601 research outputs found

    An open trial assessment of "The Number Race", an adaptive computer game for remediation of dyscalculia

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    BACKGROUND: In a companion article [1], we described the development and evaluation of software designed to remediate dyscalculia. This software is based on the hypothesis that dyscalculia is due to a "core deficit" in number sense or in its access via symbolic information. Here we review the evidence for this hypothesis, and present results from an initial open-trial test of the software in a sample of nine 7–9 year old children with mathematical difficulties. METHODS: Children completed adaptive training on numerical comparison for half an hour a day, four days a week over a period of five-weeks. They were tested before and after intervention on their performance in core numerical tasks: counting, transcoding, base-10 comprehension, enumeration, addition, subtraction, and symbolic and non-symbolic numerical comparison. RESULTS: Children showed specific increases in performance on core number sense tasks. Speed of subitizing and numerical comparison increased by several hundred msec. Subtraction accuracy increased by an average of 23%. Performance on addition and base-10 comprehension tasks did not improve over the period of the study. CONCLUSION: Initial open-trial testing showed promising results, and suggested that the software was successful in increasing number sense over the short period of the study. However these results need to be followed up with larger, controlled studies. The issues of transfer to higher-level tasks, and of the best developmental time window for intervention also need to be addressed

    4-Ï€-Photocyclization of 1,2-Dihydropyridazines: An Approach to Bicyclic 1,2-Diazetidines with Rich Synthetic Potential.

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    The 4-Ï€-photocyclization of a range of 1,2-dihydropyridazines is described, generating bicyclic 1,2-diazetidines in high yields on multigram scale. The key bicyclic 1,2-diazetidines are versatile synthetic intermediates and were easily converted into a range of novel derivatives, including functionalized 1,2-diazetidines, cyclobutenes, cyclobutanes, and 1,3-dienes

    Understanding the welfare requirements of a neurologically and physically divergent captive male Sumatran orangutan (Pongo abelii)

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    BackgroundUnderstanding the needs of animals with physical and cognitive impairments is essential for zoos, rehabilitation centres, and other captive contexts. This case study describes the atypical physical and cognitive development of Jiwa, an adult male Sumatran orangutan (Pongo abelii), to evaluate how these differences may impact Jiwa and to explore how cognitive enrichment can be tailored to his skill level.MethodsKeeper records from Jiwa’s birth (1999) to February 2022 were scrutinised to identify key developmental milestones, changes in body weight, and deciduous dental emergence. These were compared with expected milestones for wild and captive orangutans. In addition, a probe feeder apparatus was gradually tailored to an appropriate skill level between January and March 2022.ResultsMany of Jiwa’s developmental milestones were consistent with expected orangutan development, although there were noticeable differences in body weight, dental emergence, locomotion, and cognition. The welfare domains most likely to be negatively impacted by these differences were physical health, expression of agency, and mental wellbeing. After the enrichment device was tailored to an appropriate level of challenge, Jiwa showed marked improvement in engagement and ability to use the device.ConclusionsThis study helps to inform future case studies of atypical great apes by detailing the physical and cognitive development of an individual orangutan. Although Jiwa’s differences may impact his own wellbeing in some areas, he has largely been able to overcome them. However, this case study highlights the challenges involved in tailoring enrichment apparatuses and resilience interventions for atypical individuals

    Human Disturbance Influences Reproductive Success and Growth Rate in California Sea Lions (Zalophus californianus)

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    The environment is currently undergoing changes at both global (e.g., climate change) and local (e.g., tourism, pollution, habitat modification) scales that have the capacity to affect the viability of animal and plant populations. Many of these changes, such as human disturbance, have an anthropogenic origin and therefore may be mitigated by management action. To do so requires an understanding of the impact of human activities and changing environmental conditions on population dynamics. We investigated the influence of human activity on important life history parameters (reproductive rate, and body condition, and growth rate of neonate pups) for California sea lions (Zalophus californianus) in the Gulf of California, Mexico. Increased human presence was associated with lower reproductive rates, which translated into reduced long-term population growth rates and suggested that human activities are a disturbance that could lead to population declines. We also observed higher body growth rates in pups with increased exposure to humans. Increased growth rates in pups may reflect a density dependent response to declining reproductive rates (e.g., decreased competition for resources). Our results highlight the potentially complex changes in life history parameters that may result from human disturbance, and their implication for population dynamics. We recommend careful monitoring of human activities in the Gulf of California and emphasize the importance of management strategies that explicitly consider the potential impact of human activities such as ecotourism on vertebrate populations

    Niche differentiation is spatially and temporally regulated in the rhizosphere.

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    The rhizosphere is a hotspot for microbial carbon transformations, and is the entry point for root polysaccharides and polymeric carbohydrates that are important precursors to soil organic matter (SOM). However, the ecological mechanisms that underpin rhizosphere carbohydrate depolymerization are poorly understood. Using Avena fatua, a common annual grass, we analyzed time-resolved metatranscriptomes to compare microbial functions in rhizosphere, detritusphere, and combined rhizosphere-detritusphere habitats. Transcripts were binned using a unique reference database generated from soil isolate genomes, single-cell amplified genomes, metagenomes, and stable isotope probing metagenomes. While soil habitat significantly affected both community composition and overall gene expression, the succession of microbial functions occurred at a faster time scale than compositional changes. Using hierarchical clustering of upregulated decomposition genes, we identified four distinct microbial guilds populated by taxa whose functional succession patterns suggest specialization for substrates provided by fresh growing roots, decaying root detritus, the combination of live and decaying root biomass, or aging root material. Carbohydrate depolymerization genes were consistently upregulated in the rhizosphere, and both taxonomic and functional diversity were highest in the combined rhizosphere-detritusphere, suggesting coexistence of rhizosphere guilds is facilitated by niche differentiation. Metatranscriptome-defined guilds provide a framework to model rhizosphere succession and its consequences for soil carbon cycling

    Microbial dark matter ecogenomics reveals complex synergistic networks in a methanogenic bioreactor

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    Ecogenomic investigation of a methanogenic bioreactor degrading terephthalate (TA) allowed elucidation of complex synergistic networks of uncultivated microorganisms, including those from candidate phyla with no cultivated representatives. Our previous metagenomic investigation proposed that Pelotomaculum and methanogens may interact with uncultivated organisms to degrade TA; however, many members of the community remained unaddressed because of past technological limitations. In further pursuit, this study employed state-of-the-art omics tools to generate draft genomes and transcriptomes for uncultivated organisms spanning 15 phyla and reports the first genomic insight into candidate phyla Atribacteria, Hydrogenedentes and Marinimicrobia in methanogenic environments. Metabolic reconstruction revealed that these organisms perform fermentative, syntrophic and acetogenic catabolism facilitated by energy conservation revolving around H2 metabolism. Several of these organisms could degrade TA catabolism by-products (acetate, butyrate and H2) and syntrophically support Pelotomaculum. Other taxa could scavenge anabolic products (protein and lipids) presumably derived from detrital biomass produced by the TA-degrading community. The protein scavengers expressed complementary metabolic pathways indicating syntrophic and fermentative step-wise protein degradation through amino acids, branched-chain fatty acids and propionate. Thus, the uncultivated organisms may interact to form an intricate syntrophy-supported food web with Pelotomaculum and methanogens to metabolize catabolic by-products and detritus, whereby facilitating holistic TA mineralization to CO2 and CH4

    Defining the clinical role of adapted digital light field photography in the treatment of HIV-induced Kaposi\u27s sarcoma lesions

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    Kaposi’s sarcoma (KS): a vascular tumor associated with HHV8 and HIV infection KS burden at Maputo Central Hospital (MCH): •Referral center for all of southern Mozambique, 1500 beds, \u3e65% HIV+ patients on medical services •Dermatology ward: 50 beds, \u3e30% of admitted patients suffer from Kaposi’s sarcoma and its complications •10-15 cases/month admitted with advanced KS; additional 15-20 cases/month treated outpatient •KS is the most common form of malignancy seen at MCH among men, second most frequent among women Current KS standard of care: •First line treatment: chemo- and concomitant antiretroviral-therapy •Pre-treatment photographs rarely taken to establish a baseline for therapeutic monitoring •Post-therapy improvement is based on gross examination and clinical judgment •Tracking correlation between therapy dosing and shrinkage of lesion size is difficult due to variation and number of lesions Aim of the study: determine the utility of adapted digital light field photography in a resource-limited setting and establish best clinical practice for future KS monitoring via photograph

    Traumatic brain injury causes selective, CD74-dependent peripheral lymphocyte activation that exacerbates neurodegeneration

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    INTRODUCTION: Traumatic brain injury (TBI), a significant cause of death and disability, causes, as in any injury, an acute, innate immune response. A key component in the transition between innate and adaptive immunity is the processing and presentation of antigen by professional antigen presenting cells (APCs). Whether an adaptive immune response to brain injury is beneficial or detrimental is not known. Current efforts to understand the contribution of the immune system after TBI have focused on neuroinflammation and brain-infiltrating immune cells. Here, we characterize and target TBI-induced expansion of peripheral immune cells that may act as potential APCs. Because MHC Class II-associated invariant peptide (CLIP) is important for antigen processing and presentation, we engineered a competitive antagonist (CAP) for CLIP, and tested the hypothesis that peptide competition could reverse or prevent neurodegeneration after TBI. RESULTS: We show that after fluid percussion injury (FPI), peripheral splenic lymphocytes, including CD4+ and CD8+ T cells, regulatory T cells (Tregs), and γδ T cells, are increased in number within 24 hours after FPI. These increases were reversed by CAP treatment and this antagonism of CLIP also reduced neuroinflammation and neurodegeneration after TBI. Using a mouse deficient for the precursor of CLIP, CD74, we observed decreased peripheral lymphocyte activation, decreased neurodegeneration, and a significantly smaller lesion size following TBI. CONCLUSION: Taken together, the data support the hypothesis that neurodegeneration following TBI is dependent upon antigen processing and presentation that requires CD74. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40478-014-0143-5) contains supplementary material, which is available to authorized users

    The Cutaneous Microbiome and Wounds: New Molecular Targets to Promote Wound Healing

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    The ecological community of microorganisms in/on humans, termed the microbiome, is vital for sustaining homeostasis. While culture-independent techniques have revealed the role of the gut microbiome in human health and disease, the role of the cutaneous microbiome in wound healing is less defined. Skin commensals are essential in the maintenance of the epithelial barrier function, regulation of the host immune system, and protection from invading pathogenic microorganisms. In this review, we summarize the literature derived from pre-clinical and clinical studies on how changes in the microbiome of various acute and chronic skin wounds impact wound healing tissue regeneration. Furthermore, we review the mechanistic insights garnered from model wound healing systems. Finally, in the face of growing concern about antibiotic-resistance, we will discuss alternative strategies for the treatment of infected wounds to improve wound healing and outcomes. Taken together, it has become apparent that commensals, symbionts, and pathogens on human skin have an intimate role in the inflammatory response that highlights several potential strategies to treat infected, non-healing wounds. Despite these promising results, there are some contradictory and controversial findings from existing studies and more research is needed to define the role of the human skin microbiome in acute and chronic wound healing
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