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Results for “Knowledge base”

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At least 1,243 records · Page 69Linked to original sources

PubMed2003

Conditional reasoning and conditionalization.

In solving conditional reasoning problems, reasoners are assumed to compute the probability of the conclusion, conditionalizing first on the categorical premise, giving the knowledge-based component, and conditionalizing then on the conditional-statement premise, from which the assumption-based component is derived. Because reasoners find it difficult to compute the second-step conditionalization except when the conditional-statement premise is found to be related to the result of the first-step conditionalization as for modus ponens or, possibly, for modus tollens, the knowledge-based component generally dominates reasoning performance. After representing all the possible cases in which conditional-argument forms may appear, this approach was found to be consistent with the results from the 3 experiments reported in this study, whereas 2 alternative hypotheses account for only some of the results.

Adolescent↗

PubMedDate not supplied

A study of the spatiotemporal health impacts of ozone exposure.

Exposure analysis and mapping of spatiotemporal pollutants in relation to their health effects are important challenges facing environmental health scientists and integrated assessment modellers. In this work, a methodological framework is discussed to study the impact of spatiotemporal ozone (O3) exposure distributions on the health of human populations. The framework, however, is very general and can be used to study various other pollutants. The spatiotemporal analysis starts with exposure distributions producing the input to pollutokinetic (or toxicokinetic) laws which are linked to effect models which, in turn, are integrated with relationships that describe how effects are distributed across populations. Important characteristics of the environmental health framework are holisticity and stochasticity. Holisticity emphasizes the functional relationships between composite space/time O3 maps, pollutokinetic models of burden on target organs and tissues, and health effects. These relationships offer a meaningful physical interpretation of the exposure and biological processes that affect human exposure. Stochasticity involves the rigorous representation of natural uncertainties and biological variations in terms of spatiotemporal random fields. The stochastic perspective introduces a deeper epistemological understanding in the development of improved models of spatiotemporal human exposure analysis and mapping. Also, it explicitly determines the knowledge bases available and develops logically plausible rules and standards for data processing and human exposure map construction. The proposed approach allows the horizontal integration among sciences related to the human exposure problem that leads to accurate and informative spatiotemporal maps of O3 exposure and effect distributions and an integrative analysis of the whole risk case. By processing a variety of knowledge bases, the spatiotemporal analysis can bring together several sciences which are all relevant to the aspect of human exposure reality that is examined.

Body Burden↗

PubMed1990

Object-centered representation for species systematics and identification in living systems in nature.

An artificial intelligence application to identification in biological taxonomy is presented. An object-centered representation is described using SHIRKA, a knowledge-based system developed in France. The capacities of this system, relating to a classification algorithm, are described. An application to the identification of the trees and lianas of the evergreen forests of the Western Ghats (India) is presented to illustrate the problems encountered in the development of the knowledge base. A model of a systematist's reasoning, using evolutionary principles, is the basis of this work. Finally the efficiency of the system is discussed.

Artificial Intelligence↗

PubMed1997

Large scale protein modelling and model repository.

Knowledge-based molecular modelling of proteins has proven useful in many instances including the rational design of mutagenesis experiments, but it has been generally limited by the availability of expensive computer hardware and software. To overcome these limitations, we have developed the SWISS-MODEL server for automated knowledge-based protein modelling. The SWISS-MODEL server uses the Brookhaven Protein Data Bank as a source of structural information and automatically generates protein models for sequences which share significant similarities with at least one protein of known 3D-structure. We now use the software framework of the server to generate large collections of protein models. To store these models, we have established the SWISS-MODEL Repository, a new database for protein models generated by theoretical approaches. This repository is directly integrated with SWISS-PROT and other databases through the ExPASy World-Wide Web server (URL is http:(/)/www.expasy.ch).

Amino Acid Sequence↗

PubMed1990

[Development and clinical application of an expert system for supporting diagnosis of 201Tl stress myocardial SPECT].

A consultation expert system which supports our computer aided reporting system was developed. The system was used for the evaluation of the two dimensional polar (bull's eye) display of 201Tl myocardial SPECT. The system consists of patients management (PM) and consultation expert systems (ES). The former is connected to image processors coupled with scinticameras. The bull's eye display of myocardial SPECT is transferred from image processor to the data base of PM. When inference request is made, the feature extraction program extracts information on localization, extent and severity of focal defects comparing count-rates pixel by pixel with the reference obtained from seven normal controls. The inference engine is activated to determine presence of focal defects utilizing diagnostic rules in the knowledge base. The results are sent back to PM and reported with the probability of assurance. Fifty eight patients with old myocardial infarction (OMI), angina pectoris (AP) and other diseases as well as normal controls were included in the study. The decision for presence or absence of focal defects by ES agreed with that by nuclear physicians (NP) in 301 segments among 330 (91%) in stress images. The presence of redistribution in delayed images agreed in 43 segments among 67 (64%). Image interpretation by ES agreed well with that of NP in patients with OMI (19/20) and AP (9/11). Seven were interpreted as normal by both ES and NP. The system is useful, as it provides NP with complementary and supportive information applicable to decision making and reporting. Further clinical experiences can improve knowledge base for better ES function.

Computer Systems↗

PubMed1998

Social work in health care: do practitioners' writings suggest an applied social science?

There are two sources of literature in social work-one from academics and the other from practitioners. Each group is driven by different motivations to write. Academics seek a 'scientific rationality' for the field, while practitioners assume practical and intuitive reasoning, experience aligned with theory, and the 'art of practice' to guide them. It has been said that practitioners do not write and that 'faculty' are the trustees of the knowledge base of the profession, and are responsible for its promulgation via publication. Practitioners, however, do write about their practice and their programs, and analyze both, but publish much of their work in non-social work media. Their work tends not to be referenced by academic writers. One department's social workers' publications are described. We learn, from their practice writings, what concerns clinicians. Theirs is case-based learning, theoretically supported, in which the organization of services calls for their participation in multi-professional decision-making. There is the growing realization among social workers that practice wisdom and scientific technologies need to be reassessed together to find ways to enhance social work services. Clinicians' knowledge can lead to continuing refinement of practice and enhanced institutional services. If practitioners' writings can be assessed, they may lead to a written practice knowledge base, subject to timely change. Academic and practitioner separateness hampers progress in the field. They need each other, and a shared professional literature. There is beginning indication they are getting together.

Humans↗

PubMed2005

Prediction of HIV-1 protease inhibitor resistance using a protein-inhibitor flexible docking approach.

Emergence of drug resistance remains one of the most challenging issues in the treatment of HIV-1 infection. Here we focus on resistance to HIV-1 protease inhibitors (PIs) at a molecular level, which can be analysed genotypically or phenotypically. Genotypic assays are based on the analysis of mutations associated with reduced drug susceptibility, but are problematic because of the numerous mutations and mutational patterns that confer drug resistance. Phenotypic resistance or susceptibility can be experimentally evaluated by measuring the amount of free drug bound to HIV-1 protease molecules, but this procedure is expensive and time-consuming. To overcome these problems, we have developed a docking protocol that takes protein-inhibitor flexibility into account to predict phenotypic drug resistance. For six FDA-approved Pls and a total of 1792 HIV-1 protease sequence mutants, we used a combination of inhibitor flexible docking and molecular dynamics (MD) simulations to calculate protein-inhibitor binding energies. Prediction results were expressed as fold changes of the calculated inhibitory constant (Ki), and the samples predicted to have fold-increase in calculated Ki above the fixed cut-off were defined as drug resistant. Our combined docking and MD protocol achieved accuracies ranging from 72-83% in predicting resistance/susceptibility for five of the six drugs evaluated. Evaluating the method only on samples where our predictions concurred with established knowledge-based methods resulted in increased accuracies of 83-94% for the six drugs. The results suggest that a physics-based approach, which is readily applicable to any novel PI and/or mutant, can be used judiciously with knowledge-based approaches that require experimental training data to devise accurate models of HIV-1 Pl resistance prediction.

Binding Sites↗

PubMed2000

Implementing clinical practice guidelines while taking account of changing evidence: ATHENA DSS, an easily modifiable decision-support system for managing hypertension in primary care.

This paper describes the ATHENA Decision Support System (DSS), which operationalizes guidelines for hypertension using the EON architecture. ATHENA DSS encourages blood pressure control and recommends guideline-concordant choice of drug therapy in relation to comorbid diseases. ATHENA DSS has an easily modifiable knowledge base that specifies eligibility criteria, risk stratification, blood pressure targets, relevant comorbid diseases, guideline-recommended drug classes for patients with comorbid disease, preferred drugs within each drug class, and clinical messages. Because evidence for best management of hypertension evolves continually, ATHENA DSS is designed to allow clinical experts to customize the knowledge base to incorporate new evidence or to reflect local interpretations of guideline ambiguities. Together with its database mediator Athenaeum, ATHENA DSS has physical and logical data independence from the legacy Computerized Patient Record System (CPRS) supplying the patient data, so it can be integrated into a variety of electronic medical record systems.

Artificial Intelligence↗

PubMed1990

A diagnostic expert system for colonic lesions.

The diagnostic expert system for colonic lesions (DESCL) was designed to discriminate colonic adenoma and adenocarcinoma from normal colonic tissue. Although it was originally developed for use in conjunction with a machine vision analytic system, the DESCL has evolved into a teaching tool and a model for conceptual machine learning. The expert system is table driven and consists of a shell and a knowledge base. The latter comprises a series of architectural and cytologic observations and a quantitative estimate of diagnostic importance relating these observations to diagnostic outcome. In a validation study of 100 colonic lesions, the expert system achieved a success rate of 98%. It has the flexibility to allow individual pathologists to "customize" the knowledge base to suit their diagnostic criteria.

Adenocarcinoma↗

PubMedDate not supplied

Executive summary.

The Canadian health system is at a crossroads. Significant health services restructuring is occurring across the country. This restructuring process provides a unique opportunity for Public Health and others to reorient the system away from illness to a focus on health--the health of individuals and communities. The purpose of this paper is to motivate and equip Public Health workers to take leadership in the restructuring, to outline key responses and strategies for Public Health associations, to raise public awareness about restructuring, and to challenge decision makers to integrate the Public Health perspective into the restructured health system. This Issue Paper describes the unique contributions Public Health has to offer health services restructuring, outlines the Public Health response to specific restructuring issues, and identifies some successful strategies for influencing change. Two key messages are explored in the paper: 1. Restructuring will be successful if it is based on an investment in health. The health of the public can be maintained and improved through changes to the institutional sector and support for health promotion, disease prevention and health protection services. 2. Public Health must be a full partner in the restructuring of health services. The Public Health perspective includes a broad understanding of the issues that are relevant to the health of individuals and communities. The skills and knowledge base offered through Public Health provide balance and equity in decision making, by ensuring full and representative involvement of community workers and the public. The uniqueness of Public Health is manifested in three distinct ways: its approach within an organized system of practice; its historical contribution; and its purposeful combination of perspectives, skills and knowledge. In partnership with communities, other health professionals and other health-determining sectors, Public Health works to protect, maintain and improve the health of Canadians. While other sectors undertake some of the functions outlined below, what makes Public Health unique is that these contributions are offered collectively through an organized system of practitioners to create a synergistic effect. Eight contributions of Public Health are identified in this paper. Specifically Public Health: Focuses on individuals and communities in a societal and global context. Builds capacity in individuals and communities to improve health. Facilitates community mobilization through community participation. Embraces promotion, prevention, protection. Influences the orientation of the health system toward health outcomes. Provides disease surveillance and control. Builds partnerships among sectors at the local level. Advocates for the health of the public. In addition to describing these contributions, the Issue Paper addresses the major trends in health services restructuring by providing an overview of the issues and outlining the Public Health response. While there is no one single model of restructuring occurring in the provinces and territories, many common themes exist. This paper highlights four categories of restructuring issues: I. Making a Difference in Health II. Skills and Knowledge Base III. Allocation of Financial Resources IV. Governance and Management.(ABSTRACT TRUNCATED AT 400 WORDS)

Canada↗

PubMed2001

Auditing nursing content in patient records.

The objective of this paper is twofold: (a) to explore different approaches in reviewing records based on a literature review of studies of audits of patient records and (b) to apply these approaches on a sample of records to illuminate consequences of their application. The method used was a literature review of papers on recording of nursing care (n = 56). Based on our findings, an audit of a stratified sample of records (n = 298) from Swedish community health care and nursing homes was performed, applying the different approaches for auditing previously described in the literature. The review showed that audits of patient records were performed using four different approaches with varying aims. The focus of the four approaches can be described as formal structure, process comprehensiveness, knowledge-based and concordance with actual care. The results of this study suggest that audits of patient records should not be solely limited to encompass the formal structure of recording. To avoid a superficial picture or a false sense of high quality and to obtain a more complete and reliable portrait of the quality of recording, we suggest the process comprehensiveness approach in combination with a critical review of the knowledge base for the assessment, diagnosis and interventions of patient records.

Medical Records↗

PubMed2000

Antibody modeling: implications for engineering and design.

Our understanding of the rules relating sequence to structure in antibodies has led to the development of accurate knowledge-based procedures for antibody modeling. Information gained from the analysis of antibody structures has been successfully exploited to engineer antibody-like molecules endowed with prescribed properties, such as increased stability or different specificity, many of which have a broad spectrum of applications both in therapy and in research. Here we describe a knowledge-based procedure for the prediction of the antibody-variable domains, based on the canonical structures method for the antigen-binding site, and discuss its expected accuracy and limitations. The rational design of antibody-based molecules is illustrated using as an example one of the most widely employed modifications of antibody structures: the humanization of animal-derived antibodies to reduce their immunogenicity for serotherapy in humans.

Antibodies↗

PubMed1994

Preventing occupational illness and injury: nurse practitioners as primary care providers.

Nurse practitioners with master's degrees were surveyed to assess the type and volume of occupational health services provided by primary care as compared with occupational health practitioners and the knowledge base in occupational health in these two groups. Thirty-six percent of 224 nonoccupational health nurse practitioners reported caseloads with 10% or more occupationally related chief complaints; 21% reported treating work-related injury or illness at least once per week. By contrast, a large percentage of nonoccupational health practitioners failed the knowledge-based exam. Large-scale prevention of occupational illness and injury warrants that primary care providers receive training in occupational health.

Accidents, Occupational↗

PubMed2002

Catapulting through life stages. When younger adults are diagnosed with life-threatening illnesses.

Knowledge of developmental stages through the life cycle has always been a hallmark of quality nursing care. The knowledge base gleaned from the older adult literature, such as Schachter-Shalomi and Miller's construct of sage-ing (1995), can help nurses understand that many of the completion tasks usually associated with aging suddenly are thrust to the forefront for younger adult patients diagnosed with a life-threatening illness. Using this knowledge base, nurses can facilitate developmental stage work facing younger adult patients whose illness catapults them into more mature stages for which they may have been unprepared. When younger adult patients are so diagnosed, nurses need to recognize the signs of catapulting life stage work and support it. It is no small task to complete the gestalt of one's life tapestry, but it is especially difficult when one is young.

Adult↗

PubMed2005

Depression in men with prostate cancer.

PURPOSE/OBJECTIVES: To summarize the current empirical knowledge base on depression in men with prostate cancer to inform psychosocial supportive care interventions for this population and chart directions for future research. DATA SOURCES: Reports in English of quantitative studies that included measures of depression or mood in samples of men with prostate cancer published from 1988-2004. DATA SYNTHESIS: Nurse researchers are playing a key role in establishing the scientific knowledge base upon which a better understanding of the relative importance of depression in men with prostate cancer will emerge. This review indicates that (a) predictable risk factors exist for depression among men with prostate cancer, (b) different prostate cancer treatments do not tend to be associated with differential outcomes in depression or mood, and (c) overall, men with prostate cancer report fewer depressive symptoms than women with breast cancer. CONCLUSIONS: The small body of research addressing depression in men with prostate cancer is methodologically inadequate to estimate the overall prevalence of depression among men with prostate cancer and determine the clinical significance of psychoeducational interventions targeting depression or mood in this population. IMPLICATIONS FOR NURSING: Nurses can use current knowledge to identify men with prostate cancer who are most at risk for depression. Evidence supporting the benefit of psychoeducational interventions for depression in other cancer populations (e.g., women with breast cancer) may be applicable to men with prostate cancer.

Depression↗

PubMed2004

Reliability and validity of the Stanford Presenteeism Scale.

OBJECTIVE: This study reports the reliability and validity of the 13-item Stanford Presenteeism Scale (SPS). The SPS differs from similar scales by focusing on knowledge-based and production-based workers. METHODS: Data were obtained from administrative and medical claims databases and from a survey that incorporated the SPS, SF-36, and the Work Limitations Questionnaire. RESULTS: Sixty-three percent (7797) of employees responded. Cronbach's alpha (0.83) indicates adequate reliability. Factor analysis identified two underlying factors, "completing work" and "avoiding distraction." Knowledge-based workers load on "completing work" (alpha = 0.97), whereas production-based workers load on "avoiding distraction" (alpha = 0.98). There were significant and positive relationships between the SPS, SF-36, and Work Limitations Questionnaire. CONCLUSIONS: The SPS demonstrates a high degree of reliability and validity and may be ideal for employers who seek a single scale to measure health-related productivity in a diverse employee population.

Absenteeism↗

PubMed1989

Nursing knowledge: women's knowledge. A sociological perspective.

As nurses approach the 21st century questions are being raised regarding the direction in which the profession is moving. The majority of leaders and educators in the field of nursing have, to this point, stressed the importance of defining nursing as a science and of developing a scientific knowledge base. Recently, however, there has been a move among some researchers and theorists in the field of nursing to question the ability of science and the scientific method to deal with nursing concerns. Using a variety of perspectives, including feminist theory, they are critiquing many of the basic assumptions about science, scientific method and scientific knowledge. This paper uses sociological and feminist theory to support the idea that nursing, as a discipline, has a distinct knowledge base which is not grounded in empirico-analytic science and its methodology but which stems from the lived experiences of nurses as women and as nurses involved in caring relationships with their clients.

Education, Nursing↗

PubMed1996

An automatic technique for finding and localizing externally attached markers in CT and MR volume images of the head.

An image processing technique is presented for finding and localizing the centroids of cylindrical markers externally attached to the human head in computed tomography (CT) and magnetic resonance (MR) image volumes. The centroids can be used as control points for image registration. The technique, which is fast, automatic, and knowledge-based, has two major steps. First, it searches the entire image volume to find one voxel inside each marker-like object. We call this voxel a "candidate" voxel, and we call the object a candidate marker. Second, it classifies the voxels in a region surrounding the candidate voxel as marker or nonmarker voxels using knowledge-based rules and calculates an intensity-weighted centroid for each true marker. We call this final centroid the "fiducial" point of the marker. The technique was developed on 42 scans of six patients-one CT and six MR scans per patient. There are four markers attached to each patient for a total of 168 marker images. For the CT images the false marker rate was zero. For MR the false marker rate was 1.4% (Two out of 144 markers). To evaluate the accuracy of the fiducial points, CT-MR registration was performed after correcting the MR images for geometrical distortion. The fiducial registration accuracy averaged 0.4 mm and was better than 0.6 mm for each of the eighteen image pairs.

Algorithms↗