11 research outputs found
The influence of strong magnetic field on photon-neutrino reactions
The two-photon two-neutrino interaction induced by magnetic field is
investigated. In particular the processes and
are studied in the presence of strong magnetic
field. An effective Lagrangian and partial amplitudes of the processes are
presented. Neutrino emissivities due to the reactions and are calculated taking into
account of the photon dispersion and large radiative corrections. A comparison
of the results obtained with previous estimations and another inducing
mechanisms of the processes under consideration is made.Comment: 16 pages, LATEX, 3 EPS figures, based on the talk presented at XXXI
ITEP Winter School of Physics, Moscow, Russia, February 18 - 26, 200
45S rDNA external transcribed spacer organization reveals new phylogenetic relationships in Avena genus
Research ArticleThe genus Avena comprises four distinct genomes organized in diploid (AA or CC), tetraploid
(AABB or AACC) and hexaploid species (AACCDD), constituting an interesting model
for phylogenetic analysis. The aim of this work was to characterize 45S rDNA intergenic
spacer (IGS) variability in distinct species representative of Avena genome diversity±A.
strigosa (AA), A. ventricosa (CvCv), A. eriantha (CpCp), A. barbata (AABB), A. murphyi
(AACC), A. sativa (AACCDD) and A. sterilis (AACCDD) through the assessment of the 5'
external transcribed spacer (5'-ETS), a promising IGS region for phylogenetic studies poorly
studied in Avena genus. In this work, IGS length polymorphisms were detected mainly due
to distinct 5'-ETS sequence types resulting from major differences in the number and organization
of repeated motifs. Although species with A genome revealed a 5'-ETS organization
(A-organization) similar to the one previously described in A. sativa, a distinct organization
was unraveled in C genome diploid species (C-organization). Interestingly, such new organization
presents a higher similarity with other Poaceae species than A-genome sequences,
supporting the hypothesis of C-genome being the ancestral Avena genome. Additionally,
polyploid species with both genomes mainly retain the A-genome 5'-ETS organization, confirming
the preferential elimination of C-genome sequences in Avena polyploid species.
Moreover, 5'-ETS sequences phylogenetic analysis consistently clustered the species studied
according to ploidy and genomic constitution supporting the use of ribosomal genes to
highlight Avena species evolutive pathways.info:eu-repo/semantics/publishedVersio