Do stiffness and asymmetries predict change of direction performance?

Change of direction speed (CODS) underpins performance in a wide range of sports but little is known about how stiffness and asymmetries affect CODS. Eighteen healthy males performed unilateral drop jumps to determine vertical, ankle, knee and hip stiffness, and a CODS test to evaluate left and right leg cutting performance during which ground reaction force data were sampled. A step-wise regression analysis was performed to ascertain the determinants of CODS time. A two-variable regression model explained 63% (R-2 = 0.63; P = 0.001) of CODS performance. The model included the mean vertical stiffness and jump height asymmetry determined during the drop jump. Faster athletes (n = 9) exhibited greater vertical stiffness (F = 12.40; P = 0.001) and less asymmetry in drop jump height (F = 6.02; P = 0.026) than slower athletes (n = 9); effect sizes were both "large" in magnitude. Results suggest that overall vertical stiffness and drop jump height asymmetry are the strongest predictors of CODS in a healthy, non-athletic population

Reliability of unilateral vertical leg stiffness measures assessed during bilateral hopping

The assessment of vertical leg stiffness is an important consideration given its relationship to performance. Vertical stiffness is most commonly assessed during a bilateral hopping task. The current study sought to determine the inter-session reliability, quantified by the coefficient of variation, of vertical stiffness during bilateral hopping when assessed for the left and right limbs independently, this had not been previously investigated. On four separate occasions, ten healthy males performed 30 unshod bilateral hops on a dual force plate system with data recorded independently for the left and right limbs. Vertical stiffness was calculated as the ratio of peak ground reaction force to the peak negative displacement of the centre of mass during each hop and was averaged over the 6-10th hops. For vertical stiffness, average coefficients of variation of 15.3% and 14.3% were observed for the left and right limbs respectively. An average coefficient of variation of 14.7% was observed for bilateral vertical stiffness. The current study reports that calculations of unilateral vertical stiffness demonstrate reliability comparable to bilateral calculations. Determining unilateral vertical stiffness values and relative discrepancies may allow the coach to build a more complete stiffness profile of an individual athlete and better inform the training process

A comparison of methods to determine bilateral asymmetries in vertical leg stiffness

Whilst the measurement and quantification of vertical leg stiffness (Kvert) asymmetry is of important practical relevance to athletic performance, literature investigating bilateral asymmetry in Kvert is limited. Moreover, how the type of task used to assess Kvert may affect the expression of asymmetry has not been properly determined. Twelve healthy males performed three types of performance task on a dual force plate system to determine Kvert asymmetries; the tasks were: a) bilateral hopping, b) bilateral drop jumping, and c) unilateral drop jumping. Across all three methods, Kvert was significantly different between compliant and stiff limbs (P < 0.001) with a significant interaction effect between limb and method (P = 0.005). Differences in Kvert between compliant and stiff limbs were -5.3% (P < 0.001), -21.8% (P = 0.007) and -15.1% (P < 0.001) for the bilateral hopping, bilateral drop jumping and unilateral drop jumping methods respectively. All three methods were able to detect significant differences between compliant and stiff limbs, and could be used as a diagnostic tool to assess Kvert asymmetry. Drop jumping tasks detected larger Kvert asymmetries than hopping, suggesting that asymmetries may be expressed to a greater extent in acyclic, maximal performance tasks

Unilateral stiffness interventions augment vertical stiffness and change of direction speed

It has previously been shown that pre-conditioning interventions can augment change of direction speed (CODS). However, the mechanistic nature of these augmentations has not been well considered. The current study sought to determine the effects of pre-conditioning interventions designed to augment vertical stiffness on CODS. Following familiarization, ten healthy males (age: 22 ± 2 years; height: 1.78 ± 0.05 m; body mass: 75.1 ± 8.7 kg) performed three different stiffness interventions in a randomized and counterbalanced order. The interventions were: a) bilateral-focused, b) unilateral-focused, and c) a control of CODS test practice. Vertical stiffness and joint stiffness was determined pre- and post-intervention using a single leg drop jump task. CODS test performance was assessed post-intervention using a double 90o cutting task. Performances following the unilateral intervention were significantly faster than control (1.7%; P = 0.011; d = -1.08), but not significantly faster than the bilateral intervention (1.0% faster; P = 0.14; d = -0.59). Versus control, vertical stiffness was 14% greater (P = 0.049; d = 0.39) following the unilateral intervention and 11% greater (P = 0.019; d = 0.31) following the bilateral intervention; there was no difference between unilateral and bilateral interventions (P = 0.94; d = -0.08). The findings of the current study suggest that unilateral pre-conditioning interventions designed to augment vertical stiffness improve CODS within this experimental cohort

Consensus of the definitions of the OMERACT glucocorticoid impact core domain set for people with rheumatic and musculoskeletal diseases

Background: The Outcome Measures in Rheumatology (OMERACT) Glucocorticoid (GC) Impact Working Grouphas been working to develop a core domain set to measure the impact of GCs on patients living with rheumaticand musculoskeletal diseases. The mandatory domains previously identified for inclusion in all clinical trialsmeasuring the GC effects include infection, bone fragility, mood disturbance, hypertension, diabetes, weight,fatigue, and mortality. Before progressing to instrument selection, the Working Group sought to establish precisedefinitions of all mandatory domains within the core domain set.Methods: OMERACT methodology was applied with the use of evidence and consensus-based decision making ofall stakeholder groups (patient research partners, health care professionals, clinician researchers, industrymembers and methodologists) to develop detailed definitions for the broad domain, target domain and domaincomponents, taking into consideration sources of variability that could affect measurement of the domain. Theworking group synthesized prior qualitative studies, quantitative work, and results from Delphi rounds, todevelop a rich definition of ‘what’ is to be measured.Results: Between 2021 and 2023, the OMERACT Working Group on GC Impact conducted virtual meetings toestablish domain definitions. First, we mapped each domain onto an OMERACT Core Area. All domains wereprimarily represented within the Pathophysiological Manifestations Core Area, except from Fatigue which wasprimarily Life Impact and Weight which spanned both Core Areas. Sources of variability included cultural factors, age, gender, education level, socioeconomic status, personal experiences, emotional state, and languagebarriers. The domain definitions will form the foundation for instrument selection and the initial step of domain /concept match and content validity in the OMERACT pillar of ‘truth’ before moving on to feasibility anddiscrimination.Conclusion: The OMERACT GC Impact Working Group has developed and agreed upon detailed domain definitions for core domains. Future steps of the working group are to select instruments and develop the core outcom

The Spectral Energy Distributions of Red 2MASS AGN

We present infrared (IR) to X-ray spectral energy distributions (SEDs) for 44 red AGN selected from the 2MASS survey on the basis of their red J-K$_S$ color (>2 mag) and later observed by Chandra. In comparison with optically-, radio-, and X-ray selected AGN, their median SEDs are red in the optical and near-IR with little/no blue bump. It thus seems that near-IR color selection isolates the reddest subset of AGN that can be classified optically. The shape of the SEDs is generally consistent with modest absorption by gas (in the X-ray) and dust (in the optical-IR). The levels of obscuration, estimated from X-rays, far-IR and our detailed optical/near-IR color modeling are all consistent implying N_H < few*10^{22} cm^{-2}. We present SED models that show how the AGN optical/near-IR colors change due to differing amounts of reddening, AGN to host galaxy ratio, redshift and scattered light emission and apply them to the sources in the sample. We find that the 2MASS AGN optical color, B-R, and to a lesser extent the near-IR color, J-K$_S$, are strongly affected by reddening, host galaxy emission, redshift, and in few, highly polarized objects, also by scattered AGN light. The obscuration/inclination of the AGN allows us to see weaker emission components which are generally swamped by the AGN.Comment: 52 pages, 17 figures, accepted for publication in Ap

The OMERACT emerging leaders program: The good, the bad, and the future

The Journal of Rheumatology Copyright © 2019. All rights reserved. Objective. To describe the experience of the first OMERACT Emerging Leaders Program (ELP). Methods. A Delphi process identified positive aspects, areas for improvement, and future directions. Core items were defined as essential if they received ≥ 70% ratings. Results. Participants valued relatable/accessible mentors (100%), including an OMERACT Executive mentor (100%), and a support network of peers (90%). Key items for future development were funding support (100%) and developing knowledge about OMERACT processes (90%) and politics (80%). Conclusion. The ELP has the potential to provide targeted training for early career researchers to develop relevant skills for future leadership roles within OMERACT

Evolutionary inference across eukaryotes identifies universal features shaping organelle gene retention

Mitochondria and plastids power complex life. Why some genes and not others are retained in their organelle DNA (oDNA) genomes remains a debated question. Here, we attempt to identify the properties of genes and associated underlying mechanisms that determine oDNA retention. We harness over 15k oDNA sequences and over 300 whole genome sequences across eukaryotes with tools from structural biology, bioinformatics, machine learning, and Bayesian model selection. Previously hypothesized features, including the hydrophobicity of a protein product, and less well-known features, including binding energy centrality within a protein complex, predict oDNA retention across eukaryotes, with additional influences of nucleic acid and amino acid biochemistry. Notably, the same features predict retention in both organelles, and retention models learned from one organelle type quantitatively predict retention in the other, supporting the universality of these features—which also distinguish gene profiles in more recent, independent endosymbiotic relationships. A record of this paper’s transparent peer review process is included in the supplemental information

The patient perspective of nurse-led care in early rheumatoid arthritis: A systematic review of qualitative studies with thematic analysis

Introduction: Management of rheumatoid arthritis has changed dramatically over the last decade and is characterised by early start of intensive treatment and tight monitoring of disease activity until remission. The role of nurse-led care at early stage of disease is not well understood.Aims: To develop an understanding of rheumatology nurse-led care from the perspective of patients with early rheumatoid arthritis.Methods: A systematic review of qualitative studies, reported in line with PRISMA checklist. In March 2019, the following databases were searched: MEDLINE, EMBASE, CINAHL, PsycINFO and OpenGrey. Studies were included if they: included adults with rheumatoid arthritis; were qualitative studies with data on patients' perspectives of nurse-led care; and published in peer-reviewed journals, in English, between 2010-2019. Due to few studies in early rheumatoid arthritis, inclusion was extended to adults with established rheumatoid arthritis. Two reviewers screened abstracts and full texts. Joanna Briggs Institute Critical Appraisal Tool was used for quality assessment. Thematic synthesis was conducted according to the framework of Thomas and Harden (2008).Results: The search identified 1034 records. After screening and assessing for eligibility, eight qualitative studies were included in the review (133 patients). Three themes were identified from the synthesis. Nurse-led care was seen to provide professional expertise in planning and delivery of care. A person-centred approach was used combined with good communication skills, thus creating a positive therapeutic environment. Nurse-led care was described as providing a sense of empowerment and psychological support.Conclusion: Patients with rheumatoid arthritis are supportive of nurse-led care. They value its professionalism and person-centred approach which provide a sense of security and confidence.Relevance to clinical practice: The findings outline ingredients of nurse-led care that are important to patients. These can inform nurses' professional development plans, service improvement and the competence framework for rheumatology nursing

Differential spatial repositioning of activated genes in Biomphalaria glabrata snails infected with Schistosoma mansoni

Copyright @ 2014 Arican-Goktas et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Schistosomiasis is an infectious disease infecting mammals as the definitive host and fresh water snails as the intermediate host. Understanding the molecular and biochemical relationship between the causative schistosome parasite and its hosts will be key to understanding and ultimately treating and/or eradicating the disease. There is increasing evidence that pathogens that have co-evolved with their hosts can manipulate their hosts' behaviour at various levels to augment an infection. Bacteria, for example, can induce beneficial chromatin remodelling of the host genome. We have previously shown in vitro that Biomphalaria glabrata embryonic cells co-cultured with schistosome miracidia display genes changing their nuclear location and becoming up-regulated. This also happens in vivo in live intact snails, where early exposure to miracidia also elicits non-random repositioning of genes. We reveal differences in the nuclear repositioning between the response of parasite susceptible snails as compared to resistant snails and with normal or live, attenuated parasites. Interestingly, the stress response gene heat shock protein (Hsp) 70 is only repositioned and then up-regulated in susceptible snails with the normal parasite. This movement and change in gene expression seems to be controlled by the parasite. Other differences in the behaviour of genes support the view that some genes are responding to tissue damage, for example the ferritin genes move and are up-regulated whether the snails are either susceptible or resistant and upon exposure to either normal or attenuated parasite. This is the first time host genome reorganisation has been seen in a parasitic host and only the second time for any pathogen. We believe that the parasite elicits a spatio-epigenetic reorganisation of the host genome to induce favourable gene expression for itself and this might represent a fundamental mechanism present in the human host infected with schistosome cercariae as well as in other host-pathogen relationships.NIH and Sandler Borroughs Wellcome Travel Fellowshi