Is sunlight good for our heart?

Humans evolved being exposed for about half of the day to the light of the sun. Nowadays, exposure to sunlight is actively discouraged for fear of skin cancer, and contemporary lifestyles are associated with long hours spent under artificial light indoors. Besides an increasing appreciation for the adverse effects of these life-style-related behavioural changes on our chronobiology, the balance between the beneficial and harmful effects of sunlight on human health is the subject of considerable debate, in both the scientific and popular press, and the latter is of major public health significance. While there is incontrovertible evidence that ultraviolet radiation (UVR) in the form of sunlight is a significant predisposing factor for non-melanoma and melanoma skin cancers in pale skinned people,1 a growing body of data suggest general health benefits brought about by sunlight.2 These are believed to be mediated either by melatonin or vitamin D. Melatonin is produced from serotonin by the pineal gland located in the centre of the brain during periods of darkness, and its release is suppressed as a function of the visible light intensity sensed through ocular photoreceptors. Vitamin D is formed by ultraviolet B (UVB)-mediated photolysis of 7-dehydrocholesterol in the skin. Both melatonin and vitamin D are pleiotropic hormones that exert a multitude of cellular effects by interacting with membrane and nuclear receptors, and receptor-independent actions. People with more heavily pigmented skin require higher doses of UVB to produce adequate amounts of vitamin D, and this may have been an evolutionary driver to the variation of human skin colour with latitude and intensity of solar irradiation. Our degree of exposure to sunlight is easily modified by behavioural factors such as the use of clothing, sunglasses, and sun-blocking creams, and time spent outdoors. Balancing the carcinogenic risks with the requirement for vitamin D has led to advice on moderating sun exposure, while supplementing food with vitamin D. Guidance on such behaviour is part of the public health campaigns in most countries with Caucasian populations. Following these suggestions, we may, however, be missing out on other health benefits provided by natural sunlight that are less obvious and unrelated to the above classical mediators

Features of verbal communication of the Tajik youth in social networks

Within the framework of this article, the author presents materials of empirical research on the features of verbal communication of Tajik youth in social networks. Data of content analysis is given. The author of the article comes to the conclusion that the written speech of the Tajik users of social networks is different. Written speech of Tajik users of networks in their native language is diverse, in Russian it is simple, monotonous

Specific Age-Associated DNA Methylation Changes in Human Dermal Fibroblasts

Epigenetic modifications of cytosine residues in the DNA play a critical role for cellular differentiation and potentially also for aging. In mesenchymal stromal cells (MSC) from human bone marrow we have previously demonstrated age-associated methylation changes at specific CpG-sites of developmental genes. In continuation of this work, we have now isolated human dermal fibroblasts from young (<23 years) and elderly donors (>60 years) for comparison of their DNA methylation profiles using the Infinium HumanMethylation27 assay. In contrast to MSC, fibroblasts could not be induced towards adipogenic, osteogenic and chondrogenic lineage and this is reflected by highly significant differences between the two cell types: 766 CpG sites were hyper-methylated and 752 CpG sites were hypo-methylated in fibroblasts in comparison to MSC. Strikingly, global DNA methylation profiles of fibroblasts from the same dermal region clustered closely together indicating that fibroblasts maintain positional memory even after in vitro culture. 75 CpG sites were more than 15% differentially methylated in fibroblasts upon aging. Very high hyper-methylation was observed in the aged group within the INK4A/ARF/INK4b locus and this was validated by pyrosequencing. Age-associated DNA methylation changes were related in fibroblasts and MSC but they were often regulated in opposite directions between the two cell types. In contrast, long-term culture associated changes were very consistent in fibroblasts and MSC. Epigenetic modifications at specific CpG sites support the notion that aging represents a coordinated developmental mechanism that seems to be regulated in a cell type specific manner

The synthesis of multi-loop control systems for a precision lathe by numerical method

The article deals with the problem of the synthesis of multi-loop control system. Modern methods of the synthesis of multi-loop control systems do not provide the control with prescribed accuracy. This paper combines real interpolation method and numerical method

Replicative senescence of mesenchymal stem cells causes DNA-methylation changes which correlate with repressive histone marks

Cells in culture undergo replicative senescence. In this study, we analyzed functional, genetic and epigenetic sequels of long-term culture in human mesenchymal stem cells (MSC). Already within early passages the fibroblastoid colonyforming unit (CFU-f) frequency and the differentiation potential of MSC declined significantly. Relevant chromosomal aberrations were not detected by karyotyping and SNP-microarrays. Subsequently, we have compared DNA-methylation profiles with the Infinium HumanMethylation27 Bead Array and the profiles differed markedly in MSC derived from adipose tissue and bone marrow. Notably, all MSC revealed highly consistent senescence-associated modifications at specific CpG sites. These DNA-methylation changes correlated with histone marks of previously published data sets, such as trimethylation of H3K9, H3K27 and EZH2 targets. Taken together, culture expansion of MSC has profound functional implications - these are hardly reflected by genomic instability but they are associated with highly reproducible DNA-methylation changes which correlate with repressive histone marks. Therefore replicative senescence seems to be epigenetically controlled

Особенности формирования прибыли строительных организаций на примере «ООО Рекон Строй»

Объектом исследования является процесс управления прибылью предприятия. Цель работы – разработка мероприятий по повышению прибыли предприятия на основе совершенствования процесса управления прибылью. В процессе исследования проводились: оценка влияния факторов на уровень прибыли ООО "Рекон Строй"; совершенствование процесса формирования прибыли ООО "Рекон Строй". В результате исследования предложены направления совершенствования процесса формирования прибыли ООО "Рекон Строй". Основные конструктивные, технологические и технико-эксплуатационные характеристикиThe object of study is the process of profit administration in a company. The work purpose – development of measures to improve the profits of the enterprise based on the improvement of the process of profit management. In the process studies were conducted: assessment of the impact of factors on the profit level of OOO "Rekon Stroy"; improving the process of profit formation of OOO "Rekon Stroy". The study suggested ways of improving the process of profit formation of OOO "Rekon Stroy". The basic constructive, technological and technical-operational characteristic

ПРО ОДИН З АСПЕКТІВ КОМПЛЕКСНОГО ВИРІШЕННЯ ПИТАННЯ БУДІВНИЦТВА КАНАЛУ АЗОВСЬКЕ МОРЕ – МОЛОЧНИЙ ЛИМАН

Молочний лиман – один з найбільш цінних водно-болотних угідь Приа-зов’я, який увійшов до Міжнародного кадастру Рамсарських територій. Згідно з фізико-географічним районуванням України, Молочний лиман відноситься до Присивасько-Приазовської степової області Причорноморської південно-степової провінції. Адміністративно ця акваторія знаходиться в Запорізькій об-ласті і розташована на територіях Якимівського, Приазовського та Мелітополь-ського районів. Довжина лиману складає 32 км, максимальна ширина 8 км, гли-бина до 3 м, площа 170 км2. Від Азовського моря Лиман відділений косою Пе-ресип зі штучно створеною протокою (промоїною). Останнім часом, з`єднувальний канал Молочного лиману практично не функціонує