56 research outputs found
Systematic status of Plectroctena mandibularis Smith and P. conjugata Santschi (Hymenoptera: Formicidae: Ponerini)
Plectroctena mandibularis Smith is the type species of Plectroctena F. Smith. Because there has been some doubt about its distinctness from P. conjugata, several techniques were used to assess the systematic status of the two species. Most crucially, several colony series contained workers of both phenotypes, and where these series included queens or males, the distinguishing feature of these specimens was not consistently related to those of the workers. Queens, males and workers did not manifest qualitative differences between the taxa, and morphological variation was continuous between the two. The putative morphological basis (funicular index) for distinguishing workers of the taxa arose from allometric variation. Putatively diagnostic colour variation in males was related to latitude, but no simple pattern of morphological variation could be correlated with geographical distribution. Plectroctena conjugata is therefore considered a junior synonym of P. mandibularis
The snake family Psammophiidae (Reptilia: Serpentes): phylogenetics and species delimitation in the African sand snakes (Psammophis Boie, 1825) and allied genera
This study constitutes the first evolutionary investigation of the snake family Psammophiidae—the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's familylevel snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris
Description and identification of white grubs (Coleoptera: Scarabaeidae) attacking pineapple crops in South Africa
Larvae of five species of scarabaeid beetles, Asthenopholis subfasciata Blanchard, Trochalus politus Moser, Macrophylla ciliata Herbst, Congela valida Peringuey and Adoretus ictericus Burmeister, and adults of a sixth species, Heteronychus arator (Fabricius), cause considerable economic damage to the root systems of pineapple plants. The biologies of the species differ, making reliable identification essential. Since no convenient method is available to identify them, both field and laboratory keys are provided for the identification of third instar larvae of the six species, and detailed, illustrated descriptions for confirming their identification
Winter absconding as a dispersal mechanism of the Cape honeybee
The dispersal characteristics of the African honeybee, Apis mellifera scutellata, resulted in a greatly mobile hybrid front in the New World, but in Africa its hybridization zone with the Cape honeybee, Apis mellifera capensis, appears very stable.The maintenance of stable hybrid zones is predicated on a balance between dispersal and selection Knowledge on the extent of gene flow from either race is in its infancy, and the probability of successful dispersal by either race has not yet been considered. Both capensis and scutellata are notorious for absconding, capensis the more so for resource-related seasonal absconding in winter. The two races also differ fundamentally in the ways they conserve heat both behaviourally and physiologically. We investigated the energy consumption and colony survival characteristics of capensis in terms of winter absconding in a climate with cycles of warm days interspersed with cold days. These are compared with calculated values for scutellata to assess whether capensis might have a directional gene flow advantage over scutellata in their zone of hybridization
A proposed prioritization system for the management of invasive alien plants in South Africa
Every country has weed species whose presence conflicts in some way with human management objectives and needs. Resources for research and control are limited, so priority should be given to species that are the biggest problem. The prioritization system described in this article was designed to assess objectively research and control priorities of invasive alien plants at a national scale in South Africa. The evaluation consists of seventeen criteria, grouped into five modules, that assess invasiveness, spatial characteristics, potential impact, potential for control, and conflicts of interest for each plant species under consideration. Total prioritization scores, calculated from criterion and module scores, were used to assess a species' priority. Prioritization scores were calculated by combining independent assessments provided by several experts, thus increasing the reliability of the rankings. The total confidence score, a separate index, indicates the reliability and availability of data used to make an assessment. Candidate species for evaluation were identified and assessed by several experts using the prioritization system. The final ranking was made by combining two separate indices, the total prioritization score and the total confidence score. This approach integrates the plant's perceived priority with an index of data reliability. Of the 61 species assessed, those with the highest ranks (Lantana camara, Chromolaena odorata and Opuntia ficus-indica) had high prioritization and high confidence scores, and are thus of most concern. Those species with the lowest ranks, for example, Harrisia martinii, Opuntia spinulifera and Opuntia exaltata, had low prioritization scores and high confidence scores, and thus are of least concern. Our approach to ranking weeds offers several advantages over existing systems because it is designed for multiple assessors based on the Delphi decision-making technique, the criteria contribute equally to the total score, and the system can accommodate incomplete data on a species. Although the choice of criteria may be criticized and the system has certain limitations, it appears to have delivered credible results
Las políticas públicas nacionales de Colombia para la formación de educadores infantiles
El presente trabajo tiene como objetivo delinear el estado del arte de las políticas públicas para la formación del profesorado en los últimos quince años en Colombia, en especial la formación del educador infantil. Para tal fin se realizó una extensa revisión bibliográfica de normativas, artículos y trabajos investigativos en el área. Se apuntan algunos puntos relevantes: el aumento de la importancia de la educación infantil en las últimas décadas, principalmente en el marco de nuevas políticas para la infancia. Aunque la normativa apunta a nuevos e innovadores parámetros educativos, el asistencialismo está en primer orden. Esto se refleja en la visión social de la infancia como momento restringido al cuidado, que disminuye la importancia de las intervenciones educativas planeadas y los aspectos educativos en general, agravado por la falta de profesionales de la educación infantil que fomenten y concreten el área de la educación infantil, y que construyan conocimiento práctico. Se recomienda invertir en la formación de docentes, valorizar la realización de investigación en el área, así como promover mayor profesionalización del personal, tomando medidas para la valorización del profesional de educación infanti
Infecções naturais de mamíferos silvestres em área endêmica de leishmaniose tegumentar do Estado de São Paulo, Brasil
Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region
Characterization of Endotrypanum (Kinetoplastida: Trypanosomatidae), a Unique Parasite Infecting the Neotropical Tree Sloths (Edentata)
Disease concepts and treatment by tribal healers of an Amazonian forest culture
<p>Abstract</p> <p>Background</p> <p>The extensive medicinal plant knowledge of Amazonian tribal peoples is widely recognized in the scientific literature and celebrated in popular lore. Despite this broad interest, the ethnomedical systems and knowledge of disease which guide indigenous utilization of botanical diversity for healing remain poorly characterized and understood. No study, to our knowledge, has attempted to directly examine patterns of actual disease recognition and treatment by healers of an Amazonian indigenous culture.</p> <p>Methods</p> <p>The establishment of traditional medicine clinics, operated and directed by elder tribal shamans in two remote Trio villages of the Suriname rainforest, presented a unique investigational opportunity. Quantitative analysis of clinic records from both villages permitted examination of diseases treated over a continuous period of four years. Cross-cultural comparative translations were articulated of recorded disease conditions through ethnographic interviews of elder Trio shamans and a comprehensive atlas of indigenous anatomical nomenclature was developed.</p> <p>Results</p> <p>20,337 patient visits within the period 2000 to 2004 were analyzed. 75 disease conditions and 127 anatomical terms are presented. Trio concepts of disease and medical practices are broadly examined within the present and historical state of their culture.</p> <p>Conclusion</p> <p>The findings of this investigation support the presence of a comprehensive and highly formalized ethnomedical institution within Trio culture with attendant health policy and conservation implications.</p
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