1,348 research outputs found
Proceedings from the ECFIN Workshop "The budgetary implications of structural reforms" - Brussels, 2 December 2005
Most of the reforms discussed within the framework of the Lisbon strategy will benefit public finances in the long term. However, in the short-term, there could a trade-off between some structural reforms and budgetary discipline. This possible tension between reforms and fiscal discipline was identified by academic economists as a possible drawback of the Stability and Growth Pact since its inception.budgetary discipline, Stability and Growth Pact, Lisbon strategy, fiscal discipline, Deroose, Flores, Turrini
Habitable Planet Formation in Binary-Planetary Systems
Recent radial velocity observations have indicated that Jovian-type planets
can exist in moderately close binary star systems. Numerical simulations of the
dynamical stability of terrestrial-class planets in such environments have
shown that, in addition to their giant planets, these systems can also harbor
Earth-like objects. In this paper, we study the late stage of terrestrial
planet formation in such binary-planetary systems, and present the results of
the simulations of the formation of Earth-like bodies in their habitable zones.
We consider a circumprimary disk of Moon- to Mars-sized objects and numerically
integrate the orbits of these bodies at the presence of the Jovian-type planet
of the system and for different values of the mass, semimajor axis, and orbital
eccentricity of the secondary star. Results indicate that, Earth-like objects,
with substantial amounts of water, can form in the habitable zone of the
primary star. Simulations also indicate that, by transferring angular momentum
from the secondary star to protoplanetary objects, the giant planet of the
system plays a key role in the radial mixing of these bodies and the water
contents of the final terrestrial planets. We will discuss the results of our
simulation and show that the formation of habitable planets in binary-planetary
systems is more probable in binaries with moderate to large perihelia.Comment: 27 pages, 11 figures, submitted for publicatio
Camera re-calibration after zooming based on sets of conics
We describe a method to compute the internal parameters (focal and principal points) of a camera with known position and orientation, based on the observation of two or more conics on a known plane. The conics can even be degenerate (e.g. pairs of lines). The proposed method can be used to re-estimate the internal parameters of a fully calibrated camera after zooming to a new, unknown, focal length. It also allows estimating the internal parameters when a second, fully calibrated camera observes the same conics. The parameters estimated through the proposed method are coherent with the output of more traditional procedures that require a higher number of calibration images. A deep analysis of the geometrical configurations that influence the proposed method is also reported
Diversity of a phosphate transporter gene among species and isolates of arbuscular mycorrhizal fungi
Arbuscular mycorrhizal fungi (AMF) are a key group of beneficial obligate biotrophs, establishing a mutualistic symbiosis with the roots of most land plants. The molecular markers generally used for their characterization are mainly based on informative regions of nuclear rDNA (SSU-ITS-LSU), although protein-encoding genes have also been proposed. Within functional genes, those encoding for phosphate transporters (PT) are particularly important in AMF, given their primary ability to take up Pi from soil, and to differentially affect plant phosphate nutrition. In this work, we investigated the genetic diversity of PT1 gene sequences and sequences of the taxonomically relevant SSU-ITS-LSU region in two isolates of the species Funneliformis coronatus, three isolates of the species Funneliformis mosseae and two species of the genus Rhizoglomus, originated from geographically distant areas and cultured in vivo. Our results showed that partial PT1 sequences not only successfully differentiated AMF genera and species like ribosomal gene sequences but also highlighted intraspecific diversity among F. mosseae and F. coronatus isolates. The study of functional genes related to the uptake of key mineral nutrients for the assessment of AMF diversity represents a key step in the selection of efficient isolates to be used as inocula in sustainable agriculture
Model checking ω-regular properties for quantum Markov chains
© Yuan Feng, Ernst Moritz Hahn, Andrea Turrini, and Shenggang Ying. Quantum Markov chains are an extension of classical Markov chains which are labelled with super-operators rather than probabilities. They allow to faithfully represent quantum programs and quantum protocols. In this paper, we investigate model checking !-regular properties, a very general class of properties (including, e.g., LTL properties) of interest, against this model. For classical Markov chains, such properties are usually checked by building the product of the model with a language automaton. Subsequent analysis is then performed on this product. When doing so, one takes into account its graph structure, and for instance performs different analyses per bottom strongly connected component (BSCC). Unfortunately, for quantum Markov chains such an approach does not work directly, because super-operators behave differently from probabilities. To overcome this problem, we transform the product quantum Markov chain into a single super-operator, which induces a decomposition of the state space (the tensor product of classical state space and the quantum one) into a family of BSCC subspaces. Interestingly, we show that this BSCC decomposition provides a solution to the issue of model checking ω-regular properties for quantum Markov chains
Comportamentos Afetivo-motivacionais e de Autorregulação em Pré-escolares Nascidos Prematuros e com Baixo Peso: Avaliação e Intervenção em Estratégias Metacognitivas
Comportamentos afetivo-motivacionais relacionados Ă metacognição de regulação na idade prĂ©-escolar podem mediar o desempenho de crianças em risco de problemas no desenvolvimento, como nos casos de prematuridade e baixo peso ao nascimento (PTBP), tema desta pesquisa, realizada com 3 estudos. No Estudo 1, aplicou-se o Checklist para Avaliação do Comportamento Afetivo-Motivacional Infantil (ACAMI) em 15 crianças do G1-PTBP, durante uma prova cognitiva assistida (CATM, com fases Sem Ajuda-SAJ, AssistĂŞncia-ASS, Manutenção-MAN, TransferĂŞncia-TRF), mostrando diferenças significativas nos comportamentos nĂŁo-facilitadores em todas as fases do CATM, especialmente no Engajamento na Tarefa e Estados Emocionais, quando comparadas com 15 crianças nascidas a termo (G2-AT), aos 5 anos de idade. Os resultados corroboram a literatura relacionando fatores afetivo-motivacionais e desempenho cognitivo, e a prematuridade e o baixo peso com riscos para problemas de comportamento. No Estudo 2, 34 crianças do G1-PTBP (17) e do G2-AT (17) responderam a 2 subtestes da de uma prova metacognitiva assistida - Application of Cognitive Functions Scale (ACFS). Os comportamentos durante a ACFS foram registrados pela Behavior Observation Rating Scale (BORS). Ambos os grupos, na fase SAJ, tiveram dificuldades em verbalizar estratĂ©gias mnemĂ´nicas; usando mais frequentemente a estratĂ©gia de Repetição. Mas, tiveram aumento significativo na mĂ©dia de acertos nos 2 subtestes, comparando-se as fases SAJ e MAN. Na BORS, houve diferenças significativas a favor do G2-AT em Autorregulação, PersistĂŞncia e Tolerância Ă Frustração, confirmando a diferença entre os grupos. O Estudo 3 analisou os efeitos de um programa de promoção de estratĂ©gias metacognitivas (PPEM) no desempenho linguĂstico, acadĂŞmico, cognitivo, metacognitivo e comportamental das crianças PTBP, em delineamento quase-experimental. No prĂ©-teste, 17 crianças do G1-PTBP e 17 do G2-AT foram avaliadas no desempenho: a) cognitivo tradicional (Raven-MPC) e assistido (CATM e ACAMI); b) metacognitivo assistido (ACFS); c) linguĂstico receptivo (TVIP) e expressivo (LAVE); d) acadĂŞmico (IAR); e) problemas de comportamento (CBCL-1½-5 anos). Foram submetidas ao PPEM 13 crianças do G1-PTBP (15 sessões, 2 vezes/semana), intervindo-se em: (a) autorregulação comportamental, (b) aprendizagem social e (c) sequĂŞncia e padrões cognitivos. G1-PTBP (13) e G2-AT (16) passaram pelo pĂłs-teste. No seguimento (apĂłs 6 meses), G1-PTBP (9) respondeu as provas assistidas: cognitiva (CATM) e metacognitiva (ACFS). No prĂ©-teste, G2-AT foi significativamente melhor em: repertĂłrio prĂ©-alfabetização (IAR); comportamentos internalizantes (CBCL); cognição (CATM - nĂveis de mediação), nos comportamentos afetivo-motivacionais (ACAMI) e na metacognição de regulação (autorregulação, persistĂŞncia e tolerância Ă frustração- ACFS). ApĂłs a aplicação do PPEM, houve efeito compensatĂłrio, ficando sem diferenças em: problemas de comportamento, repertĂłrio prĂ©-alfabetização, nĂveis de mediação e autorregulação. No seguimento, G1-PTBP melhorou nos comportamentos afetivo-motivacionais (ACAMI). O PPEM permitiu o desenvolvimento de habilidades básicas para escolarização, nesse grupo de risco para fracasso escolar. Como ApĂŞndice, um capĂtulo de livro ilustra 2 casos do G1-PTBP, destacando o papel dos comportamentos afetivo-motivacionais e de autorregulação, como fatores de risco e de proteção capazes de mediar os efeitos potenciais do risco ao desenvolvimento.
Palavras-chave: Educação Metacognitiva; Pré-escolares; Nascimento prematur
Probing the origin of the dark material on Iapetus
Among the icy satellites of Saturn, Iapetus shows a striking dichotomy
between its leading and trailing hemispheres, the former being significantly
darker than the latter. Thanks to the VIMS imaging spectrometer on-board
Cassini, it is now possible to investigate the spectral features of the
satellites in Saturn system within a wider spectral range and with an enhanced
accuracy than with previously available data. In this work, we present an
application of the G-mode method to the high resolution, visible and near
infrared data of Phoebe, Iapetus and Hyperion collected by Cassini/VIMS, to
search for compositional correlations. We also present the results of a
dynamical study on the efficiency of Iapetus in capturing dust grains
travelling inward in Saturn system to evaluate the viability of
Poynting-Robertson drag as the physical mechanism transferring the dark
material to the satellite. The results of spectroscopic classification are used
jointly with the ones of the dynamical study to describe a plausible physical
scenario for the origin of Iapetus' dichotomy. Our work shows that mass
transfer from the outer Saturnian system is an efficient mechanism,
particularly for the range of sizes hypothesised for the particles composing
the newly discovered outer ring around Saturn. Both spectral and dynamical data
indicate Phoebe as the main source of the dark material. However, we suggest a
multi-source scenario where now extinct prograde satellites and the disruptive
impacts that generated the putative collisional families played a significant
role in supplying the original amount of dark material.Comment: 20 pages, 4 tables, 11 figures, major revision (manuscript extended
and completed, figures added and corrected, new results added), minor
revision and finalization of author list, moderate revision (update of the
manuscript following reviewer's feedback and discovery of the new Saturnian
outer ring
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