227 research outputs found

    MOBSTER – III. HD 62658: a magnetic Bp star in an eclipsing binary with a non-magnetic ‘identical twin’

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    HD 62658 (B9p V) is a little-studied chemically peculiar star. Light curves obtained by the Kilodegree Extremely Little Telescope (KELT) and Transiting Exoplanet Survey Satellite (TESS) show clear eclipses with a period of about 4.75 d, as well as out-of-eclipse brightness modulation with the same 4.75 d period, consistent with synchronized rotational modulation of surface chemical spots. High-resolution ESPaDOnS circular spectropolarimetry shows a clear Zeeman signature in the line profile of the primary; there is no indication of a magnetic field in the secondary. PHOEBE modelling of the light curve and radial velocities indicates that the two components have almost identical masses of about 3 M_⊙. The primary’s longitudinal magnetic field〈B_z〉 varies between about +100 and −250 G, suggesting a surface magnetic dipole strength B_d = 850 G. Bayesian analysis of the Stokes V profiles indicates B_d = 650 G for the primary and B_d < 110 G for the secondary. The primary’s line profiles are highly variable, consistent with the hypothesis that the out-of-eclipse brightness modulation is a consequence of rotational modulation of that star’s chemical spots. We also detect a residual signal in the light curve after removal of the orbital and rotational modulations, which might be pulsational in origin; this could be consistent with the weak line profile variability of the secondary. This system represents an excellent opportunity to examine the consequences of magnetic fields for stellar structure via comparison of two stars that are essentially identical with the exception that one is magnetic. The existence of such a system furthermore suggests that purely environmental explanations for the origin of fossil magnetic fields are incomplete

    Lentiviral Vector Delivery of Human Interleukin-7 (hIL-7) to Human Immune System (HIS) Mice Expands T Lymphocyte Populations

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    Genetically modified mice carrying engrafted human tissues provide useful models to study human cell biology in physiologically relevant contexts. However, there remain several obstacles limiting the compatibility of human cells within their mouse hosts. Among these is inadequate cross-reactvitiy between certain mouse cytokines and human cellular receptors, depriving the graft of important survival and growth signals. To circumvent this problem, we utilized a lentivirus-based delivery system to express physiologically relevant levels of human interleukin-7 (hIL-7) in Rag2-/-γc-/- mice following a single intravenous injection. hIL-7 promoted homeostatic proliferation of both adoptively transferred and endogenously generated T-cells in Rag2-/-γc-/- Human Immune System (HIS) mice. Interestingly, we found that hIL-7 increased T lymphocyte numbers in the spleens of HIV infected HIS mice without affecting viral load. Taken together, our study unveils a versatile approach to deliver human cytokines to HIS mice, to both improve engraftment and determine the impact of cytokines on human diseases

    Factors associated with cognitive impairment and cognitive concerns in patients with metastatic non-small cell lung cancer

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    BACKGROUND: Knowledge regarding cognitive problems in metastatic non-small cell lung cancer (mNSCLC) is limited. Such problems may include both patient-reported cognitive concerns and demonstrable cognitive impairment. Greater understanding of these outcomes is needed to inform rehabilitation strategies for these difficulties. We aimed to identify the frequency of cognitive problems and associated factors in patients with mNSCLC. METHODS: In this cross-sectional study, adults with mNSCLC completed validated neuropsychological tests and self-report questionnaires measuring cognitive concerns, neurobehavioral concerns, depression, demoralization, illness intrusiveness, self-esteem, and physical symptoms. Cognitive impairment (performance based) was defined according to International Cancer and Cognition Task Force criteria. Clinically significant cognitive concerns were defined by a score ≥1.5 SD below the normative mean on the Functional Assessment of Cancer Therapy-Cognitive Function Perceived Cognitive Impairment (FACT-Cog PCI). Univariate and multivariate logistic regression analyses were performed to identify associated factors. RESULTS: Of 238 patients approached, 77 participated (median age: 62 years; range: 37-82). Brain metastases were present in 41 patients (53%), and 23 (29%) received cranial irradiation. Cognitive impairment and cognitive concerns were present in 31 (40%) and 20 patients (26%), respectively. Cognitive impairment and cognitive concerns co-occurred in 10 patients (13%), but their severity was unrelated. Cognitive impairment was associated with cranial irradiation (odds ratio [OR] = 2.89; P = .04), whereas cognitive concerns were associated with greater illness intrusiveness (OR = 1.04; P = .03) and lower self-esteem (OR = 0.86; P = .03). CONCLUSIONS: Cognitive impairment and cognitive concerns are both common in patients with mNSCLC but are not necessarily related, and their risk factors differ. The association of illness intrusiveness and self-esteem with cognitive concerns can inform therapeutic interventions in this population

    Towards controlling the solid state valence tautomeric interconversion character by solvation

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    Crystals of [Co<i>(diox)</i><sub>2</sub>­(4-NO<sub>2</sub>-py)<sub>2</sub>] (<b>1</b>) and [Co<i>(diox)</i><sub>2</sub>­(4-CN-py)<sub>2</sub>] (<b>2</b>) where <i>diox</i> are the <i>o</i>-dioxolene 3,5-di-<i>t</i>-butylsemiquinonate (SQ<sup>•–</sup>) and/or 3,5-di-<i>t</i>-butylcatecholate (Cat<sup>2–</sup>) ions, 4-NO<sub>2</sub>-py is 4-nitro-pyridine, 4-CN-py is 4-cyano-pyridine, are among the few known crystals presenting both thermally induced and photoinduced <i>ls</i>-[M<sup>+3</sup>(SQ<sup>•–</sup>)­(Cat<sup>2–</sup>)] ↔ <i>hs</i>-[M<sup>2+</sup>(SQ<sup>•–</sup>)<sub>2</sub>] valence tautomeric interconversion (VTI). In <b>2</b>, the thermal-induced VTI is cooperative, characterizing an abrupt conversion, and in <b>1</b> it is noncooperative. In this work, crystals of [Co<i>(diox)</i><sub>2</sub>­(4-NO<sub>2</sub>-py)<sub>2</sub>]­·benzene (<b>1BZ</b>), [Co<i>(diox)</i><sub>2</sub>­(4-NO<sub>2</sub>-py)<sub>2</sub>]­·toluene (<b>1TL</b>), [Co<i>(diox)</i><sub>2</sub>­(4-CN-py)<sub>2</sub>]­·benzene (<b>2BZ</b>), and [Co<i>(diox)</i><sub>2</sub>­(4-CN-py)<sub>2</sub>]­·toluene (<b>2TL</b>) have been prepared and analyzed by single crystal X-ray diffraction in order to investigate how solvation modulates thermally induced VTI. Crystallographic data were also successfully used together with the two-state equilibrium equation to estimate Δ<i>H</i>° and Δ<i>S</i>° VTI thermodynamic parameters. The solvate crystals, like the nonsolvated ones, present essentially reversible thermally induced VTI. The <b>1TL</b> crystal presents the same monoclinic symmetry and the same intermolecular hydrogen-bonded network of <b>1</b>, and both present a noncooperative thermal-induced VTI. The <b>1BZ</b> crystal has triclinic symmetry and presents a cooperative VTI with a thermal hysteresis of ∼30 K. In contrast to <b>2</b>, thermally induced VTI in <b>2BZ</b> and <b>2TL</b> is noncooperative despite the fact that <b>2</b>, <b>2BZ</b>, and <b>2TL</b> crystals exhibit the same monoclinic symmetry and the same intermolecular hydrogen-bonded network. In <b>2BZ</b> and <b>2TL</b> benzene and toluene molecules as well as the <i>t</i>-butyl groups of the <i>o</i>-dioxolene molecules convert gradually from being dynamically disordered at about 300 K to a static disorder state below 150 K. The layer separation distance of interacting [Co<i>(diox)</i><sub>2</sub>­(4-X-py)<sub>2</sub>], X = CN and NO<sub>2</sub>, molecules in all solvate crystals is ∼15 Å, whereas in <b>2</b>, which presents cooperative VTI, it is ∼12 Å. An order–disorder component might account for the stabilization of the metastable <i>hs</i>-Co<sup>2+</sup> state in <b>2BZ</b> and in <b>2TL</b>, but no disorder was found in the <b>1TL</b> crystals. Therefore, the lack of cooperativity in the thermally induced VTI in these crystals seems to be due to the large distance between the layers of interacting molecules. Cooperativity in the VTI of <b>1BZ</b> crystal is likely to be related with the unique molecular bond scheme network that connects neighboring active [Co<i>(diox)</i><sub>2</sub>­(4-NO<sub>2</sub>-py)<sub>2</sub>] molecules through the <i>o</i>-dioxolene oxygen atoms bonded directly to the Co ion

    Hard X-ray-Induced Valence Tautomeric Interconversion in Cobalt-o-Dioxolene Complexes

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    Valence tautomeric interconversion (VTI) is a reversible process occurring in metal complexes in which an intramolecular metal–ligand electron transfer is accompanied by a change of metal ion spin state, creating two switchable electronic states (redox isomers). Herein, we describe the low-temperature, 30–100 K, single-crystal study of the [Co(diox)2(4-CN-py)2]·benzene complex (1) (diox = 3,5-di-t-butylsemiquinonate (SQ•-) and/or 3,5-di-t-butylcatecholate (Cat2–) radical; 4-CN-py = 4-cyano-pyridine) using hard synchrotron X-ray radiation with different intensities. We demonstrate for the first time that hard X-rays can induce VTI, and that the interconversion molar fraction is dependent on both intensity and exposure time. This in turn shows that X-rays, as a probe, might be altering the very nature of many structures under investigation at low temperatures, and consequently their properties. Our findings add new perspectives to VTI studies and might be of significant interest to the entire community investigating photoresponsive complexes

    Benefiting From Misfortune: When Harmless Actions Are Judged to Be Morally Blameworthy

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    Dominant theories of moral blame require an individual to have caused or intended harm. However, the current four studies demonstrate cases where no harm is caused or intended, yet individuals are nonetheless deemed worthy of blame. Specifically, individuals are judged to be blameworthy when they engage in actions that enable them to benefit from another’s misfortune (e.g., betting that a company’s stock will decline or that a natural disaster will occur). Evidence is presented suggesting that perceptions of the actor’s wicked desires are responsible for this phenomenon. It is argued that these results are consistent with a growing literature demonstrating that moral judgments are often the product of evaluations of character in addition to evaluations of acts

    Abundance of SSR Motifs and Development of Candidate Polymorphic SSR Markers (BARCSOYSSR_1.0) in Soybean

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    Simple sequence repeat (SSR) genetic markers, also referred to as microsatellites, function in map-based cloning and for marker-assisted selection in plant breeding. The objectives of this study were to determine the abundance of SSRs in the soybean genome and to develop and test soybean SSR markers to create a database of locus-specific markers with a high likelihood of polymorphism. A total of 210,990 SSRs with di-, tri-, and tetranucleotide repeats of five or more were identified in the soybean whole genome sequence (WGS) which included 61,458 SSRs consisting of repeat units of di- (≥10), tri- (≥8), and tetranucleotide (≥7). Among the 61,458 SSRs, (AT)n, (ATT)n and (AAAT)n were the most abundant motifs among di-, tri-, and tetranucleotide SSRs, respectively. After screening for a number of factors including locus-specificity using e-PCR, a soybean SSR database (BARCSOYSSR_1.0) with the genome position and primer sequences for 33,065 SSRs was created. To examine the likelihood that primers in the database would function to amplify locus-specific polymorphic products, 1034 primer sets were evaluated by amplifying DNAs of seven diverse Glycine max (L.) Merr. and one wild soybean (Glycine soja Siebold & Zucc.) genotypes. A total of 978 (94.6%) of the primer sets amplified a single polymerase chain reaction (PCR) product and 798 (77.2%) amplified polymorphic amplicons as determined by 4.5% agarose gel electrophoresis. The BARCSOYSSR1.0 SSR markers can be found in Soy- Base (http://soybase.org; verified 21 June 2010) the USDA-ARS Soybean Genome Database
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