159 research outputs found

    Special relationships: Anglo-American affinities and antagonisms 1854-1936

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    This collection of essays by leading scholars of American literature and culture has emerged out of recent debates on the historical, geographical, symbolic, and cultural significance of the Atlantic, as well as new work in the area of Transatlantic Studies. In a series of fascinating essays the authors have produced diverse and innovative interventions in the field of Anglo-American literary relations. The authors discussed range from Gertrude Stein to Alfred North Whitehead, Charlotte Perkins Gilman to Sarah Grand, Henry James to George Eliot, Elizabeth Stoddard to Charlotte Bronte, Mark Twain to Walter Scott through to Djuna Barnes and Evelyn Waugh. Subjects discussed include Scottish-American literary relations, the Atlanticist dimension of Spiritualism, American interventions in the debate about Highland clearances, American slavery and British pastoralism

    Assessment of blackfly (Diptera : Simuliidae) problem status and potential biological control agents along the Vaal and Orange Rivers in South Africa

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    Blackflies (Diptera: Simuliidae) are major pests in the livestock and labour-intensive farming systems along the major rivers in South Africa. At present, blackflies are controlled with the larvicide Bacillus thuringienses var. israelensis (B.t.i.). As part of establishing an environmentally friendly and cost-effective Integrated Pest Management (IPM) program against blackflies, investigations were initiated to support the present blackfly-control strategy in South Africa. Emphasis was placed on potential predators and parasites of the blackflies’ aquatic stages. Questionnaires were presented to livestock farmers along the Vaal and Orange Rivers to determine public views concerning blackfly annoyance. Furthermore, blackfly populations at thirteen sites along the Orange River, twelve along the Vaal River and one site along each of two tributaries to the Vaal River, namely the Riet and Harts Rivers, were monitored seasonally for one year. The abundance of the aquatic stages of blackflies and potential predators on stones and vegetation in the river was determined using the 10-point visual ranking system of Palmer (1994) and the South African Scoring system (SASS 5), respectively. The abundance of algae as well as other environmental factors, namely water flow, water temperature and turbidity, were also monitored. Farmers who were contacted along both the Vaal and Orange rivers indicated that they experience severe blackfly problems during the summer months and that the majority of farmers were not aware of any products available that could protect their animals against blackfly attacks. The farmers also indicated that they were willing to be involved in blackfly research to improve this situation. Blackfly larvae and pupae were found in high abundance in both the Vaal and Orange Rivers. Simulium chutteri was the most abundant species in the Orange River and S. adersi in the Vaal River. In both the Vaal and Orange Rivers there was no significant correlation between immature blackfly abundance and water flow and turbidity. Water temperature also played a role in the seasonal build-up of blackflies in the winter months. The three most abundant algae classes were Bacillariophyceae, Chlorophyceae and Cyanophyceae. Cyanophyceae was the only algae group that had a negative correlation with blackfly immature abundance in the Orange River; this was not statistically significant. There were no negative correlations in the Vaal River. In both the Vaal and Orange rivers, blackflies were infected with Mermithidae nematodes and Microspora protozoans. In the Vaal River, the infection prevalence in natural conditions was the highest for Microspora and in the Orange River the highest for Mermithidae. The most important families of blackfly predators identified were Hydropsychidae and Gyrinidae. Hydropsychidae was the only family recorded in high abundance but this predator had no effect on abundance of immature blackfly. Gyrinidae gave a negative correlation with immature blackfly abundance; however, this was not significant. The biological control agents identified in this research need to be evaluated further for use in an IPM approach with the current control system, B.t.i. CopyrightDissertation (MSc)--University of Pretoria, 2008.Veterinary Tropical Diseasesunrestricte

    Survey of blackfly (Diptera : Simuliidae) annoyance levels and abundance along the Vaal and Orange Rivers, South Africa

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    Blackflies (Diptera: Simuliidae) are pests in the livestock and labour-intensive farming systems along the major rivers in South Africa. Since 1995, blackflies have been controlled in the Orange River with the larvicide Bacillus thuringienses var. israelensis (Bti). During 2006–2007, the views of livestock farmers concerning blackfly annoyance were determined by means of questionnaires. The results of the questionnaires were substantiated by seasonal abundance surveys of the sub-adult stages of blackflies, conducted in 2007 at 13 sites in the Orange River and 11 sites in the Vaal River. More than half (52%) of the 39 participating farmers along the Orange River and 79% of the 52 participating farmers along the Vaal River stated that they experienced severe blackfly problems. The majority of farmers were unaware of the availability of products that could be used to protect their animals against blackfly attacks and were willing to be involved in blackfly research. High numbers of blackfly sub-adult stages found in both rivers supported the high annoyance levels reported by the respondents. Simulium chutteri, Simulium damnosum s.l., Simulium hargreavesi, Simulium adersi and Simulium alcocki were identified at Christiana and Delportshoop on the Vaal River, whilst S. chutteri, S. damnosum s.l., S. adersi, S. alcocki and Simulium gariepense were identified at Marksdrift and Ses Bridge on the Orange River. Despite the extensive control of blackflies, farmers still experience problems and this contention is supported by surveys conducted along the rivers.C.J.d.B. (Onderstepoort Veterinary Institute) wrote the manuscript as fulfilment for an MSc degree within the Department of Veterinary Tropical Diseases at the University of Pretoria, for which K.K.G. (University of Pretoria) was the study supervisor.The Agricultural Research Council – Onderstepoort Veterinary Institute (ARC – OVI) and the Department of Agriculture (Directorate of Land Use and Soil Management).http://www.jsava.co.zahttp://upetd.up.ac.za/thesis/available/etd-07302009-154218/ab201

    The Catalytic Site Atlas 2.0: cataloging catalytic sites and residues identified in enzymes.

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    Understanding which are the catalytic residues in an enzyme and what function they perform is crucial to many biology studies, particularly those leading to new therapeutics and enzyme design. The original version of the Catalytic Site Atlas (CSA) (http://www.ebi.ac.uk/thornton-srv/databases/CSA) published in 2004, which catalogs the residues involved in enzyme catalysis in experimentally determined protein structures, had only 177 curated entries and employed a simplistic approach to expanding these annotations to homologous enzyme structures. Here we present a new version of the CSA (CSA 2.0), which greatly expands the number of both curated (968) and automatically annotated catalytic sites in enzyme structures, utilizing a new method for annotation transfer. The curated entries are used, along with the variation in residue type from the sequence comparison, to generate 3D templates of the catalytic sites, which in turn can be used to find catalytic sites in new structures. To ease the transfer of CSA annotations to other resources a new ontology has been developed: the Enzyme Mechanism Ontology, which has permitted the transfer of annotations to Mechanism, Annotation and Classification in Enzymes (MACiE) and UniProt Knowledge Base (UniProtKB) resources. The CSA database schema has been re-designed and both the CSA data and search capabilities are presented in a new modern web interface

    Bovine trypanosomosis prevalence at the edge of Hluhluwe-iMfolozi Park, KwaZulu-Natal, South Africa

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    The northern KwaZulu-Natal (NKZN) region of South Africa is the southern limit of the African tsetse belt. Entomological information on Glossina brevipalpis and Glossina austeni was generated following the outbreak of trypanosomosis in cattle in 1990. However, these data have not been supported by parallel studies on epidemiology of the disease and therefore there has been no control policy in place. This study presented the first intensive investigations to address the epidemiology of trypanosomosis in NKZN. Tsetse abundance, trypanosome herd average prevalence (HAP), herd average anaemia (HAA) and herd average packed cell volume (HA-PCV) were investigated at three communal diptanks located at the edge of HluhluweiMfolozi Park by monthly sampling from June 2006 - November 2007. Seasonal trypanosome surveys were conducted at seven other communal diptanks. Glossina brevipalpis prevalence was high at two of the diptanks, Mvutshini and Ekuphindisweni, but low at Ocilwane, whilst G. austeni was only collected from Mvutshini. This high and low tsetse challenge presented different disease scenarios. Cattle at Mvutshini and Ekuphindisweni had the highest HAP of 12.3% and 8.9% respectively, both significantly different (p = 0.001) from the HAP obtained from cattle at Ocilwane (2.9%). These two cattle herds also had the highest HAA, 27.7% and 33.4% respectively, whilst cattle at Ocilwane had the lowest, 11.1% (p = 0.001). Conversely, cattle at Ocilwane had the highest HA-PCV, ranging between 29.0% and 32.0%, whilst cattle at Mvutshini and Ekuphindisweni had the lowest HA-PCV (24.0% - 29.0%). By combining the data from the three diptanks (1318 observations), 62.0% of the infected cattle were found anaemic, compared to 20.0% in the uninfected group. Trypanosome seasonal surveys showed that cattle at all the seven diptanks were infected with trypanosomes; mean HAP, HAA and HA-PCV of 10.2%, 46.6% and 23.7%, respectively. This study generated information on the epidemiological factors related to the wide spread of trypanosome-infected cattle and tsetse flies. Trypanosomosis is a disease of economic importance impacting the livelihood of resource-poor farmers in NKZN.http://www.ojvr.orgtm201

    Evaluation of radiation sensitivity and mating performance of Glossina brevipalpis males

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    BACKGROUND : Area-wide integrated pest management strategies that include a sterile insect technique component have been successfully used to eradicate tsetse fly populations in the past. To ensure the success of the sterile insect technique, the released males must be adequately sterile and be able to compete with their native counterparts in the wild. METHODOLOGY/PRINCIPAL FINDINGS : In the present study the radiation sensitivity of colonised Glossina brevipalpis Newstead (Diptera; Glossinidae) males, treated either as adults or pupae, was assessed. The mating performance of the irradiated G. brevipalpis males was assessed in walk-in field cages. Glossina brevipalpis adults and pupae were highly sensitive to irradiation, and a dose of 40 Gy and 80 Gy induced 93% and 99% sterility respectively in untreated females that mated with males irradiated as adults. When 37 to 41 day old pupae were exposed to a dose of 40 Gy, more than 97% sterility was induced in untreated females that mated with males derived from irradiated pupae. Males treated as adults with a dose up to 80 Gy were able to compete successfully with untreated fertile males for untreated females in walk-in field cages. CONCLUSIONS/SIGNIFICANCE : The data emanating from this field cage study indicates that, sterile male flies derived from the colony of G. brevipalpis maintained at the Agricultural Research Council-Onderstepoort Veterinary Institute in South Africa are potential good candidates for a campaign that includes a sterile insect technique component. This would need to be confirmed by open field studies.The Research was done in collaboration with the Joint Food and Agriculture Organization/ International Atomic Energy Agency Division of Nuclear Techniques in Food and Agriculture under the coordinated research project 17753/R0.http://www.plosntds.orgam2017Veterinary Tropical Disease

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Transcriptional Profiling of Non-Small Cell Lung Cancer Cells with Activating EGFR Somatic Mutations

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    Activating somatic mutations in epidermal growth factor receptor (EGFR) confer unique biologic features to non-small cell lung cancer (NSCLC) cells, but the transcriptional mediators of EGFR in this subgroup of NSCLC have not been fully elucidated.Here we used genetic and pharmacologic approaches to elucidate the transcriptomes of NSCLC cell lines. We transcriptionally profiled a panel of EGFR-mutant and -wild-type NSCLC cell lines cultured in the presence or absence of an EGFR tyrosine kinase inhibitor. Hierarchical analysis revealed that the cell lines segregated on the basis of EGFR mutational status (mutant versus wild-type), and expression signatures were identified by supervised analysis that distinguished the cell lines based on mutational status (wild-type versus mutant) and type of mutation (L858R versus Delta746-750). Using an EGFR mutation-specific expression signature as a probe, we mined the gene expression profiles of two independent cohorts of NSCLC patients and found the signature in a subset. EGFR tyrosine kinase inhibitor treatment regulated the expression of multiple genes, and pharmacologic inhibition of the protein products of two of them (PTGS2 and EphA2) inhibited anchorage-independent growth in EGFR-mutant NSCLC cells.We have elucidated genes not previously associated with EGFR-mutant NSCLC, two of which enhanced the clonogenicity of these cells, distinguishing these mediators from others previously shown to maintain cell survival. These findings have potential clinical relevance given the availability of pharmacologic tools to inhibit the protein products of these genes

    Using Strategic Movement to Calibrate a Neural Compass: A Spiking Network for Tracking Head Direction in Rats and Robots

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    The head direction (HD) system in mammals contains neurons that fire to represent the direction the animal is facing in its environment. The ability of these cells to reliably track head direction even after the removal of external sensory cues implies that the HD system is calibrated to function effectively using just internal (proprioceptive and vestibular) inputs. Rat pups and other infant mammals display stereotypical warm-up movements prior to locomotion in novel environments, and similar warm-up movements are seen in adult mammals with certain brain lesion-induced motor impairments. In this study we propose that synaptic learning mechanisms, in conjunction with appropriate movement strategies based on warm-up movements, can calibrate the HD system so that it functions effectively even in darkness. To examine the link between physical embodiment and neural control, and to determine that the system is robust to real-world phenomena, we implemented the synaptic mechanisms in a spiking neural network and tested it on a mobile robot platform. Results show that the combination of the synaptic learning mechanisms and warm-up movements are able to reliably calibrate the HD system so that it accurately tracks real-world head direction, and that calibration breaks down in systematic ways if certain movements are omitted. This work confirms that targeted, embodied behaviour can be used to calibrate neural systems, demonstrates that ‘grounding’ of modelled biological processes in the real world can reveal underlying functional principles (supporting the importance of robotics to biology), and proposes a functional role for stereotypical behaviours seen in infant mammals and those animals with certain motor deficits. We conjecture that these calibration principles may extend to the calibration of other neural systems involved in motion tracking and the representation of space, such as grid cells in entorhinal cortex
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