1,793 research outputs found
Bishop-Phelps-Bolloba's theorem on bounded closed convex sets
This paper deals with the \emph{Bishop-Phelps-Bollob\'as property}
(\emph{BPBp} for short) on bounded closed convex subsets of a Banach space ,
not just on its closed unit ball . We firstly prove that the \emph{BPBp}
holds for bounded linear functionals on arbitrary bounded closed convex subsets
of a real Banach space. We show that for all finite dimensional Banach spaces
and the pair has the \emph{BPBp} on every bounded closed convex
subset of , and also that for a Banach space with property
the pair has the \emph{BPBp} on every bounded closed absolutely convex
subset of an arbitrary Banach space . For a bounded closed absorbing
convex subset of with positive modulus convexity we get that the pair
has the \emph{BPBp} on for every Banach space . We further
obtain that for an Asplund space and for a locally compact Hausdorff ,
the pair has the \emph{BPBp} on every bounded closed absolutely
convex subset of . Finally we study the stability of the \emph{BPBp} on
a bounded closed convex set for the -sum or -sum of a
family of Banach spaces
Charge density wave surface reconstruction in a van der Waals layered material
Surface reconstruction plays a vital role in determining the surface
electronic structure and chemistry of semiconductors and metal oxides. However,
it has been commonly believed that surface reconstruction does not occur in van
der Waals layered materials, as they do not undergo significant bond breaking
during surface formation. In this study, we present evidence that charge
density wave (CDW) order in these materials can, in fact, cause CDW surface
reconstruction through interlayer coupling. Using density functional theory
calculations on the 1T-TaS2 surface, we reveal that CDW reconstruction,
involving concerted small atomic displacements in the subsurface layer, results
in a significant modification of the surface electronic structure, transforming
it from a Mott insulator to a band insulator. This new form of surface
reconstruction explains several previously unexplained observations on the
1T-TaS2 surface and has important implications for interpreting surface
phenomena in CDW-ordered layered materials.Comment: 20 pages, 6 figures (Supplementary Information: 5 Pages, 3 figures
Hedge fund market runs during financial crises
Hedge funds exit financial markets simultaneously after enormous
shocks, such as the global financial crisis. While previous studies
highlight only fund investorsā synchronized withdrawals as the
major driver of massive asset liquidations, we primarily focus on
informed and rational fund managers and suggest a theoretical
model that illustrates fund managersā synchronized market runs.
This study shows that the possibility of runs induces panic-based
market runs not because of systematic risk itself but because of
the fear of runs. We find that when the market regime changes
from a normal to a ābadā state in which runs are possible, hedge
funds reduce their investments prior to runs. In addition, market
runs are more likely to occur in markets in which hedge funds
have greater market exposure and uninformed traders are more
sensitive to past price movement
Complementing T Cellsā Functions: Bringing in Metabolism Matters
Components of the complement system act directly on TĀ cells to alter conventional and regulatory TĀ cell subsets. In this issue of Immunity, Kolev, Dimeloe, Le Friec etĀ al. (2015) provide evidence of a mechanism by which the complement stimulates sustained mTORC1 activation and regulates cellular metabolism
Correlated electronic states at domain walls of a Mott-charge-density-wave insulator 1T-TaS2
Domain walls in interacting electronic systems can have distinct localized
states, which often govern physical properties and may lead to unprecedented
functionalities and novel devices. However, electronic states within domain
walls themselves have not been clearly identified and understood for strongly
correlated electron systems. Here, we resolve the electronic states localized
on domain walls in a Mott-charge-density-wave(CDW) insulator 1T-TaS2 using
scanning tunneling spectroscopy. We establish that the domain wall state
decomposes into two nonconducting states located at the center of domain walls
and edges of domains. Theoretical calculations reveal their atomistic origin as
the local reconstruction of domain walls under the strong influence of electron
correlation. Our results introduce a concept for the domain wall electronic
property, the wall's own internal degrees of freedom, which is potentially
related to the controllability of domain wall electronic properties
The efficacy of preoperative PET/CT for prediction of curability in surgery for locally advanced gastric carcinoma
<p>Abstract</p> <p>Background</p> <p>The benefits of preoperative <sup>18</sup>FDG-PET/CT for gastric cancer remain uncertain. The aim of this study was to investigate the effects of preoperative <sup>18</sup>FDG-PET/CT on the surgical strategy for locally advanced gastric cancer retrospectively.</p> <p>Methods</p> <p>From January 2007 to November 2008, <sup>18</sup>FDG-PET/CT was performed in 142 patients who had been diagnosed with advanced gastric cancer by computed tomography or gastrofiberscope findings.</p> <p>Results</p> <p>Detection rates were 88.7% (126/142) for primary tumors and 24.6% (35/142) for local lymph nodes (LN). Nine patients with metastatic lesions underwent induction chemotherapy without operation. Of 133 patients subjected to operation, positive FDG uptake in primary tumors (<it>p </it>= 0.047) and local lymph nodes (<it>p </it>< 0.001) was related to non-curable operations. The mean standard uptake value (SUV) of primary tumors of patients who underwent non-curable operations was significantly higher than that of patients with curable operations (<it>p </it>= 0.001). When the SUV was greater than 5 and FDG uptake of LN was positive, non-curable operations were predicted with a sensitivity of 35.2%, a specificity of 91.0% and an accuracy of 76.7%.</p> <p>Conclusions</p> <p>High SUV of the primary tumor and positive FDG uptake in local lymph nodes at PET/CT could predict non-curative resection in locally advanced gastric cancer. Therefore, information from preoperative PET/CT can help physician decisions regarding other modalities without laparotomy.</p
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