2,093 research outputs found

    A Boreing Night of Observations of the Upper Mesosphere and Lower Thermosphere Over the Andes Lidar Observatory

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    A very high-spatial resolution (∼21-23 m pixel at 85 km altitude) OH airglow imager at the Andes Lidar Observatory at Cerro Pach´on, Chile observed considerable ducted wave activity on the night of October 29-30, 2016. This instrument was collocated with a Na wind-temperature lidar that provided data revealing the occurrence of strong ducts. A large field of view OH and greenline airglow imager showed waves present over a vertical extent consistent with the altitudes of the ducting features identified in the lidar profiles. While waves that appeared to be ducted were seen in all imagers throughout the observation interval, the wave train seen in the OH images at earlier times had a distinct leading non-sinusoidal phase followed by several, lower-amplitude, more sinusoidal phases, suggesting a likely bore. The leading phase exhibited significant dissipation via small-scale secondary instabilities suggesting vortex rings that progressed rapidly to smaller scales and turbulence (the latter not fully resolved) thereafter. The motions of these small-scale features were consistent with their location in the duct at or below ∼83-84 km. Bore dissipation caused a momentum flux divergence and a local acceleration of the mean flow within the duct along the direction of the initial bore propagation. A number of these features are consistent with mesospheric bores observed or modeled in previous studies

    Surveillance of Vermont wildlife in 2021–2022 reveals no detected SARS-CoV-2 viral RNA

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    Abstract Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont. 739 nasal or throat samples were collected from wildlife throughout the state during the 2021 and 2022 harvest season. Data was collected from red and gray foxes (Vulpes vulples and Urocyon cineroargentus, respectively), fishers (Martes pennati), river otters (Lutra canadensis), coyotes (Canis lantrans), bobcats (Lynx rufus rufus), black bears (Ursus americanus), and white-tailed deer (Odocoileus virginianus). Samples were tested for the presence of SARS-CoV-2 via quantitative RT-qPCR using the CDC N1/N2 primer set and/or the WHO-E gene primer set. Surprisingly, we initially detected a number of N1 and/or N2 positive samples with high cycle threshold values, though after conducting environmental swabbing of the laboratory and verifying with a second independent primer set (WHO-E) and PCR without reverse transcriptase, we showed that these were false positives due to plasmid contamination from a construct expressing the N gene in the general laboratory environment. Our final results indicate that no sampled wildlife were positive for SARS-CoV-2 RNA, and highlight the importance of physically separate locations for the processing of samples for surveillance and experiments that require the use of plasmid DNA containing the target RNA sequence. These negative findings are surprising, given that most published North America studies have found SARS-CoV-2 within their deer populations. The absence of SARS-CoV-2 RNA in populations sampled here may provide insights in to the various environmental and anthropogenic factors that reduce spillover and spread in North American’s wildlife populations

    Canadian Snow Radar Satellite Mission Science Readiness Advancements

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    Environment and Climate Change Canada (ECCC) and the Canadian Space Agency (CSA) continue to advance a new satellite Ku-band radar mission focused on providing moderate resolution (500 m) information on seasonal snow mass. Like many regions of the northern hemisphere, estimates of the amount of water stored as seasonal snow are highly uncertain across Canada. To address this gap, a technical concept capable of providing dual-polarization (VV/VH), moderate resolution (500 m), wide swath (~250 km), and high duty cycle (~25% SAR-on time) Ku-band radar measurements at two frequencies (13.5; 17.25 GHz) is under development. In this presentation, results from the Trail Valley Creek experiment (TVCEx) conducted in winter of 2018-19 will be presented. Data collected during the CryoSAR 2022-23 campaign in Powassan, Ontario, Canada will also be shown in the context of how the proposed snow radar mission can improve SWE retrievals in agricultural lands. Using the UMASS airborne Ku-band radar instrument and satellite observations from RADARSAT-2 and TerraSAR-X, we show that it is possible to retrieve background soil properties allowing to separate the background from the snowpack contribution of the Ku-band signal and isolate the snow volume scattering to facilitate radar-based SWE retrievals. We also show that the ground-based snow sampling strategy deployed during the TVCEx, providing statistical distributions of snow microstructure and density, is crucial to properly estimate the radar signal from forward modelling. Ground-based snow properties, soil and weather station information, drone LiDAR/optical data and radar observations collected for the CryoSAR campaign will also be presented

    Integrated Machine Learning and Multivariate Analysis for Quantifying the Relative Contribution of Terrestrial Organic Matter to Marine Sediments: A Case Study in Environmental Geochemistry.Mirzaei et al.

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    Analysis of length of stay and treatment emergent complications in hospitalized myasthenia gravis patients with exacerbation

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    Abstract Introduction AIMS Myasthenia Gravis (MG) is an autoimmune neuromuscular disease in which patients suffer from recurrent exacerbation. There are insufficient data measuring the effects of the resources employed before and during acute exacerbation on subsequent disease outcomes. This study aims to identify factors which lead to lengthened hospital stay. Methods This is a retrospective chart review of acute MG exacerbations requiring hospitalization. Exacerbations were identified using ICD-9/ICD-10 codes and considered the following variables: age and Myasthenia Gravis Foundation of America (MGFA) class at initial MG diagnosis, age and MGFA class at exacerbation, sex, thymectomy, cause of exacerbation, treatment regimen at time of exacerbation, inpatient treatment regimen, length of hospital stay (LOS), intubation, use of noninvasive ventilation, complications, and disposition. Results Seventy patients with 141 hospitalizations were identified. Crisis management characterized by intubation and plasmapheresis positively correlated with LOS (both p < .001). Almost 1/5 hospitalizations required intubation. Previous thymectomy negatively correlated with LOS (p < .05). In contrast, male sex correlated with longer LOS (p < .05). One-third of hospital stays were followed by discharge to a post-acute care facility, 7% home with home health, and 1 hospitalization resulted in death. Discussion Plasmapheresis, intubation, and male sex were associated with increased LOS in acute MG exacerbation. Intubation appears to be the strongest predictor of LOS. Those with previous thymectomy had shorter hospital stays. The role of thymectomy in the acute setting merits further analysis

    Symptom assessment for mechanically ventilated patients: Principles and priorities

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    Mechanically ventilated patients experience many adverse symptoms, such as anxiety, thirst, and dyspnea. However, these common symptoms are not included in practice guideline recommendations for routine assessment of mechanically ventilated patients. An American Thoracic Society-sponsored workshop with researchers and clinicians with expertise in critical care and symptom management was convened for a discussion of symptom assessment in mechanically ventilated patients. Members included nurses, physicians, a respiratory therapist, a speech–language pathologist, a critical care pharmacist, and a former intensive care unit patient. This report summarizes existing evidence and consensus among workshop participants regarding 1) symptoms that should be considered for routine assessment of adult patients receiving mechanical ventilation; 2) key symptom assessment principles; 3) strategies that support symptom assessment in nonvocal patients; and 4) areas for future clinical practice development and research. Systematic patient-centered assessment of multiple symptoms has great potential to minimize patient distress and improve the patient experience. A culture shift is necessary to promote ongoing holistic symptom assessment with valid and reliable instruments. This report represents our workgroup consensus on symptom assessment for mechanically ventilated patients. Future work should address how holistic, patient-centered symptom assessment can be embedded into clinical practice

    Plant electrophysiology with conformable organic electronics: Deciphering the propagation of Venus flytrap action potentials

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    Electrical signals in plants are mediators of long-distance signaling and correlate with plant movements and responses to stress. These signals are studied with single surface electrodes that cannot resolve signal propagation and integration, thus impeding their decoding and link to function. Here, we developed a conformable multielectrode array based on organic electronics for large-scale and high-resolution plant electrophysiology. We performed precise spatiotemporal mapping of the action potential (AP) in Venus flytrap and found that the AP actively propagates through the tissue with constant speed and without strong directionality. We also found that spontaneously generated APs can originate from unstimulated hairs and that they correlate with trap movement. Last, we demonstrate that the Venus flytrap circuitry can be activated by cells other than the sensory hairs. Our work reveals key properties of the AP and establishes the capacity of organic bioelectronics for resolving electrical signaling in plants contributing to the mechanistic understanding of long-distance responses in plants

    Elucidating mechanisms of genetic cross-disease associations at the PROCR vascular disease locus

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    Many individual genetic risk loci have been associated with multiple common human diseases. However, the molecular basis of this pleiotropy often remains unclear. We present an integrative approach to reveal the molecular mechanism underlying the PROCR locus, associated with lower coronary artery disease (CAD) risk but higher venous thromboembolism (VTE) risk. We identify PROCR-p.Ser219Gly as the likely causal variant at the locus and protein C as a causal factor. Using genetic analyses, human recall-by-genotype and in vitro experimentation, we demonstrate that PROCR-219Gly increases plasma levels of (activated) protein C through endothelial protein C receptor (EPCR) ectodomain shedding in endothelial cells, attenuating leukocyte-endothelial cell adhesion and vascular inflammation. We also associate PROCR-219Gly with an increased pro-thrombotic state via coagulation factor VII, a ligand of EPCR. Our study, which links PROCR-219Gly to CAD through anti-inflammatory mechanisms and to VTE through pro-thrombotic mechanisms, provides a framework to reveal the mechanisms underlying similar cross-phenotype associations.Many individual genetic risk loci associate with multiple diseases, but the molecular basis of these loci often remains unclear. Here, the authors provide a framework to reveal the genetic cross-disease associations at the PROCR vascular disease locus
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