Heat stress reduces cow milk yield and results in a significant economic loss for the dairy industry. During lactation, heat stress lowers milk production by 25 to 40% with half of the decrease in ...milk synthesis resulting from the reduced feed intake. In vitro studies indicate that primary bovine mammary epithelial cells display greater rates of programmed cell death when exposed to high ambient temperatures, which may lead to a decrease in the total number of mammary epithelial cells in the mammary gland, partially explaining the lower milk production of lactating cows under heat stress. The function of mammary cells is also altered by heat stress. In response to heat stress, mammary cells display higher gene expression of heat shock proteins, indicating a need for cytoprotection from protein aggregation and degradation. Further, heat stress results in increased gene expression without altering protein expression of mammary epithelial cell junction proteins, and does not substantially influence the integrity of mammary epithelium. These data suggest that the mammary gland strives to maintain cell-to-cell junction integrity by synthesizing more proteins to compensate for protein losses induced by heat stress. During the dry period, heat stress negatively affects mammary gland development by reducing mammary cell proliferation before parturition, resulting in a dramatic decrease in milk production in the subsequent lactation. In addition to mammary growth, the mammary gland of the heat-stressed dry cow has reduced protein expression of autophagic proteins in the early dry period, suggesting heat stress influences mammary involution. Emerging evidence also indicates that heifers born to cows that experience late-gestation heat stress have lower milk yield during their first lactation, implying that the maternal environment may alter mammary gland development of the offspring. It is not clear if this is due to a direct epigenetic modification of prenatal mammary gland development by maternal heat stress. More research is needed to elucidate the effect of heat stress on mammary gland development and function.
Pseudomonas aeruginosa bloodstream infections (PA-BSIs) are a serious disease and a therapeutic challenge due to increasing resistance to carbapenems. Our objectives were to describe the prevalence ...and risk factors associated with carbapenem resistance (CR) and mortality in children with PA-BSI.
A retrospective, multi-centre study was carried out, including patients aged <20 years with PA-BSI in four tertiary hospitals in Madrid (Spain) during 2010–2020. Risk factors for CR PA-BSIs and 30-day mortality were evaluated in a multi-variable logistic regression model.
In total, 151 patients with PA-BSI were included, with a median age of 29 months (interquartile range: 3.5–87.1). Forty-five (29.8%) cases were CR, 9.9% multi-drug resistant and 6.6% extensively drug resistant. The prevalence of CR remained stable throughout the study period, with 26.7% (12/45) of CR mediated by VIM-type carbapenemase. Patients with BSIs produced by CR-PA were more likely to receive inappropriate empiric treatment (53.3% vs 5.7%, P<0.001) and to have been previously colonized by CR-PA (8.9% vs 0%, P=0.002) than BSIs caused by carbapenem-susceptible P. aeruginosa. CR was associated with carbapenem treatment in the previous month (adjusted odds ratio (aOR) 11.15) and solid organ transplantation (aOR 7.64). The 30-day mortality was 23.2%, which was associated with mechanical ventilation (aOR 4.24), sepsis (aOR 5.72), inappropriate empiric antibiotic therapy (aOR 5.86), and source control as a protective factor (aOR 0.16).
This study shows a concerning prevalence of CR in children with PA-BSIs, leading to high mortality. Inappropriate empiric treatment and sepsis were associated with mortality. The high prevalence of CR with an increased risk of inappropriate empiric treatment should be closely monitored.
Recent reviews conclude that aphasia intervention is effective. However, replication and implementation require detailed reporting of intervention is and a specification of participant profiles. To ...date, reviews concentrate more on efficacy than on intervention reporting quality.
The aim of this project is to review the descriptions of aphasia interventions and participants appearing in recent systematic reviews of aphasia intervention effectiveness. The relationship between the quality of these descriptions and the robustness of research design is explored, and the replicability of aphasia interventions is evaluated.
The scope of our search was an analysis of the aphasia intervention studies included in the and EBRSR 2018 systematic reviews, and in the RCSLT 2014 literature synthesis. Intervention descriptions published separately from the intervention study (i.e. published online, in clinical tools, or a separate trial protocols) were not included. The criteria for inclusion were that participants had aphasia, the intervention involved language and/or communication, and included the following research designs: Randomised Controlled Trial (RCT), comparison or control, crossover design, case series. Exclusion criteria included non-SLT interventions, studies involving fewer than four participants, conference abstracts, studies not available in English. Studies were evaluated for completeness of intervention description using the TIDieR Checklist. Additionally, we rated the quality of patient and intervention description, with particular reference to replicability.
Ninety-three studies were included. Only 14 studies (15%) had >50 participants. Fifty-six studies (60%) did not select participants with a specific aphasia profile, and a further 10 studies only described participants as non-fluent. Across the studies, an average of eight (of 12) TIDieR checklist items were given but information on where, tailoring, modification and fidelity items was rarely available. Studies that evaluated general aphasia intervention approaches tended to use RCT designs, whereas more specific intervention studies were more likely to use case series designs.
: Group studies were generally under-powered and there was a paucity of research looking at specific aphasia interventions for specific aphasia profiles. There was a trade-off between the robustness of the design and the level of specificity of the intervention described. While the TIDieR framework is a useful guide to information which should be included in an intervention study, it is insufficiently sensitive for assessing replicability. We consider possible solutions to the challenges of making large-scale trials more useful for determining effective aphasia intervention.
Context. The high-mass microquasar Cyg X-1, the best-established candidate for a stellar-mass black hole in the Galaxy, has been detected in a flaring state at very high energies (VHE), E > 200 GeV, ...by the Atmospheric Cherenkov Telescope MAGIC. The flare occurred at orbital phase ϕ = 0.91, where ϕ = 1 is the configuration with the black hole behind the companion high-mass star, when the absorption of gamma-ray photons by photon-photon annihilation with the stellar field is expected to be highest. Aims. We aim to set up a model for the high-energy emission and absorption in Cyg X-1 that can explain the nature of the observed gamma-ray flare. Methods. We study the gamma-ray opacity due to pair creation along the whole orbit, and for different locations of the emitter. Then we consider a possible mechanism for the production of the VHE emission. Results. We present detailed calculations of the gamma-ray opacity and infer from these calculations the distance from the black hole where the emitting region was located. We suggest that the flare was the result of a jet-clump interaction where the decay products of inelastic p - p collisions dominate the VHE outcome. Conclusions. We are able to reproduce the spectrum of Cyg X-1 during the observed flare under reasonable assumptions. The flare may be the first event of jet-cloud interaction ever detected at such high energies.
Context.LS I +61 303 is a puzzling Be/X-ray binary with variable gamma-ray emission up to TeV energies. The nature of the compact object and the origin of the high-energy emission are unclear. One ...family of models invokes particle acceleration in shocks from the collision between the B-star wind and a relativistic pulsar wind, whereas another centers on a relativistic jet powered by accretion from the Be star decretion disc onto a black hole. Recent high-resolution radio observations showing a putative “cometary tail” pointing away from the Be star near periastron have been cited as support for the pulsar-wind model. Aims.We wish to carry out a quantitative assessment of these competing models. Methods.We apply a “Smoothed Particle Hydrodynamics” (SPH) code in 3D dynamical simulations for both the pulsar-wind-interaction and accretion-jet models. The former yields a dynamical description of the shape of the wind-wind interaction surface. The latter provides a dynamical estimation of the accretion rate under a variety of conditions, and how this varies with orbital phase. Results. The results allow critical evaluation of how the two distinct models confront the data in various wavebands. When one accounts for the 3D dynamical wind interaction under realistic constraints for the relative strength of the B-star and pulsar winds, the resulting form of the interaction front does not match the putative “cometary tail” claimed from radio observations. On the other hand, dynamical simulations of the accretion-jet model indicate that the orbital phase variation of accretion power includes a secondary broad peak well away from periastron, thus providing a plausible way to explain the observed TeV gamma ray emission toward apastron. Conclusions. Contrary to previous claims, the colliding-wind model is not clearly established for LS I +61 303, whereas the accretion-jet model can reproduce many key characteristics, such as required energy budget, lightcurve, and spectrum of the observed TeV gamma-ray emission.
Sparse time series models have shown promise in estimating contemporaneous and ongoing brain connectivity. This paper was motivated by a neuroscience experiment using EEG signals as the outcome of ...our established interventional protocol, a new method in neurorehabilitation toward developing a treatment for visual verticality disorder in post-stroke patients. To analyze the complex outcome measure (EEG) that reflects neural-network functioning and processing in more specific ways regarding traditional analyses, we make a comparison among sparse time series models (classic VAR, GLASSO, TSCGM, and TSCGM-modified with non-linear and iterative optimizations) combined with a graphical approach, such as a Dynamic Chain Graph Model (DCGM). These dynamic graphical models were useful in assessing the role of estimating the brain network structure and describing its causal relationship. In addition, the class of DCGM was able to visualize and compare experimental conditions and brain frequency domains using finite impulse response (FIR) filter. Moreover, using multilayer networks, the results corroborate with the susceptibility of sparse dynamic models, bypassing the false positives problem in estimation algorithms. We conclude that applying sparse dynamic models to EEG data may be useful for describing intervention-relocated changes in brain connectivity.
Context.It has been proposed that the origin of the very high-energy photons emitted from high-mass X-ray binaries with jet-like features, so-called microquasars (MQs), is related to hadronic ...interactions between relativistic protons in the jet and cold protons of the stellar wind. Leptonic secondary emission should be calculated in a complete hadronic model that includes the effects of pairs from charged pion decays inside the jets and the emission from pairs generated by gamma-ray absorption in the photosphere of the system. Aims.We aim at predicting the broadband spectrum from a general hadronic microquasar model, taking into account the emission from secondaries created by charged pion decay inside the jet. Methods.The particle energy distribution for secondary leptons injected along the jets is consistently derived taking the energy losses into account. The spectral energy distribution resulting from these leptons is calculated after assuming different values of the magnetic field inside the jets. We also compute the spectrum of the gamma-rays produced by neutral pion-decay and processed by electromagnetic cascades under the stellar photon field. Results.We show that the secondary emission can dominate the spectral energy distribution at low energies (~1 MeV). At high energies, the production spectrum can be significantly distorted by the effect of electromagnetic cascades. These effects are phase-dependent, and some variability modulated by the orbital period is predicted.
Microquasars are accreting X-ray binary systems with non-thermal radio jets. In some of these systems the jet is expected to be strongly misaligned with the perpendicular to the orbital plane. If the ...donor star is an early-type star, the jet could collide with the stellar wind producing a standing shock between the compact object and the stellar surface. Relativistic particles injected by the jet can be re-accelerated and isotropized at the colliding region. If the jet has hadronic content, TeV protons will diffuse into the inner, dense wind leading to gamma-ray and neutrino production from interactions with the matter of the wind. In the case of very powerful jets, the wind pressure can be overbalanced and the jet might impact directly onto the stellar surface. We present estimates of the gamma-ray and neutrino luminosities for different sets of parameters in these scenarios and we briefly discuss the effects of this radiation on the donor star and its detectability with current instruments.
The aim of the study was to develop and validate a Spanish version of the Revised Depression Attitude Questionnaire (R-DAQ).
The R-DAQ was used as a baseline for the study. It was translated and ...tested to ensure the instrument was appropriate for the target population. 537 Ecuadorian healthcare professionals completed the revised Spanish version of the R-DAQ (SR-DAQ). Statistical and exploratory factor analyses were performed to examine construct validity, internal consistency, readability and floor and ceiling effects.
Three factors were obtained: "Professional confidence in depression care"; "Therapeutic optimism about depression"; and "Generalist perspective about depression occurrence, recognition, and management". The internal consistency of the SR-DAQ was determined by means of Cronbach's α coefficient, with values ranging between 0.61-0.8. The correlations with the English version reflected adequate validity. The model explained 39% of the variance. Subsequent analysis with a sample restricted to those who had received training in depression produced a model that explained 42% of the variance.
The SR-DAQ meets the psychometric requirements for measuring depression attitude in a Spanish-speaking population and shows adequate internal consistency and validity.
BACKGROUND: To identify the most appropriate dose for the prevention of transfusion‐associated graft‐versus‐host disease, the radiosensitivity of T cells has been determined in blood bags irradiated ...with X‐rays produced by a linear accelerator and gamma rays derived from the cesium‐137 source of a specific irradiator. In this study, the influence of doses ranging from 500 to 2500 cGy was investigated on T cells isolated from red blood cell (RBC) units preserved with ADSOL and irradiated with a cobalt teletherapy unit.
STUDY DESIGN AND METHODS: A thermal device consisting of acrylic and foam was constructed to store the blood bags during irradiation. Blood temperature was monitored with an automated data acquisition system. Dose distribution in the blood bags was analyzed based on isodose curves obtained with a polystyrene phantom constructed for this purpose. The influence of cobalt‐60 gamma radiation on T cells was determined by limiting‐dilution analysis, which measures clonable T cells. T‐cell content of the mononuclear cell population plated was assessed by flow cytometry with a monoclonal antibody specific for CD3.
RESULTS: Blood temperature ranged from 2 to 4.5°C during irradiation. Dosimetry performed on the phantom showed a homogenous dose distribution when the phantom was irradiated with a parallel‐opposite field. A radiation dose of 1500 cGy led to the inactivation of T cells by 4 log, but T‐cell growth was observed in all experiments. At 2500 cGy, no T‐cell growth was detected in any of the experiments and a greater than 5 log reduction in functional T cells was noted.
CONCLUSION: The results showed that a dose of 2500 cGy completely inactivates T cells in RBC units irradiated with cobalt‐60 source.
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