bluuebunny/crossref_metadata_2025 huggingface dataset:
Re‐examining ethnic differences in concerns, knowledge, and beliefs about Alzheimer's disease: results from a national sample
Authors: Ayalon Liat
Published: April 2013

Objective

This study aims to evaluate ethnic group differences in concerns, knowledge, and beliefs about Alzheimer's disease (AD) in three ethnic groups of older adults (White, Latino, and Black).

Methods

The Health and Retirement Study is a US national representative study of older adults over the age of 50 years and their spouse of any age. The study is based on the 2010 wave.

Results

Analysis is based on data from 939 White, 120 Latino, and 171 Black respondents who completed a special module about AD concerns, knowledge, and beliefs. There were significant ethnic differences on 7 of 13 items. However, after the adjustment for education, gender, age, having a family member with AD, depressive symptoms, and medical comorbidity, only four items showed significant ethnic group differences; relative to White respondents, Black respondents were less likely to report that having a parent or a sibling with AD increases the chance of developing AD and that genetics was an important risk for AD. In addition, relative to White respondents, both Black and Latino respondents were more likely to perceive stress as a potential risk for AD. Latino respondents were less likely to perceive mental activity as a protective factor.

Conclusions

The study found limited ethnic group differences, with most items showing a similar pattern across groups. Nevertheless, the nature of the ethnic group differences found might be associated with a differential pattern of health service use. Copyright © 2013 John Wiley & Sons, Ltd.
KLF4 promoted odontoblastic differentiation of mouse dental papilla cells via regulation of DMP1
Authors: Lin Heng , Liu Huan , Sun Qin , Yuan Guohua , Zhang Lu , Chen Zhi
Published: April 2013

Odontoblasts, which derive from dental papilla, are a type of terminally differentiated matrix‐secreting cells. Previous studies have identified various transcription factors involved in the differentiation process of odontoblasts. We have recently found that Krüppel‐like factor 4 (Klf4) was expressed in the polarizing and elongating odontoblasts, but the function of Klf4 in the differentiation of odontoblasts is still unclear. We hypothesized Klf4 promoted the differentiation of odontoblasts by up‐regulating some odontoblast‐related genes. In this study, we found that the expression of Klf4 increased significantly during the odontoblastic differentiation of primary mouse dental papilla cells and the mouse dental papilla cell line‐mDPC6T. Overexpression of Klf4 significantly up‐regulated odontoblast‐related genes, such as Dmp1, Dspp, and Alp, and promoted the accumulation of mineral nodules. Knock‐down of Klf4 down‐regulated expression of Dmp1, Dspp, and Alp, and inhibited mineral deposition. We applied in silico analysis and identified one target gene of Klf4—Dmp1. Based on further analysis of ChIP data, EMSA and dual luciferase activity assays, we confirmed that Klf4 was able to specifically bind to the Dmp1 promoter and transactivate its expression. Furthermore, forced expression of Dmp1 in the Klf4 knock‐down mDPC6T cell line significantly recovered its odontoblastic differentiation ability. Our data confirmed our hypothesis that Klf4 promotes the differentiation of odontoblasts via the up‐regulation of Dmp1. J. Cell. Physiol. 228: 2076–2085, 2013. © 2013 Wiley Periodicals, Inc.
Caveolin and TGF‐β entanglements
Authors: Meyer Christoph , Liu Yan , Dooley Steven
Published: April 2013

Transforming growth factor (TGF)‐β is a multifunctional cytokine acting during development, tissue homeostasis, regeneration processes, and disease progression. Due to its pleiotropic effects, tight regulation of the induced signaling cascades is mandatory. Caveolin proteins regulate a specific endocytic pathway and modulate diverse signaling pathways and thus have been related to severe disorders, for example, cancer and fibrosis. Caveolin affects TGF‐β/‐Smad and non‐Smad signaling in many ways and thus can determine the cellular outcome upon TGF‐β challenge. Reciprocal regulation of caveolin and TGF‐β is also evident, ranging from gene expression to miRNA regulation. Finally, there is in vivo evidence that this crosstalk influences disease development and progression. This review gives an overview about the multifaceted relations of caveolin and TGF‐β. J. Cell. Physiol. 228: 2097–2102, 2013. © 2013 Wiley Periodicals, Inc.
FGF‐2 enhances Runx‐2/Smads nuclear localization in BMP‐2 canonical signaling in osteoblasts
Authors: Agas Dimitrios , Sabbieti Maria Giovanna , Marchetti Luigi , Xiao Liping , Hurley Marja M.
Published: April 2013

Bone morphogenetic protein 2 (BMP‐2) is one of the most potent regulators of osteoblast differentiation and bone formation. R‐Smads (Smads 1/5/8) are the major transducers for BMPs receptors and, once activated, they are translocated in the nucleus regulating transcription target genes by interacting with various transcription factors. Runx‐2 proteins have been shown to interact through their C‐terminal segment with Smads and this interaction is required for in vivo osteogenesis. In particular, recruitment of Smads to intranuclear sites is Runx‐2 dependent, and Runx‐2 factor may accommodate the dynamic targeting of signal transducer to active transcription sites. Previously, we have shown, by in vitro and in vivo experiments, that BMP‐2 up‐regulated FGF‐2 which is important for the maximal responses of BMP‐2 in bone. In this study, we found that endogenous FGF2 is necessary for BMP‐2 induced nuclear accumulation and co‐localization of Runx‐2 and phospho‐Smads1/5/8, while Runx/Smads nuclear accumulation and co‐localization was reduced in Fgf2−/− osteoblasts. Based on these novel data, we conclude that the impaired nuclear accumulation of Runx‐2 in Fgf2−/− osteoblasts reduces R‐Smads sub‐nuclear targeting with a consequent decreased expression of differentiating markers and impaired bone formation in Fgf2 null mice. J. Cell. Physiol. 228: 2149–2158, 2013. © 2013 Wiley Periodicals, Inc.
A novel algorithm to assess gross primary production for terrestrial ecosystems from MODIS imagery
Authors: Yang Yuting , Shang Songhao , Guan Huade , Jiang Lei
Published: April 2013

Quantifying carbon fluxes at large spatial scales has attracted considerable scientific attentions. In this study, a novel approach was proposed to estimate the terrestrial ecosystem gross primary production (GPP) using imagery from the satellite‐borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The new model (named Temperature and Greenness Rectangle, TGR) uses a combination of MODIS Enhanced Vegetation Index and Land Surface Temperature products as well as in situ measurement of photosynthetically active radiation to estimate GPP at a 16 day interval. Three major advantages are included in the model: (1) the model follows strictly the logic of the light use efficiency model and each parameter has physical meaning; (2) the model reduces the dependency on ground‐based meteorological measurements; and (3) the overlap of information in correlated explanatory variables is avoided. The model was calibrated with data from 17 sites within the Ameriflux network and validated at another 13 sites, covering a wide range of climates and eight major vegetation types. Results show that the TGR model explains reasonably well the tower‐based measurements of GPP for all vegetation types, except for the evergreen broadleaf forest, with the coefficient of determination in a range from 0.67 to 0.91 and the root mean square error from 9.0 to 31.9 g C/m2/16 days. Comparisons with other two models (the TG and GR model) show that the TGR model generally gives better GPP estimates in nearly all vegetation types, especially under dry climate conditions. These results indicate that the TGR model can be potentially used to estimate GPP at regional scale.
Molecular evidence for microorganisms participating in Fe, Mn, and S biogeochemical cycling in two low‐temperature hydrothermal fields at the Southwest Indian Ridge
Authors: Li Jiwei , Peng Xiaotong , Zhou Huaiyang , Li Jiangtao , Sun Zhilei
Published: April 2013

We examined two low‐temperature hydrothermal deposits rich in Fe‐Si‐Mn collected from the recently discovered hydrothermal fields at the Southwest Indian Ridge using mineralogical, geochemical, and molecular biological techniques. The mineralogical and geochemical analyses indicated that the low‐temperature hydrothermal fields would provide a warm and chemical species‐rich habitat for chemosynthetic‐based hydrothermal ecosystems. Analyses of 16S rRNA sequences showed that ζ‐Proteobacteria, Pseudoalteromonas, Leptothrix, and Pseudomonas were potential Fe and Mn oxidizers in the low‐temperature hydrothermal environments, but they were not present in equal abundance among the subniches. Some potential Fe and Mn reducers were also recovered; they were more commonly found in the exterior black Fe‐Mn oxides. The difference between the exterior black Fe‐Mn oxides and the interior Opal‐A could be related to differences in in situ physicochemical conditions. We also identified microbial players that may participate in sulfur (S) geochemical cycling in these low‐temperature hydrothermal environments via analyses of 16S rRNA sequences and the aprA functional gene. The results indicated that members of γ‐Proteobacteria and α‐Proteobacteria were involved in the S oxidation process, while members of δ‐Proteobacteria, Nitrospirae, Firmicutes, and Archaea might participate in the S reduction process. Fe, Mn, and S oxidizers and reducers might actively participate in hydrothermal biogeochemical processes, which could influence the transfer of chemical species and the formation of biogenic minerals.
Comparison of quiescent inflow single‐shot and native space for nonenhanced peripheral MR angiography
Authors: Ward Emily V. , Galizia Mauricio S. , Usman Asad , Popescu Andrada R. , Dunkle Eugene , Edelman Robert R.
Published: April 2013

Purpose

To evaluate two nonenhanced MRA methods: quiescent‐interval single‐shot (QISS) and Native SPACE (NATIVE = Non‐contrast Angiography of the Arteries and Veins; SPACE = Sampling Perfection with Application Optimized Contrast by using different flip angle Evolution), using contrast‐enhanced MR angiography (CEMRA) as a reference standard.

Materials and Methods

Twenty patients (14 male; mean, 69.3 years old) referred for lower extremity MRA were recruited in a HIPAA‐compliant prospective study. QISS and Native SPACE of the lower extremities were performed at 1.5 Tesla with a hybrid dual‐injection contrast‐enhanced MRA as reference. Image quality and stenosis severity were assessed in segments by two blinded radiologists. Methods were compared with logistic regression for correlated data for diagnostic accuracy.

Results

Of 496 arterial segments, 24 were considered nondiagnostic on the Native SPACE images. There were no QISS or CEMRA imaging segments considered to be nondiagnostic. Image quality was significantly higher for QISS than for Native SPACE. QISS stenosis sensitivity (84.9%) was not significantly different from Native SPACE (87.3%). QISS had better specificity (95.6%) than Native SPACE (87.0%), P = 0.0041. In comparison with QISS, Native SPACE proved less robust for imaging of the abdominal and pelvic segments.

Conclusion

Native SPACE and QISS were sensitive for hemodynamically significant stenosis in this pilot study. QISS NEMRA demonstrated superior specificity and image quality, and was more robust in the abdominal and pelvic regions. J. Magn. Reson. Imaging 2013;38:1531–1538. © 2013 Wiley Periodicals, Inc.
The effectiveness of manual circumlaryngeal therapy in future elite vocal performers
Authors: D'haeseleer Evelien , Claeys Sofie , Van Lierde Kristiane
Published: April 2013

Objectives/Hypothesis

The purpose of this study was to investigate the impact of a single session of manual circumlaryngeal therapy on the vocal characteristics of future elite vocal performers (music students).

Study Design

A pretest/post‐test control group design was used.

Methods

Sixteen music students were randomly divided in an experimental and control group. The experimental group received manual circumlaryngeal therapy for 20 minutes, whereas the control group was instructed to have complete vocal rest for 20 minutes. Immediately before and after the therapy or vocal rest, an identical objective voice assessment protocol (aerodynamic measurement, acoustic analysis, voice range profile, and Dysphonia Severity Index [DSI]) was performed. Vocal parameters were compared before and after manual circumlaryngeal therapy in the experimental group, and before and after vocal rest in the control group using the Wilcoxon signed rank test.

Results

In the experimental group a significant difference in DSI was found between the measurement before and after manual circumlaryngeal therapy. The median DSI increased from 6.3 before to 7.2 after manual circumlaryngeal therapy. No differences in DSI were found in the control group between the two measurements.

Conclusions

The results of this pilot study prudently suggest that manual circumlaryngeal therapy can also improve vocal capacities in the healthy trained voices of future elite vocal performers.

Level of Evidence

1b Laryngoscope, 123:1937–1941, 2013
Structural peculiarities of configurational isomers of 1‐styrylpyrroles according to 1Н, 13С and 15N NMR spectroscopy and density functional theory calculations: electronic and steric hindrance for planar structure
Authors: Afonin Andrei V. , Ushakov Igor A. , Pavlov Dmitry V. , Schmidt Elena Yu. , Dvorko Marina Yu.
Published: April 2013

Comparative analysis of the 1Н and 13С NMR data for a series of the E and Z‐1‐styrylpyrroles, E and Z‐1‐(1‐propenyl)pyrroles, 1‐vinylpyrroles and styrene suggests that the conjugation between the unsaturated fragments in the former compounds is reduced. This is the result of the mutual influence of the donor p–π and π–π conjugation having opposite directions. According to the NMR data combined with the density functional theory calculations, the Z isomer of 1‐styrylpyrrole has essentially a nonplanar structure because of the steric hindrance. However, the E isomer of 1‐styrylpyrrole is also an out‐of‐plane structure despite the absence of a sterical barrier for the planar one. Deviation of the E isomer from the planar structure seems to be caused by an electronic hindrance produced by a mutual influence of the p–π and π–π conjugation. The structure of the E isomer of the 2‐substituted 1‐styrylpyrroles is similar to that of the 2‐substituted 1‐vinylpyrroles. The steric effects in the Z isomer of the 2‐substituted 1‐styrylpyrroles result in the large increase of the dihedral angle between planes of the pyrrole ring and double bond. Copyright © 2013 John Wiley & Sons, Ltd.
Finite strain fracture of plates and shells with configurational forces and edge rotations
Authors: Areias P. , Rabczuk T.
Published: April 2013

We propose a simple and efficient algorithm for FEM‐based computational fracture of plates and shells with both brittle and ductile materials on the basis of edge rotation and load control. Rotation axes are the crack front nodes, and each crack front edge in surface discretizations affects the position of only one or two nodes. Modified positions of the entities maximize the modified mesh quality complying with the predicted crack path (which depends on the specific propagation theory in use). Compared with extended FEM or with classical tip remeshing, the proposed solution has algorithmic and generality advantages. The propagation algorithm is simpler than the aforementioned alternatives, and the approach is independent of the underlying element used for discretization. For history‐dependent materials, there are still some transfer of relevant quantities between elements. However, diffusion of results is more limited than with tip or full remeshing. To illustrate the advantages of our approach, three prototype models are used: tip energy dissipation linear elastic fracture mechanics (LEFM), cohesive‐zone approaches, and ductile fracture. Both the Sutton crack path criterion and the path estimated by the Eshelby tensor are employed. Traditional fracture benchmarks, including one with plastic hinges, and newly proposed verification tests are solved. These were found to be very good in terms of crack path and load ∕ deflection accuracy. Copyright © 2013 John Wiley & Sons, Ltd.
Targeting Potassium Channels Kv1.3 and KCa3.1: Routes to Selective Immunomodulators in Autoimmune Disorder Treatment?
Authors: Wang Jun , Xiang Ming
Published: April 2013

The Kv1.3 and KCa3.1 potassium channels are promising targets for the treatment of autoimmune disorders. Many Kv1.3 and KCa3.1 blockers have a more favorable adverse event profiles than existing immunosuppressants, suggesting the selectivity of Kv1.3 and KCa3.1 blockade. The Kv1.3 and KCa3.1 blockers exert differential effects in different autoimmune diseases. The Kv1.3 inhibitors or gene deletion have been shown to have benefits in multiple sclerosis, type 1 diabetes, rheumatoid arthritis, psoriasis, and rapidly progressive glomerulonephritis. The KCa3.1 blockers have demonstrated efficacy in human primary biliary cirrhosis and showed protective effects in animal models of severe colitis, allergic encephalomyelitis, inflammatory bowel disease, and multiple sclerosis. The KCa3.1 blockers are not considered candidates for treatment of multiple sclerosis. The selective immunosuppressive effects of the Kv1.3 and KCa3.1 blockers are due to the differences in their distribution on autoimmune–related immune cells and tissues and β1 integrin (very late activating antigen)–Kv1.3 channel cross‐talk.
Synthesis of block copolymers by transformation reactions in polymerisation systems
Authors: Abadie Marc J. M. , Ourahmoune Daouya
Published: April 2013

We present an overview on general methods allowing synthesis of block copolymers. Different transformations have been examined: anion to free radical, anion to cation and reverse, cation to free radical and reverse, anion to Ziegler‐Natta transformation, and coupling reactions of anion and cation.

This approach greatly extends the range of possible monomer combinations in block copolymers.
Disclinations an Langmuir—Blodgett films
Authors: Peterson Ian Robert
Published: April 2013

The Langmuir‐Blodgett (LB) technique is a method for depositing ultra‐thin organic films on a solid substrate. It has aroused considerable technological interest, and has been proposed for a wide range of applications. Most of these require homogeneous films with mechanical integrity. This paper demonstrates that a significant cause of pinholes and inhomogeneity is the existence in some LB films of a type of geometrical defect called the disclination. However they are not intrinsic to the films, and procedures exist for improving film characteristics.
Langmuir—Blodgett films from porphyrins
Authors: Tredgold Richard H. , Evans Steven D. , Hodge Philip , Jones Robert , Stocks Nigel G. , Young Martin C. J.
Published: April 2013

Recent work on Langmuir‐Blodgett films formed from porphyrins bearing short side chains is reviewed and some new results are reported.
Solution properties of polyelectrolytes. II. Comparison of the effects of both polyion and eluent salt concentrations on the calibrations in aqueous exclusion chromatography
Authors: Abad Concepción , Braco Lorenzo , Soria Vicente , García Rosa , Campos Agustín
Published: April 2013

The elution behaviour of charged water‐soluble polymers (sodium polystyrene sulphonate) in both salt‐free and NaCl‐containing aqueous mobile phases has been investigated by size‐exclusion chromatography. A comparative analysis has been established between the results as a function of polyion and salt concentrations, which demonstrates that the chromatographic behaviour is similar in both cases. The variation of the slopes of the different concentration‐dependent calibration curves is discussed in terms of polyelectrolyte conformational changes. Finally, a semi‐empirical model has been developed to predict the dependence of the elution volume in either polyion or salt concentration, and its validity has been checked in a range from very dilute to moderate concentrations.
Molecular characterisation of oxymethylene‐linked poly(oxyethylene)
Authors: Craven John R. , Nicholas Christian V. , Webster Robert , Wilson David J. , Mobbs Richard H. , Morris Gareth A. , Heatley Frank , Booth Colin , Giles Jeremy R. M.
Published: April 2013

Tetraethylene glycol (TEG) or polyethylene glycol 200 (PEG200) was reacted with CH2Br2 in a modified Williamson synthesis to form oxymethylene‐linked chains. Analytical and preparative gel permeation chromatography plus nuclear magnetic resonance spectroscopy were used to show that the product of reaction consisted of rings with degree of condensation n = 1−15 or more (i.e. 14 to 210 or more atoms in the rings formed from TEG) and chains with molecular weights up to 106 and a wide molecular weight distribution.
Langzeittragverhalten von in Verbundglas integrierten Lasteinleitungselementen
Authors: Denonville Jürgen , Puller Kerstin , Haase Walter , Sobek Werner
Published: April 2013

Im Rahmen eines Forschungsprojekts am Institut für Leichtbau Entwerfen und Konstruieren (ILEK) erfolgte die Untersuchung einer vielversprechenden Verbindungstechnologie im Glasbau, bei welcher metallische Elemente teilweise in die polymere Zwischenschicht (SentryGlas) eingebettet und zum Lastabtrag herangezogen werden. Neben Untersuchungen zum Tragverhalten unter kurzzeitiger Lasteinwirkung und deren numerischer Simulation, ist das Langzeitverhalten dieser Verbindung für eine umfassende Beschreibung des Tragverhaltens von besonderem Interesse. Dieser Artikel beschreibt die am ILEK durchgeführten Untersuchungen zum Tragverhalten der Verbindung unter Langzeitbeanspruchungen und gibt die Ergebnisse dieser Versuche wieder.

Long‐term Behaviour of Metal Inserts Partially Embedded in Laminated Glass. In the context of a research project at the Institute for Lightweight Structures and Conceptual design (ILEK) at the University of Stuttgart an innovative connection technique for structural glazing was investigated. The connection technique consists of a metal insert partially embedded in the interlayer (Sentry Glas), such that the interlayer acts as the adhesive for the structural connection. Besides investigations of the short‐term load‐bearing behaviour and the corresponding numerical simulation, the load‐bearing behaviour under long‐term loading is very important for a comprehensive characterization of this connection method. This paper describes the investigations that were conducted with respect to the long‐term behaviour and presents the experimental results.
Das Enzo Ferrari Museum ‐ eine Fusion zweier Designwelten
Authors: Blandini Lucio , Schmidt Timo , Winterstetter Thomas , Sobek Werner
Published: April 2013

Direkt gegenüber dem historischen Geburtshaus von Enzo Ferrari in Modena befindet sich das neue Museum für die Marken Ferrari und Maserati. Das äußere Erscheinungsbild dieses Gebäudes wird von einer geschwungenen Glasfassade und einer doppelt gekrümmten, stark an eine Fahrzeugkarosserie erinnernden Aluminiumhülle geprägt. Die Glasfassade ist bis zu 11 m hoch und wird von Edelstahlseilen getragen; maßgeschneiderte Sonnenschutzelemente und eine hochwertige Isolierverglasung optimieren den Energieeintrag bei gleichzeitig hoher Transparenz. Die metallische Außenhülle des Gebäudes ist aus Aluminiumelementen gefertigt, die im typischen Ferrari‐Gelb eingefärbt sind; das Fertigungssystem für diese Metallkonstruktion wurde dem Schiffsbau entlehnt. Dadurch konnte eine fugelose Hülle von extremer geometrischer Komplexität realisiert werden, deren Formensprache bewusst Assoziationen mit dem Automobildesign hervorruft.

Engineering the Skin of the “Casa Enzo Ferrari” Museum in Modena. The exhibition gallery of the Enzo Ferrari Museum in Modena has been designed by Future Systems London, referring to iconic free form elements of the sport car design. The gallery façade is composed of a curved glass envelope facing Enzo Ferrari’s birth house as well as of a free‐form yellow aluminum roof. This paper focuses on the customized solutions developed to engineer both the glass and the aluminum façade.
Wandartige Monoglasstützen unter axialen Drucklasten und Biegung
Authors: Langosch Katharina , Feldmann Markus , Hoffmeister Benno
Published: April 2013

Das Stabilitätsverhalten monolithischer Glasstützen bei reiner Drucklast ist mittlerweile weitgehend geklärt. Das Augenmerk richtet sich nun auf Stabilitätsfälle mit kombinierter Belastung. Hierzu zählt u.a. die gleichzeitige Einwirkung aus axialen Drucklasten und horizontalen Querlasten. Einen Anwendungsfall stellen wandartige Glasstützen im Fassadenbereich dar. Die analytische Bemessung solcher stabilitätsgefährdeter Glasbauteile unter kombinierter Beanspruchung wird im vorliegenden Aufsatz vorgestellt, was sich vorerst auf monolithische Querschnitte beschränkt. Die Verifizierung der analytischen Gleichungen erfolgt durch Experimente und Numerik. Eine Übertragung dieser Ergebnisse auf Verbundglasscheiben folgt in Kürze.

Monolithic glass columns under axial compressive load and bending. The question of the stability behavior of monolithic glass columns with pure normal force has been already treated in particular in the form of analytical buckling curves according to the European format. The focus has now turned to combined stability cases. These include inter alia the simultaneous action of axial compressive loads and horizontal shear loads. An application represents pane‐like glass columns in the façade. For the design such a lack of stability glass components under combined loads of vertical compressive loads and horizontal shear loads in this article analytical buckling curves are presented which so far are limited to monolithic glass. The analytical equations are verified by experimental and numerical investigations. The transfer of these results to glass columns with laminated cross sections is coming soon.
Geklebte Verbundbauteile aus Glas
Authors: Koschecknick Kai , Menkenhagen Jochen
Published: April 2013

Der Fachbeitrag befasst sich mit der Betrachtung numerischer Untersuchungen zu geklebten Verbundbauteilen aus Glas. In diesem Zusammenhang wird insbesondere auf das Erforschen benötigter Materialparameter von Klebstoffen und das Implementieren dieser Materialeigenschaften in ein FE‐Programm näher eingegangen. Da der Klebstoff im Verbund mit den Fügebauteilen meist als schwächstes Glied das recht komplexe Verformungsverhalten des Verbundsystems beeinflusst und gleichzeitig diesem auch unterliegt, ist eine wirklichkeitsnahe Abbildung der Materialeigenschaften nur über die Generierung eines angepassten Datensets experimenteller Versuche möglich.

Bonded composite components of glass. Subject of this technical paper is the numerical analysis of bonded composite components of glass. In this context especially within the research of required material properties of adhesives and the implementation of these characteristics into a FE‐software is gone into detail. As in most cases the adhesive in combination with the other components as the weakest part takes influence on the very complex deformation behaviour of the composite system and at the same time is also subject to it, the most realistic mapping of material characteristics can only be achieved by a generation of an adjusted data set resulting from experimental tests.
Untersuchungen zum Ermüdungsverhalten von gezielt vorgeschädigtem Floatglas aus Kalk‐Natron‐Silikatglas bei zyklischer Belastung
Authors: Hilcken Jonas , Boxheimer Kaja , Schneider Jens , Wörner Johann‐Dietrich
Published: April 2013

Bauteile, die zeitlich veränderlichen und periodisch wiederkehrenden Lasten ausgesetzt sind, müssen häufig auch hinsichtlich ihres Ermüdungsverhaltens eingestuft und bemessen werden. Im Glasbau fehlen hierzu noch Grundlagen auf der Widerstandsseite, denn das zyklische Ermüdungsverhalten von Glas für Anwendungen und Einwirkungen im Bauwesen ist im Unterschied zum statischen und dynamischen Ermüdungsverhalten bisher wenig untersucht. Der vorliegende Beitrag zeigt die Ergebnisse mehrerer Versuchsserien mit zyklischen Biegeversuchen von planmäßig vorgeschädigten Floatgläsern aus handelsüblichem Kalk‐Natron‐Silikatglas im Doppelring‐Biegeversuch und bei verschiedenen Frequenzen. Die Ergebnisse werden mit gängigen theoretischen Modellen zum Risswachstumsverhalten von Glas aus der Bruchmechanik verglichen.

Investigation of the fatigue behavior of systematically pre‐damaged soda‐lime float glass under cyclic loading. Structural components subjected to fluctuating and cyclic loading frequently have to be classified and designed considering cyclic fatigue. For the design of glass elements in structural engineering, fundamental knowledge about the resistance of glasses exposed to cyclic loading is limited. This article subsumes the results of several tests series with commercial annealed float glass (soda‐lime‐silica glass) that was specifically impaired and then tested cyclically with different frequencies using the double‐ring bending test. The results are compared to common theoretical models from fracture mechanics for the crack propagation in glass.
Bewegung in der Gebäudehülle? Gegenüberstellung passiver und aktiver Konzepte
Authors: Heusler Winfried
Published: April 2013

Bei Gebäudehüllen lassen sich gegenwärtig zwei gegensätzliche Trends beobachten: Passive und aktive Konzepte. Passive Gebäudehüllen schotten den Innenraum so weit wie möglich gegen äußere Einflüsse ab. Zeitgemäße Gebäudetechnik sorgt für behagliche Raumbedingungen. Im zweiten Fall reagieren aktive Komponenten der Gebäudehülle zielgerichtet auf wechselnde äußere und innere Bedingungen. Dabei wird angestrebt, den Einsatz der Gebäudetechnik zu minimieren. Es zeigt sich, dass rein passive Gebäudehüllen gegenüber aktiven Konzepten nur dann Vorteile bieten, wenn der Standort, die Höhe oder die Nutzung des Gebäudes die natürliche Lüftung sowie Solarenergie‐ und Tageslichtnutzung in mindestens zwei Dritteln des Jahres ausschließen.

Motion in the building envelope? Comparison of passive and active concepts. Two opposing trends can currently be observed with building envelopes: passive and active concepts. Passive building envelopes seal off the interior from external factors as far as possible. Contemporary building technology ensures a comfortable interior environment. Conversely, active components of the building envelope respond specifically to changing internal and external conditions. The aim here is to minimise the use of building technology. It shows that purely passive building envelopes are only advantageous when compared to active components if the location, the height or the use of the building excludes natural ventilation, as well as solar energy and use of natural light for at least two‐thirds of the year.
Zwischenbericht aus dem Arbeitskreis ‘Kantenfestigkeit‘ im Fachverband Konstruktiver Glasbau e.V. (FKG)
Authors: Ensslen Frank
Published: April 2013

Der Arbeitskreis ‘Kantenfestigkeit‘ im Fachverband Konstruktiver Glasbau e.V. wurde im Oktober 2009 gegründet und setzt sich aus Vertretern von Universitäten und der Glasindustrie zusammen. Er hat sich zur Aufgabe gesetzt, die Kantenfestigkeit bzw. ‐qualität in Abhängigkeit der Bearbeitungsarten KG (geschnitten), KGS (gesäumt) und KGN (geschliffen) anhand der Glasdicken 4, 6, 8 mm (Floatglas) experimentell zu untersuchen. Herausforderung dabei ist, aussagekräftige Zusammenhänge und statistisch abgesicherte Ergebnisse zu ermitteln. Der vorliegende Beitrag ist ein Zwischenbericht des seit drei Jahren tätigen Arbeitskreises. Es werden Einzelheiten zum Versuchsprogramm und dessen Vorbereitungen erläutert sowie die einzelnen Projektphasen. Fundierte Ergebnisse können voraussichtlich ab Sommer/Herbst 2013 gezeigt werden.

Interim report of the research group ‘Edge Strength’ at Fachverband Konstruktiver Glasbau. This working group was founded in October 2009. Representatives from universities and glass industry take part. The job is to investigate experimentally on the edge strength resp. edge quality dependent on the processing KG (cut), KGS (seamed), and KGN (Ground) for glass thicknesses 4, 6, 8 mm (Floatglass). The main challenge is to identify significant relations and to determine statistically assured results. This article is an interim report of three years work. The testing program and corresponding preparations are illustrated as well as the single project phases. Substantiated results are expected in summer/autumn 2013.
Load alleviation of wind turbines by yaw misalignment
Authors: Kragh Knud A. , Hansen Morten H.
Published: April 2013

Vertical wind shear is one of the dominating causes of load variations on the blades of a horizontal axis wind turbine. To alleviate the varying loads, wind turbine control systems have been augmented with sensors and actuators for individual pitch control. However, the loads caused by a vertical wind shear can also be affected through yaw misalignment. Recent studies of yaw control have been focused on improving the yaw alignment to increase the power capture at below rated wind speeds. In this study, the potential of alleviating blade load variations induced by the wind shear through yaw misalignment is assessed. The study is performed through simulations of a reference turbine. The study shows that optimal yaw misalignment angles for minimizing the blade load variations can be identified for both deterministic and turbulent inflows. It is shown that the optimal yaw misalignment angles can be applied without power loss for wind speeds above rated wind speed. In deterministic inflow, it is shown that the range of the steady‐state blade load variations can be reduced by up to 70%. For turbulent inflows, it is shown that the potential blade fatigue load reductions depend on the turbulence level. In inflows with high levels of turbulence, the observed blade fatigue load reductions are small, whereas the blade fatigue loads are reduced by 20% at low turbulence levels. For both deterministic and turbulent inflows, it is seen that the blade load reductions are penalized by increased load variations on the non‐rotating turbine parts. Copyright © 2013 John Wiley & Sons, Ltd.
Global sensitivity analysis of wind turbine power output
Authors: McKay Phillip M. , Carriveau Rupp , Ting David S‐K. , Johrendt Jennifer L.
Published: April 2013

The dynamics of wind turbine behavior are complex and a critical area of study for the wind industry. Identification of factors that cause changes in turbine performance can sometimes prove to be challenging, whereas other times, it can be intuitive. The quantification of the effect that these factors have is valuable for making improvements to both power performance and turbine health. In commercial farms, large quantities of meteorological and performance data are commonly collected to monitor daily operations. These data can also be used to analyze the relationship between each parameter in order to better understand the interactions that occur and the information contained within these signals. In this global sensitivity analysis, a neural network is used to model select wind turbine supervisory control and data acquisition system parameters for an array of turbines from a commercial wind farm that exhibit signs of wake interaction. An extended Fourier amplitude sensitivity test is then performed for 2 years of 10‐min averaged data. The study examines the primary and combined sensitivities of power output to each selected parameter for two turbines in the array. The primary sensitivities correspond to single parameter interactions, whereas combined sensitivities account for interactions between multiple parameters simultaneously. Highly influential parameters such as wind speed and rotor rotation frequency produce expected results; the extended Fourier amplitude sensitivity test method proved effective at quantifying the sensitivity of a wide range of more subtle inputs. These include blade pitch, yaw position, main bearing and ambient temperatures as well as wind speed and yaw position standard deviation. The technique holds promise for application in full‐scale wake studies where it might be used to determine the benefits of emerging power optimization strategies such as active wake management. The field of structural health monitoring can also benefit from this method. Copyright © 2013 John Wiley & Sons, Ltd.
Identifying streamgage networks for maximizing the effectiveness of regional water balance modeling
Authors: Fry L. M. , Hunter T. S. , Phanikumar M. S. , Fortin V. , Gronewold A. D.
Published: April 2013

Key Points

Some gages are better than others for extrapolation of streamflow.

Increased gaged area is not necessarily better for extrapolation.

Similarity in some key physical properties increases ARM skill.
Prophylactic Lymph Node Dissection in Papillary Thyroid Carcinoma: Is There a Place for Lateral Neck Dissection?
Authors: Ducoudray Romain , Trésallet Christophe , Godiris‐Petit Gaelle , Tissier Frédérique , Leenhardt Laurence , Menegaux Fabrice
Published: April 2013

Background

Cervical lymph node (LN) metastases are common in patients with papillary thyroid carcinoma (PTC), and they have a negative impact on recurrence. The management of preoperatively node‐negative (N0) PTC is still controversial. The aim of our study was to describe the results of a prophylactic bilateral lymph node dissection (LND) and to investigate its impact on recurrence.

Methods

From 2003 to 2011, we analyzed 603 consecutive preoperatively N0 PTC patients. For each patient, we reviewed demographics data, tumor characteristics, pattern and risk factors of LN metastasis, and outcome.

Results

Lymph node metastases were found in 23 % of patients: 19 % in the central compartment and 8 % in the lateral compartment, including 1 % in the lateral compartment on the opposite side from the tumor. Multivariate analysis showed that hyperthyroidism and extrathyroidal invasion of the tumor were significantly associated with LN metastasis. Further analysis showed that localization of the tumor in the upper third of the thyroid lobe and metastatic LN in the central compartment were independent risk factors for lateral LN metastasis. During the 4.3‐year follow‐up, 23 recurrences were observed (4 %), including 5 in the central compartment. Recurrence rates were 2 % in the N0 group, 5 % in N1a patients, and 22 % in N1b patients (p < 0.001).

Conclusions

In preoperatively N0 PTC patients, LN metastases are frequent in central and ipsilateral lateral compartments. Prophylactic LND in the central and ipsilateral lateral compartments should therefore be recommended in the presence of PTC to identify high‐risk patients.
Examining how professional development impacted teachers and students of U.S. history courses
Authors: Duffield Stacy , Wageman Justin , Hodge Angela
Published: April 2013

A causal-comparative, mixed methods design was used to study a partnership between a university and school district formed with the goal of improving history teachers’ United States history content knowledge to raise student engagement and achievement. Data were collected from middle and high school history teachers including teacher interviews, classroom observations, and student work. Student engagement surveys and academic performance data were also collected. Student academic performance was positively impacted and changes in classroom practice were found in the treatment group. However, differences in student engagement between groups were not found to be statistically significant.
On the Swap-Distances of Different Realizations of a Graphical Degree Sequence
Authors: ERDŐS PÉTER L. , KIRÁLY ZOLTÁN , MIKLÓS ISTVÁN
Published: April 2013

One of the first graph-theoretical problems to be given serious attention (in the 1950s) was the decision whether a given integer sequence is equal to the degree sequence of a simple graph (orgraphical, for short). One method to solve this problem is the greedy algorithm of Havel and Hakimi, which is based on theswapoperation. Another, closely related question is to find a sequence of swap operations to transform one graphical realization into another of the same degree sequence. This latter problem has received particular attention in the context of rapidly mixing Markov chain approaches to uniform sampling of all possible realizations of a given degree sequence. (This becomes a matter of interest in the context of the study of large social networks, for example.) Previously there were only crude upper bounds on the shortest possible length of such swap sequences between two realizations. In this paper we develop formulae (Gallai-type identities) for theswap-distances of any two realizations of simple undirected or directed degree sequences. These identities considerably improve the known upper bounds on the swap-distances.
The last Diagnostic and Statistical Manual (DSM): replacing our symptom-based diagnoses with a brain circuit-based classification of mental illnesses
Authors: Stahl Stephen M.
Published: April 2013

ISSUE:Current psychiatric diagnoses are defined “top-down” based upon clinical phenomenology, but may give way to defining mental illnesses “bottom-up” based upon genetic and molecular factors that regulate information processing in neuronal circuits, and that can be visualized with neuroimaging techniques.
Kurz- und langfristige Effekte außerfamiliärer Kleinkindbetreuung auf die kognitive und sprachliche Entwicklung unter besonderer Berücksichtigung der Betreuungsqualität
Authors: Bäuerlein Kerstin , Linkert Christine , Stumpf Eva , Schneider Wolfgang
Published: April 2013

Dieser Beitrag gibt einen Überblick über den aktuellen Forschungsstand bezüglich kurz- und langfristiger Effekte außerfamiliärer Kleinkindbetreuung auf die kognitive und sprachliche Entwicklung. Im Einzelnen wird auf die Einflüsse der Variablen Betreuungstyp, -quantität und -qualität eingegangen. Da sich die Qualität als besonders bedeutsam erwies, wird dieser Aspekt detaillierter betrachtet. Vor allem eine hohe Prozessqualität, also ein entwicklungsangemessener und bedürfnisorientierter Interaktionsablauf zwischen Kind und Betreuungsperson, scheint sich positiv auf die zentralen Entwicklungsbereiche auszuwirken. In einem zusammenfassenden Fazit werden Implikationen dargestellt, die sich aus den Studienergebnissen für die Gestaltung, Konzeption und Evaluation von Betreuungseinrichtungen für Kinder unter 3 Jahren ergeben.
Long-range interactions of excited He atoms with the alkaline earth atoms Mg, Ca, and Sr
Authors: Zhang J.-Y. , Mitroy J. , Yan Z.-C. , Babb J. F. , Sadeghpour H. R. , Schwingenschlögl U.
Published: April 2013

Dispersion coefficients for the long-range interactions of the first four excited states of He, i.e., He(2 1, 3S) and He(2 1, 3P), with the low-lying states of the alkaline earth atoms Mg, Ca, and Sr are calculated by summing over the reduced matrix elements of multipole transition operators.
A waveguide-coupled thermally isolated radiometric source
Authors: Rostem K. , Chuss D. T. , Lourie N. P. , Voellmer G. M. , Wollack E. J.
Published: April 2013

The design and validation of a dual polarization source for waveguide-coupled millimeter and sub-millimeter wave cryogenic sensors is presented. The thermal source is a waveguide mounted absorbing conical dielectric taper. The absorber is thermally isolated with a kinematic suspension that allows the guide to be heat sunk to the lowest bath temperature of the cryogenic system. This approach enables the thermal emission from the metallic waveguide walls to be subdominant to that from the source. The use of low thermal conductivity Kevlar threads for the kinematic mount effectively decouples the absorber from the sensor cold stage. Hence, the absorber can be heated to significantly higher temperatures than the sensor with negligible conductive loading. The kinematic suspension provides high mechanical repeatability and reliability with thermal cycling. A 33–50 GHz blackbody source demonstrates an emissivity of 0.999 over the full waveguide band where the dominant deviation from unity arises from the waveguide ohmic loss. The observed thermal time constant of the source is 40 s when the absorber temperature is 15 K. The specific heat of the lossy dielectric, MF-117, is well approximated by Cv(T) = 0.12 T 2.06 mJ g−1 K−1 between 3.5 K and 15 K.
Amino acids form strongly bound anions when substituted with superhalogen ligands
Authors: Sieradzan Iwona , Anusiewicz Iwona
Published: April 2013

The properties of AA-Y− anions (where AA = cysteine, aspartic acid, lysine; Y = BF3, PF5) were investigated at the ab initio Outer Valence Green's Function (OVGF)/6-311++G(3df,3pd)//MP2/6-311++G(d,p) level of theory. It is shown that introducing a superhalogen-like substituent to an amino acid (i.e., Cys, Asp, and Lys) results in obtaining molecules that bind an excess electron relatively strongly. The electronic stabilities of such resulting daughter anions are predicted to be substantial (5.3–6.9 eV).
Microwave complex permeability of Fe3O4 nanoflake composites with and without magnetic field-induced rotational orientation
Authors: Liu Xianguo , Wing Or Siu , Ming Leung Chung , Ho S. L.
Published: April 2013

Magnetite (Fe3O4) nanoflakes with widths of 100–200 nm and thicknesses of 10–80 nm were prepared by a hydrothermal synthesis method. Fe3O4 nanoflake composites with and without magnetic field-induced rotational orientation of flake planes of Fe3O4 nanoflakes in paraffin binder were fabricated using 35 wt. % Fe3O4 nanoflakes. The rotationally oriented composite showed higher permeability and resonance frequency than the nonoriented one, and its value of (μ0−1)fr reached 214.8 GHz and exceeded the Snoek's limit. Considering a uniform and a random distribution of flake planes of Fe3O4 nanoflakes in the oriented and nonoriented composites, respectively, the complex permeability of both composites was calculated using the Landau–Lifshitz–Gilbert equation and the Bruggeman's effective medium theory in the 2–18 GHz microwave frequency range.
Pulsed laser deposition with simultaneous in situ real-time monitoring of optical spectroscopic ellipsometry and reflection high-energy electron diffraction
Authors: Gruenewald J. H. , Nichols J. , Seo S. S. A.
Published: April 2013

We present a pulsed laser deposition system that can monitor growth by simultaneously using in situ optical spectroscopic ellipsometry (SE) and reflection high-energy electron diffraction (RHEED). The RHEED precisely monitors the number of thin-film layers and surface structure during the deposition, and the SE measures the optical spectra of the samples simultaneously. The thin-film thickness information obtained from RHEED facilitates the SE modeling process, which allows extracting the in situ optical spectra, i.e., the dielectric functions of thin-films during growth. The in situ dielectric functions contain indispensable information about the electronic structure of thin-films. We demonstrate the performance of this system by growing LaMnO3+δ (LMO) thin-films on SrTiO3 (001) substrates. By using in situ SE and RHEED simultaneously, we show that real-time thickness and dielectric functions of the LMO thin-films can be effectively extracted. The simultaneous monitoring of both optical SE and RHEED offers important clues to understand the growth mechanism of atomic-scale thin-films.