bluuebunny/crossref_metadata_2025 huggingface dataset:
Les inhibiteurs de la phosphodiestérase de type 5 : une révolution dans le traitement des symptômes du bas appareil urinaire?
Authors: Caremel R. , Laccarier E. , Sibert L.
Published: May 2012

Contexte

L’incidence des symptômes du bas appareil urinaire (SBAU) liés à une hypertrophie bénigne de prostate (HBP) augmente avec l’âge puisqu’ils touchent 50 % des patients âgés de plus de 50 ans et 90 % de ceux âgés de plus de 80 ans. La prévalence et la sévérité de la dysfonction érectile (DE) augmentent également avec l’âge. Sa prévalence est évaluée à 31,6 % dans une population générale d’adultes âgés de plus de 40 ans. Les SBAU comme la DE altèrent de façon significative la qualité de vie (QdV) des patients et de leur partenaire. Plusieurs études ont montré que les SBAU constituent un facteur de risque de DE indépendant de l’âge et des autres comorbidités. La sévérité des SBAU est corrélée à celle de la DE. Les hypothèses physiopathologiques pour expliquer le lien entre SBAU et DE sont : une augmentation du tonus sympathique, une altération du système NO/cGMP, une altération du système rho-kinase et une athéromatose pelvienne.

Objectif

Évaluer les résultats et comprendre le mécanisme d’action de l’administration d’un inhibiteur de la phosphodiestérase de type 5 (IPDE 5) sur les SBAU liés à une HBP.

Matériels et méthodes

Une revue de la littérature a été réalisée à partir des articles originaux et des articles de synthèse déjà disponibles, sélectionnés par le moteur de recherche Pubmed de la National Library of Medecine. Les mots clés utilisés pour cette recherche ont été : benign prostatic hyperplasia; cyclic nucleotide phosphodiesterase type 5; LUTS; erectile dysfunction.

Résultats

Cette revue de la littérature montre que l’administration d’un inhibiteur de la phosphodiestérase de type 5 améliore les SBAU de manière significative dans 12 essais cliniques randomisés, avec un bénéfice également sur la DE et l’absence d’effets secondaires indésirables graves rapportés.

Conclusion

Le traitement des SBAU par les IPDEs 5 semble très prometteur, même s’il ne dispose pas d’une AMM dans cette indication en France. Récemment, le tadalafil à la posologie de 5 mg a été approuvé aux États-Unis par la FDA dans les troubles mictionnels liés à l’HBP, avec ou sans DE.
Origin of non‐cardiac endothelial cells from an Isl1+ lineage
Authors: Keenan Iain D. , Rhee Hong Jun , Chaudhry Bill , Henderson Deborah J.
Published: May 2012

The cardiovascular system consists of many cell types with distinct embryonic origins. Cells from an Islet1 (Isl1)‐expressing progenitor population make a substantial contribution to the developing heart. We reasoned that cells derived from Isl1‐expressing progenitors might contribute more widely to the cardiovascular system. We show that cells derived from an Isl1‐expressing progenitor lineage make a wide contribution to the systemic vasculature and that embryos conditionally deficient for Rac1 within this cell population develop defects in the non‐cardiac vasculature. These data define new roles for Isl1 in the developing embryo and demonstrate a contribution of Isl1‐expressing progenitors to vascular endothelium in vivo.
Abi1, a critical molecule coordinating actin cytoskeleton reorganization with PI‐3 kinase and growth signaling
Authors: Kotula Leszek
Published: May 2012

Coordination of actin cytoskeletal reorganization with growth and proliferation signals is a key cellular process that is not fully understood. PI‐3 kinase is one of the central nodes for distributing growth and proliferation signals downstream from growth factor receptors to the nucleus. Although PI‐3 kinase function has been associated with actin cytoskeleton remodeling, satisfactory explanations of the mechanisms mediating this regulation have been elusive. Here we propose that interaction of the Abi1 protein with the p85 regulatory subunit of PI‐3 kinase represents the link between growth receptor signaling and actin cytoskeleton remodeling. This function of Abi1, which involves WAVE complex, was initially observed in macropinocytosis, and may explain the coincident dysregulation of PI‐3 kinase and actin cytoskeleton in cancer.
Debates in transnational and science studies: a defence and illustration of the virtues of intellectual tolerance
Authors: PESTRE DOMINIQUE
Published: May 2012

When considering the works produced in history of science and transnational history, one is struck by the wide range of issues covered, the profusion of ideas and analyses, the richness and variety of what is proposed. On the other hand, one is also struck by the presence of rather repetitive methodological professions of faith, of declarations of intent about categories and rules that are quite stable over time. This article considers in turn both issues. First, what we have learned in substantial terms, what these historiographical reassessments about science and transnational relations teach us, what has been displaced and what is currently being opened. In the second part, the paper considers what is at stake in these preliminary statements of principle. The article defends the idea that we are facing two major interpretative corpuses that both do count and are heuristically productive, that in practice both are often mixed by historians – but that it is intellectually and politically decisive to consider finely the epistemologies, ontologies and postures that are offered.
Cost-effectiveness and long-term effectiveness of Internet-based cognitive behaviour therapy for severe health anxiety
Authors: Hedman E. , Andersson E. , Lindefors N. , Andersson G. , Rück C. , Ljótsson B.
Published: May 2012

Background

Severe health anxiety is a common condition associated with functional disability, making it a costly disorder from a societal perspective. Internet-based cognitive behaviour therapy (ICBT) is a promising treatment but no previous study has assessed the cost-effectiveness or long-term outcome of ICBT for severe health anxiety. The aim of this study was to investigate the cost-effectiveness and 1-year treatment effects of ICBT for severe health anxiety.

Method

Cost-effectiveness and 1-year follow-up data were obtained from a randomized controlled trial (RCT) comparing ICBT (n = 40) to an attention control condition (CC,n = 41). The primary outcome measure was the Health Anxiety Inventory (HAI). A societal perspective was taken and incremental cost-effectiveness ratios (ICERs) were calculated using bootstrap sampling.

Results

The main ICER was −£1244, indicating the societal economic gain for each additional case of remission when administering ICBT. Baseline to 1-year follow-up effect sizes on the primary outcome measure were large (d = 1.71–1.95).

Conclusions

ICBT is a cost-effective treatment for severe health anxiety that can produce substantial and enduring effects.
LACK-OF-FIT TESTING OF THE CONDITIONAL MEAN FUNCTION IN A CLASS OF MARKOV MULTIPLICATIVE ERROR MODELS
Authors: Koul Hira L. , Perera Indeewara , Silvapulle Mervyn J.
Published: May 2012

The family of multiplicative error models, introduced by Engle (2002, Journal of Applied Econometrics 17, 425–446), has attracted considerable attention in recent literature for modeling positive random variables, such as the duration between trades at a stock exchange, volume transactions, and squared log returns. Such models are also applicable to other positive variables such as waiting time in a queue, daily/hourly rainfall, and demand for electricity. This paper develops a new method for testing the lack-of-fit of a given parametric multiplicative error model having a Markov structure. The test statistic is of Kolmogorov–Smirnov type based on a particular martingale transformation of a marked empirical process. The test is asymptotically distribution free, is consistent against a large class of fixed alternatives, and has nontrivial asymptotic power against a class of nonparametric local alternatives converging to the null hypothesis at the rate of O (n–1/2). In a simulation study, the test performed better overall than the general purpose Ljung–Box Q-test, a Lagrange multiplier type test, and a generalized moment test. We illustrate the testing procedure by considering two data examples.
NONPARAMETRIC TESTS OF MOMENT CONDITION STABILITY
Authors: Juhl Ted , Xiao Zhijie
Published: May 2012

This paper considers testing for moment condition instability for a wide variety of models that arise in econometric applications. We propose a nonparametric test based on smoothing the moment conditions over time. The resulting test takes the form of a U-statistic and has a limiting normal distribution. The proposed test statistic is not affected by changes in the distribution of the data, so long as certain simple regularity conditions hold. We examine the performance of the test through a small Monte Carlo experiment.
Caregiving for Elders in First Nations Communities: Social System Perspective on Barriers and Challenges
Authors: Habjan Sonja , Prince Holly , Kelley Mary Lou
Published: May 2012

Cette recherche a examiné les perspectives et les expériences des membres de la communauté des Premières Nations concernant le soutien sanitaire et social pour les personnes âgées demeurant dans 13 nations du nord-ouest de l’Ontario. Des enquêtes (n = 216) et des groupes de discussion (n = 70) ont été menées en 2005 et 2006 avec les peuples autochtones aînés et leurs aidants formels et informels. Les résultats ont indiqué une forte préférence (69%) pour aider les gens à vieillir et mourir à domicile ; pourtant les obstacles et les défis existaient aux niveaux de la famille, de la communauté, du système de santé, et de la politique sociale. Il s’agissait notamment d’un manque d’aidants proches, des ressources locales humaines et de la santé, les valeurs changeants à travers de la communauté, et d’un accès limité aux services de santé provinciaux et des soins adaptés à la culture et à la sécurité des personnes âgées, tous ce qui a entravé la politique sociale et l’autonomisation des communautés. Un meilleur soutien qui permet aux personnes âgées de vieillir au sein des communautés des Premières Nations exigera des changements du système à plusieurs niveaux et à plusieurs secteurs.
Improving children's dairy food and calcium intake: can intervention work? A systematic review of the literature
Authors: Hendrie Gilly A , Brindal Emily , Baird Danielle , Gardner Claire
Published: May 2012

Objective

Strategies are needed to address the shortfall in children's dairy food and Ca intakes. The present review identified interventions targeting an increase in children's dairy food or Ca intakes, and determined characteristics associated with successful intervention.

Design

A systematic literature search identified fourteen intervention studies, published in English, between 1990 and 2010. Studies were evaluated for study population, setting and mode of delivery, dietary targets and outcome measures, measures of intervention intensity, intervention description, the use of behaviour change techniques and intervention effectiveness.

Setting

Interventions targeting an increase in dairy food or Ca intake.

Subjects

Children aged 5–12 years.

Results

Ten of the fourteen studies were considered to be effective. Studies focusing on encouraging intake of dairy foods or Ca alone were all effective, compared with 55 % of studies promoting dairy within the context of a healthy diet. Effective interventions tended to be higher in intensity, provide dairy foods and were delivered across a variety of settings to a range of primary targets. The number of behaviour change techniques used did not differentiate effective and ineffective interventions, but the use of taste exposure and prompting practice appeared to be important for effective intervention.

Conclusions

Interventions that target an increase in children's dairy food or Ca intake could potentially increase children's dairy food intake by about one serving daily. Research conducted outside the USA is needed. The review has identified some promising strategies likely to be part of effective interventions for improving dairy and Ca intakes in countries where children's intake is insufficient.
Sociodemographic determinants of early weaning: a Finnish birth cohort study in infants with human leucocyte antigen-conferred susceptibility to type 1 diabetes
Authors: Erkkola Maijaliisa , Salmenhaara Maija , Nwaru Bright I , Uusitalo Liisa , Kronberg-Kippilä Carina , Ahonen Suvi , Veijola Riitta , Knip Mikael , Virtanen Suvi M
Published: May 2012

Objective

To assess the most important sociodemographic determinants of age at introduction of complementary foods in infancy.

Design

A prospective birth cohort with increased risk of type 1 diabetes, recruited between 1996 and 2004. The families completed at home a follow-up form on the age at introduction of new foods and, for each clinic visit, a structured dietary questionnaire with 3 d food records.

Setting

Data from the Type 1 Diabetes Prediction and Prevention (DIPP) Project, Finland.

Subjects

A cohort of 5991 infants (77 % of those invited) belonging to the DIPP Nutrition Study.

Results

Sixty-three per cent of the infants were introduced to complementary foods, including infant formula, before the age of 4 months. The median age at introduction of infant formula was 1·5 months (range 0–18 months) and that of the first other complementary food 3·5 months (range 0·7–8 months). All sociodemographic and lifestyle factors studied were associated with the age at introduction of infant formula and/or first other complementary food. Female sex of the infant, being born in the southern region of Finland, living in a rural municipality, the presence of siblings, the mother or the father being a high-school graduate, high maternal professional education and maternal non-smoking during pregnancy predicted later introduction of complementary foods.

Conclusions

Compliance was relatively poor with the current recommendations for the age of introducing complementary foods. Small-sized young families with less well-educated parents were most prone to introduce complementary foods early.
SuperDARN observations of the driver wave associated with FLRs
Authors: Nedie A. Z. , Rankin R. , Fenrich F. R.
Published: May 2012

Ultra‐low frequency (ULF) field line resonances (FLRs) cause oscillations in F‐region plasma flows and can be detected in SuperDARN measured line‐of‐sight (l‐o‐s) velocities. In this paper, we characterize a ULF wave event with coordinated use of SuperDARN HF radars, optical instrumentation, ground based and space based magnetometers. On December 26, 2000 from 00:00–04:00 UT, the SuperDARN Pykkvibaer radar observes first and second harmonic FLR signatures at 0.8 mHz, while the Kodiak and Hankasalmi radars simultaneously observe the driver wave on open field lines at exactly the same 0.8 mHz frequency. These observations show that SuperDARN can provide a diagnostic of MHD wave propagation on open field lines and potentially be used to monitor MHD wave transmission across the magnetopause, and through the outer regions of the magnetosphere. MHD waves in the outer magnetosphere, which couple to FLRs, are seldom observed, and as far as we know this is the first report of a ground based observation of the driver wave. The observation of first and second harmonic FLRs in SuperDARN data is a unique and useful observation in the sense that it supports the theoretical body of work on expected behavior of FLRs, and their potential use in estimating magnetospheric properties such as density and magnetic topology. During the time interval of interest, Geotail is in the solar wind just outside the dawn flank region, and observes clear oscillations in the IMF Bz component at 0.8 mHz. High coherence is shown between the Geotail Bz oscillations and the radar Doppler velocities at 0.8 mHz, confirming that the 0.8 mHz FLR harmonic and the driver wave on open field lines is directly driven by the 0.8 mHz oscillation in the solar wind. Discrete ULF oscillations in the solar wind as direct drivers of ULF waves in the magnetosphere is a controversial topic, and the results reported here add to a growing body of evidence in support of direct solar wind drivers of ULF waves.
Analytical representation of the fault slip velocity from spontaneous dynamic earthquake models
Authors: Bizzarri Andrea
Published: May 2012

We have analyzed the most relevant features of three different analytical representations of the time evolution of the cosesimic slip velocity derived from theoretical basis; the so‐called modified Yoffe function (MY), which pertains to a singular crack solution, the solution for a nonspontaneous crack obeying a position‐weakening governing equation (PR) and the solution for a 1‐D fault model subject to a linear slip‐weakening friction law (B). By considering the same input parameters, we quantitatively compare these slip velocity functions (SVF) and we found that the time evolutions of the velocity and the correspondent slip predicted by the MY and B functions are very similar, while the PR predicts a very sharp peak. Correspondingly, the PR SVF is richer in high frequency and the fall off of its spectrum at high frequencies goes roughly as ω–1.5, while those of MY and B more closely follow ω–2. Then we select two spontaneous, 3‐D, dynamic, subshear models, representing a crack‐like or a pulse‐like rupture and we account for both homogeneous and heterogeneous configurations. We then compare the three SVF in order to see how they are able to reproduce the 3‐D solutions; we also show how the input parameters of the SVF can be constrained from the results of the dynamic models. In the homogeneous cases our results indicate that the MY and the PR SVF reproduce adequately well the main features of a dynamic solution in the case of a crack‐like rupture. The PR function overestimates vpeak and the MY SVF predicts a too rapid deceleration. In the case of a pulse‐like rupture both the MY and the B SVF tend to underestimate vpeak , but all of them capture very well the final cumulated fault slip. Moreover, the B function fits better that the MY the overall behavior of the fault slip. The considered SVF are able to reproduce the spectral fall off of a 3‐D solution at intermediate frequencies (for ω < 20 Hz), the MY and the PR for a crack‐like rupture and the MY and the B SVF for a pulse‐like rupture. In particular, for ω < 10 Hz the spectral content of the B function is practically indistinguishable from that of the spontaneous pulse‐like solution. In the heterogeneous configurations the analytical functions cannot reproduce all the spectral details of the numerical solutions, but we see how it is possible to fit the overall behavior of a single pulse in fault the slip velocity time history. The thorough analysis performed in this work can contribute to the discussion about the debated choice of the source time function to be used in the kinematic models, which in turn is extremely important in the contest of hazard assessment and ground motions generation, although stress heterogeneities, geometrical irregularities, attenuation and free surface effects can definitively smear the details of the analytical functions.
The scientific legacy of Hannes Alfvén
Authors: Fälthammar Carl‐Gunne
Published: May 2012

This year marks 70 years since the publication of a paper with far‐reaching consequences for space and plasma physics: the 1942 letter to Nature by Hannes Alfvén, “Existence of electromagnetic‐hydrodynamic waves.” The letter, which was only half a page long, described a new type of low‐frequency oscillation of a magnetized plasma. The paper was long disregarded or openly rejected, as the new waves that it described could not be demonstrated experimentally at that time. But as experimental techniques improved in the laboratory and experiments in space became possible, it became evident that what are now called Alfvén waves are of fundamental importance in plasma physics in general and space plasma physics in particular. In fact, they constitute a cornerstone of a new field of physics: magneto‐hydrodynamics. Alfvén waves are found in just about every space plasma, such as the Sun, the solar corona, and the solar wind, as well as in magnetospheres of the Earth and other magnetized planets.
A Brazilian network of carbon flux stations
Authors: Roberti Débora R. , Acevedo Otávio C. , Moraes Osvaldo L. L.
Published: May 2012

First Brasflux Workshop; Santa Maria, Rio Grande do Sul, Brazil, 14–15 November 2011 Last November, 33 researchers participated in a workshop to establish Brasflux, the Brazilian network of carbon flux stations, with the objective of integrating previous efforts and planning for the future. Among the participants were those leading ongoing flux observation projects and others planning to establish flux stations in the near future. International scientists also participated to share the experiences gained with other networks. The need to properly characterize terrestrial ecosystems for their roles in the global carbon, water, and energy budgets has motivated the implementation of hundreds of micrometeorological research sites throughout the world in recent years. The eddy covariance (EC) technique for turbulent flux determination is the preferred method to provide integral information on ecosystematmosphere exchanges. Integrating the observations regionally and globally has proven to be an effective approach to maximizing the usefulness of this technique for carbon cycle studies at multiple scales.
Monitoring water from space
Authors: Lakshmi Venkat , Cosh Michael , Alsdorf Douglas
Published: May 2012

AGU Chapman Conference on Remote Sensing of the Terrestrial Water Cycle; Kona, Hawaii, 19–22 February 2012 A Chapman Conference was convened to review the current state of satellite missions and their related research, as well as to identify future needs and directions. The water cycle components considered included soil moisture, precipitation, evapotranspiration, snow/ice, groundwater, and surface water. Remotely sensed data were certainly the focus of the meeting, but ancillary data and in situ resources were also discussed.
Upcoming leadership elections
Authors: Grove Tim
Published: May 2012

Time passes swiftly, and I stand amazed at the continued transformation of AGU. Just under 2 years ago the newly created Board of Directors took office. In that short amount of time members of the Board have established themselves as a highly functioning group of leaders committed to moving the organization forward. They have tackled tough issues as they advance AGU's strategic plan, meet member needs, and bring AGU into the 21st century.
AGU leadership nominees
Authors: Anonymous
Published: May 2012

Board of Directors. Continuing Board Members. Past President Michael McPhaden, Ocean Sciences. President: Carol Finn, Near Surface Geophysics
Radić receives Cryosphere Young Investigator Award: Response
Authors: Radić Valentina
Published: May 2012

Valentina Radić received the 2011 Cryosphere Young Investigator Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award is for “a significant contribution to cryospheric science and technology.”
Interdisciplinary technique helps model landslides
Authors: Schultz Colin
Published: May 2012

Much like tracking the flow of colored grains floating in turbulent water, determining the movements of a specific piece of earth on a landslide‐prone surface is a challenging task. Though recent advances in three‐dimensional surface mapping techniques have improved the detail seen in scans of the Earth's surface, they have not inherently led to improvements in the ability to track changes from one scan to the next. Changes in the surface due to a landslide, or a scanner not set up in precisely the same location between field trips, can make the interpretation of subsequent scans difficult. In some cases, researchers need to manually overlay and analyze sequential images to identify surface deformation.
Soil oxygen affects denitrification
Authors: Balcerak Ernie
Published: May 2012

Rates of denitrification, the metabolic process by which bacteria produce nitrogen (N2) gas, are variable and difficult to measure in ecosystems. Burgin and Groffman sought to learn more about the influence of soil oxygen, which is not often measured, on the denitrification process in wetlands. They collected samples and measured soil oxygen concentration in a riparian zone in Millbrook, N. Y. The site included a wet zone close to a stream and a drier zone slightly farther from the stream.
Joint horizontal‐vertical anisotropic scaling, isobaric and isoheight wind statistics from aircraft data
Authors: Pinel J. , Lovejoy S. , Schertzer D. , Tuck A. F.
Published: May 2012

Aircraft measurements of the horizontal wind have consistently found transitions from roughly k−5/3 to k−2.4 spectra at scales Δxc ranging from about 100–500 km. Since drop sondes find k−2.4spectra in the vertical, the simplest explanation is that the aircraft follow gently sloping trajectories (such as isobars) so that at large scales, they estimate vertical rather than horizontal spectra. In order to directly test this hypothesis, we used over 14500 flight segments from GPS and TAMDAR sensor equipped commercial aircraft. We directly estimate the joint horizontal‐vertical (Δx, Δz) wind structure function finding ‐ for both longitudinal and transverse components ‐ that the ratio of horizontal to vertical scaling exponents isHz ≈ 0.57 ± 0.02, close to the theoretical prediction of the 23/9D turbulence model which predicts Hz = 5/9 = 0.555…. This model also predicts that isobars and isoheight statistics will diverge after Δxc; using the observed fractal dimension of the isobars (≈1.79 ± 0.02), we find that the isobaric scaling exponents are almost exactly as predicted theoretically and Δxc ≈ 160, 125 km, (transverse, longitudinal). These results thus give strong direct support to the 23/9D scaling stratification model.
Targeted Lagrangian sampling of submesoscale dispersion at a coastal frontal zone
Authors: Schroeder K. , Chiggiato J. , Haza A. C. , Griffa A. , Özgökmen T. M. , Zanasca P. , Molcard A. , Borghini M. , Poulain P. M. , Gerin R. , Zambianchi E. , Falco P. , Trees C.
Published: May 2012

The potential impact of rapidly‐evolving submesoscale motions on relative dispersion is at the forefront of physical oceanography, posing challenges for both observations and modeling. A persistent coastal front driven by river outflows in the North‐Western Mediterranean Sea is targeted by two observational cruises conducted in the summer of 2010. The frontal zone is sampled using drifters launched with a multi‐scale strategy consisting of modules of triplets, released on either side of the front by small boats. This experiment is original in that the submesoscale range of 100 m to 1000 m is directly targeted, and the results are expected to provide guidance for practical applications, such as prediction of the initial spreading of pollutants and biogeochemical tracers. The influence of submesoscale motions on relative dispersion is quantified using both particle mean square separation as a function of time, and scale‐dependent finite‐size Lyapunov exponents (FSLE,λ(δ)). Our main finding is the identification of a local dispersion regime with values reaching as high as λ ≈ 20 days−1 at drifter pair separation distances of δ < 100 m. This value is more than an order of magnitude greater than that obtained by drifters in the offshore Ligurian current. The Ligurian Sea circulation is modeled using a fully realistic Regional Ocean Modeling System (ROMS) with 1/60° horizontal resolution. It is found that the numerical model significantly underestimates the relative dispersion at submesoscales, indicating the need for particle dispersion parameterizations for unresolved processes.
The two types of ENSO in CMIP5 models
Authors: Kim Seon Tae , Yu Jin‐Yi
Published: May 2012

In this study, we evaluate the intensity of the Central‐Pacific (CP) and Eastern‐Pacific (EP) types of El Niño‐Southern Oscillation (ENSO) simulated in the pre‐industrial, historical, and the Representative Concentration Pathways (RCP) 4.5 experiments of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Compared to the CMIP3 models, the pre‐industrial simulations of the CMIP5 models are found to (1) better simulate the observed spatial patterns of the two types of ENSO and (2) have a significantly smaller inter‐model diversity in ENSO intensities. The decrease in the CMIP5 model discrepancies is particularly obvious in the simulation of the EP ENSO intensity, although it is still more difficult for the models to reproduce the observed EP ENSO intensity than the observed CP ENSO intensity. Ensemble means of the CMIP5 models indicate that the intensity of the CP ENSO increases steadily from the pre‐industrial to the historical and the RCP4.5 simulations, but the intensity of the EP ENSO increases from the pre‐industrial to the historical simulations and then decreases in the RCP4.5 projections. The CP‐to‐EP ENSO intensity ratio, as a result, is almost the same in the pre‐industrial and historical simulations but increases in the RCP4.5 simulation.
ELF/VLF recordings during the 11 March 2011 Japanese Tohoku earthquake
Authors: Cohen M. B. , Marshall R. A.
Published: May 2012

Broadband ELF/VLF radio recordings (0.2–40 kHz) were made at a site in Onagawa, Japan located ∼102 km from the epicenter of the M9.0 11 March 2011 earthquake, the fifth most powerful earthquake in recorded history. The receiver operated for about two minutes after the start of the earthquake, after which the receiver lost power. Examination of the VLF data shows no radio emissions preceding or coincident with the onset of the earthquake. However, once the secondary seismic waves reached the receiver, a number of impulses and diffuse noise bands arose which may result from the entire power grid shaking or from radio emissions from compressing rocks. Examination of the ELF data (0.2–1 kHz) show no precursor effect in the hours preceding the earthquake. Examination of VLF data from narrowband transmitters shows no anomalous activity in the days or weeks preceding the earthquake. Our instrument low‐frequency cut‐off is ∼200 Hz, and thus we cannot comment on emissions in the ULF range (<10 Hz).
Deformation and surface uplift associated with serpentinization at mid‐ocean ridges and subduction zones
Authors: Germanovich Leonid N. , Genc Gence , Lowell Robert P. , Rona Peter A.
Published: May 2012

We employ the classical problem of an inclusion in an elastic half‐space to model effects of sub‐surface serpentinization on crustal deformation, change of stress state, and surface uplift. At the TAG hydrothermal field on the Mid‐Atlantic Ridge, the model suggests that an anomalous salient 3 km in diameter and 100 m high that projects 3.5 km westward from the east valley wall may have resulted from a relatively deep‐seated well‐serpentinized body exhibiting transformational strain. The associated large strains would likely result in sub‐surface fracturing or faulting, but surface uplift may be relatively insensitive to the exact depth and shape of the serpentinized region. Serpentinization of a region beneath the footwall of the TAG detachment fault will tend to promote slip along some overlying normal faults, which may then enhance fluid pathways to the deeper crust to continue the serpentinization process. Our solution for the Miyazaki Plain above the Kyushu‐Palau subduction zone in SW Japan explains the observed uplift of ≈120 m. The small transformational strains associated with serpentinization in this region may promote thrust‐type events in the aseismic slip zone near the upper boundary of the subducting Philippine Sea Plate as well as intraplate earthquakes associated with normal faulting. The rate of serpentinization needed to produce the observed uplift at the Miyazaki Plain is significantly greater than that needed at TAG, though significantly smaller on per unit volume basis. Thermal effects of serpentinization in both regions appear to be small, but uplift data provide an additional constraint on inferring serpentinization from geological and seismological observations.
The multiscale coarse-graining method. IX. A general method for construction of three body coarse-grained force fields
Authors: Das Avisek , Andersen Hans C.
Published: May 2012

The multiscale coarse-graining (MS-CG) method is a method for constructing a coarse-grained (CG) model of a system using data obtained from molecular dynamics simulations of the corresponding atomically detailed model. The formal statistical mechanical derivation of the method shows that the potential energy function extracted from an MS-CG calculation is a variational approximation for the true potential of mean force of the CG sites, one that becomes exact in the limit that a complete basis set is used in the variational calculation if enough data are obtained from the atomistic simulations. Most applications of the MS-CG method have employed a representation for the nonbonded part of the CG potential that is a sum of all possible pair interactions. This approach, despite being quite successful for some CG models, is inadequate for some others. Here we propose a systematic method for including three body terms as well as two body terms in the nonbonded part of the CG potential energy. The current method is more general than a previous version presented in a recent paper of this series [L. Larini, L. Lu, and G. A. Voth, J. Chem. Phys. 132, 164107 (2010)]10.1063/1.3394863, in the sense that it does not make any restrictive choices for the functional form of the three body potential. We use hierarchical multiresolution functions that are similar to wavelets to develop very flexible basis function expansions with both two and three body basis functions. The variational problem is solved by a numerical technique that is capable of automatically selecting an appropriate subset of basis functions from a large initial set. We apply the method to two very different coarse-grained models: a solvent free model of a two component solution made of identical Lennard-Jones particles and a one site model of SPC/E water where a site is placed at the center of mass of each water molecule. These calculations show that the inclusion of three body terms in the nonbonded CG potential can lead to significant improvement in the accuracy of CG potentials and hence of CG simulations.
Spatially fractional-order viscoelasticity, non-locality, and a new kind of anisotropy
Authors: Hanyga A. , Seredyńska M.
Published: May 2012

A class of non-local viscoelastic equations of motion including equations of fractional order with respect to the spatial variables is studied. It is shown that space-fractional equations of motion of an order strictly less than 2 allow for a new kind of anisotropy, associated with azimuthal dependence of non-local interactions between stress and strain at different material points. Constitutive equations of such viscoelastic media are determined. Relaxation effects are additionally accounted for by replacing second-order time derivatives by lower-order fractional derivatives. Explicit fundamental solutions of the Cauchy problem for scalar equations with isotropic and anisotropic non-locality are constructed. For some particular choices of the parameters, numerical solutions are constructed.
Electrical and photoresponse properties of Co3O4 nanowires
Authors: Varghese Binni , Mukherjee Bablu , Karthik K. R. G. , Jinesh K. B. , Mhaisalkar S. G. , Soon Tok Eng , Haur Sow Chorng
Published: May 2012

Electrical and photocurrent characteristics of single Co3O4 nanowire devices were studied systematically. Current-voltage characteristics’ measurements and impedance spectroscopy of single Co3O4 nanowire devices were performed and analysed using possible mechanism. Photoresponses of individual nanowires were obtained by global irradiation of laser beams with photon energies above band gap and at sub-band gap of the nanowires. The magnitude of photocurrent and its response time revealed that defect level excitations significantly contribute to the photoresponse of Co3O4 nanowires. In addition, the electrically Ohmic nature of the nanowire/Pt contact and p-type conductivity of Co3O4 nanowire is extracted from the current-voltage characteristics and spatially resolved photocurrent measurements.
Fluctuation of mean free path and transition temperature induced vortex pinning in (Ba,K)Fe2As2 superconductors
Authors: Ghorbani S. R. , Wang X. L. , Shahbazi M. , Dou S. X. , Lin C.T.
Published: May 2012

The vortex pinning mechanisms of Ba0.72K0.28Fe2As2 single crystal have been studied systematically as a function of temperature and magnetic field. The temperature dependence of the critical current density, Jc(T), was analysed within the collective pinning model at different magnetic fields. It was found that both the δl pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation, and the δTc pinning mechanism, which is associated with spatial fluctuations of the transition temperature, coexist in the Ba0.72K0.28Fe2As2 single crystal in fields smaller than 4 T. Their contributions are strongly temperature and magnetic field dependent. At lower temperature and B ≤ 4 T, the δl pinning is the dominant mechanism, and its contributions decrease with increasing temperature. At temperatures close to the critical temperature, however, there is evidence for δTc pinning. At magnetic fields larger than 4 T, the δl pinning mechanism is the only effect.
An analytical model of a ferrite-cored inductor used as an eddy current probe
Authors: Lu Yi , Bowler John R. , Theodoulidis Theodoros P.
Published: May 2012

An analytical model of an axisymmetric eddy current ferrite-cored probe above a multi-layered conducting half-space has been developed using a procedure in which the domain of the problem is truncated radially. This means that solutions can be expressed in the form of generalized Fourier-Bessel series. The expansion coefficients are found by matching the field across the interfaces between the subregions of the problem. Initially, the magnetic vector potential of a simple circular current filament is expanded in a series form. The solution is then modified to accommodate an infinitely long coaxial ferrite core, and the principle of superposition is invoked to derive a coil field from the filament field in the presence of the core. Next, we consider a semi-infinite core and then one of finite length. Finally, the effects of a multi-layered conductor are included. Numerical predictions of probe impedance have been compared with experimental data showing excellent agreement.
The three-electron harmonium atom: The lowest-energy doublet and quadruplet states
Authors: Cioslowski Jerzy , Strasburger Krzysztof , Matito Eduard
Published: May 2012

Calculations of sub-μhartree accuracy employing explicitly correlated Gaussian lobe functions produce comprehensive data on the energy E(ω), its components, and the one-electron properties of the two lowest-energy states of the three-electron harmonium atom. The energy computations at 19 values of the confinement strength ω ranging from 0.001 to 1000.0, used in conjunction with a recently proposed robust interpolation scheme, yield explicit approximants capable of estimating E(ω) and the potential energy of the harmonic confinement within a few tenths of μhartree for any ω ⩾ 0.001, the respective errors for the kinetic energy and the potential energy of the electron-electron repulsion not exceeding 2 μhartrees. Thanks to the correct ω → 0 asymptotics incorporated into the approximants, comparable accuracy is expected for values of ω smaller than 0.001. Occupation numbers of the dominant natural spinorbitals and two different measures of electron correlation are also computed.
A dual-band adaptor for infrared imaging
Authors: McLean A. G. , Ahn J-W. , Maingi R. , Gray T. K. , Roquemore A. L.
Published: May 2012

A novel imaging adaptor providing the capability to extend a standard single-band infrared (IR) camera into a two-color or dual-band device has been developed for application to high-speed IR thermography on the National Spherical Tokamak Experiment (NSTX). Temperature measurement with two-band infrared imaging has the advantage of being mostly independent of surface emissivity, which may vary significantly in the liquid lithium divertor installed on NSTX as compared to that of an all-carbon first wall. In order to take advantage of the high-speed capability of the existing IR camera at NSTX (1.6–6.2 kHz frame rate), a commercial visible-range optical splitter was extensively modified to operate in the medium wavelength and long wavelength IR. This two-band IR adapter utilizes a dichroic beamsplitter, which reflects 4–6 μm wavelengths and transmits 7–10 μm wavelength radiation, each with >95% efficiency and projects each IR channel image side-by-side on the camera's detector. Cutoff filters are used in each IR channel, and ZnSe imaging optics and mirrors optimized for broadband IR use are incorporated into the design. In-situ and ex-situ temperature calibration and preliminary data of the NSTX divertor during plasma discharges are presented, with contrasting results for dual-band vs. single-band IR operation.
Versatile system for the temperature-controlled preparation of oxide crystal surfaces
Authors: Pieper H. H. , Lammers C. , Tröger L. , Bahr S. , Reichling M.
Published: May 2012

We present a versatile system for the preparation of oxide crystal surfaces in the ultra-high vacuum (UHV) at temperatures up to 1300 K. Thermal treatment is accomplished by direct current heating of a tantalum foil in contact with the oxide sample. The sample temperature is measured by a thermocouple at a position close to the crystal and its reading is calibrated against the surface temperature determined by a second thermocouple temporarily attached to the surface. The design of the sample holder is based on a transferable plate originally developed for a commercial UHV scanning probe microscope. The system is, however, also suitable for the use with electron spectroscopy or electron diffraction based surface analytical techniques. We present results for the high-temperature preparation of CeO2(111) surfaces with atomically flat terraces exhibiting perfect atomic order and cleanliness as revealed by non-contact atomic force microscopy (NC-AFM) imaging. NC-AFM imaging is, furthermore, used to demonstrate the temperature-controlled aggregation of gold atoms on the CeO2(111) surface and their evaporation at high temperatures.
Spin-dependent Seebeck effect in non-local spin valve devices
Authors: Erekhinsky Mikhail , Casanova Fèlix , Schuller Ivan K. , Sharoni Amos
Published: May 2012

We performed measurements of Py/Cu and Py/Ag lateral spin valves as a function of injection current direction and magnitude. Above a “critical” current, there is an unexpected dependence of spin injection on current direction. Positive currents show higher polarization of spin injection than negative. This implies that in addition to current-induced spin injection, there is a thermally induced injection from a spin-dependent Seebeck effect. A temperature gradient in the Py electrode, caused by Joule heating, is responsible for injecting excess spins into the non-magnetic channel. This effect has important consequences for understanding high-current spin-based devices, such as spin transfer torque devices.
Laser-induced enhancement of tunneling in NHD2
Authors: Sala Matthieu , Guérin Stéphane , Gatti Fabien , Marquardt Roberto , Meyer Hans-Dieter
Published: May 2012

We apply and explore techniques aiming at enhancing the tunneling by laser fields, originally developed for a one-dimensional model, to a complete six-dimensional vibrational model of the inversion motion in NHD2. The computational study is performed with the multi-configuration time-dependent Hartree method. Assuming an ideal three-dimensional alignment we obtain a driven tunneling time twenty times smaller than the natural one, in rather good agreement with an oversimplified three-state model. In the case of one-dimensional alignment, a linearly polarized field leads to a poor enhancement of the tunneling probability, after averaging over the rotation about the alignment axis, whereas a circularly polarized field improves the rotationally averaged tunneling probability at the end of the pulse.
Random telegraph signal and 1/f noise in forward-biased single-walled carbon nanotube film-silicon Schottky junctions
Authors: An Yanbin , Rao Hemant , Bosman Gijs , Ural Ant
Published: May 2012

The electronic noise of single-walled carbon nanotube (CNT) film-Silicon Schottky junctions under forward bias is experimentally characterized. The superposition of a stable 1/f noise and a temporally unstable Lorentzian noise is observed, along with a random telegraph signal (RTS) in the time domain. The data analysis shows that the Lorentzian noise results from the RTS current fluctuations. The data agree well with theoretical descriptions of noise in Schottky junctions due to carrier trapping and detrapping at interface states. Understanding the noise properties of CNT film-Si junctions is important for the integration of CNT film electrodes into silicon-based devices.
Buried-heterostructure quantum-cascade laser overgrown by gas-source molecular-beam epitaxy
Authors: Chashnikova M. , Monastyrskyi G. , Aleksandrova A. , Klinkmüller M. , Semtsiv M. P. , Masselink W. T.
Published: May 2012

We describe the realization of buried-heterostructure quantum-cascade lasers (QCLs) using gas-source molecular beam epitaxy both for the growth of the active region as well as for the regrowth of InP:Fe. The regrowth of the semi-insulating InP:Fe layer was carried out at 470 °C, which is more than 100 °C below the standard growth temperature during metal-organic vapor-phase epitaxy, the standard method for laser overgrowth. The electrical resistivity of the InP:Fe insulation layer, measured in test samples grown on (001) InP, is as large as 2×108Ωcm. High-resistivity InP:Fe is overgrown non-selectively over the etched laser ridge, followed by the top contact alloyed through it to the active region. The processed quantum-cascade lasers show no evidence of parallel leakage current and exhibit lower threshold current density than lasers using SiO2 as an insulator. The ability to fabricate buried heterostructure lasers without exceeding 600 °C is important for strain-compensated AlAs-InGaAs quantum cascade lasers with large internal strain because these devices do not typically withstand temperatures used to grow InP:Fe using vapor-phase epitaxy.
Comment on “Revised electron affinity of SF6 from kinetic data” [J. Chem. Phys. 136, 121102 (2012)]
Authors: Karton Amir , Martin Jan M. L.
Published: May 2012

The adiabatic electron affinity (AEA) of SF6 has been calculated near the relativistic CCSDT(Q) basis set limit. Our best theoretical value (1.0340 ± 0.03 eV) is in excellent agreement with the recently revised experimental value of 1.03 ± 0.05 eV reported by Troe et al. [J. Chem. Phys. 136, 121102 (2012)]10.1063/1.3698170. While our best nonrelativistic, clamped-nuclei, valence CCSD(T) basis set limit value of 0.9058 eV is in good accord with the previously reported CCSD(T)/CBS values, to obtain an accurate AEA, several additional contributions need to be taken into account. The most important one is scalar-relativistic effects (0.0839 eV), followed by inner-shell correlation (0.0216 eV) and post-CCSD(T) correlation effects (0.0248 eV), the latter almost entirely due to connected quadruple excitations. The diagonal Born-Oppenheimer correction is an order of magnitude less important at −0.0022 eV.