Convergence of the Crank-Nicolson-Galerkin finite element method for a class of nonlocal parabolic systems with moving boundaries

The aim of this paper is to establish the convergence and error bounds to the fully discrete solution for a class of nonlinear systems of reaction-diffusion nonlocal type with moving boundaries, using a linearized Crank-Nicolson-Galerkin finite element method with polynomial approximations of any degree. A coordinate transformation which fixes the boundaries is used. Some numerical tests to compare our Matlab code with some existing moving finite elements methods are investigated

From customer motivation to corporate performance. The role of strategic factors and distribution channels of financial service firms

This research analyzes the relationship between strategic factors and distribution channels and the performance of financial service firms, based on the theory of distribution channels and the resource-based view. Using structural equation modeling, the study examines a sample of 252 insurance firms operating in the Iberian Peninsula. The empirical analysis provides conclusive evidence that strategic factors have an influence on the firm’s distribution channels and performance. It also confirms that internal and external determinant factors as well as customer motivation have an influence on strategic factors.info:eu-repo/semantics/publishedVersio

Historical gene flow constraints in a northeastern Atlantic fish: phylogeography of the ballan wrasse Labrus bergylta across its distribution range

14 páginas, 3 figuras, 3 tablas.-- Frederico Almada ... et al.-- Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are creditedThe distribution and demographic patterns of marine organisms in the north Atlantic were largely shaped by climatic changes during the Pleistocene, when recurrent glacial maxima forced them to move south or to survive in northern peri-glacial refugia. These patterns were also influenced by biological and ecological factors intrinsic to each species, namely their dispersion ability. The ballan wrasse (Labrus bergylta), the largest labrid fish along Europe's continental margins, is a target for fisheries and aquaculture industry. The phylogeographic pattern, population structure, potential glacial refugia and recolonization routes for this species were assessed across its full distribution range, using mitochondrial and nuclear markers. The existence of a marked population structure can reflect both recolonization from three distinct glacial refugia and current and past oceanographic circulation patterns. Although isolated in present times, shared haplotypes between continental and Azores populations and historical exchange of migrants in both directions point to a common origin of L. bergylta. This situation is likely to be maintained and/or accentuated by current circulation patterns in the north Atlantic, and may lead to incipient speciation in the already distinct Azorean population. Future monitoring of this species is crucial to evaluate how this species is coping with current environmental changesThis study was funded by the Eco-Ethology Research Unit Strategic Plan (PEst-OE/MAR/UI0331/2011)—Fundação para a Ciência e a Tecnologia—FCT (partially FEDER funded), now included in MARE (UID/MAR/04292/2013). F.A. (SFRH/BPD/63170/2009) and S.M.F. (SFRH/BPD/84923/2012) were supported by FCT grants. C.S.L. was supported by MARE-ISPA/BI/004/2015. D.V.-R. was supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (grant no. 625852). Sampling in the Azores was supported by CLIPE (PRAXIS/3/3.2/EMG/1957/95) and in continental Iberia by the European Science Foundation's MarinERA project ‘Marine phylogeographic structuring during climate change: the signature of leading and rear edge of range shifting populations'Peer reviewe

Efficacy and tolerability of airway stents

The function of airway stents is to keep the tubular structures open and stable. Their insertion is essentially indicated for intrinsic obstruction or extrinsic compression of the airway, fistulae or tracheobronchomalacia. The aim of this study was to determine the tolera bility and efficacy of airway stents in situations in which their insertion was vital. A retrospective study of airway stent insertion with rigid bronchoscopy (23 patients) was carried out over a two year period (2006-2007) at the Diagnostic and Therapeutic Techniques Unit. We assessed indication, efficacy, tolerability, complications and exact insertion based on chest CT imaging. In all situations Dumon flexible silicon stents (Tracheobronxane were used, with the need for complementary techniques such as laser therapy and mechanical dilation having been previously evaluated by flexible bronchoscopy. The authors conclude that stent insertion has no complications and good tolerability in the majority of advanced stage oncological situations with indication for palliative management

Sarcoidosis: a less common presentation.

The clinical presentation of sarcoidosis is diverse and in over 90% of patients there is pulmonary involvement. The most common features of the radiographic findings at the time of diagnosis are bilateral hilar lymphadenopathy and pulmonary infiltration. The authors report the case of a young female patient who presented with multiple bilateral nodular shadows on chest radiograph. Surgical biopsy revealed non-necrotizing granulomas with occasional multinucleated giant cells compatible with sarcoidosis. Although this was a case of stage III pulmonary disease, the patient was asymptomatic, lung function tests were normal and there were no signs of extrathoracic involvement. Spontaneous remission occurred without treatment as shown on high resolution CT scan follow-up, one year later

Bronchoalveolar lavage in occupational lung diseases

Occupational lung diseases (OLDs) are related to the exposure and inhalation of organic, inorganic, and synthetic particles, fumes, gases, or infectious agents. From the long list of OLDs this article focuses the discussion on bronchoalveolar lavage (BAL) in parenchymal immunoinflammatory conditions, such as hypersensitivity pneumonitis (HP) and pneumoconiosis. Several antigens may cause HP, including products of plant or animal origin, aerosolized microorganisms, and organic chemicals. BAL is used not only to assess the pathogenesis of these diseases but also to identify the typical pattern of intense lymphocytic alveolitis, usually with a CD4:CD8 ratio below normal and frequently with the presence of mast cells, plasma cells, and foamy macrophages. Pneumoconioses are chronic interstitial lung diseases caused by the inhalation of mineral and metallic inorganic particles/dusts in an occupational setting, showing a decreasing prevalence in recent years. BAL is a useful tool not only to express the complex pathogenic mechanisms of these entities but also in excluding other diagnoses and causes of alveolitis, and to document specific exposures, such as the identification of asbestos bodies (ABs) in asbestosis or the proliferative response of BAL lymphocytes to beryllium in chronic beryllium disease (CBD)

Influence of methylene fluorination and chain length on the hydration shell structure and thermodynamics of linear diols

The interplay between the local hydration shell structure, the length of hydrophobic solutes, and their identity (perfluorinated or not) remains poorly understood. We address this issue by combining Raman–multivariate curve resolution (Raman-MCR) spectroscopy, simulation, and quantum-mechanical calculations to quantify the thermodynamics and the first principle interactions behind the formation of defects in the hydration shell of alkyl–diol and perfluoroalkyl–diol chains. The hydration shell of the fluorinated diols contains substantially more defects than that of the nonfluorinated diols; these defects are water hydroxy groups that do not donate hydrogen bonds and which either point to the solute (radial-dangling OH) or not (nonradial-dangling OH). The number of radial-dangling OH defects per carbon decreases for longer chains and toward the interior of the fluorinated diols, mainly due to less favorable electrostatics and exchange interactions; nonradial-dangling OH defects per carbon increase with chain length. In contrast, the hydration shell of the nonfluorinated diols only contains radial-dangling defects, which become more abundant toward the center of the chain and for larger chains, predominantly because of more favorable dispersion interactions. These results have implications for how the folding of macromolecules, ligand binding to biomacromolecules, and chemical reactions at water–oil interfaces could be modified through the introduction of fluorinated groups or solvents

Influence of the sterol aliphatic side chain on membrane properties: a molecular dynamics study

Following a recent experimental investigation of the effect of the length of the alkyl side chain in a series of cholesterol analogues (Angew. Chem., Int. Ed., 2013, 52, 12848–12851), we report here an atomistic molecular dynamics characterization of the behaviour of methyl-branched side chain sterols (iso series) in POPC bilayers. The studied sterols included androstenol (i-C0-sterol) and cholesterol (i-C8-sterol), as well as four other derivatives (i-C5, i-C10, i-C12 and i-C14-sterol). For each sterol, both subtle local effects and more substantial differential alterations of membrane properties along the iso series were investigated. The location and orientation of the tetracyclic ring system is almost identical in all compounds. Among all the studied sterols, cholesterol is the sterol that presents the best matching with the hydrophobic length of POPC acyl chains, whereas longer-chained sterols interdigitate into the opposing membrane leaflet. In accordance with the experimental observations, a maximal ordering effect is observed for intermediate sterol chain length (i-C5, cholesterol, i-C10). Only for these sterols a preferential interaction with the saturated sn-1 chain of POPC (compared to the unsaturated sn-2 chain) was observed, but not for either shorter or longer-chained derivatives. This work highlights the importance of the sterol alkyl chain in the modulation of membrane properties and lateral organization in biological membranes