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.

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.