281 research outputs found

    Collocational Processing in L1 and L2: The Effects of Word Frequency, Collocational Frequency, and Association

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    This study investigated the effects of individual word frequency, collocational frequency, and association on L1 and L2 collocational processing. An acceptability judgment task was administered to L1 and L2 speakers of English. Response times were analyzed using mixed‐effects modeling for 3 types of adjective–noun pairs: (a) high‐frequency, (b) low‐frequency, and (c) baseline items. This study extends previous research by examining whether the effects of individual word and collocation frequency counts differ for L1 and L2 speakers’ processing of collocations. This study also compared the extent to which L1 and L2 speakers’ response times are affected by mutual information and log Dice scores, which are corpus‐derived association measures. Both groups of participants demonstrated sensitivity to individual word and collocation frequency counts. However, there was a reduced effect of individual word frequency counts for processing high‐frequency collocations compared to low‐frequency collocations. Both groups of participants were similarly sensitive to the association measures used

    Upper Maastrichtian and Danian bryozoans from Northern Patagonia, Argentina

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    The specimen-rich and diverse bryozoan fauna encrusting oyster shells from the Maastrichtian and Danian JagĂŒel and Roca formations in the NeuquĂ©n Basin (Patagonia, Argentina) is described. Thirteen cyclostome species are recorded, along with 18 cheilostomes. We introduce two new species: Akatopora kaufmanni sp. nov. and Eoporella lunata gen. et sp. nov. The latter is a homeomorph of the common Miocene–Recent genus Microporella. Ten of the cyclostomes and ten of the cheilostomes could not be identified at species-level because of preservational limitations or lack of diagnostic characters in the available specimens. The most common bryozoans present are sheet-like colonies, among which the ascophoran cheilostome Balantiostoma is particularly well represented. Results show that in northern Patagonia the diversity of encrusting bryozoans associated with oyster shells exhibits no major changes across the K/Pg boundary. However, an important increase in the diversity is recorded during the upper Danian.Fil: Brezina, Soledad Silvana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn en PaleobiologĂ­a y GeologĂ­a; ArgentinaFil: Taylor, Paul D.. Natural History Museum; Reino UnidoFil: Romero, MarĂ­a V.. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: PalĂłpolo, Evangelina Elizabeth. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn en PaleobiologĂ­a y GeologĂ­a; ArgentinaFil: Casadio, Silvio Alberto. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn en PaleobiologĂ­a y GeologĂ­a; Argentin

    Long-Term Stability of Visual Pattern Selective Responses of Monkey Temporal Lobe Neurons

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    Many neurons in primate inferotemporal (IT) cortex respond selectively to complex, often meaningful, stimuli such as faces and objects. An important unanswered question is whether such response selectivity, which is thought to arise from experience-dependent plasticity, is maintained from day to day, or whether the roles of individual cells are continually reassigned based on the diet of natural vision. We addressed this question using microwire electrodes that were chronically implanted in the temporal lobe of two monkeys, often allowing us to monitor activity of individual neurons across days. We found that neurons maintained their selectivity in both response magnitude and patterns of spike timing across a large set of visual images throughout periods of stable signal isolation from the same cell that sometimes exceeded two weeks. These results indicate that stimulus-selectivity of responses in IT is stable across days and weeks of visual experience

    Consistency and diversity of spike dynamics in the neurons of bed nucleus of Stria Terminalis of the rat: a dynamic clamp study

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    Neurons display a high degree of variability and diversity in the expression and regulation of their voltage-dependent ionic channels. Under low level of synaptic background a number of physiologically distinct cell types can be identified in most brain areas that display different responses to standard forms of intracellular current stimulation. Nevertheless, it is not well understood how biophysically different neurons process synaptic inputs in natural conditions, i.e., when experiencing intense synaptic bombardment in vivo. While distinct cell types might process synaptic inputs into different patterns of action potentials representing specific "motifs'' of network activity, standard methods of electrophysiology are not well suited to resolve such questions. In the current paper we performed dynamic clamp experiments with simulated synaptic inputs that were presented to three types of neurons in the juxtacapsular bed nucleus of stria terminalis (jcBNST) of the rat. Our analysis on the temporal structure of firing showed that the three types of jcBNST neurons did not produce qualitatively different spike responses under identical patterns of input. However, we observed consistent, cell type dependent variations in the fine structure of firing, at the level of single spikes. At the millisecond resolution structure of firing we found high degree of diversity across the entire spectrum of neurons irrespective of their type. Additionally, we identified a new cell type with intrinsic oscillatory properties that produced a rhythmic and regular firing under synaptic stimulation that distinguishes it from the previously described jcBNST cell types. Our findings suggest a sophisticated, cell type dependent regulation of spike dynamics of neurons when experiencing a complex synaptic background. The high degree of their dynamical diversity has implications to their cooperative dynamics and synchronization

    Q fever in Bulgaria and Slovakia.

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    As a result of dramatic political and economic changes in the beginning of the 1990s, Q-fever epidemiology in Bulgaria has changed. The number of goats almost tripled; contact between goat owners (and their families) and goats, as well as goats and other animals, increased; consumption of raw goat milk and its products increased; and goats replaced cattle and sheep as the main source of human Coxiella burnetii infections. Hundreds of overt, serologically confirmed human cases of acute Q fever have occurred. Chronic forms of Q fever manifesting as endocarditis were also observed. In contrast, in Slovakia, Q fever does not pose a serious public health problem, and the chronic form of infection has not been found either in follow-ups of a Q-fever epidemic connected with goats imported from Bulgaria and other previous Q-fever outbreaks or in a serologic survey. Serologic diagnosis as well as control and prevention of Q fever are discussed
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