bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical compartmentation of vegetating algae species as a basis for their growth‐specific characterization
Authors: Gerashchenko Bogdan I. , Kosaka Toshikazu , Hosoya Hiroshi 
Published: August 2002

AbstractBackgroundThe number of microalgal strains known to date is enormous and continuously growing, and their characterization accordingly requires quick and reliable methodologies.MethodsAsynchronously growing logarithmic (3‐ and 6‐day cultures) and stationary (9‐day cultures) phase cell populations of two algae species that are difficult to distinguish microscopically (one Chlorella sp., C. vulgaris [c‐27], and another that might belong to the same genus, SA‐3 algae exsymbiotic from Paramecium bursaria) were characterized by means of flow cytometry (FCM). Forward light scatter (FSC) of algae was monitored in association with their 90° side light scatter (SSC) and fluorescence of endogenous chlorophyll (FL3‐height).ResultsTwo‐parameter FSC versus SSC and FSC versus FL3‐height plots distinctly showed growth‐specific compartmentation of algae into discrete cell subpopulations staying at a particular stage of the life cycle, and numbers of cells constituting these subpopulations could be quantitated. The growth pattern of C. vulgaris (c‐27) differed substantially from that of SA‐3 algae, particularly in the late‐logarithmic (6‐day) cultures. At this phase of growth, C. vulgaris (c‐27) cells compartmentalized into three subpopulations, whereas SA‐3 cells compartmentalized into two subpopulations. Different compartmentations of optical signals from late‐logarithmic phase SA‐3 algae and C. vulgaris (c‐27) likely were caused by the differences in timing of the life cycle stages of these types of cells.ConclusionsGrowth‐specific compartmentation of vegetating microalgae by FCM provides a good basis for characterization of morphologically similar algae species. Because algae are also present in symbiotic relationships with other organisms, this tool might be of potential interest for the study of symbiosis mechanisms. Cytometry 48:153–158, 2002. © 2002 Wiley‐Liss, Inc.
Variations of components of the plasminogen activation system with the cell cycle in benign prostate tissue and prostate cancer
Authors: Plas Eugen , Carroll Veronica A. , Jilch Ruth , Simak Rainer , Mihaly Judith , Melchior Sebastian , Thüroff Joachim W. , Binder Bernd R. , Pflüger Heinz 
Published: August 2002

AbstractBackground: Components of the fibrinolytic system are involved in tumor cell invasion and metastasis. Previous investigations suggested a cell cycle‐dependent expression of urokinase‐type plasminogen activator (u‐PA) in epithelial cells. In order to determine a correlation of cell cycle phases with the fibrinolytic system, we investigated the expression of u‐PA, tissue‐type plasminogen activator (t‐PA), and plasminogen activator inhibitor type 1 (PAI‐1) in normal and tumor‐containing prostate extracts and analyzed a possible relationship with flow cytometry‐determined proliferative activity of the samples. Cell cycle phases were correlated with fibrinolytic parameters in prostate tissue. Methods: Samples were obtained from patients undergoing radical prostatectomy for prostate cancer and separated into two portions for DNA analysis and the detection of u‐PA, t‐PA, and PAI‐1. Flow cytometric analysis was performed according to the Vindelov technique. The concentrations of u‐PA, t‐PA, and PAI‐1 were determined from tissue extracts after homogenization by an enzyme‐linked immunosorbent assay (ELISA) technique. Results: Correlations of u‐PA and t‐PA expression with the frequency of G0/G1, S, G2M, S‐phase fraction (SPF), and proliferation index (PI) for normal prostate and prostate cancer revealed no significant correlation. The only significant finding was observed in normal tissue revealing a positive correlation between PAI‐1 expression and G0/G1 and a negative correlation with S‐phase, SPF, and PI. No dependence of PAI‐1 expression on different cell phases was found in prostate cancer. Furthermore, no significant correlation of u‐PA, t‐PA, and PAI‐1 with cell cycles in organ‐confined (<pT3a) and disseminated (≥pT3a) tumors was found. No significant correlation in prostate cancer of components of the fibrinolytic system differentiated according to tumor grade or perineural tumor infiltration and cell cycle analysis was found. Only in highly differentiated G1 (Gleason 2–4) cancer, u‐PA had a significant positive correlation with G2M‐phase. Conclusion: Absence of a correlation between levels of components of the fibrinolytic system and cell cycle phases suggests that the reported association between increases of some of these components and aggressive biological behavior of prostate cancer is secondary to non–cell cycle‐related mechanisms. Cytometry (Comm. Clin. Cytometry) 46:184–189, 2001. © 2001 Wiley‐Liss, Inc.
Interaction of nocodazole with tubulin isotypes
Authors: Xu Keliang , Schwarz Patricia M. , Ludueña Richard F. 
Published: August 2002

AbstractNocodazole is an anti‐mitotic drug that has long been used as an experimental tool in cell biology. Although nocodazole is known to bind with high affinity to tubulin and to inhibit microtubule assembly, very little has been done on its precise mechanism of action. In fact, its binding to the different isotypes of tubulin has never been addressed. Although the nocodazole binding site overlaps with that of colchicine, the two drugs are structurally quite different. The tubulin molecule is an α/β heterodimer; both α and β exist as various isotypes whose distribution and drug‐binding properties are significantly different. In this study, we measured the binding affinity of nocodazole for purified tubulin isotypes. Using fluorescence quenching analysis, we found that the binding kinetics of nocodazole with each type of tubulin best fits a two‐affinity Michaelis‐Menten binding model. The apparent dissociation constants for the high‐affinity binding sites are 0.52 ± 0.02 for αβII, 1.54 ± 0.29 for αβIII, and 0.29 ± 0.04 for αβIV. Thus, nocodazole has the highest affinity for αβIV and the lowest affinity for αβIII. Knowledge of the isotype specificity of nocodazole may allow for development of novel therapeutic agents based on this drug. Drug Dev. Res. 55:91–96, 2002. © 2002 Wiley‐Liss, Inc.
Facilitating postural control: Effects on the reaching behavior of 6‐month‐old infants
Authors: Hopkins Brian , Rönnqvist Louise 
Published: August 2002

AbstractIn this study, 3‐D kinematic as well as 2‐D videorecordings were made of the reaching behavior of infants aged about 6 months who were not yet able to sit. Detailed analyses of these recordings were directed toward specifying the effects of providing additional postural support to the lower body on the spatial and temporal features of such behavior. To detect these effects, reaching and associated head movements in this modified condition were compared to those made while the infants sat in an age‐appropriate and commercially available chair lacking the supplementation of support for the pelvic region and upper legs. Findings consistent with predictions included better head stabilization and smoother reaching movements when the infants were in the modified chair. In addition, these two achievements were negatively related to reaching experience. These, and other findings, underscore the infrequently investigated supposition that changes in postural control induce improvements in the control of reaching movements during infancy. Recommendations are made about how the procedure adopted in the present study could be used in subsequent research to give further insights into the codevelopment of posture and action. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 168–182, 2002. DOI 10.1002/dev.10021
Assembly of thick, thin, and titin filaments in chick precardiac explants
Authors: Rudy Diane E. , Yatskievych Tatiana A. , Antin Parker B. , Carol C. Gregorio  
Published: August 2002

AbstractDe novo cardiac myofibril assembly has been difficult to study due to the lack of available cell culture models that clearly and accurately reflect heart muscle development in vivo. However, within precardiac chick embryo explants, premyocardial cells differentiate and commence beating in a temporal pattern that corresponds closely with myocyte differentiation in the embryo. Immunofluorescence staining of explants followed by confocal microscopy revealed that distinct stages of cardiac myofibril assembly, ranging from the earliest detection of sarcomeric proteins to the late appearance of mature myofibrils, were consistently recognized in precardiac cultures. Assembly events involved in the early formation of sarcomeres were clearly visualized and accurately reflected observations described by others during chick heart muscle development. Specifically, the early colocalization of α‐actinin and titin dots was observed near the cell periphery representing I‐Z‐I‐like complex formation. Myosin‐containing thick filaments assembled independently of actin‐containing thin filaments and appeared centered within sarcomeres when titin was also linearly aligned at or near cell borders. An N‐terminal epitope of titin was detected earlier than a C‐terminal epitope; however, both epitopes were observed to alternate near the cell periphery concomitant with the earliest formation of myofibrils. Although vascular actin was detected within cells during early assembly stages, cardiac actin predominated as the major actin isoform in mature thin filaments. Well‐aligned thin filaments were also observed in the absence of organized staining for tropomodulin at thin filament pointed ends, suggesting that tropomodulin is not required to define thin filament lengths. Based on these findings, we conclude that the use of the avian precardiac explant system accurately allows for direct investigation of the mechanisms regulating de novo cardiac myofibrillogenesis. © 2001 Wiley‐Liss, Inc.
Direct separation of in vivo and in vitro am3 revertants in transgenic mice carrying the phix174 am3, cs70 vector
Authors: Malling Heinrich V. , Delongchamp Robert R. 
Published: August 2002

AbstractTarget genes in most transgenic systems have higher spontaneous mutation frequencies than do endogenous mammalian genes. Spontaneous mutations in transgenes predominantly arise from three sources: (1) mutations fixed in the animals, (2) mutations arising from replication errors caused by damage to the DNA that may have occurred in vivo or in vitro and then was fixed during amplification of the vector in vitro, and (3) mutations arising during replication of non‐revertant phages in non‐permissive bacteria. An assay based on single bursts was developed to directly distinguish between the in vivo and in vitro origins of revertants. The size of the aliquot is determined by mutant frequency and is adjusted so that ideally no more than 10 to 20% of the aliquots contain a bacterial cell transformed with a mutant phage. Mutations are detected as revertants of an amber mutation (am3) in phiX174 am3, cs70. The minimum burst size of non‐revertant phiX am3, cs70 from splenic DNA on a permissive bacterial strain was larger than 30 plaque‐forming units (pfu). Based on this observation, a burst size of 31 plaque‐forming revertants was chosen as the minimum burst size of a fixed mutation. The single burst assay was tested on DNA from spleens of animals that were treated with 150 mg/kg 1‐ethyl‐1 nitrosurea. Only the fraction of aliquots with single bursts of revertants (> 30) increased in the treated animals compared to the controls. In contrast, there was no difference between treated and control animals for revertant frequencies calculated for burst sizes ≤30 pfu. Among the spontaneous mutations, only 30% were caused by mutations fixed in animals (i.e. burst size >30 pfu). Total average revertant frequency measured in DNA from treated animals was less than twofold more than the average spontaneous frequency (P = 0.048). When frequencies were based on burst sizes >30, there was a 4.6‐fold increase among treated animals compared with controls (P = 0.026). The single burst‐assay resulted in a more sensitive test for mutagenicity because it eliminated noise from in‐vitro mutations. Environ. Mol. Mutagen. 37:345–355, 2001 Published 2001 Wiley‐Liss, Inc.
The significance of rock structure, lithology and pre‐glacial deep weathering for the shape of intermediate‐scale glacial erosional landforms
Authors: Olvmo Mats , Johansson Magnus 
Published: August 2002

AbstractThe main landforms within the glacially scoured Precambrian rocks of the Swedish west coast are closely connected to the principal structural pattern and have lately been explained as mainly a result of etch processes, probably during the Mesozoic and with a possible second period of etching during the Neogene. To explore the effect of multiple glacial erosion on the rock surfaces, an island with two different lithologies and with striae from different directions was selected for a detailed study, focusing on the shape of roches moutonnées. Air‐photo interpretation of bedrock lineaments and roches moutonnées combined with detailed field mapping and striae measurements are used to interpret the structural and lithological control on the resulting shape. The study reveals a significant difference in shape between roches moutonnées in augen‐granite and orthogneiss. Low elongated and streamlined roches moutonnées occur in the gneiss area, striated by a Late Weichselian ice flow from the NE. This ice flow is subparallel with both the local dominant trend of topographically well‐expressed joints and the schistosity of the gneiss. Frequently, there are no signs of quarrying on the lee‐sides of the gneiss roches moutonnées and hence they resemble the shape of whalebacks, or ruwares, as typically associated with the exposed basal weathering surface found in tropical areas. The granite roches moutonnées were formed by an older ice flow from the ESE, which closely followed the etched WNW–ESE joint system of the granite. Late Weichselian ice flow from the NE caused only minor changes of the landforms. On the contrary, marks of the early ESE ice flow are poorly preserved in the gneiss area, where it probably never had any large effect as the flow was perpendicular to both schistosity and structures and, accordingly, also to the pre‐glacial relief. The study demonstrates that coincidence between ice flow direction and pre‐glacially etched structures is most likely to determine the effects of glacial erosion. Copyright © 2002 John Wiley & Sons, Ltd.
Environmental applications of thermal extraction cone penetrometry and ultrafast gas chromatography/mass spectrometry
Authors: Robbat Albert 
Published: August 2002

AbstractThis article describes the collection and analysis of organic contaminants at depth without bringing soil to the surface. A thermal extraction cone penetrometer (TECP) probe was used to extract soil‐bound semivolatile organics, transferring them to the surface for analysis by ultrafast gas chromatography/mass spectrometry (GC/MS). Findings showed that polychlorinated biphenyls, polycyclic aromatic hydrocarbons, chlorinated pesticides, and explosives could be collected and analyzed in 5 min when the soil‐water content was <20% and in 15 min when it was between 20 and 35%. When the TECP was directly connected to the GC/MS, trinitrotoluene (TNT) and four of its synthetic precursors were speciated in 20 sec. Moreover, 51 VOCs were detected by membrane‐inlet mass spectrometry in ∼10 sec. Organics were “sniffed” from a vial and identified using the Ion Fingerprint Detection™ software. The algorithms provide the means to untangle complex mass spectra making real‐time, electronic nose detection and identification by MS possible. © 2001 John Wiley & Sons, Inc. Field Analyt Chem Technol 5: 60–68, 2001
The shallow flow equations solved on adaptive quadtree grids
Authors: Borthwick A. G. L. , Cruz León S. , Józsa J. 
Published: August 2002

AbstractThis paper describes an adaptive quadtree grid‐based solver of the depth‐averaged shallow water equations. The model is designed to approximate flows in complicated large‐scale shallow domains while focusing on important smaller‐scale localized flow features. Quadtree grids are created automatically by recursive subdivision of a rectangle about discretized boundary, bathymetric or flow‐related seeding points. It can be fitted in a fractal‐like sense by local grid refinement to any boundary, however distorted, provided absolute convergence to the boundary is not required and a low level of stepped boundary can be tolerated. Grid information is stored as a tree data structure, with a novel indexing system used to link information on the quadtree to a finite volume discretization of the governing equations. As the flow field develops, the grids may be adapted using a parameter based on vorticity and grid cell size. The numerical model is validated using standard benchmark tests, including seiches, Coriolis‐induced set‐up, jet‐forced flow in a circular reservoir, and wetting and drying. Wind‐induced flow in the Nichupté Lagoon, México, provides an illustrative example of an application to flow in extremely complicated multi‐connected regions. Copyright © 2001 John Wiley & Sons, Ltd.
The composite finite volume method on unstructured meshes for the two‐dimensional shallow water equations
Authors: Jiwen Wang , Ruxun Liu 
Published: August 2002

AbstractA composite finite volume method (FVM) is developed on unstructured triangular meshes and tested for the two‐dimensional free‐surface flow equations. The methodology is based on the theory of the remainder effect of finite difference schemes and the property that the numerical dissipation and dispersion of the schemes are compensated by each other in a composite scheme. The composite FVM is formed by global composition of several Lax–Wendroff‐type steps followed by a diffusive Lax–Friedrich‐type step, which filters out the oscillations around shocks typical for the Lax–Wendroff scheme. To test the efficiency and reliability of the present method, five typical problems of discontinuous solutions of two‐dimensional shallow water are solved. The numerical results show that the proposed method, which needs no use of a limiter function, is easy to implement, is accurate, robust and is highly stable. Copyright © 2001 John Wiley & Sons, Ltd.
Relationships between Australian real estate and stock market prices—a case of market inefficiency
Authors: Okunev John , Wilson Patrick , Zurbruegg Ralf 
Published: August 2002

AbstractThis paper explores the relationship between the Australian real estate and equity market between 1980 and 1999. The results from this study show three specific outcomes that extend the current literature on real estate finance. First, it is shown that structural shifts in stock and property markets can lead to the emergence of an unstable linear relationship between these markets. That is, full‐sample results support bi‐directional Granger causality between equity and real estate returns, whereas when sub‐samples are chosen that account for structural shifts the results generally show that changes within stock market prices influence real estate market returns, but not vice versa. Second, the results also indicate that non‐linear causality tests show a strong unidirectional relationship running from the stock market to the real estate market. Finally, from this empirical evidence a trading strategy is developed which offers superior performance when compared to adopting a passive strategy for investing in Australian securitized property. These results appear to have important implications for managing property assets in the funds management industry and also for the pricing efficiency within the Australian property market. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular analysis of nonrandom 8q12 deletions in acute lymphoblastic leukemia: Identification of two candidate genes
Authors: Bardet Valérie , Couque Nathalie , Cattolico Laurence , Hetet Gilles , Devaux Isabelle , Duprat Simone , Gressin Laetitia , Vilmer Etienne , Cavé Hélène , Grandchamp Bernard 
Published: August 2002

AbstractAcute lymphoblastic leukemia is the most common malignancy in childhood. High‐resolution allelotyping performed in our laboratory showed new chromosomal sites of nonrandom deletions. We have focused our work on 8q12 deletions, which we have found in about 4% of patients (eight of 205 informative cases). These deletions were of small size (less than 1 Mb) in all but one patient, and the deleted region common to all patients was delineated between two microsatellite markers (D8S1113 and D8S1763). This region was sequenced entirely from two overlapping bacterial artificial chromosomes. The common deleted region (120 kb) had a low GC content (37%), was composed more than 50% of LINE sequences, and contained only two candidate genes. The centromeric deletion borders were clustered within an interval of 33 kb between two microsatellite markers. This interval contains the first exon of an HMG‐1‐related gene (KIAA0808) and a putative gene, DL8q12, predicted to encode a protein with 231 amino acid residues with no homolog in protein databases. Analysis of the available mRNA from lymphoblastic cells of two patients with 8q12 deletions using common polymorphisms in the 3′ UTR of KIAA0808 showed monoallelic expression of this gene. Identification of a biallelic polymorphism in the first exon of DL8q12 showed that this gene was deleted in two of four informative cases. Sequencing of the exons of both genes from all patients with 8q12 deletions did not show any mutation, which suggests that neither of these genes behaves as a classic tumor suppressor gene. © 2002 Wiley‐Liss, Inc.
Genome profiles of familial/bilateral and sporadic testicular germ cell tumors
Authors: Kraggerud Sigrid Marie , Skotheim Rolf I. , Szymanska Jadwiga , Eknæs Mette , Fosså Sophie D. , Stenwig Anna E. , Peltomäki Päivi , Lothe Ragnhild A. 
Published: August 2002

AbstractIn order to investigate the genetics of testicular germ cell tumors (TGCTs), we examined 33 TGCTs, including 15 familial/bilateral and 18 sporadic tumors, using comparative genomic hybridization. The frequencies of the histological subtypes were comparable between the two groups. Gains of the whole or parts of chromosome 12 were found in 30 tumors (91%). Furthermore, increased copy number of the whole or parts of chromosomes 7, 8, 17, and X, and decreased copy number of the whole or parts of chromosomes 4, 11, 13, and 18 were observed in ≥50% of the tumors. Sixteen smallest regions of overlapping changes were delineated on 12 different chromosomes. The chromosomal copy numbers of familial/bilateral and sporadic TGCTs were comparable, suggesting similar genetic pathways to disease in both groups. However, significant differences were observed between the two main histological subgroups. Gains from 15q and 22q were associated with seminomas (P = 0.005 and P = 0.02, respectively), whereas gain of the proximal 17q (17q11.2–21) and high‐level amplification from chromosome arm 12p, and losses from 10q were associated with nonseminomas (P < 0.001, P = 0.04, and P = 0.03, respectively). © 2002 Wiley‐Liss, Inc.