1,254 research outputs found
Mid-Infrared Extinction and its Variation with Galactic Longitude
Based on the data obtained from the Spitzer/GLIPMSE Legacy Program and the
2MASS project, we derive the extinction in the four IRAC bands, [3.6], [4.5],
[5.8] and [8.0] micron, relative to the 2MASS Ks band (at 2.16 micron) for 131
GLIPMSE fields along the Galactic plane within |l|<65 deg, using red giants and
red clump giants as tracers. As a whole, the mean extinction in the IRAC bands
(normalized to the 2MASS Ks band), A_[3.6]/A_Ks=0.63, A_[4.5]/A_Ks=0.57,
A_[5.8]/A_Ks=0.49, A_[8.0]/A_Ks=0.55, exhibits little variation with wavelength
(i.e. the extinction is somewhat flat or gray). This is consistent with
previous studies and agrees with that predicted from the standard interstellar
grain model for R_V=5.5 by Weingartner & Draine (2001). As far as individual
sightline is concerned, however, the wavelength dependence of the mid-infrared
interstellar extinction A_{lambda}/A_Ks varies from one sightline to another,
suggesting that there may not exist a "universal" IR extinction law. We, for
the first time, demonstrate the existence of systematic variations of
extinction with Galactic longitude which appears to correlate with the
locations of spiral arms as well as with the variation of the far infrared
luminosity of interstellar dust.Comment: 37 pages, 9 figures, to be published in Ap
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Autoreactivity and Exceptional CDR Plasticity (but Not Unusual Polyspecificity) Hinder Elicitation of the Anti-HIV Antibody 4E10
The broadly-neutralizing anti-HIV antibody 4E10 recognizes an epitope in the membrane-proximal external region of the HIV envelope protein gp41. Previous attempts to elicit 4E10 by vaccination with envelope-derived or reverse-engineered immunogens have failed. It was presumed that the ontogeny of 4E10-equivalent responses was blocked by inherent autoreactivity and exceptional polyreactivity. We generated 4E10 heavy-chain knock-in mice, which displayed significant B cell dysregulation, consistent with recognition of autoantigen/s by 4E10 and the presumption that tolerance mechanisms may hinder the elicitation of 4E10 or 4E10-equivalent responses. Previously proposed candidate 4E10 autoantigens include the mitochondrial lipid cardiolipin and a nuclear splicing factor, 3B3. However, using carefully-controlled assays, 4E10 bound only weakly to cardiolipin-containing liposomes, but also bound negatively-charged, non-cardiolipin-containing liposomes comparably poorly. 4E10/liposome binding was predominantly mediated by electrostatic interactions rather than presumed hydrophobic interactions. The crystal structure of 4E10 free of bound ligands showed a dramatic restructuring of the combining site, occluding the HIV epitope binding site and revealing profound flexibility, but creating an electropositive pocket consistent with non-specific binding of phospholipid headgroups. These results strongly suggested that antigens other than cardiolipin mediate 4E10 autoreactivity. Using a synthetic peptide library spanning the human proteome, we determined that 4E10 displays limited and focused, but unexceptional, polyspecificity. We also identified a novel autoepitope shared by three ER-resident inositol trisphosphate receptors, validated through binding studies and immunohistochemistry. Tissue staining with 4E10 demonstrated reactivity consistent with the type 1 inositol trisphosphate receptor as the most likely candidate autoantigen, but is inconsistent with splicing factor 3B3. These results demonstrate that 4E10 recognition of liposomes competes with MPER recognition and that HIV antigen and autoepitope recognition may be distinct enough to permit eliciting 4E10-like antibodies, evading autoimmunity through directed engineering. However, 4E10 combining site flexibility, exceptional for a highly-matured antibody, may preclude eliciting 4E10 by conventional immunization strategies
Repeat lumbar punctures in infants with meningitis in the neonatal intensive care unit
The purpose of this study is to examine the results of repeat lumbar puncture in infants with initial positive cerebrospinal fluid (CSF) cultures in order to determine the clinical characteristics and outcomes of infants with repeat positive cultures
Model of the Quark Mixing Matrix
The structure of the Cabibbo-Kobayashi-Maskawa (CKM) matrix is analyzed from
the standpoint of a composite model. A model is constructed with three families
of quarks, by taking tensor products of sufficient numbers of spin-1/2
representations and imagining the dominant terms in the mass matrix to arise
from spin-spin interactions. Generic results then obtained include the familiar
relation , and a less frequently
seen relation . The magnitudes of
and come out naturally to be of the right order. The phase in
the CKM matrix can be put in by hand, but its origin remains obscure.Comment: Presented by Mihir P. Worah at DPF 92 Meeting, Fermilab, November,
1992. 3 pages, LaTeX fil
Is Persistent Motor or Vocal Tic Disorder a Milder Form of Tourette Syndrome?
BACKGROUND: Persistent motor or vocal tic disorder (PMVT) has been hypothesized to be a forme fruste of Tourette syndrome (TS). Although the primary diagnostic criterion for PMVT (presence of motor or vocal tics, but not both) is clear, less is known about its clinical presentation. OBJECTIVE: The goals of this study were to compare the prevalence and number of comorbid psychiatric disorders, tic severity, age at tic onset, and family history for TS and PMVT. METHODS: We analyzed data from two independent cohorts using generalized linear equations and confirmed our findings using metaâanalyses, incorporating data from previously published literature. RESULTS: Rates of obsessiveâcompulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) were lower in PMVT than in TS in all analyses. Other psychiatric comorbidities occurred with similar frequencies in PMVT and TS in both cohorts, although metaâanalyses suggested lower rates of most psychiatric disorders in PMVT compared with TS. ADHD and OCD increased the odds of comorbid mood, anxiety, substance use, and disruptive behaviors, and accounted for observed differences between PMVT and TS. Age of tic onset was approximately 2âyears later, and tic severity was lower in PMVT than in TS. Firstâdegree relatives had elevated rates of TS, PMVT, OCD, and ADHD compared with population prevalences, with rates of TS equal to or greater than PMVT rates. CONCLUSIONS: Our findings support the hypothesis that PMVT and TS occur along a clinical spectrum in which TS is a more severe and PMVT a less severe manifestation of a continuous neurodevelopmental tic spectrum disorder. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Societ
The production and consumption activities relating to the celebrity artist
This paper considers the impact of the celebrity artist on the associated production and consumption activities. It also considers the role which entrepreneurial marketing plays in helping to create the celebrity artist aura. The artist Thomas Kinkade is used to illustrate how this occurs in practice. Here, authenticity and nostalgia dimensions are also influential factors. Underpinning these relationships are the roles played out by the media, including communication of celebrity artist identity, and the catalysing of its commodification within the celebrity artist brandscape. An enduring celebrity brand results due to the market creation activities of the celebrity artist. A conceptual model is developed which synthesises the factors behind the production and consumption of the celebrity artist which can stimulate further research. This paper provides innovative insight into the world of the celebrity artist by interrogating the market making and shaping devices behind successful production and consumption practices
Relational persons and relational processes: developing the notion of relationality for the sociology of personal life
The concept of relationality has recently found widespread favour in British sociology, particularly in the emergent sub-field of the sociology of personal life, which is characterised by its attachment to the concept. However, this ârelational turnâ is under-theorized and pays little attention to the substantial history of relational thinking across the human sciences. This paper argues that the notion of relationality in the sociology of personal life might be strengthened by an exploration of the conceptualization of the relational person and relational processes offered by three bodies of literature: the process oriented thinking of American pragmatism, specifically of Mead and Emirbayer; the figurational sociology of Elias; and psychoanalysis, particularly the object relations tradition, contemporary relational psychoanalysis and Ettingerâs notion of transubjectivity. The paper attends particularly to the processes involved in the individuality, agentic reflexivity and affective dimensions of the relational person
Lifetime body size and reproductive factors: comparisons of data recorded prospectively with self reports in middle age
<p>Abstract</p> <p>Background</p> <p>Data on lifetime exposures are often self-reported in epidemiologic studies, sometimes many years after the relevant age. Validity of self-reported data is usually inferred from their agreement with measured values, but few studies directly quantify the likely effects of reporting errors in body size and reproductive history variables on estimates of disease-exposure associations.</p> <p>Methods</p> <p>The MRC National Survey of Health and Development (NSHD) and the Million Women Study (MWS) are UK population-based prospective cohorts. The NSHD recruited participants at birth in 1946 and has followed them at regular intervals since then, whereas the MWS recruited women in middle age. For 541 women who were participants in both studies, we used statistical measures of association and agreement to compare self-reported MWS data on body size throughout life and reproductive history, obtained in middle age, to NSHD data measured or reported close to the relevant ages. Likely attenuation of estimates of linear disease-exposure associations due to the combined effects of random and systematic errors was quantified using regression dilution ratios (RDRs).</p> <p>Results</p> <p>Data from the two studies were very strongly correlated for current height, weight and body mass index, and age at menopause (Pearson r = 0.91-0.95), strongly correlated for birth weight, parental heights, current waist and hip circumferences and waist-to-height ratio (r = 0.67-0.80), and moderately correlated for age at menarche and waist-to-hip ratio (r = 0.52-0.57). Self-reported categorical body size and clothes size data for various ages were moderately to strongly associated with anthropometry collected at the relevant times (Spearman correlations 0.51-0.79). Overall agreement between the studies was also good for most quantitative variables, although all exhibited both random and systematic reporting error. RDRs ranged from 0.66 to 0.86 for most variables (slight to moderate attenuation), except weight and body mass index (1.02 and 1.04, respectively; little or no attenuation), and age at menarche, birth weight and waist-to-hip ratio (0.44, 0.59 and 0.50, respectively; substantial attenuation).</p> <p>Conclusions</p> <p>This study provides some evidence that self-reported data on certain anthropometric and reproductive factors may be adequate for describing disease-exposure associations in large epidemiological studies, provided that the effects of reporting errors are quantified and the results are interpreted with caution.</p
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