Evidence of magnetic field decay in massive main-sequence stars

A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of massive stars are currently not well understood. We compile a catalogue of 389 massive main-sequence stars, 61 of which are magnetic, and derive their fundamental parameters and ages. The two samples contain stars brighter than magnitude 9 in the V band and range in mass between 5 and 100 Msun. We find that the fractional main-sequence age distribution of all considered stars follows what is expected for a magnitude limited sample, while that of magnetic stars shows a clear decrease towards the end of the main sequence. This dearth of old magnetic stars is independent of the choice of adopted stellar evolution tracks, and appears to become more prominent when considering only the most massive stars. We show that the decreasing trend in the distribution is significantly stronger than expected from magnetic flux conservation. We also find that binary rejuvenation and magnetic suppression of core convection are unlikely to be responsible for the observed lack of older magnetic massive stars, and conclude that its most probable cause is the decay of the magnetic field, over a time span longer than the stellar lifetime for the lowest considered masses, and shorter for the highest masses. We then investigate the spin-down ages of the slowly rotating magnetic massive stars and find them to exceed the stellar ages by far in many cases. The high fraction of very slowly rotating magnetic stars thus provides an independent argument for a decay of the magnetic fields.Comment: Accepted for publication on A&A; 9 pages, 8 figure

Survey of sediment quality in Sabine Lake, Texas and vicinity

The toxicity of sediments in Sabine Lake, Texas, and adjoining Intracoastal Waterway canals was determined as part of bioeffects assessment studies managed by NOAA’s National Status and Trends Program. The objectives of the survey were to determine: (1) the incidence and degree of toxicity of sediments throughout the study area; (2) the spatial patterns (or gradients) in chemical contamination and toxicity, if any, throughout the study area; (3) the spatial extent of chemical contamination and toxicity; and (4) the statistical relationships between measures of toxicity and concentrations of chemicals in the sediments. Surficial sediment samples were collected during August, 1995 from 66 randomly-chosen locations. Laboratory toxicity tests were performed as indicators of potential ecotoxicological effects in sediments. A battery of tests was performed to generate information from different phases (components) of the sediments. Tests were selected to represent a range in toxicological endpoints from acute to chronic sublethal responses. Toxicological tests were conducted to measure: reduced survival of adult amphipods exposed to solid-phase sediments; impaired fertilization success and abnormal morphological development in gametes and embryos, respectively, of sea urchins exposed to pore waters; reduced metabolic activity of a marine bioluminescent bacteria exposed to organic solvent extracts; and induction of a cytochrome P-450 reporter gene system in exposures to solvent extracts of the sediments. Chemical analyses were performed on portions of each sample to quantify the concentrations of trace metals, polynuclear aromatic hydrocarbons, and chlorinated organic compounds. Correlation analyses were conducted to determine the relationships between measures of toxicity and concentrations of potentially toxic substances in the samples. Based upon the compilation of results from chemical analyses and toxicity tests, the quality of sediments in Sabine Lake and vicinity did not appear to be severely degraded. Chemical concentrations rarely exceeded effects-based numerical guidelines, suggesting that toxicant-induced effects would not be expected in most areas. None of the samples was highly toxic in acute amphipod survival tests and a minority (23%) of samples were highly toxic in sublethal urchin fertilization tests. Although toxic responses occurred frequently (94% of samples) in urchin embryo development tests performed with 100% pore waters, toxicity diminished markedly in tests done with diluted pore waters. Microbial bioluminescent activity was not reduced to a great degree (no EC50 <0.06 mg/ml) and cytochrome P-450 activity was not highly induced (6 samples exceeded 37.1 ug/g benzo[a]pyrene equivalents) in tests done with organic solvent extracts. Urchin embryological development was highly correlated with concentrations of ammonia and many trace metals. Cytochrome P450 induction was highly correlated with concentrations of a number of classes of organic compounds (including the polynuclear aromatic hydrocarbons and chlorinated compounds). (PDF contains 51 pages

One-pot three-step thioconjugate addition-oxidation-Diels–Alder reactions of ethyl propiolate

Ethyl propiolate undergoes one-pot three-step thioconjugate addition-oxidation-Diels–Alder cycloaddition when treated with a variety of thiols in the presence of catalytic base, meta-chloroperbenzoic acid, lithium perchlorate, and cyclopentadiene. The reaction of S‑aryl thiols is catalyzed by trialkylamines, and the reaction of aliphatic thiols requires catalytic alkoxide base. Yields of the major diastereomer of the conveniently functionalized bicyclic products range from 47 to 81% depending upon the thiol reactant, which compares favorably to yields observed when the entire synthesis is performed step by step

One-pot synthesis of (Z)-B-sulfonyl enoates from ethyl propiolate

B-Sulfonyl enoates may be synthesized through a one-pot two-step sequence from ethyl propiolate with good to excellent selectivity for the Z isomer. Trialkylamines catalyze thioconjugate additions of aryl thiols, and alkoxides catalyze the addition of aliphatic thiols. Addition of meta-chloroperbenzoic acid (mCPBA) and LiClO4 to the reaction mixture provides rapid access to the sulfonyl enoates. Yields of the pure Z isomer range from 51 – 90%

The pervasive nature of heterodox economic spaces at a time of neoliberal crisis: towards a “postneoliberal” anarchist future

Re-reading the economic landscape of the western world as a largely non-capitalist landscape composed of economic plurality, this paper demonstrates how economic relations in contemporary western society are often embedded in non-commodified practices such as mutual aid, reciprocity, co-operation and inclusion. By highlighting how the long-overlooked lived practices in the contemporary world of production, consumption and exchange are heavily grounded in the very types and essences of non-capitalist economic relations that have long been proposed by anarchistic visions of employment and organization, this paper displays that such visions are far from utopian: they are embedded firmly in the present. Through focusing on the pervasive nature of heterodox economic spaces in the UK in particular, some ideas about how to develop an anarchist future of work and organization will be proposed. The outcome is to begin to engage in the demonstrative construction of a future based on mutualism and autonomous modes of organization and representation. © 2012 The Authors. Antipode© 2012 Antipode Foundation Ltd.

Calcium binding and allosteric signaling mechanisms for the sarcoplasmic reticulum Ca 2+ ATPase

The sarcoplasmic reticulum Ca 2+ ATPase (SERCA) is a membrane‐bound pump that utilizes ATP to drive calcium ions from the myocyte cytosol against the higher calcium concentration in the sarcoplasmic reticulum. Conformational transitions associated with Ca 2+ ‐binding are important to its catalytic function. We have identified collective motions that partition SERCA crystallographic structures into multiple catalytically‐distinct states using principal component analysis. Using Brownian dynamics simulations, we demonstrate the important contribution of surface‐exposed, polar residues in the diffusional encounter of Ca 2+ . Molecular dynamics simulations indicate the role of Glu309 gating in binding Ca 2+ , as well as subsequent changes in the dynamics of SERCA's cytosolic domains. Together these data provide structural and dynamical insights into a multistep process involving Ca 2+ binding and catalytic transitions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93731/1/2129_ftp.pd

Early development of spasticity following stroke: a prospective, observational trial

This study followed a cohort of 103 patients at median 6 days, 6 and 16 weeks after stroke and recorded muscle tone, pain, paresis, Barthel Index and quality of life score (EQ-5D) to identify risk-factors for development of spasticity. 24.5% of stroke victims developed an increase of muscle tone within 2 weeks after stroke. Patients with spasticity had significantly higher incidences of pain and nursing home placement and lower Barthel and EQ-5D scores than patients with normal muscle tone. Early predictive factors for presence of severe spasticity [modified Ashworth scale score (MAS) ≥3] at final follow-up were moderate increase in muscle tone at baseline and/or first follow-up (MAS = 2), low Barthel Index at baseline, hemispasticity, involvement of more than two joints at first follow-up, and paresis at any assessment point. The study helps to identify patients at highest risk for permanent and severe spasticity, and advocates for early treatment in this group

Eftilagimod alpha (a soluble LAG-3 protein) combined with pembrolizumab in second-line metastatic NSCLC refractory to anti–programmed cell death protein 1/programmed death-ligand 1-based therapy: final results from a phase 2 study

Introduction: Eftilagimod alpha (efti), a soluble lymphocyte activation gene-3 protein, triggers antigen-presenting cell and T-cell (CD4+ and CD8+) activation and helps overcome resistance to programmed cell death protein 1 or programmed cell death-ligand 1 (PD-(L)1) inhibitors. We assessed efti plus pembrolizumab in second-line anti–PD-(L)1-refractory metastatic patients with NSCLC. Methods: After confirmed progression on anti-PD-(L)1-based first-line therapy, patients received efti (30 mg subcutaneously every 2 weeks for eight 3-week cycles and then every 3 weeks for up to 54 weeks) plus pembrolizumab (200 mg intravenously every 3 weeks for up to 105 weeks). The primary endpoint was the objective response rate by modified Response Evaluation Criteria in Solid Tumors version 1.1 for immune-based therapies. Secondary endpoints included disease control rate, progression-free survival, overall survival (OS), and tolerability. Exploratory endpoints included tumor growth kinetics and predefined subgroup analyses. Programmed cell death-ligand 1 tumor proportion score was assessed centrally. Results: Thirty-six patients were enrolled from April 2019 to August 2021 using Simon’s two-stage design. Most patients (81.8%) had low or negative (&lt;50%) PD-(L)1 tumor proportion score. First-line therapy was anti–PD-(L)1-based for all patients, combined with chemotherapy for 66.7%. The confirmed objective response and disease control rates were 8.3% and 33.3%. The median progression-free survival was 2.1 months and the median OS was 9.9 months. Patients exhibiting high PD-(L)1 expression or acquired resistance to PD-(L)1 inhibitors revealed superior response and survival outcomes, and OS was closely correlated with disease control. No treatment-emergent adverse event led to permanent discontinuation of study treatment. Conclusions: Efti plus pembrolizumab was well-tolerated and revealed signs of antitumor activity in patients with NSCLC resistant to PD-(L)1 inhibitors, warranting further investigation. Trial registration number: NCT03625323

Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U

Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom