Global asymptotic stability of steady states in a chemotaxis-growth system with singular sensitivity

This paper deals with a fully parabolic chemotaxis-growth system with singular sensitivity

under homogeneous Neumann boundary conditions in a smooth bounded domain $\Omega ?{\mathbb{R}}^2$, where the parameters $\chi ,\mu >0$ and $r\in \mathbb{R}$. Global existence and boundedness of solutions to the above system were established under some suitable conditions by Zhao and Zheng (2017). The main aim of this paper is further to show the large time behavior of global solutions which cannot be derived in the previous work.     

Digitising the R&D social network: revisiting the technological gatekeeper

This paper examines how the digitisation of the social network, and the resulting interplay between its online and offline components, has impacted the role of the technological gatekeeper in research and development (R&D) settings. Previous studies have firmly established the technological gatekeeper to be a key node in the innovation process – acquiring, translating and disseminating novel information throughout the R&D social network. Drawing on social network analysis and interview evidence from a software R&D group, we find that the gatekeeper role has undergone a division of labour. Theoretically, we contribute to the body of knowledge by developing an updated technological gatekeeper conceptual framework. For practitioners, we identify the competencies exhibited by the small number of communication specialists who are largely responsible for diffusing novel information. We then advise practitioners how to maximise the contribution of these ‘stars’ to the information flow network.     

On the Comparison Analysis of Two 4G-WiMAX Base Stations in an Urban Sub-Saharan African Environment

A growth in the demand for WBA （wireless broadband access） technology has been seen in Ghana in the last few years.. The reason for this growth can be attributed to the emergence of the use of multimedia applications, demands for ubiquitous high-speed Intemet connectivity, the massive growth in the wireless and mobile communications sector and the deregulation in the telecommunications industry. WiMAX, which is a WBA technology, is currently being deployed in the 2,500-2,690 MHz band to help serve the ever increasing needs of broadband internet subscribers in the country. This paper presents simulation results and field trial measurements for two BS （base stations） in a newly deployed 4G-WiMAX network in a typical dense urban Sub-Saharan African environment. We have used a model which uses the interference to noise ratio （n） parameter to obtain the coverage range of these two BS under evaluation. The simulated cell range for site 1 is 4.90 km and that for site 2 is 3.19 kin. The final coverage simulation and the field measurements results have also been presented.     

A Weighted Pseudo-potential Approach to Values for TU-games

This paper provides a twofold generalization of the well-known characterization of the Shapley value for TU-games as the discrete gradient of a so-called potential function. On the one hand the potential approach is extended to the so-called weighted pseudo-potential approach in the sense that the extended representation may incorporate, besides a fraction of the discrete gradient, a fraction of the underlying pseudo-potential function itself, as well as a fraction of the average of all the components of the gradient. On the other hand the paper fully characterizes the class of values for TU-games that admit a weighted pseudo-potential representation. Besides two individual constraints, these values have to be efficient, symmetric, and linear. The theory developed is illustrated by several examples of such values and their weighted pseudo-potential representations are discussed.     

Insights on Ceramics as Dental Materials. Part I: Ceramic Material Types in Dentistry

Ceramics are widely used biomaterials in prosthetic dentistry due to their attractive clinical properties. They are aesthetically pleasing with their color, shade and luster, and they are chemically stable. The main constituents of dental ceramic are Si-based inorganic materials, such as feldspar, quartz, and silica. Traditional feldspar-based ceramics are also referred to as “Porcelain”. The crucial difference between a regular ceramic and a dental ceramic is the proportion of feldspar, quartz, and silica contained in the ceramic. A dental ceramic is a multiphase system, i.e. it contains a dispersed crystalline phase surrounded by a continuous amorphous phase (a glassy phase). Modern dental ceramics contain a higher proportion of the crystalline phase that significantly improves the biomechanical properties of ceramics. Examples of these high crystalline ceramics include lithium disilicate and zirconia.     

Rapid swelling and deswelling of semi‐interpenetrating network poly(acrylic acid)/poly(aspartic acid) hydrogels prepared by freezing polymerization

Hydrogels with semi‐interpenetrating networks composed of poly(acrylic acid) (PAAc) and poly(aspartic acid) (PASP) have great potential for pharmaceutical and biomedical applications. In this study, we aimed to synthesize semi‐interpenetrating PAAc/PASP hydrogels with improved swelling–deswelling properties via two‐step polymerization, in which the first step of polymerization was performed at 37 °C for 15 min and the second step, the freezing polymerization, was performed at ?20 °C for 24 h. The synthesized hydrogels were characterized with field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The swelling and deswelling behaviors of the hydrogels in response to the ionic strength of the buffer solution were investigated. The Schott's swelling kinetic model was used to elucidate the swelling behavior of the hydrogels. The swelling and deswelling rates of the hydrogels prepared via freezing polymerization were faster than those of the hydrogels prepared via conventional polymerization. This was attributed to the large mean pore size of the freeze‐polymerized hydrogels. The PAAc/PASP hydrogels that underwent freezing polymerization had better swelling–deswelling characteristics than the PAAc hydrogels. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43515.     

Reduction of food matrix interference by a combination of sample preparation and multi-dimensional gating techniques to facilitate rapid, high sensitivity analysis for Escherichia coli serotype O157 by flow cytometry

Escherichia coli serotype O157 strains, which may be found in foods, often produce enterohemorrhagic toxins. The research goal was to facilitate rapid, sensitive detection in foods of E. coli serotype O157 by flow cytometry. Sample preparation methods were developed for potential use in 15 foods. Combined with multi-dimensional gating, these methods decreased time-to-results (TTR) for determination of low-level contamination. They mitigated the effects of interfering food components, concentrated cells for analysis without growth or, when necessary, used short-term incubation. The results showed qualitative analysis that was equivalent to culture plating in accuracy and superior in sensitivity and speed. Preparation time was 10–30 min per sample and detection took 3–4 min. Culture growth, if required, took an additional 4–6 h. A protocol for raw spinach analysis, using 4 h culture incubation, was 94% correct with one false negative for a low level inoculation. Its projected limit-of-detection (LOD) was 1 viable cell per 25 g of spinach, based on an average of 28 counts detected after growth and an estimated counts-to-threshold (C/T) ratio of 1.3. The results suggested potential uses for regulatory screening and food industry process control.