Plague, a reemerging disease in Madagascar.

Human cases of plague, which had virtually disappeared in Madagascar after the 1930s, reappeared in 1990 with more than 200 confirmed or presumptive cases reported each year since. In the port of Mahajanga, plague has been reintroduced, and epidemics occur every year. In Antananarivo, the capital, the number of new cases has increased, and many rodents are infected with Yersinia pestis. Despite surveillance for the sensitivity of Y. pestis and fleas to drugs and insecticides and control measures to prevent the spread of sporadic cases, the elimination of plague has been difficult because the host and reservoir of the bacillus, Rattus rattus, is both a domestic and a sylvatic rat

Eye Movements and Word Recognition during Visual Semantic Search: Diferences between Expert and Novice Language Learners

Background. Te empirical studies in visual word recognition done over the past years have been focused on the infuence of contextual, lexical, and semantic properties. Researchers also have taken into consideration the role of individual diferences in the word recognition process, e.g., vocabulary knowledge. Objective. Tis study focuses on the cognitive strategies used by expert and novice language learners in a visual semantic search task. Our hypothesis is that the level of ESL (English as a Second Language) mastery would infuence the word recognition and oculomotor patterns applied by the participants. Design. Te participants–native Russian speakers–were divided into three groups according to their level of English language mastery. Te experimental task involved a search for horizontally- or vertically-oriented English words in letter matrices (15*15); the frequency and length of the words varied. Performance measures (number and orientation of the found words) were registered, along with the participants’ eye movements. Results. Word search efciency depended on the frequency, length, and orientation of the words and the participant’s language mastery; however, these factors did not interact.Te data show that oculomotor events are denser in experts’ results. Learners with diferent levels of language mastery use different information-processing patterns, which are refected in the proportions of fxation and saccade durations. Two complementary trends were found: word search efciency is efected, frst, by a longer gaze scan path, and second, by the focal mode of visual information-processing, manifested in a combination of longer fxations and shorter saccades. Conclusion. Te registration of eye-movement patterns in visual semantic search tasks reveals the characteristics of efective and non-efective cognitive strategies used by ESL students at diferent levels of language competence

LANGUAGE EXPERIENCE AND VISUAL LEXICAL SEARCH STRATEGIES

The influence of language experience on oculomotor parameters may reflect differences in the features of cognitive strategies in more and less experienced subjects. This study is devoted to identifying differences in the parameters of visual semantic search and cognitive processing of lexical information by subjects of different levels of Russian language proficiency. The data obtained show that with the increase in the level of language competence, the strategies of visual search when working with lexical information are also significantly transformed, indicating the development of more effective methods of cognitive processing.Влияние языкового опыта на глазодвигательные параметры может отражать различия в особенностях когнитивных стратегий у более и менее опытных испытуемых. Данное исследование посвящено выявлению различий в параметрах зрительного семантического поиска и когнитивной обработки лексической информации испытуемыми разного уровня владения русским языком. Полученные данные показывают, что с возрастанием уровня языковой компетентности существенно трансформируются и стратегии зрительного поиска при работе с лексической информацией, свидетельствующие о развитии более эффективных способов когнитивной обработки.Работа выполнена при поддержке проекта РФФИ № 20-013-00674

Semi-Parametric Estimation in Magnetic Resonance Spectroscopy: Automation of the Disentanglement Procedure

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Is spending extra scan time on measuring a \textquoterightmacromolecules-only\textquoteright signal worthwhile?

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Quantification de données d\textquoterightImagerie Spectroscopique en présence d\textquoterighteffets de susceptibilité

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Influence of measured and simulated basis sets on metabolite concentration estimates

articleBy quantification of brain metabolites, localized brain proton MRS can non-invasively provide biochemical information from distinct regions of the brain. Quantification of short-TE signals is usually based on a metabolite basis set. The basis set can be obtained by two approaches: (1) by measuring the signals of metabolites in aqueous solution; (2) by quantum-mechanically simulating the theoretical metabolite signals. The purpose of this study was to compare the effect of these two approaches on metabolite concentration estimates. Metabolite concentrations were quantified with the QUEST method, using both approaches. A comparison was performed with the aid of Monte Carlo studies, by using signals simulated from both basis sets. The best results were obtained when the basis set used for the fit was the same as that used to simulate the Monte Carlo signals. This comparison was also performed using in vivo short-TE signals acquired at 7 T from the central region of rat brains. The concentration estimates, with confidence intervals, obtained using both basis sets were in good agreement with values from the literature. The in vivo study showed that, in general, the differences between the estimates obtained with the two basis sets were not statistically significant or scientifically important. Consequently, a simulated basis set can be used in place of a measured basis set. Copyright (c) 2007 John Wiley \& Sons, Lt

Quantitation of MRSI Data in the Presence of Magnetic Susceptibility Effects

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Metabolite Profiles obtained with QUEST from HRMAS-NMR signals of Rat Brains

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