76 research outputs found

    Causal Connections between Water Quality and Land Use in a Rural Tropical Island Watershed: Rural Tropical Island Watershed Analysis

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    We examined associations between riparian canopy cover, presence or absence of cattle, rainfall, solar radiation, month of year, dissolved oxygen, turbidity, salinity, and Enterococcus concentrations in riparian surface soils with Enterococcus geometric mean in-stream water concentrations at Waipā watershed on the north side of the Hawaiian island Kaua’i. Each 1% decrease in riparian canopy cover was associated with a 4.6 most probable number (MPN)/100 ml increase of the geometric mean of Enterococcus in stream water (P < 0.05). Each unit decrease in salinity (ppt) was associated with an increase of Enterococcus by 68.2 MPN/100 ml in-stream water geometric mean concentrations (P < 0.05). Month of year was also associated with increases in stream water Enterococcus geometric mean concentrations (P < 0.05). Reducing riparian canopy cover is associated with Enterococcus increases in stream water, suggesting that decreasing riparian vegetation density could increase fecal bacteria surface runoff

    Escherichia coli O157:H7 in Feral Swine near Spinach Fields and Cattle, Central California Coast1

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    We investigated involvement of feral swine in contamination of agricultural fields and surface waterways with Escherichia coli O157:H7 after a nationwide outbreak traced to bagged spinach from California. Isolates from feral swine, cattle, surface water, sediment, and soil at 1 ranch were matched to the outbreak strain

    Interactions with humans impose time constraints on urban-dwelling rhesus macaques (Macaca mulatta)

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    Time is a valuable but limited resource, and animals’ survival depends on their ability to carefully manage the amount of time they allocate to each daily activity. While existing research has examined the ecological factors affecting animals’ activity budgets, the impact of anthropogenic factors on urban dwelling animals’ time budgets remains understudied. Here we collected data through focal animal sampling from three groups of rhesus macaques in Northern India to examine whether interactions with humans decrease macaques’ resting and social time (time constraints hypothesis), or whether, by contrast, foraging on anthropogenic food, that is potentially high in calories, leads macaques to spend more time resting and in social interactions (free time hypothesis). We found that macaques who interacted more frequently with people spent significantly less time resting and grooming, supporting the time constraints hypothesis. We argue that these time constraints are likely caused by the unpredictability of human behavior.National Science Foundatio

    T.A. Ward

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    respectively). A combination of one habitat assessment and Proper Functioning Condition should be utilized to conduct a comprehensive assessment of riparian/stream health. Site characteristics, which were significantly associated with assessment outcomes included entrenchment ratio, substrate size, channel width to depth and slope. This presents a problem in that comparison of assessment outcomes across different streams and stream reaches are confounded by factors such as slope and substrate type, which may not always be indicative of riparian/stream health. The Rosgen Stream Morphology Classification system was used to successfully control for the effect of these site-specific effects on assessment outcome, allowing for comparison of riparian/stream health assessments across streams

    Seasonality in Human Zoonotic Enteric Diseases: A Systematic Review

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    BACKGROUND: Although seasonality is a defining characteristic of many infectious diseases, few studies have described and compared seasonal patterns across diseases globally, impeding our understanding of putative mechanisms. Here, we review seasonal patterns across five enteric zoonotic diseases: campylobacteriosis, salmonellosis, vero-cytotoxigenic Escherichia coli (VTEC), cryptosporidiosis and giardiasis in the context of two primary drivers of seasonality: (i) environmental effects on pathogen occurrence and pathogen-host associations and (ii) population characteristics/behaviour. METHODOLOGY/PRINCIPAL FINDINGS: We systematically reviewed published literature from 1960-2010, resulting in the review of 86 studies across the five diseases. The Gini coefficient compared temporal variations in incidence across diseases and the monthly seasonality index characterised timing of seasonal peaks. Consistent seasonal patterns across transnational boundaries, albeit with regional variations was observed. The bacterial diseases all had a distinct summer peak, with identical Gini values for campylobacteriosis and salmonellosis (0.22) and a higher index for VTEC (Gini  0.36). Cryptosporidiosis displayed a bi-modal peak with spring and summer highs and the most marked temporal variation (Gini = 0.39). Giardiasis showed a relatively small summer increase and was the least variable (Gini = 0.18). CONCLUSIONS/SIGNIFICANCE: Seasonal variation in enteric zoonotic diseases is ubiquitous, with regional variations highlighting complex environment-pathogen-host interactions. Results suggest that proximal environmental influences and host population dynamics, together with distal, longer-term climatic variability could have important direct and indirect consequences for future enteric disease risk. Additional understanding of the concerted influence of these factors on disease patterns may improve assessment and prediction of enteric disease burden in temperate, developed countries

    Rangeland Monitoring Series: Visual Assessment of Riparian Health

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    Guide to a standardized method for assessing the condition of riparian areas, for landowners, managers, and resource professionals. Color photos
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