bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral characteristics and dynamics of a light hole type quantum dot doped with a single Mn atom
Authors: Reiter D. E. , Axt V. M. , Kuhn T. 
Published: April 2012

AbstractFor a single semiconductor quantum dot doped with a single Mn atom we study theoretically the spectral characteristics and dynamics under optical excitation. Because the Mn spin couples to the electron and hole spin of the quantum dot exciton via the exchange interaction, in the absorption spectrum instead of a single exciton line a set of lines appears. Here we consider a quantum dot with one conduction band and one light hole type valence band. Due to this untypical valence band structure a spectrum of twelve lines is seen at zero magnetic field. When a magnetic field is applied, the lines shift, cross and anticross. By an analysis of the corresponding eigenvalues and eigenfunctions as functions of the magnetic field more insight into the spectral behavior can be achieved. The exchange interaction furthermore opens the possibility for ultra fast control of the Mn spin via optical manipulation of the exciton. We analyze whether switching of the Mn spin can be optimized by the application of an external magnetic field. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Terahertz transitions in Aharonov‐Bohm quantum rings in an external electric field
Authors: Alexeev A. M. , Portnoi M. E. 
Published: April 2012

AbstractMagneto‐oscillations of the electric dipole moment are predicted and analyzed for a single‐electron nanoscale ring pierced by a magnetic flux (an Aharonov‐Bohm ring) and subjected to an electric field in the ring's plane.These oscillations are accompanied by periodic changes in the selection rules for inter‐level optical transitions in the ring allowing control of polarization properties of the associated terahertz radiation. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structuration and Integration of Magnetic Nanoparticles on Surfaces and Devices
Authors: Bellido Elena , Domingo Neus , Ojea‐Jiménez Isaac , Ruiz‐Molina Daniel 
Published: April 2012

AbstractDifferent experimental approaches used for structuration of magnetic nanoparticles on surfaces are reviewed. Nanoparticles tend to organize on surfaces through self‐assembly mechanisms controlled by non‐covalent interactions which are modulated by their shape, size and morphology as well as by other external parameters such as the nature of the solvent or the capping layer. Further control on the structuration can be achieved by the use of external magnetic fields or other structuring techniques, mainly lithographic or atomic force microscopy (AFM)‐based techniques. Moreover, results can be improved by chemical functionalization or the use of biological templates. Chemical functionalization of the nanoparticles and/or the surface ensures a proper stability as well as control of the formation of a (sub)monolayer. On the other hand, the use of biological templates facilitates the structuration of several families of nanoparticles, which otherwise may be difficult to form, simply by establishing the experimental conditions required for the structuration of the organic capsule. All these experimental efforts are directed ultimately to the integration of magnetic nanoparticles in sensors which constitute the future generation of hybrid magnetic devices.
Leistungsfähige Spiegel für solarthermische Kraftwerke
Authors: Schiller Matthias , Höing Thomas 
Published: April 2012

AbstractSpiegel sind ein wesentlicher Bestandteil solarthermischer Kraftwerke. Mittels Nasschemie hergestellte Silberspiegel der Flabeg GmbH erreichen in Kombination mit speziellem Solarglas eine solare, gerichtete Reflexion von im Mittel 94,4%. Fast 30 Jahre Felderfahrung sind ein Beweis für die Beständigkeit der Beschichtung.Mit Oberflächenspiegeln könnte man die Reflexion weiter erhöhen, doch lassen sie sich noch nicht in der gewünschten Qualität bzw. zu einem wettbewerbsfähigen Preis herstellen.Ein anderer Ansatz zur Erhöhung der Reflexion ist die Ausstattung mit einer schmutzabweisenden Beschichtung. Solche Spiegel befinden sich in Feldtests, die bereits vielversprechende Ergebnisse zeigen.Mit neuartigen Lacksystemen wird es möglich sein, Silberspiegel auch in küstennahen Regionen oder den Tropen einzusetzen.
Electron transfer in DNA
Authors: Siriwong Khatcharin , Voityuk Alexander A. 
Published: April 2012

AbstractDuring the last two decades, electron transfer (ET) through DNA and its artificial analogues has been an area of extensive experimental and theoretical studies. This process plays an important role in biology (damage and repair of DNA in living cells) and is of potential interest in material sciences. Because structural dynamics of the π stack and its environment affect essentially the electron transport, some significant details of excess charge migration cannot be derived from experiments. Computer simulations of the ET process provide microscopic insights into mechanisms of this process. In the paper, we consider computational methods used to describe the propagation of excess charges through π stacks of DNA and related systems. © 2012 John Wiley & Sons, Ltd.This article is categorized under:

Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods
P2Y receptors in microglia and neuroinflammation
Authors: Hidetoshi Tozaki‐Saitoh , Makoto Tsuda , Inoue Kazuhide 
Published: April 2012

AbstractMicroglia are surveillants in the central nervous system. Once they find abnormal or emergency signals, microglia can migrate to the site of the injury, release pro‐inflammatory and/or neurotrophic substances, and phagocytose damaged cells and their remnants. Extracellular nucleotides act through purinoceptors and have been implicated as signaling molecules used by microglia to sense adverse physiological conditions. The P2Y12 receptor is responsible for microglial chemotactic function toward an ATP source. The P2Y6 receptor stimulates phagocytic activity of microglia in response to extracellular UDP. Each receptor elicits transient intracellular calcium elevation and this may induce the expression of several genes related to microglial activation. Both receptor‐mediated signaling and cellular functions may be involved in the pathology occurring in the central nervous system. Therefore, determining the definitive microglial functions mediated by P2Y receptors supports understanding the pathological cascade and finding new therapeutic targets related to microglia. WIREs Membr Transp Signal 2012, 1:493–501. doi: 10.1002/wmts.46For further resources related to this article, please visit the WIREs website.Conflict of interest: The authors have no conflict of interest to declare.
Faculty and student perceptions of the feasibility of individual student–faculty
meetings
Authors: Mulder B. F. , Erich M. H. , Borleffs J. C. C. , Elgersma A. F. , Cohen-Schotanus J. 
Published: April 2012

The extent to which students feel involved in their education positively
influences academic achievement. Individual student–faculty meetings can foster student
involvement. To be effective, faculty acknowledgement of the benefit of these meetings
is a prerequisite. The aim of this study was to explore faculty perceptions of
individual student–faculty meetings. In addition we investigated students’ perceptions.
As part of the undergraduate programme, mandatory individual intake and follow-up
meetings between first-year medical students (n = 425) and senior faculty members
(n = 34) have been implemented from 2009 onwards. We administered a questionnaire on
faculty perceptions of the benefit and impact of intake meetings. Subsequently, after
both meetings had been held, strong and weak points of the mandatory programme were
explored using open-ended questions. Students’ perceptions were investigated by
open-ended questions as a part of the curriculum evaluation process. Faculty enjoyed the
meetings (90 %), perceived the meetings to be beneficial (74 %) and expected a positive
effect on student involvement (74 %). Faculty appreciated the opportunity to give advice
tailored to students’ personal needs and levels of performance. The students appreciated
the meetings and the attention given to their personal situation and study progress.
Faculty and student appreciation of the meetings seems to support the assumption that
the individual meetings increase students’ social and academic involvement. Further
research should focus on the impact of individual student–faculty meetings on students’
learning behaviours.
Prevalence and severity of vitamin D deficiency in patients with diabetic foot infection
Authors: Tiwari Shalbha , Pratyush Daliparthy D. , Gupta Balram , Dwivedi Awanindra , Chaudhary Sandeep , Rayicherla Rammohan K. , Gupta Sanjeev K. , Singh Surya Kumar 
Published: April 2012

The aim of the present research was to study the prevalence and severity of vitamin D deficiency in patients with diabetic foot infection. Patients were enrolled in two groups: diabetic patients with foot infection (n 125) as cases and diabetic patients without the infection as controls (n 164). Serum 25-hydroxyvitamin D (25(OH)D) was measured by RIA. Data were presented as means and standard deviations unless otherwise indicated and were analysed by SPSS. Results revealed that 25(OH)D (nmol/l) was significantly lower (40·25 (sd 38·35) v. 50·75 (sd 33·00); P < 0·001) in cases than in controls. Vitamin D inadequacy (25(OH)D < 75 nmol/l) was equally common in cases and controls (OR 1·45, 95 % CI 0·8, 3·0; P = 0·32), but cases had a greater risk of vitamin D deficiency (25(OH)D < 50 nmol/l) than controls (OR 1·8, 95 % CI 1·1, 3·0; P = 0·02). Risk of severe vitamin D deficiency (25(OH)D < 25 nmol/l) was significantly higher in cases than in controls (OR 4·0, 95 % CI 2·4, 6·9; P < 0·0001). Age, duration of diabetes and HbA1c were significantly higher in cases than in controls and therefore adjusted to nullify the effect of these variables, if any, on study outcome. The study concluded that vitamin D deficiency was more prevalent and severe in patients with diabetic foot infection. This study opens up the issue of recognising severe vitamin D deficiency ( < 25 nmol/l) as a possible risk factor for diabetic foot infections and the need for vitamin D supplementation in such patients for a better clinical outcome. This could be substantiated by similar data from future studies.
Trio A in Europe
Authors: Burt Ramsay 
Published: April 2012

Since the mid-1990s European dancers and audiences have played a significant role in the revival of interest in Yvonne Rainer's dance work. Two key examples of this are the restaging of Rainer's Continuous Project-Altered Daily (CP-AD) in 1996 by the French group Quatuor Albrecht Knust and the more recent creation and trial of the Labanotation score of Trio A in London. In her reminiscences printed above, Pat Catterson suggests that Trio A' s “relaxed natural quality, equality of parts, its tame simplicity, and durational patience may be out of synch with today's Zeitgeist.” During Charles Atlas's documentary, Rainer Variations, Rainer herself suggests today's audiences would no longer be prepared to sit through the long slow works she made during the Judson period. If this is currently the case with audiences in the United States, it is not so on the other side of the Atlantic. European audiences for innovative dance and live art seem prepared to take the time to experience and appreciate slow, demanding, experimental work.European choreographers and dance artists who have been interested in Trio A often have a keen and sophisticated, if idiosyncratic, interest in dance history. Artists I have spoken to suggest this interest helps them build on what has already been done and makes them aware of a broader range of creative possibilities. Some say they find it useful to discover dance artists in the past who were working in ways that are similar to their own practices. For example, Xavier Le Roy, who took part in the 1996 restaging of Rainer's CP-AD, performed the “chair pillow” section from it during his 1999 performative lecture Product of Circumstances. His discovery of ordinary, task-based, and pedestrian movement in Rainer's work affirmed his own research into similar kinds of movement.
Failed Impressions: Diaghilev's Ballets Russes in America, 1916
Authors: Järvinen Hanna 
Published: April 2012

In 1916 the Russian impresario Sergei Diaghilev (1872–1929) took the Ballets Russes out of war-torn Europe for a tour across the North American continent. The tour was scheduled to run from January to April 1916, with short seasons in New York at the beginning and the end. As it turned out, the company returned for a second tour that ran from late September to January 1917, during which time, however, Diaghilev's former lover and principal star dancer, Vaslav Nijinsky (1889–1950), replaced him as director.In this article I discuss the cultural differences at the heart of the Ballets Russes' failure to conquer America in 1916–1917, and why that failure had to be edited out of history. Specifically, I look at three aspects of the publicity and critical reception: elitism, patriotism, and modernism. The publicists of the company both misunderstood and underestimated their audience, but in dance research, their prejudices have been taken for granted. The “eye-witness accounts” of Diaghilev's employees and the histories of the company written in the first half of the twentieth century have largely gone unquestioned since, but contemporary primary sources of the North American tours tell a different story. By contrasting the first tour with the second, which received less publicity and better reviews, I emphasize the practical experience of touring in the New World and how differently American critics evaluated the achievements of the two Russian directors of the company—Diaghilev (for the first tour) and Nijinsky (for the second).
Emotions in the Everyday Life of a Dance School: Articulating Unspoken Values
Authors: Löytönen Teija 
Published: April 2012

In everyday thinking art is very often linked to emotion and, more generally, to a kind of emotional and spontaneous way of relating to the world that contrasts with the rational and controlled intellect that, for example, science is understood to cultivate. Emotion is also commonly linked, via bodily existence, to femininity and the private sphere—the home (see, for example, Heinämaa and Reuter 1994; Sihvola 1999. These conceptualizations reveal a tendency toward typically Western dichotomies between art and science, emotion and reason, body and mind, private and public, and woman and man (see also Domagalski 1999; Sandelans and Boudens 2000).Furthermore, working life and emotion have long been seen as separate; only emotion-free employees and institutions have been perceived as being efficient because emotional control, self-restraint, and rationality bolster stability and predictability in working life. Thus, emotions belong somewhere else. In fact, Lloyd Sandelans and Connie Boudens (2000, 48) note that we have had the habit of building special quarters for the exercise and display of emotion such as concert halls, movie theaters, football fields, and therapist's offices. This does not mean, however, that emotions can be eliminated from working life, as many studies on emotion at work have shown (Ashkanasy, Hartel, and Zerbe 2000; Fineman 2000, 2003; Hochschild 1983).
Improved structural model of Pb-dopedγ-Bi2O3: (Bi23.68Pb0.32)(Bi1.28Pb0.72)O38.48
Authors: Dapčević Aleksandra , Poleti Dejan , Karanović Ljiljana 
Published: April 2012

A polycrystalline single-phase sample with nominal composition Bi24PbO37was synthesized from Bi2O3and PbO by a high-temperature solid state reaction at 690 °C for 1.5 h. The compound adopts Bi12SiO20-type structure [cubic, space groupI23 (No. 197);a = 10.24957(3) Å] and was refined toRp = 7.96%,Rwp = 10.4%,Rexp = 8.43%,RB = 3.06%, andS = 1.23. The distributions of Pb2+and Bi3+over cationic sites based on the X-ray powder diffraction data were determined using a combination of the Rietveld refinement and bond valence calculations. The results showed that the asymmetric unit contains two mixed cation sites: the fully occupied 24fsite and the partly occupied 8csite, with the unit-cell content (Bi23.68Pb0.32)(Bi1.28Pb0.72)O38.48. The structural constraints favor a preference of Pb2+ion for the 8csite, i.e. only 1.3% of Bi3+is substituted by Pb2+at the 24fsite and 36% at the 8csite. At the 24fsite, the cations are surrounded by 5 + 2 or in a very small amount by 5 + 1 + 2 oxide ions, forming a base bicapped square pyramid or a bicapped highly deformed octahedron, respectively. At the 8csite, the cations with three oxide ions form a trigonal pyramid with the cations at the apex.
Glacial geomorphology and cosmogenic 10Be and 26Al exposure ages in the northern Dufek Massif, Weddell Sea embayment, Antarctica
Authors: Hodgson Dominic A. , Bentley Michael J. , Schnabel Christoph , Cziferszky Andreas , Fretwell Peter , Convey Peter , Xu Sheng 
Published: April 2012

AbstractWe studied the glacial geomorphology and geochronology of two ice-free valleys in the Dufek Massif (Antarctic Specially Protected Area 119) providing new constraints on past ice sheet thickness in the Weddell Sea embayment. 10Be and 26Al cosmogenic surface exposure dating provided chronological control. Seven glacial stages are proposed. These include an alpine glaciation, with subsequent (mid-Miocene?) over-riding by a warm-based ice sheet. Subsequent advances are marked by a series of minor drift deposits at 760 m altitude at > 1 Ma, followed by at least two later ice sheet advances that are characterized by extensive drift sheet deposition. An advance of plateau ice field outlet glaciers from the south postdated these drift sheets. The most recent advance involved the cold-based expansion of the ice sheet from the north at the Last Glacial Maximum, or earlier, which deposited a series of bouldery moraines during its retreat. This suggests at most a relatively modest expansion of the ice sheet and outlet glaciers dominated by a lateral ice expansion of just 2–3 km and maintaining a thickness similar to that of the northern ice sheet front. These observations are consistent with other reports of modest ice sheet thickening around the Weddell Sea embayment during the Last Glacial Maximum.
Possible multiple introductions ofCladonia borealisto King George Island
Authors: Park Chae Haeng , Jeong Gajin , Hong Soon Gyu 
Published: April 2012

AbstractMany lichens have extensive distributional ranges covering several climatic zones and are able to colonize extreme habitats, including high alpine and polar regions.Cladonia borealis, one of the dominant lichen species on King George Island, is a cosmopolitan species inhabiting polar, subpolar, and alpine areas. It is usually found on soil, humus, and mosses, and is morphologically highly diverse. To understand the phylogeographic history ofC. borealison King George Island, we compared specimens from there with specimens from Norway and Chile. We conducted phylogenetic and haplotype network analyses of the partial SSU, ITS1-5.8S-ITS2, and partial LSU rDNA sequences including intron sequences in LSU rRNA genes. Nuclear rDNA locus ofC. borealisfrom King George Island was separated into two monophyletic lineages. It is suggested that they originated in multiple independent introduction events after long-distance dispersal from other continents.
Evaluation of bactericidal effects of low‐temperature nitrogen gas plasma towards application to short‐time sterilization
Authors: Kawamura Kumiko , Sakuma Ayaka , Nakamura Yuka , Oguri Tomoko , Sato Natsumi , Kido Nobuo 
Published: April 2012

ABSTRACTTo develop a novel low‐temperature plasma sterilizer using pure N2 gas as a plasma source, we evaluated bactericidal ability of a prototype apparatus provided by NGK Insulators. After determination of the sterilizing conditions without the cold spots, the D value of the BI of Geobacillus stearothermophilus endospores on the filter paper was determined as 1.9 min. However, the inactivation efficiency of BI carrying the same endospores on SUS varied to some extent, suggesting that the bactericidal effect might vary by materials of sterilized instruments. Staphylococcus aureus and Escherichia coli were also exposed to the N2 gas plasma and confirmed to be inactivated within 30 min. Through the evaluation of bactericidal efficiency in a sterilization bag, we concluded that the UV photons in the plasma and the high‐voltage pulse to generate the gas plasma were not concerned with the bactericidal effect of the N2 gas plasma. Bactericidal effect might be exhibited by activated nitrogen atoms or molecular radicals.
Sex differences in habitat use by African elephants (Loxodonta africana) in the Okavango Delta, Botswana: is size really the deciding factor?
Authors: Evans Kate , Harris Stephen 
Published: April 2012

AbstractMany sexually dimorphic mammals show sexual segregation of habitat use. We studied habitat selection and use by male and female elephants in the Okavango Delta, and males of different ages and therefore sizes, to assess whether size was a driving force behind any sex differences in habitat selectivity. There was variation in habitat choices, with males preferring island vegetation and mopane woodland and avoiding grassland/floodplain and Terminalia woodland; females showed no selection for or against most habitats other than selecting for mopane woodland in the rainy season. Male habitat choice changed dramatically during the dry season, when resources were most limited and there was the least sexual difference in habitat selection. Females were more selective in the flood season, when access to resources was restricted. Contrary to other studies and the forage selection hypothesis, males showed greater habitat selectivity than females, but age, and therefore size, did not affect their habitat selection. Whilst our data suggested that males were superior competitors, we could not discount that females excluded males from preferred habitats. In the Okavango Delta, habitat selection by male elephants may be more dependent on social groupings, and hence the decisions of others, than individual size and energetic requirements.
Challenging behaviour in out‐of‐home care: use of attachment ideas in practice
Authors: McLean Sara , Riggs Damien , Kettler Lisa , Delfabbro Paul 
Published: April 2012

ABSTRACTChildren in out‐of‐home care that demonstrate challenging behaviour are often thought of as ‘attachment disordered’. Our understanding of what this might mean for practice is not well developed. In this study, 92 South Australian stakeholders were interviewed about how they understood extremely challenging behaviour amongst school‐age children in out‐of‐home care. Participants consistently described behaviour as arising from attachment difficulties. Despite this, there were a variety of ways that a child's attachment needs were conceptualized, which appeared to be inconsistent with contemporary attachment theory. Thematic analysis yielded four implicit views about children's attachment: attachment as capacity that is limited, attachment as skill that children can learn and transfer to other relationships, attachment as unachievable for some children and an idealized view of attachment as a close and trusting relationship. These possible misconceptions about attachment and attachment needs and their relationship to the development of challenging behaviour are discussed in terms of attachment informed research and theory. The possible implications for placement practice and policy for children in out‐of‐home care are discussed.