A multiobjective evolutionary algorithm for optimizing spatial contiguity in reserve network design

Landscape fragmentation is a well-recognized threat to the long-term survivability of many plant and animal species. As a complex concept, fragmentation has multiple spatial and functional components, of which spatial contiguity is of great importance. A contiguous landscape provides physical condition and increases the opportunities for species dispersal and migration. However, in real planning situations, contiguity is either too expensive to achieve or impractical because of barriers of urban landscapes. As such, the traditional yes/no function of contiguity has been extended into a notion of relative contiguity which has the value range between zero and one. Relative contiguity measures levels of interconnectivity of landscapes based on graph theory and spatial interaction. It takes into account both inner-reserve relationship (i.e. reserve sizes) and inter-reserve spatial proximity. This paper presents a multiobjective evolutionary algorithm approach to maximizing relative contiguity in reserve network design. This approach obtains solutions that maximize the measure of relative contiguity, minimize the total acquisition area, and satisfy constraints on the coverage of individual species. Application results show the developed algorithm has significant advantages in optimizing relative contiguity and generating a variety of alternative solutions.     

Venus: A Map of Its Brightness Temperature

The 200-inch Hale telescope has been used to make high-resolution maps of the brightness temperature of Venus at wavelengths 8 to 14 microns. Resolution of about 1/30 of the disk reveals a general symmetry about the plane of the orbit, no daynight temperature effects, and a transient temperature anomaly in the southern hemisphere.     

Using an age-structured model to simulate the recovery of the Australian pilchard (Sardinops sagax) population following epidemic mass mortality

An age-structured model of the Australian pilchard’s population has been adapted to simulate recovery from the mass mortality suffered during the herpesvirus epidemics of 1995 and 1998/1999. The model generates a vigorous recovery even when levels of mortality are very high, which accords with observations. In spite of this strong recovery, the model indicates that stock is sensitive to increased fishing pressure. Healthy stocks of juvenile pilchards play a key role in the vigorous post-epidemic recovery.     

Bat predation and the evolution of frog vocalizations in the neotropics

Bat predation has probably had an important influence on the evolution of frog vocalizations in the Neotropics. The rate at which fringe-lipped bats capture frogs is significantly higher when the frogs are calling. These bats respond to a wide variety of calls from edible frogs, and, when simultaneously presented with a choice, choose the recorded call of a palatable species over that of a poisonous species and the call of a small species over that of one too large to capture. Thus the selective advantages of loud, rapid mating calls in anurans are balanced by an increased risk of predation.     

Strategies for the Development of Conotoxins as New Therapeutic Leads

Peptide toxins typically bind to their target ion channels or receptors with high potency and selectivity, making them attractive leads for therapeutic development. In some cases the native peptide as it is found in the venom from which it originates can be used directly, but in many instances it is desirable to truncate and/or stabilize the peptide to improve its therapeutic properties. A complementary strategy is to display the key residues that make up the pharmacophore of the peptide toxin on a non-peptidic scaffold, thereby creating a peptidomimetic. This review exemplifies these approaches with peptide toxins from marine organisms, with a particular focus on conotoxins.