bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the thickness on the properties of erbium‐doped silicon‐rich silicon oxide thin films
Authors: Cueff Sébastien , Labbé Christophe , Cardin Julien , Hijazi Khalil , Doualan Jean‐Louis , Jambois Olivier , Garrido Blas , Rizk Richard 
Published: January 2011

AbstractThe present study examines the influence of the layer thickness on the emission of Er ions coupled to Si nanoclusters within a silica matrix obtained by magnetron co‐sputtering at two typical temperatures (ambient and 500 °C. Such an investigation is essential to optimise the material for specific applications, inasmuch as thin layers of tens of nm are requested for electrically‐excited devices, while much thicker films (≥ 1 µm) are necessary for optically‐excited waveguides, lasers, etc. The Er PL was detected from as‐deposited samples with significant intensity for that grown at 500 °C. This PL improves with annealing and also with the layer thickness, up to a factor 4 when the thickness is increased from few tens to more than 1.3 µm.The origin of this behaviour seems to lie in some limiting factors related to the film thinness, such as barriers for nucleation and growth of sensitizers (Si‐ncs), stresses affecting the onset of phase separation and then the formation of Si‐ncs. To favour the growth of Si‐ncs in films as thin as tens of nm, the increase of the amount of Si excess was found to be necessary to enhance the Er PL through an increase of the density of Si‐ncs and, therefore, the coupling with Er ions. Such an enrichment with Si offers an additional advantage of favouring the injection and transport of carriers by electrical excitation (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the role of non‐bridging oxygen centers in the red luminescence emission from silicon nanocrystals
Authors: Borsella Elisabetta , D'Amato Rosaria , Fabbri Fabio , Falconieri Mauro , Trave Enrico , Bello Valentina , Mattei Giovanni , Nie Yaru , Wang Dayang 
Published: January 2011

AbstractThe process responsible for visible‐near infrared luminescence emission in Si nanostructures has been generating significant controversy for years. The debate has focused on whether light emission is originated by recombination of quantum confined excitons or by defects located at the surface. It is experimentally difficult to distinguish the two contributions since both are size‐dependent. Moreover, all the studies were performed on different systems and consequently the comparisons were not free from ambiguities. Here we relate the spectroscopic properties of pyrolytic Si nanocrystals, aged in air, and after complete conversion to amorphous silica by alkali etching‐assisted oxidation. The strong resemblance of the spectral and time decay behavior of the red PL emission in both systems (surface oxidized nanocrystalline Si and amorphous silica sample) indicates that this emission is dominated by defects in the silicon oxide. The strongly non‐exponential time behavior of the photo‐luminescence emission in both systems can be modeled as the sum of exponential decays from the emitting defects, thus ruling out the interpretation in terms of the so‐called “stretched exponential” decay. Using this model we also obtained the emission energy and inhomogeneous linewidth of the luminescent defects, allowing us to identify them as the non‐bridging oxygen hole centers. The emission energy of these defects depends strongly on their physical and chemical environment and can produce a shift apparently due to the size effect. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear optical response of hole–trion systems in quantum dots in tilted magnetic fields
Authors: Machnikowski Paweł , Kuhn Tilmann 
Published: January 2011

AbstractWe discuss, from a theoretical point of view, the four wave mixing spectroscopy on an ensemble of p‐doped quantum dots in a magnetic field slightly tilted from the in‐plane configuration. We describe the system evolution in the density matrix formalism. In the limit of coherent ultrafast optical driving, we obtain analytical formulas for the single system dynamics and for the response of an inhomogeneously broadened ensemble.The results are compared to the previously studied time‐resolved Kerr rotation spectroscopy on the same system. We show that the Kerr rotation and four wave mixing spectra yield complementary information on the spin dynamics (precession and damping). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nuclear spin‐polarization in single InGaAs quantum dots through electrical and optical spin‐injection in spin‐LEDs
Authors: Hetterich M. , Asshoff P. , Wüst G. , Merz A. , Kalt H. 
Published: January 2011

AbstractWe investigate nuclear spin polarization in a single InGaAs quantum dot via electrical injection of spinpolarized electrons in a spin‐injection light‐emitting diode. The Overhauser shift in the single‐dot electroluminescence is compared with results obtained for optical spin injection in the same structure.The results clearly demonstrate the possibility of efficient nuclear spin polarization by purely electrical means which might be useful for future spintronic applications. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energies of higher multipole vibrations of fullerenes in a semiclassical approach
Authors: Lamichhane K. , Brack M. , Winkler P. 
Published: January 2011

AbstractStarting with a brief description of the local current approximation (LCA) as previously applied to the photoionization cross section of C60, we discuss the results of higher multipole resonances of fullerene molecules. The comparison to data obtained from electron scattering experiments reveals the adequacy of the semiclassical approach as well as the collective nature of even high L resonances. Similar to the results of the dipole case, the coupling of surface and volume plasmons mode in C60 molecules is seen to shift the peaks slightly toward lower energies. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Currents in STSE education: Mapping a complex field, 40 years on
Authors: Pedretti Erminia , Nazir Joanne 
Published: January 2011

AbstractIt has been 40 years since science, technology, society, and environment (STSE) education first appeared in science education research and practice. Although supported among many educators worldwide, there is much confusion surrounding the STSE slogan. Widely differing discourses on STSE education and diverse ways of practicing, have led to an array of distinct pedagogical approaches, programs, and methods. We are left wondering how we might orient ourselves amid such a diversity of propositions. What does STSE look like in practice? What ideological orientations underpin its practice? In this paper, we review the research literature and educational practices in STSE education to (1) map out a typology of STSE education in the form of currents and (2) provide a heuristic that educators can use for critical analysis of discourses and practices in the field. We identify, explore, and critique six currents in STSE education: application/design, historical, logical reasoning, value‐centered, sociocultural, and socio‐ecojustice currents. We suggest that these currents may serve as a didactic tool for others, a framework that will assist educators in informing their own theoretical understandings, choices, and practices in the context of STSE education. © 2011 Wiley Periodicals, Inc. Sci Ed 95:601–626, 2011
Knowledge transfer in intra‐organization networks
Authors: Tang Fangcheng 
Published: January 2011

AbstractPast studies have suggested absorptive capacity plays very important role in knowledge transfer. However, less attention has been paid to the dual process of knowledge transfer, which covers knowledge dissemination and absorption. This study operationalizes the concept of disseminative capacity and analyses differences in disseminative capacity of network members. Theoretical analysis and simulation results showed that the sizes of network, knowledge transfer speed and disseminative capabilities and absorptive capabilities of the individuals in the network have effect on knowledge equilibrium of networks over time. Furthermore, the results showed that the more powerful is a dominant knowledge holder in the network, the quicker the network will converge to a specified knowledge state. Copyright © 2011 John Wiley & Sons, Ltd.
Decreased parvalbumin immunoreactivity in the cortex and striatum of mice lacking the CB1 receptor
Authors: Fitzgerald Megan L. , Lupica Carl R. , Pickel Virginia M. 
Published: January 2011

AbstractCortical and striatal regions of the brain contain high levels of the cannabinoid‐1 (CB1) receptor, the central neuronal mediator of activity‐dependent synaptic plasticity evoked by endocannabinoids. The expression levels of parvalbumin, a calcium‐binding protein found in fast‐spiking interneurons of both regions, may be controlled in part by synaptic activity during critical periods of development. However, there is currently no evidence that CB1 receptor expression affects parvalbumin levels in either cortical or striatal interneurons. To assess this possibility, we examined parvalbumin immunoreactivity in the dorsolateral striatum, primary motor cortex (M1), and prefrontal cortex (PFC) of CB1 knockout and wild‐type C57/BL6 mice. Quantitative densitometry showed a significant decrease in parvalbumin immunoreactivity within individual neurons in each of these regions of CB1 knockout mice relative to controls. A significantly lower density (number of cells per unit area) of parvalbumin‐labeled neurons was observed in the striatum, but not the cortical regions of CB1 knockout mice. These findings suggest that CB1 receptor deletion may elicit a compensatory mechanism for network homeostasis affecting parvalbumin‐containing cortical and striatal interneurons. Synapse, 2011. Published 2011 Wiley‐Liss, Inc.
Hypocretin1/OrexinA‐containing axons innervate locus coeruleus neurons that project to the Rat medial prefrontal cortex. Implication in the sleep‐wakefulness cycle and cortical activation
Authors: Cid‐Pellitero Esther Del , GarzÓN Miguel 
Published: January 2011

AbstractThe Hypocretin1/OrexinA (Hcrt1/OxA) neuropeptides are found in a group of posterolateral hypothalamus neurons and are involved in sleep‐wakefulness cycle regulation. Hcrt1/OxA neurons project widely to brainstem aminergic structures, such as the locus coeruleus (LC), which are involved in maintenance of wakefulness and EEG activation through intense projections to the medial prefrontal cortex (mPFC). Moreover, defects of the Hcrt1/OxA system are linked to narcolepsy, a disorder characterized by excessive diurnal hypersomnia and REM state disturbance. We aimed to determine whether Hcrt1/OxA neurons innervate LC neurons (noradrenergic and nonnoradrenergic) that project to the mPFC, thereby sustaining behavioral wakefulness. To assess this, we used retrograde tracing from mPFC injections and either Hcrt1/OxA or tyrosine hydroxylase (TH) immunohistochemical labeling in single sections of rat LC. The retrograde tracer Fluorogold (FG) was microinjected into mPFC and, at optimal survival periods, sections through the LC were processed for dual immunolabeling of anti‐FG and either anti‐Hcrt1/OxA or anti‐TH antisera. Many LC neurons projecting to mPFC were nonnoradrenergic. Electron microscopy revealed a prominent localization of Hcrt1/OxA in unmyelinated axons and axon boutons (varicosities and axon terminals) within the LC. Hcrt1/OxA‐immunoreactive axon boutons frequently apposed (104/1907) or made asymmetric excitatory‐type synapses (60/1907) with FG‐immunolabeled dendrites, indicating that Hcrt1/OxA can modulate the activity of LC neurons with cortical projections. Our results show that Hcrt1/OxA hypothalamic neurons likely excite LC neurons that project to the mPFC, and thus activate EEG and facilitate wakefulness. In narcoleptics, who are deficient in Hcrt1/OxA, impairment of this Hcrt1/OxA hypothalamic input to LC might contribute to the appearance of excessive daytime sleepiness. Synapse , 2011. © 2011 Wiley‐Liss, Inc.
Implementing Sentinel Lymph Node Biopsy Programs in Developing Countries: Challenges and Opportunities
Authors: Keshtgar Mohammed , Zaknun John J. , Sabih Durre , Lago Graciela , Cox Charles E. , Leong Stanley P. L. , Mariani Giuliano 
Published: January 2011

AbstractBackgroundSentinel lymph node biopsy (SLNB) is the accepted standard of care in early‐stage breast cancer and cutaneous melanoma. This technology is accurate for nodal staging and determining the prognosis of these patients. There are several randomized controlled trials confirming the accuracy of this technique and confirming its role in reducing morbidity and improving quality of life. It is also gaining increased acceptance in the management of other solid tumors. Despite the established benefits of SLNB as a minimally invasive approach for nodal staging, the procedure is still underutilized in many developing countries.MethodsThe Human Health Division of the International Atomic Energy Agency (IAEA) convened advisory meetings with panels of multidisciplinary experts from different backgrounds with the remit to analyze the difficulties encountered by developing countries in establishing a successful SLNB program. The other remit of the panel was to recommend an effective program based on existing evidence that can be adapted and implemented in developing countries. The experience of some members of the panel in the training for this technique in Asia, Latin America, and Africa provided the insight required for the development of a comprehensive and structured program. The panel included recommendations on the technical aspects of the procedure, as well as a comprehensive training program, including theoretical teaching, practical training in surgical skills, laboratories, and hands‐on proctored learning. Particular emphasis was placed on in‐built quality assurance requirements to ensure that this powerful staging investigation is implemented with the highest possible standard in the management of cancer patients, with the lowest false negative rate.ConclusionsIt is hoped that this article will be a useful resource for our colleagues planning to establish a SLNB program.
Quality Improvement as a Tool for Translating Evidence Based Interventions Into Practice: What the Youth Violence Prevention Community can Learn from Healthcare
Authors: Knox Lyndee M. , Aspy Cheryl B. 
Published: January 2011

AbstractHealth care has been working for the past 2 decades to improve the translation of evidence based practice (EBPs) into care. The strategies used to facilitate this, and lessons learned, can provide useful models for similar work taking place in youth violence prevention. This article discusses the history of evidence translation in health care, reviews key strategies used to support translation of evidence based practice into care, and suggests lessons learned that may be useful to similar efforts in youth violence prevention and intervention services.
Impact of overweight and glucose tolerance on postprandial responses to high- and low-glycaemic index meals
Authors: Perälä Mia-Maria , Hätönen Katja A. , Virtamo Jarmo , Eriksson Johan G. , Sinkko Harri K. , Sundvall Jouko , Valsta Liisa M. 
Published: January 2011

The beneficial effects of a low-glycaemic index (GI) meal on postprandial glucose and insulin levels have been demonstrated. However, limited data are available on the impact of overweight and glucose tolerance on postprandial responses to different GI meals. Our aim was to study the effects of physiological characteristics on postprandial glucose, insulin and lipid responses and the relative glycaemic response (RGR) of a low-GI (LGI) and a high-GI (HGI) meal. We recruited twenty-four normal-weight and twenty-four overweight subjects, twelve with normal glucose tolerance (NGT) and twelve with impaired glucose tolerance (IGT) in each group. Both test meals were consumed once and the glucose reference twice. Blood glucose and insulin were measured in the fasting state and over a 2 h period after each study meal, and TAG and NEFA were measured in the fasting state and over a 5 h period. The glucose responses of subjects with IGT differed significantly from those of subjects with NGT. The highest insulin responses to both meals were observed in overweight subjects with IGT. Physiological characteristics did not influence TAG or NEFA responses or the RGR of the meals. The LGI meal resulted in lower glucose (P < 0·001) and insulin (P < 0·001) responses, but higher TAG responses (P < 0·001), compared with the HGI meal. The GI of the meals did not affect the NEFA responses. In conclusion, the LGI meal causes lower glucose and insulin responses, but higher TAG responses, than the HGI meal. The RGR of the meals does not differ between normal-weight and overweight subjects with NGT or IGT.
Iodine intakes of 100–300 μg/d do not modify thyroid function and have modest anti-inflammatory effects
Authors: Soriguer Federico , Gutiérrez-Repiso Carolina , Rubio-Martin Elehazara , Linares Francisca , Cardona Isabel , López-Ojeda Jaime , Pacheco Marta , González-Romero Stella , Garriga Maria J. , Velasco Ines , Santiago Piedad , García-Fuentes Eduardo 
Published: January 2011

Little information is available as to whether doses of iodide similar to those recommended in clinical practice for the prevention of iodine deficiency in pregnant women affect thyroid function. The aim of the present study was to analyse whether doses of iodide can affect thyroid function in adults, and evaluate its effect on plasma markers of oxidative stress, inflammation and acute-phase proteins. A total of thirty healthy volunteers (ten men and twenty women) with normal thyroid function were randomly assigned to three groups (n10). Each group received a daily dose of 100, 200 or 300 μg of iodide in the form of KI for 6 months. Free tetraiodothyronine (FT4) levels at day 60 of the study were higher in the groups treated with 200 and 300 μg (P = 0·01), and correlated with the increase in urinary iodine (r0·50,P = 0·007). This correlation lost its significance after adjustment for the baseline FT4. The baseline urinary iodine and FT4 correlated positively with the baseline glutathione peroxidase. On day 60, urinary iodine correlated with C-reactive protein (r0·461,P = 0·018), and free triiodothyronine correlated with IL-6 (r− 0·429,P = 0·025). On day 60, the changes produced in urinary iodine correlated significantly with the changes produced in α1-antitrypsin (r0·475,P = 0·014) and ceruloplasmin (r0·599,P = 0·001). The changes in thyroid-stimulating hormone correlated significantly with the changes in α1-antitrypsin (r− 0·521,P = 0·005) and ceruloplasmin (r− 0·459,P = 0·016). In conclusion, the administration of an iodide supplement between 100 and 300 μg/d did not modify thyroid function in a population with adequate iodine intake. The results also showed a slight anti-inflammatory and antioxidative action of iodide.
Genetic and morphological variation in Echinorhynchus gadi Zoega in Müller, 1776 (Acanthocephala: Echinorhynchidae) from Atlantic cod Gadus morhua L.
Authors: Sobecka E. , Szostakowska B. , MacKenzie K. , Hemmingsen W. , Prajsnar S. , Eydal M. 
Published: January 2011

AbstractPrevious studies have shown considerable variability in morphological features and the existence of genetically distinct sibling species in the acanthocephalan Echinorhynchus gadi Zoega in Müller, 1776. The aim of the present study was to follow up and extend those earlier studies by using a combination of DNA analysis and morphometrics to investigate differences between samples of E. gadi from Atlantic cod Gadus morhua L. caught at five fishing grounds in the Baltic Sea and three in different parts of the North Atlantic. Twelve morphological features were measured in 431 specimens of E. gadi, 99 individuals were studied by polymerase chain reaction-restriction fragment length polymorphosm (PCR-RFLP), and selected PCR products were sequenced. The molecular analyses showed the nucleotide sequences of E. gadi rDNA from cod caught at all the sampling sites to be identical. The comparative morphological study, in contrast, revealed significant differences between samples of E. gadi from different sampling sites and showed the separation of E. gadi into two groups corresponding approximately to the systematic classification of cod into the two subspecies, Atlantic G. morhua morhua and Baltic G. morhua callarias. The E. gadi infrapopulation size had a significant effect on some of the morphological features. The results are discussed in relation to cod population biology, the hydrography of the study area and the history of the Baltic Sea formation.
Tradition, modernity and the supernatural swing: re-reading ‘primitivism’ in Hugues Panassié's writing on jazz
Authors: Perchard Tom 
Published: January 2011

AbstractBefore WWII, Hugues Panassié (1912–1974) was Europe's leading critical authority on jazz, and by the time of his death he had published a dozen books on jazz music and been President of the Hot-club de France for over 40 years. Yet despite this life's worth of efforts made in jazz's name, Panassié's reputation is no longer a good one: pointing to the fantasies of black exceptionalism and Noble Savagery present in his work, historians have tended to dismiss the critic as a racist primitivist, one in thrall to that contemporarynegrophiliemost familiar today from early-century Parisian visual art. Indeed Panassié used the term ‘primitive’ himself, and positively. But this article traces the ultra-conservative writer's intellectual and religious formation to show that, rather than contemporarynegrophilie, it was a religious and cultural heritage quite distant from the modern European encounter with blackness that first informed Panassié's primitivism. Although this re-reading does not aim to ‘rehabilitate’ someone who remains a troublesome and reactionary figure, the article nevertheless goes on to explore how, in his primitivist rejection of European modernism, Panassié sometimes pre-empts important arguments made by the postmodern jazz scholarship that would seem to marginalise the critic's historical contributions.
Youssou N'Dour's Sant Yàlla/Egypt: a musical experiment in Sufi modernity
Authors: McLaughlin Fiona 
Published: January 2011

AbstractIn collaboration with the Cairene composer Fathy Salama, Youssou N'Dour released an album that appeared in Dakar in 2003 as Sant Yàlla (‘Praise God’), and internationally in 2004 as Egypt. Sung in Wolof to the accompaniment of an Egyptian orchestra, the album consists of a suite of eight interrelated pieces, seven of which are praise songs to Senegalese Sufi shaykhs, while the remaining piece praises God, the Prophet Mohammed, and some important Mauritanian shaykhs. In this essay I argue that in bringing Senegalese Islam to the international arena, N'Dour uses his stature as a world-class musician to both articulate and participate in the creation of a Sufi modernity, namely a way of being a Sufi Muslim in a globalised world. In addition to being a personal journey for Youssou N'Dour, both musically in its orientation towards the East rather than the West, and in his own religious faith, Sant Yàlla/Egypt also echoes many of the current preoccupations of Muslim intellectuals and artists as they seek to renew and reinterpret their own local religious traditions for a global audience.