bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid Bayesian networks: making the hybrid Bayesian classifier robust to missing training data
Authors: Woody Nathaniel A. , Brown Steven D. 
Published: June 2003

AbstractMany standard classification methods are incapable of handling missing values in a sample. Instead, these methods must rely on external filling methods in order to estimate the missing values. The hybrid network proposed in this paper is an extension of the hybrid classifier that is robust to missing values. The hybrid network is produced by performing empirical Bayesian network structure learning to create a Bayesian network that retains its classification ability in the presence of missing data in both training and test cases. The performance of the hybrid network is measured by calculating a misclassification rate when data are removed from a dataset. These misclassification curves are then compared against similar curves produced from the hybrid classifier and from a classification tree. Copyright © 2003 John Wiley & Sons, Ltd.
SSRD: simple sequence repeats database of the human genome
Authors: Subramanian Subbaya , Madgula Vamsi M , George Ranjan , Kumar Satish , Pandit Madhusudhan W , Singh Lalji 
Published: June 2003

AbstractSimple sequence repeats are predominantly found in most organisms. They play a major role in studies of genetic diversity, and are useful as diagnostic markers for many diseases. The simple sequence repeats database (SSRD) for the human genome was created for easy access to such repeats, for analysis, and to be used to understand their biological significance. The data includes the abundance and distribution of SSRs in the coding and non‐coding regions of the genome, as well as their association with the UTRs of genes. The exact locations of repeats with respect to genomic regions (such as UTRs, exons, introns or intergenic regions) and their association with STS markers are also highlighted. The resource will facilitate repeat sequence analysis in the human genome and the understanding of the functional and evolutionary significance of simple sequence repeats. SSRD is available through two websites, http://www.ccmb.res.in/ssr and http://www.ingenovis.com/ssr. Copyright © 2003 John Wiley & Sons, Ltd.
Perimeter Effects on Ring Currents in Polycyclic Aromatic Hydrocarbons: Circumcoronene and Two Hexabenzocoronenes
Authors: Soncini Alessandro , Steiner Erich , Fowler Patrick W. , Havenith Remco W. A. , Jenneskens Leonardus W. 
Published: June 2003

AbstractCurrent‐density maps are calculated at an ab initio level for the three symmetrical polycyclic aromatic hydrocarbons, circumcoronene [1 (D6h)], hexabenzo[bc,ef,hi,kl,no,qr]coronene [2 a (D6h) and 2 b (D3d)], and hexabenzo[a,d,g,j,m,p]coronene [3 a (D6h), 3 b (D6) and 3 c (D3d)], all of which can be formally derived by annelation of benzene rings to a coronene core. Whilst 1 is planar, 2 has a non‐planar minimum that is effectively isoenergetic with its planar form, and 3 has a well defined non‐planar structure. The shape of the molecular boundary rather than the planarity of the molecule plays the critical rôle in the character of the predicted currents. Formal deletion of outer hexagons from circumcoronene (1) in two different ways produces either hexabenzocoronene 2 with a prediction of disjoint local benzenoid diatropic currents linked by a global perimeter, or 3 with a giant diatropic perimeter current enclosing a weak paramagnetic circulation on the central hexagon. The current density map of 1 is effectively a superposition of those of 2 and 3. Its strong diatropic perimeter current subsumes the six weaker diatropic benzenoid circulations evident in 2, and bifurcates in the six outer benzenoid rings that form the corners of the giant hexagon; its benzene “hub” sustains a diatropic current, as would be expected from the partial cancellation of the strong diatropic hub current of 2 by the weaker paratropic hub current of 3. The relationship between the three molecules is rationalised by considering orbital contributions to their current density maps.
The Regioselectivity of the Asymmetric Intermolecular Heck Reaction with Planar Chiral Diphosphine–Oxazoline Ferrocenyl Ligands
Authors: Tu Tao , Deng Wei‐Ping , Hou Xue‐Long , Dai Li‐Xin , Dong Xi‐Cheng 
Published: June 2003

AbstractA series of novel planar chiral diphosphine‐oxazoline ferrocenyl ligands were synthesized and used efficiently in the palladium‐catalyzed asymmetric intermolecular Heck reaction of 2,3‐dihydrofuran with aryl triflate and cyclohexenyl triflate. The tuning of the regioselectivity was realized by means of different palladium precursors and by changing the electronic factor of the ligands. A plausible rationale based on the existed mechanism is provided.
Cover Picture: Discrete Supramolecular Assemblies of Porphyrins Mediated by Coordination Compounds (Eur. J. Inorg. Chem. 13/2003)
Authors: Iengo Elisabetta , Zangrando Ennio , Alessio Enzo 
Published: June 2003

AbstractThe cover picture shows the X‐ray structure of an unprecedented supramolecular assembly comprising four porphyrins and six metal atoms (two Ru and four Zn); this very stable and symmetrical architecture was obtained by spontaneous self‐assembly through four 4′‐N(py)−Zn interactions of two equal bis(porphyrin)ruthenium self‐complementary building blocks. The design of this and other robust and shape‐persistent assemblies, obtained by coordination of meso‐pyridylporphyrins to ruthenium, palladium and zinc centers, is comprehensively discussed in the microreview by E. Alessio et al. on p. 2371 ff. NMR spectroscopy and X‐ray crystallography were used jointly for the unambiguous characterization of the new species in solution and solid state, respectively. Very often the adducts of nanoscopic dimensions, in which the number, position, relative distance and orientation of the chromophores is well defined, were obtained through hierarchical supramolecular self‐assembly: multi‐porphyrin components were used as building blocks for the metal‐mediated assembly of more elaborate architectures.
Lipid hydroperoxides determination in milk‐based infant formulae by gas chromatography
Authors: Lagarda María Jesús , Mañez José Gabriel , Manglano Pilar , Farré Rosaura 
Published: June 2003

AbstractA simple gas chromatograph using a flame ionization detector and a polar capillary column method is proposed for determining hydroperoxides in the lipid fraction of milkbased infant formulas. Tricosanoic acid is used as internal standard. The method includes the following steps: a) the extraction of fat with chloroform/methanol (2:1, v/v), b) the reduction of hydroperoxide acids to hydroxide acids with hydrogen gas and palladium as a catalyst, c) the transmethylation to obtain the methyl esters with acetyl chloride and methanol/ hexane (4:1, v/v), and d) an acetylation with acetic anhydride/ pyridine (4:1, v/v) to obtain an acetoxy derivate of the hydroxide present. Two chromatography runs, before and after the acetylation step, are carried out. The decrease in the retention time observed after the acetylation process is the criterion used to detect the hydroperoxide. A gas chromatography‐mass spectrometry analysis is applied to confirm the conversion of hydroperoxide acids to the acetylated forms and to identify the specific hydroperoxide structures.The estimated precision expressed as relative standard deviation (12.1%) and the accuracy, estimated by recovery assays (105 ± 28.3%) confirm the analytical quality of the method. In the milk‐based infant formula analyzed after storage of 11 months at 22 °C, the total hydroxide found corresponded to C18. The gas chromatography‐mass spectra obtained after the acetylation step confirmed the presence of methyl 9‐ and 13‐acetoxyoctadecanoate/s, respectively, derived from the corresponding peroxides.
Electrocatalytic Properties and Sensor Applications of Fullerenes and Carbon Nanotubes
Authors: Sherigara Bailure S. , Kutner Wlodzimierz , D'Souza Francis 
Published: June 2003

AbstractThe electrochemical behavior of fullerene and fullerene derivatives are reviewed with special reference to their catalytic and sensor applications. Recent work on carbon nanotubes, used as catalyst supports in heterogeneous catalysis and sensor development is also presented. An overview of recent progress in the area of fullerene electrochemistry is included. Several cases of electrocatalytic dehalogenation of alkyl halides, assisted by the electrode charge transfer to fullerenes, are discussed. Research work on the electrocatalysis of biomolecules, such as hemin, cytochrome c, DNA, coenzymes, glucose, ascorbic acid, dopamine, etc. have also been considered. Based on the studies of the interaction of fullerenes, fullerene derivatives, and carbon nanotubes with other molecules and biomolecules in particular, the possibilities for the preparation of electrochemical sensors and their application in electroanalytical chemistry are highlighted.
Cobalt Phthalocyanine‐Based Molecular Materials for the Electrocatalysis and Electroanalysis of 2‐Mercaptoethanol, 2‐Mercaptoethanesulfonic Acid, Reduced Glutathione and L‐Cysteine
Authors: Griveau Sophie , Gulppi Miguel , Pavez Jorge , Zagal José H. , Bedioui Fethi 
Published: June 2003

AbstractWe have investigated the electrocatalytic activity of cobalt tetra‐aminophthalocyanine (CoTAPc) for the one‐electron oxidation of thiols of various sizes, namely 2‐mercaptoethanol, 2‐mercaptoethanesulfonic acid, reduced glutathione and L‐cysteine, using adsorbed monomeric CoTAPc and electropolymerized poly‐CoTAPc films of different thickness on a vitreous carbon electrode. Our results show that the electrocatalytic activity of poly‐CoTAPc films towards the oxidation of the thiols increases slightly with the thickness of the film, but remains similar to that of the adsorbed monomeric CoTAPc. The higher stability of the electropolymerized poly‐CoTAPc films makes them attractive for applications in the activation and/or the detection of thiols. We have assessed this approach by designing ultra‐micro‐carbon‐fiber electrodes, coated with poly‐CoTAPc, and combining their use with different electrochemical techniques (cyclic voltammetry, differential pulse voltammetry and differential normal pulse amperometry) for the electroanalysis of the examined thiols.
Development of an Amperometric Sensor Highly Selective For Dopamine and Analogous Compounds Determination Using Bis(2,2′‐Bipyridil) Copper(II) Chloride Complex
Authors: Del Pilar Taboada Sotomayor Maria , Atsushi Tanaka Auro , Tatsuo Kubota Lauro 
Published: June 2003

AbstractThe use of [Cu(bipy)2]Cl2⋅6H2O as a biomimetic catalyst in the construction of an amperometric sensor for dopamine determination is reported. The sensor was prepared modifying a glassy carbon electrode with a Nafion membrane doped with [Cu(bipy)2]Cl2⋅6H2O complex. The sensor presented a higher response in 0.25 mol  L−1 phosphate buffer solution (pH 7.0), with an applied potential of −50 mV (vs. SCE). In the optimized operational conditions, a linear response range between 35 and 240 μmol  L−1, with a sensitivity of 2.02±0.07 nA l μmoL−1 cm−2 and detection limit of 8.0 μmol  L−1 were typically observed for the sensor. The response time presented for this sensor was 0.5 s, presenting the same response for at least 40 successive measurements, with good repeatability (3.0%) expressed as relative standard deviation for n=6. The difference of the response between four sensor preparations was 4%. A detailed investigation about the sensor response for other sixteen phenolic compounds and interfering species were carried out. The sensor was applied in the determination of dopamine in pharmaceutical preparation with success.
Adapting Mini‐Mental State Examination for dementia screening among illiterate or minimally educated elderly Chinese
Authors: Xu Gelin , Meyer John Stirling , Huang Yuangui , Du Fang , Chowdhury Munir , Quach Minh 
Published: June 2003

AbstractBackgroundIlliteracy is prevalent among current elderly Chinese. There are few brief cognitive tests in Chinese designed to screen those possibly demented for more detailed evaluation in a clinical setting.ObjectivesThe present study adapted the Mini‐Mental State Examination (MMSE) for screening dementia among illiterate or less educated elderly Chinese.MethodsLiteracy‐dependent items of the MMSE were modified or substituted by equivalent items that are not literacy‐dependment. Some items were modified to provide socio‐cultural compatibility. After developing it, the Chinese adapted MMSE (CAMSE) was administered to 370 elderly outpatients from Xijing hospitals located in Xi'an, China, 93 of whom were found to be demented and 277 non‐demented. Sensitivities and specificities for detecting dementia were evaluated by adjusting for different CAMSE cut‐off points. The optimal cut‐off points of 22 for literates and 20 for illiterates yielded a sensitivity of 83.87% and a specificity of 84.48%. Corresponding positive predictive value (PPV) was 0.65, and negative predictive value (NPV) was 0.94. The impact of literacy on CAMSE and individual test items was also evaluated. Illiterate subjects got a higher CAMSE total score than literate subjects (p < 0.05). Only one out of 12 test items, serial sevens, was negatively influenced by illiteracy (p < 0.01). After an interval of 4–6 weeks, 32 randomly selected subjects were retested with CAMSE. The test–retest reliability for total scores was 0.75 (p < 0.01).ConclusionsResults suggest that in the socio‐cultural context for Chinese, irrespective of their literacy skills, CAMSE proved feasible for use in clinical settings for dementia screening. Copyright © 2003 John Wiley & Sons, Ltd.
Estimation of sons' intergenerational earnings mobility in the presence of censoring
Authors: Minicozzi Alexandra L. 
Published: June 2003

AbstractBased on intergenerational data from the Panel Study of Income Dynamics, I provide estimates of income mobility across generations for men. Special attention is paid to issues of censoring caused by a son's unemployment. Employing non‐parametric bounds estimates, I illustrate that previous income mobility estimates rely heavily on (unjustified) assumptions of exogenous selection. Assuming a son's potential income is instead a function of his reason for unemployment and work history, I re‐estimate mobility. Allowing for sampling variability, the range of feasible slopes consistent with these modified bounds restrictions is 0.27 to 0.55. Copyright © 2002 John Wiley & Sons, Ltd.
Identification and estimation of a class of household production models
Authors: Kerkhofs Marcel , Kooreman Peter 
Published: June 2003

AbstractWe consider a class of household production models characterized by a dichotomy property. In these models the amount of time spent on household production does not depend on the household utility function, conditional on household members having a paid job. We analyse the (non‐parametric) identifiability of the production function and the so‐called jointness function (a function describing which part of household production time is counted as pure leisure). It is shown that the models are identified in the two‐adult case, but not in the single‐adult case. We present an empirical application to Swedish time‐allocation data. The estimates satisfy regularity conditions that were violated in previous studies and pass various specification tests. For this data set we find that male and female home production time are q‐substitutes. Copyright © 2003 John Wiley & Sons, Ltd.
Mathematical modeling of gas‐phase biofilter performance
Authors: Jorio Hasnaa , Payre Guy , Heitz Michèle 
Published: June 2003

AbstractIn the present paper, a new mathematical model describing the physical, chemical and biological phenomena involved in the process of contaminant removal in biofilters is developed. In addition to the contaminant, the key components of the present theoretical model are carbon dioxide and oxygen. The model predicts the concentration profile of the key components in the gas phase, the biofilm and the sorption liquid retained in the solid particles composing the filter bed at both steady and transient regimes. The model equations were solved numerically and comparison between theory and experiment showed that the model results for styrene and carbon dioxide concentration profiles were in very good agreement with experimental data for the biofiltration of styrene vapors at steady state. The analysis of oxygen concentration profile in the biofilm predicted by the theoretical model revealed that oxygen limitation does not occur under the operating styrene biodegradation rate in the biofilter. Copyright © 2003 Society of Chemical Industry
Gas phase esterification of acetic acid with ethanol over MoO3 supported on AlPO4 and the effect of modification with phosphomolybdic acid and Ce4+ ions
Authors: Said Abd El‐Aziz A 
Published: June 2003

AbstractA series of AIPO4–MoO3 (APM) systems with various molybdena loadings (5–50) mol %, same modified with phosphomolybdic acid (PMA) and cerium ions, were prepared by an impregnation method and calcined at 400 °C, except for the samples modified with PMA which were calcined at 350 °C for 4 h. The catalysts were characterized by TG/DTG, XRD, IR spectroscopy, N2 adsorption and electrical conductivity measurements. The surface acidity and basicity of the catalysts were determined by adsorption of pyridine and the dehydration–dehydrogenation of isopropyl alcohol. The catalytic esterification of acetic acid with ethanol was carried out in a convention fixed bed reactor. The results clearly revealed that the catalyst with a composition of 10 mol % MoO3 (APM10) was the most active and selective catalyst for the production of ethyl acetate. Moreover, the yield of ethyl acetate increases on addition of PMA into APM10 while it decreases on the addition of Ce4+ ions. These results were correlated with structure, semiconductivity and the acid–base properties of the prepared catalysts. Copyright © 2003 Society of Chemical Industry
Optimization of extraction of bulk enzymes from spent mushroom compost
Authors: Singh Avneesh D , Abdullah Noorlidah , Vikineswary S 
Published: June 2003

AbstractThe profiling of ligninase, hemicellulase and cellulase of Pleurotus sajor‐caju after inoculation of spawn in bags containing sawdust was done at monthly intervals for a period of 6 months. Xylanase (EC 3.2.1.8) was produced throughout the 6 months studied with the productivity range from 5.60 to 7.51 U g−1. Cellulase (EC 3.2.1.4) and β‐glucosidase (EC 3.2.1.21) productivities were highest at 4 months, producing 3.31 U g−1 and 121.13 U g−1 respectively. Laccase (EC 1.10.3.2) productivity was highest at 2 months with a value of 7.59 U g−1. Lignin peroxidase (EC 1.11.1.14) productivity was highest at 5 months with a value of 206.20 U g−1. Total soluble proteins were highest at 4 months with a value of 0.139 mg cm−3. The profiling of lignin peroxidase in 5‐month‐old spent mushroom compost was monitored over a period of 10 months. It was observed that lignin peroxidase was produced throughout the period but productivity was variable. The average lignin peroxidase productivity ranged from 30 to 110 U g−1. The activities of the enzymes extracted in tap water at pH 8.4 were comparable to that extracted in 50 mmol sodium citrate buffer at pH 4.8 and distilled water at pH 5.2 at 4 °C using an incubator shaker at 200 rpm for 18 h. The optimum extraction time was 1 h using an incubator shaker at 4 °C. When an incubator shaker was used, there was no significant difference in the recovery of xylanase, cellulase and laccase at different pH values at 4 °C and 28 °C. No significant difference was observed in the recovery of β‐glucosidase using an incubator shaker at different pH values at 4 °C although the enzyme recovery was slightly higher at pH 8.12, with a value of 29.27 U g−1. The optimum extraction of β‐glucosidase was at pH 4 at room temperature using an incubator shaker. For the lignin peroxidase enzyme, the optimum pH for extraction was 6 at 4 °C and pH 7 at room temperature using an incubator shaker at 200 rpm for 1 h. Homogenization for 8 min at 8000 rpm using tap water at pH 4 had an advantage over the use of the incubator shaker for the extraction as high titers of enzymes were recovered. Copyright © 2003 Society of Chemical Industry
Effect of ring promoter on ionic mass transfer in a fluidized bed
Authors: Venkateswarlu P , Rao VSVSN , Srinivasa Krishna N , Subba Rao D 
Published: June 2003

AbstractMass transfer data were obtained at the wall of a batch fluidized bed in the presence of a ring promoter used for the reduction of ferricyanide ion. The ring promoter was a copper rod on which rings of uniform size were fixed at equal distances. In these studies, the cross‐sectional diameter of the ring, the spacing between the rings, the particle size and the void fraction were varied and the limiting current data were measured. It was observed that the mass transfer coefficients were augmented with increased particle diameter, decreased spacing between the rings, and increased cross‐sectional diameter of the ring. Copyright © 2003 Society of Chemical Industry
Pedotransfer functions for the pool size of slowly mineralizable organic N in sandy arable soils
Authors: Heumann Sabine , Böttcher Jürgen , Springob Günther 
Published: June 2003

AbstractThe major aim of this study was to evaluate how the pool size of slowly mineralizable, ‘old’ soil organic N can be derived from more easily accessible soil and site information via pedotransfer functions (PTF). Besides modeling, this pool size might be of great importance for the identification of soils with high mineralization potential in drinking‐water catchments. From long‐term laboratory incubations (ca. 200 days) at 35 °C, the pool sizes of easily mineralizable organic N (Nfast), mainly in fresh residues, and slowly mineralizable, ‘old’ soil organic N (Nslow) as well as their first‐order rate coefficients were obtained. 90 sandy arable soils from NW Germany served to derive PTFs for Nslow that were evaluated using another 20 soils from the same region. Information on former land‐use and soil type was obtained from topographical, historical, and soil maps (partly from 1780). Pool size Nslow very strongly depends on soil type and former land‐use. Mean pool sizes of Nslow were much lower in old arable lowland (105 mg N kg–1) than upland soils (175 mg N kg–1) possibly due to lower clay contents. Within lowlands, mean pool sizes in former grassland soils (245 mg N kg–1) were 2 to 3 times larger than in old arable soils due to accumulation of mineralizable N. In contrast, mean pool sizes of Nslow were lowest in recently cleared, former heath‐ and woodland (31 mg N kg–1) as a result of the input of hardly decomposable organic matter. Neither N nor C in the light fraction (density < 1.8 g cm–3) was adequate to derive pool size Nslow in the studied soils (r2 < 0.03). Instead, Nslow can be accurately (r2 = 0.55 – 0.83) derived from one or two basic soil characteristics (e.g. organic C, total N, C : N, mineral fraction < 20 μm), provided that sites were grouped by former land‐use. Field mineralization from Nslow during winter (independent data set) can be predicted as well on the basis of Nslow‐values calculated from PTFs that were derived after grouping the soils by former land‐use (r2 = 0.51***). In contrast, using the PTF without soil grouping strongly reduced the reliability (r2 = 0.16).