2,242 research outputs found
The effect of strain and filament fracture on the transport properties of ITER cable-in-conduit conductors
Commentary on rainbow-ladder truncation for excited states and exotics
Ground-state, radially-excited and exotic scalar-, vector- and
flavoured-pseudoscalar-mesons are studied in rainbow-ladder truncation using an
interaction kernel that is consonant with modern DSE- and lattice-QCD results.
The inability of this truncation to provide realistic predictions for the
masses of excited- and exotic-states is confirmed and explained. On the other
hand, its application does provide information that is potentially useful in
proceeding beyond this leading-order truncation, e.g.: assisting with
development of projection techniques that ease the computation of excited state
properties; placing qualitative constraints on the long-range behaviour of the
interaction kernel; and highlighting and illustrating some features of hadron
observables that do not depend on details of the dynamics.Comment: 10 pages, 6 figures, 2 table
The role of sediment-induced light attenuation on primary production during Hurricane Gustav (2008)
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zang, Z., Xue, Z. G., Xu, K., Bentley, S. J., Chen, Q., D'Sa, E. J., Zhang, L., & Ou, Y. The role of sediment-induced light attenuation on primary production during Hurricane Gustav (2008). Biogeosciences, 17(20), (2020): 5043-5055, doi:10.5194/bg-17-5043-2020.We introduced a sediment-induced light attenuation algorithm into a biogeochemical model of the Coupled OceanâAtmosphereâWaveâSediment Transport (COAWST) modeling system. A fully coupled oceanâatmosphericâsedimentâbiogeochemical simulation was carried out to assess the impact of sediment-induced light attenuation on primary production in the northern Gulf of Mexico during the passage of Hurricane Gustav in 2008. When compared with model results without sediment-induced light attenuation, our new model showed a better agreement with satellite data on both the magnitude of nearshore chlorophyll concentration and the spatial distribution of offshore bloom. When Hurricane Gustav approached, resuspended sediment shifted the inner shelf ecosystem from a nutrient-limited one to a light-limited one. Only 1 week after Hurricane Gustav's landfall, accumulated nutrients and a favorable optical environment induced a posthurricane algal bloom in the top 20âm of the water column, while the productivity in the lower water column was still light-limited due to slow-settling sediment. Corresponding with the elevated offshore NO3 flux (38.71âmmolâNâmâ1âsâ1) and decreased chlorophyll flux (43.10âmgâmâ1âsâ1), the outer shelf posthurricane bloom should have resulted from the cross-shelf nutrient supply instead of the lateral dispersed chlorophyll. Sensitivity tests indicated that sediment light attenuation efficiency affected primary production when sediment concentration was moderately high. Model uncertainties due to colored dissolved organic matter and parameterization of sediment-induced light attenuation are also discussed.This research has been supported by the National Science Foundation (grant nos. CCF-1856359, EnvS-1903340, OCE-1635837 and EAR-1427389), NASA (grant no. NNH17ZHA002C), the Louisiana Board of Regents (grant no. NASA/LEQSF(2018-20)-Phase3-11) and the LSU Foundation Billy and Ann Harrison Endowment for Sedimentary Geology
A numerical investigation of wave-supported gravity flow during cold fronts over the Atchafalaya Shelf
Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125(9), (2020): e2019JC015269, doi:10.1029/2019JC015269Waveâsupported fluid mud (WSFM) plays an important role in sediment downslope transport on the continental shelves. In this study, we incorporated WSFM processes in the wave boundary layer (WBL) into the Community Sediment Transport Modeling System (CSTMS) on the platform of the Coupled OceanâAtmosphereâWaveâandâSediment Transport modeling system (COAWST). The WSFM module was introduced between the bottommost water layer and top sediment layer, which accounted for the key sediment exchange processes (e.g., resuspension, vertical settling, diffusion, and horizontal advection) at the waterâWBL and WBLâsediment bed boundaries. To test its robustness, we adapted the updated model (CSTMS + WBL) to the Atchafalaya shelf in the northern Gulf of Mexico and successfully reproduced the sediment dynamics in March 2008, when active WSFM processes were reported. Compared with original CSTMS results, including WSFM module weakened the overall intensity of sediment resuspension, and the CSTMS + WBL model simulated a lutocline between the WBL and overlying water due to the formation of WSFM. Downslope WSFM transport resulted in offshore deposition (>4 cm), which greatly changed the net erosion/deposition pattern on the inner shelf off the Chenier Plain. WSFM flux was comparable with suspended sediment flux (SSF) off the Atchafalaya Bay, and it peaked along the Chenier Plain coast where wave activities were strong and the bathymetric slope was steep. The influence of fluvial sediment supply on sediment dynamics was limited in the Atchafalaya Bay. Sensitivity tests of free settling, flocculation, and hindered settling effects suggested that sediments were transported further offshore due to reduced settling velocity in the WBL once fluid mud was formed. Although sediment concentration in the WBL was sensitive to surface sediment critical shear stress, cohesive bed behavior was less important in WSFM dynamics when compared with strong hydrodynamic during cold fronts.Research support provided through NSF CyberSEES (Award CCFâ1856359), NASA (Award NNH17ZHA002C), Louisiana Board of Regents (award number NASA/LEQSF(2018â20)âPhase3â11), Bureau of Ocean Energy Management (Cooperative Agreement Award M20AC00007), NSF Coastal SEES (Award EARâ1427389 ), NSF (Award OCEâ20203676), and LSU Foundation Billy and Ann Harrison Endowment for Sedimentary Geology.2021-02-1
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Arylbenzazepines Are Potent Modulators for the Delayed Rectifier K+ Channel: A Potential Mechanism for Their Neuroprotective Effects
(±) SKF83959, like many other arylbenzazepines, elicits powerful neuroprotection in vitro and in vivo. The neuroprotective action of the compound was found to partially depend on its D1-like dopamine receptor agonistic activity. The precise mechanism for the (±) SKF83959-mediated neuroprotection remains elusive. We report here that (±) SKF83959 is a potent blocker for delayed rectifier K+ channel. (±) SKF83959 inhibited the delayed rectifier K+ current (IK) dose-dependently in rat hippocampal neurons. The IC50 value for inhibition of IK was 41.9±2.3 ”M (Hill coefficientâ=â1.81±0.13, nâ=â6), whereas that for inhibition of IA was 307.9±38.5 ”M (Hill coefficientâ=â1.37±0.08, nâ=â6). Thus, (±) SKF83959 is 7.3-fold more potent in suppressing IK than IA. Moreover, the inhibition of IK by (±) SKF83959 was voltage-dependent and not related to dopamine receptors. The rapidly onset of inhibition and recovery suggests that the inhibition resulted from a direct interaction of (±) SKF83959 with the K+ channel. The intracellular application of (±) SKF83959 had no effects of on IK, indicating that the compound most likely acts at the outer mouth of the pore of K+ channel. We also tested the enantiomers of (±) SKF83959, R-(+) SKF83959 (MCL-201), and S-(â) SKF83959 (MCL-202), as well as SKF38393; all these compounds inhibited IK. However, (±) SKF83959, at either 0.1 or 1 mM, exhibited the strongest inhibition on the currents among all tested drug. The present findings not only revealed a new potent blocker of IK , but also provided a novel mechanism for the neuroprotective action of arylbenzazepines such as (±) SKF83959
Interaction model for the gap equation
We explain a form for the rainbow-ladder kernel whose momentum-dependence is
consonant with modern DSE- and lattice-QCD results, and assess its capability
as a tool in hadron physics. In every respect tested, this form produces
results for observables that are at least equal to the best otherwise obtained
in a comparable approach. Moreover, it enables the natural extraction of a
monotonic running-coupling and -gluon-mass.Comment: 5 pages, 1 figure, 2 table
Colposcopic accuracy in diagnosing squamous intraepithelial lesions: a systematic review and meta-analysis of the International Federation of Cervical Pathology and Colposcopy 2011 terminology
Background Colposcopy is an important tool in diagnosing cervical cancer, and the International Federation of Cervical Pathology and Colposcopy (IFCPC) issued the latest version of the guidelines in 2011. This study aims to systematically assess the accuracy of colposcopy in predicting low-grade squamous intraepithelial lesions or worse (LSIL+) / high-grade squamous intraepithelial lesions or worse (HSIL+) under the 2011 IFCPC terminology. Methods We performed a systematic review and meta-analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched for studies about the performance of colposcopy in diagnosing cervical intraepithelial neoplasia under the new IFCPC colposcopy terminology from PubMed, Embase, Web of Science and the Cochrane database. Data were independently extracted by two authors and an overall diagnostic performance index was calculated under two colposcopic thresholds. Results In total, fifteen articles with 22,764 participants in compliance with the criteria were included in meta-analysis. When colposcopy was used to detect LSIL+, the combined sensitivity and specifcity were 0.92 (95% CI 0.88â0.95) and 0.51 (0.43â0.59), respectively. When colposcopy was used to detect HSIL+, the combined sensitivity and specifcity were 0.68 (0.58â0.76) and 0.93 (0.88â0.96), respectively. Conclusion In accordance with the 2011 IFCPC terminology, the accuracy of colposcopy has improved in terms of both sensitivity and specifcity. Colposcopy is now more sensitive with LSIL+ taken as the cut-of value and is more specifc to HSIL+. These fndings suggest we are avoiding under- or overdiagnosis both of which impact on patientsâ well-being
Synthesis and Characterization of Glomerate GaN Nanowires
Glomerate GaN nanowires were synthesized on Si(111) substrates by annealing sputtered Ga2O3/Co films under flowing ammonia at temperature of 950 °C. X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy and Fourier transformed infrared spectra were used to characterize the morphology, crystallinity and microstructure of the as-synthesized samples. Our results show that the samples are of hexagonal wurtzite structure. For the majority of GaN nanowires, the length is up to tens of microns and the diameter is in the range of 50â200 nm. The growth process of the GaN nanowires is dominated by CoâGaâN alloy mechanism
ER-mitochondria contacts promote mtDNA nucleoids active transportation via mitochondrial dynamic tubulation.
A human cell contains hundreds to thousands of mitochondrial DNA (mtDNA) packaged into nucleoids. Currently, the segregation and allocation of nucleoids are thought to be passively determined by mitochondrial fusion and division. Here we provide evidence, using live-cell super-resolution imaging, that nucleoids can be actively transported via KIF5B-driven mitochondrial dynamic tubulation (MDT) activities that predominantly occur at the ER-mitochondria contact sites (EMCS). We further demonstrate that a mitochondrial inner membrane protein complex MICOS links nucleoids to Miro1, a KIF5B receptor on mitochondria, at the EMCS. We show that such active transportation is a mechanism essential for the proper distribution of nucleoids in the peripheral zone of the cell. Together, our work identifies an active transportation mechanism of nucleoids, with EMCS serving as a key platform for the interplay of nucleoids, MICOS, Miro1, and KIF5B to coordinate nucleoids segregation and transportation
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LNK suppresses interferon signaling in melanoma.
LNK (SH2B3) is a key negative regulator of JAK-STAT signaling which has been extensively studied in malignant hematopoietic diseases. We found that LNK is significantly elevated in cutaneous melanoma; this elevation is correlated with hyperactive signaling of the RAS-RAF-MEK pathway. Elevated LNK enhances cell growth and survival in adverse conditions. Forced expression of LNK inhibits signaling by interferon-STAT1 and suppresses interferon (IFN) induced cell cycle arrest and cell apoptosis. In contrast, silencing LNK expression by either shRNA or CRISPR-Cas9 potentiates the killing effect of IFN. The IFN-LNK signaling is tightly regulated by a negative feedback mechanism; melanoma cells exposed to IFN upregulate expression of LNK to prevent overactivation of this signaling pathway. Our study reveals an unappreciated function of LNK in melanoma and highlights the critical role of the IFN-STAT1-LNK signaling axis in this potentially devastating disease. LNK may be further explored as a potential therapeutic target for melanoma immunotherapy
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