54 research outputs found
MO1 A Guide to Adjusting Survival Time Estimates to Account for Treatment Switching in Randomised Controlled Trials
Application of phage display to high throughput antibody generation and characterization.
We have created a high quality phage display library containing over 1010 human antibodies and describe its use in the generation of antibodies on an unprecedented scale. We have selected, screened and sequenced over 38,000 recombinant antibodies to 292 antigens, yielding over 7,200 unique clones. 4,400 antibodies were characterized by specificity testing and detailed sequence analysis and the data/clones are available online. Sensitive detection was demonstrated in a bead based flow cytometry assay. Furthermore, positive staining by immunohistochemistry on tissue microarrays was found for 37% (143/381) of antibodies. Thus, we have demonstrated the potential of and illuminated the issues associated with genome-wide monoclonal antibody generation.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
A Corporate Social Entrepreneurship Approach to Market-Based Poverty Reduction
In this article, we aim to conceptualize a market-based approach to poverty reduction from a corporate social entrepreneurship (CSE) perspective. Specifically, we describe some market-based initiatives at the base of the economic pyramid and relate them to the social entrepreneurship literature. We refer to the entrepreneurial activities of multinational corporations that create social value as CSE. We then conceptualize CSE according to the corporate entrepreneurship and social entrepreneurship domains and shed light on how corporations can implement CSE. Finally, by reviewing relevant literature, we propose some of the factors that can stimulate CSE in organizations and some of the benefits companies can gain by implementing CSE
Global data on earthworm abundance, biomass, diversity and corresponding environmental properties
14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change
Global maps of soil temperature.
Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km <sup>2</sup> resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km <sup>2</sup> pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications
A psicologia cognitiva experimental cinqüenta anos depois: a crise do paradigma do processamento de informação
Integrated global assessment of the natural forest carbon potential
Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2,3,4,5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets
The effects of an 8 week supplemented plyometric exercise training program on leg power, agility and speed in adolescent netball players
Objectives: Agility, speed and power are important aspects of almost every sport. One way to improve these attributes is plyometric exercise training. Plyometrics have shown to be effective for improving performance in many sports such as basketball, volleyball, and AFL. The aim of this study was to determine the effects of an 8 week supplementary plyometric exercise training program on the physical performance of adolescent athletes in the sport of netball.\ud
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Methods: Participants were randomly allocated to a control group (CG, n = 8) or an intervention group (IG, n = 8). All participants completed a battery of performance tests that included 10 m sprint, 505 agility, Illinois agility, vertical jump and 5 repetition one leg bounds. Both groups undertook the same netball training. The invention group also performed supplemental plyometric exercise training program over the 8 weeks training period. The plyometric exercises performed included: skipping, countermovement jumps, depth jumps and single leg bounds or alternate leg bounds. \ud
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Results: Following the 8 weeks of training all participants were retested and the intervention group demonstrated significant improvements in 505 agility (4.02%) and 5 single leg bounds (6.69%). \ud
Conclusions: It appears a supplemented plyometric exercise training program is of benefit to the adolescent netball player, for improving agility and power and it is recommended that this form of training be implemented into their normal training regime
Adjusting survival time estimates to account for treatment switching in randomised controlled trials – a simulation study
Abstract: Background Treatment switching commonly occurs in clinical trials of novel interventions,
particularly in the advanced or metastatic cancer setting, which causes important problems for health
technology assessment. It is unclear which methods to adjust for switching are most appropriate in
realistic scenarios.
Objectives: We aimed to assess statistical approaches for adjusting survival estimates in the
presence of treatment switching in order to determine which methods are most appropriate in a range
of realistic scenarios.
Methods: We conducted a simulation study to assess the bias, mean squared error and coverage
associated with alternative switching adjustment methods across a wide range of realistic scenarios.
Results Simple methods such as censoring or excluding patients that switch always resulted in high
levels of bias. More complex randomisation-based methods (e.g. Rank Preserving Structural Failure Time Models (RPSFTM)) were unbiased only when the treatment effect was not time-dependent.
Observational-based methods: (e.g. inverse probability of censoring weights (IPCW)) coped better with time-dependent treatment effects but are heavily data reliant, are sensitive to model misspecification and often produced high levels of bias in our simulations, particularly when the proportion of patients that switched treatments was very high (approximately 90%). We introduce a
novel “two stage” method, whereby a specific disease-related time-point is used to define a secondary
baseline after which switching is permitted, allowing treatment effects to be estimated separately for
patients that switch and patients randomised to the experimental group. We find that this method can
perform well provided the treatment switching mechanism is amenable.
Conclusions: Randomisation-based methods can accurately adjust for treatment switching when the treatment effect received by patients that switch is the same as that received by patients randomised to the experimental group. When this is not the case observational-based methods or simple twostage methods should be considered, although the IPCW is prone to substantial bias when the proportion of patients that switch is greater than approximately 90%. Simple methods such as censoring or excluding patients that switch should not be used
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