bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite element approximation on quadrilateral meshes
Authors: Arnold Douglas N. , Boffi Daniele , Falk Richard S. , Gastaldi Lucia 
Published: August 2002

AbstractQuadrilateral finite elements are generally constructed by starting from a given finite dimensional space of polynomials V̂ on the unit reference square K̂. The elements of V̂ are then transformed by using the bilinear isomorphisms FK which map K̂ to each convex quadrilateral element K. It has been recently proven that a necessary and sufficient condition for approximation of order r+1 in L2 and r in H1 is that V̂ contains the space Qr of all polynomial functions of degree r separately in each variable. In this paper several numerical experiments are presented which confirm the theory. The tests are taken from various examples of applications: the Laplace operator, the Stokes problem and an eigenvalue problem arising in fluid‐structure interaction modelling. Copyright © 2001 John Wiley & Sons, Ltd.
Ergodicity for the Navier‐Stokes equation with degenerate random forcing: Finite‐dimensional approximation
Authors: E Weinan , Mattingly Jonathan C. 
Published: August 2002

AbstractWe study Galerkin truncations of the two‐dimensional Navier‐Stokes equation under degenerate, large‐scale, stochastic forcing. We identify the minimal set of modes that has to be forced in order for the system to be ergodic. Our results rely heavily on the structure of the nonlinearity. © 2001 John Wiley & Sons, Inc.
Assessing social cognitive skills in aggressive children from a developmental perspective: the social cognitive skills test
Authors: van Manen Teun G. , Prins Pier J. M. , Emmelkamp Paul M. G. 
Published: August 2002

AbstractThe development and psychometric evaluation of the Social Cognitive Skills Test (SCST) for (aggressive) children is described. The SCST is based on the structural developmental approach of social cognition by Selman and Byrne (1974) and consists of six short stories with corresponding pictures. Each story measures eight social cognitive skills. The SCST takes into account the developmental level of the (aggressive) child and his/her social information processing deficits. Three studies were conducted to explore the psychometric qualities of the SCST. Study 1 (n = 47) supported the notion that (a) the SCST discriminates between aggressive and non‐aggressive children, and that (b) there is a descending trend in SCST‐scores as social cognitive skills increase in complexity. Study 2 (n = 115) confirmed the findings of Study 1 and further revealed (a) no differences in the scores on the SCST between reactive and proactive aggressive children, and (b) a positive association between chronological age and social cognitive level of the aggressive and non‐aggressive children. Finally, Study 3 (n = 48) confirmed the previous findings and found that aggressive children have difficulty verbalizing their thoughts, feelings and intentions and show a lack in non‐verbal social understanding. Copyright © 2001 John Wiley & Sons, Ltd.
Useful network transformations and reconfigurable analogue filters using the complementary transformation
Authors: Onete Cristian E. 
Published: August 2002

AbstractIn this paper it is shown that some of the useful network transformations, such as low pass (LP) to band pass (BP), LP to high pass (HP) and HP to BP can be obtained by means of the complementary transformation (CT). Furthermore, because the CT is a topological one (i.e. the component values remain unchanged, but their position within the circuit changes), it is suitable to realize reconfigurable analogue filter arrays. As an example, a full list of the obtainable GIC‐based filters, along with their design equations, is also presented. Copyright © 2001 John Wiley & Sons, Ltd.
Spatial distribution patterns of interphase centromeres during retinoic acid‐induced differentiation of promyelocytic leukemia cells
Authors: Beil Michael , Dürschmied Daniel , Paschke Stephan , Schreiner Bettina , Nolte Ulla , Bruel Arlette , Irinopoulou Theano 
Published: August 2002

AbstractBackgroundThe pericentromeric heterochromatin is an important element for the regulation of gene silencing. Its spatial distribution during interphase appears to be cell‐type specific. This study analyzes three‐dimensional (3D) centromere distribution patterns during cellular differentiation along the neutrophil pathway.MethodsDifferentiation of the promyelocytic leukemia cell line NB4 was induced by retinoic acid. Centromeres in interphase nuclei were visualized by immunofluorescence staining of centromere‐associated proteins with CREST serum. 3D images of nuclei were obtained by confocal microscopy. Automated methods for the segmentation of point‐like objects in 3D images were implemented to detect the position of centromeres. Features of centromere localization patterns were determined by constructing the minimal spanning tree of the centromere distribution.ResultsIn differentiated NB4 cells, the number of centromere conglomerates (chromocenters) was decreased and the distance between chromocenters was increased as compared with untreated controls. The nuclear volume did not differ between the two groups.ConclusionsThe measured rearrangement of centromeres indicates a progressive clustering of heterochromatin and a global remodeling of interphase chromosome territories during differentiation of NB4 cells. The developed methods for the analysis of 3D centromere distribution patterns provide the opportunity for a fast and objective analysis of heterochromatin remodeling. Cytometry 47:217–225, 2002. © 2002 Wiley‐Liss, Inc.
Imaging technique implemented in CellTracks system
Authors: Tibbe Arjan G.J. , de Grooth Bart G. , Greve Jan , Dolan Gerald J. , Terstappen Leon W.M.M. 
Published: August 2002

AbstractBackgroundWe developed the CellTracks cell analysis system that, similar to flow cytometry, yields multiparameter information by which the cells can be differentiated. We describe the implementation of a laser scanning imaging method in the system. Image analysis of the cells improves the specificity of cell classification, especially in cases where the particular cells are found relatively infrequently and one has to discriminate between artifacts and real events.MethodsFluorescent images of immunomagnetically labeled and aligned cells are obtained by passing the cells through a laser focus. The laser focus is smaller than the objects and subsequent frames captured by a regular surveillance CCD camera with a frame grabber board represent different parts of the cells. Complete images of the cells are constructed by shifting each image with respect to each other and adding individual pixel values.ResultsThe power of combining a fluorescent image with multiparametric data is demonstrated by imaging fluorescent and magnetically labeled beads and cells. The image gives additional information about the dye distribution across the objects. Changes in dye distribution as a function of time were observed in leukocytes labeled with the red fluorescent label, Oxazine750, which are imaged at different time intervals.ConclusionsAn imaging technique implemented in the CellTracks system provides high‐resolution fluorescent images of events previously identified by the system. The images of the fluorescent cells enhance the ability to classify rare events. Cytometry 47:248–255, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative FISH analysis on interphase nuclei may improve diagnosis of DNA diploid breast cancers
Authors: Truong Khuong , Vielh Philippe , Guilly Marie‐Nöelle , Klijanienko Jerzy , Sastre‐Garau Xavier , Soussaline Françoise , Dutrillaux Bernard , Malfoy Bernard 
Published: August 2002

AbstractThe detection of DNA aneuploid cells using flow cytometry is an indication for the presence of tumor cells, but when DNA diploid cells are found in 25–33% of the cases, the diagnostic and prognostic significance of DNA ploidy is more limited. We analyzed interphase nuclei after in situ hybridization and using image cytometry on 50 breast tumors with diploid DNA content to investigate whether early chromosome rearrangements were detectable and if their occurrence was clinically significant. Imbalances between the two arms of chromosome 1 were found in 55% of the cases and values ranged from 1.5–3.0. Comparison with histological data showed that Grade I tumors mainly have imbalances (67%) and that Grade III tumors were mainly without the imbalance (67%), whereas Grade II tumors were intermediate (50% imbalance). These data suggest that the diagnosis of DNA diploid cases may be improved by using interphase FISH. In addition, the data also indicates that early breast tumors may have different genetic origins, which is important in the comprehension of tumor malignancy in early stages, especially for preinvasive lesions. Diagn. Cytopathol. 2002;26:213–216. © 2002 Wiley‐Liss, Inc.
Molecular determinants of opioid analgesia: Modulation of presynaptic calcium channels
Authors: Beedle Aaron M. , Zamponi Gerald W. 
Published: August 2002

AbstractOpioid receptor agonists remain one of the most efficacious classes of analgesic drugs available for clinical use. Although multiple subclasses of opioid receptors have been identified (δ, κ, and μ), most opioid analgesics act at the μ receptor subtype to decrease cAMP formation, activate hyperpolarizing K+ channels, and inhibit Ca2+ channels. Here, we discuss the molecular interactions underlying opioid receptor‐mediated modulation of voltage‐dependent calcium channels. Opioid receptor activation results in binding of the G protein βγ complex to specific structural elements of the presynaptic calcium channel. The modulated calcium channel displays characteristic inhibition and kinetic slowing resulting in reduced Ca2+ influx and diminished release of neurotransmitter. Mounting evidence suggests that desensitization of this opioid response involves regulators of G‐protein signaling (RGS), G‐protein coupled receptor kinases (GRK), and β‐arrestins. Further advances in our understanding of these subcellular events mediating opioid pain relief offer new prospects in the development of improved analgesic agents. Drug Dev. Res. 54:118–128, 2002. © 2002 Wiley‐Liss, Inc.
Role of P2Y11 receptors in hematopoiesis
Authors: Communi Didier , Janssens Rodolphe , Robaye Bernard , Zeelis Natacha , Boeynaems Jean‐Marie 
Published: August 2002

AbstractThe HL‐60 cell line are human promyelocytic leukocytes. They are induced to differentiate into neutrophil‐like cells by various agents including retinoic acid (RA), dimethylsulfoxide, granulocyte‐colony stimulating factor, and cell‐permeable forms of cyclic AMP (cAMP) such as N6, 2′‐O‐dibutyryl cAMP. More recently, extracellular ATP has been reported to induce the differentiation of HL‐60 cells into granulocytes through an increase in the intracellular cAMP concentration. Our Northern blotting experiments have shown that P2Y11 messengers were upregulated, rapidly (1 h) and independently from protein synthesis, after treatment with all the agents inducing granulocytic differentiation. Our pharmacological characterization of the recombinant human P2Y11 receptor has shown that it is the receptor coupled to the cAMP pathway in the HL‐60 cells. The P2Y11 receptor is potently activated by adenosine 5′‐O‐(3‐thiotriphosphate), 2′‐ & 3′‐O‐(4‐benzoyl‐benzoyl)adenosine 5′‐triphosphate, and the ATP derivative AR‐C67085 (2‐propylthio‐β, γ‐dichloromethylene‐D‐ATP), which is a potent inhibitor of ADP‐induced platelet aggregation. The P2Y11 receptor is antagonized by suramin and thioderivatives such as adenosine 5′‐O‐(2‐thiodiphosphate). These data support the conclusion that the effect of ATP on HL‐60 cells differentiation is mediated by the P2Y11 receptor and suggest that this receptor plays an important role in neutrophil maturation. Knock‐out experiments are in progress to evaluate the physiological role of the P2Y11 receptor in murine granulopoiesis. Drug Dev. Res. 52:156–163, 2001. © 2001 Wiley‐Liss, Inc.
Functional and molecular evidence of adenosine A2A receptor in coronary arteriolar dilation to adenosine
Authors: Kuo Lih , Hein Travis W. 
Published: August 2002

AbstractAdenosine is a potent vasodilator implicated in the regulation of coronary microvascular diameter during metabolic stress. However, the specific adenosine receptors and underlying mechanism responsible for the dilation of coronary microvessels to adenosine remains to be elucidated. Thus, pig subepicardial coronary arterioles (<100 μm) were isolated, cannulated, and pressurized without flow for in vitro study. All vessels developed basal tone and dilated concentration‐dependently to adenosine. Disruption of endothelium and inhibition of nitric oxide (NO) synthase by L‐NAME produced identical attenuation of adenosine‐induced dilation. KATP channel inhibitor glibenclamide further reduced the dilation of denuded vessels. cAMP antagonist Rp‐8‐Br‐cAMP blocked vasodilation to forskolin, but failed to inhibit vasodilation to adenosine. Coronary dilation to adenosine was blocked by a selective adenosine A2A receptor antagonist ZM241385, but was not altered by an A1 receptor antagonist, DPCPX. Reverse transcription‐polymerase chain reaction study revealed that A2A receptor mRNA was expressed in microvessels but not in cardiac myocytes; A1 receptor expression was observed only in cardiac myocytes. These results suggest that adenosine‐induced dilation of coronary arterioles is mediated predominantly by A2A receptors. Activation of these receptors elicits vasodilation by endothelial release of NO and by smooth muscle opening of KATP channels in a cAMP‐independent manner. Drug Dev. Res. 52:350–356, 2001. © 2001 Wiley‐Liss, Inc.
Peripheral benzodiazepine receptor binding properties and effects on steroid synthesis of two new phenoxyphenyl‐acetamide derivatives, DAA1097 and DAA1106
Authors: Culty Martine , Silver Paulina , Nakazato Atsuro , Gazouli Maria , Li Hua , Muramatsu Makoto , Okuyama Shigeru , Papadopoulos Vassilios 
Published: August 2002

AbstractThe peripheral benzodiazepine receptor (PBR) is a key element of the steroidogenic pathway in peripheral tissues and the CNS. Two phenoxyphenyl‐acetamide derivatives, DAA1097 and DAA1106, exert anxiolytic effects in mice and displace PBR ligands binding in rat brain. Here we examined their effect on steroidogenesis and performed their pharmacological characterization using MA‐10 Leydig tumor and C6‐2B glioma cells, rat brain mitochondria, and recombinant PBR. DAA1097 activated steroidogenesis similarly to the well‐described PBR ligand PK11195, more efficiently on brain than Leydig cells. By contrast, DAA1106 did not activate steroidogenesis, but partially inhibited the hCG‐induced steroidogenesis. The affinity of [3H]DAA1106 for PBR was similar to that of [3H]PK11195 in MA‐10, C6‐2B cells, and for recombinant PBR, but was 10 times higher in rat brain mitochondria. Competition studies revealed that DAA1097 and DAA1106 displaced [3H]PK11195 binding at nano‐ and picomolar concentrations, respectively, while the IC50 of PK11195 against [3H]DAA1106 was in the micromolar range. These results suggest that: 1) DAA1097 and DAA1106 binding sites on PBR share common domain(s) with that of PK11195, but also contain motif(s) that do not interact efficiently with PK11195; 2) these additional sites are part of the PBR molecule, since similar results are found using cells or recombinant PBR; 3) the binding of DAA1097 to PBR induce changes in the receptor similar to that triggered by PK11195, allowing steroidogenesis activation; 4) the fact that DAA1106 does not activate steroidogenesis despite its high affinity for PBR suggests that its binding on PBR leads to conformational changes that do not permit or antagonize PBR steroidogenic function. In conclusion, DAA1097 and DAA1106 represent new, sensitive probes for PBR detection, similar in structure but with opposite effects on steroidogenesis. Thus, an extensive study of their respective binding sites should shed some new light on the structure/function relationship of PBR. Drug Dev. Res. 52:475–484, 2001. © 2001 Wiley‐Liss, Inc.
Effects of ectopias and their cortical location on several measures of learning in BXSB mice
Authors: Hyde Lynn A. , Hoplight Blair J. , Harding Shannon , Sherman Gordon F. , Mobraaten L.E. , Denenberg Victor H. 
Published: August 2002

AbstractAbout half of BXSB/MpJ‐ Yaa mice have ectopias, which are misplaced clusters of neurons located in layer I of cortex. This study replicated several previous findings showing that there are learning differences between mice with ectopias and those without. In addition, we had sufficient numbers of ectopic mice to investigate if ectopics learned differently depending on the cortical location of the ectopia(s). Mice with at least one ectopia located in prefrontal cortex were initially impaired in learning the Morris maze, as well as relearning the Lashley maze when it was inverted, but learned better in the radial‐arm maze when compared to ectopic mice with ectopias located in nonprefrontal regions of cortex. Mice with at least one ectopia in motor cortex learned the Lashley maze better than mice with ectopias located outside motor cortex. In sum, the cortical location of the ectopia(s) affected learning performance in certain tasks within the ectopic group, but regardless of the cortical location of the ectopia(s), ectopics still learned differently than nonectopics in several tasks. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 286–300, 2001
Age‐related changes in paternal responses of gerbils parallel changes in their testosterone concentrations
Authors: Clark Mertice M. , Galef Bennett G. 
Published: August 2002

AbstractResults of previous studies in our laboratory have shown that testosterone (T) inhibits parental response in adult male Mongolian gerbils. Here, we examined developmental changes in parental responses of male gerbils before, during, and after a naturally occurring surge in T that peaks on Day 75 postpartum. On the hypothesis that T inhibits parental response in male gerbils, we predicted that (a) 75‐day‐old male gerbils would be less responsive to neonates than would either younger or older male gerbils, and (b) young male gerbils whose T titers were rising as the litters that they were helping to rear matured would show a decrease over days in parental effort relative to older male gerbils whose T titers were falling as the litters that they were helping to rear matured. Both predictions were confirmed, providing evidence consistent with the view that naturally occurring, developmental changes in circulating concentrations of T play a role in age‐related changes in the level of parental response of male Mongolian gerbils. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 179–187, 2001
Inhibition of cell proliferation in the embryonic myocardium by A1 adenosine receptor activation
Authors: Zhao Zhiyong , Rivkees Scott A. 
Published: August 2002

AbstractA1 adenosine receptors (A1ARs) are expressed in the embryonic heart and influence cardiac function at early developmental stages. To test if A1ARs also affect cardiac structural development, we examined the effects of A1AR activation on heart formation. When pregnant mice were treated with the A1AR agonist, N6‐cyclopentyladenosine (CPA), fetuses showed marked reduction of ventricular size and manifested features of heart failure. Suggesting that these findings represent direct effects on embryos, CPA treatment of cultured whole murine embryos resulted in cardiac hypoplasia. When rates of cell division and cell death in the heart were examined, we found decreases in cardiac cell proliferation following A1AR activation. In contrast, no changes in numbers or distribution of apoptotic cells were seen. Collectively, these data show that A1AR activation inhibits cardiac cell proliferation and can lead to cardiac hypoplasia. These data identify adenosine as a potential regulator of cardiac cell division during early development. © 2001 Wiley‐Liss, Inc.
Effects of middle‐level static magnetic field on metabolic activity of mitochondria
Authors: Yamashita Kazuhiko , Saito Masao 
Published: August 2002

AbstractThis study intends to clarify the effect of a static magnetic field on cellular activities. It is concerned with the metabolic activity of mitochondria from the viewpoint of their energy level. As a preliminary examination, the time required to render the cells to the low‐energy state (G0/G1 phase of the cell cycle) and to reduce their energy level was examined by maintaining the cells in medium with low‐density fetal bovine serum. Then, we examined the effect of the magnetic field on mitochondrial energy activity from the viewpoint of cell metabolism estimated by the MTT assay. We also examined the cell respiration, expecting that the mitochondrial energy activity level would be reflected in the respiration. The magnetic field was kept at 100 mT, with 0 mT as the control. The results of the MTT assay indicated that the mitochondrial energy activity was enhanced by a factor of 1.5. We found that the cell respiration was increased by a factor of 1.3 on exposure to the magnetic field. The t‐test showed the difference to be statistically significant. It is thus concluded that mitochondrial energy activity is enhanced in the G0/G1 phase of the cell cycle by exposure to a magnetic field. On the other hand, we also found that the mitochondrial energy cycle period is little affected. © 2001 Scripta Technica, Electr Eng Jpn, 137(1): 36–41, 2001
Dictyostelium discoideum plasmid containing an AP‐endonuclease upstream sequence: Bleomycin induction of a luciferase reporter
Authors: Ling Angela Z. , Guyer Robert B. , Deering Reginald A. 
Published: August 2002

AbstractA sequence of 1624 bp 5′ to the apurinic/apyrimidinic (AP) endonuclease structural gene of Dictyostelium discoideum (APEA) has been inserted upstream of the luciferase reporter gene in pVTL2, an autonomously replicating nuclear plasmid in this organism. Cells transformed with this plasmid, designated pVTL‐AL, displayed strong luciferase induction during treatment with the DNA‐damaging agent bleomycin. For example, a luciferase activity of 45‐fold above the constitutive level was observed for 20 hours of growth in axenic medium with 0.002 U/mL of bleomycin. The response was bleomycin concentration‐dependent. Cell survival was greater than 90% for all treatments. The level of luciferase expression was highly dependent on the cell growth conditions, with the greatest induction observed for stationary phase axenically‐grown cells. This effect may be related to a variation of plasmid copy number with growth conditions. Environ. Mol. Mutagen. 38:244–247, 2001. © 2001 Wiley‐Liss, Inc.
Leukemia clusters in upstate New York: how adding covariates changes the story
Authors: Ahrens Christina , Altman Naomi , Casella George , Eaton Malaika , Hwang J. T. Gene , Staudenmayer John , Stefanescu Catalina 
Published: August 2002

AbstractThe 1978–1982 New York State TCE / Leukemia dataset is often used to test new cluster detection methodologies. We augment that dataset with demographic covariates from the 1980 census and find evidence that the relation between several of the TCE wastesites and elevated leukemia rates is probably confounded by the population's age and employment characteristics. This demonstrates a problem that is often mentioned, but seldom touched in detail–clustering can be related to covariates not directly related to the risks of interest. Copyright © 2001 John Wiley & Sons, Ltd.