INTRODUCTION Sierra Leone was in the process of strengthening tracing of Ebola Virus Disease (EVD) contact with training of contact tracers, continuous mentoring and monitoring, supervision and continuous support. This was through various national and international organizations. This study aimed at identifying the challenges of contact tracers with a view of improving contact tracing activitie...

Molecular organic geochemical proxies are increasingly being utilized to reconstruct past environmental conditions as new tools continue to be discovered and developed. To date, organic geochemical proxies have been developed mainly for use in marine systems and are widely used in paleoceanography. In contrast, organic proxies have been less commonly used on lacustrine sedimentary records. One ...

A two-dimensional model for colloid transport in geochemically and physically heterogeneous porous media is presented. The model considers patchwise geochemical heterogeneity, which is suitable to describe the chemical variability of many surficial aquifers with ferric oxyhydroxide-coated porous matrix, as well as spatial variability of hydraulic conductivity, which results in heterogeneous flo...

Microbial communities and their associated metabolic activity in marine sediments have a profound impact on global biogeochemical cycles. Their composition and structure are attributed to geochemical and physical factors, but finding direct correlations has remained a challenge. Here we show a significant statistical relationship between variation in geochemical composition and prokaryotic comm...

Magnetic Particle Imaging (MPI) shows promise for medical imaging, particularly in angiography of patients with chronic kidney disease. As the first biomedical imaging technique that truly depends on nanoscale materials properties, MPI requires highly optimized magnetic nanoparticle tracers to generate quality images. Until now, researchers have relied on tracers optimized for MRI T2*-weighted ...

designing effective strategies for sediment management and control is closely related to identification of sediment sources in a drainage basin. one of the methods for investigating sediment sources is using magnetic tracers for erosion and sediment yield studies. sediment source identification using magnetic characteristics is a simple, inexpensive, quick and non-destructive method having appl...

We compared three different methods for radioiodination of human spleen ferritin. Tracers prepared by direct oxidative iodination with use of Chloramine T or 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycoluril (Iodogen) were structurally altered by the labeling procedure, as was made apparent by gel filtration and electrophoresis on polyacrylamide gel. Tracers prepared by conjugation to rad...

in this research work, the frequency domain (fd) of surface geochemical data was analyzed to decompose the complex geochemical patterns related to different depths of the mineral deposit. in order to predict the variation in mineralization in the depth and identify the deep geochemical anomalies and blind mineralization using the surface geochemical data for the dalli cu-au porphyry deposit, a ...

47 The interpretation of the Cretaceous-Paleogene (K-Pg) iridium anomaly – and other 48 impact ejecta – as the result of a single, large asteroid impact has been the subject of much 49 debate, in part due to the distribution of impact markers beyond the narrow confines of the K-Pg 50 boundary sedimentary layer. Here, we revisit the hypothesized processes leading to the shape of 51 K-Pg iridium ...

Aqueous fluids play a significant role in the transport of heat and matter in the Earth’s crust and the upper mantle, and high-field-strength elements such as Zr are important geochemical tracers for these processes. However, the dissolution mechanism and complexation of Zr in the fluids at high pressure and temperature are unknown, in part because very low concentrations present severe experim...