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Disease surveillance in wildlife populations presents a logistical challenge, yet is critical in gaining a deeper understanding of the presence and impact of wildlife pathogens. Erinaceus coronavirus (EriCoV), a clade C Betacoronavirus, was first described in Western European hedgehogs (Erinaceus europaeus) in Germany. Here, our objective was to determine whether EriCoV is present, and if it is associated with disease, in Great Britain (GB). An EriCoV-specific BRYT-Green® real-time reverse transcription PCR assay was used to test 351 samples of faeces or distal large intestinal tract contents collected from casualty or dead hedgehogs from a wide area across GB. Viral RNA was detected in 10.8% (38) samples; however, the virus was not detected in any of the 61 samples tested from Scotland. The full genome sequence of the British EriCoV strain was determined using next generation sequencing; it shared 94% identity with a German EriCoV sequence. Multivariate statistical models using hedgehog case history data, faecal specimen descriptions and post-mortem examination findings found no significant associations indicative of disease associated with EriCoV in hedgehogs. These findings indicate that the Western European hedgehog is a reservoir host of EriCoV in the absence of apparent disease.
We have been using the technique of pulsed neutron powder diffraction to study several problems in the physics and chemistry of the actinide elements. In these elements one often encounters very complex structures resulting from polymorphic transformations presumably induced by the presence of 5f-electrons. For exampie, at least five distinct structures of plutonium metal are found between room temperature and its melting point of 640°C, and two of the structures are monoclinic! Single crystals are usually not available, and the high resolution which is intrinsic to the time-of-flight powder technique is a powerful tool in the solution of complex structural problems. The relatively low absorption coefficients for neutrons for at least some actinide isotopes is an advantage when surface oxidation is a problem (as in high-temperature experiments) and provides good particle statistics so that high-quality data are available for Rietveld refinement. The low absorption of neutrons by other materials such as vanadium and fused silica enables the use of these materials for the containment of samples in high- and low-temperature environments, and the fixed geometry of the time-of-flight technique simplifies the design of furnaces and cryostats.
We have determined the strain and particle size for several samples of palladium powder by time-of-flight nrutron powder diffraction on two different diffractometers and by x-ray powder diffraction. The results are compared and found to be in fair agreement. The time-of-flight method gives good enough precision to reveal deficiencies in the simple models used for strain and particle size line broadening.
We have developed a technique for determining the atomic elastic constants from measurements of the Debye-Waller factors. The Debye-Waller factors are obtained by Rietveld refinement of time-of-flight neutron diffraction data and interpreted in terms of an atomic Debye-Waller temperature. The method is applicable to powders and to materials that must be encapsulated for safety or environmental reasons. We will illustrate our technique with applications to actinide metals, to metallic hydrides and to high-temperature superconductors.
OBJECTIVES/SPECIFIC AIMS: Our research hypothesis is that resting state fMRI (rsfMRI) data can be used to identify regions of the brain which are associated with cognitive decline in patients – thereby providing a tool by which to characterize AD progression in patients. METHODS/STUDY POPULATION: We used data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to analyze Mini-Mental State Examination (MMSE) questionnaire scores from 14 patients diagnosed with AD at two measurement occasions. RsfMRI data was available at the first of these occasions for these patients. These rsfMRI data were summarized into 264 node-based graph theory measures of clustering coefficient and eigenvector centrality. To address our research hypothesis, we modeled changes in patient MMSE scores over time as a function of these rsfMRI data, controlling for relevant confounding factors. This model accounted for the high-dimensionality of our predictor data, the longitudinal nature of the outcome, and our desire to identify a subset of regions in the brain most associated with the MMSE outcome. RESULTS/ANTICIPATED RESULTS: The use of either the clustering coefficient or eigenvector centrality rsfMRI predictors in modeling MMSE scores for patients over time resulted in the identification of different subsets of brain regions associated with cognitive decline. This suggests that these predictors capture different information on patient propensity for cognitive decline. Further work is warranted to validate these results on a larger sample of ADNI patients. DISCUSSION/SIGNIFICANCE OF IMPACT: We conclude that different rsfMRI graph theory measures capture different aspects of cognitive function and decline in patients, which could be a future consideration in clinical practice.
Changing management in UK lowland pasture systems has lead to larger fertiliser inputs, increased intensity and frequency of cutting and a movement towards silage rather than hay based systems. This has lead to changes in both floral diversity and the seasonal characteristics of sward architectural complexity, which include the loss of key vegetation structures at critical times of the year. e.g., seed heads. This has had large impacts on invertebrate communities in pasture systems and is thought to be the cause of large-scale declines in both the abundances and diversity of invertebrates (Duffey et al., 1974). This decline in invertebrate abundance has also been linked to a concomitant decline in farmland bird populations reliant on invertebrates as a food sources (Vickery et al., 2001). By manipulating cattle grazing, cutting and fertiliser regimes in intensively managed pasture systems the role of vegetation structure for a variety of invertebrate communities has been investigated.
Glaciers often advance over proglacial sediments, which then may enhance basal motion. For glaciers with abundant meltwater, thermodynamic considerations indicate that the sediment–ice contact in the direction of ice flow tends toward an angle opposed to and somewhat steeper than the surface slope (by slightly more than 50%). A simple model based on this hypothesis yields the extent of over-ridden sediments as a function of sediment thickness and strength, a result that may be useful in guiding additional fieldwork for hypothesis testing. Sediment-floored as well as rock-floored overdeepenings are common features along glacier flow paths and are expected based on theories of glacier erosion, entrainment, transport and deposition.
Two rain events at Matanuska Glacier illustrate how subglacial drainage system development and snowpack conditions affect hydrologic response at the terminus. On 21 and 22 September 1995, over 56 mm of rain fell in the basin during a period usually characterized by much drier conditions. This event caused an 8-fold increase in discharge and a 47-fold increase in suspended-sediment concentration. Peak suspended-sediment concentration exceeded 20 kg m —3, suggesting rapid evacuation of stored sediment. While water discharge returned to its pre-storm level nine days after the rain ceased, suspended- sediment concentrations took about 20 days to return to pre-storm levels. These observations suggest that the storm influx late in the melt season probably forced subglacial water into a more distributed system. In addition, subglacially transported sediments were supplemented to an unknown degree by the influx of storm-eroded sediments off hillslopes and from tributary drainage basins.
A storm on 6 and 7 June 1997, dropped 28 mm of rain on the basin demonstrating the effects of meltwater retention in the snowpack and englacial and subglacial storage early in the melt season. Streamflow before the storm event was increasing gradually owing to warming temperatures; however, discharge during the storm and the following week increased only slightly. Suspended-sediment concentrations increased only a small amount, suggesting the drainage system was not yet well developed, and much of the run off occurred across the relatively clean surface of the glacier or through englacial channels.
Several different types of laterally extensive debris bands occur along the western terminus region of the Matanuska Glacier, Alaska, U.S.A. An ice-bed process, which to our knowledge has not previously been recognized and described, forms the most common and most prominent type of debris band at Matanuska Glacier’s terminus. The debris bands are composed of one or several millimeter-thick laminations of silt-rich ice having much higher sediment content than that of the surrounding ice. Samples of these bands and their surrounding englacial ice have been analyzed for anthropogenic tritium (3H), oxygen-18 (δ18O), and deuterium (δD).We interpreted the laminated, silt-rich debris bands as basal fractures, along which silt-laden, glaciohydraulically supercooled and pressurized waters flowed, healing the fractures by ice growth. This process is analogous to the inward growth of hydrothermal quartz from the sides of an open fracture.
The numerous debris bands in the terminus region of Matanuska Glacier, Alaska, U.S.A., were formed by injection of turbid meltwaters into basal crevasses. The debris bands are millimeter(s)-thick layers of silt-rich ice cross-cutting older, debris-poor englacial ice. The sediment grain-size distribution of the debris bands closely resembles the suspended load of basal waters, and of basal and proglacial ice grown from basal waters, but does not resemble supraglacial debris, till or the bedload of subglacial streams. Most debris bands contain anthropogenic tritium (3H) in concentrations similar to those of basal meltwater and ice formed from that meltwater, but cross-cut englacial ice lacking tritium. Stable-isotopic ratios (δ18O and δD) of debris-band ice are consistent with freezing from basal waters, but are distinct from those in englacial ice. Ice petrofabric data along one debris band lack evidence of active shearing. High basal water pressures and locally extensional ice flow associated with overdeepened subglacial basins favor basal crevasse formation.
Simple theory supports field observations (Lawson and others, 1998 that subGlaciol water flow out of overdeepenings can cause accretion of layered, debris-bearing ice to the bases of glaciers. The large meltwater flux into a temperate glacier at the onset of summer melting can cause rapid water flow through expanded basal cavities or other flow paths. If that flow ascends a sufficiently steep slope out of an overdeepèning, the water will supercool as the pressure-melting point rises, and basal-ice accretion will occur. Diurnal, occasional or annual fluctuations in water discharge will cause variations in accretion rate, debris content of accreted ice or subsequent diagenesis, producing layers. Under appropriate conditions, net accretion of debris-bearing basal ice will allow debris fluxes that are significant in the glacier sediment budget.
Debris-laden ice accretes to the base of Matanuska Glacier, Alaska, U.S.A., from water that supercools while flowing in a distributed drainage system tip the adverse slope of an overdeepening. Frazil ice grows in the water column and forms aggregates, while other ice grows on the glacier sole or on substrate materials. Sediment is trapped by this growing ice, forming stratified debris-laden basal ice. Growth rates of >0.l ma−1 of debris-rich basal ice are possible. The large sediment fluxes that this mechanism allows may have implications for interpretation of the widespread deposits from ice that flowed through other overdeepenings, including Heinrich events and the till sheets south of the Laurentian Great Lakes.
The stratified-facies ice of the basal zone of Matanuska Glacier, Alaska. U.S.A., contains significant concentrations of anthropogenic tritium, whereas unaltered englacial-zone ice is devoid of tritium. Supercooled water flowing through subglacial conduits during the melt season likewise contains tritium, as does frazil and other platy ice that nucleates and grows within this subglacially flowing water. These initial results demonstrate net accretion of more than 1.4 m of stratified basal-zone ice since initiation of above-ground, thermonuclear bomb testing in 1952. Furthermore, these results support a theory of basal ice formation by ice accretion and debris entrainment from supercooled water within a distributed subglacial drainage system.
Skin and soft tissue infections (SSTIs) due to Staphylococcus aureus have become increasingly common in the outpatient setting; however, risk factors for differentiating methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) SSTIs are needed to better inform antibiotic treatment decisions. We performed a case-case-control study within 14 primary-care clinics in South Texas from 2007 to 2015. Overall, 325 patients [S. aureus SSTI cases (case group 1, n = 175); MRSA SSTI cases (case group 2, n = 115); MSSA SSTI cases (case group 3, n = 60); uninfected control group (control, n = 150)] were evaluated. Each case group was compared to the control group, and then qualitatively contrasted to identify unique risk factors associated with S. aureus, MRSA, and MSSA SSTIs. Overall, prior SSTIs [adjusted odds ratio (aOR) 7·60, 95% confidence interval (CI) 3·31–17·45], male gender (aOR 1·74, 95% CI 1·06–2·85), and absence of healthcare occupation status (aOR 0·14, 95% CI 0·03–0·68) were independently associated with S. aureus SSTIs. The only unique risk factor for community-associated (CA)-MRSA SSTIs was a high body weight (⩾110 kg) (aOR 2·03, 95% CI 1·01–4·09).
We describe the serendipitous discovery of two new lithium-rich M5 members of the Scorpius-Centaurus OB Association (Sco-Cen). Both stars exhibit large 12 and 22 μm excesses and strong, variable Hα emission which we attribute to accretion from circumstellar discs. Such stars are thought to be incredibly rare at the ~16 Myr median age of much of Sco-Cen. The serendipitous discovery of two accreting stars hosting large quantities of circumstellar material may be indicative of a sizeable age spread in Sco-Cen, or further evidence that disc dispersal and planet formation time-scales are longer around lower-mass stars.
Paterson showed how to construct an étale groupoid from an inverse semigroup using ideas from functional analysis. This construction was later simplified by Lenz. We show that Lenz’s construction can itself be further simplified by using filters: the topological groupoid associated with an inverse semigroup is precisely a groupoid of filters. In addition, idempotent filters are closed inverse subsemigroups and so determine transitive representations by means of partial bijections. This connection between filters and representations by partial bijections is exploited to show how linear representations of inverse semigroups can be constructed from the groups occurring in the associated topological groupoid.