bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow network derivation from a high resolution DEM in a low relief, agrarian landscape
Authors: Schwanghart Wolfgang , Groom Geoff , Kuhn Nikolaus J. , Heckrath Goswin
Published: June 2013

Digital flow networks derived from digital elevation models (DEMs) sensitively react to errors due to measurement, data processing and data representation. Since high‐resolution DEMs are increasingly used in geomorphological and hydrological research, automated and semi‐automated procedures to reduce the impact of such errors on flow networks are required. One such technique is stream‐carving, a hydrological conditioning technique to ensure drainage connectivity in DEMs towards the DEM edges. Here we test and modify a state‐of‐the‐art carving algorithm for flow network derivation in a low‐relief, agricultural landscape characterized by a large number of spurious, topographic depressions. Our results show that the investigated algorithm reconstructs a benchmark network insufficiently in terms of carving energy, distance and a topological network measure. The modification to the algorithm that performed best, combines the least‐cost auxiliary topography (LCAT) carving with a constrained breaching algorithm that explicitly takes automatically identified channel locations into account. We applied our methods to a low relief landscape, but the results can be transferred to flow network derivation of DEMs in moderate to mountainous relief in situations where the valley bottom is broad and flat and precise derivations of the flow networks are needed. Copyright © 2013 John Wiley & Sons, Ltd.
Direction‐of‐Change Financial Time Series Forecasting using a Similarity‐Based Classification Model
Authors: Skabar Andrew
Published: June 2013

A similarity‐based classification model is proposed whereby densities of positive and negative returns in a delay‐embedded input space are estimated from a graphical representation of the data using an eigenvector centrality measure, and subsequently combined under Bayes' theorem to predict the probability of upward/downward movements. Application to directional forecasting of the daily close price of the Dow Jones Industrial Average over a 20‐year out‐of‐sample period yields performance superior to random walk and logistic regression models, and on a par with that of multilayer perceptrons. A feature of the classifier is that it is parameter free, parameters entering the model only via the measure used to determine pairwise similarity between data points. This allows intuitions about the nature of time series to be elegantly integrated into the model. The recursive nature of eigenvector centrality makes it better able to deal with sparsely populated input spaces than conventional approaches based on density estimation. Copyright © 2013 John Wiley & Sons, Ltd.
Heterogeneous Asymmetric Dynamic Conditional Correlation Model with Stock Return and Range
Authors: Asai Manabu
Published: June 2013

The paper considers the return and range model with dynamic conditional correlations (DCC). The paper suggests the new specifications for the asymmetric effects on log‐volatilities and dynamic correlations, combined with long‐run dependences. The new DCC model can be estimated by the quasi‐maximum likelihood method. Empirical analysis on Nikkei 225, Hang Seng and Straits Times indices shows the daily, weekly and monthly pattern of asymmetric effects. For the period including the global financial crisis, the new DCC model provides plausible one‐step‐ahead forecasts of the VaR thresholds, and yields positive economic values of switching from other DCC models. Copyright © 2013 John Wiley & Sons, Ltd.
Comparison of Realized Measure and Implied Volatility in Forecasting Volatility
Authors: Han Heejoon , Park Myung D.
Published: June 2013

This paper compares the information content of realized measures constructed from high‐frequency data and implied volatilities from options in the context of forecasting volatility. The comparison is based on within‐sample and out‐of‐sample (over horizons of 1–22 days) forecasts of daily S&P 500 index return volatility. The paper adds to the findings of previous studies, by considering recent developments in the related practice and the literature. It is shown that, for within‐sample fitting, the realized measure is more informative than the implied volatility. In contrast, the implied volatility is more informative than the realized measure for out‐of‐sample forecasting, in particular for multi‐step‐ahead forecasting. Moreover, we show that it is helpful to use all the information provided by the realized measure and the implied volatility for the within‐sample fitting. For multi‐step‐ahead forecasting, however, it is better to use only the implied volatility. Copyright © 2013 John Wiley & Sons, Ltd.
Versuche zur einaxialen Druckfestigkeit geklebter Gesteinsproben
Authors: Becker Andreas , Vrettos Christos
Published: June 2013

Das Kleben von Bauteilen ist eine gängige Sanierungsmaßnahme im konstruktiven Ingenieurbau und im Bergbau, welche weiterentwickelt wird. Verkleben von Gestein stellt eine potentielle Methode der Sicherung von Felsböschungen dar, die jedoch bisher wenig Anwendung erfahren hat. In dem vorliegenden Beitrag wird das Kleben von typischen Gesteinsproben im Labor anhand von einaxialen Druckversuchen untersucht. Neben der Trennflächenneigung wurde die Temperatur beim Abbindevorgang variiert. Die Gegenüberstellung geklebter und intakter Gesteinsproben zeigt die Wirkung der Klebeverbindung.

Tests on the uniaxial strength of adhesive‐bonded rock samples. Adhesive bonding of structural parts is a common retrofit measure in structural and mining engineering, which is being further developed. Adhesive bonding of rock is a promising method of slope stabilization that received little attention hitherto. In this paper, the adhesive bonding of typical rock samples is investigated by means of uniaxial compression laboratory tests. Both, the orientation of the discontinuity as well as the temperature during the hardening process are varied in the tests. The comparison of bonded and intact rock samples shows the effect of the adhesive bond.
Prognose von Oberflächensetzungen beim Tunnelvortrieb – Teil II: Möglichkeiten und Grenzen der Finite‐Element‐Berechnung
Authors: Fillibeck Jochen
Published: June 2013

Die Prognose von Setzungen bzw. Sackungen oberhalb eines Tunnelvortriebs kann durch die Auswertung von Erfahrungen und Messungen aus vorangegangenen Tunnelbauprojekten – der empirischen Prognose – oder aber durch numerische Berechnungen erfolgen. Im Teil 1 der Veröffentlichung wurde das vom Autor vorgeschlagene empirische Prognoseverfahren vorgestellt, welches auf über 350 sorgfältig ausgewerteten Messquerschnitten basiert und mit dem sich unter vereinfachten Randbedingungen die sich über dem Tunnelvortrieb einstellenden Setzungen leicht berechnen lassen. Im nachfolgenden Teil 2 der Veröffentlichung wird auf numerische Berechnungsmethoden eingegangen, wobei zwischen 2D‐, 3D‐ und 4D‐FE‐Berechnungen unterschieden wird. Anhand von FE‐Berechnungen im Vergleich mit den Ergebnissen oben genannter Messquerschnitte werden Eignung, Möglichkeiten und Grenzen verschiedener Berechnungsverfahren dargestellt. Weiterhin wird durch Gegenüberstellung der Ergebnisse das im Teil 1 beschriebene empirische Prognoseverfahren bewertet, und schließlich werden Vorschläge unterbreitet, wann welches Verfahren vorteilhaft anwendbar ist.

Possibilities to predict the surface settlement during tunnelling in soil – Part II: application spectrum and limitations of the finite element calculation. The prediction of settlements over a tunnel excavation can be detected by the evaluation of measurement data available from previous tunnel project sites – the empirical prediction – or by numerical calculations. In part 1 of the publication, the empirical prediction method proposed by the author was introduced, which was derived by more than 350 carefully analyzed measuring sections. By this prediction method and under simplified boundary conditions, the tunnel induced settlement can be estimated easily. The following part 2 of the publication deals with numerical calculation methods. It is distinguished between 2D‐, 3D‐ and 4D‐FE‐Calculations. By comparing FE‐calculations with the results of the above mentioned measuring sections, the application spectrum and limitations of different calculation methods are shown. Further more, by comparison, the proposed empirical prediction method is evaluated. Finally the suitability of both methods according to the existing boundary conditions is discussed.
Interaction between magma intrusion and flank dynamics at Mt. Etna in 2008, imaged by integrated dense GPS and DInSAR data
Authors: Bonforte Alessandro , Guglielmino Francesco , Puglisi Giuseppe
Published: June 2013

Global positioning system (GPS) and differential interferometric synthetic aperture radar (DInSAR) data, collected from July 2007 to July 2008 on Mt. Etna, are analyzed to define the dynamics preceding and accompanying the onset of the eruption on 13 May 2008. Short‐ and long‐term comparisons have been made on both GPS and radar data, covering similar time windows. Thanks to the availability of three GPS surveys the year before the eruption onset, an increase in the seaward movement of the NE flank of the volcano has been detected in the few months before the dike intrusion. The GPS ground deformation pattern also shows a slight inflation centered on the western side of the volcano in the preeruptive long‐term comparison (from July 2007 to May 2008). The GPS has been integrated with DInSAR data by the SISTEM approach, to take advantage of the different methodologies and provide high spatial sampling of the 3‐D ground displacement pattern. We inverted the SISTEM results to model the pressure source causing the observed preeruptive inflation. The subsequent emplacement of the eruptive dike was imaged by two GPS surveys carried out on a dense network over the uppermost part of the volcano on 6 and 13 May, i.e., a few days before and a few hours after the beginning of the eruption. We inverted this comparison to define the position, geometry, and kinematics of the dike. The dike intrusion was also imaged by DInSAR data with temporal baselines of 2–3 months, which confirm strong displacements localized on the summit area, rapidly decreasing toward the middle flanks of the volcano, as detected by very short‐term GPS data; furthermore, the comparison between DInSAR and GPS data highlighted the presence of a depressurizing source localized beneath the upper southwestern area, acting just after the dike intrusion. Finally, the long‐period (1 year) GPS and DInSAR data were integrated by SISTEM to finely depict the 3‐D ground deformation pattern with the highest spatial resolution. The long‐period data allowed the complex kinematics of the volcano to be finely imaged and highlighting the interaction between flank dynamics and magma injection.
The 2004 Aceh‐Andaman Earthquake: Early clay dehydration controls shallow seismic rupture
Authors: Geersen Jacob , McNeill Lisa , Henstock Timothy J. , Gaedicke Christoph
Published: June 2013

The physical state of the shallow plate‐boundary fault governs the updip extent of seismic rupture during powerful subduction zone earthquakes and thus on a first order impacts on the tsunamigenic hazard of such events. During the 2004 Mw 9.2 Aceh‐Andaman Earthquake seismic rupture extended unusually far seaward below the accretionary prism causing the disastrous Indian Ocean Tsunami. Here we show that the formation of a strong bulk sediment section and a high fluid‐pressured predécollement, that likely enabled the 2004 rupture to reach the shallow plate‐boundary, result from thermally controlled diagenetic processes in the upper oceanic basement and overlying sediments. Thickening of the sediment section to >2 km ∼160 km seaward of the subduction zone increases temperatures at the sediment basement interface and triggers mineral transformation and dehydration (e.g., smectite‐illite) prior to subduction. The liberated fluids migrate into a layer that likely host high porosity and permeability and that is unique to the 2004 rupture area where they generate a distinct overpressured predécollement. Clay mineral transformation further supports processes of semilithification, induration of sediments, and coupled with compaction dewatering all amplified by the thick sediment section together strengthens the bulk sediments. Farther south, where the 2005 Sumatra Earthquake did not include similar shallow rupture, sediment thickness on the oceanic plate is significantly smaller. Therefore, similar diagenetic processes occur later and deeper in the subduction zone. Hence, we propose that shallow seismic rupture during the 2004 earthquake is primarily controlled by the thickness and composition of oceanic plate sediments.
The nexus between atmospheric rivers and extreme precipitation across Europe
Authors: Lavers David A. , Villarini Gabriele
Published: June 2013

Extreme precipitation and floods in Europe are a recurring natural hazard causing large socioeconomic damages. Here we investigate the connection between annual maxima (AM) daily precipitation at a pan‐European scale and atmospheric rivers (ARs), narrow filaments that convey the majority of the poleward water vapor transport within extratropical cyclones. We show that ARs are responsible for many AM precipitation days in Western Europe. The relationship is especially strong along the western European seaboard, with some areas having eight of their top 10 AM related to ARs. The effects of ARs are also seen as far inland as Germany and Poland. Southern Europe was most affected by ARs under negative North Atlantic Oscillation (NAO) conditions, whereas northern Europe was more associated with a positive relationship between ARs and an NAO‐type pattern. Our results suggest that ARs are critical in explaining the upper tail of the extreme precipitation distribution in Western Europe.
Resilience of Professional Counselors Following Hurricanes Katrina and Rita
Authors: Lambert Simone F. , Lawson Gerard
Published: June 2013

Professional counselors who provided services to those affected by Hurricanes Katrina and Rita completed the K6+ (screen for severe mental illness), the Posttraumatic Growth Inventory, and the Professional Quality of Life Scale. Results indicated that participants who survived the hurricanes had higher levels of posttraumatic growth than participants who served as volunteers. Both volunteer and survivor‐volunteer participants were susceptible to compassion fatigue. To further resiliency, self‐care strategies were found to minimize burnout, compassion fatigue, and vicarious traumatization.
Overcoming Adversity: High‐Achieving African American Youth's Perspectives on Educational Resilience
Authors: Williams Joseph M. , Bryan Julia
Published: June 2013

This qualitative multicase research study identified the home, school, and community factors and processes that contributed to the academic success of 8 urban, African American high school graduates from low‐income, single‐parent families. Ten main themes emerged: school‐related parenting practices, personal stories of hardship, positive mother–child relationships, extended family networks, supportive school‐based relationships, school‐oriented peer culture, good teaching, extracurricular school activities, social support networks, and out‐of‐school time activities. Implications for counselors are discussed.
Multicultural Counseling Beyond the Relationship: Expanding the Repertoire With Techniques
Authors: Hanna Fred J. , Cardona Betty
Published: June 2013

Multicultural counseling approaches variously focus on the counseling relationship. Relatively few discuss clinical techniques and strategies to any significant extent. This article explores enhancing multicultural counseling by offering an array of techniques and strategies based on addressing oppression and increasing psychological freedom. Techniques offered seek to internally free a person cognitively, affectively, and systemically using the Precursors Model of Change (Hanna, 2002). The goal is to help set a person free from oppressive, discriminatory systems and individuals.
Choosing Assessment Instruments for Bulimia Practice and Outcome Research
Authors: Sandberg Katie , Erford Bradley T.
Published: June 2013

Six commonly used instruments for assessment of eating disorders were analyzed. Effect size results from Erford et al.'s (2013) meta‐analysis for the treatment of bulimia nervosa were used to compare each scale's ability to measure treatment outcomes for bulimia nervosa. Effect size comparisons indicated higher overall effect sizes using the Eating Disorder Inventory and Eating Attitudes Test in assessing bulimia and the Eating Disorder Examination and the Body Shape Questionnaire in assessing body dissatisfaction.
Evaluation of an experimental Ti‐Co alloy for dental restorations
Authors: Wang Russell , Welsch Gerhard
Published: June 2013

Precision and surface quality of pure titanium (Ti) castings for dental and biomedical uses are limited because of the high melting temperature and the violent reactivity of Ti with mold materials during casting procedures. This feasibility study evaluates an experimental low‐melting Ti‐Co alloy in term of its microstructure and physical and mechanical properties. Tensile samples of Ti‐12 wt % Co alloy were cast under a protective argon atmosphere. The melting range of the cast samplers was determined. Cast samples were annealed at 1010°C for various time intervals in order to homogenize microstructures. Microstructures were examined by optical and scanning electron microscopy. Tensile strength and microhardness tests were performed and correlated with microstructures resulting from annealing processes. Ti2Co intermetallic compound coexisted with Ti‐Co solid solution in all samples. The melting range of the alloy was 1062–1088°C, which is 568°C lower than that of Ti. The thickness of the surface oxide scale on cast samples was dramatically reduced to 1–3 μm because of the low‐melting nature of the alloy. Solution treatment at 1010°C for 100 h yields the highest tensile strength. Ultimate tensile strength is measured from 852 to 1240 MPa which is stronger than currently used dental alloys. Microhardness values were ranged from 341 to 488 KHN and elongation was from 1.2 to 1.8%. Both microhardness and percentage elongation are similar to those of dental Co‐Cr alloys. One hundred hours of annealing dissolved dendritic boundaries and transformed the alloy to a more microductitle matrix, however, the intermetallic compound of Ti2Co remained. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1419–1427, 2013.
Effect of hydroxyapatite spheres, whiskers, and nanoparticles on mechanical properties of a model BisGMA/TEGDMA composite initially and after storage
Authors: Lezaja Maja , Veljovic Djordje N. , Jokic Bojan M. , Cvijovic‐Alagic Ivana , Zrilic Milorad M. , Miletic Vesna
Published: June 2013

This study investigated the effect of shape, size, and surface modification of hydroxyapatite (HAP) fillers on the degree of conversion (DC) and mechanical properties of a model BisGMA/TEGDMA composite initially and after 4 weeks of storage. Ten percent of conventional glass fillers were replaced by HAP spheres (Sph), silicon‐doped spheres (SphSi), whiskers (Wh), silicon‐doped whiskers (WhSi), and nanosized HAP particles (Nano). Spheres were specifically structured agglomerates consisting of a central void and radially orientated primary particles, whereas whiskers were compact monocrystals. DC, Vickers hardness (HV), flexural strength (Fs), flexural modulus (Ef), compressive strength (Cs), and compressive modulus (Ec) were tested. There were no significant differences in the DC between all tested groups. HV decreased by 5.4–17% with the addition of HAP, while Fs increased by 13.9–29% except in Nano group (decrease by 13%). After storage, Sph and SphSi groups showed similar HV, Ef, Cs and Ec and higher Fs than the control. The fracture mode of HAP spheres was through the central void whereas whiskers showed longitudinal delamination, transverse, and mixed fractures. HAP spheres with or without silicon‐ doping have a potential to be part of the filler content of dental composites. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1469–1476, 2013.
Parallelization of a multiconfigurational perturbation theory
Authors: Vancoillie Steven , Delcey Mickaël G. , Lindh Roland , Vysotskiy Victor , Malmqvist Per‐Åke , Veryazov Valera
Published: June 2013

In this work, we present a parallel approach to complete and restricted active space second‐order perturbation theory, (CASPT2/RASPT2). We also make an assessment of the performance characteristics of its particular implementation in the Molcas quantum chemistry programming package. Parallel scaling is limited by memory and I/O bandwidth instead of available cores. Significant time savings for calculations on large and complex systems can be achieved by increasing the number of processes on a single machine, as long as memory bandwidth allows, or by using multiple nodes with a fast, low‐latency interconnect. We found that parallel efficiency drops below 50% when using 8–16 cores on the shared‐memory architecture, or 16–32 nodes on the distributed‐memory architecture, depending on the calculation. This limits the scalability of the implementation to a moderate amount of processes. Nonetheless, calculations that took more than 3 days on a serial machine could be performed in less than 5 h on an InfiniBand cluster, where the individual nodes were not even capable of running the calculation because of memory and I/O requirements. This ensures the continuing study of larger molecular systems by means of CASPT2/RASPT2 through the use of the aggregated computational resources offered by distributed computing systems. © 2013 Wiley Periodicals, Inc.
Technology for rerefining used lube oils applied in Europe: a review
Authors: Kupareva Antonina , Mäki‐Arvela Päivi , Murzin Dmitry Yu.
Published: June 2013

The European oil rerefining industry is comprised of 28 plants treating waste oil, which represent one‐third in volume of the total European market for lubricants. The biggest European rerefineries with capacity greater than 40 000 tons/year apply various technologies for recycling of used oils from different sources. Used oil recycling technology has undergone significant changes over the past decade. With the newly developed rerefining technologies it is possible to produce higher quality base oil compared with the traditional and old acid clay methods. Currently in Europe the following re‐refining methods are widely used: solvent extraction (N‐methyl‐2‐pyrrolidone (Germany), Interline process (United Kingdom, Spain)); combined vacuum distillation and solvent extraction (Vaxon process (Denmark, Spain); hydroprocessing (Hylube process (Germany)); combined thin film evaporation and hydrofinishing (CEP process (Finland)); combined thermal de‐asphalting and hydrofinishing (Revivoil process (Italy, Poland, and Spain)). The majority of applied technologies in Europe is appropriate for rerefining of synthetic lubricating oils, which currently are replacing the conventional mineral lube oils due to their enhanced performance characteristics. However, for the rerefining technologies applying alkaline treatment (CEP, Vaxon) and hydrofinishing step (Cyclon, Snamprogetti, Revivoil) the amount of synthetic or semi‐synthetic oils based on esters in the feedstock should be eliminated, since these oils are less stable under alkali and hydrofinishing conditions. © 2013 Society of Chemical Industry
Long‐term trend of foF2 at a West African equatorial station linked to greenhouse gas increase and dip equator secular displacement
Authors: Gnabahou Doua A. , Elias Ana G. , Ouattara Frederic
Published: June 2013

Long‐term variability of foF2 at Ouagadougou station (12.4°N, 358.5°E; dip, 1.45°), a West African equatorial station, is studied, analyzing an annual mean data series at 12 LT for the period 1966–1998. After filtering the solar activity effect using Rz as a solar activity proxy, a downward trend of −0.015 MHz/yr is obtained, that is a ~5% decrease during the period of 33 years here considered, equivalent to a ~0.2%/yr. The downward trend is qualitatively consistent with a decreasing trend expected from increasing greenhouse gas concentration but greater than the ~0.003%/yr that would result from the 20% increase in CO2 that actually took place during the period of analysis. The foF2 decreasing trend is not in agreement with the trend expected from the secular variation of the dip angle at the location of Ouagadougou, but here an additional mechanism is considered, that is the secular movement of the dip equator toward Ouagadougou. This implies an approaching of the trough of the equatorial ionization anomaly and thus an foF2 decrease at Ouagadougou that is qualitatively in agreement with the observed trend.
HCFC‐22 emissions at global and regional scales between 1995 and 2010: Trends and variability
Authors: Fortems‒Cheiney A. , Chevallier F. , Saunois M. , Pison I. , Bousquet P. , Cressot C. , Wang H. J. , Yokouchi Y. , Artuso F.
Published: June 2013

HCFC‒22 (CHClF2, chlorodifluoromethane) is an ozone‒depleting substance, the consumption of which is controlled under the Montreal Protocol. Within a Bayesian inversion framework, we use measurements of HCFC‒22 atmospheric concentrations to constrain estimates of HCFC‒22 emissions, at the grid point 3.75°×2.5° and 8 day resolution, from January 1995 to December 2010. Starting from a new gridded bottom‒up inventory which is then optimized, our method shows continuously rising global emissions, from 182±11 Gg in 1995 to the maximum of 410±9 Gg in 2009. This is mainly due to an increase of emissions in developing regions, particularly in Eastern Asia, and occurs despite the current phase‒out in developed countries. The high temporal resolution of our inversion (8 day) allows to reveal some of the emission seasonality, the global posterior sources ranging from 25 Gg/month in November to 42 Gg/month in July, for example, in 2010.
Combining ground‐based with satellite‐based measurements in the atmospheric state retrieval: Assessment of the information content
Authors: Ebell K. , Orlandi E. , Hünerbein A. , Löhnert U. , Crewell S.
Published: June 2013

Remote sensing techniques offer the unique possibility to continuously and automatically monitor the atmospheric state from ground and space. Ground‐based microwave radiometers (MWRs), for example, are frequently used for temperature and humidity profiling of the lower troposphere. In order to improve the profiles in the middle and upper troposphere, further information is needed. In this respect, satellite measurements are expected to be very useful. In this study, the synergy benefit in temperature and humidity clear‐sky profiling using different combinations of state‐of‐the‐art microwave and infrared ground‐ and satellite‐based instruments is assessed. The synergy benefit is regarded as the information gain in light of ground‐based MWR observations together with some climatological a priori knowledge. The maximum information content for this kind of synergy is estimated by assuming optimum conditions, e.g., no forward model uncertainties and a horizontal homogeneous atmosphere. For a midlatitude site, the ground‐based MWR gives about 4.4 and 2.4 independent pieces of information on the temperature and humidity profile, respectively. For the temperature profile, the combination with Improved Atmospheric Sounding in the Infrared (IASI) and Atmospheric Microwave Sounding Unit‐A/Microwave Humidity Sounder (AMSU‐A/MHS) increases the information by a factor of about 1.8 and 1.5, respectively, with highest benefit in warm and/or humid conditions. The vertical information on humidity is significantly improved by highly spectrally resolved IR observations from ground or space when the atmosphere is cold and dry; the vertical information is more than tripled. If measurements from AMSU‐A/MHS, IASI, or Spinning Enhanced Visible and Infrared Imager are included, retrieval uncertainties in the middle and upper troposphere are significantly reduced by up to 68%.
A spatiotemporal analysis of U.S. station temperature trends over the last century
Authors: Capparelli V. , Franzke C. , Vecchio A. , Freeman M. P. , Watkins N. W. , Carbone V.
Published: June 2013

This study presents a nonlinear spatiotemporal analysis of 1167 station temperature records from the United States Historical Climatology Network covering the period from 1898 through 2008. We use the empirical mode decomposition method to extract the generally nonlinear trends of each station. The statistical significance of each trend is assessed against three null models of the background climate variability, represented by stochastic processes of increasing temporal correlation length. We find strong evidence that more than 50% of all stations experienced a significant trend over the last century with respect to all three null models. A spatiotemporal analysis reveals a significant cooling trend in the South‐East and significant warming trends in the rest of the contiguous U.S. It also shows that the warming trend appears to have migrated equatorward. This shows the complex spatiotemporal evolution of climate change at local scales.
Theoretical and empirical scale dependency of Z‐R relationships: Evidence, impacts, and correction
Authors: Verrier Sébastien , Barthès Laurent , Mallet Cécile
Published: June 2013

Estimation of rainfall intensities from radar measurements relies to a large extent on power‐laws relationships between rain rates R and radar reflectivities Z, i.e., Z = a*R^b. These relationships are generally applied unawarely of the scale, which is questionable since the nonlinearity of these relations could lead to undesirable discrepancies when combined with scale aggregation. Since the parameters (a,b) are expectedly related with drop size distribution (DSD) properties, they are often derived at disdrometer scale, not at radar scale, which could lead to errors at the latter. We propose to investigate the statistical behavior of Z‐R relationships across scales both on theoretical and empirical sides. Theoretically, it is shown that claimed multifractal properties of rainfall processes could constrain the parameters (a,b) such that the exponent b would be scale independent but the prefactor a would be growing as a (slow) power law of time or space scale. In the empirical part (which may be read independently of theoretical considerations), high‐resolution disdrometer (Dual‐Beam Spectropluviometer) data of rain rates and reflectivity factors are considered at various integration times comprised in the range 15 s – 64 min. A variety of regression techniques is applied on Z‐R scatterplots at all these time scales, establishing empirical evidence of a behavior coherent with theoretical considerations: a grows as a 0.1 power law of scale while b decreases more slightly. The properties of a are suggested to be closely linked to inhomogeneities in the DSDs since extensions of Z‐R relationships involving (here, strongly nonconstant) normalization parameters of the DSDs seem to be more robust across scales. The scale dependence of simple Z = a*R^b relationships is advocated to be a possible source of overestimation of rainfall intensities or accumulations. Several ways for correcting such scaling biases (which can reach >15–20% in terms of relative error) are suggested. Such corrections could be useful in some practical cases where Z‐R scale biases are significant, which is especially expected for convective rainfall.
Role of meteorological processes in ozone responses to emission controls in California's San Joaquin Valley
Authors: Jin Ling , Loisy Aurore , Brown Nancy J.
Published: June 2013

We conducted a first‐order sensitivity analysis to investigate ozone responses to precursor emissions and source contributions (local versus upwind) for California's San Joaquin Valley (SJV) under four distinct meteorology conditions of summer 2000 using a three‐dimensional photochemical transport model. Ozone‐limiting reagents, nitrogen oxides (NOx), or anthropogenic volatile organic compounds (VOCs) (AVOCs) and their transition regime were determined from ozone sensitivity coefficients and delineated spatially at high‐ozone locations in the SJV. In general, AVOC‐limited areas were located near urban centers, while NOx‐limited areas were located farther downwind. However, the spatial extent of AVOC‐limited areas varied with meteorology. Meteorological dependence of predominant ozone‐limiting precursors was found to vary significantly among different subregions within the SJV. Specifically, weaker dependences were identified for regions of the southern SJV located farther away from emission sources, where ozone chemistry was mostly limited by NOx for the episodes considered. Stronger dependences were identified for the central and northern SJV, where ozone chemistry can be limited by NOx or AVOC depending on meteorology. Source contributions to ozone sensitivities in the SJV were also investigated. Local sources were important for the eastern side of the central SJV, while upwind sources were also important (from ~40% to more than 50% of the total ozone sensitivities) for the western side of the valley, except for the most stagnant episode. Different contributing source regions were identified for the same VOC‐limited areas in the northern SJV, and these depended on the flow characteristics. The predominant ozone‐limiting reagent was found to exhibit less dependence on meteorology in the central and southern SJV as the baseline NOx emissions were reduced, ultimately causing ozone formation to be limited by NOx. In contrast, the VOC‐limited areas in the northern SJV continued to be influenced by meteorology for two of the episodes.
A novel melt stable and high tensile strength biopolymer (polyhydroxyalkanoates) from Bacillus megaterium (MTCC10086) and its characterization
Authors: Bora Limpon , Das Reshmi , Gohain Dibakar
Published: June 2013

In the present investigation, we have defined a novel biopolymer from Bacillus megaterium strain with novel melt stability, high tensile strength, and elongation to break properties higher to polypropylene and similar to polyethylene the polymers available commercially. The polymer was characterized with FTIR and XRD. The percent crystalinity was found to 44.09% with tensile strength 42 (Mpa) and elongation to break (%) 142 higher than polypropylene. The polymeric properties were confirmed by differential scanning calorimeter and universal testing.
Influence of topography on rainfall variability in Santiago Island, Cape Verde
Authors: Sanchez‐Moreno Juan Francisco , Mannaerts Chris M. , Jetten Victor
Published: June 2013

Cape Verde is a semi‐arid country conformed by a group of islands located off the west coast of Africa, with highly variable rainfall that appears during a single rainy season. Santiago Island, the biggest of the country, is characterized for abrupt changes of relief within small distances. The influence of geographic location and topographic parameters, such as slope gradient, exposition and elevation on the variability of rainfall in Santiago Island was studied using monthly rainfall data of 30 seasons (1981 to 2010), with daily rainfall data for 14 seasons (1997 to 2010). The number of rainfall days and the percentage of maximum daily rainfall within the monthly and seasonal totals were evaluated. Few rainy days can control the monthly and seasonal rainfall patterns of Santiago Island. Multivariate linear regressions among daily, monthly and seasonal rainfall and elevation, slope gradient, aspect, and geographic east and west coordinates as predictors were carried out. Elevation explains most of the variance in the rainfall. The coefficients of determination show an inverse relationship with the rainfall depth: moderate rainfall totals (120–150 mm monthly, 250–300 mm seasonal) produced the best correlations for seasonal and monthly rainfall, while very low (<50 mm for monthly, <200 mm for seasonal) and very high amounts (>250 mm for monthly, >350 mm for seasonal) resulted in poor correlations. Long‐term mean rainfall was interpolated using ordinary kriging and kriging with external drift. In Santiago Island, high and more extreme rainfall events are less influenced by elevation, while low and medium rainfall events are significantly influenced by orography, with most of the rainfall appearing on high elevations. Copyright © 2013 Royal Meteorological Society
Field Performance and Essential Oil Production of Mycorrhizal Rosemary in Restoration Low‐Nutrient Soils
Authors: Camprubi Amelia , Zárate Ingrith Angelica , Adholeya Alok , Lovato Paulo Emilo , Calvet Cinta
Published: June 2013

The establishment and growth of Rosmarinus officinalis L. under field conditions in two low‐nutrient‐content soils were evaluated, as well as the effect of arbuscular mycorrhizal (AM) fungi on essential oil production. The reclamation was conducted in two experimental sites: a limestone quarry and a wasteland soil, both surrounded by Mediterranean vegetation. Mycorrhizal R. officinalis plants inoculated with different AM fungal isolates were used to revegetate the sites. Pre‐transplant inoculation with mycorrhizal fungi resulted in an increased survival of R. officinalis with similar results in both experimental areas. Mycorrhizal inoculation enhanced plant growth, increased essential oil yield and improved the establishment of plants under field conditions. The results indicate that the presence of the symbiosis can accelerate plant growth and alter the biosynthesis of secondary metabolites, thus improving the yield of medicinal plant extracts. It also confirmed the importance of selecting plant/symbiont combinations adapted to the environmental constraints of low‐nutrient‐content soils to design a successful application of mycorrhizal technology in marginal soils. Copyright © 2013 John Wiley & Sons, Ltd.
Lipids in infant formulas: Current and future innovations
Authors: Long Amy C. , Kaiser Jennifer L. , Katz Gary E.
Published: June 2013

Lipids in infant formulas are designed to mimic the composition of human milk and/or approximate the performance of the breastfed infant. Human milk lipids exhibit a complex, highly variable nature, varying by population, dietary intake, time of day, length of feeding and others. Continued understanding and characterization of human milk lipids has led to infant formula innovations aimed at a better comparison to human milk and/or improved dietary lipid utilization in the formula‐fed infant. The underlying aim of such innovation is the generation of outcomes as comparable to human milk feeding as possible. The present paper briefly reviews the current understanding of human milk lipid composition, with a focus on how this knowledge drives current and future innovations in the area of infant formula lipids.
Low‐level laser therapy for fat layer reduction: A comprehensive review
Authors: Avci Pinar , Nyame Theodore T. , Gupta Gaurav K. , Sadasivam Magesh , Hamblin Michael R.
Published: June 2013

Background and Objective

Low‐level laser (light) therapy (LLLT) is a noninvasive, nonthermal approach to disorders requiring reduction of pain and inflammation and stimulation of healing and tissue regeneration. Within the last decade, LLLT started being investigated as an adjuvant to liposuction, for noninvasive body contouring, reduction of cellulite, and improvement of blood lipid profile. LLLT may also aid autologous fat transfer procedures by enhancing the viability of adipocytes. However the underlying mechanism of actions for such effects still seems to be unclear. It is important, therefore, to understand the potential efficacy and proposed mechanism of actions of this new procedure for fat reduction.

Materials and Methods

A review of the literature associated with applications of LLLT related to fat layer reduction was performed to evaluate the findings from pre‐clinical and clinical studies with respect to the mechanism of action, efficacy, and safety.

Results

The studies as of today suggest that LLLT has a potential to be used in fat and cellulite reduction as well as in improvement of blood lipid profile without any significant side effects. One of the main proposed mechanism of actions is based upon production of transient pores in adipocytes, allowing lipids to leak out. Another is through activation of the complement cascade which could cause induction of adipocyte apoptosis and subsequent release of lipids.

Conclusion

Although the present studies have demonstrated safety and efficacy of LLLT in fat layer reduction, studies demonstrating the efficacy of LLLT as a stand‐alone procedure are still inadequate. Moreover, further studies are necessary to identify the mechanism of action. Lasers Surg. Med. 45:349–357, 2013. © 2013 Wiley Periodicals, Inc.
Surgical site infections in liver transplant recipients in the model for end-stage liver disease era: An analysis of the epidemiology, risk factors, and outcomes
Authors: Freire Maristela Pinheiro , Soares Oshiro Isabel C. V. , Bonazzi Patricia Rodrigues , Guimarães Thais , Ramos Figueira Estela Regina , Bacchella Telésforo , Costa Silvia Figueiredo , Carneiro D'Albuquerque Luiz Augusto , Abdala Edson
Published: June 2013

In recipients of liver transplantation (LT), surgical site infection (SSIs) are among the most common types of infection occurring in the first 60 days after LT. In 2007, the Model for End-Stage Liver Disease (MELD) scoring system was adopted as the basis for prioritizing organ allocation. Patients with higher MELD scores are at higher risk for developing SSIs as well as other health care–associated infections. However, there have been no studies comparing the incidence of SSIs in the pre-MELD era with the incidence in the period since its adoption. Therefore, the objectives of this study were to evaluate the incidence, etiology, epidemiology, and outcomes of post-LT SSIs in those 2 periods and to identify risk factors for SSIs. We evaluated all patients who underwent LT over a 10-year period (2002–2011). SSI cases were identified through active surveillance. The primary outcome measure was an SSI during the first 60 days after LT. Risk factors were analyzed via logistic regression, and 60-day survival rates were evaluated via Cox regression. We evaluated 543 patients who underwent LT 597 times. The SSI rates in the 2002–2006 and 2007–2011 periods were 30% and 24%, respectively (P = 0.21). We identified the following risk factors for SSIs: retransplantation, the transfusion of more than 2 U of blood during LT, dialysis, cold ischemia for >400 minutes, and a cytomegalovirus infection. The overall 60-day survival rate was 79%. Risk factors for 60-day mortality were retransplantation, dialysis, and a longer surgical time. The use of the MELD score modified the incidence and epidemiology of SSIs only during the first year after its adoption. Risks for SSIs were related more to intraoperative conditions and intercurrences after LT than to a patient's status before LT. Liver Transpl 19:1011–1019, 2013. © 2013 AASLD.
Synthesis of New Poly(ether ketone)s Derived from Biobased Diols
Authors: Abderrazak Hana Ben , Fildier Aurélie , Romdhane Hatem Ben , Chatti Saber , Kricheldorf Hans R.
Published: June 2013

A new class of poly(ether ketone)s (PEKs) is prepared by polycondensation of various diols produced from biomass and various difluoro aromatics. After optimization of the reaction conditions, polycondensation of isosorbide and 4,4′‐difluorodiphenylketone (2a) gives PEK1 with a high yield, moderate viscosity (0.31 dL g−1), and a glass‐transition temperature (Tg) of 170 °C. The optimum conditions are applied to the synthesis of a series of PEKs (PEK 2–9) from difluoro agents and sugar diols. The polycondensation of isomannide (1b) with 1,4‐di(p‐fluorobenzoyl)benzene (2b) gives the best results with an inherent viscosity of 0.52 dL g−1 and the mass spectrum shows an abundance of cyclic structures. Similar conditions are used for the preparation of high‐molar‐mass copoly(ether ketone)s from a stoechiometric mixture of isosorbide/bisphenol‐A.

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Polyaniline as a Material for Hydrogen Storage Applications
Authors: Attia Nour F. , Geckeler Kurt E.
Published: June 2013

The main challenge of commercialization of the hydrogen economy is the lack of convenient and safe hydrogen storage materials, which can adsorb and release a significant amount of hydrogen at ambient conditions. Finding and designing suitable cost‐effective materials are vital requirements to overcome the drawbacks of investigated materials. Because of its outstanding electronic, thermal, and chemical properties, the electrically conducting polyaniline (PANI) has a high potential in hydrogen storage applications. In this review, the progress in the use of different structures of conducting PANI, its nanocomposites as well as activated porous materials based on PANI as hydrogen storage materials is presented and discussed. The effect of the unique electronic properties based on the π‐electron system in the backbone of these materials in view of the hydrogen uptake and the relevant mechanisms are highlighted.

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pH‐Switchable Macroscopic Assembly through Host–Guest Inclusion
Authors: Yuan Qi‐Juan , Wang Yi‐Fu , Li Jian‐Hu , Li Bang‐Jing , Zhang Sheng
Published: June 2013

A novel pH‐switchable macroscopic assembly is reported using alginate‐based hydrogels functionalized with host (α‐cyclodextrin, αCD) and guest (diethylenetriamine, DETA) moieties. Since the interaction of αCD and DETA is pH sensitive, the host hydrogel and guest hydrogel could adhere together when the pH is 11.5 and separate when the pH is 7.0. Furthermore, this pH‐controlled adhesion and dissociation shows a good reversibility. The host and guest polymers have good biocompatibility; therefore, this pH‐sensitive macroscopic assembly shows great potential in biotechnological and biomedical applications.

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Flow‐enhanced Crystallization Kinetics of iPP during Cooling at Elevated Pressure: Characterization, Validation, and Development
Authors: van Erp Tim B. , Roozemond Peter C. , Peters Gerrit W. M.
Published: June 2013

Using dilatometry combined with shear flow at conditions comparable to realistic processing conditions, the flow‐induced crystallization of polymers is modelled. The model describes the kinetics of quiescent nucleation, flow‐enhanced point nucleation, fibrillar growth, and the time evolution of the dimensions of the resulting crystalline structures. The growth rate of nuclei is coupled to the backbone stretch of a mode with a relaxation time representative of the average of the molecular weight distribution. The eXtended Pom‐Pom (XPP) model is used to calculate the backbone stretches from flow conditions. Three important model parameters are determined over a broad range of temperatures, pressures, and shear rates for a fixed shear time; a prefactor to the creation rate of flow‐induced nucleation, a prefactor to the shish growth rate, and the critical molecular stretch defining the transition between flow‐enhanced nucleation and flow‐induced crystallization of oriented fibrilar structures. Excellent agreement is obtained between calculated and experimentally determined crystallization kinetics of iPP. Moreover, the extended experimental dataset leads to an important adaption of the model, i.e., a new criterion for the initiation of shish growth.