251 research outputs found
Magnetization Plateaus in the Spin-1/2 Kagome Antiferromagnets: Volborthite and Vesignieite
The magnetization of two spin-1/2 kagome antiferromagnets, volborthite and
vesignieite, has been measured in pulsed magnetic fields up to 68 T. A
magnetization plateau is observed for each compound near the highest magnetic
field. Magnetizations at saturation are approximately equal to 0.40Ms for both
compounds, where Ms is the fully saturated magnetization, irrespective of a
difference in the distortion of the kagome lattice between the two compounds.
It should be noted that these values of magnetizations are significantly larger
than Ms/3 predicted theoretically for the one-third magnetization plateau in
the spin-1/2 kagome antiferromagnet. The excess magnetization over Ms/3 is
nearly equal to the sum of the magnetizations gained at the second and third
magnetization steps in volborthite, suggesting that there is a common origin
for the excess magnetization and the magnetization steps.Comment: 4 pages, 4 figures. Phys. Rev. B, accepte
Entrained sand generates fault plane reflections on a deep-water thrust zone
This work is part of Ph.D. research supported by INPEX CORPORATION at University of Aberdeen. We thank Conrad Childs, Haakon Fossen, and an anonymous reviewer for their reviews and constructive suggestions. We thank Petronas and INPEX CORPORATION for the provision of seismic and well data to the Ph.D. research, and for permission to publish this work. Schlumberger and Midland Valley are thanked for the academic use of Petrel 2016.1 and Move 2017.2 software.Peer reviewedPostprin
Dual-GSE: Resource-efficient Generalized Quantum Subspace Expansion
Quantum error mitigation (QEM) is a class of hardware-efficient error
reduction methods through additional modest quantum operations and classical
postprocessing on measurement outcomes. The generalized quantum subspace
expansion (GSE) has been recently proposed as a unified framework of two
distinct QEM methods: quantum subspace expansion (QSE) and purification-based
QEM. GSE takes over the advantages of these two methods, achieving the
mitigation of both coherent and stochastic errors. However, GSE still requires
multiple copies of quantum states and entangled measurements between the
copies, as required in purification-based QEM. This is a significant drawback
under the current situation of the restricted number and connectivity of
qubits. In this work, we propose a resource-efficient implementation of GSE,
which we name "Dual-GSE", circumventing significant overheads of state copies
by constructing an ansatz of error-mitigated quantum states via dual-state
purification. Remarkably, Dual-GSE can further simulate larger quantum systems
beyond the size of available quantum hardware with a suitable ansatz
construction inspired by those divide-and-conquer methods that forge
entanglement classically. This also contributes to a significant reduction of
the measurement overhead because we only need to measure subsystems' Pauli
operators. The proposed method is demonstrated by numerical simulation of the
eight-qubit transverse field Ising model, showing that our method estimates the
ground state energy in high precision under gate noise with low mitigation
overhead and practical sampling cost.Comment: 25 pages, 19 figure
Thermal Control System to Easily Cool the GAPS Balloon-borne Instrument on the Ground
This study developed a novel thermal control system to cool detectors of the
General AntiParticle Spectrometer (GAPS) before its flights. GAPS is a
balloon-borne cosmic-ray observation experiment. In its payload, GAPS contains
over 1000 silicon detectors that must be cooled below -40^{\circ}\mbox{C}.
All detectors are thermally coupled to a unique heat-pipe system (HPS) that
transfers heat from the detectors to a radiator. The radiator is designed to be
cooled below -50^{\circ}\mbox{C} during the flight by exposure to space. The
pre-flight state of the detectors is checked on the ground at 1 atm and ambient
room temperature, but the radiator cannot be similarly cooled. The authors have
developed a ground cooling system (GCS) to chill the detectors for ground
testing. The GCS consists of a cold plate, a chiller, and insulating foam. The
cold plate is designed to be attached to the radiator and cooled by a coolant
pumped by the chiller. The payload configuration, including the HPS, can be the
same as that of the flight. The GCS design was validated by thermal tests using
a scale model. The GCS design is simple and provides a practical guideline,
including a simple estimation of appropriate thermal insulation thickness,
which can be easily adapted to other applications.Comment: 8 pages, 14 figures, 3 table
Visualization of spatiotemporal activation of Notch signaling: Live monitoring and significance in neural development
AbstractNotch signaling plays various key roles in cell fate determination during CNS development in a context-dependent fashion. However, its precise physiological role and the localization of its target cells remain unclear. To address this issue, we developed a new reporter system for assessing the RBP-J-mediated activation of Notch signaling target genes in living cells and tissues using a fluorescent protein Venus. Our reporter system revealed that Notch signaling is selectively activated in neurosphere-initiating multipotent neural stem cells in vitro and in radial glia in the embryonic forebrain in vivo. Furthermore, the activation of Notch signaling occurs during gliogenesis and is required in the early stage of astroglial development. Consistent with these findings, the persistent activation of Notch signaling inhibits the differentiation of GFAP-positive astrocytes. Thus, the development of our RBP-J-dependent live reporter system, which is activated upon Notch activation, together with a stage-dependent gain-of-function analysis allowed us to gain further insight into the complexity of Notch signaling in mammalian CNS development
Malignant peripheral nerve sheath tumor arising from the greater omentum: Case report
Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue tumors that arise from a peripheral nerve or exhibit nerve sheath differentiation. Most of these tumors arise on the trunk, extremities, or head and neck regions; they are very rarely located in the abdominal cavity. The patient was a 71-year-old man who was referred to our hospital for a mass and pain in the right lower abdomen. Abdominal computed tomography revealed a large (9 × 9 cm), well-circumscribed, lobulated, heterogeneously enhanced mass in the pelvis. Exploratory laparotomy revealed a large mass in the greater omentum, and the tumor was completely excised. Histopathological analysis revealed that the tumor was composed of spindle cells with high mitotic activity. On staining the tumor, positive results were obtained for S-100 but negative results were obtained for c-kit, cluster of differentiation (CD)34, α-smooth muscle actin, and desmin. These findings strongly supported a diagnosis of MPNST primarily arising from the greater omentum. To the best of our knowledge, this is the first reported case of an MPNST arising from the greater omentum. In this report, we have described the case of a patient with an MPNST arising from the greater omentum and have discussed the clinical characteristics and management of MPNSTs
Generation and Characterization of a Host Cell-Dependent gag Gene Mutant of Human Immunodeficiency Virus Type 1
AbstractAn in-frame gag gene mutant of human immunodeficiency virus type 1, which carries two amino acid substitutions in the center of the p24 coding region, was constructed in vitro, and its replication properties in several cell lines were examined. In CD4-negative SW480 cells transfected with the mutant clone, synthesis and processing of viral gag, pol, and env proteins occurred normally, and viral particles were produced. Virions derived from the transfection displayed a severe replication defect when inoculated into some CD4-positive cell lines (H9 and Molt4 clone 8), but in other lines (A3.01 and M8166), the mutant virus grew fairly well. The mutant was demonstrated to be defective at an early infection phase (from adsorption to integration) in Molt4 clone 8 cells but was normal in A3.01 cells. These results indicated that the Gag-p24 protein of human immunodeficiency virus type 1 plays an important role at the early infection phase in a cell-dependent manner
- …