ЛУЧЕВАЯ ДИАГНОСТИКА АНОМАЛИЙ РАЗВИТИЯ НИЖНЕЙ ПОЛОЙ ВЕНЫ И ЕЕ ПРИТОКОВ

Ultrasonography (US), computer (CT) and magnetic resonance (MRI) tomography - are the basic tools to identify malformations of the Inferior Vena Cava (IVC), which may be congenital or isolated elements of cardiosplenic syndrome that occurs during embryonic development. These vascular malformations diverse by a variety of pathologically formed architectonics, are rather rare, often asymptomatic, or present as venous thrombosis of the lower body. They can also mimic neoplasms and lymphadenopathy in the examined areas. The advantages and limitations of imaging methods in detecting malformations of the IVC and its tributaries are described with a clinical case example. A novel diagnostic algorithm to assess the structure of the IVC, which is extremely important when planning surgical interventions, endovascular diagnostics and therapeutic procedures, is proposed and justified.Ультразвуковое исследование, рентгеновская компьютерная и магнитно-резонансная томография - основные инструменты выявления аномалий строения нижней полой вены (НПВ), которые могут быть изолированным врожденным пороком или элементом кардиоспленического синдрома, возникающего в процессе эмбрионального развития. Эти мальформации представлены разнообразной патологически сформированной сосудистой архитектоникой, встречаются достаточно редко, зачастую протекает бессимптомно или проявляют себя тромбозом вен нижней части тела. Они также могут имитировать наличие новообразований и лимфаденопатии в исследуемых областях. На примере клинического наблюдения в работе описаны достоинства и ограничения методов медицинской визуализации в распознавании аномалий НПВ и ее притоков. Предложен и обоснован отличный от существующего алгоритм применения этих лучевых модальностей для оценки строения системы нижней полой вены, что чрезвычайно важно при планировании оперативных вмешательств, эндоваскулярных диагностических и лечебных процедур

Milestones in the Observations of Cosmic Magnetic Fields

Magnetic fields are observed everywhere in the universe. In this review, we concentrate on the observational aspects of the magnetic fields of Galactic and extragalactic objects. Readers can follow the milestones in the observations of cosmic magnetic fields obtained from the most important tracers of magnetic fields, namely, the star-light polarization, the Zeeman effect, the rotation measures (RMs, hereafter) of extragalactic radio sources, the pulsar RMs, radio polarization observations, as well as the newly implemented sub-mm and mm polarization capabilities. (Another long paragraph is omitted due to the limited space here)Comment: Invited Review (ChJA&A); 32 pages. Sorry if your significant contributions in this area were not mentioned. Published pdf & ps files (with high quality figures) now availble at http://www.chjaa.org/2002_2_4.ht

The Crab Nebula and Pulsar between 500 GeV and 80 TeV: Observations with the HEGRA stereoscopic air Cherenkov telescopes

The Crab supernova remnant has been observed regularly with the stereoscopic system of 5 imaging air Cherenkov telescopes that was part of the High Energy Gamma Ray Astronomy (HEGRA) experiment. In total, close to 400 hours of useful data have been collected from 1997 until 2002. The spectrum extends up to energies of 80 TeV and is well matched by model calculations in the framework of inverse Compton scattering of various seed photons in the nebula including for the first time a recently detected compact emission region at mm-wavelengths. The observed indications for a gradual steepening of the energy spectrum in data is expected in the inverse Compton emission model.The average magnetic field in the emitting volume is determined to be $(161.6\pm0.8mathrm{stat}\pm18_\mathrm{sys}) \mu$G. The presence of protons in the nebula is not required to explain the observed flux and upper limits on the injected power of protons are calculated being as low as 20 % of the total spin down luminosity for bulk Lorentz factors of the wind in the range of $10^4-10^6$.The position and size of the emission region have been studied over a wide range of energies. The position is shifted by 13\arcsec to the west of the pulsar with a systematic uncertainty of 25\arcsec. No significant shift in the position with energy is observed. The size of the emission region is constrained to be less than 2\arcmin at energies between 1 and 10 TeV. Above 30 TeV the size is constrained to be less than 3\arcmin.No indications for pulsed emission has been found and upper limits in differential bins of energy have been calculated reaching typically 1-3 % of the unpulsed component.Comment: 53 pages, 12 figures. Accepted for publication in Astrophysical Journa

Genome Sequence of the Pea Aphid Acyrthosiphon pisum

Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems

Modelling Jets, Tori and Flares in Pulsar Wind Nebulae

In this contribution we review the recent progress in the modelling of Pulsar Wind Nebulae (PWN). We start with a brief overview of the relevant physical processes in the magnetosphere, the wind-zone and the inflated nebula bubble. Radiative signatures and particle transport processes obtained from 3D simulations of PWN are discussed in the context of optical and X-ray observations. We then proceed to consider particle acceleration in PWN and elaborate on what can be learned about the particle acceleration from the dynamical structures called GwispsG observed in the Crab nebula. We also discuss recent observational and theoretical results of gamma-ray flares and the inner knot of the Crab nebula, which had been proposed as the emission site of the flares. We extend the discussion to GeV flares from binary systems in which the pulsar wind interacts with the stellar wind from a companion star. The chapter concludes with a discussion of solved and unsolved problems posed by PWN

Adaptive search and information updating in sequential mate choice

Classical treatments of problems of sequential mate choice assume that the distribution of the quality of potential mates is known a priori. This assumption, made for analytical purposes, may seem unrealistic, opposing empirical data as well as evolutionary arguments. Using stochastic dynamic programming, we develop a model that includes the possibility for searching individuals to learn about the distribution and in particular to update mean and variance during the search. In a constant environment, a priori knowledge of the parameter values brings strong benefits in both time needed to make a decision and average value of mate obtained. Knowing the variance yields more benefits than knowing the mean, and benefits increase with variance. However, the costs of learning become progressively lower as more time is available for choice. When parameter values differ between demes and/or searching periods, a strategy relying on fixed a priori information might lead to erroneous decisions, which confers advantages on the learning strategy. However, time for choice plays an important role as well: if a decision must be made rapidly, a fixed strategy may do better even when the fixed image does not coincide with the local parameter values. These results help in delineating the ecological-behavior context in which learning strategies may spread