Dynamical damping terms for symmetry-seeking shift conditions

Suitable gauge conditions are fundamental for stable and accurate numerical-relativity simulations of inspiralling compact binaries. A number of well-studied conditions have been developed over the last decade for both the lapse and the shift and these have been successfully used both in vacuum and non-vacuum spacetimes when simulating binaries with comparable masses. At the same time, recent evidence has emerged that the standard "Gamma-driver" shift condition requires a careful and non-trivial tuning of its parameters to ensure long-term stable evolutions of unequal-mass binaries. We present a novel gauge condition in which the damping constant is promoted to be a dynamical variable and the solution of an evolution equation. We show that this choice removes the need for special tuning and provides a shift damping term which is free of instabilities in our simulations and dynamically adapts to the individual positions and masses of the binary black-hole system. Our gauge condition also reduces the variations in the coordinate size of the apparent horizon of the larger black hole and could therefore be useful when simulating binaries with very small mass ratios.Comment: 11 pages, 8 figure

Accurate Simulations of Binary Black Hole Mergers in Force-free Electrodynamics

We provide additional information on our recent study of the electromagnetic emission produced during the inspiral and merger of supermassive black holes when these are immersed in a force-free plasma threaded by a uniform magnetic field. As anticipated in a recent letter, our results show that although a dual-jet structure is present, the associated luminosity is ~100 times smaller than the total one, which is predominantly quadrupolar. Here we discuss the details of our implementation of the equations in which the force-free condition is not implemented at a discrete level, but rather obtained via a damping scheme which drives the solution to satisfy the correct condition. We show that this is important for a correct and accurate description of the current sheets that can develop in the course of the simulation. We also study in greater detail the three-dimensional charge distribution produced as a consequence of the inspiral and show that during the inspiral it possesses a complex but ordered structure which traces the motion of the two black holes. Finally, we provide quantitative estimates of the scaling of the electromagnetic emission with frequency, with the diffused part having a dependence that is the same as the gravitational-wave one and that scales as L^(non-coll)_(EM) ≈ Ω^((10/3)–(8/3)), while the collimated one scales as L^(coll)_(EM) ≈ Ω^((5/3)–(6/3)), thus with a steeper dependence than previously estimated. We discuss the impact of these results on the potential detectability of dual jets from supermassive black holes and the steps necessary for more accurate estimates

Nurse Schedule Evaluation through Simulation with integrated Rescheduling

Nurse scheduling is a complex planning task in which many constraints, e.g. meeting the required demand or considering employees’ satisfaction, are considered. However, employee absences due to uncertain events require rescheduling of former planned optimal schedules, which is often impossible without exceeding some of previous assumed limitations. Within this paper, we evaluate the ability of planned schedules to react to changes during the planning horizon. We present a discrete event-driven simulation system to emulate shifts and assignment of nurses and include real-world data schedules as well as different rescheduling strategies, which address staff shortage. To gain insights in the schedules’ practicability, their effects regarding employee satisfaction, extra hours and additional costs are evaluated. First numerical experiments show that it is hard to find any substitution in case of an unforeseen absence. Thus, rescheduling with constraint relaxation generates significantly better results regarding the use of temporary staff and costs

The Effect of Language on Economic Behavior: Experimental Evidence from Children's Intertemporal Choices

According to Chen’s (2013) linguistic-savings hypothesis, languages which grammatically separate the future and the present (like English or Italian) induce less future-oriented behavior than languages in which speakers can refer to the future by using present tense (like German). We complement Chen’s approach with experimentally elicited time preference data from a bilingual city in Northern Italy. We find that German-speaking primary school children are about 46% more likely than Italian-speaking children to delay gratification in an intertemporal choice experiment. This result is robust when controlling for risk attitudes, IQ, family background, or when considering other languages

Auditory verbal hallucinations: imaging, analysis, and intervention

In this article, we will link neuroimaging, data analysis, and intervention methods in an important psychiatric condition: auditory verbal hallucinations (AVH). The clinical and phenomenological background as well as neurophysiological findings will be covered and discussed with respect to noninvasive brain stimulation. Additionally, methods of noninvasive brain stimulation will be presented as ways to intervene with AVH. Finally, preliminary conclusions and possible future perspectives will be propose

Quantum Rate-Distortion Coding of Relevant Information

IEEE Rate-distortion theory provides bounds for compressing data produced by an information source to a specified encoding rate that is strictly less than the sourceand#x2019;s entropy. This necessarily entails some loss, or distortion, between the original source data and the best approximation after decompression. The so-called Information Bottleneck Method is designed to compress only and#x2018;relevantand#x2019; information. Which information is relevant is determined by the correlation between the data being compressed and a variable of interest, so-called side information. In this paper, an Information Bottleneck Method is introduced for the compression of quantum data. The channel communication picture is used for compression and decompression. The rate of compression is derived using an entanglement assisted protocol with classical communication, and under an unproved conjecture that the rate function is convex in the distortion parameter. The optimum channel achieving this rate for a given input state is characterised. The conceptual difficulties arising due to differences in the mathematical formalism between quantum and classical probability theory are discussed and solutions are presented

Immunostaining for the tumour suppressor gene p16 product is a useful marker to differentiate melanoma metastasis from lymph-node nevus

Upon the introduction of extensive sampling protocols of sentinel node biopsies, pathologists are increasingly confronted with small melanoma metastases. Using conventional histology, it proves sometimes difficult or impossible to differentiate small melanoma metastases from lymph-node nevi. Loss of the tumour suppressor gene p16 has been shown to be associated with tumour progression of melanoma. We investigated nevus and melanoma cells for the presence of the product of the gene p16, using immunohistochemistry. All nevus cells, independent of their location (nodal or skin) displayed an extensive nuclear and cytoplasmic staining for p16. In contrast, all cells of melanoma metastases, except one skin metastasis, lacked nuclear staining for p16. These findings indicate that p16 is a reliable marker to distinguish lymph-node nevi from melanoma metastasi

Children's cooperation and discrimination in a bilingual province

While discrimination and its economic implications have been studied in many different societies and based on a multitude of attributes like ethnicity, religion, gender, or language, the development of such behavior in children is still poorly understood. Here we present experimental evidence from a bilingual city in Northern Italy on whether the language spoken by a partner in a prisoner s dilemma game affects behavior. We examine how discrimination based on language develops in practically all six- to eleven-year old primary school children in the city. We find that cooperation increases with age and that both in-group favoritism and out-group discrimination emerge as children get older

The Effect of Language on Economic Behavior: Experimental Evidence from Children's Intertemporal Choices

According to Chen's (2013) linguistic-savings hypothesis, languages which grammatically separate the future and the present (like English or Italian) induce less future-oriented behavior than languages in which speakers can refer to the future by using present tense (like German). We complement Chen's approach with experimentally elicited time preference data from a bilingual city in Northern Italy. We find that German-speaking primary school children are about 46% more likely than Italian-speaking children to delay gratification in an intertemporal choice experiment. The difference remains significant in several robustness checks and when controlling for a broad range of factors, including risk attitudes, IQ or family background