Human influence on brown trout juvenile body size during metapopulation expansion.

Change in body size can be driven by social (density) and non-social (environmental and spatial variation) factors. In expanding metapopulations, spatial sorting by means of dispersal on the expansion front can further drive the evolution of body size. However, human intervention can dramatically affect these founder effects. Using long-term monitoring of the colonization of the remote Kerguelen islands by brown trout, a facultative anadromous salmonid, we analyse body size variation in 32 naturally founded and 10 human-introduced populations over 57 years. In naturally founded populations, we find that spatial sorting promotes slow positive changes in body size on the expansion front, then that body size decreases as populations get older and local density increases. This pattern is, however, completely different in human-introduced populations, where body size remains constant or even increases as populations get older. The present findings confirm that changes in body size can be affected by metapopulation expansion, but that human influence, even in very remote environments, can fully alter this process.

Digging through model complexity: using hierarchical models to uncover evolutionary processes in the wild.

The growing interest for studying questions in the wild requires acknowledging that eco-evolutionary processes are complex, hierarchically structured and often partially observed or with measurement error. These issues have long been ignored in evolutionary biology, which might have led to flawed inference when addressing evolutionary questions. Hierarchical modelling (HM) has been proposed as a generic statistical framework to deal with complexity in ecological data and account for uncertainty. However, to date, HM has seldom been used to investigate evolutionary mechanisms possibly underlying observed patterns. Here, we contend the HM approach offers a relevant approach for the study of eco-evolutionary processes in the wild by confronting formal theories to empirical data through proper statistical inference. Studying eco-evolutionary processes requires considering the complete and often complex life histories of organisms. We show how this can be achieved by combining sequentially all life-history components and all available sources of information through HM. We demonstrate how eco-evolutionary processes may be poorly inferred or even missed without using the full potential of HM. As a case study, we use the Atlantic salmon and data on wild marked juveniles. We assess a reaction norm for migration and two potential trade-offs for survival. Overall, HM has a great potential to address evolutionary questions and investigate important processes that could not previously be assessed in laboratory or short time-scale studies.

A quantitative genetic analysis of hibernation emergence date in a wild population of Columbian ground squirrels.

The life history schedules of wild organisms have long attracted scientific interest, and, in light of ongoing climate change, an understanding of their genetic and environmental underpinnings is increasingly becoming of applied concern. We used a multi-generation pedigree and detailed phenotypic records, spanning 18 years, to estimate the quantitative genetic influences on the timing of hibernation emergence in a wild population of Columbian ground squirrels (Urocitellus columbianus). Emergence date was significantly heritable [h(2) = 0.22 ± 0.05 (in females) and 0.34 ± 0.14 (in males)], and there was a positive genetic correlation (r(G) = 0.76 ± 0.22) between male and female emergence dates. In adult females, the heritabilities of body mass at emergence and oestrous date were h(2) = 0.23 ± 0.09 and h(2) = 0.18 ± 0.12, respectively. The date of hibernation emergence has been hypothesized to have evolved so as to synchronize subsequent reproduction with upcoming peaks in vegetation abundance. In support of this hypothesis, although levels of phenotypic variance in emergence date were higher than oestrous date, there was a highly significant genetic correlation between the two (r(G) = 0.98 ± 0.01). Hibernation is a prominent feature in the annual cycle of many small mammals, but our understanding of its influences lags behind that for phenological traits in many other taxa. Our results provide the first insight into its quantitative genetic influences and thus help contribute to a more general understanding of its evolutionary significance.

Heritability of short-scale natal dispersal in a large-scale foraging bird, the wandering albatross.

Natal dispersal is a key life history trait for the evolution and adaptation of wild populations. Although its evolution has repeatedly been related to the social and environmental context faced by individuals, parent-offspring regressions have also highlighted a possible heritable component. In this study, we explore heritability of natal dispersal, at the scale of the sub-Antarctic Possession Island, for a large-scale foraging seabird, the Wandering albatross Diomedea exulans, exploiting a pedigree spanning over four decades and a maximum of four generations. The comparison of three different methods shows that heritability on the liability scale can vary drastically depending on the type of model (heritability from 6% to 86%), with a notable underestimation by restricted maximum likelihood animal models (6%) compared to Bayesian animal models (36%). In all cases, however, our results point to significant additive genetic variance in the individual propensity to disperse, after controlling for substantial effects of sex and natal colony. These results reveal promising evolutionary potential for short-scale natal dispersal, which could play a critical role for the long-term persistence of this species on the long run.

Combining capture-recapture data and pedigree information to assess heritability of demographic parameters in the wild.

Quantitative genetic analyses have been increasingly used to estimate the genetic basis of life-history traits in natural populations. Imperfect detection of individuals is inherent to studies that monitor populations in the wild, yet it is seldom accounted for by quantitative genetic studies, perhaps leading to flawed inference. To facilitate the inclusion of imperfect detection of individuals in such studies, we develop a method to estimate additive genetic variance and assess heritability for binary traits such as survival, using capture-recapture (CR) data. Our approach combines mixed-effects CR models with a threshold model to incorporate discrete data in a standard 'animal model' approach. We employ Markov chain Monte Carlo sampling in a Bayesian framework to estimate model parameters. We illustrate our approach using data from a wild population of blue tits (Cyanistes caeruleus) and present the first estimate of heritability of adult survival in the wild. In agreement with the prediction that selection should deplete additive genetic variance in fitness, we found that survival had low heritability. Because the detection process is incorporated, capture-recapture animal models (CRAM) provide unbiased quantitative genetics analyses of longitudinal data collected in the wild.

Neurovenous superficial inferior epigastric flaps in rats.

BACKGROUND: We performed an experimental study on 46 male rats to evaluate the vitality of superficial inferior epigastric neurovenous flaps performed following different procedures. METHODS: Rats were divided into 5 groups: A (n=6), B (n=10), C (n=10), D (n=10) and E (n=10). On each rat a hemi-abdominal flap based on the superficial inferior epigastric pedicle was raised. In group A the flap was sutured into its original position, isolating it from underlying tissues by a latex glove patch. In group B an arteriectomy of the superficial inferior epigastric artery was performed. In group C the superficial inferior epigastric artery was sectioned at its origin, without dissecting it out of the pedicle. In group D and E the same procedures performed respectively in group B and C were followed, but the epigastric pedicles were immediately explanted for optic microscope observation. Flap vitality in groups A, B and C was checked after 7 days. RESULTS: Flaps in group A appeared completely vital: the glove did not interfere with flap survival. All flaps in group B looked necrotic. In group C, 9 flaps survived completely and 1 flap underwent complete necrosis. Pedicle specimens of the viable flaps (group C) were explanted for observation under the optic microscope. Each specimen from groups C, D, E revealed a rich vascular plexus in the connective tissue around the pedicle. Seven days after surgery, neo-microangiogenesis was evident. CONCLUSIONS: The results witness the importance of perivenous and perineural arterioles for neurovenous flaps survival, also considering the adaptive increase in capillary development in the days following surgery.

A case of life-threatening sepsis after breast augmentation by fat injection.

A case is presented in which an aesthetic breast augmentation by fat injection led a young woman to a life-threatening sepsis due to bilateral mammary abscesses. Immediate and late complications of this procedure are considered; infection is the frightful complication that can lead to septic shock, affecting survival, aesthetic outcome, and reconstruction possibilities of the patient's breasts.

Ultrasound assisted liposuction for the palliative treatment of Madelung's disease: a case report.

Benign Symmetric Lipomatosis (Madelung's disease) is a rare disease, characterized by massive fatty deposits in the neck, the shoulders, and the upper extremities. The deformity is associated with chronic alcohol use, malignant tumors of the upper airways, neuropathy, diabetes mellitus, hyperlipidemia, and other metabolic disorders. Although the deformity is prone to recurrence, surgical removal via lipectomy or liposuction provides the only way of palliation. This paper describes the treatment of a 51-year-old man with a history of alcoholism and liver cirrhosis. He reported masses in his cervical and facial regions that had gradually enlarged over a period of 6 years. He also developed respiratory symptoms due to the fatty compression of his upper airways. Our experience with ultrasound-assisted liposuction for the palliative treatment of this disease is reported.

Do superficial epigastric veins of rats have valves?

The rat is a good model for experimental studies on the haemodynamic patterns of free-flap transfer but models involving the superficial epigastric vein have not been supported by the demonstration of the anatomical presence or absence of valves inside it. We performed a morphological study to assess whether or not valves are present inside the superficial epigastric vein of the rat. Segments of superficial epigastric veins were explanted from fifteen Sprague-Dawley rats. The lumen was studied with scanning electron microscopy after longitudinal or transverse incision of the venous walls. No valves were detected and we saw no evidence of their accidental removal. As most human veins do have valves, the clinical implications of haemodynamic data on reverse-flow island flaps obtained in rats must be considered very carefully.