Assessing textbook outcomes following major liver surgery in association with obesity at a referral academic center.

INTRODUCTION: Outcomes of major surgeries in tertiary educational hospitals have been complicated by the referral of high-risk patients and the participation of trainees in surgical procedures. We analyzed outcomes of major hepatectomies in a tertiary academic setting emphasizing the role of training and obesity on textbook outcomes (TO). MATERIALS AND METHODS: 971 adult patients who underwent open major hepatectomy (Mesohepatectomy [n = 111], hemihepatectomy [n = 610], and extended hepatectomy [n = 250]) were evaluated. A TO was defined as: a negative resection margin, no grade B/C bile leak, no major complications, no in-hospital mortality, and no 30-day readmission. TOs were compared following operations performed by senior surgeons and those performed by junior surgeons under the supervision of senior surgeons and between patients with and without obesity. RESULTS: TO was achieved in 70.1% of patients overall (78.4% in mesohepatectomy, 73.1% in hemihepatectomy, and 59.2% in extended hepatectomy). The rate of TO was similar following operations performed by and supervised by a senior surgeon (69.3% vs 71.0%, p = 0.570). The rate of TO was significantly lower in patients with obesity (41.5% vs 74.6%, p < 0.001). Factors including increased age (odds ratio [OR] for 10-year increase = 0.83, 95% confidence interval [CI]: 0.73-0.96, p = 0.009), obesity (OR = 0.25, 95%CI: 0.16-0.37, p < 0.001), biliodigestive anastomosis (OR = 0.27, 95%CI: 0.19-0.40, p < 0.001), and portal vein resection (OR = 0.49, 95%CI: 0.28-0.87, p = 0.014) lower the rate of TO. CONCLUSION: Promising outcomes are possible after major hepatectomy in an academic setting. Obese patients and those undergoing more complex surgeries had a higher risk of poor postoperative outcomes.

Large-scale PVA modeling of insects in cultivated grasslands: The role of dispersal in mitigating the effects of management schedules under climate change.

In many species, dispersal is decisive for survival in a changing climate. Simulation models for population dynamics under climate change thus need to account for this factor. Moreover, large numbers of species inhabiting agricultural landscapes are subject to disturbances induced by human land use. We included dispersal in the HiLEG model that we previously developed to study the interaction between climate change and agricultural land use in single populations. Here, the model was parameterized for the large marsh grasshopper (LMG) in cultivated grasslands of North Germany to analyze (1) the species development and dispersal success depending on the severity of climate change in subregions, (2) the additional effect of grassland cover on dispersal success, and (3) the role of dispersal in compensating for detrimental grassland mowing. Our model simulated population dynamics in 60-year periods (2020-2079) on a fine temporal (daily) and high spatial (250 × 250 m2) scale in 107 subregions, altogether encompassing a range of different grassland cover, climate change projections, and mowing schedules. We show that climate change alone would allow the LMG to thrive and expand, while grassland cover played a minor role. Some mowing schedules that were harmful to the LMG nevertheless allowed the species to moderately expand its range. Especially under minor climate change, in many subregions dispersal allowed for mowing early in the year, which is economically beneficial for farmers. More severe climate change could facilitate LMG expansion to uninhabited regions but would require suitable mowing schedules along the path. These insights can be transferred to other species, given that the LMG is considered a representative of grassland communities. For more specific predictions on the dynamics of other species affected by climate change and land use, the publicly available HiLEG model can be easily adapted to the characteristics of their life cycle.

A quantitative approach for the design of robust and cost-effective conservation policies under uncertain climate change: The case of grasshopper conservation in Schleswig-Holstein, Germany.

Climate is a major determinant of the world's distribution of biodiversity and species ranges are expected to shift as the climate changes. For conservation policies to be cost-effective in the long run these changes need to be taken into account. To some extent, policies can be adapted over time, but transaction costs, lock-in effects and path dependence limit the extent to which such adaptation is possible. Thus it is desirable that conservation policies be designed so that they are cost-effective in the long run even without future adaptations. Given that the future climate change is highly uncertain, the policies need to be robust to climatic uncertainty. In this paper we present an approach for the robustness analysis with regard to the cost-effectiveness of conservation policies in the face of uncertain climate change. The approach is applied to the conservation of a grasshopper species in the German federal state of Schleswig-Holstein. For the assessment of the cost-effectiveness of considered policies we develop a climate-ecological-economic model. We show that in the near future all considered policies have a similar level of robustness, while in the more distant future the policies differ substantially in their robustness and a trade-off emerges between the expected performance and robustness of a policy.