bluuebunny/crossref_metadata_2025_split huggingface dataset:
Explicit limit equilibrium solution for slope stability
Authors: Zhu D. Y. , Lee C. F. 
Published: November 2002

AbstractConventional methods of slices used for slope stability analysis satisfying all equilibrium conditions involves generally solving two highly non‐linear equations with respect to two unknowns, i.e. the factor of safety and the associated scaling parameter. To solve these two equations, complicated numerical iterations are required with non‐convergence occasionally occurring. This paper presents an alternative procedure to derive the three equilibrium equations (horizontal and vertical forces equations and moment equation) based on an assumption regarding the normal stress distribution along the slip surface. Combination of these equations results in a single cubic equation in terms of the factor of safety, which is explicitly solved. Theoretical testing demonstrates that the proposed method yields a factor of safety in reasonable agreement with a closed‐form solution based on the theory of plasticity. Example studies show that the difference in values of factor of safety between the proposed method, the Spencer method and the Morgenstern–Price method is within 5%. Application of the proposed method to practical slope engineering problems is rather straightforward, but its solution is of the same precision as those given by the conventional rigorous methods of slices since it is still within the rigorous context. Copyright © 2002 John Wiley & Sons, Ltd.
1H‐NMR assay of papaverine hydrochloride and formulations
Authors: Aboutabl Elsayed A. , EI‐Azzouny Aida A. , Afifi Manal S. 
Published: November 2002

AbstractA precise and specific 1H‐NMR method has been developed for the assay of papaverine hydrochloride (1) as a bulk drug, as well as in tablet and injection dosage forms. The assay depends upon the integration of the 12 protons of the four methoxy groups of 1 relative to that of the three methyl protons of acetanilide (internal standard). In addition to the accurate quantitative determination of 1, the method provides a specific means of identifying 1 as well as detecting other alkaloids or impurities. Copyright © 2002 John Wiley & Sons, Ltd.
Solid‐phase extraction and reversed‐phase high‐performance liquid chromatography of the five major alkaloids in Narcissus confusus
Authors: López Susana , Bastida Jaume , Viladomat Francesc , Codina Carles 
Published: November 2002

AbstractA novel, fast and precise method, combining solid‐phase extraction and reversed‐phase high‐performance liquid chromatography is described for the quantitative determination of five alkaloids (galanthamine, N‐formylnorgalanthamine, haemanthamine, homolycorine and tazettine/pretazettine) from bulbs of wild Narcissus confusus, a high galanthamine‐containing plant species growing in the Iberian Peninsula. Copyright © 2002 John Wiley & Sons, Ltd.
Application of centrifugal force to the extraction and separation of parasorboside and gerberin from Gerbera hybrida
Authors: Yrjönen Teijo , Vuorela Pia , Klika Karel D. , Pihlaja Kalevi , Teeri Teemu H. , Vuorela Heikki 
Published: November 2002

AbstractA method for the separation of parasorboside and gerberin from the ornamental plant Gerbera hybrida (Asteraceae) has been developed. The two closely related glucosides were extracted using an Extrachrom® instrument, a prototype multi‐functional separation tool equipped with an extraction chamber. The rotation planar extraction procedure was compared with that of a medium pressure solid–liquid extraction system. The resulting extracts were pre‐purified using rotation planar chromatography and the results compared with those obtained using medium pressure liquid chromatography with silica gel as the stationary phase and a mobile phase of methanol:ethyl acetate:tetrahydrofuran at selectivity point Ps = 111 with 1% formic acid as modifier. The title compounds were isolated from the purified extracts by TLC and their structures confirmed by 1H‐ and 13C‐NMR spectroscopy. Copyright © 2002 John Wiley & Sons, Ltd.
Gain Scheduled LPV H∞ Control Based on LMI Approach for a Robotic Manipulator
Authors: Yu Zhongwei , Chen Huitang , Woo Peng‐yung 
Published: November 2002

AbstractA new approach to the design of a gain scheduled linear parameter‐varying
(LPV) H∞ controller, which places the closed‐loop
poles in the region that satisfies the specified dynamic response, for an
n‐joint rigid robotic manipulator, is presented. The nonlinear time‐varying
robotic manipulator is modeled to be a LPV system with a convex polytopic
structure with the use of the LPV convex decomposition technique in a filter
introduced. State feedback controllers, which satisfy the H∞
performance and the closed‐loop pole‐placement requirements, for each
vertex of the convex polyhedron parameter space, are designed with the use
of the linear matrix inequality (LMI) approach. Based on these designed feedback
controllers for each vertex, a LPV controller with a smaller on‐line computation
load and a convex polytopic structure is synthesized. Simulation and experiment
results verify that the robotic manipulator with the LPV controller always
has a good dynamic performance along with the variations of the joint positions.
© 2002 Wiley Periodicals, Inc.
On the swapping algorithm
Authors: Madras Neal , Zheng Zhongrong 
Published: November 2002

AbstractThe Metropolis‐coupled Markov chain method (or “Swapping Algorithm”) is an empirically successful hybrid Monte Carlo algorithm. It alternates between standard transitions on parallel versions of the system at different parameter values, and swapping two versions. We prove rapid mixing for two bimodal examples, including the mean‐field Ising model. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 22: 66–97, 2002
Fetal activity following stimulation of the mother's abdomen, feet, and hands
Authors: Diego Miguel A. , Dieter John N. I. , Field Tiffany , Lecanuet Jean Pierre , Hernandez‐Reif Maria , Beutler Julia , Largie Shay , Redzepi Mercedes , Salman Fawwaz A. 
Published: November 2002

AbstractFetal activity during midgestation (M age=19.8 weeks) was studied in response to vibratory stimulation of the mother's abdomen (at the height of the fetal head), foot massage, hand massage, or control condition (no stimulation). Consistent with previous research conducted during midgestation, the fetuses of mothers who received two trials of 3‐sec, 60‐Hz vibratory stimulation did not show changes in movement. In contrast, the fetuses of mothers who received a 3‐min foot massage showed greater movement than the control fetuses. However, stimulating the mother's hand (another highly innervated area) did not increase fetal activity. By late gestation (M age=35.4 weeks), vibratory stimulation resulted in increased fetal activity. These findings replicate previous research indicating that vibratory stimulation to the mother's abdomen does not elicit fetal activity until later in gestation. Furthermore, our findings indicate that stimulating the mothers' feet, but not the hands, can evoke fetal activity in midgestation. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 41: 396–406, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10071
First‐generation teeth in nonmammalian lineages: Evidence for a conserved ancestral character?
Authors: Sire Jean‐Yves , Davit‐Beal Tiphaine , Delgado Sidney , Van Der Heyden Christine , Huysseune Ann 
Published: November 2002

AbstractThe present study focuses on the main characteristics of first‐generation teeth (i.e., the first teeth of the dentition to develop in a given position and to become functional) in representatives of the major lineages of nonmammalian vertebrates (chondrichthyans, actinopterygians, and sarcopterygians: dipnoans, urodeles, squamates, and crocodiles). Comparative investigations on the LM and TEM level reveal the existence of two major types of first‐generation teeth. One type (generalized Type 1) is characterized by its small size, conical shape, atubular dentine, and small pulp cavity without capillaries and blood vessels. This type is found in actinopterygians, dipnoans, and urodeles and coincides with the occurrence of short embryonic periods in these species. The other type assembles a variety of first‐generation teeth, which have in common that they represent miniature versions of adult teeth. They are generally larger than the first type, have more complex shapes, tubular dentine, and a large pulp cavity containing blood vessels. These teeth are found in chondrichtyans, squamates, and crocodiles, taxa which all share an extended embryonic period. The presence in certain taxa of a particular type of first‐generation teeth is neither linked to their phylogenetic relationships nor to adult body size or tooth structure, but relates to the duration of embryonic development. Given that the plesiomorphic state in vertebrates is a short embryonic development, we consider the generalized Type 1 first‐generation tooth to represent an ancestral character for gnathostomes. We hypothesize that an extended embryonic development leads to the suppression of tooth generations in the development of dentition. These may still be present in the form of rudimentary germs in the embryonic period. In our view, this generalized Type 1 first‐generation teeth has been conserved through evolution because it represents a very economic and efficient way of building small and simple teeth adapted to larval life. The highly adapted adult dentition characteristic for each lineage has been possible only through polyphyodonty. Microsc. Res. Tech. 59:408–434, 2002. © 2002 Wiley‐Liss, Inc.
Constrained Ramsey numbers of graphs
Authors: Jamison Robert E. , Jiang Tao , Ling Alan C. H. 
Published: November 2002

AbstractGiven two graphs G and H, let f(G,H) denote the minimum integer n such that in every coloring of the edges of Kn, there is either a copy of G with all edges having the same color or a copy of H with all edges having different colors. We show that f(G,H) is finite iff G is a star or H is acyclic. If S and T are trees with s and t edges, respectively, we show that 1+s(t−2)/2≤f(S,T)≤(s−1)(t2+3t). Using constructions from design theory, we establish the exact values, lying near (s−1)(t−1), for f(S,T) when S and T are certain paths or star‐like trees. © 2002 Wiley Periodicals, Inc. J Graph Theory 42: 1–16, 2003
Maspin is up‐regulated in premalignant prostate epithelia
Authors: Pierson Christopher R. , McGowen Richard , Grignon David , Sakr Wael , Dey Jyotirmoy , Sheng Shijie 
Published: November 2002

AbstractBACKGROUNDMaspin, a novel serine protease inhibitor, has been shown to inhibit prostate tumor cell motility and invasion in vitro and to inhibit prostate tumor growth and metastasis in vivo. Maspin expression in high‐grade prostate carcinoma (PC) is reduced compared with that in low‐grade PC. Interestingly, however, compared with low‐grade PC, benign secretory prostate epithelial cells express significantly less maspin. This observation appears paradoxical to a putative tumor suppressive role of maspin in prostate carcinogenesis, and this finding issue needs to be clarified.METHODSWe examined maspin expression simultaneously in benign basal cells, benign secretory cells, high‐grade prostate intraepithelial neoplasia (HGPIN), low‐grade PC, and high‐grade PC in 46 radical prostatectomy specimens plus 51 autopsy prostate glands by a combination of immunohistochemistry and in situ hybridization.RESULTSBenign basal cells consistently expressed maspin at a high level. In PC, the loss of basolateral maspin expression coincides with loss of the basal cell layer. Maspin expression in secretory cells, on the other hand, appears to undergo a biphasic differential regulation, i.e., essentially absent in benign secretory cells, dramatically up‐regulated in HGPIN, then progressively down‐regulated through low‐grade PC to high‐grade PC. Maspin expression in PC is inversely correlated with tumor grade. Furthermore, maspin expression in HGPIN is inversely correlated with the Gleason's grade of the adjacent PC.CONCLUSIONSAn up‐regulation of maspin expression precedes, rather than occurs at, the critical transition from premalignant prostate lesion of HGPIN to PC. Our data suggest maspin may mark an important transitional phase and play an important role in the premalignancy of the prostate gland. Prostate 53: 255–262, 2002. © 2002 Wiley‐Liss, Inc.
Four-Hundred Million Years of Conserved Synteny of Human Xp and Xq Genes on Three Tetraodon Chromosomes
Authors: Grützner Frank , Crollius Hugues Roest , Lütjens Götz , Jaillon Olivier , Weissenbach Jean , Ropers Hans-Hilger , Haaf Thomas 
Published: November 2002

The freshwater pufferfish Tetraodon nigroviridis (TNI) has become highly attractive as a compact reference vertebrate genome for gene finding and validation. We have mapped genes, which are more or less evenly spaced on the human chromosomes 9 and X, onTetraodon chromosomes using fluorescence in situ hybridization (FISH), to establish syntenic relationships between Tetraodonand other key vertebrate genomes. PufferFISH revealed that the human X is an orthologous mosaic of three Tetraodon chromosomes. More than 350 million years ago, an ancestral vertebrate autosome shared orthologous Xp and Xq genes with Tetraodon chromosomes 1 and 7. The shuffled order of Xp and Xq orthologs on their syntenic Tetraodon chromosomes can be explained by the prevalence of evolutionary inversions. The Tetraodon 2 orthologous genes are clustered in human Xp11 and represent a recent addition to the eutherian X sex chromosome. The human chromosome 9 and the avian Z sex chromosome show a much lower degree of synteny conservation in the pufferfish than the human X chromosome. We propose that a special selection process during vertebrate evolution has shaped a highly conserved array(s) of X-linked genes long before the X was used as a mammalian sex chromosome and many X chromosomal genes were recruited for reproduction and/or the development of cognitive abilities.[Sequence data reported in this paper have been deposited in GenBank and assigned the following accession no:AJ308098.]
Acute effects of AdvanceTM: a potential reduced exposure product for smokers: Figure 1
Authors: Breland A B , Evans S E , Buchhalter A R , Eissenberg T 
Published: November 2002

Objective:To examine the acute effects of AdvanceTM, a potential reduced exposure product (PREP) for smokers marketed as a means to reduce exposure to toxic gases and tobacco specific nitrosamines.Design, setting, participants:Latin square ordered, three condition, laboratory based, crossover design with 20 smokers of light or ultra-light cigarettes (15 or more cigarettes/day). In each 2.5 hour condition, participants completed an 8-puff smoking bout from their own brand, AdvanceTM, or an unlit cigarette (that is, sham smoking) every 30 minutes for a total of four bouts.Main outcome measures:Subject rated measures of tobacco/nicotine withdrawal; carbon monoxide (CO), and heart rate; plasma nicotine concentrations.Results:Relative to own brand, AdvanceTMproduced similar withdrawal suppression and heart rate increase, lower CO boost, and higher plasma nicotine concentrations.Conclusions:PREPs for smokers need to be evaluated using a comprehensive strategy that includes empirical examination of acute and long term effects. Adequate withdrawal suppression and potentially lower concentrations of CO associated with AdvanceTMuse are positive factors, although higher nicotine concentrations do not constitute “reduced exposure”. Overall, longer exposure periods are necessary to determine carcinogen delivery. PREP evaluation is complex and should be completed objectively.
Evidence for a role for the Dictyostelium Rap1 in cell viability and the response to osmotic stress
Authors: Kang Rujun , Kae Helmut , Ip Hermia , Spiegelman George B. , Weeks Gerald 
Published: November 2002

The Dictyostelium genome contains a single rapA gene,which encodes a Rap1 monomeric G protein. As attempts at generating rapA-null Dictyostelium cells had been unsuccessful,expression of antisense RNA from the rapA gene under control of the folate repressible discoidin promoter was used to reduce cellular levels of the Rap1 protein. As Rap1 levels gradually decreased following antisense rapA RNA induction, growth rate and cell viability also decreased, a result consistent with the idea that rapA is an essential gene.
The Rap1-depleted cells exhibited reduced viability in response to osmotic shock. The accumulation of cGMP in response to 0.4 M sorbitol was reduced after rapA antisense RNA induction and was enhanced in cells expressing the constitutively activated Rap1(G12V) protein, suggesting a role for Rap1 in the generation of cGMP. Dictyostelium Rap1 formed a complex with the Ras-binding domain of RalGDS only when it was in a GTP-bound state. This assay was used to demonstrate that activation of Rap1 in response to 0.4 M sorbitol occurred with initial kinetics similar to those observed for the accumulation of cGMP. Furthermore, the addition of 2 mM EDTA to osmotically shocked cells, a treatment that enhances cGMP accumulation, also enhanced Rap1 activation. These results suggest a direct role for Rap1 in the activation of guanylyl cyclase during the response to hyperosmotic conditions. Rap1 was also activated in response to low temperature but not in response to low osmolarity or high temperature.
The impact of various potential‐vorticity anomalies on multiple frontal cyclogenesis events
Authors: Zhang Da‐Lin , Cheng William Y. Y. , Gyakum John R. 
Published: November 2002

AbstractThe influences of various potential vorticity (PV) anomalies on multiple frontal cyclogenesis events are examined using 60 h simulations of a family of six frontal cyclones that developed over the western Atlantic between 0000 UTC 13 March and 1200 UTC 15 March 1992. The cyclogenesis events are characterized by pronounced low‐level baroclinicity along a large‐scale cold front moving over the warm ocean and by multiple propagating perturbations in the two PV rings on the cyclonic‐shear side of an upper‐level jet stream. It is found that the tracks of the frontal cyclones follow closely the distribution of the PV rings, whereas the cyclogenesis occurs in the cold‐frontal zone, and in close proximity to the propagating PV perturbations in the central portion of an upper‐level parent trough. A piecewise PV inversion reveals that the low‐level thermal advection (or the bottom thermal anomaly) contributes the most to the depths of two major frontal cyclones, followed by latent‐heat release and the upper‐level PV anomalies, whereas the opposite order is true for the remaining four weaker frontal cyclones.A series of sensitivity experiments is performed to test the impact of removing the upper‐level PV anomalies individually, or collectively, on the development of a major frontal cyclone (MFC) as an initial‐value problem. It is found that the MFC genesis and its final intensity depend on how much its track departs from the upper‐level PV perturbations. Removing a PV anomaly associated with a major short‐wave trough delays the MFC genesis by 18 h and weakens its final depth by 13 hPa. The largest departure occurs when two upstream PV anomalies are removed collectively, delaying the MFC genesis by 36 h and weakening its final depth by 21 hPa. It appears that the MFC genesis in the first 36 h depends more on the PV anomalies in an inner PV ring, whereas its subsequent development depends more on the PV reservoir in an outer PV ring.It is shown that most of the frontal cyclones can still develop in the absence of diabatic heating, indicating the important role of dry dynamics in controlling the multiple frontal cyclogenesis events. However, the ‘dry’ MFC fails to form a closed isobar when the trough‐related PV anomaly is removed. The associated PV inversion and sensitivity simulation results suggest that even though the low‐level thermal advection plays an important role in deepening the frontal cyclones, it is the upper‐level PV anomalies that provide the necessary forcing for its amplification and the frontal cyclogenesis.It is concluded that the upper‐level propagating multiple PV anomalies play a major role in triggering, but a secondary role in determining the final depth of the multiple frontal cyclones. It is the subsequent growth of the bottom thermal anomaly that accounts for most of the final depth of the frontal cyclones. Copyright © 2002 Royal Meteorological Society
Two‐dimensional simulation of orographic effects on mesoscale boundary‐layer convection
Authors: Tian Wen‐Shou , Parker Douglas J. 
Published: November 2002

AbstractIn this paper, orographic effects on mesoscale boundary‐layer convection are studied through a series of idealized numerical experiments. It is found that hills tend to weaken convective activity at their summits under higher background winds, whilst strong updraughts can be observed at the summits, or slightly downwind of the peaks, under light‐wind conditions; these can be associated with so‐called convective cores. When the background winds are strong, the effects of the hill length on the results are only significant when the height of the hill reaches 500 m. The combined effect of a sensible‐heating maximum on the hill summit and baroclinic tendencies due to the elevated heating is a tendency to produce a convective core under reasonably light‐wind conditions. Under higher‐wind conditions, the strong ascents and descents on both sides of the hill, as well as the lee‐wave dynamics, seem to pose a more important impact on the convective features than the thermal forcing of the hill. A Richardson‐number balance has been proposed to explain these two kinds of response. Finally, under stronger‐wind conditions, the convective available potential energy (CAPE) is small at the summit and reaches its maximum value in the lee of the hill while, under light‐wind conditions, the air parcels at the summit have more buoyancy and the CAPE downwind of the top of the hill is slightly larger than that elsewhere. Copyright © 2002 Royal Meteorological Society
A climatology of mesoscale convective systems over Europe using satellite infrared imagery. I: Methodology
Authors: Morel C. , Senesi S. 
Published: November 2002

AbstractAn automated method aimed at producing a significant European mesoscale convective system (MCS) climatology is presented. It uses Meteosat infrared window channel images and is composed of two main tools: an automated cloud‐shield tracking method and a robust method of discriminating between convective and nonconvective cloud shields.The automated cloud‐tracking method defines cloud systems as connected sets of pixels, named ‘cells’, after temperature and area thresholding and it is based on the overlapping between cells in successive images. It handles splits and merges of cells and takes cell movement into account. It has three parameters: the temperature and area thresholds and a minimum overlapping threshold. It is concluded that it performs a correct tracking at any temperature threshold between −30°C and −55°C and for an area threshold greater than 1000 km2, so that it allows the tracking of MCSs during most of their life cycle.The automated discrimination between convective and non‐convective cloud shields uses a discrimination parameter based on brightness‐temperature gradients on the edges of cells, because strong values of this gradient are observed at the beginning of the life cycle of MCSs when cold anvils develop. A seasonal study, and the sensitivity of the method to the temperature threshold, are presented. The method shows significant quality during the entire warm season (from April to September): it correctly discriminates 80% of MCSs and more than 90% of the most electrically active ones, while showing a low false‐alarm rate around 8%; therefore the method seems to be useful for climatological purposes. Copyright © 2002 Royal Meteorological Society