30 resultados para Eggs.

em Queensland University of Technology - ePrints Archive


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Most studies of in vitro fertilisation (IVF) outcomes use cycle-based data and fail to account for women who use repeated IVF cycles. The objective of this study was to examine the association between the number of eggs collected (EC) and the percentage fertilised normally, and women’s self-reported medical, personal and social histories. This study involved a crosssectional survey of infertile women (aged 27-46 years) recruited from four privately-owned fertility clinics located in major cities of Australia. Regression modeling was used to estimate the mean EC and mean percentage of eggs fertilised normally: adjusted for age at EC. Appropriate statistical methods were used to take account of repeated IVF cycles by the same women. Among 121 participants who returned the survey and completed 286 IVF cycles, the mean age at EC was 35.2 years (SD 4.5). Women’s age at EC was strongly associated with the number of EC: <30 years, 11.7 EC; 30.0-< 35 years, 10.6 EC; 35.0-<40.0 years, 7.3 EC; 40.0+ years, 8.1 EC; p<.0001. Prolonged use of oral contraceptives was associated with lower numbers of EC: never used, 14.6 EC; 0-2 years, 11.7 EC; 3-5 years, 8.5 EC; 6þ years, 8.2 EC; p=.04. Polycystic ovary syndrome (PCOS) was associated with more EC: have PCOS, 11.5 EC; no, 8.3 EC; p=.01. Occupational exposures may be detrimental to normal fertilisation: professional roles, 58.8%; trade and service roles, 51.8%; manual and other roles, 63.3%; p=.02. In conclusion, women’s age remains the most significant characteristic associated with EC but not the percentage of eggs fertilised normally.

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Almost everyone experiences a nosebleed at some time during their lives. In many cases, these nosebleeds are self-limiting, resolve without medical attention, and tend to be nothing more than a minor nuisance. However, in some instances they can be life threatening and urgent medical attention is required. One of these instances is when people who have Glanzmann's thrombasthenia (GT) experience a nosebleed...

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Synopsis and review of the Australian feature film Bad Eggs, directed by Tony Martin.

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Diachasmimorpha kraussii (Hymenoptera: Braconidae: Opiinae) is a koinobiont larval parasitoid of dacine fruit flies of the genus Bactrocera (Diptera: Tephritidae) in its native range (Australia, Papua New Guinea, Solomon Islands). The wasp is a potentially important control agent for pest fruit flies, having been considered for both classical and inundative biological control releases. I investigated the host searching, selection and utilisation mechanisms of the wasp against native host flies within its native range (Australia). Such studies are rare in opiine research where the majority of studies, because of the applied nature of the research, have been carried out using host flies and environments which are novel to the wasps. Diachasmimorpha kraussii oviposited equally into maggots of four fruit fly species, all of which coexist with the wasp in its native range (Australia), when tested in a choice trial using a uniform artificial diet media. While eggs laid into Bactrocera tryoni and B. jarvisi developed successfully through to adult wasps, eggs laid into B. cucumis and B. cacuminata were encapsulated. These results suggest that direct larval cues are not an important element in host selection by D. kraussii. Further exploring how D. kraussii locates suitable host larvae, I investigated the role of plant cues in host searching and selection. This was examined in a laboratory choice trial using uninfested fruit or fruit infested with either B. tryoni or B. jarvisi maggots. The results showed a consistent preference ranking among infested fruits by the wasp, with guava and peach most preferred, but with no response to uninfested fruits. Thus, it appears the wasp uses chemical cues emitted in response to fruit fly larval infestation for host location, but does not use cues from uninfested fruits. To further tease apart the role of (i) suitable and non-suitable maggots, (ii) infested and uninfested fruits of different plant species, and (iii) adult flies, in wasp host location and selection, I carried out a series of behavioural tests where I manipulated these attributes in a field cage. These trials confirmed that D. kraussii did not respond to cues in uninfested fruits, that there were consistent preferences by the wasps for different maggot infested fruits, that fruit preference did not vary depending on whether the maggots were physiologically suitable or not suitable for wasp offspring development, and finally, that adult flies appear to play a secondary role as indicators of larval infestation. To investigate wasp behaviour in an unrestrained environment, I concurrently observed diurnal foraging behaviours of both the wasp and one of its host fly in a small nectarine orchard. Wasp behaviour, both spatially and temporally, was not correlated with adult fruit fly behaviour or abundance. This study reinforced the point that infested fruit seems to be the primary cue used by foraging wasps. Wasp and fly feeding and mating was not observed in the orchard, implying these activities are occurring elsewhere. It is highly unlikely that these behaviours were happening within the orchard during the night as both insects are diurnal. As the final component of investigating host location, I carried out a habitat preference study for the wasp at the landscape scale. Using infested sentinel fruits, I tested the parasitism rate of B. tryoni in eucalyptus sclerophyll forest, rainforest and suburbia in South East Queensland. Although, rainforest is the likely endemic habitat of both B. tryoni and D. kraussii, B. tryoni abundance is significantly greater in suburban environments followed by eucalyptus sclerophyll forest. Parasitism rate was found to be higher in suburbia than in the eucalyptus sclerophyll forest, while no parasitism was recorded in the rainforest. This result suggests that wasps orient within the landscape towards areas of high host density and are not restricted by habitat types. Results from the different experiments suggest that host searching, selection and utilisation behaviour of D. kraussii are strongly influenced by cues associated with fruit fly larval feeding. Cues from uninfested fruits, the host larvae themselves, and the adult host flies play minimal roles. The discussion focuses on the fit of D. kraussii to Vinson’s classical parasitoid host location model and the implications of results for biological control, including recommendations for host and plant preference screening protocols and release regimes.

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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.

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Abstract Neopolycystus sp. is the only primary egg parasitoid associated with the pest beetle Paropsis atomaria in subtropical eucalypt plantations, but its impact on its host populations is unknown. The simplified ecosystem represented by the plantation habitat, lack of interspecific competition for host and parasitoid, and the multivoltinism of the host population makes this an ideal system for quantifying the direct and indirect effects of egg parasitism, and hence, effects on host population dynamics. Within-, between- and overall-egg-batch parasitism rates were determined at three field sites over two field seasons, and up to seven host generations. The effect of exposure time (egg batch age), host density proximity to native forest and water sources on egg parasitism rates was also tested. Neopolycystus sp. exerts a significant influence on P. atomaria populations in Eucalyptus cloeziana. plantations in south-eastern Queensland, causing the direct (13%) and indirect (15%) mortality of almost one-third of all eggs in the field. Across seasons and generations, 45% of egg batches were parasitised, with a within-batch parasitism rate of around 30%. Between-batch parasitism increased up to 5–6 days after oviposition in the field, although within-batch parasitism rates generally did not. However, there were few apparent patterns to egg parasitism, with rates often varying significantly between sites and seasons.

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Diachasmimorpha kraussii is an endoparasitoid of larval dacine fruit flies. To date the only host preference study done on D. kraussii has used fruit flies from outside its native range (Australia, Papua New Guinea, Solomon Islands). In contrast, this paper investigates host preference for four fly species (Bactrocera cacuminata, B. cucumis, B. jarvisi and B. tryoni) which occur sympatrically with the wasp in the Australian component of the native range. Diachasmimorpha kraussii oviposition preference, host suitability (parasitism rate, number of progeny, sex ratio), and offspring performance measures (body length, hind tibial length, developmental time) were investigated with respect to the four fly species in the laboratory in both no-choice and choice situations. The parasitoid accepted all four fruit fly species for oviposition in both no-choice and choice tests; however, adult wasps only emerged from B. jarvisi and B. tryoni. Through dissection, it was demonstrated that parasitoid eggs were encapsulated in both B. cacuminata and B. cucumis. Between the two suitable hosts, measurements of oviposition preference, host suitability and offspring performance measurements either did not vary significantly, or varied in an inconsistent manner. Based on our results, and a related study by other authors, we conclude that D. krausii, at the point of oviposition, cannot discriminate between physiologically suitable and unsuitable hosts.

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The individual history of infertile women, as well as their age, may influence their response to in vitro fertilisation (IVF) cycles. This study examined the associations between women’s histories and two IVF outcomes: eggs aspirated (EA) and proportion with normal, two-pronuclei (2PN), fertilisation. This is a cross-sectional survey of infertile women (n=141, 27-46 years) from a multi-centre clinical sample. Participants completed a survey of socio-demographic, relationship, lifestyle, reproductive and fertility factors, medical conditions and recurrent symptoms. Among participants with heterosexual partners (n=122), associations between women’s histories and EA or 2PN fertilisation were analysed using linear and logistic modelling, respectively, adjusted for age at EA and accounting for multiple IVF cycles (n=313 cycles). Participants aged 35+ years had reproductive histories of miscarriage only (16.9%), termination only (9.9%) or birth+termination (5.6%) that were 2-, 3- and 4-fold higher, respectively, than those aged <35 years (7.1%, 2.9%, 1.4%). More years of oral contraceptive use were associated with a lower mean EA: never used, 14.6 EA; 0-2 years, 11.7 EA; 3-5 years, 8.6 EA; 6þ years, 8.2 EA (p=.04). Participants with polycystic ovary syndrome had a higher mean EA (11.5) than those without the condition (8.3 EA, p<.01). Participants in trade or service occupations had lower proportions of 2PN fertilisation (51.7%) than participants in other occupations (professional, 58.6%; manual/other, 63.6%, p<.02). Increasing women’s age and prolonged used of oral contraceptives were associated with lower EA from IVF cycles; PCOS was associated with higher EA. Occupational exposures may have a detrimental effect on normal fertilisation rates.

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Worldwide, there are few large-scale epidemiological studies on infertility. In Australia, population-based research on infertility is limited to a few small-scale studies. Therefore, the prevalence of infertility and unmet need for specialist medical advice and treatment cannot be estimated reliably. Women who have used assisted reproductive technologies (ART) are recorded in treatment registries. However, there are many infertile women who are excluded from these clinical populations because they neither seek advice nor use treatment. The thesis was based on a biopsychosocial model of health and used the methods of reproductive epidemiology to address the lack of national data on the prevalence of infertility in Australia. Firstly, numbers of births and pregnancy losses were investigated in two generations of women participating in the Australian Longitudinal Study on Women’s Health (ALSWH). The ALSWH is a broad-ranging, longitudinal examination of biological, psychological and social factors that impact on women’s health and wellbeing. Women from three age cohorts were randomly sampled from the population using the universal public health insurance (i.e., Medicare) database and ALSWH participants were representative of the female population. However, the studies in the thesis only involved data from two cohorts. The younger cohort were born in 1973-78 and completed up to four mailed surveys between 1996 (when they were aged 18-23 years, n=14247) and 2006 (28-33 years, n=9145). The mid-aged cohort were born in 1946-51 and completed four mailed surveys between 1996 (when they were aged 45-50 years n=13715) and 2004 (53-58 years, n=10905). Compared to other studies that focus on outcomes of single pregnancies, these studies included all pregnancy outcomes by developing comprehensive reproductive histories for each woman. Pregnancy outcomes included birth, miscarriage, stillbirth, termination and ectopic pregnancy. Women in the youngest cohort (born in 1973-78) were only just reaching their peak childbearing years and many (44%) had yet to report their first pregnancy outcome. Women from the mid-aged cohort (born 1946-51) had completed their reproductive lives and 92% were able to report on their lifetime pregnancy outcomes. Pregnancy losses, especially miscarriage, were common for both generations of women. Secondly, the prevalence of infertility, seeking medical advice and using treatment was identified for these two generations of women. For the older generation, the lifetime prevalence of infertility and demand for treatment was investigated in the context of the specialist medical services which became available circa 1980. By this time, however, most of these older women had already been pregnant and completed their families. For women who experienced infertility (11%), their options for advice and treatment were limited and less than half (42%) had used any treatment. More recently for the younger generation of women, who were aged 28-33 years in 2006, specialist advice and treatment were extensively available. Among women who had tried to conceive or had been pregnant (n=5936), 17% had experienced infertility and the majority (72%) were able to access medical advice. However, after seeking advice only half of these infertile women had used treatment with fertility hormones or in vitro fertilisation (IVF). Overall for infertile women aged up to 33 years, only one-third had used these treatments. Thirdly, the barriers to accessing medical advice and using treatment for infertility were identified for women aged less than 34 years. Among a community sample of infertile women aged 28-33 years (ALSWH participants), self-reported depression was found to be a barrier to accessing medical advice. The characteristics of these infertile women in the community who had (n=121) or had not (n=110) used treatment were compared to infertile women aged 27-33 years (n=59) attending four fertility clinics. Compared to infertile women in the community, living in major cities and having private health insurance were associated with early use of treatment for infertility at specialist clinics by women aged <34 years. In contrast to most clinical studies of IVF, the final study reported in the thesis took into account repeated IVF cycles and the impact of women’s individual histories on IVF outcomes. Among 121 infertile women (aged 27-46 years) who had 286 IVF cycles, older age and prolonged use of the oral contraceptive pill were associated with fewer eggs collected. Further, women in particular occupations had lower proportions of eggs fertilised normally than women in other occupational groups. These studies form the first large-scale epidemiological examination of infertility in Australia. The finding that two-thirds of women with infertility had not used treatment indicates that there is an unmet need for specialist treatment in women aged less than 34 years. However, barriers to accessing treatment prevent women using ART at a younger age when there is a higher chance of pregnancy.

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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.

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The larvae of particular Ogmograptis spp. produce distinctive scribbles on some smooth-barked Eucalyptus spp. which are a common feature on many ornamental and forest trees in Australia. However, although they are conspicuous in the environment the systematics and biology of the genus has been poorly studied. This has been addressed through detailed field and laboratory studies of their biology of three species (O. racemosa Horak sp. nov., O. fraxinoides Horak sp. nov., O. scribula Meyrick), in conjunction with a comprehensive taxonomic revision support by a molecular phylogeny utilising the mitochondrial Cox1 and nuclear 18S genes. In brief, eggs are laid in bark depressions and the first instar larvae bore into the bark to the level where the future cork cambium forms (the phellegen). Early instar larvae bore wide, arcing tracks in this layer before forming a tighter zig-zag shaped pattern. The second last instar turns and bores either closely parallel to the initial mine or doubles its width, along the zig-zag shaped mine. The final instar possesses legs and a spinneret (unlike the earlier instars) and feeds exclusively on callus tissue which forms within the zig-zag shaped mine formed by the previous instar, before emerging from the bark to pupate at the base of the tree. The scars of mines them become visible scribble following the shedding of bark. Sequence data confirm the placement of Ogmograptis within the Bucculatricidae, suggest that the larvae responsible for the ‘ghost scribbles’ (unpigmented, raised scars found on smooth-barked eucalypts) are members of the genus Tritymba, and support the morphology-based species groups proposed for Ogmograptis. The formerly monotypic genus Ogmograptis Meyrick is revised and divided into three species groups. Eleven new species are described: Ogmograptis fraxinoides Horak sp. nov., Ogmograptis racemosa Horak sp. nov. and Ogmograptis pilularis Horak sp. nov. forming the scribula group with Ogmograptis scribula Meyrick; Ogmograptis maxdayi Horak sp. nov., Ogmograptis barloworum Horak sp. nov., Ogmograptis paucidentatus Horak sp. nov., Ogmograptis rodens Horak sp. nov., Ogmograptis bignathifer Horak sp. nov. and Ogmograptis inornatus Horak sp. nov. as the maxdayi group; Ogmograptis bipunctatus Horak sp. nov., Ogmograptis pulcher Horak sp. nov., Ogmograptis triradiata (Turner) comb. nov. and Ogmograptis centrospila (Turner) comb. nov. as the triradiata group. Ogmograptis notosema (Meyrick) cannot be assigned to a species group as the holotype has not been located. Three unique synapomorphies, all derived from immatures, redefine the family Bucculatricidae, uniting Ogmograptis, Tritymba Meyrick (both Australian) and Leucoedemia Scoble & Scholtz (African) with Bucculatrix Zeller, which is the sister group of the southern hemisphere genera. The systematic history of Ogmograptis and the Bucculatricidae is discussed.

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Queensland fruit fly, Bactrocera tryoni (Froggatt), is a polyphagous pest, and many citrus types are included among its hosts. While quantification of citrus host use by B. tryoni is lacking, citrus is generally considered a ‘low pressure’ crop. This paper investigates B. tryoni female oviposition preference and offspring performance in five citrus types; Murcott mandarin (Citrus reticulata), Navel orange and Valencia orange (Citrus sinensis), Eureka lemon (Citrus limon) and yellow grapefruit (Citrus paradisi). Oviposition preference was investigated in laboratory-based choice and no-choice experiments, while immature survival and offspring performance were investigated by infesting fruits in the laboratory and evaluating pupal recovery, pupal emergence and F1 fecundity. Fruit size, Brix level and peel toughness were also measured for correlation with host use. Bactrocera tryoni demonstrated an oviposition preference hierarchy among the citrus fruits tested; Murcott and grapefruit were most preferred for oviposition and lemon the least, while preference for Navel and Valencia was intermediate. Peel toughness was negatively correlated with B. tryoni oviposition preference, while no significant correlations were detected between oviposition and Brix level or fruit size. Immature survival in the tested fruit was very low. Murcott was the best host (21% pupal recovery), while all other citrus types that showed pupal recovery of 6% or lower and no pupae were recovered from Valencia orange. In pupae recovered from Navel orange and lemon, adult eclosion was greatly reduced, while in grapefruit and lemon, no eggs were recovered from F1 adults. Based on these laboratory results, many commercial citrus varieties appear to be poor hosts for B. tryoni and may pose a low post-harvest and quarantine risk. These findings need to be confirmed in the field, as they impact on both pre-harvest and post-harvest countermeasures.