bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral analysis of nonlocal regularization in two‐dimensional finite element models
Authors: Lu Xilin , Bardet Jean‐Pierre , Huang Maosong 
Published: January 2011

SUMMARYStrain‐softening in geomaterials often leads to ill‐posed boundary‐valued problems (BVP), which cannot be solved with finite element methods without introducing some kind of regularization such as nonlocal plasticity. Hereafter we propose to apply spectral analysis for testing the performance of nonlocal plasticity in regularizing ill‐posed BVP and producing mesh‐independent solutions when local plasticity usually fails. The spectral analysis consists of examining the eigenvalues and eigenvectors of the global tangential stiffness matrix of the incremental equilibrium equations. Based on spectral analysis, we propose a criterion for passing or failing the test of constitutive regularization in the context of BVP. If the eigenvalues of the tangential operator are all positive then the regularization succeeds, otherwise it fails and may not prevent artificial mesh‐dependent solutions from appearing. The approach is illustrated in the particular case of a biaxial compression with strain‐softening plasticity. In this particular case, local softening plasticity is found to produce negative eigenvalues in the tangential stiffness matrix, which indicates ill‐posed BVP. In contrast, nonlocal softening plasticity always produces positive eigenvalues, which regularizes ill‐posed BVP. The dominant eigenvectors, which generate localized deformation patterns, have a bandwidth independent of mesh size, provided that the mesh is fine enough to capture localization. These mesh‐independent eigenmodes explain why nonlocal plasticity produces numerical solutions that are mesh‐independent. Copyright © 2011 John Wiley & Sons, Ltd.
BUREAUCRATS AS PURCHASERS OF HEALTH SERVICES: LIMITATIONS OF THE PUBLIC SECTOR FOR CONTRACTING
Authors: Zaidi Shehla , Mayhew Susannah H , Palmer Natasha 
Published: January 2011

AbstractContracting out of health services increasingly involves a new role for governments as purchasers of services. To date, emphasis has been on contractual outcomes and the contracting process, which may benefit from improvements in developing countries, has been understudied. This article uses evidence from wide scale NGO contracting in Pakistan and examines the performance of government purchasers in managing the contracting process; draws comparisons with NGO managed contracting; and identifies purchaser skills needed for contracting NGOs. We found that the contracting process is complex and government purchasers struggled to manage the contracting process despite the provision of well‐designed contracts and guidelines. Weaknesses were seen in three areas: (i) poor capacity for managing tendering; (ii) weak public sector governance resulting in slow processes, low interest and rent seeking pressures; and (iii) mistrust between government and the NGO sector. In comparison parallel contracting ventures managed by large NGOs generally resulted in faster implementation, closer contractual relationships, drew wider participation of NGOs and often provided technical support. Our findings do not dilute the importance of government in contracting but front the case for an independent purchasing agency, for example an experienced NGO, to manage public sector contracts for community based services with the government role instead being one of larger oversight. Copyright © 2011 John Wiley & Sons, Ltd.
Down‐regulation of oestrogen receptor‐β associates with transcriptional co‐regulator PATZ1 delocalization in human testicular seminomas
Authors: Esposito Francesco , Boscia Francesca , Franco Renato , Tornincasa Mara , Fusco Alfredo , Kitazawa Sohei , Looijenga Leendert H , Chieffi Paolo 
Published: January 2011

AbstractOestrogen exposure has been linked to a risk for the development of testicular germ cell cancers. The effects of oestrogen are now known to be mediated by oestrogen receptor‐α (ERα) and ERβ subtypes, but only ERβ has been found in human germ cells of normal testis. However, its expression was markedly diminished in seminomas, embryonal cell carcinomas and mixed germ cell tumours, but remains high in teratomas. PATZ1 is a recently discovered zinc finger protein that, due to the presence of the POZ domain, acts as a transcriptional repressor affecting the basal activity of different promoters. We have previously described that PATZ1 plays a crucial role in normal male gametogenesis and that its up‐regulation and mislocalization could be associated with the development of testicular germ cell tumours. Here we show that ERβ interacts with PATZ1 in normal germ cells, while down‐regulation of ERβ associates with transcriptional co‐regulator PATZ1 delocalization in human testicular seminomas. In addition, we show that the translocation of PATZ1 from the cytoplasm into the nucleus is regulated by cAMP, which also induces increased expression and nuclear localization of ERβ, while this effect is counteracted by using the anti‐oestrogen ICI 182‐780. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Screening for trisomies in dichorionic twins by measurement of fetal nuchal translucency thickness according to the mixture model
Authors: Wright David , Syngelaki Argyro , Staboulidou Ismini , Jesus Cruz Jader de , Nicolaides Kypros H. 
Published: January 2011

AbstractObjectiveTo examine the distribution of fetal nuchal translucency (NT) thickness in dichorionic twins and investigate the effect of the correlation between NT measurements in each twin pair on the performance of screening for trisomies.MethodsThe distribution of fetal NT for crown–rump length (CRL) was examined in 5646 dichorionic twin pregnancies, including 103 with fetal trisomies 21, 18 or 13. The correlation in fetal NT in each euploid twin pregnancy was estimated.ResultsThe distribution of NT in both euploid and trisomic fetuses was consistent with the mixture model in singleton pregnancies. In the euploid pregnancies, there was a correlation in log NT measurements in each twin pair (r = 0.42, 95% CI: 0.39–0.45) and, after removal of the effect of the operator, this correlation was reduced to 0.34. Allowing for this correlation in risk assessment for trisomies had a major impact on the estimated patient‐specific risk but had little effect on the overall performance of screening.ConclusionsIn dichorionic twin pregnancies, the mixture model of distributions of NT can be applied as in singletons. In screening for trisomies, the correlation in NT measurements between the fetuses should be taken into account in the estimation of patient‐specific risks. Copyright © 2011 John Wiley & Sons, Ltd.
Current practices in determining amnionicity and chorionicity in multiple gestations
Authors: Wan Jennifer J. , Schrimmer David , Taché Véronique , Quinn Kristen , Lacoursiere D. Yvette , James Gina , Benirschke Kurt , Pretorius Dolores H. 
Published: January 2011

AbstractObjectiveTo evaluate the accuracy of amnionicity and chorionicity (A/C) diagnosis of referral physicians and a tertiary care center as compared to histopathologic diagnosis.MethodA retrospective study of 289 multi‐fetal gestations was performed comparing A/C diagnoses of referring physicians, a tertiary care center, and histopathology.ResultsTwo hundred and eighty‐nine multi‐fetal pregnancies were referred for evaluation; only 43.6% (126/289) carried an accurate diagnosis of A/C before tertiary care center evaluation. The tertiary care center accurately identified A/C in 94.8% (274/289) overall and 100% in first trimester twins and triplets. Referrals with an unspecified A/C diagnosis included 46.1% (113/245) twins and 64.1% (25/39) triplets.ConclusionAccurate diagnosis of A/C can be obtained by the early assessment of key sonographic findings. Referral providers are less accurate at determining A/C of mutifetal gestation when compared to a tertiary center, suggesting that an emphasis should be placed on enhancing these diagnostic skills in the general community or encouraging referral when diagnosis is ambiguous. Copyright © 2011 John Wiley & Sons, Ltd.
Greenhouse gas emissions associated with photovoltaic electricity from crystalline silicon modules under various energy supply options
Authors: Reich N.H. , Alsema E.A. , van Sark W.G.J.H.M. , Turkenburg W.C. , Sinke W.C. 
Published: January 2011

AbstractThe direct and indirect emissions associated with photovoltaic (PV) electricity generation are evaluated, focussing on greenhouse gas (GHG) emissions related to crystalline silicon (c‐Si) solar module production. Electricity supply technologies used in the entire PV production chain are found to be most influential. Emissions associated with only the electricity‐input in the production of PV vary as much as 0–200 g CO2‐eq per kWh electricity generated by PV. This wide range results because of specific supply technologies one may assume to provide the electricity‐input in PV production, i.e., whether coal‐, gas‐, wind‐, or PV‐power facilities in the “background” provide the electricity supply for powering the entire PV production chain. The heat input in the entire PV production chain, for which mainly the combustion of natural gas is assumed, adds another ∼16 CO2‐eq/kWh. The GHG emissions directly attributed to c‐Si PV technology alone constitute only ∼1–2 g CO2‐eq/kWh. The difference in scale indicates the relevance of reporting “indirect” emissions due to energy input in PV production separately from “direct” emissions particular to PV technology. In this article, we also demonstrate the utilization of “direct” and “indirect” shares of emissions for the calculation of GHG emissions in simplified world electricity‐ and PV‐market development scenarios. Results underscore very large GHG mitigation realized by solar PV toward increasingly significant PV market shares. Copyright © 2011 John Wiley & Sons, Ltd.
Development of industrial high‐efficiency back‐contact czochralski‐silicon solar cells
Authors: Gee James M. , Kumar Prabhat , Howarth James , Schroeder Todd , Franklin Jeff , Dominguez Jason , Tanner David 
Published: January 2011

AbstractBack‐contact silicon solar cells feature high efficiencies, simpler module assembly, and improved aesthetics. The emitter wrap through (EWT) cell structure is particularly attractive for use with industrial processing (e.g., screen‐printed metallization) and common solar‐grade p‐type Si materials. We report development of a high‐efficiency EWT back‐contact cell using p‐type Cz silicon and only industrial processing techniques such as screen‐printed metallizations, diffusions, and PECVD. An efficiency of 19.0% has been achieved with large area (156‐mm pseudo‐square) cells. Detailed characterization and modeling have been performed to understand the optical and electrical losses, and these results were used to generate a roadmap to improve the efficiency to over 20%. Copyright © 2011 John Wiley & Sons, Ltd.
A genuine circular contact grid pattern for solar cells
Authors: Bissels G.M.M.W. , Asselbergs M.A.H. , Schermer J.J. , Haverkamp E.J. , Smeenk N.J. , Vlieg E. 
Published: January 2011

AbstractA model was developed for a genuine circular contact grid, based on the same principles that led to previously reported models for other contact grid types. The circular grid differs from the regular (radial) grid often applied to round solar cells, in that it has considerably less radial lines and many more concentric rings, to the effect that the rings now take on the role of fingers, while the lines serve as busbars. For a 16 mm2 n‐on‐p GaAs cell and irradiances ranging from 1 to 1000 suns, optimised grids of this new circular design were compared to equivalent radial, square and inverted square grids. Furthermore, in order to allow for a fair comparison of the different grid types, the previously reported radial grid model was modified to obtain additional freedom in design that is comparable to that of the other grid configurations. The circular grid turned out to suffer less power loss than a comparable radial grid up to a concentration ratio of 30. At higher concentration ratios, cells with a radial grid performed better, while comparable square and inverted square grids perform better over the entire range of concentration ratios. For GaAs cells serving as the bottom cell in a mechanical tandem, the effects of secondary shadowing were calculated for a range of translational and rotational misalignments, for the four patterns optimised for the case where the GaAs cell is effectively subjected to a concentration ratio of 500. The effects of translational misalignment varied little between the grids, but the rotational misalignment effects demonstrated the strength of the circular grid, since its shadowing loss hardly increases with increasing rotational misalignment angle, while those of the other three grid types quickly approach a doubling. When these secondary shadowing effects are taken into account, the circular grid can be the preferred pattern for the constituent cells of a mechanical stack, depending on the accuracy with which those cells can be rotationally aligned. Copyright © 2011 John Wiley & Sons, Ltd.
Internet epidemiology: healthy, susceptible, infected, quarantined, and recovered
Authors: Kondakci Suleyman , Dincer Cemali 
Published: January 2011

AbstractThis paper presents a recurrent epidemic model (REM) to explore the dynamics of Internet epidemiology through the phases of susceptibility to recovery. From both theoretical and practical standpoint, it has two main differences compared to the bare worm propagation modeling. In the first place, it defines a unique stochastic model of a general infection spread. In the second place, it models the recovery process as a stochastic queueing system, which accurately partitions diagnose, quarantine, disinfection and recovery processes and complements it as a recurrent failure‐repair management model, which is entirely unique. There still exists an open question to model propagation patterns of infections and accompanying recovery models needed for effectively managing the infected individuals. The REM model is a unique concept in determining the parameters for estimating the recovery efficiency of disrupted systems and for developing long‐term recovery strategies under different epidemic situations. Existing infection and worm propagation models can also be used in cooperation with REM in order to analyse necessary quarantine and recovery processes. REM can also be applied for the accurate classification of the phases in epidemic dynamics and the states of affected systems in general, and also be used as a guideline for developing stochastic simulations covering various types of systems with recurrent state dynamics in order to facilitate reliability analysis of the systems. Copyright © 2011 John Wiley & Sons, Ltd.
The Ageing of Silica Gels Affected by Hydrothermal Treatment
Authors: Lutz Wolfgang , Weber Manfred , Bertram Rainer , Kurzhals Rolf , Kryukova Galina 
Published: January 2011

AbstractCommercial silica gels of the pyrogenic and precipitated types were hydrothermally treated for 72 hours at temperatures between 90 °C and 210 °C in water of autogenous pressure. The samples were characterised by IR spectroscopy, water and nitrogen adsorption. Stability and sorption capacity run similarly. The more Q4 (Si(OSi)4) building units the framework of a silica gel contained, the lower was its sorption capacity. Sorption capacity increased with rising number of structural defects characterised by the presence of Q3 (Si(OSi)3OH) and Q2 (Si(OSi)2(OH)2) groups. Simultaneously, the hydrothermal stability of the silica material dropped off.
Crystal Structure of the Silicide Phosphide Gd4Co13(Si, P)9, the Isotypic Lanthanoid Cobalt Silicide Phosphides Ln4Co13(Si, P)9 (Ln = Sm, Tb, Dy, Ho, Er), and the Uranium Iron Phosphide U4Fe13P9
Authors: Jeitschko Wolfgang , Jakubowski‐Ripke Ursula , Albering Jörg 
Published: January 2011

AbstractThe title compounds crystallize with a new hexagonal structure type, which was determined from single‐crystal diffractometer data of Gd4Co13(Si, P)9: space group P$\bar{6}$m2, a = 1041.9(4) pm, c = 372.7(1) pm, Pearson symbol hP26. The structure was refined to a residual of R = 0.033 for 18 variable parameters and 190 structure factors. The silicon and phosphorus atoms (X) are located at three crystallographic positions with eight or nine metal neighbors forming capped trigonal prisms most likely with random occupancy. The gadolinium atoms occupy two sites, each with 6 X neighbors forming trigonal prisms. This coordination is augmented by 14 metal atoms (mostly cobalt atoms), thus increasing the coordination numbers of both gadolinium positions to 20. The four different cobalt atoms have 3, 4, or 5 X neighbors with 6 or 8 additional metal neighbors. The relative strengths of the chemical bonds correlate very well with the coordination numbers. The structure belongs to a large structural family with a metal to metalloid ratio of approximately 2:1, where all atoms are situated on two alternating mirror planes and most of the metalloid atoms (M, mainly silicon, phosphorus, and their homologues) with the coordination number 9 are situated in tricapped prisms of the metal atoms (R = large electropositive metals, mainly rare earth elements and actinoids; T = transition metals). It can be classified as the third member (n = 3) of a topological series R$_{(n-1)^2}$Tn(n+2)–2M$_{n^2}$, where the structures of WC and α‐UCr6P4 (LiCo6P4) are the members with n = 1 and n = 2, respectively.
Community Mobilization and Community‐Based Participatory Research to Prevent Youth Violence Among Asian and Immigrant Populations
Authors: Le Thao N. , Arifuku Isami , Vuong Linh , Tran Gianna , Lustig Deborah F. , Zimring Franklin 
Published: January 2011

AbstractMany community mobilization activities for youth violence prevention involve the researchers assisting communities in identifying, adapting, and/or tailoring evidence‐based programs to fit the community needs, population, and cultural and social contexts. This article describes a slightly different framework in which the collaborative research/evaluation project emerged from the community mobilization activities. As will be discussed, this collaborative, sustained partnership was possible in the context of the Center on Culture, Immigration and Youth Violence Prevention's (UC Berkeley ACE) community mobilization activities that brought the issue of youth violence, particularly among immigrant and minority populations, to the forefront of many of the community partners' agendas. The East Bay Asian Youth Center (EBAYC) was one of the partners that came to the table, which facilitated the community‐based engagement/mobilization. UC Berkeley ACE collaborated with EBAYC to evaluate an after‐school program and an alternative probation program serving a diverse youth and immigrant population, including African Americans, Asians, and Hispanics. This article describes UC Berkeley ACE's community mobilization activity and the collaborative partnership with EBAYC, discusses how the evaluations incorporated community‐based principles in design and practice, and presents some findings from the evaluations.
Communication of Genetic Information by Other Health Professionals: The Role of the Genetic Counsellor in Specialist Clinics
Authors: O'Shea Rosie , Murphy Anne Marie , Treacy Eileen , Lynch Sally Ann , Thirlaway Kathryn , Lambert Debby 
Published: January 2011

AbstractMany children with chronic genetic diseases are followed by specialty clinics that provide genetic information as part of the care. Health services restrictions in the Republic of Ireland (ROI) can make the wait for an appointment with a genetic counsellor long. We examined whether genetic information was being adequately understood when presented by medical, but non‐genetics staff to long term patients, using our national metabolic service as an example. The aim was to inform health professionals about the need or role of a genetic counsellor in a specialist setting. A questionnaire was used to assess knowledge among parents and patients affected by galactosaemia and Maple Syrup Urine Disease (MSUD). Twenty seven families with galactosemia and 10 with MSUD were interviewed in clinic. Comparative analysis showed significant differences in knowledge between parents of children with galactosemia and adult patients (p = 0.001) and between ethnicities (p > 0.05). While parents are well informed, the majority expressed a wish for more information about the condition and its transmission. Adult patients with galactosemia and parents from certain ethnic backgrounds could especially benefit from genetic counselling. This study highlights the need for a genetic counsellor in specialist clinics.
Mrs Janet Taylor's ‘Mariner's Calculator’: assessment and reassessment
Authors: CROUCHER JOHN S. , CROUCHER ROSALIND F. 
Published: January 2011

AbstractVanished from history is the story of the ‘Mariner's Calculator’, invented and patented at the Great Seal Patent Office, London, by Mrs Janet Taylor, in 1834. Dismissed by the Admiralty, it had no commercial future and only one instrument is known to remain in existence. The article traces the invention from its inception and provides relevant biographical details of its inventor. The authors then analyse the assessment by the Admiralty to determine if it was fair and outline the endeavour in 2004 to reassess the achievement by a reconstruction of the Mariner's Calculator from its original patent.
Influence of the dietary protein:lipid ratio and fish oil substitution on fatty acid composition and metabolism of Atlantic salmon (Salmo salar) reared at high water temperatures
Authors: Karalazos Vasileios , Bendiksen Eldar Å. , Dick James R. , Tocher Douglas R. , Gordon Bell John 
Published: January 2011

A factorial, two-way, experimental design was used for this 10-week nutritional trial, aiming to elucidate the interactive effects of decreasing dietary protein:lipid level and substitution of fish oil (FO) with rapeseed oil (RO) on tissue fatty acid (FA) composition and metabolism of large Atlantic salmon (Salmo salarL.) reared at high water temperatures (sub-optimal, summer temperatures: 11·6°C). The six experimental diets were isoenergetic and formulated to include either FO or RO (60 % of the added oil) at three dietary protein:lipid levels, specifically (1) 350 g/kg protein and 350 g/kg lipid, (2) 330 g/kg protein and 360 g/kg lipid, (3) 290 g/kg protein and 380 g/kg lipid. Final weight, specific growth rate and thermal growth coefficient were positively affected by the dietary RO inclusion at the expense of FO, while no significant effects were seen on growth due to the decreasing protein level. The oil source had a significant effect on muscle and liver FA composition. However, the changes in muscle and liver FA indicate selective utilisation or retention of individual FA and moderate reductions in tissue EPA and DHA. Pyloric caeca phospholipid FA composition was significantly affected by the two factors and, in some cases, significant interactions were also revealed. Liver and red muscle β-oxidation capacities were significantly increased due to RO inclusion, while an interactive effect of protein level and oil source was shown for white muscle β-oxidation capacity. The results could explain, at least partially, the better performance that was shown for the RO groups and the enhanced protein-sparing effect.