9,413 research outputs found
New crystal packing arrangements in radical cation salts of BEDT-TTF with [Cr(NCS)6]3â and [Cr(NCS)5(NH3)]2â
BEDT-TTF forms three packing arrangement styles in its radical cation salts with [Cr(NCS)6]3â in two of which two trans-oriented isothiocyanate ligands penetrate the BEDT-TTF layers either at the point where a solvent (nitrobenzene) is incorporated in a stack of donors or by four donor molecules forming a âtubeâ motif to accept a ligand at each end along with a small solvent molecule in between (acetonitrile). The [Cr(NCS)5NH3]2â ion forms a related crystal packing arrangement with BEDT-TTF with a reduction in the number of âtubeâ motifs needed to accept an isothiocyanate ligand
Milk whey protein concentration and mRNA associated with ÎČ-lactoglobulin phenotype
Two common genetic variants of ÎČ-lactoglobulin (ÎČ-lg), A and B, exist as co- dominant alleles in dairy cattle (Aschaffenburg, 1968). Numerous studies have shown that cows homozygous for ÎČ-lg A have more ÎČ-lg and less α-lactalbumin (α-la) and casein in their milk than cows expressing only the B variant of ÎČ-lg (Ng-Kwai-Hang et al. 1987; Graml et al. 1989; Hill, 1993; Hill et al. 1995, 1997). These differences have a significant impact on the processing characteristics of the milk. For instance, the moisture-adjusted yield of Cheddar cheese is up to 10% higher using milk from cows of the ÎČ-lg BB phenotype compared with milk from cows expressing only the A variant (Hill et al. 1997). All these studies, however, describe compositional differences associated with ÎČ-lg phenotype in established lactation only. No information is available on the first few weeks of lactation, when there are marked changes in the concentrations of ÎČ-lg and α-la (PĂ©rez et al. 1990)
Targeted interventions for patellofemoral pain syndrome (TIPPS): classification of clinical subgroups
Introduction Patellofemoral pain (PFP) can cause significant pain leading to limitations in societal participation and physical activity. An international expert group has highlighted the need for a classification system to allow targeted intervention for patients with PFP; we have developed a work programme systematically investigating this. We have proposed six potential subgroups: hip abductor weakness, quadriceps weakness, patellar hypermobility, patellar hypomobility, pronated foot posture and lower limb biarticular muscle tightness. We could not uncover any evidence of the relative frequency with which patients with PFP fell into these subgroups or whether these subgroups were mutually exclusive. The aim of this study is to provide information on the clinical utility of our classification system.
Methods and analysis 150 participants will be recruited over 18â
months in four National Health Services (NHS) physiotherapy departments in England. Inclusion criteria: adults 18â40â
years with PFP for longer than 3â
months, PFP in at least two predesignated functional activities and PFP elicited by clinical examination. Exclusion criteria: prior or forthcoming lower limb surgery; comorbid illness or health condition; and lower limb training or pregnancy. We will record medical history, demographic details, pain, quality of life, psychomotor movement awareness and knee temperature. We will assess hip abductor and quadriceps weakness, patellar hypermobility and hypomobility, foot posture and lower limb biarticular muscle tightness.
The primary analytic approach will be descriptive. We shall present numbers and percentages of participants who meet the criteria for membership of (1) each of the subgroups, (2) none of the subgroups and (3) multiple subgroups. Exact (binomial) 95% CIs for these percentages will also be presented.
Ethics and dissemination This study has been approved by National Research Ethics Service (NRES) Committee North WestâGreater Manchester North (11/NW/0814) and University of Central Lancashire (UCLan) Built, Sport, Health (BuSH) Ethics Committee (BuSH 025). An abstract has been accepted for the third International Patellofemoral Pain Research Retreat, Vancouver, September 2013
Inflationary Cosmological Perturbations of Quantum-Mechanical Origin
This review article aims at presenting the theory of inflation. We first
describe the background spacetime behavior during the slow-roll phase and
analyze how inflation ends and the Universe reheats. Then, we present the
theory of cosmological perturbations with special emphasis on their behavior
during inflation. In particular, we discuss the quantum-mechanical nature of
the fluctuations and show how the uncertainty principle fixes the amplitude of
the perturbations. In a next step, we calculate the inflationary power spectra
in the slow-roll approximation and compare these theoretical predictions to the
recent high accuracy measurements of the Cosmic Microwave Background radiation
(CMBR) anisotropy. We show how these data already constrain the underlying
inflationary high energy physics. Finally, we conclude with some speculations
about the trans-Planckian problem, arguing that this issue could allow us to
open a window on physical phenomena which have never been probed so far.Comment: Review Article, 47 pages, 3 figures. Lectures given at the 40th
Karpacz Winter School on Theoretical Physics (Poland, Feb. 2004), submitted
to Lecture Notes in Physic
How personality and dispositional empathy predict contact quality: The mediating roles of contact self-efficacy and effort towards contact
An extragalactic supernebula confined by gravity
Little is known about the origins of the giant star clusters known as
globular clusters. How can hundreds of thousands of stars form simultaneously
in a volume only a few light years across the distance of the sun to its
nearest neighbor? Radiation pressure and winds from luminous young stars should
disperse the star-forming gas and disrupt the formation of the cluster.
Globular clusters in our Galaxy cannot provide answers; they are billions of
years old. Here we report the measurement of infrared hydrogen recombination
lines from a young, forming super star cluster in the dwarf galaxy, NGC 5253.
The lines arise in gas heated by a cluster of an estimated million stars, so
young that it is still enshrouded in gas and dust, hidden from optical view. We
verify that the cluster contains 4000-6000 massive, hot "O" stars. Our
discovery that the gases within the cluster are bound by gravity may explain
why these windy and luminous O stars have not yet blown away the gases to allow
the cluster to emerge from its birth cocoon. Young clusters in "starbursting"
galaxies in the local and distant universe may be similarly gravitationally
confined and cloaked from view.Comment: Letter to Natur
Automated service monitoring in the deployment of ARCHER2
The ARCHER2 service, a CPU based HPE Cray EX system with 750,080 cores (5,860 nodes), has been deployed throughout 2020 and 2021, going into full service in December of 2021. A key part of the work during this deployment was the integration of ARCHER2 into our local monitoring systems. As ARCHER2 was one of the very first large-scale EX deployments, this involved close collaboration and development work with the HPE team through a global pandemic situation where collaboration and co-working was significantly more challenging than usual. The deployment included the creation of automated checks and visual representations of system status which needed to be made available to external parties for diagnosis and interpretation. We will describe how these checks have been deployed and how data gathered played a key role in the deployment of ARCHER2, the commissioning of the plant infrastructure, the conduct of HPL runs for submission to the Top500 and contractual monitoring of the availability of the ARCHER2 service during its commissioning and early life
Pressure dependence of the Shubnikov-de Haas oscillation pectrum of beta''-(BEDT-TTF)4(NH4)[Cr(C2O4)3].DMF
The Shubnikov-de Haas (SdH) oscillation spectra of the
beta''-(BEDT-TTF)4(NH4)[Cr(C2O4)\_3].DMF organic metal have been studied in
pulsed magnetic fields of up to either 36 T at ambient pressure or 50 T under
hydrostatic pressures of up to 1 GPa. The ambient pressure SdH oscillation
spectra can be accounted for by up to six fundamental frequencies which points
to a rather complex Fermi surface (FS). A noticeable pressure-induced
modification of the FS topology is evidenced since the number of frequencies
observed in the spectra progressively decreases as the pressure increases.
Above 0.8 GPa, only three compensated orbits are observed, as it is the case
for several other isostructural salts of the same family at ambient pressure.
Contrary to other organic metals, of which the FS can be regarded as a network
of orbits, no frequency combinations are observed for the studied salt, likely
due to high magnetic breakdown gap values or (and) high disorder level
evidenced by Dingle temperatures as large as about 7 K.Comment: To be published in European Physical Journal
Expression of Cellulosome Components and Type IV Pili within the Extracellular Proteome of Ruminococcus flavefaciens 007
Funding: The Rowett Institute receives funding from SG-RESAS (Scottish Government Rural and Environmental Science and Analysis Service). Visit of M.V. was supported by research grants from FEMS and Slovene human resources development and scholarship funds. Parts of this work were funded by grants from the United States-Israel Binational Science Foundation (BSF), Jerusalem, Israel â BSF Energy Research grant to E.A.B. and B.A.W. and Regular BSF Research grants to R.L. and B.A.W. â and by the Israel Science Foundation (grant nos 966/09 and 159/07 291/08). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
The cosmic gravitational wave background in a cyclic universe
Inflation predicts a primordial gravitational wave spectrum that is slightly
``red,'' i.e., nearly scale-invariant with slowly increasing power at longer
wavelengths. In this paper, we compute both the amplitude and spectral form of
the primordial tensor spectrum predicted by cyclic/ekpyrotic models. The
spectrum is blue and exponentially suppressed compared to inflation on long
wavelengths. The strongest observational constraint emerges from the
requirement that the energy density in gravitational waves should not exceed
around 10 per cent of the energy density at the time of nucleosynthesis.Comment: 4 pages, 3 figuer
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