214 research outputs found
Orientation-dependent adhesion strength of a rigid cylinder in non-slipping contact with a transversely isotropic half-space
Recently, Chen and Gao [Chen, S., Gao, H., 2007. Bio-inspired mechanics of reversible adhesion: orientation-dependent adhesion strength for non-slipping adhesive contact with transversely isotropic elastic materials. J. Mech. Phys. solids 55, 1001–1015] studied the problem of a rigid cylinder in non-slipping adhesive contact with a transversely isotropic solid subjected to an inclined pulling force. An implicit assumption made in their study was that the contact region remains symmetric with respect to the center of the cylinder. This assumption is, however, not self-consistent because the resulting energy release rates at two contact edges, which are supposed to be identical, actually differ from each other. Here we revisit the original problem of Chen and Gao and derive the correct solution by removing this problematic assumption. The corrected solution provides a proper insight into the concept of orientation-dependent adhesion strength in anisotropic elastic solids
360Roam: Real-Time Indoor Roaming Using Geometry-Aware 360 Radiance Fields
Virtual tour among sparse 360 images is widely used while hindering
smooth and immersive roaming experiences. The emergence of Neural Radiance
Field (NeRF) has showcased significant progress in synthesizing novel views,
unlocking the potential for immersive scene exploration. Nevertheless, previous
NeRF works primarily focused on object-centric scenarios, resulting in
noticeable performance degradation when applied to outward-facing and
large-scale scenes due to limitations in scene parameterization. To achieve
seamless and real-time indoor roaming, we propose a novel approach using
geometry-aware radiance fields with adaptively assigned local radiance fields.
Initially, we employ multiple 360 images of an indoor scene to
progressively reconstruct explicit geometry in the form of a probabilistic
occupancy map, derived from a global omnidirectional radiance field.
Subsequently, we assign local radiance fields through an adaptive
divide-and-conquer strategy based on the recovered geometry. By incorporating
geometry-aware sampling and decomposition of the global radiance field, our
system effectively utilizes positional encoding and compact neural networks to
enhance rendering quality and speed. Additionally, the extracted floorplan of
the scene aids in providing visual guidance, contributing to a realistic
roaming experience. To demonstrate the effectiveness of our system, we curated
a diverse dataset of 360 images encompassing various real-life scenes,
on which we conducted extensive experiments. Quantitative and qualitative
comparisons against baseline approaches illustrated the superior performance of
our system in large-scale indoor scene roaming
Moho Depth Variations From Receiver Function Imaging in the Northeastern North China Craton and Its Tectonic Implications
A detailed knowledge of the crustal thickness in the northeastern North China Craton (NCC) is important for understanding the unusual Phanerozoic destruction of the craton. We achieve this goal by employing a 2‐D wave equation‐based migration method to P receiver functions from 198 broadband seismic stations, using Ps conversions and surface‐reflected multiples. By combining receiver function images along 19 profiles, we constructed a high‐resolution Moho depth model for the northeastern NCC. The results present dominant E‐W Moho depth variations similar to previous observations and new regional N‐S variations beneath both sides of the North‐South Gravity Lineament. To the west, while a deeper Moho (∼42 km) appears in the interior of the Trans‐North China Orogen, a relatively shallow Moho (∼38 km) exists in the northern margin of the Trans‐North China Orogen to western NCC. To the east, the crust beneath the Yan Mountains in the marginal area is thicker (∼32–40 km) than that (∼26–32 km) beneath the Bohai Bay Basin in the craton interior, and the Moho further shallows from NE (∼32 km) to SW (∼26 km) within the basin. Along with other observations, we conclude that the dominant E‐W difference may have been associated with the Paleo‐Pacific plate subduction under eastern Asia since the Mesozoic. The newly observed complex N‐S variations may have reflected the structural heterogeneity of the cratonic lithosphere inherited since the formation of the NCC in the Paleoproterozoic, or spatially uneven effects on the cratonic lithosphere of subsequent thermotectonic events during the long‐term evolution of the craton, or both.This research
is funded by the National Natural
Science Foundation of China (grant
41574034, 41688103, 91414301).
Figures are made with GMT
(http://gmt.soest.hawaii.edu) and
MATLAB softwares
(https://www.mathworks.com)
Patterned nanostructure in AgCo/Pt/MgO(001) thin film
The formation of patterned nanostructure in AgCo/Pt/MgO(001) thin film is
simulated by a technique of combining molecular dynamics and phase-field
theory. The dislocation (strain) network existing in Pt/MgO is used as a
template whose pattern is transferred to AgCo phase in spinodal decomposition,
resulting in regular arrays of Co islands that are attracted by the
dislocations. The influence of various factors, such as component concentration
and film thickness, is studied. It is found that the spinodal decomposition of
AgCo in this system is mainly characterized by a competition between a
surface-directed layer structure and the strain-induced patterned structure,
where the patterned Ag-Co structure only dominates in a small range near the
interface (less than 10 atomic layers). However, if the interlayer diffusion
can be minimized by controlling film growth conditions, it is shown that the
patterned structure can be formed throughout the entire film.Comment: 8 pages, 12 figure
Soft Matrices Suppress Cooperative Behaviors among Receptor-Ligand Bonds in Cell Adhesion
The fact that biological tissues are stable over prolonged periods of time while individual receptor-ligand bonds only have limited lifetime underscores the critical importance of cooperative behaviors of multiple molecular bonds, in particular the competition between the rate of rupture of closed bonds (death rate) and the rate of rebinding of open bonds (birth rate) in a bond cluster. We have recently shown that soft matrices can greatly increase the death rate in a bond cluster by inducing severe stress concentration near the adhesion edges. In the present paper, we report a more striking effect that, irrespective of stress concentration, soft matrices also suppress the birth rate in a bond cluster by increasing the local separation distance between open bonds. This is shown by theoretical analysis as well as Monte Carlo simulations based on a stochastic-elasticity model in which stochastic descriptions of molecular bonds and elastic descriptions of interfacial force/separation are unified in a single modeling framework. Our findings not only are important for understanding the role of elastic matrices in cell adhesion, but also have general implications on adhesion between soft materials
The role of vacuolar processing enzyme (VPE) from Nicotiana benthamiana in the elicitor-triggered hypersensitive response and stomatal closure
Elicitors/pathogen-associated molecular patterns (PAMPs) trigger the plant immune system, leading to rapid programmed cell death (hypersensitive response, HR) and stomatal closure. Previous reports have shown that the vacuolar processing enzyme (VPE), a cysteine proteinase responsible for the maturation of vacuolar proteins, has caspase-1-like activity and mediates TMV- and mycotoxin-induced cell death. The role of VPE from Nicotiana benthamiana in the response to three elicitors: bacterial harpin, fungal Nep1, and oomycete boehmerin, is described here. Single-silenced (NbVPE1a or NbVPE1b) and dual-silenced (NbVPE1a/1b) N. benthamiana plants were produced by virus-induced gene silencing. Although NbVPE silencing does not affect H2O2 accumulation triggered by boehmerin, harpin, or Nep1, the HR is absent in NbVPE1a- and NbVPE1a/1b-silenced plants treated with harpin alone. However, NbVPE-silenced plants develop a normal HR after boehmerin and Nep1 treatment. These results suggest that harpin-triggered HR is VPE-dependent. Surprisingly, all gene-silenced plants show significantly impaired elicitor-induced stomatal closure and elicitor-promoted nitric oxide (NO) production in guard cells. Dual-silenced plants show increased elicitor-triggered AOS production in guard cells. The accumulation of transcripts associated with defence and cell redox is modified by VPE silencing in elicitor signalling. Overall, these results indicate that VPE from N. benthamiana functions not only in elicitor-induced HR, but also in elicitor-induced stomatal closure, suggesting that VPE may be involved in elicitor-triggered immunity
Comparative evaluation of sump drainage by trocar puncture, percutaneous catheter drainage versus operative drainage in the treatment of Intra-abdominal abscesses: a retrospective controlled study
Role of enteral nutrition in nonthyroidal illness syndrome: a retrospective observational study
Many Labs 2: Investigating Variation in Replicability Across Samples and Settings
We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories. Using the conventional criterion of statistical significance (p < .05), we found that 15 (54%) of the replications provided evidence of a statistically significant effect in the same direction as the original finding. With a strict significance criterion (p < .0001), 14 (50%) of the replications still provided such evidence, a reflection of the extremely highpowered design. Seven (25%) of the replications yielded effect sizes larger than the original ones, and 21 (75%) yielded effect sizes smaller than the original ones. The median comparable Cohen’s ds were 0.60 for the original findings and 0.15 for the replications. The effect sizes were small (< 0.20) in 16 of the replications (57%), and 9 effects (32%) were in the direction opposite the direction of the original effect. Across settings, the Q statistic indicated significant heterogeneity in 11 (39%) of the replication effects, and most of those were among the findings with the largest overall effect sizes; only 1 effect that was near zero in the aggregate showed significant heterogeneity according to this measure. Only 1 effect had a tau value greater than .20, an indication of moderate heterogeneity. Eight others had tau values near or slightly above .10, an indication of slight heterogeneity. Moderation tests indicated that very little heterogeneity was attributable to the order in which the tasks were performed or whether the tasks were administered in lab versus online. Exploratory comparisons revealed little heterogeneity between Western, educated, industrialized, rich, and democratic (WEIRD) cultures and less WEIRD cultures (i.e., cultures with relatively high and low WEIRDness scores, respectively). Cumulatively, variability in the observed effect sizes was attributable more to the effect being studied than to the sample or setting in which it was studied.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP
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