3,337 research outputs found
d-Wave Checkerboard Order in Cuprates
We show that the d-wave ordering in particle-hole channels, dubbed d-wave
checkerboard order, possesses important physics that can sufficiently explain
the scanning tunneling microscopy (STM) results in cuprates. A weak d-wave
checkerboard order can effectively suppress the coherence peak in the
single-particle spectrum while leaving the spectrum along the nodal direction
almost unaffected. Simultaneously, it generates a Fermi arc with little
dispersion around the nodal points at finite temperature that is consistent
with the results of angle-resolved photoemission spectroscopy (ARPES)
experiments in the pseudogap phase. We also show that there is a general
complementary connection between the d-wave checkerboard order and the
pair-density-wave order. Suppressing superconductivity locally or globally
through phase fluctuations should induce both orders in underdoped cuprates and
explain the nodal-antinodal dichotomy observed in ARPES and STM experiments
Complementary Pair Density Wave and d-wave Checkerboard Order in High Temperature Superconductors
The competing orders in the particle-particle (P-P) channel and the
particle-hole (P-H) channel have been proposed separately to explain the
pseudogap physics in cuprates. By solving the Bogoliubov-deGennes equation
self-consistently, we show that there is a general complementary connection
between the d-wave checkerboard order (DWCB) in the particle-hole (P-H) channel
and the pair density wave order (PDW) in the particle-particle (P-P) channel. A
small pair density localization generates DWCB and PDW orders simultaneously.
The result suggests that suppressing superconductivity locally or globally
through phase fluctuation should induce both orders in underdoped cuprates. The
presence of both DWCB and PDW orders with periodicity can
explain the checkerboard modulation observed in FT-STS from STM and the
puzzling dichotomy between the nodal and antinodal regions as well as the
characteristic features such as non-dispersive Fermi arc in the pseudogap
state
Both Basic and Acidic Amino Acid Residues of IpTxa Are Involved in Triggering Substate of RyR1
Imperatoxin A (IpTxa) is known to modify the gating of skeletal ryanodine receptor (RyR1). In this paper, the ability of charged aa residues of IpTxa to induce substate of native RyR1 in HSR was examined. Our results show that the basic residues (e.g., Lys19, Lys20, Lys22, Arg23, and Arg24) are important for producing substate of RyR1. In addition, other basic residues (e.g., Lys30, Arg31, and Arg33) near the C-terminus and some acidic residues (e.g., Glu29, Asp13, and Asp2) are also involved in the generation of substate. Residues such as Lys8 and Thr26 may be involved in the self-regulation of substate of RyR1, since alanine substitution of the aa residues led to a drastic conversion to the substate. The modifications of the channel gating by the wild-type and mutant toxins were similar in purified RyR1. Taken together, the specific charge distributions on the surface of IpTxa are essential for regulation of the channel gating of RyR1
Chiral magnetoresistance in Pt/Co/Pt zigzag wires
The Rashba effect leads to a chiral precession of the spins of moving
electrons while the Dzyaloshinskii-Moriya interaction (DMI) generates
preference towards a chiral profile of local spins. We predict that the
exchange interaction between these two spin systems results in a 'chiral'
magnetoresistance depending on the chirality of the local spin texture. We
observe this magnetoresistance by measuring the domain wall (DW) resistance in
a uniquely designed Pt/Co/Pt zigzag wire, and by changing the chirality of the
DW with applying an in-plane magnetic field. A chirality-dependent DW
resistance is found, and a quantitative analysis shows a good agreement with a
theory based on the Rashba model. Moreover, the DW resistance measurement
allows us to independently determine the strength of the Rashba effect and the
DMI simultaneously, and the result implies a possible correlation between the
Rashba effect, the DMI, and the symmetric Heisenberg exchange
TinyECCK: Efficient Elliptic Curve Cryptography Implementation over on 8-bit MICAz Mote
In this paper, we revisit a generally accepted opinion:
implementing Elliptic Curve Cryptosystem (ECC) over on
sensor motes using small word size is not appropriate because XOR
multiplication over is not efficiently supported by
current low-powered microprocessors. Although there are some
implementations over on sensor motes, their performances
are not satisfactory enough to be used for wireless sensor networks (WSNs).
We have found that a field multiplication over are involved
in a number of redundant memory accesses and its inefficiency
is originated from this problem. Moreover, the field reduction process
also requires many redundant memory accesses.
Therefore, we propose some techniques for reducing unnecessary
memory accesses. With the proposed strategies, the
running time of field multiplication and reduction over
can be decreased by 21.1\% and 24.7\%, respectively.
These savings noticeably decrease execution times spent in
Elliptic Curve Digital Signature Algorithm (ECDSA) operations
(signing and verification) by around . We present
TinyECCK (Tiny Elliptic Curve Cryptosystem with Koblitz curve -- a
kind of TinyOS package supporting elliptic curve operations) which
is the fastest ECC implementation over on 8-bit sensor motes
using ATmega128L as far as we know. Through comparisons with existing software
implementations of ECC built in C or hybrid of C and inline
assembly on sensor motes, we show that TinyECCK outperforms
them in terms of running time, code size and supporting services.
Furthermore, we show that a field multiplication over
can be faster than that over on 8-bit ATmega128L processor
by comparing TinyECCK with TinyECC, a well-known ECC implementation
over . TinyECCK with sect163k1 can compute a scalar multiplication
within 1.14 secs on a MICAz mote at the expense of 5,592-byte of ROM and
618-byte of RAM. Furthermore, it can also generate a signature and verify
it in 1.37 and 2.32 secs with 13,748-byte of ROM and 1,004-byte of RAM
High correlation of Middle East respiratory syndrome spread with Google search and Twitter trends in Korea
The Middle East respiratory syndrome coronavirus (MERS-CoV) was exported to Korea in 2015, resulting in a threat to neighboring nations. We evaluated the possibility of using a digital surveillance system based on web searches and social media data to monitor this MERS outbreak. We collected the number of daily laboratory-confirmed MERS cases and quarantined cases from May 11, 2015 to June 26, 2015 using the Korean government MERS portal. The daily trends observed via Google search and Twitter during the same time period were also ascertained using Google Trends and Topsy. Correlations among the data were then examined using Spearman correlation analysis. We found high correlations (>0.7) between Google search and Twitter results and the number of confirmed MERS cases for the previous three days using only four simple keywords: “MERS”, “[Image: see text]” (“MERS (in Korean)”), “[Image: see text]” (“MERS symptoms (in Korean)”), and “[Image: see text]” (“MERS hospital (in Korean)”). Additionally, we found high correlations between the Google search and Twitter results and the number of quarantined cases using the above keywords. This study demonstrates the possibility of using a digital surveillance system to monitor the outbreak of MERS
A situation-aware cross-platform architecture for ubiquitous game
Multi-player online games (MOGs) are popular in these days. However, contemporary MOGs do not really support ubiquity in the sense that a seamless service across heterogeneous hardware platforms is not provided. This paper presents the architecture of the cross-platform online game, which provides a service to users from heterogeneous platforms and is equipped with a situation-aware capability for enabling the users to seamlessly move between heterogeneous platforms. The experimental results through the prototype implementations show the feasibility of the situation-aware cross-platform game
Does Bicycle Riding Impact the Development of Lower Urinary Tract Symptoms and Sexual Dysfunction in Men?
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