Scrub typhus ecology: a systematic review of Orientia in vectors and hosts

Abstract Scrub typhus, caused by Orientia tsutsugamushi, is an important and neglected vector-borne zoonotic disease with an expanding known distribution. The ecology of the disease is complex and poorly understood, impairing discussion of public health interventions. To highlight what we know and the themes of our ignorance, we conducted a systematic review of all studies investigating the pathogen in vectors and non-human hosts. A total of 276 articles in 7 languages were included, with 793 study sites across 30 countries. There was no time restriction for article inclusion, with the oldest published in 1924. Seventy-six potential vector species and 234 vertebrate host species were tested, accounting for over one million trombiculid mites (‘chiggers’) and 83,000 vertebrates. The proportion of O. tsutsugamushi positivity was recorded for different categories of laboratory test and host species. Vector and host collection sites were geocoded and mapped. Ecological data associated with these sites were summarised. A further 145 articles encompassing general themes of scrub typhus ecology were reviewed. These topics range from the life-cycle to transmission, habitats, seasonality and human risks. Important gaps in our understanding are highlighted together with possible tools to begin to unravel these. Many of the data reported are highly variable and inconsistent and minimum data reporting standards are proposed. With more recent reports of human Orientia sp. infection in the Middle East and South America and enormous advances in research technology over recent decades, this comprehensive review provides a detailed summary of work investigating this pathogen in vectors and non-human hosts and updates current understanding of the complex ecology of scrub typhus. A better understanding of scrub typhus ecology has important relevance to ongoing research into improving diagnostics, developing vaccines and identifying useful public health interventions to reduce the burden of the disease.</jats:p

Gamma Prime Precipitate Evolution During Aging of a Model Nickel-Based Superalloy

The microstructural stability of nickel-based superalloys is critical for maintaining alloy performance during service in gas turbine engines. In this study, the precipitate evolution in a model polycrystalline Ni-based superalloy during aging to 1000 hours has been studied via transmission electron microscopy, atom probe tomography and neutron diffraction. Variations in phase composition and precipitate morphology, size and volume fraction were observed during aging, whilst the constrained lattice misfit remained constant at approximately zero. The experimental composition of the γ matrix phase was consistent with thermodynamic equilibrium predictions, whilst significant differences were identified between the experimental and predicted results from the γʹ phase. These results have implications for the evolution of mechanical properties in service and their prediction using modeling methods.The authors wish to acknowledge Mrs. S. Rhodes, Dr. H.T. Pang, Dr. D.M. Collins, and Dr. O.M.D.M. Messé for their assistance with the experiments performed. Funding was provided by the EPSRC/Rolls-Royce Strategic Partnership under EP/M005607/1 and EP/H022309/1. The Oxford Atom Probe facility was funded by the EPSRC under EP/M022803/1. Neutron diffraction beam time was supported through the Canadian Neutron Beam Centre under Experiment number 1258

A phase-field/Monte-Carlo model describing organic crystal growth from solution

68.35.Ct Interface structure and roughness, 68.43.Mn Adsorption kinetics, 68.55.Ac Nucleation and growth: microscopic aspects,

Bedside prediction of the progress of pressure ulcer healing in patients with spinal cord injury using the 'Decu-stick'

Study design: This is a prospective cohort study. Objectives: The objective of this study was to predict the progress of healing of pressure ulcers (PUs) in spinal cord injury (SCI) patients after the first 4 weeks. Setting: The study was conducted in a specialized SCI rehabilitation unit in The Netherlands. Methods: Weekly measurements of length, width and depth/undermining of grades II-IV PUs under sacrum or ischial tuberosity in SCI patients with the 'Decu-stick' were taken. The speed of reduction of the greatest dimension in the first 4 weeks of the granulation-epithelization (G-E) phase was compared with the speed of reduction of this dimension after week 4 until the end of observation. Results: Fifty-one PUs in 45 patients were measured. During the first 4 weeks of the G-E phase, the greatest dimension of 23/51 PUs reduced with a speed of >= 0.5 cm per week. In 22 of these 23 PUs, this speed remained >= 0.5 from week 4 until the end of observation (weeks 5-22). Closure: 21 patients (pts); operation: 2 pts. Of 28/51 PUs, this dimension reduced with Conclusion: Measurement of PUs in SCI patients with the 'Decu-stick' provides a reliable, quick, cheap and easy-to-learn bedside method to predict the progress of healing in PUs in SCI patients after 4 weeks of conservative treatment with a positive predictive value of 0.95 and an negative predictive value of 0.96. This provides a scientific basis for the decision on operative or alternative conservative treatment