711 research outputs found
Far infrared supplement. Third edition: Catalog of infrared observations (lambda greater than or equal to 4.6 micrometers)
The Far Infrared Supplement contains a subset of the data in the full Catalog of Infrared Observations (all observations at wavelengths greater than 4.6 microns). The Catalog of Infrared Observations (CIO), NASA RP-1294, is a compilation of infrared astronomical observational data obtained from an extensive literature search of scientific journals and major astronomical catalogs and surveys. The literature search is complete for years 1965 through 1990 in this third edition. The catalog contains about 210,000 observations of roughly 20,000 individual sources, and supporting appendices. The expanded third edition contains coded IRAS 4-band data for all CIO sources detected by IRAS. The appendices include an atlas of infrared source positions (also included in this volume), two bibliographies of catalog listings, and an atlas of infrared spectral ranges. The complete CIO database is available to qualified users in printed, microfiche, and magnetic tape formats
Library discovery through augmented reality: a game plan for academics
In order to create innovative pathways to services and resources, the authors propose placing a âgame-layerâ on top of the library, luring new patrons with the potential of playing an Alternate/Augmented Reality Game (ARG). Using both physical and virtual library space a variety of ânodesâ are created, drawing players to various library locales even regular patrons may be unfamiliar with and presenting them with story fragments and puzzles. Each node requires players to use library resources like databases and books, or engage library staff at known service points in order to move forward. Players contribute to the game itself in the form of puzzle solutions. Far more illustrative than a guided tour or required course/class, this library ARG encourages players to discover and utilize resources within the context of the game, generating fluency in library systems, places and platforms. But more importantly, the ARG invites a process of âmeta-level reflectionâ invaluable throughout a patronâs academic career
Internal Universes in Models of Homotopy Type Theory
We begin by recalling the essentially global character of universes in various models of homotopy type theory, which prevents a straightforward axiomatization of their properties using the internal language of the presheaf toposes from which these model are constructed. We get around this problem by extending the internal language with a modal operator for expressing properties of global elements. In this setting we show how to construct a universe that classifies the Cohen-Coquand-Huber-Mörtberg (CCHM) notion of fibration from their cubical sets model, starting from the assumption that the interval is tiny - a property that the interval in cubical sets does indeed have. This leads to an elementary axiomatization of that and related models of homotopy type theory within what we call crisp type theory
Mixing at Young Ages Reduces Fighting in Unacquainted Domestic Pigs
Under normal farming practices, piglets from different litters are often mixed around the time of weaning, and a high incidence of fighting and minor injuries often occur. The aim of this experiment was to determine the effect of age on the incidence of fighting in piglets mixed before weaning, at different ages between 5 and 26 days. We found no significant relationship between age and the likelihood that a pair of piglets would fight during the first 75 min after mixing. However, the duration of the first fight observed increased from 101±38 s at 5 days to 621±278 s at 26 days, mainly because of higher levels of unretaliated harassment and resting during the bouts. Younger pigs also showed 80% fewer injuries from the fighting. The results suggest some potential welfare advantage to allowing litters to mix at younger ages
Effects of a Meditation and Contemplative Practice Course on College Studentsâ Mindfulness, Self-Compassion, and Mental Health
Objectives: Mindfulness-based practices have been shown to be effective in reducing depression and anxiety among college students. Less is known about whether coursework incorporating contemplative practices has similar beneficial effects. This study sought to investigate the benefits of a course focusing on contemplative practices that included mindfulness-based practice inside and outside the classroom. Method: In Study 1, 42 students enrolled in Meditation and Contemplative Practice, a course taught through the Department of Classics, Philosophy, and Religious Studies, completed measures of mindfulness, self-compassion, depression, and anxiety at the beginning and end of the semester. In Study 2, 43 students in this course, and 65 students in an Introduction to World Religions course completed the same measures at the beginning and end of the semester. In Study 3, 15 students enrolled in the contemplative practices course completed a pre-test, a post-test, and a follow-up assessment six weeks later. Results: Across all three studies mindfulness and self-compassion rose over the course of the semester. In Study 1, anxiety significantly decreased. In Study 2, those in the religious studies course did not experience increased mindfulness or self-compassion over the course of the semester. Furthermore, there were significant interactions indicating that the religion students increased in depression and anxiety over the course of the semester while those in the contemplative practices class decreased. Study 3 indicated that the gains made during the semester continued after the course was over. Conclusions: Results indicate that coursework on contemplative practices is beneficial to the mental health of college students
Hypo-Osmotic Stress and Pore-Forming Toxins Adjust the Lipid Order in Sheep Red Blood Cell Membranes
Lipid ordering in cell membranes has been increasingly recognized as an important factor in establishing and regulating a large variety of biological functions. Multiple investigations into lipid organization focused on assessing ordering from temperature-induced phase transitions, which are often well outside the physiological range. However, particular stresses elicited by environmental factors, such as hypo-osmotic stress or protein insertion into membranes, with respect to changes in lipid status and ordering at constant temperature are insufficiently described. To fill these gaps in our knowledge, we exploited the well-established ability of environmentally sensitive membrane probes to detect intramembrane changes at the molecular level. Our steady state fluorescence spectroscopy experiments focused on assessing changes in optical responses of Laurdan and diphenylhexatriene upon exposure of red blood cells to hypo-osmotic stress and pore-forming toxins at room temperature. We verified our utilized experimental systems by a direct comparison of the results with prior reports on artificial membranes and cholesterol-depleted membranes undergoing temperature changes. The significant changes observed in the lipid order after exposure to hypo-osmotic stress or pore-forming toxins resembled phase transitions of lipids in membranes, which we explained by considering the short-range interactions between membrane components and the hydrophobic mismatch between membrane thickness and inserted proteins. Our results suggest that measurements of optical responses from the membrane probes constitute an appropriate method for assessing the status of lipids and phase transitions in target membranes exposed to mechanical stresses or upon the insertion of transmembrane proteins
Symptomatic Infundibulopelvic Dysgenesis in an Adolescent
Infundibulopelvic dysgenesis is a rare condition characterized by congenital malformation of the pelvicalyceal system. We present the case of an 18-year-old boy with chronic intermittent right flank pain and cystic dilation with parenchymal thinning on ultrasonography. The left kidney was normal. The patient denied dysuria, constipation, and history of UTIs or renal calculi. Cystoscopy with retrograde pyelogram showed marked stenosis of the right pelvicalyceal system and anatomy unfavorable to stenting. The patientâs symptoms were unresponsive to conservative management. Reconstruction of the right collecting system was unsuccessful and a simple nephrectomy was performed, which led to complete resolution of his symptoms
Structure of Large NitrateâWater Clusters at Ambient Temperatures: Simulations with Effective Fragment Potentials and Force Fields with Implications for Atmospheric Chemistry
Structural properties of large NO3â·(H2O)n (n = 15â500) clusters are studied by Monte Carlo simulations using effective fragment potentials (EFPs) and by classical molecular dynamics simulations using a polarizable empirical force field. The simulation results are analyzed with a focus on the description of hydrogen bonding and solvation in the clusters. In addition, a comparison between the electronic structure based EFP and the classical force field description of the 32 water cluster system is presented. The EFP simulations, which focused on the cases of n = 15 and 32, show an internal, fully solvated structure and a âsurface adsorbedâ structure for the 32 water cluster at 300 K, with the latter configuration being more probable. The internal solvated structure and the âsurface adsorbedâ structure differ considerably in their hydrogen bonding coordination numbers. The force field based simulations agree qualitatively with these results, and the local geometry of NO3â and solvation at the surface-adsorbed site in the force field simulations are similar to those predicted using EFPs. Differences and similarities between the description of hydrogen bonding of the anion in the two approaches are discussed. Extensive classical force field based simulations at 250 K predict that long time scale stability of âinternalâ NO3â, which is characteristic of extended bulk aqueous interfaces, emerges only for n \u3e 300. Ab initio MĂžllerâPlesset perturbation theory is used to test the geometries of selected surface and interior anions for n = 32, and the results are compared to the EFP and MD simulations. Qualitatively, all approaches agree that surface structures are preferred over the interior structures for clusters of this size. The relatively large aqueous clusters of NO3â studied here are of comparable size to clusters that lead to new particle formation in air. Nitrate ions on the surface of such clusters may have significantly different photochemistry than the internal species. The possible implications of surface-adsorbed nitrate ions for atmospheric chemistry are discussed
Disrupted glucose homeostasis and skeletal muscle-specific glucose uptake in an exocyst knockout mouse model
Skeletal muscle is responsible for the majority of glucose disposal following meals, and this is achieved by insulin-mediated trafficking of glucose transporter type 4 (GLUT4) to the cell membrane. The eight-protein exocyst trafficking complex facilitates targeted docking of membrane-bound vesicles, a process underlying the regulated delivery of fuel transporters. We previously demonstrated the role of exocyst subunit EXOC5 in insulin-stimulated GLUT4 exocytosis and glucose uptake in cultured rat skeletal myoblasts. However, the in vivo role of EXOC5 in skeletal muscle remains unclear. Using mice with inducible, skeletal muscle-specific knockout of exocyst subunit EXOC5 (Exoc5-SMKO), we examined how muscle-specific disruption of the exocyst would affect glucose homeostasis in vivo. We found that both male and female Exoc5-SMKO mice displayed elevated fasting glucose levels. Additionally, male Exoc5-SMKO mice had impaired glucose tolerance and lower serum insulin levels. Using indirect calorimetry, we observed that male Exoc5-SMKO mice have a reduced respiratory exchange ratio during the light period and lower energy expenditure. Using the hyperinsulinemic-euglycemic clamp method, we further showed that insulin-stimulated skeletal muscle glucose uptake is reduced in Exoc5-SMKO males compared to wild-type controls. Overall, our findings indicate that EXOC5 and the exocyst are necessary for insulin-stimulated glucose uptake in skeletal muscle and regulate glucose homeostasis in vivo
Reproductive Success of Eastern Bluebirds (Siala sialis) on Suburban Golf Courses
Understanding the role of green space in urbanâsuburban landscapes is becoming critical for bird conservation because of rampant habitat loss and conversion. Although not natural habitat, golf courses could play a role in bird conservation if they support breeding populations of some native species, yet scientists remain skeptical. In 2003â2009, we measured reproduction of Eastern Bluebirds (Siala sialis) in Virginia on golf courses and surrounding reference habitats, of the type that would have been present had golf courses not been developed on these sites (e.g., recreational parks, cemeteries, agriculture land, and college campus). We monitored \u3e650 nest boxes and 2,255 nest attempts (n = 1,363 golf course, n = 892 reference site). We used an information-theoretic modeling approach to evaluate whether conditions on golf courses affected timing of breeding, investment, or nest productivity compared with nearby reference sites. We found that Eastern Bluebirds breeding on golf courses reproduced as well as those breeding in other disturbed habitats. Habitat type had no effect on initial reproductive investment, including date of clutch initiation or clutch size ( = 4 eggs). During incubation and hatching, eggs in nests on golf courses had higher hatching rates (80%) and brood sizes ( = 4.0 nestlings brood-1) than nests on reference sites (75% hatching rate; = 3.8 nestlings brood-1). Mortality of older nestlings was also lower on golf courses and, on average, golf course nests produced 0.3 more fledglings than nests on reference sites. Thus, within a matrix of human-dominated habitats, golf courses may support productive populations of some avian species that can tolerate moderate levels of disturbance, like Eastern Bluebirds
- âŠ