the main goal of this paper is to introduce and study a new class of function via the notions of $e$-$theta$-open sets and $e$-$theta$-closure operator which are defined by özkoç and aslım cite{10} called weakly $er$-open functions and $e$-$theta$-open functions. moreover, we investigate not only some of their basic properties but also their relationships with other types of already existing to...

We construct an algebraic distributive lattice D that is not isomorphic to the congruence lattice of any lattice. This solves a long-standing open problem, traditionally attributed to R. P. Dilworth, from the forties. The lattice D has compact top element and אω+1 compact elements. Our results extend to any algebra possessing a polynomially definable structure of a joinsemilattice with largest ...

An element of an effectively given domain is computable iff its basic Scott open neighbourhoods are recursively enumerable. We thus refer to computable elements as Scott computable and define an element to be Lawson computable if its basic Lawson open neighbourhoods are recursively enumerable. Since the Lawson topology is finer than the Scott topology, a stronger notion of computability is obta...

The incorporation of Ti plasmid sequences, the T-DNA, into the genomes of dicotyledenous plants causes the formation of tumors. Here we report the nucleotide sequence of one of the T-DNA "oncogenes", the transcript 2 gene of pTiA6 and we further characterize the 2.7 Kb element that has spontaneously inserted into this gene in plasmid pTiA66. The results indicate that the transcript 2 portion of...

The F elements of Drosophila melanogaster belong to the superfamily of long interspersed nucleotide element retrotransposons. To date, F-element transcription has not been detected in flies. Here we describe the isolation of a member of the F-element family, termed Fex, which is transcribed in specific cells of the female and male germ lines and in various tissues during embryogenesis of D. mel...

The Ty element of yeast is a member of a class of eukaryotic transposons which bear a striking resemblance to retroviral proviruses in their structure and expression strategies (1,2). A direct comparison can be drawn between the production of a fusion protein encoded by Ty, resulting from a frameshift event which fuses two out-of-phase open reading frames TYA and TYB, and the production of Pr18...