Absolute properties of the binary system BB Pegasi

We present a ground based photometry of the low-temperature contact binary BB Peg. We collected all times of mid-eclipses available in literature and combined them with those obtained in this study. Analyses of the data indicate a period increase of 3.0(1) x 10^{-8} days/yr. This period increase of BB Peg can be interpreted in terms of the mass transfer 2.4 x 10^{-8} Ms yr^{-1} from the less massive to the more massive component. The physical parameters have been determined as Mc = 1.42 Ms, Mh = 0.53 Ms, Rc = 1.29 Rs, Rh = 0.83 Rs, Lc = 1.86 Ls, and Lh = 0.94 Ls through simultaneous solution of light and of the radial velocity curves. The orbital parameters of the third body, that orbits the contact system in an eccentric orbit, were obtained from the period variation analysis. The system is compared to the similar binaries in the Hertzsprung-Russell and Mass-Radius diagram.Comment: 17 pages, 3 figures, accepted for Astronomical Journa

Quercirhiza tomentellocumulata” + Quercus suber L.

Mycorrhizae blackish, rough, with soil particles sticking to the mantle. Emanating hyphae dark brown, distributed unevenly. Mantle in outer and middle layers pseudoparenchymatous, with roundish cells. Inner layers with undifferentiated hyphae distributed with no discernible pattern alternating with ring-like arranged regions. Outer mantle layers with roundish cells overlaying groups of 2-6 cells. Emanating hyphae densely warty.Peer reviewe

"Quercirhiza flavocystidiata" + Quercus suber L.

This ectomycorrhiza shows, a cover of bright yellow cystidia (appering fluorescent in surface light), causing a short-spiny surface, on a dark brown mantle. Mantle plectenchy-matous in all layers, outer and middle layers star-like, inner layers plectenchymatous with sinous hyphae. Cystidia similar to normal hyphae, but fusiform and clamped at the base. Rhizomorphs frequent, slightly differentiated, occurring on mycorrhizal systems and in the soil, brown to dark brown, ramified at restricted points, conical-young side branches present cystidia on rhizomorphs lacking. Slerotia lacking.This study was financially supported by Fundaçao Para a Ciência e a Tecnologia (SFRH7 BPD/5560/2001) and HP BIODIBERIA program at the Real Jardín Botánico (Madrid).Peer reviewe

Granulocyte CEACAM3 Is a Phagocytic Receptor of the Innate Immune System that Mediates Recognition and Elimination of Human-specific Pathogens

Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are used by several human pathogens to anchor themselves to or invade host cells. Interestingly, human granulocytes express a specific isoform, CEACAM3, that participates together with CEACAM1 and CEACAM6 in the recognition of CEACAM-binding microorganisms. Here we show that CEACAM3 can direct efficient, opsonin-independent phagocytosis of CEACAM-binding Neisseria, Moraxella, and Haemophilus species. CEACAM3- but not CEACAM6-mediated uptake is blocked by dominant-negative versions of the small GTPase Rac. Moreover, CEACAM3 engagement triggers membrane recruitment and increased GTP loading of Rac that are not observed upon bacterial binding to CEACAM6. Internalization and Rac stimulation are also inhibited by compromising the integrity of an immunoreceptor tyrosine-based activation motif (ITAM)–like sequence in the cytoplasmic tail of CEACAM3 or by interference with Src family protein tyrosine kinases that phosphorylate CEACAM3. In contrast to interfering with CEACAM6, blockage of CEACAM3-mediated events reduces the ability of primary human granulocytes to internalize and eliminate CEACAM-binding bacteria, indicating an important role of CEACAM3 in the control of human-specific pathogens by the innate immune system

Quercirhiza quadratum: a revision of the characters and identity of the ad type ectomycorrhiza

The well-known AD type, described first by Giraud in 1988, is considered as a competitor in black truffle (Tuber melanosporum Vittad.) plantations. It has been mainly observed in T. melanosporum and T. magnatum Pico plantations in France and Italy. This ectomycorrhiza has always been observed on roots of oak (Quercus ilex L. and Q. faginea Lam.) and hazelnut (Corylus avellana L.) plantations with “burnt” areas around the trees, even in those that do not produce black truffle sporocarps, so it can create false expectations in young plantations. The AD type has also been described in nurseries, as a competitive ectomycorrhiza on seedlings inoculated with black truffle. In Spain, AD type has been detected in black truffle plantations and natural holm oak stands in Navarra, Soria, Huesca, Zaragoza, Teruel, Castellón and Valencia. In 2005, De Román & De Miguel, suggested that AD type could be a telephoroid type due to its anatomical and morphological characters. In 2006, Baciarelli-Falini et al. using molecular techniques identified this type as an Ascomycotina belonging to Pezizales. The detailed anatomical, morphological and molecular study of the AD type led to a description as Quercirhiza quadratum (Águeda et al. 2008). Based on the anatomical and morphological characters, the AD type belongs to the Ascomycotina. The presence of Woronin bodies on hyphal septa, and the sometimes slightly dissolved septa, are two typical characters of this group. The DNA sequences obtained from the AD types studied showed close similarities with members of Pyronemataceae and Sarcosomataceae (Pezizales). Both taxonomic groups correspond to the same AD type as found by Baciarelli Falini et al., (2006). One of the studied sequences showed a close identity (100% maximum identity, 84% coverage) with Trichophaea woolhopeia (Cooke & W. Phillips) Arnould, although records of this fungal species are scarce in the Iberian Peninsula

Absolute properties of the spotted eclipsing binary star CV Bootis

We present new V-band differential brightness measurements as well as new radial-velocity measurements of the detached, circular, 0.84-day period, double-lined eclipsing binary system CV Boo. These data along with other observations from the literature are combined to derive improved absolute dimensions of the stars for the purpose of testing various aspects of theoretical modeling. Despite complications from intrinsic variability we detect in the system, and despite the rapid rotation of the components, we are able to determine the absolute masses and radii to better than 1.3% and 2%, respectively. We obtain M(A) = 1.032 +/- 0.013 M(Sun) and R(B) = 1.262 +/- 0.023 R(Sun) for the hotter, larger, and more massive primary (star A), and M(B) = 0.968 +/- 0.012 M(Sun) and R(B) = 1.173 +/- 0.023 R(Sun) for the secondary. The estimated effective temperatures are 5760 +/- 150 K and 5670 +/- 150 K. The intrinsic variability with a period about 1% shorter than the orbital period is interpreted as being due to modulation by spots on one or both components. This implies that the spotted star(s) must be rotating faster than the synchronous rate, which disagrees with predictions from current tidal evolution models according to which both stars should be synchronized. We also find that the radius of the secondary is larger than expected from stellar evolution calculations by about 10%, a discrepancy also seen in other (mostly lower-mass and active) eclipsing binaries. We estimate the age of the system to be approximately 9 Gyr. Both components are near the end of their main-sequence phase, and the primary may have started the shell hydrogen-burning stage.Comment: 17 pages in emulateapj format, including figures and tables. To appear in The Astronomical Journa

Radial Velocity Studies of Close Binary Stars. IX

Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for the eighth set of ten close binary systems: AB And, V402 Aur, V445 Cep, V2082 Cyg, BX Dra, V918 Her, V502 Oph, V1363 Ori, KP Peg, V335 Peg. Half of the systems (V445 Cep, V2082 Cyg, V918 Her, V1363 Ori, V335 Peg) were discovered photometrically by the Hipparcos mission and all systems are double-lined (SB2) contact binaries. The broadening function method permitted improvement of the orbital elements for AB And and V502 Oph. The other systems have been observed for radial velocity variations for the first time; in this group are five bright (V<7.5) binaries: V445 Cep, V2082 Cyg, V918 Her, KP Peg and V335 Peg. Several of the studied systems are prime candidates for combined light and radial-velocity synthesis solutions.Comment: 17+ pages, 2 tables, 4 figure

Soil microclimate changes affect soil fungal communities in a Mediterranean pine forest

Soil microclimate is a potentially important regulator of the composition of plant‐associated fungal communities in climates with significant drought periods. Here, we investigated the spatio‐temporal dynamics of soil fungal communities in a Mediterranean Pinus pinaster forest in relation to soil moisture and temperature. Fungal communities in 336 soil samples collected monthly over 1 year from 28 long‐term experimental plots were assessed by PacBio sequencing of ITS2 amplicons. Total fungal biomass was estimated by analysing ergosterol. Community changes were analysed in the context of functional traits. Soil fungal biomass was lowest during summer and late winter and highest during autumn, concurrent with a greater relative abundance of mycorrhizal species. Intra‐annual spatio‐temporal changes in community composition correlated significantly with soil moisture and temperature. Mycorrhizal fungi were less affected by summer drought than free‐living fungi. In particular, mycorrhizal species of the short‐distance exploration type increased in relative abundance under dry conditions, whereas species of the long‐distance exploration type were more abundant under wetter conditions. Our observations demonstrate a potential for compositional and functional shifts in fungal communities in response to changing climatic conditions. Free‐living fungi and mycorrhizal species with extensive mycelia may be negatively affected by increasing drought periods in Mediterranean forest ecosystems.info:eu-repo/semantics/acceptedVersio