17 documents found, page 1 of 2
Positive topological entropy for semi-Riemannian geodesic flows
Bessa, Mário; Dias, João Lopes; Matias, Pedro; Torres, M. J.We consider a semi-Riemannian metric whose associated geodesic flow either contains a non-hyperbolic periodic orbit or has infinitely many hyperbolic periodic orbits. Under some conditions, we show that the metric can be C^2-perturbed such that the geodesic flow exhibits positive topological entropy, there are infinitely many non-lightlike closed geodesics, and their number grows exponentially with respect to t...
Positive topological entropy for semi-Riemannian geodesic flows
Bessa, Mário; Dias, João Lopes; Matias, Pedro; Torres, Maria JoanaWe consider a semi-Riemannian metric whose associated geodesic flow either contains a non-hyperbolic periodic orbit or has infinitely many hyperbolic periodic orbits. Under some conditions, we show that the metric can be perturbed such that the geodesic flow exhibits positive topological entropy, there are infinitely many non-lightlike closed geodesics, and their number grows exponentially with respect to the l...
Urban vegetation benefits in mediterranean cities for climate change adaptation...
Matias, Pedro; Silva, Manuela Fernanda Gomes Moreira da; Teigão, João; Duarte, AmilcarIn the current climate change scenario, Mediterranean cities face heatwaves and reduced availability of freshwater alternated with intense precipitation events in short periods. The demand for water, especially for urban and tourism purposes, is rising, particularly in coastal cities. The importance of integrating nature into cities, particularly trees, has been studied for its benefits in adapting to climate c...
Effect of heading cuts on branch growth of ‘Encore’ mandarin
Jacinto, Catarina; Matias, Pedro; Oliveira, Cristina; Duarte, AmilcarPruning can be used for various purposes in citriculture: to control the size and shape of the trees; improve fruit size and quality; manage the alternate bearing and control diseases and pests. However, the physiological response of the tree to heading cuts it´s not well documented. To supplement the lack of studies on the effect of pruning on branch growth, a trial was conducted on ’Encore’ mandarin, in the A...
Efficacy of slow sand filtration enriched with trichoderma atroviride in the co...
Matias, Pedro; Guerreiro David Coelho, Luísa Isabel; Reis, MárioSoilless cultivation is increasingly common, but the nutrient-rich drainage from substrate cultivation is often discarded. However, drainage can be safely reused if previously disinfected. Slow sand filtration (SSF) is a lowcost, ecological, and effective method for water disinfection, primarily through biological control. Enhancing SSF with antagonistic microorganisms is not well-studied. Additionally, SSF has...
Effect of fruit thinning on fruit quality and alternate bearing of ‘Setubalense...
Guerreiro, T.; Trindade, Ana Rita; Duarte, Amilcar; Matias, PedroCitriculture plays a major role in agriculture worldwide, especially in the Mediterranean region. However, there are limitations in citrus production. Alternate bearing can be a big problem when it is very intense. Trees produce a heavy yield one year (“on” year) and light ones the next (“off” year). During the “on” year, trees produce many small-sized fruits, while in the “off” year, they produce very few, lar...
Effects of a severe recovery pruning in the productivity and fruit quality of t...
Matias, Pedro; Duarte, Beatriz; Mendonça, Angélica; Oliveira, Silvino; Barrote, Isabel; Guerrero, Carlos; Duarte, AmilcarCurrently, citrus production plays a major role in worldwide agriculture, especially in the Mediterranean. However, the typical irregular branch development and the formation of large canopies and dense exterior foliage can be significant limitations to light entry and air circulation through the canopy. Consequently, dead branches appear in the inner canopy, which becomes unproductive; flowering and vegetative...
Acoustic and Clinical Data Analysis of Vocal Recordings: Pandemic Insights and ...
Carreiro-Martins, Pedro; Paixão, Paulo; Caires, Iolanda; Matias, Pedro; Gamboa, Hugo; Soares, Filipe; Gomez, Pedro; Sousa, Joana; Neuparth, NunoBackground/Objectives: The interest in processing human speech and other human-generated audio signals as a diagnostic tool has increased due to the COVID-19 pandemic. The project OSCAR (vOice Screening of CoronA viRus) aimed to develop an algorithm to screen for COVID-19 using a dataset of Portuguese participants with voice recordings and clinical data. Methods: This cross-sectional study aimed to characterise...
Citrus Pruning in the Mediterranean climate: a review
Matias, Pedro; Barrote, Isabel; Azinheira, Gonçalo; Continella, Alberto; Duarte, AmilcarPruning is a common practice in citrus for various reasons. These include controlling and shaping the canopy; improving phytosanitary health, productivity, and fruit quality; and facilitating operations such as harvesting and phytosanitary treatments. Because pruning is an expensive operation, its need is sometimes questioned. However, it has been proven to be particularly important in Mediterranean citricultur...
A poda de manutenção em citrinos
Matias, Pedro; Mendonça, Angélica; Oliveira, Silvino; Reis, Valter; Duarte, AmilcarA poda em citricultura é muitas vezes tema de discórdia: enquanto uns a consideram uma prática essencial ou mesmo indispensável, outros acham que é uma prática desnecessária, cujos benefícios não compensam os custos. Na realidade, se realizada da forma e na época adequada, a poda pode funcionar como estratégia para melhorar a produtividade e qualidade da produção, além de atenuar vários problemas da cultura dos...