Games with Delays. A Frankenstein Approach

We investigate infinite games on finite graphs where the information flow is perturbed by nondeterministic signalling delays. It is known that such perturbations make synthesis problems virtually unsolvable, in the general case. On the classical model where signals are attached to states, tractable cases are rare and difficult to identify. Here, we propose a model where signals are detached from control states, and we identify a subclass on which equilibrium outcomes can be preserved, even if signals are delivered with a delay that is finitely bounded. To offset the perturbation, our solution procedure combines responses from a collection of virtual plays following an equilibrium strategy in the instant- signalling game to synthesise, in a Frankenstein manner, an equivalent equilibrium strategy for the delayed-signalling game

The origin of the Canary Island Seamount Province - New ages of old seamounts

The Canary Island Seamount Province forms a scattered hotspot track on the Atlantic ocean floor ,1300 km long and,350 km wide, perpendicular to lithospheric fractures, and parallel to theNWAfrican continental margin. New 40Ar/39Ar datings show that seamount ages vary from 133 Ma to 0.2 Ma in the central archipelago, and from 142 Ma to 91 Ma in the southwest. Combining 40Ar/39Ar ages with plate tectonic reconstructions, I find that the temporal and spatial distribution of seamounts is irreconcilable with a deep fixed mantle plume origin, or derivation from passive mantle upwelling beneath a mid-ocean ridge. I conclude that shallow mantle upwelling beneath the Atlantic Ocean basin off the NW African continental lithosphere flanks produced recurrent melting anomalies and seamounts from the Late Jurassic to Recent, nominating the Canary Island Seamount Province as oldest hotspot track in the Atlantic Ocean, and most long-lived preserved on earth

40Ar/39Ar ages of Pliocene-Pleistocene fallout tephra layers and volcaniclastic deposits in the sedimentary aprons of Gran Canaria and Tenerife (Sites 953, 954, and 956)

Six fallout tephra layers and 16 heterolithologic volcaniclastic deposits drilled at Holes 953A, 954A, 954B, and 956A, during Leg 157 in the sedimentary aprons of Gran Canaria and Tenerife, have been dated by single crystal laser 40Ar/39Ar analysis. The fallout tephra markers range in age from 0.273 ± 0.006 Ma to 2.74 ± 0.01 Ma. Maximum sedimentation ages determined for the volcaniclastic deposits range from 0.24 ± 0.01 Ma to 2.24 ± 0.02 Ma, closely matching the nannofossil and paleomagnetic chronostratigraphies of the cores. Both tephra and volcaniclastic layers represent material from Pliocene–Pleistocene explosive eruptions of the Cañadas Caldera (Tenerife), mixed with Miocene volcanic debris only in the holes drilled north of Gran Canaria (954A and 954B). Two fallout layers (0.61 ± 0.02 Ma and 1.83 ± 0.02 Ma) and five volcaniclastic deposits reflect explosive eruptions, which took place during postulated dormant stages of the Cañadas edifice

On the Complexity of SPEs in Parity Games

We study the complexity of problems related to subgame-perfect equilibria (SPEs) in infinite duration non zero-sum multiplayer games played on finite graphs with parity objectives. We present new complexity results that close gaps in the literature. Our techniques are based on a recent characterization of SPEs in prefix-independent games that is grounded on the notions of requirements and negotiation, and according to which the plays supported by SPEs are exactly the plays consistent with the requirement that is the least fixed point of the negotiation function. The new results are as follows. First, checking that a given requirement is a fixed point of the negotiation function is an NP-complete problem. Second, we show that the SPE constrained existence problem is NP-complete, this problem was previously known to be ExpTime-easy and NP-hard. Third, the SPE constrained existence problem is fixed-parameter tractable when the number of players and of colors are parameters. Fourth, deciding whether some requirement is the least fixed point of the negotiation function is complete for the second level of the Boolean hierarchy. Finally, the SPE-verification problem - that is, the problem of deciding whether there exists a play supported by a SPE that satisfies some LTL formula - is PSpace-complete, this problem was known to be ExpTime-easy and PSpace-hard

Radiation-induced cardiac toxicity in breast cancer patients

Breast cancer is the most common type of cancer in women in the Netherlands. Of all women diagnosed with cancer, 28% have breast cancer. Most women diagnosed with breast cancer are treated with surgery, followed by additional radiotherapy. When the breast is irradiated, it is unavoidable that a certain amount of radiation also penetrates into the heart. This is especially the case when the left breast is irradiated.Consequently, breast cancer radiotherapy may damage the heart, which increases the risk of cardiac complications, such as the risk of a heart attack. The research presented in this thesis show that women treated for breast cancer with surgery and radiotherapy have an increased risk of developing cardiac complications. The risk on cardiac complications increases with an increasing dose to the heart. We also identified specific regions of the heart in which the dose has more effect on the development of cardiac complications, such as the left ventricle.With the information derived from this research project, we will be able to identify breast cancer patients who are at high risk for heart damage after breast cancer treatment. By identifying these future high risk patients, it is possible to take preventive measures to minimize the risk of cardiac complications, such as development of radiation techniques that can minimize the radiation dose to the most vulnerable parts of the heart

Rational Verification for Nash and Subgame-Perfect Equilibria in Graph Games

We study a natural problem about rational behaviors in multiplayer non-zero-sum sequential infinite duration games played on graphs: rational verification, that consists in deciding whether all the rational answers to a given strategy satisfy some specification. We give the complexities of that problem for two major concepts of rationality: Nash equilibria and subgame-perfect equilibria, and for three major classes of payoff functions: energy, discounted-sum, and mean-payoff