bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of turbulent transport in the evolution of the κ distribution functions in the plasma sheet
Authors: Stepanova Marina , Antonova Elizaveta E. 
Published: April 2015

AbstractWe studied the evolution of ion and electron distribution functions, approximated by κ distributions, in the plasma sheet with the distance from the Earth using the data of the Time History of Events and Macroscale Interactions during Substorms spacecraft mission. Five events were used to calculate the main parameters of the κ distribution. For these events at least four spacecraft were aligned along the tail between approximately 7 and 30 RE. It was found that for the majority of events the values of κ increase tailward. The observed radial profiles could be related to the inner magnetosphere sources of particle acceleration and to the net tailward transport of particles. This net transport is the result of a balance between the average regular bulk transport toward the Earth and the turbulent transport by eddies in the tailward direction.
Source‐receptor relationships of column‐average CO2 and implications for the impact of observations on flux inversions
Authors: Liu Junjie , Bowman Kevin W. , Henze Daven K. 
Published: April 2015

AbstractSource‐receptor relationships are the fundamental quantities used in atmosphere CO2 flux inversions. In this study, we systematically investigate the global source‐receptor relationships of column CO2 (XCO2) in 12 continental‐scale receptors in terms of transport and local versus nonlocal flux contributions using the GEOS‐Chem adjoint model. Using simulated Greenhouse gases Observing Satellite (GOSAT) XCO2, we quantify the impact of inclusion (add‐on) or exclusion of observations (data‐denial) within a receptor region on flux inversion. We discuss the connections between the observation impact and the underlying source‐receptor relationships. The strong sensitivity of XCO2 to nonlocal fluxes makes the XCO2 observations have strong impact on nonlocal flux estimation. On an annual mean, the impact of GOSAT XCO2 over Europe on North America flux estimation is 10%–39% of the full observation impact. Because the Southern Hemisphere midlatitude XCO2 are most sensitive to local and tropical fluxes, the mean impact of GOSAT XCO2 over Southern South America on Northern South America (N‐S‐America) flux estimation is 30%–59% of the full observation impact. Because of the strong sensitivity of the XCO2 over N‐S‐America to Central Africa (C‐Africa) fluxes, the mean impact on C‐Africa flux estimation is between 14% and 31% of the full observation impact in spite of the sparse observation coverage. The results also show that XCO2 have similar sensitivity to local and nonlocal fluxes occurring 3 months before, which indicates that XCO2 observations cannot differentiate any fluxes occurring beyond 3 months.
A review on regional convection‐permitting climate modeling: Demonstrations, prospects, and challenges
Authors: Prein Andreas F. , Langhans Wolfgang , Fosser Giorgia , Ferrone Andrew , Ban Nikolina , Goergen Klaus , Keller Michael , Tölle Merja , Gutjahr Oliver , Feser Frauke , Brisson Erwan , Kollet Stefan , Schmidli Juerg , van Lipzig Nicole P. M. , Leung Ruby 
Published: April 2015

AbstractRegional climate modeling using convection‐permitting models (CPMs; horizontal grid spacing <4 km) emerges as a promising framework to provide more reliable climate information on regional to local scales compared to traditionally used large‐scale models (LSMs; horizontal grid spacing >10 km). CPMs no longer rely on convection parameterization schemes, which had been identified as a major source of errors and uncertainties in LSMs. Moreover, CPMs allow for a more accurate representation of surface and orography fields. The drawback of CPMs is the high demand on computational resources. For this reason, first CPM climate simulations only appeared a decade ago. In this study, we aim to provide a common basis for CPM climate simulations by giving a holistic review of the topic. The most important components in CPMs such as physical parameterizations and dynamical formulations are discussed critically. An overview of weaknesses and an outlook on required future developments is provided. Most importantly, this review presents the consolidated outcome of studies that addressed the added value of CPM climate simulations compared to LSMs. Improvements are evident mostly for climate statistics related to deep convection, mountainous regions, or extreme events. The climate change signals of CPM simulations suggest an increase in flash floods, changes in hail storm characteristics, and reductions in the snowpack over mountains. In conclusion, CPMs are a very promising tool for future climate research. However, coordinated modeling programs are crucially needed to advance parameterizations of unresolved physics and to assess the full potential of CPMs.
Characterizing the semidiurnal internal tide off Tasmania using glider data
Authors: Boettger Daniel , Robertson Robin , Rainville Luc 
Published: April 2015

AbstractThe spatial structure of the semidiurnal internal tide in the vicinity of Tasmania is characterized using temperature and salinity data from Seaglider and Slocum glider deployments. Wavelet analysis of isopycnal displacements measured by the gliders was used to isolate the semidiurnal internal tide, with a solid signal observed both to the east and to the south of Tasmania. The signal south of Tasmania was attributed to local forcing, while that to the east of Tasmania was found to have propagated from the south east to the north west—a result which supports previous studies indicating the presence of an internal tidal beam originating over the Macquarie Ridge, south of New Zealand. Displacement amplitudes were observed to be amplified in the vicinity of the continental slope, with the incoming tidal beam shown to be both reflected and scattered on the continental slope and shelf, and energy transferred to higher modes.
Evaluation of the summer precipitation over China simulated by BCC_CSM model with different horizontal resolutions during the recent half century
Authors: Kan Mengyun , Huang Anning , Zhao Yong , Zhou Yang , Yang Ben , Wu Haomin 
Published: April 2015

AbstractThe performance of Beijing Climate Center climate system model with different horizontal resolutions (BCC_CSM1.1 with coarse resolution and BCC_CSM1.1 m with fine resolution) in simulating the summer precipitation over China during the recent half century is evaluated, and the possible underlying physical mechanisms related to the model biases are also further analyzed and discussed. Results show that increasing horizontal resolution does improve the summer precipitation simulation over most part of China especially in western China due to the more realistic description of the topography. However, the summer precipitation amount (PA) over eastern China characterized by monsoonal climates is much more underestimated in the finer resolution model. It is also noted that the improvement (deterioration) of the summer PA over western (eastern) China in BCC_CSM1.1 m model is mainly due to the better (worse) simulation of the moderate and heavy precipitation relative to BCC_CSM1.1 model. In addition, increasing model horizontal resolution can significantly improve the convective precipitation simulation especially over western China but shows very limited improvement in the large‐scale precipitation simulation. The much more underestimated summer PA over eastern China in BCC_CSM1.1 m model relative to BCC_CSM1.1 model is due to the significantly reduced positive biases of the convective PA but few changes in the negative biases of the large‐scale PA. Further mechanism analysis suggests that both the underestimated land‐sea thermal contrast and the overestimated Western Pacific subtropical high result in much less northeastward water vapor transport and summer PA over eastern China in BCC_CSM1.1 m model than in BCC_CSM1.1 model.
A new general 1‐D vadose zone flow solution method
Authors: Ogden Fred L. , Lai Wencong , Steinke Robert C. , Zhu Jianting , Talbot Cary A. , Wilson John L. 
Published: April 2015

AbstractWe have developed an alternative to the one‐dimensional partial differential equation (PDE) attributed to Richards (1931) that describes unsaturated porous media flow in homogeneous soil layers. Our solution is a set of three ordinary differential equations (ODEs) derived from unsaturated flux and mass conservation principles. We used a hodograph transformation, the Method of Lines, and a finite water‐content discretization to produce ODEs that accurately simulate infiltration, falling slugs, and groundwater table dynamic effects on vadose zone fluxes. This formulation, which we refer to as “finite water‐content”, simulates sharp fronts and is guaranteed to conserve mass using a finite‐volume solution. Our ODE solution method is explicitly integrable, does not require iterations and therefore has no convergence limits and is computationally efficient. The method accepts boundary fluxes including arbitrary precipitation, bare soil evaporation, and evapotranspiration. The method can simulate heterogeneous soils using layers. Results are presented in terms of fluxes and water content profiles. Comparing our method against analytical solutions, laboratory data, and the Hydrus‐1D solver, we find that predictive performance of our finite water‐content ODE method is comparable to or in some cases exceeds that of the solution of Richards' equation, with or without a shallow water table. The presented ODE method is transformative in that it offers accuracy comparable to the Richards (1931) PDE numerical solution, without the numerical complexity, in a form that is robust, continuous, and suitable for use in large watershed and land‐atmosphere simulation models, including regional‐scale models of coupled climate and hydrology.
On the robustness of numerical algorithms for linear systems and signal processing in finite precision arithmetic
Authors: Diene Oumar , Bhaya Amit 
Published: April 2015

SummaryThis paper proposes a model of the perturbations resulting from finite precision arithmetic implementation of numerical methods. Iterative methods for linear systems are represented as control systems, and the numerical errors caused by finite precision are represented as a multiplicative uncertainty. This representation makes it possible to use results from robust control theory to provide stability criteria, which, in turn, imply convergence, under finite precision arithmetic, of algorithms considered. Numerical examples are taken from several fields in order to illustrate the theoretical results. Copyright © 2015 John Wiley & Sons, Ltd.
Solvent Uptake of Liquid Rubber Toughened Epoxy/Clay Nanocomposites
Authors: Vijayan P. P. , Harikrishnan M. G. , Puglia D. , Vijayan P. P. , Kenny J. M. , Thomas S. 
Published: April 2015

ABSTRACTCarboxyl‐terminated poly (butadiene‐co‐acrylonitrile) (CTBN) liquid rubber toughened epoxy (epoxy/CTBN blend) and CTBN‐toughened epoxy/clay nanocomposites (epoxy/clay/CTBN nanocomposites) were prepared, and solvent (acetone) uptake was studied as a function of CTBN content. It was found that in both epoxy/CTBN blend and epoxy/clay/CTBN nanocomposites, the diffusion coefficient initially increased with an increase in CTBN content, with a maximum value registered for the systems containing 15 phr of CTBN. With a further increase of CTBN, the diffusion coefficient was found to decrease. The variation of solvent uptake with CTBN content depends on both the amount of dissolved rubber in the epoxy phase and the phase morphology associated with each composition. The high acetone uptake in 15 and 20 phr CTBN‐loaded system was found to be reduced dramatically by the incorporation of 3 phr nanoclay. Owing to the presence of high aspect ratio clay platelets, the diffusion of acetone undergoes a more tortuous path in epoxy/clay/CTBN nanocomposites than in epoxy/CTBN blends. A diffusion mechanism correlated to composition for epoxy/CTBN blend and epoxy/clay/CTBN nanocomposites was proposed.
Preventing falls in residential construction: Effectiveness of engaging partners for a national social marketing campaign
Authors: Macario Everly , Hannon Sandra Wills , Baker Robin , Branche Christine M. , Trahan Christina 
Published: April 2015

BackgroundFalls are the leading cause of fatalities in construction. The Safety Pays, Falls Cost campaign aims to prevent falls in residential construction. A critical component of our social marketing approach was to involve 70 partners in reaching target audiences.MethodsWe assessed partner engagement April 2012–August 2013 through: (1) baseline partnership quality interviews (eight partners); (2) pre‐/post‐partner “market” readiness in‐depth interviews (three partners); (3) a pre‐/post‐ (29/31 partners) online partner engagement survey; and (4) standardized metrics to measure partner activity.ResultsWe found a high level of interest and engagement that increased with the addition of prompting to action through regular communication and new resources from organizers and formation of local partnerships that were able to tailor their activities to their own communities or regions.ConclusionIt is feasible to leverage government‐labor‐management partnerships that enjoy trust among target audiences to widely disseminate campaign materials and messages. Am. J. Ind. Med. 58:809–823, 2015. © 2015 Wiley Periodicals, Inc.
Facile Synthesis and Phase Behaviors of Monofunctionalized Hexa‐peri‐hexabenzocoronenes
Authors: Zhou Yu , Zhang Meng‐Yao , Gu Ke‐Hua , Zhu Yu‐Feng , Fan Xing‐He , Shen Zhihao 
Published: April 2015

AbstractFive different kinds of monofunctionalized hexa‐peri‐hexabenzocoronenes (HBCs) are synthesized by loading dialkyl‐diphenylacetylenes and asymmetric diphenylacetylene derivatives at the same time. This method shortens the synthetic route by half, with four fewer steps compared with the commonly used approach. In addition, this method is more economic and environmentally friendly. The self‐assembling properties of the molecules are greatly influenced by the substituted alkyl side chains. From the short linear hexyl chain (C6) to the longer n‐dodecyl (C12) chain and then to the branched alkyl chain (C10,6), the transition temperature from the crystalline phase to the liquid crystalline (LC) phase and that from the LC phase to the isotropic (Iso) state both decrease. Furthermore, the ester group far away from the aromatic core and its length are also important variables to control the phase behaviors of the molecules. The typical long‐range ordered hexagonal lattice (Colh phase) is found for all the monofunctionalized molecules in their LC states.
Cumulen‐Rotaxane: Stabilisierung und Charakterisierung von [9]Cumulenen
Authors: Franz Michael , Januszewski Johanna A. , Wendinger Dominik , Neiss Christian , Movsisyan Levon D. , Hampel Frank , Anderson Harry L. , Görling Andreas , Tykwinski Rik R. 
Published: April 2015

AbstractDie Stabilisierung langer [n]Cumulene wird üblicherweise erreicht, indem sterisch anspruchsvolle “Schutzgruppen” an den Enden angebracht werden, welche die reaktive Kohlenstoffkette abschirmen. Wir stellen hier eine alternative Strategie vor: Stabilisierung durch Einfädeln der sp‐Kohlenstoffkette in einen Phenanthrolin‐basierten Makrocyclus. Dies führt zu stabilen [9]Cumulen‐Rotaxanen, die es uns erlaubten, die Eigenschaften von [n]Cumulenen in Abhängigkeit von ihrer Länge in bis dato unerreichtem Detail zu untersuchen. Dabei nutzten wir quantitative UV/Vis‐Spektroskopie, Cyclovoltammetrie und dynamische Differenzkalorimetrie. Die experimentellen Befunde können durch DFT‐Rechnungen reproduziert und verstanden werden.
Resolving the Differences Between the 1.9 Å and 1.95 Å Crystal Structures of Photosystem II: A Single Proton Relocation Defines Two Tautomeric Forms of the Water‐Oxidizing Complex
Authors: Petrie Simon , Pace Ron J. , Stranger Rob 
Published: April 2015

AbstractGreat progress has been made in characterizing the water‐oxidizing complex (WOC) in photosystem II (PSII) with the publication of a 1.9 Å resolution X‐ray diffraction (XRD) and recently a 1.95 Å X‐ray free‐electron laser (XFEL) structure. However, these achievements are under threat because of perceived conflicts with other experimental data. For the earlier 1.9 Å structure, lack of agreement with extended X‐ray absorption fine structure (EXAFS) data led to the notion that the WOC suffered from X‐ray photoreduction. In the recent 1.95 Å structure, Mn photoreduction is not an issue, but poor agreement with computational models which adopt the ‘high’ oxidation state paradigm, has again resulted in criticism of the structure on the basis of contamination with lower S states of the WOC. Here we use DFT modeling to show that the distinct WOC geometries in the 1.9 and 1.95 Å structures can be straightforwardly accounted for when the Mn oxidation states are consistent with the ‘low’ oxidation state paradigm. Remarkably, our calculations show that the two structures are tautomers, related by a single proton relocation.
Cumulene Rotaxanes: Stabilization and Study of [9]Cumulenes
Authors: Franz Michael , Januszewski Johanna A. , Wendinger Dominik , Neiss Christian , Movsisyan Levon D. , Hampel Frank , Anderson Harry L. , Görling Andreas , Tykwinski Rik R. 
Published: April 2015

AbstractThe stabilization of long [n]cumulenes has traditionally been achieved by placing sterically bulky “protecting groups” at the termini, which shield the reactive carbon chain from unwanted reactions. Herein, we present an alternative strategy: stabilization through threading the sp‐hybridized carbon chain through a phenanthroline‐based macrocycle. The result is stable [9]cumulene rotaxanes that enable the study of properties as a function of length for [n]cumulenes in unprecedented detail, including by quantitative UV/Vis spectroscopy, cyclic voltammetry, and differential scanning calorimetry. The experimental results are supported by DFT calculations.
Meta-analysis of the effect of preoperative breast MRI on the surgical management of ductal carcinoma in situ
Authors: Fancellu A , Turner R M , Dixon J M , Pinna A , Cottu P , Houssami N 
Published: April 2015

Abstract

Background
MRI has been used increasingly in the diagnosis and management of women with invasive breast cancer. However, its usefulness in the preoperative assessment of ductal carcinoma in situ (DCIS) remains questionable. A meta-analysis was conducted to examine the effects of MRI on surgical treatment of DCIS by analysing studies comparing preoperative MRI with conventional preoperative assessment.

Methods
Using random-effects modelling, the proportion of women with various outcomes in the MRI versus no-MRI groups was estimated, and the odds ratio (OR) and adjusted OR (adjusted for study-level median age) for each model were calculated.

Results
Nine eligible studies were identified that included 1077 women with DCIS who had preoperative MRI and 2175 who did not. MRI significantly increased the odds of having initial mastectomy (OR 1·72, P = 0·012; adjusted OR 1·76, P = 0·010). There were no significant differences in the proportion of women with positive margins following breast-conserving surgery (BCS) in the MRI and no-MRI groups (OR 0·80, P = 0·059; adjusted OR 1·10, P = 0·716), nor in the necessity of reoperation for positive margins after BCS (OR 1·06, P = 0·759; adjusted OR 1·04, P = 0·844). Overall mastectomy rates did not differ significantly according to whether or not MRI was performed (OR 1·23, P = 0·340; adjusted OR 0·97, P = 0·881).

Conclusion
Preoperative MRI in women with DCIS is not associated with improvement in surgical outcomes.
Baseline prevalence of abdominal aortic aneurysm, peripheral arterial disease and hypertension in men aged 65–74 years from a population screening study (VIVA trial)
Authors: Grøndal N , Søgaard R , Lindholt J S 
Published: April 2015

Abstract

Background
Abdominal aortic aneurysm (AAA) screening has been introduced into some health systems and could easily be supplemented with broader vascular screening. The aim of this study was to evaluate the screening set-up and investigate combined screening for AAA, peripheral arterial disease (PAD) and possible hypertension (HT), and detection rates.

Methods
This observational study was based on the intervention arm of a screening trial in 25 083 Danish men aged 65–74 years. A combined screening programme for AAA, PAD and HT was offered at local hospitals. Participants with positive test results were offered secondary prophylaxis and/or referred to their general practitioner. The programme set-up included decentralized screening by three mobile teams at 14 venues. Diagnostic criteria were: aortic diameter at least 30 mm for AAA, ankle : brachial pressure index below 0·9 or above 1·4 for PAD, and BP exceeding 160/100 mmHg for HT.

Results
Overall, 18 749 men (uptake 74·7 per cent) attended the screening. An AAA was diagnosed in 3·3 (95 per cent c.i. 3·0 to 3·6) per cent, PAD in 10·9 (10·5 to 11·4) per cent and HT in 10·5 (10·0 to 10·9) per cent. Lipid-lowering and/or antiplatelet treatment was initiated in 34·8 per cent of the participants.

Conclusion
Preventive actions were started in one-third of the attenders. The long-term effect of this on morbidity and mortality is an important part of future analysis. The trial confirms that the prevalence of AAA in Denmark has decreased only slightly in the past decade, from 4·0 to 3·3 per cent, in contrast to other nations.
What Makes a Strong Organic Electron Donor (or Acceptor)?
Authors: Eberle Benjamin , Hübner Olaf , Ziesak Alexandra , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: April 2015

AbstractOrganic electron donors are of importance for a number of applications. However, the factors that are essential for a directed design of compounds with desired reduction power are not clear. Here, we analyze these factors in detail. The intrinsic reduction power, which neglects the environment, has to be separated from extrinsic (e.g., solvent) effects. This power could be quantified by the gas‐phase ionization energy. The experimentally obtained redox potentials in solution and the calculated ionization energies in a solvent (modeled with the conductor‐like screening model (COSMO)) include both intrinsic and extrinsic factors. An increase in the conjugated π‐system of organic electron donors leads to an increase in the intrinsic reduction power, but also decreases the solvent stabilization. Hence, intrinsic and extrinsic effects compete against each other; generally the extrinsic effects dominate. We suggest a simple relationship between the redox potential in solution and the gas‐phase ionization energy and the volume of an organic electron donor. We finally arrive at formulas that allow for an estimate of the (gas‐phase) ionization energy of an electron donor or the (gas‐phase) electron affinity of an electron acceptor from the measured redox potentials in solution. The formulas could be used for neutral organic molecules with no or only small static dipole moment and relatively uniform charge distribution after oxidation/reduction.