260 research outputs found
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Intersectional Discrimination Is Associated with Housing Instability among Trans Women Living in the San Francisco Bay Area.
Trans women face numerous structural barriers to health due to discrimination. Housing instability is an important structural determinant of poor health outcomes among trans women. The purpose of this study was to determine if experiences of intersectional anti-trans and racial discrimination are associated with poor housing outcomes among trans women in the San Francisco Bay Area. A secondary analysis of baseline data from the Trans *National study (n = 629) at the San Francisco Department of Public Health (2016-2018) was conducted. Multivariable logistic regression was used to analyze the association between discrimination as an ordered categorical variable (zero, one to two, or three or more experiences) and housing status adjusting for age, years lived in the Bay Area, and gender identity. We found that the odds of housing instability increased by 1.25 for every categorical unit increase (1-2, or 3+) in reported experiences of intersectional (both anti-trans and racial) discrimination for trans women (95% CI = 1.01-1.54, p-value < 0.05). Intersectional anti-trans and racial discrimination is associated with increased housing instability among trans women, giving some insight that policies and programs are needed to identify and address racism and anti-trans stigma towards trans women. Efforts to address intersectional discrimination may positively impact housing stability, with potential for ancillary effects on increasing the health and wellness of trans women who face multiple disparities
Freshwater Mussels Exposed to Arsenic and Sulfate Show Contrasting Patterns of Gene Expression
Freshwater mussels of the Clinch and Powell rivers of Virginia in the southeastern United States have been heavily impacted by runoff, leachates, or spills of materials related to coal extraction, processing, and use. Assays quantifying sublethal impacts of such wastes are needed. We assessed gene transcriptional markers in a laboratory study under controlled conditions, focusing upon arsenic (arsenate, As(V)) and sulphate, contaminants related to coal mining and processing. Pheasantshells Actinonaias pectorosa collected from the Clinch River were subjected to a 28-day chronic exposure to control or environmentally relevant concentrations of each compound. We compared gene expression in digestive gland among parasite-free, female pheasantshells among control and contaminant-exposed individuals using the Illumina HiSeq platform. Statistically significant differential expression of particular genes was observed among control mussels and those exposed to either arsenate or sulfate. Chemical stress was as likely to cause under-expression as it was to cause over-expression of particular genes. Arsenate and sulfate induced up- or down-expression of different suites of 50-100 genes. Our results provide proof-of-principle for using RNAseq technology to approach issues of toxicogenomics in freshwater mussels. The candidate markers could be validated for quantitative PCR assays for rapidly assessing single-gene responses to exposure to toxic compounds
Nanoscale integration of single cell biologics discovery processes using optofluidic manipulation and monitoring.
The new and rapid advancement in the complexity of biologics drug discovery has been driven by a deeper understanding of biological systems combined with innovative new therapeutic modalities, paving the way to breakthrough therapies for previously intractable diseases. These exciting times in biomedical innovation require the development of novel technologies to facilitate the sophisticated, multifaceted, high-paced workflows necessary to support modern large molecule drug discovery. A high-level aspiration is a true integration of "lab-on-a-chip" methods that vastly miniaturize cellulmical experiments could transform the speed, cost, and success of multiple workstreams in biologics development. Several microscale bioprocess technologies have been established that incrementally address these needs, yet each is inflexibly designed for a very specific process thus limiting an integrated holistic application. A more fully integrated nanoscale approach that incorporates manipulation, culture, analytics, and traceable digital record keeping of thousands of single cells in a relevant nanoenvironment would be a transformative technology capable of keeping pace with today's rapid and complex drug discovery demands. The recent advent of optical manipulation of cells using light-induced electrokinetics with micro- and nanoscale cell culture is poised to revolutionize both fundamental and applied biological research. In this review, we summarize the current state of the art for optical manipulation techniques and discuss emerging biological applications of this technology. In particular, we focus on promising prospects for drug discovery workflows, including antibody discovery, bioassay development, antibody engineering, and cell line development, which are enabled by the automation and industrialization of an integrated optoelectronic single-cell manipulation and culture platform. Continued development of such platforms will be well positioned to overcome many of the challenges currently associated with fragmented, low-throughput bioprocess workflows in biopharma and life science research
Kink oscillations of flowing threads in solar prominences
Recent observations by Hinode/SOT show that MHD waves and mass flows are
simultaneously present in the fine structure of solar prominences. We
investigate standing kink magnetohydrodynamic (MHD) waves in flowing prominence
threads from a theoretical point of view. We model a prominence fine structure
as a cylindrical magnetic tube embedded in the solar corona with its ends
line-tied in the photosphere. The magnetic cylinder is composed of a region
with dense prominence plasma, which is flowing along the magnetic tube, whereas
the rest of the flux tube is occupied by coronal plasma. We use the WKB
approximation to obtain analytical expressions for the period and the amplitude
of the fundamental mode as functions of the flow velocity. In addition, we
solve the full problem numerically by means of time-dependent simulations. We
find that both the period and the amplitude of the standing MHD waves vary in
time as the prominence thread flows along the magnetic structure. The
fundamental kink mode is a good description for the time-dependent evolution of
the oscillations, and the analytical expressions in the WKB approximation are
in agreement with the full numerical results. The presence of flow modifies the
period of the oscillations with respect to the static case. However, for
realistic flow velocities this effect might fall within the error bars of the
observations. The variation of the amplitude due to the flow leads to apparent
damping or amplification of the oscillations, which could modify the real rate
of attenuation caused by an additional damping mechanism.Comment: Accepted for publication in A&
MicroRNA-124 Regulates STAT3 Expression and Is Down-regulated in Colon Tissues of Pediatric Patients With Ulcerative Colitis
Background & Aims - Altered levels and functions of microRNAs (miRs) have been associated with inflammatory bowel diseases (IBDs), although little is known about their roles in pediatric IBD. We investigated whether colonic mucosal miRs are altered in children with ulcerative colitis (UC). Methods - We used a library of 316 miRs to identify those that regulate phosphorylation of STAT3 in NCM460 human colonocytes incubated with interleukin-6. Levels of miR-124 were measured by real-time PCR analysis of colon biopsies from pediatric and adult patients with UC and patients without IBD (controls), and of HCT-116 colonocytes incubated with 5-aza-2’-deoxycytidine. Methylation of the MIR124 promoter was measured by quantitative methylation-specific PCR. Results - Levels of phosphorylated STAT3 and the genes it regulates (encoding VEGF, BCL2, BCLXL, and MMP9) were increased in pediatric patients with UC, compared to control tissues. Overexpression of miR-124, let-7, miR-125, miR-26, or miR-101 reduced STAT3 phosphorylation by ≥75% in NCM460 cells; miR-124 had the greatest effect. miR-124 was downregulated specifically in colon tissues from pediatric patients with UC and directly targeted STAT3 mRNA. Levels of miR-124 were decreased whereas levels of STAT3 phosphorylation increased in colon tissues from pediatric patients with active UC, compared to those with inactive disease. Furthermore, levels of miR-124 and STAT3 were inversely correlated in mice with experimental colitis. Downregulation of miR-124 in tissues from children with UC was attributed to hypermethylation of its promoter region. Incubation of HCT-116 colonocytes with 5-aza-2’ deoxycytidine upregulated miR-124 and reduced levels of STAT3 mRNA. Conclusions - MiR-124 appears to regulate the expression of STAT3. Reduced levels of miR-124 in colon tissues of children with active UC appear to increase expression and activity of STAT3, which could promote inflammation and pathogenesis of UC in children
Towards automated cancer screening: label-free classification of fixed cell samples using wavelength modulated Raman spectroscopy
This work was supported by the Engineering and Physical Sciences Research Council and Medical Research Council [EP/L016559/1, EP/P030017/1], and CRUK [A18075 Core Award].The ability to provide quantitative, objective and automated pathological analysis would provide enormous benefits for national cancer screening programmes, in terms of both resource reduction and improved patient wellbeing. The move towards molecular pathology through spectroscopic methods shows great promise, but has been restricted by spectral quality, acquisition times and lack of direct clinical application. In this paper, we present the application of wavelength modulated Raman spectroscopy for the automated label- and fluorescence-free classification of fixed squamous epithelial cells in suspension, such as those produced during a cervical smear test. Direct comparison with standard Raman spectroscopy shows marked improvement of sensitivity and specificity when considering both human papillomavirus (sensitivity +12.0%, specificity +5.3%) and transformation status (sensitivity +10.3%, specificity +11.1%). Studies on the impact of intracellular sampling location and storage effects suggest that wavelength modulated Raman spectroscopy is sufficiently robust to be used in fixed cell classification, but requires further investigations of potential sources of molecular variation in order to improve current clinical tools.Publisher PDFPeer reviewe
Selective spatial damping of propagating kink wavesto resonant absorption
There is observational evidence of propagating kink waves driven by photospheric motions. These disturbances, interpreted as kink magnetohydrodynamic (MHD) waves are attenuated as they propagate upwards in the solar corona. In this paper we show that resonant absorption provides a simple explanation to the spatial damping of these waves. Kink MHD waves are studied using a cylindrical model of solar magnetic flux tubes which includes a non-uniform layer at the tube boundary. Assuming that the frequency is real and the longitudinal wavenumber complex, the damping length and damping per wavelength produced by resonant absorption are analytically calculated. The damping length of propagating kink waves due resonant absorption is a monotonically decreasing function of frequency. For kink waves with low frequencies the damping length is exactly inversely proportional to frequency and we denote this as the TGV relation. When moving to high frequencies the TGV relation continues to be an exceptionally good approximation of the actual dependency of the damping length on frequency. This dependency means that resonant absorption is selective as it favours low frequency waves and can efficiently remove high frequency waves from a broad band spectrum of kink waves. It is selective as the damping length is inversely proportional to frequency so that the damping becomes more severe with increasing frequency. This means that radial inhomogeneity can cause solar waveguides to be a natural low-pass filter for broadband disturbances. Hence kink wave trains travelling along, e.g., coronal loops, will have a greater proportion of the high frequency components dissipated lower down in the atmosphere. This could have important consequences with respect to the spatial distribution of wave heating in the solar atmospher
MHD waves in sunspots
The review addresses the spatial frequency morphology of sources of sunspot
oscillations and waves, including their localization, size, oscillation
periods, height localization with the mechanism of cut-off frequency that forms
the observed emission variability. Dynamic of sunspot wave processes, provides
the information about the structure of wave fronts and their time variations,
investigates the oscillation frequency transformation depending on the wave
energy is shown. The initializing solar flares caused by trigger agents like
magnetoacoustic waves, accelerated particle beams, and shocks are discussed.
Special attention is paid to the relation between the flare reconnection
periodic initialization and the dynamics of sunspot slow magnetoacoustic waves.
A short review of theoretical models of sunspot oscillations is provided.Comment: 20 pages, 6 figures, Chapter in AGU Monograph (in press), Review
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Distinguishing surface and bulk electromagnetism via their dynamics in an intrinsic magnetic topological insulator
The indirect exchange interaction between local magnetic moments via surface electrons has been long predicted to bolster the surface ferromagnetism in magnetic topological insulators (MTIs), which facilitates the quantum anomalous Hall effect. This unconventional effect is critical to determining the operating temperatures of future topotronic devices. However, the experimental confirmation of this mechanism remains elusive, especially in intrinsic MTIs. Here, we combine time-resolved photoemission spectroscopy with time-resolved magneto-optical Kerr effect measurements to elucidate the unique electromagnetism at the surface of an intrinsic MTI MnBi2Te4. Theoretical modeling based on 2D Ruderman-Kittel-Kasuya-Yosida interactions captures the initial quenching of a surface-rooted exchange gap within a factor of two but overestimates the bulk demagnetization by one order of magnitude. This mechanism directly explains the sizable gap in the quasi-2D electronic state and the nonzero residual magnetization in even-layer MnBi2Te4. Furthermore, it leads to efficient light-induced demagnetization comparable to state-of-the-art magnetophotonic crystals, promising an effective manipulation of magnetism and topological orders for future topotronics
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