509 research outputs found

    Primary versus Staged Closure of Exomphalos Major: Cardiac Anomalies Do Not Affect Outcome

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    Aim: The objective of the study is to describe management of exomphalos major and investigate the effect of congenital cardiac anomalies. / Methods: A single-center retrospective review (with audit approval) was performed of neonates with exomphalos major (fascial defect ≥ 5cm ± liver herniation) between 2004 and 2014. Demographic and operative data were collected and outcomes compared between infants who had primary or staged closure. Data, median (range), were analyzed appropriately. Results: A total of 22 patients were included, 20 with liver herniation and 1 with pentalogy of Cantrell. Gestational age was 38 (30–40) weeks, birth weight 2.7 (1.4–4.6) kg, and 13 (60%) were male. Two were managed conservatively due to severe comorbidities, 5 underwent primary closure, and 15 had application of Prolene (Ethicon Inc) mesh silo and serial reduction. Five died, including two managed conservatively, none primarily of the exomphalos. Survivors were followed up for 38 months (2–71). Cardiac anomalies were present in 20 (91%) patients: 8 had minor and 12 major anomalies. Twelve (55%) patients had other anomalies. Primary closure was associated with shorter length of stay (13 vs. 85 days, p = 0.02), but infants had similar lengths of intensive care stay, duration of parenteral feeds, and time to full feeds. Infants with cardiac anomalies had shorter times to full closure (28 vs. 62 days, p = 0.03), but other outcomes were similar. / Conclusion: Infants whose defect can be closed primarily have a shorter length of stay, but other outcomes are similar. Infants with more significant abdominovisceral disproportion are managed with staged closure; the presence of major cardiac anomalies does not affect surgical outcome

    On the Importance of Countergradients for the Development of Retinotopy: Insights from a Generalised Gierer Model

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    During the development of the topographic map from vertebrate retina to superior colliculus (SC), EphA receptors are expressed in a gradient along the nasotemporal retinal axis. Their ligands, ephrin-As, are expressed in a gradient along the rostrocaudal axis of the SC. Countergradients of ephrin-As in the retina and EphAs in the SC are also expressed. Disruption of any of these gradients leads to mapping errors. Gierer's (1981) model, which uses well-matched pairs of gradients and countergradients to establish the mapping, can account for the formation of wild type maps, but not the double maps found in EphA knock-in experiments. I show that these maps can be explained by models, such as Gierer's (1983), which have gradients and no countergradients, together with a powerful compensatory mechanism that helps to distribute connections evenly over the target region. However, this type of model cannot explain mapping errors found when the countergradients are knocked out partially. I examine the relative importance of countergradients as against compensatory mechanisms by generalising Gierer's (1983) model so that the strength of compensation is adjustable. Either matching gradients and countergradients alone or poorly matching gradients and countergradients together with a strong compensatory mechanism are sufficient to establish an ordered mapping. With a weaker compensatory mechanism, gradients without countergradients lead to a poorer map, but the addition of countergradients improves the mapping. This model produces the double maps in simulated EphA knock-in experiments and a map consistent with the Math5 knock-out phenotype. Simulations of a set of phenotypes from the literature substantiate the finding that countergradients and compensation can be traded off against each other to give similar maps. I conclude that a successful model of retinotopy should contain countergradients and some form of compensation mechanism, but not in the strong form put forward by Gierer

    Quantum Acoustics with Surface Acoustic Waves

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    It has recently been demonstrated that surface acoustic waves (SAWs) can interact with superconducting qubits at the quantum level. SAW resonators in the GHz frequency range have also been found to have low loss at temperatures compatible with superconducting quantum circuits. These advances open up new possibilities to use the phonon degree of freedom to carry quantum information. In this paper, we give a description of the basic SAW components needed to develop quantum circuits, where propagating or localized SAW-phonons are used both to study basic physics and to manipulate quantum information. Using phonons instead of photons offers new possibilities which make these quantum acoustic circuits very interesting. We discuss general considerations for SAW experiments at the quantum level and describe experiments both with SAW resonators and with interaction between SAWs and a qubit. We also discuss several potential future developments.Comment: 14 pages, 12 figure

    Gender politics in 21st century literacy reform

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    From 2001 to 2004 Education Queensland undertook significant literacy reform in schools through the Literate Futures Project. Research into the impact of this reform has revealed that significant demands were placed on women at all levels, from those producing resources to those leading change within schools. Although the reform was a government response to globalisation, many women were driven by a commitment to a collaborative approach to professional learning that addressed equity and improving educational outcomes for all students. But what was the cost of this commitment to the project? Failure to acknowledge the emotion work demanded by educational reform effectively silences women and the significant contribution they make. This paper examining a 21st century literacy reform draws on the work of Fraser and Boler to argue for gender justice and acknowledgement of emotion work

    Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

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    Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures

    On staying grounded and avoiding Quixotic dead ends

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    The 15 articles in this special issue on The Representation of Concepts illustrate the rich variety of theoretical positions and supporting research that characterize the area. Although much agreement exists among contributors, much disagreement exists as well, especially about the roles of grounding and abstraction in conceptual processing. I first review theoretical approaches raised in these articles that I believe are Quixotic dead ends, namely, approaches that are principled and inspired but likely to fail. In the process, I review various theories of amodal symbols, their distortions of grounded theories, and fallacies in the evidence used to support them. Incorporating further contributions across articles, I then sketch a theoretical approach that I believe is likely to be successful, which includes grounding, abstraction, flexibility, explaining classic conceptual phenomena, and making contact with real-world situations. This account further proposes that (1) a key element of grounding is neural reuse, (2) abstraction takes the forms of multimodal compression, distilled abstraction, and distributed linguistic representation (but not amodal symbols), and (3) flexible context-dependent representations are a hallmark of conceptual processing

    Mental health literacy of depression: gender differences and attitudinal antecedents in a representative British sample

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    Background Poor mental health literacy and negative attitudes toward individuals with mental health disorders may impede optimal help-seeking for symptoms of mental ill-health. The present study examined the ability to recognize cases of depression as a function of respondent and target gender, as well as individual psychological differences in attitudes toward persons with depression. Methods In a representative British general population survey, the ability to correctly recognize vignettes of depression was assessed among 1,218 adults. Respondents also rated the vignettes along a number of attitudinal dimensions and completed measures of attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes. Results There were significant differences in the ability to correctly identify cases of depression as a function of respondent and target gender. Respondents were more likely to indicate that a male vignette did not suffer from a mental health disorder compared to a female vignette, and women were more likely than men to indicate that the male vignette suffered from a mental health disorder. Attitudes toward persons with depression were associated with attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes. Conclusion Initiatives that consider the impact of gender stereotypes as well as individual differences may enhance mental health literacy, which in turn is associated with improved help-seeking behaviors for symptoms of mental ill-health

    Long-term field performance of a polyester-based long-lasting insecticidal mosquito net in rural Uganda

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    <p>Abstract</p> <p>Background</p> <p>In order to evaluate whether criteria for LLIN field performance (phase III) set by the WHO Pesticide Evaluation Scheme are met, first and second generations of one of these products, PermaNet<sup>®</sup>, a polyester net using the coating technology were tested.</p> <p>Methods</p> <p>A randomized, double blinded study design was used comparing LLIN to conventionally treated nets and following LLIN for three years under regular household use in rural conditions. Primary outcome measures were deltamethrin residue and bioassay performance (60 minute knock-down and 24 hour mortality after a three minute exposure) using a strain of <it>Anopheles gambiae s.s</it>. sensitive to pyrethroid insecticides.</p> <p>Results</p> <p>Baseline concentration of deltamethrin was within targets for all net types but was rapidly lost in conventionally treated nets and first generation PermaNet<sup>® </sup>with median of 0.7 and 2.5 mg/m<sup>2 </sup>after six months respectively. In contrast, second generation PermaNet<sup>® </sup>retained insecticide well and had 41.5% of baseline dose after 36 months (28.7 mg/m<sup>2</sup>). Similarly, vector mortality and knockdown dropped to 18% and 70% respectively for first generation LLIN after six months but remained high (88.5% and 97.8% respectively) for second generation PermaNet<sup>® </sup>after 36 months of follow up at which time 90.0% of nets had either a knockdown rate ≥ 95% or mortality rate ≥ 80%.</p> <p>Conclusion</p> <p>Second generation PermaNet<sup>® </sup>showed excellent results after three years of field use and fulfilled the WHOPES criteria for LLIN. Loss of insecticide on LLIN using coating technology under field conditions was far more influenced by factors associated with handling rather than washing.</p
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