Comparison of Raspberry bushy dwarf virus isolates from Hungary and Slovenia

In 2006 and 2007 samples of grapevine and Rubus species were collected and analysed by DAS-ELISA to survey the presence of Raspberry bushy dwarf virus (RBDV) in Slovenia and Hungary. Seven varieties of raspberry from one Hungarian collection orchard were found to be infected. In Slovenia the presence of RBDV was confirmed only in three samples of wild Rubus. None of the 133 samples from different locations in Hungary proved to be infected with RBDV, although this virus is found to be widely distributed in grapevine in neighbouring Slovenia. Serological characterisation with three monoclonal antibodies (R2, R5 and D1) was performed on positive samples. Selected positive samples were partially sequenced. The results of serological and molecular analyses were compared with the analyses of raspberry and grapevine isolates obtained in Slovenia from other projects and published RBDV sequences from the GeneBank database to study the variability among hosts and locations. Isolates from grapevine grouped separately from the black raspberry isolate and all the red raspberry isolates. RBDV isolates from Hungarian samples formed a subgroup within red and black raspberry group.Keywords: RBDV, variability, Rubus, raspberry, grapevine, sequences, monoclonal antibodie

Antagonism between Bacteriostatic and Bactericidal Antibiotics Is Prevalent

Combination therapy is rarely used to counter the evolution of resistance in bacterial infections. Expansion of the use of combination therapy requires knowledge of how drugs interact at inhibitory concentrations. More than 50 years ago, it was noted that, if bactericidal drugs are most potent with actively dividing cells, then the inhibition of growth induced by a bacteriostatic drug should result in an overall reduction of efficacy when the drug is used in combination with a bactericidal drug. Our goal here was to investigate this hypothesis systematically. We first constructed time-kill curves using five different antibiotics at clinically relevant concentrations, and we observed antagonism between bactericidal and bacteriostatic drugs. We extended our investigation by performing a screen of pairwise combinations of 21 different antibiotics at subinhibitory concentrations, and we found that strong antagonistic interactions were enriched significantly among combinations of bacteriostatic and bactericidal drugs. Finally, since our hypothesis relies on phenotypic effects produced by different drug classes, we recreated these experiments in a microfluidic device and performed time-lapse microscopy to directly observe and quantify the growth and division of individual cells with controlled antibiotic concentrations. While our single-cell observations supported the antagonism between bacteriostatic and bactericidal drugs, they revealed an unexpected variety of cellular responses to antagonistic drug combinations, suggesting that multiple mechanisms underlie the interactions

HAT-P-56b: An inflated massive Hot Jupiter transiting a bright F star followed up with K2 Campaign 0 observations

We report the discovery of HAT-P-56b by the HATNet survey, an inflated hot Jupiter transiting a bright F type star in Field 0 of NASA's K2 mission. We combine ground-based discovery and follow-up light curves with high precision photometry from K2, as well as ground-based radial velocities from TRES on the FLWO 1.5m telescope to determine the physical properties of this system. HAT-P-56b has a mass of $2.18 M_J$, radius of $1.47 R_J$, and transits its host star on a near-grazing orbit with a period of 2.7908 d. The radius of HAT-P-56b is among the largest known for a planet with $M_p > 2 M_J$. The host star has a V-band magnitude of 10.9, mass of 1.30 $M_\odot$, and radius of 1.43 $R_\odot$. The periodogram of the K2 light curve suggests the star is a $\gamma$ Dor variable. HAT-P-56b is an example of a ground-based discovery of a transiting planet, where space-based observations greatly improve the confidence in the confirmation of its planetary nature, and also improve the accuracy of the planetary parameters.Comment: 13 pages, 11 figures, accepted by A

Neuroendocrine and neurotrophic signaling in Huntington\u27s disease: Implications for pathogenic mechanisms and treatment strategies

Huntington\u27s disease (HD) is a fatal neurodegenerative disease caused by an extended polyglutamine tract in the huntingtin protein. Circadian, sleep and hypothalamic-pituitary-adrenal (HPA) axis disturbances are observed in HD as early as 15 years before clinical disease onset. Disturbances in these key processes result in increased cortisol and altered melatonin release which may negatively impact on brain-derived neurotrophic factor (BDNF) expression and contribute to documented neuropathological and clinical disease features. This review describes the normal interactions between neurotrophic factors, the HPA-axis and circadian rhythm, as indicated by levels of BDNF, cortisol and melatonin, and the alterations in these intricately balanced networks in HD. We also discuss the implications of these alterations on the neurobiology of HD and the potential to result in hypothalamic, circadian, and sleep pathologies. Measurable alterations in these pathways provide targets that, if treated early, may reduce degeneration of brain structures. We therefore focus here on the means by which multidisciplinary therapy could be utilised as a non-pharmaceutical approach to restore the balance of these pathways