Overdamped van Hove function of atomic liquids

Using the generalized Langevin equation formalism and the process of contraction of the description we derive a general memory function equation for the thermal fluctuations of the local density of a simple atomic liquid. From the analysis of the long-time limit of this equation, a striking equivalence is suggested between the long-time dynamics of the atomic liquid and the dynamics of the corresponding \emph{Brownian} liquid. This dynamic equivalence is confirmed here by comparing molecular and Brownian dynamics simulations of the self-intermediate scattering function and the long-time self-diffusion coefficient for the hard-sphere liquid.Comment: 4 Figures, 23 page

Factores que influyen en la reprobación en la educación media superior bajo un modelo por competencias

En este trabajo se identificaron algunos factores que influyen en la reprobación estudiantil en el nivel medio superior, trabajando bajo un modelo por competencias, en el área de matemáticas. La investigación se realizó en la Escuela Industrial y Preparatoria Técnica “Pablo Livas” (EIPTPL) perteneciente a la Universidad Autónoma de Nuevo León, analizando la unidad de aprendizaje Matemáticas I, la cual se imparte en el segundo semestre, correspondiente al semestre Enero-Junio 2014. Los factores que se consideraron fueron al docente, las actividades que se realizan, el programa analítico y el propio estudiante. La recopilación de datos se realizó a través de una encuesta, que se aplicó a una muestra representativa de estudiantes inscritos a la unidad de aprendizaje Matemáticas II y que hubiesen reprobado la primera oportunidad de Matemáticas I. Se obtuvieron resultados que nos permiten determinar al docente junto con las actividades como principales factores que afectan a los estudiantes para reprobar Matemáticas I

In-house nucleic acid amplification tests for the detection of Mycobacterium tuberculosis in sputum specimens: meta-analysis and meta-regression

BACKGROUND: More than 200 studies related to nucleic acid amplification (NAA) tests to detect Mycobacterium tuberculosis directly from clinical specimens have appeared in the world literature since this technology was first introduced. NAA tests come as either commercial kits or as tests designed by the reporting investigators themselves (in-house tests). In-house tests vary widely in their accuracy, and factors that contribute to heterogeneity in test accuracy are not well characterized. Here, we used meta-analytical methods, including meta-regression, to identify factors related to study design and assay protocols that affect test accuracy in order to identify those factors associated with high estimates of accuracy. RESULTS: By searching multiple databases and sources, we identified 2520 potentially relevant citations, and analyzed 84 separate studies from 65 publications that dealt with in-house NAA tests to detect M. tuberculosis in sputum samples. Sources of heterogeneity in test accuracy estimates were determined by subgroup and meta-regression analyses. Among 84 studies analyzed, the sensitivity and specificity estimates varied widely; sensitivity varied from 9.4% to 100%, and specificity estimates ranged from 5.6% to 100%. In the meta-regression analysis, the use of IS6110 as a target, and the use of nested PCR methods appeared to be significantly associated with higher diagnostic accuracy. CONCLUSION: Estimates of accuracy of in-house NAA tests for tuberculosis are highly heterogeneous. The use of IS6110 as an amplification target, and the use of nested PCR methods appeared to be associated with higher diagnostic accuracy. However, the substantial heterogeneity in both sensitivity and specificity of the in-house NAA tests rendered clinically useful estimates of test accuracy difficult. Future development of NAA-based tests to detect M. tuberculosis from sputum specimens should take into consideration these findings in improving accuracy of in-house NAA tests

Estados de ánimo y juicios de autoconcepto en universitarios: Análisis desde un abordaje basado en redes semánticas naturales

Fil: Flores Kanter, E. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Fil: Manoiloff, Laura María Victoria. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Fil: Medrano, L. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Dentro del estudio de la percepción de sí mismo se han desarrollado investigaciones que intentan observar las consecuencias de los estados afectivos, y más específicamente, los efectos de los estados de ánimo sobre la percepción de sí (Sedikide, 1992). La presente investigación sigue esta dirección, y se plantea como objetivo indagar la relación entre el estado de ánimo y los juicios de autoconcepto. Si bien pueden mencionarse algunos estudios precedentes (Sedikides, 1995), no se encuentran desarrollos a nivel local. Además, este trabajo busca observar la relación entre los estados de ánimo y la parte cognoscitiva del autoconcepto mediante una técnica que no ha sido utilizada en las investigaciones previas, la Técnica de Redes Semánticas Naturales (RSN) (Ramírez; Martínez; Montemayor y Nieto, 2009; Valdez, 2002). Los resultados obtenidos son coherentes con la Teoría de la Red Asociativa y el Modelo de Infusión del Afecto (Bower y Forgas, 2003). De este modo, pudo observarse una congruencia entre el estado de ánimo (positivo y negativo) y la definición de sí mismo (positividad y negatividad del autoconcepto), así como en la cantidad de palabras positivas y negativas utilizadas para definirse. Esta investigación es parte de un proyecto más amplio, que propone en segunda instancia utilizar un diseño experimental a través de la inducción de estados de ánimo. Con todo, la novedad sigue radicando en la metodología de RSN como forma de analizar los efectos del estado de ánimo sobre la definición de uno mismo.http://www.revistas.unc.edu.ar/index.php/racc/article/view/5108/5280Fil: Flores Kanter, E. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Fil: Manoiloff, Laura María Victoria. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Fil: Medrano, L. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Otras Psicologí

Commercial Serological Tests for the Diagnosis of Active Pulmonary and Extrapulmonary Tuberculosis: An Updated Systematic Review and Meta-Analysis

An up-to-date systematic review and meta-analysis by Karen Steingart and colleagues confirms that commercially available serological tests do not provide an accurate diagnosis of tuberculosis

Dynamic equivalence between atomic and colloidal liquids

We show that the kinetic-theoretical self-diffusion coefficient of an atomic fluid plays the same role as the short-time self-diffusion coefficient D_S in a colloidal liquid, in the sense that the dynamic properties of the former, at times much longer than the mean free time, and properly scaled with D_S, will indistinguishable from those of a colloidal liquid with the same interaction potential. One important consequence of such dynamic equivalence is that the ratio D_L/ D_S of the long-time to the short-time self-diffusion coefficients must then be the same for both, an atomic and a colloidal system characterized by the same inter-particle interactions. This naturally extends to atomic fluids a well-known dynamic criterion for freezing of colloidal liquids[Phys. Rev. Lett. 70, 1557 (1993)]. We corroborate these predictions by comparing molecular and Brownian dynamics simulations on (soft- and hard-sphere) model systems, representative of what we may refer to as the "hard-sphere" dynamic universality class

Geological Characterization, Mapping and Sampling of the Tailing Pond From Cerro El Toro, Region La Libertad-Perú

The present article shows the working methodology of the project field Development and validation of a clean technology for the integral treatment of neutralization of effluents and metallurgical tailings in the use of calcareous agents 1 Geological Characterization 2 Delimitation of the area of environmental influence for legal exploitation 3 Mapping 4 Sampling 5 Calculation of the volume of tailings 6 Study of the environmental impact of legal exploitation relationships It should be noted each one of these activities are important as part of the methodology of work in field which one are developed in the tailing Cerro El Toro which has been divided the aforementioned relationship into 73 sampling points grouped according to the relationships Salinas 1 Salinas 2 Salinas 3 Montoro and Melva whose volume has been determined through the software AutoCAD Civil which has determined that tailings have the following volume Salinas 1 1917 5 m3 Salinas 2 20331 48 m3 Salinas 3 18375 m3 Montoro 668 56 m3 y Melva 27945 5 m3 whose volume allowed the obtention of a representative sample of the tailing for been studied of their Environmental Quality of tailing which gives through the geochemical characterization analysis with the purpose of determining the Real Impact of the pollution of tailing in the mining communities of Shiracmaca and Coigobamb

The IgA Isotype of Anti-β2 Glycoprotein I Antibodies Recognizes Epitopes in Domains 3, 4, and 5 That Are Located in a Lateral Zone of the Molecule (L-Shaped)

Background: Antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy morbidity with presence of anti-phospholipid antibodies (aPL). The APS classification criteria only consider the aPL of IgG/IgM isotype, however testing of aPL of IgA isotype is recommended when APS is suspected and consensus aPL are negative. IgA anti-βeta-2 glycoprotein-I (B2GP1) has been clearly related with occurrence of thrombotic events. Antibodies anti-B2GP1 of IgG/M isotypes recognize an epitope in Domain 1 (R39-G43), the epitopes that recognize IgA anti-B2GP1 antibodies are not well-identified.Aim: To determine the zones of B2GP1 recognized by antibodies of IgA isotype from patients with APS symptomatology and positive for IgA anti-B2GP1.Methods: IgA antibodies to Domain-1(D1) and Domain-4/5(D4/5) of B2GP1 (ELISA) and epitope mapping on oligopeptide arrays of B2GP1 were evaluated in sera from a group of 93 patients with at least one thrombotic and with isolated positivity for IgA anti-B2GP1 antibodies (negative for other aPL).Results: A total of 47 patients (50.5%) were positive for anti-D4/5 and 23(25%) were positive for anti-D1. When peptide arrays were analyzed, three zones of B2GP1 reactivity were identified for more than 50% of patients. The center of these zones corresponds to amino acids 140(D3), 204(D4), and 264(D5). The peptides recognized on D3 and D4 contain amino acid sequences sharing high homology with proteins of microorganism that were previously related with a possible APS infectious etiology. In the three-dimensional structure of B2GP1, the three peptides, as the R39-G43 epitope, are located on the right side of the molecule (L-shape). The left side (J-shape) does not bind the antibodies.Conclusions: Patients with thrombotic APS clinical-criteria, and isolated IgA anti-B2GP1 positivity appear to preferentially bind, not to the D1 or D4/5 domains of B2GP1, but rather to three sites in D3, D4, and D5. The sites on D3 and D4 were previously described as the target identified by human monoclonal antibodies derived from patients that were capable of inducing APS in animal models. The localization of these epitopes opens a new route to explore to increase understanding of the patholophysiology of the APS and to propose new alternatives and therapeutic targets

Caracterización anatómica foliar de Lonchocarpus lilloi (Fabaceae, Papilionoideae)

Fernández Dattoli, Laura F.; Loto, Dante E.; Flores, Jorge R.; Luque, Catalina A.; Debes, Mario A.; Albornoz, Patricia L.; Arias, Marta E. 2011. “Caracterización anatómica foliar de Lonchocarpus lilloi (Fabaceae, Papilionoideae)”. Lilloa 48 (2). Lonchocarpus lilloi es un árbol endémico de Salta y Jujuy que habita entre 350 y 500 msnm. Mide de 10– 30 m de altura, con hojas compuestas de 4 a 6 folíolos opuestos y un folíolo terminal. El objetivo fue estudiar la anatomía foliar de esta especie. Se utilizó material fresco coleccionado en el Jardín Botánico de Fundación Miguel Lillo y en la Reserva Experimental Horco Molle y se aplicaron técnicas anatómicas convencionales. Los resultados mostraron que el folíolo es entero, simétrico, ovado y de venación pinnada. Estomas de distintos tipos: paracítico, hemiparacítico, anomocítico y anfiparacítico, en la epidermis abaxial; se observaron tricomas simples y glandulares. Pecíolo subcircular con estomas actinocíticos y tricomas simples. Los distintos tipos de estomas observados en la epidermis de lámina y pecíolo son caracteres no citados antes para esta especie. Se observaron canales esquizógenos y cristales prismáticos solitarios en lámina y pecíolo. Los caracteres diagnósticos para la identificación foliar de L. lilloi son: pulvínulo, domacio, lámina hipostomática, tipos de estomas, tricomas, cristales, estelas, venación, canales esquizógenos, conductos secretores y tubos laticíferos articulados

Overexpression of wild type RRAS2, without oncogenic mutations, drives chronic lymphocytic leukemia

[Background]: Chronic lymphocytic leukemia (CLL) is the most frequent, and still incurable, form of leukemia in the Western World. It is widely accepted that cancer results from an evolutionary process shaped by the acquisition of driver mutations which confer selective growth advantage to cells that harbor them. Clear examples are missense mutations in classic RAS genes (KRAS, HRAS and NRAS) that underlie the development of approximately 13% of human cancers. Although autonomous B cell antigen receptor (BCR) signaling is involved and mutations in many tumor suppressor genes and oncogenes have been identified, an oncogenic driver gene has not still been identified for CLL. [Methods]: Conditional knock-in mice were generated to overexpress wild type RRAS2 and prove its driver role. RT-qPCR analysis of a human CLL sample cohort was carried out to measure RRAS2 transcriptional expression. Sanger DNA sequencing was used to identify a SNP in the 3’UTR region of RRAS2 in human CLL samples. RNAseq of murine CLL was carried out to identify activated pathways, molecular mechanisms and to pinpoint somatic mutations accompanying RRAS2 overexpression. Flow cytometry was used for phenotypic characterization and shRNA techniques to knockdown RRAS2 expression in human CLL. [Results]: RRAS2 mRNA is found overexpressed in its wild type form in 82% of the human CLL samples analyzed (n = 178, mean and median = 5-fold) as well as in the explored metadata. A single nucleotide polymorphism (rs8570) in the 3’UTR of the RRAS2 mRNA has been identified in CLL patients, linking higher expression of RRAS2 with more aggressive disease. Deliberate overexpression of wild type RRAS2 in mice, but not an oncogenic Q72L mutation in the coding sequence, provokes the development of CLL. Overexpression of wild type RRAS2 in mice is accompanied by a strong convergent selection of somatic mutations in genes that have been identified in human CLL. R-RAS2 protein is physically bound to the BCR and mediates BCR signals in CLL. [Conclusions]: The results indicate that overexpression of wild type RRAS2 is behind the development of CLL.This work was supported by grants from the Spanish Association against Cancer (GC16173472GARC), PID2019-104935RB-I00 from the ‘Comision Interministerial de Ciencia y Tecnología’, the ‘Fundación Ramón Areces’, and by the European Research Council ERC 2013-Advanced Grant 334763 “NOVARIPP”, Instituto de Salud Carlos III (ISCIII) (CIBERONC – groups CB16/12/00233, CB16/12/00351), the Health Council of the Junta de Castilla y León (GRS 2036/A/19) and private Gilead (GLD15/00348). Juan de la Cierva (FJCI-2016-28756)