Showing papers by "Wayne State University published in 1990"

Reaction Path Following in Mass-Weighted Internal Coordinates

Abstract: Our previous algorithm for following reaction paths downhill (J. Chem. Phys. 1989, 90, 2154), has been extended to use mass-weighted internal coordinates. Points on the reaction path are round by constrained optimizations involving the internal degrees or freedom or the molecule. The points are optimized so that the segment or the reaction path between any two adjacent points is described by an arc or a circle in mass-weighted internal coordinates, and so that the gradients (in mass-weighted internals) at the end points or the arc are tangent to the path. The algorithm has the correct tangent vector and curvature vectors in the limit or small step size but requires only the transition vector and the energy gradients; the resulting path is continuous, differentiable, and piecewise quadratic

Entrepreneur Human Capital Inputs and Small Business Longevity

Abstract: Investigates small business longevity and financial capital structure using owner human capital measures and demographic traits as explanatory variables, including education level achieved, family background, and age of owner at business start. Data were obtained from a nationwide random sample of 4,429 non-minority males who started businesses between 1976 and 1982, drawn from the U.S. 1982 Characteristics of Business Owners (CBO) survey. Those firms still in operation in 1986 were identified. Results demonstrate that educational level is the most significant human capital variable for identifying business continuance. Also, age of owner was correlated to a lessening of owner effort--therefore, the older the owner is at startup (55 and older) the less likely a firm is to remain in operation. In addition, owners that purchased existing firms are more likely to remain in business than those that started a new venture. Further, owner educational background is a major indicator of the financial capital structure of new firms. Nearly all of the businesses analyzed received no equity capital from organized financial markets, but did have access to debt capital, and those with higher educational level received larger bank loans. Dependence on debt capital, from commercial banks or family and friends, for startup financing is not an accurate gauge of high failure risk. The importance of human versus financial capital as a factor in firm continuance remains unclear. (SFL)

Interdisciplinarity: History, Theory, and Practice

Abstract: In this volume, Julie Klein provides the first comprehensive study of the modern concept of interdisciplinarity, supplementing her discussion with the most complete bibliography yet compiled on the subject. Spanning the social sciences, natural sciences, humanities, and professions, her study is a synthesis of existing scholarship on interdisciplinary research, education and health care. Klein argues that any interdisciplinary activity embodies a complex network of historical, social, psychological, political, economic, philosophical, and intellectual factors. Whether the context is a short-ranged instrumentality or a long-range reconceptualization of the way we know and learn, the concept of interdisciplinarity is an important means of solving problems and answering questions that cannot be satisfactorily addressed using singular methods or approaches.

Automated software test data generation

Abstract: An alternative approach to test-data generation based on actual execution of the program under test, function-minimization methods and dynamic data-flow analysis is presented. Test data are developed for the program using actual values of input variables. When the program is executed, the program execution flow is monitored. If during program execution an undesirable execution flow is observed then function-minimization search algorithms are used to automatically locate the values of input variables for which the selected path is traversed. In addition, dynamic data-flow analysis is used to determine those input variables responsible for the undesirable program behavior, significantly increasing the speed of the search process. The approach to generating test data is then extended to programs with dynamic data structures and a search method based on dynamic data-flow analysis and backtracking is presented. In the approach described, values of array indexes and pointers are known at each step of program execution; this information is used to overcome difficulties of array and pointer handling. >

Forms of Interorganizational Governance for Multinational Alliances

Abstract: This study drew upon complementary work in transaction cost economics, organization theory, and international corporate strategy studies to examine governance forms for multinational alliances. An ...

The language teaching matrix

Abstract: Richards explains how effective language teaching involves a network of interactions between curriculum, methodology, teachers, learners, instructional materials. Each chapter discusses and examines the theoretical and practical dimensions of a central issue in language teaching. Topics covered include the nature of effective teaching, self-monitoring in teacher development, language and content, and teaching listening, speaking, reading and writing. Richards presents key issues in an accessible and highly readable style, and shows how teachers and teachers-in-training can be involved in the investigation of classroom teaching and learning. The emphasis is not on prescriptions but rather on developing effective teaching through understanding the various factors that interact in second language learning and in the second language classroom.

Emerging role of lactobacilli in the control and maintenance of the vaginal bacterial microflora.

Abstract: The vaginal microflora of healthy asymptomatic women consists of a wide variety (two to five isolates at any one time) of anaerobic and aerobic bacterial genera and species dominated by the facultative, microaerophilic, anaerobic genus Lactobacillus. That the vaginal flora forms part of a dynamically changing ecosystem is evident from the variable prevalence and population levels of each bacterial species detected with repetitive longitudinal sampling, with pregnancy, and with stage in the menstrual cycle. This review emphasizes the role that vaginal lactobacilli may play in control of the vaginal microflora and maintenance of the normal state. Lactobacilli possess many antagonistic properties and produce many metabolites that may be important in maintaining dominance in the vagina. Contradictory data from previous studies regarding the impact of factors such as contraception, catamenial products, and physiologic elements on the vaginal microflora are due in part to poor study design and differences in methodology. Well-designed and controlled investigations with large numbers of individuals in each group are needed, and the limitations of the methodology for such investigations must be considered. Studies of the normal flora, exploring the interaction of lactobacilli and other bacterial species, must be performed before the pathologic processes resulting in vaginitis or systemic sequelae are investigated. The healthy human body harbors an extensive number of microorganisms that inhabit surfaces and cavi

On the meaning of Maslach's three dimensions of burnout

Abstract: The dimensionality of Maslach's (1982) 3 aspects of job burnout--emotional exhaustion, depersonalization, and personal accomplishment--was examined among a sample of supervisors and managers in the human services. A series of confirmatory factor analyses supported the 3-factor model, with the first 2 aspects highly correlated. The 3 aspects were found to be differentially related to other variables reflecting aspects of strain, stress coping, and self-efficacy in predictable and meaningful ways. Implications for better understanding the burnout process are discussed.

Cognitive processes in perceived social support.

Abstract: Les auteurs rapportent deux etudes dans lesquelles ils essaient de montrer que le soutien social percu fonctionne en partie comme un construit cognitif de personnalite

Thermal diffusivity of isotopically enriched 12C diamond

Abstract: Type-IIA diamond single crystals containing approximately 0.1%, 0.5%, and 1% $^{13}\mathrm{C}$ were synthesized and their thermal diffusivities were measured at room temperature by the thermal-wave-mirage technique. The measured value (18.5 ${\mathrm{cm}}^{2}$/s) of the 0.1% $^{13}\mathrm{C}$ crystal was 50% higher than the 1% $^{13}\mathrm{C}$ (natural isotope abundance). This is the highest room-temperature thermal diffusivity of any solid naturally occurring or previously synthesized. The laser damage threshold at 193 nm for the isotopically enriched crystal is more than an order of magnitude higher than that of natural diamond.

Evolution of EF-hand calcium-modulated proteins. I. Relationships based on amino acid sequences

Abstract: The relationships among 153 EF-hand (calcium-modulated) proteins of known amino acid sequence were determined using the method of maximum parsimony. These proteins can be ordered into 12 distinct subfamilies--calmodulin, troponin C, essential light chain of myosin, regulatory light chain, sarcoplasmic calcium binding protein, calpain, aequorin, Stronglyocentrotus purpuratus ectodermal protein, calbindin 28 kd, parvalbumin, alpha-actinin, and S100/intestinal calcium-binding protein. Eight individual proteins--calcineurin B from Bos, troponin C from Astacus, calcium vector protein from Branchiostoma, caltractin from Chlamydomonas, cell-division-cycle 31 gene product from Saccharomyces, 10-kd calcium-binding protein from Tetrahymena, LPS1 eight-domain protein from Lytechinus, and calcium-binding protein from Streptomyces--are tentatively identified as unique; that is, each may be the sole representative of another subfamily. We present dendrograms showing the relationships among the subfamilies and uniques as well as dendrograms showing relationships within each subfamily. The EF-hand proteins have been characterized from a broad range of organismal sources, and they have an enormous range of function. This is reflected in the complexity of the dendrograms. At this time we urge caution in assigning a simple scheme of gene duplications to account for the evolution of the 600 EF-hand domains of known sequence.

Nephrotoxicity of vancomycin, alone and with an aminoglycoside

Abstract: The incidence of nephrotoxicity in patients receiving vancomycin alone or in combination with an aminoglycoside was prospectively evaluated. A total of 231 courses of antibiotic therapy in 224 patients were consecutively monitored over 28-month period. One hundred and sixty-eight patients received vancomycin alone, 63 patients received vancomycin with an aminoglycoside, and 103 patients received gentamicin. Nephrotoxicity was defined as an increase in serum creatinine of 0.5 mg/dl or a 50% increase above baseline, whichever was greater. Eight patients (5%) receiving vancomycin alone, 14 patients (22%) receiving vancomycin with an aminoglycoside, and 11 patients (11%) receiving gentamicin alone were found to have nephrotoxicity. Factors found to be associated with increased risk of nephrotoxicity in patients receiving vancomycin were concurrent therapy with an aminoglycoside, length of treatment with vancomycin (greater than 21 days), and vancomycin trough serum concentration (greater than 10 mg/l). Although the incidence of vancomycin nephrotoxicity is low, patients receiving vancomycin therapy with the above risk factors should be closely monitored.

Expression of CYP1A1 Gene in Patients With Lung Cancer: Evidence for Cigarette Smoke-Induced Gene Expression in Normal Lung Tissue and for Altered Gene Regulation in Primary Pulmonary Carcinomas

Abstract: The major polycyclic aromatic hydrocarbon inducible-cytochrome P4501A1 gene (CYP1A1) is presumed to be important in pulmonary carcinogenesis and toxicology because its product, the cytochrome P4501A1-dependent (CYP1A1-dependent) monooxygenase, transforms selected xenobiotics (including polycyclic aromatic hydrocarbon procarcinogens in cigarette smoke) to potent carcinogenic metabolites. CYP1A1 messenger RNA (mRNA) expression has not, however, been previously demonstrated in human pulmonary tissue. This report defines CYP1A1 gene expression in normal lung tissue and primary pulmonary carcinoma tissue obtained at thoracotomy from 56 patients with lung cancer. When Northern blot hybridization analyses were performed, 17 of 19 (89%) and zero of five (0%) samples of normal lung tissue from active cigarette smokers and nonsmokers, respectively, expressed the normal 2.8-kilobase CYP1A1 mRNA. In addition, a time-dependent decrease in expression of the CYP1A1 gene was noted in normal lung tissue from individuals who were former smokers, with a decrease in expression occurring as early as 2 weeks following cessation of cigarette smoking. Expression became undetectable in all patients who had stopped smoking more than 6 weeks prior to study. When CYP1A1 gene expression was evaluated in lung cancers, mRNA levels were detectable in one of four (25%) tumors from nonsmokers; two of 24 (8%) tumors from former smokers; and seven of 15 (47%) tumors from cigarette smokers. In addition, an approximately 10-kilobase CYP1A1 RNA species, which was not detectable in normal lung tissue, was observed in five of ten (50%) of the lung cancers that expressed the CYP1A1 gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergence of alcohol expectancies in childhood: a possible critical period.

Abstract: Previous investigations with adolescents (aged 12-19) have shown alcohol-related expectancies to develop in childhood prior to significant drinking experience and to covary directly with drinking behavior. To chart the development of alcohol expectancies in children as young as age 6, a procedure was developed to be as independent as possible of age-related variation in reading and language development. This instrument was administered to 114 elementary school children of both genders, distributed across grades 1 to 5. Psychometric analysis provided evidence of the test's reliability and validity. Evaluation of the developmental pattern produced two primary findings: (1) there was an overall trend of increasingly positive expectancies with age; and (2) strikingly, the bulk of the increase was observed in the third and fourth grades. Children's expectancies may be less differentiated than adolescent or adult expectancies. These findings suggest that the precursors for later alcohol use and abuse are formed in childhood and that prevention efforts may need to begin as early as third grade.

Decentralized control and coordination of discrete-event systems with partial observation

Abstract: Decentralized supervision and coordination are studied for partially observed discrete-event systems. The authors' (1988) previous results on decentralized supervision and supervision under partial observation are extended by incorporating both these features in the control structure. In addition, a concept of coordination is introduced, and conditions for the existence of a coordinating supervisor are established. It is concluded that decentralized supervision will be easier to design and implement that centralized supervision; under suitable conditions it will be equivalent with respect to overall closed-loop system behavior. In achieving this equivalence a key role is played by the linguistic property of normality. As shown by an illustrative example, the results have application to such complex systems as manufacturing systems, which the qualitative modeling framework adopted. >

Induction of tolerance in peripheral T cells with monoclonal antibodies.

Abstract: Our goal has been to develop ways to tolerize the mature immune system to any defined antigen. In this report we show that peripheral (post-thymic) T cells of mice can become tolerant to a range of antigens (human and rat immunoglobulins, and bone marrow and skin grafts that differ at multiple minor transplantation antigens). In the case of human gamma globulin (HGG), this required that the antigen be given under the cover of a short course of non-depleting anti-CD4 antibody, while for tolerance to skin and marrow grafts anti-CD8 antibody was also required. Tolerance to HGG could be reinforced by repeated injections of HGG, but was lost in the absence of any further exposure to antigen. This reversal of tolerance with time was due to new T cells being exported from the thymus, as it was not observed in tolerized, adult thymectomized mice. In contrast, tolerance to marrow and skin grafts was permanent, presumably because the established grafts acted as a continuous source of antigen to reinforce the tolerant state. Tolerance could not be broken by the infusion of unprimed spleen cells and in one example (tolerance to Mls-1a) there was clear evidence that specific peripheral T cells were anergic. We propose that anergic cells may themselves participate in reinforcing the tolerant state by competing at sites of antigen presentation.

Entropy nets: from decision trees to neural networks

Abstract: How the mapping of decision trees into a multilayer neural network structure can be exploited for the systematic design of a class of layered neural networks, called entropy nets (which have far fewer connections), is shown. Several important issues such as the automatic tree generation, incorporation of the incremental learning, and the generalization of knowledge acquired during the tree design phase are discussed. A two-step methodology for designing entropy networks is presented. The methodology specifies the number of neurons needed in each layer, along with the desired output, thereby leading to a faster progressive training procedure that allows each layer to be trained separately. Two examples are presented to show the success of neural network design through decision-tree mapping. >

Defensive Behavior in Organizations: A Preliminary Model

Abstract: The literature on organizational politics has focused on the proactive promotion of self-interests but has neglected the reactive defense of self-interests. Defensive behaviors are argued to: (1) avoid action, via over-conforming, passing the buck, playing dumb, depersonalizing, smoothing and stretching, and stalling, (2) avoid blame via buffing, playing safe, justifying, scapegoating, misrepresenting, and escalating commitment, and (3) avoid change via resisting change and protecting turf. Organizational antecedents of defensiveness include bureaucratic rationality and various stressors, and individual antecedents include insecurity and anxiety, emotional exhaustion, work alienation, self-monitoring, and low self-efficacy. The effects of defensiveness on the individual, recipients, and organization are discussed, and directions for future research are presented.

Blunt Trauma during Pregnancy

Abstract: THE most common causes of blunt maternal injury during pregnancy are motor vehicle accidents, falls, and assaults1 2 3 4 5 Although trauma is the leading cause of nonobstetrical death in pregnant women in at least one state,6 it causes the death of the fetus much more often than the death of the mother7 8 9 10 11 The management of trauma during pregnancy requires special considerations, because pregnancy alters maternal physiology and because the fetus is a second potential victim Fetal Physiology The effect of trauma on pregnancy depends on the gestational age of the fetus, the type and severity of the trauma, and the extent of

Thyroid Dysfunction in Adults Over Age 55 Years: A Study in an Urban US Community

Abstract: • The prevalence of thyroid dysfunction was determined in a healthy urban population over the age of 55 years. A highly sensitive serum thyrotropin assay was used initially to screen 968 subjects. Elevated values (>6 mU/L) were found in 7.3%, while suppressed values ( (Arch Intern Med. 1990;150:785-787)

Surgical suture carrier and method for urinary bladder neck suspension

Abstract: A suturing needle assembly used in a surgical operation to correct anatomical stress urinary incontinence, the suturing needle assembly having a needle and a sheath. The needle has an elongated flexible portion and a rigid portion which defines a tip for piercing tissue and an eyelet for removably attaching surgical thread. The sheath may selectively envelop the needle when it is beneficial to protect the patient and surgeon from the sharp tip. The flexibility and length of the needle and the sheath allow the suturing needle assembly to navigate a contoured internal passageway such as a female reproductive tract. According to a method of the present invention, the suturing needle assembly, laden with surgical thread, is inserted into a patient's vagina and guided to an operating site at the superior wall of the vagina below the urinary bladder neck. At the operating site, the needle tip is thrust through the superior wall of the vagina and into the retropubic space a sufficient number of times so that the superior wall of the vagina may be elevated and bound to structures in the retropubic space. As a result, problems of stress urinary incontinence are alleviated using the suturing needle assembly in a procedure which avoids needle stick of the surgeon's fingers.

The geometry of evolution.

Abstract: Some structures are more suitable for self-organization through the Darwin-Wallace mechanism of variation and selection than others. Such evolutionary adaptability (or evolvability) can itself evolve through variation and selection, either by virtue of being associated with reliability and stability or by hitchhiking along with the advantageous traits whose appearance it facilitates. In order for a structure to evolve there must be a reasonable probability that genetic variation carries it from one adaptive peak to another; at the same time the structure should not be overly unstable to phenotypic perturbations, as this is incompatible with occupying a peak. Organizations that are complex in terms of numbers of components and interactions are more likely to meet the peak-climbing condition, but less likely to meet the stability condition. Biological structures that are characterized by a high degree of component redundancy and multiple weak interactions satisfy these conflicting pressures.