Tungsten-based nanomaterials (WO3 & Bi2WO6): Modifications related to charge carrier transfer mechanisms and photocatalytic applications

Heterogeneous photocatalysis is an ideal green energy technology for the purification of wastewater. Although titania dominates as the reference photocatalyst, its wide band gap is a bottleneck for extended utility. Thus, search for non-TiO2 based nanomaterials has become an active area of research in recent years. In this regard, visible light absorbing polycrystalline WO3 (2.4-2.8 eV) and Bi2WO6 (2.8 eV) with versatile structure-electronic properties has gained considerable interest to promote the photocatalytic reactions. These materials are also explored in selective functional group transformation in organic reactions, because of low reduction and oxidation potential of WO3 CB and Bi2WO6 VB, respectively. In this focused review, various strategies such as foreign ion doping, noble metal deposition and heterostructuring with other semiconductors designed for efficient photocatalysis is discussed. These modifications not only extend the optical response to longer wavelengths, but also prolong the life-time of the charge carriers and strengthen the photocatalyst stability. The changes in the surface-bulk properties and the charge carrier transfer dynamics associated with each modification correlating to the high activity are emphasized. The presence of oxidizing agents, surface modification with Cu2+ ions and synthesis of exposed facets to promote the degradation rate is highlighted. In depth study on these nanomaterials is likely to sustain interest in wastewater remediation and envisaged to signify in various green energy applications. (C) 2015 Elsevier B.V. All rights reserved.

Necessary and sufficient conditions for optimality in constrained general sum stochastic games

In this paper we first derive a necessary and sufficient condition for a stationary strategy to be the Nash equilibrium of discounted constrained stochastic game under certain assumptions. In this process we also develop a nonlinear (non-convex) optimization problem for a discounted constrained stochastic game. We use the linear best response functions of every player and complementary slackness theorem for linear programs to derive both the optimization problem and the equivalent condition. We then extend this result to average reward constrained stochastic games. Finally, we present a heuristic algorithm motivated by our necessary and sufficient conditions for a discounted cost constrained stochastic game. We numerically observe the convergence of this algorithm to Nash equilibrium. (C) 2015 Elsevier B.V. All rights reserved.

Kinematics and dynamics of Jansen leg mechanism: A bond graph approach

The Jansen mechanism is a one degree-of-freedom, planar, 12-link, leg mechanism that can be used in mobile robotic applications and in gait analysis. This paper presents the kinematics and dynamics of the Jansen leg mechanism. The forward kinematics, accomplished using circle intersection method, determines the trajectories of various points on the mechanism in the chassis (stationary link) reference frame. From the foot point trajectory, the step length is shown to vary linearly while step height varies non-linearly with change in crank radius. A dynamic model for the Jansen leg mechanism is proposed using bond graph approach with modulated multiport transformers. For given ground reaction force pattern and crank angular speed, this model helps determine the motor torque profile as well as the link and joint stresses. The model can therefore be used to rate the actuator torque and in design of the hardware and controller for such a system. The kinematics of the mechanism can also be obtained from this dynamic model. The proposed model is thus a useful tool for analysis and design of systems based on the Jansen leg mechanism. (C) 2015 Elsevier B.V. All rights reserved.

Genomic amplification upregulates estrogen-related receptor alpha and its depletion inhibits oral squamous cell carcinoma tumors in vivo

The ESRRA gene encodes a transcription factor and regulates several genes, such as WNT11 and OPN, involved in tumorigenesis. It is upregulated in several cancers, including OSCC. We have previously shown that the tumor suppressor miR-125a targets ESRRA, and its downregulation causes upregulation of ESRRA in OSCC. Upregulation of ESRRA in the absence of downregulation of miR-125a in a subset of OSCC samples suggests the involvement of an alternative mechanism. Using TaqMan (R) copy number assay, here we report for the first time that the genomic amplification of ESRRA causes its upregulation in a subset of OSCC samples. Ectopic overexpression of ESRRA led to accelerated cell proliferation, anchorage-independent cell growth and invasion, and inhibited apoptosis. Whereas, knockdown of ESRRA expression by siRNA led to reduced cell proliferation, anchorage-independent cell growth and invasion, and accelerated apoptosis. Furthermore, the delivery of a synthetic biostable ESRRA siRNA to OSCC cells resulted in regression of xenografts in nude mice. Thus, the genomic amplification of ESRRA is another novel mechanism for its upregulation in OSCC. Based on our in vitro and in vivo experiments, we suggest that targeting ESRRA by siRNA could be a novel therapeutic strategy for OSCC and other cancers.

Characterization of type I interferon pathway during hepatic differentiation of human pluripotent stem cells and hepatitis C virus infection

Pluripotent stem cells are being actively studied as a cell source for regenerating damaged liver. For long-term survival of engrafting cells in the body, not only do the cells have to execute liver-specific function but also withstand the physical strains and invading pathogens. The cellular innate immune system orchestrated by the interferon (IFN) pathway provides the first line of defense against pathogens. The objective of this study is to assess the innate immune function as well as to systematically profile the IFN-induced genes during hepatic differentiation of pluripotent stem cells. To address this objective, we derived endodermal cells (day 5 post-differentiation), hepatoblast (day 15) and hepatocyte-like cells (day 21) from human embryonic stem cells (hESCs). Day 5, 15 and 21 cells were stimulated with IFN-alpha and subjected to IFN pathway analysis. Transcriptome analysis was carried out by RNA sequencing. The results showed that the IFN-alpha treatment activated STAT-JAK pathway in differentiating cells. Transcriptome analysis indicated stage specific expression of classical and non-classical IFN-stimulated genes (ISGs). Subsequent validation confirmed the expression of novel ISGs including RASGRP3, CLMP and TRANK1 by differentiated hepatic cells upon IFN treatment. Hepatitis C virus replication in hESC-derived hepatic cells induced the expression of ISGs - LAMP3, ETV7, RASGRP3, and TRANK1. The hESC-derived hepatic cells contain intact innate system and can recognize invading pathogens. Besides assessing the tissue-specific functions for cell therapy applications, it may also be important to test the innate immune function of engrafting cells to ensure adequate defense against infections and improve graft survival. (C) 2015 The Authors. Published by Elsevier B.V.

Speaker verification based on the fusion of speech acoustics and inverted articulatory signals

We propose apractical, feature-level and score-level fusion approach by combining acoustic and estimated articulatory information for both text independent and text dependent speaker verification. From a practical point of view, we study how to improve speaker verification performance by combining dynamic articulatory information with the conventional acoustic features. On text independent speaker verification, we find that concatenating articulatory features obtained from measured speech production data with conventional Mel-frequency cepstral coefficients (MFCCs) improves the performance dramatically. However, since directly measuring articulatory data is not feasible in many real world applications, we also experiment with estimated articulatory features obtained through acoustic-to-articulatory inversion. We explore both feature level and score level fusion methods and find that the overall system performance is significantly enhanced even with estimated articulatory features. Such a performance boost could be due to the inter-speaker variation information embedded in the estimated articulatory features. Since the dynamics of articulation contain important information, we included inverted articulatory trajectories in text dependent speaker verification. We demonstrate that the articulatory constraints introduced by inverted articulatory features help to reject wrong password trials and improve the performance after score level fusion. We evaluate the proposed methods on the X-ray Microbeam database and the RSR 2015 database, respectively, for the aforementioned two tasks. Experimental results show that we achieve more than 15% relative equal error rate reduction for both speaker verification tasks. (C) 2015 Elsevier Ltd. All rights reserved.

Flower-like porous cobalt(II) monoxide nanostructures as anode material for Li-ion batteries

In the present study, a microwave-assisted, solution-based route has been employed to obtain porous CoO nano structures. Detailed characterization reveals that the flower-like nanostructures comprise petal-like sheets, each of which is made of an ordered, porous arrangement of crystallites of CoO measuring about 6 nm. TEM analysis shows that each ``petal'' is an oriented aggregate of CoO nanocrystals, such aggregation promoted by the hydroxyl moieties derived from the solution. The structure provides a large specific area as well as the porosity desirable in electrodes in Li-ion batteries. Electrochemical measurements carried out on electrodes made of nanostructured CoO show excellent Li ion-storing capability. A specific capacitance of 779 mAh g(-1) has been measured at a specific current of 100 mA g(-1). Measurements show also excellent cyclability and coulombic efficiency. Impedance spectroscopy provides evidence for charge transfer occurring in the porous networks. (C) 2015 Elsevier B.V. All rights reserved.

Dynamos driven by weak thermal convection and heterogeneous outer boundary heat flux

We use numerical dynamo models with heterogeneous core-mantle boundary (CMB) heat flux to show that lower mantle lateral thermal variability may help support a dynamo under weak thermal convection. In our reference models with homogeneous CMB heat flux, convection is either marginally supercritical or absent, always below the threshold for dynamo onset. We find that lateral CMB heat flux variations organize the flow in the core into patterns that favour the growth of an early magnetic field. Heat flux patterns symmetric about the equator produce non-reversing magnetic fields, whereas anti-symmetric patterns produce polarity reversals. Our results may explain the existence of the geodynamo prior to inner core nucleation under a tight energy budget. Furthermore, in order to sustain a strong geomagnetic field, the lower mantle thermal distribution was likely dominantly symmetric about the equator. (C) 2015 Elsevier B.V. All rights reserved.

A coupled discriminative dictionary and transformation learning approach with applications to cross domain matching

Cross domain and cross-modal matching has many applications in the field of computer vision and pattern recognition. A few examples are heterogeneous face recognition, cross view action recognition, etc. This is a very challenging task since the data in two domains can differ significantly. In this work, we propose a coupled dictionary and transformation learning approach that models the relationship between the data in both domains. The approach learns a pair of transformation matrices that map the data in the two domains in such a manner that they share common sparse representations with respect to their own dictionaries in the transformed space. The dictionaries for the two domains are learnt in a coupled manner with an additional discriminative term to ensure improved recognition performance. The dictionaries and the transformation matrices are jointly updated in an iterative manner. The applicability of the proposed approach is illustrated by evaluating its performance on different challenging tasks: face recognition across pose, illumination and resolution, heterogeneous face recognition and cross view action recognition. Extensive experiments on five datasets namely, CMU-PIE, Multi-PIE, ChokePoint, HFB and IXMAS datasets and comparisons with several state-of-the-art approaches show the effectiveness of the proposed approach. (C) 2015 Elsevier B.V. All rights reserved.

Doping dependence of fluctuation diamagnetism in high T-c superconductors

Using a recently proposed Ginzburg-Landau-like lattice free energy functional due to Banerjee et al. (2011) we calculate the fluctuation diamagnetism of high -T-c superconductors as a function of doping, magnetic field and temperature. We analyse the pairing fluctuations above the superconducting transition temperature in the cuprates, ranging from the strong phase fluctuation dominated underdoped limit to the more conventional amplitude fluctuation dominated overdoped regime. We show that a model where the pairing scale increases and the superfluid density decreases with underdoping produces features of the observed magnetization in the pseudogap region, in good qualitative and reasonable quantitative agreement with the experimental data. In particular, we explicitly show that even when the pseudogap has a pairing origin the magnetization actually tracks the superconducting dome instead of the pseudogap temperature, as seen in experiment. We discuss the doping dependence of the `onset' temperature for fluctuation diamagnetism and comment on the role of vortex core -energy jn our model. (C) 2015 Elsevier Inc. All rights reserved.

A coupled discriminative dictionary and transformation learning approach with applications to cross domain matching

Cross domain and cross-modal matching has many applications in the field of computer vision and pattern recognition. A few examples are heterogeneous face recognition, cross view action recognition, etc. This is a very challenging task since the data in two domains can differ significantly. In this work, we propose a coupled dictionary and transformation learning approach that models the relationship between the data in both domains. The approach learns a pair of transformation matrices that map the data in the two domains in such a manner that they share common sparse representations with respect to their own dictionaries in the transformed space. The dictionaries for the two domains are learnt in a coupled manner with an additional discriminative term to ensure improved recognition performance. The dictionaries and the transformation matrices are jointly updated in an iterative manner. The applicability of the proposed approach is illustrated by evaluating its performance on different challenging tasks: face recognition across pose, illumination and resolution, heterogeneous face recognition and cross view action recognition. Extensive experiments on five datasets namely, CMU-PIE, Multi-PIE, ChokePoint, HFB and IXMAS datasets and comparisons with several state-of-the-art approaches show the effectiveness of the proposed approach. (C) 2015 Elsevier B.V. All rights reserved.

Efficient simulation and rendering of realistic motion of one-dimensional flexible objects

In gross motion of flexible one-dimensional (1D) objects such as cables, ropes, chains, ribbons and hair, the assumption of constant length is realistic and reasonable. The motion of the object also appears more natural if the motion or disturbance given at one end attenuates along the length of the object. In an earlier work, variational calculus was used to derive natural and length-preserving transformation of planar and spatial curves and implemented for flexible 1D objects discretized with a large number of straight segments. This paper proposes a novel idea to reduce computational effort and enable real-time and realistic simulation of the motion of flexible 1D objects. The key idea is to represent the flexible 1D object as a spline and move the underlying control polygon with much smaller number of segments. To preserve the length of the curve to within a prescribed tolerance as the control polygon is moved, the control polygon is adaptively modified by subdivision and merging. New theoretical results relating the length of the curve and the angle between the adjacent segments of the control polygon are derived for quadratic and cubic splines. Depending on the prescribed tolerance on length error, the theoretical results are used to obtain threshold angles for subdivision and merging. Simulation results for arbitrarily chosen planar and spatial curves whose one end is subjected to generic input motions are provided to illustrate the approach. (C) 2016 Elsevier Ltd. All rights reserved.

The descriptive epidemiology of congenital and acquired cryptorchidism in a UK infant cohort.

INTRODUCTION: Recent studies in other European countries suggest that the prevalence of congenital cryptorchidism continues to increase. This study aimed to explore the prevalence and natural history of congenital cryptorchidism in a UK centre. METHODS: Between October 2001 and July 2008, 784 male infants were born in the prospective Cambridge Baby Growth Study. 742 infants were examined by trained research nurses at birth; testicular position was assessed using standard techniques. Follow-up assessments were completed at ages 3, 12, 18 and 24 months in 615, 462, 393 and 326 infants, respectively. RESULTS: The prevalence of cryptorchidism at birth was 5.9% (95% CI 4.4% to 7.9%). Congenital cryptorchidism was associated with earlier gestational age (p<0.001), lower birth weight (p<0.001), birth length (p<0.001) and shorter penile length at birth (p<0.0001) compared with other infants, but normal size after age 3 months. The prevalence of cryptorchidism declined to 2.4% at 3 months, but unexpectedly rose again to 6.7% at 12 months as a result of new cases. The cumulative incidence of "acquired cryptorchidism" by age 24 months was 7.0% and these cases had shorter penile length during infancy than other infants (p = 0.003). CONCLUSIONS: The prevalence of congenital cryptorchidism was higher than earlier estimates in UK populations. Furthermore, this study for the first time describes acquired cryptorchidism or "ascending testis" as a common entity in male infants, which is possibly associated with reduced early postnatal androgen activity.

Viscosity, Surface Tension, and Atomization of Water-Methanol and Diesel Emulsions

This article is the result of experimental studies of the rheologv, viscosities, surface tensions, and atomization of water-methanol and diesel emulsions. The Span 80 and Tween 60 are employed to make three emulsifying agents, Y01, Y02, and Y03, with viscosity of 1.32-1.5 Pa s and HLB values of 5.36, 4.83, and 4.51, respectively. In the water-in-oil emulsions, the aqueous phase is between 10% and 50%; the agent concentration added is 0.8-8.0%. The viscosity of the emulsions is 0.003-0.02 Pa s, and the surface tens ion is 0.04-0.1 N/m. The types and concentrations of agents significantly influence the viscosity of the emulsions, and the higher concentration of the aqueous phase (<50%) in creases the viscosities of the emulsions, especially for higher agent concentration. Interfacial membrane and HLB values of the agents can explain all these phenomena. Higher aqueous phase concentration and agent viscosity results in larger Sauter mean diameter.

Biomasa y nutrientes de arboles de sombra temporal y permanente en sistemas agroforestales con Coffea arabiga L de cinco años en el Pacifico de Nicaragua

Chavarria, E; Hernández, J. 2,006. Biomasa y nutrientes de árboles de sombra temporal y permanente en sistemas agroforestales con Coffea arabiga L de 5 años en el pacífico de Nicaragua. La presente investigación se realizó en sistemas agroforestales con café (Coffea arábiga L.) en el Municipio de Masatepe, Nicaragua, determinando el aporte de biomasa y los contenidos de N, P, K, Ca y Mg. de la sombra temporal y permanente. Se evaluaron dos factores de estudio en un diseño de bloques completamente al azar con arreglo de parcelas subdivididas: A) Tipo de sombra: temporal estableciéndose de forma homogénea y mixtas, especies de leguminosas más no leguminosas para sombra de café como Cajanus cajan y Ricinus communis y en sombra permanente, especies de árboles leguminosas y/o maderables (Inga laurina, Simarouba glauca, Samanea saman, Tabebuia rosea) y una parcela de café a pleno sol, distribuidas en parcelas grandes; B) Los niveles de insumos: Convencional Intensivo (CI) y Convencional Extensivo (CE), Orgánico Intensivo (OI) y Orgánico Extensivo (OE); relativos a aportes de nutrientes, manejo de enfermedades, malezas e insectos dañinos. La biomasa de sombra temporal se cuantificó en 2,002 por podas y 2,003 por eliminación de la misma. También se cuantificó la biomasa en la sombra permanente por podas en 2,004 y de raleo 2,005. La biomasa total por especie y tratamientos en sombra temporal y permanente, se obtuvieron a partir de los componentes hojas, tallos menores a 2 cm, tallos mayores de 2 cm de diámetro y tronco. Se tomó una muestra de biomasa fresca por tratamiento, se secó al horno a temperaturas de 65 ºC, para obtener el contenido de materia seca. A este mismo material, se procedió a la determinación de las concentraciones de los elementos minerales anteriormente mencionados. Los resultados obtenidos mostraron que la especie de sombra temporal no leguminosa Higuera (Ricinus communis) presentó el mayor aporte de materia seca con 4,356 kg ha-1 en dos años (2,002 + 2,003), representando también los mayores contenidos de N, P, K, Ca y Mg con 82, 28, 165, 68 y 57 kg ha-1 respectivamente. Respecto a las especies de sombra permanente, sometidas al manejo de poda el nivel de sombra Il+Sg produce los mayores aportes de MS con 5,695.66 kg ha-1 a-1 de los cuales el 39 % se recicla en el sistema, este mismo tipo de sombra aporta al sistema los mayores contenidos de N, P, K, Ca y Mg con 64, 55, 55, 66 y 36 % respectivamente. En el manejo de raleo el tipo de sombra que produjo mayor cantidad de MS es Sg+Tr con 9,096.89 kg ha-1 a-1 aportando al sistema el 45 %, este mismo tipo de sombra aporta al sistema las mayores cantidades de N, P, K, Ca y Mg con 67, 54, 70, 80 y 44 % respectivamente. Los porcentaje restante de materia seca y nutrientes tanto en poda y raleo correspondiente a tallos mayores de 2 cm de diámetro, es extraído del sistema como leña y postes respectivamente.