Optimal designs for asymmetric sigmoidal response curves in bioassays and immunoassays

Recent studies show that asymmetric sigmoidal response curves are not uncommonin biomedical studies. For example, the 5-parameter logistic (5PL) model isfrequently used to model and analyze responses from bioassays and immunoassayswhich can be skewed. Various types of optimal experimental designs for 2, 3 and4-parameter logistic models have been reported but not for the more complicated5-parameter logistic (5PL) model. Designs currently used for the 5PL model seemad-hoc with no formal quantitative assessment of their efficiencies. We constructdifferent types of optimal designs for studying various features of the 5PL modeland use them to evaluate efficiencies of commonly used designs in bioassays andimmunoassays. We also create a user-friendly software package to search for optimaldesigns tailor-made to user-specified problems for the 5PL model and evaluaterobustness properties of the design under a variation of criteria, model formsand mis-specification in the nominal values of the model parameters. Our designstrategies can also account for several objectives with varying degrees of importance.As an application, we generate optimal designs for the 5PL model for real studiesin immunoassays and bioassays, and show currently used designs are generallyinefficient for statistical inference

Genomic epidemiology of Vibrio cholerae reveals the regional and global spread of two epidemic non-toxigenic lineages

Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou between 2001 and 2012, and compared them with 850 publicly available global isolates. We found that CNTP isolates from Hangzhou belonged to two distinctive lineages, named L3b and L9. Both lineages caused disease over a long time period with usually mild or moderate clinical symptoms. Within Hangzhou, the spread route of the L3b lineage was apparently from rural to urban areas, with aquatic food products being the most likely medium. Both lineages had been previously reported as causing local endemic disease in Latin America, but here we show that global spread of them has occurred, with the most likely origin of L3b lineage being in Central Asia. The L3b lineage has spread to China on at least three occasions. Other spread events, including from China to Thailand and to Latin America were also observed. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies: surveillance of V. cholerae should not be limited to ctxAB positive strains

Dual KS: Defining Gene Sets with Tissue Set Enrichment Analysis

Background: Gene set enrichment analysis (GSEA) is an analytic approach which simultaneously reduces the dimensionality of microarray data and enables ready inference of the biological meaning of observed gene expression patterns. Here we invert the GSEA process to identify class-specific gene signatures. Because our approach uses the Kolmogorov-Smirnov approach both to define class specific signatures and to classify samples using those signatures, we have termed this methodology “Dual-KS” (DKS). Results: The optimum gene signature identified by the DKS algorithm was smaller than other methods to which it was compared in 5 out of 10 datasets. The estimated error rate of DKS using the optimum gene signature was smaller than the estimated error rate of the random forest method in 4 out of the 10 datasets, and was equivalent in two additional datasets. DKS performance relative to other benchmarked algorithms was similar to its performance relative to random forests. Conclusions: DKS is an efficient analytic methodology that can identify highly parsimonious gene signatures useful for classification in the context of microarray studies. The algorithm is available as the dualKS package for R as part of the bioconductor project

La\u3csub\u3e0.6\u3c/sub\u3eSr\u3csub\u3e1.4\u3c/sub\u3eMnO\u3csub\u3e4+δ\u3c/sub\u3e Layered Perovskite Oxide: Enhanced catalytic Activity for the Oxygen Reduction Reaction

Efficient electrocatalysts for the oxygen reduction reaction (ORR) is a critical factor to influence the performance of lithium–oxygen batteries. In this study, La0.6Sr1.4MnO4+δ layered perovskite oxide as a highly active electrocatalyst for the ORR has been prepared, and a carbon-coating layer with thickness \u3c5 nm has been successfully introduced to enhance the electronic conductivity of the as-prepared oxide. XRD, XPS, Raman, SEM and TEM measurements were carried out to characterize the crystalline structure and morphology of these samples. Rotating ring-disk electrode (RRDE) technique has been used to study catalytic activities of the as-prepared catalysts for the ORR in 0.1 M KOH media. RRDE results reveal that carbon-coated La0.6Sr1.4MnO4+δ exhibits better catalytic activity for the ORR. For the carbon-coated La0.6Sr1.4MnO4+δ, the ORR proceeds predominately via a direct four electron process, and a maximum cathodic current density of 6.70 mA cm−2 at 2500 rpm has been obtained, which is close to that of commercial Pt/C electrocatalyst under the same testing conditions

Strings And Colorings Of Topological Coding Towards Asymmetric Topology Cryptography

We, for anti-quantum computing, will discuss various number-based strings, such as number-based super-strings, parameterized strings, set-based strings, graph-based strings, integer-partitioned and integer-decomposed strings, Hanzi-based strings, as well as algebraic operations based on number-based strings. Moreover, we introduce number-based string-colorings, magic-constraint colorings, and vector-colorings and set-colorings related with strings. For the technique of encrypting the entire network at once, we propose graphic lattices related with number-based strings, Hanzi-graphic lattices, string groups, all-tree-graphic lattices. We study some topics of asymmetric topology cryptography, such as topological signatures, Key-pair graphs, Key-pair strings, one-encryption one-time and self-certification algorithms. Part of topological techniques and algorithms introduced here are closely related with NP-complete problems or NP-hard problems.Comment: Asymmetric topology encryption is a new topic of topological coding towards the certificateless public key cryptograph

VNM: An R Package for Finding Multiple-Objective Optimal Designs for the 4-Parameter Logistic Model

A multiple-objective optimal design is useful for dose-response studies because it can incorporate several objectives at the design stage. Objectives can be of varying interests and a properly constructed multiple-objective optimal design can provide user-specified efficiencies, delivering higher efficiencies for the more important objectives. In this work, we introduce the VNM package written in R for finding 3-objective locally optimal designs for the 4-parameter logistic (4PL) model widely used in education, bioscience and in the manufacturing industry. The package implements the methodology to construct multipleobjective optimal designs in Hyun and Wong (2015). As illustrative examples, we focus on a biomedical application where our objectives are to estimate: (1) the shape of the dose-response curve, (2) the median effective dose level (ED50) and (3) the minimum effective dose level (MED) in the 4PL model. Our VNM package uses a state-of-theart algorithm to generate multiple-objective optimal designs that meet the user-specified efficiency requirement for each objective, provides tools for calculating the efficiency of the generated design under each objective and also a plot for confirming optimality of the VNM-generated design. The package can also be used to determine an optimal scheme for allocating subjects to the various doses when the number and doses of the drug are fixed in advance

Mesoporous High‐Surface‐Area Copper–Tin Mixed‐Oxide Nanorods: Remarkable for Carbon Monoxide Oxidation

Mesoporous, high‐surface‐area Cu–Sn mixed‐oxide nanorods were fabricated for the first time by nanocasting with the use of mesoporous KIT‐6 silica as the hard template. The Cu–Sn nanorods are significantly more active than 1 % Pd/SnO2 for the oxidation of CO and possesses long‐term durability and potent water resistance; they thus have the potential to replace noble metal catalysts for emission‐control processes.In rod we trust: Mesoporous, high‐surface‐area Cu–Sn nanorods are successfully fabricated for the first time by nanocasting with the use of KIT‐6 silica as the hard template; these nanomaterials are significantly more active than 1 % Pd/SnO2 for the oxidation of CO, and furthermore, they have the potential to replace noble metal catalysts for emission control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/1/cctc201600221.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/2/cctc201600221-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137536/3/cctc201600221_am.pd