Concept definition study for recovery of tumbling satellites. Volume 1: Executive summary, study results

The first assessment is made of the design requirements and conceptual definition of a front end kit to be transported on the currently defined Orbital Maneuvering Vehicle (OMV) and the Space Transportation System Shuttle Orbiter, to conduct remote, teleoperated recovery of disabled and noncontrollable, tumbling satellites. Previous studies did not quantify the dynamic characteristics of a tumbling satellite, nor did they appear to address the full spectrum of Tumbling Satellite Recovery systems requirements. Both of these aspects are investigated with useful results

Concept definition study for recovery of tumbling satellites. Volume 2: Supporting research and technology report

A number of areas of research and laboratory experiments were identified which could lead to development of a cost efficient remote, disable satellite recovery system. Estimates were planned of disabled satellite motion. A concept is defined as a Tumbling Satellite Recovery kit which includes a modular system, composed of a number of subsystem mechanisms that can be readily integrated into varying combinations. This would enable the user to quickly configure a tailored remote, disabled satellite recovery kit to meet a broad spectrum of potential scenarios. The capability was determined of U.S. Earth based satellite tracking facilities to adequately determine the orientation and motion rates of disabled satellites

Lawn-watering perceptions and behaviors of residential homeowners in three Kansas (USA) cities: implications for water quantity and quality

Urbanization is increasing the land area covered with turfgrasses, which may have implications for water quantity and quality. The largest sector of turfgrass is residential lawns. Our objectives were to survey residential homeowners in three Kansas cities about their perceptions, knowledge, and behaviors when irrigating their lawns; each city has distinctive water quantity and quality issues. Surveys were mailed to 15,500 homeowners in Wichita, 10,000 in Olathe, and 5,000 in Salina; the return rate was 11-13%. Wichita residents watered more frequently than Olathe and Salina, possibly because of greater evaporative demand than Olathe, and cheaper water and less concern about water shortages than Salina; Salina and Wichita have similar evaporative demands but Salina had a recent water crisis. Salina homeowners were most concerned about keeping their water bill from getting too high, probably because of higher water costs than the other cities. Overall, 45-60% indicated it was moderately to very important their lawns looked green all the time, while 65-77% ranked water conservation at the same level of importance. Significantly, 61-63% did not know how much water their lawns required and 71-77% did not know how much water they applied to their lawns when they irrigated. About 7-9% swept or blew clippings or lawn-care products directly into streets or storm drains, which run directly into local streams or reservoirs; 9% in Wichita is ~9,000 homeowners. The homeowner’s lawn irrigation knowledge and habits must be improved to help conserve water and protect water quality

Seed production of barnyardgrass (Echinochloa crus-galli) in response to time of emergence in cotton and rice

The spread of herbicide resistance in barnyardgrass (Echinochloa crus-galli (L.) Beauv.) poses a serious threat to crop production in the southern United States. A thorough knowledge of the biology of barnyardgrass is fundamental for designing effective resistance-management programmes. In the present study, seed production of barnyardgrass in response to time of emergence was investigated in cotton and rice, respectively, in Fayetteville and Rohwer, Arkansas, over a 2-year period (2008–09). Barnyardgrass seed production was greater when seedlings emerged with the crop, but some seed production was observed even if seedlings emerged several weeks after crop emergence. Moreover, barnyardgrass seed production was highly variable across environments. When emerging with the crop (0 weeks after crop emergence (WAE)), barnyardgrass produced c. 35 500 and 16 500 seeds/plant in cotton, and c. 39 000 and 2900 seeds/plant in rice, in 2008 and 2009, respectively. Seed production was observed when seedlings emerged up to 5 WAE (2008) or 7 WAE (2009) in cotton and up to 5 WAE (2008, 2009) in rice; corresponding seed production was c. 2500 and 1500 seeds/plant in cotton, and c. 14 700 and 110 seeds/plant in rice, in 2008 and 2009, respectively. The results suggest that cultural approaches that delay the emergence of barnyardgrass or approaches that make the associated crop more competitive will be useful in integrated management programmes. In the context of herbicide resistance management, it may be valuable to prevent seed return to the seedbank, irrespective of cohorts. The findings are vital for parameterizing herbicide resistance simulation models for barnyardgrass

Terahertz near-field microscopy using the self-mixing effect in a quantum cascade laser

We demonstrate terahertz (THz) apertureless near-field microscopy exploiting the self-mixing effect in a quantum cascade laser (QCL). A THz wave is scattered by a sharp needle positioned above an object and coupled back into the QCL cavity resulting in detection of the THz near-field signal through the self-mixing effect. Using this technique we demonstrate two-dimensional imaging at 2.53 THz with a spatial resolution of 1 μm - the highest image resolution achieved with a THz frequency QCL to date. This method offers an experimentally simple approach to coherent, high-resolution THz imaging

Optimization of DNA Extraction Methods for Sequencing of the NADH Dehydrogenase Subunit 2 (ND2) Gene in Rainbow Trout (\u3cem\u3eOncorhynchus mykiss\u3c/em\u3e)

Morphological, behavioral, and genetic variation due to broad geographic ranges is common in salmonid fishes. This variation can be attributed to the isolation of populations from natural phenomenon or human alteration to habitats, which affect gene flow and genetic drift. These changes may play a role in intraspecific genetic variation, potentially isolating them into separate subspecies or locally adapted populations. Rainbow Trout (Oncorhynchus mykiss) are one of the most widely distributed fish species in western North America but no study has identified the main evolutionary lineages from across its range. Identifying and comparing distinct evolutionary lineages can be achieved by comparing sequence data from mitochondrial genes but requires extraction of archived tissue samples of rainbow trout and amplification of selected genes. In this study, we compare different DNA extraction methods for rainbow trout tissue samples, some of which are more than 25 years old. DNA was extracted from tissue samples following a 5 or 15% Chelex method, or by following Zymo Research extraction kit instructions. Following extractions, polymerase chain reaction (PCR) for the highly conserved NADH dehydrogenase subunit 2 mtDNA gene (ND2) was completed using a BIO RAD thermal cycler and a gel electrophoresis is done to determine whether the ND2 gene was successfully amplified. Photographs of the agarose gels were taken using a ChemiDoc imaging system, and samples showing a band at 1050 base pairs are sent to the Molecular Research Core Facility at Idaho State University for sequencing. The genetic sequences are then compared and used to create a phylogeny and distribution for Rainbow trout subspecies. Sequencing of individual specimen and comparison across the species range will aid in the development of management and conservation strategies for rainbow trout across the species range

Terahertz near-field microscopy using the self-mixing effect in a quantum cascade laser

We demonstrate terahertz (THz) apertureless nearfield microscopy exploiting the self-mixing effect in a quantum cascade laser (QCL). A THz wave is scattered by a sharp needle positioned above an object and coupled back into the QCL cavity resulting in detection of the THz near-field signal through the self-mixing effect. Using this technique we demonstrate twodimensional imaging at 2.53 THz with a spatial resolution of ︎ 1 µm – the highest image resolution achieved with a THz frequency QCL to date. This method offers an experimentally simple approach to coherent, high-resolution THz imaging

A global synthesis of fire effects on pollinators

Understanding fire effects on pollinators is critical in the context of fire regime changes and the global pollination crisis. Through a systematic and quantitative review of the literature, we provide the first global assessment of pollinator responses to fire. We hypothesize that pollinators increase after fire and during the early postfire succession stages; however, high fire frequency has the opposite effect, decreasing pollinators. Location: Terrestrial ecosystems, excluding Antarctica. Time period: Data collected from 1973 to 2017. Major taxa studied: Insects (Coleoptera, Diptera, Hymenoptera and Lepidoptera) and a few bird species. Methods: We first compiled available studies across the globe that assessed fire effects on pollinator communities. Then, by means of hierarchical meta-analyses, we evaluated how different fire regime parameters (fire frequency, postfire time and fire type) and habitat characteristics affect the abundance and richness of animals that act as pollinators. We also explored to what extent the responses vary among taxa groups and life history traits of pollinators (sociality system, nest location and feeding specialization), and among biomes. The overall effect size of fire on pollinator abundance and richness across all studies was positive. Fire effect was especially clear and significant in early postfire communities, after wildfires, and for Hymenoptera. Taxonomic resolution influenced fire effects, where only studies at the species/genus and family levels showed significant effects. The main exceptions were recurrent fires that showed a negative effect, and especially wildfire effects on Lepidoptera abundance that showed a significant negative response. Main conclusions: Pollinators tend to be promoted after a wildfire event. However, short fire intervals may threat pollinators, and especially lepidopterans. Given the current fire regime changes at the global scale, it is imperative to monitor postfire pollinators across many ecosystems, as our results suggest that fire regime is critical in determining the dynamics of pollinator communities.Fil: Carbone, Lucas Manuel. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Tavella, Julia Rita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Pausas, Juli G.. Universidad de Valencia; EspañaFil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Bison Influences on Composition and Diversity of Riparian Plant Communities in Yellowstone National Park

Riparian zones are among the most biologically diverse ecosystems in the Intermountain West, USA, and provide valuable ecosystem services, including high rates of biotic productivity, nutrient processing, and carbon storage. Thus, their sustainability is a high priority for land managers. Large ungulates affect composition and structure of riparian/stream ecosystems through herbivory and physical effects, via trailing and trampling. Bison (Bison bison) in Yellowstone National Park (YNP) have been characterized as ecosystem engineers because of their demonstrated effects on phenology, aboveground productivity of grasses, and woody vegetation structure. Bison have greatly increased in numbers during the last two decades and spend large periods of time in the broad open floodplains of the Northern Range of the Park, where they are hypothesized to have multiple effects on plant species composition and diversity. We sampled indicators of bison use as well as riparian vegetation composition, diversity, and structure along eight headwater streams within YNP\u27s Northern Range. Total fecal density ranged from 333 to 1833 fecal chips and/or piles/ha, stubble heights ranged from 7 to 49 cm, and streambank disturbance ranged from 9% to 62%. High levels of bison use were positively correlated with exotic species dominance and negatively correlated with species richness, native species diversity, willow (Salix spp.) cover, and wetland species dominance. At three sites, the intensity of bison use exceeded recommended utilization thresholds to avoid degradation of streams and riparian zones on public lands. The influences of large herbivores, principally bison, on vegetation composition and structure suggest the cumulative effects of the current densities on the Northern Range are contributing to biotic impoverishment, representing the loss of ecosystem services that are provided by native riparian plant communities. In addition, contemporary levels of bison use may be exacerbating climate change effects as observed through ungulate-related shifts in composition toward plant assemblages adapted to warmer and drier conditions. However, the resilience of native riparian vegetation suggests that sites currently heavily utilized by bison would have the potential for recovery with a reduction in pressure by this herbivore