Distribution of lipids in non-lamellar phases of their mixtures

We consider a model of lipids in which a head group, characterized by its volume, is attached to two flexible tails of equal length. The phase diagram of the anhydrous lipid is obtained within self-consistent field theory, and displays, as a function of lipid architecture, a progression of phases: body-centered cubic, hexagonal, gyroid, and lamellar. We then examine mixtures of an inverted hexagonal forming lipid and a lamellar forming lipid. As the volume fractions of the two lipids vary, we find that inverted hexagonal, gyroid, or lamellar phases are formed. We demonstrate that the non-lamellar forming lipid is found preferentially at locations which are difficult for the lipid tails to reach. Variations in the volume fraction of each type of lipid tail are on the order of one to ten per cent within regions dominated by the tails. We also show that the variation in volume fraction is correlated qualitatively with the variation in mean curvature of the head-tail interface.Comment: 10 pages, 12 figures (better figures are available upon request), to appear in J. Chem. Phy

Epidemiology of Blastomycosis and Paracoccdioidomycosis

In recent years, an increase of tourist flow, strengthening of social and economic connections between the countries take place. The processes of the world economy globalization, development of international transport systems, and migration of population form preconditions for the spread of new infectious diseases in the territory of Russia and CIS countries. Imported cases of blastomycosis and paracoccidioidomycosis are already registered in many countries of Europe and Asia among persons who returned from endemic countries. Thus, it is likely to find infected persons and patients in Russia. The purpose of our review is to provide data indicating the need for improvement of methods for epidemiological control of blastomycosis and paracoccidioidomycosis. Diagnostic studies should be carried out by competent personnel in specialized laboratories that meet the necessary safety requirements. Thus, awareness about these diseases of as many experts as possible, guarantees the successful implementation of strategies for diagnostics and treatment

Field theoretic calculation of the surface tension for a model electrolyte system

We carry out the calculation of the surface tension for a model electrolyte to first order in a cumulant expansion about a free field theory equivalent to the Debye-H\"uckel approximation. In contrast with previous calculations, the surface tension is calculated directly without recourse to integrating thermodynamic relations. The system considered is a monovalent electrolyte with a region at the interface, of width h, from which the ionic species are excluded. In the case where the external dielectric constant epsilon_0 is smaller than the electrolyte solution's dielectric constant epsilon we show that the calculation at this order can be fully regularized. In the case where h is taken to be zero the Onsager-Samaras limiting law for the excess surface tension of dilute electrolyte solutions is recovered, with corrections coming from a non-zero value of epsilon_0/epsilon.Comment: LaTeX, 14 pages, 3 figures, 1 tabl

Development of brand-communications to promote real estate market companies

Recently the competition in the real estate market has significantly increased. Therefore, the application of brand-communication strategies makes it possible to create a unique set of elements and other components of a brand considering the consumer's demands and the quality and efficiency of the company's operations. The proficiency in the development of brand-communication strategies and their most optimal implementation in a company's operations will make the developer's brand stand out compared to the competition and help establish a relationship of trust with loyal consumers and the mass media

Modulation of the pHLIP Transmembrane Helix Insertion Pathway

The membrane-associated folding/unfolding of pH (low) insertion peptide (pHLIP) provides an opportunity to study how sequence variations influence the kinetics and pathway of peptide insertion into bilayers. Here, we present the results of steady-state and kinetics investigations of several pHLIP variants with different numbers of charged residues, with attached polar cargoes at the peptide\u27s membrane-inserting end, and with three single-Trp variants placed at the beginning, middle, and end of the transmembrane helix. Each pHLIP variant exhibits a pH-dependent interaction with a lipid bilayer. Although the number of protonatable residues at the inserting end does not affect the ultimate formation of helical structure across a membrane, it correlates with the time for peptide insertion, the number of intermediate states on the folding pathway, and the rates of unfolding and exit. The presence of polar cargoes at the peptide\u27s inserting end leads to the appearance of intermediate states on the insertion pathway. Cargo polarity correlates with a decrease of the insertion rate. We conclude that the existence of intermediate states on the folding and unfolding pathways is not mandatory and, in the simple case of a polypeptide with a noncharged and nonpolar inserting end, the folding and unfolding appears as an all-or-none transition. We propose a model for membrane-associated insertion/folding and exit/unfolding and discuss the importance of these observations for the design of new delivery agents for direct translocation of polar therapeutic and diagnostic cargo molecules across cellular membranes

Определение геометрических размеров микрообектов с помощью телевизионных измерительных систем

В статті проведено аналіз напрямів досліджень, спрямованих на підвищення точності вимірювання геометричних параметрів за допомогою телевізійної інформаційно-вимірювальної системи (ТІВС). Для підвищення точності вимірювання за допомогою ТІВС запропоновано використовувати матрицю корекції при різних значеннях освітленості в робочому діапазоні ТІВС. Обґрунтовано підхід до формування вимірювального сигналу, який також дозволить зменшити похибку вимірювання геометричних параметрів об’єкту.Today the development of fundamentally new materials and products requires adequate means of investigation and control of their structural state. Today along with traditional means microscopy rapidly evolving television computerized tools that ensure the formation, processing and subsequent quantitative analysis of a wide range of characteristics of different objects. The article analyzed the directions of research aimed at increasing of the accuracy of measurement of geometric parameters using television information-measuring system (TIMS). To improve the accuracy of measurement by TIMS proposed to use a matrix correction for different values of illumination, in range TIMS. And reasoned approach to forming measuring signal, which will reduce the measurement error of the geometric parameters of the object also.В современном мире разработка принципиально новых материалов и изделий требует создания адекватных средств исследования и контроля их структурного состояния. Уже сегодня одновременно с традиционными средствами микроскопии быстро развиваются телевизионные компьютеризированные средства, которые обеспечивают формирование, обработку и последующий количественный анализ широкого спектра характеристик различных объектов. В статье проведен анализ направлений исследований, направленных на повышение точности измерения геометрических параметров с помощью телевизионной информационно-измерительной системы (ТИИС). Для повышения точности измерения с помощью ТИИС предложено использовать матрицу коррекции при различных значениях освещенности в рабочем диапазоне ТИИС. И обоснован подход к формированию измерительного сигнала, который позволяет уменьшить погрешность измерения геометрических параметров объекта

Molecular Diagnostics of Histoplasmosis

Histoplasmosis is a systemic fungal disease that occurs worldwide. The highest incidence of the disease is reported on the American continent. It also occurs in China, India, South-Eastern Asia, Africa, Australia and Europe. Clinical syndromes of histoplasmosis are not specific and in most cases immunocompetent individuals are asymptomatic or present mild influenza-like disease. Immunocompromised patients especially individuals with AIDS, can develop a severe and fatal disease due to fungal dissemination to many organs. Etiological agent of histoplasmosis is the dimorphic fungus Histoplasma capsulatum, which inhabits the soils contaminated with bird or bat droppings. Three biological varieties are considered for this fungus: H. capsulatum var. capsulatum, H. capsulatum var. duboissii and H. capsulatum var. farciminosum. Genetic differences are observed among H. capsulatum strains from diverse regions of the world. The main molecular methodologies for genetic typing of fungi are based on DNA fingerprinting. They have been an important instrument to identify possible sources of infection in outbreaks of histoplasmosis. Genetic profiles of H. capsulatum, isolated from bats and humans, helped to understand the distribution of the disease in certain endemic regions. The con-ventional diagnosis of histoplasmosis is performed by means of cultural and microscopic examination of samples from the respiratory tract and biologic fluids. However, these techniques yield positive results in only 50 % of cases. In the last two decades, approaches for the detecting of H. capsulatum in clinical samples, using different molecular targets, based on PCR assay have been developed. Their use can shorten the time span of analysis for diagnosis confirmation. Molecular methods have high specificity and sensitivity and reduce the risk of infection for the laboratory personnel. In this study we reviewed the recently published data on the use of main molecular methods for diagnosis of histoplasmosis

Continuous selections of multivalued mappings

This survey covers in our opinion the most important results in the theory of continuous selections of multivalued mappings (approximately) from 2002 through 2012. It extends and continues our previous such survey which appeared in Recent Progress in General Topology, II, which was published in 2002. In comparison, our present survey considers more restricted and specific areas of mathematics. Note that we do not consider the theory of selectors (i.e. continuous choices of elements from subsets of topological spaces) since this topics is covered by another survey in this volume