Stocking of captive-bred fish can cause long-term population decline and gene pool replacement: predictions from a population dynamics model incorporating density-dependent mortality

Releasing captive-bred fish into natural environments (stocking) is common in fisheries worldwide. Although stocking is believed to have a positive effect on fish abundance over the short term, little is known about the long-term consequences of recurrent stocking and its influence on natural populations. In fact, there are growing concerns that genetically maladapted captive-bred fish can eventually reduce the abundance of natural population. In this study, we develop a simple model to quantitatively investigate the condition under which recurrent stocking has long-term effects on the natural population. Using a population dynamics model that takes into account a density-dependent recruitment, a gene responsible for the fitness difference between wild and captive-bred fish, and hybridization between them, we show that there is little or no contribution of recurrent stocking to the stock enhancement without a replacement of the wild gene pool by the captive-bred gene pool. The model further predicted that stocking of an intermediate level causes a reduction, rather than enhancement, of population size over the long term. The population decline due to stocking was attributed to the fitness disadvantage of captive-bred fish and strong overcompensation at recruitment stage. These results suggest that it would be difficult to simultaneously attain population size recovery and conservation of the local gene pool when captive-bred fish have fitness disadvantage in the wild, although caution is needed when applying the predictions from the simplified model to a specific species or population.

Cancer, a disease of aging (part 1) - trends in older adult cancer mortality in Switzerland 1991-2008

It is crucial for aging societies to evaluate trends in cancer mortality rates of older adults. This study examined socio-demographic and regional characteristics specifically focused on the cancer mortality experience of older adults in Switzerland.

Cancer, a disease of aging (part 2) - risk factors for older adult cancer mortality in Switzerland 1991-2008

Cancer is disease of aging that disproportionately affects older adults and often results in considerable public health consequences. This study evaluated gender-age-specific cancer mortality risk factors in older adults in Switzerland with attention to the most common types of cancer.

Estimated mortality of adult HIV-infected patients starting treatment with combination antiretroviral therapy

To provide estimates of mortality among HIV-infected patients starting combination antiretroviral therapy.

A Swiss neighbourhood index of socioeconomic position: development and association with mortality

Area-based measures of socioeconomic position (SEP) suitable for epidemiological research are lacking in Switzerland. The authors developed the Swiss neighbourhood index of SEP (Swiss-SEP).

Marital status, living arrangement and mortality: does the association vary by gender?

Men appear to benefit more from being married than women with respect to mortality in middle age. However, there is some uncertainty about gender differences in mortality risks in older individuals, widowed, divorced and single individuals and about the impact of living arrangements.

Resting heart rate and incident heart failure and cardiovascular mortality in older adults: role of inflammation and endothelial dysfunction: the PROSPER study

Resting heart rate is a promising modifiable cardiovascular risk marker in older adults, but the mechanisms linking heart rate to cardiovascular disease are not fully understood. We aimed to assess the association between resting heart rate and incident heart failure (HF) and cardiovascular mortality, and to examine whether these associations might be attributable to systemic inflammation and endothelial dysfunction.

Elevated admission glucose and mortality in patients with acute pulmonary embolism

Although associated with adverse outcomes in other cardiopulmonary conditions, the prognostic value of elevated glucose in patients with acute pulmonary embolism (PE) is unknown. We sought to examine the association between glucose levels and mortality and hospital readmission rates for patients with PE.

Explaining the decrease in mortality from abdominal aortic aneurysm rupture

A steady rise in mortality from abdominal aortic aneurysm (AAA) was reported in the 1980s and 1990 s, although this is now declining rapidly. Reasons for the recent decline in mortality from AAA rupture are investigated here.

Decreasing mortality and changing patterns of causes of death in the Swiss HIV Cohort Study

Mortality among HIV-infected persons is decreasing, and causes of death are changing. Classification of deaths is hampered because of low autopsy rates, frequent deaths outside of hospitals, and shortcomings of International Statistical Classification of Diseases and Related Health Problems (ICD-10) coding.

Association between sustained virological response and all-cause mortality among patients with chronic hepatitis C and advanced hepatic fibrosis

Chronic hepatitis C virus (HCV) infection outcomes include liver failure, hepatocellular carcinoma (HCC), and liver-related death.