Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Bayesian Techniques (1)
- Beet webworms (1)
- Binomial data (1)
- Bioavailability (1)
- Bioequivalence (1)
-
- Breedxdiet interaction (1)
- Completely Randomized Design (1)
- Component analysis (1)
- Covariance adjustment (1)
- Coverage (1)
- Crossover design (1)
- Equivalence Testing (1)
- Genetic Algorithm (1)
- Horvitz-Thompson estimation (1)
- LSMEAN (1)
- Least Squares Estimation (1)
- Non-parametric factorial analysis (1)
- Observational factor (1)
- Partially adjusted mean (1)
- Pharmacokinetics (1)
- Power (1)
- Principal components (1)
- Repeated measures (1)
- Simulation (1)
- Sitter bootstrapping (1)
- Split-plot Design (1)
- Variance component (1)
Articles 1 - 30 of 43
Full-Text Articles in Entire DC Network
Double-Crested Cormorant And Ring-Billed Gull Damage Management On Lake Champlain: Are Basin-Wide Objectives Achievable?, Richard Chipman, Dennis Slate, Larry Garland, David Capen
Double-Crested Cormorant And Ring-Billed Gull Damage Management On Lake Champlain: Are Basin-Wide Objectives Achievable?, Richard Chipman, Dennis Slate, Larry Garland, David Capen
Wildlife Damage Management Conference
Ring-billed gulls (Larus delewarensis) and double-crested cormorants (Phalacrocorx auritus) have nested on Lake Champlain since 1949 and 1982, respectively. Recent increases in cormorant nesting populations and pioneering activities of both species to previously uncolonized islands have resulted in impacts related to accumulation of bird guano and interspecific competition with less common species. Of primary concern are: decreases in wildlife and plant diversity on islands; reduced aesthetics and property values of island associated with the loss of trees; and predation or competition for nesting space with other species such as the state-endangered common tern (Sterna hirundo …
Wildlife Damage To Agricultural Crops In Pennsylvania: The Farmers' Perspective, Margaret C. Brittingham, Walter M. Tzilkowski, James M. Zeidler, Matthew J. Lovallo
Wildlife Damage To Agricultural Crops In Pennsylvania: The Farmers' Perspective, Margaret C. Brittingham, Walter M. Tzilkowski, James M. Zeidler, Matthew J. Lovallo
Wildlife Damage Management Conference
Agricultural damage by wildlife is a major concern for both agricultural and wildlife agencies at the state and federal level. Our objective was to estimate wildlife damage to agricultural crops on a statewide basis. We sent questionnaires to 4,958 farmers and 1,003 were returned after 2 mailings. Twenty-five percent of farmers responding to our survey rated the level of wildlife damage to their crops as severe or very severe, 46% as moderate, and 29% had none or very little. Mean levels of crop loss to wildlife ranged from 6% for wheat to 10% for corn grain, and white-tailed deer ( …
Development Of The Virginia Cooperative Coyote Control Program To Protect Livestock, Martin Lowney, John Houben, Phil Eggborn
Development Of The Virginia Cooperative Coyote Control Program To Protect Livestock, Martin Lowney, John Houben, Phil Eggborn
Wildlife Damage Management Conference
The Virginia Cooperative Coyote Control Program was created in 1990 to address increasing livestock losses to coyotes and the inability of producers to solve such problems themselves. The eastern coyote arrived in Virginia in the late 1970s or early 1980s. Lobbying efforts of agricultural groups, such as the Virginia Sheep Federation, helped create a cost-share program administered by the Virginia Department of Agriculture and Consumer Services (VDACS) and U.S. Department of Agriculture-Animal and Plant Health Inspection Service-Wildlife Services (USDA-APHIS-WS). The objective of the program was to educate producers about control methods and to alleviate damage by removing offending coyotes where …
Wildlife-Caused Losses For Catfish Producers In 1996, Alice P. Wywialowski
Wildlife-Caused Losses For Catfish Producers In 1996, Alice P. Wywialowski
Wildlife Damage Management Conference
In January 1997, the National Agricultural Statistics Service (NASS) surveyed catfish producers about wildlife-caused losses in 1996, Of the 1,465 catfish producers in 15 states surveyed, 1,008 (68.8%) agreed to complete the survey. Surveys were conducted primarily by telephone, but some producers received mail surveys. The response rated varied among states. The majority of catfish producers were in Mississippi (n=-300), followed by Alabama (n=163), and then Arkansas (n=117). The remaining states each had < 100 respondents. Data were analyzed for 6 regions, each with a sample size of > 100 respondents. Overall, 69% of catfish producers cited a wildlife-caused loss of catfish. Producers cited losses to wildlife most frequently in Mississippi (81%), followed by states adjoining …
Nesting Populations Of Double-Crested Cormorants, Great Blue Herons, And Great Egrets In The United States And Canada: Implications For Management, Jerrold L. Belant, Laura A. Tyson
Nesting Populations Of Double-Crested Cormorants, Great Blue Herons, And Great Egrets In The United States And Canada: Implications For Management, Jerrold L. Belant, Laura A. Tyson
Wildlife Damage Management Conference
Populations of piscivorous birds in North America are receiving increasing attention in the southeast United States because of depredations at aquaculture facilities. We obtained recent (most since 1994) estimates for the number of nesting double-crested cormorants (Phalacrocorax auritus), great blue herons (Ardea herodias), and great egrets (Casmerodius albus) in the United States (US) and Canada from published references and by conducting telephone interviews with state and provincial biologists. Using previously-published data, we also determined annual rates of change in the number of cormorants since about 1990. Estimates for minimum numbers of nesting pairs (minimum …
Development Of A Double-Crested Cormorant Damage Management Plan For The Southeastern United States, Keith J. Andrews, Pete Poulos, Charles Bo Sloan, Jerrold L. Belant, Paige G. Ross, Paul Debow
Development Of A Double-Crested Cormorant Damage Management Plan For The Southeastern United States, Keith J. Andrews, Pete Poulos, Charles Bo Sloan, Jerrold L. Belant, Paige G. Ross, Paul Debow
Wildlife Damage Management Conference
In response to needs within the aquaculture industry to alleviate increasing depredation by double-crested cormorants (Phalacrocorax auritus), the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, in conjunction with Federal, State, and Canadian wildlife and fisheries agencies, the aquaculture industry, and other wildlife professionals, is developing the framework for a comprehensive cormorant damage management program that uses an integrated wildlife damage management approach. This cooperative effort will produce a meaningful, mutually beneficial program that will reduce the effects of cormorants on aquaculture and sport and commercial fisheries, improve understanding of cormorant biology, and avert …
Electric Fencing Reduces Heron Predation At Northeastern Trout Hatcheries, Mark E. Tobin, James F. Glahn, Erica S. Rasmussen
Electric Fencing Reduces Heron Predation At Northeastern Trout Hatcheries, Mark E. Tobin, James F. Glahn, Erica S. Rasmussen
Wildlife Damage Management Conference
Great blue herons (Ardea herodius) are the most common avian predator at commercial trout hatcheries in the northeastern United States. We evaluated a 2-strand electric fence for excluding this species from raceways at 2 commercial trout hatcheries in central Pennsylvania. Fences consisted of high density polyethylene 400-lb strength tape supported by fiberglass posts and energized by either a battery-powered or a solar-powered fence charger. Labor and material for constructing the fences at the 2 sites averaged $1.32/m of raceway. Bird visitation at the 2 sites initially declined, but returned to pre-installation levels. However, bird use of raceways declined …
The Legal Roles And Responsibilities Of A Community Concerning Crop Depredation By White-Tailed Deer, Eric G. Darracq, Stephen R. Chapman
The Legal Roles And Responsibilities Of A Community Concerning Crop Depredation By White-Tailed Deer, Eric G. Darracq, Stephen R. Chapman
Wildlife Damage Management Conference
The interwoven issues of the legal roles and responsibilities that landowners (i.e., farmers, foresters, and hunters) and a state agency have to control deer densities in rural areas that directly affect crop depredation and various stakeholders will be addressed in this paper. Because unmanaged deer populations severely can damage agricultural crops, the financial cost of this deer damage is borne entirely by individual private landowners. The South Carolina Department of Natural Resources (SCDNR) is the regulatory state agency in South Carolina responsible for annually promulgating rules and regulations pertaining to white-tailed deer harvest by hunters. Even though deer are property …
Deer Damage Incurred By Homeowners During 1995 In Virginia, Ben C. West, James A. Parkhurst
Deer Damage Incurred By Homeowners During 1995 In Virginia, Ben C. West, James A. Parkhurst
Wildlife Damage Management Conference
Damage caused by white-tailed deer (Odocoileus virginianus) is a problem for some homeowners in Virginia. As part of a broader effort to evaluate the attitudes and perceptions of agricultural producers and homeowners toward deer damage in Virginia, a mail questionnaire was developed and implemented during the fall of 1996. The survey yielded 732 useable responses and, of those, 261 individuals indicated they were homeowners and grew at least one planting during 1995. Many homeowners (36%) indicated that deer caused damage to at least one of their plantings during 1995. Of those who had experienced damage, most (61%, n=57) …
Repellency Of Methyl Anthranilate To Captive Great Egrets, Michael L. Avery, John S. Humphrey, David G. Decker
Repellency Of Methyl Anthranilate To Captive Great Egrets, Michael L. Avery, John S. Humphrey, David G. Decker
Wildlife Damage Management Conference
Because effective deterrents are hard to find, it has been suggested that methyl anthranilate (MA) be applied to the surface of fish ponds to discourage bird predation. We conducted two short-term evaluations of a formulation for this use, ReJeX-iT TP-40. First, we assessed the response of tropical fish to TP-40 applications in small wading pools. After 15 minutes, all fish virtually were motionless at or near the bottom of the pool. Fish in the control pools actively swam and most were within 3 cm of the surface of the pool. No mortality occurred, and fish activity returned to almost normal …
Response From Cooperative Extension Personnel To Citizen Requests For Information About Wildlife, Shannon Thurston, Gary J. San Julian
Response From Cooperative Extension Personnel To Citizen Requests For Information About Wildlife, Shannon Thurston, Gary J. San Julian
Wildlife Damage Management Conference
With the increasing urbanization of rural areas, conflicts between homeowners and wildlife are becoming more common. County extension offices frequently receive telephone calls from individuals who are experiencing problems with wildlife. In most cases, extension staff provides assistance over the phone or by mail. However, there are no guidelines for the distribution of information nor is there training for extension personnel. Each county office collects and distributes information differently. Because there is no follow-up to inquiries, little is known about what the homeowners actually do or whether the problems were solved. With some wildlife species, there is a question of …
Using Ranks To Perform Exact And Estimated Exact Tests In Designed Experiments, Scott J. Richter, Mark E. Payton
Using Ranks To Perform Exact And Estimated Exact Tests In Designed Experiments, Scott J. Richter, Mark E. Payton
Conference on Applied Statistics in Agriculture
A procedure is studied that uses rank transformed data to perform exact and estimated exact tests which is an alternative to the commonly used F-ratio test procedure. First, a common parametric test statistic is computed using rank transformed data, where two methods of ranking - ranks taken of the original observations, and ranks taken after aligning the observations - are studied. Significance is then determined using either the exact permutation distribution of the statistic or an estimate of this distribution based on a random sample of all possible permutations. Simulation studies compare the performance of this method to both the …
Testing Variance Components Using The Glm And Mixed Procedures Of Sas®, Ron Mcnew, Andy Mauromoustakos
Testing Variance Components Using The Glm And Mixed Procedures Of Sas®, Ron Mcnew, Andy Mauromoustakos
Conference on Applied Statistics in Agriculture
The test of a variance component in random and mixed normal linear models can be done using the F statistic from the analysis of variance or the Wald statistic which is the ratio of the variance component estimate to its estimated standard error. These are the methods used in the GLM and MIXED procedures of SAS®. We show that these two tests can give different results on the same data. For the one-way random model, the one-sided Wald test on the among group variance component can never be significant at the 0.05 probability level when the number of levels of …
The Statistical Analysis Of Active Control Equivalence Studies, Armando Garsd, Susana F. Delfino
The Statistical Analysis Of Active Control Equivalence Studies, Armando Garsd, Susana F. Delfino
Conference on Applied Statistics in Agriculture
In experimental work, the notion of equivalence falls short of the idea of equality. Thus, the effects of two treatments, while not identical, may still be regarded as equivalent if their difference is negligible in a certain sense. This simple distinction raises not only technical difficulties, since of necessity it results in special statistical procedures, but also deeper conceptual issues, since one has to ask why two treatments should be equivalent but not equal, more specifically, whether their being merely equivalent has any bearing on the practical questions posed by the data. In this paper we present examples, drawn from …
The Analysis Of The Two-Period Repeated Measurements Crossover Design With Application To A Forestry Problem, Armando Garsd, Maria C. Fabrizio, Maria V. López
The Analysis Of The Two-Period Repeated Measurements Crossover Design With Application To A Forestry Problem, Armando Garsd, Maria C. Fabrizio, Maria V. López
Conference on Applied Statistics in Agriculture
The two-period repeated measurements crossover design is not often used in agricultural studies. It is, however, an attractive model, involving the confluence of two powerful statistical ideas, treatment crossover and repeated measurements on the same experimental unit. This paper presents one approach for the statistical analysis of such design based on the work of Wallenstein and Fisher (1977). It is shown how the data may be transformed so that it can be analyzed under the framework of a completely randomized repeated measurements design. We formalize the analysis in the context of a forestry experiment conducted on poplar trees (Populus SP.), …
The Use Of Inverse Theory On An Ill-Posed Environmental Composite Sampling Problem, V. A. Lancaster, S. Keller-Mcnulty
The Use Of Inverse Theory On An Ill-Posed Environmental Composite Sampling Problem, V. A. Lancaster, S. Keller-Mcnulty
Conference on Applied Statistics in Agriculture
As an alternative to retesting, the use of inverse theory techniques is proposed to resolve the lack of information inherent in composite sampling methods. This paper evaluates the feasibility of combining composite sampling with the inverse theory technique of linear regularization on an environmental site characterization investigation. Federal legislation has mandated the cleanup of hazardous waste sites, creating the need to characterize these sites for various chemical constituents. An abundance of samples, high measurement costs, and limited budgets create the appeal of compositing samples. We propose that the number of costly laboratory analyses can be reduced by combining composite sampling …
Bootstrap Confidence Intervals From Adaptive Sampling Of An Insect Population, Jeffrey S. Pontius, Mary C. Christman
Bootstrap Confidence Intervals From Adaptive Sampling Of An Insect Population, Jeffrey S. Pontius, Mary C. Christman
Conference on Applied Statistics in Agriculture
We construct 90% normal, percentile, and bias-corrected and accelerated confidence intervals using a finite population bootstrapping algorithm based on adaptive sampling in an agroecosystem. We evaluate the interval estimates based on sampling simulations of a spatially arranged population of plots that contain counts of beet webworms and based on an adaptive condition that generates small networks. The sampling distributions of the original sample estimates and of the bootstrap estimates were generally similar and symmetric. The simulation coverages were from 84% to 90% and similar under any of the sample sizes and any of the three confidence interval types. This study …
Some Experiences With Neural Networks, Lynda L. Ballou, Dallas E. Johnson
Some Experiences With Neural Networks, Lynda L. Ballou, Dallas E. Johnson
Conference on Applied Statistics in Agriculture
This paper gives a brief overview of artificial neural networks which may be used to model data similar to the kind where one usually considers regression models. Many practitioners believe that neural networks perform better than regression models for prediction purposes. Some simulations were performed using three different neural net programs, namely Braincel, Ripley's S+ program, and Nychka's S+ program. These simulations reveal some interesting aspects of neural net programs which should be of interest to anyone considering the use of neural net programs to model continuous data.
Some Factors Limiting The Use Of Generalized Linear Models In Agricultural Research, Walter W. Stroup
Some Factors Limiting The Use Of Generalized Linear Models In Agricultural Research, Walter W. Stroup
Conference on Applied Statistics in Agriculture
The generalized linear model (GLM) is a "hot" topic in statistics. Numerous research articles on GLM's appear in each edition of all major journals in statistics. GLM's are the subject of substantial numbers of presentations at most statistics conferences. Despite the high level of interest and research activity within the statistics community, GLM's are not widely used, with some exceptions, by biological scientists in the statistical analysis of their research data. Why? Reasons include 1) many statisticians are not comfortable with GLM's, 2) the biological research community is not familiar with GLM's, and 3) there is little in introductory statistics …
How Good Are Spatial Glm's? A Simulation Study, Roger G. Collins, Walter W. Stroup, Stephen D. Kachman
How Good Are Spatial Glm's? A Simulation Study, Roger G. Collins, Walter W. Stroup, Stephen D. Kachman
Conference on Applied Statistics in Agriculture
An area of increasing interest to agricultural and ecological researchers is the analysis of spatially correlated non-normal data. A generalized linear model(GLM) accounting for spatial covariance was presented by Gotway and Stroup (1997). Their method included approximate inference based on asymptotic distributions. A simulation study was conducted to assess the small sample behavior of their proposed estimates and test statistics. This study suggests that the spatial GLM yields unbiased estimates of treatment means and differences for binomial data, that the spatial GLM improves precision, as measured by MSE, and that the approximate F-statistic is acceptable for hypothesis testing.
Alternative Analyses Of Crossover Designs With More Than Two Periods, Carla L. Goad, Dallas E. Johnson
Alternative Analyses Of Crossover Designs With More Than Two Periods, Carla L. Goad, Dallas E. Johnson
Conference on Applied Statistics in Agriculture
A crossover experiment is a special form of a repeated measures experiment. An appropriate analysis of a repeated measures experiment depends on the form of the varian-cecovariance matrix of the repeated measures. Certain forms of this matrix yield valid analysis of variance F -tests while other forms invalidate these tests. In a crossover experiment where analysis of variance tests are invalid, two alternative tests of a linear contrast of the parameters are proposed. In addition to these approximate t-tests, three alternative methods for testing for equal treatment effects and equal carryover effects are proposed. A simulation study is conducted to …
Bioavailability And Cv Component Comparison In A Crossover, Zhiming Wang, Vince A. Uthoff
Bioavailability And Cv Component Comparison In A Crossover, Zhiming Wang, Vince A. Uthoff
Conference on Applied Statistics in Agriculture
Two medication formulations are compared using noncompartmental pharmacokinetic (PK) variables. However, more than the ratio of mean effects is of interest. A difference in formulation coeficients of varication (CV), within- or between-subject, is sought. The experimental design chosen is a 2 sequence crossover design of the form ABBA and BAAB, where A and B are two medication formulations. A mixed linear model is defined that contains random effects for subjects and for subject by formulation interactions. The model has fixed effects for the average formulation effects and period effects. The 2 formulations are assumed to have different error terms. The …
Equivalence Testing In Agriculture Experiments, Brian J. Fergen
Equivalence Testing In Agriculture Experiments, Brian J. Fergen
Conference on Applied Statistics in Agriculture
Equivalence testing is a relatively new area of research in statistics. It's 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 …
Covariance Adjustment In Studies Involving Observational Factors Or Covariates Influenced By Treatments, O. B. Allen, I. B. Mandell, J. W. Wilton, L. B. Buchanan-Smith
Covariance Adjustment In Studies Involving Observational Factors Or Covariates Influenced By Treatments, O. B. Allen, I. B. Mandell, J. W. Wilton, L. B. Buchanan-Smith
Conference on Applied Statistics in Agriculture
We extend the definition of adjusted treatment means in the analysis of covariance to deal with the case where some of the covariates are influenced by treatments or where some of the factors are observational. In these cases, comparison of treatment means adjusted to a common value of the covariate may be inappropriate. Partially adjusted means are defined and it is shown that special cases include the usual adjusted means (adjusted to a common value for each of the covariates) and unadjusted means. In fact, in a multifactorial experiment, one can, by appropriate choice of adjustment, compare adjusted means for …
Comparing The Use Of Block And Covariate Information In Analysis Of Variance, James R. Schwenke
Comparing The Use Of Block And Covariate Information In Analysis Of Variance, James R. Schwenke
Conference on Applied Statistics in Agriculture
Of primary concern in the statistical analysis of the results of an experiment is to quantify the mean response to treatment and to accurately quantify the experimentation error variance. The traditional approach to account for nuisance sources of variation or a heterogeneous population is to group or block the population (or sample) into homogeneous groups with respect to a concomitant variable. A blocking term then is included in the statistical analysis. Alternatively, concomitant variables can be used as covariate information in a statistical analysis. A statistical analysis incorporating blocks assumes that the magnitude of difference in treatment response is equal …
Analysis Of A Midwest Farmer Survey Of Pest Infestation, Susanne Aref
Analysis Of A Midwest Farmer Survey Of Pest Infestation, Susanne Aref
Conference on Applied Statistics in Agriculture
A survey of farmers rating the severity of crop pest infestation in their fields was conducted in the Midwest in 1992. The purpose of the present study was to detennine summary variables of the pest infestation ratings and the effect of region, soil type, and tillage on these summary variables. The pests were in the following six categories: perennial and annual weeds, insects and diseases of com (Zea mays L.) and insects and diseases of soybean (Glycine max (L.) MerritT). Categorical models were used to analyze individual pest ratings. A non-parametric method, the Sheirer-Ray-Hare extension of the Kruskal-Wallis test …
Empirical Estimates Of Power For Binomial Data With Mixed Models, R. K. Splan, L. D. Van Vleck, H. D. Hafs
Empirical Estimates Of Power For Binomial Data With Mixed Models, R. K. Splan, L. D. Van Vleck, H. D. Hafs
Conference on Applied Statistics in Agriculture
Observations on return to estrus from anestrus postpartum beef cows were used as the basis for a simulation study to develop a method to determine numbers of locations and animals per treatment per location to achieve a specified power of test. Estimates of among location and total variance were obtained by REML from the data set and then used to generate simulated data for the binomial trait. Each combination of several pre-determined factors was replicated 1000 times. Pre-determined factors were number of locations, number of animals per treatment per location, desired detectable difference due to treatment, alpha-probability level and ratio …
Alternative Procedures For Estimation Of Nonlinear Regression Parameters, William J. Price, Bahman Shafii
Alternative Procedures For Estimation Of Nonlinear Regression Parameters, William J. Price, Bahman Shafii
Conference on Applied Statistics in Agriculture
Biological research data are often represented using nonlinear model specifications that lend themselves to the testing of relevant hypotheses concerning the model parameters. This is typically achieved with classical nonlinear least squares techniques such as Gauss-Newton or Levenberg-Marquardt which allow for both the estimation and inference phases of the analysis. Under some circumstances, however, sensitivity to data or model specifications may lead these methods to fail convergence tests or exhibit nonlinearity in the parameter estimates, which will in turn limit the usefulness of inferential results. In such cases, other estimation methods may present a means of avoiding these problems while …
Confidence Intervals For Heritability In A Mixed Linear Model, Brent D. Burch, Hari K. Iyer
Confidence Intervals For Heritability In A Mixed Linear Model, Brent D. Burch, Hari K. Iyer
Conference on Applied Statistics in Agriculture
A family of procedures is given to construct confidence intervals for the heritability of a trait in a mixed linear model. The procedures are applicable for constructing confidence intervals for a ratio of variance components in a mixed linear model having two sources of variation. The resulting intervals are evaluated in terms of expected length. The investigator may select the best confidence interval procedure from the family of procedures based on the interval( s) having short expected length. Confidence intervals for loineye data using bulls from a Red Angus seed stock herd will be presented.
Using Prior Knowledge Of The Intraclass Correlation To Increase The Power Of Tests For Treatment Means, Marjorie E. Bond, James J. Higgins
Using Prior Knowledge Of The Intraclass Correlation To Increase The Power Of Tests For Treatment Means, Marjorie E. Bond, James J. Higgins
Conference on Applied Statistics in Agriculture
It is common in agricultural research to have experimental units that consist of multiple observational units. For instance, treatments may be applied to pens of animals, pens being the experimental units, while weights are measured on individual animals, the observational units. If there are a small number of experimental units, the power of statistical tests for treatment effects can be small regardless of the number of observational units. We show that it is possible to increase the power of such statistical tests by taking advantage of prior knowledge of the intraclass correlation. Our assertion is that such prior knowledge is …