1,721,053 research outputs found
Biogeography of dactylopiidae and human factor
No full textDactylopids hemipterans are used as pigment for food, drugs, cosmetics, handcrafts, and biological control agents. However, no study has reported how the distribution of dactylopids has been influenced by man. The present work had as objective to review the influence of man on geographic distribution of dactylopids. Based in literature, visits to natural habitats of Opuntia host plants and several areas where cochineal was or is produced, the distribution of dactylopiids is discussed with special emphasis in ecology and human factors. Since cactus fossils have not yet been found, it was necessary to look back to the continental drift theory as well as the phylogeny of cactus hosts and related plants. Cacti originated in South America and dispersed to North America; there, specific factors allowed developing new associations as happened to Opuntia and their natural enemies, which coevolved to become new species. Dactylopius coccus, D. confusus, D. bassi, D. opuntiae and D. tomentosus are found in North America, and D. austrinus, D. ceylonicus, D. confertus, D. salmianus and D. zimmermanii in South America. Because of their usefulness to man, both Opuntia and dactilopids are organisms of wide interest for commercial production; the effect is that their distribution, originally Neotropical and Neartic, now encompasses Afrotropical, Australasian, Paleartic and Oriental regions. Some effects of these activities have made that cochineal world production currently reaches more than 2000 t yr-1, but they also created new plagues issues, as seen in the presence of D. opuntiae in Opuntia ficus-indica plantations in Brazil, Spain, and other countries
Recent findings on cochineal: Towards the integration of its knowledge
No full textThe cochineals (Dactylopius spp.) are insects that thrive on Opuntia species which are used due to their high quality colorings properties and as biologic control agents; recently the knowledge on these insects has been increased significantly, most of this new information comes from active members of the Cochineal Working Group. The topics undertaken are wide since this group is integrated by people of almost all disciplines as are artisans, educators, entrepreneurs, historians, producers, scientists, and recently artists. One outstanding advance is about the studies on enzymatic characterization of hemolymph and immunology of cochineal, since it is not damaged by microorganisms, results that may help to design new commercial applications of this insect. Also interesting findings are the studies on cytometry and reproductive biology of cochineal, generating new discussions on its postharvest physiology. The researches on natural enemies of cochineal are focused on their biology and capacity of depredation, these results, as well with those from the studies of selection of resistant Opuntia species to wild cochineal, are of particular interest for facing this plague where cactus pear is important forage. The aims of other studies are to use the residual material after the cochineal is harvested to produce biodiesel and biogas, but also the biomass utilization is studied; the generation of edible mushrooms Pleurotus djamour was significantly augmented when cladodes after hosting cochineal were added to the growing substrate. Beside all this recent findings, the cochineal rearing is increasing through the production that take place in several countries as China, Ethiopia, Mexico, Peru and Spain to cover the also increasing demand of this useful insect. Other problems that must be attended are the plagues and diseases that treat to spread where Opuntia species are of ecological and social interest
Recent findings on cochineal: Towards the integration of its knowledge
No full textThe cochineals (Dactylopius spp.) are insects that thrive on Opuntia species which are used due to their high quality colorings properties and as biologic control agents; recently the knowledge on these insects has been increased significantly, most of this new information comes from active members of the Cochineal Working Group. The topics undertaken are wide since this group is integrated by people of almost all disciplines as are artisans, educators, entrepreneurs, historians, producers, scientists, and recently artists. One outstanding advance is about the studies on enzymatic characterization of hemolymph and immunology of cochineal, since it is not damaged by microorganisms, results that may help to design new commercial applications of this insect. Also interesting findings are the studies on cytometry and reproductive biology of cochineal, generating new discussions on its postharvest physiology. The researches on natural enemies of cochineal are focused on their biology and capacity of depredation, these results, as well with those from the studies of selection of resistant Opuntia species to wild cochineal, are of particular interest for facing this plague where cactus pear is important forage. The aims of other studies are to use the residual material after the cochineal is harvested to produce biodiesel and biogas, but also the biomass utilization is studied; the generation of edible mushrooms Pleurotus djamour was significantly augmented when cladodes after hosting cochineal were added to the growing substrate. Beside all this recent findings, the cochineal rearing is increasing through the production that take place in several countries as China, Ethiopia, Mexico, Peru and Spain to cover the also increasing demand of this useful insect. Other problems that must be attended are the plagues and diseases that treat to spread where Opuntia species are of ecological and social interest
Biogeography of dactylopiidae and human factor
No full textDactylopids hemipterans are used as pigment for food, drugs, cosmetics, handcrafts, and biological control agents. However, no study has reported how the distribution of dactylopids has been influenced by man. The present work had as objective to review the influence of man on geographic distribution of dactylopids. Based in literature, visits to natural habitats of Opuntia host plants and several areas where cochineal was or is produced, the distribution of dactylopiids is discussed with special emphasis in ecology and human factors. Since cactus fossils have not yet been found, it was necessary to look back to the continental drift theory as well as the phylogeny of cactus hosts and related plants. Cacti originated in South America and dispersed to North America; there, specific factors allowed developing new associations as happened to Opuntia and their natural enemies, which coevolved to become new species. Dactylopius coccus, D. confusus, D. bassi, D. opuntiae and D. tomentosus are found in North America, and D. austrinus, D. ceylonicus, D. confertus, D. salmianus and D. zimmermanii in South America. Because of their usefulness to man, both Opuntia and dactilopids are organisms of wide interest for commercial production; the effect is that their distribution, originally Neotropical and Neartic, now encompasses Afrotropical, Australasian, Paleartic and Oriental regions. Some effects of these activities have made that cochineal world production currently reaches more than 2000 t yr-1, but they also created new plagues issues, as seen in the presence of D. opuntiae in Opuntia ficus-indica plantations in Brazil, Spain, and other countries
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
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
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