sequencing’ which can miss many important details including polymorphism in the promoter and other regulatory regions that get spliced out before the exomes are generated. Other critical aberrants like gene duplications will generally be missed in exome sequencing as well.A recent series of papers in Cell takes a functional genomics approach to understand variation in human cytokine production. After challenging cells from hundreds of different people with various bacterial, fungal, viral, and non-microbial stimuli, researchers comprehensively identified the cytokine ‘quantitative trait loci’ that influence the major cytokines (Il-6 included) in whole blood, in blood mononuclear cells, and in macrophages. These studies also looked at other different host and environmental factors, like for example, the influence of the gut microbiome. If reformulated more directly to CD patients important information at the individual scale may be obtained. Among other things, this could include better ways to take critical measurements. For example, developing a more uniform sampling protocol that takes into account the known daily, seasonal, and other natural rhythms of the body’s many organ and systems.David is just one of many researchers at Penn, and elsewhere, who are now taking matters into their own hands. I am reminded of Scott Mackler, a former Penn researcher I consulted for some time ago. When diagnosed with ALS, Scott repurposed his labs efforts to focus on his this devastating disease. In checking now, Scott passed back in 2013 after a 15 year battle, but his legacy lives on. Today, several other home grown efforts are achieving incredible results. In one notable case, a mother with no previous medical background, and no initial funding, was able to found a company called Lysogene that in just a few years developed an FDA approved genetic therapy for the Sanfilippo disease that affected her newborn.Another instance is the case of Shirley Pepke, a genomics researcher who developed machine learning tools to tailor treatments for combating her ovarian cancer. In remission now, Shirley took what seemed like a big chance in going against her oncologist’s recommendation of standard chemotherapy to try a new (an non-FDA approved) immuntherapy drug. Although it may not be possible to fully disambiguate exactly which of the Shirleys many different treatments ‘worked’, the important thing for her is that she is in fact now in remission. This general philosophy is in stark contrast to the ‘drug trial centric’ approach where the study is the goal rather than the individual. Perhaps an even more high profile case is that of Tom Marsilje, a research at Novartis who codeveloped an anti-cancer ALK inhibitor now marketed as Zykadia. Tom needed to get into a trial to treat his own colon cancer but was triaged out of it because he happened to have a pre-existing melanoma. A somewhat fortuitous but perhaps inevitable circumstance brought Tom together with Craig Venter who was promptly able to whole genome sequence Tom’s cells. Using the data rendered they are now developing a personalized neoantigen vaccine, an immunotherapy, that may be able to stimulate his own immune cells to attack tumor.In another fortunate turn of events, the Castlemen network is pleased to be partnering with Janssen Research and Development, and Penn, to create the first global patient registry for CD. Fajgenbaum is serving as principle investigator on this new initiative to help defeat Castlemen disease once and for all. © 2016 Phys.org Journal information: Cell 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

first_img Provided by Phys.org A team of researchers at Indiana University has found that a type of nematode offers a positive influence on the dung beetle larval microbiome. In their paper published in Proceedings of the National Academy of Sciences, Cristina Ledón-Rettig, Armin Moczek and Erik Ragsdale describe their study of the relationship between the nematode Diplogastrellus monhysteroide and dung beetles. Citation: Nematodes found to positively influence dung beetle larval microbiomes (2018, October 2) retrieved 18 August 2019 from https://phys.org/news/2018-10-nematodes-positively-dung-beetle-larval.html More information: Cristina C. Ledón-Rettig et al. Diplogastrellus nematodes are sexually transmitted mutualists that alter the bacterial and fungal communities of their beetle host, Proceedings of the National Academy of Sciences (2018). DOI: 10.1073/pnas.1809606115 Horned beetle Onthophagus taurus. Credit: PNAS © 2018 Phys.org Journal information: Proceedings of the National Academy of Sciences In their study, the researchers found that the nematodes take up residence in the genitals of the adult dung beetles. This allows the nematodes to be passed back and forth between adults when they copulate. It also allows the nematodes to be passed to brood balls.Brood balls are wads of herbivore dung that the female dung beetles make—they use them as incubators for their eggs. After the eggs hatch, the larvae eat the ball from the inside out. But material in plants is difficult to digest. As it turns out, the larva gets some help from nematodes.Testing of brood balls showed they were alive with nematodes. But instead of causing problems for the larva, the nematodes were causing a beneficial change to the microbiome inside of the balls. The presence of nematodes caused changes to the levels of some bacteria and fungi living in them—some types of bacteria grew in number, while fungi became scarcer. This benefited the larvae because the bacteria were the kind that break down plant fibers and the fungi were the kind that sometimes infect beetle larvae. Thus, the presence of the nematode made it easier for the larvae to eat, and less likely to be harmed by a fungal infection.To better understand the impact on the microbiome inside the brood balls, the researchers killed the nematodes inside some of them before allowing female dung beetles to deposit eggs. The researchers report that larvae growing without the nematodes developed more slowly into undersized adults.The researchers were not able to isolate the means by which the nematodes changed the microbiome, but suspect they might have been eating the bacteria that competed with the beneficial bacteria, making it easier for the beneficial bacteria to flourish. They also suggest it is possible the worms emit chemicals that have an impact on bacteria and fungus. 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. Microbiome study suggests marine nematodes are not picky eaterslast_img read more

first_img Journal information: Light: Science & Applications , Nature Materials , Physical Review B In-plane coherent control of plasmon resonances in gold nanodisk monomers. a, b Calculated normalized absorption spectra of gold nanodisk monomers with a diameter ranging from 140 to 200 nm for s-polarized in-plane plan wave coming from the right side (dashed line) or both sides (solid line) without phase delay, or with a phase delay of π. “F” and “H” represent fundamental and high-order plasmon resonances. c–e The corresponding spatial distributions of electric-field amplitude |E|, real part Re(Ez), and imaginary part Im(Ez) for the “F” and “H” modes (square and circle signs) of the representative gold nanodisk monomer (D = 160 nm) under asymmetrical and symmetrical in-plane illumination. Under symmetrical in-plane illumination, we can observe phase delay-dependent destructive/constructive interference for the “F” and “H” modes. Credit: Light: Science & Applications, doi: https://doi.org/10.1038/s41377-019-0134-1 Explore further Demonstration of plasmonic switching by dark field (DF) scattering measurement of gold nanodisk monomer and dimer. a Normalized DF scattering spectra of gold nanodisk monomer with a diameter of 200 nm (SEM image) under full and quarter illumination. b The corresponding normalized simulated scattering and absorption spectra. c, d Normalized measured and simulated DF scattering spectra of gold nanodisk dimer with a diameter of 200 nm and a gap size of 30 nm (SEM image) under full and quarter illumination. The red solid curves in c are the smoothing results. The scale bar in SEM images is 200 nm. e, f Polarization diagrams of full and quarter illumination in the DF scattering measurement and simulation for gold nanodisk monomer and dimer. In both experiment and simulation, the excitation is s- or p-polarized and the collection is unpolarized. The black and red double-headed arrows represent the initial polarization and the polarization after focusing, respectively. Credit: Light: Science & Applications, doi: https://doi.org/10.1038/s41377-019-0134-1 Demonstration of electrical-field distribution rule for the 200 nm gold nanodisk monomer and dimer by s-SNOM. a Schematic of the s-SNOM measurement for s–s and s–p excitation–collection configurations. The wavelength of the excitation laser is 633 nm and the incidence angle with respect to the plane of the substrate is 30°. b Calculated normalized absorption spectra of 200 nm gold nanodisk monomer and dimer at incidence angle 30° under asymmetrical (dashed line) or symmetrical (solid line) illumination without phase delay. The gap size in the dimer is 30 nm. c Atomic-force microscopic (AFM) images of gold nanodisk monomer and dimer for s–s and s–p measurements. The red arrow represents the incidence direction of the laser and the blue dashed line represents the central axis of the nanodisk. d, e Experimental and simulated spatial distributions of the amplitude |A|, phase ϕ, and real part of electric-field component Ey in s–s measurement and Ez in s–p measurement for 200 nm gold nanodisk monomer and dimer. Credit: Light: Science & Applications, doi: https://doi.org/10.1038/s41377-019-0134-1 In a recent study, Liyong Jiang and co-workers at the Nanjing University of Science and Technology demonstrated two methods for in-plane illumination of LSPRs as a proof-of-principle in gold nanodisks. The results of their work showed that the LSPRs could be switched into different states by adjusting the incident light to encode logical data into chains in a manner that was hitherto not possible with out-of-plane illumination. The results are now published in Light: Science & Applications. Significant efforts in the past decade were devoted to study light-matter interactions at the nanoscale in plasmonic systems. The ability to control LSPR has led to many practical applications, including pioneering examples such as:Surface-enhanced Raman ScatteringPlasmon waveguidesMolecular rulersBiosensing and bioimagingNanolasersPlasmonic holography Tunnel junctions, and Metalens. More information: Liyong Jiang et al. In-plane coherent control of plasmon resonances for plasmonic switching and encoding, Light: Science & Applications (2019). DOI: 10.1038/s41377-019-0134-1 P. B. Johnson et al. Optical Constants of the Noble Metals, Physical Review B (2002). DOI: 10.1103/PhysRevB.6.4370 M. S. Tame et al. Quantum plasmonics, Nature Physics (2013). DOI: 10.1038/nphys2615 Jeffrey N. Anker et al. Biosensing with plasmonic nanosensors, Nature Materials (2008). DOI: 10.1038/nmat2162 Plasmonic encoding in gold nanodisk chains. a Calculated absorption spectra of gold nanodisk chains consisting of different numbers of nanodisks illuminated by the s-polarized in-plane plan wave coming from right side (dashed line) or both sides (solid line). The diameter of the nanodisk is 140 nm and the separation distance is 30 nm. The destructive and constructive plasmon resonances are represented by green and red colors, respectively. b Spatial distributions of electric-field amplitude |E| for the “F” plasmon resonances (peak position) under symmetrical illumination. c Sliced electric-field amplitude distributions along the chain’s edge (the white dashed line in b). d–g Corresponding spatial distributions of real and imaginary part of Ez when the s-polarized in-plane plan wave comes from the left side (d, f) and right side (e, g) respectively. Credit: Light: Science & Applications, doi: https://doi.org/10.1038/s41377-019-0134-1 During the initial stages of development, scientists focused on controlling LSPR by designing configurations of the plasmonic nanostructures. They understood the size- and shape-dependent LSPR of single plasmonic nanoparticles and coupled plasmonic systems based on the classical Mie theory and well-established plasmonic hybridization models. Additionally, the light beam typically illuminated the sample surface from one direction in conventional optical studies of single and coupled nanoantennas. © 2019 Science X Network Jiang et al. also demonstrated plasmonic switching with dark field (DF) scattering measurements of a gold nanodisk monomer or dimer. In the experimental setup they used a confocal Raman microscopy system to measure the scattering spectra. They then used commercially available software packages to conduct numerical simulations in the study. The simulations included electrical-field distributions, absorption and scattering spectra for gold nanodisks. They simulated the complex electromagnetic parameters for gold and chromium incorporated in the experimental setup, based on previous publications.center_img To engineer the gold nanodisk samples on silicon dioxide/silica (SiO2/Si) substrates, Jiang et al. used electron-beam lithography (EBL) alongside a lift-off process. They completed the fabrication process by coating the substrate surface with a gold film and an underlying chromium (Cr) adhesion layer using electron-beam evaporation. The scientists then studied in-plane coherent control of plasmon resonances in the gold nanodisks and calculated the absorption spectra of gold nanodisk monomers ranging from diameters of 140 to 200 nm; fabricated on the SiO2/Si substrate surface. In the work, they established and experimentally verified the distribution rule of electrical-field components to realize destructive and constructive plasmon resonances in an axisymmetric plasmonic nanostructure. They showed how the in-plane coherent control of plasmon resonances strongly relied on the configuration and symmetry of plasmonic nanostructures, compared with out-of-plane coherent control. This feature can allow freedom in tailoring and engineering multiple plasmon resonances in other axisymmetric plasmonic structures, which include nanospheres, nanorod, nano bowtie and nanostructure polymers. Demonstration of plasmonic switching by dark field (DF) scattering measurement of gold nanodisk monomer and dimer. a Normalized DF scattering spectra of gold nanodisk monomer with a diameter of 200 nm (SEM image) under full and quarter illumination. b The corresponding normalized simulated scattering and absorption spectra. c, d Normalized measured and simulated DF scattering spectra of gold nanodisk dimer with a diameter of 200 nm and a gap size of 30 nm (SEM image) under full and quarter illumination. The red solid curves in c are the smoothing results. The scale bar in SEM images is 200 nm. e, f Polarization diagrams of full and quarter illumination in the DF scattering measurement and simulation for gold nanodisk monomer and dimer. In both experiment and simulation, the excitation is s- or p-polarized and the collection is unpolarized. The black and red double-headed arrows represent the initial polarization and the polarization after focusing, respectively. Credit: Light: Science & Applications, doi: https://doi.org/10.1038/s41377-019-0134-1 Although the ability to control plasmon resonances via out-of-plane illumination has opened a new path to modulate signals, the process has shown limitations. As a result, Jiang et al. reported on in-plane coherent control of plasmon resonances in typical metallic nanoantennas. The scientists provided a proof-of-principle demonstration of plasmonic switching and encoding applications for single and coupled gold nanodisks. To accomplish in-plane coherent control of plasmon resonances in the lab, the scientists proposed two possible experimental setups. One was based on a fiber-waveguide interferometer, which faced challenges during experiments. In comparison, the second method included a more convenient, widely used dark-field confocal microscopy setup. In this, the condition of completely symmetric in-plane illumination could be satisfied early when the input light focused onto the center of the sample. To construct asymmetric in-plane illumination, the scientists blocked three-fourth of the area of the annular aperture. Jiang et al. showed that the setup was suited to study plasmonic nanostructures with sizes comparable to the focused spot size of the incident light beam. Citation: In-plane coherent control of plasmon resonances for plasmonic switching and encoding (2019, March 11) retrieved 18 August 2019 from https://phys.org/news/2019-03-in-plane-coherent-plasmon-resonances-plasmonic.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. Light incident on metallic nanoparticles can initiate the collective motion of electrons, causing a strong amplification of the local electromagnetic field. Such plasmonic resonances have significant roles in biosensing with ability to improve the resolution and sensitivity required to detect particles at the scale of the single molecule. The control of plasmon resonances in metadevices have potential applications in all-optical, light-with-light signal modulation and image processing. Reports have demonstrated the out-of-plane coherent control of plasmon resonances by modulating metadevices in standing waves. In optical devices, light can be transferred along the surfaces for the unprecedented control of plasmons. When oscillations in conducting electrons are coupled with light photons, localized surface plasmon resonances (LSPR) can act as information carriers for nano-sized optical sensors and in computers. , Nature Physics In this way, Jiang et al. demonstrated proof-of-principle plasmonic switching and encoding in the study. They expect more potential applications based on the demonstrated ability for in-plane coherent control of plasmon resonance. For instance, scientists can use the method to study selective surface-enhanced spectra, where the photoluminescence or Raman signal of multiple molecules can be selectively enhanced. This will allow control of the on/off state of multiple plasmon resonances in a common nano-antenna. The scientists propose extending the plasmonic encoding scheme demonstrated in the study to plasmonic imaging, nano lasing and optical communication in nanocircuits. For instance, scientists can combine plasmonic nanostructure chains with different encoding characteristics to build logic gates (for Boolean logic operations) as well as design multichannel waveguides for all-optical information storage and processes. Schematic diagrams of two setups for in-plane coherent control of plasmon resonances. a Fiber-waveguide interferometer. b Dark-field (DF) confocal microscope, where quarter illumination can be satisfied by blocking 3/4 area of the annular aperture. Credit: Light: Science & Applications, doi: https://doi.org/10.1038/s41377-019-0134-1 To image the plasmon resonance modes in gold nanodisks the scientists used a polarization-sensitive s-SNOM technique, which can detect light at the nanometer scale regions directly beneath the tip of the atomic force microscopic (AFM) probe. The scientists used an s-s/s-p geometry scheme and engaged a dielectric (Si) tip for measurements. They illuminated the sample using laser radiation with an incident light of 300 relative to the plane of the substrate. Jiang et al. measured the amplitude and phase of the scattered signal based on the fourth harmonic of the tip-tapping frequency of the AFM tip. They used an analyzer in front of the detector to select the s- or p- polarized component of the scattered light. Researchers publish first review of plasmonic surface lattice resonanceslast_img read more

first_imgKolkata: A 31-year-old youth, Anirban Sarkar, who had attempted suicide by consuming poison along with his mother and younger brother, died in the hospital on Wednesday. The other two are fighting for their lives at the hospital and their condition is stated to be serious.The incident took place in Jadavpur. The deceased’s mother Sathi Sarkar (62) and younger brother Arijit are currently undergoing treatment at MR Bangur Hospital. According to the police, the victims, who are the residents of Ibrahim Road under Jadavpur police station, had attempted suicide probably after they failed to pay a huge bank loan that the deceased’s father had taken before his death. Also Read – Heavy rain hits traffic, flightsPolice said that Dipak Sarkar, Sathi’s husband, had also committed suicide after failing to repay the bank loan. After the death of the house owner, it was up to his family members to repay the loan amount. They had a family shop at Ranikuthi that was not running well, which also contributed to their frustration.According to local sources, the family members were under tremendous mental pressure as the bank employees had been frequently visiting their house. Three of the family members consumed poison on Monday night. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThey were lying unconscious inside their room till Tuesday morning, when some local residents informed the matter to the local police station as the victims did not open the door despite repeated knocks. After being informed, police reached the spot and rescued the victims by breaking open the door. The local residents told the police that goons of the bank had been frequently visiting in connection with the loan that the family had borrowed. This might have led to their depression, police suspect. All the three victims were rushed to MR Bangur Hospital, where Anirban died on Wednesday morning, with the other two battling for their lives. Police have started a detailed probe into the incident. They collected samples from the room where the three had consumed poison. Police are investigating all possible angles into the incident. The investigators will also talk to the bank officials in this regard. The relatives of the victims are also being interrogated by the police.According to police, the family had a loan of around Rs 25 lakh, which they had invested for buying the shop at Ranikunthi.last_img read more

first_imgWe read a book, we love the book. We google it,  we read every back story possible, we watch films/TV shows made on the book, we obsess day and night over it and we go over endless debates and discussions over the plot of the story, about characters, there are a hundred fantasies about the characters. The internet has given rise to the fandoms (fan-kingdoms for those who are not aware) and these are boys and girls (though age hardly matters in such things) who are a little too much in love with their favourite books or writers. Also Read – ‘Playing Jojo was emotionally exhausting’There are endless groups and chat rooms, and Facebook pages and tumbler posts where the fandom meets to discuss, debate and even fight with other fandoms. There are OTPs (one true pairing) where fanboys and girls discuss which character should have ended up with whom, they ‘ship’ these pairs, they make head cannons, stories that are not part of the books in question and are figments of fan’s imagination which turn into fan fictions. . In fact, the popular book series Fifty Shades of Grey was initially a fan-fiction for the Twilight series and has now become a best seller book series. Also Read – Leslie doing new comedy special with NetflixSo in a world where fandoms have taken over the internet, JK Rowling the author of the Harry Potter  series had decided to launch a series of character backstories on her website pottermore.com as a Christmas gift, where she reveals to her fans the history of some of her characters. As expected it has taken the fandom by storm and being a Harry Potter fan girl myself I know the crazy appeal of it. How people have spent hours reading every bit of new knowledge about their favourite characters as Harry Potter even after years of its release is one of the most potent fandoms on the internet. But it also makes one think whether it’s time for the obsession to stop. Shouldn’t we move on and let the characters rest in our hearts instead of letting the obsession go on? And with new stories popping out every day, I wonder when shall it end at?last_img read more

first_imgKolkata: Jadavpur University (JU) will soon come up with a Centre for Disaster Preparedness and Management with the intention of generating awareness about various disasters and suggest measures to reduce its impact. “Our aim is to develop disaster warning systems including self-warning system and low cost disaster prediction system in the Indian context. There will be seminar and workshops where national level and international level experts from different universities and colleges across the globe will be invited who have been working in this area,” said Professor Gupinath Bhandari, Associate Professor, Department of Civil Engineering, JU. Also Read – Heavy rain hits traffic, flightsIt may be mentioned that till date few institutions in the country have introduced courses on disaster management; however, the University Grants Commission (UGC) has approached all the institutions for institutionalisation of the Disaster Management course. The Centre for Disaster Preparedness and Management has been proposed urging the university authorities to appoint a regular faculty of the varsity as its co-ordinator. The initial target group for the workshop will be government and non-government officials directly dealing with the disaster, those who cater their service to society. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killed”However, as disaster management has neither syllabus nor boundary, we will be welcoming all the members,” Bhandari maintained. The civil engineering department that has already organised a workshop on flood management that has seen active participation from various stakeholders is already in talks for collaborating with both the state and the Central government as well as industry for good interactive sessions. “Two private companies have already approached us for a workshop on Structural Retrofitting. Structural audit and health check-up of buildings will be the main points for discussion. We will be showcasing how the strength of a particular building can be assessed through non-destructive process and accordingly suggest measures on how to equip it to withstand such disaster,” a senior professor of civil engineering said. The university will gradually proceed towards institutional courses like Post Graduate and MPhil which are essential for manpower development in Disaster Management. Research work will be carried out for prediction of any kind of predictable and rapid onset of disasters. However, in case of predictable and slow onset disasters, research will be carried out to estimate the time available and the remedial measures for the same. The Centre has got all the necessary permission and is awaiting the nod of the University Court to become fully functional.last_img read more

first_imgKolkata: Kolkata police’s Special Task Force (STF) has arrested two persons for their alleged involvement in smuggling fake currency.Police have seized fake currency notes worth nearly Rs 4 lakh from their possession. It was learnt that the accused were trying to smuggle the fake currency notes to Bihar.They brought the fake notes from Malda. According to police, the accused came to the city to hand over the fake notes to a person from Bihar.Police came to know that the accused would assemble near Strand Road on Monday evening. Also Read – Rain batters Kolkata, cripples normal lifePolice men in plain clothes were on the streets to nab the culprits. When the duo reached the area, they were caught red-handed.Police are interrogating to know the names of other accused involved in the racket.Both of them are the residents of Malda. Police are also investigating if the accused are part of any international smuggling racket.The investigators are not ruling out the existence of an international racket behind this. They are trying to ascertain the route through which the fake currencies would have been smuggledout of the state.On June 26, the city police arrested a person from Chandni Chawk area and seized fake currency notes worth nearly Rs 5 lakh. Police are investigating if there is any connection between the two incidents.last_img read more

first_imgBlack Sabbath are making plans to get back out on the road one last time in 2016. The Heavy metal pioneers have announced details of their ‘final tour’, reported RollingStone magazine. Billed in the band’s press release as “the final tour from the greatest metal band of all time”, The End tour covers a number of North American cities. It kicks off in Omaha, Nebraska on January 20th 2016 and ends on February 25th at New York’s Madison Square Garden, having taken in 17 dates on the way. There will then be seven dates in Australia and New Zealand running from April 15th-30th. The tour does not include any European dates at all, not even their home town of Birmingham in Britain.last_img