Candecomp/Parafac with zero constraints at arbitrary positions in a loading matrix

When one interprets Candecomp/Parafac (CP) solutions for analyzing three-way data, small loadings are often ignored, that is, considered to be zero. Rather than just considering them zero, it seems better to actually model such values as zero. This can be done by successive modeling approaches as well as by a simultaneous modeling approach. This paper offers algorithms for three such approaches, and compares them on the basis of empirical data and a simulation study. The conclusion of the latter was that, under realistic circumstances, all approaches recovered the underlying structure well, when the number of values to constrain to zero was given. Whereas the simultaneous modeling approach seemed to perform slightly better, differences were very small and not substantial. Given that the simultaneous approach is far more time consuming than the successive approaches, the present study suggests that for practical purposes successive approaches for modeling zeros in the CP model seem to be indicated

Decision Makers Facing Uncertainty: Theory versus Evidence

This paper aims at assessing cultural differences in uncertainty attitude across Europe. We select questions from the European Values Survey (EVS) capturing salient features of uncertain scenarios ("safe versus uncertain", "freedom of choice" and "reduction of uncertainty"), and formalize these questions through simple decision-theoretic problems. We then consider three competing normative models of choice under uncertainty (subjective expected utility (SEU), maximin utility and minimax regret), and analyze how they behave when facing each decision problem. We obtain theoretical predictions and, using the EVS dataset, we test them via latent class analysis to estimate the distribution of these behaviors across EU15. We fi�nd a larger proportion of SEU maximizers (Bayesians) in northern countries than in southern countries. The opposite is true for maximin utility behavior. Only a few are consistent with minimax regret behavior.This paper aims at assessing cultural differences in uncertainty attitude across Europe. We select questions from the European Values Survey (EVS) capturing salient features of uncertain scenarios ("safe versus uncertain", "freedom of choice" and "reduction of uncertainty"), and formalize these questions through simple decision-theoretic problems. We then consider three competing normative models of choice under uncertainty (subjective expected utility (SEU), maximin utility and minimax regret), and analyze how they behave when facing each decision problem. We obtain theoretical predictions and, using the EVS dataset, we test them via latent class analysis to estimate the distribution of these behaviors across EU15. We fi�nd a larger proportion of SEU maximizers (Bayesians) in northern countries than in southern countries. The opposite is true for maximin utility behavior. Only a few are consistent with minimax regret behavior.Refereed Working Papers / of international relevanc

Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations <br>Part I: Surface fluxes

International audienceA mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer to the atmosphere is highly non-local and enhanced in the coupled simulation

Dairy bioactives and functional ingredients with skin health benefits

The potential of whey from Italian cheese productions to support skin health and anti-ageing mechanism was studied. The effect of whey on dermal and epidermal cells was evaluated. Whey inhibited the activity of elastase and tyrosinase enzymes by 60% and 32%, respectively. Whey cytotoxicity against tested skin cell lines, human fibroblasts (HDFa) and keratinocytes (HaCaT) was not observed. Moreover, the antioxidant activity of the samples was noted, after treatment with whey intracellular ROS level was decreased by 87% in comparison with the hydrogen peroxide-treated cells. Fibroblasts produced a significant amount of extracellular matrix molecules, collagen I, elastin and glycosaminoglycans as a result of treatment with tested whey. In addition, the ability of samples to improve the cell barrier integrity of keratinocytes was proven. The obtained results indicate that pure whey supports skin health and shows potential to be used by the cosmetic industry

Repetitive DNA and plant domestication: variation in copy number and proximity to genes of LTR-retrotransposons among wild and cultivated sunflower (Helianthus annuus) genotypes.

The sunflower (Helianthus annuus) genome contains a very large proportion of transposable elements, especially long terminal repeat retrotransposons. However, knowledge on the retrotransposon-related variability within this species is still limited. We used next generation sequencing technologies to perform a quantitative and qualitative survey of intraspecific variation of the retrotransposon fraction of the genome across 15 genotypes - 7 wild accessions and 8 cultivars - of H. annuus. By mapping the Illumina reads of the 15 genotypes onto a library of sunflower long terminal repeat retrotransposons, we observed considerable variability in redundancy among genotypes, at both superfamily and family levels. In another analysis we mapped Illumina paired reads to two sets of sequences, i.e. long terminal repeat retrotransposons and protein-encoding sequences, and evaluated the extent of retrotransposon proximity to genes in the sunflower genome by counting the number of paired reads in which one read mapped to a retrotransposon and the other to a gene. Large variability among genotypes was ascertained also for retrotransposon proximity to genes. Both long terminal repeat retrotransposon redundancy and proximity to genes varied among retrotransposon families and also between cultivated and wild genotypes. Such differences are discussed in relation to the possible role of long terminal repeat retrotransposons in the domestication of sunflower

Could hair-lichens of high-elevation forests help detect the impact of global change in the Alps?

Climate change and the anthropic emission of pollutants are likely to have an accelerated impact in high-elevation mountain areas. This phenomenon could have negative consequences on alpine habitats and for species of conservation in relative proximity to dense human populations. This premise implies that the crucial task is in the early detection of warning signals of ecological changes. In alpine landscapes, high-elevation forests provide a unique environment for taking full advantage of epiphytic lichens as sensitive indicators of climate change and air pollution. This literature reviewis intended to provide a starting point for developing practical biomonitoring tools that elucidate the potential of hair-lichens, associated with high-elevation forests, as ecological indicators of global change in the European Alps. We found support for the practical use of hair-lichens to detect the impact of climate change and nitrogen pollution in high-elevation forest habitats. The use of these organisms as ecological indicators presents an opportunity to expand monitoring activities and develop predictive tools that support decisions on how to mitigate the effects of global change in the Alps

TORRENTIAL RAIN EVENTS OVER THE CÉVENNES-VIVARAIS REGION

High resolution numerical simulations of recent flash-flood events that have occurred over Mediterranean coasts are used to underline the physical mechanisms leading to the stationary of the precipitating systems and the predictability associated with such events. Three cases, including the two last extreme flash-flood events over Southeastern France, have been simulated : the 12-13 November 1999 catastrophe over the Aude region (MAP IOP16), the 8-9 September 2002 flash-flood over the Gard region and the less paroxysmal event of 13-14 October 1995 over the Cévennes-Vivarais relief. Sensitivity to the initial conditions, to the Massif Central relief and to the Sea Surface Temperature (SST) has been studied

Frontogenesis of the Angola–Benguela Frontal Zone

A diagnostic analysis of the climatological annual mean and seasonal cycle of the Angola–Benguela Frontal Zone (ABFZ) is performed by applying an ocean frontogenetic function (OFGF) to the ocean mixing layer (OML). The OFGF reveals that the meridional confluence and vertical tilting terms are the most dominant contributors to the frontogenesis of the ABFZ. The ABFZ shows a well-pronounced semiannual cycle with two maximum (minimum) peaks in April–May and November–December (February–March and July–August). The development of the two maxima of frontogenesis is due to two different physical processes: enhanced tilting from March to April and meridional confluence from September to October. The strong meridional confluence in September to October is closely related to the seasonal southward intrusion of tropical warm water to the ABFZ that seems to be associated with the development of the Angola Dome northwest of the ABFZ. The strong tilting effect from March to April is attributed to the meridional gradient of vertical velocities, whose effect is amplified in this period due to increasing stratification and shallow OML depth. The proposed OFGF can be viewed as a tool to diagnose the performance of coupled general circulation models (CGCMs) that generally fail at realistically simulating the position of the ABFZ, which leading to huge warm biases in the southeastern Atlantic.</p

The Quantity Theory of Money is Valid. The New Keynesians are Wrong!

We test the quantity theory of money (QTM) using a novel approach and a large new sample. We do not follow the usual approach of first differentiating the logarithm of the Cambridge equation to obtain an equation relating the growth rate of real GDP, the growth rate of money and inflation. These variables must then again be ‘integrated’ by averaging in order to obtain stable relationships. Instead we suggest a much simpler procedure for testing directly the stability of the coefficient of the Cambridge equation. For 125 countries and post-war data we find the coefficient to be surprisingly stable. We do not select for high inflation episodes as was done in most empirical studies; inflation rates do not even appear in our data set. Much work supporting the QTM has been done by economic historians and at the University of Chicago by Milton Friedman and his associates. The QTM was a foundation stone of the monetarist revolution. Subsequently belief in it waned. The currently dominant New Keynesian School, implicitly or explicitly denies the validity of the QTM. We survey this history and argue that the QTM is valid and New Keynesians are wrong