bluuebunny/crossref_metadata_2025_split huggingface dataset:
Singularities of slice regular functions
Authors: Stoppato Caterina 
Published: February 2012

AbstractBeginning in 2006, G. Gentili and D. C. Struppa developed a theory of regular quaternionic functions with properties that recall classical results in complex analysis. For instance, in each Euclidean ball B(0, R) centered at 0 the set of regular functions coincides with that of quaternionic power series converging in B(0, R). In 2009 the author proposed a classification of singularities of regular functions as removable, essential or as poles and studied poles by constructing the ring of quotients. In that article, not only the statements, but also the proving techniques were confined to the special case of balls B(0, R). Quite recently, F. Colombo, G. Gentili and I. Sabadini (2010) and the same authors in collaboration with D. C. Struppa (2009) identified a larger class of domains, on which the theory of regular functions is natural and not limited to quaternionic power series. The present article studies singularities in this new context, beginning with the construction of the ring of quotients and of Laurent‐type expansions at points p other than the origin. These expansions, which differ significantly from their complex analogs, allow a classification of singularities that is consistent with the one given in 2009. Poles are studied, as well as essential singularities, for which a version of the Casorati‐Weierstrass Theorem is proven.
The benefits of the Met Office variable resolution NWP model for forecasting convection
Authors: Tang Yongming , Lean Humphrey W. , Bornemann Jorge 
Published: February 2012

ABSTRACTHigh‐resolution NWP models which can explicitly allow convection (albeit poorly resolved) are usually run in limited‐area domains, and are nested inside coarser resolution models with parametrized convection. The mismatch of the grids and model physics at the boundaries of the limited‐area fine resolution model can be a major source of model error. Two major issues are the change in the representation of convection (parameterized to explicit) as air enters the fine resolution model and the limited boundary updating frequency. In this paper, a variable‐grid, fine‐resolution, limited‐area version of the Met Office's Unified Model (UM), developed with the aim of addressing this and related problems with nested models is described. In this variable resolution model, the grid size varies smoothly from coarser (but still convection permitting) resolution at the outer boundaries to a uniform fine resolution in the interior of the domain. In this paper we present results from a comparison of this variable grid model with the analogous results from an equivalent nested model set with uniform high‐resolution model nested inside a lower resolution one. The comparison is carried out for a number of convective cases. It is found that the variable resolution model gives very similar results to the nested model system in the inner fixed resolution part of the domain away from the boundaries, both in individual case studies and when statistics are aggregated over cases. This gives confidence in the validity of the variable resolution approach. It is shown that the variable resolution model also gives the hoped for benefits of reducing artefacts at the boundaries.
Are Personal Characteristics Associated with Exercise Participation in Patients with Rheumatoid Arthritis? A Cross‐Sectional Explorative Survey
Authors: Vervloesem Nele , Van Gils Nele , Ovaere L. , Westhovens René , Van Assche Dieter 
Published: February 2012

AbstractBackgroundOrganized exercise programs for patients with rheumatoid arthritis (RA) are useful to enhance physical activity and fitness. However, participation and adherence rates of these programs are low. This study aimed to identify demographic, personal and disease‐related factors interfering with implementing an exercise program for RA.MethodsA random sample of ambulatory RA patients from a single centre was divided into two groups, depending on their willingness to participate in an exercise program. Subsequently, demographic data (gender, age, disease duration and educational level) and disease‐related and personal factors were obtained (Disease Activity Score; Short Form 36 [SF‐36]; Health Assessment Questionnaire; Global Disease Activity; and also the Utrecht Coping List [UCL], Illness Cognition Questionnaire; TAMPA scale and modified Baecke questionnaire).ResultsOf the 154 people completing the survey, 113 (73%) indicated that they were willing to participate in an exercise program. These positive responders (PR) were more often female (p < 0.05), and had a higher educational level (p < 0.05). In the negative responders (NR), higher scores were found in the general health perception (54.7; [SD 18.3] versus 47.4; [SD 20.8]) and vitality (61.6 [SD 19.8] versus 53.7 [SD 20.1] sections of the SF‐36, and a lower score was found on the reassuring thoughts subscale of the UCL (11.9 [SD 2.7] versus 12.9 [SD 2.7]) compared with the PR (all p < 0.05).ConclusionsAlthough few differences were found between the groups, some insights regarding pitfalls in implementing an exercise program were highlighted. Further insights into external and personal motivators for patients are needed. Copyright © 2012 John Wiley & Sons, Ltd.
Real‐time monitoring of undirected networks: Articulation points, bridges, and connected and biconnected components
Authors: Ausiello Giorgio , Firmani Donatella , Laura and Luigi 
Published: February 2012

AbstractIn this article, we present the first algorithm in the streaming model to characterize completely the biconnectivity properties of undirected networks: articulation points, bridges, and connected and biconnected components. The motivation of our work was the development of a real‐time algorithm to monitor the connectivity of the autonomous systems (AS) network, but the solution provided is general enough to be applied to any network. The network structure is represented by a graph, and the algorithm is analyzed in the datastream framework. Here, as in the on‐line model, the input graph is revealed one item (i.e., graph edge) after the other, in an on‐line fashion; but, if compared to traditional on‐line computation, there are stricter requirements for both memory occupation and per item processing time. Our algorithm works by properly updating a forest over the graph nodes. All the graph (bi)connectivity properties are stored in this forest. We prove the correctness of the algorithm, together with its space (O(nlog n), with n being the number of nodes in the graph) and time bounds. We also present the results of a brief experimental evaluation against real‐world graphs, including many samples of the AS network, ranging from medium to massive size. These preliminary experimental results confirm the effectiveness of our approach. © 2012 Wiley Periodicals, Inc. NETWORKS, Vol. 2012
Property Pd,m and efficient design of reliable networks
Authors: Faudree Ralph J. , Gould Ronald J. , Powell Jeffrey S. 
Published: February 2012

AbstractFor d ≥ 1 and m ≥ 1, a graph has property Pd,m if there exist at least m vertex‐disjoint paths of length at most d between each pair of vertices. Property Pd,m, which has a strong connection to wide diameter, is one way of measuring the reliability of a network. In this article, we first examine the relationship of Pd,m to other similar properties and then we prove several results regarding the extremal number for property Pd,m (the minimum number of edges needed for a graph to have the property). In particular, we find (i) the extremal number for graphs of certain orders when d = 2, (ii) several extremal graphs when d ≥ 3, (iii) a new lower bound on the extremal number when d ≥ 3, m ≥ 3, and (iv) a new upper bound on the extremal number when d,m are even with d = 4k + 2(k ≥ 1) and m ≥ 4. © 2012 Wiley Periodicals, Inc. NETWORKS, 2012
Dye‐sensitized TiO2 solar cells based on nanocomposite photoanode containing plasma‐modified multi‐walled carbon nanotubes
Authors: Chan Yen‐Fong , Wang Cheng‐Chien , Chen Bing‐Hung , Chen Chuh‐Yung 
Published: February 2012

ABSTRACTA series of anatase TiO2‐based nanocomposite incorporated with plasma‐modified multi‐walled carbon nanotubes (MWNTs) was prepared by physical blending and shows its capability for efficient electron transport when used as photoanode in dye‐sensitized solar cells (DSSCs). These MWNTs characterized with good dispersal performance were obtained by functionalization technique via in situ plasma treatment and subsequent grafting with maleic anhydride (MA) onto the external walls reported previously. Compared with the conventional DSSCs, the TiO2 film with 1D carbon nanotubes possesses more outstanding ability to transport electrons injected from the excited dye within the device under illumination. As a result, at an optimum addition of 0.3 wt% MWNTs‐MA in TiO2 matrix, the photocurrent–voltage (J–V) characteristics showed a significant increase in the short‐circuit photocurrent (Jsc) of 50%, leading to an increase in overall solar conversion efficiency by a factor of 1.5. Electrochemical impedance spectroscopy analyses reveal that the MWNTs‐MA/TiO2 incur smaller resistances at the photoanode in assembled DSSCs when compared with those in the anatase titania DSSCs. These features suggest that the conducting properties of the MWNTs‐MA within the anodes are crucial for achieving a higher transport rate for photo‐induced electrons in TiO2 layer by exhibiting lower resistance in the porous network and hence retard charge recombination that could result in poor conversion efficiency. Copyright © 2012 John Wiley & Sons, Ltd.
Polyfluorene derivatives pending iridium complexes: Improved optoelectronic properties by introducing D‐A units and altering pendent mode
Authors: Tan Hua , Yu Junting , Chen Jianhua , Nie Kaixuan , Chen Qing , Huang Ying , Zhang Zhiyong , Wang Yafei , Liu Yu , Lei Gangtie , Zhu Weiguo 
Published: February 2012

AbstractTo study influence of the donor(D)‐acceptor(A) units and pendent mode of phosphorescent moiety on the opto‐electronic properties for its resulting copolymers, two D‐A‐based polyfluorene derivatives (P1 and P2) pending the red‐emitting iridium bi(phenylisoquilonato) (picolinato) [Ir(Piq)2(pic)] unit and a polyfluorene derivative (P3) only pending Ir(Piq)2(pic) unit were synthesized and characterized, in which the donor of carbazole, the acceptor of oxadiazole are grafted into the C‐9 position of fluorene, the Ir(Piq)2(pic) unit is pended into either the C‐9 position for P1 and P3 or the end for P2 of fluorene by unconjugated linkage, respectively. Their opto‐electronic properties were significantly influenced by the D‐A units and pendent mode of the Ir(Piq)2(pic) unit. In the polymer light‐emitting devices with a configuration of ITO/PEDOT/polymers/LiF/Al, the P1 showed best electroluminescent properties than the P2 and P3. The maximum current efficiency of 0.72 cd/A and the highest luminance of 1398 cd/m2 were obtained in the P1‐based device, which are 1.3 and 1.5 times higher than those in the P2‐based device, respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Micro reflectance difference techniques: Optical probes for surface exploration
Authors: Lastras‐Martínez L. F. , del Pozo‐Zamudio O. , Herrera‐Jasso R. , Ulloa‐Castillo N.A. , Balderas‐Navarro R.E. , Ortega‐Gallegos J. , Lastras‐Martínez A. 
Published: February 2012

AbstractMicro reflectance difference spectroscopy (µ‐RDS) is a promising tool for the in‐situ and ex‐situ characterization of semiconductors surfaces and interfaces. We discuss and compare two different approaches used to measure µ‐RD spectra. One is based on a charge‐coupled device (CCD) camera, while the other uses a laser and a XY translation stage. To show the performance of these systems, we have measured surface optical anisotropies of GaSb(001) sample on which anisotropic strains have been generated by preferential mechanical polishing along [110] and $[1{\bar {1}}0]$ directions. The spectrometers are complementary and the selection of one of them depends on the sample to be investigated and on experimental conditions.
Plasmonic antennas, positioning, and coupling of individual quantum systems
Authors: Dregely Daniel , Lindfors Klas , Dorfmüller Jens , Hentschel Mario , Becker Merle , Wrachtrup Jörg , Lippitz Markus , Vogelgesang Ralf , Giessen Harald 
Published: February 2012

AbstractPlasmonic nanoantennas can enhance the radiative decay rate of quantum emitters via the Purcell‐effect. Similar to their radiofrequency equivalents, they can also direct the emitted light into preferential directions. In this paper we first investigate plasmonic Yagi‐Uda antennas that are able to confine light to and direct light from subwavelength size volumes. Hence, enhanced transition rates and directed emission are expected when near‐field coupling between quantum emitters and the antennas is achieved. Second, we present suitable techniques to couple different quantum systems to plasmonic antennas. We use top‐down fabrication techniques to achieve positioning of individual quantum emitters relative to plasmonic nanostructures with an accuracy better than 10 nm. We assure a sufficiently small distance for an efficient near‐field coupling of the transition dipole to the plasmonic nanoantenna, which is, however, large enough not to quench the transition. The hybrid system using quantum dots, molecules, or nitrogen‐vacancy (NV)‐centers in diamond can serve as an efficient single photon source. It is suitable for high‐speed information transfer at optical frequencies on the nanoscale for future applications.
The role of oxygen‐induced processes on the emission characteristics of single molecule emitters
Authors: Nothaft Maximilian , Höhla Steffen , Jelezko Fedor , Pflaum Jens , Wrachtrup Jörg 
Published: February 2012

AbstractSingle molecule studies are limited to a defined class of organic dye molecules inserted into respective host materials. Basic requirements for suited material combinations include high photon emission rates and long term photostability. A majority of known aromatic host–guest systems employ crystalline organic matrices to prevent dye molecules from uncontrolled reactions with contaminants. However, in terms of device fabrication and technological potentials it is often desirable to use polymers as room temperature host matrices. Unfortunately, single dye molecule investigations in polymers at room temperature usually report orders of magnitude lower photostabilities compared to their crystalline molecular counterparts, leading to a reduced interest in organic thin film applications. In this report, we exemplary demonstrate the feasibility of engineering a host–guest system based on dibenzoterrylene dye molecules which were diluted into the polymer poly‐(p‐phenylene‐vinylene) (PPV) possessing very low photobleaching probabilities at room temperature. By controlling the oxygen exposure during manufacturing the number of emitted photons prior to photobleaching was significantly increased from 106 up to 1011 photons. Employing suited encapsulation techniques to prevent oxygen penetration after host–guest preparation, photostable devices over prolonged time periods on the order of months to years could be achieved. Therefore, this approach grants access to a variety of new polymer based combinations of host–guest systems for studying single molecular quantum emitters inside organic electronic devices and nanostructured polymer films with sufficient count rates and long‐term stability at room temperature.
Effect of defects in ferromagnetic C doped ZnO thin films
Authors: Subramanian Munisamy , Akaike Yuhei , Hayashi Yasuhiko , Tanemura Masaki , Ebisu Hiroshi , Ping Daniel Lau Shu 
Published: February 2012

AbstractThe present work investigates the relation between ferromagnetism and intrinsic defects of C‐doped ZnO thin films. The room‐temperature ferromagnetism (RTFM) in C‐doped ZnO is due to the charge transfer between Zn 4s and C 2p orbitals. The long‐range magnetic interaction in C‐doped ZnO is due to carbon–carbon interaction mediated by oxygen. The oxygen‐ and zinc‐related defects in C‐doped ZnO affect the mediation of ferromagnetic interaction and the existence of hybridization between Zn and C, respectively.
Entrepreneurial orientation, social capital, and the internationalization of SMES: Evidence from China
Authors: Zhang Xiao , Ma Xufei , Wang Yue 
Published: February 2012

AbstractThis article combines arguments from entrepreneurship literature and social capital theory to examine the antecedents to the internationalization of small and medium‐sized enterprises (SMEs) from China. Our quantitative study of 117 Chinese SMEs demonstrates the overall importance of entrepreneurial orientation and social capital of entrepreneurs in facilitating their internationalization efforts, and also reveals that different dimensions of entrepreneurial orientation and different types of social capital exert different levels of independent influence on Chinese SMEs' internationalization. Complementary data from multiple case studies explains the variation between our quantitative findings and the findings of previous research. By highlighting the value of the entrepreneurial attributes of Chinese SMEs and the social capital embedded in their networks in the pursuit of their internationalization, the article adds to the scant literature on the internationalization behavior of the rapidly emerging Chinese SMEs. © 2012 Wiley Periodicals, Inc.
Splanchnic Artery Stenosis and Abdominal Complaints: Clinical History Is of Limited Value in Detection of Gastrointestinal Ischemia
Authors: ter Steege R. W. F. , Sloterdijk H. S. , Geelkerken R. H. , Huisman A. B. , van der Palen J. , Kolkman J. J. 
Published: February 2012

AbstractBackgroundSplanchnic artery stenosis is common and mostly asymptomatic and may lead to gastrointestinal ischemia (chronic splanchnic syndrome, CSS). This study was designed to assess risk factors for CSS in the medical history of patients with splanchnic artery stenosis and whether these risk factors can be used to identify patients with high and low risk of CSS.MethodsAll patients referred for suspected CSS underwent a standardized workup, including a medical history with questionnaire, duplex ultrasound, gastrointestinal tonometry, and angiography. Definitive diagnosis and treatment advice was made in a multidisciplinary team. Patients with confirmed CSS were compared with no‐CSS patients.ResultsA total of 270 patients (102 M, 168 F; mean age, 53 years) with splanchnic artery stenosis were analyzed, of whom 109 (40%) had CSS and 161 no CSS. CSS‐patients more often reported postprandial pain (87% vs. 72%, p = 0.007), weight loss (85% vs. 70%, p = 0.006), adapted eating pattern (90% vs. 79%, p = 0.005) and diarrhea (35% vs. 22%, p = 0.023). If none of these risk factors were present, the probability of CSS was 13%; if all were present, the probability was 60%. Adapted eating pattern (odds ratio (OR) 3.1; 95% confidence interval (CI) 1.08–8.88) and diarrhea (OR 2.6; 95% CI 1.31–5.3) were statistically significant in multivariate analysis.ConclusionsIn patients with splanchnic artery stenosis, the clinical history is of limited value for detection of CSS. A diagnostic test to detect ischemia is indispensable for proper selection of patients with splanchnic artery stenosis who might benefit from treatment.
Differences in developmental changes in GABAergic response between bushy and stellate cells in the rat anteroventral cochlear nucleus
Authors: Song Ning‐ying , Shi Hai‐bo , Li Chun‐yan , Yin Shan‐kai 
Published: February 2012

AbstractMany mammalian central nervous system neuron responses mediated by GABAA receptors undergo a developmental transition from excitation to inhibition, but little is known about the time of this switch in specific cell types in the developing anteroventral cochlear nucleus (AVCN). In the present study, bushy and stellate cells, two major cell types in the AVCN, were identified according to their morphology and electrophysiology. The equilibrium potential of GABA‐evoked currents (EGABA) was examined using the gramicidin‐perforated patch‐clamp technique. We found that the action of GABA in bushy and stellate cells switched from predominantly depolarizing to predominantly hyperpolarizing with respect to their resting membrane potential (Vrest) at different postnatal ages. Such a switch in the GABA response of bushy cells occurred before the first postnatal week, whereas that in stellate cells happened at the end of the second postnatal week. Furthermore, we discovered that bushy cells had a more depolarized Vrest than did stellate cells before the second postnatal week; however, the EGABA of bushy and stellate cells was not significantly different. Thus, the discrepancy in the timing of the developmental shift from depolarizing to hyperpolarizing GABA responses between bushy and stellate cells may be due to the difference in their Vrest, but not due to EGABA itself. These results suggest that GABAergic inhibition functions earlier in bushy than in stellate cells. In contrast, the longer excitatory action of GABA on stellate cells possibly renders them more vulnerable than bushy cells to excitotoxic substances during early development.
Effects of high-dose fish oil supplementation during early infancy on neurodevelopment and language: a randomised controlled trial
Authors: Meldrum Suzanne J. , D'Vaz Nina , Simmer Karen , Dunstan Janet A. , Hird Kathryn , Prescott Susan L. 
Published: February 2012

n-3 Long-chain PUFA (LC-PUFA) intake during infancy is important for neurodevelopment; however, previous studies ofn-3 LC-PUFA supplementation have been inconclusive possibly due to an insufficient dose and limited methods of assessment. The present study aimed to evaluate the effects of direct supplementation with high-dose fish oil (FO) on infant neurodevelopmental outcomes and language. In the present randomised, double-blind, placebo-controlled trial, 420 healthy term infants were assigned to receive a DHA-enriched FO supplement (containing at least 250 mg DHA/d and 60 mg EPA/d) or a placebo (olive oil) from birth to 6 months. Assessment occurred at 18 months via the Bayley Scales of Infant and Toddler Development (3rd edition; BSID-III) and the Child Behavior Checklist. Language assessment occurred at 12 and 18 months via the Macarthur–Bates Communicative Development Inventory. The FO group had significantly higher erythrocyte DHA (P = 0·03) and plasma phospholipid DHA (P = 0·01) levels at 6 months of age relative to placebo. In a small subset analysis (about 40 % of the total population), children in the FO group had significantly higher percentile ranks of both later developing gestures at 12 and 18 months (P = 0·007;P = 0·002, respectively) and the total number of gestures (P = 0·023;P = 0·006, respectively). There was no significant difference between the groups in the standard or composite scores of the BSID-III. The results suggest that improved postnataln-3 LC-PUFA intake in the first 6 months of life using high-dose infant FO supplementation was not beneficial to global infant neurodevelopment. However, some indication of benefits to early communicative development was observed.