bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature‐resolved photoluminescence of nonpolar InGaN/GaN multiple quantum well heterostructures grown on LiAlO2
Authors: Lutsenko Evgenii V. , Rzheutski Mikalai V. , Pavlovskii Viacheslav N. , Muravitskaya Elena V. , Yablonskii Gennadii P. , Mauder Christof , Reuters Ben , Kalisch Holger , Heuken Michael , Vescan Andrei
Published: December 2012

Polarized photoluminescence (PL) of a series of m ‐plane InGaN/GaN multiple quantum well heterostructures (xIn = 5‐30%) was measured in a wide temperature range (T = 10‐580 K). A pronounced S‐shape behaviour of PL band position was observed for all samples which is an evidence of a high degree of localization of photogenerated carriers. From temperature dependences of the PL degree of polarization, the energy difference between the two highest valence subbands ΔE in InGaN was estimated to be increasing from ∼70 meV to ∼160 meV with rising indium content from 5% to 30%. The high‐temperature spectral difference between the polarized PL components was substantially lower than ΔE which is caused by imperfect polarization of optical transitions to different valence subbands. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InGaN/GaN multiple‐quantum well heterostructures for solar cells grown by MOVPE: case studies
Authors: Mukhtarova Anna , Valdueza‐Felip Sirona , Durand Christophe , Pan Qing , Grenet Louis , Peyrade David , Bougerol Catherine , Chikhaoui Walf , Monroy Eva , Eymery Joël
Published: December 2012

We investigate the influence of growth temperature, p ‐doping with bis‐cyclopentadienyl magnesium (Cp2Mg) and number N of multi‐quantum wells on the surface morphology, the electrical and optical properties of InGaN‐based solar cells grown by metal‐organic vapour phase epitaxy. Atomic force microscopy measurements show no influence of multiple‐quantum well number on the surface morphology, but a smoothing with the increase of the Cp2Mg flow. Electrochemical capacitance‐voltage profiling exhibits an increase of the Na‐Nd concentration when increasing the Cp2Mg flow from 250 to 700 sccm. X‐ray diffraction analysis and transmission electron microscopy measurements confirm completely strained quantum wells with similar superlattice period for N=5 to 30. Finally, first solar cells have been demonstrated with a maximum external quantum efficiency of 38% at 380 nm wavelength for N=30. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coriander (Coriandrum sativum L.): A Potential Source of High‐Value Components for Functional Foods and Nutraceuticals‐ A Review
Authors: Sahib Najla Gooda , Anwar Farooq , Gilani Anwarul‐Hassan , Hamid Azizah Abdul , Saari Nazamid , Alkharfy Khalid M.
Published: December 2012

Coriander (Coriandrum sativum L.), a herbal plant, belonging to the family Apiceae, is valued for its culinary and medicinal uses. All parts of this herb are in use as flavoring agent and/or as traditional remedies for the treatment of different disorders in the folk medicine systems of different civilizations. The plant is a potential source of lipids (rich in petroselinic acid) and an essential oil (high in linalool) isolated from the seeds and the aerial parts. Due to the presence of a multitude of bioactives, a wide array of pharmacological activities have been ascribed to different parts of this herb, which include anti‐microbial, anti‐oxidant, anti‐diabetic, anxiolytic, anti‐epileptic, anti‐depressant, anti‐mutagenic, anti‐inflammatory, anti‐dyslipidemic, anti‐hypertensive, neuro‐protective and diuretic. Interestingly, coriander also possessed lead‐detoxifying potential. This review focuses on the medicinal uses, detailed phytochemistry, and the biological activities of this valuable herb to explore its potential uses as a functional food for the nutraceutical industry. Copyright © 2012 John Wiley & Sons, Ltd.
Bayesian analysis of recurrent event with dependent termination: an application to a heart transplant study
Authors: Ouyang Bichun , Sinha Debajyoti , Slate Elizabeth H. , Van Bakel Adrian B.
Published: December 2012

For a heart transplant patient, the risk of graft rejection and risk of death are likely to be associated. Two fully specified Bayesian models for recurrent events with dependent termination are applied to investigate the potential relationships between these two types of risk as well as association with risk factors. We particularly focus on the choice of priors, selection of the appropriate prediction model, and prediction methods for these two types of risk for an individual patient. Our prediction tools can be easily implemented and helpful to physicians for setting heart transplant patients' biopsy schedule. Copyright © 2012 John Wiley & Sons, Ltd.
High‐Performance Photoelectrochemical‐Type Self‐Powered UV Photodetector Using Epitaxial TiO2/SnO2 Branched Heterojunction Nanostructure
Authors: Li Xiaodong , Gao Caitian , Duan Huigao , Lu Bingan , Wang Youqing , Chen Lulu , Zhang Zhenxing , Pan Xiaojun , Xie Erqing
Published: December 2012

TiO2/SnO2 branched heterojunction nanostructure with TiO2 branches on electrospun SnO2 nanofiber (B‐SnO2 NF) networks serves as a model architecture for efficient self‐powered UV photodetector based on a photoelectrochemical cell (PECC). The nanostructure simultaneously offers a low degree of charge recombination and a direct pathway for electron transport. Without correcting 64.5% loss of incident photons through light absorption and scattering by the F‐doped tin oxide (FTO) glass, the incident power conversion efficiency reaches 14.7% at 330 nm, more than twice as large as the nanocrystalline TiO2 (TiO2 NC, 6.4%)‐film based PECC. By connecting a PECC to an ammeter, the intensity of UV light is quantified using the output short‐circuit photocurrent density (Jsc) without a power source. Under UV irradiation, the self‐powered UV photodetector exhibits a high responsivity of 0.6 A/W, a high on/off ratio of 4550, a rise time of 0.03 s and a decay time of 0.01 s for Jsc signal. The excellent performance of the B‐SnO2 NF‐based PECC type self‐powered photodetector will enable significant advancements for next‐generation photodetection and photosensing applications.
Reduction Kinetics of Metal Oxides by Hydrogen
Authors: Dang Jie , Chou Kuo‐Chih , Hu Xiao‐Jun , Zhang Guo‐Hua
Published: December 2012

In this paper, a new kinetic model has been developed for reduction of metal oxides with hydrogen under both isothermal and non‐isothermal conditions. This model describes the kinetics of single reductive reaction and double reductive reactions by considering the diffusion and chemical reaction controlling mechanisms. In particular, the model is in the analytic form of expressing the reduction extent as an explicit function of time, temperature, radius of the particle, and hydrogen partial pressure, which is convenient for using and theoretical analysis. The reduction kinetics of nickel oxide, natural ilmenite, and Fe2MoO4 agree well with the theoretical results by the present model.
Structural reliability for structural engineers evaluating and strengthening a tall building
Authors: Hart Gary C. , Conte Joel , Park Kidong , Reyes Daren , Huang Sampson C.
Published: December 2012

This paper addresses the topic of evaluating and strengthening a tall building in the Los Angeles region. Failure is characterized by the reliability index in terms that can be readily understood by structural engineers with only a basic knowledge of probability theory. The presented formulation requires the structural engineer to believe that the assumption of a normal or log‐normal probability density function for capacity and demand is acceptable for the evaluation and strengthening of a tall building in the Los Angeles region. Copyright © 2012 John Wiley & Sons, Ltd.
An Exploratory Study of Managers' Perspective of Work‐Life Balance in Nigeria: A Case Analysis of the Nigerian Banking Sector
Authors: Mordi Chima , Mmieh Frederick , Ojo Stella Ibiyinka
Published: December 2012

This study describes an exploratory research of managers' perspective of the concept of work‐life balance (WLB) policies and practices in Nigeria. This is done through in‐depth case studies of 20 banks in the banking sector. The data set is comprised of responses from 102 middle line managers in the Nigerian banking institutions. A review of the extant literature on WLB initiatives in the banking sector revealed that there is a dearth of knowledge on WLB policies and practices in an African context. In an attempt to fill the gap in the literature, this study examines the range and scope of WLB practices, managers' perception of WLB, and the forces helping or constraining to shape the choices of work life balance practices and policies. The findings reveal that there is diversity in terms of how middle‐line managers understand and experience WLB initiatives in Nigeria. Another finding highlights the practice of favoritism in most banks using WLB initiatives. In addition, the study shows that cultural sensitivity affects how WLB is appreciated and utilized. The study suggests some policy implications in the form of support for WLB policies in this context. © 2013 Crown copyright.
Results from 2011 for the transportMYpatient program for overcoming transport costs among women seeking treatment for obstetric fistula in Tanzania
Authors: Fiander Alison , Ndahani Clement , Mmuya Kaspar , Vanneste Tom
Published: December 2012

Background

The Comprehensive Community Based Rehabilitation in Tanzania (CCBRT) Disability Hospital program transportMY patient was launched in 2009 to address transport costs, which are a major barrier to patients accessing CCBRT health services. The initiative uses mobile phone technology to transfer funds to cover transport costs.

Methods

Data were reviewed for fistula patients using the transportMYpatient scheme in 2011, noting region of referral. Average costs of using the scheme were calculated and the location of “ambassadors” by region was recorded.

Results

Between 2005 and 2009, CCBRT repaired approximately 170 fistulas annually, increasing to 286 in 2010 and 339 in 2011. In 2011, the transportMYpatient initiative transported 166 fistula patients from almost all regions in Tanzania, accounting for 49% of total repairs.

Conclusion

The increase in referrals to CCBRT during 2011 as a result of the transportMYpatient program shows that transport costs are a real barrier to accessing care. Analysis of geographic referral data informs outreach and community sensitization initiatives, concentrating on regions of low referral. The use of mobile phone technology to transfer funds represents an innovative means of overcoming a major barrier to healthcare access for patients in low‐income countries.
Microscopy & Microanalysis 2013 in Indianapolis
Authors: Ruiz Teresa
Published: December 2012

The Microscopy Society of America, the Microanalysis Society, and the International Metallographic Society invite you to Microscopy & Microanalysis 2013 in Indianapolis, Indiana. This meeting showcases the latest innovative applications and instrumental developments in the biological and physical sciences. This year M&M will feature two plenary lectures, more than 34 symposia, and many educational opportunities in the form of courses and tutorials.
The Open-Source Cornell Spectrum Imager
Authors: Hovden Robert , Cueva Paul , Mundy Julia A. , Muller David A.
Published: December 2012

Hyperspectral imaging (also known as spectrum imaging) requires software for extracting the signatures present in every spectrum. However, commercial software available for spectrum analysis remains expensive, complicated, and often not transparent regarding the internal workings and approximations made. For user facilities, educational institutes, and other settings where multiple users on a single tool can be expected, the limited availability of software becomes the bottleneck to data analysis, user training, and throughput. The Cornell Spectrum Imager (CSI) was developed as a universal data analysis tool to be freely distributed, to run on all computers, and to minimize training. This is accomplished by using one simple interface for imaging, cathodoluminescence, Raman, Electron Energy Loss Spectroscopic (EELS), and EDX data analysis. This article demonstrates the CSI plugins for ImageJ by guiding you through the basic workflow for processing EELS maps.
Microscopy & Microanalysis 2012
Authors: Brewer Luke N.
Published: December 2012

Microscopy & Microanalysis (M&M) 2012 celebrated the first 70 years of the Microscopy Society of America and energized attendees about present and future directions in our field. This joint meeting of the Microscopy Society of America, the Microanalysis Society, and the International Metallographic Society was held in Phoenix, Arizona, July 29–August 2, 2012. The conference had a robust technical program with 996 technical papers, 1,586 scientific attendees, and a total attendance of 2,648. Thirty-six different countries were represented among the attendees. The exhibition showcased 120 companies spread over 363 booths occupying 36,300 square feet of floor space.
Assoziation von Neurodermitis und Aufmerksamkeits-Defizit/Hyperaktivitäts-Syndrom
Authors: Schmitt Jochen , Apfelbacher Christian , Heinrich Joachim , Weidinger Stephan , Romanos Marcel
Published: December 2012

Fragestellung: Die Aufmerksamkeits-Defizit/Hyperaktivitäts-Störung (ADHS) und Neurodermitis sind häufige Erkrankungen des Kindes- und Jugendalters von fächerübergreifender Versorgungsrelevanz. Seit Jahren wird ein möglicher Zusammenhang von Erkrankungen des atopischen Formenkreises und ADHS diskutiert. Methodik: Anhand von je zwei Querschnittsstudien und Geburtskohortenstudien analysierten wir den Zusammenhang von Neurodermitis und ADHS unter Berücksichtigung von Umwelt- und Lifestylefaktoren sowie atopischen Komorbiditäten. Zur Quantifizierung der Assoziation von aktueller oder früherer Neurodermitis und ADHS wurden eine Meta-Analyse durchgeführt unter Verwendung für Alter, Geschlecht und atopische Komorbidität adjustierter Odds Ratios (OR). Ergebnisse: Unsere Daten deuten konsistent auf eine von Umweltexpositionen, soziodemographischen Faktoren und Komorbiditäten unabhängige Assoziation von Neurodermitis und ADHS (OR [95 %] 1.43 [1.25–1.64]) hin, wobei insbesondere die frühkindliche Neurodermitis mit einer späteren Manifestation von ADHS-Symptomen assoziiert zu sein scheint. Schlafstörungen aufgrund der Neurodermitis scheinen für die Assoziation relevant zu sein. Diskussion: Neue epidemiologische Studien deuten konsistent auf eine Assoziation von Neurodermitis und ADHS hin. Die Wahrscheinlichkeit, dass ein Kind mit früherer oder aktueller Neurodermitis die Diagnose ADHS oder klinische ADHS-Symptome aufweist, ist um etwa 43 % erhöht. Nun gilt es die Mechanismen zu erforschen, die der Assoziation von Neurodermitis und ADHS zugrunde liegen. In der Perspektive könnten darauf aufbauend gezielt Therapie- und Präventionsstrategien entwickelt werden.
Strukturelle Konnektivität und Diffusionstensor-Bildgebung bei Autismus-Spektrum-Störungen
Authors: Vomstein Kilian , Stieltjes Bram , Poustka Luise
Published: December 2012

Die Diffusions-Tensor-Bildgebung (DTI) erlangt seit mehreren Jahren in der Erforschung neuropsychiatrischer Krankheitsbilder einen immer höheren Stellenwert. Mit Hilfe dieser Technik können Faserverläufe in vivo dargestellt werden, was bisher anatomischen post-mortem Studien vorbehalten war. Auch bei der Untersuchung neurobiologisch-anatomischer Korrelate kinder- und jugendpsychiatrischer Störungsbilder wie den Autismus-Spektrum-Störungen gewinnt DTI zunehmend an Bedeutung. Die Interpretation dieser Bildgebungsdaten ist allerdings für wissenschaftlich interessierte Kliniker häufig nicht einfach. In vorliegender Übersichtsarbeit sollen daher die Grundlagen der DTI-Bildgebung, wichtige Parameter wie die fraktionelle Anisotropie, radiale, mittlere sowie axiale Diffusivität und ihre zwei wichtigsten Anwendungsmöglichkeiten, das Fibertracking und die Whole Brain-Analyse verständlich erläutert werden. Ferner wird die praktische Anwendung der DTI-Bildgebung bei Autismus-Spektrum-Störungen dargestellt. Dabei sollen sowohl Stärken, aber auch Schwächen und Entwicklungsmöglichkeiten der Technik diskutiert werden.
Suicidality Assessment with PRISM-S – Simple, Fast, and Visual
Authors: Harbauer Gregor , Ring Mariann , Schuetz Christopher , Andreae Andreas , Haas Sebastian
Published: December 2012

Background: The PRISM-S task was developed at the Crisis Intervention Center (KIZ) Winterthur, Switzerland, to enable an assessment of the degree of suicidality in less than 5 minutes with a simple, visual instrument. Aims: Comparison of validity and clinical use of the new PRISM-S task with other instruments known as “gold standards”. Method: Quantitative pilot study enlisting 100 inpatients admitted to the KIZ, aged 15–42 years. Patients’ suicidality was assessed by the PRISM-S task during the first clinical interview and compared to data obtained by standardized suicidality instruments. Results: The patients completed the PRISM-S task in 2 to 5 minutes without difficulty. Data show significant positive correlations between the suicidality as assessed by PRISM-S and the gold standards, i.e., DSI-SS (r = 0.59, N = 65, p < .0001). Limitations: There is no strong evidence that PRISM-S is useful for outpatients or in other settings. The experiences gained with outpatients/patients with other disorders are promising but have not been systematically evaluated. The results do not rely on a randomized design. The sample consists of persons coming to the crisis intervention center. Conclusions: PRISM-S offers a brief, easy-to-administer, and valid method to assess patients’ suicidality. The simple instruction facilitates its use in other languages and other cultures as well. The acceptance by patients and health professionals was good, with no one refusing to complete the task.
The Relationship Between Negative Life Events and Suicidal Behavior
Authors: Rowe Catherine A. , Walker Kristin L. , Britton Peter C. , Hirsch Jameson K.
Published: December 2012

Background: Individuals who experience negative life events may be at increased risk for suicidal behavior. Intrapersonal characteristics, such as basic psychological needs, however, may buffer this association. Aims: To assess the potential moderating role of overall basic psychological needs, and the separate components of autonomy, competence, and relatedness, on the association between negative life events and suicidal behavior. Method: Our sample of 439 college students (311 females, 71%) completed the following self-report surveys: Life Events Scale, Basic Psychological Needs Scale, Beck Depression Inventory – II, and the Suicide Behaviors Questionnaire-Revised. Results: In support of our hypotheses, negative life events were associated with greater levels of suicidal ideation and attempts, and satisfaction of basic psychological needs, including autonomy, relatedness, and competence, significantly moderated this relationship, over and above the effects of the covariates of age, sex, and depressive symptoms. Conclusions: Suicidal behavior associated with the experience of negative life events is not inevitable. Therapeutically bolstering competence, autonomy, and relatedness may be an important suicide prevention strategy for individuals experiencing life stressors.
Smiling After Thinking Increases Reliance on Thoughts
Authors: Paredes Borja , Stavraki Maria , Briñol Pablo , Petty Richard E.
Published: December 2012

The present research examines the impact of smiling on attitude change. Participants were first exposed to a story that elicited mostly positive thoughts (about an employee’s good day at work) or negative thoughts (about an employee’s bad day at work). After writing down their thoughts, participants were asked to hold a pen with their teeth (smile) or with their lips (control). Finally, all participants reported the extent to which they liked the story. In line with the self-validation hypothesis, we predicted and found that the effect of the initial thought direction induction on story evaluations was greater for smiling than control participants. These results conceptually replicate those obtained in previous research on embodiment (i.e., more favorable evaluations of stories when smiling; Strack, Martin, & Stepper, 1988 ) when participants had positive thoughts, but showed the opposite pattern of results (less favorable evaluations for smiling) for negative thoughts.
Data‐driven hypotheses
Authors: van Helden Paul
Published: December 2012

Omics technologies and the large data sets they produce do not undermine hypothesis‐driven research. Rather, they help scientists formulate better and more relevant hypotheses to be put to the test.
Electric field induced polarization and strain of Bi-based ceramic composites
Authors: Su Lee Dae , Jong Jeong Soon , Soo Kim Min , Hyuk Koh Jung
Published: December 2012

The ferroelectric properties and strain behaviors of 0-3-type-ceramic composites were investigated. (100-x)Bi0.5(Na0.75K0.25)TiO3-xBiAlO3 (x = 5, 6, and 7: abbreviated as 95BNKT-5BA, 94BNKT-6BA, and 93BNKT-7BA, respectively, and the three compositions are altogether designated as BNKT-BA) were chosen as a matrix materials, and ferroelectric Bi0.5Na0.5TiO3 (f-BNT), Bi0.5(Na0.8K0.2)0.5TiO3 (f-BNKT), and 98.5Bi0.5(Na0.8K0.2)0.5TiO3-1.5BiAlO3 (f-BNKTBA) grains as inclusions. Large f-BNT, f-BNKT, and f-BNKTBA grains strongly affect the ferroelectric properties and strain behaviors of the BNKT-BA matrix in the composite. In 95BNKT-5BA with f-BNT and f-BNKT, negative strain was observed, indicating that the ferroelectric phase is formed and stabilized. 93BNKT-7BA with f-BNT, f-BNKT and f-BNKTBA showed an increase in positive strain, which is associated with low field-induced phase transition. It was found from the strain curve that two contributions, ferroelectric phase stabilization and phase transition activation, were involved in the strain behaviors of the ceramic composites.
A transition of three to two dimensional Si growth on Ge (100) substrate
Authors: Tu W.-H. , Lee C.-H. , Chang H. T. , Lin B.-H. , Hsu C.-H. , Lee S. W. , Liu C. W.
Published: December 2012

For the initial growth of Si on Ge, three-dimensional Si quantum dots grown on the Ge surface were observed. With increasing Si thickness, the Si growth changes from three-dimensional to two-dimensional growth mode and the dots disappear gradually. Finally, the surface is smooth with the roughness of 0.26 nm, similar to the original Ge substrate, when 15 nm Si is deposited. More Ge segregation on the wetting layer leads to more open sites to increase the subsequent Si growth rate on the wetting layer than on the Si dots. The in-plane x-ray diffraction by synchrotron radiation is used to observe the evolution of tensile strain in the Si layer grown on Ge (100) substrate.
Miniband electronic structure of quantum dash array
Authors: Stupovski B. M. , Crnjanski J. V. , Gvozdić D. M.
Published: December 2012

In the paper, we investigate the miniband structure of one-dimensional quantum dash array and its dependence on geometrical parameters by using a newly developed and efficient numerical method. We show that miniband energy significantly depends on the dash height and width, while the miniband width depends on the array period and the dash width. The excited minibands may exhibit the effect of zero miniband gap and the multiple anticrossings, which are followed by the swapping of the character of adjacent minibands top and bottom. The wetting layer allows formation of a miniband cluster in the vicinity of the well top, which essentially represents the barrier continuum embedded into the well of array.
Efficiency evaluation of ground-penetrating radar by the results of measurement of dielectric properties of soils
Authors: Khakiev Zelimkhan , Kislitsa Konstantin , Yavna Victor
Published: December 2012

The work considers the depth evaluation of ground penetrating radar (GPR) surveys using the attenuation factor of electromagnetic radiation in a medium. A method of determining the attenuation factor of low-conductive non-magnetic soils is developed based on the results of direct measurements of permittivity and conductivity of soils in the range of typical frequencies of GPR. The method relies on measuring the shift and width of the resonance line after a soil sample is being placed into a tunable cavity resonator. The advantage of this method is the preservation of soil structure during the measurement.
Zero-field detection of spin dependent recombination with direct observation of electron nuclear hyperfine interactions in the absence of an oscillating electromagnetic field
Authors: Cochrane C. J. , Lenahan P. M.
Published: December 2012

Electrically detected magnetic resonance (EDMR) involves the electron paramagnetic resonance (EPR) study of spin dependent transport mechanisms such as spin dependent tunneling and spin dependent recombination (SDR) in solid state electronics. Conventional EPR measurements generally require strong static magnetic fields, typically 3 kG or greater, and high frequency oscillating electromagnetic fields, typically 9 GHz or higher. In this study, we directly demonstrate that, in the absence of the oscillating electromagnetic field, a very large SDR response (≈1%) can be detected at zero magnetic field with associated hyperfine interactions at extremely low magnetic fields in a silicon carbide (SiC) diode at room temperature. The zero-field SDR (ZFSDR) response that we detect is unexpected in the conventional detection scheme of SDR via EDMR. We believe that our observations provide fundamental physical understanding of other recently reported zero-field phenomena such as singlet triplet mixing in double quantum dots and low-field giant magnetoresistance in organic semiconductors. Our work provides an unambiguous demonstration that the zero-field phenomenon we observe involves SDR. Measurements reported herein indicate that extremely useful low-field SDR and ZFSDR results can be acquired simply and inexpensively in systems of technological importance. This work also suggests the potential use of this new physics in applications including absolute magnetometry with self-calibration, spin based memories, quantum computation, and inexpensive low-field EDMR spectrometers for wafer/probing stations.
Influence of electric field on local phase transformations in relaxor ferroelectrics PbSc0.5Ta0.5O3 and Pb0.78Ba0.22Sc0.5Ta0.5O3
Authors: Maier B. J. , Steilmann T. , Gospodinov M. , Bismayer U. , Mihailova B.
Published: December 2012

In situ temperature-dependent Raman-scattering experiments under an external dc electric field E have been performed on PbSc0.5Ta0.5O3 (PST) and Pb0.78Ba0.22Sc0.5Ta0.5O3 (PST-Ba) in order to give further insights into the atomistic mechanism of polar coupling in perovskite-type (ABO3) relaxor ferroelectrics near the intermediate characteristic temperature T⋆. The polarized Raman spectra collected under an electric field E applied along the cubic [100], [110], or [111] crystallographic direction were analyzed in terms of hard-mode spectroscopy. The T⋆(E) dependence was derived from the behavior of the phonon mode near 230 cm−1 localized in off-centered B-site cations. In the case of stoichiometric PST, the increase of T⋆ with E is much stronger when the field is applied along [111] than when E is along [100] or [110]. This indicates that the actual polar B-cation shifts are along the cubic body diagonals, implying a rhombohedral structure of the polar nanoregions. The T⋆(E)-dependence reveals that the local structural distortions associated with locally coupled polar displacements of B-site cations reach saturation near 0.5 kV/cm. When Pb2+ is partially replaced by Ba2+, the strong increase of T⋆ with E occurs if the electric field is applied along the [110] direction. This indicates that the substitution disorder on the A-site lowers the symmetry of the polar nanoregions to orthorhombic or monoclinic. The T⋆(E) dependence determined from the B-cation localized mode shows saturation near 2.0 kV/cm, indicating that the zero-field structural state of PST-Ba exhibits less coupled polar shifts of B-site cations as compared to that of PST. According to the E-dependence of the Raman scattering near 55 cm−1, for both compounds the overall response of the Pb system to the external electric field in the vicinity of T⋆(E) resembles antiferroelectric behavior, which along with the fact that the coupling between the B-site cations is ferroelectric, suggests that the polar nanoregions in Pb-based relaxors are ferrielectric in nature.
Variable time-stepping in the pathwise numerical solution of the chemical Langevin equation
Authors: Ilie Silvana
Published: December 2012

Stochastic modeling is essential for an accurate description of the biochemical network dynamics at the level of a single cell. Biochemically reacting systems often evolve on multiple time-scales, thus their stochastic mathematical models manifest stiffness. Stochastic models which, in addition, are stiff and computationally very challenging, therefore the need for developing effective and accurate numerical methods for approximating their solution. An important stochastic model of well-stirred biochemical systems is the chemical Langevin Equation. The chemical Langevin equation is a system of stochastic differential equation with multidimensional non-commutative noise. This model is valid in the regime of large molecular populations, far from the thermodynamic limit. In this paper, we propose a variable time-stepping strategy for the numerical solution of a general chemical Langevin equation, which applies for any level of randomness in the system. Our variable stepsize method allows arbitrary values of the time-step. Numerical results on several models arising in applications show significant improvement in accuracy and efficiency of the proposed adaptive scheme over the existing methods, the strategies based on halving/doubling of the stepsize and the fixed step-size ones.
Real-time, high-resolution x-ray diffraction measurements on shocked crystals at a synchrotron facility
Authors: Gupta Y. M. , Turneaure Stefan J. , Perkins K. , Zimmerman K. , Arganbright N. , Shen G. , Chow P.
Published: December 2012

The Advanced Photon Source (APS) at Argonne National Laboratory was used to obtain real-time, high-resolution x-ray diffraction measurements to determine the microscopic response of shock-compressed single crystals. Disk shaped samples were subjected to plane shock wave compression by impacting them with half-inch diameter, flat-faced projectiles. The projectiles were accelerated to velocities ranging between 300 and 1200 m/s using a compact powder gun designed specifically for use at a synchrotron facility. The experiments were designed to keep the sample probed volume under uniaxial strain and constant stress for a duration longer than the 153.4 ns spacing between x-ray bunches. X-rays from a single pulse (<100 ps duration) out of the periodic x-ray pulses emitted by the synchrotron were used for the diffraction measurements. A synchronization and x-ray detection technique was developed to ensure that the measured signal was obtained unambiguously from the desired x-ray pulse incident on the sample while the sample was in a constant uniaxial strain state. The synchronization and x-ray detection techniques described can be used for a variety of x-ray measurements on shock compressed solids and liquids at the APS. Detailed procedures for applying the Bragg-Brentano parafocusing approach to single crystals at the APS are presented. Analytic developments to determine the effects of crystal substructure and non-ideal geometry on the diffraction pattern position and shape are presented. Representative real-time x-ray diffraction data, indicating shock-induced microstructural changes, are presented for a shock-compressed Al(111) sample. The experimental developments presented here provided, in part, the impetus for the Dynamic Compression Sector (DCS) currently under development at the APS. Both the synchronization/x-ray detection methods and the analysis equations for high-resolution single crystal x-ray diffraction can be used at the DCS.
Two-dimensional nanodiamond monolayers deposited by combined ultracentrifugation and electrophoresis techniques
Authors: Schmidlin L. , Pichot V. , Josset S. , Pawlak R. , Glatzel T. , Kawai S. , Meyer E. , Spitzer D.
Published: December 2012

Dense detonation nanodiamonds deposit has been obtained through a coupled process: Electrophoretic deposition was applied to an ultracentrifugated detonation nanodiamonds suspension. The resulting coating exhibits nearly complete 5 nm thick monolayer coverage of the substrate. The described process is a soft and easily tunable approach, particularly suitable for the development of sensors or the growth of high performance nanodiamond films. The proximity of the adsorbed nanoparticles on the substrate was demonstrated by scanning probe techniques, such as atomic force microscopy and scanning tunneling microscopy.
Back-illuminated separate absorption and multiplication AlGaN solar-blind avalanche photodiodes
Authors: Huang Y. , Chen D. J. , Lu H. , Dong K. X. , Zhang R. , Zheng Y. D. , Li L. , Li Z. H.
Published: December 2012

This letter reports the fabrication and performance of back-illuminated separate absorption and multiplication AlGaN solar-blind avalanche photodiodes. Devices with a 60-μm-diameter active area and a double-mesa structure exhibit a low dark current density of 1.06 × 10−8 A/cm2 at the reverse bias of 20 V and a maximum multiplication gain up to 3000 at the reverse bias of 91 V. The temperature dependence of avalanche voltage shows a large positive temperature coefficient of 0.05 V/K, confirming that avalanche multiplication is the dominant gain mechanism in the photodiodes.
Sub-diffraction optical coherent control of ultrafast electrical currents in antenna devices on GaAs
Authors: Thunich Sebastian , Ruppert Claudia , Holleitner Alexander W. , Betz Markus
Published: December 2012

Femtosecond ω/2ω pulse pairs derived from a compact Er:fibre source induce coherently controlled currents in low temperature grown GaAs. They are characterized by analyzing charge accumulation at contacts closeby. We focus on the photoresponse of bowtie optical antennas integrated into such metal-semiconductor-metal structures. Antennas are designed to enhance the ω field and to confine it into the 50 nm antenna gap. The coherently controlled current is markedly enhanced by the plasmonic nanostructure. However, we find an only unpronounced dependence on the antenna length which is probably related to the large refractive index of GaAs and intricate resonance conditions for ultrabroadband excitation light.
Electric field-tunable BaxSr1−xTiO3 films with high figures of merit grown by molecular beam epitaxy
Authors: Mikheev Evgeny , Kajdos Adam P. , Hauser Adam J. , Stemmer Susanne
Published: December 2012

We report on the dielectric properties of BaxSr1−xTiO3 (BST) films grown by molecular beam epitaxy on epitaxial Pt bottom electrodes. Paraelectric films (x ≲ 0.5) exhibit dielectric losses that are similar to those of BST single crystals and ceramics. Films with device quality factors greater than 1000 and electric field tunabilities exceeding 1:5 are demonstrated. The results provide evidence for the importance of stoichiometry control and the use of a non-energetic deposition technique for achieving high figures of merit of tunable devices with BST thin films.
Magnetic power inverter: AC voltage generation from DC magnetic fields
Authors: Ieda Jun'ichi , Maekawa Sadamichi
Published: December 2012

We propose a method that allows power conversion from DC magnetic fields to AC electric voltages using domain wall (DW) motion in ferromagnetic nanowires. The device concept relies on spinmotive force, voltage generation due to magnetization dynamics. Sinusoidal modulation of the nanowire width introduces a periodic potential for a DW, the gradient of which exerts variable pressure on the traveling DW. This results in time variation of the DW precession frequency and the associated voltage. Using a one-dimensional model, we show that the frequency and amplitude of the AC outputs can be tuned by the DC magnetic fields and wire-design.
What constitutes ‘support’ for the role of the Aboriginal and Torres Strait Islander child health workforce?
Authors: Watson Karen , Young Jeanine , Barnes Margaret
Published: December 2012

As well as providing primary health care services, Aboriginal and Torres Strait Islander health workers are known to significantly contribute to the overall acceptability, access and use of health services through their role of cultural brokerage in the communities within which they work. As such they are uniquely positioned to positively influence health improvements for this vulnerable population. This study sought to identify key areas that both Aboriginal and Torres Strait Islander and non-Indigenous health professionals working within Indigenous communities felt were important in providing support for their roles. This group of workers require support within their roles particularly in relation to cultural awareness and capability, resource provision, educational opportunities, collaboration with colleagues and peers, and professional mentorship. What is known about the topic? Aboriginal and Torres Strait Islander health workers are known to significantly contribute to the overall acceptability, access and use of health services in the communities within which they work. As such they are uniquely positioned to positively influence health improvements for this population. What does this paper add? Through consultation with a sample of Indigenous child health workers and child health workers key areas necessary to provide support for the individuals working in these roles have been identified. What are the implications for practitioners? The findings from this study will inform policy and program development in order to more comprehensively support health workers in the community and contribute towards workforce development and satisfaction, recruitment and retention.
Toxicity of
Jatropha curcas
L. as a biofuel crop and options for management.
Authors: Baldini M. , Raranciuc S. , Vischi M.
Published: December 2012

There are high expectations of
Jatropha curcas
L. as a new crop for biofuel production in the tropics and sub-tropical areas, as evidenced by the forecast expansion of its cultivation in various areas, especially in Asia. The definitive confirmation of the crop as realistic and suitable feedstock for biodiesel will come about when it is able to exploit the vast marginal areas present in many countries, demonstrating the economic sustainability of the whole Jatropha biodiesel chain. Increasing seed yield and oil content remain the main goals, but a valorization of the extruded seed cake, as animal feed, currently prevented by the presence of phorbol esters (PE) toxins, could contribute to a significant improvement in the economic sustainability of the crop. At present, the only reliable process is the seed cake detoxification by washing treatments with solvents and by biotransformation, but these treatments are expensive, not environmentally friendly and difficult to apply in developing countries. In the near future, the solution may come from non-toxic
J. curcas
accessions, which can be used in breeding programmes to recombine non-toxic traits into elite toxic varieties. In general, a plant free of PE would be more acceptable, opening additional market opportunities for the farmers. Strategies for breeding improved non-toxic varieties could be accelerated by DNA-based molecular marker technology, utilizing the simple sequence repeat (SSR) markers associated with toxicity. The whole genome of plant was recently sequenced and this important acquisition is expected to accelerate the process of molecular breeding in
J. curcas
.
Complements of intervals and prefrattini subalgebras of solvable Lie algebras
Authors: Towers David
Published: December 2012

In this paper we study a Lie-theoretic analogue of a generalisation of the prefrattini subgroups introduced by W. Gaschütz. The approach follows that of P. Hauck and H. Kurzweil for groups by first considering complements in subalgebra intervals. Conjugacy of these subalgebras is established for a large class of solvable Lie algebras.
The Rilp-like proteins Rilpl1 and Rilpl2 regulate ciliary membrane content
Authors: Schaub Johanna R. , Stearns Tim
Published: December 2012

The primary cilium is a microtubule-based structure found in most cell types in mammals. Disruption of cilium function causes a diverse set of human diseases collectively known as ciliopathies. We report that Rab effector–related proteins Rab-interacting lysosomal protein-like 1 (Rilpl1) and Rilpl2 regulate protein localization in the primary cilium. Rilpl2 was initially identified as up-regulated in ciliating mouse tracheal epithelial cells. Rilpl1 and Rilpl2 both localize to the primary cilium and centrosome, Rilpl1 specifically to the distal end of the mother centriole. Live-cell microscopy reveals that Rilpl2 primary cilium localization is dynamic and that it is associated with tubulovesicular structures at the base of the cilium. Depletion of Rilpl1 and Rilpl2 results in accumulation of signaling proteins in the ciliary membrane and prevents proper epithelial cell organization in three-dimensional culture. These data suggest that Rilp-like proteins function in regulation of ciliary membrane protein concentration by promoting protein removal from the primary cilium.
β-Catenin–dependent lysosomal targeting of internalized tumor necrosis factor-α suppresses caspase-8 activation in apoptosis-resistant colon cancer cells
Authors: Han Jinbo , Sridevi Priya , Ramirez Michael , Ludwig Kirsten J. , Wang Jean Y. J.
Published: December 2012

The Wnt/β-catenin pathway is constitutively activated in more than 90% of human colorectal cancer. Activated β-catenin stimulates cell proliferation and survival, however, its antiapoptotic mechanisms are not fully understood. We show here that activated β-catenin is required to suppress caspase-8 activation, but only in colon cancer cells that are resistant to tumor necrosis factor-α (TNF)-induced apoptosis. We found that lysosomal delivery of internalized TNF occurred at a faster pace in apoptosis-resistant than in apoptosis-sensitive colon cancer cells. Retardation of endosomal trafficking through vacuolar ATPase (V-ATPase) inhibition enhanced caspase-8 activation in apoptosis-resistant but not apoptosis-sensitive cells. Interestingly, knockdown of β-catenin also prolonged TNF association with the early endosome and enhanced caspase-8 activation in apoptosis-resistant but not apoptosis-sensitive colon cancer cells. In a mouse model of inflammation-associated colon tumors, we found nuclear expression of β-catenin, resistance to TNF-induced apoptosis, and reactivation of apoptosis in vivo after cotreatment of TNF with a V-ATPase inhibitor. Together these results suggest that activated β-catenin can facilitate endosomal trafficking of internalized TNF to suppress caspase-8 activation in colon cancer cells.
Sphingopyxis

italica sp. nov., isolated from Roman catacombs
Authors: Alias-Villegas Cynthia , Jurado Valme , Laiz Leonila , Saiz-Jimenez Cesareo
Published: December 2012

A Gram-stain-negative, aerobic, motile, rod-shaped bacterium, strain SC13E-S71T, was isolated from tuff, volcanic rock, where the Roman catacombs of Saint Callixtus in Rome, Italy, was excavated. Analysis of 16S rRNA gene sequences revealed that strain SC13E-S71T belongs to the genus

Sphingopyxis

, and that it shows the greatest sequence similarity with

Sphingopyxis chilensis

DSM 14889T (98.72 %),

Sphingopyxis taejonensis

DSM 15583T (98.65 %),

Sphingopyxis ginsengisoli

LMG 23390T (98.16 %),

Sphingopyxis panaciterrae

KCTC 12580T (98.09 %),

Sphingopyxis alaskensis

DSM 13593T (98.09 %),

Sphingopyxis witflariensis

DSM 14551T (98.09 %),

Sphingopyxis bauzanensis

DSM 22271T (98.02 %),

Sphingopyxis granuli

KCTC 12209T (97.73 %),

Sphingopyxis macrogoltabida

KACC 10927T (97.49 %),

Sphingopyxis ummariensis

DSM 24316T (97.37 %) and

Sphingopyxis panaciterrulae

KCTC 22112T (97.09 %). The predominant fatty acids were C18 : 1ω7c, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), C14 : 0 2-OH and C16 : 0. The predominant menaquinone was MK-10. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and sphingoglycolipid. These chemotaxonomic data are common to members of the genus

Sphingopyxis

. However, a polyphasic approach using physiological tests, DNA base ratios, DNA–DNA hybridization and 16S rRNA gene sequence comparisons showed that the isolate SC13E-S71T belongs to a novel species within the genus

Sphingopyxis

, for which the name

Sphingopyxis

italica sp. nov. is proposed. The type strain is SC13E-S71T ( = DSM 25229T = CECT 8016T).
Mycobacterium fragae sp. nov., a non-chromogenic species isolated from human respiratory specimens
Authors: Ramos Jesus Pais , Campos Carlos Eduardo Dias , Caldas Paulo Cesar de Souza , Ferreira Nicole Victor , Boas da Silva Mariza Villas , Redner Paulo , Campelo Creusa Lima , Vale Sheila Ferreira , Barroso Elizabeth Clara , Medeiros Reginalda Ferreira de Melo , Montes Fátima Cristina Onofre Fandinho , Galvão Teca Calcagno , Tortoli Enrico
Published: December 2012

Three isolates of a slow-growing, non-chromogenic mycobacterium were grown from three sputum samples of a patient from the north-eastern Ceará state in Brazil. Identification at species level could not be obtained with PCR restriction analysis of the hsp65 gene. In order to characterize the isolates we carried out phenotypic and genotypic tests. We sequenced the nearly complete 16S rRNA gene and obtained partial sequences of the hsp65 (encoding the hypervariable region of the 65 kDa heat-shock protein) and rpoB (encoding the beta-subunit of RNA polymerase) genes. The three isolates turned out to be identical and most closely related to the species

Mycobacterium celatum

and

Mycobacterium kyorinense

. The results, however, showed significant differences between these species and the isolates studied, which led us to consider them members of a novel species for which we propose the name Mycobacterium fragae. The type strain is HF8705T ( = Fiocruz-INCQS/CMRVS P4051T = DSM 45731T).
Nocardioides
marinquilinus sp. nov., isolated from coastal seawater
Authors: Cho Yirang , Jang Gwang Il , Cho Byung Cheol
Published: December 2012

A Gram-stain-positive, non-motile, strictly aerobic, non-spore-forming and short rod-shaped bacterial strain, CL-GY44T, was isolated from coastal seawater, Korea. Analysis of the 16S rRNA gene sequence of strain CL-GY44T revealed a clear affiliation with the genus

Nocardioides

. Based on phylogenetic analysis, strain CL-GY44T showed the closest phylogenetic relationship with

Nocardioides ginsengagri

BX5-10T and

Nocardioides plantarum

NCIMB 12834T. Strain CL-GY44T was not able to grow in the presence of NaCl but grew with 0–5.5 % sea salts. The optimum temperature and pH for growth were 30 °C and pH 7.0. The major cellular fatty acids of strain CL-GY44T were C17 : 1ω6c, iso-C16 : 0, C16 : 0 and iso-C15 : 0 and the major menaquinone was MK-8(H4). The cell-wall analysis showed that strain CL-GY44T contained ll-diaminopimelic acid. The genomic DNA G+C content was 71.6 mol%. The combined phenotypic, chemotaxonomic and phylogenetic data showed that strain CL-GY44T could be clearly distinguished from members of the genus

Nocardioides

. Thus, strain CL-GY44T should be classified as representing a novel species in the genus

Nocardioides

, for which the name Nocardioides marinquilinus sp. nov. is proposed. The type strain is CL-GY44T ( = KCCM 90109T = JCM 18459T).