Context . Gamma-ray bursts (GRBs) are ideal probes of the Universe at high redshift (ɀ), pinpointing the locations of the earliest star-forming galaxies and providing bright backlights with simple ...featureless power-law spectra that can be used to spectrally fingerprint the intergalactic medium and host galaxy during the period of reionization. Future missions such as Gamow Explorer (hereafter Gamow) are being proposed to unlock this potential by increasing the rate of identification of high-ɀ (ɀ > 5) GRBs in order to rapidly trigger observations from 6 to 10 m ground telescopes, the James Webb Space Telescope (JWST), and the upcoming Extremely Large Telescopes (ELTs). Aims . Gamow was proposed to the NASA 2021 Medium-Class Explorer (MIDEX) program as a fast-slewing satellite featuring a wide-field lobster-eye X-ray telescope (LEXT) to detect and localize GRBs with arcminute accuracy, and a narrow-field multi-channel photo-ɀ infrared telescope (PIRT) to measure their photometric redshifts for > 80% of the LEXT detections using the Lyman- α dropout technique. We use a large sample of observed GRB afterglows to derive the PIRT sensitivity requirement. Methods . We compiled a complete sample of GRB optical–near-infrared (optical-NIR) afterglows from 2008 to 2021, adding a total of 66 new afterglows to our earlier sample, including all known high-ɀ GRB afterglows. This sample is expanded with over 2837 unpublished data points for 40 of these GRBs. We performed full light-curve and spectral-energy-distribution analyses of these after-glows to derive their true luminosity at very early times. We compared the high-ɀ sample to the comparison sample at lower redshifts. For all the light curves, where possible, we determined the brightness at the time of the initial finding chart of Gamow, at different high redshifts and in different NIR bands. This was validated using a theoretical approach to predicting the afterglow brightness. We then followed the evolution of the luminosity to predict requirements for ground- and space-based follow-up. Finally, we discuss the potential biases between known GRB afterglow samples and those to be detected by Gamow. Results . We find that the luminosity distribution of high-ɀ GRB afterglows is comparable to those at lower redshift, and we therefore are able to use the afterglows of lower-ɀ GRBs as proxies for those at high ɀ. We find that a PIRT sensitivity of 15 µJy (21 mag AB) in a 500 s exposure simultaneously in five NIR bands within 1000 s of the GRB trigger will meet the Gamow mission requirements. Depending on the ɀ and NIR band, we find that between 75% and 85% of all afterglows at ɀ > 5 will be recovered by Gamow at 5 σ detection significance, allowing the determination of a robust photo-ɀ. As a check for possible observational biases and selection effects, we compared the results with those obtained through population-synthesis models, and find them to be consistent. Conclusions . Gamow and other high-ɀ GRB missions will be capable of using a relatively modest 0.3 m onboard NIR photo-ɀ telescope to rapidly identify and report high-ɀ GRBs for further follow-up by larger facilities, opening a new window onto the era of reionization and the high-redshift Universe.
The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46x10;{20} protons on target, 544 electronlike events are ...observed in this energy range, compared to an expectation of 415.2+/-43.4 events, corresponding to an excess of 128.8+/-20.4+/-38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu_{e} and nuover _{e} charged-current scattering or nu_{mu} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9+/-35.7 events.
A search for sub-GeV dark matter produced from collisions of the Fermilab 8 GeV Booster protons with a steel beam dump was performed by the MiniBooNE-DM Collaboration using data from 1.86 × 1020 ...protons on target in a dedicated run. The MiniBooNE detector, consisting of 818 tons of mineral oil and located 490 meters downstream of the beam dump, is sensitive to a variety of dark matter initiated scattering reactions. Three dark matter interactions are considered for this analysis: elastic scattering off nucleons, inelastic neutral pion production, and elastic scattering off electrons. Multiple data sets were used to constrain flux and systematic errors, and time-of-flight information was employed to increase sensitivity to higher dark matter masses. No excess from the background predictions was observed, and 90% confidence level limits were set on the vector portal and leptophobic dark matter models. New parameter space is excluded in the vector portal dark matter model with a dark matter mass between 5 and 50 MeV c−2 . The reduced neutrino flux allowed to test if the MiniBooNE neutrino excess scales with the production of neutrinos. No excess of neutrino oscillation events were measured ruling out models that scale solely by number of protons on target independent of beam configuration at 4.6σ.
The analysis of contemporary genomic data typically operates on one-dimensional phenotypic measurements (e.g. standing height). Here we report on a data-driven, family-informed strategy to facial ...phenotyping that searches for biologically relevant traits and reduces multivariate 3D facial shape variability into amendable univariate measurements, while preserving its structurally complex nature. We performed a biometric identification of siblings in a sample of 424 children, defining 1,048 sib-shared facial traits. Subsequent quantification and analyses in an independent European cohort (n = 8,246) demonstrated significant heritability for a subset of traits (0.17-0.53) and highlighted 218 genome-wide significant loci (38 also study-wide) associated with facial variation shared by siblings. These loci showed preferential enrichment for active chromatin marks in cranial neural crest cells and embryonic craniofacial tissues and several regions harbor putative craniofacial genes, thereby enhancing our knowledge on the genetic architecture of normal-range facial variation.
Lethal Malaria: Marchiafava and Bignami Were Right White, Nicholas J.; Turner, Gareth D. H.; Day, Nicholas P. J. ...
The Journal of infectious diseases,
07/2013, Letnik:
208, Številka:
2
Journal Article
Recenzirano
Odprti dostop
One hundred and twenty years ago, the Italian malariologists Marchiafava and Bignami proposed that the fundamental pathological process underlying lethal falciparum malaria was microvascular ...obstruction. Since then, several alternative hypotheses have been proposed. These formed the basis for adjunctive interventions, which have either been ineffective or harmful. Recent evidence strongly suggests that Marchiafava and Bignami were right.
In recent years, issues surrounding transgender have garnered media and legal attention, contributing to rapidly shifting views on gender in the U.S. Yet, there is a paucity of data-driven studies on ...the public’s views of transgender identity. This study reports the development and validation of the Transgender Attitudes and Beliefs Scale (TABS). After constructing an initial 96-item pool from consulting experts and existing scales, Phase 1 of the study was launched, involving an exploratory factor analysis of 48 items. The initial factor analysis with 295 participants revealed three factors across 33 items—16 items on interpersonal comfort, 11 on sex/gender beliefs, and 6 on human value. The internal consistency of each factor was high—α = .97 for Factor 1, α = .95 for Factor 2, and α = .94 for Factor 3. A confirmatory factor analysis was conducted in the second phase with an independent sample consisting of 238 participants. The Attitudes Toward Transgender Individual Scale and the Genderism and Transphobia Scale were also included to test for convergent validity, and the Rosenberg Self-Esteem Scale and the short form of the Marlowe–Crowne Social Desirability Scale were utilized to test discriminant validity. Both of the data collection phases employed MTurk, a form of online sampling with increased diversity compared to college student samples and more generalizability to the general U.S. population. TABS represents an addition to the literature in its ability to capture a more nuanced conceptualization of transgender attitude not found in previous scales.
Respiratory distress develops in up to 25% of adults and 40% of children with severe falciparum malaria. Its diverse causes include respiratory compensation of metabolic acidosis, noncardiogenic ...pulmonary edema, concomitant pneumonia, and severe anemia. Patients with severe falciparum, vivax, and knowlesi malaria may develop acute lung injury (ALI) and ARDS, often several days after antimalarial drug treatment. ARDS rates, best characterized for severe Plasmodium falciparum , are 5% to 25% in adults and up to 29% in pregnant women; ARDS is rare in young children. ARDS pathophysiology centers on inflammatory-mediated increased capillary permeability or endothelial damage leading to diffuse alveolar damage that can continue after parasite clearance. The role of parasite sequestration in the pulmonary microvasculature is unclear, because sequestration occurs intensely in P falciparum , less so in P knowlesi , and has not been shown convincingly in P vivax . Because early markers of ALI/ARDS are lacking, fluid resuscitation in severe malaria should follow the old adage to “keep them dry.” Bacteremia and hospital-acquired pneumonia can complicate severe malaria and may contribute to ALI/ARDS. Mechanical ventilation can save life in ALI/ARDS. Basic critical care facilities are increasingly available in tropical countries. The use of lung-protective ventilation has helped to reduce mortality from malaria-induced ALI/ARDS, but permissive hypercapnia in unconscious patients is not recommended because increased intracranial pressure and cerebral swelling may occur in cerebral malaria. The best antimalarial treatment of severe malaria is IV artesunate .
The very bright electron beam required for an x-ray free-electron laser (FEL), such as the linac coherent light source (LCLS), is susceptible to a microbunching instability in the magnetic bunch ...compressors, prior to the FEL undulator. The uncorrelated electron energy spread in the LCLS can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the FEL performance. To this end, a “laser-heater” system has been installed in the LCLS injector, which modulates the energy of a 135-MeV electron bunch with an IR-laser beam in a short undulator, enclosed within a four-dipole chicane. In this paper, we report detailed measurements of laser-heater-induced energy spread, including the unexpected self-heating phenomenon when the laser energy is very low. We discuss the suppression of the microbunching instability with the laser heater and its impact on the x-ray FEL performance. We also present the analysis of these experimental results and develop a three-dimensional longitudinal space charge model to explain the self-heating effect.
The polarization properties of radio sources at very low frequencies (<200 MHz) have not been widely measured, but the new generation of low-frequency radio telescopes, including the Low Frequency ...Array (LOFAR: a Square Kilometre Array Low pathfinder), now gives us the opportunity to investigate these properties. In this paper, we report on the preliminary development of a data reduction pipeline to carry out polarization processing and Faraday tomography for data from the LOFAR Two-meter Sky Survey (LOTSS) and present the results of this pipeline from the LOTSS preliminary data release region (10h45m–15h30m right ascension, 45°–57° declination, 570 square degrees). We have produced a catalog of 92 polarized radio sources at 150 MHz at 4.′3 resolution and 1 mJy rms sensitivity, which is the largest catalog of polarized sources at such low frequencies. We estimate a lower limit to the polarized source surface density at 150 MHz, with our resolution and sensitivity, of 1 source per 6.2 square degrees. We find that our Faraday depth measurements are in agreement with previous measurements and have significantly smaller errors. Most of our sources show significant depolarization compared to 1.4 GHz, but there is a small population of sources with low depolarization indicating that their polarized emission is highly localized in Faraday depth. We predict that an extension of this work to the full LOTSS data would detect at least 3400 polarized sources using the same methods, and probably considerably more with improved data processing.
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