Hipersuperficies de tipo esférico degenerado

In this work, we dene the hypersurfaces of the spherical type degenerated (in short DST-hypersurfaces), these hypersurfaces has the geometric property that the middle spheres pass through the origin of the Euclidean space. We present a representation for these hypersurfaces in the case where the stereographic projection of the Gauss map N is given by the identity application. We characterizethe DST-hypersurfaces through a diferential equation and we give an explicit example of a two-parameter family of DST-hypersurfaces with planar lines of curvature foliated by (n-1)-dimensional spheres. Moreover, we classify the DST-hypersurfaces of rotation.En este artículo, definimos las hipersuperficies de tipo esférico degenerado (en abreviatura DST-hipersuperficies), estas hipersuperficies tienen la propiedad geométrica de que las esferas medias pasan por el origen del espacio Euclidiano. Presentamos una representación para estas hipersuperficies para el caso en que la proyección estereográfica de la aplicación de Gauss N es dada por la aplicación identidad. Caracterizamos las DST-hipersuperficies a través de una ecuación diferencial y damos un ejemplo explícito de una familia a dos parámetros de DST-hipersuperficies con líneas de curvatura planas foliadas por esferas de dimensión (n-1). Además, clasificamos las DST-hipersuperficies de rotación.

Accuracy of age estimation of radiographic methods using developing teeth

Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (±S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895] (boys -0.05 ± 0.81, girls -0.20 ± 0.89, both -0.12 y ± 0.85), Demirjian [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994] overestimated age (boys 0.25 ± 0.84, girls 0.23 ± 0.84, both 0.24 y ± 0.86), while Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko's [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study, Proc. Finn. Dent. Soc. 66 (1970) 103-170] methods under-estimated age (boys -0.87 ± 0.87, girls -1.18 ± 0.96, both -1.02 y ± 0.93; boys -0.56 ± 0.91, girls -0.79 ± 1.11, both -0.67 y ± 1.01, respectively). For individual teeth using Haavikko's method, first premolar and second molar were most accurate; and more accurate than the mean value of all developing teeth. The 95% confidence interval of the mean was least for mean of all developing teeth using Haavikko (age 3-13.99 years), followed by identical values for Demirjian and Willems (sexes combined).</p

Peacebuilding Education and Advocacy in Conflict-Affected Contexts Programme, UNICEF Programme Report 2012-2016

Too many parts of the world are suffering from conflict and its repercussions. Millions of children and young people are at risk of not reaching their full potential. Before more decades of development efforts are undone and future progress is blocked, it is a moral obligation of society to collectively find ways to foster social cohesion among communities, resilience in systems and individuals, and a sense of security in daily lives. The Learning for Peace programme attempted to do just that. This Peacebuilding, Education and Advocacy in Conflict-Affected Contexts (PBEA) Programme Report summarizes processes, results and learning that occurred during the entire course of the PBEA programme--Learning for Peace--from 1 December 2011 through 30 June 2016. It draws extensively on reports produced by the 14 participating UNICEF country offices, five regional offices, a total of nine headquarters sections, units or divisions, and partners engaged in the programme. These documents were systematically coded and analysed for this report. This evidence was supplemented by a review of an extensive body of research produced within and outside the auspices of the programme. Members of the Learning for Peace Programme Management Team, along with other technical advisers and experts at UNICEF headquarters, provided additional insight and analysis. UNICEF hopes that the testimonies of approaches, achievements and challenges documented in this report inform its readers of how education (or social services more broadly) can be harnessed to build peace. [Funding for this programme was provided by the Government of the Netherlands.