495 research outputs found

    Developmental expression of esophageal gland antigens and their detection in stylet secretions of Meloidogyne incognita

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    La microscopie en immunofluorescence a Ă©tĂ© utilisĂ©e avec des anticorps monoclonaux pour montrer que la production d'antigĂšnes dans les glandes oesophagiennes de #Meloidogyne incognita est rĂ©gulĂ©e par le dĂ©veloppement durant la phase parasite et que quelques-uns de ces antigĂšnes peuvent ĂȘtre excrĂ©tĂ©s au travers du stylet. Plusieurs antigĂšnes des glandes oesophagiennes sont temporairement exprimĂ©s dans les glandes subventrales et dorsale des juvĂ©niles prĂ©parasites de deuxiĂšme stade (J2), des juvĂ©niles parasites (J2) et des femelles adultes. Deux anticorps monoclonaux reconnaissant les glandes subventrales de J2 et un anticorps monoclonal reconnaissant la glande dorsale et les glandes subventrales de J2, reconnaissent Ă©galement les sĂ©crĂ©tions passant au travers du stylet des J2. Deux anticorps monoclonaux reconnaissant la glande dorsale des femelles adultes, et un anticorps monoclonal reconnaissant leurs glandes subventrales, reconnaissent aussi les sĂ©crĂ©tions passant au travers du stylet des femelles adultes. Ces rĂ©sultats montrent que les sĂ©crĂ©tions des glandes dorsale et subventrales peuvent passer au travers du stylet de #M. incognita et que leur expression est rĂ©gulĂ©e par le dĂ©veloppement. (RĂ©sumĂ© d'auteur

    Larval cloning in the crown-of-thorns sea star, a keystone coral predator

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    The crown-of-thorns starfish (COTS), Acanthaster cf. solaris, is an iconic keystone predator whose population outbreaks have devastating consequences for Indo-Pacific coral reefs. We tested the effects of algal food supply and larval density on the frequency of larval cloning by culturing the early bipinnaria larvae of COTS under variable conditions. Here we show that larval COTS are able to clone themselves in both low and high food conditions, and that the frequency of larval cloning increases with levels of food, but is unaffected by larval density. Across all density treatments (0.3, 1.0 and 3.0 larvae ml-1), the per-capita rate of cloning increased from 4.3% in low, oligotrophic conditions (0.17 ”g chl a l-1) to 7.9% in high food conditions (1.7 ”g chl a l-1). Larval cloning has the potential to increase both COTS larval supply and the dispersal distance of planktonic larval stages, both of which are critical factors in predicting the timing and location of outbreaks of this species. In addition, the relationship between algal food supply and larval cloning frequency lends support to bottom-up hypotheses (e.g. nutrient enrichment) as predictors of COTS outbreaks. However, cloning was observed even under the oligotrophic conditions characteristic of coral reefs

    `Hath charms to soothe . . .': An exploratory study of how high-functioning adults with ASD experience music

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    Semi-structured interviews were conducted with 12 highfunctioning adults on the autism spectrum, in order to examine the nature of their personal experiences of music. Consistent with the literature on typically developing people’s engagement with music, the analysis showed that most participants exploit music for a wide range of purposes in the cognitive, emotional and social domains, including mood management, personal development and social inclusion. However, in contrast to typically developing people, the ASD group’s descriptions of mood states reflected a greater reliance on internally focused (arousal) rather than externally focused (emotive) language

    Mass generation for abelian spin-1 particles via a symmetric tensor

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    In the topologically massive BF model (TMBF) the photon becomes massive via coupling to an antisymmetric tensor, without breaking the U(1) gauge symmetry . There is no need of a Higgs field. The TMBF model is dual to a first-order (in derivatives) formulation of the Maxwell-Proca theory where the antisymmetric field plays the role of an auxiliary field. Since the Maxwell-Proca theory also admits a first-order version which makes use of an auxiliary symmetric tensor, we investigate here a possible generalization of the TMBF model where the photon acquires mass via coupling to a symmetric tensor. We show that it is indeed possible to build up dual models to the Maxwell-Proca theory where the U(1) gauge symmetry is manifest without Higgs field, but after a local field redefinition the vector field eats up the trace of the symmetric tensor and becomes massive. So the explicit U(1) symmetry can be removed unlike the TMBF model.Comment: 15 pages, no figures, one reference added, two typos on page 3 fixe

    Observational Constraints on Chaplygin Quartessence: Background Results

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    We derive the constraints set by several experiments on the quartessence Chaplygin model (QCM). In this scenario, a single fluid component drives the Universe from a nonrelativistic matter-dominated phase to an accelerated expansion phase behaving, first, like dark matter and in a more recent epoch like dark energy. We consider current data from SNIa experiments, statistics of gravitational lensing, FR IIb radio galaxies, and x-ray gas mass fraction in galaxy clusters. We investigate the constraints from this data set on flat Chaplygin quartessence cosmologies. The observables considered here are dependent essentially on the background geometry, and not on the specific form of the QCM fluctuations. We obtain the confidence region on the two parameters of the model from a combined analysis of all the above tests. We find that the best-fit occurs close to the Λ\LambdaCDM limit (α=0\alpha=0). The standard Chaplygin quartessence (α=1\alpha=1) is also allowed by the data, but only at the ∌2σ\sim2\sigma level.Comment: Replaced to match the published version, references update

    On the accretion disc properties in eclipsing dwarf nova EM Cyg

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    In this paper we analyzed the behavior of the unusual dwarf nova EM Cyg using the data obtained in April-October, 2007 in Vyhorlat observatory (Slovak Republic) and in September, 2006 in Crimean Astrophysical Observatory (Ukraine). During our observations EM Cyg has shown outbursts in every 15-40 days. Because on the light curves of EM Cyg the partial eclipse of an accretion disc is observed we applied the eclipse mapping technique to reconstruct the temperature distribution in eclipsed parts of the disc. Calculations of the accretion rate in the system were made for the quiescent and the outburst states of activity for different distances.Comment: 6 pages, 3 figures, accepted in Astrophysics and Space Scienc
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