1,844 research outputs found

    Calibration of the visible and near-infrared channels of the LANDSAT-5 Thematic Mapper using high-altitude aircraft measurements

    Get PDF
    Visible near-infrared sensors mounted on operational satellites now in use do not have on-board full aperture absolute calibration devices. One means of establishing an in-orbit calibration for a satellite sensor is to make simultaneous measurements of a bright, uniform scene along the satellite view vector from a calibrated instrument on board a high altitude aircraft. In the work reported here, aircraft data were recorded over White Sands, New Mexico at satellite overpass time for the LANDSAT-5 Thematic Mapper (TM). A comparison of the coincident aircraft and orbiting satellite data showed the radiometric gain for TM channel 1 had degraded 4.7 percent by August 28, 1985; gains for TM channels 2 and 3 were within 1 percent of prelaunch values

    COVID-19 Impacts at a Small Mid-Atlantic Liberal-Arts College with Implications for STEM Education

    Get PDF
    During the COVID-19 pandemic, with very little preparation and within a brief span of 48 hours, the Wesley College STEM faculty and students triaged into a remote-only form of instruction. Wesley College STEM student COVID-19 impact surveys showed underlying gaps in economic equity, increased family responsibilities, struggles to stay motivated, social isolation, and higher levels of psychological stress. Yet, the crisis demonstrated new ways in which technology can be harnessed and allowed STEM students to reconsider how jobs and skills should be aligned. A STEM faculty COVID-19 check-in survey and interview responses revealed a quick realization that faculty could not rely solely on Wesley’s Jenzebar learning management system (MyWesley). To engage their students and to create a supportive learning environment, STEM faculty sought new strategies and approaches for a diverse set of STEM learners. For synchronous e-teaching, the faculty used the Microsoft-Teams and the Zoom video conferencing platforms. Faculty only adopted MyWesley to execute dedicated asynchronous tasks (laboratory assignments, reports, exams). The STEM students were overwhelmingly positive about STEM faculty availability during the crisis. Still, both faculty and students indicated a much stronger preference for the face-to-face delivery of their course content via a traditional classroom setting

    Epidemiology of depression with psychotic experiences and its association with chronic physical conditions in 47 low- and middle-income countries

    Get PDF
    BackgroundThe co-existence of depression and psychotic experiences (PEs) is associated with more pronounced adverse health outcomes compared to depression alone. However, data on its prevalence and correlates are lacking in the general adult population, and there is no published data on its association with chronic physical conditions.MethodCross-sectional, community-based data from 201 337 adults aged ⩾18 years from 47 low- and middle-income countries from the World Health Survey were analyzed. The presence of past 12-month PE and DSM-IV depression was assessed with the Composite International Diagnostic Interview (CIDI). Information on six chronic medical conditions (chronic back pain, edentulism, arthritis, angina, asthma, diabetes) were obtained by self-report. Multivariable logistic regression analysis was performed.ResultsThe crude overall prevalence of co-morbid depression/PEs was 2.5% [95% confidence interval (CI) 2.3–2.7%], with the age- and sex-adjusted prevalence ranging from 0.1% (Sri Lanka, Vietnam) to 9.03% (Brazil). Younger age, urban setting, current smoking, alcohol consumption, and anxiety were significant correlates of co-existing depression/PEs. Co-occurring depression/PEs was associated with significantly higher odds for arthritis, angina, and diabetes beyond that of depression alone after adjusting for sociodemographics, anxiety, and country, with odds ratios (depression/PEs v. depression only) being: arthritis 1.30 (95% CI 1.07–1.59, p = 0.0086); angina 1.40 (95% CI 1.18–1.67, p = 0.0002); diabetes 1.65 (95% CI 1.21–2.26, p = 0.0017).ConclusionsThe prevalence of co-existing depression/PEs was non-negligible in most countries. Our study suggests that when depression/PE or a chronic condition (e.g. arthritis, angina, diabetes) is detected, screening for the other may be important to improve clinical outcomes.</jats:sec

    Domain Wall Pinning by Step-Like Thickness Change in Magnetic Thin Film

    Get PDF
    A thin-film element with a steplike thickness change has been fabricated to investigate experimentally a pinning effect of domain walls by a shape control of thin-film devices. Using a Kerr microscope, domain observation has been done to measure pinning characteristics of the element. It has been shown that 40% steplike thickness change of the film thickness can realize a wall pinning, and a pinning field of 2.53 Oe is obtained. The pinning field increases with increasing steplike thickness change ratio

    Progress and Trends in Artificial Silk Spinning: A Systematic Review

    Get PDF
    More than 400 million years of natural selection acting throughout the arthropoda has resulted in highly specialized and energetically efficient processes to produce protein-based fibers with properties that are a source of inspiration for all. As a result, for over 80 years researchers have been inspired by natural silk production in their attempts to spin artificial silks. While significant progress has been made, with fibers now regularly outperforming silkworm silks, surpassing the properties of superior silks, such as spider dragline, is still an area of considerable effort. This review provides an overview of the different approaches for artificial silk fiber spinning and compares all published fiber properties to date which has identified future trends and challenges on the road towards replicating high performance silks

    Infrared magneto-optical properties of (III,Mn)V ferromagetic semiconductors

    Full text link
    We present a theoretical study of the infrared magneto-optical properties of ferromagnetic (III,Mn)V semiconductors. Our analysis combines the kinetic exchange model for (III,Mn)V ferromagnetism with Kubo linear response theory and Born approximation estimates for the effect of disorder on the valence band quasiparticles. We predict a prominent feature in the ac-Hall conductivity at a frequency that varies over the range from 200 to 400 meV, depending on Mn and carrier densities, and is associated with transitions between heavy-hole and light-hole bands. In its zero frequency limit, our Hall conductivity reduces to the k\vec k-space Berry's phase value predicted by a recent theory of the anomalous Hall effect that is able to account quantitatively for experiment. We compute theoretical estimates for magnetic circular dichroism, Faraday rotation, and Kerr effect parameters as a function of Mn concentration and free carrier density. The mid-infrared response feature is present in each of these magneto-optical effects.Comment: 11 pages, 5 figure

    Population prevalence of edentulism and its association with depression and self-rated health

    Get PDF
    Edentulism is associated with various adverse health outcomes but treatment options in low- and middle-income countries (LMICs) are limited. Data on its prevalence and its effect on mental health and overall-health is lacking, especially from LMICs. Self-reported data on complete edentulism obtained by standardized questionnaires on 201,953 adults aged ≥18 years from 50 countries which participated in the World Health Survey (WHS) 2002-2004 were analyzed. Age and sex-standarized edentulism prevalence ranged from 0.1% (95% CI = 0.0-0.3) (Myanmar) to 14.5% (95% CI = 13.1-15.9) (Zimbabwe), and 2.1% (95% CI = 1.5-3.0) (Ghana) to 32.3% (95% CI = 29.0-35.8) (Brazil) in the younger and older age groups respectively. Edentulism was significantly associated with depression (OR 1.57, 95% CI = 1.23-2.00) and poor self-rated health (OR 1.38, 95% CI = 1.03-1.83) in the younger group with no significant associations in the older age group. Our findings highlight the edentulism-related health loss in younger persons from LMICs. The relative burden of edentulism is likely to grow as populations age and live longer. Given its life-long nature and common risk factors with other NCDs, edentulism surveillance and prevention should be an integral part of the global agenda of NCD control

    Multiple opsins in a reef-building coral, Acropora millepora

    Get PDF
    Opsins, light-sensitive G protein-coupled receptors, have been identified in corals but their properties are largely unknown. Here, we identified six opsin genes (acropsins 1–6) from a coral species Acropora millepora, including three novel opsins (acropsins 4–6), and successfully characterized the properties of four out of the six acropsins. Acropsins 1 and 6 exhibited light-dependent cAMP increases in cultured cells, suggesting that the acropsins could light-dependently activate Gs-type G protein like the box jellyfish opsin from the same opsin group. Spectral sensitivity curves having the maximum sensitivities at ~ 472 nm and ~ 476 nm were estimated for acropsins 1 and 6, respectively, based on the light wavelength-dependent cAMP increases in these opsins-expressing cells (heterologous action spectroscopy). Acropsin 2 belonging to the same group as acropsins 1 and 6 did not induce light-dependent cAMP or Ca2+ changes. We then successfully estimated the acropsin 2 spectral sensitivity curve having its maximum value at ~ 471 nm with its chimera mutant which possessed the third cytoplasmic loop of the Gs-coupled jellyfish opsin. Acropsin 4 categorized as another group light-dependently induced intracellular Ca2+ increases but not cAMP changes. Our results uncovered that the Acropora coral possesses multiple opsins coupling two distinct cascades, cyclic nucleotide and Ca2+signaling light-dependently
    corecore