bluuebunny/crossref_metadata_2025 huggingface dataset:
Copper(II)‐bis‐Histidine Coordination Structure in a Fibrillar Amyloid β‐Peptide Fragment and Model Complexes Revealed by Electron Spin Echo Envelope Modulation Spectroscopy
Authors: Hernández‐Guzmán Jessica , Sun Li , Mehta Anil K. , Dong Jijun , Lynn David G. , Warncke Kurt
Published: September 2013

Truncated and mutated amyloid‐β (Aβ) peptides are models for systematic study—in homogeneous preparations—of the molecular origins of metal ion effects on Aβ aggregation rates, types of aggregate structures formed, and cytotoxicity. The 3D geometry of bis‐histidine imidazole coordination of CuIIin fibrils of the nonapetide acetyl‐Aβ(13–21)H14A has been determined by powder14N electron spin echo envelope modulation (ESEEM) spectroscopy. The method of simulation of the anisotropic combination modulation is described and benchmarked for a CuII‐bis‐cis‐imidazole complex of known structure. The revealed bis‐ciscoordination mode, and the mutual orientation of the imidazole rings, for CuIIin Ac‐Aβ(13–21)H14A fibrils are consistent with the proposed β‐sheet structural model and pairwise peptide interaction with CuII, with an alternating [‐metal‐vacancy‐]npattern, along the N‐terminal edge. Metal coordination does not significantly distort the intra‐β‐strand peptide interactions, which provides a possible explanation for the acceleration of Ac‐Aβ(13–21)H14A fibrillization by CuII, through stabilization of the associated state and low‐reorganization integration of β‐strand peptide pair precursors.
The Multivalent Effect in Glycosidase Inhibition: Probing the Influence of Valency, Peripheral Ligand Structure, and Topology with Cyclodextrin‐Based Iminosugar Click Clusters
Authors: Decroocq Camille , Joosten Antoine , Sergent Raphaël , Mena Barragán Teresa , Ortiz Mellet Carmen , Compain Philippe
Published: September 2013

In view of recent reports of a strong multivalent effect in glycosidase inhibition, a library of β‐CD‐based multivalent iminosugars has been efficiently synthesized by way of CuI‐catalyzed azide–alkyne cycloaddition (CuAAC). In combination with the first application of isothermal titration calorimetry (ITC) experiments to the study of multivalent iminosugar–enzyme interactions, the inhibition properties of these click clusters were evaluated on a panel of glycosidases. The structural parameters that were varied include valency, peripheral ligand structure, and topology. The inhibition results obtained with the iminosugar clusters further highlight the importance of multivalency in the inhibition of α‐mannosidase. Generally, the evaluated multivalent iminosugars displayed comparable thermodynamic signatures of binding towards α‐mannosidase (Jack bean): that is, large negative enthalpies of complexation coupled with small entropies of either sign. In addition, the enthalpy–entropy compensation observed in all tested cases may be attributed to a common mechanism of dissociation for the enzyme–multivalent iminosugar interactions. The measured binding stoichiometries indicated that each iminosugar cluster interacts with no more than one protein molecule.
Fischer–Tropsch Synthesis Over Skeletal FeCe Catalysts Leached from Rapidly Quenched Ternary FeCeAl Alloys
Authors: Sun Bo , Lin Jun , Xu Ke , Pei Yan , Yan Shirun , Qiao Minghua , Zhang Xiaoxin , Zong Baoning
Published: September 2013

The new Ce‐promoted skeletal Fe catalysts with different Ce contents were prepared through alkali leaching of rapidly quenched ternary FeCeAl alloys and evaluated in the gas‐phase Fischer–Tropsch synthesis reaction. N2 physisorption and XRD analysis confirmed the function of Ce as a structural promoter. In the Fischer–Tropsch synthesis reaction, the incorporation of Ce markedly improved the activity and selectivity to C5+ hydrocarbons. Characterizations of the catalysts after Fischer–Tropsch synthesis confirmed the function of Ce as a chemical promoter. We also confirmed that the catalytic activity is associated with the concentrations of the surface polymeric and, to a lesser extent, atomic carbonaceous species and the C5+ selectivity correlated well with the surface concentration of Hägg carbide. We identified a linear relationship between the concentrations of the CeIII cations and Hägg carbide, which clearly substantiated the hypothesis that the chemical effect of Ce is mediated by the Fe0CeIII ensembles facilitating the formation of Hägg carbide.
Nucleation Kinetics and Growth Model of Penicillin Sulfoxide in Butyl Acetate
Authors: Jing D. , Wang J. , Zhang M. , Wang Y. , Xie C.
Published: September 2013

Nucleation kinetics and a growth model of penicillin sulfoxide in butyl acetate were studied. Nucleation parameters such as energy per unit volume, radius of critical nucleus, critical free energy barrier, and nucleation rate were evaluated. A laser method was selected to detect the first crystal in induction period studies. By means of scanning electron microscopy and surface entropy factor, the growth model of penicillin sulfoxide developed from butyl acetate could be determined.
Structure and Catalytic Performance of Mg‐SBA‐15‐Supported Nickel Catalysts for CO2 Reforming of Methane to Syngas
Authors: Zhang H. , Li M. , Xiao P. , Liu D. , Zou C. J.
Published: September 2013

A series of Mg‐modified SBA‐15 mesoporous silicas with different MgO contents were successfully synthesized by a simple one‐pot synthesis method and further impregnated with Ni. The Mg‐modified SBA‐15 materials and supported Ni catalysts were characterized by N2 physisorption (BET), X‐ray diffraction (XRD), temperature‐programmed desorption of CO2 (CO2‐TPD), temperature‐programmed H2 reduction (H2‐TPR), and temperature‐programmed hydrogenation (TPH) techniques and used for methane dry reforming with CO2. CO2‐TPD results proved that the addition of Mg increased the total amount of basic sites which was responsible for the enhanced catalytic activity over the Mg‐modified Ni catalyst. The excellent catalytic stability of Ni/8Mg‐SBA‐15 was ascribed to less coking and higher stability of the Ni particle size due to the introduction of Mg.
Oxygen Mass Transfer Rate in a Pressurized Lab‐Scale Stirred Bioreactor
Authors: Lopes M. , Mota M. , Belo I.
Published: September 2013

Oxygen mass transfer from air to the liquid phase in bioreactors with aerobic cultures has long been a serious impairment to the productivity of various bioprocesses. An increase of the oxygen mass transfer rate (OTR) can be the key to overcome oxygen limitation. The influence of higher air pressure on OTR was measured and a significantly enhanced OTR could be obtained. The oxygen volumetric mass transfer coefficient (kLa) was described by a function of the air pressure in a stirred lab‐scale pressurized bioreactor. The correlation obtained proved that kLa slightly decreased with higher air pressure, following a power function.
Synthesis and Characterization of Amorphous Nano‐Alumina Powders with High Surface Area for Biodiesel Production
Authors: Amini G. , Najafpour G. D. , Rabiee S. M. , Ghoreyshi A. A.
Published: September 2013

Nano‐alumina powders containing yttrium oxide were synthesized via the sol‐gel method using aluminum chloride hexahydrate as catalyst precursor. Fourier transform infrared analysis showed the presence of Al‐O and Al‐O‐Al bands in the powder structure and X‐ray diffraction spectra proved that the alumina was in the amorphous phase. The amorphous nano‐alumina powders were shown to be mesoporous with a high surface area, and both spherical and slit‐shaped particles were found in the calcined powder. A high percentage of conversion of oil to biodiesel was obtained in the transesterification reaction and the synthesized nano‐alumina powders could be easily regenerated for further use. The amorphous nano‐alumina powder can thus be recommended for use as active catalyst in the transesterification reaction for biodiesel production on the industrial scale.
High‐Pressure Generator of Singlet Oxygen
Authors: Jirásek V. , Čenský M. , Špalek O. , Kodymová J.
Published: September 2013

The generation of gaseous singlet oxygen by gas‐liquid reaction of chlorine with alkaline solution of hydrogen peroxide in spray form was studied experimentally on the originally designed device with a fast separation of reacted liquid from gas. The singlet oxygen yield, residual chlorine, and water vapor content in gas were measured under different experimental conditions of the centrifugal spray singlet oxygen generator (CSSOG) using nitrogen as a dilution gas. A characteristic feature of the CSSOG is a high utilization of the chemicals and production of singlet oxygen at a very high total pressure even near the atmospheric pressure. This generator developed originally for driving a chemical oxygen‐iodine laser (COIL) could be employed also as an efficient singlet oxygen source in material science, chemical synthesis, and others.
Drop Detachment from a Micro‐Engineered Membrane Surface in a Dynamic Membrane Emulsification Process
Authors: Holzapfel S. , Rondeau E. , Mühlich P. , Windhab E. J.
Published: September 2013

Drop size distribution is an important characteristic of emulsions, probably the most crucial one for their use in various applications. Here, a pilot‐scale apparatus with a cone‐shaped flow geometry is introduced. The plate contains a micro‐engineered membrane manufactured from silicon allowing for the production of emulsions with narrow drop size distributions. The process is characterized by producing model emulsions of the oil‐in‐water type under laminar rheometric flow conditions and by accessing the regime of drop detachment as a function of the wall shear stress applied, by means of high‐speed imaging in a separate flow cell. Furthermore, clear evidence is given of the crucial influence of the membrane wetting properties on the emulsification results, by comparing the performance of micro‐engineered membranes composed either of silicon, silicon nitride, or nickel, for pore diameters from 1 to 12 μm, in the flow cell.
A Standard Procedure for the Selection of Solvents for Natural Plant Extraction in the Early Stages of Process Development
Authors: Bergs D. , Merz J. , Delp A. , Joehnck M. , Martin G. , Schembecker G.
Published: September 2013

The standard procedure for the selection of solvents for natural plant extraction is a hybrid approach of solubility estimation and experimental investigations to reduce the time of solvent screening to a minimum. The focus is on the selection of a suitable solvent for natural product extraction in the early stages of process development when thermodynamic data are not yet available and solid‐liquid extraction is still an alternative to other techniques. The standard procedure is implemented in Microsoft® Excel™, provides the necessary information, creates experimental test plans, performs calculations and supports the user by structured descriptions to select the most desirable solvent for extraction. In this study, its application to the natural products rebaudioside A from Stevia rebaudiana Bertoni leaves, caffeine from guaraná seeds, and artemisinin from Artemisia annua leaves is demonstrated. The standard procedure predicted solvents that were found in the literature, plus solvents with even better extraction performance than the ones described in the literature.
The Catalytic Mechanism of Protein Phosphatase 5 Established by DFT Calculations
Authors: Ribeiro António J. M. , Alberto Marta E. , Ramos Maria J. , Fernandes Pedro A. , Russo Nino
Published: September 2013

In order to elucidate the catalytic mechanism of the Mn–Mn containing serine/threonine protein phosphatase 5 (PP5), we present a density functional theory study with a cluster model approach. According to our results, the reaction occurs through an in‐line concerted transition state with an energy of 15.8 kcal mol−1, and no intermediates are formed. The important role played by His304 and Asp274 as stabilizers of the leaving group has been shown, whereas the role played by the metal ions seems to be mostly electrostatic. The indispensable requirement of having a neutral active center has been demonstrated by testing different protonation states of the cluster model. We have shown also the importance of describing properly the electronic configuration of the Mn–Mn binuclear centers.
Enantioselective Bioaccumulation of Diniconazole in Tenebrio Molitor Larvae
Authors: Liu Chen , Tian LV Xiao , Zhu Wen Xue , Yang QU Hao , Gao Yong Xin , Guo Bao Yuan , Wang Hui Li
Published: September 2013

The enantioselective bioaccumulation of diniconazole in Tenebrio molitor Linne larva was investigated with liquid chromatography tandem mass spectrometry based on the ChiralcelOD‐3R[cellulose tri‐(3,5‐dimethylphenyl carbamate)] column. In this study we documented the effects of dietary supplementation with wheat bran contaminated by racemic diniconazole at two dose levels of 20 mg kg‐1 and 2 mg kg‐1 (dry weight) in Tenebrio molitor. The results showed that both doses of diniconazole were taken up by Tenebrio molitor rapidly in the first few days, the concentrations of R‐enantiomer and S‐enantiomer at high doses reached the highest level of 0.55 mg kg‐1 and 0.48 mg kg‐1, respectively, on the 1st d, and the concentrations of them obtained a maxima of 0.129 mg kg‐1 and 0.128 mg kg‐1 at low dose, respectively, on the 3rd d, which means that the concentration of diniconazole was proportional to the time of achieving the highest accumulated level. It afterwards attained equilibrium after a sharp decline at both 20 mg kg‐1 and 2 mg kg‐1 of diniconazole. The determination results from the feces of Tenebrio molitor demonstrated that the extraction recovery (ER) values of the high dose group were higher than that of the low dose group and the values were all above 1; therefore, it could be inferred that enantiomerization existed in Tenebrio molitor. Additionally, the biota accumulation factor was used to evaluate the bioaccumulation of diniconazole enantiomers, showing that the bioaccumulation of diniconazole in Tenebrio molitor was enantioselective with preferential accumulation of S‐enantiomer. Chirality 25:917–922, 2013. © 2013 Wiley Periodicals, Inc.
Iterative learning control for MIMO nonlinear systems with arbitrary relative degree and no states measurement
Authors: Bouakrif Farah
Published: September 2013

This article presents a state observer based iterative learning control to solve the trajectory tracking problem of a class of time‐varying Multi‐Input‐Multi‐Output nonlinear systems with arbitrary relative degree. For this purpose, an asymptotically stable observer is derived for the system under consideration. There after, this observer is integrated with the iterative learning controller by replacing the state in the control law with its estimation yielded by the state observer. Hence, the stability of the whole control (nonlinear system plus controller plus observer) is guaranteed. Simulation result on nonlinear system shows that the trajectory tracking error decreases through the iterations. © 2013 Wiley Periodicals, Inc. Complexity 19: 37–45, 2013
Topological structures of complex belief systems
Authors: Nescolarde‐Selva Josué-Antonio , Usó‐Doménech José-Luis
Published: September 2013

The concepts of substantive beliefs and derived beliefs are defined, a set of substantive beliefs S like open set and the neighborhood of an element substantive belief. A semantic operation of conjunction is defined with a structure of an Abelian group. Mathematical structures exist such as poset beliefs and join‐semilattttice beliefs. A metric space of beliefs and the distance of belief depending on the believer are defined. The concepts of closed and opened ball are defined. S′ is defined as subgroup of the metric space of beliefs Σ and S′ is a totally limited set. The term s is defined (substantive belief) in terms of closing of S′. It is deduced that Σ is paracompact due to Stone's Theorem. The pseudometric space of beliefs is defined to show how the metric of the nonbelieving subject has a topological space like a nonmaterial abstract ideal space formed in the mind of the believing subject, fulfilling the conditions of Kuratowski axioms of closure. To establish patterns of materialization of beliefs we are going to consider that these have defined mathematical structures. This will allow us to understand better cultural processes of text, architecture, norms, and education that are forms or the materialization of an ideology. This materialization is the conversion by means of certain mathematical correspondences, of an abstract set whose elements are beliefs or ideas, in an impure set whose elements are material or energetic. Text is a materialization of ideology. © 2013 Wiley Periodicals, Inc. Complexity 19: 46–62, 2013
Silicon nanowire growth on poly‐silicon‐on‐quartz substrates formed by aluminum‐induced crystallization
Authors: Kendrick Chito , Bomberger Cory , Dawley Natalie , Georgiev Julie , Shen Haoting , Redwing Joan M.
Published: September 2013

The vertical growth of Si nanowires on non‐monocrystalline substrates is of significant interest for photovoltaics and other energy harvesting applications. In this paper, we present results on using poly‐Si layers formed by aluminum‐induced crystallization (AIC) on fused quartz wafers as an alternative substrate for the vapor‐liquid‐solid (VLS) growth of vertical Si nanowires. Oxidation of the Al surface to Al2O3 before the a‐Si deposition was shown to be a key requirement in the formation of the poly‐Si template since it promotes the crystallization of the a‐Si into Si(111) which is required for vertical silicon nanowire growth. The effect of Al deposition technique (DC sputtering versus thermal evaporation) on a‐Si crystallization and Si nanowire growth was investigated. The use of Al thermal evaporation yielded AIC poly‐Si layers with the highest fraction of 〈111〉 grains as measured by orientation imaging microscopy (OIM) which enabled the growth of vertical Si nanowires. Cross‐sectional transmission electron microscopy analysis confirmed that the 〈111〉 Si nanowires grew epitaxially off of {111}poly‐Si grains in the AIC layer. This study demonstrates the potential of using AIC poly‐Si as a template layer for the vertical growth of silicon nanowires on amorphous substrates.
Development of auditory event‐related potentials in infants prenatally exposed to methadone
Authors: Paul Jonathan A. , Logan Beth A. , Krishnan Ramesh , Heller Nicole A. , Morrison Deborah G. , Pritham Ursula A. , Tisher Paul W. , Troese Marcia , Brown Mark S. , Hayes Marie J.
Published: September 2013

Developmental features of the P2 auditory ERP in a change detection paradigm were examined in infants prenatally exposed to methadone. Opiate dependent pregnant women maintained on methadone replacement therapy were recruited during pregnancy (N = 60). Current and historical alcohol and substance use, SES, and psychiatric status were assessed with a maternal interview during the third trimester. Medical records were used to collect information regarding maternal medications, monthly urinalysis, and breathalyzer to confirm comorbid drug and alcohol exposures. Between birth and 4 months infant ERP change detection performance was evaluated on one occasion with the oddball paradigm (.2 probability oddball) using pure‐tone stimuli (standard = 1 kHz and oddball = 2 kHz frequency) at midline electrode sites, Fz, Cz, Pz. Infant groups were examined in the following developmental windows: 4–15, 16–32, or 33–120 days PNA. Older groups showed increased P2 amplitude at Fz and effective change detection performance at P2 not seen in the newborn group. Developmental maturation of amplitude and stimulus discrimination for P2 has been reported in developing infants at all of the ages tested and data reported here in the older infants are consistent with typical development. However, it has been previously reported that the P2 amplitude difference is detectable in neonates; therefore, absence of a difference in P2 amplitude between stimuli in the 4–15 days group may represent impaired ERP performance by neonatal abstinence syndrome or prenatal methadone exposure. © 2013 Wiley Periodicals, Inc. Dev Psychobiol 56: 1119–1128, 2014.
Multistep manipulations of poly(methyl‐methacrylate) submicron particles using dielectrophoresis
Authors: Chuang Cheng‐Hsin , Huang Yao‐Wei
Published: September 2013

A microfluidic chip for multistep manipulations of PMMA submicron particles (PMMA‐SMPs) based on dielectrophoresis (DEP) has been developed that includes four main functions of focusing, guiding, trapping, and releasing the SMPs. The structure of the DEP chip consists of a top electrode made of indium tin oxide, a flow chamber formed by optically clear adhesive tape and bottom electrodes with different patterns for different purposes. The bottom electrodes can be divided into three parts: a fish‐bone‐type electrode array that provides the positive DEP force for focusing the suspended nanoparticles (NPs) near the inlet in the flow chamber; the second is for switching and guiding the focused NPs along the electrode surface to the target area, like a flow passing along a virtual channel; and a trapping electrode in the downstream for trapping and releasing the guided NPs. According to the simulation and experimental results, NPs can be aligned along the electrode of the focusing electrode and guided toward the target electrode by means of a positive DEP force between the top and bottom electrodes, with the effects of Brownian motion and Stokes force. In order to demonstrate the sequence of DEP manipulations, a PMMA‐NP suspension is introduced to the DEP chip; the size of the PMMA‐SMPs is about 300 nm. Furthermore, a LabVIEW program developed for sequence control of the AC signals for the multistep manipulations. Consequently, the DEP chip provides an excellent platform technology for the multistep manipulation of SMPs.
Integrating the LISFLOOD‐FP 2D hydrodynamic model with the CAESAR model: implications for modelling landscape evolution
Authors: Coulthard Tom J. , Neal Jeff C. , Bates Paul D. , Ramirez Jorge , de Almeida Gustavo A. M. , Hancock Greg R.
Published: September 2013

Landscape evolution models (LEMs) simulate the geomorphic development of river basins over long time periods and large space scales (100s–1000s of years, 100s of km2). Due to these scales they have been developed with simple steady flow models that enable long time steps (e.g. years) to be modelled, but not shorter term hydrodynamic effects (e.g. the passage of a flood wave). Nonsteady flow models that incorporate these hydrodynamic effects typically require far shorter time steps (seconds or less) and use more expensive numerical solutions hindering their inclusion in LEMs. The recently developed LISFLOOD‐FP simplified 2D flow model addresses this issue by solving a reduced form of the shallow water equations using a very simple numerical scheme, thus generating a significant increase in computational efficiency over previous hydrodynamic methods. This leads to potential convergence of computational cost between LEMs and hydrodynamic models, and presents an opportunity to combine such schemes. This paper outlines how two such models (the LEM CAESAR and the hydrodynamic model LISFLOOD‐FP) were merged to create the new CAESAR‐Lisflood model, and through a series of preliminary tests shows that using a hydrodynamic model to route flow in an LEM affords many advantages. The new model is fast, computationally efficient and has a stronger physical basis than a previous version of the CAESAR model. For the first time it allows hydrodynamic effects (tidal flows, lake filling, alluvial fans blocking valley floor) to be represented in an LEM, as well as producing noticeably different results to steady flow models. This suggests that the simplification of using steady flow in existing LEMs may bias their findings significantly. Copyright © 2013 John Wiley & Sons, Ltd.
A real‐space cellular automaton laboratory
Authors: Rozier Olivier , Narteau Clément
Published: September 2013

Geomorphic investigations may benefit from computer modelling approaches that rely entirely on self‐organization principles. In the vast majority of numerical models, instead, points in space are characterized by a variety of physical variables (e.g. sediment transport rate, velocity, temperature) recalculated over time according to some predetermined set of laws. However, there is not always a satisfactory theoretical framework from which we can quantify the overall dynamics of the system. For these reasons, we prefer to concentrate on interaction patterns using a basic cellular automaton modelling framework. Here we present the Real‐Space Cellular Automaton Laboratory (ReSCAL), a powerful and versatile generator of 3D stochastic models. The objective of this software suite, released under a GNU licence, is to develop interdisciplinary research collaboration to investigate the dynamics of complex systems. The models in ReSCAL are essentially constructed from a small number of discrete states distributed on a cellular grid. An elementary cell is a real‐space representation of the physical environment and pairs of nearest‐neighbour cells are called doublets. Each individual physical process is associated with a set of doublet transitions and characteristic transition rates. Using a modular approach, we can simulate and combine a wide range of physical processes. We then describe different ingredients of ReSCAL leading to applications in geomorphology: dune morphodynamics and landscape evolution. We also discuss how ReSCAL can be applied and developed across many disciplines in natural and human sciences. Copyright © 2013 John Wiley & Sons, Ltd.
A practical method to identify displaced and split stratospheric polar vortex events
Authors: Seviour William J. M. , Mitchell Daniel M. , Gray Lesley J.
Published: September 2013

Extreme variability of the stratospheric polar vortex during winter can manifest as a displaced vortex event or a split vortex event. The influence of this vortex disruption can extend downwards and affect surface weather patterns. In particular, vortex splitting events have been associated with a negative Arctic Oscillation pattern. An assessment of the impacts of climate change on the polar vortex is therefore important, and more climate models now include a well‒resolved stratosphere. To aid this analysis, we introduce a practical threshold‒based method to distinguish between displaced and split vortex events. It requires only geopotential height at 10 hPa to measure the geometry of the vortex using two‒dimensional moment diagnostics. It captures extremes of vortex variability at least, as well as previous methods when applied to reanalysis data, and has the advantage of being easily employed to analyze climate model simulations.
A COUNTRY FOR OLD MEN? LONG‐TERM HOME CARE UTILIZATION IN EUROPE
Authors: Balia Silvia , Brau Rinaldo
Published: September 2013

This paper investigates long‐term home care utilization in Europe. Data from the first wave of the Survey on Health, Ageing and Retirement (SHARE) on formal (nursing care and paid domestic help) and informal care (support provided by relatives) are used to study the probability and the quantity of both types of care. The overall process is framed in a fully simultaneous equation system that takes the form of a bivariate two‐part model where the reciprocal interaction between formal and informal care is estimated. Endogeneity and unobservable heterogeneity are addressed using a common latent factor approach. The analysis of the relative impact of age and disability on home care utilization is enriched by the use of a proximity to death (PtD) indicator built using the second wave of SHARE. All these indicators are important predictors of home care utilization. In particular, a strong significant effect of PtD is found in the paid domestic help and informal care models. The relationship between formal and informal care moves from substitutability to complementarity depending on the type of care considered, and the estimated effects are small in absolute size. This might call for a reconsideration of the effectiveness of incentives for informal care as instruments to reduce public expenditure for home care services. Copyright © 2013 John Wiley & Sons, Ltd.
Individual and combined effects of land use/cover and climate change on Wolf Bay watershed streamflow in southern Alabama
Authors: Wang Ruoyu , Kalin Latif , Kuang Wenhui , Tian Hanqin
Published: September 2013

Land use/cover (LULC) and climate change are two main factors affecting watershed hydrology. In this paper, individual and combined impacts of LULC and climate change on hydrologic processes were analysed applying the model Soil and Water Assessment Tool in a coastal Alabama watershed in USA. Temporally and spatially downscaled Global Circulation Model outputs predict a slight increase in precipitation in the study area, which is also projected to experience substantial urban growth in the future. Changes in flow frequency and volume in the 2030s (2016–2040) compared to a baseline period (1984–2008) at daily, monthly and annual time scales were explored. A redistribution of daily streamflow is projected when either climate or LULC change was considered. High flows are predicted to increase, while low flows are expected to decrease. Combined change effect results in a more noticeable and uneven distribution of daily streamflow. Monthly average streamflow and surface runoff are projected to increase in spring and winter, but especially in fall. LULC change does not have a significant effect on monthly average streamflow, but the change affects partitioning of streamflow, causing higher surface runoff and lower baseflow. The combined effect leads to a dramatic increase in monthly average streamflow with a stronger increasing trend in surface runoff and decreasing trend in baseflow. Copyright © 2013 John Wiley & Sons, Ltd.
MICRO CREDIT RISK METRICS: A COMPREHENSIVE REVIEW
Authors: Çelik Şaban
Published: September 2013

Default modelling is a general term used for several interrelated fields of risk management. Bond defaults, credit (loan) defaults, firm defaults and country defaults are examples of this kind. The scope and reason for existence of this study is to focus mainly on firm default. The purpose of this review is to shed light on the development and evaluation of the models proposed for predicting bankruptcy in terms of conceptualization, country distribution, sector specification, time dimension, variables used and findings reported. The current review includes firm default studies published in business fields such as accounting, economics, finance and management science. This review is distinct in that it seeks (i) to give a comprehensive examination of the models, (ii) to compare and contrast the features of the models and (iii) to show with a solid argument where future research should be focused. Copyright © 2013 John Wiley & Sons, Ltd.
Record neutron monitor counting rates from galactic cosmic rays
Authors: Oh Suyeon , Bieber John W. , Evenson Paul , Clem John , Yi Yu , Kim Yongkyun
Published: September 2013

Neutron monitors have recorded the flux of high‐energy Galactic cosmic rays for more than half a century. During the recent, prolonged, deep minimum in solar activity, many sources indicate that modulated Galactic cosmic rays have attained new Space Age highs. However, reported neutron monitor rates are ambiguous; some record new highs while others do not. This work examines the record of 15 long‐running neutron monitors to evaluate cosmic ray fluxes during the recent extraordinary solar minimum in a long‐term context. We show that ground‐level neutron rates did reach a historic high during the recent solar minimum, and we present a new analysis of the cosmic ray energy spectrum in the year 2009 versus year 1987. To do this, we define a reference as the average of eight high‐latitude neutron monitors, four in the Northern Hemisphere (Apatity, Inuvik, Oulu, Thule) and four in the Southern Hemisphere (Kerguelen, McMurdo, Sanae, Terre Adelie). Most stations display changes in sensitivity, which we characterize by a simple linear trend. After correcting for the change in sensitivity, a consistent picture emerges. With our correction, all stations considered display new highs at the recent solar minimum, approximately 3% above the previous record high. These increases are shown to be consistent with spacecraft observations.
Quality collaboratives and campaigns to reduce readmissions: What strategies are hospitals using?
Authors: Bradley Elizabeth H. , Sipsma Heather , Curry Leslie , Mehrotra Devi , Horwitz Leora I. , Krumholz Harlan
Published: September 2013

BACKGROUND

Reducing hospital readmissions is a national priority, and many hospitals are participating in quality collaboratives or campaigns.

OBJECTIVE

To describe and compare the current use of hospital strategies to reduce readmissions in 2 prominent quality initiatives—STAAR (State Action on Avoidable Rehospitalization) and H2H (Hospital‐to‐Home Campaign).

DESIGN

Cross‐sectional.

METHODS

Web‐based survey of hospitals that had enrolled in H2H or STAAR from May 2009 through June 2010, conducted from November 1, 2010 through June 30, 2011 (n = 599, response rate of 91%). We used standard frequency analysis and multivariable logistic regression to describe differences between STAAR and H2H hospitals.

RESULTS

Many hospitals were not implementing several of the recommended strategies. Although STAAR hospitals tended to be more likely to implement several strategies, differences were attenuated when we adjusted for region and ownership type. In multivariable models, STAAR hospitals compared with H2H hospitals were more likely to ensure outpatient physicians were alerted within 48 hours of patient discharge (63% vs 38%, P < 0.001), and more likely to provide skilled nursing facilities the direct contact number of the inpatient treating physician for patients transferred (53% vs 34%, P = 0.001). H2H hospitals were more likely to assign responsibility for medication reconciliation to nurses usually or always (80% vs 54%, P = 0.001) and more likely to give most or all discharged patients referrals to cardiac rehabilitation services (59% vs 41%, P = 0.001).

CONCLUSIONS

Substantial opportunity for improvement exists for hospitals engaged in STAAR or H2H quality initiatives. Journal of Hospital Medicine 2013;8:601–608. © 2013 Society of Hospital Medicine
Estimating hospital costs of catheter‐associated urinary tract infection
Authors: Kennedy Edward H. , Greene M. Todd , Saint Sanjay
Published: September 2013

Healthcare‐associated infections are common, costly, and potentially deadly. However, effective prevention strategies are underutilized, particularly for catheter‐associated urinary tract infection (CAUTI), one of the most common healthcare‐associated infections. Further, since 2008, the Centers for Medicare and Medicaid Services no longer reimburses hospitals for the additional costs of caring for patients who develop CAUTI during hospitalization. Given the resulting payment pressures on hospitals stemming from this decision, it is important to factor in cost implications when attempting to encourage decision makers to support infection prevention measures. To this end, we present a simple tool (with easy‐to‐use online implementation) that hospitals can use to estimate hospital costs due to CAUTI, both before and after an intervention, to reduce inappropriate urinary catheterization. Using previously published cost and risk estimates, we show that an intervention yielding clinically feasible reductions in catheter use can lead to an estimated 50% reduction in CAUTI‐related costs. Our tool is meant to complement the Society of Hospital Medicine's Choosing Wisely campaign, which highlights avoiding placement or continued use of nonindicated urinary catheters as a key area for improving decision making and quality of care while decreasing costs. Journal of Hospital Medicine 2013;8:519–522. © 2013 The Authors Journal of Hospital Medicine published by Wiley Periodicals, Inc. on behalf of Society of Hospital Medicine
To De‐Humdrumify Work Make the Job a Game!
Authors: Schaffer Robert H.
Published: September 2013

In order to best engage today's workforce, Schaffer says that leaders must cultivate lively, gamelike, action‐oriented workplaces that encourage rapid and significant results. A leader should consider why their employees find fulfillment in many leisure and volunteering activities but often find workplaces dull and stifling. He suggests carving short‐term goals out of longer ones, goals that can be reached rapidly and successfully. “Once you get started making everyone's job a game,” he writes, “sustaining and expanding the process becomes the game that you and every level of management must play.”
Detection of SCC initiation in austenitic stainless steel by electrochemical noise measurements
Authors: Ritter S. , Seifert H.‐P.
Published: September 2013

The electrochemical noise (EN) measurement technique is one of the most promising tools for continuous in situ corrosion monitoring in technical systems with a certain potential to be used for the detection of stress corrosion cracking (SCC). To evaluate the suitability of the EN technique for the detection of SCC initiation, a small but systematic test programme was started, performing EN measurements on type 304 austenitic stainless steel during constant extension rate tensile tests in aqueous thiosulphate solution at room temperature. SCC could be detected by EN measurements, which was verified by interruptions of the experiments at different stages, by testing steel with different degrees of sensitisation and by post‐test fractography in the scanning electron microscope. Conclusions on the cracking mechanism could be drawn based on the current noise signal pattern.
Investigations of the aqueous corrosion of pretreated magnesium alloys by means of electrochemical noise measurements
Authors: Bender S. , Holzhausen U. , Heyn A.
Published: September 2013

An important possibility to improve the corrosion behaviour of magnesium alloys is the application of protective coatings. The quality of such coatings depends mainly on the pretreatment and the exposure conditions after pretreatment. Since magnesium surfaces change much faster under atmospheric conditions than those of almost any other technical material, it is necessary to pay special attention to this particular feature. The activity of acid‐pickled surfaces of the magnesium alloys AZ31 and AZ91 in dependence on the exposure time and the humidity conditions was investigated with electrochemical noise (EN) measurements. In addition to pickling, plasma chemical vapour deposition processes open new possibilities for an economical, as well as ecologically quite safe, pretreatment. The results of EN investigations after acid pickling as well as specific plasma oxidation treatments of the two magnesium alloys after exposure to air with different humidities are presented.
Novel strategies for assessing the pitting corrosion resistance of stainless steel surfaces
Authors: Burkert A. , Klapper H. S. , Lehmann J.
Published: September 2013

Pitting corrosion is one of the most common mechanisms of surface damage on stainless steels. Electrochemical methods have been preferentially applied for the evaluation of the pitting corrosion resistance of stainless steels in the laboratory. Nevertheless, some of them are not reliable enough and in general the application of electrochemical methods in the field becomes difficult because of required deep understanding of corrosive phenomena and measurement technology. Therefore, new approaches for the evaluation of the pitting corrosion susceptibility of stainless steel surfaces in the laboratory as well as in the field are necessary. In the present paper two novel strategies including electrochemical noise measurements under anodic polarization for laboratory testing, and an indicator test to assess the susceptibility of stainless steel surfaces to pitting corrosion in the field are introduced. Experimental results concerning the influence of surface treatments on the pitting corrosion resistance on stainless steels have confirmed that final surface condition has a significant effect on their future pitting corrosion susceptibility. In addition, the pitting corrosion resistance of stainless steel surfaces was observed being specifically dependent on the achieved surface topography and in some cases independent on the roughness parameters of the surface.
Long term corrosion behavior of clad aluminum materials under different atmospheric conditions
Authors: Poltavtseva M. , Heyn A. , Boese E.
Published: September 2013

Aluminum materials roll‐plated on both sides are combinations of metals, which consist of clad layers on a core. To document the long term behavior of roof profiles of Alclad 3004 after long term exposure of about 40 years, evaluations were made at three locations in Germany with different climatic conditions. Locations with typical rural‐urban, coastal‐urban, and industrial climates were selected. The corrosion progress as a function of time and climatic type could be characterized by cross‐sections of roof specimens. To interpret the protective mechanism of the clad layer, the corrosion behavior of Alclad 6025 was characterized by electrochemical investigations. The results show that the passive clad material easily undergoes pitting in media containing specific amounts of chlorides. In case of contact of both cladding and core with an electrolyte the core alloy was protected because of the pitting corrosion of the cladding. This guarantees long‐time corrosion protection of constructions like facades or roofs under different atmospheric conditions.
N‐methyl‐D‐aspartate receptor antibodies in post–herpes simplex virus encephalitis neurological relapse
Authors: Hacohen Yael , Deiva Kumaran , Pettingill Phillipa , Waters Patrick , Siddiqui Ata , Chretien Pascale , Menson Esse , Lin Jean‐Pierre , Tardieu Marc , Vincent Angela , Lim Ming J.
Published: September 2013

Herpes simplex virus encephalitis (HSVE) is a devastating condition that relapses, often with a chorea in children, despite adequate antiviral treatment. At relapse, evidence of viral replication is frequently absent, suggesting that the relapse may be immune‐mediated. Seven children who had a neurological relapse following their initial encephalitis, identified from 20 cases of pediatric HSVE, were studied. Serum and/or cerebrospinal fluid (CSF) were tested for N‐methyl‐D‐aspartate receptor (NMDAR) and other antibodies previously reported in central nervous system autoimmunity. Five of the 7 relapsing children had choreoathetosis; 2 of these were NMDAR antibody–positive, 2 were negative (1 with HSV‐positive CSF), and 1 was not available for testing. An additional patient, who relapsed with cognitive regression but with no movement disorder, was also NMDAR antibody–positive. In 2 of the NMDAR antibody–positive patients who were treated at relapse and in 1 who was treated only after 10 years of having a relapsing encephalopathy, a beneficial response was observed. Neurological relapses after HSVE may frequently be immune‐mediated, particularly in children with chorea. NMDAR antibodies are common, and immunotherapy may be beneficial. © 2013 International Parkinson and Movement Disorder Society
Positive solution for four‐point nonlocal boundary value problems of fractional order
Authors: Ji Dehong , Ge Weigao
Published: September 2013

In this paper, we consider the existence of positive solution for four‐point nonlocal boundary value problems of fractional order. By means of some fixed point theorems, some results on the existence and multiplicity of positive solutions are obtained. Furthermore, we provide a representative example to illustrate a possible application of the established results. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis and Characterization of Phenol Formaldehyde Novolac Resin Derived from Liquefied Mountain Pine Beetle Infested Lodgepole Pine Barks
Authors: Zhao Yong , Zhang Boya , Yan Ning , Farnood Ramin. R.
Published: September 2013

In this study, mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) infested lodgepole pine (Pinus contorta Dougl.) barks are liquefied in phenol using either sulfuric acid or hydrochloric acid as the catalyst and two types of bark‐based phenol‐formaldehyde novolac resins, namely liquefied bark‐novolac resin S and liquefied bark‐novolac resin C are synthesized using the liquefied bark fractions. Compared to using hydrochloric acid in bark liquefaction, sulfuric acid catalyzed bark liquefaction reveals a higher liquefaction yield with a lower free phenol content and a higher molecular weight in the liquefied bark fraction. Liquefied bark‐novolac resins are found to have higher molecular weights, higher curing activation energies, and faster curing rates than the lab‐made control resins without bark components. The uncured liquefied bark‐novolac resins have higher thermal stability than the uncured lab‐made control resins. After curing with hexamethylenetetramine (HMTA), liquefied bark‐novolac resins show a similar post‐cured thermal stability to the lab‐made control resins. The findings suggest that the liquefied barks from MPB infested lodgepole pine are suitable for synthesizing novolac resins.
High‐resolution MRI encoding using radiofrequency phase gradients
Authors: Sharp Jonathan C. , King Scott B. , Deng Qunli , Volotovskyy Vyacheslav , Tomanek Boguslaw
Published: September 2013

Although MRI offers highly diagnostic medical imagery, patient access to this modality worldwide is very limited when compared with X‐ray or ultrasound. One reason for this is the expense and complexity of the equipment used to generate the switched magnetic fields necessary for MRI encoding. These field gradients are also responsible for intense acoustic noise and have the potential to induce nerve stimulation. We present results with a new MRI encoding principle which operates entirely without the use of conventional B0 field gradients. This new approach – ‘Transmit Array Spatial Encoding’ (TRASE) – uses only the resonant radiofrequency (RF) field to produce Fourier spatial encoding equivalent to conventional MRI. k‐space traversal (image encoding) is achieved by spin refocusing with phase gradient transmit fields in spin echo trains. A transmit coil array, driven by just a single transmitter channel, was constructed to produce four phase gradient fields, which allows the encoding of two orthogonal spatial axes. High‐resolution two‐dimensional‐encoded in vivo MR images of hand and wrist were obtained at 0.2 T. TRASE exploits RF field phase gradients, and offers the possibility of very low‐cost diagnostics and novel experiments exploiting unique capabilities, such as imaging without disturbance of the main B0 magnetic field. Lower field imaging (<1 T) and micro‐imaging are favorable application domains as, in both cases, it is technically easier to achieve the short RF pulses desirable for long echo trains, and also to limit RF power deposition. As TRASE is simply an alternative mechanism (and technology) of moving through k space, there are many close analogies between it and conventional B0‐encoded techniques. TRASE is compatible with both B0 gradient encoding and parallel imaging, and so hybrid sequences containing all three spatial encoding approaches are possible. Copyright © 2013 John Wiley & Sons, Ltd.