Oceanography and life history predict contrasting genetic population structure in two Antarctic fish species

Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a ‘seascape genetics’ approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting life histories, Champsocephalus gunnari and Notothenia rossii. The close accord between the model projections and empirical genetic structure demonstrated that passive dispersal during the planktonic early life stages is the dominant influence on patterns and extent of genetic structuring in both species. The shorter planktonic phase of C. gunnari restricts direct transport of larvae between distant populations, leading to stronger regional differentiation. By contrast, geographic distance did not affect differentiation in N. rossii, whose longer larval period promotes long-distance dispersal. Interannual variability in oceanographic flows strongly influenced the projected genetic structure, suggesting that shifts in circulation patterns due to climate change are likely to impact future genetic connectivity and opportunities for local adaptation, resilience and recovery from perturbations. Further development of realistic climate models is required to fully assess such potential impacts

Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis

Supported by F. Hoffmann–La Roche

Wirbelbildung im Bereich des Mittelmeerausstroms in hochauflösenden, numerischen Modellen

Es werden die Prozesse untersucht, die den Ausstrom von Mittelmeerwasser in den Golf von Cadiz und das iberische Becken bestimmen. Zwei unterschiedliche Modelltypen, die sich in der Repräsentation der Topographie im Modellgitter unterscheiden, werden verglichen und der Einfluß der Bodentopographie auf die Bildung und Ausbreitung des tiefen Randstroms untersucht. Ein weiterer Schwerpunkt der Modellanalysen liegt auf den Bildungsvorgängen und der Ausbreitung von mesoskaligen Wirbeln am Kap St. Vincent und südlich des Tejo-Plateaus. Hier sind vor allem die antizyklonalen Wirbel für die westwärtige Ausbreitung von Wassermassen mit einem starken Mittelmeerwassersignal in den östlichen Atlantik verantwortlich. Beide Modelle zeigen die Bildung und westwärtige Translation von Meddies in guter Übereinstimmung mit bisherigen Beobachtungen. Im zweiten Teil der Arbeit wird eine Analyse der Vorticitybalance durchgeführt. Dazu werden in Tankversuchen erzeugte, antizyklonale Wirbel betrachtet und mit entsprechenden in numerischen Modellen erzeugten Wirbeln verglichen. Durch die Verwendung numerischer Modelle werden zusätzliche Größen berechnet, die in den Tankversuchen nicht gemessen werden können

High-urgency kidney transplantation in the Eurotransplant Kidney Allocation System: success or waste of organs? The Eurotransplant 15-year all-centre survey.

BACKGROUND: In the Eurotransplant Kidney Allocation System (ETKAS), transplant candidates can be considered for high-urgency (HU) status in case of life-threatening inability to undergo renal replacement therapy. Data on the outcomes of HU transplantation are sparse and the benefit is controversial. METHODS: We systematically analysed data from 898 ET HU kidney transplant recipients from 61 transplant centres between 1996 and 2010 and investigated the 5-year patient and graft outcomes and differences between relevant subgroups. RESULTS: Kidney recipients with an HU status were younger (median 43 versus 55 years) and spent less time on the waiting list compared with non-HU recipients (34 versus 54 months). They received grafts with significantly more mismatches (mean 3.79 versus 2.42; P < 0.001) and the percentage of retransplantations was remarkably higher (37.5 versus 16.7%). Patient survival (P = 0.0053) and death with a functioning graft (DwFG; P < 0.0001) after HU transplantation were significantly worse than in non-HU recipients, whereas graft outcome was comparable (P = 0.094). Analysis according to the different HU indications revealed that recipients listed HU because of an imminent lack of access for dialysis had a significantly worse patient survival (P = 0.0053) and DwFG (P = 0.0462) compared with recipients with psychological problems and suicidality because of dialysis. In addition, retransplantation had a negative impact on patient and graft outcome. CONCLUSIONS: Facing organ shortages, increasing wait times and considerable mortality on dialysis, we question the current policy of HU allocation and propose more restrictive criteria with regard to individuals with vascular complications or repeated retransplantations in order to support patients on the non-HU waiting list with a much better long-term prognosis