We show that each element in the semigroup $S_n$ of all $n \times n$ non-singular upper (or lower) triangular stochastic matrices is generated by the infinitesimal elements of $S_n$, which form a cone consisting of all $n \times n$ upper (or lower) triangular intensity matrices.
Our previous research was devoted to the problem of determining the primitive periods of the sequences (Gn mod p t )∞ n=1 where (Gn)∞ n=1 is a Tribonacci sequence defined by an arbitrary triple of integers. The solution to this problem was found for the case of powers of an arbitrary prime p ≠ 2, 11. In this paper, which could be seen as a completion of our preceding investigation, we find solution for the case of singular primes p = 2, 11.
Our research was inspired by the relations between the primitive periods of sequences obtained by reducing Tribonacci sequence by a given prime modulus p and by its powers p t , which were deduced by M. E. Waddill. In this paper we derive similar results for the case of a Tribonacci sequence that starts with an arbitrary triple of integers.
The glutathione S-transferases (GSTs) are a family of multifunctional enzymes involved in cellular detoxification. The aim of this study was to evaluate the effect of albendazole - drug of choice for trichinellosis - on the total activity and kinetics of cytosolic GST in the mouse intestines during experimental trichinellosis. Our results showed a statistically significant decrease in the total GST activity both in the small and large intestines of the mice infected with the nematode Trichinella spiralis (Owen, 1835) and treated with albendazole, compared with the control mice that were infected but untreated with the drug. Furthermore, albendazole administration modified the kinetics of substrate saturation of GST in the intestines of the infected mice because the drug caused changes in Michaelis constant values of this enzyme. Based on our observations, we suggest that the quaternary structure of GST from the mouse intestines is impacted by this drug during trichinellosis.
During parasitological surveys in the Okavango Delta and Panhandle in Botswana, two species of climbing perches belonging to the family Anabantidae were investigated for ectoparasites. The fishes were the blackspot climbing perch, Microctenopoma intermedium (Pellegrin) and the manyspined climbing perch, Ctenopoma multispine Peters. Five trichodinid species were found from the skin, fins and gills of these anabantids. One is a known species, i.e., Trichodina microspina Van As et Basson, 1992, for which a comparative description is provided. Four other species are described as new species using silver impregnation, i.e., Trichodina labyrinthipiscis sp. n., Trichodina anabantidarum sp. n., Tripartiella microctenopomae sp. n., and Tripartiella ctenopomae sp. n.
During surveys of parasites of the whitemouth croaker Micropogonias furnieri (Desmarest) and the mullet Mugil platanus Günther from Samborombón Bay, Argentina, Trichodina puytoraci, T. lepsii, T. jadranica, T. murmanica, Diparitella simplex and Trichodina scalensis sp. n. were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. This study is the first formal report of these trichodinids from the southwest Atlantic Ocean, and the description of a new species from M. platanus.
Rhabdomyosarcoma (RMS) is a malignant tumour of soft tissues, occurring mainly in children and young adults. RMS cells derive from muscle cells, which due to mutations and epigenetic
modifications have lost their ability to differentiate. Epigenetic modifications regulate expression of genes responsible for cell proliferation, maturation, differentiation and apoptosis. HDAC inhibitors suppress histone acetylation; therefore, they are a promising tool used in cancer therapy. Trichostatin A (TsA) is a
pan-inhibitor of HDAC. In our study, we investigated the effect of TsA on RMS cell biology. Our findings strongly suggest that TsA inhibits RMS cell proliferation, induces cell apoptosis, and reactivates tumour cell differentiation. TsA up-regulates miR-27b expression, which is involved in the process of myogenesis. Moreover, TsA increases susceptibility of RMS cells to routinely used chemotherapeutics. In conclusion, TsA exhibits anti-cancer properties, triggers differentiation, and thereby can complement an existing spectrum of chemotherapeutics used in RMS therapy. and Corresponding author: Maciej Tarnowski