bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoluminescence and diffusion properties of O2 molecules in amorphous SiO2 nanoparticles
Authors: Agnello Simonpietro , Cannas Marco , Iovino Giuseppe , Vaccaro Lavinia , Gelardi Franco Mario 
Published: March 2013

AbstractAn experimental study by Raman and Photoluminescence (PL) spectroscopies on the emission and diffusion properties of O2 molecules in amorphous SiO2 nanoparticles of commercial origin with diameters from 14 to 40 nm is reported. Stationary and time resolved PL measurements have been carried out to characterize the Near Infrared (NIR) emission at 1272 nm of O2. Emission features similar to those of bulk silica systems with a sharp PL band and excitation channels in the NIR, at 1070 nm, and in the visible, at 765 and 690 nm are found, with peculiarities arising from embedding O2 in nanostructures. The study of the NIR PL lifetime as a function of temperature down to 10 K enabled to reveal the presence of non radiative processes competitive to the radiative channel and to the non‐radiative one already highlighted and related to high energy vibrational modes of matrix or of impurity sites. By detecting the O2 content of nanoparticles, the dynamics of diffusion in the low temperature range from 98°C up to 177°C has been characterized. The applicability of Fick's theory has been tested, determining the diffusion coefficients and evidencing some peculiarities detectable in the nanosystem. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surfactant‐Free Sub‐2 nm Ultrathin Triangular Gold Nanoframes
Authors: Shahjamali Mohammad Mehdi , Bosman Michel , Cao Shaowen , Huang Xiao , Cao Xiehong , Zhang Hua , Pramana Stevin Snellius , Xue Can 
Published: March 2013

AbstractUltrathin triangular gold nanoframes are synthesized in high yield through selective gold deposition on the edges of triangular silver nanoprisms and subsequent silver etching with mild wet etchants. These ultrathin gold nanoframes are surfactant‐free with tailorable ridge thickness from 1.8 to 6 nm and exhibit adjustable and distinct surface plasmon resonance bands in the visible and near‐IR region. In comparison, etching of the nanoprism template by galvanic replacement can only create frame structures with much thicker ridges, which have much lower catalytic activity for 4‐nitrophenol reduction than the ultrathin gold nanoframes.
Validity Evidence for Learning Progression‐Based Assessment Items That Fuse Core Disciplinary Ideas and Science Practices
Authors: Gotwals Amelia Wenk , Songer Nancy Butler 
Published: March 2013

AbstractThis article evaluates a validity argument for the degree to which assessment tasks are able to provide evidence about knowledge that fuses information from a progression of core disciplinary ideas in ecology and a progression for the scientific practice of developing evidence‐based explanations. The article describes the interpretive framework for the argument, including evidence for how well the assessment tasks are matched to the learning progressions and the methods for interpreting students' responses to the tasks. Findings from a dual‐pronged validity study that includes a think‐aloud analysis and an item difficulty analysis are presented as evidence. The findings suggest that the tasks provide opportunities for students at multiple ability levels to show evidence of both successes and struggles with the development of knowledge that fuses core disciplinary ideas with the scientific practice of developing evidence‐based explanations. In addition, these tasks are generally able to distinguish between different ability‐level students. However, some of the assumptions in the interpretive argument are not supported, such as the inability of the data to provide evidence that might neatly place students at a given level on our progressions. Implications for the assessment system, specifically, how responses are elicited from students, are discussed. In addition, we discuss the implications of our findings for defining and redesigning learning progressions. © 2013 Wiley Periodicals, Inc. J Res Sci Teach 50: 597–626, 2013.
Tennessee Emergency Hand Care Distributions and Disparities: Emergent Hand Care Disparities
Authors: Anthony Joshua R. , Poole Victoria N. , Sexton Kevin W. , Wang Li , Mueller Melissa A. , Guillamondegui Oscar , Shack R. Bruce , Thayer Wesley P. 
Published: March 2013

Background Hand trauma is the most frequently treated injury in emergency departments, but presently there is a crisis of insufficient emergency coverage. This study evaluates the discrepancy of emergent and elective hand care trends based on socioeconomic factors in the state of Tennessee. Method We identified 119 hospitals in Tennessee that contained operating and emergency room facilities. Of these, 111 hospitals participated in a survey to determine the availability of elective and emergency hand surgery. Wilcoxon rank-sum test or permutation chi-square test and logistic regression were used to analyze reported measures. Results Our results revealed that hospitals in counties with the lowest per capita income and median household income are less likely to have hand specialists or offer hand call. There are also significantly fewer hospitals that have hand specialists and offer hand call that are located in medically underserved areas. In the state of TN, level 1 trauma facilities are required by the Tennessee Department of Health to have staffed hand specialists and 24/7 hand call. Our study revealed that while 7/8 (87.5 %) level 1 trauma facilities have hand specialists, only 2/8 (25 %) provide 24/7 hand specialist call. Conclusion Our results strongly suggest the presence of a health care disparity for hand trauma in counties with a low income and in medically underserved areas.
Structural organization of large and very large scales in turbulent pipe flow simulation
Authors: Baltzer J. R. , Adrian R. J. , Wu Xiaohua 
Published: March 2013

AbstractThe physical structures of velocity are examined from a recent direct numerical simulation of fully developed incompressible turbulent pipe flow (Wu, Baltzer & Adrian, J. Fluid Mech., vol. 698, 2012, pp. 235–281) at a Reynolds number of ${\mathit{Re}}_{D} = 24\hspace{0.167em} 580$ (based on bulk velocity) and a Kármán number of ${R}^{+ } = 685$. In that work, the periodic domain length of $30$ pipe radii $R$ was found to be sufficient to examine long motions of negative streamwise velocity fluctuation that are commonly observed in wall-bounded turbulent flows and correspond to the large fractions of energy present at very long streamwise wavelengths (${\geq }3R$). In this paper we study how long motions are composed of smaller motions. We characterize the spatial arrangements of very large-scale motions (VLSMs) extending through the logarithmic layer and above, and we find that they possess dominant helix angles (azimuthal inclinations relative to streamwise) that are revealed by two- and three-dimensional two-point spatial correlations of velocity. The correlations also reveal that the shorter, large-scale motions (LSMs) that concatenate to comprise the VLSMs are themselves more streamwise aligned. We show that the largest VLSMs possess a form similar to roll cells centred above the logarithmic layer and that they appear to play an important role in organizing the flow, while themselves contributing only a minor fraction of the flow turbulent kinetic energy. The roll cell motions play an important role with the smaller scales of motion that are necessary to create the strong streamwise streaks of low-velocity fluctuation that characterize the flow.
Flow domain identification from free surface velocity in thin inertial films
Authors: Heining C. , Pollak T. , Sellier M. 
Published: March 2013

AbstractWe consider the flow of a viscous liquid along an unknown topography. A new strategy is presented to reconstruct the topography and the free surface shape from one component of the free surface velocity only. In contrast to the classical approach in inverse problems based on optimization theory we derive an ordinary differential equation which can be solved directly to obtain the inverse solution. This is achieved by averaging the Navier–Stokes equation and coupling the function parameterizing the flow domain with the free surface velocity. Even though we consider nonlinear systems including inertia and surface tension, the inverse problem can be solved analytically with a Fourier series approach. We test our method on a variety of benchmark problems and show that the analytical solution can be applied to reconstruct the flow domain from noisy input data. It is also demonstrated that the asymptotic approach agrees very well with numerical results of the Navier–Stokes equation. The results are finally confirmed with an experimental study where we measure the free surface velocity for the film flow over a trench and compare the reconstructed topography with the measured one.
Direct numerical simulation of the autoignition of a hydrogen plume in a turbulent coflow of hot air
Authors: Kerkemeier S. G. , Markides C. N. , Frouzakis C. E. , Boulouchos K. 
Published: March 2013

AbstractThe autoignition of an axisymmetric nitrogen-diluted hydrogen plume in a turbulent coflowing stream of high-temperature air was investigated in a laboratory-scale set-up using three-dimensional numerical simulations with detailed chemistry and transport. The plume was formed by releasing the fuel from an injector with bulk velocity equal to that of the surrounding air coflow. In the ‘random spots’ regime, autoignition appeared randomly in space and time in the form of scattered localized spots from which post-ignition flamelets propagated outwards in the presence of strong advection. Autoignition spots were found to occur at a favourable mixture fraction close to the most reactive mixture fraction calculated a priori from considerations of homogeneous mixtures based on inert mixing of the fuel and oxidizer streams. The value of the favourable mixture fraction evolved in the domain subject to the effect of the scalar dissipation rate. The hydroperoxyl radical appeared as a precursor to the build-up of the radical pool and the ensuing thermal runaway at the autoignition spots. Subsequently, flamelets propagated in all directions with complex dynamics, without anchoring or forming a continuous flame sheet. These observations, as well as the frequency of and scatter in appearance of the spots, are in good agreement with experiments in a similar set-up. In agreement with experimental observations, an increase in turbulence intensity resulted in a downstream shift of autoignition. An attempt is made to understand the key processes that control the mean axial and radial locations of the spots, and are responsible for the observed scatter. The advection of the most reactive mixture through the domain, and hence the history of evolution of the developing radical pools were considered to this effect.
Bending of elastic fibres in viscous flows: the influence of confinement
Authors: Wexler Jason S. , Trinh Philippe H. , Berthet Helene , Quennouz Nawal , du Roure Olivia , Huppert Herbert E. , Lindner Anke , Stone Howard A. 
Published: March 2013

AbstractWe present a mathematical model and corresponding series of microfluidic experiments examining the flow of a viscous fluid past an elastic fibre in a three-dimensional channel. The fibre’s axis lies perpendicular to the direction of flow and its base is clamped to one wall of the channel; the sidewalls of the channel are close to the fibre, confining the flow. Experiments show that there is a linear relationship between deflection and flow rate for highly confined fibres at low flow rates, which inspires an asymptotic treatment of the problem in this regime. The three-dimensional problem is reduced to a two-dimensional model, consisting of Hele-Shaw flow past a barrier, with boundary conditions at the barrier that allow for the effects of flexibility and three-dimensional leakage. The analysis yields insight into the competing effects of flexion and leakage, and an analytical solution is derived for the leading-order pressure field corresponding to a slit that partially blocks a two-dimensional channel. The predictions of our model show favourable agreement with experimental results, allowing measurement of the fibre’s elasticity and the flow rate in the channel.
A1-3 chromosomal translocations in Italian populations of the peach potato aphid Myzus persicae (Sulzer) not linked to esterase-based insecticide resistance
Authors: Rivi Marco , Monti Valentina , Mazzoni Emanuele , Cassanelli Stefano , Panini Michela , Anaclerio Matteo , Cigolini Manuela , Corradetti Bruna , Bizzaro Davide , Mandrioli Mauro , Manicardi Gian Carlo 
Published: March 2013

AbstractEsterase-based resistance in the peach-potato aphid, Myzus persicae (Sulzer), is generally due to one of two alternative amplified carboxylesterase genes, E4 or FE4 (fast E4). The E4 amplified form is distributed worldwide and it is correlated with a particular translocation between autosomes 1 and 3, whereas the FE4 form, which has hitherto not been found to be associated with chromosomal rearrangements, is typical of the Mediterranean regions. In this study, we present for the first time cytogenetic and molecular data on some M. persicae parthenogenetic lineages, which clearly show a chromosomal A1-3 translocation associated with esterase FE4 genes and unrelated to high levels of esterase-based resistance.
Incidence of post-intubation subglottic stenosis in children: prospective study
Authors: Schweiger C , Marostica P J Cauduro , Smith M M , Manica D , Carvalho P R Antonacci , Kuhl G 
Published: March 2013

AbstractObjective:To evaluate the incidence of subglottic stenosis in children undergoing endotracheal intubation.Methods:Children in the paediatric intensive care unit of a tertiary care hospital were considered eligible for inclusion if they received endotracheal intubation for more than 24 hours. After extubation, children underwent flexible fibre-optic nasolaryngoscopy. Based on this first evaluation, they were divided into two groups: ‘acute normal’, with mild laryngeal alterations or normal findings; and ‘acute alterations’, with moderate to severe laryngeal alterations. Further laryngoscopic follow up (7–10 days later) was undertaken for those children in the acute normal group who developed symptoms during follow up (after discharge from the intensive care unit), and for all children in the acute alterations group. Children were then classified into two final groups: ‘normal final examination’, with no chronic changes; and ‘subglottic stenosis’.Results:We included 123 children. The incidence of subglottic stenosis was 11.38 per cent (95 per cent confidence interval, 6.63–17.94 per cent). All the children who developed subglottic stenosis had had moderate to severe alterations immediately after extubation.Conclusion:This incidence of subglottic stenosis is quite high and needs further investigation to identify risk factors.
Human biology investigations during the heroic age of Antarctic exploration (1897–1922)
Authors: Guly H.R. 
Published: March 2013

ABSTRACTThis article describes the human biological data that was collected from the participants of the Antarctic expeditions of the ‘heroic age’ (1897–1922). Routine body weights, waist circumference, spirometry and grip strength measurements were performed on a number of the expeditions for monitoring health and at least four expeditions measured the haemoglobin level and demonstrated that anaemia did not occur. The only true research was done by Dr A.L. McLean of the Australasian Antarctic Expedition, who measured hair and nail growth and investigated immunity. By modern standards, the data collected is of little value but McLean's work laid the groundwork for modern research into the effects of Antarctic residence on the human organism.
Genetic characteristics of Shiga toxin-producingE. coliO157, O26, O103, O111 and O145 isolates from humans, food, and cattle in Belgium
Authors: VERSTRAETE K. , DE REU K. , VAN WEYENBERG S. , PIÉRARD D. , DE ZUTTER L. , HERMAN L. , ROBYN J. , HEYNDRICKX M. 
Published: March 2013

SUMMARYIn this study, we characterized 272 Shiga toxin-producingEscherichia coli(STEC) isolates from humans, food, and cattle in Belgium [O157 (n = 205), O26 (n = 31), O103 (n = 15), O111 (n = 10), O145 (n = 11)] for their virulence profile, whole genome variations and relationships on different genetic levels. Isolates of O157 displayed a wide variation ofstxgenotypes, heterogeneously distributed among pulsogroups (80% similarity), but with a concordance at the pulsosubgroup level (90% similarity). Of all serogroups evaluated, the presence ofeaewas conserved, whereas genes encoded on the large plasmid (ehx,espP,katP) occurred in variable combinations in O26, O103, and O145. The odds of having haemolytic uraemic syndrome was less for all genotypesstx2a,stx2c,stx1/stx2c, andstx1compared to genotypestx2a/stx2c; and for patients aged >5 years compared to patients aged ⩽5 years. Based on the genetic typing and by using epidemiological data, we could confirm outbreak isolates and suggest epidemiological relationships between some sporadic cases. Undistinguishable pulsotypes or clones with minor genotypic variations were found in humans, food, and cattle in different years, which demonstrated the important role of cattle as a reservoir of STEC O157, and the circulation and persistence of pathogenic clones.
Quand la passion autorise la transitivation d'un circonstanciel de lieu
Authors: CONDAMINES ANNE 
Published: March 2013

RÉSUMÉL'hypothèse testée dans cette étude est que des énoncés (a prioritrès inattendus) dans lesquels un complément de lieu figure en position d'objet sont néanmoins possibles dans des situations de communication associées à des domaines spécialisés, pourvu qu'elles se déroulent dans un contexte de connivence très fort. Le locuteur qui transitivise le complément fait alors le choix de mettre en exergue le lieu où se déroule l'action plutôt que l'objet. L'article décrit le cas de la pêche et s'appuie sur des occurrences repérées sur internet où interviennent le verbepêcheret le nomrivière. Il s'avère que la structurepêcher une rivière, en principe anormale, est relativement fréquente et apparaît majoritairement dans des sites personnalisés (blogs, forums). Ces éléments, associés à d'autres comme l'analyse du fonctionnement de l'adjectifpêchable, confirment l'hypothèse et ouvrent de nombreuses perspectives, notamment vers l'analyse discursive, la sémantique et la terminologie.
A logical framework combining model and proof theory
Authors: RABE FLORIAN 
Published: March 2013

Mathematical logic and computer science have driven the design of a growing number of logics and related formalisms such as set theories and type theories. In response to this population explosion, logical frameworks have been developed as formal meta-languages in which to represent, structure, relate and reason about logics.Research on logical frameworks has diverged into separate communities, often with conflicting backgrounds and philosophies. In particular, two of the most important logical frameworks are the framework of institutions, from the area of model theory based on category theory, and the Edinburgh Logical Framework LF, from the area of proof theory based on dependent type theory. Even though their ultimate motivations overlap – for example in applications to software verification – they have fundamentally different perspectives on logic.In the current paper, we design a logical framework that integrates the frameworks of institutions and LF in a way that combines their complementary advantages while retaining the elegance of each of them. In particular, our framework takes a balanced approach between model theory and proof theory, and permits the representation of logics in a way that comprises all major ingredients of a logic: syntax, models, satisfaction, judgments and proofs. This provides a theoretical basis for the systematic study of logics in a comprehensive logical framework. Our framework has been applied to obtain a large library of structured and machine-verified encodings of logics and logic translations.
Ca2+-Dependent Protein Kinase11 and 24 Modulate the Activity of the Inward Rectifying K+ Channels inArabidopsisPollen Tubes
Authors: Zhao Li-Na , Shen Li-Ke , Zhang Wen-Zheng , Zhang Wei , Wang Yi , Wu Wei-Hua 
Published: March 2013

AbstractPotassium (K+) influx into pollen tubes via K+ transporters is essential for pollen tube growth; however, the mechanism by which K+ transporters are regulated in pollen tubes remains unknown. Here, we report that Arabidopsis thaliana Ca2+-dependent protein kinase11 (CPK11) and CPK24 are involved in Ca2+-dependent regulation of the inward K+ (K+ in) channels in pollen tubes. Using patch-clamp analysis, we demonstrated that K+ in currents of pollen tube protoplasts were inhibited by elevated [Ca2+]cyt. However, disruption of CPK11 or CPK24 completely impaired the Ca2+-dependent inhibition of K+ in currents and enhanced pollen tube growth. Moreover, the cpk11 cpk24 double mutant exhibited similar phenotypes as the corresponding single mutants, suggesting that these two CDPKs function in the same signaling pathway. Bimolecular fluorescence complementation and coimmunoprecipitation experiments showed that CPK11 could interact with CPK24 in vivo. Furthermore, CPK11 phosphorylated the N terminus of CPK24 in vitro, suggesting that these two CDPKs work together as part of a kinase cascade. Electrophysiological assays demonstrated that the Shaker pollen K+ in channel is the main contributor to pollen tube K+ in currents and acts as the downstream target of the CPK11-CPK24 pathway. We conclude that CPK11 and CPK24 together mediate the Ca2+-dependent inhibition of K+ in channels and participate in the regulation of pollen tube growth in Arabidopsis.
Simulation of assembly operations using interchangeable parts for OM education
Authors: Costa Santos Luciano , Fabiana Gohr Cláudia , Vieira Junior Milton 
Published: March 2013

PurposeThe paper aims to present a hands‐on activity for operations management (OM) education that simulates assembly operations common in industrial settings using polyvinyl chloride (PVC) threadable fittings utilised in water pipes as interchangeable parts for easy manual assembly.Design/methodology/approachThe teaching method followed the philosophy of active learning and was applied in an action research approach; the proposed activity was tested and improved during applications in the classroom.FindingsThe applicability of the method was proven during in‐class exercises. The results were confirmed with positive feedback from the students involved in the exercises, which was obtained through a survey conducted after a set of applications.Research limitations/implicationsAlthough the proposed activity may have several possibilities for application, this paper focuses specifically on teaching the topics of work measurement and assembly line balancing, thus limiting the generalisability of these findings to other OM techniques. Therefore, it is important that the activity is further adapted to teach other OM topics.Practical implicationsThe activity performed with pipe fittings represents a practical exercise that contributes to reduction of the gap between theory and practice in OM education. Using simple and low cost materials, the students are involved in creating a real process from a fictional product.Originality/valueThis paper presents an experiential learning exercise applied using an innovative approach, using pipe fittings as interchangeable parts assembled in a production line.