EQUIVALENCE TESTING IN AGRICULTURE EXPERIMENTS

Equivalence testing is a relatively new area of research in statistics. It\u27s development has been motivated in large part by the need for statistical methods for determining if generic drugs are bioequivalent to their name brand counterparts. The application of equivalence testing methods to data resulting from experiments and surveys unrelated to drug development, and in particular agriculture-related experiments, is infrequent and possibly non-existent. These methods provide useful alternatives to the analysis methods currently being used. In this paper, an overview of the philosophy of equivalence testing and a review of equivalence testing methods are presented. Additionally, experimental situations for which equivalence testing would be appropriate are discussed. Examples that illustrate the application of the philosphy of equivalence testing to experimental designs commonly used in agriculture research are also presented

Selection of Pressure Equation for Preliminary Planing Hull Design Using Modified Analytical Hierarchy Process

In the early stages of design when data availability is limited, engineers often times rely upon experience and regression analysis to select the most suitable design equation among many competitive ones. This study presents an alternative that applies a modified Analytical Hierarchy Process (AHP) to select the most suitable design equation. The Analytical Hierarchy Process, a multi-criteria decision making method, has been utilized in the business and management world to collect and evaluate experts\u27 opinions in order to arrive at a final decision. The Analytical Hierarchy Process employed here will treat each of the design equations as an expert and allow the decision maker to evaluate and weight the opinions of the experts. Selecting an impact pressure equation among seven semi-empirical and three classification societies\u27 design equations for planing hull design is used as an example to facilitate the study presented in this dissertation. The criteria and their associated weights that make up the decision making hierarchy of the Analytical Hierarchy Process are first established, with which the overall weighting coefficients can be computed to rank the candidate design equations. A preview sensitivity analysis is applied to screen out unfavorable design equations. The Analytical Hierarchy Process is then applied to select the most suitable impact pressure equation for twenty planing hulls. Next, a post sensitivity analysis is applied to ensure the robustness of the decision process. The results of such selection are compared with those of full scale test data. The implemented Analytical Hierarchy Process accurately selects the optimal pressure equation for fifteen of the twenty test cases. While it fails to select the best pressure design equation for the other five cases, it does provide recommendations that can lead to the selection of the right design equation. This study has demonstrated that the Analytical Hierarchy Process holds potential to be effective not only in selecting a suitable pressure equation for planing hull design but also in finding the strengths and the weaknesses of each of the pressure equations under consideration

Employed Desistance: Identifying Best Employment-Focused Interventions and Practices for Gang Desistance

This study examined those employment-focused interventions (services, programming, mentorship, other supports) most effective in supporting an individual’s desistance from gang involvement. Utilizing a qualitative approach (interviews, document analysis and nonparticipant observation), this study engaged with individuals and organizations involved in the critical work of gang desistance to learn what makes their practices most effective. The criticality of gang desistance work lies in its efforts to address the thousands of lives continually lost each year as a result of gang-involvement and activity. Where gangs exist in cities, towns and communities across the country (and world, for that matter), the approaches of demonization, marginalization and suppression continue as the overwhelming response to gangs and gang activity. This study highlighted the individuals and organizations offering an alternative, employment-focused approach built on peer- and community-based efforts founded on inclusion and empowerment. Through the data collection, this study intended to identify and detail the practices of the research participants and why they are effective. Beginning with a review of available research within the field of gang desistance, an understanding of the evolving theories of the phenomenon of one desisting from gang involvement were explored, followed by an exploration of why individuals join gangs, the impacts of gang involvement, what prompts gang members to desist, and those interventions most supportive of this desistance. With an emphasis on service providers and leaders with the lived experience of gang desistance, as well as organizations dedicated to gang desistance work, the themes and evidence that emerged from the data collection provided deeper insights into how the process of desisting from gang involvement can be most effectively supported and realized. The outcome of this research pointed to several components of the work of gang desistance that make it most effective. These components focused on the desisting individual and the internal and external elements that both prompted and help maintained their desistance; the types of interventions most conducive to supporting a desisting individual––especially those focused on the individual’s identity desistance and self-efficacy; and, finally, those qualities of those service providers and organizations who provided these interventions and what made them impactful and effective. The findings of this study revealed that there are models, practices and other elements to support individuals toward effectively desisting from gang involvement. The findings also revealed the challenging and dynamic nature of the phenomenon of gang desistance––both for those desisting and those supporting them. Resulting from this nature of the work and the still developing field of gang desistance studies, these findings also offered areas of focus for future research toward a stronger understanding of the process of gang desistance, and, more importantly, the development and implementation of effective gang desistance concepts and practices

SIMULATION COMPARISON OF STATISTICAL METHODS USED IN ASSESSING VACCINE EFFICACY IN VETERINARY BIOLOGICS

In veterinary biologics, clinical studies conducted to support the licensure of a vaccine generally include a demonstration of efficacy in the species of interest. Typically, these studies are designed to assess a vaccine’s ability to prevent or mitigate clinical disease. Study designs utilize two or more treatment groups, and often incorporate blocking structure restrictions to accommodate animal housing or litter-related effects. When assessing a vaccine’s ability to prevent clinical disease, the prevented fraction (PF), a function of the group proportions of affected animals, is often utilized. Typically the sample size per treatment group is limited, and each block is represented by only a few experimental units per treatment group. Thus, it is a common occurrence for group proportion estimates to be 0 or 1 at the block level. Typical methods utilized in analyzing study data include generalized linear mixed model with delta method for confidence interval (GLMM), Cochran-Mantel-Haenszel (CMH) and Gart & Nam (GN). Through simulation, we compare the performance characteristics (power, bias, coverage) of these methods for a range of study designs, sample sizes and PF values, including an assessment of type 1 error rates. Simulation results suggest CMH generally performs well whereas the GN can perform poorly with regards to type 1 error. GLMM performance varies, depending on the simulated situation. Further, upon closer investigation of GN simulated results, it was determined that the method does not always result in a unique solution

Simulation Comparison of Methods to Estimate Confidence Intervals of the Mitigated Fraction

In the area of veterinary medicine, efficacy studies are conducted to support licensure of vaccines. Such studies are typically designed to assess a vaccine\u27s ability to prevent or mitigate clinical disease. For example, reduction of duration/severity of clinical signs or the severity of lung lesions are often considered as primary or secondary criteria of success. Studies designed to measure efficacy typically utilize two or more treatment groups and often use blocking structures to accommodate animal housing or litter related effects. When the criteria of interest are continuous or ordinal variables, as is the case with the above measurements, the mitigated fraction (MF) is often used to quantify a vaccine effect. One common approach involves determining the confidence interval for the MF using a bootstrap procedure. For data arising from studies with a blocking structure, there are two bootstrap procedures that are often used. The first resamples the blocks with replacement (randomized cluster bootstrap). The second resamples the blocks and the subjects within blocks, both with replacement (two-stage bootstrap). In addition to the bootstrap procedures, an asymptotic estimate of the variance of the MF can be calculated and used to construct a confidence interval. With three potential methods, it is of interest to determine coverage related to the associated intervals using study designs commonly used for in efficacy studies. In addition, coverage was assessed in situations with and without a treatment effect. Using parameter estimates obtained from the data in which lung lesions were measured, we conducted a simulation experiment estimating the MF and confidence interval using each method described above. The results from this simulation study suggest the bootstrap procedures perform poorly when no treatment effect is present, while the confidence interval estimated using the asymptotic variance performs well. However, none of the methods perform particularly well in the presence of a treatment effect

Infección urinaria como factor de riesgo para amenaza de parto pretèrmino en gestantes del Hospital de Chulucanas II-1, 2020

Con el objetivo de determinar la relación entre la infección urinaria como factor de riesgo y la amenaza de parto pretèrmino en gestantes del Hospital Chulucanas II- 1. 2020, se realizó un estudio con diseño no experimental, de nivel descriptivo correlacional de caso y control, con muestra de 70 (caso) y 70 (control) de mujeres cony sin amenaza de parto pre término. Los datos fueron recolectados con la ayuda de una ficha de investigación para luego ser procesados en tablas de doble entrada, para el análisis estadístico de los resultados e identificación de la existencia de la relación de las variables se usó la prueba Chi cuadrado con p < 0,05 para la significancia estadística y se calculó el OR, con su respectivo intervalo de confianza al 95%. Los resultados permiten concluir que del total de pacientes el 67% con amenaza de parto pretèrmino tuvo infección urinaria este se asoció la edad ( p valor = 0,032 ) y lugar de procedencia (p valor = 0,001); Además se evidenció que los antecedentes de ITU y urocultivo presentaron (pvalor = 0,001) y número de partos ( p valor = 0,032 ) tenían relación significativa con la infección urinaria como factor de riesgo para amenaza de parto pretèrmino en el Hospital de Chulucanas, 2020

Salmonella typhimurium fecal shedding following Salmonella choleraesuis-thyphimurium vaccination via drinking water and subsequent challenge

Salmonella typhimurium (ST) is a primary cause of enteritis and subclinical production losses in growing or finishing swine. Due to the zoonotic potential, intervention programs for ST have been established attempting to reduce carcass contamination. The objective of this study was to evaluate Salmonella fecal shedding of pigs vaccinated with a commercial, avirulent live culture (ALC) Salmonella Choleraesuis-Typhimurium vaccine when challenged with virulent ST

The effect of stripe domain structure on dynamic permeability of thin ferromagnetic films with out-of-plane uniaxial anisotropy

The permeability is calculated for a thin ferromagnetic film with the stripe domain structure and out-of-plane uniaxial magnetic anisotropy. Analytical expressions for the frequency dependence of components of permeability tensor are derived with the use of the Smit-Beljers method, with the thickness of domain walls and the domain wall motion being neglected. The effect of the domain width and the angle between the anisotropy axis and the film plane on the frequency dependence of the permeability is analyzed. General equations relating the static permeability components and the ferromagnetic resonance frequencies are found. The results of the approach are applied to the derivation of the constraint for the microwave permeability of thin ferromagnetic films. The analysis of the constraint as a function of the axis deviation angle, the domain aspect ratio and the damping parameter allows the conditions to be found for maximal microwave permeability. The results obtained may be useful in connection with the problem of developing high-permeable microwave magnetic materials.Comment: 22 pages, 6 figure

Thirty years of North American wind energy acceptance research: What have we learned?

Thirty years of North American research on public acceptance of wind energy has produced important insights, yet knowledge gaps remain. This review synthesizes the literature, revealing the following lessons learned. (1) North American support for wind has been consistently high. (2) The NIMBY explanation for resistance to wind development is invalid. (3) Socioeconomic impacts of wind development are strongly tied to acceptance. (4) Sound and visual impacts of wind facilities are strongly tied to annoyance and opposition, and ignoring these concerns can exacerbate conflict. (5) Environmental concerns matter, though less than other factors, and these concerns can both help and hinder wind development. (6) Issues of fairness, participation, and trust during the development process influence acceptance. (7) Distance from turbines affects other explanatory variables, but alone its influence is unclear. (8) Viewing opposition as something to be overcome prevents meaningful understandings and implementation of best practices. (9) Implementation of research findings into practice has been limited. The paper also identifies areas for future research on wind acceptance. With continued research efforts and a commitment toward implementing research findings into developer and policymaker practice, conflict and perceived injustices around proposed and existing wind energy facilities might be significantly lessened