615 research outputs found

    Cyclic cycle systems of the complete multipartite graph

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    In this paper, we study the existence problem for cyclic ℓ\ell-cycle decompositions of the graph Km[n]K_m[n], the complete multipartite graph with mm parts of size nn, and give necessary and sufficient conditions for their existence in the case that 2ℓ∣(m−1)n2\ell \mid (m-1)n

    Structure and functional motifs of GCR1, the only plant protein with a GPCR fold?

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    Whether GPCRs exist in plants is a fundamental biological question. Interest in deorphanizing new G protein coupled receptors (GPCRs), arises because of their importance in signaling. Within plants, this is controversial as genome analysis has identified 56 putative GPCRs, including GCR1 which is reportedly a remote homologue to class A, B and E GPCRs. Of these, GCR2, is not a GPCR; more recently it has been proposed that none are, not even GCR1. We have addressed this disparity between genome analysis and biological evidence through a structural bioinformatics study, involving fold recognition methods, from which only GCR1 emerges as a strong candidate. To further probe GCR1, we have developed a novel helix alignment method, which has been benchmarked against the the class A – class B - class F GPCR alignments. In addition, we have presented a mutually consistent set of alignments of GCR1 homologues to class A, class B and class F GPCRs, and shown that GCR1 is closer to class A and /or class B GPCRs than class A, class B or class F GPCRs are to each other. To further probe GCR1, we have aligned transmembrane helix 3 of GCR1 to each of the 6 GPCR classes. Variability comparisons provide additional evidence that GCR1 homologues have the GPCR fold. From the alignments and a GCR1 comparative model we have identified motifs that are common to GCR1, class A, B and E GPCRs. We discuss the possibilities that emerge from this controversial evidence that GCR1 has a GPCR fol

    The Seven-sphere and its Kac-Moody Algebra

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    We investigate the seven-sphere as a group-like manifold and its extension to a Kac-Moody-like algebra. Covariance properties and tensorial composition of spinors under S7S^7 are defined. The relation to Malcev algebras is established. The consequences for octonionic projective spaces are examined. Current algebras are formulated and their anomalies are derived, and shown to be unique (even regarding numerical coefficients) up to redefinitions of the currents. Nilpotency of the BRST operator is consistent with one particular expression in the class of (field-dependent) anomalies. A Sugawara construction is given.Comment: 22 pages. Macropackages used: phyzzx, epsf. Three epsf figure files appende

    Barriers and enablers of physical activity engagement for patients with COPD in primary care

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    Maria-Christina Kosteli,1 Nicola R Heneghan,1 Carolyn Roskell,1 Sarah E Williams,1 Peymane Adab,2 Andrew P Dickens,2 Alexandra Enocson,2 David A Fitzmaurice,2 Kate Jolly,2 Rachel Jordan,2 Sheila Greenfield,2 Jennifer Cumming1 1School of Sport, Exercise and Rehabilitation Sciences, 2Institute of Applied Health Research, University of Birmingham, Edgbaston, Birmingham, UK Background: Given that physical activity (PA) has a positive impact on COPD symptoms and prognosis, this study examined the factors that both encourage and limit participation in PA for individuals with COPD in a primary care setting from the perspective of social cognitive theory.Methods: A purposive sample of 26 individuals with a range of COPD severity (age range: 50–89 years; males =15) were recruited from primary care to participate in one of four focus groups. Thematic analysis was undertaken to identify key concepts related to their self-efficacy beliefs.Results: Several barriers and enablers closely related to self-efficacy beliefs and symptom severity were identified. The main barriers were health related (fatigue, mobility problems, breathing issues caused by the weather), psychological (embarrassment, fear, frustration/disappointment), attitudinal (feeling in control of their condition, PA perception, older age perception), and motivational. The main enabling factors were related to motivation (autonomous or controlled), attitudes, self-regulation, and performance accomplishments.Clinical implications: When designing interventions for individuals with COPD, it is important to understand the patient-specific social cognitive influences on PA participation. This information can then inform individually tailored management planning. Keywords: COPD, social cognitive theory, self-efficacy, barriers, enablers, primary car

    Effect of increasing initial implant dosage on feedlot performance and carcass characteristics of long-fed steer and heifer calves1,2

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    Three experiments evaluated initial implant strategies for finishing cattle. In Exp. 1, heifers (n = 1,405; initial BW = 282 kg) were given (1) Revalor-IH followed by Revalor-200 (REV-IH/200), (2) Revalor-H followed by Revalor-200 (REV-H/200), or (3) Revalor-200 followed by Revalor-200 (REV-200/200). Intake, ADG, and G:F were not affected (P ≄ 0.14) by implant strategies, nor were HCW and LM area (P ≄ 0.16). Percent USDA Choice was greater (P \u3c 0.01) for Rev-IH/200 compared with Rev-H/200 and Rev-200/200. Experiment 2 used steers (n = 1,858; initial BW = 250 kg) given (1) Revalor-IS reimplanted with Revalor-200 (Rev-IS/200), (2) Revalor-XS followed by Revalor-IS (Rev-XS/IS), (3) Revalor-XS followed by Revalor-S (Rev-XS/S), or (4) Revalor-XS followed by Revalor-200 (Rev-XS/200). Implanting strategies did not affect (P ≄ 0.32) DMI or G:F. Carcass traits were not different (P ≄ 0.18) among treatments, except steers implanted with Rev-XS/200 had greater (P \u3c 0.01) LM area. In Exp. 3, steers (n = 1,408; initial BW = 305 kg) were given (1) Rev-IS/200, (2) Rev-200/200, or (3) Rev-XS/200. Gain and G:F did not differ (P ≄ 0.36) among the 3 implant strategies, nor did HCW or marbling score (P ≄ 0.15). Steers given Rev-XS/200 had greater (P \u3c 0.01) LM area and decreased (P ≀ 0.05) 12th-rib fat and YG compared with Rev-200/200 and Rev-IS/200. Using Rev-200/200 and Rev-XS/200 increased (P = 0.03) USDA Select compared with Rev-IS/200. Using greater-initial-dose implant strategies may not affect ADG or G:F but appears to increase leanness

    Reporting of social deprivation in musculoskeletal trials: an analysis of 402 randomised controlled trials

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    Background: Social deprivation is broadly defined as the restriction of access an individual has to social or cultural interactions due to poverty, discrimination or other disadvantages. While social deprivation is a widely acknowledged determinant of outcome in musculoskeletal conditions, it remains unclear how this is considered in the conduct and interpretation of musculoskeletal trials.  Aim: To determine the frequently to which measures of social deprivation are reported in trials recruiting people with musculoskeletal diseases.  Materials and Methods: We conducted a Pubmed search of randomised controlled trials published between 01 January 2019 and 01 June 2020. We included full-text papers of trials recruiting people with musculoskeletal diseases, irrespective of intervention type or origin. We extracted data relating to trial characteristics, setting, trial design, funding source and musculoskeletal disease. We extracted data on any reported social deprivation index or measure of social deprivation based on internationally adopted indicators. We analysed data descriptively to summarise the reporting of each social deprivation index and measure of social deprivation within trials.  Results: From 2133 potentially eligible citations, 402 were eligible. Mean age of participants was 51.7 years; 63% were female. Trials most frequently recruited people with spinal pain (24.6%) or osteoarthritis (10.0%). Two trials (0.5%) reported social deprivation indices/scores. When assessed by discrete measures of social deprivation, 164 trials (40.8%) reported one or more social deprivation measures. The most commonly reported measures were morbidity (20.2%), employment status (17.7%) and educational attainment (15.5%). Race (6.7%), ethnicity (6.2%) and annual salary (1.3%) were infrequently reported. One trial (0.3%) presented subgroup results by social deprivation measures.  Discussion and Conclusion: Social deprivation is inconsistently reported in musculoskeletal trials. Trialists should report baseline measures of social deprivation in trial reports and aid generalisability to target population, and to examine whether social deprivation might modify treatment effects of interventions for musculoskeletal conditions

    A restatement of the natural science evidence base concerning grassland management, grazing livestock and soil carbon storage

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    Approximately a third of all annual greenhouse gas emissions globally are directly or indirectly associated with the food system, and over a half of these are linked to livestock production. In temperate oceanic regions, such as the UK, most meat and dairy is produced in extensive systems based on pasture. There is much interest in the extent to which such grassland may be able to sequester and store more carbon to partially or completely mitigate other greenhouse gas emissions in the system. However, answering this question is difficult due to context-specificity and a complex and sometimes inconsistent evidence base. This paper describes a project that set out to summarize the natural science evidence base relevant to grassland management, grazing livestock and soil carbon storage potential in as policy-neutral terms as possible. It is based on expert appraisal of a systematically assembled evidence base, followed by a wide stakeholders engagement. A series of evidence statements (in the appendix of this paper) are listed and categorized according to the nature of the underlying information, and an annotated bibliography is provided in the electronic supplementary material

    Electron-ion recombination of Mg6 + forming Mg5 + and of Mg7 + forming Mg6 + : laboratory measurements and theoretical calculations

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    We have measured electron–ion recombination for C-like Mg6+ forming Mg5+, and for B-like Mg7+ forming Mg6+. These studies were performed using a merged electron–ion beam arrangement at the TSR heavy ion storage ring located in Heidelberg, Germany. Both primary ions have metastable levels with significant lifetimes. Using a simple cascade model we estimate the population fractions in these metastable levels. For the Mg6+ results, we find that the majority of the stored ions are in a metastable level, while for Mg7+ the metastable fraction is insignificant. We present the Mg6+ merged beams recombination rate coefficient for DR via N = 2 → N = 2 core electron excitations (ΔN = 0 DR) and for Mg7+ via 2 → 2 and 2 → 3 core excitations. Taking the estimated metastable populations into account, we compare our results to state-of-the-art multiconfiguration Breit–Pauli theoretical calculations. Significant differences are found at low energies where theory is known to be unreliable. Moreover, for both ions we observe a discrepancy between experiment and theory for ΔN = 0 DR involving capture into high-n Rydberg levels and where the stabilization is primarily due to a radiative transition of the excited core electron. This is consistent with previous DR experiments on M-shell iron ions which were performed at TSR. The large metastable content of the Mg6+ ion beam precludes generating a plasma recombination rate coefficient (PRRC). However, this is not an issue for Mg7+ and we present an experimentally derived Mg7+ PRRC for plasma temperatures from 400 K to 107 K with an estimated uncertainty of less than 27% at a 90% confidence level. We also provide a fit to our experimentally derived PRRC for use in plasma modeling codes

    A restatement of the natural science evidence base concerning grassland management, grazing livestock and soil carbon storage

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    Approximately a third of all annual greenhouse gas emissions globally are directly or indirectly associated with the food system, and over a half of these are linked to livestock production. In temperate oceanic regions, such as the UK, most meat and dairy is produced in extensive systems based on pasture. There is much interest in the extent to which such grassland may be able to sequester and store more carbon to partially or completely mitigate other greenhouse gas emissions in the system. However, answering this question is difficult due to context-specificity and a complex and sometimes inconsistent evidence base. This paper describes a project that set out to summarize the natural science evidence base relevant to grassland management, grazing livestock and soil carbon storage potential in as policy-neutral terms as possible. It is based on expert appraisal of a systematically assembled evidence base, followed by a wide stakeholders engagement. A series of evidence statements (in the appendix of this paper) are listed and categorized according to the nature of the underlying information, and an annotated bibliography is provided in the electronic supplementary material.</p
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