On extending actions of groups

Problems of dense and closed extension of actions of compact transformation groups are solved. The method developed in the paper is applied to problems of extension of equivariant maps and of construction of equivariant compactifications

Graft-Copolymerization of Acrylate Monomers onto Chitosan Induced by Gamma Radiation: Amphiphilic Polymers and Their Behavior at The Air-Water Interface

Graft polymerization induced by ionizing radiation is a powerful tool in materials science to modifying the physical properties of polymers. Chitosan is a biocompatible, biodegradable, antibacterial, and highly hydrophilic polysaccharide. In this work, we report the obtaining of amphiphilic polymers through graft polymerization of acrylic monomers (methyl acrylate, t-butyl acrylate, and hexyl acrylate) onto chitosan. The polymerization reaction was carried out by simultaneous irradiation of monomers and chitosan using a gamma radiation source of 60Co. The formation of Langmuir films of amphiphilic polymers was studied at the air-water interface through surface pressure versus main molecular area isotherms (Π-A) and hysteresis cycles of compression and decompression. Finally, it was analyzed the transferring of Langmuir films towards solid substrates to obtaining Langmuir-Blodgett films with potential application as an antibacterial coating. The microstructure of the Langmuir-Blodgett films was characterized by AFM microscopy observing a regular topography with roughness ranging between 0.53 and 0.6 μm

Xenoestrogens released from lacquer coatings in food cans

We present data showing that some foods preserved in lacquer-coated cans and the liquid in them may acquire estrogenic activity. Hormonal activity was measured using the E-screen bioassay. The biological activity of vegetables packed in cans was a result of plastic monomers used in manufacturing the containers. The plastic monomer bisphenol-A, identified by mass spectrometry, was found as a contaminant not only in the liquid of the preserved vegetables but also in water autoclaved in the cans. The amount of bisphenol-A in the extracts accounted for all the hormonal activity measured. Although the presence of other xenoestrogens cannot be ruled out, it is apparent that all estrogenic activity in these cans was due to bisphenol-A leached from the lacquer coating. The use of plastic in food-packaging materials may require closer scrutiny to determine whether epoxy resins and polycarbonates contribute to human exposure to xenoestrogens.This work was supported by grant 94/1551 from the Fondo de Investigaciones Sanitarias (FIS), Spanish Ministry of Health

Impacto de las Abejas (Apis mellifera L.) Como Agentes Polinizadores en el Rendimiento del Cultivo de Zucchini (Cucurbita pepo L.) en el Canton Riobamba, Provincia de Chimborazo

The impact of bees (Apis mellifera L.) as pollinators in the yield of the zucchini (Cucurbita pepo L.) crop in the Riobamba canton, Chimborazo province, was evaluated using a Randomized Complete Block Design (RCBD). This was done using three treatments and three repetitions. The treatments evaluated were: the zucchini cultivation inside the micro tunnel covered with entomological mesh with the presence of bees, the zucchini cultivation inside the micro tunnel covered with anti aphids mesh without the presence of bees, and the open field zucchini cultivation. The evaluated parameters were number of days to the appearance of the fruits, percentage of fertilized and unfertilized flowers, number of fruits per plant, size of fruits, diameter of fruits, weight of fruit, and yield in kg / ha per treatment. The best results achieved in most parametersthat were evaluated such as the percentage of flowering, number of fruits per plant, size of fruit in cm, diameter of fruit in cm, weight of the fruit in grams, yield in kg/ha by treatment, and economic analysis were obtained with the presence of bees (Apis mellifera L.) as pollinating agents in the tunnel. This is in addition to meshes during the flowering stage of the zucchini crop, with an average yield of 14.9 tn/ha.Se evaluó el impacto de las abejas (Apis mellifera L.) como agentes polinizadores en el rendimiento del cultivo de zucchini (Cucurbita pepo L.) en el cantòn Riobamba, provincia de Chimborazo. Para llevar a cabo esta evaluación se utilizó un diseño de bloques completos a azar (DBCA), con tres tratamientos y tres repeticiones. Los tratamientos evaluados fueron: El cultivo de zucchini dentro del micro túnel cubierto con malla entomológica con presencia de abejas, el cultivo de zucchini dentro del micro túnel cubierto con malla antiáfidossin presencia de abejas y el cultivo de zucchini a campo abierto. Los parámetros evaluados fueron número de días transcurridos después de la aparición de los frutos, porcentaje de flores fecundadas y no fecundadas, número de frutos por planta, tamaño de frutos, diámetro de frutos, peso del fruto y rendimiento en kg/ha por tratamiento. Los mejores resultados alcanzados en la mayoría de los parámetros evaluados como el porcentaje de floración, número de frutos por planta, tamaño de fruto en (cm), diámetro de fruto en (cm), peso del fruto en gramos, rendimiento en kg/ha por tratamiento y análisis económico, se obtuvieron con la presencia de las abejas (Apis mellifera L.) como agentes polinizadores en el túnel con mallas durante la etapa de floración del cultivo de zucchini, con un rendimiento en promedio de 14.9 tn/ha

Identificação de parvovírus suíno em javalis a partir do sequenciamento parcial do gene VP-2

Este estudo descreve a detecção e a identificação de DNA de parvovírus suíno (PVS) em amostras de órgãos de dois javalis, por PCR e sequenciamento direcionado ao gene VP-2. Pools de órgãos (baço, rins, fígado, linfonodos e tonsila) de três javalis adultos e assintomáticos de Paraguaçu Paulista, SP, criados com propósitos comerciais, foram submetidos à detecção de PVS, resultando em duas amostras positivas após reações de nested-PCR direcionadas aos genes NS-1 e VP-2. Os fragmentos parciais de VP-2 foram sequenciados e comparados a sequências homólogas de cepas NADL-2 e Kresse, demonstrando identidade nucleotídica de 100%. Com relação a 29 cepas de PVS previamente isoladas no Brasil, o grau de identidade nucleotídica variou de 99 a 100% (uma a três substituições de nucleotídeos). Estes resultados demonstram, pela primeira vez, a detecção direta por PCR de parvovírus suíno em javalis, confirmada por análise de sequenciamento genétic

A study of the etapipi channel produced in central pp interactions at 450 GeV/c

The reaction pp -> pf (eta pi pi) ps has been studied at 450 GeV/c. There is clear evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870). In addition, there is evidence for an a0(980)pi$ decay mode of both resonances and an f2(1270)eta decay mode of the eta2(1870). No evidence is found for a JPC = 2++ a2(1320)pi wave.Comment: 15 pages, Latex, 4 Figures Branching ratio a2pi /f2 eta correcte