V39: an unusual object in the field of IC 1613

The variable star V39 in the field of IC 1613 is discussed in the light of the available photometric and new spectroscopic data. It has strong emission Balmer lines, and the observed characteristics could be explained by a W Vir pulsating star with a period of 14.341 d, located at more than 115 kpc, that is in the very outer halo of our Galaxy. It should have an apparent companion, a long period (1118d) red variable, belonging to IC 1613. The main uncertainty in this interpretation is an emission feature at 668.4 nm, which we tentatively identified as a He I line.Comment: 5 pages; accepted for publication in Astronomy & Astrophysic

The Cepheid Phase Lag Revisited

We compute the phase lags between the radial velocity curves and the light curves $\Delta \Phi_1= \phi^{V_r}_1 - \phi^{mag}_1$ for classical Cepheid model sequences both in the linear and the nonlinear regimes. The nonlinear phase lags generally fall below the linear ones except for high period models where they lie above, and of course for low pulsation amplitudes where the two merge. The calculated phase lags show good agreement with the available observational data of normal amplitude Galactic Cepheids. The metallicity has but a moderate effect on the phase lag, while the mass-luminosity relation and the parameters of the turbulent convective model (time-dependent mixing length) mainly influence the modal selection and the period, which is then reflected in the period -- $\Delta \Phi_1$ diagram. We discuss the potential application of this observable as a discriminant for pulsation modes and as a test for ultra-low amplitudes (ULA) pulsation.Comment: 11 pages, 8 figures, accepted for publication in ApJ, minor revisions in the text and figures, (black and white version available from 2nd author's website

A large-N approximated field theory for multipartite entanglement

We study the characterization of multipartite entanglement for the random states of an $n$-qbit system. Unable to solve the problem exactly we generalize it, changing complex numbers into real vectors with $N_c$ components (the original problem is recovered for $N_c=2$). Studying the leading diagrams in the large-$N_c$ approximation, we unearth the presence of a phase transition and, in an explicit example, show that the so-called entanglement frustration disappears in the large-$N_c$ limit.Comment: 12 pages, 15 figure

Hydrodynamical Survey of First Overtone Cepheids

A hydrodynamical survey of the pulsational properties of first overtone Galactic Cepheids is presented. The goal of this study is to reproduce their observed light- and radial velocity curves. The comparison between the models and the observations is made in a quantitative manner on the level of the Fourier coefficients. Purely radiative models fail to reproduce the observed features, but convective models give good agreement. It is found that the sharp features in the Fourier coefficients are indeed caused by the P1/P4 = 2 resonance, despite the very large damping of the 4th overtone. For the adopted mass-luminosity relation the resonance center lies near a period of 4.2d +/- 0.2 as indicated by the observed radial velocity data, rather than near 3.2d as the light-curves suggest.Comment: ApJ, 12 pages, (slightly) revise

The Index Distribution of Gaussian Random Matrices

We compute analytically, for large N, the probability distribution of the number of positive eigenvalues (the index N_{+}) of a random NxN matrix belonging to Gaussian orthogonal (\beta=1), unitary (\beta=2) or symplectic (\beta=4) ensembles. The distribution of the fraction of positive eigenvalues c=N_{+}/N scales, for large N, as Prob(c,N)\simeq\exp[-\beta N^2 \Phi(c)] where the rate function \Phi(c), symmetric around c=1/2 and universal (independent of $\beta$), is calculated exactly. The distribution has non-Gaussian tails, but even near its peak at c=1/2 it is not strictly Gaussian due to an unusual logarithmic singularity in the rate function.Comment: 4 pages Revtex, 4 .eps figures include

The Araucaria Project. Bright Variable Stars in NGC 6822 from a Wide-Field Imaging Survey

We have performed a search for variable stars in the dwarf irregular galaxy NGC 6822 using wide-field multi-epoch VI photometry down to a limiting magnitude $V$ $\sim$ 22. Apart from the Cepheid variables in this galaxy already reported in an earlier paper by Pietrzynski et al. (2004), we have found 1019 "non-periodic" variable stars, 50 periodically variable stars with periods ranging from 0.12 to 66 days and 146 probably periodic variables. Twelve of these stars are eclipsing binaries and fifteen are likely new, low-amplitude Cepheids. Interestingly, seven of these Cepheid candidates have periods longer than 100 days, have very low amplitudes (less than 0.2 mag in $I$), and are very red. They could be young, massive Cepheids still embedded in dusty envelopes. The other objects span a huge range in colours and represent a mixture of different types of luminous variables. Many of the variables classified as non-periodic in the present study may turn out to be {\it periodic} variables once a much longer time baseline will be available to study them. We provide the catalogue of photometric parameters and show the atlas of light curves for the new variable stars. Our present catalogue is complementary to the one of Baldacci et al. (2005) which has focussed on very short-period and fainter variables in a subfield in NGC 6822.Comment: Accepted for publication in A&

A nutrition mathematical model to account for dietary supply and requirements of energy and nutrients for domesticated small ruminants: the development and evaluation of the Small Ruminant Nutrition System

A mechanistic model that predicts nutrient requirements and biological values of feeds for sheep (Cornell Net Carbohydrate and Protein System; CNCPS-S) was expanded to include goats and the name was changed to the Small Ruminant Nutrition System (SRNS). The SRNS uses animal and environmental factors to predict metabolizable energy (ME) and protein, and Ca and P requirements. Requirements for goats in the SRNS are predicted based on the equations developed for CNCPS-S, modified to account for specific requirements of goats, including maintenance, lactation, and pregnancy requirements, and body reserves. Feed biological values are predicted based on carbohydrate and protein fractions and their ruminal fermentation rates, forage, concentrate and liquid passage rates, and microbial growth. The evaluation of the SRNS for sheep using published papers (19 treatment means) indicated no mean bias (MB; 1.1 g/100 g) and low root mean square prediction error (RMSPE; 3.6 g/100g) when predicting dietary organic matter digestibility for diets not deficient in ruminal nitrogen. The SRNS accurately predicted gains and losses of shrunk body weight (SBW) of adult sheep (15 treatment means; MB = 5.8 g/d and RMSPE = 30 g/d) when diets were not deficient in ruminal nitrogen. The SRNS for sheep had MB varying from -34 to 1 g/d and RSME varying from 37 to 56 g/d when predicting average daily gain (ADG) of growing lambs (42 treatment means). The evaluation of the SRNS for goats based on literature data showed accurate predictions for ADG of kids (31 treatment means; RMSEP = 32.5 g/d; r2= 0.85; concordance correlation coefficient, CCC, = 0.91), daily ME intake (21 treatment means; RMSEP = 0.24 Mcal/d g/d; r2 = 0.99; CCC = 0.99), and energy balance (21 treatment means; RMSEP = 0.20 Mcal/d g/d; r2 = 0.87; CCC = 0.90) of goats. In conclusion, the SRNS for sheep can accurately predict dietary organic matter digestibility, ADG of growing lambs and changes in SBW of mature sheep. The SRNS for goats is suitable for predicting ME intake and the energy balance of lactating and non-lactating adult goats and the ADG of kids of dairy, meat, and indigenous breeds. The SRNS model is available at http://nutritionmodels.tamu.edu

Low Input Techniques for Firebreak Covering: Agronomic Aspects

In Sardinia, wild fire prevention is traditionally passive , based on mechanical removal of vegetation and upper soil layers. This has a dramatic negative effect on plant diversity and soil erosion. This experiment concerns active prevention of wildfires, based on green covering and grazing of firebreaks. The objective was the establishment of a persistent green cover, to be grazed by animals to reduce fuel accumulation

Affective Temperaments and Somatization Among Unipolar Depression Patients and Healthy Controls

Introduction Literature describes important comorbidity rates between somatization and mood disorders. Furthermore, there are data suggesting an association between affective temperament and somatization traits in healthy subjects. Objective In the present observational study, we investigated affective temperaments and somatization aspects in clinical and healthy samples. Aim The study focused on differences between unipolar depressive inpatients (DEP) and controls (C). Method We administered to 20 DEP and 20 C following questionnaires: Mini International Neuropsychiatric Interview (MINI), 17-item Self Rating Depression Scale (SDS), Hypomania check list 32(HCL-32), Self Rating Anxiety Scale (SAS), DCPR diagnostic criteria for psychosomatic research, Brief TEMPS-A, Modified Somatic Perception Questionnaire (MSPQ), Somatosensory Amplification Scale-SSAS. DEP and C were matched for age, sex and marital status. Result About temperaments, ANOVA showed that DEP were more cyclothymic (p Conclusion Our data suggest that DEP present an important affective temperamental dysregulation. Relative to somatization aspects, DEP show a greater vulnerability than C