739 research outputs found

    Introduction: Youth and Chemicals in a Modernizing Frontier

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    Introduction

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    Introduction

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    Avalanche Breakdown Timing Statistics for Silicon Single Photon Avalanche Diodes

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    CCBY Silicon-based Single Photon Avalanche Diodes (SPADs) are widely used as single photon detectors of visible and near infrared photons. There has however been a lack of models accurately interpreting the physics of impact ionization (the mechanism behind avalanche breakdown) for these devices. In this work, we present a statistical simulation model for silicon SPADs that is capable of predicting breakdown probability, mean time to breakdown and timing jitter. Our model inherently incorporates carriers & #x0027; dead space due to phonon scattering and allows for non-uniform electric fields. Model validation included avalanche gain, excess noise factor, breakdown voltage, breakdown probability, and timing statistics. Simulating an n on-p and a p-on-n SPAD design using our model, we found that the n-on-p design offers significantly improved mean time to breakdown and timing jitter characteristics. For a breakdown probability of 0.5, mean time to breakdown and timing jitter from the n-on-p design were 3 and 4 times smaller compared to those from the p on n design. The data reported in this paper is available from the ORDA digital repository (DOI: 10.15131/shef.data.4823248)

    Sudden unexpected death in epilepsy patients: Risk factors A systematic review

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    SummaryIntroductionSeveral risk factors for sudden unexplained death in epilepsy patients (SUDEP) have been proposed, but subsequent work has yielded conflicting data. The relative importance of various risk factors for SUDEP was never explored. The aim of this study is to review systematically risk factors for SUDEP and also to determine their relevance for SUDEP by calculating relative risk factor ratios.Methods and materialsAuthors performed a literature-search on “SUDEP” in Medline, the Cochrane Library and EMBASE. Studies with unknown number of SUDEP cases or with less than five SUDEP cases and reviews were excluded from further analysis. The value of each paper was assessed, based on the quality of the study and the reliability of the diagnosis of SUDEP. This value ranged from 1 (low quality) to 10 (high quality). Papers with a value below 7 were eliminated for further analysis. For each analysed factor, a risk factor ratio was determined, with a higher ratio for a stronger risk factor.ResultsA number of strong risk factors for SUDEP: young age, early onset of seizures, the presence of generalized tonic clonic seizures, male sex and being in bed. Weak risk factors for SUDEP: prone position, one or more subtherapeutic bloodlevels, being in the bedroom, a strucural brain lesion and sleeping.ConclusionsIn this study, authors have designed a quality scale to select papers. The relative importance of risk factors for SUDEP is demonstrated

    Classification of intellectual disability according to domains of adaptive functioning and between-domains discrepancy in adults with epilepsy

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    Background In the Diagnostic and Statistical Manual of Mental Disorders-Fifth edition (DSM-5), the diagnostic criteria of intellectual disability (ID) include three domains of adaptive deficits: the conceptual, social and practical. Substantial intra-individual differences between domains can be considered an ID domain discrepancy. Method We explored the associations between ID domains, discrepancies and epilepsy in 189 adults (mean age = 47.9; SD = 15.6). Each DSM-5 ID domain was assessed separately, using subscales of the Vineland II for the social and practical domains, and psychological instruments, including intelligence tests, for the conceptual domain. A set of standardised criteria is proposed to identify an ID domain discrepancy. Results An ID domain discrepancy seemed to be present in about one-third of subjects and was particularly present in subjects with moderate ID (53.4%). Impairment in the social domain was most often the reason for the discrepancy. The presence of a discrepancy was significantly related to a focal (localised) epilepsy type (OR = 2.3, P = .028) and a mixed seizure type (OR = 1.4, P = .009). Epilepsy characteristics that are indicative of a more severe and refractory epilepsy, including various seizure types, a high seizure frequency, a combined epilepsy type (both focal and generalised epilepsy) and an early age at onset, were significantly related to more severe impairments in conceptual, social and practical adaptive behaviour (all P values <.01). Conclusions With a substantial proportion of the subjects who had both ID and epilepsy with an ID discrepancy, professionals should be aware of this and take all domains of ID into account when studying or working with this vulnerable population

    Therapeutic capsule endoscopy: Opportunities and challenges

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    10.1260/2040-2295.2.4.459Journal of Healthcare Engineering24459-47

    Phylogenetics of Archerfishes (Toxotidae) and Evolution of the Toxotid Shooting Apparatus

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    A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Archerfishes (Toxotidae) are variously found in the fresh- and brackish-water environments of Asia Pacific and are well known for their ability to shoot water at terrestrial prey. These shots of water are intended to strike their prey and cause it to fall into the water for capture and consumption. While this behavior is well known, there are competing hypotheses (blowpipe vs. pressure tank hypothesis) of how archerfishes shoot and which oral structures are involved. Current understanding of archerfish shooting structures is largely based on two species, Toxotes chatareus and T. jaculatrix. We do not know if all archerfishes possess the same oral structures to shoot water, if anatomical variation is present within these oral structures, or how these features have evolved. Additionally, there is little information on the evolution of the Toxotidae as a whole, with all previous systematic works focusing on the interrelationships of the family. We first investigate the limits of archerfish species using new and previously published genetic data. Our analyses highlight that the current taxonomy of archerfishes does not conform to the relationships we recover. Toxotes mekongensis and T. siamensis are placed in the synonymy of T. chatareus, Toxotes carpentariensis is recognized as a species and removed from the synonymy of T. chatareus, and the genus Protoxotes is recognized for T. lorentzi based on the results of our analyses. We then take an integrative approach, using a combined analysis of discrete hard- and soft-tissue morphological characters with genetic data, to construct a phylogeny of the Toxotidae. Using the resulting phylogenetic hypothesis, we then characterize the evolutionary history and anatomical variation within the archerfishes. We discuss variation in the oral structures and the evolution of the mechanism with respect to the interrelationships of archerfishes, and find that the oral structures of archerfishes support the blowpipe hypothesis but soft-tissue oral structures may also play a role in shooting. Finally, by comparing the morphology of archerfishes to their sister group, we find that the Leptobramidae has relevant shooting features in the oral cavity, suggesting that some components of the archerfish shooting mechanism are examples of co-opted or exapted traits

    Variational approximation for mixtures of linear mixed models

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    Mixtures of linear mixed models (MLMMs) are useful for clustering grouped data and can be estimated by likelihood maximization through the EM algorithm. The conventional approach to determining a suitable number of components is to compare different mixture models using penalized log-likelihood criteria such as BIC.We propose fitting MLMMs with variational methods which can perform parameter estimation and model selection simultaneously. A variational approximation is described where the variational lower bound and parameter updates are in closed form, allowing fast evaluation. A new variational greedy algorithm is developed for model selection and learning of the mixture components. This approach allows an automatic initialization of the algorithm and returns a plausible number of mixture components automatically. In cases of weak identifiability of certain model parameters, we use hierarchical centering to reparametrize the model and show empirically that there is a gain in efficiency by variational algorithms similar to that in MCMC algorithms. Related to this, we prove that the approximate rate of convergence of variational algorithms by Gaussian approximation is equal to that of the corresponding Gibbs sampler which suggests that reparametrizations can lead to improved convergence in variational algorithms as well.Comment: 36 pages, 5 figures, 2 tables, submitted to JCG

    PEMBERDAYAAN EKONOMI KREATIF RUMAH TANGGA MELALUI KREATIVITAS PEMANFAATAN KAUS BEKAS DENGAN TEKNIK TIE DYE

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    Kegiatan pengabdian kepada masyarakat dalam Tridharma Perguruan Tinggi sebaiknya dilakukan mengacu pada kebutuhan masyarakat dan juga memberikan manfaat yang baik sehingga dapat membuka kemungkinan peluang di dalam industri kreatif. Kegiatan tersebut bisa dilakukan dari hasil penelitian dosen, namun dapat juga berdasarkan permintaan khusus berdasarkan keperluan dari masyarakat lingkungan sekitar yang bersangkutan sehingga tepat sasaran dan tepat guna.Metodologi pengabdian ini atas dasar permintaan dari masyarakat di sekitar Universitas Kristen Maranatha melalui kelompok ibu-ibu dan remaja di Pimpinan Cabang Nasyiatul Aisyiyah (PCNA) Sukajadi Bandung. Berdasarkan dari surat permohonan pada Program Studi DIII Seni Rupa dan Desain agar dilakukan pelatihan pengolahan kaus bekas dengan teknik reka tekstil tie dye agar dapat meningkatkan keterampilan, pengetahuan yang cukup untuk bereksplorasi lebih lanjut sehingga didapatkan produk akhir berupa kaus dengan motif tie dye yang berestetika, bahkan memiliki nilai daya jual.Kesempatan melakukan kegiatan ini dinilai sangat positif karena dapat memberikan manfaat bagi kedua belah pihak untuk dapat memberikan kontribusi timbal balik dengan baik. Sehingga keberadaan UK. Maranatha, khususnya kehadiran Prodi DIII SRD dinilai dapat memberikan dampak positif yang dapat dirasakan dan diterima oleh masyarakat sekitar. Kata kunci: bekas, eksperimen, kaus, tekstil, tie dy
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