Policy Distortions and Aggregate Productivity with Heterogeneous Plants

We formulate a version of the growth model in which production is carried out by heterogeneous plants and calibrate it to US data. In the context of this model we argue that differences in the allocation of resources across heterogeneous plants may be an important factor in accounting for cross-country differences in output per capita. In particular, we show that policies which create heterogeneity in the prices faced by individual producers can lead to sizeable decreases in output and measured TFP in the range of 30 to 50 percent. We show that these effects can result from policies that do not rely on aggregate capital accumulation or aggregate relative price differences. More generally, the model can be used to generate differences in capital accumulation, relative prices, and measured TFP.Plant heterogeneity, productivity, policy

Plane shear flows of frictionless spheres: Kinetic theory and 3D soft-sphere discrete element method simulations

We use existing 3D Discrete Element simulations of simple shear flows of spheres to evaluate the radial distribution function at contact that enables kinetic theory to correctly predict the pressure and the shear stress, for different values of the collisional coefficient of restitution. Then, we perform 3D Discrete Element simulations of plane flows of frictionless, inelastic spheres, sheared between walls made bumpy by gluing particles in a regular array, at fixed average volume fraction and distance between the walls. The results of the numerical simulations are used to derive boundary conditions appropriated in the cases of large and small bumpiness. Those boundary conditions are, then, employed to numerically integrate the differential equations of Extended Kinetic Theory, where the breaking of the molecular chaos assumption at volume fraction larger than 0.49 is taken into account in the expression of the dissipation rate. We show that the Extended Kinetic Theory is in very good agreement with the numerical simulations, even for coefficients of restitution as low as 0.50. When the bumpiness is increased, we observe that some of the flowing particles are stuck in the gaps between the wall spheres. As a consequence, the walls are more dissipative than expected, and the flows resemble simple shear flows, i.e., flows of rather constant volume fraction and granular temperature

Pegylated arginine deiminase synergistically increases the cytotoxicity of gemcitabine in human pancreatic cancer.

BackgroundPancreatic ductal adenocarcinoma has proven to be one of the most chemo-resistant among all solid organ malignancies. Several mechanisms of resistance have been described, though few reports of strategies to overcome this chemo-resistance have been successful in restoring sensitivity to the primary chemotherapy (gemcitabine) and enter the clinical treatment arena.MethodsWe examined the ability of cellular arginine depletion through treatment with PEG-ADI to alter in vitro and in vivo cytotoxicity of gemcitabine. The effect on levels of key regulators of gemcitabine efficacy (e.g. RRM2, hENT1, and dCK) were examined.ResultsCombination of PEG-ADI and gemcitabine substantially increases growth arrest, leading to increased tumor response in vivo. PEG-ADI is a strong inhibitor of the gemcitabine-induced overexpression of ribonucleotide reductase subunit M2 (RRM2) levels both in vivo and in vitro, which is associated with gemcitabine resistance. This mechanism is through the abrogation of the gemcitabine-mediated inhibitory effect on E2F-1 function, a transcriptional repressor of RRM2.ConclusionThe ability to alter gemcitabine resistance in a targeted manner by inducing metabolic stress holds great promise in the treatment of advanced pancreatic cancer

GLEAM v3 : satellite-based land evaporation and root-zone soil moisture

The Global Land Evaporation Amsterdam Model (GLEAM) is a set of algorithms dedicated to the estimation of terrestrial evaporation and root-zone soil moisture from satellite data. Ever since its development in 2011, the model has been regularly revised, aiming at the optimal incorporation of new satellite-observed geophysical variables, and improving the representation of physical processes. In this study, the next version of this model (v3) is presented. Key changes relative to the previous version include (1) a revised formulation of the evaporative stress, (2) an optimized drainage algorithm, and (3) a new soil moisture data assimilation system. GLEAM v3 is used to produce three new data sets of terrestrial evaporation and root-zone soil moisture, including a 36-year data set spanning 1980-2015, referred to as v3a (based on satellite-observed soil moisture, vegetation optical depth and snow-water equivalent, reanalysis air temperature and radiation, and a multi-source precipitation product), and two satellite-based data sets. The latter share most of their forcing, except for the vegetation optical depth and soil moisture, which are based on observations from different passive and active C-and L-band microwave sensors (European Space Agency Climate Change Initiative, ESA CCI) for the v3b data set (spanning 2003-2015) and observations from the Soil Moisture and Ocean Salinity (SMOS) satellite in the v3c data set (spanning 2011-2015). Here, these three data sets are described in detail, compared against analogous data sets generated using the previous version of GLEAM (v2), and validated against measurements from 91 eddy-covariance towers and 2325 soil moisture sensors across a broad range of ecosystems. Results indicate that the quality of the v3 soil moisture is consistently better than the one from v2: average correlations against in situ surface soil moisture measurements increase from 0.61 to 0.64 in the case of the v3a data set and the representation of soil moisture in the second layer improves as well, with correlations increasing from 0.47 to 0.53. Similar improvements are observed for the v3b and c data sets. Despite regional differences, the quality of the evaporation fluxes remains overall similar to the one obtained using the previous version of GLEAM, with average correlations against eddy-covariance measurements ranging between 0.78 and 0.81 for the different data sets. These global data sets of terrestrial evaporation and root-zone soil moisture are now openly available at www.GLEAM.eu and may be used for large-scale hydrological applications, climate studies, or research on land-atmosphere feedbacks

Ab initio LSDA and LSDA+U study of pure and Cd-doped cubic lanthanide sesquioxides

The electronic, structural, and hyperfine properties of pure and Cd-doped lanthanide (Ln) sesquioxides with the cubic bixbyite structure (Ln2O3, Ln ranging from La to Lu) have been studied using the full-potential augmented plane wave plus local orbital (APW + lo) method within the local spin density approximation (LSDA) and the Coulomb-corrected LSDA + U. In the case of the pure systems, our calculations show that LSDA + U gives a better representation of the band structure compared to LSDA. The predicted equilibrium structures and the electric field gradient (EFG) tensor at Ln sites were calculated and compared with those obtained by means of hyperfine techniques and with theoretical results obtained in In2O3, Sc2O3, and Lu2O3 reported in the literature. The origin of the EFG at Ln sites and the role played by the 4f electrons on this quantity are discussed. In the case of the Cd-doped systems, the APW + lo method (also within LSDA and LSDA + U) was applied to treat the electronic structure of the doped system. The role of the Ln 4f electrons on the EFG at Cd impurity sites, and other variables like structural distortions induced by the Cd impurity, were investigated in detail and are discussed and compared with available experimental results. An excellent agreement between the experimental and calculated EFGs was found for all Cd-doped systems.Fil: Richard, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Muñoz, Emiliano Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Rentería, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Errico, Leonardo Antonio. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Svane, A.. University Aarhus. Institut for Fysik Og Astronomi; DinamarcaFil: Christensen, N. E.. University Aarhus. Institut for Fysik Og Astronomi; Dinamarc

Climate Change Policy: The Waxman-Markey Bill

The Waxman-Markey Bill is a comprehensive national climate and energy legislation designed to reduce global warming pollution and transition to a clean energy economy. In order to accomplish the first goal, the bill introduces a cap-and-trade program

Local Environments in Iron-Bearing Clay Minerals by DFT Approaches: The Case of Structural Fe in Kaolinite

Technological properties of kaolins depend on the internal structure of the particles that constitute them. For this reason, unraveling the structural features from the micro to the nanoscale is a permanent matter of interest, even in the case of raw samples. From the experimental point of view, because naturally-occurring kaolins contain iron, Mössbauer spectroscopy is a very convenient technique to reach the nanoscopic scale avoiding experimental difficulties related to the sample's lack of structural order at the crystallographic scale. In this work, first-principles calculations based on the Density Functional Theory (DFT) were used to model such iron environments in kaolinite, and to assess the performance of the Gauge-Included Projector Augmented Waves (GIPAW) method to describe the changes to the host structure and the electronic modifications produced by the iron atoms. To this purpose, structural relaxation, Grimme's D2 dispersion, and Hubbard corrections (DFT+U approach) were considered. A detailed analysis was done for the obtained predictions for the Fe local structure, oxidation state, and Mössbauer quadrupole splitting, including comparisons with available experimental data. The results contribute to better understand the naturally-occurring kaolins, and support the DFT+U approach for the description of the layer structure and the electronic properties of iron-containing clay minerals.Fil: Richard, Diego. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Rendtorff Birrer, Nicolás Maximiliano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin

DNA methylation-based age prediction and telomere length in white blood cells and cumulus cells of infertile women with normal or poor response to ovarian stimulation.

An algorithm assessing the methylation levels of 353 informative CpG sites in the human genome permits accurate prediction of the chronologic age of a subject. Interestingly, when there is discrepancy between the predicted age and chronologic age (age acceleration or AgeAccel ), patients are at risk for morbidity and mortality. Identification of infertile patients at risk for accelerated reproductive senescence may permit preventative action. This study aimed to assess the accuracy of the epigenetic clock concept in reproductive age women undergoing fertility treatment by applying the age prediction algorithm in peripheral (white blood cells [WBCs]) and follicular somatic cells (cumulus cells [CCs]), and to identify whether women with premature reproductive aging (diminished ovarian reserve) were at risk of AgeAccel in their age prediction. Results indicated that the epigenetic algorithm accurately predicts age when applied to WBCs but not to CCs. The age prediction of CCs was substantially younger than chronologic age regardless of the patient\u27s age or response to stimulation. In addition, telomeres of CCs were significantly longer than that of WBCs. Our findings suggest that CCs do not demonstrate changes in methylome-predicted age or telomere-length in association with increasing female age or ovarian response to stimulation

Experimental and ab initio study of the structural and optical properties of ZnO coatings: Performance of the DFT+U approach

In this work, ZnO coatings were produced by the spray-pyrolysis technique and characterized by scanning electron microscopy, X-ray diffraction and optical transmittance spectroscopy. The experimental results were compared to predictions obtained from electronic-structure calculations based on the Density Functional Theory plus U (DFT+U) approach. To this purpose, the 2H, 4H and 6H polytypes of ZnO were theoretically analysed, and DFT+U was assessed for the calculation of structural, electronic and optical properties of the hexagonal ZnO structures. We found that DFT+U is an effective and accurate method that combined with experimental measurements, allows a deeper insight about the coatings of the wurtzite (2H) phase synthesized in the laboratory. This comprehensive study of the pure ZnO is the first step towards the study of more complex ZnO-based coatings.Fil: Apaolaza, Agustín. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Richard, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; ArgentinaFil: Tejerina, Matías Rubén. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentin