A guide to the coding of occupations in South Africa

Human Sciences Research Counci

Development of a new alkali-activated binder incorporating dredged sediments

Alkali activated materials (AAMs) are known to be alternative binders to Ordinary Portland Cement (OPC) since the latter has the disadvantage of emitting large amounts of CO2 during its manufacture. Indeed, industrial by-products such as blast furnace slag (BFS) have been the main precursors in the alkali-activation reactions. On the other hand, dredging operations in the marine ports result in the formation of large volumes of sediment. In Europe, 100-200 Mm3 of sediment are dredged annually, and future regulations tend to restrict their immersion at the sea. The valorisation of a part of these sediments as raw materials in the composition of binders would contribute to limit the depletion of natural resources. So the aim of this work is oriented towards the development of a new type of alkali-activated mineral binder, based on blast furnace slag, incorporating dredged sediments. This study aims to assess the effects of sedimentary additions on the properties of the new binder. Parameters affecting the alkali-activation of BFS were fixed (nature of the activator: a solution of Na2SiO3 and NaOH with 5% Na2O and an activator modulus Ms equals to 1.45, while the Water/Solid ratio is set at 0.45). Then, variable percentages of sediments between 0 and 30% were incorporated into the studied formulations of the alkali-activated materials (MAAs), while W/S varied in order to maintain a constant workability. The effects of these sedimentary additions on the properties of the obtained material were studie

Factors associated with spontaneous clearance of chronic hepatitis C virus infection

Background & Aims: Spontaneous clearance of chronic hepatitis C virus (HCV) infection (CHC) is rare. We conducted a retrospective case-control study to identify rates and factors associated with spontaneous clearance of CHC. Methods: We defined cases as individuals who spontaneously resolved CHC, and controls as individuals who remained chronically infected. We used data obtained on HCV testing between 1994 and 2013 in the West of Scotland to infer case/control status. Specifically, untreated patients with ⩾2 sequential samples positive for HCV RNA ⩾6 months apart followed by ⩾1 negative test, and those with ⩾2 positive samples ⩾6 months apart with no subsequent negative samples were identified. Control patients were randomly selected from the second group (4/patient of interest). Case notes were reviewed and patient characteristics obtained. Results: 25,113 samples were positive for HCV RNA, relating to 10,318 patients. 50 cases of late spontaneous clearance were identified, contributing 241 person-years follow-up. 2,518 untreated, chronically infected controls were identified, contributing 13,766 person-years follow-up, from whom 200 controls were randomly selected. The incidence rate of spontaneous clearance was 0.36/100 person-years follow-up, occurring after a median 50 months’ infection. Spontaneous clearance was positively associated with female gender, younger age at infection, lower HCV RNA load and co-infection with hepatitis B virus. It was negatively associated with current intravenous drug use. Conclusions: Spontaneous clearance of CHC occurs infrequently but is associated with identifiable host and viral factors. More frequent HCV RNA monitoring may be appropriate in selected patient groups. Lay summary: Clearance of hepatitis C virus infection without treatment occurs rarely once chronic infection has been established. We interrogated a large Scottish patient cohort and found that it was more common in females, patients infected at a younger age or with lower levels of HCV in the blood, and patients co-infected with hepatitis B virus. Patients who injected drugs were less likely to spontaneously clear chronic infection

Predictors of disease progression and outcome in chronic hepatitis C virus infection

Chronic HCV infection (CHC) is a significant cause of both liver related and non-liver related morbidity and mortality worldwide. Disease progression through to cirrhosis and hepatocellular carcinoma is highly variable, and once chronicity of infection has been established, the likelihood of spontaneous clearance without antiviral treatment is extremely low. Safe and highly effective oral antiviral therapy is now available for the treatment of CHC, however price and accessibility may limit the global use of these agents. Furthermore, concerns have been raised regarding the incidence of hepatocellular carcinoma in HCV-infected individuals receiving oral antiviral regimens, and there appears to be a ‘point of no return’ beyond which cirrhotic HCV-infected individuals fail to benefit from antiviral treatment. Thus, there remain a number of unanswered questions on the natural history of HCV infection. Ageing of the immune system, or immunosenescence, appears to contribute to poorer clinical and treatment outcomes, however robust, non-invasive, clinically relevant biomarkers are lacking. MicroRNAs (miRNAs) are short, endogenous non-coding RNAs responsible for post-transcriptional control of host gene expression. Specific patterns of miRNA deregulation have been described in the serum, liver tissue and peripheral immune cells of HCV-infected subjects, and it is hypothesised that they may be suitable as both diagnostic and prognostic biomarkers. We interrogated 3 patient cohorts (providing access to local and national clinical data) to identify patient factors associated with disease progression and both spontaneous and treatment-associated clearance of CHC. We found that chronological age and elevated BMI had the strongest association with hepatic cirrhosis. Co-morbid type 2 diabetes mellitus was associated with poor clinical outcomes during antiviral therapy. Spontaneous clearance of CHC occurred rarely (0.36 per 100 person-years follow up), and was associated with female gender, earlier age at infection, low HCV viral load and co-infection with HBV. Current injecting drug use was negatively associated with spontaneous clearance. We also explored the use of miRNAs as biomarkers in these cohorts. We correlated miRNA expression with cellular markers of immunosenescence to identify novel prognostic biomarkers for disease outcomes in CHC. Our findings demonstrated that CHC was associated with a distinct miRNA signature in the serum and peripheral immune cells. Serum miR-21-5p, miR-122-5p and miR-885-5p levels correlated with the expression of previously described biomarkers of ageing, however these miRNAs performed poorly as biomarkers of cirrhosis in CHC. Elevated serum miR-21-5p expression was an independent predictor of virologic relapse following antiviral therapy, together with HCV genotype. MiR-21-5p also appeared to predict the likelihood of an adverse clinical event during treatment. We identified a further microRNA, miR-345-5p, elevated baseline expression of which correlated with negative clinical outcome during treatment, and was associated with the presence of both hepatic and extra-hepatic malignancy. We explored the regulation of miRNA expression in an in vitro model, and found that interferon-stimulated gene expression is necessary for IFN-induced miR-21-5p expression. Finally, we performed pathway analysis for target genes regulated by miRNAs deregulated during CHC, and found that pathways in cancer were highly enriched. Pathway enrichment was similar between HCV-infected cirrhotic subjects and non-cirrhotic, immunosenescent subjects, suggesting that non-cirrhotic individuals with elevated biomarkers of immunosenescence may be at an increased risk of hepatocellular carcinoma and may benefit from enhanced surveillance and prioritisation for antiviral treatment. Overall, the wealth of clinical and molecular data provided the opportunity to explore possibilities for integrating novel biomarkers into clinical decision-making for monitoring liver-related disease in HCV-infected subjects

Is phytoextraction a suitable green treatment for metal-contaminated sediments ?

International audienceThe cleaning of waterways by regular dredging generates great volumes of sediments and, owing to human activities, these sediments often contain large amounts of metals. These materials are usually spread on landfill sites. Phytoremediation could be a stategy for the reclamation of these polluted sediments. To our knowledge, phytoextraction with hyperaccumulating plants has been few tested on contaminated sediment. This work focuses on the mechanisms of Cd accumulation in Arabidopsis halleri, a Cd and Zn hyperaccumulator, and the effects of this species on a metal polluted sediment

Guideline on the design and conduct of cystic fibrosis clinical trials: the European Cystic Fibrosis Society-Clinical Trials Network (ECFS-CTN).

We describe the rationale for disease specific research networks in general as well as the aims and function of the European Cystic Fibrosis Society-Clinical Trials Network (ECFS-CTN) specifically. The ECFS-CTN was founded in 2009 with the aim of improving the quality and quantity of clinical research in the area of cystic fibrosis (CF) in Europe. A network of 18 clinical trial sites in 8 European countries was established according to uniform state-of-the-art quality criteria. To support the ECFS-CTN in the acquisition, planning and conduct of clinical trials, the network is equipped with a coordinating centre, steering and executive committees, and committees for protocol review, standardization, training and networking as well as a data safety monitoring board. A strong partnership with European CF patient parent organizations aims to increase awareness of the need for efficient clinical research and the participation of patients in clinical trials

Low-Wavelengths SOI CMOS Photosensors for Biomedical Applications

INTRODUCTION : Biological agents may be characterized (in terms of quantity (or concentration), purity, nature) using optical ways like spectrometry, fluorometry and real-time PCR for example. Most of these techniques are based on absorbance or fluorescence. Indeed, many biological molecules can absorb the light when excited at wavelengths close to blue and ultraviolet (UV). For example, DNA, RNA and proteins feature an absorption peak in the deep UV, more precisely around 260 and 280 nm (Karczemska & Sokolowska, 2001). This work is widely focused on those wavelengths. A biological sample concentration measurement method can be based on UV light absorbance or transmittance, as already known and realized with high-cost and large-size biomedical apparatus. But, often, the difficulties come from the limitation for measuring very small concentrations (close to a few ng/µL or lower) since the measurement of such small light intensity variations at those low wavelengths requires a precise light source, and very efficient photodetectors. Reducing the dimensions of such a characterization system further requires a small light source, a miniaturized photosensor and a processing system with high precision to reduce the measurement variations. Some light-emitting diodes (LED) performing at those UV wavelengths have recently appeared and may be used to implement the light source. Concerning the optical sensor, while accurate but high-cost photosensors in technologies such as AlGaN and SiC provide high sensitivities in UV low wavelengths thanks to their semiconductor bandgap (Yotter & Wilson, 2003), the silicon-on-insulator (SOI) layers absorb the photons in that specific range thanks to an appropriate thickness of the silicon. Adding excellent performances of low power consumption, good temperature behavior and high speed (Flandre et al., 1999; 2001), the SOI technology allows the designers for integrating a specific signal processing integrated CMOS circuit to transform the photocurrent into a digital signal for example. This opens the possibility to build a low-cost, complete and portable microsystem, including the light source, the photodetector and a recipient for the sample to characterize […