Graphs: looking at relationships.
Research articles often incorporate data in the form of graphs. This article acts as a study guide to enable readers to understand and interpret the data produced in this way.
Audiovisual Aids↗
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Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
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[Evaluation of genetic test redundancy using a high-frequency component of the l-gram graph].
Various approaches to the estimation of DNA redundancy are compared: the Shannon entropy, the Lempel-Ziv complexity, and a new method, the computation of the low-frequency component of the l-gram graph. Although these methods are based on different ideas, they satisfy some reasonable requirements. The ability of these methods to find various kinds of repeats in genetic texts is compared. The resolution of the new method for calculation of DNA redundancy is discussed on the example of well-known repeats in the Epstein-Barr virus genome. The intrinsic discrepancy of high-frequency profile and Shannon redundancy profile were observed in some functionally significant regions of sequences being investigated.
Base Sequence↗
[On connection of a graph of a gene network with qualitative modes of function].
Theoretical investigation of properties of assumed gene networks constructed from elementary units of two types, genetic elements and control links, was carried out. A test was formulated for a subclass of such networks with cyclic structure called S(n,k)-networks allowing calculation-free prediction of the network limiting properties (the presence/absence and number of stationery and/or cyclic functioning modes) from a graph of the network structure. The obtained data can be useful for constructing gene networks with predefined properties.
Genetics↗
[An attempt to use graph theory for the description of demographic events].
"The possibility is discussed of using graphs to describe a sequence of demographic events such as births, marriages and deaths. Among all sequences of demographic events those with perturbations are singled out. The following perturbations are defined: childlessness, premature termination of childbearing caused by the death of the female or termination of marriage due to divorce or death of spouse, remarriage of females and pre-marital births." (SUMMARY IN ENG, RUS)
Demography↗
[Graph of sodium channel states].
Four models of sodium channel are considered, only one of its state being conducting. Transitions between any two communicated states are suggested to be governed by the first order kinetics. It is shown that the model describes current responses to single step potentials as well as inactivation -- activation coupling, if its graph has a function between the conducting and inactivation states and the state filled at the hyperpolarization.
Electrophysiology↗
[Application of power band graph method to the modeling and simulation of cardiovascular system].
This paper presents a computer simulation model of the cardiovascular circulation system, which describes the blood flow dynamic law in the cardiovascular system by the state equation. The model can be used in physiological study and computer-aided medical education. In this paper, the Power Band Graph (PBG) modeling method is used to realize modeling of the human circulation system and conduct a simulation study on a simplified physiological system model. The results demonstrate that the PBG method, as an understandable and unity modeling method, is quite effective and practicable and can be used widely in the field of physiological system simulation.
Computer Simulation↗
Molecular descriptor based on a molar refractivity partition using Randic-type graph-theoretical invariant.
PURPOSE: Development of a novel semi-empirical descriptor (MR(chi) for molecular modelling. METHOD: The index is based on a molar refractivity partition using Randictype graph-theoretical invariant. RESULTS: This hybrid index describes not only the London dispersive forces in a ligand fragment related to the molar refractivity but also structural features of the molecule It is also applicable in Quantitative Structure-Activity Relationship (QSAR) and Quantitative Structure-Property Relationship (QSPR) studies. CONCLUSIONS: The method is convenient and can discriminate between isomers.
Chemistry, Pharmaceutical↗
[Clinical application of a software for the analysis of arterial blood gases graph in 231 patients with chronic obstructive pulmonary disease].
OBJECTIVE: To evaluate the clinical significance of a computer software for the analysis of arterial blood gases graph (ABGG) in chronic obstructive pulmonary disease(COPD). METHODS: The software was developed with Win98 as the operating platform and the visual software Delphi 5.0 from Borland Company, and it was used for evaluation of the changes in arterial blood gases (ABG) of 231 COPD cases. RESULTS: (1) With the software it took only (4.7+/-0.5)s to draw and analyze an ABGG of COPD patients during oxygen inhalation; the time was much shorter than manual analysis (90.2+/-4.9)s, P<0.001. (2) During acute attack, the distributions of the arterial blood gases parameters on ABGG were as follows: 55.4% of cases in the area of insufficient ventilation and deranged gas exchange (area 5), 22.9% of cases in the area of compensated ventilation and deranged gas exchange (area 4), 21.6% of cases in the area of excessive ventilation and deranged gas exchange (area 6). (3) When the COPD patient's condition improved, the location of ABG in ABGG shifted from area 5 to area 4 or area 6. The distributions of the arterial blood gases parameters on ABGG of 106 cases on admission were significantly different from those at the time of discharge. (4) With deterioration of patient's condition, it shifted to area 5. Before death, the arterial blood gases parameters were exclusively in the area 5. CONCLUSION: The computer software for ABGG shortened the time to draw and evaluate ABG during oxygen inhalation, and it could reflect the changes in patient's condition promptly.
Aged↗
[Graphs on the growth of the ice-ball using round cryoprobes at -80 degrees C and -196 degrees C (author's transl)].
Graphs and tables are shown describing the growth especially the depth of the ice-ball in tissue during freezing with round flow and massive probes (2-20 mm diameter). Thus prior to clinical application of cryosurgery the probe diameter and the time of freezing can be estimated corresponding to the size of the tumor. Results are presented for temperatures of the cooling fluid of -196 degrees C (liquid nitrogen) and -80 degrees C.
Animals↗
Analysis of multiscale biochemical systems: graph methods.
The applicability of usual biochemical modelling by ordinary differential equations is restricted if some of the metabolite concentrations leave the range of observability during the time span of interest. Therefore, a method is needed for testing whether the solution of a differential equation system remains comparable with given reference concentrations, which depend on the conditions of measurement. In the present paper, such a method based on graph theory and non-standard analysis is developed for the special case of networks of monomolecular reactions endowed with linear kinetics.
Algorithms↗
Value of scatter-graphs for the assessment of ECG computer measurement results.
A new method is presented, different from usual methods, for the discussion of the results of computer ECG measurement programs, based on a new graphical evaluation method. The proposed "scatter-graphs" both highlight the main program results and facilitate the comparison between various wave-recognition algorithms. They allow the distinction between the reliability of an algorithm, which is its capacity to provide a maximum of measurements with a minimum amount of errors, and its precision, i.e., the standard deviation of the differences between its point estimates and the reference. The method proves to be a powerful tool for the discussion of individual, as well as the median program results in CSE Measurement Study. It allows to highlight limitations induced in performance assessment by the variability of the reference itself, and to state that the median program is at least as close to the "Gold Standard" as the median of the referees.
Algorithms↗
[Paths in graphs and selection of oligonucleotide linkers].
The problem of search of an universal linker with minimal length containing all restriction endonuclease recognition sites is considered. We reduce this problem to the search of Eiler's and Hamilton's paths in graph. The use of the discrete optimization methods allows to construct the linker with the length closed to the minimum.
Base Sequence↗
Use of labor graphs in a community hospital.
The large series reported by Friedman have established the importance of the time factor in relation to cervical dilatation and station of the presenting part during labor. Variations of the rate of dilatation and descent may be evident using a graph with the upper values of normal. This study was conducted in a Community hospital with an average of 200 deliveries a month. The attending physician followed labor as usual, unaware of the graphic recordings. The outcome of the labors with normal and abnormal graphic patterns were compared. There was a correlation between the abnormal labor pattern, arrest of cervical dilatation, with abdominal deliveries and lower apgar scores. The recognition of abnormal labors does not require a profound understanding of labor nor the range of normalcy.
Apgar Score↗
The use of graphs in the ergonomic evaluation of tall pilots' sitting posture.
A survey has shown that the average height of KLM pilots has increased by 18 mm (0.7 in) per decade in the last 20 years. Around 6% are taller than 1905 mm (75.0 in), the upper limit of pilot height for flight deck design. With the use of graphs of the flight deck, we established that the main problem of tall pilots is insufficient legroom. Of all KLM/NLM aircraft types, the Boeing 747-200/300 and the Douglas DC-9 are most uncomfortable for pilots taller than 1960 mm (77.2 in). In the Airbus A310, pilots of 2000 mm (78.7 in) have insufficient legroom. The other aircraft types do not present difficulties for pilots up to 2030 mm (79.9 in). Ergonomic adaptations on the flight decks of the Boeing 747-200/300 and the Airbus A310 are necessary to alleviate the problems of tall pilots. Future aircraft types should be designed to accommodate tall pilots. If ergonomic adaptation of the flight deck is impossible, anthropometric limits for pilot selection have to be employed.
Aerospace Medicine↗
Variations in the gait of normal children. A graph applicable to the documentation of abnormalities.
The goal of much orthopaedic treatment of children is to improve their walking. To document the quantitative characteristics of walking, we devised graphic displays of speed, cadence, stride length, and body height on the basis of 2,416 observations of 324 children walking over a range of speeds. The gait graph is an uncomplicated tool for the clinician to use in the documentation and evaluation of gait in children. It also provides the means to relate the walking abilities of patients to the standards for normal children.
Child↗
Application of graph theory for analysis of cell complexes observed in electron microscopy.
The present paper demonstrates analysis of cell contacts between various cell types of an organ using graph technique. The analysis permits to estimate random/non-random character of cell complexes of various types and is based on qualitative electronmicroscopical observations.
Animals↗
Application of graph theory to analysis of Langerhans cell types on the basis of their cell nuclei ultrastructure.
Studies were performed aimed at estimating similarities and differences in ultrastructure of Langerhans cells of albino mouse epidermis. Graph theory-based analysis of surface and circumference of nucleus cross-section, heterochromatin and interchromatin area permitted to advance a view that Langerhans cells constitute a uniform cell population, as far as morphology of cell nucleus is concerned.
Animals↗
The use of graph theory in analysis of cells and cell nuclei in particular.
Application of graph theory to morphological analysis of cells described by n parameters is presented. The analysis takes advantage of the possibility of describing structures in a multi-dimensional space. The method may be useful in determining similarity or differences between studied structures.
Cell Nucleus↗