Variance weighting functions in radioimmunoassay calibration

1986 ◽  
Vol 251 (3) ◽  
pp. E357-E361 ◽  
Author(s):  
T. W. Gettys ◽  
P. M. Burrows ◽  
D. M. Henricks

Software packages for radioimmunoassay calibration assume that expected counting rate is a function of ligand dose. Previous studies have indicated that variances of counting rate are also related to dose, but the structure of individual assays does not permit precise estimation of counting rate variances at individual doses. The method described here uses results from an accumulation of assays to characterize the relationship between mean and variance of counting rate, thus providing a variance weighting function for the calibration. Analysis of 140 cortisol assays, all with two replicates of each of 50 sources (9 standard doses, 3 quality control preps, and 38 unknowns), led to an asymmetric rising ogive relating variances to means of counting rates. A rectangular hyperbola provided an adequate characterization of this relationship in an accumulation of 21 testosterone assays. Relationships between mean and variance of counting rate in 19 growth hormone assays and 7 triiodothyronine assays were characterized by a straight line and a rising exponential curve, respectively. Calibration curves, such as the commonly adopted logistic ogive in relation to log dose, are fitted by weighted least squares to observed counts directly using empirical weights proportional to the reciprocal of estimated counting variance. The advantage of this method is that all observations contribute to the calibration in accordance with their merit.

1956 ◽  
Vol 4 (1) ◽  
pp. 126-131 ◽  
Author(s):  
L.F. Ernst

The useful formulae for the relationship between rainfall and hydraulic head are only valid for symmetrical, one-layer problems. By introducing horizontal, vertical and radial resistances in the soil profile, it was possible to obtain solutions to problems of groundwater movement in systems with only one water table under asymmetrical conditions and in soil profiles consisting of layers with widely different permeabilities. In this way the groundwater flow can be calculated from a number of linear equations. Owing to the constant resistances, in some simple cases a linear relationship is found between hydraulic head and rainfall or runoff. In a compound drainage system (ditches and tile drains, rivers and secondary watercourses) the relationship is represented by a broken straight line. A similar, nonlinear, relationship is found in a thin aquifer with an elliptic phreatic surface. An important feature of the method is the characterization of open watercourses by a single value: the radial resistance.-Author's summary. (Abstract retrieved from CAB Abstracts by CABI’s permission)


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.


Author(s):  
Bibian Bibeca Bumbila García ◽  
Hernán Andrés Cedeño Cedeño ◽  
Tatiana Moreira Chica ◽  
Yaritza Rossana Parrales Ríos

The objective of the work is to establish the characterization of the auditory disability and its relationship with resilience at the Technical University of Manabí. The article shows a conceptual analysis related to the inclusion and social integration of disabled students. Based on the fact that the person with disabilities grows and develops in the same way as that of people without disabilities and what usually happens is that disabled people are rejected and discriminated against based on a prefabricated and erroneous conceptualization of these people. The results associated with the application of the SV-RES test prepared by the researchers are shown (Saavedra & Villalta, 2008b). Characterization of the auditory deficit is made in the students, and the limitations that derive from it are pointed out. We analyze the particularities related to communication with students who have a hearing disability and resilience in this type of student, where some personal highlights that in this sense constitute an example of resilience. Finally, the results related to the study of the relationship between students' hearing disability and the level of resilience dimensions are shown.


Author(s):  
Michael C. Rea

This chapter provides a detailed characterization of the various meanings of the term “divine hiddenness,” carefully and rigorously articulates the version of the problem of divine hiddenness that has dominated contemporary philosophical discussion for the past twenty-five years, and then explains the relationship between that problem and the problem of evil.


Author(s):  
Hung Phuoc Truong ◽  
Thanh Phuong Nguyen ◽  
Yong-Guk Kim

AbstractWe present a novel framework for efficient and robust facial feature representation based upon Local Binary Pattern (LBP), called Weighted Statistical Binary Pattern, wherein the descriptors utilize the straight-line topology along with different directions. The input image is initially divided into mean and variance moments. A new variance moment, which contains distinctive facial features, is prepared by extracting root k-th. Then, when Sign and Magnitude components along four different directions using the mean moment are constructed, a weighting approach according to the new variance is applied to each component. Finally, the weighted histograms of Sign and Magnitude components are concatenated to build a novel histogram of Complementary LBP along with different directions. A comprehensive evaluation using six public face datasets suggests that the present framework outperforms the state-of-the-art methods and achieves 98.51% for ORL, 98.72% for YALE, 98.83% for Caltech, 99.52% for AR, 94.78% for FERET, and 99.07% for KDEF in terms of accuracy, respectively. The influence of color spaces and the issue of degraded images are also analyzed with our descriptors. Such a result with theoretical underpinning confirms that our descriptors are robust against noise, illumination variation, diverse facial expressions, and head poses.


Author(s):  
Livio Cricelli ◽  
Michele Grimaldi ◽  
Silvia Vermicelli

AbstractIn recent years, Open Innovation (OI) and crowdsourcing have been very popular topics in the innovation management literature, attracting significant interest and attention, and inspiring a rich production of publications. Although these two topics share common themes and address similar managerial challenges, to the best of our knowledge, there is no systematic literature review that digs deep into the intersection of both fields. To fill in this gap a joint review of crowdsourcing and OI topics is both timely and of interest. Therefore, the main objective of this study is to carry out a comprehensive, systematic, and objective review of academic research to help shed light on the relationship between OI and crowdsourcing. For this purpose, we reviewed the literature published on these two topics between 2008 and 2019, applying two bibliometric techniques, co-citation and co-word analysis. We obtained the following results: (i) we provide a qualitative analysis of the emerging and trending themes, (ii) we discuss a characterization of the intersection between OI and crowdsourcing, identifying four dimensions (strategic, managerial, behavioral, and technological), (iii) we present a schematic reconceptualization of the thematic clusters, proposing an integrated view. We conclude by suggesting promising opportunities for future research.


1999 ◽  
Vol 179 (6) ◽  
pp. 1561-1564 ◽  
Author(s):  
Paul D. Fey ◽  
Joseph S. Ulphani ◽  
Friedrich Götz ◽  
Christine Heilmann ◽  
Dietrich Mack ◽  
...  

Morphology ◽  
2021 ◽  
Author(s):  
Rossella Varvara ◽  
Gabriella Lapesa ◽  
Sebastian Padó

AbstractWe present the results of a large-scale corpus-based comparison of two German event nominalization patterns: deverbal nouns in -ung (e.g., die Evaluierung, ‘the evaluation’) and nominal infinitives (e.g., das Evaluieren, ‘the evaluating’). Among the many available event nominalization patterns for German, we selected these two because they are both highly productive and challenging from the semantic point of view. Both patterns are known to keep a tight relation with the event denoted by the base verb, but with different nuances. Our study targets a better understanding of the differences in their semantic import.The key notion of our comparison is that of semantic transparency, and we propose a usage-based characterization of the relationship between derived nominals and their bases. Using methods from distributional semantics, we bring to bear two concrete measures of transparency which highlight different nuances: the first one, cosine, detects nominalizations which are semantically similar to their bases; the second one, distributional inclusion, detects nominalizations which are used in a subset of the contexts of the base verb. We find that only the inclusion measure helps in characterizing the difference between the two types of nominalizations, in relation with the traditionally considered variable of relative frequency (Hay, 2001). Finally, the distributional analysis allows us to frame our comparison in the broader coordinates of the inflection vs. derivation cline.


2021 ◽  
pp. 003151252110162
Author(s):  
Cleiton Pereira Reis ◽  
Juan Carlos Pérez Morales ◽  
Cristiano Mauro Assis Gomes ◽  
Fernando de Azevedo Alves Pereira ◽  
Sergio José Ibáñez

Measuring basketball players’ declarative tactical knowledge is relevant to the teaching and learning process. In this study we aimed to verify the construct validity and construct reliability of the Instrument for Measuring Declarative Tactical Knowledge in Basketball (IMDTK-Bb). We recruited 1,188 male basketball athletes aged 10-19 years old. We used confirmatory factor analysis with weighted least squares mean and variance estimator for construct validation and MacDonald´s omega for internal consistency. We established a final model with 17 scenes referring to the declarative tactical knowledge and type of action players used to solve game situations the scenes represented. The final model presented a good Comparative Fit Index (CFI = 1.000), Tucker–Lewis Index (TLI = 1.001) and Root Mean Square Error of Approximation (RMSEA = .000). The reliability index was .779. We conclude that the IMDTK-Bb has good construct validity and can be used in further research.


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