678 research outputs found

    Novel architecture for human re-identification with a two-stream neural network and attention ,echanism

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    This paper proposes a novel architecture that utilises an attention mechanism in conjunction with multi-stream convolutional neural networks (CNN) to obtain high accuracy in human re-identification (Reid). The proposed architecture consists of four blocks. First, the pre-processing block prepares the input data and feeds it into a spatial-temporal two-stream CNN (STC) with two fusion points that extract the spatial-temporal features. Next, the spatial-temporal attentional LSTM block (STA) automatically fine-tunes the extracted features and assigns weight to the more critical frames in the video sequence by using an attention mechanism. Extensive experiments on four of the most popular datasets support our architecture. Finally, the results are compared with the state of the art, which shows the superiority of this approach

    Phasmid-like structures in Anguinidae (Nematoda, Tylenchida)

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    Des observations en microscopie électronique à balayage et en microscopie optique ont révélé la présence de structures analogues à des phasmides chez #Ditylenchus dipsaci, #D. destructor, #D. triformis, #D. convallariae, #Anguina tritici, #A. agropyri, #Heteroanguina graminophila, #Mesoanguina millefolii, #M. plantaginis et #Subanguina radicicola. Ces structures sont localisées dorsalement par rapport aux champs latéraux, dans la région postmédiane du corps. Par ce caractère, les #Anguinidae sont proches des familles placées dans les #Tylenchoidea dans la classification proposée par Siddiqi (1986); leur placement chez les #Hexatylina apparaît inexact. La présence de phasmides dans la région caudale chez #Psilenchus, #Atetylenchus et #Antarctenchus soutient l'idée d'exclure ces genres de la famille des #Tylenchidae$ telle que définie dans la classification proposée par Maggenti et al. (1988). (Résumé d'auteur

    Melting of persistent double-stranded polymers

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    Motivated by recent DNA-pulling experiments, we revisit the Poland-Scheraga model of melting a double-stranded polymer. We include distinct bending rigidities for both the double-stranded segments, and the single-stranded segments forming a bubble. There is also bending stiffness at the branch points between the two segment types. The transfer matrix technique for single persistent chains is generalized to describe the branching bubbles. Properties of spherical harmonics are then exploited in truncating and numerically solving the resulting transfer matrix. This allows efficient computation of phase diagrams and force-extension curves (isotherms). While the main focus is on exposition of the transfer matrix technique, we provide general arguments for a reentrant melting transition in stiff double strands. Our theoretical approach can also be extended to study polymers with bubbles of any number of strands, with potential applications to molecules such as collagen.Comment: 9 pages, 7 figure

    Speculative securities

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    A speculative security is an asset whose payoff depends on a random shock uncorrelated with economic fundamentals (a sunspot) about which some traders have superior information. In this paper we show that agents may find it desirable to trade such a security in spite of the fact that it is a poorer hedge against their endowment risks as the time of trade, and has an associated adverse selection cost. In the specific institutional setting of innovation of futures contracts, we show that a futures exchange may not have an incentive to introduce a speculative security even when all traders favor it.Information revelation, sunspots, security design, futures contract, trading volume

    Study of Optimal Perimetric Testing In Children (OPTIC): Normative visual field values in children

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    Purpose: We sought to define normative visual field (VF) values for children using common clinical test protocols for kinetic and static perimetry. Design: Prospective, observational study. Subjects: We recruited 154 children aged 5 to 15 years without any ophthalmic condition that would affect the VF (controls) from pediatric clinics at Moorfields Eye Hospital. Methods: Children performed perimetric assessments in a randomized order using Goldmann and Octopus kinetic perimetry, and Humphrey static perimetry (Swedish Interactive Thresholding Algorithm [SITA] 24-2 FAST), in a single sitting, using standardized clinical protocols, with assessment by a single examiner. Unreliable results (assessed qualitatively) were excluded from the normative data analysis. Linear, piecewise, and quantile mixed-effects regression models were used. We developed a method to display age-specific normative isopters graphically on a VF plot to aid interpretation. Main Outcome Measures: Summary measures and graphical plots describing normative VF data for 3 common perimetric tests. Results: Visual field area increased with age on testing with Goldmann isopters III4e, I4e, and I2e (linear regression; P < 0.001) and for Octopus isopters III4e and I4e (linear regression; P < 0.005). Visual field development occurs predominately in the infero-temporal field. Humphrey mean deviation (MD) showed an increase of 0.3 decibels (dB; 95% CI, 0.21-0.40) MD per year up to 12 years of age, when adult MD values were reached and thereafter maintained. Conclusions: Visual field size and sensitivity increase with age in patterns that are specific to the perimetric approach used. These developmental changes should be accounted for when interpreting perimetric test results in children, particularly when monitoring change over time

    Is amblyopia associated with school readiness and cognitive performance during early schooling? Findings from the Millennium Cohort Study

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    Background: Amblyopia is a neurodevelopmental condition causing reduced vision, for which programmes of whole population child vision screening exist throughout the world. There is an ongoing debate about the value of screening due to the lack of evidence about meaningful functional impacts of amblyopia. Our objective was to determine whether amblyopia is associated with school readiness and early cognitive performance. / Methods and findings: Data from the prospective Millennium Cohort Study of children born in the United Kingdom in 2000–01 and followed-up to age 7 years (n = 13,967). Using parental self-report on eye conditions and treatment coded by clinical reviewers, participants were grouped into no eye conditions, strabismus alone, refractive amblyopia, or strabismic/mixed (refractive plus strabismic) amblyopia. The outcomes were poor school readiness using Bracken School Readiness Assessment 10 points) irrespective of whether treatment had already started. The age-related cognitive trajectories of children with amblyopia did not differ from those without any eye conditions for either NV (p = 0.62) or PC (p = 0.51). These associations are at population rather than individual level, so it might be that some individuals with amblyopia did experience significant adverse outcomes that are not captured by summary statistics. / Conclusions: Amblyopia is not significantly associated with adverse cognitive performance and trajectories in early schooling and there is no evidence that this is due to a mediating effect of treatment. Although amblyopia combined with strabismus is associated with poor school readiness, this is not translated into poor cognitive performance. These novel findings may explain the lack of association reported between amblyopia and educational outcomes in adult life and suggest that the impact of amblyopia on education is not of itself a justification for whole population child vision screening aimed at detecting this disorder

    Does having amblyopia affect school readiness and cognitive performance?

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    Background: Amblyopia is a neurodevelopmental condition causing reduced vision, for which international programmes of whole population child vision screening exist. There is an ongoing debate about the value of screening due to the lack of evidence about meaningful functional impacts of amblyopia and the extent to which these can be mitigated by treatment. / Objective(s): To determine whether amblyopia is associated with school readiness and early cognitive performance. / Method(s): Data from the prospective Millennium Cohort Study of children born in the United Kingdom in 2000-01 and followed-up to age 7 years (n=13,967). Using parental self-report on eye conditions and treatment coded by clinical reviewers, participants were grouped into no eye conditions, strabismus alone, refractive amblyopia, or strabismic/mixed (refractive plus strabismic) amblyopia. The outcomes were poor school readiness using Bracken School Readiness Assessment 10 points) compared to those without any eye conditions, irrespective of whether the treatment had already started. The age-related cognitive trajectories of children with amblyopia did not differ from those without any eye conditions for Naming Vocabulary (p=0.62) and Pattern Construction (p=0.51). / Conclusions: Amblyopia does not appear to affect cognitive performance and trajectories in early schooling and there is no evidence that this is due to a mediating effect of treatment. Although amblyopia combined with strabismus is associated with poor school readiness, this is not translated to poor cognitive performance. These novel findings may explain the lack of associations between amblyopia and educational outcomes in adult life and suggest that the impact of amblyopia on education may not of itself be a justification for population screening aimed at detecting this disorder

    The Combined Impact Of IgLON Family Proteins Lsamp And Neurotrimin On Developing Neurons And Behavioral Profiles In Mouse

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    Cell surface neural adhesion proteins are critical components in the complex orchestration of cell proliferation, apoptosis, and neuritogenesis essential for proper brain construction and behavior. We focused on the impact of two plasticity-associated IgLON family neural adhesion molecules, Neurotrimin (Ntm) and Limbic system associated membrane protein (Lsamp), on mouse behavior and its underlying neural development. Phenotyping neurons derived from the hippocampi of Lsamp−/−, Ntm−/− and Lsamp−/−Ntm−/− mice was performed in parallel with behavioral testing. While the anatomy of mutant brains revealed no gross changes, the Ntm−/− hippocampal neurons exhibited premature sprouting of neurites and manifested accelerated neurite elongation and branching. We propose that Ntm exerts an inhibitory impact on neurite outgrowth, whereas Lsamp appears to be an enhancer of the said process as premature neuritogenesis in Ntm−/− neurons is apparent only in the presence of Lsamp. We also show interplay between Lsamp and Ntm in regulating tissue homeostasis: the impact of Ntm on cellular proliferation was dependent on Lsamp, and Lsamp appeared to be a positive regulator of apoptosis in the presence of Ntm. Behavioral phenotyping indicated test-specific interactions between Lsamp and Ntm. The phenotypes of single mutant lines, such as reduced swimming speed in Morris water maze and increased activity in the elevated plus maze, were magnified in Lsamp−/−Ntm−/− mice. Altogether, evidence both from behavioral experiments and cultured hippocampal cells show combined and differential interactions between Ntm and Lsamp in the formation of hippocampal circuits and behavioral profiles. We demonstrate that mutual interactions between IgLON molecules regulate the initiation of neurite sprouting at very early ages, and even cell-autonomously, independent of their regulation of cell-cell adhesion

    Educational attainment and trajectories at key stages of schooling for children with amblyopia compared to those without eye conditions: Findings from the Millennium Cohort Study

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    Background Amblyopia is a neurodevelopmental condition resulting in reduced vision for which whole population child vision screening is undertaken. Cross-sectional studies have established an association between amblyopia and lower academic self-concept, slower reading speed. No difference has been found in educational performance in adolescence whilst there are mixed associations with educational attainment in adults. Educational trajectories and intentions have not been studied previously. We analyse if those treated for amblyopia have different educational performance and trajectories for core subjects during statutory schooling, or subsequent higher education (university) intentions than their peers without eye conditions. Methods and findings Data from the Millennium Cohort Study of children born in the United Kingdom in 2000-01 and followed-up to age 17 years (n = 9989). Using a validated approach drawing on parental self-report on eye conditions and treatment coded by clinical reviewers, participants were grouped into mutually exclusive categories: no eye conditions, strabismus alone, refractive amblyopia, strabismic/mixed (refractive plus strabismic) amblyopia. The outcomes were levels and trajectories of passing English, Maths, Science at ages 7-16 years, passing national exams at age 16, and intentions at ages 14-17 to pursue higher (university) education. Adjusted analyses showed that amblyopia status was not associated with performance in English, Maths, and Science at any key stage, attainment in national exams, or intending to go to university. Similarly, the age-related trajectories of performance in core subjects and higher education intentions did not differ between the groups. There were no significant differences in main reason for having or not having university intentions. Conclusions We found no associations between a history of amblyopia and either adverse performance or age-related attainment trajectories in core subjects during key stages of statutory schooling as well as the absence of an association with intentions for higher education. These results should be reassuring to affected children and young people, and their families, teachers and physicians

    Effect of delayed icing on the quality of tiger shrimp (Penaeus monodon Fab.)

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    Effect of delayed icing on the quality of Penaeus monodon iced after three hours of harvest was studied in plastic and bamboo baskets. After harvest of three hours at ambient temperature (28°-32°C), ice was added to the shrimp at a ratio of 1:1 (shrimp:ice) and stored for 21 hours in both the baskets. Quality evaluation was carried out through visual assessment, biochemical analysis and microbial analysis for 24 hours. The organoleptic evaluation and scoring was done from the time of harvest treated as 0 hour and the average score was 10. At 9th hour after iced condition quality of shrimp was found reduced to the next stage (acceptable) with a score ranged from 8.4-6.5 in both baskets. This acceptable stage was observed throughout the experiment for bamboo basket whereas in the plastic basket the quality was reduced to a small extent with a score of 6.4 (moderately acceptable). Till the end point of the experiment the quality of shrimp was acceptable in respect to biochemical analysis. The microbial load was found log sub(10) 3.99±0.12 cfu/g to log sub(10) 4.33±0.21 cfu/g and log sub(10) 4.01 ±0.12 cfu/g to log sub(10) 4.83±0.19 cfu/g in the bamboo and plastic basket respectively. The importers or buyers suggests for immediate icing to maintain good quality but results of the present experiment suggest that the quality does not vary drastically for first three hours
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