Learning Character-level Compositionality with Visual Features

Previous work has modeled the compositionality of words by creating character-level models of meaning, reducing problems of sparsity for rare words. However, in many writing systems compositionality has an effect even on the character-level: the meaning of a character is derived by the sum of its parts. In this paper, we model this effect by creating embeddings for characters based on their visual characteristics, creating an image for the character and running it through a convolutional neural network to produce a visual character embedding. Experiments on a text classification task demonstrate that such model allows for better processing of instances with rare characters in languages such as Chinese, Japanese, and Korean. Additionally, qualitative analyses demonstrate that our proposed model learns to focus on the parts of characters that carry semantic content, resulting in embeddings that are coherent in visual space.Comment: Accepted to ACL 201

Extraction of Airways with Probabilistic State-space Models and Bayesian Smoothing

Segmenting tree structures is common in several image processing applications. In medical image analysis, reliable segmentations of airways, vessels, neurons and other tree structures can enable important clinical applications. We present a framework for tracking tree structures comprising of elongated branches using probabilistic state-space models and Bayesian smoothing. Unlike most existing methods that proceed with sequential tracking of branches, we present an exploratory method, that is less sensitive to local anomalies in the data due to acquisition noise and/or interfering structures. The evolution of individual branches is modelled using a process model and the observed data is incorporated into the update step of the Bayesian smoother using a measurement model that is based on a multi-scale blob detector. Bayesian smoothing is performed using the RTS (Rauch-Tung-Striebel) smoother, which provides Gaussian density estimates of branch states at each tracking step. We select likely branch seed points automatically based on the response of the blob detection and track from all such seed points using the RTS smoother. We use covariance of the marginal posterior density estimated for each branch to discriminate false positive and true positive branches. The method is evaluated on 3D chest CT scans to track airways. We show that the presented method results in additional branches compared to a baseline method based on region growing on probability images.Comment: 10 pages. Pre-print of the paper accepted at Workshop on Graphs in Biomedical Image Analysis. MICCAI 2017. Quebec Cit

Glucose deprivation activates a metabolic and signaling amplification loop leading to cell death.

The altered metabolism of cancer can render cells dependent on the availability of metabolic substrates for viability. Investigating the signaling mechanisms underlying cell death in cells dependent upon glucose for survival, we demonstrate that glucose withdrawal rapidly induces supra-physiological levels of phospho-tyrosine signaling, even in cells expressing constitutively active tyrosine kinases. Using unbiased mass spectrometry-based phospho-proteomics, we show that glucose withdrawal initiates a unique signature of phospho-tyrosine activation that is associated with focal adhesions. Building upon this observation, we demonstrate that glucose withdrawal activates a positive feedback loop involving generation of reactive oxygen species (ROS) by NADPH oxidase and mitochondria, inhibition of protein tyrosine phosphatases by oxidation, and increased tyrosine kinase signaling. In cells dependent on glucose for survival, glucose withdrawal-induced ROS generation and tyrosine kinase signaling synergize to amplify ROS levels, ultimately resulting in ROS-mediated cell death. Taken together, these findings illustrate the systems-level cross-talk between metabolism and signaling in the maintenance of cancer cell homeostasis

Contributos do Ensino - Aprendizagem do Inglês, nos 3º e 4º anos do Ensino Básico, para os resultados obtidos pelos alunos na disciplina de Inglês, no 5º ano do Ensino Básico, no distrito de Évora.

O presente artigo dá conta da investigação que verificou a relação entre a frequência da Atividade de Enriquecimento Curricular (AEC) de Inglês, pelos alunos dos 3º e 4º anos do Ensino Básico, dos agrupamentos de escolas do distrito de Évora, no biénio 2005-2007 e os resultados obtidos, pelos mesmos, no final do ano letivo 2007/2008, na disciplina de Inglês, no 5º ano do Ensino Básico, nos agrupamentos de escolas do distrito de Évora que frequentaram. Dá, ainda, conta das relações entre esses resultados, a assiduidade, as retenções, o desenvolvimento cognitivo e o género desses mesmos alunos, nos resultados observados no referido 5ºAno

Heterologously-expressed and Liposome-reconstituted Human Transient Receptor Potential Melastatin 4 Channel (TRPM4) is a Functional Tetramer

Mutation, irregular expression and sustained activation of the Transient Receptor Potential Channel, type Melastatin 4 (TRPM4), have been linked to various cardiovascular diseases. However, much remains unknown about the structure of this important ion channel. Here, we have purified a heterologously expressed TRPM4-eGFP fusion protein and investigated the oligomeric state of TRPM4-eGFP in detergent micelles using crosslinking, native gel electrophoresis, multi-angle laser light scattering and electron microscopy. Our data indicate that TRPM4 is tetrameric, like other TRP channels studied to date. Furthermore, the functionality of liposome reconstituted TRPM4-eGFP was examined using electrophysiology. Single-channel recordings from TRPM4-eGFP proteoliposomes showed inhibition of the channel using Flufenamic acid, a well-established inhibitor of TRPM4, suggesting that the channels are functional upon reconstitution. Our characterisation of the oligomeric structure of TRPM4 and the ability to reconstitute functional channels in liposomes should facilitate future studies into the structure, function and pharmacology of this therapeutically relevant channel

Questionnaire tools for the diagnosis of carpal tunnel syndrome from the patient history

Introduction: There remains no “gold standard” for the diagnosis of carpal tunnel syndrome (CTS). Clinical diagnosis is often held to be paramount but depends on the skills of the individual practitioner. We describe two mathematical approaches to the analysis of a history obtained by questionnaire. Methods: We used two earlier instruments, a conventional logistic regression analysis, and an artificial neural network to analyze data from 5860 patients referred for diagnosis of hand symptoms. We evaluated their ability to predict whether nerve conduction studies would show evidence of CTS using receiver operating characteristic curves. Results: Both new instruments outperformed the existing tools, achieving sensitivity of 88% and specificity of 50% in predicting abnormal median nerve conduction. When combined, 96% sensitivity and 50% specificity were achieved. Conclusion: The combined instrument can be used as a preliminary screening tool for CTS, for self-diagnosis, and as a supplement to diagnosis in primary care

Motivational trajectories for early language learning across the primary-secondary school transition

The transition from primary to secondary school is an area of concern across a range of curriculum subjects, and this is no less so for foreign language learning. Indeed problems with transition have been identified in England as an important barrier to the introduction of language learning to the primary school curriculum, with implications for learners’ longer-term motivation for the subject. This longitudinal study investigated, through a questionnaire, the development of 233 learners’ motivation for learning French in England, during the transition from primary to secondary schooling. It also explored whether levels and patterns of motivation differed according to the type of language teaching experienced, comparing a largely oracy-focused approach with one with greater emphasis on literacy activities. Learners showed high and increasing levels of motivation across transition, placing particular value on learning French for travel. Being taught through an oracy or a literacy-focused approach had less impact on learners’ motivation than broader classroom experiences, with the development of a sense of progress and feeling that instruction met their learning needs being especially important. A growing disjuncture emerged between valuing the learning of French for travel/communication and learners’ low levels of self-efficacy for communication with native speakers, together with a desire for more communication-based activities. By the end of the first year of secondary school less positive attitudes towards learning French and less optimism about the possibility of future progress were beginning to emerge. The paper concludes by outlining the implications of the study for classroom practice in language learning

TAM receptor tyrosine kinase function and the immunopathology of liver disease.

Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology

IKK phosphorylates Huntingtin and targets it for degradation by the proteasome and lysosome

Expansion of the polyglutamine repeat within the protein Huntingtin (Htt) causes Huntington's disease, a neurodegenerative disease associated with aging and the accumulation of mutant Htt in diseased neurons. Understanding the mechanisms that influence Htt cellular degradation may target treatments designed to activate mutant Htt clearance pathways. We find that Htt is phosphorylated by the inflammatory kinase IKK, enhancing its normal clearance by the proteasome and lysosome. Phosphorylation of Htt regulates additional post-translational modifications, including Htt ubiquitination, SUMOylation, and acetylation, and increases Htt nuclear localization, cleavage, and clearance mediated by lysosomal-associated membrane protein 2A and Hsc70. We propose that IKK activates mutant Htt clearance until an age-related loss of proteasome/lysosome function promotes accumulation of toxic post-translationally modified mutant Htt. Thus, IKK activation may modulate mutant Htt neurotoxicity depending on the cell's ability to degrade the modified species