Showing papers by "Colorado State University published in 1986"

The Palladium‐Catalyzed Cross‐Coupling Reactions of Organotin Reagents with Organic Electrophiles [New Synthetic Methods (58)]

Abstract: The cross-coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. Because this mild, versatile reaction is tolerant of a wide variety of functional groups on either coupling partner, is stereospecific and regioselective, and gives high yields of product, it is ideal for use in the synthesis of elaborate organic molecules. When the coupling reaction is carried out in the presence of carbon monoxide, instead of a direct coupling, carbon monoxide insertion takes place, stitching the two coupling partners together and generating a ketone.

Hydraulic Conductivity and Diffusivity: Laboratory Methods

Abstract: This chapter describes several laboratory methods of determining the hydraulic conductivity and hydraulic diffusivity. Water moves through soil in response to various forces acting upon it. The chemical species water may be transported due to bulk movement of the liquid phase or soil solution, or it may be transported by diffusion relative to the mean motion of the liquid phase. The chapter deals with bulk movement, under isothermal conditions, of the liquid phase in response to mechanical driving forces. However, the transport of water in the gas phase by vapor diffusion will be included in the measured hydraulic conductivity and diffusivity, especially at low water contents. The concept of parameter identification has been applied to the determination of the parameters in the hydraulic conductivity and water retention functions. The method involves the measurement of some aspect of the response of a soil water flow system to a set of applied boundary conditions.

Palladium-katalysierte Kupplungsreaktionen organischer Elektrophile mit Organozinn-Verbindungen

Abstract: Palladium-katalysierte Kupplungsreaktionen von Organozinn-Verbindungen mit unterschiedlichsten organischen Elektrophilen sind eine relativ neue Methode zur Knupfung von Kohlenstoff-Kohlenstoff-Bindungen. Da sie unter milden Bedingungen ablauft und eine Vielfalt funktioneller Gruppen an jedem der beiden Reaktionspartner ermoglicht, daruber hinaus stereospezifisch, regioselektiv und in hohen Ausbeuten verlauft, eignet sie sich ideal fur die Synthese komplizierter organischer Verbindungen. Wird die Kupplungsreaktion in Gegenwart von Kohlenmonoxid ausgefuhrt, so findet eine Verknupfung der beiden Reaktanten unter Kohlenmonoxid-Insertion statt, so das man Ketone erhalt.

Crystal data for high-pressure phases of silicon

Abstract: X-ray-diffraction data have been obtained on Si in a diamond anvil cell to pressures of \ensuremath{\sim}50 GPa. Crystallographic data are presented in phase I (cubic, diamond), II (tetragonal, \ensuremath{\beta}-Sn), V (simple hexagonal), VII (hexagonal close-packed), and the metastable phase III [body-centered-cubic (BC8)] and on the coexistence of the phases. Comparison is made between these data and the predictions of ab initio calculations for these structures and their equations of state.

Learning to Talk about Emotions: A Functionalist Perspective.

Abstract: BRETHERTON, INGE; FRITZ, JANET; ZAHN-WAXLER, CAROLYN; and RIDGEWAY, DOREEN. Learning to Talk about Emotions: A Functionalist Perspective. CHILD DEVELOPMENT, 1986, 57, 529-548. Although the recent focus on functionalist theories of emotions has led to an upsurge of interest in many aspects of emotional development, not enough attention has been paid to young children's developing ability to talk about emotions. In this paper we attempt to place what is presently known about this topic into a framework that emphasizes the intrapsychic and interpersonal functions of emotion. We also consider suggestive evidence concerning the importance of the ability to talk about emotions in the conduct of interpersonal interaction. The paper concludes with some ideas on future directions for research, placing particular emphasis on a functionalist approach to the analysis of emotion-denoting terms.

Numerical Simulation of the Effects of Varying Ice Crystal Nucleation Rates and Aggregation Processes on Orographic Snowfall

Abstract: The Colorado State University cloud model is applied to the simulation of orogrophic cloud snowfall. A model of ice crystal aggregation processes and primary nucleation and secondary ice particle production of crystals is described. Sensitivity experiments demonstrated that aggregation plays an important role in controlling the fields of cloud liquid water content, ice crystal concentrations, and surface precipitation amounts. The sensitivity experiments also support observations that the air mass is often quite clean in upper levels of stable orographic clouds. Introducing a reduction of available nuclei that can be activated by deposition/sorption processes brought concentrations to within observed values. This study clearly emphasizes the need for a great deal more fundamental research in the physics of aggregation processes and primary and secondary nucleation of ice crystals.

Peer Cluster Theory: Drugs and the Adolescent.

Abstract: The authors review several theories advanced to explain adolescent drug use to provide background for describing peer cluster theory. Peer clusters, small subsets of peer groups, including pairs, dictate the shared beliefs, values, and behaviors that determine where, when, and with whom drugs are used and the role that drugs play in defining cluster membership. Peer cluster theory incorporates those psychosocial factors that promote or inoculate against drug use in youth.

Carbon and nitrogen turnover in adjacent grassland and cropland ecosystems

Abstract: The effects of cultivation and soil texture on net and gross N mineralization, CO2 evolution and C and N turnover were investigated using paired grassland and cropped sites on soils of three textures. Gross N mineralization and immobilization were measured using15N-isotope dilution. Grassland soils had high CO2 evolution and gross N mineralization rates, and low net N mineralization rates. Cropland soils had low CO2 evolution rates but had high net and gross N mineralization rates. Grassland soils thus had high immobilization rates and cropland soils had low immobilization rates. Cultivation increased N turnover but reduced C turnover. The data suggest that the microflora in grassland soils are N limited, while those of cropland soils are limited by C availability. Increasing clay content reduced N turnover. C turnover was less clearly related to texture. Differences in the immobilization potential of substrates help explain why agricultural soils have higher N losses than do grassland soils.

Nonlinear Response of Atmospheric Vortices to Heating by Organized Cumulus Convection

Abstract: Using an axisymmetric primitive tropical cyclone model, we first illustrate the way in which nonlinear processes contribute to the development of an atmospheric vortex. These numerical experiment show that nonlinearities allow a given diabatic beat source to induce larger tangential wind (and kinetic energy) changes as the vortex develops and the inertial stability becomes large. In an attempt to gain a deeper theoretical understanding of this process, we consider the energy cycle in the balanced vortex equations of Eliassen. The temporal behavior of the total potential energy P is governed by dP/dt=H−C where H is the rate of generation of total potential energy by diabatic heating, and C is the rate of conversion to kinetic energy. We define a time-dependent system efficiency parameter as η¯(t)=C/H. Then, using the dynamical simplifications of balanced vortex theory, we express η¯(t) as a weighted average of a dynamic efficiency factor η(r, z, t). The dynamic efficiency factor is a measure of th...

Morphometric analysis of cell types in the ovine corpus luteum throughout the estrous cycle.

Abstract: The cellular composition of ovine corpora lutea obtained during the early (Day 4), mid (Days 8 and 12), and late (Day 16) stages of the estrous cycle was determined by morphometric analysis. Individual corpora lutea were collected via midventral laparotomy from a total of 19 ewes. A center slice from each corpus luteum was processed for electron microscopy and subsequent morphometric analysis of the numbers and sizes of steroidogenic and nonsteroidogenic cells. Luteal weight progressively increased throughout the estrous cycle (p less than 0.05). Corpora lutea collected on Day 16 were assigned to one of two subgroups on the basis of gross appearance and weight: nonregressed (NR, 542 +/- 25 mg) or regressed (R, 260 +/- 2 mg). There were no significant changes in the proportion of the corpus luteum occupied by small luteal cells (19 +/- 2%) or large luteal cells (36 +/- 1%) throughout the estrous cycle. The total number of steroidogenic cells per corpus luteum increased from 21.8 +/- 3.7 (X 10(6)) on Day 4 to 61.7 +/- 5.4 (X 10(6)) on Day 8 (p less than 0.05) and remained elevated thereafter. The number of small luteal cells was 10.0 +/- 2.7 (X 10(6)), 39.7 +/- 1.4 (X 10(6)), 46.1 +/- 5.8 (X 10(6)), 49.0 +/- 13.7 (X 10(6)), and 29.9 +/- 8.6 (X 10(6)) on Days 4, 8, 12, 16 (NR), and 16 (R), respectively (p less than 0.05, Day 4 vs. Days 8, 12, 16 NR). In contrast, the number of large luteal cells was 11.8 +/- 1.5 (X 10(6)) on Day 4 and did not vary significantly during the remainder of the estrous cycle. The numbers of nonsteroidogenic cell types increased (p less than 0.05) from Day 4 to Day 16 (NR) but were decreased in regressed corpora lutea (Day 16 R). Regression was characterized by a 50% decrease (p less than 0.05) in the total number of cells per corpus luteum from 243 +/- 57 ( X 10(6)) on Day 16 (NR) to 125 +/- 14 ( X 10(6)) on Day 16 (R) (p less than 0.05). Small luteal cells remained constant in volume throughout the entire estrous cycle (2520 +/- 270 microns 3), whereas large luteal cells increased in size from 5300 +/- 800 microns 3 on Day 4 to 16,900 +/- 3300 microns 3 on Day 16 (NR) (p less than 0.05). In summary, small luteal cells increased in number but not size throughout the estrous cycle, whereas large luteal cells increased in size but not number.

Disease-specific and tissue-specific production of unintegrated feline leukaemia virus variant DNA in feline AIDS

Abstract: Feline leukaemia viruses (FeLVs) have long been known to be associated with induction of proliferative and anti-proliferative diseases of domestic cats. Strains of FeLV have been recognized which specifically induce lymphosarcoma, aplastic anaemia, myelodysplastic anaemia, and, recently, feline AIDS (acquired immune deficiency syndrome), a naturally occurring immunosuppressive syndrome strikingly similar to human AIDS which is lethal in 100% of inoculated and viraemic specific-pathogen-free (SPF) cats. Here, we have analysed FeLV DNA in tissues of 22 SPF cats that had been inoculated with the feline AIDS strain (FeLV-FAIDS) and we find two classes of viral DNA--a monotypic common form which is detectable in bone marrow regardless of disease state, and variant forms, recognizable by restriction site differences, whose appearance correlates with onset of disease symptoms and persists throughout the course of the disease. FeLV-FAIDS variant DNA is detected at high concentration (10-50 copies per cell) and principally as unintegrated viral DNA (UVD) in bone marrow of cats with feline AIDS. In marked contrast high levels of UVD were not present in cats in the terminal-stages of T-cell lymphosarcoma, aplastic anaemia, or myelodysplastic anaemia induced by other FeLV strains. These results parallel recent observations in humans, where high levels of UVD were sometimes found in cells derived from AIDS patients infected with human T-lymphotropic virus type III (HTLV-III)/lymph-adenopathy-associated virus (LAV), and suggest that persistence of unintegrated variant viral DNA is a crucial indicator of retrovirus-induced cytopathic disease syndromes such as AIDS.

Two-dimensional spreads of synaptonemal complexes from solanaceous plants

Abstract: By using serial sectioning and a new hypotonic bursting technique on primary microsporocytes of tomato (Lycopersicon esculentum), relatively large numbers of recombination nodules (RNs) are observed on the synaptonemal complexes forming during zygonema. In pachynema most, but not all, of these RNs are lost. If RNs represent sites of potential crossing over during zygonema and sites of actual crossing over during late pachynema, the observed temporal and spatial distribution of RNs may provide answers for some classic cytogenetic questions such as: how is at least one crossover per bivalent assured? How are crossovers localized? What is the basis for positive chiasma interference?

Ecological relations among space, time and thermal niche axes.

Abstract: While the physical environment is often viewed as that with which an organism must contend, and the biotic environment as including resources that may be exploited, interactions occurring between the physical and biotic portions of animal niches suggest that animals also exploit their physical environments. The space and time required for physiological optimal interactions with the environment represent units with which the thermal environment can be quantified as an ecological resource. Characteristics of the thermal environment that an animal experiences within its home range have been incorporated into measures to quantify the quality of the home range with respect to temperature relations, to evaluate the importance of thermal transients to an animal, and to assess temporal aspects of habitat exploitation. Since the thermal environment is physiologically important to animals, and since there can be competition for space and time, this approach provides a bridge between physiological and population/evolutionary ecology.

Why Are There So Few Transactions among Water Users

Abstract: Water to supply growing demands from agriculture, households, and industries in the arid West traditionally has been secured through water storage and conveyance projects. Economists have been warning for years that increasing scarcity and costs of unappropriated water supplies (e.g., Wollman) together with limited public budgets and the environmental costs of new projects would shift attention to nonstructural approaches, particularly to the market mechanism, to meet emerging needs. Change, however, appears to be slow. To some observers, for example Anderson, the number of recorded instances where water supply problems are solved by market-like transactions remains far too limited.

Resonantly interacting, weakly nonlinear hyperbolic waves.II. Several space variables

Abstract: We present a systematic asymptotic theory for resonantly interacting weakly nonlinear hyperbolic waves in a single space variable. This theory includes as a special case the theory of nonresonant interacting waves for general hyperbolic systems developed recently by J. Hunter and J. B. Keller, when specialized to a single space variable. However, we are also able to treat the general situation when resonances occur in the hyperbolic system. Such resonances are the typical case when the hyperbolic system has at least three equations and when, for example, small-amplitude periodic initial data are prescribed. In the important physical example of the 3 × 3 system describing compressible fluid flow in a single space variable, the resonant asymptotic theory developed by the authors yields, as limit equations, a pair of inviscid Burgers equations coupled through a linear integral operator with known kernel defined through the initial data for the entropy wave. (In the general case we give many new conditions guaranteeing nonresonance for a given hyperbolic system with prescribed initial data, as well as other new structural conditions which imply that resonance occurs.) A method for treating resonantly interacting waves in several space variables, together with applications, will be developed by the authors elsewhere.

Ultrastructure of mouse vallate taste buds: II. Cell types and cell lineage.

Abstract: The lifespan of cells in the mouse taste bud was examined with high-voltage electron microscopic (HVEM) autoradiography (ARG) after giving a single injection of 3H-thymidine. Animals were killed at 1 hour, 6 hours, 12 hours, 24 hours, and then daily up through 10 days postinjection. Lingual tissues were prepared for HVEM ARG so that we could identify and characterize labeled cells. Four categories of taste cells were identified: basal, dark, intermediate, and light cells. Basal cells were polygonal cells located near the basolateral sides of the taste buds and were characterized primarily by the presence of filaments attached to the nuclear envelope. Dark and light cells had the typical features described by previous authors. Intermediate cells had features in between those of dark and light cells. Over 90% of the cells labeled in the first 2 days following injection of 3H-thymidine were basal cells. Labeled dark cells appeared 6 hours after injection, reached their peak incidence at the fourth day postinjection, and then gradually decreased. Labeled intermediate cells were identified after the appearance of dark cells (12 hours) and reached a peak incidence at the fifth day after injection of 3H-thymidine. Lastly, labeled light cells were first observed on the fourth day postinjection and continued to increase until the tenth day, when they constituted 45% of the labeled cells. These data support the hypothesis that there is one cell line in the mouse vallate taste bud that undergoes morphological changes in its lifespan.

The “data-rich but information-poor” syndrome in water quality monitoring

Abstract: Water quality monitoring conducted routinely over time at fixed sites has been a part of most water quality management efforts for many years. It has been assumed that such monitoring plays a major role in management. However, the lack of routine data analysis, and reporting of information derived from such analysis, points up the fact that the exact nature of the role of routine, fixed-station monitoring is poorly defined. There is a need to very clearly define this role in the design of such systems if routine monitoring is to efficiently and effectively meet the information expectations placed on it. Design of routine monitoring systems will therefore have to consider not only the where, what, and when of sampling, but also why. A framework for including the “why” of monitoring in the design process is proposed and experience with using the framework in New Zealand is discussed.

Use of pseudo-concentrations to follow creeping viscous flows during transient analysis

Abstract: Creeping viscous flows are followed through finite element meshes by use of pseudo-concentrations which define material position. The concentrations, assumed to be transported only by convection, serve as material markers. Illustrations are presented related to industrial forming processes and the slow deformation of geological structures.

Evaluating the Performance of Paper People

Abstract: Several recent studies of performance appraisal have used the "paper people" approach, in which raters read performance vignettes and then rate the performance of several hypothetical ratees. This approach may lead to systematically different outcomes from studies in which ratings are based on the direct or indirect (e.g., via videotape) observation of ratees' behavior. One hundred and eleven studies published between 1975 and 1984 were grouped into five major substantive categories, and a comparative meta-analysis was used to contrast the outcomes of paper people studies to those of similar studies in which ratings were based on the observation of ratee behavior. Effect sizes were found to be significantly larger in paper people studies, although this difference was not uniform across all research areas. Results are discussed in terms of differences in signal-to-noise ratios across the two methods. Many methods have been used in research on performance appraisal. One dimension for classifying these methods is based on whether they use a "paper people" approach, in which subjects read a series of vignettes containing scaled behavior descriptions and then rate the performance of one or more hypothetical ratees, or an approach that is based on the direct or indirect observation (i.e., via film or videotape) of the behavior of one or more ratees. The latter method has been used in studies ranging from those examining annual perfomance appraisals conducted for administrative purposes in organizations (e.g., Cleveland & Landy, 1981) to laboratory studies, in which the ratees are actors carrying out performance scripts (e.g., Murphy, Balzer, Kellam, & Armstrong, 1984). The critical difference between the two approaches is that in a paper people study, subjects receive written descriptions of the performance they are to evaluate, whereas in studies involving behavior observation, subjects must observe, interpret, and recall the behavior of ratees in the process of evaluating their performance. The use of paper people in research on the interview has been strongly criticized (Gorman, Clover, & Doherty, 1978), although Dipboye, Stramler, and Fontenelle (1984) noted that this approach in fact simulates several features of the interview process. There are also grounds for criticizing the use of paper people in performance appraisal research. First, the question of whether raters observe or read summaries of the performance they are to evaluate has a substantial impact on the nature of the rating task. For example, raters' ability to accurately observe, encode, and recall performance is a critical concern in much of the recent research on performance appraisal (DeNisi, Meg

Microclimatic controls of nitrogen mineralization and nitrification in shortgrass steppe soils

Abstract: The depth distributions of rates of net nitrogen mineralization and nitrification were measured in a series of field and laboratory incubations. Field studies suggested that the highest rates of mineralization and nitrification occurred in the surface 2.5 cm such that forty to sixty percent of the N mineralization in 20-cm soil column occurred in the surface 2.5cm. Some upward nitrate movement occurred but laboratory studies suggested that surface rates were not an artifact of nitrate mobility alone. Microclimatic data indicate that either dew or upward movement and condensation of soil water vapor may drive biological activity at the soil surface. High rates of N mineralization even in dry horizons were sustained as long as water was stored within the 0-to 20-cm depth. High rates of nitrification were found in all incubations, and field measurements showed NO 3 − to be the predominant form of inorganic N, despite previous characterization of the shortgrass steppe as an NH 4 + -dominated system.

Mothers' internal state language to toddlers

Abstract: Two studies are presented which describe how mothers talk about internal states with language-learning toddlers during social interaction. In study I, mothers' internal state language was assessed longitudinally when toddlers were 13,20 and 28 months of age. In study 2, mothers' internal state language addressed to prelinguistic children with Down's syndrome was compared to that observed in mothers of non-handicapped children. The non-handicapped children were matched to the children with Down's syndrome in three groups for chronological age, mental age and level of language development. Results indicated that the quantity, complexity, content and attributional focus of mothers' internal state language was significantly affected by the following factors: children's developmental abilities, other child characteristics, differences in social context, and mothers' beliefs about their children's development. Implications of these results and future directions for research are discussed. The ability to share information about intentions, cognitions and feeling states plays a vital role in the regulation of human interaction. Knowing a partner's feelings or intentions

Scrotal circumference in yearling Hereford bulls: adjustment factors, heritabilities and genetic, environmental and phenotypic relationships with growth traits.

Abstract: Field data on 4,233 yearling Hereford bulls were analyzed using fixed and mixed model least-squares procedures to examine factors affecting scrotal circumference; determine appropriate adjustment factors; and study genetic, environmental and phenotypic relationships among scrotal circumference and growth traits. Scrotal circumference was affected by postweaning feed level; contemporary group/feed level; age of dam; and covariates age, weight and height. Of the three covariates, weight had the greatest effect, and any factor which caused an increase in weight tended to increase scrotal circumference. Quadratic effects of age, weight, height and age X age of dam interaction effects were significant or approached significance, but were of minor importance. Large contemporary group effects suggested the need for expressing scrotal circumferences as trait ratios or as deviations from contemporary group means. Scrotal circumference adjustment factors recommended for yearling Hereford bulls were .026 cm X d-1 of age and .8, .2 and .1 for sons of 2-, 3- and 4-yr old dams, respectively. Heritability of weight-adjusted scrotal circumference was .46 +/- .06 compared with .49 +/- .06 for age-adjusted scrotal circumference, indicating considerable additive genetic variation for relative scrotal size. Correlations between scrotal circumference and growth traits were moderate to high. The genetic correlation between scrotal circumference and yearling weight was the highest of these at .44 +/- .16. Potential implications of this relationship are discussed.

Germanium at high pressures.

Abstract: X-ray diffraction experiments have been carried out on germanium in a diamond anvil cell to 26 GPa. The pressure at the transition to the metallic phase (II) has been studied in different pressurizing media, giving 10.6\ifmmode\pm\else\textpm\fi{}0.05 GPa in a quasihydrostatic medium (4:1 methanol:ethanol mixture), 9.8\ifmmode\pm\else\textpm\fi{}0.1 GPa in NaCl, and 8.1\ifmmode\pm\else\textpm\fi{}0.3 GPA when the sample was compressed directly between the anvils. The compression curve for phase II has been fitted to a modified Murnaghan equation. Upon release of pressure the transformation from phase II to III (tetragonal) was found at 7.6\ifmmode\pm\else\textpm\fi{}0.05 GPa. It was found that the details of the transition depended on the stress condition and rate of decompression.