41 research outputs found

    Dynamic equivalence between atomic and colloidal liquids

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    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

    De novo assembly and transcriptome characterization of the freshwater prawn Palaemonetes argentinus: Implications for a detoxification response

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    Palaemonetes argentinus, an abundant freshwater prawn species in the northern and central region of Argentina, has been used as a bioindicator of environmental pollutants as it displays a very high sensitivity to pollutants exposure. Despite their extraordinary ecological relevance, a lack of genomic information has hindered a more thorough understanding of the molecular mechanisms potentially involved in detoxification processes of this species. Thus, transcriptomic profiling studies represent a promising approach to overcome the limitations imposed by the lack of extensive genomic resources for P. argentinus, and may improve the understanding of its physiological and molecular response triggered by pollutants. This work represents the first comprehensive transcriptome-based characterization of the non-model species P. argentinus to generate functional genomic annotations and provides valuable resources for future genetic studies. Trinity de novo assembly consisted of 24,738 transcripts with high representation of detoxification (phase I and II), anti-oxidation, osmoregulation pathways and DNA replication and bioenergetics. This crustacean transcriptome provides valuable molecular information about detoxification and biochemical processes that could be applied as biomarkers in further ecotoxicology studies.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Limnología "Dr. Raúl A. Ringuelet

    La sociología de la salud y los paradigmas de investigación

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    El presente libro se deriva del trabajo colegiado de la investigación científica, que realizan maestro y alumnos de las diferentes sedes académicas, para así contribuir mas a la investigación y que de igual manera sea un complemento de estudio para la Licenciatura en Educación para la Salud y para la Maestría en Sociología de la SaludEl libro contiene diversas temáticas que muestran conocimientos, metodologías, técnicas, herramientas y lenguajes necesarios utilizados comúnmente en el área de las Ciencias Sociales y de la Salud, desde un enfoque multi y transdisciplinario para poder indagar los elementos que componen la diversidad, la multiculturalidad y el medio ambiente que gira en torno a los temas de salud y de los estilos de vida saludabl

    Ancient mitochondrial DNA provides high-resolution time scale of the peopling of the Americas

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    The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages

    Aportaciones a los estudios económico-administrativos. Reflexiones teóricas y evidencias empíricas

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    La economía y la administración están inmersas en el universo de las ciencias sociales, áreas del conocimiento que comprenden dominios diferentes, pero también convergen y se intersectan en un objeto de estudio: las organizacienones y sus agregados (industrias o sectores). Desde una perspectiva social, los estudios económico-administrativos informan sobre cómo hacer eficientes a las organizaciones y competitivos a los sectores con la finalidad de impactar positivamente en la justicia social (por ejemplo: mediante productos de mejor calidad a mejores precios). El auge de este tipo de estudios está extendido a fenómenos clave en el mundo de hoy, tales como: la ventaja competitiva, la innovación, la administración de la cadena de suministros y la administración verde, entre otros.El objetivo de este libro es difundir las aportaciones hechas a los estudios económico-administrativos, ya sea como reflexiones teóricas o a modo de evidencia empírica, pues la conjunción de varias ciencias ayuda a comprender fenómenos complejos mejor que una disciplina en forma aislada. Más que la homogeneidad de teorías o hegemonía de unas sobre otras, la investigación interdisciplinaria construye un acercamiento a la diversidad de puntos de vista: se buscan factores, métodos o lenguajes comunes alrededor de un objeto de estudio (Fernández, 2009; Martínez, 1997), llegándose a conformar una comunidad científica con antecedentes disciplinarios diferentes, pero con cierta unidad, relaciones y acciones recíprocas (Kuhn, 1995). Así, en este texto el objeto de estudio es el funcionamiento e interacción de las organizaciones, como integrantes de los sectores económicos, en los mercados locales y globales. La comunidad científica está conformada por investigadores y egresados del Doctorado en Ciencias Económico-Administrativas, el cual nace en 2006 en la Universidad Autónoma del Estado de México, a cargo de la Dependencia de Educación Superior (DES) Económico-Administrativa

    Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

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    Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

    Conocimiento etnoherpetológico de dos comunidades aledañas a la reserva estatal sierra de montenegro, Morelos, México

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    La fauna silvestre aporta a las comunidades campesinas de México satisfactores como carne, huevos o estructuras anatómicas para la elaboración de artesanías y servicios ambientales que garantizan su bienestar social. El objetivo del presente trabajo fue analizar el conocimiento etnoherpetológico en dos comunidades aledañas a la Reserva Estatal Sierra de Montenegro, Morelos. Se utilizaron técnicas etnozoológicas: entrevistas abiertas y se aplicaron 105 cuestionarios semi-estructurados a hombres y mujeres. Para la identificación de las especies se llevaron a cabo recorridos guiados con el apoyo de expertos naturalistas locales. Los informantes reconocen 32 especies herpetofaunísticas, de las cuales 15 (48%) presentan valor cultural y, de éstas, 9 (29%) tienen lossiguientes valores de uso: alimento, medicinal, ornamental y mascota. Las especies de anfibios más conocidas fueron el sapo (Rhinella marina) y la rana (Lithobates zweifeli), utilizados como medicina y alimento. Ya para los reptiles, la iguana negra (Ctenosaura pectinata) como alimento, medicina y mascota; la víbora de cascabel (Crotalus culminatus) como alimento, medicina, ornamento y mascota; y el tilcuate (Drymarchon melanurus) en relatos. Los habitantes poseen conocimiento acerca de anfibios y reptiles, reflejado en las formas de manejo y uso y en la manera en que los perciben, así como creencias, cuentos y relatos. Los habitantes identifican hábitos de las diferentes especies, así como aquellas venenosas y no venenosas. Los estudios etnoherpetológicos aportanelementos factibles de ser integrados a planes de manejo y conservación de la herpetofauna

    Molecular analysis and risk factors for Escherichia coli producing extended-spectrum β-lactamase bloodstream infection in hematological malignancies.

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    INTRODUCTION: Patients with hematologic malignancies have greater risk-factors for primary bloodstream infections (BSI). METHODS: From 2004-2009, we analyzed bacteremia caused by extended-spectrum beta-lactamase Escherichia coli (ESBL-EC) (n = 100) and we compared with bacteremia caused by cephalosporin-susceptible E. coli (n = 100) in patients with hematologic malignancies. OBJECTIVE: To assess the clinical features, risk factors, and outcome of ESBL-EC BSI in patients with hematologic malignancies, and to study the molecular epidemiology of ESBL-EC isolates. RESULTS: The main diagnosis was acute leukemia in 115 patients (57.5%). Death-related E. coli infection was significantly increased with ESBL-EC (34% vs. control group, 19%; p = 0.03). Treatment for BSI was considered appropriate in 64 patients with ESBL-EC (mean survival, 245 ± 345 days), and in 45 control patients this was 443 ± 613 (p = 0.03). In patients not receiving appropriate antimicrobial treatment, survival was significantly decreased in cases compared with controls (26 ± 122 vs. 276 ± 442; p = 0.001). Fifty six of the ESBL-EC isolates were characterized by molecular analysis: 47 (84%) expressed CTX-M-15, two (3.6%) SHV, and seven (12.5%) did not correspond to either of these two ESBL enzymes. No TLA-1 enzyme was detected. CONCLUSIONS: Patients who had been previously hospitalized and who received cephalosporins during the previous month, have an increased risk of ESBL-EC bacteremia. Mortality was significantly increased in patients with ESBL-EC BSI. A polyclonal trend was detected, which reflects non-cross transmission of multiresistant E.coli isolates

    Plasmid profile of representative clinical isolates and transconjugants.

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    <p>1. <i>E. coli</i> 50192 (154-, 68-, and 36-kb), 2. pUA21 (275 kb), 3. 835, 4. T835, 5. 836, 6. T836, 7. 837, 8. T837, 9. 839, 10. T839, 11. 840, 12. T840, 13. 843, 14. T843, 15. T850, 16. 850, 17. 6737, 18. T6737, 19. 844. </p
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