Plantas exóticas e invasoras na Ilha do Pico (Açores).

VI Expedição Científica do Departamento de Biologia - Pico 1991.As ilhas são lugares ideais para a instalasão e desenvolvimento de plantas invasoras, quer sejam trazidas por meios naturais ou pelo Homem. As plantas invasoras são bastante agressivas, e como ao chegarem a uma ilha raramente encontram os seus inimigos naturais, elas espalham-se muito rapidamente e desalojam as plantas nativas. Por um lado com a sua presença elas parecem aumentar a Biodiversidade total da Ilha, no entanto com a sua agressividade elas são responsáveis pela diminuição da Biodiversidade natural primária. As plantas exóticas, normalmente trazidas pelo Homem, com fins económicos e/ou ornamentais, podem também tornar-se plantas invasoras. É, de qualquer maneira, elas constituem uma alteração da paisagem natural. Dado que as fronteiras das ilhas são o mar e o ar é relativamente fácil, e absolutamente indispensável, que se controle a entrada de plantas exóticas, isto é, não nativas. Por outro lado deve-se fazer o controle e irradicação de todas aquelas plantas exóticas e invasoras que existam, ou sejam detectadas, nas ilhas. Segue-se uma lista de Plantas Exóticas e Invasoras detectadas na Ilha do Pico durante a Expedição Científica PICO/91, organizada pelo Departamento de Biologia da Universidade dos Açores

Paratrichodorus divergens sp. n., a new potential virus vector of tobacco rattle virus and additional observations on P. hispanus Roca & Arias, 1986 from Portugal (Nematoda: Trichodoridae)

During a survey of trichodorids in Continental Portugal, a new trichodorid species, Paratrichodorus divergens sp. n., was found. It is described and illustrated with specimens from the type locality and additional morphometric data and photographs of specimens obtained from soil samples collected in seven other localities are also included. The species is characterised in female by distinct drop-like to triangular oblique vaginal sclerotisations diverging outwards, sperm cells usually distributed all through the uteri, and in male by thin, almost straight, striated spicules, the two posteriormost pre-cloacal supplements relatively close to one another and usually opposite the distal third of retracted spicules, a slightly bilobed cloacal lip and sperm cells with sausage-shaped nucleus. Paratrichodorus divergens sp. n. most closely resembles P. hispanus Roca & Arias, 1986 with which it often occurs in mixed populations. Additional information is also provided for P. hispanus. For the new species, coding of the features are added following Decraemer and Baujard’s identification key.Centro de Biologia da Universidade do Minho (CB)

A method to discriminate species of virus vector trichodorid nematodes exploring 18S rDNA region

European Consortium for the Barcode Of Life (ECBOL

First report of Meloidogyne naasi parasitizing turfgrass in Portugal

In an exploratory sampling of a football field in Porto, Portugal, the root-knot nematode, Meloidogyne naasi, previously unreported from the Iberian Peninsula, was detected. Diagnosis was based on the analysis of perineal patterns and esterase phenotypes of females excised from grass roots, morphometrics and molecular analysis (PCR with specific primers and analysis of partial 28S sequences obtained by amplification using the primers D2A/D3B) of second- stage juveniles (J2) extracted from soil. When collected in water, J2 aggregated into a worm-star. Endospores of Pasteuria penetrans were frequently found attached to the J2. To our knowledge, this is the first report of M. naasi in Portugal and in the Iberian Peninsula, and the first report of worm-star formation in Meloidogyne.The authors would like to thank Dr. M. Luísa Moura and José F. Azevedo for collaboration in sampling and sample processing. This work was supported by the strategic program UID/BIA/04050/2019 (POCI01-0145-FEDER-007569), funded by national funds through the Portuguese Foundation For Science and Technology (FCT) I.P. and by the ERDF through the COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI)

Complementary eigenvalue problem in systems with frictional contact: the stiffness matrix for the contact nodes between different materials

This work addresses a numerical study of static equilibrium states of finite dimensional systems with frictional contact and its application to the particular problem of friction between two geological layers with different viscosity. Its formulation as a complementarity eigenproblem requires the building up of mass M and stiffness K matrices to solve the eigenvalue equations for the relative deformation of two contacting materials.Fundação para a Ciência e a Tecnologia (FCT

Non-destructive assay employing 2D and 3D digital radiographic imaging acquired with thermal neutrons and reactor-produced radioisotopes

The inner structure of some objects can only be visualized by using suitable techniques, when safety reasons or expensive costs preclude the application of invasive procedures. The kind of agent rendering an object partially transparent, unveiling thus its features, depends upon the object size and composition. As a rough rule of thumb, light materials are transparent to gamma and X-rays while the heavy ones are transparent to neutrons. When, after traversing an object, they hit a proper 2-D detector, a radiograph is produced representing a convoluted cross section, called projection, of that object. Taking a large number of such projections for different object attitudes, it is possible to obtain a 3-D tomography of the object as a map of attenuation coefficients. This procedure however, besides a time-consuming task, requires specially tailored equipment and software, not always available or affordable. Yet, in some circumstances it is feasible to replace the 3-D tomography by a stereoscopy, allowing one to visualize the spatial configuration of the object under analysis. In this work, 2-Dand 3-D radiographic images have been acquired using thermal neutrons and reactor-produced radioisotopes and proper imaging plates as detectors. The stereographic vision has been achieved by taking two radiographs of the same object at different angles, from the detector point of view. After a treatment to render them red-white and green-white they were properly merged to yield a single image capable to be watched with red-green glasses. All the image treatment and rendering has been performed with the software ImageJ

Special matrices for visco-elastic systems

In this work the evolution of visco-elastic systems under external stress is addressed. An approach as a mixed complementary eigenvalue problem to model the geological folding and asymmetric boudinage in the same direction is considered. A matricial dynamics equation that comprehends elasticity and viscosity matrices is presented. An algorithm to connect material points and to build the adjacency matrix has been developed. Numerical results for a set of 16 nodes are shown.Portuguese Funds through FCT - ’Fundação para a Ciência e a Tecnologia’, UID/MAT/00013/2013. European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Fundação para a Ciência e Tecnologia. Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013.info:eu-repo/semantics/publishedVersio

On the Richardson-Lucy Algorithm with A Varying Point Spread Function along The Iterations

Abstract: This work analyses the soundness of two algorithms, Fishsint and Almexp to improve images using the Richardson-Lucy (RL) algorithm under a varying Point Spread Function (PSF) along the iterations. A plethora of methods based on Richardson-Lucy has been published, but no further proposal involving such an alternative has been published. Whereas the unnamed predecessor of Fishsint addressed only small size synthetic images under a blind fashion procedure, Fishsint and Almexp employs an algorithm Wdet to determine the initial PSF and all subsequent values after each iteration, respectively. Fishsint performs a loop, where the last determined PSF improves the previously obtained image and vice versa. Its original unnamed version has been modified in the present work by entering a previously determined initial PSF to accelerate the convergence. The algorithm Almexp, as well, uses the algorithm Wdet to determine the PSF of the last obtained image to deconvolve itself. Therefore, whereas the Fishsint unnamed predecessor used an initial guess PSF - chosen by the customer - Almexp determines the PSF always through the algorithm Wdet. Fishsint and Almexp furnish final images which outperform those obtained with the original Richardson-Lucy approach working under a constant PSF along the iterations. Hence, in order to carry out a comparison between their performances, all the algorithms have been embedded into an ad hoc written Fortran 90 program. The results corroborate the soundness of a varying PSF along the iterations with the Richardson Lucy algorithm. Keywords: Richardson-Lucy, varying PSF along iterations, image improvement, neutron radiograph

Astrophysics datamining in the classroom: Exploring real data with new software tools and robotic telescopes

Within the efforts to bring frontline interactive astrophysics and astronomy to the classroom, the Hands on Universe (HOU) developed a set of exercises and platform using real data obtained by some of the most advanced ground and space observatories. The backbone of this endeavour is a new free software Web tool - Such a Lovely Software for Astronomy based on Image J (Salsa J). It is student-friendly and developed specifically for the HOU project and targets middle and high schools. It allows students to display, analyze, and explore professionally obtained astronomical images, while learning concepts on gravitational dynamics, kinematics, nuclear fusion, electromagnetism. The continuous evolving set of exercises and tutorials is being completed with real (professionally obtained) data to download and detailed tutorials. The flexibility of the Salsa J platform tool enables students and teachers to extend the exercises with their own observations. The software developed for the HOU program has been designed to be a multi-platform, multi-lingual experience for image manipulation and analysis in the classroom. Its design enables easy implementation of new facilities (extensions and plugins), minimal in-situ maintenance and flexibility for exercise plugin. Here, we describe some of the most advanced exercises about astrophysics in the classroom, addressing particular examples on gravitational dynamics, concepts currently introduced in most sciences curricula in middle and high schools.Comment: 10 pages, 12 images, submitted to the special theme issue Using Astronomy and Space Science Research in Physics Courses of the American Journal of Physic