bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation Crosslinking of Poly(ethylene‐co‐octene) with Electron Beam Radiation
Authors: Perraud Sophie , Vallat Marie‐France , Kuczynski Jerzy
Published: March 2003

Films of ethylene‐co‐octene copolymer are irradiated in air after moulding between Mylar® films with electron beam at different doses. To correlate the change in structure with properties, the irradiated and unirradiated samples are characterised by FTIR spectroscopy, swelling and mechanical measurements. Obtained changes are dependant on the radiation dose of the incident electron beam. Irradiation induces trans‐vinylene double bonds detected by FTIR spectroscopy in transmission mode. No hydroxyl (OH) and carbonyl (CO) groups were recorded by FTIR spectroscopy. More drastic changes are observed with swelling method and by mechanical properties showing the crosslinking effect. Based on the results obtained by analytical techniques used in this study, free radicals mechanism involving mainly the pendant chains of the PE‐co‐O is proposed.

Strain at break versus gel fraction.

magnified image

Strain at break versus gel fraction.
Pushout with virtual thresholds buffer management scheme in a shared buffer ATM switch
Authors: Yang Ruey‐Bin , Chu Yuan‐Sun , Wu Cheng‐Shong , Liang Ming‐Cheng
Published: March 2003

In this paper we investigate the performance metrics of buffer management schemes. In general, the selective pushout (SP) scheme can support very low loss probability of the high‐priority cells, but it may cause unfairness of buffer allocation among different output queues and high overall cell loss probability. In order to fit the dynamic required performance metrics of ATM switches, a novel buffer management scheme called pushout with virtual thresholds (PVT) is proposed. In the PVT scheme, each output queue is guaranteed to increase in length until its virtual threshold (VT). Simulation results show the PVT can dynamically achieve the fairness and low overall cell loss probability or very low loss probability of the high priority cells by adequately adjusting the VT. Specially, when the VT = 0, the PVT control can be viewed as the SP control. Copyright © 2003 John Wiley & Sons, Ltd.
Numerical study of the HP version of mixed discontinuous finite element methods for reaction‐diffusion problems: The 1D case
Authors: Chen Hongsen , Chen Zhangxin , Li Baoyan
Published: March 2003

This article studies the stability and convergence of the hp version of the three families of mixed discontinuous finite element (MDFE) methods for the numerical solution of reaction‐diffusion problems. The focus of this article is on these problems for one space dimension. Error estimates are obtained explicitly in the grid size h, the polynomial degree p, and the solution regularity; arbitrary space grids and polynomial degree are allowed. These estimates are asymptotically optimal in both h and p for some of these methods. Extensive numerical results to show convergence rates in h and p of the MDFE methods are presented. Theoretical and numerical comparisons between the three families of MDFE methods are described. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 525–553, 2003
Quantitative characterization of the optical properties of absorbing polymer films: Comparative investigation of the internal reflection intensity analysis method
Authors: Liu Tao , Henderson Clifford L. , Samuels Robert
Published: March 2003

Nondestructive, three‐dimensional refractive‐index measurements are used for the determination of both the crystallinity and orientation in thin polymer films. The prism wave‐guide coupler is particularly suited for three‐dimensional isotropic and anisotropic thin‐film studies because of the quantitative character of the information obtained and the ease of data acquisition. It has been limited, however, to determining only the refractive index of transparent or weakly absorbing thin‐film samples. On the basis of thin‐film optics, this study develops a new internal reflection intensity analysis (IRIA) method, which uses the intensity information rather than the conventional mode angle values to acquire both the refractive index and the extinction coefficient over a range of transparent to highly absorbing polymer films. Therefore, the IRIA method overcomes the limitations of this prism wave‐guide coupler technique, which can only measure the refractive index of a weakly absorbing sample. With a Metricon PC‐2010 as the skeletal framework, a prototype instrument has been developed to apply and test the IRIA method. A study comparing both the refractive index and extinction coefficient obtained with ellipsometry, ultraviolet–visible/near‐infrared reflectometry, and IRIA for solvent blue 59 dyed polystyrene films confirms that the IRIA method is effective for obtaining the three‐dimensional refractive indices and extinction coefficients of polymer films. In addition, the refractive index and extinction coefficient spectrum (400–800 nm) of solvent blue 59 have been determined with the effective media theory. Furthermore, the three‐dimensional complex refractive indices of highly absorbing black electrical tape, inaccessible to other optical measurement because of its surface character, has been determined by the IRIA method. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 842–855, 2003
Can field‐scale habitat diversification enhance the biocontrol potential of spiders?
Authors: Samu Ferenc
Published: March 2003

The study investigated the effect of strip management in alfalfa on the abundance and diversity of spiders. In strip management, narrow strips were left unmown in the crop, which were then shifted at next mowing. In an experimental field, out of the six 50 × 50‐m blocks, three received strip management and three were managed traditionally (ie the whole block was mown). Our main hypothesis was that unmown strips will contain a more diverse and abundant spider assemblage, which will increase spider numbers in the mown parts of the crop. Over the 3 years of the study, unmown strips contained a spider assemblage of more than 50% higher abundance than in control alfalfa. Species diversity was also greater in the strips, and the presence of specific indicator species could be shown. We found that five dominant species comprised over 75% of spiders in the strips, and they were the same species as those that are dominant in alfalfa, where they represent 85% of all spiders. In contrast, a neighbouring meadow, which was a control in the study, also had high diversity, but different dominant species. The main result of the experiment was negative in that elevated abundance of spiders in unmown strips did not raise spider numbers in the mown strips of alfalfa, where abundance was only marginally higher than in the control alfalfa. We can speculate that better ecological conditions in unmown strips attract and conserve spiders from neighbouring areas and from the crop at mowing. We suggest that if diversification is more interspersed within the crop, we have a higher chance of increasing the number of natural enemies and bringing them closer to pests, so that they can interact more intensively.

© 2003 Society of Chemical Industry
Structure–activity relationship study of alkynyl ether insecticide synergists and the development of MB‐599 (verbutin)
Authors: Bertók Béla , Pap László , Árvai Géza , Bakonyvári Ildikó , Ribai Zsuzsanna Kuruczné
Published: March 2003

Structure–activity relationships of aryl alkynyl synergists of the general formula of Ar–Q–R, where Q represents a bridging structure, were studied using a standardised testing system and Relative Potency values. Ethers, esters, oxime ethers, amides and amines were prepared and evaluated. The length of the R‐alkynyl chain, the role of the bridge and the substitution of the aromatic ring were examined systematically. The most potent compounds possessed an aromatic ring connected via a bridge of three atoms to an alkynyl chain, forming together a linear side‐chain of six atoms. Several highly potent compounds were synthesised of which one (MB‐599; proposed common name verbutin) was selected for development as a selective insecticide synergist in crop protection. Its high potential at practical insecticide:synergist ratios makes possible the reduction of the total amount of insect‐control chemicals applied, and its use as an additive to produce new formulations of existing insecticides makes it highly advantageous in resistance management, giving a new tool to sustain the effectiveness of a wide range of insecticides. A product containing a (1 + 1) mixture of verbutin and beta‐cypermethrin was launched in Hungary in 2002.

© 2003 Society of Chemical Industry
Characterization of Hungarian isolates of zucchini yellow mosaic virus (ZYMV, potyvirus) transmitted by seeds of Cucurbita pepo var Styriaca
Authors: Tóbiás István , Palkovics László
Published: March 2003

Zucchini yellow mosaic virus (ZYMV) has emerged as an important pathogen of cucurbits within the last few years in Hungary. The Hungarian isolates show a high biological variability, have specific nucleotide and amino acid sequences in the N‐terminal region of coat protein and form a distinct branch in the phylogenetic tree. The virus is spread very efficiently in the field by several aphid species in a non‐persistent manner. It can be transmitted by seed in holl‐less seeded oil pumpkin (Cucurbita pepo (L) var Styriaca), although at a very low rate. Three isolates from seed transmission assay experiments were chosen and their nucleotide sequences of coat proteins have been compared with the available CP sequences of ZYMV. According to the sequence analysis, the Hungarian isolates belong to the Central European branch in the phylogenetic tree and, together with the ZYMV isolates from Austria and Slovenia, share specific amino acids at positions 16, 17, 27 and 37 which are characteristic only to these isolates. The phylogenetic tree suggests the common origin of distantly distributed isolates which can be attributed to widespread seed transmission.

© 2003 Society of Chemical Industry
Human colon cancer cells differ in their sensitivity to curcumin‐induced apoptosis and heat shock protects them by inhibiting the release of apoptosis‐inducing factor and caspases
Authors: Rashmi R. , Santhosh Kumar T.R. , Karunagaran D.
Published: March 2003

Mild heat treatment induced the expression of heat shock protein‐70 (hsp70), hsp90 and hsp27 in two human colon cancer cell lines, one derived from primary tumor, SW480, and the other derived from the secondary lymph node tissue, SW620, of the same patient. SW620 cells appear to be more sensitive to curcumin‐induced apoptosis. Heat shock protects both the human colon cancer cells from curcumin‐induced apoptosis. Heat shock prevented, at least in part, the release of apoptosis inducing factor from mitochondria induced by curcumin although the release of second mitochondria derived activator of caspase and cytochrome c was unaffected in both the cells. Moreover, heat shock reduced curcumin‐induced activation of caspases 9 and 3 but not 8.
The hydrolysis of lysophospholipids and nucleotides by autotaxin (NPP2) involves a single catalytic site
Authors: Gijsbers Rik , Aoki Junken , Arai Hiroyuki , Bollen Mathieu
Published: March 2003

Autotaxin (NPP2) is a tumor cell motility‐stimulating factor that displays both a nucleotide pyrophosphatase/phosphodiesterase activity and a recently described lysophospholipase D activity. The hydrolysis of nucleotides is a metal‐assisted reaction that occurs via a nucleotidylated threonine in the catalytic site. We show here that the catalytic site threonine and the metal‐coordinating residues are also essential for the hydrolysis of lysophospholipids. In comparing the substrate specificity of NPP2 and the closely related NPP1 and NPP3, we found that only NPP2 displayed a lysophospholipase D activity, whereas NPP1 and NPP3 had a much higher nucleotide pyrophosphatase activity.
In vivo studies of liver‐type fatty acid binding protein (L‐FABP) gene expression in liver of transgenic zebrafish (Danio rerio)
Authors: Her Guor Mour , Chiang Chia-Chang , Chen Wen-Ya , Wu Jen-Leih
Published: March 2003

Mammalian liver fatty acid binding protein (L‐FABP) is a small cytosolic protein in various tissues including liver, small intestine and kidney and is thought to play a crucial role in intracellular fatty acid trafficking and metabolism. To better understand its tissue‐specific regulation during zebrafish hepatogenesis, we isolated 5′‐flanking sequences of the zebrafish L‐FABP gene and used a green fluorescent protein (GFP) transgenic strategy to generate liver‐specific transgenic zebrafish. The 2.8‐kb 5′‐flanking sequence of zebrafish L‐FABP gene was sufficient to direct GFP expression in liver primordia, first observed in 2 dpf embryos and then continuously to the adult stage. This pattern of transgenic expression is consistent with the expression pattern of the endogenous gene. F2 inheritance rates of 42–51% in all the seven transgenic lines were consistent with the ratio of Mendelian segregation. Further, hhex and zXbp‐1 morphants displayed a visible liver defect, which suggests that it is possible to establish an in vivo system for screening genes required for liver development.
Functional EF‐Tu with large C‐terminal extensions in an E. coli strain with a precise deletion of both chromosomal tuf genes
Authors: Schnell Robert , Abdulkarim Farhad , Kálmán Miklós , Isaksson Leif A.
Published: March 2003

An Escherichia coli strain was constructed in which both chromosomal genes encoding elongation factor (EF)‐Tu (tufA and tufB) have been inactivated with precise coding sequence replacements. A tufA gene in an expression vector is supplied as the sole EF‐Tu source. By using plasmid replacement, based on plasmid incompatibility, mutant EF‐Tu variants with a large C′‐terminal extension up to 270 amino acids were studied and proved to be functional in a strain lacking the chromosomal tufA and tufB genes.
Signal peptide of Lassa virus glycoprotein GP‐C exhibits an unusual length
Authors: Eichler Robert , Lenz Oliver , Strecker Thomas , Garten Wolfgang
Published: March 2003

Lassa virus glycoprotein is synthesized as precursor GP‐C into the lumen of the endoplasmic reticulum and cleaved posttranslationally into the N‐terminal subunit GP‐1 and the C‐terminal subunit GP‐2 by subtilase SKI‐1/S1P. The N‐terminal portion of the primary translation product preGP‐C contains a signal peptide of unknown length. In order to demonstrate the signal peptide cleavage site, purified viral GP‐1 isolated from Lassa virus particles was N‐terminally sequenced as TSLYKGV, identical to amino acids 59–65 of GP‐C. Mutational analysis of the amino acid residues flanking the putative cleavage site led to non‐cleavable preGP‐C indicating that no other signal peptide cleavage site exists. Interestingly, GP‐C mutants with a non‐cleavable signal peptide were not further processed by SKI‐1/S1P. This observation suggests that the signal peptide cleavage is necessary for GP‐C maturation and hence for Lassa virus replication.
Early changes in gene expression in two models of Batten disease
Authors: Elshatory Yasser , Brooks Andrew I. , Chattopadhyay Subrata , Curran Timothy M. , Gupta Praveena , Ramalingam Vijay , Hofmann Sandra L. , Pearce David A.
Published: March 2003

Infantile and juvenile neuronal ceroid lipofuscinosis (NCLs) are progressive neurodegenerative disorders of childhood with distinct ages of clinical onset, but with a similar pathological outcome. Infantile and juvenile NCL are inherited in an autosomal recessive manner due to mutations in the CLN1 and CLN3 genes, respectively. Recently developed Cln1‐ and Cln3‐knockout mouse models share similarities in pathology with the respective human disease. Using oligonucleotide arrays we identified reproducible changes in gene expression in the brains of both 10‐week‐old Cln1‐ and Cln3‐knockout mice as compared to wild‐type controls, and confirmed changes in levels of several of the cognate proteins by immunoblotting. Despite the similarities in pathology, the two mutations affect the expression of different, non‐overlapping sets of genes. The possible significance of these changes and the pathological mechanisms underlying NCL diseases are discussed.
Specific detection of non‐functional human P2X7 receptors in HEK293 cells and B‐lymphocytes
Authors: Barden J.A. , Sluyter R. , Gu B.J. , Wiley J.S.
Published: March 2003

P2X7 receptor/channels mediate ATP‐induced apoptosis in a range of cells including lymphocytes. HEK293 cells were transfected with wild‐type human P2X7 receptor or site‐directed mutant constructs (K193A, K311A and E496A) known to be non‐functional from measurements of barium/ethidium influx in the presence of ATP or 2′,3′‐O‐(4‐benzoylbenzoyl)‐ATP. An antibody was designed against an epitope from a loop adjacent to the extracellular ATP site. The epitope was unavailable in cells expressing normal functional surface receptors. Non‐functional surface receptors as well as intracellular receptors selectively bound the antibody. So did B‐lymphocytes from chronic lymphocytic leukemia patients expressing non‐functional (E496A) mutant receptor.
Cathodoluminescence Efficiency Dependence on Excitation Density in
n-Type Gallium Nitride
Authors: Phillips Matthew R. , Telg Hagen , Kucheyev Sergei O. , Gelhausen Olaf , Toth Milos
Published: March 2003

Cathodoluminescence (CL) spectra from silicon doped and undoped
wurtzite n-type GaN have been measured in a SEM under a wide range of
electron beam excitation conditions, which include accelerating
voltage, beam current, magnification, beam diameter, and specimen
temperature. The CL intensity dependence on excitation density was
analyzed using a power-law model (ICL
∝ Jm) for each of the observed CL
bands in this material. The yellow luminescence band present in both
silicon and undoped GaN exhibits a close to cube root (m =
0.33) dependence on electron beam excitation at both 77 K and 300 K.
However, the blue (at 300 K) and donor-acceptor pair (at 77 K) emission
peaks observed in undoped GaN follow power laws with exponents of
m = 1 and m = 0.5, respectively. As expected from its
excitonic character, the near band edge emission intensity depends
linearly (m = 1) in silicon doped GaN and superlinearly
(m = 1.2) in undoped GaN on the electron beam current. Results
show that the intensities of the CL bands are highly dependent not only
on the defect concentration but also on the electron-hole pair density
and injection rate. Furthermore, the size of the focussed electron beam
was found to have a considerable effect on the relative intensities of
the CL emission peaks. Hence SEM parameters such as the objective lens
aperture size, astigmatism, and the condenser lens setting must also be
considered when assessing CL data based on intensity measurements from
this material.
Charge-Related Problems Associated with X-Ray Microanalysis in the
Variable Pressure Scanning Electron Microscope at Low Pressures
Authors: Griffin Brendan J. , Suvorova Alexandra A.
Published: March 2003

In variable pressure scanning electron microscopy (VPSEM) the current
data suggests that considerable caution is required in the
interpretation of X-ray data from nonconductive samples, depending on
the operating conditions. This article reviews some of the documented
approaches and presents data that illustrate the nature and magnitude
of the effects of charge above, on, and in the sample on the detected
X-ray emissions from the sample and from elsewhere within the VPSEM
specimen chamber. The collection of reliable and reproducible X-ray
data has been found to require relatively high specimen chamber gas
pressures, at the upper end of or beyond the available pressures for
most VPSEMs. It is also shown that sample characteristics, including
composition, strongly influence local charge effects, which can
significantly affect the primary electron landing energy and
consequently the resultant emitted X-ray signal under low pressure
environments.
Incidence and Duration of Unemployment Spells: Implications on the Wage Differentials of Part‐Time and Full‐Time Workers
Authors: Baffoe‐Bonnie John
Published: March 2003

This article analyzes the extent to which incidence of unemployment and duration of unemployment spells affect the wage differentials between full‐time and part‐time workers. The estimation results of a sample selectivity bias–adjusted wage equation reveal that high incidences of unemployment are associated with low wages for both full‐time and part‐time workers. However, the reduction in wages due to incidence of unemployment is larger for full‐time workers in high‐paid jobs than for their part‐time counterparts. Duration of unemployment spells affects full‐time and part‐time workers differently. In general, longer unemployment spells tend to increase the wages of full‐time workers but tend to depress the wages of part‐time workers. Although the probability of unemployment is not a factor in explaining the wage differential, the duration of unemployment accounts for a substantial portion (about 66.6% in full sample) of the wage differential that exists between full‐time and part‐time workers.
Polysaccharide Peptide Mediates Apoptosis by Up-regulating p21 Gene and Down-regulating Cyclin D1 Gene
Authors: Chow Louis W.C. , Lo Christine S.Y. , Loo Wings T.Y. , Hu Xi-chun , Sham Jonathan S.T.
Published: March 2003

The use of herbal medicine is a common practice among Chinese women with breast cancer. Yunzhi (Voriolus versicolor), a substance that is regarded as a biological response modifier, is frequently used. The aim of the present study is to evaluate the anti-proliferative action of Yunzhi, polysaccharide peptide (PSP), on breast cancer cells. Breast cancer cells (MDA-MB-231) were cultured with and without PSP for 7 days. Cell growth at 24, 72, 120 and 168 hours was measured by Cell Proliferation Reagent (WST-1). Cells treated with PSP were found to have a significant reduction in cell proliferation as compared to controls after 72 hours of incubation. This lasted for 168 hours. When the effect of PSP on apoptosis was studied by the TdT-mediated X-dUTP nick end-labeling (TUNEL) assay, we found that PSP had a significant effect upon apoptosis from 24 hours onward. Immunostaining showed that PSP increased p21 expression and decreased cyclin D1 expression. In conclusion, PSP is effective in inhibiting cell proliferation through apoptosis. The mechanism for the apoptosis may be through up-regulation of p21 and down-regulation of cyclin D1.
ECONOMIC POLICIES IN THE LIGHT OF HAPPINESS STUDIES WITH REFERENCE TO SINGAPORE
Authors: NG YEW-KWANG
Published: March 2003

Recent happiness studies show that income explains only 2% of the variance in happiness. Quality-of-life indicators also correlate less with income but more with advances in knowledge at the world level. Individuals and nations still engage in the rat race for higher incomes due to the competition for relative standing, the ignoring of the environmental disruption effects, our accumulation instinct, the influence of advertising and peer pressure, and the inadequate recognition of the habituation effect. In addition, economists over-estimate the costs of public spending, emphasising the excess burden of taxation, ignoring the negative excess burden in the public spending side and ignoring the grosser inefficiency of private consumption. These considerations suggest that more public spending in the right areas like education, research, and environmental protection may be much more welfare-improving despite some unavoidable inefficiencies. The restriction of private cars in Singapore may be desirable despite being excessive in accordance to the narrower economic analysis. It may also be appropriate to emphasise non-income factors important for welfare, including freedom and democracy.
STATISTICAL TECHNIQUES FOR TEXT CLASSIFICATION BASED ON WORD RECURRENCE INTERVALS
Authors: BERRYMAN M. J. , ALLISON A. , ABBOTT D.
Published: March 2003

We present a method for characterizing text based on a statistical analysis of word recurrence interval. This method can be used for extracting keywords from text, and also for comparing texts by an unknown author against a set of known authors. We also use these methods to comment on the controversial question of who wrote the letter to the Hebrews in the New Testament.
ChlamydomonasDIP13 and human NA14: a new class of proteins associated with microtubule structures is involved in cell division
Authors: Pfannenschmid Frank , Wimmer Verena C. , Rios Rosa-Maria , Geimer Stefan , Kröckel Ulla , Leiherer Andreas , Haller Katrin , Nemcová Yvonne , Mages Wolfgang
Published: March 2003

We have cloned and characterized a single copy C. reinhardtii gene containing an open reading frame of 333 nucleotides encoding a 12.7 kDa protein. The novel protein, DIP13, exhibits 60% identity with two mammalian proteins, human NA14 and an unnamed mouse protein. Homologous sequences are also present in several protozoan, trematode and fish genomes, but no homologs have been found in the completed genomes of yeast, Drosophila, C. elegans and A. thaliana. By using a specific antibody we have localized DIP13 to microtubule structures, namely basal bodies, flagellar axonemes and cytoplasmic microtubules. Anti-DIP13 antibody also specifically recognized human NA14 by immunofluorescence and stained basal bodies and flagella of human sperm cells as well as the centrosome of HeLa cells. Expression of the DIP13 open reading frame in antisense orientation in Chlamydomonas resulted in multinucleate, multiflagellate cells,which suggests a role for this protein in ensuring proper cell division. Thus,DIP13/NA14 could represent the founding members of a new class of highly conserved proteins that are associated with microtubule structures.
Cadherin-mediated adhesion is essential for myofibril continuity across the plasma membrane but not for assembly of the contractile apparatus
Authors: Luo Yang , Radice Glenn L.
Published: March 2003

The strong coordinated contraction of heart muscle is dependent on the correct alignment and connection of the myofibrils across the plasma membrane. Previous studies indicate that N-cadherin is involved in cardiac myocyte adhesion and myofibrillogenesis. To investigate whether N-cadherin is specifically required for normal myocyte structure and function, we cultured myocytes from wild-type, N-cadherin-null and mutant embryos expressing the epithelial cadherin E-cadherin. In contrast to previous studies in chicken using N-cadherin-perturbing antibodies, our in vitro studies with mouse cells demonstrate that N-cadherin is not required for myofibrillogenesis, but is critical for myofibril organization. That is, N-cadherin-deficient myocytes beat and myofibrils were well formed; however, alignment of the myofibrils through regions of cell-cell contact was lost, resulting in their random orientation. Gap junctions were perturbed in the N-cadherin-null myocytes. By contrast, focal contacts appeared normal in the mutant cells. Furthermore,E-cadherin restored normal cell morphology and behavior to the N-cadherin-deficient myocytes, including proper alignment of the myofibrils. We conclude that a different adhesive system, most probably integrin, is responsible for myofibrillogenesis in the N-cadherin-null myocytes.
PARP-3 localizes preferentially to the daughter centriole and interferes with the G1/S cell cycle progression
Authors: Augustin Angélique , Spenlehauer Catherine , Dumond Hélène , Ménissier-de Murcia Josiane , Piel Matthieu , Schmit Anne-Catherine , Apiou Françoise , Vonesch Jean-Luc , Kock Michael , Bornens Michel , de Murcia Gilbert
Published: March 2003

A novel member of the poly(ADP-ribose) polymerase (PARP) family, hPARP-3,is identified here as a core component of the centrosome. hPARP-3 is preferentially localized to the daughter centriole throughout the cell cycle. The N-terminal domain (54 amino acids) of hPARP-3 is responsible for its centrosomal localization. Full-length hPAPR-3 (540 amino acids, with an apparent mass of 67 kDa) synthesizes ADP-ribose polymers during its automodification. Overexpression of hPARP-3 or its N-terminal domain does not influence centrosomal duplication or amplification but interferes with the G1/S cell cycle progression. PARP-1 also resides for part of the cell cycle in the centrosome and interacts with hPARP-3. The presence of both PARP-1 and PARP-3 at the centrosome may link the DNA damage surveillance network to the mitotic fidelity checkpoint.
The block of ryanodine receptors selectively inhibits fetal myoblast differentiation
Authors: Pisaniello Alessandro , Serra Carlo , Rossi Daniela , Vivarelli Elisabetta , Sorrentino Vincenzo , Molinaro Mario , Bouché Marina
Published: March 2003

Differentiation and morphogenesis of skeletal muscle are complex and asynchronous events that involve various myogenic cell populations and extracellular signals. Embryonic and fetal skeletal myoblasts are responsible for the formation of primary and secondary fibers, respectively, although the mechanism that diversifies their fate is not fully understood. Calcium transients appear to be a signaling mechanism that is widely utilized in differentiation and embryogenesis. In mature skeletal muscle, calcium transients are generated mainly by ryanodine receptors (type 1 and type 3),which are involved in excitation-contraction coupling. However, it is not clear whether the activity of these receptors is important for contractile activity alone or whether it may also play a role in regulating the differentiation/developmental processes. To clarify this point, we first examined the expression of the receptors during development. The results show that the expression of both receptors appears as early as E13 during limb muscle development and parallels the expression of skeletal myosin. The expression and the activity of both receptors is maintained in vitro by all myogenic cell populations isolated from different stages of development,including somitic, embryonic and fetal myoblasts and satellite cells. Blocking ryanodine receptor activity by using ryanodine inhibits in vitro differentiation of fetal myoblasts (judged by the expression of sarcomeric myosin and formation of multinucleated myotubes) but not of somitic or embryonic and satellite muscle cells. This block is caused by the transcriptional inhibition of markers characteristic of terminal differentiation, rather than commitment, as the expression of muscle regulatory factors is not impaired by ryanodine treatment. Taken together, the data reported in this paper demonstrate that, although calcium transients represent a general mechanism for the control of differentiation and development, multiple calcium-dependent pathways may be relevant in different myogenic populations during development. Moreover, since fetal myoblasts are responsible for the formation of secondary fibers during development, and therefore for the building of the bulk of muscular mass, these results suggest that calcium release from ryanodine receptors plays a role in the histogenesis of mammalian skeletal muscle.
Tensegrity II. How structural networks influence cellular information processing networks
Authors: Ingber Donald E.
Published: March 2003

The major challenge in biology today is biocomplexity: the need to explain how cell and tissue behaviors emerge from collective interactions within complex molecular networks. Part I of this two-part article, described a mechanical model of cell structure based on tensegrity architecture that explains how the mechanical behavior of the cell emerges from physical interactions among the different molecular filament systems that form the cytoskeleton. Recent work shows that the cytoskeleton also orients much of the cell's metabolic and signal transduction machinery and that mechanical distortion of cells and the cytoskeleton through cell surface integrin receptors can profoundly affect cell behavior. In particular, gradual variations in this single physical control parameter (cell shape distortion)can switch cells between distinct gene programs (e.g. growth, differentiation and apoptosis), and this process can be viewed as a biological phase transition. Part II of this article covers how combined use of tensegrity and solid-state mechanochemistry by cells may mediate mechanotransduction and facilitate integration of chemical and physical signals that are responsible for control of cell behavior. In addition, it examines how cell structural networks affect gene and protein signaling networks to produce characteristic phenotypes and cell fate transitions during tissue development.
Extracellular Ca2+ sensing contributes to excess Ca2+ accumulation and vacuolar fragmentation in apmr1Δ mutant ofS. cerevisiae
Authors: Kellermayer Richard , Aiello David P. , Miseta Attila , Bedwell David M.
Published: March 2003

Previous studies have suggested that yeast strains lacking the Ca2+-ATPase Pmr1p are unable to maintain an adequate level of Ca2+ within the Golgi apparatus. It is thought that this compartmental store depletion induces a signal that causes an increased rate of Ca2+ uptake and accumulation in a manner similar to the capacitative Ca2+ entry (CCE) response in non-excitable mammalian cells. To explore this model further, we examined cellular Ca2+uptake and accumulation in a pmr1Δ strain grown in the presence of a reduced level of divalent cations. We found that the level of Ca2+ uptake and accumulation in a pmr1Δ strain increased as the concentration of divalent cations in the growth medium decreased. These results are inconsistent with a model in which cellular Ca2+ uptake and accumulation are determined solely by the depletion of Ca2+ in an intracellular compartment. Instead, our results suggest that a second regulatory mechanism couples cellular Ca2+uptake to the availability of Ca2+ in the extracellular environment. Furthermore, we found that various conditions that increase the level of cytosolic Ca2+ correlate with vacuolar fragmentation in wild-type (WT), pmr1Δ and pmr1Δ/pmc1Δ yeast strains. This suggests that vacuolar fragmentation might function as a normal physiological response to Ca2+ stress that increases the vacuolar surface/volume ratio,thereby maximizing the sequestration of this important signaling molecule.
A New Method for the Synthesis of Baccatin III
Authors: Shiina Isamu , Iwadare Hayato , Sakoh Hiroki , Hasegawa Masatoshi , Tani Yu-ichirou , Mukaiyama Teruaki
Published: March 2003

Baccatin III was efficiently synthesized from the BC ring system of Taxol,2α,10β-dibenzyloxy-11β-(t-butyldimethylsil-oxy)-7β-hydroxy-1α-(4-methoxybenzyloxy)-8β,15,15-trimethyl-4-methylene-trans-bicyclo[6.4.0]dodecan-9-one(1), by succes-sive constructions of A and D rings via respective intramolecular pinacol coupling and oxetane forming reaction.
Enantioselective Hydrogenation of (E)-α-Phenylcinnamic Acid on Pd/TiO2 Catalyst Modified by Cinchona Alkaloids : Effect of Modifier Structure
Authors: Nitta Yuriko , Shibata Akira
Published: March 2003

The effect of modifier structure on enantioselectivity and activity in the hydrogenation of (E)-α-phenylcinnamic acid with cinchona-modified Pd/TiO2 catalyst has been found to be in contrast to the hydrogenation of α-ketoesters with modified platinum catalysts. It is suggested that the interaction of the hydroxyl group at C9 of cinchonidine with the carboxyl group in the substrate is crucial to induce a high enantioselectivity.
Formation of Ordered Nanometer-sized Polymer Dots on Silicon by Friction Rubbing Method
Authors: Sano Masahito , Okamura Jyunko , Shinkai Seiji
Published: March 2003

Regular arrays of poly(ethylene) deposits, about 10 nm high and 160 nm in diameter, separated by 340 nm, were formed by simply rubbing the polymer plate against the surface of silicon just below the melting point of the polymer.
Novel Reversible Chlorine-Gas Uptake and Release System with Bis(polypyrazolylborato)ruthenium(II) in the Solid State
Authors: Onishi Masayoshi , Ikemoto Kazuto , Hiraki Katsuma , Aoki Katsuyuki
Published: March 2003

Novel reversible chlorine-gas uptake and release cycles were shown by the bis(polypyrazolylborato)ruthenium(II) complexes in the solid state, with their one-electron [Ru(III)]/[Ru(II)] redox-couples. Formation of ground-state charge-trandsfer species was also observed for the complexes with some halocarbon solvents.
Aqueous Soluble Single-Wall Carbon Nanotube
Authors: Li Bo , Shi Zujin , Lian Yongfu , Gu Zhennan
Published: March 2003

By condensation reaction with 2-aminoethanesulfonic acid (taurine), the end of single-wall carbon nanotube (SWCNT) was linked with sulfonic acid group, which enables much enhancement of the solubility of SWCNT in water.
Simultaneous Catalytic Removal of Nitrogen Oxides and Soot by Copper-Loaded MFI Zeolites
Authors: Teraoka Yasutake , Kanada Kazunori , Furukawa Hiroshi , Moriguchi Isamu , Kagawa Shuichi
Published: March 2003

Cu-loaded MFI zeolites showed the catalytic activity for the oxidation of soot and reduction of NOx simultaneously in the soot–NOx–O2 reaction system. Ion-exchanged and impregnated catalysts showed the comparable activity, but the latter was decidedly superior to the former with respect to the selectivity to NO reduction into N2.
Layered Lithium Insertion Material of LiCo1/3Ni1/3Mn1/3O2 for Lithium-Ion Batteries
Authors: Ohzuku Tsutomu , Makimura Yoshinari
Published: March 2003

Layered LiCo1/3Ni1/3Mn1/3O2 was prepared by a solid state reaction at 1000 °C in air and examined in nonaqueous lithium cells. LiCo1/3Ni1/3Mn1/3O2 showed a rechargeable capacity of 150 mAh g−1 in 3.5–4.2 V or 200 mAh g−1 in 3.5–5.0 V. Operating voltage of Li / LiCo1/3Ni1/3Mn1/3O2 was by 0.2–0.25 V lower than that of a cell with LiCoO2 or LiMn2O4 and by 0.15–0.3 V higher than that with LiNiO2 or LiCo1/2Ni1/2O2 due to a complex solid solution mechanism.
Relativistic Effects for Polarizabilities and Hyperpolarizabilities of Rare Gas Atoms
Authors: Nakajima Takahito , Hirao Kimihiko
Published: March 2003

The relativistic effects for static polarizabilities α and hyperpolarizabilities γ of rare gas atoms (Ne through Rn) are investigated theoretically with the third-order Douglas–Kroll method. The results yield interesting trends of relativity in going from Ne to Rn: The relativistic effect decreases α values of Ne and Ar and increases the values of Kr, Xe, and Rn, and it decreases γ values of Rn slightly and increases the values of other rare gas atoms, while the electron correlation effect increases α and γ of all rare gas atoms.
Nanofiltration–Complexation: A New Method for Isotopic Separation of Heavy Metals
Authors: Chitry Frédéric , Pellet-Rostaing Stéphane , Vigneau Olivier , Lemaire Marc
Published: March 2003

Nanofiltration coupled with a selective complexation step was applied to separate isotopes of neodymium and gadolinium in aqueous solution.
2,3-Tetrakis[4-(N-2-naphthyl-N-phenylamino)phenoxy]-substituted Metal-free and Metal Phthalocyanines as a Novel Class of Amorphous Molecular Materials
Authors: Ottmar Martin , Ichisaka Toshiki , Subramanian L R , Hanack Michael , Shirota Yasuhiko
Published: March 2003

A novel family of metal-free and metal phthalocyanines containing triarylamine moieties are synthesized. These compounds are well soluble and readily form stable amorphous glasses with high glass transition temperatures, as evidenced by differential scanning calorimetry and X-ray diffraction, and constitute a new class of amorphous molecular materials.
Melting of the All-trans Planar Modification of Triblock Oligomers α-n-Alkyl-ω-n-alkoxyoligo(oxyethylene)s
Authors: Fukuhara Koichi , Akisue Miyuki , Matsuura Hiroatsu
Published: March 2003

Melting behavior of the all-trans planar modification of triblock oligomers H(CH2)n(OCH2CH2)mO(CH2)nH (n = 6, 8, and 10; m = 1–4) was studied by differential scanning calorimetry. The melting point, enthalpy of melting, and entropy of melting were measured and compared with those for n-alkanes that have similar molecular structures. Structural changes in going from the crystalline phase to the liquid phase were discussed on the basis of the observed thermal behavior.
Chirooptical Control of Liquid Crystalline Textures Containing Chromium Complex by Irradiation of Circular Polarized Light
Authors: Anzai Nobuhiro , Machida Shinjiro , Horie Kazuyuki
Published: March 2003

A cholesteric texture was induced in the liquid crystal (a mixture of N-(4-ethoxybenzylidene)-4-n-alkylanilines doped with (R)-(+)-1,1′-bi-2-naphthol and racemic chromium tris(3-butyl-2,4-pentanedionate) (Cr(3-Buacac)3) by the irradiation of right circular polarized light (r-CPL) and resulting chiroselective photoinversion of Cr(3-Buacac)3. After irradiation of left circular polarized light (l-CPL), the cholesteric fingerprint texture was erased.
A Dramatic Improvement of Enantioselectivity of Lipase in Organic Solvents by Addition of Aqueous SDS: A Close Correlation between Enantioselectivity and Conformational Flexibility of Lipase
Authors: Ueji Shin-ichi , Nishimura Miyuki , Kudo Risa , Matsumi Rina , Watanabe Keiichi , Ebara Yasuhito
Published: March 2003

The enantioselectivity of the lipase-catalyzed esterification of 2-(4-substituted phenoxy)propanoic acids was found to be dramatically enhanced by addition of aqueous sodium dodecyl sulfate (SDS) as a new type of additive to the reaction medium, isopropyl ether. The origin of the enhanced enantiomeric differentiation may be attributed to the increased conformational flexibility of lipase triggered by the SDS action, the flexibility of which can be estimated from the changes in the ESR spectra observed for the mobility of a spin label bound to its active-site.
Multicolor Fluorescent π-Conjugated Oligomer Having Salicylideneaniline Moieties
Authors: Nomura Ryoji , So Yoshiki , Izumi Atsushi , Nishihara Yusuke , Yoshino Katsumi , Masuda Toshio
Published: March 2003

A multicolor luminescence active π-conjugated oligomer, in which the emission color can be controlled by changing the wavelength of the excitation light, was synthesized by the condensation of 1,2-phenylenediamine with 5-dodecyloxy-2-hydroxyterephthalaldehyde.
Glycosyl 6-Nitro-2-benzothiazoate. A Highly Efficient Donor for β-Stereoselective Glycosylation
Authors: Mukaiyama Teruaki , Hashihayata Takashi , Mandai Hiroki
Published: March 2003

Highly β-stereoselective glycosylations of glycosyl acceptors having a primary hydroxyl group by using a novel glycosyl donor, α-glycosyl 6-nitro-2-benzothiazoate (3), proceeded smoothly in the presence of a catalytic amount of trifluoromethanesulfonic acid (TfOH) in CH2Cl2 at −78 °C to afford the corresponding glycosides in high yields. The donor 3 gave β-saccharides more dominantly compared with those using other α-glycosyl donors such as thioform- and trichloroacet-imidates or fluoride under the same conditions.
Health care utilization of families of carpenters with alcohol or substance abuse‐related diagnoses
Authors: Lipscomb Hester J. , Dement John M. , Li Leiming
Published: March 2003

Background

Patterns of health care utilization of families of carpenters with and without alcohol and/or substance abuse related diagnoses (ASRD) were compared.

Methods

Utilization data for families of 13,657 carpenters for a 10 year period were analyzed. Concordance of diagnoses among family members was assessed and proportionate utilization ratios were used to compare the experiences of families of carpenters with and without ASRD.

Results

Twenty‐eight percent of the spouses with ASRD had a carpenter spouse with a similar diagnosis. Twenty‐four percent of the families with a child with ASRD had a parent with one of these diagnoses compared to 9.4% of families without any children with ASRD (P < 0.0001). Families of carpenters with alcohol or ASRD also had different patterns of health care utilization.

Conclusions

Utilization patterns were influenced to a significant degree by concordant diagnoses among spouses and children. Excess mental health care was seen among families of carpenters with ASRD above their care for substance abuse treatment.Am. J. Ind. Med. 43:361–368, 2003. © 2003 Wiley‐Liss, Inc.
Interactions with Aromatic Rings in Chemical and Biological Recognition
Authors: Meyer Emmanuel A. , Castellano Ronald K. , Diederich François
Published: March 2003

Intermolecular interactions involving aromatic rings are key processes in both chemical and biological recognition. Their understanding is essential for rational drug design and lead optimization in medicinal chemistry. Different approaches—biological studies, molecular recognition studies with artificial receptors, crystallographic database mining, gas‐phase studies, and theoretical calculations—are pursued to generate a profound understanding of the structural and energetic parameters of individual recognition modes involving aromatic rings. This review attempts to combine and summarize the knowledge gained from these investigations. The review focuses mainly on examples with biological relevance since one of its aims it to enhance the knowledge of molecular recognition forces that is essential for drug development.
Crystallographic report: Polymeric [bis(N,N‐diethyldithiocarbamato) (trans‐1,2‐bis(4‐pyridyl)ethylene)cadmium(II)]
Authors: Chai Jishan , Lai Chian Sing , Yan Jiayi , Tiekink Edward R. T.
Published: March 2003

The linear polymeric structure of [Cd(S2CNEt2)2(trans‐NC5H4C(H)C(H)C5H4N)]∞ shows bidentate coordination by the dithiocarbamate ligands and a distorted octahedral geometry for cadmium, defined by a trans‐N2S4 donor set. Copyright © 2003 John Wiley & Sons, Ltd.
Overcharging in Colloids: Beyond the Poisson–Boltzmann Approach
Authors: Quesada‐Pérez Manuel , González‐Tovar Enrique , Martín‐Molina Alberto , Lozada‐Cassou Marcelo , Hidalgo‐Álvarez Roque
Published: March 2003

A broad range of manufactured products and biological fluids are colloids. The ability to understand and control the processes (of scientific, technological and industrial interest) in which such colloids are involved relies upon a precise knowledge of the electrical double layer. The traditional approach to describing this ion cloud around colloidal particles has been the Gouy–Chapman model, developed on the basis of the Poisson–Boltzmann equation. Since the early 1980s, however, more sophisticated theoretical treatments have revealed both quantitative and qualitative deficiencies in the Poisson–Boltzmann theory, particularly at high ionic strengths and/or high surface charge densities. This review deals with these novel approaches, which are mostly computer simulations and approximate integral equation theories based on the so‐called primitive model. Special attention is paid to phenomena that cannot be accounted for by the classic theory as a result of neglecting ion size correlations, such as overcharging, namely, the counterion concentration in the immediate neighborhood of the surface is so large that the particle surface is overcompensated. Other illustrative examples are the nonmonotonic behavior of the electrostatic potential and attractive interactions between equally charged surfaces. These predictions are certainly remarkable and, on paper, they can have an effect on experimentally measurable quantities (for instance, electrophoretic mobility). Even so, these new approaches have scarcely been applied in practice. Thus a critical survey on the relevance of ion size correlation in real systems is also included. Overcharging of macroions can also be brought about by adsorption of oppositely charged polyelectrolytes. Noteworthy examples and theoretical approaches for them are also briefly reviewed.