Feeding Stimulates Sphingosine-1-Phosphate Mobilization in Mouse Hypothalamus.

Previous studies have shown that the sphingolipid-derived mediator sphingosine-1-phosphate (S1P) reduces food intake by activating G protein-coupled S1P receptor-1 (S1PR1) in the hypothalamus. Here, we examined whether feeding regulates hypothalamic mobilization of S1P and other sphingolipid-derived messengers. We prepared lipid extracts from the hypothalamus of C57Bl6/J male mice subjected to one of four conditions: free feeding, 12 h fasting, and 1 h or 6 h refeeding. Liquid chromatography/tandem mass spectrometry was used to quantify various sphingolipid species, including sphinganine (SA), sphingosine (SO), and their bioactive derivatives SA-1-phosphate (SA1P) and S1P. In parallel experiments, transcription of S1PR1 (encoded in mice by the S1pr1 gene) and of key genes of sphingolipid metabolism (Sptlc2, Lass1, Sphk1, Sphk2) was measured by RT-PCR. Feeding increased levels of S1P (in pmol-mg-1 of wet tissue) and SA1P. This response was accompanied by parallel changes in SA and dihydroceramide (d18:0/18:0), and was partially (SA1P) or completely (S1P) reversed by fasting. No such effects were observed with other sphingolipid species targeted by our analysis. Feeding also increased transcription of Sptlc2, Lass1, Sphk2, and S1pr1. Feeding stimulates mobilization of endogenous S1PR1 agonists S1P and SA1P in mouse hypothalamus, via a mechanism that involves transcriptional up-regulation of de novo sphingolipid biosynthesis. The results support a role for sphingolipid-mediated signaling in the central control of energy balance

Horava Gravity in the Effective Field Theory formalism: from cosmology to observational constraints

We consider Horava gravity within the framework of the effective field theory (EFT) of dark energy and modified gravity. We work out a complete mapping of the theory into the EFT language for an action including all the operators which are relevant for linear perturbations with up to sixth order spatial derivatives. We then employ an updated version of the EFTCAMB/EFTCosmoMC package to study the cosmology of the low-energy limit of Horava gravity and place constraints on its parameters using several cosmological data sets. In particular we use cosmic microwave background (CMB) temperature-temperature and lensing power spectra by Planck 2013, WMAP low-l polarization spectra, WiggleZ galaxy power spectrum, local Hubble measurements, Supernovae data from SNLS, SDSS and HST and the baryon acoustic oscillations measurements from BOSS, SDSS and 6dFGS. We get improved upper bounds, with respect to those from Big Bang Nucleosynthesis, on the deviation of the cosmological gravitational constant from the local Newtonian one. At the level of the background phenomenology, we find a relevant rescaling of the Hubble rate at all epoch, which has a strong impact on the cosmological observables; at the level of perturbations, we discuss in details all the relevant effects on the observables and find that in general the quasi-static approximation is not safe to describe the evolution of perturbations. Overall we find that the effects of the modifications induced by the low-energy Horava gravity action are quite dramatic and current data place tight bounds on the theory parameters.Comment: v1: 27 pages, 7 figures. v2: 28 pages, 7 figures. Changes in Figs. 2,3,4,6,7 and Tabs. 1,2. Matches published version in Phys. Dark Uni

Migrant and native interaction : labor market and marriage market

The more we study the migration phenomenon the more we understand how deep rooted in its understanding is the sentence: countries of destination thought they had let in workers and they discovered instead that they had let in human beings. Much attention is paid to the economic effects of migrants in countries of destination. But relatively little attention is paid to extremely important socio-political and demographic effects. Migration and integration policies are, also, evaluated in economic terms: do migrants increase welfare costs; do they displace native workers; do they favor economic growth etc. European researchers have neglected many key aspects of family-related migration, lagging behind, in this respect, North American and Latin American research (e.g., Boyle 2002; Falicov 2007; Glick 2010). With this policy brief, we would like to point out the multiple effects that foreign workers can have in non-economic areas. In particular, we would like to point out that a policy designed to take care, for instance, of the elderly through foreign labor can have externalities on the marriage market. Hence, a correct evaluation of a policy needs to be more comprehensive and to look at all the implications of a given decision.The MPC is co-financed by the European University Institute and the European Unio

Evaluation of railway systems: a network approach

Resilience and the efficiency of transportation systems are crucial for the economic development of geographical areas, and network analysis applied to railways can provide insight into the importance of branch lines and their impacts on the entire system. This paper explores the behavior of the ERC measure, a local robustness measure, on the railway network in Lombardy, Italy, and analyzes the impacts of deactivating stations or journeys on the network’s robustness. Changes in the topological properties of the network were studied by simulating potential external disturbances and analyzing the impact of deleting the most connected stations or railway lines. The numerical results show how the measures provided effectively identify critical stations and journeys within the network structure and outperform classical topological metrics. Since ERC measures take into account all of the alternative paths present in the network, they can provide valuable information for rerouting traffic along alternative paths in case of failures or disruptions. The paper’s original contribution lies in demonstrating the effectiveness of the ERC measure in identifying critical stations and journeys within the network structure

Female migration and native marital stability : insights from Italy

Published online: 05 May 2016Previous research has noted that divorce rates tend to be higher when there is a surplus of marriageable women in the marriage market. This paper argues that the size and the composition of the female migrant population can affect the marital stability of natives. We tested such hypothesis taking Italy as a case-study because it exemplifies a male-breadwinner society and because it is a relatively new immigration country. We estimated discrete-time event history models predicting marital disruption on data from the nationally representative 2009 Family and Social Subjects survey. Our results illustrated that the increasing presence of first mover migrant women (coming from Central-South America and Eastern Europe) is associated with higher separation risks among natives, especially for couples with lower human capital. By advancing the relevance of foreigners as a potential driver of natives’ family life courses, our findings add to our understanding of partnership dynamics in recent immigration countries

On schemes evinced by generalized additive decompositions and their regularity

We define and explicitly construct schemes evinced by generalized additive decompositions (GADs) of a given $d$-homogeneous polynomial $F$. We employ GADs to investigate the regularity of $0$-dimensional schemes apolar to $F$, focusing on those satisfying some minimality conditions. We show that irredundant schemes to $F$ need not be $d$-regular, unless they are evinced by special GADs of $F$. Instead, we prove that tangential decompositions of minimal length are always $d$-regular, as well as irredundant apolar schemes of length at most $2d+1$