Coleta de germoplasma de arroz no Amazonas e Acre.

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Monoenergetic proton beams accelerated by a radiation pressure driven shock

High energy ion beams (> MeV) generated by intense laser pulses promise to be viable alternatives to conventional ion beam sources due to their unique properties such as high charge, low emittance, compactness and ease of beam delivery. Typically the acceleration is due to the rapid expansion of a laser heated solid foil, but this usually leads to ion beams with large energy spread. Until now, control of the energy spread has only been achieved at the expense of reduced charge and increased complexity. Radiation pressure acceleration (RPA) provides an alternative route to producing laser-driven monoenergetic ion beams. In this paper, we show the interaction of an intense infrared laser with a gaseous hydrogen target can produce proton spectra of small energy spread (~ 4%), and low background. The scaling of proton energy with the ratio of intensity over density (I/n) indicates that the acceleration is due to the shock generated by radiation-pressure driven hole-boring of the critical surface. These are the first high contrast mononenergetic beams that have been theorised from RPA, and makes them highly desirable for numerous ion beam applications

Finding SQL Injection and Cross Site Scripting Vulnerabilities with Diverse Static Analysis Tools

The use of Static Analysis Tools (SATs) is mandatory when developing secure software and searching for vulnerabilities in legacy software. However, the performance of the various SATs concerning the detection of vulnerabilities and false alarm rate is usually unknown and depends on many factors. The simultaneous use of several tools should increase the detection capabilities, but also the number of false alarms. In this paper, we study the problem of combining several SATs to best meet the developer needs. We present results of analyzing the performance of diverse static analysis tools, based on a previously published dataset that resulted from the use of five diverse SATs to find two types of vulnerabilities, namely SQL Injections (SQLi) and Cross-Site Scripting (XSS), in 132 plugins of the WordPress Content Management System (CMS). We present the results based on well-established measures for binary classifiers, namely sensitivity and specificity for all possible diverse combinations that can be constructed using these 5 SAT tools. We then provide empirically supported guidance on which combinations of SAT tools provide the most benefits for detecting vulnerabilities with low false positive rates

The impact of alternative science education methodologies on the motivation and acquisition of scientific concepts

Fully aware of the increasing importance of active and experimental learning, this study has been conducted in Portugal between 2007 and 2008 and was the first of this kind to ever be conducted in this country. Thirty eight students of the school E.B. 2, 3 D. Maria II (middle school) participated in the extra-curricular activity entitled “Scientists for a Day”, previous developed by the Life and Health Science Research Institute/School of Health Science (ICVS/ECS), University of Minho. This activity realized in the School E.B. 2, 3 D. Maria II and organized by teachers of the same School consisted in a set of laboratory activities subdivided into four experimental stations, namely: 1st Station – “Extracting banana DNA”; 2nd Station – “Acid/Base”, 3rd Station – “Observation of chicken embryos” and 4th Station – “Five Senses”. The general objectives of this activity were to stimulate the pleasure of knowledge, encourage critical views, heighten the interest in science, motivate students towards experimental work and demystify the idea of what a Scientist is. In an effort to validate this activity and evaluate what they have learned, the students were asked to answer a questionnaire before and immediately after this activity. In this study we observed a clear correlation between the use of active and experimental learning activities, and an increase in scientific knowledge

Long-term follow-up of myopic choroidal neovascularization treated with ranibizumab

PURPOSE: To evaluate the long-term safety and efficacy of intravitreal ranibizumab in the treatment of myopic choroidal neovascularization (CNV). METHODS: Three-year retrospective, nonrandomized, interventional case series. Forty eyes of 39 patients with myopic CNV were included; 15 with previous photodynamic therapy, and 25 naïve eyes. Best-corrected visual acuity (BCVA) changes, central foveal thickness (CFT), and number of treatments were assessed, from baseline to month 36. RESULTS: Mean visual acuity improved from 55.4 Early Treatment Diabetic Retinopathy Study (ETDRS) letters at baseline to 59.7 letters at 12 months (p = 0.07), 61.8 letters at 24 months (p = 0.008) and 63.4 letters at 36 months (p = 0.039). Twenty-five percent of the patients gained ≥15 letters (3 lines) at 12 months, 30% at 24 months and 35% at 36 months. There was a mean reduction of 80 μm in CFT (p < 0.001). A mean of 4.1 injections were performed in the first year, 2.4 in the second year and 1.1 in the third year. Fifty-three percent of the eyes had no need for treatment during the third year of follow-up. CONCLUSIONS: Intravitreal ranibizumab seems to be an effective and safe therapeutic procedure to treat CNV in highly myopic eyes, with a high proportion of patients gaining or stabilizing BCVA at a 3-year follow-up.info:eu-repo/semantics/publishedVersio

Automated apparatus for gas solubility measurements

An automated apparatus based on the Ben-Naim-Baer and Tominaga et al. designs [A. Ben-Naim, S. Baer, Trans. Faraday Soc. 59 (1963) 2735-2738; T. Tominaga, R. Battino, H.K. Gorowara, R.D. Dixon, J. Chem. Eng. Data 31 (1986) 175-180] has been implemented for measurements of gas solubilities in liquids under atmospheric pressure and room temperatures. The uncertainty in the measurement of gas solubilities was estimated from the uncertainties in the directly measured quantities using the error propagation law. The accuracy of the experimental method was checked by measuring the solubility of carbon dioxide and nitrous oxide in water in the range T = (290 to 303) K, being found to be 0.6%. A precision of the same order of magnitude was achieved.http://www.sciencedirect.com/science/article/B6WHM-4NYSXR7-2/1/adfe1ea651a5aee6dce7d49f424899b

On the Yang-Lee and Langer singularities in the O(n) loop model

We use the method of `coupling to 2d QG' to study the analytic properties of the universal specific free energy of the O(n) loop model in complex magnetic field. We compute the specific free energy on a dynamical lattice using the correspondence with a matrix model. The free energy has a pair of Yang-Lee edges on the high-temperature sheet and a Langer type branch cut on the low-temperature sheet. Our result confirms a conjecture by A. and Al. Zamolodchikov about the decay rate of the metastable vacuum in presence of Liouville gravity and gives strong evidence about the existence of a weakly metastable state and a Langer branch cut in the O(n) loop model on a flat lattice. Our results are compatible with the Fonseca-Zamolodchikov conjecture that the Yang-Lee edge appears as the nearest singularity under the Langer cut.Comment: 38 pages, 16 figure

Controlling pollution effects on metallic cultural heritage using linear sweep voltammetry

This work demonstrates the potentialities of the linear sweep voltammetry (LSV) for monitoring the composition of the tarnishing layers formed on silver and on the silver-copper alloys exposed to atmospheres contaminated with pollutants, such as H2S and chloride ions, among others. A collection of silver and sterling silver coupons exposed during periods of 1 and 12 months, at the Holy Altar of the Chapel and at the Treasure Room of the Museum, both of the Porto Cathedral (Portugal), with exposures started in march 2010 and ending in march 2011, have been analysed by LSV. The LSV spectra of blank polished samples as well as samples covered with thin films of silver sulphide and of silver chloride, formed under controlled conditions, respectively: (i) H2S, 1000 ppm, RH= 53% ± 2, T= 21˚C ± 1, over periods of 24, 48 and 72 h and (ii) 3.5% of NaCl, RH=41%, T= 43˚C, periods of 5 h, have been used as references. The influence of the atmosphere (Chapel and Museum), exposure time (1 and 12 months) and season, in which the exposures were started, (spring, summer, autumn and winter) have been analysed on the LSVs of the coupons exposed to the various conditions. For the 1 month exposures started in spring the peaks corresponding to the silver sulphide and silver chloride were, as expected, higher on the samples exposed in the Chapel. For the 12 months exposures both peaks have increased in size with the peak assigned to chloride being much higher in the case of the Chapel and the reverse observed in the case of the Museum. The seasonal influence, even for the 1 month exposures was particularly notable on those started in winter with well visible effects on the sulphide and chloride peaks respectively, in the Museum and Chapel exposures