bluuebunny/crossref_metadata_2025_split huggingface dataset:
Memory aware load balance strategy on a parallel branch‐and‐bound application
Authors: Silva Juliana M.N. , Boeres Cristina , Drummond Lúcia M.A. , Pessoa Artur A. 
Published: April 2014

AbstractThe latest trends in high performance computing systems show an increasing demand on the use of a large scale multicore system in an efficient way so that high compute‐intensive applications can be executed reasonably well. However, the exploitation of the degree of parallelism available at each multicore component can be limited by the poor utilization of the memory hierarchy. Actually, the multicore architecture introduces some distinct features that are already observed in shared memory and distributed environments. One example is that subsets of cores can share different subsets of memory. In order to achieve high performance, it is imperative that a careful allocation scheme of an application is carried out on the available cores, based on a scheduling specification that considers not only processors characteristics but also memory contention. This paper proposes a multicore cluster representation that captures relevant performance characteristics in multicores systems such as the influence of memory hierarchy and contention on application performance. Improved performance was achieved by a branch‐and‐bound application applied to the partitioning sets problem that incorporated a memory aware load balancing strategy based on the proposed multicore cluster representation. An in‐depth analysis on this application execution showed its applicability to modern systems. Copyright © 2014 John Wiley & Sons, Ltd.
Self‐Propelled Janus Mesoporous Silica Nanomotors with Sub‐100 nm Diameters for Drug Encapsulation and Delivery
Authors: Xuan Mingjun , Shao Jingxin , Lin Xiankun , Dai Luru , He Qiang 
Published: April 2014

AbstractThe synthesis of an innovative self‐propelled Janus nanomotor with a diameter of about 75 nm that can be used as a drug carrier is described. The Janus nanomotor is based on mesoporous silica nanoparticles (MSNs) with chromium/platinum metallic caps and propelled by decomposing hydrogen peroxide to generate oxygen as a driving force with speeds up to 20.2 μm s−1 (about 267 body lengths per second). The diffusion coefficient (D) of nanomotors with different H2O2 concentrations is calculated by tracking the movement of individual particles recorded by means of a self‐assembled fluorescence microscope and is significantly larger than free Brownian motion. The traction of a single Janus MSN nanomotor is estimated to be about 13.47×10−15 N. Finally, intracellular localization and drug release in vitro shows that the amount of Janus MSN nanomotors entering the cells is more than MSNs with same culture time and particle concentrations, meanwhile anticancer drug doxorubicin hydrochloride loaded in Janus MSNs can be slowly released by biodegradation of lipid bilayers in cells.
Bottom‐up performance analysis of focal‐plane mixed‐signal hardware for Viola–Jones early vision tasks
Authors: Fernández‐Berni Jorge , Carmona‐Galán Ricardo , del Río Rocío , Rodríguez‐Vázquez Angel 
Published: April 2014

SummaryFocal‐plane mixed‐signal arrays have traditionally been designed according to the general claim that moderate accuracy in processing is affordable. The performance of their circuitry has been analyzed in these terms without a comprehensive study of the ultimate consequences of such moderate accuracy. In this paper, for the first time to the best of our knowledge, we do carry out this study. We move expectable performance of mixed‐signal image processing hardware directly into the vision algorithm making use of it. This permits to close a wider design loop, enabling a more aggressive design of this kind of hardware provided that the algorithm, at the highest level—semantic interpretation of the scene—, can afford it. Thus, we present a thorough analysis of the non‐idealities associated with the implementation of a QVGA array tailored for the distinctive characteristics of the Viola–Jones processing framework. The resulting deviation models are then introduced in the processing flow of this framework provided by the OpenCV library. We have found, contrary to what could be expected, that these deviations do not necessarily degrade the performance of the Viola–Jones algorithm. They could be even beneficial for certain high‐level specifications. Additionally, we demonstrate the architectural advantages of our approach: exploitation of focal‐plane distributed memory and ultra‐low‐power operation. Copyright © 2014 John Wiley & Sons, Ltd.
Fin whale MDH‐1 and MPI allozyme variation is not reflected in the corresponding DNA sequences
Authors: Olsen Morten Tange , Pampoulie Christophe , Daníelsdóttir Anna K. , Lidh Emmelie , Bérubé Martine , Víkingsson Gísli A. , Palsbøll Per J. 
Published: April 2014

AbstractThe appeal of genetic inference methods to assess population genetic structure and guide management efforts is grounded in the correlation between the genetic similarity and gene flow among populations. Effects of such gene flow are typically genomewide; however, some loci may appear as outliers, displaying above or below average genetic divergence relative to the genomewide level. Above average population, genetic divergence may be due to divergent selection as a result of local adaptation. Consequently, substantial efforts have been directed toward such outlying loci in order to identify traits subject to local adaptation. Here, we report the results of an investigation into the molecular basis of the substantial degree of genetic divergence previously reported at allozyme loci among North Atlantic fin whale (Balaenoptera physalus) populations. We sequenced the exons encoding for the two most divergent allozyme loci (MDH‐1 and MPI) and failed to detect any nonsynonymous substitutions. Following extensive error checking and analysis of additional bioinformatic and morphological data, we hypothesize that the observed allozyme polymorphisms may reflect phenotypic plasticity at the cellular level, perhaps as a response to nutritional stress. While such plasticity is intriguing in itself, and of fundamental evolutionary interest, our key finding is that the observed allozyme variation does not appear to be a result of genetic drift, migration, or selection on the MDH‐1 and MPI exons themselves, stressing the importance of interpreting allozyme data with caution. As for North Atlantic fin whale population structure, our findings support the low levels of differentiation found in previous analyses of DNA nucleotide loci.
Predicting future coexistence in a North American ant community
Authors: Bewick Sharon , Stuble Katharine L. , Lessard Jean‐Phillipe , Dunn Robert R. , Adler Frederick R. , Sanders Nathan J. 
Published: April 2014

AbstractGlobal climate change will remodel ecological communities worldwide. However, as a consequence of biotic interactions, communities may respond to climate change in idiosyncratic ways. This makes predictive models that incorporate biotic interactions necessary. We show how such models can be constructed based on empirical studies in combination with predictions or assumptions regarding the abiotic consequences of climate change. Specifically, we consider a well‐studied ant community in North America. First, we use historical data to parameterize a basic model for species coexistence. Using this model, we determine the importance of various factors, including thermal niches, food discovery rates, and food removal rates, to historical species coexistence. We then extend the model to predict how the community will restructure in response to several climate‐related changes, such as increased temperature, shifts in species phenology, and altered resource availability. Interestingly, our mechanistic model suggests that increased temperature and shifts in species phenology can have contrasting effects. Nevertheless, for almost all scenarios considered, we find that the most subordinate ant species suffers most as a result of climate change. More generally, our analysis shows that community composition can respond to climate warming in nonintuitive ways. For example, in the context of a community, it is not necessarily the most heat‐sensitive species that are most at risk. Our results demonstrate how models that account for niche partitioning and interspecific trade‐offs among species can be used to predict the likely idiosyncratic responses of local communities to climate change.
Hybridization in a warmer world
Authors: Chunco Amanda J. 
Published: April 2014

AbstractClimate change is profoundly affecting the evolutionary trajectory of individual species and ecological communities, in part through the creation of novel species assemblages. How climate change will influence competitive interactions has been an active area of research. Far less attention, however, has been given to altered reproductive interactions. Yet, reproductive interactions between formerly isolated species are inevitable as populations shift geographically and temporally as a result of climate change, potentially resulting in introgression, speciation, or even extinction. The susceptibility of hybridization rates to anthropogenic disturbance was first recognized in the 1930s. To date, work on anthropogenically mediated hybridization has focused primarily on either physical habitat disturbance or species invasion. Here, I review recent literature on hybridization to identify how ecological responses to climate change will increase the likelihood of hybridization via the dissolution of species barriers maintained by habitat, time, or behavior. Using this literature, I identify several cases where novel hybrid zones have recently formed, likely as a result of changing climate. Future research should focus on identifying areas and taxonomic groups where reproductive species interactions are most likely to be influenced by climate change. Furthermore, a better understanding of the evolutionary consequences of climate‐mediated secondary contact is urgently needed. Paradoxically, hybridization is both a major conservation concern and an important source of novel genetic and phenotypic variation. Hybridization may therefore both contribute to increasing rates of extinction and stimulate the creation of novel phenotypes that will speed adaptation to novel climates. Predicting which result will occur following secondary contact will be an important contribution to conservation for many species.
New yeast isolate Pichia caribbica synthesizes xylolipid biosurfactant with enhanced functionality
Authors: Joshi‐Navare Kasturi , Singh Pradeep Kumar , Prabhune Asmita A. 
Published: April 2014

Sophorolipids (SL) belong to a class of glycolipidic biosurfactants suitable for a wide range of applications. The structural diversity in SL gives rise to variation in physicochemical and biological properties. To achieve the less explored head group diversity in sophorolipid structure, a new xylose fermenting yeast Pichia caribbica has been employed for biosurfactant production. The media and fermentation parameters have been optimized to achieve maximum yield of 7.48 g/L. The physicochemical properties of the xylolipid biosurfactant have been assessed. It reduced the surface tension of distilled water from 70 to 35.9 mN/m with the low critical micellar concentration (CMC) 1.0 mg/L as compared to typical SL (reported CMC range 40–100 mg/L). Structural characterization was done using FTIR and HR‐MS to identify the structure. 17‐L‐[(β‐D‐xylopyranosyl)‐oxy]‐Δ9‐heptadecanoic acid correlated to m/z 415 majorly constituted the product. Control experiment was performed in which glucose was provided as the hydrophilic carbon. This product was also subjected to HR‐MS analysis to determine its chemical nature and found to be different from xylolipid. Presence of xylose as head group was anticipated to give altered physicochemical and biological activities and indeed a low CMC value and better inhibitory action was demonstrated against Staphylococcus aureus.Practical applications: Sophorolipids produced by microbial sources have several advantageous properties over commercial petroleum‐based surfactants including biodegradability, environmentally friendly nature, and low toxicity. Here, we have attempted to modify the hydrophilic head group by incorporating xylose in place of glucose. This molecule will also behave differently in response to different stimuli. Stimuli‐responsive surfactants are a class of compounds with applications in stabilization of emulsions, suspensions or foams, drug encapsulation and delivery, hard‐surface cleaning, personal care applications.New yeast isolate – Pichia caribbica was provided with xylose and oleic acid. This resulted in synthesis of glycolipidic molecule different from typical sophorolipid synthesized by Candida bombicola. Xylose was incorporated as head group, i.e., hydrophilic moiety in place of glucose. The variation in structure imparted better surface tension lowering activity thus showed low CMC value. Also antibacterial activity was enhanced.
Antioxidant activity of phosphatidyl derivatives of hydroxytyrosol in edible oils
Authors: Martin Diana , Garcia‐Serrano Alba , Casado Víctor , Vázquez Luis , Reglero Guillermo , Torres Carlos F. 
Published: April 2014

A comparative study of the antioxidant activity of hydroxytyrosol (HT) and phosphatidyl derivatives of hydroxytyrosol (PHT) added at increasing concentrations to diverse edible oils (lard oil, refined olive oil, and diacylglycerol‐rich oil) was performed. Antioxidant activity index was estimated as the ratio of induction time in presence of the compounds to induction time in their absence, after oxidation under Rancimat conditions. Tocopherol (TOC) and phosphatydilcholine (PC) were used as reference, and combinations PHT:TOC, PHT:PC, HT:TOC, and PC:TOC were also tested. PHT and HT showed a protective effect as the added concentration of antioxidants increased. However, the protective effect of PHT was superior to HT for olive oil and diacylglycerol oil, and similar to HT for lard oil. The magnitude of the protection of both PHT and HT was higher in lard oil, followed by olive oil and the poorest protection was for diacylglycerol oil. Both HT and PHT were superior to TOC. Furthermore, PC showed a lack of antioxidant activity compared to PHT. A lack of synergism between the combinations of antioxidants was found.Practical applications: Including phosphatidyl derivatives of hydroxytyrosol in edible oils provides two advantages. First, they serve as a source of hydroxytyrosol and second they stabilize the lipid matrix, and in this respect the phosphatidyl derivatives perform better than hydroxytyrosol or tocopherols.A comparative study of the antioxidant activity of hydroxytyrosol (HT) and phosphatidyl derivatives of HT (PHT) added at increasing concentrations to diverse edible oils (lard oil, refined olive oil, and diacylglycerol‐rich oil) was performed. Tocopherol as reference was also tested. PHT might be included in edible oils with the double strategy to offer a source of HT and, at the same, stabilize the own lipid matrix, even in a superior mode than HT or the standard tocopherol. Nevertheless, the particularity of each individual oil would determine the magnitude of the protection.
Laboratory‐scale optimization of olive oil extraction: Simultaneous addition of enzymes and microtalc improves the yield
Authors: Peres Fátima , Martins Luisa L. , Ferreira‐Dias Suzana 
Published: April 2014

The aim of this work was to optimize olive oil extraction, at laboratory‐scale (Abencor system), from fruits of “Cobrançosa” and “Galega Vulgar” Portuguese cultivars, either in the absence or in the presence of enzymes and natural microtalc. Using a Placket–Burman design to select significant variables followed by a central composite rotatable design (CCRD), Abencor operation conditions were optimized: no water addition in 30 min malaxation and 14% w/w water addition at 50°C in centrifugation. The combined effects of the concentrations of natural microtalc (MT: 0.04–0.46 w‐%) and enzyme preparation (E: 0.003–0.117 w‐%) added at the beginning of malaxation, on quality criteria, total phenols and chlorophyll pigments concentrations, and on oil extraction yield, were investigated using a CCRD. The results showed that the addition of both an enzyme preparation and natural microtalc could enhance olive oil yield (up to 34% for 0.4–0.5% of microtalc and 0.1% of enzymes for “Galega Vulgar”) without any effect on quality of the obtained virgin olive oil.Practical applications: Abencor system is the most used laboratory‐scale installation in olive oil technology to carry out trials that would be very difficult to perform at industrial scale. This study presents an optimization of the Abencor extraction process, as well as the optimization of extraction with two adjuvants, enzymes and natural microtalc, using two different cultivars. The effect of E and/or MT addition depend on the cultivar. However, an improvement in extractability was always found for both cultivars. This study shows that for “Cobrançosa” olives, considering both olive oil yield and economical aspects, the chosen conditions are 0.05–0.15% of microtalc in the absence of added enzymes. For “Galegar Vulgar” olives, the highest extractability is observed under the presence of enzyme preparation amount higher than 0.10% and microtalc amount of 0.4–0.5%.The simultaneous addition of an enzyme preparation and natural microtalc could enhance olive oil yield. The use of adjuvants, and their respective amounts, must be adjusted to each cultivar.
Modeling of the composite action in fully restrained beam‐to‐column connections: implications in the seismic design and collapse capacity of steel special moment frames
Authors: Elkady Ahmed , Lignos Dimitrios G. 
Published: April 2014

SUMMARYThis paper investigates the effect of the composite action on the seismic performance of steel special moment frames (SMFs) through collapse. A rational approach is first proposed to model the hysteretic behavior of fully restrained composite beam‐to‐column connections, with reduced beam sections. Using the proposed modeling recommendations, a system‐level analytical study is performed on archetype steel buildings that utilize perimeter steel SMFs, with different heights, designed in the West‐Coast of the USA. It is shown that in average, the composite action may enhance the seismic performance of steel SMFs. However, bottom story collapse mechanisms may be triggered leading to rapid deterioration of the global strength of steel SMFs. Because of composite action, excessive panel zone shear distortion is also observed in interior joints of steel SMFs designed with strong‐column/weak‐beam ratios larger than 1.0. It is demonstrated that when steel SMFs are designed with strong‐column/weak‐beam ratios larger than 1.5, (i) bottom story collapse mechanisms are typically avoided; (ii) a tolerable probability of collapse is achieved in a return period of 50 years; and (iii) controlled panel zone yielding is achieved while reducing the required number of welded doubler plates in interior beam‐to‐column joints. Copyright © 2014 John Wiley & Sons, Ltd.
Construct validity of the mini mental state examination across time in a sample with low‐education levels: 10‐year follow‐up of the Bambuí Cohort Study of Ageing
Authors: Castro‐Costa Érico , Dewey Michael E. , Uchôa Elizabeth , Firmo Josélia O. A. , Lima‐Costa Maria Fernanda , Stewart Robert 
Published: April 2014

ObjectiveThe study aims to investigate whether longitudinal data on the structure of the mini mental state examination (MMSE) collected in an older Brazilian cohort support factorial invariance over time.DesignAnalysis of 10‐year data from a community‐based cohort study was performed.SettingThe study took place in Bambuí, Brazil.ParticipantsThe study sample comprised 1558 (89.4%) of all eligible 1742 elderly residents.MeasurementsA standard Brazilian version of the MMSE was used.ResultsA five‐factor solution (developed on the baseline of the cohort) either with no constraints or with loadings constrained to equality across time provided a reasonable fit for the MMSE. A comparison between both models suggested that the model with no constraints was superior. However, the five absolute goodness‐of‐fit indices suggest that the fully constrained model was also adequate and did not differ substantively from the model without any restriction.ConclusionThe structure of the MMSE remained relatively unchanged across the 10 measurement times, thus providing evidence for the good construct validity of the scale across time. Copyright © 2014 John Wiley & Sons, Ltd.
Sickness Absence, Moral Hazard, and the Business Cycle
Authors: Pichler Stefan 
Published: April 2014

SummaryThe procyclical nature of sickness absence has been documented by many scholars in literature. So far, explanations have been based on labor force composition and reduced moral hazard caused by fear of job loss during recessions. In this paper, we propose and test a third mechanism caused by reduced moral hazard during booms and infections. We suggest that the workload is higher during economic booms and thus employees have to go to work despite being sick. In a theoretical model focusing on infectious diseases, we show that this will provoke infections of coworkers leading to overall higher sickness absence during economic upturns. Using state‐level aggregated data from 112 German public health insurance funds (out of 145 in total), we find that sickness absence due to infectious diseases shows the largest procyclical pattern, as predicted by our theoretical model. Copyright © 2014 John Wiley & Sons, Ltd.
Normal Mode Dynamics Comparison of Proteins
Authors: Tobi Dror 
Published: April 2014

AbstractSequence and structure comparisons are fundamental techniques that enable exploration of the sequence and structural spaces of proteins. Homology detection, function prediction, and protein classification rely on these techniques. However, protein structures are dynamic, rather than static, and such protein dynamics play a key role in a wide range of biological activities. Therefore, protein dynamics comparison algorithms may shed light on the relationship between proteins′ dynamics and function. Here, we review different strategies for comparing dynamics of proteins. Special emphasis is given to newly developed algorithms that compare dynamics of proteins with no apparent sequence or structural similarity and to the qualitative differences between these algorithms.
Polyfurans: A Computational Study
Authors: Sharma Sagar , Zamoshchik Natalia , Bendikov Michael 
Published: April 2014

AbstractPolyfurans and furan‐based polymers have recently emerged as a new class of conjugated materials. We undertook the first comprehensive computational study of polyfurans, especially doped polyfurans, and systematically compared their properties with those of the corresponding polythiophenes. Parent polyfuran has higher highest occupied crystal orbit and lowest unoccupied crystal orbit energies (by 0.25 and 0.61 eV, respectively), as well as a higher band gap (by 0.36 eV) and significantly larger twisting energy than that of polythiophenes. Doping of polyfuran and polythiophene was less exothermic than polyselenophene in all cases. For thermodynamic reasons, polyfurans should be easier to dope lightly than polythiophenes, whereas at heavy doping levels polyfurans and polythiophenes should be doped with similar ease.