1,721,305 research outputs found
Efectos letales y subletales de dos plaguicidas sobre las especies Uca uruguayensis y Chasmagnathus granulata,(Cangrejal Bonaerense)
No full textFil: Rodriguez, Enrique Marcelo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Efectos letales y subletales de dos plaguicidas sobre las especies Uca uruguayensis y Chasmagnathus granulata,(Cangrejal Bonaerense)
Get PDFFil: Rodriguez, Enrique Marcelo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Endocrine disruption by pollutants and effects on progeny
No full textAs mentioned in Chapter 10, hormonally-regulated functions of crustaceans have been reviewed during the last years by several authors. Main endocrine-regulated processes of crustaceans involve moulting, reproduction, glycemia levels, and pigment migration, among others. Several pollutants, such as pesticides, alkylphenols, polychlorinated biphenyls, hydrocarbons, and heavy metals, can interfere with these processes, therefore acting as endocrine-disrupting compounds (ECDs) on crustaceans, as reviewed by several authors (LeBlanc 2007, Rodríguez et al. 2007, deFur et al. 1999). The hyperglycemic crustacean hormone (CHH) belongs to a highly diversified family of peptide hormones, secreted by the sinus gland at the eyestalks (Nagaraju 2011, Fingerman 1997). This hormone has been considered as the “stress hormone” of crustaceans (Chang et al. 1999). In some cases, a hyperglycemic response has been observed following exposure to cadmium (Reddy et al. 2009), but an eventual inhibition of the CHH synthesis has also been reported (Reddy et al. 1996). Hyperglycemia caused by heavy metals in shrimps also showed dependence on both the time of exposure and concentration (Lorenzon et al. 2000). An inhibition of moulting by several estrogenic compounds, as well as by testosterone, antiandrogens, antiestrogens, and some pesticides, has been reported in daphnids and copepods (LeBlanc 2007, Andersen et al. 2001, Zou and Fingerman 1997). Besides, evidence about a possible antagonism of these compounds with the transductional pathway of ecdysone at target tissues has been provided (Mu and LeBlanc 2002a). Juvenoid compounds, such as methoprene and JHIII have also inhibited moulting, perhaps interfering with the stimulating effect of the juvenoid hormone methyl farnesoate (Olmstead and LeBlanc 2001). Regarding reproduction, several estrogenic compounds, both natural and synthetic, as well as some juvenoids and ecdysteroids, have shown to exert an abnormal stimulation on several aspects of crustacean reproduction. Observed effects were mainly the abnormal development of secondary sexual characters in both sexes, and a shift to all-female or allmale broods. These effects were observed in daphnids (Dodson et al. 1999, Olmstead and LeBlanc 2000), copepods (Andersen et al. 1999), and amphipods (Brown et al. 1999, Watts et al. 2002).Fil: Rodriguez, Enrique Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental. Laboratorio de Fisiologia de Crustáceos; ArgentinaFil: Medesani, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental. Laboratorio de Fisiologia de Crustáceos; ArgentinaFil: López Greco, Laura S.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Biología de la Reproducción y Crecimiento de Crustáceos Decápodos; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Endocrine disruption in crustaceans: New findings and perspectives
No full textA significant advance has been made, especially during the last two decades, in the knowledge of the effects on crustacean species of pollutants proven to be endocrine disruptors in vertebrates. Such effects have been also interpreted in the light of recent studies on crustacean endocrinology. Year after year, the increased number of reports refer to the effects of endocrine disruptors on several processes hormonally controlled. This review is aimed at summarizing and discussing the effects of several kinds of endocrine disruptors on the hormonal control of reproduction (including gonadal growth, sexual differentiation, and offspring development), molting, and intermediate metabolism of crustaceans. A final discussion about the state of the art, as well as the perspective of this toxicological research line is given.Fil: Rodriguez, Enrique Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
- …
