Angulin-1 (LSR) Affects Paracellular Water Transport, However Only in Tight Epithelial Cells

Water transport in epithelia occurs transcellularly (aquaporins) and paracellularly (claudin-2, claudin-15). Recently, we showed that downregulated tricellulin, a protein of the tricellular tight junction (tTJ, the site where three epithelial cells meet), increased transepithelial water flux. We now check the hypothesis that another tTJ-associated protein, angulin-1 (alias lipolysis-stimulated lipoprotein receptor, LSR) is a direct negative actuator of tTJ water permeability depending on the tightness of the epithelium. For this, a tight and an intermediate-tight epithelial cell line, MDCK C7 and HT-29/B6, were stably transfected with CRISPR/Cas9 and single-guide RNA targeting angulin-1 and morphologically and functionally characterized. Water flux induced by an osmotic gradient using 4-kDa dextran caused water flux to increase in angulin-1 KO clones in MDCK C7 cells, but not in HT-29/B6 cells. In addition, we found that water permeability in HT-29/B6 cells was not modified after either angulin-1 knockout or tricellulin knockdown, which may be related to the presence of other pathways, which reduce the impact of the tTJ pathway. In conclusion, modulation of the tTJ by knockout or knockdown of tTJ proteins affects ion and macromolecule permeability in tight and intermediate-tight epithelial cell lines, while the transepithelial water permeability was affected only in tight cell lines

The influence of organic versus conventional feeding on the growth and survival of gilthead sea bream Sparus aurata L. juveniles

Sparus aurata specimens of 11 months of age (mean weight: 90.2 g, mean length: 18.3 cm) were classified in two diet groups: one control group was fed with conventional diet, and one experimental group was fed with an organic diet. The body and muscle parameters were studied at 0, 41 and 71 days of the experiment. The results showed the highest values of body length and weight as well as the best biological feed conversion rates in the organic group. The transverse area of white muscle, the hyperplasia and the muscle fibres density were also higher in the organic than in the conventional group (P>0.05). In contrast, hypertrophy was greater in the conventional than in the organic group (P<0.05). Survival was 100% in both groups. In conclusion, the organic feeding regime was more favourable for growth than conventional feeding.Versión del edito

Selective Interactions of Valeriana officinalis Extracts and Valerenic Acid with [3H]Glutamate Binding to Rat Synaptic Membranes

Although GABA neurotransmission has been suggested as a mechanism for Valeriana officinalis effects, CNS depression can also be evoked by inhibition of ionotropic (iGluR) and metabotropic glutamate receptors (mGluR). In this study, we examined if aqueous valerian extract interacted with glutamatergic receptors. Freshly prepared aqueous valerian extract was incubated with rat cortical synaptic membranes in presence of 20 nM [3H]Glutamate. Aqueous valerian extract increased [3H]Glutamate binding from 1 × 10−7 to 1 × 10−3 mg/mL. In the presence of (2S,1′S,2′S)-2-(Carboxycyclopropyl)glycine (LCCG-I) and (2S,2′R,3′R)-2-(2′,3′-Dicarboxycyclopropyl)glycine (DCG-IV), Group II mGluR agents, valerian extract markedly decreased [3H]Glutamate binding, while (2S)-2-amino-3-(3,5-dioxo-1,2,4-oxadiazolidin-2-yl) propanoic acid) (quisqualic acid, QA), Group I mGluR agonist, increased [3H]Glutamate binding. At 0.05 mg/mL aqueous valerian extract specifically interacted with kainic acid NMDA and AMPA receptors. Valerenic acid, a marker compound for Valeriana officinalis, increased the [3H]Glutamate binding after 1.6 × 10−2 mg/mL, and at 0.008 mg/mL it interacted only with QA (Group I mGluR). The selective interactions of valerian extract and valerenic acid with Group I and Group II mGluR may represent an alternative explanation for the anxiolytic properties of this plant

A beam-beam monitoring detector for the MPD experiment at NICA

The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR). Its main goal is to study the phase diagram of the strongly interacting matter produced in heavy-ion collisions. These studies, while providing insight into the physics of heavy-ion collisions, are relevant for improving our understanding of the evolution of the early Universe and the formation of neutron stars. In order to extend the MPD trigger capabilities, we propose to include a high granularity beam-beam monitoring detector (BE-BE) to provide a level-0 trigger signal with an expected time resolution of 30 ps. This new detector will improve the determination of the reaction plane by the MPD experiment, a key measurement for flow studies that provides physics insight into the early stages of the reaction. In this work, we use simulated Au+Au collisions at NICA energies to show the potential of such a detector to determine the event plane resolution, providing further redundancy to the detectors originally considered for this purpose namely, the Fast Forward Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for the time resolution studies of two prototype cells carried out at the T10 beam line at the CERN PS complex.Comment: 16 pages, 12 figures. Updated to published version with added comments and correction

Characterizing the Cool KOIs II. The M Dwarf KOI-254 and its Hot Jupiter

We report the confirmation and characterization of a transiting gas giant planet orbiting the M dwarf KOI-254 every 2.455239 days, which was originally discovered by the Kepler mission. We use radial velocity measurements, adaptive optics imaging and near infrared spectroscopy to confirm the planetary nature of the transit events. KOI-254b is the first hot Jupiter discovered around an M-type dwarf star. We also present a new model-independent method of using broadband photometry to estimate the mass and metallicity of an M dwarf without relying on a direct distance measurement. Included in this methodology is a new photometric metallicity calibration based on J-K colors. We use this technique to measure the physical properties of KOI-254 and its planet. We measure a planet mass of Mp = 0.505 Mjup, radius Rp = 0.96 Rjup and semimajor axis a = 0.03 AU, based on our measured stellar mass Mstar = 0.59 Msun and radius Rstar = 0.55 Rsun. We also find that the host star is metal-rich, which is consistent with the sample of M-type stars known to harbor giant planets.Comment: AJ accepted (in press

Prospecting in ultracool dwarfs : Measuring the metallicities of mid- and late-m dwarfs

© 2014. The American Astronomical Society. All rights reserved.Metallicity is a fundamental parameter that contributes to the physical characteristics of a star. The low temperatures and complex molecules present in M dwarf atmospheres make it difficult to measure their metallicities using techniques that have been commonly used for Sun-like stars. Although there has been significant progress in developing empirical methods to measure M dwarf metallicities over the last few years, these techniques have been developed primarily for early- to mid-M dwarfs. We present a method to measure the metallicity of mid- to late-M dwarfs from moderate resolution (R ∼ 2000) K-band (≃ 2.2 μm) spectra. We calibrate our formula using 44 wide binaries containing an F, G, K, or early-M primary of known metallicity and a mid- to late-M dwarf companion. We show that similar features and techniques used for early-M dwarfs are still effective for late-M dwarfs. Our revised calibration is accurate to ∼0.07 dex for M4.5-M9.5 dwarfs with -0.58 <[Fe/H] <+0.56 and shows no systematic trends with spectral type, metallicity, or the method used to determine the primary star metallicity. We show that our method gives consistent metallicities for the components of M+M wide binaries. We verify that our new formula works for unresolved binaries by combining spectra of single stars. Lastly, we show that our calibration gives consistent metallicities with the Mann et al. study for overlapping (M4-M5) stars, establishing that the two calibrations can be used in combination to determine metallicities across the entire M dwarf sequence.Peer reviewe

Differential contribution of the two major polygalacturonases from Penicillium digitatum to virulence towards citrus fruit

The fungus Penicillium digitatum is the causal agent of the citrus green mould, the major postharvest diseases of citrus fruit. Lesions on the surface of infected fruits first appear as soft areas around the inoculation site, due to maceration of fruit. The macerating activity has been associated with pectinases secreted by the fungus during infection. In order to evaluate the contribution to virulence and macerating activity of the two major polygalacturonases (PGs) secreted by P. digitatum, we have obtained and characterized mutants lacking either pg1 or pg2, the genes encoding PG1 and PG2, respectively. Disease incidence of deletants in either gene was not different from that of the parental strain or ectopic transformants. However, disease progressed more slowly in deletants, especially in those lacking the pg2 gene. The lesions originated by the Δpg2 deletants were not as soft and the pH was not as acid as those originated by either the wild type strain or the ectopic transformants. Total PG activity in the macerated tissue was also lower in fruits infected with the Δpg2 deletants. Interestingly, the macerated tissue of oranges infected with Δpg2 deletants showed around 50% reduction in galacturonic acid content with respect to lesions caused by any other strain.The technical assistance of Ana Izquierdo is gratefully acknowledged. LG-C's research is funded in part by the Spanish Ministry of Economy, Industry and Competitiveness (AGL2011-30519-C03-01 and AGL2014-55802-R) and the Generalitat Valenciana (PROMETEOII/2014/027). ML-P was supported by a “Formación de Personal Investigador” scholarship (BES-2006-12983). Authors want to thank the technical assistance of S. Dashevskaya and the financial support by AGL2011-30519-CO3-03 from the “Ministerio de Economía y Competitividad” (MINECO, Spain), and the CERCA Programme/Generalitat de Catalunya