This paper presents a new model for VLSI routing in the presence of obstacles, that transforms any routing instance from a geometric problem into a graph problem. It is the first model that allows computation of optimal obstacle-avoiding rectilinear Steiner trees in time corresponding to the instance size (the number of terminals and obstacle border segments) rather than the size of the routing...

‎The first variable Zagreb index of graph $G$ is defined as‎ ‎begin{eqnarray*}‎ ‎M_{1,lambda}(G)=sum_{vin V(G)}d(v)^{2lambda}‎, ‎end{eqnarray*}‎ ‎where $lambda$ is a real number and $d(v)$ is the degree of‎ ‎vertex $v$‎. ‎In this paper‎, ‎some upper and lower bounds for the distribution function and expected value of this index in random increasing trees (rec...

SOUTHBEND, Ind. [AP] Practic­ ing the virtue of hum ility, the Rev. Theodore M. Hesburgh submits his resignation as president of the University of Notre Dame once a year. But it hasn’t been accepted yet and isn’t likely to be accepted soon. Now in his 25th year at the helm of the nation’s best-known Catholic university, Hesburgh qualifies as dean of university presidents across the country. “ T...

The montane forests of Mount Kilimanjaro in Tanzania have been subjected to a long history of selective logging. However, since 1984 logging of indigenous trees is prohibited. Today, these forests allow us to evaluate the long-term effects of selective logging. We mapped the height and diameter at breast height (DBH) of all trees >10 cm DBH on 10 sites of 0.25 ha. Five sites represent non-logge...

When we reflect on the emergence of online education and e-learning as the leading contender to confront the traditions of face-to-face teaching and learning, it is not only a case of better understanding the characteristics of online environments, but also timely to assess the relevance of theories and frameworks informing the design and implementation of those environments. Over the past twen...

Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new contine...

HSIANG, T., and EDMONDS, R. L. 1989. Physiological specialization of Heterobasidion annosum on conifer hosts. Can. J. Bot. 67: 2396-2400. Eight conifer hosts belonging to five conifer species were inoculated in vitro with conidial suspensions of eight isolates of Heterobasidion annosum from Washington and Califomia. The conifer trees were represented in inoculation tests by 1 cm diameter branch...