1,609 research outputs found
Mineralogical insights to identify göktepe marble in the sculptural program of quinta das longas villa (Lusitania)
This archaeometric study is focused on the marble used in a group of fragmented sculptures found at the Roman villa of Quinta das Longas (Elvas, Portugal). Dating from the 4th century AD, the pieces are of remarkable quality and correspond to ideal and mythological figures from several iconographic cycles. The numerous fragments, all of very fine-grained white marble, are associated with the ornamentation of an impressive nymphaeum of the villa. Their high level of sculpture technique and style, the models followed and their similar typology to other well-known parallels raise the hypothesis of being linked with Aphrodisian workshops. Using a well-established multi-method approach, with Optical microscopy, X-ray Powder Diffraction (XRPD), qualitative and quantitative cathodoluminescence (CL) by CL-Optical and CL-SEM, and stable C and O isotopic and trace element analytical techniques (IRMS and ICP-AES), together with complementary parameters obtained from electron paramagnetic resonance (EPR) and87Sr/86Sr isotopes, the marble provenance can be identified with certainty. The results all point to the best quality of white Göktepe marble, confirming the stylistic connection to the ancient Carian sculptors. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Scientific integrity: Revisiting the concept
info:eu-repo/semantics/publishedVersio
Morphological and physiological responses of strawberry to a biostimulant and calcium application
info:eu-repo/semantics/publishedVersio
Metabolic profile in growing buffalo heifers fed diet with different energy content
Aim of this study was to verify the relation among the mediators and indicators of nutritional status like insulin, glucagon, urea, cholesterol, triglycerides and total proteins in growing buffalo heifers, fed diets with different energy density. 12 Murrah heifers were randomly allocated into two dietary treatments (High, Group H; Low, Group L) that differed in energetic levels (Group H: 5.8 UFL/d; Group L: 3.6 UFL/d). Every 30 days, for a total of five times, blood samples were collected at 08.00 h, before feeding, from the jugular vein in vacutainer tubes and analysed to determine metabolic profile. Data on haematic constants were analysed by ANOVA for repeated measures with treatment as the main factor. Low energy availability and low NSC reduced the glucose and insulin and increased glucagone and urea blood levels. The increase of NSC in the diet of group H during the experiment may caused a reduction of the fibre digestibility after the period of adaptation of the rumen microflora and, as a paradox effect, suffered for an energetic lack with a subsequent activation of lipolysis and mobilization of their body reserves. Liver and muscular synthesis increase in group with a high energy availability
A brief review of fatigue design criteria on offshore wind turbine support structures
In this paper, a brief review of the main fatigue design criteria and some advanced fatigue approaches applied to offshore structures (e.g. offshore wind turbines) are presented. It is extremely important to understand the fatigue phenomenon and how it affects structures since offshore structures are constantly submitted to cyclic loading and corrosive attacks that aggravate the problem. All the influencing factors and approaches used during the design phase are also discussed
Controlo da altura de plantas ornamentais: alternativas sustentáveis aos reguladores de crescimento
V Jornadas Ibéricas de Horticultura Ornamental, Faro, 13-15 Outubro, 2011A necessidade de encontrar estratégias sustentáveis eficazes no
controlo da altura da planta é actualmente um grande desafio que se
coloca à horticultura ornamental protegida. Este estudo teve como
objectivo: (1) analisar a informação disponível acerca dos factores que
afectam a altura das plantas; (2) compreender os mecanismos
fisiológicos envolvidos no processo de alongamento do caule; (3)
definir alternativas sustentáveis para produzir plantas compactas,
reduzindo ao mínimo a aplicação de ‘reguladores químicos de
crescimento’. Concluiu-se que manter uma temperatura nocturna
superior à temperatura diurna (DIF negativa ou tratamento DROP) ou
a alteração do espectro luminoso (elevado rácio vermelho/vermelholongínquo)
apresentam um forte potencial como métodos não
químicos no controlo da altura de várias espécies de plantas
ornamentais. O aumento do rácio vermelho/vermelho-longínquo,
poderá ser efectuado de diferentes modos incluindo a utilização de
filmes fotosselectivos e/ou recorrendo a um conjunto de medidas
facilmente aplicáveis tais como: (i) evitar densidades de plantação
muito elevadas; (ii) utilização de luz suplementar com elevado rácio
vermelho/vermelho-longínquo (ex. lâmpadas de assimilação em
substituição de lâmpadas incandescentes); (iii) evitar a exposição das
plantas à radiação do crepúsculo (devido à diminuição natural do rácio
vermelho/vermelho-longínquo). O stress mecânico é também uma
medida eficaz para a manutenção de plantas compactas em
determinadas espécies. Paralelamente, o recurso ao Melhoramento de
plantas no sentido de seleccionar cultivares ananicantes poderá ser bastante promissor. Porém, na maioria dos casos, não será uma
medida única que permitirá a obtenção de plantas compactas, mas a
combinação de várias estratégiasinfo:eu-repo/semantics/publishedVersio
Seasonal variation of zooplankton and environmental conditions along a transect in the Gulf of Cádiz
This study presents seasonal variation in the zooplankton composition of the Gulf of Cádiz was studied between 2001 and 2012. Samples were collected three times per year, in the spring, summer and autumn at three stations situated along a transect perpendicular to the coast. The total zooplankton abundance during the summer was higher than in the spring and autumn. Zooplankton community is characterized by a seasonal cycle mirroring similar cycles in the physical environment. Differences in community composition were also found along the transect, particularly between the coastal station, under the influence of the Guadalquivir River, and the outer station, characterized by oceanic conditions. This study is the first description of the seasonal and spatial variation of this marine component of the Gulf of Cádi
Evolutionary design of decision-tree algorithms tailored to microarray gene expression data sets
Decision-tree induction algorithms are widely used in machine learning applications in which the goal is to extract knowledge from data and present it in a graphically intuitive way. The most successful strategy for inducing decision trees is the greedy top-down recursive approach, which has been continuously improved by researchers over the past 40 years. In this paper, we propose a paradigm shift in the research of decision trees: instead of proposing a new manually designed method for inducing decision trees, we propose automatically designing decision-tree induction algorithms tailored to a specific type of classification data set (or application domain). Following recent breakthroughs in the automatic design of machine learning algorithms, we propose a hyper-heuristic evolutionary algorithm called hyper-heuristic evolutionary algorithm for designing decision-tree algorithms (HEAD-DT) that evolves design components of top-down decision-tree induction algorithms. By the end of the evolution, we expect HEAD-DT to generate a new and possibly better decision-tree algorithm for a given application domain. We perform extensive experiments in 35 real-world microarray gene expression data sets to assess the performance of HEAD-DT, and compare it with very well known decision-tree algorithms such as C4.5, CART, and REPTree. Results show that HEAD-DT is capable of generating algorithms that significantly outperform the baseline manually designed decision-tree algorithms regarding predictive accuracy and F-measure
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