Source populations in coastal crabs: parameters affecting egg production

Benthic marine invertebrates may form metapopulations connected via propagule dispersal. Conservation efforts often target potential source coastlines to indirectly benefit areas depending on allochthonous offspring production. Besides population density, adult size structure, sex ratio, brooding frequency and the proportion of breeding individuals may significantly influence the reproductive output of benthic populations, but these effects have seldom been tested. We used rocky shore crabs to assess the spatial variability of such parameters at relevant scales for conservation purposes and to test their consistency over 2 consecutive years; we then used the data to address whether bottom-up processes or biological interactions might explain the patterns observed. We decomposed egg production rates into their components for the 2 most abundant brachyuran species inhabiting the intertidal rocky habitat. Adult density and brooding frequency varied consistently among shores for both species and largely explained the overall spatial trends of egg production. Temporally consistent patterns also included among-shore differences in the size of ovigerous females of the grapsid Pachygrapsus transversus and between-bay differences in the fecundity of the spider crab Epialtus brasiliensis. Sex ratio was remarkably constant in both. We found no positive or negative correlations between adult density and brooding frequency to support either the existence of a component Allee effect (lack of mate encounters) or an effect of intra-specific competition. Likewise, shore-specific potential growth in P. transversus does not negatively correlate with frequency of ovigerous individuals, as would be expected under a critical balance between these 2 processes. The patterns observed suggest that bottom-up drivers may best explain spatial trends in the reproductive output of these species.

Development of Dichelops melacanthus and its egg parasitoid Telenomus podisi reared on Bt-soybean MON 87701 x MON 89788 and its near conventional isoline under different temperatures.

Dichelops melacanthus was studied under controlled conditions (60 ± 10% RH and 14/10 h L/D photoperiod), and three constant temperatures (19, 25, and 31 ± 2 °C). Fresh pods of MON 87701 × MON 89788 soybeans and its near non-Bt isoline (A5547) were supplied to nymphs and adults. The biology of T. podisi was studied in the same controlled RH conditions, but only at the standard temperature of 25 ± 2°C. Overall, the development of D. melacanthus was better at higher temperatures, which accelerated the development of the stink bug without affecting adult biological parameters. No influence of Bt-soybeans on the biology of the pest was observed in any temperature studied, which shows that D. melacanthus is not affected by this transgenic soybean. The egg parasitoid T. podisi also was not harmed when it parasitized eggs of the pest fed with MON 87701 × MON 89788 soybeans, with similar results to those obtained in non-Bt isogenic soybeans. Thus, this study demonstrates that D. melacanthus is favored at high temperatures (31 ± 2 °C), and that neither did MON 87701 × MON 89788 soybean pods affect the development of the pest nor its parasitoid T. podisi.

Selective hydrogenation by novel composite supported Pd egg-shell catalysts

Two organic–inorganic mixed phase supports were prepared, comprising an alumina filler and polymers of different chemical nature. Four low loaded Pd catalysts were prepared. Good activities and selectivities were obtained during the hydrogenations of styrene, 1-heptyne and 2,3-butanedione. The catalysts were found to have excellent mechanical properties and could be used in applications needing high attrition resistance and crushing strength. In this sense, processes for fine chemicals using slurry reactors or processes for commodities using long packed beds could advantageously use them.

Plant Evolution: What Does It Take To Be an Egg?

The genetic regulation of cell patterning within plant gametophytes remains poorly understood. Now, two new studies in the liverwort Marchantia polymorpha shed light on the conserved function of an RKD transcription factor as a key regulator of egg cell fate in the land plant lineage.

Handle with care: historical geographies and difficult cultural legacies of egg-collecting

This thesis offers an examination of egg-collecting, which was a very popular pastime in Britain from the Victorian era well into the twentieth century. Collectors, both young and old, would often spend whole days and sometimes longer trips in a wide variety of different habitats, from sea shores to moorlands, wetlands to craggy mountainsides, searching for birds’ nests and the bounty to be found within them. Once collectors had found and taken eggs, they emptied out the contents; hence, they were really eggshell collectors. Some egg collectors claimed that egg-collecting was not just a hobby but a science, going by the name of oology, and seeking to establish oology as a recognised sub-discipline of ornithology, these collectors or oologists established formal institutions such as associations and societies, attended meetings where they exhibited unusual finds, and also contributed to specialist publications dedicated to oology. Egg-collecting was therefore many things at once: a culture of the British countryside, from where many eggs were taken; a culture of natural history, taking on the trappings of a science; and a culture of enthusiasm, providing a consuming passion for many collectors. By the early twentieth century, however, opposing voices were increasingly being raised, by conservation groups and other observers, about the impact that egg-collecting was having on bird populations and on the welfare of individual birds. By mid-century the tide had turned against the collectors, and egg-collecting in Britain was largely outlawed in 1954, with further restrictions imposed in 1981. While many egg collections have been lost or destroyed, some have been donated to museums, including Glasgow Museums (GM), which holds in its collections over 30,000 eggs. As a Collaborative Doctoral Award involving the University of Glasgow and GM, the project outlined in this thesis aims to bring to light and to life these egg collections, the activities of the collectors who originally built them, and the wider world of British egg-collecting. By researching archival material held by Glasgow Museums, published specialist egg-collecting journals and other published sources, as well as the eggs as a material archive, this thesis seeks to recover some of the practices and preoccupations of egg collectors. It also recounts the practical activities carried out during the course of the project at GM, particularly those involving a collection of eggs newly donated to the museum during the course of this project, culminating in a new temporary display of birds’ eggs at Glasgow Museums Resource Centre.

Non-hierarchical cluster analysis for body weight, age at first egg, egg production and egg weight in a laying hen strain.

2016

The influence of volatile semiochemicals from stink bug eggs and ovipositiondamaged plants on the foraging behaviour of the egg parasitoid Telenomus podisi.

2016

Supporting ICT diffusion in Australian construction organisations

Construction organisations comprise geographically dispersed virtually-linked suborganisations that work together to realise projects. They increasingly do so using information and communication technology (ICT) to communicate, coordinate their activities and to solve complex problems. One salient problem they face is how to effectively use requisite ICT tools. One important tool at their disposal is the self-help group, a body of people that organically spring up to solve shared problems. The more recognised term for this organisational form is a community of practice (COP). COPs generate knowledge networks that enhance and sustain competitive advantage and they are also used to help COP members actually use ICT tools. Etienne Wenger defines communities of practice as “groups of people informally bound together by shared expertise and passion for a joint enterprise” (Wenger and Snyder 2000, p139). This ‘chicken-or-egg’ issue about needing a COP to use the tools that are needed to effective broaden COPs (beyond co-located these groups) led us to explore how best to improve the process of ICT diffusion through construction organisations— primarily using people supported by technology that improves knowledge sharing. We present insights gained from recent PhD research results in this area. A semistructured interview approach was used to collect data from ICT strategists and users in the three large Australian construction organisations that are among the 10 or so first tier companies by annual dollar turnover in Australia. The interviewees were categorised into five organisational levels: IT strategist, implementer, project or engineering manager, site engineer and foreman. The focus of the study was on the organisation and the way that it implements ICT diffusion of a groupware ICT diffusion initiative. Several types of COP networks from the three Australian cases are identified: withinorganisation COP; institutional, implementer or technical support; project manager/engineer focussed; and collegial support. Also, there are cross-organisational COPs that organically emerge as a result of people sharing an interest or experience in something significant. Firstly, an institutional network is defined as a strategic group, interested in development of technology innovation within an organisation. This COP principally links business process domain experts with an ICT strategist.

Factors affecting reproductive performance of the prawn, Penaeus monodon

The growth of the Penaeus monodon prawn aquaculture industry in Australia is hampered by a reliance on wild-caught broodstock. This species has proven difficult to breed from if broodstock are reared in captivity. Studies were therefore carried out to investigate factors controlling reproduction and influencing egg quality. Results of the studies revealed that patterns of nutrient accumulation during early ovary development are altered by captive conditions, possibly contributing to reduce larval quality. The sinus gland hormones were shown, together with the environment, to regulate two stages of ovary development. In a separate study it was further revealed that the hormone methyl farnesoate (MF) could negatively regulate the final stages of ovary development. Lastly it was shown that broodstock reared in captivity are less likely to mate and that this is due to inherent problems in both the male and the female prawns.

Natural enemies of Paropsis atomaria Olivier (Coleoptera: Chrysomelidae) in south-eastern Queensland eucalypt plantations

Abstract A field survey for natural enemies of Paropsis atomaria was conducted at two south-eastern Queensland Eucalyptus cloeziana plantation sites during 2004–2005. Primary egg and larval parasitoids and associated hyperparasitoids were identified to genus or species, and parasitism rates were determined throughout the season. Predators were identified to family level but their impact was not quantified. P. atomaria adults were also examined as potential hosts for parasitic mites and nematodes. An undescribed species of Neopolycystus (Pteromalidae) was the major primary egg parasitoid species reared from egg batches, parasitising half of all egg batches collected. Three hyperparasitoid species (Baeoanusia albifunicle (Encyrtidae), Neblatticida sp. (Encyrtidae) and Aphaneromella sp. (Platygasteridae) were present, representing around one-quarter to one-third of all emergent wasps; this is the first host association record for Neopolycystus–B. albifunicle. In contrast to populations of P. atomaria from the Australian Capital Territory, primary larval parasitism was very low, around 1%, and attributable only to the tachinid flies Anagonia sp. and Paropsivora sp. However, the presence of the sit-and-wait larval hyperparasitoid, Perilampus sp. (Perilampidae) was high, emerging from around 17% of tachinid pupae, with planidia infesting a further 40% of unparasitised hosts. Three species of podapolipid mites parasitised sexually mature P. atomaria adults, while no nematodes were found in this study. Spiders were the most common predators and their abundance was positively correlated with P. atomaria adult and egg numbers. Although natural enemy species composition was identical between our two study sites, significant differences in abundance and frequency were found between sites

Conceptions of school-based youth health nursing

The aim of this research is to explore the meaning of the experience of school-based youth health nursing in Queensland, Australia. The research follows a qualitative approach and is based on indepth interviews. The dominant experience is negative because participants feel they have to battle to gain respect and survive in the school environment. The small, positive experience of school-based youth health nursing is related to student consultations. Student consultations are a ‘golden egg’ because participants gain a sense of reward from making a difference to student wellbeing. This paper proposes operational recommendations including those related to health promotion and professional development and strategic recommendations regarding this model of school nursing. The authors conclude, first, that this ‘golden egg’ should be promoted to ensure all school nurses reap the rewards, second, that this model of school nursing is not the most effective model.

Molecules, morphology, and ecology indicate a recent, amphibious ancestry for echidnas

The semiaquatic platypus and terrestrial echidnas (spiny anteaters) are the only living egg-laying mammals (monotremes). The fossil record has provided few clues as to their origins and the evolution of their ecological specializations; however, recent reassignment of the Early Cretaceous Teinolophos and Steropodon to the platypus lineage implies that platypuses and echidnas diverged >112.5 million years ago, reinforcing the notion of monotremes as living fossils. This placement is based primarily on characters related to a single feature, the enlarged mandibular canal, which supplies blood vessels and dense electrosensory receptors to the platypus bill. Our reevaluation of the morphological data instead groups platypus and echidnas to the exclusion of Teinolophos and Steropodon and suggests that an enlarged mandibular canal is ancestral for monotremes (partly reversed in echidnas, in association with general mandibular reduction). A multigene evaluation of the echidna–platypus divergence using both a relaxed molecular clock and direct fossil calibrations reveals a recent split of 19–48 million years ago. Platypus-like monotremes (Monotrematum) predate this divergence, indicating that echidnas had aquatically foraging ancestors that reinvaded terrestrial ecosystems. This ecological shift and the associated radiation of echidnas represent a recent expansion of niche space despite potential competition from marsupials. Monotremes might have survived the invasion of marsupials into Australasia by exploiting ecological niches in which marsupials are restricted by their reproductive mode. Morphology, ecology, and molecular biology together indicate that Teinolophos and Steropodon are basal monotremes rather than platypus relatives, and that living monotremes are a relatively recent radiation.

Studies of assisted reproduction in the spotted grass frog Limnodynastes tasmaniensis: ovulation, early development and microinjection (ICSI)

Assisted Reproductive Technologies (ART) offer a wide range of techniques that have the potential to augment efforts to conserve and manage endangered amphibians and improve wild and captive population numbers. Gametes and tissues of species nearing endangered or extinct status can be cryopreserved and stored in gene banks, to provide material that can be utilised in the future as ART methods are refined. The Spotted Grass Frog, Limnodynastes tasmaniensis, is an abundant amphibian species in South-Eastern Australia of the family Myobatrachidae, that is suitable for the development of ART systems that can be applied to the threatened and endangered myobatrachid and other amphibian species native to Australia. The aim of this study was to advance the understanding of ovulation, fertilisation and embryo nic development of Lim. tasmaniensis and in vitro manipulations of reproduction and development for use in the development of advanced ART procedures such as intracytoplasmic spermatozoon injection (ICSI), androgenesis and nuclear transfer. Ovulation in amphibians can be induced by protocols utilising natural or synthetic hormones. All protocols tested on Lim. tasmaniensis in this study required two injections and the most effective protocols continued to require a first injection of pituitary extracts to induce ovulation. The second injection was, however, successfully replaced by synthetic chorionic gonadotrophin at a threshold dosage of 100 iu and halved the number of cane toads required to source the pituitaries. A combination of LHRH and Pimozide offered a less effective protocol, that did not require the use of pituitary extracts, and avoided the risk of pathogen transfer associated with unsterilised pituitary extracts. Unfertilised eggs of Lim. tasmaniensis were exposed to media of various osmolalities to determine media effects on eggs and their surrounding jelly layers that might impact on egg viability and fertilisability. Osmolality had no effect upon the egg diameter, however, rapid swelling of the jelly layers occurred within 15 minutes of exposure to various media treatments and plateaued from 30-90 minutes without further expansion. Swelling of the jelly layers was increased in hypotonic media (2.5% SAR, H2O) and minimised in the isotonic media (100% SAR). The optimal conditions for the culture of Lim. tasmaniensis eggs were identified as a holding media of 100% SAR, followed by a medium change to 2.5% SAR at insemination. This sequence of media minimised the rate of swelling of the jelly layers prior to contact with the spermatozoa, and maximised the activation of spermatozoa and eggs throughout fertilisation and embryonic development. Embryos of Lim. tasmaniensis were cultured at four temperatures (13 C, 17 C, 23 C and 29 C), to determine the effect of temperature on cleavage and embryonic development rates. Embryonic development progressed through a sequence of stages that were not altered by changes in temperature. However cleavage rates were affected by changes in temperature as compared with normal embryonic growth at 23 C. Embryonic development was suspended at the lowest temperature (13 C) while embryonic viability was maintained. A moderate decrease in temperature (17 C) slowed cleavage, while the highest temperature (29 C) increased the cleavage rate, but decreased the embryo survival. Rates of embryonic development can be manipulated by changes in temperature and this method can be used to source blastomeres of a specific size/stage at a predetermined age or halt cleavage at specific stages for embryos or embryo derived cells to be included in ART procedures. This study produced the first report of the application of Intracytoplasmic Spermatozoon Injection (ICSI) in an Australian amphibian. Eggs that were activated by microinjection with a single spermatozoon (n=50) formed more deep, but abnormal, cleavage furrows post-injection (18/50, 36%), than surface changes (12/50, 24%). This result is in contrast to eggs injected without a spermatozoon (n=42), where the majority of eggs displayed limited surface changes (36/42, 86%), and few deep, abnormal furrows (3/42, 7%). Three advanced embryos (3/50, 6%) were produced by ICSI that developed to various stages within the culture system. Technical difficulties were encountered that prevented the generation of any metamorphs from ICSI tadpoles. Nevertheless, when these blocks to ICSI are overcome, the ICSI procedure will be both directly useful as an ART procedure in its own right, and the associated refinement of micromanipulation procedures will assist in the development of other ART procedures in Lim. tasmaniensis. A greater understanding of basic reproductive and developmental biology in Lim. tasmaniensis would greatly facilitate refinement of fertilisation by ICSI. Assisted Reproductive Technologies, in conjunction with gene banks may in the future regenerate extinct amphibian species, and assist in the recovery of declining amphibian populations nationally and worldwide.

Setting up a platform for plant-based influenza virus vaccine production in South Africa

Background During a global influenza pandemic, the vaccine requirements of developing countries can surpass their supply capabilities, if these exist at all, compelling them to rely on developed countries for stocks that may not be available in time. There is thus a need for developing countries in general to produce their own pandemic and possibly seasonal influenza vaccines. Here we describe the development of a plant-based platform for producing influenza vaccines locally, in South Africa. Plant-produced influenza vaccine candidates are quicker to develop and potentially cheaper than egg-produced influenza vaccines, and their production can be rapidly upscaled. In this study, we investigated the feasibility of producing a vaccine to the highly pathogenic avian influenza A subtype H5N1 virus, the most generally virulent influenza virus identified to date. Two variants of the haemagglutinin (HA) surface glycoprotein gene were synthesised for optimum expression in plants: these were the full-length HA gene (H5) and a truncated form lacking the transmembrane domain (H5tr). The genes were cloned into a panel of Agrobacterium tumefaciens binary plant expression vectors in order to test HA accumulation in different cell compartments. The constructs were transiently expressed in tobacco by means of agroinfiltration. Stable transgenic tobacco plants were also generated to provide seed for stable storage of the material as a pre-pandemic strategy. Results For both transient and transgenic expression systems the highest accumulation of full-length H5 protein occurred in the apoplastic spaces, while the highest accumulation of H5tr was in the endoplasmic reticulum. The H5 proteins were produced at relatively high concentrations in both systems. Following partial purification, haemagglutination and haemagglutination inhibition tests indicated that the conformation of the plant-produced HA variants was correct and the proteins were functional. The immunisation of chickens and mice with the candidate vaccines elicited HA-specific antibody responses. Conclusions We managed, after synthesis of two versions of a single gene, to produce by transient and transgenic expression in plants, two variants of a highly pathogenic avian influenza virus HA protein which could have vaccine potential. This is a proof of principle of the potential of plant-produced influenza vaccines as a feasible pandemic response strategy for South Africa and other developing countries.

Reproductive behavioural differences between wild-caught and pond-reared Penaeus monodon prawn broodstock

Ongoing problems exist with the commercial scale domestication of Penaeus monodon. One of the major issues, in terms of reproductive performance, is the low egg hatch rate of eggs from these captive bred prawns. The current study investigated the related issue of mating success. Time lapse video observations were conducted to compare the mating behaviour of pond-reared (domesticated) and wild-caught prawn P. monodon broodstock. Mating success of the pond-reared prawns was found to be low relative to wild-caught. It was determined that both male and female prawns contributed to this low mating rate suggesting both genders were impacted negatively by the domestication process. The causative factors for the low mating success are yet to be determined, however external physical abnormalities and lack of sexual maturity did not appear to play a role. The most notable behavioural difference between wild-caught and domesticated prawns was a reduced level of pursuit behaviour by domesticated males. This and other behavioural differences are discussed in relation to an increasing body of evidence that male prawns respond to sex pheromones produced by receptive females and that males detect these chemical signals in part, via their second antennal flagella. Accordingly we hypothesise that pond-reared (domesticated) females may have a reduced ability to produce or release sex pheromones and males, a reduced ability to detect them when compared to their wild-caught counterparts.