257 research outputs found

    Overfishing and the replacement of demersal finfish by shellfish: an example from the English Channel.

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    The worldwide depletion of major fish stocks through intensive industrial fishing is thought to have profoundly altered the trophic structure of marine ecosystems. Here we assess changes in the trophic structure of the English Channel marine ecosystem using a 90-year time-series (1920-2010) of commercial fishery landings. Our analysis was based on estimates of the mean trophic level (mTL) of annual landings and the Fishing-in-Balance index (FiB). Food webs of the Channel ecosystem have been altered, as shown by a significant decline in the mTL of fishery landings whilst increases in the FiB index suggest increased fishing effort and fishery expansion. Large, high trophic level species (e.g. spurdog, cod, ling) have been increasingly replaced by smaller, low trophic level fish (e.g. small spotted catsharks) and invertebrates (e.g. scallops, crabs and lobster). Declining trophic levels in fisheries catches have occurred worldwide, with fish catches progressively being replaced by invertebrates. We argue that a network of fisheries closures would help rebalance the trophic status of the Channel and allow regeneration of marine ecosystems

    The use of brain electrophysiology techniques to study language: A basic guide for the beginning consumer of electrophysiology information

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    ABSTRACT This article provides a basic background for the professional who is interested in utilizing event-related potential (ERP) approaches to study language processes but has little background or knowledge of the technique. First, a brief history of the emergence of this technology is presented, followed by definitions, a theoretical overview, and a practical guide to conducting ERP studies. The bases for choice of electrode positions, equipment characteristics (e.g., filter settings), and analyses are also discussed. Finally, examples of language studies that utilize this information in a research study are provided. 3 The use of brain electrophysiology techniques to study language: A basic guide for the beginning consumer of electrophysiology information. Dennis L. Molfese, Victoria J. Molfese, and Spencer Kelly University of Louisville There has been a long-standing interest by researchers and theorists in brain-behavior relations. This interest has led to the development and adaptation of instruments and methodologies that measure the brain's responses for use in studying developmental issues. Techniques such as electroencephalography (EEG), event-related potentials (ERP), and brainstem evoked response (BSER) all share a common approach to cortical electrophysiology -scalp electrodes are used to detect electrical activity generated by the brain. These techniques can provide insights into brain-behavior developmental issues that complement and supplement information obtained through more traditional behavioral measures. This article reviews the history of cortical electrophysiological approaches to investigate brainbehavior relations. An overview of the procedure is provided along with rationales for various components of it. We briefly will also comment on how these approaches compare to other techniques, such as Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), and functional Magnetic Resonance Imaging (fMRI). A final section will describe the current use of ERP techniques in longitudinal research to investigate the relation between brain functioning in infancy and subsequent cognitive and language development in school aged children, with a focus on reading and reading disability

    Gastrointestinal electric stimulation in the dog

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    Los autores utilizando un marcapaso intestinal Modelo M. 1 100 aplicaron estímulos eléctricos en forma directa sobre la mucosa del tubo digestivo (estómago, yeyuno, colon) de perros logrando aumentar el peristaltismo tanto en tiempo como en intensidad de contracción con un franco incremento del tono entre los estímulos. Asimismo después de 5 a 6 horas de provocar choques eléctricos en forma ininterrumpida comprobaron que no se presentaban signos de agotamiento. En base a ello concluyen que el método es útil e inocuo en los cuadros de ileo paralítico de las más diversas etiologías tanto en humanos como en animales.The authors had been used an intestinal passmaker Model M. 1.100, electric stimulation were applied directly over digestive tube mucosal (stomach, yeyun and colon) on dogs. Success were found on peristaltism frequency on time and contraction intensity with increase of tone between stimulations. After 5 to 6 hours of electric shock in continuous form were proved that no sign of exhausted were present. On this base was concluded that the method is useful and not cause damages in paralytic ileum cause by different etiologies in human and animals.Facultad de Ciencias Veterinaria

    Gastrointestinal electric stimulation in the dog

    Get PDF
    Los autores utilizando un marcapaso intestinal Modelo M. 1 100 aplicaron estímulos eléctricos en forma directa sobre la mucosa del tubo digestivo (estómago, yeyuno, colon) de perros logrando aumentar el peristaltismo tanto en tiempo como en intensidad de contracción con un franco incremento del tono entre los estímulos. Asimismo después de 5 a 6 horas de provocar choques eléctricos en forma ininterrumpida comprobaron que no se presentaban signos de agotamiento. En base a ello concluyen que el método es útil e inocuo en los cuadros de ileo paralítico de las más diversas etiologías tanto en humanos como en animales.The authors had been used an intestinal passmaker Model M. 1.100, electric stimulation were applied directly over digestive tube mucosal (stomach, yeyun and colon) on dogs. Success were found on peristaltism frequency on time and contraction intensity with increase of tone between stimulations. After 5 to 6 hours of electric shock in continuous form were proved that no sign of exhausted were present. On this base was concluded that the method is useful and not cause damages in paralytic ileum cause by different etiologies in human and animals.Facultad de Ciencias Veterinaria

    Impairments in Attention in Occasionally Snoring Children: An Event-Related Potential Study

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    Objective—To determine whether minimal snoring is benign in children. Procedure—22 rarely snoring children (mean age=6.9 years, 11 females) and age- and sexmatched controls participated in an auditory oddball task wearing 128-electrode nets. Parents completed Conner’s Parent Rating Scales-Revised Long (CPRS-R:L). Results—Snorers scored significantly higher on 4 CPRS-R:L subscales. Stepwise regression indicated that two ERP variables from a region of the ERP that peaked at 844 ms post-stimulus onset predicted CPRS-R:L ADHD Index scores. Conclusions—Occasional snorers according to parental report do exhibit ADHD-like behaviors. Basic sensory processing is longer than in controls, suggesting that delayed frontal activation requires more effort in snorers

    VST: the telescope progress toward stars

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    The VST telescope is in an advanced stage of integration in Chile, after a period of work spent mainly on the active optics system, started in mid-2007. We present the results of the recent work on the primary and secondary mirror support systems and on the mirror cell auxiliary units

    The proper name as starting point for basic reading skills

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    Does alphabetic-phonetic writing start with the proper name and how does the name affect reading and writing skills? Sixty 4- to 5½-year-old children from middle SES families with Dutch as their first language wrote their proper name and named letters. For each child we created unique sets of words with and without the child’s first letter of the name to test spelling skills and phonemic sensitivity. Name writing correlated with children’s knowledge of the first letter of the name and phonemic sensitivity for the sound of the first letter of the name. Hierarchical regression analysis makes plausible that both knowledge of the first letter’s name and phonemic sensitivity for this letter explain why name writing results in phonetic spelling with the name letter. Practical implications of the findings are discussed

    Executive Functions of Six-Year-Old Boys with Normal Birth Weight and Gestational Age

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    Impaired fetal development, reflected by low birth weight or prematurity, predicts an increased risk for psychopathology, especially attention deficit hyperactivity disorder (ADHD). Such effects cut across the normal range of birth weight and gestation. Despite the strength of existing epidemiological data, cognitive pathways that link fetal development to mental health are largely unknown. In this study we examined the relation of birth weight (>2500 g) and gestational age (37–41 weeks) within the normal range with specific executive functions in 195 Singaporean six-year-old boys of Chinese ethnicity. Birth weight adjusted for gestational age was used as indicator of fetal growth while gestational age was indicative of fetal maturity. Linear regression revealed that increased fetal growth within the normal range is associated with an improved ability to learn rules during the intra/extra-dimensional shift task and to retain visual information for short period of time during the delayed matching to sample task. Moreover, faster and consistent reaction times during the stop-signal task were observed among boys born at term, but with higher gestational age. Hence, even among boys born at term with normal birth weight, variations in fetal growth and maturity showed distinct effects on specific executive functions
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