bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Helper Virus-Independent Cytopathogenic Classical Swine Fever Virus Generated by an In Vivo RNA Recombination System
Authors: Gallei Andreas , Rümenapf Till , Thiel Heinz-Jürgen , Becher Paul 
Published: January 2005

ABSTRACT

Molecular analyses revealed that most cytopathogenic (cp) pestivirus strains evolve from noncytopathogenic (noncp) viruses by nonhomologous RNA recombination. In contrast to bovine viral diarrhea virus (BVDV), cp classical swine fever virus (CSFV) field isolates were rarely detected and always represented helper virus-dependent subgenomes. To investigate RNA recombination in more detail, we recently established an in vivo system allowing the efficient generation of recombinant cp BVDV strains in cell culture after transfecting a synthetic subgenomic and nonreplicatable transcript into cells being infected with noncp BVDV (A. Gallei, A. Pankraz, H.-J. Thiel, and P. Becher, J. Virol.
78:
6271-6281, 2004). Using an analogous approach, the first helper virus-independent cp CSFV strain (CP G1) has now been generated by RNA recombination. Accordingly, this study demonstrates the applicability of RNA recombination for designing new viral RNA genomes. The genomic RNA of CP G1 has a calculated size of 18.139 kb, almost 6 kb larger than all previously described CSFV genomes. It contains cellular sequences encoding a polyubiquitin fragment directly upstream of the nonstructural protein NS3 coding gene together with a duplication of viral sequences. CP G1 induces a cytopathic effect on different tissue culture cell lines from pigs and cattle. Subsequent analyses addressed growth kinetics, expression of NS3, and genetic stability of CP G1.
Identification of Internal Sequences in the 3′ Leader Region of Human Respiratory Syncytial Virus That Enhance Transcription and Confer Replication Processivity
Authors: McGivern David R. , Collins Peter L. , Fearns Rachel 
Published: January 2005

ABSTRACT

Previous studies of respiratory syncytial virus have shown that the 44-nucleotide (nt) leader (Le) region is sufficient to initiate RNA replication, producing antigenome RNA, and that the Le and adjoining gene start (GS) signal of the first gene are sufficient to initiate transcription, producing mRNA. A
cis
-acting element necessary for both transcription and replication was mapped within the first 11 nt at the 3′ end of Le. In the present study the remainder of the Le region was mapped to identify sequences important for transcription and replication. A series of minigenomes with mutant Le sequences was generated, and their ability to direct transcription and replication was determined by Northern blot analysis, which examined full-length antigenome and mRNA, and by primer extension analysis, which examined antigenome and mRNA initiation. With regard to transcription, nt 36 to 43, located immediately upstream of the GS signal, were found to be necessary for optimal levels of mRNA synthesis, although the GS signal in conjunction with the 3′-terminal region of Le was sufficient to direct accurate mRNA synthesis initiation. With regard to replication, the first 15 nt of Le were found to be sufficient to direct initiation of antigenome synthesis, but nt 16 to 34 were required in addition for efficient encapsidation and production of full-length antigenome. Analysis of transcripts produced from di- and tricistronic minigenomes indicated that a significant proportion of abortive replicases continue RNA synthesis to the end of the first gene and then continue in a transcription mode along the remainder of the genome.
Phosphorylation and Proteolytic Cleavage of Gag Proteins in Budded Simian Immunodeficiency Virus
Authors: Rue Sarah M. , Roos Jason W. , Tarwater Patrick M. , Clements Janice E. , Barber Sheila A. 
Published: January 2005

ABSTRACT

The lentiviral Gag polyprotein (Pr55
Gag
) is cleaved by the viral protease during the late stages of the virus life cycle. Proteolytic cleavage of Pr55
Gag
is necessary for virion maturation, a structural rearrangement required for infectivity that occurs in budded virions. In this study, we investigate the relationship between phosphorylation of capsid (CA) domains in Pr55
Gag
and its cleavage intermediates and their cleavage by the viral protease in simian immunodeficiency virus (SIV). First, we demonstrate that phosphorylated forms of Pr55
Gag
, several CA-containing cleavage intermediates of Pr55
Gag
, and the free CA protein are detectable in SIV virions but not in virus-producing cells, indicating that phosphorylation of these CA-containing Gag proteins may require an environment that is unique to the virion. Second, we show that the CA domain of Pr55
Gag
can be phosphorylated in budded virus and that this phosphorylation does not require the presence of an active viral protease. Further, we provide evidence that CA domains (i.e., incompletely cleaved CA) are phosphorylated to a greater extent than free (completely cleaved) CA and that CA-containing Gag proteins can be cleaved by the viral protease in SIV virions. Finally, we demonstrate that Pr55
Gag
and several of its intermediates, but not free CA, are actively phosphorylated in budded virus. Taken together, these data indicate that, in SIV virions, phosphorylation of CA domains in Pr55
Gag
and several of its cleavage intermediates likely precedes the cleavage of these domains by the viral protease.
Genomic and Bioinformatics Analysis of HAdV-4, a Human Adenovirus Causing Acute Respiratory Disease: Implications for Gene Therapy and Vaccine Vector Development
Authors: Purkayastha Anjan , Ditty Susan E. , Su Jing , McGraw John , Hadfield Ted L. , Tibbetts Clark , Seto Donald 
Published: January 2005

ABSTRACT

Human adenovirus serotype 4 (HAdV-4) is a reemerging viral pathogenic agent implicated in epidemic outbreaks of acute respiratory disease (ARD). This report presents a genomic and bioinformatics analysis of the prototype 35,990-nucleotide genome (GenBank accession no.
AY594253
). Intriguingly, the genome analysis suggests a closer phylogenetic relationship with the chimpanzee adenoviruses (simian adenoviruses) rather than with other human adenoviruses, suggesting a recent origin of HAdV-4, and therefore species E, through a zoonotic event from chimpanzees to humans. Bioinformatics analysis also suggests a pre-zoonotic recombination event, as well, between species B-like and species C-like simian adenoviruses. These observations may have implications for the current interest in using chimpanzee adenoviruses in the development of vectors for human gene therapy and for DNA-based vaccines. Also, the reemergence, surveillance, and treatment of HAdV-4 as an ARD pathogen is an opportunity to demonstrate the use of genome determination as a tool for viral infectious disease characterization and epidemic outbreak surveillance: for example, rapid and accurate low-pass sequencing and analysis of the genome. In particular, this approach allows the rapid identification and development of unique probes for the differentiation of family, species, serotype, and strain (e.g., pathogen genome signatures) for monitoring epidemic outbreaks of ARD.
Inhibition of Virus DNA Replication by Artificial Zinc Finger Proteins
Authors: Sera Takashi 
Published: January 2005

ABSTRACTPrevention of virus infections is a major objective in agriculture and human health. One attractive approach to the prevention is inhibition of virus replication. To demonstrate this concept in vivo, an artificial zinc finger protein (AZP) targeting the replication origin of theBeet severe curly top virus(BSCTV), a model DNA virus, was created. In vitro DNA binding assays indicated that the AZP efficiently blocked binding of the viral replication protein (Rep), which initiates virus replication, to the replication origin. All of the transgenicArabidopsisplants expressing the AZP showed phenotypes strongly resistant to virus infection, and 84% of the transgenic plants showed no symptom. Southern blot analysis demonstrated that BSCTV replication was completely suppressed in the transgenic plants. Since the mechanism of viral DNA replication is well conserved among plants and mammals, this approach could be applied not only to agricultural crop protection but also to the prevention of virus infections in humans.
Increased Efficiency of Phorbol Ester-Induced Lytic Reactivation of Kaposi's Sarcoma-Associated Herpesvirus during S Phase
Authors: McAllister Shane C. , Hansen Scott G. , Messaoudi Ilhem , Nikolich-Zugich Janko , Moses Ashlee V. 
Published: January 2005

ABSTRACT
Expression of Kaposi's sarcoma-associated herpesvirus (KSHV) lytic genes is thought to be essential for the establishment and progression of KSHV-induced diseases. The inefficiency of lytic reactivation in various in vitro systems hampers the study of lytic genes in the context of whole virus. We report here increased expression of KSHV lytic genes and increased release of progeny virus when synchronized cultures of body cavity-based lymphoma-1 cells are treated with a phorbol ester during S phase of the cell cycle.
Detection and Partial Characterization of Simian Immunodeficiency Virus SIVsm Strains from Bush Meat Samples from Rural Sierra Leone
Authors: Apetrei Cristian , Metzger Michael J. , Richardson David , Ling Binhua , Telfer Paul T. , Reed Patricia , Robertson David L. , Marx Preston A. 
Published: January 2005

ABSTRACT

Human
immunodeficiency virus type 2 (HIV-2) originated from simian
immunodeficiency viruses (SIVs) that naturally infect sooty mangabeys
(SMs;
Cercocebus atys
). In order to further investigate the
relationship between HIV-2 and SIVsm, the SIV specific to the SM, we
characterized seven new SIVsm strains from SMs sold in Sierra Leone
markets as bush meat. The
gag
,
pol
, and
env
sequences showed that, while the viruses of all seven SMs belonged to
the SIVsm-HIV-2 lineage, they were highly divergent viruses, in
spite of the fact that most of the samples originated from the same
geographical region. They clustered in three lineages, two of which
have been previously reported. Two of the new SIVsm strains clustered
differently in
gag
and
env
phylogenetic trees,
suggesting SIVsm recombination that had occurred in the past. In spite
of the fact that our study doubles the number of known SIVsm strains
from wild SMs, none of the simian strains were close to the groups in
which HIV-2 was epidemic (groups A and
B).
Latent Membrane Protein 1 Deletion Mutants Accumulate in Reed-Sternberg Cells of Human Immunodeficiency Virus-Related Hodgkin's Lymphoma
Authors: Guidoboni Massimo , Ponzoni Maurilio , Caggiari Laura , Lettini Antonia A. , Vago Luca , De Re Valli , Gloghini Annunziata , Zancai Paola , Carbone Antonino , Boiocchi Mauro , Dolcetti Riccardo 
Published: January 2005

ABSTRACT
The origin and biological significance of deletions at the 3′ end of the Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP-1) gene are still controversial. We herein demonstrate that LMP-1 deletion mutants are highly associated with human immunodeficiency virus-related Hodgkin's lymphoma (HIV-HL) of Italian patients (29 of 31 cases; 93.5%), a phenomenon that is not due to a peculiar distribution of EBV strains in this area. In fact, although HIV-HL patients are infected by multiple EBV variants, we demonstrate that LMP-1 deletion mutants preferentially accumulate within neoplastic tissues. Subcloning and sequencing of the 3′ LMP-1 ends of two HIV-HL genes in which both variants were present showed the presence of molecular signatures suggestive of a likely derivation of the LMP-1 deletion mutant from a nondeletion ancestor. This phenomenon likely occurs within tumor cells in vivo, as shown by the detection of both LMP-1 variants in single microdissected Reed-Sternberg cells, and may at least in part explain the high prevalence of LMP-1 deletions associated with HIV-HL.
THE INTERIORS OF GIANT PLANETS: Models and Outstanding Questions
Authors: Guillot Tristan 
Published: January 2005

▪ Abstract  We know that giant planets played a crucial role in the making of our Solar System. The discovery of giant planets orbiting other stars is a formidable opportunity to learn more about these objects, what their composition is, how various processes influence their structure and evolution, and most importantly how they form. Jupiter, Saturn, Uranus, and Neptune can be studied in detail, mostly from close spacecraft flybys. We can infer that they are all enriched in heavy elements compared to the Sun, with the relative global enrichments increasing with distance to the Sun. We can also infer that they possess dense cores of varied masses. The intercomparison of presently characterized extrasolar giant planets shows that they are also mainly made of hydrogen and helium, but that they either have significantly different amounts of heavy elements, have had different orbital evolutions, or both. Hence, many questions remain and need to be answered to make significant progress on the origins of planets. Pourquoi l'azur muet et l'espace insondable? Pourquoi les astres d'or fourmillant comme un sable? Arthur Rimbaud—Soleil et chair
Scottish tourism: Scenarios and vision
Authors: Yeoman Ian , Lederer Peter 
Published: January 2005

In order to understand the potential for tourism in Scotland, it is important to look beyond the near future. Four scenarios have been created that paint contrasting pictures of Scottish tourism in 2015. The ‘Dynamic’ scenario creates a £10bn tourism economy with tourism being the number-one industry in Scotland. The ‘Weekend Get away’ sees tourism based upon consumerism and play. The value of tourism in this scenario is £7.6bn. ‘Yesterday’s Destination’ means tourism is based upon the past, and the industry is found to be too complacent. An uncompetitve industry means that growth is only 1 per cent per annum and valued at £5.1bn. Finally, ‘Exclusive Scotland’ means that the Scottish economy has failed as deflation has taken the soul out of the country but favourable exchange rates mean that international high-spending tourists flock to exclusive resorts. Tourism in this scenario is a £2.6bn industry. These four scenarios follow different paths and are driven by different circumstances. But within all of the scenarios, tourism exists. The opportunity for Scotland is to maximise its potential in order that tourism is Scotland’s first and everlasting industry. The paper begins with a commentary by Peter Lederer.
Turning scenarios into a strategy map: Our ambition for Scottish tourism
Authors: Hay Brian , Yeoman Ian 
Published: January 2005

VisitScotland has set out a vision for the Scottish tourism industry in which tourism will be the ‘first and everlasting industry’ of Scotland. This vision is driven by an ambition to increase tourism revenue by 50 per cent within the next ten years. In order to achieve that objective, a strategy map is used to provide direction that sets out the size and shape of the industry. A constructivist interpretation paradigm and a cognitive mapping methodology are used to bring structure to the phenomenon of tourism futures by using a software package called Decision Explorer. This paper describes tourism being shaped by changes in demographics and in monetary policy. The consumer will be price-sensitive and/or sophisticated. Scotland will be recognised as a leisure destination rather than a tourism destination, with revenue growth much more likely to be derived from retail and leisure activities rather than the traditional sectors of accommodation and transport. But as tourism develops in Scotland, faster growth will be seen from European and short-haul markets compared to traditional long-haul markets. Shifts in demand as a result of demographic changes will result in visitors staying more with friends rather than with relatives, particularly in urban locations. A decreasing labour supply will result in more dependency on labour substitutes and the newer technologies.
On the destruction of kaolinite and gibbsite by phenylphosphonic, phenylphosphinic and phenylarsonic acids: evidence for the formation of new Al compounds
Authors: Gardolinski J. E. F. C. , Lagaly G. , Czank M. 
Published: January 2005

AbstractKaolinite and synthetic γ-Al(OH)3 (gibbsite or hydrargillite) were reacted with phenylphosphonic, phenylphosphinic and 2-nitrophenol-4-arsonic acids. The products were studied by powder X-ray diffraction, transmission electron microscopy/selected area electron diffraction/ energy dispersive X-ray/Fourier transform infrared and simultaneous thermogravimetric/differential thermal analysis. The acids were not intercalated but, instead, easily destroyed the structure of the minerals. Lamellar Al phenylphosphonate and aluminium phenylphosphinate and phenylarsonate with polymeric linear-chain structures were formed from kaolinite. The reaction between gibbsite and the same acids yielded almost identical products. No evidence of formation of grafted kaolinite derivatives after the reaction with phenylphosphonic acid was found.
Long-term in vitro transformation of 2-line ferrihydrite to goethite/hematite at 4, 10, 15 and 25°C
Authors: Schwertmann U. , Stanjek H. , Becher H.-H. 
Published: January 2005

Abstract2-line ferrihydrite stored in water at ambient temperatures from 4 to 25°C and at ten different pH values between 2.5 and 12 for up to 10–12 y transformed to both goethite and hematite at all temperatures and pH values except at pH 12 where only goethite was formed. The rate and degree of transformation (20–100%) increased with increasing pH and temperature. The hematite/ (hematite+goethite) ratio varied between 0 and ~0.8, increased with increasing temperature and showed a strong maximum at pH 7–8 which increased from 0.1–0.2 at 4°C to 0.7–0.8 at 25°C. The maximum coincides with the zero point of charge of ferrihydrite where its solubility and, thus, its via-solution transformation rate to goethite are minimal. We assume, therefore, that in this pH-range the (slower) via-solution transformation to hematite can more efficiently compete with that to goethite.
Microstructures and interlayering in pyrophyllite from the Coastal Range of central Chile: evidence of a disequilibrium assemblage
Authors: Ruiz Cruz M. D. , Morata D. , Puga E. , Aguirre L. , Vergara M. 
Published: January 2005

AbstractPyrophyllite from a Triassic sedimentary formation from the Coastal Range of Chile has been investigated by transmission/analytical electron microscopy (TEM/AEM). The mineral assemblage includes pyrophyllite, muscovite, paragonite, a kaolin mineral, boehmite, rutile and hematite. The textures indicate that the protolith was a volcanoclastic rock. Petrographic evidence, chemistry, and the mineral assemblage suggest the intense leaching of the parent rock by a weathering process, before the metamorphic episode, to create the protolith for the pyrophyllite. Pyrophyllite always grows from the kaolin mineral, and both phases show close orientation relationships. The presence of parallel intergrowths of pyrophyllite and muscovite indicate that muscovite also grew from the kaolin mineral. Nevertheless, the composition of muscovite suggests that this phase must also form from another precursor, probably Al smectite. The AEM data and textural relationships between pyrophyllite and muscovite reveal the presence of two generations of muscovite and suggest that Na-rich muscovite recrystallized into a Na-free muscovite and paragonite.
The accurate crystal chemistry of ferric smectites from the lateritic nickel ore of Murrin Murrin (Western Australia). II. Spectroscopic (IR and EXAFS) approaches
Authors: Gaudin A. , Petit S. , Rose J. , Martin F. , Decarreau A. , Noack Y. , Borschneck D. 
Published: January 2005

AbstractFe-rich smectites from lateritic weathering profiles have previously been studied by XRD, ICP-AES, SEM-EDX and TEM-EDX analyses (Gaudinet al., 2004). These smectites exhibit intermediate chemistries between five end-members: Al-Fe beidellites, Al-Fe montmorillonites and Mg+Ni-saponite. The spectroscopic study by FTIR and XAS of these smectites reveals that: (1) tetrahedral Fe3+is near or below the detection limit (0.05 cation for 4Si); (2) the large chemical variability is due to substitution of the three major cations (Fe, Al, Mg) within adjacent octahedra; (3) Ni is not concentrated in another clay phase such as Ni-kerolite and is located in the octahedral sheets of smectite; (4) octahedral cations are not randomly distributed but ordered in separated Fe, Al, Mg, Ni clusters; (5) the Mg-Ni saponite end-member actually appears as small trioctahedral clusters of Mg and Ni distributed within the dioctahedral smectite.
Variations in the chemical composition of illite from five geothermal fields: a possible geothermometer
Authors: Battaglia S. 
Published: January 2005

AbstractPrevious attempts to use illite as a geothermometer have failed: no general relation between the mineral's chemical composition and temperature of crystallization has been found. Here, chemical compositions of 27 illite samples from five different geothermal fields (the data on four of which were drawn from the literature) were compared with their crystallization temperatures. As previously reported by Cathelineau (1988), the K content was found to be the only variable yielding a suitable correlation, but only when applied to one geothermal field; when various geothermal systems were considered, the correlation weakened considerably. Introduction of a correction algorithm to the K content of the illite has made it possible to draw a single line to fit the data from all the studied samples, yielding a good correlation coefficient (r = 0.84).
Gap-junction channels inhibit transverse propagation in cardiac muscle
Authors: Sperelakis Nicholas , Ramasamy Lakshminarayanan 
Published: January 2005

AbstractThe effect of adding many gap-junctions (g-j) channels between contiguous cells in a linear chain on transverse propagation between parallel chains was examined in a 5 × 5 model (5 parallel chains of 5 cells each) for cardiac muscle. The action potential upstrokes were simulated using the PSpice program for circuit analysis. Either a single cell was stimulated (cell A1) or the entire chain was stimulated simultaneously (A-chain). Transverse velocity was calculated from the total propagation time (TPT) from when the first AP crossed a Vm of -20 mV and the last AP crossed -20 mV. The number of g-j channels per junction was varied from zero to 100, 1,000 and 10,000 (Rgj of ∞, 100 MΩ, 10 MΩ, 1.0 MΩ, respectively). The longitudinal resistance of the interstitial fluid (ISF) space between the parallel chains (Rol2) was varied between 200 KΩ (standard value) and 1.0, 5.0, and 10 MΩ. The higher the Rol2 value, the tighter the packing of the chains. It was found that adding many g-j channels inhibited transverse propagation by blocking activation of all 5 chains, unless Rol2 was greatly increased above the standard value of 200 KΩ. This was true for either method of stimulation. This was explained by, when there is strong longitudinal coupling between all 5 cells of a chain awaiting excitation, there must be more transfer energy (i.e., more current) to simultaneously excite all 5 cells of a chain.