Factors affecting the establishment and dispersal of nymphs of Pristhesancus plagipennis Walker (Hemiptera : Reduviidae) when released onto soybean, cotton and sunflower crops

A problem with augmenting predatory bugs through mass release is the logistical difficulty of delivering nymphs onto the foliage of field crops. In this paper we examine postrelease establishment and dispersal of the nymphs of the predatory bug Pristhesancus plagipennis on soybean, cotton and sunflower in an effort to devise an appropriate strategy for field release. The effects of predator stadia and release rates on field establishment and within-crop-canopy dispersal after hand release were recorded in soybean, cotton and sunflower. Field establishment improved with the release of more-developed nymphs, with third instars providing the most appropriate compromise between field hardiness and rearing cost. Increased nymphal density at the point of release had little effect on nymphal dispersal throughout the crop canopy. The patterns of nymphal dispersal observed on the three crops suggest that crop-canopy architecture may have an effect on the ability of nymphs to spread out postrelease, as nymphs dispersed poorly in cotton and sunflower compared to soybean. To overcome poor dispersal of nymphs after release, a mechanical release method, where nymphs were mixed with vermiculite and delivered onto a target crop through a spinning disk fertiliser spreader, was tested, and provided similar nymph establishment rates and dispersal patterns as releasing nymphs individually by hand. The implications of nymph dispersal and field hardiness in regard to inundative field release techniques are discussed.

Spatial distribution of benthic microalgae on coral reefs determined by remote sensing

Understanding the ecological role of benthic microalgae, a highly productive component of coral reef ecosystems, requires information on their spatial distribution. The spatial extent of benthic microalgae on Heron Reef (southern Great Barrier Reef, Australia) was mapped using data from the Landsat 5 Thematic Mapper sensor. integrated with field measurements of sediment chlorophyll concentration and reflectance. Field-measured sediment chlorophyll concentrations. 2 ranging from 23-1.153 mg chl a m(2), were classified into low, medium, and high concentration classes (1-170, 171-290, and > 291 mg chl a m(-2)) using a K-means clustering algorithm. The mapping process assumed that areas in the Thematic Mapper image exhibiting similar reflectance levels in red and blue bands would correspond to areas of similar chlorophyll a levels. Regions of homogenous reflectance values corresponding to low, medium, and high chlorophyll levels were identified over the reef sediment zone by applying a standard image classification algorithm to the Thematic Mapper image. The resulting distribution map revealed large-scale ( > 1 km 2) patterns in chlorophyll a levels throughout the sediment zone of Heron Reef. Reef-wide estimates of chlorophyll a distribution indicate that benthic Microalgae may constitute up to 20% of the total benthic chlorophyll a at Heron Reef. and thus contribute significantly to total primary productivity on the reef.

A monolithic smoothing-gap algorithm for contact-impact based on the signed distance function

A new algorithm has been developed for smoothing the surfaces in finite element formulations of contact-impact. A key feature of this method is that the smoothing is done implicitly by constructing smooth signed distance functions for the bodies. These functions are then employed for the computation of the gap and other variables needed for implementation of contact-impact. The smoothed signed distance functions are constructed by a moving least-squares approximation with a polynomial basis. Results show that when nodes are placed on a surface, the surface can be reproduced with an error of about one per cent or less with either a quadratic or a linear basis. With a quadratic basis, the method exactly reproduces a circle or a sphere even for coarse meshes. Results are presented for contact problems involving the contact of circular bodies. Copyright (C) 2002 John Wiley Sons, Ltd.

The impact of genotyping error on haplotype reconstruction and frequency estimation

The choice of genotyping families vs unrelated individuals is a critical factor in any large-scale linkage disequilibrium (LD) study. The use of unrelated individuals for such studies is promising, but in contrast to family designs, unrelated samples do not facilitate detection of genotyping errors, which have been shown to be of great importance for LD and linkage studies and may be even more important in genotyping collaborations across laboratories. Here we employ some of the most commonly-used analysis methods to examine the relative accuracy of haplotype estimation using families vs unrelateds in the presence of genotyping error. The results suggest that even slight amounts of genotyping error can significantly decrease haplotype frequency and reconstruction accuracy, that the ability to detect such errors in large families is essential when the number/complexity of haplotypes is high (low LD/common alleles). In contrast, in situations of low haplotype complexity (high LD and/or many rare alleles) unrelated individuals offer such a high degree of accuracy that there is little reason for less efficient family designs. Moreover, parent-child trios, which comprise the most popular family design and the most efficient in terms of the number of founder chromosomes per genotype but which contain little information for error detection, offer little or no gain over unrelated samples in nearly all cases, and thus do not seem a useful sampling compromise between unrelated individuals and large families. The implications of these results are discussed in the context of large-scale LD mapping projects such as the proposed genome-wide haplotype map.

Knowledge of the national emergency telephone number and prevalence and characteristics of those trained in CPR in Queensland: baseline information for targeted training interventions

Members of the community contribute to survival from out-of-hospital cardiac arrest by contacting emergency medical services and performing cardiopulmonary resuscitation (CPR) prior to the arrival of an ambulance. In Australia there is a paucity of information of the extent that community members know the emergency telephone number and are trained in CPR. A survey of Queensland adults (n = 4490) was conducted to ascertain current knowledge and training levels and to target CPR training. Although most respondents (88.3%) could state the Australian emergency telephone number correctly, significant age differences were apparent (P < 0.001). One in five respondents aged 60 years and older could not state the emergency number correctly. While just over half the respondents (53.9%) had completed some form of CPR training, only 12.1% had recent training. Older people were more likely to have never had CPR training than young adults. Additional demographic and socio-economic differences were found between those never trained in CPR and those who were. The results emphasise the need to increase CPR training in those aged 40 and over, particularly females, and to increase the awareness of the emergency telephone number amongst older people. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

A subset-oriented algorithm for minimizing the number of steps required for synthesis of cyclic-peptide libraries

Libraries of cyclic peptides are being synthesized using combinatorial chemistry for high throughput screening in the drug discovery process. This paper describes the min_syn_steps.cpp program (available at http://www.imb.uq.edu.au/groups/smythe/tran), which after inputting a list of cyclic peptides to be synthesized, removes cyclic redundant sequences and calculates synthetic strategies which minimize the synthetic steps as well as the reagent requirements. The synthetic steps and reagent requirements could be minimized by finding common subsets within the sequences for block synthesis. Since a brute-force approach to search for optimum synthetic strategies is impractically large, a subset-orientated approach is utilized here to limit the size of the search. (C) 2002 Elsevier Science Ltd. All rights reserved.

Distribution and evolution of the Anopheles punctulatus group (Diptera : Culicidae) in Australia and Papua New Guinea

The members of the Anopheles punctulatus group are major vectors of malaria and Bancroftian filariasis in the southwest Pacific region. The group is comprised of 12 cryptic species that require DNA-based tools for species identification. From 1984 to 1998 surveys were carried out in northern Australia, Papua New Guinea and on islands in the southwest Pacific to determine the distribution of the A. punctulatus group. The results of these surveys have now been completed and have generated distribution data from more than 1500 localities through this region. Within this region several climatic and geographical barriers were identified that restricted species distribution and gene flow between geographic populations. This information was further assessed in light of a molecular phylogeny derived from the ssrDNA (18S). Subsequently, hypotheses have been generated on the evolution and distribution of the group so that future field and laboratory studies may be approached more systematically. This study suggested that the ability for widespread dispersal was found to have appeared independently in species that show niche-specific habitat preference (Anopheles farauti s.s. and A. punctulatus) and conversely in species that showed diversity in their larval habitat (Anopheles farauti 2). Adaptation to the monsoonal climate of northern Australia and southwest Papua New Guinea was found to have appeared independently in A. farauti s.s., A. farauti 2 and Anopheles farauti 3. Shared or synapomorphic characters were identified as saltwater tolerance (A. farauti s.s. and Anopheles farauti 7) and elevational affinities above 1500 m (Anopheles farauti 5, Anopheles farauti 6 and A. farauti 2). (C) 2002 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.

Using siting algorithms in the design of marine reserve networks

Using benthic habitat data from the Florida Keys (USA), we demonstrate how siting algorithms can help identify potential networks of marine reserves that comprehensively represent target habitat types. We applied a flexible optimization tool-simulated annealing-to represent a fixed proportion of different marine habitat types within a geographic area. We investigated the relative influence of spatial information, planning-unit size, detail of habitat classification, and magnitude of the overall conservation goal on the resulting network scenarios. With this method, we were able to identify many adequate reserve systems that met the conservation goals, e.g., representing at least 20% of each conservation target (i.e., habitat type) while fulfilling the overall aim of minimizing the system area and perimeter. One of the most useful types of information provided by this siting algorithm comes from an irreplaceability analysis, which is a count of the number of, times unique planning units were included in reserve system scenarios. This analysis indicated that many different combinations of sites produced networks that met the conservation goals. While individual 1-km(2) areas were fairly interchangeable, the irreplaceability analysis highlighted larger areas within the planning region that were chosen consistently to meet the goals incorporated into the algorithm. Additionally, we found that reserve systems designed with a high degree of spatial clustering tended to have considerably less perimeter and larger overall areas in reserve-a configuration that may be preferable particularly for sociopolitical reasons. This exercise illustrates the value of using the simulated annealing algorithm to help site marine reserves: the approach makes efficient use of;available resources, can be used interactively by conservation decision makers, and offers biologically suitable alternative networks from which an effective system of marine reserves can be crafted.