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Full-Text Articles in Physical Sciences and Mathematics

Long-Term Trial Of An Inflatable Effigy Scare Device Or Repelling Cormorants From Catfish Ponds, Allen R. Stickley Jr., Junior O. King Oct 1993

Long-Term Trial Of An Inflatable Effigy Scare Device Or Repelling Cormorants From Catfish Ponds, Allen R. Stickley Jr., Junior O. King

Wildlife Damage Management Conference

Growing winter populations of double-crested cormorants (Phalacrocorax auritus) over the past decade have caused serious depredation problems for commercial channel catfish (lctalurus punctatus) growers in the Mississippi Delta (Stickley and Andrews 1989). Stickley et al. (1992) found that cormorants allowed to feed without hindrance took an average of 5 catfish fingerlings per foraging hour, but at times took as many as 28 fingerlings per hour. Obviously, growers have to repel these birds or suffer heavy losses where the cormorants are feeding on catfish fingerlings and not gizzard shad (Dorosoma cepedianum) as they at times …

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Rejex-It™Ag-36, A Potential Tool To Protect Seeds From Bird Depredation, Peter F. Vogt Oct 1993

Rejex-It™Ag-36, A Potential Tool To Protect Seeds From Bird Depredation, Peter F. Vogt

Wildlife Damage Management Conference

The ever increasing bird populations (e.g., Black birds, geese etc.) are known to cause considerable losses to agriculture. This problem has reached serious proportions for crops that are farmed on large tracts and are seeded by aerial application such as rice and canola. ReJeX-iT™AG-36, a non-toxic, biodegradable bird aversion formulation, derived from food grade ingredients, has been proven in pen tests and field trials to be effective as a seed treatment to prevent birds from eating the treated seeds. The product does not harm the seeds or the effected birds in any way, even if ingested; it just makes the …

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Can We Landscape To Accommodate Deer? The Tracy Estate Research Garden, Helen H. Heinrich, Susan Predl Oct 1993

Can We Landscape To Accommodate Deer? The Tracy Estate Research Garden, Helen H. Heinrich, Susan Predl

Wildlife Damage Management Conference

The landscape of New Jersey is remarkably rich in vegetation and open space, despite the state's reputation as the nation's most populous state. This landscape is increasingly the product of intense interaction between the white-tailed deer (Odocoileus virginianus) and both native and cultivated vegetation, particularly in suburban communities, where both the whitetail and the vegetation coexist in abundance. Nearly extirpated at the tum of the century due to over-hunting, the state's white-tailed deer population today exceeds 140,000 because habitat is ideal and hunting seasons are carefully regulated. In many instances, where landowners choose not to use hunting as …

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Evaluating The Gas Cartridge For Coyotes In Controlling Badgers, Craig A. Ramey Oct 1993

Evaluating The Gas Cartridge For Coyotes In Controlling Badgers, Craig A. Ramey

Wildlife Damage Management Conference

Efficacy investigations were conducted in Pampa, TX to evaluate the use of the "GAS CARTRIDGE FOR COYOTES: (Canis latrans) for controlling problem badgers (Taxidea taxus) in burrows. This coyote cartridge with two active ingredients (sodium nitrate and charcoal), produces high concentrations of carbon monoxide when burned and is effective in controlling coyotes in dens. Badgers were live-trapped, immobilized, and equipped with mortality-indicating radio transmitters prior to their release. Movements were monitored for a minimum of 12 days prior to each initial efficacy test and for at least 3 days in follow up tests for survivors. Only occupied …

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Impact Of Clearcut Size On White-Tailed Deer Use And Tree Regeneration, James W. Akins, Edwin D. Michael Oct 1993

Impact Of Clearcut Size On White-Tailed Deer Use And Tree Regeneration, James W. Akins, Edwin D. Michael

Wildlife Damage Management Conference

Northeastern forests have experienced regeneration delays and/or failures due to browsing by whitetailed deer (Odocoileus virginianus). Investigations were made in north-central West Virginia to determine if the size of clearcut is correlated with degree of deer browsing, regeneration of shrubs and trees, and percent ground cover by various herbaceous plants. Tree seedlings, woody shrubs, and herbaceous ground cover were recorded in September 1992 and August 1993 on 16, 1-year old clearcuts, ranging in size from 0.8 to 0.2 ha. Woody regeneration was categorized by species, origin, browsed or not, and vegetative height class on 25 systematically arranged sampling …

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Status And Management Of Vole Damage To Horticultural Plantings In North Carolina, Peter T. Bromley, William T. Sullivan Jr. Oct 1993

Status And Management Of Vole Damage To Horticultural Plantings In North Carolina, Peter T. Bromley, William T. Sullivan Jr.

Wildlife Damage Management Conference

A trapping study in 1979 indicated that voles (Microtus pennsylvanicus and M. pinetorum) were distributed widely in North Carolina. In 1991, Extension Agents with the North Carolina Cooperative Extension Service were surveyed to determine the distribution, nature and severity of vole damage to horticultural plantings, home orchards, and other plantings. Data from the statewide trapping survey and the poll of agents coincided to indicate that voles, particularly pine voles, caused damage from the mountains to the coast. Existing, legal control methods were judged grossly inadequate by agents. Pursuant to the surveys, the North Carolina Pesticide Board and the …

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Public Policy Education: An Important Wildlife Management Opportunity, Paul D. Curtis Oct 1993

Public Policy Education: An Important Wildlife Management Opportunity, Paul D. Curtis

Wildlife Damage Management Conference

Suburban wildlife management issues are generating heated debate between citizen organizations, elected public officials, and state wildlife management agencies. Decisions are being made by town and county officials which directly impact or supersede state authority for managing resident wildlife. As an example, I will focus this discussion on the white-tailed deer (Odocoileus virginianus) management controversy at Durand Eastman Park, in the greater Rochester metropolitan area, New York.

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Deer Damage In Tennessee: Landowner Perceptions And Attitudes, Michael M. King Oct 1993

Deer Damage In Tennessee: Landowner Perceptions And Attitudes, Michael M. King

Wildlife Damage Management Conference

White-tailed deer (Odocoileus virginianus) are an important resource for Tennesseans. They are enjoyed by consumptive and nonconsumptive users alike. Approximately 190,000 hunters pursued deer during the 1992-93 hunting season in Tennessee. They successfully harvested 126,999 deer (Greg Wathen, TWRA Assistant Chief of Wildlife, pers. commun.) and it has been estimated that these hunters would have spent approximately $125 million on goods and services related to deer hunting (Whitehead 1991).

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Sixth Eastern Wildlife Management Conferences Summary And What Lies Ahead, James E. Miller Oct 1993

Sixth Eastern Wildlife Management Conferences Summary And What Lies Ahead, James E. Miller

Wildlife Damage Management Conference

I want to begin by expressing appreciation to Ed Jones, Mike King, Greg Yarrow, Pete Bromley, John Heisterberg, and others on the program committee for hosting and conducting this Sixth Eastern Wildlife Damage Management Conference. I also want to express our appreciation to the exhibitors, the National Animal Damage Control Association, and The Wildlife Society (TWS) for their support. I think those of you who are still here will join me in congratulating these people, organizations, and TWS for helping ensure a successful conference. As one of the people who perceived the need for this conference in the early 1980's, …

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Perceptions And Knowledge Of Alabama Fruit And Vegetable Producers Towards Coyotes, M. Chad Philipp, James B. Armstrong Oct 1993

Perceptions And Knowledge Of Alabama Fruit And Vegetable Producers Towards Coyotes, M. Chad Philipp, James B. Armstrong

Wildlife Damage Management Conference

Members of the Alabama Fruit and Vegetable Producers Association (AFVP) were surveyed in 1992-1993 to assess their attitudes and knowledge of coyotes and the amount of perceived damage caused by coyotes. A mail-back questionnaire was developed and pilot tested. The revised questionnaire was sent to all members (N = 84) of the AFVP; individuals whose main income is the production of fruits and vegetables. Seventy-seven percent (n = 61) of those surveyed returned completed questionnaires. Tests for nonresponse bias were conducted and results showed no significant difference. Attitudes were assessed using a Likert scale where 1 = respondents favoring maximum …

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A Summary Of Reported Deer-Related Vehicle Accidents In A Virginia City, Patrick F. Scanlon, William F. Wilmoth, Ralph W. Rexroad Oct 1993

A Summary Of Reported Deer-Related Vehicle Accidents In A Virginia City, Patrick F. Scanlon, William F. Wilmoth, Ralph W. Rexroad

Wildlife Damage Management Conference

Data from 548 reported accidents involving white-tailed deer (Odocoileus virginianus) and vehicles in Lynchburg during the years 1987-1991 were summarized. A majority (54.4%) occurred in the months October, November and December with 25.9% occurring in November. While accidents occurred at all hours, most (50%) occurred between 1700 and 0100 hrs.; about 12% occurred between 0600 and 0900 hrs. Accidents occurred on all days of the week (range 12.8% to 17.0%) and were not higher on work days. Adverse weather did not seem to be a factor increasing collisions; 80% of collisions occurred in clear weather. Most (75%) accidents …

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Landowners Perceptions Of Crop Damage From White-Tailed Deer In South Carolina, Webb M. Smathers Jr., Gary R. Stratton, Derrell Shipes Oct 1993

Landowners Perceptions Of Crop Damage From White-Tailed Deer In South Carolina, Webb M. Smathers Jr., Gary R. Stratton, Derrell Shipes

Wildlife Damage Management Conference

Survey respondents reported a definite increase in the population of white-tailed deer (Odocoileus virginianus) in South Carolina. Almost 73% of the producers from a random sample indicated that deer populations have increased over the five year period preceding 1991. With a higher deer population, crop damage from deer became more prevalent, and 72% of the producers indicated having some level of damage. The producers in the sample had mixed feelings about the damage their crops received with 70% indicating that the damage was either negligible or was tolerable in exchange for having deer around. In South Carolina the …

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Status Of Alpha-Chloralose And Other Immobilizing/Euthanizing Chemicals Within The Animal Damage Control Program, Paul P. Woronecki, William L. Thomas Oct 1993

Status Of Alpha-Chloralose And Other Immobilizing/Euthanizing Chemicals Within The Animal Damage Control Program, Paul P. Woronecki, William L. Thomas

Wildlife Damage Management Conference

In 1992 the U.S. Department of Agriculture (USDA), Animal and Plant Health Inspection Service, Animal Damage Control (ADC) program was granted approval from the U.S. Food and Drug Administration (FDA), under a continuing Investigational New Animal Drug agreement, to use Alpha-chloralose (A-C) nationwide for capturing nuisance waterfowl, coots, and pigeons. FDA and ADC have imposed several requirements, restrictions and conditions on the operational use of A-C. Training and certification are required to use A-C and other approved immobilizing and euthanizing agents.

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Can Simple Random Sampling Confidence Intervals Be Used On Transect Sampling Data?, William Noble Apr 1993

Can Simple Random Sampling Confidence Intervals Be Used On Transect Sampling Data?, William Noble

Conference on Applied Statistics in Agriculture

When sampling geographic regions, transect sampling may be easier and cheaper than simple random sampling. However, transect sampling data is more difficult to analyze. In the past, transect sampling data has sometimes been analyzed as if it was the result of simple random sampling. The purpose of this note is to present simulation results which show that this can lead to vastly inaccurate conclusions when one is calculating confidence intervals. In particular, an example is given of a purported 95% confidence interval which is actually a 49% confidence interval.

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Binomial Variation In The Sex Composition Of Pig Families, Thomas Kirchoff, D. F. Cox Apr 1993

Binomial Variation In The Sex Composition Of Pig Families, Thomas Kirchoff, D. F. Cox

Conference on Applied Statistics in Agriculture

Given the known mechanisms for sex determination, the number of males in families of pigs should follow a binomial distribution. A report of deviations from binomial expectation prompted an investigation of 33,176 pig records from two breeds collected on a single farm. Two methods of assessing the agreement with the binomial distribution found no evidence of significant lack of fit.

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A Permutation Test For A Repeated Measures Design, James J. Higgins, William Noble Apr 1993

A Permutation Test For A Repeated Measures Design, James J. Higgins, William Noble

Conference on Applied Statistics in Agriculture

Multivariate permutation tests have advantages over conventional methods in analyzing repeated measures designs. The tests are exact for all sample sizes regardless of the underlying population distribution from which the observations are selected. More importantly the tests do not require a priori assumptions about the form of the correlation structure, obviating the need to check Huynh-Feldt conditions. An example is given of how a multivariate permutation test may be conducted in a context frequently encountered in agricultural research. The SAS program corresponding to this example is also given.

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Litter Mate Correlations In The Weight Of Pigs, Thomas Kirchoff, D. F. Cox Apr 1993

Litter Mate Correlations In The Weight Of Pigs, Thomas Kirchoff, D. F. Cox

Conference on Applied Statistics in Agriculture

Competition may influence the weights of animals confined to litters or pens, if conditions occur that limit the space and the feed provided, by inducing a negative correlation among the weights within the groups. An example of the phenomenon appeared in the birthweight of pigs where the intra-class correlation declined in a linear manner with increasing litter size. The data consisted of records on 33,165 pigs from 3282 litters raised on a single farm.

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Overcoming Resistance To Multivariate Analysis Over Time, April J. Milliken, Anne M. Parkhurst Apr 1993

Overcoming Resistance To Multivariate Analysis Over Time, April J. Milliken, Anne M. Parkhurst

Conference on Applied Statistics in Agriculture

One aspect of statistical consulting is assessing a clients needs. Sometimes the need for simplicity beclouds the information contained in the experiment. As an example, an experiment was performed as a multivariate study with repeated measures, yet the client preferred numerous univariate analyses that ignored time. The challenge was to show how a more sophisticated analysis provided additional insight into the biological process. Various covariance structures were employed to illustrate the usefulness of progressively more complex analyses. Multivariate methods were performed to utilize the correlation among variables to illuminate biological concepts. To complicate the whole process, an additional problem occurred …

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A Comparison Of Algorithms For Selecting An Optimum Sample From H Strata Using K Variables, M. Williams, H. T. Schreuder Apr 1993

A Comparison Of Algorithms For Selecting An Optimum Sample From H Strata Using K Variables, M. Williams, H. T. Schreuder

Conference on Applied Statistics in Agriculture

In stratified sampling with k different variables and H strata it is often of interest to minimize the survey cost with respect to variance restrictions on each of the k variables. This problem has previously been solved using compromise solutions or using a linear approximation to this nonlinear problem. In this paper a nonlinear optimization routine is tested on this problem. The formulation of the problem in its original form proved problematic. For the test cases run, the transformation th = l/nh, where nh is the number of samples in stratum h, performed best when k …

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Imputing Characteristic Values Of Agricultural "Seed-Stock", Bbryan E. Melton, W. Arden Colette, Richard L. Willham Apr 1993

Imputing Characteristic Values Of Agricultural "Seed-Stock", Bbryan E. Melton, W. Arden Colette, Richard L. Willham

Conference on Applied Statistics in Agriculture

Statistical methods of regression and mathematical (linear) programming are employed to combine principles of economics and genetics in a conceptual, multi-step, model of valuation for biotechnical change. The resulting model has the capacity to estimate the value of changes in specific characteristics for specific production environments, whether those changes are accomplished by traditional plant and animal breeding methods or by genetic engineering. The application of the model is illustrated with an example of commercial cow-calf production under conditions typical of the Texas Panhandle using a total of 32 breed groups.

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Fuzziness In Forest Survey Design Optimization, George Gertner, Xiangchi Cao Apr 1993

Fuzziness In Forest Survey Design Optimization, George Gertner, Xiangchi Cao

Conference on Applied Statistics in Agriculture

When using optimization techniques to optimize a sampling with partial replacement design, it is often assumed that the following parameters are known exactly: 1) desired level of sampling error or total sampling cost for the survey; 2) variable costs; and 3) population variance and correlation coefficients. In practice, however, these parameters needed for finding the optimal design are only educated guesses. The parameters can be considered to be fuzzy. In this paper, brief consideration is given to the optimization of a sampling with partial replacement design using nonlinear programming techniques with fuzzy parameters. The basis of this method is to …

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The Effect Of Weather Station Density On Crop Yield Forecasts, M. Denice Mccormick Apr 1993

The Effect Of Weather Station Density On Crop Yield Forecasts, M. Denice Mccormick

Conference on Applied Statistics in Agriculture

The National Agricultural Statistics Service (NASS) uses regression models to forecast yield for crops such as corn, soybeans and winter wheat. Analyses were conducted on the use of precipitation data in these regression models (McCormick and Birkett 1992, and McCormick 1993). Precipitation data are obtained from two sources. The National Climatic Data Center (NCDC) supplies historic precipitation data used for developing regression model parameters. The Climate Analysis Center (CAC) supplies current year precipitation data that are used as regression model input. CAC weather station density is sparse across the U.S. in many major agricultural areas compared to NCDC weather station …

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Tests And Estimators Of Multiplicative Models For Variety Trials, P. L. Cornelius, J. Crossa, M. S. Seyedsadr Apr 1993

Tests And Estimators Of Multiplicative Models For Variety Trials, P. L. Cornelius, J. Crossa, M. S. Seyedsadr

Conference on Applied Statistics in Agriculture

Some recently obtained results on cross validation, hypothesis test and estimation procedures for multiplicative models applied to multi-site crop variety trials are presented. The PRESS statistic is more sensitive to overfitting and choice of model form than data-splitting cross-validation. Because of their extreme liberality, Gollob F-tests should not be used to test multiplicative terms. FGH tests effectively control Type I error, but are conservative for tests of terms for which the previous term is small. "Simulation tests" have greater power than FGH tests, but still effectively control Type I error rates. Simulation results and cross validation in two examples suggest …

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Designing Alfalfa Yield Trials For Comparing Long-Term Yields, G. B. Schaalje, S. N. Acharya Apr 1993

Designing Alfalfa Yield Trials For Comparing Long-Term Yields, G. B. Schaalje, S. N. Acharya

Conference on Applied Statistics in Agriculture

An aspect of experimental design that must be taken into consideration for variety trials of perennial crops is the number of years to continue the trial. By tradition, alfalfa forage yield trials are harvested for three or four production years, but the consumers of information from these trials, the producers, often keep their stands in production for more than four years. This study developed a statistical efficiency measure for evaluating the adequacy of forage trial designs with specified numbers of years and replicates, based on a multivariate linear model. The measure was applied to data from four long-term trials grown …

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On Multivariate Analyses Of Crossover Designs, Dallas E. Johnson, Carla Goad Apr 1993

On Multivariate Analyses Of Crossover Designs, Dallas E. Johnson, Carla Goad

Conference on Applied Statistics in Agriculture

In crossover experiments, treatments are assigned to experimental units in successive periods. Traditional analyses of crossover designs with three or more periods assume that the observations in successive periods satisfy conditions similar to those utilized in the analysis of many repeated measures experiments. The successive measurements are assumed to satisfy conditions known as the Huynh-Feldt conditions. This paper gives a test for the Huynh-Feldt conditions and discusses possible analyses of crossover experiments, including tests for carryover, when the Huynh-Feldt conditions are not satisfied.

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The Estimation Of Fixed Effects In A Mixed Linear Model, F. Nabugoomu, O. B. Allen Apr 1993

The Estimation Of Fixed Effects In A Mixed Linear Model, F. Nabugoomu, O. B. Allen

Conference on Applied Statistics in Agriculture

The estimation of fixed effects is considered for small, unbalanced, mixed linear models. The two-stage estimator, in which the variance components are first estimated by ML or REML, is compared to the intra-block (IB) estimator, the ordinary least squares (OLS) estimator (ignoring the random effects) and the Gauss-Markov (GM) estimator. Comparison is made, based on 100 simulated data sets each, for 6 designs (3 BIBD's and 3 unbalanced designs). In comparing loss of information, relative to the GM lower bound, the two-stage procedures (using either ML or REML) are recommended for all but the smallest and least balanced design. The …

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Simple Estimations Of The Variance Components And The Fixed And Random Effects In Mixed, Three-Stage, Hierarchal Models, C. Philip Cox Apr 1993

Simple Estimations Of The Variance Components And The Fixed And Random Effects In Mixed, Three-Stage, Hierarchal Models, C. Philip Cox

Conference on Applied Statistics in Agriculture

FRR (Fixed, Random, Random) hierarchal models in which the first-stage" elements are fixed and the second and third-stage elements are random, are used in analyses of comparative experiments and, extensively, in animal breeding contexts where, in the latter, estimates of the second-stage elements and of combinations of them with first-stage elements, are of practical interest. The two procedures, i) empirical BLUP (Best Linear Unbiased Prediction) and ii) a Bayesian approach, used when the ratio of the within-second-stages and the within-third-stages variances is unknown are 'computationally intensive'. When the ratio of the second- to the third-stage variances is large, an alternative …

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Mixed Models Combined Analysis Of Independent Grazing Trials, H. A. Fribourg, J. C. Waller, R. W. Thompson, W. L. Sanders Apr 1993

Mixed Models Combined Analysis Of Independent Grazing Trials, H. A. Fribourg, J. C. Waller, R. W. Thompson, W. L. Sanders

Conference on Applied Statistics in Agriculture

The mixed models procedure (MMP) was used to analyze pooled data sets from 12 independent studies over 13 yr at 9 locations in 7 states to provide combined estimates of daily gains by beef steers grazing tall fescue pastures with different levels of infestation by Acremonium coenophialum, with and without clover. Spring, summer, and combined spring + summer data were analyzed separately. The MMP permitted estimation of the fixed effects of treatments over a broad inference space of future years and different tall fescue pastures over a wide geographic range, detected some relationships not apparent in the individual studies, …

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Spatial Analysis Of Yield Trials Using Separable Arima Processes, M. O. Grondona, J. Crossa, P. N. Fox, W. H. Pfeiffer Apr 1993

Spatial Analysis Of Yield Trials Using Separable Arima Processes, M. O. Grondona, J. Crossa, P. N. Fox, W. H. Pfeiffer

Conference on Applied Statistics in Agriculture

Spatial analysis procedures based on one-dimensional and two-dimensional (separable) ARIMA (Auto Regressive Integrated Moving Average) processes were used to analyze several yield trials. Two criteria were used to determine the best spatial model: 1) standard error of the treatment difference (SED) and 2) mean squared error (MSE) of prediction based on a cross-validation approach. It is found that spatial models with two-dimensional exponential covariance functions are frequently the best models regarding SED and MSE. Differenced models are frequently the best models regarding SED and the worst with respect to MSE.

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Spatial Statistical Analysis For The Area-Of-Influence Experiments, Bahman Shafii, William J. Price, Don W. Morishita Apr 1993

Spatial Statistical Analysis For The Area-Of-Influence Experiments, Bahman Shafii, William J. Price, Don W. Morishita

Conference on Applied Statistics in Agriculture

The area-of-influence (AOI) approach to quantifying crop/weed competition involves measuring the effect of individual weed plants on crop growth and yield at specified distances away from the weed plant. AOI experiments are often analyzed using classical statistical techniques based on the assumption that successive observations on crop response are independent in spite of their distribution in space. However, as the distance varies along the row, the competitive ability will vary spatially so that observations located nearby are expected to be more alike than those separated by large distances. Analyses based on spatial dependencies will therefore provide a more comprehensive understanding …

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