A cis-Acting Viral Protein Is Not Required for the Replication of a Coronavirus Defective-Interfering RNA

AbstractMouse hepatitis virus (MHV), a coronavirus, generates defective-interfering (DI) RNAs of different sizes during passages at high multiplicities of infection. All MHV DI RNAs characterized so far contain an open reading frame (ORF) encoding a fused viral protein; in addition, DI RNAs with a long ORF have a competitive advantage over those with a shorter ORF. These findings suggest that DI RNA replication may require an ORF encoding a cis-acting viral protein. In this study, we used a naturally occurring DI RNA and inserted a 12-nucleotide (nt) amber-mutation linker at various positions to truncate the ORF. Most of the mutants replicated as well as the wild-type DI RNA, irrespective of the presence or absence and the length of the ORF in the RNA. Sequence analysis showed that all of the mutants retained the insertional mutations even after two viral passages in tissue culture, establishing that the mutant DI RNAs replicated. We have further introduced two 3-nucleotide substitutions of the first two AUG codons of the ORF, thus completely closing the ORF. This DI RNA replicated as well as the wild-type DL but, after a single passage, the majority of the mutant RNAs was replaced by recombinant RNAs which contain a restored functional ORF. However, an additional insertion of a 12-nt amber-mutation linker downstream of the AUG substitutions prevented recombination, and the DI RNA still replicated. These data indicate that DI RNA replication does not require a DI-specific ORF encoding cis-acting viral proteins and that a 12-nucleotide insertion could prevent or delay the occurrence of RNA recombination, suggesting the importance of direct or indirect RNA alignment in homologous RNA recombination

Horizontal transfer of boron by the Formosan subterranean termite (Coptotermes formosanau Shiraki) after feeding on treated wood

The goal of the present study was to determine whether Coptotermes formosanus Shiraki workers exposed to boron-treated wood were capable of transferring quantifiable amounts of boron to non-exposed nestmates. This effect is called horizontal transfer. Borates are not repellent to termites, nor do they cause rapid mortality, making them excellent candidates for the study of horizontal transfer. In the present study, C. formosanus workers were collected from field colonies maintained in Honolulu, Hawaii and dyed with Sudan Red 7B over a 7-day period. These termites then underwent a 3-day exposure period to one of two types of composite board, either an experimental formulation of zinc borate and anhydrous boric acid or an untreated composite board. Treated termites were placed with an equal number of untreated termites for either 5 or 10 days; sham-dyed donors and recipients were used to control for possible effects of the dye. Horizontal transmission of boron and toxic effects were assessed based on termite wet weight, percent survival, and boron content. Horizontal transfer of boron was noted at both 5 and 10 days over those levels reported in untreated, field-caught termites from the same colony (ca. 7 μg boron g termites). After 5 days, boron content was elevated in both dyed donor and recipient termites (ca. 92 and 38 μg boron g dyed termites, respectively), as well as in undyed donors and recipients (ca. 84 and 30 μg boron g undyed termites). The same pattern was observed after 10 days in both dyed donor and recipient termites (ca. 61 and 46 μg boron g , respectively) and undyed donor and recipient termites (59 and 24 μg boron g , respectively). Increased boron content of recipient termites after exposure to donor termites (fed on treated wood) demonstrated horizontal transfer of boron

Exact trace formulae for a class of one-dimensional ray-splitting systems

Based on quantum graph theory we establish that the ray-splitting trace formula proposed by Couchman {\it et al.} (Phys. Rev. A {\bf 46}, 6193 (1992)) is exact for a class of one-dimensional ray-splitting systems. Important applications in combinatorics are suggested.Comment: 14 pages, 3 figure

Flavor Asymmetry of the Polarized Light Sea: Models vs. Data

The flavor asymmetry of the polarized light sea, $\Delta \bar u - \Delta \bar d$, discriminates between different model calculations of helicity densities. We show that the chiral chromodielectric model, differently from models based on a $1/N_c$ expansion, predicts a small value for this asymmetry, what seems in agreement with preliminary HERMES data.Comment: 10 pages, 3 figure

Hepatitis C Virus NS5B Protein Is a Membrane-Associated Phosphoprotein with a Predominantly Perinuclear Localization

AbstractHepatitis C virus NS5B protein is an RNA-dependent RNA polymerase. To investigate the properties and function of this protein, we have expressed the NS5B protein in insect and mammalian cells. NS5B was found to be present as fine speckles in the cytoplasm, particularly concentrated in the perinuclear region, suggesting its association with the nuclear membrane, the endoplasmic reticulum, or the Golgi complex. This conclusion was supported by the biochemical demonstration that NS5B was associated with the membranes in the cells. Furthermore, it was shown that NS5B protein is a phosphoprotein. These properties may be related to its function as an RNA polymerase

Path-Integral bosonization of a non-local interaction and its application to the study of 1-d many-body systems

We extend the path-integral approach to bosonization to the case in which the fermionic interaction is non-local. In particular we obtain a completely bosonized version of a Thirring-like model with currents coupled by general (symmetric) bilocal potentials. The model contains the Tomonaga-Luttinger model as a special case; exploiting this fact we study the basic properties of the 1-d spinless fermionic gas: fermionic correlators, the spectrum of collective modes, etc. Finally we discuss the generalization of our procedure to the non-Abelian case, thus providing a new tool to be used in the study of 1-d many-body systems with spin-flipping interactions.Comment: 26 pages LATEX, La Plata 94-0

Efficient Algorithm on a Non-staggered Mesh for Simulating Rayleigh-Benard Convection in a Box

An efficient semi-implicit second-order-accurate finite-difference method is described for studying incompressible Rayleigh-Benard convection in a box, with sidewalls that are periodic, thermally insulated, or thermally conducting. Operator-splitting and a projection method reduce the algorithm at each time step to the solution of four Helmholtz equations and one Poisson equation, and these are are solved by fast direct methods. The method is numerically stable even though all field values are placed on a single non-staggered mesh commensurate with the boundaries. The efficiency and accuracy of the method are characterized for several representative convection problems.Comment: REVTeX, 30 pages, 5 figure

Novel family- and genus-specific DNA markers in Mugilidae

In this study, we identified novel family- and genus-specific DNA markers in Mugilidae fish. Genomic DNA was isolated from the blood of fish of 15 families and eighty (80) random primers were used for random amplified polymorphic DNA (RAPD) fingerprinting. When the primer OPAV04 was employed, a novel specific PCR product was observed in the Mugilidae family. In addition, another novel specific PCR product was also observed in the Liza genus while using primer OPAV10. Sequencing analysis revealed that the novel family- and genus-specific DNA fragments were 857 and 419 bp, respectively, and no similar sequences were found in GenBank. Two primers sets were designed based on the family- and genus-specific sequences to confirm the RAPD results and the 571 and 187 bp predicted bands were successfully amplified by PCR. Intriguingly, these two novel specific DNA markers were also effectively used for terrestrial and aquatic animal discrimination. Therefore, the novel family- and genus-specific DNA markers identified in this study can be used as an effective tool for rapid and accurate determination of the Mugilidae family and Liza genus, and even for cross-species identification

The contents and forms of solid-phase species of radioactive strontium and cesium in Taiwan soils

This study was to investigate the activities and contents of Cs-137 in the profiles of selected arable and forest soils in Taiwan and various solid-phase species of Sr-85 and Cs-137 in selected arable soils in Taiwan. The gamma (gamma) ray spectra of the collected soil samples and some of the soils amended with Sr-85 and Cs-137 were measured. The data indicate that the arable soils from Sanhsing series, Sanhsing Township and Chuangwei series, Chuangwei Township, Ilan County, and from Tunglochuan series, Pinglin Township, Taipei County shows significantly higher radioactivity of Cs-137 ( ND - 11.0 +/- 0.2 Bq kg(-1)). Furthermore, the radioactivity of Cs-137 in the mountain soils ( 1.24 +/- 0.07 - 42 +/- 1 Bq kg(-1)) from Yuanyang Lake Nature Preserve among Ilan, Taoyuan, and Hsinchu Counties is the highest among the investigated mountain forest soils. This may be mainly attributed to the fact that Ilan County is located in the northeastern part of Taiwan and faces the northeastern and northern seasonal winds with lots of precipitation annually from mid-autumn through mid-spring next year and is receiving greater amount of fallouts yearly. Due to longer reaction period (> 3 y) of Cs-137 with soil components, Cs-137 was mainly in the forms bound to oxides and to organic matter in the soil amended with Cs-137 and in the soil contaminated with Cs-137. On the contrary, due to shorter reaction period (< 60 d) of Sr-85 with soil components, Sr-85 was mainly in exchangeable form and partially in the forms bound to carbonates and oxides in the soils amended with Sr-85

Shadowing Effects on Vector Boson Production

We explore how nuclear modifications to the nucleon structure functions, shadowing, affect massive gauge boson production in heavy ion collisions at different impact parameters. We calculate the dependence of $Z^0$, $W^+$ and $W^-$ production on rapidity and impact parameter to next-to-leading order in Pb+Pb collisions at 5.5 TeV/nucleon to study quark shadowing at high $Q^2$. We also compare our Pb+Pb results to the $pp$ rapidity distributions at 14 TeV.Comment: 25 pages ReVTeX, 12 .eps figures, NLO included, version accepted for publication in Physical Review