Modeling epidemics on a regular tree graph

We will first provide a brief introduction to models of disease transmission on so-called contact networks, which can be represented by various structures from the mathematical field of graph theory. These models allow for exploration of stochastic effects and incorporation of more biological detail than the classical compartment-based ordinary differential equation models, which usually assume both homogeneity in the population and uniform mixing. In particular, we use an agent-based modelling platform to compare theoretical predictions from mathematical epidemiology to results obtained from simulations of disease transmission on a regular tree graph. We also demonstrate how this graph reveals connections between network structure and the spread of infectious diseases. Specifically, we discuss results for how certain properties of the tree graph, such as network diameter and density, alter the duration of an outbreak

Managing the student experience in English higher education: Differing responses to market pressures

This paper reports on recent research aimed at assessing how the management of the undergraduate student experience in English higher education is changing in the light of the new tuition fee regime introduced in 2012, as well as other government policies aimed at creating market-type pressures within the higher education sector. A distinction was observed between the research-intensive universities studied – defined here as institutions where research income comprised 20 per cent or more of total turnover, with correspondingly strong positions in published research-based rankings – and universities largely dependent on income from teaching, with weaker market positions. Broadly speaking, the latter group were responding to market pressures by centralizing services, standardizing procedures, and strengthening management controls over teaching processes. The research-intensive universities tended to work within existing institutional cultures to respond to students’ needs. Organizational change here usually took the form of creating more coherent functional groupings of student services, rather than comprehensive reorganizations. It appears to us that these different responses to a changed environment point to the creation of two distinct English university types, one strongly managerial with ‘student as customer’ orientations, and a smaller group with less centralized, more collegial cultures

Temperature insensitive refractometer using core and cladding modes in open-top ridge waveguide

In order to overcome the well-known limitation of temperature instability in Bragg grating waveguide sensors, a temperature insensitive open-top ridge waveguide refractometer is developed by using a cladding mode resonance as a temperature reference. The relative shift of the core mode resonance to cladding mode resonance is used to measure the refractive index of substances under test. Specifically, the device fabricated here produces a relative resonance shift of 1 pm for every 5 × 10-4 of measured index change, with a temperature sensitivity ∼ 0.5 pm/°C

From Mendel’s discovery on pea to today’s plant genetics and breeding

In 2015, we celebrated the 150th anniversary of the presentation of the seminal work of Gregor Johann Mendel. While Darwin’s theory of evolution was based on differential survival and differential reproductive success, Mendel’s theory of heredity relies on equality and stability throughout all stages of the life cycle. Darwin’s concepts were continuous variation and “soft” heredity; Mendel espoused discontinuous variation and “hard” heredity. Thus, the combination of Mendelian genetics with Darwin’s theory of natural selection was the process that resulted in the modern synthesis of evolutionary biology. Although biology, genetics, and genomics have been revolutionized in recent years, modern genetics will forever rely on simple principles founded on pea breeding using seven single gene characters. Purposeful use of mutants to study gene function is one of the essential tools of modern genetics. Today, over 100 plant species genomes have been sequenced. Mapping populations and their use in segregation of molecular markers and marker–trait association to map and isolate genes, were developed on the basis of Mendel's work. Genome-wide or genomic selection is a recent approach for the development of improved breeding lines. The analysis of complex traits has been enhanced by high-throughput phenotyping and developments in statistical and modeling methods for the analysis of phenotypic data. Introgression of novel alleles from landraces and wild relatives widens genetic diversity and improves traits; transgenic methodologies allow for the introduction of novel genes from diverse sources, and gene editing approaches offer possibilities to manipulate gene in a precise manner

Modeling epidemics on a regular tree graph

We will first provide a brief introduction to models of disease transmission on so-called contact networks, which can be represented by various structures from the mathematical field of graph theory. These models allow for exploration of stochastic effects and incorporation of more biological detail than the classical compartment-based ordinary differential equation models, which usually assume both homogeneity in the population and uniform mixing. In particular, we use an agent-based modelling platform to compare theoretical predictions from mathematical epidemiology to results obtained from simulations of disease transmission on a regular tree graph. We also demonstrate how this graph reveals connections between network structure and the spread of infectious diseases. Specifically, we discuss results for how certain properties of the tree graph, such as network diameter and density, alter the duration of an outbreak

Managing the student experience in a shifting higher education landscape

This research report, prepared between January 2014 and July 2014, assesses how the management of the undergraduate student experience in English higher education (HE) is changing as a result of a more competitive environment, and in particular the impact of the new tuition fee regime introduced in 2012

Hybrid silica/polymer long period gratings for wavelength filtering and power distribution

We report long period grating (LPG) devices based on a hybrid architecture incorporating photopatternable fluorinated poly(aryl ether ketone) and silica layers for applications in wavelength filtering and power distribution. The grating structure was implemented using a periodic corrugation on a thermally oxidized silica lower cladding layer, a photopatterned fluorinated polymer ridge waveguide, and a similar polymer top cladding. In this design, the corrugated silica layer allows a highly stable grating structure, while the fluorinated polymer offers a low propagation loss and easy processability. Strong rejection bands have been demonstrated in the C + L wavelength band, in good agreement with theoretical calculations. The fabricated LPG devices show a thermal dependence of 1:5nm/\ub0C. Based on this design, an array of waveguides incorporating LPGs has also been fabricated. Distribution of light at the resonance wavelength across all the channels from a single input has been demonstrated. These results are promising for power distribution in photonic network applications or on-chip sensors.Peer reviewed: YesNRC publication: Ye