Showing papers by "Colorado State University published in 1980"

Chronic wasting disease of captive mule deer: a spongiform encephalopathy.

Abstract: In the past 12 years (1967–79) a syndrome we identify as chronic wasting disease has been observed in 53 mule deer (Odocoileus hemionus hemionus) and one black-tailed deer (Odocoileus hemionus columbianus) held in captivity in several wildlife facilities in Colorado and more recently in Wyoming. Clinical signs were seen in adult deer and included behavioral alterations, progressive weight loss and death in 2 weeks to 8 months. Gross necropsy findings included emaciation and excess rumen fluid admixed with sand and gravel. Consistent histopathologic change was limited to the central nervous system and characterized by widespread spongiform transformation of the neuropil, single or multiple intracytoplasmic vacuoles in neuronal perikaryons and intense astrocytic hypertrophy and hyperplasia. Presented is a clinical characterization of chronic wasting disease and pathologic evidence supporting the conclusion that the disease is a specific spontaneously occurring form of spongiform encephalopathy.

Toxicology of selenium: A review

Abstract: (1980). Toxicology of selenium: A review. Clinical Toxicology: Vol. 17, No. 2, pp. 171-230.

A Numerical Investigation of Several Factors Contributing to the Observed Variable Intensity of Deep Convection over South Florida

Abstract: This study employs a revised version of the Colorado State University three-dimensional numerical cloud scale model to investigate the observed behavior of deep convection over South Florida on 17 July 1973. A brief description of recent model improvements is made. A combined balance and dynamics initialization procedure designed to introduce variable magnitudes and distributions of low-level wind convergence to the initial fields is described. Using radiosonde and PIBAL data collected by the NOAA/ERL Florida Area Cumulus Experiment (FACE) and the National Weather Service at Miami on 17 July 1973, composite wind, temperature, pressure and moisture profiles were constructed to depict the state of the atmosphere at the time of deep convection. Mesoscale convergence was estimated from results of a mesoscale model simulation of low-level sea breeze convergence made by Pielke (personal communication) for the same case study day. Several numerical simulations were performed using the sounding data as a...

Psychometric properties of self-appraisals of job performance

Abstract: This paper reviews literature of psychometric properties of self-appraisals of work performance. It summarizes evidence of leniency, variability, halo, bias, and construct validity. Comparisons with appraisals by supervisors, peers, and subordinates suggest that self-appraisals tend to show more leniency, less variability, and less discriminant validity. Different factor structures have been found among self, supervisor and peer-ratings. On the other hand, self-appraisals showed less halo. Self-appraisals were significantly correlated with other sources in some studies and failed to correlate in many others. Existing data do not allow any conclusion whether the quality of self-appraisals is a function of scale format, amount or rater training, type of judgment, or purpose of appraisal. The effects of the observed psychometric qualities of self-appraisals on various applications are discussed. Problems may exist when they are used for administrative decision making, diagnosis of training needs, applied criterion measurement, measurement of constructs in basic research, or for selection purposes.

Occurrence of hydroxamate siderophore iron chelators in soils

Abstract: Although iron is abundant in soils (1–6%), it is often unavailable to plants because its solubility is dependent on pH and controlled by the low solubility of ferric oxides. Iron availability to plant roots may thus depend on organic chelators which Lindsay reports would maintain an adequate iron supply by diffusion and mass flow at concentrations as low as 10−8 M1,2. Hydroxamate siderophores (HS), microbially produced, ferric-specific, iron transport molecules with stability constants3 as high as 1032, may represent the chelators which maintain these soil iron concentrations. Such peptide derivatives were shown to control iron availability in aquatic ecosystems4, but little is known about their soil role beyond their function as microbial growth factors5,6. We report here the occurrence of HS in aqueous extracts of a variety of soils in concentrations (10−7 M–10−8 M after correction to 10% soil moisture) sufficient to affect plant nutrition1,2.

A nitric acid plant tissue digest method for use with inductively coupled plasma spectrometry

Abstract: A wet digestion method for plant tissue analysis for use with Inductively Coupled Plasma ‐ Atomic Emission Spectrometry has been developed. This procedure uses only nitric acid and eliminates the use of perchloric acid and subsequently eliminates the danger of HClO4. explosions, and the problem of KClO4 precipitation. Analysis of National Bureau of Standards plant materials ‐ orchard, tomato, and spinach leaves ‐ digested with nitric‐perchloric acid or nitric acid compared very well with the NBS certified values. The analytical results for eight other plant species were comparable for the two methods of digestion. A summary of the recommended procedure for use with ICP is given below: 1. Weigh 0.5 to 1.0 g of plant tissue into a 50 ml Taylor tube. 2. Add 10 ml conc, nitric acid. Let stand overnight. 3. Heat samples at 125° C for 4 hours. Let cool. 4. Dilute to 12.5 ml with conc, nitric acid. Dilute to 50 ml with distilled water. Mix and let amorphous silica settle. 5. Aspirate directly into plasm...

Biomechanics of vegetative channel linings

Abstract: A method to determine and apply the biomechanical properties of vegetative channel linings is presented. The method is used to evaluate the stiffness of vegetation commonly used to protect earth channels from erosion. Using the vegetation stiffness and stem length, the deflected height of the channel lining is predicted to yield a relative roughness under given flow conditions. The relative roughness is used to calculate a value of the Darcy-Weisbach friction factor or Manning's n. A method to design a vegatated channel is included.

Cereal sprouts: composition, nutritive value, food applications

Abstract: The practice of sprouting of cereal grains has become popular in the western world. Sprouted grains are thought of as having exceptional nutritive value. Sprouting is easy and can be done without sophisticated equipment. Untreated seeds of good quality and high germination percentage are placed in an environment of adequate water, a desirable temperature, and a certain composition of gases in the atmosphere for several days for sprouting. The sprouts can be kept for a few days to over a week under refrigeration. They can be used in many different foods including breakfast items, salads, soups, casseroles, pasta, and baked products. Sprouting of grains causes increased enzyme activity, a loss of total dry matter, an increase in total protein, a change in amino acid composition, a decrease in starch, increases in sugars, a slight increase in crude fat and crude fiber, and slightly higher amounts of certain vitamins and minerals. Most of the increases in nutrients are not true increases, however. They simply reflect the loss of dry matter, mainly in the form of carbohydrates, due to respiration during sprouting. As total carbohydrates decreases, the percentage of other nutrients increases. There are no nutritional evaluations of cereal sprouts in humans. Animal studies with cattle, pigs, chickens, and rats have failed to show a superior nutritive value of sprouted grains over ungerminated grains. Studies with humans are not likely to produce more encouraging results.

Detrital processing and associated macroinvertebrates in a Colorado mountain stream

Abstract: Investigation of leaf litter processing in a Colorado mountain stream revealed that processing of alder (Alnus tenuifolia), willow (Salix hebbiana), and aspen (Populus tremuloides) occurred at rapid rates despite water temperatures at or near 00C. Pine (Pinus ponderosa) was pro- cessed much more slowly. The loss rate coefficient (k) ranged from .0038 for pine to .0308 for alder. The high biomass of shredders per gram of leaf pack is a likely explanation for the rapid processing. Whereas a few large shredders per leaf pack are generally characteristic of eastern woodland streams, a large number of small-sized shredders (Capnia and Zapada) colonized leaf packs in the Colorado mountain stream. The numbers and biomass of collectors per leaf pack were directly related (P < .01) to the ash-free dry mass of fine organic particles (75-1000 ,um) indicating the importance of fine particulate organic matter in determining the suitability of leaf litter as habitat for fine particle-feeding detritivores.

How Nutcrackers Find Their Seed Stores

Abstract: -The Clark's Nutcracker (Nucifraga columbiana) stores conifer seeds in the late summer and fall of each year. During winter and spring, seeds from buried caches are the major food of nutcrackers and their young. A bird must find more than a thousand seed caches each year. The alternative means by which nutcrackers may locate seed stores are (1) memory of cache site and (2) trial and error search. While searching for stored seeds, a Clark's Nutcracker makes a series of prod holes with its bill. A hole from which a cache was recovered is usually distinguished by a pile of broken seed coats. This allows an estimate of a nutcracker's success rate in locating seed caches. Theft of seed caches by rodents and removal of intact seeds from cache sites by nutcrackers may confuse this estimate. A field technique based on deductive reasoning is presented to determine how nutcrackers recover their caches. In the eastern Sierra Nevada I gathered field data on the success rate and nearest neighbor distances among prod holes in spring and summer of 1975. Data indicating the proportion of caches taken by rodents were obtained in 1978. Analyses of these data suggest that nutcrackers find most of their caches by means of memory. A search based on memory implies that seed stores are not communal and that nutcrackers must remain in the area where they stored seeds until the following summer. Theft of seed stores by rodents must be an important selective pressure on nutcracker caching behavior. By caching seeds in storage areas which become covered with deep snow, nutcrackers may reduce their losses to rodents. Many birds of the family Corvidae store food for future use. Food storage is a major event in the annual cycles of the genera Garrulus, Aphelocoma, Gymnorhinus and Nucifraga (Tur6ek and Kelso 1968). Both species of Nucifraga, Clark's Nutcracker (N. columbiana) and the Eurasian Nutcracker (N. caryocatactes), store conifer seeds in late summer and fall (Bibikov 1948, Reimers 1953, Kuznetsov 1959, Vander Wall and Balda 1977, Tomback 1977a). These stores are the major food of the nutcrackers from winter to mid-summer (Kuznetsov 1959, Mezhenny 1961, Holtmeier 1966, Tomback 1977a). Both species breed in early spring, raising young almost exclusively on stored seeds (Mewaldt 1956, Swanberg 1956, Reimers 1959a). Stores made by nutcrackers consist of many small clusters of seeds hidden in a variety of sites throughout the montane habitat (Bibikov 1948, Swanberg 1951, Reimers 1959b, Kishchinskii 1968, Tomback 1977a). I will use the term "cache" to denote one cluster of seeds; seed stores consist of many caches. The means by which a nutcracker finds these stored seeds has not been satisfactorily explained and remains an intriguing problem in animal behavior. The most direct approach to this problem would be xperimentation on captive birds under controlled conditions. R. P. Balda (in press) recently concluded a series of controlled investigations of seed recovery behavior in the Eurasian Nutcracker. His findings concur with previous field observations (Swanberg 1951, Mezhenny 1964, Crocq 1977, Mattes 1978) and also present new information. However, it is possible that the limited space and predictable stimuli of experimental enclosures can bias results. Before similar experimental work is undertaken on the Clark's Nutcracker, confirmation of laboratory findings with field data is desirable. In this paper I present the results of a field investigation of how Clark's Nutcrackers recover their seed stores. THE NATURE OF THE PROBLEM Vander Wall and Balda (1977) calculated that a single Clark's Nutcracker may store between 22,000 and 33,000 pifion pine seeds (Pinus edulis) in the late summer and fall of each year in northern Arizona. This qua tity represents between 2.2 and 3.3 times the energetic requirement of the nutcracker. I calculated (Tomback 1977b, unpubl. data) that each year in the eastern Sierra Nevada one Clark's Nutcracker may store as many as 32,000 whitebark pine

A model for the computer analysis of synchronous DNA distributions obtained by flow cytometry

Abstract: A new model for obtaining the distributions of cells in the cell cycle by computer analysis of flow cytometry data is proposed. The model is able to analyze distributions from both asynchronous and synchronous cell populations. A culture of HeLa cells is pulse-labeled with tritiated thymidine at various times after synchronization by the mitotic selection method, then analyzed by flow cytometry and autoradiography. The results show good agreement between the percentage S-phase cells determined by the model and by autoradiography.

Confidence Intervals on Nonnegative Linear Combinations of Variances

Abstract: Smith (1936) suggested a method that can be used for setting confidence limits on linear combinations of variances. This method was studied and expanded by Satterthwaite (1941, 1946) and has become known as Satterthwaite's procedure. The procedure has been widely used for the past 40 years. In this article a new procedure is proposed for this problem that is better than Satterthwaite's procedure and very easy to compute from existing tables.

Initial solar irradiance determinations from nimbus 7 cavity radiometer measurements.

Abstract: Preliminary results from solar radiation measurements from the earth radiation budget experiment on the Nimbus 7 satellite yield a mean value of 1376.0 watts per square meter for the "solar constant" from 16 November 1978 to 15 May 1979. The observed variability (root-mean-square deviation) is +/- 0.73 watt per square meter (+/- 0.05 percent) for the period.

A Simple Asymptotic Estimate for the Index of a Stable Distribution

Abstract: SUMMARY A simple asymptotic estimate is constructed for the index of a stable distribution based on order statistics from a distribution in its domain of attraction. The asymptotic distribution of the estimate is then found in case the order statistics are taken from the stable distribution itself.

On the physics and modeling of small semiconductor devices—I

Abstract: Current LSI technology has progressed rapidly and is pushing toward fabrication of sub-micron dimensioned devices. Several authors have previously used static characteristics, power dissipation, noise, and packing density to look at limiting properties of small devices, although the actual device physics was not considered in detail. As devices become smaller, we expect that the temporal and spatial scales in these devices become sufficiently small that the semi-classical approach to transport theory, as expressed by the Boltzmann transport equation, becomes of questionable validity. In this paper, we address the question of whether our physical understanding of devices and their operation can be extrapolated to small space and time scales, and to what extent the essential quantum electronics prevents a down-scaling. We attempt to lay here a conceptual framework for an ultimate physics of small devices and the modeling necessary to characterize these devices. In this first paper, we work with a dimensional scale of l ∼ 2500 A , the medium small device, leaving a smaller scale to a subsequent work. Although this scale is marginally in a region where the semi-classical approach is valid, extensive modifications must be made to incorporate several new physical effects, including: intra-collision field effect, retarded spatial and temporal non-local effects, two-dimensional quantization, memory effects in the transport parameters, nonlinear screening/descreening, and multiple scattering effects.

The Pathomorphology of Malignant Catarrhal Fever: I. Generalized Lymphoid Vasculitis

Abstract: A histologic, ultrastructural and immunohistochemical study of the vasculitis in the rete mirabile of 18 calves with experimental and two calves with spontaneous malignant catarrhal fever showed le...

Hollow cathode metal ion lasers

Abstract: A new class of metal ion lasers with significant CW output power in the UV (220-320 nm) and near IR (800-2000 nm) spectral regions is described. In a hollow cathode discharge the upper laser levels are excited via charge transfer collisions between ground state buffer gas ions and ground state metal atoms. At the present stage of development, hollow cathode metal ion lasers are shown to be comparable in UV output power to rare-gas ion lasers but with lower threshold currents by a factor of more than twenty. Visible output powers are lower than rare-gas ion lasers. In the text we present device progress to date, measurements of important plasma parameters, and an outline of potential applications of hollow cathode metal ion lasers.

Geostrophic Adjustment in an Axisymmetric Vortex

Abstract: A linearized system of equations for the atmosphere's first internal mode in the vertical is derived. The system governs small-amplitude, forced, axisymmetric perturbations on a basic-state tangential flow which is independent of height. When the basic flow is at rest, solutions for the transient and final adjusted state are found by the method of Hankel transforms. Two examples are considered, one with an initial top hat potential vorticity and one with an initial Gaussian-type potential vorticity. These two examples, which extend the work of Fischer (1963) and Obukhov (1949), indicate that the energetical efficiency of cloud-cluster-scale heating in producing balanced vortex flow is very low, on the order of a few percent. The vast majority of the energy is simply partitioned to gravity-inertia waves. In contrast the efficiency of cloud-cluster-scale vorticity transport is very high. When the basic state possesses positive relative vorticity in an inner region, the energy partition can be subst...

Soil Temperature Influences on Root Resistance of Pinus contorta Seedlings.

Abstract: The influence of low temperature in the root zone on water uptake in lodgepole pine (Pinus contorta Dougl. ex Loud.) was studied under laboratory conditions. To remove soil hydraulic influences, two-year-old seedlings were transferred to solution cultures and maintained in temperature controlled water baths. Short term measurements of leaf conductance, leaf water potential and tritiated water movement were taken at root temperatures from 22 C down to 0 C. Root resistance was calculated to be 67% of total plant resistance at 7 C and 93% at 0 C. In addition an Arrhenius break was found in a plant resistance versus temperature plot, suggesting a significant change with temperature in the membrane pathway in the root water uptake system.

A comparison of the behaviorally anchored rating and mixed standard scale formats.

Abstract: Compared the behaviorally anchored rating (BAR) and mixed standard scale (MSS; F. Blanz and E. E. Ghiselli, see record 1974-04034-001) formats in terms of the multitrait-multimethod validity they engendered in rating scales. Rating scales were developed with the retranslation of expectations (RE) pr

The Electrochemical Behavior of Aluminum in the Low Temperature Molten Salt System n Butyl Pyridinium Chloride: Aluminum Chloride and Mixtures of This Molten Salt with Benzene

Abstract: The aluminum deposition and stripping processes at tungsten, platinum, and glassy carbon electrodes in the low temperature molten salt system, n butyl pyridinium chloride: aluminum chloride, and the 50 volume percent (v/o) mixture of this molten salt with benzene have been investigated, using a variety of electrochemical techniques. At all three electrodes, and in both solvent systems, the deposition reaction in slightly acidic melts, the reduction of ions, was found to involve a nucleation process while at the tungsten and platinum electrodes underpotential deposition was also observed. Reduction of the n butyl pyridinium cation was found to occur at −1.1V vs. Al(2:1 melt) which is positive of the reduction potential of ions and therefore aluminum deposition in basic melts was not observable. Studies of the stripping of aluminum from inert substrates showed that aluminum is very slowly corroded in acidic melts, and melt‐benzene mixtures, by traces of oxidizing impurities while in basic systems aluminum reduces the n butyl pyridinium cation. Potentiometric titration of the 50 v/o melt‐benzene mixture showed that the acid‐base properties of this system are defined, as in the pure melt, by the equilibrium with an equilibrium constant of at 30°C.

Nitrogen and Phosphorus Dynamics and Budgets in Annual Grasslands

Abstract: N and P dynamics were studied in a grassland ecosystem dominated by exotic annual plants in central California. Biomass and N and P concentrations were observed over a 3-yr period for the dominant grasses, forbs, and legumes and plant residues (litter). The N and P contents were determined or estimated for various components of the ecosystem (e.g., live tops, live roots, soil organic matter, dead roots, litter, microflora, soil fauna, mineral N, solution P, and labile inorganic P). We estimated that >57, 125, and 89 kg/ha of N and 13.1, 14.7, and 14.1 kg/ha of P were mineralized during the 1972-1973, 1973-1974, and 1974-1975 growing seasons, respectively. However, N uptake by plants was 119, 87, and 68 kg/ha and P uptake was 13.1, 14.5, and 10.4 kg/ha, respectively. While the data showed that P was stable, indicating its cycle was relatively closed, the data of N showed that its cycle was open, with large inputs of N from symbiotic fixation the 1st yr of the study. Large losses of N from the system were estimated.

Evolution of the Cleidoic Egg Among Reptilian Antecedents of Birds

Abstract: Evolution of the avian egg from the naked amniotic egg of ancestral reptiles probably was the outcome of intense predation by soil invertebrates and microbes on a highly integrated and coadapted complex of characters. The calcareous shell which from its inception afforded a measure of protection to eggs against attacks by soil organisms became progressively thicker and more complex in the face of continuing selection for antipredator devices. However, increases in thickness and complexity of eggshells led to simultaneous reductions in the amount of liquid water that could be absorbed by incubating eggs from the substrate. Because embryos initially were dependent upon uptake of substantial quantities of water from the environment to satisfy their needs for this solvent, adaptive increases in thickness of the eggshell required coupled increases in the amount of water contained by eggs at oviposition, thereby reducing the degree of dependence of embryos upon external sources of water for successful completion of development. The rigid-shelled eggs resulting from this evolutionary sequence absorbed little (if any) liquid water during incubation, and the eggs contained sufficient water at oviposition to sustain embryos to hatching. Such eggs were functionally cleidoic and had attained an avian level of organization.