Abstract E-commerce provides a large selection of goods for sale and purchase, which promotes regular transactions and commodity flows. Efficient distribution of goods and precise estimation of ...customer wants are essential for cost reduction. In order to improve supply chain efficiency in the context of cross-border e-commerce, this article combines machine learning approaches with the Internet of Things. The suggested approach consists of two main stages. Order prediction is done in the first step to determine how many orders each merchant is expected to get in the future. In the second phase, allocation operations are conducted and resources required for each retailer are supplied depending on their needs and inventory, taking into account each store’s inventory as well as the anticipated sales level. This suggested approach makes use of a weighted mixture of neural networks to anticipate sales orders. The Capuchin Search Algorithm (CapSA) is used in this weighted combination to concurrently enhance the learning and ensemble performance of models. This indicates that an effort is made to reduce the local error of the learning model at the model level via model weight adjustments and neural network configuration. To guarantee more accurate output from the ensemble model, the best weight for each individual component is found at the ensemble model level using the CapSA method. This method yields the ensemble model’s final output in the form of weighted averages by choosing suitable weight values. With a Root Mean Squared Error of 2.27, the suggested technique has successfully predicted sales based on the acquired findings, showing a minimum decrease of 2.4 in comparison to the comparing methodologies. Additionally, the suggested method’s strong performance is shown by the fact that it was able to minimize the Mean Absolute Percentage Error by 14.67 when compared to other comparison approaches.
Mismatched nucleotides arise from polymerase misincorporation errors, recombination between heteroallelic parents and chemical or physical DNA damage. Highly conserved MutS (MSH) and MutL (MLH/PMS) ...homologues initiate mismatch repair and, in higher eukaryotes, act as DNA damage sensors that can trigger apoptosis. Defects in human mismatch repair genes cause Lynch syndrome or hereditary non-polyposis colorectal cancer and 10-40% of related sporadic tumours. However, the collaborative mechanics of MSH and MLH/PMS proteins have not been resolved in any organism. We visualized Escherichia coli (Ec) ensemble mismatch repair and confirmed that EcMutS mismatch recognition results in the formation of stable ATP-bound sliding clamps that randomly diffuse along the DNA with intermittent backbone contact. The EcMutS sliding clamps act as a platform to recruit EcMutL onto the mismatched DNA, forming an EcMutS-EcMutL search complex that then closely follows the DNA backbone. ATP binding by EcMutL establishes a second long-lived DNA clamp that oscillates between the principal EcMutS-EcMutL search complex and unrestricted EcMutS and EcMutL sliding clamps. The EcMutH endonuclease that targets mismatch repair excision only binds clamped EcMutL, increasing its DNA association kinetics by more than 1,000-fold. The assembly of an EcMutS-EcMutL-EcMutH search complex illustrates how sequential stable sliding clamps can modulate one-dimensional diffusion mechanics along the DNA to direct mismatch repair.
This paper is devoted to study a class of
p
(
x
)-Kirchhoff equation with concave–convex nonlinearities. By means of perturbation technique and the variational method, the multiplicity of nonnegative ...nontrivial solutions to this problem is obtained.
Highly conserved MutS and MutL homologs operate as protein dimers in mismatch repair (MMR). MutS recognizes mismatched nucleotides forming ATP-bound sliding clamps, which subsequently load MutL ...sliding clamps that coordinate MMR excision. Several MMR models envision static MutS-MutL complexes bound to mismatched DNA via a positively charged cleft (PCC) located on the MutL N-terminal domains (NTD). We show MutL-DNA binding is undetectable in physiological conditions. Instead, MutS sliding clamps exploit the PCC to position a MutL NTD on the DNA backbone, likely enabling diffusion-mediated wrapping of the remaining MutL domains around the DNA. The resulting MutL sliding clamp enhances MutH endonuclease and UvrD helicase activities on the DNA, which also engage the PCC during strand-specific incision/excision. These MutS clamp-loader progressions are significantly different from the replication clamp-loaders that attach the polymerase processivity factors β-clamp/PCNA to DNA, highlighting the breadth of mechanisms for stably linking crucial genome maintenance proteins onto DNA.
Sand liquefaction triggered by earthquakes is a devastating geological disaster and has emerged as an engaging topic in earthquake engineering. With an enhanced understanding of pure sand ...liquefaction promoted by laboratory research, there is a growing concern, following filed investigations, over the influence of fine particles on the liquefaction potential of sand containing inclusions. Efforts have been devoted to clarifying the significance of certain physical indicators (e.g., plasticity index, particle shape and gradation characteristics), and fruitful conclusions can be found in the published literature. However, the relationship between the content of fine particles and the cyclic degradation in liquefaction process seems still unclear. To fill this knowledge gap, three sets of cyclic triaxial tests were performed on various sand–fines mixtures with the dry tamping method. The experimental results revealed that (i) fine particles provided a negative contribution to the global soil structure; (ii) however, the damping ratio measured from the obtained stress–strain loops manifested its independence from the fines content during cyclic degradation. In this paper, we propose a shearing mechanism on the microscopic scale to explain the above contrasting observations. For a given soil fabric, the fine particles around sand-to-sand contact points probably break strong force chains, intensifying the threat of liquefaction. By contrast, these fines play the same role in favouring relative sliding between sand grains during both the loading and unloading stages. As the maximum stored energy and the energy loss per cycle are amplified with the same scaling factor, the damping ratio, defined as the ratio between them, should display a macroscopic invariance in triaxial tests.
A shared paradigm of mismatch repair (MMR) across biology depicts extensive exonuclease-driven strand-specific excision that begins at a distant single-stranded DNA (ssDNA) break and proceeds back ...past the mismatched nucleotides. Historical reconstitution studies concluded that Escherichia coli (Ec) MMR employed EcMutS, EcMutL, EcMutH, EcUvrD, EcSSB and one of four ssDNA exonucleases to accomplish excision. Recent single-molecule images demonstrated that EcMutS and EcMutL formed cascading sliding clamps on a mismatched DNA that together assisted EcMutH in introducing ssDNA breaks at distant newly replicated GATC sites. Here we visualize the complete strand-specific excision process and find that long-lived EcMutL sliding clamps capture EcUvrD helicase near the ssDNA break, significantly increasing its unwinding processivity. EcSSB modulates the EcMutL-EcUvrD unwinding dynamics, which is rarely accompanied by extensive ssDNA exonuclease digestion. Together these observations are consistent with an exonuclease-independent MMR strand excision mechanism that relies on EcMutL-EcUvrD helicase-driven displacement of ssDNA segments between adjacent EcMutH-GATC incisions.
One-dimensional (1D) sliding of DNA-binding proteins has been observed by numerous kinetic studies. It appears that many of these sliding events play important roles in a wide range of biological ...processes. However, one challenge is to determine the physiological relevance of these motions in the context of the protein's biological function. Here, we discuss methods of measuring protein 1D sliding by highlighting the single-molecule approaches that are capable of visualizing particle movement in real time. We also present recent findings that show how protein sliding contributes to function.
The dynamic assembly of the Synaptic-soluble N-ethylmaleimide-sensitive factor Attachment REceptor (SNARE) complex is crucial to understand membrane fusion. Traditional ensemble study meets the ...challenge to dissect the dynamic assembly of the protein complex. Here, we apply minute force on a tethered protein complex through dual-trap optical tweezers and study the folding dynamics of SNARE complex under mechanical force regulated by complexin-1 (CpxI). We reconstruct the clamp and facilitate functions of CpxI in vitro and identify different interplay mechanism of CpxI fragment binding on the SNARE complex. Specially, while the N-terminal domain (NTD) plays a dominant role of the facilitate function, CTD is mainly related to clamping. And the mixture of 1-83aa and CTD of CpxI can efficiently reconstitute the inhibitory signal identical to that the full-length CpxI functions. Our observation identifies the important chaperone role of the CpxI molecule in the dynamic assembly of SNARE complex under mechanical tension, and elucidates the specific function of each fragment of CpxI molecules in the chaperone process.
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