On the orientation and magnitude of the black hole spin in galactic nuclei

Massive black holes in galactic nuclei vary their mass M and spin vector J due to accretion. In this study we relax, for the first time, the assumption that accretion can be either chaotic, i.e. when the accretion episodes are randomly and isotropically oriented, or coherent, i.e. when they occur all in a preferred plane. Instead, we consider different degrees of anisotropy in the fueling, never confining to accretion events on a fixed direction. We follow the black hole growth evolving contemporarily mass, spin modulus a and spin direction. We discover the occurrence of two regimes. An early phase (M <~ 10 million solar masses) in which rapid alignment of the black hole spin direction to the disk angular momentum in each single episode leads to erratic changes in the black hole spin orientation and at the same time to large spins (a ~ 0.8). A second phase starts when the black hole mass increases above >~ 10 million solar masses and the accretion disks carry less mass and angular momentum relatively to the hole. In the absence of a preferential direction the black holes tend to spin-down in this phase. However, when a modest degree of anisotropy in the fueling process (still far from being coherent) is present, the black hole spin can increase up to a ~ 1 for very massive black holes (M >~ 100 million solar masses), and its direction is stable over the many accretion cycles. We discuss the implications that our results have in the realm of the observations of black hole spin and jet orientations.Comment: 14 pages, 7 figures, accepted for publication in Ap

Casein phosphopeptides : from milk to nutraceutical

Milk and dairy products are known sources of bioavailable calcium for its association with casein, whose proteolysis produces caseinphosphopeptides (CPPs). CPPs are phosphorylated peptides able to bind and solubilise calcium. In human intestinal tumor cells differentiated in vitro toward an enterocityc phenotype, they also induce a calcium uptake. Moreover, in human in vitro osteoblasts, CPPs favour the mineralization of the extracellular matrix. CPPs can differently affect proliferation and apoptosis in differentiated and /or tumor intestinal cells. Due to all these properties, CPPs may be considered as potential nutraceutical/functional food

Neutrino processes in partially degenerate neutron matter

We investigate neutrino processes for conditions reached in simulations of core-collapse supernovae. Where neutrino-matter interactions play an important role, matter is partially degenerate, and we extend earlier work that addressed the degenerate regime. We derive expressions for the spin structure factor in neutron matter, which is a key quantity required for evaluating rates of neutrino processes. We show that, for essentially all conditions encountered in the post-bounce phase of core-collapse supernovae, it is a very good approximation to calculate the spin relaxation rates in the nondegenerate limit. We calculate spin relaxation rates based on chiral effective field theory interactions and find that they are typically a factor of two smaller than those obtained using the standard one-pion-exchange interaction alone.Comment: 41 pages, 9 figures, NORDITA-2011-116; added comparison figures and fit function for use in simulations, to appear in Astrophys.

The impact of Universal Health Coverage on healthcare consumption and risky behaviours: evidence from Thailand

Thailand is among one of the first non OECD countries to have successfully introduced a form of Universal Health Coverage (UHC) in 2002. This policy defines a natural experiment for the evaluation of the effects of public health insurance on health behaviours. In the present paper, we look at the impact of the Thai UHC on preventive activities, risky behaviours and healthcare consumption using data from the 1996, 2001 and 2003 Health and Welfare Survey of Thailand. We use double robust estimators combining propensity scores and linear regressions to estimate Difference-in-Differences (DD) and Difference in DD (DDD) models. Results offer important insights. First, previously uninsured men and women increased their preventive activities (check-ups) more than any other groups. At the same time, there is no evidence of either an increase in risky behaviours or a reduction of preventive efforts by the newly insured population. In other words, we find no evidence of ex ante moral hazard. Regarding healthcare consumption, we see that hospital admissions increased by 2% and outpatient visits increased by 13% due to the UHC. Overall, these findings imply positive health impacts among the Thai population who entered in the UHC

Dubbing versus subtitling in young and older adults: cognitive and evaluative aspects

Empirical evidence about the cognitive and evaluative consequences of viewing a dubbed vs. a subtitled film is scarce, theoretical views on the subject are mainly speculative and age-related differences have not been investigated within this comparison. To fill these gaps, we carried out two studies contrasting the consequences of viewing a dubbed vs. subtitled version of the same film excerpt in young and older adults, using a comprehensive array of verbal and visual measures. The findings clearly show that dubbing does not provide a cognitive or evaluative advantage over subtitling. Moreover, subtitling seems to be more effective than dubbing in supporting the lexical aspects of performance. Finally, although older adults always had a worse performance than young adults on all cognitive measures, they did not show a specific impairment in the subtitling condition. The results support the view that subtitled films are processed effectively and appreciated at least as much by both young and older adults

GAM Forest Explanation

Most accurate machine learning models unfortunately produce black-box predictions, for which it is impossible to grasp the internal logic that leads to a specific decision. Unfolding the logic of such black-box models is of increasing importance, especially when they are used in sensitive decision-making processes. In this work we focus on forests of decision trees, which may include hundreds to thousands of decision trees to produce accurate predictions. Such complexity raises the need of developing explanations for the predictions generated by large forests. We propose a post hoc explanation method of large forests, named GAM-based Explanation of Forests (GEF), which builds a Generalized Additive Model (GAM) able to explain, both locally and globally, the impact on the predictions of a limited set of features and feature interactions. We evaluate GEF over both synthetic and real-world datasets and show that GEF can create a GAM model with high fidelity by analyzing the given forest only and without using any further information, not even the initial training dataset

INTERACTION OF CASEIN PHOSPHOPEPTIDES WITH CHANNELS INVOLVED IN CALCIUM ABSORPTION AND MODULATION OF PROLIFERATION RATE AND APOPTOSIS OF HUMAN INTESTINAL CELL LINES

Recent studies have evidenced that dietary calcium is able to exert a chemoprotective role on normal differentiated intestinal cells, while it behaves as a carcinogenesis promoter on aberrant colonocytes and adenomatous crypts. These different functions can be achieved through the modulation of proliferation and/or differentiation processes, triggered by the increase of the calcium ion concentrations in the intestinal lumen after a meal. Milk represents the major source of calcium in the diet, due to the high availability of the mineral bound to casein and casein phosphopeptides (CPPs). CPPs, derived by in vitro or in vivo casein hydrolysis, are able to bind calcium, blocking the mineral precipitation in the presence of phosphate and /or sulphate salts and to induce a calcium uptake in human intestinal tumor cell lines HT-29 and Caco2 differentiated in vitro toward an enterocityc phenotype. Thus the hypothesis that CPPs could differently affect proliferation and apoptosis in undifferentiated and differentiated HT-29 and Caco2 cells through their binding with calcium ions was here investigated. Results showed that in HT-29 cells CPPs protect differentiated cells from calcium overload toxicity, prevent their apoptosis, favoring proliferation, while in undifferentiated, tumor like, cells they induce apoptosis. The mechanism by which CPPs act in HT-29 cells is mainly the modulation of the voltage operated L-type calcium channels, known to activate calcium entry into the cells under depolarization, a situation occurring after a meal, and to exert a mitogenic effect. The L-type calcium channels have been now recognized to represent one of the two transcellular calcium absorption ways, characterized by the location in the distal ileum and the independence of vitamin D control. In Caco2 cells, CPPs did not significantly affect proliferation, while increase apoptosis in undifferentiated, tumor like, cells. The mechanism by which CPPs act in Caco2 cells is mainly through the TRPV6 channel, known as the main epithelial channel responsible for the transcellular calcium absorption at duodenum level, subject to vitamin D control and with a saturation kinetic for calcium. Taken together these results demonstrate the ability for CPPs, to modulate the two principal transcellular calcium absorption mechanisms. Moreover, through the binding with calcium ions and the stimulated ingression of this mineral in intestinal cells, CPPs can directly modulate the biological activity strictly related to the expression of a normal or cancer phenotype, thus opening the way for a use of CPPs as nutraceutical/functional food