A comparative study on the performance of dissortative mating and immigrants-based strategies for evolutionary dynamic optimization

Traditional Genetic Algorithms (GAs) mating schemes select individuals for crossover independently of their genotypic or phenotypic similarities. In Nature, this behavior is known as random mating. However, non-random protocols, in which individuals mate according to their kinship or likeness, are more common in natural species. Previous studies indicate that when applied to GAs, dissortative mating - a type of non-random mating in which individuals are chosen according to their similarities - may improve their performance (on both speed and reliability). Dissortative mating maintains genetic diversity at a higher level during the run, a fact that is frequently observed as a possible cause of dissortative GAs’ ability to escape local optima. Dynamic optimization demands a special attention when designing and tuning a GA, since diversity plays an even more crucial role than it does when tackling static ones. This paper investigates the behavior of the Adaptive Dissortative Mating GA (ADMGA) in dynamic problems and compares it to GAs based on random immigrants. ADMGA selects parents according to their Hamming distance, via a self-adjustable threshold value. The method, by keeping population diversity during the run, provides an effective means to deal with dynamic problems. Tests conducted with dynamic trap functions and dynamic versions of Road Royal and knapsack problems indicate that ADMGA is able to outperform other GAs on a wide range of tests, being particularly effective when the frequency of changes is low. Specifically, ADMGA outperforms two state-of-the-art algorithms on many dynamic scenarios. In addition, and unlike preceding dissortative mating GAs and other evolutionary techniques for dynamic optimization, ADMGA self-regulates the intensity of the mating restrictions and does not increase the set of parameters in GAs, thus being easier to tune.     

Type of milk consumed can influence plasma concentrations of fatty acids and minerals and body composition in infant and weanling pigs

Two experiments using 42 crossbred neonatal pigs to compare the effects of caprine and bovine milk on growth, apparent nutrient digestibility and body composition were conducted. At age 72 h, pigs were removed from their dams and randomly divided into two groups, housed separately in stainless steel metabolism cages and were fed a predetermined amount (300 mL/kg body weight) of pasteurized, nonfortified whole, caprine or bovine milk. Body composition was determined using dual energy X-ray absorptiometry (DXA). In Experiment 1, 22 intact male pigs were used for a 31-d experimental period. There was no significant (P > 0.05) dietary effect on growth, apparent nutrient digestibility or body composition. Significant differences (P < 0.05), however, were observed in plasma of C 8:0, C 10:0 and C 12:0 concentrations. In Experiment 2, 20 pigs (10 intact males and 10 females) were used in a 2 x 2 factorial experiment for 52 d. Pigs fed caprine milk had higher (P < 0.05) plasma concentrations of C10:0 and C12:0 as well as Na, Mg and Zn than those fed bovine milk. At Day 52, pigs fed caprine milk had less body fat (P < 0.001) and higher (P < 0.06) bone mineral density than those fed bovine milk. Drymatter, N and total mineral intake of male pigs was higher (P < 0.05) than female pigs. Also, male pigs had higher (P < 0.05) plasma concentrations of C12:0 than females. This study demonstrates that the type of milk consumed can influence plasma concentrations of fatty acids, minerals and body composition in pigs.     

Induction of apoptosis and apoptotic mediators in balb/C splenic lymphocytes by dietary n−3 and n−6 fatty acids

The present study was designed to investigate the effect of diatery n−6 and n−3 polyunsaturated fatty acids (PUFA) on anti-CD3 and anti-Fas antibody-induced apoptosis and its mediators in mouse spleen cells. Nutritionally adequate semipurified diets containing either 5% w/w corn oil (n−6 PUFA) or fish oil (n−3 PUFA) were fed to weanling female Balb/C mice, and 24 wk later mice were sacrificed. In n−3 PUFA-fed mice, serum and splenocyte lipid peroxides were increased by 20 and 28.3% respectively, compared to n−6 PUFA-fed mice. Further, serum vitamin F levels were decreased by 50% in the n−3 PUFA-fed group, whereas higher anti0Fas- and anti-CD3-induced apoptosis (65 and 66%) and necrosis (17 and 25%), compared to the n−6 PUFA-fed group, were found when measured with Annexin V and propidium iodide staining, respectively. In addition, decreased Bcl-2 and increased Fas-ligand (Fas-L) also were observed in the n−3 PUFA-fed group compared to the n−6 PUFA-fed group. No difference in the ratio of splenocyte subsets nor their Fas expression was observed between the n−3 PUFA-fed and n−6 PUFA-fed groups, whereas decreased proliferation of splenocytes was found in n−3 PUFA-fed mice compared to n−6 PUFA-fed mice. In conclusion, our results indicate that dietary n−3 PUFA induces higher apoptosis by increasing the generation of lipid peroxides and elevating Fas-L expression along with decreasing Bcl-2 expression. A reduced proliferative response of immune cells also was observed in n−3 PUFA-fed mice.     

Firefly luciferase produces hydrogen peroxide as a coproduct in dehydroluciferyl adenylate formation

Firefly luciferase catalyzes the synthesis of H2O2 from the same substrates as the bioluminescence reaction: ATP and luciferin (D-LH2). About 80% of the enzyme-bound intermediate D-luciferyl adenylate (D-LH2-AMP) is oxidized into oxyluciferin, and a photon is emitted during this reaction. The enzyme pathway responsible for the generation of H2O2 is a side reaction in which D-LH2-AMP is oxidized into dehydroluciferyl adenylate (L-AMP). Like the bioluminescence reaction, the luciferase-catalyzed synthesis of H2O2 and L-AMP is a stereospecific process, involving only the natural D enantiomer. However, the intramolecular electron transfer postulated as essential to the light emission process is not involved in this side reaction.     

General contribution of nonspecific interactions to fluorescence intensity

Many chemical compounds, including nonfluorescent ones, induce changes in the fluorescence spectra of certain probes, such as berberine cation and Reichardt's betaine, both in the absence and the presence of solvent, that affect almost exclusively emission intensity. In this work, the application of fluorescence detection by intensity changes (FDIC) to HPLC and TLC chromatographic systems with fluorescence detectors has been studied. FDIC detection is of special interest in detecting nonfluorescent analytes, either in HPLC or in TLC mode. It does not involve covalent interactions, and the dielectric permittivity (epsilon) of the medium plays an important role. The balance between nonspecific and specific interactions produces either an increase or a decrease in fluorescence intensity. Therefore, the influence of chromatographic conditions and chemical structure of analytes on the sign and magnitude of fluorescence peaks for sample detection in HPLC and TLC systems has been discussed. In general, probe nature and concentration determine response and detection sensitivity for a given sample in TLC and HPLC. As solubility and fluorescence properties in solvents determine the operating conditions for a FDIC probe in HPLC mode, nature and flows of mobile phase and solvent are important for chromatographic response and detection sensitivity.     

A single point mutation controls the cholesterol dependence of Semliki Forest virus entry and exit

Hypergastrinaemia-associated changes of non-antral argyrophil cells in man are of increasing interest, because of the development of potent inhibitors of gastric acid secretion. Using an antibody against chromogranin A, we identified micronodular endocrine cell hyperplasia of the oxyntic mucosa in gastric biopsy specimens of patients with hypergastrinaemia of different backgrounds. Consecutive ultrathin sections were examined at the electron-microscopical level. Endocrine cell types within the (extraepithelial) micronodules closely resembled those in the adjacent mucosa. Micronodules were classified into two groups. The first group was composed of endocrine cells only and predominated in patients with drug-induced hypergastrinaemia and/or chronic gastritis, and in a gastrinoma/MEN I patient. The second group represented "neuroendocrine complexes", showing a close intermingling of non-myelinated nerve fibres with endocrine cells, and was found predominantly in pernicious anaemia. Micronodular argyrophil cell growth in man is therefore heterogeneous and depends on the background of the hypergastrinaemia.     

Crowdsourcing for data management

The discovery of informative itemsets is a fundamental building block in data analytics and information retrieval. While the problem has been widely studied, only few solutions scale. This is particularly the case when (1) the data set is massive, calling for large-scale distribution, and/or (2) the length k of the informative itemset to be discovered is high. In this paper, we address the problem of parallel mining of maximally informative k-itemsets (miki) based on joint entropy. We propose PHIKS (Parallel Highly Informative \(\underline{K}\)-ItemSet), a highly scalable, parallel miki mining algorithm. PHIKS renders the mining process of large-scale databases (up to terabytes of data) succinct and effective. Its mining process is made up of only two efficient parallel jobs. With PHIKS, we provide a set of significant optimizations for calculating the joint entropies of miki having different sizes, which drastically reduces the execution time, the communication cost and the energy consumption, in a distributed computational platform. PHIKS has been extensively evaluated using massive real-world data sets. Our experimental results confirm the effectiveness of our proposal by the significant scale-up obtained with high itemsets length and over very large databases.     

Monitoring Methodology of Interventions for Riverbanks Stabilization: Assessment of Technical Solutions Performance

The success of the river rehabilitation process depends not only on the intervention project but also on the attention given to the monitoring and evaluation of the implemented measures. In spite of the recent efforts on the quantification and sharing of interventions’ results, there are still very few written records documenting that information. The present work proposes a monitoring methodology for riverbanks’ stabilization interventions by comparing the results obtained by monitoring the implemented technical solutions with the corresponding theoretical time-expected performance. For this purpose, two case studies located in the south of Portugal were analysed. For each of those case studies, the dominant factors that influenced the temporal evolution of the observed outcomes were assessed. It was possible to verify that, depending on the implemented technical solution type and on the specific characteristics of the intervention site, monitoring actions can be fundamental to achieve the expected technical and ecological efficiency, namely when bioengineering technical solutions are involved. This work led to the development of a database structure that will gather information on the application of the proposed methodology over time and that shall be improved with the analysis of the behaviour of other riverbanks’ stabilization interventions. The development of this database will surely contribute to enable choosing and applying the most adequate riverbank protection solutions.     

Development of ceramic floor tile compositions based on quartzite and granite sludges

In the present work, industrial sludges derived from cutting and polishing natural stones (granite and quartzite) were characterised in terms of particles size distribution, chemical and mineralogical composition, and thermal behaviour and their potential to be incorporated as main components in red-clay-based stoneware tiles was evaluated. High levels (60–70 wt.%) of incorporation were attempted aiming at designing new formulations intended to be less expensive and possess better final properties (lower water absorption and higher flexural strength) in comparison to an industrial reference body used in the production of rustic tiles by extrusion, characterised 8–9% water absorption and a flexural strength of 17–18 MPa. Extruded rods of different formulations were produced and fired at 1100 °C, 1125 °C, 1150 °C and 1200 °C. The experimental results showed that all the new formulations performed better with the most significant improvements being obtained with incorporation of granite sludge. Flexural strength values more than triplicate and water absorption decreased by more than one order of magnitude in comparison to the reference paste. The new products fulfil the requirements of the ISO 13006 standard, group BIa (porcelain tiles).     

In Situ Phase Evolution of Ni/Ti Reactive Multilayers

Joining shape-memory alloys (SMA) to other materials is strongly required in order to enlarge their fields of application. Fusion welding induces strong compositional and microstructural changes that significantly affect the shape-memory effect and the superelastic behavior of these alloys. The exothermic and in some cases self-propagating character of some nano-multilayer reactions is explored in this study as an alternative for joining SMA. To follow these very fast reactions, high brilliance sources, such as synchrotron radiation, are required. In situ high-resolution x-ray diffraction data, giving the phase evolution sequence with temperature of the Ni/Ti multilayer thin films under study, are presented. A correlation between the multilayer design and the tendency for the sequence of phase formation is established.