Spatiotemporal analysis of droughts using self-calibrating Palmer’s Drought Severity Index in the central region of South Africa

Published ArticleThe loss of life and property from drought events has forced society to focus on the development of reliable early warning systems which may enable farmers and other stakeholders to correctly and timely adapt to the expected impacts of climatic hazard. However, a scientific approach to a reliable early warning system for a region requires, among others, characterisation of drought events in the region in terms of duration, magnitude, intensity and frequency using standard drought indices. Therefore, the objective of this study was to identify and characterise drought events in the Modder River basin, central region of South Africa, using a self-calibrated Palmer’s Drought Severity Index (sc-PDSI). Attempts were also made to establish a relationship between meteorological and hydrological drought events in the region. During the period of analysis, the total number of drought episodes identified in the study area ranged between eight and sixteen. It was found that the most severe drought episodes occurred during the period 1992–1995 followed by the period 1982–1987. Results of analysis of seasonal drought events in one of the quaternary catchments (C52A) revealed that peak drought events during the three summer months (November, December and January) occurred in the area in 1993. However, in terms of event magnitude and intensity, the worst drought events were recorded during the period December 1982–July 1987, followed by the event that ensued during December 1989–September 1995. Results of analysis of decadal variation of drought events showed that the number of extreme and moderate drought events recorded in the catchment showed statistically significant increasing trends during the five decades at 5 % significance level. Moreover, spectral analysis of sc-PDSI time series in the region identified periodicities in the time series ranging from 6 years (C52E) to 16 years (C52K). In terms of the spatial extent of extreme drought events, the maximum areal coverage (91 %) was recorded in November 1998, followed by December 1998 and December–January 1999 (43 %). Analysis of the relative frequency of droughts of varying categories revealed that extreme drought events were most prevalent in the C52E (2.72 %) quaternary catchment, followed by C52C (2.21 %). The study also found an average lag time of 10 months between the onsets of meteorological and hydrological drought events in the region

Perspectives of Protocol Based Breaking Bad News among Medical Patients and Physicians in a Teaching Hospital, Ethiopia

BACKGROUND፡ Discussing potentially bad outcomes is a standard communication task in clinical care. Physicians’ awareness on ways to communicate bad news is considered low. SPIKES protocol is the most popular strategy used by physicians, but its practice and patients' perception are not known. This study attempted to fill the knowledge gap on protocol implementation, patient preference and physician effects.METHODS: Hospital-based descriptive cross-sectional study was conducted at SPHMMC from May 1 to June 30 using structured interviews administered to patients and physicians. Three hundred and sixty patients and 111 physicians were included. Assessment of SPIKES performance, patient satisfaction, patient preference, and physician awareness, attitude and effects were studied.RESULTS: Performance of SPIKES protocol was setting (74.5%), perception (51.1%), invitation (56.3%), knowledge (15.9%), emotion (22.3%) and summary (10.1%). Only 30.6% of the patients were entirely satisfied with the interaction, and 19.2% with knowledge attained. Patient satisfaction was associated with physician asking how much information they like (P=0.025). Patient desire and report showed variation. Eighty-two percent of the physicians were not aware of the protocol, and 83.8% had no training. Half of the physicians feel depressed after disclosure.CONCLUSIONS: Patient satisfaction with communication process and knowledge is poor, as is performance of SPIKES components. Satisfaction is related to being asked how much patients want to know. Patients’ desires on how to be told news is different from how it is done. Breaking bad news increases feeling of depression. Awareness and training on the protocol are deficient; medical schools should incorporate it into their studies and implement proper follow-up.&nbsp

Internal Corrosion Damage Mechanisms of the Underground Water Pipelines

Internal water pipe corrosion is a complicated problem due to the interaction of water quality parameters with pipe wall. This study presents investigations of internal pipe surface corrosion mechanisms related to water physicochemical. Samples of water and corrosion-damaged ductile cast iron (30+ years) and galvanized steel pipe (15-20 years) were collected at in-situ condition from Addis Ababa city water distribution system. Scanning electron microscopy and optical microscopy were used to examine the pipes' corrosion morphology and microstructures, respectively. Additionally, Mountains 9 surface analysis software was used for further pitting corrosion characterization.To identify the causes of internal pipe corrosion, water physicochemical analyses were conducted by using inoLab pH 7310P, DR 900, Palintest Photometer 7100, and Miero 800. Water physicochemical test indicates: CaCO3 is 77 - 215 ppm, pH is 7.05 – 7.86, total dissolved solids (TDS) is 84.10 -262.8 ppm, ClO2 is 0 – 0.5 ppm, and dissolved oxygen (80-81 ppb). From water test results, major causes of internal pipe corrosion damage mechanisms were identified as dissolved oxygen, CaCO3, TDS, ClO2,and resistivity of water which initiates a differential cell that accelerates pipe corrosion. Using Mountain 9 surface analysis software, corrosion morphology and pitting features were characterized. The outputs of this paper will be helpful for water distribution and buried infrastructure owners to investigate corrosion damage mechanisms at early stage. To manage corrosion mechanisms, water supply owners need to conduct frequent inspections, recording of pipe data, testing of water quality, periodic pipelines washing, and apply preventative maintenance.publishedVersio

Physiologically Based Pharmacokinetic Modeling of Nanoceria Systemic Distribution in Rats Suggests Dose- and Route-Dependent Biokinetics

Background: Cerium dioxide nanoparticles (nanoceria) are increasingly being used in a variety of products as catalysts, coatings, and polishing agents. Furthermore, their antioxidant properties make nanoceria potential candidates for biomedical applications. To predict and avoid toxicity, information about their biokinetics is essential. A useful tool to explore such associations between exposure and internal target dose is physiologically based pharmacokinetic (PBPK) modeling. The aim of this study was to test the appropriateness of our previously published PBPK model developed for intravenous (IV) administration when applied to various sizes of nanoceria and to exposure routes relevant for humans. Methods: Experimental biokinetic data on nanoceria (obtained from various exposure routes, sizes, coatings, doses, and tissues sampled) in rats were collected from the literature and also obtained from the researchers. The PBPK model was first calibrated and validated against IV data for 30 nm citrate coated ceria and then recalibrated for 5 nm ceria. Finally, the model was modified and tested against inhalation, intratracheal (IT) instillation, and oral nanoceria data. Results: The PBPK model adequately described nanoceria time courses in various tissues for 5 nm ceria given IV. The time courses of 30 nm ceria were reasonably well predicted for liver and spleen, whereas the biokinetics in other tissues were not well captured. For the inhalation, IT instillation, and oral exposure routes, re-optimization was difficult due to low absorption and, hence, low and variable nanoceria tissue levels. Moreover, the nanoceria properties and exposure conditions varied widely among the inhalation, IT instillation, and oral studies, making it difficult to assess the importance of different factors. Conclusion: Overall, our modeling efforts suggest that nanoceria biokinetics depend largely on the exposure route and dose

Dataset for SERS plasmonic array: Width, spacing, and thin film oxide thickness optimization

Surface-enhanced Raman spectroscopy (SERS) improves the scope and power of Raman spectroscopy by taking advantage of plasmonic nanostructures, which have the potential to enhance Raman signal strength by several orders of magnitude, which can allow for the detection of analyte molecules. The dataset presented provides results of a computational study that used a finite element method (FEM) to model gold nanowires on a silicon dioxide substrate. The survey calculated the surface average of optical surface enhancement due to plasmonic effects across the entire model and studied various geometric parameters regarding the width of the nanowires, spacing between the nanowires, and thickness of the silicon dioxide substrate. From this data, enhancement values were found to have a periodicity due to the thickness of the silicon dioxide. Additionally, strong plasmonic enhancement for smaller distances between nanowires were found, as expected; however, additional surface enhancement at greater gap distances were observed, which were not anticipated, possibly due to resonance with periodic dimensions and the frequency of the light. This data presentation will benefit future SERS studies by probing further into the computational and mathematical material presented previously

Role of ADAM10 and ADAM17 in the Regulation of Keratinocyte Adhesion in Pemphigus Vulgaris

The severe autoimmune blistering disease Pemphigus vulgaris (PV) is mainly caused by autoantibodies (IgG) against desmoglein (Dsg) 3 and Dsg1. The mechanisms leading to the development of blisters are not fully understood, but intracellular signaling seems to play an important role. Sheddases ADAM10 and ADAM17 are involved in the turnover of the desmosomal cadherin Dsg2 and ADAM10 has been shown to contribute to acantholysis in a murine pemphigus model. In the present study, we further examined the role of ADAM10 and ADAM17 both in keratinocyte adhesion and in the pathogenesis of PV. First, we found that inhibition of ADAM10 enhanced adhesion of primary human keratinocytes but not of immortalized keratinocytes. In dissociation assays, inhibition of ADAM10 shifted keratinocyte adhesion towards a hyperadhesive state. However, ADAM inhibition did neither modulate protein levels of Dsg1 and Dsg3 nor activation of EGFR at Y1068 and Y845. In primary human keratinocytes, inhibition of ADAM10, but not ADAM17, reduced loss of cell adhesion and fragmentation of Dsg1 and Dsg3 immunostaining in response to a PV1-IgG from a mucocutaneous PV patient. Similarly, inhibition of ADAM10 in dissociation assay decreased fragmentation of primary keratinocytes induced by a monoclonal antibody against Dsg3 and by PV-IgG from two other patients both suffering from mucosal PV. However, such protective effect was not observed in both cultured cells and ex vivo disease models, when another mucocutaneous PV4-IgG containing more Dsg1 autoantibodies was used. Taken together, ADAM10 modulates both hyperadhesion and PV-IgG-induced loss of cell adhesion dependent on the autoantibody profile