1,114 research outputs found

    Novel mutation in the mitochondrial transfer RNACys gene in a child

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    Mitochondrial DNA (mtDNA) disorders are an important group of genetic diseases presenting with a multifacet array of clinical manifestations. Highly energy-dependent tissues such as central nervous system and skeletal and cardiac muscles are commonly involved either as multisystem or as isolated organ disease. Characteristic symptoms include epilepsy, myopathy, deafness and ophthalmoplegia, all associated with point mutations in the mtDNA. Pathogenic mtDNA mutations can be heteroplasmic or homoplasmic. Heteroplasmic mutations are typically associated with mutations in mt-tRNA genes. Mutations in mt-tRNAs genes are responsible for the majority of the presentations of a mitochondrial disease being associated with marked clinical heterogeneity. Although tRNA-encoding genes make up only 9% of the entire mitochondrial genome, over 40% of all point mutations reported in the mtDNA are located in tRNA genes. Here, we present a child with vomiting episodes and migraine in whom we found a novel variant in the mitochondrial tRNACys gene

    The Role of Coral Reefs in Coastal Protection: Analysis of Beach Morphology

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    This paper evaluates the effect of a fringing reef on the morphodynamic behaviour of adjacent beaches in terms of profile stability and cross-shore sediment exchange. Variations in subaerial beach morphology along 39 cross-shore profiles at Pontal do Cupe beach (Northeastern Brazil) were analysed, using modelled wave data and monthly beach topography acquired from November 2014 to September 2016. Pontal do Cupe has a reef to the south but is exposed to waves in the north, making this an ideal location to assess the sheltering effect of the reef. Beach volume and beach width data were used to compare the reef-fronted profiles with those of the exposed adjacent beach. Seven groups of profiles were identified by applying Principal Component Analys is to the topography dataset. A simple numerical model was used to quantify the role of the reef in dissipating wave energy, showing a reduction of approximately 50% in incoming wave energy to the shore. The reef-fronted beach is significantly more stable than the exposed beach. Total beach volume is similar for both the exposed and the reef-fronted beach. The results of this survey can be used as a proxy for the ecosystem service of coastal protection provided by reefs

    Micropropagation of a recalcitrant pine (Pinus pinea L.): An overview of the effects of ectomycorrhizal inoculation

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    Stone pine (Pinus pinea L.) is an economically important forest species in some regions of Iberian Peninsula. Portugal and Spain have nearly 500,000 ha of stone pine stands, representing 85% of worldwide distribution. The main use of this species is for the production of seeds (pinion) for food industry. In addition to its enormous profitability as a producer of seeds, it has beneficial impact on soil protection, dunes fixation and is a pioneer species particularly for cork and holm oaks degraded ecosystems. Stone pine plantations are today a major source of income for forestry holdings. Investments have targeted breeding, reforestation, forest management and harvesting. The maternal inheritance of desirable characteristics such as cone weight, number of seeds per cone and seed length is considerably high in this species thus encouraging the selection of seeds from “plus” trees. The selected trees have been propagated by grafting and micropropagation. However, grafting generates high variability due to scion-rootstock interaction that varies production levels. The production of clonal plants from selected seeds by micropropagation techniques has advanced very slowly due to the recalcitrance of this species in tissue culture and particularly to adventitious rooting of microshoots. Due to the tremendous importance of developing a reproducible tissue culture method for clonal propagation, a study has been carried out for over a decade to enhance rooting and acclimation. During this period of time, continuous increments in the multiplication rate and rooting frequency were achieved by introducing variations in culture media composition and conditions. Auxins, carbohydrates, light quality and duration, temperature at different concentrations and levels as well as compounds such as coumarin; salicylic acid, polyamines, etc. were tested for induction and expression phases of adventitious rooting. Despite these efforts, microshoots regenerated through organogenesis from mature embryo cotyledons failed to root or to have sustained root growth. At this point, an in vitro co-culture technique of stone pine microshoots with ectomycorrhizal-fungi was introduced to overcome the adventitious root growth cessation in vitro and improve root development during acclimation phase. An overview of the results showing the positive effect of fungal inoculation in promoting root growth in vitro and on plantlet survival during acclimation will be presented. Preliminary results of biochemical signals between Pinus pinea/Pisolithus arhizus during early steps of in vitro culture detected by liquid chromatography-mass spectrometry that might be responsible for the positive effect on root growth will be also presented

    Development of ternary diagrams for estimating water retention properties using geostatistical approaches

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    Most pedotransfer functions (PTFs) have adopted soil texture information as the main predictor to estimate soil hydraulic properties, whether inputs are defined in terms of the relative proportion of different grain size particles or texture-based classifications. The objective of this studywas to develop ternary diagrams for estimating soil water retention (θ) at−33 and−1500 kPa matric potentials, corresponding to the field capacity and wilting point, respectively, from particle size distribution using two geostatistical approaches. The texture triangle was divided into a 1% grid of soil texture composition resulting in 4332 different soil textures. Measured soil water retention values determined in 742 soil horizons/layers located in Portugal were then used to develop and validate the hydraulic ternary diagrams. The development subset included two-thirds of the data, and the validation subset the remaining samples. The measured soil water content values were displayed in the ternary diagram according to the coordinates given by the particles size distribution determined in the same soil samples. The volumetric water content values were then predicted for the entire ternary diagram using two different geostatistical interpolation algorithms (ordinary kriging and the empirical best linear unbiased predictor). Uncertainty analysis resulted in a root mean square error below 0.040 and 0.034 cm3 cm−3 when comparing the interpolated water contents at −33 and −1500 kPa matric potential values, respectively, with the measured ones included in the validation dataset. The estimation variance calculated with both methods was also considered to access the uncertainty of the predictions. The available water content of Portuguese soils was then derived from θ−33 kPa and θ−1500 kPa ternary diagrams developed with both approaches. The hydraulic ternary diagrams may thus serve as simplified tools for estimating water retention properties from particle size distribution and eventually serve as an alternative to the traditional statistical regression and data mining techniques used to derive PTFsinfo:eu-repo/semantics/publishedVersio

    Modelling economic impacts of deficit irrigated maize in Brazil with consideration of different rainfall regimes

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    Deficit irrigation is often required to cope with droughts and limited water availability. However, to select an appropriate irrigation management, it is necessary to assess when economic impacts of deficit irrigation are acceptable. Thus, the main goal of this study was to evaluate economic water productivity for maize submitted to various levels of water deficits and different irrigation systems. The study was based on two different experiments conducted in Southern Brazil, one using sprinkler irrigation to supplement rainfall and the other using drip irrigation with precipitation excluded by a rainfall shelter to simulate cultivation under dry conditions. Water productivity indicators were calculated referring to: a) actual field collected data, including yields, commodity prices and production costs; and b) a sensitivity analysis to commodity prices and production costs. Alternative centrepivot irrigation scenarios were also developed to assess their feasibility in terms of water use and productivity when irrigation is used to supplement rainfall or when rainfall is scarce. Results show that the feasibility of deficit irrigation is highly influenced by commodity prices and by the irrigation (and water) costs when the irrigation costs are a large part of the production costs. Results also show that deficit irrigation applied when rainfall is abundant is easier to implement than deficit irrigation where rainfall is very scarce, when only a mild stress is economically viable. For well-designed and managed centrepivot systems, results confirm that adopting deficit irrigation when rainfall is scarce is less attractive than under conditions of irrigation to supplement rainfall. It could be concluded that farmers are unlikely to choose a deficit irrigation strategy unless they are facing reduced water availability for irrigatio

    Melanoma Ganglionic Metastasis 30 Years After Treatment Of The Primary Tumor--a Case Report.

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    The recurrence of melanoma in patients is well-documented, and is dependent on a number of factors. We report a case in which a patient had a case of ganglionar metastasis in the neck after a 30-year disease-free interval following primary treatment.11421131113

    Modelling soil water dynamics of full and deficit drip irrigated maize cultivated under a rain shelter

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    Research PaperThe model HYDRUS-1D was used to simulate soil water dynamics of full and deficit irrigated maize grown under a rainout shelter during two crop seasons. Four irrigation treatments were established based on the amount of water applied to fulfil crop water requirements. Treatment D1 was irrigated to fully satisfy crop water requirements, while treatments D2 (mild deficit), D3 (moderate deficit), and D4 (severe deficit) were for increased controlled water stress conditions. The computation and partitioning of evapotranspiration data into soil evaporation and crop transpiration was carried out with the SIMDualKc model, and then used with HYDRUS-1D. The soil hydraulic properties were determined from numerical inversion of field water content data. The compensated root water uptake mechanism was used to describe water removal by plants. TheHYDRUS-1D model successfully simulated the temporal variability of soil water dynamics in treatments irrigated with full and deficit irrigation, producing RMSE values that varied between 0.014 and 0.025 cm3 cm 3 when comparing model simulations with field measurements. Actual transpiration varied between 224 and 483 mm. Potential transpiration reductions varied from 0.4 to 48.8% due to water stress, but plants were able to compensate for the water deficits in the surface layers by removing more water from the deeper, less stressed layers. HYDRUS-1D water balance estimates were also comparable with the corresponding ones determined with the SIMDualKc water balance model. Both modelling approaches should contribute to improve the webbased IRRIGA system, used to support farm irrigation scheduling in Brazilinfo:eu-repo/semantics/publishedVersio

    Pisolithus arhizus (Scop.) Rauschert improves growth of adventitious roots and acclimatization of in vitro regenerated plantlets of Pinus pinea L.

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    Stone pine (Pinus pinea L.) is an economically important forest tree in the Mediterranean region and has been the target of breeding and selection through micropropagation mainly for its ecological and ornamental aspects. A crucial step in micropropagation is adventitious rooting of microshoots, which often is highly inefficient in most conifer species including stone pine. Hence, we conducted in vitro co-culture of Pinus pinea microshoots with the ectomycorrhizal fungus Pisolithus arhizus (isolated from natural stands) in order to promote adventitious root growth and plant survival during acclimatization. Significant differences were found in the number of branches, in the number of roots plus branches, in total length of roots, in total length of roots plus branches, in average root length and in the length of the longest root in inoculated plants during in vitro rooting compared with non-inoculated plants. The roots of inoculated plants also grew better in vermiculite and during acclimatization in a mixed substrate compared with roots of control plants resulting in the development of vigorous root system. Overall, mycorrhizal inoculation increased the survival rate of the regenerated pine

    Soil hydraulic properties in different soil texture classes

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    Soil texture influences significantly soil hydraulic properties, which due to soil he-terogeneity normally present large spatial variability. The variability of soil reten-tion θ(h), and hydraulic conductivity K(h) curves, in 11 of the 12 texture classes of the diagram of Gomes e Silva (1962) was studied. For each textural class, average, maximum, minimum, and the standard deviation values for the Mualem van Ge-nuchten parameters are presented based on 558 θ(h) and 245 K(h) curves deter-mined in undisturbed soil samples which are included in the PROPSOLO database of Estação Agronómica Nacional. An av-erage function describing θ(h) and K(h) in each textural class is also presente
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