893 research outputs found

    Effect of Immobilisation on Neuromuscular Function In Vivo in Humans: A Systematic Review

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    This is the final version. Available on open access from Springer Verlag via the DOI in this recordData Availability Statement: Data and materials are available on request from the corresponding author.Background: Muscle strength loss following immobilisation has been predominantly attributed to rapid muscle atrophy. However, this cannot fully explain the magnitude of muscle strength loss, so changes in neuromuscular function (NMF) may be involved. Objectives: We systematically reviewed literature that quantified changes in muscle strength, size and NMF following periods of limb immobilisation in vivo in humans. Methods: Studies were identified following systematic searches, assessed for inclusion, data extracted and quality appraised by two reviewers. Data were tabulated and reported narratively. Results: Forty eligible studies were included, 22 immobilised lower and 18 immobilised upper limbs. Limb immobilisation ranged from 12 h to 56 days. Isometric muscle strength and muscle size declined following immobilisation; however, change magnitude was greater for strength than size. Evoked resting twitch force decreased for lower but increased for upper limbs. Rate of force development either remained unchanged or slowed for lower and typically slowed for upper limbs. Twitch relaxation rate slowed for both lower and upper limbs. Central motor drive typically decreased for both locations, while electromyography amplitude during maximum voluntary contractions decreased for the lower and presented mixed findings for the upper limbs. Trends imply faster rates of NMF loss relative to size earlier in immobilisation periods for all outcomes. Conclusions: Limb immobilisation results in non-uniform loss of isometric muscle strength, size and NMF over time. Different outcomes between upper and lower limbs could be attributed to higher degrees of central neural control of upper limb musculature. Future research should focus on muscle function losses and mechanisms following acute immobilisation. Registration: PROSPERO reference: CRD42016033692

    Correction to: Effect of Immobilisation on Neuromuscular Function In Vivo in Humans: A Systematic Review

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    The following sections 3.5.1 to 3.5.3.2, which previously read

    Effect of Immobilisation on Neuromuscular Function In Vivo in Humans: A Systematic Review

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    BACKGROUND: Muscle strength loss following immobilisation has been predominantly attributed to rapid muscle atrophy. However, this cannot fully explain the magnitude of muscle strength loss, so changes in neuromuscular function (NMF) may be involved. OBJECTIVES: We systematically reviewed literature that quantified changes in muscle strength, size and NMF following periods of limb immobilisation in vivo in humans. METHODS: Studies were identified following systematic searches, assessed for inclusion, data extracted and quality appraised by two reviewers. Data were tabulated and reported narratively. RESULTS: Forty eligible studies were included, 22 immobilised lower and 18 immobilised upper limbs. Limb immobilisation ranged from 12 h to 56 days. Isometric muscle strength and muscle size declined following immobilisation; however, change magnitude was greater for strength than size. Evoked resting twitch force decreased for lower but increased for upper limbs. Rate of force development either remained unchanged or slowed for lower and typically slowed for upper limbs. Twitch relaxation rate slowed for both lower and upper limbs. Central motor drive typically decreased for both locations, while electromyography amplitude during maximum voluntary contractions decreased for the lower and presented mixed findings for the upper limbs. Trends imply faster rates of NMF loss relative to size earlier in immobilisation periods for all outcomes. CONCLUSIONS: Limb immobilisation results in non-uniform loss of isometric muscle strength, size and NMF over time. Different outcomes between upper and lower limbs could be attributed to higher degrees of central neural control of upper limb musculature. Future research should focus on muscle function losses and mechanisms following acute immobilisation. REGISTRATION: PROSPERO reference: CRD42016033692

    Hierarchy Theory of Evolution and the Extended Evolutionary Synthesis: Some Epistemic Bridges, Some Conceptual Rifts

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    Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolution as unfinished or even flawed. In this paper, we analyze and compare two of those conceptual frameworks, namely Niles Eldredge’s Hierarchy Theory of Evolution (with its extended ontology of evolutionary entities) and the Extended Evolutionary Synthesis (with its proposal of an extended ontology of evolutionary processes), in an attempt to map some epistemic bridges (e.g. compatible views of causation; niche construction) and some conceptual rifts (e.g. extra-genetic inheritance; different perspectives on macroevolution; contrasting standpoints held in the “externalism–internalism” debate) that exist between them. This paper seeks to encourage theoretical, philosophical and historiographical discussions about pluralism or the possible unification of contemporary evolutionary biology

    Telephone follow-up of patients after radical prostatectomy : a systematic review

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    Objective: to assess and summarize the best scientific evidence from randomized controlled clinical trials about telephone follow-up of patients after radical prostatectomy, based on information about how the phone calls are made and the clinical and psychological effects for the individuals who received this intervention. Method: the search was undertaken in the electronic databases Medline, Web of Science, Embase, Cinahl, Lilacs and Cochrane. Among the 368 references found, five were selected. Results: two studies tested interventions focused on psychological support and three tested interventions focused on the physical effects of treatment. The psychoeducative intervention to manage the uncertainty about the disease and the treatment revealed statistically significant evidences and reduced the level of uncertainty and anguish it causes. Conclusion: the beneficial effects of telephone follow-up could be determined, as a useful tool for the monitoring of post-prostatectomy patients.Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPq)

    Challenges for Routine Health System Data Management in a Large Public Programme to Prevent Mother-to-Child HIV Transmission in South Africa

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    Background: Recent changes to South Africa's prevention of mother-to-child transmission of HIV (PMTCT) guidelines have raised hope that the national goal of reducing perinatal HIV transmission rates to less than 5% can be attained. While programmatic efforts to reach this target are underway, obtaining complete and accurate data from clinical sites to track progress presents a major challenge. We assessed the completeness and accuracy of routine PMTCT data submitted to the district health information system (DHIS) in three districts of Kwazulu-Natal province, South Africa. Methodology/Principal Findings: We surveyed the completeness and accuracy of data reported for six key PMTCT data elements between January and December 2007 from all 316 clinics and hospitals in three districts. Through visits to randomly selected sites, we reconstructed reports for the same six PMTCT data elements from clinic registers and assessed accuracy of the monthly reports previously submitted to the DHIS. Data elements were reported only 50.3% of the time and were “accurate” (i.e. within 10% of reconstructed values) 12.8% of the time. The data element “Antenatal Clients Tested for HIV” was the most accurate data element (i.e. consistent with the reconstructed value) 19.8% of the time, while “HIV PCR testing of baby born to HIV positive mother” was the least accurate with only 5.3% of clinics meeting the definition of accuracy. Conclusions/Significance: Data collected and reported in the public health system across three large, high HIV-prevalence Districts was neither complete nor accurate enough to track process performance or outcomes for PMTCT care. Systematic data evaluation can determine the magnitude of the data reporting failure and guide site-specific improvements in data management. Solutions are currently being developed and tested to improve data quality

    Quantitative imaging of concentrated suspensions under flow

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    We review recent advances in imaging the flow of concentrated suspensions, focussing on the use of confocal microscopy to obtain time-resolved information on the single-particle level in these systems. After motivating the need for quantitative (confocal) imaging in suspension rheology, we briefly describe the particles, sample environments, microscopy tools and analysis algorithms needed to perform this kind of experiments. The second part of the review focusses on microscopic aspects of the flow of concentrated model hard-sphere-like suspensions, and the relation to non-linear rheological phenomena such as yielding, shear localization, wall slip and shear-induced ordering. Both Brownian and non-Brownian systems will be described. We show how quantitative imaging can improve our understanding of the connection between microscopic dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of methodology. Submitted for special volume 'High Solid Dispersions' ed. M. Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009); 22 pages, 16 fig

    Impacts of organic and conventional crop management on diversity and activity of free-living nitrogen fixing bacteria and total bacteria are subsidiary to temporal effects

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    A three year field study (2007-2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted at the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. The result demonstrated that there was no consistent effect of either organic or conventional soil management across the three years on the diversity or quantity of either diazotrophic or total bacterial communities. However, ordination analyses carried out on data from each individual year showed that factors associated with the different fertility management measures including availability of nitrogen species, organic carbon and pH, did exert significant effects on the structure of both diazotrophic and total bacterial communities. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. The diazotrophic community showed no significant change in diversity across the three years, however, the total bacterial community significantly increased in diversity year on year. Diversity was always greatest during March for both diazotrophic and total bacterial communities. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. Seasonal effects were less consistent in this quantitative study

    Guillain-Barré syndrome: a century of progress

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    In 1916, Guillain, Barré and Strohl reported on two cases of acute flaccid paralysis with high cerebrospinal fluid protein levels and normal cell counts — novel findings that identified the disease we now know as Guillain–Barré syndrome (GBS). 100 years on, we have made great progress with the clinical and pathological characterization of GBS. Early clinicopathological and animal studies indicated that GBS was an immune-mediated demyelinating disorder, and that severe GBS could result in secondary axonal injury; the current treatments of plasma exchange and intravenous immunoglobulin, which were developed in the 1980s, are based on this premise. Subsequent work has, however, shown that primary axonal injury can be the underlying disease. The association of Campylobacter jejuni strains has led to confirmation that anti-ganglioside antibodies are pathogenic and that axonal GBS involves an antibody and complement-mediated disruption of nodes of Ranvier, neuromuscular junctions and other neuronal and glial membranes. Now, ongoing clinical trials of the complement inhibitor eculizumab are the first targeted immunotherapy in GBS
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