bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deciphering morphological variation in the braincase of caecilian amphibians (gymnophiona)
Authors: Maddin Hillary C. 
Published: April 2011

AbstractHigh levels of morphological homoplasy have hindered progress in understanding morphological evolution within gymnophione lissamphibians. Stemming from the hypothesis that the braincase has the potential to yield phylogenetic information, the braincases of 27 species (23 genera) of gymnophione amphibians were examined using high‐resolution micro‐computed tomography and histologically prepared specimens. Morphology of the brain and its relationship to features of the braincase is described, and it is shown that eight different patterns exist in the distribution of foramina in the antotic region. The distribution of variants is congruent with molecule‐based phylogeny. Additionally, all variants are shown to correspond directly to stages along developmental continua, suggesting that the evolutionary truncation of development in the antotic region at various stages has driven the evolution of morphology in this region. Attempts to correlate the observed morphology with proxies of putative heterochronic events (including those attributable to burrowing, life history, and size) fail to explain the distribution of morphology if each proxy is considered separately. Thus, it is concluded that either currently unrecognized causes of heterochrony or combinations thereof have influenced morphology in different lineages independently. These data identify clades whose morphology can now be reconsidered in light of previously unrecognized heterochronic events, thereby providing a foundation for future analyses of the evolution of morphology within Gymnophiona as a whole. Most significantly, these data confirm, for the first time in a lissamphibian group, that the braincase can preserve important phylogenetic information that is otherwise obscured in regions of the skull that experience strong influences from functional constraints. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
Morphology of the gas bladder in bumblebee catfishes (Siluriformes, Pseudopimelodidae)
Authors: Birindelli José L. O. , Shibatta Oscar A. 
Published: April 2011

AbstractThe gross morphology of the gas bladder is described and compared for representatives of all valid genera of Pseudopimelodidae (Siluriformes). Cephalosilurus albomarginatus and species of Batrochoglanis, and Microglanis have the most basic form: a large, cordiform gas bladder with a simple internal T‐shaped septum. Cephalosilurus apurensis, C. fowleri, and C. nigricauda also have a large, cordiform gas bladder, but they have well‐developed trabeculae associated with the internal T‐shaped septum, and a pair of well‐developed constrictor muscles inserted on the external wall; the latter feature is present in most species of Pimelodidae, but absent in all other catfishes. The monotypic Lophiosilurus alexandri also has well‐developed constrictor muscles, and its gas bladder is moderately sized. The species of Pseudopimelodus and Cruciglanis have a diminutive gas bladder partially divided into two lateral sacs without internal communication, and lack constrictor muscles. The parapophysis of the fourth vertebra is a wide and long shelf connected to the dorsal surface of the gas bladder in most pseudopimelodid genera. However, in the species of Pseudopimelodus and Cruciglanis the parapophysis of the fourth vertebra is shorter and has its anterior ramus folded back, partially covering the gas bladder anteroventrally; and the tympanic opening is smaller than in species of the other genera. Five phylogenetic characters are proposed based on the morphology of the gas bladder and associated structures in species of Pseudopimelodidae, and the evolution of those characters in the family is discussed. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
A‐model as a way of squirrel cage induction motor modelling used in pumps drive systems
Authors: Koziorowska Anna , Bartman Jacek 
Published: April 2011

SUMMARYThis paper presents application of differential equations in modelling and simulation tests of water supply network pumps drive system together with powered water supply pipelines. The description is preceded with an analysis of practically applicable mathematical models representing drive systems with induction motors and PWM converter. Models of electric devices and their elements, from the viewpoint of the methods used to describe the phenomena occurring in them, can be divided into three basic groups: circuit models, semi‐field models, and field models. Each of these groups has its own purpose depending on the complexity of the modelled electric system, the types of devices, and the required accuracy in the reconstruction of processes actually occurring in the system. In the case under consideration, sufficient accuracy is ensured by circuit models. Mathematical models of PWM converter, squirrel‐cage induction motor, and pump together with a pipeline allow to carry out computer simulations of the whole drive system consisting of the above‐listed elements. Simulations of the system of such complexity definitely pose a more difficult problem than simulation of each of the elements performed separately. In the following, mathematical models of individual elements and selected simulation tests of the system are presented. Copyright © 2011 John Wiley & Sons, Ltd.
Deviation from van't Hoff dependence in RP‐LC induced by tautomeric interconversion observed for four compounds
Authors: Galaon Toma , David Victor 
Published: April 2011

AbstractThe most encountered situations in reversed‐phase liquid chromatography for temperature dependence of retention are those obeying the linear equation known as the van't Hoff plot. When studying compounds that are involved in structural modifications, it is likely that the temperature dependences of their retention factors do not follow this rule. It is the aim of this paper to report some particular cases when compounds involved in tautomeric interconversion have a different retention behavior with temperature: a deviation from the linearity of ln k on 1/T, or, in certain temperature ranges, temperature increase leading to a retention increase. Examples of compounds exhibiting deviation from the van't Hoff temperature dependence are piroxicam, drotaverine, vincamine, and epivincamine. A simple thermodynamic model relying on tautomeric equilibria in mobile phase is proposed for these compounds, which gives a polynomial dependence between ln k and 1/T.
Determination of trace biogenic amines with 1,3,5,7‐tetramethyl‐8‐(N‐hydroxysuccinimidyl butyric ester)‐difluoroboradiaza‐s‐indacene derivatization using high‐performance liquid chromatography and fluorescence detection
Authors: Gao Pan‐Feng , Guo Xiao‐Feng , Wang Hong , Zhang Hua‐Shan 
Published: April 2011

AbstractA reversed‐phase high‐performance liquid chromatographic method based on chemical derivatization with fluorescence detection has been developed for analyzing biogenic amines in food and environmental samples. A BODIPY‐based fluorescent reagent, 1,3,5,7‐tetramethyl‐8‐(N‐hydroxysuccinimidyl butyric ester)‐difluoroboradiaza‐s‐indacene (TMBB‐Su), was employed for the derivatization of these biogenic amines at 20°C for 20 min in pH 7.20 borate buffer after careful investigation of the derivatization conditions including reagent concentration, buffer solution, reaction temperature and reaction time. Separation of biogenic amines with gradient elution was conducted on a C8 column with methanol–tetrahydrofuran–water as mobile phase. The detection limits were obtained in the range from 0.1 to 0.2 nM (signal‐to‐noise=3). This procedure has been validated using practical samples. The study results demonstrated a potential of employing high‐performance liquid chromatography (HPLC) with 1,3,5,7‐tetramethyl‐8‐(N‐hydroxysuccinimidyl butyric ester)‐difluoroboradiaza‐s‐indacene labeling as a tool for quantitative analysis of biogenic amines involved in various matrices.
Kinetics of copper(II)‐catalyzed oxidation of S(IV) by atmospheric oxygen in ammonia buffered solutions
Authors: Sharma Anil Kumar , Singh Abhilasha , Mehta R. K. , Sharma Sudhanshu , Bansal S. P. , Gupta K. S. 
Published: April 2011

AbstractTo understand the chemistry of Cu(II)–NH3–S(IV)–O2 system, the kinetics of the oxidation of sulfur(IV) catalyzed by amminecopper(II) complexes has been studied in the ammonia‐buffered solutions. Sulfur(IV) is oxidized to sulfate. The complexes, Cu(NH3)2+, Cu(NH3)22+, and Cu(NH3)2+3 appear to be equally reactive and Cu(NH3)42+ appears to be unreactive. The kinetics obey the rate law:

equation image

where α1 and γ1 are the rate constants for O2‐dependent and O2‐independent pathways, respectively, for Cu(NH3)2+, Cu(NH3)2+2, and Cu(N H3)32+ complexes, which appear to be equally reactive. The values of α1 and γ1 were found to be (1.32 ± 0.21) × 106 L2 mol−2 s−1 (1.74 ± 0.40) × 109 L3 mol−3 s−1respectively at 30°C. The reaction rate is not influenced by the presence of ethanol—a free radical scavenger, so a nonradical mechanism has been proposed. The results of this study are useful in understanding the atmospheric chemistry of aqueous phase autoxidation of dissolved sulfur dioxide in copper(II)–ammonia–sulfur(IV)–oxygen system at high pH. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 379–392, 2011
Uncertainty of Arrhenius parameters
Authors: Nagy Tibor , Turányi Tamás 
Published: April 2011

AbstractChemical kinetics databases for many elementary gas‐phase reactions provide the recommended values of the Arrhenius parameters, the temperature range of their validity, and the temperature dependence of the uncertainty of the rate coefficient k. An analytical expression is derived that describes the temperature dependence of the uncertainty of k as a function of the elements of the covariance matrix of the Arrhenius parameters. Based on this analytical expression, the various descriptions of the temperature dependence of the uncertainty of k used in the combustion, and in the IUPAC and JPL atmospheric chemical databases are analyzed in detail. Recommendations are given for an improved representation of the uncertainty information in future chemical kinetics databases using the covariance matrix of the Arrhenius parameters. Utilization of the joint uncertainty of the Arrhenius parameters is needed for a correct uncertainty analysis in varying temperature chemical kinetic systems. A method is suggested for the determination of the covariance matrix and the joint probability density function of the Arrhenius parameters from the present uncertainty information given in the kinetics databases. The method is demonstrated on seven gas kinetic reactions exhibiting different types of uncertainty representation. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 359–378, 2011
Synthesis of hydroxyethylhydrazine by the Raschig process and comparison with synthesis by the alkylation process
Authors: Goutelle V. , Pasquet V. , Hajj A. El , Bougrine A. J. , Delalu H. 
Published: April 2011

AbstractThe Raschig synthesis of hydroxyethylhydrazine (HEH) is studied, that is, the reaction of monochloramine on ethanolamine. The formation of HEH is monitored by UV spectrometry, and the influence of temperature and pH is studied. The primary reaction is an SN2‐type mechanism, whereas the main secondary reaction is the oxidation of HEH by monochloramine. This reaction is also monitored by UV spectrometry, and the oxidation product is identified by GC–MS analysis, showing the formation of hydroxyethylhydrazone. The reaction mechanisms and the rate constants were determined, and the results permit establishing the main reactions occurring during HEH synthesis. These reactions were validated in a concentrated medium, with the systematic study of the influence of the molar ratio p ([HEH]0/[NH2Cl]0) and the final sodium hydroxide concentration and temperature. A comparison is made with the other synthesis process already published, that is, the alkylation of hydrazine by either chloroethanol or epoxide. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 331–344, 2011
Quasiclassical trajectory study of the rotational distribution for the O+NO(v = 0) fundamental vibrational excitation
Authors: Galvão B. R. L. , Corzo‐Espinoza J. A. , Caridade P. J. S. B. , Varandas A. J. C. 
Published: April 2011

AbstractQuasiclassical trajectories have been run to study the fundamental one‐quantum vibrational transition formed from collisions of ground‐state nitric oxide with atomic oxygen at temperatures of 500, 750, and 1000 K. Two adiabatic potential energy surfaces of different symmetry (2A′ and 2A″ of NO2) have been utilized. The rate constant for the title process is given along with the rotational distributions, and the results shown to corroborate previous atmospheric models that describe the nascent state by a Maxwell–Boltzmann distribution at the local temperature. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 345–352, 2011
Phenolysis and aminolysis of 4‐nitrophenyl and 2,4‐dinitrophenyl S‐methyl thiocarbonates in aqueous ethanol
Authors: Castro Enrique A. , Aliaga Margarita E. , Cepeda Marjorie , Santos José G. 
Published: April 2011

AbstractThe reactions of S‐methyl O‐(4‐nitrophenyl) thiocarbonate (1) and S‐methyl O‐(2,4‐dinitrophenyl) thiocarbonate (2) with a series of secondary alicyclic (SA) amines and phenols are subjected to a kinetic investigation. Under nucleophile excess, pseudo‐first‐order rate coefficients (kobs) are obtained. Plots of kobs against the free nucleophile concentration at constant pH are linear with slopes kN. The Brønsted plots (log kN vs. nucleophile pKa) for the reactions are linear with slope (β) values in the 0.5–0.7 range, in accordance with concerted mechanisms. Comparison of the SA aminolysis of 1 with the same one carried out in water shows that the change of solvent from water to aqueous ethanol destabilizes the zwitterionic tetrahedral intermediate, changing the mechanism from stepwise to concerted. This destabilization is greater than that due to the change from SA amines to quinuclidines. For the phenolysis reactions, the kN values in aqueous ethanol are smaller than those for the same reactions in water. Considering that the nucleophile is an anion, this result is unexpected because the anion should be more stabilized in the more polar solvent. This result is explained by the facts that the phenoxide reactant has a negative charge that is delocalized in the aromatic ring and the transition state is highly polar. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 353–358, 2011
Applications of mass spectrometry to metabolomics and metabonomics: Detection of biomarkers of aging and of age‐related diseases
Authors: Mishur Robert J. , Rea Shane L. 
Published: April 2011

AbstractEvery 5 years or so new technologies, or new combinations of old ones, seemingly burst onto the science scene and are then sought after until they reach the point of becoming commonplace. Advances in mass spectrometry instrumentation, coupled with the establishment of standardized chemical fragmentation libraries, increased computing power, novel data‐analysis algorithms, new scientific applications, and commercial prospects have made mass spectrometry‐based metabolomics the latest sought‐after technology. This methodology affords the ability to dynamically catalogue and quantify, in parallel, femtomole quantities of cellular metabolites. The study of aging, and the diseases that accompany it, has accelerated significantly in the last decade. Mutant genes that alter the rate of aging have been found that increase lifespan by up to 10‐fold in some model organisms, and substantial progress has been made in understanding fundamental alterations that occur at both the mRNA and protein level in tissues of aging organisms. The application of metabolomics to aging research is still relatively new, but has already added significant insight into the aging process. In this review we summarize these findings. We have targeted our manuscript to two audiences: mass spectrometrists interested in applying their technical knowledge to unanswered questions in the aging field, and gerontologists interested in expanding their knowledge of both mass spectrometry and the most recent advances in aging‐related metabolomics. © 2011 Wiley Periodicals, Inc., Mass Spec Rev 31:70–95, 2012
Vertical response of pile raft foundations subjected to tunneling‐induced ground movements in layered soil
Authors: Huang Maosong , Mu Linlong 
Published: April 2011

SUMMARYA simplified analysis method has been developed to estimate the vertical movement and load distribution of pile raft foundations subjected to ground movements induced by tunneling based on a two‐stage method. In this method, the Loganathan–Polous analytical solution is used to estimate the free soil movement induced by tunneling in the first stage. In the second stage, composing the soil movement to the pile, the governing equilibrium equations of piles are solved by the finite difference method. The interactions between structural members (such as pile–soil, pile–raft, raft–soil, and pile–pile) are modeled based on the elastic theory method of a layered half‐space. The validity of the proposed method is verified through comparisons with some published solutions for single piles, pile groups, and pile rafts subjected to ground movements induced by tunneling. Good agreements between these solutions are demonstrated. The method is also used for a parametric study to develop a better understanding of the behavior of pile rafts influenced by tunneling operation in layered soil foundations. Copyright © 2011 John Wiley & Sons, Ltd.
Patient‐perceived outcomes of the AdVance sling up to 40 months post procedure
Authors: Suskind Anne M. , Bernstein Bruce , Murphy‐Setzko Marlene 
Published: April 2011

AbstractAimsThe objective of this study was to determine patient‐perceived outcomes of the AdVance sling over 40 months and to determine if results were durable over time.MethodsThis study represents a retrospective chart review of a single‐surgeon's experience with the AdVance sling paired with a follow‐up 5 question telephone survey performed in April 2010. The telephone survey consisted of 2 validated questions pertaining to patient satisfaction (the PGI‐I and the PGI‐S) along with 3 additional questions pertaining to number of pads per day (PPD) used, additional therapies tried, and whether or not the patient would recommend the procedure to a friend. Ordinal and non‐normally distributed variables were analyzed via rank order correlation (Spearman's rho) and the association between the number of pads per day used at the time of telephone survey and progressing time since sling procedure was plotted with linear regression analysis.ResultsThe surgeon performed a total of 44 AdVance sling procedures from 2006 to April 2011. 42 charts were available for review and 36 (85.7%) patients were reached via telephone. Average patient age was 63.64 years and average time in months since sling procedure was 18.76. Average number of PPD used was 2.11 preoperatively, 0.38 at the one month post‐operative visit, and 1.67 at time of the telephone survey. Additionally, advancing time since sling operation correlated with higher numbers of PPD. 34/36 patients would recommend the procedure to a friend.ConclusionDespite patient satisfaction with the sling procedure, our data show that patients were using an increasing number of PPD as time from sling procedure advanced. This is important information for patients and physicians to consider when choosing this procedure. Neurourol. Urodynam. 30:1267–1270, 2011. © 2011 Wiley‐Liss, Inc.
Reproducibility of urodynamic filling sensation at weekly interval in healthy volunteers and in women with detrusor overactivity
Authors: Van Meel Tom David , Wyndaele Jean‐Jacques 
Published: April 2011

AbstractAimsTo evaluate the reproducibility of bladder sensation during standardized filling cystometry in female volunteers and overactive bladder (OAB) patients, repeated with weekly interval.MethodsWe recruited 13 female nulliparous volunteers (age 21–47) and 17 female patients with OAB between (age 18–72). They participated in three investigation periods, each separated by 7 days to assess reproducibility of sensation related to standardized cystometry. Subjects were asked to report all sensations they felt during bladder filling.ResultsThe previously described pattern of sensation was reported during bladder filling in all. Consecutive sensations corresponded to statistically higher bladder volumes. Volumes, at which different sensations of bladder filling were reported, were significantly higher in controls than in OAB patients [first sensation of filling (FSF) P = 0.003, first desire to void (FDV) P < 0.0001, and strong desire to void (SDV) P < 0.0001]. The sensation/volume ratios were significantly higher in patients with OAB than in the healthy volunteers: FSF occurred at mean 46% and FDV at mean 73% of SDV in OAB patients, compared to 36% and 64% in healthy volunteers. Sensations proved highly reproducible when determined with weekly interval.ConclusionsOur data demonstrate that cystometric filling sensation determined in a standardized way with weekly interval is highly reproducible in healthy and in OAB patients. This finding has, in our opinion, clinical importance as it shows that the technique is reliable both for a sensory evaluation of the LUT as to study influence of treatment aimed at changing this sensation. Neurourol. Urodynam. Neurourol. Urodynam. 30: 1586–1590, 2011. © 2011 Wiley Periodicals, Inc.
Neumann‐Neumann methods for a DG discretization on geometrically nonconforming substructures
Authors: Dryja Maksymilian , Galvis Juan , Sarkis Marcus 
Published: April 2011

AbstractA discontinuous Galerkin discretization for second order elliptic equations with discontinuous coefficients in 2D is considered. The domain of interest Ω is assumed to be a union of polygonal substructures Ωi of size O(Hi). We allow this substructure decomposition to be geometrically nonconforming. Inside each substructure Ωi, a conforming finite element space associated to a triangulation
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*} {\mathcal{T}}_{h_i}(\Omega_i)\end{align*}\end{document}
is introduced. To handle the nonmatching meshes across ∂Ωi, a discontinuous Galerkin discretization is considered. In this article, additive and hybrid Neumann‐Neumann Schwarz methods are designed and analyzed. Under natural assumptions on the coefficients and on the mesh sizes across ∂Ωi, a condition number estimate
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*} C(1 + \max_i\log \frac{H_i}{h_i})^2\end{align*}\end{document}
is established with C independent of hi, Hi, hi/hj, and the jumps of the coefficients. The method is well suited for parallel computations and can be straightforwardly extended to three dimensional problems. Numerical results are included. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2012