Learning to Estimate Search Progress Using Sequence of States

Many problems of interest can be solved using heuristic search algorithms. When solving a heuristic search problem, we are often interested in estimating search progress, that is, how much longer until we have a solution. Previous work on search progress estimation derived formulas based on some relevant features that can be observed from the behavior of the search algorithm. In this paper, rather than manually deriving such formulas we leverage machine learning to learn more accurate search progress predictors automatically. We train a Long Short-Term Memory (LSTM) network, which takes as input sequences of nodes expanded by the search algorithm, and predicts how far along with the search we are. Importantly, our approach still treats the search algorithm as a black box and does not look into the contents of search nodes. An empirical evaluation shows our technique outperforms previous search progress estimation techniques

Stucture et conditions de dépôt des calcaires canbriens de Basse-Normandie

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Structure et conditions de dépôt des calcaires cambriens de Basse-Normandie. In : Compte-rendu du Congrès des Sociétés savantes en 1912, Sciences

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Fcγ Receptor-Mediated Suppression of Human Immunodeficiency Virus Type 1 Replication in Primary Human Macrophages

Permissiveness of monocytes and macrophages to human immunodeficiency virus (HIV) infection is modulated by various stimuli. In this study we demonstrate that stimulation of primary monocytes and monocyte-derived macrophages (MDM) through the receptors for the Fc portion of immunoglobulin G (IgG) (FcγR) inhibits HIV type 1 (HIV-1) replication. Viral p24 production was decreased by 1.5 to 3 log units in MDM infected with both R5 and X4 HIV-1 strains upon stimulation by immobilized IgG but not upon stimulation by soluble IgG or by F(ab′)(2) IgG fragments. Although MDM activation by immobilized IgG induced high levels of macrophage-derived chemokine secretion as well as a sustained down-regulation of CD4 and a transient decrease in CCR5 expression, these factors did not appear to play a major role in the suppression of HIV-1 replication. Single-cycle infection of FcγR-stimulated MDM with HIV-1 virions pseudotyped with either HIV-1 R5 or vesicular stomatitis virus G envelopes was inhibited, suggesting a postentry restriction of viral replication. PCR analyses of HIV-1 DNA intermediate replication forms suggested that reverse transcription is not affected by stimulation with immobilized human IgG, at least during the first replication cycle. The accumulation of PCR products corresponding to nuclear unintegrated two-long-terminal-repeat circles and the relative decrease of integrated HIV-1 DNA signals suggest an inhibition of proviral integration. Our data, showing that FcγR-mediated activation of MDM is a potent mechanism of HIV-1 suppression, raise the possibility that FcγR cross-linking by immune complexes may contribute to the control of viral replication in macrophages

A Developmental Surveillance Score for Quantitative Monitoring of Early Childhood Milestone Attainment: Algorithm Development and Validation

BackgroundDevelopmental surveillance, conducted routinely worldwide, is fundamental for timely identification of children at risk of developmental delays. It is typically executed by assessing age-appropriate milestone attainment and applying clinical judgment during health supervision visits. Unlike developmental screening and evaluation tools, surveillance typically lacks standardized quantitative measures, and consequently, its interpretation is often qualitative and subjective. ObjectiveHerein, we suggested a novel method for aggregating developmental surveillance assessments into a single score that coherently depicts and monitors child development. We described the procedure for calculating the score and demonstrated its ability to effectively capture known population-level associations. Additionally, we showed that the score can be used to describe longitudinal patterns of development that may facilitate tracking and classifying developmental trajectories of children. MethodsWe described the Developmental Surveillance Score (DSS), a simple-to-use tool that quantifies the age-dependent severity level of a failure at attaining developmental milestones based on the recently introduced Israeli developmental surveillance program. We evaluated the DSS using a nationwide cohort of >1 million Israeli children from birth to 36 months of age, assessed between July 1, 2014, and September 1, 2021. We measured the score’s ability to capture known associations between developmental delays and characteristics of the mother and child. Additionally, we computed series of the DSS in consecutive visits to describe a child’s longitudinal development and applied cluster analysis to identify distinct patterns of these developmental trajectories. ResultsThe analyzed cohort included 1,130,005 children. The evaluation of the DSS on subpopulations of the cohort, stratified by known risk factors of developmental delays, revealed expected relations between developmental delay and characteristics of the child and mother, including demographics and obstetrics-related variables. On average, the score was worse for preterm children compared to full-term children and for male children compared to female children, and it was correspondingly worse for lower levels of maternal education. The trajectories of scores in 6 consecutive visits were available for 294,000 children. The clustering of these trajectories revealed 3 main types of developmental patterns that are consistent with clinical experience: children who successfully attain milestones, children who initially tend to fail but improve over time, and children whose failures tend to increase over time. ConclusionsThe suggested score is straightforward to compute in its basic form and can be easily implemented as a web-based tool in its more elaborate form. It highlights known and novel relations between developmental delay and characteristics of the mother and child, demonstrating its potential usefulness for surveillance and research. Additionally, it can monitor the developmental trajectory of a child and characterize it. Future work is needed to calibrate the score vis-a-vis other screening tools, validate it worldwide, and integrate it into the clinical workflow of developmental surveillance