bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic/inorganic support for immobilizing (n‐BuCp)2ZrCl2/TiCl3 hybrid catalyst for use in the preparation of polymer blends
Authors: Li Wei , Jiang Binbo , Wang Jingdai , Yang Yongrong 
Published: December 2010

AbstractReactor blends of ultrahigh‐molecular‐weight polyethylene (UHMWPE) and low‐molecular‐weight polyethylene (LMWPE) were synthesized by two‐step polymerization using a hybrid catalyst. To prepare the hybrid catalyst, styrene acrylic copolymer (PSA) was first coated onto SiO2/MgCl2‐supported TiCl3; then, (n‐BuCp)2ZrCl2 was immobilized onto the exterior PSA. UHMWPE was produced in the first polymerization stage with the presence of 1‐hexene and modified methylaluminoxane (MMAO), and the LMWPE was prepared with the presence of hydrogen and triethylaluminium in the second polymerization stage. The activity of the hybrid catalyst was considerable (6.5 × 106 g PE (mol Zr)−1 h−1), and was maintained for longer than 8 h during the two‐step polymerization. The barrier property of PSA to the co‐catalyst was verified using ethylene polymerization experiments. The appearance of a lag phase in the kinetic curve during the first‐stage polymerization implied that the exterior catalyst ((n‐BuCp)2ZrCl2) could be activated prior to the interior catalyst (M‐1). Furthermore, the melting temperature, crystallinity, degree of branching, molecular weight and molecular‐weight distribution of polyethylene obtained at various polymerization times showed that the M‐1 catalyst began to be activated by MMAO after 40 min of the reaction. The activation of M‐1 catalyst led to a decrease in the molecular weight of UHMWPE. Finally, the thermal behaviors of polyethylene blends were investigated using differential scanning calorimetry. Copyright © 2011 Society of Chemical Industry
Synthesis of octahedral zirconium complex bearing [NHCO] ligands, and its behavior as catalyst in the polymerization of olefins
Authors: Bocchino Carmen , Napoli Mariagrazia , Costabile Chiara , Longo Pasquale 
Published: December 2010

AbstractThe synthesis and characterization of a zirconium complex, having two alkoxide functionalized N‐heterocyclic carbene ligands, and its behavior as catalyst in the polymerization of ethylene and propylene, have been reported. NMR analysis showed that more than one species was obtained during synthesis. These data were confirmed by ethylene polymerization that gave rise to a linear polyethylene having a high Molecular weight and a polydispersity index (MDI) > 2 and often bimodal. The same catalytic system was able to produce highly isotactic polypropylene together with an atactic fraction. DFT studies on the complex stereoisomer stability gave indications on the species possibly involved in the polymerizations. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Insecticide resistance of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in mainland China
Authors: Jin Tao , Zeng Ling , Lin Yuying , Lu Yongyue , Liang Guangwen 
Published: December 2010

AbstractBACKGROUND: In order to investigate the extent of resistance of oriental fruit fly, Bactrocera dorsalis (Hendel), which is a widespread pest throughout tropical, subtropical and temperate fruit crops, 25 populations of this insect were collected from 13 sites in mainland China in 2007 and 2008. In addition, resistant strains were established that showed increasing development of resistance.RESULTS: Compared with the susceptible strain, one population of B. dorsalis expressed high resistance (RR = 70.4‐fold), 16 populations expressed medium resistance (11.5‐fold < RR < 25.8‐fold) and eight populations had low resistance or remained susceptible (1.4‐fold < RR < 8.9‐fold) to trichlorphon. As regards β‐cypermethrin, one population showed high resistance (RR = 44.0‐fold), nine populations expressed medium resistance (12.2‐fold < RR < 28.4‐fold), 14 populations expressed low or minor resistance (3.0‐fold < RR < 9.7‐fold) and one population remained susceptible (RR = 1.1‐fold). As regards avermectin, five populations had developed high resistance (44.3‐fold < RR < 104‐fold), seven populations expressed medium resistance (11.4‐fold < RR < 38.6‐fold) and three populations expressed low or minor resistance (3.5‐fold < RR < 5.6‐fold). A continuous resistance selection in the laboratory strain showed that the resistance ratios to trichlorphon, β‐cypermethrin and avermectin were 71.6‐fold, 333‐fold and 70.4‐fold respectively.CONCLUSION: The data provided a comprehensive survey of insecticide resistance in Bactrocera dorsalis in mainland China. All results suggested that early resistance management programmes should be established for restoring the efficacy of pesticide‐based control measures. Copyright © 2010 Society of Chemical Industry
Structural characterization of crystallized Si thin film material by HRTEM and Raman spectroscopy
Authors: Mchedlidze Teimuraz , Beigmohamadi Maryam , Berghoff Birger , Sohal Rakesh , Suckow Stephan , Arguirov Tzanimir , Wilck Noël , Mayer Joachim , Spangenberg Bernd , Kittler Martin 
Published: December 2010

AbstractComparative structural analyses of a crystallized, 60 nm thick silicon film deposited on quartz substrate were performed using high resolution transmission electron microscopy (HRTEM) and Raman spectroscopy (RS). Both methods suggest high degree of crystallization of the film. The material of the film consists of crystalline grains with sizes up to 20 nm (HRTEM) and the mean size of the grains is ∼4 nm (RS). HRTEM results suggest large scatter of the crystal orientations of the grains. The existence of boundary defects between grains grouped in large agglomerates was also detected by HRTEM. RS analyses indicate large compressive strain in the system and the existence of high pressure Si phases in the material of the film.
Epitaxy‐free monocrystalline silicon thin films: Identifying the mechanisms behind lifetime degradation upon multiple high‐temperature annealings
Authors: Depauw Valérie , Simoen Eddy , Gordon Ivan , Poortmans Jef 
Published: December 2010

AbstractThis work initiates an investigation of the impact of high‐temperature annealings on the material quality of reusable substrates for an “Epifree” solar‐cell process, where the substrate itself provides the active layer of the cell. The minority‐carrier lifetime of simple bulk wafers is monitored by photoconductance decay and the mechanisms affecting it are explored by deep‐level transient spectroscopy. The lifetime is found to drop from the first annealing and then to stabilize to values sufficient for solar‐cell application, at a minimum of 10 µs. The amplitude of this drop is strongly related to the wafer type (MCz or Cz) and no major recombination center could be identified as possible cause.
Universal cervical‐length screening to prevent preterm birth: a cost‐effectiveness analysis
Authors: Werner E. F. , Han C. S. , Pettker C. M. , Buhimschi C. S. , Copel J. A. , Funai E. F. , Thung S. F. 
Published: December 2010

AbstractObjectiveTo determine whether routine measurement of second‐trimester transvaginal cervical length by ultrasound in low‐risk singleton pregnancies is a cost‐effective strategy.MethodsWe developed a decision analysis model to compare the cost‐effectiveness of two strategies for identifying pregnancies at risk for preterm birth: (1) no routine cervical length screening and (2) a single routine transvaginal cervical length measurement at 18–24 weeks' gestation. In our model, women identified as being at increased risk (cervical length < 1.5 cm) for preterm birth would be offered daily vaginal progesterone supplementation. We assumed that vaginal progesterone reduces preterm birth at < 34 weeks' gestation by 45%. We also assumed that a decreased cervical length could result in additional costs (ultrasound scans, inpatient admission) without significantly improved neonatal outcomes. The main outcome measure was incremental cost‐effectiveness ratio.ResultsOur model predicts that routine cervical‐length screening is a dominant strategy when compared to routine care. For every 100 000 women screened, $ 12 119 947 can be potentially saved (in 2010 US dollars) and 423.9 quality‐adjusted life‐years could be gained. Additionally, we estimate that 22 cases of neonatal death or long‐term neurologic deficits could be prevented per 100 000 women screened. Screening remained cost‐effective but was no longer the dominant strategy when cervical‐length ultrasound measurement costs exceeded $ 187 or when vaginal progesterone reduced delivery risk at < 34 weeks by less than 20%.ConclusionIn low‐risk pregnancies, universal transvaginal cervical length ultrasound screening appears to be a cost‐effective strategy under a wide range of clinical circumstances (varied preterm birth rates, predictive values of a shortened cervix and costs). Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Meteorological wind energy potential in the Alps using ERA40 and wind measurement sites in the Tyrolean Alps
Authors: Draxl Caroline , Mayr Georg J. 
Published: December 2010

AbstractThe peculiarities of meteorological wind potential in alpine settings compared to flatland and offshore sites are studied. Four data sources are used: Global reanalysis ERA40 from ECMWF, long‐term stations in the Tyrolean Alps, spatially dense measurements near the best site and Doppler sodar wind profiles. Due to the decrease of density with height, alpine sites suffer from a nearly linear decrease of harvestable power with altitude, which is more than offset by the increase of wind speed at altitudes above 1.5 km MSL. ERA40 data show higher potential on the northern than on the southern side of the Alps. The best locations are not isolated peaks but ridges within wide orographic channels. The best potential sites in the Tyrolean part of the Alps have median wind speeds of up to 7.1 m s−1 and extractable potentials between 2900 and 1600 kWh per year and per square meter of rotor area. The profile of horizontal wind speed at ridge sites is often not logarithmic but approximately constant within the height of a wind turbine due to a (nearly) complete absence of upwind fetch. Also, the turbulence intensity is independent of height. Icing can cause considerable downtimes. Copyright © 2010 John Wiley & Sons, Ltd.
Conflict in the Sea of Trafalgar: offshore wind energy and its context
Authors: Todt O. , González M. I. , Estévez B. 
Published: December 2010

AbstractThis paper analyses a participatory process related to the plan to construct an offshore wind farm in the Sea of Trafalgar, off the coast of Cádiz, in Andalucía (southern Spain). This case study shows the complexities of public participation in energy development, indicating the vital importance of context. The stakeholders' values and attitudes in the controversy are highly dependent on the specific situation, including the concrete characteristics of the project proposal. In fact, they may diverge sharply from the stakeholders' core beliefs. It is important for decision making to take account of this contextual and dynamic element in stakeholder behavior, contrary to suppositions of static and predetermined behavior. Copyright © 2010 John Wiley & Sons, Ltd.
Stress symptoms among adolescents: The role of subjective psychosocial conditions, lifestyle, and self‐esteem
Authors: Schraml Karin , Perski Aleksander , Grossi Giorgio , Simonsson‐Sarnecki Margareta 
Published: December 2010

ABSTRACTStress‐related problems are increasing among Swedish adolescents, especially among females. The aims of this study were to survey the incidence of stress symptoms among 16‐year‐olds, to investigate the related gender differences, and to understand the factors that may contribute to stress symptoms. The study is questionnaire based, and the sample included 304 first‐year high school students from two comparable schools. More than 30% of the high school students reported serious stress symptoms. Almost every second girl and every fifth boy reported that they felt stressed to a high degree. 8.2% were found to have severe stress symptoms, which would be considered a sign of chronic stress in adults. Besides the perception of high demands, low levels of global self‐esteem, sleep disturbances, and poor social support played a crucial role in the prediction of stress symptoms. The findings highlight the need to develop and implement adequate stress prevention measures for adolescents.
Why falling information costs may increase demand for index funds
Authors: Sirnes Espen 
Published: December 2010

AbstractFalling information costs may give the perverse incentive to buy less information in equilibrium. Using a model similar to Admati and Pfleiderer (1988) but with a market that clears via an equilibrium condition, it is shown that passive investment may actually rise with lower information costs. This is consistent with the empirical observation that index investing has increased along with a decline in information costs. Also, in absence of such costs, no investor will hold index portfolios if at least some uninformed investors can condition on current prices. The existence of passive index investors may therefore be inconsistent with unrestricted observation of current prices.
Estimating the correlation of non-allele descents along chromosomes
Authors: HU XIN-SHENG , WANG ZHIQUAN 
Published: December 2010

SummaryThe pattern of the correlation of non-allele descents among linked sites is an important aspect for an insight into the genomic evolution at the population level. Here, we present a new statistical method for estimating two types of non-allele descent correlations. One is the standardized parental descent disequilibrium termed by Cockerham & Weir (1973), the other is the standardized disequilibrium between non-allele descent segments from the same chromosome. Essential to this analysis is the partitioning of the joint identity-by-state probability for a random pair of non-allele gametes into the different components of identity by descents at the two or three sites. We consider the samples of phased haplotypes of single nucleotide polymorphism (SNP) markers and the weighted least square method for fast parameter estimation. Monte Carlo simulations demonstrate that robustly unbiased estimates with appropriate precisions can be obtained with certain sample sizes, ~100 diploids, under the impacts of allele frequency distributions and linkage disequilibrium. This method can be used to construct the maps of non-allele descent correlation blocks for the population whose genetic pedigree is not required on a prior basis.
Improved Lasso for genomic selection
Authors: LEGARRA ANDRÉS , ROBERT-GRANIÉ CHRISTÈLE , CROISEAU PASCAL , GUILLAUME FRANÇOIS , FRITZ SÉBASTIEN 
Published: December 2010

SummaryEmpirical experience with genomic selection in dairy cattle suggests that the distribution of the effects of single nucleotide polymorphisms (SNPs) might be far from normality for some traits. An alternative, avoiding the use of arbitrary prior information, is the Bayesian Lasso (BL). Regular BL uses a common variance parameter for residual and SNP effects (BL1Var). We propose here a BL with different residual and SNP effect variances (BL2Var), equivalent to the original Lasso formulation. The λ parameter in Lasso is related to genetic variation in the population. We also suggest precomputing individual variances of SNP effects by BL2Var, to be later used in a linear mixed model (HetVar-GBLUP). Models were tested in a cross-validation design including 1756 Holstein and 678 Montbéliarde French bulls, with 1216 and 451 bulls used as training data; 51 325 and 49 625 polymorphic SNP were used. Milk production traits were tested. Other methods tested included linear mixed models using variances inferred from pedigree estimates or integrated out from the data. Estimates of genetic variation in the population were close to pedigree estimates in BL2Var but not in BL1Var. BL1Var shrank breeding values too little because of the common variance. BL2Var was the most accurate method for prediction and accommodated well major genes, in particular for fat percentage. BL1Var was the least accurate. HetVar-GBLUP was almost as accurate as BL2Var and allows for simple computations and extensions.
A 1,200-year perspective of 21st century drought in southwestern North America
Authors: Woodhouse Connie A. , Meko David M. , MacDonald Glen M. , Stahle Dave W. , Cook Edward R. 
Published: December 2010

A key feature of anticipated 21st century droughts in Southwest North America is the concurrence of elevated temperatures and increased aridity. Instrumental records and paleoclimatic evidence for past prolonged drought in the Southwest that coincide with elevated temperatures can be assessed to provide insights on temperature-drought relations and to develop worst-case scenarios for the future. In particular, during the medieval period, ∼AD 900–1300, the Northern Hemisphere experienced temperatures warmer than all but the most recent decades. Paleoclimatic and model data indicate increased temperatures in western North America of approximately 1 °C over the long-term mean. This was a period of extensive and persistent aridity over western North America. Paleoclimatic evidence suggests drought in the mid-12th century far exceeded the severity, duration, and extent of subsequent droughts. The driest decade of this drought was anomalously warm, though not as warm as the late 20th and early 21st centuries. The convergence of prolonged warming and arid conditions suggests the mid-12th century may serve as a conservative analogue for severe droughts that might occur in the future. The severity, extent, and persistence of the 12th century drought that occurred under natural climate variability, have important implications for water resource management. The causes of past and future drought will not be identical but warm droughts, inferred from paleoclimatic records, demonstrate the plausibility of extensive, severe droughts, provide a long-term perspective on the ongoing drought conditions in the Southwest, and suggest the need for regional sustainability planning for the future.
There’s plenty of time for evolution
Authors: Wilf Herbert S. , Ewens Warren J. 
Published: December 2010

Objections to Darwinian evolution are often based on the time required to carry out the necessary mutations. Seemingly, exponential numbers of mutations are needed. We show that such estimates ignore the effects of natural selection, and that the numbers of necessary mutations are thereby reduced to about
K
log
L
, rather than
K

L

, where
L
is the length of the genomic “word,” and
K
is the number of possible “letters” that can occupy any position in the word. The required theory makes contact with the theory of radix-exchange sorting in theoretical computer science, and the asymptotic analysis of certain sums that occur there.
Proteomic analysis of myocardial tissue from the border zone during early stage post‐infarct remodelling in rats
Authors: Xiang Fei , Shi Zhonghua , Guo Xuejiang , Qiu Zhibing , Chen Xujun , Huang Fuhua , Sha Jiahao , Chen Xin 
Published: December 2010

AimsLong‐term outcome of patients after myocardial infarction (MI) largely depends on the extent of post‐infarct remodelling. To explore the molecular mechanism of remodelling, comparative proteomic analysis was undertaken to identify differential myocardial proteome profiles expressed in the border zone of the post‐MI heart.Methods and resultsTwo‐dimensional gel electrophoresis and matrix‐assisted laser desorption/ionization tandem time‐of‐flight mass spectrometry were used to identify the differential protein profiles expressed in the border zone at specific time points (Days 0, 1, 4, and 10 post‐infarction) in a permanent rat MI model. We identified 96 differential protein spots, corresponding to 69 proteins. Cluster analysis exhibited five main temporal expression patterns corresponding to the three phases of early stage remodelling. The alteration in expression was supported by reverse transcription‐polymerase chain reaction, western blotting, and immunohistochemical analysis of three selected proteins. Bioinformatics analysis revealed that the proteins in each pattern were functionally related to specific cell processes in remodelling, such as ischaemia, inflammation, and proliferation.ConclusionA differential myocardial proteome profile was identified in the border zone during early stage post‐infarct remodelling. Bioinformatics analysis indicated a possible role of these proteins in remodelling. Proteomics data provided the basis for further functional study of these proteins and for identifying potential molecular targets with therapeutic anti‐remodelling effects.
Trophic ecology of elasmobranchs caught off Gujarat, India, as inferred from stable isotopes
Authors: Borrell Asunción , Cardona Luis , Kumarran Ramanathan P. , Aguilar Alejandro 
Published: December 2010

AbstractBorrell, A., Cardona, L., Kumarran, R. P., and Aguilar, A. 2011. Trophic ecology of elasmobranchs caught off Gujarat, India, as inferred from stable isotopes. – ICES Journal of Marine Science, 68: . Habitat use and trophic levels were investigated in 13 species of elasmobranch caught off Gujarat, India, through their isotopic composition. Most of the animals were fished commercially and were immature, suggesting that fisheries operate in nursery habitats. All of the sharks analysed except Rhincodon typus had a higher estimated trophic level (>3.8) than rays and guitarfish (<3.8), suggesting a diet of bony fish and cephalopods. The trophic level of Sphyrna lewini and R. typus increased with total length, indicating ontogenetic dietary shifts, but the other species did not follow this trend. According to their δ13C values, R. typus, Mobula diabolus, and, surprisingly, Rhina ancylostoma appeared to be the most pelagic species. In comparison, Stegostoma fasciatum, Pristis pectinata, Rhinobatos granulatus, and Aetomylaeus maculatus appeared to be the most demersal, inshore species, and their δ13C signatures were significantly different from those of the three aforementioned species.