Properties of Neutral Charmed Mesons in Proton--Nucleus Interactions at 70 GeV

The results of treatment of data obtained in the SERP-E-184experiment "Investigation of mechanisms of the production of charmed particles in proton-nucleus interactions at 70 GeV and their decays" by irradiating the active target of the SVD-2 facility consisting of carbon, silicon, and lead plates, are presented. After separating a signal from the two-particle decay of neutral charmed mesons and estimating the cross section for charm production at a threshold energy {\sigma}(c\v{c})=7.1 \pm 2.4(stat.) \pm 1.4(syst.) \mub/nucleon, some properties of D mesons are investigated. These include the dependence of the cross section on the target mass number (its A dependence); the behavior of the differential cross sections d{\sigma}/dpt2 and d{\sigma}/dxF; and the dependence of the parameter {\alpha} on the kinematical variables xF, pt2, and plab. The experimental results in question are compared with predictions obtained on the basis of the FRITIOF7.02 code.Comment: 9 pages, 9 figures,3 table

Visual ecology of aphids – a critical review on the role of colours in host finding

We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms. Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region. We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours that are not likely to hold. Finally we also discuss the implications for developing and optimising strategies of aphid control and monitoring

Ammonite Faunal Dynamics Across Bio-Events During the Mid-and Late Cretaceous Along the Russian Pacific Coast

Jagt−Yazykova, E.A. 2012. Ammonite faunal dynamics across bio−events during the mid − and Late Cretaceous along th

Choice of a way to verify space-occupying lesions of the breast at a preoperative stage

Preoperative verification of breast cancer (BC) is a necessary stage of diagnosis. The main method for obtaining materials is fine-needle aspiration biopsy that is of low informative value in a number of cases. Histological biopsy of nonpalpable breast masses extends the verification capabilities of accurate diagnosis and determines the choice and tactics of combination and complex treatments in patients with BC just at a preoperative stage, and, in case of detection of a benign tumor, enables one to abandon sector resection with an urgent histological study

The spin-transition properties of Fe(III) complexes with hetarylformazan in an ion-exchange polymer: An EPR study

For the first time, the EPR method was used to reveal and study the special features of spin-transition processes between high-spin and low-spin iron(III) complexes with hetarylformazans immobilized on an ion-exchange polymer. An analysis of completely reversible temperature dependences of EPR line positions, widths, and integral intensities in the spectra of high-spin and low-spin complexes allowed four temperature intervals to be identified. These intervals corresponded to preparative periods of spin-transition processes (450-275 K, intervals I and II), their appearance (275-230 K, interval III), and occurrence (230-100 K, interval IV). Local concentrations and spin exchange frequencies in clusters were estimated. Effects related to high-spin complex EPR signal shifts during temperature changes and to the duration of sample storage were revealed. High-spin complexes were found to be very sensitive to external actions, as distinct from very stable low-spin complexes. Experimental EPR observations obtained for ion-exchange polymer satisfied the concept of the nucleation and growth of domains in the spin-transition process. © 2010 Pleiades Publishing, Ltd.This work was financially supported by the Russian Foundation for Basic Research, project no. 08 02 01348