Influence of timing of sexual debut and first marriage on sexual behaviour in later life: findings from four survey rounds in the Kisesa cohort in northern Tanzania

OBJECTIVES: To evaluate quality of sexual debut and first marriage data, measure trends and study the association of risky sexual behaviour in youth with adult risk behaviour. METHODS: Reports on age at first sex (AFS) and age at first marriage (AFM) from the Kisesa cohort study, 1994-2004, were evaluated for consistency and used to describe trends in median age-at-event and time spent single but sexually active in different birth cohorts. The association of these variables with marital stability and numbers of partners at later ages was explored using statistical regression techniques. RESULTS: AFS and AFM were inconsistently reported by 32% and 33% of respondents, respectively, but there was no general tendency to report lower or higher ages at a later report date. In 10-year birth cohorts born between 1950-9 and 1980-9, male median AFS declined from 18.1 to 17.0 years and female median AFM rose from 16.2 to 16.6 years. Young people of both sexes currently spend longer sexually active but unmarried than previously. Early marriage is statistically associated with remarriage and polygamy; longer time between sexual debut and marriage is associated with higher numbers of partners at later stages of life. CONCLUSION: Inconsistent reporting of age-at-event introduces noise but does not bias estimates of population level indicators. Lengthening time spent single and sexually active suggests that men and women entering first marriage will have been exposed to increased numbers of non-marital partners. Successful youth interventions may also influence adult behaviour

Estimation of age at death: examination of variation in cortical bone histology within the human clavicle

Background: Continuously, numerous human remains of unknown identity are revealed all over the world. One of the elements of the identification process may be a proper assessment of a histological section of bone fragments in order to answer questions related to the age of the subject. The aim of the study was to define an optimum bone fragment to obtain samples for histological examination. Materials and methods: The study material consisted of fragments of shafts of left clavicles taken from 39 males and 25 females (aged 22–86). The clavicles came from autopsies conducted between 2005 and 2011 at the Department of Forensic Medicine of Poznan and the Bialystok Medical University. The following were taken into account while estimating the age of the bone remains: clavicle length (CL), clavicle width (CW), clavicle thickness (CT), number of osteons in the field of vision (ON), number of osteons with the Haversian canal of more than 70 μm (HC > 70 μm), average diameter of the Haversian canals (avg. ØHC), area occupied by interstitial lamellae (ILA %), area occupied by osteons (OA %), area occupied by fragments-remnants of osteons remain as irregular arcs of lamellar fragments (OFA %), average thickness of outer circumferential lamellae (avg. OCL, μm), the relation of osteons with the Haversian canal of more than 70 μm in diameter to the total number of osteons (HC > 70 μm, %), at p < 0.00001. The age of the bone remains was estimated using univariate linear regression function. Results: It was determined that the best place for sampling the osseous tissue for the analysis was the shaft of the clavicle. It was stated than the number of osteons with a large diameter increased with age. The relation of osteons with the Haversian canal of more than 70 μm in diameter to the total number of osteons (HC > 70 μm, %). The level of statistical significant was p < 0.00001. All analysed microscopic features of the osseous tissue showed significant statistical changes occurring with age. Conclusions: The exact method for preparing osseous tissue for a microscopic analysis to determine the age of the remains is the preparation of histological sections, as the structure of the osseous tissue does not change while processing the material and the time of preparations is relatively short (7–8 days). The best predictors of age with the use of the function of univariate linear regression were: the diameter of Haversian canal, the number of osteons with Haversian canal of more than 70 μm in diameter, the relation of osteons with Haversian canal bigger than 70 μm in diameter to the total number of osteons as well as fragments of secondary osteons

Fractional-order operators: Boundary problems, heat equations

The first half of this work gives a survey of the fractional Laplacian (and related operators), its restricted Dirichlet realization on a bounded domain, and its nonhomogeneous local boundary conditions, as treated by pseudodifferential methods. The second half takes up the associated heat equation with homogeneous Dirichlet condition. Here we recall recently shown sharp results on interior regularity and on $L_p$-estimates up to the boundary, as well as recent H\"older estimates. This is supplied with new higher regularity estimates in $L_2$-spaces using a technique of Lions and Magenes, and higher $L_p$-regularity estimates (with arbitrarily high H\"older estimates in the time-parameter) based on a general result of Amann. Moreover, it is shown that an improvement to spatial $C^\infty$-regularity at the boundary is not in general possible.Comment: 29 pages, updated version, to appear in a Springer Proceedings in Mathematics and Statistics: "New Perspectives in Mathematical Analysis - Plenary Lectures, ISAAC 2017, Vaxjo Sweden

Uwagi na temat historii popularyzacji rektyfikacji okręgu Adama Kochańskiego (1631-1700)

The subject of study in this article is history of popularization of graphic notation of rectification of semicircle by Adam Kochański and changes introduced in this notation in following scientific publications. The author’s aim is to show in which moment the original notation was replaced with the one that was commonly used in publications in XX c.Przedmiotem opracowania w artykule są dzieje popularyzacji rektyfikacji Adama Kochańskiego oraz zmian wprowadzanych w jej zapisie graficznym w kolejnych publikacjach naukowych. Celem, jaki stawia sobie autorka jest próba ustalenia, w którym momencie nastąpiło przekształcenie zapisu oryginalnego na stosowany w publikacjach z XX wieku

Leona Marka Suzina „Wprowadzenie kompozycji i podziałów na powierzchnie krzywe”

The problem of constructing a straight line intersecting four given lines skew to each other is presented in Monge’s projections. The solution consists in choosing an adequate system of projection planes and applying the Steiner’s construction of common lines of two projective pencils of lines.W popularnym podręczniku do nauki perspektywy „Perspektywa wykresowa dla architektów” Leon Marek Suzin prowadzi obszerny wykład o perspektywie i jej zastosowaniach. W jednym z rozdziałów książki opisany jest proces przygotowania wykresu perspektywicznego dla wprowadzenia kompozycji malarskiej na sklepienia kolebkowe i kopuły, które autor nazywa powierzchniami krzywymi. Zarówno tekst jak i rysunki w tym rozdziale budzą wątpliwości, którymi autorka chciała podzielić się z Czytelnikami. W artykule omówione zostały tylko zagadnienia związane z konstruowaniem perspektyw na sklepieniach kolebkowych

Klasyfikacja kształtów dachów o połaciach płaskich

In many on traditional engineering we can find a lot of different, incomplete and inconsequent naming connected with roofs and their shapes. In this article there is presented an idea of classification of roofs connected with what the author of this article finds to be their basic features, that is number of surface slopes and their complexity.W wielu pozycjach literaturowych na temat tradycyjnego budownictwa znajdujemy różnorodne, niekompletne i niekonsekwentne nazewnictwo dotyczące dachów, w tym ich odwołującą się do podstawowych, zdaniem autorki, ich cech, tj. liczby spadków połaci dachowych i form złożoności

Restytucja punto stabile z kościoła pw. Podwyższenia Krzyża Świetego w Brzegu

Researches of illusionary and architectural paintings carried out by the author, showed that in none of sacral interiors in Poland a characteristic mark of observer’s stand called punto stabile has been preserved. In the article punto stabile restitution carried out on the basis of archival photography has been described.Prowadzone przez autorkę badania malowideł iluzjonistyczno-architektonicznych wykazały, że w żadnym z wnętrz sakralnych w Polsce nie zachowało się charakterystyczne oznaczenie stanowiska obserwatora nazywane punto stabile. W artykule opisano restytucję punto stabile przeprowadzoną na podstawie archiwalnej fotografii

Rysunki Friedricha Bernharda Wernhera (1690-1776) a geometria. Częsć 2

Friedrich Bernhard Wernher (Werner), a mapmaker and a drawer of urban landscapes born in Silesia, indicated in the titles of his drawings that he made use of geometrical methods of graphical projection, such as perspective. The article examines selected drawings representative of Wernher's “perspective drawings".Urodzony na Śląsku rysownik map i widoków architektury Friedrich Bernhard Wernher (Werner) (1690-1776) posługiwał się w swoich rysunkach, jak wynika z tytułów jego rysunków, geometrycznymi metodami rzutowania, między innymi perspektywą. Artykuł poświęcono omówieniu wybranych przypadków rysunków, które są reprezentatywne dla „wernherowskiej perspektywy”