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Search Results: 1 - 10 of 410452 matches for " Claudia M. Denkinger "
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Do We Need to Detect Isoniazid Resistance in Addition to Rifampicin Resistance in Diagnostic Tests for Tuberculosis?
Claudia M. Denkinger, Madhukar Pai, David W. Dowdy
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084197
Abstract: Background Multidrug-resistant tuberculosis (MDR-TB) is resistant to both rifampicin (RIF) and isoniazid (INH). Whereas many TB diagnostics detect RIF-resistance, few detect INH-monoresistance, which is common and may increase risk of acquired MDR-TB. Whether inclusion of INH-resistance in a first-line rapid test for TB would have an important impact on MDR-TB rates remains uncertain. Methods We developed a transmission model to evaluate three tests in a population similar to that of India: a rapid molecular test for TB, the same test plus RIF-resistance detection (“TB+RIF”), and detection of RIF and INH-resistance (“TB+RIF/INH”). Our primary outcome was the prevalence of INH-resistant and MDR-TB at ten years. Results Compared to the TB test alone and assuming treatment of all diagnosed MDR cases, the TB+RIF test reduced the prevalence of MDR-TB among all TB cases from 5.5% to 3.8% (30.6% reduction, 95% uncertainty range, UR: 17–54%). Despite using liberal assumptions about the impact of INH-monoresistance on treatment outcomes and MDR-TB acquisition, expansion from TB+RIF to TB+RIF/INH lowered this prevalence only from 3.8% to 3.6% further (4% reduction, 95% UR: 3–7%) and INH-monoresistant TB from 15.8% to 15.1% (4% reduction, 95% UR: (-8)-19%). Conclusion When added to a rapid test for TB plus RIF-resistance, detection of INH-resistance has minimal impact on transmission of TB, MDR-TB, and INH-monoresistant TB.
Challenges in the Development of an Immunochromatographic Interferon-Gamma Test for Diagnosis of Pleural Tuberculosis
Claudia M. Denkinger, Yatiraj Kalantri, Samuel G. Schumacher, Joy S. Michael, Deepa Shankar, Arvind Saxena, Natarajan Sriram, Thangakunam Balamugesh, Robert Luo, Nira R. Pollock, Madhukar Pai, Devasahayam J. Christopher
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0085447
Abstract: Existing diagnostic tests for pleural tuberculosis (TB) have inadequate accuracy and/or turnaround time. Interferon-gamma (IFNg) has been identified in many studies as a biomarker for pleural TB. Our objective was to develop a lateral flow, immunochromatographic test (ICT) based on this biomarker and to evaluate the test in a clinical cohort. Because IFNg is commonly present in non-TB pleural effusions in low amounts, a diagnostic IFNg-threshold was first defined with an enzyme-linked immunosorbent assay (ELISA) for IFNg in samples from 38 patients with a confirmed clinical diagnosis (cut-off of 300pg/ml; 94% sensitivity and 93% specificity). The ICT was then designed; however, its achievable limit of detection (5000pg/ml) was over 10-fold higher than that of the ELISA. After several iterations in development, the prototype ICT assay for IFNg had a sensitivity of 69% (95% confidence interval (CI): 50-83) and a specificity of 94% (95% CI: 81-99%) compared to ELISA on frozen samples. Evaluation of the prototype in a prospective clinical cohort (72 patients) on fresh pleural fluid samples, in comparison to a composite reference standard (including histopathological and microbiologic test results), showed that the prototype had 65% sensitivity (95% CI: 44-83) and 89% specificity (95% CI: 74-97). Discordant results were observed in 15% of samples if testing was repeated after one freezing and thawing step. Inter-rater variability was limited (3%; 1out of 32). In conclusion, despite an iterative development and optimization process, the performance of the IFNg ICT remained lower than what could be expected from the published literature on IFNg as a biomarker in pleural fluid. Further improvements in the limit of detection of an ICT for IFNg, and possibly combination of IFNg with other biomarkers such as adenosine deaminase, are necessary for such a test to be of value in the evaluation of pleural tuberculosis.
Point-of-Care Testing for Infectious Diseases: Diversity, Complexity, and Barriers in Low- And Middle-Income Countries
Nitika Pant Pai,Caroline Vadnais,Claudia Denkinger,Nora Engel,Madhukar Pai
PLOS Medicine , 2012, DOI: 10.1371/journal.pmed.1001306
Non-Linear Semi-Quantum Hamiltonians and Its Associated Lie Algebras  [PDF]
Claudia M. Sarris, Angelo Plastino
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.520306
Abstract: We show that the non-linear semi-quantum Hamiltonians which may be expressed as\"\"(where\"\"is the set of generators of some Lie algebra and are the classical conjugated canonical variables) always close a partial semi Lie algebra under commutation and\"\", because of this, it is always possible to integrate the mean values of the quantum degrees of freedom of the semi-quantum non-linear system in the fashion:\"\"(where\"\"is the Maximum Entropy Principle density operator) and, so, these kind of Hamiltonians always have associated dynamic invariants which are expressed in terms of the quantum degrees of freedom’s mean values. Those invariants are useful to characterize the kind of dynamics (regular or irregular) the system displays given that they can be fixed by means of the initial conditions imposed on the semi-quantum non-linear system.
Uncertainty Principle and Bifurcations in the SU(2) Nonlinear Semiquantum Dynamics  [PDF]
Roberta Hansen, Claudia M. Sarris, Angelo Plastino
Applied Mathematics (AM) , 2018, DOI: 10.4236/am.2018.91001
In this paper, a nonlinear semiquantum Hamiltonian associated to the special unitary group SU(2) Lie algebra is studied so as to analyze its dynamics. The treatment here applied allows for a reduction in: 1) the system’s dimension, as well as 2) the number of system’s parameters (to only three). We can now discern clear patterns in: 1) the complete characterization of the system’s fixed points and 2) their stability. It is shown that the parameter associated to the uncertainty principle, which constitutes a very strong constraint, is the key one in determining the presence of fixed points and bifurcation curves in the parameter’s space.
Self-Concept in Kindergarten and First Grade Children: A Longitudinal Study on Structure, Development, and Relation to Achievement  [PDF]
Laura C. Dapp, Claudia M. Roebers
Psychology (PSYCH) , 2018, DOI: 10.4236/psych.2018.97097
Abstract: The self-concept refers to a multidimensional construct that organizes a person’s self-perceptions into a hierarchical structure comprising global and specific facets. Children’s self-concept, however, is believed to be less differentiated and less realistic, as children tend to systematically overestimate their abilities. Since little research has been conducted with children before the beginning of formal schooling, the present longitudinal study aimed to explore the structure of kindergarten children’s self-concept, its development during the transition to school, as well as the links between self-concept and achievement in first grade. Counteracting the positively biased self-ratings in children, self-concept was assessed by an innovative measurement instrument that allows for fine-tuned self-evaluations. Structural Equation Modeling showed that kindergarten children’s self-concept is already organized in a multidimensional structure, and thus, differentiates much earlier than previously believed. Like the self-concept of adults, kindergarten children’s self-concept is composed of domain-specific facets, comprising literacy, mathematical, peer-related and teacher-related self-concept aspects. Moreover, gender stereotype conforming differences—like boys having a higher mathematical and girls having a higher social self-concept—already seem to develop at such a young age. Upon first grade entry, children’s academic self-concept increases and becomes positively related to achievement, indicating at least some realism in children’s self-perceptions. Taken together, the findings provide new insights into the structure, development, and validity of young children’s self-concept, contributing substantially to the generalizability of a multidimensionally organized self-concept.
Azospirillum Growth Promotion Is Related to Changes in Ferulate and Dehydrodiferulate Contents in Cell Wall of Inoculated Cucumber Seedlings Hypocotyls  [PDF]
Claudia C. Dal Lago, Cecilia M. Creus, M. Alejandra Pereyra
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.610165
Abstract: Azospirillum brasilense is a well known plant growth-promoting rhizobacterium. Plant cell growth is constrained by the primary cell wall (CW) which contains polysaccharide-bound hydroxycinammic acids (HCAs). They derive from phenylpropanoid metabolism, which first step is the reaction catalyzed by phenylalanine ammonia-lyase (PAL; EC Also CW peroxidases (FAPOD; EC play a key role in the stiffening of the CW, and in the cessation of cell elongation. Knowledge of the biochemical effects the bacteria could elicit into plant CW and how these responses could change the hypocotyl physiology still remains scarce. The objective of this work was to unravel the effects of A. brasilense Sp245 inoculation on HCAs of the primary CW in apical and basal segments of cucumber seedlings hypocotyls. Azospirillum inoculation increased hypocotyls’ length. Transferulate and p-coumarate were the major HCAs. Dimmers were detected only in the basal region of 13- and 15-d-old hypocotyls. The ratio t-ferulate/dimmer (an inverse index of CW cross-linking) was five times higher in inoculated seedlings. Enzyme activities determined were not directly involved in HCAs content changes. It was previously reported that the CW was a target for A. brasilense growth promotion. This work corroborates that the phenolics, FA, DFA, and p-coumarate bound to the CW are also involved in Azospirillum plant growth promoting strategies.
Sentence comprehension: effectors and goals, self and others. An overview of experiments and implications for robotics
Anna M. Borghi,Claudia Gianelli,Claudia Scorolli
Frontiers in Neurorobotics , 2010, DOI: 10.3389/fnbot.2010.00003
Abstract: According to theories referring to embodied and grounded cognition (Barsalou, 2008 ), language comprehension encompasses an embodied simulation of actions. The neural underpinnings of this simulation could be found in wide neural circuits that involve canonical and mirror neurons (Rizzolatti et al., 1996 ). In keeping with this view, we review behavioral and kinematic studies conducted in our lab which help characterize the relationship existing between language and the motor system. Overall, our results reveal that the simulation evoked during sentence comprehension is fine-grained, primarily in its sensitivity to the different effectors we employ to perform actions. In addition, they suggest that linguistic comprehension also relies on the representation of actions in terms of goals and of the chains of motor acts necessary to accomplish them. Finally, they indicate that these goals are modulated by both the object features the sentence refers to as well as by social aspects such as the characteristics of the agents implied by sentences. We will discuss the implications of these studies for embodied robotics.
Ajenidad en dos poetas mapuches contemporáneos: Chihuailaf y Lienlaf
Rodríguez M,Claudia;
Estudios filológicos , 2004, DOI: 10.4067/S0071-17132004003900014
Abstract: this paper examines both in its verbal and territorial aspects of estrangement as a recurrent element present in the mapuche writers leonel lienlaf and elicura chihuailaf. de la pérdida al encuentro sets up the pendulum movement that leads the poetical word of these two bilingual writers as well as the silence, space and abyss which take shape in the unsayable and untranslatable identity in the context of intercultural relationships.
Vladimir Prelog e a estereoquímica das moléculas organicas: um centenário de nascimento
Rezende, Claudia M.;
Química Nova , 2007, DOI: 10.1590/S0100-40422007000400050
Abstract: the croatian chemist vladimir prelog shared in 1975 the nobel prize in chemistry with j. w. cornforth for his research into the stereochemistry of organic molecules and reactions. his studies gave new horizons to the comprehension of steric effects on the reactivity of medium-sized rings, to conformational analysis and to the stereospecificity associated to asymmetric syntheses. prelog made important contributions to enzyme chemistry and to the structure elucidation of alkaloids and of antibiotics from microorganisms, but probably his most famous work is the cip system for assigning the stereochemistry of chiral centers.
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