1,899 research outputs found
Colonização de raízes em soja co-inoculadas com Bradyrhizobium japonicum e Enterobacter agglomerans.
Avaliação da contaminação de alface (Lactuca sativa) por coliformes termotolerantes e Escherichia coli em sistemas de cultivo orgânico e convencional.
A alface (Lactuca sativa) é a hortaliça folhosa mais consumida no Brasil, sendo classificada como um importante alimento para a população por ser uma rica fonte de vitaminas. Em função das práticas adotadas, o seu cultivo pode ser orgânico ou convencional. No entanto, alface pode ser um veículo transmissor de microrganismos patogênicos ao homem, como coliformes termotolerantes e Escherichia coli, uma vez que se encontra em contato com esses contaminantes presentes freqüentemente no solo, na água, nos insumos naturais (cama de frango) propiciando o desenvolvimento e a sobrevivência dos mesmos. O objetivo deste trabalho foi avaliar quantitativamente, a presença de Coliformes termotolerantes e de E.coli em água de irrigação e de pré-lavagem, assim como, o produto alface não lavada e pré-lavada, cultivada sob cultivo orgânico e convencional, em relação a recomendação da ANVISA. As coletas foram realizadas em dez propriedades, cinco de cultivo orgânico e cinco de cultivo convencional, localizadas nas cidades de Ibiúna, Jaguariúna, Campinas e Morungaba - SP. Em laboratório, as amostras foram submetidas à análise de tubos múltiplos e série bioquímica e procedeu-se a avaliação pela técnica de contagem do Número Mais Provável. Os resultados mostraram um alto índice de coliformes termotolerantes e E. coli, na água de irrigação sendo um fator importante pela contaminação da alface, independente do sistema de cultivo. Todavia, o cultivo convencional apresentou índices de contaminação por esse microrganismos na água superiores ao do cultivo orgânico. No produto alface, a pré lavagem contribuiu para a redução da contaminação por coliformes termotolerantes e E. coli, que no entanto essa contaminação pelo primeiro foi mais alta em ambos os sistemas de cultivos. Além disso, outras práticas utilizadas nas propriedades como, a higiene pessoal, o uso de adubos compostados não adequados e a presença de animais nas áreas de cultivo são fontes de contaminação.Dissertação (Mestrado em Agroecologia e Desenvolvimento Rural) - Centro de Ciências Agrárias, UFSCar, Araras. Orientador: Pedro José Valarini, Embrapa Meio Ambiente
Grid services for the MAGIC experiment
Exploring signals from the outer space has become an observational science
under fast expansion. On the basis of its advanced technology the MAGIC
telescope is the natural building block for the first large scale ground based
high energy gamma-ray observatory. The low energy threshold for gamma-rays
together with different background sources leads to a considerable amount of
data. The analysis will be done in different institutes spread over Europe.
Therefore MAGIC offers the opportunity to use the Grid technology to setup a
distributed computational and data intensive analysis system with the nowadays
available technology. Benefits of Grid computing for the MAGIC telescope are
presented.Comment: 5 pages, 1 figures, to be published in the Proceedings of the 6th
International Symposium ''Frontiers of Fundamental and Computational
Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200
A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors
Gamma ray astronomy is now at the leading edge for studies related both to
fundamental physics and astrophysics. The sensitivity of gamma detectors is
limited by the huge amount of background, constituted by hadronic cosmic rays
(typically two to three orders of magnitude more than the signal) and by the
accidental background in the detectors. By using the information on the
temporal evolution of the Cherenkov light, the background can be reduced. We
will present here the results obtained within the MAGIC experiment using a new
technique for the reduction of the background. Particle showers produced by
gamma rays show a different temporal distribution with respect to showers
produced by hadrons; the background due to accidental counts shows no
dependence on time. Such novel strategy can increase the sensitivity of present
instruments.Comment: 4 pages, 3 figures, Proc. of the 9th Int. Syposium "Frontiers of
Fundamental and Computational Physics" (FFP9), (AIP, Melville, New York,
2008, in press
COVID-19 Vaccine Hesitancy in Italy: Predictors of Acceptance, Fence Sitting and Refusal of the COVID-19 Vaccination
Background: The hesitancy in taking the COVID-19 vaccine is a global challenge. The need to identify predictors of COVID-19 vaccine reluctance is critical. Our objectives were to evaluate sociodemographic, psychological, and behavioral factors, as well as attitudes and beliefs that influence COVID-19 vaccination hesitancy in the general population of Italy. Methods: A total of 2,015 people were assessed in two waves (March, April and May, 2021). Participants were divided into three groups: (1) individuals who accepted the vaccination (“accepters”); (2) individuals who refused the vaccination (“rejecters”); and (3) individuals who were uncertain about their attitudes toward the vaccination (“fence sitters”). Group comparisons were performed using ANOVA, the Kruskal-Wallis test and chi-square tests. The strength of the association between the groups and the participants' characteristics was analyzed using a series of multinomial logistic regression models with bootstrap internal validation (one for each factor). Results: The “fence sitters” group, when compared to the others, included individuals of younger age, lower educational level, and worsening economic situation in the previous 3 months. After controlling for sociodemographic factors, the following features emerged as the main risk factors for being “fence sitters” (compared with vaccine “accepters”): reporting lower levels of protective behaviors, trust in institutions and informational sources, frequency of use of informational sources, agreement with restrictions and higher conspirative mentality. Higher levels of COVID-19 perceived risk, trust in institutions and informational sources, frequency of use of informational sources, agreement with restrictions and protective behaviors were associated with a higher likelihood of becoming “fence sitters” rather than vaccine “rejecters.” Conclusions: The “fence sitters” profile revealed by this study is intriguing and should be the focus of public programmes aimed at improving adherence to the COVID-19 vaccination campaign
The MAGIC Experiment and Its First Results
With its diameter of 17m, the MAGIC telescope is the largest Cherenkov
detector for gamma ray astrophysics. It is sensitive to photons above an energy
of 30 GeV. MAGIC started operations in October 2003 and is currently taking
data. This report summarizes its main characteristics, its rst results and its
potential for physics.Comment: 6 pages, 3 figures, to be published in the Proceedings of the 6th
International Symposium ''Frontiers of Fundamental and Computational
Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200
Potencial de bactérias endofíticas na produção de enzimas hidrolíticas e promotoras de emergência de plântulas de soja.
INFN Camera demonstrator for the Cherenkov Telescope Array
The Cherenkov Telescope Array is a world-wide project for a new generation of
ground-based Cherenkov telescopes of the Imaging class with the aim of
exploring the highest energy region of the electromagnetic spectrum. With two
planned arrays, one for each hemisphere, it will guarantee a good sky coverage
in the energy range from a few tens of GeV to hundreds of TeV, with improved
angular resolution and a sensitivity in the TeV energy region better by one
order of magnitude than the currently operating arrays. In order to cover this
wide energy range, three different telescope types are envisaged, with
different mirror sizes and focal plane features. In particular, for the highest
energies a possible design is a dual-mirror Schwarzschild-Couder optical
scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based
camera is being proposed as a solution to match the dimensions of the pixel
(angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made
by 9 Photo Sensor Modules (PSMs, 64 pixels each, with total coverage 1/4 of the
focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near
UltraViolet High Fill factor SiPMs and Front-End Electronics (FEE) based on a
Target 7 ASIC, a 16 channels fast sampler (up to 2GS/s) with deep buffer,
self-trigger and on-demand digitization capabilities specifically developed for
this purpose. The pixel dimensions of mm lead to a very compact
design with challenging problems of thermal dissipation. A modular structure,
made by copper frames hosting one PSM and the corresponding FEE, has been
conceived, with a water cooling system to keep the required working
temperature. The actual design, the adopted technical solutions and the
achieved results for this demonstrator are presented and discussed.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Seleção de bactérias endofíticas e epífiticas de soja com potencial de controle biológico de Rhizoctonia solani.
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