Violent conflict and behavior:A field experiment in Burundi

We use a series of field experiments in rural Burundi to examine the impact of exposure to conflict on social, risk, and time preferences. We find that conflict affects behavior: individuals exposed to violence display more altruistic behavior towards their neighbors, are more risk-seeking, and have higher discount rates. Large adverse shocks can thus alter savings and investments decisions, and potentially have long-run consequences—even if the shocks themselves are temporary

Decentralised innovation systems and poverty reduction: experimental evidence from Central Africa

We use experimental data to investigate whether a decentralised approach to promoting innovation in central African agriculture outperforms conventional extension ap proaches. Our main result is that this decentralised approach, based on so-called innova tion platforms, is effective in reducing poverty – more effective than conventional extension approaches. However, we also document considerable heterogeneity in terms of platform performance

Driving pressure during general anesthesia for open abdominal surgery (DESIGNATION) : study protocol of a randomized clinical trial

Background Intraoperative driving pressure (Delta P) is associated with development of postoperative pulmonary complications (PPC). When tidal volume (V-T) is kept constant, Delta P may change according to positive end-expiratory pressure (PEEP)-induced changes in lung aeration. Delta P may decrease if PEEP leads to a recruitment of collapsed lung tissue but will increase if PEEP mainly causes pulmonary overdistension. This study tests the hypothesis that individualized high PEEP, when compared to fixed low PEEP, protects against PPC in patients undergoing open abdominal surgery. Methods The "Driving prESsure durIng GeNeral AnesThesIa for Open abdomiNal surgery trial" (DESIGNATION) is an international, multicenter, two-group, double-blind randomized clinical superiority trial. A total of 1468 patients will be randomly assigned to one of the two intraoperative ventilation strategies. Investigators screen patients aged >= 18 years and with a body mass index <= 40 kg/m(2), scheduled for open abdominal surgery and at risk for PPC. Patients either receive an intraoperative ventilation strategy with individualized high PEEP with recruitment maneuvers (RM) ("individualized high PEEP") or one in which PEEP of 5 cm H2O without RM is used ("low PEEP"). In the "individualized high PEEP" group, PEEP is set at the level at which Delta P is lowest. In both groups of the trial, V-T is kept at 8 mL/kg predicted body weight. The primary endpoint is the occurrence of PPC, recorded as a collapsed composite of adverse pulmonary events. Discussion DESIGNATION will be the first randomized clinical trial that is adequately powered to compare the effects of individualized high PEEP with RM versus fixed low PEEP without RM on the occurrence of PPC after open abdominal surgery. The results of DESIGNATION will support anesthesiologists in their decisions regarding PEEP settings during open abdominal surgery

Rat model of metastatic breast cancer monitored by MRI at 3 tesla and bioluminescence imaging with histological correlation

<p>Abstract</p> <p>Background</p> <p>Establishing a large rodent model of brain metastasis that can be monitored using clinically relevant magnetic resonance imaging (MRI) techniques is challenging. Non-invasive imaging of brain metastasis in mice usually requires high field strength MR units and long imaging acquisition times. Using the brain seeking MDA-MB-231BR transfected with luciferase gene, a metastatic breast cancer brain tumor model was investigated in the nude rat. Serial MRI and bioluminescence imaging (BLI) was performed and findings were correlated with histology. Results demonstrated the utility of multimodality imaging in identifying unexpected sights of metastasis and monitoring the progression of disease in the nude rat.</p> <p>Methods</p> <p>Brain seeking breast cancer cells MDA-MB-231BR transfected with firefly luciferase (231BRL) were labeled with ferumoxides-protamine sulfate (FEPro) and 1-3 × 10⁶cells were intracardiac (IC) injected. MRI and BLI were performed up to 4 weeks to monitor the early breast cancer cell infiltration into the brain and formation of metastases. Rats were euthanized at different time points and the imaging findings were correlated with histological analysis to validate the presence of metastases in tissues.</p> <p>Results</p> <p>Early metastasis of the FEPro labeled 231BRL were demonstrated onT2*-weighted MRI and BLI within 1 week post IC injection of cells. Micro-metastatic tumors were detected in the brain on T2-weighted MRI as early as 2 weeks post-injection in greater than 85% of rats. Unexpected skeletal metastases from the 231BRL cells were demonstrated and validated by multimodal imaging. Brain metastases were clearly visible on T2 weighted MRI by 3-4 weeks post infusion of 231BRL cells, however BLI did not demonstrate photon flux activity originating from the brain in all animals due to scattering of the photons from tumors.</p> <p>Conclusion</p> <p>A model of metastatic breast cancer in the nude rat was successfully developed and evaluated using multimodal imaging including MRI and BLI providing the ability to study the temporal and spatial distribution of metastases in the brain and skeleton.</p

Instability of Democracy as Resource Curse

We suggest a dynamic game theoretic model to explain why resource abundance may lead to instability of democracy. Stationary Markov perfect equilibria of this game with four players – Politician, Oligarch, Autocrat and Public (voters) – are analyzed. Choosing a rate of resource rent tax, potential Autocrat competes with conventional Politician for the office, and Oligarch, the owner of the resource wealth, bribes Politician to influence her decisions. Actual Autocrat's tax policy may be different from the announced one. If the difference is large, then Public may revolt or Oligarch may organize a coup to throw Autocrat down. It is shown that the probability of democracy preservation is decreasing in the amount of resources if the institutional quality is low enough. It does not depend on the amount of resources, if the institutional quality is higher than a threshold. The level of the threshold, however, depends positively on the resource wealth. We have found also that under very low institutional quality, a paradoxical effect takes place: the probability of democracy preservation may decrease with small improvements of institutional quality. It is shown as well that Oligarch earns larger part of rent under democracy than under autocracy. This result conforms to empirical observation which is demonstrated in the paper: under low quality of institutions, democratization leads to higher inequality and inequality entails worsening of the attitude to democracy

Accelerated stem cell labeling with ferucarbotran and protamine

To develop and characterize a clinically applicable, fast and efficient method for stem cell labeling with ferucarbotran and protamine for depiction with clinical MRI. The hydrodynamic diameter, zeta potential and relaxivities of ferucarbotran and varying concentrations of protamine were measured. Once the optimized ratio was found, human mesenchymal stem cells (MSCs) were labeled at varying incubation times (1–24 h). Viability was assessed via Trypan blue exclusion testing. 150,000 labeled cells in Ficoll solution were imaged with T1-, T2- and T2*-weighted sequences at 3 T, and relaxation rates were calculated. Varying the concentrations of protamine allows for easy modification of the physicochemical properties. Simple incubation with ferucarbotran alone resulted in efficient labeling after 24 h of incubation while assisted labeling with protamine resulted in similar results after only 1 h. Cell viability remained unaffected. R2 and R2* relaxation rates were drastically increased. Electron microscopy confirmed intracellular iron oxide uptake in lysosomes. Relaxation times correlated with results from ICP-AES. Our results show internalization of ferucarbotran can be accelerated in MSCs with protamine, an approved heparin antagonist and potentially clinically applicable uptake-enhancing agent

Seasonal particulate organic carbon dynamics of the Kolyma River tributaries, Siberia

Arctic warming is causing permafrost thaw and release of organic carbon (OC) to fluvial systems. Permafrost-derived OC can be transported downstream and degraded into greenhouse gases that may enhance climate warming. Susceptibility of OC to decomposition depends largely upon its source and composition, which vary throughout the seasonally distinct hydrograph. Most studies on carbon dynamics to date have focused on larger Arctic rivers, yet little is known about carbon cycling in lower-order rivers and streams. Here, we characterize the composition and sources of OC, focusing on less studied particulate OC (POC), in smaller waterways within the Kolyma River watershed. Additionally, we examine how watershed characteristics control carbon concentrations. In lower-order systems, we find rapid initiation of primary production in response to warm water temperatures during spring freshet, shown by decreasing δ13C-POC, in contrast to larger rivers. This results in CO2 uptake by primary producers and microbial degradation of mainly autochthonous OC. However, if terrestrially derived inorganic carbon is assimilated by primary producers, part of it is returned via CO2 emissions if the autochthonous OC pool is simultaneously degraded. As Arctic warming and hydrologic changes may increase OC transfer from smaller waterways to larger river networks, understanding carbon dynamics in smaller waterways is crucial.</p