Form Of Histograms Research Articles

The assessment of antibody affinity distribution by thiocyanate elution: a simple dose-response approach

We describe a simple dose-response approach to assess the affinity distribution of polyclonal antibodies. The proportion of antigen-specific antibodies dissociated by increasing concentrations of the mild chaotropic agent ammonium thiocyanate (NH 4SCN) was measured by enzyme immunoassay, and the distribution of tolerances to this agent was presented in a histogram form. Such ‘tolerance distribution’, which is analogous to that described in classical dose-response bioassays, is proposed as a representation of the actual antibody affinity distribution. To test this approach, we assessed affinity maturation patterns of anti- Plasmodium falciparum IgG antibodies in paired sera obtained from 22 malaria patients during the acute infection and convalescence. We obtained patterns of antibody affinity distributions consistent with those previously described in immunization experiments with the aid of more complex laboratory and computational approaches. Therefore, we suggest the thiocyanate elution technique as an alternative method for rapid assessment of affinity distributions of polyclonal antibodies elicited against complex antigens, readily applicable to large number of serum samples.

Computer-assisted multidimensional atlas for functional stereotaxy.

Functional stereotactic operations are currently performed primarily for medically uncontrollable Parkinson's disease and pain. In contrast to the targets in neuro-oncology, those in functional stereotaxy cannot be represented directly by modern imaging methods. The target co-ordinates must therefore be calculated with the aid of special stereotactic atlases. These are publications in which a model brain has been constructed from autopsy examinations on a number of brains, or the data obtained have been compiled in the form of tables and histograms on which the calculation is then based. The target can then be determined based on the classic stereotactic landmarks and reference lines, such as the anterior commissure (AC), the foramen of Monro (FM), the posterior commissure (PC) or the base line FM-PC or AC-PC and the height of thalamus, taking into account the interindividually different anatomical proportions. Since the computational procedures involve repetitious algorithms, it was obvious that such procedures should be run by a computer program. For the most common stereotactic targets, we have developed a computer program for data storage on the one hand and computation and graphic output on the other. The output can be displayed on the monitor and can also be plotted out on paper or overhead transparency. Calibrating between the program and printer renders a 1:1 reproduction, i.e. the graph can be superimposed directly onto original x-rays or images from computed tomography or nuclear magnetic imaging. The graph can be plotted in the three dimensions of the Cartesian co-ordinate system. An additional dimension can be attained by simultaneously including and plotting the data from different atlases and thus from different authors, including one's own data. In addition to the information capacity which this system offers, it also makes possible a considerable reduction in the time for computing the target while at the same time increasing the reliability.

Seismic velocity structure and composition of the continental crust: A global view

Seismic techniques provide the highest‐resolution measurements of the structure of the crust and have been conducted on a worldwide basis. We summarize the structure of the continental crust based on the results of seismic refraction profiles and infer crustal composition as a function of depth by comparing these results with high‐pressure laboratory measurements of seismic velocity for a wide range of rocks that are commonly found in the crust. The thickness and velocity structure of the crust are well correlated with tectonic province, with extended crust showing an average thickness of 30.5 km and orogens an average of 46.3 km. Shields and platforms have an average crustal thickness nearly equal to the global average. We have corrected for the nonuniform geographical distribution of seismic refraction profiles by estimating the global area of each major crustal type. The weighted average crustal thickness based on these values is 41.1 km. This value is 10% to 20% greater than previous estimates which underrepresented shields, platforms, and orogens. The average compressional wave velocity of the crust is 6.45 km/s, and the average velocity of the uppermost mantle (Pn velocity) is 8.09 km/s. We summarize the velocity structure of the crust at 5‐km depth intervals, both in the form of histograms and as an average velocity‐depth curve, and compare these determinations with new measurements of compressional wave velocities and densities of over 3000 igneous and metamorphic rock cores made to confining pressures of 1 GPa. On the basis of petrographic studies and chemical analyses, the rocks have been classified into 29 groups. Average velocities, densities, and standard deviations are presented for each group at 5‐km depth intervals to crustal depths of 50 km along three different geotherms. This allows us to develop a model for the composition of the continental crust. Velocities in the upper continental crust are matched by velocities of a large number of lithologies, including many low‐grade metamorphic rocks and relatively silicic gneisses of amphibolite facies grade. In midcrustal regions, velocity gradients appear to originate from an increase in metamorphic grade, as well as a decrease in silica content. Tonalitic gneiss, granitic gneiss, and amphibolite are abundant midcrustal lithologies. Anisotropy due to preferred mineral orientation is likely to be significant in upper and midcrustal regions. The bulk of the lower continental crust is chemically equivalent to gabbro, with velocities in agreement with laboratory measurements of mafic granulite. Garnet becomes increasingly abundant with depth, and mafic garnet granulite is the dominant rock type immediately above the Mohorovicic discontinuity. Average compressional wave velocities of common crustal rock types show excellent correlations with density. The mean crustal density calculated from our model is 2830 kg/m3, and the average SiO2 content is 61.8%.

Atlantic atmospheric aerosol studies: 2. Compendium of airborne backscatter measurements at 10.6μm

The airborne backscatter measurements at 10.6 μm, from the South Atlantic Backscatter Lidar Experiment (SABLE) and the Global Atmospheric Backscatter Lidar Experiment (GABLE) programs over the Atlantic, are gathered together and presented. Plots of backscatter versus altitude are shown for 80 flight sequences. These data comprising about 4×105 measurements from over 180 flight hours is statistically analyzed. The material is distributed in altitude (1 km) and backscatter (half decade) intervals and presented in tabular and histogram form for six principal regions and seasons: South Atlantic summer, South Atlantic winter, far‐North Atlantic spring, mid‐Atlantic spring/summer, and Northeast Atlantic winter and summer. Several features of the results are discussed, including the incidence of low backscatter and drop‐outs and the remarkably high incidence of thin cirrus in the southern tropical winter season. The compendium should provide a climatology of atmospheric backscatter at 10.6 μm for regions of the Atlantic during the relatively clean atmospheric period 1988–1990.

Computer-aided image analysis applied to immunogold-silver staining: evaluation of proliferating cell nuclear antigen (PCNA)-reactive sites in paraffin sections.

Feasibility of the combination of the immunogold-silver staining method (IGSS) and computer-aided image analysis was assessed for the detection of antigen in an immunostained, paraffin-embedded section. Using low-temperature IGSS, we stained a specimen of human oral squamous cell carcinoma with a monoclonal antibody, PC 10, against a proliferating cell nuclear antigen (PCNA/cyclin), and the section was analyzed by ACAS 570 interactive laser cytometry. The PCNA-positive cells, exhibiting a heteromorphic texture, were contrasted by the dark staining of their nuclei, but showed heterogeneity in staining intensity from cell to cell. Using a conventional microscope light source rather than a laser, and by employing the COMPLEMENT DATA program (which permits inversion of the data values) installed in the ACAS 570 software system, we were able to obtain a 'complemental image' which replicated the real immunohisto-morphology. Approximately 30-35 cells from three different areas in the same section were selected by DEFINE CELL and MARK AREA programs, and quantitative image analysis was performed in terms of cell integrated value, area, perimeter, and shape factor indicated in histogram form. The combined utilization of IGSS with computer-aided image analysis was demonstrated to offer a crucial advantage for the quantitative assessment of immunostained sections.

Anwendung der Serienschnittechnik in der Gefügeanalyse / Use of the Serial Sectioning Technique for Microstructural Analysis

The application of the serial sectioning technique for the reconstruction of spatial microstructures is demonstrated using two single phase polycrystalline microstructures as examples. The materials examined are an austenitic steel and a ZnO ceramic. The practical procedure is described as well as the analysis of the planar sections. The spatial grain size distribution and number of grains per unit volume are determined using parameters obtained from planar sections. Significant differences are found between the determined spatial grain size distribution, given in histogram form, and values obtained using stereological models

Optimal histograms for limiting worst-case error propagation in the size of join results

Many current relational database systems use some form of histograms to approximate the frequency distribution of values in the attributes of relations and on this basis estimate query result sizes and access plan costs. The errors that exist in the histogram approximations directly or transitively affect many estimates derived by the database system. We identify the class of serial histograms and its subclass of end-btased histograms; the latter is of particular interest because such histograms are used in several database systems. We concentrate on equality join queries without function symbols where each relation is joined on the same attribute(s) for all joins in which it participates. Join queries of this restricted type are called t-cllque queries. We show that the optimal histogram for reducing the worst-case error in the result size of such a query is always serial. For queries with one join and no function symbols (all of which are vacuously t-clique queries), we present results on finding the optimal serial histogram and the optimal end-biased histogram based on the query characteristics and the frequency distributions of values in the join attributes of the query relations. Finally, we prove that for t-clique queries with a very large number of joins, h~gh-bzased h zstograms (which form a subclass of end-biased histograms) are always optimal. To construct a histogram for the join attribute(s) of a relation, the values in the attribute(s) must first be sorted based on their frequency and then assigned into buckets according to the optimality results above.

Use of Computer Graphics in Fitting Statistical Distribution Functions To Data Representing Random Events

This paper describes the manner in which a windows-oriented, graphical user interface can facilitate the fitting of statistical distribution functions to data representing random events. A multi featured program that can display data in the form of histo grams, fit specified distribution functions to the data and determine a distribution function that best fits the data is described and illustrated with graphical examples. The results are displayed both graphically and in tabular form. Additional features are also described. The program has been written to be compatible with the SIMAN graphical user interface, though the results are general and can be applied within any particular graphical environment.

Phoneme label alignment using acoustic-phonetic features and Gaussian probability density functions

A two-stage approach to phoneme label alignment is presented. A self-organizing neural network is employed in the first stage. The second stage performs the label alignment of an independently given input phoneme string to the corresponding speech signal. The first stage transforms signal parameters into a set of continuously valued acoustic-phonetic features. The second stage uses the Viterbi decoding/level building technique to position the label boundaries. The validity of the feature transformation approach in stage one is demonstrated in a detailed experimental analysis, the results of which are used to derive a multi-dimensional probability density model for all individual phonemes. These models are used in the second stage label alignment process. Results are given in two parts. The first provides the experimental evidence to support the use of probability density functions based on acoustic-phonetic features, in the form of histograms for a number of vocalic and consonantal Danish and British English phonemes. The second gives the results from the label alignment process. Here, differences between reference time boundaries from a manually labelled test speech corpus and time boundaries from the alignment process are presented in histograms showing the label alignment time differences for a number of selected phoneme paris for Danish and British English. The results show an overall accuracy of the label alignment of 85% and 43% for Danish and British English, respectively.

A statistical model and computer program to estimate association constants for the binding of fluorescent-labelled monoclonal antibodies to cell surface antigens and to interpret shifts in flow cytometry data resulting from alterations in gene expression

Flow cytometry is used to obtain estimates for the distribution of fluorescent ligands bound to cell surface receptors throughout a cell sample. The equipment used provides light scattering parameters and also cell staining data in the form of dot plots and histograms of fluoroscence intensities and the frequency of occurrence of particular fluorescence intensities. It is then assumed that fluorescence intensity is proportional to the number of labelled ligands bound to surface receptors. In this paper we present an outline of a statistical theory to account for the stretching and translation of such flow cytometry profiles which occur either as a result of alterations in gene expression, or from changing the sub-saturating concentration of fluorescent-labelled monoclonal antibodies or lectins used to stain the cells. We describe how the theory has been incorporated into two programs CSAFIT (cell surface antigen fit) and MAKCSA (make data to test CSAFIT). The program CSAFIT can be used to estimate two parameters, α and β, by constrained non-linear regression analysis of the flow cytometry profiles. If the shift results from changes in the concentration of a staining agent then the estimates α^ and β^ calculated by CSAFIT are functions of the ligand concentration, the ligand type and the cell line characteristics. They quantify the stretch and translation events that are encountered in flow cytometry. So when the parameter estimates α^ and β^ are then further analysed as functions of ligand concentration, estimates for the average association constant K for the binding-site/ligand interaction can be obtained. This paper describes details of the development of programs CSAFIT and MAKCSA. We also discuss the distribution of parameter estimates calculated by CSAFIT and the overall performance of CSAFIT as assessed by stimulation studies using data generated by MAKCSA.

Viscoelastic and Processing Effects on the Fiber-Matrix Interphase Strength. Part I. The Effects of Loading Rate, Test Temperature, Fiber Sizing and Global Strain Level

Abstract The effects of loading rate, fiber sizing, test temperature and global strain level on the adhesion strength between carbon fibers and a thermosetting epoxy (Epon 815) are studied using the single fiber fragmentation test procedure. Analytical methodology describing the viscoelastic behavior observed is also presented. The possibility of rate-temperature-interphase thickness superposition for the interfacial strength function is illustrated based on the analytical models discussed. Experimental data are discussed using Weibull statistics and also presented in the form of percent relative frequency histograms for the fiber fragments in a collective fashion. The use of histograms allows for interpretation of the skewness in the data population.

Viscoelastic and Processing Effects on the Fiber-Matrix Interphase Strength. Part II. The Effects of Cure Temperature Time and Curing Agent Content

Abstract The effects of curing agent content, cure temperature and time on the adhesion strength between carbon fibers (treated with epoxy sizing) and a thermosetting epoxy (Epon 815) are studied using the single fiber fragmentation test procedure. Theoretical equations describing a majority of the phenomena affecting the adhesion process are also reviewed. The possibility of superposition between percent curing agent content, cure temperature and time is illustrated based on the analytical models presented. Experimental data are presented in the form of percent relative frequency histograms for the fiber fragments in a collective fashion. Such presentation of the data allows for interpretation of the skewness in the data population. Optimum curing agent, cure temperature and time values resulting in highest interfacial strength are also determined.

The Design Of Digital Test Simulator

Digital Test Simulator is a Computer Aided Design (CAD) tools written in Turbo Pascal language ver. 5.0. It is a gate level simulator to measures the testability values of a combinational logic circuit. It was developed based on the testability analysis system called Computer-Aided MEsurefor LOgic Testability (CAMELOT). The measurement of the testability, controllability and observability for every nodes are based on the topologyical description of the circuit. The final results produced by simulator can be expressed in the form of table and histogram. Comparison of the various nodal testability values allows the areas of poor testability to be readily identified and the inprovement can be done to the circuits to make it more testable. Key Words: Logic circuit; Computer-Aided Design; CAMELOT approach; Digital Test Simulator

Probabilistic methodology for estimation of undiscovered petroleum resources in play analysis of the United States

A geostochastic system called FASPF was developed by the U.S. Geological Survey for their 1989 assessment of undiscovered petroleum resources in the United States. FASPF is a fast appraisal system for petroleum play analysis using a field-size geological model and an analytic probabilistic methodology. The geological model is a particular type of probability model whereby the volumes of oil and gas accumulations are modeled as statistical distributions in the form of probability histograms, and the risk structure is bilevel (play and accumulation) in terms of conditional probability. The probabilistic methodology is an analytic method derived from probability theory rather than Monte Carlo simulation. The resource estimates of crude oil and natural gas are calculated and expressed in terms of probability distributions. The probabilistic methodology developed by the author is explained.

Oxygen pressure histograms calculated in a block of rat heart tissue.

Measurements of oxygen pressure in tissue are usually presented in the form of oxygen histograms. In such histograms, measurements are grouped into classes of equal width and their frequency represented. An alternative view is presentation in cumulative histograms, adding the frequencies of all lower classes. Particularly for muscle tissue, including rat heart, very differing histograms were described, the lowest values being from cryophotometric measurements of myoglobin saturation (Honig and Gayeski, 1987).KeywordsOxygen TransportCapillary FlowSupply AreaCumulative HistogramCapillary SpacingThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Stochastic Treatment of Bump Latency and Temporal Overlapping in Limulus Ventral Photoreceptors

We present quantum bumps obtained from flash experiments at the Limulus ventral nerve photoreceptor under voltage clamp conditions. The results are shown and discussed in form of histograms for the latency, amplitude and net charge transfer (current time integral) of the bump current responses. We argue that the experimental latency histogram s cannot be described satisfactorily by chemical models if one assumes that not more than one photon is captured per flash. Instead of, one has to take into account the Poisson statistics of the captures of 0,1,2 ,... photons released by a single flash. We show that the inclusion of Poisson statistics makes the effective latency histograms of flash responses typically asymmetric and skewed to wards short latencies as compared to that of model histograms for one-photon responses. Our conjecture also implies that under our experimental conditions a fraction of up to 20% of the bump responses evoked by a flash should be suspected to be superpositions of two ore more one-photon responses which cannot be separated by any kind of evaluation analysis. Consequently, the average values of amplitudes and net charge transfers of the light-evoked bump responses are expected to be overestimated as compared to that of true one-photon responses. This hypothesis is confirm ed by a numerical simulation of light-evoked bump responses using experimentally recorded spontaneous bumps (at times larger than 1 s after the flash) as the simulation material. We show that the superposition of one-photon events in the light-evoked bump responses due to Poisson statistics settles the question why their amplitudes and net charge transfers are found to be larger than that of the spontaneous bumps. We suggest that true one-photon responses evoked by a light flash and spontaneous bumps start from the same activated rhodopsin state and take the same biochemical pathway.

On Collagen Fibril Diameter Distributions

Distributions of collagen fibril diameters, measured from electron micrographs, are compared using some of the common measures of the mean of the distribution. The role of mixture distributions in modelling these distributions is considered and a method of fitting such distributions to data observed in the form of histograms is described. The method is illustrated with six pairs of fibril diameter distributions used in assessing age and structural changes in various collagen samples from different species of animal. The extent of changes in diameter distributions is assessed in terms of the estimated means, variances and mixing proportions for the component distributions of the histograms in each pair.

Estimating and testing with the Bhattacharya plot

Mixtures of subpopulations of biological particles are appropriately described by finite mixture densities. Often, samples drawn from such populations are condensed in the form of histograms. In the exploratory phase of a parametrical data analysis, one wishes to obtain first estimates for the parameters of such mixtures. A parameter of special significance is the number of subpopulations. For the case of univariate normal mixtures, an explanatory graphical device called Bhattacharya Plot is presented. It allows one to obtain the required first estimates and provides assistance in the test of the normality of the mixture. The degree of overlapping in the histogram must not be too severe.

Effects of quinolinic and kynurenic acids on central neurons.

Interest in the cellular basis of the actions of kynurenines in the central nervous system can be dated to 1981 when a range of cyclic analogs of the excitatory amino acids glutamate and aspartate were tested on the excitability of neurons in the cerebral cortex of anesthetised rats (Stone and Perkins, 1981; Stone, 1984). The earliest observations were of an excitatory action of quinolinic acid on cortical neurons, an action which clearly provided some explanation for the convulsant effects of quinolinic acid reported previously by Lapin and his colleagues (see Lapin, 1989). The excitation is summarized in histogram form in Fig. 1 which also reveals one of the major properties of quinolinic acid excitation also discovered in 1981. This is the sensitivity of the response to antagonism by compounds known to be active at the population of dicarboxylic amino acid receptors which show a preference for activation by N-methyl-D-aspartate (NMDA). Thus, in Fig. 1, the cell recorded in this case in the hippocampus in vivo was excited by applications of quinolinic acid, NMDA and quisqualic acid all applied by microiontophoresis from glass micropipettes on to a single neuron in the CA1 region of the hippocampal formation. The iontophoresis of 2-amino-5-phosphonopentanoic acid (2AP5) is then able to prevent excitation in response to both quinolinic acid and NMDA, the response to quisqualic acid being unchanged.

A Maximum‐Entropy Based Heuristic for Density Estimation from Data in Histogram Form*

ABSTRACTWe look at a specific but pervasive problem in the use of secondary or published data in which the data are summarized in a histogram format, perhaps with additional mean or median information provided; two published sources yield histogram‐type summaries involving the same variable, but the two sources do not group the values of the variable the same way; the researcher wishes to answer a question using information from both data streams; and the original, detailed data underlying the published summary, which could give a better answer to the question, are unavailable. We review relevant aspects of maximum‐entropy (ME) estimation, and develop a heuristic for generating ME density estimates from data in histogram form when additional means and medians may be known. Application examples from several business and scientific areas illustrate the heuristic's use. Areas of application include business and social or market research, risk analysis, and individual risk profile analysis. Some instructional or classroom applications are possible as well.