Winter Anomaly of the Lower Ionosphere and Its Possible Causes

It is a well-known fact that in winter the midlatitude lower ionosphere differs considerably from that in summer. Attempts to explain the possible causes of the winter anomaly in the lower ionosphere were made. Integrated ground-based and rocket experiments were performed in the USSR. The rockets M-100B launched in Volgograd (psi = 48.7 deg N; lambda = 44.3 deg E; psi = 43.1 deg) provided weight profiles of electron density, wind and temperature. Radio wave absorption data obtained by a I method in Volgograd and F sub min parameters values obtained at a number of Soviet ionosone stations were used to determine the situation in the lower ionosphere. It was found that a correct interpretation of the midlatitude winter radio wave absorption changes is possible only if the whole spatial-time pattern of the event is taken into account

Interlayer Registry Determines the Sliding Potential of Layered Metal Dichalcogenides: The case of 2H-MoS2

We provide a simple and intuitive explanation for the interlayer sliding energy landscape of metal dichalcogenides. Based on the recently introduced registry index (RI) concept, we define a purely geometrical parameter which quantifies the degree of interlayer commensurability in the layered phase of molybdenum disulphide (2HMoS2). A direct relation between the sliding energy landscape and the corresponding interlayer registry surface of 2H-MoS2 is discovered thus marking the registry index as a computationally efficient means for studying the tribology of complex nanoscale material interfaces in the wearless friction regime.Comment: 13 pages, 7 figure

Hydrophobically stabilized open state for the lateral gate of the Sec translocon

The Sec translocon is a central component of cellular pathways for protein translocation and membrane integration. Using both atomistic and coarse-grained molecular simulations, we investigate the conformational landscape of the translocon and explore the role of peptide substrates in the regulation of the translocation and integration pathways. Inclusion of a hydrophobic peptide substrate in the translocon stabilizes the opening of the lateral gate for membrane integration, whereas a hydrophilic peptide substrate favors the closed lateral gate conformation. The relative orientation of the plug moiety and a peptide substrate within the translocon channel is similarly dependent on whether the substrate is hydrophobic or hydrophilic in character, and the energetics of the translocon lateral gate opening in the presence of a peptide substrate is governed by the energetics of the peptide interface with the membrane. Implications of these results for the regulation of Sec-mediated pathways for protein translocation vs. membrane integration are discussed

The UN in the lab

We consider two alternatives to inaction for governments combating terrorism, which we term Defense and Prevention. Defense consists of investing in resources that reduce the impact of an attack, and generates a negative externality to other governments, making their countries a more attractive objective for terrorists. In contrast, Prevention, which consists of investing in resources that reduce the ability of the terrorist organization to mount an attack, creates a positive externality by reducing the overall threat of terrorism for all. This interaction is captured using a simple 3×3 “Nested Prisoner’s Dilemma” game, with a single Nash equilibrium where both countries choose Defense. Due to the structure of this interaction, countries can benefit from coordination of policy choices, and international institutions (such as the UN) can be utilized to facilitate coordination by implementing agreements to share the burden of Prevention. We introduce an institution that implements a burden-sharing policy for Prevention, and investigate experimentally whether subjects coordinate on a cooperative strategy more frequently under different levels of cost sharing. In all treatments, burden sharing leaves the Prisoner’s Dilemma structure and Nash equilibrium of the game unchanged. We compare three levels of burden sharing to a baseline in a between-subjects design, and find that burden sharing generates a non-linear effect on the choice of the efficient Prevention strategy and overall performance. Only an institution supporting a high level of mandatory burden sharing generates a significant improvement in the use of the Prevention strategy

Isolation of streptomycetes causing common scab from 3-years old potato samples from South America

In this paper, we aimed at assessing the best conditions for the isolation of actinobacteria from old potato samples. A set of media and pretreatments were tested. The optimal were chosen for the isolation of actinobacteria from potatoes from Peru, Chile and Argentina. Isolates were tested on the presence of thaxtomin phytotoxin by amplification of the respective gene. Phylogenetic position of strains was compared with their geographical origin, pathogenic potential and existence of common scab (CS) symptoms on potato sample. We demonstrated that RNAlater can be successfully used for the long-term preservation of potato peel for subsequent isolation of actinobacteria on R2A medium. Many streptomycetes were thaxtomin-positive, though they are distantly-related to described pathogens causing CS. Genus Nocardia was first reported to be thaxtomin-positive. Potentially pathogenic strains were isolated not only from infected potato but also from those lacking CS symptoms. Some strains from scabby potatoes were thaxtomin-negative.EEA BalcarceFil: Rapoport, Daria. Charles University in Prague. Faculty opf Science, República Checa. Crop Research Institute, Laboratory of Epidemiology and Ecology of Microorganisms, República Checa.Fil: Patrmanova, T. Crop Research Institute, Laboratory of Epidemiology and Ecology of Microorganisms, República Checa.Fil: Kopecky, J. Crop Research Institute, Laboratory of Epidemiology and Ecology of Microorganisms, República Checa.Fil: Mareckova, M. Crop Research Institute, Laboratory of Epidemiology and Ecology of Microorganisms, República Checa. Czech University of Life Sciences, Faculty of Agrobiology, Food, and Natural Resources, Department of Microbiology, República Checa.Fil: Clemente, Gladys. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Salvalaggio, Andrea Eugenia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

Networks of Mobilization: Student Involvement in a Municipal Election

An enduring issue in the study of political participation is the extent to which political awareness and engagement are socially or individually motivated. We address these issues in the context of a municipal election which generated a high level of political engagement on the part of college students for whom the election was relevant. An effort was made to interview all these students using an on-line survey, and the students were asked to provide information on their friendship networks. The paper demonstrates that awareness and engagement are not simply a consequence of individually defined interests and awareness, but rather that individuals are informed and engaged based on their locations within structured networks of social interaction