Robert Hayden: 03-03-1975

Hayden talks about being a poor teenager in Detroit trying to write poems like Cullen and Hughes and about his later shift away from specifically African American themes. He sees a parallel between his life and Yeats\u27s life as an Irish poet; both worked to not be limited by their heritages. Hayden uses folk motifs drawn from his own experiences, but seeks inspiration from other sources as well. Hayden bemoans the fact that African American poetry is often treated as sociological writing instead of as literature, and notes a continuation of the literary ghetto that African American writing has long been consigned to. Works discussed include Words in the Morningtime, Full Moon, Selected Poems, How I Write, and Kaleidoscope. Works read include A Ballad of Remembrance, Those Winter Sundays, Night Death in Mississippi, Electrical Storm, Belsen, Day of Liberation, Sub Specie Aeternitatis, and Frederick Douglass.https://digitalcommons.brockport.edu/writers_videos/1038/thumbnail.jp

Global analysis of seasonal changes in trematode infection levels reveals weak and variable link to temperature

Seasonal changes in environmental conditions drive phenology, i.e., the annual timing of biological events ranging from the individual to the ecosystem. Phenological patterns and successional abundance cycles have been particularly well studied in temperate freshwater systems, showing strong and predictable synchrony with seasonal changes. However, seasonal successional changes in the abundance of parasites or their infection levels in aquatic hosts have not yet been shown to follow universal patterns. Here, using a compilation of several hundred estimates of spring-to-summer changes in infection by trematodes in their intermediate and defnitive hosts, spanning multiple species and habitats, we test for general patterns of seasonal (temperature) driven changes in infection levels. The data include almost as many decreases in infection levels from spring to summer as there are increases, across diferent host types. Our results reveal that the magnitude of the springto-summer change in temperature had a weak positive efect on the concurrent change in prevalence of infection in frst intermediate hosts, but no efect on the change in prevalence or abundance of infection in second intermediate or defnitive hosts. This was true across habitat types and host taxa, indicating no universal efect of seasonal temperature increase on trematode infections. This surprising variation across systems suggests a predominance of idiosyncratic and species-specifc responses in trematode infection levels, at odds with any clear phenological or successional pattern. We discuss possible reasons for the minimal and variable efect of seasonal temperature regimes, and emphasise the challenges this poses for predicting ecosystem responses to future climate change

GRADIENTE LATITUDINAL DE DIVERSIDAD PARASITARIA: LLENANDO EL VACÍO ENTRE LAS ÁREAS TEMPLADAS Y TROPICALES

Although the latitudinal gradient in species richness is one of the clearest global patterns of biodiversity, evidenceto date suggests that it either does not apply to parasites, or that if it does then the relationship is weak. In this short review, I use a large database including information from 950 surveys of helminth parasite diversity in vertebrate host populations to show that there is no latitudinal gradient in parasite species richness among bird or mammal hosts, and a weak one among fish hosts going against the general trend: fish from temperate latitudes tend to harbour more helminth species than those from the tropics. However, analyses of that database also show that several disparities between temperate and tropical parasite surveys can underlie the above finding. First, surveys of parasite diversity are accumulating at a much higher rate in temperate areas than in the tropics. Second, the overall level of parasitological knowledge per host species is generally higher for temperate vertebrates than for tropical ones. Third, the taxonomic resolution achieved per survey is also generally higher for temperate vertebrates than for tropical ones. Data from temperate and tropical regions are therefore not truly comparable at present, and it may be premature to attempt any large-scale test of the latitudinal diversity gradient hypothesis, or to accept the conclusions of previous studies attempting such a test.Aunque el gradiente latitudinal de riqueza específica es uno de los patrones globales de biodiversidad más evidentes, sin embargo, hasta la fecha, o bien no se ajusta para el caso de los parásitos, o si ocurre, la relación es débil. En esta breve revisión, utilizo una amplia base de datos con información sobre 950 estudios de diversidad de parásitos helmintos en poblaciones de vertebrados (aves, mamíferos y peces) para demostrar que no existe un gradiente latitudinal de la riqueza específica de parásitos entre aves o mamíferos; y que sí existe una débil relación en el caso de los peces, siendo ésta contraria la tendencia general. Es decir, los peces de latitudes templadas tienden a albergar más especies de helmintos que los de los trópicos. Sin embargo, estos análisis también muestran ciertas discrepancias entre los estudios parasitológicos de zonas templadas y tropicales que subyacen a los resultados obtenidos. En primer lugar, la tasa de elaboración de estudios sobre diversidad parasitaria en áreas templadas es mucho mayor que en áreas tropicales. En segundo lugar, el conocimiento global parasitológico a nivel del hospedador es generalmente mayor para los vertebrados de zonas templadas. Y en tercer lugar, la resolución taxonómica alcanzada en cada estudio, también es generalmente mayor en hospedadores de las zonas templadas que de las tropicales. Por lo tanto, los estudios de las regiones templadas y tropicales no son del todo comparables por el momento, es por ello que quizás sea prematuro, intentar comprobar a gran escala la hipótesis del gradiente latitudinal de diversidad, así como, el aceptar las conclusiones de estudios previos que han intentado comprobarla

Mapping autonomous system's router level topology in IPv6

The core of the Internet is composed of many independent and mutually exclusive collections of routers, called Autonomous Systems, which are responsible for moving traffic between communicating end-systems, or hosts, regardless of the relative location of those hosts. The complexity of the internal composition of these autonomous systems is such that accurate documentation of their topology, reference to as mapping, is difficult and prone to error. Developing automated support for this effort remains an area of active research, the potential benefit of which is the ability to actively monitor the health of the Internet across these autonomous systems making it possible to identify critical infrastructure chokepoints before their failure adversely impacts the network or national security. The Internet is in the process of transitioning to a new version of the Internet Protocol, the fundamental protocol that melds the heterogeneous networks worldwide into a single cooperative whole. Tools, techniques, and tactics developed for the current version, IPv4, may hold promise for adaptation to support the new version, IPv6. This thesis explores several of the IPv4 techniques that hold promise for adaptation and provides an implementation as a proof-of-concept.http://archive.org/details/mappingutonomous109453412US Air Force (USAF) author.Approved for public release; distribution is unlimited.Approved for public release; distribution is unlimited

Large-scale patterns in trematode richness and infection levels in marine crustacean hosts

Little is known about the patterns of variation in parasitism in marine hosts. Trematodes, the dominant parasites in intertidal systems, are transmitted from their first intermediate hosts (snails) to a range of second intermediate hosts, including crustaceans. Using published studies of trematode infections in crustacean hosts, we investigated general patterns of variation in trematode species richness and infection levels (i.e. percentage of hosts infected and mean number of individual parasites per host). Since the production and release of infective stages in snails is strongly temperature dependent, we also investigated a potential decrease in trematode infection levels with increasing latitude (as a proxy for decreasing temperature). Trematode species richness in the crustacean hosts was generally low (mostly 1 or 2), and infection levels were moderate. However, there were differences among taxa in some groups, particularly among brachyuran crabs, which showed significantly higher values than in other groups. For amphipods, which were the only well-studied group across a large range of latitudes, we found negative correlations between latitude and the trematode species richness or measures of infection level considered here. These relationships persisted after correction of the potentially confounding effects of sampling effort, host body size and host generic identity (as a control for phylogenetic influences). We discuss these findings in light of environmental mediation of parasite transmission, in particular with respect to the probably fundamental role of temperature in driving the output of trematode infective stages in marine systems

Open Access Journals in Communication Studies: Indexing in Five Commercial Databases

This study investigates the degree of indexing of gold Open Access (OA) journals within the field of communication studies in five major commercial bibliographical databases commonly subscribed by academic libraries and used by researchers and students. Results of the study indicate that 32 percent of the 147 gold OA journals identified were indexed in the five target databases. The communication studies databases provided the most complete indexing, while among the multidisciplinary databases, Scopus provided more coverage compared to Academic Search Complete, and Web of Science

Consultations sur l'enseignement supérieur : projet de création du Conseil des collèges du Québec et de la Commission mixte de l'enseignement supérieur et suggestions de modifications au Règlement sur le régime des études collégiales

Comprend des références bibliographique