861 research outputs found

    Working Effectively with People who are Blind or Visually Impaired

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    This brochure on peoples who are blind or visually impaired and The Americans with Disabilities Act (ADA) is one of a series on human resources practices and workplace accommodations for persons with disabilities edited by Susanne M. Bruyère, Ph.D., CRC, SPHR, Director, Program on Employment and Disability, School of Industrial and Labor Relations – Extension Division, Cornell University

    Working Effectively with People who are Blind or Visually Impaired

    Get PDF
    This brochure on peoples who are blind or visually impaired and The Americans with Disabilities Act (ADA) is one of a series on human resources practices and workplace accommodations for persons with disabilities edited by Susanne M. Bruyère, Ph.D., CRC, SPHR, Director, Program on Employment and Disability, School of Industrial and Labor Relations – Extension Division, Cornell University. Cornell University was funded in the early 1990’s by the U.S. Department of Education National Institute on Disability and Rehabilitation Research as a National Materials Development Project on the employment provisions (Title I) of the ADA (Grant #H133D10155). These updates, and the development of new brochures, have been funded by Cornell’s Program on Employment and Disability

    Do older adults want playgrounds?

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    Current research indicates that the use of playgrounds by older adults would provide many health benefits. The paper explores the attitudes and barriers faced by older UK adults towards the concept of using playgrounds for exercise. Interviews and discussion groups were held involving in total 125 older adults between the ages of 58 and 100. The views of equipment manufacturers and those with a professional interest in playground provision were also sought using interviews and postal questionnaires. Whilst the older adults sampled were currently making very little use of playground equipment, there was notable interest in the concept of playground use. Considerable social barriers to playground use were however highlighted. Placing playgrounds in a controlled supervised environment and partaking in playground use with grandchildren were seen as the most popular ways of overcoming such barriers. Even when functionally inclusive equipment is available it is important that all social barriers are overcome, if older adults are to use playgrounds

    Bottom-Up Control of Parasites

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    Parasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free-living organisms. Bottom-up theory predicts that resource enhancement will increase the abundance and biomass of free-living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape-level experiment in which salt marshes (60,000 m2 each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod, Orchestia grillus, and the density and biomass of its trematode parasite, Levinseniella byrdi. Strikingly, L. byrdiprevalence increased over time, up to 13 times higher in nutrient-enriched marshes (30%) relative to the mean prevalence in reference marshes (2.4%). The biomass density of infected amphipods was, on average, 11 times higher in nutrient-enriched marshes (1.1 kg/ha) than in reference marshes (0.1 kg/ha), when pooling across all years. Orchestia grillus biomass comprises 67% of the arthropod community biomass; thus, nutrient enrichment elicits a substantial surge in parasitized biomass in the arthropod community. If our results are typical, they suggest that eutrophication can increase parasite abundance and biomass with chronic resource enhancement. Therefore, minimizing aquatic nutrient pollution may prevent outbreaks of parasites with aquatic hosts

    Reconstructing long-term ecological data from annual census returns: a test for observer bias in counts of bird populations on Skokholm 1928–2002

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    Long-term ecological data are essential for conservation and to monitor and evaluate the effects of environmental change. Bird populations have been routinely assessed on islands off the British coast for many years and here long term data for one such island, Skokholm, is evaluated for robustness in the light of some 20 changes in observers (wardens) on the island over nearly eight decades. It was found that the dataset was robust when compared to bootstrap data with no species showing significant changes in abundance in years when wardens changed. It is concluded that the breeding bird populations on Skokholm and other British offshore islands are an important scientific resource and that protocols should be enacted to ensure the archiving of records, the continuance of data collection using standardised protocols into the future, and the recognition of such long-term data for science in terms of an appropriate conservation designation

    'Beer used to belong to older men': drink and authority among the Nyakyusa of Tanzania

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    In her last major work on social change among the Nyakyusa of southwestern Tanzania, Monica Wilson returned to an argument about the changing role of beer drinking which had featured in her earlier writings (1963: 176, 1977: 92-3, 131). She suggested that the selling of locally made grain beer for cash, and its consumption in commercial clubs, had played a major role in altering relationships between young and old, and men and women. Generational separation had broken down: young men had lost respect for elder men and women had acquired a new economic autonomy founded on the cash income they earned from selling beer. Beer thus lay at the heart of a pattern of social change (1977: 186). This article examines changes in authority and the drinking of beer in Nyakyusa society from the 1890s-when written records become available-to the end of the twentieth century. It argues that patterns of deference and authority have suffered less dislocation than Wilson suggested and that-while locally made grain beer has been physically transformed, has disappeared from certain public rituals of well-being and has come increasingly into the cash market-its commoditisation has not necessarily empowered women, nor has it eliminated the role of beer in patterns of behaviour and discourse which sustain elder men's claims to authority

    Ecosystem engineers modulate exotic invasions in riparian plant communities by modifying hydrogeomorphic connectivity

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    Patterns of native and exotic plant species richness and cover were examined in relation with ecosystem engineer effects of pioneer vegetation within the Mediterranean gravel bed river Tech, South France. The floristic composition was characterized according to two distinct vegetation types corresponding to two habitats with contrasted conditions: (i) open and exposed alluvial bars dominated by herbaceous communities; and (ii) islands and river margins disconnected from annual hydrogeomorphic disturbances and covered by woody vegetation. A significant positive correlation between exotic and native plant species richness and cover was observed for both vegetation types. However, significant differences in native and exotic species richness and cover were found between these two vegetation types. Higher values of total species richness and Shannon diversity were attained within the herbaceous vegetation type than within the woody type. These differences are most likely related to changes in local exposure to hydrogeomorphic disturbances driven by woody engineer plant species and to vegetation succession. A lower exotic species cover within the woody vegetation type than within the herbaceous type suggested an increase of resistance to invasion by exotic species during the biogeomorphic succession. The engineer effects of woody vegetation through landform construction resulted in a decrease of alpha (a) diversity at the patch scale but, in parallel, caused an increase in gamma (g) diversity at the scale of the studied river segment. Our study corroborates recent investigations that support the theory of biotic acceptance of exotic species by native species at the local scale (generally <10 m2) within heterogeneous and disturbed environments. Furthermore, we suggest that in riparian contexts such as the River Tech exotic species trapp sediment at the same time as native species and thus contribute to the increase in ecosystem resistance during the biogeomorphic succession

    Decoupled diversity dynamics in green and brown webs during primary succession in a salt marsh

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    1.Terrestrial ecosystems are characterised by a strong functional connection between the green (plant-herbivore-based) and brown (detritus-detritivore-based) parts of the food web, which both develop over successional time. However, the interlinked changes in green and brown food web diversity patterns in relation to key ecosystem processes are rarely studied. 2.Here, we demonstrate changes in species richness, diversity and evenness over a wide range of invertebrate green and brown trophic groups during 100 years of primary succession in a salt marsh ecosystem, using a well-calibrated chronosequence. 3.We contrast two hypotheses on the relationship between green and brown food web diversity across succession: i) ‘coupled diversity hypothesis’, which predicts that all trophic groups covary similarly with the main drivers of successional ecosystem assembly versus ii) the ‘decoupled diversity hypothesis’, where green and brown trophic groups diversity respond to different drivers during succession. 4.We found that, while species richness for plants and invertebrate herbivores (green web groups) both peaked at intermediate productivity and successional age, the diversity of macro-detritivores, microarthropod microbivores and secondary consumers (brown web groups) continuously increased towards the latest successional stages. These results suggest that green web trophic groups are mainly driven by vegetation parameters, such as the amount of bare soil, vegetation biomass production, and vegetation height, while brown web trophic groups are mostly driven by the production and standing stock of dead organic material and soil development. 5.Our results show that plant diversity cannot simply be used as a proxy for the diversity of all other species groups that drive ecosystem functioning, as brown and green diversity components in our ecosystem responded differently to successional gradients

    The Ethics of Interpretation in Political Theory and Intellectual History

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    Scholars studying classic political texts face an important decision: Should these texts be read as artifacts of history or as sources for still-valid insights about politics today? Competing historical and “presentist” approaches to political thought do not have a methodological dispute—that is, a disagreement about the most effective scholarly means to an agreed-upon end. They instead have an ethical dispute about the respective value of competing activities that aim at different purposes. This article examines six ethical arguments, drawn primarily from the work of Quentin Skinner, in favor of the historical approach. It concludes that while both intellectual history and presentist theory are ethically justifiable, the best justification of the former enterprise is that it can help us achieve the purposes of the latter
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