The intestinal lymphatic system: Functions and metabolic implications

The lymphatic system of the gut plays important roles in the transport of dietary lipids, as well as in immunosurveillance and removal of interstitial fluid. Historically, despite its crucial functions in intestinal homeostasis, the lymphatic system has been poorly studied. In the last 2 decades, identification of specific molecular mediators of lymphatic endothelial cells (LECs) growth together with novel genetic approaches and intravital imaging techniques, have advanced our understanding of the mechanisms regulating intestinal lymphatic physiology in health and disease. As its metabolic implications are gaining recognition, intestinal lymphatic biology is currently experiencing a surge in interest. This review describes current knowledge related to molecular control of intestinal lymphatic vessel structure and function. We discuss regulation of chylomicron entry into lymphatic vessels by vascular endothelial growth factors (VEGFs), hormones, transcription factors and the specific signaling pathways involved. The information covered supports the emerging role of intestinal lymphatics in etiology of the metabolic syndrome and their potential as a therapeutic target. Keywords: Lacteals, Lipid, VEGF Signaling, Endothelium, Obesit

The buffer stock model redux? An analysis of the dynamics of foreign reserve accumulation

Emerging market economies have recently accumulated large stocks of foreign reserves. In this paper we address the question of what are the main factors accounting for reserve holdings in nine developing countries located in Asia and Latin America. Monthly data from January 1985 to May 2006 are used to estimate for each country the long run equilibrium reserve demand, based on the buffer stock model, the short run dynamics governing the process of reserve accumulation (decumulation) and the factors which may influence the speed of adjustment of actual to desired reserves. Cointegration analysis suggests that the buffer stock precautionary model accounts for the optimal reserve demand. The corresponding VECMs are further interpolated, using the permanent and transitory innovations decomposition procedure of Gonzalo and Ng (2001), in order to assess the relative impact of the time series on the convergence to equilibrium after a shock. Finally the (asymmetric) effect on the speed of convergence of positive/negative changes in signal variables - such as the excess reserves of the previous period, relative competitiveness and US monetary stance - is found to be significant, in line with mercantilistic and fear of floating motives for hoarding international reserves.Emerging markets reserves, cointegration, P-T components decomposition, asymmetric adjustment

Oil price Dynamics and Speculation. A Multivariate Financial Approach

This paper assesses empirically whether speculation affects oil price dynamics. The growing presence of financial operators in the oil markets has led to the diffusion of trading techniques based on extrapolative expectations. Strategies of this kind foster feedback trading that may cause large departures of prices from their fundamental values. We investigate this hypothesis using a modified CAPM that follows Shiller (1984) and Sentana and Wadhwani (1992). At first, a univariate GARCH(1,1)-M is estimated assuming that the risk premium is a function of the conditional oil price volatility. The single factor model, however, is outperformed by the multifactor ICAPM (Merton, 1973) which takes into account a larger investment opportunity set. The analysis is then carried out using a trivariate CCC GARCH-M model with complex nonlinear conditional mean equations where oil price dynamics are associated with both stock market and exchange rate behavior. We find strong evidence that oil price shifts are negatively related to stock price and exchange rate changes and that a complex web of time varying first and second order conditional moment interactions affect both the CAPM and feedback trading components of the model. Despite the difficulties, we identify a significant role of speculation in the oil market which is consistent with the observed large daily upward and downward shifts in prices. A clear evidence that it is not a fundamentals-driven market. Thus, from a policy point of view - given the impact of volatile oil prices on global inflation and growth - actions that monitor more effectively speculative activities on commodity markets are to be welcomed.oil price dynamics; feedback trading; speculation; multivariate GARCH-M

Frequentistic approximations to Bayesian prevision of exchangeable random elements

Given a sequence \xi_1, \xi_2,... of X-valued, exchangeable random elements, let q(\xi^(n)) and p_m(\xi^(n)) stand for posterior and predictive distribution, respectively, given \xi^(n) = (\xi_1,..., \xi_n). We provide an upper bound for limsup b_n d_[[X]](q(\xi^(n)), \delta_\empiricn) and limsup b_n d_[X^m](p_m(\xi^(n)), \empiricn^m), where \empiricn is the empirical measure, b_n is a suitable sequence of positive numbers increasing to +\infty, d_[[X]] and d_[X^m] denote distinguished weak probability distances on [[X]] and [X^m], respectively, with the proviso that [S] denotes the space of all probability measures on S. A characteristic feature of our work is that the aforesaid bounds are established under the law of the \xi_n's, unlike the more common literature on Bayesian consistency, where they are studied with respect to product measures (p_0)^\infty, as p_0 varies among the admissible determinations of a random probability measure

Weighted K-stability for a class of non-compact toric fibrations

We study the weighted constant scalar curvature, a modified scalar curvature introduced by Lahdili depending on weight functions $(v, w)$, on certain non-compact semisimple toric fibrations, a generalization of the Calabi Ansatz defined by Apostolov--Calderbank--Gauduchon--T{\o}nnesen-Friedman. We show that the natural analog of the weighted Futaki invariant of Lahdili can under reasonable assumptions be interpreted on an unbounded polyhedron $P \subset \mathbb{R}^n$ associated to $M$. In particular, we fix a certain class $\mathcal{W}$ of weights $(v, w)$, and prove that if $M$ admits a weighted cscK metric, then $P$ is K-stable, and we give examples of weights on $\mathbb{C}^2$ for which the weighted Futaki invariant vanishes but do not admit $(v, w)$-cscK metrics. Following Jubert, we introduce a weighted Mabuchi energy $\mathcal{M}_{v,w}$ and show that the existence of a $(v, w)$-cscK metric implies that it $\mathcal{M}_{v,w}$ proper, and prove a uniqueness result using the method of Guan. We show that weighted K-stability of the abstract fiber $\mathbb{C}$ is sufficient for the existence of weighted cscK metrics on the total space of line bundles $L \rightarrow B$ over a compact K\"ahler base, extending a result of Lahdili in the $\mathbb{P}^1$-bundles case. The right choice of weights corresponds to the (shrinking) K\"ahler-Ricci soliton equation, and we give an interpretation of the asyptotic geometry in this case.Comment: Added Corollary 1.3 and its proof, and other minor changes, as per the suggestion of the referee. Final version, to appear in J. Geom. Ana

The Sociology of Music and Social Distinctions: P!NK\u27s Career as an Example of Social Linkage

The purpose of this study is to examine musician’s potential to conduct positive social change because of their ability to connect multiple social distinctions. This study will highlight a number of social distinctions that musicians encounter throughout their career and how they either become well-placed individuals through the linkage of these distinctions, or link social distinctions due to their power status. In addition, this study is meant to stand as a testament to the power of musicians and music to conduct effective social change through active and creative means versus those of other well-placed individuals in society, for example politicians, actors, authors or even activists. Furthermore, this study focuses on the career of a musician who has been labeled as a “trailblazer” and “music outsider” due to her unapologetic behavior and work. This artist also takes very uncustomary routes for conducting change and is still a contemporary voice involved with social activism. For these reasons, including the number of social distinctions encountered in her career, this artist was chosen to be a centerpiece of the explanation concerning musicians and social change. In this study, the artist whose career serves as an example of the linkage of social distinctions is known as Alecia Beth Moore, or P!NK to the entertainment world. Portions of the study will also explain how P!NK differs from similar artists in the music industry and their capacity to conduct social change