A Model for the Analysis of Caries Occurrence in Primary Molar Tooth Surfaces

Recently methods of caries quantification in the primary dentition have moved away from summary ‘whole mouth’ measures at the individual level to methods based on generalised linear modelling (GLM) approaches or survival analysis approaches. However, GLM approaches based on logistic transformation fail to take into account the time-dependent process of tooth/surface survival to caries. There may also be practical difficulties associated with casting parametric survival-based approaches in a complex multilevel hierarchy and the selection of an optimal survival distribution, while non-parametric survival methods are not generally suitable for the assessment of supplementary information recorded on study participants. In the current investigation, a hybrid semi-parametric approach comprising elements of survival-based and GLM methodologies suitable for modelling of caries occurrence within fixed time periods is assessed, using an illustrative multilevel data set of caries occurrence in primary molars from a cohort study, with clustering of data assumed to occur at surface and tooth levels. Inferences of parameter significance were found to be consistent with previous parametric survival-based analyses of the same data set, with gender, socio-economic status, fluoridation status, tooth location, surface type and fluoridation status-surface type interaction significantly associated with caries occurrence. The appropriateness of the hierarchical structure facilitated by the hybrid approach was also confirmed. Hence the hybrid approach is proposed as a more appropriate alternative to primary caries modelling than non-parametric survival methods or other GLM-based models, and as a practical alternative to more rigorous survival-based methods unlikely to be fully accessible to most researchers

Efficient Hadronic Operators in Lattice Gauge Theory

We study operators to create hadronic states made of light quarks in quenched lattice gauge theory. We construct non-local gauge-invariant operators which provide information about the spatial extent of the ground state and excited states. The efficiency of the operators is shown by looking at the wave function of the first excited state, which has a node as a function of the spatial extent of the operator. This allows one to obtain an uncontaminated ground state for hadrons.Comment: 18 pages, Latex text, followed by 11 postscript figures in self-unpacking file. Also available at ftp://suna.amtp.liv.ac.uk/pub/cmi/wavefn

A dynamics-driven approach to precision machines design for micro-manufacturing and its implementation perspectives

Precision machines are essential elements in fabricating high quality micro products or micro features and directly affect the machining accuracy, repeatability and efficiency. There are a number of literatures on the design of industrial machine elements and a couple of precision machines commercially available. However, few researchers have systematically addressed the design of precision machines from the dynamics point of view. In this paper, the design issues of precision machines are presented with particular emphasis on the dynamics aspects as the major factors affecting the performance of the precision machines and machining processes. This paper begins with a brief review of the design principles of precision machines with emphasis on machining dynamics. Then design processes of precision machines are discussed, and followed by a practical modelling and simulation approaches. Two case studies are provided including the design and analysis of a fast tool servo system and a 5-axis bench-top micro-milling machine respectively. The design and analysis used in the two case studies are formulated based on the design methodology and guidelines

General Board Geometry

Game boards are described in the Ludii general game system by their underlying graphs, based on tiling, shape and graph operators, with the automatic detection of important properties such as topological relationships between graph elements, directions and radial step sequences. This approach allows most conceivable game boards to be described simply and succinctly

Preconception nutrition: building advocacy and social movements to stimulate action

Action to improve preconception nutrition is a collective, societal responsibility. We believe that the Developmental Origins of Health and Disease (DOHaD) society is ideally placed to facilitate the development of a global agenda for preconception nutrition which recognises the societal importance of nutrition for young women and men, and supports them in optimising their nutritional status for the benefit of the next generation. In this paper, we outline four key actions that can be taken by the members of DOHaD's international society located across 67 countries, and nine regional societies, to demonstrate this leadership role. The recommended actions to place preconception nutrition at the top of national and regional agendas include (i) continuing to build the scientific evidence, (ii) monitoring of progress made by governments and commercial companies, (iii) developing advocacy coalitions that unite individuals and organisations around common policy options and (iv) working with partners to develop an emotive and empowering preconception nutrition awareness campaign. Collectively, these actions hold the potential to develop into a preconception nutrition social movement to invoke high-level government support and across-sector policy action, while raising public demand for action and engaging corporate actors

Quantum walks in higher dimensions

We analyze the quantum walk in higher spatial dimensions and compare classical and quantum spreading as a function of time. Tensor products of Hadamard transformations and the discrete Fourier transform arise as natural extensions of the quantum coin toss in the one-dimensional walk simulation, and other illustrative transformations are also investigated. We find that entanglement between the dimensions serves to reduce the rate of spread of the quantum walk. The classical limit is obtained by introducing a random phase variable.Comment: 6 pages, 6 figures, published versio

Doing the right thing for one's children: deciding whether to take the genetic test for Huntington's disease as a moral dilemma

This is a qualitative examination of candidates’ decision-making in relation to the genetic test for Huntington's disease (HD). Semi-structured interviews were conducted with nine participants who were asked about factors influencing their decision whether to take up predictive genetic testing. Transcripts of interviews were subjected to interpretative phenomenological analysis to elicit emergent themes. A key factor for participants was to do the right thing for their children. Interestingly this factor presents a moral dilemma to participants and can direct them either towards or away from testing. This paper offers a detailed examination of how participants think through this dilemma

Study of Space Station propulsion system resupply and repair Final report

Resupply and repair capabilities for orbital space station bipropellant propulsion syste