bluuebunny/crossref_metadata_2025_split huggingface dataset:
A metamaterial having a frequency dependent elasticity tensor and a zero effective mass density
Authors: Milton Graeme , Seppecher Pierre 
Published: March 2012

AbstractWithin the context of linear elasticity we show that a two‐terminal network of springs and masses, can respond exactly the same as a normal spring, but with a frequency dependent spring constant. A network of such springs can have a frequency dependent effective elasticity tensor but zero effective mass density. The internal masses influence the elasticity tensor, but do not contribute to the effective mass density.
Optically erasing disorder in semiconductor microcavities using polariton–polariton interactions
Authors: Liew T. C. H. 
Published: March 2012

AbstractThrough resonant coherent optical excitation of upper branch polaritons in semiconductor microcavities, an effective screening of the disorder potential experienced by lower branch polaritons is predicted. The effect is due to polariton–polariton interactions, which generate bistability for the upper‐polariton states and introduce an effective potential for lower‐polaritons. The effect represents a simple tool to improve the characteristics of devices operating in the low density regime.
DEFF: a new architecture for private online social networks
Authors: Raji Fatemeh , Miri Ali , Jazi Mohammad Davarpanah , Malek Behzad 
Published: March 2012

ABSTRACTIn recent years, online social networks (OSNs) have had explosive growth in numbers and popularity. In an OSN, users communicate with each other and share information about themselves. However, limiting the flow of private information across OSNs is very important especially because most OSNs provide insufficient privacy settings to control information leakage. In this paper, we propose a mediated architecture for OSNs that protects users' information from both the OSN provider and unauthorized OSN users. Our proposed approach delegates most of the computation tasks to a semi‐trusted proxy server. We exploit a simplified broadcast encryption method in order to design a dynamic, efficient, flexible, and fine‐grained (DEFF) control system. In the proposed DEFF system, users are allowed to cryptographically categorize their friends into different relations and to share data with arbitrary groups of them. The results of our analysis indicate that the DEFF system fully protects users' privacy and is very efficient in terms of communication and computation complexities. Copyright © 2012 John Wiley & Sons, Ltd.
A security‐enhanced key agreement protocol based on chaotic maps
Authors: Chen Tzung‐Her , Wang Bing‐Jian , Tu Tai‐Yuan , Wang Chih‐Hung 
Published: March 2012

ABSTRACTRecently, Tseng et al. proposed a novel key agreement protocol based on chaotic maps. They claimed that their protocol achieved the session key agreement between server and users with user's anonymity and security. Although Niu and Wang proposed a new improvement, the presented scheme involved an additional participant, the trusted party, in such a way that the system cost raised a lot. To inherit the superiority of Tseng et al. but remove the security weaknesses, it is worthwhile to point out the kernel of drawback in the scheme of Tseng et al. and, further, propose a security‐enhanced scheme by overcoming the drawback with slight modifications. Copyright © 2012 John Wiley & Sons, Ltd.
Regression verification: proving the equivalence of similar programs
Authors: Godlin Benny , Strichman Ofer 
Published: March 2012

SUMMARYProving the equivalence of successive, closely related versions of a program has the potential of being easier in practice than functional verification, although both problems are undecidable. There are three main reasons for this claim: (i) it circumvents the problem of specifying what the program should do; (ii) the problem can be naturally decomposed and hence is computationally easier; and (iii) there is an automatic invariant that enables to prove equivalence of loops and recursive functions in most practical cases. Theoretical and practical aspects of this problem are considered. Copyright © 2012 John Wiley & Sons, Ltd.
Purification and characterization of an organic-solvent-tolerant cellulase from a halotolerant isolate, Bacillus sp. L1
Authors: Li Xin , Yu Hui-Ying 
Published: March 2012

Abstract
A halotolerant isolate Bacillus sp. L1 producing extracellular cellulase was isolated from Yuncheng, China. Production of the enzyme started from mid-exponential phase of bacterial growth and reached a maximum level during the post-stationary phase. The cellulase was purified to homogeneity with molecular mass of 45 kDa. Substrate specificity test indicated that it was an endoglucanase for soluble cellulose. Optimal enzyme activity was found to be at 60 °C, pH 8.0, and 7.5 % NaCl. Furthermore, it was highly active and stable over broad ranges of temperature (30–80 °C), pH (7.0–9.0), and NaCl concentration (2.5–15 %), thus showing its excellent thermostable, alkali-stable, and halotolerant nature. The cellulase activity was greatly inhibited by ethylenediaminetetraacetic acid, indicating that it was a metalloenzyme. Significant inhibition by phenylmethylsulfonyl fluoride and phenylarsine oxide revealed that serine and cysteine residues were essential for the enzyme catalysis. Moreover, the cellulase was highly active in the presence of surfactants, and it showed high stability in the presence of water-insoluble organic solvents with log P owat least 0.88. Results from this study indicate that the purified cellulase from isolate L1 may have considerable potential for industrial application owing to its useful properties.
Characterization of Water/Sucrose Laurate/n‐Propanol/Allylbenzene Microemulsions
Authors: Fanun Monzer , Ayad Ziad , Mudalal Samer , Dahoah Shirel , Meltzer Diana , Schwarze Michael , Schomäcker Reinhard , Blum Jochanan 
Published: March 2012

AbstractWater/n‐propanol/sucrose laurate/allylbenzene micellar systems were formulated and applied in the isomerization of allylbenzene in the presence of heterogenized derivatives of some platinum group catalysts. The ratio (w/w) of n‐propanol/surfactant studied herewith was 2/1. Temperature insensitive microemulsions were found. The microemulsions were characterized by the volumetric parameters, density, excess volume, ultrasonic velocity, and isentropic compressibility. The densities increase with increases in the water volume fraction. Excess volumes of the microemulsions decrease for water volume fractions below 0.2, level off for water volume fractions between 0.2 and 0.6 then increase for water volume fractions above 0.6. Excess volumes of the studied micellar systems increase with temperature. Isentropic compressibilities increase with temperature for water volume fractions below 0.8 and decrease for water volume fractions above 0.8. Structural transitions from water‐in‐oil to bicontinuous to oil‐in‐water occur along the microemulsion phase. The particle hydrodynamic diameter of the oil‐in‐water microemulsions at the 0.95 water volume fraction was found to decrease with temperature.
DROUGHT TOLERANCE IN CHICKPEA AS EVALUATED BY ROOT CHARACTERISTICS, PLANT WATER STATUS, MEMBRANE INTEGRITY AND CHLOROPHYLL FLUORESCENCE TECHNIQUES
Authors: KUMAR NEERAJ , NANDWAL A. S. , WALDIA R. S. , SINGH S. , DEVI S. , SHARMA K. D. , KUMAR A. 
Published: March 2012

SUMMARYRoot traits, such as depth and root biomass, have been identified as the most promising plant traits in chickpea for terminal drought tolerance. With this objective, five contrasting genotypes of chickpea, viz. ICCV-4958, H-208, HC-5, RSG-931 and CSJ-379, having wide adaptability to drought prone areas at national level were assessed for various root characteristics under two environments, i.e. irrigated and rain-fed. The sampling was done at full bloom stage and there were significant differences in the rooting depth among the genotypes both under irrigated and rain-fed conditions. The chickpea roots penetrated to a minimum depth of 92 cm in CSJ-379 and maximum of 122 cm in ICCV-4958 under rain-fed conditions. The rooting depth remained higher under rain-fed than irrigated environment. Under irrigated conditions, the chickpea roots were able to grow to a maximum depth of 99 and 97 cm in HC-5 and ICCV-4958, respectively. Among the genotypes, biomass per plant of the root was higher in ICCV-4958 (6.7 g) and HC-5 (5.6 g) under rain-fed conditions. Similar observations were recorded for root/shoot ratio, dry weights of stem, leaf, nodules and total dry weight per plant. The moisture stress increased the biomass partitioning towards the roots. The water potential (ψw), osmotic potential (ψs) and relative water content (RWC %) of leaf were –0.98 MPa, –1.82 MPa and 60%, respectively, in the genotype HC-5, and –1.02 MPa, –1.72 MPa and 64%, respectively, in ICCV-4958 under rain-fed conditions. The rates of photosynthesis, and transpiration, values of the stomatal conductance and photochemical efficiency/quantum yield as indicated by Fv/Fm ratio were in the range of 6.7 to 10.6 (μmol m−2 s−1), 1.27 to 2.38 (mmol m−2 s−1), 0.23 to 0.48 (mol m−2 s−1) and 0.457 to 0.584, respectively, under rain-fed conditions. Genotypes HC-5 and ICCV-4958 also maintained higher photosynthetic and transpiration rates and Fv/Fm ratio than others. The maximum Fv/Fm values in these genotypes were correlated with the higher photosynthetic rate and dry matter yield per plant. Relative stress injury (RSI %) values in HC-5 and ICCV-4958 noticed were 25.3% and 23.7%, respectively. The results of this study indicate that under rain-fed conditions, genotypes ICCV-4958 and HC-5 had higher dry weight of stem, leaves, roots, nodules and total dry weight per plant, rooting depth, root/shoot ratio, photosynthetic and transpiration rates, photochemical efficiency and better plant water status but lower stomatal conductance than other genotypes. These traits are directly associated with maximum seed yield per plant, i.e. 15.6 g and 14.7 g per plant, respectively, in these genotypes. Therefore, both the genotypes in future can be used in crop improvement programme of chickpea breeding for drought tolerance.
Short-form versions of the Spanish MacArthur–Bates Communicative Development Inventories
Authors: JACKSON-MALDONADO DONNA , MARCHMAN VIRGINIA A. , FERNALD LIA C. H. 
Published: March 2012

ABSTRACTThe Spanish-language MacArthur–Bates Communicative Development Inventories (S-CDIs) are well-established parent report tools for assessing the language development of Spanish-speaking children under 3 years. Here, we introduce the short-form versions of the S-CDIs (SFI and SFII), offered as alternatives to the long forms for screening purposes or in applications requiring a less-demanding instrument. Norming data (SFI: n = 601; SFII: n = 2,534) from diverse populations in Mexico are described. Developmental trends, gender differences, and socioeconomic status effects are reported that parallel those for the long forms. An additional small-scale study (n = 62) demonstrates strong convergence between responses on the long and the short forms. These results provide evidence that the S-CDI SFs have promise for a range of clinical and research applications.
Changes in adult children's participation in parent care
Authors: SZINOVACZ MAXIMILIANE E. , DAVEY ADAM 
Published: March 2012

ABSTRACTCare-giving research has focused on primary care-givers and relied on cross-sectional data. This approach neglects the dynamic and systemic character of care-giver networks. Our analyses address changes in care-givers and care networks over a two-year period using pooled data from the US Health and Retirement Study, 1992–2000. Based on a matrix of specific adult-child care-givers across two consecutive time-points, we assess changes in any adult-child care-giver and examine the predictors of change. A change in care-giver occurred in about two-fifths of care-giving networks. Ability to provide care based on geographical proximity, availability of alternative care-givers, and gender play primary roles in the stability of care networks. Results underline the need to shift care-giving research toward a dynamic and systemic perspective.
Bee (Apis mellifera) Venom Produced Toxic Effects of Higher Amplitude in Rat Thoracic Aorta than in Skeletal Muscle—An Ultrastructural Study
Authors: Florea Adrian , Crăciun Constantin 
Published: March 2012

AbstractIn this study, changes produced in aorta and triceps surae muscle of Wistar rats as response to bee venom (BV) envenomation were analyzed by transmission electron microscopy and morphometry. A subchronic treatment of 30 days with daily doses of 700 μg BV/kg and an acute-lethal treatment with a single dose of 62 mg BV/kg were performed. The subchronic treatment resulted in endothelial cell retraction, a thicker subendothelial layer, and thinner elastic laminae and musculoelastic layers in aorta, and thicker endothelium and basal laminae in skeletal muscle. In both tissues polymorphous, swollen mitochondria with disrupted cristae were observed. The acute treatment produced extensive endothelial lesions, breakdown of the collagen layer and migration of muscle cells toward the intima in the aorta, and dilatation of endoplasmic reticulum in the skeletal muscle cells. Mitochondria were almost devoid of cristae or with few circular cristae in the smooth muscle cells while most of the mitochondria presented abnormal circular cristae in the skeletal muscle cells. Degenerative alterations in the aorta were of higher intensity in our experiments—both the intima and media strongly responded to BV, in contrast to those found at the level of the skeletal muscle cells where a moderate degenerative myopathy was recorded.
Planetary period oscillations in Saturn's magnetosphere: Evolution of magnetic oscillation properties from southern summer to post‐equinox
Authors: Andrews D. J. , Cowley S. W. H. , Dougherty M. K. , Lamy L. , Provan G. , Southwood D. J. 
Published: March 2012

We investigate the evolution of the properties of planetary period magnetic field oscillations observed by the Cassini spacecraft in Saturn's magnetosphere over the interval from late 2004 to early 2011, spanning equinox in mid‐2009. Oscillations within the inner quasi‐dipolar region (L ≤ 12) consist of two components of close but distinct periods, corresponding essentially to the periods of the northern and southern Saturn kilometric radiation (SKR) modulations. These give rise to modulations of the combined amplitude and phase at the beat period of the two oscillations, from which the individual oscillation amplitudes and phases (and hence periods) can be determined. Phases are also determined from northern and southern polar oscillation data when available. Results indicate that the southern‐period amplitude declines modestly over this interval, while the northern‐period amplitude approximately doubles to become comparable with the southern‐period oscillations during the equinox interval, producing clear effects in pass‐to‐pass oscillation properties. It is also shown that the periods of the two oscillations strongly converge over the equinox interval, such that the beat period increases significantly from ∼20 to more than 100 days, but that they do not coalesce or cross during the interval investigated, contrary to recent reports of the behavior of the SKR periods. Examination of polar oscillation data for similar beat phase effects yields a null result within a ∼10% upper limit on the relative amplitude of northern‐period oscillations in the south and vice versa. This result strongly suggests a polar origin for the two oscillation periods.
Nitrous acid at Concordia (inland site) and Dumont d'Urville (coastal site), East Antarctica
Authors: Kerbrat Michael , Legrand Michel , Preunkert Susanne , Gallée Hubert , Kleffmann Jörg 
Published: March 2012

During the austral summer 2010/2011, nitrous acid (HONO) was investigated for the first time at Concordia (75°06′S, 123°33′E) and Dumont D'Urville (66°40′S, 140°01′E), two sites located in East Antarctica. Hereby, for the first time in Antarctica, HONO was measured by deploying a long path absorption photometer (LOPAP). At Concordia, HONO mixing ratios at 1 m above the snow surface ranged between 5 and 60 pptv from end of December 2010 to mid January 2011. Lowest levels were observed under cloudy conditions. Levels exhibit a diurnal cycle with a maximum in the morning (around 06:00) and in the evening (around 21:00). At Dumont d'Urville, background mixing ratios remained close to 2 pptv in February 2011. No clear diurnal cycles were detected at that site but several events of air masses export from inland Antarctica were encountered with enhanced HONO levels (10 pptv) at night. These first HONO data gained in East Antarctica are discussed in terms of sources and sinks along with synoptic weather conditions.
Flow topology and scalar mixing in spatially heterogeneous flow fields
Authors: de Barros Felipe P. J. , Dentz Marco , Koch Jonas , Nowak Wolfgang 
Published: March 2012

Scalar mixing plays a significant role for transport in geophysical flows because it controls dilution and is a main driver for many chemical reactions. Here we study the local scale flow mechanisms that lead to enhanced scalar mixing, and how they impact on the global mixing behavior. Mixing is quantified in terms of the entropy of the scalar distribution. It is shown that the evolution of entropy is directly linked to the flow topology in terms of the Okubo‐Weiss parameter Θ. Dominant shear and stretching deformation (Θ > 0) leads to a strong increase of local mixing strength, while dominant vorticity (Θ < 0) has only a minor impact. This allows to delineate regions of increased scalar mixing potential by mapping out the spatial distribution of Θ(x), and to relate global scalar mixing to an areal averaged effective Okubo‐Weiss measure.
Recombination modulates how selection affects linked sites in Drosophila
Authors: McGaugh Suzanne , Smukowski Caiti , Manzano-Winkler Brenda , Himmel Tiffany , Noor Mohamed 
Published: March 2012

AbstractOne of the most influential observations in molecular evolution has been a strong association between regional recombination rate and amount of nucleotide polymorphism in those genomic regions, interpreted as evidence for ubiquitous natural selection. The alternative explanation, that recombination is mutagenic, has been rejected by the absence of a similar association between regional recombination rate and nucleotide divergence between species. However, many recent studies show that recombination rates are often very different even in closely related species, questioning whether an association between recombination rate and divergence between species has been tested satisfactorily. To circumvent this problem, we directly surveyed recombination across approximately 43% of the D. pseudoobscura physical genome in two separate recombination maps, and 31.3% of the D. miranda physical genome, and we identified both global and local differences in recombination rate between these two closely related species. Using only regions with conserved recombination rates between and within species and accounting for multiple covariates, our data support the conclusion that recombination is positively related to diversity because recombination modulates hitchhiking in the genome. Finally, our data show that diversity around nonsynonymous substitutions is recovered at closer distances in areas of higher recombination than in areas of lower recombination — empirically demonstrating that recombination rate can limit the size and severity of potential selective sweeps.
JETTA: junction and exon toolkits for transcriptome analysis
Authors: Seok Junhee , Xu Weihong , Gao Hong , Davis Ronald W. , Xiao Wenzhong 
Published: March 2012

Abstract
Summary: High-throughput genome-wide studies of alternatively spliced mRNA transcripts have become increasingly important in clinical research. Consequently, easy-to-use software tools are required to process data from these studies, for example, using exon and junction arrays. Here, we introduce JETTA, an integrated software package for the calculation of gene expression indices as well as the identification and visualization of alternative splicing events. We demonstrate the software using data of human liver and muscle samples hybridized on an exon–junction array.
Availability: JETTA and its demonstrations are freely available at http://igenomed.stanford.edu/~junhee/JETTA/index.html
Contacts: wxiao1@partners.org
Changes in Barents Sea ecosystem state, 1970–2009: climate fluctuations, human impact, and trophic interactions
Authors: Johannesen Edda , Ingvaldsen Randi B. , Bogstad Bjarte , Dalpadado Padmini , Eriksen Elena , Gjøsæter Harald , Knutsen Tor , Skern-Mauritzen Mette , Stiansen Jan Erik 
Published: March 2012

Abstract
Johannesen, E., Ingvaldsen, R. B., Bogstad, B., Dalpadado, P., Eriksen, E., Gjøsæter, H., Knutsen, T., Skern-Mauritzen, M., and Stiansen, J. E. 2012. Changes in Barents Sea ecosystem state, 1970–2009: climate fluctuations, human impact, and trophic interactions. – ICES Journal of Marine Science, 69: 880–889. Long time-series of data from the Barents Sea (BS) are analysed to contrast the climate, fishing pressure, plankton, pelagic fish, demersal fish, and interactions between trophic levels in a recent decade (2000–2009) with the period 1970–1999. During the past four decades, fishing pressure and climatic conditions have varied greatly in the BS, and stock levels have fluctuated substantially. Trophic control has changed from mainly bottom–up to top–down, then back to mainly bottom–up. No clear evidence for persistent ecological regimes was found. The past decade has been the warmest on record, with large stocks of demersal and pelagic fish, and increasing abundances of krill and shrimp. Except perhaps for the rather less-studied Arctic species, the short-term effect of the recent warming has been positive for BS stocks. However, as many of the long-established relationships and mechanisms in the BS seem to be changing, the long-term effects of warming are uncertain.
Early Treatment with Risperidone for Subsyndromal Delirium after On-pump Cardiac Surgery in the Elderly
Authors: Hakim Sameh M. , Othman Ahmed I. , Naoum Dina O. 
Published: March 2012

Background
The aim of this randomized, parallel-arm trial was to study the effect of treating subsyndromal delirium with risperidone on the incidence of clinical delirium in elderly patients who underwent on-pump cardiac surgery.

Methods
One hundred one patients aged 65 yr or older who experienced subsyndromal delirium after on-pump cardiac surgery were randomized using a computer-generated list to receive 0.5 mg risperidone (n = 51) or placebo (n = 50) every 12 h by mouth. Patients were assessed at 8 h by a blinded observer using the Intensive Care Delirium Screening Checklist, and those scoring more than 3 were evaluated by a blinded psychiatrist to confirm delirium. Patients in either group who experienced delirium were treated according to the same algorithm. Initially, risperidone was administered and if symptoms were not controlled, haloperidol was administered. The primary outcome was the proportion of patients who experienced delirium in either group.

Results
Seven (13.7%) patients in the risperidone group experienced delirium versus 17 (34%) in the placebo group (P = 0.031) Competing-risks regression analysis showed that failure to treat subsyndromal delirium with risperidone was an independent risk factor for delirium (subhazard ratio, 3.83; 95% CI, 1.63-8.98; P = 0.002). Two (3.9%) patients in the risperidone group experienced extrapyramidal manifestations versus one (2%) in the placebo group (P = 1.0).

Conclusion
Administration of risperidone to elderly patients who experienced subsyndromal delirium after on-pump cardiac surgery was associated with significantly lower incidence of delirium. Larger studies are required to determine whether early administration of risperidone during the subsyndromal phase of delirium would influence the clinical course of such patients.