18,410 research outputs found

    Factors affecting rind pitting in the mandarin hybrids "fortune" and "nova". The influence of exogenous growth regulators

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    The commercialization of the mandarin hybrids "Fortune" and "Nova" is hindered by the development of cold-induced pitting in the fruit rind which may develop either in the orchard or during storage and transport. In the late cropping cultivar "Fortune", the pitting develops on tree during the winter months and affects mainly the exposed fruit from the north-west quadrant of the tree. The induction of symptoms under uniform conditions in the cold-room reveals differences in the susceptibility to chilling injury among the fruits and the fruit sides. The green fruit is not susceptible. Susceptibility develops as pigmentation progresses, and it is higher for the exposed than for the non-exposed (covered by the foliage) fruits. The application of GA3 at colour-break delays pigmentation and retards the development of susceptibility. The waxing of the fruit offers some protection to cold in the cold-room. However, the incidence of pitting is not related to the wax content of the fruit rind and the application of a wax coverage on tree had only a marginal protective effect. No pitting is usually found on tree in the fruit of the early ripening "Nova" cultivar, which is usually harvested before the winter chilling. The pitting develops during cold storage (8-10 C), and is reduced by GA3 application at colour break, an effect related to the delay in rind pigmentation.info:eu-repo/semantics/publishedVersio

    Molecular effect of an OPTN common variant associated to Paget's disease of bone

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    Paget's disease of bone (PDB) is a chronic bone disorder and although genetic factors appear to play an important role in its pathogenesis, to date PDB causing mutations were identified only in the Sequestosome 1 (SQSTM1) gene at the PDB3 locus. PDB6 locus, also previously linked to PDB, contains several candidate genes for metabolic bone diseases. We focused our analysis in the most significantly associated variant with PDB, within the Optineurin (OPTN) gene, i.e. the common variant rs1561570. Although it was previously shown to be strongly associated with PDB in several populations, its contribution to PDB pathogenesis remains unclear. In this study we have shown that rs1561570 may contribute to PDB since its Tallele results in the loss of a methylation site in patients' DNA, leading to higher levels of OPTN gene expression and a corresponding increase in protein levels in patients' osteoclasts. This increase in OPTN expression leads to higher levels of NF-KB translocation into the nucleus and increasing expression of its target genes, which may contribute to the overactivity of osteoclasts observed in PDB. We also reported a tendency for a more severe clinical phenotype in the presence of a haplotype containing the rs1561570 T allele, which appear to be re-enforced with the presence of the SQSTM1/P392L mutation. In conclusion, our work provides novel insight towards understanding the functional effects of this variant, located in OPTN intron 7, and its implication in the contribution to PDB pathogenesis.national funds from Foundation for Science and Technology (FCT) [UID/Multi/04326/2013]; Canadian Institutes for Health Research, Canada [MOP130457]; CHU de Quebec Foundation; Canadian Foundation for Innovation; Fonds de recherche du Quebec-sante; Laval University; CHU de Quebec-Universite Laval Research Centre; FCT [SFRH/BD/77227/2011, SFRH/BPD/111898/2015]; Fonds de recherche Quebec-Sante (FRQ-S), Quebec, Canad

    Evaluation of quality parameters of apple juices using near-infrared spectroscopy and chemometrics

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    Near-infrared (NIR) spectra were recorded for commercial apple juices. Analysis of these spectra using partial least squares (PLS) regression revealed quantitative relations between the spectra and quality- and taste-related properties of juices: soluble solids content (SSC), titratable acidity (TA), and the ratio of soluble solids content to titratable acidity (SSC/TA). Various spectral preprocessing methods were used for model optimization. The optimal spectral variables were chosen using the jack-knife-based method and different variants of the interval PLS (iPLS) method. The models were cross-validated and evaluated based on the determination coefficients (R-2), root-mean-square error of cross-validation (RMSECV), and relative error (RE). The best model for the prediction of SSC (R-2 = 0.881, RMSECV = 0.277 degrees Brix, and RE = 2.37%) was obtained for the first-derivative preprocessed spectra and jack-knife variable selection. The optimal model for TA (R-2 = 0.761, RMSECV = 0.239 g/L, and RE = 4.55%) was obtained for smoothed spectra in the range of 6224-5350 cm(-1). The best model for the SSC/TA (R-2 = 0.843, RMSECV = 0.113, and RE = 5.04%) was obtained for the spectra without preprocessing in the range of 6224-5350 cm(-1). The present results show the potential of the NIR spectroscopy for screening the important quality parameters of apple juices.National Science Centre, Poland [2016/23/B/NZ9/03591

    Adequação dos exames de radiologia solicitados por um departamento de emergência: um estudo retrospetivo

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    Imaging tests are essential for diagnosis in the emergency context and convey clinical information that is essential to assess the appropriateness of the tests and improve their interpretation. Therefore, we aimed to analyze the imaging tests requested by the Emergency Department in a district hospital.info:eu-repo/semantics/publishedVersio

    Metallothioneins in the clam Ruditapes decussatus: an overview

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    The clam Ruditapes decussatus is a suspension-feeding bivalve mollusc widely distributed in European waters and in the Mediterranean. Due to is economic importance it is heavily harvested in many countries, and particularly in Portugal. Its ability to accumulate high metal concentrations along with its economic importance was the main reason for its selection as a bioindicator. Metallothionein (MT) concentrations in the clams R. decussatus followed by gel filtration chromatography, differential pulse polarography and SDS-PAGE, after Cd exposure, revealed that MT is induced in different tissues (whole soft tissues, gills, digestive gland and remaining tissues) but the level of MT induction is tissue dependent. MT from the gills and the digestive gland give a more sensitive response to assess the effects of metal exposure directly from the water or from the food than in the whole soft tissues. MT levels were also measured in the gills, digestive gland and remaining tissues of R. decussatus collected in the Ria Formosa lagoon (Portugal) from areas of different metal load and during the period of sexual differentiation of the clam. Data revealed that there were significant differences of MT concentrations among sites and season but not among sex. Purification of MT from the digestive gland of R. decussatus revealed four MT isoforms. The molecular weight of one of these isoforms, determined by SDS-PAGE, was of the same order of magnitude as that of MT from other bivalve species. Similarly the amino acid sequence of the beta domain of the MT of the digestive gland of the clam also shows some degree of similarity with the similar MT sequence from mussels and oysters. It is, therefore suggested that there is some degree of similarity in the MT structure among these species.info:eu-repo/semantics/publishedVersio

    Higher education institutions and international students’ hindrances: a case of students from the African Portuguese-speaking countries at two European Portuguese universities

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    We present a study to comprehend if the support given by higher education institution (HEI) to international students coming from the PortugueseSpeaking African Countries meets their academic and social hindrances. Our starting point was a set of semi-structured interviews focused on the perspectives of these students, their Professors and Course Directors as well as on the perspectives of HEI’ staff. Despite findings indicate a positive institutional support, it seems there is still much to do in order to do it properly with these students. These different perspectives will allow us to reflect on the impact that those actions/resources have on the path of students from Portuguese-Speaking African Countries and to systematize suggestions to enhance their experiences in HE.info:eu-repo/semantics/publishedVersio

    Establishing microbial baselines to identify indicators of coral reef health

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    Microorganisms make a significant contribution to reef ecosystem health and resilience via their critical role in mediating nutrient transformations, their interactions with macro-organisms and their provision of chemical cues that underpin the recruitment of diverse reef taxa. However, environmental changes often cause compositional and functional shifts in microbial communities that can have flow-on consequences for microbial-mediated processes. These microbial alterations may impact the health of specific host organisms and can have repercussions for the functioning of entire coral ecosystems. Assessing changes in reef microbial communities should therefore provide an early indicator of ecosystem impacts and would underpin the development of diagnostic tools that could help forecast shifts in coral reef health under different environmental states. Monitoring, management and active restoration efforts have recently intensified and diversified in response to global declines in coral reef health. Here we propose that regular monitoring of coral reef microorganisms could provide a rapid and sensitive platform for identifying declining ecosystem health that can complement existing management frameworks. By summarising the most common threats to coral reefs, with a particular focus on the Great Barrier Reef, and elaborating on the role of microbes in coral reef health and ecosystem stability, we highlight the diagnostic applicability of microbes in reef management programs. Fundamental to this objective is the establishment of microbial baselines for Australia's coral reefs.AIMS@JCU PhD Scholarship; GBRMPA Science Management Research Award; Advance Queensland PhD Scholarship; Portuguese Science and Technology Foundation (FCT) [SFRH/BPD/110285/2015

    Cherenkov radiation with massive, CPT-violating photons

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    The source of CPT violation in the photon sector of the Standard Model Extension arises from a Chern-Simons-like contribution that involves a coupling to a fixed background vector field k(AF)(mu). These Lorentz- and CPT-violating photons have well-known theoretical issues that arise from missing states at low momenta when k(AF)(mu) is timelike. In order to make the theory consistent, a tiny mass for the photon can be introduced, well below current experimental bounds. The implementation of canonical quantization can then be implemented as in the CPT-preserving case by using the Stuckelberg mechanism. We explicitly construct a covariant basis of properly normalized polarization vectors at fixed three-momentum satisfying the momentum space field equations, in terms of which the vector field can be expanded. As an application of the theory, we calculate the Cherenkov radiation rate for the case of purely timelike k(AF)(mu) and find a radiation rate at high energies that has a contribution that does not depend on the mass used to regulate the photons

    Holonomy and parallel transport for Abelian gerbes

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    In this paper we establish a one-to-one correspondence between S1S^1-gerbes with connections, on the one hand, and their holonomies, for simply connected manifolds, or their parallel transports, in the general case, on the other hand. This result is a higher-order analogue of the familiar equivalence between bundles with connections and their holonomies for connected manifolds. The holonomy of a gerbe with group S1S^1 on a simply connected manifold MM is a group morphism from the thin second homotopy group to S1S^1, satisfying a smoothness condition, where a homotopy between maps from [0,1]2[0,1]^2 to MM is thin when its derivative is of rank ≤2\leq 2. For the non-simply connected case, holonomy is replaced by a parallel transport functor between two monoidal Lie groupoids. The reconstruction of the gerbe and connection from its holonomy is carried out in detail for the simply connected case. Our approach to abelian gerbes with connections holds out prospects for generalizing to the non-abelian case via the theory of double Lie groupoids.Comment: Final version. Improved readibility (hopefully). LaTeX, 60 pages, 14 figures. To appear in Advances in Mathematic

    Potential natural vegetation and pre-anthropic pollen records on the Azores Islands in a Macaronesian context

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    This paper discusses the concept of potential natural vegetation (PNV) in the light of the pollen records available to date for the Macaronesian biogeographical region, with emphasis on the Azores Islands. The classical debate on the convenience or not of the PNV concept has been recently revived in the Canary Islands, where pollen records of pre-anthropic vegetation seemed to strongly disagree with the existing PNV reconstructions. Contrastingly, more recent PNV model outputs from the Azores Islands show outstanding parallelisms with pre-anthropic pollen records, at least in qualitative terms. We suggest the development of more detailed quantitative studies to compare these methodologies as an opportunity for improving the performance of both. PNV modelling may benefit by incorporating empirical data on past vegetation useful for calibration and validation purposes, whereas palynology may improve past reconstructions by minimizing interpretative biases linked to differential pollen production, dispersal and preservation.Spanish Ministry of Economy and Competititvity, project PaleoNAO [CGL2010-15767]Spanish Ministry of Economy and Competititvity, project RapidNAO [CGL2013-40608-R]Spanish Ministry of Economy and Competititvity, project PaleoMODES [CGL2016-75281-C2-1-R]info:eu-repo/semantics/publishedVersio
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