Neutralisation treatment of AMD at affordable cost

Acid mine drainage (AMD) has for many years been a major environmental challenge associated with the mining industry, especially in the Eastern, Central and Western mining basins of Gauteng. The aims of this article are to: (i) demonstrate the suitability of the sequencing batch reactor (SBR) system for both neutralisation of free acid and removal of iron(II), often the main component in AMD, using limestone, the cheapest alkali, followed by lime treatment for removal of heavy metals, and partial sulphate removal through gypsum crystallisation; (ii) compare the alkali cost of the alternative SBR system where limestone and lime are used for treatment, with conventional lime treatment, and (iii) present the capital cost of the SBR system.The conclusions of this study are that: (i) precipitated calcium carbonate can be used for complete removal of iron(II) in an SBR system within 90 min reaction time; (ii) lime can be used for complete removal of heavy metals after pre-treatment with precipitated calcium carbonate; (iii) the alkali cost for treatment of AMD from the Western Basin will amount to R2.80/m3 in the case of limestone/lime treatment compared to R5.83/m3 if only lime is used; (iv) the alkali cost for treatment of 85 Mℓ/d acid mine water from both the Western and Central Basins will amount to R60 m./a in the case of limestone/lime treatment compared to R136.9 m./a if only lime is used; and (v) the capital cost for the SBR system amounts to R3.5 m. per Mℓ/d.Keywords: Acid mine drainage, sequencing batch reactor, neutralisation, limeston

Physical activity during school recess : a systematic review

Context: Interest has increased in examining the physical activity levels of young people during school recess. Identifying correlates of their recess physical activity behaviors is timely, and would inform school-based physical activity programming and intervention development. The review examined the correlates of children\u27s and adolescent\u27s physical activity during school recess periods. Evidence acquisition: Asystematicsearchofsixelectronicdatabases,referencelists,andpersonal archives identified 53 studies (47 focused on children) published between January 1990 and April 2011 that met the inclusion criteria. Data were analyzed in 2011. Correlates were categorized using the social-ecological framework. Evidence synthesis: Forty-four variables were identified across the four levels of the social- ecological framework, although few correlates were studied repeatedly at each level. Positive associ- ations were found of overall facility provision, unfixed equipment, and perceived encouragement with recess physical activity. Results revealed that boys were more active than girls. Conclusions: Providing access to school facilities, providing unfixed equipment, and identifying ways to promote encouragement for physical activity have the potential to inform strategies to increase physical activity levels during recess periods

Frequency of post-stroke pneumonia: Systematic review and meta-analysis of observational studies

Background: Post-stroke pneumonia and other infectious complications are serious conditions whose frequency varies widely across studies. Aims: We conducted a systematic review to estimate the frequency of post-stroke pneumonia and other types of major infection. Summary of review: MEDLINE, EMBASE, CINAHL, and PsycINFO databases were searched for prospective studies with consecutive recruitment of stroke patients. The primary outcome was post-stroke pneumonia. Secondary outcomes were any infection and urinary tract infection. Quality assessment was done using Newcastle Ottawa scale. Heterogeneity of estimates across study populations was calculated using Cochran's Q (heterogeneity χ2) and I2 statistics. A total of 47 studies (139,432 patients) with 48 sample populations were eligible for inclusion. Mean age of patients was 68.3 years and their mean National Institute of Health Stroke Scale score was 8.2. The pooled frequency of post-stroke pneumonia was 12.3% (95% confidence interval [CI] 11%–13.6%; I2 = 98%). The pooled frequency from 2011 to 2017 was 13.5% (95% CI 11.8%–15.3%; I2 = 98%) and comparable with earlier periods (P interaction = 0.31). The pooled frequency in studies in stroke units was 8% (95% CI 7.1%–9%; I2 = 78%) and significantly lower than other locations (P interaction = 0.001). The pooled frequency of post-stroke infection was 21% (95% CI 13%–29.3%; I2 = 99%) and of post-stroke urinary tract infection was 7.9% (95% CI 6.7%–9.3%; I2 = 96%). Conclusion: Approximately 1 in 10 stroke patients experience pneumonia during the acute period of hospital care. The frequency of post-stroke pneumonia has remained stable in recent decades but is lower in patients receiving stroke unit care compared to management in other ward settings

Propagation Failure in Excitable Media

We study a mechanism of pulse propagation failure in excitable media where stable traveling pulse solutions appear via a subcritical pitchfork bifurcation. The bifurcation plays a key role in that mechanism. Small perturbations, externally applied or from internal instabilities, may cause pulse propagation failure (wave breakup) provided the system is close enough to the bifurcation point. We derive relations showing how the pitchfork bifurcation is unfolded by weak curvature or advective field perturbations and use them to demonstrate wave breakup. We suggest that the recent observations of wave breakup in the Belousov-Zhabotinsky reaction induced either by an electric field or a transverse instability are manifestations of this mechanism.Comment: 8 pages. Aric Hagberg: http://cnls.lanl.gov/~aric; Ehud Meron:http://www.bgu.ac.il/BIDR/research/staff/meron.htm

Empirical Evaluation of Deep Learning Approaches for Landmark Detection in Fish Bioimages

In this paper we perform an empirical evaluation of variants of deep learning methods to automatically localize anatomical landmarks in bioimages of fishes acquired using different imaging modalities (microscopy and radiography). We compare two methodologies namely heatmap based regression and multivariate direct regression, and evaluate them in combination with several Convolutional Neural Network (CNN) architectures. Heatmap based regression approaches employ Gaussian or Exponential heatmap generation functions combined with CNNs to output the heatmaps corresponding to landmark locations whereas direct regression approaches output directly the (x, y) coordinates corresponding to landmark locations. In our experiments, we use two microscopy datasets of Zebrafish and Medaka fish and one radiography dataset of gilthead Seabream. On our three datasets, the heatmap approach with Exponential function and U-Net architecture performs better. Datasets and open-source code for training and prediction are made available to ease future landmark detection research and bioimaging applications

Cross-cultural agreement in facial attractiveness preferences : the role of ethnicity and gender

Previous work showed high agreement in facial attractiveness preferences within and across cultures. The aims of the current study were twofold. First, we tested cross-cultural agreement in the attractiveness judgements of White Scottish and Black South African students for own- and other-ethnicity faces. Results showed significant agreement between White Scottish and Black South African observers’ attractiveness judgements, providing further evidence of strong cross-cultural agreement in facial attractiveness preferences. Second, we tested whether cross-cultural agreement is influenced by the ethnicity and/or the gender of the target group. White Scottish and Black South African observers showed significantly higher agreement for Scottish than for African faces, presumably because both groups are familiar with White European facial features, but the Scottish group are less familiar with Black African facial features. Further work investigating this discordance in cross-cultural attractiveness preferences for African faces show that Black South African observers rely more heavily on colour cues when judging African female faces for attractiveness, while White Scottish observers rely more heavily on shape cues. Results also show higher cross-cultural agreement for female, compared to male faces, albeit not significantly higher. The findings shed new light on the factors that influence cross-cultural agreement in attractiveness preferences.VC was supported by a South African National Research Foundation Scarce Skills Postdoctoral Fellowship (Grant nr: 76454).http://www.plosone.orgam201

Temporal proteomic profiling of postnatal human cortical development.

Healthy cortical development depends on precise regulation of transcription and translation. However, the dynamics of how proteins are expressed, function and interact across postnatal human cortical development remain poorly understood. We surveyed the proteomic landscape of 69 dorsolateral prefrontal cortex samples across seven stages of postnatal life and integrated these data with paired transcriptome data. We detected 911 proteins by liquid chromatography-mass spectrometry, and 83 were significantly associated with postnatal age (FDR < 5%). Network analysis identified three modules of co-regulated proteins correlated with age, including two modules with increasing expression involved in gliogenesis and NADH metabolism and one neurogenesis-related module with decreasing expression throughout development. Integration with paired transcriptome data revealed that these age-related protein modules overlapped with RNA modules and displayed collinear developmental trajectories. Importantly, RNA expression profiles that are dynamically regulated throughout cortical development display tighter correlations with their respective translated protein expression compared to those RNA profiles that are not. Moreover, the correspondence between RNA and protein expression significantly decreases as a function of cortical aging, especially for genes involved in myelination and cytoskeleton organization. Finally, we used this data resource to elucidate the functional impact of genetic risk loci for intellectual disability, converging on gliogenesis, myelination and ATP-metabolism modules in the proteome and transcriptome. We share all data in an interactive, searchable companion website. Collectively, our findings reveal dynamic aspects of protein regulation and provide new insights into brain development, maturation, and disease

Current developments in MRI for assessing rodent models of multiple sclerosis

MRI is a key radiological imaging technique that plays an important role in the diagnosis and characterization of heterogeneous multiple sclerosis (MS) lesions. Various MRI methodologies such as conventional T 1/T 2 contrast, contrast agent enhancement, diffusion-weighted imaging, magnetization transfer imaging and susceptibility weighted imaging have been developed to determine the severity of MS pathology, including demyelination/remyelination and brain connectivity impairment from axonal loss. The broad spectrum of MS pathology manifests in diverse patient MRI presentations and affects the accuracy of patient diagnosis. To study specific pathological aspects of the disease, rodent models such as experimental autoimmune encephalomyelitis, virus-induced and toxin-induced demyelination have been developed. This review aims to present key developments in MRI methodology for better characterization of rodent models of MS