Quasi-Perfect Stackelberg Equilibrium

Equilibrium refinements are important in extensive-form (i.e., tree-form) games, where they amend weaknesses of the Nash equilibrium concept by requiring sequential rationality and other beneficial properties. One of the most attractive refinement concepts is quasi-perfect equilibrium. While quasi-perfection has been studied in extensive-form games, it is poorly understood in Stackelberg settings---that is, settings where a leader can commit to a strategy---which are important for modeling, for example, security games. In this paper, we introduce the axiomatic definition of quasi-perfect Stackelberg equilibrium. We develop a broad class of game perturbation schemes that lead to them in the limit. Our class of perturbation schemes strictly generalizes prior perturbation schemes introduced for the computation of (non-Stackelberg) quasi-perfect equilibria. Based on our perturbation schemes, we develop a branch-and-bound algorithm for computing a quasi-perfect Stackelberg equilibrium. It leverages a perturbed variant of the linear program for computing a Stackelberg extensive-form correlated equilibrium. Experiments show that our algorithm can be used to find an approximate quasi-perfect Stackelberg equilibrium in games with thousands of nodes

Hematological and Morphological Analysis of the Erythropoietic Regenerative Response in Phenylhydrazine-induced Hemolytic Anemia in Mice

In this study we developed a mouse model of Phenylhydrazine (PHZ) -induced hemolytic anemia to study  erythropoietic regenerative response through clinical, pathological, and morphological studies. Hemolytic  anemia was induced in female mice (CF1) using PHZ at a wide range of doses (up to 100 mg/Kg) on days  0 and 2. Hemolytic anemia was observed at 60 mg/kg PHZ on day 4 and was evidenced by decreased HCT  (34.3±0.28%), reticulocytosis (51.6±2.10%), anisocytosis, poikilocytosis, leukocytosis, and increased  Heinz body count. A time-course and dose-dependence analysis of the regenerative response was performed.  HCT decreased on days 2 and 4 in a dose-dependent manner, returning to basal levels on day 8.  PHZ only induced reticulocytosis (day 4) at the highest doses tested (60-100 mg/kg). Heinz body formation  was dose-dependent. These changes were accompanied by splenomegaly and splenic erythroid hyperplasia.  Results revealed that the presence of erythroblastic islands was most clear in the spleen, followed by the  liver and kidney. SEM showed Heinz body-containing erythrocytes and spherocyte-like erythrocytes.  Anemia recovery results from coordinated action of extramedullary tissues depending on the time post  injection and the dose applied. In conclusion, this mouse model allowed us a better understanding of  murine erythropoietic regenerative response.

Electronic Properties of Functionalized Diamanes for Field-Emission Displays

Ultrathin diamond films, or diamanes, are promising quasi-2D materials that are characterized by high stiffness, extreme wear resistance, high thermal conductivity, and chemical stability. Surface functionalization of multilayer graphene with different stackings of layers could be an interesting opportunity to induce proper electronic properties into diamanes. Combination of these electronic properties together with extraordinary mechanical ones will lead to their applications as field-emission displays substituting original devices with light-emitting diodes or organic light-emitting diodes. In the present study, we focus on the electronic properties of fluorinated and hydrogenated diamanes with (111), (110), (0001), (101̅0), and (2̅110) crystallographic orientations of surfaces of various thicknesses by using first-principles calculations and Bader analysis of electron density. We see that fluorine induces an occupied surface electronic state, while hydrogen modifies the occupied bulk state and also induces unoccupied surface states. Furthermore, a lower number of layers is necessary for hydrogenated diamanes to achieve the convergence of the work function in comparison with fluorinated diamanes, with the exception of fluorinated (110) and (2̅110) films that achieve rapid convergence and have the same behavior as other hydrogenated surfaces. This induces a modification of the work function with an increase of the number of layers that makes hydrogenated (2̅110) diamanes the most suitable surface for field-emission displays, better than the fluorinated counterparts. In addition, a quasi-quantitative descriptor of surface dipole moment based on the Tantardini−Oganov electronegativity scale is introduced as the average of bond dipole moments between the surface atoms. This new fundamental descriptor is capable of predicting a priori the bond dipole moment and may be considered as a new useful feature for crystal structure prediction based on artificial intelligence

Rapid and dfferential evolution of the venom composition of a parasitoid wasp depending on the host strain

Abstract: Parasitoid wasps rely primarily on venom to suppress the immune response and regulatethe physiology of their host. Intraspecific variability of venom protein composition has beendocumented in some species, but its evolutionary potential is poorly understood. We performed anexperimental evolution initiated with the crosses of two lines of Leptopilina boulardi of differentvenom composition to generate variability and create new combinations of venom factors. Theoffspring were maintained for 10 generations on two strains of Drosophila melanogaster differing inresistance/susceptibility to the parental parasitoid lines. The venom composition of individuals wascharacterized by a semi-automatic analysis of 1D SDS-PAGE electrophoresis protein profiles whoseaccuracy was checked by Western blot analysis of well-characterized venom proteins. Results madeevident a rapid and differential evolution of the venom composition on both hosts and showed thatthe proteins beneficial on one host can be costly on the other. Overall, we demonstrated the capacityof rapid evolution of the venom composition in parasitoid wasps, important regulators of arthropodpopulations, suggesting a potential for adaptation to new hosts. Our approach also proved relevantin identifying, among the diversity of venom proteins, those possibly involved in parasitism successand whose role deserves to be deepened

Predictors of prosocial behavior during the COVID-19 national lockdown in Italy: Testing the role of psychological sense of community and other community assets

There is growing support for viewing communities as a multilevel construct in which the interdependence between individuals and community systems contributes to the promotion of individual responsibilities in thinking and enacting changes to respond to people’s and community’s needs. However, there is currently scant evidence regarding the influence of psychological sense of community and the role of community assets on prosocial behavior during the COVID-19 national lockdown. The main aim of the current study was to test a conceptual model of community assets as predictors of prosocial behavior during Italy’s COVID-19 national lockdown. A sample of 3,964 Italian adults was involved in the current study. We collected data using an online questionnaire, between April 12 and May 21, 2020, during the nationwide lockdown restrictions. To collect data, we employed convenience and virtual snowball sampling strategies (i.e., email, social networks, and online channels). Using structural equation modeling, we found that prosocial behavior was predicted by sense of community responsibility but not by sense of community. Moreover, sense of community and sense of community responsibility were predicted by community members’ perception of its assets, in particular collective resilience and adequate information. Finally, trust in the institutional response to the pandemic predicted community members’ perception of collective resilience and receiving adequate information through the community. The present study suggests that community qualities, positively perceived by community members, are crucial in promoting prosocial behaviors and producing collective goods during a pandemic

The selective effect of lockdown experience on citizens' perspectives: A multilevel, multiple informant approach to personal and community resilience during COVID-19 pandemic

In the face of the first wave of COVID-19 contagion, citizens all over the world experienced concerns for their safety and health, as well as prolonged lockdowns – which brought about limitations but also unforeseen opportunities for personal growth. Broad variability in these psychological responses to such unprecedented experiences emerged. This study addresses this variability by investigating the role of personal and community resilience. Personal resilience, collective resilience, community disaster management ability, provided information by local authorities, and citizens' focus on COVID-19-related personal concerns and lockdown-related opportunities for personal growth were detected through an online questionnaire. Multilevel modelling was run with data from 3,745 Italian citizens. The potential of personal resilience as a driver for individuals to overcome adverse situations with positive outcomes was confirmed. Differently, the components of community resilience showed more complex paths, highlighting the need to pay more attention to its role in the face of far-reaching adverse events which hardly test individuals' as well as communities' adaptability and agency skills. The complexities linked to the multi-component and system-specific nature of resilience, as well as potential paths towards making the most out of citizens' and communities' ones, emerge. The theoretical and practical implications are discussed

Emergency online school learning during COVID-19 lockdown: A qualitative study of adolescents' experiences in Italy

The COVID-19 pandemic caused abrupt and profound changes to teaching and learning. The present study seeks to understand adolescents' experiences of the emergency adoption of online school learning (OSL) during the first national lockdown in Italy. Sixty-four students in their final two years of high school were interviewed and content analysis was performed. The findings describe students' views of the changes related to OSL according to structural, individual and relational dimensions. Schools' lack of organization, overwhelming demands, as well as experience of difficulties in concentration, stress and inhibited relationships with teachers and classmates were among the challenges evidenced in the transition. OSL, however, has also made it possible to experience a new flexibility and autonomy in the organization of learning. The study stresses the importance of fostering adaptation of teacher-student relationships and collaborative learning in order to improve schools' preparedness for digital transitions in and out of emergencies

The number of tree species on Earth

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global groundsourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.EEA Santa CruzFil: Cazzolla Gatti, Roberto. Purdue University. Department of Forestry and Natural Resources; Estados UnidosFil: Cazzolla Gatti, Roberto. University of Bologna. Department of Biological, Geological, and Environmental Sciences.Alma Mater Studiorum; ItaliaFil: Cazzolla Gatti, Roberto. Tomsk State University. Biological Institute; Rusia.Fil: Reichd, Peter B. University of Minnesota. Department of Forest Resources; Estados UnidosFil: Reichd, Peter B. University of Michigan. Institute for Global Change Biology and School for Environment and Sustainability; Estados UnidosFil: Reichd, Peter B. Western Sydney University. Hawkesbury Institute for the Environment; Australia.Fil: Gamarra, Javier G. P. FAO. Forestry Department; ItaliaFil: Crowtherh, Tom. Institute of Integrative Biology; SuizaFil: Hui, Cang. Stellenbosch University. iCentre for Invasion Biology. Department of Mathematical Sciences; SudáfricaFil: Hui, Cang. African Institute for Mathematical Sciences. Mathematical Biology Unit; SudáfricaFil: Morera, Albert. University of Lleida. Department of Crop and Forest Sciences; EspañaFil: Morera, Albert. Joint Research Unit CTFC–AGROTECNIO–CERCA; EspañaFil: Bastin, Jean-Francois. University of Liege. TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech; BélgicaFil: de-Miguel, Sergio. University of Lleida. Department of Crop and Forest Sciences; EspañaFil: de-Miguel, Sergio. Joint Research Unit CTFC–AGROTECNIO–CERCA; EspañaFil: Jan Nabuurs, Gert. Wageningen University. Research Forest Ecology and Forest Management Group; Países BajosFil: Svenning, Jens -Christian. Aarhus University. Center for Biodiversity Dynamics in a Changing World (BIOCHANGE). Department of Biology; DinamarcaFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Liang, Jingjing. Purdue University. Department of Forestry and Natural Resources; Estados Unido

A film-forming graphene/diketopyrrolopyrrole covalent hybrid with far-red optical features: Evidence of photo-stability

A dianiline derivative of a symmetric donor-acceptor-donor diketopyrrolopyrrole-based dye is employed for the two-sided covalent functionalization of liquid exfoliated few layers graphene flakes, through a direct arylation reaction. The resulting nanohybrid features the properties of a polymeric species, being solution-processed into homogeneous thin films, featuring a pronounced red-shift of the main absorption band with respect to the model dye unit and energy levels comparable to those of common diketopyrrolopyrrole-based polymers. A good electrical conductivity and the absence of radical signals generated after intense white light illumination, as probed through electron paramagnetic resonance, suggest a possible future application of this composite material in the field of photoprotective, antistatic layers with tunable colors