Quantitative Computer Analysis Research Articles

Quantitative computer analysis of Golgi-impregnated neurons using a new ‘expanded stick’ model for coding; its application to the study of axons

A computer program to obtain quantitative data from an expanded ‘stick model’ of the Golgi-impregnated neuron is described. The computer program allows complete three-dimensional morphometric analysis of neurons, including the size of varicosities and spines and their distribution on neuronal branches. Furthermore, the perimeter and area of the perikaryon as well as the length, width and area of neuronal processes can be obtained. The use of this computer program is illustrated by coding two types of axons.

Elsie 4: Quantitative computer analysis of sets of two-dimensional gel electrophoretograms

We have developed and refined a system for quantitative computer analysis of two-dimensional polyacrylamide gel electrophoretograms. The system, named Elsie 4, is based on one described by Vo et al. ( Anal. Biochem. 112, 258 (1981)) . It is highly automated. Elsie 4 can find, and measure the intensity of, almost any spot resolvable on two-dimensional gels, including spots visible only as shoulders off larger spots and spots so close together that there is no “valley” between them. It can automatically match the spot patterns of different gels, potentially without the need for a user to provide landmark matches. The matches between paired gels let us follow the synthesis of any spot through a set of gels. Information about a group of matched spots can be obtained by referring to any spot in the group. There is generally no need for a standard or reference gel. Data for two experiments can be combined and compared by matching any gel in one experiment with any gel in the other. There are ways to automatically find possible mismatches in sets of gels. Scans and the results of the analysis can be shown on an image displayer. The programs use function libraries; this helps ensure consistency and increase portability. The programs and functions can be linked together in many ways; this lets users build custom programs for analysis of specific experiments.

Genetic polymorphism of a lymphocyte protein (p75) with six different alleles studied by two-dimensional electrophoresis: qualitative and quantitative data.

The genetic polymorphism of a human lymphocyte protein (p75) was studied by two-dimensional electrophoresis within 17 families and, in addition, 22 unrelated individuals from Southern Germany, resulting in a total of approximately 100 individuals. The cytosolic and membrane proteins from cell lysates of phytohemagglutinin stimulated and [3H]leucine labeled lymphocytes were separated by two-dimensional electrophoresis. The p75 protein with an approximate molecular weight of 75,000 occurred in six variants with slightly different isoelectric points and/or apparent molecular weights. Three common variants (a, b, and c) and three rare variants (d, e and f) could be distinguished. Among the approximately 100 individuals studied we observed 15 different phenotypes, three homozygous (p75-a, -b, -c) and 12 heterozygous (p75-ab, -ac, -bc, -ad, -ae, -be, -bf, -cd, -ce, -cf, -de, -df) phenotypes. The genetics of the p75 protein variations was ascertained by family studies and quantitative computer analysis. We were able to show a Mendelian mode of inheritance of the variants within the families and a gene-dosage dependence of the protein spots in homozygous and heterozygous phenotypes. The data allowed us to assume a polymorphic protein p75 determined by six alleles on a autosomal gene locus. The allele frequencies were calculated from the phenotype distribution within 56 unrelated individuals. The gene frequencies of the three common alleles ranged between 0.38 and 0.22 and the gene frequencies of the three rare alleles ranged between 0.01 and 0.07.

Horizontal Die Cracking as a Yield and Reliability Problem in Integrated Circuit Devices

The problem of horizontal silicon die cracking, which can occur in CERDIP packages with glass as a die bonding material, is addressed. This fracture mode has been attributed to the combined effects of mechanical and thermal stresses. The mechanism of the fracture will be proposed and related to both the die edge condition and the die attach process. The saw-and-break die separation method is identified as the prime source of stress raisers and die edge damage. Sudden cooling causes internal thermal stress and mechanical loads in the assembly due to the solidification of the glass die attach medium and the mismatch of the coefficients of thermal expansion in the package components. The development of a nondestructive sequential screening test and accept/reject criteria for devices that are more likely to develop cracks in the field during temperature changes or slight mechanical loading are described. In addition, the results of a quantitative computer analysis are presented. This analysis is based on the finite-element method and is performed to determine temperature distribution and stress levels inside the die as a result of the cooling process. Remedial recommendations for minimizing the problem are outlined.

An agglutination assay using emulsified oils

Dispersed fluorocarbon oil droplets were used as the antigen-carrier particle in an immunological agglutination assay. The extent of agglutination was found to vary with the percentage of antigen to that of inert protein used in the solution to coat and stabilize the oil droplets. Maximum sensitivity was observed when 6.25% of the protein adsorbed on the oil droplets was specific antigen. At this percentage, antibodies were detected at concentrations as low as 0.10 μg/ml. Results were obtained by visual examination of the reacted samples as well as with quantitative computer analysis using the Zeiss IBAS image analysis system.

Quantitative computer analysis of signal sequence homologies in DNA.

Homologies to prokaryotic recognition sites for RNA polymerase, ribosomes, and cyclic-AMP receptor protein (CRP), are analyzed by a new computer program using weighting factors to account for the statistical variation at each position of the consensus. Known signal sequence sites are easily detected by this algorithm, and other sites with equally strong homology are found whose biological function is still unknown. Some sites are biologically active even though they have very weak homology. No arbitrary 'cutoff score' can distinguish active recognition sites from inactive homologies; experiments must determine why certain weak homologies are able to function while others are not.

Quantitative computer analysis of autoradiographs utilizing a charge-coupled device solid-state camera

A computerized image-processing system that employs a high resolution Datacopy Corporation charge-coupled device (CCD) camera is described. The CCD camera generates 327,680 pixels (512 horizontal axis by 640 vertical axis), eight bits per pixel (256 grey levels). The image is then processed by a Digital Graphics TKS-400 imaging computer system. The computer image corresponds to the optical density information contained in the autoradiograms. Depending on the autoradiographic information, the image can be displayed as functional maps, i.e. maps of cerebral metabolism, blood flow, neurotransmitter receptor densities, etc. This system provides quantitative computer analysis of autoradiograms in a relatively inexpensive manner.

QUANTITATIVE BIOGEOGRAPHY: AN OVERVIEW

SummaryBiogeography is currently in an exciting, challenging, revolutionary stage. Quantitative biogeography, both at the historical and ecological levels, will play an increasingly important role because rapidly increasing amounts of data will require quantitative methods and computer analysis. An effective way to comprehend quantitative methods and to determine when they can be effective is to consider any biogeographic study as a multistage decision process. Not only does this provide a framework for such activities, but it also emphasizes that one's conclusions are affected by decisions made at different stages of the study. The best perspective is that biogeography is an unending synthesis, both of many types of theories and of many types of data and analyses to test them. A corollary to this approach is that no single method or analysis can answer all questions of biogeographic interest. Finally, while computers and quantitative analyses can enhance the human mind, they can never replace it.

Characterization of the binding of the GABA agonist [3H]piperidine-4-sulphonic acid to bovine brain synaptic membranes.

The binding of radioactive piperidine-4-sulphonic acid ([3H]P4S) to thoroughly washed, frozen, and thawed membranes isolated from cow and rat brains has been studied. Quantitative computer analysis of the binding curves for four regions of bovine brain revealed the general presence of two binding sites. In these brain regions less satisfactory computer fits were obtained for receptor models showing one or three binding sites or negative cooperativity. With the use of Tris-citrate buffer at 0 degree C the two affinity classes for P4S in bovine cortex membranes revealed the following binding parameters: KD = 17 +/- 7 nM (Bmax = 0.15 +/- 0.07 pmol/mg protein) and KD = 237 +/- 100 nM (Bmax = 0.80 +/- 0.20 pmol/mg protein). Heterogeneity was also observed for association and dissociation rates of [3H]P4S. The slow binding component (kon = 5.6 X 10(7) or 8.8 X 10(7) M-1 min-1, koff = 0.83 min-1, and KD = 14.7 or 9.4 nM, determined by two different methods in phosphate buffer containing postassium chloride) corresponds to the high-affinity component of the equilibrium binding curve (KD = 11 nM, Bmax = 0.12 pmol/mg protein in the same buffer system). The association and dissociation rates for the subpopulation of rapidly of dissociating sites, apparently corresponding to the low-affinity sites, were too rapid to be measured accurately. The binding of [3H]P4S appears to involve the same two populations of sites with Bmax values similar to those for [3H]GABA binding to the same tissue, although the kinetic parameters for the two ligands are somewhat different. Furthermore, comparative studies on the inhibition of [3H]P4S and [3H]GABA binding by various GABA analogues, strongly suggest that P4S binds to the GABA receptors. The different effects of P4S and GABA on benzodiazepine binding are discussed.

Toward the optimal lead system and optimal criteria for exercise electrocardiography

To define the optimal lead system for exercise electrocardiography, data of the whole body surface potential distribution were analyzed in 25 normal subjects and in 25 patients with coronary artery disease at rest and during exercise. All patients had a normal electrocardiogram at rest. The sensitivity of the standard chest leads was 60 percent; it improved to 84 percent with the body surface map whereas both methods had a 100 percent specificity. On the basis of these data, and reports from other centers, it is concluded that a single bipolar lead from the right subclavian area to lead V 5 is adequate in those laboratories that are restricted to testing subjects with a normal electrocardiogram at rest. In patients with a previous infarction or other abnormalities in the electrocardiogram at rest three (pseudo) orthogonal leads or several standard leads are necessary. Recommendations for optimal measurements from the exercise electrocardiogram are based on quantitative computer analysis of selected leads in larger groups of patients. Best results were obtained with a combination of S-T amplitude, S-T slope and heart rate. The improvement in sensitivity from 50 percent with visual analysis to 85 percent with computer was similar to that obtained with body surface mapping. Changes of the P wave and QRS complex during exercise appeared to be of little diagnostic value. The pathophysiologic mechanisms that contribute to the changes of the electrocardiogram during exercise are discussed.

Discrimination in immunofluorescence between labeled and unlabeled cells by quantitative microfluorometry and computer analysis

An automated procedure for discrimination in immunofluorescence between antibody-labeled and unlabeled cells has been developed on the basis of microfluorimetric determination of intensity distributions. After smoothing the raw data for irregularities caused by the scoring statistics optimum fit of the negative distribution to the corresponding positive one was achieved. The procedure was tested in a model system by mixing various known proportions of immunofluorescence-negative and positive plastic beads. In addition, variable mixtures of T-negative CLL cells and normal mononuclear peripheral blood cells were labeled with FITC-conjugated anti-T-antiserum. The expected percentage of T-positive peripheral blood cells agreed satisfactorily with the data measured and computed. Finally, the measured percentage of Ig-positive mononuclear cells from normal peripheral blood was in agreement with the values obtained by other techniques.

EEG and end-tidal carbon dioxide concentration in the hyperventilation syndrome

The hyperventilation syndrome (HVS) is a functional disorder with repeated involuntary hyperventilation attacks together with symptoms of respiratory alkalosis. We have studied the EEG and end-tidal pCO 2 in the resting state and during hyperventilation activation in 12 HVS patients in order to find out whether there is a greater susceptibility to cerebral vasoconstriction in HVS patients than in controls, as indicated by slowing of the EEG. A surprisingly high proportion (58%) of abnormal resting EEGs was found in HVS patients, although the patients were neurologically normal. More theta and beta background activity was usually revealed in a quantitative computer analysis, especially frontally. Although the hyperventilation activation caused the same degree of hypocapnia in HVS patients and in controls, peripheral symptoms like tingling and numbness of fingers, as well as carpopedal spasms, occurred much more often in HVS patients. However, the EEG changes due to hyperventilation were similar in both HVS patients and normal controls, and it thus seems that the reason for cerebral symptoms in HVS patients is not a greater susceptibility to cerebral vasoconstriction.

Frequency-Dependence of Lattice Attenuation in CdS with Acoustic Domain

The lattice attenuation factor α 1 in CdS is studied experimentally by a double-pulse method and theoretically, mainly concentrating on the non-linear effect between various frequency components. The agreement between experiment and theory is very good. Under the strong flux condition (10 7 ∼18 8 times as large as the thermal level), the frequency dependence of α 1 in the range between 200 MHz and 2.5 GHz is expressed by ω 1.0 deviating largely from the Akhieser ω 2.0 -law, and in the weak flux case (10 6 ∼10 7 times), it is approximately by ω 1.8 slightly differing from the ω 2.0 -law. The deviations from ω 2.0 -law are due to the energy up-conversion from low frequency to high frequency components. The quantitative computer analysis shows that the non-linear effect due to usual lattice anharmonicity is rather important in comparison with effective anharmonicity with electrons (Hutson mechanism), in the above frequency range.

Midbrain raphe neurons: Spontaneous activity and response to light

A quantitative computer analysis was made of the spontaneous activity of 46 midbrain raphe units in the anesthetized rat. These units are characterized by a slow and rhythmic discharge rate which remains stable over time. Cells in the dorsal raphe, median raphe and brachium conjunctivum did not differ in this respect. A subpopulation of cells in the dorsal raphe exhibited regular, periodic oscillations in discharge rate. Response of raphe units to light flashes and light and dark conditions was also studied. Of 44 units tested, there was a tendency toward higher rates of discharge in the light. Effects of light flashes were examined in 34 units. Raphe cells were typically unresponsive to light flashes.

Quantitative computer analysis of cardiac and respiratory activity in newborn infants.

ArticleQuantitative computer analysis of cardiac and respiratory activity in newborn infants.P A Tarlo, I Välimäki, and P M RautaharjuP A Tarlo, I Välimäki, and P M RautaharjuPublished Online:01 Jul 1971https://doi.org/10.1152/jappl.1971.31.1.70MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByCurrent definitions for neonatal apnoea: Are they evidence based?28 May 2013 | Journal of Paediatrics and Child Health, Vol. 49, No. 9Surfactant replacement partially restores the activity of pulmonary stretch receptors in surfactant-depleted catsRichard Sindelar, Anders Jonzon, Andreas Schulze, and Gunnar Sedin1 February 2006 | Journal of Applied Physiology, Vol. 100, No. 2Spectral Analysis of Heart Rate and Blood Pressure VariabilityClinics in Perinatology, Vol. 26, No. 4Elevated arterial blood pressure is associated with peri-intraventricular haemorrhageEuropean Journal of Pediatrics, Vol. 153, No. 112 Quantification of fetal heart rate variation using a probability distribution matrixBaillière's Clinical Obstetrics and Gynaecology, Vol. 8, No. 3Continuous monitoring of heart rate variability in preterm infantsEarly Human Development, Vol. 37, No. 2Changes in autonomic cardiovascular control in mid-pregnancyClinical Physiology, Vol. 12, No. 5Effects of glycopyrrolate and atropine on heart rate variabilityActa Anaesthesiologica Scandinavica, Vol. 35, No. 5Heart rate variability in infants subsequently suffering sudden infant death syndrome (SIDS)Early Human Development, Vol. 22, No. 2Vincristine treatment of acute lymphoblastic leukemia induces transient autonomic cardioneuropathyCancer, Vol. 64, No. 4Heart rate variation in normal infants and victims of the sudden infant death syndromeEarly Human Development, Vol. 19, No. 3Multivariate autoregressive modeling of autonomic cardiovascular control in neonatal lambComputers and Biomedical Research, Vol. 21, No. 6Heart-Rate Variability and SIDS Examination of Heart-Rate Patterns Using an Expert System GeneratorAnnals of the New York Academy of Sciences, Vol. 533, No. 1 The Sudden InTranscutaneous PO2, PCO2 and heart rate patterns during normal postnatal adaptation and respiratory distressEarly Human Development, Vol. 16, No. 1Detection of components of autonomic cardiac control by time series analysis of heart rate in lambs: technical reportEffects of haemodialysis on heart rate variability in chronic renal failure8 July 2009 | Scandinavian Journal of Clinical and Laboratory Investigation, Vol. 46, No. 7Reactivity of autonomic nervous control of heart rate in diabetes mellitus and juvenile rheumatoid arthritis8 July 2009 | Scandinavian Journal of Clinical and Laboratory Investigation, Vol. 46, No. 8Analysis of neonatal heart rate variability by a microprocessor-based on-line systemJournal of Perinatal Medicine, Vol. 13, No. 5Perinatal heart rate variability and circulatory adaptation in association with normal labor and after elective cesarean sectionAmerican Journal of Obstetrics and Gynecology, Vol. 147, No. 8Impact of thermal vasomotor control on the heart rate variability of newborn infantsEarly Human Development, Vol. 8, No. 1Analysis of heart rate and beat-to-beat variability: Interval difference indexAmerican Journal of Obstetrics and Gynecology, Vol. 138, No. 3Heart rate variability in full-term normal and abnormal newborn infants during sleepBrain and Development, Vol. 1, No. 1Quantitative Characterization of Heart Rate During Exercise8 July 2009 | Scandinavian Journal of Clinical and Laboratory Investigation, Vol. 39, No. sup153Quantification of fetal heart rate variability by magnetocardiography and direct electrocardiographyAmerican Journal of Obstetrics and Gynecology, Vol. 128, No. 5REFERENCESActa Paediatrica, Vol. 63, No. s250 More from this issue > Volume 31Issue 1July 1971Pages 70-5 https://doi.org/10.1152/jappl.1971.31.1.70PubMed5556965History Published online 1 July 1971 Published in print 1 July 1971 Metrics

Quantitative Computer Analysis of Intracellularly Recorded Action Potentials

Publisher Summary This chapter discusses the quantitative computer analysis of intracellularly recorded action potentials. The systematic statistical descriptions of spontaneous neural activity enable the investigator to identify patterns of activity belonging to particular cells or neuronal networks. The chapter presents an analysis of action potentials from spontaneous firing neurons in the central nervous system of the snail Helix pomatia . On the basis of the postsynaptic potentials, five categories of neurons are selected. The interspike interval distributions are described by the interval histograms taking into account the phenomena of stationarity. The course of the firing frequency, the representation of consecutive intervals, and the serial correlogram are used as tests of stationarity. The chapter also discusses a test of independency between intervals. The standard deviation versus mean interval is described by the coefficient of variation and the power function for the five categories.