100 research outputs found
COIN: Co-Cluster Infomax for Bipartite Graphs
Bipartite graphs are powerful data structures to model interactions between
two types of nodes, which have been used in a variety of applications, such as
recommender systems, information retrieval, and drug discovery. A fundamental
challenge for bipartite graphs is how to learn informative node embeddings.
Despite the success of recent self-supervised learning methods on bipartite
graphs, their objectives are discriminating instance-wise positive and negative
node pairs, which could contain cluster-level errors. In this paper, we
introduce a novel co-cluster infomax (COIN) framework, which captures the
cluster-level information by maximizing the mutual information of co-clusters.
Different from previous infomax methods which estimate mutual information by
neural networks, COIN could easily calculate mutual information. Besides, COIN
is an end-to-end coclustering method which can be trained jointly with other
objective functions and optimized via back-propagation. Furthermore, we also
provide theoretical analysis for COIN. We theoretically prove that COIN is able
to effectively increase the mutual information of node embeddings and COIN is
upper-bounded by the prior distributions of nodes. We extensively evaluate the
proposed COIN framework on various benchmark datasets and tasks to demonstrate
the effectiveness of COIN.Comment: NeurIPS 2022 GLFrontiers Worksho
Application of citrate as a tricarboxylic acid (TCA) cycle intermediate, prevents diabetic-induced heart damages in mice
Objective(s):Higher cellular reactive oxygen species (ROS) levels is important in reducing cellular energy charge (EC) by increasing the levels of key metabolic protein, and nitrosative modifications, and have been shown to damage the cardiac tissue of diabetic mice. However, the relation between energy production and heart function is unclear.
Materials and Methods:Streptozotocin (STZ, 150 mg/kg body weight) was injected intraperitoneally once to mice that had been fasted overnight for induction of diabetes. After diabetic induction, mice received citrate (5 µg/kg) through intraperitoneal injection every other day for 5 weeks. The caspase-3, plasminogen activator inhibitor 1 (PAI1), protein kinase B (PKB), commonly known as AKT and phosphorylated-AKT (p-AKT) proteins were examined to elucidate inflammation and apoptosis in the heart. For histological analysis, heart samples were fixed with 10% formalin and stained with hematoxylin-eosin (HE) and Sirius red to assess pathological changes and fibrosis. The expression levels[AGA1] of marker proteins, tyrosine nitration, activity of ATP synthase and succinyl-CoA:3-ketoacid coenzyme A transferase-1 (SCOT), and EC were measured.
Results:Intraperitoneal injection of citrate significantly reduced caspase-3 and PAI-1 protein levels and increased p-AKT level on the 5th week; EC in the heart was found to be increased as well. Further, the expression level, activity, and tyrosine nitration of ATP synthase and SCOT were not affected after induction of diabetes.
Conclusion: Results indicate that application of citrate, a tricarboxylic acid (TCA) cycle intermediate, might alleviate cardiac dysfunction by reducing cardiac inflammation, apoptosis, and increasing cardiac EC
Dynamic Modeling and Vibration Analysis for the Vehicles with Rigid Wheels Based on Wheel-Terrain Interaction Mechanics
The contact mechanics for a rigid wheel and deformable terrain are complicated owing to the rigid flexible coupling characteristics. Bekker's equations are used as the basis to establish the equations of the sinking rolling wheel, to vertical load pressure relationship. Since vehicle movement on the Moon is a complex and on-going problem, the researcher is poised to simplify this problem of vertical loading of the wheel. In this paper, the quarter kinetic models of a manned lunar rover, which are both based on the rigid road and deformable lunar terrain, are used as the simulation models. With these kinetic models, the vibration simulations were conducted. The simulation results indicate that the quarter kinetic model based on the deformable lunar terrain accurately reflects the deformable terrain's influence on the vibration characteristics of a manned lunar rover. Additionally, with the quarter kinetic model of the deformable terrain, the vibration simulations of a manned lunar rover were conducted, which include a parametric analysis of the wheel parameters, vehicle speed, and suspension parameters. The results show that a manned lunar rover requires a lower damping value and stiffness to achieve better vibration performance
Consumption of sugar sweetened beverages, artificially sweetened beverages and fruit juices and risk of type 2 diabetes, hypertension, cardiovascular disease, and mortality: A meta-analysis
Introduction:
Sugar-sweetened beverage (SSB) intake is associated with an increased risk of cardiometabolic diseases. However, evidence regarding associations of artificially sweetened beverages (ASBs) and fruit juices with cardiometabolic diseases is mixed. In this study, we aimed to investigate the association between the SSB, ASB and fruit juice consumption with the incidence of cardiometabolic conditions and mortality.
Methods:
Relevant prospective studies were identified by searching PubMed, Web of Science, Embase, and Cochrane Library until December 2022 without language restrictions. The pooled relative risk (RR) and 95% confidence intervals (CIs) were estimated for the association of SSBs, ASBs, and fruit juices with the risk of type 2 diabetes (T2D), cardiovascular disease (CVD), and mortality by using random-effect models.
Results:
A total of 72 articles were included in this meta-analysis study. Significantly positive associations were observed between the consumption of individual beverages and T2D risk (RR: 1.27; 95% CI: 1.17, 1.38 for SSBs; RR: 1.32; 95% CI: 1.11, 1.56 for ASBs; and RR:0.98; 95% CI: 0.93, 1.03 for fruit juices). Moreover, our findings showed that intakes of SSBs and ASBs were significantly associated with risk of hypertension, stroke, and all-cause mortality (RR ranging from 1.08 to 1.54; all p < 0.05). A dose-response meta-analysis showed monotonic associations between SSB intake and hypertension, T2D, coronary heart disease (CHD), stroke and mortality, and the linear association was only significant between ASB consumption and hypertension risk. Higher SSB and ASB consumptions were associated with a greater risk of developing cardiometabolic diseases and mortality. Fruit juice intake was associated with a higher risk of T2D.
Conclusion:
Therefore, our findings suggest that neither ASBs nor fruit juices could be considered as healthier beverages alternative to SSBs for achieving improved health.
Systematic Review Registration:
[PROSPERO], identifier [No. CRD42022307003]
Development of a PNA Probe for Fluorescence In Situ Hybridization Detection of Prorocentrum donghaiense
Prorocentrum donghaiense is a common but dominant harmful algal bloom (HAB) species, which is widely distributed along the China Sea coast. Development of methods for rapid and precise identification and quantification is prerequisite for early-stage warning and monitoring of blooms due to P. donghaiense. In this study, sequences representing the partial large subunit rDNA (D1–D2), small subunit rDNA and internal transcribed spacer region (ITS-1, 5.8S rDNA and ITS-2) of P. donghaiense were firstly obtained, and then seven candidate DNA probes were designed for performing fluorescence in situ hybridization (FISH) tests on P. donghaiense. Based on the fluorescent intensity of P. donghaiense cells labeled by the DNA probes, the probe DP0443A displayed the best hybridization performance. Therefore, a PNA probe (PP0443A) analogous to DP0443A was used in the further study. The cells labeled with the PNA probe displayed more intensive green fluorescence than that labeled with its DNA analog. The PNA probe was used to hybridize with thirteen microalgae belonging to five families, i.e., Dinophyceae, Prymnesiophyceae, Raphidophyceae, Chlorophyceae and Bacillariophyceae, and showed no visible cross-reaction. Finally, FISH with the probes PP0443A and DP0443A and light microscopy (LM) analysis aiming at enumerating P. donghaiense cells were performed on the field samples. Statistical comparisons of the cell densities (cells/L) of P. donghaiense in the natural samples determined by FISH and LM were performed using one-way ANOVA and Duncan's multiple comparisons of the means. The P. donghaiense cell densities determined by LM and the PNA probe are remarkably higher than (p<0.05) that determined by the DNA probe, while no significant difference is observed between LM and the PNA probe. All results suggest that the PNA probe is more sensitive that its DNA analog, and therefore is promising for the monitoring of harmful algal blooms of P. donghaiense in the future
The oyster genome reveals stress adaptation and complexity of shell formation
The Pacific oyster Crassostrea gigas belongs to one of the most species-rich but genomically poorly explored phyla, the Mollusca. Here we report the sequencing and assembly of the oyster genome using short reads and a fosmid-pooling strategy, along with transcriptomes of development and stress response and the proteome of the shell. The oyster genome is highly polymorphic and rich in repetitive sequences, with some transposable elements still actively shaping variation. Transcriptome studies reveal an extensive set of genes responding to environmental stress. The expansion of genes coding for heat shock protein 70 and inhibitors of apoptosis is probably central to the oyster's adaptation to sessile life in the highly stressful intertidal zone. Our analyses also show that shell formation in molluscs is more complex than currently understood and involves extensive participation of cells and their exosomes. The oyster genome sequence fills a void in our understanding of the Lophotrochozoa. © 2012 Macmillan Publishers Limited. All rights reserved
Multi-Criterion Spatial Optimization of Future Police Stations Based on Urban Expansion and Criminal Behavior Characteristics
Lanzhou’s rapid development has raised new security challenges, and improving public safety in areas under the jurisdiction of police stations is an effective way to address the problem of public security in urban areas. Unfortunately, the existing studies do not consider how factors such as future land changes, building functions, and characteristics of criminal behavior influence the choice of areas for police stations and the optimization of police stations with respect to traffic congestion. To solve these problems, we apply multiple methods and multi-source geospatial data to optimize police station locations. The proposed method incorporates a big data perspective, which provides new ideas and technical approaches to site selection models. First, we use the central city of Lanzhou as the study area and erase the exclusion areas from the initial layer to identify the undeveloped areas. Second, historical crime data, point of interest, and other data are combined to assess the potential crime risk. We then use the analytic hierarchy process to comprehensively assess undeveloped areas based on potential crime hotspots and on socioeconomic drivers and orography. In addition, according to China’s Road Traffic Safety Law and the current traffic congestion in the city, a minimum speed is determined, so that the target area can be reached in time even in congested traffic. Finally, we draw the spatial coverage map of police stations based on the location-allocation model and network analysis and optimize the map by considering the coverage rate of high-risk areas and building construction, in addition to maintenance and other objectives. The result shows that crime concentrates mainly in densely populated areas, indicating that people and wealth are the main drivers of crime. The differences in the spatial distribution of crime hotspots and residential areas at different spatial scales mean that the ratio of public security police force to household police force allocated to different police stations is spatially nonuniform. The method proposed herein reduces the overlap of police station service areas by 22.8% and increases the area coverage (12.01%) and demand point coverage (7.25%). The area coverage means an area potentially accessible within five minutes, and point coverage implies an effective drive. Within reasonable optimization, this allows us to eventually remove 13 existing police stations and add 24 candidate police stations
Research on ultrasonic vibration grinding technology of SiCp/Al composites
In view of the difficulties in processing SiCp/Al materials by traditional grinding methods, the rapid wear of grinding tools, and the difficulties in obtaining high surface quality after processing, the ultrasonic vibration grinding method can significantly improve the processing effect. By analyzing the ultrasonic vibration trajectory of a single abrasive particle, it is concluded that its movement trajectory is a space ellipse shape, which can realize intermittent contact processing between the abrasive particle and the workpiece. The ultrasonic vibration grinding test is carried out on the SiCp/Al material with a volume fraction of 40% by using a resin-bonded diamond grinding head. Under different spindle speeds n, feed rates v, grinding depths ap and abrasive particle sizes d, the single-factor test method is used to detecte surface roughness of the workpiece. How each process parameter influences the Sa value of the workpiece surface roughness is obtained. And it is verified that ultrasonic vibration grinding of SiCp/Al can effectively improve the surface quality. The surface roughness of workpiece after ultrasonic vibration grinding decreases to 45 nm compared with 79 nm after ordinary grinding. The surface roughness of the workpiece first decreases and then increases with the increase of n, and it is the smallest when the speed is 1 800 r/min. The surface roughness of the workpiece increases with the increase of v and ap, and decreases with the decrease of d. And the optimal parameter combination in the test parameters is obtained: n=1 800 r/min, v=5 mm/min, ap=1 μm, d=4.5 μm
Effect of coagulants categories on the fouling and performance of ultrafiltration (UF) membrane
The combined coagulation and ultrafiltration (UF) system (C-UF system) is an advanced technology to treat natural organic matter (NOM) present in water. Traditional coagulants—prehydrolyzed inorganic coagulants, organic coagulants and composite coagulants were chosen to treat synthetic water containing humic acid (HA) in order to find an efficient coagulant that could remove NOM from the water effectively. The fouling, removal efficiency of UF and the chlorine decay in the permeate were used to evaluate the effectiveness of the coagulants. The initial UV254 absorption of the tested water samples were from 0.208 to 0.234, and the UV254 after coagulation was from 0.05 to 0.184. The UV254 did not increase after coagulation. Since the humic acid used was soluble, the initial turbidity of the tested water samples were very close to zero. The turbidity increased after coagulation, as the coagulants react with humic acid to form micro-flocs, which cannot be removed fully by sedimentation. The results showed that Polyferric chloride could not remove humic acid efficiently during coagulation process, but removed the humic acid well when used in the C-UF system. Moreover, for polyferric chloride and UF system, the concentration of organic compounds in permeates were minimal indicating very low levels of disinfection by-product formation, if chlorinated
Effect of coagulants on the fouling and performance of ultrafiltration (UF) membranes
The combined coagulation and ultrafiltration (UF) system (C-UF system) is an advanced technology to treat natural organic matter (NOM) present in water. Traditional coagulants — prehydrolyzed inorganic coagulants, organic coagulants and composite coagulants were chosen to treat synthetic water containing humic acid (HA) in order to find an efficient coagulant that could remove NOM from the water effectively. The fouling, removal efficiency of UF and the chlorine decay in the permeate were used to evaluate the effectiveness of the coagulants. The initial UV254 absorption of the tested water samples were from 0.208 to 0.234, and the UV254 after coagulation was from 0.05 to 0.184. The UV254 did not increase after coagulation. Since the humic acid used was soluble, the initial turbidity of the tested water samples were very close to zero. The turbidity increased after coagulation, as the coagulants react with humic acid to form micro-flocs, which cannot be removed fully by sedimentation. The results showed that polyferric chloride could not remove humic acid efficiently during coagulation process, but removed the humic acid well when used in the C-UF system. Moreover, for polyferric chloride and UF system, the concentration of organic compounds in permeates were minimal indicating very low levels of disinfection by-product formation, if chlorinated.<br /
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