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We consider a large random network, in which the performance of a node depends upon that of its neighbours and some external random influence factors. This results in random vector valued fixed-point (FP) equations in large dimensional spaces, and our aim is to study their almost-sure solutions. An underlying directed random graph defines the connections between various components of the FP equations. Existence of an edge between nodes i, j implies the i-th FP equation depends on the j-th component. We consider a special case where any component of the FP equation depends upon an appropriate aggregate of that of the random 'neighbour' components. We obtain finite dimensional limit FP equations in a much smaller dimensional space, whose solutions aid to approximate the solution of FP equations for almost all realizations, as the number of nodes increases. We use Maximum theorem for non-compact sets to prove this convergence.We apply the results to study systemic risk in an example financial network with large number of heterogeneous entities. We utilized the simplified limit system to analyse trends of default probability (probability that an entity fails to clear its liabilities) and expected surplus (expected-revenue after clearing liabilities) with varying degrees of interconnections between two diverse groups. We illustrated the accuracy of the approximation using exhaustive Monte-Carlo simulations.Our approach can be utilized for a variety of financial networks (and others); the developed methodology provides approximate small-dimensional solutions to large-dimensional FP equations that represent the clearing vectors in case of financial networks. [ABSTRACT FROM AUTHOR]

A new carbazole-coupled tetrakis-(1 H-pyrrole-2-carbaldehyde) anion receptor 1 has been designed and synthesized. Anion binding studies in organic media using fluorescence and UV-vis spectroscopy revealed that receptor 1 is capable of sensing HP2O73- with high selectivity. Addition of HP2O73- to THF solution of 1 resulted in the emergence of a new broad band at longer wavelength along with quenching of the original emission band forming a ratiometric response. Based on dynamic light scattering (DLS) experiment and fluorescence lifetime measurement, we propose that the emergence of new emission band in the presence of HP2O73- ion is due to the aggregation-induced excimer formation. [ABSTRACT FROM AUTHOR]

We consider a financial network represented at any time instance by a random liability graph which evolves over time. The agents connect through credit instruments borrowed from each other or through direct lending, and these create the liability edges. These random edges are modified (locally) by the agents over time, as they learn from their experiences and (possibly imperfect) observations. The settlement of the liabilities of various agents at the end of the contract period (at any time instance) can be expressed as solutions of random fixed point equations. Our first step is to derive the solutions of these equations (asymptotically and one for each time instance), using a recent result on random fixed point equations. The agents, at any time instance, adapt one of the two available strategies, risky or less risky investments, with an aim to maximize their returns. We aim to study the emerging strategies of such replicator dynamics that drives the financial network. We theoretically reduce the analysis of the complex system to that of an appropriate ordinary differential equation (ODE). Using the attractors of the resulting ODE we show that the replicator dynamics converges to one of the two pure evolutionary stable strategies (all risky or all less risky agents); one can have mixed limit only when the observations are imperfect. We verify our theoretical findings using exhaustive Monte Carlo simulations. The dynamics avoid the emergence of the systemic-risk regime (where majority default). However, if all the agents blindly adapt risky strategy it can lead to systemic risk regime. [ABSTRACT FROM AUTHOR]

We study a scenario where both dark matter and heavy right handed neutrino (RHN) responsible for leptogenesis acquire masses by crossing the relativistic bubble walls formed as a result of a TeV scale supercooled first order phase transition (FOPT). While this leads to a large out-of-equilibrium abundance of right handed neutrino inside the bubble sufficient to produce the required lepton asymmetry, the dark matter being lighter can still remain in equilibrium with its relic being set by subsequent thermal freeze-out. A classical conformal symmetry ensures the origin of mass via FOPT induced by a singlet scalar while also ensuring supercooling leading to enhanced gravitational wave amplitude within the sensitivity of the LISA experiment. A minimal scenario with three RHN, one inert scalar doublet and one singlet scalar as additional fields beyond the standard model is sufficient to realize this possibility which also favours inert RHN dark matter over inert scalar doublet. [ABSTRACT FROM AUTHOR]

We have investigated the structural and magnetic properties of (Zn,Fe)Te:N thin films grown under Zn-rich condition with Fe composition fixed at 1.4% and N concentrations varying in the range [N] = 1.8 × 1018–5.1 × 1019 cm−3. Structural analysis by x-ray diffraction (XRD) detects some additional extrinsic diffraction peaks possibly from Fe-N compounds in the N-doped film with [N] = 5.1 × 1019 cm−3 only. Accordingly, x-ray absorption fine structure (XAFS) analysis reveals the shifting of Fe atoms from substitutional position for N-doped films with high N concentrations, [N] ≥ 1.8 × 1019 cm−3, whereas N-doped films with intermediate N concentrations [N] ≤ 4.3 × 1018 cm−3 are composed of pure diluted phase with substitutional Fe atoms in the valence state deviating from Fe2+. Magnetization measurement using SQUID confirms drastic change of magnetic properties; the linear dependence of magnetization on magnetic field, typical of van Vleck-type paramagnetism in the film without N-doping changes into room temperature ferromagnetic behaviors with hysteretic magnetization curves for N-doped films. The observed weak room temperature ferromagnetic behavior of the N-doped films with [N] ≤ 4.3 × 1018 cm−3 may reflect the deviation of substitutional Fe valence state from Fe2+ to Fe2+/3+ mixed states. On the other hand, the robust room temperature ferromagnetic behavior exhibited by N-doped films with [N] ≥ 1.8 × 1019 cm−3 may originate from precipitates of Fe-N compounds with Fe being in Fe2+/3+ or other valence state. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the uptake of hexavalent chromium from aqueous solutions by mosambi ( Citrus limetta) peel dust. A batch adsorption procedure was used to test the suitability of the fruit peel dust as an adsorbent for hexavalent chromium (reduction-coupled adsorption). The effect of different conditions, for example contact time, sorbate concentration, solution pH, and temperature, on sorption were investigated, and maximum uptake of hexavalent chromium from contaminated water was 250 mg g at pH 2.0 and 40 °C. Hexavalent chromium uptake from contaminated water followed a pseudo-first-order rate expression. Δ G, Δ H, and Δ S were evaluated and it was concluded that sorption was feasible, spontaneous, and endothermic in nature. The process is in good agreement with the Langmuir isotherm. The nature of possible adsorbent-metal ion interactions was examined by use of FTIR spectroscopy. This revealed the involvement in chromium binding of -OH, -NH, C=O, and C-O groups on the cell surfaces. This study indicated that mosambi peel can be used as an effective and environmentally friendly biosorbent for treatment of hexavalent chromium-containing contaminated water. Graphical Abstract: Hexavalent chromium compounds are more toxic than trivalent chromium because of their high water solubility and mobility. Mosambi ( Citrus limetta) peel effectively removes hexavalent chromium from contaminated water by reducing it to trivalent chromium.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Class II human leukocyte antigens (HLA II) are proteins involved in the human immunological adaptive response by binding and exposing some pre-processed, non-self peptides in the extracellular domain in order to make them recognizable by the CD4+ T lymphocytes. However, the understanding of HLA-peptide binding interaction is a crucial step for designing a peptide-based vaccine because the high rate of polymorphisms in HLA class II molecules creates a big challenge, even though the HLA II proteins can be grouped into supertypes, where members of different class bind a similar pool of peptides. Hence, first we performed the supertype classification of 27 HLA II proteins using their binding affinities and structural-based linear motifs to create a stable group of supertypes. For this purpose, a well-known clustering method was used, and then, a consensus was built to find the stable groups and to show the functional and structural correlation of HLA II proteins. Thus, the overlap of the binding events was measured, confirming a large promiscuity within the HLA II-peptide interactions. Moreover, a very low rate of locus-specific binding events was observed for the HLA-DP genetic locus, suggesting a different binding selectivity of these proteins with respect to HLA-DR and HLA-DQ proteins. Secondly, a predictor based on a support vector machine (SVM) classifier was designed to recognize HLA II-binding peptides. The efficiency of prediction was estimated using precision, recall (sensitivity), specificity, accuracy, F-measure, and area under the ROC curve values of random subsampled dataset in comparison with other supervised classifiers. Also the leave-one-out cross-validation was performed to establish the efficiency of the predictor. The availability of HLA II-peptide interaction dataset, HLA II-binding motifs, high-quality amino acid indices, peptide dataset for SVM training, and MATLAB code of the predictor is available at . [ABSTRACT FROM AUTHOR]

Chromic acid oxidation of dl-mandelic acid in the presence and absence of different promoters has been studied in aqueous media under the kinetic conditions [mandelic acid] ≫ [Cr(VI)] and [promoter] ≫ [Cr(VI)] at 30 °C. The promoters used in this oxidation reaction, picolinic acid (PA), 2,2′-bipyridine (bpy), and 1,10-phenanthroline (phen), are strong chelating ligands which form complexes with most transition metal ions. The reaction is first-order with regard to [H], [mandelic acid], and [Cr(VI)] and also has first-order dependence on [promoter]. HCrO was found to be kinetically active in the absence of promoters; in the presence of promoters the Cr(VI)-promoter complexes were believed to be the active oxidants. In this path the Cr(VI)-promoter complex in each case undergoes nucleophilic attack by the mandelic acid to form a ternary complex which subsequently undergoes redox decomposition involving 3 e transfer as the rate-determining step. Among the three promoters oxidation is much faster with 1,10-phenanthroline. [ABSTRACT FROM AUTHOR]

In this article, we categorize presently available experimental and theoretical knowledge of various physicochemical and biochemical features of amino acids, as collected in the AAindex database of known 544 amino acid (AA) indices. Previously reported 402 indices were categorized into six groups using hierarchical clustering technique and 142 were left unclustered. However, due to the increasing diversity of the database these indices are overlapping, therefore crisp clustering method may not provide optimal results. Moreover, in various large-scale bioinformatics analyses of whole proteomes, the proper selection of amino acid indices representing their biological significance is crucial for efficient and error-prone encoding of the short functional sequence motifs. In most cases, researchers perform exhaustive manual selection of the most informative indices. These two facts motivated us to analyse the widely used AA indices. The main goal of this article is twofold. First, we present a novel method of partitioning the bioinformatics data using consensus fuzzy clustering, where the recently proposed fuzzy clustering techniques are exploited. Second, we prepare three high quality subsets of all available indices. Superiority of the consensus fuzzy clustering method is demonstrated quantitatively, visually and statistically by comparing it with the previously proposed hierarchical clustered results. The processed AAindex1 database, supplementary material and the software are available at . [ABSTRACT FROM AUTHOR]

We present here the 2011 update of the AutoMotif Service (AMS 4.0) that predicts the wide selection of 88 different types of the single amino acid post-translational modifications (PTM) in protein sequences. The selection of experimentally confirmed modifications is acquired from the latest UniProt and Phospho.ELM databases for training. The sequence vicinity of each modified residue is represented using amino acids physico-chemical features encoded using high quality indices (HQI) obtaining by automatic clustering of known indices extracted from AAindex database. For each type of the numerical representation, the method builds the ensemble of Multi-Layer Perceptron (MLP) pattern classifiers, each optimising different objectives during the training (for example the recall, precision or area under the ROC curve (AUC)). The consensus is built using brainstorming technology, which combines multi-objective instances of machine learning algorithm, and the data fusion of different training objects representations, in order to boost the overall prediction accuracy of conserved short sequence motifs. The performance of AMS 4.0 is compared with the accuracy of previous versions, which were constructed using single machine learning methods (artificial neural networks, support vector machine). Our software improves the average AUC score of the earlier version by close to 7 % as calculated on the test datasets of all 88 PTM types. Moreover, for the selected most-difficult sequence motifs types it is able to improve the prediction performance by almost 32 %, when compared with previously used single machine learning methods. Summarising, the brainstorming consensus meta-learning methodology on the average boosts the AUC score up to around 89 %, averaged over all 88 PTM types. Detailed results for single machine learning methods and the consensus methodology are also provided, together with the comparison to previously published methods and state-of-the-art software tools. The source code and precompiled binaries of brainstorming tool are available at under Apache 2.0 licensing. [ABSTRACT FROM AUTHOR]

This study investigated whether homeless men are a bridge group for transmission of HIV to the general population in India. A cross-sectional study design was used to measure subjects’ past and current sexual activities. We surveyed 493 of 606 homeless men aged 18–49 years who live in public places in Kolkata, India, who were invited to take part in a structured interview, using a CD player and earphones. Almost two-thirds of respondents had never attended school. Sex with commercial sex worker (CSWs), multiple sex partners, and inconsistent condom use were common. About 90% of married homeless men visited CSWs, but only 3.3% consistently used condoms. AIDS awareness and risk perception were very low. Less education and being married but not currently living with wife were associated with high-risk sexual behaviors. Homeless men should be considered a potential bridge for HIV transmission from CSWs to the general population. Appropriate non-written communication strategies targeted to homeless people are urgently needed. Community intervention programs targeting the homeless, such as the ‘Popular Opinion Leader’ model, should be designed and evaluated. [ABSTRACT FROM AUTHOR]

A new carbazole-coupled tetrakis-(1 H-pyrrole-2-carbaldehyde) anion receptor 1 has been designed and synthesized. Anion binding studies in organic media using fluorescence and UV-vis spectroscopy revealed that receptor 1 is capable of sensing HP2O73- with high selectivity. Addition of HP2O73- to THF solution of 1 resulted in the emergence of a new broad band at longer wavelength along with quenching of the original emission band forming a ratiometric response. Based on dynamic light scattering (DLS) experiment and fluorescence lifetime measurement, we propose that the emergence of new emission band in the presence of HP2O73- ion is due to the aggregation-induced excimer formation. [ABSTRACT FROM AUTHOR]