Learning the hub graphical Lasso model with the structured sparsity via an efficient algorithm

Graphical models have exhibited their performance in numerous tasks ranging from biological analysis to recommender systems. However, graphical models with hub nodes are computationally difficult to fit, particularly when the dimension of the data is large. To efficiently estimate the hub graphical models, we introduce a two-phase algorithm. The proposed algorithm first generates a good initial point via a dual alternating direction method of multipliers (ADMM), and then warm starts a semismooth Newton (SSN) based augmented Lagrangian method (ALM) to compute a solution that is accurate enough for practical tasks. The sparsity structure of the generalized Jacobian ensures that the algorithm can obtain a nice solution very efficiently. Comprehensive experiments on both synthetic data and real data show that it obviously outperforms the existing state-of-the-art algorithms. In particular, in some high dimensional tasks, it can save more than 70\% of the execution time, meanwhile still achieves a high-quality estimation.Comment: 28 pages,3 figure

Ontology based cooperative intrusion detection system

Abstract. As malicious intrusions span sites more frequently, network security plays the vital role in internet. Intrusion detection system(IDS) is expected to provide powerful protection against malicious behaviors. However, high false negative and false positive prevent intrusion detection system from practically using. After survey of present intrusion detection systems, we believe more accurate and efficient detection result can be obtained by using multi-sensor cooperative detection. To aiding cooperative detection, an ontology consisting of attribute nodes and value nodes is presented after analysis of IDSs rules and various classes of computer intrusions. On the basis of ontology, a matchmaking method is given to improve flexibility of detection. Cooperative detection framework based on the ontology is also discussed. The ontology proposed in paper has two advantages. First, it makes the detection more flexible and second it provides global locality information to support cooperation

IRX3 plays an important role in the pathogenesis of metabolic-associated fatty liver disease by regulating hepatic lipid metabolism

Metabolic-associated fatty liver disease (MAFLD) affects approximately a quarter of the global population. Identification of the key genes and pathways involved in hepatic lipid metabolism is of the utmost importance for the diagnosis, treatment, and prevention of MAFLD. In this study, differentially expressed genes were identified through whole-genome transcriptional analysis of liver tissue from MAFLD patients and healthy controls, and a series of lipid metabolism-related molecules and pathways were obtained through pathway analysis. Subsequently, we focused on Iroquois homeobox protein 3 (IRX3), one of 13 transcription factors that were screened from the 331 differentially expressed genes. The transcription factor IRX3 was significantly decreased in the liver tissue of patients with MAFLD when compared with healthy controls. Pearson’s correlation analysis showed that the expression levels of IRX3 in liver tissue were negatively correlated with serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and uric acid levels. The overexpression and interference of IRX3 induced the increased and decreased lipid droplet accumulation in vitro, respectively. Moreover, interference of IRX3 expression increased mitochondrial fragmentation and reduced the activity of the mitochondrial respiratory chain complex IV. In summary, the study demonstrated that IRX3 regulated hepatic lipid metabolism of MAFLD, and also revealed the effect of IRX3 on mitochondria might be an important mechanism by which IRX3 regulated hepatic lipid metabolism of MAFLD

Polyoxometalate catalysts with co-substituted VO2+ and transition metals and their catalytic performance for the oxidation of isobutane

Cs-Salts of the Keggin-type phosphomolybdic acid with simultaneous doping of VO2+ and different transition metals are prepared, characterized and tested as catalysts for the oxidation of isobutane to methacrylic acid under isobutane-rich conditions. The results show that Cs2.0V0.3Cu0.2PMo12O40 catalyst with co-substituted VO2+ and Cu2+ in its secondary structure exhibits higher catalytic performance than those with co-doped VO2+ and other transition metals such as Fe, Ni and Ce. This difference is ascribed to the synergistic effect between Cu2+ and VO2+ only in the secondary structure. This synergistic effect is related to the charge transfer between Mo6+ in the Keggin anions and Cu2+ counter cation, which promotes the re-oxidation of the catalyst and consequently its catalytic activity

Yunnan’s Fast-Paced Large Hydropower Development: A Powershed-Based Approach to Critically Assessing Generation and Consumption Paradigms

Southwest China’s Yunnan province is evolving into one of the world’s largest hydro-power-producing regions. It already rivals the world’s largest hydro-producing nations. However, five of Yunnan’s six basins are international and therefore its hydropower development is of great academic and geopolitical interest. While the implementation of large projects on Yunnan’s three large rivers (Jinsha, Mekong and Nu) is relatively well studied, hydropower development outside these three main streams is hardly known. Here, we identified 128 large hydropower projects (≥50 MW) having a capacity of 16.5 GW, along with another 16.4 GW of other types of power generation, neither of which has been discussed in the academic literature yet. The paper utilizes a powershed approach to study the rapid hydropower development underway in Yunnan, both in its implication and challenges (at basin and administrative level) as well as in its trade-offs within the broader electricity context. Yunnan’s power generation and consumption patterns are characterized by diverging interests of local/provincial usage and export utilization. Within the province, the largest (hydro-) power users are energy/electricity intensive industries, which themselves have strong impacts on land use changes. Yunnan is also evolving as a major power exporter, already in 2013 exporting about one-third of its generated electricity mainly to Guangdong’s Pearl River Delta. We see a need for a critical revision of those existing generation and consumption paradigms, which includes a rethinking of major development modes, both in terms of future hydropower generation and utilization projects as well as export obligations

Effect of V-containing precursors on the structure and catalytic performance of Cs-substituted phosphomolybdates for isobutane oxidation

A series of vanadium-substituted Cs salt of heteropoly compounds (HPC) from different vanadium-containing precursors were synthesized to investigate the preferable vanadyl species for oxidation of isobutane to methacrylic acid (MAA) under oxygen-poor conditions. The effects of various precursors on the structure were explored by XRD, FT-IR, Raman, UV-vis diffuse reflectance, XPS, H-2-TPR, NH3-TPD and IR spectra of pyridine adsorption, and their structure-performance relationship was further studied. It was firstly found that the vanadium-containing precursors played a crucial role in the structure (location of vanadyl species), surface acidity and redox properties (ratio of surface V4+/V5+ and Mos(5+)/Mo6+ redox couples) for series of as-prepared HPCs catalysts. The catalyst derived from vanadyl sulfate led to vanadyl species into the secondary structure of Keggintype HPC, which exhibited suitable surface V4+/V5+ and Mo5+/Mo6+ ratio and higher surface acidity, thereby improving the catalytic activity and selectivity to MAA for selective oxidation of isobutane under oxygen-poor conditions. These understandings would be beneficial for further study of HPCs and developing of highly efficient catalysts for isobutane oxidation

Water Cooperation Priorities in the Lancang-Mekong River Basin Based on Cooperative Events Since the Mekong River Commission Establishment

The Lancang-Mekong River has attracted much attention from researchers, but the cooperation on water issues in this river basin has been limited, even after the establishment of the Mekong River Commission (MRC). Cooperation on water resources has been determined as one of the key priority areas in the Lancang-Mekong Cooperation Mechanism, but there are no details of targets. In order to establish the priorities of water cooperation under the mechanism, we adopted nine categories to classify the objectives of 87 water cooperation events based on the ‘Lancang-Mekong Water Cooperative Events Database’ from 1995 to 2015. Based on the occurrence of cooperative events, cooperative objectives, cooperative scales, and approaches to cooperation, we conducted statistical, correlation, and text analyses. Our analyses indicated the following results: under the impact of economic conditions inside and outside the river basin, full cooperation appeared more difficult than bilateral and multilateral cooperation. Each of the partners adopted different preferences for cooperation targets. Cooperation with more definite objectives was easier to establish than cooperation with broader and more complex objectives. The potential objectives for water cooperation were navigation, hydropower, joint management, data sharing, flood control and water use. Because hydropower development is controversial, and because water cooperation is avoided by most existing regional cooperation mechanisms due to its complexity, we suggest the following priority areas for water cooperation in the Lancang- Mekong River Basin. 1) Navigation and flood control/drought relief are attractive objectives for all the riparian countries across the whole watershed. 2) Data sharing should be a priority for cooperation in the watershed due to its laying the foundation for the equitable and reasonable utilization of transboundary waters. 3) Hydropower is an objective best implemented mainly through bilateral cooperation, and on tributaries

Revising China's Environmental Law

China's Environmental Protection Law (EPL) is the main national environmental legislative framework. Yet the environmental legal system is incomplete, and implementation and enforcement of environmental laws have shown major shortcomings (1–3). A controversial attempt to revise the EPL could have far-reaching impacts on China's economic development and environmental protection, which may have global implications (4, 5). Increasing pressures to strengthen the rule of law in China raise the stakes (6). We discuss the need for a sound legal and scientific basis for revising the EPL