In human immunodeficiency virus type 1-infected cells, the efficient expression of viral proteins from unspliced and singly spliced RNAs is dependent on two factors: the presence in the cell of the viral protein Rev and the presence in the viral RNA of the Rev-responsive element (RRE). We show here that the HIV-1 Rev/RRE system can increase the expression of avian leukosis virus (ALV) structura...

A vision-based approach to obstacle avoidance for autonomous land vehicle (ALV) navigation in indoor environments is proposed. The approach is based on the use of a pattern recognition scheme, the quadratic classifier, to find collision-free paths in unknown indoor corridor environments. Obstacles treated in this study include the walls of the corridor and the objects that appear in the way of ...

It is a pleasant change to write about viruses that might have emerged but haven't. In this issue, Hussain and colleagues at the Centers for Disease Control and Prevention, the U.S. Department of Agriculture, and Harvard University report that recipients of measles, mumps, and rubella (MMR) vaccine show no evidence of infection by endogenous avian retroviruses, even though viral genomes and rev...

Avian leukosis viruses (ALVs) in poultry may induce a variety of deleterious effects including tumors, increased mortalities, growth retardation and decrease in egg size and production that led to considerable economic losses. The identification of avian leukosis viruses (ALVs) in imported Marek’s disease (MD) vaccines has raised concern about transmission of these retroviruses to vaccine recip...

This report describes the current state-of-the-art in Autonomous Land Vehicle (ALV) systems and technology. Five functional technology areas are identified and addressed. For each a brief, subjective, preface is first provided which envisions the necessary technology for the deployment of an operational ALV system. Subsequently, a detailed literature review is provided to support and elaborate ...

A genomic DNA library was constructed, in a bacteriophage 2 vector, from line 0 chick embryo fibroblasts (CEFs) infected with HPRS-103, an exogenous avian leukosis virus (ALV; envelope subgroup J) recently isolated from meat-type chickens, The library was screened at high stringency using a full length RAV-1 (subgroup A) proviral probe. From 106 plaques, two clones which hybridized strongly to ...

Our objective was to determine whether the cell-associated herpesvirus vaccines used in chickens to control Marek's disease tumors can augment development of lymphoid leukosis (LL) induced by exogenous avian leukosis virus (ALV). Various single or mixed Marek's disease vaccines were inoculated at day 1, and ALV was injected at 1 to 10 days, with chickens of several experimental or commercial st...

So-called fowl glioma is a retroviral infectious disease caused by avian leukosis virus subgroup A (ALV-A). We determined the complete nucleotide sequence of the virus genome. The full-length sequence was consistent with a genetic organization typical of a replication-competent type C retrovirus lacking viral oncogenes. The coding sequences were well conserved with those of replication-competen...

Avian leukosis virus (ALV)-induced osteopetrosis is associated with the accumulation of unintegrated viral DNA in osteoblasts. Viruses constructed from the DNAs of an osteopetrosis-inducing ALV (Br21) and a non-osteopetrosis-inducing ALV (RAV-0) have been used to test for the role of viral genes in the induction of osteopetrosis. Our results map osteopetrotic potential to a 1,400-base-pair regi...