Threshold Dynamics of a Stochastic S

A stochastic SIR model with vertical transmission and vaccination is proposed and investigated in this paper. The threshold dynamics are explored when the noise is small. The conditions for the extinction or persistence of infectious diseases are deduced. Our results show that large noise can lead to the extinction of infectious diseases which is conducive to epidemic diseases control

A computational framework for complex disease stratification from multiple large-scale datasets.

BACKGROUND: Multilevel data integration is becoming a major area of research in systems biology. Within this area, multi-'omics datasets on complex diseases are becoming more readily available and there is a need to set standards and good practices for integrated analysis of biological, clinical and environmental data. We present a framework to plan and generate single and multi-'omics signatures of disease states. METHODS: The framework is divided into four major steps: dataset subsetting, feature filtering, 'omics-based clustering and biomarker identification. RESULTS: We illustrate the usefulness of this framework by identifying potential patient clusters based on integrated multi-'omics signatures in a publicly available ovarian cystadenocarcinoma dataset. The analysis generated a higher number of stable and clinically relevant clusters than previously reported, and enabled the generation of predictive models of patient outcomes. CONCLUSIONS: This framework will help health researchers plan and perform multi-'omics big data analyses to generate hypotheses and make sense of their rich, diverse and ever growing datasets, to enable implementation of translational P4 medicine

Roles of Genes 44, 50, and 51 in Regulating Gene Expression and Host Takeover during Infection of Bacillus subtilis by Bacteriophage SPO1

We show that the products of SPO1 genes 44, 50, and 51 are required for the normal transition from early to middle gene expression during infection of Bacillus subtilis by bacteriophage SPO1; that they are also required for control of the shutoff of host DNA, RNA, and protein synthesis; and that their effects on host shutoff could be accounted for by their effects on the regulation of gene expression. These three gene products had four distinguishable effects in regulating SPO1 gene expression: (i) gp44-50-51 acted to restrain expression of all SPO1 genes tested, (ii) gp44 and/or gp50-51 caused additional specific repression of immediate-early genes, (iii) gp44 and/or gp50-51 stimulated expression of middle genes, and (iv) gp44 and/or gp50-51 stimulated expression of some delayed-early genes. Shutoff of immediate-early gene expression also required the activity of gp28, the middle-gene-specific sigma factor. Shutoff of host RNA and protein synthesis was accelerated by either the 44(−) single mutant or the 50(−)51(−) double mutant and more so by the 44(−)50(−)51(−) triple mutant. Shutoff of host DNA synthesis was accelerated by the mutants early in infection but delayed by the 44(−)50(−)51(−) triple mutant at later times. Although gp50 is a very small protein, consisting almost entirely of an apparent membrane-spanning domain, it contributed significantly to each activity tested. We identify SPO1 genes 41 to 51 and 53 to 60 as immediate-early genes; genes 27, 28, and 37 to 40 as delayed-early genes; and gene 52 as a middle gene

Ceria nanoparticles vis-à-vis cerium nitrate as corrosion inhibitors for silica-alumina hybrid sol-gel coating

The present work provides a comparative study on the corrosion protection efficiency of defect free sol-gel hybrid coating containing ceria nanoparticles and cerium nitrate ions as corrosion inhibitors. Less explored organically modified alumina-silica hybrid sol-gel coatings are synthesized from 3-glycidoxypropyltrimethoxysilane and aluminium-tri-sec-butoxide. The microemulsion derived nanoparticles and the hybrid coatings are characterized and compared with coatings containing cerium nitrate. Corrosion inhibiting capability is assessed using electrochemical impedance spectroscopy. Scanning Kelvin probe measurements are also conducted on the coatings for identifying the apparent corrosion prone regions. Detailed X-ray photoelectron spectroscopy (XPS) analysis is carried out to comprehend the bonding and corrosion protection rendered by the hybrid coatings

Silica-alumina based sol-gel coating containing cerium oxide nanofibers as a potent alternative to conversion coating for AA2024 alloy

The current work demonstrates a study on the improved corrosion protection efficiency of a defect-free sol-gel hybrid coating consisting of cerium oxide nanofibers vis-à-vis sol-gel coating containing commercial nanosize ceria particles as corrosion inhibitors. The less researched organically modified silica-alumina (Si-Al) hybrid sol-gel coating containing cerium oxide nanofibers and commercial ceria are synthesized from 3-glycidoxypropyltrimethoxysilane and aluminum-tri-sec-butoxide. The sol-gel matrix containing cerium oxide nanofibers exhibiting Ce mainly in +3 oxidation state exhibits improved corrosion resistance as corroborated by electrochemical impedance spectroscopy. The corrosion property of this sol-gel coating commensurates well with the conventional chromate conversion coating (CCC) as evidenced by the neutral salt spray test. The developed coating exhibits good compatibility with the top primer layer and thus ascertains that the developed Si-Al based sol-gel coating containing cerium oxide nanofibers is a potent alternative to conventional CCC

Sol-gel based organic-inoganic hybrid coatings for corrosion protection of aerospace aluminium alloy

Aluminum alloy 2024 is the most commonly used aircraft alloy because of its high damage tolerance, relatively high tensile strength and high strength to weight ratio. These properties are achieved by appropriate alloying with copper and magnesium which, in addition to strengthening phases, form copper -and magnesium- containing constituent particles. However, the presence of these alloying elements makes the alloy susceptible to localized corrosion making it impossible to use it without prior application of a corrosion protection system. Historically, the corrosion protection systems are based on Cr(VI) compounds which are now restricted due to their carcinogenic nature. In this direction, extensive research is pursued on organic–inorganic hybrid silane coatings to replace the toxic Cr (VI) component. In the present study, silica alumina hybrid sol -gel coatings are developed and explored for anticorrosion properties using electrochemical techniques and industry - standard tests. Apart from the basic coating, co rrosion inhibitors are explored to impart active protection to the alloy. The ability of silica - alumina coating to act as reservoir for storage of inhibitors is investigated. The results confirm that coatings containing cerium nitrate inhibitor in an optimum concentration offer superior protection to the surface. X-ray photoelectron and Raman spectroscopy studies provide evidence for the migration of cerium ions from the coating. Improved corrosion protection is attributed to the combined effect of the barr ier nature of the coating and the corrosion inhibiting nature of Ce3+ ions. Further, the role of morphology of the inhibitor when used in the form of solid particles instead of salts is studied. The compatibility of the developed sol -gel layer with subsequ ent top layers of the paint system is also evaluated

Development of Chemical Protective Clothing Using Multilayer Fabric for Hazardous Chemicals Handling

Protection against the safety of people is enforced for the certain occupations when they might be exposed to hazardous chemicals during handling. This research provides an importance of chemical protective clothing, along with its necessity during various industrial applications. The aim of the research is to develop more comfortable and efficient protective cloth for the chemical industry workers. Developed multilayer fabric is to protect them from harmful chemical hazards with five layers, the outer shell made of polyester as it has low absorption and carbon fabric for its higher support. It provides a good strength to the fabric and polyester has a good resistance to lab grade chemicals. The middle layer comprises spun-bonded non-woven sandwiched with carbon fiber. The inner layer is made up of cotton fabric as it gives good absorbency and comfort. In this research, 100% polyester fabric, polyester/cotton fabric and 100% knitted polyester fabric have been used as a comparison in chemical protective clothing. Scanning electronic microscope (SEM) was used to observe the morphology of coated surfaces of protective for process versatility and the highly specific surface area. In this paper, the thermal properties of developed multilayered structures were statistically investigated. The chemical protection, good air permeability, abrasion resistance, fabric stiffness and tearing strength have been performed. The results provide new insights into the development of functional garments/materials and better methods for evaluating the performance of these materials under hazardous work environments

Global stability of a delayed mosquito-transmitted disease model with stage structure

This article presents a new eco-epidemiological deterministic delay differential equation model considering a biological controlling approach on mosquitoes, for endemic dengue disease with variable host (human) and variable vector (Aedes aegypti) populations, and stage structure for mosquitoes. In this model, predator-prey interaction is considered by using larvae as prey and mosquito-fish as predator. We give a complete classification of equilibria of the model, and sufficient conditions for global stability/global attractivity of some equilibria are given by constructing suitable Lyapunov functionals and using Lyapunov-LaSalle invariance principle. Also, numerical simulations are presented to show the validity of our results

Necessary and sufficient conditions for oscillation of neutral delay differential equations

In this article, we concerned with oscillation of the neutral delay differential equation $[x(t)-px(t-\tau)]'+qx(t-\sigma)=0$ with constant coefficients. By constructing several suitable auxiliary functions, we obtained some necessary and sufficient conditions for oscillation of all the solutions of the aforementioned equation for the cases $0<p<1$ and $p>1$