3,244 research outputs found
Implementing universal nonadiabatic holonomic quantum gates with transmons
Geometric phases are well known to be noise-resilient in quantum
evolutions/operations. Holonomic quantum gates provide us with a robust way
towards universal quantum computation, as these quantum gates are actually
induced by nonabelian geometric phases. Here we propose and elaborate how to
efficiently implement universal nonadiabatic holonomic quantum gates on simpler
superconducting circuits, with a single transmon serving as a qubit. In our
proposal, an arbitrary single-qubit holonomic gate can be realized in a
single-loop scenario, by varying the amplitudes and phase difference of two
microwave fields resonantly coupled to a transmon, while nontrivial two-qubit
holonomic gates may be generated with a transmission-line resonator being
simultaneously coupled to the two target transmons in an effective resonant
way. Moreover, our scenario may readily be scaled up to a two-dimensional
lattice configuration, which is able to support large scalable quantum
computation, paving the way for practically implementing universal nonadiabatic
holonomic quantum computation with superconducting circuits.Comment: v3 Appendix added, v4 published version, v5 published version with
correction
Topological triply-degenerate point with double Fermi arcs
Unconventional chiral particles have recently been predicted to appear in
certain three dimensional (3D) crystal structures containing three- or
more-fold linear band degeneracy points (BDPs). These BDPs carry topological
charges, but are distinct from the standard twofold Weyl points or fourfold
Dirac points, and cannot be described in terms of an emergent relativistic
field theory. Here, we report on the experimental observation of a topological
threefold BDP in a 3D phononic crystal. Using direct acoustic field mapping, we
demonstrate the existence of the threefold BDP in the bulk bandstructure, as
well as doubled Fermi arcs of surface states consistent with a topological
charge of 2. Another novel BDP, similar to a Dirac point but carrying nonzero
topological charge, is connected to the threefold BDP via the doubled Fermi
arcs. These findings pave the way to using these unconventional particles for
exploring new emergent physical phenomena
Effects of temperature on a Chinese population of Amblyseius andersoni (Acari: Phytoseiidae) fed with Tetranychus urticae
International audienceThe development and fecundity of Amblyseius andersoni (Chant) fed with Tetranychus urticae Koch was studied at five different temperatures (17, 20, 25, 30 and 35 Ā°C) and life parameters of the population were calculated. The development, reproduction, longevity, and life table parameters of A. andersoni were significantly affected by the different temperatures. The duration of the egg, larval, protonymph, deutonymph and total immature stages were reduced when the temperature increased. The total oviposition of A. andersoni was highest at 25 Ā°C and lowest at 35 Ā°C, and the daily average oviposition increased as the temperature increased, but few eggs were laid at 17 Ā°C. The values of the intrinsic rate of increase (rm, 0.108--0.200), net reproduction rate (R0, 18.71--36.47) and the mean generation time (T, 14.68--29.73) significantly differed among the five temperatures. The highest net reproduction rate (R0 = 36.47) was obtained at 25 Ā°C. The results of this study indicated that A. andersoni has a high inherent potential for the control of the T. urticae at certain temperatures
Tissue Stresses in Stented Coronary Arteries with Different Geometries: Effect of the Relation Between Stent Length and Lesion Length
In-stent restenosis after stent deployment remains an obstruction in the long-term benefits of stenting. This study sought to investigate the influence of the relation between stent length and lesion length on the mechanics of the arterial wall with different geometries, including straight and tapered vessels. Results showed that when the length of the stent was longer than the lesion length, the maximum stress in plaque and vessel increased as the length of stent increased. When the length of the stent was shorter than the lesion length, the vessel stress induced by stent inflation was lower; both ends of the stenosis plaque could not be fully expanded. When the length of the stent was equal to the lesion length, the plaque and vessel stress induced by stent inflation was minimal, and stent foreshortening was minimal. Compared with the straight vessel, the stent implantation in the tapered vessel with the same stent length resulted in greater stress in vessel and plaque, an increased stent recoil, and a decreased stent foreshortening. When the length of the stent is equal to lesion length, it may be the reasonable choice for straight vessels and tapered vessels. Conclusions drawn from this article can help surgeons to choose appropriate stent lengths
Treatment with gelsolin reduces brain inflammation and apoptotic signaling in mice following thermal injury
<p>Abstract</p> <p>Background</p> <p>Burn survivors develop long-term cognitive impairment with increased inflammation and apoptosis in the brain. Gelsolin, an actin-binding protein with capping and severing activities, plays a crucial role in the septic response. We investigated if gelsolin infusion could attenuate neural damage in burned mice.</p> <p>Methods</p> <p>Mice with 15% total body surface area burns were injected intravenously with bovine serum albumin as placebo (2 mg/kg), or with low (2 mg/kg) or high doses (20 mg/kg) of gelsolin. Samples were harvested at 8, 24, 48 and 72 hours postburn. The immune function of splenic T cells was analyzed. Cerebral pathology was examined by hematoxylin/eosin staining, while activated glial cells and infiltrating leukocytes were detected by immunohistochemistry. Cerebral cytokine mRNAs were further assessed by quantitative real-time PCR, while apoptosis was evaluated by caspase-3. Neural damage was determined using enzyme-linked immunosorbent assay of neuron-specific enolase (NSE) and soluble protein-100 (S-100). Finally, cerebral phospho-ERK expression was measured by western blot.</p> <p>Results</p> <p>Gelsolin significantly improved the outcomes of mice following major burns in a dose-dependent manner. The survival rate was improved by high dose gelsolin treatment compared with the placebo group (56.67% vs. 30%). Although there was no significant improvement in outcome in mice receiving low dose gelsolin (30%), survival time was prolonged against the placebo control (43.1 Ā± 4.5 h vs. 35.5 Ā± 5.0 h; P < 0.05). Burn-induced T cell suppression was greatly alleviated by high dose gelsolin treatment. Concurrently, cerebral abnormalities were greatly ameliorated as shown by reduced NSE and S-100 content of brain, decreased cytokine mRNA expressions, suppressed microglial activation, and enhanced infiltration of CD11b+ and CD45+ cells into the brain. Furthermore, the elevated caspase-3 activity seen following burn injury was remarkably reduced by high dose gelsolin treatment along with down-regulation of phospho-ERK expression.</p> <p>Conclusion</p> <p>Exogenous gelsolin infusion improves survival of mice following major burn injury by partially attenuating inflammation and apoptosis in brain, and by enhancing peripheral T lymphocyte function as well. These data suggest a novel and effective strategy to combat excessive neuroinflammation and to preserve cognition in the setting of major burns.</p
Label Mask AutoEncoder(L-MAE): A Pure Transformer Method to Augment Semantic Segmentation Datasets
Semantic segmentation models based on the conventional neural network can
achieve remarkable performance in such tasks, while the dataset is crucial to
the training model process. Significant progress in expanding datasets has been
made in semi-supervised semantic segmentation recently. However, completing the
pixel-level information remains challenging due to possible missing in a label.
Inspired by Mask AutoEncoder, we present a simple yet effective Pixel-Level
completion method, Label Mask AutoEncoder(L-MAE), that fully uses the existing
information in the label to predict results. The proposed model adopts the
fusion strategy that stacks the label and the corresponding image, namely Fuse
Map. Moreover, since some of the image information is lost when masking the
Fuse Map, direct reconstruction may lead to poor performance. Our proposed
Image Patch Supplement algorithm can supplement the missing information, as the
experiment shows, an average of 4.1% mIoU can be improved. The Pascal VOC2012
dataset (224 crop size, 20 classes) and the Cityscape dataset (448 crop size,
19 classes) are used in the comparative experiments. With the Mask Ratio
setting to 50%, in terms of the prediction region, the proposed model achieves
91.0% and 86.4% of mIoU on Pascal VOC 2012 and Cityscape, respectively,
outperforming other current supervised semantic segmentation models. Our code
and models are available at https://github.com/jjrccop/Label-Mask-Auto-Encoder
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