918 research outputs found
An Extensive Empirical Comparison of Probabilistic Hierarchical Classifiers in Datasets of Ageing-Related Genes
This study comprehensively evaluates the performance of 5 types of probabilistic hierarchical classification methods used for predicting Gene Ontology (GO) terms related to ageing. Of those tested, a new hybrid of a Local Hierarchical Classifier (LHC) and the Predictive Clustering Tree algorithm (LHC-PCT) had the best predictive accuracy results. We also tested the impact of two types of variations in most hierarchical classification algorithms, namely: (a) changing the base algorithm (we tested Naive Bayes and Support Vector Machines), and the impact of (b) using or not the Correlation based Feature Selection (CFS) algorithm in a pre-processing step. In total, we evaluated the predictive performance of 17 variations of hierarchical classifiers across 15 datasets of ageing and longevityrelated genes. We conclude that the LHC-PCT algorithm ranks better across several tests (7 out of 12). In addition, we interpreted the models generated by the PCT algorithm to show how hierarchical classification algorithms can be used to extract biological insights out of the ageing-related datasets that we compiled
Herpetofauna From An Urban Pampa Fragment In Southern Brazil: Composition, Structure And Conservation
Faunistic inventories regarding natural history of amphibians and reptiles are considered scarce and very little is known about their assemblages in urban areas; the Pampas morphoclimatic domain, also known as Uruguayan Savannah or Southern Grasslands, is also poorly known regarding their faunal composition. Herein, we present a checklist of 16 amphibian and 20 reptile species recorded over a course of four years in the Instituto Federal de Educação, Ciências e Tecnologia, Câmpus Pelotas-Visconde da Graça, in Pelotas, Rio Grande do Sul, Brazil. We also present data on natural history and discuss conservation efforts to be undertaken in the area, in one of the least preserved and known Brazilian morphoclimatic domains, providing insights into urban herpetofaunal diversity patterns and showing the importance of modified areas in its conservation. © 2016 Check List and Authors.12
Monitoring nitrogen nutritional status of vegetables in the social garden of Polytechnic Institute of Bragança, NE Portugal
Urban agriculture is a global phenomenon. In developing countries urban agriculture has had crucial importance in alleviating problems of extreme poverty and unemployment of the populations of the larger cities. In developed countries has been particularly important during periods of economic depression. Nowadays, the urban agriculture in developed countries is increasing, aimed more at leisure, sports and recreation of the urban dwellers. These spaces are also emphasizing environmental education awareness by implementing environmentally friendly agricultural practices. In the case of Portugal, urban agriculture is frequently regulated by norms, implicitly or explicitly, similar to those established for organic farming. The urban agriculture project of the Polytechnic Institute of Bragança (IPB) is one of these kinds of projects in which participants are encouraged to use sustainable farming practices. The fertilizers used are usually farmyard manures and other organic wastes. This work takes part of a larger project that aims to monitor the nutritional status of the plants, the residual mineral nitrogen content in the soil and the contamination of plants and soils with heavy metals. In this report, it will be present results only for the first two goals
Self-reseeding annual legumes for cover cropping in rainfed managed olive orchards
Given the environmental impact of nitrogen (N)-fertilizer manufacture and use, the sustainable management of agro-systems
should be sought by growing N-fixing legumes. In this work, eleven self-reseeding annual legumes were grown in pure stands as
mulching cover crops in a rainfed olive orchard managed without grazing animals. Dry matter yield, N content in above-ground
biomass, groundcover percentage and persistence of the sown species were assessed during four growing seasons. All covers provided
enough soil protection over the year, with living plants during the autumn/winter period and a mulch of dead residues during
the summer. The legumes overcame a false break observed in the third year recovering the dominance of the covers in the fourth
growing season. This means that the seed bank established in previous seasons ensured the persistence of the sown legume even
when a gap in seed production occurred. The early-maturing cultivars produced less biomass and fixed less N (approx. 50 kg N/ha/yr
present in the above-ground biomass) than the late-maturing ones, but would compete less for water since the growing cycle
finished earlier in the spring. They seem best suited to being grown in dry farmed olive orchards with low N demand in drought
prone regions.info:eu-repo/semantics/publishedVersio
A poda influencia a produção do olival tradicional? A que nÃvel?
O olival tradicional constitui-se como a principal atividade económica da Terra Quente
Transmontana, pelas pessoas que envolve e pelas receitas que gera. O setor passa, contudo,
uma fase difÃcil decorrente dos baixos preços a que o azeite é comercializado. Para manter a
atividade com sustentabilidade económica é necessário maximizar a produtividade e reduzir
custos. Um dos aspetos da técnica cultural que mais pode influenciar o resultado económico
da cultura é a poda, pelos custos que acarreta e pela forma como pode influenciar a
produtividade das árvores. Neste trabalho, apresentam-se resultados do efeito de vários
regimes de poda na produtividade e outros aspetos da fisiologia da árvore.
O ensaio de campo está instalado em Valongo, Mirandela. Consiste em quatro regimes
de poda, designadamente poda severa, poda moderada, poda ligeira e não poda
(testemunha). Nos regimes de poda severa, moderada e ligeira procurou remover-se,
respetivamente, 75, 50 e 25% da rama. Na modalidade testemunha não se efetuou poda. No
inÃcio do ensaio as árvores estavam no terceiro ano após o último evento de poda. Cada
regime de poda foi aplicado a um grupo homogéneo de dez árvores.
No Inverno anterior à poda a produção foi muito baixa (valor médio de 2,2 kg/árvore)
e sem diferenças significativas entre os quatro grupos de árvores submetidos a poda
diferenciada na Primavera seguinte. As produções médias de azeitona na primeira colheita
após a poda foram de 17,1, 15,7, 9,8 e 2,0 kg/árvore, respetivamente nas modalidades
testemunha, poda ligeira, poda moderada e poda severa. O calibre dos frutos variou de forma
inversa à produção, registando-se os valores de 237,5, 298,7, 377,8 e 451,6 g por 100
azeitonas. A concentração de nutrientes nas folhas variou significativamente em função dos
regimes de poda, bem como os valores de clorofila-SPAD determinados com o aparelho
portátil SPAD-502. Assim, em análise de curto prazo, a poda reprimiu fortemente a produção
de azeitona, possivelmente por remover folhas, que se constituem como a principal reserva
de fotoassimilados da planta e o aparato fotossintético responsável pela aquisição de mais
produtos da fotossÃntese no futuro. A alteração verificada no estado nutricional das plantas
em função do regime de poda e o lançamento diferenciado de rebentação de tronco (ladrões)
irá repercutir-se seguramente nos ciclos produtivos dos anos seguintes.info:eu-repo/semantics/publishedVersio
Preliminary critical nitrogen nutritional indices for lemon balm (Melissa officinalis) grown in a Mediterranean environment in North-Eastern Portugal
The management of crop fertilization presupposes previous diagnoses of soil fertility and plant nutritional status. In Europe, regular soil testing and plant analysis is mandatory for farmers receiving EU subsidies. Soil testing provides information on the potential availability of nutrients in the soil, a key component in the fertilization recommendation systems. By analyzing plant tissues we can access the nutritional status of a crop, which allows understanding if supplemental fertilization is needed. Without these means of diagnostic, fertilization is an entirely empirical practice. The sector of Medicinal and Aromatic Plants (MAP) seems to be out of that logical. For most MAP it were not yet established sufficiency ranges or critical levels that allows the interpretation of plant analysis results (see Mills and Jones, 1996; INIAP-LQARS, 2006). Taken into account that most of MAP production in Europe is organic, and that this may requires the use of expensive commercial organic manures, the situation seems to be unsustainable. There is a real need for sufficiency ranges or critical levels allowing the use of plant analysis as a diagnostic criterion on its nutritional status for a judicious decision on the rate of nutrients to apply. This work is part of a wider project that is still beginning, which main goal is to establish sufficiency ranges or critical levels for some MAP that are having great economic importance in Portugal. In this paper, preliminary results for lemon balm (Melissa officinalis L.) are presented.Projeto PRODER n.º 46025 - Gestão Sustentável da Produção de Plantas Aromáticas e Medicinais e Projeto PRODER n.º 46207 - Adaptação cultural de hortelã-vulgar e stevia
Nitrogen content in above-ground plant parts as an aid to establish more accurate fertilizer-nitrogen recommendations for grapevine
Nitrogen is the nutrient applied most frequently as fertilizer in annual and perennial crops. In grapevine, nitrogen determines the vigor and yield of vine and several attributes of must quality (Akin et al., 2012; Pérez-Alvaréz et al., 2013). The close relationship between nitrogen application, vine performance and the quality of wine requires the rational use of fertilizer-N. In addition, the excessive use of fertilizer-N may cause environmental damage (Powlson, 1993). The current recommendation systems for vine are usually based on plant analysis complemented by soil testing. These tools are important but insufficient to provide quantified rates of nutrients to apply. To increase the accuracy of the fertilization programs, data on nutrient content and dynamic in plant tissues may be helpful. In this work, nutrient content in different vine parts (leaves, canes, cordons and trunk) and at different dates (from September 14th to November 28th) was determined to understand the fate of the nutrients at the end of the growing season as a mean of increasing precision of the fertilizer recommendation system. In this extended abstract, it will be presented data on nitrogen content and dynamic in those plant tissues and dates
The Safe-Port project: an approach to port surveillance and protection
SAFE-PORT is a recently started project addressing the complex issue of determining the best configurations of resources for harbour and port surveillance and protection. More specifically, the main goal is to find, for any given scenario, an adequate set of configuration solutions — i.e., number and type of sensors and equipments, their locations and operating modes, the corresponding personnel and other support resources — that maximize protection over a specific area.
The project includes research and development of sensors models, novel algorithms for optimization and decision support, and a computer-based decision support system (DSS) to assist decision makers in that task. It includes also the development of a simulation environment for modelling relevant aspects of the scenario (including sensors used for surveillance, platforms, threats and the environment), capable to incorporate data from field-trials, used to test and validate solutions proposed by the DSS. Test cases will consider the use of intelligent agents to model the behaviour of threats and of NATO forces in a realistic way, following experts’ definitions and parameters
Growth and nitrogen recovery in the above-ground biomass of eleven self-reseeding annual legumes grown in a rainfed olive orchard
Most of the traditional dry-farmed olive orchards of the NE of Portugal are planted in shallow soils on sloping terrain. The olive yields obtained are usually low, due to the severe environmental constraints under which these orchards are grown. Growing olive trees in such hard conditions, may recommend the management of the orchards as organic, a low-input farming system from which the farmer profit can arise from the appreciation of the price of the olive oil. The natural soil fertility of these orchards is usually very low, being nitrogen the most limiting nutrient to the growth of the trees (Rodrigues et al., 2011). Objectively, to manage these orchards as organic and to maintain the soil fertility and the tree nutritional status in an acceptable level, there is a single option: the introduction of legume species as cover crops. Legumes can access atmospheric N2, due to the symbiotic relationship that they can establish with nitrogen-fixing bacteria (Russelle, 2008). In this work eleven self-reseeding annual legumes were introduced in a rainfed olive orchard in order to test their suitability to be used as cover crops. The legume species/varieties were grown as pure stand and managed without grazing, since currently the farmers of the region are not raising animals. The cover crops were shown in September 2009, and data on dry matter yield, nitrogen recovery, ground cover percentage, persistence of the sown species, …, are recorded for four consecutive growing seasons
The effect of different winter cover crops on sorghum nutritional status and dry matter yield
Growing winter cover crops has a great agroecological meaning, since it allow maintaining the residual inorganic N in the soil/plant system, thus avoiding leaching of N (Rodrigues et al., 2002). As winter cover crops, it can be grown diverse species (Jensen, 1992). If legume species were used, they can access atmospheric N through the establishment of a symbiotic relationship with N-fixing bacteria (Russelle, 2008). Thus, the winter leguminous cover crops can have a dual role: to uptake residual inorganic N; and promoting the growth of the following crop through a green manuring effect, which may reduce the need for expensive N fertilizers. Lupine (Lupinus albus) appears as a suitable legume species to be grown in this region, since it presents high growth rates in winter and a great ability to fix N (Rodrigues et al., 2013). In this work, the use of lupine as a winter cover crop was compared to small grains and natural vegetation (weeds) by measuring their effect on irrigated sorghum grown as a summer crop. The effect of the different winter cover crops was evaluated by comparing sorghum dry matter yield, plant N nutritional status and N recovery by sorghum plants
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