23 research outputs found
A new Aculodes species (Prostigmata: Eriophyoidea: Eriophyidae) associated with medusahead, Taeniatherum caput-medusae (L.) Nevski (Poaceae)
A new species of plant mite (Acari: Eriophyidae) was discovered on medusahead (Taeniatherum caputmedusae), an annual grass that is native to central Asia and the Mediterranean Basin. It is invasive in western North America. Aculodes altamurgiensis sp. nov., is described here and differentiated from other Aculodes spp., on the basis of morphology. Its DNA fingerprinting was reported and compared with Aculodes mckenziei collected from Elymus repens and Bromus inermis. Pairwise comparison of MT-001 sequences between A. altamurgiensis sp. nov., and A. mckenziei revealed 20.2-21.5% genetic divergence between these congeneric species. First collected in Parco Nazionale dell'Alta Murgia in Apulia, Italy in 2014,A. altamurgiensis sp. nov., has been subsequently collected from medusahead in Serbia, Bulgaria, Iran and Turkey. Based on these data and on preliminary observations on the effects of the mite on plant growth, A. altamurgiensis sp. nov., is currently being investigated as a candidate biological control agent of medusahead
Eriophyid mites as biological control agents of two invasive alien plants in Europe : Ailanthus altissima and Ambrosia artemisiifolia
Invasive alien plant species may have a strong impact on indigenous biodiversity and
this is the case of Ailanthus altissima and Ambrosia artemisiifolia, whose control in
the Euro-Mediterranean areas is required.peer-reviewe
Probing the Structure and Evolution of BASS AGN through Eddington Ratios
We constrain the intrinsic Eddington ratio (\lamEdd ) distribution function
for local AGN in bins of low and high obscuration (log NH <= 22 and 22 < log NH
< 25), using the Swift-BAT 70-month/BASS DR2 survey. We interpret the fraction
of obscured AGN in terms of circum-nuclear geometry and temporal evolution.
Specifically, at low Eddington ratios (log lamEdd < -2), obscured AGN outnumber
unobscured ones by a factor of ~4, reflecting the covering factor of the
circum-nuclear material (0.8, or a torus opening angle of ~ 34 degrees). At
high Eddington ratios (\log lamEdd > -1), the trend is reversed, with < 30% of
AGN having log NH > 22, which we suggest is mainly due to the small fraction of
time spent in a highly obscured state. Considering the Eddington ratio
distribution function of narrow-line and broad-line AGN from our prior work, we
see a qualitatively similar picture. To disentangle temporal and geometric
effects at high lamEdd, we explore plausible clearing scenarios such that the
time-weighted covering factors agree with the observed population ratio. We
find that the low fraction of obscured AGN at high lamEdd is primarily due to
the fact that the covering factor drops very rapidly, with more than half the
time is spent with < 10% covering factor. We also find that nearly all obscured
AGN at high-lamEdd exhibit some broad-lines. We suggest that this is because
the height of the depleted torus falls below the height of the broad-line
region, making the latter visible from all lines of sight.Comment: Accepted by ApJ
Genetic characterization of a red color morph of Euphorbia esula subsp. esula (Euphorbiaceae) in the floodplains of Saône (Eastern France)
A new morph of leafy spurge, Euphorbia esula L., was discovered in the floodplains of the Val de Saône (VDS), France. In this region, this emerging weed shows two different morph colours: the common “green” variant and a rarer “red” variant. We compared the sequence data for the plastid trnT–trnF region among individuals of both morphs from the VDS, as well as other populations from Europe and North America, where this plant is invasive. In addition, we analysed the ploidy found among VDS individuals for both colours. Results showed that both morphs share two of the three chloroplast DNA (cpDNA) haplotypes found in the VDS and are both hexaploids (2n=6x = 60). These results suggest that the red morph is only an environmental variant of E. esula subsp. esula. Our results indicate that leafy spurge infestations in this region form a genetically diverse structuring composed of three cpDNA haplotypes, two of which are shared by the two morphs. (Résumé d'auteur
A new Aceria species (Acari: Trombidiformes: Eriophyoidea) from West Asia, a potential biological control agent for the invasive weed camelthorn, Alhagi maurorum Medik. (Leguminosae)
A new species of eriophyoid mite Aceria alhagi n. sp. inhabiting the weed Alhagi maurorum Medik., is described from the type locality in Iran, but it was also collected from Uzbekistan, Turkey and Armenia. This mite causes changes of the leaves and inflorescence. Infested plants develop cauliflower- like galls on the inflorescence and leaves deforming the reproductive structures and inhibiting seed production. The potential reduction in seed set suggests that this mite could constitute a potential biological control agent against this noxious weed. To investigate intraspecific variability between A. alhagi n. sp. populations from Iran, Turkey and Armenia, we analysed molecular sequences of the mitochondrial cytochrome oxidase subunit I (mtCOI). These results indicated that there are no significant intraspecific divergences among populations of A. alhagi n. sp. from the five different localities in three West Asia countries. This finding can be used in the future research of certain mite populations as biological control agent
The 2nd Workshop on Active Internet Measurements (AIMS-2) Report
On February 8-10, 2010, CAIDA hosted the second Work- shop on Active Internet Measurements (AIMS-2) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. The goals of this workshop were to further our understanding of the potential and limitations of active mea- surement research and infrastructure in the wide-area Inter- net, and to promote cooperative solutions and coordinated strategies to addressing future data needs of the network and security research communities. The three-day workshop included presentations, group discussion and analysis, and focused interaction between participating researchers, oper- ators, and policymakers from all over the world. This report describes the motivation and findings of the workshop, and reviews progress on recommendations developed at the 1st Active Internet Measurements Workshop in 2009 [18]. Slides from the workshop presentations are available at [9]