bluuebunny/crossref_metadata_2025 huggingface dataset:
Spoken word recognition in adolescents with autism spectrum disorders and specific language impairment
Authors: LOUCAS TOM , RICHES NICK , BAIRD GILLIAN , PICKLES ANDREW , SIMONOFF EMILY , CHANDLER SUSIE , CHARMAN TONY
Published: December 2011

Spoken word recognition, during gating, appears intact in specific language impairment (SLI). This study used gating to investigate the process in adolescents with autism spectrum disorders plus language impairment (ALI). Adolescents with ALI, SLI, and typical language development (TLD), matched on nonverbal IQ listened to gated words that varied in frequency (low/high) and number of phonological onset neighbors (low/high density). Adolescents with ALI required more speech input to initially identify low-frequency words with low competitor density than those with SLI and those with TLD, who did not differ. These differences may be due to less well specified word form representations in ALI.
Weakening resistance: Progress toward the low back merger in New York State
Authors: Dinkin Aaron J.
Published: December 2011

This paper examines the status of the low back caught-cot merger in Upstate New York. Most of this region is subject to the Northern Cities Shift (NCS) and therefore, according to Labov, Ash, and Boberg (2006), ostensibly “resists” the spread of this merger. It is found that the phonology of this region is indeed trending toward the merger in apparent time, in terms of both phonetic distance between the two phonemes and speakers' explicit judgments. It is argued that the fronting of the cot vowel in the NCS region is not sufficient to withstand the spread of the merger because fronting a low vowel is a “reversible” sound change (Labov, 2010). It is further argued that the expansion of a merger to new communities may take place indirectly, through launching a sound change in the direction of merger rather than causing merger to take place immediately in the new community.
Cognitive and social forces in dialect shift: Gradual change in London Asian speech
Authors: Sharma Devyani , Sankaran Lavanya
Published: December 2011

This study examines the retention of a non-native dialect feature by British Asians in London. We examine the use of one Punjabi feature (t-retroflexion) and one British feature (t-glottaling) across three groups: first-generation non-native immigrants and two age groups of second-generation British Asians. Cognitively oriented models predict that non-native features will either be innately blocked (Chambers, 2002) or reallocated by native generations. A socially oriented model allows for more gradual change. Contrary to the cognitive view, the older second generation neither blocks nor clearly reallocates use oft-retroflexion; they closely mirror the first generation's non-native use. However, they simultaneously control nativeliket-glottaling, reflecting a robust bidialectal ability. It is the younger second generation who exhibit focused reallocation in the form and function oft-retroflexion. This 20-year lag corresponds to major changes in demographics and race relations in the community over 5 decades. The study shows that acquisition of the local dialect and retention of exogenous features should be seen as independently constrained rather than as mutually exclusive.
Characterising the disordered state of block copolymers: Bifurcations of localised states and self-replication dynamics
Authors: GLASNER KARL B.
Published: December 2011

Above the spinodal temperature for micro-phase separation in block co-polymers, asymmetric mixtures can exhibit random heterogeneous structure. This behaviour is similar to the sub-critical regime of many pattern-forming models. In particular, there is a rich set of localised patterns and associated dynamics. This paper clarifies the nature of the bifurcation diagram of localised solutions in a density functional model ofA−Bdiblock mixtures. The existence of saddle-node bifurcations is described, which explains both the threshold for heterogeneous disordered behaviour as well the onset of pattern propagation. A procedure to generate more complex equilibria by attaching individual structures leads to an interwoven set of solution curves. This results in a global description of the bifurcation diagram from which dynamics, in particular self-replication behaviour, can be explained.
CAN WE POSSIBLY SUBSCRIBE TO BOTH LIBERTY AND EQUALITY AT ONE AND THE SAME TIME?
Authors: Subramanian S.
Published: December 2011

A ‘good society’ is one which is governed by a number of prized social virtues. Amongst these virtues, surely, must be counted a deference to the values of personal liberty and inter-personal equity. (These, after all, are two of the three values embodied in the French Revolution's stirring exhortation to ‘Liberty, Equality, and Fraternity’!) In urging, or professing, an acceptance of these values, there is the implicit judgment that the acceptance entails no possible problem of internal coherence or logical consistency. In this small essay, it will be shown that the apparently unproblematic judgment just mentioned could prove to be suspect. In particular, the reader is invited to consider that there are plausible, but mutually incompatible, ways in which the principles of ‘liberty’ and ‘equity’ can be formulated. The essay draws on the conventions and methods of a body of knowledge called ‘social choice theory’, which lies at the intersection of philosophy, political science, and economics.
In Memoriam: Gisbert Winnewisser
Authors: Herbst Eric , Encrenaz Pierre , Bachiller Rafael
Published: December 2011

Gisbert Winnewisser, emeritus Professor of Physics at the University of Köln, passed away in March 2011 after a long illness. His dedication to molecular spectroscopy in the laboratory and in the interstellar medium, coupled with his very influential voice for molecular science will be extremely difficult to replace.
Chemical Evolution of a Protoplanetary Disk
Authors: Semenov Dmitry A.
Published: December 2011

In this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition of gas and dust in these systems are presented. Strong variations of temperature, density, high-energy radiation intensities in these disks, both radially and vertically, result in a peculiar disk chemical structure, where a variety of processes are active. In hot, dilute and heavily irradiated atmosphere only the most photostable simple radicals and atoms and atomic ions exist, formed by gas-phase processes. Beneath the atmosphere a partly UV-shielded, warm molecular layer is located, where high-energy radiation drives rich ion-molecule and radical-radical chemistry, both in the gas phase and on dust surfaces. In a cold, dense, dark disk midplane many molecules are frozen out, forming thick icy mantles where surface chemistry is active and where complex polyatomic (organic) species are synthesized. Dynamical processes affect disk chemical composition by enriching it in abundances of complex species produced via slow surface processes, which will become detectable with ALMA.
The Diffuse Interstellar Bands: an Elderly Astro-Puzzle Rejuvenated
Authors: Cox Nick L. J.
Published: December 2011

The interstellar medium constitutes a physically and chemically complex component of galaxies and is important in the cycle of matter and the evolution of stars. From various spectroscopic clues we now know that the interstellar medium is rich in organic compounds. However, identifying the exact nature of all these components remains a challenge. In particular the identification of the so-called diffuse band carriers has been alluding astronomers for almost a century.

In recent decades, observational, experimental and theoretical advances have rapidly lead to renewed interest in the diffuse interstellar bands (DIBs). This has been instigated partly by their perceived relation to the infrared aromatic emission bands, the UV extinction bump and far-UV rise, and the growing number of (small) organic molecules identified in space.

This chapter gives an overview of the observational properties and behaviour of the DIBs, and their presence throughout the Universe. I will highlight recent progress in identifying their carriers and discuss their potential as tracers and probes of (extra)-Galactic ISM conditions.
Molecules in Supernova Ejecta
Authors: Cherchneff Isabelle , Sarangi Arkaprabha
Published: December 2011

The first molecules detected at infrared wavelengths in the ejecta of a Type II supernova, namely SN1987A, consisted of CO and SiO. Since then, confirmation of the formation of these two species in several other supernovae a few hundred days after explosion has been obtained. However, supernova environments appear to hamper the synthesis of large, complex species due to the lack of microscopically-mixed hydrogen deep in supernova cores. Because these environments also form carbon and silicate dust, it is of importance to understand the role played by molecules in the depletion of elements and how chemical species get incorporated into dust grains. In the present paper, we review our current knowledge of the molecular component of supernova ejecta, and present new trends and results on the synthesis of molecules in these harsh, explosive events.
Conference Summary
Authors: Black John H.
Published: December 2011

By any measure, IAU Symposium 280 has been an outstanding success: more than 400 participants represented at least 30 countries with 74 presentations and more than 300 posters. Beyond these numbers, it is evident that the cross-disciplinary field of astrochemistry is flourishing with excellent prospects for growth in the future. We have enjoyed the excitement of new, unexpected results from the Herschel Space Observatory and eagerly await new opportunities and facilities that will arise in the coming months and years.
Neue Entwicklungen in der Adoleszenzpsychiatrie und -psychotherapie
Authors: Fegert Jörg M. , Freyberger Harald J.
Published: December 2011

Zusammenassung.Über einen langen Zeitraum wurden in Forschung, Diagnostik und Therapie die spezifischen mit der Adoleszenz verbundenen Herausforderungen vernachlässigt. Dabei treten etwa die Hälfte der psychischen Störungen erstmalig in der Jugendzeit auf und zeigen eine hohe Bedeutung in den späteren Abschnitten des Erwachsenenalters. Zum Beispiel beginnen die nicht-suizidale Selbstverletzung und die Suizidalität bzw. das ADHS in der Adoleszenz. Insbesondere das ADHS ist eine Störung der gesamten Lebensspanne, die zu klinisch bedeutsamen Funktionseinschränkungen im täglichen Leben führt und durch komorbide Störungen kompliziert wird. Die Fragen in Zuammenhang mit adoleszenter Entwicklung haben damit Implikationen für Therapeuten, Hilfesysteme, die Gesellschaft und die Politik.
Joint Modeling of Longitudinal Change and Survival
Authors: Muniz Terrera Graciela , Piccinin Andrea M. , Matthews Fiona , Hofer Scott M.
Published: December 2011

Joint longitudinal-survival models are useful when repeated measures and event time data are available and possibly associated. The application of this joint model in aging research is relatively rare, albeit particularly useful, when there is the potential for nonrandom dropout. In this article we illustrate the method and discuss some issues that may arise when fitting joint models of this type. Using prose recall scores from the Swedish OCTO-Twin Longitudinal Study of Aging, we fitted a joint longitudinal-survival model to investigate the association between risk of mortality and individual differences in rates of change in memory. A model describing change in memory scores as following an accelerating decline trajectory and a Weibull survival model was identified as the best fitting. This model adjusted for random effects representing individual variation in initial memory performance and change in rate of decline as linking terms between the longitudinal and survival models. Memory performance and change in rate of memory decline were significant predictors of proximity to death. Joint longitudinal-survival models permit researchers to gain a better understanding of the association between change functions and risk of particular events, such as disease diagnosis or death. Careful consideration of computational issues may be required because of the complexities of joint modeling methodologies.
Improvement of Cognitive Function after Physical Movement Training in Institutionalized Very Frail Older Adults with Dementia
Authors: Thurm Franka , Scharpf Andrea , Liebermann Nadine , Kolassa Stephan , Elbert Thomas , Lüchtenberg Dietmar , Woll Alexander , Kolassa Iris-Tatjana
Published: December 2011

Physical exercise has positive effects on cognitive functioning in both healthy older adults and ambulatory older adults with dementia. The present study investigated whether a 10-week multimodal movement intervention conducted in the seated position can slow cognitive deterioration in demented and physically very frail nursing-home residents. Our analysis revealed that training participants showed no further overall cognitive deterioration throughout the study and a significant improvement in the ADAS-Cog orientation/praxis subscore (p = .04). In contrast, the control group demonstrated a significant decline in the ADAS-Cog sum score (p = .02). These results might be of relevance for geriatric practice since they indicate that a short-term physical intervention – even in the seated position – can decelerate cognitive decline and dementia despite physical frailty.
NIE-Richtlinien zur Gender Fairness von Interessentests
Authors: Wetzel Eunike , Hell Benedikt
Published: December 2011

Mithilfe der Richtlinien des National Institute of Education (NIE) wurden 15 deutschsprachige Interessentests hinsichtlich ihrer Gender Fairness bewertet. Dazu wurde untersucht, ob im Testmaterial, Manual und Begleitmaterial die Forderungen der NIE-Richtlinien umgesetzt wurden. Bezüglich des Testmaterials werden die meisten Verfahren der Forderung gerecht, dass für Frauen und Männer dasselbe Testmaterial verwendet und Berufsbezeichnungen geschlechtsneutral formuliert sein sollten. Betreffend der Gender Fairness des Manuals und Begleitmaterials dagegen werden die Forderungen der NIE-Richtlinien nur vereinzelt erfüllt. Insgesamt erfüllt der Explorix die größte Anzahl der Forderungen. In Anbetracht des Einflusses, den die Ergebnisse von Interessentests auf Berufswahlentscheidungen haben, wäre es wünschenswert, dass Testautoren und Verleger Schritte unternähmen, um die Gender Fairness ihrer Verfahren sicherzustellen.
Intelligenz, Persönlichkeit, Einkommen und Fremdbeurteilungen der Leistung in sozialen Berufen
Authors: Blickle Gerhard , Kramer Jochen
Published: December 2011

Soziale Berufe (sensu KldB 92, Vh 86; Statistisches Bundesamt, 1992 , S. 51) bilden ein wesentliches Segment des Arbeitsmarktes in Deutschland. Gleichwohl liegen bisher keine Befunde dazu vor, wie Intelligenz und Persönlichkeitsmerkmale mit Leistungsbeurteilungen und Einkommen in diesem Bereich zusammenhängen. Dies wurde in der vorliegenden Studie bei 142 erwerbstätigen Personen aus sozialen Berufen untersucht. Die Leistung wurde auf den Dimensionen aufgabenbezogene Leistung, Arbeitseinsatz und Sozialverhalten durch Vorgesetzte oder Kollegen beurteilt. Kontrolliert wurden Alter, Geschlecht und Bildung. Die Allgemeine Intelligenz stand in Beziehung zum Einkommen, nicht aber zur aufgabenbezogenen Leistung. Gewissenhaftigkeit stand in Beziehung zur aufgabenbezogenen Leistung und zum Arbeitseinsatz. Das Sozialverhalten sowie der Arbeitseinsatz standen in Beziehung zum Persönlichkeitsmerkmal Verträglichkeit. Diese Befunde liefern Hinweise darauf, dass Persönlichkeitstests bei der Personalauswahl auch in diesem Berufsbereich nutzbringend eingesetzt werden können. Für Intelligenztests konnte dies nicht nachgewiesen werden. Weitere theoretische und praktische Implikationen der Befunde sowie Stärken und Grenzen der Studie werden diskutiert.
Vereinbarkeit von Erwerbsarbeit und Privatleben
Authors: Brauchli Rebecca , Hämmig Oliver , Güntert Stefan , Bauer Georg F. , Wehner Theo
Published: December 2011

Die Studie verbindet zwei bisher getrennt voneinander beforschte Themenkreise: Die Vereinbarkeit beziehungsweise Unvereinbarkeit von Erwerbsarbeit, Privatleben (subsumiert unter dem Begriff Work-Life Conflict (WLC)) und Freiwilligentätigkeit. Dabei verfolgt sie zwei Ziele. Erstens wird untersucht, inwiefern Freiwilligentätigkeit an der Schnittstelle zwischen Erwerbsarbeit und Privatleben relevant ist, indem geprüft wird, wie und ob Freiwilligentätigkeit und WLC zusammenhängen. Zweitens wird der Frage nachgegangen, ob Freiwilligentätigkeit eine Pufferfunktion bezüglich der ungünstigen Beziehung zwischen WLC und Gesundheit einnehmen kann. Durch die Analyse zweier Datensätze konnte gezeigt werden, dass Freiwilligentätigkeit in differenzierter Weise mit WLC zusammenhängt: Während der Work-to-Life Conflict umso kleiner ist, je häufiger jemand freiwillig tätig ist, ist der Life-to-Work Conflict umso größer, was–betrachtet man WLC als Ganzes–zu einem nicht-linearen Zusammenhang von WLC und Freiwilligentätigkeit führt, bei dem mittelhäufig freiwillig Tätige optimale, sprich geringe WLC-Werte aufweisen. Eine mögliche Pufferfunktion von Freiwilligentätigkeit konnte indes mit den vorliegenden Daten nicht nachgewiesen werden.
Continental‐scale water and energy flux analysis and validation for North American Land Data Assimilation System project phase 2 (NLDAS‐2): 2. Validation of model‐simulated streamflow
Authors: Xia Youlong , Mitchell Kenneth , Ek Michael , Cosgrove Brian , Sheffield Justin , Luo Lifeng , Alonge Charles , Wei Helin , Meng Jesse , Livneh Ben , Duan Qingyun , Lohmann Dag
Published: December 2011

This is the second part of a study on continental‐scale water and energy flux analysis and validation conducted in phase 2 of the North American Land Data Assimilation System project (NLDAS‐2). The first part concentrates on a model‐by‐model comparison of mean annual and monthly water fluxes, energy fluxes and state variables. In this second part, the focus is on the validation of simulated streamflow from four land surface models (Noah, Mosaic, Sacramento Soil Moisture Accounting (SAC‐SMA), and Variable Infiltration Capacity (VIC) models) and their ensemble mean. Comparisons are made against 28‐years (1 October 1979–30 September 2007) of United States Geological Survey observed streamflow for 961 small basins and 8 major basins over the conterminous United States (CONUS). Relative bias, anomaly correlation and Nash‐Sutcliffe Efficiency (NSE) statistics at daily to annual time scales are used to assess model‐simulated streamflow. The Noah (the Mosaic) model overestimates (underestimates) mean annual runoff and underestimates (overestimates) mean annual evapotranspiration. The SAC‐SMA and VIC models simulate the mean annual runoff and evapotranspiration well when compared with the observations. The ensemble mean is closer to the mean annual observed streamflow for both the 961 small basins and the 8 major basins than is the mean from any individual model. All of the models, as well as the ensemble mean, have large daily, weekly, monthly, and annual streamflow anomaly correlations for most basins over the CONUS, implying strong simulation skill. However, the daily, weekly, and monthly NSE analysis results are not necessarily encouraging, in particular for daily streamflow. The Noah and Mosaic models are useful (NSE > 0.4) only for about 10% of the 961 small basins, the SAC‐SMA and VIC models are useful for about 30% of the 961 small basins, and the ensemble mean is useful for about 42% of the 961 small basins. As the time scale increases, the NSE increases as expected. However, even for monthly streamflow, the ensemble mean is useful for only 75% of the 961 small basins.
A case study of observations of volcanic ash from the Eyjafjallajökull eruption: 2. Airborne and satellite radiative measurements
Authors: Newman Stuart M. , Clarisse Lieven , Hurtmans Daniel , Marenco Franco , Johnson Ben , Turnbull Kate , Havemann Stephan , Baran Anthony J. , O'Sullivan Debbie , Haywood Jim
Published: December 2011

An extensive set of airborne and satellite observations of volcanic ash from the Eyjafjallajökull Icelandic eruption are analyzed for a case study on 17 May 2010. Data collected from particle scattering probes and backscatter lidar on the Facility for Airborne Atmospheric Measurements (FAAM) BAe 146 aircraft allow estimates of ash concentration to be derived. Using radiative transfer simulations we show that airborne and satellite infrared radiances can be accurately modeled based on the in situ measured size distribution and a mineral dust refractive index. Furthermore, airborne irradiance measurements in the 0.3–1.7 μm range are well modeled with these properties. Retrievals of ash mass column loading using Infrared Atmospheric Sounding Interferometer (IASI) observations are shown to be in accord with lidar‐derived mass estimates, giving for the first time an independent verification of a hyperspectral ash variational retrieval method. The agreement of the observed and modeled solar and terrestrial irradiances suggests a reasonable degree of radiative closure implying that the physical and optical properties of volcanic ash can be relatively well constrained using data from state‐of‐the‐science airborne platforms such as the FAAM BAe 146 aircraft. Comparisons with IASI measurements during recent Grímsvötn and Puyehue volcanic eruptions demonstrate the importance of accurately specifying the refractive index when modeling the observed spectra.
Brain Lactate Metabolism: The Discoveries and the Controversies
Authors: Dienel Gerald A
Published: December 2011

Potential roles for lactate in the energetics of brain activation have changed radically during the past three decades, shifting from waste product to supplemental fuel and signaling molecule. Current models for lactate transport and metabolism involving cellular responses to excitatory neurotransmission are highly debated, owing, in part, to discordant results obtained in different experimental systems and conditions. Major conclusions drawn from tabular data summarizing results obtained in many laboratories are as follows: Glutamate-stimulated glycolysis is not an inherent property of all astrocyte cultures. Synaptosomes from the adult brain and many preparations of cultured neurons have high capacities to increase glucose transport, glycolysis, and glucose-supported respiration, and pathway rates are stimulated by glutamate and compounds that enhance metabolic demand. Lactate accumulation in activated tissue is a minor fraction of glucose metabolized and does not reflect pathway fluxes. Brain activation in subjects with low plasma lactate causes outward, brain-to-blood lactate gradients, and lactate is quickly released in substantial amounts. Lactate utilization by the adult brain increases during lactate infusions and strenuous exercise that markedly increase blood lactate levels. Lactate can be an ‘opportunistic’, glucose-sparing substrate when present in high amounts, but most evidence supports glucose as the major fuel for normal, activated brain.
Autophagy, mitochondria and oxidative stress: cross-talk and redox signalling
Authors: Lee Jisun , Giordano Samantha , Zhang Jianhua
Published: December 2011

Reactive oxygen and nitrogen species change cellular responses through diverse mechanisms that are now being defined. At low levels, they are signalling molecules, and at high levels, they damage organelles, particularly the mitochondria. Oxidative damage and the associated mitochondrial dysfunction may result in energy depletion, accumulation of cytotoxic mediators and cell death. Understanding the interface between stress adaptation and cell death then is important for understanding redox biology and disease pathogenesis. Recent studies have found that one major sensor of redox signalling at this switch in cellular responses is autophagy. Autophagic activities are mediated by a complex molecular machinery including more than 30 Atg (AuTophaGy-related) proteins and 50 lysosomal hydrolases. Autophagosomes form membrane structures, sequester damaged, oxidized or dysfunctional intracellular components and organelles, and direct them to the lysosomes for degradation. This autophagic process is the sole known mechanism for mitochondrial turnover. It has been speculated that dysfunction of autophagy may result in abnormal mitochondrial function and oxidative or nitrative stress. Emerging investigations have provided new understanding of how autophagy of mitochondria (also known as mitophagy) is controlled, and the impact of autophagic dysfunction on cellular oxidative stress. The present review highlights recent studies on redox signalling in the regulation of autophagy, in the context of the basic mechanisms of mitophagy. Furthermore, we discuss the impact of autophagy on mitochondrial function and accumulation of reactive species. This is particularly relevant to degenerative diseases in which oxidative stress occurs over time, and dysfunction in both the mitochondrial and autophagic pathways play a role.
Benefit of Combined Triiodothyronine (LT3) and Thyroxine (LT4) Treatment in Athyreotic Patients Unresponsive to LT4 Alone
Authors: Solter D. , Solter M.
Published: December 2011

Despite some reports, the usefulness of levothyroxine ( LT4) and levotriiodothyronine (LT3) combination therapy in hypothyroidism remains controversial. The objective of this paper is to study a benefit of additional LT3 in athyreotic patients who failed to normalize TSH on LT4 alone even with hyperthyroid serum T4 values.

In a survey of 200 athyreotic patients treated between 2006 and 2009, about 7% failed to normalize serum TSH levels following treatment with LT4, though serum T4 values in the hyperthyroid range were achieved. These patients (characterized by serum T4≥160 nmol/L and TSH≥5.0 mIU/L), were additionally treated with 10 μg b. i. d LT3. LT3 and LT4 combination therapy resulted in decreased serum TSH levels into the normal range (12.8 vs. 1.22 mIU/L; p<0.01) and reduced LT4 dose (153.3 vs. 117.5 μg; p<0.01) required for normalization of serum T4 values (170.6 vs. 123.3 nmol/L; p<0.01). Serum T3 values were higher (1.3 vs. 2.26 nmol/L; p<0.01) than those during monotherapy with LT4.

Our results indicate a subpopulation of athyreotic patients that could significantly benefit from combined LT4 + LT3 therapy in restoring normal TSH and thyroid hormone patterns. Further research should be undertaken to provide a genetic basis for these findings.
Interface trap density metrology from sub-threshold transport in highly scaled undoped Si n-FinFETs
Authors: Paul Abhijeet , Tettamanzi Giuseppe C. , Lee Sunhee , Mehrotra Saumitra R. , Collaert Nadine , Biesemans Serge , Rogge Sven , Klimeck Gerhard
Published: December 2011

Channel conductance measurements can be used as a tool to study thermally activated electron transport in the sub-threshold region of state-of-art FinFETs. Together with theoretical tight-binding (TB) calculations, this technique can be used to understand the dependence of the source-to-channel barrier height (Eb) and the active channel area (Saa) on three important parameters: (i) the gate bias (Vgs), (ii) the temperature, and (iii) the FinFET cross-section size. The quantitative difference between experimental and theoretical values that we observe can be attributed to the interface traps present in these FinFETs. Therefore, based on the difference between measured and calculated values of (i) Saa and (ii) |∂Eb/∂Vgs| (channel to gate coupling), two new methods of interface trap density (Dit) metrology are outlined. These two methods are shown to be very consistent and reliable, thereby opening new ways of analyzing in situ state-of-the-art multi-gate FETs down to the few nanometer width limit. Furthermore, theoretical investigation of the spatial current density reveals volume inversion in thinner FinFETs near the threshold voltage.
Vlasov simulation in multiple spatial dimensions
Authors: Rose Harvey A. , Daughton William
Published: December 2011

A long-standing challenge encountered in modeling plasma dynamics is achieving practical Vlasov equation simulation in multiple spatial dimensions over large length and time scales. While direct multi-dimension Vlasov simulation methods using adaptive mesh methods [M. Gutnic et al., Comput. Phys. Commun. 164, 214 (2004)] have recently shown promising results in two dimensions (2D) [J. W. Banks et al., Phys. Plasmas 18, 052102 (2011); B. I. Cohen et al., November 10, 2010, http://meetings.aps.org/link/BAPS.2010.DPP.NP9.142], in this paper, we present an alternative, the Vlasov multi dimensional (VMD) model, that is specifically designed to take advantage of solution properties in regimes when plasma waves are confined to a narrow cone, as may be the case for stimulated Raman scatter in large optic f# laser beams. Perpendicular grid spacing large compared to a Debye length is then possible without instability or loss of accuracy, enabling an order 10 decrease in required computational resources compared to standard particle in cell (PIC) methods in 2D, with another reduction of that order in 3D. Further advantage compared to PIC methods accrues in regimes where particle noise is an issue. VMD and PIC results in a 2D model of localized Langmuir waves are in qualitative agreement.
Variable angle magnetometry for exchange-coupled multilayers with in-plane and perpendicular anisotropy
Authors: Yakovlev N. L. , Sbiaa R. , Piramanayagam S. N.
Published: December 2011

Co/Pd multilayers, including exchange coupled structures with thin layers of Co with different exchange coupling strengths, were investigated using variable angle magnetometry. Hysteresis loops of perpendicular and in-plane components of magnetization were measured using two-axis vibrating sample magnetometer and variable angle magneto-optical Kerr effect system. Co/Pd multilayer structures have high perpendicular remanence and the magnetization reversal mechanism is mainly domain wall motion. For the systems with Co and Co/Pd multilayers, the magnetization reversals of high coercivity (Co/Pd) multilayer and low coercivity Co single layer were found to be independent, if the soft layer (Co) is thicker than 2 nm. In the samples with a high degree of exchange coupling, the magnetization of the multilayer has two components, normal and in-plane. The proportion between them varies with field strength and orientation of the sample. Taking this into account, it was possible to determine the anisotropy energy of the (Co/Pd) multilayer, which is in the range of 400–420 kJ/m3.
Paramagnetic defects in electron-irradiated yttria-stabilized zirconia: Effect of yttria content
Authors: Costantini Jean-Marc , Beuneu François , Morrison-Smith Sarah , Devanathan Ram , Weber William J.
Published: December 2011

We have studied the effect of the yttria content on the paramagnetic centers in electron-irradiated yttria-stabilized zirconia (ZrO2: Y3+) or YSZ. Single crystals with 9.5 mol % or 18 mol % Y2O3 were irradiated with electrons of 1.0, 1.5, 2.0, and 2.5 MeV. The paramagnetic center production was studied by X-band electron paramagnetic resonance (EPR) spectroscopy. The same paramagnetic centers were identified for both chemical compositions, namely two electron centers, i.e., (i) F+-type centers (involving singly ionized oxygen vacancies), and (ii) so-called T centers (Zr3+ in a trigonal symmetry site), as well as hole-centers. A strong effect is observed on the production of hole-centers that is strongly enhanced when doubling the yttria content. However, no striking effect is found on the electron centers (except the enhancement of an extra line associated with the F+-type centers). It is concluded that hole-centers are produced by inelastic interactions, whereas F+-type centers are produced by elastic collisions with no effect of the yttria content on the defect production rate. In the latter case, the threshold displacement energy (Ed) of oxygen is estimated from the electron-energy dependence of the F+-type center production rate, with no significant effect of the yttria content on Ed. An Ed value larger than 120 eV is found. This is supported by classical molecular dynamics (MD) simulations with a Buckingham-type potential that show Ed values for Y and O are likely to be in excess of 200 eV. Due to the difficulty in displacing O or Y atoms, the radiation-induced defects may alternatively be a result of Zr atom displacements for Ed = 80 ± 1 eV with subsequent defect rearrangement.
Impact of fluorine treatment on Fermi level depinning for metal/germanium Schottky junctions
Authors: Wu Jia-Rong , Wu Yung-Hsien , Hou Chin-Yao , Wu Min-Lin , Lin Chia-Chun , Chen Lun-Lun
Published: December 2011

CF4 plasma treatment on germanium (Ge) surface is proposed in this work to alleviate the strong Fermi level pinning between metal/Ge, and its effectiveness is also explored for n- and p-type Ge wafers. It is found that samples with CF4 plasma treatment reveal conduction behavior transition between Schottky and ohmic characteristics, a metal-work-function-dependent Schottky barrier height as well as modulated contact resistance, and these results confirm the depinning of Fermi level. This depinning can be explained by the effective capability in passivating dangling bonds at Ge surface through fluorine atoms and the formation of Ge-F binding with partial ionic property, both of which are helpful in decreasing the number of surface states and consequently release the pinning effect.
In situ microwave characterization of microwire composites under mechanical stress
Authors: Qin Faxiang , Brosseau C. , Peng H. X.
Published: December 2011

We present results of an experimental characterization of the dielectric properties and microwave absorption of rubber composite samples containing Fe4Co68.7Ni1B13Si11Mo2.3 amorphous microwires which are submitted to a low uniaxial tension. Measurements of the dielectric loss and microwave absorption as a function of strain over the frequency range of 300 MHz-6 GHz reveal that the uniaxial elongation randomly breaks wires at about 2.8% strain and this has for effect to decrease the loss factor for larger strain. Two possible mechanisms are identified to account for our observations, namely, the stress and shape effects. The ability to control this stretch breaking phenomenon will be instrumental to developing stress tunable microwire composites for sensing applications.
Ab initio based polarizable force field generation and application to liquid silica and magnesia
Authors: Beck Philipp , Brommer Peter , Roth Johannes , Trebin Hans-Rainer
Published: December 2011

We extend the program potfit, which generates effective atomic interaction potentials from ab initio data, to electrostatic interactions and induced dipoles. The potential parametrization algorithm uses the Wolf direct, pairwise summation method with spherical truncation. The polarizability of oxygen atoms is modeled with the Tangney-Scandolo interatomic force field approach. Due to the Wolf summation, the computational effort in simulation scales linearly in the number of particles, despite the presence of electrostatic interactions. Thus, this model allows to perform large-scale molecular dynamics simulations of metal oxides with realistic potentials. Details of the implementation are given, and the generation of potentials for SiO2 and MgO is demonstrated. The approach is validated by simulations of microstructural, thermodynamic, and vibrational properties of liquid silica and magnesia.
Study of 375 nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance
Authors: Huang Shih-Cheng , Shen Kun-Ching , Wuu Dong-Sing , Tu Po-Min , Kuo Hao-Chung , Tu Chia-Cheng , Horng Ray-Hua
Published: December 2011

High performance 375 nm ultraviolet (UV) InGaN/AlGaN light-emitting diodes (LEDs) were demonstrated with inserting a heavy Si-doped GaN transition layer by metal-organic chemical vapor deposition. From transmission electron microcopy (TEM) image, the dislocation densities were significantly reduced due to the existence of the heavily Si-doping growth mode transition layer (GMTL), which results in residual stress relaxation and 3D growth. The internal quantum efficiency (IQE) of the LEDs with GMTL was measured by power-dependent photoluminescence (PL) to be 40.6% higher than ones without GMTL. The GMTL leads to the superior IQE performance of LEDs not only in decreasing carrier consumption at nonradiative recombination centers but also in partially mitigating the efficiency droop tendency. When the vertical-type LED chips (size: 1 mm × 1 mm) was driven with a 350 mA injection current, the output powers of the LEDs with and without GMTL were measured to be 286.7 and 204.2 mW, respectively. A 40.4% enhancement of light output power was achieved. Therefore, using the GMTL to reduce dislocations would be a promising prospective for InGaN/AlGaN UV-LEDs to achieve high IQE.
Impact of fixed charge on metal-insulator-semiconductor barrier height reduction
Authors: Hu Jenny , Nainani Aneesh , Sun Yun , Saraswat Krishna C. , Philip Wong H.-S.
Published: December 2011

Recently, the insertion of ultrathin insulators to form metal-insulator-semiconductor (MIS) contacts has been used extensively to reduce the Schottky barrier height and to shift the Fermi level pinning. In this paper, we investigate the physical non-idealities of the ultrathin insulator in Al/Al2O3/n-GaAs MIS through stoichiometry, density, and bandgap measurements. These structural non-idealities electrically manifest as bulk and interface fixed charges that are found to contribute to the observed barrier height reduction. The effect of fixed charge has not been considered before, and when combined with the previously reported interface dipoles, it provides a more thorough understanding of the MIS contacts.
Dual beat-frequencies laser Doppler interferometer
Authors: Takita A. , Ebara H. , Fujii Y.
Published: December 2011

A dual beat-frequencies laser Doppler interferometer which can measure high speed back and forth motion is proposed and demonstrated. In this interferometer, the two frequencies, f1 and f2, emitted by a Zeeman laser are introduced into the signal beams. They are changed to f1′ and f2′ by Doppler shift fDoppler, which is proportional to the velocity of the object. The use of the two beat signals of |f1′ − f2| and |f1 − f2′| appearing at two photodetectors enables to measure the velocity over the limitation vc = λ(f1 − f2)/2.
Optical lattices of InGaN quantum well excitons
Authors: Chaldyshev V. V. , Bolshakov A. S. , Zavarin E. E. , Sakharov A. V. , Lundin W. V. , Tsatsulnikov A. F. , Yagovkina M. A. , Kim Taek , Park Youngsoo
Published: December 2011

We demonstrate optical Bragg lattices formed by quasi-two-dimensional excitons in periodic systems of the InGaN quantum wells separated by the GaN barriers. When the Bragg resonance and exciton-polariton resonance are tuned to each-other, the medium exhibits an exciton-mediated resonantly enhanced optical Bragg reflection. The enhancement factor appeared to be larger than 2 for the system of 60 quantum wells. Owing to a high binding energy and oscillator strength of the excitons in InGaN quantum wells, the resonant enhancement was achieved at room temperature.
Hybrid magneto-optical mode converter made with a magnetic nanoparticles-doped SiO2/ZrO2 layer coated on an ion-exchanged glass waveguide
Authors: Amata Hadi , Royer François , Choueikani Fadi , Jamon Damien , Parsy François , Broquin Jean-Emmanuel , Neveu Sophie , Jacques Rousseau Jean
Published: December 2011

This paper describes the possibility to achieve a TE-TM mode conversion in a magneto-optical hybrid waveguide operating at λ = 1550 nm. This hybrid device is made by coating a SiO2/ZrO2 layer doped with magnetic nanoparticles on an ion-exchanged glass waveguide. Soft annealing (90 °C) and UV treatment, both compatible with the ion exchange process, have been implemented to finalize the magneto-optical film. Optical characterizations that have been carried out demonstrated the efficiency of these hybrid structures in terms of lateral confinement and mode conversion. Indeed, TE to TM mode conversion has been observed when a longitudinal magnetic field is applied to the device. The amount of this conversion is discussed taking into account the distribution of light between the layer and the guide, and the modal birefringence of the structure.
Recovery dynamics of rainfed winter wheat after livestock grazing 2. Light interception, radiation-use efficiency and dry-matter partitioning
Authors: Harrison Matthew T. , Evans John R. , Dove Hugh , Moore Andrew D.
Published: December 2011

Grazing of cereal crops reduces canopy light interception and could potentially reduce biomass production and grain yields. Alternatively, defoliation after canopy closure may increase light penetration and enhance radiation-use efficiency (RUE, shoot dry matter produced per unit light intercepted). Changes in dry matter partitioning following grazing may also ameliorate grain yield penalties. Experiments with rainfed winter wheat were conducted near Canberra, Australia, to investigate the effect of different intensity or duration of grazing on two cultivars. Grazing reduced leaf area index (LAI), light interception and growth rates by up to 90% but did not affect overall RUE. Although grazing caused significant reductions in cumulative light interception and total dry matter accumulation, it did not affect grain yields because grazed crops had delayed phenological development, allowing increased partitioning of shoot dry matter to spikes. Grazing reduced stem dry matter accumulation and consequently decreased the amount of stem assimilate available for retranslocation to kernels by up to 75%. However, by delaying crop ontogeny, grazing prolonged green area duration after anthesis and thereby increased the supply of assimilates from current photosynthesis to developing kernels, mitigating potential yield penalties caused by defoliation.
What factors contribute most to the retention of general practitioners in rural and remote areas?
Authors: Russell Deborah J. , McGrail Matthew R. , Humphreys John S. , Wakerman John
Published: December 2011

The objectives of this study were to measure the relative strength, significance and contribution of factors associated with rural and remote medical workforce retention. Length of stay data from two Australian GP workforce datasets, the 2008 National Minimum Data Set (4223 GPs) and a subset of the 2008 Medicine in Australia: Balancing Employment and Life dataset (1189 GPs), were separately analysed using multiple linear regression models and the results compared. Length of employment in their current practice location was the outcome measure. Consistent results were obtained across both datasets. The most important factors associated with the retention of rural and remote GPs, after adjusting for GP age, were primary income source, registrar status, hospital work and restrictions on practice location (which are linked to geographic location). Practice ownership was associated with ~70% higher retention than average, whilst undertaking hospital work in addition to routine general practice was associated with at least 18% higher retention compared with if no hospital work was undertaken. Less important factors included geographic location, procedural skills, annual leave, workload and practice size. Our findings quantify a range of financial and economic, professional and organisational, and geographic factors contributing to the retention of rural GPs. These findings have important implications for future medical workforce policy, providing an empirical evidence base to support the targeting and ‘bundling’ of retention initiatives in order to optimise the retention of rural GPs.
Contrasting effects of climate on grey heron, malleefowl and barn owl populations
Authors: Boyle Maria , Hone Jim
Published: December 2011

Context
The population dynamics of many wildlife species are associated with fluctuations in climate. Food and abundance may also influence wildlife dynamics.

Aims
The present paper aims to evaluate the relative effects of climate on the annual instantaneous population growth rate (r) of the following three bird species: grey heron and barn owl in parts of Britain and malleefowl in a part of Australia.

Methods
A priori hypotheses of mechanistic effects of climate are derived and evaluated using information theoretic and regression analyses and published data for the three bird species. Climate was measured as the winter North Atlantic Oscillation (NAO) for herons and owls, and rainfall and also the Southern Oscillation Index (SOI) for malleefowl.

Key results
Population dynamics of grey heron were positively related to the winter NAO, and of malleefowl were positively related to annual rainfall and related in a non-linear manner to SOI. By contrast, population dynamics of barn owl were very weakly related to climate. The best models for the grey heron differed between time periods but always included an effect of the NAO.

Conclusions
The annual population growth rate of grey heron, malleefowl and barn owl show contrasting relationships with climate, from stronger (heron and malleefowl) to weaker (barn owl). The results were broadly consistent with reported patterns but differed in some details. Interpretation of the effects of climate on the basis of analyses rather than visual assessment is encouraged.

Implications
Effects of climate differ among species, so effects of future climate change may also differ.
Explicitations and other types of shifts in the translation of irony and humor
Authors: Hirsch Galia
Published: December 2011

The goal of this article is to examine the differences in the use of explicitation strategies when translating irony and humor, based on a comparative model that distinguishes between cues for the two phenomena. The study suggests that translations of irony manifest more explicitations, whereas translations of humor yield more non-explicitating shifts. This finding can be interpreted as indicating that while the explicitation of humor may override its function altogether, the explicitation of irony does not necessarily do so, since the implied criticism is not eliminated. This finding further strengthens the claim that irony is inherently critical, whereas humor is not.