112 research outputs found

    Science requirements and feasibility/design studies of a very-high-altitude aircraft for atmospheric research

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    The advantages and shortcomings of currently available aircraft for use in very high altitude missions to study such problems as polar ozone or stratosphere-troposphere exchange pose the question of whether to develop advanced aircraft for atmospheric research. To answer this question, NASA conducted a workshop to determine science needs and feasibility/design studies to assess whether and how those needs could be met. It was determined that there was a need for an aircraft that could cruise at an altitude of 30 km with a range of 6,000 miles with vertical profiling down to 10 km and back at remote points and carry a payload of 3,000 lbs

    Reframing commitment in authentic leadership: Untangling relationship–outcome processes

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    Affective organizational commitment is theorized and empirically tested as a key mediator between authentic leadership and desirable employee outcomes. The results of a two-wave survey of 830 business people in Australia support a serial mediation model of authentic leadership efficacy. Followers\u27 perceptions of authentic leadership behavior influence their personal identification and affect-based trust in the leader, which in turn are mediated by affective organizational commitment to positively influence their work engagement and job satisfaction. These findings reinforce previous work that positions personal identification and affect-based trust as the two primary mediating mechanisms of authentic leadership. This paper extends prior research by demonstrating the important role of followers\u27 affective bonds with their organization in the operation of authentic leadership, moving beyond the dyad in our understanding of follower outcomes

    Reframing commitment in authentic leadership: Untangling relationship–outcome processes

    Get PDF
    Affective organizational commitment is theorized and empirically tested as a key mediator between authentic leadership and desirable employee outcomes. The results of a two-wave survey of 830 business people in Australia support a serial mediation model of authentic leadership efficacy. Followers\u27 perceptions of authentic leadership behavior influence their personal identification and affect-based trust in the leader, which in turn are mediated by affective organizational commitment to positively influence their work engagement and job satisfaction. These findings reinforce previous work that positions personal identification and affect-based trust as the two primary mediating mechanisms of authentic leadership. This paper extends prior research by demonstrating the important role of followers\u27 affective bonds with their organization in the operation of authentic leadership, moving beyond the dyad in our understanding of follower outcomes

    Student Information Use During the COVID-19 Pandemic

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    Since early 2020, life for students has changed tremendously. It has been a time of stress, turmoil, and trauma for students. Researchers from a large Midwestern university wanted to determine how student information use has changed during the COVID-19 pandemic. This paper examines the results of a mixed-methods study undertaken in 2021 using surveys and follow-up focus groups to determine if and how student information use has changed. To answer this, we explored student use of news sources, social media sources, political affiliations, and information responses, coupled with to what extent these factors demonstrate or impact potential changes in information use. We also addressed changes in the frequency of use, as well as the types of resources consulted, pertaining to information use of traditional and social media sources

    Development and Validation of the Holistic Cognition Scale

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    This paper introduces a new scale to measure cognitive cultural differences, drawing on the theory of analytic versus holistic thought. Examining culture from a cognitive perspective is a challenge to traditional values-based approaches. Existing measures based on this framework are methodologically problematic and warrant renewal. This paper presents development and validation studies for a new instrument that measures analytic versus holistic cognitive tendencies at the individual level. The scale assesses four previously established dimensions: attention, causality, contradiction, and change. The present work follows well-established scale development protocols and the results show that the 16-item Holistic Cognition Scale (HCS) is a valid and reliable measure of analytic versus holistic thought. Three new studies with four unique samples (N = 41; 272; 454; and 454) provide evidence to support the content validity, reliability, and factor structure of the new instrument, as well as its convergent, discriminant, and concurrent validity against comparable constructs. Convergent validity is established against measures of compromise, intuition, complexity, and collectivism; predictive validity is established against Hofstede’s (1980) five cultural value dimensions; and discriminant validity is established using the average variance extracted from a confirmatory factor analysis. The new HCS is an improvement over previous attempts with a balanced number of forward- and reverse-scored items, superior reliability, less redundancy, and stronger factor loadings

    Concentrating light in Cu(In,Ga)Se2 solar cells

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    Light concentration has proven beneficial for solar cells, most notably for highly efficient but expensive absorber materials using high concentrations and large scale optics. Here, we investigate the light concentration for cost- efficient thin-film solar cells that show nano- or microtextured absorbers. Our absorber material of choice is Cu(In,Ga)Se2 (CIGSe), which has a proven stabilized record efficiency of 22.6% and which—despite being a polycrystalline thin-film material—is very tolerant to environmental influences. Taking a nanoscale approach, we concentrate light in the CIGSe absorber layer by integrating photonic nanostructures made from dielectric materials. The dielectric nanostructures give rise to resonant modes and field localization in their vicinity. Thus, when inserted inside or adjacent to the absorber layer, absorption and efficiency enhancement are observed. In contrast to this internal absorption enhancement, external enhancement is exploited in the microscaled approach: mm-sized lenses can be used to concentrate light onto CIGSe solar cells with lateral dimensions reduced down to the micrometer range. These micro solar cells come with the benefit of improved heat dissipation compared with the large scale concentrators and promise compact high-efficiency devices. Both approaches of light concentration allow for reduction in material consumption by restricting the absorber dimension either vertically (ultrathin absorbers for dielectric nanostructures) or horizontally (microabsorbers for concentrating lenses) and have significant potential for efficiency enhancement

    Immunomodulatory oligonucleotide IMT504: effects on mesenchymal stem cells as a first-in-class immunoprotective/immunoregenerative therapy

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    The immune responses of humans and animals to insults (i.e., infections, traumas, tumoral transformation and radiation) are based on an intricate network of cells and chemical messengers. Abnormally high inflammation immediately after insult or abnormally prolonged pro-inflammatory stimuli bringing about chronic inflammation can lead to life-threatening or severely debilitating diseases. Mesenchymal stem cell (MSC) transplant has proved to be an effective therapy in preclinical studies which evaluated a vast diversity of inflammatory conditions. MSCs lead to resolution of inflammation, preparation for regeneration and actual regeneration, and then ultimate return to normal baseline or homeostasis. However, in clinical trials of transplanted MSCs, the expectations of great medical benefit have not yet been fulfilled. As a practical alternative to MSC transplant, a synthetic drug with the capacity to boost endogenous MSC expansion and/or activation may also be effective. Regarding this, IMT504, the prototype of a major class of immunomodulatory oligonucleotides, induces in vivo expansion of MSCs, resulting in a marked improvement in preclinical models of neuropathic pain, osteoporosis, diabetes and sepsis. IMT504 is easily manufactured and has an excellent preclinical safety record. In the small number of patients studied thus far, IMT504 has been well-tolerated, even at very high dosage. Further clinical investigation is necessary to demonstrate the utility of IMT504 for resolution of inflammation and regeneration in a broad array of human diseases that would likely benefit from an immunoprotective/immunoregenerative therapy.Fil: Zorzopulos, Jorge. Immunotech; ArgentinaFil: Opal, Steven M.. Memorial Hospital of Rhode Island; Estados Unidos. Alpert Medical School; Estados UnidosFil: Hernando Insúa, Andrés. Fundación Pablo Cassara; ArgentinaFil: Rodriguez, Juan M.. Fundación Pablo Cassara; ArgentinaFil: Elías, Fernanda. Fundación Pablo Cassara; ArgentinaFil: Fló, Juan. Immunotech; ArgentinaFil: López, Ricardo A.. Imunotech; ArgentinaFil: Chasseing, Norma Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Lux, Victoria Adela R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Coronel, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Franco, Raul. Imunotech; ArgentinaFil: Montaner, Alejandro D. Fundación Pablo Cassara; ArgentinaFil: Horn, David L. David Horn Llc; Estados Unido

    NASA Probe Study Report: Farside Array for Radio Science Investigations of the Dark ages and Exoplanets (FARSIDE)

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    This is the final report submitted to NASA for a Probe-class concept study of the "Farside Array for Radio Science Investigations of the Dark ages and Exoplanets" (FARSIDE), a low radio frequency interferometric array on the farside of the Moon. The design study focused on the instrument, a deployment rover, the lander and base station, and delivered an architecture broadly consistent with the requirements for a Probe mission. This notional architecture consists of 128 dipole antennas deployed across a 10 km area by a rover, and tethered to a base station for central processing, power and data transmission to the Lunar Gateway, or an alternative relay satellite. FARSIDE would provide the capability to image the entire sky each minute in 1400 channels spanning frequencies from 150 kHz to 40 MHz, extending down two orders of magnitude below bands accessible to ground-based radio astronomy. The lunar farside can simultaneously provide isolation from terrestrial radio frequency interference, auroral kilometric radiation, and plasma noise from the solar wind. This would enable near-continuous monitoring of the nearest stellar systems in the search for the radio signatures of coronal mass ejections and energetic particle events, and would also detect the magnetospheres for the nearest candidate habitable exoplanets. Simultaneously, FARSIDE would be used to characterize similar activity in our own solar system, from the Sun to the outer planets. Through precision calibration via an orbiting beacon, and exquisite foreground characterization, FARSIDE would also measure the Dark Ages global 21-cm signal at redshifts from 50-100. It will also be a pathfinder for a larger 21-cm power spectrum instrument by carefully measuring the foreground with high dynamic range

    Kvasir-Capsule, a video capsule endoscopy dataset

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    Artificial intelligence (AI) is predicted to have profound effects on the future of video capsule endoscopy (VCE) technology. The potential lies in improving anomaly detection while reducing manual labour. Existing work demonstrates the promising benefits of AI-based computer-assisted diagnosis systems for VCE. They also show great potential for improvements to achieve even better results. Also, medical data is often sparse and unavailable to the research community, and qualified medical personnel rarely have time for the tedious labelling work. We present Kvasir-Capsule, a large VCE dataset collected from examinations at a Norwegian Hospital. Kvasir-Capsule consists of 117 videos which can be used to extract a total of 4,741,504 image frames. We have labelled and medically verified 47,238 frames with a bounding box around findings from 14 different classes. In addition to these labelled images, there are 4,694,266 unlabelled frames included in the dataset. The Kvasir-Capsule dataset can play a valuable role in developing better algorithms in order to reach true potential of VCE technology
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