A single panmictic population of endemic red crabs, Gecarcoidea natalis, on Christmas Island with high levels of genetic diversity

The red crab, Gecarcoidea natalis, is endemic to Christmas Island in the Indian Ocean and largely responsible for shaping the unique ecosystem found throughout the island's rainforests. However, the introduction and establishment of supercolonies of the highly invasive yellow crazy ant, Anoplolepis gracilipes, has decimated red crab numbers over the last several decades. This poses a significant risk to the future conservation of G. natalis and consequently threatens the integrity of the unique island ecosystem. Here we undertook a population genetic analysis of G. natalis using a combination of 11 microsatellite markers and sequencing of the mitochondrial cytochrome oxidase subunit I gene from samples collected on Christmas Island as well as a single location from North Keeling Island (located approximately 900 km west of Christmas Island). The genetic results indicate that G. natalis is a single panmictic population on Christmas Island, with no spatial genetic structure or restricted gene flow apparent between sampled locations. Further, G. natalis from North Keeling Island are not genetically distinct and are recent immigrants from Christmas Island. The effective population size of G. natalis has likely remained large and stable on Christmas Island throughout its evolutionary history with relatively moderate to high levels of genetic diversity in microsatellite loci and mitochondrial haplotypes assessed in this study. For management purposes G. natalis can be considered a single panmictic population, which should simplify conservation efforts for the genetic management of this iconic island species. © 2014 Springer Science+Business Media Dordrecht.

Population genetic studies on Australian freshwater crayfish, Cherax destructor (Crustacea: Parastacidae) using allozyme and RAPD markers

Allozyme and Random Amplified Polymorphic DNA (RAPD) variation was surveyed in the freshwater crayfish Cherax destructor Clark, an ecologically and commercially important species that is widespread throughout the freshwater systems of central Australia. At the intra-population level, allozymes revealed a similar level of variation to that found in other freshwater crayfish; RAPDs showed less diversity than allozymes, which was unexpected. At the inter-population level, both techniques revealed significant population structure, both within and between drainages. RAPD results were consistent with phylogeographic patterns previously identified using mtDNA. Although allozyme data showed little geographic pattern in relation to genetic variation based on multidimensional-scaling (MDS) plots on matrices of genetic distance, results of AMOVA and Mantel tests indicated significant population structuring. Each of the mtDNA lineages proposed in a previous study also showed significant genetic structure at similar levels as revealed by RAPDs but different levels by allozymes. These results reject hypotheses previously put forward on genetic homogenisation within the species due to wide-scale translocation. The implications of the findings for conservation and aquaculture of C. destructor are also discussed.

Barriers to cross-fertilization between populations of a widely dispersed Polychaete species are unlikely to have arisen through gametic compatibility arms-races

Although there are theoretical reasons to suspect that gametic incompatibility may develop readily among populations of broadcast spawning marine invertebrates, there have been very few studies documenting geographic patterns of interpopulation incompatibility for any species. To address this we determined how successfully individuals of the intertidal serpulid polychaete, Galeolaria caespitosa, can cross-fertilize within and among populations from across temperate Australia. Fertilization assays revealed asymmetrical differences between very distantly located populations from different coasts, with near-complete incompatibility between eggs from Sydney with sperm from Adelaide, but the reverse cross (Adelaide eggs, Sydney sperm) was reasonably compatible. Although that pattern was congruent with a clear difference in Cytochrome B sequences between worms on the south and east coasts of Australia, we also detected some indication of interpopulation incompatibility within the genetic grouping on east coast, between two populations separated by only 220 km. We then assessed whether commonly proposed gametic compatibility arms-races could account for these patterns. Our results suggest reduced gametic compatibility may reduce a female's maximum fertilization potential, resulting in a cost to this potential mechanism for reducing polyspermy. Consequently, the apparently rapid development of reproductive barriers here seems unlikely to have been driven by arms-races involving sexual conflict over fertilization rate.

Uteroplacental insufficiency and reducing litter size alters skeletal muscle mitochondrial biogenesis in a sex-specific manner in the adult rat

Uteroplacental insufficiency has been shown to impair insulin action and glucose homeostasis in adult offspring and may act in part via altered mitochondrial biogenesis and lipid balance in skeletal muscle. Bilateral uterine vessel ligation to induce uteroplacental insufficiency in offspring (Restricted) or sham surgery was performed on day 18 of gestation in rats. To match the litter size of Restricted offspring, a separate cohort of sham litters had litter size reduced to five at birth (Reduced Litter), which also restricted postnatal growth. Remaining litters from sham mothers were unaltered (Control). Offspring were studied at 6 mo of age. In males, both Restricted and Reduced Litter offspring had reduced gastrocnemius PPAR γ coactivator-1α (PGC-1 α) mRNA and protein, and mitochondrial transcription factor A (mtTFA) and cytochrome oxidase (COX) III mRNA (P < 0.05), whereas only Restricted had reduced skeletal muscle COX IV mRNA and protein and glycogen (P < 0.05), despite unaltered glucose tolerance, homeostasis model assessment (HOMA) and intramuscular triglycerides. In females, only gastrocnemius mtTFA mRNA was lower in Reduced Litter offspring (P < 0.05). Furthermore, glucose tolerance was not altered in any female offspring, although HOMA and intramuscular triglycerides increased in Restricted offspring (P < 0.05). It is concluded that restriction of growth due to uteroplacental insufficiency alters skeletal muscle mitochondrial biogenesis and metabolic characteristics, such as glycogen and lipid levels, in a sex-specific manner in the adult rat in the absence of impaired glucose tolerance. Furthermore, an adverse postnatal environment induced by reducing litter size also restricts growth and alters skeletal muscle mitochondrial biogenesis and metabolic characteristics in the adult rat.

Vitamin C and E supplementation prevents some of the cellular adaptations to endurance-training in humans

BACKGROUND: It is clear that reactive oxygen species (ROS) produced during skeletal muscle contraction have a regulatory role in skeletal muscle adaptation to endurance exercise. However, there is much controversy in the literature regarding whether attenuation of ROS by antioxidant supplementation can prevent these cellular adaptations. Therefore, the aim of this study was to determine whether vitamin C and E supplementation attenuates performance and cellular adaptations following acute endurance exercise and endurance training. METHODS: A double-blinded, placebo-controlled randomized control trial was conducted in eleven healthy young males. Participants were matched for peak oxygen consumption (VO2peak) and randomly allocated to placebo or antioxidant (vitamin C (2×500mg/day) and E (400IU/day)) groups. Following a four-week supplement loading period, participants completed acute exercise (10×4min cycling at 90% VO2peak, 2min active recovery). Vastus lateralis muscle samples were collected pre-, immediately-post- and 3h-post-exercise. Participants then completed four weeks of training (3 days/week) using the aforementioned exercise protocol while continuing supplementation. Following exercise training, participants again completed an acute exercise bout with muscle biopsies. RESULTS: Acute exercise tended to increase skeletal muscle oxidative stress as measured by oxidized glutathione (GSSG) (P=0.058) and F2-isoprostanes (P=0.056), with no significant effect of supplementation. Acute exercise significantly increased mRNA levels of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), mitochondrial transcription factor A (TFAM) and PGC related coactivator (PRC), with no effect of supplementation. Following endurance training, supplementation did not prevent significantly increased VO2peak, skeletal muscle levels of citrate synthase activity or mRNA or protein abundance of cytochrome oxidase subunit 4 (COX IV) (P<0.05). However, following training, vitamin C and E supplementation significantly attenuated increased skeletal muscle superoxide dismutase (SOD) activity and protein abundance of SOD2 and TFAM. CONCLUSION: Following acute exercise, supplementation with vitamin C and E did not attenuate skeletal muscle oxidative stress or increased gene expression of mitochondrial biogenesis markers. However, supplementation attenuated some (SOD, TFAM) of the increased skeletal muscle adaptations following training in healthy young men.

Conservation genetic studies of the endangered Cape Fear Shiner, Notropis mekistocholas (Teleostei: Cyprinidae)

Genetic variation at ten microsatellite lociand one anonymous-nuclear locus was assayed for three geographic samples of the criticallyendangered North American cyprinid Notropis mekistocholas (Cape Fear shiner). Despite low abundance of this species, there was little suggestion of small population effects; allele diversity and heterozygosity were relatively high, F_IS values within samples were non-significant, and genotypes were distributed in frequencies according to Hardy-Weinberg expectations. Genetic divergence among samples was minimal despite the presence of dams, constructed in the early1900s, that separate the sample sites. This suggests that recent gene flow has been sufficient to inhibit genetic divergence or that gene flow has been reduced but there has been insufficient time for genetic divergence to develop. Tests of heterozygosity excess were non-significant, suggesting that N.mekistocholas in the localities sampled have not undergone recent reductions ineffective population size. Future studies employing larger sample sizes to provide more robust tests of population structure and temporally separated samples to estimate contemporaneous N_e are warranted.

Low allozyme variation in snapper, Pagrus auratus, in Victoria, Australia

The population genetic structure of snapper, Pagrus auratus (Bloch and Schneider), in Victoria was investigated using six polymorphic allozyme loci. Fish were sampled from four sites in Victoria and single locations in South Australia, Western Australia and New Zealand. Although there were distinct genetic differences between the snapper populations from each of the Australian states and New Zealand, only minor and largely insignificant differences were detected among Victorian populations. The results are consistent with previous genetic and tagging studies that indicate no mixing between snapper stocks in Victoria and Spencer Gulf in South Australia. This justifies separate management of the snapper fisheries in these regions. The low levels of polymorphism and heterozygosity in Victorian snapper suggest an isolation by distance model of population structure rather than one of discrete subpopulations.

An introduction to eRoadmapping : providing learning paths for students and empowering teachers

This paper reports on the development of an innovative teaching strategy: an eRoadmap.  Based on the theory of conceptual mapping, the eRoadmap provides an interactive, hierarchical structure for course delivery, using the readily accessible platform provided by Microsoft PowerPoint.  For the student, the eRoadmap provides a self-paced learning environment which encourages student engagement; for the teacher, it provides an environment for the development of a course framework, and the integration of teaching materials from a variety of sources.  Futher advantages of the eRoadmap from the perspectives of both students and teachers are discussed, and future directions for development, evaluation and research are outlined.

The key learning area movement : A force for pedagogical change or a facade for continued conservatism?

Throughout the early 1990s the formal curriculum across all Australian States and Territories was re-organised to accommodate a Key Learning Area (KLA) focus.  The KLA approach to schooling marked a departure from an historical reliance on individualised school subjects as the organisers of disciplinary knowledge.  Indeed a KLA structure has the potential to promote interdisciplinary teaching and learning, a focus on the skills, values, attitudes and knowledge students are to learn and to break away from the sometimes divisive subject subcultures that permiate schools.  In short the potential for a KLA 'movement' of positive benefit to teaching and learning exists.

Over the last decade however, the impact of the 'KLA movement' on teacher practice has become more apparent.  Far from being a force for pedagogical change, some KLAs are merely re-badged versions of traditionalist conceptions of school subject and knowledge.  This paper draws on data from a study of New South Wales (NSW) history and Human Society and Its Environment (HSIE) teachers and provides an evidenced argument about the use and misuse of Key Learning Areas.

Phytophthora cinnamomi and Australia’s biodiversity : impacts, predictions and progress towards control

Phytophthora cinnamomi continues to cause devastating disease in Australian native vegetation and consequently the disease is listed by the Federal Government as a process that is threatening Australia’s biodiversity. Although several advances have been made in our understanding of how this soil-borne pathogen interacts with plants and of how we may tackle it in natural systems, our ability to control the disease is limited. The pathogen occurs widely across Australia but the severity of its impact is most evident within ecological communities of the south-west and south-east of the country. A regional impact summary for all states and territories shows the pathogen to be the cause of serious disease in numerous species, a significant number of which are rare and threatened. Many genera of endemic taxa have a high proportion of susceptible species including the iconic genera Banksia, Epacris and Xanthorrhoea. Long-term studies in Victoria have shown limited but probably unsustainable recovery of susceptible vegetation, given current management practices. Management of the disease in conservation reserves is reliant on hygiene, the use of chemicals and restriction of access, and has had only limited effectiveness and not provided complete control. The deleterious impacts of the disease on faunal habitat are reasonably well documented and demonstrate loss of individual animal species and changes in population structure and species abundance. Few plant species are known to be resistant to P. cinnamomi; however, investigations over several years have discovered the mechanisms by which some plants are able to survive infection, including the activation of defence-related genes and signalling pathways, the reinforcement of cell walls and accumulation of toxic metabolites. Manipulation of resistance and resistance-related mechanisms may provide avenues for protection against disease in otherwise susceptible species. Despite the advances made in Phytophthora research in Australia during the past 40 years, there is still much to be done to give land managers the resources to combat this disease. Recent State and Federal initiatives offer the prospect of a growing and broader awareness of the disease and its associated impacts. However, awareness must be translated into action as time is running out for the large number of susceptible, and potentially susceptible, species within vulnerable Australian ecological communities.

Microstructural analysis of pre-strained TRIP steel after fatigue testing

The widespread introduction of multiphase sheet steels in the automotive industry has led to considerable interest in the fatigue properties of these materials. The different microstructural phases within matelials such as TRIP steels can influence the fatigue behaviour due to the manner in which the cyclic strain is accommodated within these phases. In this study fully reversed straincontrolled fatigue tests were perfonnrmed on a commercially-produced uncoated TRIP 780 steel both in the as-received and 20 % prestrained condition. The pre-strained TRIP steel showed significant cyclic softening at higher strain amplitudes, whereas some initial work hardening was observed at lower strain amplitudes before cyclic softening. The cyclic stabilised strength of the pre-strained TRIP steel was independent of strain amplitude, while the cyclic stabilised strength of the as-received TRIP steel increased with strain amplitude. Transmission Electron Microscopy TEM was used to examine the effect of the cyclic deformation on the microstructure of the different conditions, with the differences in fatigue behaviour explained based on the differences in the deformation structure formed within the steel (i.e. dislocation density and sub-structure and microband formation).

Patterns of use and exchange of genetic resources of the striped catfish Pangasianodon hypophthalmus (Sauvage 1878)

The present paper reviews the use and exchange of genetic resources of the migratory freshwater fish Pangasianodon hypophthalmus (Sauvage 1878) (the striped or sutchi catfish). This species is naturally distributed in the Mekong River and Chao Phraya River basins, and is cultured in several countries, but current production occurs predominantly in the Mekong Delta, Vietnam. Catfish aquaculture in Vietnam has evolved from extensive systems using wild-caught seed to an intensified farming system that is entirely dependent on hatchery-produced seed. Genetic improvement programmes on catfish have started in Vietnam, but are still in their infancy. Genetic studies have revealed several subpopulations of the species. Apart from selective breeding and the production of hybrids with closely related species, no other technologies have been applied to improve the performance of catfish. The use and exchange of P. hypophthalmus genetic resources have brought benefits to rural communities. Aquaculture development of catfish has evolved from being seen as an exploitation of natural resources to an activity that can reduce pressure on wild fish populations. Management of aquaculture stocks need to be rationalised to minimise the potential impacts it might cause to wild populations.

1948 and 1968 Czech refugee settlers in Australia : a comparison of the settlement and integration processes among two waves of settlers

Nearly eighteen years ago when I first became interested in the history and sociology of Australian immigration, I was particularly attracted by the fact and opportunity to incorporate immigration settlement, experience and accomplishments in my history teaching in secondary school. In particular it was the area of the settlement of Australia that needed a fuller understanding in the teaching of Australian history. By that I mean it was needed to show that there were many other ethnic groups besides the Anglo-Saxon group which had participated in the development of Australia since 1788. Since the end of World War II, the Australian population has doubled, the population structure and characteristics have changed and knowledge about the diverse groups forming the Australian nation is now sought. Sane ethnic groups, mainly the numerically large, have been studied and numerous reports are available. But many of the smaller groups have attracted little interest among Australian scholars. This was one of the reasons that I decided to research the behaviour of one of the smaller groups - the Czechs - to find out about their immigration history to Australia; their immigration processes such as re-settlement and re-establishment; and their community life since World War II. Because of the scarcity of written materials on Czechs in Australia, I had to rely on interviews, personal reminiscenses, letters and documents translated from the Czech language. I should like to express my gratitude to all people and officials of Czech ethnic organisations and clubs in Australia, who agreed to be interviewed and who provided me with documentary material so important for my work. Respecting the wishes of my interviewees their anonymity had to be preserved. In the course of my research, I have received substantial help and the encouragement from the Editor of the now extinct Czech language paper Newspaper Hlas domova, Mr. F.V., whose co-operation is gratefully recognised. I am also grateful to Associate Professor William D. Rubinstein for his help and encouragement in all stages of my work. The introductory part of the study is covered in Chapter One. She reasons for the need to increase Australia's population after World War II and an analysis of the development of settlement in Australia between 1947 and 1984 are discussed. The emigration of Czechs into Australia and their place in the post-war immigration scheme is introduced. To obtain an overview of how Czechs have emigrated around the world, the literature describing their settlement is compared. Also discussed in the literature on Czech settlement in Australia from an historical point of view. The studies on the concept of ethnicity and settlement in Australia are used to document the theoretical issues for an understanding of Australian society. This chapter also contains aspects of sources and research, shewing the processes of documentary research, interviews and related matters. In Chapter Two the history of Czech emigration is discussed, covering the period from the seventeenth to the twentieth century. The first contacts with Australia are highlighted, continuing into the inter-war period and finally the re-settlement of Czechs after World War II. To understand why Czechs left their ancestral country after World War II, the political situation in Czechoslovakia is analysed. The third chapter concentrates mainly in the 1948 wave of settlers, who left Czechoslovakia after the communist take-over in 1948. Their means of departure from their homeland, selection of Australia as a new homeland and their re-settlement and re-establishment are discussed. Their attitudes after their arrival and their later stages of their settlement are analysed. The formation of numerous Czech ethnic organisations which mushroomed between 1950 and 1954 led to an active community life which began to change about five years after their arrival. These charges led to disorganisation of Czech community's life. The causes of these changes which were influential for the failure of the 1948 group to establish a viable community in Australia are analysed. In Chapter Four the wave of 1968 is viewed, their arrival and settling is covered. The study of their group attitudes and formation of group institutions is the main part of this section. A comparison of my data of the two waves, 1948 and 1968, reveals the information that these two groups did not develop the harmonious relationship expected of them as members of the one ethnic group. Chapter Five discusses immigration typologies and concentrates on the differences between legal and illegal emigrants from the Czechoslovak point of view. The integration processes of Czechs and their incorporation into Australian society are discussed. The sixth chapter sums up the findings of this disertation and states the influences which were responsible for the divisions in Czech ethnic life in Australia in the 1980s.

Population structure and life history characteristics of euastacus bispinosus and cherax destructor (Parastacidae) in the Grampians National Park, Australia

Despite being the most widely distributed and cultured freshwater crayfish species in Australia, relatively little is known about the ecology of Cherax destructor outside of captivity. Similarly, few ecological studies have been conducted on the large and threatened stream dwelling Australian freshwater crayfish Euastacus bispinosus. A series of seasonal sampling surveys over two years investigated the population structure, life history and reproductive timing of C. destructor in fire dam habitats, and of E. bispinosus in channel (stream) habitats, in the Grampians National Park in south-west Victoria, Australia. Cherax destructor individuals in the largest size class (50 – 59.95 mm OCL) were not abundant during the study, while those belonging to the 0 – 9.95 mm OCL size class were more frequent in summer than at other times of year, suggesting synchronous recruitment in fire dam habitats. Individuals in the reproductively active mid-size classes were also frequent in summer. For E. bispinosus, sex ratios in spring always favoured females, although there were no clear trends for other times of year. Gravid E. bispinosus females were found in winter and spring throughout the study, and were sexually mature at a smaller size than has previously been reported.

Genetic status of an endemic marine mammal, the Australian fur seal, following historical harvesting

Genetic variation, and the way in which it is partitioned among populations, has implications for a species’ survival and evolutionary potential. Such information is particularly important for the successful conservation and management of species that have experienced past human impacts and potential losses of genetic diversity. Overharvesting of the Australian fur seal Arctocephalus pusillus doriferus in the 18th and 19th centuries resulted in severe population reductions and elimination of an estimated 17 of 26 colonies. Currently, the subspecies is recovering and c. 20 000 pups are produced annually at 13 colony sites, most of which are situated in Bass Strait in south-eastern Australia. Genetic analysis of samples collected from pups captured at nine colonies revealed no difference in allelic diversity or heterozygosity at five microsatellite loci and no differences in haplotype diversity within a 344 bp region of the mitochondrial DNA control region. There was some evidence for isolation by distance but the program STRUCTURE predicted a single cluster of individuals. Gene flow among colonies appears to be substantial at present, indicating that the Australian fur seal is currently a single, panmictic unit.