bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of methods and basis set on ab initio calculations of electronic transport through hydrogenated Pt nanocontacts
Authors: García Y. , San‐fabián E. , Louis E. , Vergés J. A. 
Published: March 2008

AbstractThe effects of varying methods and basis set on ab initio calculations of electronic transport through hydrogenated Pt nanocontacts have been investigated. The nanocontact atomic arrangement was simulated by means of two pyramids facing each other along the (001) direction, and containing either 5 or 14 atoms each. A hydrogen molecule was placed between the two pyramid apexes, transversal to the nanocontact axis. The reliability of various methods‐basis set combinations has been checked by comparing with experimental data for the equilibrium distance and the vibrational frequency of PtH molecule. The study was carried out using a large set of methods includingthe most classic in the field of Quantum Chemistry (HF), density functional methods (HFLYP, BLYP, PW91PW91, TPSS) as well as hybrids (B3LYP). The most important outcome of this work is a call of attention to those using Quantum Chemistry methods to calculate the conductance through nanosystems, remarking on the need of an appropriate choice of the tools being used in a particular case. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Binary encounter model for the electron impact K‐shell ionization of atoms
Authors: Patoary M. A. R. , Uddin M. Alfaz , Haque A. K. F. , Shahjahan M. , Basak A. K. , Saha B. C. 
Published: March 2008

AbstractThe electron impact K‐shell ionization (EIKSI) cross sections on 18 atomic targets, with the atomic numbers 2 ≤ Z ≤ 92, are calculated using a modified version of the binary encounter approximation (BEA) model. The modified BEA (MBEA), which incorporates both ionic and relativistic corrections and is simpler in application than other existing models, is found to be immensely successful in describing the EIKSI data up to the incident energy of 1 GeV. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Quantum mechanical model for Maya Blue
Authors: Fuentes María E. , Peña Brisa , Contreras César , Montero Ana L. , Chianelli Russell , Alvarado Manuel , Olivas Ramón , Rodríguez Luz M. , Camacho Héctor , Montero‐Cabrera Luis A. 
Published: March 2008

AbstractThis work is about Maya Blue (MB), a pigment developed by Mesoamerican civilizations between the 5th and 16th centuries from an aluminosilicate mineral (palygorskite) and an organic dye (indigo). Two different supramolecular quantum‐mechanical models afford explanations for the unusual stability of MB based on the oxidation of the indigo molecule during the heating process and its interaction with palygorskite. A model considering indigo derivatives attached to several aluminates shows the principal features of the experimental visible spectrum of MB within the TD‐DFT methodology. Another model of an indigo oxidized species confined within an inorganic supramolecular cavity system, that involves about 170 atoms, was calculated after a large configuration interaction of single excited determinants within the NDOL approximation (Montero‐Cabrera et al., J Chem Phys, 2007, 127, 145102). It allows a correct reproduction and interpretation of the corresponding spectrum. This second methodology provides the most satisfactory results, being able to manage very big molecular systems at a QM level. Structural explanation for the unusual stability of MB is also provided. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
2D and 3D‐QSAR studies on antiproliferative thiazolidine analogs
Authors: Liao Si Yan , Qian Li , Chen Jin Can , Lu Hai Liang , Zheng Kang Cheng 
Published: March 2008

AbstractTwo‐dimensional (2D) and three‐dimensional (3D) quantitative structure–activity relationships (QSARs) of 22 thiazolidine analogs with antiproliferative activity expressed as pIC50, which is defined as the negative value of the logarithm of necessary molar concentration of these compounds to cause 50% growth inhibition against melanoma cell lines WM‐164, have been studied by using a combined method of the DFT, MM2 and statistics for 2D, as well as the comparative molecular field analysis (CoMFA) method for 3D. The established 2D‐QSAR model in training set comprised of random 18 compounds shows not only significant statistical quality, but also predictive ability, with the square of adjusted correlation coefficient (R = 0.832) and the square of the cross‐validation coefficient (q2 = 0.803). The same model was further applied to predict pIC50 values of the four compounds in the test set, and the resulting R reaching 0.784, further confirms that this 2D‐QSAR model has high predictive ability. The 3D‐QSAR model also shows good correlative and predictive capabilities in terms of R2 (0.956) and q2 (0.615) obtained from CoMFA model. Further, the robustness of the CoMFA model was verified by bootstrapping analysis (100 runs) with R (0.979) and SDbs (0.056). It is very interesting to find that the results from 2D‐ and 3D‐QSAR analyses accord with each other, and they all show that the steric interaction plays a crucial role in determining the cytotoxicities of the compounds, and that selecting a moderate‐size or appropriate‐hydrophobicity substituent R as well as increasing the negative charges of C4 on phenyl ring at the same time are advantageous to improving the cytotoxicity. Such results can offer some useful theoretical references for directing the molecular design and understanding the action mechanism of this kind of compound with antiproliferative activity. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Highly accurate differential deposition for X‐ray reflective optics
Authors: Handa Soichiro , Mimura Hidekazu , Yumoto Hirokatsu , Kimura Takashi , Matsuyama Satoshi , Sano Yasuhisa , Yamauchi Kazuto 
Published: March 2008

AbstractWe have developed a highly accurate differential deposition system for the fabrication of X‐ray optical devices. Using this system, thin films having a thickness distribution gradually changing along the longitudinal direction on a substrate surface could be produced with sub‐nanometer accuracy. The surface flatness of the deposited films was confirmed by atomic force microscopy observation, and the surface was sufficiently smooth to prevent X‐ray scattering on the mirror surface. A demonstration of differential deposition was performed and a Pt thin film having the desired thickness profile was successfully deposited on a 100 mm long substrate. Copyright © 2008 John Wiley & Sons, Ltd.
The structure of the water–propane interface investigated by x‐ray reflectivity measurements
Authors: Paulus Michael , Gutt Christian , Tolan Metin 
Published: March 2008

AbstractWe present an x‐ray reflectivity study of the water–propane interface. The vertical structure of the interface is analyzed and the adsorption of thin layers of propane on the water surface is observed. An increase of layer thickness with rising pressure is found. The electron density of the thin films is identical with the corresponding value of bulk liquid propane. From the adsorption isotherm we determine the Hamaker constant of the system, which shows a considerably higher value compared to calculations based on the Lifshitz theory. The surface tension of the molecularly thin layer is reduced in comparison to the bulk value. The measured surface roughness is in good agreement with a modified model based on capillary wave fluctuations of the water‐propane–gas interfaces. Copyright © 2008 John Wiley & Sons, Ltd.
Survival models for cost data: The forgotten additive approach
Authors: Pagano Eva , Petrinco Michele , Desideri Alessandro , Bigi Riccardo , Merletti Franco , Gregori Dario 
Published: March 2008

AbstractThe usage of the Aalen additive approach is proposed to model cost data. Using a Monte Carlo simulation, in a wide set of scenarios, we showed that the Aalen model is performing well and can be a reasonable alternative to the standard Gamma regression models. In addition, with reference to the COSTAMI trial data, we highlighted the ability of the Aalen model to offer additional information about the relationships between costs and specific covariates, as compared with standard regression techniques. Copyright © 2008 John Wiley & Sons, Ltd.
How conservative is Fisher's exact test? A quantitative evaluation of the two‐sample comparative binomial trial
Authors: Crans Gerald G. , Shuster Jonathan J. 
Published: March 2008

AbstractThe debate as to which statistical methodology is most appropriate for the analysis of the two‐sample comparative binomial trial has persisted for decades. Practitioners who favor the conditional methods of Fisher, Fisher's exact test (FET), claim that only experimental outcomes containing the same amount of information should be considered when performing analyses. Hence, the total number of successes should be fixed at its observed level in hypothetical repetitions of the experiment. Using conditional methods in clinical settings can pose interpretation difficulties, since results are derived using conditional sample spaces rather than the set of all possible outcomes. Perhaps more importantly from a clinical trial design perspective, this test can be too conservative, resulting in greater resource requirements and more subjects exposed to an experimental treatment. The actual significance level attained by FET (the size of the test) has not been reported in the statistical literature. Berger (J. R. Statist. Soc. D (The Statistician) 2001; 50:79–85) proposed assessing the conservativeness of conditional methods using p‐value confidence intervals. In this paper we develop a numerical algorithm that calculates the size of FET for sample sizes, n, up to 125 per group at the two‐sided significance level, α=0.05. Additionally, this numerical method is used to define new significance levels α*=α+ε, where ε is a small positive number, for each n, such that the size of the test is as close as possible to the pre‐specified α (0.05 for the current work) without exceeding it. Lastly, a sample size and power calculation example are presented, which demonstrates the statistical advantages of implementing the adjustment to FET (using α* instead of α) in the two‐sample comparative binomial trial. Copyright © 2008 John Wiley & Sons, Ltd.
Prevention of Anastomotic Stricture with a Purse‐string Suture Technique on the Gastric Side During Esophageal Carcinoma Operations: Retrospective Study of 463 Consecutive Cases
Authors: Zhang Chong , Yao Min‐hua , Jin Tao , Sun Li , Hu Jian , Zha Yu‐xin 
Published: March 2008

AbstractObjectiveThe objective of this study was to investigate the effect of a gastric side purse‐string technique on anastomotic strictures during esophageal carcinoma operations.MethodsFrom 1996 to 2005, esophageal carcinoma operations were performed on 1128 consecutive patients. Among them, 463 underwent esophagogastric anastomosis with purse‐string sutures on the gastric side (purse group) and the other 665 did not (nonpurse group). Anastomotic strictures, reflux, and leakage were analyzed and compared between the two groups after the operations.ResultsComplete follow‐up was conducted on all 1128 patients within 6 months after the operation. In contrast to the nonpurse group with a postoperative anastomotic stricture rate of 5.4% (36/665), the purse group demonstrated a significantly lower rate (0.2%, 1/463). The occurrence rates of anastomotic leakage in the nonpurse and purse groups were 0.9% (6/665) and 0.4% (2/463), respectively. Of the 17 cases of gastroesophageal reflux, 15 (15/665, 1.8%) were found in the nonpurse group and 2 (2/463, 1.1%) in the purse group.ConclusionsThus, a purse‐string suture technique on the gastric side might be an effective method for preventing the occurrence of anastomotic strictures after esophageal resection.
The consequences of extended newborn screening programmes: Do we know who needs treatment?
Authors: Wilcken B. 
Published: March 2008

SummaryThe development of an evidence base for newborn screening is especially difficult because of the rarity of disorders now detectable. One consequence of expanded newborn screening is that physicians are being called upon to manage asymptomatic babies with persistent biochemical disturbances that indicate likely enzyme deficiencies. Some of these may be very mild. There is not always agreement as to who should be treated. Particular problems are seen with disorders that were previously thought very rare but are now found frequently by newborn screening. Some of these disorders appear benign or nearly so, and in the present state of knowledge should clearly not be included in routine newborn screening panels.
Obsessive–Compulsive Disorder: Influence of Age at Onset on Comorbidity Patterns
Authors: de Mathis Maria Alice , do Rosario Maria Conceição , Diniz Juliana Belo , Torres Albina Rodrigues , Shavitt Roseli Gedanki , Ferrão Ygor Arzeno , Fossaluza Victor , de Bragança Pereira Carlos Alberto , Miguel Eurípedes Constantino 
Published: March 2008

AbstractPurpose.This study investigates the influence of age at onset of OCS on psychiatric comorbidities, and tries to establish a cut-off point for age at onset.Methods.Three hundred and thirty OCD patients were consecutively recruited and interviewed using the following structured interviews: Yale-Brown Obsessive Compulsive Scale; Yale Global Tic Severity Scale and the Structured Clinical Interview for DSM-IV. Data were analyzed with regression and cluster analysis.Results.Lower age at onset was associated with a higher probability of having comorbidity with tic, anxiety, somatoform, eating and impulse–control disorders. Longer illness duration was associated with lower chance of having tics. Female gender was associated with anxiety, eating and impulse–control disorders. Tic disorders were associated with anxiety disorders and attention-deficit/hyperactivity disorder. No cut-off age at onset was found to clearly divide the sample in homogeneous subgroups. However, cluster analyses revealed that differences started to emerge at the age of 10 and were more pronounced at the age of 17, suggesting that these were the best cut-off points on this sample.Conclusions.Age at onset is associated with specific comorbidity patterns in OCD patients. More prominent differences are obtained when analyzing age at onset as an absolute value.
LOCAL RADIAL BASIS FUNCTION APPROXIMATION ON THE SPHERE
Authors: HESSE KERSTIN , LE GIA Q. T. 
Published: March 2008

AbstractIn this paper we derive local error estimates for radial basis function interpolation on the unit sphere$\mathbb {S}^2\subset \mathbb {R}^3$. More precisely, we consider radial basis function interpolation based on data on a (global or local) point set$X\subset \mathbb {S}^2$for functions in the Sobolev space$H^s(\mathbb {S}^2)$with norm$\|\cdot \|_s$, wheres>1. The zonal positive definite continuous kernel ϕ, which defines the radial basis function, is chosen such that its native space can be identified with$H^s(\mathbb {S}^2)$. Under these assumptions we derive a local estimate for the uniform error on a spherical capS(z;r): the radial basis function interpolant ΛXfof$f\in H^s(\mathbb {S}^2)$satisfies$\sup _{\mathbf {x}\in S(\mathbf {z};r)} |f(\mathbf {x})-\Lambda _X f(\mathbf {x})| \leq c h^{(s-1)/2} \|f\|_{s}$, whereh=hX,S(z;r)is the local mesh norm of the point setXwith respect to the spherical capS(z;r). Our proof is intrinsic to the sphere, and makes use of the Videnskii inequality. A numerical test illustrates the theoretical result.
RIGIDITY OF GRAPH PRODUCTS OF ABELIAN GROUPS
Authors: GUTIERREZ MAURICIO , PIGGOTT ADAM 
Published: March 2008

AbstractWe show that if G is a group and G has a graph-product decomposition with finitely generated abelian vertex groups, then G has two canonical decompositions as a graph product of groups: a unique decomposition in which each vertex group is a directly indecomposable cyclic group, and a unique decomposition in which each vertex group is a finitely generated abelian group and the graph satisfies the T0 property. Our results build on results by Droms, Laurence and Radcliffe.
Erratum to ‘Semi-hyperbolic fibered rational maps and rational semigroups’ (Ergodic Theory and Dynamical Systems 26 (2006), 893–922)
Authors: SUMI HIROKI 
Published: March 2008

AbstractWe give a correction to the assumption of Theorems 1.12 and 2.6 in the paper [H. Sumi. Semi-hyperbolic fibered rational maps and rational semigroups. Ergod. Th. & Dynam. Sys.26 (2006), 893–922].
Biofuels from Microalgae
Authors: Li Yanqun , Horsman Mark , Wu Nan , Lan Christopher Q. , Dubois‐Calero Nathalie 
Published: March 2008

AbstractMicroalgae are a diverse group of prokaryotic and eukaryotic photosynthetic microorganisms that grow rapidly due to their simple structure. They can potentially be employed for the production of biofuels in an economically effective and environmentally sustainable manner. Microalgae have been investigated for the production of a number of different biofuels including biodiesel, bio‐oil, bio‐syngas, and bio‐hydrogen. The production of these biofuels can be coupled with flue gas CO2 mitigation, wastewater treatment, and the production of high‐value chemicals. Microalgal farming can also be carried out with seawater using marine microalgal species as the producers. Developments in microalgal cultivation and downstream processing (e.g., harvesting, drying, and thermochemical processing) are expected to further enhance the cost‐effectiveness of the biofuel from microalgae strategy.
The First Training Workshop on Permafrost Research Methods: IMPETUS 2007: OSL‐APECS‐PYRN Training Workshop; St. Petersburg, Russia, 29 November to 2 December 2007
Authors: Lantuit H. , Kassens H. , Johansson M. , Timokhov L. , Haltigin T. , Baeseman J. , Volkmann‐Lark K. 
Published: March 2008

Fifty young researchers from 14 countries met in St. Petersburg, Russia, to learn about the latest methods used in permafrost research and engineering and to discuss future plans to address climate change issues in permafrost areas. This workshop was an official International Polar Year (IPY) event organized jointly by the Otto Schmidt Laboratory for Polar and Marine Sciences (OSL) in St. Petersburg, the Permafrost Young Researchers Network (PYRN), and the Association of Polar Early Career Scientists (APECS).The workshop provided insights into the latest techniques and methods used in permafrost research in fields as diverse as permafrost modeling, investigations of mountain ice segregation, bubbling from thermokarst lakes, and submarine permafrost detection. It brought together experts to provide young investigators with a multidisciplinary and cross‐border perspective on permafrost research, a much needed approach in a discipline marked by strong research history yet strongly entangled within national borders. Presentations and speaker biographies are now available on the conference Web site (http://pyrn.ways.org/activities/pyrn‐meetings/2007‐saint‐petersburg).
AGU Scientists Host Teacher Workshop in Ethiopia
Authors: Moldwin Mark , Yizengaw Endawoke , Scherrer Deborah K. , Rabellosoares M. Cristina , Reiff Patricia , Sumners Carolyn 
Published: March 2008

When you look at a map of the world showing the location of ground‐based space physics instrumentation (radars, magnetometers, ionosondes, GPS dual‐frequency receivers, and lidars), you quickly recognize Africa's lack of space physics research infrastructure. One priority of the United Nations—sponsored International Heliophysical Year (IHY) is the development of such an infrastructure in Africa.Satellite data have shown that the equatorial ionospheric density structures, especially at the equatorial region in the African continent, respond to space weather effects differently than do other parts of the Earth. For example, in the African equatorial region, satellite observations show that depleted density irregularities known as bubbles are much deeper than the bubbles observed in any other longitudinal sectors, and are very active year round in Africa compared with other regions. Observations also show that the depleted density in Africa rises to high altitude (up to 1000+ kilometers) more frequently compared with other longitudes.
Increases Proposed for U.S. Energy Department, But EPA Funding Would Be Cut
Authors: Showstack Randy 
Published: March 2008

The Bush administration's proposed fiscal year (FY) 2009 budget request would cut the U.S. Environmental Protection Agency's (EPA) funding to US$7.14 billion, a decrease of $330 million, or 4.4%, from the 2008 funding level. However, the administration's proposed budget request for the U.S. Department of Energy (DOE) would boost that agency's funding to $25 billion, an increase of $1.07 billion over 2008.The EPA budget request would allow the agency to “continue to deliver environmental results today, as well as keep EPA on course to deliver a cleaner, healthier tomorrow,” according to EPA administrator Stephen Johnson. “This budget represents government at its best: It helps EPA meet our environmental goals while being responsible stewards of taxpayers' dollars.”
Tamisiea Receives 2007 Geodesy Section Award
Authors: Leuliette Eric , Tamisiea Mark 
Published: March 2008

Mark Tamisiea has made significant and original advances in solid Earth geophysics and has begun to be an important leader in the geodesy community. He has actively applied models of glacial isostatic adjustment and gravity data from the GRACE mission to address practical problems in ice sheet history, sea level variation, and short‐ and long‐term solid Earth deformation.After his undergraduate training in physics at Grinnell College, Mark completed a Ph.D. with John Wahr at the University of Colorado. He was a postdoctoral fellow with Jerry Mitrovica at the University of Toronto and a geophysicist at the Harvard Smithsonian Observatory with Jim Davis. At present, he is a research scientist at Proudman Oceanographic Laboratory.
Recent moon jelly (Aurelia sp.1) blooms in Korean coastal waters suggest global expansion: examples inferred from mitochondrial COI and nuclear ITS-5.8S rDNA sequences
Authors: Ki Jang-Seu , Hwang Dae-Sik , Shin Kyoungsoon , Yoon Won Duk , Lim Donghyun , Kang Young Shil , Lee Yoon , Lee Jae-Seong 
Published: March 2008

AbstractKi, J-S., Hwang, D-S., Shin, K., Yoon, W. D., Lim, D., Kang, Y. S., Lee, Y., and Lee, J-S. 2008. Recent moon jelly (Aurelia sp.1) blooms in Korean coastal waters suggest global expansion: examples inferred from mitochondrial COI and nuclear ITS-5.8S rDNA sequences. – ICES Journal of Marine Science, 65: 443–452. The moon jelly Aurelia was found recently in Korean coastal environments, and its dense blooms caused economic losses for fisheries and power plants. The species is tentatively recognized as Aurelia aurita; yet, its identity and origin remain elusive. To find reliable molecular evidence for its identity, we determined the DNA sequence of the mitochondrial cytochrome c oxidase subunit I gene and nuclear ITS-5.8S rDNA of specimens collected from different Korean locations. We compared the nuclear and mitochondrial DNA data among specimens and demonstrated that all Korean Aurelia have an identical genotype. BLAST searches demonstrated that the Korean Aurelia matched the previously designated Aurelia sp.1. Parsimony and relevant phylogenetic analyses of the genus Aurelia demonstrated that the genotypes of Korean, Japanese, and Californian Aurelia sp.1 were nearly identical (>99.6% similarity), whereas they were significantly different (<84.1% similarity) from other Aurelia. This suggests that Aurelia sp.1, which occur in the three regions, are descendants of a single population and may have dispersed from one location. However, the dispersal time and origin of Aurelia sp.1 still remain uncertain.