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Results for “Utility Theory”

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PubMed2003

[Health promotion--a new approach in psychiatry].

Since its beginnings, the ideology of psychiatry has been determined by the paradigm of a disease model. Practically all psychiatric schools are characterized by their orientation towards a morbid, atypical behaviour. This, however, inevitably narrows the view of the soul of a person. Despite mental illness, resources are always present, these though are not recognized and not utilized. The theory of salutogenesis with its search for health preserving factors has significantly expanded insight on dynamic mental processes. The resulting concept of health promotion attempts to develop patient's self-healing powers by identifying healthy parts and supporting them by instructing patients in active participation. From a health promotion viewpoint, it is necessary to intervene at three levels: 1. At the patient level in the form of guidance and help to actively participate in the healing process. 2. At the staff level in the form of creating healthy work conditions and the promotion of active participation in the creation of this work environment. 3. At the level of psychiatric institutions in the form of promoting efficient communications structures within and between the various services. This paper describes the concept of health promotion in psychiatric services and its possible influence on the reshaping of theory and practice in psychiatry--necessary in the face of current challenges.

Adaptation, Psychological↗

PubMed2005

A theoretical study for the reaction of vinyl cyanide C2H3CN(X1A') with the ground state carbon atom C(3P) in cold molecular clouds.

The reaction of the ground state atomic carbon, C(3P), with simple unsaturated nitrile, C2H3CN(X1A' (vinyl cyanide), is investigated theoretically to explore the probable routes for the formation of carbon-nitrogen-bearing species in extraterrestrial environments particularly of ultralow temperature. Five collision complexes without entrance barrier as a result of the carbon atom addition to the pi systems of C2H3CN are characterized. The B3YLP/6-311G(d,p) level of theory is utilized in obtaining the optimized geometries, harmonic frequencies, and energies of the intermediates, transition states, and products along the isomerization and dissociation pathways of each collision complex. Subsequently, with the facilitation of computed RRKM rate constants at collision energy of 0-10 kcal/mol, the most probable paths for each collision complexes are determined, of which the CCSD(T)/6-311G(d,p) energies are calculated. The major products predicted are exclusively due to the hydrogen atom dissociations, while the products of H2, CN, and CH2 decompositions are found negligible. Among many possible H-elimination products, cyano propargyl (p4) and 3-cyano propargyl (p5) are the most probable, in which p5 can be formed via two intermediates, cyano allene (i8) and cyano vinylmethylene (i6), while p4 is yielded from i8. The study suggests this class of reaction is an important route to the synthesis of unsaturated nitriles at the temperature as low as 10 K, and the results are valuable for future chemical models of interstellar clouds.

Journal Article↗

PubMed2005

Calculation of optical rotation with time-periodic magnetic-field-dependent basis functions in approximate time-dependent density-functional theory.

We report the implementation of a method for the calculation of optical rotation. This method is based on the time-dependent density-functional theory and utilizes time-periodic magnetic-field-dependent basis functions. The calculations are based on a density fit. It is demonstrated that additional terms in the analytical expression appearing from derivatives of the approximated Coulomb potential are necessary to provide the gauge-origin independence of the results within a given numerical accuracy. Contributions from these terms also restore the symmetry between the electric and magnetic perturbations in the optical rotation tensor.

Algorithms↗

PubMed2006

Charge transfer interaction in the effective fragment potential method.

An approximate formula is derived and implemented in the general effective fragment potential (EFP2) method to model the intermolecular charge transfer interaction. This formula is based on second order intermolecular perturbation theory and utilizes canonical molecular orbitals and Fock matrices obtained with preparative self-consistent field calculations. It predicts charge transfer energies that are in reasonable agreement with the reduced variational space energy decomposition analysis. The formulas for the charge transfer gradients with respect to EFP translational and rotational displacements are also derived and implemented.

Chemistry, Physical↗

PubMed2006

Calculation of origin-independent optical rotation tensor components in approximate time-dependent density functional theory.

We outline an implementation of the origin-independent optical rotation tensor, which includes electric dipole-magnetic dipole and electric dipole-electric quadrupole polarizability. The method is based on approximate time-dependent density functional theory. We utilize time-periodic magnetic-field-dependent basis functions as well as a modified velocity-gauge formulation of dynamic polarizability tensors in order to obtain a gauge-origin independence. To ensure gauge-origin independence of the results within a given numerical accuracy, density fit coefficient derivatives are employed. A damping constant has been introduced into the linear response equations to treat both resonance and nonresonance regions of optical activity. We present calculations for trans-2,3-dimethyloxirane and derivatives thereof as well as calculations for androst-4,17-dien-3-one. In the Appendix, we derive the equivalence between the common-gauge origin and gauge-including atomic orbitals formulations for the optical rotation tensor in time-dependent DFT.

Journal Article↗

PubMed1998

UK consumer attitudes, beliefs and barriers to increasing fruit and vegetable consumption.

OBJECTIVES: To assess attitudes, predictors of intention, and identify perceived barriers to increasing fruit and vegetable (F&V) intakes. DESIGN: UK nationwide postal survey utilizing the theory of planned behaviour. SUBJECTS: Stratified (by social class and region) random sample of 2020 UK adults providing a modest response rate of 37% (n = 741). RESULTS: Belief measures (e.g. health, cost, taste, etc.) were strongly associated with overall attitudes which were reported as being largely favourable towards fruit, vegetables and, to a lesser extent, vegetable dishes, and were strongly associated with reported intention to increase consumption. Subjects reported they could increase their consumption, but this was only weakly associated with intention to do so. Approximately 50% of respondents reported an intention to increase intakes. Social pressure was strongly associated with reported intention to increase; however, scores indicated low perceived social pressure to change. Evidence of unrealistic optimism concerning perceived intakes and the perceived high cost of fruit may also act as barriers. CONCLUSIONS: Results from this study suggest a lack of perceived social pressure to increase F&V intakes and suggests that public health efforts require stronger and broader health messages that incorporate consumer awareness of low present consumption.

Adolescent↗

PubMed1997

Strain Concentrations Surrounding an Ellipsoid Model of Lacunae and Osteocytes.

Direct cell sensing of tissue matrix strains is one possible signaling mechanism for mechanically mediated bone adaptation. We utilized homogenization theory to estimate bone tissue matrix strains surrounding osteocytes using two sets of models. The first set of models estimated the strain levels surrounding the lacunae and canaliculi, taking into account variations in lamellar properties. The second set estimated strain levels in the osteocyte and the surrounding matrix for different cellular mechanical properties. The results showed that the strain levels found in and surrounding osteocytes, 1700 to 2700 microstrain (denoted as µe; 1 µe =.0001% strain), were significantly greater than the trabecular tissue level strains of {1325 µe, 287 µe, 87 µe} used for model input. Variation in lamellar properties did not affect strain levels, except at lamellar boundaries. Strain in and surrounding the osteocyte was not significantly affected by cellular stiffness ranging between 28 and 28, 000 Pascals (Pa). Strain levels surrounding lacunae and canaliculi were approximately equivalent.

Journal Article↗

PubMed2005

Acute versus primary care: the health care decision making process for individuals with severe mental illness.

OBJECTIVES: This study's purpose was to determine factors influencing treatment choices of individuals with severe mental illness (SMI). The sample was drawn from admissions to residential crisis programs in San Francisco. Inclusion criteria were an Axis I and Axis III disorder. METHODS: This qualitative study utilized grounded theory method. Interviews and field notes were coded for recurring themes. Descriptive data were also collected. RESULTS: Participants revealed that the most important influences on treatment decisions were immediate need for care, the belief that their subacute complaints will not be taken seriously by providers, positive reinforcement for emergency service use, and enabling factors such as insurance coverage. Other remarkable findings included: numerous reports of substance induced medical crises, lack of support from family, and unawareness of client's medical conditions in psychiatric facilities. CONCLUSIONS: Health care seeking behaviors are learned and learning that will promote the use of outpatient services in SMI must include positive experiences in the delivery of care in the primary care setting. Participants were knowledgeable regarding their illnesses and able to articulate symptoms of illness well. Failure to communicate symptoms appeared to reflect the participant's perception of a lack of response to their reports.

Adult↗

PubMed1986

Human capital and the rise and fall of families.

"This paper develops a model of the transmission of earnings, assets, and consumption from parents to descendants. The model assumes utility-maximizing parents who are concerned about the welfare of their children. The degree of intergenerational mobility is determined by the interaction of this utility-maximizing behavior with investment and consumption opportunities in different generations and with different kinds of luck. We examine a number of empirical studies for different countries. Regression to the mean in earnings in rich countries appears to be rapid. Almost all the earnings advantages or disadvantages of ancestors are wiped out in three generations." A comment by Robert J. Willis is included (pp. 40-7).

Behavior↗

PubMed1997

Clinical diagnosis: a marker for disease?

In the science of psychiatry, a careful logic has linked items of phenomenology to diagnoses and hypothesized disease constructs. However, the resultant improved reliability of diagnostic assessment does not directly ensure the specificity and validity of diagnosis, and diagnoses are often thought of as identical to diseases. Although specificity is enhanced by the use of patterns of items of phenomenology operationalized into diagnoses to classify psychiatric disease, evidence suggests that diagnostic heterogeneity remains significant, limiting specificity. Furthermore, diagnostic concepts may bias assessments of phenomenology. Theoretically, psychiatric diseases are pathological states of neurobiological, social, and psychological processes and interactions. Although advances in social and psychological science continue, neurobiological science is advancing rapidly and is expected to contribute substantially to validity. But the relative psychometric distance and sources of measurement error between these underlying aspects of diseases and manifest phenomenology suggest that the use of clinical diagnoses, derived from phenomenology, may not be optimal as a standard from which to test neurobiological hypotheses, limiting validity. The authors submit that an approach utilizing measurement theory to combine standardized assessment of symptom items with neurobiological observations for classification will assist in efforts to understand the complexities of psychiatric disorders. Incorporation of neurobiological (and other) measures into the diagnostic logic has potential to extend and refine definitions of psychiatric diseases. A subtle shift of paradigm is suggested, in which clinical diagnosis is thought of not as the definition of disease, but as a marker for disease.

Biomarkers↗

PubMed1983

Ethical dimensions of nursing practice.

Nurses are often called upon to participate in ethical decision-making. As the dimensions of nursing care increase, this role will also increase. This article has provided some strategies by which the nurse can come to an independent, personal decision; understand why the stance was chosen; and articulate the rationale for the choice to others. Obviously, this article is not meant to provide the sole groundwork for ethical decision-making, but rather an impetus for the practicing nurse to seek more information on ethics and the ethical dimensions of her own practice. Resolving ethical dilemmas will never be easy; however, by utilizing the theories and models presented here, the nurse can contribute to a responsible ethical decision. The Blackfoot Indian tribe has a philosophy regarding ethical choice that seems appropriate: "Everything is neither right nor wrong. The right or wrong is in the choosing, the keeping, the losing. All paths are light and shadow, and every path is a different thing to each man. The right and the wrong, the good and the evil lie not upon the silent pathway, but in the man that walks it..."

Decision Making↗

PubMed2006

Formation and splitting of paired hydroxyl groups on reduced TiO2(110).

A combination of high-resolution scanning tunneling microscopy and density functional theory is utilized to study the interaction of water with the reduced TiO2(110)-(1 x 1) surface. As the direct product of water dissociation in oxygen vacancies, paired hydroxyl groups are formed. These pairs are immobile and stable unless they interact with adsorbed water molecules. As a result of these interactions, protons are transferred to adjacent oxygen rows, thereby forming single hydroxyl groups. Additionally, we show that hydroxyl groups facilitate the diffusion of water molecules over the oxygen rows.

Journal Article↗

PubMed1978

The continual assessment of medical students.

At the new Medical Faculty at the University of Dar-es-Salaam (East Africa) a number of innovations were instituted. The most significant was continual assessment of students. During the first 3 years of the course, results of weekly testing may comprise three-fourths of each student's assessment. Later they are assessed on each rotation and clerkship; and these must be completed satisfactorily before Final Examinations are taken. These assessments never contribute less than one-half of the final results. Failures were reduced from 10 to 2% with no reduction in standards or performance levels. The method utilizes Reinforcement Theory techniques; specifically referred to are schedules of testing, grades as reinforcers, and frequent feed-back for students, self-shaping of study strategies and for constant surveilance of its teaching by the Faculty.

Curriculum↗

PubMed1994

The model of place utility revisited.

"The purpose of this paper...is twofold: first, to specify a way of calculating place utility so that potential migrants could move to the place where overall place utility is maximized; and second, which is more important, to reveal how decision-makers in the real world, who are acting within 'bounded rationalities'...,make their decisions on where to migrate. This study is supported by an empirical survey of recent Chinese immigrants to Edmonton [Canada].... The findings reveal that when people evaluate different places, they do not necessarily look for the one that generates the highest overall value or utility across all properties.... The study further indicates that the assumption underlying most microeconomic models (that maximizing utility or benefit is the ultimate rule for choosing one location out of several) has not been verified." (SUMMARY IN FRE AND SPA)

Americas↗

PubMed2004

Older patients awaiting emergency department treatment.

The aim of this study was to describe, through observations and interviews with patients >/=75 years old and the relatives who accompanied them to the hospital, the conditions at the emergency department (ED) and the events that took place during the waiting period. Twenty older patients were studied, together with their relatives. A modification of a comparative design, the interpretative method 'grounded theory', was utilized. Open, nonparticipant observations were carried out; from the time patients were admitted until the time they were discharged. Patients were observed through all stages, for example, in the reception area, in the examination room, and in the X-ray department. The observations were supplemented with field notes and interviews with the older patients as they left the ED. The selective coding developed into six core-variables that were the focus of the material. These were: unpleasant waiting, unnecessary waiting, lack of good routines during the waiting stage, suffering during the waiting stage, bad feelings during the waiting stage and nursing care during the waiting stage. The way, in which nursing care was carried out, which in this context is discussed in terms of praxis and poieses, appeared to be of major importance for the older peoples' experiences when visiting the ED.

Aged↗

PubMed1995

Fractal dimension analysis of the oscillated blood flow with a vibrating flow pump.

To analyze the hemodynamic parameters during circulation with oscillated blood flow, nonlinear mathematical analyzing techniques, including fractal theory, were utilized. Vibrating flow pumps (VFP) were implanted as a left heart bypass, and the ascending aorta was clamped to constitute the total left heart circulation with oscillated blood flow in acute animal experiments using 7 adult goats. Using nonlinear mathematical analyzing techniques, reconstructed attractors of the arterial blood pressure waveform in the phase space during natural circulation and oscillated circulation were analyzed. Using the Grassberger-Procaccia correlation dimension analyzing technique, fractal dimension analysis of the reconstructed attractor was performed. During VFP bypass, lower fractal dimensions of the reconstructed attractor were shown compared with those during natural heart circulation. The results suggest that lower dimensional chaotic dynamics contributed to the circulation with oscillated blood flow.

Animals↗

PubMedDate not supplied

Assessing postpartum adjustment. A pilot study.

Utilizing crisis theory, the stages of growth and development, and a theory of role transition and enactment, a series of questionnaires was developed as a clinical tool to study women's adaptation to motherhood during six weeks postpartum. The tool was tested on six women. Results suggest that the postpartum is indeed a critical period of identity reformation and role transition. Theories are developed for a framework, and a timetable for nursing intervention is given.

Adaptation, Psychological↗

PubMedDate not supplied

Complications of menopause and the risks and benefits of estrogen replacement therapy.

Every woman who lives long enough will become menopausal. While menopause is not a disease, the increased mortality and morbidity in menopausal women due to osteoporotic fractures, cardiovascular disease, and coronary heart disease are felt by many to be related to the decrease in endogenous estrogen. Therefore, one possible solution is estrogen replacement therapy. This article reviews recent literature on the complications of menopause and the risks and benefits of estrogen replacement therapy. The article also will discuss how a nurse practitioner can utilize the theory of care seeking behavior to implement this knowledge into practice.

Aged↗