1,033 research outputs found

    Growing Older, Staying Strong: Preventing Sarcopenia Through Strength Training

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    Older people can reduce their frailty, become more mobile and stave off the muscle-wasting condition known as sarcopenia by working out as little as twice a week

    Best Practices for Chiropractic Care of Children: A Consensus Update

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    AbstractObjectiveChiropractic care is the most common complementary and integrative medicine practice used by children in the United States, and it is used frequently by children internationally as well. The purpose of this project was to update the 2009 recommendations on best practices for chiropractic care of children.MethodsA formal consensus process was completed based on the existing recommendations and informed by the results of a systematic review of relevant literature from January 2009 through March 2015. The primary search question for the systematic review was, “What is the effectiveness of chiropractic care, including spinal manipulation, for conditions experienced by children (<18 years of age)?” A secondary search question was, “What are the adverse events associated with chiropractic care including spinal manipulation among children (<18 years of age)?” The consensus process was conducted electronically, by e-mail, using a multidisciplinary Delphi panel of 29 experts from 5 countries and using the RAND Corporation/University of California, Los Angeles, consensus methodology.ResultsOnly 2 statements from the previous set of recommendations did not reach 80% consensus on the first round, and revised versions of both were agreed upon in a second round.ConclusionsAll of the seed statements in this best practices document achieved a high level of consensus and thus represent a general framework for what constitutes an evidence-based and reasonable approach to the chiropractic management of infants, children, and adolescents

    Thermal duality and gravitational collapse

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    Thermal duality is a relationship between the behaviour of het-erotic string models of the E(8)xE(8) or SO(32) types at inversely related temperatures, a variant of T duality in the Euclidean regime. This duality would have consequences for the nature of the Hagedorn transition in these string models. We propose that the vacuum admits a family of deformations in situations where there are closed surfaces of constant area but high radial acceleration (a string regularized ver-sion of a Penrose trapped surface), such as would be formed in situ-ations of extreme gravitational collapse. This would allow a radical resolution of the ïŹrewall paradox by allowing quantum eïŹ€ects to sig-niïŹcantly modify the spacetime geometry around a collapsed object. A string bremsstrahlung process would convert the kinetic energy of infalling matter in extreme gravitational collapse to form a region of the deformed vacuum, which would be equivalent to forming a high temperature string phase. A heuristic criterion for the conversion pro-cess is presented, relating Newtonian gravity to the string tension, suggesting an upper limit to the strength of the gravitational interac-tion. This conversion process might have observable consequences for charged particles falling into a rotating collapsed object by producing high energy particles via a variant of the Penrose process

    Functional requirements for a Samd14-capping protein complex in stress erythropoiesis

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    Acute anemia induces rapid expansion of erythroid precursors and accelerated differentiation to replenish erythrocytes. Paracrine signals—involving cooperation between stem cell factor (SCF)/Kit signaling and other signaling inputs—are required for the increased erythroid precursor activity in anemia. Our prior work revealed that the sterile alpha motif (SAM) domain 14 (Samd14) gene increases the regenerative capacity of the erythroid system in a mouse genetic model and promotes stress-dependent Kit signaling. However, the mechanism underlying Samd14’s role in stress erythropoiesis is unknown. We identified a protein-protein interaction between Samd14 and the α- and ÎČ-heterodimers of the F-actin capping protein (CP) complex. Knockdown of the CP ÎČ subunit increased erythroid maturation in murine ex vivo cultures and decreased colony forming potential of stress erythroid precursors. In a genetic complementation assay for Samd14 activity, our results revealed that the Samd14-CP interaction is a determinant of erythroid precursor cell levels and function. Samd14-CP promotes SCF/Kit signaling in CD71med spleen erythroid precursors. Given the roles of Kit signaling in hematopoiesis and Samd14 in Kit pathway activation, this mechanism may have pathological implications in acute/chronic anemia

    Cognitive performance among carriers of pathogenic copy number variants: analysis of 152,000 UK Biobank subjects

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    Background The UK Biobank is a unique resource for biomedical research, with extensive phenotypic and genetic data on half a million adults from the general population. We aimed to examine the effect of neurodevelopmental copy number variants (CNVs) on the cognitive performance of participants. Methods We used Affymetrix Power Tools and PennCNV-Affy software to analyze Affymetrix microarrays of the first 152,728 genotyped individuals. We annotated a list of 93 CNVs and compared their frequencies with control datasets. We analyzed the performance on seven cognitive tests of carriers of 12 CNVs associated with schizophrenia (n = 1087) and of carriers of another 41 neurodevelopmental CNVs (n = 484). Results The frequencies of the 93 CNVs in the Biobank subjects were remarkably similar to those among 26,628 control subjects from other datasets. Carriers of schizophrenia-associated CNVs and of the group of 41 other neurodevelopmental CNVs had impaired performance on the cognitive tests, with nine of 14 comparisons remaining statistically significant after correction for multiple testing. They also had lower educational and occupational attainment (p values between 10−7 and 10−18). The deficits in cognitive performance were modest (Z score reductions between 0.01 and 0.51), compared with individuals with schizophrenia in the Biobank (Z score reductions between 0.35 and 0.90). Conclusions This is the largest study on the cognitive phenotypes of CNVs to date. Adult carriers of neurodevelopmental CNVs from the general population have significant cognitive deficits. The UK Biobank will allow unprecedented opportunities for analysis of further phenotypic consequences of CNVs

    Jointly estimating epidemiological dynamics of Covid-19 from case and wastewater data in Aotearoa New Zealand

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    Background: Timely and informed public health responses to infectious diseases such as COVID-19 necessitate reliable information about infection dynamics. The case ascertainment rate (CAR), the proportion of infections that are reported as cases, is typically much less than one and varies with testing practices and behaviours, making reported cases unreliable as the sole source of data. The concentration of viral RNA in wastewater samples provides an alternate measure of infection prevalence that is not affected by clinical testing, healthcare-seeking behaviour or access to care. Methods: We construct a state-space model with observed data of levels of SARS-CoV-2 in wastewater and reported case incidence and estimate the hidden states of the effective reproduction number, R, and CAR using sequential Monte Carlo methods. Results: We analyse data from 1 January 2022 to 31 March 2023 from Aotearoa New Zealand. Our model estimates that R peaks at 2.76 (95% CrI 2.20, 3.83) around 18 February 2022 and the CAR peaks around 12 March 2022. We calculate that New Zealand’s second Omicron wave in July 2022 is similar in size to the first, despite fewer reported cases. We estimate that the CAR in the BA.5 Omicron wave in July 2022 is approximately 50% lower than in the BA.1/BA.2 Omicron wave in March 2022. Conclusions: Estimating R, CAR, and cumulative number of infections provides useful information for planning public health responses and understanding the state of immunity in the population. This model is a useful disease surveillance tool, improving situational awareness of infectious disease dynamics in real-time

    Biotic interactions influence sediment erodibility on wave exposed sandflats

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    Biological activities in marine soft-sediments can modify the sedimentary environment through processes that change erosion rates. In low-energy environments, bioturbating macrofauna destabilizes sediments while microbes bind sediments and stabilize them. The degree to which these counter-acting processes influence sediment movement in a physically dynamic environment has not been well quantified. In a field experiment, we established 56 (1 m(2)) plots on an exposed intertidal sandflat. We used shade cloth and manipulated grazing pressure exerted by the deposit-feeding bivalve Macomona liliana (0-200 ind. m(-2)) to alter the microphytobenthic community. Three months post-manipulation, initiation of sediment transport (T-c) and change in sediment erosion rate with increasing bed shear stress (m(e)) were measured. Mean grain size, density of the spionid polychaete Aonides trifida, density of adult M. liliana, and bulk carbohydrate concentration could account for 54% of the variation in T-c (0.3-1.1 N m(-2) s(-1)). Mean grain size was the only significant predictor (p <= 0.01) of me explaining 22% of the variability (6-20 g N-1 s(-1)). T-c was negatively correlated with density of several abundant shallow- dwelling bioturbators (indicating sediment destabilization), but we did not observe the expected increase in T-c with microbial biomass. Furthermore, there was a positive correlation between adult M. liliana and T-c as well as evidence for several positive feedbacks between abundant shallow- dwelling macrofauna and microbial biomass. These study results demonstrate that despite frequent reworking by tidal currents and waves, bioturbating macrofauna are important to initiating sediment transport regardless of their effects on microbial biomass

    The Challenge of Implementing the Marine Ecosystem Service Concept

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    The concept of ecosystem services has gained traction as a means of linking societal benefits to the underlying ecology and functioning of ecosystems, and is now frequently included in decision-making and legislation. Moving the ecosystem service concept from theory into practice is now crucial. However, advancements in this area of research differ by ecosystem type, and marine systems lag significantly behind terrestrial counterparts in terms of understanding, implementation, and number of studies. In this paper we explore several reasons why ecosystem service research has been limited in marine systems and we outline the challenges that hinder progress. Marine systems suffer from a scarcity of spatial data relative to terrestrial counterparts. In terrestrial systems the spatial patterns of land-use/land-cover (LULC) are relatively straightforward to access via satellite and have been used as proxy indicators of service provisions. In contrast, remote sensing tools used to study the surface of the Earth are much less effective at capturing images of the seabed, and by extension marine habitats. Marine waters and their constituents are also frequently driven great distances by winds, tides, and currents. This creates a challenge for management as the identification and protection of areas where ecosystem services are exploited is not necessarily sufficient to ensure sustained service delivery. Further complications arise from the three-dimensional uses of marine systems, incorporating activities that use the sea surface, the water column and the benthic habitats below. Progress is being made as technological advancements are resulting in the acquisition of spatial data at faster rates and higher resolutions than previously possible. There is a growing capacity to map, model and value an increasing number of services with initiatives such as InVEST or principle-based modeling. We suggest that awareness is needed around the limited progress in marine systems as this could affect the way we value the biosphere and the relative proportion between biomes
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