Estimation of Reminant Gold Resources of Old Underground Workings by Indicator Approach – A Case Study

The lack of geological control and old underground development at AngloGold Ashanti (Bibiani mine) in Ghana was a major setback for the conventional methods of resource estimation to produce accurate estimates of the deposit. Consequently, inverse distance weighting of indicator variables were used. This estimation approach, however, overestimated the boundaries of the old underground workings (voids) into inappropriate areas of the resource model and thereby caused significant underestimation of ore tonnage and overestimation of grade. This paper highlights the study that re-evaluated the Bibiani deposit using indicator kriging. The results of re-evaluated reserves compared well with actual production figures in terms of tonnes, grade and stoping volum

Molecular characterisation of an Acinetobacter baumannii outbreak

Background: Acinetobacter baumannii are problematic hospital pathogens, and the increased incidence of multi drug resistance has significantly limited treatment options. The global epidemiology is not fully characterised due to large data gaps from low- and middle-income countries. This study characterised the molecular epidemiology of an A. baumanniii outbreak in Egypt. Methods: Fifty-four A. baumannii isolates were recovered from a 4-month-outbreak at Tanta University Hospitals (TUH). Associated clinical and demographic data, and the antibiogram were analysed, and carbapenem resistant isolates were screened for acquired carbapenemase genes by PCR and sequencing. Epidemiological typing was performed by single-locus sequencing of blaOXA-51-like and Multi Locus Sequence Typing (MLST), and sequence types (STs) were analysed based on maximum-likelihood phylogeny (PhyML) to identify relatedness. Findings: Immune suppression and ICU admission were the most common co-morbidity and risk factor. Carbapenem resistance accounted for 81%, and correlated with the presence of OXA-23, NDM-1 and -2, and VIM-1 and -2 carbapenemases. Nine different blaOXA-51-like genes were identified which corresponded to 22 different Sequence Types (STs), including 10 novel. International clone (IC2) was the predominant clone. PhyML analysis revealed the presence of 2 distinct clones with multiple sub-lineages. Conclusion: Given the short duration of the study, there was a rare heterogeneous population in the hospital. Carbapenem resistance is mediated by acquired carbapenemases in diverse lineages indicating the possibility of horizontal gene transfer. The diversity indicates the influx of multiple lineages of IC2 into TUH from unknown sources. Molecular epidemiological studies are essential for infection prevention and control measures

The Trajectory of Lost Mercury in Artisanal and Small Scale Gold Extraction in Ghana

AbstractThe Artisanal and Small Scale Mining (ASSM) industry is of great importance to the Ghanaian economy. It provides employment for the teeming youth directly and indirectly and produces gold for the local goldsmiths, among other benefits. Concomitant to their operations, ASSM causes significant environmental pollution with chemicals, predominantly mercury. Mercury is used by small scale miners in the processing of ore mined because it is relatively easy to use and readily available. The laws regulating small scale gold mining in Ghana do not forbid the use of mercury even though there is a loud outcry against the use of mercury in small scale gold mining. The operations have resulted in the discharge of mercury into the environment indiscriminately. No attempt is made by the miners to recover lost mercury hence all of it is lost to the environment. This paper presents the findings of a study that investigated the trajectory of the mercury lost into the environment. The results showed that 2 g of mercury was lost to the environment for every gram of gold recovered through ASSM; 39% of it was lost to the atmosphere due to roasting of the amalgam whilst the remaining 61% was lost into water and spillage onto the ground. Keywords: Mercury, Atmosphere, Pollution, Environment, Socio-economi

Effect of Continuous Infusion of Relaxin on Progesterone, Oxytocin, and Relaxin Blood Concentrations and Time of Parturition in Beef Heifers

These studies were designed to determine whether continuous intravenous infusion of increasing dosages of porcine relaxin during late pregnancy in beef heifers would influence circulating blood concentrations of relaxin, progesterone, and oxytocin, and time of onset of parturition. Beef heifers were bred by artificial insemination and, on Day 277, fitted with indwelling jugular cannulas for hormone infusion and blood sampling from Day 277 to 286. Intravenous infusion of purified porcine relaxin (pRLX, 3000 U mg-1) was started in heifers (n = 8) at increasing dosages (200 U h-1 on Days 277 and 278, 300 U h-1 on Days 279 and 280, 500 U h-1 on Day 281, 600 U h-1 on Day 282, and 700 U h-1 on Days 283 to 286). Phosphate buffer saline (PBS, 10 ml h-1) was infused during these same times to control (n = 6) animals. Relaxin treatment steadily increased the circulating plasma concentration of immunoreactive relaxin to more than 120 ng ml-1 compared with less than 0.5 ng ml-1 in PBStreated controls. Relaxin infusion in increasing dosages over the treatment time was associated with a significant decrease (P \u3c 0.01) in plasma progesterone concentration compared with the PBS controls. Plasma levels of oxytocin at 4- hour intervals remained similar (P \u3e 0.05) during the pretreatment period and throughout continuous infusion of pRLX and PBS. Although continuous intravenous infusion of relaxin resulted in a decrease in circulating blood levels of progesterone, it did not significantly reduce the interval between the beginning of pRLX treatment and parturition compared with the PBS-infused control heifers. These results indicate that continuous intravenous infusion of high levels of porcine relaxin resulted in a decrease in progesterone secretion in late pregnant beef heifers

Exploring Possible Humanoids on Mars: A Lesson Designed for Twice-Exceptional Gifted Students

This practical article presents a classroom-tested pedagogical plan to assist instructors in teaching thinking skills to gifted students with disabilities in the context of science. The lesson, which focused on using Edward de Bono thinking skills to explore humanoid images that appear in NASA photos, provided accommodations for students with hearing impairment, along with disabilities associated with short and long-term memory. The instructional design team presented the arts-integrated activity of drawing scenes showing possible ways the anomalies could have been generated, and an interactive electronic game using iPads that asked participants to gather needed items for a trip to Mars. High-achieving doctoral students, many of whom were identified as gifted during their K-12 schooling, participated in the lesson. Incorporation of electronic game technology along with creative arts-integrated activities was received positively and was an effective strategy to increase motivation, to sustain student’s engagement, and to attract and retain the directed attention of students, especially because of the social interaction

RegenBase: a knowledge base of spinal cord injury biology for translational research.

Spinal cord injury (SCI) research is a data-rich field that aims to identify the biological mechanisms resulting in loss of function and mobility after SCI, as well as develop therapies that promote recovery after injury. SCI experimental methods, data and domain knowledge are locked in the largely unstructured text of scientific publications, making large scale integration with existing bioinformatics resources and subsequent analysis infeasible. The lack of standard reporting for experiment variables and results also makes experiment replicability a significant challenge. To address these challenges, we have developed RegenBase, a knowledge base of SCI biology. RegenBase integrates curated literature-sourced facts and experimental details, raw assay data profiling the effect of compounds on enzyme activity and cell growth, and structured SCI domain knowledge in the form of the first ontology for SCI, using Semantic Web representation languages and frameworks. RegenBase uses consistent identifier schemes and data representations that enable automated linking among RegenBase statements and also to other biological databases and electronic resources. By querying RegenBase, we have identified novel biological hypotheses linking the effects of perturbagens to observed behavioral outcomes after SCI. RegenBase is publicly available for browsing, querying and download.Database URL:http://regenbase.org

In vitro Anti-proliferative and Apoptotic Activities of Eurycoma longifolia Jack (Simaroubaceae) on HL-60 Cell Line

Purpose: To investigate the anti-proliferative, apoptotic and differentiating activities of Eurycoma longifolia root extracts on HL-60 leukemic cells.Methods: HL-60 cells were treated with different partially purified sub-fractions (F1 – F3) derived from the resin chromatography of the crude methanol root extract of E. longifolia roots, at different doses andtime points. The anti-proliferative activity of E. longifolia was assessed via cell counting and trypan blue exclusion. Apoptosis was evaluated via Annexin-V FITC/IP and Hoechst staining. Flow cytometry and Wright staining were used to assess its differentiation activities.Results: F1 showed unremarkable growth inhibition rate while F2 and F3 showed growth inhibitory effects with median inhibitory concentration (IC50) values of 15.2 and 28.6 ìg/ml, respectively. Treatment with F2 and F3 (100 ìg/ml) for 96 h increased cell death from 3.3 to 95.5 and 76.3 %,respectively. Treatment with F2 (50 ìg/ml) induced apoptosis by 14, 19.5 and 25 % after 24, 48 and 72 h, respectively. No differentiation activity was observed, as indicated by absence of myeloid maturation and a non-significant CD14 positivity (p > 0.05).Conclusion: E. longifolia extract (F2) showed promising anti-leukemic activity and can be a candidate for the development of a drug for the treatment of acute promyelocytic leukemia (APL).Keywords: Acute promyelocytic leukemia (APL), HL-60 cells, Eurycoma longifolia, Apoptosis, Antiproliferation, Differentiatio

Robust and Skew-resistant Parallel Joins in Shared-Nothing Systems

The performance of joins in parallel database management systems is critical for data intensive operations such as querying. Since data skew is common in many applications, poorly engineered join operations result in load imbalance and performance bottlenecks. State-of-the-art methods designed to handle this problem offer significant improvements over naive implementations. However, performance could be further improved by removing the dependency on global skew knowledge and broadcasting. In this paper, we propose PRPQ (partial redistribution & partial query), an efficient and robust join algorithm for processing large-scale joins over distributed systems. We present the detailed implementation and a quantitative evaluation of our method. The experimental results demonstrate that the proposed PRPQ algorithm is indeed robust and scalable under a wide range of skew conditions. Specifically, compared to the state-of-art PRPD method, we achieve 16% - 167% performance improvement and 24% - 54% less network communication under different join workloads

Application of carbon nanotubes in cancer vaccines: Achievements, challenges and chances

Tumour-specific, immuno-based therapeutic interventions can be considered as safe and effective approaches for cancer therapy. Exploitation of nano-vaccinology to intensify the cancer vaccine potency may overcome the need for administration of high vaccine doses or additional adjuvants and therefore could be a more efficient approach. Carbon nanotube (CNT) can be described as carbon sheet(s) rolled up into a cylinder that is nanometers wide and nanometers to micrometers long. Stemming from the observed capacities of CNTs to enter various types of cells via diversified mechanisms utilising energy-dependent and/or passive routes of cell uptake, the use of CNTs for the delivery of therapeutic agents has drawn increasing interests over the last decade. Here we review the previous studies that demonstrated the possible benefits of these cylindrical nano-vectors as cancer vaccine delivery systems as well as the obstacles their clinical application is facing