The nucleolus and kernel of veto-rich transferable utility games

Game Theory

Gender differences in response to contingent rewards: Evidence from a natural experiment of junior tennis

We investigate gender differences in responding to contingent rewards by exploiting a natural experiment in junior tennis tournaments in Florida where the ranking point system was revised to induce more players to play doubles. The new point system increased the points earned from wins in singles matches significantly if the two thirds or more of players in their sex/age group chose to play doubles. We examine three types of potential responses to the new system: (1) a ‘positive’ response of playing doubles more by singles winners, (2) a ‘subversive’ response of playing doubles less by singles losers, and (3) a ‘slack’ response of playing loosely in their doubles matches by singles winners. We find strong evidence on the positive response among boys and top-ranked girls but no evidence for subversive and slack responses

A bargaining procedure leading to the serial rule in games with veto players

This paper studies an allocation procedure for coalitional games with veto players. The procedure is similar to the one presented by Arin and Feltkamp (J Math Econ 43:855-870, 2007), which is based on Dagan et al. (Games Econ Behav 18:55-72, 1997). A distinguished player makes a proposal that the remaining players must accept or reject, and conflict is solved bilaterally between the rejector and the proposer. We allow the proposer to make sequential proposals over several periods. If responders are myopic maximizers (i.e. consider each period in isolation), the only equilibrium outcome is the serial rule of Arin and Feltkamp (Eur J Oper Res 216:208-213, 2012) regardless of the order of moves. If all players are fully rational, the serial rule still arises as the unique subgame perfect equilibrium outcome if the order of moves is such that stronger players respond to the proposal after weaker ones

Introduction to The Special Issue: Advances in Methods and Measurement in Family Psychology

This special issue presents a collection of reports that highlight recent advances in methods and measurement and also shed light on the complexity of family psychology. The importance of theory in guiding solid family science is evident throughout these reports. The reports include guides for researchers who incorporate direct observation into their research protocols and the ever-expanding field of tele-health interventions. Advanced analytic approaches are offered in the areas of grid sequence analysis, latent fixed-effects models, and the Factors of Curves Model (FOCUS). These sophisticated analytic approaches may be applied to advance systemic thinking in family psychology. The last set of articles illustrate how complex and innovative methodologies are applied to address important societal issues. Work experiences and marital relationships in African American couples address the importance of spillover effects in contemporary families. The creation of biobehavioral plasticity index has the potential to inform gene x environment contributions to family functioning. Finally, the unique methodological issues that are particularly germane to the diverse nature of stepfamilies and nonresident fathers are addressed. We hope that readers of this special issue will return to these reports as resources and examples of theory-driven methods and measurements

Evaluation of the control of onchocerciasis through community-directed treatment with ivermectin (cdti) in selected villages of Jos east local government area, Plateau State

Community Directed mass ivermectin® treatment (CDTI) programme of the National Onchocerciasis control was evaluated in five randomly selected villages in Jos East Local Government Area by clinical and parasitologicalmethods. Oral interview using structured questionnaire was used to asses awareness and level of drug compliance. A total of 452 persons from the study area were selected by stratified random sampling for clinical and parasitological evaluation. An overall prevalence of 15.7% was observed using both clinical and parasitological assessment. Clinically, 30 (5.5%); 32 (5.9%); 4 (0.7%) and 3 (0.6%) persons were manifesting leopard skin, nodules, hanging groin and elephantiasis lesions respectively. Parasitological examination by skin biopsy revealed that only 2 (0.4%) persons were positive for microfilaria of Onchocerca volvolus, which is an indication of a decrease in active cases among the population. All the positive cases confessed non compliance with drug use. Generally there appears to be a remarkable decrease in the prevalence of Onchocerciasis in the study area compared to earlier report of 27.9% in the 1980’s. This could be attributed to efficacy of ivermectin and increased awareness among the general public of the need on compliance with the drug. Concerted and coordinated mass enlightenment should be sustained to eradicate the pockets of active cases to eliminate all possible sources of infection

Ugnu pilot area - simulation model and sensitivity analysis

Master's Project (M.S.) University of Alaska Fairbanks, 2020Collaborating with Hilcorp Alaska, LLC, the Ugnu pilot area is the subject of this project. Hilcorp Alaska is conducting field pilot test at Milne Point Field to prove commerciality with Ugnu heavy oil as well as an on-going Milne viscous oil polymer flood field pilot test in the Schrader Bluff sands. The Ugnu sand heavy oil represents much of the heavy oil on Alaska’s North Slope and has potential for future development. Typical heavy oil has a viscosity of 1,000 - 10,000 centipoise, approximately akin to viscosities of honey and molasses, respectively. North Slope heavy oil is located around 3,000-foot depths and typically overlays existing fields. The project involves a reservoir simulation model and sensitivity analysis to support developmental drilling plans from a Milne Point Unit pad. Necessary geologic and reservoir properties were provided for usage in this project by Hilcorp. Production data was provided for history matching. Field geologic background was also supplied to aid in the understanding of the reservoir. The reservoir simulation model was built using Computer Modelling Group software, namely Builder and IMEX. The first model iteration contained one producer in an 8,500-foot lateral pattern. Further iterations included additional producers and injectors for waterflood and polymer flood studies. Conclusions and recommendations were drawn upon analyzing the reservoir simulation results centering around favorable production strategies, polymer flood performance, comparison to the on-going Milne viscous oil polymer flood pilot, and future polymer flood studies. Completed objectives of this project included: 1. Developing a numerical reservoir simulation model for the Ugnu MB sand in the pilot area; 2. Evaluating the productivity of horizontal wells in the Ugnu MB sand; 3. Predicting ultimate oil recovery with waterflood and polymer flood; 4. Predicting polymer utilization, polymer injected per incremental oil barrels over waterflood

Proton transfer unlocks inactivation in cyclic nucleotide-gated A1 channels

Key points: Desensitization and inactivation provide a form of short-term memory controlling the firing patterns of excitable cells and adaptation in sensory systems. Unlike many of their cousin K+ channels, cyclic nucleotide-gated (CNG) channels are thought not to desensitize or inactivate. Here we report that CNG channels do inactivate and that inactivation is controlled by extracellular protons. Titration of a glutamate residue within the selectivity filter destabilizes the pore architecture, which collapses towards a non-conductive, inactivated state in a process reminiscent of the usual C-type inactivation observed in many K+ channels. These results indicate that inactivation in CNG channels represents a regulatory mechanism that has been neglected thus far, with possible implications in several physiological processes ranging from signal transduction to growth cone navigation. Ion channels control ionic fluxes across biological membranes by residing in any of three functionally distinct states: deactivated (closed), activated (open) or inactivated (closed). Unlike many of their cousin K+ channels, cyclic nucleotide-gated (CNG) channels do not desensitize or inactivate. Using patch recording techniques, we show that when extracellular pH (pHo) is decreased from 7.4 to 6 or lower, wild-type CNGA1 channels inactivate in a voltage-dependent manner. pHo titration experiments show that at pHo < 7 the I-V relationships are outwardly rectifying and that inactivation is coupled to current rectification. Single-channel recordings indicate that a fast mechanism of proton blockage underlines current rectification while inactivation arises from conformational changes downstream from protonation. Furthermore, mutagenesis and ionic substitution experiments highlight the role of the selectivity filter in current decline, suggesting analogies with the C-type inactivation observed in K+ channels. Analysis with Markovian models indicates that the non-independent binding of two protons within the transmembrane electrical field explains both the voltage-dependent blockage and the inactivation. Low pH, by inhibiting the CNGA1 channels in a state-dependent manner, may represent an unrecognized endogenous signal regulating CNG physiological functions in diverse tissues