bluuebunny/crossref_metadata_2025 huggingface dataset:
Moisture and heat transfer in hybrid weft knitted fabric with artificial intelligence
Authors: Yazdi Motahareh Mokhtari , Semnani Dariush , Sheikhzadeh Mohammad
Published: June 2009

One of the most important properties of clothes is their ability to help the body's thermal system to keep the body temperature in its natural range, even if the environmental conditions or physical activities are outside the body's ideal range. Perspiring is one of the most important effects of physical activities in warm weather for shedding the body's excessive heat. Therefore, the basic requirement of a fabric worn next to the skin is to transfer this moisture to the atmosphere to reach comfort through the avoidance of a feeling of wetness and clamminess and also through the generation of a situation for the best surface evaporation of moisture. The main goal of this study was to achieve a kind of fabric that guarantees comfort for the body by good heat and moisture transport. To achieve this goal, a group of double‐surface fabrics containing hydrophilic and hydrophobe fibers were knitted, and their simultaneous heat and moisture transport was evaluated with the help of a perspiration‐simulation machine; the results were analyzed as transfer process plots. Also, the transmission of heat and moisture was evaluated for all of the samples by differential modeling as an artificial neural network. Effective parameters on heat and moisture transfer were taken into consideration with modeling and statistical methods. The results were analyzed to find a suitable fabric with optimum comfort. The final results showed that a fabric made of micropolyester filaments and cotton yarns on the bottom and top surfaces, respectively, had the best heat and moisture transfer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
In situ observation of polypropylene composites reinforced by nonmetals recycled from waste printed circuit boards during tensile testing
Authors: Zheng Yanhong , Shen Zhigang , Cai Chujiang , Ma Shulin , Xing Yushan
Published: June 2009

A great amount of work has been done over the past few years to reuse the nonmetals recycled from waste printed circuit boards in polypropylene (PP) composites. This is because of the very fast generation rate of nonmetal pollution in the world each year and the very fast growing rate of PP applications in industries. This work focuses on the dynamic effects of nonmetals of different particle sizes on the tensile properties and reinforcing mechanisms of nonmetal/PP composites by in situ scanning electron microscopy tensile testing. The observed results show that the dominant deformation mechanism in pure PP is shear yielding. When fine nonmetals are filled into PP, mass microcracks are initiated. The glass fibers first resist the cracks and undertake the loading when they propagate. The crazes propagate slowly and then break the glass fibers. When coarse nonmetals are filled into PP, interfacial debonding and mass microcracks are initiated. A crack is either terminated when it meets another fiber–particulate bundle or branched into finer mass crazing. Interfacial debonding, crack initiation and propagation, and fiber pullout and breakage dissipate tremendous energy. These factors cause improvements in the strength and rigidity of nonmetal/PP composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Three‐dimensional flow simulation of resin transfer molding utilizing multilayered fiber preform
Authors: Lee Seung Hwan , Yang Mei , Song Young Seok , Kim Seong Yun , Youn Jae Ryoun
Published: June 2009

Impregnation of the multi‐layered fiber preform with injected resin was analyzed by using the control volume finite element method for three‐dimensional mold filling simulation of the resin transfer molding (RTM). Numerically predicted flow fronts were compared with experimental data to validate accuracy of the numerical results and applicability of the numerical code developed in this study. Since isothermal Newtonian flow was assumed, Darcy's law and continuity equation were used as governing equations and permeability tensors employed for each layer. Flow simulation was conducted for the two types of mold geometries, i.e., rectangular plate and hollow cylinder. It was proven by comparing numerical results with experimental data that the simulation code is accurate enough to predict the flow patterns, especially when multi‐layered preforms were placed in the cylindrical mold. It was also found that the filling time was reduced by using outer gates compared with the case of inner gates. Three‐dimensional numerical simulation provided useful information for mold filling and can be used to design an optimum mold and make the RTM process efficient. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of monodisperse styrene/methyl methacrylate/acrylic acid latex using surfactant‐free emulsion copolymerization in air
Authors: Zhang Shengmiao , Chen Jianding , Taha Mohamed
Published: June 2009

Monodisperse styrene/methyl methacrylate/acrylic acid (St/MMA/AA) copolymer microspheres have been prepared with surfactant‐free emulsion polymerization in air. The presence of oxygen in the system not only caused an induction period but also decreased the average particle size (Dp). However increasing AA concentration ([AA]) gave a reduction in the induction period. The FTIR and NMR analysis of the latex copolymer confirmed that the correlation of the copolymer compositions with the feed compositions was much better at the lower [AA] than at the higher levels. The AA contents of the copolymers obtained in air were much lower than those of the copolymers obtained under N2 protection. Decreasing [AA] led to decrease in the copolymer molecular weight and broadening of the molecular weight distribution, but the particle size distribution (δ/Dp) was unaffected. In addition, the average particle diameter (Dp) was proportional to [AA]–0.255, and increasing comonomers feed content caused linear increase of Dp, and a monodisperse sample with final solids contents up to 34.2 wt % was obtained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Comparative study of the effect of different nanoparticles on the mechanical properties, permeability, and thermal degradation mechanism of HDPE
Authors: Chrissafis K. , Paraskevopoulos K. M. , Tsiaoussis I. , Bikiaris D.
Published: June 2009

In the present study, different series of high‐density polyethylene (HDPE) nanocomposites were prepared by melt mixing on a Haake‐Buchler Reomixer, containing 2.5 wt % of multiwall carbon nanotubes, pristine and modified montmorillonite, surface‐treated and ‐untreated SiO2 nanoparticles. From transmission electron micrographs, it was found that beyond a fine dispersion of nanoparticles into HDPE matrix, there are also some aggregates easily discriminated. As a result, there was a decrease in the tensile and impact strength of most of nanocomposites except Young's modulus, which was increased. Storage modulus as recorded from dynamic mechanical analysis was also increased in all nanocomposites, because HDPE becomes stiffer due to the incorporation of nanoparticles. The nucleation behavior of nanoparticles during crystallization was found to have no obvious effect on melting and crystallization temperature of HDPE. However, a small decrease in the heat of fusion in all nanocomposites was evidenced. Gas permeability of HDPE matrix in O2, N2, and CO2 was reduced in all nanocomposites compared with neat polymer. Thermal stability of HDPE was also enhanced due to the incorporation of different nanoparticles. From the kinetic analysis of thermal decomposition of HDPE, it was concluded that to describe the thermal degradation of HDPE and the studied nanocomposites, two consecutive mechanisms of nth‐order autocatalysis have to be considered. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of poly(trimethylene terephthalate) nanocomposites incorporating multi‐walled carbon nanotubes
Authors: Wu Chin‐San
Published: June 2009

Poly(trimethylene terephthalate) (PTT) nanocomposites containing multi‐walled carbon nanotubes (MWNTs) were prepared using a melt‐blending process. Acrylic acid‐grafted PTT (PTT‐g‐AA) and multihydroxyl‐functionalized MWNTs (MWNTs−OH) were used to improve the compatibility and dispersibility of MWNTs within the PTT matrix. The nanocomposites were characterized morphologically by transmission electron microscopy and chemically using Fourier transform infrared absorbance, 13C solid‐state nuclear magnetic resonance, and ultraviolet‐visible spectroscopy. The thermal and mechanical properties of the blends were also evaluated. The functionalized PTT‐g‐AA/MWNT–OH blend showed markedly enhanced thermal and mechanical properties due to the formation of ester bonds from the condensation of the carboxylic acid groups of PTT‐g‐AA with the hydroxyl groups of MWNT–OH. The optimal proportion of MWNT–OH in the blends was 1 wt %. In excess of this amount, compatibility between the organic and inorganic phases was compromised. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of the electron donor structure on the shelf‐lifetime of visible‐light activated three‐component initiator systems
Authors: Kim Dongkwan , Scranton Alec B. , Stansbury Jeffrey W.
Published: June 2009

In this study, we investigated the effect of electron donor structures on the shelf life of three‐component initiator systems which also included methylene blue (MB) as a photosensitizer and diphenyl iodonium salt (DPI) as an electron acceptor. For this research, N‐phenylglycine (NPG), N‐methyldiethanolamine (MDEA), N,N‐diisopropyl‐3‐pentylamine (DIPA), and 1,4‐diazabicyclo[2.2.2]octane (DABCO) were used as electron donors, with different of proton transfer efficiencies and radical/cation persistence. To aid characterization of the shelf‐life or dark storage stability of three‐component initiator systems, the relative polymerization kinetic profile of each freshly prepared initiator system was first obtained using photo‐DSC. The standardized photopolymerization reactions were repeated after various dark storage intervals. Thermal stability of each initiator system was compared by applying a ramped temperature program to monomer samples in the DSC in the dark. To analyze the kinetic changes as a function of storage time more quantitatively, we suggested an equation and characterized the shelf‐lifetime constant (k) of three‐component initiator systems. From the experiments and analysis, we conclude that the order of shelf‐life is consistent with the of radical cation (DH·+) persistence; DABCO > DIPA > MDEA > NPG, and inversely related to the proton transfer efficiency of the electron donor; NPG > MDEA > DIPA > DABCO. The effects of electron donor structures on thermal stability were consistent with the results of kinetic shelf‐life experiments. This investigation provides an effective means to characterize as well as predict shelf lifetimes of initiator systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of conductive polyaniline/nylon‐6 composite films by polymerization of aniline in nylon‐6 matrix
Authors: Nasybulin Eduard , Menshikova Irina , Sergeyev Vladimir , Levon Kalle
Published: June 2009

Polyaniline (PANI)/Nylon‐6 composite films were prepared by oxidative polymerization of aniline (ANI) inside host Nylon‐6 film. Such a composite has the desired electro‐active and mechanical properties to serve as a self‐standing functional unit. Comparative studies on sorption of ANI by Nylon‐6 matrix from various ANI containing media were conducted revealing superior ANI uptake from neutral ANI solution in water. ANI content was measured to be as high as 12%. Spectroscopic measurements showed that hydrogen bonding seemed to play important role in ANI sorption by Nylon‐6 matrix. Polymerization was monitored using atomic force microscopy and conductivity measurements. The morphology studies showed the appearance of PANI nanodomains on Nylon‐6 surface in the early stages of the polymerization. Eventually the domains coalesced during polymerization forming a continuous PANI layer. The conductivity measurements confirmed the change of the morphology from isolated islands to continuous conducting surface by drastic increase in conductivity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Ageing of polyamide 11 used in the manufacture of flexible piping
Authors: Romão Wanderson , Castro Eustáquio V. R. , Filho Elói A. S. , Guimarães Regina C. L. , Silva Ana L. N. , Teixeira Sylvia C. S. , de Paoli Marco‐A. , de Sena Geovane L.
Published: June 2009

The influence of temperature and pH on the ageing of piping made from polyamide 11 (PA‐11) was studied using water from an oilfield (pH = 5.5) and deionized water (pH = 7.0) with monitoring by corrected inherent viscosity (CIV) measurements. The hydrolytic degradation was more extensive at high temperatures in oilfield water. When the system reaches equilibrium, the pH affects mainly the CIV plateau values. Thermogravimetry, energy‐dispersive X‐ray spectroscopy, differential scanning calorimetry, X‐ray diffraction, and scanning electron microscopy measurements were also used to investigate aspects involved in the ageing PA‐11. The hydrolytic degradation of PA‐11 leads to formation of low molar mass compounds, such as oligomers dispersed in the polymeric matrix. This is a process that occurs preferentially in the amorphous domain of PA‐11, which leads to an increase in the degree of crystallinity and the formation of a new γ‐phase. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of melamine–formaldehyde–polyvinylpyrrolidone polymer resin for better industrial uses over melamine resins
Authors: Singh Man , Kumar Vinod
Published: June 2009

Melamine–formaldehyde–polyvinylpyrrolidone (MFP) polymer resin was prepared with 1 : 16 : 1 ratios of melamine, formaldehyde (CH2O), and polyvinylpyrrolidone amounts, respectively, by condensation polymerization at 6.9 pH. Structures were determined with IR, 1H‐NMR, and 13C‐NMR spectroscopies. Chemical shifts (δ, ppm) were analyzed with singlet at δ 4.5, duplet from 3.13 to 3.17 and a quartet at 1.5 to 2.2 ppm for methylene (CH2) bridging group, pyrrolidone, and polyvinyl constituents. The 3389.25, 1290.38, and 1655.28 cm−1 stretching frequencies of N, CH and COO groups, respectively, were noted on FTIR spectrum. The CN melamine units reacted with CH2O to adjoin with polyvinylpyrrolidone (PVP). An average viscosity molecular weight ($\bar{M}$v) 57,000 g mol−1 was obtained with Mark–Houwink–Sakurada equation. The chemical shift of N(CH2O)2Cpyrrolidone ring on 13C‐NMR spectra was shifted toward lower magnetic field at 175.18 ppm. The resin was partially miscible with water thereby densities and viscosities of aqueous solutions were measured at 298.15 K temperature. It showed higher densities and viscosities than those of water. The resin developed exceptionally higher adhesive strengthen when its 62.29‐μm uniform thin film was applied on surfaces of wooden strips. The resin showed micellar behavior at about 0.009 g/100 mL aqueous solution. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The physiological role of hormones in saliva
Authors: Gröschl Michael
Published: June 2009

The assessment of hormones in saliva has gained wide acceptance in clinical endocrinology. To date, there is no hypothesis as to why some hormones can be found in saliva, while others cannot, and whether there is a physiological consequence of this fact. A number of carefully performed studies give examples of important physiological hormonal activity in saliva. Steroids, such as androgens, act as pheromones in olfactory communication of various mammalian species, such as facilitating mating behavior in swine or serving as odor cues for rodent nestlings. Salivary peptide hormones, such as epidermal growth factor (EGF) and transforming growth factor‐α (TGF‐α), and amines such as melatonin, are involved in the regulation of inflammatory processes and in the promotion of cell proliferation, and contribute to a rapid wound healing in the oropharyngeal epithelia. Current data provide evidence of the involvement of salivary cytokines, such as interleukin‐8 and leptin, in tumorgenesis in the oral cavity and the salivary glands. The tumor tissues express and release significantly more of these cytokines than healthy glands. Consequently, the assessment of salivary hormone profiles may provide promising targets for diagnostic tumor markers.
Regulation, necessity, and the misinterpretation of knockouts
Authors: Davies Jamie
Published: June 2009

Much contemporary biology consists of identifying the molecular components that associate to perform biological functions, then discovering how these functions are controlled. The concept of control is key to biological understanding, at least of the physiological kind; identifying regulators of processes underpins ideas of causality and allows complicated, multicomponent systems to be summarized in relatively simple diagrams and models. Unfortunately, as this article demonstrates by drawing on published articles, there is a growing tendency for authors to claim that a molecule is a ‘regulator’ of something on evidence that cannot support the conclusion. In particular, gene knockout experiments, which can demonstrate only that a molecule is necessary for a process, are all too frequently being misinterpreted as revealing regulation. This logical error threatens to blur the important distinction between regulation and mere necessity and therefore to weaken one of our strongest tools for comprehending how organisms work.
Corporate sustainability and innovation in SMEs: Evidence of themes and activities in practice
Authors: Bos‐Brouwers Hilke Elke Jacke
Published: June 2009

Recently, innovation processes towards sustainable development have received increasing attention in academic literature. This research introduces the combination of insights from innovation theory, sustainable development practice and small business characteristics to unlock new knowledge on factors that influence the translation of sustainable innovation within small and medium‐sized enterprises (SMEs) into practice. The sustainability themes and activities as described for large companies (i.e. in the sustainability reporting and management literature) were used as starting point in this study. It presents empiric results of the PRIMA Project conducted within the rubber and plastics industry (RPI) on sustainable innovation activities.

It will show that many sustainable innovations are directed at the improvement of technological processes (eco‐efficiency) and to lower costs of production. These innovations can be seen as incremental. Companies with sustainability integrated in their orientation and innovation processes show value creation: the development of products new to the market (radical innovations) and cooperation with stakeholders. The PRIMA project shows that more insight in SME innovative characteristics and (e)valuation of sustainable innovation efforts provides opportunities to improve the sustainability performance of SMEs. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
How do institutional shareholders manipulate corporate environmental strategy to protect their equity value? A study of the adoption of ISO 14001 by Egyptian firms
Authors: Wahba Hayam
Published: June 2009

Theoretical as well as empirical evidence regarding the influence of institutional ownership on corporate environmental strategy not only is inconclusive but also reflects experience from either the Anglo‐American context or other developed countries. The underlying assumption of most of this literature is that institutional shareholders are always ‘active’ or ‘passive’ in their actions towards corporate environmental strategy. However, this study argues that this relationship might be moderated by various motivations such as legitimizing existence and operations, conforming with industry norms or lessening managerial entrenchment. Econometric analysis, using a sample of Egyptian firms, as hypothesized, demonstrated that institutional ownership exerted positive and significant effects on a corporation's tendency to adopt environmental management standards only when financial resources are available and investment opportunities are limited. A possible explanation of this finding is that Egyptian institutional investors are more likely to use corporate environmental responsibility to offset their inability to confront managerial discretionary power. An implication of this finding is that not only will different types of stakeholder ask for different levels of social and environmental responsibility, but also the same type of stakeholder may ask for different levels of social and environmental responsibility in different contexts. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Teaching ferroresonance in power system to undergraduate students by using MATLAB–SIMULINK
Authors: Vahidi B. , Abandansari A. Haghani
Published: June 2009

Accurate knowledge characteristics of a power system are very essential to have an idea of its operation conditions. The ferroresonant circuit exhibits oscillations characterized by frequency that is in accordance to the voltage applied on, and the currents circulating through the components of the circuit. The dominant frequency of these periodic oscillations could be the network frequency (fundamental ferroresonance) or a fraction of it (sub‐harmonic ferroresonance). This phenomenon (both fundamental and sub‐harmonic ferroresonance) is characterized by overvoltages or overcurrents, which may provoke the equipment damage and malfunctioning of the protective devices. The article presents an approach to teaching high voltage laboratory using specially designed exercises that can be done using MATLAB 6.5. This article present a MATLAB based technology to simulate ferroresonance in power system. Evaluation of the simulation with more than 30 students is very positive in terms of their developing confidence in and understanding of this simulation. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 347–357, 2011
Structure–Property Relationships of a Class of Carbamate‐Based Fatty Acid Amide Hydrolase (FAAH) Inhibitors: Chemical and Biological Stability
Authors: Vacondio Federica , Silva Claudia , Lodola Alessio , Fioni Alessandro , Rivara Silvia , Duranti Andrea , Tontini Andrea , Sanchini Silvano , Clapper Jason R. , Piomelli Daniele , Mor Marco , Tarzia Giorgio
Published: June 2009

Cyclohexylcarbamic acid aryl esters are a class of fatty acid amide hydrolase (FAAH) inhibitors, which includes the reference compound URB597. The reactivity of their carbamate fragment is involved in pharmacological activity and may affect their pharmacokinetic and toxicological properties. We conducted in vitro stability experiments in chemical and biological environments to investigate the structure–stability relationships in this class of compounds. The results show that electrophilicity of the carbamate influences chemical stability, as suggested by the relation between the rate constant of alkaline hydrolysis (log kpH9) and the energy of the lowest unoccupied molecular orbital (LUMO). Introduction of small electron‐donor substituents at conjugated positions of theO‐aryl moiety increased the overall hydrolytic stability of the carbamate group without affecting FAAH inhibitory potency, whereas peripheral non‐conjugated hydrophilic groups, which favor FAAH recognition, helped decrease oxidative metabolism in the liver.
Dynamic Transport in Li‐Conductive Polymer Electrolytes Plasticized with Poly(ethylene glycol)–Borate/Aluminate Ester
Authors: Kaneko Fuminari , Wada Shinta , Nakayama Masanobu , Wakihara Masataka , Kuroki Shigeki
Published: June 2009

The addition of plasticizers into Li+‐conductive solid polymer electrolytes (SPEs) is a commonly known technique to enhance the ionic conductivity. Among the used plasticizers, alkoxides of group‐13 elements [such as poly(ethylene glycol) (PEG)–borate ester] are promising candidates due to the Lewis acidity of the elements of this group (i.e. B, Al, and so on), which interact with the anions and may increase the degree of dissociation of the salts and the transport number of the SPEs. By means of pulsed‐gradient stimulated‐echo NMR (PGStE‐NMR) and AC impedance measurements, we investigate the effect of Lewis acidity originated from group‐13 elements on the transport number and the dissociation rate of SPEs containing various plasticizers. Our results show that the degree of salt dissociation is significantly enhanced by the addition of plasticizers including group‐13 elements, whereas only a small or negligible increase of the transport number is observed for these SPEs. We infer that the plasticizers exhibiting Lewis acidity associate with the anions, and that the associated pairs can migrate in the SPEs as fast as free anions, which results in a lower transport number than expected.
The implementation of socially responsible purchasing
Authors: Leire Charlotte , Mont Oksana
Published: June 2009

Social and ethical issues in the supply chain are gaining importance in all types of organizations. Therefore some public and private organizations have already started to introduce socially responsible purchasing practices. However, current practices are limited and seem unsystematic. There is also a difference between few front‐running organizations and the rest. It is therefore useful at this early stage to disseminate the knowledge and experiences based on the best‐performing organizations. This paper does that by developing a model of the socially responsible purchasing process that is based on the empirical and secondary data. The model reveals the five elementary steps that are necessary in the implementation of systematic socially responsible purchasing practices: developing internal policies; setting purchasing criteria that regard social issues; applying assurance practices; managing supplier relations; and building internal capacity. The model also points to the different activities in the process and their associated challenges. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Ecohydrology of dry regions of the United States: precipitation pulses and intraseasonal drought
Authors: Lauenroth William K. , Bradford John B.
Published: June 2009

Distribution of precipitation event sizes and interval lengths between events are important characteristics of arid and semi‐arid climates. Understanding their importance will contribute to our ability to understand ecosystem dynamics in these regions. Our objective for this paper was to present a comprehensive analysis of the daily precipitation regimes of arid and semi‐arid locations of the United States. We collected 30 years of daily precipitation and temperature data from 289 sites in the intermountain zone and 240 sites in the Great Plains for our analysis. The daily precipitation regimes at all sites were dominated by the smallest event sizes and the shortest intervals between events. Great Plains sites on average had more small events and more short intervals than sites in the intermountain zone. In both regions, small events and short intervals were significantly negatively correlated to all other sizes suggesting they were useful for characterizing precipitation regimes. Both the smallest precipitation events and the shortest intervals between precipitation events increased as mean annual temperature decreased. Small events were negatively, but short intervals were positively related to mean annual precipitation. Additional analysis of Great Plains data suggested both quantitative and qualitative differences between precipitation regimes in wet and dry climates. These differences are attributable in large part to the differences in the relationship between precipitation and the evaporative demand of the atmosphere between the semi‐arid and sub‐humid portions of the Great Plains. Copyright © 2009 John Wiley & Sons, Ltd.
Hydrological behaviour of grasslands of the Sandhills of Nebraska: water and energy‐balance assessment from measurements, treatments, and modelling
Authors: Sridhar Venkataramana , Wedin David A.
Published: June 2009

Understanding energy and water balance processes in the Sandhills is crucial to assess the land–atmosphere feedback effects. The Sandhills located in western Nebraska covers a vast grassland ecosystem with limited variability in vegetation and soil. However, the combined effect of topography, land cover, and micrometeorology by subjecting the land surface to various disturbances and treatments is rarely studied. The NOAH Land Surface Model (LSM) was used to estimate net radiation, latent, sensible, and ground heat (GH) fluxes as well as water balance components for two growing seasons between 2005 and 2006 in various plots at the Grasslands Destabilization Experimental (GDEX) site where these plots were subjected to four different treatments and located at two topographical locations, namely high and low positions. The simulated results of net radiation and GH fluxes correlated well with measurements. While the amount of precipitation received was between 900 and 1000 mm for both seasons, on a daily and sub‐daily time scale the partitioning of net radiation into latent, sensible, and GH fluxes showed high variability across the plots, primarily driven by vegetation and soil moisture. Total evapotranspiration and soil moisture averages suggested the influence of vegetation and the timing of precipitation also in controlling various land surface processes in the Sandhills. This study provides a framework for using the LSM to quantify the feedback effects and emphasizes the importance of microtopography and land treatments in the model environment. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of Enantiopure 2‐Aryl(Alkyl)‐2‐trifluoromethyl‐Substituted Morpholines and Oxazepanes
Authors: Nonnenmacher Jean , Grellepois Fabienne , Portella Charles
Published: June 2009

The synthesis of morpholines and oxazepanes derivatives containing a trifluoromethyl group on a quaternary carbon has been achieved from a common enantiopure O‐allyl amino ether precursor. Classic 6‐exo iodoamination provided the iodomorpholines, versatile synthetic intermediates, whereas a hydrozirconation/iodination sequence allowed the synthesis of oxazepanes by a 7‐endo cyclisation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
1,1′‐Binaphthyldiamine‐Based Lewis Bases as Readily Available and Efficient Organocatalysts for the Reduction of N‐Aryl and N‐Alkyl Ketimines
Authors: Guizzetti Stefania , Benaglia Maurizio , Celentano Giuseppe
Published: June 2009

The development of simple, low‐cost, efficient, and sustainable routes to enantiomerically pure amines is a topic of extraordinary interest, specially in view of future industrial applications. In this context, we wish to report a chemical and stereochemical efficient synthesis of chiral amines through the Lewis base activated trichlorosilane reduction of ketimines. An organocatalyst, easily prepared in a single step through the condensation of picolinic acid and commercially available 1,1′‐binaphthyldiamine, is the key element of this metal‐free methodology, that allowed the synthesis of chiral secondary and primary amines in high yields and stereoselectivity. Noteworthy, such catalysts are able to promote the reduction of N‐alkyl ketimines, often in quantitative yield and up to 87 % enantioselectivity; it is worth mentioning that for such transformations only one other organocatalytic system has been reported so far. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Switching the Regioselectivity of Direct C–H Arylation of 1,3‐Dimethyluracil
Authors: Čerňová Miroslava , Pohl Radek , Hocek Michal
Published: June 2009

An interesting dichotomy in the regioselectivity and mechanism of direct C–H arylation of 1,3‐dimethyluracil was observed. Its Pd‐catalyzed reactions with diverse aryl halides in the absence of CuI lead preferentially to 5‐aryluracils, while reactions in the presence of CuI give 6‐aryl derivatives as the major products. Cu‐mediated reactions (in the absence of a Pd catalyst) proceed with lower efficiency but give exclusively 6‐aryluracil derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Multi‐material incompressible flow simulation using the moment‐of‐fluid method
Authors: Schofield Samuel P. , Christon Mark A. , Dyadechko Vadim , Garimella Rao V. , Lowrie Robert B. , Swartz Blair K.
Published: June 2009

This paper compares the numerical performance of the moment‐of‐fluid (MOF) interface reconstruction technique with Youngs, LVIRA, power diagram (PD), and Swartz interface reconstruction techniques in the context of a volume‐of‐fluid (VOF) based finite element projection method for the numerical simulation of variable‐density incompressible viscous flows. In pure advection tests with multiple materials MOF shows dramatic improvements in accuracy compared with the other methods. In incompressible flows where density differences determine the flow evolution, all the methods perform similarly for two material flows on structured grids. On unstructured grids, the second‐order MOF, LVIRA, and Swartz methods perform similarly and show improvement over the first‐order Youngs' and PD methods. For flow simulations with more than two materials, MOF shows increased accuracy in interface positions on coarse meshes. In most cases, the convergence and accuracy of the computed flow solution was not strongly affected by interface reconstruction method. Published in 2009 by John Wiley & Sons, Ltd.
Foreign exchange market prediction with multiple classifiers
Authors: Qian Bo , Rasheed Khaled
Published: June 2009

Foreign exchange market prediction is attractive and challenging. According to the efficient market and random walk hypotheses, market prices should follow a random walk pattern and thus should not be predictable with more than about 50% accuracy. In this article, we investigate the predictability of foreign exchange spot rates of the US dollar against the British pound to show that not all periods are equally random. We used the Hurst exponent to select a period with great predictability. Parameters for generating training patterns were determined heuristically by auto‐mutual information and false nearest‐neighbor methods. Some inductive machine‐learning classifiers—artificial neural network, decision tree,k‐nearest neighbor, and naïve Bayesian classifier—were then trained with these generated patterns. Through appropriate collaboration of these models, we achieved a prediction accuracy of up to 67%. Copyright © 2009 John Wiley & Sons, Ltd.
Robust forecasting with exponential and Holt–Winters smoothing
Authors: Gelper Sarah , Fried Roland , Croux Christophe
Published: June 2009

Robust versions of the exponential and Holt–Winters smoothing method for forecasting are presented. They are suitable for forecasting univariate time series in the presence of outliers. The robust exponential and Holt–Winters smoothing methods are presented as recursive updating schemes that apply the standard technique to pre‐cleaned data. Both the update equation and the selection of the smoothing parameters are robustified. A simulation study compares the robust and classical forecasts. The presented method is found to have good forecast performance for time series with and without outliers, as well as for fat‐tailed time series and under model misspecification. The method is illustrated using real data incorporating trend and seasonal effects. Copyright © 2009 John Wiley & Sons, Ltd.
Auditory orienting and inhibition of return in mild traumatic brain injury: A FMRI study
Authors: Mayer Andrew R. , Mannell Maggie V. , Ling Josef , Elgie Robert , Gasparovic Charles , Phillips John P. , Doezema David , Yeo Ronald A.
Published: June 2009

The semiacute phase of mild traumatic brain injury (mTBI) is associated with deficits in the cognitive domains of attention, memory, and executive function, which previous work suggests may be related to a specific deficit in disengaging attentional focus. However, to date, there have only been a few studies that have employed dynamic imaging techniques to investigate the potential neurological basis of these cognitive deficits during the semiacute stage of injury. Therefore, event‐related functional magnetic resonance imaging was used to investigate the neurological correlates of attentional dysfunction in a clinically homogeneous sample of 16 patients with mTBI during the semiacute phase of injury (<3 weeks). Behaviorally, patients with mTBI exhibited deficits in disengaging and reorienting auditory attention following invalid cues as well as a failure to inhibit attentional allocation to a cued spatial location compared to a group of matched controls. Accordingly, patients with mTBI also exhibited hypoactivation within thalamus, striatum, midbrain nuclei, and cerebellum across all trials as well as hypoactivation in the right posterior parietal cortex, presupplementary motor area, bilateral frontal eye fields, and right ventrolateral prefrontal cortex during attentional disengagement. Finally, the hemodynamic response within several regions of the attentional network predicted response times better for controls than for patients with mTBI. These objective neurological findings represent a potential biomarker for the behavioral deficits in spatial attention that characterize the initial recovery phase of mTBI. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Contradiction in universal and particular reasoning
Authors: Medaglia Maria Teresa , Tecchio Franca , Seri Stefano , Di Lorenzo Giorgio , Rossini Paolo M. , Porcaro Camillo
Published: June 2009

A wide range of essential reasoning tasks rely on contradiction identification, a cornerstone of human rationality, communication and debate founded on the inversion of the logical operators “Every” and “Some.” A high‐density electroencephalographic (EEG) study was performed in 11 normal young adults. The cerebral network involved in the identification of contradiction included the orbito‐frontal and anterior‐cingulate cortices and the temporo‐polar cortices. The event‐related dynamic of this network showed an early negative deflection lasting 500 ms after sentence presentation. This was followed by a positive deflection lasting 1.5 s, which was different for the two logical operators. A lesser degree of network activation (either in neuron number or their level of phase locking or both) occurred while processing statements with “Some,” suggesting that this was a relatively simpler scenario with one example to be figured out, instead of the many examples or the absence of a counterexample searched for while processing statements with “Every.” A self‐generated reward system seemed to resonate the recruited circuitry when the contradictory task is successfully completed. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Experimental models for hepatitis C viral infection #
Authors: Boonstra Andre , van der Laan Luc J. W. , Vanwolleghem Thomas , Janssen Harry L. A.
Published: June 2009

Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease. The majority of infected individuals develop a persistent infection, which is associated with a high risk of liver cirrhosis and hepatocellular carcinoma. Since its discovery 20 years ago, progress in our understanding of this virus has been suboptimal due to the lack of good model systems. However, in the past decade this has greatly accelerated with the development of various in vitro cell culture systems and in vivo small-animal models. These systems have made a major impact on the field of HCV research, and have provided important breakthroughs in our understanding of HCV infection and replication. Importantly, the in vitro cell culture systems and the small-animal models have allowed preclinical testing of numerous novel antiviral compounds for the treatment of chronic HCV infection. In this article, we give an overview of current models, discuss their limitations, and provide future perspectives for research directed at the prevention and cure of hepatitis C. (Hepatology 2009.)
Are Transient Environmental Agents Involved in the Cause of Primary Biliary Cirrhosis? Evidence from Space–Time Clustering Analysis†
Authors: McNally Richard J. Q. , Ducker Samantha , James Oliver F. W.
Published: June 2009

The cause of primary biliary cirrhosis (PBC) is unclear. Both genetic and environmental factors are likely to contribute. Some studies have suggested that one or more infectious agents may be involved. To examine whether infections may contribute to the cause of PBC, we have analyzed for space–time clustering using population-based data from northeast England over a defined period (1987–2003). Space–time clustering is observed when excess cases of a disease are found within limited geographical areas at limited periods of time. If present, it is suggestive of the involvement of one or more environmental components in the cause of a disease and is especially supportive of infections. A second-order procedure based on

K

-functions was used to test for global space–time clustering using residential addresses at the time of diagnosis. The Knox method determined the spatiotemporal range over which global clustering was strongest.

K

-function tests were repeated using nearest neighbor thresholds to adjust for variations in population density. Individual space–time clusters were identified using Kulldorff's scan statistic. Analysis of 1015 cases showed highly statistically significant space–time clustering (

P

< 0.001). Clustering was most marked for cases diagnosed within 1–4 months of one another. A number of specific space–time clusters were identified. In conclusion, these novel results suggest that transient environmental agents may play a role in the cause of PBC. (Hepatology 2009.)
Adult learning and remodeling of hippocampal mossy fibers: Unheralded participant in circuitry for long‐lasting spatial memory
Authors: Routtenberg Aryeh
Published: June 2009

Two articles in this issue concerning the overexpression of GAP‐43 on mossy fiber growth are related to the plasticity of these axons in relation to learning and memory. © 2009 Wiley‐Liss, Inc.
Alcohol inhibition of neurogenesis: A mechanism of hippocampal neurodegeneration in an adolescent alcohol abuse model
Authors: Morris Stephanie A. , Eaves David W. , Smith Aleksander R. , Nixon Kimberly
Published: June 2009

Adolescents diagnosed with an alcohol use disorder show neurodegeneration in the hippocampus, a region important for learning, memory, and mood regulation. This study examines a potential mechanism by which excessive alcohol intake, characteristic of an alcohol use disorder, produces neurodegeneration. As hippocampal neural stem cells underlie ongoing neurogenesis, a phenomenon that contributes to hippocampal structure and function, we investigated aspects of cell death and cell birth in an adolescent rat model of an alcohol use disorder. Immunohistochemistry of various markers along with Bromo‐deoxy‐Uridine (BrdU) injections were used to examine different aspects of neurogenesis. After 4 days of binge alcohol exposure, neurogenesis was decreased by 33 and 28% at 0 and 2 days after the last dose according to doublecortin expression. To determine whether this decrease in neurogenesis was due to effects on neural stem cell proliferation, quantification of BrdU‐labeled cells revealed a 21% decrease in the dentate gyrus of alcohol‐exposed brains. Cell survival and phenotype of BrdU‐labeled cells were assessed 28 days after alcohol exposure and revealed a significant, 50% decrease in the number of surviving cells in the alcohol‐exposed group. Reduced survival was supported by significant increases in the number of pyknotic‐, FluoroJade B positive‐, and TUNEL‐positive cells. However, so few cells were TUNEL‐positive that cell death is likely necrotic in this model. Although alcohol decreased the number of newborn cells, it did not affect the percentage of cells that matured into neurons (differentiation). Thus, our data support that in a model of an adolescent alcohol use disorder, neurogenesis is impaired by two mechanisms: alcohol‐inhibition of neural stem cell proliferation and alcohol effects on new cell survival. Remarkably, alcohol inhibition of neurogenesis may outweigh the few dying cells per section, which implies that alcohol inhibition of neurogenesis contributes to hippocampal neurodegeneration in alcohol use disorders. © 2009 Wiley‐Liss, Inc.
Domino‐Heck Reactions of Carba‐ and Oxabicyclic, Unsaturated Dicarboximides: Synthesis of Aryl‐Substituted, Bridged Perhydroisoindole Derivatives
Authors: Celik Cumali , Kulu Irem , Ocal Nuket , Kaufmann Dieter E.
Published: June 2009

The CC coupling of the two bicyclic, unsaturated dicarboximides 5 and 6 with aryl and heteroaryl halides gave, under reductive Heck conditions, the C‐aryl‐N‐phenyl‐substituted oxabicyclic imides 7a–c and 8a–c (Scheme 3). Domino‐Heck CC coupling reactions of 5, 6, and 1b with aryl or heteroaryl iodides and phenyl‐ or (trimethylsilyl)acetylene also proved feasible giving 8, 9, and 10a–c, respectively (Scheme 4). Reduction of 1b with LiAlH4 (→11) followed by Heck arylation and reduction of 5 with NaBH4 (→13) followed by Heck arylation open a new access to the bridged perhydroisoindole derivatives 12a,b and 14a,b with prospective pharmaceutical activity (Schemes 5 and 6).
New Polyketides from Endophytic Diaporthe sp. XZ‐07
Authors: Yuan Lin , Lin Xiang , Zhao Pei‐Ji , Ma Juan , Huang Yao‐Jian , Shen Yue‐Mao
Published: June 2009

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Four new polyketides, namely rel‐(2R,3S,4R,5R)‐4‐ethyltetrahydro‐3‐methyl‐5‐propylfuran‐2,3‐diol (1), methyl 5‐[(1R)‐1‐hydroxyethyl]‐γ‐oxofuran‐2‐butanoate (2), butyl 5‐[(1R)‐1‐hydroxyethyl]‐γ‐oxofuran‐2‐butanoate (3), and 3,4‐dihydro‐5′‐[(1R)‐1‐hydroxyethyl][2,2′‐bifuran]‐5(2H)‐one (4), together with three known ones, 5‐[(1R)‐1‐hydroxethyl)‐γ‐oxofuran‐2‐butanoic acid (5), phomopsolide B (6), and (2S,3S)‐3,6‐dihydro‐6‐oxo‐2‐[(1E)‐2‐{(4S,5S)‐2,2,5‐trimethyl‐1,3‐dioxolan‐4‐yl]ethenyl}‐2H‐pyran‐3‐yl (2E)‐2‐methylbut‐2‐enoate (7), were isolated from the submerged cultures of the endophytic fungal strain Diaporthe sp. XZ‐07 of Camptotheca acuminate. The structures of the new compounds were established by 1D‐ and 2D‐NMR and MS data and by Mosher's method. Compound 6 significantly inhibited the growth of human‐tumor HeLa cells with an IC50 of 5.7 μg/ml by the MTT assay (MTT=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide).