3,255 research outputs found

    An Investigation of Digital Literacy Needs of Students

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    This paper describes the results of a survey of teaching faculty at a medium-sized university in the southeastern United States to determine core curriculum items that should be taught to ensure that graduates have the capabilities and skills to fully participate in the digital society. There was considerable agreement between the colleges regarding the importance of twenty aspects of digital literacy. Application skills continued to be viewed as very relevant. However, our findings also show the need for a greater focus on information literacy skills that go beyond the focus of the current one-credit-hour software applications course designed to achieve computer application literacy. A case can be made for additional topics to be included in the curriculum common to all students such as ethics, security and privacy, and how to validate the relevance and usefulness of data. The study also highlights the need for discipline-specific topics to be embedded in subject-knowledge courses

    Study of aluminoborane compound AlB_4H_(11) for hydrogen storage

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    Aluminoborane compounds AlB_4H_(11), AlB_5H_(12), and AlB_6H_(13) were reported by Himpsl and Bond in 1981, but they have eluded the attention of the worldwide hydrogen storage research community for more than a quarter of a century. These aluminoborane compounds have very attractive properties for hydrogen storage: high hydrogen capacity (i.e., 13.5, 12.9, and 12.4 wt % H, respectively) and attractive hydrogen desorption temperature (i.e., AlB_4H_(11) decomposes at ~125 °C). We have synthesized AlB_4H_(11) and studied its thermal desorption behavior using temperature-programmed desorption with mass spectrometry, gas volumetric (Sieverts) measurement, infrared (IR) spectroscopy, and solid state nuclear magnetic resonance (NMR). Rehydrogenation of hydrogen-desorbed products was performed and encouraging evidence of at least partial reversibility for hydrogenation at relatively mild conditions is observed. Our chemical analysis indicates that the formula for the compound is closer to AlB_4H_(12) than AlB_4H_(11)

    Mapping Valley Bottom Confinement at the Network Scale

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    In this article, we demonstrate the application of a continuous confinement metric across entire river networks. Confinement is a useful metric for characterizing and discriminating valley setting. At the reach scale, valley bottom confinement is measured and quantified as the ratio of the length of channel confined on either bank by a confining margin divided by the reach length. The valley bottom is occupied by the contemporary floodplain and/or its channel(s); confining margins can be any landform or feature that makes up the valley bottom margin, such as bedrock hillslopes, terraces, fans, or anthropogenic features such as stopbanks or constructed levees. To test the reliability of calculating confinement across entire networks, we applied our geoprocessing scripts across four physiographically distinct watersheds of the Pacific Northwest, USA using freely available national datasets. Comparison of manually digitized and mapped with modeled calculations of confinement revealed that roughly one‐third of reaches were equivalent and about two‐thirds of the sites differ by less than ±15%. A sensitivity analysis found that a 500 m reach segmentation length produced reasonable agreement with manual, categorical, expert‐derived analysis of confinement. Confinement accuracy can be improved (c. 4% to 17% gains) using a more accurately mapped valley bottom and channel position (i.e. with higher‐resolution model inputs). This is particularly important when differentiating rivers in the partly confined valley setting. However, at the watershed scale, patterns derived from mapping confinement are not fundamentally different, making this a reasonably accurate and rapid technique for analysis and measurement of confinement across broad spatial extents

    Discovery and Validation of Kepler-452b: A 1.6-Re Super Earth Exoplanet in the Habitable Zone of a G2 Star

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    We report on the discovery and validation of Kepler-452b, a transiting planet identified by a search through the 4 years of data collected by NASA's Kepler Mission. This possibly rocky 1.630.20+0.23^{+0.23}_{-0.20} R_\oplus planet orbits its G2 host star every 384.8430.012+0.007^{+0.007}_{0.012} days, the longest orbital period for a small (Rp_p < 2 R_\oplus) transiting exoplanet to date. The likelihood that this planet has a rocky composition lies between 49% and 62%. The star has an effective temperature of 5757±\pm85 K and a log g of 4.32±\pm0.09. At a mean orbital separation of 1.0460.015+0.019^{+0.019}_{-0.015} AU, this small planet is well within the optimistic habitable zone of its star (recent Venus/early Mars), experiencing only 10% more flux than Earth receives from the Sun today, and slightly outside the conservative habitable zone (runaway greenhouse/maximum greenhouse). The star is slightly larger and older than the Sun, with a present radius of 1.110.09+0.15^{+0.15}_{-0.09} R_\odot and an estimated age of 6 Gyr. Thus, Kepler-452b has likely always been in the habitable zone and should remain there for another 3 Gyr.Comment: 19 pages, 16 figure

    The effect of matrix metalloproteinase 2 and matrix metalloproteinase 2/9 deletion in experimental post-thrombotic vein wall remodeling

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    BackgroundVein wall fibrotic injury following deep venous thrombosis (VT) is associated with elevated matrix metalloproteinases (MMPs). Whether and by what mechanism MMP2 contributes to vein wall remodeling after VT is unknown.MethodsStasis VT was produced by ligation of the inferior vena cava and tissue was harvested at 2, 8, and 21 days in MMP2 -/- and genetic wild type (WT) mice. Tissue analysis by immunohistochemistry, enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and zymography was performed.ResultsThrombus resolution was less at 8 days in MMP2 -/- compared with WT, evidenced by a 51% increase in VT size (P < .01), and threefold fewer von Willebrand's factor positive channels (P < .05). In MMP2 -/- mice, the main phenotypic fibrotic differences occurred at 8 days post-VT, with significantly less vein wall collagen content (P = .013), fourfold lower procollagen III gene expression (P < .01), but no difference in procollagen I compared with WT. Decreased inflammation in MMP2 -/- vein walls was suggested by ∼ threefold reduced TNFα and IL-1β at 2 days and 8 days post-VT (P < .05). A fourfold increase in vein wall monocytes (P = .03) with threefold decreased apoptosis (P < .05), but no difference in cellular proliferation at 8 days was found in MMP2 -/- compared with WT. As increased compensatory MMP9 activity was observed in the MMP2 -/-mice, MMP2/9 double null mice had thrombus induced with VT harvest at 8 days. Consistently, twofold larger VT, a threefold decrease in vein wall collagen, and a threefold increase in monocytes were found (all P < .05). Similar findings were observed in MMP9 -/- mice administered an exogenous MMP2 inhibitor.ConclusionsIn stasis VT, deletion of MMP2 was associated with less midterm vein wall fibrosis and inflammation, despite an increase in monocytes. Consideration that VT resolution was impaired with MMP2 (and MMP2/9) deletion suggests direct inhibition will likely also require anticoagulant therapy.Clinical RelevancePost-thrombotic syndrome has no direct therapies and causes significant morbidity. Anticoagulation limits thrombosis but does not clinically impact directly the vein wall response to injury as well as has bleeding risks. In this experimental study, we show that matrix metalloproteinase 2 genetic deletion lessens fibrotic injury and inflammation at the midterm timepoint, yet is also important for thrombus resolution. Future therapies that positively impact vein wall remodeling will need to account for how the thrombus responds as well

    Modelling Eurasian Beaver Foraging Habitat and Dam Suitability, for Predicting the Location and Number of Dams Throughout Catchments in Great Britain

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    Eurasian beaver (Castor fiber) populations are expanding across Europe. Depending on location, beaver dams bring multiple benefits and/or require management. Using nationally available data, we developed: a Beaver Forage Index (BFI), identifying beaver foraging habitat, and a Beaver Dam Capacity (BDC) model, classifying suitability of river reaches for dam construction, to estimate location and number of dams at catchment scales. Models were executed across three catchments, in Great Britain (GB), containing beaver. An area of 6747 km2 was analysed for BFI and 16,739 km of stream for BDC. Field surveys identified 258 km of channel containing beaver activity and 89 dams, providing data to test predictions. Models were evaluated using a categorical binomial Bayesian framework to calculate probability of foraging and dam construction. BFI and BDC models successfully categorised the use of reaches for foraging and damming, with higher scoring reaches being preferred. Highest scoring categories were ca. 31 and 79 times more likely to be used than the lowest for foraging and damming respectively. Zero-inflated negative binomial regression showed that modelled dam capacity was significantly related (p = 0.01) to observed damming and was used to predict numbers of dams that may occur. Estimated densities of dams, averaged across each catchment, ranged from 0.4 to 1.6 dams/km, though local densities may be up to 30 dams/km. These models provide fundamental information describing the distribution of beaver foraging habitat, where dams may be constructed and how many may occur. This supports the development of policy and management concerning the reintroduction and recolonisation of beaver

    Pre-pregnancy predictors of hypertension in pregnancy among Aboriginal and Torres Strait Islander women in north Queensland, Australia; a prospective cohort study

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    BACKGROUND Compared to other Australian women, Indigenous women are frequently at greater risk for hypertensive disorders of pregnancy. We examined pre-pregnancy factors that may predict hypertension in pregnancy in a cohort of Aboriginal and Torres Strait Islander women in north Queensland. METHODS Data on a cohort of 1009 Indigenous women of childbearing age (15–44 years) who participated in a 1998–2000 health screening program in north Queensland were combined with 1998–2008 Queensland hospitalisations data using probabilistic data linkage. Data on the women in the cohort who were hospitalised for birth (n = 220) were further combined with Queensland perinatal data which identified those diagnosed with hypertension in pregnancy. RESULTS Of 220 women who gave birth, 22 had hypertension in the pregnancy after their health check. The mean age of women with and without hypertension was similar (23.7 years and 23.9 years respectively) however Aboriginal women were more affected compared to Torres Strait Islanders. Pre-pregnancy adiposity and elevated blood pressure at the health screening program were predictors of a pregnancy affected by hypertension. After adjusting for age and ethnicity, each 1 cm increase in waist circumference showed a 4% increased risk for hypertension in pregnancy (PR 1.04; 95% CI; 1.02-1.06); each 1 point increase in BMI showed a 9% adjusted increase in risk (1.09; 1.04-1.14). For each 1 mmHg increase in baseline systolic blood pressure there was an age and ethnicity adjusted 6% increase in risk and each 1 mmHg increase in diastolic blood pressure showed a 7% increase in risk (1.06; 1.03-1.09 and 1.07; 1.03-1.11 respectively). Among those free of diabetes at baseline, the presence of the metabolic syndrome (International Diabetes Federation criteria) predicted over a three-fold increase in age-ethnicity-adjusted risk (3.5; 1.50-8.17). CONCLUSIONS Pre-pregnancy adiposity and features of the metabolic syndrome among these young Aboriginal and Torres Strait Islander women track strongly to increased risk of hypertension in pregnancy with associated risks to the health of babies.Sandra K Campbell, John Lynch, Adrian Esterman and Robyn McDermot

    Illinois Waterfowl Surveys and Investigations W-43-R-64 Annual Progress Report FY2017 Period: 1 July 2016 – 30 June 2017

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    Objectives 1) Inventory abundance and distribution of waterfowl, shorebirds, and other waterbirds (a minimum of 10 species and guilds) during autumn migration at a minimum of 30 sites along and nearby the Illinois and central Mississippi rivers, 2) Estimate waterfowl and other waterbird population sizes (a minimum of 10 species and guilds) during autumn migration using an aerial quadrat survey in the central Illinois River Valley for comparison with aerial inventories (Objective 1), 3) Investigate movement and population ecology of lesser scaup, canvasback, and other diving ducks by trapping and leg-banding a minimum of 1,000 individuals during spring migration along the Illinois and Mississippi rivers, 4) Investigate the ecology of American green-winged teal and gadwall by radio-marking a minimum of 40 individuals of each species during spring migration in and nearby the central Illinois River Valley, 5) Investigate movements and home range size of a minimum of 10 Canada geese during winter in and near the Greater Chicago Metropolitan Area (GCMA) of Illinois, 6) Determine habitat quality of a minimum of 50 wetland and deepwater polygons during spring, summer, and early autumn for migrating dabbling ducks, breeding wetland birds, and migrating shorebirds in Illinois, and 7) Distribute results and findings to site managers and biologists of the Illinois Department of Natural Resources (IDNR) and other state agencies, the Mississippi Flyway Technical Section, the Upper Mississippi River and Great Lakes Region (UMRGLR) Joint Venture, the U.S. Fish and Wildlife Service, other scientists and collaborators as requested, and the general public through oral presentations, popular articles, technical reports, and peer reviewed publications; make recommendations for future wetland management practices and research needs based on results and related research; contribute to regional conservation planning efforts during the project period as appropriate and requested.Illinois Department of Natural Resources, Division of Wildlife & U.S. Fish and Wildlife Service Contract Number: RC09-13FWUIUCunpublishednot peer reviewedOpe

    Monitoring a simple hydrolysis process in an organic solid by observing methyl group rotation

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    We report a variety of experiments and calculations and their interpretations regarding methyl group (CH3) rotation in samples of pure 3-methylglutaric anhydride (1), pure 3-methylglutaric acid (2), and samples where the anhydride is slowly absorbing water from the air and converting to the acid [C6H8O3(1) + H2O → C6H10O4(2)]. The techniques are solid state 1H nuclear magnetic resonance (NMR) spin-lattice relaxation, single-crystal X-ray diffraction, electronic structure calculations in both isolated molecules and in clusters of molecules that mimic the crystal structure, field emission scanning electron microscopy, differential scanning calorimetry, and high resolution 1H NMR spectroscopy. The solid state 1H spin-lattice relaxation experiments allow us to observe the temperature dependence of the parameters that characterize methyl group rotation in both compounds and in mixtures of the two compounds. In the mixtures, both types of methyl groups (that is, molecules of 1 and 2) can be observed independently and simultaneously at low temperatures because the solid state 1H spin-lattice relaxation is appropriately described by a double exponential. We have followed the conversion 1 → 2 over periods of two years. The solid state 1H spin-lattice relaxation experiments in pure samples of 1 and 2 indicate that there is a distribution of NMR activation energies for methyl group rotation in 1 but not in 2 and we are able to explain this in terms of the particle sizes seen in the field emission scanning electron microscopy images
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