3,232 research outputs found
Chemistry and Apparent Quality of Surface Water and Ground Water Associated with Coal Basins
Personnel of the Arkansas Mining and Mineral Resources Research Institute conducted preliminary investigations on the chemistry and quality of surface and ground water associated with 12 coal-bearing sub-basins in the Arkansas Valley coal field. The coal field is approximately 60 miles long and 33 miles wide but only in 12 areas coal is thick enough and has proper quality to be termed commercial. Both surface and underground sample sites were established in each of the sub-basins with some minor variations in four areas where not all types of sites could be located. Water was collected from 19 surface points and 19 underground points in the established areas. Both field and laboratory analyses were made and elemental contents are reported herein. In the main, the chemistry and water quality suggests that all water is suitable for agricultural and industrial uses. To obtain potable water, treatment must be made to reduce calcium, magnesium, sodium sulfate and iron. The mineral content of the water is due to its contact with coal-bearing zones and, as such, reflects the mineral content of the coal. However, it is recommended that additional studies on the petrography and geochemistry of the coal, overburden and underburden is in order. Also, it is recommended that at least one detailed study be made of one of the coal sub-basins where geologic parameters can be completely established with regard to hydrogeology. This report is an important first step in determining the character and quality of Arkansas coal which must be fully understood to fully utilize this important mineral resource
KINETOCHORES ASSOCIATED WITH THE NUCLEAR ENVELOPE IN THE MITOSIS OF A DINOFLAGELLATE
This is the publisher's version, also available electronically from "http://jcb.rupress.org".No abstract availabl
Habitat zonation on coral reefs: Structural complexity, nutritional resources and herbivorous fish distributions
Distinct zonation of community assemblages among habitats is a ubiquitous feature of coral
reefs. The distribution of roving herbivorous fishes (parrotfishes, surgeonfishes and rabbitfishes) is a particularly clear example, with the abundance of these fishes generally peaking
in shallow-water, high-energy habitats, regardless of the biogeographic realm. Yet, our
understanding of the factors which structure this habitat partitioning, especially with regards
to different facets of structural complexity and nutritional resource availability, is limited. To
address this issue, we used three-dimensional photogrammetry and structure-from-motion
technologies to describe five components of structural complexity (rugosity, coral cover, verticality, refuge density and field-of-view) and nutritional resource availability (grazing surface
area) among habitats and considered how these factors are related to herbivorous fish distributions. All complexity metrics (including coral cover) were highest on the slope and crest.
Nutritional resource availability differed from this general pattern and peaked on the outerflat. Unexpectedly, when compared to the distribution of herbivorous fishes, none of the
complexity metrics had a marked influence in the models. However, grazing surface area
was a strong predictor of both the abundance and biomass of herbivorous fishes. The strong
relationship between grazing surface area and herbivorous fish distributions indicates that
nutritional resource availability may be one of the primary factors driving the distribution of
roving herbivorous fishes. The lack of a relationship between complexity and herbivorous
fishes, and a strong affinity of herbivorous fishes for low-complexity, algal turf-dominated
outer-flat habitats, offers some cautious optimism that herbivory may be sustained on future,
low-complexity, algal turf-dominated reef configurations
Host-Derived Artificial MicroRNA as an Alternative Method to Improve Soybean Resistance to Soybean Cyst Nematode
Citation: Tian, B., Li, J. R., Oakley, T. R., Todd, T. C., & Trick, H. N. (2016). Host-Derived Artificial MicroRNA as an Alternative Method to Improve Soybean Resistance to Soybean Cyst Nematode. Genes, 7(12), 13. doi:10.3390/genes7120122Citation: Tian, B., . . . & Trick, H. (2016). Host-Derived Artificial MicroRNA as an Alternative Method to Improve Soybean Resistance to Soybean Cyst Nematode. Genes, 7(12), 13.
https://doi.org/10.3390/genes7120122The soybean cyst nematode (SCN), Heterodera glycines, is one of the most important pests limiting soybean production worldwide. Novel approaches to managing this pest have focused on gene silencing of target nematode sequences using RNA interference (RNAi). With the discovery of endogenous microRNAs as a mode of gene regulation in plants, artificial microRNA (amiRNA) methods have become an alternative method for gene silencing, with the advantage that they can lead to more specific silencing of target genes than traditional RNAi vectors. To explore the application of amiRNAs for improving soybean resistance to SCN, three nematode genes (designated as J15, J20, and J23) were targeted using amiRNA vectors. The transgenic soybean hairy roots, transformed independently with these three amiRNA vectors, showed significant reductions in SCN population densities in bioassays. Expression of the targeted genes within SCN eggs were downregulated in populations feeding on transgenic hairy roots. Our results provide evidence that host-derived amiRNA methods have great potential to improve soybean resistance to SCN. This approach should also limit undesirable phenotypes associated with off-target effects, which is an important consideration for commercialization of transgenic crops
Phylogenetic distance does not predict competition in green algal communities
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116355/1/ecs214005021.pd
Metabolic flexibility as a major predictor of spatial distribution in microbial communities
A better understand the ecology of microbes and their role in the global ecosystem could be achieved if traditional ecological theories can be applied to microbes. In ecology organisms are defined as specialists or generalists according to the breadth of their niche. Spatial distribution is often used as a proxy measure of niche breadth; generalists have broad niches and a wide spatial distribution and specialists a narrow niche and spatial distribution. Previous studies suggest that microbial distribution patterns are contrary to this idea; a microbial generalist genus (Desulfobulbus) has a limited spatial distribution while a specialist genus (Methanosaeta) has a cosmopolitan distribution. Therefore, we hypothesise that this counter-intuitive distribution within generalist and specialist microbial genera is a common microbial characteristic. Using molecular fingerprinting the distribution of four microbial genera, two generalists, Desulfobulbus and the methanogenic archaea Methanosarcina, and two specialists, Methanosaeta and the sulfate-reducing bacteria Desulfobacter were analysed in sediment samples from along a UK estuary. Detected genotypes of both generalist genera showed a distinct spatial distribution, significantly correlated with geographic distance between sites. Genotypes of both specialist genera showed no significant differential spatial distribution. These data support the hypothesis that the spatial distribution of specialist and generalist microbes does not match that seen with specialist and generalist large organisms. It may be that generalist microbes, while having a wider potential niche, are constrained, possibly by intrageneric competition, to exploit only a small part of that potential niche while specialists, with far fewer constraints to their niche, are more capable of filling their potential niche more effectively, perhaps by avoiding intrageneric competition. We suggest that these counter-intuitive distribution patterns may be a common feature of microbes in general and represent a distinct microbial principle in ecology, which is a real challenge if we are to develop a truly inclusive ecology
Atmospheric pressure plasma hydrophilic modification of a silicone surface
Presented in part at the 1st International Conference on Structural Adhesive Bonding (AB2011), Porto, Portugal, 7-8 July 2011.The aim of this study was the creation of a silicone hydrophilic surface prior to bonding. Modifications in wettability and adhesion properties of silicone were performed with an atmospheric plasma torch (APPT). Surface energy variations of the substrate, both pristine and APPT-treated, were evaluated through contact angle measurements, studying the hydrophobic recovery of the samples up to 24 hours of aging. Compositional and topographical changes induced by APPT and aging were studied by attenuated total multiple reflection mode infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), mechanical profilometry, scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively. Adhesion pull-off tests were performed on silicone-aluminium stud joints using three commercial adhesives, which were SikaflexÂŽ-252, polyurethane-based, LoctiteÂŽ-330, urethane methacrylate ester-based acrylic, and TerostatÂŽ-922, modified silicone. Although experimental data of all the bonding specimens led to an undesired adhesive failure, it was found that APPT-treated samples gave higher adhesive strength than the pristine ones, which was explained by the higher surface energy, thus more wettable material, after APPT. This effect remained stable for just 1 h, when the substrate began its hydrophobic recovery, reaching the original surface energy values after 24 h of aging.Financial support from the Universidad Carlos III de Madrid Foundation and Chemistry and Materials Technological Institute ââĂlvaro Alonso Barbaââ are acknowledged, as well as from the Universidad Pontificia Comillas (ICAI) (Spain)
Story in health and social care
This paper offers a brief consideration of how narrative, in the form of peopleâs own stories, potentially figures in health and social care provision as part of the impulse towards patient-centred care. The rise of the epistemological legitimacy of patientsâ stories is sketched here. The paper draws upon relevant literature and original writing to consider the ways in which stories can mislead as well as illuminate the process of making individual treatment care plans
Academic motherhood and fieldwork: Juggling time, emotions and competing demands
The idea and practice of going âinto the fieldâ to conduct research and gather data is a deeply rooted aspect of Geography as a discipline. For global North Development Geographers, amongst others, this usually entails travelling to, and spending periods of time in, often far-flung parts of the global South. Forging a successful academic career as a Development Geographer in the UK, is therefore to some extent predicated on mobility. This paper aims to critically engage with the gendered aspects of this expected mobility, focusing on the challenges and time constraints that are apparent when conducting overseas fieldwork as a mother, unaccompanied by her children. The paper emphasises the emotion work that is entailed in balancing the competing demands of overseas fieldwork and mothering, and begins to think through the implications of these challenges in terms of the types of knowledge we produce, as well as in relation to gender equality within the academy
Provisionally pregnant: uncertainty and interpretive work in accounts of home pregnancy testing
Upon their availability for purchase in the 1970s, home pregnancy testing devices were hailed as a ârevolutionâ for womenâs reproductive rights. Some authors, however, have described these technologies as further enabling the medicalisation of pregnancy and as contributing to the devaluing of womenâs embodied knowledge. The home pregnancy test is one of many technological devices encountered by women experiencing pregnancy in the United Kingdom today. Existing literature has described how engagement with medical technologies during pregnancy might address uncertainties experienced at this time, providing women with reassurance and alleviating anxieties. Drawing on interviews with women living in Scotland, this article explores accounts of testing for a first pregnancy, and womenâs descriptions of the impacts of home pregnancy testing upon experiences of early gestation. Participants engaged with pregnancy tests in varying ways, with uses shaping and shaped by their experiences of early pregnancy more broadly. Particular technical characteristics of the home pregnancy test led many participants to question their interpretation of a positive result, as well as the accuracy of the test itself. Rather than addressing the unknowns of early gestation by confirming a suspected pregnancy, a positive result could thus exacerbate uncertainty. Through participantsâ accounts, this article shows how uncertainty is lived out by users of mundane techno-medical artefacts and sheds new light on womenâs experiences of the first trimester of pregnancy
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