1,721,004 research outputs found
Factors modulating the mosquitoes Aedes aegypti (Culicidae) blood feeding behaviour and electrophysiological “responses” of labral apical chemoreceptors to adenine nucleotides
No full textThe feeding of Aedes aegypti (L.) on blood is induced by the presence of phagostimulants: adenine nucleotides. Three chemoreceptive cells in the labral apical sensilla can distinguish the presence of adenine nucleotides depending on the other stimulus components. This work aims at correlating the sensory information arising from the labral apical sensilla with the feeding behavior in response to the same stimuli. The saline stimulating solution, containing adenine nucleotides, is modulated by changing one of the following components: salt concentration, buffer or pH. Cell 3 that responds to NaCl in a dose dependent manner seems to have another unique modality. The response of this cell is unaffected by ATP when the stimulating solution is NaCl buffered by NaHCO3. It responds at a higher spike frequency to the presence of ATP in a NaCl solution without NaHCO3. Thus in the presence of ATP Cell 3 detects whether the NaCl solution is buffered by NaHCO3. Both the blood feeding response and the sensory information from Cell 2 (which responds at high spike frequencies to the presence of ATP) are modulated by pH in a similar way. Both responses present a bi-modal response, with a major peak at pH 4.0 and a moderate peak at the most alkaline pH value tested
Sensitivity of the mosquitoes Aedes aegypti (Culicidae) labral apical chemoreceptors to blood plasma phagostimulats
No full textSensitivity of the mosquitoes Aedes aegypti (Culicidae) labral apical chemoreceptors to blood plasma components
No full textSensitivity of the mosquito Aedes aegypti (Culicidae) labral apical chemoreceptors to blood plasma components
No full textThe feeding of Aedes aegypti (L.) on blood and nectar is induced by phagostimulants: adenine nucleotides and sugars respectively. This work examines the response of the four chemoreceptor cells in the labral apical sensilla to these phagostimulants. The apical chemoreceptors can detect the presence of adenine nucleotides. This part of the response is in good agreement with the gorging behavior. The output of the chemoreceptors cannot distinguish among different adenine nucleotides or among their concentrations (0.01-1 mmol/l), whereas gorging behavior is affected by the identity of adenine nucleotides and by their concentrations. Hence the gorging behavior cannot be driven by the output of these response of Cell 4 was almost abolished. The response of Cell 2 to ATP depended on the mosquito's physiological state. This dependence accorded well with the gorging behavior; Cell 2 responded with a higher frequency to ATP in the gorging state, than when not in a gorging state. The responses to sucrose and fructose constituted the only case recorded in which all these chemoreceptors failed to respond. This depression of response implies that other chemoreceptors must be present as sugar detectors
Electrophysiological responses of labral apical chemoreceptors to adenine nucleotides in Culex pipiens
No full textElectrophysiological recordings show that the hair-like sensilla on the tip of the labrum in Culex Pipiens L. have neurones that respond to adenine nucleotides. Adenine nucleotides show the following descending order of stimulating effectiveness: ADP > ATP = AMP-PNP = AMP. Sensillar sensitivity to these adenine nucleotides were tested at the concentration range of 10(-5)-10(-3) M. These electrophysiological data are in good accordance with data reported from behavioural studies of this species
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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