223 research outputs found
Low-energy electronic structure in Y1-xCaxBa2Cu3O7-y comparison of t ime-resolved optical spectroscopy, NMR, neutron and tunneling data
Time-resolved optical measurements give information on the quasiparticle
relaxation dynamics in YBCO, from which the evolution of the gap with doping
and temperature can be systematically deduced. In this paper these optical
charge-channel `pseudogap' data are compared with the `pseudogap' obtained from
the NMR Knight shift Ks, spin polarized neutron scattering (SPNS) and single
particle tunneling measurements. A simple energy level diagram is proposed to
explain the different `gap' magnitudes observed by different spectroscopies in
Y1-xCaxBa2Cu3O7-y, whereby the spin gap Delta_s in NMR and SPNS corresponds to
a triplet local pair state, while Delta_p in the charge excitation spectrum
corresponds to the pair dissociation energy. At optimum doping and in the
overdoped state, an additional T-dependent gap becomes evident, which closes at
T_c, suggesting a cross-over to a more conventional BCS-like superconductivity
scenario.Comment: 9 pages, 4 figures. Presented in HTS99, Miami, January 9
The management of early-stage and metastatic triple-negative breast cancer: A review
Triple negative breast cancer (TNBC) defined as lacking expression of the estrogen receptor, progesterone receptor and HER2, comprises approximately 15% of incident breast cancers and is over-represented among those with metastatic disease. It is increasingly clear that TNBC is heterogeneous and that there are several biologically distinct subtypes within TNBC, in particular the basal-like subtype but also the claudin-low, among others. While the incidence of BRCA mutations across all subsets of breast cancer is quite low (~5%), BRCA mutations are more common among those with TNBC (~20%) and may have therapeutic implications. The general principles guiding the use of chemotherapy and radiation therapy do not differ dramatically between early stage TNBC and non-TNBC. There is a trend, however, to treat TNBC at a lower stage with chemotherapy as this is the only way to systemically reduce recurrence risk. In the metastatic setting, while cytotoxic chemotherapy is the mainstay of treatment for advanced TNBC, there are many promising targeted therapies in development in both the preclinical and early phase clinical trial settings. While the treatment of TNBC remains a challenge, coordinated efforts between clinician/scientist partnerships providing a comprehensive understanding of TNBC genomic, proteomic and other biologic processes may result in individualized therapy for TNBC faster than other subtypes -- driven by both the heterogeneity we know exists within this clinical entity and the intense need for improved treatment
Wrinkling of foils
Aluminum and copper metal webs less than 150 microns (6-mils) are considered foils. Demand for aluminum and copper foils are growing, driven by growing markets for flexible electronics, flat panel displays, lithium batteries, and solar products. In many of these products, thinner foils have cost or weight advantages, but as with nearly any web, thinner means an increased sensitivity to wrinkling in web handling processes.Nearly all of published web handling research and development work have been based on polymer films and paper webs. Since the web wrinkling theories are based on first principles, they should apply to the foil webs. However, applying models confirmed with paper or foil on narrow widths (less than 0.3m or 12-in wide) to the uncharted territories of foils with 20x elastic modulus and 4x width increases will likely lead to interesting discoveries.This paper will present a comparison of empirical wrinkling results from trials of handling thin and wide aluminum and copper foils (less 25 micron thick by greater than 0.6m wide (less than 0.001-in thick by 24-in. wide). The experimental results will be compared to wrinkling theory, with conclusion about how wrinkling in foils differs from film and paper webs
Multidisciplinary Management of Breast Cancer During Pregnancy
Although breast cancer during pregnancy (BCDP) is rare (occurring with only 0.4% of all BC diagnoses in female patients aged 16–49 years), management decisions are challenging to both the patient and the multidisciplinary team
A Study of the Day - Night Effect for the Super - Kamiokande Detector: I. Time Averaged Solar Neutrino Survival Probability
This is the first of two articles aimed at providing comprehensive
predictions for the day-night (D-N) effect for the Super-Kamiokande detector in
the case of the MSW \nu_e \to \numt transition solution of the solar neutrino
problem. The one-year averaged probability of survival of the solar \nue
crossing the Earth mantle, the core, the inner 2/3 of the core, and the (core +
mantle) is calculated with high precision (better than 1%) using the elliptical
orbit approximation (EOA) to describe the Earth motion around the Sun. Results
for the survival probability in the indicated cases are obtained for a large
set of values of the MSW transition parameters and
from the ``conservative'' regions of the MSW solution,
derived by taking into account possible relatively large uncertainties in the
values of the B and Be neutrino fluxes. Our results show that the
one-year averaged D-N asymmetry in the survival probability for
neutrinos crossing the Earth core can be, in the case of , larger than the asymmetry in the probability for (only mantle
crossing + core crossing) neutrinos by a factor of up to six. The enhancement
is larger in the case of neutrinos crossing the inner 2/3 of the core. This
indicates that the Super-Kamiokande experiment might be able to test the
region of the MSW solution of the solar neutrino
problem by performing selective D-N asymmetry measurements.Comment: LaTeX2e - 18 Text Pages + 21 figures = 39 Pages. - Figures in PS +
text file sk1b14.tex requires two auxiliary files (included
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Treating sample covariances for use in strongly coupled atmosphere-ocean data assimilation
Strongly coupled data assimilation requires cross-domain forecast error covariances; information from ensembles can be used, but limited sampling means that ensemble derived error covariances are routinely rank deficient and/or ill-conditioned and marred by noise. Thus they require modification before they can be incorporated into a standard assimilation framework. Here, we compare methods for improving the rank and conditioning of multivariate sample error covariance matrices for coupled atmosphere-ocean data assimilation. The first method, reconditioning, alters the matrix eigenvalues directly; this preserves the correlation structures but does not remove sampling noise. We show it is better to recondition the correlation matrix rather than the covariance matrix as this prevents small but dynamically important modes from being lost. The second method, model state-space localisation via the Schur product, effectively removes sample noise but can dampen small cross-correlation signals. A combination that exploits the merits of each is found to offer an effective alternative
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