Дослідження впливу фосфатів на біопродуктивність Chlorella vulgaris

Підвищений вміст фосфору у водоймах є основною причиною їхньої евтрофікації. Евтрофікація – процес зростання водної рослинності, який відбувається внаслідок перевищення балансу поживних речовин. Він супроводжується надмірним розвитком водоростей, особливо зелених, синьо-зелених і діатомових, переважанням небажаних видів планктону, порушенням життєдіяльності риб. Продукти метаболізму водоростей дають воді неприємний запах, можуть викликати шкірні алергічні реакції і шлунково-кишкові захворювання у людей і тварин. Після відмирання водорості виділяють у воду поліпептиди, аміак і проміжні продукти білкового розпаду. Це може призводити до підвищення вмісту фенолів, які мають канцерогенні властивості

The Alvarez and Lohmann refractive lenses revisited

15 pages, 10 figures.-- OCIS codes: 080.1510, 080.2740, 330.4460.Alvarez and Lohmann lenses are variable focus optical devices based on lateral shifts of two lenses with cubic-type surfaces. I analyzed the optical performance of these types of lenses computing the first order optical properties (applying wavefront refraction and propagation) without the restriction of the thin lens approximation, and the spot diagram using a ray tracing algorithm. I proposed an analytic and numerical method to select the most optimum coefficients and the specific configuration of these lenses. The results show that Lohmann composite lens is slightly superior to Alvarez one because the overall thickness and optical aberrations are smaller.I benefit from a Spanish Ministry of Science-UPM "Ramón y Cajal" contract.Peer reviewe

Таможенные услуги: сущность, порядок предоставления и проблемы качества

В работе исследуется содержание системы предоставления таможенных услуг в России. Также в работе представлены результаты изучения качества предоставления таможенных услуг таможенными органами и коммерческим сектором и предлагаются пути решения данных проблем.The diploma work is aimed at studying the content of the system of providing customs services in Russia. The diploma work also studies the problem of the quality of services provided by the customs authorities and the commercial sector and suggests the ways of its solving

Математическое моделирование возникновения и распространения лесных пожаров с учетом противопожарных барьеров

С помощью метода математического моделирования изучается процесс распространения верховых лесных пожаров при наличии противопожарных разрывов и заслонов. Математически данная задача сводится к решению уравнений Рейнольдса для турбулентного течения с учетом химических реакций. Для получения дискретного аналога использован метод контрольного объема. С помощью численных расчетов получены распределения полей скорости, температуры, концентраций кислорода, летучих продуктов пиролиза, горения и объемных долей конденсированной фазы, получены контуры распространения верховых лесных пожаров, определена зависимость размеров противопожарных разрывов и заслонов при которых верховой пожар прекращает распространение.Using the method of mathematical modeling, the propagation of high forest fires in the presence of fire breaks and barriers is studied. Mathematically, this problem reduces to solving the Reynolds equations for a turbulent flow, taking into account chemical reactions. To obtain a discrete analog, the control volume method was used. Using numerical calculations, the distributions of the fields of velocity, temperature, oxygen concentrations, volatile pyrolysis products, combustion, and volume fractions of the condensed phase, the propagation contours of upland forest fires were obtained, the dependence of the size of fire breaks and barriers at which the top fire stops propagation was determined

Gender specific quality of life in patients with oral squamous cell carcinomas

<p>Abstract</p> <p>Background</p> <p>The goal of this study was to evaluate the somatic and psychological effects by means of QUALITY OF LIFE (QOL) of surgical treatment of patients with oral squamous cell carcinoma. The factors gender, age, nicotine consumption, and tumour stage were taken into consideration.</p> <p>Methods</p> <p>54 patients after surgical resection of oral squamous cell carcinomas (OSCC) were analysed from 01.09.2005 to 31.05.2008. Inclusion criteria for the study were: age at least 18 years, no indication or treatment of synchronous and metachronous tumours.</p> <p>German translations of the EORTC H&N-35 and EORTC QLQ-C-30 questionnaires, as well as a general socioeconomic patient history were used as measuring instruments. The questionnaires were completed independently by the patients. The answers were translated into scale values for statistical evaluation using appropriate algorithms.</p> <p>Results</p> <p>Analysis of the EORTC-QLQ-C-30 questionnaires demonstrated a tendency of more negative assessment of emotional function among the female participants, and a more negative evaluation of social function among the male participants. Greater tumour sizes showed significantly lower bodily function (p = 0.018). While a smaller tumour size was significantly associated with lower cognitive functioning (p = 0.031). Other cofactors such as age, nicotine consumption, and tumour stage only showed a tendency to influence the quality of sleep and daily life.</p> <p>Conclusions</p> <p>The data obtained within this investigation demonstrated that gender had the most significant power on the subjectively perceived postoperative quality of life. This factor is important e.g. in preoperative decision making regarding immediate microvascular reconstruction after e.g. mandibular resection and therefore QOL assessment should become integral component of the care of patients with OSCC.</p

Access to primary care for socio-economically disadvantaged older people in rural areas: exploring realist theory using structural equation modelling in a linked dataset

Background: Realist approaches seek to answer questions such as ‘how?’, ‘why?’, ‘for whom?’, ‘in what circumstances?’ and ‘to what extent?’ interventions ‘work’ using context-mechanism-outcome (CMO) configurations. Quantitative methods are not well-established in realist approaches, but structural equation modelling (SEM) may be useful to explore CMO configurations. Our aim was to assess the feasibility and appropriateness of SEM to explore CMO configurations and, if appropriate, make recommendations based on our access to primary care research. Our specific objectives were to map variables from two large population datasets to CMO configurations from our realist review looking at access to primary care, generate latent variables where needed, and use SEM to quantitatively test the CMO configurations. Methods: A linked dataset was created by merging individual patient data from the English Longitudinal Study of Ageing and practice data from the GP Patient Survey. Patients registered in rural practices and who were in the highest deprivation tertile were included. Three latent variables were defined using confirmatory factor analysis. SEM was used to explore the nine full CMOs. All models were estimated using robust maximum likelihoods and accounted for clustering at practice level. Ordinal variables were treated as continuous to ensure convergence. Results: We successfully explored our CMO configurations, but analysis was limited because of data availability. Two hundred seventy-six participants were included. We found a statistically significant direct (context to outcome) or indirect effect (context to outcome via mechanism) for two of nine CMOs. The strongest association was between ‘ease of getting through to the surgery’ and ‘being able to get an appointment’ with an indirect mediated effect through convenience (proportion of the indirect effect of the total was 21%). Healthcare experience was not directly associated with getting an appointment, but there was a statistically significant indirect effect through convenience (53% mediated effect). Model fit indices showed adequate fit. Conclusions: SEM allowed quantification of CMO configurations and could complement other qualitative and quantitative techniques in realist evaluations to support inferences about strengths of relationships. Future research exploring CMO configurations with SEM should aim to collect, preferably continuous, primary data