201 research outputs found

    Investigation of A1g phonons in YBa2Cu3O7 by means of LAPW atomic-force calculations

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    We report first-principles frozen-phonon calculations for the determination of the force-free geometry and the dynamical matrix of the five Raman-active A1g modes in YBa2Cu3O7. To establish the shape of the phonon potentials atomic forces are calculated within the LAPW method. Two different schemes - the local density approximation (LDA) and a generalized gradient approximation (GGA) - are employed for the treatment of electronic exchange and correlation effects. We find that in the case of LDA the resulting phonon frequencies show a deviation from experimental values of approximately -10%. Invoking GGA the frequency values are significantly improved and also the eigenvectors are in very good agreement with experimental findings.Comment: 15 page

    Tris{N-[bis­(dimethyl­amino)phosphino­yl]-2,2,2-trichloro­acetamido}(triphenyl­phosphine oxide)holmium(III)

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    In the title compound, [Ho(C6H12Cl3N3O2P)3(C18H15OP)], the HoIII ion is surrounded by six O atoms from the three bidentate N-[bis­(dimethyl­amino)phosphino­yl]-2,2,2-trichloro­acetamido ligands (L −) and by one O atom from the triphenyl­phosphine oxide ligand, with the formation of a distorted monocapped octa­hedron. In one ligand L −, the trichloro­methyl group is rotationally disordered between two orientations in a 1:1 ratio, while two dimethyl­amino groups in another ligand L − are disordered between two conformations, each with the same 1:1 ratio

    Diel turbidity cycles in a headwater stream: evidence of nocturnal bioturbation?

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    Purpose: A small number of recent studies have linked daily cycles in stream turbidity to nocturnal bioturbation by aquatic fauna, principally crayfish, and demonstrated this process can significantly impact upon water quality under baseflow conditions. Adding to this limited body of research, we use high-resolution water quality monitoring data to investigate evidence of diel turbidity cycles in a lowland, headwater stream with a known signal crayfish (Pacifastacus leniusculus) population and explore a range of potential causal mechanisms. Materials and methods: Automatic bankside monitoring stations measured turbidity and other water quality parameters at 30-min resolution at three locations on the River Blackwater, Norfolk, UK during 2013. Specifically, we focused on two 20-day periods of baseflow conditions during January and April 2013 which displayed turbidity trends typical of winter and spring seasons, respectively. The turbidity time-series, which were smoothed with 6.5 hour Savitzky-Golay filters to highlight diel trends, were correlated against temperature, stage, dissolved oxygen and pH to assess the importance of abiotic influences on turbidity. Turbidity was also calibrated against suspended particulate matter (SPM) over a wide range of values via linear regression. Results and discussion: Pronounced diel turbidity cycles were found at two of the three sites under baseflow conditions during April. Spring night-time turbidity values consistently peaked between 21:00 and 04:00 with values increasing by ~10 nephelometric turbidity units (NTU) compared with the lowest recorded daytime values which occurred between 10:00 and 14:00. This translated into statistically significant increases in median midnight SPM concentration of up to 76% compared with midday, with night-time (18:00 – 05:30) SPM loads also up to 30% higher than that recorded during the daytime (06:00 – 17:30). Relating turbidity to other water quality parameters exhibiting diel cycles revealed there to be neither any correlation that might indicate a causal link, nor any obvious mechanistic connections to explain the temporal turbidity trends. Diel turbidity cycles were less prominent at all sites during the winter. Conclusions: Considering the seasonality and timing of elevated turbidity, visual observations of crayfish activity, and an absence of mechanistic connections with other water quality parameters, the results presented here are consistent with the hypothesis that nocturnal bioturbation is responsible for generating diel turbidity cycles under baseflow conditions in headwater streams. However, further research in a variety of fluvial environments is required to better assess the spatial extent, importance and causal mechanisms of this phenomenon

    The Quadrupole Magnets for the LHC Injection Transfer Lines

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    Two injection transfer lines, each about 2.8 km long, are being built to transfer protons at 450 GeV from the Super Proton Synchrotron (SPS) to the Large Hadron Collider (LHC). A total of 180 quadrupole magnets are required; they are produced in the framework of the contribution of the Russian Federation to the construction of the LHC. The classical quadrupoles, built from laminated steel cores and copper coils, have a core length of 1.4 m, an inscribed diameter of 32 mm and a strength of 53.5 T/m at a current of 530 A. The total weight of one magnet is 1.1 ton. For obtaining the required field quality at the small inscribed diameter, great care in the stamping of the laminations and the assembly of quadrants is necessary. Special instruments have been developed to measure, with a precision of some mm, the variations of the pole gaps over the full length of the magnet and correlate them to the obtained field distribution. The design has been developed in a collaboration between BINP and CERN. Fabrication and the magnetic measurements are done at BINP and should be finished at the end of the year 2000

    Solitary fibrous tumour of the genitourinary tract: a clinicopathological study of 11 cases and their association with the NAB2-STAT6 fusion gene

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    Aims To characterise clinicopathological features and clinical outcomes of the genitourinary tract solitary fibrous tumours, incorporating NAB2-STAT6 gene fusion status. Methods The presence of the molecular hallmark NAB2-STAT6 gene fusion and for the defining fusion partner product STAT6 was assessed in 11 cases of the genitourinary tract solitary fibrous tumours. NAB2-STAT6 gene fusion analysis was performed using a break-apart fluorescence in situ hybridisation (FISH) probe using a probe cocktail with Bacterial artificial chromosome (BAC) clones for STAT6 and NAB2. Results Eleven solitary fibrous tumours were diagnosed in eight male patients and three female patients with a mean age of 46 years (range: 11–64 years). Four of the tumours had malignant histological features, and three were considered moderate risk for metastasis. With a mean follow-up time of 61 months, 1 recurred locally and 2 presented at distant metastatic sites. Using a break-apart FISH probe cocktail, we found the NAB2-STAT6 gene fusion and nuclear STAT6 expression in 58% and 91% of cases, respectively. However, the NAB2-STAT6 fusion status was not correlated with STAT6 expression or useful in discriminating between malignant histological features or subsequent clinical outcomes in the genitourinary solitary fibrous tumours. Conclusions A subset of solitary fibrous tumours of the genitourinary tract behaved aggressively. Using a break-apart FISH probe cocktail, we found the NAB2-STAT6 gene fusion in 64% of cases. However, the NAB2-STAT6 fusion status was not correlated with STAT6 expression or useful in discriminating between low-risk or high-risk tumours and subsequent clinical outcomes

    Safety and efficacy of muramidase from Trichoderma reesei DSM 32338 as a feed additive for turkeys for fattening, turkeys reared for breeding, chickens reared for breeding and other poultry species reared for breeding

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of muramidase produced by Trichoderma reesei DSM 32338. The additive is considered safe for turkeys for fattening, turkeys reared for breeding, chickens reared for laying/breeding and other poultry species reared for breeding up to the maximum recommended dose of 45,000 LSU(F)/kg feed. The additive is considered safe for the consumer and the environment. No conclusions can be reached on the potential of the additive for skin/eye irritancy and skin sensitisation. The additive should be considered a potential respiratory sensitiser. The additive has the potential to be efficacious as a zootechnical additive in turkeys for fattening, turkeys reared for breeding, chickens reared for laying/breeding and other poultry species reared for breeding when added to feed at 25,000 LSU(F)/kg feed

    Assessment of the application for renewal of authorisation of Bactocell® (Pediococcus acidilactici CNCM I-4622) as a feed additive for weaned piglets, pigs for fattening, minor porcine species (weaned and for fattening), chickens for fattening, laying hens and minor avian species for fattening and for laying and its extension of use to all growing pigs and all avian species

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on Bactocell\uae (Pediococcus acidilactici CNCM I-4622) in the context of the renewal of the authorisation for weaned piglets, pigs for fattening, minor porcine species (weaned and for fattening), chickens for fattening, laying hens and minor avian species for fattening and for laying when used as a zootechnical feed additive (gut flora stabiliser) in feed or in water for drinking. In addition, the applicant requested the extension of use for suckling piglets, minor pig species (growing/for fattening), chickens reared for laying, chickens reared for breeding purposes, chickens for breeding purposes, turkeys and minor avian species (including non-food producing/ornamental birds) reared for laying/breeding purposes and for breeding purposes when used as in feed or in water for drinking. The applicant has provided evidence that the additive currently on the market complies with the conditions of authorisation. The additive is safe for the target species, consumers and the environment as well. The additive is non-irritant to skin and eyes and is not a dermal sensitiser but should be considered a respiratory sensitiser. Considering the high dusting potential of the formulations, exposure of users by inhalation is very likely. The additive, at the level of 1  7 109 CFU/kg feed (5  7 108 when delivered in water), has the potential to be efficacious in the new species proposed: chickens reared for laying, chickens reared for breeding purposes, chickens for breeding purposes, turkeys and minor avian species reared for laying/breeding purposes and for breeding purposes (including non-food producing/ornamental birds) and in suckling piglets and minor porcine species (growing/for fattening)

    Measurement of CNGS muon neutrino speed with Borexino

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    We have measured the speed of muon neutrinos with the Borexino detector using short-bunch CNGS beams. The final result for the difference in time-of-flight between a =17 GeV muon neutrino and a particle moving at the speed of light in vacuum is {\delta}t = 0.8 \pm 0.7stat \pm 2.9sys ns, well consistent with zero.Comment: 6 pages, 5 figure

    PPP-RTK and inter-system biases: the ISB look-up table as a means to support multi-system PPP-RTK

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    PPP-RTK has the potential of benefiting enormously from the integration of multiple GNSS/RNSS systems. However, since unaccounted inter-system biases (ISBs) have a direct impact on the integer ambiguity resolution performance, the PPP-RTK network and user models need to be flexible enough to accommodate the occurrence of system-specific receiver biases. In this contribution we present such undifferenced, multi-system PPP-RTK full-rank models for both network and users. By an application of (Formula presented.)-system theory, the multi-system estimable parameters are presented, thereby identifying how each of the three PPP-RTK components are affected by the presence of the system-specific biases. As a result different scenarios are described of how these biases can be taken into account. To have users benefit the most, we propose the construction of an ISB look-up table. It allows users to search the table for a network receiver of their own type and select the corresponding ISBs, thus effectively realizing their own ISB-corrected user model. By applying such corrections, the user model is strengthened and the number of integer-estimable user ambiguities is maximized

    Assessment of the application for renewal of authorisation of Biosprint® (Saccharomyces cerevisiae MUCL 39885) for sows

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    Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of authorisation of the product Biosprint\uae (Saccharomyces cerevisiae MUCL 39885) as a feed additive for sows. S. cerevisiae is considered by EFSA to have qualified presumption of safety (QPS) status. The applicant has provided data demonstrating that the additive currently in the market complies with the conditions of authorisation. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) Panel confirms that the use of Biosprint\uae under the current authorised conditions of use is safe for sows, the consumers and the environment. The additive is considered as a potential skin and eye irritant and skin/respiratory sensitiser. There is no need to assess the efficacy of Biosprint\uae in the context of the renewal of the authorisation
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