Laser nephelometry and radial immunodiffusion compared for immunoglobulin quantification in pathological sera.

1982 ◽  
Vol 28 (1) ◽  
pp. 180-182 ◽  
Author(s):  
H Cloppet ◽  
A Francina ◽  
H Coquelin ◽  
Y Boucaud-Maître ◽  
P Hutinel ◽  
...  

Abstract We evaluated nephelometers from Behring, Hyland, and Beckman for IgG, IgA, and IgM quantitation in sera from patients with monoclonal gammopathies. The intra-batch precision of each instrument for each immunoglobulin class and for different concentrations of the same immunoglobulin was compared to the one obtained with the radial immunodiffusion method. No nephelometer showed a clearly better precision. The correlation with cellulose acetate electrophoresis was good for each of the three nephelometers. The mean value by the radial immunodiffusion method was higher than corresponding determinations by nephelometry.

1969 ◽  
Vol 47 (4) ◽  
pp. 455-460 ◽  
Author(s):  
M. E. Kiely ◽  
E. L. Tan ◽  
T. Wood

Transketolase (EC 2.2.1.1) was purified 12-fold from an extract of dried Candida utilis by two fractionations with acetone followed by chromatography on DEAE-Sephadex. The fractions from the column were free from D-ribose 5-phosphate ketol isomerase and D-ribulose 5-phosphate 3-epimerase and could be used for the assay of D-xylulose 5-phosphate and of the epimerase. Three peaks of transketolase activity were eluted from the chromatography column; the material from each peak had a Michaelis constant for D-xylulose 5-phosphate close to the mean value for the three peaks of 6.8 × 10−5 M and gave the same two-banded pattern on cellulose acetate electrophoresis. When transaldolase was present in the material placed on the column, it appeared with transketolase in each of the three peaks. The enzyme could be stored for several months, in solution frozen at −20°. Dialysis against water caused a loss of activity which could be restored by the addition of thiamine pyrophosphate. The enzyme catalyzed the condensation of hydroxypyruvate with D-glyceraldehyde phosphate to form D-xylulose 5-phosphate.


2012 ◽  
Vol 2 (2) ◽  
pp. 10 ◽  
Author(s):  
Michael Karl Sachs ◽  
Ya-Ting Lee ◽  
Donald Turcotte ◽  
James R. Holliday ◽  
John B. Rundle

The Regional Earthquake Likelihood Models (RELM) test was the first competitive comparison of prospective earthquake forecasts. The test was carried out over 5 years from 1 January 2006 to 31 December 2010 over a region that included all of California. The test area was divided into 7682 0.1°x0.1° spatial cells. Each submitted forecast gave the predicted numbers of earthquakes <em>N<sub>emi</sub></em> larger than <em>M</em>=4.95 in 0.1 magnitude bins for each cell. In this paper we present a method that separates the forecast of the number of test earthquakes from the forecast of their locations. We first obtain the number <em>N<sub>em</sub></em> of forecast earthquakes in magnitude bin <em>m</em>. We then determine the conditional probability <em>λ<sub>emi</sub></em>=<em>N<sub>emi</sub>/</em><em>N<sub>em</sub></em> that an earthquake in magnitude bin <em>m</em> will occur in cell <em>i</em>. The summation of <em>λ<sub>emi</sub></em> over all 7682 cells is unity. A random (no skill) forecast gives equal values of <em>λ<sub>emi</sub></em> for all spatial cells and magnitude bins. The <em>skill</em> of a forecast, in terms of the location of the earthquakes, is measured by the success in assigning large values of <em>λ<sub>emi</sub></em> to the cells in which earthquakes occur and low values of <em>λ<sub>emi</sub></em> to the cells where earthquakes do not occur. Thirty-one test earthquakes occurred in 27 different combinations of spatial cells <em>i</em> and magnitude bins <em>m</em>, we had the highest value of <em>λ<sub>emi</sub></em> for that <em>mi</em> cell. We evaluate the performance of eleven submitted forecasts in two ways. First, we determine the number of <em>mi</em> cells for which the forecast <em>λ<sub>emi</sub></em> was the largest, the best forecast is the one with the highest number. Second, we determine the mean value of <em>λ<sub>emi</sub></em> for the 27 <em>mi</em> cells for each forecast. The best forecast has the highest mean value of <em>λ<sub>emi</sub></em>. The success of a forecast during the test period is dependent on the allocation of the probabilities λemi between the mi cells, since the sum over the mi cells is unity. We illustrate the forecast distributions of <em>λ<sub>emi</sub></em> and discuss their differences. We conclude that the RELM test was successful in illustrating the choices required when a forecast of the location of a future earthquake is made.


1960 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
SA Waring ◽  
LJH Teakle

The level of mineral nitrogen in the soil under fallow and crop was measured for the years 1951 to 1953. Relationships of mineral nitrogen at planting to yield and nitrogen content of wheat grain and straw were examined. Values for nitrate nitrogen at the end of the fallow period ranged most commonly from 10 to 20 µg/g in the surface 2 ft and from 0 to 10 µg/g at 2-4 ft. Approximately one-third of the sites showed an increase from the third to the fourth foot. One site showed extremely high values throughout the profile, particularly at 3-4 ft where a value of 127 µg/g was recorded. Values for ammonia nitrogen were most commonly in the range of 0-3 µg/g . Under the growing crop, mineral nitrogen declined for most depths in the period from planting up to September or October, after which there was little further change to harvest. Uptake of mineral nitrogen was normally greatest from the surface 2 ft of soil. Below 3 ft there were two groups of sites. One group showed moderate to high uptake and the second group low uptake. The low uptake in the latter group provides a reason for mineral nitrogen accumulation below 3 ft at some sites. Mineral nitrogen to 4 ft at planting averaged 126 lb/ac, excluding the one site with exceptionally high values. This was double the mean value of 63 lb/ac for nitrogen recovered in grain and straw, for crops planted in May-June. These figures, combined with trends in the soil under crop, suggest that most of the nitrogen used by the crop was derived from that in the soil at planting. Correlations between mineral nitrogen at planting and grain yield were mostly non-significant, suggesting that in general nitrogen was not an important factor limiting yield. Low grain yield and protein percentage were recorded at a number of sites which had been cultivated more than 50 years.


1869 ◽  
Vol 17 ◽  
pp. 427-429

A single reading of one end of a dipping-needle placed in a dip-circle provided with microscopes for observing is liable to a variety of instrumental errors, which are eliminated by taking the mean of the sixteen readings of the two ends in the eight different positions included in a complete observation. Nevertheless it is found that with the best modern instruments a mean value results from these sixteen observations different for each different needle, and that the difference between the results obtained with two different needles is not the same at all times. The irregularities in the values of the dip observed at Bombay with two needles of excellent character made by Barrow of London, led the author to investigate the effect of a hypothetical irregularity in the shape of the axle of the needle, such that a section of the axle by a plane perpendicular to its axis would be elliptical instead of circular in form. Another source of error, which was brought to the notice of the Royal Society many years ago in a paper published in the Proceedings, is the displacement of the centre of gravity of the needle from the centre of the axle, combined with inequality in the magnetization of the needle when the poles are direct and reversed. Experience has led the author to the conclusion that the usual method of magnetization, by a definite number of passes of the same pair of bar-magnets, communicates magnetism to the needle very unequally when the one end of the needle is made north and when the other end is made north. Consequently it is advisable to investigate the effects of ellipticity of the axle and of displacement of the centre of gravity at the same time, which the author proceeds to do.


2014 ◽  
Vol 32 (6) ◽  
pp. 706-721 ◽  
Author(s):  
Li-Wei Mai

Purpose – In recent years, there has been a big increase in the use of ethical attributes as marketing appeals. The purpose of this paper is to examine consumers’ willingness to pay for three selected ethical attributes, namely “Organic”, “Recyclable Packaging” and “Fairtrade” in monetary terms. Design/methodology/approach – A modified choice-based experimental design with manipulation of the key constructs was used to estimate the mean value of how much consumers are willing to pay for the selected attributes attached to a box of premium chocolates. The results are based on the responses of a total of 208 consumers. Findings – Of the three attributes, “Recyclable Packaging” has the strongest influence on the purchase decision, although this attribute generates the least additional value. The aggregated result shows that although consumers are willing to pay more for the product with ethical attributes than the one that is without, still around a half of them are not willing to pay more. In terms of demographics, the results show no significant differences between the two genders or different age groups in their willingness to pay for ethical attributes. As might be expected, willingness to pay was correlated with the level of consciousness of the ethical attributes. Originality/value – The findings of this study help management to think practically about the value consumers willing to pay for the selected attributes. The results show a significant synergy in a combination of ethical attributes in products.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ziyi Hou ◽  
Xiao Dang ◽  
Yezhen Yuan ◽  
Bo Tian ◽  
Sili Li

A remote monitoring system with the intelligent compaction index CMV as the core is designed and developed to address the shortcomings of traditional subgrade compaction quality evaluation methods. Based on the actual project, the correlation between the CMV and conventional compaction indexes of compaction degree K and dynamic resilient modulus E is investigated by applying the one-dimensional linear regression equation for three types of subgrade fillers, clayey gravel, pulverized gravel, and soil-rock mixed fill, and the scheme of fitting CMV to the mean value of conventional indexes is adopted, which is compared with the scheme of fitting CMV to the single point of conventional indexes in the existing specification. The test results show that the correlation between the CMV and conventional indexes of clayey gravel and pulverized gravel is much stronger than that of soil-rock mixed subgrades, and the correlation coefficient can be significantly improved by fitting CMV to the mean of conventional indexes compared with single-point fitting, which can be considered as a new method for intelligent rolling correlation verification.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Ladan Jamshidy ◽  
Hamid Reza Mozaffari ◽  
Payam Faraji ◽  
Roohollah Sharifi

Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.


1966 ◽  
Vol 12 (10) ◽  
pp. 717-727 ◽  
Author(s):  
Alex Kaplan ◽  
Murray Johnstone

Abstract Various technics for concentrating cerebrospinal fluid (CSF) prior to electrophoretic separation of the protein fractions were tested. Vacuum ultrafiltration through a collodion sac proved to be the most reliable and convenient method. The proteins in the concentrate were separated by cellulose acetate electrophoresis and quantitated densitometrically. The mean values for the various protein fractions in normal CSF were the following: 4.9% pre-albumin, 61.5% albumin, 4.5% α1 globulin, 6.7% α2 globulin, 13.7% β globulin, and 8.8% γ globulin.


1977 ◽  
Vol 9 (1-2) ◽  
pp. 84-104 ◽  
Author(s):  
Maria Amélia Cabral ◽  
Jorge Afonso Garcia

The study and analysis of the various factors influencing insurance risks constitutes an intricate and usually quite extensive problem. We have to consider on the one hand the nature and heterogeneity of the elements we have been able to measure, and on the other the problem of deciding—without knowing exactly what results to expect—on the types of analysis to carry out and the form in which to present the results.These difficulties, essentially stemming from the fact that we cannot easily define “a priori” a measure of influence, can be overcome only by using highly sophisticated mathematical models. The researcher must define his objectives clearly if he is to avoid spending too much of his time in exploring such models.Either for these reasons or for lack of our experience in this field we were led to the study of three models, presenting entirely different characteristics though based on the analysis and behaviour of mean value fluctuations, measured by their variances or by the least-squares method.Our first model, described in II. 1, associates the notion of influence with the notion of variance. It analyses in detail the alteration of the mean values variance, when what we refer to as a “margination” is executed in the parameter space, taking each of the parameters in turn. We start off by having n distinct parameters, reducing them by one with each step.


Author(s):  
UFFE HAAGERUP ◽  
STEEN THORBJØRNSEN

Let g : ℝ → ℂ be a C∞-function with all derivatives bounded and let tr n denote the normalized trace on the n × n matrices. In Ref. 3 Ercolani and McLaughlin established asymptotic expansions of the mean value 𝔼{ tr n(g(Xn))} for a rather general class of random matrices Xn, including the Gaussian Unitary Ensemble (GUE). Using an analytical approach, we provide in the present paper an alternative proof of this asymptotic expansion in the GUE case. Specifically we derive for a [Formula: see text] random matrix Xn that [Formula: see text] where k is an arbitrary positive integer. Considered as mappings of g, we determine the coefficients αj(g), j ∈ ℕ, as distributions (in the sense of L. Schwarts). We derive a similar asymptotic expansion for the covariance Cov { Tr n[f(Xn)], Tr n[g(Xn)]}, where f is a function of the same kind as g, and Tr n = n tr n. Special focus is drawn to the case where [Formula: see text] and [Formula: see text] for λ, μ in ℂ\ℝ. In this case the mean and covariance considered above correspond to, respectively, the one- and two-dimensional Cauchy (or Stieltjes) transform of the [Formula: see text].


Sign in / Sign up

Export Citation Format

Share Document