64 research outputs found

    Exposure of Egyptian Rousette Bats (\u3ci\u3eRousettus aegyptiacus\u3c/i\u3e) and a Little Free-Tailed Bat (\u3ci\u3eChaerephon pumilus\u3c/i\u3e) to Alphaviruses in Uganda

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    The reservoir for zoonotic o’nyong-nyong virus (ONNV) has remained unknown since this virus was first recognized in Uganda in 1959. Building on existing evidence for mosquito bloodfeeding on various frugivorous bat species in Uganda, and seroprevalence for arboviruses among bats in Uganda, we sought to assess if serum samples collected from bats in Uganda demonstrated evidence of exposure to ONNV or the closely related zoonotic chikungunya virus (CHIKV). In total, 652 serum samples collected from six bat species were tested by plaque reduction neutralization test (PRNT) for neutralizing antibodies against ONNV and CHIKV. Forty out of 303 (13.2%) Egyptian rousettes from Maramagambo Forest and 1/13 (8%) little free-tailed bats from Banga Nakiwogo, Entebbe contained neutralizing antibodies against ONNV. In addition, 2/303 (0.7%) of these Egyptian rousettes contained neutralizing antibodies to CHIKV, and 8/303 (2.6%) contained neutralizing antibodies that were nonspecifically reactive to alphaviruses. These data support the interepidemic circulation of ONNV and CHIKV in Uganda, although Egyptian rousette bats are unlikely to serve as reservoirs for these viruses given the inconsistent occurrence of antibody-positive bats

    TOI-3785 b: A Low-Density Neptune Orbiting an M2-Dwarf Star

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    Using both ground-based transit photometry and high-precision radial velocity (RV) spectroscopy, we confirm the planetary nature of TOI-3785 b. This transiting Neptune orbits an M2-Dwarf star with a period of ~4.67 days, a planetary radius of 5.14 +/- 0.16 Earth Radii, a mass of 14.95 +4.10, -3.92 Earth Masses, and a density of 0.61 +0.18, -0.17 g/cm^3. TOI-3785 b belongs to a rare population of Neptunes (4 Earth Radii < Rp < 7 Earth Radii) orbiting cooler, smaller M-dwarf host stars, of which only ~10 have been confirmed. By increasing the number of confirmed planets, TOI-3785 b offers an opportunity to compare similar planets across varying planetary and stellar parameter spaces. Moreover, with a high transmission spectroscopy metric (TSM) of ~150 combined with a relatively cool equilibrium temperature of 582 +/- 16 K and an inactive host star, TOI-3785 b is one of the more promising low-density M-dwarf Neptune targets for atmospheric follow-up. Future investigation into atmospheric mass loss rates of TOI-3785 b may yield new insights into the atmospheric evolution of these low-mass gas planets around M-dwarfs.Comment: 22 pages, 6 figures, 6 tables, Submitted to A

    The unusual M-dwarf Warm Jupiter TOI-1899~b: Refinement of orbital and planetary parameters

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    TOI-1899~b is a rare exoplanet, a temperate Warm Jupiter orbiting an M-dwarf, first discovered by \citet{Canas2020_toi1899} from a TESS single-transit event. Using new radial velocities (RVs) from the precision RV spectrographs HPF and NEID, along with additional TESS photometry and ground-based transit follow-up, we are able to derive a much more precise orbital period of P=29.0903120.000035+0.000036P = 29.090312_{-0.000035}^{+0.000036}~d, along with a radius of Rp=0.99±0.03R_p = 0.99\pm0.03~\unit{R_{J}}. We have also improved the constraints on planet mass, Mp=0.67±0.04M_p = 0.67\pm{0.04}~\unit{M_{J}}, and eccentricity, which is consistent with a circular orbit at 2σ\sigma (e=0.0440.027+0.029e = 0.044_{-0.027}^{+0.029}). TOI-1899~b occupies a unique region of parameter space as the coolest known (TeqT_{eq} \approx 380~K) Jovian-sized transiting planet around an M-dwarf; we show that it has great potential to provide clues regarding the formation and migration mechanisms of these rare gas giants through transmission spectroscopy with JWST as well as studies of tidal evolution.Comment: 19 pages, 7 figures, 3 tables, submitted to AJ (comments welcome

    A Pro-Cathepsin L Mutant Is a Luminal Substrate for Endoplasmic-Reticulum-Associated Degradation in C. elegans

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    Endoplasmic-reticulum associated degradation (ERAD) is a major cellular misfolded protein disposal pathway that is well conserved from yeast to mammals. In yeast, a mutant of carboxypeptidase Y (CPY*) was found to be a luminal ER substrate and has served as a useful marker to help identify modifiers of the ERAD pathway. Due to its ease of genetic manipulation and the ability to conduct a genome wide screen for modifiers of molecular pathways, C. elegans has become one of the preferred metazoans for studying cell biological processes, such as ERAD. However, a marker of ERAD activity comparable to CPY* has not been developed for this model system. We describe a mutant of pro-cathepsin L fused to YFP that no longer targets to the lysosome, but is efficiently eliminated by the ERAD pathway. Using this mutant pro-cathepsin L, we found that components of the mammalian ERAD system that participate in the degradation of ER luminal substrates were conserved in C. elegans. This transgenic line will facilitate high-throughput genetic or pharmacological screens for ERAD modifiers using widefield epifluorescence microscopy

    TOI-5205b: A Jupiter transiting an M dwarf near the Convective Boundary

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    We present the discovery of TOI-5205b, a transiting Jovian planet orbiting a solar metallicity M4V star, which was discovered using TESS photometry and then confirmed using a combination of precise radial velocities, ground-based photometry, spectra and speckle imaging. The host star TOI-5205 sits near the eponymous `Jao gap', which is the transition region between partially and fully-convective M dwarfs. TOI-5205b has one of the highest mass ratio for M dwarf planets with a mass ratio of almost 0.3%\%, as it orbits a host star that is just 0.392±0.0150.392 \pm 0.015 MM_{\odot}. Its planetary radius is 1.03±0.03 RJ1.03 \pm 0.03~R_J, while the mass is 1.08±0.06 MJ1.08 \pm 0.06~M_J. Additionally, the large size of the planet orbiting a small star results in a transit depth of 7%\sim 7\%, making it one of the deepest transits of a confirmed exoplanet orbiting a main-sequence star. The large transit depth makes TOI-5205b a compelling target to probe its atmospheric properties, as a means of tracing the potential formation pathways. While there have been radial velocity-only discoveries of giant planets around mid M dwarfs, this is the first transiting Jupiter with a mass measurement discovered around such a low-mass host star. The high mass of TOI-5205b stretches conventional theories of planet formation and disk scaling relations that cannot easily recreate the conditions required to form such planets.Comment: Submitted to ApJ. Comments are welcome. arXiv admin note: text overlap with arXiv:2203.0717

    Why Does Exercise “Triggerâ€? Adaptive Protective Responses in the Heart?

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    Numerous epidemiological studies suggest that individuals who exercise have decreased cardiac morbidity and mortality. Pre-clinical studies in animal models also find clear cardioprotective phenotypes in animals that exercise, specifically characterized by lower myocardial infarction and arrhythmia. Despite the clear benefits, the underlying cellular and molecular mechanisms that are responsible for exercise preconditioning are not fully understood. In particular, the adaptive signaling events that occur during exercise to “trigger� cardioprotection represent emerging paradigms. In this review, we discuss recent studies that have identified several different factors that appear to initiate exercise preconditioning. We summarize the evidence for and against specific cellular factors in triggering exercise adaptations and identify areas for future study

    Inclusive education for deaf students: literacy practices and South African sign language

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Southern African Linguistics and Applied Language Studies on 16 July 2012, available online: http://www.tandfonline.com/10.2989/16073614.2012.693707.This article considers the feasibility of inclusive education for Deaf students in a mainstream Further Education and Training (FET) classroom through the use of a South African Sign Language interpreter. It revisits the centrality of language in Deaf students' education and reports on progressive policy changes in the areas of language, education and disability in South Africa. The article surveys classroom discourse and literacy practices in a mainstream FET classroom, focusing particularly on students' acquisition of text literacy skills in Business English. Drawing on theoretical frameworks from the New Literacy Studies, Critical Discourse Analysis and the Social Model of Disability, the article argues that there is definitely potential for establishing inclusive education for Deaf students in a mainstream classroom. It however highlights that there are many difficulties and challenges around providing fully inclusive education for Deaf students. It was found that the signed interpretations in this classroom frequently represent an impoverished form of language while some types of pedagogic practice impede the interpreter's signing. The article concludes that interpreters and teachers need to be trained in forms of language and pedagogy that would benefit all students in class, including Deaf students

    The Neutron star Interior Composition Explorer (NICER): design and development

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    Development of the PSYCHS: Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS

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    Aim: To harmonize two ascertainment and severity rating instruments commonly used for the clinical high risk syndrome for psychosis (CHR-P): the Structured Interview for Psychosis-risk Syndromes (SIPS) and the Comprehensive Assessment of At-Risk Mental States (CAARMS). Methods: The initial workshop is described in the companion report from Addington et al. After the workshop, lead experts for each instrument continued harmonizing attenuated positive symptoms and criteria for psychosis and CHR-P through an intensive series of joint videoconferences. Results: Full harmonization was achieved for attenuated positive symptom ratings and psychosis criteria, and modest harmonization for CHR-P criteria. The semi-structured interview, named Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS (PSYCHS), generates CHR-P criteria and severity scores for both CAARMS and SIPS. Conclusions: Using the PSYCHS for CHR-P ascertainment, conversion determination, and attenuated positive symptom severity rating will help in comparing findings across studies and in meta-analyses
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