1,720,962 research outputs found

    The effects of μ-opioid receptor agonists on respiratory neurons in the preBötzinger complex in decerebrate dogs

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    AIM: Systemic administration of μ-opioids at clinical doses for analgesia typically decreases respiratory rate. MORs on preBötC respiratory neurons, the putative kernel of respiratory rhythmogenesis, are potential targets. The purpose of this study was to determine the contribution of the preBötC MORs to the bradypnea produced in vivo by intravenous administration of clinically relevant infusion rates of remifentanil, a short-acting, potent μ- opioid analgesic. METHODS: In decerebrate dogs, multibarrel micropipettes were used to record preBötC neuronal activity and to eject the opioid antagoinist naloxone (NAL, 0.5 mM), the glutamate agonist D-homocysteic acid (DLH, 20 mM), or the MOR agonist (D-Ala2, N-Me-Phe4, gly-ol5)- enkephalin (DAMGO, 100 μM). Inspiratory and expiratory durations (TI and TE) and peak phrenic nerve activity (PPA) were measured from the phrenic neurogram. The preBötC was functionally identified by its rate altering response (typically tachypnea) to DLH microinjection and neuron composition. RESULTS: During intravenous remi-induced bradypnea (~60% decrease in central breathing frequency, fB), bilateral injections of NAL into the preBötC did not change TI, TE, fB, and PPA. Also, NAL picoejected onto single preBötC neurons depressed by intravenous remi had no effect on their discharge. In contrast, ~60 μg/kg of intravenous NAL rapidly reversed all remi- induced effects. In a separate group of dogs, microinjections of DAMGO in the preBötC increased fB by 44%, while subsequent intravenous remi infusion more than offset this DAMGO induced tachypnea. CONCLUSION: These results indicate that μ-opioids at plasma concentrations that cause profound analgesia produced their bradypneic effect via MORs located outside the preBötC region

    The effects of μ-opioid receptor agonists on respiratory neurons in the preBötzinger complex in decerebrate dogs

    No full text
    AIM: Systemic administration of μ-opioids at clinical doses for analgesia typically decreases respiratory rate. MORs on preBötC respiratory neurons, the putative kernel of respiratory rhythmogenesis, are potential targets. The purpose of this study was to determine the contribution of the preBötC MORs to the bradypnea produced in vivo by intravenous administration of clinically relevant infusion rates of remifentanil, a short-acting, potent μ- opioid analgesic. METHODS: In decerebrate dogs, multibarrel micropipettes were used to record preBötC neuronal activity and to eject the opioid antagoinist naloxone (NAL, 0.5 mM), the glutamate agonist D-homocysteic acid (DLH, 20 mM), or the MOR agonist (D-Ala2, N-Me-Phe4, gly-ol5)- enkephalin (DAMGO, 100 μM). Inspiratory and expiratory durations (TI and TE) and peak phrenic nerve activity (PPA) were measured from the phrenic neurogram. The preBötC was functionally identified by its rate altering response (typically tachypnea) to DLH microinjection and neuron composition. RESULTS: During intravenous remi-induced bradypnea (~60% decrease in central breathing frequency, fB), bilateral injections of NAL into the preBötC did not change TI, TE, fB, and PPA. Also, NAL picoejected onto single preBötC neurons depressed by intravenous remi had no effect on their discharge. In contrast, ~60 μg/kg of intravenous NAL rapidly reversed all remi- induced effects. In a separate group of dogs, microinjections of DAMGO in the preBötC increased fB by 44%, while subsequent intravenous remi infusion more than offset this DAMGO induced tachypnea. CONCLUSION: These results indicate that μ-opioids at plasma concentrations that cause profound analgesia produced their bradypneic effect via MORs located outside the preBötC region

    The effects of μ-opioid receptor agonists on respiratory neurons in the preBötzinger complex in decerebrate dogs

    No full text
    AIM: Systemic administration of μ-opioids at clinical doses for analgesia typically decreases respiratory rate. MORs on preBötC respiratory neurons, the putative kernel of respiratory rhythmogenesis, are potential targets. The purpose of this study was to determine the contribution of the preBötC MORs to the bradypnea produced in vivo by intravenous administration of clinically relevant infusion rates of remifentanil, a short-acting, potent μ- opioid analgesic. METHODS: In decerebrate dogs, multibarrel micropipettes were used to record preBötC neuronal activity and to eject the opioid antagoinist naloxone (NAL, 0.5 mM), the glutamate agonist D-homocysteic acid (DLH, 20 mM), or the MOR agonist (D-Ala2, N-Me-Phe4, gly-ol5)- enkephalin (DAMGO, 100 μM). Inspiratory and expiratory durations (TI and TE) and peak phrenic nerve activity (PPA) were measured from the phrenic neurogram. The preBötC was functionally identified by its rate altering response (typically tachypnea) to DLH microinjection and neuron composition. RESULTS: During intravenous remi-induced bradypnea (~60% decrease in central breathing frequency, fB), bilateral injections of NAL into the preBötC did not change TI, TE, fB, and PPA. Also, NAL picoejected onto single preBötC neurons depressed by intravenous remi had no effect on their discharge. In contrast, ~60 μg/kg of intravenous NAL rapidly reversed all remi- induced effects. In a separate group of dogs, microinjections of DAMGO in the preBötC increased fB by 44%, while subsequent intravenous remi infusion more than offset this DAMGO induced tachypnea. CONCLUSION: These results indicate that μ-opioids at plasma concentrations that cause profound analgesia produced their bradypneic effect via MORs located outside the preBötC region

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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