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PubMed2002

Graphing calculators and students' conceptions of the derivative.

This study compared the effect of using graphing calculators on college students' conceptual understanding of the derivative with the traditional teaching approach in Calculus I course. Students (49 men and 52 women) in four classes at a large public university participated. On a posttest, women who were taught calculus using the graphing calculator had significantly higher scores than those taught by the traditional method.

Adolescent↗

PubMedDate not supplied

A learning tool in medical imaging: using procedure graphs in radiographic process simulation.

Teaching the procedural elements of imaging protocols and understanding the interrelationships and interdependencies of diagnostic X-ray system parameters and their effects on image quality, are among the main objectives of medical imaging training programs. A teaching tool is designed and implemented to support these goals. Tool design is influenced by hybrid learning system architectures and it is based on a graph approach, which is described. Implementation is carried out using a hypermedia development environment (Toolbook) coupled with a database (Paradox). The core of the system is an attributed priority graph, capable of supporting the organization of the domain knowledge, monitoring of user-machine interaction and managing the user-system dialogue. Use of this approach resulted in an interactive simulation tool, which provides computer aided learning support, to radiology related personnel, such as radiologists and radiographers. The potential value of the tool is not restricted only to didactic tasks, but may include trouble-shooting and documentation.

Computer Simulation↗

PubMed1999

Identification of structural domains in proteins by a graph heuristic.

A novel automatic procedure for identifying domains from protein atomic coordinates is presented. The procedure, termed STRUDL (STRUctural Domain Limits), does not take into account information on secondary structures and handles any number of domains made up of contiguous or non-contiguous chain segments. The core algorithm uses the Kernighan-Lin graph heuristic to partition the protein into residue sets which display minimum interactions between them. These interactions are deduced from the weighted Voronoi diagram. The generated partitions are accepted or rejected on the basis of optimized criteria, representing basic expected physical properties of structural domains. The graph heuristic approach is shown to be very effective, it approximates closely the exact solution provided by a branch and bound algorithm for a number of test proteins. In addition, the overall performance of STRUDL is assessed on a set of 787 representative proteins from the Protein Data Bank by comparison to domain definitions in the CATH protein classification. The domains assigned by STRUDL agree with the CATH assignments in at least 81% of the tested proteins. This result is comparable to that obtained previously using PUU (Holm and Sander, Proteins 1994;9:256-268), the only other available algorithm designed to identify domains with any number of non-contiguous chain segments. A detailed discussion of the structures for which our assignments differ from those in CATH brings to light some clear inconsistencies between the concept of structural domains based on minimizing inter-domain interactions and that of delimiting structural motifs that represent acceptable folding topologies or architectures. Considering both concepts as complementary and combining them in a layered approach might be the way forward.

Evaluation Studies as Topic↗

PubMed1992

Representation of clinical data using SNOMED III and conceptual graphs.

None of the coding schemes currently contained within the Unified Medical Language System (UMLS) is sufficiently expressive to represent medical progress notes adequately. Some coding schemes suffer from domain incompleteness, others suffer from the inability to represent modifiers and time references, and some suffer from both problems. The recently released version of the Systematized Nomenclature of Medicine (SNOMED III) is a potential solution to the data-representation problem because it is relatively domain complete, and because it uses a generative coding scheme that will allow the construction of codes that contain modifiers and time references. SNOMED III does have an important weakness, however. SNOMED III lacks a formalized system for using its codes; thus, it fails to ensure consistency in its use across different institutions. Application of conceptual-graph formalisms to SNOMED III can ensure such consistency of use. Conceptual-graph formalisms will also allow mapping of the resulting SNOMED III codes onto relational data models and onto other formal systems, such as first-order predicate calculus.

Medical Informatics Applications↗

PubMed1991

Psychotropic medication efficacy graphs: an application of applied behavior analysis.

Boswell Center Psychotropic Medication Efficacy Graphs were developed to monitor the longitudinal effects of psychotropic medication on individuals with mental retardation. Levels of maladaptive and prosocial behaviors, medication side-effects, and psychotropic medication were considered simultaneously via the graphing system. The system provides data-based feedback to prescribing physicians and reduces reliance on anecdotal recollections.

Data Collection↗

PubMed1991

Nutrition labels in bar graph format deemed most useful for consumer purchase decisions using adaptive conjoint analysis.

This study estimated the effects of changing multiple levels and combinations of nutrition information format, load, expression, and order on consumers' perceptions of label usefulness in purchase decisions using adaptive conjoint analysis. A shopping mall intercept survey, which was administered by a marketing research firm, assessed consumer preferences for 12 label alternatives produced on Campbell's soup cans to portray nutrition information realistically; 252 of 258 respondents completed the computer interactive interview. Consumers significantly preferred the bar graph format to the bar graph/nutrient density and traditional label formats. Consumers considered the bar graph/nutrient density format to be as useful as the traditional label format. There was a highly significant difference among the three levels of information load; the most information load was preferred regardless of nutrient importance. Consumers significantly preferred nutrition information stated in absolute numbers and percentages vs in absolute numbers only in traditional, or in percentages only expressions. There was a significant difference between consumer preferences for the two types of information order. The findings indicate that consumers clearly preferred the nutrition label that displayed all nutrient values using a bar graph format, offered the most information load, and expressed nutrient values using both absolute numbers and percentages. Consumers also preferred nutrition information rearranged in an order that grouped nutrients that should be consumed in adequate amounts on the top, calories in the middle, and nutrients that should be consumed in lesser amounts on the bottom of the label.

Consumer Behavior↗

PubMed1990

[An assessment of the acceptance of a face graph as a health education device].

With the aging of society, an increasingly greater number of people receive health evaluations organized by the community. Results of health evaluations are usually obtained as multiphasic numerical figures which are usually written down directly into a prescribed results form by which the community health personnel inform examinees of their health status. Most of aged examinee, however, cannot fully comprehend their own health status expressed as multiphasic numerical figures. Community health personnel also have difficulty in explaining these numerical results. Although the cartoon of face has been shown to be an effective device to help understand multiphasic numerical values, its use is not yet popular among community health personnel. The use of a face graph as an aid for health information and education activities by community health personnel was studied using a simple face drawing system developed for lap-top microcomputers. In this study, the acceptability of this face was evaluated by 29 community health nursing students and 31 community health nurses, studying and/or working in Nagasaki Prefecture, Japan. The first evaluation was made of a newly developed prescribed health evaluation result form using a face graph (facial form). All subjects evaluated the acceptability of this facial form by comparing it to the usual numerical form on the basis of the following five items: (1) discrimination of abnormal range, (2) evaluation of the degree of abnormality, (3) discrimination of normal range, (4) provocation of interest in one's own health status, and (5) stimulation of familiarity in one's own health status.(ABSTRACT TRUNCATED AT 250 WORDS)

Community Health Nursing↗

PubMed1990

Program for drawing bar graphs on IBM Personal computers.

A simple program for drawing Bar graphs on IBM Personal computers is described here. This program is written in BASIC language and is user friendly. The program allows the operator to plot the bars with standard error, adjust the spacing between the bars and save the 'bar in a floppy disk. Legend can also be added at appropriate places in the graph. In the graphic mode, a hard copy can be obtained from a dot matrix printer using print screen command.

Computer Graphics↗

PubMed1985

Graph theoretical approach to structure-activity studies: search for optimal antitumor compounds.

An approach based on graph theoretical methods for searching the most potent drug among numerous candidate structures is outlined. First, we identify the strategic fragment and describe it by suitable graph theoretical invariants. We have adopted path numbers derived from suitably weighted bonds as basic invariants. Similarity among structures is quantitatively derived from similarity and differences in atomic path numbers for the strategic fragment. The approach is illustrated on a selection of antitumor phenyldialkyltriazenes for which log(1/C) are known. By starting the search with an unsubstituted parent compound, in few steps we located 1-(4-NHCOCH3-Phenyl)-3,3-dialkyltriazene as the most potent drug among those considered.

Antineoplastic Agents↗

PubMed1980

[Compensation graph method of group representation of statistically processed results of an acid-base equilibrium investigation in cattle].

A graphic method was worked out for representing the statistical processed results of the determination of blood pH, pCO2, and base excess in a group of animals subjected to a metabolic test. The method is based on the determination of a selective mean and 95% confidence interval of the selective mean of the above-mentioned parameters in a group of animals; these mean values and confidence intervals are then plotted in a compensation graph. The area delimited in the graph by the upper and lower limits of the 95% confidence intervals of the selective means includes the mean values of the basic population with the probability of 94.7375%. The position of the plotted individual acid-base balance values of 422 animals, compared with the 60 areas delimited by the 95% confidence intervals of the selective means for the groups of animals, showed a very good correspondence in 91.23% of cases and partial correspondence in 8.74% of cases.

Acid-Base Equilibrium↗

PubMed1982

[About the body length frequency of 19.5 year old men after the graph of Harbeck (1960) (author's transl)].

Based on the Harbeck-graph of body length frequency for 19.5 years old men (1960), 2 methods are exercised for determining the Gaussian distribution function. At first the area arising from the frequency of length classes with the abscissa of its gravity center and the dispersion or variance are egalized to the respective values for the Gaussian curve. After that nonlinear regressions following the Paul-method (1975) are carried out minimizing the sums of the squares, absolute values and square roots of the deviations. The results of the conventional method could be improved numerically but were not discernible in graphs. Finally the subdivision into growth groups is taken into consideration.

Adult↗

PubMed1981

[Logical structure graphs in the teaching of oncology].

The graduates of medical institutes are the first link in the general therapy network, where all patients with pretumor and tumor lesions are referred to for medical aid. It is the rate of their training in oncology that the number of patients with advanced malignancies depends on. To improve the teaching of oncology the writers have used the graphs of logical system, which enabled not only the student but also the teacher to concentrate their attention on the key, basic problems, to choose the necessary information and to reject an excessive secondary one. The graphs of logic system allow the student to realize and understand the structure of the subject concerned, as a whole, the relationship of separate elements under study, thus being a visual aid contributing to better mastering the subject. The former offer good grounds for a scientific approach to the teaching problems.

Logic↗

PubMed1995

Automated coding of patient discharge summaries using conceptual graphs.

In medicine, as in other domains, indexing and classification is a natural human task which is used for information retrieval and representation. In the medical field, encoding of patient discharge summaries is still a manual time-consuming task. This paper describes an automated coding system of patient discharge summaries from the field of coronary diseases into the ICD-9-CM classification. The system is developed in the context of the European AIM MENELAS project, a natural-language understanding system which uses the conceptual-graph formalism. Indexing is performed by using a two-step processing scheme; a first recognition stage is implemented by a matching procedure and a secondary selection stage is made according to the coding priorities. We show the general features of the necessary translation of the classification terms in the conceptual-graph model, and for the coding rules compliance. An advantage of the system is to provide an objective evaluation and assessment procedure for natural-language understanding.

Artificial Intelligence↗

PubMedDate not supplied

LUF-syndrome biological diagnosis by basal body temperature (BBT) graph.

73 consecutive patients were monitored and submitted to ambulatorial screening for primary infertility. In all of them was also performed a study of the BBT behaviour and the results reported on a graph. All these with LUF syndrome had substantial deviation of the BBT graphs. This observation can make us obtain a new parameter and a first diagnostic approach in the study of the ovulatory infertility.

Basal Metabolism↗

PubMed1993

Use of a rule based graph-theoretical system in evaluating the activity of a class of nucleoside analogues against human immunodeficiency virus.

A rule based graph-theoretical system has been used to evaluate qualitatively the activity of a class of nucleoside analogues against human immunodeficiency virus (HIV). The system identifies biologically relevant vertices (atoms) in the molecular graphs of the compounds which have the biological activity of interest. The idea is to relate biological activity with the structural or substructural characteristics of the compounds from the point of view of molecular topology (connectivity). The system brings vertices of similar or close topological environment in the respective compounds together and this is reflected in the ranges of values formed by a distance based index of the vertices, the 'distance exponent index (Dx)', where x is any real number. It is found that the system makes correct prediction of the activity of all the compounds (active as well as inactives) of both training set and the test set against HIV. It is also apparent from this study that the index D-4, which has been used here, can make a useful classification of the vertices according to their molecular environment and the system can produce significant result in a small as well as diverse data base.

Antiviral Agents↗

PubMed1996

Descent graphs in pedigree analysis: applications to haplotyping, location scores, and marker-sharing statistics.

The introduction of stochastic methods in pedigree analysis has enabled geneticists to tackle computations intractable by standard deterministic methods. Until now these stochastic techniques have worked by running a Markov chain on the set of genetic descent states of a pedigree. Each descent state specifies the paths of gene flow in the pedigree and the founder alleles dropped down each path. The current paper follows up on a suggestion by Elizabeth Thompson that genetic descent graphs offer a more appropriate space for executing a Markov chain. A descent graph specifies the paths of gene flow but not the particular founder alleles traveling down the paths. This paper explores algorithms for implementing Thompson's suggestion for codominant markers in the context of automatic haplotyping, estimating location scores, and computing gene-clustering statistics for robust linkage analysis. Realistic numerical examples demonstrate the feasibility of the algorithms.

Alleles↗

PubMed1996

A graph-grammar approach to represent causal, temporal and other contexts in an oncological patient record.

The data of a patient undergoing complex diagnostic and therapeutic procedures do not only form a simple chronology of events, but are closely related in many ways. Such data contexts include causal or temporal relationships, they express inconsistencies and revision processes, or describe patient-specific heuristics. The knowledge of data contexts supports the retrospective understanding of the medical decision-making process and is a valuable base for further treatment. Conventional data models usually neglect the problem of context knowledge, or simply use free text which is not processed by the program. In connection with the development of the knowledge-based system THEMPO (Therapy Management in Pediatric Oncology), which supports therapy and monitoring in pediatric oncology, a graph-grammar approach has been used to design and implement a graph-oriented patient model which allows the representation of non-trivial (causal, temporal, etc.) clinical contexts. For context acquisition a mouse-based tool has been developed allowing the physician to specify contexts in a comfortable graphical manner. Furthermore, the retrieval of contexts is realized with graphical tools as well.

Adverse Drug Reaction Reporting Systems↗

PubMed1996

Application of attributed graphs in diagnostic pathology.

OBJECTIVE: To compute attributed graphs based upon calculation of the minimum spanning tree (MST) for various applications in diagnostic lung pathology. STUDY DESIGN: The study design included assistance in histologic diagnosis, confirmation of the diagnosis in single cases, measurement of texture alterations after induction chemotherapy, estimation of prognosis of operated-on lung cancer patients and analysis of lung cancer cells in association with differentiation markers. The histologic slides were Feulgen stained, and features of the integrated optical density (IOD) were associated with the nodes of the MST. The same procedure was applied to immunohistochemically and ligand histochemically stained slides by calculation of the mean staining intensity of the cytoplasm of tumor cells. A measure for structural entropy was introduced by computing the relative differences in distance and IOD between neighboring tumor cells in a 1/r2 field of force. In addition, the current of entropy was computed. RESULTS: Structural entropy reflects alterations in regular textures; the current of entropy is an especially good prognostic parameter in lung cancer. In immunochemistry and ligand histochemistry, construction of the attributed MST permits detailed insight into locally different staining behavior of tumor cells and immunocompetent cells. CONCLUSION: Attributed graphs contain important information that can be used for the estimation of survival or for confirmation of diagnostic entities, such as tumor cell types.

Adolescent↗