Evolution of Proto-Neutron Stars with Quarks

Neutrino fluxes from proto-neutron stars with and without quarks are studied. Observable differences become apparent after 10--20 s of evolution. Sufficiently massive stars containing negatively-charged, strongly interacting, particles collapse to black holes during the first minute of evolution. Since the neutrino flux vanishes when a black hole forms, this is the most obvious signal that quarks (or other types of strange matter) have appeared. The metastability timescales for stars with quarks are intermediate between those containing hyperons and kaon condensates.Comment: 4 pages including 4 figures. Version with minor revisions. To be published in Physical Review Letter

Correlation between magnetic resonance imaging and arthroscopy in internal derangement of knee

Background: Ligament injuries apart from fractures are more common in the knee joint owing to its complex anatomy. They account for a large number of referrals to our hospital, both from the general practitioner and from the accident and emergency department. Although there have been studies in literature comparing MRI with arthroscopy, the continuing improvement in diagnostic methods now available makes it especially important to compare the results and recommendations offered in the literature.Methods: The aim of this study was to find out the diagnostic accuracy of MRI scans and to examine the value of MRI as a standard preoperative examination correlating them with the gold standard of arthroscopy. This is a prospective study involving 57 patients who were admitted in Department of Orthopaedics, Mahatma Gandhi Medical College and Research Institute, with the history of injury to the knee and diagnosed to have internal derangement of the knee clinically, using standardized clinical tests. MRI of the affected knee joint was done for all these patients either before or after admission. The patients were then subjected to diagnostic and therapeutic arthroscopy.Results: The sensitivity of MRI in comparison with Arthroscopy was 100% in all studied lesions. The specificity of MRI in comparison with Arthroscopy was 94.1%, 98.1%, 100% and 97.6% for ACL, PCL, Medial meniscus and Lateral meniscus respectively.Conclusions: According to our study MRI is a very good at determining the normal anatomy of the intra articular structures of the knee joint and is highly reliable in excluding pathology, in our case tear in ligaments. Hence we recommend MRI in doubtful cases of internal derangement of the knee joint whereby unnecessary diagnostic arthroscopy can be avoided which can significantly bring down the economic burden among rural population

Influence of fatigue on superconducting REBCO tapes under repeated cyclic tensile, bending and twisting loads:A simulation-based investigation

The effect of repeated cyclic loading on the superconducting REBCO tape under tensile, bending, and torsional loadings is investigated. The Fatigue Usage Factor (FUS) is calculated for each cyclic loading condition to identify degradation using the Matake criterion. The thicknesses of the tapes' constituent layers are also varied to identify the relative influence of each layer on overall fatigue performance. When the tape was subjected to fatigue-type loading, the thickness of the copper and Hastelloy layers was found to play a significant role. This holds true under tensile, bending, and twisting loading conditions. However, out of the three loading conditions, bending exhibits the greatest variation in FUS value with changes in Hastelloy and copper layer thickness. The maximum value of the fatigue usage factor is observed in the edges of the Hastelloy layer in all three loading cases. It has been found that the properties of the layer material, as well as the adjacent layer, play an important role in determining the fatigue strength of the tape.</p

KCa4(BO3)(3):Ln(3+) (Ln = Dy, Eu, Tb) phosphors for near UV excited white-light-emitting diodes

A series of doped KCa4(BO3)(3):Ln(3+) (Ln: Dy, Eu and Tb) compositions were synthesized by solid-state reaction method and their photoluminescent properties were systematically investigated to ascertain their suitability for application in white light emitting diodes. The X-ray diffraction (XRD) and nuclear magnetic resonance (MAS-NMR) data indicates that Ln(3+)-ions are successfully occupied the non-centrosymmetric Ca2+ sites, in the orthorhombic crystalline phase of KCa4(BO3)(3) having space group Ama2, without affecting the boron chemical environment. The present phosphor systems could be efficiently excitable at the broad UV wavelength region, from 250 to 350 nm, compatible to the most commonly available UV light-emitting diode (LED) chips. Photoluminescence studies revealed optimal near white-light emission for KCa4(BO3)(3) with 5 wt.% Dy3+ doping, while warm white-light (CIE; X = 0.353, Y = 0.369) is obtained at 1wt.% Dy3+ ion concentration. The principle of energy transfer between Eu3+ and Tb3+ also demonstrates the potential white-light from KCa4(BO3)(3):Eu3+, Tb3+ phosphor. Whereas, single Tb3+ and Eu3+-doped systems showed bright green (Tb3+) and red (Eu3+) emissions, respectively. Having structural flexibility along with remarkable chemical/thermal stability and suitable quantum efficiency these phosphors can be promising candidates as white-light-emitter for near UV LEDs. Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4794189

Rapid Assessment of Avoidable Blindness in India

BACKGROUND: Rapid assessment of avoidable blindness provides valid estimates in a short period of time to assess the magnitude and causes of avoidable blindness. The study determined magnitude and causes of avoidable blindness in India in 2007 among the 50+ population. METHODS AND FINDINGS: Sixteen randomly selected districts where blindness surveys were undertaken 7 to 10 years earlier were identified for a follow up survey. Stratified cluster sampling was used and 25 clusters (20 rural and 5 urban) were randomly picked in each district.. After a random start, 100 individuals aged 50+ were enumerated and examined sequentially in each cluster. All those with presenting vision = 50 years were enumerated, and 94.7% examined. Based on presenting vision,, 4.4% (95% Confidence Interval[CI]: 4.1,4.8) were severely visually impaired (vision<6/60 to 3/60 in the better eye) and 3.6% (95% CI: 3.3,3.9) were blind (vision<3/60 in the better eye). Prevalence of low vision (<6/18 to 6/60 in the better eye) was 16.8% (95% CI: 16.0,17.5). Prevalence of blindness and severe visual impairment (<6/60 in the better eye) was higher among rural residents (8.2%; 95% CI: 7.9,8.6) compared to urban (7.1%; 95% CI: 5.0, 9.2), among females (9.2%; 95% CI: 8.6,9.8) compared to males (6.5%; 95% CI: 6.0,7.1) and people above 70 years (20.6%; 95% CI: 19.1,22.0) compared to people aged 50-54 years (1.3%; 95% CI: 1.1,1.6). Of all blindness, 88.2% was avoidable. of which 81.9% was due to cataract and 7.1% to uncorrected refractive errors/uncorrected aphakia. CONCLUSIONS: Cataract and refractive errors are major causes of blindness and low vision and control strategies should prioritize them. Most blindness and low vision burden is avoidable

Ring splitting of azetidin-2-ones via radical anions

The radical anions of azetidin-2-ones, generated by UV-irradiation in the presence of triethylamine, undergo ring-splitting via N-C4 or C3-C4 bond breaking, leading to open-chain amides. This reactivity diverges from that found for the neutral excited states, which is characterised by alpha-cleavage. The preference for beta-cleavage is supported by DFT theoretical calculations on the energy barriers associated with the involved transition states. Thus, injection of one electron into the azetidin-2-one moiety constitutes a complementary activation strategy which may be exploited to produce new chemistry.Financial support from the MICINN (Grants CTQ-2010-14882, CTQ-2009-13699 and JCI-2010-06204), Generalitat Valenciana (Prometeo 2008/90), from CSIC (JAEDOC 101-2011) and from the UPV (Grant No. 20100994 and MCI Program) is gratefully acknowledged.Pérez Ruiz, R.; Sáez Cases, JA.; Domingo, LR.; Jiménez Molero, MC.; Miranda Alonso, MÁ. (2012). Ring splitting of azetidin-2-ones via radical anions. Organic and Biomolecular Chemistry. 10(39):7928-7932. https://doi.org/10.1039/c2ob26528aS79287932103

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected