Life Sciences Commons^™

The Prairie Naturalist Volume 24. No.2 June 1992

The Prairie Naturalist

FIRST FLOWERING DATES AND FLOWERING PERIODS OF PRAIRIE PLANTS AT WOODWORTH. NORTH DAKOTA ▪ J. M. Callow, J A. Kanlrud, and K.F. Higgins

PROBABLE DISTRIBUTION OF THE WOODCHUCK IN NORTH CENTRAL KANSAS ▪ J.R. Choate and T. W. Haner

NEST AND NEST SITE CHARACTERISTICS OF SOME GROUND-NESTING NON-PASSERINE BIRDS OF NORTHERN GRASSLANDS ▪ H A. Kantrud and K.F. Higgins

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA ▪ R.N. Randall

COMPARISON OF SIZE STRUCfURE AND CATCH RATE FOR LARGEMOUTH BASS SAMPLES COLLECTED BY ELECTROFlSHING AND ANGLING ▪ DJ. Isaak, T.D. Hill, and D.W. Willis

MULE DEER HABITAT USE IN THE NORTH DAKOTA …

Public Oyster Shoal Survey - Spring 1992, Bruce J. Barber

Reports

Oysters have been harvested from Virginia waters as long as humans have inhabited the area. Depletion of natural stocks in the late 1880's led to the establishment of regulations by public fisheries agencies. A survey of bottom areas in which oysters grew naturally was completed in 1896 under the direction of Lt. Baylor, USN. These areas (over 243,000 acres) were set aside by legislative action for public use and have come to be known as the Baylor Survey Grounds or Public Oyster Grounds of Virginia, and are presently administered by VMRC, the Virginia Marine Resources Commission (Haven et al., 1978). …

Evidence For Helical Structures In Poly(1-Olefin Sulfones) By Transmission Electron Microscopy, George C. Ruben, W H. Stockmayer

Dartmouth Scholarship

Transmission electron microscope images were obtained of fractions of poly(1-tetradecene sulfone) and poly(cyclohexene sulfone) cast from very dilute solutions (0.007%, wt/vol) and rapidly freeze-dried on a mica surface. The samples were then vertically platinum-carbon (Pt-C) replicated with 9 +/- 0.3-A Pt-C and held together with 128 A of electron-transparent evaporated carbon. The Pt-C coating enlarges the molecular chain diameters by approximately 5 A, so that a single polysulfone chain has an apparent diameter of 9-12 A in the transmission electron microscope. Poly(1-tetradecene sulfone) forms short helical regions that show irregular helical turns of pitch 7-18 A, two to eight turns …

A Survey Of Electronic Environmental Controllers, Richard S. Gates, Douglas G. Overhults, Larry W. Turner

Biosystems and Agricultural Engineering Faculty Publications

Sixteen commercially available electronic environmental controllers were evaluated. The units were classified according to enclosure type, analog versus microprocessor based control, power supply, sensors, alarms, control relays and triac output, interval timers, outside temperature feedback, and retail price. An assessment of these controllers indicated several critical limitations in the application of this technology.

The use of integrated controllers for animal production has the potential for substantial improvements in production efficiencies. If the limitations observed in the present controller technology, as represented by this sample, are addressed, industry acceptance of the technology can be accelerated. A uniform standard to address this …

Arkansas Soil Fertility Studies 1991, Wayne E. Sabbe

Arkansas Agricultural Experiment Station Research Series

Contained within this publication are progress reports on the specific aspects of the soil fertility program at the University of Arkansas in 1991. In most instances, the reports are not final reports, but they may contain data from several years. Further details on each report can be obtained from the respective project leaders.

Desert Bighorn Sheep And Riverboat Interactions In Cataract Canyon, Utah, Mark C. Stanger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied desert bighorn sheep (Ovis canadensis nelsoni) behavior and habitat use in response to boating activities during 1985. The percent of total observed time in attention behavior before the boating season, during the boating season, and while riverboats were< 0.8 km from bighorn sheep groups was 1, 1.4, and 12.2, respectively. Estimated energy expenditure did not significantly differ for high riverboat pressures (2 > 0.2) or seasonal comparisons (2 > 0.1). Habitat use significantly differed for proximity to the river, which was probably related to the summer use of the river for drinking. Moderate, minor, and no responses to passing riverboats were observed 3, 39, and 58%, respectively. Responses to riverboats did not significantly differ according to time of day (2 > 0.15) or …

Effects Of Polyacrylamide On Rangeland Soils And Plants, Saud Leily R. Al-Rowaily

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this study were to determine the effects of two forms of polyacrylamide (PAM) conditioners (Cross-linked and Non-cross-linked PAM) on evaporation, saturated hydraulic conductivity, water retention, crust and crack formation of soils, seed germination, and seedling and tubeling growth.

The two PAM conditioners, 0.2% concentration by weight, were mixed with seven soils of different textures (sandy loam, silt, silty clay loam, silt loam, fine sand, medium sand, and coarse sand) to investigate the effects on evaporation, saturated hydraulic conductivity, and water retention. Soil samples of different textures were brought to field capacity and placed in a growth chamber …

Mobilization Of Iron Enhances The Iron-Dependent Biochemical Reactivity Of Asbestos In Vitro And Contributes To The Cytotoxicity Of Asbestos In Cultured Cells, Loren Glen Lund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Asbestos related research began approximately 60 years ago, yet, the mechanism(s) by which asbestos exerts its biological effects is not well understood. The hypothesis upon which this dissertation is based is that mobilization of iron from asbestos enhances the iron-dependent biochemical reactivity of asbestos in vitro and contributes to asbestos-dependent cytotoxicity. The specific aims for this hypothesis were, 1) to determine whether iron was responsible for the biochemical reactivity of asbestos in vitro and asbestos-induced cytotoxicity in cultured cells, and 2) to determine whether mobilization of iron from asbestos enhanced the reactions catalyzed by asbestos in vitro and contributes to …

The Influence Of Redd Distribution And Microhabitat Availability On The Distribution And Abundance Of Young-Of-The-Year Trout In The Green River, Utah, Michael J. Buntjer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Redd distribution, redd density, and physical habitat were used to explain the distribution and abundance of young-of-the-year (YOY) brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in the Green River, Utah. The importance of variables at both a microhabitat and macrohabitat scale were assessed using stepwise regression analysis. Availability of cover (rock and vegetation) and proximity to spawning sites were the most important variables used to explain the distribution and abundance of YOY brown trout and rainbow trout. In addition, YOY brown trout and rainbow trout occupied specific microhabitats and showed patterns of use for …

Soil Heterogeneity And Its Exploitation By Plants, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this dissertation I first examine the ability of individual plants in the field to garner localized soil nutrients. I then measure actual soil variability around perennial plants and use various statistics to quantify the scale and degree of that variability.

Soil patches on opposite sides of Pseudoroegneria spicata tussocks were treated with distilled water or a nutrient solution containing N, P, or K in three field experiments. When P was augmented in the enriched soil patches, rates of P uptake increased significantly for roots from enriched patches compared with roots in control patches. Rates of ammonium and potassium uptake …

Dynamic Multi-Species Animal Habitat Modeling With Forest Succession Models, Stephen A. Compton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research determines and demonstrates the ability to simulate dynamic multi-species animal habitat suitability with forest succession models. A literature review of dynamic animal habitat models is presented. The structure of an existing forest simulation model (MASS10) was modified from a basal area-based model to a volume-based model (DYNAM10). The forest model was calibrated using data from permanent-plot growth and vegetation samples collected by USDA Forest Service Forest Survey procedures. The theoretical growth parameters used to simulate stand development were validated. Predictions of DBH and height growth, as well as stand-level behavior, were verified. A subroutine, VEGDYN, was added to …

The Need For The Analysis Of Treatment X Period Interaction In Animal Experiments, L. A. Goonewardene, L. Z. Florence

Conference on Applied Statistics in Agriculture

Many growth experiments, in which weights are taken at different times on the same animals, involve the comparison of factorial main effects and interactions but exclude time (period) as an effect. The objective of this paper is to show that more information can be obtained by analysing the data as a repeated measures design. As an example, feedlot cattle being prepared for market are often on growth implants and provided different diets depending on the stage of growth and maturity. Growth promoting implants, either single or double, may be slow or fast acting. During the growing period, a diet with …

A Comparison Of Double Sampling Regression Estimators, Dennis L. Clason, G. Morris Southward

Conference on Applied Statistics in Agriculture

We investigate three alternative models for estimating the mean of a population using double sampling survey techniques. One estimator was found in the range science literature (Cook and Stubbendieck, 1986), another is the estimator presented by Cochran (1977). The third estimator uses method-of-moments estimators with measurement error regression models. Simulation studies suggest that the measurement error model does not work well when the slope is appreciably different from unity. Delta method variance estimators of the measurement error model may give negative variance estimates under these circumstances. The other estimators have better small sample performance (both are approximately unbiased, and have …

Simplified Data Analysis For Generally Balanced But Messy Experimental Designs, Richard E. Lund

Conference on Applied Statistics in Agriculture

Johnson posted the essential elements of a 'messy' experimental design and challenged participants at the 1991 KSU Conference on Applied Statistics in Agriculture to provide an analysis. Subsequently, he proposed an analysis using SAS. The experiment was laid out by a soil scientist and involved six classifying factors in an intricate crossing and nesting arrangement which lead to a need to consider eight error terms. My objective at the poster session was to show by live computer demonstration that the analysis can be setup and conducted more easily by use of software applying Wilkinson's methodology.

Soil Properties And Landtypes--Classification And Identification With Discriminant Analysis, R. David Hammer, John W. Philpot

Conference on Applied Statistics in Agriculture

Intensive land use is requiring more detailed information about patterns and magnitudes of soil variability than can be acquired through traditional soil survey techniques. Discriminant analysis is a mathematical method of numerical classification which could be used to identify discrete populations of soils in their natural settings. The hypothesis of this study was that discriminant analysis could be used to group soils on landtypes on the Mid-Cumberland Plateau. A large data set (132 observations of 29 soil variables) was collected from three landtypes at two Cumberland Plateau locations. Discriminant analysis was used to classify the soil observations into landtypes. Canonical …

Regression Modeling Using Principal Components, Shahar Boneh, Gonzalo R. Mendieta

Conference on Applied Statistics in Agriculture

In this paper we present a new stepwise method for selecting predictor variables in linear regression models and its application to agricultural data analysis. This method is an extension of principal component regression, and it consists of iteratively selecting original predictor variables one at a time from repeatedly selected subsets of principal components. The reasoning behind the method and its implementation are discussed, and an example of applying the method to agricultural data is given. The example also demonstrates the advantages of the proposed method over some known methods.

An Example Of Path Analysis Applied To Classification Variables Applied To Classification Variables, Richard E. Lund, Albert L. Scharen

Conference on Applied Statistics in Agriculture

Path analysis was originally proposed to decompose and interpret causal linear relationships among a set of continuous stochastic variables. Research designs necessarily employed the natural variation in the system rather than the technique of controlling independent variables by selection of levels and categories which is emphasized in many experimental designs. Path coefficients are closely related to correlation coefficients, the size of which will be controlled when variation in the system is controlled. We examine a data set produced by research related to worldwide occurrence of a wheat pathogen and describe techniques for applying path analysis to its variables, some of …

When Should Random Effects Be Included In Estimable Functions And When They Should Not?, David C. Blouin

Conference on Applied Statistics in Agriculture

In the mixed model, the behavior of linear functions of the fixed and random effects is examined. It is found that inclusion of certain functions of random effects can lead to estimators which are equivalent to those under a fixed effects model and are inconsistent with the inherent structure of the mixed model. Three examples are presented which illustrate the behavior of linear functions of the fixed and random effects. These functions represent the broad, narrow and intermediate inference spaces as introduced by McLean, Sanders and Stroup (1991). Which random effects should be included in the model is discussed. Random …

Analyzing Split-Plot Andrepeated-Measures Designsusing Mixed Models, Russ Wolfinger, Nancy Miles-Mcdermott, Jenny Kendall

Conference on Applied Statistics in Agriculture

We first introduce the general linear mixed model and provide a justification for using REML to fit it. Then, for an irrigation example, we present several mixed models of increasing complexity. The initial model corresponds to a typical split-plot analysis. Next, we present covariance structures that directly describe the variability of repeated measures within whole plots. Finally, we combine the above types into more complicated mixed models, and compare them using likelihood-based criteria.

Analysis Of Mixed Models Without Mixed Models Software, George A. Milliken

Conference on Applied Statistics in Agriculture

The recent development of mixed model software has expanded the use of mixed models analysis, but mixed models have been analyzed using non-mixed models software for many years. The purpose of this paper is to discuss the differences, similarities, advantages and disadvantages of the two approaches. Section 1 introduces the mixed model with two examples. The analysis of the mixed model using mixed models software is presented in Section 2 and the analysis of the mixed model using non-mixed models software is described in Section 3. Finally, an 'example' is used to compare the two methodologies.

Options For Analyzing Unbalanced Split-Plot Experiments: A Case Study, Marta D. Remmenga, Dallas E. Johnson

Conference on Applied Statistics in Agriculture

Unbalanced split-plot experiments present many analysis problems. This paper discusses some of the difficulties by comparing the results of the analysis recommended by Milliken and Johnson (1984) to a set of minimal sufficient statistics using a small experiment from Milliken and Johnson as a case study. The estimators used by Milliken and Johnson are not necessarily the best (smallest variance) estimators. A set of minimal sufficient statistics is used to show that the whole plot error term suggested by Milliken and Johnson does not have a distribution that is proportional to an exact chi-square distribution and is not always independent …

The Analysis Of Tree Ring Chronologies Using A Mixed Linear Model, O. Brian Allen, Daniel A.J. Ryan, David L. Mclaughlin

Conference on Applied Statistics in Agriculture

The analysis of a tree's annual growth rings can provide a great deal of information about the environment in which the tree has grown. In this paper we propose statistical methodology for analysing the incremental growth of sugar maple sampled throughout southern and central Ontario, by the Ontario Ministry of the Environment. Two trees, ranging in age from 75 to 150 years, were sampled from each of 42 stands in 6 regions. The data were analysed using a mixed linear model, incorporating age of tree, region, year, a year by region interaction and average monthly air temperature and total seasonal …

Estimating Variance Functions For Weighted Linear Regression, Michael S. Williams, Hans T. Schreuder, Timothy G. Gregoire, William A. Bechtold

Conference on Applied Statistics in Agriculture

For linear models with heterogeneous error structure, four variance function models are examined for predicting the error structure in two loblolly pine data sets and one white oak data set. An index of fit and a simulation study were used to determine which models were best. The size of coefficients for linear and higher order terms varied drastically across different data sets, thus it is not desirable to recommend a general model containing both linear and higher order terms. The unspecified exponent model σ²v_i = σ²⁽D_i² H_i)^{k 1} is recommended …

Planning A Safety Study Of An Agricultural Product: Effects Of Land Application Of Phosphogypsum On Radon Flux, Ramon C. Littell, Sudeep Kundu

Conference on Applied Statistics in Agriculture

Traditional agricultural research has been concerned largely with demonstrating that new products or new practices increase yield from plants or animals; i.e. that a change has occurred. Concepts of experimental design have been effectively employed in production-agriculture research planning to control extraneous variation and thereby reduce experimental error. Good data analysis practices have been employed to control type 1 error rate and to correctly compute errors of estimation. In recent years, increased emphasis has been placed on food safety and environmental impact of agricultural products. Studies of these issues are concerned with measuring small effects with required precision or establishing …

A Simple Alternative To The Standard Statistical Model For The Analysis Of Field Experiments With Latin Square Designs, C. Philip Cox, Jeff B. Meeker

Conference on Applied Statistics in Agriculture

Latin Square (LS) designs have long been advocated for field crop experiments on the grounds that '. . . soil fertility and other variations in two directions are controlled.' As counter-evidence, the published standard analyses of eight LS experiments showed that in only two did the sum of squares for both between-rows and between-columns account for appreciable background variability.

Regarding the background concomitant variability as a continuous surface to which treatment effects are additive, it is suggested that a contributory shortcoming of the standard model is that it admits only a restricted class of surfaces because parameters for warp, or …

Designed Experiments In The Presence Of Spatial Correlation, David B. Marx

Conference on Applied Statistics in Agriculture

Soil heterogeneity is generally the major cause of variation in plot yield data and the difficulty of its interpretation. If a large degree of variability is present at a test site, some method of controlling it must be found. Controlling experimental variability can be achieved either by good experimental design or by analysis procedures which account for the spatial correlation. Classical designs are only moderately equipped to adjust for spatially correlated data. More complex designs including nearest neighbor designs, Williams designs, and certain restricted Latin square designs are developed for field experimentation when spatial correlation causes classical designs to be …

Confidence Intervals For Soil Properties Based On Differing Statistical Assumptions, Fred J. Young, R. David Hammer, Jon M. Maatta

Conference on Applied Statistics in Agriculture

Agricultural soil management is becoming increasingly precise as technology advances and as environmental concerns increase. Soil surveys are a readily available source of soils information, but soil properties are reported as generalized values or generic ranges. A need exists to define the central tendencies of soil properties in a rigorous, quantified fashion. Statistically, the central tendency is best expressed as confidence intervals about means or medians. Transect sampling was used to collect data on soil properties within a soil survey map unit. Key questions for data analysis include assumptions of independence within transects and normality. The choice of statistical method …

A Markov Chain Model To Assess Resistance Of Cattle To Horn Flies, Edward Gbur, C. Dayton Steelman

Conference on Applied Statistics in Agriculture

The horn fly is an economically important external permanent parasite of cattle. As part of a research project focused on alternatives to chemical control of the horn fly, a study was conducted to determine the degree of innate resistance of individual cattle to the horn fly. A fly resistant cow was defined as one whose horn fly counts were in the lower quartile of the weekly fly count distributions for a herd more often than would be expected by chance. A Markov chain model was formulated and a small sample test for fly resistance was developed. The model and procedure …

Statistical Analysis Of Genotype-By-Environment Interaction Using The Ammi Model And Stability Estimates, Bahman Shafii, William J. Price

Conference on Applied Statistics in Agriculture

Understanding the implication of genotype-by-environment (GE) interaction structure is an important consideration in plant breeding programs. A significant GE interaction for a quantitative trait such as yield can seriously limit efforts in selecting superior genotypes for both new crop introduction and improved cultivar development. Traditional statistical analyses of yield trials provide little or no insight into the particular pattern or structure of the GE interaction. The Additive Main Effects and Multiplicative Interaction (AMMI) statistical model incorporates both additive and multiplicative components of the two-way data structure which can account more effectively for the underlying interaction patterns. Integrating results obtained from …

Utilization Of The Line-Intercept Method To Estimate The Coverage, Density, And Average Length Of Row Skips In Cotton And Other Row Crops, Jeffrey L. Willers, Sreenivasa R. Yatham, Michael R. Williams, Dennis C. Akins

Conference on Applied Statistics in Agriculture

In row crops, a skip is a length of row within the drill where the crop has failed to establish. If the number of skips and their mean length per acre becomes too high, then considerable losses in crop yield occur. Frequently, farmers are faced with the decision to replant a crop which has row skips. To make the best decision, reliable estimates of the stand loss due to skips must be available. In making this decision, three parameters are useful: the percent of the area per acre that is skipped, the number of individual skips (that is, density) per …