Individual cheating in the lab: a new measure and external validity

This paper investigates to what extent laboratory measures of cheating generalise to the field. To this purpose, we develop a lab measure that allows for individual-level observations of cheating whilst reducing the likelihood that participants feel observed. Decisions made in this laboratory task are then compared to individual choices taken in the field, where subjects can lie by misreporting their experimental earnings. We use two field variations that differ in the degree of anonymity of the field decision. According to our measure, no correlation of behaviour between the laboratory and the field is found. We then perform the same analysis using a lab measure that can only detect cheating at the aggregate level. In this case, we do find a weak correlation between the two environments. We discuss the significance and interpretation of these results

Il trapianto nei pazienti HCV+: esperienza di Modena

Abstract non disponibil

Implementing the Simple Biosphere Model (SiB) in a general circulation model: Methodologies and results

The Simple Biosphere MOdel (SiB) of Sellers et al., (1986) was designed to simulate the interactions between the Earth's land surface and the atmosphere by treating the vegetation explicitly and relistically, thereby incorporating biophysical controls on the exchanges of radiation, momentum, sensible and latent heat between the two systems. The steps taken to implement SiB in a modified version of the National Meteorological Center's spectral GCM are described. The coupled model (SiB-GCM) was used with a conventional hydrological model (Ctl-GCM) to produce summer and winter simulations. The same GCM was used with a conventional hydrological model (Ctl-GCM) to produce comparable 'control' summer and winter variations. It was found that SiB-GCM produced a more realistic partitioning of energy at the land surface than Ctl-GCM. Generally, SiB-GCM produced more sensible heat flux and less latent heat flux over vegetated land than did Ctl-GCM and this resulted in the development of a much deeper daytime planetary boundary and reduced precipitation rates over the continents in SiB-GCM. In the summer simulation, the 200 mb jet stream and the wind speed at 850 mb were slightly weakened in the SiB-GCM relative to the Ctl-GCM results and equivalent analyses from observations

Influence of distributary channels on sediment and organic matter supply in event-dominated coastal margins: the Po prodelta as a study case

From November 2008 through May 2009, the Po river (Italy) experienced several floods exceeding 5000 m<sup>3</sup> s<sup>−1</sup>. This long series of events ended with a large flood in early May 2009 (~8000 m<sup>3</sup> s<sup>−1</sup>). An event-response sampling was carried out in the Po prodelta in April–May 2009 to characterize the preservation of this series of floods in the sediment record and to describe the event-supply and deposition of riverborne particulate material during the May 2009 flood. The water sampling was carried out early in the event under conditions of moderate river flow (~5000 m<sup>3</sup> s<sup>−1</sup>) and 24 h later during the peak discharge (~8000 m<sup>3</sup> s<sup>−1</sup>). Sediment cores were collected in the prodelta before and after the peak flood. At each station, profiles of conductivity, transmittance, and fluorescence were acquired. Surface and bottom waters were sampled to collect sediments in suspension. In addition, a few days before the May 2009 event, suspended sediments were collected at Pontelagoscuro gauging station, ~90 km upstream from the coast. Biogeochemical compositions and sedimentological characteristics of suspended and sediment samples were investigated using bulk and biomarker analyses. Furthermore, <sup>7</sup>Be and radiographs were used to analyze the internal stratigraphy of sediment cores. <br><br> During moderate flow, the water column did not show evidence of plume penetration. Stations re-occupied 24 h later exhibited marked physical and biogeochemical changes during the peak flood. However, the concentration of terrestrially-derived material in surface waters was still less than expected. These results suggested that, since material enters the Adriatic as buoyancy-driven flow with a reduced transport capacity, settling and flocculation processes result in trapping a significant fraction of land-derived material in shallow sediments and/or within distributary channels. <br><br> Although numerous discharge peaks occurred from November 2008 through April 2009 (4000–6000 m<sup>3</sup> s<sup>−1</sup>), sediment cores collected in late April 2009 showed lack of event-strata preservation and reduced <sup>7</sup>Be penetrations. This suggested that only a small fraction of the sediment supply during ordinary events reaches the deepest region of the prodelta (12–20 m water depth). As a result, these event-strata have a thickness not sufficient to be preserved in the sediment record because of post-depositional processes that destroy the flood signal. <br><br> Stations in the northern and central prodelta were re-occupied after the peak of the May 2009 flood. Based on <sup>7</sup>Be and radiographs, we estimated event layers of 17 and 6 cm thickness, respectively. Selective trapping of coarse material occurred in the central prodelta likely because of the geomorphologic setting of the central outlet characterized by an estuary-like mouth. Despite these settling processes, lignin-based parameters indicated that the composition of the terrigenous OC was fairly homogenous throughout the network of channels and between size-fractions

Relations of power driving tropical deforestation: a case study from the Mau Forest (Kenya) = Relations de pouvoir entraînant la déforestation tropicale : une étude de cas dans la forêt Mau (Kenya)

The paper investigates the deforestation process in the Mau Forest (Kenya), highlighting the actors involved and the underlying relations of power. The proximate causes of the deforestation are three: agriculture, wood production and infrastructures. In this context of pressure on natural resources, local communities have developed different projects to reduce deforestation and promote alternative development strategies, especially through the Community Forest Associations (CFAs). These dynamics show that deforestation is a complex issue whose solutions lie primarily outside the forest itself and that it should be tackled with suitable policies on crucial issues such as land, agriculture, infrastructure and indigenous peoples.L\u2019article analyse le processus de d\ue9forestation dans la For\ueat Mau (Kenya) et met l\u2019accent sur les acteurs impliqu\ue9s et les relations de pouvoir sous-jacentes. Les causes directes de la d\ue9forestation sont trois : l'agriculture, la production de bois et les infrastructures. Dans ce contexte de pression sur les ressources naturelles, les communaut\ue9s locales ont d\ue9velopp\ue9 diff\ue9rents projets visant \ue0 r\ue9duire la d\ue9forestation et \ue0 promouvoir des strat\ue9gies de d\ue9veloppement alternatives, en particulier \ue0 travers l\u2019action des Associations Communautaires de gestion de la For\ueat (CFAs). Ces dynamiques montrent que la d\ue9forestation est une question complexe dont les solutions se situent principalement en dehors de la for\ueat et devraient \ueatre abord\ue9es \ue0 travers des politiques appropri\ue9es sur des questions cruciales telles que la terre, l'agriculture, les infrastructures et les peuples autochtones

Effect of H-Bonding on Order Amplification in the Growth of a Supramolecular Polymer in Water

While a great deal of knowledge on the roles of hydrogen bonding and hydrophobicity in proteins has resulted in the creation of rationally designed and functional peptidic structures, the roles of these forces on purely synthetic supramolecular architectures in water have proven difficult to ascertain. Focusing on a 1,3,5-benzenetricarboxamide (BTA)-based supramolecular polymer, we have designed a molecular modeling strategy to dissect the energetic contributions involved in the self-assembly (electrostatic, hydrophobic, etc.) upon growth of both ordered BTA stacks and random BTA aggregates. Utilizing this set of simulations, we have unraveled the cooperative mechanism for polymer growth, where a critical size must be reached in the aggregates before emergence and amplification of order into the experimentally observed fibers. Furthermore, we have found that the formation of ordered fibers is favored over disordered aggregates solely on the basis of electrostatic interactions. Detailed analysis of the simulation data suggests that H-bonding is a major source of this stabilization energy. Experimental and computational comparison with a newly synthesized 1,3,5-benzenetricarboxyester (BTE) derivative, lacking the ability to form the H-bonding network, demonstrated that this BTE variant is also capable of fiber formation, albeit at a reduced persistence length. This work provides unambiguous evidence for the key 1D driving force of hydrogen bonding in enhancing the persistency of monomer stacking and amplifying the level of order into the growing supramolecular polymer in water. Our computational approach provides an important relationship directly linking the structure of the monomer to the structure and properties of the supramolecular polymer

A stochastic view on surface inhomogeneity of nanoparticles

The interactions between and with nanostructures can only be fully understood when the functional group distribution on their surfaces can be quantified accurately. Here we apply a combination of direct stochastic optical reconstruction microscopy (dSTORM) imaging and probabilistic modelling to analyse molecular distributions on spherical nanoparticles. The properties of individual fluorophores are assessed and incorporated into a model for the dSTORM imaging process. Using this tailored model, overcounting artefacts are greatly reduced and the locations of dye labels can be accurately estimated, revealing their spatial distribution. We show that standard chemical protocols for dye attachment lead to inhomogeneous functionalization in the case of ubiquitous polystyrene nanoparticles. Moreover, we demonstrate that stochastic fluctuations result in large variability of the local group density between particles. These results cast doubt on the uniform surface coverage commonly assumed in the creation of amorphous functional nanoparticles and expose a striking difference between the average population and individual nanoparticle coverage

ORIGINAL COMMUNICATION Accuracy of eight-polar bioelectrical impedance analysis for the assessment of total and appendicular body composition in peritoneal dialysis patients

Objective: To establish the accuracy of bioelectrical impedance analysis (BIA) for the assessment of total and appendicular body composition in peritoneal dialysis (PD) patients. Design: Cross-sectional study. Setting: University Nephrology Clinic. Subjects: In all, 20 PD patients and 77 healthy controls matched for gender, age and body mass index. Methods: Whole-body fat-free mass (FFM) and appendicular lean tissue mass (LTM) were measured by dual-energy X-ray absorptiometry. Resistance (R) of arms, trunk and legs was measured by eight-polar BIA at frequencies of 5, 50, 250 and 500 kHz. Whole-body resistance was calculated as the sum of R of arms, trunk and legs. The resistance index (RI) was calculated as the ratio between squared height and whole-body or segmental R. Results: RI at 500 kHz was the best predictor of FFM, LTM arm and LTM leg in both PD patients and controls. Equations developed on controls overestimated FFM and LTM arm and underestimated LTM leg when applied to PD patients. Specific equations were thus developed for PD patients. Using these equations, the percent root mean-squared errors of the estimate for PD patients vs controls were 5 vs 6% for FFM, 8 vs 8% for LTM arm and 7 vs 8% for LTM leg . Conclusion: Eight-polar BIA offers accurate estimates of total and appendicular body composition in PD patients, provided that population-specific equations are used. Sponsorship: University of Modena and Reggio Emilia

The physics, dosimetry and microdosimetry of boron neutron capture therapy

A validated experimental and numerical procedure is described detailing macroscopic and microscopic dose calculations forming the basis of a protocol for the pre-clinical biological characterisation of the University of Birmingham’s BNCT facility. Fundamental reference dosimetric measurements have been carried out at the University of Birmingham’s accelerator based NCT facility and the Massachusetts Institute of Technology (MIT) research reactor to characterise macroscopic and microscopic doses and derive correction factors for the irradiation of V79 cells incubated in boric acid and irradiated as monolayers. On and off-axis thermal neutron, fast neutron and photon doses have been measured and calculated with standard macroscopic dosimetry techniques (foils and ion chambers) from which normalised MCNPX calculations are used to derive perturbation factors and off-axis corrections for cell flask irradiations. Microdosimetric correction factors are calculated for the boron dose component using Monte Carlo methods to simulate lithium ion and alpha particle tracks in semi-stochastic geometries representative of cell monolayer irradiations, incubated in a medium with 50ppm boric acid. Further simulations of recoil protons from nitrogen capture reactions allow for the calculation of correction factors for the non-uniform distribution of the nitrogen dose at the cellular level.EThOS - Electronic Theses Online ServiceGBUnited Kingdo