3,815 research outputs found
Mechanisms of interpersonal sway synchrony and stability
Here we explain the neural and mechanical mechanisms responsible for synchronizing sway and improving postural control during physical contact with another standing person. Postural control processes were modelled using an inverted pendulum under continuous feedback control. Interpersonal interactions were simulated either by coupling the sensory feedback loops or by physically coupling the pendulums with a damped spring. These simulations precisely recreated the timing and magnitude of sway interactions observed empirically. Effects of firmly grasping another person's shoulder were explained entirely by the mechanical linkage. This contrasted with light touch and/or visual contact, which were explained by a sensory weighting phenomenon; each person's estimate of upright was based on a weighted combination of veridical sensory feedback combined with a small contribution from their partner. Under these circumstances, the model predicted reductions in sway even without the need to distinguish between self and partner motion. Our findings explain the seemingly paradoxical observation that touching a swaying person can improve postural control.This work was supported by two BBSRC grants (BB/100579X/1 and an Industry Interchange Award)
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Proposal for Defining a Tall Timber Building
In order to talk about ‘tall’ buildings and more particularly ‘tall, timber’ buildings, it is useful to clarify what is meant by a ‘tall’ and a ‘tall, timber’ building. This clarification facilitates both productive discussion of the subject and secures the basis on which meaningful comparisons can be made between buildings using different structural systems and materials. The historic duopoly of steel and concrete as the structural materials of tall building construction is in the process of being broken by the introduction of engineered timber and it is appropriate that this change is reflected in the language of tall building design. The approach adopted in this paper has three parts. Existing definitions and terminology for ‘tall’ buildings are explored. A study is made of the structural systems and materials of existing buildings that use structural timber and have some claim to ‘tallness’. A proposal is made for the clarification and expansion of existing criteria for tall building terminology and definitions to accommodate the use of structural timber in tall building.This is the author accepted manuscript. The final version is available from the American Society of Civil Engineers via http://dx.doi.org/10.1061/(ASCE)ST.1943-541X.000161
Reproductive dysfunction and associated pathology in women undergoing military training
Evidence from civilian athletes raises the question of whether reproductive dysfunction may be seen in female soldiers as a result of military training. Such reproductive dysfunction consists of impaired ovulation with or without long term subfertility. We critically review pertinent evidence, which points towards reduced energy availability as the most likely explanation for exercise-induced reproductive dysfunction. Evidence also suggests reproductive dysfunction is mediated by activation of the hypothalamic-pituitary-adrenal axis and suppression of the hypothalamic-pituitary-gonadal axis, with elevated ghrelin and reduced leptin likely to play an important role. The observed reproductive dysfunction exists as part of a female athletic triad, together with osteopenia and disordered eating. If this phenomenon was shown to exist with UK military training this would be of significant concern. We hypothesise that the nature of military training and possibly field exercises may contribute to greater risk of reproductive dysfunction among female military trainees compared with exercising civilian controls. We discuss the features of military training and its participants, such as energy availability, age at recruitment, body phenotype, type of physical training, psychogenic stressors, altered sleep pattern and elemental exposure as contributors to reproductive dysfunction. We identify lines of future research to more fully characterise reproductive dysfunction in military women, and suggest possible interventions which, if indicated, could improve their future wellbeing
Observational study of the effects of age, diabetes mellitus, cirrhosis and chronic kidney disease on sublingual microvascular flow.
BACKGROUND: Sidestream dark field (SDF) imaging has been used to demonstrate microcirculatory abnormalities in a variety of critical illnesses. The microcirculation is also affected by advancing age and chronic comorbidities. However, the effect of these conditions on SDF microcirculatory parameters has not been well described. METHODS: SDF images were obtained from five groups of 20 participants: healthy volunteers under the age of 25, healthy volunteers over the age of 55, and clinic patients over the age of 55 with one of diabetes mellitus, cirrhosis and stage 5 chronic kidney disease. Microcirculatory parameters between the groups were then compared for significance using analysis of variance for parametric and the Kruskal-Wallis test for non-parametric data. RESULTS: Median microvascular flow index was 2.85 (interquartile range 2.75 to 3.0) for participants aged 55, 2.88 (2.75 to 3.0) for those with diabetes mellitus, 3.0 (2.83 to 3.0) for those with cirrhosis and 3.0 (2.78 to 3.0) for those with chronic kidney disease (P for difference between groups = 0.14). Similarly, there were no significant differences in the proportion of perfused vessels and perfused vessel density between the groups. CONCLUSIONS: Older age, diabetes, and chronic kidney and liver disease need not be considered confounding factors for comparison of SDF microcirculatory parameters in the critically ill
What is tall timber? Towards the formal classification of timber as a material of tall building design
The emergence of taller buildings using engineered timber as a structural material raises important questions about the language that is used to describe tall buildings. In the absence of formal definitions it is difficult to make meaningful comparisons between buildings using different materials, structural systems and building forms. Claims to the title of 'tallest timber building' are frequently made and may be subject to dispute. This paper discusses the role of the CTBUH Criteria for Defining and Measuring Tall Buildings in the classification of tall buildings and the challenges to the existing criteria raised by the emergence of engineered timber as a contemporary structural material. The paper highlights the authors' proposal for updating the existing terminology to accommodate the use of timber in the design of tall buildings and details the progress that has been made in moving towards a revision of the CTBUH Criteria to include timber. This progress is significant as it represents a critical step forward in bringing timber engineering into the mainstream discourse of tall building construction and places timber on a level playing field with steel and concrete.Leverhulme Trust, EPSR
Risk of heat illness in men and women: a systematic review and meta-analysis
Background Heat illness (HI) is a growing global concern; its incidence has risen dramatically across the world in recent years. The individual factors whereby elevated core temperature produces HI are not well-understood. Given known physiological differences between men and women pertaining to temperature regulation, we hypothesized that women would be at increased risk of HI than men. Objectives We aimed to determine the relative risk of HI in women compared with men through an exhaustive literature review and meta-analysis. Methods We search PubMed and Ovid Medline databases from inception to Apr 2017. Search terms included all permutations of sex and heat illness (including heatstroke and exertional heat illness) with no language restrictions. We included adult or adolescent human data reporting comparable male and female HI rates. One reviewer identified and screened titles and abstracts. Two independent reviewers applied eligibility criteria. Disagreements were resolved with a third reviewer. Results Of 5888 articles identified by searches, 36 were included in the systematic review and 22 in the meta-analysis. The mean (standard deviation) quality score was 3.31(1.25)/5. Overall the rate among women was consistently lower than men across the lifespan. The male: female pooled IRR was 2.28 (p<0.001, 95% CI: 1.66-3.16). There was modest heterogeneity (between-studies variance (Ï„2) = 0.02). The rates did not differ significantly when corrected for severity or occupation. Discussion The rate of HI was significantly increased in men compared with women. Risk for HI might be conferred by psychological and behavioral factors rather than physiological ones. Further research is required to delineate which groups are at greatest risk, leading to the development of mitigation strategies against HI
An evaluation of the benefits and harms of antenatal corticosteroid treatment for women at risk of imminent preterm birth or prior to elective Caesarean-section: an individual participant data meta-analysis.:Study protocol
Background: Antenatal corticosteroid treatment (ACT) has been widely accepted as a safe, beneficial treatment which improves outcomes following preterm birth. It has been shown to reduce respiratory distress syndrome and neonatal mortality and is commonly used in threatened or planned preterm delivery, as well as prior to elective Caesarean-section at term. There are some concerns however, that in some cases, ACT is used in patients where clinical benefit has not been established, or may potentially increase harm. Many women who receive ACT do not deliver preterm and the long-term consequences of ACT treatment are unclear. This study aims to evaluate the benefits and harms of ACT using latest trial evidence to allow refinement of current practice. Methods: This study will compare ACT with placebo or non-treatment. Inclusion criteria are: Randomised Controlled Trials (RCT) comparing ACT vs. no ACT (with or without placebo) in all settings. Exclusion criteria are: non-randomised or quasi-randomised studies and studies comparing single vs. multiple courses of ACT. Main outcomes are to evaluate, for women at risk of preterm birth or undergoing planned Caesarean- section, the benefits and harms of ACT, on maternal, fetal, newborn, and long-term offspring health outcomes. The individual participant data (IPD) of identified RCTs will be collected and consecutively synthesised using meta-analysis with both a one-stage model where all IPD is analysed together and a two-stage model where treatment effect estimates are calculated for each trial individually first and thereafter pooled in a meta-analysis. Sub-group analysis will be performed to identify heterogeneous effects of ACT across predefined risk groups. Discussion: Co-opt is the Consortium for the Study of Pregnancy Treatments and aims to complete a robust evaluation of the benefits and harms of ACT. This IPD meta-analysis will contribute to this by allowing detailed interrogation of existing trial datasets. PROSPERO registration: CRD42020167312 (03/02/2020
How to increase the potential policy impact of environmental science research
This article highlights eight common issues that limit the policy impact of environmental science research. The article also discusses what environmental scientists can do to resolve these issues, including (1) optimising the directness of their study so that it examines similar processes/populations/environments/ecosystems to that of policy interest; (2) using the most powerful study design possible, to increase confidence in the identified causal mechanisms; (3) selecting a sufficient sample size, to reduce the chance of false positives/negatives and increase policy-makers’ confidence in extrapolation of the findings; (4) minimizing the risk of bias through randomization of study units to treatment and control groups (reducing the risk of selection bias), blinding of study units and investigators (reducing the risk of performance and detection bias), following-up study units from enrolment to study completion (reducing the risk of attrition bias) and prospectively registering the study on a publically-available platform (reducing the risk of reporting and publication bias); (5) proving that statistical analyses meet test assumptions by reporting the results of statistical assumption checks, ideally publishing full datasets online in an open-access format; (6) publishing the research whether statistically significant or not, policy-makers are just as interested in the negative or insignificant results as they are in the positive results; (7) making the study easy to find and use, the title and abstract of an article are of high importance in determining whether articles are examined in detail or not and used to inform policy; (8) contributing towards systematic reviews on environmental topics, to provide policy-makers with comprehensive, reproducible and updateable syntheses of all the evidence on a given topic.</p
A new purple sulfur bacterium from saline littoral sediments, Thiorhodotvibrio winogradskyi gen. nov. and sp. nov.
Two strains of a new purple sulfur bacterium were isolated in pure culture from the littoral sediment of a saline lake (Mahoney Lake, Canada) and a marine microbial mat from the North Sea island of Mellum, respectively. Single cells were vibrioid-to spirilloid-shaped and motile by means of single polar flagella. Intracellular photosynthetic membranes were of the vesicular type. As photosynthetic pigments, bacteriochlorophyll a and the carotenoids lycopene, rhodopin, anhydrorhodovibrin, rhodovibrin and spirilloxanthin were present.
Hydrogen sulfide and elemental sulfur were used under anoxic conditions for phototrophic growth. In addition one strain (06511) used thiosulfate. Carbon dioxide, acetate and pyruvate were utilized by both strains as carbon sources. Depending on the strain propionate, succinate, fumarate, malate, tartrate, malonate, glycerol or peptone may additionally serve as carbon sources in the light. Optimum growth rates were obtained at pH 7.2, 33 °C, 50 mol m-2 s-1 intensity of daylight fluorescent tubes and a salinity of 2.2–3.2% NaCl. During growth on sulfide, up to ten small sulfur globules were formed inside the cells. The strains grew microaerophilic in the dark and exhibited high specific respiration rates. No vitamins were required for growth. The DNA base composition was 61.0–62.4 mol% G+C.
The newly isolated bacterium belongs to the family chromatiaceae and is described as a member of a new genus and species, Thiorhodovibrio winogradskyi gen. nov. and sp. nov. with the type strain SSP1, DSM No. 6702
Arthroscopic Treatment of Acetabular Retroversion With Acetabuloplasty and Subspine Decompression: A Matched Comparison With Patients Undergoing Arthroscopic Treatment for Focal Pincer-Type Femoroacetabular Impingement.
BackgroundGlobal acetabular retroversion is classically treated with open reverse periacetabular osteotomy. Given the low morbidity and recent success associated with the arthroscopic treatment of femoroacetabular impingement (FAI), there may also be a role for arthroscopic treatment of acetabular retroversion. However, the safety and outcomes after hip arthroscopic surgery for retroversion need further study, and the effect of impingement from the anterior inferior iliac spine (subspine) in patients with retroversion is currently unknown.HypothesisArthroscopic treatment for global acetabular retroversion will be safe, and patients will have similar outcomes compared with a matched group undergoing arthroscopic treatment for focal pincer-type FAI.Study designCohort study; Level of evidence, 2.MethodsPatients undergoing hip arthroscopic surgery for symptomatic global acetabular retroversion were prospectively enrolled and compared with a matched group of patients undergoing arthroscopic surgery for focal pincer-type FAI. Both groups underwent the same arthroscopic treatment protocol. All patients were administered patient-reported outcome (PRO) measures, including the 12-item Short-Form Health Survey (SF-12) Physical Component Summary (PCS) and a Mental Component Summary (MCS), modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (HOOS), and visual analog scale (VAS) for pain preoperatively and at 1 year postoperatively.ResultsThere were no differences in age, sex, or body mass index between 39 hips treated for global acetabular retroversion and 39 hips treated for focal pincer-type FAI. There were no major or minor complications in either group. Patients who underwent arthroscopic treatment for global acetabular retroversion demonstrated similar significant improvements in postoperative PRO scores (scores increased by 17 to 43 points) as patients who underwent arthroscopic treatment for focal pincer-type FAI. Patients treated for retroversion who also underwent subspine decompression had greater improvement than patients who did not undergo subspine decompression for the HOOS-Pain (33.7 ± 15.3 vs 22.5 ± 17.6, respectively; P = .046) and HOOS-Quality of Life (49.7 ± 18.8 vs 34.6 ± 22.0, respectively; P = .030) scores.ConclusionArthroscopic treatment for acetabular retroversion is safe and provides significant clinical improvement similar to arthroscopic treatment for pincer-type FAI. Patients with acetabular retroversion who also underwent arthroscopic subspine decompression demonstrated greater improvements in pain and quality of life outcomes than those who underwent arthroscopic treatment without subspine decompression
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