432 research outputs found
County-Level Impacts of Rail Line Abandonments: A Kansas Case Study
This article describes the use of econometric panel data techniques to estimate the effects of rail line abandonments at the county level. The article presents the economic theory that indicates how abandonments will affect local communities. Data were collected on line abandonments and several economic measures for counties in Kansas. Panel data estimation techniques were used to provide estimates of the effects for rural, urban and metropolitan counties. Results indicate that abandonments produce an initial period of economic growth that may be temporary for some counties. Results also indicate that any adverse impacts appear with a time lag of a few years
Modeling the impact of vaccination control strategies on a foot and mouth disease outbreak in the Central United States
The central United States (U.S.) has a large livestock population including cattle, swine, sheep and goats. Simulation models were developed to assess the impact of livestock herd types and vaccination on foot and mouth disease (FMD) outbreaks using the North American Animal Disease Spread Model. In this study, potential FMD virus outbreaks in the central region of the U.S. were simulated to compare different vaccination strategies to a depopulation only scenario. Based on data from the U.S. Department of Agriculture National Agricultural Statistics Service, a simulated population of 151,620 livestock operations characterized by latitude and longitude, production type, and herd size was generated. For the simulations, a single 17,000 head feedlot was selected as the initial latently infected herd in an otherwise susceptible population. Direct and indirect contact rates between herds were based on survey data of livestock producers in Kansas and Colorado. Control methods included ring vaccination around infected herds. Feedlots ≥3000 head were either the only production type that was vaccinated or were assigned the highest vaccination priority. Simulated vaccination scenarios included low and high vaccine capacity, vaccination zones of 10 km or 50 km around detected infected premises, and vaccination trigger of 10 or 100 detected infected herds. Probability of transmission following indirect contact, movement controls and contact rate parameters were considered uncertain and so were the subjects of sensitivity analysis. All vaccination scenarios decreased number of herds depopulated but not all decreased outbreak duration. Increased size of the vaccination zone during an outbreak decreased the length of the outbreak and number of herds destroyed. Increased size of the vaccination zone primarily resulted in vaccinating feedlots ≥3000 head across a larger area. Increasing the vaccination capacity had a smaller impact on the outbreak and may not be feasible if vaccine production and delivery is limited. The ability to vaccinate all the production types surrounding an infected herd did not appear as beneficial as priority vaccination of feedlot production types that have high numbers of indirect contacts. Outbreak duration, number of herds depopulated and the effectiveness of vaccination were sensitive to indirect contact transmission probability and movement restrictions. The results of this study will provide information about the impacts of disease control protocols which may be useful in choosing the optimal control methods to meet the goals of rapid effective control and eradication
Spatial-Temporal Dynamics of High-Resolution Animal Social Networks: What Can We Learn from Domestic Animals?
Recent studies of animal social networks have significantly increased our
understanding of animal behavior, social interactions, and many important
ecological and epidemiological processes. However, most of the studies are at
low temporal and spatial resolution due to the difficulty in recording accurate
contact information. Domestic animals such as cattle have social behavior and
serve as an excellent study system because their position can be explicitly and
continuously tracked, allowing their social networks to be accurately
constructed. We used radio-frequency tags to accurately track cattle position
and analyze high-resolution cattle social networks. We tested the hypothesis of
temporal stationarity and spatial homogeneity in these high-resolution networks
and demonstrated substantial spatial-temporal heterogeneity during different
daily time periods (feeding and non-feeding) and in different areas of the pen
(grain bunk, water trough, hay bunk, and other general pen area). The social
network structure is analyzed using global network characteristics (network
density, exponential random graph model structure), subgroup clustering
(modularity), triadic property (transitivity), and dyadic interactions
(correlation coefficient from a quadratic assignment procedure). Cattle tend to
have the strongest and most consistent contacts with others around the hay bunk
during the feeding time. These results cannot be determined from data at lower
spatial (aggregated at entire pen level) or temporal (aggregated at daily
level) resolution. These results reveal new insights for real-time animal
social network structure dynamics, providing more accurate descriptions that
allow more accurate modeling of multiple (both direct and indirect) disease
transmission pathways.Comment: 4 figure
Temporal-spatial heterogeneity in animal-environment contact: Implications for the exposure and transmission of pathogens
Contact structure, a critical driver of infectious disease transmission, is not completely understood and characterized for environmentally transmitted pathogens. In this study, we assessed the effects of temporal and spatial heterogeneity in animal contact structures on the dynamics of environmentally transmitted pathogens. We used real-time animal position data to describe contact between animals and specific environmental areas used for feeding and watering calves. The generated contact structure varied across days and among animals. We integrated animal and environmental heterogeneity into an agent-based simulation model for Escherichia coli O157 environmental transmission in cattle to simulate four different scenarios with different environmental bacteria concentrations at different areas. The simulation results suggest heterogeneity in environmental contact structure among cattle influences pathogen prevalence and exposure associated with each environment. Our findings suggest that interventions that target environmental areas, even relatively small areas, with high bacterial concentration can result in effective mitigation of environmentally transmitted pathogens.
doi:10.1038/srep0311
The moral experience of illness and its impact on normalisation: Examples from narratives with Punjabi women living with rheumatoid arthritis in the UK
The moral component of living with illness has been neglected in analyses of long-term illness experiences. This paper attempts to fill this gap by exploring the role of the moral experience of illness in mediating the ability of those living with a long-term condition (LTC) to normalise. This is explored through an empirical study of women of Punjabi origin living with rheumatoid arthritis (RA) in the UK. Sixteen informants were recruited through three hospitals in UK cities and interviews conducted and analysed using a Grounded Theory approach. The intersection between moral experience and normalisation, within the broader context of ethnic, gender and socio-economic influences, was evident in the following: disruption of a core lived value (the centrality of family duty), beliefs about illness causation affecting informants’ ‘moral career’, and perceived discrimination in the workplace. The data illustrate the importance of considering an ethnic community’s specific values and beliefs when understanding differences in adapting to LTCs and changing identities
Appendices For: Dewatering Well Assessment for the Highway Drainage System at Four Sites in the East St. Louis Area, Illinois (Phase 2)
published or submitted for publicationis peer reviewedOpe
Dewatering Well Assessment for the Highway Drainage System at Four Sites in the East St. Louis Area, Illinois (Phase 2)
published or submitted for publicationis peer reviewedOpe
Public ground-water supplies in DuPage county
Cover title."ISWS/BUL-60(32)/86."Enumeration continues from preceding title
Ehrlichia chaffeensis Infection in the Reservoir Host (White-Tailed Deer) and in an Incidental Host (Dog) Is Impacted by Its Prior Growth in Macrophage and Tick Cell Environments
Citation: Nair, A. D. S., Cheng, C., Jaworski, D. C., Willard, L. H., Sanderson, M. W., & Ganta, R. R. (2014). Ehrlichia chaffeensis Infection in the Reservoir Host (White-Tailed Deer) and in an Incidental Host (Dog) Is Impacted by Its Prior Growth in Macrophage and Tick Cell Environments. PLOS ONE, 9(10), e109056. https://doi.org/10.1371/journal.pone.0109056Ehrlichia chaffeensis, transmitted from Amblyomma americanum ticks, causes human monocytic ehrlichiosis. It also infects white-tailed deer, dogs and several other vertebrates. Deer are its reservoir hosts, while humans and dogs are incidental hosts. E. chaffeensis protein expression is influenced by its growth in macrophages and tick cells. We report here infection progression in deer or dogs infected intravenously with macrophage- or tick cell-grown E. chaffeensis or by tick transmission in deer. Deer and dogs developed mild fever and persistent rickettsemia; the infection was detected more frequently in the blood of infected animals with macrophage inoculum compared to tick cell inoculum or tick transmission. Tick cell inoculum and tick transmission caused a drop in tick infection acquisition rates compared to infection rates in ticks fed on deer receiving macrophage inoculum. Independent of deer or dogs, IgG antibody response was higher in animals receiving macrophage inoculum against macrophage-derived Ehrlichia antigens, while it was significantly lower in the same animals against tick cell-derived Ehrlichia antigens. Deer infected with tick cell inoculum and tick transmission caused a higher antibody response to tick cell cultured bacterial antigens compared to the antibody response for macrophage cultured antigens for the same animals. The data demonstrate that the host cell-specific E. chaffeensis protein expression influences rickettsemia in a host and its acquisition by ticks. The data also reveal that tick cell-derived inoculum is similar to tick transmission with reduced rickettsemia, IgG response and tick acquisition of E. chaffeensis
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