19 resultados para Survivorship

em Deakin Research Online - Australia


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A study of the healing journeys of cancer survivors. The research questions were: "Do cancer survivors have anything in common?" "Is there such a phenomenon as cancer survivorship?" Ten exceptional survivors were interviewed in depth and their stories were analysed for themes. These themes were Overcoming issues of commitment, challenge, control, caring and confidence. The thesis also explores the issues of obstacles to survivorship. These were couses, costs and controversies. The conclusion is that healing journeys will never be prescriptive but that they will always be possible.

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This chapter:
•  explores the notion of living with chronic illness as a journey;
•  explores the concepts of enduring and uncertainity as aspects of the
   suffering associated with living with chronic illness;
•  defines resilience
•  explores the ways in which people develop and use resilient strategies
    in the face of chronic illness;
•  describes survivorship as an outcome of resilience; and
•  discusses the role of nurses and other caring professionals in relation to
    supporting a person through their suffering, and to develop their resilience
    in the face of that suffering.

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Life history theory predicts that individuals make trade-offs between investment in current reproduction, future reproductive potential and success in order to maximise lifetime reproductive success (LRS). Factors that may influence LRS in seabirds include delayed maturity, small clutches, high adults survivorship and long life spans. Studies have shown that reproductive success of seabirds increases with age and experience. Australasian gannets are long-lived seabirds that typically commence breeding at five or six years of age. A small colony of gannets was monitored over 12 years. This study aimed to identify patterns of long-term individual breeding biology. Results indicate that nest site, pair bond duration, age and breeding experience are all important factors in reproductive success. Relationships were found between breeding success and several variables including breeding experience, pair bond duration and nest site quality. Identifying and understanding the factors that contribute to individuals’ reproductive success is of critical importance for future conservation and management of seabird species.

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The Australian fur seal (Arctocephalus pusillus doriferus) was severely over-exploited in the 18th and 19th centuries and until relatively recently its population had remained steady at well below estimated presealing levels. However, the population is now increasing rapidly (6%–20% per annum) throughout its range and there is a need to understand its dynamics in order to assess the potential extent and impact of interactions with fisheries. Age distribution (n = 156) and pregnancy rate (n = 110) were determined for adult females collected at a breeding colony on Seal Rocks, southeast Australia, in 1971–1972. Mean ± SE and maximum observed ages were 9.37 ± 0.41 and 20 years (n = 1), respectively. A stochastic modelling approach was used to fit an age distribution to the observed age-structure data and calculate rates of recruitment and adult survival. Annual adult female survival and recruitment rates between 1954 and 1971 were 0.478 ± 0.029 (mean ± SE) and 0.121 ± 0.007, respectively, suggesting that the population was experiencing a decline during the 1960s. The pregnancy rate increased from 78% at 3 years of age to an average of 85% between 4–13 years of age before significantly decreasing in older females (the oldest was 19 years of age). There was no significant effect of body mass or condition on the probability of a female being pregnant (P > 0.5 in both cases) and the nutritional burden of lactation did not appear to affect pregnancy rates or gestational performance. These findings suggest that the low survivorship was due to density-independent effects such as mortality resulting from interactions with fishers, which are known to have been common at the time. The recent increase in the population is consistent with anecdotal evidence that such interactions have decreased as fishing practices have changed.

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The population dynamics of the infaunal bivalve Soletellina alba was investigated at three sites situated within close proximity to the mouth of the Hopkins River estuary. The initial study design was planned to examine the importance of winter flooding to the persistence of this bivalve mollusc within the Hopkins estuary, since mass mortalities have been observed during previous years coincident with periods of winter flooding. Unfortunately, the climatic conditions experienced during this study were atypical compared to the long-term average, so detailed sampling was limited to two, unanticipated, non-flood years rather than two, highly anticipated, flood years. This hampered my ability to conduct complete tests of the importance of winter flooding. Patterns of river discharge and the frequency and duration of mouth opening and closing differed greatly from that expected. Unexpectedly, periods of mouth closure were not always associated with periods of minimal river discharge; low salinities were another unexpected result during an extended period of mouth closure during 1998. As expected, salinities varied considerably with increasing water depth when the estuary mouth was open. Mouth closure lead to salinities becoming more uniform between water depths but hypoxic and anoxic conditions became evident via stratification in the water column at 1 m below the Australian Height Datum (AHD). Other than trends associated with increased water depth, significant variation was not evident between measurements of salinity taken from three sites within close proximity of the estuary mouth (approximately 500 m), or during changes in tide. The most pertinent anomaly was the absence of winter flooding. The distribution and abundance of juvenile and adult S. alba was variable across all Dates, Sites and Channel elevations (i.e. water depths) sampled during this study. An experimental test comparing the recruitment of juveniles at different channel elevations and in sediments of varying particle size was conducted during an exceptionally successful period of recruitment during 1999. The results of these tests showed that recruitment was greatest at the shallowest channel elevation used, and there was little evidence that sediment particle size influenced recruitment. In contrast to 1999, recruitment during 1997 or 1998 was extremely poor. Growth rates were monitored using tagged individuals held in caged and uncaged plots, which revealed that growth was highly variable among individuals, but not between Sites. These tests also revealed that growth was negligible during the colder, winter months, and that the fastest growing individuals were capable of growing 0.2 mm/day. Mixed results were obtained for tests of potential cage artifacts and the influence of handling. Caging and differing amounts of handling did not appear to influence growth, but there was evidence that cages and handling influenced bivalve condition and number of mortalities. These direct tests appeared to be the most appropriate method for determining growth rates of this species, since attempts to analyse length-frequency data were made difficult by the apparent convergence of cohorts, and shell aging is difficult due to the thin, fragile nature of the shell. As expected, mass mortalities were observed during the flood of 1996, but not during the two non-flood years of 1997 and 1998. There were, however, some considerable declines in abundances at some channel elevations during the two non-flood years. However, these declines were attributable to the complete disappearance of individuals, rather than the sudden presence of numerous, recently dead individuals that typify observed declines during winter flooding. The complete disappearance of individuals suggest that S. alba may be capable of post-settlement emigration, or that they were consumed by an unknown predator. Salinity tolerance tests showed that bivalves exposed to low salinities (≤6 ppt), exhibited poorer condition and took longer to re-burrow into sediments than those exposed to greater salinities (≥14 ppt), while death of bivalves exposed to salinities ≤1 ppt occurred after 8 days of exposure. These tests provide evidence that low salinities are probably the principal cause of mass mortalities during winter flooding, although the interaction between salinity, temperature and turbidity also deserve consideration. The results of this study indicate that certain aspects of winter flooding, especially salinity, are responsible for the mass mortalities of S. alba rather than the result of a short-lived life history. I hypothesise that the survival of very young juveniles (between 0.5 and 1 mm shell length) and rapid growth rates are important features of the life history of S. alba that explain its successful persistence within the Hopkins River estuary. The rapid rates of growth suggest that it may be possible for juveniles that survive winter flooding to grow, reach sexual maturity, and reproduce before the onset of the next flood event. Unfortunately, the increased survivorship of juveniles during periods of winter flooding was not demonstrated by this study because of the absence of winter flooding and also relatively poor recruitment. It is highly likely that this species is capable of completing it entire life cycle within the estuary since the absence of other nearby populations, together with periods of mouth closure, are likely to greatly limit the potential contribution made by larvae entering from the surrounding marine environment. This study has added considerably to our knowledge of how infauna cope with life in the intermittently closing estuaries that typify semi-arid coastlines in the Southern Hemisphere.

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Local adaptation in response to fine-scale spatial heterogeneity is well documented in terrestrial ecosystems. In contrast, in marine environments local adaptation has rarely been documented or rigorously explored. This may reflect real or anticipated effects of genetic homogenization, resulting from widespread dispersal in the sea. However, evolutionary theory predicts that for the many benthic species with complex life histories that include both sexual and asexual phases, each parental habitat patch should become dominated by the fittest and most competitive clones. In this study we used genotypic mapping to show that within headlands, clones of the sea anemone Actinia tenebrosa show restricted distributions to specific habitats despite the potential for more widespread dispersal. On these same shores we used reciprocal transplant experiments that revealed strikingly better performance of clones within their natal rather than foreign habitats as judged by survivorship, asexual fecundity, and growth. These findings highlight the importance of selection for fine-scale environmental adaptation in marine taxa and imply that the genotypic structure of populations reflects extensive periods of interclonal competition and site-specific selection.

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The warming of coastal oceans due to climate change is increasing the overwinter survival of tropical fishes transported to temperate latitudes by ocean currents. However, the processes governing early post-arrival mortality are complex and can result in minimum threshold temperatures for overwinter survival, which are greater than those predicted based upon physiological temperature tolerances alone. This 3.5 mo laboratory study monitored the early performance of a tropical damselfish Abudefduf vaigiensis that occurs commonly during austral summer along the SE Australian coast, under nominal summer and winter water temperatures, and compares results with a co-occurring year-round resident of the same family, Parma microlepis. Survivorship, feeding rate, growth and burst swimming ability (as a measure of predator escape ability) were all reduced for the tropical species at winter water temperatures compared to those in summer, whereas the temperate species experienced no mortality and only feeding rate was reduced at colder temperatures. These results suggest that observed minimum threshold survival temperatures may be greater than predicted by physiology alone, due to lowered food intake combined with increased predation risk (a longer time at vulnerable sizes and reduced escape ability). Overwinter survival is a significant hurdle in pole-ward range expansions of tropical fishes, and a better understanding of its complex processes will allow for more accurate predictions of changes in biodiversity as coastal ocean temperatures continue to increase due to climate change.

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Objective : To examine prospective associations of television viewing time with quality of life, following a colorectal cancer diagnosis.

Methods : One thousand, nine hundred and sixty-six colorectal cancer survivors were recruited through the Queensland Cancer Registry. Interviews were conducted at 5, 12, 24, and 36 months post-diagnosis. Generalized linear mixed models estimated the effects of television viewing time on quality of life.

Results : Participants who watched ≥5 h of television per day had a 16% lower total quality of life score than did participants reporting ≤2 h per day. Deleterious associations of television viewing time were found with all quality of life subscales: functional well-being showed the strongest association (23% difference in quality of life scores between highest and lowest television viewing categories), and social well-being the weakest association (6% difference). Participants who increased their television viewing by one category (e.g., ≤2 h, increasing to 3–4 h per day) had a proportional decrease of some 6% in their quality of life score (intra-individual effect).

Conclusions : The deleterious associations of television viewing time with quality of life were clinically significant and consistent over time. Decreasing sedentary behavior may be an important behavioral strategy to enhance the quality of life of cancer survivors.

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Sex ratios in clutches of moorhens (Gallinula chloropus) in Britain were measured on 83 chicks using the sex-linked CHD1 gene (Chromo-helicase/ATPase-DNA binding protein 1). Among birds, the female is the hetero-gametic sex (Z and W chromosomes), and the male is homogametic (two copies of the Z chromosome). We report variation among the PCR-amplified fragments of the CHD1Z, and the death of nearly all heterozygous male chicks (92%). In contrast, survivorship among females and homozygote males was 54–60%. Mortality in male heterozygotes was significantly higher than that of male homozygotes (P < 0.001). Chick and egg biometrics were not significantly different between these males. The CHD1Z was unlikely to be directly responsible but may have been hitchhiked by the causal gene(s). The observations appear to follow a classic underdominance (heterozygote inferiority) pattern, but raise the paradoxical question of why one form of the Z chromosome has not been fixed, as is expected from evolutionary theory. We discuss possible explanations and include a survey of British populations based on skin specimens.

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Purpose: To evaluate the performance of a canal filling hinge device for complex knee arthroplasty. Methods: Thirty-seven (4 primary hinge implantation and 33 revision cases) patients who had undergone arthroplasty with the S-ROM third generation hinge device for a combination of massive bone loss or ligamentous insufficiency were prospectively examined with a minimum of 5-year follow-up. Median age at surgery was 72 years (range: 43 to 87 years). Principal indications included aseptic loosening or massive osteolysis (24 cases), infection (8 cases) and periprosthetic fracture (4 cases). All patients exhibited either grade 2 (N = 12) or grade 3 (N = 25) AORI bone loss or a grade 3 medial ligament deficiency. Results: One patient experienced implant failure (71 months), and one patient suffered late deep infection (36 months). Mean WOMAC score improved from 27 to 62. Four patients required patellar resurfacing for persistent pain. The 5-year survivorship was 86%. Conclusions: While the S-ROM device may offer satisfactory medium term outcome for complex end stage knee disease, we report a high rate of debilitating anterior knee symptoms.

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Prostate cancer (PCa) poses many emotional and physical challenges for men following treatment. The unmet support needs of these men are well documented, and access to psychosocial support remains problematic.

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Prostate cancer poses many challenges for both the man and his partner. Partners have reported a range of issues that impact their own mental health following their partner's diagnosis of prostate cancer. The aim of this review is to summarise and critically evaluate the current literature reporting psychosocial intervention studies for partners of prostate cancer patients.

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Resilience of seagrass meadows relies on the ability of seagrass to successfully recolonise denuded areas or disperse to new areas. While seed germination and rhizome extension have been explored as modes of recovery and expansion, the contribution of seagrass viviparous propagules to meadow population dynamics has received little attention. Here, we investigated the potential of seagrass viviparous propagules to act as dispersal vectors. We performed a series of density surveys, and in situ and mesocosm-based experiments in Port Phillip Bay, VIC, Australia, using Zostera nigricaulis, a species known to produce viviparous propagules. Production of viviparous propagules was higher at sites with high wind and current exposure, compared to more sheltered environments. A number of propagules remained buoyant and healthy for more than 85 days, suggesting the capacity for relatively long-distance dispersal. Transplanted propagules were found to have improved survivorship within seagrass habitats compared to bare sediment over the short term (4 weeks); however, all propagules suffered longer-term (<100 days) mortality in field experiments. Conditions outside of meadows, including sediment scouring, reduced the likelihood of successful colonisation in bare sediment. Furthermore, sediment characteristics within meadows, such as a smaller grain size and high organic content, positively influenced propagule establishment. This research provides preliminary evidence that propagules have the potential to act as an important long-distance dispersal vector, a process that has previously gone unrecognised. Even though successful establishment of propagules may be rare, viviparous propagules show great potential for seagrass populations given they are facing global decline. © 2014 Coastal and Estuarine Research Federation.