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Understanding the rumen microbial ecosystem requires the identification of factors that influence the community structure, such as nutrition, physiological condition of the host and host–microbiome interactions. The objective of the current study was to describe the rumen microbial communities before, during and after a complete rumen content transfer. The rumen contents of one donor cow were removed completely and used as inoculum for the emptied rumen of the donor itself and three acceptor cows under identical physiological and nutritional conditions. Temporal changes in microbiome composition and rumen function were analysed for each of four cows over a period of 6 weeks. Shortly after transfer, the cows showed different responses to perturbation of their rumen content. Feed intake depression in the first 2 weeks after transfer resulted in short-term changes in milk production, methane emission, fatty acid composition and rumen bacterial community composition. These effects were more pronounced in two cows, whose microbiome composition showed reduced diversity. The fermentation metrics and microbiome diversity of the other two cows were not affected. Their rumen bacterial community initially resembled the composition of the donor but evolved to a new community profile that resembled neither the donor nor their original composition. Descriptive data presented in the current paper show that the rumen bacterial community composition can quickly recover from a reduction in microbiome diversity after a severe perturbation. In contrast to the bacteria, methanogenic communities were more stable over time and unaffected by stress or host effects.
Creep tests provide invaluable data to better understand the physical properties of ice under various conditions. We describe here a simple, updated pneumatic apparatus for experimental studies of ice rheological properties. The apparatus is designed to perform two simultaneous compression creep tests either in a cold room or in atmospheric conditions when coupled to an external cooling circulator. We present results from calibration tests of the apparatus and provide new data from creep tests performed on temperate glacier ice samples. These calibration and creep results show that the apparatus is able to provide fast and reliable mechanical ice characterization. The secondary creep rates measured in this study range between 1.59 × 10−8 s−1 (at 0.21 MPa) and 4.38 × 10−7 s−1 (at 0.71 MPa) at −10°C for quasi-isotropic ice, which is consistent with former standard published data. The corresponding mean parameter, A, is 5.20 × 10−16 s−1 kPa−3, which also compares well with the range of reported other studies.
We show how different aspects of a model of the complex disordered structure of wüstite, Fe1−xO, affect the pair distribution function (PDF) and powder diffraction pattern. The aim is to assess the efficacy of using these techniques to determine details of local structure. The different aspects include the nature of the individual defect clusters, the nature of the paracrystalline superlattice on which they are distributed and the ‘size-effect’ relaxation of the basic rocksalt FeO matrix around the defects. The results show that PDF data are sensitive to those aspects of the models that have a significant effect on the populations of interatomic spacings but are less able to determine correlation structures in the samples if these do not have a substantial interaction with interatomic separations.
Bullying victimization may be linked to psychosis but only self-report measures of victimization have been used so far. This study aimed (a) to investigate the differential associations of peer-nominated versus self-reported victim status with non-clinical psychotic experiences in a sample of young adolescents, and (b) to examine whether different types of self-reported victimization predict non-clinical psychotic experiences in these adolescents.
A combination of standard self-report and peer nomination procedures was used to assess victimization. The sample (n = 724) was divided into four groups (exclusively self-reported victims, self- and peer-reported victims, exclusively peer-reported victims, and non-victims) to test for a group effect on non-clinical psychotic experiences. The relationship between types of victimization and non-clinical psychotic experiences was examined by a regression analysis.
Self-reported victims, along with self- and peer-reported victims, scored higher than peer-reported victims and non-victims on non-clinical psychotic experiences. Self-reports of direct relational, indirect relational and physical victimization significantly improved the prediction of non-clinical psychotic experiences whereas verbal and possession-directed victimization had no significant predictive value.
The relationship between victimization and non-clinical psychotic experiences is only present for self-reported victimization, possibly indicative of an interpretation bias. The observed discrepancy between self-report and peer-report highlights the importance of implementing a combination of both measures for future research.
The objective of this research was to assess current patterns of hospital antibiotic prescribing in Northern Ireland and to determine targets for improving the quality of antibiotic prescribing. A point prevalence survey was conducted in four acute teaching hospitals. The most commonly used antibiotics were combinations of penicillins including β-lactamase inhibitors (33·6%), metronidazole (9·1%), and macrolides (8·1%). The indication for treatment was recorded in 84·3% of the prescribing episodes. A small fraction (3·9%) of the surgical prophylactic antibiotic prescriptions was for >24 h. The results showed that overall 52·4% of the prescribed antibiotics were in compliance with the hospital antibiotic guidelines. The findings identified the following indicators as targets for quality improvement: indication recorded in patient notes, the duration of surgical prophylaxis and compliance with hospital antibiotic guidelines. The results strongly suggest that antibiotic use could be improved by taking steps to address the identified targets for quality improvement.
Influence of processing conditions on electrophysical properties of composite materials (CM) have been investigated. Metal powders, graphite, Z-ferrite and other fillers were used. Properties of CM were investigated in direct and alternating electromagnetic fields.
We present the results of pseudopotential calculations on the InAs/GaAs system with and without interlayers of Ge at the interface. We find that the band alignment depends critically on the positioning of the interlayer at the interface and on the number of monolayers substituted. The results can be explained with recourse to a simple model based on charge transfer between the atoms across the interface.
Electroreflectance (ER) measurements were made on GaAs/AxGal-x As coupled quantum wells at room temperature and at 77K. The close coupling of the narrow (28.3 A) barriers resulted in splitting of the hole and electron subband levels which was observed at both temperatures. As a first approximation, the confining potential was assumed to be due to the barrier alone; electric field effects of the modulating potential and trapped interfacial charge were considered to be negligible. The dominant heavy holeconduction and light hole-conduction transitions observed at 300K were at 1523meV and 1539 meV respectively, although other weaker transitions were also resolved.
In order to investigate the fundamentals of electron migration in nanostructured metal-oxide semiconductors, the transient photocurrent response of dye-sensitized porous nanocrystalline TiO2 is studied. The time-resolved photocurrent response at light steps or pulses shows a faster transient upon increasing the light intensity. Intensity-modulated photocurrent spectroscopy (IMPS) reveals that the transient photocurrent is dominated by two time constants, i.e. the geometrical one and a characteristic time related to electron trapping. A theoretical model is derived in which the occupation dynamics of a single electron trap is considered using Shockley-Read-Hall kinetics. The geometrical RC time of the electrode is also included. Excellent agreement between this model and the measured IMPS spectra is obtained.
Maintaining or improving device performance while scaling semiconductor devices, necessitates the development of extremely shallow (< 20 nm) source/drain extensions with a very high dopant concentration and electrical activation level. Whereas solutions based on RTA with cocktail implants have been proposed in previous generations, sub-45 nm technologies will require even shallower junctions which motivates the research effort on milli-second anneal approaches as these hold the promise of minimal diffusion coupled with high activation levels . Laser annealing is one of these concepts proposed to achieve the junction specifications and is typically described as a msec anneal process. Different from lamp based concepts which illuminate a full wafer simultaneously, the laser has an illuminated area which is much smaller than the wafer size thus necessitating a dedicated scanning pattern. In such a case one is potentially faced with areas subject to multiple overlaps and/or different temperatures and thus issues related to within wafer and within die uniformity need to be addressed.
In this work we use optimized metrology to probe such macro- and micro non-uniformity and determine the origin of the various components contributing to the observed non-uniformity patterns (laser stitching patterns, laser beam uniformity, optical path) and their impact on the local sheet resistance.
The framework of Findlay & Walker's target article provides a first attempt to model the saccadic system at all levels. Their scheme is based on two main principles. These are “parallel processing of saccade timing and metrics” and “competitive inhibition through winner-take-all strategies.” In our opinion, however, both concepts are in their strictest sense at odds with the current knowledge of the saccadic system, and need to be refined to make the scheme more relevant.
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