Permian ancestors of Hymenoptera and Raphidioptera

The origin of Hymenoptera remains controversial. Currently accepted hypotheses consider Hymenoptera as the first side branch of Holometabola or sister-group to Mecopteroidea. In contrast, fossils confirm the idea of Martynov that Hymenoptera are related to Megaloptera and Raphidioptera. Hymenoptera have descended along with Raphidioptera from the earliest Megaloptera, the Permian Parasialidae. A related new family, minute Nanosialidae from the Permian of Russia is supposedly ancestral to Raphidioptera. The fusion of the third ovipositor valvulae is shown to be not a synapomorphy of Neuropteroidea. Parasialids and nanosialids bridge the gap between megalopterans and snakeflies; all can be classified into a single order, Panmegaloptera nom. n., including a new suborder Siarapha for Nanosialidae. The earliest megalopterans and their descendants, Raphidioptera and Hymenoptera, have passed through a “miniaturization bottleneck”, likely a common macroevolutionary mechanism.     

Asymmetry in the frequencies of reciprocal recombinants in crosses of T4 phage rIIB mutants]

The frequencies of reciprocal recombinants in crosses between rIIB mutants of T4 phage were shown to differ from each other. In terms of the correction model, this asymmetry of genetic recombination was used to measure the comparative correctability of the mismatched regions to the wild type and to the mutant alleles. The data obtained are in quantitative agreement with the analogous values for the same mismatched regions determined by comparison of the markers located at the same site. This strongly suggests that the asymmetry of genetic recombination in T4 reflects the corresponding difference in rates of correction of the mismatched regions in heteroduplexes in opposite directions.     

Synthesis and antiproliferative activity of a novel N-acyl derivative of doxorubicin]

Doxorubicin was acylated with estrone 3-hemisuccinate. The modified derivative exhibited high antiproliferative activity in vitro toward cell cultures of the MCF-7 human mammary adenocarcinoma and HepG2 human hepatoma.     

Microbial Degradation of Mustard Gas Reaction Masses: Isolation and Selection of Degradative Microorganisms,Analysis of Organic Components of Reaction Masses,and Their Biodegradation

Bacterial strains growing in medium with mustard gas reaction masses (RM) as the carbon source were obtained. Growth cessation in the above medium was caused by the exhaustion of bioutilizable substrates, first of all monoethanolamine (MEA) and ethyleneglycol (EG), rather than by the accumulation of toxic metabolites in the culture liquid or in the cells. The main RM components, 1,4-perhydrothiazines (PHT), formed in the course of chemical detoxication of mustard gas, were identified and analyzed. The predominant component of the PHT mixture was N-(2-hydroxyethyl)-2-methyl-1,4-perhydrothiazine hydrochloride. Concentrations of all the PHT decreased by 50% in the course of culture growth; their destruction was a result of microbial metabolism.     

Arachnids from the Carboniferous of Russia and Ukraine,and the Permian of Kazakhstan

New finds of Late Palaeozoic arachnids, based on three well-preserved carapaces from the Carboniferous of Russia and Ukraine and one complete, albeit poorly preserved, specimen from the Permian of Kazakhstan, are described. The spider genus Arthrolycosa is reported from the Late Carboniferous (Late Pennsylvanian: Kasimovian–Gzhelian) of Chunya in the Tunguska Basin of Siberia; it is the first find of a spider outside the Carboniferous tropics. Another fossil assigned to the same genus comes from the Late Carboniferous (Early Pennsylvanian: Bashkirian) of Kamensk–Shakhtinsky in the Donets Basin of Russia; it is probably the oldest fossil spider known. A thelyphonid (whip scorpion) carapace is described from the Late Carboniferous (Late Pennsylvanian: Kasimovian) of the adjacent Lugansk Province of the Donets Basin of Ukraine.     

A scanning cytophotometer for the analysis of closely contiguous objects

A measuring complex including microscope-photometer and computer is described to be used for scanning of a sample inside of an arbitrary contour. The complex is supplied with a television channel for simultaneous control of the sample and photometric diaphragm, and also with a manual manipulator for setting the boundaries of the informational zone. At the end of scanning the cytophotometric and morphometric data are registered.     

Differential effects of pre and post-payment on neurologists' response rates to a postal survey

Background  

Monetary incentives are an effective way of increasing response rates to surveys, though they are generally less effective in physicians, and are more effective when the incentive is paid up-front rather than when made conditional on completion.