Exploring the long-term variability and evolutionary stage of the interacting binary DQ Velorum

To progress in the comprehension of the double periodic variable (DPV) phenomenon, we analyse a series of optical spectra of the DPV system DQ Velorum during much of its long-term cycle. In addition, we investigate the evolutionary history of DQ Vel using theoretical evolutionary models to obtain the best representation for the current observed stellar and orbital parameters of the binary. We investigate the evolution of DQ Vel through theoretical evolutionary models to estimate the age and the mass transfer rate which are compared with those of its twin V393 Scorpii. Donor subtracted spectra covering around 60% of the long-term cycle, allow us to investigate time-modulated spectral variations of the gainer star plus the disc. We compare the observed stellar parameters of the system with a grid of theoretical evolutionary tracks computed under a conservative and a non-conservative evolution regime. We have found that the EW of Balmer and helium lines in the donor subtracted spectra are modulated with the long-term cycle. We observe a strenghtening in the EWs in all analysed spectral features at the minimum of the long-term cycle which might be related to an extra line emission during the maximum of the long-term variability. Difference spectra obtained at the secondary eclipse support this scenario. We have found that a non-conservative evolutionary model is a better representation for the current observed properties of the system. The best evolutionary model suggests that DQ Vel has an age of 7.40 x 10^{7} yr and is currently in a low mass transfer rate (-9.8x10^{-9} Msun/yr) stage, after a mass transfer burst episode. Comparing the evolutionary stages of DQ Vel and V393 Sco we observed that the former is an older system with a lower mass transfer rate. This might explain the differences observed in the physical parameters of their accretion discs.Comment: 10 pages, 13 figure

Climate change and its effect on agriculture, water resources and human health sectors in Poland

Multi-model ensemble climate projections in the ENSEMBLES Project of the EU allowed the authors to quantify selected extreme-weather indices for Poland, of importance to climate impacts on systems and sectors. Among indices were: number of days in a year with high value of the heat index; with high maximum and minimum temperatures; length of vegetation period; and number of consecutive dry days. Agricultural, hydrological, and human health indices were applied to evaluate the changing risk of weather extremes in Poland in three sectors. To achieve this, model-based simulations were compared for two time horizons, a century apart, i.e., 1961–1990 and 2061–2090. Climate changes, and in particular increases in temperature and changes in rainfall, have strong impacts on agriculture via weather extremes – droughts and heat waves. The crop yield depends particularly on water availability in the plant development phase. To estimate the changes in present and future yield of two crops important for Polish agriculture i.e., potatoes and wheat, some simple empirical models were used. For these crops, decrease of yield is projected for most of the country, with national means of yield change being: –2.175 t/ha for potatoes and –0.539 t/ha for wheat. Already now, in most of Poland, evapotranspiration exceeds precipitation during summer, hence the water storage (in surface water bodies, soil and ground) decreases. Summer precipitation deficit is projected to increase considerably in the future. The additional water supplies (above precipitation) needed to use the agro-potential of the environment would increase by half. Analysis of water balance components (now and in the projected future) can corroborate such conclusions. As regards climate and health, a composite index, proposed in this paper, is a product of the number of senior discomfort days and the number of seniors (aged 65+). The value of this index is projected to increase over 8-fold during 100 years. This is an effect of both increase in the number of seniors (over twofold) and the number of senior-discomfort days (nearly fourfold)

A study of the interacting binary V 393 Scorpii

We present high resolution J-band spectroscopy of V 393 Sco obtained with the CRIRES at the ESO Paranal Observatory along with a discussion of archival IUE spectra and published broad band magnitudes. The best fit to the spectral energy distribution outside eclipse gives $T_{1}$= 19000 $\pm$ 500 $K$ for the gainer, $T_{2}$= 7250 $\pm$ 300 $K$ for the donor, $E(B-V)$= 0.13 $\pm$ 0.02 mag. and a distance of $d$= 523 $\pm$ 60 pc, although circumstellar material was not considered in the fit. We argue that V 393 Sco is not a member of the open cluster M7. The shape of the He I 1083 nm line shows orbital modulations that can be interpreted in terms of an optically thick pseudo-photosphere mimicking a hot B-type star and relatively large equatorial mass loss through the Lagrangian L3 point during long cycle minimum. IUE spectra show several (usually asymmetric) absorption lines from highly ionized metals and a narrow L$\alpha$ emission core on a broad absorption profile. The overall behavior of these lines suggests the existence of a wind at intermediate latitudes. From the analysis of the radial velocities we find $M_{2}/M_{1}$= 0.24 $\pm$ 0.02 and a mass function of $f$= 4.76 $\pm$ 0.24 M$\odot$. Our observations favor equatorial mass loss rather than high latitude outflows as the cause for the long variability.Comment: 13 pages, 14 figures, 7 tables. Accepted for publication in MNRAS, main journa

Novel and promising compounds to treat Cryptosporidium parvum infections

No fully effective approved drug therapy exists for Cryptosporidium infections of immunocompetent and immunocompromised patients. Here, we investigated 11 benzimidazole derivatives carrying substituted thioalkyl and thiobenzyl groups at position 2 of benzimidazole nucleus and additional substituents at the benzene part of benzimidazole for inhibition of the in vitro growth of the intestinal protozoan parasite, Cryptosporidium parvum. Three of them, i.e., 5-carboxy-2-(4-nitrobenzylthio)-1H-benzimidazole, 5,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, and 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, (compounds 5, 7, and 8) were the most active (IC50 28–31 μM). The concentration of compounds 5, 7, and 8 that caused 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was comparable with those obtained for paromomycin

Novel and promising compounds to treat Cryptosporidium parvum infections

No fully effective approved drug therapy exists for Cryptosporidium infections of immunocompetent and immunocompromised patients. Here, we investigated 11 benzimidazole derivatives carrying substituted thioalkyl and thiobenzyl groups at position 2 of benzimidazole nucleus and additional substituents at the benzene part of benzimidazole for inhibition of the in vitro growth of the intestinal protozoan parasite, Cryptosporidium parvum. Three of them, i.e., 5-carboxy-2-(4-nitrobenzylthio)-1H-benzimidazole, 5,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, and 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, (compounds 5, 7, and 8) were the most active (IC50 28–31 μM). The concentration of compounds 5, 7, and 8 that caused 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was comparable with those obtained for paromomycin

Bifurcations in the Space of Exponential Maps

This article investigates the parameter space of the exponential family $z\mapsto \exp(z)+\kappa$. We prove that the boundary (in \C) of every hyperbolic component is a Jordan arc, as conjectured by Eremenko and Lyubich as well as Baker and Rippon. In fact, we prove the stronger statement that the exponential bifurcation locus is connected in \C, which is an analog of Douady and Hubbard's celebrated theorem that the Mandelbrot set is connected. We show furthermore that $\infty$ is not accessible through any nonhyperbolic ("queer") stable component. The main part of the argument consists of demonstrating a general "Squeezing Lemma", which controls the structure of parameter space near infinity. We also prove a second conjecture of Eremenko and Lyubich concerning bifurcation trees of hyperbolic components.Comment: 29 pages, 3 figures. The main change in the new version is the introduction of Theorem 1.1 on the connectivity of the bifurcation locus, which follows from the results of the original version but was not explicitly stated. Also, some small revisions have been made and references update

OSMOSE an Experimental Program for Improving Neutronic Predictions of Advanced Nuclear Fuels.

This report describes the technical results of tasks and activities conducted in FY07 to support the DOE-CEA collaboration on the OSMOSE program. The activities are divided into five high-level tasks: reactor modeling and pre-experiment analysis, sample fabrication and analysis, reactor experiments, data treatment and analysis, and assessment for relevance to high priority advanced reactor programs (such as GNEP and Gen-IV)

The impact of Gaia and LSST on binary stars and exo-planets

Two upcoming large scale surveys, the ESA Gaia and LSST projects, will bring a new era in astronomy. The number of binary systems that will be observed and detected by these projects is enormous, estimations range from millions for Gaia to several tens of millions for LSST. We review some tools that should be developed and also what can be gained from these missions on the subject of binaries and exoplanets from the astrometry, photometry, radial velocity and their alert systems.Comment: 8 pages, 2 figures, Proceedings of the IAU Symposium No. 282: From Interacting Binaries to Exoplanets: Essential Modeling Tools. Tatranska Lomnica, Slovaki

Molecular characterisation of protist parasites in human-habituated mountain gorillas (Gorilla beringei beringei), humans and livestock, from Bwindi impenetrable National Park, Uganda

Over 60 % of human emerging infectious diseases are zoonotic, and there is growing evidence of the zooanthroponotic transmission of diseases from humans to livestock and wildlife species, with major implications for public health, economics, and conservation. Zooanthroponoses are of relevance to critically endangered species; amongst these is the mountain gorilla (Gorilla beringei beringei) of Uganda. Here, we assess the occurrence of Cryptosporidium, Cyclospora, Giardia, and Entamoeba infecting mountain gorillas in the Bwindi Impenetrable National Park (BINP), Uganda, using molecular methods. We also assess the occurrence of these parasites in humans and livestock species living in overlapping/adjacent geographical regions