The Pierre Auger Observatory is the largest facility in the world to study ultra-high-energy cosmic rays. It has a hybrid detection technique that combines the observation of the longitudinal ...development of extensive air showers and the measurement of their particles at the ground. This capability has opened the possibility to probe hadronic interactions taking place at energies well beyond those accessible by human-made accelerators. In this report, we present a selection of the latest results on hadronic interactions with measurements from the Pierre Auger Observatory. These data span over three decades in energy, showing the tension between data from the muon component of air showers and predictions based on the most updated hadronic interaction models.
The work investigates a small full-scale wastewater treatment system comprised by the following units in series: UASB reactor, three polishing ponds and one coarse rock filter. The overall ...performance of the system is analyzed based on three years of monitoring using physical-chemical and biological parameters. Good organic matter, suspended solids and ammonia removal is achieved, together with excellent coliform removal (5.70 log units). Mean effluent concentrations of the main parameters are: BOD: 39 mg/L; COD: 109 mg/L; SS = 41 mg/L; ammonia: 10 mg/L; E. coli: 540 MPN/100 mL, indicating compliance with many regulations for effluent discharge and reuse. Main algal classes found in the ponds and final effluent were chlorophyta and euglenophyta. The system is completely unmechanized and has a relatively small total hydraulic retention time (less than 13 days), compared with most natural treatment processes. No sludge removal from the ponds and filter has been necessary so far.
El género Plectranthus L'Hér. (Familia Lamiaceae) posee alrededor de 300 especies, distribuidas en regiones cálidas y tropicales del mundo. Algunos representantes se destacan por los aceites ...esenciales presentes en hojas, tallos y brotes, de uso medicinal. Citogenéticamente, se reportó previamente un x=8 para el género. El objetivo de este trabajo es informar los avances citogenéticos de tres especies: Plectranthus madagascariensis (Pers.) Benth, con dos formas morfológicas marcadas: una de hoja chica y otra de hoja grande; Plectranthus verticillatus (L.f.) Druce y Plectranthus barbatus Andrews; su relación con grado de ploidía y forma de difusión. Se trabajó con colecciones de Tucumán, mantenidas por los autores de este trabajo. Para lograr las placas de mitosis y de meiosis se usaron meristemas radiculares y flores jóvenes, con técnicas convencionales. Los resultados determinaron para P. verticillatus, P. barbatus y P. madagascariensis forma hoja chica, un 2n=32, mientras que P. madagascariensis forma hoja grande, un 2n=48. El tamaño cromosómico es pequeño, variando de 1,5 a 2,5 µ. Considerando el número básico de x=8, P. verticillatus, P. barbatus y P. madagascariensis forma hoja chica son tetraploides, mientras que P. madagascariensis forma hoja grande, hexaploide. Las meiosis fueron irregulares en todos los casos, con escasa formación de semillas fértiles, por lo que se recurre a la multiplicación vegetativa para su propagación, asegurando así la provisión de material con uniformidad genética para su cultivo.
UASB reactors followed by polishing ponds comprise simple and economic wastewater treatment systems, capable of reaching very high removal efficiencies of pathogenic organisms, leading to the ...potential use of the effluent for unrestricted irrigation. However, for other types of reuse (urban and industrial), ponds are limited in the sense of producing effluents with high suspended solids (algae) concentrations. The work investigates a system with coarse rock filters for polishing the pond effluent. The overall performance of the system is analyzed, together with the potential for different types of reuse. The excellent results obtained (mean effluent concentrations: BOD: 27 mg/L; SS: 26 mg/L; E. coli: 450 MPN/100 mL) indicate the possibility of unrestricted use of the effluent for agriculture and restricted urban and industrial uses, according to WHO and USEPA.
A system comprising a UASB reactor, shallow polishing ponds and shallow coarse filters, treating actual wastewater from the city of Belo Horizonte, Brazil, has been evaluated. The main focus of the ...research was to compare grain sizes and hydraulic loading rates in the coarse filters. Two filters operating in parallel were investigated, with the following grain sizes: Filter 1: 3 to 10 cm; Filter 2: 8 to 20 cm. Two hydraulic loading rates were tested: 0.5 and 1.0 m3/m3.d. The filter with the lower rock size had a better performance than the filter with the larger rock size in the removal of SS and, as a consequence, BOD and COD. A better performance was obtained with the hydraulic loading rate of 0.5 m3/m3.d, as compared to the rate of 1.0 m3/m3.d. The effluent quality during the period with the lower loading rate was very good for discharge into water bodies or for agricultural reuse (median effluent concentrations from Filter 1: BOD: 20 mg/L; COD: 106 mg/L; SS: 28 mg/L; E. coli: 528 MPN/100 mL).
The Pierre Auger Observatory is the largest facility in the world to study ultra-high-energy cosmic rays. It has a hybrid detection technique that combines the observation of the longitudinal ...development of extensive air showers and the measurement of their particles at the ground. This capability has opened the possibility to probe hadronic interactions taking place at energies well beyond those accessible by human-made accelerators. In this report, we present a selection of the latest results on hadronic interactions with measurements from the Pierre Auger Observatory. These data span over three decades in energy, showing the tension between data from the muon component of air showers and predictions based on the most updated hadronic interaction models.
Between 1985 and 1987, examinations for human immune deficiency virus (HIV) antibody were done on 25,392 prostitutes working in 64 cities throughout the Philippines. The country-wide seropositivity ...rate among prostitutes based on this sample was 0.8/1,000. Of the HIV cases, 85% were working in just two cities whose prostitute populations comprised 50% of the total sample. The average incidence rate for the same two cities after 1 year was 2.3/1,000. HIV antibody-positive women were enrolled in a case-control study to determine demographic and epidemiologic risk factors. This study involving 34 HIV-positive prostitutes and 61 randomly selected negative control prostitutes did not reveal any risk factors related to sexual or other types of behavior. A history of genital warts, a history of abnormal vaginal discharge, and cytomegalovirus antibody were significantly more frequent in the HIV-positive cases than in the controls; however, by logistic regression analysis, only an abnormal vaginal discharge was independently associated with HIV infection. Absence of any evidence of transmission by blood transfusion or i.v. drug abuse suggests that HIV was introduced by the heterosexual route.
El boldo brasilero (Plectranthus barbatus Andrews) es una planta originaria de la India y naturalizada en algunas regiones de Argentina. Se usa en medicina popular, farmacología y como ornamental. El ...objetivo de este trabajo fue caracterizar a P. barbatus mediante estudios citogenéticos para contribuir al conocimiento biológico y genético de la especie. El material se colectó en San Pedro de Colalao, provincia de Tucumán, Argentina. Para los estudios citológicos se utilizaron meristemas radiculares (mitosis) e inflorescencias (meiosis). Para la determinación de viabilidad de polen en células madres de polen, se empleó la técnica de coloración de Azul de Algodón en Lactofenol. El número cromosómico en mitosis es de 2n=32. En meiosis, se observaron monovalentes y trivalentes en Metafase I, rezagados en Anafase I y en Telofase I. En los preparados de polen se encontró un 70 % de granos anormales y un 30 % de normales. Según los números básicos de x = 6, 7 u 8 citados para el género, se deduce que se trata de un tetraploide con meiosis irregular (autotetraploide). La falla en la formación de semillas explica su forma más frecuente de propagación: la multiplicación vegetativa. Sería conveniente tener en cuenta este tipo de multiplicación para mantener un genotipo deseado, logrando uniformidad genética en la población, a la vez que se logra rapidez en la obtención de una gran cantidad de plantas