60 research outputs found
Enhanced PTC Effect in Polyamide/Carbon Black Composites
Self-heating nanocomposites with a positive temperature coefficient (PTC) provide outstanding potential for a broad range of engineering applications in automobile, spacecraft, or smart building. Therefore, extensive studies have been carried out to understand thermo-electrical behavior. However, some controversies remain, especially on the material composition, to clarify influencing factors on the PTC performance. In this study, the thermo-electrical behaviors of injection molded carbon black (CB)/polyamide (PA) nanocomposites have been investigated. Three types of CB with well-defined specific surface area and polyamides with high and low crystallinity were selected to provide a guideline for self-heating devices including PTC-Effects. Significantly reduced specific resistances up to 2.7 Ω·cm were achieved by incorporating CB with a high specific surface area into a highly crystalline PA. Noticeable PTC-Effects of ~53% and average surface temperatures up to 147 °C have been observed due to self-heating, which confirms a promising material performance as a heating device
Edge-resolved transient imaging: performance analyses, optimizations, and simulations
Edge-resolved transient imaging (ERTI) is a method for non-line-of-sight imaging that combines the use of direct time of flight for measuring distances with the azimuthal angular resolution afforded by a vertical edge occluder. Recently conceived and demonstrated for the first time, no performance analyses or optimizations of ERTI have appeared in published papers. This paper explains how the difficulty of detection of hidden scene objects with ERTI depends on a variety of parameters, including illumination power, acquisition time, ambient light, visible-side reflectivity, hidden-side reflectivity, target range, and target azimuthal angular position. Based on this analysis, optimization of the acquisition process is introduced whereby the illumination dwell times are varied to counteract decreasing signal-to-noise ratio at deeper angles into the hidden volume. Inaccuracy caused by a coaxial approximation is also analyzed and simulated.Accepted manuscrip
The North Atlantic Waveguide and Downstream Impact Experiment
The North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) explored the impact of diabatic processes on disturbances of the jet stream and their influence on downstream high-impact weather through the deployment of four research aircraft, each with a sophisticated set of remote sensing and in situ instruments, and coordinated with a suite of ground-based measurements. A total of 49 research flights were performed, including, for the first time, coordinated flights of the four aircraft: the German High Altitude and Long Range Research Aircraft (HALO), the Deutsches Zentrum fĂŒr Luft- und Raumfahrt (DLR) Dassault Falcon 20, the French Service des Avions Français InstrumentĂ©s pour la Recherche en Environnement (SAFIRE) Falcon 20, and the British Facility for Airborne Atmospheric Measurements (FAAM) BAe 146. The observation period from 17 September to 22 October 2016 with frequently occurring extratropical and tropical cyclones was ideal for investigating midlatitude weather over the North Atlantic. NAWDEX featured three sequences of upstream triggers of waveguide disturbances, as well as their dynamic interaction with the jet stream, subsequent development, and eventual downstream weather impact on Europe. Examples are presented to highlight the wealth of phenomena that were sampled, the comprehensive coverage, and the multifaceted nature of the measurements. This unique dataset forms the basis for future case studies and detailed evaluations of weather and climate predictions to improve our understanding of diabatic influences on Rossby waves and the downstream impacts of weather systems affecting Europe
The Human Phenotype Ontology in 2024: phenotypes around the world.
The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English. Since our last report, a total of 2239 new HPO terms and 49235 new HPO annotations were developed, many in collaboration with external groups in the fields of psychiatry, arthrogryposis, immunology and cardiology. The Medical Action Ontology (MAxO) is a new effort to model treatments and other measures taken for clinical management. Finally, the HPO consortium is contributing to efforts to integrate the HPO and the GA4GH Phenopacket Schema into electronic health records (EHRs) with the goal of more standardized and computable integration of rare disease data in EHRs
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009aâb; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
The genetic architecture of the human cerebral cortex
The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Substrate Hydrophobicity and Cell Composition Influence the Extent of Rate Limitation and Masking of Isotope Fractionation during Microbial Reductive Dehalogenation of Chlorinated Ethenes
This
study investigated the effect of intracellular microscale mass transfer
on microbial carbon isotope fractionation of tetrachloroethene (PCE)
and trichloroethene (TCE). Significantly stronger isotope fractionation
was observed for crude extracts vs intact cells of <i>Sulfurospirillum
multivorans</i>, <i>Geobacter lovleyi</i>, <i>Desulfuromonas michiganensis</i>, <i>Desulfitobacterium
hafniense</i> strain PCE-S, and <i>Dehalobacter restrictus</i>. Furthermore, carbon stable isotope fractionation was stronger for
microorganisms with a Gram-positive cell envelope compared to those
with a Gram-negative cell envelope. Significant differences were observed
between model organisms in cellular sorption capacity for PCE (<i>S. multivorans</i>-K<sub>dâPCE</sub> = 0.42â0.51
L g<sup>â1</sup>; <i>D. hafniense</i>-K<sub>dâPCE</sub> = 0.13 L g<sup>â1</sup>), as well as in envelope hydrophobicity
(<i>S. multivorans</i> 33.0° to 72.2°; <i>D. hafniense</i> 59.1° to 60.8°) when previously cultivated
with fumarate or PCE as electron acceptor, but not for TCE. Cell envelope
properties and the tetrachloroethene reductive dehalogenase (PceA-RDase)
localization did not result in significant effects on observed isotope
fractionation of TCE. For PCE, however, systematic masking of isotope
effects as a result of microscale mass transfer limitation at microbial
membranes was observed, with carbon isotope enrichment factors of
â2.2â°, â1.5 to â1.6â°, and â1.0â°
(CI<sub>95%</sub> < ± 0.2â°) for no membrane, hydrophilic
outer membrane, and outer + cytoplasmic membrane, respectively. Conclusively,
rate-limiting mass transfer barriers were (a) the outer membrane or
cell wall and (b) the cytoplasmic membrane in case of a cytoplasmic
location of the RDase enzyme. Overall, our results indicate that masking
of isotope fractionation is determined by (1) hydrophobicity of the
degraded compound, (2) properties of the cell envelope, and (3) the
localization of the reacting enzyme
Unscented Kalman Filter for Real-Time Load Swing Estimation of Container Cranes Using Rope Forces
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