636 research outputs found
Current range characteristics of Swiss stone pine (Pinus cembra L.) along the Carpathians revealed by chloroplast SSR markers.
We investigated the diversity pattern of nine Swiss stone pine (Pinus cembra L.) populations along the
Carpathian range including the High Tatras, by using six chloroplast DNA microsatellites (cpSSR). Our
aim was to detect genetically distinct regions by clustering of populations, and to tackle possible historical
colonization routes. Our analysis referred to an investigated geographical range with the two most
distant populations situated at about 500 air km. We found that the most diverse populations are situated
at the two edges of the investigated part, in the Retezat Mts. (South Carpathians) and the High Tatras, and
diversity decreases towards the populations of the Eastern Carpathians. Hierarchical clustering and
NMDS revealed that the populations of the South Carpathians with the Tatras form a distinct cluster,
significantly separated from those of the Eastern Carpathians. Moreover, based on the most variable
chloroplast microsatellites, the four populations of the two range edges are not significantly different. Our
results, supported also by palynological and late glacial macrofossil evidences, indicate refugial territories
within the Retezat Mts. that conserved rich haplotype composition. From this refugial territory Pinus
cembra might have colonized the Eastern Carpathians, and this was accompanied by a gradual decrease
in population diversity. Populations of the High Tatras might have had the same role in the colonizing
events of the Carpathians, as positive correlation was detected among populations lying from each other
at a distance of 280 km, the maximum distance between neighbouring populations
On Nichols algebras associated to simple racks
This is a report on the present state of the problem of determining the
dimension of the Nichols algebra associated to a rack and a cocycle. This is
relevant for the classification of finite-dimensional complex pointed Hopf
algebras whose group of group-likes is non-abelian. We deal mainly with simple
racks. We recall the notion of rack of type D, collect the known lists of
simple racks of type D and include preliminary results for the open cases. This
notion is important because the Nichols algebra associated to a rack of type D
and any cocycle has infinite dimension. For those racks not of type D, the
computation of the cohomology groups is needed. We discuss some techniques for
this problem and compute explicitly the cohomology groups corresponding to some
conjugacy classes in symmetric or alternating groups of low order.Comment: 26 pages, minor change
On Nichols algebras over SL(2,Fq) and GL(2,Fq)
We compute necessary conditions on Yetter-Drinfeld modules over the groups
SL(2,Fq) and GL(2,Fq) to generate finite dimensional Nichols algebras. This is
a first step towards a classification of pointed Hopf algebras with a group of
group-likes isomorphic to one of these groups.Comment: Major exposition revision, including referees remarks. To appear in
J. Math. Phys. 13 page
Using reduced representation libraries sequencing methods to identify cpDNA polymorphisms in European beech (Fagus sylvatica L)
Reduced representation genomic libraries (RRLs) are increasingly used to answer diverse questions in evolutionary biology, which remained unresolved otherwise. In the case of European beech (Fagus sylvatica L.), former applications of nuclear and chloroplast genetic markers indicated that most of the beech populations of Central, Eastern, and Northern Europe have a very homogeneous genetic structure. Thus, determining differentiation among populations of F. sylvatica at regional scale in Central Europe has remained a challenge for evolutionary biologists, mainly due to lack of variable genetic markers. In this study, we used the RAD-seq and GBS approaches to identify novel cpDNA polymorphisms that could be helpful to identify population structure of European beech at geographical scale. Our datasets allowed us to indicate a finer population structure and stronger patterns of spatial genetic structure than previous studies. It is expected that the applications of cpDNA-based phylogenetic approaches using whole-genome sequencing are able to provide even more detailed picture of species phylogeography than ever before
Electric dipole and magnetic quadrupole moments of the boson via a CP-violating vertex in effective Lagrangians
The possibility of nonnegligible electric dipole ()
and magnetic quadrupole () moments induced by the most general
vertex is examined via the effective Lagrangian technique. It is assumed
that new heavy fermions induce an anomalous CP-odd component of the
vertex, which can be parametrized by an -invariant
dimension-six operator. This anomalous contribution, when combined with the
standard model CP-even contribution, lead to CP-odd electromagnetic properties
of the boson, which are characterized by the form factors and . It is found that is divergent, whereas is finite,
which reflects the fact that the latter cannot be generated at the one-loop
level in any renormalizable theory. Assuming reasonable values for the unknown
parameters, we found that e-cm,
which is eight orders of magnitude larger than the SM prediction and close to
the upper bound derived from the neutron electric dipole moment. The estimated
size of the somewhat less-studied moment is of the order of
e-cm^2, which is fifteen orders of magnitude above the SM
contribution.Comment: 7 pages, 6 figures, REVTEX styl
Mid-Pleistocene and Holocene demographic fluctuation of Scots pine (Pinus sylvestris L.) in the Carpathian Mountains and the Pannonian Basin: Signs of historical expansions and contractions
Climate fluctuations of the Quaternary caused radical changes in distribution of tree species and resulted in large-scale range shifts, population contractions and expansions. Scots pine (Pinus sylvestris L.) a widely distributed conifer of the boreal regions underwent spatio-temporal changes, which shaped the modern-day genetic structure and phylogeographic pattern of the species. By applying independent approaches, including molecular genetic data and historical climate models we aimed to describe demography and past distribution patterns of Scots pine populations from the highly fragmented southern periphery, the Carpathians and the Pannonian Basin. We used Approximate Bayesian Computation (ABC) approach based on nuclear microsatellite markers (nSSRs) and Maximum Entropy distribution modelling (MaxEnt) with temperature- and precipitation-related bioclimatic data. ABC results indicated that from an ancestral Scots pine population two genetic lineages have diverged that in the Mid-Pleistocene due to the favourable climatic conditions underwent population expansion leading to an admixture event. The outcome of the hindcasting confirmed the expansion that leaded to the admixture event revealed by the ABC analysis. This can be dated to the Late Glacial period (14,160–11,800 yrs BP), in which widespread distribution of Scots pine in accordance with palynological proxies was detected. Predictions for the Mid-Holocene period have shown large-scale reduction in distribution of Scots pine and low probability of its occurrence, leading to disjunction and population fragmentation
CP-odd static electromagnetic properties of the W gauge boson and the t quark via the anomalous tbW coupling
In the framework of the electroweak chiral Lagrangian, the one-loop induced
effects of the anomalous coupling, which includes both left- and
right-handed complex components, on the static electromagnetic properties of
the boson and the quark are studied. The attention is focused mainly on
the CP-violating electromagnetic properties. It is found that the
anomalous coupling can induce both CP-violating moments of the boson,
namely, its electric dipole () and magnetic quadrupole
() moments. As far as the quark is concerned, a potentially
large electric dipole moment can arise due to the anomalous
coupling. The most recent bounds on the left- and right-handed parameters from
meson physics lead to the following estimates e-cm and e-cm, which
are 7 and 14 orders of magnitude larger than the standard model (SM)
predictions, whereas may be as large as e-cm, which is about 8
orders of magnitude larger than its SM counterpart.Comment: This paper has been merged with hep-ph/0612171 for publication in
Physical Review
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