Sommerville [8] and Davies [2] classified the spherical triangles that can tile the sphere in an edge-to-edge fashion. Relaxing this condition yields other triangles, which tile the sphere but have some tiles intersecting in partial edges. This paper shows that no right triangles in a certain subfamily can tile the sphere, although multilayered tilings are possible.

Herein we demonstrate that flexible DNA architectures with larger cavities can be efficiently constructed by first assembling a relatively more rigid DNA tile architecture and subsequently subtracting a center tile through fuel strand displacement; such structures are otherwise difficult to obtain if the center tile is missing in the beginning, proving a new strategy for DNA self-assembly.

This report was written by Dr. Donald Fraser of the Department of Paediatrics, Universit!/ of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada, in consultation with tile Conirnittee Ofl Nutrition of the American Academy of Pediatrics. The /)OSltiOhb taken on the issue examined reflects the current opinion of tile Committee and i)rovi(les tile .ccie iti/ic background for the ...

An aperiodic tile set is a finite set of tiles which can tile the plane (i.e. cover it without overlap), but not in a periodic way (i.e., no tiling is invariant by a translation). To prove the undecidability of the the Domino problem, Robert Berger constructed in 1966 the first aperiodic tile set [1]. His proof was simplified in 1971 by Rafael Robinson, who introduced a six-tile set and proved ...

background: manual handling, lifting, or carrying of material is responsible for non-fatal injuries among employees in industries. it is the second most prevalent reported risk factor in workplaces that can lead to potential manual handling accidents and longer-term musculoskeletal disorders (msds). the aim of this study was the evaluation of manual material handling using the american national...