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PubMedDate not supplied

[The importance of a theory ... the conceptual model by Dorothea E. Orem].

The necessity to care by theoretical thinking and a scientific method is recognized. We have to abandon the task-oriented care model in order to consider a method based on theory to guide our practice. The importance of a Nursing theory depends on its utility in caring and in the disciplinary development. Nurses must learn to be an autonomous profession, based on scientific and theoretical knowledge. Many nursing Scientists have elaborated their own model or theory useful to the Nursing discipline. One of these, is D. Orem's conceptual framework that has defined "self-care" as a human need. In the frame of self care, she has identified the function of Nursing.

Evidence-Based Medicine↗
PubMedDate not supplied

The role of self-discrepancy theory in understanding post-traumatic brain injury affective disorders: a pilot study.

This pilot study examined the utility of self-discrepancy theory (SDT) in explaining post-traumatic brain injury (TBI) depression and anxiety. The SDT model was expanded to include the discrepancy between the postinjury self and the preinjury self. Study participants were 21 individuals with mild to severe TBI residing in the community, who completed the Selves Interview, the Selves Adjective Checklist, the Beck Depression Inventory-II and the Beck Anxiety Inventory. Strong correlations were found between affective distress and self-discrepancies, as measured by the checklist. Scores on the interview were not related to affective distress. The findings suggest that further research is merited to examine the utility of the SDT in addressing issues of post-TBI depression and anxiety.

Adaptation, Psychological↗
PubMed1999

Caring: theoretical perspectives of relevance to nursing.

Caring as a central concept within nursing has led to the development of several caring theories, the most well known being Madeleine Leininger's Theory of Culture Care and Jean Watson's Theory of Human Caring, both of which were formulated in the 1970s. This paper explores a total of four caring theories: the two established theories presented by Leininger and Watson, Simone Roach's theory developed in the 1980s, and a recent caring theory developed by Boykin & Schoenhofer. A comparison of these theories is presented drawing on a number of criteria, namely: origin of theory, scope of theory, definition of caring, description of nursing, key concepts of the theory, and goal/outcome. Additionally, simplicity as a central component of internal structure is examined in relation to each. Based on this analysis, similarities and differences are highlighted, concluding with a discussion of the utility of the caring theories within nursing practice.

Clinical Competence↗
PubMed1995

[Qualitative approach: a contribution to nursing].

This paper focus on some characteristics of the qualitative methodology. Some of these methods are explored such as: participatory research, phenomenology, grounded theory and ethnography critical theory Perspectives of their utilization in nursing research are examined.

Ethnology↗
PubMed1975

The current status of research in the catecholamine theories of affective disorders.

The catecholamine theory suggests that there is a functional deficit of the catecholamine neurotransmitter, norepinephrine (NE) or dopamine (DA) at the neuronal synaptic cleft in depression and an excess in mania. Current strategies which are being utilized to investigate this theory involve: 1)studies of DA, NE, their breakdown products and synthetic and degradative enzymes in body fluids and brain tissue; 2) studies of modes of action of drug which can "activate" or decrease manic or depressive symptoms; 3) the study of pharmacological agents which affect specific aspects of NE and DA metabolism, (synthesis, release, receptor sensitivity, and degradation). The total accumlated data seems more compatible with a catecholamine hypothesis of mania than one of depression. The evidence to date does not allow one to differentiate between the importance of DA or NE either in depression of mania.

Affective Symptoms↗
PubMedDate not supplied

Utilization of macrophages in anticancer therapy: the macrophage network theory.

Appropriate and rational modulation of innate immunity may enhance the therapeutic efficacy of emerging immune therapies for treating cancer. One of the crucial cells of innate immunity is the macrophage. The purpose of this article was to review those issues that suggest ways of exploiting macrophage local functions in immune therapy, and to discuss the suitability of low molecular-weight lipopolysaccharides as potent modulators of macrophage functions for immune therapy of cancer.

Animals↗
PubMed2002

Advancing the expectancy concept via the interplay between theory and research.

Four papers from a 2001 Research Society on Alcoholism symposium on expectancy theory and research are summarized. The symposium contributors describe recent advances in expectancy theory and discuss their implications for assessment and for understanding the processes of development and change in the behavioral domain of alcohol use. First, findings are integrated across the diverse domains in which the expectancy concept has been applied. Second, the implications of expectancy theory for the measurement of expectancy structure and process are examined. Third, research and theory regarding alcohol expectancy development and change are presented, with an emphasis on the role of expectancies as mediators of known antecedents of drinking. Finally, an experimental procedure for investigating the causal role of expectancies is described, together with its implications for theory testing and prevention or intervention programming. Collectively, the symposium contributions demonstrate the utility of an integrated expectancy theory for the generation of innovative research operations and new insights regarding behavior development and change. Consistent with the notion of consilience, expectancy theory has demonstrated a convergence of findings across different levels of analysis, as well as across different operations, methods, and research designs.

Alcohol Drinking↗
PubMed2005

Searching on patch networks using correlated random walks: space usage and optimal foraging predictions using Markov chain models.

We describe a novel representation of a discrete correlated random walk as the transition matrix of a Markov chain with the displacements as the states. Such a representation makes it possible to utilize results from the theory of absorbing Markov chains, to make biologically interesting predictions without having to resort to Monte Carlo simulations. Our motivation for constructing such a representation is to explore the relationship between the movement strategy of an animal searching for resources upon a network of patches, and its consequent utilization of space and foraging success. As an illustrative case study, we have determined the optimal movement strategy and the consequent usage of space for a central place forager utilizing a continuous movement space which is discretized as a hexagonal lattice. The optimal movement strategy determines the size of the optimal home range. In this example, the animal uses mnemokinesis, which is a sinuosity regulating mechanism, to return it to the central place. The movement strategy thus refers to the choice of the intrinsic path sinuosity and the strength of the mnemokinetic mechanism. Although the movement space has been discretized as a regular lattice in this example, the method can be readily applied to naturally compartmentalized movement spaces, such as forest canopy networks. This paper is thus an attempt at incorporating results from the theory of random walk-based animal movements into Foraging Theory.

Animals↗
PubMed2005

Model identity SN2 reactions CH3X + X- (X = F, Cl, CN, OH, SH, NH2, PH2): Marcus theory analyzed.

The structures of seven gas phase identity S(N)2 reactions of the form CH(3)X + X(-) have been characterized with seven distinct theoretical methods: RHF, B3LYP, BLYP, BP86, MP2, CCSD, and CCSD(T), in conjunction with basis sets of double and triple zeta quality. Additionally, the energetics of said reactions have been definitively computed using focal point analyses utilizing extrapolation to the one-particle limit for the Hartree-Fock and MP2 energies using basis sets of up to aug-cc-pV5Z quality, inclusion of higher order correlation effects [CCSD and CCSD(T)] with basis sets of aug-cc-pVTZ quality, and additional auxiliary terms for core correlation and scalar relativistic effects. Final net activation barriers for the reactions are E(b)(F,F)= -0.8, E(b)(Cl,Cl)= 1.6, E(b)(CN,CN)= 28.7, E(b)(OH,OH)= 14.3, E(b)(SH,SH)= 13.8, E(b)(NH2,NH2)= 28.6, and E(b)(PH2,PH2)= 25.7 kcal mol(-1). General trends in the energetics, specifically the performance of the density functionals, and the component energies of the focal point analyses are discussed. The utility of classic Marcus theory as a technique for barrier predictions has been carefully analyzed. The standard Marcus theory results show disparities of up to 9 kcal mol(-1) with respect to explicitly computed results. However, when alternative approaches to Marcus theory, independent of the well-depths, are considered, excellent performance is achieved, with the largest deviations being under 3 kcal mol(-1).

Journal Article↗
PubMed1999

Selecting the most informative items in the IIP scales for personality disorders: an application of item response theory.

The first goal of the present analyses was to shorten the five scales (Pilkonis, P. A., Kim, Y., Proietti, J. M., & Barkham, M. [1996]. Journal of Personality Disorders, 10, 355-369) for personality disorders (PDs) developed from the Inventory of Interpersonal Problems (IIP), thereby increasing their attractiveness for screening purposes. The second goal was to illustrate, for more general purposes, the utility of item response theory (IRT) for such scale refinement. IRT analyses were performed using data collected from six different samples (N = 1149) at five sites and a two-parameter (2P) graded model designed for multiple response items like those on the IIP. The five most informative items from each scale were identified, based on the magnitude of item discrimination parameters and the range and elevation of individual item information functions. Preliminary analyses of the reliability and validity of the short forms of the scales (totaling 25 items) supported their value as alternatives to the longer forms (consisting of 47 items), although definitive tests of their psychometric properties await crossvalidation in independent samples. Analyses of the quality receiver operating characteristics (QROC) of the long and short forms showed that both versions can be useful in predicting the presence versus absence of any PD diagnosis arrived at by using either a "best estimate" clinical consensus method or a structured Axis II interview.

Adult↗
PubMed1999

A generalizability study of the Eating Attitudes Test (EAT-12) in non-clinical adolescents.

One of the most frequently used measures of eating and weight problems is the Eating Attitudes Test (EAT). The paper discusses conceptual heterogeneity in the EAT in the light of eating disorder continuum theory. Psychometric qualities of the Norwegian 12-item version of the EAT was based on a sample of 224 female and 261 male adolescents aged 14-15 years. Generalizability theory enabled us to study the impact of multiple sources of measurement errors of the EAT-12. The analyses suggest that acceptable generalizability is achieved by the present design on applying 4 items within 3 categories of the EAT. Alternative designs are suggested, and the utility of G-theory is discussed. The results also provide evidence of a gender difference in the structure of the universe score variance. Non-clinical adolescents' ways of organizing information about food and eating are discussed in the light of gender differences.

Adolescent↗
PubMed2005

Anxiety disorders in childhood: casting a nomological net.

Empirical research highlights the need for improving the childhood anxiety disorder diagnostic classification system. In particular, inconsistencies in the stability estimates of childhood anxiety disorders and high rates of comorbidity call into the question the utility of the current DSM criteria. This paper makes a case for utilizing a nomological net model for advancing the understanding of childhood anxiety disorders. In this article, we discuss measurement and assessment issues related to improving the childhood anxiety disorder diagnostic system and show how these issues can be addressed by employing the nomological net of childhood anxiety. Because employing the nomological net involves drawing from etiological process theories to facilitate classification and assessment, an integrative model of childhood anxiety disorders is presented as a tentative heuristic. Then evidence for the existing symptom sets is discussed in the context of how process theory mechanisms may be utilized to improve classification and assessment. Testable hypotheses are presented. Measurement, disorder definition, treatment, and policy implications are also discussed.

Anxiety Disorders↗
PubMed2006

Stimulus equivalence: testing Sidman's (2000) theory.

Sidman's (2000) theory regarding the origin of equivalence relations predicts that a reinforcing stimulus common to distinct equivalence classes must drop out of the equivalence relations. This prediction was tested in the present study by arranging class-specific reinforcers, R1 and R2, following correct responding on the prerequisite conditional discriminations (Ax-Bx, Cx-Bx) for two stimulus classes, A1B1C1 and A2B2C2. A class-common reinforcer, R3, was presented following correct responding on the prerequisite conditional discriminations for a further two stimulus classes, A3B3C3 and A4B4C4. Sidman's theory predicts reinforcer inclusion within Classes 1 and 2 only, given this training arrangement. Experiment 1 tested for the emergence of four equivalence classes and of stimulus-reinforcer and reinforcer-stimulus relations in each class. Four of the 6 subjects demonstrated the reinforcer-based relations in all four equivalence classes, rather than in only those classes with a class-specific reinforcer, as Sidman's theory predicts. One of the remaining 2 subjects showed the reinforcer-based relations in three of the four classes. Experiment 2 extended these findings to document the emergence of interclass matching relations based on the common reinforcer R3, in 5 of 6 subjects, such that a Class 3 sample occasioned the selection of a Class 4 sample when the Class 3 comparison was absent, and similarly, a Class 4 sample occasioned the selection of a Class 3 comparison when the Class 4 comparison was absent. These interclass relations emerged despite the simultaneous maintenance of Class 3 and 4 baseline conditional discriminations, so that the Class 3 and 4 stimuli and reinforcer simultaneously were, and were not, part of a single larger equivalence class. These data are irreconcilable with Sidman's theory, and question the utility of the application of the equivalence relation in describing derived stimulus relations.

Adult↗
PubMed1993

Stationary and automated laparoscopically assisted technologies.

The extent that laparoscopy may impact upon the practice of surgery remains to be clarified. One problem with these techniques is the maintenance of an adequate, stationary visual field in morphometrically different abdomens. This requires the attentive, trained, and skillful utilization of someone or something to operate the camera portal. Herein reported are the theory, advantages, disadvantages, and clinical utilization of mechanical and robotic arm systems to replace this second assistant during laparoscopic surgery.

Humans↗
PubMed1992

Mid-range theory building and the nursing theory-practice gap: a respite care case study.

Nursing, with its historical roots in practice, has tended to have an uneasy relationship with theory. Whilst the benefits of theory to nursing have been propounded by many commentators, it remains that theory all too rarely informs nursing practice. This paper argues for the development and utilization of mid-range theories as representing a solution to this problem. The advantages of such an approach are illustrated by the application, testing and refinement of Chenitz's theory of relocation to a hospital-based respite care scheme for the frail elderly.

Adaptation, Psychological↗
PubMed2002

Teaching implications of different educational theories and approaches.

Educational theory can and should form the basis for teaching in veterinary medicine. Nevertheless, formal training for teachers in veterinary medicine is uncommon and rarely includes study of different educational theories or perspectives, leaving educators to rely on informal or "hidden" educational constructs to guide them in their everyday teaching. Using a modified case-based format, we present critiques of a hypothetical teaching scenario from four different educational viewpoints: behaviorist, cognitive, social learning, and inspired teaching approaches. The importance and utility of formal educational theory in faculty development is discussed.

Education, Veterinary↗
PubMed1980

Pharmacokinetics of ethanol: a review.

The pharmacokinetics of ethanol in man are reviewed from a historical perspective from the earliest attempts at kinetic analysis of urinary data in 1899 to the present nonlinear analysis of blood alcohol concentration (BAC) and time data. Review of the various kinetic theories that have been utilized to describe the kinetics of alcohol metabolism is provided. Extensive review is made of recent investigations supporting the application of Michaelis-Menten enzyme kinetics to describe alcohol metabolism. Results of direct, nonlinear least-squares computer fitting of BAC following intravenous and oral feeding of alcohol both in the fasting and fed states are presented with appropriate theory. The kinetics of the oral absorption of alcohol and the relationship among stomach emptying rate, the apparent absorption rate, and the area under the BAC-time curve are discussed and data presented. The kinetics of multiple Michaelis-Menten pathways are discussed with application to the (potential) contributions of the MEOS and/or ADH systems to the observed BAC curve and resultant kinetic parameters. Several methods of obtaining pharmacokinetic (Michaelis-Menten) parameters from BAC curves and their interpretation and usage in comparative studies are presented.

Ethanol↗