1,220 research outputs found

    Ecophysiological potential of the Dão terroir for the production of Touriga Nacional red grapes

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    Proceedings - IX International Terroir Congress, 2012Aiming to evaluate the potential of the portuguese Dão winegrowing region for the production of Touriga Nacional (TN) red grapes, climatic, ecophysiological and viticultural data from two different climatic years (2004, wet year and 2005, dry year) are presented and discussed. The data was collected in the control non-irrigated plants of an irrigation experiment installed at the Dão Research Station, Nelas, Portugal. The vineyard is established in a typical granitic soil and trained on a vertical shoot positioning. According to the Géoviticulture Multicriteria Climatic Classification System, the Dão region is classified as temperate/temperate warm for the heliothermal index, with cool nights (night cold index) and moderately dry (dryness index). In 2004 the predawn leaf water potential presented always values higher than -0.2 MPa from flowering to harvest but in 2005 moderate to severe water stress was observed during the ripening period (-0.4 MPa at veraison to -0.6 MPa at harvest). Leaf stomatal conductance and photosynthetic rate displayed a decreasing pattern from flowering to harvest in both years but attained much lower values in the 2005 ripening period as compared to that of 2004. The yield was similar in both years but 2005 showed lower sugar content, similar titratable acidity and a higher anthocyanin berry skin content. Our data shows that the Dão terroir presents a high inter-annual climate variability which has important repercussions on TN responses being the most unfavorable climatic years those were the high temperatures are coincident with water stress during the first half of the ripening period. In those years irrigation should be applied in order to obtain better quality grapes

    Effect of escitalopram on the processing of emotional faces

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    Serotonin has been implicated in the neurobiology of depressive and anxiety disorders, but little is known about its role in the modulation of basic emotional processing. The aim of this study was to determine the effect of the selective serotonin reuptake inhibitor, escitalopram, on the perception of facial emotional expressions. Twelve healthy male volunteers completed two experimental sessions each, in a randomized, balanced order, double-blind design. A single oral dose of escitalopram (10 mg) or placebo was administered 3 h before the task. Participants were presented to a task composed of six basic emotions (anger, disgust, fear, happiness, sadness, and surprise) that were morphed between neutral and each standard emotion in 10% steps. Escitalopram facilitated the recognition of sadness and inhibited the recognition of happiness in male, but not female faces. No drug effect on subjective measures was detected. These results confirm that serotonin modulates the recognition of emotional faces, and suggest that the gender of the face can have a role in this modulation. Further studies including female volunteers are needed

    Effects of irrigation on the vigour, yield and berry composition of the red variety Touriga Nacional at the Dão winegrowing region, Portugal

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    Proceedings - 17 th International Symposium GIESCO, Asti, Italy, 2011In a field trial installed at the Centro de Estudos Vitivinícolas do Dão, Nelas, Portugal, the effect of three irrigation treatments on the agronomic behaviour of cv Touriga Nacional (Vitis vinifera L.) were studied during three growing seasons (2006-2008). Three irrigation treatments (DI30 - irrigation with 30% of ETc; DI50 - irrigation with 50% ETc, FI - full irrigation – 100% Etc) were compared to a control non-irrigated treatment (NI). Compared to NI, the deficit irrigation treatments (DI30 & DI50) showed no significant differences on the yield and its components. The full irrigation treatment induced a significantly higher yield due to a higher bunch weight, as compared with the others treatments. Compared to the control, the deficit irrigation treatments presented similar berry composition during all the three seasons. The FI treatment presented, in all seasons, a significantly higher total acidity and a significantly lower Brix and total anthocyanins concentration as compared to the other treatments. The pruning weight and shoot weight increased with the amount of irrigation water applied, but significant differences were found only between the FI and the NI treatments, the last presenting the lowest values. Despite the fact that in the non-irrigated vineyards of the Dão winegrowing region it is very common to observe vine water stress symptoms, mainly during the ripening period, during the three studied seasons (2006-2008), the deficit irrigation treatments showed no advantages relatively to the control non-irrigated. Despite the higher yield produced in the full irrigation, this treatment had the disadvantages of the excessive vine vigour and lower must quality produced

    Influence de l'effeuillage sur l'efficience thermique de l'accumulation des anthocyanes dans la baie

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    The aim of this work was to analyse the effects of leaf removal on Touriga Nacional berry temperature and consequent thermal efficiency for anthocyanins biosynthesis. The field experiment was located at Dão Wine Research Station, Nelas, Portugal in an adult vineyard planted with North-South oriented rows, with the red grape variety Touriga Nacional grafted on 110R rootstock. The vines were trained on a vertical shoot positioning, spur-pruned on a bilateral Royat cordon system and deficit irrigated (50% ETc). The experimental design was a randomized complete block design with four replications of twelve vines per elemental plot, and the following two treatments: basal leaf removal (LR) and a control non-defoliated (ND). Berry temperature (Tb) was measured continuously during the second half (3rd to 19th September) of the 2009 ripening period using two-junction, fine-wires copper-constantan thermocouples manually inserted into the berries and connected to a data logger. A sample of clusters located in different canopy positions (exposed and internal; facing East and West) of 4 vines per treatment were used. To quantify the effect of Tb on anthocyanins biosynthesis, the berry hourly mean temperatures were converted into normal heat hours (NHH) and accumulated per day (NHHd) and per monitoring period (NHHc). For quantification of thermal requirements for anthocyanins synthesis and accumulation, a minimum of 10°C, a maximum of 35°C, and an optimum of 26°C were used. Meteorological variables were measured at an automatic weather station installed within the experimental plot. For all days of the monitoring period, daily average berry temperature (dTb) of all monitored berries was lower in ND treatment than in LR, being the maximum differences between treatments registered on 11th September. The highest dTb differences between treatments were registered on the clusters located at the west side of the canopy on 7th September while dTb of the clusters located in the centre of the canopy was less affected by leaf removal. The control non-defoliated treatment (ND) presented a significantly higher NHHc than that of LR being the higher differences presented by the clusters located in the west side. The lowest differences in NHHc were obtained in the clusters located in the centre of the canopy. Our results show that the thermal efficiency for berry anthocyanins accumulation was significantly affected by leaf removal and that this effect was dependent of the meteorological conditions, time of the day and berry/cluster location into the vine canopy

    Daily evolution of the components of the balance of radiation of vines in a vineyard in the Dão region

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    Proceedings - 17 th International Symposium GIESCO, Asti, Italy, 2011In order to validate a model of vine transpiration based on radiative surface temperature a field trial was conducted in a vineyard in the Dão region, centre of Portugal, with the cultivar “Touriga Nacional”. The model is based on the partition of net radiation between the components of the canopy (vines, soil, and grass cover), considering that the vines and the undercover (soil plus grass cover) act separately and in parallel. Thus, the latent heat flux from the vines to the atmosphere (lTc) is determined from vine net radiation (Rnc) and sensible heat flux (Hc). The partition of net radiation (Rn) between the undercover (Rns) and the vines (Rnc) is made considering the exponential form for radiation extinction, with the coefficient of extinction being corrected with a factor dependent on the zenital solar angle (j) while leaf area index (LAI) is corrected with a clumping factor, Ω(φ). Sensible heat flux from the vines (Hc) is calculated from radiative temperature (Tc) considering that the fluxes from the different origins are independent and that there are two resistances in series between the canopy and the atmosphere: the leaf boundary layer resistance (raHc) and the aerodynamic resistance of the crop (raH). Besides the estimation of the daily values of transpiration, the model allows to study the evolution of the different components of the radiation balance throughout the day. The daily evolution of the evaporation fraction from the vines (FEc) can be approximated by a concave curve. Values of FEc > 1 show that, under certain circumstances and periods of the day, energy used for transpiration (lTc) is greater than crop net radiation, which indicates that there are exchanges of energy between the several components of the surface, namely when evaporative demand from the atmosphere is high and there are no soil water restrictions. The model also shows that, regardless of the soil water status, transpiration is a big part of Rn when these values are low (in the beginning of the morning and late afternoon)

    Influence of ink rheology and post processing in the structural performance of silicon nitride-based ceramics fabricated by robocasting

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    The fabrication of complex shaped Si3N4 parts by conventional methods is challenging due to its high hardness and mechanical strength. Additive manufacturing (AM) appeared as a competitive way to attain three-dimensional complexity at lower costs. However, most of AM technologies still present limitations in producing high dense ceramics, mainly due to several difficulties in developing proper feedstock. This work presents the fabrication of dense silicon nitride-based ceramics by using an extrusion based additive manufacturing technique (direct ink writing, also known as robocasting) and cold isostatic pressing (CIP) as a post processing step. Silicon-nitride aqueous based inks containing different amounts of solids loading (36, 38 and 39 vol%) and proper rheological characteristics for the printing process were studied. The use of CIP (200 MPa) is suggested to reduce or even eliminate defects and porosity and consequently, to improve mechanical performance of the final parts. Relative density, microhardness and flexural strength increased as solids loading in the inks increased and were further improved when CIP pressing was used. Parts produced by robocasting with an ink containing 39 vol% and cold isostatic pressed at 200 MPa exhibited an average relative density around 99%, 1475 HV2 microhardness value and 650 MPa flexural strength, values similar to those of silicon nitride ceramics fabricated by conventional processing.publishe

    Insights on the evolution of bacterial susceptibility exposed to multiple antibiotics: a triennial epidemiological study

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    Introduction: The emergence and propagation of multi-resistant bacteria in the hospital environment have become serious epidemiological and therapeutic problems. It is essential to update data regarding the susceptibility to the most commonly used antibiotics in each hospital, allowing obtaining specific resistance patterns to define the antibiotic therapy. Objectives: This study aims to establish a profile of susceptibility vs. resistance for different microorganisms isolated during 3 years (2009-2011) using 3300 clinical isolates of different biological samples obtained from different hospital units belonging to Centro Hospitalar de Trás-os-Montes e Alto Douro (CHTMAD). Methods: Identification and susceptibility tests were done using microdilution plate method and results were submitted to principal component analysis (PCA). Results: Methicillin resistant Staphylococcus aureus (MRSA), Enterococcus faecium and coagulase negative Staphylococcus (CNS) seem to be the most concerning Gram positive microorganisms. For Gram negative species, despite the high resistance presented by Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBL) to b-lactamic antibiotics, imipenem is still a good therapeutic option, as well as fosfomycin (for urinary infection). Stenotrophomonas maltophilia, Pseudomonas aeruginosa MR and Acinetobacter baumannii, are progressively acquiring higher resistance to these antibiotics, mainly to imipenem, cotrimoxazol and even aminoglycosides (tobramycin and gentamycin). Conclusions: Overall, the developed resistance seems to be directly associated with antibiotics use and, therefore, studies centered in multi-resistance to antibiotics are crucial to establish dynamic protocols adequate to specific resistance vs. susceptibility profiles

    Teores de vitamina E em diferentes variedades de castanea sativa

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    Vitamina E é a designação comum de uma familia de compostos relacionados, nomeadamente as tocoferóis e as tocotrienóis, caracterizada por conter uma cadeia lateral isoprénica Iigada ao cromanol [1]. A caracterização qualitativa e quantitativa dos diferentes vitâmeros, apesar de estruturalmente similares, é fundamentada pelas diferenças nas respectivas actividades biológicas

    Phenolic profile and bioactivity of cardoon (Cynara cardunculus L.) inflorescence parts: Selecting the best genotype for food applications

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    This study was designed to characterize the phenolic profile and bioactivity of hydroalcoholic extracts from different cardoon (Cynara cardunculus L.) genotypes. The analytical work focussed on the inflorescence stigmas, owing to their application in cheese production. Nevertheless, other parts were concomitantly analysed aiming to define their possible use in related applications. Phenolic profiles obtained by LC-DAD-ESI/MSn showed significant differences among different cardoon genotypes, but apigenin and caffeoylquinic acid derivatives were generally the major molecules in all samples. Genotype influence has also been observed in relation to the antioxidant and antibacterial activities. Besides their strong antioxidant activity, the cardoon inflorescences showed satisfactory antibacterial activity, namely against Gram-positive strains, with particularly low MIC in Listeria monocytogenes. Overall, it was possible to identify the cardoon genotype (within the selected ones) providing the best standardized ingredient (stigma) with considerable added-value to be included in the process of cheese making.info:eu-repo/semantics/publishedVersio

    Propensity for biofilm formation by clinical isolates from urinary tract infections: developing a multifactorial predictive model to improve the antibiotherapy

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    A group of biofilm-producing bacteria isolated from patients with urinary tract infections was evaluated, identifying the main factors contributing to biofilm formation. Among the 156 isolates, 58 (37.2%) were biofilm producers. The bacterial species (P<0.001), together with patient's gender (P = 0.022), were the factors with the highest influence for biofilm production. There was also a strong correlation of catheterization with biofilm formation, despite being less significant (P = 0.070) than species or gender. In fact, some of the bacteria isolated were biofilm producers in all cases. With regard to resistance profile among bacterial isolates, β-lactam antibiotics presented the highest number of cases/percentages--ampicillin (32/55.2%), cephalothin (30/51.7%), amoxicillin/clavulanic acid (22/37.9%)--although the carbapenem group still represented a good therapeutic option (2/3.4%). Quinolones (nucleic acid synthesis inhibitors) also showed high resistance percentages. Furthermore, biofilm production clearly increases bacterial resistance. Almost half of the biofilm-producing bacteria showed resistance against at least three different groups of antibiotics. Bacterial resistance is often associated with catheterization. Accordingly, intrinsic (age and gender) and extrinsic (hospital unit, bacterial isolate and catheterization) factors were used to build a predictive model, by evaluating the contribution of each factor to biofilm production. In this way, it is possible to anticipate biofilm occurrence immediately after bacterial identification, allowing selection of a more effective antibiotic (among the susceptibility options suggested by the antibiogram) against biofilm-producing bacteria. This approach reduces the putative bacterial resistance during treatment, and the consequent need to adjust antibiotherapy.Fundação para a Ciência e a Tecnologia (FCT, Portugal) and COMPETE/QREN/EU for financial support to this work (strategic projects PEst-OE/AGR/UI0690/2011 and PEst-OE/EQB/LA0016/2011). They also thank to CHTMAD – Hospital Center of Trás-os-Montes e Alto Douro and Siemens for all the support. J.C.M. Barreira also thanks to FCT, POPH-QREN and FSE for his grant (SFRH/BPD/72802/2010
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