Generalising Deep Learning MRI Reconstruction across Different Domains

We look into robustness of deep learning based MRI reconstruction when tested on unseen contrasts and organs. We then propose to generalise the network by training with large publicly-available natural image datasets with synthesised phase information to achieve high cross-domain reconstruction performance which is competitive with domain-specific training. To explain its generalisation mechanism, we have also analysed patch sets for different training datasets.Comment: Accepted for ISBI2019 as a 1-page abstrac

Demonstrating PM2.5 and road-side dust pollution by heavy metals along Thika superhighway in Kenya, sub-Saharan Africa

This study assessed the level of heavy metal in roadside dust and PM2.5 mass concentrations along Thika superhighway in Kenya. Thika superhighway is one of the busiest roads in Kenya, linking Thika town with Nairobi. Triplicate road dust samples collected from 12 locations were analysed for lead (Pb), chromium (Cr), cadmium (Cd), nickel (Ni), zinc (Zn), and copper (Cu) using atomic absorption spectrophotometry (AAS). PM2.5 samples were collected on pre-weighed Teflon filters using a BGI personal sampler and the filters were then reweighed. The ranges of metal concentrations were 39–101 μg/g for Cu, 95–262 μg/g for Zn, 9–28 μg/g for Cd, 14–24 μg/g for Ni, 13–30 μg/g for Cr, and 20–80 μg/g for Pb. The concentrations of heavy metals were generally highly correlated, indicating a common anthropogenic source of the pollutants. The results showed that the majority of the measured heavy metals were above the background concentration, and in particular, Cd, Pb, and Zn levels indicated moderate to high contamination. Though not directly comparable due to different sampling timeframes (8 h in this study and 24 h for guideline values), PM2.5 for all sites exceeds the daily WHO PM2.5 guidelines of 25 μg/m3. This poses a health risk to people using and working close to Thika superhighway, for example, local residents, traffic police, street vendors, and people operating small businesses. PM2.5 levels were higher for sites closer to Nairobi which could be attributed to increased vehicular traffic towards Nairobi from Thika. This study provides some evidence of the air pollution problem arising from vehicular traffic in developing parts of the world and gives an indication of the potential health impacts. It also highlights the need for source apportionment studies to determine contributions of anthropogenic emissions to air pollution, as well as long-term sampling studies that can be used to fully understand spatiotemporal patterns in air pollution within developing regions

Complex diffusion-weighted image estimation via matrix recovery under general noise models

We propose a patch-based singular value shrinkage method for diffusion magnetic resonance image estimation targeted at low signal to noise ratio and accelerated acquisitions. It operates on the complex data resulting from a sensitivity encoding reconstruction, where asymptotically optimal signal recovery guarantees can be attained by modeling the noise propagation in the reconstruction and subsequently simulating or calculating the limit singular value spectrum. Simple strategies are presented to deal with phase inconsistencies and optimize patch construction. The pertinence of our contributions is quantitatively validated on synthetic data, an in vivo adult example, and challenging neonatal and fetal cohorts. Our methodology is compared with related approaches, which generally operate on magnitude-only data and use data-based noise level estimation and singular value truncation. Visual examples are provided to illustrate effectiveness in generating denoised and debiased diffusion estimates with well preserved spatial and diffusion detail.Comment: 26 pages, 9 figure

Evidence for a stratigraphic basis for the Anthropocene

The Anthropocene was proposed as a term (Crutzen and Stoermer 2000) before consideration was given to the nature of the key signatures, contrasting with standard procedures for defining such units. The term is being widely used in both popular and scientific publications before a decision is made as to whether it warrants formalisation and definition of a Global Stratigraphic Section and Point (GSSP). The deliberate human modification of the landscape and its subsurface, and the creation of human-generated novel sedimentary deposits, minerals, and landforms, are characteristic features of the development of Earth’s surface and near surface, which has accelerated in the past two centuries. The large-scale intentional excavation, transportation, and deposition of mixtures of rock and soil to form anthropogenic deposits and landforms represent a new geological process that could be used as a diagnostic signature of the Anthropocene

Cardiovascular Magnetic Resonance Imaging in Experimental Models

Cardiovascular magnetic resonance (CMR) imaging is the modality of choice for clinical studies of the heart and vasculature, offering detailed images of both structure and function with high temporal resolution

Pathways into services for offenders with intellectual disabilities : childhood experience, diagnostic information and offence variables

The patterns and pathways into intellectual disability (ID) offender services were studied through case file review for 477 participants referred in one calendar year to community generic, community forensic, and low, medium, and maximum secure services. Data were gathered on referral source, demographic information, index behavior, prior problem behaviors, diagnostic information, and abuse or deprivation. Community referrers tended to refer to community services and secure service referrers to secure services. Physical and verbal violence were the most frequent index behaviors, whereas contact sexual offenses were more prominent in maximum security. Age at first incident varied with security, with the youngest in maximum secure services. Attention-deficit/hyperactivity disorder or conduct disorder was the most frequently recorded diagnosis, and severe deprivation was the most frequent adverse developmental experience. Fire starting, theft, and road traffic offenses did not feature prominently. Generic community services accepted a number of referrals with forensic-type behavior and had higher proportions of both women and people with moderate or severe ID