Long term evolution of tree growth, understorey vegetation and soil properties in a silvopastoral system of northern Greece

Tree growth, understorey characteristics and soil parameters were evaluated in a silvopastoral system in northern Greece at seven and twelve years after its establishment. The experiment was laid out in 1992 and included three understorey treatments (grass, legume and control- unsown), two tree species - sycamore (Acer pseudoplatanus L.) and Scots pine (Pinus sylvestris L.) and two tree spacings (2.5 x 2.5 m and 3.5 x 3.5 m). Tree height was taller in the control and in the dense stands while Scots pine had better growth but, higher mortality than sycamore in the both periods. In 2004, understorey vegetation was uniform under the three understorey treatments and a significant decrease in sward above ground biomass was recorded under the dense treatment, compared with the open stand. In the same year, organic C and N, Mg and K concentrations as well as arbuscular mycorrhizal fungi spore numbers were found significantly higher under sycamore than Scots pine plots in the 0-20 cm soil depth. The results show that, although understorey vegetation became uniform over time, the initial plant composition of the understorey treatments continued to affect tree growth, indicating the importance of the understorey vegetation at the establishment stage of silvopastoral systems. However, as time passed initial tree spacing started to affect tree growth and tree species, particularly sycamore to improve soil properties. These results indicate an evolution of the initial silvopastoral system to a forest.</p

Remote Ischemic Preconditioning May Attenuate Renal Ischemia-Reperfusion Injury in a Porcine Model of Supraceliac Aortic Cross-Clamping

Aim: The effect of remote ischemic preconditioning (RIPC) in decreasing renal ischemia-reperfusion injury (IRI) during a suprarenal aortic cross-clamping was examined in a swine model. Materials and Methods: Four groups of pigs were examined: (a) ischemia-reperfusion (IR) group, renal IRI produced by 30 min of supraceliac aortic cross-clamping; (b) RIPC I group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (15 min ischemia and 15 min reperfusion); (c) RIPC II group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (3 cycles of 5 min ischemia and 5 min reperfusion); (d) sham group. Renal function was assessed before and after IRI by examining creatinine, neutrophil gelatinase-associated lipocalin (NGAL), TNF-α, malondialdehyde (MDA), cystatin C and C-reactive protein (CRP) from renal vein blood samples at specific time intervals. Results: Both RIPC groups presented significantly less impaired results compared to the IR group when considering MDA, cystatin C, CRP and creatinine. Between the two RIPC groups, RIPC II presented a better response with regard to CRP, NGAL, TNF-α, MDA and cystatin C. Conclusions: Remote IR protocols and mainly repetitive short periods of cycles of IR ameliorate the biochemical kidney effects of IRI in a model of suprarenal aortic aneurysm repair. © 2015 S. Karger AG, Basel

Supplementary Material for: Remote Ischemic Preconditioning May Attenuate Renal Ischemia-Reperfusion Injury in a Porcine Model of Supraceliac Aortic Cross-Clamping

<b><i>Aim:</i></b> The effect of remote ischemic preconditioning (RIPC) in decreasing renal ischemia-reperfusion injury (IRI) during a suprarenal aortic cross-clamping was examined in a swine model. <b><i>Materials and Methods:</i></b> Four groups of pigs were examined: (a) ischemia-reperfusion (IR) group, renal IRI produced by 30 min of supraceliac aortic cross-clamping; (b) RIPC I group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (15 min ischemia and 15 min reperfusion); (c) RIPC II group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (3 cycles of 5 min ischemia and 5 min reperfusion); (d) sham group. Renal function was assessed before and after IRI by examining creatinine, neutrophil gelatinase-associated lipocalin (NGAL), TNF-α, malondialdehyde (MDA), cystatin C and C-reactive protein (CRP) from renal vein blood samples at specific time intervals. <b><i>Results:</i></b> Both RIPC groups presented significantly less impaired results compared to the IR group when considering MDA, cystatin C, CRP and creatinine. Between the two RIPC groups, RIPC II presented a better response with regard to CRP, NGAL, TNF-α, MDA and cystatin C. <b><i>Conclusions:</i></b> Remote IR protocols and mainly repetitive short periods of cycles of IR ameliorate the biochemical kidney effects of IRI in a model of suprarenal aortic aneurysm repair