1980-1999

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https://hdl.handle.net/10217/100536

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Open Access
Optical performance of cylindrical absorber collectors with and without reflectors
(Colorado State University. Libraries, 1994) Menon, Arun B., author; Duff, William, advisor; Burns, Patrick J., committee member; Zachmann, David W., committee member
The optical efficiency of a solar collector, which depends on the collector geometry and material properties (i.e., geometry and radiative properties of the cover, absorber and any reflector), contributes significantly towards its overall performance. This optical efficiency is directly proportional to the transmittance-absorptance or τα product for all possible angles of incidence. A 3-D Monte Carlo ray tracing technique is used to determine this τα product for evacuated tubular collectors (ETCs) with cylindrical absorbers in an effort to identify the most efficient optical design parameters. These collectors are asymmetric with respect to the incident solar radiation and their optical efficiencies are therefore difficult to estimate using any other method. The collector geometry is modeled using constructive solid geometry (CSG). CSG allows the generation of complex collector shapes by combining simple primitive objects. The ray tracing algorithm tracks individual photons through the collector geometry to provide a means of obtaining the absorbed fraction for a particular angle of radiation incident on the collector plane. Incidence angle modifiers (IAMs), the ratio of the τα product at a particular set of longitudinal and transverse radiation incidence angles to the τα product at normal incidence are thereby obtained. IAMs are calculated for variations in five different design parameters to determine the most advantageous geometries. It is found that diffusely reflecting back planes significantly enhance optical performance of tubular collectors. Verification of the ray trace calculations is made by comparing with experimental results from the indoor solar simulator at CSU. TRNSYS predicted values of τα are within 1% of the ray trace results for normal incidence tests and within 7% for off-normal tests. Inaccuracies resulting from the use of a multiplicative technique wherein off-axis IAMs are obtained by a multiplicative combination of the biaxial IAMs are also addressed. The multiplicative approach is found to be very inaccurate for angles of incidence greater than 40°. To further assess the relative advantages of tubular collectors over flat plate collectors and whether a reflective back plane is really necessary, the two types of collectors are modeled in a simple fashion and the amount of radiation that is available for collection by each is determined. Calculations show that reflectors would probably not be required for collector slopes in excess of 50°. However, for slope angles less than 50°, a reflector placed behind the tubes is beneficial.
Open Access
Population size estimation using the modified Horvitz-Thompson estimator with estimated sighting probability
(Colorado State University. Libraries, 1996) Wong, Char-Ngan, author; Bowden, David C., advisor
Wildlife aerial population surveys usually use a two-stage sampling technique. The first stage involves dividing the whole survey area into smaller land units, which we called the primary units, and then taking a sample from those. In the second stage, an aerial survey of the selected units is made in an attempt to observe (count) every animal. Some animals, usually occurring in groups, are not observed for a variety of reasons. Estimates from these surveys are plagued with two major sources of errors, namely, errors due to sampling variation in both stages. The first error may be controlled by choosing a suitable sampling plan for the first stage. The second error is also termed "visibility bias", which acknowledges that only a portion of the groups in a sampled land unit will be enumerated. The objective of our study is to provide improved variance estimators over those provided by Steinhorst and Samuel (1989) and to evaluate performances of various corresponding interval procedures for estimating population size. For this purpose, we have found an asymptotically unbiased estimator for the approximate variance of the population size estimator when sighting probabilities of groups are unknown and fitted with a logistic model. We have broken down the approximate variance term into three components, namely, error due to sampling of primary units, error due to sighting of groups in second stage sampling and error due all three components separately in order to get a better insight to error control. Simplified versions of variance estimators are provided when all primary units are surveyed and for stratified random sampling of primary units. Third central moment of population size estimator was also obtained. Simulation studies were conducted to evaluate performances of our asymptotically unbiased variance estimators and of confidence interval procedures such as the large sample procedure, with and without transformation, for constructing 90% and 95% confidence intervals for the population size. Confidence intervals for the population size were also constructed by assuming that the distribution of log(T-T) is normally distributed, where f is the population size estimate and T is the number of animals seen in a sample obtained from a population survey. From our simulation results, we observed that the population size is estimated with negligible bias (according to Cochran's (1977) working rule) with a sample of at least 100 groups of elk obtained from a population survey when sighting probabilities are known. When sighting probabilities are unknown, one needs to conduct a sightability survey to obtain a sample, independent of the sample obtained from a population survey, for fitting a logistic model to estimate sighting probabilities of sighted groups in the sample obtained from the population survey. In this case, the population size is also estimated with negligible bias when the sample size of both samples is at least 100 groups of elk. We also observed that when sighting probabilities are known, we needed a sample of at least 348 groups of elk from a population survey to obtain reasonable coverage rates of the true population size. When sighting probabilities are unknown and estimated via logistic regression, the size of both samples is at least 428 groups of elk for obtaining reasonable coverage rates of the true population size. Among all these confidence intervals, we found that those approximate confidence intervals constructed based on the assumption that log (T-T) is normally distributed and using the delta method have better coverage rates and shorter estimated expected interval widths. Confidence intervals for the population size using bootstrapping were also evaluated. We were unable to find an existing bootstrapping procedure which could be directly applied to our problem. We have, therefore, proposed a couple of bootstrapping procedures for obtaining a sample to fit a logistic model and a couple of bootstrapping procedures for obtaining a sample to construct a population size estimate. With 1000 pairs of independent samples from a sightability survey and a population survey, each sample of size 107 groups of elk and using 500 bootstrap iterations, we obtained reasonable coverage rates of the true population size. Our other problem is model selection of a logistic model for the unknown sighting probabilities. We evaluated the performance of the population size estimator and our variance estimator when we fit a simpler model. For this purpose, we have derived theoretical expressions for the bias of the population size estimator and the mean-squared-error. We found, from our simulation results of fitting a couple of models simpler than the full model, that the population size was still well estimated for the fitted model based only on group size but was severely overestimated for the fitted model based only on percent of vegetation cover. For both fitted models, our variance estimator overestimated the observed variance of 1000 simulated population size estimates. We also found that the approximate expression of the expected value of the population size estimator we derived for a fitted model simpler than the full model has negligible bias (by Cochran's (1977) working rule) relative to the average of those 1000 simulated population size estimates. The approximate expression of the variance of the population size estimator we derived for this case somewhat underestimated the observed variance of those 1000 simulated population size estimates. Both approximate expressions apparently give us an idea of the expected size of the population size estimate and its variance when the fitted model is not the full model.
Open Access
Investigation of enhanced-reflectivity features embedded within a wintertime orographic cloud on 28-29 November 1984
(Colorado State University. Libraries, 1994) Baker, Ian T., author; Grant, Lewis O., advisor; Mielke, Paul W., committee member; Cotton, William R., committee member
A combination of aircraft, sounding, surface, vertically-pointing ku-Band radar and dual-channel radiometer data was used to investigate the microphysical characteristics of enhanced-reflectivity areas embedded within an orographic cloud in northwestern Colorado on 28-29 November 1984. The orographic cloud was associated with the passage of an open wave and upper-level front over the region, and embedded within the cloud were regularly-spaced areas of increased reflectivity as seen by the vertically-pointing radar. The radiometer observed a cyclical component on both the liquid and vapor channels when oriented in the vertical. Aircraft data reveal that there was supercooled liquid water in the cloud at levels as high as 41 kPa and as far as 55 km upwind of the barrier. 2D-C and 2D-P probe data indicated two crystal regimes, one where concentrations in individual size bins were larger and spectra were broader, indicating crystal growth. In the other, concentrations were smaller and size spectra were narrower. Radar data indicate that the enhanced-reflectivity regions were between 10-20 km apart, with a length dimension on the order of 5 km wide. It is believed that the presence of the enhanced-reflectivity areas is closely linked to the presence of a decoupled layer on the windward side of the barrier, and preliminary evidence points to a gravity-wave mechanism as a physical cause.
Restricted
Pardon blooming
(Colorado State University. Libraries, 1983) Hayden, M. D., author; Ude, Wayne, advisor; Tremblay, Bill, committee member; Mitchell, Carol, committee member; McMurray, George R., committee member
A toad, a butterfly, a human being, a philodendron, all need sustenance, need air; all grow and change. Clamp a bottle over a living creature and it suffocates, its movement restricted, its possibilities limited. For an individual, rigidity becomes a glass bottle, and those who struggle to escape the bottle must experience something painful in the process. Glass bottle. Rigidity of society and tradition. For some, rigidity comes from their own acceptance of society's rules or tradition's importance. A creature raised in the confines of a glass bottle is uncomfortable with sudden freedom, as uncomfortable, perhaps as a free creature confined. For others, rigidity is imposed from the outside. These rigid boundaries of society and tradition may not be apparent until they conflict with the individual's inner needs for growth, but when they do conflict, the individual must find air to breathe. Some escape the glass bottle; most don't. Glass bottle. Rigidity of linear time. Although the concept of time as linear is arbitrary in Western thought (some American Indian tribes do not have such a concept), most of us assume our past happened to us in the time line before now. If we remain always the same person, the past, the memories happen continually. But if we have grown and changed, we are not the same person as the child of ten, the adolescent of fifteen, the young adult of twenty. The memories we hold happened to a different person because we are always becoming someone else. Linear time does not allow this idea, but circular time, or even spherical time, does. Glass bottle. Rigidity of gender. Separation of the sexes by innate differences or by imposed societal roles creates a rigid boundary that obscures the commonality of human experience, that denies the similarity of emotion and need in men and women. The first thing that strikes the careless observer is that women are unlike men. They are 'the opposite sex'--(Though why 'opposite' I do not know; what is the 'neighboring sex'?) But the fundamental thing is that women are more like men than anything else in the world. 1 Glass bottle. Rigidity of language. The boundaries of our language define the boundaries of our world. Those things we cannot perceive, we cannot say, and vice versa. The stories in this collection seek to express what our language has no way of saying, to escape a rigid structure, voice or time, to break glass bottles.
Open Access
Increasing fruit and vegetable consumption in grade-school children
(Colorado State University. Libraries, 1997) Ryan, Linda DeBell, author; Jennifer Anderson, advisor; Bechtel, Peter J., advisor; Kendall, Patricia, committee member; Keefe, Thomas, committee member; Jansen, Duane, committee member
Diets rich in fruits and vegetables have many health benefits. Nutrients in fruits and vegetables such as vitamins, minerals, and fiber help protect individuals from certain cancers and cardiovascular disease. Children in our nation are not meeting the national health objectives or recommendations to eat plenty of fruits and vegetables. This research assessed whether the provision of classroom nutrition education on the benefits of eating fruits and vegetables and providing more fresh fruits and fresh vegetables in the school lunch program increased consumption by grade-school children. This research was completed in three parts. The purpose of part one (The Nutrition Education Intervention Study) was to determine if providing nutrition education to grade-school children and the community increased fruit and vegetable consumption. In this study a nutrition education program was given to the grade-school children and community of Holyoke (experimental group). The effects of the nutrition education intervention were compared to the control group (i.e., the grade-school children and community of Haxtun), which received no intervention. A nutrition education program was developed and designed as a hands-on education program for the children and for the community. The intervention included nutrition education materials, demonstrations, and activities on increasing the consumption of fruits and vegetables and good nutrition. Fruit and vegetable consumption was measured by a 24-hour food recall (children only) and a pre- and post-questionnaire for the children and community. The results showed mean fruit and vegetable consumption increased by 1.37 servings per day (from 2.45 to 3.82) among the grade-school children using the 24-hour food recall assessment method and 0.93 (3.93 to 4.86) using a pre/post self-reported questionnaire (both at p[less than or equal to]0.05 ). The community's mean fruit and vegetable intake increased by 0.66 servings per day (3.28 to 3.94) from the pre to post questionnaire (p[less than or equal to]0.05 ). The purpose of part two (The Fresh Fruit and Vegetable Intervention Study) was to determine if providing quality fresh fruits and fresh vegetables increased consumption by grade-school children. In this study the Department of Defense (DOD) provided fresh fruits and vegetables to schools within Colorado. The schools receiving the fresh fruits and vegetables (experimental group) were compared to schools not receiving fresh produce (control group). The children in the experimental group were offered a variety of high quality of fresh fruits and vegetables in the school cafeteria with their school lunches. Fruit and vegetable consumption was measured by subtracting plate waste from the beginning weight for each fruit and vegetable served. The results were as follows: 1. The experimental group took on an average 2. 70 ounces combined fruits and vegetables per child, the control group took 3.14 ounces per child (p[greater than or equal to]0.05). 2. The children in the experimental group consumed a greater percentage (73%) of fruits and vegetables than the control group (61 %) (p[less than or equal to]0.05). 3. The children in both groups consumed more fruits than vegetables. In part three, the results of the two studies were completed. The results showed that there was no difference in the two approaches, both interventions increased consumption of fruits and vegetables in the grade-school children.
Open Access
Development and evaluation of a nutrition curriculum to prevent obesity in inner-city teens
(Colorado State University. Libraries, 1998) Taitano, Rachael Tatiana, author; Jennifer Anderson, advisor; Auld, Garry, committee member; Kreutzer, Jill, committee member; DeVoe, Dale, committee member; Hill, Jim, committee member
Obesity is a major health concern in the United States. Obese adolescents have been found, later in life, to be at increased risk for noninsulin dependent diabetes mellitus, cardiovascular disease, hypertension and certain cancers. NHANES III and HHANES data reveal that regardless of ethnicity, an estimated 21% of adolescents (12-17 years of age) in the United States are considered overweight or obese. Obese adolescent girls are at especially high risk for remaining obese in adulthood. Adolescence represents a crucial time for reversing and preventing obesity. The purpose of this study was two-fold: 1) to develop a nutrition education curriculum targeting sedentary, inner-city adolescents living in Denver, Colorado; and 2) to evaluate the effectiveness of this curriculum by assessing changes in knowledge, attitudes, self-efficacy, stage of change for exercise and fat intake behaviors, dietary behaviors, physical fitness indices, and certain physiological parameters. The goal of this course was to promote metabolic fitness by modifying food intake and increasing exercise frequency. In Denver Colorado, twenty-three treatment subjects were compared to fifty-three control subjects. The treatment subjects received two years of nutrition education, while the control subjects received none. Formative evaluations were used to establish course content, and the curriculum was developed utilizing Prochaska's Stages of Change along with Bandura's Self- Efficacy and Social Learning Theory. Promotion of behavior change and progression to the next stage of change was accomplished through instruction and activities focused on consciousness-raising, promotion of social support, environmental reevaluation, management of emotional arousal, self-monitoring and self-evaluation, goal-setting, and improving self-efficacy for selecting and eating healthier foods. After two years of intervention, only 36% of the developed curriculum had been delivered to treatment subjects due to instructor related problems. However, despite implementation difficulties, some positive results were seen. Treatment subjects reported significant improvements in: knowledge, their intentions to change fat intake and exercise behaviors (stages of change), their fat intake as measured by two food frequency questionnaires, and their waist-to-hip ratios. The lack of more positive results are most likely due to poor curriculum implementation.
Open Access
Independent validation of the Core Food Security Module with Asians and Pacific Islanders
(Colorado State University. Libraries, 1999) Derrickson, Joda P., author; Jennifer Anderson, advisor; Auld, Garry, committee member; Banning, Jim, committee member; Hall, Bruce, committee member
An independent validation of the national household food security measure-the Core Food Security Module (CFSM) and its categorical algorithm-was conducted with Asians and Pacific Islanders in Hawai’i. Research was conducted in three parts: 1) a qualitative study (n=61). 2) a pilot stability study (n=61), and 3) a study replicating methods used to develop the CFSM (n=1664). Caucasians, Hawaiians and part-Hawaiians, Filipinos and Samoans residing in Hawai’i comprised the ethnic groups of focus. Findings: • Confirmed the face validity of the CFSM with Asians and Pacific Islanders in Hawai’i. • Indicated "balanced meals" was most often perceived as a meal with "meat, starch and a vegetable"; • Indicated the CFSM yields valid and reliable scale measures among Asians and Pacific Islanders in Hawai'i, except possibly with American Samoans (n=23). • Suggest weak credibility, validity and stability of the CFSM categorical algorithm: 27% of 111 households identified as food secure with one or more affirmative reply responded affirmatively to "unable to eat balanced meals"; 50% of 64 households classified as experiencing moderate hunger responded affirmatively to "respondent hungry"; and only 62% were consistently classified in the same category over time. • A ''face valid" algorithm-in which one affirmative response is classified as "at risk of hunger" and those who responded affirmatively to Q10 or to the child hunger question (Q14) were classified as such, regardless of other responses, was a preferred algorithm. Compared to the national algorithm, this algorithm resulted in: a lower percentage classified as food secure (85% vs. 78%); a greater percentage who were classified consistently as food insecure without hunger over time (57% vs. 80%); improved face and concurrent validity. • In general, progressively deteriorating food security status as experienced in Hawai'i resulted in concurrent decreased vegetable intake, and increased reliance on Saimin and resource augmentation behaviors. Prudence must be utilized when extending findings to ethnic groups not studied. Findings warrant further investigation of a shorter household food security measure and reassessment of the CSFM categorical algorithm.
Open Access
Using computer technology to deliver nutrition education to low income populations
(Colorado State University. Libraries, 1997) Gould, Susan Martin, author; Anderson, Jennifer, advisor; Chapman, Phillip, committee member; Auld, Garry, committee member; Kendall, Pat, committee member
Nutrition education has been found to be effective in improving knowledge, attitudes, and behavior, particularly when programs are behavioral oriented and based on theoretical frameworks such as Prochaska's Stages of Change Model, the Social- Cognitive Leaming Theory, and the Communication Theory/Model. Increased nutrition risk has been found to be associated with income level, some minority groups, and education level. A nutrition education program, La Cocina Saludable ("The Healthy Kitchen"), has been developed utilizing abuelas (Hispanic grandmothers) to address some of the nutrition education needs of low-income Hispanic women and children, especially among migrant farm working families. Computer technology provides the opportunity to explore new and creative methods to deliver nutrition education to participants receiving food assistance. If this delivery method is effective, more people can be reached with accurate and consistent messages with less of the recruiting and training challenges found with peer educators. A pictorial version of the Colorado WIC Program Allowable Foods List was created using scanning and desk-top publishing techniques to add pictures and increase the readability of the text. Formative evaluation provided feedback regarding content and design. A final evaluation was completed to determine the preference between the text and pictorial versions. Potential WIC clients preferred the pictorial version (both Spanish and English) by more than 80%. Twelve of 14 grocery store checkers preferred using the pictorial version at their registers. Over 80% of 42 WIC staff surveyed indicated they would use the pictorial version more often with clients and that clients would like them. Building upon these scanning techniques, two units of La Cocina Saludable, "Make It Healthy" and "Make A Change," were adapted to a bilingual interactive multimedia (IMM) program and evaluated. The program was designed to be delivered via touch screen computers to participants of food and other assistance programs. Repeated measures analysis of variance (ANOVA) was used to assess the knowledge gains and reported behavior changes among participants who completed La Cocina Saludable with a computer and those who completed it with an abuela. Significant knowledge gains (p < 0.05) were observed with both methods of delivery. Those who received "Make It Healthy" with the abuela, however, had significantly more gains (p < 0.05) for that outcome than those who used the computer. No significant differences were seen between the abuela and IMM when comparing within the "Make A Change" unit. A few differences were reported for fat and salt behaviors. IMM provides an opportunity to expose more participants to accurate and consistent nutrition education messages and learning activities. Use of a combination of IMM and nutrition educator methods may be an important consideration to increase contacts and optimize gains.
Open Access
Association of pet ownership with eating, exercise, nutritional status, and heart health of seniors
(Colorado State University. Libraries, 1995) Dembicki, Diane Florence, author; Anderson, Jennifer, advisor; Melby, Chris, advisor; Stallones, Lorann, committee member; Auld, Garry, committee member; Barber, Clif, committee member
The familiar adage "pets are good for your health" is an interesting but largely untested theory. Numerous anecdotal remarks on the health benefits of companion animals to the elderly refer to eating and exercise. Research is needed to examine if any health benefits result from pet ownership, and, if so, models must be developed to explain the reasons. An early empirical study found increased survival rate of heart patients due to pets (Freidmann et al., 1980). A theoretical framework is developing based on pet attachment and substitute social support (Stallones et al., 1990). Recent research investigated the effects of pets on risk factors for cardiovascular disease (Anderson et al., 1992). A new model was developed, based on pet ownership leads to better self care, to show possible associations between pet ownership with eating, exercise, nutritional status, and specific cardiovascular risk factors. The major hypotheses tested were pet owners have significantly lower serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides, and higher high-density lipoprotein cholesterol than non-owners and these differences are explained by diet and physical activity. The experimental design was a cross-sectional, observational study of a self-selected convenience sample. Seniors aged sixty and above were solicited at senior congregate meals program sites in north-central Colorado (n=127). Instruments used were questionnaires on eating and exercise, emotional and physical health, social support, and pet attachment, biochemical analyses of diet and blood, and anthropometric and physiological measures. Statistical procedures included two-tailed t-tests, Chi-square, multivariate analysis, correlation coefficients and partial coefficients, and analysis of covariance ; a value of p <0. 05 was considered significant. There were few significant differences in diet, nutritional status, and risk factors for cardiovascular disease and no significant differences in number of exercise activities and duration of walking between pet and nonowners. Dog owners walked significantly longer than nonowners. Pet owners had significantly lower triglycerides than non-owners. It could not be concluded that pet ownership is associated with better diet and nutritional status, greater physical activity, and reduced cardiovascular risk compared to non-ownership in seniors.
Open Access
Development and impact of a Stage of Change bilingual nutrition education program for Hispanics
(Colorado State University. Libraries, 1997) Taylor, Terry, author; Anderson, Jennifer, advisor; Chapman, Phillip, committee member; Auld, Garry, committee member; Kendall, Pat, committee member
A nutrition education program, entitled La Cocina Saludable - The Healthy Kitchen, was designed based on the Stage of Change Model for Behavior Change and implemented in 10 counties in southern Colorado. The objectives were to improve the nutrition related knowledge, skills, and behaviors that lead to healthy lifestyles in a low-income Hispanic and migrant farmworker population. The content of the program included nutrition information designed to help mothers of preschool children provide for their children's nutritional needs. Specifically, the content areas included 1) Make It Healthy - nutrition principles including the Food Guide Pyramid; 2) Make it Fun - making food fun for children using color, texture, size, and shape; 3) Make A Change - modifying recipes and meals to lower fat, lower salt, lower sugar, and increase fiber; 4) Make it Safe - food safety principles; and 5) Make A Plan - budgeting and shopping tips to help stretch food resources. This population presents many obstacles for nutrition educators including limited resources, child care, transportation, time, language, culture, literacy, education, health beliefs, and in some cases, the transient nature of the population. Previous studies suggest that low-income Hispanics often show low intakes of vitamins A and C, calcium, iron, and protein. It follows that they show high rates of diabetes, obesity, infections, and enteric diseases. This program attempted to overcome these barriers by incorporating the use of a flexible program format carried out by abuela (Hispanic grandmother) educators using appropriate processes described in the Stages of Change Model for Behavior Change. The Stage of Change Model categorizes changing individuals into five stages: precontemplation, contemplation, preparation, action, and maintenance. It is suggested that within each stage, individuals emphasize specific processes that help to move them to the next stage. The program design and materials were developed by thoughtful incorporation of these processes. The program was evaluated using a knowledge and skills pre-test, post-test, and six month follow-up survey which included selected elements from WIC and EFNEP program evaluations. An instrument for measuring movement through the five stages was also developed. Final results of the program's evaluation suggest that this type of program based on the Stages of Change Model and using abuela educators as peer educators is effective in changing selected nutrition related knowledge, skills, and behaviors leading to healthy lifestyles. Administration of similar programs should be thoughtfully planned and implemented. Additionally, development and use of a Stage of Change assessment tool suggests key considerations when attempting to measure stages relative to nutrition behaviors for this population.
Open Access
Development and evaluation of a weight control program for obese preadolescent children
(Colorado State University. Libraries, 1992) Hammarlund, Virginia Anne, author; Anderson, Jennifer, advisor; Stone, Martha, advisor; Bowden, David, committee member; Bechtel, Peter, committee member; Fettman, Martin J., committee member
Obesity is a common nutritional problem of American children. Health problems associated with childhood obesity and its continuation into adulthood underscore the need for effective weight control treatment for obese preadolescent children. The purpose of this study was to develop an effective weight control program that incorporated a structured low fat diet, regular exercise, behavior modification, family involvement and a fun learning environment. No weight control treatment for obese preadolescent children has incorporated these factors. The program was designed to teach obese preadolescent children methods to reduce their daily fat intake to between 25 and 30 percent of their total daily caloric intake. Thirty-two obese preadolescent children were recruited from the Cheyenne, Wyoming, area with the assistance of local health care practitioners. Children were randomly assigned to the special intervention group or the standard care group. Children assigned to the special intervention group participated in a newly designed ten week weight control program for obese preadolescent children. Children in the special intervention group changed the nutrient quality but not the fat quantity of their diets. These children, as indicated on their program evaluations and confirmed by nutrient analysis increased their consumption of fruits, vegetables, dairy products and meat. They did not use low fat food substitutions that were emphasized in the program. Analysis of activity factors confirmed that children in the special intervention group had increased their level of physical activity at weeks 10 and 22. Children in the standard care group received the nutritional counseling usually provided by a registered dietitian at the local medical clinic. Children in the standard care group exhibited a significant improvement (P [less than or equal to] 0.05) in relative weight and BMI at weeks 10 and 22. Changes in dietary fat intake of children in the standard care group were associated with changes in their weight status indicators. The greater success of the standard care group was related to the level of family functioning and the type of individualized counseling provided as usual care. Results of this study suggest that obese preadolescent children from dysfunctional families could achieve a greater level of weight control success with individualized care than with a group based program.
Open Access
Novel polynuclear copper compounds of halides and pseudo-halides
(Colorado State University. Libraries, 1987) Reibenspies, Joseph Henry, author; Anderson, Oren, advisor; Elliott, C. Michael, committee member
Mixed-valence compounds (one trinuclear (4) and two polymeric (5,6)) of copper(I,II) containing bridging cyano ligands and the ligands 1 (Pre-H) and 2 (cyclops) have been synthesized and characterized by single crystal X-ray diffraction. For 4, [Cu(1)(μ-NC)]2Cu(CN) · H2O, a= 9.723(2) Å, b = 10.908(2) A, c = 16.184(3) A, ɑ = 97.82(1) ᵒ, β = 103.64(2)ᵒ, γ= 92.21(2)ᵒ. Compound 5 ([Cu(1)(μ-NC)Cu(μ-CN)]n) occurs in three structural modifications. For 5a, a= 7 .755(2) Å, b = 13.179(3) Å, c = 16.508(5) A. For 5b, a= 7.878(2) Å, b = 8.418(2) Å, c = 25.874(4) Å, ~= 94.15(2)ᵒ. For 5c, a= 8.85(1) Å, b = 20.755(8) Å, c = 23.081(8) Å. For 6, [Cu(2)(μ-NC)Cu(μ- CN)·(l/2C6H6)]n, a= 11.667(2) Å, b = 8.962(2) Å, c = 19.895(5) Å,~= 97.58(2)ᵒ. The discrete molecules of 4 contain a trigonal planar [Cu(CN)3]^2- unit, which bridges between two [Cu(l)]+ complexes through two cyano ligands. Each of the polymeric species 5a, 5b, 5c, and 6 consists of a chain of [Cu(CN)2]- units joined by bridging cyano ligands. A cyano ligand also bridges between the copper(I) atoms of the chain and [Cu(1)]+ or [Cu(2)]+ complexes. The structures of three dinuclear copper(II) complexes, in which the Cu(II) atoms are bridged by azido and hydroxo ligands and by either the phenolate oxygen atom of N6OH or N6'OH have been determined by single crystal X-ray diffraction. The compound [Cu2(μ-l,3-N3)(N6O)](ClO4)2·THF (7) crystallized in the orthorhombic space group P 212121, with a= 12.977(2) Å, b = 13.188(3) Å, c = 22.033(6) Å. The compound [Cu2(μ-1,1-N3)(N6'O)](BF4)2·THF (8) crystallized in the orthorhombic space group P21cn, with a= 10.222(2) Å, b = 16.683(4) Å, c = 23.517(7) Å. The compound [Cu2(μ- OH)(N6'O)](BF4)i · THF (9a) crystallized in the monoclinic space group ?21/n, with a= 12.457(3) Å, b = 10.222(3) Å, c = 30.397(10) Å, β= 91.63(2). In these complexes each copper(II) atom is five-coordinate and is bound to three nitrogen atoms and the bridging phenoxo oxygen atom of either N60- or N6'0-. The fifth coordination site on each copper(II) atom is occupied by an atom of the bridging azido or hydroxo ligand. A dinuclear copper(II) complex which contains a bridging iodo ligand and two [Cu(2)]+ moieties has been characterized by X-ray crystallography. [Cu2(2)2I](ClO4) · 2MeOH (10) crystallized in the monoclinic system, space group C2/c, with Z = 4 and a= 21.564(3) Å, b = 11.920(2) Å, c = 14.831(2) Å, β = 96.83(1)ᵒ. Each of the copper(II) atoms in the dimer is coordinated to four nitrogen atoms of ligand 2 and to the bridging iodo ligand. The structures of two phases of the perchlorate salt of the copper(II) complex of 1 and methanol have been characterized by X-ray crystallography. For the room temperature phase {[Cu(1)]C1O4 · 1/2 MeOH}n (11a), a= 23.018(3) Å, b = 6.903(1) Å, c = 22.511(3) Å, β= 105.48(1)ᵒ. For the low temperature phase { [Cu(l)]ClO4 · 1/2 MeOH}i ((llb), a= 6.850(2) A, b = 11.886(3) A, c = 22.303(5) A, a= 75.26(2)0 , β= 88.97(2)ᵒ, γ= 73.38(2)ᵒ. When cooled, the crystalline solid 11 undergoes a reversible structural change. 11a is polymeric in nature, with bridging between copper atoms accomplished by an oxime oxygen atom of ligand 1. 11b is best described as dimeric.
Open Access
Structural variations in metal ion complexes of the ligand EGTA⁴-
(Colorado State University. Libraries, 1985) Schauer, Cynthia Karen, author; Anderson, Oren, advisor; Elliott, C. Michael, committee member
Structural studies of several metal ion complexes with the tetraanion of the octadentate ligand, H^4EGTA (3,12-bis(carboxymethyl)-6, 9-dioxa-3, 12-diazatetradecanedioic acid), as well as the structure of H^4EGTA, have been performed by single crystal X-ray diffraction. Of particular interest was the structural basis for the large preference for EGTA^4- to bind calcium ion rather than (K(CaL^2-) ~= 10^6 magnesium ion = 10^6 (K(MgL^2-)), a preference which is similar to that exhibited by intracellular calcium binding proteins. The alkaline earth compounds, Ca[Ca(EGTA)]·(22/3)H2o, Sr[Ca(EGTA)] ·6H2O, Mg[Sr(EGTA)(OH2 )]·7H2o, Mg(Ba-(EGTA)]·(8/3)H2O·(1/3) (CH3) 2CO, and (Mg2(EGTA)(OH2 )6]·5H2O, have been structurally characterized. [Ca(EGTA)]2- is eight-coordinate and utilizes the full octadentate chelating capability of the EGTA^4- ligand. The ether oxygen atoms are bound at a shorter distance than the amine nitrogen atoms. EGTA^4 - is octadentate toward both the strontium and barium ions, which are nine- and ten-coordinate, respectively. The magnesium complex is dinuclear, utilizing each end of the EGTA^4- ligand as a tridentate iminodiacetate ligand; the ether oxygen atoms are not involved in coordination to the metal ion. Structures of EGTA^4 - chelates of metal ions that are commonly used as spectroscopic probes for calcium ion binding sites have also been determined. The cadmium chelate in Sr[Cd(EGTA)]·7H2 o is eight-coordinate, li k e [Ca(EGTA)]^2 -, but the amine nitrogen atoms are bound at shorter distances than the ether oxygen atoms. The metal ions in the structures of tripositive lanthanide ion complexes, Ca[Er(EGTA)(OH2)]2·12H2O and Ca[Nd(EGTA)- (OH 2 )]2·9H2O, are nine- and ten-coordinate, respectively. To further explore coordination modes of the EGTA^4 - ligand with smaller metal ions, where the ligand is not likely to be octadentate, structures of manganese and copper complexes of were determined. Sr[Mn(EGTA)] ·7H2O is isomorphous with the cadmium compound. As a result, the Mn(II) ion is eight-coordinate. The copper complex crystallizes as a dinuclear species, [CU2(EGTA)(OH2)2] ·2H2O, in which each end of the EGTA^4- ligand binds a copper(II) ion in a tetradentate fashion; the ether oxygen atom is bound in the apical position of the square pyramidal coordination sphere.
Open Access
Epidemiology of reported scrapie in the United States: 1947-1991
(Colorado State University. Libraries, 1993) Wineland, Nora E., author; Salman, M., advisor; Kimberling, Cleon V., committee member; Gould, Daniel H., committee member; Weber, Stephen, committee member
Data collected in support of the United States Department of Agriculture (USDA) scrapie eradication program between 1947 and September 30, 1991 were evaluated to determine the presence of trends or patterns which might help further the understanding of natural sheep scrapie. The USDA records from 957 confirmed positive cases of natural scrapie in 581 flocks from 39 states were reviewed and compiled into a database. Possible host and management risk factors for scrapie such as age at death, within-flock mortality, breed, sex, sire and dam disease status, flock size, and location were examined. There were several significant findings from the study. The proportion of reported positive flocks in those states reporting positive cases showed a steady increase between 1965 and 1991. In addition, the average flock mortality showed a slight increase between 1947 and 1991. These increases did not seem to be directly related to any changes in the USDA eradication program. The average age at death for confirmed cases was 43.6 months. Rams died of scrapie an average of five months younger than did the ewes. This difference was statistically significant, but likely due to the small numbers of rams included in the study. There were insufficient numbers of twins (26 pairs) to allow any significant conclusions to be drawn. There were no statistically significant differences between age at death for the eight geographical regions or the various sheep breeds affected. The Suffolk breed comprised 88% of the reported cases, and Hampshire sheep accounted for 6% of the cases. Attempts were made to further define the role of vertical transmission in natural scrapie. The scrapie disease status of the sire had no appreciable effect on the age of death of positive offspring. The scrapie disease status of the dam had a detectable effect with positive offspring from positive dams diagnosed at a significantly younger age than positive offspring from other dams. Unfortunately it was not possible to determine when a positive dam might begin shedding the scrapie agent and consequently present a threat to her offspring. All of the positive dams in the study gave birth to their positive offspring in flocks where there were other active cases of scrapie which might have been the source of infection for the offspring. The source of infection could not be determined for over half of the reported cases. Several possible explanations for this situation were presented. Failure to detect the sources of infection may in part be responsible for the apparent increase in the magnitude of the scrapie problem in the United States. Data quality and consistency was a major issue for this study. The records available from the technical program staff of USDA contained varying amounts of information about each of the positive animals and flocks. In addition to variation in the records, the eradication program itself went through several phases during the study period. These different phases may have had multiple effects on the levels of disease reported to USDA. Unfortunately these effects could not be measured or corrected for in the analysis.
Open Access
Archaeological investigations of high altitude sites near Monarch Pass, Colorado
(Colorado State University. Libraries, 1990) Hutchinson, Lewis A., author; Eighmy, Jeffrey, advisor; Benedict, James B., committee member; Leyendecker, Liston, committee member
The tundra and upper forest border north of Monarch Pass. in the central Colorado Rocky Mountains. contains a cluster of twelve sites. One of the sites. Water Dog Divide Game Drive, is an extensive system of rock alignments and associated hunting blinds. This site and other smaller systems in the Monarch site area are at present the southernmost documented examples of prehistoric timberline game drives along the Continental Divide. Cultural materials include projectile points. other flaked tools, groundstone and a broken ceramic vessel. Temporal periods indicated are 3000 B.C. to the historic. Two hunting blinds were excavated and three radiocarbon dates were obtained with corrected dates ranging from 900 A.D. - 1640 A.O. Four of the rock walls in the largest drive site contain a number of remnant wooden posts or sewels apparently used to help delineate the rock walls. It is hypothesized that the area was utilized on a seasonal basis to camp and communally hunt large game animals (bison, mule deer, elk. and mountain sheep). The sites may have been visited by peoples from the Plains. Great Basin. and Southwestern culture areas.
Open Access
Genetic relationships between sex-specific traits in a crossbred beef cattle population
(Colorado State University. Libraries, 1993) Speer, Nevil, C., author; Brinks, James S., advisor
Data used were obtained from the Fort Keogh Livestock and Range Research Laboratory (LARRL), Miles City, Montana. Data were from a crossbreeding experiment involving Hereford, Angus and Charolais cattle collected from 1962 to 1977. Traits studied and considered separate with respect to sex, included male and female birth weight (BWM and BWF), weaning weight (WWM and WWF), and postweaning average daily gain (ADGM and ADGF). Other traits studied were average adjusted mature weight (MW) of cows and fat thickness (FT), ribeye area (REA), yield grade (YG), quality grade (QG) and days on feed (DOF) of bulls and steers slaughtered at a weight constant endpoint of 1000 - 1050 lb. Multi-trait sire-maternal grandsire REML analyses were performed on straightbred and crossbred Hereford, Angus, and Charolais cattle. Observations on 2888 animals contributed to development of the A-inverse which represented relationships among 138 sires and maternal grandsires. Models for BWM, BWF, WWM, WWF, ADGM, ADGF, and MW analyses models included birth year, age of dam (2, 3, 4, 5+) and linear regression on weaning age. The DOF analysis model included birth year, age of dam, sex of calf (bull vs steer), age of dam-sex of calf interaction and linear regression on weaning age. Carcass trait (FT, REA, YG, QG) models included birth year, age of dam, sex of calf, age of dam-sex of calf interaction and linear regression on carcass weight. Linear regressions on individual breed percentage, combined reciprocal cross percentage (individual heterosis), dam breed percentage and dam combined reciprocal cross percentage (maternal heterosis) were also included in all models for analyses of all traits of interest. Correlations between direct components of birth weight, weaning weight, and postweaning average daily gain considered separately between male and female calves were .93, .90 and .74 respectively. The correlation between direct components of MW and DOF was -.66. Correlations between direct components of MW and carcass traits were -.54, -.18, -.18, and .41 for FT, REA, YG and QG, respectively. Correlations between maternal components of birth weight, weaning weight, and postweaning average daily gain considered separately between male and female calves were .86, .98 and .42, respectively. The correlation between maternal components of MW and DOF was -.71. Correlations between maternal components of MW and carcass traits were .40, .10, .08, and -.06 for FT, REA, YG and QG, respectively. Correlations between mat-dir and dir-mat of the same traits studied were moderate and ranged from -.44 to .47. Predictions of correlated responses in mature weight per standard deviation of direct response in male carcass traits were -32 lb, -13 lb, -10 lb, and 31 lb respectively for FT, REA, YG and QG. Correlated response predictions indicate selection for improved carcass cutability on a weight constant basis (increased leanness and decreased yield grades) would increase mature weight while selection for increased ribeye area and decreased quality grade scores (favorable) on a weight constant basis would result in decreased mature weights of females. Strong selection pressure for leanness may be antagonistic to commercial beef producers since results suggest sires selected on the basis of reducing fat in steer progeny also produce females that are larger at maturity when cattle are slaughtered at a constant weight endpoint. It should be noted, however, relationships between carcass traits and mature weight may differ when cattle are slaughtered at a constant age endpoint.
Open Access
Sequence stratigraphic framework for top seal development: examples from the Skull Creek and Graneros shales, Denver basin
(Colorado State University. Libraries, 1999) Edwards, Kimberly, K., author; Sutton, Sally J., advisor; Ethridge, Frank G., advisor; Almon, William R., committee member
In general, the distal open marine shelf setting, typified by the Graneros Shale produces a rock with a greater and more uniform seal capacity relative to the rocks of a proximal open marine shelf setting, such as those of the Skull Creek Shale. A distal setting, which usually corresponds to the time of maximum transgression, may produce better seals because there is less coarse clastic sediment input, which allows slow deposition of clays from suspension to be the dominant depositional process. In this study, the higher capacity seal rocks occur in the upper parts of the TST, either within the condensed section or below it. The Skull Creek locations show seal occurrence to be stratigraphically higher on depositional topographic highs, and lower in areas that were topographically low at the time of deposition. Top seal capacity was quantified with mercury injection capillary pressure (MICP) analysis. Other physical characteristics of these marine shales were studied but only porosity, permeability, total clay, and hydrogen index consistently demonstrated a significant correlation with seal capacity in both units. Shales that are well laminated with a high percentage of total clay and/or total organic carbon with a type I-II (marine) kerogen may or may not qualify as the best seal. Top seal capacity may be more a function of rock fabric rather than mineralogy. For example, two samples may have exactly the same amount of quartz, as shown by XRD analysis, but thin section examination reveals that the majority of quartz in one sample is present as grains and in the other sample as cement. Samples with cement usually provide a better seal because they decrease the pore throat diameter, thus increasing the amount of hydrocarbons that can be trapped. Seal quality in both the Skull Creek and Graneros Shales is quite variable throughout each of the facies within the TST deposits.
Open Access
Influence of abiotic and biotic factors on the response of benthic macroinvertebrates to metals
(Colorado State University. Libraries, 1995) Kiffney, Peter Michael, author; Clements, Will, advisor; Fausch, Kurt D., committee member; Kondratieff, Boris C., committee member; Chapman, Phillip, committee member
Stream ecologists are well aware that chemical, biological, and physical characteristics of lotic systems vary spatially and temporally. With this in mind, I designed a series of experiments and field studies to examine the role of spatial variation in stream benthic macroinvertebrate communities in response to metals. Specifically, I tested the hypothesis that stream invertebrate communities from pristine streams of different size and altitude varied in their response to metals. To evaluate how metals affected biotic interactions, I manipulated invertebrate density, predation intensity, and metals in stream microcosms. Using stream invertebrate communities, I also designed an experiment and field survey to identify reliable bioindicators of metal contamination in western streams. Results from microcosm experiments and field studies showed that benthic invertebrate populations from high-altitude streams were more sensitive to the effects of metals than invertebrate populations from low-altitude streams. For example, Baetis sp. and Rhithrogena hageni from Little Beaver Creek (LBC), Colorado, (high-altitude stream) were significantly more sensitive to zinc than the same species from the South Fork of the Poudre River (SFP) (low-altitude stream) in stream microcosms. Results from field surveys showed that densities of most groups of aquatic insects (e.g., Ephemeroptera, Plecoptera, Trichoptera) were lower at high-altitude metal contaminated streams than those same groups at low-altitude streams. Other factors, such as variation in water temperature or nutrient concentrations between high- and low-altitude streams, could be lll responsible for these differences. However, because invertebrate responses were similar under controlled and field conditions, I hypothesize that differences in abundances between reference and contaminated locations was a result of metals. To determine if body size contributed to the variation in sensitivity of insects to metals, size measurements were made on species collected from LBC (high-altitude) and SFP (low-altitude). Measurements were also made on species from control and metal-treated stream microcosm. Most species were smaller at LBC (high-altitude stream) than the same species from SFP (low-altitude stream). For example, the mayfly Baetis tricaudatus and the caddisfly Arctopsyche grandis were significantly larger at SFP than LBC. In addition, insect body size was larger in metal-dosed microcosms than in controls. Brachycentrus sp., B. tricaudatus, R. hageni, Eohemerella infrequens, and P. badia were significantly larger in metal-treated microcosms than in controls. Logistic regression indicated survival in metal-dosed microcosms was less for small individuals than for larger individuals of the same species. These results suggest that some insect species from high-altitude streams were smaller than those from low-altitude streams, and that survival was greater for larger lifestages. Thus the variation in response of macroinvertebrates between different altitude streams observed in earlier studies may be due to differences in body size. The effects of low levels of metals (half the chronic levels of Cd, Cu, and Zn) on some species varied in relation to invertebrate density (low and high density) and invertebrate predation (no predators added and predators added). The abundance of Hydropsyche sp. was significantly lower in metal-dosed, high density treatments than in control, high density treatments. Moreover, the effects of an invertebrate predator (Hesperoperla pacifica) on Hydropsyche sp. was significantly greater in metal-dosed microcosms than in controls. These results suggest that metals interact with biotic factors to influence stream invertebrate community structure, and that effects occurred at metal concentrations lower than chronic criteria value. Toxicity experiments in stream microcosms showed that the abundance and species richness of aquatic insects were significantly reduced at 1x, 5x and 10x the United States Environmental Protection Agency chronic levels of cadmium, copper, and zinc (1x=1.1, 5.0, and 110 μg/L Cd, Cu, and Zn, respectively). Mayflies were the most sensitive group, as the abundance of Baetis sp. and Rithrogena hageni were significantly reduced in the Ix treatment. The response of Drunella grandis was size dependent, as small lifestages were significantly more sensitive than large lifestages. Stoneflies were also affected, but their response was more variable with abundances of some species (Pteronarcella badia) being reduced in the Ix treatment, whereas other species were unaffected (Sweltsa sp.). Heptageniid mayflies were consistently less abundant downstream of sources of metal contamination in the Arkansas and Eagle rivers, whereas the response of other measures were more variable. For instance, species richness and total density were greater at a metal-contaminated site on the Arkansas River compared with an upstream reference site. Therefore, results from this experiment and field survey suggest that changes in abundance of heptageniid mayflies may provide a reliable indicator of metal-contamination in western streams.
Open Access
5000 years at Crow's Roost in eastern Colorado
(Colorado State University. Libraries, 1992) McDonald, Robert A., author; Jennings, Calvin H., advisor; Leyendecker, Liston, committee member; Zier, Christian, committee member; Theodoratus, Robert, committee member
Many areas on the high Plains of eastern Colorado have had little prehistoric research conducted on them. One of the areas where there is insufficient information about local prehistory is the area between the two major river drainages, the Arkansas and the Platte. Crow's Roost, a large sandstone cliff, located east of Colorado Springs, Colorado, is situated near this dividing line, known as the Palmer Divide. A series of prehistoric sites at Crow's Roost has been investigated over a period of five years by the Anthropology Department, University of Colorado at Colorado Springs. These investigations indicate that there has been prehistoric occupation at this locality dating back at least 5400 years. This study presents an interpretation of the culture history, and of recent paleoclimatic fluctuations for this locality.
Open Access
The bighorn sheep of Battlement Mesa - a low elevation population
(Colorado State University. Libraries, 1991) Cunningham, Mary Louise, author; Bailey, James A., advisor; Alldredge, A. William, committee member; Lehner, Philip N., committee member
I studied bighorn sheep on Battlement Mesa, Colorado, from 12/88 to 7/90, to determine present and past herd status and distribution, so that 1) management options are clarified and 2) future management activities may be evaluated. I studied the herd by tracking 1 radio-collared ewe and obtaining visual observations and by systematically sampling study area units for sheep, sheep sign, potential competitors, potential predators and sheep carcasses. I recorded water sources that were encountered. I developed an historic perspective of the herd by searching agency files and local newspapers and interviewing local residents. The herd numbered up to 200-250 animals in the early 1900s and declined to an estimated 50 animals by 1970. Minimum herd sizes during 1989 and 1990 were 23 and 26, including lambs, respectively. Since 1961, the herd has abandoned approximately 56 km2 of historic range in the Mamm Peaks area. The herd decline corresponded with probable vegetation changes on Battlement Mesa, intensive livestock grazing through the 1950s, reports of poaching and an increasing elk herd. Sheep remained on the western portion of the range during winter and spring, 1989. Ewe/juvenile groups migrated to Anderson and Durant Gulches between 5/15-7/15/89 for lambing. Rams were more dispersed and in groups of 1-3, except during the rutting season. Ewe/juvenile group size ranged from 1-13. During dry months, (7/89, 8/89, 6/90) sheep concentrated in Anderson and Durant Gulches where a free-flowing spring and a seep were located. Bighorn sheep on Battlement Mesa appear limited by dense mountain shrub stands which separate all productive meadows from escape terrain and cover historic migration routes. A significantly greater use of the shale slope habitat contributed most to rejecting the null hypothesis that sheep use habitat types in proportion to their availabilities on Battlement Mesa. Sheep remained on shale slopes most (75% of all observations) of the time, using scattered grasses, forbs and shrubs for forage and seeps for water. Intensive and long term habitat management for bighorn sheep on Battlement Mesa is required. I suggest a 4-phase management program to improve existing range and later to reestablish and maintain historic migration corridors to productive historic summer range. Without management to improve existing conditions, this small, unique herd will remain static or decline.