ANTONIO NETO SANTOS - Academia.edu (original) (raw)

Papers by ANTONIO NETO SANTOS

Research paper thumbnail of Aspectos Energéticos e Acústicos Dos Vãos Envidraçados

RESUMO Os vãos envidraçados desempenham um papel primordial na obtenção da qualidade de vida e co... more RESUMO Os vãos envidraçados desempenham um papel primordial na obtenção da qualidade de vida e conforto no interior dos edifícios. Os aspectos fundamentais que afectam o desempenho dos vãos envidraçados são: (i) as características físicas do vão considerado como um conjunto que integra diferentes componentes, onde cada uma desempenha funções específicas; (ii) a interface física na qual os vãos envidraçados se integram, e (iii) a influência dos envidraçados no conforto ambiental dos ocupantes. Para além da necessidade de controlar os fluxos energéticos e a transmissão sonora, deseja-se que os vãos envidraçados permitam a entrada de luz natural sem causarem encandeamento, que resistam às infiltrações da água das chuvas e que permitam um aproveitamento controlado da radiação solar. Todas estas exigências funcionais fazem com que o projecto e a avaliação do desempenho dos vãos envidraçados constituam processos complexos e multidisciplinares.

Research paper thumbnail of Wood and pulp properties of two Eucalyptus globulus wood samples

This paper reports experimental data about wood chemical composition (extractives and lignin cont... more This paper reports experimental data about wood chemical composition (extractives and lignin content), fibre characteristics, kraft cooking behaviour and papermaking potential of two wood samples of Eucalyptus globulus (one industrial chip sample and another obtained from a clone tree). The samples were submitted to the kraft cooking and bleaching processes in order to evaluate its pulping potential. The experimental results showed that the clone tree requires milder cooking conditions and exhibits higher pulp yield. The pulp fibres obtained from the clone have higher fibre length and fibre width and lower coarseness, which give higher fibre flexibility and collapsibility. In consequence, structural, mechanical and optical properties of paper are significantly different. In addition, we observed that the fibres from the clone tree are weaker than the corresponding fibres from the industrial sample.

Research paper thumbnail of Re-ecologizar lo urbano": agricultura urbana e historia ambiental

Historia contemporánea, 2009

Resumen: En este artículo se propone una revisión de las aportaciones que la historia ambiental u... more Resumen: En este artículo se propone una revisión de las aportaciones que la historia ambiental urbana ha realizado en los últimos años. Ante la crisis ecológica global, la ciudad aparece como un espacio que consume energía y materia. Existen estrategias productivas que pueden convertir la ciudad en un sistema más sustentable? Existen experiencias en el mundo que han recuperado la ciudad como espacio para la producción agraria, redefiniendo la dimensión sustentable de los espacios urbanos. En este sentido, la segunda parte del artículo presenta los resultados de la Agricultura Urbana en La Habana, Cuba. Este tipo de agricultura ha permitido asegurar los niveles de abastecimiento alimentario urbano y la soberanía de los productores agrícolas en el ámbito urbano. Fue una medida de urgencia ante los problemas de abastecimiento para la economía cubana pero convirtió la ciudad en un modelo urbano con más sustentabilidad socioambiental.

Research paper thumbnail of Challenges in designing seamless-learning scenarios: affective and emotional effects on external representations

International Journal of Mobile Learning and Organisation, 2011

In this paper, we revisit different theoretical and conceptual issues that have been influencing ... more In this paper, we revisit different theoretical and conceptual issues that have been influencing the design of educational technology artefacts. In particular, we take into consideration recent perspectives in cognitive science that acknowledge the important effects of external representations (ERs) in learning and discuss the challenges regarding the applicability of these ideas in connection to seamless-learning environments. Extending the previous work revised here, this paper suggests that in order to further understand the nature of learning in these novel contexts, research needs to investigate how socioaffective factors come to the fore and influence the co-construction and use of ERs 'in the wild'. AU: Kindly check the insertion of 'Guimarães 4800-058' and 'Kalmar SE-391 82' in the affiliation.

Research paper thumbnail of Desenvolvimento e análise de jogo educativo para crianças visando à prevenção de doenças parasitológicas

Interface - Comunicação, Saúde, Educação, 2007

As crianças brasileiras, sobretudo de famílias de baixa renda, apresentam uma prevalência signifi... more As crianças brasileiras, sobretudo de famílias de baixa renda, apresentam uma prevalência significativa de parasitoses intestinais. As intervenções educativas podem estimular ações que contribuam para a prevenção deste tipo de infecção. Os jogos educativos são uma ferramenta lúdica que fazem do educando um agente ativo no processo. Foi desenvolvido um jogo de tabuleiro para ensinar hábitos de saúde que promovem a prevenção de parasitoses intestinais. O jogo foi testado em 98 escolares entre sete e 13 anos, aplicando pré e pós-teste. Os resultados do pós-teste foram significativamente superiores aos do pré-teste. Os dados indicam que as crianças que realizaram o jogo apresentaram um acréscimo significativo no conhecimento que possuíam sobre hábitos de saúde que previnem parasitoses intestinais. Todavia, parte dos sujeitos apresentavam conhecimento prévio dos conteúdos abordados, e as crianças mais velhas tenderam a ter um pior desempenho.

Research paper thumbnail of Estudo da aptidão da Acacia melanoxylon R. Br. para a produção de pasta e da aplicação de espectroscopia de infravermelho próximo

Os trabalhos são apresentados no formato final dos artigos publicados, aceites ou submetidos para... more Os trabalhos são apresentados no formato final dos artigos publicados, aceites ou submetidos para publicação. 1.3.1: Site, tree and within-tree variation of blackwood (Acacia melanoxylon (R. Br.) wood properties. Correlation of density at 12% with the mechanical properties

Research paper thumbnail of Stenosoma stephenseni sp. n. (Isopoda, Idoteidae), from the southwestern Mediterranean, with a note on the nomenclatural status of Synisoma Collinge, 1917

Research paper thumbnail of (1right-arrow6)-beta-D-Glucan as Cell Wall Receptor for Pichia membranifaciens Killer Toxin

Applied and …, 2000

The killer toxin from Pichia membranifaciens CYC 1106, a yeast isolated from fermenting olive bri... more The killer toxin from Pichia membranifaciens CYC 1106, a yeast isolated from fermenting olive brines, binds primarily to the (1 6)- -D-glucan of the cell wall of a sensitive yeast (Candida boidinii IGC 3430). The (1 6)- -D-glucan was purified from cell walls of C. boidinii by alkali and hot-...

Research paper thumbnail of MtDNA and nuclear data reveal patterns of low genetic differentiation for the isopods Stenosoma lancifer and Stenosoma acuminatum, with low dispersal ability along the northeast Atlantic coast

Evidence for a general lack of genetic differentiation of intertidal invertebrate assemblages in ... more Evidence for a general lack of genetic differentiation of intertidal invertebrate assemblages in the North Atlantic, based on mtDNA sequence variation, has been interpreted as resulting from recent colonization following the Last Glacial Maximum. In the present study, the phylogeographic patterns of one nuclear and one mtDNA gene fragments of two isopods, Stenosoma lancifer (Miers, 1881) and Stenosoma acuminatum Leach, 1814, from the northeast Atlantic were investigated. These organisms have direct development, which makes them poor dispersers, and are therefore expected to maintain signatures of past historical events in their genomes. Lack of genetic structure, significant deviations from neutrality and star-like haplotype networks have been observed for both mtDNA and nuclear markers of S. lancifer, as well as for the mtDNA of S. acuminatum. No sequence variation was observed for the nuclear gene fragment of S. acuminatum. These results suggest a scenario of recent colonization and demographic expansion and/or high population connectivity driven by ocean currents and sporadic long-distance dispersal through rafting.

Research paper thumbnail of Forecasting the poleward range expansion of an intertidal species driven by climate alterations

Accurate distributional models can be used to reliably predict the response of organisms to clima... more Accurate distributional models can be used to reliably predict the response of organisms to climatic changes. Though such models have been extensively applied to terrestrial organisms, they have hardly ever been applied to the marine environment. Recent changes in the distribution of the marine gastropod Patella rustica (L.) were previously modelled with Classification and Regression Tree (CART) and the results revealed that increases in temperature were the major driver of those changes. However, the accuracy scores during the validation of the model were unsatisfactory, preventing its use for forecasting purposes. To fulfil this objective, in the present study a more robust method, Artificial Neural Network (ANN), was employed to produce a model suited to forecasting changes in the distribution of P. rustica. Results confirmed that the ANN model behaved better than the CART, and that it could be used for forecasting future distributional scenarios. The model forecasts that by the 2020s P. rustica is likely to expand its range at least 1000 km northwards. These results should be interpreted with caution considering the dispersal limitations of this species, but if such an expansion took place, major changes in the colonized ecosystems are expected due to the key role of limpets in intertidal communities.

Research paper thumbnail of Phylogeography of the marine isopod Stenosoma nadejda (Rezig, 1989) in North African Atlantic and western Mediterranean coasts reveals complex differentiation patterns and a new species

The transition zone between the Mediterranean and Atlantic basins has been extensively addressed ... more The transition zone between the Mediterranean and Atlantic basins has been extensively addressed in phylogeographical studies of marine species. However, biases exist towards the analysis of highly dispersive species, and there is a higher sampling effort in European coasts compared to North Africa. This may be hindering a detailed understanding of the historical and contemporary processes that shaped patterns of population genetic structure in the region. In the present study, we investigated the phylogeographical and phylogenetic patterns of mitochondrial cytochrome c oxidase subunit I sequences from a species with direct development and low dispersal abilities, Stenosoma nadejda (Rezig, 1989). The study area included 13 localities along the Atlantic and Mediterranean North African coasts, as well as the Alboran Sea. A new Stenosoma species, from the coasts of Algeria and Alboran Island, was discovered. For S. nadejda, phylogeographical analyses revealed three distinct clades: one in the Iberian Atlantic plus the Alboran Sea, one in the western Mediterranean, and another in the Atlantic coast of Africa. Haplotypes from the Alboran Island were more related to those from the western Mediterranean coast (east of the Almeria-Oran Front). Given the strong differentiation, it is probable that this species survived in multiple glacial refugia during the Pleistocenic glaciations.

Research paper thumbnail of TWO METHODS FOR TREE VOLUME ESTIMATION OF Acacia melanoxylon IN PORTUGAL

FLORESTA, 2011

Two models were developed to evaluate total volume under and over-bark of Blackwood (Acacia melan... more Two models were developed to evaluate total volume under and over-bark of Blackwood (Acacia melanoxylon R. Br.) stand trees. By variance analysis regarding volume with and without bark it was confirmed that trees age is responsible for 48 to 50% of its volumetric behaviour. Considered the averages of those variables and regarding the three homogeneous groups of the studied sites, a single model type was used (v=β 1 d β2 h β3) for estimating volumes. The critical errors are between 72 and 195 dm 3 under-bark, and 82 and 212dm 3 over-bark. The model that uses sites as dummy variables to the estimation of stand tree volumes is the same, and this method performs maximum expected errors with values of 155 dm 3 (under-bark) and 169dm 3 (over-bark), to mean maximum volumes of 1362 and 1459 dm 3 respectively. The use of dummy variables is a more expedite and rapid modelling method, and its maximum expected errors perform lower values.

Research paper thumbnail of Calibrated heat-pulse method for the assessment of maize water uptake

Scientia Agricola, 2000

Plant water requirements are important aspects of crop production to be determined in the field, ... more Plant water requirements are important aspects of crop production to be determined in the field, in order to judiciously manage crop water usage. Water uptake by field grown maize (Zea mays L.), under well-watered conditions was verified with the heatpulse system. The temperature difference between two radially inserted thermocouples, one 9 mm above and the other 4 mm below a heater piercing the maize stem, was measured every 0.3 seconds following emission of a heat-pulse. Comparisons of the heat-pulse system outputs, lysimetric measurement and transpiration model estimates were monitored on an hourly and daily basis. At normal and low atmospheric demand daily and hourly values of heat-pulse outputs and lysimetric measurement showed good agreement. Hourly agreement of a modified Penman-Monteith energy balance equation estimate and heat-pulse outputs showed accordance between measurement of sap flow and the plant water-loss theory. Study of the relationship between maize canopy water loss rate and heat velocity in the stem showed that these two parameters were proportional and a calibration factor of 1.51 for full soil foliage coverage was verified.

Research paper thumbnail of Variation of some wood macroscopic properties along the stem of Acacia melanoxylon R. Br. adult trees in Portugal

Forest Systems, 2013

Acacia is a woody genus with more than 1000 species occurring naturally in arid areas of Australi... more Acacia is a woody genus with more than 1000 species occurring naturally in arid areas of Australia, Asia, Africa, and tropical America (Playford et al., 1991). During the eighteen and nineteen centuries some native acacia from Australia were introduced in several countries, e.g. Acacia mangium Willd was planted in Brazil in order to profit by its fast growth rate and rectilinear stem. Nowadays, several acacia species are exploited worldwide for firewood, pulpwood, tannins and other colouring extractives, carpentry, forage, as well as ornamental trees and sloping banks (Playford et al., 1991). Acacia melanoxylon R. Br. is distributed in Australia along the east coast, from southern Tasmania to Atherton in Queensland, and is a prized native tree for furniture. This acacia, also named Blackwood, has been extensively utilized in South Africa for fuel, shelter belts, fence droppers, building structures and mine props, and high quality Blackwood stems are highly rated for quality sawn products (Playford et al., 1991). In the beginning of the twentieth century various acacia species were introduced in Portugal in order to colonize dry and poor sandy soils along the coast. The country has revealed good ecological conditions for the development of some of them, particularly A. melanoxylon and A. dealbata and, nowadays, there are several spontaneous stands dispersed by natural dissemination in all the territory. So far, because the control of these alien invader species using chemical and mechanical methods has not been done with satisfactory results (Tavares et al., 1999), nowadays Acacia melanoxylon is one of the most disseminated wattle species in north and west of Portugal. Here the national forest inventory count about 4,000 hectares of different acacia species and more 6,300 hectares in Azores and

Research paper thumbnail of Variation of wood density and mechanical properties of blackwood (Acacia melanoxylon R. Br.)

The variation of wood density and mechanical properties with site, tree and within tree (longitud... more The variation of wood density and mechanical properties with site, tree and within tree (longitudinal and radial) were studied for blackwood (Acacia melanoxylon R. Br.) grown in four sites in Portugal. Twenty trees were randomly selected (40 cm dbh class, 33-51 years of age), sampled at three stem height levels (5%, 35% and 65% of tree height) and three radial positions (10%, 50% and 90% of radius). They were further tested for air-dry density at 12% moisture content, bending strength (MOR), modulus of elasticity (MOE) and compression strength parallel to grain (CS), using ISO standards. The overall mean properties of blackwood were: 654 kg m À3 density, 139 N mm À2 MOR, 141 Â 10 2 N mm À2 MOE and 61 N mm À2 CS. Site was not a significant source of variation for all wood properties. The variation between individual trees was the most important. Within the tree, the radial variation was highly significant for all traits, while the longitudinal variation was only significant for density. The correlation of density with the mechanical properties was moderate. Blackwood showed potential for being an alternative species to supply the industry with valuable hardwood timber. The significant differences found between the trees demonstrate the possibility of selection and improvement for increased wood quality.

Research paper thumbnail of Node-Depth Encoding with recombination for multi-objective Evolutionary Algorithm to solve loss reduction problem in large-scale distribution systems

ABSTRACT Power loss reduction problem can be achieved by an adequate Distribution System Reconfig... more ABSTRACT Power loss reduction problem can be achieved by an adequate Distribution System Reconfiguration (DSR). Usually DSR for power loss reduction is formulated as a nonlinear, multi-objective and multi-constrained optimization problem, containing thousands of constraints equations for large-scale networks. As a consequence, to find an adequate solution for such problem is computationally complex. Recently a practical and efficient approach to solve this problem which overcomes such a hurdle was developed. This approach, called MEAN, combines a multi-objective Evolutionary Algorithm (EA), based on subpopulations tables, with a new tree encoding, named Node-Depth Encoding (NDE). This paper presents a new genetic recombination operator, named Evolutionary History Recombination NDE operator, which improves the MEAN performance to solve the loss reduction problem in large-scale networks. Tests with large networks show that with the new operator the MEAN can find network configurations with loss reduction of 29.57% for networks with 5,166 switches. This result is surprising since the practitioners used to expect at most a 10% reduction by means of DSR.

Research paper thumbnail of Aspectos Energéticos e Acústicos Dos Vãos Envidraçados

RESUMO Os vãos envidraçados desempenham um papel primordial na obtenção da qualidade de vida e co... more RESUMO Os vãos envidraçados desempenham um papel primordial na obtenção da qualidade de vida e conforto no interior dos edifícios. Os aspectos fundamentais que afectam o desempenho dos vãos envidraçados são: (i) as características físicas do vão considerado como um conjunto que integra diferentes componentes, onde cada uma desempenha funções específicas; (ii) a interface física na qual os vãos envidraçados se integram, e (iii) a influência dos envidraçados no conforto ambiental dos ocupantes. Para além da necessidade de controlar os fluxos energéticos e a transmissão sonora, deseja-se que os vãos envidraçados permitam a entrada de luz natural sem causarem encandeamento, que resistam às infiltrações da água das chuvas e que permitam um aproveitamento controlado da radiação solar. Todas estas exigências funcionais fazem com que o projecto e a avaliação do desempenho dos vãos envidraçados constituam processos complexos e multidisciplinares.

Research paper thumbnail of Wood and pulp properties of two Eucalyptus globulus wood samples

This paper reports experimental data about wood chemical composition (extractives and lignin cont... more This paper reports experimental data about wood chemical composition (extractives and lignin content), fibre characteristics, kraft cooking behaviour and papermaking potential of two wood samples of Eucalyptus globulus (one industrial chip sample and another obtained from a clone tree). The samples were submitted to the kraft cooking and bleaching processes in order to evaluate its pulping potential. The experimental results showed that the clone tree requires milder cooking conditions and exhibits higher pulp yield. The pulp fibres obtained from the clone have higher fibre length and fibre width and lower coarseness, which give higher fibre flexibility and collapsibility. In consequence, structural, mechanical and optical properties of paper are significantly different. In addition, we observed that the fibres from the clone tree are weaker than the corresponding fibres from the industrial sample.

Research paper thumbnail of Re-ecologizar lo urbano": agricultura urbana e historia ambiental

Historia contemporánea, 2009

Resumen: En este artículo se propone una revisión de las aportaciones que la historia ambiental u... more Resumen: En este artículo se propone una revisión de las aportaciones que la historia ambiental urbana ha realizado en los últimos años. Ante la crisis ecológica global, la ciudad aparece como un espacio que consume energía y materia. Existen estrategias productivas que pueden convertir la ciudad en un sistema más sustentable? Existen experiencias en el mundo que han recuperado la ciudad como espacio para la producción agraria, redefiniendo la dimensión sustentable de los espacios urbanos. En este sentido, la segunda parte del artículo presenta los resultados de la Agricultura Urbana en La Habana, Cuba. Este tipo de agricultura ha permitido asegurar los niveles de abastecimiento alimentario urbano y la soberanía de los productores agrícolas en el ámbito urbano. Fue una medida de urgencia ante los problemas de abastecimiento para la economía cubana pero convirtió la ciudad en un modelo urbano con más sustentabilidad socioambiental.

Research paper thumbnail of Challenges in designing seamless-learning scenarios: affective and emotional effects on external representations

International Journal of Mobile Learning and Organisation, 2011

In this paper, we revisit different theoretical and conceptual issues that have been influencing ... more In this paper, we revisit different theoretical and conceptual issues that have been influencing the design of educational technology artefacts. In particular, we take into consideration recent perspectives in cognitive science that acknowledge the important effects of external representations (ERs) in learning and discuss the challenges regarding the applicability of these ideas in connection to seamless-learning environments. Extending the previous work revised here, this paper suggests that in order to further understand the nature of learning in these novel contexts, research needs to investigate how socioaffective factors come to the fore and influence the co-construction and use of ERs 'in the wild'. AU: Kindly check the insertion of 'Guimarães 4800-058' and 'Kalmar SE-391 82' in the affiliation.

Research paper thumbnail of Desenvolvimento e análise de jogo educativo para crianças visando à prevenção de doenças parasitológicas

Interface - Comunicação, Saúde, Educação, 2007

As crianças brasileiras, sobretudo de famílias de baixa renda, apresentam uma prevalência signifi... more As crianças brasileiras, sobretudo de famílias de baixa renda, apresentam uma prevalência significativa de parasitoses intestinais. As intervenções educativas podem estimular ações que contribuam para a prevenção deste tipo de infecção. Os jogos educativos são uma ferramenta lúdica que fazem do educando um agente ativo no processo. Foi desenvolvido um jogo de tabuleiro para ensinar hábitos de saúde que promovem a prevenção de parasitoses intestinais. O jogo foi testado em 98 escolares entre sete e 13 anos, aplicando pré e pós-teste. Os resultados do pós-teste foram significativamente superiores aos do pré-teste. Os dados indicam que as crianças que realizaram o jogo apresentaram um acréscimo significativo no conhecimento que possuíam sobre hábitos de saúde que previnem parasitoses intestinais. Todavia, parte dos sujeitos apresentavam conhecimento prévio dos conteúdos abordados, e as crianças mais velhas tenderam a ter um pior desempenho.

Research paper thumbnail of Estudo da aptidão da Acacia melanoxylon R. Br. para a produção de pasta e da aplicação de espectroscopia de infravermelho próximo

Os trabalhos são apresentados no formato final dos artigos publicados, aceites ou submetidos para... more Os trabalhos são apresentados no formato final dos artigos publicados, aceites ou submetidos para publicação. 1.3.1: Site, tree and within-tree variation of blackwood (Acacia melanoxylon (R. Br.) wood properties. Correlation of density at 12% with the mechanical properties

Research paper thumbnail of Stenosoma stephenseni sp. n. (Isopoda, Idoteidae), from the southwestern Mediterranean, with a note on the nomenclatural status of Synisoma Collinge, 1917

Research paper thumbnail of (1right-arrow6)-beta-D-Glucan as Cell Wall Receptor for Pichia membranifaciens Killer Toxin

Applied and …, 2000

The killer toxin from Pichia membranifaciens CYC 1106, a yeast isolated from fermenting olive bri... more The killer toxin from Pichia membranifaciens CYC 1106, a yeast isolated from fermenting olive brines, binds primarily to the (1 6)- -D-glucan of the cell wall of a sensitive yeast (Candida boidinii IGC 3430). The (1 6)- -D-glucan was purified from cell walls of C. boidinii by alkali and hot-...

Research paper thumbnail of MtDNA and nuclear data reveal patterns of low genetic differentiation for the isopods Stenosoma lancifer and Stenosoma acuminatum, with low dispersal ability along the northeast Atlantic coast

Evidence for a general lack of genetic differentiation of intertidal invertebrate assemblages in ... more Evidence for a general lack of genetic differentiation of intertidal invertebrate assemblages in the North Atlantic, based on mtDNA sequence variation, has been interpreted as resulting from recent colonization following the Last Glacial Maximum. In the present study, the phylogeographic patterns of one nuclear and one mtDNA gene fragments of two isopods, Stenosoma lancifer (Miers, 1881) and Stenosoma acuminatum Leach, 1814, from the northeast Atlantic were investigated. These organisms have direct development, which makes them poor dispersers, and are therefore expected to maintain signatures of past historical events in their genomes. Lack of genetic structure, significant deviations from neutrality and star-like haplotype networks have been observed for both mtDNA and nuclear markers of S. lancifer, as well as for the mtDNA of S. acuminatum. No sequence variation was observed for the nuclear gene fragment of S. acuminatum. These results suggest a scenario of recent colonization and demographic expansion and/or high population connectivity driven by ocean currents and sporadic long-distance dispersal through rafting.

Research paper thumbnail of Forecasting the poleward range expansion of an intertidal species driven by climate alterations

Accurate distributional models can be used to reliably predict the response of organisms to clima... more Accurate distributional models can be used to reliably predict the response of organisms to climatic changes. Though such models have been extensively applied to terrestrial organisms, they have hardly ever been applied to the marine environment. Recent changes in the distribution of the marine gastropod Patella rustica (L.) were previously modelled with Classification and Regression Tree (CART) and the results revealed that increases in temperature were the major driver of those changes. However, the accuracy scores during the validation of the model were unsatisfactory, preventing its use for forecasting purposes. To fulfil this objective, in the present study a more robust method, Artificial Neural Network (ANN), was employed to produce a model suited to forecasting changes in the distribution of P. rustica. Results confirmed that the ANN model behaved better than the CART, and that it could be used for forecasting future distributional scenarios. The model forecasts that by the 2020s P. rustica is likely to expand its range at least 1000 km northwards. These results should be interpreted with caution considering the dispersal limitations of this species, but if such an expansion took place, major changes in the colonized ecosystems are expected due to the key role of limpets in intertidal communities.

Research paper thumbnail of Phylogeography of the marine isopod Stenosoma nadejda (Rezig, 1989) in North African Atlantic and western Mediterranean coasts reveals complex differentiation patterns and a new species

The transition zone between the Mediterranean and Atlantic basins has been extensively addressed ... more The transition zone between the Mediterranean and Atlantic basins has been extensively addressed in phylogeographical studies of marine species. However, biases exist towards the analysis of highly dispersive species, and there is a higher sampling effort in European coasts compared to North Africa. This may be hindering a detailed understanding of the historical and contemporary processes that shaped patterns of population genetic structure in the region. In the present study, we investigated the phylogeographical and phylogenetic patterns of mitochondrial cytochrome c oxidase subunit I sequences from a species with direct development and low dispersal abilities, Stenosoma nadejda (Rezig, 1989). The study area included 13 localities along the Atlantic and Mediterranean North African coasts, as well as the Alboran Sea. A new Stenosoma species, from the coasts of Algeria and Alboran Island, was discovered. For S. nadejda, phylogeographical analyses revealed three distinct clades: one in the Iberian Atlantic plus the Alboran Sea, one in the western Mediterranean, and another in the Atlantic coast of Africa. Haplotypes from the Alboran Island were more related to those from the western Mediterranean coast (east of the Almeria-Oran Front). Given the strong differentiation, it is probable that this species survived in multiple glacial refugia during the Pleistocenic glaciations.

Research paper thumbnail of TWO METHODS FOR TREE VOLUME ESTIMATION OF Acacia melanoxylon IN PORTUGAL

FLORESTA, 2011

Two models were developed to evaluate total volume under and over-bark of Blackwood (Acacia melan... more Two models were developed to evaluate total volume under and over-bark of Blackwood (Acacia melanoxylon R. Br.) stand trees. By variance analysis regarding volume with and without bark it was confirmed that trees age is responsible for 48 to 50% of its volumetric behaviour. Considered the averages of those variables and regarding the three homogeneous groups of the studied sites, a single model type was used (v=β 1 d β2 h β3) for estimating volumes. The critical errors are between 72 and 195 dm 3 under-bark, and 82 and 212dm 3 over-bark. The model that uses sites as dummy variables to the estimation of stand tree volumes is the same, and this method performs maximum expected errors with values of 155 dm 3 (under-bark) and 169dm 3 (over-bark), to mean maximum volumes of 1362 and 1459 dm 3 respectively. The use of dummy variables is a more expedite and rapid modelling method, and its maximum expected errors perform lower values.

Research paper thumbnail of Calibrated heat-pulse method for the assessment of maize water uptake

Scientia Agricola, 2000

Plant water requirements are important aspects of crop production to be determined in the field, ... more Plant water requirements are important aspects of crop production to be determined in the field, in order to judiciously manage crop water usage. Water uptake by field grown maize (Zea mays L.), under well-watered conditions was verified with the heatpulse system. The temperature difference between two radially inserted thermocouples, one 9 mm above and the other 4 mm below a heater piercing the maize stem, was measured every 0.3 seconds following emission of a heat-pulse. Comparisons of the heat-pulse system outputs, lysimetric measurement and transpiration model estimates were monitored on an hourly and daily basis. At normal and low atmospheric demand daily and hourly values of heat-pulse outputs and lysimetric measurement showed good agreement. Hourly agreement of a modified Penman-Monteith energy balance equation estimate and heat-pulse outputs showed accordance between measurement of sap flow and the plant water-loss theory. Study of the relationship between maize canopy water loss rate and heat velocity in the stem showed that these two parameters were proportional and a calibration factor of 1.51 for full soil foliage coverage was verified.

Research paper thumbnail of Variation of some wood macroscopic properties along the stem of Acacia melanoxylon R. Br. adult trees in Portugal

Forest Systems, 2013

Acacia is a woody genus with more than 1000 species occurring naturally in arid areas of Australi... more Acacia is a woody genus with more than 1000 species occurring naturally in arid areas of Australia, Asia, Africa, and tropical America (Playford et al., 1991). During the eighteen and nineteen centuries some native acacia from Australia were introduced in several countries, e.g. Acacia mangium Willd was planted in Brazil in order to profit by its fast growth rate and rectilinear stem. Nowadays, several acacia species are exploited worldwide for firewood, pulpwood, tannins and other colouring extractives, carpentry, forage, as well as ornamental trees and sloping banks (Playford et al., 1991). Acacia melanoxylon R. Br. is distributed in Australia along the east coast, from southern Tasmania to Atherton in Queensland, and is a prized native tree for furniture. This acacia, also named Blackwood, has been extensively utilized in South Africa for fuel, shelter belts, fence droppers, building structures and mine props, and high quality Blackwood stems are highly rated for quality sawn products (Playford et al., 1991). In the beginning of the twentieth century various acacia species were introduced in Portugal in order to colonize dry and poor sandy soils along the coast. The country has revealed good ecological conditions for the development of some of them, particularly A. melanoxylon and A. dealbata and, nowadays, there are several spontaneous stands dispersed by natural dissemination in all the territory. So far, because the control of these alien invader species using chemical and mechanical methods has not been done with satisfactory results (Tavares et al., 1999), nowadays Acacia melanoxylon is one of the most disseminated wattle species in north and west of Portugal. Here the national forest inventory count about 4,000 hectares of different acacia species and more 6,300 hectares in Azores and

Research paper thumbnail of Variation of wood density and mechanical properties of blackwood (Acacia melanoxylon R. Br.)

The variation of wood density and mechanical properties with site, tree and within tree (longitud... more The variation of wood density and mechanical properties with site, tree and within tree (longitudinal and radial) were studied for blackwood (Acacia melanoxylon R. Br.) grown in four sites in Portugal. Twenty trees were randomly selected (40 cm dbh class, 33-51 years of age), sampled at three stem height levels (5%, 35% and 65% of tree height) and three radial positions (10%, 50% and 90% of radius). They were further tested for air-dry density at 12% moisture content, bending strength (MOR), modulus of elasticity (MOE) and compression strength parallel to grain (CS), using ISO standards. The overall mean properties of blackwood were: 654 kg m À3 density, 139 N mm À2 MOR, 141 Â 10 2 N mm À2 MOE and 61 N mm À2 CS. Site was not a significant source of variation for all wood properties. The variation between individual trees was the most important. Within the tree, the radial variation was highly significant for all traits, while the longitudinal variation was only significant for density. The correlation of density with the mechanical properties was moderate. Blackwood showed potential for being an alternative species to supply the industry with valuable hardwood timber. The significant differences found between the trees demonstrate the possibility of selection and improvement for increased wood quality.

Research paper thumbnail of Node-Depth Encoding with recombination for multi-objective Evolutionary Algorithm to solve loss reduction problem in large-scale distribution systems

ABSTRACT Power loss reduction problem can be achieved by an adequate Distribution System Reconfig... more ABSTRACT Power loss reduction problem can be achieved by an adequate Distribution System Reconfiguration (DSR). Usually DSR for power loss reduction is formulated as a nonlinear, multi-objective and multi-constrained optimization problem, containing thousands of constraints equations for large-scale networks. As a consequence, to find an adequate solution for such problem is computationally complex. Recently a practical and efficient approach to solve this problem which overcomes such a hurdle was developed. This approach, called MEAN, combines a multi-objective Evolutionary Algorithm (EA), based on subpopulations tables, with a new tree encoding, named Node-Depth Encoding (NDE). This paper presents a new genetic recombination operator, named Evolutionary History Recombination NDE operator, which improves the MEAN performance to solve the loss reduction problem in large-scale networks. Tests with large networks show that with the new operator the MEAN can find network configurations with loss reduction of 29.57% for networks with 5,166 switches. This result is surprising since the practitioners used to expect at most a 10% reduction by means of DSR.