10 research outputs found

    Observational Constraints on the Angular and Spectral Distributions of Photons in Gamma-Ray Burst Sources

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    The typical spectra of gamma-ray bursts (GRBs) are discussed in the context of the compactness problem for GRB sources and how it is resolved in the popular fireball model. In particular, observational (model-independent) constraints on the collimation of the gamma-rays and the dependence of the collimation angle on the photon energy are considered. The fact that the threshold for the creation of ee+e^{-}e^{+} pairs depends on the angle between the momenta of the annihilating photons in the GRB source provides an alternative solution to the compactness problem. A new approach to explaining GRBs, taking into account the angular dependence for pair creation, is proposed, and the main features of a scenario describing a GRB source with a total (photon) energy smaller or of the order of 104910^{49} erg are laid out. Thus, we are dealing with an alternative to an ultra-relativistic fireball, if it turns out (as follows from observations) that all "long" GRBs are associated with normal (not peculiar) core-collapse supernovae. The effects of radiation pressure and the formation of jets as a consequence of even a small amount of anisotropy in the total radiation field in a (compact) GRB source are examined in this alternative model. Possible energy release mechanisms acting in regions smaller or of the order of 10810^{8} cm in size (a compact model for a GRB) are discussed. New observational evidence for such compact energy release in the burst source is considered.Comment: 15 pages, no figures, no table

    The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Ixekizumab Demonstrates Consistent Efficacy Versus Adalimumab in Biologic Disease-Modifying Anti-rheumatic Drug-Naïve Psoriatic Arthritis Patients Regardless of Psoriasis Severity : 52-Week Post Hoc Results from SPIRIT-H2H

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    Introduction: Ixekizumab, a selective interleukin-17A antagonist, was compared with adalimumab in the SPIRIT-H2H study (NCT03151551) in patients with psoriatic arthritis (PsA) and concomitant psoriasis. This post hoc analysis reports outcomes to week 52 in patients from SPIRIT-H2H, stratified by baseline psoriasis severity. Methods: SPIRIT-H2H was a 52-week, multicenter, randomized, open-label, rater-blinded, parallel-group study of biologic disease-modifying antirheumatic drug (DMARD)-naïve patients (N = 566) with PsA and active psoriasis (≥ 3% body surface area involvement). Patients were randomized to ixekizumab or adalimumab (1:1) with stratification by baseline concomitant use of conventional synthetic DMARDs and psoriasis severity (with/without moderate-to-severe psoriasis). Patients received on-label dosing according to psoriasis severity. The primary endpoint was the proportion of patients simultaneously achieving ≥ 50% improvement in American College of Rheumatology criteria (ACR50) and 100% improvement in Psoriasis Area Severity Index (PASI100) at week 24. Secondary endpoints included musculoskeletal, disease activity (defined by composite indices), skin and nail, quality of life and safety outcomes. In this post hoc analysis, primary and secondary endpoints of SPIRIT-H2H were analyzed by baseline psoriasis severity. Results: A greater proportion of patients achieved the combined endpoint of ACR50 + PASI100 and PASI100 with ixekizumab compared with adalimumab at weeks 24 and 52, regardless of baseline psoriasis severity. ACR response rates were similar for ixekizumab and adalimumab across both patient subgroups. For musculoskeletal outcomes, similar efficacy was seen for ixekizumab and adalimumab, but ixekizumab showed greater responses for skin outcomes regardless of psoriasis severity. The safety profiles of ixekizumab and adalimumab were consistent between subgroups. Conclusions: Regardless of baseline psoriasis severity, ixekizumab demonstrated greater efficacy than adalimumab with respect to simultaneous achievement of ACR50 + PASI100, and showed consistent and sustained efficacy across PsA-related domains. It also demonstrated higher response rates for skin outcomes. These subgroup analyses highlight the efficacy of ixekizumab in patients with PsA irrespective of the severity of concomitant psoriasis

    Additional Support for Schizophrenia Linkage on Chromosomes 6 and 8:A Multicenter Study

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    Mitochondrial physiology: Gnaiger Erich et al ― MitoEAGLE Task Group

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