2 SI A. Y. Tulchinsky et al.

Let n be an integer and q be a prime power. Then for any 3 ≤ n ≤ q − 1, or n = 2 and q odd, we construct a connected q-regular edgebut not vertextransitive graph of order 2qn+1. This graph is defined via a system of equations over the finite field of q elements. For n = 2 and q = 3, our graph is isomorphic to the Gray graph.

In this paper we study finite, connected, 4-valent graphs X which admit an action of a group G which is transitive on vertices and edges, but not transitive on the arcs of X. Such a graph X is said to be (G, 1 2)-transitive. The group G induces an orientation of the edges of X, and a certain class of cycles of X (called alternating cycles) determined by the group G is identified as having an im...

We introduce the concept of a 2-starter in a groupG of odd order.We prove that any 2-factorization of the complete graph admitting G as a sharply vertex transitive automorphism group is equivalent to a suitable 2-starter in G. Some classes of 2-starters are studied, with special attention given to those leading to solutions of some Oberwolfach or Hamilton–Waterloo problems. © 2005 Elsevier Inc....

A 64-year-old Iranian woman presented with a genital erosive skin lesion that she had noticed from two years ago. On physical examination, a 20 to 25 millimeter purplish lesion was observed on the vulval skin (Figure 1). The indurated lesion showed a small central erosion measuring 3 to 5 mm. Inguinal lymph nodules were not palpable. A skin biopsy specimen was obtained from the eroded les...

In Reply: The comments of Dr Wiwanitkit are well taken. In our article (1), our main concern was to emphasize the big difference between plagiarism of ideas and plagiarism of text, especially in scientific writing, where we believe text is just a transfer medium for ideas, which are the essence of scientific work (2-5). Paraphrasing of a scientific text is not always easy, if possible at all (6...

Background subtraction is a widely used concept to detect moving objects in videos taken from a static camera. In the last two decades several algorithms have been developed for background subtraction and were used in various important applications such as visual surveillance, sports video analysis, motion capture, etc.Various statistical approaches have been proposed to model scene background....