530 research outputs found

    Changes in children’s cognitive development at the Start of School in England 2001–2008.

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    Since 1997, England has seen massive changes in the Early Years including the introduction of an early childhood curriculum, free pre-school education for three-year-olds and local programmes for disadvantaged communities. Many of these initiatives took time to introduce and become established. Beginning in 2001, and each year thereafter until 2008, the authors collected consistent data from thousands of children when they started school at the age of four on a range of variables, chosen because they are good predictors of later success. These included vocabulary, early reading and early mathematics. Children from the same set of 472 state primary schools in England were assessed each year. This paper contributes to the existing studies of educational trends over time by examining the extent to which children's scores on these measures changed over that period; in general, they were found to have remained stable

    Multiscale computational analysis of Xenopus laevis morphogenesis reveals key insights of systems-level behavior

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    <p>Abstract</p> <p>Background</p> <p>Tissue morphogenesis is a complex process whereby tissue structures self-assemble by the aggregate behaviors of independently acting cells responding to both intracellular and extracellular cues in their environment. During embryonic development, morphogenesis is particularly important for organizing cells into tissues, and although key regulatory events of this process are well studied in isolation, a number of important systems-level questions remain unanswered. This is due, in part, to a lack of integrative tools that enable the coupling of biological phenomena across spatial and temporal scales. Here, we present a new computational framework that integrates intracellular signaling information with multi-cell behaviors in the context of a spatially heterogeneous tissue environment.</p> <p>Results</p> <p>We have developed a computational simulation of mesendoderm migration in the <it>Xenopus laevis </it>explant model, which is a well studied biological model of tissue morphogenesis that recapitulates many features of this process during development in humans. The simulation couples, via a JAVA interface, an ordinary differential equation-based mass action kinetics model to compute intracellular Wnt/β-catenin signaling with an agent-based model of mesendoderm migration across a fibronectin extracellular matrix substrate. The emergent cell behaviors in the simulation suggest the following properties of the system: maintaining the integrity of cell-to-cell contact signals is necessary for preventing fractionation of cells as they move, contact with the Fn substrate and the existence of a Fn gradient provides an extracellular feedback loop that governs migration speed, the incorporation of polarity signals is required for cells to migrate in the same direction, and a delicate balance of integrin and cadherin interactions is needed to reproduce experimentally observed migratory behaviors.</p> <p>Conclusion</p> <p>Our computational framework couples two different spatial scales in biology: intracellular with multicellular. In our simulation, events at one scale have quantitative and dynamic impact on events at the other scale. This integration enables the testing and identification of key systems-level hypotheses regarding how signaling proteins affect overall tissue-level behavior during morphogenesis in an experimentally verifiable system. Applications of this approach extend to the study of tissue patterning processes that occur during adulthood and disease, such as tumorgenesis and atherogenesis.</p

    Longitudinal assessment of neuronal 3D genomes in mouse prefrontal cortex

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    Neuronal epigenomes, including chromosomal loopings moving distal cis-regulatory elements into proximity of target genes, could serve as molecular proxy linking present-day-behaviour to past exposures. However, longitudinal assessment of chromatin state is challenging, because conventional chromosome conformation capture assays essentially provide single snapshots at a given time point, thus reflecting genome organization at the time of brain harvest and therefore are non-informative about the past. Here we introduce ‘NeuroDam’ to assess epigenome status retrospectively. Short-term expression of the bacterial DNA adenine methyltransferase Dam, tethered to the Gad1 gene promoter in mouse prefrontal cortex neurons, results in stable G[superscriptmethyl]ATC tags at Gad1-bound chromosomal contacts. We show by NeuroDam that mice with defective cognition 4 months after pharmacological NMDA receptor blockade already were affected by disrupted chromosomal conformations shortly after drug exposure. Retrospective profiling of neuronal epigenomes is likely to illuminate epigenetic determinants of normal and diseased brain development in longitudinal context.United States. National Institutes of Healt

    More or less likely to offend? Young adults with a history of identified Developmental Language Disorder

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    Background: There is now substantial literature demonstrating that a disproportionate number of young people who come into contact with youth justice services evidence unidentified language difficulties. These young people, therefore, have received little or no professional input in this area. Conversely, there is a dearth of research pertaining to criminality outcomes among those individuals with identified developmental language disorders who have received such interventions. Aims: The paper examines police-initiated contact and substance use outcomes of young adults with a history of identified developmental language disorders (DLD) versus age matched peers (AMPs). Additionally, self-reported rule breaking behaviours and aggression are considered. We hypothesise that early identification/intervention reduces engagement with risky behaviour such as substance and alcohol use as well as offending-related behaviours. Methods & Procedures: Adversarial police-initiated contacts were examined in 84 young adults with a history of DLD and 88 AMPs. Rule-breaking and aggression were evaluated using the Achenbach Adult Self-Report for ages 18-59. Outcomes & Results: Adults with a history of DLD, who received targeted intervention during their school years, reported less contact with their local police service compared to AMPs at age 24. Comparable proportions of both groups reported current alcohol consumption but group differences were found relating to alcohol use. No group differences in rule breaking behaviours were found but the DLD group was found to have a statistically significant higher raw score on the aggressive behaviour scale. Conclusions & Implications: There is a need for early identification of children with DLD. Early intervention aimed at ameliorating such difficulties could possibly have distal outcomes in relation to offending

    The timing of anthropogenic emergence in simulated climate extremes

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    Determining the time of emergence of climates altered from their natural state by anthropogenic influences can help inform the development of adaptation and mitigation strategies to climate change. Previous studies have examined the time of emergence of climate averages. However, at the global scale, the emergence of changes in extreme events, which have the greatest societal impacts, has not been investigated before. Based on state-of-the-art climate models, we show that temperature extremes generally emerge slightly later from their quasi-natural climate state than seasonal means, due to greater variability in extremes. Nevertheless, according to model evidence, both hot and cold extremes have already emerged across many areas. Remarkably, even precipitation extremes that have very large variability are projected to emerge in the coming decades in Northern Hemisphere winters associated with a wettening trend. Based on our findings we expect local temperature and precipitation extremes to already differ significantly from their previous quasi-natural state at many locations or to do so in the near future. Our findings have implications for climate impacts and detection and attribution studies assessing observed changes in regional climate extremes by showing whether they will likely find a fingerprint of anthropogenic climate change

    The Suppressor of AAC2 Lethality SAL1 Modulates Sensitivity of Heterologously Expressed Artemia ADP/ATP Carrier to Bongkrekate in Yeast

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    The ADP/ATP carrier protein (AAC) expressed in Artemia franciscana is refractory to bongkrekate. We generated two strains of Saccharomyces cerevisiae where AAC1 and AAC3 were inactivated and the AAC2 isoform was replaced with Artemia AAC containing a hemagglutinin tag (ArAAC-HA). In one of the strains the suppressor of ΔAAC2 lethality, SAL1, was also inactivated but a plasmid coding for yeast AAC2 was included, because the ArAACΔsal1Δ strain was lethal. In both strains ArAAC-HA was expressed and correctly localized to the mitochondria. Peptide sequencing of ArAAC expressed in Artemia and that expressed in the modified yeasts revealed identical amino acid sequences. The isolated mitochondria from both modified strains developed 85% of the membrane potential attained by mitochondria of control strains, and addition of ADP yielded bongkrekate-sensitive depolarizations implying acquired sensitivity of ArAAC-mediated adenine nucleotide exchange to this poison, independent from SAL1. However, growth of ArAAC-expressing yeasts in glycerol-containing media was arrested by bongkrekate only in the presence of SAL1. We conclude that the mitochondrial environment of yeasts relying on respiratory growth conferred sensitivity of ArAAC to bongkrekate in a SAL1-dependent manner. © 2013 Wysocka-Kapcinska et al
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