Competitive exploration of rectilinear polygons

Exploring a polygon with robots when the robots do not have knowledge of the surroundings can be viewed as an online problem. Typical for online problems is that decisions must be made based on past events without complete information about the future. In our case the robots do not have complete information about the environment. Competitive analysis can be used to measure the performance of methods solving online problems. The competitive ratio of such a method is the ratio between the method's performance and the performance of the best method having full knowledge of the future. We prove constant competitive strategies and lower bounds for exploring a simple rectilinear polygon in the _L1$L_1$ metric.     

基于服务器-客户端的数据库系统的数据混合加密

数据库系统安全是构建信息管理系统的关键；在公钥密码系统的基础上，利用混沌映射产生的密码流对基于C／S结构的数据库数据进行加密，实现了每一个需要加密的记录对应一个密码的功能，极大地提高了数据库系统的可靠性；算法已实现，实践和理论分析表明，该算法具有很好的安全实用性。     

Antioxidant activity and profiles of common fruits in Singapore

Thirty-eight types of fruits commonly consumed in Singapore were systematically analysed for their hydrophilic oxygen radical absorbance capacity (H-ORAC), total phenolic content (TPC), ascorbic acid (AA) and various lipophilic antioxidants. Antioxidant composition and concentration varied widely across different fruits. Many of the tropical fruits tested were high in antioxidants. Amongst all fruits tested, sapodilla (Manilkara zapota) had the highest H-ORAC and TPC whilst guava had the highest AA per gram fresh weight. Papaya, red watermelon and cantaloupe had the highest β-cryptoxanthin, lycopene and β-carotene per gram fresh weight, respectively. On the other hand, durian and mangosteen were high in tocopherols and tocotrienols, respectively. Based on consumption data, Chinese Singaporeans appear to have a higher intake of carotenoids and tocopherols rich fruits compared to the US population. As fruits are a rich source of diverse antioxidants, efforts to promote consumption of a variety of fruits should be continued for public health benefits.     

Dietary exposure of the Belgian population to emulsifiers E481 (sodium stearoyl-2-lactylate) and E482 (calcium stearoyl-2-lactylate)

A dietary exposure assessment of food emulsifiers E481 (sodium stearoyl-2-lactylate) and E482 (calcium stearoyl-2-lactylate) in the Belgian population was performed. Nationally representative food consumption data from the Belgian National Food Consumption Surveys 2004 (BNFCS2004) and 2014 (BNFCS2014) were used for calculations. A conservative approach (combining individual food consumption data with the maximum permitted level (MPL) of foods (tier 2), was compared with more refined estimates (combining individual food consumption data with actual concentrations measured in food products available on the Belgian market (tier 3)). Estimated daily intakes were compared to the acceptable daily intake (ADI) of the stearoyl-2-lactylates. The results of tier 2 demonstrated that 92% of the children (3–9 years), 53% of the adolescents (10–17 years), 15% of the adults (18–64 years) and 26% of the elderly (64–98 years) had a potential intake higher than the ADI. When replacing the MPL with maximum analysed concentration levels in foods, daily intake estimates decreased dramatically. The estimated daily intake of the food emulsifiers was below the ADI for all age groups, except for a small percentage of children (1.9%) for which the intake exceeded the ADI. The main contributors to the exposure of E481 and E482 were bread, rolls and fine bakery wares.     

Ganglioside Composition Distinguishes Anaplastic Ganglioglioma Tumor Tissue from Peritumoral Brain Tissue: Complementary Mass Spectrometry and Thin-Layer Chromatography Evidence

Gangliosides serve as antitumor therapy targets and aberrations in their composition strongly correlate with tumor growth and invasiveness. Anaplastic ganglioglioma is a rare, poorly characterized, malignant neuronal–glial tumor type. We present the first comparative characterization of ganglioside composition in anaplastic ganglioglioma vs. peritumoral and healthy brain tissues by combining mass spectrometry and thin-layer chromatography. Anaplastic ganglioglioma ganglioside composition was highly distinguishable from both peritumoral and healthy tissue despite having five to six times lower total content. Ten out of twelve MS-identified ganglioside classes, defined by unique glycan residues, were represented by a large number and considerable abundance of individual species with different fatty acid residues (C16–C24) in ceramide portions. The major structurally identified class was tumor-associated GD3 (>50%) with 11 species; GD3 (d18:1/24:0) being the most abundant. The dominant sphingoid base residue in ganglioside ceramides was sphingosine (d18:1), followed by eicosasphingosine (d20:1). The peritumoral tissue ganglioside composition was estimated as normal. Specific ganglioside composition and large variability of ganglioside ceramide structures determined in anaplastic ganglioglioma demonstrate realistic ganglioside expression patterns and correspond to the profile of high-grade malignancy brain tumors.     

The Impact of Zeta Potential and Physicochemical Properties of TiO2‐Based Nanocomposites on Their Biological Activity

The aim of this research was to observe the relationship between zeta potential, morphology, surface area, porosity, chemical composition, and ecotoxicity of nanocomposite powders such as Au/TiO₂, Ag₂O/TiO₂, PdO/TiO₂, Ag/TiO₂/SiO₂, Ag/N(C)TiO₂, and SiO₂/TiO₂ from which Ag₂O/TiO₂, Ag/N(C)/TiO_2, and Ag/TiO₂/SiO₂ were exhibiting good antimicrobial properties. It was observed, that nanomaterials characterized by similar morphology and zeta potential revealed the similar toxic behavior. The samples of higher agglomeration and higher zeta potential, especially Ag/TiO₂/SiO₂ xerogel and TiO₂/SiO₂ aerogel were generally less ecotoxic to water organisms and plants. They were also not genotoxic in concentrations up to 500 and 250 mg/L, respectively.     

Field Performance of High Oleic Soybeans with Mutant FAD2-1A and FAD2-1B Genes in Tennessee

Soybean [Glycine max (L.) Merr.] oil with high oleic acid (>75%) has increased oxidative stability and health benefits that are valuable for food, fuel, and industrial products. It has been determined that two naturally occurring mutations in genes FAD2-1A and FAD2-1B can combine to produce high oleic soybeans. The objective of this study was to test the effect of these mutant alleles on seed yield and oil and protein concentration. Molecular markers assisted in the creation of a population of 48 BC₃F_2:4 lines (93.75% expected genome commonality). Each line was classified into one of four genotypic groups where both FAD2-1A and FAD2-1B genes were either homozygous wild type or mutant, respectively. Twelve lines for each genotypic group were evaluated in three replications at six locations across Tennessee. There was no seed yield difference between the high oleic genotypic group and the other groups (P < 0.05). On the other hand, there were differences in fatty acid profiles and oil and protein concentrations. In combination, the mutant FAD2-1A and FAD2-1B alleles produced a mean of 803.1 g kg⁻¹ oleic acid. This is, on average, approximately 500 g kg⁻¹ more oleic acid compared to soybean lines with only one mutant FAD2-1 allele. The high oleic double mutant group had more total oil (228.0 g kg⁻¹) and protein (401.0 g kg⁻¹) compared to all other genotypic groups (P < 0.05). Overall, this specific combination of mutant FAD2-1A and FAD2-1B alleles appears to generate conventional high oleic soybeans without a yield drag.     

Influence of high power ultrasound on physical–chemical properties of polypropylene films aimed for food packaging: barrier and contact angle features

Investigation was focused on the impact of high power ultrasound (HPUS), also called thermosonication, on the oxygen permeation properties (permeability, solubility and diffusion coefficients) of barrier films aimed for food packaging. For this purpose, biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) were used. The physical–chemical profile of the samples was determined using goniometry. There is a significant impact only of extreme HPUS conditions (the longest time and the highest amplitude) on the permeability, solubility and diffusion coefficients of oxygen through the BOPP films. The highest influence on the oxygen permeability in both investigated BOPP samples involved an HPUS with an amplitude of 100% during a 6 min treatment. However, BOPP samples showed different sensitivities at lower HPUS treatments. © 2017 Society of Chemical Industry     

A systematic comparison of PCA‐based Statistical Process Monitoring methods for high‐dimensional,time‐dependent Processes

High‐dimensional and time‐dependent data pose significant challenges to Statistical Process Monitoring. Most of the high‐dimensional methodologies to cope with these challenges rely on some form of Principal Component Analysis (PCA) model, usually classified as nonadaptive and adaptive. Nonadaptive methods include the static PCA approach and Dynamic Principal Component Analysis (DPCA) for data with autocorrelation. Methods, such as DPCA with Decorrelated Residuals, extend DPCA to further reduce the effects of autocorrelation and cross‐correlation on the monitoring statistics. Recursive Principal Component Analysis and Moving Window Principal Component Analysis, developed for nonstationary data, are adaptive. These fundamental methods will be systematically compared on high‐dimensional, time‐dependent processes (including the Tennessee Eastman benchmark process) to provide practitioners with guidelines for appropriate monitoring strategies and a sense of how they can be expected to perform. The selection of parameter values for the different methods is also discussed. Finally, the relevant challenges of modeling time‐dependent data are discussed, and areas of possible further research are highlighted. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1478–1493, 2016