The effect of atenolol, propranolol, trifluoperazine, and caffeine on the occurrence of meiotic diploid and disomic products in Saccharomyces cerevisiae was investigated. We demonstrated that atenolol, propranolol, and trifluoperazine reduce the occurrence of meiotic diploid products and that propranolol also slightly decreases the spontaneous frequency of disomics. On the other hand, caffeine ...

Three pollen test systems to detect the induction of nondisjunction in maize are actively being explored. (1) Each member of a tetrad of haploid microspores produced by meiosis contains a single chromosome 6 which carries the only nucleolar organizing region in the maize genome. Thus, each member of a normal tetrad contains one nucleolus. If nondisjunction took place at the first or second meio...

The first aneuploid strains of Dictyostelium discoideum have been unambiguously characterized, using cytological and genetic analysis. Three independently isolated, but genetically similar, fragment chromosomes have been observed in segregants from diploids formed between haploid strains derived from the NC4 and V12 isolates of D. discoideum. Once generated, the fragment chromosomes, all of whi...

We investigate the structure of the Minkowski sum of standard simplices in R. In particular, we investigate the one-dimensional structure, the vertices, their degrees and the edges in the Minkowski sum polytope. 2000 MSC: 52B05, 52B11, 05C07.

Let A be a finite nonempty set of integers. An asymptotic estimate of several dilates sum size was obtained by Bukh. The unique known exact bound concerns the sum |A + k ·A|, where k is a prime and |A| is large. In its full generality, this bound is due to Cilleruelo, Serra and the first author. Let k be an odd prime and assume that |A| > 8kk. A corollary to our main result states that |2 · A +...

 In order to have a sustainable management on Persian sturgeon as a highly commercial species in the South Caspian Sea, we need to identify its population structure and the level as well as its conservation status in their natural habitat. To develop a conservation program for this all Caspian Sea' sturgeon species it requires knowledge of its genetic diversity using reliable molecular marker t...

Recently, Eisenbrand, Pach, Rothvoß, and Sopher studied the function M(m, n), which is the largest cardinality of a convexly independent subset of the Minkowski sum of some planar point sets P and Q with |P | = m and |Q| = n. They proved that M(m, n) = O(m2/3n2/3+m+n), and asked whether a superlinear lower bound exists for M(n, n). In this note, we show that their upper bound is the best possib...

Drought stress is a serious adverse factor limiting growth and productivity of sunflower. Evaluation of defense systems is important for producing resistant cultivars. In this study, some agro-morphological and molecular characteristics of six sunflower lines were evaluated under normal and irrigation at 40 and 60% of field capacity in randomized complete block design (RCBD). The results showed...

The important human pathogen Candida albicans possesses an unusual form of gene regulation, in which the copy number of an entire specific chromosome or a large portion of a specific chromosome changes in response to a specific adverse environment, thus, insuring survival. In the absence of the adverse environment, the altered portion of the genome can be restored to its normal condition. One m...

Imbalances of gene expression in aneuploids, which contain an abnormal number of chromosomes, cause a variety of growth and developmental defects. Aneuploid cells of the fission yeast Schizosaccharomyces pombe are inviable, or very unstable, during mitotic growth. However, S. pombe haploid cells bearing minichromosomes derived from the chromosome 3 can grow stably as a partial aneuploid. To add...