541 research outputs found
A sharp growth condition for a fast escaping spider's web
We show that the fast escaping set of a transcendental entire function
has a structure known as a spider's web whenever the maximum modulus of
grows below a certain rate. We give examples of entire functions for which the
fast escaping set is not a spider's web which show that this growth rate is
best possible. By our earlier results, these are the first examples for which
the escaping set has a spider's web structure but the fast escaping set does
not. These results give new insight into a conjecture of Baker and a conjecture
of Eremenko
Probing the extremes of Seyfert activity: BeppoSAX observations of Narrow-Line Seyfert 1 galaxies
Results are presented for the first year of observations of a selected sample
of Narrow-Line Seyfert 1 galaxies (Ton S 180, RE J1034+396, Ark 564) obtained
with the imaging instruments onboard BeppoSAX. These are the first simultaneous
broad band (0.1--10 keV) spectra so far obtained for this class of objects.Comment: Contributed Talk, to appear in : The Active X-ray Sky: Results from
BeppoSAX and Rossi-XTE, Nuclear Physics B Proceedings Supplements, L. Scarsi,
H. Bradt, P. Giommi and F. Fiore (eds.), Elsevier Science B.V. 6 pages LateX
and 8 ps figures, using espcrc2 and epsfi
Partial Schauder estimates for second-order elliptic and parabolic equations
We establish Schauder estimates for both divergence and non-divergence form
second-order elliptic and parabolic equations involving H\"older semi-norms not
with respect to all, but only with respect to some of the independent
variables.Comment: CVPDE, accepted (2010)
Clinical symptoms of androgen deficiency in men with migraine or cluster headache: a cross-sectional cohort study
Background To compare symptoms of clinical androgen deficiency between men with migraine, men with cluster headache and non-headache male controls. Methods We performed a cross-sectional study using two validated questionnaires to assess symptoms of androgen deficiency in males with migraine, cluster headache, and non-headache controls. Primary outcome was the mean difference in androgen deficiency scores. Generalized linear models were used adjusting for age, BMI, smoking and lifetime depression. As secondary outcome we assessed the percentage of patients reporting to score below average on four sexual symptoms (beard growth, morning erections, libido and sexual potency) as these items were previously shown to more specifically differentiate androgen deficiency symptoms from (comorbid) anxiety and depression. Results The questionnaires were completed by n = 534/853 (63%) men with migraine, n = 437/694 (63%) men with cluster headache and n = 152/209 (73%) controls. Responders were older compared to non-responders and more likely to suffer from lifetime depression. Patients reported more severe symptoms of clinical androgen deficiency compared with controls, with higher AMS scores (Aging Males Symptoms; mean difference +/- SE: migraine 5.44 +/- 0.90, p < 0.001; cluster headache 5.62 +/- 0.99, p < 0.001) and lower qADAM scores (quantitative Androgen Deficiency in the Aging Male; migraine: - 3.16 +/- 0.50, p < 0.001; cluster headache: - 5.25 +/- 0.56, p < 0.001). Additionally, both patient groups more often reported to suffer from any of the specific sexual symptoms compared to controls (18.4% migraine, 20.6% cluster headache, 7.2% controls, p = 0.001). Conclusion Men with migraine and cluster headache more often suffer from symptoms consistent with clinical androgen deficiency than males without a primary headache disorder.Paroxysmal Cerebral Disorder
Nonlinear electrodynamics of p-wave superconductors
We consider the Maxwell-London electrodynamics of three dimensional
superconductors in p-wave pairing states with nodal points or lines in the
energy gap. The current-velocity relation is then nonlinear in the applied
field, cubic for point nodes and quadratic for lines. We obtain explicit
angular and depth dependent expressions for measurable quantities such as the
transverse magnetic moment, and associated torque. These dependences are
different for point and line nodes and can be used to distinguish between
different order parameters. We discuss the experimental feasibility of this
method, and bring forth its advantages, as well as limitations that might be
present.Comment: Fourteen pages RevTex plus four postscript figure
Proposal of an experimental scheme for realising a translucent eavesdropping on a quantum cryptographic channel
Purpose of this paper is to suggest a scheme, which can be realised with
today's technology and could be used for entangling a probe to a photon qubit
based on polarisation. Using this probe a translucent or a coherent
eavesdropping can be performed.Comment: in pres
Timed fetal inflammation and postnatal hypoxia cause cortical white matter injury, interneuron imbalances, and behavioral deficits in a double-hit rat model of encephalopathy of prematurity
Extreme preterm birth-associated adversities are a major risk factor for aberrant brain development, known as encephalopathy of prematurity (EoP), which can lead to long-term neurodevelopmental impairments. Although progress in clinical care for preterm infants has markedly improved perinatal outcomes, there are currently no curative treatment options available to combat EoP. EoP has a multifactorial etiology, including but not limited to pre- or postnatal immune activation and oxygen fluctuations. Elucidating the underlying mechanisms of EoP and determining the efficacy of potential therapies relies on valid, clinically translatable experimental models that reflect the neurodevelopmental and pathophysiological hallmarks of EoP. Here, we expand on our double-hit rat model that can be used to study EoP disease mechanisms and therapeutic options in a preclinical setting. Pregnant Wistar dams were intraperitoneally injected with 10 μg/kg LPS on embryonic day (E)20 and offspring was subjected to hypoxia (140 min, 8% O2) at postnatal day 4. Rats exposed to fetal inflammation and postnatal hypoxia (FIPH) showed neurodevelopmental impairments, such as reduced nest-seeking ability, ultrasonic vocalizations, social engagement, and working memory, and increased anxiety and sensitivity. Impairments in myelination, oligodendrocyte maturation and interneuron development were examined as hallmarks for EoP, in different layers and coordinates of the cortex using histological and molecular techniques. Myelin density and complexity was decreased in the cortex, which partially coincided with a decrease in mature oligodendrocytes. Furthermore, interneuron populations (GAD67+ and PVALB+) were affected. To determine if the timing of inducing fetal inflammation affected the severity of EoP hallmarks in the cortex, multiple timepoints of fetal inflammation were compared. Inflammation at E20 combined with postnatal hypoxia gave the most severe EoP phenotype in the cortex. In conclusion, we present a double-hit rat model which displays various behavioral, anatomical and molecular hallmarks of EoP, including diffuse white matter injury. This double-hit model can be used to investigate pathophysiological mechanisms and potential therapies for EoP
Connecting Numerical Relativity and Data Analysis of Gravitational Wave Detectors
Gravitational waves deliver information in exquisite detail about
astrophysical phenomena, among them the collision of two black holes, a system
completely invisible to the eyes of electromagnetic telescopes. Models that
predict gravitational wave signals from likely sources are crucial for the
success of this endeavor. Modeling binary black hole sources of gravitational
radiation requires solving the Eintein equations of General Relativity using
powerful computer hardware and sophisticated numerical algorithms. This
proceeding presents where we are in understanding ground-based gravitational
waves resulting from the merger of black holes and the implications of these
sources for the advent of gravitational-wave astronomy.Comment: Appeared in the Proceedings of 2014 Sant Cugat Forum on Astrophysics.
Astrophysics and Space Science Proceedings, ed. C.Sopuerta (Berlin:
Springer-Verlag
Endothelial loss of Fzd5 stimulates PKC/Ets1-mediated transcription of Angpt2 and Flt1
Aims: Formation of a functional vascular system is essential and its formation is a highly regulated process initiated during embryogenesis, which continues to play important roles throughout life in both health and disease. In previous studies, Fzd5 was shown to be critically involved in this process and here we investigated the molecular mechanism by which endothelial loss of this receptor attenuates angiogenesis. Methods and results: Using short interference RNA-mediated loss-of-function assays, the function and mechanism of signaling via Fzd5 was studied in human endothelial cells (ECs). Our findings indicate that Fzd5 signaling promotes neovessel formation in vitro in a collagen matrix-based 3D co-culture of primary vascular cells. Silencing of Fzd5 reduced EC proliferation, as a result of G0/G1 cell cycle arrest, and decreased cell migration. Furthermore, Fzd5 knockdown resulted in enhanced expression of the factors Angpt2 and Flt1, which are mainly known for their destabilizing effects on the vasculature. In Fzd5-silenced ECs, Angpt2 and Flt1 upregulation was induced by enhanced PKC signaling, without the involvement of canonical Wnt signaling, non-canonical Wnt/Ca2+-mediated activation of NFAT, and non-canonical Wnt/PCP-mediated activation of JNK. We demonstrated that PKC-induced transcription of Angpt2 and Flt1 involved the transcription factor Ets1. Conclusions: The current study demonstrates a pro-angiogenic role of Fzd5, which was shown to be involved in endothelial tubule formation, cell cycle progression and migration, and partly does so by repression of PKC/Ets1-mediated transcription of Flt1 and Angpt2
Expansion of Vortex Cores by Strong Electronic Correlation in LaSrCuO at Low Magnetic Induction
The vortex core radius \rv, defined as the peak position of the supercurrent
around the vortex, has been determined by muon spin rotation measurements in
the mixed state of \lscox for , 0.15, and 0.19. At lower doping (x=0.13
and 0.15), \rv(T) increases with decreasing temperature T, which is opposite to
the behavior predicted by the conventional theory. Moreover, \rv(T\to0) is
significantly larger than the Ginsburg-Landau coherence length determined by
the upper critical field, and shows a clear tendency to decrease with
increasing the doping x. These features can be qualitatively reproduced in a
microscopic model involving antiferromagnetic electronic correlations.Comment: 6 pages, 4 figures, to be published in Phys. Rev.
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