bluuebunny/crossref_metadata_2025 huggingface dataset:
M2 muscarinic receptor activation regulates schwann cell differentiation and myelin organization
Authors: Uggenti Carolina , De Stefano M. Egle , Costantino Michele , Loreti Simona , Pisano Annalinda , Avallone Bice , Talora Claudio , Magnaghi Valerio , Tata Ada Maria
Published: December 2013

Glial cells express acetylcholine receptors. In particular, rat Schwann cells express different muscarinic receptor subtypes, the most abundant of which is the M2 subtype. M2 receptor activation causes a reversible arrest of the cell cycle. This negative effect on Schwann cell proliferation suggests that these cells may possibly progress into a differentiating program. In this study we analyzed the in vitro modulation, by the M2 agonist arecaidine, of transcription factors and specific signaling pathways involved in Schwann cell differentiation. The arecaidine‐induced M2 receptor activation significantly upregulates transcription factors involved in the promyelinating phase (e.g., Sox10 and Krox20) and downregulates proteins involved in the maintenance of the undifferentiated state (e.g., c‐jun, Notch‐1, and Jagged‐1). Furthermore, arecaidine stimulation significantly increases the expression of myelin proteins, which is accompanied by evident changes in cell morphology, as indicated by electron microscopy analysis, and by substantial cellular re‐distribution of actin and cell adhesion molecules. Moreover, ultrastructural and morphometric analyses on sciatic nerves of M2/M4 knockout mice show numerous degenerating axons and clear alterations in myelin organization compared with wild‐type mice. Therefore, our data demonstrate that acetylcholine mediates axon‐glia cross talk, favoring Schwann cell progression into a differentiated myelinating phenotype and contributing to compact myelin organization. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 74: 676–691, 2014
Expression of actin‐binding proteins and requirement for actin‐depolymerizing factor in chick neural crest cells
Authors: Vermillion Katie L. , Lidberg Kevin A. , Gammill Laura S.
Published: December 2013

Background: Neural crest cells are multipotent cells that migrate extensively throughout vertebrate embryos to form diverse lineages. Cell migration requires polarized, organized actin networks that provide the driving force for motility. Actin‐binding proteins that regulate neural crest cell migration are just beginning to be defined. Results: We recently identified a number of actin‐associated factors through proteomic profiling of methylated proteins in migratory neural crest cells. Here, we report the previously undocumented expression pattern of three of these proteins in chick early neural crest development: doublecortin (DCX), tropomyosin‐1 (TPM‐1), and actin depolymerizing factor (ADF). All three genes are expressed with varying degrees of specificity and intensity in premigratory and migratory neural crest cells, and their resulting proteins exhibit distinct subcellular localization in migratory neural crest cells. Morpholino knock down of ADF reveals it is required for Sox10 gene expression, but minimally important during neural crest migration. Conclusions: Neural crest cells express DCX, TPM‐1, and ADF. ADF is necessary during neural crest specification, but largely dispensable for migration. Developmental Dynamics 243:731–739, 2014. © 2013 Wiley Periodicals, Inc.
Essential role for the SLK protein kinase in embryogenesis and placental tissue development
Authors: Al‐Zahrani Khalid N. , Sekhon Prabhjot , Tessier Daniel R. , Yockell‐Lelievre Julien , Pryce Benjamin R. , Baron Kyla D. , Howe Grant A. , Sriram Roshan K. , Daniel Kate , Mckay Marlene , Lo Vivian , Quizi Jennifer , Addison Christina L. , Gruslin Andrée , Sabourin Luc A.
Published: December 2013

Background: Over the past decade, the Ste20‐like kinase SLK, has been implicated in several signaling processes. SLK repression has been shown to impair cell cycle kinetics and inhibit FAK‐mediated cell migration. Here, using a gene trapped allele, we have generated mice expressing a truncated form of the SLK kinase. Results: Our results show that an SLK‐LacZ fusion protein is expressed in embryonic stem cells and in embryos throughout development. We find that the SLK‐LacZ fusion protein is less efficient at phosphorylating substrates resulting in reduced cell proliferation within the embryos and angiogenic defects in the placentae of the homozygous mutant animals at embryonic day (E) 12.5. This results in marked developmental defects and apoptotic lesions in the embryos by E14.5. Conclusions: Homozygotes expressing the SLK‐LacZ fusion protein present with an embryonic lethal phenotype occurring between E12.5 and E14.5. Overall, we demonstrate a requirement for SLK kinase activity in the developing embryo and placenta. Developmental Dynamics 243:640–651, 2014. © 2013 Wiley Periodicals, Inc.
[PMo12O40]3–‐Induced Perhydroxycucurbit[5]uril‐Based Porous Supramolecular Assemblies
Authors: Han Bao‐Xia , Wang Chuan‐Zeng , Zhao Yi , Chen Kai , Xiao Xin , Zhu Qian‐Jiang , Xue Sai‐Feng , Zhang Yun‐Qian , Tao Zhu
Published: December 2013

We prepared two new types of (HO)10Q[5]‐based supramolecular assemblies by using the [PMo12O40]3– anion as a structure inducer. Single‐crystal X‐ray diffraction analysis revealed that these two types of (HO)10Q[5]/[PMo12O40]3– hydrides were constructed from (HO)10Q[5]/[PMo12O40]3–‐based 2D networks in which [PMo12O40]3– plays a key rule in attracting (HO)10Q[5] molecules through (1) classical hydrogen bonding of the functionalized hydroxy groups on the back of the (HO)10Q[5] molecules, (2) unusual hydrogen bonding of the methylene groups on the back of the (HO)10Q[5] molecules, and (3) interaction between electron‐deficient carbon sites of the carbonyl groups of the (HO)10Q[5] molecules with electron‐rich oxygen sites of the Mo–O groups from the [PMo12O40]3– anions. An additional electrostatic interaction could exist in K+‐coordinated (HO)10Q[5] complexes.
Chiral Optical Properties of Phenyloxazoline Derivatives that Appear Only in the Solid State
Authors: Hirayama Masato , Kobayashi Yuhei , Tanaka Yuki , Sato Tomohiro , Harada Takunori , Tajima Nobuo , Kuroda Reiko , Fujiki Michiya , Imai Yoshitane
Published: December 2013

Unlike in the solution state, the circularly polarized luminescence (CPL) of the chiral oxazoline compound 4‐(4‐isopropyl‐4,5‐dihydrooxazol‐2‐yl)benzonitrile, having one oxazoline unit, was observed in the solid state. On the other hand, although the CPL of the chiral oxazoline compound 1,4‐bis(4‐isopropyl‐4,5‐dihydrooxazol‐2‐yl)benzene, having two oxazoline units, was not observed, its circular dichroism (CD) property changed significantly according to the state (i.e., solution or solid state).
1,3‐Dinitro Alkanes: An Emerging Class of Bidentate Compounds
Authors: Ballini Roberto , Gabrielli Serena , Palmieri Alessandro
Published: December 2013

1,3‐Dinitro alkanes are an emerging class of nitro alkanes that act as bidentate nucleophilic species suited to undergo a variety of reactions with an array of electrophiles. The goal of this microreview is to demonstrate the synthetic potential of these nitro derivatives, reporting both (i) recent procedures for the convenient synthesis (symmetric and asymmetric) of 1,3‐dinitro alkanes, and (ii) recent uses of these compounds as strategic starting materials for the preparation of a variety of important fine chemicals.
Divergent Reactivity of Alkyl Aryl Sulfones with Bases: Selective Functionalization of ortho‐Aryl and α‐Alkyl Units Enabled by a Unique Carbanion Transmetalation
Authors: Řehová Lucie , Císařová Ivana , Jahn Ullrich
Published: December 2013

The electron‐accepting sulfonyl group exhibits a strong acidifying influence on neighboring α‐H atoms. The Julia and related olefinations are based on this effect. Here a surprising reversal in the metalation selectivity of branched alkyl aryl sulfones is described. Such sulfones were found to initially undergo directed ortho‐metalation with good regioselectivity, despite having a more acidic α‐H atom. The structure of the alkyl unit profoundly, but predictably, influences the regioselectivity of the attack of the base. In β‐ and γ‐branched ortho‐(alkylsulfonyl)aryllithiums a transmetalation to the α‐carbanion proceeds only upon warming. Correspondingly generated ortho‐ or α‐carbanions were then selectively applied thus permitting access to synthetically interesting compound classes.
Nonparametric Quantile Regression‐Based Classifiers for Bankruptcy Forecasting
Authors: Lorca Pedro , Landajo Manuel , Andrés Javier De
Published: December 2013

An improved classification device for bankruptcy forecasting is proposed. The proposed approach relies on mainstream classifiers whose inputs are obtained from a so‐called multinorm analysis, instead of traditional indicators such as the ROA ratio and other accounting ratios. A battery of industry norms (computed by using nonparametric quantile regressions) is obtained, and the deviations of each firm from this multinorm system are used as inputs for the classifiers. The approach is applied to predict bankruptcy on a representative sample of Spanish manufacturing firms. Results indicate that our proposal may significantly enhance predictive accuracy, both in linear and nonlinear classifiers. Copyright © 2013 John Wiley & Sons, Ltd.
Sensory evaluation and consumer acceptance of naturally and lactic acid bacteria‐fermented pastes of soybeans and soybean–maize blends
Authors: Ng'ong'ola‐Manani Tinna A. , Mwangwela Agnes M. , Schüller Reidar B. , Østlie Hilde M. , Wicklund Trude
Published: December 2013

Fermented pastes of soybeans and soybean–maize blends were evaluated to determine sensory properties driving consumer liking. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and lactic acid bacteria fermented (LFP). Lactic acid bacteria fermentation was achieved through backslopping using a fermented cereal gruel, thobwa. Ten trained panelists evaluated intensities of 34 descriptors, of which 27 were significantly different (P < 0.05). The LFP were strong in brown color, sourness, umami, roasted soybean‐ and maize‐associated aromas, and sogginess while NFP had high intensities of yellow color, pH, raw soybean, and rancid odors, fried egg, and fermented aromas and softness. Although there was consumer (n = 150) heterogeneity in preference, external preference mapping showed that most consumers preferred NFP. Drivers of liking of NFP samples were softness, pH, fermented aroma, sweetness, fried egg aroma, fried egg‐like appearance, raw soybean, and rancid odors. Optimization of the desirable properties of the pastes would increase utilization and acceptance of fermented soybeans.
Shifting Paradigms on the Role of Connexin43 in the Skeletal Response to Mechanical Load
Authors: Lloyd Shane A , Loiselle Alayna E , Zhang Yue , Donahue Henry J
Published: December 2013

Gap junctions (GJs) are membrane-spanning channels that allow for the movement of small molecules across cell membranes. Connexin43 (Cx43) is the predominant GJ protein in bone. In vitro studies suggest that gap junctional intercellular communication (GJIC) sensitizes bone cells to mechanical signals. Additionally, mechanical signals detected by osteocytes are communicated to osteoblasts via GJIC, and osteocytic Cx43 hemichannels release anabolic factors, such as PGE2 and ATP, in response to mechanical load. These findings and others have led to near consensus among researchers in the field that GJIC, hemichannels or connexins facilitate the anabolic response of bone to mechanical load and, in their absence, bone would be less sensitive to load. However, recent in vivo evidence suggests the opposite is true. Studies from our laboratory and others demonstrate that Cx43-deficient mice have an increased anabolic response to mechanical load and are protected against the catabolic effects of mechanical unloading. These developments suggest a paradigm shift in our understanding of connexins, GJIC, and mechanotransduction in bone. That is, inhibiting bone cell Cx43 expression or GJIC has a beneficial effect on bone's response to its mechanical environment, preserving bone during unloading and enhancing its formation during loading. Here, we review literature in support of this hypothesis and suggest a mechanism by which Cx43, through interaction with WNT/β-catenin signaling, moderates both arms of bone remodeling. © 2014 American Society for Bone and Mineral Research.
Simultaneous MRI of lung structure and perfusion in a single breathhold
Authors: Bell Laura C. , Johnson Kevin M. , Fain Sean B. , Wentland Andrew , Drees Randi , Johnson Rebecca A. , Bauman Grzegorz , Francois Christopher J. , Nagle Scott K.
Published: December 2013

Purpose

To develop and demonstrate a breathheld 3D radial ultrashort echo time (UTE) acquisition to visualize co‐registered lung perfusion and vascular structure.

Materials and Methods

Nine healthy dogs were scanned twice at 3 Tesla (T). Contrast‐enhanced pulmonary perfusion scans were acquired with a temporally interleaved three‐dimensional (3D) radial UTE (TE = 0.08 ms) sequence in a breathhold (1 s time frames over a 33 s breathhold). The 3D breathheld volume was reconstructed into time‐resolved perfusion datasets, and a composite vascular structure dataset. For structural comparison, a 5 min respiratory‐gated 3D radial UTE scan was acquired. Data were analyzed by quantitative metrics and radiologist scoring.

Results

Appropriate time‐course of contrast was seen in all subjects. Right ventricle to aorta transit times were 7.4 ± 2.0 s. Relative lung enhancement was a factor of 8.4 ± 1.5. Radiologist scoring showed similarly excellent visualization of the pulmonary arteries to the subsegmental level in breathheld (94% of cases) and respiratory‐gated (100% of cases) acquisitions (P = 0.33) despite the aggressive under sampling in the breathheld scan. Similarly, differentiation of lung tissue and airways was achieved by both acquisition methods.

Conclusion

A time‐resolved 3D radial UTE sequence for simultaneous imaging of pulmonary perfusion and co‐registered vascular structure is feasible. J. Magn. Reson. Imaging 2015;41:52–59. © 2013 Wiley Periodicals, Inc.
Dissipative plasmon‐solitons in multilayer graphene
Authors: Smirnova Daria A. , Shadrivov Ilya V. , Smirnov Alexander I. , Kivshar Yuri S.
Published: December 2013

Nonlinear properties of a multi‐layer stack of graphene sheets are studied. It is predicted that such a structure may support dissipative plasmon‐solitons generated and supported by an external laser radiation. Novel nonlinear equations describing spatial dynamics of the nonlinear plasmons driven by a plane wave in the Otto configuration are derived and the existence of single and multi‐hump dissipative solitons in the graphene structure is predicted.
Completeness of intermediate logics with doubly negated axioms
Authors: Ardeshir Mohammad , Mojtahedi S. Mojtaba
Published: December 2013

Let denote a first‐order logic in a language that contains infinitely many constant symbols and also containing intuitionistic logic . By , we mean the associated logic axiomatized by the double negation of the universal closure of the axioms of plus . We shall show that if is strongly complete for a class of Kripke models , then is strongly complete for the class of Kripke models that are ultimately in .
The Role of Imagination and Brand Personification in Brand Relationships
Authors: Huang Hazel H. , Mitchell Vincent‐Wayne
Published: December 2013

Brand relationships have traditionally been theorized as simulating interpersonal relationships, which are reflected in self‐identity or self‐expansion theory. However, such a perspective often ignores or overlooks conceptual differences between true interpersonal relationships and parasocial brand relationships. Considering the characteristics of parasocial relationships, the present study explored the role of imagination and brand personification in the formation of brand relationships. A total of 468 subjects evaluated their favorite brands in a 2 (high vs. low product involvement) × 2 (utilitarian vs. symbolic products) factorial design. The results provided an alternative explanation of brand relationship formation: Imagination may play a greater role in brand relationships than traditionally conceived in self‐expansion theory, and brand personification may moderate the effect of self‐expansion theory. The implication of the research is that encouragement of consumers’ imaginative ability is one route to strengthening consumer–brand relationships.
A Name You Can Trust? Personification Effects Are Influenced by Beliefs About Company Values
Authors: Eskine Kendall J. , Locander William H.
Published: December 2013

Are consumers more likely to trust a product when it is branded with a human name rather than a nonhuman name? While the extant literature on brand personification reveals a positivity bias for personified products, other research suggests that many contemporary consumers harbor underlying feelings of mistrust toward companies more generally. The present research was the first empirical research to date to investigate the moderating role of consumers’ beliefs toward company values on brand trust judgments for human‐named and nonhuman‐named products. The results showed that although consumers significantly trusted nonhuman‐named products over human‐ named products (Studies 1a and 1b), this pattern only occurred for those who generally mistrusted companies (Study 2). These novel findings significantly shed light on the dynamics of brand personification by emphasizing the crucial role of individual differences in consumer judgment.
She Was Fine When She Left Here: Polysemy, Patriarchy, and Personification in Brand Titanic's Birthplace
Authors: Brown Stephen
Published: December 2013

Personification, according to MacKay, is the prototypical metaphor we live by. It is also inescapably gendered. This paper examines the gendering of one of the biggest brands on earth: the Titanic. In the century since the steamship's sinking, “she” has been enshrined in many female stereotypes from virtuous virgin to malevolent man‐eater. Although many might regard these representations as regressive and reprehensible, it is arguable that Titanic's polysemous pulchritude is what makes “her” an outstanding brand. For the inhabitants of the icon's “birthplace” at least.
Extremely rapid acclimation of Escherichia coli to high temperature over a few generations of a fed‐batch culture during slow warming
Authors: Guyot Stéphane , Pottier Laurence , Hartmann Alain , Ragon Mélanie , Hauck Tiburski Julia , Molin Paul , Ferret Eric , Gervais Patrick
Published: December 2013

This study aimed to demonstrate that adequate slow heating rate allows two strains of Escherichia coli rapid acclimation to higher temperature than upper growth and survival limits known to be strain‐dependent. A laboratory (K12‐TG1) and an environmental (DPD3084) strain of E. coli were subjected to rapid (few seconds) or slow warming (1°C 12 h−1) in order to (re)evaluate upper survival and growth limits. The slow warming was applied from the ancestral temperature 37°C to total cell death 46–54°C: about 30 generations were propagated. Upper survival and growth limits for rapid warming (46°C) were lower than for slow warming (46–54°C). The thermal limit of survival for slow warming was higher for DPD3084 (50–54°C). Further experiments conducted on DPD3084, showed that mechanisms involved in this type of thermotolerance were abolished by a following cooling step to 37°C, which allowed to imply reversible mechanisms as acclimation ones. Acquisition of acclimation mechanisms was related to physical properties of the plasma membrane but was not inhibited by unavoidable appearance of aggregated proteins. In conclusion, E.coli could be rapidly acclimated within few generations over thermal limits described in the literature. Such a study led us to propose that rapid acclimation may give supplementary time to the species to acquire a stable adaptation through a random mutation.
Assessing Different Possibilities for the Reuse of an Open‐pit Quarry Using the Choquet Integral
Authors: Bottero Marta , Ferretti Valentina , Pomarico Silvia
Published: December 2013

Multiple criteria decision analysis is a valuable and increasingly widely‐used tool to support decision‐making processes where there is a choice to be made between different options. This approach is particularly useful in the context of sustainability assessment where a complex and interconnected range of environmental, social and economic issues must be taken into consideration and where objectives are often competing.

It has been generally agreed that when dealing with sustainability issues, neither an economic reductionism nor an ecological one is possible. Because in general, economic sustainability has an ecological cost, and because ecological sustainability has an economic cost, an integrative framework such as multicriteria evaluation is needed for tackling sustainability issues properly. In this sense, the analysis of the possible interactions among the elements is of particular importance for assessing the sustainability of a certain transformation.

Within this context, a very important role is played by the ‘non‐additive measurement theory’, that makes use of the Choquet integral. This last represents the generalization of the weighted average method and provides a computational structure for aggregating information, taking into account interactivity between criteria.

The present paper proposes a multicriteria approach that is able to support decision makers in the choice of the best solution for the reuse of an abandoned open‐pit quarry. Five alternative options have been compared based on different indicators that have been aggregated using the Choquet integral in order to obtain the global sustainability level of each solution and to better highlight the trade‐offs between the aspects involved in the decision. Copyright © 2013 John Wiley & Sons, Ltd.
An analytic approach to a class of fractional differential‐difference equations of rational type via symbolic computation
Authors: Aslan İsmail
Published: December 2013

Fractional derivatives are powerful tools in solving the problems of science and engineering. In this paper, an analytical algorithm for solving fractional differential‐difference equations in the sense of Jumarie's modified Riemann–Liouville derivative has been described and demonstrated. The algorithm has been tested against time‐fractional differential‐difference equations of rational type via symbolic computation. Three examples are given to elucidate the solution procedure. Our analyses lead to closed form exact solutions in terms of hyperbolic, trigonometric, and rational functions, which might be subject to some adequate physical interpretations in the future. Copyright © 2013 John Wiley & Sons, Ltd.
Biophysical aspects of cyclodextrin interaction with paraoxon
Authors: Soni Sunil‐Datta , Bhonsle Jayendra B. , Garcia Gregory E.
Published: December 2013

Cyclodextrins are torus‐shaped polymers of glucose that can bind organophosphorous compounds such as nerve agents and pesticides. We demonstrate here that cyclodextrin can bind up to two paraoxon molecules with a Kav of 6775 M‐1. Molecular modeling shows that the paraoxon appears to bind in polar opposite orientation and have an average binding energy of −89 Kcals/mol. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Vehicle routing problems with regular objective functions on a path
Authors: Yu Wei , Liu Zhaohui
Published: December 2013

We investigate the problem of scheduling a fleet of vehicles to visit the customers located on a path to minimize some regular function of the visiting times of the customers. For the single‐vehicle problem, we prove that it is pseudopolynomially solvable for any minsum objective and polynomially solvable for any minmax objective. Also, we establish the NP‐hardness of minimizing the weighted number of tardy customers and the total weighted tardiness, and present polynomial algorithms for their special cases with a common due date. For the multivehicle problem involving n customers, we show that an optimal solution can be found by solving or O(n) single‐vehicle problems. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 61: 34–43, 2014
Conservative compact difference schemes for the coupled nonlinear schrödinger system
Authors: Hu Xiuling , Zhang Luming
Published: December 2013

In this article, some conservative compact difference schemes are explored for the strongly coupled nonlinear schrödinger system. After transforming the scheme into matrix form, we prove the existence and uniqueness, convergence and stability of the difference solutions for one nonlinear scheme in the norm by using some techniques of matrix theory. Numerical results show that one nonlinear scheme is the most efficient of all the compact schemes constructed here. It allows much larger time steps than the others. The second most efficient compact scheme is a linear one. We then give numerical simulations to two soliton interactions for the two most efficient compact schemes. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 749–772, 2014
Stability analysis for singularly perturbed differential equations by the upwind difference scheme
Authors: Li Zi Cai , Wei Yimin , Huang Hung Tsai , Chiang John Y.
Published: December 2013

For solving singularly perturbed differential equations (SPDE), the upwind difference scheme (UDS) and the fitted difference method are chosen. The local refinements of grids are adopted in singular layers with the minimal meshspacing , where h is the maximal meshspacing, and a very small parameter. The traditional condition number in 2‐norm is given by . For the infinitesimal in application, the huge Cond issues a dilemma regarding whether the numerical solutions by the UDS can be trusted. Although the UDS has been used for several decades, such a dilemma has not been clarified yet. The goal of this article is to clarify this dilemma. To this end, we solicit the effective condition number Cond_eff in Li et al. Numer Linear Algebra Appl 15 (2008), 575–690 Effective condition for Numerical Partial Different Equation, 2013, and develop a new actual condition number from the maximum principle. Both of them may offer much smaller bounds of the solution errors caused by perturbation, e.g., rounding, truncation, or discritization errors. We study the Dirichlet problems of SPDE by the UDS in a rectangle. When the Dirichlet boundary condition on the downwind side is homogeneous, we derive . When the entire Dirichlet boundary conditions are homogeneous, the extraordinary bound, , is achieved. Moreover, we derive the actual condition numbers as and for the homogeneous and the nonhomogeneous SPDE, respectively. Note that these bounds do not depend on ε; this is distinct from the traditional Cond. Based on the analysis of this article, the existing dilemma caused by Cond has been removed, to grant a good stability of the UDS for SPDE. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1595–1613, 2014
Constant pH molecular dynamics of proteins in explicit solvent with proton tautomerism
Authors: Goh Garrett B. , Hulbert Benjamin S. , Zhou Huiqing , Brooks Charles L.
Published: December 2013

pH is a ubiquitous regulator of biological activity, including protein‐folding, protein‐protein interactions, and enzymatic activity. Existing constant pH molecular dynamics (CPHMD) models that were developed to address questions related to the pH‐dependent properties of proteins are largely based on implicit solvent models. However, implicit solvent models are known to underestimate the desolvation energy of buried charged residues, increasing the error associated with predictions that involve internal ionizable residue that are important in processes like hydrogen transport and electron transfer. Furthermore, discrete water and ions cannot be modeled in implicit solvent, which are important in systems like membrane proteins and ion channels. We report on an explicit solvent constant pH molecular dynamics framework based on multi‐site λ‐dynamics (CPHMDMSλD). In the CPHMDMSλD framework, we performed seamless alchemical transitions between protonation and tautomeric states using multi‐site λ‐dynamics, and designed novel biasing potentials to ensure that the physical end‐states are predominantly sampled. We show that explicit solvent CPHMDMSλD simulations model realistic pH‐dependent properties of proteins such as the Hen‐Egg White Lysozyme (HEWL), binding domain of 2‐oxoglutarate dehydrogenase (BBL) and N‐terminal domain of ribosomal protein L9 (NTL9), and the pKa predictions are in excellent agreement with experimental values, with a RMSE ranging from 0.72 to 0.84 pKa units. With the recent development of the explicit solvent CPHMDMSλD framework for nucleic acids, accurate modeling of pH‐dependent properties of both major class of biomolecules—proteins and nucleic acids is now possible. Proteins 2014; 82:1319–1331. © 2013 Wiley Periodicals, Inc.
Promoting the assembly of carbon onions: An atomistic approach
Authors: Adhikari Bibek , Muthuraman Balaji , Mathioudakis Christos , Fyta Maria
Published: December 2013

Atomistic simulations at two levels, classical and quantum‐mechanical, are performed to probe the binding possibilities of the smallest multi‐shelled concentric fullerenes, known as “carbon onions”. We focus on the binding behavior of adjacent carbon onions and promote their binding through the addition of vacancies, as well as through doping with boron and nitrogen atoms. Molecular dynamics (MD) simulations are used to address the effect of different conditions of temperature and pressure on the binding of the onions and the thermal stability of the assembled structure. At a smaller scale, density‐functional theory (DFT) based calculations reveal the electronic structure of the coalesced carbon onions, their charge density and frontier orbitals. The effect of van der Waals forces is also evaluated using a tight‐binding scheme. Our main finding is that binding of adjacent carbon onions is promoted through the addition of vacancies and/or dopants on the outer surface of the carbon onions. The results are evaluated with respect to the relative distance between the adjacent carbon onions, the number of vacancies, and the amount or type of doping. We aim to optimize the conditions for assembling these nanoscale building blocks and understand their corresponding electronic properties in view of their potential in nano‐assembling novel functional nanomaterials.

(a) Two adjacent small carbon onions repel each other, while the carbon onions merge when tuning the external conditions and introducing vacancies on the structures as revealed from quantum mechanical (b) and classical simulations (c), respectively.
Lambda transitions in materials science: Recent advances in CALPHAD and first‐principles modelling
Authors: Körmann Fritz , Breidi Abed Al Hasan , Dudarev Sergei L. , Dupin Nathalie , Ghosh Gautam , Hickel Tilmann , Korzhavyi Pavel , Muñoz Jorge A. , Ohnuma Ikuo
Published: December 2013

This paper provides a comprehensive overview of state‐of‐the‐art computational techniques to thermodynamically model magnetic and chemical order–disorder transitions. Recent advances as well as limitations of various approaches to these so‐called lambda transitions are examined in detail, focussing on calphad models and first‐principles methods based on density functional theory (DFT). On the one hand empirical implementations –based on the Inden–Hillert–Jarl formalism –are investigated, including a detailed interpretation of the relevant parameters, physical limiting cases and potential extensions. In addition, Bragg–Williams‐based approaches as well as cluster‐variation methods of chemical order–disorder transitions are discussed. On the other hand, it is shown how magnetic contributions can be introduced based on various microscopic model Hamiltonians (Hubbard model, Heisenberg model and beyond) in combination with DFT‐computed parameters. As a result of the investigation we were able to indicate similarities between the treatment of chemical and magnetic degrees of freedom as well as the treatment within the calphad and DFT approaches. Potential synergy effects resulting from this overlap have been derived and alternative approaches have been suggested, in order to improve future thermodynamic modelling of lambda transitions.
Self‐assembly of poly(3‐hexylthiophene) nanowire networks by a mixed‐solvent approach for organic field‐effect transistors
Authors: Zhu Zongpeng , Wei Bin , Wang Jun
Published: December 2013

Organic field‐effect transistors (OFETs) based on interconnected nanowire networks of P3HT have been successfully fabricated by using a mixed‐solvent method. The nanowire network density can be tuned by controlling the anisole/chlorobenzene ratio of mixed solvents. The obtained field‐effect mobility, threshold voltage and the ratio of on‐state current and off‐state current (Ion/Ioff) was 0.0435 cm2/V s, –10 V and 1.75 × 104, respectively. The three‐dimensional and interconnected nanowire structure of the networks can enhance the charge transport in P3HT.

magnified image

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Remediation of a Former Dry Cleaner Using Nanoscale Zero Valent Iron
Authors: Jordan Michael , Shetty Nanjun , Zenker Matthew J. , Brownfield Christopher
Published: December 2013

Nanoscale zero valent iron (nZVI) was evaluated in a laboratory treatability study and subsequently injected as an interim measure to treat source area groundwater impacts beneath a former dry cleaner located in Chapel Hill, North Carolina (the site). Dry cleaning operations resulted in releases of tetrachloroethene (PCE) that impacted site soil at concentrations up to 2,700 mg/kg and shallow groundwater at concentrations up to 41 mg/L. To achieve a design loading rate of 0.001 kg of iron per kilogram of aquifer material, approximately 725 kg of NanoFe™ (PARS Environmental) was injected over a two‐week period into a saprolite and partially weather rock aquifer. Strong reducing conditions were established with oxidation–reduction potential (ORP) values below –728 mV. pH levels remained greater than 8 standard units for a period of 12 months. Injections resulted in near elimination of PCE within one month. cis‐1,2‐Dichloroethene accumulated at high concentrations (greater than 65 mg/L) for 12 months. MAROS software (Version 2.2; AFCEE, ) was used to calculate mass reduction of PCE and total ethenes at 96 percent and 58 percent, respectively, compared to baseline conditions. Detections of acetylene confirmed the presence of the beta‐elimination pathway. Detections of ethene confirmed complete dechlorination of PCE. Based on hydrogen gas generation, iron reactivity lasted 15 months. © 2013 Wiley Periodicals, Inc.
Distributional Patterns of Arsenic Concentrations in Contaminant Plumes Offer Clues to the Source of Arsenic in Groundwater at Landfills
Authors: Harte Philip T.
Published: December 2013

The distributional pattern of dissolved arsenic concentrations from landfill plumes can provide clues to the source of arsenic contamination. Under simple idealized conditions, arsenic concentrations along flow paths in aquifers proximal to a landfill will decrease under anthropogenic sources but potentially increase under in situ sources. This paper presents several conceptual distributional patterns of arsenic in groundwater based on the arsenic source under idealized conditions. An example of advanced subsurface mapping of dissolved arsenic with geophysical surveys, chemical monitoring, and redox fingerprinting is presented for a landfill site in New Hampshire with a complex flow pattern. Tools to assist in the mapping of arsenic in groundwater ultimately provide information on the source of contamination. Once an understanding of the arsenic contamination is achieved, appropriate remedial strategies can then be formulated. © 2013 Wiley Periodicals, Inc.*
A one‐to‐one programme for at‐risk readers delivered by older adult volunteers
Authors: Fives Allyn , Kearns Noreen , Devaney Carmel , Canavan John , Russell Dan , Lyons Rena , Eaton Patricia , O'Brien Aoife
Published: December 2013

This paper is based on a randomized controlled trial (RCT) evaluation of a reading programme delivered by older adult volunteers for at‐risk early readers. Wizards of Words (WoW) was targeted at socially disadvantaged children in first and second grade experiencing delays in reading but who were not eligible for formal literacy supports. The programme was effective for phonemic awareness, word recognition, phonic knowledge and children's self‐beliefs, but was not effective for reading comprehension, vocabulary, spelling or reading accuracy. The programme was most effective for those children starting with ‘below average’ reading levels and for boys. Programme intensity, school attendance and the child's experience of the programme all predicted response to intervention. Gains in phonemic awareness and phonic knowledge may be explained by the priority given in volunteer training and in programme delivery to the phonics component, and gains in word recognition may be explained by its close association with phonemic awareness and phonic knowledge, as hypothesized by the Simple View of Reading. The findings show that a reading programme delivered by older adult volunteers can have a significant impact on reading skills and self‐beliefs of at‐risk readers who are not eligible for other formal literacy supports.
Patterns of habitat use and selection by the capybara (Hydrochoerus hydrochaeris): a landscape‐scale analysis
Authors: Corriale María José , Herrera Emilio A.
Published: December 2013

Habitat selection analysis provides useful information on how animals become distributed in response to spatial heterogeneity. Here, we analyze the habitat use and selection of different water bodies (marsh, swamps and round shallow lakes) by capybaras (Hydrochoerus hydrochaeris) and their relation to environmental variables during contrasting climate‐hydrological seasons in the Esteros del Iberá (Corrientes, Argentina). We evaluated the intensity of use by capybaras through the total number of individuals (abundance) in each water body, the number and mean size of social groups, and the physical and vegetation characteristics of the environment. The capybaras used marsh and swamps according to availability in both seasons, while they used rounded shallow lakes less than their available would suggest in summer. The use intensity of different rounded shallow lakes estimated based on group size did not show significant differences. In contrast, significant differences were observed when evaluated by the number of individuals in each rounded shallow lake. Different intensity of use was closely associated with environmental and vegetation characteristics. The results show that habitat suitability for capybaras is associated with vegetation cover and “embalsados” in the low‐lying area rather than with the morphometry of the rounded shallow lakes. The pattern of habitat selection may depend on forage quality, water availability for thermoregulation and mating, and presence of shelter and resting sites. On the other hand, the present study shows how the size, shape and the abundance of different types of water bodies affect population abundance and density.
Design and Surface/Interfacial Properties of Asymmetric Triazine Carboxyl Betaine Surfactants
Authors: Jing Lishuai , Qiao Weihong , Luo Limei , Peng Huan
Published: December 2013

The design, synthesis and interfacial behaviors of six asymmetric carboxyl betaine surfactants (BCm−n, m, n = 8, 10, 12, or 14, m ≠ n) derived from s‐triazine, which were prepared from cyanuric chloride, aliphatic amines, N,N‐dimethylpropane‐1,3‐diamine, followed by the reaction with sodium chloroacetate, are reported. The structures were confirmed by MS, 1H NMR and FT‐IR. Compared with symmetric surfactants (BCn−n, n = 8, 10, 12, or 14) we previously synthesized, the asymmetric series show superior surface activity. The γCMC of surfactants BC10−8, BC12−8, BC14−8 and BC12−10 is all below 30 mN/m. The minimum alkane carbon number of these ten surfactants is determined to be between 10 and 14. The interfacial behaviors between the alkanes and the solutions of triazine carboxyl betaine surfactants show that surfactants with a total carbon number in hydrophobic chains between 16 and 22 exhibit the ability to reduce the interfacial tension to an ultra‐low value (10−3 mN/m). The surfactants with longer hydrocarbon chains display strong affinity to the alkanes with longer chains.
Wavelength-dispersive X-ray Fluorescence Spectrometric Determination of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in Komatiites
Authors: Viswanathan S. , Rao K. Surya Prakash , Mahabaleswar B.
Published: December 2013

Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral–line interferences, inter-element effects, speed, advantages, and limitations of the technique.

The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.
Landslide Hazard Zonation in and around Thodupuzha–Idukki–Munnar Road, Idukki District, Kerala: A Geospatial Approach
Authors: Abraham P. Biju , Shaji E.
Published: December 2013

Landslide hazard zonation in and around Thodupuzha – Idukki – Munnar road (TM Road) in Idukki district, Kerala, India has been carried out using geospatial techniques. Being a landslide prone area a hazard zonation is attempted using terrain fragility concept. Based on the traverse mapping, slide prone areas and palaeo-slides along the TM road were identified. Precambrian crystallines consisting of hornblende-biotite gneiss, biotite gneiss, granite gneiss, charnockite and pink granites form the main rock types. Factor maps of various terrain parameters such as slope, landuse, relative relief, drainage pattern, drainage density, landform, and surface material were prepared and their integration carried out on a GIS platform. Based on geospatial analyses, the study area (438 sq. km) is ranked into four classes of relative fragility viz. highly fragile (8.25 sq. km), fragile (41.25 sq. km), moderately fragile (232 sq. km) and stable (156.5 sq. km). The first two categories together form 11% of the area, the most hazardous regions, which require immediate mitigation measures for slope protection. The study forms a basis for evolving a strategy for the development of the entire TM road of Idukki district. The fragility concept used in this study is a fast and cost effective model for identifying landslide prone areas, especially in the Western Ghats.
Managed Aquifer Recharge (MAR) by the Construction of Sub-surface Dams in the Semi-arid Regions: A Case Study of the Kalangi River Basin, Andhra Pradesh
Authors: Raju N. Janardhana , Reddy T.V.K. , Muniratnam P. , Gossel Wolfgang , Wycisk Peter
Published: December 2013

Overuse of groundwater in coastal areas, due to high population and agricultural activity results in seawater intrusion into the coastal aquifer. This paper presents the control measures taken to manage aquifer recharge (MAR) and also to overcome the problem of seawater intrusion into the coastal aquifer along the Kalangi river, Nellore district of Andhra Pradesh, India having connectivity with Pulicat (saltwater) lake estuary. Due to overexploitation of groundwater and less rainfall in past years, adjacent seawater has started intruding in the Kalangi river sub-surface and deteriorating groundwater quality up to 11.6 km from the confluence of the river with Pulicat lake. To prevent this situtation, sub-surface dams were constructed in traditional manner using local earth material in three different places across the Kalangi river near Sullurpet town. The water storage capacities calculated after the sub-surface dams’ construction are 1.28 mcft at GK Engineering College, 6.23 mcft at Challamagudi and 3.143 mcft at Holy Cross School sites.

The Holy Cross School sub-surface dam is the first full scale dam-cum-check dam constructed to prevent salt water intrusion in the Kalangi river at Sullurpet, Nellore district, Andhra Pradesh. At the Kalangi river estuary portion (at the mouth of sea) a groyne was reconstructed over old groyne site with the introduction of clay bed and wooden sheet piles at down stream. Apart from prevention of sea water entry into Kalangi river sub-surface (during seasons) the groyne top level was raised to prevent mixing of high sea water tides with fresh water and ensuring additional storage of fresh water at upstream side. The reconstructed groyne was serving the purpose of obstructing the surface seawater entry in the Kalangi river and water quality has improved in the river as well as in the wells. After construction of sub-surface dam, as per the Simpson ratio classification, there is substantial improvement of water quality in the SHAR infiltration well situated near the Holy Cross School sub-surface dam.
Impact of Industrial Effluents on Groundwater around Pali City, Rajasthan Using Field and Satellite Data
Authors: Bhadra B. K. , Pathak Suparn , Sharma J. R.
Published: December 2013

Groundwater pollution due to industrial effluents from textile units around Pali city area is the major concern to the local villagers and the district administration. Indiscriminate discharge of these effluents in the past two decades caused severe damage to the agricultural land and groundwater resources within 3 km buffer zone of the Bandi river. Remote Sensing and GIS techniques are found to be better tools in assessing the damage in agricultural crops during 1997 and 2006 with the help of high resolution satellite images. Groundwater fluctuation trend with annual rainfall pattern during 1985 and 2005 indicate good recharge in the study area. Detailed analysis of groundwater quality parameters (TDS, Cl and SO4) and heavy metals (Cu, Pb, Zn, Fe, Cd and Cr) for 1997-98 indicates maximum concentration around Chatelao village and Dholera Jagir in the downstream direction of Bandi river. However, temporal analysis of groundwater samples collected in January, 2009 shows marginal decrease in concentration of TDS, Cl, SO4, Pb and Cu in both groundwater as well as river effluents. Slight improvement in water quality especially heavy metals in the last 12 years (1998-2009) may be attributed to the appropriate measures (treatment of wastewater and solid waste disposal) taken by the establishment of three Common Effluent Treatment Plants (CETP) in Pali city area. However, a few stringent actions may be taken to avoid direct discharge of the effluents into Bandi river.