Summary1. The complex, nonlinear response of dryland systems to grazing and climatic variations is a challenge to management of these lands. Predicted climatic changes will impact the desertification of drylands under domestic livestock production. Consequently, there is an urgent need to understand the response of drylands to grazing under climate change. 2. We enhanced and parameterized an ecohydrological savanna model to assess the impacts of a range of climate change scenarios on the response of a semi-arid African savanna to grazing. We focused on the effects of temperature and CO 2 level increase in combination with changes in interand intra-annual precipitation patterns on the long-term dynamics of three major plant functional types. 3. We found that the capacity of the savanna to sustain livestock grazing was strongly influenced by climate change. Increased mean annual precipitation and changes in intra-annual precipitation pattern have the potential to slightly increase carrying capacities of the system. In contrast, decreased precipitation, higher interannual variation and temperature increase are leading to a severe decline of carrying capacities owing to losses of the perennial grass biomass. 4. Semi-arid rangelands will be at lower risk of shrub encroachment and encroachment will be less intense under future climatic conditions. This finding holds in spite of elevated levels of atmospheric CO 2 and irrespective of changes in precipitation pattern, because of the drought sensitivity of germination and establishment of encroaching species. 5. Synthesis and applications. Changes in livestock carrying capacities, both positive and negative, mainly depend on the highly uncertain future rainfall conditions. However, independent of the specific changes, shrub encroachment becomes less likely and in many cases less severe. Thus, managers of semi-arid rangelands should shift their focus from woody vegetation towards perennial grass species as indicators for rangeland degradation. Furthermore, the resulting reduced competition from woody vegetation has the potential to facilitate ecosystem restoration measures such as re-introduction of desirable plant species that are only little promising or infeasible under current climatic conditions. On a global scale, the reductions in standing biomass resulting from altered degradation dynamics of semi-arid rangelands can have negative impacts on carbon sequestration.

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Introduction: Molecules targeting programmed cell death 1 or its ligand programmed death ligand 1 (PD-L1) revolutionized the treatment of patients with NSCLC. The only approved biomarker for predicting treatment response is the PD-L1 tumor proportion score (TPS) determined by immunohistochemistry. According to International Association for the Study of Lung Cancer recommendations, specimens that include fewer than 100 tumor cells or are older than 3 years should not be used for PD-L1 testing and the reliability of cell blocks has yet to be validated. Methods: This retrospective study included 1249 consecutive patients with NSCLC who were tested for PD-L1 (using the clone 22C3) between September 2016 and April 2017. The associations between the presence of suboptimal characteristics (specimens with <100 tumor cells, specimens older than 3 years, or cell blocks) and PD-L1 TPS were examined by using a multinomial logistic regression. Results: Specimens from 35.5% of the patients had at least one suboptimal characteristic. For patients with a PD-L1 TPS of higher than 50%, there was a significantly higher probability that they had a specimen with more than 100 tumor cells (OR ¼ 1.97, p ¼ 0.008) and a more recent block (within 30 days versus after >3 years) (OR ¼ 2.46, p ¼ 0.023). There was no statistical difference in PD-L1 TPS between cell blocks and tissue specimens (biopsy OR ¼ 0.99 [p ¼ 0.996] and surgery OR ¼ 0.73 [p ¼ 0.302]). Conclusions: Our results suggest that specimens containing fewer than 100 tumor cells or older than 3 years may lead to an underestimation of PD-L1 status. Our findings also provide support for the use of cell blocks for PD-L1 testing, although further research is needed.