7,842 research outputs found
Avaliação de longo prazo do efeito de eliminação de Apple stem grooving virus por quimioterapia em macieira cv. Royal Gala.
Neste estudo, plantas da cv. Royal Gala foram submetidas a PEV (procedimento de eliminação de vírus) por quimioterapia in vitro com ribavirina por 60 dias (tratamento 0 (controle negativo), sem ribavirina; 1, 1 pg/ml; 2, 5 pg/ml; 3, 10 pg/ml de ribavirina), com 4 repetições independentes, aclimatadas e avaliadas quanto à eficácia do PEV por RT-PCR convencional, imediatamente após o tratamento (maio-julho/2010) e após mais 1 ano (julho/2011). As plantas sobreviventes dos experimentos acima, quatro anos após o tratamento inicial, foram reavaliadas quanto à presença de ASGV (Apple stem grooving virus) por RT-PCR convencional e RT-PCR em tempo real com Sybr Green l
Non-lethal effects of N-acetylcysteine on xylella fastidiosa strain De Donno biofilm formation and detachment
This study investigated in-vitro the non-lethal eects of N-acetylcysteine (NAC) on Xylella fastidiosa subspecies pauca strain De Donno (Xf-DD) biofilm. This strain was isolated fromthe olive trees aected by the olive quick decline syndrome in southern Italy. Xf-DD was first exposed to non-lethal concentrations of NAC from 0.05 to 1000 M. Cell surface adhesion was dramatically reduced at 500 M NAC (47%), hence, this concentration was selected for investigating the eects of pre-, postand co-treatments on biofilm physiology and structural development, oxidative homeostasis, and biofilm detachment. Even though 500 MNAC reduced bacterial attachment to surfaces, compared to the control samples, it promoted Xf-DD biofilm formation by increasing: (i) biofilm biomass by up to 78% in the co-treatment, (ii) matrix polysaccharides production by up to 72% in the pre-treatment, and (iii) reactive oxygen species levels by 3.5-fold in the co-treatment. Xf-DD biofilm detachment without and with NAC was also investigated. The NAC treatment did not increase biofilm detachment, compared to the control samples. All these findings suggested that, at 500 M, NAC diversified the phenotypes in Xf-DD biofilm, promoting biofilm formation (hyper-biofilm-forming phenotype) and discouraging biofilm detachment (hyper-attachment phenotype), while increasing oxidative stress level in the biofilm
Imaging the first light: experimental challenges and future perspectives in the observation of the Cosmic Microwave Background Anisotropy
Measurements of the cosmic microwave background (CMB) allow high precision
observation of the Last Scattering Surface at redshift 1100. After the
success of the NASA satellite COBE, that in 1992 provided the first detection
of the CMB anisotropy, results from many ground-based and balloon-borne
experiments have showed a remarkable consistency between different results and
provided quantitative estimates of fundamental cosmological properties. During
2003 the team of the NASA WMAP satellite has released the first improved
full-sky maps of the CMB since COBE, leading to a deeper insight into the
origin and evolution of the Universe. The ESA satellite Planck, scheduled for
launch in 2007, is designed to provide the ultimate measurement of the CMB
temperature anisotropy over the full sky, with an accuracy that will be limited
only by astrophysical foregrounds, and robust detection of polarisation
anisotropy. In this paper we review the experimental challenges in high
precision CMB experiments and discuss the future perspectives opened by second
and third generation space missions like WMAP and Planck.Comment: To be published in "Recent Research Developments in Astronomy &
Astrophysics Astrophysiscs" - Vol I
Integrating Remote Sensing, GIS and Prediction Models to Monitor the Deforestation and Erosion in Peten Reserve, Guatemala
International audienceThis contribution provides a strategy for studying and modelling the deforestation and soil deterioration in the natural forest reserve of Peten, Guatemala, using a poor spatial database. A Multispectral Image Processing of Spot and TM Landsat data permits to understand the behaviour of the past land cover dynamics; a multi-temporal analysis of Normalized Difference Vegetation and Hydric Stress index, most informative RGB (according to statistical criteria) and Principal Components, points out the importance and the direction of environmental impacts. We gain from the Remote Sensing images new environmental criteria (distance from roads, oil pipe-line, DEM, etc.) which influence the spatial allocation of predicted land cover probabilities. We are comparing the results of different prospective approaches (Markov Chains, Multi Criteria Evaluation and Cellular Automata; Neural Networks) analysing the residues for improving the final model of future deforestation risk
Cardiac output: A central issue in patients with respiratory extracorporeal support
The iLA-activve® Novalung is a new extracorporeal device specifically designed for lung support in patients with hypercapnic and/or hypoxemic respiratory failure. To date, only low-flow applications for decompensated hypercapnic chronic obstructive pulmonary disease have been reported in the literature. Here, we briefly report three cases of iLA-activve use in patients with hypercapnic-hypoxemic acute lung failure assisted with mid-flow (up to 2.4 L/min) and different single/double venous cannulation. The main findings of our small case series were: firstly, extracorporeal blood flows over 2.0 L/min across the membrane provided clinically satisfying decarboxylation and improved oxygenation; secondly, the ratio between blood flow through the membrane and the patient's cardiac output (CO) was a major determinant for the oxygen increase. The latter could, therefore, be a useful indicator for understanding performance in the complex and multifactorial evaluation of patients with extracorporeal veno-venous lung support
Modelagem da ocorrência e da quantidade de chuva em Piracicaba
A model to describe the daily rainfall in Piracicaba, SP, Brazil, is proposed to relate the ocurrence of rainy and rainless days, and in terms of their amount. Both, the occurrence of days without and with rain, in tems of their sequences of 31 days following a given date, can well be represented by the truncated negative binomial distribution function with its parameters adjusted to a periodic funtion with the first two harmonics. The amount of rain was well described by the gamma distribution; the shape parameter (gamma) remaining constant but the scale parameter (beta) had a periodic variation which could be represented by a periodic function with two harmonics. Analysis of the data shows that the rainfall series for Piracicaba (1917 to 1944 and 1945 to 1989) can be considered omogeneus, even though the weather station had been moved from its original location.É proposto um modelo para descrever chuva diária de Piracicaba-SP em termos da sua ocorrência e da quantidade. Ambos, a ocorrência de dias com e sem chuva, quando considerados como seqüências de 31 dias a partir de determinada data, puderam ser bem representadas pela distribuição binomial negativa truncada, com parâmetros ajustados a uma função periódica com dois harmônicos. A quantidade de chuva nos dias com chuva, foi adequadamente ajustada à distribuição gama com o seu parâmetro de forma (gama) permanecendo constante mas o parâmetro de escala (beta) apresentando variação periódica que pode ser descrita por uma função com dois harmônicos. A análise dos dados mostrou que as séries de chuva de 1917 a 1944 e de 1945 a 1989, resultantes da mudança dos postos de observação, são homogêneas
Planck-LFI radiometers tuning
"This paper is part of the Prelaunch status LFI papers published on JINST:
http://www.iop.org/EJ/journal/-page=extra.proc5/jinst"
This paper describes the Planck Low Frequency Instrument tuning activities
performed through the ground test campaigns, from Unit to Satellite Levels.
Tuning is key to achieve the best possible instrument performance and tuning
parameters strongly depend on thermal and electrical conditions. For this
reason tuning has been repeated several times during ground tests and it has
been repeated in flight before starting nominal operations. The paper discusses
the tuning philosophy, the activities and the obtained results, highlighting
developments and changes occurred during test campaigns. The paper concludes
with an overview of tuning performed during the satellite cryogenic test
campaign (Summer 2008) and of the plans for the just started in-flight
calibration.Comment: This is an author-created, un-copyedited version of an article
accepted for publication in JINST. IOP Publishing Ltd is not responsible for
any errors or omissions in this version of the manuscript or any version
derived from it. The definitive publisher authenticated version is available
online at http://dx.doi.org/10.1088/1748-0221/4/12/T12013
Esophagogastric dissociation versus fundoplication: Which is best for severely neurologically impaired children?
Purpose: Neurologically impaired children (NIC) often have swallowing difficulties, severe gastroesophageal reflux, recurrent respiratory infections, and malnutrition. Bianchi pro posed esophagogastric dissociation (EGD) as an alternative to fundoplication and gastrostomy. The authors compared these 2 approaches.Methods: Twenty-nine consecutive symptomatic NIC refractory to medical therapy were enrolled in a prospective study and divided into 2 groups: A (n = 12), NIC who underwent fundoplication and gastrostomy; B (n = 14), NIC who underwent EGD. Three were excluded because of previous fundoplication, Anthropometric (percentage of the 50th percentile/ age of healthy children) and biochemical parameters, respiratory infections per year, hospitalization (days per year), feeding time (minutes), and "quality of life" (parental psychological questionnaire, range 0 to 60), were analyzed (t test and Mann-Whitney test) preoperatively and 1 year postoperatively. Complications were recorded.Results: Compared with group A, group B presented a statistically significant increase of all anthropometric and nearly all biochemical parameters with a statistical difference in terms of respiratory infections, hospital stay, feeding time, and psychological questionnaire. In group A, 2 bowel obstructions, 1 tight fundoplication, 1 dumping syndrome, and 3 failures of fundoplication occurred. Group B presented 1 anastomotic stricture, 1 paraesophageal hernia, and 1 bowel obstruction.Conclusions: Compared with fundoplication and gastrostomy, EGD offered better nutritional rehabilitation, reduction in respiratory infections, and improved quality of life. EGD can be rightfully chosen as a primary procedure. J Pediatr Surg 36:677-680. Copyright (C) 2001 by W.B. Saunders Company
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