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At least 145 records · Page 8Linked to original sources
PubMed2003

Windows to the ward: graphically oriented report forms. Presentation of complex, interrelated laboratory data for electrophoresis/immunofixation, cerebrospinal fluid, and urinary protein profiles.

BACKGROUND: Automated laboratory analyzers that mass produce data have been linked to information systems for more than two decades, but little progress has been made in developing more comprehensible report forms. Results are still reported in computer-generated printouts containing hundreds of numbers crowded into columns on each printed page. METHODS: We developed three software applications focusing on the graphic presentation of laboratory results. RESULTS: The first application summarizes data for a patient with a monoclonal gammopathy. The report provides a cumulative graphic presentation of immunofixation/electrophoresis data without any additional interpretation, focuses on a color-coded electrophoresis scan, and records up to 5 years on a single page. The second application deals with cerebrospinal fluid analysis. The report calculates relevant data and graphs the complex relationship between albumin and immunoglobulin results from paired serum and cerebrospinal fluid samples. Manually added interpretive text assures an output comprehensible to clinicians in all specialties. The third application produces a report summarizing quantitatively measured urinary marker protein profiles. The report form is generated by a flexible, completely user-definable knowledge-based system. It calculates numerous ratios and formulae, supports reflex testing, supplies an automated interpretation, and generates a specific graphic signature pattern of the results (MDI LabLink proteinuria differentiation). CONCLUSIONS: Increased clinical demand for graphically oriented report forms 5 years after their introduction has provided evidence that these reports transfer complex laboratory data and results to the clinician more effectively. The highest (more than threefold) increase in demand has been for reports for urinary marker protein profiles that feature a largely self-explanatory graphic signature pattern.

Autoanalysis↗
PubMed1996

A knowledge-based model construction approach to medical decision making.

We present a framework for representing the probabilistic effects of actions and contingent treatment plans. Our language has a well-defined declarative semantics and we have developed an implemented algorithm (named BNG) that generates Bayesian networks (BN) to compute the posterior probabilities of queries. In this paper we address the problem of projecting a contingent treatment plan by automatically constructing a structure of interrelated BNs, which we call a BN-graph, and applying the available propagation procedures on it. To address the optimal plan generation, we base our approach on the observation that normally the target plan space has a well-defined structure. We provide a language to describe plan spaces which resembles a programming language with loops and conditionals. We briefly present the procedures for finding the optimal plan(s) from such specified plan spaces.

Acute Disease↗
PubMed2002

A hypergraph-based method for unification of existing protein structure- and sequence-families.

Classification of proteins is a major challenge in bioinformatics. Here an approach is presented, that unifies different existing classifications of protein structures and sequences. Protein structural domains are represented as nodes in a hypergraph. Shared memberships in sequence families result in hyperedges in the graph. The presented method partitions the hypergraph into clusters of structural domains. Each computed cluster is based on a set of shared sequence family memberships. Thus, the clusters put existing protein sequence families into the context of structural family hierarchies. Conversely, structural domains are related to their sequence family memberships, which can be used to gain further knowledge about the respective structural families.

Databases, Protein↗
PubMed1993

Hierarchical functional organization of formal biological systems: a dynamical approach. III. The concept of non-locality leads to a field theory describing the dynamics at each level of organization of the (D-FBS) sub-system.

In paper I, the construction of the graph of interactions, called (O-FBS), was deduced from the 'self-association hypothesis'. In paper II, a criterion of evolution during development for the (O-FBS), which represents the topology of the biological system, was deduced from an optimum principle leading to specific dynamics. Experimental verification of the proposed extremum hypothesis is possible because precise knowledge of the dynamics is not necessary; only knowledge of the monotonic variation of the number of sinks is required for given initial conditions. Essentially, the properties of the (O-FBS) are based on the concept of non-symmetry of functional interactions, as shown by the 'orgatropy' function (paper II). In this paper, a field theory is proposed to describe the (D-FBS), i.e. the physiological processes expressed by functional interactions: (i) physiological processes are conceived as the transport of a field variable submitted to the action of a field operator; (ii) because of hierarchy, this field theory is based on the concept of non-locality, and includes a non-local and non-symmetric interaction operator; (iii) the geometry of the structure contributes to the dynamics via the densities of structural units; and (iv) because a physiological process evolves on a particular timescale, it is possible to classify the levels of organization according to distinct timescales, and, therefore, to obtain a 'decoupling' of dynamics at each level. Thus, a property of structurality for a biological system is proposed, which is based on the finiteness of the velocity of the interaction, thus, with distinct values of timescales for the construction of the hierarchy of the system. Three axioms are introduced to define the fields associated with the topology of the system: (i) the existence of the fields; (ii) the decoupling of the dynamics; and (iii) the ability of activation-inhibition. This formulation leads to a self-coherent definition of auto-organization: an FBS is self-organized if it goes from one stable state for the (D-FBS) to another under the influence of certain modifications of its topology, i.e. a modification of the (O-FBS). It is shown that properties deduced with this formalism give the relationship between topology and geometry in an FBS, and particularly, the geometrical re-distribution of units.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1979

[Activation of student cognitive activities in the process of teaching medical microbiology].

The main trends of methodical work conducted at the chair of microbiology of Orenburng Medical Institute are presented. For the purpose of activation of cognition activity of students during medical microbiology teaching the following methods were applied: presentation of the teaching material, creation of visual teaching methods in a single methodical plan in accordance with the logic structure graphs of the subject as a whole, its individual sections and themes; introduction of problem teaching method, solution of practical tasks of the II and III learning level; introduction of scientific achievements of the chair into the teaching process. Result of evaluation of the efficacy of the teaching-methodical work of the chair carried out demonstrated that knowledge of the principal microbiology problems in the students and interns persisted for long periods of time.

Cognition↗
PubMed1982

An approach to completely automatic comparison of two-dimensional electrophoresis gels.

The problem addressed is that of determining the similarities and differences appearing in a sequence of two-dimensional polyacrylamide gels where we have no a priori knowledge of the intensity and spatial distribution of the protein spots. It is assumed that the gels are not in precise registration. An attempt is being made to develop a completely automatic program for use in genetic studies, which will compare a sequence of three gels run on samples from father, mother, and child. The program constructs a graph by using as nodes those spot cues that exceed a given intensity threshold. The graphs are then compared to determine an initial subset of spots that are common to all three gels. From this subset of common spots the program then determines whether the remaining graph differences are real or result from quantitative variation causing spots to fall below threshold.

Adult↗
PubMedDate not supplied

[Pressure distribution on the sole of the human foot while standing and walking, barefoot and with shoes].

For more than a century, scientists and practicians of orthopedic shoe production have been increasing their knowledge on the normal statics and dynamics of the lower extremities as well as on innate or often acquired posture anomalies and foot deformities. Even amongst young adults, barely half of one percent has so-called "inconspicuous" feet without restrictive signs of foot deformities. Consequently, the resulting primary illnesses and secondary injuries must be treated. Quantitative pressure distribution graphs in isobaric representation at the heel barefoot when standing and walking were determined by means of an improved, locally fixed device by Elftman and Helm. For the first time, a newly developed mobile measuring process allows measuring pressures at the heel inside the shoe while standing as well as while walking, running or jumping. The rolloff motion of the heel allowed the determination of a "maximum pressure line." Orthopedic recommendations for the production of true-to-form and true-to-function shoes for walking and sports shoes are included.

Biomechanical Phenomena↗
PubMed2000

Likelihood analysis of phylogenetic networks using directed graphical models.

A method for computing the likelihood of a set of sequences assuming a phylogenetic network as an evolutionary hypothesis is presented. The approach applies directed graphical models to sequence evolution on networks and is a natural generalization of earlier work by Felsenstein on evolutionary trees, including it as a special case. The likelihood computation involves several steps. First, the phylogenetic network is rooted to form a directed acyclic graph (DAG). Then, applying standard models for nucleotide/amino acid substitution, the DAG is converted into a Bayesian network from which the joint probability distribution involving all nodes of the network can be directly read. The joint probability is explicitly dependent on branch lengths and on recombination parameters (prior probability of a parent sequence). The likelihood of the data assuming no knowledge of hidden nodes is obtained by marginalization, i.e., by summing over all combinations of unknown states. As the number of terms increases exponentially with the number of hidden nodes, a Markov chain Monte Carlo procedure (Gibbs sampling) is used to accurately approximate the likelihood by summing over the most important states only. Investigating a human T-cell lymphotropic virus (HTLV) data set and optimizing both branch lengths and recombination parameters, we find that the likelihood of a corresponding phylogenetic network outperforms a set of competing evolutionary trees. In general, except for the case of a tree, the likelihood of a network will be dependent on the choice of the root, even if a reversible model of substitution is applied. Thus, the method also provides a way in which to root a phylogenetic network by choosing a node that produces a most likely network.

Computer Graphics↗
PubMed1990

[Mortality analysis: when is single evaluation of the basic cause of death allowable, when should multi-causality be assessed?].

Data quality is often a critical point in mortality studies. The purpose of the present report is to present criteria for assessing the value of death-certificate-based mortality studies. For this purpose all 57,454 Swiss death certificates of the year 1979 were analysed. Reliability of the diagnosis listed on the death certificate was investigated by comparing for each case of a linked sample of 12,478 deaths the cause of death with medical information available from the hospital record. Retrieval rates (percentage of cases for which the given diagnosis appears in both registries) were calculated for the primary diagnoses named in each data set. These can be considered as measures of reliability of diagnoses. The graphs given indicate a high reliability for cancers and accidents. Reliability was lower for other causes of death such as cardiovascular diseases, diabetes mellitus, rheumatic diseases. Restriction to the primary cause of death can be accepted for most cancers, accidents and violent deaths. For other causes of death, decisions must be made individually and multicausal analysis may be indicated. In addition, knowledge of the reliability of the diagnoses of interest is necessary for the interpretation of results derived from death certificate-based mortality studies.

Cause of Death↗
PubMed1994

Internal temperature calibration for 1H NMR spectroscopy studies of blood plasma and other biofluids.

A method for temperature calibration of human blood plasma and cerebrospinal fluid (CSF) samples inside a high resolution NMR spectrometer is presented. This calibration is based on the temperature dependence of the chemical shift difference between the water signal and that from the H-1 proton of endogenous alpha-glucose or, in some circumstances, beta-glucose. This dependence can be fitted using a second-order polynomial equation and functions for both human blood plasma and human CSF are given. Similar graphs could easily be generated for other fluids. The blood plasma calibration appears to be accurate to +/- 0.9 K in test samples. The use of the blood plasma calibration graph has also been evaluated using the 1H NMR spectra of CSF and shown to overestimate the CSF internal temperature by ca 1.3 K. This approach should have a general applicability to blood plasma and CSF samples from normal and pathological situations or from other species, because there are unlikely to be large changes in ionic strength or pH even in disease states. Knowledge of the exact internal temperature of plasma samples is likely to be of particular importance in the investigation of lipid and lipoprotein interactions because of the significant temperature dependence of lipid and lipoprotein NMR linewidths in such samples.

Body Fluids↗
PubMed2026

Genomic insights into natural selection in recent human history.

For over a century, scientists have debated the extent to which genetic and phenotypic variation among present-day humans is the result of natural selection - in which heritable traits influence survival or reproduction - versus neutral processes such as genetic drift or population history. The initial sequencing of the human genome and subsequent population resequencing studies enabled genome-scale searches for signatures of selection in present-day genomes. This first generation of genome-wide selection scans identified many targets but left open questions about the timing and nature of selection, making it challenging to identify environmental and biological drivers. Recent methodological advances based on reconstructing ancestral recombination graphs have increased the potential power and resolution of selection scans based on present-day genomes, while the availability of new data on ancient DNA has facilitated the direct reconstruction of genetic change through time. However, there is little consensus on how to use these data to detect and interpret signatures of selection, while avoiding confounders. Here, we review the current state of knowledge about the impact of selection on human genomic diversity and highlight conceptual advances in our understanding of human evolution over the past 10,000 years.

Journal Article↗
PubMed2002

Co-clustering of biological networks and gene expression data.

MOTIVATION: Large scale gene expression data are often analysed by clustering genes based on gene expression data alone, though a priori knowledge in the form of biological networks is available. The use of this additional information promises to improve exploratory analysis considerably. RESULTS: We propose constructing a distance function which combines information from expression data and biological networks. Based on this function, we compute a joint clustering of genes and vertices of the network. This general approach is elaborated for metabolic networks. We define a graph distance function on such networks and combine it with a correlation-based distance function for gene expression measurements. A hierarchical clustering and an associated statistical measure is computed to arrive at a reasonable number of clusters. Our method is validated using expression data of the yeast diauxic shift. The resulting clusters are easily interpretable in terms of the biochemical network and the gene expression data and suggest that our method is able to automatically identify processes that are relevant under the measured conditions.

Algorithms↗
PubMed1996

Knowledge on collection and analysis of health information of state certified nurses from rural health centres, Masvingo Province.

OBJECTIVE: To assess the knowledge on collection and analysis of health information of State Certified Nurses (SCNs) from Rural Health Centres (RHCs), Masvingo Province. DESIGN: Three methods were employed during the assessment: a questionnaire, observation, and practical exercises (calculations). SETTINGS: 19 RHCs in Chiredzi and Bikita Districts, Masvingo Province. SUBJECTS: 19 SCNs in charge of Rural Health Centres. MAIN OUTCOME MEASURES: Ability to analyze and utilize health information, availability of graphs, master cards summaries (health diaries) and minutes. Presence or absence of catchment maps, charts on population breakdown and immunization coverage charts. Ability to calculate some rates and percentages. RESULTS: Of 19 SCNs in charge who said they do school health programmes, only six had any evidence that they do so; of nine SCNs in charge who reported that they have graphs on weekly reported diseases, only four had graphs displayed. Of 18 SCNs in charge who said they had immunization coverage targets only 11 had charts displayed; of 18 SCNs in charge who reported that they discuss health problems in their areas, only one had minutes documenting the discussion. Only six of 19 SCNs at rural centres could calculate coverage rates and only one of 19 SCNs at health centres could calculate dropout rates. CONCLUSION: Comparing the questionnaire responses with the findings from observations, it can be seen that more is reported than is actually done. From the practical exercises it was evident that the ability to do basic calculations was often lacking.

Data Collection↗
PubMed1976

Lateralization in stroke syndromes as a factor in ambulation.

Lateralization should not be ignored in any rehabilitation program for patients with stroke syndromes. Despite the known differences resulting from the localization in the dominant versus the nondominant hemisphere (spatial perception, speech, etc.), practical application of this knowledge in gait training is sparse. The authors looked into different stages of ambulation and the time sequence between these stages and the onset of disease. Standing and walking in parallel bars and outside, as well as elevation activities were given numerical values in an effort to assess abilities quantitatively. The assessment of each patient was recorded graphically (stage of gait against time) and then the different graphs were summated in order to form a common right hemiparetic versus left hemiparetic curve. This study of 236 out of 298 patients (129 left hemiparetics and 107 right ones) showed the following: (1) The right hemiparetics progressed more rapidly in all stages of ambulation, statistically significant figures being obtained for the first two stages; (2) a greater percentage of right versus left hemiparetics reached the assigned levels of ambulation: and (3) 89% out of the 236 patients included in our study were able to ambulate in parallel bars, 81% outside the bars and 38.5% were proficient in stair climbing. Out of the original total number of patients (298), 64% were able able to ambulate outside the bars.

Adolescent↗
PubMed2001

Evaluation of dental radiographic identification: an experimental study.

The object of this study was to assess the value of dental radiographs for the purposes of personal identification in the absence of tooth restorations. 198 periapical and bitewing radio graphs were taken of teeth contained in 22 dry skulls obtained from the skull collection of the Royal College of Surgeons of Edinburgh. Each selected view was taken three times: by a scientist, a dentist and a dental radiographer. Each operator independently positioned the films, selected the exposure times and positioned the cone of the X-ray machine. Three groups comprising forensic odontologists, dental vocational trainees and dental trainee hygienists attempted to match the randomly mixed radiographs into sets of three. Success rates for matching radio graphs ranged from 63.6 to 100%. The average for forensic odontologists was 93.3%, vocational trainees 85.2% and hygienists 89.7%. Where forensic odontologists had both formal training and experience, or extensive experience without formal training, the success rate was 100%. Where there was formal training but little experience the success rate was lower. Participants believed that root morphology and alignment had been the greatest aid to matching and not crown morphology. The depth of knowledge of the viewer correlated poorly with the number of correct results, although the forensic odontologists achieved the highest success rate. Formal training, although highly desirable, is no substitute for practical experience. Root morphology and alignment were cited most frequently as facilitating matching.

Clinical Competence↗
PubMed1999

Quality through metrics.

The Quality Assurance Unit analyzed 18 months of departmental data regarding the report-audit cycle. Process mapping was utilized to identify milestones in the cycle for measurement. Five milestones were identified in the audit cycle, as follows: (1) time from report receipt in quality assurance to start of audit, (2) total calendar days to audit a report, (3) actual person-hours to perform a report audit, (4) time from completion of audit to issuance of report, and (5) total time a report is in quality assurance. An interrelationship diagraph is a quality tool that is used to identify what activities impact the overall report-auditing process. Once the data collection procedure is defined, a spreadsheet is constructed that captures the data. The resulting information is presented in time charts and bar graphs to visually aid in interpretation and analysis. Using these quality tools and statistical analyses, the Quality Assurance Unit identified areas needing improvement and confirmed or dispelled previous assumptions regarding the report-auditing process. By mapping, measuring, analyzing, and displaying the data, the overall process was examined critically. This resulted in the identification of areas needing improvement and a greater understanding of the report-audit cycle. A further benefit from our increased knowledge was the ability to explain our findings objectively to our client groups. This sharing of information gave impetus to our clients to examine their report-generation process and to make improvements.

Data Collection↗
PubMed1996

Should Common Optimal Movement Patterns Be Identified as the Criterion to Be Achieved?

Recently, a new paradigm has been proposed for the study of knowledge of performance (Schmidt & Young, 1991). In this paradigm, the experimenters identified an optimal kinematic movement pattern, based on the performance of a best subject, which was imposed on all subjects as the criterion to achieve. This approach, which assumes that this pattern is the best way for all subjects to do the task, was tested in the present experiment. In Experiment 1, a common optimal movement pattern could not be identified by an analysis of scatterplot graphs of the scores plotted as a function of various kinematic vanables or by correlating (within and across subjects [N = 14]) each kinematic variable with the score. In Experiment 2, subjects (N = 12) were retrained in 2 separate sessions, during which they tried to reproduce either a personal best or the best subject's template. Results indicated that scores were similar regardless of the template pattern being used. During training, however, subjects who used their personal template had a lower incidence of zero scores and were more consistent than those who used the template of the best subject. This provided a second line of evidence against the assumption that a common optimal movement pattern exists for this type of task.

Journal Article↗
PubMed1991

A laser densitometer for selective spot analysis on dot blots and two-dimensional gel autoradiograms.

We describe an inexpensive densitometer, employing a small HeNe laser and an IBM-compatible personal computer that performs accurate measurements of selected spots on two-dimensional gel autoradiograms or chromatograms with an accuracy and a sensitivity equal or superior to those of many commercial instruments. Our open-table design allows the operator to visually monitor the scanning process in room lighting, and provides great flexibility in both the size and the nature of items to be scanned. The instrument has two moving parts (a prism and a small motor). A commercially available software package (ASYST) acquires digital data, graphs the data on the TV monitor, converts the data to optical density or to radioactive incorporation (cpm), subtracts background, integrates peak areas, and stores data on disk. The total time for these operations is 20-30 s per spot. The instrument has a dynamic range of 0.25 to 3.0 OD units and can measure a 10,000-fold range of 14C or 35S isotope concentrations on autoradiograms. The complete device can be assembled with a hobbyist's knowledge of electronics, moderate programming abilities (no machine language required), and a cost of less than $3000, not including the IBM PC.

Costs and Cost Analysis↗