699 research outputs found

    Characterization of surficial units on Mars using Viking orbiter multispectral image and thermal data

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    Albedo and thermal property correlations of the topography of Mars were conducted with emphases upon the types and origins of materials exposed in the central equatorial region. This area displays a wide variation in color, albedo and thermal properties, and is relatively free of dust and haze. The physical, mineralogical and elemental characteristics of this area are discussed

    A Collaborative, Trilateral Approach to Bridging the Information Literacy Gap in Student Writing

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    As localized assessments confirm national findings that undergraduates struggle to integrate resources into research-based compositions effectively, data at one comprehensive public university indicate library sessions improve studentsā€™ ability to locate and evaluate information, but students continue to struggle with the ā€œuseā€ component of information literacy. This article presents a trilateral case study among librarians, faculty, and writing center administrators, emphasizing the intersection of programmatic partnerships, assessment, and pedagogical best practices. Our research shows a trilateral approach to information literacy increases efficacy and a sense of shared responsibility in support of student research where traditional bilateral approaches fall short

    Deep space 2: The Mars Microprobe Mission

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    The Mars Microprobe Mission will be the second of the New Millennium Program's technology development missions to planetary bodies. The mission consists of two penetrators that weigh 2.4 kg each and are being carried as a piggyback payload on the Mars Polar Lander cruise ring. The spacecraft arrive at Mars on December 3, 1999. The two identical penetrators will impact the surface at similar to 190 m/s and penetrate up to 0.6 m. They will land within 1 to 10 km of each other and similar to 50 km from the Polar Lander on the south polar layered terrain. The primary objective of the mission is to demonstrate technologies that will enable future science missions and, in particular, network science missions. A secondary goal is to acquire science data. A subsurface evolved water experiment and a thermal conductivity experiment will estimate the water content and thermal properties of the regolith. The atmospheric density, pressure, and temperature will be derived using descent deceleration data. Impact accelerometer data will be used to determine the depth of penetration, the hardness of the regolith, and the presence or absence of 1.0 cm scale layers

    Evaluating student attitudes and learning at remote collegiate soil judging events

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    As with many aspects of teaching, the COVID-19 pandemic forced soil judging teams to attempt new strategies towards achieving student learning outcomes. Soil judging Regions IV and V hosted remote regional contests in October 2020 in place of traditional, in-person contests typically held each fall. We conducted pre- and post-contest surveys to assess student learning outcomes, attitudes, and reflections on the remote contest experience compared to past, in-person contest experiences. We received 108 total responses from students who participated in the Region IV and Region V remote soil judging contests (>80% response rate). In self-reported learning outcomes, there were no significant gains post-contest and there were minimal differences between students in Regions IV and V. Female students, students with more soil judging experience, and students who had taken more soil science courses agreed more strongly that soil science is important, that they planned to pursue careers in soil science, and that they gained important skills from soil judging. Finally, students who previously participated in contests reported that they gained more knowledge and enjoyed in-person contests more than the remote contests held in Fall 2020. Thus, while it is possible to replicate some aspects of the soil judging experience in a remote contest, other aspects that are critical to student engagement are lost when teams are unable to gather at the contest location and examine soils in the field.This article is published as Owen, Rachel K., Amber Anderson, Ammar Bhandari, Kerry Clark, Morgan Davis, Ashlee Dere, Nic Jelinski et al. "Evaluating student attitudes and learning at remote collegiate soil judging events." Natural Sciences Education 50, no. 2 (2021): e20065. doi:10.1002/nse2.20065. Posted with permission.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made

    Algebraic varieties in Birkhoff strata of the Grassmannian Gr(2)\mathrm{^{(2)}}: Harrison cohomology and integrable systems

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    Local properties of families of algebraic subsets WgW_g in Birkhoff strata Ī£2g\Sigma_{2g} of Gr(2)^{(2)} containing hyperelliptic curves of genus gg are studied. It is shown that the tangent spaces TgT_g for WgW_g are isomorphic to linear spaces of 2-coboundaries. Particular subsets in WgW_g are described by the intergrable dispersionless coupled KdV systems of hydrodynamical type defining a special class of 2-cocycles and 2-coboundaries in TgT_g. It is demonstrated that the blows-ups of such 2-cocycles and 2-coboundaries and gradient catastrophes for associated integrable systems are interrelated.Comment: 28 pages, no figures. Generally improved version, in particular the Discussion section. Added references. Corrected typo

    Reliability of Unilateral Isometric and Dynamic Leg Press Force and Power

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    Strength and power are critical components of athletic performance. Athletes commonly perform sport-specific movements off a single leg, but there are few reliable, easily administered unilateral leg force and power assessments. PURPOSE: To determine 1) the reliability of unilateral leg press maximal isometric force (MIF) and peak power tests and 2) the percentage of MIF that elicits unilateral peak power during a dynamic throw. We hypothesized that the tests would be reliable for the assessment of unilateral MIF and peak power and that unilateral peak power would be achieved at 50% of MIF. METHODS: Eighteen apparently healthy, recreationally active adults (17M: 1F; 27.4 Ā± 5.0 years; 1.78 Ā± 0.01 m; 93.5 Ā± 22.5 kg; 3159 Ā± 807 N bilateral MIF) completed three testing sessions. After a brief standardized warm-up, each subject performed three maximal unilateral isometric leg presses (MIF) with each leg at 90Ā° of knee flexion on a modified leg press sled equipped with a force plate, linear encoder, and magnetic brake. Subsequently, the sled was unlocked and loaded in ascending fashion with 30%, 40%, 50%, 60%, and 70% of MIF; with an initial knee angle of 90Ā°, subjects used maximal effort to throw each load twice, unilaterally, with each leg. Subjects rested and reset for 10-30 s between efforts. Data were sampled at 300 Hz, low pass filtered at 4 Hz, and peak instantaneous power (W) was calculated for each throw using the measured sled force and velocity. Intraclass correlation coefficients (ICC) were computed for the highest force and power repetition at each load across the three sessions. The ICC (95% CI) and peak power output were determined for both right and left legs. ICCs were considered excellent if ā‰„ 0.95, high if ā‰„ 0.90, good if ā‰„ 0.80, fair if ā‰„ 0.70, poor if ā‰¤ 0.70, and very poor if ā‰¤ 0.40. RESULTS: MIF showed good reliability between sessions [ICC: 0.85 (0.62, 0.94; left leg); 0.86 (0.58, 0.95; right leg)]. Unilateral peak power also showed good to high reliability between sessions across all loads: ICC (left leg) 30%: 0.91 (0.81, 0.96); 40%: 0.91 (0.81, 0.96); 50%: 0.95 (0.88, 0.98); 60%: 0.93 (0.86, 0.97); 70%: 0.81 (0.64, 0.92); (right leg) 30%: 0.95 (0.89, 0.98); 40%: 0.94 (0.87, 0.97); 50%: 0.92 (0.84, 0.97); 60%: 0.92 (0.84, 0.97); 70%: 0.90 (0.80, 0.96). Across all three sessions, peak power by the left leg was achieved at: 30% (11 of 18 participants); 40% (6 of 18); 50% (1 of 18). Peak power by the right leg was achieved at: 30% (13 of 18 participants); 40% (4 of 18); 50% (1 of 18). CONCLUSION: Unilateral leg press MIF and peak power can be reliably assessed with a modified leg press equipped with a force plate, linear encoder, and magnetic brake in a recreationally active population. Sport teams and coaches can use single leg isometric presses and throws as reliable methods to test their athletesā€™ unilateral force and peak power, respectively, with loads of 30-50% MIF appropriate for peak power measurement

    Biomass and Productivity of Thalassia testudinum in Estuaries of the Florida Panhandle

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    Thalassia testudinum often dominates seagrass meadows of the Florida panhandle but few measurements of productivity, biomass, density, turnover or leaf area index in this region have been made. We targeted 5 estuaries located at similar latitudes, 30ā° Ā± 0.3ā°N: Big Lagoon, Santa Rosa Sound, St. Andrew Bay, St. Joseph Bay, and St. George Sound. This study was one component of a collaborative partnership of state and local researchers examining factors preventing recovery in panhandle estuarine areas that had historically contained seagrass in the 1940s and 1950s. Measurements were made twice in 2016, once in June and then again in summer or fall, except in Santa Rosa Sound where measurements were made 3 times. In the estuaries sampled for the second time in July or August, aboveground productivity was greater than in June. St. Joseph Bay had the highest aboveground productivity (4.3 g/m2/d) and 1ā€”sided leaf area index (4.2) while St. George Sound had the lowest values (0.41 g/m2/d and 1.0). Principal component analysis suggested that St. Andrew Bay, Big Lagoon and Santa Rosa Sound were the most similar, with higher values for shoot densities and leaf turnover and lower salinities and watershed:water ratios. St. Joseph Bay had high aboveground productivity and salinity, and low turbidity. St. George Sound had low aboveground productivity, high total suspended solids and the highest watershed:water ratio. These baseline productivity estimates will be useful to assess the success of restoration efforts targeting seagrasses in the Florida panhandle and evaluate impacts of climate change on seagrasses

    The secretion inhibitor Exo2 perturbs trafficking of Shiga toxin between endosomes and the trans-Golgi network

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    The small-molecule inhibitor Exo2 {4-hydroxy-3-methoxy-(5,6,7,8-tetrahydrol[1]benzothieno[2,3-d]pyrimidin-4-yl)hydraz-one benzaldehyde} has been reported to disrupt the Golgi apparatus completely and to stimulate Golgiā€“ER (endoplasmic reticulum) fusion in mammalian cells, akin to the well-characterized fungal toxin BFA (brefeldin A). It has also been reported that Exo2 does not affect the integrity of the TGN (trans-Golgi network), or the direct retrograde trafficking of the glycolipid-binding cholera toxin from the TGN to the ER lumen. We have examined the effects of BFA and Exo2, and found that both compounds are indistinguishable in their inhibition of anterograde transport and that both reagents significantly disrupt the morphology of the TGN in HeLa and in BS-C-1 cells. However, Exo2, unlike BFA, does not induce tubulation and merging of the TGN and endosomal compartments. Furthermore, and in contrast with its effects on cholera toxin, Exo2 significantly perturbs the delivery of Shiga toxin to the ER. Together, these results suggest that the likely target(s) of Exo2 operate at the level of the TGN, the Golgi and a subset of early endosomes, and thus Exo2 provides a more selective tool than BFA for examining membrane trafficking in mammalian cells

    Estimates of Insulin Sensitivity Using Glucose and C-Peptide From the Hyperglycemia and Adverse Pregnancy Outcome Glucose Tolerance Test

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    OBJECTIVE - To determine if glucose and C-peptide values obtained as part of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study could be used to estimate insulin sensitivity during late pregnancy
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