bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absence of nonlocal resistance in microstructures of PbTe quantum wells
Authors: Kolwas K. A. , Grabecki G. , Trushkin S. , Wróbel J. , Aleszkiewicz M. , Cywiński Ł. , Dietl T. , Springholz G. , Bauer G. 
Published: December 2012

AbstractWe report on experiments allowing to set an upper limit on the magnitude of the spin Hall effect and the conductance by edge channels in quantum wells of PbTe embedded between PbEuTe barriers. We reexamine previous data obtained for epitaxial microstructures of n‐type PbSe and PbTe, in which pronounced nonlocal effects and reproducible magnetoresistance oscillations were found. Here we show that these effects are brought about by a quasi‐periodic network of threading dislocations adjacent to the BaF2 substrate, which give rise to a p‐type interfacial layer and an associated parasitic parallel conductance. We then present results of transport measurements on microstructures of modulation doped PbTe/(Pb,Eu)Te:Bi heterostructures for which the influence of parasitic parallel conductance is minimized, and for which quantum Hall transport had been observed, on similar samples, previously. These structures are of H‐shaped geometry and they are patterned of 12 nm thick strained PbTe quantum wells embedded between Pb0.92Eu0.08Te barriers. The structures have different lateral sizes corresponding to both diffusive and ballistic electron transport in non‐equivalent L valleys. For these structures no nonlocal resistance is detected confirming that PbTe is a trivial insulator. The magnitude of spin Hall angle γ is estimated to be smaller than 0.02 for PbTe/PbEuTe microstructures in the diffusive regime.
Unified privacy analysis of new‐found RFID authentication protocols
Authors: Alagheband Mahdi R. , Aref Mohammad R. 
Published: December 2012

ABSTRACTUbiquitousness of Radio Frequency Identification (RFID) systems with inherent weaknesses has been a cause of concern about their privacy and security. Therefore, secure protocols are essentially necessary for the RFID tags to guarantee privacy and authentication among them and the reader. This paper inspects privacy in the RFID systems. First, we survey four new‐found RFID authentication protocols, and then, their weaknesses in formal privacy model are analyzed. Although the authors of the schemes claimed that their protocols completely resist privacy attacks, we formally prove that all of them suffer from the family of traceability attacks. Furthermore, not only are the four improved protocols proposed to prevent the aforementioned attacks, but also we provide formal analysis to guarantee the security and privacy of the proposed enhancements. Copyright © 2012 John Wiley & Sons, Ltd.
Confidence intervals for odds ratio and relative risk based on the inverse hyperbolic sine transformation
Authors: Fagerland Morten W. , Newcombe Robert G. 
Published: December 2012

AbstractThe inverse hyperbolic sine transformation can be used to shorten the standard delta logit interval for the odds ratio and the delta log interval for the relative risk. As it stands, this transformation does not provide sufficient coverage. A pseudo‐frequency modification is suggested and evaluated. The modification achieves an improvement in coverage for both the odds ratio and the relative risk and a further improvement in interval width for the odds ratio. We also find that another closed form interval, called MOVER‐R Wilson, which is based on the method of variance estimates recovery, performs well. When the more complex and software demanding intervals, such as the asymptotic score, are unavailable, the adjusted inverse sinh intervals and MOVER‐R Wilson provide two simple approaches to interval estimation of the odds ratio and the relative risk. Copyright © 2012 John Wiley & Sons, Ltd.
Teaching and Learning: Using Experiential Learning and Reflection for Leadership Education
Authors: Guthrie Kathy L. , Jones Tamara Bertrand 
Published: December 2012

AbstractExperiential education and learning should be used in framing leadership education. This chapter will explore how leadership education in higher education can be taught from an experiential education framework. International Leadership Association overarching Teaching and Learning Guiding Question: “What are students' developmental levels and what teaching and learning methods are most appropriate to ensure maximum student learning?”
Importance of exergy for analysis, improvement, design, and assessment
Authors: Dincer I. , Ratlamwala T.A.H. 
Published: December 2012

This study discusses what exergy analysis brings new to the system design, analysis, assessment, and improvement of energy systems. It also presents how efficiencies are defined for performance assessment. Case studies are given to explain how system exergy analysis is performed, and its efficiencies are evaluated for comparison. Exergy destruction rates for each component of the systems are also studied and presented to investigate the possibilities for determining the magnitudes and improving the performance.This article is categorized under:

Energy Efficiency > Economics and Policy
Energy Efficiency > Systems and Infrastructure
Mit N‐Methylpiperidin stabilisierte Halogenalane
Authors: Veith Michael , Kirs Tatjana , Huch Volker 
Published: December 2012

AbstractAlanes of the formula HxAlX3–x (x = 0, 1, 2, 3; X = Cl, Br, I) and the mixed halogen species HAlClBr were synthesized as N‐methyl‐piperidin (nmp) adducts HxAlX3–x·znmp (z = 1, 2) and HAlClBr·2nmp by different routes. The crystal and molecular structures of (H3Al·nmp)2, H2AlBr·2nmp, H2AlI·2nmp, the isotypic and isomorphous HAlBr2·2nmp, HAlI2·2nmp, as well as ACl3·nmp, ABr3·nmp, AI3·nmp, and HAlClBr·2nmp are described. The aluminum atoms in these molecular structures either form a pentagonal bipyramid as coordination sphere with the amine bases in apical positions or are in the center of a distorted tetrahedron (AlCl3·nmp, ABr3·nmp, AI3·nmp). In the nmp adduct of alane, a central Al2H2 ring is formed by dimerisation of AlH3, each aluminum atom displaying a further nmp ligand together with two terminal hydrogen atoms. The influence of the halogen atoms on the hydrogen bonds in the iso‐structural compounds were studied by IR spectroscopy, showing in both series H2AlX·2nmp and HAlX2·2nmp (X = Cl, Br, I) a dependence of ν(Al–H) on the substitution pattern: 1770.2–1775.2–(not measured) cm–1 (H2AlX) and 1785.0–1788.0–1791.0 cm–1 (HAlX2). The δ values of the 27Al‐NMR spectra in solution show dependences on the halide numbers bonded to aluminum and display a regular growth with heavier element in the H2AlX·2nmp series δ (27Al): 121.2 (Cl), 126.0 (Br), 131.5 (I)], whereas they have an unsteady evolution in the HAlX2·2nmp series [δ (27Al): 118.0 (Cl), 122.0 (Br), 108.0 (I)] and the AlX3·nmp series [δ (27Al): 102.1 (Cl), 104.8 (Br), 61.9 (I)].
A Biomechanical Analysis of Treatment Options for Enchondromas of the Hand
Authors: Pianta Teresa J. , Baldwin Paul S. , Obopilwe Elifho , Mazzocca Augustus D. , Rodner Craig M. , Silverstein Eric A. 
Published: December 2012

Purpose Enchondromas are the most common benign bone tumor affecting the hand. Standard treatment has consisted of curettage with bone grafting. It has become increasingly common for surgeons to use biologic cement in these cases. The purpose of this study was to evaluate different treatment options used to fill voids after curettage of hand enchondromas to determine if any provide more rigid fixation. Methods A cadaveric model of hand enchondromas was designed by making a standardized size corticotomy (0.6×1.0 cm) in 60 cadaver metacarpals. Resultant voids were then filled with either no material, bovine demineralized bone matrix (Synthes Paoli, PA, USA), or one of two different calcium phosphate bone cements: a carbonated apatite (Synthes Norian SRS Skeletal Repair System) and a hydroxyapatite (Stryker HydroSet) calcium phosphate. An apex dorsal three-point bend was applied to the metacarpals through an MTS machine, and load to failure and stiffness were recorded. Results Biomechanically, load to failure for intact metacarpals was significantly superior to those in which a corticotomy was created ( p=0.04). There was a significant increase in load to failure between the metacarpals treated with the calcium phosphate bone cement and the negative controls ( p=0). Conclusions In a biomechanical analysis of a cadaveric model of hand enchondromas, calcium phosphate bone cement provided significantly increased strength as compared to curettage alone and approximated the strength of intact metacarpals. It is unknown whether the use of biologic cements in this clinical setting leads to less postoperative immobilization, earlier digital motion, a quicker return to work, or increased patient satisfaction.
Micellar and Interfacial Behavior of Cationic Benzalkonium Chloride and Nonionic Polyoxyethylene Alkyl Ether Based Mixed Surfactant Systems
Authors: Nandni Durgesh , Mahajan Rakesh Kumar 
Published: December 2012

AbstractMicellar and interfacial properties of mixed surfactant systems comprising benzalkonium chloride, a cationic surfactant and nonionic polyoxyethylene alkyl ether surfactants (POE: C10E7, C10E8, C10E9, C10E10) have been investigated by surface tension, fluorescence and dynamic light scattering techniques. Critical micelle concentration (CMC) for different mixing mole fractions has been investigated by surface tension and fluorescence measurements. Ideal CMC, mixed micellar composition (X1m, X1σ), interaction parameters for mixed micelles (βm) and adsorption monolayer (βσ), surface excess concentration (Гmax), minimum area per molecule (Amin) and related thermodynamic properties have also been determined. Lowering of the CMC and negative interaction parameter values indicate synergism in the mixed micelle and monolayer formed, whereas, thermodynamic parameters evaluated for the proposed mixed systems indicate stability of the resulting micelles and monolayer. Micellar aggregation number (Nagg) and hydrodynamic diameter (Dh) computed from fluorescence and dynamic light scattering measurements respectively illustrate micellar growth in the mixed state. Results obtained for the proposed mixed systems can be helpful in designing smart materials for industrial surfactant based formulations.
Seasonal distribution of coastal mesozooplankton community in relation to the environmental factors in İskenderun Bay (north-east Levantine, Mediterranean Sea)
Authors: Kurt Tuba Terbiyik , Polat Sevim 
Published: December 2012

Mesozooplankton was studied during 2008 in coastal waters of the İskenderun Bay in order to determine seasonal changes in abundance, biomass, community structure and their relationship with environmental factors. Samples were collected seasonally at five stations using WP-2 net of 200 µ mesh size by vertical hauls. A total of 23 planktonic groups including 30 copepod species, 4 cladocerans and 4 chaetognaths were identified. Copepods were the most important group during the whole period of survey. Penilia avirostris was found to be dominant in spring, while Paracalanus parvus in summer and winter, and Acrocalanus gibber in autumn. Mesozooplankton abundance varied from 438 ind m−3 (autumn) to 7163 ind m−3 (spring), while biomass varied between 2.2 mg m−3 (summer) and 52.9 mg m−3 (autumn). Differences in abundance and biomass between seasons were statistically significant (P < 0.01). Clear seasonal distribution patterns were observed in the area. Two peaks in abundance were defined: a major peak in spring and a second minor one in autumn. It seems that the trophic element was the main factor affecting the density distribution of zooplankton populations, whereas species distributions were more affected by hydrographical parameters, namely: seawater temperature and salinity.
TIKAL'S EARLY CLASSIC DOMINATION OF THE GREAT WESTERN TRADE ROUTE: CERAMIC, LITHIC, AND ICONOGRAPHIC EVIDENCE
Authors: Woodfill Brent K.S. , Andrieu Chloé 
Published: December 2012

AbstractThis article reviews new evidence suggesting that Tikal and its allies controlled trade along the Pasión River during the latter half of the Early Classic period (ca.a.d.460–550) and the possible impacts this had on geopolitical interaction. Recent data in the Candelaria Caves and other Pasión River sites showed the strong influence of Tikal during this time period that could indicate that they were active agents in interregional trade between the Maya highlands and lowlands. A quantitative reevaluation of the Pennsylvania lithic collection does demonstrate an important change in Tikal's importation of both obsidian and jade during the Early Classic period. Together, the stylistic changes in the locally manufactured ceramics and the drastic increase of lithic raw materials at Tikal strongly suggest that Tikal was directly or indirectly controlling the Chixoy-Pasión trade route at this time. After the defeat of Tikal by Caracol ina.d.562, it apparently lost this influence, ceasing to be a strong agent in jade and obsidian production and exchange, instead becoming a wealthy consumer.
LOS MALACATES ARQUEOLÓGICOS DE LA PENÍNSULA DE YUCATAN
Authors: Álvarez Héctor Hernández , May Nancy Peniche 
Published: December 2012

AbstractEl trabajo presenta una propuesta de tipología de malacates procedentes de distintos sitios de las tierras bajas mayas del norte tales como Chichen Itza, Ciudad Caucel, Dzidzilche, Ek Balam, Poxila, Siho, Isla Cerritos, Ichpaatun y Xaman Susula. Tales malacates corresponden a temporalidades que van desde el período preclásico hasta el posclásico. El análisis de esta muestra se basa en la correlación de sus atributos formales. Otros atributos tales como el tipo cerámico, el contexto del hallazgo y sus elementos decorativos y simbólicos también son considerados. El principal objetivo es demostrar que en la península de Yucatan hay evidencia de una continuidad de la presencia de la industria textil, así como cambios en la forma y el uso de los malacates, que muy probablemente sirvieron para el hilado de fibras de algodón. Consideramos que estos objetos en el área maya, muestran una estrecha relación con las labores femeninas, esto a partir de su contrastación con datos provenientes de las fuentes etnohistóricas, de las representaciones iconográficas sobre la actividad textil y los mismos malacates provenientes de otras regiones de Mesoamérica, principalmente el centro de México. De manera particular, pretendemos determinar si es posible obtener información complementaria sobre el tipo de fibras que se hilaban con ellos o cuestiones más complejas, como la atribución de género y estatus, que son aspectos recurrentes en la interpretación de estos materiales arqueológicos.
Chronic elevation of pulmonary microvascular pressure in chronic heart failure reduces bi‐directional pulmonary fluid flux
Authors: Dixon Dani‐Louise , Mayne George C. , Griggs Kim M. , de Pasquale Carmine G. , Bersten Andrew D. 
Published: December 2012

AimsChronic heart failure leads to pulmonary vascular remodelling and thickening of the alveolar–capillary barrier. We examined whether this protective effect may slow resolution of pulmonary oedema consistent with decreased bi‐directional fluid flux.Methods and resultsSeven weeks following left coronary artery ligation, we measured both fluid flux during an acute rise in left atrial pressure (n = 29) and intrinsic alveolar fluid clearance (n = 45) in the isolated rat lung. Chronic elevation of pulmonary microvascular pressure prevented pulmonary oedema and decreased lung compliance when left atrial pressure was raised to 20 cmH2O, and was associated with reduced expression of endothelial aquaporin 1 (P = 0.03). However, no other changes were found in mediators of fluid flux or cellular fluid channels. In isolated rat lungs, chronic LV dysfunction (LV end‐diastolic pressure and infarct circumference) was also inversely related to alveolar fluid clearance (P ≤ 0.001). The rate of pulmonary oedema reabsorption was estimated by plasma volume expansion in eight patients with a previous clinical history of chronic heart failure and eight without, who presented with acute pulmonary oedema. Plasma volume expansion was reduced at 24 h in those with chronic heart failure (P = 0.03).ConclusionsChronic elevation of pulmonary microvascular pressure in CHF leads to decreased intrinsic bi‐directional fluid flux at the alveolar–capillary barrier. This adaptive response defends against alveolar flooding, but may delay resolution of alveolar oedema.
Gastrojejunal Feeding Tube Use by Gastroenterologists in a Pediatric Academic Center
Authors: Al‐Zubeidi Dina , Demir Hulya , Bishop Warren P. , Rahhal Riad M. 
Published: December 2012

ABSTRACTBackground and Objectives:Enteral feeding through gastrojejunal (GJ) tubes is an established method of nutrition for patients with feeding difficulty who do not tolerate intragastric feedings. The pediatric literature about the long‐term outcome, safety, and complications of different GJ tubes and placement methods is lacking. Our study aims to provide information about indications, techniques, and long‐term outcome of GJ tube use in children.Methods:Retrospective chart review for GJ tube placement procedures was used at our center for 10 years (1999–2009). Data collected included demographics, placement indications, underlying diagnosis, tube type, placement methods, complications, tube survival, and patient outcome.Results:Thirty‐three patients using GJ tubes were identified, with a total of 160 successful procedures documented (overall success rate of 97.6%). At initial placement, the mean age was 6 years (range 0.6–21.6) and the mean weight was 19.4 kg (range 6.6–72.2). Patients had a mean of 4.9 tubes placed per patient (range 1–20) during a follow‐up of 26.8 months (range 0.4–115.3). The most common indications for replacement included accidental dislodgement, tube obstruction, coiling back into the stomach, and broken tube component. At the end of the study, 39% continued using GJ tubes, 30% were transitioned back to gastrostomy or oral feeds, and 15% underwent a surgical intervention.Conclusions:Long‐term GJ tube use is possible and safe in children. Various feeding tubes and placement methods can be used by pediatric gastroenterologists to provide long‐term jejunal feeds in children.
Meeting sustainability challenges of mega‐event flagships
Authors: Deng Ying , Poon S.W. 
Published: December 2012

PurposeA mega‐event flagship (MEF) refers to a popular instrument developed for staging a mega‐event and catalyzing area‐based urban regeneration. Despite its lasting appeal and controversial nature, insufficient research on its critical early stage has been done to provide useful analysis. When the clients lack appropriate capabilities to confront sustainability challenges, MEFs may end up functioning poorly in the post‐event era and even hindering the progress of intended renewals. The purpose of this study is to enhance MEF clients’ capabilities in meeting sustainability challenges at the early stage and ultimately producing responsible MEFs of enduring worth.Design/methodology/approachThe multiple‐case study method was adopted due to its widely recognized reliance on multiple sources to facilitate in‐depth analyses. Data were collected through archival records, documentation, direct observation and participant observation.FindingsBy proposing a comprehensive development framework based on the findings of multiple‐case studies, this paper corrects a misunderstanding of such a development being an end in itself, and contributes new insights into the definitional early stage of MEFs.Social implicationsThe fact that MEFs are a global phenomenon as well as a local undertaking leads to a need to develop a database of useful lessons and critical decisions from previous MEFs, to establish a best practice targets system in future research.Originality/valueAs an initial attempt, this paper lays the groundwork for research on MEFs by investigating how mega‐event hosts have prepared in meeting its sustainability challenges.
A historical perspective of counterproductive work behavior targeting the organization
Authors: Klotz Anthony C. , Buckley M. Ronald 
Published: December 2012

PurposeThe purpose of this paper is to chronicle the study of deviant behavior aimed at the organization, or CWB‐O, from the dawn of the Industrial Revolution to the present day.Design/methodology/approachCounterproductive work behaviors that have been documented and studied since the Industrial Revolution were systematically reviewed and discussed.FindingsOver the past few centuries, employees have engaged in behaviors that harm their organizations; as organizations have become more complex, however, employees have found many more ways to engage in CWB‐O. Further, recent advances in technology have made employee CWB‐O much more ambiguous.Research limitations/implicationsThe study of CWB‐Os will remain a rich area for researchers as the boundaries between work and personal life continue to blur, as employees develop new forms of CWB‐O, and as employers increase their use of technology to detect employee deviance.Practical implicationsAs the penetration of technology into job roles grows and the use of personal mobile devices becomes institutionalized, managers now must decide how much company time they will tolerate their employees spending on personal issues while at work. Put another way, managers must cope with the reality that a certain amount of what was once considered deviant behavior in the workplace may now be a minimum expectation of employees.Originality/valueThis paper builds a historical foundation of the present conceptualization of CWB‐O, thereby providing scholars with a greater understanding of what past events drove the emergence of the types of CWB‐O that are prevalent today and why some counterproductive behaviors may have become less prevalent.
Modeling in vitro cholesterol reduction in relation to growth of probiotic Lactobacillus casei
Authors: Kumar Alok , Kumar Mukesh , Ghosh Moushumi , Ganguli Abhijit 
Published: December 2012

AbstractLactobacillus casei LA‐1 isolated from a nondairy fermented source was evaluated for its in vitro ability to reduce cholesterol. The bacterium tested positive for bile salt deconjugation in relation to cholesterol removal. Tested growth‐associated physiological variables such as pH, temperature and inoculum size were all found to have significant effects on in vitro cholesterol reduction and biomass production (both P < 0.005). Furthermore, a central composite design was used to evaluate the effects of significant variables and their interactions. A linear regression model was developed for in vitro cholesterol reduction as a function of growth‐associated variables. Maximum cholesterol reduction achieved was 45% whereas maximum biomass yield of 2.34 optical density was observed at the central point. Our study possibly indicates that the growth of L. casei LA‐1 depends on its cholesterol removing ability.