bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applying the concepts of density functional theory to simple systems
Authors: Pearson Ralph G. 
Published: November 2007

AbstractEquations are derived for the chemical potential and local hardness of the ground states of helium and the related two electron ions. With these properties it is possible to correct the energies of the simple single‐zeta wave functions to the nearly exact values. The calculations are simple for these simple systems. In principle, it is possible to extend this method to all atoms and molecules. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A computational study of open‐chain epothilone analogue
Authors: Kamel Karol , Rusinska‐Roszak Danuta 
Published: November 2007

AbstractMolecular mechanics (MM/Ambers) calculations were applied to probe the conformational profile of open‐chain epothilone analogue [Org Lett 2006, 8, 685], cytotoxic against some cell lines. Geometries of the most stable conformers were optimized at DFT level using the B3LYP functional and then compared to known both experimental and virtual conformers of epothilone. One of the most stable structures is III (1.47 kcal/mol above global minimum) which represents high similarity to the appropriate fragment of the Taylor's model of epothilone A, but two other conformers: XIV and XX, although they have almost the same conformation as the mother structure, are very unstable (6.7 and 12.4 kcal/mol above the global minimum). © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A quantum‐chemical study of phosphor impurity in BaTiO3 crystal
Authors: Stashans Arvids , Vidal Gabriela 
Published: November 2007

AbstractStructural and electronic effects produced by a P impurity in the cubic and tetragonal BaTiO3 lattices are investigated using a simple quantum chemical computer code based on the Hartree–Fock methodology. The obtained atomic displacements due to the defect present in otherwise pure crystal are mainly toward the impurity atom, thus reducing the interatomic distances within the defective region. It is also found that the phosphor produces some redistribution of electron density from the defect‐neighboring atoms toward the chemical bonds thus diminishing the charges on atoms. We also observe a local energy level in the band‐gap of material being composed mainly of P 3s atomic orbital. The level finds itself close to the top of the upper valence band, in no case contributing into the n‐type conductivity in BaTiO3. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Analysis of transition‐metal acetylacetonate complexes by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Wyatt Mark F. , Havard Stephen , Stein Bridget K. , Brenton A. Gareth 
Published: November 2007

AbstractTransition‐metal acetylacetonate complexes of the form Metal(acac)2, where Metal = Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), and Metal(acac)3, where Metal = V(III), Cr(III), Mn(III), Fe(III), and Co(III), were investigated by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). The data was acquired using the aprotic, electron transfer matrix, 2‐[(2E)‐3‐(4‐tert‐butylphenyl)‐2‐methylprop‐2‐enylidene]malononitrile (DCTB), and the observation of positive radical ions is shown clearly to depend on the metal element and the oxidation state it occupies. The ionization energy of DCTB was calculated to be 8.08 eV by density functional theory methods, which is notably lower than the experimental value, but within the range of other computational values. This value is very close to those of the analytes, so the existing electron transfer mechanism which is based on the ionization energies of the matrix and analyte, cannot be used predictively. Similarly, the data neither proves nor disproves the validity of the existing electron transfer ionization mechanism, with respect to metal coordination complexes without strong chromophores. In this case, periodic trends may be more useful in explaining the observed species and the prediction of species from sets of similar complexes. The addition of a sodium salt benefits the MALDI‐TOFMS characterization of certain compounds studied, but the benefit of the addition of ammonium or silver salts is negligible. Copyright © 2007 John Wiley & Sons, Ltd.
The potential role of tributaries as seed sources to an impoundment in Northern Sweden: a field experiment with seed mimics
Authors: Bång Åsa , Nilsson Christer , Holm Svante 
Published: November 2007

AbstractFragmentation and flow regulation of rivers by large dams are known to obstruct the longitudinal dispersal of waterborne plant propagules between impoundments, and to affect plant community composition. However, even several decades after a dam has been built, impoundments may still have a relatively species‐rich riparian flora. We hypothesized that free‐flowing tributaries act as the major gene pools for such impoundments, thus alleviating the fragmenting effect large dams have on the main channel. The importance of tributaries as seed sources was tested by releasing wooden seed mimics in three different‐sized (0.22–6.93 m3 s−1) tributaries of an impoundment in the Ume River in Northern Sweden. In each tributary seed mimics were released, during the spring flood peak, from three points approximately 1, 2 and 3 km upstream the outlet in the impoundment. The importance of a tributary as a seed source increased with tributary size. Of the 9000 released seed mimics 1.5% reached the impoundment; 1.2% of the 9000 originated from the largest tributary and 0.3% from the middle‐sized one. The smallest tributary retained all its mimics. Copyright © 2007 John Wiley & Sons, Ltd.
Ignorability and stability assumptions in neighborhood effects research
Authors: VanderWeele Tyler J. 
Published: November 2007

AbstractTwo central assumptions concerning causal inference in the potential outcomes framework for estimating neighborhood effects are examined. The stable unit treatment value assumption in the context of neighborhood effects requires that an individual's outcome does not depend on the treatment assigned to neighborhoods other than the individual's own neighborhood. The assumption is important in that it makes estimation feasible, although some progress can be made even when the assumption is relaxed. Some discussion is given concerning the contexts in which the neighborhood‐level stable unit treatment value assumption is likely to hold. The ignorability assumption allows the researcher to move from conclusions about association to conclusions about causation. In the context of neighborhood‐wide interventions, the ignorability assumption for the individual‐level potential outcomes framework can be easily adapted for neighborhood effects. Copyright © 2007 John Wiley & Sons, Ltd.
IPOG/IPOG‐D: efficient test generation for multi‐way combinatorial testing
Authors: Lei Yu , Kacker Raghu , Kuhn D. Richard , Okun Vadim , Lawrence James 
Published: November 2007

AbstractThis paper presents two strategies for multi‐way testing (i.e.t‐way testing witht>2). The first strategy generalizes an existing strategy, called in‐parameter‐order, from pairwise testing to multi‐way testing. This strategy requires all multi‐way combinations to be explicitly enumerated. When the number of multi‐way combinations is large, however, explicit enumeration can be prohibitive in terms of both the space for storing these combinations and the time needed to enumerate them. To alleviate this problem, the second strategy combines the first strategy with a recursive construction procedure to reduce the number of multi‐way combinations that have to be enumerated. Both strategies are deterministic, i.e. they always produce the same test set for the same system configuration. This paper reports a multi‐way testing tool called FireEye, and provides an analytic and experimental evaluation of the two strategies. Copyright © 2007 John Wiley & Sons, Ltd.
Process intensification of whole‐cell biocatalysis with ionic liquids
Authors: Weuster‐Botz Dirk 
Published: November 2007

AbstractThe unique properties of room temperature ionic liquids such as non‐volatility, nonflammability, and, in many cases, high thermal and chemical stability have made them an environmentally attractive alternative to organic solvents. Biphasic biocatalytic processes with nonmiscible liquid phases are usually applied with whole‐cell biocatalysts to overcome low water solubility of substrates or products, inhibitory effects of the reactants on the biocatalyst, or low stability of substrates or products in the aqueous phase. The surprising noninvasive effects on cellular membranes of hydrophobic ionic liquids especially of those with hexafluorophosphate and bis(trifluoromethylsulfonyl)imide anions in biphasic ionic liquid/water systems make them superior to many organic solvents so far applied in whole‐cell biotransformations. Impressive process intensification in simple biphasic batch processes was recently demonstrated on the examples of asymmetric synthesis with whole‐cell biocatalysts, if the distribution coefficients of inhibitory substrates and products between ionic liquids and aqueous phase exceed a log D of about 2 (e.g., ketones and β‐ketoesters with lipophilic side chains and their corresponding chiral alcohols). © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 334–340; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20130
Fertility outcomes following expectant management of tubal ectopic pregnancy
Authors: Helmy S. , Sawyer E. , Ofili‐Yebovi D. , Yazbek J. , Nagi J. Ben , Jurkovic D. 
Published: November 2007

AbstractObjectivesTo evaluate fertility outcome after the expectant management of tubal ectopic pregnancy.MethodsOur dedicated early pregnancy database was searched for all women diagnosed with a tubal ectopic pregnancy between January 1999 and June 2003 who were either managed expectantly or underwent a salpingectomy. They were contacted to enquire about their ability to conceive following the ectopic pregnancy and about the outcomes of any subsequent pregnancies.ResultsFour hundred and forty‐four women had a diagnosis of tubal ectopic pregnancy, and 173 (39%) were successfully contacted. A total of 146/173 (84.4%; 95% CI, 79–89.8%) tried for another pregnancy: 49/59 (83.1%; 95% CI, 73.4–92.6%) in the expectant management and 97/114 (85.1%; 95% CI, 78.4–91.6%) in the salpingectomy group (P > 0.05). Spontaneous intrauterine pregnancy occurred in 41/49 (83.7%; 95% CI, 73.3–94.2%) women managed expectantly and in 62/97 (63.9%; 95% CI, 54.4–73.5%) women managed surgically (odds ratio 2.89; 95% CI, 1.22–6.86%). The risk of recurrent ectopic pregnancy was not significantly different between the two management groups.ConclusionsFertility outcomes following the expectant management of tubal ectopic pregnancy are comparable to those following salpingectomy. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Ophthalmic artery Doppler velocimetry in healthy pregnancy
Authors: Carneiro Raquel S. , Sass Nelson , Diniz Angelica L. , Souza Eder V. , Torloni Maria R. , Moron Antonio F. 
Published: November 2007

AbstractObjectivesTo establish normative data for ophthalmic artery Doppler parameters throughout a healthy pregnancy, to investigate the possible correlation between these Doppler measurements and gestational age, and to test intraobserver variability.MethodsA prospective cross‐sectional study was performed to assess various Doppler parameters in 276 healthy women between 20 and 39 weeks of gestation. The following measurements were obtained: pulsatility and resistance indices (PI, RI), peak systolic velocity (PSV), peak diastolic velocity (PDV), end diastolic flow velocity (EDFV), and peak ratio (PR). Quantile regression was used to estimate reference values throughout pregnancy and P < 0.05 was considered significant. The intraclass correlation coefficient (Intra‐CC) was used to calculate intraobserver variability.ResultsThe 5th and 95th prediction intervals for each gestational age are presented. No significant correlation was detected between Doppler indices and gestational age. Intra‐CC was excellent (0.996).ConclusionsReference values were generated for ophthalmic artery Doppler measurements, and they did not vary significantly during healthy pregnancy.
New Modes of Governance in the Shadow of Hierarchy: Self-regulation by Industry in Europe
Authors: HÉRITIER ADRIENNE , ECKERT SANDRA 
Published: November 2007

ABSTRACTIn technically complex areas, political actors increasingly rely on private actors to shape public policy, due to the greater expertise of private actors. This article theorises and empirically investigates the conditions under which self-regulation by industry (governance) emerges in environmental policy at the European level and asks how effective it is. Is a shadow of hierarchy (governmental intervention) needed to ensure the emergence and effectiveness of voluntary agreements? We show that the willingness to engage in self-regulation is prompted by the threat of governmental legislation. Once legislation has been pre-empted, environmental self-regulation is implemented under a weak shadow of hierarchy. We identify the causes of this weak control and explain the differential performance in the two sectors on the basis of different market incentives.
Effects of aboveground grazing on coupling among nitrifier activity, abundance and community structure
Authors: Le Roux Xavier , Poly Franck , Currey Pauline , Commeaux Claire , Hai Brigitte , Nicol Graeme W , Prosser James I , Schloter Michael , Attard Eléonore , Klumpp Katja 
Published: November 2007

Abstract
The influence of switches in grassland management to or from grazing on the dynamics of nitrifier activity, as well as the abundance of ammonia-oxidizing bacteria, AOB and ammonia-oxidizing archeae, AOA, was analyzed for two years after changing management. Additionally community structure of AOB was surveyed. Four treatments were compared in mesocosms: grazing on previously grazed grassland (G-G); no grazing on ungrazed grassland (U-U); grazing on ungrazed grassland (U-G) and cessation of grazing on grazed grassland (G-U). Nitrifier activity and abundance were always higher for G-G than U-U treatments and AOB community structure differed between these treatments. AOA abundance was in the same range as AOB abundance and followed the same trend. Grazing led to a change in AOB community structure within &lt;5 months and a subsequent (5–12 months) increase in nitrifier activity and abundance. In contrast, cessation of grazing led to a decrease in nitrifier activity and abundance within &lt;5 months and to a later (5–12 months) change in AOB community structure. Activity in G-U and U-G was similar to that in U-U and G-G, respectively, after 12 months. Sequence analysis of 16S rRNA gene clones showed that AOB retrieved from soils fell within the Nitrosospira lineage and percentages of AOB related to known Nitrosospira groups were affected by grazing. These results demonstrate that AOB and AOA respond quickly to changes in management. The selection of nitrifiers adapted to novel environmental conditions was a prerequisite for nitrification enhancement in U-G, whereas nitrification decrease in G-U was likely due to a partial starvation and decrease in the abundance of nitrifiers initially present. The results also suggest that taxonomic affiliation does not fully infer functional traits of AOB.
A novel DSF-like signal from Burkholderia cenocepacia interferes with Candida albicans morphological transition
Authors: Boon Calvin , Deng Yinyue , Wang Lian-Hui , He Yawen , Xu Jin-Ling , Fan Yang , Pan Shen Q , Zhang Lian-Hui 
Published: November 2007

Abstract
In addition to producing lethal antibiotics, microorganisms may also use a new form of antagonistic mechanism in which signal molecules are exported to influence the gene expression and hence the ecological competence of their competitors. We report here the isolation and characterization of a novel signaling molecule, cis-2-dodecenoic acid (BDSF), from Burkholderia cenocepacia. BDSF is structurally similar to the diffusible signal factor (DSF) that is produced by the RpfF enzyme of Xanthomonas campestris. Deletion analysis demonstrated that Bcam0581, which encodes an RpfF homologue, was essential for BDSF production. The gene is highly conserved and widespread in the Burkholderia cepacia complex. Exogenous addition of BDSF restored the biofilm and extracellular polysaccharide production phenotypes of Xanthomonas campestris pv. campestris DSF-deficient mutants, highlighting its potential role in inter-species signaling. Further analyses showed that Candida albicans germ tube formation was strongly inhibited by either coculture with B. cenocepacia or by exogenous addition of physiological relevant levels of BDSF, whereas deletion of Bcam0581 abrogated the inhibitory ability of the bacterial pathogen. As B. cenocepacia and C. albicans are frequently encountered human pathogens, identification of the BDSF signal and its activity thus provides a new insight into the molecular grounds of their antagonistic interactions whose importance to microbial ecology and pathogenesis is now becoming evident.
Multidimensional structure of stream flow regime in a hierarchy of landscapes within the U.S. Great Lakes basin
Authors: Shmagin Boris , Johnston Carol , Bridgham Scott 
Published: November 2007

AbstractStream flow data were used to evaluate a landscape hierarchy ranging from the Ontonagon River watershed (OW) to the upper peninsula of Michigan (MUP) to the entire Great Lakes basin (GLB). Flow records (1926-1988) were obtained for 45 USGS gauging stations within the GLB with drainage areas of 100-1450 sq. mi. Data were arranged in five initial matrixes with number of time series from 14 to 45. Factor analysis of average annual flow revealed from three to six patterns of stream runoff within distinct regions of the GLB. A typical watershed was selected to represent each of the five distinct regions identified for the period 1956-88, and its data were used to analyze monthly average flow values. This analysis identified two to five groupings of months with similar flow characteristics. For each annual time series of the typical five stream flow patterns of GLB regression equations were obtained from fore main indices of global atmospheric circulation. A similar analysis was completed for MUP and OW. Multilevel and multidimensional time spatial structure was discovered with factor as axis within landscape units as a homogeneous field. This kind of structure allows direct and more precise research for similar structures in atmosphere circulation and atmosphere-hydrosphere connections and regimes for entire GLB and its parts.
Quaternionic Dolbeault complex and vanishing theorems on hyperkähler manifolds
Authors: Verbitsky Misha 
Published: November 2007

AbstractLet (M,I,J,K) be a compact hyperkähler manifold, $\dim _{\mathbb {H}}M=n$, and L a non-trivial holomorphic line bundle on (M,I). Using the quaternionic Dolbeault complex, we prove the following vanishing theorem for holomorphic cohomology of L. If c1(L) lies in the closure $\hat K$ of the dual Kähler cone, then Hi(L)=0 for i>n. If c1(L) lies in the opposite cone $-\hat K$, then Hi(L)=0 for i<n. Finally, if c1(L) is neither in $\hat K$ nor in $-\hat K$, then Hi(L)=0 for $i\neq n$.
Higher Nash blowups
Authors: Yasuda Takehiko 
Published: November 2007

AbstractFor each non-negative integer n we define the nth Nash blowup of an algebraic variety, and call them all higher Nash blowups. When n=1, it coincides with the classical Nash blowup. We study higher Nash blowups of curves in detail and prove that any curve in characteristic zero can be desingularized by its nth Nash blowup with n large enough. Moreover, we completely determine for which n the nth Nash blowup of an analytically irreducible curve singularity in characteristic zero is normal, in terms of the associated numerical monoid.
On Rubin’s variant of the p-adic Birch and Swinnerton-Dyer conjecture
Authors: Agboola A. 
Published: November 2007

AbstractWe study Rubin’s variant of the p-adic Birch and Swinnerton-Dyer conjecture for CM elliptic curves concerning certain special values of the Katz two-variable p-adic L-function that lie outside the range of p-adic interpolation.
Quasiregular self-mappings of manifolds and word hyperbolic groups
Authors: Bridson Martin , Hinkkanen Aimo , Martin Gaven 
Published: November 2007

AbstractAn extension of a result of Sela shows that if Γ is a torsion-free word hyperbolic group, then the only homomorphisms Γ→Γ with finite-index image are the automorphisms. It follows from this result and properties of quasiregular mappings, that if M is a closed Riemannian n-manifold with negative sectional curvature ($n\neq 4$), then every quasiregular mapping f:M→M is a homeomorphism. In the constant-curvature case the dimension restriction is not necessary and Mostow rigidity implies that f is homotopic to an isometry. This is to be contrasted with the fact that every such manifold admits a non-homeomorphic light open self-mapping. We present similar results for more general quotients of hyperbolic space and quasiregular mappings between them. For instance, we establish that besides covering projections there are no π1-injective proper quasiregular mappings f:M→N between hyperbolic 3-manifolds M and N with non-elementary fundamental group.
Local solutions to positive characteristic non-Archimedean differential equations
Authors: dos Santos João Pedro Pinto 
Published: November 2007

AbstractIn the complex domain, one can integrate (solve) holomorphic ordinary differential equations (ODEs) near a non-singular point. We study the existence of solutions in the case of a positive characteristic base field k which is complete with respect to a non-Archimedean absolute value. ODEs are substituted by modules over a ring of analytic functions endowed with an action of all differential operators. The monodromy groups associated to the corresponding category are computed.
On number fields with given ramification
Authors: Chenevier Gaëtan 
Published: November 2007

AbstractLet E be a CM number field and let S be a finite set of primes of E containing the primes dividing a given prime number l and another prime u split above the maximal totally real subfield of E. If ES denotes a maximal algebraic extension of E which is unramified outside S, we show that the natural maps $\mathrm {Gal}(\overline {E_u}/E_u) \longrightarrow \mathrm {Gal}(E_S/E)$ are injective. We discuss generalizations of this result.
Power Efficiency of the Rotational-to-Linear Infinitely Variable
Cobotic Transmission
Authors: Faulring Eric L. , Colgate J. Edward , Peshkin Michael A. 
Published: November 2007

Abstract
Cobots are a class of robots that use infinitely variable transmissions to develop high fidelity programmable constraint surfaces. Cobots consume very little electrical power even when resisting high forces, and their transmissions are highly power efficient across a broad range of transmission ratios. We have recently introduced the Cobotic Hand Controller, a haptic display that illustrates the high dynamic range and low-power consumption achievable by cobots. In this paper, we present models of the rotational-to-linear rolling contact transmissions utilized in the Cobotic Hand Controller. We compare their efficiency to fixed-ratio gear trains. We also compare the overall power efficiency of the cobotic architecture to the power efficiency of a conventional electromechanical actuation scheme, for both constant and dynamic power flows. The cobotic architecture is shown to be more efficient at frequencies and power levels characteristic of voluntary human motions.