689 research outputs found

    Theoretical and Experimental Investigation of Heat Conduction in Air, Including Effects of Oxygen Dissociation

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    Solutions are presented for the conduction of beat through a semi-infinite gas medium having a uniform initial temperature and a constant boundary temperature. The coefficients of thermal conductivity and diffusivity are treated as variables, and the solutions are extended to the case of air at temperatures where oxygen dissociation occurs. These solutions are used together with shock-tube measurements to evaluate the integral of thermal conductivity for air as a function of temperature

    Stagnation-point Heat Transfer to Blunt Shapes in Hypersonic Flight, Including Effects of Yaw

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    An approximate theory is developed for predicting the rate of heat transfer to the stagnation region of blunt bodies in hypersonic flight. Attention is focused on the case where wall temperature is small compared to stagnation temperature. The theoretical heat-transfer rate at the stagnation point of a hemispherical body is found to agree with available experimental data. The effect of yaw on heat transfer to a cylindrical stagnation region is treated at some length, and it is predicted that large yaw should cause sizable reductions in heat-transfer rate

    Virtual and augmented reality in social skills interventions for individuals with autism spectrum disorder: A scoping review

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    In the last decade, there has been an increase in publications on technology-based interventions for autism spectrum disorder (ASD). Virtual reality based assessments and intervention tools are promising and have shown to be acceptable amongst individuals with ASD. This scoping review reports on 49 studies utilizing virtual reality and augmented reality technology in social skills interventions for individuals with ASD. The included studies mostly targeted children and adolescents, but few targeted very young children or adults. Our findings show that the mode number of participants with ASD is low, and that female participants are underrepresented. Our review suggests that there is need for studies that apply virtual and augmented realty with more rigorous designs involving established and evidenced-based intervention strategies.publishedVersio

    Virtual reality and naturalistic developmental behavioral interventions for children with autism spectrum disorder

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    © 2021 The Author(s).Background: Naturalistic Developmental Behavioral Interventions (NDBI) have been evaluated as the most promising interventions for children with autism spectrum disorder. In recent years, a growing body of literature suggests that technological advancements such as Virtual Reality (VR) are promising intervention tools. However, to the best of our knowledge no studies have combined evidence-based practice with such tools. Aim: This article aims to review the current literature combining NDBI and VR, and provide suggestions on merging NDBI-approaches with VR. Methods: This article is divided into two parts, where we first conduct a review mapping the research applying NDBI-approaches in VR. In the second part we argue how to apply the common features of NDBI into VR-technology. Results: Our findings show that no VR-studies explicitly rely on NDBI-approaches, but some utilize elements in their interventions that are considered to be common features to NDBI. Conclusions and implications: As the results show, to date, no VR-based studies have utilized NDBI in their intervention. We therefore, in the second part of this article, suggests ways to merge VR and NDBI and introduce the term Virtual Naturalistic Developmental Behavioral Interventions (VNDBI). VNDBI is an innovative way of implementing NDBI which will contribute in making interventions more accessible in central as well as remote locations, while reducing unwanted variation between service sites. VNDBI will advance the possibilities of individually tailoring and widen the area of interventions. In addition, VNDBI can provide the field with new knowledge on effective components enhancing the accuracy in the intervention packages and thus move forward the research field and clinical practice.publishedVersio

    Enhancing the Understanding of Clinically Meaningful Results: A Clinical Research Perspective

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    Published research often address aspects related to “statistical significance” but fail to address the clinical and practical importance and meaning of results. Our main objectives in this article are to investigate the merit of common measures of Effect Size in statistical research and to highlight the importance of the simple Relative Risk ratio. In this article we present data where we consider two widely utilized effect size measures (Cohen's d and Pearson's r) in relations to relative risk. We conclude that probability analyses of risk surpass the most commonly used statistical approach used in clinical trials today and should thus be the preferred compared to the misuse and misunderstanding of reporting for instance p-values alone.publishedVersio

    UK B.1.1.7 variant exhibits increased respiratory replication and shedding in nonhuman primates.

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    The continuing emergence of SARS-CoV-2 variants calls for regular assessment to identify differences in viral replication, shedding and associated disease. In this study, African green monkeys were infected intranasally with either a contemporary D614G or the UK B.1.1.7 variant. Both variants caused mild respiratory disease with no significant differences in clinical presentation. Significantly higher levels of viral RNA and infectious virus were found in upper and lower respiratory tract samples and tissues from B.1.1.7 infected animals. Interestingly, D614G infected animals showed significantly higher levels of viral RNA and infectious virus in rectal swabs and gastrointestinal tract tissues. Our results indicate that B.1.1.7 infection in African green monkeys is associated with increased respiratory replication and shedding but no disease enhancement similar to human B.1.1.7 cases. ONE-SENTENCE SUMMARY: UK B.1.1.7 infection of African green monkeys exhibits increased respiratory replication and shedding but no disease enhancement

    Characterization of the Moraxella catarrhalis uspA1 and uspA2 Genes and Their Encoded Products

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    The uspA1 and uspA2 genes of M. catarrhalis O35E encode two different surface-exposed proteins which were previously shown to share a 140-amino-acid region with 93% identity (C. Aebi, I. Maciver, J. L. Latimer, L. D. Cope, M. K. Stevens, S. E. Thomas, G. H. McCracken, Jr., and E. J. Hansen, Infect. Immun. 65:4367–4377, 1997). The N-terminal amino acid sequences of the mature forms of both UspA1 and UspA2 from strain O35E were determined after enzymatic treatment to remove the N-terminal pyroglutamyl residue that had blocked Edman degradation. Mass spectrometric analysis indicated that the molecular mass of UspA1 from M. catarrhalis O35E was 83,500 ± 116 Da. Nucleotide sequence analysis of the uspA1 and uspA2 genes from three other M. catarrhalis strains (TTA24, ATCC 25238, and V1171) revealed that the encoded protein products were very similar to those from strain O35E. Western blot analysis was used to confirm that each of these three strains of M. catarrhalis expressed both UspA1 and UspA2 proteins. Several different and repetitive amino acid motifs were present in both UspA1 and UspA2 from these four strains, and some of these were predicted to form coiled coils. Linear DNA templates were used in an in vitro transcription-translation system to determine the sizes of the monomeric forms of the UspA1 and UspA2 proteins from strains O35E and TTA24

    Mathematical treatment of adiabatic fast passage pulses for the computation of nuclear spin relaxation rates in proteins with conformational exchange

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    Although originally designed for broadband inversion and decoupling in NMR spectroscopy, recent methodological developments have introduced adiabatic fast passage (AFP) pulses into the field of protein dynamics. AFP pulses employ a frequency sweep, and have not only superior inversion properties with respect to offset effects, but they are also easily implemented into a pulse sequence. As magnetization is dragged from the +z to the −z direction, Larmor precession is impeded since magnetization becomes spin-locked, which is a potentially useful feature for the investigation of microsecond to millisecond dynamics. A major drawback of these pulses as theoretical prediction is concerned, however, results from their time-dependent offset: simulations of spin density matrices under the influence of a time-dependent Hamiltonian with non-commuting elements are costly in terms of computational time, rendering data analysis impracticable. In this paper we suggest several ways to reduce the computational time without compromising accuracy with respect to effects such as cross-correlated relaxation and modulation of the chemical shift
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