1,778 research outputs found

    Otolith morphology of Nezumia sclerorhynchus and Nezumia aequalis (Macrouridae): a useful tool to species identification and ecological studies

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    Bol. Mus. Mun. Funchal, Sup. N.º 6: 205-212, 2001Otoliths of Nezumia sclerorhynchus and N. aequalis are described and compared. When studying the marine trophic relationships, its general shape and morphometry allows one to separated these two sympatric species.São descritos e comparados os otólitos sagitta de Nezumia sclerorhynchus e de N. aequalis. No estudo das relações tróficas marinhas a sua forma e morfometria permitem distinguir qual destas duas espécies simpátricas foi predada

    The impact of the oil spill of the tanker “Aragon” on the littoral fish fauna of Porto Santo (NE Atlantic Ocean) in 1991 and ten years later

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    Bocagiana, 217: 1-8Em Janeiro de 1990, a Ilha de Porto Santo (Arquipélago da Madeira), foi atingida por uma maré negra proveniente de um derrame do navio petroleiro “Aragon”. Um ano depois, avaliou-se a ictiofauna costeira. Dez anos depois da maré negra, uma nova amostragem foi realizada com a mesma metodologia, de forma a comparar com os dados recolhidos anteriormente. A análise dos resultados obtidos parece revelar que os efeitos da maré negra nos peixes litorais foram reduzidos. Este trabalho constitui a primeira contribuição para a “check-list” da ictiofauna costeira da Ilha de Porto Santo.In January 1990, the tanker “Aragon” oil spill reached Porto Santo Island (Madeira Archipelago). One year later, in 1991 the littoral fish fauna was evaluated. Ten years after the “Aragon” oil spill, a new survey was made using the same methods, to compare data. From the results it seems that the effects of the oil were rather small. As a result of this work, as a check-list of the littoral fish fauna of this Island is presented

    Descending inhibitory systems

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    The authors have been supported by the Academy of Finland (grant 78582), the Sigrid Jusélius Foundation, Finland, Grünenthal Foundation, Portugal and Project no POCTI/NSE/46399/2002 from FCT and FEDER, Portugal. The authors wish to thank Dr. Denis Artchakov for illustrations

    El minicomputador de Papy: una estrategia didáctica para comprender y fortalecer las operaciones básicas

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    Esta propuesta, del proyecto Juega y Construye la Matemática, tiene como fin presentar una estrategia metodológica como herramienta en el proceso de aprendizaje de las operaciones elementales, por medio de la utilización del minicomputador de Papy, con base en las experiencias realizadas en los colegios Maristas de Colombia. En este trabajo se evidencia el valor pedagógico del juego y de la incorporación en forma adecuada de las nuevas tecnologías de la información para la formación del pensamiento matemático. El minicomputador de Papy, es un ejercitador que nos permite desarrollar en los niños conceptos como la composición y descomposición de números utilizando el esquema multiplicativo y aditivo. Además, otra estrategia que permite el minicomputador de Papy es realizar las operaciones suma, resta, multiplicacion y división, de las cuales nos encargaremos en esta experiencia de aula

    El minicomputador de PAPY una estrategia didáctica para comprender y fortalecer las operaciones básicas

    Get PDF
    Esta propuesta tiene como fin, presentar una estrategia metodológica como herramienta en el proceso de aprendizaje de las operaciones elementales, por medio de la utilización del minicomputador de papy, con base en las experiencias realizadas en los colegios maristas de Colombia. En este trabajo se evidencia el valor pedagógico del juego y de la incorporación en forma adecuada de las nuevas tecnologías de la información para la formación del pensamiento matemático. El minicomputador de papy, es un ejercitador que nos permite desarrollar en los niños conceptos como la composición y descomposición de números utilizando el esquema multiplicativo y aditivo. Además, otra estrategia que permite el minicomputador de Papy es realizar las operaciones suma, resta, multiplicación y división, de las cuales nos encargaremos en esta experiencia de aula

    Pronociceptive changes in response properties of rostroventromedial medullary neurons in a rat model of peripheral neuropathy

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    The spared nerve injury (SNI) model of peripheral neuropathy produces a robust and long-lasting hypersensitivity. Previous behavioural studies suggest that brainstem–spinal pathways originating in or relaying through the rostroventromedial medulla (RVM) contribute to neuropathic hypersensitivity. We determined whether SNI induces changes in response properties of RVM neurons that might influence descending modulation of nociception. RVM neurons included in the study were classified into presumably pronociceptive ON-cells and antinociceptive OFF-cells (giving excitatory or inhibitory responses to noxious stimulation, respectively). Spontaneous activity and the response to cold, pinch and colorectal distension were assessed under light anaesthesia in the rat, 1 week and 8 weeks following nerve injury or sham operation. Spontaneous activity was increased 1 week but not 8 weeks after nerve injury in ON-cells but decreased in OFF-cells at both time points. In the SNI group, cold-evoked responses were enhanced particularly in ON-cells, independent of the postoperative time point. Responses of ON-cells to pinch and visceral stimulation were enhanced 8 weeks but not 1 week following nerve injury, whereas OFF-cell responses to pinch or colorectal distension were not changed. The results indicate that SNI induces pronociceptive changes in spontaneous activities of ON-cells and OFF-cells and peripherally evoked responses of ON-cells that vary with the postoperative time point. Increased ON-cell activity and decreased OFF-cell activity in the RVM are likely to enhance spinal nociception in a tonic fashion, whereas increased responses of ON-cells to peripheral stimulation are likely to enhance ascending nociceptive signals by a positive feedback following peripheral noxious stimulation

    Enzyme purification with aqueous two-phase systems: comparison between systems composed of pure polymers and systems composed of crude polymers

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    The main drawback when using aqueous two-phase systems for macromolecule purification is the high cost of most polymers used. The purification of an enzyme, alcohol dehydrogenase, from a crude extract of Saccharomyces cerevisiae was tested in systems composed of poly(ethylene glycol) and a crude hydroxypropyl starch or Reppal PES 100, a purified fraction of hydroxypropyl starch. Purification factors measured for the enzyme were very similar in both systems (between 0.8 and 1.4 for both systems in the upper phase). However, systems composed of Reppal PES present a greater recovery of enzyme, between 77% and 100% versus 60% and 100%, while systems composed of crude hydroxypropyl starch exhibit a larger Δlog K for the tested ligand, 1.26 versus 0.81.Junta Nacional de Investigação Científica e Tecnológica (JNICT)

    Intraepithelial nerve fibers project into the lumen of the larynx

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    Objectives/Hypothesis: Studies on the morphology and location of the sensory receptors in the laryngeal mucosa have resulted in insufficient and sometimes conflicting data. In the present study the authors analyzed the distribution and morphology of sensory nerve plexuses and terminal fibers in the laryngeal mucosa of the rat. Study Design: Two groups of Male Wistar rats were used in this laboratory study; the larynx of the first group were used to analyse the sensitive innervation of its epithelium, whereas the larynx of the second group (controls) were tested for the specificity of the antibodies used. Methods: The larynges of the animals were entirely removed after perfusion, and coronal or horizontal sections were immunoprocessed for further randomized analysis of the mucosa. Primary afferents were detected by immunoreaction to two widely recognized markers of sensory nerves, calcitonin generelated peptide and substance P, and visualized using diaminobenzidine as a chromogen. Results: The nerve plexuses were more densely distributed in the dorsal half of the vocal folds and in the laryngeal aspect of the epiglottis. Dense networks of fine fibers with many varicosities en passant, immunoreactive for both calcitonin gene-related peptide and substance P, occurred in the lamina propria and along the epithelial thickness. Calcitonin gene-related peptide– immunoreactive and substance P–immunoreactive fibers extended across the epithelium and projected to the laryngeal lumen itself, reaching the space between the cilia. Conclusion: The projection of intraepithelial nerve fibers into the lumen of the larynx indicates that in the absence of mucus, nerve endings may be exposed and thus receive direct stimulation from airborne substances. Furthermore, it suggests that the laryngeal mucosa of the rat may constitute an experimental model for studying the direct activation or manipulation of primary afferents at the periphery and neurogenic inflammation.União Europeia (UE). Fundo Europeu de Desenvolvimento Regional (FEDER).Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência, Tecnologia, Inovação” (POCTI) - POCTI/NSE/46399/2002.Grunenthal Foundation
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