False-positive results of a rapid K39-based strip test and Chagas disease

Background: The definitive diagnosis of visceral. leishmaniasis (VL) requires invasive procedures with demonstration of amastigotes in tissue or promastigotes in culture. Unfortunately, these approaches require laboratory materials not available in poor countries where the disease is endemic. The correct diagnosis of VL is important, and made more difficult by the fact that several common tropical diseases such as malaria, disseminated tuberculosis, and enteric fever share the same clinical presentation. Serological tests have been developed to replace parasitological diagnosis in the field. A commercially available K39-based strip test for VL has been developed for this purpose. The endemic area of leishmaniasis in Brazil overlaps the endemic area of Chagas disease, a disease that can cause false-positive serological test results. The aim of this study was to evaluate the incidence of false-positive exams using a rapid test for VL in patients with Chagas disease. Methods: A rapid test based on the recombinant K39 antigen of Leishmania was used in: (1) 30 patients with confirmed Chagas disease, (2) 30 patients with a serological diagnosis of Chagas disease by ELISA, indirect immunofluorescence, indirect hemagglutination, and chemiluminescence, (3) 30 healthy patients from a non-endemic area as the control group, (4) 30 patients with confirmed VL, and (5) 20 patients with proved cutaneous leishmaniasis. Results: The sensitivity and specificity of the rapid strip test were 100% when compared with healthy volunteers and those with confirmed Chagas disease. One false-positive result occurred in the group with Chagas disease diagnosed by serological tests (specificity of 96%). Conclusion: The rapid test based on recombinant K39 is a useful diagnostic assay, and a false-positive result rarely occurs in patients with a serological diagnosis of Chagas disease. (C) 2008 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Description of costandard modules for Schur superalgebra S(2 vertical bar 1) in positive characteristic

We describe the characters of simple modules and composition factors of costandard modules for S(2 vertical bar 1) in positive characteristics and verify a conjecture of La Scala-Zubkov regarding polynomial superinvariants for GL(2 vertical bar 1).

Using Process Mapping to Facilitate Positive Library Change

This presentation was offered as part of the CUNY Library Assessment Conference, Reinventing Libraries: Reinventing Assessment, held at the City University of New York in June 2014.

Salmoninae Commensal Bacteria Show a Positive Correlation Between Antibiotic Resistance and Mercury Resistance Profiles

Bacterial isolates from natural sites with high toxic and heavy metal contamination more frequently contain determinants for resistance to antimicrobials. Natural strains were isolated from the ingesta and external slime of Salmo salar (Linnaeus, 1758) and Salvelinusjontinalis (Mitchell, 1814). Fish specimens were acquired from Casco Bay hatcheries, Casco, ME where there is no history of antibiotic use. Seventy-nine bacterial strains, including many well-documented salmonid commensals (an association from which the fish derives no benefit), were identified using 165 rRNA gene sequencing. Mercury resistant isolates were selected for initially on 25μM HgCI2. Strains were then grown at 20-24°C on Trypticase Soy Agar (TSA) plates containing 0-1000μM HgCl2 or 0-130μM Phenyl Mercuric Acetate (PMA). Mercury in the hatchery feed water due to ubiquitous non-point source deposition has selected for the mercury resistance observed in bacterial strains. Antibiotic resistance determinations, as measured by Minimum Inhibitory Concentration MIC) assays were performed on the 79 bacterial isolates using Sensititrel antimicrobial susceptibility panels. A positive linear correlation between the mercury (pMA and HgCl2) MIC's and antibiotic resistance for all observed strains was demonstrated. Conjugation experiments with Pseudomonas, Aeromonas, and Azomonas donors confirmed phenotypic transfer of penicillin and cephem resistances to Escherichia coli DH5a recipients. Conjugation experiments with Pseudomonas donors showed minimal transfer of tetracycline and minoglycoside resistances to Escherichia coli DH5a recipients. Our study suggests that the accumulation of antimicrobial resistances observed in these natural bacterial populations may be due to the indirect selective pressure exerted by environmental mercury.

On the positive correlation between income inequality and unemployment

Several empirical studies in the literature have documented the existence of a positive correlation between income inequalitiy and unemployment. I provide a theoretical framework under which this correlation can be better understood. The analysis is based on a dynamic job search under uncertainty. I start by proving the uniqueness of a stationary distribution of wages in the economy. Drawing upon this distribution, I provide a general expression for the Gini coefficient of income inequality. The expression has the advantage of not requiring a particular specification of the distribution of wage offers. Next, I show how the Gini coefficient varies as a function of the parameters of the model, and how it can be expected to be positively correlated with the rate of unemployment. Two examples are offered. The first, of a technical nature, to show that the convergence of the measures implied by the underlying Markov process can fail in some cases. The second, to provide a quantitative assessment of the model and of the mechanism linking unemployment and inequality.

The Free Trade Area of the Americas : positive outcomes for Brazil and the global community

This document discusses Brazil and the Free Trade Area of the Americas (FTAA). Since the FTAA is only a proposed agreement and trade apparatus at the moment, NAFTA is used as a working model and its influence on and benefit for Mexico and that country’s economy.

Turismo social e terceira idade:desafios emergentes

Este estudo tem por objetivo realçar e discutir dois temas de relevância atual: o turismo social e a terceira idade. O turismo social consiste em um esforço conjunto da Sociedade e do Estado em promover a universalização e a humanização da prática turística incorporando nesta atividade grupos socialmente e/ou economicamente desfavorecidos tais como os trabalhadores, os deficientes, os jovens e os idosos. Estes últimos, face ao processo de envelhecimento da população mundial ora em curso, têm assim justificada a necessidade de inclusão de suas demandas, entre as quais o direito ao lazer, no rol das políticas sociais formulado quer no âmbito estatal, quer no conjunto de ações que venha a ser adotado a nível da sociedade civil organizada. A questão da terceira idade é analisada a partir de uma pesquisa histórica que descreve a evolução do tratamento dispensado aos idosos pelas diversas sociedades, ao longo do tempo. Esta trajetória investigativa culmina com a explanação da situação atual do velho no mundo e mais especificamente no Brasil. O turismo social é abordado através da formulação de conceitos, da sua confrontação com os valores que norteiam o chamado turismo tradicional e da apresentação de experiências já postas em prática. É destacado o papel precípuo do Bureau Intemational du Tourisme Social - BITS na divulgação e no fomento desta atividade pelo mundo. Na última parte do trabalho, é feita a correlação entre os dois temas, quando então é demonstrada a importante contribuição que o lazer e o turismo social em particular têm a oferecer à população idosa como exercício completo de participação, com resultados positivos no desenvolvimento físico e mental de um estrato etário ao mesmo tempo carente e ansioso por possibilidades de integração social.

Educar para a vida: uma pedagogia da resiliência na escola

Cet étude et thème de dissertation est devenue nécessaire a partir des inquiétudes d éducateur et des pratiques pédagogiques développées aux classes d éducation physique au tour nocturne à l École Municipale Prof. Veríssimo de Melo, dont les élèves sont des jeunes et adultes que habitent au quartier Felipe Camarão. Ces jeunes cohabitent avec le stigmate de la violence que est toujours présente dans cette communauté, située a la région ouest de Natal. On peut trouvé parmi les élèves y matriculés des trajectoires de vie interrompues par facteurs de risque comme criminalité, des adolescentes enceintes et drogues. Ces faits interférent directement avec les procès d intégration sociale et augmentent la violence, reproduisant les cycles de pauvreté et ainsi, limitant les possibilités d ascension sociale. Les résultats des procédées pédagogiques utilisées pendant les classes ont montré la nécessité d approfondir cet étude problématisant cette réalité et, incitant par les pratiques corporelles et discussion, la réflexion sur des thèmes comme facteurs de risque, temporalité, projets de vie et auto-connaissance. En profitant de l intérêt de ces jeunes pour la langage cinématographique comme une façon de mettre en ouvre ces réflexions et rapportant leur connaissance formel avec le savoir et expériences du groupe on a décidé de produire un film court de 15 minutes sur le quartier, idéalisé et produit collectivement. Pour ça, ont a réalisé 10 classes-ateliers avec les élèves qui ont été connus comme « le groupe du cinéma ». Les ateliers pédagogiques qui sont ici, au même temps, référence de recherche et procédée pédagogique, réaffirment la notion de résilience: la capacité de l individu de transformer un obstacle, une adversité ou même une tragédie personnel dans une situation positive ou comme un renfort de ce que nous avons de meilleur. Dans ce sens, cet étude peut aider les professeurs de toutes les matières, que travaillent a l école publique et que se trouvent dans ce contexte, considéré vulnérable, surtout le professeur d éducation physique. Ce travail peut aussi devenir une référence pour aborder des concepts et valeurs que nos aideront à renouveler cette vision de monde étroite et déterministe, responsable pour la reproduction des cycles de pauvreté et violence. Cet étude a été fondée sur des auteurs comme Edgar Morin, Bóris Cyrulnik et Conceição Almeida parmi d autres

Waveshapes of continuing currents and properties of M-components in natural positive cloud-to-ground lightning

This work analyses the waveshapes of continuing currents and parameters of M-components in positive cloud-to-ground (CG) flashes through high-speed GPS synchronized videos. The dataset is composed of only long continuing currents (with duration longer than 40 ms) and was selected from more than 800 flashes recorded in Sao Jose dos Campos (45.864 degrees W, 23.215 degrees S) and Uruguaiana (29.806 degrees W, 57.005 degrees S) in Southeast and South of Brazil, respectively, during 2003 to 2007 summers. The videos are compared with data obtained by the Brazilian Lightning Location System (BrasilDAT) in order to determine the polarity of each flash and select only positive cases. There are only two studies of waveshapes of continuing currents in the literature. One is based on direct current measurements of triggered lightning, in which four different types of waveshapes were observed; and the other is based on measurements of luminosity variations in high-speed videos of CG negative lightning, in which besides the four types above mentioned two additional types were observed. The present work is an extension of the latter, using the same method but now applied to obtain the waveshapes of positive CG lightning. As far as the authors know, this is the first report on M-components in positive continuing currents. We also have used the luminosity-versus-time graphs to observe their occurrence and measure some parameters (duration, elapsed time and time between two successive M-components), whose statistics are presented and compared in detail to the data for negative flashes. We have plotted a histogram of the M-components elapsed time over the total duration of the continuing current for positive flashes, which presented an exponential decay (correlation coefficient: 0.83), similar to what has been observed for negative flashes. (C) 2008 Elsevier B.V. All rights reserved.

Positive leader characteristics from high-speed video observations

Based on analyses of high-speed video recordings of cloud-to-ground lightning in Brazil and the USA, the characteristics of positive cloud-to-ground (+CG) leaders are presented. The high frame rates permitted the average, 2-dimensional speeds of development along the paths of the channels to be resolved with good accuracy. The values range from 0.3 to 6.0 x 10(5) ms(-1) with a mean of 2.7 x 10(5) ms(-1). Contrary to what is usually assumed, downward +CG leader speeds are similar to downward -CG leader speeds. Our observations also show that the speeds tend to increase by a factor of 1.1 to 6.5 as they approach the ground. The presence of short duration, recoil leaders (RLs) during the development of positive leaders reveal a highly branched structure that is not usually recorded when using conventional photographic and video cameras. The existence of the RLs may help to explain observations of UHF-VHF radiation during the development of +CG flashes.

A method for plotting the complementary root locus using the root-locus (positive gain) rules

The root-locus method is a well-known and commonly used tool in control system analysis and design. It is an important topic in introductory undergraduate engineering control disciplines. Although complementary root locus (plant with negative gain) is not as common as root locus (plant with positive gain) and in many introductory textbooks for control systems is not presented, it has been shown a valuable tool in control system design. This paper shows that complementary root locus can be plotted using only the well-known construction rules to plot root locus. It can offer for the students a better comprehension on this subject. These results present a procedure to avoid problems that appear in root-locus plots for plants with the same number of poles and zeros.

Mitigation of symmetry condition in positive realness for adaptive control

Feasibility of nonlinear and adaptive control methodologies in multivariable linear time-invariant systems with state-space realization (A, B, C) is apparently limited by the standard strictly positive realness conditions that imply that the product CB must be positive definite symmetric. This paper expands the applicability of the strictly positive realness conditions used for the proofs of stability of adaptive control or control with uncertainty by showing that the not necessarily symmetric CB is only required to have a diagonal Jordan form and positive eigenvalues. The paper also shows that under the new condition any minimum-phase systems can be made strictly positive real via constant output feedback. The paper illustrates the usefulness of these extended properties with an adaptive control example. (C) 2006 Elsevier Ltd. All rights reserved.

LMI-based algorithm for strictly positive real systems with static output feedback

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Positive end-expiratory pressure in acute respiratory distress syndrome: should the 'open lung strategy' be replaced by a 'protective lung strategy'?

In patients with acute respiratory distress syndrome, positive end-expiratory pressure is associated with alveolar recruitment and lung hyperinflation despite the administration of a low tidal volume. The best positive end-expiratory pressure should correspond to the best compromise between recruitment and distension, a condition that coincides with the best respiratory elastance.