VeraSel: Verifiable Random Selection for Mixnets Construction

The security and performance of Mixnets depends on the trustworthiness of the Mixnodes in the network. The challenge is to limit the adversary's influence on which Mixnodes operate in the network. A trusted party (such as the Mixnet operator) may ensure this, however, it is a single point of failure in the event of corruption or coercion. Therefore, we study the problem of how to select a subset of Mixnodes in a distributed way for Mixnet construction. We present VeraSel, a scheme that enables Mixnodes to be chosen according to their weights in a distributed, unbiased, and verifiable fashion using Verifiable Random Functions (VRFs). It is shown that VeraSel enables any party to learn and verify which nodes has been selected based on the commitments and proofs generated by each Mixnode with VRF

Stopping Silent Sneaks: Defending against Malicious Mixes with Topological Engineering

Mixnets provide strong meta-data privacy and recent academic research and industrial projects have made strides in making them more secure, performance, and scalable. In this paper, we focus our work on stratified Mixnets -- a popular design with real-world adoption -- and identify that there still exist heretofore inadequately explored practical aspects such as: relay sampling and topology placement, network churn, and risks due to real-world usage patterns. We show that, due to the lack of incorporating these aspects, Mixnets of this type are far more susceptible to user deanonymization than expected. In order to reason and resolve these issues, we model Mixnets as a three-stage ``Sample-Placement-Forward'' pipeline, and using the results of our evaluation propose a novel Mixnet design, Bow-Tie. Bow-Tie mitigates user deanonymization through a novel adaption of Tor's guard design with an engineered guard layer and client guard-logic for stratified mixnets. We show that Bow-Tie has significantly higher user anonymity in the dynamic setting, where the Mixnet is used over a period of time, and is no worse in the static setting, where the user only sends a single message. We show the necessity of both the guard layer and client guard-logic in tandem as well as their individual effect when incorporated into other reference designs. Ultimately, Bow-Tie is a significant step towards addressing the gap between the design of Mixnets and practical deployment and wider adoption because it directly addresses real-world user and Mixnet operator concerns

Identification of Vascular and Hematopoietic Genes Downstream of etsrp by Deep Sequencing in Zebrafish

The transcription factor etsrp/Er71/Etv2 is a master control gene for vasculogenesis in all species studied to date. It is also required for hematopoiesis in zebrafish and mice. Several novel genes expressed in vasculature have been identified through transcriptional profiling of zebrafish embryos overexpressing etsrp by microarrays. Here we re-examined this transcriptional profile by Illumina RNA-sequencing technology, revealing a substantially increased number of candidate genes regulated by etsrp. Expression studies of 50 selected candidate genes from this dataset resulted in the identification of 39 new genes that are expressed in vascular cells. Regulation of these genes by etsrp was confirmed by their ectopic induction in etsrp overexpressing and decreased expression in etsrp deficient embryos. Our studies demonstrate the effectiveness of the RNA-sequencing technology to identify biologically relevant genes in zebrfish and produced a comprehensive profile of genes previously unexplored in vascular endothelial cell biology

Intronic splicing enhancers, cognate splicing factors and context-dependent regulation rules

SummaryMost human genes produce multiple splicing isoforms with distinct functions. To systematically understand splicing regulation, we conducted an unbiased screen and identified >100 intronic splicing enhancers (ISEs) that were clustered by sequence similarity into six groups. All ISEs functioned in another cell type and heterologous introns, and their distribution and conservation patterns in different pre-mRNA regions are similar to exonic splicing silencers. Consistently all ISEs inhibited use of splice sites from exonic locations. The putative trans-factors of each ISE group were identified and validated. Five distinct ISE motifs were recognized by hnRNP H and F whose C-terminal domains were sufficient to render context-dependent activities of ISEs. The sixth group was controlled by factors that either activate or suppress splicing. This work provided a comprehensive picture of general ISE activities and provided new models of how a single element can function oppositely depending on its locations and binding factors

Association of Child Mental Health with Child and Family Characteristics in Rural China: A Cross-Sectional Analysis

Assessing the mental health problems encountered by school children and understanding the contributing factors are crucial to inform strategies aimed at improving mental health in low-resource contexts. However, few studies have investigated the mental health problems among disadvantaged children in poorer countries. This study examines the prevalence of mental health problems in rural China and their association with child and family characteristics. The study uses survey data from 9696 children in 120 rural primary schools and measures child mental health using the Strengths and Difficulties Questionnaire (SDQ). Overall, 17.9% of the sample children were found to be in the abnormal range of the SDQ total difficulties scores. The mean score was 12.93 (SD = 4.94). Abnormal scores were associated with child and family characteristics, including older child age (Odds Ratio, OR = 0.704, 95% CI: 0.611, 0.810; p < 0.001), gender (OR = 1.235, 95% CI: 1.112, 1.371; p < 0.001), and academic performance (OR = 0.421, 95% CI: 0.369, 0.480; p < 0.001). Reading time was found to be protective for mental health. Risk factors include excessive screen time (OR = 1.685, 95% CI: 1.409, 2.016; p < 0.001) and being bullied (OR = 3.695, 95% CI: 3.301, 4.136; p < 0.001). Our study suggests that future mental health illness prevention programs in rural China should consider targeting different aspects of children’s social contexts

Kinetic study of hydrolysis of xylan and agricultural wastes with hot liquid water

We investigated the kinetics of hot liquid water (HLW) hydrolysis over a 60-min period using a self-designed setup. The reaction was performed within the range 160-220 degrees C, under reaction conditions of 4.0 MPa, a 1:20 solid:liquid ratio (g/mL), at 500 rpm stirring speed. Xylan was chosen as a model compound for hemicelluloses, and two kinds of agricultural wastes-rice straw and palm shell-were used as typical feedstocks representative of herbaceous and woody biomasses, respectively. The hydrolysis reactions for the three kinds of materials followed a first-order sequential kinetic model, and the hydrolysis activation energies were 65.58 kJ/mol for xylan, 68.76 kJ/mol for rice straw, and 95.19 kJ/mol for palm shell. The activation energies of sugar degradation were 147.21 kJ/mol for xylan, 47.08 kJ/mol for rice straw and 79.74 kJ/mol for palm shell. These differences may be due to differences in the composition and construction of the three kinds of materials. In order to reduce the decomposition of sugars, the hydrolysis time of biomasses such as rice straw and palm shell should be strictly controlled. (C) 2009 Elsevier Inc. All rights reserved

Seawater carbonate chemistry and growth, net photosynthesis rate, Chlorophyll fluorescence parameter, soluble protein, photosynthetic pigments of red algae Pyropia yezoensis

Increasing CO2 levels in the surface water of oceans are expected to decrease oceanic pH and lead to seawater acidification. The responses of macroalgaea to this acidification of coastal waters have been studied in detail; however, most reports have focused on the adult stage only, while ignoring other life cycle stages. In this study, the economically important seaweed species Pyropia yezoensis was cultured under two CO2 concentrations (ambient CO2: 400 μatm; elevated CO2: 1000 μatm) and two light intensities (low light intensity: 80 μmol photons/m**2 /s; and high light intensity: 240 μmol photons/m**2 /s). The effects on the growth and photosynthetic performance of P. yezoensis were explored at different life cycle stages. Relative growth rates were significantly elevated at the conchocelis stage under high light intensity and elevated CO2 concentration. Moreover, the Pmax of P. yezoensis was also increased under high light intensity. However, this positive effect inversed at the thallus stage. The relative growth rate, relative electron transport rate (rETR), and net photosynthetic rate decreased at the thallus stage in response to high CO2 concentration. Under low light intensity, elevated CO2 concentration significantly increased the relative growth rates of conchocelis and thallus stages. These were 269% and 45% higher at elevated CO2 concentration compared with ambient CO2 concentrations, respectively. The Chl a and phycoerythrin levels were also higher under elevated CO2 level at the conchocelis stage. However, the rETR for the thallus stage was elevated under low light. This suggests that seawater acidification could positively affect algae at low light conditions (especially at the conchocelis stage). Different growth stages of P. yezoensis may respond differently to seawater acidification and changes of light intensity. Thalli growth stage, stocking density, and seawater depth should be considered in different areas to optimize the primary production of macroalgae