629 research outputs found
Leveraging different meronym discovery methods for bridging resolution in French
International audienceThis paper presents a statistical system for resolving bridging descriptions in French, a language for which current lexical resources have a very low overage. The system is similar to that developed for English by Poesio but it was enriched to integrate meronymic information extracted automatically from both web queries and raw text using syntactic patterns. Through various experiments on the DEDE corpus, we show that although still mediocre the performance of our system compare favorably to those obtained by Poesio for English. In addition, our evaluation indicates that the different meronym extraction methods have a cumulative effect, but that the text pattern-based extraction method is more robust and leads to higher accuracy than the web-based approach
Tunneling spectroscopy in the magnetic superconductor TmNi2B2C
We present new measurements about the tunneling conductance in the
borocarbide superconductor TmNiBC. The results show a very good
agreement with weak coupling BCS theory, without any lifetime broadening
parameter, over the whole sample surface. We detect no particular change of the
tunneling spectroscopy below 1.5K, when both the antiferromagnetic (AF) phase
and the superconducting order coexist.Comment: Submitted to Phys. Rev. B, Rapid Communication
Explorar e Investigar em Matemática: Uma Actividade Fundamental no Ensino e na Aprendizagem
Investigar, ensinar e aprender são actividades que podem estar presentes, de forma
articulada, no ensino-aprendizagem da Matemática e na actividade profissional do
professor. Para isso, é necessário conceber tarefas que possam ser o ponto de partida para
investigações e explorações matemáticas dos alunos e discutir o modo como podem ser
trabalhadas na sala de aula. Recorrendo a exemplos de actividades realizadas por
professores de Matemática portugueses, analiso a actividade de aprendizagem suscitada
por tarefas deste tipo e discuto as respectivas potencialidades. Finalmente, refiro as
condições respeitantes à cultura profissional dos professores que podem favorecer uma
actividade de investigação sobre a sua própria profissional, com relevo para a colaboração
e a dimensão associativa.Researching, teaching and learning are activities that may be present, in coordination,
teaching and learning of mathematics in the work of the teacher. Therefore, it is necessary
to design tasks that may be the starting point for mathematical investigations and
explorations of the students and discuss how they can be worked in the classroom. Drawing
on examples of activities carried out by Portuguese teachers of mathematics by examining
the activity of learning raised by such tasks and discuss their potencial. Finally, I refer to
conditions relating to the professional culture of teachers who can promote the research
activity on their own training, with an emphasis on collaboration and associative dimension
Determinants of Profitability in the Tourism Sector in Portugal
This paper examines the impact on the profitability of firms in the Portuguese tourism sector of both internal (size, age, growth, debt) and external (real GDP growth rate, sovereign debt crisis, location) determinants. Panel data models have been employed on a large sample of small and medium sized firms, from 2009 to 2017, a period critically influenced by both the financial and the ensuing sovereign debt crisis in the southern European countries. Alternative profitability measures have been used and the results have been largely robust to the distinct models’ specifications. The results suggested that profitability is positively affected by firm’s size and age and by economic real growth rates, and negatively influenced by the firm’s indebtedness ratio and the sovereign debt crisis. Firms in the main tourism regions are generally more profitable, and relatively less affected by the sovereign debt crisis, that was particularly harmful to micro-size firms
Soil organisms in organic and conventional cropping systems.
Apesar do crescente interesse pela agricultura orgânica, são poucas as informações de pesquisa disponíveis sobre o assunto. Assim, num Argissolo Vermelho-Amarelo distrófico foram comparados os efeitos de sistemas de cultivo orgânico e convencional, para as culturas do tomate (Lycopersicum esculentum) e do milho (Zea mays), sobre a comunidade de organismos do solo e suas atividades. As populações de fungos,bactérias e actinomicetos, determinadas pela contagem de colônias em meio de cultura, foram semelhantes para os dois sistemas de produção. A atividade microbiana, avaliada pela evolução de CO2, manteve-se superior no sistema orgânico, sendo que em determinadas avaliações foi o dobro da evolução verificada no sistema convencional. O número de espécimes de minhoca foi praticamente dez vezes maior no sistema orgânico. Não foi observada diferença na taxa de decomposição de matéria orgânica entre os dois sistemas. De modo geral, o número de indivíduos de microartrópodos foi superior no sistema orgânico do que no sistema convencional, refletindo no maior índice de diversidade de Shannon. As maiores populações de insetos foram as da ordem Collembola, enquanto para os ácaros a maior população foi a da superfamília Oribatuloidea. Indivíduos dos grupos Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura e Symphyla foram ocasionalmente coletados e de forma similar entre os sistemas
Calibration of the length of a chain of single gold atoms
Using a scanning tunneling microscope or mechanically controllable break
junctions it has been shown that it is possible to control the formation of a
wire made of single gold atoms. In these experiments an interatomic distance
between atoms in the chain of ~3.6 Angstrom was reported which is not
consistent with recent theoretical calculations. Here, using precise
calibration procedures for both techniques, we measure length of the atomic
chains. Based on the distance between the peaks observed in the chain length
histogram we find the mean value of the inter-atomic distance before chain
rupture to be 2.6 +/- 0.2 A . This value agrees with the theoretical
calculations for the bond length. The discrepancy with the previous
experimental measurements was due to the presence of He gas, that was used to
promote the thermal contact, and which affects the value of the work function
that is commonly used to calibrate distances in scanning tunnelling microscopy
and mechanically controllable break junctions at low temperatures.Comment: 6 pages, 6 figure
Standardization of an isolated pig heart preparation with parabiotic circulation: methodological considerations
In the present study we standardized an experimental model of parabiotic circulation of isolated pig heart. The isolated heart was perfused with arterial blood from a second animal as support and submitted to regional ischemia for 30 min, followed by total ischemia for 90 min and reperfusion for 90 min. Parameters for measurement of ventricular performance using different indices measured directly or indirectly from intraventricular pressure were defined as: maximum peak pressure, final diastolic pressure, pressure developed, first derivative of maximum pressure (dP/dt max), first derivative of minimum pressure (dP/dt min), systolic stress of the left ventricle (sigmas), and maximum elastance of the left ventricle. Isolated hearts subjected to regional and global ischemia presented significant worsening of all measured parameters. Less discriminative parameters were dP/dt max and dP/dt min. Elastance was the most sensitive parameter during the reperfusion period, demonstrating an early loss of ventricular function during reperfusion. The model proved to be stable and reproducible and permitted the study of several variables in the isolated heart, such as ischemia and reperfusion phenomena, the effects of different drugs, surgical interventions, etc. The model introduces an advantage over the classical models which use crystalloid solutions as perfusate, because parabiotic circulation mimics heart surgery with extracorporeal circulation.64965
Cissampelos sympodialis (Menispermaceae): A Novel Phytotherapic Weapon Against Allergic Diseases?
Thickness-modulated tungsten-carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields
We report efficient vortex pinning in thickness-modulated tungsten–carbon-based (W–C) nanostructures grown by focused ion beam induced deposition (FIBID). By using FIBID, W–C superconducting films have been created with thickness modulation properties exhibiting periodicity from 60 to 140 nm, leading to a strong pinning potential for the vortex lattice. This produces local minima in the resistivity up to high magnetic fields (2.2 T) in a broad temperature range due to commensurability effects between the pinning potential and the vortex lattice. The results show that the combination of single-step FIBID fabrication of superconducting nanostructures with built-in artificial pinning landscapes and the small intrinsic random pinning potential of this material produces strong periodic pinning potentials, maximizing the opportunities for the investigation of fundamental aspects in vortex science under changing external stimuli (e.g., temperature, magnetic field, electrical current)
Alterações hematológicas e bioquímicas em cadelas com neoplasias mamárias e carcinoma inflamatório
Alterações hematológicas e bioquímicas em animais portadores de neoplasias podem resultar dos efeitos diretos do crescimento tumoral ou de síndromes paraneoplásicas. O objetivo deste estudo foi avaliar as alterações hematológicas e bioquímicas em cadelas com neoplasias mamárias e carcinoma inflamatório (IC). Foram coletadas amostras de sangue de 43 cadelas divididas em três grupos de acordo com o estadiamento clínico: grupo 1 (G1) - cadelas em estádio inicial (T1,2,3N0M0, N=17), grupo 2 (G2) - cadelas em estádio avançado (T1,2,3N1M0,1, N=15) e grupo 3 (G3) - cadelas que apresentaram IC (N=11). Os parâmetros hematológicos e bioquímicos obtidos foram relacionados com o estadiamento clínico das pacientes. Entre as alterações, as mais comuns foram anemia, leucocitose neutrofílica, monocitose, aumento de ALT, AST e hipoalbuminemia, principalmente em cadelas em estadiamento clínico avançado e com carcinoma inflamatório.Hematological and biochemical alterations in animals with neoplasms may result from the direct effects of tumor growth or paraneoplastic syndromes. The objective of this study was to evaluate these hematological and biochemical alterations in female dogs with mammary tumors and with inflammatory carcinoma (IC). Blood samples were collected from 43 female dogs divided into three groups according to clinical staging: Group 1 (G1) - animals in initial stage (T1,2,3N0M0, N=17), Group 2 (G2) - animals in advanced stage (T1,2,3N1M0,1, N=15) and Group 3 (G3) - animals presenting IC (N=11). Hematological and biochemical parameters obtained were related to patients' clinical staging. Among alterations, the most common were anemia, neutrophilic leukocytosis, monocytosis, increased ALT, AST, and hypoalbuminemia, mainly in dogs in advanced clinical staging and with inflammatory carcinoma
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