Detailed Simulation of the Cochlea: Recent Progress Using Large Shared Memory Parallel Computers

We have developed and are refining a detailed three-dimensional computational model of the human cochlea. The model uses the immersed boundary method to calculate the fluid-structure interactions produced in response to incoming sound waves. An accurate cochlear geometry obtained from physical measurements is incorporated. The model includes a detailed and realistic description of the various elastic structures present. Initially, a macro-mechanical computational model was developed for execution on a CRAY T90 at the San Diego Supercomputing Center. This code was ported to the latest generation of shared memory high performance servers from Hewlett Packard. Using compiler generated threads and OpenMP directives, we have achieved a high degree of parallelism in the executable, which has made possible to run several large scale numerical simulation experiments to study the interesting features of the cochlear system. In this paper, we outline the methods, algorithms and software tools that were used to implement and fine tune the code, and discuss some of the simulation results

Parenting Programmes for preventing tobacco, alcohol or drugs misuse in children under 18 : a systematic review

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Health Education Research following peer review. The definitive publisher-authenticated version [Petrie, J. ,Bunn, F. and Byrne, G. (2007) 'Parenting Programmes for preventing tobacco, alcohol or drug abuse in children under 18:a systematic review'. Health Education Research 22 (2) pp.177-191] is available online at: http://her.oxfordjournals.org/archive/index.dtl --Copyright Oxford University PressWe conducted a systematic review of controlled studies of parenting programmes to prevent tobacco, alcohol or drug abuse in children under 18. We searched Cochrane Central Register of Controlled Trials, specialised Register of Cochrane Drugs and Alcohol Group, Pub Med, psych INFO, CINALH, and SIGLE. Two reviewers independently screened studies, extracted data and assessed study quality. Data were collected on actual or intended use of tobacco, alcohol or drugs by child, and associated risk or antecedent behaviours. Due to heterogeneity we did not pool studies in a meta-analysis and instead present a narrative summary of the findings. Twenty studies met our inclusion criteria. Statistically significant self-reported reductions of alcohol use were found in six of 14 studies, of drugs in five of nine studies and tobacco in nine out of 13 studies. Three interventions reported increases of tobacco, drug and alcohol use. We concluded that parenting programmes can be effective in reducing or preventing substance use. The most effective appeared to be those that shared an emphasis on active parental involvement and on developing skills in social competence, self-regulation and parenting. However, more work is needed to investigate further the change processes involved in such interventions and their long-term effectivenessPeer reviewe

Template fitting and the large-angle CMB anomalies

We investigate two possible explanations for the large-angle anomalies in the Cosmic Microwave Background (CMB): an intrinsically anisotropic model and an inhomogeneous model. We take as an example of the former a Bianchi model (which leaves a spiral pattern in the sky) and of the latter a background model that already contains a non-linear long-wavelength plane wave (leaving a stripy pattern in the sky). We make use of an adaptation of the ``template'' formalism, previously designed to detect galactic foregrounds, to recognize these patterns and produce confidence levels for their detection. The ``corrected'' maps, from which these patterns have been removed, are free of anomalies, in particular their quadrupole and octupole are not planar and their intensities not low. We stress that although the ``template'' detections are not found to be statistically significant they do correct statistically significant anomalies.Comment: 8 pages. MNRAS submitte

Sensitivity of a Bolometric Interferometer to the CMB power spectrum

Context. The search for B-mode polarization fluctuations in the Cosmic Microwave Background is one of the main challenges of modern cosmology. The expected level of the B-mode signal is very low and therefore requires the development of highly sensitive instruments with low systematic errors. An appealing possibility is bolometric interferometry. Aims. We compare in this article the sensitivity on the CMB angular power spectrum achieved with direct imaging, heterodyne and bolometric interferometry. Methods. Using a simple power spectrum estimator, we calculate its variance leading to the counterpart for bolometric interferometry of the well known Knox formula for direct imaging. Results. We find that bolometric interferometry is less sensitive than direct imaging. However, as expected, it is finally more sensitive than heterodyne interferometry due to the low noise of the bolometers. It therefore appears as an alternative to direct imagers with different and possibly lower systematic errors, mainly due to the absence of an optical setup in front of the horns.Comment: 5 pages, 3 figures. This last version matches the published version (Astronomy and Astrophysics 491 3 (2008) 923-927). Sensitivity of Heterodyne Interferometers modified by a factor of tw

Object Database Scalability for Scientific Workloads

We describe the PetaByte-scale computing challenges posed by the next generation of particle physics experiments, due to start operation in 2005. The computing models adopted by the experiments call for systems capable of handling sustained data acquisition rates of at least 100 MBytes/second into an Object Database, which will have to handle several PetaBytes of accumulated data per year. The systems will be used to schedule CPU intensive reconstruction and analysis tasks on the highly complex physics Object data which need then be served to clients located at universities and laboratories worldwide. We report on measurements with a prototype system that makes use of a 256 CPU HP Exemplar X Class machine running the Objectivity/DB database. Our results show excellent scalability for up to 240 simultaneous database clients, and aggregate I/O rates exceeding 150 Mbytes/second, indicating the viability of the computing models

Archival description and automation: a brief history of going digital

This paper outlines a skeleton chronology of the computerization of archival description within the United Kingdom. Considering a period from the 1960s to the early 1990s, it describes many of the early experiments and systems developed in UK archives and sketches out how the vision of automation or ‘going digital’ changed over time, in line with advances and changes in the underlying technological landscape. It also seeks to consider how archivists reacted to the challenges of the computer both in terms of a move towards cooperation and working together, but also in terms of a growing focus on the standardisation of archival description and descriptive practice. This focus on standardisation is considered and interrogated through the interconnected lenses of both; a power struggle – the reassertion of professional (human) standards in a move towards specifying the requirements required by the machines; and the reconsideration of practice. It suggests that the answer as to the exact balance of power between archivist and computer probably remains mute, particularly in respect of the exact impact of the computer on driving changes in archivists’ thinking around their descriptive practice

Exploring the potential for cross disciplinary working with archives and records management

This paper explores the potential of cross disciplinary working and collaboration between HCI and archives and records management. It highlights an emerging interest in personal digital archiving and sees this as a fruitful area for more transformative forms of cross disciplinary working. A study is described in which an attempt is made to expose and actively engage UK based archivists and records managers with a selection of literature and research about personal digital archiving taken from the ACM Digital Library. The aim of the study was to see what, if anything, could be learnt through this process and whether, and in what way, such interaction might engender new insight and innovation. Although little new insight and innovation were so engendered, the study still makes a contribution as a provocation to reflect on cross disciplinary working and its importance for shaping new fields of study such as personal digital archiving