Herd immunity drives the epidemic fadeout of avian cholera in Arctic-nesting seabirds.

Avian cholera, caused by the bacterium Pasteurella multocida, is a common and important infectious disease of wild birds in North America. Between 2005 and 2012, avian cholera caused annual mortality of widely varying magnitudes in Northern common eiders (Somateria mollissima borealis) breeding at the largest colony in the Canadian Arctic, Mitivik Island, Nunavut. Although herd immunity, in which a large proportion of the population acquires immunity to the disease, has been suggested to play a role in epidemic fadeout, immunological studies exploring this hypothesis have been missing.

[Dorsal preservation septorhinoplasty].

Background: Nasal dorsum deprojection is a very important tool in functional and aesthetic rhinoplasty. In classic techniques, resection of dorsal bone and cartilage renders dorsal reconstruction necessary. The concept of dorsal preservation rhinoplasty has been known for more than a century but has experienced a renaissance in recent years, with many critical technical modifications.

Costs of reproduction in a long-lived bird: large clutch size is associated with low survival in the presence of a highly virulent disease.

Fitness costs of reproduction are expected to be more pronounced when the environmental conditions deteriorate. We took advantage of a natural experiment to investigate the costs of reproduction among common eiders (Somateria mollissima) nesting at a site in the Arctic, where an avian cholera epizootic appeared at different magnitudes. We tested the predictions that larger reproductive effort (clutch size) is associated with lower survival or breeding probability the following year, and that this relationship was more pronounced under heightened exposure to the disease.

[Surgical techniques in hepatic resections: Ultrasonic aspirator versus Jet-Cutter. A prospective randomized clinical trial].

Aim Of The Study: For all resection-techniques of liver tissue intra- and post-operative blood-loss remains an important problem. Two novel resection-techniques the ultrasound-aspirator (CUSA) and the water-jet dissector (Jet-Cutter) appear to offer significant advantages regarding this problem. Aim of the present prospective clinical study was the comparison of these dissection techniques.

Impact of virtual reality imaging on hepatic liver tumor resection: calculation of risk.

The risk involved in partial liver resections depends mainly on tumor localization, invasion of central vascular structures, and parenchymal function. The imaging techniques available today (computed tomography, magnetic resonance imaging) allow us to detect precisely the extent of tumor invasion and their relationship to central vessels. The various three-dimensional reconstruction techniques are helpful with regard to a virtual planning of liver resections.