163 research outputs found
Feller property and infinitesimal generator of the exploration process
We consider the exploration process associated to the continuous random tree
(CRT) built using a Levy process with no negative jumps. This process has been
studied by Duquesne, Le Gall and Le Jan. This measure-valued Markov process is
a useful tool to study CRT as well as super-Brownian motion with general
branching mechanism. In this paper we prove this process is Feller, and we
compute its infinitesimal generator on exponential functionals and give the
corresponding martingale
Dolichandrone platycalyx: New entomophilous pollen-A report on pollen sensitization in allergic individuals
Background: Dolichandrone platycalyx, commonly known as Nile trumpet tree, is believed to have originated in East Africa. However, this and the variants of this tree are found in Europe, Asia, and America (California and Florida). The tree mostly grows in tropical climates, but temperate species are also found. This study was designed to evaluate the allergenicity of D. platycalyx, one of the most common entomophilous avenue trees in Karnataka state, and to determine the pollen production of D. platycalyx.
Methods: All of the patients with allergic rhinitis and asthma attending a tertiary care center in South India during August 2007 to March 2008 underwent a detailed clinical evaluation and skin-prick testing to common allergens along with D. platycalyx. Control subjects without any symptoms of respiratory allergy also underwent skin testing. The pollen counts were determined for a mature unopened flower of D. platycalyx.
Results: A total of 317 subjects with respiratory allergy and 30 controls were included in the study. A significant percentage (16.1%) of patients evaluated were observed to be sensitive to Dolichandrone pollen extract by skin-prick testing, whereas none of the control subjects were found to be sensitized. D. platycalyx was the fourth most common sensitizer after Parthenium hysterophorus, Prosopis juliflora, and Artemesia vulgaris. D. platycalyx was found to be a moderate pollen producer at 66,000 pollens/flower.
Conclusion: Sensitization to D. platycalyx is common in subjects with respiratory allergies. The clinical relevance of this sensitization and other entomophilous plants needs additional study. (Am J Rhinol Allergy 25, e34-e38, 2011; doi: 10.2500/ajra.2011.25.3579
Persistent currents with long-range hopping in 1D single-isolated-diffusive rings
We show from exact calculations that a simple tight-binding Hamiltonian with
diagonal disorder and long-range hopping integrals, falling off as a power
of the inter-site separation, correctly describes the experimentally
observed amplitude (close to the value of an ordered ring) and flux-periodicity
() of persistent currents in single-isolated-diffusive normal metal rings
of mesoscopic size. Long-range hopping integrals tend to delocalize the
electrons even in the presence of disorder resulting orders of magnitude
enhancement of persistent current relative to earliar predictions.Comment: 4 pages, 3 figure
Strange behavior of persistent currents in small Hubbard rings
We show exactly that small Hubbard rings exhibit unusual kink-like structures
giving anomalous oscillations in persistent current. Singular behavior of
persistent current disappears in some cases. In half-filled systems mobility
gradually drops to zero with interaction, while it converges to some finite
value in non-half-filled cases.Comment: 7 pages, 6 figure
On the role of electron correlation and disorder on persistent currents in isolated one-dimensional rings
To understand the role of electron correlation and disorder on persistent
currents in isolated 1D rings threaded by magnetic flux , we study the
behavior of persistent currents in aperiodic and ordered binary alloy rings.
These systems may be regarded as disordered systems with well-defined
long-range order so that we do not have to perform any configuration averaging
of the physical quantities. We see that in the absence of interaction, disorder
suppresses persistent currents by orders of magnitude and also removes its
discontinuity as a function of . As we introduce electron correlation, we
get enhancement of the currents in certain disordered rings. Quite
interestingly we observe that in some cases, electron correlation produces
kink-like structures in the persistent current as a function of . This
may be considered as anomalous Aharonov-Bohm oscillations of the persistent
current and recent experimental observations support such oscillations. We find
that the persistent current converges with the size of the rings.Comment: 9 pages, 8 figure
Antigiardial activity of novel guanidine compounds
From four focused compound libraries based on the known anticoccidial agent robenidine, 44 compounds total were synthesised and screened for antigiardial activity. All active compounds were counter-screened for antibiotic and cytotoxic action. Of the analogues examined, 21 displayed IC50<5 μM, seven with IC50<1.0 μM. Most active were 2,2′-bis{[4-(trifluoromethoxy)phenyl]methylene}carbonimidic dihydrazide hydrochloride (30), 2,2′-bis{[4-(trifluoromethylsulfanyl)phenyl]methylene}carbonimidic dihydrazide hydrochloride (32), and 2,2′-bis[(2-bromo-4,5-dimethoxyphenyl)methylene]carbonimidic dihydrazide hydrochloride (41) with IC50=0.2 μM. The maximal observed activity was a 5 h IC50 value of 0.2 μM for 41. The clinically used metronidazole was inactive at this timepoint at a concentration of 25 μM. Robenidine off-target effects at bacteria and cell line toxicity were removed. Analogue 41 was well tolerated in mice treated orally (100 mg/kg). Following 5 h treatment with 41, no Giardia regrowth was noted after 48 h
Effective Operator Treatment of the Anharmonic Oscillator
We analyse the one dimensional quartic oscillator using the effective
operator methodology of Lee and Suzuki. We reproduce known results for low
lying energy eigenvalues.Comment: 9 Pages, Extended version with new references. To appear in
Phys.ReV.
The topological structure of scaling limits of large planar maps
We discuss scaling limits of large bipartite planar maps. If p is a fixed
integer strictly greater than 1, we consider a random planar map M(n) which is
uniformly distributed over the set of all 2p-angulations with n faces. Then, at
least along a suitable subsequence, the metric space M(n) equipped with the
graph distance rescaled by the factor n to the power -1/4 converges in
distribution as n tends to infinity towards a limiting random compact metric
space, in the sense of the Gromov-Hausdorff distance. We prove that the
topology of the limiting space is uniquely determined independently of p, and
that this space can be obtained as the quotient of the Continuum Random Tree
for an equivalence relation which is defined from Brownian labels attached to
the vertices. We also verify that the Hausdorff dimension of the limit is
almost surely equal to 4.Comment: 45 pages Second version with minor modification
Predicting CYP3A-mediated midazolam metabolism in critically ill neonates, infants, children and adults with inflammation and organ failure
Aims: Inflammation and organ failure have been reported to have an impact on cytochrome P450 (CYP) 3A-mediated clearance of midazolam in critically ill children. Our aim was to evaluate a previously developed population pharmacokinetic model both in critically ill children and other populations, in order to allow the model to be used to guide dosing in clinical practice. Methods: The model was evaluated externally in 136 individuals, including (pre)term neonates, infants, children and adults (body weight 0.77-90 kg, C-reactive protein level 0.1-341 mg l-1 and 0-4 failing organs) using graphical and numerical diagnostics. Results: The pharmacokinetic model predicted midazolam clearance and plasma concentrations without bias in postoperative or critically ill paediatric patients and term neonates [median prediction error (MPE) 180%). Conclusion: The recently published pharmacokinetic model for midazolam, quantifying the influence of maturation, inflammation and organ failure in children, yields unbiased clearance predictions and can therefore be used for dosing instructions in term neonates, children and adults with varying levels of critical illness, including healthy adults, but not for extrapolation to preterm neonates
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