On the Existence of Configurations of Subspaces in a Hilbert Space with Fixed Angles

For a class of $*$-algebras, where $*$-algebra $A_{\Gamma,\tau}$ is generated by projections associated with vertices of graph $\Gamma$ and depends on a parameter $\tau$ $(0 < \tau \leq 1)$, we study the sets $\Sigma_\Gamma$ of values of $\tau$ such that the algebras $A_{\Gamma,\tau}$ have nontrivial $*$-representations, by using the theory of spectra of graphs. In other words, we study such values of $\tau$ that the corresponding configurations of subspaces in a Hilbert space exist.Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

Mъртви зони в кохлеата

Авторите разглеждат проблема на наличие на мъртви области в кохлеата, при които се установява минимален праг на слуха при тоналната прагова аудиометрия. Определянето на мъртви зони в кохлеата разширява диагностичните възможности и клиничните подходи при пациенти с високочестотно намаление на слуха. При тези пациенти вътрешните слухови клетки функционират толкова лошо, че могат да се възприемат като мъртви и не могат да превърнат механичната вибрация в електрически сигнал към слуховия нерв.При рутинното изследване пациентите реагират различно при определяне на прага във високочестотната област. При някои пациенти увеличаването на сигнала подобрява говорната разбираемост, докато при други пациенти се влошава разбираемостта и поносимостта към усилен сигнал. Субективно те съобщават за наличие на изкривен сигнал, шум и други неслухови усещания. Мъртвите зони се наблюдават както при пациенти с вродена или придобити слухови увреждания и съществуват независимо от възрастта на пациента. За установяването на мъртвите зони в кохлеата са необходими нови тестове, а не само аудиометрия. Установяването на тези кохлеарни промени ни позволява по-добра диагностика и различен подход при тези пациенти.-----------------------------------------The aim of this article is to introduce the problem on cochlear dead regions. It is important to know the concept of cochlear dead regions to make the adequate diagnosis and clinical implications to the patients with high frequency sensoneural hearing loss. Some hearing-impaired individuals have regions of inner hair cells (IHCs) and/or associated neurons that function so poorly, that they can be considered dead, i.e., the mechanical vibration at a particular region of the basilar membrane cannot be transduced into an electrical signal in the auditory nerve. Clinical procedures for the diagnosis of DRs are based on the identification of off-frequency listening.The different patient groups have distinctly different reactions of to high-frequency emphasis. For some patient we need maximum high-frequency energy for speech intelligibility, while others perform better with a narrower bandwidth. Subjective reports of noise or distortion can be taken as an indication that a DR may be present but they are not a reliable method of diagnosing a DR. There is evidence that DRs can occur in adults and children with an acquired or congenital hearing impairment. It is not possible to identify DRs reliably without the use of further test procedures other than pure tone audiometry. The existence of dead regions has given us a better understanding of the impaired ear and also a tool for diagnosing the nature of the disorder in the inner ea

On the Interoperability between Interval Software

The increased appreciation of interval analysis as a powerful tool for controlling round-off errors and modelling with uncertain data leads to a growing number of diverse interval software. Beside in some other aspects, the available interval software differs with respect to the environment in which it operates and the provided functionality. Some specific software tools are built on the top of other more general interval software but there is no single environment supporting all (or most) of the available interval methods. On another side, most recent interval applications require a combination of diverse methods. It is difficult for the end-users to combine and manage the diversity of interval software tools, packages, and research codes, even the latter being accessible. Two recent initiatives: [1], directed toward developing of a comprehensive full-featured library of validated routines, and [3] intending to provide a general service framework for validated computing in heterogeneous environment, reflect the realized necessity for an integration of the available methods and software tools. It is commonly understood that quality comprehensive libraries are not compiled by a single person or small group of people over a short time [1]. Therefore, in this work we present an alternative approach based on interval software interoperability. While the simplest form of interoperability is the exchange of data files, we will focus on the ability to run a particular routine executable in one environment from within another software environment, and vice-versa, via communication protocols. We discuss the motivation, advantages and some problems that may appear in providing interoperability between the existing interval software. Since the general-purpose environments for scientific/technical computing like Matlab, Mathematica, Maple, etc. have several features not attributable to the compiled languages from one side and on another side most problem solving tools are developed in some compiled language for efficiency reasons, it is interesting to study the possibilities for interoperability between these two kinds of interval supporting environments. More specifically, we base our presentation on the interoperability between Mathematica [5] and external C-XSC programs [2] via MathLink communication protocol [4]. First, we discuss the portability and reliability of interval arithmetic in Mathematica. Then, we present MathLink technology for building external MathLink-compatible programs. On the example of a C-XSC function for solving parametric linear systems, called from within a Mathematica session, we demonstrate some advantages of interval software interoperability. Namely, expanded functionality for both environments, exchanging data without using intermediate files and without any conversion but under dynamics and interactivity in the communication, symbolic manipulation interfaces for the compiled language software that often make access to the external functionality from within Mathematica more convenient even than from its own native environment. Once established, MathLink connection to external interval libraries or problem-solving software opens up an array on new possibilities for the latter. References: [1] G. Corliss, R. B. Kearfott, N. Nedialkov, S. Smith: Towards an Interval Subroutine Library, Workshop on Reliable Engineering Computing, Svannah, Georgia, USA, Feb. 22-24, 2006. [2] W. Hofschuster: C-XSC: Highlights and new developments. In: Numerical Validation in Current Hardware Architectures. Number 08021 Dagstuhl Seminar, Internationales Begegnungs- und Forschungszentrum f"ur Informatik, Schloss Dagstuhl, Germany, 2008. [3] W. Luther, W. Kramer: Accurate Grid Computing, 12th GAMM-IMACS Int. Symposium on Scientific Computing, Computer Arithmetic and Validated Numerics (SCAN 2006), Duisburg, Sept. 26-29, 2006. [4] Ch. Miyaji, P. Abbot eds.: Mathlink: Network Programming with Mathematica, Cambridge Univ. Press, Cambridge, 2001. [5] Wolfram Research Inc.: Mathematica, Version 5.2, Champaign, IL, 2005

Access to Social Protection by Immigrants, Emigrants and Resident Nationals in the Russian Federation

This chapter discusses the general legal framework regulating Russia’s welfare system and access for national citizens, foreigners residing in the country, and national citizens residing abroad to social benefits in five policy areas: unemployment, health care, family benefits, pensions, and guaranteed minimum resources. Our analysis shows that the eligibility of Russian nationals for social benefits depends either on their employment status and contribution record (for pensions and other social insurance benefits), or their residence status (for social assistance and healthcare). The overall level of social protection of citizens residing in different parts of the country may differ substantially due to the decentralized structure of the social protection system in Russia. The rights of foreign residents to social security benefits are essentially the same as those of the nationals, as long as they are legally employed and make social security contributions. However, there are two major exceptions: pensions and unemployment benefits. Social assistance benefits provided at the regional level are typically available to all legal residents, foreigners included, with few exceptions. When deciding to permanently move abroad, Russian citizens lose their entitlement to claim social benefits from Russia, apart from acquired contributory public pensions

Neugezüchtete flugbrandresistente Gerste aus Bulgarien

Our study presents a part of the long-term program for resistance breeding to smuts in barley in Bulgaria. 56 dihaploid lines were derived from F1-hybrids of two barley crosses between resistant and susceptible Bulgarian and foreign cultivars bearing the resistant genes Run12 and Run13. The DH progenies were tested in 3 generations for loose smut resistance on the field and in the lab with the embryotest. 10 resistant DH-progenies with gene Run12 and 16 resistant DH-progenies with Run13 were selected and agronomically characterised for new cultivar development