Temperature-sensitive periods were determined by application of temperature shifts and shocks to 3 temperature-sensitive cell division arrest (cda) mutants of Tetrahymena thermophila. A restrictive temperature, 36 degrees C, was found at which all 3 mutants are fully penetrant, yet other physiological effects are minimal. At this temperature, the temperature-sensitive period of cdaC2 is a uniqu...

Abstract The Urmia Lake National Park (NW Iran) represents a unique ecosystem owing to special ecological conditions prevailing the region. The Urmia Lake National Park comprises a range of normal to extreme environments, with variable range of salinity between 120-300 g/L. The present study was aimed to characterize ascomycetous yeast mycobiota inhabiting hypersaline soils in this region. Soi...

We show that the norm graph constructed in [13] with n vertices about 1 2n 2−1/t edges, which contains no copy of Kt,(t−1)!+1, does not contain a copy of Kt+1,(t−1)!−1.

In this paper we investigate the closure ~-* under substitution-composition of a family of graphs ~,, defined by a set Lr of forbidden configurations. We first prove that ~-* can be defined by a set L~* of forbidden subgraphs. Next, using a counterexample we show that ~* is not necessarily a finite set, even when .~ is finite. We then give a sufficient condition for ~* to be finite and a simple...

Logical structures for modeling agents’ reasoning about unawareness are presented where it can hold simultaneously that: (i) agents’ beliefs about whether they are fully aware need not be veracious with partitional information; and (ii) the agent is fully aware if and only if she is aware of a fixed domain of formulae. In light of (ii), all states are deemed “possible”. Semantics operate in two...

We characterise t-perfect plane triangulations by forbidden induced subgraphs. As a consequence, we obtain that a plane triangulation is h-perfect if and only if it is perfect.

A circle graph is the intersection graph of a family of chords on a circle. There is no known characterization of circle graphs by forbidden induced subgraphs that do not involve the notions of local equivalence or pivoting operations. We characterize circle graphs by a list of minimal forbidden induced subgraphs when the graph belongs to one of the following classes: linear domino graphs, P4-t...

In this note, we prove that all 2× 2 monotone grid classes are finitely based, i.e., defined by a finite collection of minimal forbidden permutations. This follows from a slightly more general result about certain 2× 2 having two monotone cells in the same row.

identification  of clinically  significant  nocardia  species  is essential  for the definitive diagnosis, predict antimicrobial susceptibility, epidemiological purposes,  and  for  an  effective  treatment.   conventional   identification   of nocardia species in routine medical laboratories which is based on phenotypic (cellular morphology, colonial characteristics), biochemical and enzymatic...

Let k be a natural number. We introduce k-threshold graphs. We show that there exists anO(n) algorithm for the recognition of k-threshold graphs for each natural number k. k-Threshold graphs are characterized by a finite collection of forbidden induced subgraphs. For the case k = 2 we characterize the partitioned 2threshold graphs by forbidden induced subgraphs. We introduce restricted, and spe...