Individual Differences in Performance Speed Are Associated With a Positivity/Negativity Bias. An ERP and Behavioral Study

There is a current dispute over the origins, incidence, and development of Positivity Bias, i.e., preferential processing of positive relative to negative information. We addressed this question using a multi-method technique of behavioral, psychometric and event-related potential (ERP) measures in a lexical decision task (LDT). Twenty-four university students (11 female) participated (age range 18–26), but four were omitted owing to data issues. Participants were classified as Positivity Biased (PB) if their LDT responses to positive words were faster than negative words, and vice versa for those classified as Negativity Biased (NB), leading to a group of 11 PB participants and a group of 9 NB participants. Interestingly, the PB group was significantly faster overall than the NB group and had significantly shorter P2 component ERP latencies in the left occipital region. Furthermore, the PB group had significantly higher scores for expressive suppression (ES), together with higher scores for Crystallized Knowledge and for cognitive reappraisal (CR). These results suggest that around 55% of the students had Positivity Bias, and these were more efficient in processing information and had better emotion regulation abilities than those with a Negativity Bias

Effect of pH on superoxide/ hydroperoxyl radical trapping by nitrones: an EPR/kinetic study

International audienceThe pH dependence of the apparent rate constant kTap for O2-./HO2. trapping by four nitrones was examined. In each case, kinetic curves were obtained after treatment of EPR spectra of the spin adduct formed using both singular value decomposition and pseudo-inverse deconvolution methods. Modelling these curves led to evaluate kTap at various pH values. Analysis of the pH dependence of kTap permitted the determination of the rate constants for the spin trapping of O2-. and of HO2. separately. Whatever the nitrone, our results clearly show that the EPR signals of the nitrone/superoxide spin adducts observed in aqueous media were essentially due to the trapping of the protonated species HO2

Agreeing on efficient emissions reduction

We propose a simple mechanism providing incentives to reduce harmful emissions to their efficient level without infracting upon productive efficiency. The mechanism employs a contest creating incentives among participating nations to simultaneously exert efficient productive and efficient abatement efforts. Participation in the most stylised form of the scheme is voluntary and individually rational; all rules are mutually agreeable and are unanimously adopted if proposed. The scheme balances its budget and requires no principal. In a perhaps more realistic stochastic output version which could potentially inform policy decisions, we show that the transfers required by the efficient mechanism create a mutual insurance motive which may serve as effective rationale for the (gradual) formation of International Environmental Agreements

Spin-dependent lifetime and exchange splitting of surface states on Ni(1 1 1)

We report on a spin-resolved two-photon photoemission study of the Ni(1 1 1) surface states. Nickel thin films were grown by molecular beam epitaxy on a W(1 1 0) substrate. The first image-potential state is used as a sensor to map the spin polarization of the occupied surface states. This allows us to identify the majority spin component of the Shockley surface state as well as a majority and minority d-derived surface resonance. The n = 1 image-potential state is found to be exchange split by 14 ± 3 meV. In spite of the fact that the band structure at the Fermi level exhibits a strongly discerned density of states in both spin channels, we observe low spin asymmetries in the decay and dephasing rates of the photoexcited electrons. Varying the sample preparation reveals that the Shockley surface state contributes about 40% to the spin- dependent decay rate

Antimicrobial Sensitivity in Enterobacteria from AIDS Patients, Zambia

Enterobacteria contribute to two serious clinical syndromes seen in African AIDS patients: diarrhea and septicemia. In West Africa, prophylaxis with sulfamethoxazole-trimethoprim (SXT) reduced illnesses. We report reduced sensitivity of enterobacteria to available antimicrobial agents in Zambia, with only 22% of nontyphoidal salmonellae and 6% of shigellae sensitive to SXT

Efficient emissions reduction

We propose a simple mechanism capable of achieving international agreement on the reduction of harmful emissions to their efficient level. It employs a contest creating incentives among participating nations to simultaneously exert efficient productive and efficient abatement efforts. Participation in the most stylised formulation of the scheme is voluntary and individually rational. All rules are mutually agreeable and are unanimously adopted if proposed. The scheme balances its budget and requires no principal. The mechanism provides a benchmark result for the cost of the implementation of these desirable properties. In a more realistic setup which could potentially inform policy decisions, we discuss participation enforcement through punishment clauses, exclusive trade agreements and environmental standards and show that they are effectively discouraging free-riding

Single cell phosphoproteomics identifies adaptive network dynamics of mTOR inhibitor resistance and defines effective combination therapy in glioblastoma

Resistance to single-agent targeted cancer therapy is almost universal. Resistance can occur when drug-resistant tumor cell subpopulations expand to drive recurrence in a process akin to Darwinian-type evolution under the selection pressure of the drug. An alternative resistance mechanism is the one in which cancer cells targeted by the inhibitor adapt to that drug, so as to maintain the signal flux through those networks that are required for tumor maintenance and growth. The main goal of this study is to identify the mechanisms of resistance in a targeted therapy by analyzing single cells and to provide a strategy to design a more effective therapy that suppresses resistance