"A continuous awaking movement". Note sul choreocinema di Maya Deren

Maya Deren ha prodotto tra gli anni quaranta e la metà degli anni cinquanta del secolo scorso un cinema visionario in cui la danza e i danzatori diventano i protagonisti della trasfigurazione del reale in arte, del viaggio dal mondo visibile a quello invisibile delle forme sottili dell’inconscio e della mente. Il saggio si incentra sul ciclo di film di Maya Deren che John Martin, critico di danza del New York Times e teorico di punta della modern dance, definì come choreocinema: >, soffermandosi principalmente su A Study in Choreography for Camera del 1945 che Deren creò collaborando con il danzatore afro-americano Talley Beatty

Select2Col: Leveraging Spatial-Temporal Importance of Semantic Information for Efficient Collaborative Perception

Collaboration by leveraging the shared semantic information plays a crucial role in overcoming the perception capability limitations of isolated agents. However, existing collaborative perception methods tend to focus solely on the spatial features of semantic information, while neglecting the importance of the temporal dimension. Consequently, the potential benefits of collaboration remain underutilized. In this article, we propose Select2Col, a novel collaborative perception framework that takes into account the {s}patial-t{e}mpora{l} importanc{e} of semanti{c} informa{t}ion. Within the Select2Col, we develop a collaborator selection method that utilizes a lightweight graph neural network (GNN) to estimate the importance of semantic information (IoSI) in enhancing perception performance, thereby identifying contributive collaborators while excluding those that bring negative impact. Moreover, we present a semantic information fusion algorithm called HPHA (historical prior hybrid attention), which integrates multi-scale attention and short-term attention modules to capture the IoSI in feature representation from the spatial and temporal dimensions respectively, and assigns IoSI-consistent weights for efficient fusion of information from selected collaborators. Extensive experiments on two open datasets demonstrate that our proposed Select2Col significantly improves the perception performance compared to state-of-the-art approaches. The code associated with this research is publicly available at https://github.com/huangqzj/Select2Col/

Ginsenoside Rb1 promotes angiogenesis potentially by activating the JAK-STAT3 signalling pathway

Conventional revascularization strategies for ischemic heart disease (IHD) are designed to prompt reperfusion of the coronary artery to the salvaged cardiomyocytes. However, these strategies may cause myocardial reperfusion injuries. Therefore, a safe and effective strategy needs to be developed to improve the conventional strategies. Here, we investigated the pro-angiogenic effect of Ginsenoside Rb1 (Rb1) to provide the experimental basis for angiogenesis-mediated drug therapy of IHD. Thus, Human umbilical vein endothelial cells (HUVECs) were treated with either a vehicle or Rb1 at 4, 8, 12 or 16 μM for 24 h. A model of hindlimb ischemia was established using C57BL/6J mice. In sham-operated mice, only the femoral artery was isolated without ligation whereas the other operations and supplementation control group were consistent. The mice in the supplementation group were injected with Rb1 (50 mg/kg body wt./day) for 7 days. The results indicated that Rb1 promotes cell proliferation, adhesion, migration and tube formation in the HUVECs in a dose-dependent manner. The ED50 of Rb1 to improve cell adhesion is 8 μM. In mice, Rb1 promoted angiogenesis after the ligation of the femoral artery and ameliorated the ischemic conditions. Intriguingly, more blood flow recovery was observed in the Rb1 supplemented mice than in the vehicle-treated mice (0.85 ± 0.05 vs. 0.71±0.10 on day 3; 0.94±0.10 vs. 0.75±0.08 on day 7). In HUVECs, Rb1 increased the phosphorylation of STAT3 and JAK, which may be the mechanism through which Rb1 mitigates IHD. Moreover, our results confirmed that Rb1mitigates IHD potentially by activating the JAK-STAT3 pathway. Further clinical trials are warranted to verify the clinical implications of Rb1

Evolution of pore structure and adsorption-desorption in oil shale formation rocks after compression

As the extensive application of reservoir stimulation technologies such as hydraulic fracturing (including CO2 fracturing) and in-situ conversion, identifying the developing rules of the pore structure in shale formations rocks after compression becomes all the more important. Here we carry out experimental studies to reveal the evolution mechanism of pore structure of oil shale formation rocks after compression primarily via adsorptiondesorption isotherms. The results show that the BET specific surface area of the oil shale rocks first increases and then decreases after the confined compression, while the second dominant peak of pore size distribution shows the opposite behaviors. The pore volume experiences the stage of decrease, increase and continuous decrease with the increasing applied stress, and at last decreases by -30% under 700 MPa compression. The increase of fractal dimension of shale formation rocks after compression indicates that the pore structure gets rougher and more heterogeneous. It reveals that the pore structure and pore-system of shale rock experience a very complexed evolution during the compression, including compressing, cementing, splitting and vanishing. This work provides some guidelines for the rational design of stimulation technologies to improve shale oil and gas recovery, and the carbon sequestration in deep earth formations

A bilayer color digital image correlation method for the measurement of the topography of a liquid interface

One of the most essential characteristics of the liquid interface is the topography dominated by hydrodynamics or capillary effects. Although there have developed 3D imaging techniques for the measurement of such topography, their setups, operations and reconstructions are relatively complex and suffer from low efficiency. Here we report a bilayer color digital image correlation (BC-DIC) method for the measurement of the topography of a liquid interface. The basic principle of the new method is the refraction of beneath bilayer color speckle patterns at the liquid interface, which makes it possible to perform 3D reconstruction through 2D measurement of the virtual displacement field of the speckle patterns. The equations for BC-DIC in different situations are deduced and discussed in detailed. Validation experiments are carried out to reconstruct the topography of triangular prism, planoconvex, complex transparent surface and sloshing water surface. The results show that BC-DIC is feasible and accurate for measuring the topography of transparent objects, including liquid interface. This new method paves the way for investigating surface and interface phenomena, such as capillarity and wetting issues, hydrodynamics on liquid interface, etc

The effects of non-inverse-square-root stress singularity on some crack propagation criteria in hydraulic fracturing

Numerous crack propagation criteria have been employed in numerical investigations of hydraulic fracturing. Some criteria rely on linear elastic fracture mechanics, which assume the presence of an inverse-square-root stress singularity and an elliptical crack profile. However, it has been observed that hydraulic fracturing exhibits a weaker stress singularity, which is governed by a dimensionless parameter known as apparent fracture toughness. This parameter represents the energy required to fracture the solid compared to the energy needed to overcome fluid friction. Abnormal stress singularity was found for the viscosity dominated regime where the apparent fracture toughness approaches zero from the positive side. Variations in results can occur when different criteria are employed, primarily due to the breakdown of the inverse-square-root stress singularity. In this paper, a mathematical model utilizing a straight slit crack was employed to investigate these discrepancies. Four commonly used criteria were implemented in the same mathematical model, and high-precision methods based on modified Chebyshev polynomials and implicit algorithms were employed for calculations. The transient crack dimensions and wellbore pressure were found to diverge for these criteria. Notably, the CTOD, CDM, and FPZ criteria were found to be challenging to apply in the viscosity-dominated regime where the apparent fracture toughness was less than 1.0. The underlying mechanisms were discussed based on crack tip asymptotics and crack opening behavior. This study provides valuable insights for selecting appropriate crack propagation criteria in hydraulic fracturing

Combining Image Recognition and Simulation To Reproduce the Adsorption/Desorption Behaviors of Shale Gas

Shale gas stored in deep shale is in a supercritical state. Therefore, it is necessary to study the adsorption and desorption properties of supercritical shale gas. To accurately determine the state of methane (CH4) in the pores of deep shale, the fractal characteristics of several shale samples drilled at a depth of 2650 m are analyzed using scanning electron microscopy (SEM) and image analysis. We find nanopores with different fractal features in the shale. The effects of adsorption energy and substrate strain on adsorption capacity are clarified. The virial coefficients of CH4 are obtained by molecular dynamics (MD) simulations and are consistent with the experiment. The adsorption and desorption of CH4 in different fractal nanopores are modeled using grand canonical Monte Carlo (GCMC) simulations at different temperatures and pressures (from capillary condensation to supercritical state). Additionally, the gas-in-place (GIP), excess adsorption, and absolute adsorption isotherms are obtained. We find the crossover of excess adsorption isotherms, which was observed in the experiment, and the absolute adsorption amount increases with the increase in pressure in the case of ultrahigh pressure (>40 MPa). Moreover, we obtain an ultrahigh-pressure dual-site Langmuir equation, and it can accurately describe observed adsorption isotherms from low pressure to ultrahigh pressure. Our study visually reproduces the adsorption/desorption behaviors of CH4 under in situ conditions in deep shale and reveals their microscopic mechanism

Electro-capillary peeling of thin films

Thin films are widely-used functional materials that have attracted much interest in academic and industrial applications. With thin films becoming micro/nanoscale, developing a simple and nondestructive peeling method for transferring and reusing the films remains a major challenge. Here, we develop an electro-capillary peeling strategy that achieves thin film detachment by driving liquid to percolate and spread into the bonding layer under electric fields, immensely reducing the deformation and strain of the film compared with traditional methods (reaching 86%). Our approach is evaluated via various applied voltages and films, showing active control characterizations and being appropriate for a broad range of films. Theoretically, electro-capillary peeling is achieved by utilizing the Maxwell stress to compete with the film's adhesion stress and tension stress. This work shows the great potential of the electro-capillary peeling method to provide a simple way to transfer films and facilitates valid avenues for reusing soft materials. Current methods for thin film peeling suffer from limitations because of complicated preparations and the limitations of applied films. Li et al. present a peeling method for the thin film's detachment that is achieved by driving liquid to percolate and spread into the bonding layer under electric fields