The scientists, Alexander Kendl and Joseph Peer from the University of Innsbruck, analyzed electromagnetic pulses of repetitive lightning discharges and compared them to the magnetic fields used in clinical transcranial magnetic stimulation (TMS). Their results suggest the variable magnetic fields produced by lightning are in the same order of magnitude and frequency as those applied in TMS that stimulate hallucinations, such as balls of light known as cranial phosphenes. They postulate that balls of light known as ball lightning, which are occasionally reported during thunder and lightning storms, could often be hallucinations arising from lightning electromagnetic pulses affecting the brains of close observers.Ball lightning was first reported in St. Petersburg in Russia in 1754 by a Dr. Richmann, who was attempting to copy Benjamin Franklin’s kite-lightning experiment, and who was instantly killed by the lightning. It is rarely seen and photographic evidence is almost nonexistent. There are dozens of theories of how ball lightning could form, including the burning of hot silicon particles produced when a lightning strike vaporizes the ground.TMS is a non-invasive method of stimulating areas of the brain, and is used in psychiatric treatments and in studying the brain. It is known that when the visual cortex is stimulated by pulsed magnetic fields in TMS, patients will sometimes see hallucinations of luminous shapes in their visual field. With the stimulation coils attached to the head, the visions can occur with single or repeated pulses at frequencies of around 1-50 Hz. The cortical phosphenes appear as bubbles, lines, ovals or patches of either white or a variety of colors. When the stimulation coil is moved, the phosphenes also appear to move. Rare but natural long (1-2 seconds) repetitive lightning strikes produce electromagnetic pulses, which the researchers thought might produce currents within the brain in the same order of magnitude in terms of duration, strength and frequency as in TMS in observers 20-100 meters away from the lightning strike. They calculated the time-varying electromagnetic fields of various types of lightning strikes for observers at various distances from the strike.The calculations showed that only lightning strikes consisting of multiple return strokes at the same point over a period of seconds could produce a magnetic field long enough to cause cortical phosphenes. This type would account for around 1-5% of lightning strikes, but very few of these would be seen by an observer 20 to 100 m away, and of those the researchers estimate seeing the light for seconds would occur only in about one percent of unharmed observers. The observer does not need to be outside, but could be inside an aircraft or building. Kendl and Peer also said an observer would be most likely to classify the experience as ball lightning because of preconceptions. Citation: Ball lightning may sometimes be explained as hallucinations (2010, May 13) retrieved 18 August 2019 from https://phys.org/news/2010-05-ball-lightning-hallucinations.html A New Kind Of Lightning Discovered Electric field transcranially induced at various observation points (from bottom to top: 20 – 100m distance from strike point) by the time derivative of the lightning magnetic field during the decline phase of an average negative cloud-to-ground subsequent return stroke. Phosphene perception can be expected for induced fields above 20 V/m. Long duration repetitive stimulation of phosphenes up to seconds can be caused by higher multiplicity strokes. See arXiv:1005.1153v1 paper for details. (PhysOrg.com) — Physicists in Austria have calculated the magnetic fields associated with certain types of lightning strikes are powerful enough to create hallucinations of hovering balls of light in nearby observers, and that these visions would be interpreted as ball lightning. © 2010 PhysOrg.com Explore further More information: J. Peer, A. Kendl: Transcranial stimulability of phosphenes by long lightning electromagnetic pulses, arXiv:1005.1153v1 [physics.med-ph] arxiv.org/abs/1005.1153 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.
Two years ago, Japanese researchers Kei Kurotobi and Yasujiro Murata figured out a way to imbed a water molecule in a 60-atom fullerene (buckeyball)—they slit it open, inserted a single water molecule, then sealed it back up again, effectively trapping the water molecule inside—they called it [email protected] In this new effort, the researchers created a computer simulation which they claim shows what would happen if such a molecule were placed inside a nanotube and subjected to an electrical charge. Their efforts show, they say, that it would cause the fullerene (and water molecule) to move, in this case through a channel.David Lindley, in an article for the American Physical Society site Physics, says that the simulation the two researchers created takes into account all of the known properties of [email protected] and notes that the simulation treats the molecule as a single entity.After embedding the water molecule inside the fullerene, the researchers simulated putting the new structure inside of a carbon nanotube, essentially creating a channel to allow for movement of the fullerene along with its water molecule cargo. They then applied an electrical charge parallel to the nanotube. Doing so, the researchers found, caused the fullerene to move within the channel (and the water molecule inside to spin), carrying its cargo with it. Normally, applying an electrical charge to water molecules does not cause them to move (because they are neutrally charged)—instead a thermal driven motion known as libration occurs.In the simulation however, embedding a water molecule in a fullerene allows it to be driven through a channel using electric current, opening up the possibility of creating fullerenes that carry other chemicals through nanotubes—a process that could prove useful for applications such as delivering therapeutic drugs to ailing body parts, for example.Interestingly, the researchers found that if the charge was increased to 0.065 volts per angstrom, the direction of movement in the channel was reversed, though they can’t explain why. 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. (Phys.org) —Researchers Baoxing Xu and Xi Chen, working at Columbia University, have created a computer simulation that shows it’s possible to manipulate the movement of a 60-atom fullerene, with a water molecule trapped inside of it, using an electrical charge. They describe their simulation and results in their paper published in Physical Review Letters. A water molecule bestows electric polarity on the fullerene sphere that surrounds it, allowing the structure to be guided by an electric field, even though it remains electrically neutral. Credit: Physics Focus / F. L. Bowles/Univ. of California, Davis Scientists build world’s smallest ‘water bottle’ Explore further © 2013 Phys.org Citation: Simulation shows it’s possible to move [email protected] using electrical charge (2013, April 22) retrieved 18 August 2019 from https://phys.org/news/2013-04-simulation-h2oc60-electrical.html More information: Electrical-Driven Transport of Endohedral Fullerene Encapsulating a Single Water Molecule, Phys. Rev. Lett. 110, 156103 (2013) prl.aps.org/abstract/PRL/v110/i15/e156103AbstractEncapsulating a single water molecule inside an endohedral fullerene provides an opportunity for manipulating the [email protected] through the encapsulated polar H2O molecule. Using molecular dynamic simulations, we propose a strategy of electrical-driven transport of [email protected] inside a channel, underpinned by the unique behavior of a water molecule free from a hydrogen-bonding environment. When an external electrical field is applied along the channel’s axial direction, steady-state transport of [email protected] can be reached. The transport direction and rate depend on the applied electrical intensity as well as the polar orientation of the encapsulated H2O molecule. Journal information: Physical Review Letters
(Phys.org) —The cytoskeletal proteins of eukaryotes polymerize into self-organized patterns even as pure solutions. However, to see more complex dynamics, like filament sliding or rotation, various motor proteins and cofactors usually need to be added to the solution. The ancestral bacterial proteins of actin and tubulin, namely FtsA and FtsZ, play a key role in bacterial cell division through the formation of a cytoskeletal structure known as the “Z” ring. Researchers Martin Loose and Tim Mitchison have studied these bacterial proteins in solution, along with bits of reconstituted membrane, and found that they support complex dynamics in the absence of any motor proteins. In their recent paper in Nature Cell Biology, they describe how these behaviors can spontaneously emerge. Cytoskeletal Ring Formation. Credit: labs.cellbio.duke.edu More information: The bacterial cell division proteins FtsA and FtsZ self-organize into dynamic cytoskeletal patterns, Nature Cell Biology (2013) DOI: 10.1038/ncb2885AbstractBacterial cytokinesis is commonly initiated by the Z-ring, a cytoskeletal structure that assembles at the site of division. Its primary component is FtsZ, a tubulin superfamily GTPase, which is recruited to the membrane by the actin-related protein FtsA. Both proteins are required for the formation of the Z-ring, but if and how they influence each other’s assembly dynamics is not known. Here, we reconstituted FtsA-dependent recruitment of FtsZ polymers to supported membranes, where both proteins self-organize into complex patterns, such as fast-moving filament bundles and chirally rotating rings. Using fluorescence microscopy and biochemical perturbations, we found that these large-scale rearrangements of FtsZ emerge from its polymerization dynamics and a dual, antagonistic role of FtsA: recruitment of FtsZ filaments to the membrane and negative regulation of FtsZ organization. Our findings provide a model for the initial steps of bacterial cell division and illustrate how dynamic polymers can self-organize into large-scale structures. Citation: The dynamic cytoskeleton in bacterial cell division (2013, December 10) retrieved 18 August 2019 from https://phys.org/news/2013-12-dynamic-cytoskeleton-bacterial-cell-division.html Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. The researchers studied a lipid bilayer preparation in which FtsA protein was readily attached through a special helix found at its carboxy terminus. When GTP was added, they found that the FtsZ was recruited to the membrane region, and was rapidly polymerized. After a critical density was reached, motile streams were seen moving in a single predominate direction, with complex rotating vortices found between them. The structures would persist for tens of minutes and rotated at speed of up to 11 degrees per second. While their system did not have all the components normally found in bacterial cells, the researchers noted that the vortices were reminiscent of the helical patterns seen during Z-ring assembly in E.coli and Bacillus subtilis. The formation of the patterns required the addition of ATP. The researchers found that no ATPase activity was present, and subsitution with ADP worked just as well. On the other hand, GTP was found to be hydrolyzed in the process, and only static filament bundles were formed when it was prevented.The researchers observed that the swirls had a preferred directionality. They explained this chirality as a result of polar molecules attaching to a single face of the bilayer, combined with the effects of bundling and treadmilling in curved FtsZ filaments. They also note that the attachment of enzymes to the Z-ring could occur in a spatially organized fashion with the predominate force for inward growth in cell division arising from bond formation during cell wall biosynthesis.The larger question of asymmetry in cells often escapes everyday notice. Neurons, in particular, are highly polarized with the axon defining a principle direction. Yet very little in terms of neuronal function has been ascribed to any particular handedness. As mentioned previously, one issue which might be further explored in this vein would be orientation specific effects felt beyond the immediate cell, like the direction of glial wrapping, for example. Other possible effects like rotation of free microtubules as a result of the directed transport of various cargo have scarcely been studied, but could have interesting implications for the organization of cells. Simulation, like one recent model exploring the role of the GTP cap region in microtubule dynamics, will be an important compliment to these kinds of in-vitro experiments. The study of the intrinsic pattern formation capability of more primitive cytoskeletal proteins will lead to greater understanding of the functions of their diverse, and uniquely optimized descendants found today in eukaryotic cells. Journal information: Nature Cell Biology Scientists deconstruct process of bacterial division © 2013 Phys.org
Journal information: Proceedings of the National Academy of Sciences (Phys.org)—The Earth’s oceanic system isn’t just the big, blue puddle of water that globes suggest; its waters are stirred by a vast system called thermohaline circulation, a process driven by varying water densities, heat, and the interactions of freshwater and salt water. Thermohaline circulation moves energy and matter around the globe and drives the planet’s climate, but it also responds to changing climate conditions. For example, one such oceanic conveyor is the Atlantic Meridional Overturning Circulation (AMOC-IV), which drives warm water poleward from the equator, cooling toward the North, and sinking as it becomes more dense at high latitudes. This cold, dense water then empties into ocean basins before upwelling in in the Antarctic.Its interdecadal variability, measured by the oscillation of its period and amplitude, modulates climate changes worldwide. However, it’s unclear how global warming affects AMOC-IV, and an international collaborative of researchers has now investigated the effects of climate change on AMOC-IV amplitude and time scale.The researchers conducted an analysis of 19 experiments from five models of the Coupled Model Intercomparison Project Phase 5 simulations; each experiment had one preindustrial control simulation and four future warming scenarios. Under all future global warming scenarios, AMOC transport is reduced by 5 percent to 48 percent, depending on the scenario. “In response to future global warming, AMOC-IV shows a robust change, with its major period shortened and its amplitude reduced,” the authors write.They note that the reduced amplitude of AMOC is consistent with other modeling studies. The mechanism of its changes under global warming remains unclear, however, due to the challenging complexities and interactions of global oceanic circulation. As one candidate for such a mechanism, they cite baroclinic Rossby waves. These are huge, slow waves in the troposphere generated by temperature differences of the oceans and continents. “With global warming, oceanic stratification is projected to be enhanced over the globe owing to a weaker warming with depth, and the stratification enhancement is more robust in a stronger warming scenario,” they write. “A stronger stratification should lead to faster baroclinic Rossby waves and, potentially, a shorter period of AMOC-IV.”Even continental regions situated far from the coasts are strongly influenced by ocean currents. Since most of the sun’s radiation is absorbed by the ocean, the movement of this energy in the Gulf Stream and other currents serves to modulate weather; through evaporation, heat from the ocean is exchanged with the air. A failure of the conveyance of heat away from warm regions and toward cooler regions stands to throw the climate further out of balance. Thus, research into climate change-related disruptions of oceanic conveyors is important as CO2 and methane contribute to atmospheric heat retention.The authors conclude, “Our study suggests that AMOC-IV may be significantly weakened in amplitude and shortened in period under future global warming, and that these responses could be caused by strengthened ocean stratification and, in turn, the speedup of baroclinic Rossby waves.” 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. Could ‘The Day After Tomorrow’ happen? Explore further More information: Reduced interdecadal variability of Atlantic Meridional Overturning Circulation under global warming. PNAS 2016 ; published ahead of print March 7, 2016, DOI: 10.1073/pnas.1519827113AbstractInterdecadal variability of the Atlantic Meridional Overturning Circulation (AMOC-IV) plays an important role in climate variation and has significant societal impacts. Past climate reconstruction indicates that AMOC-IV has likely undergone significant changes. Despite some previous studies, responses of AMOC-IV to global warming remain unclear, in particular regarding its amplitude and time scale. In this study, we analyze the responses of AMOC-IV under various scenarios of future global warming in multiple models and find that AMOC-IV becomes weaker and shorter with enhanced global warming. From the present climate condition to the strongest future warming scenario, on average, the major period of AMOC-IV is shortened from ∼50 y to ∼20 y, and the amplitude is reduced by ∼60%. These reductions in period and amplitude of AMOC-IV are suggested to be associated with increased oceanic stratification under global warming and, in turn, the speedup of oceanic baroclinic Rossby waves. © 2016 Phys.org Citation: Variability of major oceanic currents driven by climate change (2016, March 17) retrieved 18 August 2019 from https://phys.org/news/2016-03-variability-major-oceanic-currents-driven.html Topographic map of the Nordic Seas and subpolar basins with schematic circulation of surface currents (solid curves) and deep currents (dashed curves) that form a portion of the Atlantic meridional overturning circulation. Colors of curves indicate approximate temperatures. Credit: R. Curry, Woods Hole Oceanographic Institution/Science/USGCRP.
Journal information: Astronomy & Astrophysics © 2019 Science X Network Explore further Schematic representation of the environment towards IRS 67 where three main regions are distinguished. Cold regions traced by DCO+, the disc structure proven by CO isotopologues and S-bearing species, and a PDR associated with the surface layers of the disc, traced by CN, DCN, and carbon-chain molecules. The outflow direction is taken from Bontemps et al. (1996). Credit: Villarmois et al., 2019. Protoplanetary discs represent an important stage in the formation of planets. Astronomers believe that the final composition of planets depends on the chemical process taking place within the disc. Therefore, studies of the initial phase of disc formation could be crucial in improving knowledge of the formation and evolution of planetesimals, planets and other objects.However, such studies are very challenging due to fact that the innermost regions of protoplanetary discs are embedded within large amount of gas and dust. In order to shed more light on the physical structure of these regions, chemical surveys of deeply embedded sources are required.Oph-IRS 67 (IRS 67 for short) is a protobinary system located some 493 light years away in the Ophiuchus star-forming region and part of the L1689 cloud. The two sources in the system are separated by about 90 AU from each other. Previous observations of IRS 67 have shown that it contains a Class I circumbinary disc with an extent of approximately 620 AU. In general, Class I discs represent the bridge between deeply embedded Class 0 sources and the emergence of planet-forming discs, known as Class II sources.However, the researchers found that IRS 67 showcases a particular rich chemistry and bright emission of the c-C3H2 molecule, which is atypical for Class I sources. This unusual chemical composition motivated a trio of astronomers from University of Copenhagen, Denmark, led by Elizabeth Artur de la Villarmois, to investigate this disc in detail.”The purpose of this paper is to explore the structure of a line-rich Class I protobinary source, Oph-IRS 67, and analyze the differences and similarities with Class 0 and Class II sources,” the astronomers wrote.Observations conducted using the SMA instrument allowed the team to detect a range of molecular transitions that trace different physics, such as carbon monoxide (CO) isotopologues, sulphur-bearing species, deuterated species, and carbon-chain molecules.The researchers grouped the detected transitions into three main components: cold regions far from the system, the circumbinary disc, and a ultraviolet-irradiated region likely associated with the surface layers of the disc. “The detected molecular transitions are tracing three main regions: cold regions beyond the circumbinary disc extent, the circumbinary disc, and a PDR [photon-dominated region] likely related with the surface layers of the disc. DCO+ is tracing the cold regions, while the CO isotopologues and the sulphur-bearing species are probing the disc structure,” the paper reads.Moreover, the study found that the continuum emission in IRS 67 is consistent with previous studies, which suggests that dust grains in the disc have grown to larger sizes than the interstellar medium dust particles, or that the dust is optically thick. Summing up the results, the researchers concluded that IRS 67 exhibits chemical similarities with Class 0 sources, while photon-dominated region tracers, such as cyanide (CN), are associated with Class II discs. “IRS 67 is, therefore, a chemical link between these two stages,” the scientists wrote. Citation: Observations unveil chemical structure of the protoplanetary disk Oph-IRS 67 (2019, June 10) retrieved 18 August 2019 from https://phys.org/news/2019-06-unveil-chemical-protoplanetary-disk-oph-irs.html Double star system flips planet-forming disk into pole position Using the Submillimeter Array (SMA), astronomers have conducted a molecular line study of the protoplanetary disk Oph-IRS 67, uncovering essential information about its chemical structure. Results of this study were presented in a paper published June 3 on the arXiv pre-print server. More information: E. Artur de la Villarmois et al. Revealing the chemical structure of the Class I disc Oph-IRS 67, Astronomy & Astrophysics (2019). DOI: 10.1051/0004-6361/201935575 Revealing the chemical structure of the Class I disc Oph-IRS 67, arXiv:1906.00685v1 [astro-ph.SR]. arxiv.org/abs/1906.00685v1 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.
The series of mesmerizing pieces is going to be exhibited from 24 March till 30 March at the Atrium lobby, Taj Palace Hotel.Being a doctor by profession, Singhal’s love for nature inspired her to delve deep into the mysteries of the element and appreciate their finer nuances. She has taken great pleasure in painstakingly converting these connection into expressive colourful strokes and varying textures on the canvas, resulting in ‘magical’ series. Also Read – ‘Playing Jojo was emotionally exhausting’Singhal says, ‘There is a special way that Nature speaks to us. The wind hums, and the ocean dances for us. Even the different hues of green of the foliage, or the fiery reds of fire seem to communicate in a language of their own. It is just that most of the time we are not sensitive enough to lend a patient ear to their story or understand their emotion. Also the elements in a way are representative of the different stages of a human life.’ She added, ‘Childhood may be considered a period of growth(earth and water), youth, a period full of energy and creativity(fire), and old age with its characteristic withering(space and air). The endeavour has also been to characterize the colors into these moulds of human existence.’It would be right to say that all five elements i.e. earth, water, fire, air and space deeply inspire her. And that is how her present collection has come about. Now many colourful experimentations later, she feels buoyant with optimism, and impassioned enough to color the whole world.When: 24 – 30 MarchWhere: Atrium lobby, Taj Palace Hotel
The four-day photography exhibition Portraits Talk by Aman Chotani showcased a new perspective to learning and art imitating life. Chotani has captured some of his most beautiful pictures in
Kolkata: The Majerhat bridge caving-in incident cropped up at the meeting held at Nabanna on Thursdayover preparations for Gangasagar Mela as it is one ofthe crucial routes that pilgrims take to reach the transitpoints in South 24-Parganas through Diamond Harbour Road.With the caving-in, the concerned officials have started pondering as to how exactly around 20 lakh pilgrims would reach the place from Kolkata. Gangasagar Mela takes place in January every year in the Sagar Island. But the planning begins from September onwards and Chief Secretary Malay De held a preparatory meeting in this regard at Nabanna on Thursday. Also Read – Rain batters Kolkata, cripples normal lifeSenior officials from concerned departments including Public Health Engineering, Health, Public Works Department, Transport department, top brass of South 24-Parganas district administration, Kolkata Police personnel and BSNL authorities were present during the meeting.Chief Minister Mamata Banerjee will also hold a meeting later to review the preparations and to ensure that pilgrims from all over the country do not face any inconvenience.Sources said the alternate roads including one through Garden Reach flyover have come up as the routes through which vehicles of pilgrims will pass by in the absence of the Majerhat flyover. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed”Though it is not known yet whether the Majerhat bridge will be reconstructed or not, preliminary discussions were held on Thursday on the basis of the present situation,” said an official adding that the Kolkata Police officers have also come up with their suggestions in this connection.Sources added that there were also discussionson the issues related to the dredging in Muriganga River which is quite essential for smooth operation of vessels to transit pilgrims. The state Irrigation department has assured that all steps would be taken for proper dredging.The state government also needs to make arrangements for buses and vessels.Additional buses are also sent to Sagar Island normally in which pilgrims travel from transit points to the venue.