Estimating survival and movements using both live and dead recoveries : a case study of oystercatchers confronted with habitat change

1. Animals facing partial habitat loss can try to survive in the remaining habitat or emigrate. Effects on survival and movements should be studied simultaneously since survival rates may be underestimated if emigrants are not considered, and since emigrants may experience reduced survival.

2. We analysed movements and survival of adult wintering oystercatcher Haematopus ostralegus in response to the 1986–1987 partial closure of the Oosterschelde in the Dutch Delta. This reduced by one-third the tidal area of this major European wintering area for waders.

3. We developed a novel variant of a multistate capture–recapture model allowing simultaneous estimation of survival and movement between sites using a mixture of data (live recaptures and dead recoveries). We used a two-step process, first estimating movements between sites followed by site-specific survival rates.

4. Most birds were faithful to their ringing site. Winter survival was negatively affected by winter severity and was lowest among birds changing wintering site (i.e. moving outside of the Oosterschelde).

5. During mild winters, survival rates were very high, and similar to before the closure in both changed and unchanged sectors of the Oosterschelde. However, the combined effect of habitat loss with severe winters decreased the survival of birds from changed sectors and induced emigration.

6. The coastal engineering project coincided with three severe winters and high food stock, making assessment of its effects difficult. However, the habitat loss seems to have had less impact on adult survival and movements than did winter severity.

7. Synthesis and applications. Human-induced habitat change may result in population decline through costly emigration or reduced survival or reproduction of individuals that stay. Long-term monitoring of marked individuals helps to understand how populations respond to environmental change, but site-specific survival and movement rates should be integrated in the same model in order to maximize the information yield. Our modelling approach facilitates this because it allows the inclusion of recoveries from outside the study area.

Uncoupling the mechanisms that facilitate cell survival in hormone-deprived bovine mammary explants

Mammary explants can be hormonally stimulated to mimic the biochemical changes that occur during lactogenesis. Previous studies using mammary explants concluded that the addition of exogenous macromolecules were required for mammary epithelial cells to remain viable in culture. The present study examines the survival of mammary explants from the dairy cow using milk protein gene expression as a functional marker of lactation and cell viability. Mammary explants cultured from late pregnant cows mimicked lactogenesis and showed significantly elevated milk protein gene expression after 3 days of culture with lactogenic hormones. The subsequent removal of exogenous hormones from the media for 10 days resulted in the down-regulation of milk protein genes. During this time, the mammary explants remained hormone responsive, the alveolar architecture was maintained and the expression of milk protein genes was re-induced after a second challenge with lactogenic hormones. We report that a population of bovine mammary epithelial cells have an intrinsic capacity to remain viable and hormone responsive for extended periods in chemically defined media without any exogenous macromolecules. In addition, we found mammary explant viability was dependent on de novo protein and RNA synthesis. Global functional microarray analysis showed that differential expression of genes involved in energy production, immune responses, oxidative stress and apoptosis signalling might contribute to cell survival. As the decline in milk production in dairy cattle after peak lactation results in considerable economic loss, the identification of novel survival genes may be used as genetic markers for breeding programmes to improve lactational persistency in dairy cows.

Living to tell the tale : survival and connection

Memories too sharp for public handling most often stay in our private worlds where we all live, at some point or other, with the weight of regret, or sadness of things lost. The idea of living to tell the tale becomes in itself the story, and we keep counsel with that idea in early morning dreams, or late night fears. For most of us, that is as far as our story goes. Some women, however, move beyond that instinctive silence born of trauma. When the story they have to tell is also a trauma of nationality, of intercultural connection, and of women’s shared sense of survival, it can be tough reading. Judith McNeil’s memoir, The Girl With the Cardboard Port was set down, like this, in front of me.

Cancer survival in Australia 1992–1997 : geographic categories and socioeconomic status

Cancer Survival in Australia 1992-1997 is the first national analysis of how cancer survival varies by socioeconomic status and geographic region. It presents an analysis of five-year relative survival proportions by geographic category and socioeconomic status for persons diagnosed with cancer during the years 1992-1997.This analysis is presented by age and sex for all cancers (Excluding non-melanocytic skin cancers) combined and for the following National Health Priority Area cancers - colorectal cancer, cancer of the lung, melanoma, cancer of the breast (females only), cancer of the cervix, cancer of the prostate, and non-Hodgkin's lymphoma.This report is the third in a series of three reports on relative survival after being diagnosed with cancer. It is an important reference for all those interested in the health of Australians.

Comparing the seasonal survival of resident and migratory oystercatchers : carry-over effects of habitat quality and weather conditions

Events happening in one season can affect life-history traits at (the) subsequent season(s) by carry-over effects. Wintering conditions are known to affect breeding success, but few studies have investigated carry-over effects on survival. The Eurasian oystercatcher Haematopus ostralegus is a coastal wader with sedentary populations at temperate sites and migratory populations in northern breeding grounds of Europe. We pooled continental European ringing-recovery datasets from 1975 to 2000 to estimate winter and summer survival rates of migrant and resident populations and to investigate long-term effects of winter habitat changes. During mild climatic periods, adults of both migratory and resident populations exhibited survival rates 2% lower in summer than in winter. Severe winters reduced survival rates (down to 25% reduction) and were often followed by a decline in survival during the following summer, via short-term carry-over effects. Habitat changes in the Dutch wintering grounds caused a reduction in food stocks, leading to reduced survival rates, particularly in young birds. Therefore, wintering habitat changes resulted in long-term (>10 years) 8.7 and 9.4% decrease in adult annual survival of migrant and resident populations respectively. Studying the impact of carry-over effects is crucial for understanding the life history of migratory birds and the development of conservation measures.

Introgression of domesticated alleles into a wild trout genotype and the impact on seasonal survival in natural lakes

We tested the fitness consequences of introgression of fast-growing domesticated fish into a wild population. Fry from wild and domesticated rainbow trout (Oncorhynchus mykiss) crosses, F1 hybrids, and first- and second-generation backcrosses were released into two natural lakes. Parentage analysis using microsatellite loci facilitated the identification of survivors, so fitness was estimated in nature from the first-feeding stage. Results indicated that under certain conditions, domesticated fish survived at least as well as wild fish within the same environment. Relative growth and survival of the crosses, however, were highly dependent on environment. During the first summer, fastest-growing crosses had the highest survival, but this trend was reversed after one winter and another summer. Although the F1 hybrids showed evidence of outbreeding depression because of the disruption of local adaptation, there was little evidence of outbreeding depression in the backcrosses, and the second-generation backcrosses exhibited a wild-type phenotype. This information is relevant for assessing the multigenerational risk of escaped or released domesticated fish should they successfully interbreed with wild populations and provides information on how to minimize detrimental impacts of a conservation breeding and/or management programme. These data also further understanding of the selection pressures in nature that maintain submaximal rates of growth.

Early diagnosis and treatment of necrotizing fasciitis can improve survival : an observational intensive care unit cohort study

Background
The aim of this study was to describe the clinical characteristics, causative pathogens, clinical management and outcomes of patients presenting to a tertiary adult Australian intensive care unit (ICU) with a diagnosis of necrotizing fasciitis (NF).
Methods
This retrospective observational study was conducted in a 19-bed, level III, adult ICU in a 450-bed tertiary, regional hospital. Clinical databases were accessed for patients diagnosed with NF and admitted to The Geelong Hospital ICU between 1 February 2000 and 1 June 2011. Information on severity of sepsis, surgical procedures and microbiological results were collected.
Results
Twenty patients with NF were identified. The median age was 52.5 years and 38% were female. The overall mortality rate was 8.3%. Common co-morbidities were diabetes (21%) and heart failure (17%), although 50% of patients had no co-morbidities. Group A Streptococcus was the identified pathogen in 11 (46%) patients, and Streptococcus milleri group in 5 (21%) patients. Hyperbaric oxygen therapy was not used in the majority of patients. The initial antibiotics administered were active against subsequently cultured bacteria in 83% of patients. Median time to surgical debridement was 20 h. Diagnosis and management was delayed in the nosocomial group.
Conclusions
This study reports physiological data, aetiology and therapeutic interventions in NF for an adult tertiary hospital. We demonstrate one of the lowest reported mortality rates, with early surgical debridement being achieved in the majority of patients. The main delay was found to be in the diagnosis of NF.

Maternal transfer of mercury to the developing embryo/fetus : is there a safe level?

Mercury (Hg) exposure is ubiquitous in modern society via vaccines, fish/crustacea, dental amalgam, food, water, and the atmosphere. This article examines Hg exposure in the context of primary exposure to pregnant women and secondary exposure experienced by their unborn babies. Babies in utero are particularly at risk of higher Hg exposure than adults (on a dose/weight basis through maternal Hg transfer via the placenta), and are more susceptible to adverse effects from mercury and its biologically active compounds. It is, therefore, critical that regulatory advisories around maximum safe Hg exposures account for pregnant women and secondary exposure that children in utero experience. This study focused on standardized embryonic and fetal Hg exposures via primary exposure to the pregnant mother of two common Hg sources (dietary fish and parenteral vaccines). Data demonstrated that Hg exposures, particularly during the first trimester of pregnancy, at well-established dose/weight ratios produced severe damage to humans including death. In light of research suggestive of a mercuric risk factor for childhood conditions such as tic disorders, cerebral palsy, and autism, it is essential that Hg advisories account for secondary prenatal human exposures.