Showing papers by "University of Nevada, Reno published in 1987"

Conceptualizing How Job Involvement and Organizational Commitment Affect Turnover and Absenteeism

Abstract: This paper presents one conceptualization of how job involvement and organizational commitment could interact to affect turnover and absenteeism.

The treatment utility of assessment. A functional approach to evaluating assessment quality.

Abstract: \" In practical terms, the sine qua non of the modes, methods, devices, strategies, and theories of clinical assessment is their contribution to treatment outcome. The importance of this contribution has often been noted, but under many different labels and rationales. The resultant conceptual confusion has considerably restricted the visibility and frequency of research in this critical area. In this article we propose a name for the impact of assessment on treatment outcome: the \"treatment utility of assessment. \"' Some of the questions that can be asked about the treatment utility of assessment are described, and methods appropriate for asking them are examined. Finally, the implications of this kind of utility for other approaches to evaluating assessment quality are analyzed. Clinical assessment is an important and fertile area of psychology, and yet there is general agreement that it has not been in a state of continuous and healthy growth (e.g., Bersoff, 1973; Korchin & Schuldberg, 1981; Rorer & Widiger, 1983). Compared to the early days of clinical psychology, there has been a decline in the emphasis on clinical assessment both in training and in practice (Garfield & Kurtz, 1973, 1976; Levitt, 1973; Shemberg & Keeley, 1970). One reason may be that clinical assessment has not yet proven its value in fostering favorable treatment outcomes. As clinical psychologists have devoted more and more time to treatment activities, the practical value of assessment has come under closer scrutiny (McReynolds, 1985). Unfortunately, experienced clinicians have not always found assessment data to be useful in treatment (Adams, 1972; Daily, 1953; Meehl, 1960; Moore, Bobbitt, & Wildman, 1968). Even the proponents of clinical assessment admit that \"we do not believe that the current [high] status of testing is due to its demonstrated value\" (Kaplan, Colarelli, Gross, Leventhal, & Siegel, 1970, p. 15). The lack of empirical evidence for the practical value of assessment has long been noted. In 1959, Meehl pointed out that, even if an assessment procedure is reliable and valid, a clinician might \"be seriously in error if he concluded therefrom that his tests were paying o f f in practice. On this question there i s . . . no published empirical evidence\" (p. 117). Twenty-two years later, Korchin and Schuldberg (1981) were still worried that \"clinical assessment may not provide the kind of information needed by therapists. Objective evidence is slim\" (p. 1154). More recently, McReynolds (1985) asked \"Are tests helpful to the therapist? Amazingly, there has been little research on this crucial question\" (p. 10). The purpose of the present article is to consider how to make better progress in understanding the role of assessment in successful treatment. Any lack of evidence on the clinical value of assessment is not caused by a lack of appreciation for its ultimate practical purposes. Korchin (1976) defined clinical assessment as \"the process by which clinicians gain understanding of the patient necessary for making informed decisions\" (p. 124). Thus, the \"basic justification for assessment is that it provides information of value to the planning, execution and evaluation of treatment\" (Korchin & Schuldberg, 1981, p. 1154). Wiggins (1973) said, \"Although measurement and prediction may be evaluated by formal psychometric criteria, such as reliability and validity, the outcomes of [assessment] decisions must be evaluated in terms of their utilities for individuals and institutions within our society\" (p. 272, emphasis in original). Meehl (1959) phrased it as follows: \"In what way and to what extent does t h i s . . , information help us in treating the patient?\" (1959, p. 117). He called this question \"ultimately the practically significant one by which the contributions of our [assessment] techniques must be judged\" (p. 116). Definition of the Treatment Utility of Assessment The impact of clinical assessment on treatment outcome has been discussed under a wide variety of labels. Among other terms, it has been viewed as a matter of incremental validity (Mischel, 1968), concurrent validity (Meehl, 1959), construct validity (Edwards, 1970), predictive validity (Lord & Novick, 1968), discriminative efficiency (Wiggins, 1973), and utility (Cronbach & Gleser, 1965). There is considerable confusion about the concepts relevant to the measurement of pragmatic clinical value. We propose to use the phrase the treatment utility of assessment to refer to the degree to which assessment is shown to contribute to beneficial treatment outcome, l 1 Earlier (Nelson & Hayes, 1979), we had used the term treatment validity. Although utility issues can indeed be considered an aspect of validity, the present term seems more direct. November 1987 9 American Psychologist Copyright 1987 by the American Psychological Assooation, Inc. 0003-066X/87/$00.75 Vol. 42, No. I I, 963-974 963 An assessment device, distinction, or strategy has this kind of utility if it can be shown that treatment outcome is positively influenced by this device, distinction, or strategy. The treatment utility of assessment deserves to be termed a type of utility because it relates closely to the functional thrust of that psychometric term. The need to qualify the word utility with the adjective treatment is justified by two facts. First, utility has been almost exclusively evaluated in terms of personnel decisions (e.g., Wiggins, 1973). The issues and methods involved in demonstrating the impact of assessment on treatment outcomes differ significantly from the methods appropriate to the analysis of personnel decisions. Second, in personnel matters the concept of utility has come to refer primarily to the cost-benefit ratio of assessment strategies. This is why it was originally distinguished from predictive validity (Mischel, 1968). The treatment utility of assessment is not primarily a matter of cost-benefit analysis but of the demonstration of a particular type of benefit. Barriers to Research on the Treatment Utility of Assessment Theorists have long believed that research on the treatment utility of assessment should be feasible. \"It is well within the capacity of available research methods and clinical facilities to determine what, if any, is the pragmatic advantage of a personality assessment\" (Meehl, 1959, p. 125). Why then has there continued to be so little research? There are several possible reasons. First, because of conceptual confusion about the psychometric concepts relevant to the treatment utility of assessment, little has been written about the kinds of methods appropriate to treatment utility questions. In the present article, we present a taxonomy of treatment utility methods in the hope of alleviating this problem. Second, \"Clinical p s y c h o l o g i s t s . . , often make a sharp cleavage between their roles as diagnostician and therapist\" (Blatt, 1975, p. 336). Assessment is often not integrated into the therapy process. When the two are disconnected, the value of assessment seemingly turns on the question, Is this diagnosis correct? not Is this assessment useful in treatment? Some clinicians even fear that the assessment process is negatively intrusive on the therapeutic alliance. By focusing on the contribution of assessment to treatment outcome, treatment utility provides an approach for the testing of such concerns and may itself help integrate assessment and treatment roles. Another part of the problem may lie in the belief that complete psychometric purity is necessary before the treatment utility of assessment can be shown or even examined. Wiggins (1973), who has emphasized the The authors would like to thank Paul McReynolds for his helpful comments on an earlier draft of this article. Correspondence concerning this article should be addressed to Steven C. Hayes, Department of Psychology, University of Nevada-Reno, Reno, NV 89557-0062. practical importance of assessment more than most psychometric theorists, noted the possibility that \"concern with the technical problems of measurement . . . has resulted in a relative neglect of the broader context in which such problems arise, namely, the optimal assignment of men to jobs or treatments\" (p. 272). As we will show, there seems to be little reason to delay treatment utility research until psychometrically perfect devices are

Chemistry, biochemistry, and physiology of insect cuticular lipids

Abstract: The chemistry, biochemistry, and physiology of insect cuticular lipids are reviewed. The types of components present in cuticular extracts are described with special emphasis on the occurrence and identification of the di- and trimethylalkanes and the newly discovered tetramethylalkanes. The methods used in the extraction of cuticular components are discussed, including recommendations to standardize procedures. The structural elucidation of methylalkanes, particularly the mass spectral interpretation of multi-methyl-branched alkanes, is reviewed. The biosynthesis of cuticular lipids is discussed with emphasis on the hydrocarbon components, describing elongation reactions and the origin of the methyl branches. The effects of environment and development on cuticular lipids are reviewed.

Ethnicity and Practice

Abstract: A perusal of the contents of any social science journal will indicate that ethnicity has been a popular topic during the past two decades. Yet despite the volume of material produced, this period has not seen a notable increase in theoretical sophistication in the field (Drummond 1983:803; Young 1983). For the most part students of ethnicity remain mired in antique arguments about motivation that obscure as much as they illuminate. The following discussion attempts to break through some entrenched conceptual blinders by drawing on the theory of practice outlined by Pierre Bourdieu (1977). This theory avoids the explanatory gaps and fallacious reasoning and at the same time allows richer interpretations of ethnic phenomena, individual and collective, than do conventional models of ethnicity. Since individual and collective expressions of ethnicity have elicited divergent theoretical treatments, the practice theory of ethnicity promises to give new unity to a fragmented field of study.

Control of a Flexible Robot Arm: Experimental and Theoretical Results

Abstract: The operation of high precision robots is severely limited by. their manipulator dynamic deflection, which persists for a period of time after a move is completed. These unwanted vibrations deteriorate the end effector positional accuracy and reduce significantly the robot arm production rate. A “rigid and flexible motion controller” is derived to introduce additional damping into the flexible motion. This is done by using additional sensors to measure the compliant link vibrations and feed them back to the controller. The existing actuators at the robot joints are used (i.e., no additional actuators are introduced). The performance of the controller is tested on a dynamic model, developed in previous work, for a spherical coordinate robot arm whose last link only is considered to be flexible. The simulation results show a significant reduction in the vibratory motion. The important issue of control and observation spillover is examined and found to present no significant practical problems. Partial evaluation of this approach is performed experimentally by testing two controllers, a “rigid body controller” and a “rigid and flexible motion controller,” on a single joint of a spherical coordinate, laboratory robot arm. The experimental results show a significant reduction in the end effector dynamic deflection; thus partially validating the results of the digital simulation studies.

Biosynthesis and Endocrine Regulation of Sex Pheromone Production in Diptera

Abstract: Publisher Summary This chapter discusses the biosynthesis and endocrine regulation of sex pheromone production in Diptera. In Diptera, as in other insects, gamete fertilization is the end result of a complex series of behaviors that are released by taste, touch, sound, smell, and sight. Sex pheromones have been demonstrated in 43 species of Diptera, both male and female, and have been chemically identified in 17 species. These pheromones may be active at a distance, at close range, or only on contact. The female-produced sex attractant in Dacus oleae has an effective range of several meters. Other dipteran pheromones have an effective range of only several centimeters and release courtship behavior, as in Hippelates collusor, Lucilla cuprina, and Drosophila melanogaster, or increase mating strike activity as in Musca domestica, Haematobia irritans, and Cochliomyia hominovorax. Diptera vary considerably as to the sites of pheromone production. Pheromone is synthesized in the rectal glands of tephritids, in the intra-anal lobes in Drosophila grimshawi, and in epidermal tissue in the housefly and tsetse fly. The pheromone biosynthetic sites have not been identified for the remaining Diptera, although the oenocytes have been suggested as a synthetic site for pheromones in Culicoides nubeculosus.

Familial resemblance in the blood pressure response to sodium restriction

Abstract: Familial resemblance in the blood pressure response to sodium restriction in normotensive persons was investigated. Forty-four families of identical twin children participated in a sodium restriction (less than or equal to 75 meq/day) protocol for a period of 12 weeks. Subjects were residents of central Indiana, and the study was conducted over a three-year period. Parent-offspring and sibling-sibling resemblances for actual blood pressure were not different under conditions of ad lib sodium intake versus sodium restriction. Mother-offspring resemblance in blood pressure change with sodium restriction was significant for systolic (p less than 0.001), diastolic (p less than 0.05), and mean arterial (p less than 0.05) pressures. Sibling-sibling and twin-twin resemblances were also highly significant for the change in all three blood pressures. Father-offspring resemblances were marginal (p less than 0.10). This study is, to the author's knowledge, the first to demonstrate significant familial resemblances in blood pressure change with sodium restriction in normotensive persons.

Analytical models for the rigid body motions of skew bridges

Abstract: The rigid body motions of the bridge deck, along with the impact between the bridge deck and the abutments, were the source of extensive damage on skew highway bridges during the 1971 San Fernando earthquake. In this paper, a model for the rigid body motions of skew bridges is presented and analysed. The focus of the model is the appropriate representation of the impact between the bridge deck and the abutments and the explanation of the inducement of in-plane rotational vibrations of the bridge deck as the result of this impact. A simplified model is briefly described first, and the kinematic mechanism of the problem is explained. Then, the analysis of a more detailed and realistic model follows. This model is applied on a short skew bridge located in Riverside, California. The response of this bridge to several earthquake shakings revealed that the planar rigid body rotations of the deck are induced primarily as a result of the skewness of the deck and the impact between the deck and the abutments.

Robust Nonlinear Attitude Control of Flexible Spacecraft

Abstract: This paper presents an approach to large-angle rotationalmaneuvers of a spacecraft-beam-tip body configuration based onnonlinear invertibility and linear feedback stabilization. A controllaw Ud is derived for the decoupled control of attitude angles, lateralelastic deflections, slopes due to bending and angular deflection dueto torsion at the tip of the beam using torquers and force actuators.For the stabilization of the elastic modes, a linear feedback controllaw us is obtained based on a linearized model augmented with aservocompensator. Simulation results are presented to show thatlarge slewing and elastic mode stabilization can be accomplished.

Component and Process Analysis of Cognitive Therapy

Abstract: A component and process analysis of cognitive therapy was conducted. Three components, distancing, cognitive restructuring, and behavioral homework, were presented in various sequential combinations during 12 wk. of treatment to 12 women between 22 and 64 yr. of age (M = 41.5 yr.). Time-series analyses of individual improvement suggested that components combined in an additive rather than interactive manner. The mechanisms through which components initiated therapeutic change were evaluated by measures assessing both cognitive and behavioral processes specific to depression. The results of the component and process analysis differed from predictions derived from cognitive theory. Replication with a larger sample is needed. Implications for the practice of and further research in cognitive therapy are discussed.

Sex and age affect vulnerability of desert rodents to owl predation

Abstract: Pelvic morphology was examined to distinguish sexes of three prey species eaten by great horned owls, and age classes of one of these species. Comparisons of sex ratios in prey populations with frequencies of males and females in owl diets indicated that male Dipodomys ordii and female Peromyscus maniculatus were more vulnerable to owl predation than the opposite sexes of these species. Furthermore, juvenile Microtus montanus were more vulnerable than adults and, within the juveniles, females were more vulnerable than males. We examined morphological (body size) and behavioral (degree of activity) attributes of these prey species, and concluded that either morphology or behavior may facilitate differential vulnerability in Dipodomys , whereas behavioral differences between sex and age classes are more likely to account for differential vulnerability in Microtus . For Peromyscus there are no body size or activity differences between sexes that are consistent with differential vulnerability, but body weights of female Peromyscus are more variable than weights of males, which could promote female-biased vulnerability if predators select large prey.

Representation, testing and policy implications of planning processes

Abstract: Various ways to represent planning processes to test and draw policy implications from them are presented. We argue that three kinds of variables should be included: context, process and outcome. Four different models which incorporate these three variables are proposed, and data from a large public sector planning study are fitted to these four models. The findings suggest that the process-outcome link is the key to understanding the effectiveness of planning processes.

Activities of enzymes that detoxify superoxide anion and related toxic oxyradicals in Trichoplusia ni

Abstract: In third-, fourth-, and fifth-instar larvae of the cabbage looper moth, Trichoplusia ni, the activities of the antioxidant enzymes, superoxide dismutase (SOD*), catalase (CAT), glutathione peroxidase (GPOX), and glutathione reductase (GR) were examined using 850 g supernatants of whole-body homogenates. The enzyme activities, expressed as units mg−1 protein min−1 at 25°C ranged as follows: SOD, 0.67-2.13 units; CAT, 180.5-307.5 units; GPOX, none detectable; and GR, 0.40-1.19 units. There was a similar pattern of changes for SOD and CAT activities with larval ontogeny, but not for GR. The cabbage looper apparently uses SOD and CAT to form a “defensive team” effective against endogenously produced superoxide anion (O2⪸). Glutathione may serve as an antioxidant for the destruction of any organic/lipid peroxides formed, and GSH oxidized to glutathione disulfide would be recycled by GR. Bioassays against pro-oxidant compounds exogenous sources of (O2⪸) show high sensitivity of mid-fifth instars to the linear furanocoumarin, 8-methoxypsoralen (xanthotoxin) primarily from photoactivation (320-380 nm), and auto-oxidation of the flavonoid, quercetin. The LC50s are 0.0004 and 0.0045% (w/w) concentration of xanthotoxin and quercetin, respectively. Both pro-oxidants have multiple target sites for lethal action and, in this context, the role of antioxidant enzymes is discussed.

Influence of familiarity on frequency of inbreeding in wild horses

Abstract: Data on mechanisms of inbreeding avoidance or on the frequency ofincestuous mating in mammalian populations are uncommon (Cockburn et a!., 1985; Hoogland, 1982; Packer, 1979; Pusey, 1980), and, for ungulates, they are lacking. Almost 100 years ago Edward Westermarck implicated familiarity as a possible mechanism; children who were reared together avoided mating with one another as adults (Westermarck, 1891). Recent experimental evidence for both humans, primarily from Israeli Kibbutzim (Shepher, 1983), and nonhumans (Bateson, 1983; Blaustein and O'Hara, 1982; Holmes and Sherman, 1983) suggests that associations at early ages influence later social behavior including breeding. Despite a strong body oftheoretical expectations (Alexander, 1979; Bekoff, 1981; Moore and Ali, 1984), little empirical support for this idea exists from observations of wild mammals. Virtually nothing is known ofthe frequency that individuals who are reared together encounter or breed with one another as adults (but, see Hoogland, 1982). This problem generally arises because of the difficulty of acquiring information on the reproductive relationships among members offamily groups once juveniles attain breeding ages, and because, in natural populations, it is rarely known which individuals are true fathers. Here we present data, made available by natural field experiments, that bear on this issue. We show that, for wild horses (Equus cabal/us) of the Great Basin Desert of North America, incestuous (father-daughter) matings sometimes occur, and that they result because individuals fail to remember others with whom they previously associated.

Implications of the Wounded-Healer Paradigm for the Use of the Self in Therapy

Abstract: The use of the self in therapy relates closely to the paradigm of the wounded-healer. The paradigm holds that deep within each healer lies an inner wound which may not only play an important role in vocational choice. but constitute a significant if not essential factor contributing to healing the patient. Its mythical origins are described along with a diagrammatic model which attempts to analyze the interactional dynamics in the healerpatient encounter.

Particle Ingestion by Tilapia galilaea is Not Affected by Removal of Gill Rakers and Microbranchiospines

Abstract: Particle ingestion by filter-feeding Galilee Saint Peter's fish Tilapia galilaea increased as a function of particle size, leveling off when particle diameter exceeded 20 μm. Ingestion rates by this cichlid also increased with particle concentration, asymptotically approaching maxima of 4,785 and 84,746 particles˙fish −1˙min−1 for small (3.9–6.0 cm standard length, SL) and large (12.6–14.3 cm SL) fish, respectively. Surgical removal of gill rakers and microbranchiospines did not affect particle ingestion rates or selectivity.

Modeling of sulfide capacities of silicate melts

Abstract: An examination of the solution chemistry of sulfides in silicates leads to a method for the calculation of the sulfide capacities of silicate melts using the Flory model for polymeric silica chains. Calculations for the CaO−SiO2, FeO−SiO2, and MgO−SiO2 binary systems at 1773 K and 1923 K are shown to be in good agreement with available experimental data and to be more reliable than calculations based on the empirical concept of basicity.

Nonlinear Adaptive Attitude Control of Spacecraft

Abstract: A model reference adaptive control law is presented for largeangle rotational maneuvers of spacecraft using reaction jets. It isassumed that the various parameters of the spacecraft arecompletely unknown, and unknown but bounded disturbancetorques are acting on the spacecraft. The controller includes adynamic system in the feedback path. Simulation results arepresented to show that fast, large angle rotational maneuvers can beperformed using the adaptive controller in spite of uncertainty inthe system.

Evidence for a sex pheromone metabolizing cytochrome P‐450 mono‐oxygenase in the housefly

Abstract: Direct evidence is presented for the role of a cytochrome P-450 monooxygenase (called mixed-function oxidase, or polysubstrate mono-oxygenase, PSMO) in the metabolism of the sex pheromone (Z)-9-tricosene to its corresponding epoxide and ketone in the housefly. A secondary alcohol, most likely an intermediate in the conversion of the alkene to the ketone, was also tentatively identified. The results of in vivo and in vitro experiments showed that the PSMO inhibitors, piperonyl butoxide (PB) and carbon monoxide, markedly inhibited the formation of epoxide and ketone from (9,10-3H) (Z)-9-tricosene. An examination of the relative rates of (Z)-9-tricosene metabolism showed that males exhibited a higher rate of metabolism than females with the antennae of males showing the highest activity of any tissue/organ examined. The major product from all tissues/organs was the epoxide. Data from experiments with subcellular fractions showed that the microsomal fraction had the majority of enzyme activity, which was strongly inhibited by PB and CO and required NADPH and O2 for activity. A carbon monoxide difference spectrum with reduced cytochrome showed maximal absorbance at 450 nm and allowed quantification of the cytochrome P-450 in the microsomal fraction of 0.410-nmol cytochrome P-450 mg−1 protein. Interaction of (Z)-9-tricosene with the cytochrome P-450 resulted in a type I spectrum, indicating that the pheromone binds to a hydrophobic site adjacent to the heme moiety of the oxidized cytochrome P-450.

Continuation of Antler and Sonoma orogenic belts to the eastern Sierra Nevada, California, and Late Triassic thrusting in a compressional arc

Abstract: Strong stratigraphic and structural similarities exist between metamorphic rocks of the Saddlebag Lake pendant, eastern Sierra Nevada, California, and rocks of the Antler and Sonoma orogenic belts in west-central Nevada These similarities indicate that the Roberts Mountains and Golconda allochthons can be traced to the eastern edge of the Sierra Nevada batholith in California Newly recognized thrust faults that imbricate the Antler and Sonoma rocks and younger metamorphic rocks are of Late Triassic age and are cut by a 219 Ma pluton These thrusts apparently were active during a major episode of Late Triassic arc volcanism, and they constrain the age of the Golconda thrust as pre–latest Triassic The continuation of the Antler and Sonoma orogenic belts to the Saddlebag Lake pendant means that large strike-slip displacements cannot have occurred on northwest-trending faults along the eastern edge of the Sierra Nevada However, a large structural break may terminate the Antler and Sonoma belts at or near the western edge of the Saddlebag Lake pendant

Sexual transfer of prostaglandin precursor in the field cricket, Teleogryllus commodus

Abstract: . When injected into the haemolymph of newly emerged adult males of the field cricket, Teleogryllus commodus (Walker), [3H]arachidonic acid is incorporated into tissue phospholipids. Two reproductive tissues, testes and accessory glands, incorporate and preserve the labelled arachidonic acid for at least 49 days. With onset of circadian rhythm-controlled spermatophore production, radioactive arachidonic acid is incorporated into spermatophore phospholipids. After mating with untreated females, radioactivity was detected in spermathecae and in haemolymph from females. Some of the transferred radioactive arachidonic acid is subsequently converted into prostaglandins. Hence, males of T. commodus transfer prostaglandin synthetase activity and substrate by way of spermatophores during mating

Control of the soil water balance by sagebrush and three perennial grasses in a cold‐desert environment

Abstract: This study compared the capacity of monocultural stands of crested wheatgrass, giant wildrye, streambank wheatgrass, and Wyoming big sagebrush to deplete water from a clay‐loam soil. Soil water balance of a natural sagebrush steppe was used as a reference point. Transplanted crested wheatgrass plants extracted 243 mm of water from the soil during the first growing season, using most of the plant‐available water. The other species extracted less water, but evapotranspiration from all stands was well over the average annual precipitation for the study area (224 mm). In the second year, all four species extracted water from the entire 2.2‐m profile and used most of the available water. The native community removed essentially all of the available soil moisture in each of the three years. Despite phenological and morphological differences among species, patterns of water depletion were generally similar. Seasonal evapotranspiration varied little among species but was correlated with the soil water av...