948 research outputs found
Substance Use Disorders, Violence, Mental Health, and HIV: Differentiating a Syndemic Factor by Gender and Sexuality
This paper measures syndemic substance use disorder, violence, and mental health and compares the syndemic among HIV-infected heterosexual men, heterosexual women, and men who have sex with men (MSM). Data were from a sample of high needs substance-using, HIV-infected people in South Florida between 2010 and 2012 (n = 481). We used confirmatory factor analysis to measure a syndemic latent variable and applied measurement invariance models to identify group differences in the data structure of syndemic co-morbidities among heterosexual men, heterosexual women, and MSM. We found that variables used to measure the syndemic fit each sub-group, supporting that substance use disorder, violence, and mental health coincide in HIV-infected individuals. Heterosexual men and MSM demonstrated similar syndemic latent variable factor loadings, but significantly different item intercepts, indicating that heterosexual men had larger mean values on substance use disorder, anxiety, and depression than MSM. Heterosexual men and heterosexual women demonstrated significantly different syndemic variable factor loadings, indicating that anxiety and depression contribute more (and substance use contributes less) to the syndemic in heterosexual men compared to heterosexual women. MSM and heterosexual women demonstrated similar syndemic latent variable factor loadings and intercepts, but had significantly different factor residual variances indicating more variance in violent victimization and depression for MSM and more variance in stress for heterosexual women than what is captured by the observed syndemic indicators. Furthermore, heterosexual women had a larger syndemic factor mean than MSM, indicating that the syndemic burden is greater among heterosexual women than MSM. Our findings support that measurement invariance can elucidate differences in the syndemic to tailor interventions to sub-group needs
A randomized, open-label study of the efficacy and safety of AZD4547 monotherapy versus paclitaxel for the treatment of advanced gastric adenocarcinoma with FGFR2 polysomy or gene amplification
Background:Approximately 5%-10% of gastric cancers have a fibroblast growth factor receptor-2 (FGFR2) gene amplification. AZD4547 is a selective FGFR-1, 2, 3 tyrosine kinase inhibitor with potent preclinical activity in FGFR2 amplified gastric adenocarcinoma SNU16 and SGC083 xenograft models. The randomized phase II SHINE study (NCT01457846) investigated whether AZD4547 improves clinical outcome versus paclitaxel as second-line treatment in patients with advanced gastric adenocarcinoma displaying FGFR2 polysomy or gene amplification detected by fluorescence in situ hybridization. Patients and methods:Patients were randomized 3:2 (FGFR2 gene amplification) or 1:1 (FGFR2 polysomy) to AZD4547 or paclitaxel. Patients received AZD4547 80 mg twice daily, orally, on a 2 weeks on/1 week off schedule of a 21-day cycle or intravenous paclitaxel 80 mg/m2 administered weekly on days 1, 8, and 15 of a 28-day cycle. The primary end point was progression-free survival (PFS). Safety outcomes were assessed and an exploratory biomarker analysis was undertaken. Results:Of 71 patients randomized (AZD4547 n = 41, paclitaxel n = 30), 67 received study treatment (AZD4547 n = 40, paclitaxel n = 27). Among all randomized patients, median PFS was 1.8 months with AZD4547 and 3.5 months with paclitaxel (one-sided P = 0.9581); median follow-up duration for PFS was 1.77 and 2.12 months, respectively. The incidence of adverse events was similar in both treatment arms. Exploratory biomarker analyses revealed marked intratumor heterogeneity of FGFR2 amplification and poor concordance between amplification/polysomy and FGFR2 mRNA expression. Conclusions:AZD4547 did not significantly improve PFS versus paclitaxel in gastric cancer FGFR2 amplification/polysomy patients. Considerable intratumor heterogeneity for FGFR2 gene amplification and poor concordance between FGFR2 amplification/polysomy and FGFR2 expression indicates the need for alternative predictive biomarker testing. AZD4547 was generally well tolerated
The surprising Far-UV spectrum of the polar BY Camelopardalis
We report on the first far-UV observations of the asynchronous polar BY Cam
made by the Far-Ultraviolet Spectroscopic Explorer (FUSE). The source is known
to exhibit the most extreme NV/CIV emission resonance line ratio observed among
polars. The FUSE observations reveal a OVI resonance line weaker than in the
prototype of polars, AM Her, with the absence of a detectable narrow component.
The OVI broad line is detected with an equivalent width of the same order as in
AM Her, the blueward doublet component is clearly present but the redward
component is strongly affected by H2 absorption. The presence of a strong NIII
line and weak CIII lines also confirms the peculiar CNO line flux. We compare
the resonance CNO line intensities with the predictions of the CLOUDY plasma
code coupled to a geometrical model of the accretion column. Varying the
temperature and/or intensity of the ionising spectrum is unable to reproduce
the observed broad line ratios. A solution is obtained by significantly
altering the element abundances with a strong depletion of C, overabundance of
N and a weak underabundance of O. This confirms previous suggestions of
non-solar abundances which may result from redistribution in the accreted
material following nova outbursts and/or the secondary nuclear evolution. A
very significant H2 absorption is observed in front of the source, a possible
indication for either the existence of a dense interstellar cloud or of
circumstellar material.Comment: 6 pages, 4 Postscript figures, accepted by Astronomy and
Astrophysics, uses aa.st
Optical Excitations and Field Enhancement in Short Graphene Nanoribbons
The optical excitations of elongated graphene nanoflakes of finite length are
investigated theoretically through quantum chemistry semi-empirical approaches.
The spectra and the resulting dipole fields are analyzed, accounting in full
atomistic details for quantum confinement effects, which are crucial in the
nanoscale regime. We find that the optical spectra of these nanostructures are
dominated at low energy by excitations with strong intensity, comprised of
characteristic coherent combinations of a few single-particle transitions with
comparable weight. They give rise to stationary collective oscillations of the
photoexcited carrier density extending throughout the flake, and to a strong
dipole and field enhancement. This behavior is robust with respect to width and
length variations, thus ensuring tunability in a large frequency range. The
implications for nanoantennas and other nanoplasmonic applications are
discussed for realistic geometries
Human Wavelength Discrimination of Monochromatic Light Explained by Optimal Wavelength Decoding of Light of Unknown Intensity
We show that human ability to discriminate the wavelength of monochromatic light
can be understood as maximum likelihood decoding of the cone absorptions, with a
signal processing efficiency that is independent of the wavelength. This work is
built on the framework of ideal observer analysis of visual discrimination used
in many previous works. A distinctive aspect of our work is that we highlight a
perceptual confound that observers should confuse a change in input light
wavelength with a change in input intensity. Hence a simple ideal observer model
which assumes that an observer has a full knowledge of input intensity should
over-estimate human ability in discriminating wavelengths of two inputs of
unequal intensity. This confound also makes it difficult to consistently measure
human ability in wavelength discrimination by asking observers to distinguish
two input colors while matching their brightness. We argue that the best
experimental method for reliable measurement of discrimination thresholds is the
one of Pokorny and Smith, in which observers only need to distinguish two
inputs, regardless of whether they differ in hue or brightness. We
mathematically formulate wavelength discrimination under this
wavelength-intensity confound and show a good agreement between our theoretical
prediction and the behavioral data. Our analysis explains why the discrimination
threshold varies with the input wavelength, and shows how sensitively the
threshold depends on the relative densities of the three types of cones in the
retina (and in particular predict discriminations in dichromats). Our
mathematical formulation and solution can be applied to general problems of
sensory discrimination when there is a perceptual confound from other sensory
feature dimensions
ARCTIC: Durvalumab + tremelimumab and durvalumab monotherapy vs SoC in ≥ 3L advanced NSCLC treatment
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Risk factors for presentation to hospital with severe anaemia in Tanzanian children: a case-control study.
In malaria endemic areas anaemia is a usually silent condition that nevertheless places a considerable burden on health services. Cases of severe anaemia often require hospitalization and blood transfusions. The objective of this study was to assess risk factors for admission with anaemia to facilitate the design of anaemia control programmes. We conducted a prospective case-control study of children aged 2-59 months admitted to a district hospital in southern Tanzania. There were 216 cases of severe anaemia [packed cell volume (PCV) < 25%] and 234 age-matched controls (PCV > or = 25%). Most cases [55.6% (n = 120)] were < 1 year of age. Anaemia was significantly associated with the educational level of parents, type of accommodation, health-seeking behaviour, the child's nutritional status and recent and current medical history. Of these, the single most important factor was Plasmodium falciparum parasitaemia [OR 4.3, 95% confidence interval (CI) 2.9-6.5, P < 0.001]. Multivariate analysis showed that increased recent health expenditure [OR 2.2 (95% CI 1.3-3.9), P = 0.005], malnutrition [OR 2.4 (95%CI 1.3-4.3), P < 0.001], living > 10 km from the hospital [OR 3.0 (95% CI 1.9-4.9), P < 0.001], a history of previous blood transfusion [OR 3.8 (95% CI 1.7-9.1), P < 0.001] and P. falciparum parasitaemia [OR 9.5 (95% CI 4.3-21.3), P < 0.001] were independently related to risk of being admitted with anaemia. These findings are considered in terms of the pathophysiological pathway leading to anaemia. The concentration of anaemia in infants and problems of access to health services and adequate case management underline the need for targeted preventive strategies for anaemia control
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