347 research outputs found

    Development of a thiol-reactive fluorescent probe for the identification of human spermatozoa

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    Current methods of identifying semen include preliminary methods such as an alternate light source (ALS) and color tests which test for the presence of acid phosphatase (AP). Confirmatory methods for identifying semen include the microscopic identification of spermatozoa which typically use staining methods such as the Christmas Tree Stain (KPIC) or hematoxylin and eosin stain (H&E). Other methods include immunoassay cards that test for the components of semen such as prostate specific antigen (PSA) and semenogelin (Sg). One common fluorescent staining method used to identify the presence of spermatozoa is SPERM HY-LITERTM which uses an anti-human sperm-specific mouse monoclonal antibody coupled to an AlexaFluor 488 dye. This causes the entire head of the sperm cell to fluoresce when a FITC filter is used. It also utilizes a 4,6-diamidino-2- phenylindole (DAPI) fluorescent dye that stains all cell nuclei non-specifically. This allows the analyst to easily identify whether sperm is present in the sample. A drawback of the antibody labeling procedure is that there are many washing and transfer steps that can lead to sample loss; thus a need for a new, optimized staining method exists. During spermiogenesis, protamines replace histones to further condense the DNA of the sperm nucleus. Humans express two proamines, protamine 1 (P1) and protamine 2 (P2). The protamines contain an arginine-rich core as well as cysteine residues. The high levels of arginine create a net positive charge that allows for stronger binding to DNA. The cysteine residues allow for the formation of inter and intra-protamine disulfide bonds which allow for the chromatin compaction. If the disulfide bonds found in protamines can be reduced to produce free thiols, a thiol-reactive probe can bind and label the protamines in the sperm nucleus. Reduction of the disulfide bonds can be performed by use of reagents such as dithiothreitol (DTT) or tris-(2-carboxyethyl)phosphine (TCEP). From the literature on thiol-reactive probes, it is suggested that TCEP be used as a reducing agent due to its structure. DTT contains thiol groups and when removed from the sample, thiol groups may be oxidized back into disulfide bond. In addition, TCEP is more stable than DTT at a higher pH and higher temperatures. Once disulfide bonds have been reduced, a thiol-reactive probe may be introduced. There are many different types of probes that may be used. Maleimides are commonly used for thiol modification and quantitation. When the compound encounters a thiol group, the thiol group is added across the double bond, yielding a thioether. The reagent used is N-7-dimethylamino-4-methylcoumarin-3-yl)maleimide (DACM). It absorbs light at 376 nm and emits light at 476 nm, producing a blue fluorescence. The dye is nonfluorescent until it reacts with a thiol group. In this research, both sperm and epithelial cells were added to the slides in order to develop a novel staining procedure. The initial protocol used TCEP to break the disulfide bonds followed by DACM to bind free thiol groups. Sodium dodecyl sulfate (SDS) was then added to the protocol to lyse cells. DTT was tested for use as a reducing agent as well. The purpose of establishing this protocol was to design a procedure for rapid labeling of sperm that does not require antibody labeling. In the antibody labeling procedure, there are many washing and transfer steps. The proposed method may limit the number of procedural steps resulting in less loss of biological material. It can also help to limit the time-consuming methods of the current staining techniques, such as KPIC and H&E

    Violence against women in sex work and HIV risk implications differ qualitatively by perpetrator.

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    PMC3852292BACKGROUND: Physical and sexual violence heighten STI/HIV risk for women in sex work. Against this backdrop, we describe the nature of abuse against women in sex work, and its STI/HIV implications, across perpetrators. METHODS: Adult women involved in sex work (n = 35) in Baltimore, MD participated in an in-depth interview and brief survey. RESULTS: Physical and sexual violence were prevalent, with 43% reporting past-month abuse. Clients were the primary perpetrators; their violence was severe, compromised women's condom and sexual negotiation, and included forced and coerced anal intercourse. Sex work was a factor in intimate partner violence. Police abuse was largely an exploitation of power imbalances for coerced sex. CONCLUSIONS: Findings affirm the need to address physical and sexual violence, particularly that perpetrated by clients, as a social determinant of health for women in sex work, as well as a threat to safety and wellbeing, and a contextual barrier to HIV risk reduction.JH Libraries Open Access Fun

    GWAS Meta-Analysis of Suicide Attempt: Identification of 12 Genome-Wide Significant Loci and Implication of Genetic Risks for Specific Health Factors

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    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

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    Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

    Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

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    Search for anomalous production of events with three or more leptons in pp collisions at √s = 8TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.A search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5fb-1 of proton-proton collisions with center-of-mass energy s=8TeV, was collected by the CMS experiment at the LHC during 2012. The data are divided into exclusive categories based on the number of leptons and their flavor, the presence or absence of an opposite-sign, same-flavor lepton pair (OSSF), the invariant mass of the OSSF pair, the presence or absence of a tagged bottom-quark jet, the number of identified hadronically decaying τ leptons, and the magnitude of the missing transverse energy and of the scalar sum of jet transverse momenta. The numbers of observed events are found to be consistent with the expected numbers from standard model processes, and limits are placed on new-physics scenarios that yield multilepton final states. In particular, scenarios that predict Higgs boson production in the context of supersymmetric decay chains are examined. We also place a 95% confidence level upper limit of 1.3% on the branching fraction for the decay of a top quark to a charm quark and a Higgs boson (t→cH), which translates to a bound on the left- and right-handed top-charm flavor-violating Higgs Yukawa couplings, λtcH and λctH, respectively, of |λtcH|2+|λctH|2<0.21
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