Cumulative Innovation, Growth and Welfare-Improving Patent Policy

We construct a tractable general equilibrium model of cumulative innovation and growth, in which new ideas strictly improve upon frontier technologies, and productivity improvements are drawn in a stochastic manner. The presence of positive knowledge spillovers implies that the decentralized equilibrium features an allocation of labor to R&D activity that is strictly lower than the social planner's benchmark, which suggests a role for patent policy. We focus on a non-infringing inventive step requirement, which stipulates the minimum improvement to the best patented technology that a new idea needs to make for it to be patentable and non-infringing. We establish that there exists a finite required inventive step that maximizes the rate of innovation, as well as a separate optimal required inventive step that maximizes welfare, with the former being strictly greater than the latter. These conclusions are robust to allowing for the availability of an additional instrument in the form of patent length policy

Nephrotic Syndrome in Children: From Bench to Treatment

Idiopathic nephrotic syndrome (INS) is the most frequent form of NS in children. INS is defined by the association of the clinical features of NS with renal biopsy findings of minimal changes, focal segmental glomerulosclerosis (FSGS), or mesangial proliferation (MP) on light microscopy and effacement of foot processes on electron microscopy. Actually the podocyte has become the favourite candidate for constituting the main part of the glomerular filtration barrier. Most cases are steroid sensitive (SSINS). Fifty percents of the latter recur frequently and necessitate a prevention of relapses by nonsteroid drugs. On the contrary to SSINS, steroid resistant nephrotic syndrome (SRINS) leads often to end-stage renal failure. Thirty to forty percents of the latter are associated with mutations of genes coding for podocyte proteins. The rest is due to one or several different circulating factors. New strategies are in development to antagonize the effect of the latter

Biomass heat storage dampens diurnal temperature variations in forests

Observational evidence suggests that compared to non-forested areas, forests have a cooling effect on daytime land surface temperature (LST) and a warming effect on nighttime LST in many regions of the world, thus implying that forests dampen the diurnal temperature range. This feature is not captured by current climate models. Using the Community Land Model 5.0 (CLM5.0), we show that this diurnal behavior can be captured when accounting for biomass heat storage (BHS). The nighttime release of energy absorbed by the vegetation biomass during the day increases both nighttime LST and ambient air temperature in forested regions by more than 1 K. The daytime cooling is weaker than the nighttime warming effect, because the energy uptake by the biomass is compensated by a reduction in the turbulent heat fluxes during day. This diurnal asymmetry of the temperature response to BHS leads to a warming of daily mean temperatures, which is amplified during boreal summer warm extremes. Compared to MODIS, CLM5.0 overestimates the diurnal LST range over forested areas. The inclusion of BHS reduces this bias due to its dampening effect on diurnal LST variations. Further, BHS attenuates the negative bias in the nighttime LST difference of forest minus grassland and cropland, when compared to MODIS observations. These results indicate that it is essential to consider BHS when examining the influence of forests on diurnal temperature variations. BHS should thus be included in land surface models used to assess the climatic consequences of land use changes such as deforestation or afforestation

Delimiting Cryptic Morphological Variation among Human Malaria Vector Species using Convolutional Neural Networks

Deep learning is a powerful approach for distinguishing classes of images, and there is a growing interest in applying these methods to delimit species, particularly in the identification of mosquito vectors. Visual identification of mosquito species is the foundation of mosquito-borne disease surveillance and management, but can be hindered by cryptic morphological variation in mosquito vector species complexes such as the malaria-transmitting Anopheles gambiaecomplex. We sought to apply Convolutional Neural Networks (CNNs) to images of mosquitoes as a proof-of-concept to determine the feasibility of automatic classification of mosquito sex, genus, species, and strains using whole-body, 2D images of mosquitoes. We introduce a library of 1, 709 images of adult mosquitoes collected from 16 colonies of mosquito vector species and strains originating from five geographic regions, with 4 cryptic species not readily distinguishable morphologically even by trained medical entomologists. We present a methodology for image processing, data augmentation, and training and validation of a CNN. Our best CNN configuration achieved high prediction accuracies of 96.96% for species identification and 98.48% for sex. Our results demonstrate that CNNs can delimit species with cryptic morphological variation, 2 strains of a single species, and specimens from a single colony stored using two different methods. We present visualizations of the CNN feature space and predictions for interpretation of our results, and we further discuss applications of our findings for future applications in malaria mosquito surveillance

Neutron to proton ratios of quasiprojectile and midrapidity emission in the 64^{64}Zn + 64^{64}Zn reaction at 45 MeV/nucleon

Simultaneous measurement of both neutrons and charged particles emitted in the reaction $^{64}$Zn + $^{64}$Zn at 45 MeV/nucleon allows comparison of the neutron to proton ratio at midrapidity with that at projectile rapidity. The evolution of N/Z in both rapidity regimes with increasing centrality is examined. For the completely re-constructed midrapidity material one finds that the neutron-to-proton ratio is above that of the overall $^{64}$Zn + $^{64}$Zn system. In contrast, the re-constructed ratio for the quasiprojectile is below that of the overall system. This difference provides the most complete evidence to date of neutron enrichment of midrapidity nuclear matter at the expense of the quasiprojectile