bluuebunny/crossref_metadata_2025 huggingface dataset:
The unitary event amplitude of mouse retinal on-cone bipolar cells
Authors: BERNTSON AMY , TAYLOR W. ROWLAND
Published: April 2004

Light-evoked synaptic currents were recorded from on-cone bipolar cells in the mouse retina. Fluctuations in the synaptic current observed during maintained light steps were analyzed in order to estimate the amplitude of the underlying unitary event. The maximal synaptic current variance was 5-fold larger than the maximum expected from fluctuations in the number of active postsynaptic channels. Due to uncertainty in the contribution from channel variance, we calculated a range of values for the unitary event amplitude. The observed variance could be accounted for if 30–39 synaptic sites randomly generated unitary events with a waveform identical to the flash-response, and an amplitude of −3.1 to −2.4 pA. The amplitude is consistent with gating about five mGluR6 channels. The shape of the variance–mean relation suggests that in bright light transmitter release approaches zero, while in darkness transmitter release saturates the postsynaptic response. Thus the on-cone bipolar cell synapse is operating over its entire possible range. If it is assumed that the postsynaptic response saturates when one unitary event occurs per integration time, then a lower bound for the unitary event rate is 18 events/s/synaptic site. If the unitary event is generated by a single synaptic vesicle, the results suggest the total vesicle cycling rate available for encoding the on-cone bipolar cell signal is about 540–700 s−1.
Complete flatmounting of the macaque cerebral cortex
Authors: SINCICH LAWRENCE C. , ADAMS DANIEL L. , HORTON JONATHAN C.
Published: April 2004

The elaborate folding of the brain surface has posed a practical
impediment to investigators engaged in mapping the areas of the
cerebral cortex. This obstacle has been overcome partially by the
development of methods to erase the sulci and gyri by physically
flattening the cortex prior to sectioning. In this study, we have
prepared a step-by-step atlas of the flatmounting process for the
entire cerebral cortex in the macaque monkey. The cortex was dissected
from the white matter, unfolded, and flattened in a single piece of
tissue by making three relieving cuts. The flatmount was sectioned at
60–75 μm and processed for cytochrome oxidase (CO) or myelin.
From animal to animal there was nearly a twofold variation in the
surface area of individual cortical regions, and of the whole cortex.
In each specimen, a close correlation was found between V1 surface area
(mean = 1343 mm2), V2 surface area (mean = 1012
mm2), hippocampal area (mean = 181 mm2), and
total cerebral cortex area (mean = 10,430 mm2). The complete
pattern of CO stripes in area V2 was labeled clearly in several cases;
the number of cycles of thick-pale-thin-pale stripes ranged from 26 to
34. Characteristic patterns of strong CO activity were encountered in
areas V3, MT, auditory and somatosensory cortex. In some animals we
made injections of a retrograde tracer, gold-conjugated cholera toxin B
subunit, into area V2 to identify all sources of cortical input. In
addition to previously described inputs, we identified three new
regions in the occipitotemporal region that project to V2. Flatmounting
the cerebral cortex is a simple, efficient method that can be used
routinely for mapping areas and connections in the macaque brain, the
most widely used primate model of the human brain.
Funktionelle Hemisphärenasymmetrie im Vergleich der Geschlechter
Authors: Leichner Reinhard , Grether Marcel
Published: April 2004

Zusammenfassung. Im Versuch wird der Frage nachgegangen, unter welchen Bedingungen die stärkere funktionelle Hemisphärenasymmetrie männlicher gegenüber weiblichen Personen auftritt. Den Personen wurde ein Film vorgespielt, der von keiner, trauriger oder fröhlicher Musik begleitet wurde, die die Personen am rechten, linken oder beiden Ohren hörten. Die Personen beurteilten die durch die gesamte Szene ausgelösten Emotionen sowie die Musik. Ausgehend von dem Sachverhalt, dass die emotionalisierende Wirkung der am linken Ohr (rechte Hemisphäre) eingespielten Musik besser erkannt wird als die am rechten Ohr (linke Hemisphäre) dargebotene, wurde für die männlichen Personen eine größere Differenz in den Urteilen nach rechts- vs. linkshemisphärischem Hören der Musik postuliert als für die weiblichen Personen. Dieser Effekt - so das Postulat weiterhin - tritt aber nur bei Personen auf, die eine geringe Resonanzfähigkeit gegenüber Schönem bekunden. Die Ergebnisse bestätigen die Hypothese für die Emotionsurteile. Die Teilnehmeranzahl betrug N = 112.
Extension of the North Anatolian Fault into the North Aegean Trough: Evidence for transtension, strain partitioning, and analogues for Sea of Marmara basin models
Authors: McNeill L. C. , Mille A. , Minshull T. A. , Bull J. M. , Kenyon N. H. , Ivanov M.
Published: April 2004

The North Aegean Trough is tectonically controlled by the projection of the North Anatolian Fault from western Turkey and the Sea of Marmara into the Aegean, where deformation is distributed in contrast to the simple strike‐slip fault model for central eastern Turkey. This region accommodates extensional and dextral displacement. New side‐scan sonar data coupled with new subbottom profiler and published seismic data reveal evidence for dextral displacement within the eastern trough and Gulf of Saros in the form of oblique en echelon and Riedel (R, R′, and P) fractures and displaced geomorphic features. Strain partitioning in the shallow crust allows the following two styles of faulting to coexist, supported by earthquake focal mechanisms: (1) transtensional basin‐bounding faults controlling the significant vertical topography of the basin and (2) dextral faulting within the central basin. These styles of faulting merge at greater depths into a single fault. A possible sinistral NW striking fault separates two subbasins and may indicate crustal block rotation with deformation focused in block corners. Such evidence and models from the north Aegean are similar to models of transtension and pull‐apart basins within the Sea of Marmara.
Sediment sorting and transport by flash floods
Authors: Malmon Daniel V. , Reneau Steven L. , Dunne Thomas
Published: April 2004

Flash floods partition the sediment load of arid and semiarid watersheds into components that travel at different rates through the fluvial system and are deposited in characteristic settings. This paper examines sediment sorting and transport by flash floods within a small, sand‐dominated alluvial valley in a semiarid environment, upper Los Alamos Canyon, New Mexico. Floods in the study area partition the sediment load into two distinct facies: a coarse‐grained facies that travels near the channel bed and a fine‐grained facies that travels in suspension. The particle size distributions of channel and floodplain deposits resemble the measured textures of the bed load and suspended load, respectively. Calculations predict that typical flows sort the load into the same two fractions observed in the field. Whereas the transport rate of the coarse fraction depends on flow transport capacity, transport of the fine fraction is controlled by its supply. The long‐term discharge of both fractions is estimated by integrating instantaneous transport relationships over the probability distribution of flows. Over several decades the computed fluxes of the two fractions are approximately the same. Most of the load in both fractions is transported during small to moderate events that occur more than once per year. However, the two fractions are distinct because they are supplied by different sources, transported by different mechanisms, and stored in distinct locations in the valley floor. Sediment sorting by flash floods is an important mechanism in constructing floodplains and in determining the residence times of various particle size classes in alluvial valleys.
Plane wave diffraction by a slit in an impedance plane and a complementary impedance strip
Authors: Çınar Gokhan , Büyükaksoy Alinur
Published: April 2004

The diffraction of plane electromagnetic waves by the configuration formed by a slit in an impedance plane and a parallel complementary impedance strip is investigated. The related boundary value problem is formulated into two uncoupled modified Wiener‐Hopf equations, which are first reduced to pairs of Fredholm integral equations of the second kind and then solved by iterations for large values of the electrical width kl of the slit. Several numerical results illustrating the effects of various parameters, such as the spacing between the slit and the strip, their widths, and surface impedances on the diffraction phenomenon, are presented.
Field-orientation dependent heat capacity measurements at low temperatures with a vector magnet system
Authors: Deguchi K. , Ishiguro T. , Maeno Y.
Published: April 2004

We describe a heat capacity measurement system for the study of the field-orientation dependence for temperatures down to 50 mK. A “vector magnet” combined with a mechanical rotator for the dewar enables the rotation of the magnetic field without mechanical heating in the cryostat by friction. High reproducibility of the field direction, as well as an angular resolution of better than 0.01°, is obtained. This system is applicable to other kinds of measurements which require a large sample space or an adiabatic sample environment, and can also be used with multiple refrigerator inserts interchangeably.
High-power 95 GHz pulsed electron spin resonance spectrometer
Authors: Hofbauer W. , Earle K. A. , Dunnam C. R. , Moscicki J. K. , Freed J. H.
Published: April 2004

High-field/high-frequency electron spin resonance (ESR) offers improved sensitivity and resolution compared to ESR at conventional fields and frequencies. However, most high-field/high-frequency ESR spectrometers suffer from limited mm-wave power, thereby requiring long mm-wave pulses. This precludes their use when relaxation times are short, e.g., in fluid samples. Low mm-wave power is also a major factor limiting the achievable spectral coverage and thereby the multiplex advantage of Fourier transform ESR (FTESR) experiments. High-power pulses are needed to perform two-dimensional (2D) FTESR experiments, which can unravel the dynamics of a spin system in great detail, making it an excellent tool for studying spin and molecular dynamics. We report on the design and implementation of a high-power, high-bandwidth, pulsed ESR spectrometer operating at 95 GHz. One of the principal design goals was the ability to investigate dynamic processes in aqueous samples at physiological temperatures with the intent to study biological systems. In initial experiments on aqueous samples at room temperature, we achieved 200 MHz spectral coverage at a sensitivity of 1.1×1010s spins and a dead time of less than 50 ns. 2D-electron-electron double resonance experiments on aqueous samples are discussed to demonstrate the practical application of such a spectrometer.
New design for a time-of-flight mass spectrometer with a liquid beam laser desorption ion source for the analysis of biomolecules
Authors: Charvat A. , Lugovoj E. , Faubel M. , Abel B.
Published: April 2004

We describe a novel liquid beam mass spectrometer, based on a recently discovered nanosecond laser desorption phenomenon, [W. Kleinekofort, J. Avdiev, and B. Brutschy, Int. J. Mass Ion. Processes 152, 135 (1996)] which allows the liquid-to-vacuum transfer, and subsequent mass analysis of pre-existing ions and ionic associates from liquid microjets of aqueous solutions. The goal of our novel technical approach is to establish a system with good mass resolution that implements improvements on critical components that make the system more reliable and easier to operate. For laser desorption pulsed dye-laser difference frequency mixing is used that provides tunable infrared light near the absorption maximum of liquid water around 3 μm. Different types of liquid beam glass nozzles (convergent capillary and aperture plate nozzles) are investigated and characterized. Starting from theoretical considerations of hydrodynamic drag forces on micrometer size droplets in supersonic rarefied gas flows we succeeded in capturing efficiently the liquid beam in a liquid beam recycling trap operating at the vapor pressure of liquid water. For improving the pollution resistance, the liquid jet high vacuum ion source region is spatially separated from the reflectron time-of-flight mass spectrometer (TOF–MS) working behind a gate valve in an ultrahigh vacuum environment. A simple (simulation optimized) ion optics is employed for the ion transfer from the source to the high vacuum region. This new feature is also mostly responsible for the improved mass resolution. With the present tandem-TOF–MS setup a resolution of m/Δm≈1800 for the low and m/Δm≈700 in the high mass region has been obtained for several biomolecules of different mass and complexity (amino acids, insulin, and cytochrome c).
An orderly retreat: Dedifferentiation is a regulated process
Authors: Katoh Mariko , Shaw Chad , Xu Qikai , Van Driessche Nancy , Morio Takahiro , Kuwayama Hidekazu , Obara Shinji , Urushihara Hideko , Tanaka Yoshimasa , Shaulsky Gad
Published: April 2004

Differentiation is a highly regulated process whereby cells become specialized to perform specific functions and lose the ability to perform others. In contrast, the question of whether dedifferentiation is a genetically determined process, or merely an unregulated loss of the differentiated state, has not been resolved. We show here that dedifferentiation in the social amoebaDictyostelium discoideumrelies on a sequence of events that is independent of the original developmental state and involves the coordinated expression of a specific set of genes. A defect in one of these genes, the histidine kinasedhkA, alters the kinetics of dedifferentiation and uncouples the progression of dedifferentiation events. These observations establish dedifferentiation as a genetically determined process and suggest the existence of a developmental checkpoint that ensures a return path to the undifferentiated state.
Probing TBP interactions in transcription initiation and reinitiation with RNA aptamers that act in distinct modes
Authors: Fan Xiaochun , Shi Hua , Adelman Karen , Lis John T.
Published: April 2004

The TATA-binding protein (TBP) is a critical general transcription factor that associates with the core promoter and acts as a nexus for gene regulation through its interactions with other factors. A large number of proteins recognize the relatively small yet highly conserved C-terminal domain of TBP. One subset of these proteins (general transcription factors) interacts with the TBP·TATA complex and RNA polymerase II to create the preinitiation complex. To study TBP functions in preinitiation complex and other complexes, we generated a set of RNA aptamers with high affinity to yeast TBP. These aptamers act on TBP in different ways: all of them bind TBP competitively with DNA bearing the TATA element, and some can actively disrupt the TBP·TATA interaction in preformed, higher-order complexes containing the additional general transcription factors TFIIB and TFIIA. In crude cell extracts, the aptamers inhibit transcription in ways that reveal the dynamic nature of TBP interactions during initiation and reinitiation.
p19ARFDetermines the Balance between Normal Cell Proliferation Rate and Apoptosis during Mammary Gland Development
Authors: Yi Yijun , Shepard Anne , Kittrell Frances , Mulac-Jericevic Biserka , Medina Daniel , Said Thenaa K.
Published: April 2004

This study demonstrated, for the first time, the following events related to p19ARFinvolvement in mammary gland development: 1) Progesterone appears to regulate p19ARFin normal mammary gland during pregnancy. 2) p19ARFexpression levels increased sixfold during pregnancy, and the protein level plateaus during lactation. 3) During involution, p19ARFprotein level remained at high levels at 2 and 8 days of involution and then, declined sharply at day 15. Absence of p19ARFin mammary epithelial cells leads to two major changes, 1) a delay in the early phase of involution concomitant with downregulation of p21Cip1and decrease in apoptosis, and 2) p19ARFnull cells are immortal in vivo measured by serial transplantion, which is partly attributed to complete absence of p21Cip1compared with WT cells. Although, p19ARFis dispensable in mammary alveologenesis, as evidenced by normal differentiation in the mammary gland of pregnant p19ARFnull mice, the upregulation of p19ARFby progesterone in the WT cells and the weakness of p21Cip1in mammary epithelial cells lacking p19ARFstrongly suggest that the functional role(s) of p19ARFin mammary gland development is critical to sustain normal cell proliferation rate during pregnancy and normal apoptosis in involution possibly through the p53-dependent pathway.
The Raymond and Beverly Sackler archive resource at The Royal Society: a work in progress
Authors: Nixon M.
Published: April 2004

In 1996-97, the Royal Society received an extremely generous grant from Dr Raymond Sackler, Hon. KBE and Mrs Beverly Sackler, to fund a five-year project to digitize biographical information about the Fellowship from 1661 to 1950. This article reviews the project's progress to date, and its future development.
The Royal Society, slavery and the island of jamaica: 1660-1700
Authors: Govier M.
Published: April 2004

This paper presents evidence of the interrelationships that existed between the Royal Society in its early years, the slave colonies, and the West African slave trade, first under the auspices of the Royal Adventurers, and later the Royal African Company (RAC). First, it examines the extent of the overlapping of memberships between the bodies. Second, it chronicles the Society's ownership of shares in the RAC. Third, it investigates involvement by Fellows of the Society in the administration of the (then) slave colony of Jamaica. Finally, it presents a few relevant extracts from the Society's foreign correspondence from outposts of the rising empire, and also extracts from discussions at ordinary meetings concerning the cause of the differences in colour between Europeans and Africans. Following the sale of its shares in the RAC in 1699, no further investments in the slave trade by the Society are known to have occurred.
Prehistory of the British Crystallographic Association
Authors: Blow D. , Wallwork S.
Published: April 2004

Development of a unified organization for British crystallographers was hindered, especially during the 1960s and 1970s, because of the separation of crystallographic groups for physicists and chemists. This was due partly to loyalties to different parent societies and partly to associated financial problems. The British Crystallographic Association was eventually formed by the creation of groups that were affiliated jointly to the parent societies and to the new Association. Founder Members and industrial Founder Sponsors made the Association financially viable, and it is now one of the largest crystallographic societies in the world.
Conserved RNA secondary structures in Flaviviridae genomes
Authors: Thurner Caroline , Witwer Christina , Hofacker Ivo L. , Stadler Peter F.
Published: April 2004

Presented here is a comprehensive computational survey of evolutionarily conserved secondary structure motifs in the genomic RNAs of the family Flaviviridae. This virus family consists of the three genera Flavivirus, Pestivirus and Hepacivirus and the group of GB virus C/hepatitis G virus with a currently uncertain taxonomic classification. Based on the control of replication and translation, two subgroups were considered separately: the genus Flavivirus, with its type I cap structure at the 5′ untranslated region (UTR) and a highly structured 3′ UTR, and the remaining three groups, which exhibit translation control by means of an internal ribosomal entry site (IRES) in the 5′ UTR and a much shorter less-structured 3′ UTR. The main findings of this survey are strong hints for the possibility of genome cyclization in hepatitis C virus and GB virus C/hepatitis G virus in addition to the flaviviruses; a surprisingly large number of conserved RNA motifs in the coding regions; and a lower level of detailed structural conservation in the IRES and 3′ UTR motifs than reported in the literature. An electronic atlas organizes the information on the more than 150 conserved, and therefore putatively functional, RNA secondary structure elements.
Cleavage of eukaryotic initiation factor eIF4G and inhibition of host-cell protein synthesis during feline calicivirus infection
Authors: Willcocks Margaret M. , Carter Michael J. , Roberts Lisa O.
Published: April 2004

Caliciviruses are small, non-enveloped, positive-stranded RNA viruses that are pathogenic for both animals and man. Although their capsid structure and genomic organization are distinct from picornaviruses, they have similarities to these viruses in their non-structural proteins. Picornaviruses induce a rapid inhibition of host-cell cap-dependent protein synthesis and this is mainly achieved through cleavage of eIF4G and/or dephosphorylation of 4E-BP1. In this study, the effect of calicivirus infection was examined on host-cell protein synthesis in order to determine whether they also induce host shut-off. We report that infection of cells with feline calicivirus (FCV) leads to the inhibition of cellular protein synthesis. This is accompanied by the cleavage of the eukaryotic translation initiation factors eIF4GI and eIF4GII in a manner reminiscent of that induced by picornaviruses. However, the cleavages occur at different sites. The potential mechanisms of these cleavage events and the implications for the translation of calicivirus mRNA are discussed.
Sequence analysis and genomic organization of a new insect picorna-like virus, Ectropis obliqua picorna-like virus, isolated from Ectropis obliqua
Authors: Wang Xiaochun , Zhang Jiamin , Lu Jie , Yi Fuming , Liu Chuanfeng , Hu Yuanyang
Published: April 2004

The complete nucleotide sequence of a new insect picorna-like virus, Ectropis obliqua picorna-like virus (EoPV), which causes a fatal infection of Ectropis obliqua larvae, has been determined. The genomic RNA of EoPV is 9394 nt in length and contains a single, large open reading frame (nt 391–9351) encoding a polyprotein of 2987 aa. Sequence comparisons with other viral polyproteins revealed that the consensus sequences for picornavirus RNA helicase, protease and RNA-dependent RNA polymerase proteins are found on the genome in order in the 5′→3′ direction. All structural genes were located at the 5′ terminus. In terms of sequence similarity, identity and genome organization, EoPV resembles mammalian picornaviruses and three other insect picorna-like viruses: Infectious flacherie virus of silkworm, Sacbrood virus of honeybee and Perina nuda picorna-like virus (PnPV). Phylogenetic analysis showed that EoPV is most closely related to PnPV and suggests that these four insect picorna-like viruses might constitute a new group of insect-infectious RNA viruses.
Initiation of viral RNA-dependent RNA polymerization
Authors: van Dijk Alberdina A. , Makeyev Eugene V. , Bamford Dennis H.
Published: April 2004

This review summarizes the combined insights from recent structural and functional studies of viral RNA-dependent RNA polymerases (RdRPs) with the primary focus on the mechanisms of initiation of RNA synthesis. Replication of RNA viruses has traditionally been approached using a combination of biochemical and genetic methods. Recently, high-resolution structures of six viral RdRPs have been determined. For three RdRPs, enzyme complexes with metal ions, single-stranded RNA and/or nucleoside triphosphates have also been solved. These advances have expanded our understanding of the molecular mechanisms of viral RNA synthesis and facilitated further RdRP studies by informed site-directed mutagenesis. What transpires is that the basic polymerase right hand shape provides the correct geometrical arrangement of substrate molecules and metal ions at the active site for the nucleotidyl transfer catalysis, while distinct structural elements have evolved in the different systems to ensure efficient initiation of RNA synthesis. These elements feed the template, NTPs and ions into the catalytic cavity, correctly position the template 3′ terminus, transfer the products out of the catalytic site and orchestrate the transition from initiation to elongation.
Assessment of determinants affecting the dual topology of hepadnaviral large envelope proteins
Authors: Lambert Carsten , Mann Sylvia , Prange Reinhild
Published: April 2004

For functional diversity, the large (L) envelope protein of hepatitis B virus (HBV) acquires a dual transmembrane topology via co-translational membrane integration of the S region and partial post-translational translocation of the preS subdomain. Because each process requires the second transmembrane segment (TM2), we explored the action of this determinant by using protease protection analysis of mutant L proteins. We demonstrated that neither the disruption of a leucine zipper-like motif by multiple alanine substitutions nor the flanking charges of TM2 affected the topological reorientation of L. The dispensability of both putative subunit interaction modules argues against a link between preS post-translocation and envelope assembly. Phenotypic mixing experiments revealed that the preS and S protein domains of the related duck HBV L polypeptide failed to substitute functionally for the topogenic elements of HBV in directing the correct L topogenesis, implicating different translocation mechanisms used by the two hepadnavirus genera.
Tula hantavirus L protein is a 250 kDa perinuclear membrane-associated protein
Authors: Kukkonen Sami K. J. , Vaheri Antti , Plyusnin Alexander
Published: April 2004

The complete open reading frame of Tula hantavirus (TULV) L RNA was cloned in three parts. The middle third (nt 2191–4344) could be expressed in E. coli and was used to immunize rabbits. The resultant antiserum was then used to immunoblot concentrated TULV and infected Vero E6 cells. The L protein of a hantavirus was detected, for the first time, in infected cells and was found to be expressed as a single protein with an apparent molecular mass of 250 kDa in both virions and infected cells. Using the antiserum, the expression level of the L protein was followed and image analysis of immunoblots indicated that there were 104 copies per cell at the peak level of expression. The antiserum was also used to detect the L protein in cell fractionation studies. In cells infected with TULV and cells expressing recombinant L, the protein pelleted with the microsomal membrane fraction. The membrane association was confirmed with membrane flotation assays. To visualize L protein localization in cells, a fusion protein of L and enhanced green fluorescent protein, L–EGFP, was expressed in Vero E6 cells with a plasmid-driven T7 expression system. L–EGFP localized in the perinuclear region where it had partial co-localization with the Golgi matrix protein GM130 and the TULV nucleocapsid protein.
Protective efficacy of a multicomponent vector vaccine in cynomolgus monkeys after intrarectal simian immunodeficiency virus challenge
Authors: Negri Donatella R. M. , Baroncelli Silvia , Catone Stefania , Comini Antonella , Michelini Zuleika , Maggiorella Maria T. , Sernicola Leonardo , Crostarosa Federica , Belli Roberto , Mancini Maria G. , Farcomeni Stefania , Fagrouch Zahra , Ciccozzi Massimo , Boros Stefano , Liljestrom Peter , Norley Stephen , Heeney Jonathan , Titti Fausto
Published: April 2004

We investigated the protective efficacy of a systemic triple vector (DNA/rSFV/rMVA)-based vaccine against mucosal challenge with pathogenic simian immunodeficiency virus (SIV) in cynomolgus monkeys. Animals were immunized at week 0 with DNA (intradermally), at weeks 8 and 16 with recombinant Semliki Forest virus (rSFV, subcutaneously) and finally, at week 24, with recombinant modified vaccinia virus Ankara strain (rMVA, intramuscularly). Both DNA and recombinant viral vectors expressed a wide range of SIV proteins (Gag, Pol, Tat, Rev, Env and Nef). This immunization strategy elicited cell-mediated rather than humoral responses that were especially increased following the last boost. Upon intrarectal challenge with pathogenic SIVmac251, three of the four vaccinated monkeys dramatically abrogated virus load to undetectable levels up to 41 weeks after challenge. A major contribution to this vaccine effect appeared to be the T-cell-mediated immune response to vaccine antigens (Gag, Rev, Tat, Nef) seen in the early phase of infection in three of the four vaccinated monkeys. Indeed, the frequency of T-cells producing antigen-induced IFN-γmirrored virus clearance in the vaccinated and protected monkeys. These results, reminiscent of the efficacy of live attenuated virus vaccines, suggest that vaccination with a combination of many viral antigens can induce a robust and stable vaccine-induced immunity able to abrogate virus replication.
Isolates of cytomegalovirus (CMV) from the black rat Rattus rattus form a distinct group of rat CMV
Authors: Smith L. M. , Tonkin J. N. , Lawson M. A. , Shellam G. R.
Published: April 2004

Two different betaherpesviruses, the English and Maastricht species of rat cytomegalovirus (CMV), have previously been isolated from Rattus norvegicus. CMVs were isolated from both the brown rat, R. norvegicus, and the black rat, R. rattus, within Australia. The viruses isolated from R. norvegicus appeared to be genetically related to the English species of rat CMV by PCR, RFLP, and sequencing, but the viruses isolated from R. rattus were distinct from both prototype virus species, although more closely genetically related to the Maastricht virus. This is the first genetic characterization of cytomegaloviruses from R. rattus, and the first isolation of CMVs from Australian rats.
Adenovirus fibre exchange alters cell tropism in vitro but not transgene-specific T CD8+ immune responses in vivo
Authors: Mercier S. , Verhaagh S. , Goudsmit J. , Lemckert A. , Monteil M. , Havenga M. , Eloit M.
Published: April 2004

Gene transfer with recombinant adenoviruses (rAds) is a powerful means of inducing an immune response against a transgene product. However, little is known about the mechanisms that underlie the induction of the immune response after intramuscular inoculation of adenovirus and, in particular, the relative role of the different cell types transduced. Several studies have suggested that CD8+cytotoxic T lymphocyte responses elicited after inoculation of adenoviruses (Ads) are induced both by direct transduction of antigen presenting cells (APCs) and by cross-priming. In the present study, a library of fibre-chimeric rAds was screened in order to identify rAds with distinct capacities to express transgene product in murine cell types naturally found in muscle, i.e. myoblasts, endothelial cells (both representing non-APCs) and dendritic cells (representing APCs). Four selected pseudotypes, differing in their ability to infect muscular cells were used to immunize C57BL/6 mice. The relationship between the capacity to transduce non-APC or APCin vitroand the ability to induce humoral and cellular responses against theβ-galactosidase antigen after intramuscular inoculation were studied. Results indicate that CD8+T cell responses against theβ-galactosidase antigen were similar after inoculation of the four viruses, thus revealing no direct relationship with their ability to transduce myoblasts, endothelial cells or dendritic cellsin vitro.
Identification of a nuclear localization signal and nuclear export signal of the umbraviral long-distance RNA movement protein
Authors: Ryabov Eugene V. , Kim Sang Hyon , Taliansky Michael
Published: April 2004

The 27 kDa protein encoded by ORF3 of Groundnut rosette virus (GRV) is required for viral RNA protection and movement of viral RNA through the phloem. Localization studies have revealed that this protein is located in nuclei, preferentially targeting nucleoli. We have demonstrated that amino acids (aa) 108–122 of the GRV ORF3 protein contain an arginine-rich nuclear localization signal. Arginine-to-asparagine substitutions in this region decreased the level of the ORF3 protein accumulation in nuclei. A leucine-rich nuclear export signal (NES) was located at aa 148–156 of the GRV ORF3 protein. Leucine-to-alanine substitutions in this region resulted in a dramatic increase in GRV ORF3 protein accumulation in both nuclei and nucleoli. Consistent with this, we also showed that the previously identified NES of BR1 protein of Squash leaf curl virus can functionally replace the leucine-rich region of GRV ORF3 in nuclear export.
Interleukin-18 and glycosaminoglycan binding by a protein encoded by Variola virus
Authors: Esteban David J. , Nuara Anthony A. , Buller R. Mark L.
Published: April 2004

Poxvirus interleukin (IL)-18 binding proteins (IL-18BPs) are soluble decoys that inhibit the activity of IL-18. The aim of this study was to demonstrate IL-18 binding activity of theVariola virusprotein D7L. D7L effectively inhibited the biological activity of IL-18 in a bioassay. We compared the affinity and kinetics of D7L and theEctromelia virusIL-18BP, p13, for human and murine IL-18 using surface plasmon resonance and no differences were detected, indicating that the differences in amino acid sequence did not affect binding or species specificity. Both proteins had higher affinity for murine than human IL-18. This was similar to human IL-18BP and theMolluscum contagiosum virusIL-18BP, which also demonstrated higher affinity for human IL-18. The host range ofVariola virusis limited to humans and thus the affinity of D7L for IL-18 does not correlate with its host range. Furthermore, we demonstrated that D7L is capable of interacting with glycosaminoglycans (GAGs) via the C terminus, while p13 is not. Importantly, D7L interacted with both GAG and IL-18 simultaneously, indicating that the binding sites were distinct.
Inter‐library loan services and access to electronic resources in French university libraries: a marriage of reason
Authors: Boukacem Chérifa
Published: April 2004

This article uses the results of a thesis to analyse the changing structure of access services to scientific and technical information in French university libraries, and corresponding changes in the role of inter‐library loan services. These changes have mainly occurred with the growing integration of electronic resources in collections and an overhaul of the services on offer. Given the specific features of access systems to scientific information and the wide range of users in the various sections of university libraries, we will be attempting a detailed analysis of the situation in the French university network.
Sequences of failure in complex socio‐technical systems
Authors: Weir David
Published: April 2004

This paper reviews the framework proposed by Stafford Beer in his seminal work, Decision and Control, first published in 1966, and argues that these ideas are centrally relevant to a topic on which research interest has developed subsequently, the study of crises, catastrophes and disasters in complex socio‐technical systems in high technology sectors. The problems are not discussed simply in terms of system parameters like variety, redundancy and complexity. Much empirical research supports the view that these systems typically operate in degraded mode. Such variables as hierarchical position, actors' motivations and intentions are relevant to explain the ways in which communication systems typically operate to filter out messages from lower participants and to ignore the “soft signals” from small‐scale and intermittent malfunctions.
A Latino American Requiem for Stafford Beer
Authors: Zarama Roberto , Bermeo José , Lammoglia Nelson , Villamil Jairo
Published: April 2004

This tribute to Stafford Beer is written from the particular situation of a Latin American country. Within this context, we believe that it could be convenient to dissolve the systems movement to assume an ethical‐political position that transforms the relations of dependence in the world‐system from the point of view of economic development. A contribution to this task is the formation of amplifiers of regulatory capacity that has been developed in Colombia. In this paper, we present some preliminary advances of autoethospoiesis and some of its future perspectives of research and action. One of our main objectives is to apply this functor with recurrent, recursive, and incursive operators to the world‐system model.
Major hazard control: the Malaysian experience
Authors: Shaluf Ibrahim M. , Ahmadun Fakharu'l‐razi
Published: April 2004

Malaysia plans to be a fully developed and industrialized country by year 2020. Malaysia has achieved good progress in the industrial sector. The industrial sector is operating plants and factories using and storing hazardous substances in quantities exceeding the threshold quantities. The plants that are dealing with hazardous substances exceeding the threshold quantity are classified as major hazard installations (MHIs). Some MHIs are located in heavily populated areas. Experience shows that MHIs pose a risk to the workers and the neighbors of the plants. Malaysia has taken the preventive measures to protect the workers and the public. The preventive measures have been taken through establishment of authorities to set major hazard control regulations, enforcing the regulations, assessing the safety reports and emergency plans, conducting audits and accident investigations. This paper reviews, in brief, the international regulations and guidelines of major hazard control. The paper also reviews the Malaysian experience of major hazard control.
Transportation in emergencies: an often neglected story
Authors: Scanlon Joseph
Published: April 2004

Looks at the way in which public transport is used for evacuation of personnel in the event of emergencies or disasters. Although the work of the emergency services is well documented, it seems that the important task of evacuation, and particularly the planning, operation and documentation is often overlooked. This article looks at how public transport copes with this task, and suggests that this is due to the sometimes unpredictable nature of the transport system due to roadworks, road closures, accidents, etc. Special events, such as football matches, are a regular occurrence, which include the need to move large crowds to and from the venue. This strategy and planning can be used in the evacuation of people in the event of a disaster.
Monetary policy in a cash‐in‐advance economy: employment, capital accumulation, and the term structure of interest rates
Authors: Mansoorian Arman , Mohsin Mohammed
Published: April 2004

Abstract.  In this paper we study the effects of monetary policies on employment, capital accumulation, consumption, and the term structure of interest rates in a cash‐in‐advance economy, where money is required for consumption expenditures. Monetary policy involves targeting the inflation rate. The detailed dynamics of the model are fully worked out. As no numerical analysis is involved, we are able to identify very clearly the different channels through which monetary policy will impinge on the important macroeconomic variables. The model is also used to discuss the ‘Great Canadian Slump.’ JEL Classification: E52 and E43
Asymmetry in Okun's law
Authors: Silvapulle Paramsothy , Moosa Imad A. , Silvapulle Mervyn J.
Published: April 2004

Abstract.  In this paper we support the proposition that the output‐unemployment relationship as represented by Okun's law is asymmetric. Okun's coefficients are defined based on a dynamic model that allows for asymmetry in the relationship between cyclical output and unemployment. Using data from the United States for the post‐war period, our results show that the short‐run effects of positive cyclical output on cyclical unemployment are quantitatively different from those of negative ones, and the data are consistent with the proposition that cyclical unemployment is more sensitive to negative than to positive cyclical output. Several theoretical explanations of asymmetry rationalize the findings. JEL Classification: C13, C22, E32
Labour markets, liquidity, and monetary policy regimes
Authors: Andolfatto Dave , Hendry Scott , Moran Kevin
Published: April 2004

Abstract.  We develop an equilibrium model of the monetary policy transmission mechanism that highlights information frictions in the market for money and search frictions in the labour market. The information friction increases the persistence in the response of interest rates following monetary policy regime shifts. This occurs because agents have incomplete information about the nature of the shifts and optimally update their inflation forecasts using an ‘adaptive’ expectations rule. The search friction transmits the interest rate movements to the labour market by affecting job creation activities; together, the two frictions imply that unemployment reacts very gradually to monetary policy shocks. JEL Classification: E4, E5
Customer Learning Processes, Strategy Selection, and Performance in Business‐to‐Business Service Firms*
Authors: Zahay Debra , Griffin Abbie
Published: April 2004

Learning about customers takes place through relevant dialogues with those customers, also known as customer relationship management (CRM). As relationships develop, information about the customer is gathered in the firm's customer information systems (CIS): the content, processes, and assets associated with gathering and moving customer information throughout the firm. This research develops a measure of CIS management capabilities based on learning organization theory and measured by the ability to get, store, move, and use information throughout the business unit. This measure is then used to analyze customer learning processes and associated performance in the context of marketing strategic decision making.

This study of 209 business services firms finds that generic marketing strategy positioning (low‐cost and differentiation) and the marketing tactics of personalization and customization are related to CIS development. Customer information systems development in turn is associated with higher levels of customer‐based performance, which in turn is associated with increased business growth.

Since the strongest association with customer‐based performance is strategy selection, the long‐term benefits of the knowledge gained from the CIS may be in the ability to assist in measuring customer‐based performance, rather than in the ability to immediately contribute to performance. Finally, for these firms, customization and personalization are not directly associated with performance and thus may not be necessary to support every firm's marketing strategy.
Measuring Modularity‐Based Manufacturing Practices and Their Impact on Mass Customization Capability: A Customer‐Driven Perspective
Authors: Tu Qiang , Vonderembse Mark A. , Ragu‐Nathan T. S. , Ragu‐Nathan Bhanu
Published: April 2004

As uncertainty in markets and technology intensifies, more companies are adopting modular product and process architectures to cope with increasing demands for individually customized products. Modularity‐based manufacturing is the application of unit standardization or substitution principles to create modular components and processes that can be configured into a wide range of end products to meet specific customer needs. This study defines modularity‐based manufacturing practices (MBMP), develops a valid and reliable instrument to measure MBMP, builds a framework that relates customer closeness, MBMP, and mass customization capability, and tests structural relationships within this framework using LISREL. Based on 303 responses from members of the Society of Manufacturing Engineers, statistically significant and positive relationships were found among customer closeness, modularity‐based manufacturing practices, and mass customization capability. Managerial implications of the empirical findings of this study and future research directions are also discussed.
The generalized linear model for spatial data: assessing the effects of environmental covariates on population density in the field
Authors: Dalthorp D.
Published: April 2004

With interest in spatial ecology growing, correlational field studies are likely to become increasingly important. Unfortunately, ecological field data often do not follow the assumptions of classical statistics, so techniques like the popular and powerful multiple linear regression and its variants are often unreliable, and results can be misleading. The generalized linear model (GLM) is a flexible extension of linear regression that has proved especially useful for discrete data. In this paper, the technique is adapted to accommodate spatially correlated, discrete data. Specifically, to demonstrate the approach, Japanese beetle grub [Popillia japonica Newman (Coleoptera, Scarabaeidae)] population density in the field is modeled as a function of soil organic matter content. The response variable (grub counts in small soil samples) was a spatially autocorrelated, discrete random variable. Three classes of GLMs of the association between soil organic matter content and grub density were compared: (i) regression (assuming normally distributed response variable), (ii) GLM assuming negative binomial counts, and (iii) GLM based on the assumption that the counts conformed to Taylor's power law (TPL). Because the grubs were distributed in patches rather than at random, models that explicitly accounted for the spatial autocorrelation of grub counts were constructed, and compared with models that assumed independent observations. The fitted values for the discrete GLMs [viz., (ii) and (iii)] differed noticeably from the fitted values from multiple regression; but fitted values among the negative binomial and TPL GLMs were virtually identical, regardless of whether the spatial covariance was incorporated into a model, whether a spherical or exponential variogram model was used, or whether variance function parameters were estimated over a large or small scale. However, P‐values for the overall significance of the models depended heavily on whether the GLM assumed a discrete or continuous response variable, and whether or not spatial autocorrelation in the response variable was accounted for. On average, P‐values were 45‐fold higher in the spatial GLMs than in the non‐spatial and 23‐fold higher in the discrete GLMs than in the continuous.