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Ibuprofen During the COVID-19 Pandemic: Social Media Precautions and Implications
Experimentally Feasible Security Check for n-qubit Quantum Secret Sharing
In this article we present a general security strategy for quantum secret
sharing (QSS) protocols based on the HBB scheme presented by Hillery, Bu\v{z}ek
and Berthiaume [Phys. Rev A \textbf{59}, 1829 (1999)]. We focus on a
generalization of the HBB protocol to communication parties thus including
-partite GHZ states. We show that the multipartite version of the HBB scheme
is insecure in certain settings and impractical when going to large . To
provide security for such QSS schemes in general we use the framework presented
by some of the authors [M. Huber, F. Minert, A. Gabriel, B. C. Hiesmayr, Phys.
Rev. Lett. \textbf{104}, 210501 (2010)] to detect certain genuine partite
entanglement between the communication parties. In particular, we present a
simple inequality which tests the security.Comment: 5 pages, submitted to Phys. Rev.
The halt of deep convection in the Greenland Sea: A natural experiment for the study of their causes and effects
There are only a few sites where the deep ocean is ventilated from the surface. The responsible process known as
deep convection is recognized to be a key process on the Earth’s climate system, but still it is scarcely observed, and
its good representation by global oceanographic and climate models remains unclear. In the Arctic Ocean, the halt
of deep convection in the Greenland Sea during the last three decades serves as a natural experiment to study: (1)
the conditions that drive the occurrence or not of deep convection and (2) the effects of the halt of deep convection
on the thermohaline properties of the deep water masses and circulation both locally and in adjacent ocean basins.
Combining oceanic and atmospheric in-situ data together with reanalysis data, we observe that not only on average
the winter net heat losses from the ocean to the atmosphere (Qo) have decreased during the last three decades in the
Greenland Sea ( Qo (before the 1980s- after the 1980s) = 25 Wm-2) but the intensity and number of strong cooling
events (Qo 800Wm-2). This last value for convection reaching 2000 m in the Greenland Sea seems critical to
make the mixed layer deepening from being a non-penetrative process to one arrested by baroclinic instabilities.
Besides, changes in the wind stress curl and preconditioning for deep convection have occurred, hindering also the
occurrence of deep convection. Concerning the effects of the halt of deep convection, hydrographic data reveal that
the temperature between 2000 meters depth and the sea floor has risen by 0.3 C in the last 30 years, which is ten
times higher than the temperature increase in the global ocean on average, and salinity rose by 0.02 because import
of relatively warm and salty Arctic Ocean deep waters continued. The necessary transports to explain the observed
changes suggest an increase of Arctic Ocean deep water transport that would have compensated the decrease in
deep water formation rate after the 1980s. The effects of these changes in adjacent basins remain unstudied, but
the bottom waters seem to be upwelled towards the slope and the Jan Mayen ridge, being an exit for the Greenland
Sea deep waters.0,000
A Comprehensive Analysis Of The Efficacy Of Non-Cognitive Measures: Predicting Academic Success In A Historically Black University In South Texas
Universities have long used standardized American College Tests (ACT), Scholastic Aptitude Tests (SAT), and high school Grade Point Averages (HS GPA) for academic admission requirements. The current study of 127 minority college students in a Historically Black University in South Texas assesses an alternative measure, the Non-Cognitive Questionnaire developed by William Sedlacek. It is also important to test the validity of these standards for graduation success. As part of the process for residence hall placement at the Historically Black University, each participant completed a Non-Cognitive Questionnaire (NCQ) (Schauer, 2007). Preliminary indications provide neither a clear cut distinction nor a strong probability of success based on ACT or SAT scores among minority college students. High school GPA appears to be the best predictor of college graduation success among academic admission requirements in a Historically Black University. The NCQ appears to be a weak predictive tool in the success rates of minority students in the current study. Further study is required in the child developmental years of educational training
Ischemic preconditioning attenuates portal venous plasma concentrations of purines following warm liver ischemia in man
Background/Aims: Degradation of adenine nucleotides to adenosine has been suggested to play a critical role in ischemic preconditioning (IPC). Thus, we questioned in patients undergoing partial hepatectomy whether (i) IPC will increase plasma purine catabolites and whether (ii) formation of purines in response to vascular clamping (Pringle maneuver) can be attenuated by prior IPC. Methods: 75 patients were randomly assigned to three groups: group I underwent hepatectomy without vascular clamping; group II was subjected to the Pringle maneuver during resection, and group III was preconditioned (10 min ischemia and 10 min reperfusion) prior to the Pringle maneuver for resection. Central, portal venous and arterial plasma concentrations of adenosine, inosine, hypoxanthine and xanthine were determined by high-performance liquid chromatography. Results: Duration of the Pringle maneuver did not differ between patients with or without IPC. Surgery without vascular clamping had only a minor effect on plasma purine transiently increased. After the Pringle maneuver alone, purine plasma concentrations were most increased. This strong rise in plasma purines caused by the Pringle maneuver, however, was significantly attenuated by IPC. When portal venous minus arterial concentration difference was calculated for inosine or hypoxanthine, the respective differences became positive in patients subjected to the Pringle maneuver and were completely prevented by preconditioning. Conclusion: These data demonstrate that (i) IPC increases formation of adenosine, and that (ii) the unwanted degradation of adenine nucleotides to purines caused by the Pringle maneuver can be attenuated by IPC. Because IPC also induces a decrease of portal venous minus arterial purine plasma concentration differences, IPC might possibly decrease disturbances in the energy metabolism in the intestine as well. Copyright (C) 2005 S. Karger AG, Basel
Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter
The Thorium-229 isotope features a nuclear isomer state with an extremely low
energy. The currently most accepted energy value, 7.8 +- 0.5 eV, was obtained
from an indirect measurement using a NASA x-ray microcalorimeter with an
instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic
microcalorimeters with an energy resolution down to a few eV can be used to
measure the isomer energy. In particular, resolving the 29.18 keV doublet in
the \gamma-spectrum following the \alpha-decay of Uranium-233, corresponding to
the decay into the ground and isomer state, allows to measure the isomer
transition energy without additional theoretical input parameters, and increase
the energy accuracy. We study the possibility of resolving the 29.18 keV line
as a doublet and the dependence of the attainable precision of the energy
measurement on the signal and background count rates and the instrumental
resolution.Comment: 32 pages, 8 figures, eq. (3) correcte
Neither dust nor black carbon causing apparent albedo decline in Greenland\u27s dry snow zone: Implications for MODIS C5 surface reflectance
Remote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light-absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving melt events. Analysis of Collection 5 Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data indicates that the decline and spectral shift in dry snow albedo contains important contributions from uncorrected Terra sensor degradation. Though discrepancies are mostly below the stated accuracy of MODIS products, they will require revisiting some prior conclusions with C6 data
The Los Alamos Trapped Ion Quantum Computer Experiment
The development and theory of an experiment to investigate quantum
computation with trapped calcium ions is described. The ion trap, laser and ion
requirements are determined, and the parameters required for quantum logic
operations as well as simple quantum factoring are described.Comment: 41 pages, 16 figures, submitted to Fortschritte der Physi
Quantum Cryptography
Quantum cryptography is a new method for secret communications offering the
ultimate security assurance of the inviolability of a Law of Nature. In this
paper we shall describe the theory of quantum cryptography, its potential
relevance and the development of a prototype system at Los Alamos, which
utilises the phenomenon of single-photon interference to perform quantum
cryptography over an optical fiber communications link.Comment: 36 pages in compressed PostScript format, 10 PostScript figures
compressed tar fil
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