6,883 research outputs found

    Beginning to Dismantle the Binaries that Frame the Neoliberal Kindergarten

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    The binary logic of policymakers’ neoliberal reforms has restructured kindergarten into a learning environment where teachers struggle to nurture children as learners. At the same time, the critiques that challenge these policies are also rooted in this binary logic. This allows policymakers’ neoliberal reforms to remain intact. In this article, I address this issue through analysing findings from a larger research study that examined how a range of education stakeholders (n=88) made sense of the changed kindergarten through binary logic. I then take apart these three binaries that emerged in my analysis process to provide insight into possible pathways for change that education stakeholders at all levels of governance can begin to engage in to dismantle policymakers’ neoliberal education reforms

    Lifting classes for the fixed point theory of nn-valued maps

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    The theory of lifting classes and the Reidemeister number of single-valued maps of a finite polyhedron XX is extended to nn-valued maps by replacing liftings to universal covering spaces by liftings with codomain an orbit configuration space, a structure recently introduced by Xicot\'encatl. The liftings of an nn-valued map ff split into self-maps of the universal covering space of XX that we call lift-factors. An equivalence relation is defined on the lift-factors of ff and the number of equivalence classes is the Reidemeister number of ff. The fixed point classes of ff are the projections of the fixed point sets of the lift-factors and are the same as those of Schirmer. An equivalence relation is defined on the fundamental group of XX such that the number of equivalence classes equals the Reidemeister number. We prove that if XX is a manifold of dimension at least three, then algebraically the orbit configuration space approach is the same as one utilizing the universal covering space. The Jiang subgroup is extended to nn-valued maps as a subgroup of the group of covering transformations of the orbit configuration space and used to find conditions under which the Nielsen number of an nn-valued map equals its Reidemeister number. If an nn-valued map splits into nn single-valued maps, then its nn-valued Reidemeister number is the sum of their Reidemeister numbers.Comment: near complete rewrite from previous versio

    USE OF INHALANT ANESTHETICS IN THREE SNAKE SPECIES

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    Different snake species respond differently to various anesthetic agents. Hence, an anesthetic procedure developed for one species cannot necessarily be safely transferred to another species. The goal of this paper is to summarize our experience using inhalant anesthetics on three snake species, including both procedures that were successful and those we found to be less satisfactory. We found isoflurane delivered with a precision vaporizer to be the best agent to anesthetize black rat snakes (Elaphe o. obsoleta). Sex and mass did not seem to affect induction times in black rat snakes, but larger female rat snakes recovered faster from anesthesia than smaller females. Halothane delivered in the open method provided consistent anesthesia in northern water snakes (Nerodia s. sipedon), although it caused some mortality and should not be used on debilitated patients. Halothane delivered with a precision vaporizer may be used to anesthetize eastern massasauga rattlesnakes (Sistrurus c. catenatus). However, care must be taken to prevent mortality resulting from anesthetic overdose. Sex and mass had no effect on induction and recovery times in the rattlesnakes, but stressed animals require longer induction and recovery times

    Universally Sloppy Parameter Sensitivities in Systems Biology

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    Quantitative computational models play an increasingly important role in modern biology. Such models typically involve many free parameters, and assigning their values is often a substantial obstacle to model development. Directly measuring \emph{in vivo} biochemical parameters is difficult, and collectively fitting them to other data often yields large parameter uncertainties. Nevertheless, in earlier work we showed in a growth-factor-signaling model that collective fitting could yield well-constrained predictions, even when it left individual parameters very poorly constrained. We also showed that the model had a `sloppy' spectrum of parameter sensitivities, with eigenvalues roughly evenly distributed over many decades. Here we use a collection of models from the literature to test whether such sloppy spectra are common in systems biology. Strikingly, we find that every model we examine has a sloppy spectrum of sensitivities. We also test several consequences of this sloppiness for building predictive models. In particular, sloppiness suggests that collective fits to even large amounts of ideal time-series data will often leave many parameters poorly constrained. Tests over our model collection are consistent with this suggestion. This difficulty with collective fits may seem to argue for direct parameter measurements, but sloppiness also implies that such measurements must be formidably precise and complete to usefully constrain many model predictions. We confirm this implication in our signaling model. Our results suggest that sloppy sensitivity spectra are universal in systems biology models. The prevalence of sloppiness highlights the power of collective fits and suggests that modelers should focus on predictions rather than on parameters.Comment: Submitted to PLoS Computational Biology. Supplementary Information available in "Other Formats" bundle. Discussion slightly revised to add historical contex

    From Metabolism to Ecology:Cross-Feeding Interactions Shape the Balance between Polymicrobial Conflict and Mutualism

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    Polymicrobial interactions are widespread in nature, and play a major role in maintaining human health and ecosystems. Whenever one organism uses metabolites produced by another organism as energy or nutrient sources, this is called cross-feeding. The ecological outcomes of cross-feeding interactions are poorly understood and potentially diverse: mutualism, competition, exploitation or commensalism. A major reason for this uncertainty is the lack of theoretical approaches linking microbial metabolism to microbial ecology. To address this issue, we explore the dynamics of a one-way interspecific cross-feeding interaction, in which food can be traded for a service (detoxification). Our results show that diverse ecological interactions (competition, mutualism, exploitation) can emerge from this simple cross-feeding interaction, and can be predicted by the metabolic, demographic and environmental parameters that govern the balance of the costs and benefits of association. In particular, our model predicts stronger mutualism for intermediate by-product toxicity because the resource-service exchange is constrained to the service being neither too vital (high toxicity impairs resource provision) nor dispensable (low toxicity reduces need for service). These results support the idea that bridging microbial ecology and metabolism is a critical step towards a better understanding of the factors governing the emergence and dynamics of polymicrobial interactions

    Treatment for Anogenital Molluscum Contagiosum

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    There is no evidence from comparative trials to suggest a single best treatment method for anogenital molluscum contagiosum. Randomized controlled trials suggest self-administered topical imiquimod or podophyllotoxin cream is effective for resolving lesions. (Strength of Recommendation: B, based on inconsistent or limited quality patient-oriented evidence). There are no comparative trials of other commonly used treatments, such as carbon dioxide laser, cryotherapy, or curettage

    The impact of integrated infant and young child feeding and micronutrient powder intervention on feeding practices and anemia in children aged 6-23 months in Madagascar

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    This study assesses the impact of an integrated infant and young child feeding (IYCF) and micronutrient powder (MNP) intervention on children's risk of anemia and IYCF practices in Madagascar. Quantitative baseline and endline surveys were conducted in representative households with children 6-23 months from two districts, where an 18-month IYCF-MNP intervention was implemented. Relative risks comparing children's risk of anemia and maternal IYCF knowledge and practices at baseline versus endline, and also at endline among MNP-users versus non-users were estimated using log-binomial regression models. 372 and 475 children aged 6-23 months were assessed at baseline and endline respectively. Prevalence of anemia fell from 75.3% to 64.9% from baseline to endline (p = 0.002); the reduction in the risk of anemia remained significant in models adjusting for sociodemographic characteristics (ARR (95% CI): 0.86 (0.78, 0.95), p = 0.003). In endline assessments, 229 out of 474 (48.3%) of children had consumed MNPs. MNP-users had a lower risk of anemia (ARR (95% CI): 0.86 (0.74, 0.99), p = 0.04) than non-users, after controlling for child's dietary diversity and morbidity, maternal counseling by community-health-workers, and sociodemographic characteristics. Mothers interviewed at endline also had greater nutrition knowledge and were more likely to feed their children ≥4 food groups (ARR (95% CI): 2.92 (2.24, 3.80), p < 0.001), and the minimum acceptable diet (ARR (95% CI): 2.88 (2.17, 3.82), p < 0.001) than mothers interviewed at baseline. Integration of MNP into IYCF interventions is a viable strategy for improving children's consumption of micronutrients and reducing risk of anemia. The addition of MNP does not negatively impact, and may improve, IYCF practices.We are grateful to all of the mothers and children and participating communities, as well as data enumerators, and the USAID-supported SALOHI project team for the technical and financial support during the baseline and endline surveys. We also thank Jacky Raharinjatovo the PSI-Madagascar statistician for support in analyses as well as Roland Kupka, France Begin and Jennifer Marcy for their comments and feedback on this manuscript. The views expressed in this manuscript are those of the authors and do not necessarily reflect the official positions or policies of their affiliated institutions. Both the baseline and the endline surveys were funded by USAID/SALOHI. (USAID; USAID/SALOHI)Published versio
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