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The nutritional status of plant canopies in terms of nutrients (C, N, P, K, Ca, Mg, Mn, Fe, Cu, Zn) exerts a strong influence on the carbon cycle and energy balance of terrestrial ecosystems. Therefore, in order to account for the spatial and temporal variations in nutritional status of the plant species composing the canopy, we detail the methodology applied to achieve consistent time-series of leaf mass to area ratio and nutrient content of the foliage within the footprint of the Integrated Carbon Observation System Ecosystem stations. The guidelines and defi-nitions apply to most terrestrial ecosystems.

In specimens obtained from resected pancreata, the intratumoral microvessel density (IMD), the proliferation rate of the neoplastic parenchymal cells, and their p53 protein expression were assessed. The sources of errors were great in the measurements of the IMD. This statement can be illustrated by the finding that when the IMD was calculated by manual counting in five areas of intense neovascularization (hot spot regions), using x200 and x400 magnifications, the numbers of microvessels per square millimeter were 65+/-23 and 106+/-8, respectively, which reflects a significant difference. Two patterns of microvessel distribution could be identified: one with hot spots only in the stroma (n = 19) and one in which the hot spots were located in areas of neoplastic parenchyma (including its stroma) (n = 26). The IMD was significantly greater in the latter group. There was no general correlation of neoplastic disease with the IMD. However, when a scoring system was used to assess the angiogenesis, hot spots in areas of neoplastic parenchyma were associated with a greater proliferation rate of the tumor cells, and with a short length of survival of the patients from their neoplastic disease.

Rising atmospheric concentrations of CO2 (Ca) can reduce stomatal conductance and transpiration rate in trees, but the magnitude of this effect varies considerably among experiments. The theory of optimal stomatal behaviour predicts that the ratio of photosynthesis to transpiration (instantaneous transpiration efficiency, ITE) should increase in proportion to Ca. We hypothesized that plants regulate stomatal conductance optimally in response to rising Ca. We tested this hypothesis with data from young Eucalyptus saligna Sm. trees grown in 12 climate-controlled whole-tree chambers for 2 years at ambient and elevated Ca. Elevated Ca was ambient + 240 ppm, 60% higher than ambient Ca. Leaf-scale gas exchange was measured throughout the second year of the study and leaf-scale ITE increased by 60% under elevated Ca, as predicted. Values of leaf-scale ITE depended strongly on vapour pressure deficit (D) in both CO2 treatments. Whole-canopy CO2 and H2O fluxes were also monitored continuously for each chamber throughout the second year. There were small differences in D between Ca treatments, which had important effects on values of canopy-scale ITE. However, when Ca treatments were compared at the same D, canopy-scale ITE was consistently increased by 60%, again as predicted. Importantly, leaf and canopy-scale ITE were not significantly different, indicating that ITE was not scale-dependent. Observed changes in transpiration rate could be explained on the basis that ITE increased in proportion to Ca. The effect of elevated Ca on photosynthesis increased with rising D. At high D, Ca had a large effect on photosynthesis and a small effect on transpiration rate. At low D, in contrast, there was a small effect of Ca on photosynthesis, but a much larger effect on transpiration rate. If shown to be a general response, the proportionality of ITE with Ca will allow us to predict the effects of Ca on transpiration rate.

Elevated atmospheric [CO 2] (eCa) often decreases stomatal conductance, which may delay the start of drought, as well as alleviate the effect of dry soil on plant water use and carbon uptake. We studied the interaction between drought and eCa in a whole-tree chamber experiment with Eucalyptus saligna. Trees were grown for 18 months in their Ca treatments before a 4-month dry-down. Trees grown in eCa were smaller than those grown in ambient Ca (aCa) due to an early growth setback that was maintained throughout the duration of the experiment. Pre-dawn leaf water potentials were not different between Ca treatments, but were lower in the drought treatment than the irrigated control. Counter to expectations, the drought treatment caused a larger reduction in canopy-average transpiration rates for trees in the eCa treatment compared with aCa. Total tree transpiration over the dry-down was positively correlated with the decrease in soil water storage, measured in the top 1.5 m, over the drying cycle; however, we could not close the water budget especially for the larger trees, suggesting soil water uptake below 1.5 m depth. Using neutron probe soil water measurements, we estimated fractional water uptake to a depth of 4.5 m and found that larger trees were able to extract more water from deep soil layers. These results highlight the interaction between rooting depth and response of tree water use to drought. The responses of tree water use to eCa involve interactions between tree size, root distribution and soil moisture availability that may override the expected direct effects of eCa. It is essential that these interactions be considered when interpreting experimental results. © 2011 The Author. Published by Oxford University Press. A ll rights reserved.

Context Resection of the body and tail of the pancreas (distal pancreatectomy) is associated with high postoperative morbidity, most of which is due to leakage from the pancreatic transection surface. Objective The aim of the current study was to analyze factors which may affect the risk of pancreatic fistula formation. Patients All consecutive distal pancreatectomies prospectively registered in our hospital database from 1999 to 2007 were included. Clinically relevant pancreatic fistula grades B and C, defined according to the International Study Group on Pancreatic Fistula (ISGPF) definition were assessed. Main outcome measures The impact of patient, tumor, surgery, and radiology-related factors on the risk of pancreatic fistula formation were assessed by univariate and multivariate analyses. Results A distal pancreatectomy was performed in 51 patients (median age: 59 years; range: 26-76 years), 22 of whom had malignant and 29 benign or premalignant disease. Pancreatic fistulas were diagnosed in 17 (33.3%) of the patients. An additional three patients had a local abscess without apparent but assumed pancreatic leakage. Multivariate analysis showed that pancreatic fistulas occurred more frequently after hand suturing of the transection area versus the use of a stapler (69.2% vs. 21.1%; OR: 40.4, 95% CI: 3.36-486; P=0.004) and a large volume of the pancreatic remnant (greater, or equal to, 34 cm3) increased the subsequent risk of pancreatic fistula (57.1% vs. 20.8%; OR: 6.14, 95% CI: 1.14-39.0; P=0.035). Conclusions Development of pancreatic fistula after distal pancreatectomy remains a challenge. The volume of the remaining pancreas and the technique of closure of the transected pancreas were found to affect this risk, thus allowing future preventive measures to be explored and evaluated in clinical trials. Image: 3D volume rendering image of the pancreas with the remaining pancreas shown in blue., JOP. Journal of the Pancreas, Vol 11, No 5 (2010): September - 423-497

Resolving ecophysiological processes in elevated atmospheric CO2 (Ca) at scales larger than single leaves poses significant challenges. Here, we describe a field-based experimental system designed to grow trees up to 9m tall in elevated Ca with the capacity to control air temperature and simultaneously measure whole-tree gas exchange. In western Sydney, Australia, we established the Hawkesbury Forest Experiment (HFE) where we built whole-tree chambers (WTC) to measure whole-tree CO2 and water fluxes of an evergreen broadleaf tree, Eucalyptus saligna. A single E. saligna tree was grown from seedling to small tree within each of 12 WTCs; six WTCs were maintained at ambient Ca and six WTCs were maintained at elevated Ca, targeted at ambient Ca +240μmolmol-1. All 12 WTCs were controlled to track ambient outside air temperature (Tair) and air water vapour deficit (Dair). During the experimental period, Tair, Dair and Ca in the WTCs were within 0.5°C, 0.3kPa, and 15μmolmol-1 of the set-points for 90% of the time, respectively. Diurnal responses of whole-tree CO2 and water vapour fluxes are analysed, demonstrating the ability of the tree chamber system to measure rapid environmental responses of these fluxes of entire trees. The light response of CO2 uptake for entire trees showed a clear diurnal hysteresis, attributed to stomatal closure at high Dair. Tree scale CO2 fluxes confirm the hypothesised deleterious effect of chilling night-time temperatures on whole-tree carbon gain in this subtropical Eucalyptus. The whole-tree chamber flux data add an invaluable scale to measurements in both ambient and elevated Ca and allow us to elucidate the mechanisms driving tree productivity responses to elevated Ca in interaction with water availability and temperature. © 2010 Elsevier B.V.