1,721,037 research outputs found
Cut costs or invest more…Today’s tough economic questions. What are they and what is the new math?
No full textLoula, Tim; Dritz, Steve; Holtkamp, Derald; Pollmann, Steve. (2008). Cut costs or invest more…Today’s tough economic questions. What are they and what is the new math?. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/140248
Proposed modifications to porcine reproductive and respiratory syndrome virus herd classification
Full text linkA standardized system for classifying the porcine reproductive and respiratory syndrome virus (PRRSV) status of swine herds is necessary for communication between veterinarians and producers. The 2011 classification system has been widely adopted by producers and veterinarians worldwide. In 2018, a working group met to revisit the system and make recommendations for changes. The most significant modification was to the classification of positive unstable and positive stable breeding herds. Recommended diagnostic protocols for promotion of herds to each status were modified and recommended diagnostic protocols to maintain a status were added. The growing pig classification for PRRSV was also modified.This article is published as Holtkamp, Derald J., Montserrat Torremorell, Cesar A. Corzo, Daniel CL Linhares, Marcelo N. Almeida, Paul Yeske, Dale D. Polson et al. "Proposed modifications to porcine reproductive and respiratory syndrome virus herd classification." Journal of Swine Health and Production 29, no. 5 (2021): 261-270. Copyright 2021 American Association of Swine Veterinarians. Posted with permission
Efficacy of an accelerated hydrogen peroxide disinfectant to inactivate porcine epidemic diarrhea virus in swine feces on metal surfaces
Full text linkIn May of 2013, porcine epidemic diarrhea virus (PEDV) was detected in swine for the first time in North America. It spread rapidly, in part due to contaminated livestock trailers. The objective of this study was to test the efficacy of an accelerated hydrogen peroxide disinfectant for inactivating PEDV in the presence of feces on metal surfaces, such as those found in livestock trailers. Three-week-old barrows were inoculated intragastrically with 5 mL of PEDV-negative feces for the negative control, 5 mL of untreated PEDV-positive feces for the positive control, and 5 mL or 10 mL of PEDV-positive feces that was subjected to treatment with a 1:16 or 1:32 concentrations of accelerated hydrogen peroxide disinfectant for a contact time of 30 min at 20°C. These pigs served as a bioassay to determine the infectivity of virus following treatment. Rectal swabs collected from the inoculated pigs on days 3 and 7 post-inoculation were tested by using PEDV-specific real-time reverse transcription polymerase chain reaction and the proportion of pigs in each group that became infected with PEDV was assessed. None of the pigs used for the bioassay in the 4 treatment groups and the negative control group became infected with PEDV, which was significantly different from the positive control group (P This article is published as Holtkamp, Derald J., Jacqueline Myers, Paul R. Thomas, Locke A. Karriker, Alejandro Ramirez, Jianqiang Zhang, and Chong Wang. "Efficacy of an accelerated hydrogen peroxide disinfectant to inactivate porcine epidemic diarrhea virus in swine feces on metal surfaces." Canadian Journal of Veterinary Research 81, no. 2 (2017): 100-107. Posted with permission.</p
Assessment of temperature and holding times to inactivate PRRSV and PEDV on contaminated surfaces commonly found in supply entry rooms in swine farms
Full text linkFomites can be responsible for virus introduction in swine farms, which highlights the importance of implementing practices such as cleaning and disinfecting, using ultraviolet C light chambers or applying combinations of time and temperature to minimize the probability of virus introduction.
The objective of the study was to assess the efficacy of different combinations of temperatures and holding times to inactivate PRRSV and PEDV on cardboard and diamond plate aluminum, surfaces that are commonly found at supply entry rooms in swine farms.
An experimental study was conducted to assess the effect of time and temperature on two PRRSV strains and PEDV inactivation on cardboard and diamond plate aluminum. A total of 2 negative controls and 144 treatments with PRRSV MN 184, PRRSV 144 L1C Variant and PEDV were subjected to four different temperatures (20ºC, 30ºC, 40ºC, and 50ºC), and six time-settings (15 minutes, 60 minutes, 6 hours, 12 hours, 24 hours, and 36 hours). Virus titration followed by immunofluorescent staining were implemented after the virus recovery, and the cytopathic effect was observed.
The time that it took for the virus to stop being detected, Weibull curves were calculated. Virus was detected at 20ºC after 36 hours, after 15 minutes and after 60 minutes, virus was not detected on aluminum surfaces at 50ºC. The results from the least-squared means suggest that the minimum time that surfaces should be held to stop getting virus detection at 30ºC was 24 hours, at 40ºC was 12 hours and at 50ºC was 6 hours, and that aluminum surfaces take longer to reach the desired temperature
Farm-Level Evaluation of Planting Flexibility Proposals for the 1990 Farm Bill, Effects on Use of Corn Rootworm Insecticides and Nitrogen
No full textSince the 1985 Food Security Act (1985 FSA), increased concern for environmental and health risks associated with the use of chemicals in U.S. agriculture has changed the focus of legislative debate. One of the major responses to these concerns has been discussion of ways to give farmers greater flexibility in planting. Those proposing more flexibility promote it as a means of encouraging crop rotations and other alternatives to intensive chemical use. This study investigates the effectiveness of such provisions for (1) shifting rotations and (2) reducing applications of corn rootworm insecticide and nitrogen on a case-study Iowa farm. A specialized version of the Comprehensive Economic and Environmental Policy Evaluation System (CEEPES), developed at the Center for Agricultural and Rural Development (CARD), was utilized for the empirical assessment.</p
Lumber Futures, Price Expectations, and Short-run Production Adjustments in The Softwood Lumber Industry
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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