Phase transition and landscape statistics of the number partitioning problem

The phase transition in the number partitioning problem (NPP), i.e., the transition from a region in the space of control parameters in which almost all instances have many solutions to a region in which almost all instances have no solution, is investigated by examining the energy landscape of this classic optimization problem. This is achieved by coding the information about the minimum energy paths connecting pairs of minima into a tree structure, termed a barrier tree, the leaves and internal nodes of which represent, respectively, the minima and the lowest energy saddles connecting those minima. Here we apply several measures of shape (balance and symmetry) as well as of branch lengths (barrier heights) to the barrier trees that result from the landscape of the NPP, aiming at identifying traces of the easy/hard transition. We find that it is not possible to tell the easy regime from the hard one by visual inspection of the trees or by measuring the barrier heights. Only the {\it difficulty} measure, given by the maximum value of the ratio between the barrier height and the energy surplus of local minima, succeeded in detecting traces of the phase transition in the tree. In adddition, we show that the barrier trees associated with the NPP are very similar to random trees, contrasting dramatically with trees associated with the $p$ spin-glass and random energy models. We also examine critically a recent conjecture on the equivalence between the NPP and a truncated random energy model

Ecology and parasitism of the lizard Tropidurus jaguaribanus (Squamata: Tropiduridae) from northeastern Brazil

Ecology and parasitism of the lizard Tropidurus jaguaribanus (Squamata: Tropiduridae) from northeastern Brazil. Specimens of Tropidurus jaguaribanus were collected as part of a study of their use of microhabitats, activity period, body temperature, diet, foraging, sexual dimorphism (in size and in form), reproductive biology, and parasite community composition. The preferential microhabitat of the species is the surface of rocks (saxicolous habit). The species has a bimodal diurnal activity period and a seasonal reproductive cycle. The diet is composed mainly of beetles and ants in adults and juveniles. The species is a sit-and-wait forager; the lizards scarcely move and feed on sedentary, immobile prey. The helminth community associated with these lizards is composed of fve species: Oochoristica travassosi, Parapharyngodon alvarengai, Physaloptera sp., Spauligodon sp., and Strongyluris oscari. The prevalence, intensity of infection, and parasite abundance is the same in both sexes.Ecologia e parasitismo do lagarto Tropidurus jaguaribanus (Squamata: Tropiduridae) do nordeste do Brasil. Espécimes de Tropidurus jaguaribanus foram coletados como parte de um estudo de uso de micro-hábitats, período de atividade, temperatura corporal, dieta, forrageamento, dimorfsmo sexual (tamanho e forma), biologia reprodutiva e composição da comunidade parasitária. O micro-hábitat preferencial da espécie é a superfície das rochas (hábito saxícola). A espécie possui um período de atividade diurna bimodal e um ciclo reprodutivo sazonal. A dieta é composta principalmente por besouros e formigas em adultos e juvenis. A espécie é um forrageador senta-eespera; os lagartos movem-se pouco e alimentam-se de presas sedentárias e imóveis. A comunidade de helmintos associada a esses lagartos é composta por cinco espécies: Oochoristica travassosi, Parapharyngodon alvarengai, Physaloptera sp., Spauligodon sp. e Strongyluris oscari. A prevalência, a intensidade da infecção e a abundância de parasitas são as mesmas em ambos os sexos

New banking trends, MCDA and financial decisions: insights and a framework for retail banking

Since most decision making involves multiple criteria, extensive research has been developed in this area over the past few decades. However, as it is widely known in the decision-making field, there are significant differences in the way that the decision-making process has been addressed. This has lead to two different approaches: Multiple Criteria Decision Making (MCDM) and Multiple Criteria Decision Analysis (or Aid) (MCDA). Having the most recent world economic and financial trends as a background, this paper aims to highlight the relationship between MCDA and financial decisions in a banking context. The paper is based on previous work of well-known authors in the financial decisionmaking field, but highlights new findings and presents a multicriteria framework for retail banking in order to increase the interest of the MCDA approach for banking issues. In particular, the framework offers a holistic view of banking activities at a bank branch level, where at least eight different phases, when correctly integrated and performed, provide banks with a greater capacity to support decisions and to adapt strategies to a permanent changing environment. The paper discusses insights, advantages and disadvantages of MCDA to provide recommendations for successful applications of this approach in similar contexts

The Genomic Architecture of Population Divergence between Subspecies of the European Rabbit

The analysis of introgression of genomic regions between divergent populations provides an excellent opportunity to determine the genetic basis of reproductive isolation during the early stages of speciation. However, hybridization and subsequent gene flow must be relatively common in order to localize individual loci that resist introgression. In this study, we used next-generation sequencing to study genome-wide patterns of genetic differentiation between two hybridizing subspecies of rabbits (Oryctolagus cuniculus algirus and O. c. cuniculus) that are known to undergo high rates of gene exchange. Our primary objective was to identify specific genes or genomic regions that have resisted introgression and are likely to confer reproductive barriers in natural conditions. On the basis of 326,000 polymorphisms, we found low to moderate overall levels of differentiation between subspecies, and fewer than 200 genomic regions dispersed throughout the genome showing high differentiation consistent with a signature of reduced gene flow. Most differentiated regions were smaller than 200 Kb and contained very few genes. Remarkably, 30 regions were each found to contain a single gene, facilitating the identification of candidate genes underlying reproductive isolation. This gene-level resolution yielded several insights into the genetic basis and architecture of reproductive isolation in rabbits. Regions of high differentiation were enriched on the X-chromosome and near centromeres. Genes lying within differentiated regions were often associated with transcription and epigenetic activities, including chromatin organization, regulation of transcription, and DNA binding. Overall, our results from a naturally hybridizing system share important commonalities with hybrid incompatibility genes identified using laboratory crosses in mice and flies, highlighting general mechanisms underlying the maintenance of reproductive barriers

Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)

Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade

Fractal geometry of spin-glass models

Stability and diversity are two key properties that living entities share with spin glasses, where they are manifested through the breaking of the phase space into many valleys or local minima connected by saddle points. The topology of the phase space can be conveniently condensed into a tree structure, akin to the biological phylogenetic trees, whose tips are the local minima and internal nodes are the lowest-energy saddles connecting those minima. For the infinite-range Ising spin glass with p-spin interactions, we show that the average size-frequency distribution of saddles obeys a power law $\sim w^{-D}$, where w=w(s) is the number of minima that can be connected through saddle s, and D is the fractal dimension of the phase space

Antioxidant potential of two red seaweeds from the Brazilian coasts

In this work, in vitro antioxidant activity of two Brazilian red seaweeds, Gracilaria birdiae and Gracilaria cornea, was characterized. The total phenolic content, the radical-scavenging activity and the antioxidant activity were determined in two solvent extracts of the algae. Liquid chromatography mass spectrometry (LC MS/MS) allowed identification of important antioxidant compounds. The ethanol extract of G. birdiae was found to have the highest value of total phenolic content: 1.13 mg of gallic acid equiv (GAE)/g of extract.The radical-scavenging activity of G. birdiae and G. cornea extracts has been evaluated at different extract concentrations; the IC50 values of ethanolic extracts of G. cornea and G. birdiae were 0.77 and 0.76mgmL 1, respectively, while formethanolic extracts, the IC50 values of G. cornea and G. birdiae were 0.86 and 0.76mgmL 1, respectively. The antioxidant activities of these two seaweeds’ extracts as assessed by the ß-carotene linoleic acid assay were equally high, achieving values of ß-carotene oxidation inhibition of up to 40%. Finally, in the methanolic extracts, LC MS/MS allowed identification in both algae of two important antioxidants: apigenin and gallic acid.B.W.S.S. is the recipient of a fellowship from the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brazil) M.A.C. and J.T.M. are recipients of fellowships from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal) (SFRH/BD/23897/2005 and SFRH/BD/32566/2006, respectively)

Dual target strategy: a proposal to mitigate the risk of overtreatment and enhance patient satisfaction in rheumatoid arthritis

Commentary - abstract not available

Enhancing the bioconversion of winery and olive mill waste mixtures into lignocellulolytic enzymes and animal feed by Aspergillus uvarum using a packed-bed bioreactor

Wineries and olive oil industries are dominant agro-industrial activities in southern European regions. Olive pomace, exhausted grape marc and vine shoot trimmings are lignocellulosic residues generated by these industries, which could be valued biotechnologically. In the present work these residues were used as substrate to produce cellulases and xylanases through solid-state fermentation using Aspergillus uvarum. For that, two factorial designs (32) were first planned to optimize substrate composition, temperature and initial moisture level. Subsequently, the kinectics of cellulolytic enzymes production, fungal growth and fermented solid were characterized, Finally, the process was performed in a packed-bed bioreactor. The results showed that cellulase activity improved with the optimization processes, reaching 33.56 U/g, and with the packed-bed bioreactor aeration of 0.2 L/min, reaching 38.51 U/g. The composition of fermented solids indicated their potential use for animal feed because cellulose, hemicellulose, lignin and phenolic compounds were partially degraded 28.08, 10.78, 13.3 and 28.32% respectively, crude protein was increased from 8.47% to 17.08%, and, the mineral contents meet the requirements of main livestock.J.M.S. was supported by Grant SFRH/BPD/84440/2012 from Fundacao para a Ciencia e Tecnologia (FCT), Portugal. L.A. was supported by Grant Incentivo/EQB/LA0023/2014 from O Novo Norte (ON.2). We thank FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, Rer. NORTE-07-0124-FEDER-000028" co-funded by the Programa Operacional Regional do Norte (ON.2), QREN, FEDE

Self-assembled RGD dehydropeptide hydrogels for drug delivery applications

Peptide-based self-assembled hydrogels have triggered remarkable research interest in recent years owing to their biocompatibility and biomimetic properties and responsiveness, which warrant many technological and biomedical applications. Dehydrodipeptides N-capped with naproxen emerged from our research as effective hydrogelators endowed with resistance to proteolysis. Dehydrodipeptide-based hydrogels are promising nanocarriers for drug delivery applications. In this work, we demonstrate that dehydrodipetide Npx-L-Ala-Z-ΔPhe-OH can be deployed as a minimalist hydrogelator module for synthesizing a gelating construct Npx-L-Ala-Z-ΔPhe-G-R-G-D-G-OH bearing a GRGDG adhesion motif. The self-assembly of the peptide construct and the drug delivery properties of the hydrogel were studied in this work. The peptide construct showed no toxicity towards a fibroblast cell line expressing the αvβ3 integrin. Docking studies suggest that the hydrogelator block does not interfere with the recognition of the RGD motif by the integrin receptor. The self-assembly seems to be directed by intermolecular naphthalene π–π stacking interactions, with the peptide backbone assuming a random coil conformation both in solution and in the gel phase. TEM and STEM imaging revealed that the hydrogel is made of entangled bundles of long thin fibres (width circa 23 nm). The hydrogel exhibits viscoelastic properties, thermo-reversibility and recovery after mechanical fluidization. FRET studies showed that curcumin incorporated into the hydrogel interacts non-covalently with the hydrogel fibrils. Delivery of curcumin from the hydrogel into Nile red loaded model membranes (SUVs) was demonstrated by FRET. Naproxen N-capped dehydrodipeptides are efficacious minimalist hydrogelator modules for obtaining hydrogels functionalized with peptide ligands for cell receptors. These hydrogels are potential nanocarriers for drug delivery