The role of proficiency testing in the detection and resolution of calibration bias in the LeadCare® blood lead analyzer; limitations of peer-group assessment

2006 ◽  
Vol 11 (11) ◽  
pp. 590-592 ◽  
Author(s):  
Noel V. Stanton ◽  
Tracy Fritsch ◽  
Ciaran Geraghty ◽  
Mary Frances Verostek ◽  
Bruce Weiner ◽  
...  
Keyword(s):  
Proficiency Testing ◽  
Peer Group ◽  
Blood Lead ◽  
Group Assessment

scholarly journals Placing women in Cytogenetics: Lore Zech and the chromosome banding technique

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Felicitas Söhner ◽  
Nils Hansson
Keyword(s):  
Peer Group ◽  
Secondary Analysis ◽  
Qualitative Evaluation ◽  
Banding Technique ◽  
Karolinska Institute ◽  
New Era ◽  
Human Cytogenetics ◽  
History Of ◽  
Witness Interviews

Abstract Background Scholars agree that Torbjörn Caspersson’s lab at the Institute of Medical Cell Research and Genetics at the Karolinska Institute, Sweden, played a key role in the first description of the so-called Q-banding technique. It laid the foundation for a new era of cytogenetic diagnostics and had a lasting impact in several areas of biology and medicine. Methods Based on a mixed-method approach, essential aspects of the history of human cytogenetics are considered via primary and secondary analysis of biographical interviews as well as the qualitative evaluation of bibliometrics. Drawing on interviews with colleagues of lab member Lore Zech (1923–2013) and contemporary publications, this paper illuminates the role of and contribution by Zech: To what extent is the discovery attached to her and what does her legacy look like today? Results The analysis of the contemporary witness interviews with colleagues, students and junior researchers shows that Lore Zech was a committed member of Caspersson's research group. In addition, memoirs by contemporary colleagues describe her outstanding skills in microscopy. The different sources paint a multifaceted picture. In addition to the historians' patterns of interpretation, different legacies can also be found within the peer group. Conclusions We argue that Zech represent the type of scientist who, although her research was acknowledged with several prizes, so far has not been part of the canon of pioneers of international cytogenetics.

Determinants of U.S. Exports to China

2008 ◽  
Vol 7 (3) ◽  
pp. 1-26 ◽  
Author(s):  
Barry Bosworth ◽  
Susan M. Collins
Keyword(s):  
United States ◽  
Multinational Corporations ◽  
Peer Group ◽  
Initial Point ◽  
The United States ◽  
Market Size ◽  
Gravity Equations ◽  
Point Of Departure ◽  
The Eu

This paper examines U.S. goods trade with China, focusing on the performance of exports. Throughout the analysis, we explore whether U.S. trade is unusual by contrasting it with trade from Japan and the EU-15.1 The issue is examined from three perspectives: the commodity composition of exports, the role of multinational corporations (MNCs), and the determinants of trade as specified in a formal “gravity model.” As an initial point of departure, we show that the commodity composition of U.S. exports to China is similar to the pattern of exports to the world as a whole, and that the operations of U.S. MNCs have only minor implications for trade with China. Consequently, we emphasize the estimation of a set of “gravity equations” that explore the role of market size and distance from the United States. Distance exerts a surprisingly large effect on trade. Finally, although exports to China may be a small share of U.S. GDP, they are relatively substantial compared to U.S. exports to other countries. In other words, the measure of U.S. trade performance in China is distorted by the low level of its exports to all countries. We present evidence that the United States underperforms as an exporter relative to a peer group of high-income European countries and Japan.

The Role of Blood Lead, Cadmium, Zinc and Copper in Development and Severity of Acne Vulgaris in a Nigerian Population

2016 ◽  
Vol 176 (2) ◽  
pp. 251-257 ◽  
Author(s):  
C.I. Ikaraoha ◽  
N.C. Mbadiwe ◽  
C.J. Anyanwu ◽  
J. Odekhian ◽  
C.N. Nwadike ◽  
...  
Keyword(s):  
Acne Vulgaris ◽  
Blood Lead ◽  
Nigerian Population ◽  
Cadmium Zinc

Performance Characteristics of Several Rules for Self-interpretation of Proficiency Testing Data

2005 ◽  
Vol 129 (8) ◽  
pp. 997-1003 ◽  
Author(s):  
R. Neill Carey ◽  
George S. Cembrowski ◽  
Carl C. Garber ◽  
Zohreh Zaki
Keyword(s):  
Proficiency Testing ◽  
Error Detection ◽  
Clinical Laboratory ◽  
Peer Group ◽  
Simulation Techniques ◽  
Allowable Error ◽  
Detection Capabilities ◽  
The Mean ◽  
The Difference

Abstract Context.—Proficiency testing (PT) participants can interpret their results to detect errors even when their performance is acceptable according to the limits set by the PT provider. Objective.—To determine which rules for interpreting PT data provide optimal performance for PT with 5 samples per event. Design.—We used Monte Carlo computer simulation techniques to study the performance of several rules, relating their error detection capabilities to (1) the analytic quality of the method, (2) the probability of failing PT, and (3) the ratio of the peer group SD to the mean intralaboratory SD. Analytic quality is indicated by the ratio of the PT allowable error to the intralaboratory SD. Failure of PT was defined (Clinical Laboratory Improvement Amendments of 1988) as an event when 2 or more results out of 5 exceeded acceptable limits. We investigated rules with limits based on the SD index, the mean SD index, and percentages of allowable error. Results.—No single rule performs optimally across the range of method quality. Conclusions.—We recommend further investigation when PT data cause rejection by any of the following 3 rules: any result exceeds 75% of allowable error, the difference between any 2 results exceeds 4 times the peer group SD, or the mean SD index of all 5 results exceeds 1.5. As method quality increases from marginal to high, false rejections range from 16% to nearly zero, and the probability of detecting a shift equal to 2 times the intralaboratory SD ranges from 94% to 69%.

The Magic of Mesosystems, Seedbeds of Solidarity

2020 ◽  
pp. 74-94
Author(s):  
Barbara Bennett Woodhouse
Keyword(s):  
Social Cohesion ◽  
Peer Group ◽  
Social Institutions ◽  
Community Identity ◽  
Community School ◽  
Political Movements ◽  
Economic Policies ◽  
Building Community ◽  
Friendly Competition

Chapter four explores how the activities and relationships occurring in the spaces where microsystems overlap function as seedbeds of solidarity, generating a shared sense of identity, fostering social cohesion and transforming “other people’s children” into “our children.” The author focuses on interactions among the primary social institutions comprising children’s microsystems: family, faith community, school, peer group, and neighbourhood. Drawing on observations from the villages under study, the author illustrates the dynamic created when these social institutions cooperate, collaborate and even engage in friendly competition in support of the community’s children. The chapter highlights the role of rituals and traditions in building community identity and solidarity in both villages. It explores how village identity can endure across time and distance in migrants’ attachments to their home towns. In closing, it predicts further erosion of community identity due to global economic policies and divisive political movements.

scholarly journals Evaluation of Blood Lead Proficiency Testing: Comparison of Open and Blind Paradigms

2001 ◽  
Vol 47 (2) ◽  
pp. 322-330 ◽  
Author(s):  
Patrick J Parsons ◽  
Andrew A Reilly ◽  
Debra Esernio-Jenssen ◽  
Lloyd N Werk ◽  
Howard C Mofenson ◽  
...  
Keyword(s):  
New York ◽  
Proficiency Testing ◽  
Clinical Laboratory ◽  
Phase 1 ◽  
New York State ◽  
Blood Lead ◽  
York State Department ◽  
Clinical Laboratories ◽  
Significant Difference ◽  
Double Blinded

Abstract Background: Most proficiency testing (PT) programs operate with an open design in which clearly identified performance samples are distributed directly to participating laboratories on a shipping schedule announced in advance. In this study, we examine the effectiveness of assessing clinical laboratory performance for blood lead with an open PT by comparing its results with a double-blinded testing protocol. Methods: Aliquots from up to 72 blood lead performance pools from the New York State Department of Health and the Wisconsin State Laboratory of Hygiene were disguised as routine patient specimens and submitted in two phases to up to 42 certified clinical laboratories for blood lead analysis. These 42 laboratories also received aliquots of the same performance samples for blood lead analysis directly from the “open” PT program provider. Results: Data reported under blind and open strategies were scored against acceptable target ranges using the Clinical Laboratory Improvement Amendments of 1988 (CLIA ’88) criteria established for blood lead, i.e., ± 0.19 μmol/L (± 4 μg/dL) or ± 10%, whichever is greater. Performance differences between the strategies were also assessed. We found that 17.7% of all blind PT results were classified as unacceptable compared with only 4.5% of open PT results (P <0.001). In phase 1, 13 of 22 laboratories (60%) exhibited a statistically significant difference (P <0.05) between their blind and open PT performances, although for 6 laboratories the poorer blind performance may not necessarily have led to unsuccessful PT participation under CLIA ’88 criteria. Seven (32%) laboratories had unsuccessful aggregate performance (<80%) under blind testing while maintaining successful performance in open testing. Of these seven, two had gross discrepancies motivating further investigation. Conclusions: The data suggest that although ∼60% of clinical laboratories make special efforts to improve analytical performance on open PT samples relative to performance achieved for routine patient specimens, in most cases the differences are clinically insignificant and would not likely affect cumulative PT performance. Occasional use of blind PT may deter the inclination to treat performance samples more carefully.

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