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Resumen Objetivo: determinar la seroprevalencia de anticuerpos contra SARS-CoV-2. Metodología: para ello, entre el 21 de noviembre y el 12 de diciembre del año 2020, se desarrolló un estudio transversal en 1182 muestras de residentes de un municipio bonaerense en la Provincia de Buenos Aires, Argentina. Se midió IgG por ELISA en muestras obtenidas vía digitopunción. Resultados: la prevalencia general fue del 12,2 % (n = 144; IC95 %: 10,3 - 14,0) con un cociente 1:3,8 entre la incidencia acumulada y la observación en nuestro estudio; en mujeres fue del 13,0 % (IC95 %: 10,2 - 15,7) y en hombres, del 10,5 % (IC95 %: 7,6 - 13,3) (p = 0.21). Las prevalencias en grupos etarios fueron las siguientes: 18 a 30 años, del 17,8 % (IC95 %: 12,0 - 23,6); 31 a 60 años, del 12,2 % (IC95 %: 9,3 - 15,1) y 61 años o más, del 9.9 % (IC95 %: 6.9 - 13.9) (p = 0.02). Las prevalencias según los terciles socioeconómicos (por Necesidades Básicas Insatisfechas) fueron para el Tercil I (mejor tercil): 7,7 % (IC95 %: 4,7 - 10,7); el Tercil II: 12.5 % (IC95 %: 8,7 - 16,4); y el Tercil III: 15,2 % (IC95 %: 11,6 - 18,8) (p = 0.002). Conclusiones: también hubo diferencias entre las localidades de dicho municipio y entre variables clínicas autorrefenciadas. Se detectaron 12 muestras positivas para IgM: el 1 % del total y el 8,3 % respecto de los casos IgG-positivos. Los estudios de seroprevalencia resultan útiles y podrían contribuir a modelizaciones matemáticas más ajustadas.
Abstract Objective: determine the prevalence of anti-bodies against SARS-CoV-2. Method: between November twenty-one and December twelve of two thousand and twenty year, a cross-sectional study was carried out in 1182 samples from residents of a Buenos Aires town in the Province of Buenos Aires, Argentina. IgG was measured by ELISA in samples obtained by acupressure. Results: the global prevalence was 12.2 % (n = 144; 95 % CI: 10.3 - 14.0) with a ratio of 1: 3.8, between cumulative incidence and observational values. Prevalence in women and men were 13.0 % (95 % CI: 10.2 - 15.7) and 10.5 % (95 % CI: 7.6 - 13.3), respectively (p = 0.21). By age, the observed values were: 17.8 % (95 % CI: 12.0 - 23.6) in 18 and 30 years old group; 12.2 % (95 % CI: 9.3 - 15.1) in 31 to 60 years old group, 9.9 % (95 % CI: 6.9 - 13.9) in people over 61 years old (p = 0.02). According the socioeconomic tertiles (for Unsatisfied Basic Needs) the prevalence values were 7.7 % (95 % CI: 4.7 - 10.7) for Tertile I (best tertile), 12.5 % (95 % CI: 8.7 - 16.4) for Tertile II, and 15.2 % (95 % CI: 11.6 - 18.8) for Tertile III (p = 0.002). Conclusion: there were also differences between the neighbourhoods and between self-reported clinical variables. Specific IgM antibodies were detected in 12 samples, which represented 1% of the total. Seroprevalence studies provide useful information that can be apllied to fit modeling.
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We study families of open chaotic maps that classically share the same asymptotic properties--forward and backward trapped sets, repeller dimensions, and escape rate--but differ in their short time behavior. When these maps are quantized we find that the fine details of the distribution of resonances and the corresponding eigenfunctions are sensitive to the initial shape and size of the openings. We study phase space localization of the resonances with respect to the repeller and find strong delocalization effects when the area of the openings is smaller than â.
Assuntos
Modelos Teóricos , Oscilometria/métodos , Teoria Quântica , Simulação por ComputadorRESUMO
We study relevant features of the spectrum of the quantum open baker map. The opening consists of a cut along the momentum p direction of the 2-torus phase space, modeling an open chaotic cavity. We study briefly the classical forward trapped set and analyze the corresponding quantum nonunitary evolution operator. The distribution of eigenvalues depends strongly on the location of the escape region with respect to the central discontinuity of this map. This introduces new ingredients to the association among the classical escape and quantum decay rates. Finally, we could verify that the validity of the fractal Weyl law holds in all cases.
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Salivary glands are a good model to investigate the relationship between cell secretion and glandular structure. Most studies of this organ deal with mammals, but we are interested in a morphofunctional characterization of these glands in poultry in relation with particular feeding habits. For this purpose, conventional and lectin histochemical methods as well as ultrastructural methods have been applied to the chicken lateral and medial palatine salivary glands. It was found that periodic acid-Schiff (PAS)-positive, alcianophilic, and metachromatic or orthochromatic cells were present with a more homogeneous distribution pattern in lateral glands than in medial palatine glands. Lectin staining depended on the lectin type that was applied, but also on the glandular part both in lateral and medial glands. Ultrastructural studies showed cytoplasmic membranous structures with a scattered granular or filamentous content depending on the secretory cell. In conclusion, morphofunctional characteristics of salivary glands of chicken suggest that their products are involved in lubrication and humidification of food ingested, and probably in protection of the oral surface, as has been previously described for other animals showing similar histochemical staining patterns.