Tropical Peatland Hydrology Simulated With a Global Land Surface Model.

Tropical peatlands are among the most carbon-dense ecosystems on Earth, and their water storage dynamics strongly control these carbon stocks. The hydrological functioning of tropical peatlands differs from that of northern peatlands, which has not yet been accounted for in global land surface models (LSMs). Here, we integrated tropical peat-specific hydrology modules into a global LSM for the first time, by utilizing the peatland-specific model structure adaptation (PEATCLSM) of the NASA Catchment Land Surface Model (CLSM). We developed literature-based parameter sets for natural (PEATCLSMTrop,Nat) and drained (PEATCLSMTrop,Drain) tropical peatlands. Simulations with PEATCLSMTrop,Nat were compared against those with the default CLSM version and the northern version of PEATCLSM (PEATCLSMNorth,Nat) with tropical vegetation input. All simulations were forced with global meteorological reanalysis input data for the major tropical peatland regions in Central and South America, the Congo Basin, and Southeast Asia. The evaluation against a unique and extensive data set of in situ water level and eddy covariance-derived evapotranspiration showed an overall improvement in bias and correlation compared to the default CLSM version. Over Southeast Asia, an additional simulation with PEATCLSMTrop,Drain was run to address the large fraction of drained tropical peatlands in this region. PEATCLSMTrop,Drain outperformed CLSM, PEATCLSMNorth,Nat, and PEATCLSMTrop,Nat over drained sites. Despite the overall improvements of PEATCLSMTrop,Nat over CLSM, there are strong differences in performance between the three study regions. We attribute these performance differences to regional differences in accuracy of meteorological forcing data, and differences in peatland hydrologic response that are not yet captured by our model.

Calcification Volume Reduces Stretch Capability and Predisposes Plaque to Rupture in an in vitro Model of Carotid Artery Stenting.

OBJECTIVE/BACKGROUND: Carotid artery stenting (CAS) in calcified arteries carries a higher peri-operative risk. This study investigates the relationship between the stretching limits of carotid plaque samples and calcification in order to determine a stretch tolerance criterion for endovascular intervention. METHODS: Seventeen carotid plaque samples were acquired from standard endarterectomy procedures. The maximum stretch capability of the global plaque was determined by circumferentially extending the tissue to complete failure. Quantitative assessment of calcification was performed using high resolution computed tomography, including measures of percent calcification volume fraction (%CVF) and calcification configuration. Maximum stretch properties were then related to calcification measures in order to evaluate the predictive power of calcification for determining plaque stretching limits. RESULTS: A strong negative correlation was found between %CVF and stretch ratio with respect to specific calcification configuration types. All plaques with < 70% stenosis superseded the minimum required stretch threshold. Severe stenosis (> 70%) warrants a stretch of at least 2.33 during revascularisation and only plaques containing concentric calcifications with < 20% CVF successfully reached this minimum required stretch threshold. CONCLUSION: The addition of calcification measures to the stenosis classification may help in guiding endovascular intervention techniques to achieve a balance between an acceptable residual patency level while avoiding plaque rupture in calcified carotid plaques.

Minimal Invasive Plate Osteosynthesis (MIPO) Technique Using Anterolateral Approach for Treating Closed Proximal Humerus Fracture.

ABSTRACT: Proximal humerus fracture is the second most common fracture of the upper extremity and presents several unique problems such as anatomical complexity, high risk of avascular necrosis, minimal bone stock for purchase, significant morbidity, and lack of a universally accepted treatment. Recent treatments for proximal humerus fractures include use of minimally invasive plate osteosynthysis (MIPO). The aim of this cross-sectional study was to evaluate the outcomes of our less invasive technique using a modified anterolateral approach for treatment of proximal humerus fractures. Ten such operative procedures were performed in patients of varying age and with varied mechanism of injury from 2002-2011. All cases were conducted in an acute setting. There were no cases of infection and the functional outcome scores were good. This approach represents an alternative treatment for closed proximal humerus fracture but more extensive studies are needed. KEY WORDS: Proximal humerus fracture, MIPO, less invasive,anterolateral approach.

Minimal Invasive Plate Osteosynthesis (MIPO) Technique Using Anterolateral Approach for Treating Closed Proximal Humerus Fracture

Proximal humerus fracture is the second most common fracture of the upper extremity and presents several unique problems such as anatomical complexity, high risk of avascular necrosis, minimal bone stock for purchase, significant morbidity, and lack of a universally accepted treatment. Recent treatments for proximal humerus fractures include use of minimally invasive plate osteosynthysis (MIPO). The aim of this cross-sectional study was to evaluate the outcomes of our less invasive technique using a modified anterolateral approach for treatment of proximal humerus fractures. Ten such operative procedures were performed in patients of varying age and with varied mechanism of injury from 2002-2011. All cases were conducted in an acute setting. There were no cases of infection and the functional outcome scores were good. This approach represents an alternative treatment for closed proximal humerus fracture but more extensive studies are needed.