355 research outputs found

    Gas-phase broadband spectroscopy using active sources: progress, status, and applications

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    Broadband spectroscopy is an invaluable tool for measuring multiple gas-phase species simultaneously. In this work we review basic techniques, implementations, and current applications for broadband spectroscopy. We discuss components of broadband spectroscopy including light sources, absorption cells, and detection methods and then discuss specific combinations of these components in commonly used techniques. We finish this review by discussing potential future advances in techniques and applications of broadband spectroscopy

    Motivation, optimal experience and flow in first year computing science.

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    We examine the concept of motivation from the perspective of Self Determination Theory and give a brief overview of relevant results. We also consider the optimal state known as Flow and give an account of its conceptualisation in the theory due to Csikszentmihalyi. After discussion of ways in which these concepts can be measured, we describe a set of preliminary studies that investigate motivation and flow in the context of a first year computing class. We analyse student responses to enquiries about perceptions of motivation and flow experiences and look at links between them. We also discuss intrinsic motivation within the subject

    The OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS): Spectral Maps of the Asteroid Bennu

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    The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) is a point spectrometer covering the spectral range of 0.4 to 4.3 microns (25,000-2300 cm-1). Its primary purpose is to map the surface composition of the asteroid Bennu, the target asteroid of the OSIRIS-REx asteroid sample return mission. The information it returns will help guide the selection of the sample site. It will also provide global context for the sample and high spatial resolution spectra that can be related to spatially unresolved terrestrial observations of asteroids. It is a compact, low-mass (17.8 kg), power efficient (8.8 W average), and robust instrument with the sensitivity needed to detect a 5% spectral absorption feature on a very dark surface (3% reflectance) in the inner solar system (0.89-1.35 AU). It, in combination with the other instruments on the OSIRIS-REx Mission, will provide an unprecedented view of an asteroid's surface.Comment: 14 figures, 3 tables, Space Science Reviews, submitte

    Associations Between Community Nutrition Environments and Early Care and Education Classroom Nutrition Practices

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    Poor child diet is influenced by nutrition environments surrounding schools and homes; influence of these environments on Early Care and Education (ECE) settings is not understood. The purpose of this study was to determine associations between community nutrition environments and ECE classroom nutrition practices, by ECE context [Head Starts, community-based childcare (CBCs), and family child care homes (FCCHs)]. Conclusions: Contrary to studies in residential areas and schools, nutrition environments were not related to nutrition practices in ECEs. This suggests that ECEs may serve as protective microenvironments supporting health for children more vulnerable to the health environments of their nearby residing communities. Supporting health practices for ECEs may be achieved most effectively through within-center intervention and policy

    In-Air Evoked Potential Audiometry of Grey Seals (Halichoerus grypus) from the North and Baltic Seas

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    In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1–20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4–20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal

    Relationships between proximity to grocery stores and Oklahoma Early Care and Education classroom nutrition practices

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    The study purpose was to determine associations between proximity to grocery stores and Early Care and Education programs’ (i.e., ECEs) classroom nutrition practices and barriers, by ECE context (Head Start, community-based childcare [CBC], and family child care homes [FCCHs]). A statewide cross-sectional survey was implemented in Oklahoma ECEs. Directors reported classroom nutrition practices with the Nutrition and Physical Activity Self-Assessment tool, and barriers to implementation. Locations of 457 grocery stores statewide were determined by in-person audit. Geocoded ECEs were considered within a “low proximity” area if no grocery stores were available within a 0.25-mile radius for urban, or 10-mile radius for rural, ECEs. From November 2019 to February 2020, 54 Head Starts, 159 CBCs, and 160 FCCHs participated. 31.0 % were considered as low proximity. Head Starts demonstrated the highest classroom nutrition scores for mealtime practices, and nutrition education and policy. While proximity to grocery stores was not related to classroom nutrition practices for any ECE context (p \u3e 0.05), FCCHs located within a low proximity area reported barriers to implementing those practices more often compared to FCCHs in an area within accessible proximity of grocery store. Thus, proximity to grocery stores was related to barriers in FCCHs only; those provider’s experiences and perceptions may be most susceptible to influence of the community nutrition environment, compared to other ECE contexts. Contrary to studies in residential areas and schools, nutrition environments were not related to nutrition practices in ECEs. ECEs may serve as protective micro-environments supporting health for children residing in nearby low-access communities
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