Sediment source fingerprinting: benchmarking recent outputs, remaining challenges and emerging themes

Abstract: Purpose: This review of sediment source fingerprinting assesses the current state-of-the-art, remaining challenges and emerging themes. It combines inputs from international scientists either with track records in the approach or with expertise relevant to progressing the science. Methods: Web of Science and Google Scholar were used to review published papers spanning the period 2013–2019, inclusive, to confirm publication trends in quantities of papers by study area country and the types of tracers used. The most recent (2018–2019, inclusive) papers were also benchmarked using a methodological decision-tree published in 2017. Scope: Areas requiring further research and international consensus on methodological detail are reviewed, and these comprise spatial variability in tracers and corresponding sampling implications for end-members, temporal variability in tracers and sampling implications for end-members and target sediment, tracer conservation and knowledge-based pre-selection, the physico-chemical basis for source discrimination and dissemination of fingerprinting results to stakeholders. Emerging themes are also discussed: novel tracers, concentration-dependence for biomarkers, combining sediment fingerprinting and age-dating, applications to sediment-bound pollutants, incorporation of supportive spatial information to augment discrimination and modelling, aeolian sediment source fingerprinting, integration with process-based models and development of open-access software tools for data processing. Conclusions: The popularity of sediment source fingerprinting continues on an upward trend globally, but with this growth comes issues surrounding lack of standardisation and procedural diversity. Nonetheless, the last 2 years have also evidenced growing uptake of critical requirements for robust applications and this review is intended to signpost investigators, both old and new, towards these benchmarks and remaining research challenges for, and emerging options for different applications of, the fingerprinting approach

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

The prevalence of Plasmodium falciparum in sub-Saharan Africa since 1900

Malaria transmission is influenced by climate, land use and deliberate intervention. Recent declines have been observed in malaria transmission. Here, we show that the continent has witnessed a long-term recession in the prevalence of Plasmodium falciparum since 1900-29 (40%) to 2010-15 (24%), interrupted at different times by periods of rapidly increasing and decreasing transmission. The cycles and trend over the last 115 years are inconsistent with simplistic explanations in terms of climate or intervention alone. Previous global initiatives had minor impacts on malaria transmission, and a historically unprecedented decline has been observed since 2000. However, there has been little change to the continued high transmission belt covering large parts of West and Central Africa. Previous efforts to model the changing patterns of P. falciparum transmission intensity in Africa have been limited to the last 15 years1,2, or have used maps of historical expert opinion3. We provide quantitative data comprising 50,424 surveys at 36,966 geocoded locations to cover 115 years of malaria history in sub-Saharan Africa

The prevalence of Plasmodium falciparum in sub-Saharan Africa since 1900

Malaria transmission is influenced by climate, land use and deliberate intervention. Recent declines have been observed in malaria transmission. Here, we show that the continent has witnessed a long-term recession in the prevalence of Plasmodium falciparum since 1900-29 (40%) to 2010-15 (24%), interrupted at different times by periods of rapidly increasing and decreasing transmission. The cycles and trend over the last 115 years are inconsistent with simplistic explanations in terms of climate or intervention alone. Previous global initiatives had minor impacts on malaria transmission, and a historically unprecedented decline has been observed since 2000. However, there has been little change to the continued high transmission belt covering large parts of West and Central Africa. Previous efforts to model the changing patterns of P. falciparum transmission intensity in Africa have been limited to the last 15 years1,2, or have used maps of historical expert opinion3. We provide quantitative data comprising 50,424 surveys at 36,966 geocoded locations to cover 115 years of malaria history in sub-Saharan Africa

Deconvoluting lung evolution: from phenotypes to gene regulatory networks.

Speakers in this symposium presented examples of respiratory regulation that broadly illustrate principles of evolution from whole organ to genes. The swim bladder and lungs of aquatic and terrestrial organisms arose independently from a common primordial "respiratory pharynx" but not from each other. Pathways of lung evolution are similar between crocodiles and birds but a low compliance of mammalian lung may have driven the development of the diaphragm to permit lung inflation during inspiration. To meet the high oxygen demands of flight, bird lungs have evolved separate gas exchange and pump components to achieve unidirectional ventilation and minimize dead space. The process of "screening" (removal of oxygen from inspired air prior to entering the terminal units) reduces effective alveolar oxygen tension and potentially explains why nonathletic large mammals possess greater pulmonary diffusing capacities than required by their oxygen consumption. The "primitive" central admixture of oxygenated and deoxygenated blood in the incompletely divided reptilian heart is actually co-regulated with other autonomic cardiopulmonary responses to provide flexible control of arterial oxygen tension independent of ventilation as well as a unique mechanism for adjusting metabolic rate. Some of the most ancient oxygen-sensing molecules, i.e., hypoxia-inducible factor-1alpha and erythropoietin, are up-regulated during mammalian lung development and growth under apparently normoxic conditions, suggesting functional evolution. Normal alveolarization requires pleiotropic growth factors acting via highly conserved cell-cell signal transduction, e.g., parathyroid hormone-related protein transducing at least partly through the Wingless/int pathway. The latter regulates morphogenesis from nematode to mammal. If there is commonality among these diverse respiratory processes, it is that all levels of organization, from molecular signaling to structure to function, co-evolve progressively, and optimize an existing gas-exchange framework

Immobilisation of bovine enterokinase and application of the immobilised enzyme in fusion protein cleavage

Kubitzki T, Noll T, Luetz S. Immobilisation of bovine enterokinase and application of the immobilised enzyme in fusion protein cleavage. BIOPROCESS AND BIOSYSTEMS ENGINEERING. 2008;31(3):173-182.Two immobilisation methods for enterokinase were developed, which yielded high remaining activities for the cleavage of the fusion protein MUC1-IgG Fc. Different carrier materials were compared regarding remaining enzyme activity and storage stability. Immobilisation procedures involving support material activation using glutardialdehyde were found to result in low remaining activities. Applying less aggressive activation procedures, remaining activities of similar to 60% were received when immobilising enterokinase on either Estapor paramagnetic microspheres or hexamethylamino Sepabeads(R). In case of hexamethylamino Sepabeads(R) we were able to increase the half-life time 4.3-fold at 23 degrees C and 3.8-fold at 4 degrees C compared to the free enzyme at the same temperatures. By immobilising the biocatalyst the downstream process is simplified allowing the easy removal of the enzyme from the reaction mixture. The immobilised enterokinase cleaves the fusion protein MUC1-IgG Fc in at least two repeated batches, proving the efficiency of the immobilisation method and the reusability of the biocatalyst