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Search Results: 1 - 10 of 11756 matches for " Laura Racster "
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Within-Subject Interlaboratory Variability of QuantiFERON-TB Gold In-Tube Tests
William C. Whitworth, Lanette R. Hamilton, Donald J. Goodwin, Carlos Barrera, Kevin B. West, Laura Racster, Laura J. Daniels, Stella O. Chuke, Brandon H. Campbell, Jamaria Bohanon, Atheer T. Jaffar, Wanzer Drane, David Maserang, Gerald H. Mazurek
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0043790
Abstract: Background The QuantiFERON?-TB Gold In-Tube test (QFT-GIT) is a viable alternative to the tuberculin skin test (TST) for detecting Mycobacterium tuberculosis infection. However, within-subject variability may limit test utility. To assess variability, we compared results from the same subjects when QFT-GIT enzyme-linked immunosorbent assays (ELISAs) were performed in different laboratories. Methods Subjects were recruited at two sites and blood was tested in three labs. Two labs used the same type of automated ELISA workstation, 8-point calibration curves, and electronic data transfer. The third lab used a different automated ELISA workstation, 4-point calibration curves, and manual data entry. Variability was assessed by interpretation agreement and comparison of interferon-γ (IFN-γ) measurements. Data for subjects with discordant interpretations or discrepancies in TB Response >0.05 IU/mL were verified or corrected, and variability was reassessed using a reconciled dataset. Results Ninety-seven subjects had results from three labs. Eleven (11.3%) had discordant interpretations and 72 (74.2%) had discrepancies >0.05 IU/mL using unreconciled results. After correction of manual data entry errors for 9 subjects, and exclusion of 6 subjects due to methodological errors, 7 (7.7%) subjects were discordant. Of these, 6 (85.7%) had all TB Responses within 0.25 IU/mL of the manufacturer's recommended cutoff. Non-uniform error of measurement was observed, with greater variation in higher IFN-γ measurements. Within-subject standard deviation for TB Response was as high as 0.16 IU/mL, and limits of agreement ranged from ?0.46 to 0.43 IU/mL for subjects with mean TB Response within 0.25 IU/mL of the cutoff. Conclusion Greater interlaboratory variability was associated with manual data entry and higher IFN-γ measurements. Manual data entry should be avoided. Because variability in measuring TB Response may affect interpretation, especially near the cutoff, consideration should be given to developing a range of values near the cutoff to be interpreted as “borderline,” rather than negative or positive.
Variability of the QuantiFERON?-TB Gold In-Tube Test Using Automated and Manual Methods
William C. Whitworth, Donald J. Goodwin, Laura Racster, Kevin B. West, Stella O. Chuke, Laura J. Daniels, Brandon H. Campbell, Jamaria Bohanon, Atheer T. Jaffar, Wanzer Drane, Paul A. Sjoberg, Gerald H. Mazurek
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0086721
Abstract: Background The QuantiFERON?-TB Gold In-Tube test (QFT-GIT) detects Mycobacterium tuberculosis (Mtb) infection by measuring release of interferon gamma (IFN-γ) when T-cells (in heparinized whole blood) are stimulated with specific Mtb antigens. The amount of IFN-γ is determined by enzyme-linked immunosorbent assay (ELISA). Automation of the ELISA method may reduce variability. To assess the impact of ELISA automation, we compared QFT-GIT results and variability when ELISAs were performed manually and with automation. Methods Blood was collected into two sets of QFT-GIT tubes and processed at the same time. For each set, IFN-γ was measured in automated and manual ELISAs. Variability in interpretations and IFN-γ measurements was assessed between automated (A1 vs. A2) and manual (M1 vs. M2) ELISAs. Variability in IFN-γ measurements was also assessed on separate groups stratified by the mean of the four ELISAs. Results Subjects (N = 146) had two automated and two manual ELISAs completed. Overall, interpretations were discordant for 16 (11%) subjects. Excluding one subject with indeterminate results, 7 (4.8%) subjects had discordant automated interpretations and 10 (6.9%) subjects had discordant manual interpretations (p = 0.17). Quantitative variability was not uniform; within-subject variability was greater with higher IFN-γ measurements and with manual ELISAs. For subjects with mean TB Responses ±0.25 IU/mL of the 0.35 IU/mL cutoff, the within-subject standard deviation for two manual tests was 0.27 (CI95 = 0.22–0.37) IU/mL vs. 0.09 (CI95 = 0.07–0.12) IU/mL for two automated tests. Conclusion QFT-GIT ELISA automation may reduce variability near the test cutoff. Methodological differences should be considered when interpreting and using IFN-γ release assays (IGRAs).
Combining Public Key Encryption with Schnorr Digital Signature  [PDF]
Laura Savu
Journal of Software Engineering and Applications (JSEA) , 2012, DOI: 10.4236/jsea.2012.52016
Abstract: This article presents a new signcryption scheme which is based on the Schnorr digital signature algorithm. The new scheme represents my personal contribution to signcryption area. I have implemented the algorithm in a program and here are provided the steps of the algorithm, the results and some examples. The paper also contains the presentation of the original Signcryption scheme, based on ElGamal digital signature and discusses the practical applications of Signcryption in real life. The purpose of the study is to combine the public key encryption with Schnorr digital signature in order to obtain less computational and communicational costs. Signcryption primitive is a better approach then Encrypt-then-Sign or Sign-then-Encrypt methods regarding the costs. All these algorithms offer the possibility to transmit a message over an insecure channel providing both authenticity and confidentiality.
Practical Stabilization for Uncertain Pseudo-Linear and Pseudo-Quadratic MIMO Systems  [PDF]
Laura Celentano
International Journal of Modern Nonlinear Theory and Application (IJMNTA) , 2013, DOI: 10.4236/ijmnta.2013.21004
Abstract:

In this paper the problem of practical stabilization for a significant class of MIMO uncertain pseudo-linear and pseudo-quadratic systems, with additional bounded nonlinearities and/or bounded disturbances, is considered. By using the concept of majorant system, via Lyapunov approach, new fundamental theorems, from which derive explicit formulas to design state feedback control laws, with a possible imperfect compensation of nonlinearities and disturbances, are stated. These results guarantee a specified convergence velocity of the linearized system of the majorant system and a desired steady-state output for generic uncertainties and/or generic bounded nonlinearities and/or bounded disturbances.

Book Announcement of L. Celentano, Robust Tracking Controllers Design with Generic References for Continuous and Discrete Uncertain Linear SISO Systems, LAP LAMBERT Academic Publishing, 2012  [PDF]
Laura Celentano
International Journal of Modern Nonlinear Theory and Application (IJMNTA) , 2014,
Abstract:

In this book new results on controller design techniques for the tracking of generic reference inputs are presented. They allow the design of a controller for an uncertain process, either continuous or discrete-time, without zeros, and with measurable state. The controller guarantees that the control system is Type 1 and has the desired constant gain and poles or that the control system tracks, with a specified maximum error and with a specified maximum time constant, a generic reference with bounded derivative (variation in the discrete-time case), also in the presence of a generic disturbance with bounded derivative (variation). In addition, it is considered the case in which the reference is known a priori.

The utility and the efficiency of the proposed methods are illustrated with attractive and significant examples of motion control and temperature control.

This book is useful for the design of control systems, especially for manufacturing systems, that are versatile, fast, precise and robust.

Gender in the American Anthology Apparatus: A Linguistic Analysis  [PDF]
Laura Aull
Advances in Literary Study (ALS) , 2014, DOI: 10.4236/als.2014.21008
Abstract:

Most American anthology and canon revision has focused on author and text selections but little on the anthology editorial apparatus. The following study responds to this gap by analyzing gender representation across prefaces and overviews of the Norton and Heath American anthologies (1979-2010). Through a combined rhetorical and corpus linguistic analysis, the study reveals disparate gender representation in these materials: women are increasingly mentioned over time, but men continue to emerge as individuals of importance while women are discussed primarily as a group. This examination suggests that the revisionist, feminist scrutiny of Norton and Heath inventory has not been brought to bear on the anthologies’ apparatus—and that discursive patterns therein remain largely invisible despite that they contradict efforts to revise gender bias in anthologies. In so doing, the study offers an exploratory analysis of new methods (combined linguistic and rhetorical analysis) and new sites (apparatus texts) for examining gender in canonical and pedagogical materials.

Does the Month of Birth Influence the Timing of Life Course Decisions? Evidence from a Natural Experiment in Italy  [PDF]
Laura Cavalli
Open Journal of Social Sciences (JSS) , 2014, DOI: 10.4236/jss.2014.21011
Abstract: Social scientists have observed for a long time a negative relationship between the time spent on education and the timing of family formation. Using data from the I.D.E.A. survey (2003), a birth-month experiment on a sample of 3000 young Italian adults is employed in order to explore whether a different month of birth leads to regular differences in life course decisions of young Italians. The results suggest that the “social” age, as determined by the school cohort, rather than the biological age, is an important determinant of the timing of demographic events during the transition to adulthood.
Controversial Theories on the Death Penalty  [PDF]
Laura Zavatta
Beijing Law Review (BLR) , 2017, DOI: 10.4236/blr.2017.82012
Abstract: The question of the right to carry firearms, but especially abolishing the death penalty, had a tremendous impact on the intellectual and political community of the whole world with the ideas of Beccaria that stimulated the urgency also of the founding fathers of the various American colonies to give life to the new Constitutions reforming the existing criminal law and proceeding to the elimination of the capital punishment in many cases. However, after about two hundred and fifty years, the death penalty, which seemed destined to be abolished by the end of the eighteenth century, is still in use in the American legal system and a great subject of debate, despite several Supreme Court rulings. Even in Italy, the period that preceded its unification, was marked by a return to the past with regard to the penal system and the conception of the death penalty. Similarly, although the European continent is “death penalty free”, and the modern criminal law is generally constituted from its rejection of torture, in recent years, with the escalation of acts of terrorism and global tension, it seems to reoccur the relationship between torture and right, as if it was a reconciliation between two old friends and a strategy to re-legalize torture.
A versatile vector system for generating recombinant EGFP-tagged proteins in yeast  [PDF]
Francesco Palma, Laura Chiarantini
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.21003
Abstract: This paper reports a versatile egfp-tagged pFL61-based expression vector system which allows the production on yeast of homo- and heterologous proteins fused with the Enhanced Green Fluorescent Protein (EGFP) at the C-terminus. This expression system, which involves a fluorescent protein, readily allows both to verify the expression and to localize the protein in the yeast cell. The vector carries a Not I site upstream the first codon of the egfp gene. The yeast cells harbouring this plasmid emit a feeble emission compared to the fluorescence expected. Was then investigated the effect of the Not I site, located very close to the start codon, on the expression of the reporter egfp gene using northern and western blotting, fluorescence microscopy and flow cytometry. Data indicated that this palindromic site could hide the start codon so as to negatively affect translation. This aspect confers to the proposed expression system an advantage in distinguishing clones after transformation.
A Case of Type I Hepatorenal Syndrome Treated with Vasopressin  [PDF]
Laura Connor, Geoffrey Teehan
Open Journal of Nephrology (OJNeph) , 2013, DOI: 10.4236/ojneph.2013.33025
Abstract:

Hepatorenal syndrome (HRS) is a grave complication of end-stage liver disease and is associated with a very high mortality. This case report described a 42-year-old female with advanced alcohol-induced cirrhosis who developed HRS that was initially treated with Midodrine and Octreotide but renal function continued to deteriorate. Vasopressin therapy was added and HRS was successfully reversed. There are few data available on the use of vasopressin for HRS and this case supports its use in treatment of HRS, particularly in countries where the more widely studied Terlipressin is unavailable. This case also demonstrates that a patient failing one medical therapy for HRS may respond to an alternative or adjunctive therapy. Therefore, this should be attempted to increase the patient’s chance of survival.

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