bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy‐based excitation control of doubly‐fed induction wind generator for optimum wind energy capture
Authors: Song H.H. , Qu Y.B.
Published: June 2012

A novel nonlinear energy‐based excitation controlling strategy for variable‐speed doubly‐fed induction wind generator (DFIWG) is proposed in this paper. From the consideration of physical nature and energy flow of the DFIWG, the mechanical subsystem and the electromagnetical subsystem of the DFIWG first have their port‐controlled Hamiltonian (PCH) realization. Then taking advantage of the feedback interconnection between the subsystems, the entire PCH model of the DFIWG is established. On the basis of this model, the excitation control for the generator speed adjustment is achieved by energy shaping design with the purpose of optimum wind energy capture. Finally, simulation results via MATLAB/Simulink (MathWorks, Natick, MA, USA) confirm the effectiveness of the proposed approach for wind speeds in different operating stages. Copyright © 2012 John Wiley & Sons, Ltd.
Review of recent offshore wind power developments in china
Authors: Liu T. Y. , Tavner P. J. , Feng Y. , Qiu Y. N.
Published: June 2012

Rapid wind power development in China has attracted worldwide attention. The huge market potential and fast development of wind turbine manufacturing capacity are making China a world leader in wind power development. In 2010, with the newly installed wind power capacity and the cumulative installed capacity, China was ranked first in the world. In 2009, China also constructed and commissioned its first large offshore wind farm near Shanghai.

Following earlier papers reviewing the state of China's onshore wind industry, this paper presents a broader perspective and up‐to‐date survey of China's offshore wind power development, making comparisons between the developments in the rest of the world and China, to draw out similarities and differences and lessons for the China offshore wind industry.

The paper highlights six important aspects for China's offshore wind development: economics, location, Grid connection, technological development, environmental adaptation and national policies.

The authors make recommendations for mitigating some outstanding issues in these six aspects for the future development of China's offshore wind resource. Copyright © 2012 John Wiley & Sons, Ltd.
Utilization of standardless analysis algorithms using WDXRF and XRD for Egyptian iron ore identification
Authors: Shaltout Abdallah A. , Gomma Mohamed M. , Ali‐Bik Mohamed W.
Published: June 2012

On the basis of fundamental parameter approaches, the validity of standardless wavelength dispersive X‐ray fluorescence (WDXRF) and X‐ray powder diffraction algorithms was confirmed for analyzing Egyptian iron ore samples collected from two different locations, Aswan and Baharyia. The studied Egyptian iron ores represent different depositional environments and consequently exhibit variable mineralogical and chemical compositions. In the case of WDXRF analysis, the ground powders of iron ore samples were mixed and pressed with low contamination binder in a mass ratio of wax: sample = 4: 0.9 g at 120 kN cm−2. A standardless method for quantitative WDXRF was employed, which requires accurate determination of the amount of organic material in the sample. On the basis of differential thermal analysis, a new method is introduced for the determination of loss of ignition. With the application of the proposed method and standardless quantitative analysis, results for 12 elements in iron ores were obtained: Fe, Mn, Mg, Si, Al, Ca, Na, K, S, Ba, Zn, and Cl. The reliability and precision of the adopted procedure were tested against a standard reference material ‘Iron ore concentrate (SRM 690, NIST, USA)’. The quantitative analysis results of the certified reference material were found acceptable. Depending on the WDXRF results, the powder samples were directly introduced to X‐ray powder diffraction goniometry, and the phase compositions were quantitatively determined by using a standardless analysis program based on Rietveld method. The main phases of all iron ore samples are the hematite and goethite, whereas other phases are found with varying ratios, namely quartz, nordstrandite, rhodochrosite, kaolinite, todorokit, bassanit, andydrite, and hydroxyapatite. Copyright © 2012 John Wiley & Sons, Ltd.
The Dimeric [V2O4F6]4– Vanadium Oxide‐Fluoride Anion in Na2(M(H2O)2)(V2O4F6) (M = Co2+, Ni2+, and Cu2+)
Authors: Donakowski Martin D. , Vinokur Anastasiya I. , Poeppelmeier Kenneth R.
Published: June 2012

Three new vanadium oxide‐fluoride phases, Na2(M(H2O)2)(V2O4F6) (M = Co2+, Ni2+, and Cu2+), were prepared by hydrothermal techniques in hydrofluoric acid. The compounds contain the dioxo vanadium fluoride dimeric anion: [V2O4F6]4–. The harder (Na+) and softer (M = Co2+, Ni2+, and Cu2+) cations coordinate to the harder fluoride and softer oxide anions, respectively. In contrast to monoxo vanadium fluorides, the dioxo vanadium fluoride exhibits an increased nucleophilicity of the oxide anions. This increased nucleophilicity allows the anion to bond covalently with late transition metals to form 2D layers that contain both an early transition metal (V5+) and a late transition metal (Co2+, Ni2+, or Cu2+).
Describing Teacher–Student Interactions: A Qualitative Assessment of Teacher Implementation of the 7th Grade keepin’ it REAL Substance Use Intervention
Authors: Pettigrew Jonathan , Miller-Day Michelle , Shin YoungJu , Hecht Michael L. , Krieger Janice L. , Graham John W.
Published: June 2012

Variations in the delivery of school‐based substance use prevention curricula affect students’ acquisition of the lesson content and program outcomes. Although adaptation is sometimes viewed as a lack of fidelity, it is unclear what types of variations actually occur in the classroom. This observational study investigated teacher and student behaviors during implementation of a middle school‐based drug prevention curriculum in 25 schools across two Midwestern states. Trained observers coded videos of 276 lessons, reflecting a total of 31 predominantly Caucasian teachers (10 males and 21 females) in 73 different classes. Employing qualitative coding procedures, the study provides a working typology of implementation patterns based on varying levels of teacher control and student participation. These patterns are fairly consistent across lessons and across classes of students, suggesting a teacher‐driven delivery model where teachers create a set of constraints within which students vary their engagement. Findings provide a descriptive basis grounded in observation of classroom implementation that can be used to test models of implementation fidelity and quality as well as impact training and other dissemination research.
Paleontology and Evolution in the News
Authors: Horenstein Sidney
Published: June 2012

This is a review of recent media publications and journal articles about evolution and paleontology.
Social Factors in the Church and Positive Religious Coping Responses: Assessing Differences among Older Whites, Older Blacks, and Older Mexican Americans
Authors: Krause Neal , Hayward R. David
Published: June 2012

Findings from a growing number of studies point to the social basis of a wide range of religious beliefs and behaviors. This study has two main goals. The first is to see whether four social aspects of congregational life (church attendance, attendance at Bible study groups, attendance at prayer groups, and informal spiritual support) are associated with greater use of positive religious coping responses. The second goal is to determine if the relationships between these social aspects of the church and religious coping vary across older whites, older blacks, and older Mexican Americans. The data suggest that more frequent church attendance is associated with greater use of religious coping responses in all three groups. However, the findings further reveal that the relationship between informal spiritual support and religious coping is especially stronger among older whites. The theoretical implications of these findings are discussed.
Eigenvalue problem for fully nonlinear second-order elliptic PDE on balls
Authors: Ikoma Norihisa , Ishii Hitoshi
Published: June 2012

We study the eigenvalue problem for positively homogeneous, of degree one, elliptic ODE on finite intervals and PDE on balls. We establish the existence and completeness results for principal and higher eigenpairs, i.e., pairs of an eigenvalue and its corresponding eigenfunction.
Global existence and collisions for symmetric configurations of nearly parallel vortex filaments
Authors: Banica Valeria , Miot Evelyne
Published: June 2012

We consider the Schrödinger system with Newton-type interactions that was derived by R. Klein, A. Majda and K. Damodaran (1995) [17] to modelize the dynamics of

N

nearly parallel vortex filaments in a 3-dimensional homogeneous incompressible fluid. The known large time existence results are due to C. Kenig, G. Ponce and L. Vega (2003) [16] and concern the interaction of two filaments and particular configurations of three filaments. In this article we prove large time existence results for particular configurations of four nearly parallel filaments and for a class of configurations of

N

nearly parallel filaments for any

N⩾2

. We also show the existence of travelling wave type dynamics. Finally we describe configurations leading to collision.
Roles of 17‐AAG‐induced molecular chaperones and Rma1 E3 ubiquitin ligase in folding and degradation of Pendrin
Authors: Lee Kanghyun , Hong Tae-Joon , Hahn Ji-Sook
Published: June 2012

Pendrin is a transmembrane chloride/anion exchanger highly expressed in thyroid, kidney, and inner ear. Endoplasmic reticulum (ER)‐retention of improperly folded Pendrin mutants is considered as the major cause for Pendred syndrome. However, the folding and degradation mechanisms of Pendrin are poorly understood. Here, we report that treatment of 17‐AAG, an Hsp90 inhibitor, facilitates the folding of Pendrin through heat shock transcription factor 1 (Hsf1)‐dependent induction of molecular chaperones. Furthermore, we demonstrate that Rma1, an E3 ubiquitin ligase localized in the ER membrane, is involved in Pendrin degradation.
PinX1 is involved in telomerase recruitment and regulates telomerase function by mediating its localization
Authors: Cheung Derek Hang-Cheong , Kung Hsiang-Fu , Huang Jun-Jian , Shaw Pang-Chui
Published: June 2012

Telomerase recruitment to telomere is the prerequisite for telomere extension, but the proteins involved in this process are still largely unknown. PinX1 is a telomerase inhibitor and has been implicated in telomere maintenance. Silencing of PinX1 significantly reduced the localization of telomerase to telomere during mid‐late S phase, suggesting the involvement of PinX1 in the cell cycle‐dependent trafficking of hTERT to telomere. We also revealed that PinX1 mediated the chromosomal localization of hTERT during anaphase. This study revealed the role of PinX1 in telomerase function regulation by mediating its localization inside cells.
Coalitions and Language Politics: Policy Shifts in Southeast Asia
Authors: Liu Amy H. , Ricks Jacob I.
Published: June 2012

Why is it that some governments recognize only one language while others espouse multilingualism? Related, why are some governments able to shift language policies, and if there is a shift, what explains the direction? In this article, the authors argue that these choices are theproduct of coalitional constraints facing the government during critical junctures in history. During times of political change in the state-building process, the effective threat of an alternate linguistic group determines the emergent language policy. If the threat is low, the government moves toward monolingual policies. As the threat increases, however, the government is forced to co-opt the alternate linguistic group by shifting the policy toward a greater degree of multilingualism. The authors test this argument by examining the language policies for government services and the education system in three Southeast Asian countries (Singapore, Malaysia, and Thailand).
Examination of the Cooray‐Rubinstein (C‐R) formula for a mixed propagation path by using FDTD
Authors: Zhang Qilin , Li Dongshuai , Fan Yanfeng , Zhang Yuanyuan , Gao Jinge
Published: June 2012

In this paper we extend the Cooray‐Rubinstein (C‐R) formula into a mixed propagation path (vertically stratified conductivity) and estimate the lightning horizontal electric fields over the mixed path, and we have examined its accuracy at distances of 100 m to 1000 m from the lightning channel by using finite difference time domain (FDTD). When the ground conductivity near the observation point is less than that near the strike point, it is noted that the C‐R formula predicts a satisfactory accuracy in the initial several microseconds after the beginning of the return stroke. However, when the ground conductivity near the observation point is larger than that near the strike point, the initial negative excursion predicted by the C‐R formula is underestimated, and the error increases with the increase of the difference between the two sections conductivity.
Probabilistic prediction of barrier‐island response to hurricanes
Authors: Plant Nathaniel G. , Stockdon Hilary F.
Published: June 2012

Prediction of barrier‐island response to hurricane attack is important for assessing the vulnerability of communities, infrastructure, habitat, and recreational assets to the impacts of storm surge, waves, and erosion. We have demonstrated that a conceptual model intended to make qualitative predictions of the type of beach response to storms (e.g., beach erosion, dune erosion, dune overwash, inundation) can be reformulated in a Bayesian network to make quantitative predictions of the morphologic response. In an application of this approach at Santa Rosa Island, FL, predicted dune‐crest elevation changes in response to Hurricane Ivan explained about 20% to 30% of the observed variance. An extended Bayesian network based on the original conceptual model, which included dune elevations, storm surge, and swash, but with the addition of beach and dune widths as input variables, showed improved skill compared to the original model, explaining 70% of dune elevation change variance and about 60% of dune and shoreline position change variance. This probabilistic approach accurately represented prediction uncertainty (measured with the log likelihood ratio), and it outperformed the baseline prediction (i.e., the prior distribution based on the observations). Finally, sensitivity studies demonstrated that degrading the resolution of the Bayesian network or removing data from the calibration process reduced the skill of the predictions by 30% to 40%. The reduction in skill did not change conclusions regarding the relative importance of the input variables, and the extended model's skill always outperformed the original model.
First air‐sea flux mooring measurements in the Southern Ocean
Authors: Schulz E. W. , Josey S. A. , Verein R.
Published: June 2012

The Southern Ocean is a key component of the global climate system: insulating the Antarctic polar region from the subtropics, transferring climate signals throughout the world's oceans and forming the southern component of the global overturning circulation. However, the air‐sea fluxes that drive these processes are severely under‐observed due to the harsh and remote location. This paucity of reference observations has resulted in large uncertainties in ship‐based, numerical weather prediction, satellite and derived flux products. Here, we report observations from the Southern Ocean Flux Station (SOFS); the first successful air‐sea flux mooring deployment in this ocean. The mooring was deployed at 47°S, 142°E for March 2010 to March 2011 and returned measurements of near surface meteorological variables and radiative components of the heat exchange. These observations enable the first accurate quantification of the annual cycle of net air‐sea heat exchange and wind stress from a Southern Ocean location. They reveal a high degree of variability in the net heat flux with extreme turbulent heat loss events, reaching −470 Wm−2in the daily mean, associated with cold air flowing from higher southern latitudes. The observed annual mean net air‐sea heat flux is a small net ocean heat loss of −10 Wm−2, with seasonal extrema of 139 Wm−2 in January and −79 Wm−2in July. The novel observations made with the SOFS mooring provide a key point of reference for addressing the high level of uncertainty that currently exists in Southern Ocean air‐sea flux datasets.
Alfvén‐cyclotron instability with singly ionized helium: Linear theory
Authors: Gary S. Peter , Liu Kaijun , Chen Lunjin
Published: June 2012

The Alfvén‐cyclotron anisotropy instability is driven by a sufficiently large proton temperature anisotropyT⊥/T∥ > 1 where ⊥ and ∥ denote directions perpendicular and parallel, respectively, to the background magnetic field Bo. Here kinetic linear theory for a magnetized, homogeneous, collisionless plasma is used to study this instability at propagation parallel to Boin the presence of a relatively tenuous, relatively cool, isotropic, singly ionized helium component. A sufficiently dense helium component splits the Alfvén‐cyclotron instability into two branches: a proton cyclotron branch at frequencies above the helium cyclotron frequency but below the proton cyclotron frequency, and a helium‐ion cyclotron branch at frequencies less than the helium ion cyclotron frequency. If the helium ions are much cooler than the protons and are sufficiently dense, the helium‐ion cyclotron branch can become unstable at wavelengths considerably shorter than the unstable waves of the proton cyclotron branch, favoring excitation of enhanced fluctuations which resonate with geomagnetically trapped electrons of energies between 500 keV and 2 MeV.
An observationally based evaluation of cloud ice water in CMIP3 and CMIP5 GCMs and contemporary reanalyses using contemporary satellite data
Authors: Li J.‐L. F. , Waliser D. E. , Chen W.‐T. , Guan B. , Kubar T. , Stephens G. , Ma H.‐Y. , Deng M. , Donner L. , Seman C. , Horowitz L.
Published: June 2012

We perform an observationally based evaluation of the cloud ice water content (CIWC) and path (CIWP) of present‐day GCMs, notably 20th century CMIP5 simulations, and compare these results to CMIP3 and two recent reanalyses. We use three different CloudSat + CALIPSO ice water products and two methods to remove the contribution from the convective core ice mass and/or precipitating cloud hydrometeors with variable sizes and falling speeds so that a robust observational estimate can be obtained for model evaluations. The results show that for annual mean CIWP, there are factors of 2–10 in the differences between observations and models for a majority of the GCMs and for a number of regions. However, there are a number of CMIP5 models, including CNRM‐CM5, MRI, CCSM4 and CanESM2, as well as the UCLA CGCM, that perform well compared to our past evaluations. Systematic biases in CIWC vertical structure occur below the mid‐troposphere where the models overestimate CIWC, with this bias arising mostly from the extratropics. The tropics are marked by model differences in the level of maximum CIWC (∼250–550 hPa). Based on a number of metrics, the ensemble behavior of CMIP5 has improved considerably relative to CMIP3, although neither the CMIP5 ensemble mean nor any individual model performs particularly well, and there are still a number of models that exhibit very large biases despite the availability of relevant observations. The implications of these results on model representations of the Earth radiation balance are discussed, along with caveats and uncertainties associated with the observational estimates, model and observation representations of the precipitating and cloudy ice components, relevant physical processes and parameterizations.
The dependence of ice microphysics on aerosol concentration in arctic mixed‐phase stratus clouds during ISDAC and M‐PACE
Authors: Jackson Robert C. , McFarquhar Greg M. , Korolev Alexei V. , Earle Michael E. , Liu Peter S. K. , Lawson R. Paul , Brooks Sarah , Wolde Mengistu , Laskin Alexander , Freer Matt
Published: June 2012

Cloud and aerosol data acquired by the National Research Council of Canada (NRC) Convair‐580 aircraft in, above, and below single‐layer arctic stratocumulus cloud during the Indirect and Semi‐Direct Aerosol Campaign (ISDAC) in April 2008 were used to test three aerosol indirect effects hypothesized to act in mixed‐phase clouds: the riming indirect effect, the glaciation indirect effect, and the thermodynamic indirect effect. The data showed a correlation of R = 0.78 between liquid drop number concentration, Nliq inside cloud and ambient aerosol number concentration NPCASP below cloud. This, combined with increasing liquid water content LWC with height above cloud base and the nearly constant vertical profile of Nliq, suggested that liquid drops nucleated from aerosol at cloud base. No evidence of a riming indirect effect was observed, but a strong correlation of R = 0.69 between ice crystal number concentration Ni and NPCASP above cloud was noted. Increases in ice nuclei (IN) concentration with NPCASP above cloud for 2 flight dates combined with the subadiabatic LWC profiles suggest possible mixing of IN from cloud top consistent with the glaciation indirect effect. The lower Nice and lower effective radius rel for the more polluted ISDAC cases compared to data collected in cleaner single‐layer stratocumulus conditions during the Mixed‐Phase Arctic Cloud Experiment is consistent with the operation of the thermodynamic indirect effect. However, more data in a wider variety of meteorological and surface conditions, with greater variations in aerosol forcing, are required to identify the dominant aerosol forcing mechanisms in mixed‐phase arctic clouds.
Dynamic Functional Cerebral Blood Volume Responses to Normobaric Hyperoxia in Acute Ischemic Stroke
Authors: Wu Ona , Lu Jie , Mandeville Joseph B , Murata Yoshihiro , Egi Yasu , Dai Guangping , Marota John J , Diwan Izzuddin , Dijkhuizen Rick M , Kwong Kenneth K , Lo Eng H , Singhal Aneesh B
Published: June 2012

Studies suggest that neuroprotective effects of normobaric oxygen (NBO) therapy in acute stroke are partly mediated by hemodynamic alterations. We investigated cerebral hemodynamic effects of repeated NBO exposures. Serial magnetic resonance imaging (MRI) was performed in Wistar rats subjected to focal ischemic stroke. Normobaric oxygen-induced functional cerebral blood volume (fCBV) responses were analyzed. All rats had diffusion-weighted MRI (DWI) lesions within larger perfusion deficits, with DWI lesion expansion after 3 hours. Functional cerebral blood volume responses to NBO were spatially and temporally heterogeneous. Contralateral healthy tissue responded consistently with vasoconstriction that increased with time. No significant responses were evident in the acute DWI lesion. In hypoperfused regions surrounding the acute DWI lesion, tissue that remained viable until the end of the experiment showed relative preservation of mean fCBV at early time points, with some rats showing increased fCBV (vasodilation); however, these regions later exhibited significantly decreased fCBV (vasoconstriction). Tissue that became DWI abnormal by study-end initially showed marginal fCBV changes that later became moderate fCBV reductions. Our results suggest that a reverse-steal hemodynamic effect may occur in peripheral ischemic zones during NBO treatment of focal stroke. In addition, CBV responses to NBO challenge may have potential as an imaging marker to distinguish ischemic core from salvageable tissues.
Neural crest stem cell property of apical pulp cells derived from human developing tooth
Authors: Abe Shigehiro , Hamada Keiichi , Miura Masahiko , Yamaguchi Satoshi
Published: June 2012

Recent reports have described that NCSCs (neural crest‐derived stem cells) are not only present in the embryonic neural crest but also in the adult tissues. Dental pulp is one of mesenchymal soft tissues origin from cranial neural crest cells, and thought to be a source of adult stem cells. Here, we investigated the existence of NCSC‐like cells in apical pulp of human developing tooth. Human impacted third molars with immature apex freshly extracted were obtained. The cells derived from the apical pulp tissue not framed by dentin or the coronal pulp tissues were cultured by primary explant culture. APDCs (apical pulp‐derived cells) and CPCs (coronal pulp cells) formed spheres under neurosphere culture condition. The number of spheres from APDCs was larger than that from CPCs. The sphere‐forming cells derived from APDCs had self‐renewal capacity, and expressed neural crest‐associated markers (p75, Snail and Slug) and NSC (neural stem cell) markers (Nestin and Musashi1). The expression pattern of mesenchymal stem cell markers, CD105 and CD166, on the surface of sphere‐forming cells derived APDCs was different from that of APDCs. These sphere‐forming cells could differentiate into multiple mesenchymal lineages (osteoblasts, adipocytes, chondrocytes and smooth muscle cells) and neural lineage (neurons) in vitro, and generated ectopic bone tissues on the border of HA (hydroxyapatite) scaffold in vivo. The results of this study suggest that APDCs contain cells with characteristics of NCSCs reported previously in mice. Humans developing tooth with immature apex is an effective source of cells for neural crest lineage tissue regeneration.
A two-stage approach to relaxation in billiard systems of locally confined hard spheres
Authors: Gaspard Pierre , Gilbert Thomas
Published: June 2012

We consider the three-dimensional dynamics of systems of many interacting hard spheres, each individually confined to a dispersive environment, and show that the macroscopic limit of such systems is characterized by a coefficient of heat conduction whose value reduces to a dimensional formula in the limit of vanishingly small rate of interaction. It is argued that this limit arises from an effective loss of memory. Similarities with the diffusion of a tagged particle in binary mixtures are emphasized.
The role of dissipation in time-dependent non-integrable focusing billiards
Authors: Ryabov Alexei B. , Loskutov Alexander
Published: June 2012

In this study, we compare the dynamical properties of chaotic and nearly integrable time-dependent focusing billiards with elastic and dissipative boundaries. We show that in the system without dissipation the average velocity of particles scales with the number of collisions as V¯∝nα. In the fully chaotic case, this scaling corresponds to a diffusion process with α≈1/2, whereas in the nearly integrable case, this dependence has a crossover; slow particles accelerate in a slow subdiffusive manner with α<1/2, while acceleration of fast particles is much stronger and their average velocity grows super-diffusively, i.e., α>1/2. Assuming V¯∝nα for a non-dissipative system, we obtain that in its dissipative counterpart the average velocity approaches to V¯fin∝1/δα, where δ is the damping coefficient. So that V¯fin∝1/δ in the fully chaotic billiards, and the characteristics exponents α changes with δ from α1>1/2 to α2<1/2 in the nearly integrable systems. We conjecture that in the limit of moderate dissipation the chaotic time-depended billiards can accelerate the particles more efficiently. By contrast, in the limit of small dissipations, the nearly integrable billiards can become the most efficient accelerator. Furthermore, due to the presence of attractors in this system, the particles trajectories will be focused in narrow beams with a discrete velocity spectrum.
Ab initio calculations of the lowest electronic states in the CuNO system
Authors: Krishna B. Murali , Marquardt Roberto
Published: June 2012

The lowest singlet and triplet electronic levels of the A′ and A″ symmetry species of the neutral copper-nitrosyl (CuNO) system are calculated by ab initio methods at the multi-reference configuration interaction (MRCI) level of theory with single and double excitations, and at the coupled cluster level of theory with both perturbational (CCSD(T)) and full inclusion of triple excitations (CCSDT). Experimental data are difficult to obtain, hence the importance of carrying out calculations as accurate as possible to address the structure and dynamics of this system. This paper aims at validating a theoretical protocol to develop global potential energy surfaces for transition metal nitrosyl complexes. For the MRCI calculations, the comparison of level energies at linear structures and their values from \documentclass[12pt]{minimal}\begin{document}${\rm \bf C}_{\rm 2v}$\end{document}C2v and \documentclass[12pt]{minimal}\begin{document}${\rm \bf C}_{\rm s}$\end{document}Cs symmetry restricted calculations has allowed to obtain clear settings regarding atomic basis sizes, active orbital spaces and roots obtained at the multi-configurational self-consistent field (MCSCF) level of theory. It is shown that a complete active space involving 18 valence electrons, 11 molecular orbitals and the prior determination of 12 roots in the MCSCF calculation is needed for overall qualitatively correct results from the MRCI calculations. Atomic basis sets of the valence triple-zeta type are sufficient. The present calculations yield a bound singlet A′ ground state for CuNO. The CCSD(T) calculations give a quantitatively more reliable account of electronic correlation close to equilibrium, while the MRCI energies allow to ensure the qualitative assessment needed for global potential energy surfaces. Relativistic coupled cluster calculations using the Douglas-Kroll-Hess Hamiltonian yield a dissociation energy of CuNO into Cu and NO to be (59 ± 5) kJ mol−1 ((4940 ± 400) hc cm−1). Favorable comparison is made with some of previous theoretical results and a few known experimental data.
High temperature fast response pressure probe for use in liquid metal droplet dispensers
Authors: Rollinger B. , Mansour M. , Abhari R. S.
Published: June 2012

A miniature fast response high temperature pressure probe, with demonstrated use in liquid metals up to 255 °C (528 K), has been developed. Innovative packaging technologies have been applied to integrate a conventional piezoresistive silicon pressure sensor into the probe, without the need of an auxiliary water-cooling system. In situ static calibrations are used to verify the linearity of the pressure signal and the stability of the pressure sensitivity (0.5% standard deviation over 70 min at 255 °C). Dynamic calibration, completed in an air shock tube facility, yields the probe's natural frequency. This frequency, when corrected for probe operation in liquid tin, is found to be 100 kHz. The reliability and accuracy of the probe is assessed by mounting it in a tin droplet dispenser for use in an extreme ultraviolet light source. Droplet dispensers typically include an excitation mechanism, which can be based on the generation of acoustic pressure waves to impose a desired droplet frequency. The probe accuracy is verified by the comparison of pressure measurements with laser Doppler vibrometry measurements of the pressure generating structure. A reference pressure measurement, conducted at representative conditions, shows a complex frequency response, with peaks distributed over three orders of magnitude and maximum amplitude of 440 mbar. Time variance of the excitation mechanism due to thermal transients is studied by monitoring the pressure response during operation. Finally, the linearity of the excitation system, with respect to the excitation amplitude, is verified by response measurements. In conclusion, the developed probe is capable of characterizing the excitation mechanism of a liquid metal droplet dispenser. Additionally, real-time monitoring of the performance of the excitation system during long-term operation is possible.
Charge order suppression, emergence of ferromagnetism and absence of exchange bias effect in Bi0.25Ca0.75MnO3 nanoparticles: Electron paramagnetic resonance and magnetization studies
Authors: Singh Geetanjali , Bhat S. V.
Published: June 2012

We report the results of magnetization and electron paramagnetic resonance (EPR) studies on nanoparticles (average diameter ∼ 30 nm) of Bi0.25Ca0.75MnO3 (BCMO) and compare them with the results on bulk BCMO. The nanoparticles were prepared using the nonaqueous sol-gel technique and characterized by XRD and TEM analysis. Magnetization measurements were carried out with a commercial physical property measurement system (PPMS). While the bulk BCMO exhibits a charge ordering transition at ∼230 K and an antiferromagnetic (AFM) transition at ∼130 K, in the nanoparticles, the CO phase is seen to have disappeared and a transition to a ferromagnetic (FM) state is observed at Tc ∼ 120 K. However, interestingly, the exchange bias effect observed in other nanomanganite ferromagnets is absent in BCMO nanoparticles. EPR measurements were carried out in the X-band between 8 and 300 K. Lineshape fitting to a Lorentzian with two terms (accounting for both the clockwise and anticlockwise rotations of the microwave field) was employed to obtain the relevant EPR parameters as functions of temperature. The results confirm the occurrence of ferromagnetism in the nanoparticles of BCMO.
Brillouin scattering from porous silicon-based optical Bragg mirrors
Authors: Parsons L. C. , Andrews G. T.
Published: June 2012

Brillouin light scattering experiments were done on porous silicon-based optical Bragg mirrors with modulation wavelengths of ∼100 nm. By using a combination of pseudo-reflection and backscattering geometries, phonon dispersion curves along the superlattice modulation axis were mapped. Excellent agreement is obtained with the bulk acoustic mode band structure calculated using a one-dimensional elastic continuum model. In addition to zone-folding of the bulk longitudinal mode dispersion curve, the samples are marked by a surface-localized acoustic mode at the superlattice-air interface. The frequency of this mode lies near the upper edge of a phononic band gap centered at ∼16 GHz. These results, along with optical reflectance data showing visible-range photonic band gaps, reveal that these samples are one-dimensional hypersonic phononic-photonic crystals.
Temperature-driven nucleation of ferromagnetic domains in FeRh thin films
Authors: Baldasseroni C. , Bordel C. , Gray A. X. , Kaiser A. M. , Kronast F. , Herrero-Albillos J. , Schneider C. M. , Fadley C. S. , Hellman F.
Published: June 2012

The evolution of ferromagnetic (FM) domains across the temperature-driven antiferromagnetic (AF) to FM phase transition in uncapped and capped epitaxial FeRh thin films was studied by x-ray magnetic circular dichroism and photoemission electron microscopy. The coexistence of the AF and FM phases was evidenced across the broad transition and the different stages of nucleation, growth, and coalescence were directly imaged. The FM phase nucleates into single domain islands and the width of the transition of an individual nucleus is sharper than that of the transition in a macroscopic average.
Genome-wide analysis of glucocorticoid receptor-binding sites in myotubes identifies gene networks modulating insulin signaling
Authors: Kuo Taiyi , Lew Michelle J. , Mayba Oleg , Harris Charles A. , Speed Terence P. , Wang Jen-Chywan
Published: June 2012

Glucocorticoids elicit a variety of biological responses in skeletal muscle, including inhibiting protein synthesis and insulin-stimulated glucose uptake and promoting proteolysis. Thus, excess or chronic glucocorticoid exposure leads to muscle atrophy and insulin resistance. Glucocorticoids propagate their signal mainly through glucocorticoid receptors (GR), which, upon binding to ligands, translocate to the nucleus and bind to genomic glucocorticoid response elements to regulate the transcription of nearby genes. Using a combination of chromatin immunoprecipitation sequencing and microarray analysis, we identified 173 genes in mouse C2C12 myotubes. The mouse genome contains GR-binding regions in or near these genes, and gene expression is regulated by glucocorticoids. Eight of these genes encode proteins known to regulate distinct signaling events in insulin/insulin-like growth factor 1 pathways. We found that overexpression of p85α, one of these eight genes, caused a decrease in C2C12 myotube diameters, mimicking the effect of glucocorticoids. Moreover, reducing p85α expression by RNA interference in C2C12 myotubes significantly compromised the ability of glucocorticoids to inhibit Akt and p70 S6 kinase activity and reduced glucocorticoid induction of insulin receptor substrate 1 phosphorylation at serine 307. This phosphorylation is associated with insulin resistance. Furthermore, decreasing p85α expression abolished glucocorticoid inhibition of protein synthesis and compromised glucocorticoid-induced reduction of cell diameters in C2C12 myotubes. Finally, a glucocorticoid response element was identified in the p85α GR-binding regions. In summary, our studies identified GR-regulated transcriptional networks in myotubes and showed that p85α plays a critical role in glucocorticoid-induced insulin resistance and muscle atrophy in C2C12 myotubes.
General secretion signal for the mycobacterial type VII secretion pathway
Authors: Daleke Maria H. , Ummels Roy , Bawono Punto , Heringa Jaap , Vandenbroucke-Grauls Christina M. J. E. , Luirink Joen , Bitter Wilbert
Published: June 2012

Mycobacterial pathogens use specialized type VII secretion (T7S) systems to transport crucial virulence factors across their unusual cell envelope into infected host cells. These virulence factors lack classical secretion signals and the mechanism of substrate recognition is not well understood. Here we demonstrate that the model T7S substrates PE25/PPE41, which form a heterodimer, are targeted to the T7S pathway ESX-5 by a signal located in the C terminus of PE25. Site-directed mutagenesis of residues within this C terminus resulted in the identification of a highly conserved motif, i.e., YxxxD/E, which is required for secretion. This motif was also essential for the secretion of LipY, another ESX-5 substrate. Pathogenic mycobacteria have several different T7S systems and we identified a PE protein that is secreted by the ESX-1 system, which allowed us to compare substrate recognition of these two T7S systems. Surprisingly, this ESX-1 substrate contained a C-terminal signal functionally equivalent to that of PE25. Exchange of these C-terminal secretion signals between the PE proteins restored secretion, but each PE protein remained secreted via its own ESX secretion system, indicating that an additional signal(s) provides system specificity. Remarkably, the YxxxD/E motif was also present in and required for efficient secretion of the ESX-1 substrates CFP-10 and EspB. Therefore, our data show that the YxxxD/E motif is a general secretion signal that is present in all known mycobacterial T7S substrates or substrate complexes.
Lead poisoning and the deceptive recovery of the critically endangered California condor
Authors: Finkelstein Myra E. , Doak Daniel F. , George Daniel , Burnett Joe , Brandt Joseph , Church Molly , Grantham Jesse , Smith Donald R.
Published: June 2012

Endangered species recovery programs seek to restore populations to self-sustaining levels. Nonetheless, many recovering species require continuing management to compensate for persistent threats in their environment. Judging true recovery in the face of this management is often difficult, impeding thorough analysis of the success of conservation programs. We illustrate these challenges with a multidisciplinary study of one of the world’s rarest birds—the California condor (Gymnogyps californianus). California condors were brought to the brink of extinction, in part, because of lead poisoning, and lead poisoning remains a significant threat today. We evaluated individual lead-related health effects, the efficacy of current efforts to prevent lead-caused deaths, and the consequences of any reduction in currently intensive management actions. Our results show that condors in California remain chronically exposed to harmful levels of lead; 30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects, measured as >60% inhibition of the heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ∼20% of free-flying birds have blood lead levels (≥450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality. Lead isotopic analysis shows that lead-based ammunition is the principle source of lead poisoning in condors. Finally, population models based on condor demographic data show that the condor’s apparent recovery is solely because of intensive ongoing management, with the only hope of achieving true recovery dependent on the elimination or substantial reduction of lead poisoning rates.
Attentional dynamics of infant visual foraging
Authors: Robertson Steven S. , Watamura Sarah Enos , Wilbourn Makeba Parramore
Published: June 2012

Young infants actively gather information about their world through visual foraging, but the dynamics of this important behavior is poorly understood, partly because developmental scientists have often equated its essential components, looking and attending. Here we describe a method for simultaneously tracking spatial attention to fixated and nonfixated locations during free looking in 12-week-old infants using steady-state visual evoked potentials (SSVEPs). Using this method, we found that the sequence of locations an infant inspects during free looking reflects a momentary bias away from locations that were recently the target of covert attention, quickly followed by the redirection of attention—in advance of gaze—to the next target of fixation. The result is a pattern of visual foraging that is likely to support efficient exploration of complex environments by facilitating the inspection of new locations in real time.
Chemical and genetic evidence for the involvement of Wnt antagonist Dickkopf2 in regulation of glucose metabolism
Authors: Li Xiaofeng , Shan Jufang , Chang Woochul , Kim Ingyu , Bao Ju , Lee Ho-Jin , Zhang Xinxin , Samuel Varman T. , Shulman Gerald I. , Liu Dakai , Zheng Jie J. , Wu Dianqing
Published: June 2012

Mutations in Wnt receptor LRP5/6 and polymorphism in Wnt-regulated transcription factor TCF7L2 are associated with dysregulation of glucose metabolism. However, it is not clear whether Wnt antagonist Dickkopf (Dkk) has a significant role in the regulation of glucose metabolism. Here, we identified small-molecule inhibitors of Wnt antagonist Dkk through molecular modeling, computation-based virtual screens, and biological assays. One of the Dkk inhibitors reduced basal blood-glucose concentrations and improved glucose tolerance in mice. This Dkk inhibitor appeared to act through DKK2 because the inhibitor exerted no additional effects on glucose metabolism in the
Dkk2
−/−
mice. Our study of
Dkk2
−/−
mice showed that DKK2 deficiency was associated with increased hepatic glycogen accumulation and decreased hepatic glucose output. DKK2 deficiency did not cause in increase in insulin production but resulted in increased Wnt activity and GLP1 production in the intestines. Given that the Dkk inhibitor improved glucose tolerance in a murine model of type 2 diabetes (
db
/
db
), we suggest that DKK2 may be a potential therapeutic target for treating type 2 diabetes.
Cholinergic interneurons in the nucleus accumbens regulate depression-like behavior
Authors: Warner-Schmidt Jennifer L. , Schmidt Eric F. , Marshall John J. , Rubin Amanda J. , Arango-Lievano Margarita , Kaplitt Michael G. , Ibañez-Tallon Ines , Heintz Nathaniel , Greengard Paul
Published: June 2012

A large number of studies have demonstrated that the nucleus accumbens (NAC) is a critical site in the neuronal circuits controlling reward responses, motivation, and mood, but the neuronal cell type(s) underlying these processes are not yet known. Identification of the neuronal cell types that regulate depression-like states will guide us in understanding the biological basis of mood and its regulation by diseases like major depressive disorder. Taking advantage of recent findings demonstrating that the serotonin receptor chaperone, p11, is an important molecular regulator of depression-like states, here we identify cholinergic interneurons (CINs) as a primary site of action for p11 in the NAC. Depression-like behavior is observed in mice after decrease of p11 levels in NAC CINs. This phenotype is recapitulated by silencing neuronal transmission in these cells, demonstrating that accumbal cholinergic neuronal activity regulates depression-like behaviors and suggesting that accumbal CIN activity is crucial for the regulation of mood and motivation.
Teaching the Teachers: Faculty Preparedness and Evaluation of a Retreat in Screening, Brief Intervention, and Referral to Treatment
Authors: Childers Julie W. , Broyles Lauren M. , Hanusa Barbara H. , Kraemer Kevin L. , Conigliaro Joseph , Spagnoletti Carla , McNeil Melissa , Gordon Adam J.
Published: June 2012

Effective clinical faculty are essential for disseminating substance abuse screening, brief intervention, and referral to treatment (SBIRT). The authors developed an 8-hour SBIRT training for internal medicine faculty preceptors. Trainers conducted SBIRT lectures and small-group communication practice sessions. The authors assessed participants’ ( n = 27) knowledge, skills, and attitudes using an enhanced Alcohol and Alcohol Problems Perceptions Questionnaire (AAPPQ). Participants self-assessed their changes in SBIRT competence and comfort. Faculty trainees did not feel competent in SBIRT, particularly in intervention and referral to treatment. AAPPQ subscale scores were highest in Role Legitimacy and Motivation and lowest in Role Adequacy and Satisfaction. After training, faculty members reported greater likelihood of performing and teaching SBIRT. In some topic areas, faculty attending an SBIRT training reported limited knowledge and competence for treating drinkers; however, their interest and motivation for doing so was high. Ongoing faculty and organizational development efforts may help close these gaps.
Web-Based SBIRT Skills Training for Health Professional Students and Primary Care Providers
Authors: Tanner T. Bradley , Wilhelm Susan E. , Rossie Karen M. , Metcalf Mary P.
Published: June 2012

The authors have developed and assessed 2 innovative, case-based, interactive training programs on substance abuse, one for health professional students on alcohol and one for primary care providers on screening, brief intervention, and referral to treatment (SBIRT). Both programs build skills in substance abuse SBIRT. Real-world effectiveness trials involving medical students ( n = 10) and nursing students ( n = 60) were completed; trials involving primary care providers ( n = 65) are in progress during 2011. Medical students and nursing students had similarly low baseline scores on assessments that benefited from training: knowledge, confidence, and clinical performance measured via an online standardized patient case and encounter note all improved post-training. Preliminary results indicate that practicing providers improved on knowledge, attitude, and brief intervention skill performance after a similar training. Results suggest that SBIRT skills can be improved with this model for case-based interactive training programs, and thus, that this training has the potential to impact patient outcomes.