bluuebunny/crossref_metadata_2025 huggingface dataset:
Somatic stem cells and the kinetics of mutagenesis and carcinogenesis
Authors: Cairns John
Published: September 2002

There is now strong experimental evidence that epithelial stem cells arrange their sister chromatids at mitosis such that the same template DNA strands stay together through successive divisions; DNA labeled with tritiated thymidine in infancy is still present in the stem cells of adult mice even though these cells are incorporating (and later losing) bromodeoxyuridine [Potten, C. S., Owen, G., Booth, D. & Booth, C. (2002)
J. Cell Sci.
115, 2381–2388]. But a cell that preserves “immortal strands” will avoid the accumulation of replication errors only if it inhibits those pathways for DNA repair that involve potentially error-prone resynthesis of damaged strands, and this appears to be a property of intestinal stem cells because they are extremely sensitive to the lethal effects of agents that damage DNA. It seems that the combination, in the stem cell, of immortal strands and the choice of death rather than error-prone repair makes epithelial stem cell systems resistant to short exposures to DNA-damaging agents, because the stem cell accumulates few if any errors, and any errors made by the daughters are destined to be discarded. This paper discusses these issues and shows that they lead to a model that explains the strange kinetics of mutagenesis and carcinogenesis in adult mammalian tissues. Coincidentally, the model also can explain why cancers arise even though the spontaneous mutation rate of differentiated mammalian cells is not high enough to generate the multiple mutations needed to form a cancer and why loss of nucleotide-excision repair does not significantly increase the frequency of the common internal cancers.
The essential role of Cited2, a negative regulator for HIF-1α, in heart development and neurulation
Authors: Yin Zhan , Haynie Jennifer , Yang Xiaoming , Han Baoguang , Kiatchoosakun Songsak , Restivo Joseph , Yuan Saying , Prabhakar Nanduri R. , Herrup Karl , Conlon Ronald A. , Hoit Brian D. , Watanabe Michiko , Yang Yu-Chung
Published: September 2002

Cited2 is a cAMP-responsive element-binding protein (CBP)/p300 interacting transcriptional modulator and a proposed negative regulator for hypoxia-inducible factor (HIF)-1α through its competitive binding with HIF-1α to CBP/p300. Disruption of the gene encoding Cited2 is embryonic lethal because of defects in the development of heart and neural tube. Morphological and Doppler echocardiographic analyses of Cited2
−/−
embryos reveal severe cardiovascular abnormalities, including pulmonic arterial stenosis and ventricular septal defects accompanied by high peak outflow velocities, features of the human congenital cardiac defect termed tetralogy of Fallot. The mRNA levels of several HIF-1α-responsive genes, such as vascular endothelial growth factor (VEGF), Glut1, and phosphoglycerate kinase 1, increased in the Cited2
−/−
hearts. The increase of VEGF levels is significant, because defects in the Cited2
−/−
embryos closely resemble the major defects observed in the VEGF transgenic embryos. Finally, compared with wild-type, cultured fibroblasts from Cited2
−/−
embryos demonstrate an enhanced expression of HIF-1α-responsive genes under hypoxic conditions. These observations suggest that functional loss of Cited2 is responsible for defects in heart and neural tube development, in part because of the modulation of HIF-1 transcriptional activities in the absence of Cited2. These findings demonstrate that Cited2 is an indispensable regulatory gene during prenatal development.
DNA detection using water-soluble conjugated polymers and peptide nucleic acid probes
Authors: Gaylord Brent S. , Heeger Alan J. , Bazan Guillermo C.
Published: September 2002

The light-harvesting properties of cationic conjugated polymers are used to sensitize the emission of a dye on a specific peptide nucleic acid (PNA) sequence for the purpose of homogeneous, “real-time” DNA detection. Signal transduction is controlled by hybridization of the neutral PNA probe and the negative DNA target. Electrostatic interactions bring the hybrid complex and cationic polymer within distances required for Förster energy transfer. Conjugated polymer excitation provides fluorescein emission >25 times higher than that obtained by exciting the dye, allowing detection of target DNA at concentrations of 10 pM with a standard fluorometer. A simple and highly sensitive assay with optical amplification that uses the improved hybridization behavior of PNA/DNA complexes is thus demonstrated.
Substrate-dependent reversal of anion transport site orientation in the human red blood cell anion-exchange protein, AE1
Authors: Knauf Philip A. , Law Foon-Yee , Leung Tze-Wah Vivian , Gehret Austin U. , Perez Martha L.
Published: September 2002

The tightly coupled, one-for-one exchange of anions mediated by the human red blood cell AE1 anion-exchange protein involves a ping-pong mechanism, in which AE1 alternates between a state with the anion-binding site facing inward toward the cytoplasm (Ei) and a state with the site facing outward toward the external medium (Eo). The conformational shift (Ei ↔ Eo) is only permitted when a suitable substrate such as Cl
−
or HCO

\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\setlength{\oddsidemargin}{-69pt}
\begin{document}
\begin{equation*}_{3}^{-}\end{equation*}\end{document}

(B
−
) is bound. With no anions bound, or with Cl
−
bound, far more AE1 molecules are in the inward-facing than the outward-facing forms (Ei ≫ Eo, ECli ≫ EClo). We have constructed a model for CI
−
–B
−
exchange based on Cl
−
–Cl
−
and B
−
–B
−
exchange data, and have used it to predict the heteroexchange flux under extremely asymmetric conditions, with either all Cl
−
inside and all B
−
outside (Cli-Bo) or
vice versa
(Bi-Clo). The experimental values of the ratio of the exchange rate for Bi-Clo to that for Cli-Bo are only compatible with the model if the asymmetry of bicarbonate-loaded sites (A
B
= EBo/EBi) > 10, the opposite of the asymmetry for unloaded or Cl-loaded sites. Furthermore, the Eo form has a higher affinity for HCO

\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\setlength{\oddsidemargin}{-69pt}
\begin{document}
\begin{equation*}_{3}^{-}\end{equation*}\end{document}

than for Cl
−
, whereas the Ei form has a higher affinity for Cl
−
. The fact that this “passive” system exhibits changes in substrate selectivity with site orientation (“sidedness”), a characteristic usually associated with energy-coupled “active” pumps, suggests that changes in affinity with changes in sidedness are a more general property of transport proteins than previously thought.
Immunosuppressive effects of tautomycetinin vivoandin vitrovia T cell-specific apoptosis induction
Authors: Shim Jae-Hyuck , Lee Heung-Kyu , Chang Eun-Ju , Chae Wook-Jin , Han Jin-Hwan , Han Duck-Jong , Morio Tomohiro , Yang Jung-Jin , Bothwell Alfred , Lee Sang-Kyou
Published: September 2002

Tautomycetin (TMC) was identified as an immunosuppressor of activated T cells. Inhibition of T cell proliferation with TMC was observed at concentrations 100-fold lower than those needed to achieve maximal inhibition with cyclosporin A (CsA). TMC specifically blocked tyrosine phosphorylation of intracellular signal mediators downstream of Src tyrosine kinases in a T cell-specific manner, leading to apoptosis due to cleavage of Bcl-2, caspase-9, caspase-3, and poly(ADP-ribose) polymerase, but not caspase-1. In TMC-treated rats that received a heterotopic cardiac allograft, the graft survived more than 160 days, comparable to graft survival in allografted rats treated with CsA. Thus, TMC, whose mechanism of action is different from that of CsA or FK506, can be used as a potent T cell-specific immunosuppressor.
Biodiversity, population regulation, and the stability of coral-reef fish communities
Authors: Carr Mark H. , Anderson Todd W. , Hixon Mark A.
Published: September 2002

Unprecedented population declines and extinctions because of human activities, combined with a growing recognition that such losses affect the stability of ecosystems, underscore the need to better understand how populations persist naturally. We provide field experimental evidence that high biodiversity—in particular, the combined effects of predators and competitors—acts in a way that regulates the size of local fish populations within their coral-reef community. These results indicate that complex interactions among multiple species are necessary for the stability of a highly diverse community, and so forewarn that overexploiting such species may have cascading negative consequences for the entire system.
Disarming the mustard oil bomb
Authors: Ratzka Andreas , Vogel Heiko , Kliebenstein Daniel J. , Mitchell-Olds Thomas , Kroymann Juergen
Published: September 2002

Plants are attacked by a broad array of herbivores and pathogens. In response, plants deploy an arsenal of defensive traits. In Brassicaceae, the glucosinolate–myrosinase complex is a sophisticated two-component system to ward off opponents. However, this so-called “mustard oil bomb” is disarmed by a glucosinolate sulfatase of a crucifer specialist insect, diamondback moth,
Plutella xylostella
(Lepidoptera: Plutellidae). Sulfatase activity of this enzyme largely prevents the formation of toxic hydrolysis products arising from this plant defense system. Importantly, the enzyme acts on all major classes of glucosinolates, thus enabling diamondback moths to use a broad range of cruciferous host plants.
Cosolvent-induced transformation of a death domain tertiary structure
Authors: Xiao Tsan , Gardner Kevin H. , Sprang Stephen R.
Published: September 2002

The death domain (DD) of the protein kinase Pelle adopts a six-helix bundle fold in the crystal structure of the complex with its dimerization partner, Tube-DD. However, in crystals obtained from a solution of 45% 2-methyl-2,4-pentanediol (MPD), the C-terminal half of Pelle-DD folds into a single helix, and the N-terminal half of the molecule is disordered. The helical segment forms an antiparallel dimer with the corresponding helix of a symmetry-related molecule, and together they form extensive lattice interactions similar in number, composition, and buried surface to those in the six-helix bundle of the native fold. Secondary structure analysis by heteronuclear nuclear magnetic resonance spectroscopy (NMR) demonstrates that Pelle-DD adopts a six-helix bundle fold in aqueous solution. The fold is perturbed by MPD, with the largest chemical shift changes in one helix and two loop regions that encompass the Tube-DD binding site. Pelle-DD is stable to urea denaturation with a folding free energy of 7.9 kcal/mol at 25°C but is destabilized, with loss of urea binding sites, in the presence of MPD. The data are consistent with a cosolvent denaturation model in which MPD denatures the N terminus of Pelle-DD but induces the C terminus to form a more compact structure and aggregate. A similar perturbation
in vivo
might occur at the plasma membrane and could have consequences for Pelle-mediated regulation. Generally, crystallographers should be aware that high concentrations of MPD or related cosolvents can alter the tertiary structure of susceptible proteins.
Two distinct modes of RecA action are required for DNA polymerase V-catalyzed translesion synthesis
Authors: Pham Phuong , Seitz Erica M. , Saveliev Sergei , Shen Xuan , Woodgate Roger , Cox Michael M. , Goodman Myron F.
Published: September 2002

SOS mutagenesis in
Escherichia coli
requires DNA polymerase V (pol V) and RecA protein to copy damaged DNA templates. Here we show that two distinct biochemical modes for RecA protein are necessary for pol V-catalyzed translesion synthesis. One RecA mode is characterized by a strong stimulation in nucleotide incorporation either directly opposite a lesion or at undamaged template sites, but by the absence of lesion bypass. A separate RecA mode is necessary for translesion synthesis. The RecA1730 mutant protein, which was identified on the basis of its inability to promote pol V (UmuD′
2
C)-dependent UV-mutagenesis, appears proficient for the first mode of RecA action but is deficient in the second mode. Data are presented suggesting that the two RecA modes are “nonfilamentous”. That is, contrary to current models for SOS mutagenesis, formation of a RecA nucleoprotein filament may not be required for copying damaged DNA templates. Instead, SOS mutagenesis occurs when pol V interacts with two RecA molecules, first at a 3′ primer end, upstream of a template lesion, where RecA mode 1 stimulates pol V activity, and subsequently at a site immediately downstream of the lesion, where RecA mode 2 cocatalyzes lesion bypass. We posit that
in vivo
assembly of a RecA nucleoprotein filament may be required principally to target pol V to a site of DNA damage and to stabilize the pol V-RecA interaction at the lesion. However, it is only a RecA molecule located at the 3′ filament tip, proximal to a damaged template base, that is directly responsible for translesion synthesis.
Are
Pfiesteria
species toxicogenic? Evidence against production of ichthyotoxins by
Pfiesteria
shumwayae
Authors: Berry J. P. , Reece K. S. , Rein K. S. , Baden D. G. , Haas L. W. , Ribeiro W. L. , Shields J. D. , Snyder R. V. , Vogelbein W. K. , Gawley R. E.
Published: September 2002

The estuarine genus
Pfiesteria
has received considerable attention since it was first identified and proposed to be the causative agent of fish kills along the mid-Atlantic coast in 1992. The presumption has been that the mechanism of fish death is by release of one or more toxins by the dinoflagellate. In this report, we challenge the notion that
Pfiesteria
species produce ichthyotoxins. Specifically, we show that (
i
) simple centrifugation, with and without ultrasonication, is sufficient to “detoxify” water of actively fish-killing cultures of
Pfiesteria shumwayae
, (
ii
) organic extracts of lyophilized cultures are not toxic to fish, (
iii
) degenerate primers that amplify
PKS
genes from several polyketide-producing dinoflagellates failed to yield a product with
P. shumwayae
DNA or cDNA, and (
iv
) degenerate primers for
NRPS
genes failed to amplify any
NRPS
genes but (unexpectedly) yielded a band (among several) that corresponded to known or putative
PKS
s and fatty acid synthases. We conclude that
P. shumwayae
is able to kill fish by means other than releasing a toxin into bulk water. Alternative explanations of the effects attributed to
Pfiesteria
are suggested.
Potent neutralization of botulinum neurotoxin by recombinant oligoclonal antibody
Authors: Nowakowski A. , Wang C. , Powers D. B. , Amersdorfer P. , Smith T. J. , Montgomery V. A. , Sheridan R. , Blake R. , Smith L. A. , Marks J. D.
Published: September 2002

The botulinum neurotoxins (BoNTs) cause the paralytic human disease botulism and are one of the highest-risk threat agents for bioterrorism. To generate a pharmaceutical to prevent or treat botulism, monoclonal antibodies (mAbs) were generated by phage display and evaluated for neutralization of BoNT serotype A (BoNT/A)in vivo. Although no single mAb significantly neutralized toxin, a combination of three mAbs (oligoclonal Ab) neutralized 450,000 50% lethal doses of BoNT/A, a potency 90 times greater than human hyperimmune globulin. The potency of oligoclonal Ab was primarily due to a large increase in functional Ab binding affinity. The results indicate that the potency of the polyclonal humoral immune response can be deconvoluted to a few mAbs binding nonoverlapping epitopes, providing a route to drugs for preventing and treating botulism and diseases caused by other pathogens and biologic threat agents.
Peptide linkage mapping of the
Agrobacterium tumefaciens vir
-encoded type IV secretion system reveals protein subassemblies
Authors: Ward Doyle V. , Draper Olga , Zupan John R. , Zambryski Patricia C.
Published: September 2002

Numerous bacterial pathogens use type IV secretion systems (T4SS) to deliver virulence factors directly to the cytoplasm of plant, animal, and human host cells. Here, evidence for interactions among components of the
Agrobacterium tumefaciens vir
-encoded T4SS is presented. The results derive from a high-resolution yeast two-hybrid assay, in which a library of small peptide domains of T4SS components was screened for interactions. The use of small peptides overcomes problems associated with assaying for interactions involving membrane-associated proteins. We established interactions between VirB11 (an inner membrane pore-forming protein), VirB9 (a periplasmic protein), and VirB7 (an outer membrane-associated lipoprotein and putative pilus component). We provide evidence for an interaction pathway, among conserved members of a T4SS, spanning the
A. tumefaciens
envelope and including a potential pore protein. In addition, we have determined interactions between VirB1 (a lytic transglycosylase likely involved in the local remodeling of the peptidoglycan) and primarily VirB8, but also VirB4, VirB10, and VirB11 (proteins likely to assemble the core structure of the T4SS). VirB4 interacts with VirB8, VirB10, and VirB11, also establishing a connection to the core components. The identification of these interactions suggests a model for assembly of the T4SS.
Detergent extraction identifies different VirB protein subassemblies of the type IV secretion machinery in the membranes of
Agrobacterium
tumefaciens
Authors: Krall Lilian , Wiedemann Urs , Unsin Gabriele , Weiss Sabine , Domke Natalie , Baron Christian
Published: September 2002

The VirB/D4 type IV secretion system of
Agrobacterium tumefaciens
translocates virulence factors (VirE2, VirF, and the VirD2-T-DNA complex) to plant cells. The membrane-bound translocation machinery consists of 12 proteins (VirB1–11 and VirD4) required for substrate translocation. Protein–protein interactions in the membranes were analyzed after extraction with the mild detergent dodecyl-β-
d
-maltoside followed by separation under native conditions. Incubation of the membranes with increasing concentrations of the detergent differentially extracted virulence proteins. Separation of the solubilized proteins by blue native electrophoresis revealed cofractionation between two classes of protein complexes containing VirB7. The first class, consisting of major T-pilus component VirB2 and associated proteins VirB5 and VirB7, comigrated in the low molecular mass portion of the gel of about 100 kDa. The second class contains putative translocation complex core components VirB8, VirB9, and VirB10 in the high molecular mass portion of the gel larger than 232 kDa, as well as VirB7. Solubilized proteins were characterized further by gel filtration chromatography. This procedure separated T-pilus-associated proteins VirB2, VirB5, and VirB7 in the low molecular mass range from the other components of the translocation machinery and the substrates VirE2 and VirD2. Fractionation of VirB7-containing complexes (VirB7-VirB7 homodimers and VirB7-VirB9 heterodimers) suggested that they may link the T-pilus components to the core of the translocation machinery. Based on previously described VirB protein interactions and biochemical analysis of C58 wild type as well as of
virB5
and
virB6
deletion mutants, a model of T-pilus assembly in
A. tumefaciens
is suggested.
Interchain vs. intrachain energy transfer in acceptor-capped conjugated polymers
Authors: Beljonne D. , Pourtois G. , Silva C. , Hennebicq E. , Herz L. M. , Friend R. H. , Scholes G. D. , Setayesh S. , Müllen K. , Brédas J. L.
Published: September 2002

The energy-transfer processes taking place in conjugated polymers are investigated by means of ultrafast spectroscopy and correlated quantum-chemical calculations applied to polyindenofluorenes end-capped with a perylene derivative. Comparison between the time-integrated luminescence and transient absorption spectra measured in solution and in films allows disentangling of the contributions arising from intrachain and from interchain energy-migration phenomena. Intrachain processes dominate in solution where photoexcitation of the polyindenofluorene units induces a rather slow energy transfer to the perylene end moieties. In films, close contacts between chains favors interchain transport of the excited singlet species (from the conjugated bridge of one chain to the perylene unit of a neighboring one); this process is characterized by a 1-order-of-magnitude increase in transfer rate with respect to solution. This description is supported fully by the results of quantum-chemical calculations that go beyond the usual point-dipole model approximation and account for geometric relaxation phenomena in the excited state before energy migration. The calculations indicate a two-step mechanism for intrachain energy transfer with hopping along the conjugated chains as the rate-limiting step; the higher efficiency of the interchain transfer process is mainly due to larger electronic coupling matrix elements between closely lying chains.
Oligonucleotide directed misfolding of RNA inhibits
Candida albicans
group I intron splicing
Authors: Childs Jessica L. , Disney Matthew D. , Turner Douglas H.
Published: September 2002

RNA is becoming an important therapeutic target. Many potential RNA targets require secondary or tertiary structure for function. Examples include ribosomal RNAs, RNase P RNAs, mRNAs with untranslated regions that regulate translation, and group I and group II introns. Here, a method is described to inhibit RNA function by exploiting the propensity of RNA to adopt multiple folded states that are of similar free energy. This method, called oligonucleotide directed misfolding of RNA (ODMiR), uses short oligonucleotides to stabilize inactive structures. The ODMiR method is demonstrated with the group I intron from
Candida albicans
, a human pathogen. The oligonucleotides,
L
(TACCTTTC) and T
L
CT
L
AC
L
GA
L
CG
L
GC
L
C, with L denoting a locked nucleic acid residue, inhibit 50% of group I intron splicing in a transcription mixture at about 150 and 30 nM oligonucleotide concentration, respectively. Both oligonucleotides induce misfolds as determined by native gel electrophoresis and diethyl pyrocarbonate modification. The ODMiR approach provides a potential therapeutic strategy applicable to RNAs with secondary or tertiary structures required for function.
Adverse effects of acid rain on the distribution of the Wood ThrushHylocichla mustelinain North America
Authors: Hames Ralph S. , Rosenberg Kenneth V. , Lowe James D. , Barker Sara E. , Dhondt André A.
Published: September 2002

Research into population declines of North American bird species has mainly focused on the fragmentation of habitat on the breeding or wintering grounds [Robinson, S. K., Thompson, F. R., Donovan, T. M., Whitehead, D. R. & Faaborg, J. (1995)Science267, 1987–1990]. In contrast, research into declines of European species has mainly focused on intensification of agriculture [Donald, P. F., Green, R. E. & Heath, M. F. (2001)Proc. R. Soc. London Ser. B268, 25–29] and the role played by the atmospheric deposition of pollutants, in particular, acid rain [Graveland, J. (1998)Environ. Rev.6, 41–54]. However, despite widespread unexplained declines of bird populations in regions of heavy wet acid ion deposition [Sauer, J. R., Hines, J. E. & Fallon, J. (2001)The North American Breeding Bird Survey Results and Analysis 1966–2000(Patuxent Wildlife Research Center, Laurel, MD)], no North American studies have presented evidence linking such widespread terrestrial bird declines to acid rain. To address the question of the role played by acid rain in population declines of eastern North American songbird species, we combine data from several sources. We use a multiple logistic regression model to test for adverse effects of acid rain on the Wood Thrush, while controlling for regional abundance, landscape-level habitat fragmentation, elevation, soil pH, and vegetation. We show a strong, highly significant, negative effect of acid rain on the predicted probability of breeding by this species, and interactions with elevation, low pH soils, and habitat fragmentation that worsen these negative effects. Our results suggest an important role for acid rain in recent declines of some birds breeding in the eastern United States, particularly in high elevation zones with low pH soils, and show the need to consider other large-scale influences, in addition to habitat fragmentation, when addressing bird population declines.
Phospholemman (FXYD1) associates with Na,K-ATPase and regulates its transport properties
Authors: Crambert Gilles , Füzesi Maria , Garty Haim , Karlish Steven , Geering Käthi
Published: September 2002

A family of small, single-span membrane proteins (the FXYD family) has recently been defined based on their sequence and structural homology. Some members of this family have already been identified as tissue-specific regulators of Na,K-ATPase (NKA). In the present study, we demonstrate that phospholemman (PLM) (FXYD1), so far considered to be a heart- and muscle-specific channel or channel-regulating protein, associates specifically and stably with six different α-β isozymes of NKA after coexpression in
Xenopus
oocytes, and with α1–β, and less efficiently with α2–β isozymes, in native cardiac and skeletal muscles. Stoichiometric association of PLM with NKA occurs posttranslationally either in the Golgi or the plasma membrane. Interaction of PLM with NKA induces a small decrease in the external K
+
affinity of α1–β1 and α2–β1 isozymes and a nearly 2-fold decrease in the internal Na
+
affinity. In conclusion, this study demonstrates that PLM is a tissue-specific regulator of NKA that may play an essential role in muscle contractility.
Bringing up adolescent children: A longitudinal study of parents’ child-rearing stress
Authors: Seginer Rachel , Vermulst Ad , Gerris Jan
Published: September 2002

This study presents a longitudinal child-rearing stress model for adolescents’ parents. The model depicts the indirect associations between parental antecedents (physical strain and perceived problematic child behaviour) and adolescent outcomes (emotional stability, positive outlook for the future, reported by adolescents), via adolescents’ perceptions of parent-adolescent positive relationship. Empirical estimates of the model were carried out by LISREL analyses of data collected from 369 Dutch families and their 208 adolescent daughters and 161 sons, at two time-points (T1, T2) five years apart. Analyses indicated a good fit between the theoretical model and its estimates for four family dyads (mother-girl, mother-boy, father-girl, father-boy). Parents’ sex differences were dependent on sex of child, and the empirical estimates explained a larger percentage of the variance of positive outlook for the future of girls than of boys. In addition, fathers’ reports regarding problematic child behaviour at T1 were directly linked to girls’ outcomes. Discussion focuses on the stability of child-rearing stress, the pivotal role of adolescent-parent relationship, and sex-of-parent by sex-of-adolescent-child differences.
Commonalities and differences in close relationships among the Americans and Japanese: A comparison by the individualism/collectivism concept
Authors: Takahashi Keiko , Ohara Naomi , Antonucci Toni C. , Akiyama Hiroko
Published: September 2002

We examined commonalities and differences of close relationships among the Americans and Japanese by using three major propositions extracted from the individualism/collectivism concept. Responses to three kinds of social relationship scales, i.e., affective, instrumental, and conflict, were compared. Americans ( N = 547) and Japanese ( N = 808) of 20 to 64 years of age rated at least four significant others out of five, i.e., mother, father, partner/spouse, a child, and same-gender friend. Findings obtained by three kinds of comparisons—(1) mean scores; (2) correlation patterns; and (3) the dominant figures—indicated both commonalities and differences across the cultures. Whereas nearly half of the working hypotheses based on the three propositions derived from the individualism/collectivism concept were supported by the data, others revealed differences in the opposite direction. It is discussed that the individualism/collectivism framework may be a useful tool for cross-cultural comparisons, but not a theory or model of the Western and Eastern cultures.
Winning friends and influencing peers: Strategies of peer influence in late childhood
Authors: Hawley Patricia H. , Little Todd D. , Pasupathi Monisha
Published: September 2002

We divided children ( N = 719, grades 3–6) into five control types based on the degree to which they reported employing prosocial (indirect, cooperative) and coercive (direct, hostile) strategies of control (prosocial controllers, coercive controllers, bistrategic controllers, noncontrollers, and typicals). We tested for differences across the five types on personal characteristics, friendship motivations, wellbeing, and social integration, expecting specific patterns according to whether control is wielded, and whether coercive or prosocial behaviour (or both) is employed. Prosocial controllers revealed positive characteristics (e.g., social skills, agreeableness), intrinsic friendship motivations, and positive wellbeing. In contrast, coercive controllers revealed negative characteristics (e.g., hostility), extrinsic friendship motivations, and ill-being. Bistrategic controllers, as expected, reported the highest control, and revealed characteristics associated with both prosocial and coercive orientations. Noncontrollers, in contrast, did not report having these characteristics and felt the least effective in the peer group. Our evolutionary perspective offers unique predictions of how prosocial and coercive children are similar in terms of their instrumental goals and the consequences of using both strategies or neither.
Information Technology and Ideology
Authors: Saravanamuthu Kala
Published: September 2002

The scientific origin of information technology (IT) does not make it a neutral witness to the ongoing struggle over how scarce resources are used for generating more wealth. This paper argues that the manner in which the technology is used for capturing, reporting and disseminating information reflects the underlying dialectic of control among competing organizational stakeholders as they contest the logic of capitalist priorities. IT's politically intrusive role in the struggle for control is discussed through a critique of a people-oriented information system methodology, Multiview 2, which fails to problematize the struggle over workplace ideology. The paper highlights the significance of this shortcoming by analysing capital's ideological use of business process re-engineering for gaining workers’ consent to their own exploitation. This 1990s’ innovation portrays the subjugation of social interests in favour of the relentless pursuit of profit as a coherent social approach to transforming labour relations. In conclusion, it is proposed that IT's social role should be an emancipatory one, which, given the competitive-interdependent context of work, should facilitate the emergence of multiple worldviews.
The Internet and the Consumer: Countervailing Power Revisited
Authors: Rha Jong-Youn , Widdows Richard
Published: September 2002

The Internet is a tool with the potential to enable consumers to effectively participate in collective bargaining in the marketplace. The purpose of this paper is to address the viability of the concept of countervailing power in the Internet era. First, some theoretical perspectives on how on-line consumer networks have the potential to be a new source of countervailing power are introduced. Next, the potential for consumer countervailing power in the Internet era is discussed. A case study that illustrates the viability of the propositions is then presented. Finally, implications and limitations of the paper are briefly discussed: if the potential for countervailing power can be established, then the circumstances under which collective bargaining would occur and the determinants of its outcome would be of vital interest to consumer economists and policy makers.
Australian University-Industry Research Links: Researcher Involvement, Outputs, Personal Benefits and 'Withholding' Behaviour
Authors: Harman Grant
Published: September 2002

Using data from two surveys of science and technology academics in major Australian research universities, an assessment is made of researcher involvement in industry-research partnerships, the outputs and personal benefits that result, and the occurrence of delaying publications and withholding data and materials from colleagues. An estimated 40% of academics currently have industry research funding, with many also having other sources of funding. Some 60% of respondents with industry funding have attracted individually, or within a research group, funding of more than $250,000 over the past three years. About 35% of principal investigators with industry funding have total annual research budgets of over $101,000. While about 20% of academics have produced research results of commercial value, most of these have been less successful in increasing their personal incomes through research commercialisation and consulting, and equity in companies. Almost 40% with industry funding report having conducted research where the results are the property of a sponsor and cannot be published for a period without consent. Almost 20% of academics in 1997 and just over 20% in 2000 admitted having delayed publications for more than six months. However, safeguarding the researcher's self-interest appears to be as common a motive for delaying publication or failing to share research results or materials with scientific colleagues as protecting the property of a sponsor.
Globalization isn't New; Anti-globalization isn't Either: September 11 and the History of Nations
Authors: Carey James W.
Published: September 2002

The September 11 attack on the Pentagon and the World Trade Center reveals, among other things, a colossal failure of intelligence and radical deficiencies in our understanding of communications in the modern world. The history of nations and the history of communications are continuous, though contradictory, since the eighteenth century, and those continuities and contradictions are revealed by way of analysis of September 11 and its aftermath.
The Telephone as a Medium of Faith, Hope, Terror, and Redemption: America, September 11
Authors: Katz James E. , Rice Ronald E.
Published: September 2002

This article explores how ordinary people used telephone technology during the September 11, 2001 terrorist attacks on the USA. Personal emergency communication is heavily imbued with emotional meaning. These messages address major life problems and values, such as leaving final messages and expressing love and concern, sometimes requiring extreme efforts. They also show that formal technical characteristics of media, and boundaries across media, are not particularly salient to people who have pressing personal and social communication needs.
Involvement of Macrophages in the Pathogenesis of Transmissible Spongiform Encephalopathies
Authors: Beringue Vincent , Couvreur Patrick , Dormont Dominique
Published: September 2002

Although transmissible spongiform encephalopathies (TSE) or prion diseases are neurodegenerative disorders, the immune system is also involved, at least in the early stages of their pathogenesis. Extensive studies have focused on cells targeted by the TSE agent for its replication but few on the possible involvement of macrophages in its clearance, as in more conventional diseases. This review summarises some of the experiments aimed at demonstrating a role for macrophages in TSE and presents the application to TSE of the macrophage "suicide" technique, which has been used to clarify the implication of these cells in the early steps of TSE pathogenesis.
Low‐power Application‐specific Parallel Array Multiplier Design for DSP Applications
Authors: Hong Sangjin , Kim Suhwan , Stark Wayne E.
Published: September 2002

Digital Signal Processing (DSP) often involves multiplications with a fixed set of coefficients. This paper presents a novel multiplier design methodology for performing these coefficient multiplications with very low power dissipation. Given bounds on the throughput and the quantization error of the computation, our approach scales the original coefficients to enable the partitioning of each multiplication into a collection of smaller multiplications with shorter critical paths. Significant energy savings are achieved by performing these multiplications in parallel with a scaled supply voltage. Dissipation is further reduced when conventional array multiplier is modified disabling the multiplier rows that do not affect the multiplication′s outcome. We have used our methodology to design low‐power parallel array multipliers for the Fast Fourier Transform (FFT). Simulation results show that our approach can result in significant up to 76% power savings over conventional array multipliers on 64‐coefficient FFT computation.
Welfare States And Dimensions Of Social Capital: Cross-national Comparisons Of Social Contacts In European Countries
Authors: Scheepers Peer , Grotenhuis Manfred Te , Gelissen John
Published: September 2002

We set out to describe and explain differences in the amount of some dimensions of social capital within and between European societies. Social capital refers to a wide range of social phenomena; however, we focus on social contacts with family and friends. We derive hypotheses about cross-national differences in social capital from theories on the nature of welfare state regimes. We test these hypotheses with multi-level analyses on Eurobarometer data, collected in thirteen countries. We find significant variance across different countries. This variance is partly explained by individual characteristics: religious people and people living in medium-sized or rural towns have more social contacts. Moreover, we find quite differential effects of other individual characteristics on social contacts and no effects of political stances. Differences in the cross-national compositions in educational attainment and household size also account for the variance in social contacts. Finally, people living in social-democratic regimes turn out to have the smallest amount of social contacts, whereas people living in the Latin Rim have the largest amount. In between, we find people living in liberal, respectively, conservative-corporatist regimes. This explanation is opposed to the hypothesis that it is the difference in social security rates that causes differences in social capital.
Cumulative Disadvantage Or Individualisation?: A Comparative Analysis Of Poverty Risk And Incidence
Authors: Layte Richard , Whelan Christopher T.
Published: September 2002

In this paper we seek to clarify and examine empirically two related perspectives on poverty processes that have emerged in recent years - those of cumulative disadvantage and of individualisation . The cumulative disadvantage perspective defines the key cleavage as between a comfortable majority and a multiply disadvantaged minority excluded from the mainstream. The individualisation perspective on the other hand views poverty as a relatively transient phenomenon, which is largely independent of traditional stratification factors. Our analyses support neither the over-determination of poverty risk through cumulative disadvantage, nor the under-determination through individualisation. Instead we argue that traditional risk factors are important, but combine in complicated ways to put a larger proportion of the population at risk of poverty rather than impacting solely on a multiply disadvantaged minority. A crucial implication of this paper is that highly targeted policies aimed at multiply deprived groups will be less successful at combating poverty than more generalised responses directed at groups who are not necessarily currently poor, but whose vulnerability to such exposure means that a range of factors may precipitate such an outcome.
De novo formation of centrosomes in vertebrate cells arrested during S phase
Authors: Khodjakov Alexey , Rieder Conly L. , Sluder Greenfield , Cassels Grisel , Sibon Ody , Wang Chuo-Lung
Published: September 2002

The centrosome usually replicates in a semiconservative fashion, i.e., new centrioles form in association with preexisting “maternal” centrioles. De novo formation of centrioles has been reported for a few highly specialized cell types but it has not been seen in vertebrate somatic cells. We find that when centrosomes are completely destroyed by laser microsurgery in CHO cells arrested in S phase by hydroxyurea, new centrosomes form by de novo assembly. Formation of new centrosomes occurs in two steps: ∼5–8 h after ablation, clouds of pericentriolar material (PCM) containing γ-tubulin and pericentrin appear in the cell. By 24 h, centrioles have formed inside of already well-developed PCM clouds. This de novo pathway leads to the formation of a random number of centrioles (2–14 per cell). Although clouds of PCM consistently form even when microtubules are completely disassembled by nocodazole, the centrioles are not assembled under these conditions.
CD40, an extracellular receptor for binding and uptake of Hsp70–peptide complexes
Authors: Becker Thalia , Hartl F.-Ulrich , Wieland Felix
Published: September 2002

Tumor and viral antigens elicit a potent immune response by heat shock protein–dependent uptake of antigenic peptide with subsequent presentation by MHC I. Receptors on antigen-presenting cells that specifically bind and internalize a heat shock protein–peptide complex have not yet been identified. Here, we show that cells expressing CD40, a cell surface protein crucial for B cell function and autoimmunity, specifically bind and internalize human Hsp70 with bound peptide. Binding of Hsp70–peptide complex to the exoplasmic domain of CD40 is mediated by the NH2-terminal nucleotide–binding domain of Hsp70 in its ADP state. The Hsp70 cochaperone Hip, but not the bacterial Hsp70 homologue DnaK, competes formation of the Hsp70–CD40 complex. Binding of Hsp70-ADP to CD40 is strongly increased in the presence of Hsp70 peptide substrate, and induces signaling via p38. We suggest that CD40 is a cochaperone-like receptor mediating the uptake of exogenous Hsp70–peptide complexes by macrophages and dendritic cells.
Genetic Dissection of SLE
Authors: Shi Xiaoyan , Xie Chun , Kreska Desi , Richardson James A. , Mohan Chandra
Published: September 2002

Genetic dissection of lupus pathogenesis in the NZM2410 strain has recently revealed that Sle1 is a potent locus that triggers the formation of IgG anti-histone/DNA antibodies, when expressed on the B6 background as a congenic interval. B6.lpr mice, in contrast, exhibit distinctly different cellular and serological phenotypes. Both strains, however, do not usually exhibit pathogenic autoantibodies, or succumb to lupus nephritis. In this study, we show that the epistatic interaction of Sle1 (in particular, Sle1/Sle1) with FASlpr leads to massive lymphosplenomegaly (with elevated numbers of activated CD4 T cells, CD4−CD8− double negative (DN) T cells, and B1a cells), high levels of IgG and IgM antinuclear (including anti-ssDNA, anti-dsDNA, and anti-histone/DNA), and antiglomerular autoantibodies, histological, and clinical evidence of glomerulonephritis, and >80% mortality by 5–6 mo of age. Whereas FASlpr functions as a recessive gene, Sle1 exhibits a gene dosage effect. These studies indicate that Sle1 and FASlpr must be impacting alternate pathways leading to lymphoproliferative autoimmunity.
Pancreatic Lymph Nodes Are Required for Priming of β Cell Reactive T Cells in NOD Mice
Authors: Gagnerault Marie-Claude , Luan Jian Jian , Lotton Chantal , Lepault Françoise
Published: September 2002

Nonobese diabetic (NOD) mice develop spontaneous autoimmune diabetes that results from the destruction of insulin secreting β cells by diabetogenic T cells. The time and location of the encounter of autoantigen(s) by naive autoreactive T cells in normal NOD mice are still elusive. To address these issues, we analyzed diabetes development in mice whose spleen or pancreatic lymph nodes (panLNs) had been removed. Excision of panLNs (panLNx) at 3 wk protected mice against insulin autoantibodies (IAAs), insulitis, and diabetes development almost completely, but had no effect when performed at 10 wk. The protection afforded by panLNx at weaning was not due to modifications of the immune system, the absence of autoreactive T cells, or the increase in the potency of regulatory T cells. That panLNs are dispensable during adult life was confirmed by the capacity of 10-wk-old panLNx irradiated recipients to develop diabetes upon transfer of diabetogenic T cells. In contrast, splenectomy had no effect at any age. Partial excision of mesenteric LN at 3 wk did not prevent accelerated diabetes by cyclophosphamide as panLNx did. Thus, in normal NOD mice, autoreactive T cell initial priming occurs in LNs draining the target organ of the disease from 3 wk of age.
Inhibition of Allogeneic T Cell Proliferation by Indoleamine 2,3-Dioxygenase–expressing Dendritic Cells
Authors: Terness Peter , Bauer Thomas M. , Röse Lars , Dufter Christoph , Watzlik Andrea , Simon Helmut , Opelz Gerhard
Published: September 2002

Indoleamine 2,3-dioxygenase (IDO), an enzyme involved in the catabolism of tryptophan, is expressed in certain cells and tissues, particularly in antigen-presenting cells of lymphoid organs and in the placenta. It was shown that IDO prevents rejection of the fetus during pregnancy, probably by inhibiting alloreactive T cells, and it was suggested that IDO-expression in antigen-presenting cells may control autoreactive immune responses. Degradation of tryptophan, an essential amino acid required for cell proliferation, was reported to be the mechanism of IDO-induced T cell suppression. Because we wanted to study the action of IDO-expressing dendritic cells (DCs) on allogeneic T cells, the human IDO gene was inserted into an adenoviral vector and expressed in DCs. Transgenic DCs decreased the concentration of tryptophan, increased the concentration of kynurenine, the main tryptophan metabolite, and suppressed allogeneic T cell proliferation in vitro. Kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid, but no other IDO-induced tryptophan metabolites, suppressed the T cell response, the suppressive effects being additive. T cells, once stopped in their proliferation, could not be restimulated. Inhibition of proliferation was likely due to T cell death because suppressive tryptophan catabolites exerted a cytotoxic action on CD3+ cells. This action preferentially affected activated T cells and increased gradually with exposure time. In addition to T cells, B and natural killer (NK) cells were also killed, whereas DCs were not affected. Our findings shed light on suppressive mechanisms mediated by DCs and provide an explanation for important biological processes in which IDO activity apparently is increased, such as protection of the fetus from rejection during pregnancy and possibly T cell death in HIV-infected patients.