Virus Propagation in Multiple Profile Networks

Suppose we have a virus or one competing idea/product that propagates over a multiple profile (e.g., social) network. Can we predict what proportion of the network will actually get "infected" (e.g., spread the idea or buy the competing product), when the nodes of the network appear to have different sensitivity based on their profile? For example, if there are two profiles $\mathcal{A}$ and $\mathcal{B}$ in a network and the nodes of profile $\mathcal{A}$ and profile $\mathcal{B}$ are susceptible to a highly spreading virus with probabilities $\beta_{\mathcal{A}}$ and $\beta_{\mathcal{B}}$ respectively, what percentage of both profiles will actually get infected from the virus at the end? To reverse the question, what are the necessary conditions so that a predefined percentage of the network is infected? We assume that nodes of different profiles can infect one another and we prove that under realistic conditions, apart from the weak profile (great sensitivity), the stronger profile (low sensitivity) will get infected as well. First, we focus on cliques with the goal to provide exact theoretical results as well as to get some intuition as to how a virus affects such a multiple profile network. Then, we move to the theoretical analysis of arbitrary networks. We provide bounds on certain properties of the network based on the probabilities of infection of each node in it when it reaches the steady state. Finally, we provide extensive experimental results that verify our theoretical results and at the same time provide more insight on the problem

Dynamin-related protein Drp1 and mitochondria are important for Shigella flexneri infection

Abstract unavailable.Mabel Lum, Renato Moron

Myosin IIA is essential for Shigella flexneri cell-to-cell spread

First published online: 8 January 2015A key feature of Shigella pathogenesis is the ability to spread from cell-to-cell post-invasion. This is dependent on the bacteria's ability to initiate de novo F-actin tail polymerisation, followed by protrusion formation, uptake of bacteria-containing protrusion and finally, lysis of the double membrane vacuole in the adjacent cell. In epithelial cells, cytoskeletal tension is maintained by the actin-myosin II networks. In this study, the role of myosin II and its specific kinase, myosin light chain kinase (MLCK), during Shigella intercellular spreading was investigated in HeLa cells. Inhibition of MLCK and myosin II, as well as myosin IIA knockdown, significantly reduced Shigella plaque and infectious focus formation. Protrusion formation and intracellular bacterial growth was not affected. Low levels of myosin II were localised to the Shigella F-actin tail. HeLa cells were also infected with Shigella strains defective in cell-to-cell spreading. Unexpectedly loss of myosin IIA labelling was observed in HeLa cells infected with these mutant strains. This phenomenon was not observed with WT Shigella or with the less abundant myosin IIB isoform, suggesting a critical role for myosin IIA.Mabel Lum, Renato Moron

Overview of Highland Valley Tailings Storage Facility

This paper presents key features of the Highland Valley tailings storage facility comprising two tailings dams, a 107 m high H-H Dam and a 166 m high L-L Dam. The construction history to date including instrumentation observations is also reviewed. Although the tailings facility is situated in a low to moderate seismic area within the Interior Plateau of British Columbia, potential earthquake sources that might have an impact on the site have been carefully assessed. Both dams are designed to have adequate seismic resistance against design earthquakes appropriate for the site. The L-L Dam valley section, involving soft lacustrine deposits beneath the Starter Dam, has been buttressed by a compacted downstream berm founded on dense glacial till. As the geometry of the tailings storage and distribution facilities and waste dumps changes with time, the quantity and relative cost of various construction materials including natural borrow, cycloned sand and pit overburden also change. Ongoing construction is planned to maintain key earthquake and flood design criteria as well as to adjust the use and placement method of various materials to achieve an efficient and cost effective tailings storage operation. Inherent in the design of the two tailings dams, both constructed by the centerline method, is the flexibility which enables the storage capacity of the tailings facility to be increased beyond the present 1.8 billion tonnes if required at some future time

Method to reduce microbial bloom in poultry hatchery

Spore forming bacteria and Lactic Acid Bacteria for application in poultry hatcher cabinets to alter the bacterial bloom towards a more beneficial microbiota, positively affecting performance parameters such as mortality, body weight gain and feed conversion ratio throughout production

DNA-Based Authentication of Botanicals and Plant-Derived Dietary Supplements: Where Have We Been and Where Are We Going?

Herbal medicines and botanicals have long been used as sole or additional medical aids worldwide. Currently, billions of dollars are spent on botanicals and related products, but minimal regulation exists regarding their purity, integrity, and efficacy. Cases of adulteration and contamination have led to severe illness and even death in some cases. Identifying the plant material in botanicals and phytomedicines using organoleptic means or through microscopic observation of plant parts is not trivial, and plants are often misidentified. Recently, DNA-based methods have been applied to these products because DNA is not changed by growth conditions unlike the chemical constituents of many active pharmaceutical agents. In recent years, DNA barcoding methods, which are used to identify species diversity in the Tree of Life, have been also applied to botanicals and plant-derived dietary supplements. In this review, we recount the history of DNA-based methods for identification of botanicals and discuss some of the difficulties in defining a specific bar code or codes to use. In addition, we describe how next generation sequencing technologies have enabled new techniques that can be applied to identifying these products with greater authority and resolution. Lastly, we present case histories where dietary supplements, decoctions, and other products have been shown to contain materials other than the main ingredient stipulated on the label. We conclude that there is a fundamental need for greater quality control in this industry, which if not self-imposed, that may result from legislation

Wigs, disguises and child's play : solidarity in teacher education

It is generally acknowledged that much contemporary education takes place within a dominant audit culture, in which accountability becomes a powerful driver of educational practices. In this culture both pupils and teachers risk being configured as a means to an assessment and target-driven end: pupils are schooled within a particular paradigm of education. The article discusses some ethical issues raised by such schooling, particularly the tensions arising for teachers, and by implication, teacher educators who prepare and support teachers for work in situations where vocational aims and beliefs may be in in conflict with instrumentalist aims. The article offers De Certeau’s concept of ‘la perruque’ to suggest an opening to playful engagement for human ends in education, as a way of contending with and managing the tensions generated. I use the concept to recover a concept of solidarity for teacher educators and teachers to enable ethical teaching in difficult times

The impact of sound field systems on learning and attention in elementary school classrooms

Purpose: An evaluation of the installation and use of sound field systems (SFS) was carried out to investigate their impact on teaching and learning in elementary school classrooms. Methods: The evaluation included acoustic surveys of classrooms, questionnaire surveys of students and teachers and experimental testing of students with and without the use of SFS. Students ’ perceptions of classroom environments and objective data evaluating change in performance on cognitive and academic assessments with amplification over a six month period are reported. Results: Teachers were positive about the use of SFS in improving children’s listening and attention to verbal instructions. Over time students in amplified classrooms did not differ from those in nonamplified classrooms in their reports of listening conditions, nor did their performance differ in measures of numeracy, reading or spelling. Use of SFS in the classrooms resulted in significantly larger gains in performance in the number of correct items on the nonverbal measure of speed of processing and the measure of listening comprehension. Analysis controlling for classroom acoustics indicated that students ’ listening comprehension score