Sorting Mechanism Research Articles

Lipid Profiles of RAS Nanoclusters Regulate RAS Function.

The lipid-anchored RAS (Rat sarcoma) small GTPases (guanosine triphosphate hydrolases) are highly prevalent in human cancer. Traditional strategies of targeting the enzymatic activities of RAS have been shown to be difficult. Alternatively, RAS function and pathology are mostly restricted to nanoclusters on the plasma membrane (PM). Lipids are important structural components of these signaling platforms on the PM. However, how RAS nanoclusters selectively enrich distinct lipids in the PM, how different lipids contribute to RAS signaling and oncogenesis and whether the selective lipid sorting of RAS nanoclusters can be targeted have not been well-understood. Latest advances in quantitative super-resolution imaging and molecular dynamic simulations have allowed detailed characterization RAS/lipid interactions. In this review, we discuss the latest findings on the select lipid composition (with headgroup and acyl chain specificities) within RAS nanoclusters, the specific mechanisms for the select lipid sorting of RAS nanoclusters on the PM and how perturbing lipid compositions within RAS nanoclusters impacts RAS function and pathology. We also describe different strategies of manipulating lipid composition within RAS nanoclusters on the PM.

Protein Sorting in Plasmodium Falciparum

Plasmodium falciparum is a unicellular eukaryote with a very polarized secretory system composed of micronemes rhoptries and dense granules that are required for host cell invasion. P. falciparum, like its relative T. gondii, uses the endolysosomal system to produce the secretory organelles and to ingest host cell proteins. The parasite also has an apicoplast, a secondary endosymbiotic organelle, which depends on vesicular trafficking for appropriate incorporation of nuclear-encoded proteins into the apicoplast. Recently, the central molecules responsible for sorting and trafficking in P. falciparum and T. gondii have been characterized. From these studies, it is now evident that P. falciparum has repurposed the molecules of the endosomal system to the secretory pathway. Additionally, the sorting and vesicular trafficking mechanism seem to be conserved among apicomplexans. This review described the most recent findings on the molecular mechanisms of protein sorting and vesicular trafficking in P. falciparum and revealed that P. falciparum has an amazing secretory machinery that has been cleverly modified to its intracellular lifestyle.

Spatially explicit modeling of community occupancy using Markov Random Field models with imperfect observation: Mesocarnivores in Apostle Islands National Lakeshore

How species organize spatially is one of ecology’s most motivating questions. Multiple theories have been advanced and various models developed to account for the environment, interactions among species, and spatial drivers. However, relative importance comparisons of explanatory phenomena generally are neglected in these analyses. We developed a spatially explicit community occupancy model based on Markov random fields that accounts for spatial auto-correlation and interspecific interactions in occupancy while also accounting for interspecific interaction in detection. Simulations demonstrated that the model can distinguish different mechanisms of environmental sorting, such as competition and spatial-autocorrelation. We applied our model to camera trap data from a fisher (Pekania pennanti)–marten (Martes americana) and coyote (Canis latrans)-fox (Vulpes vulpes) system in Apostle Island National Lakeshore (Wisconsin, USA). Model results indicated that the observed partitioning pattern between marten and fisher distributions could be explained best by a flipped mainland–island source–sink pattern rather than by competition. For the coyote–fox system, we determined that, in addition to a mainland–island source–sink pattern, there was a positive association between fox and coyote that deserved further study. Our model could be readily applied to other landscapes (island and non-island systems), enhancing our understanding of species coexistence patterns.

Towards Application-Driven Task Offloading in Edge Computing Based on Deep Reinforcement Learning.

Edge computing is a new paradigm, which provides storage, computing, and network resources between the traditional cloud data center and terminal devices. In this paper, we concentrate on the application-driven task offloading problem in edge computing by considering the strong dependencies of sub-tasks for multiple users. Our objective is to joint optimize the total delay and energy generated by applications, while guaranteeing the quality of services of users. First, we formulate the problem for the application-driven tasks in edge computing by jointly considering the delays and the energy consumption. Based on that, we propose a novel Application-driven Task Offloading Strategy (ATOS) based on deep reinforcement learning by adding a preliminary sorting mechanism to realize the joint optimization. Specifically, we analyze the characteristics of application-driven tasks and propose a heuristic algorithm by introducing a new factor to determine the processing order of parallelism sub-tasks. Finally, extensive experiments validate the effectiveness and reliability of the proposed algorithm. To be specific, compared with the baseline strategies, the total cost reduction by ATOS can be up to 64.5% on average.

Workplace Heterogeneity and the Returns to Versatility

Abstract In the canonical random on-the-job search model with continuous firm heterogeneity, I show that a mean-preserving spread of the firm-productivity distribution raises the returns to mobility, i.e., the inter-firm mobility of workers as measured by the number of outside contacts per employment spell. Both sorting and rent-share mechanisms play a role. In a further contribution, I distinguish frictional and structural impediments to mobility in order to establish a link between mobility and skills via the concept of versatility. Versatility enhances a person’s mobility since a mismatch between job requirements and the person’s skill set is less likely to occur. I provide some statistics in support of the discussed mechanisms. The findings are particularly intriguing in light of the concurrent rise in the productivity dispersion across firms and in the skill premium in many countries.

Better in Pictures

Better in Pictures

Receptor/Raft Ratio Is a Determinant for LRP6 Phosphorylation and WNT/β-Catenin Signaling.

Microdomains or lipid rafts greatly affect the distribution of proteins and peptides in the membrane and play a vital role in the formation and activation of receptor/protein complexes. A prominent example for the decisive impact of lipid rafts on signaling is LRP6, whose localization to the same lipid rafts domain as the kinase CK1γ is crucial for its successful phosphorylation and the subsequent activation of the signalosome, hence WNT/β-catenin signaling. However, according to various experimental measurements, approximately 25 to 35 % of the cell plasma membrane is covered by nanoscopic raft domains with diameters ranging between 10 to 200 nm. Extrapolating/Translating these values to the membrane of a “normal sized” cell yields a raft abundance, that, by far, outnumbers the membrane-associated pathway components of most individual signaling pathway, such as receptor and kinases. To analyze whether and how the quantitative ratio between receptor and rafts affects LRP6 phosphorylation and WNT/β-catenin pathway activation, we present a computational modeling study, that for the first time employs realistic raft numbers in a compartment-based pathway model. Our simulation experiments indicate, that for receptor/raft ratios smaller than 1, i.e., when the number of raft compartments clearly exceeds the number of pathway specific membrane proteins, we observe significant decrease in LRP6 phosphorylation and downstream pathway activity. Our results suggest that pathway specific targeting and sorting mechanism are required to significantly narrow down the receptor/raft ratio and to enable the formation of the LRP6 signalosome, hence signaling.

Functional kupffer cells migrate to the liver from the intraperitoneal cavity

We established a method of KC transplantation by intraperitoneal (i.p.) injection using EGFP-expressing cells (EGFP-KCs) and normal KCs. The novel method is easier and less invasive than conventional methods so that it is not only technically advantageous but also ethically preferable for experiments using animals. We demonstrated that KCs migrated to the liver following i.p. Injection. Engraftment in the liver was not observed for peritoneal macrophages (pMPs). This suggests that KCs migrate to the liver via a sorting mechanism. KC injection decreased the KC number at 24 h and then recovered the KCs at 10 days to a normal level. Additionally, recovery to the normal level by KC injection was observed in mice with KC depletion induced by GdCl3. These results suggest that a regulatory mechanism exists for controlling the number of KCs.

Elitist non-dominated sorting Harris hawks optimization: Framework and developments for multi-objective problems

This paper proposed a novel multi-objective non-sorted Harris Hawks Optimizer (NSHHO) part of the recently developed Harris Hawks Optimizer (HHO) based on an elitist non dominated sorting mechanism. The same Harris Hawks Optimizer methodology was issued for converging towards optimum solutions in a multiple-objective criterion search space. For obtained well-distributed Pareto optimal front and their solution has better coverage. However, a non-dominated ranking with the crowding distance strategy is applied to HHO. To check the performance of NSHHO, a total of 46 case studies include 13 un-constrained, 11 constrained, and 22 real-world design multiple-objective highly nonlinear constraint problems. The obtained results of the proposed NSHHO are compared with NSGA-II, MOPSO and MOEA/D, quantitatively, and different performance metrics are compared qualitatively, which represents the advantage of the newly proposed NSHHO algorithm in solving the unconstrained, constrained, and real-world problems with different linear, nonlinear, continuous and discrete characteristics based Pareto front. We think the proposed NSHHO can be viral as an effective multi-objective optimizer within the field. The open-source software of NSHHO is publicly provided at https://codeocean.com/capsule/2034037/tree and https://aliasgharheidari.com/HHO.html.

Calcium levels in the Golgi complex regulate clustering and apical sorting of GPI-APs in polarized epithelial cells

Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are lipid-associated luminal secretory cargoes selectively sorted to the apical surface of the epithelia where they reside and play diverse vital functions. Cholesterol-dependent clustering of GPI-APs in the Golgi is the key step driving their apical sorting and their further plasma membrane organization and activity; however, the specific machinery involved in this Golgi event is still poorly understood. In this study, we show that the formation of GPI-AP homoclusters (made of single GPI-AP species) in the Golgi relies directly on the levels of calcium within cisternae. We further demonstrate that the TGN calcium/manganese pump, SPCA1, which regulates the calcium concentration within the Golgi, and Cab45, a calcium-binding luminal Golgi resident protein, are essential for the formation of GPI-AP homoclusters in the Golgi and for their subsequent apical sorting. Down-regulation of SPCA1 or Cab45 in polarized epithelial cells impairs the oligomerization of GPI-APs in the Golgi complex and leads to their missorting to the basolateral surface. Overall, our data reveal an unexpected role for calcium in the mechanism of GPI-AP apical sorting in polarized epithelial cells and identify the molecular machinery involved in the clustering of GPI-APs in the Golgi.

The influence of internal motivation and external publicity on consumers' waste sorting behaviour.

Waste sorting is an important aspect of environmental protection, which is now being enforced on a large scale in China. More broadly, it is beneficial to improve the implementation strategies for waste sorting policy and programmes. This study analyses the psychology of consumers that influences the mechanisms of consumer waste sorting and the governmental policies influencing consumers' attitudes and behaviours. About 295 validated participants were collected from four regions of China. Regression analysis was used to examine the relationship among consumers' internal motivation, government's external publicity and consumer behaviour, and the Hayes' PROCESS macro was used to test mediating effect and moderating effect. The results show that consumers' internal motivation and government's external publicity have a positive effect on consumer behaviour. Consumer attitude played a complete mediating role between consumers' internal motivation and consumer behaviour. Between the government's external publicity and consumer behaviour, consumer attitude played a complementary mediating role. Consumers with self-transcendence values, positive motivation of waste sorting and the government's external publicity had a greater positive impact on their attitudes than consumers with self-enhancement values. The greater the material benefits and psychic income consumers received from waste sorting, the more it promoted a positive attitude to consumer behaviour. The article puts forward some management suggestions to improve the government's implementation of its waste sorting policy.

Equity Short Selling and the Bank Loan Market

AbstractUsing a difference‐in‐differences approach, we show that relaxation of short‐sale constraints helps to filter out low‐quality borrowers from the bank loan market. Treated firms that can still borrow from banks enjoy a lower loan spread, compared with control firms without this sorting mechanism. The results show that such treated borrowers have improved information asymmetry and credit risk, as well as better nonprice contract terms. Overall, equity short selling has a real effect on the bank loan market by weeding out poor‐quality borrowers, resulting in a lower cost of private debt for remaining borrower firms.

An ant colony algorithm model for UAV sense and avoid based on ADS-B

In the context of airspace fusion, in order to improve the safety performance of UAV and prevent the occurrence of air collision accidents, an ant colony algorithm model for UAV sense and avoid based on ADS-B monitoring technology is proposed. The model mainly consists of two parts: the deterministic conflict detection model makes the full use of ADS-B information to calculate the geometric distance from the horizontal and vertical planes to identify the conflict target, and the conflict resolution model is based on the ant colony algorithm which introduces the comprehensive heuristic function and sorting mechanism to plan the route again for achieving the collision avoidance. The simulation results show that the conflict detection model can effectively identify the possible threat targets, and the conflict resolution model is not only suitable for the typical two aircraft conflict scenarios, but also can provide a better resolution strategy for the complex multiple aircraft conflict scenarios.

Design and experiment of intelligent sorting and transplanting system for healthy vegetable seedlings

Healthy vegetable seedlings are surviving seedlings with good biological characteristics. Selective planting of healthy seedlings in the mechanized transplanting process can effectively avoid the reduction in yield caused by missed planting. Aiming at the current transplanting machinery that cannot achieve the selective planting of healthy seedlings, a healthy seedling intelligent sorting and transplanting system was proposed. The system consisted of a seedling delivery mechanism, sorting mechanism, photoelectric sensor, image sensor, PLC control system, and computer control system. It can realize automatic transmission of seedling trays, automatically identify the information of healthy seedlings in the trays and selectively transplant them. Also it can reduce the missed planting rate caused by the poor quality of plug seedlings after planting and the lack of seedlings in the hole. A sorting test of plug seedlings was carried out for the age-appropriate pepper plug seedlings cultivated in the factory. The results showed that the system had an average recognition accuracy rate of 89.14% and an average sorting success rate of 93.20% in the process of sorting suitable age pepper plug seedlings. The whole system can identify, sort and transplant the plug seedlings of appropriate age according to healthy information, and effectively avoid missing planting. This research can provide technical support for the intelligent upgrade of transplanting equipment. Keywords: intelligent agriculture, sorting and transplanting system, healthy vegetable seedling, design, experiment, image, sensor DOI: 10.25165/j.ijabe.20211404.6169 Citation: Li M Y, Jin X, Ji J T, Li P G, Du X W. Design and experiment of intelligent sorting and transplanting system for healthy vegetable seedlings. Int J Agric & Biol Eng, 2021; 14(4): 208–216.

Glycosylation Modulates Plasma Membrane Trafficking of CD24 in Breast Cancer Cells.

In breast cancer, expression of Cluster of Differentiation 24 (CD24), a small GPI-anchored glycoprotein at the cell periphery, is associated with metastasis and immune escape, while its absence is associated with tumor-initiating capacity. Since the mechanism of CD24 sorting is unknown, we investigated the role of glycosylation in the subcellular localization of CD24. Expression and localization of wild type N36- and/or N52-mutated CD24 were analyzed using immunofluorescence in luminal (MCF-7) and basal B (MDA-MB-231 and Hs578T) breast cancer cells lines, as well as HEK293T cells. Endogenous and exogenously expressed wild type and mutated CD24 were found localized at the plasma membrane and the cytoplasm, but not the nucleoplasm. The cell lines showed different kinetics for the sorting of CD24 through the secretory/endocytic pathway. N-glycosylation, especially at N52, and its processing in the Golgi were critical for the sorting and expression of CD24 at the plasma membrane of HEK293T and basal B type cells, but not of MCF-7 cells. In conclusion, our study highlights the contribution of N-glycosylation for the subcellular localization of CD24. Aberrant N-glycosylation at N52 of CD24 could account for the lack of CD24 expression at the cell surface of basal B breast cancer cells.

Heavy mineral composition and texture of the recently formed fluvial delta sediment of Lake Nasser/Nubia, Egypt and Sudan

Surficial sediment samples collected from the recently formed fluvial delta in Lake Nasser/Nubia (Egypt and Sudan) in conjunction with data on bottom current and depth soundings are examined to interpret hydraulic-sorting processes and transport/depositional patterns. The ~500 km long northeastward-trending lake, lies within Egypt and Sudan, is created as a result of the construction of the Aswan High Dam in 1964. The original grain-size distribution and heavy mineral compositions of these samples help to characterize the classical depositional features of the recently formed underwater delta-front and prodelta depocenters. Starting from the south, those delta-front deposits, which floor most of the narrow-shallow basin of Lake Nubia, are characterized by thick coarse-grained sandy deposits, rich in heavy minerals (averaged 12.8%). This delta-front is followed to the northeast by thin layers of prodelta mud, poor in heavy mineral contents (averaged 0.6%). These layers cover the entire broad basin of Lake Nasser. The northeasterly downslope fining-trend, along with a continuous decrease in heavy mineral composition, along the length of the lake, are attributable to processes of grain sorting, which take place due to contrasting densities and grain sizes. These processes lead to the concentration of heavy mineral placer, mostly in the delta-front samples. The sorting mechanism, in turn, is controlled by the interplay of unidirectional-directed northeastward current, physiographic characteristics of the lake, including topographic configuration, geometry (cross-section), and floor topography (slope gradient). In terms of mineral exploration, the highest proportion of mineral grades in the delta-front sediments is likely to be considered as a viable source for economic placers that require more planning initiatives for industrial and commercial evaluation.

Differential RNA packaging into small extracellular vesicles by neurons and astrocytes

BackgroundSmall extracellular vesicles (sEVs) mediate intercellular communication by transferring RNA, proteins, and lipids to recipient cells. These cargo molecules are selectively loaded into sEVs and mirror the physiological state of the donor cells. Given that sEVs can cross the blood–brain barrier and their composition can change in neurological disorders, the molecular signatures of sEVs in circulation can be potential disease biomarkers. Characterizing the molecular composition of sEVs from different cell types is an important first step in determining which donor cells contribute to the circulating sEVs.MethodsCell culture supernatants from primary mouse cortical neurons and astrocytes were used to purify sEVs by differential ultracentrifugation and sEVs were characterized using nanoparticle tracking analysis, transmission electron microscopy and western blot. RNA sequencing was used to determine differential expression and loading patterns of miRNAs in sEVs released by primary neurons and astrocytes. Motif analysis was conducted on enriched miRNAs in sEVs and their respective donor cells.ResultsSequencing total cellular RNA, and miRNAs from sEVs isolated from culture media of postnatal mouse cortical neurons and astrocytes revealed a distinct profile between sEVs and their corresponding cells. Though the total number of detected miRNAs in astrocytes was greater than neurons, neurons expressed more sEV-associated miRNAs than astrocytes. Only 20.7% of astrocytic miRNAs were loaded into sEVs, while 41.0% of neuronal miRNAs were loaded into sEVs, suggesting differences in the cellular sorting mechanisms. We identified short RNA sequence motifs, or EXOmotifs, on the miRNAs that were differentially loaded or excluded from sEVs. A sequence motif GUAC was enriched in astrocytic sEVs. miRNAs preferably retained in neurons or astrocytes had a similar RNA motif CACACA, suggesting a cell-type-independent mechanism to maintain cellular miRNAs. mRNAs of five RNA-binding proteins associated with passive or active RNA sorting into sEVs were differentially expressed between neurons and astrocytes, one of which, major vault protein was higher in astrocytes than in neurons and detected in astrocytic sEVs.ConclusionsOur studies suggest differences in RNA sorting into sEVs. These differences in miRNA signatures can be used for determining the cellular sources of sEVs altered in neurological disorders.Emuizutjr-v5CYc2kJPkrbVideo abstract

Consumer Vigilance and Choice Overload in Online Shopping

Are there too many options in online shopping? Although extant studies have largely focused on the effects of choice overload, few shed light on choice overload in online shopping situations. In light of online shopping’s untouchable nature and sorting mechanisms, we argue that choice overload in online shopping is associated with consumer vigilance and assortment desirability. Across four experiments, we found that the size of the online choice set significantly influences consumers’ choice difficulty and choice deferral. We also discovered that consumer vigilance and assortment desirability moderate these relationships. Specifically, high vigilance increases the negative impact of assortment size on consumer decision, whereas assortment product desirability alleviates this consequence. We contribute to the literature by extending prior predictions of choice overload and proposing a framework involving choice overload, vigilance, and desirability for future research.

Can the New Waste Morphology Method Predict Sorting Plants Operational and Financial Challenges? A Case Study in Sharjah

This article presents a new approach to analysing municipal waste (MSW) composition, which makes it possible to envisage sorting process efficiency and predict valuable secondary raw material (SRM) losses during sorting. The study also enables to foresee financial losses related to the quality recyclables that are reclaimed from MSW. In this article, samples from MSW delivered to Bee’ah site in Sharjah in the United Arab Emirates (UAE) were analysed to define their composition. The novelty in this research was the mechanical and physical property analysis for the MSW components and the prediction mechanism used to foresee the possible recovery rate of a potential mechanical sorting process. The results were compared with those that would be obtained from traditional composition analysis to end up with shocking results. It was concluded that any mechanical sorting process, designed based on traditional analysis data, is mostly to face tremendous operational and financial challenges in the UAE. This is due to the input material shape, size, moisture content and other factors that change the way SRM components respond to sorting mechanisms. The study was able not only to explain the challenges faced by all the UAE sorting facilities, but also to show how to prevent such unsatisfactory performance in the future. The study concluded the reasons behind the MSW component deterioration and provided additional recommendations to extract more benefits from the new waste morphology approach.

Adaptive constraint differential evolution for optimal power flow

The optimal power flow (OPF) problem featured as a non-linear, non-convex, large-scale and constrained, still remains a popular and challenging work in power systems optimization. Although various optimization algorithms have been devoted to solving this problem, they suffer from some weak points such as insufficient accuracy as well as most of them are unconstrained optimization algorithms that result in optimal solutions that violate certain security operational constraints. To this end, this paper presents an adaptive constraint differential evolution (ACDE) algorithm, in which the novelty lies primarily in these three points: i) the crossover rate (CR) sorting mechanism is employed to build the relationship of CR and individual fitness values; ii) reusing successful evolution direction is proposed to guide the individual evolution towards promising regions; iii) an advanced constraint handling technique named superiority of feasible solutions (SF) is introduced to effectively deal with constraints in power systems. In order to verify the performance of the presented approach to the OPF problem, the standard IEEE-30 bus system is selected as the test case, in which six optimization objectives including total fuel cost, total fuel cost considering the valve-point effect, real active power losses, voltage deviation, voltage stability and emission are studied. The experimental results demonstrate that the presented approach can provide the smaller cost (800.41132$/h), reducing by up to 3.76% compared to the MPIO-COSR. In terms of the emission, ACDE emits the least emissions (0.204817ton/h). In addition, the proposed method also obtains the best results on the real active power losses (3.084041 MW) and voltage deviation (0.085636p.u.) when compared with other state-of-the-art methods.