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Carbon Nanotubes as a SinglePhoton Source

first_img Explore further “A photon correlation experiment measures the probability of arrival of two photons with a given time delay,” Högele explained. “When two photons travel together, an ideal photon correlation setup would detect with a probability of one the arrival of one photon upon the arrival of another. When one of the two traveling photons is delayed, then the photons will arrive consecutively at the detector and the probability of simultaneous photon detection is zero. “The meaning of the vanishing peak at zero time delay is that photons ‘avoid’ each other, and that it is impossible to find a pulse that contains two or more photons. It has been shown previously that such photon statistics cannot be explained using classical Maxwell’s equations; a quantum description of light is necessary to understand the photon antibunching phenomenon.”The researchers found that two different mechanisms ensure the antibunching: Augur processes and low temperatures that suppress the motion of charged particles along the nanotube axis. Together, these two mechanisms lead to a two-photon emission probability as low as 3% at low temperatures. “We were quite puzzled by our first measurement that showed strong antibunching in the photo-emission of single carbon nanotubes,” said Högele. “In consecutive experiments, we identified two key mechanisms that ensure single-photon generation: first, non-linear Auger processes [which cause one out of two pairs of electrons and electron holes to annihilate non-radiatively] play an important role. Second, electron-hole pairs in carbon nanotubes appear to be strongly localized at low-temperatures by trapping centers. The result is a carbon nanotube quantum dot with an anharmonic spectrum.”The researchers hope that these observations could lead to the development of new single-photon sources for applications such as long-distance quantum communication and quantum cryptography. “The potential advantage of using CNTs as single-photon sources is the fact that their emission wavelength can be tuned into the optical communication wavelength window,” said Högele. “The emission wavelength of single-walled carbon nanotubes depends on the tube diameter and is tunable by growth in the range between around 1 and 2 microns.”More information: Högele, Alexander; Galland, Christophe; Winger, Martin; and Imamoğlu, Atac. “Photon Antibunching in the Photoluminescence Spectra of a Single Carbon Nanotube.” Physical Review Letters 100, 217401 (2008).Copyright 2008 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. 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 atomic force microscope image shows a single-walled CNT with a height of 0.8 nm and length of 800 nm. Researchers found that, under low temperatures, CNTs emit one photon at a time, marking the first demonstration of non-classical optical emission from a CNT. Credit: Högele, Alexander, et al. Citation: Carbon Nanotubes as a Single-Photon Source (2008, June 12) retrieved 18 August 2019 from https://phys.org/news/2008-06-carbon-nanotubes-single-photon-source.htmlcenter_img For the first time, a team of researchers from the Institute of Quantum Electronics in Zurich, Switzerland, has observed photon antibunching (the characteristic signature of non-classical light) in CNT photoluminescence. The study, which is published in a recent issue of Physical Review Letters, provides the first demonstration of non-classical optical emission from a CNT. Over the past few years, researchers have identified several different systems that can act as single-photon sources. All these systems have a common feature: they confine the motion of charged particles to a very small space in all three dimensions. Physicists describe such systems with restricted particle motion as “quasi-zero-dimensional.” The corresponding phase-space of localized particles is made into discrete areas due to the laws of quantum mechanics. The Pauli Exclusion Principle prevents two particles from occupying identical quantum states, so that only one particle at a time can undergo a transition between two distinct states. The principle inhibits simultaneous two-photon generation, and ensures that the system generates only a single photon. Physical systems such as atoms, ions, molecules, and quantum dots are quasi-zero-dimensional and operate as single-photon sources. In the new study, the researchers show that the same principle applies to CNTs – despite the fact that nanotubes are spatially extended in one dimension.“The fact that carbon nanotubes are nearly-perfect single photon emitters is surprising,” lead author Alexander Högele told PhysOrg.com. “Single photon emission is characteristic of systems with quantum confinement in all spatial dimensions. Carbon nanotubes, however, are axially extended and represent a one-dimensional model system.”The single-walled CNTs that the team studied had diameters of just 0.8 nanometers, along with an average length of about 500 nanometers. The researchers used a laser to excite individual CNTs at temperatures as low as 4.2 K, and caused them to emit light with a wavelength of around 880 nanometers. At first, the researchers observed that individual CNTs emitted photons at a delay of a few nanoseconds, consistent with the repetition rate in the laser pulse train. The researchers then investigated statistic correlations between such consecutively emitted photons. Significantly, they did not detect any photon correlation at zero time delay (t=0), indicating strong photon antibunching. Carbon nanotubes, as true multi-purpose materials, have potential applications in everything from electrical circuits and drug delivery to golf clubs and space elevators. Recently, physicists have investigated single-walled carbon nanotubes (CNTs) for one more use: as a single-photon source, where they could help make quantum communication networks extremely secure and efficient. On-demand control of terahertz and infrared waveslast_img read more

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Mice Levitated for Space Research

first_img Citation: Mice Levitated for Space Research (2009, September 11) retrieved 18 August 2019 from https://phys.org/news/2009-09-mice-levitated-space.html (PhysOrg.com) — Scientists have managed to levitate young mice in research carried out for NASA. Levitated mice may help research on bone density loss during long exposures to low gravity, such as in space travel and missions to other planets. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further The researchers worked from a number of laboratories around the U.S., including the Jet Propulsion Laboratory in Pasadena, California and the University of Missouri. The research was done on behalf of NASA, and was published in the online journal Advances in Space Research on 6 September 2009.The scientists built a variable gravity simulator consisting of a superconducting magnet that could generate a magnetic field strong enough to levitate the water inside every cell in the mouse’s body. Water is weakly diamagnetic, which means that in the presence of a strong magnetic field the electrons in water rearrange orbit slightly, creating tiny currents in opposition to the external magnetic field. If the external magnet is strong enough, the diamagnetic repulsion of the water in the mouse tissue is enough to exactly balance the force of gravity on the body.Scientists have previously levitated live grasshoppers and frogs, but this is the first time a mammal has been levitated. The mice were confined to a plastic cage, which had a base with holes to allow waste to be removed, and an open top to allow in air, food, water, and to allow the proceedings to be filmed. The cage was not necessary for the levitation, but it did allow the scientists to compare the levitated mice with non-levitated subjects in identical cages.The first subject to be levitated was just three weeks old. The tiny mouse was disturbed and disoriented and began to spin when it kicked out as though trying to find something to hold on to. With no friction to stop the spinning, the mouse became even more disoriented, according to Jet Propulsion Lab physicist Yuanming Liu.The next young mouse was mildly sedated before being levitated, and it was less agitated by the experience. The levitation experiments were repeated a number of times, and showed that the mice quickly adjusted to the conditions, even eating and drinking normally after a few hours of levitation. Even without sedation, the mice became quite comfortable floating in zero gravity.The powerful magnetic field seemed to have no short term effects on the mice, and earlier studies on rats showed there were no ill effects even after 10 weeks’ exposure to strong magnetic fields.The researchers are now applying for research funding that will allow them to study the physiological effects of prolonged exposure to microgravity, and to try to develop countermeasures that astronauts could adopt.More information: Magnetic levitation of large water droplets and mice; Yuanming Liua, Da-Ming Zhub, Donald M. Strayera and Ulf E. Israelssona, Advances in Space Research, http://dx.doi.org/10.1016/j.asr.2009.08.033© 2009 PhysOrg.com Spinning Water Droplets Could Provide Insights into Black Holes, Atomic Nuclei Image credit: Da-Ming Zhulast_img read more

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Electrostatic netting opens a whole new world of malaria vector control

first_img Explore further Fighting mosquito resistance to insecticides More information: “Electrostatic coating enhances bioavailability of insecticides and breaks pyrethroid resistance in mosquitoes.” PNAS 2015 ; published ahead of print August 31, 2015, DOI: 10.1073/pnas.1510801112AbstractInsecticide resistance poses a significant and increasing threat to the control of malaria and other mosquito-borne diseases. We present a novel method of insecticide application based on netting treated with an electrostatic coating that binds insecticidal particles through polarity. Electrostatic netting can hold small amounts of insecticides effectively and results in enhanced bioavailability upon contact by the insect. Six pyrethroid-resistant Anopheles mosquito strains from across Africa were exposed to similar concentrations of deltamethrin on electrostatic netting or a standard long-lasting deltamethrin-coated bednet (PermaNet 2.0). Standard WHO exposure bioassays showed that electrostatic netting induced significantly higher mortality rates than the PermaNet, thereby effectively breaking mosquito resistance. Electrostatic netting also induced high mortality in resistant mosquito strains when a 15-fold lower dose of deltamethrin was applied and when the exposure time was reduced to only 5 s. Because different types of particles adhere to electrostatic netting, it is also possible to apply nonpyrethroid insecticides. Three insecticide classes were effective against strains of Aedes and Culex mosquitoes, demonstrating that electrostatic netting can be used to deploy a wide range of active insecticides against all major groups of disease-transmitting mosquitoes. Promising applications include the use of electrostatic coating on walls or eave curtains and in trapping/contamination devices. We conclude that application of electrostatically adhered particles boosts the efficacy of WHO-recommended insecticides even against resistant mosquitoes. This innovative technique has potential to support the use of unconventional insecticide classes or combinations thereof, potentially offering a significant step forward in managing insecticide resistance in vector-control operations. © 2015 Phys.org Citation: Electrostatic netting opens a whole new world of malaria vector control (2015, September 11) retrieved 18 August 2019 from https://phys.org/news/2015-09-electrostatic-netting-world-malaria-vector.html (Phys.org)—Mosquito-borne infectious diseases are a huge public health burden, which carry high human and economic costs. Malaria, Chikungunya, West Nile virus and dengue are difficult to treat, and controlling the disease vector—mosquitos—is imperative.center_img The WHO recommends the use of four classes of public health insecticides, but widespread use has inevitably resulted in the development of insecticide-resistant mosquitos. Additionally, larval exposure to low residual doses of agricultural insecticide has been a major driver of resistance in mosquitos. Thus, the WHO advises health officials to rotate the use of both agricultural and vector-targeting insecticides to assert control over the expression of resistant genes. Nonetheless, conventional methods of mosquito control are becoming less effective over time, and researchers seek alternatives to existing techniques in an effort to stay one step ahead of adaptation. Now, a group of health and ecological science researchers in Johannesburg, South Africa, and Liverpool, England, have reported in the Proceedings of the National Academy of Sciences the use of an electrostatic coating that binds insecticide particles. The authors report that the method delivers such high levels of insecticides to mosquitos that even those with high levels of resistance are killed effectively. It consists of a coating, originally developed to trap and bind airborne pollen, which is applied on different substrates, including conventional mosquito netting for deployment in households. The coating has an electrostatic charge that binds particles via polarity. Though such techniques have been effectively applied in agriculture, this study is the first to demonstrate efficacy against disease-carrying mosquitos. The researchers tested the electrostatic netting on six strains of Anopheles mosquitos with different methods of adaptive pyrethroid resistance from across Africa. Fluorescent dust tests with the netting showed visual support of high powder transfer efficiency to flying insects, even with very short contact. “Even with a mere 5-second contact and at 15-fold lower dose, the impact of deltamethrin on electrostatic netting was significantly higher than the impact of deltamethrin on a [standard] long-lasting insecticidal net,” the authors write.They applied multiple public health insecticides with the electrostatic coating, successfully transferring them to the polyester fibers of the netting. The researchers note that the application technique has a variety of potential uses and can be applied to other surfaces including walls, via paint. Additionally, electrostatic netting fibers can be washed up to 40 times while retaining their electrostatic charge, extending the active life of the netting. However, the electrostatic netting is not considered by the WHO to be suitable for bed nets, for which only pyrethroid impregnation techniques are approved. It is useful, however, for house-screening products that will not be handled frequently, and the researchers are investigating the use of such nets in Tanzanian households.”In conclusion,” the authors write, “the application of electrostatically adhered particles can boost the efficacy and provide resistance-breaking applications of currently recommended public health insecticides.” Credit: CDC Journal information: Proceedings of the National Academy of Sciences 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

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Hauling antiprotons around in a van

first_imgAntiprotons present a unique way to study the radioactive elements produced at CERN’s ISOLDE ion-beam facility.Credit: Julien Marius Ordan/CERN/Nature Journal information: Nature More information: Elizabeth Gibney. Physicists plan antimatter’s first outing—in a van, Nature (2018). DOI: 10.1038/d41586-018-02221-9 The antiprotons will be created the same way that they are currently made at what has become known as CERN’s antimatter factory, but they will be used in experiments in a nearby building. For that to happen, the antiprotons will have to be boxed up and shipped in a van.Antiprotons are, of course, the opposite twins of protons—they exist sometimes in nature, but do not last long, because when they come into contact with regular matter, they are annihilated. Researchers at CERN create them by firing a proton beam at a metal target—holding antiprotons in a vacuum chamber at just 4 degrees above absolute zero, comparable to intergalactic space, can protect them from annihilation for brief periods.The PUMA team are trying to learn more about the nuclei of large radioactive atoms, and to that end, want to fire antiprotons at them and then study the remnants after both are annihilated. But for that to happen, the team has to develop a means for transporting the antiprotons from the site where they are created to the site where they will be tested—from one lab to another just a few hundred meters away.The plan is to create a trap capable of holding a billion antiprotons for up to a week. The team estimates it is likely to take up to four years to get the trap just right. In addition to providing the workers at ISOLDE with a batch of antiprotons, the project will also establish a technique for other teams working at much greater distances. That will give researchers from perhaps all over the world access to antiproton batches for use in their own experiments. Explore further Citation: Hauling antiprotons around in a van (2018, February 22) retrieved 18 August 2019 from https://phys.org/news/2018-02-hauling-antiprotons-van.htmlcenter_img © 2018 Phys.org A team of researchers working on the antiProton Unstable Matter Annihilation (PUMA) project near CERN’s particle laboratory, according to a report in Nature, plans to capture a billion antiprotons, put them in a shipping container and transfer them to a lab that is conducting experiments collectively called ISOLDE. 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. CERN sets course for extra-low-energy antiprotonslast_img read more

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Phylogenomic analyses shows group of winged insects developed from terrestrial ancestor

first_imgVirtual model of the last common ancestor of Polyneoptera. Credit: Benjamin Wipfler and Evgeny V. Yan. Explore further Polyneoptera represents one of the most prominent lineages of winged insects (Pterygota). There are approximately 40,000 species of them in 10 orders. They include stoneflies, grasshoppers and roaches. The researchers note that they are the only major lineage of winged insects with a cloudy evolutionary history. In this new effort, the researchers sought to fill in many of the gaps that exist in their family tree by conducting a large-scale phylogenomic analyses of both Polyneoptera and Pterygota. This enabled them to trace phylogenetic relationships of 112 samples associated with the typical appearance and lifestyle of the winged insects. Their study also involved studying 106 species and 3014 genes.The researchers report that their analysis revealed that polyneoptera did not evolve from an initial sea creature, but instead, one that lived on the land. This finding contrasts sharply with the view that such insects evolved from creatures that swam into insects that buzzed above the water, such as dragonflies. Also, a sea evolution seemed logical, with wings developing from fins. The evolution of wings from a terrestrial creature would most likely have had to come about due to the advantage some received from falling from a higher place to one that was lower. The researchers furthermore contend that the early land-dweller evolved from an insect that had antennae and a segmented abdomen. Also, it had biting mouth parts that were located beneath the head capsule, which would have been similar to the modern dragonfly. It would also have had stiff forewings making flight difficult and necessitating the development of triangular rear wings.The researchers note that their work was part of the 1,000 Insect Transcriptome Evolution Project (1KITE) which brought together international teams of researchers for the purpose of better understanding the evolutionary history of insects. © 2019 Science X Network Insects took off when they evolved wings Journal information: Proceedings of the National Academy of Sciencescenter_img Citation: Phylogenomic analyses shows group of winged insects developed from terrestrial ancestor (2019, January 15) retrieved 18 August 2019 from https://phys.org/news/2019-01-phylogenomic-analyses-group-winged-insects.html An international team of researchers has found evidence that shows that many modern winged insects developed from a terrestrial ancestor, not from one that lived in the sea. In their paper published in Proceedings of the National Academy of Sciences, the group describe their large-scale phylogenomic analyses of both Polyneoptera and Pterygota and what they found. More information: Benjamin Wipfler et al. Evolutionary history of Polyneoptera and its implications for our understanding of early winged insects, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1817794116 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

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3D culturing hepatocytes on a liveronachip device

first_imgDue to their wider adoption in academic and industrial settings, the bioreactors require optimized materials and conditions for high throughput fabrication. Conditions include replacing the common prototyping material polydimethylsiloxane (PDMS), integrating induced pluripotent stem cell (iPSC)-derived cells on a soft biomaterial that facilitates their growth and minimizing the large dead volume caused by microfluidics reservoirs and tubing of organ-on-chips devices.The novel biomaterial prepared in the study contained two main constituents crosslinked via SPAAC; a cycloocytne-modified hyaluronan (HA-BCN) and a multiarmed azide-modified PEG [p(N3)8]. The BCN reacted with azides (N3) on the 8-armed PEG polymer with terminating N3-moieties to form a stable 1,2,3-triazole. Christoffersson et al. completed chemical reactions under physiological conditions to form the hydrogels with tunable viscoelastic properties. The crosslinking strategy was ideal to fabricate hydrogels for 3D cell culture; as the cells could be encapsulated in the biomaterial without compromising their viability and were suitable for use in microfluidic devices. The scientists used excess SPAAC moieties on the novel biomaterial to attach different ligands including RGD peptides to promote interactions at the cell-material interface.Thereafter, the scientists varied the composition of the two main constituents to understand the resulting viscoelastic properties, such as the storage modulus (G’) and loss modulus (G”) of the hydrogels via oscillatory rheology (technique to measure the viscoelastic behavior of soft materials). They controlled the gelation kinetics of the novel hydrogel at increasing temperatures. Gelation kinetics of the new biomaterial was slow enough for homogenous cell distribution but rapid enough to prevent cell sedimentation. The ability to control gelation kinetics allowed the scientists to consider a variety of biofabrication strategies (e.g. bioprinting) and hydrogel assembly within the microfluidic systems for organ-on-chip applications. (a) Schematic representation of the formation of HA-PEG hydrogels through a strain-promoted alkyne-azide cycloaddition reaction. (b) Photograph of a HA-PEG hydrogel after formation. (c) Frequency sweeps of HA-PEG hydrogels with different BCN to N3 ratios. (d) Gelation time experiment showing the increase of G’ over time during gelation of HA-PEG hydrogels (10:1 BCN:N3) at different temperatures. Credit: Biofabrication, doi: https://doi.org/10.1088/1758-5090/aaf657 Journal information: Biofabrication , Nature Reviews Drug Discovery Liver-on-a-chip cell culture devices are attractive biomimetic models in drug discovery, toxicology and tissue engineering research. To maintain specific liver cell functions on a chip in the lab, adequate cell types and culture conditions must be met, which includes 3D cell orientation and a consistent supply of nutrients and oxygen. Compared with conventional 2D cell culture techniques, organ-on-a-chip devices offer versatility and effective biomimicry suited for advanced applications in drug discovery and medicine. Researchers create a more effective hydrogel for healing wounds More information: 1. Fabrication of modular hyaluronan-PEG hydrogels to support 3D cultures of hepatocytes in a perfused liver-on-a-chip device iopscience.iop.org/article/10. … 088/1758-5090/aaf657, Jonas Christoffersson et al. 27 December 2018, Biofabrication, IOP Science. 2. Controlling hydrogelation kinetics by peptide design for three-dimensional encapsulation and injectable delivery of cells www.pnas.org/content/104/19/7791 Haines-Butterick L. et al. May 2007, PNAS .3. Microfluidic organs-on-chips www.nature.com/articles/nbt.2989 Bhattia S. N and Ingber D.E. August 2014, Nature Biotechnology.4. Organs-on-chips at the frontiers of drug discovery, www.nature.com/articles/nrd4539 Esch E.W. et al. March 2015, Nature Reviews Drug Discovery. , Nature Biotechnology Explore further (a)–(c) Frequency sweeps of (a) agarose, (b) alginate and (c) HA-PEG hydrogels at different concentrations. (d)–(f) SEM micrographs of (d) agarose, (e) alginate and (f) HA-PEG hydrogels showing the morphology of each hydrogel. Credit: Biofabrication, doi: https://doi.org/10.1088/1758-5090/aaf657 Structure of a) HA-BCN with a ratio n/m of 0.19 and b) p(N3)8. Credit: Biofabrication, doi: https://doi.org/10.1088/1758-5090/aaf657 Christoffersson et al. next compared the HA-PEG hydrogels with the well-established 3D cell culture scaffolds – agarose and alginate hydrogels. In order to determine the final viscoelastic properties suited for 3D cell culture experiments, they used oscillatory rheology to examine the different polymer concentrations. The scientists analyzed the composition of the finalized materials using scanning electron microscopy (SEM) images.The liver-on-a-chip design and setup had to meet two key criteria in the study: 1. Allow perfusion (passage of fluid) of cell culture medium across the hydrogel surface for steady nutrient media exchange, to and from the encapsulated hepatocytes. 2. Allow sampling of the perfused media for experimental analysis during ongoing cell culture, without affecting the hepatocytes and the hydrogel.center_img (a) Schematic representation of the liver-on-a-chip device and setup. The device was put on an automatic rocker table to allow perfusion of media and nutrients during cell culture. (b) Depiction of the HepG2 3D cell culture experiments with HA-PEG hydrogels. The HepG2 cells were added to media-suspended p(N3)8 prior addition of HA-BCN. (c) Depiction of the hiPS-HEP 3D cell culture experiments with HA-PEG hydrogels. The hiPS-HEP cells were added to media-suspended p(N3)8 prior addition of HA-BCN. In experiments using either linRGD or cRGD peptide, the HA-BCN was preincubated with 1 μM of corresponding peptide for 1 h prior adding the HA-BCN(RGD) component to the hiPS-HEP/p(N3)8 mixture. Credit: Biofabrication, doi: https://doi.org/10.1088/1758-5090/aaf657 Based on the results, the scientists attributed the higher albumin quantity on the 2D HEP coat to the rate of albumin diffusion within hydrogels; transfer across 2D coat being faster than 3D. The higher concentration of albumin with cRGD motif bound hydrogels, correlated with the increased cell growth and viability observed on the cRGD bound biomaterial surfaces. As a result, the scientists intend to use cyclic forms of RGD peptide to assist hepatocyte stem cell culture on hydrogels prepared for liver-on-a-chip devices in the future. In this way, the study detailed the advantages of using hyaluronan-PEG based hydrogel modified with RGD peptides for 3D cultures of hepatocytes (approximating 13 days) in a liver-on-a-chip setup. As benchmarks of the study, Christofferfsson and co-workers used the commonly available alginate and agarose hydrogels. In the future, the scientists will optimize the viscoelastic properties and the concentration of cell adhesion motifs on the HA-PEG hydrogel system for biomimetic cytocompatibility. The optimized hydrogel system can be combined with the device setup to facilitate physiologically relevant liver-on-a-chip platforms for clinical research in drug toxicology, drug discovery and regenerative medicine. Citation: 3-D culturing hepatocytes on a liver-on-a-chip device (2019, January 17) retrieved 18 August 2019 from https://phys.org/news/2019-01-d-culturing-hepatocytes-liver-on-a-chip-device.html , Proceedings of the National Academy of Sciences (a) Viability and morphology of hiPS-HEP cells after 13 days of culture. Cell viability seems to be dependent on the cell’s ability to attach to the surface, the hydrogel, or to each other. Large structures of hiPS-HEPs were formed in HA-PEG(cRGD). (calcein, green), dead cells (ethidium homodimer-1, red), and nuclei (Hoechst 33 342, blue). (b) Z-stack of images obtained by confocal microscopy reveals the flat shape of hiPS-HEPS when cultured on a 2D substrate (left) compared to the 3D constructs of the cells in a HA-PEG(cRGD) hydrogel (right). The colours represent the height above the 3D cell culture device chamber bottom, i.e. the Z-axis, from 0 μm (red) to 40 μm (blue). (c) Albumin produced by hiPS-HEP on HEP Coat in 2D and in the different hydrogels. * indicates that the albumin concentration levels were too low for reliable quantification. Credit: Biofabrication, doi: https://doi.org/10.1088/1758-5090/aaf657 To meet these criteria, the scientists used a commercial 3D cell culture device (μ-Slide III 3D Perfusion IbiTreat) containing two consecutive chambers (2 x 30 µL) in three parallel arrays – each connected to media reservoirs to perfuse liquid. For effective perfusion, they mounted the device on an automatic rocking table by reversing the perfusate direction across the hydrogel-containing chambers. The experimental setup allowed perfusion through the device, fulfilling the first criteria. To fulfill the second criteria, the localized walls adjacent to the hydrogel chambers allowed the scientists to sample the perfusate without interfering the hydrogel or cell constituents. The scientists first investigated biofunctionalization of liver-on-a-chip devices in the study with HEPG2 cells (liver carcinoma cell line) encapsulated in hydrogels, after 3, 7 and 9 days of cell culture. They compared the cell morphology, viability and functionality with agarose and alginate hydrogels. The study included live/dead assays to confirm cell viability and further confirmed HepG2 functionality by detecting albumin and urea secretions in the supernatant of the cell culture. For improved cell functionality (surface attachment and mobility on materials), the scientists grafted cell adhesion motifs such as linear or cyclic RGD peptides (linear linRGD or cyclic cRGD) on to the hydrogels. In this instance, hiPS-HEP cells (hepatocyte stem cells) were cultured across different hydrogel compositions for 13 days to examine the morphology and viability (live/dead staining) after cell-material interactions. The scientists used six different hydrogel-based biomaterial surfaces in the experiments including; 2D (HEP coat), Agarose, Alginate, HA-PEG, HA-PEG (linRGD) and HA-PEG (cRGD). The hiPS-HEP cells encapsulated and cultured in the modified hydrogel grew within 2D and true 3D constructs. To test the functionality of the cultured hiPS-HEP cells (stem cells), the scientists quantified their albumin and urea excretion. The results showed that only the supernatants of stem cells cultured in 2D surfaces and in the presence of the cRGD motif hydrogels secreted albumin. Miniaturized bioreactors known as ‘organ-on-chips’, have recently emerged as alternative cell culture models that better mimic the in vivo biological microenvironment in the lab. The liver is a model of special interest in medical research due to drug hepatotoxicity observed at all phases of clinical drug development. Previous publications detail the use of organ-on-chips to predict the outcome of a drug’s impact in clinical trials and evaluate drug interactions with hepatocytes in the lab. © 2019 Science X Network In a recent study now published on Biofabrication, Jonas Christoffersson and colleagues demonstrated how hydrogels that mimic the extracellular matrix can support the functionality and viability of hepatocytes in a perfused liver-on-a-chip device. The interdisciplinary researchers in the division of biotechnology and molecular physics engineered a hydrogel system based on hyaluronan and poly(ethylene glycol) (HA-PEG) polymers. They developed the hydrogels using click chemistry. To enable the process, the scientists conducted a biorthogonal reaction (chemistry that occurs within living systems without the interference of native biochemical reactions) between a cyclooctyne moiety and alkyne azide-labelled reaction partner, known as strain-promoted alkyne azide cycloaddition (SPAAC).The new hydrogel materials were engineered and characterized in comparison with existing agarose and alginate hydrogels for cell compatibility (cytocompatibility). For biofunctionalization studies, the researchers used human induced-pluripotent stem cell derived hepatocytes (hiPS-HEPs). To improve surface cytocompatibility of the biomaterial, HA-PEG hydrogels were altered with azide-modified cell adhesion motifs to facilitate effective cell-material attachments. In the surface functionalized biomaterial, the hepatocyte stem cells migrated and grew in 3D orientations, with increased viability. The scientists observed higher albumin production on the novel material (characteristic liver protein), compared to cells cultured on other hydrogels. The flexible, SPAAC crosslinked hydrogel system with perfused 3D cell culture of hiPS-HEPs is a promising material to optimize liver-on-a-chip devices. 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

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Hydrogel based water purification system 12 times better than current systems

first_img Play Fabrication process of the h-LAH. Credit: Xingyi Zhou and Fei Zhao, UT Austin This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further The world needs an inexpensive way to extract drinkable water from dirty water. Every day, millions of people are forced to drink water that is unfit for human consumption. In many cases, the places that need the water the most are not included in large purification efforts, thus, personal systems are needed. The most common way to purify water in small amounts is to make and use a solar-based water distillation system in which a bottle painted black on the bottom is exposed to the sun. As the water evaporates, it collects on the upper exposed surfaces of the bottle and trickles down into a container. While this method works quite well as a means of extracting clean water, it is very inefficient as evaporation starts only when the bottle and its entire contents are heated. In this new effort, the researchers developed a vastly more efficient systems.The new work by the team was based on work they did last year. In that effort, they created a sponge-like material made from two hydrogels—one was water-binding, the other light absorbing. When the sponge was placed atop the dirty water in a solar still, it forced the water inside to evaporate faster than normally. This was due to the layer of water that was touching the sponge forging weaker hydrogen bonds. That effort pushed the efficiency of the solar still to 3.2 L/h/m2 of water—which, the researchers claim, was more than twice the theoretical limit. In this new effort, the researchers improved that efficiency even more by adding chitosan (another polymer) to the mix. Doing so allowed the sponge to hold more water, leading to faster evaporation. This pushed the efficiency of the solar still to 3.6 L/h/m2, which, the researchers claim, is 12 times better than commercial units. PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen A team of researchers from the University of Texas at Austin, collaborating with a group from the Lockheed Martin Corporation, has developed a new hydrogel-based water purification system—it is approximately 12 times better than existing commercial systems. In their paper published in the journal Science Advances, the group describes their system and how well it tested. PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Citation: Hydrogel based water purification system 12 times better than current systems (2019, July 1) retrieved 18 August 2019 from https://phys.org/news/2019-07-hydrogel-based-purification-current.html Solar-powered moisture harvester collects and cleans water from air Journal information: Science Advances © 2019 Science X Network Play Outdoor demo of the h-LAH based solar water purification. Credit: Xingyi Zhou and Fei Zhao, UT Austin More information: Xingyi Zhou et al. Architecting highly hydratable polymer networks to tune the water state for solar water purification, Science Advances (2019). DOI: 10.1126/sciadv.aaw5484last_img read more

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Usually unusual India

first_imgTina Chandroji’s oil on canvas paintings are like an arranged symphony. Garlands made of marigold, rose and jasmine, baskets full of petals and bouquets holding delicate stems, are all neatly arranged inside a flower shop. Chandroji’s painting looks so real that you can almost smell the scent of flowers. And that’s not all, her portrayal of Indian-ness in this most unusual way surfaces in the form of a bakery, music shop, vegetables and fruits shop, groceries’ shop, carpet shop, wine shop and even an office space. What connects all these paintings – apart from their stunningly real and meticulous depiction – is the presence of God in each work. Also Read – ‘Playing Jojo was emotionally exhausting’Mumbai-based Tina Chandroji, 34, believes that God is omnipresent and a part of every aspect of our lives and this is the thought behind her new body of works which will be exhibited in a show titled Cityscapes. Presented by Mumbai’s Art Space gallery, the show includes nineteen paintings in oil on canvas.Born in a Gujarati joint family of jewellers, Chandroji recalls that it was a childhood passion to paint that took her to JJ School of Art in 2001. ‘My mother is the religious one and I inherited the same from her,’ says Chandroji, ‘I have always been inspired by our cultural upbringing. Whether one lives in metros, villages or anywhere in the universe, one is in constant touch with God. My paintings connect us to the greatest gods of Indian culture. From roadside hawkers to offices of multinational companies, we are all connected to God.’ Also Read – Leslie doing new comedy special with NetflixHer ornately detailed works create an impact that only realism can. The work titled Antiques, for instance, is a delight to behold. Chandeliers and clocks, furniture and gramophone, artefacts and cabinets are so neatly arranged that every single element comes together to resemble a real shop. Or consider the work titled Vegetable Stall. Multi-coloured vegetables bunched together in artistic heaps, a transistor radio, photographs, hanging lamps, blue plastic bags hung on the wall – there is a photographic quality to each of her works. ‘As an Indian, you would have always seen shops like these,’ says Chandroji. ‘These are sights that I have grown up seeing in Mumbai, and these are present all over India. Religion and business is extremely intertwined. If you observe, you will see that every shop in India has a picture of God, another tradition, which is so unique to our culture,’ she says. ‘It’s common knowledge that bakeries are usually run by Christians or Parsis, grocery shops by West Indians, vegetable and fruits by North Indian and perfumes by Muslims and each of these places have a special place for their Gods.’.It is also like creating a film set. And that is what she did after completing her Bachelors in Fine Arts from JJ School of Art, Mumbai. She was the Assistant Art Director for the first season of Kaun Banega Crorepati and went on to become the Art Director for Salman Khan starrer Lucky- No Time For Love. With marriage in 2002 to art director and story board writer for Hindi and regional films, Chandroji was first initiated into the world of photography before she became a full-time artist. Her first solo show was at Lalit Kala Akademi, New Delhi in 2012.‘It takes me four to five months to complete a painting, though I work on three paintings at a time,’ she chuckles, as she recalls how viewers get so drawn to her work they want to touch and feel it!WHERE: Visual Arts Gallery, India Habitat CentreWHEN: 12 to 19 September, 10 am to 8 pmlast_img read more

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A wars homecoming

first_imgThrough mundane objects like matchboxes and utensils, rare monochromatic photographs of Indian soldiers cooking and a few silent movies depicting their life during the First World War an upcoming exhibition here will pay tribute to their unsung contribution during the Great War.The exhibition India and the First World War jointly organised by Roli Books, the French Embassy here and the Indira Gandhi National Centre for the Arts (IGNCA)will run from January 12 to February 10 to commemorate the 100th anniversary of the beginning of the War. Also Read – ‘Playing Jojo was emotionally exhausting’It wouldn’t be wrong to suggest that the exhibition is the brainchild of Roli Books publisher and CEO Pramod Kapoor, who first thought of thought of publishing a volume on the contribution of the Indian soldiers during the War when, at the Frankfurt Book Fair, several European exhibitors threw light on this lesser-known subject.After coming back he got in touch with Vedica Kant and Amarinder Singh, who researched and penned India and the First World War (prefaced with “If I die Here, who will remember me?” and Honour and Fidelity: India’s Military Contribution to the Great War 1914-1918. “That interaction with the exhibitors at the fair led to these two books because I realised these stories need to be told,” Kapoor told IANS. Also Read – Leslie doing new comedy special with NetflixBut what exactly shaped up this exhibition was a trip to Ypres and Lille in France, where he learned that Indian war heroes such as Khudadad Khan are household names and each family has a story to share about the warmth and bravery of the Indian troops stationed in this region. “It was so fascinating to see how many collectors had items used by the Indian soldiers while on the Western front. It was during the trip I realised the potential and gravity of this project,” said Kapoor. “I walked along the fields of Flanders where you can still pick out pieces of spent bullets embedded in the soil and was moved by the sight of the tricolour and Ashoka’s lion capital at Menin Gate,” he added. Kapoor then got in touch with the French Embassy, which made arrangements to bring the films and memorabilia to India for this exhibition. Apart from this, rare photographs of Indian soldiers will also be displayed.However, Kapoor hopes this exhibition reaches out to many people as books are read by aa few, but visual imaginary has the ability to reach out to many people. When: January 12 to February 10Where: IGNCAlast_img read more

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Council to announce HS results today

first_imgKolkata: The results of the Higher Secondary examination will be announced by the West Bengal Council of Higher Secondary Education (WBCHSE) on Friday. The results will be announced in a press conference which will be held at the office of the Council in Salt Lake at 10 am.Students can access their results from the officialwebsite of WBCHSE — wbresults.nic.in — from 11 am. The other websites through which the results can be accessed are www.indiaresults.com, www.exametc.com, www.schools9.com, www.jagranjosh.com etc. Students can also know their results by SMS option: WB12< Space> Roll number and send it to 58888.The marksheets would be distributed to the schools at 10.30 am. This year a total of 8,26,029 students appeared for the HS examination which was conducted from March 27 to April 11. The results are being published 58 days after the commencement of the examination. The HS Council has decided to introduce percentiles in the Class XII exam results this year to match boards like the CBSE.last_img read more

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With onset of monsoon KMC launches antilarvae drive

first_imgKolkata: The Kolkata Municipal Corporation (KMC) has launched a special anti-larvae drive at the onset of monsoon.The health department of KMC has urged people particularly the residents of highrises to ensure that no empty cups, broken furniture and other used materials are kept on the rooftop. Similarly, the authorities of schools and other educational institutions, central and state government offices have been asked to clear the roofs regularly. Also Read – Heavy rain hits traffic, flightsThe officer in charge of different police stations have been requested to ensure that there is no accumulation of water on the seized goods like vehicles that have met with road accidents, broken almirahs etc.Debashis Biswas, chief vector control officer said Dengue and malaria carrying mosquitoes take seven days to become adult. The accumulated water in empty plastic cups and containers, broken furniture serve as a potential breeding ground for the mosquitoes. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killed”To make the anti-larvae drive launched by KMC successful, cooperation of the residents is required. The civic authorities are conducting awareness programme throughout the year and people should come forward and take up the matter seriously,” said Debashis Biswas, Chief Vector Control Officer.There are 24 Rapid Action teams in KMC. The KMC health department workers are visiting individual houses and housing complexes to examine the overhead tanks and underground reservoirs. If it is found that the they are not covered properly, the owners in case of individual houses and secretary in case of housing cooperatives are asked to take up the issue immediately. If they fail to comply, then the KMC issue show cause notice.The civic authorities have decided that in buildings, where mosquito larvae will be found, the local councillors will be informed and will be requested to take the follow up action.Special stress has been given to remove garbage. Senior officials of all the departments meet on the third Thursday of every month to take a stock of the drives and video conference is held with the borough level officers.The meeting is presided over by the Municipal Commission Khalil Ahmed.There are 15 Dengue detection centres in the city and so far not a single Dengue case has been detected.last_img read more

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Drug case Name of bar dancer crops up

first_imgKolkata: Kolkata Police have come to know about the involvement of a bar dancer in the drug peddling racket in connection with which three youth were arrested on Thursday.Police have also got a few more names, who are involved in the drug peddling racket.The city police arrested three students of well known private colleges in the city on Thursday.All the three youth – Soumik Mukherjee, Mriganka Banerjee and Koustav Kar – are being remanded to police custody till July 11 after being produced before a city court on Thursday. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedPolice suspect that the youth often visited a bar off Eastern Metropolitan Bypass and they were in dire need of money.This need dragged them to the “dark world” of drug peddling and it was the bar dancer, who introduced them to a member of a racket, police suspect.Police have rigorously interrogated the three youth and the investigating officers have come to know about some more people, who are also involved in the racket.Sources said police are keeping a watch on the youth, whose names have come up in the investigation. Also Read – Naihati: 10 councillors return to TMC from BJPPolice are also maintaining vigil at the places where the arrested youth used to visit.It is learnt that police have gathered substantial information about the places, where the trio went for quite a number of times in the past two months.MDMA and LSD blots were recovered from the three youth, who were arrested on Thursday morning.Mriganka used to buy the same through the dark web. Police suspect that Mriganka is not the only youth, who was responsible for buying the drugs. Hence, police are trying to find out the person, who had actually dragged them into such activities. Police are probing into all possible angles to ascertain the entire network, through which the drugs reached the students and then got circulated amongst others.In a bid to uproot the menace completely, it is important to reach the root of the racket, police say.”Once the main person behind the entire operation is arrested, the flow of such drugs in the racket will get checked,” the officer said.It may be mentioned that in the recent times, the involvement of students in drug peddling rackets, has started coming to light.Hence, according to a section of police officers, it is essential to create awareness among students so that they do not get addicted to drugs or get involve in any such racket.Kolkata Police are also creating awareness among people against drugs through social networking sites. At the same time, police also organise campaigns every year.In another incident, Narcotics Control bureau arrested one Nurabul Khan from Narayanpur in Nadia on charges of smuggling narcotic substances. Around 95 Kg of ganja was seized from his house.last_img read more

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Rupee depreciation not always leads to export growth EEPC

first_imgKolkata: Contrary to popular belief that rupee depreciation helps exporters, currency volatility not always brings benefits for the fraternity, EEPC India said Monday. “Our view has been that it is a stable currency that helps exporters, providing them with predictability of dealing with the buyers. Any fluctuation and volatility on either side does not help,” EEPC India chairman Ravi Sehgal said in a release. Engineering Export Promotion Council of India (EEPC) said the country’s engineering export growth shrunk to single digit at 9.4 per cent in July, from sharp increases in the previous few months even as the rupee was depreciating against the US dollar during the month. It was a demonstration that a stronger dollar is not the only growth driver and does not always lead to export momentum, EEPC India said in an internal study recently. Also Read – Rain batters Kolkata, cripples normal life “Rupee depreciated more in July (6.56 per cent) as compared to June (5.19 per cent). But did exports grow at a higher rate and was there a currency depreciation advantage? No, exports in July this year expanded at a lesser pace of 9.37 per cent than 14.17 per cent in June. The dollar appreciation, conversely, is also making the raw material for exports expensive,” EEPC officials said. The rupee strengthened by 23 paise in early trade Monday to 70.77 against the US dollar. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed EEPC officials said the key lies in improving the domestic efficiency levels so that the cost of production is brought down. Engineering exports had grown by 18.92 per cent in April, 2018, 14.59 per cent in May, 14.17 per cent in June and 9.37 per cent in July, a release said. EEPC pointed out that the best thing in the interest of exporters is a stable currency. In any case, the present depreciation of rtupee should get a contextual perspective that it is not the Indian currency alone which has lost ground against the US dollar.last_img read more

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Dental hospital gets world class auditorium

first_imgKolkata: In a major infrastructure revamp, the Dr R Ahmed Dental College and Hospital has received a newly renovated world class auditorium, a digital classroom, a toilet complex equipped with modern technology and an OPD token system.Apart from these new facilities a new ‘implant clinic’ was also inaugurated at the hospital for the better treatment of the patients. A huge number of patients from various parts of the state visit the hospital, which is one of the oldest dental hospitals in Asia. Also Read – Bose & Gandhi: More similar than apart, says Sugata BoseTrinamool Congress MP Sudip Bandopadhyay, who is also the Rogi Kalayan Samiti Chairman of the hospital, laid the foundation stone for setting up a guest house for the doctors. Minister of state for health Chandrima Bhattacharya, Dr Nirmal Majhi, minister of state for Labour department and the Member of Parliament Dr Santanu Sen also graced the occasion. Various departments, including Pedodontia and Orthodontia, have been given a major facelift in terms of enhancing infrastructure. This will immensely benefit the patients as they would be able to avail better health services. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: Mamata”Ankur”, an annual wall magazine of Dr R Ahmed Dental College and Hospital was also released by the delegates. Some of the senior health department officials were also present at the programme. It was learnt from the hospital sources that the newly published magazine focuses on Indian Army and their contribution, valour and sacrifices. The magazine was inaugurated by Dr Maji in presence of Dr Pradip Mitra, director of Medical Education and Principal of the Dr R Ahmed Dental College and Hospital Dr. T.K Giri. A moment of silence was observed during the inauguration to pay tributes to the martyrs of Pulwama terror attack. Dr Raju Biswas, member of Rogi Kalayan Samity at the hospital, said: “As many as 38 newly equipped dental chairs have been installed at orthodontia and pedodontia departments. The automated token vending machine along with a digital display has been set up inside the hospital complex to prevent unnecessary queues.” Dr Tapan Kumar Giri, the principal of Dr R Ahmed Dental College and Hospital, said: “The oldest institute of South East Asia has always been a pioneer in serving best dental treatment not only to the patients from the state but from outside as well. We are thankful to our Chief Minister Mamata Banerjee for various initiatives at the hospital.”last_img read more

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Recertification of disabled students by board unlawful

first_imgKolkata: Many of the disabled candidates seeking admission in medical colleges undergo ‘reassessment or re-certification’ by the Disability Assessment Board before taking part in the counseling, which is a gross violation of norms set by the Rights of Persons with Disabilities Act, 2016.The Act says that none can alter the level of disability in a patient others than Centre-designated hospitals. It has been alleged that during the ‘reassessment’ the Disability Assessment Board is altering the level of the disability in people and also issuing a certificate. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataAs a result of this the physically-challenged medical aspirants have been denied admission. Many hospitals across the state are assigned by the government to issue disability certificate to the candidates after a thorough check up. No organisations or bodies can issue another certificate overturning the previous one. Various government hospitals have the right to issue the certificate for a certain period of time in the completion of which the candidates need to turn up before the medical board of the hospitals for a re-certification. A city-based doctor said that the Madras High Court in an earlier case called the ‘reassessment’ as unconstitutional. Also Read – Lightning kills 8, injures 16 in stateMany of the disabled candidates from Bengal have alleged that they were often harassed during the ‘reassessment’ by the Disability Assessment Board. In many cases, the level of deformity in the candidates has been altered resulting in a failure to secure a seat in medical colleges. Jane Alam, a medical student in the state with a physical deformity, said: “It is an unlawful practice and the candidates with physical problems have to travel to other states as there are only four such centres in India. The ‘reassessment’ often has a psychological impact on the candidates as the candidates are harassed. I had been subjected to harassment when I turned up before the Disability Assessment Board.” There are such centres in Kolkata, Chennai, Mumbai and Delhi. Candidates from the other states despite their challenges have to visit any of the four centres to get their deformity level tested. Sushanta Pramanik from the East Midnapore district recently wrote to the NITI Aayog and also the Medical Council of India to draw their attention in this regard. The letters says that no power is given to the MCI or any authority to re-issue a new certificate of disability. The Disability Assessment Board authority alters the percentage of disability, sometimes by decreasing and sometimes by increasing the percentage. There is no provision of re-evaluation/re-assessment of Disability Certificate. The letter also states that all certificates such as SC, ST, OBC and PWD etc are available online and verification can be done by clicking a mouse within seconds.last_img read more

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Social media may improve mental health

first_imgContrary to popular belief, using social media and the internet regularly could improve mental health among adults and help fend off serious psychological distress, such as depression and anxiety, a study has found. According to researchers from Michigan State University in the US, communication technologies and social media platforms make it easier to maintain relationships and access health information. Until now, adults have not been the focus of much research on the mental health impacts of social media use, said Keith Hampton, a professor at Michigan State University. Also Read – Add new books to your shelfMost studies on social media have focused on youth and college students, and the effects could be explained by life stages, rather than technology use. “Taking a snapshot of the anxiety felt by young people today and concluding that a whole generation is at risk because of social media ignores more noteworthy social changes, such as the lingering effects of the Great Recession, the rise in single child families, older and more protective parents, more kids going to college and rising student debt,” Hampton said. Also Read – Over 2 hours screen time daily will make your kids impulsiveResearchers set out to study more mature populations, analysing data from more than 13,000 relationships from adult participants. Using 2015 and 2016 data, the team found social media users are 63 per cent less likely to experience serious psychological distress from one year to the next, including major depression or serious anxiety. Having extended family members on social media further reduced psychological distress, so long as their family member’s mental health was not in decline. The study, published in the Journal of Computer Mediated-Communication, challenges the notion that social media, mobile technologies and the internet contribute to a mental health crisis. The researchers found that someone who uses a social networking site is 1.63 times more likely to avoid serious psychological distress. The extent to which communication technologies affect psychological distress varies according to the type and amount of technologies people and their extended family members use. Changes to the mental health of family members affect the psychological distress experienced by other family, but only if both family members are connected on a social networking site. “Today, we have these ongoing, little bits of information popping up on our cell phones and Facebook feeds, and that ongoing contact might matter for things like mental health,” Hampton said.last_img read more

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Sylvester Stallone Turned Down an Enormous Sum so That he Could Star

first_imgRocky Balboa is a cultural hero, an icon representing the underdog beating the odds and succeeding in following his dreams. His story initially tells of the long shot fight against the “Master of Disaster” boxing star Apollo Creed. Rocky loses by a decision in his first bout but ultimately wins thanks to his unrelenting passion and manages to turn from “nobody” into “somebody”.The original movie won three Oscars out of nine nominations and made 200 million dollars at the box office.As amazing as this movie is, the story behind making it is truly inspiring.Sylvester Stallone as Rocky Balboa and Talia Shire as Adrian in Rocky. (Photo by John Springer Collection/CORBIS/Corbis via Getty Images)Sylvester Stallone did not have it all throughout his life. His unique way of speaking and look to his face were a result of complications at birth that caused him nerve damage.He did not grow up in a stable family environment, with his parents fighting much of the time. Stallone and his brother Frank were therefore put into foster care.Before starting high school, the brothers came back to their home in Philadelphia. However, Stallone’s unstable childhood had left a strong mark on his psychological well-being.Stallone at the Ken Norton / Duane Bobick boxing match in 1977.He continued to struggle with school work and got expelled from different schools.During his teenage years, he discovered his passion for art which served to express things he was going through on the inside.He decided he wanted to try himself out as an actor at 18 years old. He had studied drama but did not follow through with it.Sylvester Stallone in 1988 in Sweden for Rambo III. Photo by Towpilot CC BY-SA 3.0After giving up on his academic pursuits he moved to New York to follow his dream of becoming a professional actor.Things still did not seem to pan out right for him from the beginning. He had to work multiple jobs to sustain himself and his wife.At some point due to his ongoing financial struggles, he took on a role in an adult film.Stallone with Brigitte Nielsen, Ronald Reagan and Nancy Reagan at the White House, 1985By the end of his 20s, the unknown actor craved something bigger, something significant that would finally help him make his dreams come true.According to Forbes, Stallone explained: “And then one night, I went out to see Muhammad Ali fight Chuck Wepner. And what I saw was pretty extraordinary. I saw a man called ‘The Bayonne Bleeder’ fight the greatest fighter who ever lived. And for one brief moment, this supposed stumblebum turned out to be magnificent. And he lasted and knocked the champ down. I thought if this isn’t a metaphor for life.”Actor Sylvester Stallone in Rocky Balboa.After witnessing the match Stallone started working on his own script about Rocky, that proved to be a materialization of Stallone’s own path in life. He finished the script of 90 pages in an astonishing three days.Rocky Balboa Statue in Philadelphia. Sylvester Stallone donated the bronze monument to the city.Sometime later, Stallone went to a casting call for a movie for which he was once again not a good fit as people were usually keen to hire already established names.However, on the way out he pitched his screenplay to the producers that agreed to read it.They loved his idea but did not want to have him as the lead role, so they instead offered him $360,000 for the script. An enormous sum in those days.Stallone signing autographs during the filming of Rocky Balboa.In his situation of utter financial insecurity, this offer was more than appealing. However, Stallone did not yield and decided to not settle on anything less than a lead role, no matter the money.The producers finally relented but decided to finance the movie only with 1 million dollars, a meager amount even at the time. But it allowed Stallone to act as Rocky.Rocky statueThe movie was shot fast, filming most of the footage in one takes in order to save film rolls. Stallone’s wife worked as a set photographer and extras worked for fried chicken.Take a closer look with this video:Gabe Sumner was working as a marketing specialist on the movie. He constructed the whole marketing strategy exactly around the similarities of the life paths of Rocky Balboa and Sylvester Stallone. While doing this he exaggerated many aspects so that people could more readily identify with the real underdog success story.Read another story from us: Muhammad Ali’s Greatest Trash Talking MomentsHowever, even when people found out about this nobody really cared. Rocky was already a cultural hero and Sylvester’s struggle to bring him to the silver screen on his own terms is what gave the movie its heart and soul. Rocky is here to stay with us, as evidenced by his boxing shorts now residing in the Smithsonian, and a bronze statue of him near Philadelphia’s iconic Museum of Art, where Rocky threw up his arms in triumph.last_img read more

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Rudolph Valentino – The Latin Lover who Became Americas First Male Sex

first_imgRudolph Valentino was a Hollywood actor during the 1920s who died at the age of 31. His status as perhaps the first mass market sex symbol and his premature death turned Valentino into a legend. His funeral generated mass hysteria, with over 100,000 people crowding the streets of New York City. Many women fainted while some reportedly committed suicide.The truth is, Valentino had only a few years to enjoy the life of fame and fortune. He spent most of his years broke, or with very little money, unsuccessful and struggling to rise as an actor.Rudolph ValentinoBorn in 1895, in Castellaneta, Italy, Valentino was a very charming, beautiful, and playful boy who frequently failed at school. In the end, he somehow managed to earn a certificate from the agricultural school in Genoa.Then he tried his luck moving to Paris where he took dance lessons. However, it was hard for him to find a job — or to keep one — and he soon moved back to Italy, broke.Rudolph Valentino as a boyIn 1913, at the age of 18, Valentino moved to the United States. His fortune didn’t change upon his arrival in New York; he soon ran out of money and was forced to spend some time on the streets of the Big Apple.Unable to find stable employment and aspiring to become an actor, Valentino took on very obscure and often underpaid jobs to survive. His looks and talent for dancing often brought him jobs synonymous with a gigolo, according to many people.Rudolph Valentino in Motion Picture Studio Directory and Trade Annual, 1918.Once he even worked as a taxi dancer: customers hired him to dance in taxi-dance halls, something which was very popular in America during the early 20th century.His ambition to become an actor led him to Los Angeles where he tirelessly enrolled for auditions for screen roles. But his looks and accent were everything that wasn’t American, and as such, Valentino was often cast as a villain. He wasn’t happy with the roles he was picked for, even less with his success, and moved back to New York.Rudolph ValentinoThere, while staying with some friends in Greenwich Village, he met the French cinematographer Paul Ivano, and his life was suddenly turned around.In 1920, Rudolph Valentino landed a role in The Four Horsemen of the Apocalypse which was released in 1921 and became the first film to make $1 million at the box office. To this day, it remains the sixth-highest grossing silent movie ever made.Rudolph ValentinoHe became known as the “Latin lover,” and women found him irresistible. He was an objectification of sensuality, sex, and even love — not only on screen but also in magazines. And while women adored him, men tended to be at least a little jealous of his status.Dick Dorgan, a famous American cartoonist and writer in the early 20th century, once jokingly said in Photoplay: “I hate Valentino! All men hate Valentino…The men have formed a secret order to loathe, hate, and despise him for obvious reasons.”Rudolph Valentino in the Blue Book of the ScreenOnly five years into his life of fame, on August 15, 1926, Valentino collapsed at a hotel in NYC. He was hospitalized and taken for immediate surgery after suffering from inflammation of the appendix and gastric ulcers.His condition didn’t improve after the surgery. Although he was conscious and chatted with the doctors, they realized that Valentino was dying. He passed away on August 23rd.Grave of Rudolph Valentino.When the sad news reached the public, over 100,000 people took to the streets for the funeral service. Everyone crowded for their turn to lay eyes on Valentino’s body, displayed at Saint Malachy’s Roman Catholic Church.There was a lot of dramatic hysteria, fainting, and smashing the church’s windows to reach inside. Valentino’s fiancé, Pola Negri, collapsed and there were several reports of women committing suicide because of his death.Read another story from us: The Embarrassing Demise of Elvis – Factors which Led to that Fateful ToiletOver 100 police officers were deployed to restore order. There was a second funeral service on the West Coast, and Valentino was buried at Hollywood Forever Cemetery.last_img read more

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Dark and Twisted – These Ancient Mysterious Trees are Older than the

first_imgThe yew, that dark, twisted, enigmatic tree of legend, looms over churchyards across Europe. Yew trees are a common sight, especially in the United Kingdom, yet few people realize just how old many of these great beings really are. Thought to be the oldest tree in Europe, the yew that stands in the churchyard of St. Cynog’s in Powys, Wales, may be over 5,000 years old. According to the Woodland Trust, it’s in good company – there are over 250 yew trees in the United Kingdom that are classified as “ancient”, meaning that they have been growing for over 900 years.An ancient Yew tree next to a churchyard in an English villageYew trees are notoriously difficult to date accurately, and so in 2014 the yew at St. Cynog’s was subjected to a number of different tests, including DNA analysis and ring counting. Janis Fry, an expert in tree aging, is confident that the tree is the oldest non-clonal tree in Europe, according to The Express. The tests, conducted by the Forestry Institute, concluded that the tree had a ring count of 120 per inch, which would make it around 5,000 years old.St Cynog, Defynnog. © Philip Pankhurst cc-by-sa/2.0The oldest non-clonal tree in the world, according to official records, is a bristlecone pine in southern California, which has been accurately dated to 5,068 years old. However, it is very difficult to precisely date yew trees, and there are a number of candidates, including the St. Cynog Yew, that may rival even this ancient being.Until 2014, it was thought that the oldest tree in Europe was the Fortingall Yew, in Perthshire, Scotland, which has been roughly dated to between 3,000 and 5,000 years of age. However, according to The Woodland Trust, the St. Cynog Yew may be even older.One trunk of the Fortingall yew. Photo by Mogens Engelund CC BY-SA 3.0Part of the difficulty in dating yew trees is due to the fact that, with age, the central trunk often splits into two or several main stems, thus preventing accurate dating using the heartwood rings.This is the case with both the St. Cynog Yew and the Fortingall Yew, which both have fractured trunks. Nevertheless, the trees are otherwise in excellent health and could live for centuries to come.In addition to their broken, decayed appearance, ancient yew trees in the United Kingdom bear the marks of history. According to The Woodland Trust, a cannonball was found inside the trunk of the Crowhurst Yew in Surrey, England, which is thought to have become lodged there at the time of the English Civil War (1642–1651).The split trunk section of the Llangernyw Yew. Photo by Emgaol CC BY-SA 3.0Indeed, if the dating of the St. Cynog Yew is correct, it would have been little more than a sapling at the time of the construction of Stonehenge, and already centuries old when the Great Pyramid of Giza was raised up from the desert. By the time the Romans set foot in Britain, it was already thousands of years old.Related Video: 6 World Famous Land Marks Hiding Something From The PublicYew trees are found in churchyards all over the United Kingdom, in part because of their ancient mythological significance. They carry strong associations with death and resurrection, and often feature in Celtic and Greek traditions as symbols of decay and regeneration.Ancient Yew tree in a churchyardThis may be due to their evergreen foliage and exceptionally long lives, in addition to their perceived regenerative powers. Yew trees appear to suffer extreme damage and decay, splitting open at the trunk, yet they continue to thrive.Even before the advent of Christianity, they were planted in spiritually significant locations and used as part of pagan rituals, often involving death and sacrifice. Later, the ancient traditions surrounding yew trees would become merged with Christian practice, and they were incorporated into Lenten and Easter celebrations, symbolizing the death and resurrection of Christ.Yew trees at Kingley Vale in the South Downs National Park in England are some of the oldest yew trees in the world. They are between 500 and 2,000 years old.For similar reasons, they were often planted in churchyards, watching over the dead and ensuring their spiritual resurrection.Read another story from us: 400-yr-old Bonsai Stolen in Japan – Owners Hope the Tree is WateredThe twisted, tortured trunks of these ancient trees now stand watch over churchyards and graveyards all over Europe, and with luck, will continue to do so for many centuries to come.last_img read more

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Steve McQueen the Subject of Fierce Lawsuit Between his Son and Famed

first_imgChadwick McQueen, the son of movie legend Steve McQueen, is suing luxury designer Tom Ford over McQueen’s name on several expensive cardigans being sold. “Steve McQueen made cardigans cool,” says the Hollywood Reporter. “Chadwick McQueen controls his father’s rights of publicity and trademark rights, along with City National Bank, and claims Tom Ford’s line of ‘McQueen’ sweaters are infringing them.”Born in 1960, Chadwick McQueen is the son of McQueen and his first wife, Neile Adams.Tom Ford. Photo by nicolas genin CC BY-SA 2.0“Certain sartorial items in fact became synonymous with McQueen,” writes attorney Keith Wesley in the complaint, according to the magazine. “One such garment was a wool cardigan sweater with a shawl collar. … McQueen made that sweater cool — so much so that James Bond wore one forty years later.”Tom Ford is selling a “McQueen Cardigan” for $2,390 and a “Merino McQueen Cardigan” for $1,690 through its website, according to the complaint. Neiman Marcus is selling Ford’s line and uses the actor’s full name in the item monikers. Bergdorf Goodman describes them as “inspired by the iconic Steve McQueen.”Steve McQueen as Frank Bullitt next to a Ford Mustang 390 GT 2+2 Fastback in the thriller movie ‘Bullitt’, San Francisco, 1968. Photo by Silver Screen Collection/Getty ImagesSteve McQueen was one of the highest paid actors in Hollywood, with his most successful films including The Magnificent Seven, Bullitt, and The Great Escape. When he died of cancer in 1980, he was in debt. However, his image today as a cool, tough, sexy anti-hero far outshines most other actors popular in the 1960s and 1970s.As The Fashion Law put it, “The estate of Steve McQueen is far from flattered that $1,600-plus cardigans from Tom Ford bear the ‘McQueen’ name and has slapped the fashion brand with a trademark infringement, right of publicity violation, and unfair competition lawsuit, as a result, seeking to immediately and permanently prevent any further usage of the late actor’s name and an array of monetary damages, including all of the profits that Tom Ford made from its sale of the sweaters, plus statutory damages of at least $2 million.”Las Vegas, USA – September 7, 2012: Tom Ford storefront sign at the Crystals shopping center in CityCenter on Las Vegas strip. The Crystals is a luxury shopping, dining and entertainment center.By selling the sweater with the McQueen name attached to it, Tom Ford could cause confusion among consumers as to whether the McQueen estate is connected with or has authorized such usage (the core of a trademark infringement claim), according to the estate.Related Video: Things you may not know about Steve McQueenAccording to the Hollywood Reporter, “Chadwick is seeking disgorgement of all profits plus at least $2 million in statutory damages for each registered trademark and punitive damages — plus an injunction barring the companies from using his trademark, name, persona or likeness or implying an association with the family and an order that all marketing and promotional materials bearing McQueen’s name or likeness be destroyed.”Photo of Steve McQueen as Josh Randall from an episode of the television program ‘Wanted:Dead or Alive,’ August 21, 1959McQueen was nominated for an Academy Award for The Sand Pebbles and nominated for Golden Globes for four films, including Papillon, but he never won a major acting award despite his box-office stature and his insistence on pushing himself to the limits in his films.McQueen was rebellious his entire life, competitive with other actors, and challenging to his directors. He gave Yul Brynner a hard time throughout the shooting of The Magnificent Seven and considered Paul Newman his chief rival. McQueen passed on Butch Cassidy and the Sundance Kid because he and Newman couldn’t agree on who would receive top billing.McQueen’s mug shot booking photographs for DWI in Alaska (1972, age 42)He divorced his first wife to marry his co-star on The Getaway, Ali McGraw. That marriage ended in divorce as well. Steve McQueen was passionate about motorcycles and race cars, and his clothing choices often reflected those interests.Read another story from us: Frank Zappa Going on Tour Again…as a Hologram!One fashion site explained it thus: “Steve McQueen made everything he wore cool. Whether it was a polo shirt and khakis or a lounge suit, everything he wore looked better.”Nancy Bilyeau, a former staff editor at Entertainment Weekly, Rolling Stone, and InStyle, has written a trilogy of historical thrillers set in the Tudor era for Touchstone Books. Her new book, The Blue, is a spy story set in the 18th-century porcelain world. For more information, go to www.nancybilyeau.comlast_img read more

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