3,486 research outputs found
Moldy Feed - Good or Bad
Molds develop in feed in response to the nourishment they get from the feed. They develop only in the presence of air and as the result of favorable moisture conditions, which must be above a relative water vapor pressure equivalence of 65 to 70%. They develop very slowly at near-freezing temperatures and rapidly as temperatures rise. By enzyme action, they convert the energy components of the feed (carbohydrates, fats and proteins) into their own body structure with loss to the air mainly of metabolically-generated heat, water, carbon dioxide, ammonia and of fragments of their body as spores. They may or may not produce chemicals toxic to animals, which will remain with the mold in the feed. Their overall effect is to lower the total energy content of the feed, replacing some of it with their own body structure and by-products
Shape of the phosphorus 32 beta energy spectrum
The shape of the beta energy spectrum of P32 was determined by making a least squares fit of the experimental data. This was compared with the shape expected when interference between matrix elements of different orders of forbiddenness is assumed
Laboratory Efficacy of Chemical Repellents for Reducing Blackbird Damage in Rice and Sunflower Crops
Nonlethal alternatives are needed to manage blackbird (Icterids) damage to rice and sunflower production in the United States. We evaluated 4 registered fungicides on rice seeds (i.e., Allegiance® FL, Thiram 42-S, Trilex®, and Vitavax® 200 preplant seed treatments) and 2 foliar pesticides on sunflower seeds (CobaltTM insecticide and Flock Buster bird repellent) as candidate blackbird repellents. Red-winged blackbirds (Agelaius phoeniceus) preferred untreated rice relative to rice treated with Thiram (P \u3c 0.001) and Vitavax (P \u3c 0.001), and untreated sunflower relative to sunflower treated with Cobalt (P \u3c 0.001). Blackbirds preferred untreated sunflower relative to sunflower treated with Flock Buster repellent on day 1 of a 4-day preference test (P \u3c 0.001). We observed no difference in consumption of treated versus untreated rice during the Allegiance preference test (P = 0.928), and blackbirds preferred rice treated with Trilex relative to untreated rice (P = 0.003). Although repellency was positively related to tested concentrations of Thiram (P = 0.010), Trilex (P = 0.026), and Vitavax (P \u3c 0.001), maximum repellency was \u3c50% during our concentration-response tests of these seed treatments. Repellency was also positively related to tested concentrations of Cobalt (P \u3c 0.001), and we observed \u3e80% repellency of sunflower treated with Cobalt at ≥50% of the label rate. We observed no concentration-response relationship for the Allegiance seed treatment (P = 0.341) and Flock Buster repellent (P = 0.952). We recommend implementation of supplemental field studies to compare laboratory efficacy, repellency, and chemical residues of effective avian repellents throughout periods of needed crop protection
Recent Investigations at 15Ed23: Historic and Cultural Resources in a Disturbed Cave Environment
The Effect of European Starlings and Ambient Air Temperature on \u3cem\u3eSalmonella enterica\u3c/em\u3e Contamination within Cattle Feed Bunks
European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings
The effect of European starlings and ambient air temperature on \u3ci\u3eSalmonella enterica\u3c/i\u3e contamination within cattle feed bunks
European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings
The effect of European starlings and ambient air temperature on \u3ci\u3eSalmonella enterica\u3c/i\u3e contamination within cattle feed bunks
European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings
Efficacy Of European Starling Control To Reduce Salmonella Enterica Contamination In A Concentrated Animal Feeding Operation In The Texas Panhandle
Background: European starlings (Sturnus vulgaris) are an invasive bird species known to cause damage to plant and animal agriculture. New evidence suggests starlings may also contribute to the maintenance and spread of diseases within livestock facilities. Identifying and mitigating the risk pathways that contribute to disease in livestock is necessary to reduce production losses and contamination of human food products. To better understand the impact starlings have on disease transmission to cattle we assessed the efficacy of starling control as a tool to reduce Salmonella enterica within a concentrated animal feeding operation. We matched a large facility, slated for operational control using DRC-1339 (3-chloro-4-methylaniline hydrochloride, also 3-chloro ptoluidine hydrochloride, 3-chloro-4-methylaniline), with a comparable reference facility that was not controlling birds. In both facilities, we sampled cattle feed, cattle water and cattle feces for S. enterica before and after starling control operations. Results: Within the starling-controlled CAFO, detections of S. enterica contamination disappeared from feed bunks and substantially declined within water troughs following starling control operations. Within the reference facility, detections of S. enterica contamination increased substantially within feed bunks and water troughs. Starling control was not observed to reduce prevalence of S. enterica in the cattle herd. Following starling control operations, herd prevalence of S. enterica increased on the reference facility but herd prevalence of S. enterica on the starling-controlled CAFO stayed at pretreatment levels. Conclusions: Within the starling-controlled facility detections of S. enterica disappeared from feed bunks and substantially declined within water troughs following control operations. Since cattle feed and water are obvious routes for the ingestion of S. enterica, starling control shows promise as a tool to help livestock producers manage disease. Yet, we do not believe starling control should be used as a stand alone tool to reduce S. enterica infections. Rather starling control could be used as part of a comprehensive disease management plan for concentrated animal feeding operations
An Exploratory Investigation on the Invasiveness of Environmental Modeling Frameworks
Environmental modeling frameworks provide an array of useful features that model developers can harness when implementing models. Each framework differs in how it provides features to a model developer via its Application Programming Interface (API). Environmental modelers harness framework features by calling and interfacing with the framework API. As modelers write model code, they make framework-specific function calls and use framework specific data types for achieving the functionality of the model. As a result of this development approach, model code becomes coupled with and dependent on a specific modeling framework. Coupling to a specific framework makes migration to other frameworks and reuse of the code outside the original framework more difficult. This complicates collaboration between model developers wishing to share model code that ma y have been developed in a variety of languages and frameworks. This paper provides initial results of an exploratory investigation on the invasiveness of environmental modeling frameworks. Invasiveness is defined as th e coupling between application (i.e., model) and framework code used to implement the model. By comparing the implementation of an environmental model across several modeling frameworks, we aim to better understand the consequences of framework design. How frameworks present functionality to modelers through APIs can lead to consequences with respect to model development, model maintenance, reuse of model code, and ultimately collaboration among model developers. By measuring framework invasiveness, we hope to provide environmental modeling framework developers and environmental modelers with valuable in formation to assist in future development efforts. Eight implementations (six framework-based) of Thornthwaite, a simple water balance model, were made in a variety of environmental modeling frameworks and languages. A set of software metrics were proposed and applied to measure invasiveness between model implementation code and framework code. The metrics produced a rank ordering of invasiveness for the framework-based implementations of Thornthwaite. We compared model invasiveness results with several popular software metrics including size in lines of code (LOC), cyclomatic complexity, and object oriented coupling. To investigate software quality implications of framework invasiveness we checked for relationships between the Chidamber and Kemerer (1994) object oriented software metrics and our framework invasiveness measures. For the six framework-based implementations of Thornthwaite we found a five-fold variation in code size (LOC). We observed up to a seven-fold variation in total cyclomatic complexity, and a two to three-fold variation in object oriented coupling. For the model implementations we found that total size, total complexity, and total coupling all had a significant positive correlation. The raw count version of our invasiveness measures correlated with application size (LOC), total cyclomatic complexity, total efferent coupling (fan out) and total afferent coupling (fan in). Large size, complexity, and high levels of coupling between units (classes, modules) in a software system are often cited in software engineering as causes of high maintenance costs due to poor understandability and flexibility of the code. This study provides initial results but further investigation is desired to evaluate the utility of our invasiveness measurement approach as well as the software quality implications of framework invasiveness
Environmental Modeling Framework Invasiveness: Analysis and Implications
Environmental modeling frameworks support scientific model development by providing an Application Programming Interface (API) which model developers use to implement models. This paper presents results of an investigation on the framework invasiveness of environmental modeling frameworks. Invasiveness is defined as the quantity of dependencies between model code and the modeling framework. This research investigates relationships between invasiveness and the quality of modeling code. Additionally, we investigate the relationship between invasiveness and two common framework designs (lightweight vs. heavyweight). Five metrics to measure framework invasiveness were proposed and applied to measure invasiveness between model and framework code of several implementations of Thornthwaite and the Precipitation-Runoff Modeling System (PRMS), two hydrological models. Framework invasiveness measurements were compared with existing software metrics including size (lines of code), cyclomatic complexity, and object-oriented coupling with generally positive correlations being found. We found that models with lower framework invasiveness tended to be smaller, less complex, and have lower coupling. In addition, the lightweight framework implementations of the Thornthwaite and PRMS models were less invasive than the heavyweight framework model implementations. Our initial results suggest that framework invasiveness is undesirable for model code quality and that lightweight frameworks may help reduce invasiveness
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