896 research outputs found
Kinetics of substrate oxidation and hydrogen peroxide production by Mycoplasma mycoides subsp. mycoides Large Colony (LC) type and Mycoplasma mycoides subsp. capri
Mycoplasma mycoides subsp. mycoides Large Colony (LC) type is a pathogen of goats causing contagious agalactia and respiratory disease, found on all continents where small ruminants are kept. It shares close genetic characteristics with M. mycoides subsp. capri. Substrate oxidation by 22 strains of M. mycoides subsp. mycoides LC from nine countries was compared with that of eight strains of M. mycoides subsp. capri from five countries. There was considerable similarity in the substrates used, but substrate saturation coefficients (Ks) varied for different substrates. Substrate utilization patterns and Ks values did not (1) significantly differentiate the LC strains from each other, (2) show any correlation with geographical origin, or (3) distinguish the LC strains from the capri strains. These results support previous studies justifying the reclassification of these subspecies as a single species
Further evidence to justify reassignment of Mycoplasma mycoides subspecies mycoides Large Colony type to Mycoplasma mycoides subspecies capri
Analysis, using the polymerase chain reaction (PCR), restriction enzyme endonuclease analysis (REA), protein profile patterns, random amplification of polymorphic DNA (RAPD) fingerprinting, 16S rRNA gene sequencing and antisera growth inhibition tests, of 22 strains of Mycoplasma mycoides subsp. mycoides Large Colony type (MmmLC) and eight strains of M. mycoides subsp. capri (Mmc) are presented, along with a summary of comparative data from the literature for over 100 strains, all of which supports the reclassification of the MmmLC and Mmc strains into the single subspecies, M. mycoides subspecies capri
From Research Evidence to “Evidence by Proxy”? Organizational Enactment of Evidence-Based Health Care in Four High-Income Countries
Public Administration Review published by Wiley Periodicals, Inc. on behalf of The American Society for Public Administration. Drawing on multiple qualitative case studies of evidence-based health care conducted in Sweden, Canada, Australia, and the United Kingdom, the authors systematically explore the composition, circulation, and role of codified knowledge deployed in the organizational enactment of evidence-based practice. The article describes the “chain of codified knowledge,” which reflects the institutionalization of evidence-based practice as organizational business as usual, and shows that it is dominated by performance standards, policies and procedures, and locally collected (improvement and audit) data. These interconnected forms of “evidence by proxy,” which are informed by research partly or indirectly, enable simplification, selective reinforcement, and contextualization of scientific knowledge. The analysis reveals the dual effects of this codification dynamic on evidence-based practice and highlights the influence of macro-level ideological, historical, and technological factors on the composition and circulation of codified knowledge in the organizational enactment of evidence-based health care in different countries
Mobilising evidence to improve nursing practice: A qualitative study of leadership roles and processes in four countries
© 2018 Elsevier Ltd Background: The approach and style of leaders is known to be an important factor influencing the translation of research evidence into nursing practice. However, questions remain as to what types of roles are most effective and the specific mechanisms through which influence is achieved. Objectives: The aim of the study was to enhance understanding of the mechanisms by which key nursing roles lead the implementation of evidence-based practice across different care settings and countries and the contextual factors that influence them. Design: The study employed a qualitative descriptive approach. Settings: Data collection was undertaken in acute care and primary/community health care settings in Australia, Canada, England and Sweden. Participants: 55 individuals representing different levels of the nursing leadership structure (executive to frontline), roles (managers and facilitators), sectors (acute and primary/community) and countries. Methods: Individual semi-structured interviews were conducted with all participants exploring their roles and experiences of leading evidence-based practice. Data were analysed through a process of qualitative content analysis. Results: Different countries had varying structural arrangements and roles to support evidence-based nursing practice. At a cross-country level, three main themes were identified relating to different mechanisms for enacting evidence-based practice, contextual influences at a policy, organisational and service delivery level and challenges of leading evidence-based practice. Conclusions: National policies around quality and performance shape priorities for evidence-based practice, which in turn influences the roles and mechanisms for implementation that are given prominence. There is a need to maintain a balance between the mechanisms of managing and monitoring performance and facilitating critical questioning and reflection in and on practice. This requires a careful blending of managerial and facilitative leadership. The findings have implications for theory, practice, education and research relating to implementation and evidence-based practice
Lost in translation: a focus group study of parents’ and adolescents’ interpretations of underage drinking and parental supply
Is there a special mechanism behind the changes in somatic cell and polymorphonuclear leukocyte counts, and composition of milk after a single prolonged milking interval in cows?
<p>Abstract</p> <p>Background</p> <p>A single prolonged milking interval (PMI) e.g. after a technical stop in an automated milking system is of concern for the producer since it is associated with a short-lasting increase in milk somatic cell count (SCC), which is a major quality criterion used at the dairy plants. The content of polymorphonuclear leukocytes (PMN) and how the milk quality is influenced has not been much investigated. The SCC peak occurs without any obvious antigen challenge, possibly indicating a different leukocyte attraction mechanism after a PMI than we see during mastitis.</p> <p>Methods</p> <p>Composite cow milk samples were taken at the milkings twice daily during 7 days before and 5 days after a PMI of 24 h. Milk was analyzed for SCC, PMN, fat, protein and lactose, and at some occasions also casein and free fatty acids (FFA).</p> <p>Results</p> <p>During the PMI the proportion of milk PMN increased sharply in spite of marginally increased SCC. The peak SCC was not observed until the second milking after the PMI, in the afternoon day 1. However, the peak SCC value in <it>morning </it>milk did not occur until one day later, concomitantly with a <it>decrease </it>in the proportion of PMN. After declining, SCC still remained elevated while PMN proportion was decreased throughout the study as was also the milk yield, after the first accumulation of milk during the PMI. Milk composition was changed the day after the PMI, (increased fat and protein content; decreased lactose, whey protein and FFA content) but the changes in the following days were not consistent except for lactose that remained decreased the rest of the study.</p> <p>Conclusion</p> <p>The PMI resulted in increased SCC and proportion of PMN. Additionally, it gave rise to minor alterations in the milk composition in the following milkings but no adverse effect on milk quality was observed. The recruitment of PMN, which was further enhanced the first day <it>after </it>the PMI, appeared to be independent of milk volume or accumulation of milk per se. Hence, we suggest that there is a special immunophysiological/chemoattractant background to the increased migration of leukocytes into the milk compartment observed during and after the PMI.</p
Magnetic resonance imaging (MRI) contrast agents for tumor diagnosis
10.1260/2040-2295.4.1.23Journal of Healthcare Engineering4123-4
The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach
(14)C-Labelled octulose phosphates were formed during photosynthetic (14)CO(2) fixation and were measured in spinach leaves and chloroplasts. Because mono- and bisphosphates of d-glycero-d-ido-octulose are the active 8-carbon ketosugar intermediates of the L-type pentose pathway, it was proposed that they may also be reactants in a modified Calvin–Benson–Bassham pathway reaction scheme. This investigation therefore initially focussed only on the ido-epimer of the octulose phosphates even though (14)C-labelled d-glycero-d-altro-octulose mono- and bisphosphates were also identified in chloroplasts and leaves. (14)CO(2) predominantly labelled positions 5 and 6 of d-glycero-d-ido-octulose 1,8-P(2) consistent with labelling predictions of the modified scheme. The kinetics of (14)CO(2) incorporation into ido-octulose was similar to its incorporation into some traditional intermediates of the path of carbon, while subsequent exposure to (12)CO(2) rapidly displaced the (14)C isotope label from octulose with the same kinetics of label loss as some of the confirmed Calvin pathway intermediates. This is consistent with octulose phosphates having the role of cyclic intermediates rather than synthesized storage products. (Storage products don’t rapidly exchange isotopically labelled carbons with unlabelled CO(2).) A spinach chloroplast extract, designated stromal enzyme preparation (SEP), catalysed and was used to measure rates of CO(2) assimilation with Calvin cycle intermediates and octulose and arabinose phosphates. Only pentose (but not arabinose) phosphates and sedoheptulose 7-phosphate supported CO(2) fixation at rates in excess of 120 μmol h(−1) mg(−1) Chl. Rates for octulose, sedoheptulose and fructose bisphosphates, octulose, hexose and triose monophosphates were all notably less than the above rate and arabinose 5-phosphate was inactive. Altro-octulose phosphates were more active than phosphate esters of the ido-epimer. The modified scheme proposed a specific phosphotransferase and SEP unequivocally catalysed reversible phosphate transfer between sedoheptulose bisphosphate and d-glycero-d-ido-octulose 8-phosphate. It was also initially hypothesized that arabinose 5-phosphate, an L-Type pentose pathway reactant, may have a role in a modified Calvin pathway. Arabinose 5-phosphate is present in spinach chloroplasts and leaves. Radiochromatography showed that (14)C-arabinose 5-phosphate with SEP, but only in the presence of an excess of unlabelled ribose 5-phosphate, lightly labelled ribulose 5-phosphate and more heavily labelled hexose and sedoheptulose mono- and bisphosphates. However, failure to demonstrate any CO(2) fixation by arabinose 5-phosphate as sole substrate suggested that the above labelling may have no metabolic significance. Despite this arabinose and ribose 5-phosphates are shown to exhibit active roles as enzyme co-factors in transaldolase and aldolase exchange reactions that catalyse the epimeric interconversions of the phosphate esters of ido- and altro-octulose. Arabinose 5-phosphate is presented as playing this role in a New Reaction Scheme for the path of carbon, where it is concluded that slow reacting ido-octulose 1,8 bisphosphate has no role. The more reactive altro-octulose phosphates, which are independent of the need for phosphotransferase processing, are presented as intermediates in the new scheme. Moreover, using the estimates of phosphotransferase activity with altro-octulose monophosphate as substrate allowed calculation of the contributions of the new scheme, that ranged from 11% based on the intact chloroplast carboxylation rate to 80% using the carboxylation rate required for the support of octulose phosphate synthesis and its role in the phosphotransferase reaction
Widespread white matter microstructural differences in schizophrenia across 4322 individuals:Results from the ENIGMA Schizophrenia DTI Working Group
The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.Molecular Psychiatry advance online publication, 17 October 2017; doi:10.1038/mp.2017.170
Measurement of exclusive pion pair production in proton–proton collisions at √s=7 TeV with the ATLAS detector
The exclusive production of pion pairs in the process pp→ ppπ+π- has been measured at s=7TeV with the ATLAS detector at the LHC, using 80μb-1 of low-luminosity data. The pion pairs were detected in the ATLAS central detector while outgoing protons were measured in the forward ATLAS ALFA detector system. This represents the first use of proton tagging to measure an exclusive hadronic final state at the LHC. A cross-section measurement is performed in two kinematic regions defined by the proton momenta, the pion rapidities and transverse momenta, and the pion–pion invariant mass. Cross-section values of 4.8±1.0(stat)-0.2+0.3(syst)μb and 9±6(stat)-2+2(syst)μb are obtained in the two regions; they are compared with theoretical models and provide a demonstration of the feasibility of measurements of this type
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