13,526 research outputs found
On the free field realization of algebras
Defining the algebras as the commutant of certain screening charges a
special form for the classical generators is obtained which does not change
under quantisation. This enables us to give explicitly the first few generators
in a compact form for arbitrary algebras.Comment: 9 pages, Latex, reference added, to appear in Phys. Let.
Genetic survey of alveolar and cystic echinococcoses in Romania: first molecular evidence of Echinococcus multilocularis in humans in the country
Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are considered as one of the most
important zoonotic diseases in Romania, where they are subject to mandatory reporting. To obtain
more knowledge about the genetic diversity of Echinococcus causative agents of these diseases, 11
isolates from humans and ungulate intermediate hosts from the two regions of Romania were genotyped
using mitochondrial markers. In clinical samples of fi ve patients from north-eastern Romania
(Iasi, Botosani, Vaslui counties), Echinococcus multilocularis was identifi ed as causal agent by cox1
sequence analysis. To the best of our knowledge this fi nding presents the fi rst molecular evidence
of E. multilocularis in humans from Romania. Only two cases of AE in patients were previously documented
in the country by serological methods. In our four patients the most widespread European
variant E5 of E. multilocularis was recorded, whereas in isolate from Vaslui county three nucleotide
substitutions were detected as compared to the most related E5 haplotype. One of these mutations
(411T/G) matched N1 and N2 haplotypes described previously from North America. In six CE samples
retrieved from western Romania (Caras-Severin and Timis counties), two human isolates were
diagnosed as Echinococcus canadensis G7, one as E. granulosus s.s. G1 and one as E. granulosus
s.s. G3 using atp6 and rrnS sequencing. In ungulates, the cattle isolate was allocated to E. granulosus
s.s. G1 and pig isolate to E. canadensis G7. The two G7 fi ndings in humans reinforced the
recent view that G7 was underestimated as compared to the E. granulosus s.s. regarding human
CE threat that can be further employed for identifying sources of infections and establishing suitable
preventive measures
Token Jumping in minor-closed classes
Given two -independent sets and of a graph , one can ask if it
is possible to transform the one into the other in such a way that, at any
step, we replace one vertex of the current independent set by another while
keeping the property of being independent. Deciding this problem, known as the
Token Jumping (TJ) reconfiguration problem, is PSPACE-complete even on planar
graphs. Ito et al. proved in 2014 that the problem is FPT parameterized by
if the input graph is -free.
We prove that the result of Ito et al. can be extended to any
-free graphs. In other words, if is a -free
graph, then it is possible to decide in FPT-time if can be transformed into
. As a by product, the TJ-reconfiguration problem is FPT in many well-known
classes of graphs such as any minor-free class
New aspects of the Z Z-graded 1D superspace: induced strings and 2D relativistic models
A novel feature of the -graded
supersymmetry which finds no counterpart in ordinary supersymmetry is the
presence of -graded exotic bosons (implied by the existence of two classes
of parafermions). Their interpretation, both physical and mathematical,
presents a challenge. The role of the "exotic bosonic coordinate" was not
considered by previous works on the one-dimensional -graded superspace (which was restricted to produce
point-particle models). By treating this coordinate at par with the other
graded superspace coordinates new consequences are obtained. The graded
superspace calculus of the -graded worldline
super-Poincar\'e algebra induces two-dimensional -graded relativistic models; they are invariant under a new -graded super-Poincar\'e algebra which differs
from the previous two -graded versions
of super-Poincar\'e introduced in the literature. In this new superalgebra the
second translation generator and the Lorentz boost are -graded.
Furthermore, if the exotic coordinate is compactified on a circle ,
a -graded closed string with periodic
boundary conditions is derived. The analysis of the irreducibility conditions
of the supermultiplet implies that a larger -deformed, where
is a real parameter) class of point-particle models than the ones
discussed so far in the literature (recovered at ) is obtained. While
the spectrum of the point-particle models is degenerate (due to its
relation with an supersymmetry), this is no longer the case for
the models.Comment: 28 page
Effect of calcium phosphate compound (MZF-CaP) with and without fluoride in preventing bone loss in ovariectomized rats
Zinc (Zn) has been shown to inhibit osteoclast differentiation, promote osteoblast activity, and enhance the bone formation. Zinc-containing calcium phosphate (Zn-TCP) implanted in rabbit femoral defect was demonstrated to stimulate bone formation. Other studies demonstrated that calcium phosphate compounds (MZF-CaP) incorporating magnesium (Mg2+), zinc and fluoride (F-) when administered either by injection or orally were effective in preventing bone loss (osteoporosis) induced by estrogen deficiency (ovariectomy) in a rat model. The objective of the present study was to investigate the preventive effect of similar compound, with F (MZF-CaP-L, MZF-CaP-H) and without F (MZ-CaP-L), when injected in ovariectomized (OVX) rats. MZF-CaP-L and MZ-CaP-L were prepared by precipitation at 90oC and MZF-CaP-H was prepared by sintering MZF-CaP-L at 900oC. The release of the ions from acidic buffer was determined. Suspensions of Zn-TCP, MZF-CaP-H, MZF-CaP-L and MZ-CaP-L (617 μg in 0.2 ml of 1% sodium alginate saline solution) were injected intramuscularly under anesthesia into 5-week-old OVX rats on Zn-deficient diet. One week after surgery, bone mineral density (BMD) and bone mineral content (BMC) of the rat femurs were measured using X-ray CT. The injections and X-ray CT and Zn ion plasma measurements were repeated every week for 12 weeks. The rats were sacrificed and the femurs removed after 12 weeks. Bone mechanical strength was evaluated using the three-point bending test. MZ-CaP-L (without F), compared to the other compounds, showed the highest increase in the Zn2+ ion plasma concentration, and the highest BMD, BMC and mechanical strength
Short-time Critical Dynamics of the 3-Dimensional Ising Model
Comprehensive Monte Carlo simulations of the short-time dynamic behaviour are
reported for the three-dimensional Ising model at criticality. Besides the
exponent of the critical initial increase and the dynamic exponent
, the static critical exponents and as well as the critical
temperature are determined from the power-law scaling behaviour of observables
at the beginning of the time evolution. States of very high temperature as well
as of zero temperature are used as initial states for the simulations.Comment: 8 pages with 7 figure
Difference system for Selberg correlation integrals
The Selberg correlation integrals are averages of the products
with respect to the Selberg
density. Our interest is in the case , , when this
corresponds to the -th moment of the corresponding characteristic
polynomial. We give the explicit form of a matrix linear
difference system in the variable which determines the average, and we
give the Gauss decomposition of the corresponding matrix.
For a positive integer the difference system can be used to efficiently
compute the power series defined by this average.Comment: 21 page
Tunable Oscillations in the Purkinje Neuron
In this paper, we study the dynamics of slow oscillations in Purkinje neurons
in vitro, and derive a strong association with a forced parametric oscillator
model. We demonstrate the precise rhythmicity of the oscillations in Purkinje
neurons, as well as a dynamic tunability of this oscillation using a
photo-switchable compound. We show that this slow oscillation can be induced in
every Purkinje neuron, having periods ranging between 10-25 seconds. Starting
from a Hodgkin-Huxley model, we also demonstrate that this oscillation can be
externally modulated, and that the neurons will return to their intrinsic
firing frequency after the forced oscillation is concluded. These results
signify an additional functional role of tunable oscillations within the
cerebellum, as well as a dynamic control of a time scale in the brain in the
range of seconds.Comment: 12 pages, 5 figure
- …