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Selected AbstractsEnhanced mismatch negativity brain response after binaural word presentationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2004Tanja Endrass Abstract An oddball paradigm was used to investigate brain processes elicited by spoken words and pseudowords played monaurally, to the left or right ear, or simultaneously to both ears of human subjects instructed to ignore acoustic stimuli but watch a silent video film. The mismatch negativity (MMN), a neurophysiological index of the automatic activation of cortical memory traces, was calculated as the difference between the event-related potential elicited by an infrequent deviant stimulus and the event-related potential to the same item presented as a frequent standard stimulus. Consistent with earlier reports, the MMN to words was larger than that to pseudowords, possibly reflecting the existence of memory traces for spoken words. Bilateral redundant stimulus presentation led to a further increase of the MMN to words relative to both unilateral stimulation modes. This bilateral redundancy gain was absent for pseudowords. We interpret the neurophysiological manifestation of a word-specific bilateral redundancy gain as evidence for interhemispheric cooperation in the automatic access to memory traces for spoken words. Accordingly, word-related cortical networks distributed over both hemispheres allow summation of neural activity between and within hemispheres, thereby potentiating the word-related MMN. [source] The transshipment fund mechanism: Coordinating the decentralized multilocation transshipment problemNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 4 2010Eran Hanany Abstract The multilocation replenishment and transshipment problem is concerned with several retailers facing random demand for the same item at distinct markets, that may use transshipments to eliminate excess inventory/shortages after demand realization. When the system is decentralized so that each retailer operates to maximize their own profit, there are incentive problems that prevent coordination. These problems arise even with two retailers who may pay each other for transshipped units. We propose a new mechanism based on a transshipment fund, which is the first to coordinate the system, in a fully noncooperative setting, for all instances of two retailers as well as all instances of any number of retailers. Moreover, our mechanism strongly coordinates the system, i.e., achieves coordination as the unique equilibrium. The computation and information requirements of this mechanism are realistic and relatively modest. We also present necessary and sufficient conditions for coordination and prove they are always satisfied with our mechanism. Numerical examples illustrate some of the properties underlying this mechanism for two retailers. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010 [source] A construction based analysis of child directed speechCOGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 6 2003Thea Cameron-Faulkner Abstract The child directed speech of twelve English-speaking motherswas analyzed in terms of utterance-level constructions. First, the mothers' utterances were categorized in terms of general constructional categories such as Wh-questions, copulas and transitives. Second, mothers' utterances within these categories were further specified in terms of the initial words that framed the utterance, item-based phrases such as Are you ,, I'll ,, It's ,, Let's ,, What did , The findings were: (i) overall, only about 15% of all maternal utterances had SVO form (most were questions, imperatives, copulas, and fragments); (ii) 51% of all maternal utterances began with one of 52 item-based phrases, mostly consisting of two words or morphemes (45% began with one of just 17 words); and (iii) children used many of these same item-based phrases, in some cases at a rate that correlated highly with their own mother's frequency of use. We suggest that analyses of adult,child linguistic interaction should take into account not just general constructional categories, but also the item-based constructions that adults and children use and the frequency with which they use them. [source] Feeding ecology of fishes associated with Egeria spp. patches in a tropical reservoir, BrazilECOLOGY OF FRESHWATER FISH, Issue 1 2006F. M. Pelicice Abstract ,, This research characterised feeding ecology of fishes associated with patches of Egeria najas and Egeria densa, two submerged macrophytes, in Rosana Reservoir, Upper Paraná River basin, Brazil. Fishes were sampled using a 1 m2 throw trap in patches of different macrophyte biomass and in three diel periods during a wet season. Fish diet (10 species) was primarily composed of autochthonous items (zooplankton, algae and aquatic insect larvae). Almost all intra-specific diet patterns had moderate to low levels of diet similarity, indicating a high variability in diet. Some species showed no diel patterns in feeding activity, whereas others were primarily diurnal or nocturnal. No differences in feeding activity were observed among habitats of medium and high macrophyte biomasses, and species tended to feed on the same items among these habitats. The most abundant fish species demonstrated low inter-specific diet overlap and appear not to compete for food resources. We suggest that Egeria patches are feeding grounds and shelter for small-sized fish species. Resumen 1. Esta investigación caracterizó la ecología trófica de las especies de peces asociadas a manchas de Egeria najas e E. densa, dos macrofitas sub-aquaticas, en la represa de Rosana (alto Río Paraná, Brasil). Los peces fueron colectados con un throw trap de 1 m2 en manchas con distintas biomasas de macrófitas y en tres períodos del día, durante la estación lluviosa. 2. La dieta de 10 especies estuvo compuesta principalmente de componentes autóctonos (zooplancton, algas y larva de insectos acuáticos). Casi todas las especies presentaron patrones de dieta intra-específica con similitudes moderadas o bajas (elevada variabilidad). Algunas especies no mostraron ningún patrón de actividad alimenticia durante el día mientras que otras fueron principalmente diurnas o nocturnas. No se observó ninguna diferencia de actividad alimenticia entre los habitats de media y alta biomasa de macrófitas, y las especies tendieron a alimentarse de los mismos componentes entre estos habitats. 3. Las especies de peces más abundantes mostraron un solapamiento alimenticio bajo y parecen no competir por recursos alimenticios. Sugerimos que las manchas de Egeria funcionan como lugar de alimentación y abrigo para los peces de pequeño tamaño. [source] Verbal memory improved by D -amphetamine: influence of the testing effectHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2010Inge Zeeuws Abstract Objective The improvement of long-term retention of verbal memory after an acute administration of D -amphetamine in recall and recognition tasks has been ascribed to an influence of the drug on memory consolidation. Because recent research has demonstrated that intermediate testing is of overriding importance for retention, we investigated whether D -amphetamine modulates the repeated testing effect in verbal long-term recognition. Method Forty men participated in two double blind placebo controlled studies. In Experiment 1, we manipulated the number of recognition tests and in Experiment 2, we compared repeated with nonrepeated testing of the same items. Results Drug effects were observed on delayed tests only, leaving immediate recognition unaffected. Number of intermediate recognition tests and repeated testing of the same items were not affected by D -amphetamine. Conclusions We conclude that the D -amphetamine memory enhancement is not related to the testing effect. This result supports that D -amphetamine modulates other aspects of the consolidation process, probably related to context effects. Copyright © 2010 John Wiley & Sons, Ltd. [source] Revisiting the Sense of Community Index: A confirmatory factor analysisJOURNAL OF COMMUNITY PSYCHOLOGY, Issue 6 2004Patricia L. Obst The Sense of Community Index (SCI) is one of the most commonly used measures of Psychological Sense of Community (PSOC). There is much discussion in the literature as to the validity of the scale as a measure not only of overall PSOC, but also of the dimensions (Membership, Influence, Needs Fulfillment, and Emotional Connection) theorized by McMillan and Chavis (1986) to underlie the construct. The current paper examines the factor structure of SCI in a study ( N = 219) that examines multiple community memberships, including neighborhood, student, and interest group communities. Data was analyzed by confirmatory factor analysis (CFA). The results showed that the SCI, in its original factor structure, did not adequately fit the data. The scale was revised, therefore, using CFA indicators, to produce a new four-factor structure based on the same items. This revised model was tested and found to display adequate fit indices to the data in all three communities. The results of the study provide empirical support for retaining measures that encapsulate the four dimensions of PSOC. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 691,705, 2004. [source] A typology of motor vehicle consumers using motives for leasing versus financingJOURNAL OF CONSUMER BEHAVIOUR, Issue 4 2006Philip J. Trocchia Previous consumer research suggests that individuals who finance high-cost items tend to differ from those who lease the same items. Some differences are economic, such as income and wealth, while other dissimilarities involve non-economic issues such as personal preferences. We employ non-hierarchical cluster analysis to create consumer segments of motor vehicle lessees and financers based on motives for leasing versus financing and demographics. Five segments were uncovered. Lessees predominate in two categories: budget gourmets and automotive hedonists. Another two categories, utility seekers and basic transportation seekers, are mainly comprised of financers. The final group, mature luxury seekers, consists of a roughly equal mix of lessees and financers. Differences between the segments are addressed here, along with a discussion of findings and implications. Copyright © 2006 John Wiley & Sons, Ltd. [source] | |||||||||||||