F4: An All-Purpose Tool for Multivariate Time Series Classification

We propose Fast Forest of Flexible Features (F4), a novel approach for classifying multivariate time series, which is aimed to discriminate between underlying generating processes. This goal has barely been addressed in the literature. F4 consists of two steps. First, a set of features based on the quantile cross-spectral density and the maximum overlap discrete wavelet transform are extracted from each series. Second, a random forest is fed with the extracted features. An extensive simulation study shows that F4 outperforms some powerful classifiers in a wide variety of situations, including stationary and nonstationary series. The proposed method is also capable of successfully discriminating between electrocardiogram (ECG) signals of healthy subjects and those with myocardial infarction condition. Additionally, despite lacking shape-based information, F4 attains state-of-the-art results in some datasets of the University of East Anglia (UEA) multivariate time series classification archive.

Factors Affecting Shellfish Quality in Terms of Faecal Contamination at Blakeney Point, East Anglia, UK

Relatively high E. coli and Faecal Streptococci (FS) numbers have been reported in the waters surrounding Blakeney Point, East Anglia, UK, an area containing significant shellfishery industries including mussels and cockles, despite the implementation of development works aimed at reducing residual contamination problems. The aim of this study was to evaluate the potential of using bacterial analyses and sterol profiling to assess the current levels and source of faecal pollution at Blakeney Point. No evidence of significant human faecal contamination of water in and around Blakeney Point could be found using either traditional microbiological analyses or sterol profile analysis. The presence of significant quantities of sitosterol, however, suggests that faecal contamination of water from birds does occur but at the concentration detected would not affect water quality. Analysis of cockles and mussels taken from the area show that negligible levels of coprostanol were present, confirming that faecal pollution was not causing any contamination issues. Apart from cholesterol, brassicasterol, an algal biomarker, as expected was dominant in shellfish flesh. The results confirm that current water treatment processes are successful in ensuring water quality at Blakeney Point and that a combination of microbial testing with sterol profile analysis confirmed that low microbial concentrations of faecal contaminants present in and around Blakeney Point most probably originate from migratory and/or resident bird species.

Career intentions and perceptions of general practice on entry to medical school: baseline findings of a longitudinal survey at three UK universities

BackgroundMedical graduates from the universities of Oxford and Cambridge have a lower intention to become general practitioners compared to other UK medical graduates. It is not clear to what extent this difference is present on admission to medical school.AimTo compare the career intention and influencing factors of students on admission to different medical schools.Design & settingFirst year of a six year prospective cohort study of medical students admitted to the three East of England medical schools in Autumn 2020: University of East Anglia(UEA), University of Cambridge (UOC) and Anglia Ruskin University (ARU).MethodAn online survey instrument was administered at the start of the first year. This measured self-reported career interests and various influencing factors including perceptions of general practice.ResultsUOC students declared a lower intention to become a doctor, a higher likelihood of choosing careers in pathology and public health and a much lower likelihood of becoming a GP (all at P<0.001). In all three schools, the phrases least associated with general practice were “opportunities for creativity/innovation” and “research/academic opportunities” while the phrases most associated with general practice were “favourable working hours” and “flexibility”. However, research/academic opportunities were far more important, and favourable working hours far less important, to UOC students (P<0.001 for both).ConclusionsUOC students’ lower intention to become a GP appears to be present on entry to medical school. This may be explained in part by these students placing a higher importance on research/academic opportunities combined with the widely held perception that GP careers lack these opportunities.