664 research outputs found

    SYNDROMIC SURVEILLANCE FOR THE EARLY DETECTION OF INFLUENZA OUTBREAKS

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    Syndromic surveillance is a new mechanism utilized to detect naturally occurring and bioterroristic outbreaks. The public health significance is its potential to alert public health to outbreaks earlier and allow a timelier public health response. It involves monitoring data that can be collected in near real-time to find anomalous data. Syndromic surveillance includes school and work absenteeism, over-the-counter drug sales, and hospital admissions data to name a few. This study is an assessment of an extension of the use of syndromic surveillance as an improvement to the traditional method to detect more routine public health problems, specifically, the detection of influenza outbreaks. The assessment involves the prediction of outbreaks in four areas during the period October 15, 2003 to March 31, 2004. The four areas studied included Allegheny County, Pennsylvania, Jefferson County, Kentucky, Los Angeles County, California, and Salt Lake County, Utah. Two aspects of community activity were used as the method for syndromic surveillance, over-the-counter pharmaceutical sales and hospital chief complaints. The over-the-counter sales encompassed a panel of six items including anti-diarrheal medication, anti-fever adult medication, anti-fever pediatric medication, cough and cold products, electrolytes, and thermometers. Additionally, two of the seven hospital chief complaints used in the RODS open source paradigm were monitored. These were constitutional and respiratory chief complaints. Application of standard statistical algorithms showed that the system was able to identify unusual activity several weeks prior to the time when the local health departments were able to identify an outbreak using the standard methods. The largest improvement in detection using syndromic surveillance occurred in Los Angeles where the outbreak was detected 52 days before the Centers for Disease Control had declared widespread activity for the state. In each county over-the-counter sales detected the outbreak sooner then hospital chief complaints, but the hospital chief complaints detect the outbreaks consistently across the various algorithms. More conclusive evidence regarding the possible improvement in outbreak detection with syndromic surveillance can be obtained once a longer time frame has passed to allow more historical data to accumulate. Conducting additional studies on influenza outbreaks in other jurisdictions would also be useful assessments

    Pistil transcriptome analysis to disclose genes and gene products related to aposporous apomixis in Hypericum perforatum L.

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    Unlike sexual reproduction, apomixis encompasses a number of reproductive strategies,which permit maternal genome inheritance without genetic recombination and syngamy. The key biological features of apomixis are the circumvention of meiosis (i.e., apomeiosis),the differentiation of unreduced embryo sacs and egg cells, and their autonomous development in functional embryos through parthenogenesis, and the formation of viable endosperm either via fertilization-independent means or following fertilization with a sperm cell. Despite the importance of apomixis for breeding of crop plants and although much research has been conducted to study this process, the genetic control of apomixis is still not well understood. Hypericum perforatum is becoming an attractive model system for the study of aposporous apomixis. Here we report results from a global gene expression analysis of H. perforatum pistils collected from sexual and aposporous plant accessions for the purpose of identifying genes, biological processes and molecular functions associated with the aposporous apomixis pathway. Across two developmental stages corresponding to the expression of aposporous apomeiosis and parthenogenesis in ovules, a total of 224 and 973 unigenes were found to be significantly up- and down-regulated with a fold change >= 2 in at least one comparison, respectively.Differentially expressed genes were enriched for multiple gene ontology (GO) terms,including cell cycle, DNA metabolic process, and single-organism cellular process. For molecular functions, the highest scores were recorded for GO terms associated withDNA binding, DNA (cytosine-5-)-methyltransferase activity and heterocyclic compound binding. As deregulation of single components of the sexual developmental pathway is believed to be a trigger of the apomictic reproductive program, all genes involved in sporogenesis, gametogenesis and response to hormonal stimuli were analyzed in great detail. Overall, our data suggest that phenotypic expression of apospory is concomitant with the modulation of key genes involved in the sexual reproductive pathway. Furthermore, based on gene annotation and co-expression, we underline a putative role of hormones and key actors playing in the RNA-directed DNA methylation pathway in regulating the developmental changes occurring during aposporous apomixis in H. perforatum

    Step-By-Step Community Detection in Volume-Regular Graphs

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    Spectral techniques have proved amongst the most effective approaches to graph clustering. However, in general they require explicit computation of the main eigenvectors of a suitable matrix (usually the Laplacian matrix of the graph). Recent work (e.g., Becchetti et al., SODA 2017) suggests that observing the temporal evolution of the power method applied to an initial random vector may, at least in some cases, provide enough information on the space spanned by the first two eigenvectors, so as to allow recovery of a hidden partition without explicit eigenvector computations. While the results of Becchetti et al. apply to perfectly balanced partitions and/or graphs that exhibit very strong forms of regularity, we extend their approach to graphs containing a hidden k partition and characterized by a milder form of volume-regularity. We show that the class of k-volume regular graphs is the largest class of undirected (possibly weighted) graphs whose transition matrix admits k "stepwise" eigenvectors (i.e., vectors that are constant over each set of the hidden partition). To obtain this result, we highlight a connection between volume regularity and lumpability of Markov chains. Moreover, we prove that if the stepwise eigenvectors are those associated to the first k eigenvalues and the gap between the k-th and the (k+1)-th eigenvalues is sufficiently large, the Averaging dynamics of Becchetti et al. recovers the underlying community structure of the graph in logarithmic time, with high probability

    A machine learning approach for detecting cognitive interference based on eye-tracking data

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    The Stroop test evaluates the ability to inhibit cognitive interference. This interference occurs when the processing of one stimulus characteristic affects the simultaneous processing of another attribute of the same stimulus. Eye movements are an indicator of the individual attention load required for inhibiting cognitive interference. We used an eye tracker to collect eye movements data from more than 60 subjects each performing four different but similar tasks (some with cognitive interference and some without). After the extraction of features related to fixations, saccades and gaze trajectory, we trained different Machine Learning models to recognize tasks performed in the different conditions (i.e., with interference, without interference). The models achieved good classification performances when distinguishing between similar tasks performed with or without cognitive interference. This suggests the presence of characterizing patterns common among subjects, which can be captured by machine learning algorithms despite the individual variability of visual behavior

    Biased Opinion Dynamics: When the Devil Is in the Details

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    We investigate opinion dynamics in multi-agent networks when a bias toward one of two possible opinions exists; for example, reflecting a status quo vs a superior alternative. Starting with all agents sharing an initial opinion representing the status quo, the system evolves in steps. In each step, one agent selected uniformly at random adopts the superior opinion with some probability α\alpha, and with probability 1α1 - \alpha it follows an underlying update rule to revise its opinion on the basis of those held by its neighbors. We analyze convergence of the resulting process under two well-known update rules, namely majority and voter. The framework we propose exhibits a rich structure, with a non-obvious interplay between topology and underlying update rule. For example, for the voter rule we show that the speed of convergence bears no significant dependence on the underlying topology, whereas the picture changes completely under the majority rule, where network density negatively affects convergence. We believe that the model we propose is at the same time simple, rich, and modular, affording mathematical characterization of the interplay between bias, underlying opinion dynamics, and social structure in a unified setting.Comment: The paper has appeared in the Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence. The SOLE copyright holder is IJCAI (International Joint Conferences on Artificial Intelligence), all rights reserved. Link to the proceedings: https://www.ijcai.org/Proceedings/2020/

    Una comunità di pratiche: esperienze di pratica riflessiva nella formazione continua di P.I.P.P.I. Programma di Intervento Per la Prevenzione dell’Istituzionalizzazione.

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    P.I.P.P.I. (Programma di Intervento per la Prevenzione dell’Istituzionalizzazione), avviato nel 2011 e riconosciuto come Livello Essenziale di Prestazione Sociale (LEPS) dal 2021, accompagna strategie innovative in risposta ai problemi connessi alla negligenza familiare, coinvolgendo ad oggi 465 Ambiti Territoriali e migliaia tra operatori sociali, educativi e socio- sanitari. In ciascun Ambito sono individuati due operatori con il ruolo di coach, figura chiave che accompagna le innovazioni di P.I.P.P.I. nei territori. L’articolo si sofferma sulla formazione continua di tali figure, svolta con incontri periodici (tutoraggi) in presenza attraverso esperienze di pratica riflessiva e di confronto tra pari e con i ricercatori. L’analisi dei momenti riflessivi del primo tutoraggio della undicesima implementazione evidenzia come il processo riflessivo sia centrale per la trasformazione delle prospettive cognitive e dunque il cambiamento dell’agire

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