266 research outputs found

    The Emergent Flux and Effective Temperature of Delta Canis Majoris

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    New angular diameter determinations for the bright southern F8 supergiant Delta CMa enable the bolometric emergent flux and effective temperature of the star to be determined with improved accuracy. The spectral flux distribution and bolometric flux have been determined from published photometry and spectrophotometry and combined with the angular diameter to derive the bolometric emergent flux F = (6.50 plus/minus 0.24) x 10^7 W/m^2 and the effective temperature Teff = 5818 plus/minus 53 K. The new value for the effective temperature is compared with previous interferometric and infrared flux method determinations. The accuracy of the effective temperature is now limited by the uncertainty in the bolometric flux rather than by the uncertainty in the angular diameter.Comment: 8 pages, 4 figure

    Does Baseline Severity of Arm Pain Influence Outcomes Following Single-Level Anterior Cervical Discectomy and Fusion?

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    Study Design Retrospective cohort. Purpose To assess preoperative arm pain severity influence on postoperative patient-reported outcomes measures (PROMs) and minimal clinically important difference (MCID) achievement following single-level anterior cervical discectomy and fusion (ACDF). Overview of Literature There is evidence that preoperative symptom severity can affect postoperative outcomes. Few have evaluated this association between preoperative arm pain severity and postoperative PROMs and MCID achievement following ACDF. Methods Individuals undergoing single-level ACDF were identified. Patients were grouped by preoperative Visual Analog Scale (VAS) arm ≤8 vs. >8. PROMs collected preoperatively and postoperatively included VAS-arm/VAS-neck/Neck Disability Index (NDI)/12-item Short Form (SF-12) Physical Composite Score (PCS)/SF-12 mental composite score (MCS)/Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF). Demographics, PROMs, and MCID rates were compared between cohorts. Results A total of 128 patients were included. The VAS arm ≤8 cohort significantly improved for all PROMs excepting VAS arm at 1-year/2-years, SF-12 MCS at 12-weeks/1-year/2-years, and SF-12 PCS/PROMIS-PF at 6-weeks, only (p≤0.021, all). The VAS arm >8 cohort significantly improved for VAS neck at all timepoints, VAS arm from 6-weeks to 1-year, NDI from 6-weeks to 6-months, and SF-12 MCS/PROMIS-PF at 6-months (p≤0.038, all). Postoperatively, the VAS arm >8 cohort had higher VAS-neck (6 weeks/6 months), VAS-arm (12 weeks/6 months), NDI (6 weeks/6 months), lower SF-12 MCS (6 weeks/6 months), SF-12 PCS (6 months), and PROMIS-PF (12 weeks/6 months) (p≤0.038, all). MCID achievement rates were higher among the VAS arm >8 cohort for the VAS-arm at 6-weeks/12-weeks/1-year/overall and NDI at 2 years (p≤0.038, all). Conclusions Significance in PROM score differences between VAS arm ≤8 vs. >8 generally dissipated at the 1-year and 2-year time-point, although higher preoperative arm pain patients suffered from worse pain, disability, and mental/physical function scores. Furthermore, clinically meaningful rates of improvement were similar throughout the vast majority of timepoints for all PROMs studied

    Clinical Usefulness of Bright White Light Therapy for Depressive Symptoms in Cancer Survivors: Results from a Series of Personalized (N-of-1) Trials

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    Publisher's version (útgefin grein)Purpose: Little is known about the effectiveness of bright white light therapy (BWL) for depressive symptoms in cancer survivors, many of whom prefer non-pharmacological treatments. The purpose of this study was to compare the effectiveness of BWL versus dim red light therapy (DRL) on depressive symptoms within individual cancer survivors using personalized (N-of-1) trials. Methods: Cancer survivors with at least mild depressive symptoms were randomized to one of two treatment sequences consisting of counterbalanced crossover comparisons of three-weeks of lightbox-delivered BWL (intervention) or DRL (sham) for 30 min each morning across 12 weeks. A smartphone application guided cancer survivors through the treatment sequence and facilitated data collection. Cancer survivors tracked end-of-day depressive symptoms (primary outcome) and fatigue using visual analog scales. Within-patient effects of BWL were assessed using an autoregressive model with adjustment for linear time trends. Results: Eight of nine cancer survivors completed the 12-week protocol. Two survivors reported significantly (i.e., p < 0.05) lower depressive symptoms (-1.3 +/- 0.5 and -1.30 +/- 0.9 points on a 10-point scale), five reported no difference in depressive symptoms, and one reported higher depressive symptoms (+1.7 +/- 0.6 points) with BWL versus DRL. Eight of nine cancer survivors recommended personalized trials of BWL to others. Conclusions: There were heterogeneous effects of three-week BWL on self-reported depressive symptoms among cancer survivors, with some finding a benefit but others finding no benefit or even harm. Implications for Cancer Survivors: Personalized trials can help cancer survivors learn if BWL is helpful for improving their depressive symptoms.This research was funded in part with Federal funds from the National Cancer Institute, NIH, under Contract No. HHSN261200800001E. Drs. Kronish, Davidson, and Cheung received additional support from the National Library of Medicine (R01LM012836)."Peer Reviewed

    The Development of Metabolomic Sampling Procedures for Pichia pastoris, and Baseline Metabolome Data

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    Metabolic profiling is increasingly being used to investigate a diverse range of biological questions. Due to the rapid turnover of intracellular metabolites it is important to have reliable, reproducible techniques for sampling and sample treatment. Through the use of non-targeted analytical techniques such as NMR and GC-MS we have performed a comprehensive quantitative investigation of sampling techniques for Pichia pastoris. It was clear that quenching metabolism using solutions based on the standard cold methanol protocol caused some metabolite losses from P. pastoris cells. However, these were at a low level, with the NMR results indicating metabolite increases in the quenching solution below 5% of their intracellular level for 75% of metabolites identified; while the GC-MS results suggest a slightly higher level with increases below 15% of their intracellular values. There were subtle differences between the four quenching solutions investigated but broadly, they all gave similar results. Total culture extraction of cells + broth using high cell density cultures typical of P. pastoris fermentations, was an efficient sampling technique for NMR analysis and provided a gold standard of intracellular metabolite levels; however, salts in the media affected the GC-MS analysis. Furthermore, there was no benefit in including an additional washing step in the quenching process, as the results were essentially identical to those obtained just by a single centrifugation step. We have identified the major high-concentration metabolites found in both the extra- and intracellular locations of P. pastoris cultures by NMR spectroscopy and GC-MS. This has provided us with a baseline metabolome for P. pastoris for future studies. The P. pastoris metabolome is significantly different from that of Saccharomyces cerevisiae, with the most notable difference being the production of high concentrations of arabitol by P. pastoris

    Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3

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    Context. Recently, the high-energy (HE, 0.1-100 GeV) γ\gamma-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic γ\gamma-ray binary. Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) γ\gamma-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Energy spectra are obtained for the orbit-averaged data set, and for the orbital phase bin around the VHE maximum. Results. VHE γ\gamma-ray emission is detected with a statistical significance of 6.4 σ\sigma. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1101-10 TeV energy range is (1.4±0.2)×1035(1.4 \pm 0.2) \times 10^{35} erg/s. A luminosity of (5±1)×1035(5 \pm 1) \times 10^{35} erg/s is reached during 20% of the orbit. HE and VHE γ\gamma-ray emissions are anti-correlated. LMC P3 is the most luminous γ\gamma-ray binary known so far.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&

    A Novel Secretion Pathway of Salmonella enterica Acts as an Antivirulence Modulator during Salmonellosis

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    Salmonella spp. are Gram-negative enteropathogenic bacteria that infect a variety of vertebrate hosts. Like any other living organism, protein secretion is a fundamental process essential for various aspects of Salmonella biology. Herein we report the identification and characterization of a horizontally acquired, autonomous and previously unreported secretion pathway. In Salmonella enterica serovar Typhimurium, this novel secretion pathway is encoded by STM1669 and STM1668, designated zirT and zirS, respectively. We show that ZirT is localized to the bacterial outer membrane, expected to adopt a compact β-barrel conformation, and functions as a translocator for ZirS. ZirS is an exoprotein, which is secreted into the extracellular environment in a ZirT-dependent manner. The ZirTS secretion pathway was found to share several important features with two-partner secretion (TPS) systems and members of the intimin/invasin family of adhesions. We show that zirTS expression is affected by zinc; and that in vivo, induction of zirT occurs distinctively in Salmonella colonizing the small intestine, but not in systemic sites. Additionally, strong expression of zirT takes place in Salmonella shed in fecal pellets during acute and persistent infections of mice. Inactivation of ZirTS results in a hypervirulence phenotype of Salmonella during oral infection of mice. Cumulatively, these results indicate that the ZirTS pathway plays a unique role as an antivirulence modulator during systemic disease and is involved in fine-tuning a host–pathogen balance during salmonellosis
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