Showing papers by "California State University, Long Beach published in 1997"

Structural control: past, present, and future

Abstract: This tutorial/survey paper: (1) provides a concise point of departure for researchers and practitioners alike wishing to assess the current state of the art in the control and monitoring of civil engineering structures; and (2) provides a link between structural control and other fields of control theory, pointing out both differences and similarities, and points out where future research and application efforts are likely to prove fruitful. The paper consists of the following sections: section 1 is an introduction; section 2 deals with passive energy dissipation; section 3 deals with active control; section 4 deals with hybrid and semiactive control systems; section 5 discusses sensors for structural control; section 6 deals with smart material systems; section 7 deals with health monitoring and damage detection; and section 8 deals with research needs. An extensive list of references is provided in the references section.

Non-operative treatment of subacromial impingement syndrome

Abstract: We performed a retrospective study of 616 patients (636 shoulders) who had subacromial impingement syndrome to assess the results of non-operative treatment. The diagnosis was made on the basis of a positive impingement sign and the absence of other abnormalities of the shoulder, such as full-thickness tears of the rotator cuff, osteoarthrosis of the acromioclavicular joint, instability of the glenohumeral joint, or adhesive capsulitis. All patients were managed with anti-inflammatory medication and a specific, supervised physical-therapy regimen consisting of isotonic exercises for strengthening of the rotator cuff. The average duration of follow-up was twenty-seven months (range, six to eighty-one months). Over-all, 413 patients (67 per cent) had a satisfactory result. One hundred and seventy-two patients (28 per cent) had no improvement and went on to have an arthroscopic subacromial decompression. Thirty-one patients (5 per cent) had an unsatisfactory result but declined additional treatment. Seventy-four (18 per cent) of the 413 patients who had a successful result had a recurrence of the symptoms during the follow-up period; the symptoms resolved with rest or after resumption of the exercise program. The patients were stratified according to age, the duration of symptoms, and acromial morphology. Patients who were twenty years old or less and those who were forty-one to sixty years old fared better than those who were twenty-one to forty years old. Patients who were more than sixty years old had the poorest results. Sixty-seven (78 per cent) of the eighty-six patients in whom the symptoms had been present for less than four weeks had a satisfactory result, compared with 144 (63 per cent) of the 228 who had had the symptoms for one to six months and with 202 (67 per cent) of the 302 who had had the symptoms for more than six months. Thirty-two (91 per cent) of the thirty-five patients who had a type-I acromion had a successful result, compared with 173 (68 per cent) of the 256 who had a type-II acromion and with 208 (64 per cent) of the 325 who had a type-III acromion. Shoulder dominance, gender, and concomitant tenderness of the acromioclavicular joint did not affect the result significantly (p = 0.084, 0.555, and 0.365, respectively).

Epidural Analgesia Compared with Combined Spinal–Epidural Analgesia during Labor in Nulliparous Women

Abstract: Background Among nulliparous women, there appears to be an association between the use of epidural analgesia during labor and an increased risk of dystocia. We tested the hypothesis that combined spinal–epidural analgesia, which permits ambulation during labor, is associated with a lower incidence of dystocia than continuous lumbar epidural analgesia. Methods Between July 1995 and September 1996, we randomly assigned 761 nulliparous women in spontaneous labor at term who requested epidural analgesia to receive either continuous lumbar epidural analgesia or a combination of spinal and epidural analgesia. Among the women who received combined spinal–epidural analgesia, some were discouraged from walking and others were encouraged to walk. Maternal and neonatal outcomes, the incidence of dystocia necessitating cesarean section, and measures of patients' satisfaction were compared in the two groups. Results There were no significant differences in the overall rate of cesarean section, the incidence of dystoci...

Diagnostic principles in pleural disease

Abstract: When a patient with an undiagnosed pleural effusion is evaluated, the first question to answer is whether the patient has a transudate or an exudate. This is best done using Light's criteria, but these criteria occasionally misidentify a transudate as an exudate. If the patient's pleural fluid meets exudative criteria, but the patient appears clinically to have a transudative effusion, then the serum-pleural fluid albumin gradient should be measured. If this is greater than 1.2 g-dL-1, the patient probably does have a transudative effusion. If the patient has an exudative pleural effusion, additional tests are indicated to determine the aetiology of the effusion. The gross appearance and the odour of the pleural fluid should be noted and samples of all exudates should be sent for bacterial cultures. Laboratory tests that are useful in the differential diagnosis of exudative pleural effusions include: differential white cell count of the pleural fluid; cytology of the pleural fluid; and levels of adenosine deaminase, glucose, amylase and lactate dehydrogenase in the pleural fluid. If pleural tuberculosis is suspected, a needle biopsy of the pleura is indicated. Thoracoscopy is very efficient at diagnosing malignant pleural effusion and tuberculosis pleuritis, but rarely establishes any other diagnosis.

A path model of perceived organizational support

Abstract: According to the social exchange model of perceived organizational support (Eisenherger, Htmtingtrm, Hutchison. & Sowa. I9fi6) employees exchange their loyalty and effort for material and .social rewards from the organization. Employees' perceptions of support from the organization serve as the link between actions taken hy the organization and actions taken by the employee. Surveys measuring employees' perceptions of the organization's actions (i.e., role ambiguity, role conflict, decision centralization. supervi,wr consideration, and participation in decision making) were administered to a sample of 205 members of the faculty and staff of a large western state universit\. Path analysis provided results that were consistent with the social exchange model. Employees' perceptions of the organization's actions had direct effects on their perceptions of support from their supervisors, management and the organization, but did not have direct effects on their commitment to the organization. Consistent with the social exchange model, only employees' perceptions of support from the organization had direct ^effects on their commitment to the organization. Eisenberger, Huntington, Hutchison, and Sowa (1986) proposed that employees' commitment to their organization is based, in part, on their perception of the organization's commitment to them. This built on Blau's (1964) description of social exchange as an opwn-ended stream of transactions that result in diffuse and unspecified obligations on the part of both parties involved in social interaction. The organization's commitment to its employees was conceptualized as the employees' perceptions of support from the organization (i.e., perceived organizational support). Several studies have reported that employees with high levels of perceived organizational support are absent less often and are more conscientious about carrying out their work responsibilities than are employees with low levels of perceived organizational support (Eisenberger etal., 1986; Eisenberger, Fasolo,&Davis-LaMastro, 1990). Author's Note: t would like lo thank Martin Chemers, H. Kandy Rohde. and Rick Crandall for helpful comments on earlier drafts of this article.

The Colors of Anger, Envy, Fear, and Jealousy A Cross-Cultural Study

Abstract: Word associations or verbal synesthesia between concepts of color and emotions were studied in Gersnany, Mexico, Poland, Russia, and the United States. With emotion words as the between-subjects variable, 661 undergraduates indicated on 6-point scales to what extent anger, envy, fear, and jealousy reminded them of 12 terms of color. In all nations, the colors of anger were black and red, fear was black, and jealousy was red. Cross-cultural differences were (a) Poles connected anger, envy, and jealousy also with purple; (b) Germans associated envy and jealousy with yellow; and (c) Americans associated envy with black, green, and red, but for the Russians it was black, purple, and yellow. The findings suggest that cross-modal associations originate in universal human experiences and in culture-specific variables, such as language, mythology, and literature.

Auctions and Bidding on the Internet: an Assessment

Abstract: Electronic commerce (EC) activities are growing rapidly on the internet. One area that receives little publicity is that of auctions and bidding. However, these interrelated activities can become a major EC factor due to the creation of special online brokering services as well as electronic auctions and bids offered directly by private and public organizations. This paper provides a discussion of the benefits and a description of the goods and services traded.

Gender-related stereotypes of transformational and transactional leadership

Abstract: This study investigated gender differences in transformational and transactional leadership, and gender-related stereotypes for these forms of leadership. Results indicated that there were no differences in the way the primarily Caucasian subordinates evaluated their actual male and female managers. There were, however, differences in ratings of stereotypic male versus stereotypic female leaders on transformational and transactional leadership, but only by female respondents. Finally, congruence between ratings of actual managers and ratings of stereotypic managers was found primarily for male respondents. Results suggest that stereotypes may be one explanation for gender differences found in prior research on transformational and transactional leadership.

An acoustic tracking of a megamouth shark, Megachasma pelagios: a crepuscular vertical migrator

Abstract: A 4.9 m TL megamouth shark, only the sixth specimen known to science, was tracked continuously for 50.5 h, during which it exhibited distinct vertical migrations at the dawn and dusk transitions. The male shark was captured on 21 October 1990 in a drift gill net off Dana Point, California, restrained overnight in a harbor, and released at sea the next afternoon. Horizontally, the shark moved slowly southward, covering 62 km on a relatively straight path with no significant diel changes. For the major part of the tracking, its rate of movement was 1.15 km h−1, as determined from positions at 15 min intervals. Considering a probable head current of 10–25 cm sec−1, its estimated through-the-water swimming speed was more likely 1.5–2.1 km h−1 (X¯ = 1.8, representing 0.1 body lengths sec−1). Vertically, the shark stayed shallow at night (12–25 m depth range, X¯ = 17) and deep during the days (120–166 m, X¯ = 149) but still well above the bottom at 700–850 m. The four twilight depth-change events were very distinct and always spanned the times of sunset or sunrise. The ascent and descent profiles are a reasonble match to isolumes on the order of 0.4 lux for an extinction coefficient (0.07) calculated from water transparency measurements. Furthermore, the steepest parts of the shark's profiles correspond closely to the times of maximum rate-of-change of illumination. These findings suggest that, except during nights, the shark's chosen depth was to a large degree determined by light level.

Graduate student/faculty mentoring relationships: Who gets mentored, how it happens, and to what end

Abstract: Given the importance of mentoring in the academic context, this study proposed five objectives. Analyses of surveys from 145 students across 12 universities and diverse disciplines, revealed first of all, a demographic profile of the typical graduate student protege and faculty mentor. Second, ten diverse communication strategies emerged that demonstrate how students initiate a mentoring relationship. Third, protege evaluations of their initiation attempts revealed their efforts to be somewhat ineffective and unduly difficult. Fourth, students reported their mentors to provide primarily psychosocial, rather than career support. And fifth, proteges characterized their mentoring relationships as extremely positive and satisfying. Results throughout are, for the most part, independent of both protege and mentor demographics (including ethnicity).

Attitudes toward Chinese-Accented Speech: An Investigation in Two Contexts

Abstract: This matched-guise study provides data on attitudes toward Mandarin Chinese-accented English by eliciting both Angloand Asian Americans'reactions to a male speaker. Study 1 discovered that in the c...

Intestinal epithelial barrier dysfunction in Crohn's disease

Abstract: Despite extensive research, the etiology of Crohn's disease remains unknown. Accumulating evidence suggests the possibility that a primary defect of intestinal barrier function may be present in Crohn's disease. In this review, the possible role of intestinal barrier defect in Crohn's disease is discussed. It has been recognized for some time that Crohn's patients have a defective intestinal epithelial barrier function manifested by an increase in intestinal permeability. Recent studies indicate that a subgroup of healthy first-degree relatives of Crohn's patients (a population at high risk for developing Crohn's disease) also have increased intestinal permeability. Additionally, this subgroup of patients have evidence of increased exposure to foreign antigens, suggesting a possible link between increase in intestinal permeability and increase in antigenic penetration. Furthermore, exacerbation of Crohn's disease is produced by agents that disrupt intestinal epithelial barrier function, while remission of active disease is induced by decreasing intestinal antigenic load. A "leaky gut" hypothesis is advanced which proposes that a preexisting disorder of intestinal permeability is responsible for the intestinal inflammation of Crohn's disease.

Prediction of High-Lift Flows Using Turbulent Closure Models

Abstract: The flow over two different multi-element airfoil configurations is computed using linear eddy viscosity turbulence models and a nonlinear explicit algebraic stress model. A subset of recently-measured transition locations using hot film on a McDonnell Douglas configuration is presented, and the effect of transition location on the computed solutions is explored. Deficiencies in wake profile computations are found to be attributable in large part to poor boundary layer prediction on the generating element, and not necessarily inadequate turbulence modeling in the wake. Using measured transition locations for the main element improves the prediction of its boundary layer thickness, skin friction, and wake profile shape. However, using measured transition locations on the slat still yields poor slat wake predictions. The computation of the slat flow field represents a key roadblock to successful predictions of multi-element flows. In general, the nonlinear explicit algebraic stress turbulence model gives very similar results to the linear eddy viscosity models.

New perspectives on graptolite distributions and their use as indicators of platform margin dynamics

Abstract: Graptolite distributions in Ordovician shelf, slope, and basinal facies in the Great Basin indicate that graptolites were scarce in open oceanic waters oceanward of the Cordilleran shelf margin and that they thrived in waters above the margin. This pattern is consistent with that of most zooplankton in modern oceans. It follows from these observations that the depositional setting of typical graptolitic shale was the area of the sea floor under continental-margin upwelling zones where graptolites flourished and within the oxygen-minimum zone where their rhabdosomes were preserved. With changes over time in relative sea level, deep oceanic circulation, and wind-driven surface circulation, the upwelling and oxygen-minimum zones may have thickened or thinned, migrated landward or oceanward, and expanded laterally, contracted, or even disappeared. The observed graptolite occurrences suggest that the primary graptolite biotope—that is, the habitat of diverse and abundant faunas—was a relatively narrow belt of upwelling waters along, and extending somewhat open oceanward from, the continental margin. Provinces were maintained only to the extent that species could disperse along continental margins. Distribution of typical graptolitic strata may be used to interpret development of continental margins, because such distribution incorporates a signal of sea-level rise or fall, oceanographic changes (especially upwelling), and tectonic events that led to creation and deterioration of upwelling conditions in which graptolites flourished.

Perceived Organizational Support : Further evidence of construct validity

Abstract: Wayne Shore and Lois Tetrick demonstrated in 1991 that the Survey of Perceived Organizational Support (SPOS), a measure of perceived employer commitment, was unidimensional and distinguishable from measures of affective and continuance commitment. In the present study, confirmatory factor analysis was used to further examine the construct validity of the scores on the SPOS. Participants were 205 members of the staff and faculty of a large western state university. Consistent with Shore and Tetrick's findings, the SPOS was found to be unidimensional. In addition, the SPOS was found to be distinguishable from two similarly conceptualized correlates of affective commitment: perceived supervisory support and organizational dependability. Findings are discussed with respect to their implications for understanding the commitment process.

Social Support and Depression among Older Adults Living Alone: The Importance of Friends Within and Outside of a Retirement Community

Abstract: Using socioemotional selectivity theory as a framework, the study described in this article examined the extent to which social support from friends both within and outside of a retirement community was associated with depression. Although levels of social support from friends within the retirement community were quantitatively high, they failed to have a significant effect on depression. In contrast, social support from friends living elsewhere consistently predicted low levels of depression. Practice implications include the importance of maintaining friendship ties with people living elsewhere and of strengthening friendship ties within the retirement community.

Upper Airway Anesthesia Reduces Phasic Genioglossus Activity During Sleep Apnea

Abstract: We hypothesize that stimulation of upper-airway mechanoreceptors during obstructive apnea augments upper airway muscle activity. If so, upper-airway anesthesia (UAA) should reduce mechanoreceptor output and therefore upper-airway muscle activity. To test this hypothesis, we studied the effect of UAA on the relationship between the phasic activity of the moving-time average (MTA) of the genioglossus electromyogram (EMG-GG) and the esophageal pressure deflection (DP) during obstructive apneas in non-rapid-eye-movement (NREM) sleep in a group of six men with severe sleep apnea. Before UAA, the phasic EMG-GG was linearly related to the deflections in esophageal pressure (DP) during the last three occluded breaths (both progressively increased). After UAA, the mean ratio of EMG-GG to DP decreased to 23% of the control value, from 0.17 +/- 0.04 to 0.04 +/- 0.01 (mean +/- SEM) arbitrary units/cm H2O (p < 0.05). The mean slope of the EMG-GG-versus-DP regression lines also decreased to 23% of the control value, from 0.22 +/- 0.03 to 0.05 +/- 0.01 arbitrary units/ cm H2O (p < 0.01). These findings suggest that stimulation of upper-airway mechanoreceptors during obstructive apnea in NREM sleep augments phasic genioglossus activity.

Restoration-based compensation measures in natural resource liability statutes

Abstract: I. INTRODUCTION In the United States, the atmosphere, oceans, estuaries, rivers, and plant and animal species are public trust resources. For the most part, the United States has not created private ownership rights to these resources but instead has established a system of public management to promote beneficial uses of the resources at no (or limited) charge to the public. In the past two decades, public policies have emphasized protecting the resources from injury and depletion. In particular, several major environmental statutes enacted in the 1970s designate resource management agencies as trustees of the natural resources on behalf of the public and enable the trustees to recover damages for injuries to public resources from releases of hazardous substances and discharges of oil. The primary federal statutes containing provisions establishing liability for injuries to natural resources in the public trust are the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA, more commonly known as Superfund) and the Oil Pollution Act (OPA). When OPA was promulgated in 1990, its natural resource liability provisions for oil spills superseded those previously established in the Clean Water Act in 1978. Other federal statutes containing natural resource trustee provisions include the National Marine Sanctuaries Act (formerly the Marine Protection, Research, and Sanctuaries Act), the Federal Water Pollution Control Act (or Clean Water Act), Deepwater Port Act of 1974, Outer Continental Shelf Lands Act Amendment of 1978, and Trans-Alaska Pipeline Authorization Act. These statutes broadly define natural resources to include land, fish, wildlife, biota, air, water, ground water, drinking water supplies, and other such resources belonging to, managed by, held in trust by, appertaining to, or otherwise controlled by the United States, any state or Indian tribe, or any foreign Government. The U.S. Department of the Interior promulgated regulations in 1986 and 1987 for natural resource damage assessments (NRDA) under CERCLA and subsequently revised the regulations in 1994 to respond to issues remanded to the agency by Ohio v U.S. Department of the Interior in 1994, as codified at 43 CFR [section]11. The National Oceanic and Atmospheric Administration (NOAA) promulgated NRDA regulations for OPA on January 5, 1996, as codified at 15 CFR [section]990. The standard measure of damages is the cost of restoring the resources to baseline conditions ("primary restoration") plus the interim loss in value from the time of the incident until full recovery. However, trustees are allowed to spend their recoveries only on enhancing or creating ("restoring, rehabilitating, replacing or acquiring the equivalent of") natural resources. The statutory restriction on the use of the recoveries has motivated the development of an alternative utility-theoretic measure of damages for interim losses - the cost of "compensatory restoration" actions providing inkind compensation. In the aftermath of the 1991 Exxon Valdez settlement, the use of contingent valuation became very controversial during the OPA rulemaking process (as it continues to be in the ongoing CERCLA reauthorization process). During the rule-making, industry and environmental interest groups as well as academic economists submitted extensive public comments on valuation issues in general and contingent valuation in particular. In the context of the wide-ranging public debate, NOAA reframed the concept of damages for interim losses in terms of providing compensatory restoration projects. Congress is currently considering bills to reauthorize CERCLA that would incorporate these concepts in statutory language. Reframing the damage claim brings several advantages. The revised format forces trustees to focus on the ultimate statutory goal - restoring resources - from the beginning of the assessment process, which may result in expediting restoration. …

An Evaluation of a Self-Management Program for Adults with Asthma

Abstract: The purpose of this study was to evaluate the impact of a self-management program for adults with moderate to severe asthma on compliance with inhaled, prescribed, nonemergency medications; asthma symptoms; and airway obstruction. In this controlled experimental study, 55 subjects from a rural community were randomized to one of two groups. Self-efficacy theory served as the framework for this study. Primary measures included the Metered Dose Inhaler (MDI) Chronolog, a journal of daily asthma concerns, and a peak-flow meter to appraise airway obstruction. Secondary measures included the Asthma Self-Management Assessment Tool (ASMAT) and the Self-Efficacy for Asthma Management Scale (SEAMS). These measures were completed pre- and post-intervention. Data analysis using descriptive and inferential statistics revealed that subjects receiving the self-management program increased compliance with inhaled medications (U = 271, p = .043).

Life history theory and human reproductive behavior : Environmental/contextual influences and heritable variation.

Abstract: The purpose of this article is to develop a model of life history theory that incorporates environmental influences, contextual influences, and heritable variation. I argue that physically or psychologically stressful environments delay maturation and the onset of reproductive competence. The social context is also important, and here I concentrate on the opportunity for upward social mobility as a contextual influence that results in delaying reproduction and lowering fertility in the interest of increasing investment in children. I also review evidence that variation in life history strategies is influenced by genetic variation as well. Finally, I show that cultural shifts in the social control of sexual behavior have had differential effects on individuals predisposed to high- versus low-investment reproductive strategies.