Reinvasion of a Riparian Forest Community by an Animal-dispersed Tree Weed Following Control Measures

Patterns of seed dispersal and the effects of mulching upon Celtis sinensis Pers. seedling establishment were investigated following the removal of this tree weed from a riparian forest community. At the commencement of the study there was virtually no representation of C. sinensis in the soil seed bank. However, subsequent rates of seed immigration were high since mature individuals of C. sinensis remained on the boundary of the site. Fruit bats (Pteropus spp.) were the principal dispersal vectors. Seed rain density of C. sinensis was best fitted by an inverse power distribution, with seed densities in excess of 20 m⁻² detected at 70 m from the seed source. Extrapolation from this relationship suggested that a site would have to be more than 350 m from a seed source to reduce the C. sinensis seed rain to less than 1 m⁻². More than 98% of the seed rain occurred below the canopies of the native tree species that remained following the removal of C. sinensis. For these trees, subarboreal C. sinensis seed distributions were not homogeneous, with peak seed densities occurring at different distances from tree trunks in each of the two years that seed distributions were assessed. Mulching with compacted sugar cane trash, corresponding to litter loadings of 6–12 kg m⁻², was imposed early in the study, some weeks before the C. sinensis seed rain commenced. These treatments had no measurable effect upon C. sinensis germination, but substantially reduced seedling survival and had variable effects upon the early growth of seedlings. The potential roles of seed limitation vs establishment limitation are discussed in relation to the management of animal-dispersed invasive species. It is argued that an understanding of the likely levels and patterns of invasion is essential for the formulation of management strategies that can effectively reduce the invasion and impacts of these plants. This revised version was published online in July 2006 with corrections to the Cover Date.     

Extended evaluation of previously reported twins with a ring 14 chromosome.

Extended studies of recently described twins with ring(14) are presented. A single C band and nucleolar organizer region were observed in the r(14). Gene marker evaluations are compatible with monozygosity of the twins.     

An ontology for a Robot Scientist

MOTIVATION: A Robot Scientist is a physically implemented robotic system that can automatically carry out cycles of scientific experimentation. We are commissioning a new Robot Scientist designed to investigate gene function in S. cerevisiae. This Robot Scientist will be capable of initiating >1,000 experiments, and making >200,000 observations a day. Robot Scientists provide a unique test bed for the development of methodologies for the curation and annotation of scientific experiments: because the experiments are conceived and executed automatically by computer, it is possible to completely capture and digitally curate all aspects of the scientific process. This new ability brings with it significant technical challenges. To meet these we apply an ontology driven approach to the representation of all the Robot Scientist's data and metadata. RESULTS: We demonstrate the utility of developing an ontology for our new Robot Scientist. This ontology is based on a general ontology of experiments. The ontology aids the curation and annotating of the experimental data and metadata, and the equipment metadata, and supports the design of database systems to hold the data and metadata. AVAILABILITY: EXPO in XML and OWL formats is at: http://sourceforge.net/projects/expo/. All materials about the Robot Scientist project are available at: http://www.aber.ac.uk/compsci/Research/bio/robotsci/.     

Complement C3 Drives Autophagy-Dependent Restriction of Cyto-invasive Bacteria

1. Download high-res image (169KB)
2. Download full-size image

     

Development of a 1.4-Mb BAC/PAC contig and physical map within the critical region for complete X-linked congenital stationary night blindness in Xp11.4

A physical map internal to the markers DXS1368 and DXS228 was developed for the p11.4 region of the human X chromosome. Twenty-four BACs and 10 PACs with an average insert size of 149 kb were aligned to form a contig across an estimated 1.4 Mb of DNA. This contig, which has on average fourfold clone coverage, was assembled by STS and EST content analysis using 46 markers, including 8 ESTs, two retinally expressed genes, and 22 new STSs developed from BAC- and PAC-derived DNA sequence. The average intermarker distance was 30 kb. This physical map provides resources for high-resolution mapping as well as suitable clones for large-scale sequencing efforts in Xp11.4, a region known to contain the gene for complete X-linked congenital stationary night blindness.     

Application of the synthetic method to other amines.

Taurine and 2-aminoethylphosphonic acid were synthesized by the method of the main paper [Geoghegan & Dixon (1989) Biochem. J. 260, 295-296], i.e. by treating the corresponding halo compound with 2-aminoethanol and then with periodate.     

Can recreational hunting contribute to pest mammal control on public land in Australia?

1. Natural resource management agencies in many countries take advantage of recreational hunting to manage the impacts or abundance of mammal populations that damage biodiversity or environmental, economic, or social values. In Australia, public lands are increasingly being made available for recreational hunters to pursue introduced mammals that can cause substantial damage to important resources. There is fervent debate over the role that recreational hunting might play in controlling introduced mammals in Australia, and scant evidence to build management strategies upon.
2. In this review, we combine information from Australia and elsewhere in a systematic examination of the potential for recreational hunting to contribute to the control of introduced mammals on public lands in Australia. We examine the traits of introduced mammal species and populations, geographical settings, hunters, and management agencies to propose situations where hunting might be most useful, and suggest how current practice could be improved.
3. We find there is insufficient evidence to support or disprove arguments that contemporary recreational hunting programs are effective at controlling introduced mammal populations on public lands. Moreover, current hunting management programs offer little potential for clarifying the situation or optimizing the value of recreational hunting as a pest animal control tool.
4. To resolve this problem, we outline a framework of competing models and diagnostic criteria for assessing the effects of recreational hunting on introduced mammal populations. We contend that hunting will continue to be an under‐utilized and over‐politicized resource until management strategy is informed by transparent monitoring based on rational strategic objectives that provide mutual benefits to hunters and public resource managers.

     

Mental retardation associated with "balanced" chromosome rearrangements.

Balanced chromosome rearrangements were found in seven of 455 retarded children vs. four of 1,679 nonretarded, psychiatric children (P less than .05). The combined incidence of non-Robertsonian balanced rearrangements from this and reported surveys of the mentally retarded was five times greater than that from newborn surveys, whereas Robertsonian translocations were not increased among the retarded. The combined data show an increase in de novo rather than familial rearrangements among the retarded; the increase in de novo rearrangements is specifically for non-Robertsonian translocation.