bluuebunny/crossref_metadata_2025 huggingface dataset:
Green’s Symmetries in Finite Digraphs
Authors: Parks Allen D.
Published: August 2011

The semigroup DV of digraphs on a set V of n labeled vertices is defined. It is shown that DV is faithfully represented by the semigroup Bn of n ´ n Boolean matrices and that the Green’s L, R, H, and D equivalence classifications of digraphs in DV follow directly from the Green’s classifications already established for Bn. The new results found from this are: (i) L, R, and H equivalent digraphs contain sets of vertices with identical neighborhoods which remain invariant under certain one-sided semigroup multiplications that transform one digraph into another within the same equivalence class, i.e., these digraphs exhibit Green’s isoneighborhood symmetries; and (ii) D equivalent digraphs are characterized by isomorphic inclusion lattices that are generated by their out-neighborhoods and which are preserved under certain two-sided semigroup multiplications that transform digraphs within the same D equivalence class, i.e., these digraphs are characterized by Green’s isolattice symmetries. As a simple illustrative example, the Green’s classification of all digraphs on two vertices is presented and the associated Green’s symmetries are identified.
A practical microreactor for electrochemistry in flow
Authors: Watts Kevin , Gattrell William , Wirth Thomas
Published: August 2011

A microreactor for electrochemical synthesis has been designed and fabricated. It has been shown that different reactions can be carried out successfully using simple protocols.
Is Small Artery Elasticity Decreased Prior to Intima-Media Thickening in Patients with Longstanding Rheumatoid Arthritis?
Authors: HINKEMA HELMY J. , NIENHUIS HANS L.A. , de GROOT LODEWIJK , SMIT ANDRIES J. , van ROON ARIE M. , BIJL MARC , POSTHUMUS MARCEL D.
Published: August 2011

Objective.

To determine small artery elasticity (SAE) in patients with longstanding rheumatoid arthritis (RA) in comparison to healthy controls, and to investigate its relation to markers of endothelial cell activation, disease activity, joint damage, and the presence of atherosclerosis.

Methods.

Forty-nine patients with RA and 50 age- and sex-matched healthy controls were studied. Traditional cardiovascular risk factors and disease-related factors were recorded. SAE was measured noninvasively by pulse-wave analysis (PWA). Endothelial activation was assessed by measuring levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) and von Willebrand factor (vWF). Carotid intima-media thickness (IMT), as an indicator of subclinical atherosclerosis, was assessed using ultrasonography.

Results.

Patients with RA had higher body mass index, blood pressure, and triglyceride levels and were more often cigarette smokers compared to controls. SAE was decreased in RA patients compared to controls and was inversely related with age, smoking, blood pressure, vWF, sVCAM-1, high sensitivity C-reactive protein, and IMT. Presence of RA was independently related to SAE in multivariate linear regression analysis. SAE was inversely related with the Health Assessment Questionnaire score. No correlation was found between SAE and other disease activity markers and damage. IMT in patients and controls was not different.

Conclusion.

Small artery elasticity was decreased in patients with longstanding RA. The presence of RA was independently associated with SAE. Whereas IMT in patients with RA was not increased, we hypothesize that endothelial dysfunction, reflected by decreased SAE, is present prior to IMT thickening in these patients.
Clinical and Serological Hallmarks of Systemic Sclerosis Overlap Syndromes
Authors: PAKOZDI ANGELA , NIHTYANOVA SVETLANA , MOINZADEH PIA , ONG VOON H. , BLACK CAROL M. , DENTON CHRISTOPHER P.
Published: August 2011

Objective.

To determine the prevalence of systemic sclerosis (SSc) overlap syndrome and autoantibody profile in a large single-center cohort.

Methods.

SSc diagnoses, subsets, and autoantibody profiles were obtained from clinical records of patients attending the Centre for Rheumatology, Royal Free Hospital, between September 1999 and February 2007.

Results.

In total, 332 (20%) of 1700 patients with SSc had overlap syndrome. This comprised myositis (42.8%), rheumatoid arthritis (RA; 32%), Sjögren’s syndrome (SS; 16.8%), and systemic lupus erythematosus (SLE; 8.4%). Antinuclear antibody was positive in 96.6% of patients. Anticentromere antibody (ACA) was exclusively present in limited cutaneous SSc (lcSSc) overlap cases (22%), and more common in SSc/SS overlap (44.7%), whereas no difference was found in the prevalence of Scl-70 autoantibody between lcSSc and diffuse cutaneous SSc overlap groups. U1RNP was more frequent in SSc/SLE (44%), while Ro antibody was more likely to be found in SSc/SS (29.8%). ACA was absent and anti-Scl-70 was infrequent in SSc/myositis; polymyositis-scleroderma antibody was more frequent in this group (33.1%). About 50% of patients had raised rheumatoid factor (RF), with no difference between overlap groups irrespective of RF titer. In contrast, anticyclic citrullinated peptide antibody was more frequent in patients with RA features.

Conclusion.

About one-fifth of SSc cases had overlap features. There were distinct serological features that may predict specific clinical presentation and disease course.
Cystatin C, Renal Function, and Atherosclerosis in Rheumatoid Arthritis
Authors: LERTNAWAPAN RATCHAYA , BIAN AIHUA , RHO YOUNG HEE , KAWAI VIVIAN K. , RAGGI PAOLO , OESER ANNETTE , SOLUS JOSEPH F. , GEBRETSADIK TEBEB , SHINTANI AYUMI , STEIN C. MICHAEL
Published: August 2011

Objective.

We examined the hypothesis that cystatin C, a novel marker of renal function, is elevated in rheumatoid arthritis (RA) and is associated with inflammation and coronary atherosclerosis.

Methods.

We measured serum cystatin C, creatinine, tumor necrosis factor-α and interleukin 6 concentrations, coronary artery calcium score (CACS), and Modified Diet in Renal Disease estimated glomerular filtration rate in 167 patients with RA and 91 controls.

Results.

Cystatin C was higher in RA patients [median (IQR) 1.16 (0.99–1.35) mg/l] than controls [1.01 (0.90–1.19) mg/l; p < 0.001] and correlated positively with erythrocyte sedimentation rate (p < 0.001), C-reactive protein (p = 0.01), 28-joint Disease Activity Score (p = 0.006), and Framingham risk score (FRS; p = 0.02). Cystatin C was correlated with CACS (p < 0.001) in RA, but this was not significant after adjustment for age, race, sex, and FRS (p = 0.44).

Conclusion.

Cystatin C concentrations are higher in RA than controls and may reflect inflammation and undetected subclinical renal dysfunction. Cystatin C provides information regarding the risk of atherosclerosis in RA, but this is not independent of the information provided by conventional cardiovascular risk factors.
Interpretation of microtremor 2D array data using Rayleigh and Love waves: the case study of Bevagna (central Italy)
Authors: Puglia R. , Tokeshi K. , Picozzi M. , D’Alema E. , Parolai S. , Foti S.
Published: August 2011

In the last decades, geophysicists and seismologists have focused their attention on the inversion of empirical surface‐waves’ dispersion curves from microtremor measurements for estimating the S‐wave velocity structure at a site. This procedure allows a fast and convenient investigation without strong active sources, which are difficult to deploy especially in urban areas.

In this study we report on a 2D seismic noise array experiment carried out at Bevagna (central Italy) near the station BVG of the Italian Accelerometric Network (RAN). The site was investigated within the DPC‐INGV S4 Project (2007‐2009). The Rayleigh‐ and Love‐waves dispersion characteristics were estimated using different methods. The inversion of the dispersion curves was then performed independently, obtaining two estimations for the S‐wave velocity profiles. The results of cross‐hole logging near the seismic station are used for a comparison.

The shear‐wave velocity profiles estimated by microtremor analyses range up to 150 m depth. The two independent procedures provide consistent shear‐wave velocity profiles for the shallow part of the model (20–30 m in depth) in agreement with the results of the cross‐hole logging. Some problems arise between 30–40 m in depth in the profile estimated by surface waves. In this range cross‐hole logging evidences an inversion of the S‐wave velocity. Although the cross‐hole logging stops at 40 m of depth, we are confident about the results provided by the Rayleigh‐wave analysis below 40–50 m. This case study suggests that greater efforts should be devoted to exploit the potential of a coupled analysis of Rayleigh and Love waves from microtremor array measurements.
Recurrent Lower Gastrointestinal Bleeding Due to Angiodysplasia in the Rectum: Endoscopic Treatment with Heater Probe
Authors: Bas Koray , Besim Hasan
Published: August 2011

Lower gastrointestinal bleeding due to vascular abnormalities is commonly found in the elderly and on the right side of the colon. Such lesions are still difficult to diagnose and manage. We report a case with recurrent and massive lower gastrointestinal bleeding due to angiodysplasia at an unusual age and localization, which was diagnosed and treated endoscopically.
Balayage of Semi-Dirichlet Forms
Authors: Hu Ze-Chun , Sun Wei
Published: August 2011

In this paper we study the balayage of semi-Dirichlet forms. We present new results on balayaged functions and balayagedmeasures of semi-Dirichlet forms. Some of the results are new even in the Dirichlet forms setting.
Holomorphic Mappings between Domains in ℂ2
Authors: Shafikov Rasul , Verma Kaushal
Published: August 2011

An extension theorem for holomorphic mappings between two domains in ℂ2is proved under purely local hypotheses.
Diagnóstico das bibliotecas escolares da rede estadual de ensino de Belo Horizonte – MG: a situação dos acervos
Authors: Abreu Vera Lúcia Furst Gonçalves , Campello Bernadete Santos , Vianna Márcia Milton , Carvalho Maria da Conceição , Andrade Maria Eugênia Albino , Caldeira Paulo da Terra
Published: August 2011

Apresenta resultados de pesquisa sobre o acervo de bibliotecas escolares da rede estadual de ensino de Belo Horizonte – MG, na perspectiva da quantidade de materiais disponíveis para uso dos alunos. Os dados, obtidos por questionário respondido pelos responsáveis por 63 bibliotecas, mostram que a média de itens por aluno é de 3,56. Poucas bibliotecas possuem computadores ligados à Internet, e em apenas uma escola os computadores são utilizados pelos alunos. Na maioria das bibliotecas, os alunos costumam ser encaminhado, quando necessário, para outras bibliotecas: de escolas vizinhas, de universidades e, principalmente, para a biblioteca pública. A maioria dos responsáveis pelas bibliotecas considera seus acervos regulares ou bons, e boa a utilização pelos usuários.
Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2
Authors: Chylek P. , Li J. , Dubey M. K. , Wang M. , Lesins G.
Published: August 2011

Abstract. We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940–1970 period of substantial cooling. The addition of the land-vegetation model and the terrestrial and oceanic interactive carbon cycle to the coupled atmosphere-ocean model improves the agreement with observations from 1900–1970, however, it increases the overestimate of the post 1970 warming. In contrast the older generation coupled atmosphere-ocean general circulation models Canadian CanCM3 and NCAR/LANL CCSM3, used in the IPCC 2007 climate change assessment report, overestimate the rate of the 20th century Arctic warming by factor of two to three and they are unable to reproduce the observed 20th century Arctic climate variability.
Impact of the European Russia drought in 2010 on the Caspian Sea level
Authors: Arpe K. , Leroy S. A. G. , Lahijani H. , Khan V.
Published: August 2011

Abstract. The hydrological budgets of the Volga basin (VB) and the Caspian Sea (CS) have been established. The components of the water balance for the CS were calculated for the period 1993 to 2010 with emphasis on summer 2010 when a severe drought developed over European Russia. A drop in precipitation over the VB in July 2010 occurs simultaneously with a decrease in evaporation for the same area, an increase of evaporation over the CS itself and a drop of the Caspian Sea Level (CSL). The drop in the precipitation over the VB cannot have led to an instantaneous drop of the CSL because the precipitated water needs some months to reach the CS. The delay is estimated to be 1 to 3 months for excessive precipitation in summer, longer for other cases. However, the evaporation over the CS itself is considered to be responsible for a simultaneous drop of the CSL from July to September 2010. The impact on the CSL from the precipitation deficit over the VB occurs in the months following the drought. The water deficit from July to September 2010 calculated from the anomalous precipitation minus evaporation over the VB would decrease the CSL by 22 cm, of which only 2 cm had been observed until end of September (observed Volga River discharge anomaly), 7 cm from October to the end of 2010 and another 5 cm to the end of May 2011. From October 2010 to February 2011 excessive precipitation occurred over the Volga basin, equivalent to an increase of the CSL of 7 cm which might just compensate the 7 cm of the remaining deficit from the summer drought. A deficit of water took however already place in the months before July 2010. In previous studies the precipitation over the VB has been identified as the main cause for CSL changes, but here from a 10 cm drop from beginning of July to end of September, 6 cm can be directly assigned to the enhanced evaporation over the CS itself and 2 cm due to reduced precipitation over the CS. Further periods with strong changes of the CSL are investigated as well which provide some estimates concerning the accuracy of the analysis data. The investigation was possible due to the new ECMWF interim reanalysis data which are used to provide data also for sensitive quantities like surface evaporation and precipitation. The comparison with independent data and the consistency between such data for calculating the water budget over the CS gives a high confidence in the quality of the data used. This investigation provides some scope for making forecasts of the CSL few months ahead to allow for mitigating societal impacts.
Should the UK be nominating More World Heritage Sites?
Authors: Norman Kirsty
Published: August 2011

This article is an account of a challenge issued in a seminar at the Institute of Archaeology, UCL in October 2010: it looks at the changing political and economic context within which the UK nominates World Heritage Sites, and questions whether – practically, and even ethically – we should be continuing to submit sites to the World Heritage Committee for inclusion on the World Heritage List.Over the last few years, my work has provided me a with series of insights into particular aspects of the World Heritage question: an analysis of the Tentative List Review process for English Heritage, and of the responses to the “World Heritage for the Nation” consultation for the Department for Culture, Media and Sport (DCMS), followed by a year of work on the UK’s latest World Heritage Site nomination of the Twin Monastery of Wearmouth and Jarrow, and on the management plan for the World Heritage Site of Ancient Merv (Turkmenistan).  This cocktail of World Heritage research and practice has given me, like many, a respect for the concept and the ideals behind it, but doubts about the implementation. My conclusions are personal and partial, and if they generate further discussion I will have achieved my aim.
On the Transcendental Entire Solutions of a Certain Differential Equation and Fixed Points
Authors: Shen Tiantian , Lü Weiran , Chu Guangxue
Published: August 2011

We will first show that the following differential equation F(k)−z=eα(F−z) has transcendental entire solutions, where F=fn and α is an entire function, which improve what we have known and answer an open question raised in the work of Zhang and Yang (2009). And then, the examples are discussed.
Morphology and Release Kinetics of Protein-Loaded Porous Poly(L-Lactic Acid) Spheres Prepared by Freeze-Drying Technique
Authors: Sasaki Takashi , Tanaka Kazuki , Morino Daisuke , Sakurai Kensuke
Published: August 2011

Freeze-drying a biodegradable polymer, poly(L-lactic acid) (PLLA), from 1,4-dioxane solutions provided very porous spherical particles of ca. 3 mm in radius with specific surface area of 8–13 m2 g−1. The surface of the particle was found to be less porous compared with its interior. To apply the freeze-dried PLLA (FDPLLA) to drug delivery system, its morphology and drug releasing kinetics were investigated, bovine serum albumin (BSA) being used as a model drug compound. Immersion of FDPLLA into a BSA aqueous solution gave BSA-loaded FDPLLA, where mass fraction of the adsorbed BSA reached up to 79%. Time-dependent release profile of BSA in water suggested a two-step mechanism: (1) very rapid release of BSA deposited on and near the particle surface, which results in an initial burst, and (2) leaching of BSA from the interior of the particle by the diffusion process. It was suggested that the latter process is largely governed by the surface porosity. The porosity of both the interior and surface was found to decrease remarkably as the concentration of the original PLLA/1,4-dioxane solution increases, C0. Thus, C0 is a key parameter that controls the loading and releasing of BSA.
Generalized Derivations and Left Ideals in Prime and Semiprime Rings
Authors: Dhara Basudeb , Pattanayak Atanu
Published: August 2011

Let R
be an associative ring,
λ a nonzero left ideal of
R, d:R→R a derivation and
G:R→R a generalized derivation. In this paper, we study the following situations in prime and semiprime rings: (1) G(x∘y)=a(xy±yx); (2) G[x,y]=a(xy±yx); (3) d(x)∘d(y)=a(xy±yx); for all x,y∈λ and
a∈{0,1,-1}.
Power Control Methods for Improving Spatial Reuse in TDMA-Based Wireless Mesh Networks
Authors: Hasegawa Go , Hidekuma Toshiaki , Sasabe Masahiro , Nakano Hirotaka
Published: August 2011

Wireless Mesh Networks (WMNs) have attracted a great deal of interest in recent years as a cost-effective method to provide a wireless network infrastructure. To accommodate various types of application traffic in WMNs, improvement of network capacity is one of the most critical issues. The efficiency of wireless network resource utilization decreases due to radio interference when multiple transmissions occur simultaneously in an interference region. To resolve this problem, we focus on the transmission power control of mesh nodes. We expect to improve spatial reuse by applying power control because this decreases radio interference between wireless links. In this paper, we propose power control methods of mesh nodes for improving spatial reuse in TDMA-based wireless mesh networks. We first propose two types of power control methods, which employ a simple threshold-based mechanism. Furthermore, we develop an additional method that suppresses the unnecessary increase in path length associated with limiting the increase in the hop count to the nearby mesh nodes. Numerical evaluation results reveal that the proposed method decreases the frame length by up to 27% with non sensitive parameter setting.
Degradation Models and Analyses
Authors: Meeker William , Hong Yili , Escobar Luis
Published: August 2011

For products/systems requiring high reliability or availability, reliability assessment and maintenance actions are often needed in a timely manner. For these systems/products, information on system state and performance can be collected over the system's operating time, providing what is known as degradation data. With appropriate models and data analysis techniques, degradation data are converted to system reliability information and this information is useful for short and long‐term reliability assessment and for planning maintenance actions. This article provides a review of degradation data models and methods that have been used successfully in this area. Commonly used methods for analyzing degradation data, general path models and stochastic models, are described in detail. Models and methods for analyzing data from accelerated degradation tests and accelerated destructive degradation tests are also introduced. Dynamic condition monitoring based on degradation data is covered. Examples are used to illustrate the models and methods covered in this article. The conclusion provides a discussion of test planning, software implementation and the future of degradation data analysis.
Statistical Models for Damage Accumulation
Authors: Castillo Enrique , Fernández‐Canteli Alfonso
Published: August 2011

As an initiation to the damage accumulation problem, different damage measures are presented, including a discussion of the properties that should be expected from these measures when not only mean values but uncertainties are required. Next, the role played by the Buckingham theorem and similarity and self‐similarity conditions in the process of building models is justified. Special attention is devoted to dynamic system based models, the assumptions of which are described and discussed together with the corresponding implications on the resulting models. Since building models based on their expected properties more than on artificial assumptions are defended, the technique of functional equations, a very innovative and powerful mathematical tool, is used to represent these properties and to obtain the resulting models. An illustration is given to derive the S‐N models that allow the effect of stress level and range on the fatigue life to be considered and the associated uncertainty to be defined. Similar procedures are applied to the derivation of crack growth and crack growth rate models. Due to the practical importance of the load history, the rainflow counting technique is described using the stress level to define the rainflow matrix. Finally, an example of application and final remarks are provided.
Step‐Stress Testing with Multiple Samples: The Exponential Case
Authors: Balakrishnan N. , Kamps Udo
Published: August 2011

Step‐stress models are descriptions of special experiments in the field of accelerated life testing, where the test units are exposed to stress levels that change at intermediate time points during the experiment. The goal is to develop inference for the mean lifetime at each stress level. The time points of stress level change can either be fixed or random. Furthermore, the experiment can be terminated when a certain number of failures is reached or at a pre‐specified time point. These alternative assumptions of the type of the experiment lead to alternative models. Usually the step‐stress models are based on a single experiment. We develop inference for step stress models designed for multiple samples. The stress levels are the same applied to all samples but the duration of exposure under each stress level can vary among the experiments.

The likelihood inference is then discussed in detail for the exponential case and different simple step‐stress experiments.
Pinch Technology
Authors: Heck Ludwig , Poth Nikolaus , Soni Vipasha
Published: August 2011

The article contains sections titled:

1.

Introduction

2.

Composite Curves and Energy Targets

3.

Pinch Principle

4.

Utility Optimization and Energy‐Capital Trade‐off

5.

Process Modifications

6.

Energy Efficient Process Design

7.

Process Optimization

8.

Perspectives
Eulerian Path and Tour Problems
Authors: Mohan Srimathy
Published: August 2011

A fundamental problem in arc or edge routing is determining an Eulerian path or tour in the underlying graph. An Eulerian tour is a traversal that visits every edge of the graph exactly once and every node at least once. This paper presents the history of the Eulerian tour problem; the main algorithms to find Eulerian tours in directed, undirected, and mixed Eulerian graphs; and the ongoing research topics.
Preparative Uses of Organoselenium and Organotellurium Compounds
Authors: Nomoto Akihiro , Ogawa Akiya
Published: August 2011

Organoselenium and organotellurium compounds are important not only for synthetic organic chemistry but also materials science or pharmacology. Attentions are mainly focused on the reactivity of selenium and tellurium reagents on electrophilic, nucleophilic, radical, transition‐metal‐catalyzed, reduction, and oxidation reaction. Organoselenium and organotellurium have unique reactivities, and their radical reactions and the transition‐metal‐catalyzed reactions have been developed recently. This chapter deals with the recent advances in the preparative uses of organoselenium and organotellurium compounds.
Controlled Delivery of Gentamicin Antibiotic from Bioactive Electrospun Polylactide‐Based Ultrathin Fibers
Authors: Torres‐Giner Sergio , Martinez‐Abad Antonio , Gimeno‐Alcañiz Jose V. , Ocio Maria J. , Lagaron Jose M.
Published: August 2011

The purpose of this study was to generate ultrathin fibers based on polylactide (PLA) biopolyester with antimicrobial controlled release capacity to treat bacterial infections. To achieve this objective, gentamicin antibiotic was encapsulated into pure PLA fibers, a blend of PLA–collagen and coaxial fibers containing a skin of PLA and a core of collagen using the electrospinning technique. The morphology of the gentamicin‐loaded fibers and the antibiotic distribution within the fibers were examined by SEM and TEM. The drug delivery profile of the different electrospun fibers was analyzed using a spectrophotometric method. The performance for treating common possible post‐surgical infections was investigated against Staphylococcus epidermis, Pseudomonas aeruginosa and Escherichia coli. The morphology of the electrospun fibers as well as the hydrophilicity of the polymer blends ultimately determined the antibiotic release characteristics. The results indicated that such drug‐loaded fibers can serve as advanced delivery platforms with strong and timing controllable antibacterial properties.
Thienoacene‐Based Organic Semiconductors
Authors: Takimiya Kazuo , Shinamura Shoji , Osaka Itaru , Miyazaki Eigo
Published: August 2011

Thienoacenes consist of fused thiophene rings in a ladder‐type molecular structure and have been intensively studied as potential organic semiconductors for organic field‐effect transistors (OFETs) in the last decade. They are reviewed here. Despite their simple and similar molecular structures, the hitherto reported properties of thienoacene‐based OFETs are rather diverse. This Review focuses on four classes of thienoacenes, which are classified in terms of their chemical structures, and elucidates the molecular electronic structure of each class. The packing structures of thienoacenes and the thus‐estimated solid‐state electronic structures are correlated to their carrier transport properties in OFET devices. With this perspective of the molecular structures of thienoacenes and their carrier transport properties in OFET devices, the structure–property relationships in thienoacene‐based organic semiconductors are discussed. The discussion provides insight into new molecular design strategies for the development of superior organic semiconductors.
Extracting the optimal sampling frequency of applications using spectral analysis
Authors: Casas Marc , Servat Harald , Badia Rosa M. , Labarta Jesús
Published: August 2011

The research community have agreed on several applications as benchmarks to evaluate the adequateness of architectures and high performance computing infrastructures. The performance of these benchmarks is used to determine the weaknesses and strengths of novel designs. Therefore, the performance evaluation of benchmarks is a key factor in the process of designing new architectures. In this paper, we propose a new method based on spectral analysis that allows to perform an automatic analysis of benchmarks' executions. The output of the new method is a representative segment of the benchmarks' executions. Given the nature of the method, the optimal sampling interval length of applications is obtained. This method complements and improves existing techniques focused on the reduction of the application's instruction execution stream of sequential benchmarks and enables the extraction of significant performance information of parallel benchmarks without executing the whole application. The results obtained with the SPEC CPU2000 and the NAS Parallel Benchmarks demonstrate the efficiency and benefits of the approach. Copyright © 2011 John Wiley & Sons, Ltd.
Thermal characteristics of oleochemical carbonate binary mixtures for potential latent heat storage
Authors: Kenar James A.
Published: August 2011

The thermal properties for binary mixtures at various weight fraction ratios between dodecyl carbonate (1a), tetradecyl carbonate (1b), hexadecyl carbonate (1c), and octadecyl carbonate (1d) were examined by DSC at 0.5, 1.0, and 5.0°C/min. At 5°C/min sharp well defined phase transitions were observed at 80:20, 88:12, and 90:10, for 1a:(1b, 1c, and 1d), respectively, at 74:26 and 80:20 for 1b:(1c, and 1d), respectively, and at 82.5:17 for 1c:1d. The melting and solidification temperatures for these mixtures ranged between 12–37°C (melting) and 8–34°C (solidification). The latent heat of melting and solidification determined for the binary carbonate mixtures ranged between 135 and 175 J/g. At 0.5 or 1.0°C/min, mixtures of 1a:(1b, 1c, and 1d) and 1b:1d melted and solidified similarly when run at 5°C/min while the melting curves for 1b:1c and 1c:1d were not as well defined. These carbonate mixtures extend the thermal properties of the pure oleochemical carbonates and compliment other biobased phase change materials (PCMs) substances such as fatty acids, esters, and alcohols and may provide useful biobased alternatives to paraffin wax and salt hydrate PCM currently dominating the market.
Multimodal biophotonic workstation for live cell analysis
Authors: Esseling Michael , Kemper Björn , Antkowiak Maciej , Stevenson David J. , Chaudet Lionel , Neil Mark A. A. , French Paul W. , von Bally Gert , Dholakia Kishan , Denz Cornelia
Published: August 2011

A reliable description and quantification of the complex physiology and reactions of living cells requires a multimodal analysis with various measurement techniques. We have investigated the integration of different techniques into a biophotonic workstation that can provide biological researchers with these capabilities. The combination of a micromanipulation tool with three different imaging principles is accomplished in a single inverted microscope which makes the results from all the techniques directly comparable. Chinese Hamster Ovary (CHO) cells were manipulated by optical tweezers while the feedback was directly analyzed by fluorescence lifetime imaging, digital holographic microscopy and dynamic phase‐contrast microscopy. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessment of summer extremes and climate variability over the north‐east of North America as simulated by the Canadian Regional Climate Model
Authors: Roy Philippe , Gachon Philippe , Laprise René
Published: August 2011

The present study focuses on the evaluation and comparison of the ability of two versions of the Canadian Regional Climate Model (CRCM) driven by re‐analyses (NCEP–NCAR) to reproduce the observed extremes and climate variability in summer (1961–1990). The analysed variables are daily precipitation, minimum and maximum temperatures over three regions located in north‐eastern North America that are characterized by different topography and observation density. The validation has been performed with multiple climate extreme indices characterizing the frequency, intensity and duration of precipitation and temperature events. The assessment of the ability of the CRCM is done through an in‐depth analysis of the statistical distribution, performance scores and interannual variability of extreme indices. The reference database has been constructed by kriging the daily observed data from local meteorological stations onto the CRCM 45‐km grid. The vast majority of results over the three regions show that, with respect to the previous (i.e. 3.7.1) CRCM version, the latest version (4.1.1) improves in general the simulated extreme events. In particular, the intensity of extreme hot summer temperature, diurnal temperature range, wet days occurrence, seasonal dry spell, and to a lesser extent extreme cold summer temperature and heavy rainfall. The study suggests that improvements in the simulated extremes in the latest version are due mainly to the introduction of the new land surface scheme (CLASS 2.7), with a more sophisticated representation of the soil moisture content. This suggests the importance of surface processes parameterization as a potential cause of errors in simulated extremes. Copyright © 2011 Royal Meteorological Society
Extending Manley's Lancashire Plain Temperature Record: 1753–2007
Authors: Gormally A. M. , MacKenzie A. R. , Tych W.
Published: August 2011

Before Gordon Manley began work on his famous Central England Temperature (CET) record, he constructed an instrumental temperature record for the Lancashire Plain (LP), covering 1753–1945. We describe the construction of the LP series, and discuss strategies for its extension to the present day. We analyse the relationship between the LP and the Central England Temperature (CET) record in order to assess the value of continuing the LP. Three strategies for extending the LP have been considered: replicating the original methodology Manley used to construct the LP (option 1), using linear regression on archived station data to bring the extended record ‘in line’ with the original LP (option 2), and using the CET to predict the LP (option 3). In extending the LP, the station at Morecambe (Met Office station number 16851) was found to be particularly important. Our analysis highlights the importance of maintaining long‐running records at those stations, such as Morecambe, that are representative of a wider region. All three options were successfully extended to the present, providing similar results. The three extended series resulted in annual mean differences of 0.23, 0.26, and 0.29 °C below the CET, respectively. Both options 1 and 2 appear to provide a legitimate extension of the LP that is independent of the CET. Owing to uncertainties in the replication of Manley's methodology, option 2 was used in our final reconstruction of the LP to 2007. The final extension was found to be significantly correlated to (r2 = 0.912), and statistically indistinguishable from, the CET (Student's t‐test, p = 1). Anomalies between the two series (CET–LP) resulted in a frequency distribution with mean of 0.26 °C, and relative standard deviation of 60%, showing that, although closely correlated, there is significant inter‐annual variability in the bias between the datasets. Copyright © 2011 Royal Meteorological Society
Chronic Maxillary Sinusitis in Medieval Sigtuna, Sweden: A Study of Sinus Health and Effects on Bone Preservation
Authors: Sundman E. A. , Kjellström A.
Published: August 2011

Frequencies of maxillary sinusitis in the population of the medieval town Sigtuna, Sweden, were examined. The first aim was to explore the occurrence of sinus conditions in this urban population, and the second was to investigate the effects of preservation in relation to these changes. The skeletal sample consisted of 274 adolescent and adult individuals buried ca 970–1530 AD. The maxillary sinuses were examined for different types of skeletal change related to sinusitis. The severity and location of these changes were recorded, together with the preservation of the sinus. When the diagnostic criteria for bone preservation from previous studies was used, i.e. the preservation of at least one complete antral floor, the results showed that 97.7% (n = 157) of the individuals were affected, with older individuals showing more severe bone changes. In the entire (i.e. more fragmented) sample, 94.5% (n = 259) showed signs of sinusitis. Again, older individuals showed more severe bone changes, and males were more frequently affected. Also, an increased frequency over time was found. The maxillae were subdivided into groups of bone preservation, and the results showed that there was a significant relation between preservation and the registered presence and severity of sinusitis. The results may be used as a cautionary note against investigating the occurrence of maxillary sinusitis without considering the skeletal preservation factor. There was no correlation between preservation and sex or age groups. This suggests that the differences between younger and older and male and female were not a result of preservation alone and could be considered as trustworthy. Copyright © 2011 John Wiley & Sons, Ltd.
Exploring Risk Dimensions in the Indian Software Industry
Authors: Sharma Arpita , Sengupta Santoshi , Gupta Aayushi
Published: August 2011

The success of software projects is quite subjective in nature and is fettered by many risks, the perception of which varies from individual to individual and largely depends on the demographic characteristics of the executives and even the characteristics of the project. This study aims to identify and gauge the software risk dimensions and analyze the differences of perception among executives toward software risks. The contributions of this study untangle the issues underlying risks in the software industry and associates these issues with the perception of the “human” factor present in the industry.
Exploring PMOs through Community of Practice Theory
Authors: Aubry Monique , Müller Ralf , Glückler Johannes
Published: August 2011

This article explores project management offices (PMOs) through community of practice theory. Preliminary results from a national health care case study are used to confirm the legitimacy of this approach. Today's knowledge-based economy calls for mechanisms to share knowledge. The issue of making more with less is at stake in order to reuse good practices, support innovative practice, and prevent the reinvention of the wheel. Members of these communities are at the heart of the learning process. The originality of this research is that it sheds light on PMOs in a new theoretical perspective within the field of knowledge management.
Translation and Convergence in Projects: An Organizational Perspective on Project Success
Authors: Alderman Neil , Ivory Chris
Published: August 2011

A range of theories (actor-network theory, multinodality, and sense making) are drawn together into a single model of project management processes in order to discuss project success and failure. It is argued that success and failure can be characterized in terms of a continuum between project convergence and divergence. The causes of divergence and convergence are discussed with reference to the above theories using four illustrative case studies.
Charge detection in a bilayer graphene quantum dot
Authors: Fringes Stefan , Volk Christian , Norda Caroline , Terrés Bernat , Dauber Jan , Engels Stephan , Trellenkamp Stefan , Stampfer Christoph
Published: August 2011

We show measurements on a bilayer graphene quantum dot (QD) with an integrated charge detector. The focus lies on enabling charge detection with a 30 nm wide bilayer graphene nanoribbon located approximately 35 nm next to a bilayer graphene QD with an island diameter of about 100 nm. Local resonances in the nanoribbon can be successfully used to detect individual charging events in the dot even in regimes where the QD Coulomb peaks cannot be measured by conventional techniques.

magnified image

False color atomic force microscope image of the investigated device.
Raman spectroscopy of PbTe/CdTe nanocrystals
Authors: Tschirner Norman , Lange Holger , Lambert Karel , Hens Zeger , Thomsen Christian
Published: August 2011

We studied the evolution of Raman signals stemming from colloidal PbTe/CdTe nanocrystals (NCs). The NCs were grown using the cation exchange method and samples having different amounts of CdTe as shell material were investigated. The observed Raman bands are correlated to pure tellurium modes and after introduction of CdTe its longitudinal optical (LO) mode becomes also visible. The tellurium modes' intensity rapidly decreases after cationic exchange due to the chemical bonding of the vacant tellurium atoms.
Stepped discontinuity in a quantum well as a spin flipper
Authors: Dargys A.
Published: August 2011

Electron reflection off and transmission through a stepped discontinuity in quantum well (QW), for example, due difference in spin–orbit (SO) interaction constants, effective masses, or potential step, is analyzed in a general case. Correct boundary conditions at the discontinuity are taken into account. It was found that spin flipping of the transmitted beam can be as high as 100%. A simple formula that relates the transmitted spin polarization and SO interaction constants on both sides of the discontinuity is presented and a relevant experimental set‐up is proposed to measure SO interaction constants using a homobarrier in the QW.
Influence of randomness and retardation on the FMR‐linewidth
Authors: Bose Thomas , Trimper Steffen
Published: August 2011

The theory predicts that the spin‐wave lifetime τL and the linewidth of ferromagnetic resonance ΔB can be governed by random fields and spatial memory. To that aim the effective field around which the magnetic moments perform a precession is superimposed by a stochastic time dependent magnetic field with finite correlation time. The magnetization dynamics is altered by inclusion of a spatial memory effect monitoring a non‐local interaction of size ξ. The underlying Landau–Lifshitz–Gilbert equation (LLG) is modified accordingly. The stochastic LLG is equivalent to a Fokker–Planck equation which enables to calculate the mean values of the magnetization vector. Within the spin‐wave approximation we present an analytical solution for the excitation energy and its damping. The lifetime and the linewidth are analyzed depending on the strength of the random field D and its correlation time τc as well as the retardation strength Γ0 and the size ξ. Whereas τL decreases with increasing D, retardation strength Γ0 and τc, the lifetime is enhanced for growing width ξ of the spatial retardation kernel. In the same manner we calculate the experimentally measurable linewidth ΔB is increased strongly when the correlation time τc ranges in the nanosecond interval.
Magnetic reorientation in a ferrimagnetic monolayer
Authors: Ilkovič V. , Kecer J.
Published: August 2011

The Green function theory is used to study theoretically the magnetic reorientation phase transition (MRPT) in a two‐sublattice ferrimagnetic monolayer, with spin SA and SB at the sublattice A and B sites, respectively. The result is that MRPT in the sublattices A and B occurs at different reorientation temperatures. We can assume that presented model confirms the possibility of two magnetic phases in ferrimagnetic systems.
Synthesis, electrical transport and Mössbauer spectroscopy study of the layered iron tellurides Fe1.1−xNixTe
Authors: Janaki J. , Govindaraj R. , Kumary T. Geetha , Mani Awadhesh , Rao G.V. Narasimha , Bharathi A.
Published: August 2011

The synthesis, characterization, electrical transport and Mössbauer spectroscopy study of the layered iron telluride series Fe1.1−xNixTe (x = 0, 0.02, 0.04, 0.08, 0.12) have been carried out. X‐ray characterization studies show that the Ni substituted compounds exhibit the tetragonal PbO‐type structure similar to the pristine compound Fe1.1Te, but with a reduction of the unit cell volume. Micro‐structural analysis using combined scanning electron microscopy and energy‐dispersive X‐ray spectroscopy reveal plate like morphology and fine grain sizes. The Ni contents are in agreement with the nominal composition. Mössbauer spectroscopic studies indicate significant changes in the local symmetry at the iron site upon substitution, including a more symmetric FeTe4 tetrahedron. It is inferred from the resistivity study in the range 300–4.2 K that Ni substitution leads to the suppression of the first order phase transition observed in Fe1.1Te. However superconductivity is not observed in the substituted compounds unlike in the case of anionic doping reported earlier.
SPATIAL AND TEMPORAL CHANGES IN TOTAL SUSPENDED SEDIMENT CONCENTRATIONS IN AN OXBOW LAKE AFTER IMPLEMENTING AGRICULTURAL LANDSCAPE MANAGEMENT PRACTICES
Authors: Kröger R. , Dibble E. , Brandt J. B. , Fleming J. P. , Huenemann T. , Stubbs T. , Prevost J. D. , Tietjen T. , Littlejohn K. A. , Pierce S. C. , Spickard M.
Published: August 2011

The Wolf–Broad oxbow lake (417 ha) was evaluated by the Mississippi Department of Environmental Quality and included on the Mississippi 303(d) list of impaired waterbodies for total suspended solids (TSS). A study was undertaken for 2 years to evaluate and document changes to TSS (mg L−1) and overall lake turbidity (NTU) through best management practice implementation. These two objectives were analysed with routine monthly surface sampling events of turbidity (Eureka Manta 2, automated data sonde) as well as 20 random samples per sampling trip for TSS from June 2008 to June 2010. Results from a non‐parametric Kruskal–Wallis analysis indicated a significant month‐by‐year effect on turbidity and TSS (chi‐squared = 76.08, p = 0.001), but reach (chi‐squared = 2.45, p = 0.784) and depth by reach (chi‐squared = 2.44, p = 0.784) did not show significant effects on turbidity. There were no significant correlations between TSS concentrations and turbidity and 2 days and 7 days summed or mean rainfall for the duration of the evaluation. Spearman correlation analysis for TSS indicated significant correlations between TSS and mean two‐day (r2 = 0.62, p = 0.002) and seven‐day (r2 = 0.51, p = 0.014) wind speeds. All other variables used in the analysis did not show significant correlation with TSS ( p > 0.05). This suggests that wind conditions, rather than rainfall, predict the greatest variability in TSS and turbidity in Wolf Lake. These documented correlations between lake water column TSS, turbidity and wind highlight the difficulties of demonstrating success of management practices in the short temporal period between project initiation and completion. Unmanageable environmental conditions (wind speed and direction) and limited temporal monitoring scales (1 1/2 years post‐BMP implementation) limit the possibility of demonstrating successful water‐quality improvement within a 303(d) listed waterbody such as Wolf Lake. Copyright © 2011 John Wiley & Sons, Ltd.