709 research outputs found

    The potential of mathematical picture books: a systematic analysis of their domain-specific picture book features

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    Studies in the domain of early literacy and recently also mathematics point to the potential of picture book reading (PBR) activities for children’s early literacy resp. mathematical development. Contrasting the domain of early literacy, the contribution of picture book features to the effectiveness of PBR activities in the domain of mathematics is hardly studied. To increase our understanding of the topic, we systematically analysed the domain-specific features of 100 mathematical picture books. Our analyses pointed to the presence of features that previous studies assume to support and to hinder early mathematical development (Ward et al., 2017). These findings complement previous findings based on English mathematical picture books from the U.S. and offer important insights for future studies and educational practice

    Evaluation of risk based microbiological criteria for Campylobacter in broiler carcasses in Belgium using TRiMiCri

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    Campylobacteriosis is the most frequently reported foodborne zoonosis worldwide. Consumer´s exposure to Campylobacter might be reduced by establishing a microbiological criterion (MC) for Campylobacter on broiler meat. In the present study two possible approaches were evaluated, using the freely available software tool for risk based microbiological criteria TRiMiCri (http://tools.food.dtu.dk/trimicri). The first approach was the traditional one that implies a microbiological limit (ML-MC) and the second one which is based on the relative risk estimate (RRL-MC). The analyses were based on Campylobacter quantitative data collected from 28 Campylobacter positive bathes processed in 6 Belgian broiler slaughterhouses. To evaluate the performance of ML-MC, n=6, different c (0,1,2) and m (100,1 000,10 000) were used. Results showed that more than 90% of Campylobacter positive batches were not complying with strict ML criteria based on the m=100 for all applied combination of c. The RRL approach requires a baseline risk which was estimated based on the Campylobacter baseline data collected in Belgium in 2008. Approximately 60% of evaluated Campylobacter positive batches account for higher risk than the baseline risk. For both approaches, application of less stringent criteria results in lower percentage of NC and higher minimum relative residual risks (MRRR; it refers to the change in risk when all batches are sampled and all NC batches undergo treatment that effectively eliminates Campylobacter so they are replaced by zero risk batches). It was also observed that the number of samples (n) had little effect on risk estimates. Additionally, the results from ML-MC and RRL-MC follow the same curve when plotting percentage of NC against MRRR. However, for RRL-MC the percentage of NC batches and MRRR was lower and higher, respectively. To conclude, obtained results indicate that TRiMiCri is a useful and user friendly tool to make a risk based decision on the choice of the MC

    The use of computer simulation modeling to estimate complications in patients with type 2 diabetes mellitus : comparative validation of the cornerstone diabetes simulation model

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    Objective The objective of this study was to assess the validity of the Cornerstone Diabetes Simulation (CDS), a Microsoft Excel(R)-based patient-level simulation for type 2 diabetes mellitus based on risk equations from the revised United Kingdom Prospective Diabetes Study Outcomes Model (UKPDS-OM2, also known as UKPDS 82). Methods Three levels of validation were conducted. Internal validation was assessed through independent review and model stress-testing. External validation was addressed by populating the CDS with baseline characteristics and treatment effects from three major diabetes clinical trials used in the Fifth Mount Hood Diabetes Challenge (MH5) for computer simulation models. Cross-validation of predicted outcomes was tested versus eight models that participated in the MH5. Simulated results were compared with observed clinical outcomes via the coefficient of determination (R-2) for both the absolute risk of each clinical outcome and the difference in absolute risk between control and intervention arm in each trial. We ensured transparency of all model inputs and assumptions in reporting. Results The CDS could be used to predict 18 of 39 single and composite endpoints across the three trials. The model obtained an R-2 of 0.637 for predicted versus observed absolute risks, and an R-2 of 0.442 for predicted versus observed risk differences between control and intervention. Among the other eight models, only one obtained a higher R-2 value under both definitions, albeit based on only four predicted endpoints. Conclusions The CDS provides good predictions of diabetes-related complications when compared to observed trial outcomes and previously validated models. The model has value as a validated tool in cost-effectiveness evaluations

    In situ reduction of charge noise in GaAs/AlGaAs Schottky-gated devices

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    We show that an insulated electrostatic gate can be used to strongly suppress ubiquitous background charge noise in Schottky-gated GaAs/AlGaAs devices. Via a 2-D self-consistent simulation of the conduction band profile we show that this observation can be explained by reduced leakage of electrons from the Schottky gates into the semiconductor through the Schottky barrier, consistent with the effect of "bias cooling". Upon noise reduction, the noise power spectrum generally changes from Lorentzian to 1/f1/f type. By comparing wafers with different Al content, we exclude that DX centers play a dominant role in the charge noise.Comment: 4 pages, 3 figure

    Schmidt balls around the identity

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    Robustness measures as introduced by Vidal and Tarrach [PRA, 59, 141-155] quantify the extent to which entangled states remain entangled under mixing. Analogously, we introduce here the Schmidt robustness and the random Schmidt robustness. The latter notion is closely related to the construction of Schmidt balls around the identity. We analyse the situation for pure states and provide non-trivial upper and lower bounds. Upper bounds to the random Schmidt-2 robustness allow us to construct a particularly simple distillability criterion. We present two conjectures, the first one is related to the radius of inner balls around the identity in the convex set of Schmidt number n-states. We also conjecture a class of optimal Schmidt witnesses for pure states.Comment: 7 pages, 1 figur

    Genomics of clinal local adaptation in Pinus sylvestris under continuous environmental and spatial genetic setting

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    Understanding the consequences of local adaptation at the genomic diversity is a central goal in evolutionary genetics of natural populations. In species with large continuous geographical distributions the phenotypic signal of local adaptation is frequently clear, but the genetic basis often remains elusive. We examined the patterns of genetic diversity inPinus sylvestris, a keystone species in many Eurasian ecosystems with a huge distribution range and decades of forestry research showing that it is locally adapted to the vast range of environmental conditions. MakingP. sylvestrisan even more attractive subject of local adaptation study, population structure has been shown to be weak previously and in this study. However, little is known about the molecular genetic basis of adaptation, as the massive size of gymnosperm genomes has prevented large scale genomic surveys. We generated a both geographically and genomically extensive dataset using a targeted sequencing approach. By applying divergence-based and landscape genomics methods we identified several loci contributing to local adaptation, but only few with large allele frequency changes across latitude. We also discovered a very large (ca. 300 Mbp) putative inversion potentially under selection, which to our knowledge is the first such discovery in conifers. Our results call for more detailed analysis of structural variation in relation to genomic basis of local adaptation, emphasize the lack of large effect loci contributing to local adaptation in the coding regions and thus point out the need for more attention toward multi-locus analysis of polygenic adaptation

    The impact of integrated prevention and treatment on child malnutrition and health: the PROMIS project, a randomized control trial in Burkina Faso and Mali

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    Abstract Background Evidence suggests that both preventive and curative nutrition interventions are needed to tackle child acute malnutrition (AM) in developing countries. In addition to reducing the incidence of AM, providing preventive interventions may also help increase attendance (and coverage) of AM screening, a major constraint in the community-based management of child acute malnutrition (CMAM) model. There is a paucity of evidence-based strategies to deliver integrated preventive and curative interventions effectively and affordably at scale. The aim of the Innovative Approaches for the Prevention of Childhood Malnutrition (PROMIS) study is to assess the feasibility, quality of implementation, effectiveness and cost-effectiveness of an integrated child malnutrition prevention and treatment intervention package implemented through a community-based platform in Mali and a facility-based platform in Burkina Faso. Methods/Design The PROMIS intervention entails a comprehensive preventive package offered on a monthly basis to caregivers of children, while children are screened for acute malnutrition (AM). The package consists of behavior change communication on essential nutrition and hygiene actions, and monthly preventive doses of small quantity lipid-based nutrient supplements (SQ-LNS) for children aged 6 to 23.9 months. Positive AM cases are referred to treatment services offered by first-line health services according to the CMAM model. The PROMIS intervention will be evaluated using a mixed methods approach. The impact study encompasses two types of study design: i) repeated cross-sectional surveys conducted at baseline and at endline after 24 months of program implementation and ii) a longitudinal study with a monthly follow-up for 18 months. Primary study impact measures include the incidence and endpoint prevalence of AM, AM screening coverage and treatment compliance. A process evaluation will assess the feasibility and quality of implementation of the intervention guided by country specific program impact pathways (PIPs). Cost-effectiveness analysis will assess the economic feasibility of the intervention. Discussion The PROMIS study assesses the effectiveness of an innovative model to integrate prevention and treatment interventions for greater and more sustainable impacts on the incidence and prevalence of AM using a rigorous, theory-based randomized control trial approach. This type of programmatic research is urgently needed to help program implementers, policy makers, and investors prioritize, select and scale-up the best program models to prevent and treat AM and achieve the World Health Assembly goal of reducing childhood wasting to less than 5% globally by the year 2025. Trial registration Clinicaltrials.gov NCT02323815 (registered on December 18, 2014) and NCT02245152 (registered on September 16, 2014

    A techno-economic and life cycle assessment for the production of green methanol from CO2: catalyst and process bottlenecks

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    The success of catalytic schemes for the large-scale valorization of CO2 does not only depend on the development of active, selective and stable catalytic materials but also on the overall process design. Here we present a multidisciplinary study (from catalyst to plant and techno-economic/lifecycle analysis) for the production of green methanol from renewable H2 and CO2. We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts (InCo) with a thorough process simulation and techno-economic assessment. We then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO2. Our results indicate that up to 1.75 ton of CO2 can be abated per ton of produced methanol only if renewable energy is used to run the process, while the sensitivity analysis suggest that either rock-bottom H2 prices (1.5 kg−1)orsevereCO2taxation(300 kg−1) or severe CO2 taxation (300 per ton) are needed for a profitable methanol plant. Besides, we herein highlight and analyze some critical bottlenecks of the process. Especial attention has been paid to the contribution of H2 to the overall plant costs, CH4 trace formation, and purity and costs of raw gases. In addition to providing important information for policy makers and industrialists, directions for catalyst (and therefore process) improvements are outlined.The authors gratefully acknowledge financial support from the King Abdullah University of Science and Technology (KAUST). T. Cordero-Lanzac and A.T. Aguayo acknowledge the financial support received from the Spanish Ministry of Science and Innovation with some ERDF funds (CTQ2016-77812-R) and the Basque Government (IT1218-19). T. Cordero-Lanzac also acknowledges the Spanish Ministry of Education, Culture and Sport for the award of his FPU grant (FPU15-01666). A. Navajas and L.M. Gandía gratefully acknowledge the financial support from Spanish Ministerio de Ciencia, Innovación y Universidades, and the European Regional Development Fund (ERDF/FEDER) (grant RTI2018-096294-B-C31). L.M. Gandía also thanks Banco de Santander and Universidad Pública de Navarra for their financial support under ‘’Programa de Intensificación de la Investigación 2018’ initiative

    Implementation of a Deutsch-like quantum algorithm utilizing entanglement at the two-qubit level, on an NMR quantum information processor

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    We describe the experimental implementation of a recently proposed quantum algorithm involving quantum entanglement at the level of two qubits using NMR. The algorithm solves a generalisation of the Deutsch problem and distinguishes between even and odd functions using fewer function calls than is possible classically. The manipulation of entangled states of the two qubits is essential here, unlike the Deutsch-Jozsa algorithm and the Grover's search algorithm for two bits.Comment: 4 pages, two eps figure
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