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 have developed a method for printing optical holographic lenses that could greatly simplify their fabrication. Because the method can be performed quickly and easily, it could potentially be used by astronauts to print lenses while in space for holographic lens telescopes. More information: Qiancheng Zhao, et al. “Printable Nanophotonic Devices via Holographic Laser Ablation.” ACS Nano. DOI: 10.1021/acsnano.5b03165 Group webpage: HB-Nanophotonic Group at the University of Birmingham Explore further The researchers, led by Dr. Haider Butt at the University of Birmingham in the UK, along with coauthors from there and the Harvard Medical School and Wellman Center for Photomedicine at Massachusetts General Hospital in the US, have published a paper on the new holographic lens printing method in a recent issue of ACS Nano.”Using the novel technique of holographic laser ablation, which we previously used for printing holograms, we have demonstrated the printing of optical lenses made of a variety of materials,” Butt told Phys.org. “A complete lens can be fabricated with a single nanosecond laser pulse. Hence the method is fast, flexible, and inexpensive.”While current holographic lens fabrication methods are often expensive, time-consuming, and labor-intensive, the new printing method can produce a lens in just a few seconds using only a single step. The method uses a nanosecond laser pulse to create interference patterns on a transparent substrate coated with light-absorbing materials. The laser is reflected off a concave mirror back onto itself, so that interference occurs between two laser beams traveling in opposite directions. The resulting interference pattern, consisting of circular fringes, is “printed” on a substrate between the two beams, storing the optical information as a holographic lens. The resulting flat, ultra-thin lenses consist of hundreds of nanoscale circular zones that contribute to focusing light.Using this new method, the researchers demonstrated that they could achieve mass production within a few minutes. The method should also work with a wide variety of materials on substrates that are semitransparent, with geometries that are flat, curved, or of other arbitrary form. Besides having niche applications like printing telescope lenses in space, the new printing method could also be used for security, data storage, and biosensors. Due to the flexibility of the fabrication method, lenses can be printed on certain materials that are not compatible with conventional fabrication techniques. In the future, the scientists plan to use the method to print lenses on thin films of semiconductors, with applications in applied optics and infrared imaging. Printable holograms could make holograms more widespread The flat lens is made of a 4-nm-thick gold layer and has an approximate diameter of 1 inch. Scale bars = 200 μm. Credit: Zhao, et al. ©2015 American Chemical Society Diagram of the fabrication method for printing holographic lenses. Credit: Zhao, et al. ©2015 American Chemical Society © 2015 Phys.org Journal information: ACS Nano Citation: Holographic lens printing method could allow printing of telescope lenses in space (2015, September 4) retrieved 18 August 2019 from https://phys.org/news/2015-09-holographic-lens-method-telescope-lenses.html
(a) The intersex produced by a cross between a female Pundamilia pundamilia from Python Island and an orange blotch (OB) Neochromis omnicaeruleus male from Makobe Island. The gonads (b) looked like typical cichlid ovaries. However, a horizontal plane section (c) contained small aggregated dark dots that resembled spermatocytes (marked by arrow). On the gonad (b), this section was located in a whitish tissue (arrow). Credit: Royal Society Open Science (2016). DOI: 10.1098/rsos.150684 © 2016 Phys.org Journal information: Royal Society Open Science Explore further For females, a little semen may go a long way Citation: Female fish develops male organs and impregnates self (2016, March 24) retrieved 18 August 2019 from https://phys.org/news/2016-03-female-fish-male-impregnates.html More information: Ola Svensson et al. Hybridization generates a hopeful monster: a hermaphroditic selfing cichlid, Royal Society Open Science (2016). DOI: 10.1098/rsos.150684AbstractCompared with other phylogenetic groups, self-fertilization (selfing) is exceedingly rare in vertebrates and is known to occur only in one small clade of fishes. Here we report observing one F1-hybrid individual that developed into a functional hermaphrodite after crossing two closely-related sexually reproducing species of cichlids. Microsatellite alleles segregated consistent with selfing and Mendelian inheritance and we could rule out different modes of parthenogenesis including automixis. We discuss why selfing is not more commonly observed in vertebrates in nature, and the role of hybridization in the evolution of novel traits. The team reports that they were studying chichlid fish and at one point bred two different species of the fish, resulting in the birth of several offspring, only one of which later developed male reproductive organs. Such fish, they note reproduce by mixing sperm and egg sin the mouth. In this instance, it appeared that the hybrid ejected sperm into the water and then sucked it into its mouth where it fertilized the eggs that were waiting there. The fish shortly thereafter gave birth to several offspring. Also, the team reports, it was not a onetime occurrence, the fish self fertilized itself many times over the course of a year, giving birth to 42 offspring (both male and female) of which it was both the mother and father. The offspring all appeared normal and reproduced without any of them resorting to selfing. They did all suffer, however, from what scientists call inbreeding depression, where there is minimal genetic diversity, which can lead to birth defects in subsequent generations. Having two genders it is believed was an evolutionary development that came about to allow for genetic diversity, after all.Selfing is not unheard of in the animal kingdom, other species such as mangrove killifish engage in it as part of their normal reproductive habits—but in their case, it is one born of necessity when there are no potential mates around—it is also an adaption that came about out of necessity. The researchers believe the selfing observed in the cichlid female likely came about due to its parents having different sex-determining genes, and that it was almost certainly an oddity, and thus not likely to happen again anytime soon. They note also that it is not likely that this was the first occurrence of selfig in the species, such instances have likely gone underreported due to its rarity. (Phys.org)—A female cichlid hybrid fish has been observed to have grown male reproductive organs, impregnate itself and then to have offspring, a team of researchers in the U.K. are reporting in a paper published in the journal Royal Society Open Science. They call the process ‘selfing’ and suggest it is very rare in vertebrates. 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)—For the first time, physicists have demonstrated that clients who possess only classical computers—and no quantum devices—can outsource computing tasks to quantum servers that perform blind quantum computing. “Blind” means the quantum servers do not have full information about the tasks they are computing, which ensures that the clients’ computing tasks are kept secure. Until now, all blind quantum computing demonstrations have required that clients have their own quantum devices in order to delegate tasks for blind quantum computing. The team of physicists, led by Jian-Wei Pan and Chao-Yang Lu at the University of Science and Technology of China, have published a paper on the demonstration of blind quantum computing for classical clients in a recent issue of Physical Review Letters.”We have demonstrated for the first time that a fully classical client can delegate a quantum computation to untrusted quantum servers while maintaining full privacy,” Lu told Phys.org.The idea behind blind quantum computing is that, while there are certain computing tasks that quantum computers can perform exponentially better than classical computers, quantum computing still involves expensive, complex hardware that will make it inaccessible for most clients. So instead of everyone owning their own quantum computing devices, blind quantum computing makes it possible for clients to outsource their computing tasks to quantum servers that do the job for them. Ensuring that the quantum computing is performed blindly is important, since many of the potential applications of quantum computing will likely require a high degree of security.Although several blind quantum computing protocols have been performed in the past few years, they have all required that the clients have the ability to perform certain quantum tasks, such as prepare or measure qubit states. Eliminating this requirement will provide greater access to blind quantum computing, since most clients only have classical computing systems. In the new study, the physicists experimentally demonstrated that a classical client can outsource a simple problem (factoring the number 15) to two quantum servers that do not fully know what problem they are solving. This is because each server completes part of the task, and it is physically impossible for the servers to communicate with each other. To ensure that the quantum servers are performing their tasks honestly, the client can give them “dummy tasks” that are indistinguishable from the real task to test their honesty and correctness. The researchers expect that the new method can be scaled up for realizing secure, outsourced quantum computing, which could one day be implemented on quantum cloud servers and make the power of quantum computing widely available.”Blind quantum computing protocol is an important privacy-preserving technique for future secure quantum cloud computing and secure quantum networks,” Lu said. “Applying our implemented blind quantum computing protocol, classical clients could delegate computation tasks to servers ‘in the cloud’ blindly and correctly without directly owning quantum devices. It saves resources and makes scalable quantum computing possible.”In the future, the physicists want to make blind quantum computing even easier for clients by further reducing the requirements.”We plan to study more robust blind quantum computing protocols with fewer required resources and fewer constraints theoretically and experimentally,” Lu said. “We will also explore blind quantum computing for more application scenarios, such as multi-user blind quantum computing, publicly verifiable quantum computing, and secure multi-party quantum computing.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Blind quantum computing for everyone (2017, August 11) retrieved 18 August 2019 from https://phys.org/news/2017-08-quantum.html Credit: CC0 Public Domain Developing quantum algorithms for optimization problems Journal information: Physical Review Letters More information: He-Liang Huang et al. “Experimental Blind Quantum Computing for a Classical Client.” Physical Review Letters. DOI: 10.1103/PhysRevLett.119.050503 , Also at arXiv:1707.00400 [quant-ph] Explore further © 2017 Phys.org
The VLA Hi column density contours overlaid on the V-band image of JO206 from WINGS (V-band image from Moretti et al. 2014). Credit: Ramatsoku et al., 2019. Explore further At about 85 billion solar masses, JO206 is a massive “jellyfish” galaxy hosting an active galactic nucleus (AGN) and a member of the IIZw108 galaxy cluster at a redshift of approximately 0.049. The so-called jellyfish galaxies have one-sided tails seemingly stripped from the galaxy’s main body.In the case of JO206, astronomers have assigned the highest jellyfish morphological classification of 5.0 as it showcases the most recognizable tail of debris material that is apparently stripped from the main body. The stripped tail of material is thought to be the result of ram-pressure stripping due to the intra-cluster medium (ICM) of IIZw108.Studies of jellyfish galaxies, in particular the examination of star formation activity during the process of gas stripping, could be crucial in improving the understanding of galactic evolution in general. One method of such studies is the investigation of neutral atomic hydrogen (HI) in these galaxies.Recently, a team of astronomers led by Mpati Ramatsoku of the Astronomical Observatory of Cagliari in Italy used this technique to study JO206. The research was focused on the galaxy’s long tail of ionized gas and how this feature affects the interstellar medium, as well as star formation activity. The observational campaign was carried out using the VLA telescope as part of the GAs Stripping Phenomena survey (GASP).”As part of the ESO MUSE GASP survey, we have studied the HI gas phase of the prototypical ‘jellyfish’ galaxy in the sample, namely, JO206,” the astronomers wrote in the paper.According to the study, the neutral atomic hydrogen distribution in JO206 is perturbed and exhibits a one-sided HI tail from the optical disc. The tail extends over 293,000 light years and has an HI mass of about 1.8 billion solar masses. This means that the tail’s neutral gas mass currently constitutes about 60 percent of the whole galaxy’s HI mass.The research found that JO206 is generally undergoing an enhanced star formation activity compared to similar galaxies with the same stellar mass. JO206’s HI depletion time was estimated to be 500 million years, which is shorter than that of ordinary spiral galaxies observed to date.Moreover, the astronomers detected a strong correlation between the observed cold gas and ionized emission in JO206, seen both in the galaxy main body and the tail. “This indicates a strong link between the presence of cold gas and the recent star formation across all of the galaxy,” the scientists concluded.In addition, the study also found that that the star formation efficiency in the disc of JO206 is on average about 10 times higher compared to the tail for a given HI surface density. The researchers noted that in general, the inner and outer parts of JO206 have relatively higher star formation efficiencies compared to other galaxies in the literature.Summing up the research, the authors of the paper concluded that JO206, at its current stripping stage, still has fuel to form new stars along its tail and disc. “Comparing this galaxy with others in the GASP sample in different environments will clarify whether the environment played a pivotal role in the enhanced observed star formation or whether other specific physical conditions are responsible,” the astronomers wrote. Using the Very Large Array (VLA), astronomers have conducted observations of neutral gas in the galaxy JO206. Results of these observations provide important information regarding gas stripping and enhanced star formation in this galaxy. The findings are detailed in a paper published June 9 on arXiv.org. © 2019 Science X Network This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Observations reveal gas stripping and enhanced star formation in the galaxy JO206 (2019, June 19) retrieved 18 August 2019 from https://phys.org/news/2019-06-reveal-gas-star-formation-galaxy.html Journal information: Monthly Notices of the Royal Astronomical Society Research provides insights into molecular gas in the massive spiral galaxy NGC 5908 More information: M Ramatsoku et al. GASP XVII. HI imaging of the jellyfish galaxy JO206: gas stripping and enhanced star formation., Monthly Notices of the Royal Astronomical Society (2019). DOI: 10.1093/mnras/stz1609 , https://arxiv.org/abs/1906.03686
Various artists from all across the Indian subcontinent came together to showcase their works in Delhi and brought in forgotten flavours of South Asia.The show, curated by Batasha Mathur and Kiran Chaudhary at Experimental Art Gallery, was inaugurated with a special preview for the capital’s glitterati on Saturday. The main attraction of the show were the scintillating art works from India, Bhutan and Pakistan. About 20 artists contributed, including K Ravi, Arun Pandit, Sanjay Bhattacharya, Karma, Imrana Tanveer, Vijay Kalyan, Gopi Gajwani, Mashkoor Raza, K Balamurli, to name a few. Works of Indian painter Vaikuntam and Pakistani artist Salman Farooqi were admired the most by the visitors, who were equally chramed by the scenic portraits by the former and the anguished women by the latter. Also Read – ‘Playing Jojo was emotionally exhausting’Farooqi’s work has been intensely inspired by a genre dealing with an intimate perception of landscapes and cityscapes. He has held many group and solo shows in different cities of Pakistan and the Middle East. In some of his works, we found images of dark interiors with old-style table, chairs and ornately carved head board set against bright sunlight coming in through open windows. Juxtaposed with this were the various feminine expressions that invoked corresponding dark moods.Vaikuntam’s paintings capture simple lifestyle of villagers, the paddy fields, toddy pots on shoulders of men, the household chores, temple rituals depicting rural life of the country. Colour palette for some paintings were bold shades of red, blue, black whereas some had pastel shades of yellow, blue, saffron and more.
Climbing the stairs can not only help you stay physically fit but also improve brain health, suggests new research.“There already exist many ‘Take the stairs’ campaigns in office environments and public transportation centres,” said lead researcher Jason Steffener from Concordia University in Montreal, Canada.“This study shows that these campaigns should also be expanded for older adults so that they can work to keep their brains young,” said Steffener. The researchers found that education also played a positive role in brain health. Also Read – ‘Playing Jojo was emotionally exhausting’The study, published in the journal Neurobiology of Aging, showed that the more flights of stairs a person climbs and the more years of school a person completes, the “younger” their brain physically appears.For the study, Steffener and his co-authors used magnetic resonance imaging (MRI) to non-invasively examine the brains of 331 healthy adults who were aged between 19 to 79. They measured the volume of grey matter found in participants’ brains because its decline, caused by neural shrinkage and neuronal loss, is a very visible part of the chronological aging process. Then, they compared brain volume to the participants’ reported number of flights of stairs climbed and years of schooling completed.“This is encouraging because it demonstrates that a simple thing like climbing stairs has great potential as an intervention tool to promote brain health,” Steffener said.