Influence of starvation on selected temperatures in the young of bream, roach and perch [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod No.50, 45-47, 1981]

Works devoted to the influence of starvation on temperature selection by fishes are few and their conclusions are contradictory. This study determined the influence of brief, up to 14 days, starvation on temperature selection by young fishes. The experiments were carried out in August-September 1976 on fingerling bream (Abramis brama L.), roach (Rutilus rutilus L.) and perch (Perca fluviatilis L.) with body lengths of 3-5 cm and weight 0.5-1.2 g. The young fish were caught in the littoral by seine-nets or small drag-nets. Immediately after catching the fish they were put in acclimatization boxes. The period of acclimatization did not exceed 2 days for bream and roach at a temperature of 20 °C and 6 days for perch at 17 °C. Before the start of the experiment and for the first 10 days of the experiment the fish were fed with oligochaetes, earthworms and daphnia, after that feeding discontinued. At the end of a 10-14 day period the giving of food was resumed. The study concludes that the experiments have shown that in the summer season the factor of starvation significantly changes the reaction to the gradient of temperature in young cyprihids - roach and bream

Double parton interactions as a background to associated HW production at the Tevatron

In this paper we study events with W+jets final state, produced in double parton (DP) interactions, as a background to the associated Higgs boson (H) and W production, with H->bbar decay, at the Tevatron. We have found that the event yield from the DP background can be quite sizable, which necessitates a choice of selection criteria to separate the HW and DP production processes. We suggest a set of variables sensitive to the kinematics of DP and HW events. We show that these variables, being used as an input to the artificial neural network, allow one to significantly improve a sensitivity to the Higgs boson production.Comment: 13 pages, 11 figure

Route to the cosmodrome

Photograph of Soviet spacecraft ready for launching with group of eleven cosmonauts alongsid

High specific torque motor for propulsion system of aircraft

This paper proposes an analytical model that considers the torque characteristics for high specific torque synchronous machine with outer rotor and a Halbach permanent magnet array. The distribution of the magnetic field in the air gap is obtained with a linear assumption by solving Neumann’s problem. The analytical model presented in the paper allows preliminary estimation and fast optimization of the machine’s geometry and can be used to develop a first cut design of the machine. The application of the analytical model proposed is demonstrated via the adaptation and modification of a traction machine designed for electrical taxiing to a machine for propulsion of electric aircraft

Invasions of Alien Plant Species in the South Urals: Current State of the Problem

Aim: assessment of the current state of the introduction of alien species into the territory of the Bashkortostan Republic. Objectives: identification of aggressive neophyte invasion centers, mapping their distribution in the region, the description of communities containing such neophytes, assessment of the population, and reproductive characteristics of these species and the development of recommendations about controlling invasive processes. The characteristics of the adventive component of the flora of the Bashkortostan Republic (457 species) are provided in the article. The most aggressive invasive species (Ambrosia trifida, A. psylostachya, Cyclachaena xanthiifolia, Hordeum jubatum, Bidens frondosa, etc.), which take root in sinantropic and natural communities in proportions of between 18% and 99%, are considered. The biomass of invasive plants is up to 6 kg/m2 , while the density is over 1,000 escapes per 1 m2 . Data on the ecology, phytocenotic confinedness and distribution of these species are presented. Ecological harm is connected with the replacement of local plants, the contamination of lands and the allergenicity of the pollen from a number of invasive species. Keywords: South Urals, Bashkortostan Republic, alien species, invasions, controlling number