Quick fixing ATL transformations with speculative analysis

Model transformations are central components of most model-based software projects. While ensuring their correctness is vital to guarantee the quality of the solution, current transformation tools provide limited support to statically detect and fix errors. In this way, the identification of errors and their correction are nowadays mostly manual activities which incur in high costs. The aim of this work is to improve this situation. Recently, we developed a static analyser that combines program analysis and constraint solving to identify errors in ATL model transformations. In this paper, we present a novel method and system that uses our analyser to propose suitable quick fixes for ATL transformation errors, notably some non-trivial, transformation-specific ones. Our approach supports speculative analysis to help developers select the most appropriate fix by creating a dynamic ranking of fixes, reporting on the consequences of applying a quick fix, and providing a pre-visualization of each quick fix application. The approach integrates seamlessly with the ATL editor. Moreover, we provide an evaluation based on existing faulty transformations built by a third party, and on automatically generated transformation mutants, which are then corrected with the quick fixes of our catalogue.     

Recommender systems in model-driven engineering

Software and Systems Modeling - Recommender systems are information filtering systems used in many online applications like music and video broadcasting and e-commerce platforms. They are also...     

Kinetics and modified clay thermodynamic from the Brazilian amazon region for lead removal

Modified Brazilian smectite-bearing clay samples displayed ability for lead adsorption. The structure modification of smectite were obtained through pillaring process and functionalization with [3-(2-aminoethylamino)propyl]trimethoxysilane. The chemical modification process increases the basal spacing of the natural smectite from 1.354 to 2.364 nm. The Langmuir model was fitted to experimental data in linear regression. Kinetic studies showed an equilibrium adsorption time of 700 min on the modified clay. The experimental data were correlated with two distinct kinetic models were used: (i) external mass transfer diffusion and (ii) intraparticular mass transfer diffusion. However, the intraparticle mass transfer diffusion model gave a better fit to these experimental data. The energetic effects caused by lead interactions were determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.     

Comparative B‐mode and Doppler renal ultrasonography with histopathological findings in dogs positive for canine visceral leishmaniasis

Morphological parameters and renal flow were assessed and measured in six clinically healthy dogs with negative serological and parasitological examinations for canine visceral leishmaniasis (CVL) and six dogs with CVL‐positive serological and parasitological tests and asymptomatic condition of the disease. Kidney length and diameter were measured and compared with the aorta/kidney ratio. Alterations in flow were measured using the flow velocity (cm/s) and resistance index (RI). Renal function was assessed by serum biochemical examination (urea, creatine, total proteins, albumin, and globulin) and urinalysis. CVL‐positive animals presented heterogeneous kidney echotexture, reduced vascular flow, hypoperfusion, lesser visualization of the arcuate arteries, high RI values (1.06 ± 0.28 for the right kidney and 1.10 ± 0.30 for the left kidney), reduced diastolic flow, and high systolic peak. They also presented positive creatine/RI correlation and between the renal artery vascular flow and kidney diameter. Histopathological analysis of CVL‐positive animals was compatible and confirmed hemodynamic changes observed by Doppler ultrasound. The findings in the present study showed that Doppler ultrasonography is a valid method to assess and detect alterations in flow in renal pathological processes with kidney vascular damage, as in the case of leishmaniasis, and can help in the diagnosis of animals with this infection. Microsc. Res. Tech. 79:637–645, 2016. © 2016 Wiley Periodicals, Inc.     

Composites Between Alumina and an Ester‐Ether‐Ester Bioresorbable Copolymer

Composites between alumina and the bioresorbable poly(ε‐caprolactone)‐block‐poly(oxyethylene)‐block‐poly(ε‐caprolactone) copolymer were obtained by reacting ε‐caprolactone with preformed poly(ethylene glycol), in the presence of ceramic alumina powder, at 185°C under vacuum. The mechanical properties, tested by compression and flexural strengths and Young's modulus, show that the copolymer interacts poorly with the alumina grains. Both scanning electron and atomic force microscopy show a scarce wettability between alumina and copolymer, as well as the aggregation of alumina micro‐particles into clusters of big size. Both mechanical and morphological tests seem to indicate a stronger interaction between the alumina micro‐particles than between the alumina surface and the reaction mixture during the polymerization, as well as a “compacting effect” by alumina on the forming copolymer. The FT‐IR spectra of the composites show both copolymer and alumina absorption bands. The FT‐IR analysis on the fractions of an extraction with CHCl₃ indicates the presence of traces of poly(ε‐caprolactone), stably linked to alumina. The polymerization of ε‐caprolactone with alumina alone in the same conditions gives poly(ε‐caprolactone), mainly free and in minor part linked to the alumina surface. Two polymerization mechanisms, simultaneously occurring, are proposed. The most relevant result of this work is the lack of chemical inertness of alumina towards ε‐caprolactone, which leads to reconsider also the use of alumina as a biochemically inert material.     

Poly(ester amide)s derived from tartaric and succinic acids: Changes in structure and properties upon hydrolytic degradation

The changes in structure and properties taking place in a set of tartaric acid‐based polyamides and poly(ester amide)s upon hydrolytic degradation were examined. Poly(hexamethylene 2,3‐di‐O‐methyl‐L ‐tartaramide)s, either pure or containing minor amounts of succinate ester groups (≤10%), were exposed to humidity or incubated in buffered water at pH 7.4 and 37°C, and their thermal and mechanical properties were evaluated as a function of time. Both moisture uptake and hydrolysis induced a noticeable decay in the tensile properties of polymers. These effects were greatly enhanced by the presence of ester groups, whereas no large differences were noticed for changes in the enantiomeric composition. Variations in the glass transition temperatures and melting points appeared to be slight, whereas crystallinity clearly increased with incubation time. The latter effect was most apparent in poly(ester amide)s with a nearly racemic composition, in which a crystal‐to‐crystal transition was observed to take place upon degradation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 486–494, 2000     

Effect of Cobalt and Chromium Ions on the Chlorhexidine Digluconate as Seen by Intermolecular Diffusion

Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl₂ (and CrCl₃) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D₁₂ and D₂₁. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth.     

Endothelial Progenitor Cells and Rheumatoid Arthritis: Response to Endothelial Dysfunction and Clinical Evidences

Rheumatoid Arthritis (RA) is a chronic autoimmune inflammatory disease characterized by the swelling of multiple joints, pain and stiffness, and accelerated atherosclerosis. Sustained immune response and chronic inflammation, which characterize RA, may induce endothelial activation, damage and dysfunction. An equilibrium between endothelial damage and repair, together with the preservation of endothelial integrity, is of crucial importance for the homeostasis of endothelium. Endothelial Progenitor Cells (EPCs) represent a heterogenous cell population, characterized by the ability to differentiate into mature endothelial cells (ECs), which contribute to vascular homeostasis, neovascularization and endothelial repair. A modification of the number and function of EPCs has been described in numerous chronic inflammatory and auto-immune conditions; however, reports that focus on the number and functions of EPCs in RA are characterized by conflicting results, and discrepancies exist among different studies. In the present review, the authors describe EPCs’ role and response to RA-related endothelial modification, with the aim of illustrating current evidence regarding the level of EPCs and their function in this disease, to summarize EPCs’ role as a biomarker in cardiovascular comorbidities related to RA, and finally, to discuss the modulation of EPCs secondary to RA therapy.     

Heat–Moisture Treatment on Pinhão Starch Impacts the Properties of the Biodegradable Films

Using non-conventional starch can benefit the industry since it can present different properties. It also can lead to new properties upon physical modification, which improves its derivate film properties. Therefore, the aim of this work is to evaluate the heat–moisture treatment (HMT) on pinhão starch and its effectiveness in film properties. After isolation using water as a solvent, the pinhão starch is treated by HMT for 16 h at 110 °C. Native and HMTed starches are used to produce biodegradable films. Pinhão starch and starch films chemical and physical properties are properly characterized. The HMT causes some changes in short-range ordered structures, reduces the relative crystallinity, and shifts the pinhão starch from C-type to A-type. Also, HMT decreases the peak viscosity and the breakdown, and improves thermal stability. These starch changes upon HMT reduces water vapor permeability, increases tensile strength, and elongation at the break of pinhão starch films. Desirable changes in starch and film properties are achieved by physically modifying pinhão starch using HMT, which is a promising alternative to chemical modifications.