286 research outputs found
Low-Intensity Vibration Protects the Weight-Bearing Skeleton and Suppresses Fracture Incidence in Boys With Duchenne Muscular Dystrophy: A Prospective, Randomized, Double-Blind, Placebo-Controlled Clinical Trial
The ability of low-intensity vibration (LIV) to combat skeletal decline in Duchenne Muscular Dystrophy (DMD) was evaluated in a randomized controlled trial. Twenty DMD boys were enrolled, all ambulant and treated with glucocorticoids (mean age 7.6, height-adjusted Z-scores [HAZ] of hip bone mineral density [BMD] â2.3). Ten DMD boys were assigned to stand for 10 min/d on an active LIV platform (0.4 g at 30 Hz), while 10 stood on a placebo device. Baseline and 14-month bone mineral content (BMC) and BMD of spine, hip, and total body were measured with DXA, and trabecular bone density (TBD) of tibia with quantitative computed tomography (QCT). All children tolerated the LIV intervention well, with daily compliance averaging 78%. At 14 months, TBD in the proximal and distal tibia remained unchanged in placebo subjects (â1.0% and â0.2%), while rising 3.5% and 4.6% in LIV subjects. HAZ for hip BMD and BMC in the placebo group declined 22% and 13%, respectively, contrasting with no change from baseline (0.9% and 1.4%) in the LIV group. Fat mass in the leg increased 32% in the placebo group, contrasting with 21% in LIV subjects. Across the 14-month study, there were four incident fractures in three placebo patients (30%), with no new fractures identified in LIV subjects. Despite these encouraging results, a major limitation of the study isâdespite randomized enrollmentâthat there was a significant difference in age between the two cohorts, with the LIV group being 2.8y older, and thus at greater severity of disease. In sum, these data suggest that noninvasive LIV can help protect the skeleton of DMD children against the disease progression, the consequences of diminished load bearing, and the complications of chronic steroid use. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research
Commissioning and performance of the LHCb Silicon Tracker
The LHCb Silicon Tracker is a silicon micro-strip detector with a sensitive area of 12 m2 and a total of 272k readout channels. The Silicon Tracker consists of two parts that use different detector modules. The detector installation was completed by early summer 2008 and the commissioning without beam has reached its final stage, successfully overcoming most of the encountered problems. Currently, the detector has more than 99% of the channels fully functioning. Commissioning with particles has started using beam-induced events from the LHC injection tests in 2008 and 2009. These events allowed initial studies of the detector performance. Especially, the detector modules could be aligned with an accuracy of about 20ÎŒm. Furthermore, with the first beam collisions that took place end of 2009 we could further study the performance and improve the alignment of the detector
Recommendations for the assessment and monitoring of skeletal manifestations in children with Gaucher disease
Validation of ammonia diffusive and pumped samplers in a controlled atmosphere test facility using traceable Primary Standard Gas Mixtures
We report the determination of ammonia (NH3) diffusive sampling rates for six different designs of commercial
diffusive samplers (CEH ALPHA sampler, Gradko diffusion tube, Gradko DIFRAM-400, Passam ammonia sampler,and ICS Maugeri Radiello radial sampler (blue and white turbulence barriers)), together with the validation test results for a pumped sampler (CEH DELTA denuder). The devices were all exposed in the UK's National Physical Laboratory's (NPL) controlled atmosphere test facility (CATFAC). For each of the seven diffusive sampler exposure tests there were traceable concentrations of ammonia (in the range 3â25 ÎŒgmâ3) generated under well-defined conditions of temperature, relative humidity and wind speed, which are applicable to a variety of ambient monitoring environments. The sampler exposure time at each concentration was 28 days,
except for the radial devices, which were exposed for 14 days. The work relied on the dilution of newly developed
stable Primary Standard Gas Mixtures (PSMs) prepared by gravimetry in passivated gas cylinders as a method of improving the metrological traceability of ammonia measurements. The exposed diffusive samplers were sent blind to the participants for analysis and the reported NH3 concentrations were then compared against the known reference concentration. From the results for each sampler type a diffusive sampling rate was calculated and compared against the rate used routinely by the participants. Some measurement results were in good agreement with the known traceable reference concentration (particularly for one diffusive sampler design (ALPHA)), while other devices exhibited over-reading and under-reading (each with a clear bias). The new diffusive sampling rates determined in the laboratory study were then applied to measurements in a field comparison campaign, and this was found to deliver an improvement in agreement between the different devices deployed
Ants, Cataglyphis cursor, Use Precisely Directed Rescue Behavior to Free Entrapped Relatives
Although helping behavior is ubiquitous throughout the animal kingdom, actual rescue activity is particularly rare. Nonetheless, here we report the first experimental evidence that ants, Cataglyphis cursor, use precisely directed rescue behavior to free entrapped victims; equally important, they carefully discriminate between individuals in distress, offering aid only to nestmates. Our experiments simulate a natural situation, which we often observed in the field when collecting Catagyphis ants, causing sand to collapse in the process. Using a novel experimental technique that binds victims experimentally, we observed the behavior of separate, randomly chosen groups of 5 C. cursor nestmates under one of six conditions. In five of these conditions, a test stimulus (the âvictimâ) was ensnared with nylon thread and held partially beneath the sand. The test stimulus was either (1) an individual from the same colony; (2) an individual from a different colony of C cursor; (3) an ant from a different ant species; (4) a common prey item; or, (5) a motionless (chilled) nestmate. In the final condition, the test stimulus (6) consisted of the empty snare apparatus. Our results demonstrate that ants are able to recognize what, exactly, holds their relative in place and direct their behavior to that object, the snare, in particular. They begin by excavating sand, which exposes the nylon snare, transporting sand away from it, and then biting at the snare itself. Snare biting, a behavior never before reported in the literature, demonstrates that rescue behavior is far more sophisticated, exact and complexly organized than the simple forms of helping behavior already known, namely limb pulling and sand digging. That is, limb pulling and sand digging could be released directly by a chemical call for help and thus result from a very simple mechanism. However, it's difficult to see how this same releasing mechanism could guide rescuers to the precise location of the nylon thread, and enable them to target their bites to the thread itself
Translations of new public management: a decentred approach to school governance in four OECD countries
Despite the prevalence of corporate and performative models of school governance within and across different education systems, there are various cases of uneven, hybrid expressions of New Public Management (NPM) that reveal the contingency of global patterns of rule. Adopting a âdecentred approachâ to governance (Bevir, M. 2010. âRethinking Governmentality: Towards Genealogies of Governance.â European Journal of Social Theory 13 (4): 423â441), this paper compares the development of NPM in four OECD countries: Australia, England, Spain, and Switzerland. A focus of the paper is how certain policy instruments are created and sustained within highly differentiated geo-political settings and through different multi-scalar actors and authorities yet modified to reflect established traditions and practices
Best practice data life cycle approaches for the life sciences
Throughout history, the life sciences have been revolutionised by technological advances; in our era this is manifested by advances in instrumentation for data generation, and consequently researchers now routinely handle large amounts of heterogeneous data in digital formats. The simultaneous transitions towards biology as a data science and towards a âlife cycleâ view of research data pose new challenges. Researchers face a bewildering landscape of data management requirements, recommendations and regulations, without necessarily being able to access data management training or possessing a clear understanding of practical approaches that can assist in data management in their particular research domain. Here we provide an overview of best practice data life cycle approaches for researchers in the life sciences/bioinformatics space with a particular focus on âomicsâ datasets and computer-based data processing and analysis. We discuss the different stages of the data life cycle and provide practical suggestions for useful tools and resources to improve data management practices.Philippa C. Griffin, Jyoti Khadake, Kate S. LeMay, Suzanna E. Lewis, Sandra Orchard ... Nathan S. Watson-Haigh ... et al
Symmetry breaking in mass-recruiting ants: extent of foraging biases depends on resource quality
The communication involved in the foraging behaviour of social insects is integral to their success. Many ant species use trail pheromones to make decisions about where to forage. The strong positive feedback caused by the trail pheromone is thought to create a decision between two or more options. When the two options are of identical quality, this is known as symmetry breaking, and is important because it helps colonies to monopolise food sources in a competitive environment. Symmetry breaking is thought to increase with the quantity of pheromone deposited by ants, but empirical studies exploring the factors affecting symmetry breaking are limited. Here, we tested if (i) greater disparity between two food sources increased the degree to which a higher quality food source is favoured and (ii) if the quality of identical food sources would affect the degree of symmetry breaking that occurs. Using the mass-recruiting Pharaoh ant, Monomorium pharaonis, we carried out binary choice tests to investigate how food quality affects the choice and distribution of colony foraging decisions. We found that colonies could coordinate foraging to exploit food sources of greater quality, and a greater contrast in quality between the food sources created a stronger collective decision. Contrary to prediction, we found that symmetry breaking decreased as the quality of two identical food sources increased. We discuss how stochastic effects might lead to relatively strong differences in the amount of pheromone on alternative routes when food source quality is low. Significance statement: Pheromones used by social insects should guide a colony via positive feedback to distribute colony members at resources in the most adaptive way given the current environment. This study shows that when food resources are of equal quality, Pharaoh ant foragers distribute themselves more evenly if the two food sources are both of high quality compared to if both are of low quality. The results highlight the way in which individual ants can modulate their response to pheromone trails which may lead colonies to exploiting resources more evenly when in a resource rich environment
Natural IgE production in the absence of MHC Class II cognate help
IgE induction by parasites and allergens is antigen driven and cognate T cell help dependent. We demonstrate that spontaneously produced IgE in T cell-deficient and germ-free wild-type (wt) mice is composed of natural specificities and induced by a mechanism independent of MHC class II (MHC II) cognate help. This does not require secondary lymphoid structures or germinal center formation, although some bystander T cell-derived IL-4 is necessary. The pathway of spontaneous IgE production is not inhibited by regulatory T cells and increases with age to constitute significant serum concentrations, even in naive animals
Marburg virus survivor immune responses are Th1 skewed with limited neutralizing antibody responses.
Until recently, immune responses in filovirus survivors remained poorly understood. Early studies revealed IgM and IgG responses to infection with various filoviruses, but recent outbreaks have greatly expanded our understanding of filovirus immune responses. Immune responses in survivors of Ebola virus (EBOV) and Sudan virus (SUDV) infections have provided the most insight, with T cell responses as well as detailed antibody responses having been characterized. Immune responses to Marburg virus (MARV), however, remain almost entirely uncharacterized. We report that immune responses in MARV survivors share characteristics with EBOV and SUDV infections but have some distinct differences. MARV survivors developed multivariate CD4+ T cell responses but limited CD8+ T cell responses, more in keeping with SUDV survivors than EBOV survivors. In stark contrast to SUDV survivors, rare neutralizing antibody responses in MARV survivors diminished rapidly after the outbreak. These results warrant serious consideration for any vaccine or therapeutic that seeks to be broadly protective, as different filoviruses may require different immune responses to achieve immunity
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