Fair Artificial Currency Incentives in Repeated Weighted Congestion Games: Equity vs. Equality

When users access shared resources in a selfish manner, the resulting societal cost and perceived users' cost is often higher than what would result from a centrally coordinated optimal allocation. While several contributions in mechanism design manage to steer the aggregate users choices to the desired optimum by using monetary tolls, such approaches bear the inherent drawback of discriminating against users with a lower income. More recently, incentive schemes based on artificial currencies have been studied with the goal of achieving a system-optimal resource allocation that is also fair. In this resource-sharing context, this paper focuses on repeated weighted congestion game with two resources, where users contribute to the congestion to different extents that are captured by individual weights. First, we address the broad concept of fairness by providing a rigorous mathematical characterization of the distinct societal metrics of equity and equality, i.e., the concepts of providing equal outcomes and equal opportunities, respectively. Second, we devise weight-dependent and time-invariant optimal pricing policies to maximize equity and equality, and prove convergence of the aggregate user choices to the system-optimum. In our framework it is always possible to achieve system-optimal allocations with perfect equity, while the maximum equality that can be reached may not be perfect, which is also shown via numerical simulations

Urgency-aware Optimal Routing in Repeated Games through Artificial Currencies

When people choose routes minimizing their individual delay, the aggregate congestion can be much higher compared to that experienced by a centrally-imposed routing. Yet centralized routing is incompatible with the presence of self-interested agents. How can we reconcile the two? In this paper we address this question within a repeated game framework and propose a fair incentive mechanism based on artificial currencies that routes selfish agents in a system-optimal fashion, while accounting for their temporal preferences. We instantiate the framework in a parallel-network whereby agents commute repeatedly (e.g., daily) from a common start node to the end node. Thereafter, we focus on the specific two-arcs case whereby, based on an artificial currency, the agents are charged when traveling on the first, fast arc, whilst they are rewarded when traveling on the second, slower arc. We assume the agents to be rational and model their choices through a game where each agent aims at minimizing a combination of today's discomfort, weighted by their urgency, and the average discomfort encountered for the rest of the period (e.g., a week). We show that, if prices of artificial currencies are judiciously chosen, the routing pattern converges to a system-optimal solution, while accommodating the agents' urgency. We complement our study through numerical simulations. Our results show that it is possible to achieve a system-optimal solution whilst reducing the agents' perceived discomfort by 14-20% when compared to a centralized optimal but urgency-unaware policy.Comment: Accepted for presentation at the European Control Conference 202

Urgency-aware optimal routing in repeated games through artificial currencies

When people choose routes minimizing their individual delay, the aggregate congestion can be much higher compared to that experienced by a centrally-imposed routing. Yet centralized routing is incompatible with the presence of self-interested users. How can we reconcile the two? In this paper we address this question within a repeated game framework and propose a fair incentive mechanism based on artificial currencies that routes selfish users in a system-optimal fashion, while accounting for their temporal preferences. We instantiate the framework in a parallel-network whereby users commute repeatedly (e.g., daily) from a common start node to the end node. Thereafter, we focus on the specific two-arcs case whereby, based on an artificial currency, the users are charged when traveling on the first, fast arc, whilst they are rewarded when traveling on the second, slower arc. We assume the users to be rational and model their choices through a game where each user aims at minimizing a combination of today's discomfort, weighted by their urgency, and the average discomfort encountered for the rest of the period (e.g., a week). We show that, if prices of artificial currencies are judiciously chosen, the routing pattern converges to a system-optimal solution, while accommodating the users’ urgency. We complement our study through numerical simulations. Our results show that it is possible to achieve a system-optimal solution whilst significantly reducing the users’ perceived discomfort when compared to a centralized optimal but urgency-unaware policy

The Colored Hofstadter Butterfly for the Honeycomb Lattice

We rely on a recent method for determining edge spectra and we use it to compute the Chern numbers for Hofstadter models on the honeycomb lattice having rational magnetic flux per unit cell. Based on the bulk-edge correspondence, the Chern number $$\sigma _\mathrm{H}$$ σ H is given as the winding number of an eigenvector of a $$2 \times 2$$ 2 × 2 transfer matrix, as a function of the quasi-momentum $$k\in (0,2\pi )$$ k ∈ ( 0 , 2 π ) . This method is computationally efficient (of order $$\mathcal {O}(n^4)$$ O ( n 4 ) in the resolution of the desired image). It also shows that for the honeycomb lattice the solution for $$\sigma _\mathrm{H}$$ σ H for flux $$p/q$$ p / q in the $$r$$ r -th gap conforms with the Diophantine equation $$r=\sigma _\mathrm{H}\cdot p+ s\cdot q$$ r = σ H · p + s · q , which determines $$\sigma _\mathrm{H}\mod q$$ σ H mod q . A window such as $$\sigma _\mathrm{H}\in (-q/2,q/2)$$ σ H ∈ ( - q / 2 , q / 2 ) , or possibly shifted, provides a natural further condition for $$\sigma _\mathrm{H}$$ σ H , which however turns out not to be met. Based on extensive numerical calculations, we conjecture that the solution conforms with the relaxed condition $$\sigma _\mathrm{H}\in (-q,q)$$ σ H ∈ ( - q , q )

Realism and the wave-function

Realism -- the idea that the concepts in physical theories refer to 'things' existing in the real world -- is introduced as a tool to analyze the status of the wave-function. Although the physical entities are recognized by the existence of invariant quantities, examples from classical and quantum physics suggest that not all the theoretical terms refer to the entities: some terms refer to properties of the entities, and some terms have only an epistemic function. In particular, it is argued that the wave-function may be written in terms of classical non-referring and epistemic terms. The implications for realist interpretations of quantum mechanics and on the teaching of quantum physics are examined.Comment: No figure

Is there a role for ‘modified VAD’ in the treatment of multiple myeloma?

VAD, (Vincristine, Doxorubicin and Dexamethasone) was initially proposed as a salvage therapy for myeloma patients in whom prior alkylating agent therapy failed, although in recent years VAD has been surpassed by novel combination therapies with new biological agents such as thalidomide (and its derivative, lenalidomide) and bortezomib. After the excellent results obtained by the novel agents, VAD can no longer be proposed in preparation to autologous transplantation, although there are still indications that VAD remains useful and clinically relevant in the initial treatment of symptomatic multiple myeloma

Effects of EPA and DHA on lipid droplet accumulation and mRNA abundance of PAT proteins in caprine monocytes

The present study investigated the in vitro effects on caprine monocytes of two \u3c9-3 PUFAs, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on lipid droplet formation, an emerging process of fundamental importance in innate immunity regulation. The mRNA abundance of PAT protein family (PLIN1, PLIN2 and PLIN3), involved in the formation and trafficking of the droplets, was also assessed. The effects of EPA and DHA on monocyte apoptosis were studied as well. The number of lipid droplets per cell was found to be dependent on both type and concentration of fatty acid. \u3c9-3 PUFAs upregulated PLIN3 and PLIN2 gene expression, as well as apoptosis rate. The present findings suggest that PUFA might modify innate immune functions of goat monocytes by interfering with the formation of lipid droplets and by upregulating proteins belonging to PAT protein family

O conceito de “Dispositivo universal” (Universalapparat) em Günther Anders

Encontra-se em curso, sensivelmente no último meio século, a finalização de um processo de planetarização da Tecnologia, que, na ordem das causas, terá sido mais proximamente determinado pela Globalização político-económica urdida e imposta pelo Neoliberalismo e mais remotamente influenciado por sucessivas revoluções industriais, desde o século XVIII. Ele implicou uma transformação na própria natureza da Tecnologia, fazendo com que deixasse de ser mero meio (utensílio, ferramenta, instrumento) para determinados fins e se tivesse tornado num ambiente vital e existencial. Günther Anders foi um atento e perspicaz observador e crítico desse fenómeno, que, no seu jargão, concebeu como o do advento de um “Dispositivo universal” (Universalapparat). Dedica-se a primeira parte deste artigo à releitura da interpretação que esse filósofo alemão fez da sua suposta génese e evolução. Na segunda parte, analisa-se esse conceito. Explora-se, na terceira parte, duas consequências filosóficas maiores desse fenómeno.More or less in the last half century, a process of planetarization of Technology is underway, which in the order of causes will have been more directly determined by the politicaleconomic Globalization woven and imposed by the so-called Neoliberalism and more remotely influenced by successive industrial revolutions since the 18th century. It implied a transformation in the nature of Technology, ceasing to be a mere means (utensil, tool, instrument) for certain purposes and becoming a vital and existential environment. Günther Anders was an attentive, perceptive and critical observer of this phenomenon that, in his jargon, he conceived as the advent of a “Universal apparatus” (Universalapparat). I dedicate the first part of this article to reread the German philosopher’s interpretation of his supposed genesis and evolution. In the second part, I analyze this concept. In the third part, I explore two main philosophical consequences of this phenomenon

Chronic Citalopram Administration Causes a Sustained Suppression of Serotonin Synthesis in the Mouse Forebrain

BACKGROUND:Serotonin (5-HT) is a neurotransmitter with important roles in the regulation of neurobehavioral processes, particularly those regulating affect in humans. Drugs that potentiate serotonergic neurotransmission by selectively inhibiting the reuptake of serotonin (SSRIs) are widely used for the treatment of psychiatric disorders. Although the regulation of serotonin synthesis may be an factor in SSRI efficacy, the effect of chronic SSRI administration on 5-HT synthesis is not well understood. Here, we describe effects of chronic administration of the SSRI citalopram (CIT) on 5-HT synthesis and content in the mouse forebrain. METHODOLOGY/PRINCIPAL FINDINGS:Citalopram was administered continuously to adult male C57BL/6J mice via osmotic minipump for 2 days, 14 days or 28 days. Plasma citalopram levels were found to be within the clinical range. 5-HT synthesis was assessed using the decarboxylase inhibition method. Citalopram administration caused a suppression of 5-HT synthesis at all time points. CIT treatment also caused a reduction in forebrain 5-HIAA content. Following chronic CIT treatment, forebrain 5-HT stores were more sensitive to the depleting effects of acute decarboxylase inhibition. CONCLUSIONS/SIGNIFICANCE:Taken together, these results demonstrate that chronic citalopram administration causes a sustained suppression of serotonin synthesis in the mouse forebrain. Furthermore, our results indicate that chronic 5-HT reuptake inhibition renders 5-HT brain stores more sensitive to alterations in serotonin synthesis. These results suggest that the regulation of 5-HT synthesis warrants consideration in efforts to develop novel antidepressant strategies