THE history of goitre in Central and West Africa is obscure. Greenwald1 thinks that for many regions 'such as Nigeria, most of the Congo, and parts of East Africa the evidence is equally convincing that goiter is of recent occurrence. . .'. This may not be so. It may have been common from an early period even though references to it are few. In the far north, in the Rif country of Morocco, goit...

This paper describes the results of our experiments with gluing together partial hyperbolic paraboloids, or hypars. We make a paper model of each hypar by folding a polygonal piece of paper along concentric polygons in an alternating fashion. Gluing several hypars together along edges, we obtain a beautiful collection of closed, curved surfaces which we call hyparhedra. Our main examples are gi...

Powerful computers together with sophisticated programs for geometric modeling and graphical rendering allow to create interesting and artistic displays in novel ways. Computers can playa role in the definition of new shapes, e.g., through the use of abstract geometrical generator functions, as well as in the realization of these shapes, e.g., by drawing exact blueprints or by milling parts. On...

Mathematical string sculptures constitute an extremely beautiful realm of mathematical crafts. This snapshot begins with a description of a marvelous (and no longer manufactured) toy called Space Spider, which provided a framework with which children could experiment with string sculptures. Using a computer-controlled laser cutter to create frames for weaving string, not only can we recreate th...

inscriptions in calligraphy, hard stone carving and rock reliefs have a long tradition in iranian art. although from the pre-islamic times many important samples of three dimensional sculptures have been found in iran, during the islamic era, because of the religious edicts and beliefs, that they had the sculpting prohibited, the art of sculpture couldn’t be developed in the way of pre-islamic ...

background: in the history there are long backgrounds to coexistence of human and domesticated animal. counter effect of more than 150 common diseases threat the human and domesticated health. due to climate condition of mazandaran, in the north of iran, the objective of the present study is to evaluate health conditions of the industrial animal husbandries (iah) during 2000-2001 . methods: thi...