Improved High-Probability Regret for Adversarial Bandits with Time-Varying Feedback Graphs

We study high-probability regret bounds for adversarial $K$-armed bandits with time-varying feedback graphs over $T$ rounds. For general strongly observable graphs, we develop an algorithm that achieves the optimal regret $\widetilde{\mathcal{O}}((\sum_{t=1}^T\alpha_t)^{1/2}+\max_{t\in[T]}\alpha_t)$ with high probability, where $\alpha_t$ is the independence number of the feedback graph at round $t$. Compared to the best existing result [Neu, 2015] which only considers graphs with self-loops for all nodes, our result not only holds more generally, but importantly also removes any $\text{poly}(K)$ dependence that can be prohibitively large for applications such as contextual bandits. Furthermore, we also develop the first algorithm that achieves the optimal high-probability regret bound for weakly observable graphs, which even improves the best expected regret bound of [Alon et al., 2015] by removing the $\mathcal{O}(\sqrt{KT})$ term with a refined analysis. Our algorithms are based on the online mirror descent framework, but importantly with an innovative combination of several techniques. Notably, while earlier works use optimistic biased loss estimators for achieving high-probability bounds, we find it important to use a pessimistic one for nodes without self-loop in a strongly observable graph

Job Satisfaction Among Methadone Maintenance Treatment Clinic Service Providers in Jiangsu, China: A Cross-sectional Survey.

ObjectiveService providers' job satisfaction is critical to the stability of the work force and thereby the effectiveness of methadone maintenance treatment (MMT) programs. This study aimed to explore MMT clinic service providers' job satisfaction and associated factors in Jiangsu, China.MethodsThis secondary study used baseline data of a randomized interventional trial implemented in Jiangsu, China. A survey was conducted among 76 MMT service providers using the computer-assisted self-interview (CASI) method. Job satisfaction responses were assessed via a 30-item scale, with a higher score indicating a higher level of job satisfaction. Perceived institutional support and perceived stigma due to working with drug users were measured using a 9-item scale. Correlation and multiple linear regression analyses were performed to identify factors associated with job satisfaction.ResultsCorrelation analyses found a significant association between job satisfaction and having professional experience in the prevention and control of HIV, other sexually transmitted infections, or other infectious diseases (P = 0.046). Multiple regression analyses revealed that working at MMT clinics affiliated with Center for Disease Control and Prevention sites was associated with a lower level of job satisfaction (P = 0.014), and perception of greater institutional support (P = 0.001) was associated with a higher level of job satisfaction.ConclusionJob satisfaction among MMT clinic service providers was moderate in our study. Our findings suggest that institutional support for providers should be improved, and that acquisition of additional expertise should be encouraged

Preparation and Characterization of Solid Electrolyte Doped With Carbon Nanotubes and its Preliminary Application in NO2 Gas Sensors

In this work, a solid polymer electrolyte (SPE) doped with carbon nanotubes (CNTs) was used as a gas sensing material for a NO2 gas sensor. The electrolytes consisted of the ionic liquids (ILs) and CNTs, which were immobilized in a poly(vinylidene fluoride) (PVDF) matrix. The SPE membranes were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and cyclic voltammetry (CV). The experimental results show that the addition of an appropriate amount of CNTs can appropriately improve the electrochemical performance of the SPE membrane. It was shown that NO2 gas sensors with an appropriate amount of CNTs added to their SPEs had a higher gas sensitivity than those with SPE containing no CNTs. When the mass ratio of PVDF, N-methyl-2-pyrrolidone (NMP), IL, and CNT was 1:4:1:0.08, the SPE showed the best gas sensitivity, and its sensitivity is 0.00275 V/ppm

OsbZIP18, a Positive Regulator of Serotonin Biosynthesis, Negatively Controls the UV-B Tolerance in Rice

Serotonin (5-hydroxytryptamine) plays an important role in many developmental processes and biotic/abiotic stress responses in plants. Although serotonin biosynthetic pathways in plants have been uncovered, knowledge of the mechanisms of serotonin accumulation is still limited, and no regulators have been identified to date. Here, we identified the basic leucine zipper transcription factor OsbZIP18 as a positive regulator of serotonin biosynthesis in rice. Overexpression of OsbZIP18 strongly induced the levels of serotonin and its early precursors (tryptophan and tryptamine), resulting in stunted growth and dark-brown phenotypes. A function analysis showed that OsbZIP18 activated serotonin biosynthesis genes (including tryptophan decarboxylase 1 (OsTDC1), tryptophan decarboxylase 3 (OsTDC3), and tryptamine 5-hydroxylase (OsT5H)) by directly binding to the ACE-containing or G-box cis-elements in their promoters. Furthermore, we demonstrated that OsbZIP18 is induced by UV-B stress, and experiments using UV-B radiation showed that transgenic plants overexpressing OsbZIP18 exhibited UV-B stress-sensitive phenotypes. Besides, exogenous serotonin significantly exacerbates UV-B stress of OsbZIP18_OE plants, suggesting that the excessive accumulation of serotonin may be responsible for the sensitivity of OsbZIP18_OE plants to UV-B stress. Overall, we identified a positive regulator of serotonin biosynthesis and demonstrated that UV-B-stress induced serotonin accumulation, partly in an OsbZIP18-dependent manner

Volcanism, redox conditions, and microbialite growth linked with the end-Permian mass extinction: Evidence from the Xiajiacao section (western Hubei Province), South China

© 2017. A new Permian-Triassic boundary microbialite (PTBM) is described from the Xiajiacao section of western Hubei Province, South China. The new microbialite, 3.16. m thick, comprises a thin layer of stromatolite and a thick thrombolite unit. An irregular contact separates the uppermost Permian skeletal packstone from the post-extinction stromatolite, but it is not yet possible to discriminate whether it was formed by submarine solution in the wake of ocean acidification or subaerial exposure due to regional regression, or a combination of both. The stromatolite shows "cabbage-like" morphology, and the thrombolite is characterized by centimetric clotted texture. Abundant columns of the microproblematica structure Gakhumella, coccoid-like spheroids, bacterial clump-like spheroids, and hollow spheroids are recognized in both stromatolites and thrombolites and may have played an important role in accretion of the microbialites. Pyrite framboid analysis indicates that microbialites may have been affected by lower dysoxic to upper dysoxic conditions in the immediate aftermath of the Permian-Triassic extinction. Stratigraphic abundance of both high-temperature grains (β-quartz and glassy balls) peaked ~. 20. cm below the biotic extinction horizon, implying that either intensive volcanic eruption occurred only just prior to biotic extinction, or volcanism was still intensive during biotic extinction, but volcanic grains were not deposited in the Xiajiacao locality, likely due to the shallow, agitated environment caused by the regional regression. Overall, microbial bloom, indicated by the widespread PTBMs, seems to have been little affected by the contemporaneous volcanism.We thank both anonymous reviewers and editor Thomas Algeo for critical comments and constructive suggestions, which have greatly improved the quality of the paper. This study is partly supported by the 111 Program of China (B08030), two NSFC grants (41572091, 41402089), and one research grant from the State Key Laboratory of Biogeology and Environmental Geology (BGEG), China University of Geosciences (GBL11206). It is a contribution to the IGCP 630 “Permian–Triassic climatic and environmental extremes and biotic response”

Combined effects of host genetics and diet on porcine intestinal fungi and their pathogenic genes

As research on gut microbes progresses, it becomes increasingly clear that a small family of microbiota--fungi, plays a crucial role in animal health. However, little is known about the fungal composition in the pig intestine, especially after a dietary fiber diet and hybrid genetics, and the changes in host pathogenicity-associated genes they carry. The purpose of this study is to investigate the effects of diet and genetics on the diversity and structure of porcine intestinal fungi and to describe, for the first time, the host pathogenicity-related genes carried by porcine intestinal fungi. Samples of colonic contents were collected for metagenomic analysis using a 3 × 2 parsing design, where three pig breeds (Taoyuan, Duroc, and crossbred Xiangcun) were fed high or low fiber diets (n = 10). In all samples, we identified a total of 281 identifiable fungal genera, with Ascomycota and Microsporidia being the most abundant fungi. Compared to Duroc pigs, Taoyuan and Xiangcun pigs had higher fungal richness. Interestingly, the fiber diet significantly reduced the abundance of the pathogenic fungus Mucor and significantly increased the abundance of the fiber digestion-associated fungus Neocallimastix. Pathogenic fungi exert their pathogenicity through the genes they carry that are associated with host pathogenicity. Therefore, we obtained 839 pathogenicity genes carried by the spectrum of fungi in the pig intestine by comparing the PHI-base database. Our results showed that fungi in the colon of Taoyuan pigs carried the highest abundance of different classes of host pathogenicity-related genes, and the lowest in Duroc pigs. Specifically, Taoyuan pigs carried high abundance of animal pathogenicity-related genes (CaTUP1, CPAR2_106400, CaCDC35, Tfp1, CaMNT2), and CaTUP1 was the key gene for Candida pathogenicity. The intestinal fungal composition of crossbred Xiangcun pigs and the abundance of host pathogenicity-associated genes they carried exhibited a mixture of characteristics of Taoyuan and Duroc pigs. In conclusion, our results provide the first comprehensive report on the effects of dietary fiber and genetics on the composition of intestinal fungi and the host-associated pathogenicity genes they carry in pigs. These findings provide a reference for subsequent pig breeding and development of anti-pathogenic fungal drugs