bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimum independent dominating sets of random cubic graphs
Authors: Duckworth W. , Wormald N. C.
Published: October 2002

We present a heuristic for finding a small independent dominating set 𝒟 of cubic graphs. We analyze the performance of this heuristic, which is a random greedy algorithm, on random cubic graphs using differential equations, and obtain an upper bound on the expected size of 𝒟. A corresponding lower bound is derived by means of a direct expectation argument. We prove that 𝒟 asymptotically almost surely satisfies 0.2641n ≤ |𝒟| ≤ 0.27942n. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 147–161, 2002
Largest planar matching in random bipartite graphs
Authors: Kiwi Marcos , Loebl Martin
Published: October 2002

For a distribution 𝒢 over labeled bipartite (multi) graphs G = (W, M, E), |W| = |M| = n, let L(n) denote the size of the largest planar matching of G (here W and M are posets drawn on the plane as two ordered rows of nodes and edges are drawn as straight lines). We study the asymptotic (in n) behavior of L(n) for different distributions 𝒢. Two interesting instances of this problem are Ulam's longest increasing subsequence problem and the longest common subsequence problem. We focus on the case where 𝒢 is the uniform distribution over the k‐regular bipartite graphs on W and M. For k = o(n1/4), we establish that \documentclass{article}\pagestyle{empty}\begin{document}$L(n) \slash \sqrt{kn}$\end{document} tends to 2 in probability when n → ∞. Convergence in mean is also studied. Furthermore, we show that if each of the n2 possible edges between W and M are chosen independently with probability 0 < p < 1, then L(n)/n tends to a constant γp in probability and in mean when n → ∞. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 162–181, 2002
On the critical exponents of random k‐SAT
Authors: Wilson David B.
Published: October 2002

There has been much recent interest in the satisfiability of random Boolean formulas. A random k‐SAT formula is the conjunction of m random clauses, each of which is the disjunction of k literals (a variable or its negation). It is known that when the number of variables n is large, there is a sharp transition from satisfiability to unsatisfiability; in the case of 2‐SAT this happens when m/n → 1, for 3‐SAT the critical ratio is thought to be m/n ≈ 4.2. The sharpness of this transition is characterized by a critical exponent, sometimes called ν = νk (the smaller the value of ν the sharper the transition). Experiments have suggested that ν3 = 1.5 ± 0.1. ν4 = 1.25 ± 0.05, ν5 = 1.1 ± 0.05, ν6 = 1.05 ± 0.05, and heuristics have suggested that νk → 1 as k → ∞. We give here a simple proof that each of these exponents is at least 2 (provided the exponent is well defined). This result holds for each of the three standard ensembles of random k‐SAT formulas: m clauses selected uniformly at random without replacement, m clauses selected uniformly at random with replacement, and each clause selected with probability p independent of the other clauses. We also obtain similar results for q‐colorability and the appearance of a q‐core in a random graph. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 182–195, 2002
Changes in student views of religion and science in a college astronomy course
Authors: Shipman Harry L. , Brickhouse Nancy W. , Dagher Zoubeida , Letts William J.
Published: October 2002

A cautious introduction of the dialogue between science and religion into a college astronomy course provoked diverse reactions from the 340 students in the course. We studied student responses to this curricular intervention with data from the entire class and from a set of interviews of a focus group of 19 students. Approximately half of the students in the class engaged with the issue of science and religion to some extent. There were extraordinarily few negative reactions to this minor intervention. The intellectual paths taken by students who did engage the issue were very diverse; they negotiated their ways across some complex intellectual borders in their own different ways. Some of these pathways led to internal conflict in some students, but this conflict is not necessarily an obstacle to further understanding. Several students developed some rather deep understandings of the interface between science and religion. © 2002 Wiley Periodicals, Inc. Sci Ed 86:526–547, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/sce.10029
Accounting for anomalous oxidation states of silicon at the Si/SiO2 interface
Authors: Cerofolini G. F. , Galati C. , Renna L.
Published: October 2002

The early oxidation stages of hydrogen‐terminated single‐crystalline Si(100) exposed to a diluted N2/N2O atmosphere at 850° C for different durations have been studied by XPS, following the evolution of the Si 2p signal. Evidence is given that the usual analysis, in terms of five pairs of peaks attributed to silicon in oxidation states from 0 to +4, does not account for the observed Si 2p signal. The spectrum is accurately reproduced only by assuming the existence of silicon in bonding configurations different from those usually assumed to occur at the Si/SiO2 interface. Copyright © 2002 John Wiley & Sons, Ltd.
Metrics for maintainability of class inheritance hierarchies
Authors: Sheldon Frederick T. , Jerath Kshamta , Chung Hong
Published: October 2002

Since the proposal for the six object‐oriented metrics by Chidamber and Kemerer (1994), several studies have been conducted to validate their metrics and have discovered some deficiencies. Consequently, many new metrics for object‐oriented systems have been proposed. Among the various measurements of object‐oriented characteristics, we focus on the metrics of class inheritance hierarchies in design and maintenance. As such, we propose two simple and heuristic metrics for the class inheritance hierarchy for the maintenance of object‐oriented software.

In this paper we investigate the work of Chidamber and Kemerer (1994) and Li (1998), and extend their work to apply specifically to the maintenance of a class inheritance hierarchy. In doing so, we suggest new metrics for understandability and modifiability of a class inheritance hierarchy. The main contribution here includes the various comparisons that we have made. We discuss the advantages over Chidamber and Kemerer's (1994) metrics and Henderson‐Sellers's (1996) metrics in the context of maintaining class inheritance hierarchies. Copyright © 2002 John Wiley & Sons, Ltd.
Problem management maturity within corrective maintenance
Authors: Kajko‐Mattsson Mira
Published: October 2002

CM$^3$: Problem Management is a first detailed descriptive problem management process model to be utilized within corrective maintenance. It is the result of a long‐term empirical study of industrial corrective maintenance processes. It has been developed at ABB and evaluated for its industrial relevance within 17 non‐ABB organizations.

Playing the role of a descriptive model, CM$^3$: Problem Management specifies what a problem management process should look like. It also structures it into three maturity levels, Initial, Defined, and Optimal, where each level offers a different grainedness of process visibility.

In this paper, we present the CM$^3$ levels of problem management process maturity within corrective maintenance and match them against the industrial state of practice. Our goal is to establish the current status of problem management maturity using CM$^3$: Problem Management as an evaluation model. Our evaluation results show that the industrial processes today suffice to attend to software problems within corrective maintenance. Very few of them, however, do learn from the past in order to prevent future problems and to improve development or maintenance processes. Copyright © 2002 John Wiley & Sons, Ltd.
The design and implementation of the exported procedure call
Authors: Kendall H. Richard , Freeh Vincent W.
Published: October 2002

This paper describes the exported procedure call, a mechanism that pushes computation out of the operating system kernel and into user space. It supports a simple, secure model for system extensions. An exported procedure call incurs overhead crossing of the user‐kernel boundary, but once in user space, it has greater security and usability and is significantly simpler than an equivalent kernel operation. This paper demonstrates the capabilities of the exported procedure call by discussing two implementations. One is the Modify‐on‐access (Mona) file system and the other is the Magi device interface. Mona and Magi use the exported procedure call in order to safely execute untrusted or complex system extensions. This paper shows that in situations where raw kernel performance is not paramount, the exported procedure call is desirable. Copyright © 2001 John Wiley & Sons, Ltd.
Concluding thoughts
Authors: Dalton Jon C. , McClinton Marguerite
Published: October 2002

The authors offer concluding observations and recommendations on using practical wisdom in professional practice.
Serotonin modulation of cerebral glucose metabolism measured with positron emission tomography (PET) in human subjects
Authors: Smith Gwenn S. , Ma Yilong , Dhawan Vijay , Gunduz Handan , Carbon Maren , Kirshner Maggie , Larson Jennifer , Chaly Thomas , Belakhleff Abdel , Kramer Elisse , Greenwald Blaine , Kane John M. , Laghrissi‐Thode Fouzia , Pollock Bruce G. , Eidelber David
Published: October 2002

To develop a method to measure the dynamic response of the serotonin system in vivo, the effects of intravenously administered citalopram (the most selective of the serotonin reuptake inhibitors) on cerebral glucose metabolism were evaluated. Cerebral glucose metabolism was measured with positron emission tomography (PET) in 14 normal subjects scanned after administration of saline placebo and citalopram administered on 2 separate days. Citalopram administration resulted in a decrease in metabolism in the right anterior cingulate gyrus (BA 24/32), right superior (BA 9) and right middle frontal gyrus (BA 6), right parietal cortex (precuneus), right superior occipital gyrus, left thalamus, and right cerebellum. Increased metabolism was observed in the left superior temporal gyrus and left occipital cortex. Alterations in metabolism by acute citalopram administration involved the heteromodal association cortices that also show metabolic alterations in patients with geriatric depression and overlap with the regions affected by antidepressant treatment. Future studies will evaluate how the acute metabolic response to citalopram relates to the metabolic response after chronic treatment in patients with geriatric depression. Synapse 45:105–112, 2002. © 2002 Wiley‐Liss, Inc.
Direct Measurements of HOx Radicals in the Marine Boundary Layer: Testing the Current Tropospheric Chemistry Mechanism
Authors: Kanaya Yugo , Akimoto Hajime
Published: October 2002

OH and HO2 radicals, atmospheric detergents, and the reservoir thereof, play central roles in tropospheric chemistry. In spite of their importance, we had no choice but to trust their concentrations predicted by modeling studies based on known chemical processes. However, recent direct measurements of these radicals have enabled us to test and revise our knowledge of the processes by comparing the predicted and observed values of the radical concentrations. We developed a laser‐induced fluorescence (LIF) instrument and successfully observed OH and HO2 at three remote islands of Japan (Oki Island, Okinawa Island, and Rishiri Island). At Okinawa Island, the observed daytime level of HO2 agreed closely with the model estimates, suggesting that the photochemistry at Okinawa is well described by the current chemistry mechanism. At Rishiri Island, in contrast, the observed daytime level of HO2 was consistently much lower than the calculated values. We proposed that iodine chemistry, usually not incorporated into the mechanism, is at least partly responsible for the discrepancy in the results. At night, HO2 was detected at levels greater than 1 pptv at all three islands, suggesting the presence of processes in the dark that produce radicals. We showed that ozone reactions with unsaturated hydrocarbons, including monoterpenes, could significantly contribute to radical production. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 199–211, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10019
Conjugated Macrocycles as Active Materials in Nonlinear Optical Processes: Optical Limiting Effect with Phthalocyanines and Related Compounds
Authors: Hanack Michael , Dini Danilo , Barthel Markus , Vagin Sergej
Published: October 2002

An overview of the optical limiting (OL) processes in phthalocyanines and related compounds is presented, particularly a description of the synthesis and relevant optical properties of a series of axially substituted indium(III), titanium(IV), phthalo‐ and naphthalocyanines, and octaarylporphyrazines. Several techniques, such as transient absorption, Z‐scan, and degenerate four‐wave mixing, were used to assess the optical properties and OL performance of the investigated compounds. The versatility of the methods of organic synthesis leads to the achievement of effective systems in terms of OL performance through the appropriate combination and modulation of several structural components. The chemistry of the macrocycles here considered allows the variation of the different chemical features, such as the degree of electronic conjugation of the macrocycle and the nature of the ring substituents, the central atom, and the ligands attached to the central atom. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 129–148, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10024
New Approaches in Radical Carbonylation Chemistry: Fluorous Applications and Designed Tandem Processes by Species‐Hybridization with Anions and Transition Metal Species
Authors: Ryu Ilhyong
Published: October 2002

New approaches in radical carbonylation chemistry are described. We have successfully integrated tin mediated radical carbonylation chemistry into modern fluorous applications and separation techniques. We revealed that radical carbonylation reactions can be performed using fluorous tin mediators, such as fluorous tin hydride and fluorous allyltin reagents. Fine tuning of the reaction conditions resulted in a good efficiency equivalent to conventional tin mediators. The tedious procedure of removing organotin byproducts can be circumvented through the use of fluorous/organic liquid‐liquid extraction or fluorous liquid‐solid phase extraction with fluorous reverse phase silica (FRPS). Also described are newly developed tandem carbonylation reactions that are based on species hybridization approaches. Using a radical/anionic hybrid system based on zinc‐induced one‐electron reduction, we achieved a three‐component coupling reaction consisting of 4‐alkenyl iodides, carbon monoxide, and electron‐deficient alkenes. We observed two types of annulations processes, namely [4 + 1](radical)/[3 + 2](anionic) and [5 + 1](radical)/[3 + 2](anionic), which lead to the production of bicyclo[3.3.0]octanols and bicyclo[3.2.1]octanols, respectively. We found a radical/palladium hybrid system to be useful in the construction of new cyclic systems that incorporate two or three molecules of carbon monoxide. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 249–258, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10026
Determination of chiral ratio of o,p‐DDT and o,p‐DDD pesticides on polysaccharides chiral stationary phases by HPLC under reversed‐phase mode
Authors: Ali Imran , Aboul‐Enein Hassan Y.
Published: October 2002

A simple and reliable HPLC method for the chiral resolution of o,p‐DDT and o,p‐DDD is described. The enantiomeric resolution of o,p‐DDT and o,p‐DDD has been achieved on Chiralpak AD‐R, Chiralcel OD‐R, and Chiralcel OJ‐R chiral stationary phases. The mobile phases used were acetonitrile–water (50:50 [v/v]) and acetonitrile‐2‐propanol (50:50 [v/v]) at a flow rate of 1.0 mL/min. For both pesticides detection was done at 220 nm. The values for o,p‐DDT of α and Rs varied from 1.24 to 2.52 and from 0.80 to 2.47, respectively. The values of α and Rs for o,p‐DDD were 1.26 and 0.60, respectively. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 329–333, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10069
The nebulous art of using wind tunnel aerofoil data for predicting rotor performance
Authors: Tangler James L.
Published: October 2002

The objective of this study was threefold: to evaluate different two‐dimensional S809 aerofoil data sets in the prediction of rotor performance; to compare blade element momentum rotor predicted results with lifting surface, prescribed wake results; and to compare the NASA Ames combined experiment rotor measured data with the two different performance prediction methods. The S809 aerofoil data sets evaluated included those from Delft University of Technology, Ohio State University and Colorado State University. Substantial differences in prediction performance resulted from the different two‐dimensional aerofoil data sets. Predicted performance comparison with NASA Ames data documents shortcomings of these methods and recommends the use of the lifting surface, prescribed wake method over blade element momentum theory for future analytical improvements. Copyright © 2002 John Wiley & Sons, Ltd.
Analyses of the stained glasses of Certosa di Pavia
Authors: Bonizzoni L. , Galli A. , Milazzo M.
Published: October 2002

In the planned restoration of the stained glass windows of the ‘Certosa di Pavia’ presently in progress, systematic elemental energy‐dispersive x‐ray fluorescence (XRF) analysis of glasses has been undertaken on the request of ‘Soprintendenza per i Beni Ambientali e Architettonici’. Analyses of fragments from the first two window‐panes (‘S. Girolamo’ and ‘Presepe’) have been performed. For homogeneous glass samples, quantitative analyses have been obtained by using a secondary XRF set‐up and applying the method of measuring Compton scattering intensity to evaluate self‐absorption corrections. This procedure proved to be effective, as it was checked after comparisons with several standard glass analyses. Also, lateral cross‐sections of each sample have been examined by a 100 µm capillary x‐ray microprobe, so that elements characteristic of glass composition can be discriminated from those due to surface contamination (from lead bindings, for instance). X‐ray microprobe was also a method suited for analyses of layered glasses, as well as spotted small areas or grisaille zones. Copyright © 2002 John Wiley & Sons, Ltd.
Reproductive endocrine patterns in captive female and male red wolves (Canis rufus) assessed by fecal and serum hormone analysis
Authors: Walker S.L. , Waddell W.T. , Goodrowe K.L.
Published: October 2002

Reproductive steroid profiles in female (n=13) and male (n=5) red wolves (Canis rufus) were characterized in fecal samples collected during the breeding season (December—May) and over a 1 year period, respectively. Blood samples from females (n=12) also were collected during the periovulatory period for luteinizing hormone (LH) and steroid analysis. High performance liquid chromatography (HPLC) of fecal extracts determined that estradiol and estrone constituted the major and minor forms, respectively, of fecal estrogen metabolites. Although native progesterone was present, pregnane metabolites predominated as the major forms of fecal progestins. HPLC analysis of fecal extracts from males revealed no native testosterone, but rather the predominance of more polar androgen metabolites. Based on hormone profiles and/or pup production, females were classified as pregnant (n=3), ovulatory‐nonpregnant (n=9), or acyclic (n=3). Longitudinal monitoring of females indicated no pregnancy‐specific differences in concentrations of either fecal progestagen or estrogen metabolites compared to ovulatory‐nonpregnant individuals; however, baseline progestagen concentrations were consistently elevated in acyclic females. There was good correspondence between serum and fecal steroid concentration during the periovulatory period. A rise in serum estrogens preceded the ovulatory LH surge which was then followed by a significant progesterone rise during the luteal phase. In males, changes in fecal androgen metabolite concentrations coincided with photoperiod fluctuations, increasing in late autumn and reaching peak concentrations during mid‐ to late winter just before the start of the breeding season. Collectively, these results serve as a database of ovarian and testicular endocrine events in this species, which can be utilized in population management and application of assisted reproductive technologies. Zoo Biol 21:321–335, 2002. © 2002 Wiley‐Liss, Inc.
Velocity spectra over different terrains
Authors: Al‐Jiboori M. H. , Xu Yumao , Qian Yongfu
Published: October 2002

Power spectra of longitudinal and vertical components of wind velocity have been measured over a variety of terrain types: uniform, inhomogeneous and urban. The result shows that the spectral shapes and peaks of u‐spectra are sensitive to local terrain, while those of w‐spectra are not affected by changes in roughness surface. Copyright © 2003 Royal Meteorological Society.
Intracellular coordination by the ultradian clock.
Authors: Lloyd David , Kippert Fred
Published: October 2002

The time structure of a biological system is at least as intricate as its spatial structure. Whereas we have detailed information about the latter, our understanding of the former is still rudimentary. As techniques for monitoring intracellular processes continuously in single cells become more refined, it becomes increasingly evident that periodic behaviour abounds in all time domains. Timekeeping is essential for synchronization and coordination of intracellular processes. The presence of a temperature‐compensated oscillator provides such a timer. The coupled outputs (epigenetic oscillations) of this ultradian clock constitute a special class of ultradian rhythm. These are undamped and endogenously driven by a device which shows biochemical properties characteristic of transcriptional and translational elements. Energy‐yielding processes, protein turnover, motility, and the timing of the cell division cycle processes, are all controlled by the ultradian clock. Different periods 30 min‐4h characterize different species.
The ERE‐like sequence from the promoter region of the testis specific HSP70‐related gene is not estrogen responsive.
Authors: Krawczyk Zdzislaw , Schmid Wolfgang , Härkönen Pirkko , Wolniczek Piotr
Published: October 2002

The 5′flanking region of the hsp70‐related gene which is specifically expressed in rat and mouse spermatocytes contains the GGTCAnnnCGACC sequence closely resembling the palindromic consensus ERE (estrogen responsive element, GGTCAnnnTGACC). We used a transient expression assay to study whether this ERE‐like sequence can transfer estrogen responsiveness either to heterologous or homologous promoters linked to a reporter CAT gene. We found that the GGTCAnnnCGACC sequence either as an isolated element or in its natural sequence context does not respond to hormone stimulation in MCF‐7 and Fe33 cells. This observation points to the importance of the T‐nucleotide in a right half‐palindrome of ERE for ligand‐dependent activation of transcription.
Relationship between multidrug resistance, hypersensitivity to resistance modifiers and cell volume in Chinese hamster ovary cells.
Authors: Vickers S. E. , Stow M. W. , Warr J. R.
Published: October 2002

We have previously shown that very high levels of hypersensitivity to several resistance modifiers are correlated with increasing multidrug resistance in a series of Chinese hamster ovary cell lines. We have now selected a new member of the series which is an exception to this correlation in that although it is almost twice as multidrug resistant as the cell line from which it was derived, it shows much less hypersensitivity to resistance modifiers.

Level of resistance modifier hypersensitivity correlated with the level of reduction of verapamil accumulation in these cells, and with the density of P‐glycoprotein, but since the selection of this cell line has involved a doubling of cell volume, it was not correlated with total amount of P‐glycoprotein.
Search for functional significance of peptidylarginine deiminase in rat pituitaries: variation during pregnancy and ultrastructural localization in prolactin cells
Authors: Akiyama Kyoichi , Nagata Saburo , Tanaka Shigeyasu , Inoue Kinji , Watanabe Kazutada , Senshu Tatsuo
Published: October 2002

We have studied the expression of peptidylarginine deiminase in rat pituitaries during pregnancy. Both the enzyme protein and its mRNA decreased to low levels after the onset of gestation. Both started to increase markedly during mid pregnancy reaching their maxima on day 18 and declined thereafter. The early phase of variations were accompanied with a progressive decrease in the pituitary prolactin content, an abrupt decrease in the prolactin mRNA content, and a small but significant increase in the serum estrogen. We also performed an immunoelectron microscopic study of the enzyme, and showed its scattered localization in the cytoplasm of prolactin cells.
Cholesterol, triacylglicerols and phospholipids during Xenopus embryo development
Authors: Rizzo Angela M. , Gornati Rosalba , Galli Carlo , Bernardini Giovanni , Berra Bruno
Published: October 2002

Cholesterol, triacylglicerol and phospholipid content was analysed in Xenopus embryos during their early development (from day 1 to day 6). Triacylglicerols decrease significantly during the analysed stages and this can be explained by their use as energy substrate. Cholesterol and phospholipids, on the contrary, remain constant and are probably redistributed inside the embryo. The different phospholipid classes were separated by HPTLC. A constant decrease of PC and a marked increase of PS has been observed. The fatty acid composition of the single phospholipid classes has been analysed.
Plasma membrane transformation: a common response of uterine epithelial cells during the peri‐implantation period
Authors: Murphy Christopher R. , Shaw Timothy J.
Published: October 2002

The plasma membrane of uterine epithelial cells and its changes during early pregnancy are reviewed. The review first examines morphological alterations in rats and mice and laboratory rodents and finds that similar changes in membrane organization accompany the peri‐implantation period: long, thin, regular microvilli are gradually converted into irregular, flattened projections. It is also found however, that in many other species related plasma membrane alterations are seen during early pregnancy. Molecular alterations in the membrane are also examined and although the evidence is so far limited, striking similarities are noted across species. The review also examines some new morphological studies on the alterations in the plasma membrane of uterine epithelial cells during early pregnancy and concludes that a process of plasma membrane transformation may be a common response across species.
Effect of pentoxifylline, a multidrug resistance reversal agent, on haemopoietic stem cell homing.
Authors: Gude R. P. , Chitnis M. P. , Rao S. G. A.
Published: October 2002

This paper investigates the mechanism of mouse haemopoietic stem cell homing into the cytoskeleton depolymerising agent Pentoxifylline was used, and shown to inhibit stem cell homing. The inhibition was reversible after 6 hours. The results obtained suggest that the haemopoietic stem cell homing receptor is anchored to cytoskeletal support intracellularly.
Increased secretion of latent elastase activity following contact between human skin fibroblasts and elastin derived peptides.
Authors: Landeau Jean‐Marie , Pellat Bernard , Hornebeck William
Published: October 2002

Elastin‐derived peptides were previously shown to influence human skin fibroblasts (HSF) chemotaxis and proliferation (Ghuysen et al., 1992). We report here that culturing HSF on κ‐elastin (κE) but not onto fibronectin (FN) enhanced the secretion of latent elastinolytic activity. The proteinase involved was identified as the 72 kDa gelatinase A. Moreover, HSF‐κE as well as HSF‐FN interactions modulated the secretions of Il1 induced expressions of elastinolytic activities.
Efficient MHC Class II‐restricted presentation of measles virus to T cells relies on its targeting to its cellular receptor human CD46 and involves an endosomal pathway
Authors: Gerlier D. , Trescol‐Biémont M.‐C. , Varior‐Krishnan G. , Naniche D. , Fugier‐Vivier I. , Rabourdin‐Combe C.
Published: October 2002

The role of the measles virus (MV) receptor, human CD46, in the uptake of MV and antigen presentation by Major Histocompatibility Complex (MHC) class II molecules was investigated. Expression of CD46 in murine B cells resulted in cells highly efficient in capturing UV‐inactivated MV particles and presenting both envelope hemagglutinin H and nucleoprotein N to specific T cell hybridomas. Although MV fuse with the plasma membrane of its target cells, presentation of both MV‐H and ‐N was sensitive to inhibition by chloroquine but was not affected by a tripeptide which prevents virus‐cell fusion. Whereas 50 μM of chloroquine was required to inhibit presentation of MV‐H, purified H or soluble N, only a two‐fold lower concentration was required to inhibit that of MV‐N. This shows that some CD46‐mediated captured MV particles are endocytosed, then disrupted and processed in an endosome/lysosome compartment.
The influence of maternal nicotine exposure on the interalveolar septal status of neonatal rat lung.
Authors: Maritz G. S. , Thomas R.‐A.
Published: October 2002

The aim of this study was to determine the effect of maternal nicotine exposure (1 mg nicotine/kg body mass/day, subcutaneously) on the status of the alveolar septa of the 1 to 21 day old offspring. The data obtained showed swelling of type II and interstitial cell mitochondria. The type I:type II cell ratio decreased as a result of type II cell proliferation. The number of capillaries per unit length of septum was also significantly lower than that of control lung. Ruptured blood‐air barriers also occur in the nicotine exposed lungs of rats of all age groups. The results show that maternal nicotine exposure interfered with the morphometric and morphologic characteristics of the septa of lung tissue of the offspring.
Role of feeder cells in spreading and cytoskeleton organization of newborn rat keratinocytes.
Authors: Gorelik J. V. , Blinova M. I. , Diakonov I. A. , Kukhareva L. V. , Pinaev G. P.
Published: October 2002

We studied the effect of feeder cells (fibroblasts) and a mixture of the extracellular matrix components, Matrigel, on spreading and cytoskeleton organization of newborn rat keratinocytes (REK). REK formed lamellipodia on being plated together with feeder cells and on the Matrigel as a substrate whereas the same REK plated alone on a plastic surface formed filopodia. REK lamellipodia formation in co‐cultures depended on the fibroblast addition time. Although conditioned medium from fibroblast cultures was not enough to induce lamellipodia, the extracellular matrix left after fibroblast removal was as effective as Matrigel. Our results indicate that lamellipodia formation seems to depend on the factor(s) secreted by fibroblasts and associated with the extracellular matrix.
The cell and the organism: the role of subdivisional cell replication in the development and maintenance of the multicellular organism
Authors: Okun Milton R. , Edelstein Leon M.
Published: October 2002

Evidence of new cell formation from nucleoli (subdivisional cell replication) was observed in vitro and in vivo. Mouse melanoma cells, human fibroblasts, and rat mast cells were observed in tissue culture with phase contrast time‐lapse cinematography. Evidence of subdivisional cell replication seen in tissue culture was supported by observations of mast cells, cervical epithelial cells, melanoma cells, keratinocytes, and fungal spores in vivo. Indirect evidence for subdivisional cell replication was the presence of differentiated form and function in nuclei and nucleoli. Synergism between subdivisional replication and mitotic replication (subdivisional expansion) is believed to be a key to morphogenesis, whereby cellular and subdivisional zones act as biologic "molds". It is believed that subdivisional cell replication has a key role in maintenance of differentiated form in multicellular organisms, as well as in morphogenesis.
Proteins reacting with anti‐spectrin antibodies are present in Chlamydomonas Cells.
Authors: Lorenz Michal , Bisikirska Brygida , Hanus‐Lorenz Beata , Strzalka Kazimierz , Sikorski Aleksander F.
Published: October 2002

It was found either in Western‐blot analysis or in indirect immunofluorescence microscopy that cells of the alga Chlamydomonas reinhardhi contain polypeptides cross‐reactng with antibodies directed against red blood cell spectrin. The protein could also be detected by immunoprecipitation with anti‐spectrin antibodies. C. reinhardtii cells contain distinct polypeptide chains reacting with antibodies directed against either α‐ or β‐ spectrin subunits. This protein was extracted from the cells with low ionic strength solution but was not with nonionic detergent.
Centrosome behaviour and orientation of centrioles under the action of energy transfer inhibitors.
Authors: Alieva I. B. , Vorobjev I. A.
Published: October 2002

2,4‐dinitrophenol, dinitrophenol together with deoxyglucose, sodium azide and ouabain didn't alter cytoplasmic microtubule (MT) network of cultured PK (pig kidney embryo) cells, meanwhile they induced an increase in the average number of pericentriolar satellites and percentage of centrioles with the primary cilium in these cells. Also all drugs studied increase number of MTs attached to and oriented towards the centrosome. Under the action of ouabain the total number of MTs around the centrosome doubled, meanwhile the number of long MTs emanating from the centrosome increased more than 15 times. Under the action of all drugs studied, except sodium azide, the number of maternal centrioles oriented perpendicularly to the substrate surface increased significantly from that in control cells.
Effects on properties of a thiol protease from Xenopus embryos of changes in substrate and assay conditions.
Authors: Miyata Shohei , Nishibe Yasuo , Kihara Hirozi K.
Published: October 2002

A protease was purified from Xenopus embryos. Proteolytic activity of the protease against BSA had an optimum pH of 3.8 in acetate buffer and was not detectable at neutral pH. However, when embryonic proteins were used as substrates and digested in phosphate buffer, proteolysis of embryonic proteins was enhanced and was detectable from pH 5.0 to pH 7.0. Digestion of three proteins were mainly detected in digestion of total embryonic proteins. The proteins digested had the same mobilities (on SDS polyacrylamide gel) as yolk proteins. The protease was present in the cytoplasm and around yolk granules. We propose that this protease mainly cleaves a certain yolk proteins in the cytoplasm of Xenopus embryos.
Fibroblast growth factors: at the heart of angiogenesis.
Authors: Slavin J.
Published: October 2002

Acidic fibroblast growth factor (FGF‐1) and basic fibroblast growth factor (FGF‐2) are ubiquitous cytokines found in many tissues. They have effects on multiple cell types derived from mesoderm and neuroectoderm, including endothelial cells. In this review the structure and function of the fibroblast growth factor family and its receptors are described. The evidence implicating both FGF‐1 and FGF‐2 in the control of blood vessel formation is presented and their involvement in normal and pathological angiogenesis during adult life is then described in more detail.
Proteins reacting with anti‐spectrin antibodies are present in Chlamydomonas cells.
Authors: Lorenz Michal , Bisikirska Brygida , Hanus‐Lorenz Beata , Strzalka Kazimierz , Sikorski Aleksander F.
Published: October 2002

It was found either in Western‐blot analysis or in indirect immunofluorescence microscopy that cells of the alga Chlamydomonas reinhardtii contain polypeptides cross‐reacting with antibodies directed against red blood cell spectrin. The protein could also be detected by immunoprecipitation with anti‐spectrin antibodies. C. reinhardtii cells contain distinct polypeptide chains reacting with antibodies directed against either α‐ or β‐spectrin subunits. This protein was extracted from the cells with low ionic strength solution but was not with nonionic detergent.
COLLAGEN SYNTHESIS AND CELL GROWTH IN CHICK EMBRYO FIBROBLASTS: INFLUENCE OF COLCHICINE, CYTOCHALASIN B AND CONCANAVALIN A
Authors: BODO M. , CARINCI P. , BARONI T. , BECCHETTI E. , BELLUCCI C. , PEZZETTI F. , GIAMMARIOLI M. , STABELLINI G. , ARENA N.
Published: October 2002

Culturing of chick embryo fibroblasts in the presence of colchicine or cytochalasin B with and without concanavalin A (Con A) demonstrated that colchicine induces greater neosynthesis of endocellular type I collagen, whereas cytochalasin B boosts secretion. The effects are modified by the addition of Con A, which increases α2more than a1 chain production.3H‐thymidine incorporation is unaffected by cytochalasin B, but stimulated by colchicine. Con A neutralizes the stimulatory action of colchicine. It would therefore seem that Con A exerts transmembrane control of effects induced by colchicine and cytochalasin B by binding to cell surface receptors and so triggering rearrangement of the cytoskeleton.
MITOCHONDRIOGENESIS IN MATURING SEA URCHIN OOCYTES: A COMPUTERIZED RECONSTRUCTION ANALYSIS
Authors: FAIS D. , KIREEV I. , SOUKHOMLINOVA M. , MORICI G. , POLYAKOV V.
Published: October 2002

The dynamics of chondriome changes in oogenesis of the sea urchin Paracentrotus lividus were studied by electron microscopy. An oocyte‐enriched fraction obtained by gonad mechanical dissociation without protease treatment was used. The shape, size and arrangement of mitochondria (Mt) in cells were quantitatively analysed on the basis of data from reconstruction experiments, with serial sections performed using a specific computer program. At all stages of oogenesis, the chondriome was shown to consist of rod‐shaped Mt of various lengths and also of small amounts of globular Mt about 0.3 μm in diameter. Chondriome transformation during oogenesis is shown to involve the following processes: (1) a 64‐fold increase in number of Mt, with the ratio of cytoplasm to Mt volume quite constant in the course of oogenesis; (2) an increase in length of Mt to a maximum of 1.54 μm in medium oocytes and successive considerable mitochondrial division; (3) changes in Mt ultrastructure; and (4) a clustering of Mt. In a mature egg, the modal value of Mt length was reduced and, unlike the oocytes, was more homogeneous, and the Mt were completely clustered.
SCALARIFORM JUNCTIONS: A REVISED MODEL
Authors: DALLAI R. , BURIGHEL P. , MARTINUCCI G. B. , LANE N. J.
Published: October 2002

The structure of scalariform junctions has been analysed in a number of different animal groups by a variety of techniques. These junctions generally display a highly regular intercellular cleft straddled by indistinct cross‐striations. They are often in intimate spatial association with mitochondria which lie in parallel to the leaflets of their junctional membranes. Both intercellular and intramembranous features of these junctions have been studied in this report and certain common characteristics are revealed in all species examined. The intercellular cross‐striations seen in this junctional type are found to be actually hollow columns or pillars, of hour‐glass shape, regularly spaced in rhomboidal, or hexagonal arrays which may be anchored in place by certain of the intramembranous particles (IMPs) that occur in abundance on the membrane Pface. The density of the pillars is less than that of the IMPs. The other particles in the junctional area on both P and E faces may therefore be involved in ion transport, since the particular tissues in which these junctions are found are always involved in fluid flow. Those organisms which exhibit scalariform junctions have no closed circulatory system and thus may require some specialized osmoregulatory control in their excretory tissues. Those tissues which exhibit these junctions include organs such as rectal pads, rectal papillae, gills and nephridia, all of which share a similar physiological function even though they are found in organisms which occupy very different habitats. Such organisms include arthropods of different classes, as well as tunicates, where the presence of the scalariform junctions is restricted to a very specialized gut region. A revised model of scalariform junctions is presented here, which encompasses our new observations of their features. These include intercellular columns which are hollow and ‘hour‐glass’, rather than straight sided, in side view, together with their spacing and orderly hexagonal or rhomboidal pattern of distribution; their possible tethering by only a certain percentage of the IMPs in the junctional area is also incorporated in this model.
NECROSIS OF LUNG EPITHELIAL CELLS BY FILARIAL PARASITIC PROTEIN VIA AN EARLY INDUCTION OF c‐H‐rasAND TNFα EXPRESSION
Authors: MAYA A. , JAYARAMAN K. , BALAKRISHNAN A.
Published: October 2002

The direct interaction of filarial proteins with lung epithelial cells was examined to determine the possible mechanism of inducing cell death, an event that is observed in patients with tropical pulmonary eosinophilia. Exposure of lung epithelial cells to filarial parasitic proteins,Brugia malayi(BmA),Setaria digitata(Sd), and recombinant filarial protein (pGT 7)in vitrofor more than 2 days, causes the appearance of DNA fragments both in the cytoplasm and culture supernatants, while no fragmentation was observed in the untreated controls. The release of DNA fragments both in the cytoplasm and the culture supernatants simultaneously, indicates that cell death is induced by a necrotic event rather than apoptosis. Fluorescent‐labelled studies also indicate the fragmentation of DNA increasing in a time‐dependent manner. Normal cellular function is controlled through several oncogenes. The modulation of specific proto‐oncogenes like myc, ras and TNFα during exposure to filarial parasitic proteins reveal elevated levels of expression of ras and TNFα as early as 2 hours, implicating their involvement prior to DNA fragmentation leading to pathogenesis.
EFFECTS OF EXPOSURE TO ELECTROMAGNETIC RADIATION AT 835 MHz ON GROWTH, MORPHOLOGY AND SECRETORY CHARACTERISTICS OF A MAST CELL ANALOGUE, RBL‐2H3
Authors: DONNELLAN M. , McKENZIE D. R. , FRENCH P. W.
Published: October 2002

A mast cell line, RBL‐2H3, was exposed to 835MHz for 20 minutes, three times per day for 7 days at a power density of 8.1±3mW/cm2From day 4 onwards, it was observed that the rate of DNA synthesis and cell replication increased, that actin distribution and cell morphology became altered, and the amount of β‐hexosaminidase (a marker of granule secretion) released in response to a calcium ionophore was significantly enhanced, in comparison to unexposed cultures. There were no effects seen on levels of cytoskeletal protein synthesis or of beta‐actin mRNA. Morphological changes persisted following subculture for at least 7 days in the absence of further exposure. It is hypothesized that effects of exposure to an electromagnetic field at 835MHz may be mediated via a signal transduction pathway.
EXPRESSION OF THE TESTIS‐SPECIFIC HSP70‐RELATED GENE (HST70 GENE) IN SOMATIC NON‐TESTICULAR RAT TISSUES REVEALED BY RT‐PCR AND TRANSGENIC MICE ANALYSIS
Authors: ŚCIEGLIŃSKA DOROTA , WIDŁAK WIESŁAWA , RUSIN MAREK , MARKKULA MERJA , KRAWCZYK ZDZISŁAW
Published: October 2002

The hst70 gene which belongs to rat HSP70 multigene family is highly expressed in pachytene spermatocytes. Using a transgenic mice model it was found that the promoter of the rat hst70 gene directs the expression of the chloramphenicol acetyl transferase (CAT) reporter gene not only to testis but also to multiple somatic tissues. In wild‐type rats the expression of the hst70 gene in tissues other than testis was confirmed by non‐quantitative reverse transcription polymerase chain reaction (RT‐PCR) analysis. Beside the testis, the CAT expression in transgenic mice and the hst70 gene transcripts in wild‐type rats were found in brain, pituitary, epididymis, vas deferens, adrenals, spleen, lung, ovary, oviduct and uterus. The only tissue in which both the CAT expression and the hst70 gene activity has not been found was the liver. These observations suggest possibly more universal, not confined to spermatogenesis, function of the hst70 gene.
THE STRUCTURE OF THE CENTROMERIC REGION OF CHO CHROMOSOMES
Authors: SUMNER A. T.
Published: October 2002

CHO chromosomes, prepared for fluorescence microscopy, or for scanning electron microscopy, sometimes show a splitting of the centromere proper into two sister centromeres, with a space between them, while the sister chromatids are joined in the most proximal regions of the chromosome arms. It is suggested that this might represent the final stage of chromatid splitting before the anaphase separation of chromatids.
ADHESION OF L1210 CELLS TO SULFONATED STYRENE COPOLYMER SURFACES: IMAGING OF F‐ACTIN AND α‐ACTININ
Authors: KowalczyńSka H.M , Nowak‐Wyrzykowska M.
Published: October 2002

The static adhesion of living L1210 cells to sulfonated copolymer surfaces of different sulfonic group content and the actin cytoskeleton organization in the adhering cells were studied. The strength of the cell—substratum interaction was estimated by determining the relative number of cells remaining adherent despite experiencing a shearing force equal to 1.25×10−11N caused by the laminar flow of the medium. The cell—substratum interaction took place in a medium with or without serum. The distribution of F‐actin and α‐actinin in the adhering cells was determined in sequences of fluorescent images of cell optical slices with the use of a computer method of cell image analysis. It was shown that the surface sulfonic groups affect not only the rate and strength of cell—substratum adhesion but also the F‐actin and α‐actinin distribution (in the cell regions near the substratum surface) in cells adhering in the medium containing serum. These proteins, concentrated in the tips of microvilli, were observed as dots. The distinctness (discernibleness) and sizes of these dots depend on the surface content of sulfonic groups. F‐actin is located at the periphery of the cells in cells adhering in the medium without serum and α‐actinin is concentrated in small dots at the periphery and in the central part of the cells.