7,214 research outputs found
Chiral doublings of heavy-light hadrons: New charmed mesons discovered by BABAR,CLEO and BELLE
We remind the chiral doubling scenario [1,2] for hadrons built of heavy and
light quarks. Then we recall arguments why new states
D_s(2317),D_s(2460),D_0(2308) and D_1^'(2427) should be viewed as chiral
partners of D_s,D_s^*,D and D^*,respectively. We summarize with the list of
predictions based on chiral doubling scenario for other heavy-light hadrons.Comment: Talk at Hadron'03, Aschaffenburg, Germany, August 31st - September
6th, 2003. (5 pages, 1 figure
Probing non-orthogonality of eigenvectors in non-Hermitian matrix models: diagrammatic approach
Using large arguments, we propose a scheme for calculating the two-point
eigenvector correlation function for non-normal random matrices in the large
limit. The setting generalizes the quaternionic extension of free
probability to two-point functions. In the particular case of biunitarily
invariant random matrices, we obtain a simple, general expression for the
two-point eigenvector correlation function, which can be viewed as a further
generalization of the single ring theorem. This construction has some striking
similarities to the freeness of the second kind known for the Hermitian
ensembles in large . On the basis of several solved examples, we conjecture
two kinds of microscopic universality of the eigenvectors - one in the bulk,
and one at the rim. The form of the conjectured bulk universality agrees with
the scaling limit found by Chalker and Mehlig [JT Chalker, B Mehlig, PRL,
\textbf{81}, 3367 (1998)] in the case of the complex Ginibre ensemble.Comment: 20 pages + 4 pages of references, 12 figs; v2: typos corrected, refs
added; v3: more explanator
The physiological response of Populus tremula x alba leaves to the down-regulation of PIP1 aquaporin gene expression under no water stress.
In order to study the role of PIP1 aquaporins in leaf water and CO2 transport, several lines of PIP1-deficient transgenic Populus tremula x alba were generated using a reverse genetic approach. These transgenic lines displayed no visible developmental or morphological phenotypes when grown under conditions of no water stress. Major photosynthetic parameters were also not affected by PIP1 down regulation. However, low levels of PIP1 expression resulted in greater leaf hydraulic resistance (an increase of 27%), which effectively implicated PIP1 role in water transport. Additionally, the expression level of PIP1 genes in the various transgenic lines was correlated with reductions in mesophyll conductance to CO2 (gm), suggesting that in poplar, these aquaporins influenced membrane permeability to CO2. Overall, although analysis showed that PIP1 genes contributed to the mass transfer of water and CO2 in poplar leaves, their down-regulation did not dramatically impair the physiological needs of this fast growing tree when cultivated under conditions of no stress
Spectra of large time-lagged correlation matrices from Random Matrix Theory
We analyze the spectral properties of large, time-lagged correlation matrices
using the tools of random matrix theory. We compare predictions of the
one-dimensional spectra, based on approaches already proposed in the
literature. Employing the methods of free random variables and diagrammatic
techniques, we solve a general random matrix problem, namely the spectrum of a
matrix , where is an Gaussian random
matrix and is \textit{any} , not necessarily symmetric
(Hermitian) matrix. As a particular application, we present the spectral
features of the large lagged correlation matrices as a function of the depth of
the time-lag. We also analyze the properties of left and right eigenvector
correlations for the time-lagged matrices. We positively verify our results by
the numerical simulations.Comment: 44 pages, 11 figures; v2 typos corrected, final versio
Zielonka's Recursive Algorithm: dull, weak and solitaire games and tighter bounds
Dull, weak and nested solitaire games are important classes of parity games,
capturing, among others, alternation-free mu-calculus and ECTL* model checking
problems. These classes can be solved in polynomial time using dedicated
algorithms. We investigate the complexity of Zielonka's Recursive algorithm for
solving these special games, showing that the algorithm runs in O(d (n + m)) on
weak games, and, somewhat surprisingly, that it requires exponential time to
solve dull games and (nested) solitaire games. For the latter classes, we
provide a family of games G, allowing us to establish a lower bound of 2^(n/3).
We show that an optimisation of Zielonka's algorithm permits solving games from
all three classes in polynomial time. Moreover, we show that there is a family
of (non-special) games M that permits us to establish a lower bound of 2^(n/3),
improving on the previous lower bound for the algorithm.Comment: In Proceedings GandALF 2013, arXiv:1307.416
Strategy Derivation for Small Progress Measures
Small Progress Measures is one of the most efficient parity game solving
algorithms. The original algorithm provides the full solution (winning regions
and strategies) in
time, and requires a re-run of the algorithm on one of the winning regions. We
provide a novel operational interpretation of progress measures, and modify the
algorithm so that it derives the winning strategies for both players in one
pass. This reduces the upper bound on strategy derivation for SPM to .Comment: polished the tex
Functional analysis of embolism induced by air injection in Acer rubrum and Salix nigra.
The goal of this study was to assess the effect of induced embolism with air injection treatments on the function of xylem in Acer rubrum L. and Salix nigra Marsh. Measurements made on mature trees of A. rubrum showed that pneumatic pressurization treatments that created a pressure gradient of 5.5 MPa across pit membranes (ΔP pit) had no effect on stomatal conductance or on branch-level sap flow. The same air injection treatments made on 3-year-old potted A. rubrum plants also had no effect on whole plant transpiration. A separate study made on mature A. rubrum trees showed that 3.0 and 5.5 MPa of ΔP pit values resulted in an immediate 100% loss in hydraulic conductance (PLC) in petioles. However, the observed change in PLC was short lived, and significant hydraulic recovery occurred within 5-10 min post air-pressurization treatments. Similar experiments conducted on S. nigra plants exposed to ΔP pit of 3 MPa resulted in a rapid decline in whole plant transpiration followed by leaf wilting and eventual plant death, showing that this species lacks the ability to recover from induced embolism. A survey that measured the effect of air-pressurization treatments on seven other species showed that some species are very sensitive to induction of embolism resulting in leaf wilting and branch death while others show minimal to no effect despite that in each case, the applied ΔP pit of 5.5 MPa significantly exceeded any native stress that these plants would experience naturally
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