bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced field emission of thin multiwall carbon nanotubes by electron multiplication from microchannel plate
Authors: Seelaboyina Raghunandan , Huang Jun , Choi Won Bong
Published: May 2006

We report on a method to amplify electron emission from thin multiwall carbon nanotube (MWCNTs) field emitters using an electron multiplier microchannel plate. High density thin MWCNTs were synthesized by thermal chemical vapor deposition. Density of thin MWCNTs was increased by decreasing the amount of Al2O3 in the catalyst solution. The high density of nanotubes led to their vertical orientation. The thin MWCNTs showed low turn-on electric field and high electron emissivity which could be attributed to their wall thinness and high aspect ratio (∼1500) resulting in high field enhancement factor (∼9300). Emission current was stable with an average fluctuation of 2%. A microchannel plate positioned between cathode and anode increased the total emission current by 7.5 times.
Aging effects in pentacene thin-film transistors: Analysis of the density of states modification
Authors: De Angelis F. , Cipolloni S. , Mariucci L. , Fortunato G.
Published: May 2006

Field effect analysis has been employed in order to calculate the density of states of high quality pentacene thin-film transistors. The degradation of the electrical characteristics caused by the exposure to air has been studied and discussed in term of density of states modification. The calculated density of the states has been approximated by two exponential terms, as in amorphous silicon, and it has been used in a two-dimensional numerical simulation in order to reproduce the electrical characteristic variation with respect of the temperature and aging time.
Behavior of elemental tellurium as surface generation-recombination centers in CdTe∕HgCdTe interface
Authors: Lee Min Yung , Lee Yong Soo , Lee Hee Chul
Published: May 2006

Calculated chemical equations using thermodynamics suggest that elemental Te0 is easily induced during bromine-based etching process on the HgCdTe surface and the induced elemental Te0 can be removed by chemical reaction with hydrazine, forming volatile H2Te. X-ray photoelectron spectroscopy (XPS) confirmed these chemical reactions. The induced elemental Te0 is believed to play a role as surface generation-recombination centers in CdTe∕HgCdTe interface, which was confirmed by XPS, ideality factor, and energy-dispersive interface trap density (Dit) analyses.
Direct tip-sample interaction force control for the dynamic mode atomic force microscopy
Authors: Jeong Younkoo , Jayanth G. R. , Jhiang Sissy M. , Menq Chia-Hsiang
Published: May 2006

A control method, in which the tip-sample interaction force of each tapping cycle is directly regulated, is proposed for dynamic mode atomic force microscopy. It does not rely on the steady-state relationship between the cantilever’s oscillation amplitude and tip-to-sample distance, and therefore the cantilever’s transient dynamics and the time delay of rms-dc converter are irrelevant. Experimental results clearly demonstrate that the proposed method regulates the tip-sample interaction force for each tapping cycle and time delay effect is eliminated. Computer simulations also show that the proposed method reconstructs a step change in topography within two tapping cycles, independent of the cantilever’s transient dynamics.
Electrical observations of filamentary conductions for the resistive memory switching in NiO films
Authors: Kim D. C. , Seo S. , Ahn S. E. , Suh D.-S. , Lee M. J. , Park B.-H. , Yoo I. K. , Baek I. G. , Kim H.-J. , Yim E. K. , Lee J. E. , Park S. O. , Kim H. S. , Chung U-In , Moon J. T. , Ryu B. I.
Published: May 2006

Experimental results on the bistable resistive memory switching in submicron sized NiO memory cells are presented. By using a current-bias method, intermediate resistance states and anomalous resistance fluctuations between resistance states are observed during the resistive transition from high resistance state to low resistance state. They are interpreted to be associated with filamentary conducting paths with their formation and rupture for the memory switching origin in NiO. The experimental results are discussed on the basis of filamentary conductions in consideration of local Joule heating effect.
Assessment of contamination of wool by dark and medullated fibres using near infrared spectroscopy
Authors: Fleet M. R. , Li L. , Ru Y.
Published: May 2006

Increased crossbreeding of Merino sheep in Australia, involving coloured or highly medullated sire breeds, has increased the risk of dark and highly medullated fibres in wool lots. Commercial implementation of the Dark and Medullated Fibre Risk Scheme, based on producer information, is identifying to buyers some of these risks and technology is sought to provide an inexpensive method for routine presale testing of greasy wool lots. One measurement concept assessed the ability of near infrared spectroscopy (NIRS) to predict variation in levels of pigmented fibres or highly medullated fibres in wool. The project used either ‘seeded’ wool samples or naturally contaminated samples with measured reference values as well as different methods of sample preparation of wool fibre (in air or immersed in benzyl alcohol) or the solutions from alkali hydrolysis of wool fibre and NIRS measurement (reflectance v. transmission). NIRS can predict variation in trace levels of pigmented fibre or highly medullated white fibres (kemp) in wool and, among the methods assessed, reflectance analysis of wool fibre in air was generally better than the other options considered. Calibration models for NIRS reflectance measurement of 5 g wool samples ‘seeded’ with 1–50 black-pigmented, tan-pigmented or white kemp fibres gave coefficients of determination (R2) of 0.96, 0.88 and 0.82 with standard errors of cross-validation (SECV) of 4.34, 6.97 and 7.17 fibres per 5 g sample, respectively. However, these calibration equations generally did not predict variations in the reference values for 3 other sets of naturally contaminated samples. New calibration equations determined for each of the sets of naturally contaminated samples also predicted variation in the pigmented fibre reference values, with the extent of agreement depending on the accuracy of the reference data as well as sample preparation and method of measurement. Calibration models for NIRS reflectance measurement of wool fibre from the 3 sets of naturally contaminated samples produced R2 = 0.99, 0.71 and 0.92 with SECV = 0.923, 6.43 and 4.54 pigmented fibres per 5 g sample, respectively. However, these calibrations and those obtained from various combinations of the wool sets also had limited ability to predict variation in pigmented fibre reference values in other independent or excluded samples. Refinement of the technique and development of calibrations with extensive and reliable reference data, representing all of the wool variation likely to be encountered, may allow this NIRS potential to become relevant in the presale testing of wool as an inexpensive measurement procedure for estimating dark and medullated fibre content.
Tolerance of perennial pasture grass seedlings to pre- and post-emergent grass herbicides
Authors: Dear B. S. , Sandral G. A. , Wilson B. C. D.
Published: May 2006

The tolerance of 5 perennial grasses during the seedling stage to pre- and post-emergent grass herbicides was examined in 3 glasshouse experiments. The perennial grass species screened were phalaris, (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), wallaby grass [Austrodanthonia richardsonii (Cashm.) H.P. Linder], perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.). Wheat (Triticum aestivum L.) and subterranean clover (Trifolium subterraneum L.) were included as non-target species and annual ryegrass (Lolium rigidum Gaudin) and oats (Avena spp.) as representatives of typical weed species. Herbicides evaluated were fluazifop-p, tralkoxydim, diclofop-methyl, fenoxaprop-p-ethyl, fenoxaprop-p-ethyl + pyrazoline, sethoxydim, flamprop-m-methyl, quizalofop-p-ethyl, clethodim, simazine, imazethapyr, propyzamide, carbetamide, clodinafop-propargyl + cloquintocet-mexyl, propaquizafop, atrazine, trifluralin, triallate, pendimethalin, metribuzin, trifluralin + oryzalin, cyanazine, chlorsulfuron and triasulfuron. Herbicide phytotoxicity was assessed 15 and 30 days after post-emergent herbicide application using the European Weed Research Committee (EWRC) visual score of leaf damage (1 indicating no effect, 9 indicating all plants dead) and plant herbage yield depression relative to the unsprayed control. Plant responses to pre-emergent herbicides were assessed 45 days after sowing. Most herbicides were highly phytotoxic (EWRC score 4–9) to the perennial grass seedlings. However, atrazine, flamprop-m-methyl, imazethapyr, fenoxaprop-ethyl, and triallate caused less severe phytotoxicity (EWRC score 1–4) in phalaris, fescue, cocksfoot and perennial ryegrass from which they could be expected to recover, with yield reductions of between 0 and 45%, 30 days after spraying. Simazine caused yield losses of 20–50% in fescue, phalaris and perennial ryegrass which may be acceptable in swards with high weed burdens. Wallaby grass showed tolerance to flamprop-m-methyl, carbetamide, propyzamide and imazethapyr. Subterranean clover was tolerant of most herbicides with yield losses less than 20% except for the post-emergent herbicides simazine and atrazine, and the pre-emergent herbicides triasulfuron, metribuzin, cyanazine and chlorsulfuron where yield suppression was between 50 and 99%.
Oogenesis requires germ cell-specific transcriptional regulators
Sohlh1
and
Lhx8
Authors: Pangas Stephanie A. , Choi Youngsok , Ballow Daniel J. , Zhao Yangu , Westphal Heiner , Matzuk Martin M. , Rajkovic Aleksandar
Published: May 2006

Mammalian oogenesis requires oocyte-specific transcriptional regulators. The full complement of oocyte-specific transcription factors is unknown. Here, we describe the finding that
Sohlh1
, a spermatogenesis and oogenesis basic helix–loop–helix transcription factor in females, is preferentially expressed in oocytes and required for oogenesis.
Sohlh1
disruption perturbs follicular formation in part by causing down-regulation of two genes that are known to disrupt folliculogenesis: newborn ovary homeobox gene (
Nobox
) and factor in the germ-line alpha (
Figla
). In addition, we show that
Lhx8
is downstream of
Sohlh1
and critical in fertility. Thus,
Sohlh1
and
Lhx8
are two germ cell-specific, critical regulators of oogenesis.
Spin glasses and fragile glasses: Statics, dynamics, and complexity
Authors: Parisi Giorgio
Published: May 2006

In this paper I will briefly review some theoretical results that have been obtained in recent years for spin glasses and fragile glasses. I will concentrate my attention on the predictions coming from the so called
broken replica symmetry
approach and on their experimental verifications. I will also mention the relevance or these results for other fields, and in general for
complex systems
.
Counterions between charged polymers exhibit liquid-like organization and dynamics
Authors: Angelini Thomas E. , Golestanian Ramin , Coridan Robert H. , Butler John C. , Beraud Alexandre , Krisch Michael , Sinn Harald , Schweizer Kenneth S. , Wong Gerard C. L.
Published: May 2006

Current understanding of electrostatics in water is based on mean-field theories like the Poisson–Boltzmann formalism and its approximations, which are routinely used in colloid science and computational biology. This approach, however, breaks down for highly charged systems, which exhibit counterintuitive phenomena such as overcharging and like-charge attraction. Models of counterion correlations have been proposed as possible explanations, but no experimental comparisons are available. Here, collective dynamics of counterions that mediate like-charge attraction between F-actin filaments have been directly observed in aqueous solution using high-resolution inelastic x-ray scattering down to molecular length-scales. We find a previously undescribed acoustic-like phonon mode associated with correlated counterions. The excitation spectra at high wave-vector
Q
reveal unexpected dynamics due to ions interacting with their “cages” of nearest neighbors. We examine this behavior in the context of intrinsic charge density variations on F-actin. The measured speed of sound and collective relaxation rates in this liquid agree surprisingly well with simple model calculations.
The callipyge mutation enhances bidirectional long-range
DLK1-GTL2
intergenic transcription in cis
Authors: Takeda Haruko , Caiment Florian , Smit Maria , Hiard Samuel , Tordoir Xavier , Cockett Noelle , Georges Michel , Charlier Carole
Published: May 2006

The callipyge mutation (
CLPG
) is an A to G transition that affects a muscle-specific long-range control element located in the middle of the 90-kb
DLK1-GTL2
intergenic (IG) region. It causes ectopic expression of a 327-kb cluster of imprinted genes in skeletal muscle, resulting in the callipyge muscular hypertrophy and its non-Mendelian inheritance pattern known as polar overdominance. We herein demonstrate that the
CLPG
mutation alters the muscular epigenotype of the
DLK1-GTL2
IG region in cis, including hypomethylation, acquisition of novel DNase-I hypersentivite sites, and, most strikingly, strongly enhanced bidirectional, long-range IG transcription. The callipyge phenotype thus emerges as a unique model to study the functional significance of IG transcription, which recently has proven to be a widespread, yet elusive, feature of the mammalian genome.
'Fixing Broken Promises?': Neighbourhood Wardens and Social Capital
Authors: Crawford Adam
Published: May 2006

This article explores the growing emphasis upon the policing of incivilities and anti-social behaviour, situating this within debates about the role of social capital in the construction and maintenance of social order. It outlines a critique of certain dominant assumptions within debates about social capital, notably with regard to crime and security. Nevertheless, social capital is used as a lens through which to consider some of the questions that confront policing interventions in attempts to promote social order and civic renewal. It suggests that fostering weak social ties, rather than strong bonds of 'togetherness', may be preferable in supporting open and tolerant communities. The article considers the work of neighbourhood wardens and their contribution to fostering social order in deprived neighbourhoods. It draws upon research findings from wardens working in the city of Leeds, highlighting dilemmas regarding their ambiguous roles in relation to community cohesion and policing.
Species and Sex Differences in Susceptibility to Olfactory Lesions Among the Mouse, Rat and Monkey Following an Intravenous Injection of Vincristine Sulphate
Authors: Kai Kiyonori , Sahto Hiroshi , Yoshida Mitsuyoshi , Suzuki Takami , Shikanai Yukari , Kajimura Tetsuyo , Furuhama Kazuhisa
Published: May 2006

Species and sex differences in susceptibility to vincristine sulphate (VCR)-induced olfactory epithelial lesions were investigated among the BALB/c mice, Crj: CD(SD) IGS rats and common marmoset monkeys following a single intravenous administration on day 1. As dosage levels, the 0.17-fold LD10, 0.6-fold LD10and LD10were used for mice and rats, and a maximum tolerated dose (MTD) was chosen only for monkeys. The order of strength of VCR action on peripheral neuropathic signs, body weight gain, and hematological parameters was mice > rats > monkeys, without clear sex differences. Histopathologically, on day 2, single cell death in the olfactory epithelium and vomeronasal organ was observed only in male mice at LD10, and in female mice at 0.6-fold LD10or more. On day 5, the olfactory epithelium in these mice showed regenerative proliferation suggesting a sign of recovery. On day 10, axonopathy and demyelination in the sciatic and trigeminal nerves were noted in mice of both sexes at 0.6-fold LD10or more. In rats and monkeys of either sex, however, no morphological changes were observed at any dose level. In conclusion, mice, particularly females, were shown to be more susceptible to VCR-induced apoptosis in the olfactory epithelium than rats and monkeys.
Small and growth‐restricted babies: Drawing the distinction
Authors: SIFIANOU POPI
Published: May 2006

The terms “small for gestational age” and “intrauterine growth restriction” have been used interchangeably to denote an in utero growth‐restricted neonate. However, the two terms are not synonymous; not all small babies are growth restricted and not all growth‐restricted ones are small. Research evidence, extending back to the middle of the last century, reveals that the number of growth‐restricted babies who escape attention is not negligible and that the postnatal outcome of these babies is not uneventful. This paper highlights this issue and further discusses the available diagnostic tools for the identification of in utero‐restricted neonates, that is, clinical assessment, anthropometric indices and obstetric ultrasound. Each of these tools has strengths and limitations, but, if combined, each could complement the other and help differentiate well‐grown babies from those who are growth restricted.

Conclusion: Identification of growth‐restricted neonates is feasible through the integrated use of diagnostic tools.
SCARNA: fast and accurate structural alignment of RNA sequences by matching fixed-length stem fragments
Authors: Tabei Yasuo , Tsuda Koji , Kin Taishin , Asai Kiyoshi
Published: May 2006

Motivation: The functions of non-coding RNAs are strongly related to their secondary structures, but it is known that a secondary structure prediction of a single sequence is not reliable. Therefore, we have to collect similar RNA sequences with a common secondary structure for the analyses of a new non-coding RNA without knowing the exact secondary structure itself. Therefore, the sequence comparison in searching similar RNAs should consider not only their sequence similarities but also their potential secondary structures. Sankoff's algorithm predicts the common secondary structures of the sequences, but it is computationally too expensive to apply to large-scale analyses. Because we often want to compare a large number of cDNA sequences or to search similar RNAs in the whole genome sequences, much faster algorithms are required.

Results: We propose a new method of comparing RNA sequences based on the structural alignments of the fixed-length fragments of the stem candidates. The implemented software, SCARNA (Stem Candidate Aligner for RNAs), is fast enough to apply to the long sequences in the large-scale analyses. The accuracy of the alignments is better or comparable with the much slower existing algorithms.

Availability: The web server of SCARNA with graphical structural alignment viewer is available at

Contact:  scarna@m.aist.go.jp

Supplementary information: The data and the supplementary information are available at .
Ranging patterns and parasitism in primates
Authors: Nunn Charles L , Dokey Adrian Tae-Won
Published: May 2006

Competing hypotheses exist concerning the influence of ranging patterns on parasitism. More intensive use of a home range could result in greater exposure to infectious agents that accumulate in the soil. Alternatively, when more intensive ranging is associated with territorial defence, this could decrease home range overlap and produce lower levels of parasitism. We tested these hypotheses using phylogenetic comparative methods and parasite richness data for 119 primate species. Helminth richness increased with the defensibility index, a quantitative measure of home range use that correlates with the degree of territoriality in primates. This association was independent of other host traits that influence parasite richness in primates. Results involving non-vector transmitted helminths produced the most significant results, suggesting that the relationship between territorial behaviour and parasitism is driven by accumulation of parasites in defended home ranges. In addition, costs associated with greater ranging could increase susceptibility to infectious agents.
Convergent adaptation to a marginal habitat by homoploid hybrids and polyploid ecads in the seaweed genusFucus
Authors: Coyer James A , Hoarau Galice , Pearson Gareth A , Serrão Ester A , Stam Wytze T , Olsen Jeanine L
Published: May 2006

Hybridization and polyploidy are two major sources of genetic variability that can lead to adaptation in new habitats. Most species of the brown algal genusFucusare found along wave-swept rocky shores of the Northern Hemisphere, but some species have adapted to brackish and salt marsh habitats. Using five microsatellite loci and mtDNA RFLP, we characterize two populations of morphologically similar, muscoides-likeFucusinhabiting salt marshes in Iceland and Ireland. The Icelandic genotypes were consistent withFucus vesiculosus×Fucus spiralisF1hybrids with asymmetrical hybridization, whereas the Irish ones consisted primarily of polyploidF. vesiculosus.
Dynamic sliding of frictionally held bimaterial interfaces subjected to impact shear loading
Authors: Lykotrafitis G , Rosakis A.J
Published: May 2006

The fast frictional sliding along an incoherent interface of a bimaterial system composed of a Homalite and a steel plate is studied experimentally in a microsecond time-scale. The plates are held together by a static uniform compressive pre-stress while dynamic sliding is initiated by asymmetric impact. The full-field technique of dynamic photoelasticity is simultaneously used with a local technique of velocimetry based on laser interferometry. In the case where the impact loading is applied to the Homalite plate, a shear Mach line originates from a disturbance propagating along the interface supersonically with respect to the dilatational wave speed of Homalite and it crosses the P-wave front. The sliding starts well behind the P-wave front in Homalite and it propagates with a supershear speed with respect to Homalite. A fast interface wave and a wrinkle-like opening pulse (detachment wave) travelling along the interface are observed. When the impact loading is applied to the steel plate, the local sliding velocity measurement reveals that sliding initiates with the arrival of the P-wave front in the steel plate.
Crack-front instability in a confined elastic film
Authors: Adda-Bedia M , Mahadevan L
Published: May 2006

We study the undulatory instability of a straight crack front generated by peeling a flexible elastic plate from a thin elastomeric adhesive film. We show that there is a threshold for the onset of the instability that is dependent on the ratio of two length-scales that arise naturally in the problem: the thickness of the film and an elastic length defined by the stiffness of the plate and that of the film. A linear stability analysis predicts that the wavelength of the instability scales linearly with the film thickness. Our results are qualitatively and quantitatively consistent with recent experiments, and show how crack fronts may lose stability due to a competition between bulk and surface effects in the presence of multiple length scales.
Possible human impacts on adaptive radiation: beak size bimodality in Darwin's finches
Authors: Hendry Andrew P , Grant Peter R , Rosemary Grant B , Ford Hugh A , Brewer Mark J , Podos Jeffrey
Published: May 2006

Adaptive radiation is facilitated by a rugged adaptive landscape, where fitness peaks correspond to trait values that enhance the use of distinct resources. Different species are thought to occupy the different peaks, with hybrids falling into low-fitness valleys between them. We hypothesize that human activities can smooth adaptive landscapes, increase hybrid fitness and hamper evolutionary diversification. We investigated this possibility by analysing beak size data for 1755Geospiza fortismeasured between 1964 and 2005 on the island of Santa Cruz, Galápagos. Some populations of this species can display a resource-based bimodality in beak size, which mirrors the greater beak size differences among species. We first show that an historically bimodal population at one site, Academy Bay, has lost this property in concert with a marked increase in local human population density. We next show that a nearby site with lower human impacts, El Garrapatero, currently manifests strong bimodality. This comparison suggests that bimodality can persist when human densities are low (Academy Bay in the past, El Garrapatero in the present), but not when they are high (Academy Bay in the present). Human activities may negatively impact diversification in ‘young’ adaptive radiations, perhaps by altering adaptive landscapes.
Estimating diversity of Indo-Pacific coral reef stomatopods through DNA barcoding of stomatopod larvae
Authors: Barber Paul , Boyce Sarah L
Published: May 2006

There is a push to fully document the biodiversity of the world within 25 years. However, the magnitude of this challenge, particularly in marine environments, is not well known. In this study, we apply DNA barcoding to explore the biodiversity of gonodactylid stomatopods (mantis shrimp) in both the Coral Triangle and the Red Sea. Comparison of sequences from 189 unknown stomatopod larvae to 327 known adults representing 67 taxa in the superfamily Gonodactyloidea revealed 22 distinct larval operational taxonomic units (OTUs). In the Western Pacific, 10 larval OTUs were members of the Gonodactylidae and Protosquillidae where success of positive identification was expected to be 96.5%. However, only five OTUs could be identified to species and at least three OTUs represent new species unknown in their adult form. In the Red Sea where the identification rate was expected to be 75% in the Gonodactylidae, none of four larval OTUs could be identified to species; at least two represent new species unknown in their adult forms. Results indicate that the biodiversity in this well-studied group in the Coral Triangle and Red Sea may be underestimated by a minimum of 50% to more than 150%, suggesting a much greater challenge in lesser-studied groups. Although the DNA barcoding methodology was effective, its overall success was limited due to the newly discovered taxonomic limitations of the reference sequence database, highlighting the importance of synergy between molecular geneticists and taxonomists in understanding and documenting our world's biodiversity, both in marine and terrestrial environments.
Fossil evidence of Archaean life
Authors: Schopf J. William
Published: May 2006

Evidence for the existence of life during the Archaean segment of Earth history (more than 2500 Myr ago) is summarized. Data are presented for 48 Archaean deposits reported to contain biogenic stromatolites, for 14 such units reported to contain 40 morphotypes of putative microfossils, and for 13 especially ancient, 3200–3500 Myr old geologic units for which available organic geochemical data are also summarized. These compilations support the view that life's existence dates from more than or equal to 3500 Myr ago.
Multiple secondary origins of the anaerobic lifestyle in eukaryotes
Authors: Martin Embley T
Published: May 2006

Classical ideas for early eukaryotic evolution often posited a period of anaerobic evolution producing a nucleated phagocytic cell to engulf the mitochondrial endosymbiont, whose presence allowed the host to colonize emerging aerobic environments. This idea was given credence by the existence of contemporary anaerobic eukaryotes that were thought to primitively lack mitochondria, thus providing examples of the type of host cell needed. However, the groups key to this hypothesis have now been shown to contain previously overlooked mitochondrial homologues called hydrogenosomes or mitosomes; organelles that share common ancestry with mitochondria but which do not carry out aerobic respiration. Mapping these data on the unfolding eukaryotic tree reveals that secondary adaptation to anaerobic habitats is a reoccurring theme among eukaryotes. The apparent ubiquity of mitochondrial homologues bears testament to the importance of the mitochondrial endosymbiosis, perhaps as a founding event, in eukaryotic evolution. Comparative study of different mitochondrial homologues is needed to determine their fundamental importance for contemporary eukaryotic cells.
Envelope proteins of spleen necrosis virus form infectious human immunodeficiency virus type 1 pseudotype vector particles, but fail to incorporate upon substitution of the cytoplasmic domain with that of Gibbon ape leukemia virus
Authors: Stitz Jörn , Wolfrum Nina , Buchholz Christian J. , Cichutek Klaus
Published: May 2006

The wild-type (wt) envelope (Env) proteins of spleen necrosis virus (SNV), together with the transmembrane (TM) protein fused to antibody domains (scFv), have been used for the generation of stable packaging cell lines releasing pseudotyped cell targeting vectors derived from SNV andMurine leukemia virus(MLV). As a first step towards assessing whether HIV-1(SNV/TM-scFv) packaging cells could be established for the production of lentiviral cell targeting vectors, it is reported here that infectious HIV-1-derived particles pseudotyped with wt SNV Env proteins could be generated. Using novel chimeric SNV-derived Env proteins encompassing wt and engineered cytoplasmic domains (C-tail) of the Gibbon ape leukemia virus (GaLV) TM protein, it was further shown that the wt C-tail not only excludes the GaLV TM protein from incorporation into HIV-1 particles, but confers this phenotype to other retroviral envelopes upon C-terminal fusion.
Murine leukemia virus transmembrane protein R-peptide is found in small virus core-like complexes in cells
Authors: Andersen Klaus Bahl , Diep Huong Ai , Zedeler Anne
Published: May 2006

The core of the retrovirus Murine leukemia virus (MLV) consists of the Gag precursor protein and viral RNA. It assembles at the cytoplasmic face of the cell membrane where, by an unclear mechanism, it collects viral envelope proteins embedded in the cell membrane and buds off. The C-terminal half of the short cytoplasmic tail of the envelope transmembrane protein (TM) is cleaved off to yield R-peptide and fusion-active TM. In Moloney MLV particles, R-peptide was found to bind to core particles. In cells, R-peptide and low amounts of uncleaved TM were found to be associated with small core-like complexes, i.e. mild detergent-insoluble, Gag-containing complexes with a density of 1.23 g ml−1 and a size of 150–200 S. Our results suggest that TM associates with the assembling core particle through the R-peptide before budding and that this is the mechanism by which the budding virus acquires the envelope proteins.
Activation of early gene transcription in polyomavirus BK by human immunodeficiency virus type 1 Tat
Authors: Gorrill Timothy , Feliciano Mariha , Mukerjee Ruma , Sawaya Bassel E. , Khalili Kamel , White Martyn K.
Published: May 2006

Polyomavirus BK (BKV) is a serious problem for immunocompromised patients, where latent virus can enter into the lytic cycle causing cytolytic destruction of host cells. BKV infects >80 % of the population worldwide during childhood and then remains in a latent state in the kidney. In the context of immunosuppression in kidney transplant patients, reactivation of the viral early promoter (BKVE) results in production of T antigen, enabling virus replication and transition from latency to the lytic phase, causing polyomavirus-associated nephropathy. Reactivation of BKV can also cause complications such as nephritis, atypical retinitis and haemorrhagic cystitis in AIDS patients. Here, the effects of human immunodeficiency virus type 1 (HIV-1) proteins Tat and Vpr on BKV transcription were investigated and it was demonstrated that Tat dramatically stimulated BKVE. Site-directed mutagenesis analysis of potential Tat-responsive transcriptional motifs complemented by an electrophoretic mobility shift assay (EMSA) showed that Tat activated BKVEby inducing binding of the NF-κB p65 subunit to aκB motif near the 3′ end of BKVE. In addition, a sequence within the 5′ UTR of BKVEtranscripts (BKVE-TAR) was identified that is identical to the HIV-1 transactivation response (TAR) element. The BKVE-TAR sequence bound TAT in RNA EMSA assays and deletion of the BKVE-TAR sequence eliminated Tat transactivation of BKVEtranscription. Thus, Tat positively affected BKVEtranscription by a dual mechanism and this may be important in diseases involving BKV reactivation in AIDS patients.
CD9-dependent regulation of Canine distemper virus-induced cell–cell fusion segregates with the extracellular domain of the haemagglutinin
Authors: Singethan K. , Topfstedt E. , Schubert S. , Duprex W. P. , Rima B. K. , Schneider-Schaulies Jürgen
Published: May 2006

Antibodies to CD9, a member of the tetraspan transmembrane-protein family, selectively inhibitCanine distemper virus(CDV)-induced cell–cell fusion. Neither CDV-induced virus–cell fusion nor cell–cell fusion induced by the closely related morbillivirusMeasles virus(MV) is affected by anti-CD9 antibodies. As CDV does not bind CD9, an unknown, indirect mechanism is responsible for the observed inhibition of cell–cell fusion. It was investigated whether this effect was restricted to only one viral glycoprotein, either the haemagglutinin (H) or the fusion (F) protein, which form a fusion complex on the surface of virions and infected cells, or whether it is dependent on both in transient co-transfection assays. The susceptibility to CD9 antibodies segregates with the H protein of CDV. By exchanging portions of the H proteins of CDV and MV, it was determined that the complete extracellular domain, including the predicted stem structure (stem 1, barrel strand 1 and stem 2) and globular head domain, of the CDV-H protein mediates the effect. This suggests that interaction of the CDV-H protein with an unknown cellular receptor(s) is regulated by CD9, rather than F protein-mediated membrane fusion.
Analysis of gene-expression profiles by oligonucleotide microarray in children with influenza
Authors: Kawada Jun-ichi , Kimura Hiroshi , Kamachi Yoshiro , Nishikawa Kazuo , Taniguchi Mariko , Nagaoka Kayuri , Kurahashi Hiroki , Kojima Seiji , Morishima Tsuneo
Published: May 2006

In order to clarify the mechanism of the host response to influenza virus, gene-expression profiles of peripheral blood obtained from paediatric patients with influenza were investigated by oligonucleotide microarray. In the acute phase of influenza, 200 genes were upregulated and 20 genes were downregulated compared with their expression in the convalescent phase. Interferon-regulated genes, such as interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) and vipirin, were strongly upregulated in the acute phase. Gene ontology analysis showed that immune response genes were highly overrepresented among the upregulated genes. Gene-expression profiles of influenza patients with and without febrile convulsion were also studied. In patients with febrile convulsion, 22 genes were upregulated and five were downregulated compared with their expression in patients without febrile convulsion. These results should help to clarify the pathogenesis of influenza and its neurological complications.
NS3 protein of Hepatitis C virus associates with the tumour suppressor p53 and inhibits its function in an NS3 sequence-dependent manner
Authors: Deng Lin , Nagano-Fujii Motoko , Tanaka Motofumi , Nomura-Takigawa Yuki , Ikeda Masanori , Kato Nobuyuki , Sada Kiyonao , Hotta Hak
Published: May 2006

The N-terminal 198 residues of NS3 (NS3-N) of Hepatitis C virus (HCV) subtype 1b obtained from 29 patients, as well as full-length NS3 (NS3-Full), were analysed for their subcellular localization, interaction with the tumour suppressor p53 and serine protease activity in the presence and absence of the viral cofactor NS4A. Based on the subcellular-localization patterns in the absence of NS4A, NS3-N sequences were classified into three groups, with each group exhibiting either dot-like, diffuse or a mixed type of localization. Chimeric NS3-Full sequences, each consisting of an individual NS3-N and a shared C-terminal sequence, showed the same localization patterns as those of the respective NS3-N. Site-directed mutagenesis experiments revealed that a single or a few amino acid substitutions at a particular position(s) of NS3-N altered the localization pattern. Interestingly, NS3 of the dot-like type, either NS3-N or NS3-Full, interacted with p53 more strongly than that of the diffuse type, in both the presence and the absence of NS4A. Moreover, NS3-N of the dot-like type suppressed trans-activating activity of p53 more strongly than that of the diffuse type. Serine protease activity did not differ significantly between the two types of NS3. In HCV RNA replicon-harbouring cells, physical interaction between NS3 and p53 was observed consistently and p53-mediated transcriptional activation was suppressed significantly compared with HCV RNA-negative control cells. Our results collectively suggest the possibility that NS3 plays an important role in the hepatocarcinogenesis of HCV by interacting differentially with p53 in an NS3 sequence-dependent manner.
Evolution of Bovine herpesvirus 4: recombination and transmission between African buffalo and cattle
Authors: Dewals Benjamin , Thirion Muriel , Markine-Goriaynoff Nicolas , Gillet Laurent , de Fays Katalin , Minner Frédéric , Daix Virginie , Sharp Paul M. , Vanderplasschen Alain
Published: May 2006

Bovine herpesvirus 4 (BoHV-4) has been isolated from cattle throughout the world, but virological and serological studies have suggested that the African buffalo is also a natural host for this virus. It has previously been found that the Bo17 gene of BoHV-4 was acquired from an ancestor of the African buffalo, probably around 1.5 million years ago. Analysis of the variation of the Bo17 gene sequence among BoHV-4 strains suggested a relatively ancient transmission of BoHV-4 from the buffalo to the Bos primigenius lineage, followed by a host-dependent split between zebu and taurine BoHV-4 strains. In the present study, the evolutionary history of BoHV-4 was investigated by analysis of five gene sequences from each of nine strains representative of the viral species: three isolated from African buffalo in Kenya and six from cattle from Europe, North America and India. No two gene sequences had the same evolutionary tree, indicating that recombination has occurred between divergent lineages; six recombination events were delineated for these sequences. Nevertheless, exchange has been infrequent enough that a clonal evolutionary history of the strains could be discerned, upon which the recombination events were superimposed. The dates of divergence among BoHV-4 lineages were estimated from synonymous nucleotide-substitution rates. The inferred evolutionary history suggests that African buffalo were the original natural reservoir of BoHV-4 and that there have been at least three independent transmissions from buffalo to cattle, probably via intermediate hosts and – at least in the case of North American strains – within the last 500 years.
Three-dimensional birefringence imaging with a microscope tilting-stage. I. Uniaxial crystals
Authors: Pajdzik L. A. , Glazer A. M.
Published: May 2006

The development of a microscope tilting-stage suitable for use with birefringence imaging is described, thus enabling precise three-dimensional birefringence information of uniaxial crystals to be obtained. Equations have been derived for uniaxial crystals in any orientation. The technique enables precise values of the birefringence Δn=ne−no(difference between extraordinary and ordinary refractive index) and orientation of the optic axis to be obtained. The sign of the optical indicatrix may be unambiguously identified. The method is also able to obtain information on preferred orientation in a polycrystalline material. In addition to this, an unknown crystalline material may be identified, or at least classified within a specific group of crystalline materials.
The determination of pore volumes, pore shapes and diffusion paths in microporous crystals
Authors: Küppers Horst , Liebau Friedrich , Spek Anthony L.
Published: May 2006

The original optionSOLVof the programPLATON, which is primarily devoted to the study of organic structures, has been extended to studies of microporous inorganic crystals. The space that is available for a potential spherical guest within a pore can be regarded as being outlined by rolling a sphere of the guest's radius over the surfaces of the host atoms that form the pore. The volumes of the pores are determined in Å3and the pore shapes can be drawn. The pore volumes of several microporous phases have been calculated and compared with results obtained with other methods. An essential feature of the program is the option to vary a parameter called `probe radius', which models the size of a guest. The decision whether a void is a pore or not and the dimensionality of a pore depend on the radius of the guest, which is approximated by a sphere. This is demonstrated for the structure of the zeolite afghanite. With decreasing probe radius, cages can coalesce into larger cages and finally into channels and channel systems. The variation of the probe radius allows one to determine whether a window between adjacent pores is permeable to guests; in addition, diffusion paths in zeolites and zeolite-like structures can be determined and visualized.
Microstructural analysis of integrated pin-shaped two-dimensional and three-dimensional ferroelectric capacitors from micro-focused synchrotron X-ray techniques
Authors: Menou N. , Muller Ch. , Goux L. , Barrett R. , Lisoni J. G. , Schwitters M. , Wouters D. J.
Published: May 2006

Future development of ferroelectric random access memory requires the integration of three-dimensional ferroelectric capacitors (FeCAP) in a microelectronic architecture. In this paper, pin-shaped two-dimensional and three-dimensional Sr0.8Bi2.2Ta2O9-based FeCAP arrays were characterized using an original approach combining micro-focused synchrotron X-ray fluorescence and diffraction. From a modelling approach, dimensional, chemical and microstructural details were extracted over a series of capacitor arrays. Hence, these techniques proved insightful for a non-destructive benchmarking approach. In addition, for all investigated capacitor geometries, the micro-fluorescence experiments evidenced a well controlled chemical composition within the FeCAP arrays, attesting the stability of the elaboration and integration steps. Nevertheless, micro-diffraction experiments have indicated a lower control of the ferroelectric film crystallographic orientation from one capacitor to the next, despite a well defined chemical composition. This feature was attributed to the presence of patterned bottom electrodes, bringing to light the role of the slanted capacitor sidewalls in the three-dimensional geometry and partially explaining the non-optimized electrical polarization usually measured in three-dimensional capacitors with respect to planar geometry.
Anti‐CXCR3 staining is useful for detecting human cutaneous and mucosal mast cells
Authors: FUKIWAKE Noriko , MOROI Yoichi , IMAFUKU Shinichi , MASUDA Teiichi , KOKUBA Hisashi , FURUE Masutaka , URABE Kazunori
Published: May 2006

Human synovial mast cells (MC) can be immunolabelled with antihuman CXCR3 antibody (Ab) (clone 49801). We have investigated whether cutaneous and mucosal MC are stained with anti‐CXCR3 Ab in paraffin‐embedded sections. Immunohistochemical staining and immunofluorescence double staining assays were performed with anti‐CXCR3, anti‐tryptase, and anti‐chymase Ab using normal skin, psoriatic skin lesions, and normal colon. When compared with tryptase and chymase staining, 100% of the cutaneous and 98% of the mucosal MC were positive for CXCR3. Anti‐CXCR3 staining is a useful marker for human cutaneous and mucosal MC in paraffin‐embedded sections.
A case of discoid lupus erythematosus of the eyelid
Authors: KOGA Monji , KUBOTA Yumiko , KIRYU Hiromaro , NAKAYAMA Juichiro
Published: May 2006

A 39‐year‐old man was first evaluated 12 years ago for erosive erythema of the left lower eyelid. The response to topical therapy was poor. The eyelid lesion was excised on the patient's demand 6 years ago and blepharoplasty was performed. However, recurrence of erythematous plaques at the same site prompted referral to our department. Examination clinically revealed atrophic erythematous plaques and several white papules on the left lower eyelid, in addition to an atrophic erythema of the upper back. The histopathological findings of both plaques and papules were typical of discoid lupus erythematosus. Immunoserological findings suggestive of systemic lupus erythematosus were absent. The lesions improved with administration of low‐dose corticosteroids. Discoid lupus erythematosus involving the eyelid is rare, and definitive diagnosis often takes considerable period of time. In patients with lesions of the eyelid such as erythema or papules that are refractory to treatment, skin biopsy and careful physical examination of the entire body for similar lesions are important.
Trends in alcohol‐related mortality in Sweden 1969–2002: an age‐period‐cohort analysis
Authors: Rosén Måns , Haglund Bengt
Published: May 2006

Aim  To study the effects of age, period and cohorts on alcohol‐related mortality trends in Sweden. 

Design  The study comprises an age‐period‐cohort analysis.

Setting and participants  The analysis was based on all deaths in the Swedish population between 1969 and 2002.

Measurements  Data on alcohol‐related deaths in Sweden from 1969 to 2002 excluding accidental injury and homicide were used. The analysis covered 43 021 deaths. 

Findings  Time period and birth cohort both influenced alcohol‐related mortality. Male cohorts born in the 1930–40s exhibited the highest alcohol‐related mortality, while for females those born in the 1940–50s had the highest alcohol‐related mortality. For both men and women, those born in the 1960–70s had the lowest age‐adjusted alcohol‐related mortality. High‐risk cohorts were young or in early adulthood during the periods that alcohol became more available in Sweden. The low‐risk cohorts of the 1960–70s were brought up during a period when society was concerned with increasing alcohol problems and more emphasis was placed on issuing alcohol awareness information in schools.

Conclusions  Cohort effects were found suggesting that the link between alcohol consumption and non‐accident alcohol‐related mortality at the population level is dependent on other factors that may change over time. One such factor may be that restrictive alcohol policies have a greater effect on drinking in those who are younger at the time they are put into effect.