Loss Dependence on Geometry and Applied Power in Superconducting Coplanar Resonators

The loss in superconducting microwave resonators at low-photon number and low temperatures is not well understood but has implications for achievable coherence times in superconducting qubits. We have fabricated single-layer resonators with a high quality factor by patterning a superconducting aluminum film on a sapphire substrate. Four resonator geometries were studied with resonant frequencies ranging from 5 to 7 GHz: a quasi-lumped element resonator, a coplanar strip waveguide resonator, and two hybrid designs that contain both a coplanar strip and a quasi-lumped element. Transmitted power measurements were taken at 30 mK as a function of frequency and probe power. We find that the resonator loss, expressed as the inverse of the internal quality factor, decreases slowly over four decades of photon number in a manner not merely explained by loss from a conventional uniform spatial distribution of two-level systems in an oxide layer on the superconducting surfaces of the resonator.Comment: 4 pages, 5 figures, Submitted to ASC 2010 conference proceeding

A node-wise analysis of the uterine muscle networks for pregnancy monitoring

The recent past years have seen a noticeable increase of interest in the correlation analysis of electrohysterographic (EHG) signals in the perspective of improving the pregnancy monitoring. Here we propose a new approach based on the functional connectivity between multichannel (4x4 matrix) EHG signals recorded from the women abdomen. The proposed pipeline includes i) the computation of the statistical couplings between the multichannel EHG signals, ii) the characterization of the connectivity matrices, computed by using the imaginary part of the coherence, based on the graph-theory analysis and iii) the use of these measures for pregnancy monitoring. The method was evaluated on a dataset of EHGs, in order to track the correlation between EHGs collected by each electrode of the matrix (called node-wise analysis) and follow their evolution along weeks before labor. Results showed that the strength of each node significantly increases from pregnancy to labor. Electrodes located on the median vertical axis of the uterus seemed to be the more discriminant. We speculate that the network-based analysis can be a very promising tool to improve pregnancy monitoring.Comment: 4 pages, 3 figures, accepted in the IEEE EMBC conferanc

Combining three in vitro assays for detecting early signs of UVB cytotoxicity in cultured human skin fibroblasts

The aim of this study was to determine the most sensitive approach for detecting the early signs of UVB-induced cellular damage using human skin fibroblasts. UVB-induced cell damage was assessed immediately and 24 h post irradiation using 3 in vitro colorimetric assays: neutral red (NR); 5-(3-carboxy-methoxyphenyl)- 2-(4.5-dimethylthiazolyl)-3-(4-sulphonyl) MTS; and (iii) LDH enzyme release. A good correlation was observed immediately post exposure between the MTS and NR in measuring damage levels, but was lost 24 h post exposure. This loss of correlation was the result of delayed expression of lysosomal damage and led to investigating cell membrane damage using LDH cell leakage assay. LDH levels observed immediately post UVB irradiation indicated significant LDH release at exposure doses of 2.2 and 2.8 J/cm 2 , while LDH release reported 24 h post exposure was recorded for doses as low as 0.70 J/cm 2 . The data reported in this paper indicated that cell viability and damage were significantly affected in a dose dependent manner as a result of exposure doses. The assays used displayed different sensitivities in detecting damage with the earliest signs of cellular UVB damage best-measured 24 h following exposure using the LDH assay. Furthermore UVB contributed to denaturing the cellular LDH released during irradiation. Therefore the use of LDH cytotoxicity based assays with UVB exposure must be considered with extreme care. Keywords: cells, viability, MTS, neutral red, UVB, LDH, cytotoxicity.PublishedN/

Quintessential Kination and Thermal Production of SUSY e-WIMPs

The impact of a kination-dominated phase generated by a quintessential exponential model on the thermal abundance of Supersymmetric (SUSY) extremely Weekly Interacting Massive Particles (e-WIMPs) is investigated. For values of the quintessential energy-density parameter on the eve of nucleosynthesis close to its upper bound, we find that: (i) the gravitino constraint is totally evaded for unstable gravitinos; (ii) the thermal abundance of stable gravitinos is not sufficient to account for the cold dark matter of the universe; (iii) the thermal abundance of axinos can satisfy the cold dark matter constraint for values of the initial (``reheating'') temperature well above those required in the standard cosmology.Comment: To appear in the proceedings of 4th International Workshop On The Dark Side Of The Universe (DSU 2008) 1-5 Jun 2008, Cairo, Egyp

Muon anomalous magnetic moment in supersymmetric scenarios with an intermediate scale and nonuniversality

We analyze the anomalous magnetic moment of the muon (a_{\mu}) in supersymmetric scenarios. First we concentrate on scenarios with universal soft terms. We find that a moderate increase of a_{\mu} can be obtained by lowering the unification scale M_{GUT} to intermediate values 10^{10-12} GeV. However, large values of \tan \beta are still favored. Then we study the case of non-universal soft terms. For the usual value M_{GUT}~10^{16} GeV, we obtain a_{\mu} in the favored experimental range even for moderate \tan \beta regions \tan\beta ~ 5$. Finally, we give an explicit example of these scenarios. In particular, we show that in a D-brane model, where the string scale is naturally of order 10^{10-12} GeV and the soft terms are non universal, a_{\mu} is enhanced with low \tan\beta.Comment: Final version to appear in Phys. Rev. D. Conventions clarified, results in the figures improve

Management of Hypertension in the Obese Pregnant Patient.

PURPOSE OF REVIEW: To evaluate recent developments in the management of hypertension in obese pregnant women. RECENT FINDINGS: The mainstay of management targets prevention of hypertension with preconception counselling, entering pregnancy with a lower BMI, limiting weight gain, and taking low-dose aspirin to prevent pre-eclampsia from before 16 weeks' gestation. There are conflicting results regarding the use of metformin in reducing hypertensive disease, but there is a high probability that it has a role to play. Clinical trials are in progress examining the use of statins in preventing pre-eclampsia, with promising results from pre-clinical trials. Home blood pressure monitoring may be helpful in diagnosing and monitoring the control of hypertension. The most protective interventions against hypertensive disease in obese pregnant women are entering pregnancy at a lower BMI, avoiding inter-pregnancy weight gain, and taking low-dose aspirin during pregnancy. Further research is needed around the use of metformin, statins, and home blood pressure monitoring

Relic Neutralino Density in Scenarios with Intermediate Unification Scale

We analyse the relic neutralino density in supersymmetric models with an intermediate unification scale. In particular, we present concrete cosmological scenarios where the reheating temperature is as small as $\cal{O}$ $1 - 1000$ MeV). When this temperature is associated to the decay of moduli fields producing neutralinos, we show that the relic abundance increases considerably with respect to the standard thermal production. Thus the neutralino becomes a good dark matter candidate with 0.1\lsim \Omega h^2 \lsim 0.3, even for regions of the parameter space where large neutralino-nucleon cross sections, compatible with current dark matter experiments, are present. This is obtained for intermediate scales $M_I\sim 10^{11}-10^{14}$ GeV, and moduli masses $m_\phi\sim 100-1000$ GeV. On the other hand, when the above temperature is associated to the decay of an inflaton field, the relic abundance is too small.Comment: Latex, 11 pages, 2 figure