Effects of group singing on well-being: empirical findings and methodological considerations

The work in this thesis explores the relationship between singing and well-being. In particular, I focus on investigating the potential for group singing to promote feelings of hedonic, eudaimonic and social well-being. The theoretical evidence suggests that such is possible because music activities are structured to engage mind and body in overcoming a challenge, generating feelings of achievement and pleasure in the process. However, the empirical evidence on such effects is less conclusive, reflecting the novelty of the field. I start by developing a model capable of generating hypotheses and framing the empirical work on the relationship between group singing and well-being. In this model, I integrate a conceptualization of well-being as a multidimensional concept with a conceptualization of group singing as a challenging multifaceted activity. The model suggests that well-being is promoted by group singing through the effects this activity has on its psychological, bodily and social correlates. However, the model also accounts for possible moderating effects of situational factors and individual differences. My empirical work focus first on clarifying that group singing involves the types of experiences that can generate feelings of hedonic, eudaimonic and social well-being. I then show that singing in a group relates to long-term measures of well-being, particularly social and eudaimonic. In the short-term, group singing is also consistently related to correlates of well-being. It is shown to increase positive affect, decrease negative affect, increase feelings of achievement and connection to others. Situational factors such as the social context in which the singing occurs are shown to have a moderating effect on endocrine effects of group singing. However, gender differences do not emerge. I also show that group singing can have effects over and above those of a similar, though non-musical, group activity. Overall, the evidence suggests a meaningful relationship between group singing and well-being

Non-Gaussian statistics, maxwellian derivation and stellar polytropes

In this letter we discuss the Non-gaussian statistics considering two aspects. In the first, we show that the Maxwell's first derivation of the stationary distribution function for a dilute gas can be extended in the context of Kaniadakis statistics. The second one, by investigating the stellar system, we study the Kaniadakis analytical relation between the entropic parameter $\kappa$ and stellar polytrope index $n$. We compare also the Kaniadakis relation $n=n(\kappa)$ with $n=n(q)$ proposed in the Tsallis framework.Comment: 10 pages, 1 figur

Revenue recycling and the welfare effects of road pricing

The authors explore the interaction between taxes on work-related traffic congestion and preexisting distortionary taxes in the labor market. A congestion tax raises the overall costs of commuting to work and discourages labor force participation at the margin when revenues are returned in lump-sum transfers. The resulting efficiency loss in the labor market can be larger that the Pigouvian efficiency gains from internalizing the congestion externality. By contrast, if congestion tax revenues are used to reduce labor taxes, the net impact on the labor supply is positive and the efficiency gain in the labor market can raise the overall welfare gains of the congestion tax by as much as 100 percent. Recycling congestion tax revenues in public transit subsidies produces a positive, but smaller, impact on the labor supply. In short, the authors'results indicate that the presence of preexisting tax distortions, and the form of revenue recycling, can crucially affect the size - and possibly even the sign - of the welfare effect of road pricing schemes. The efficiency gains from recycling congestion tax revenues in other tax reductions can amount to several times the Pigouvian welfare gains from congestion reduction.Public Sector Economics&Finance,Economic Theory&Research,Labor Policies,Environmental Economics&Policies,Banks&Banking Reform,Environmental Economics&Policies,Public Sector Economics&Finance,Economic Theory&Research,Banks&Banking Reform,Municipal Financial Management

Adaptive Cluster Expansion for Inferring Boltzmann Machines with Noisy Data

We introduce a procedure to infer the interactions among a set of binary variables, based on their sampled frequencies and pairwise correlations. The algorithm builds the clusters of variables contributing most to the entropy of the inferred Ising model, and rejects the small contributions due to the sampling noise. Our procedure successfully recovers benchmark Ising models even at criticality and in the low temperature phase, and is applied to neurobiological data.Comment: Accepted for publication in Physical Review Letters (2011

Brane Cosmology from Heterotic String Theory

We consider brane cosmologies within the context of five-dimensional actions with O(a') higher curvature corrections. The actions are compatible with bulk string amplitude calculations from heterotic string theory. We find wrapped solutions that satisfy the field equations in an approximate but acceptable manner given their complexity, where the internal four-dimensional scale factor is naturally inflating, having an exponential De-Sitter form. The temporal dependence of the metric components is non-trivial so that this metric cannot be factored as in a conformally flat case. The effective Planck mass is finite and the brane solutions localize four-dimensional gravity, while the four-dimensional gravitational constant varies with time. The Hubble constant can be freely specified through the initial value of the scalar field, to conform with recent data.Comment: 15 pages, 3 figures, LaTeX, Accepted for Publication in IJT

A Curvature Principle for the interaction between universes

We propose a Curvature Principle to describe the dynamics of interacting universes in a multi-universe scenario and show, in the context of a simplified model, how interaction drives the cosmological constant of one of the universes toward a vanishingly small value. We also conjecture on how the proposed Curvature Principle suggests a solution for the entropy paradox of a universe where the cosmological constant vanishes.Comment: Essay selected for an honorable mention by the Gravity Research Foundation, 2007. Plain latex, 8 page

Variação linguística e aprendizagem da leitura

Apresentam-se os resultados de investigações realizadas sobre a influência do meio linguístico na aprendizagem da língua escrita