Geotechnical Evaluation of a Ghanaian Black Cotton Soil for use as Clay Liner in Tailings Dam Construction

The purpose of tailings impoundment is to contain tailings produced from mineral processing. Chemicals used in mineral ex-traction processes are usually hazardous to biota and fauna and their presence in tailings may pollute the environment. To pre-vent the flow of such contaminants from tailing dams into the environment, low permeability membranes or seals are used in the basin of the tailings dam as barrier layer. Geomembranes and natural clay liners are typical examples. The use of naturally occurring clay materials provides the most economical liner for tailings dam construction. Lateritic clay and weathered shale have been evaluated for use as liner. Black cotton soils occur in substantial quantities in parts of Ghana but their potential use as a clay liner has not been evaluated. This study presents laboratory evaluation of a typical black cotton soil from the Accra plains of Ghana as potential clay liner for tailings dam construction. Results of the study indicate that the hydraulic conductiv-ity or permeability, plasticity index, fines content and cation exchange capacity of the black cotton soils met the specification of typical clay liner systems. The soil however failed the specific gravity and liquid limit requirements marginally and hence, the soils may be used as clay lining system in tailings dams

Green tea (Camellia sinensis) aqueous extract improved human spermatozoa functions in vitro

Background: Idiopathic causes of infertility is associated with oxidative stress. Antioxidants are known to scavenge the excessive production of reactive oxygen species (ROS). Green tea (Camellia sinensis) contains polyphenols that enhance its antioxidant potential. Aim: This study focused on the impact of aqueous green tea extract on normozoospermic human spermatozoa. Setting: Department of Medical Biosciences, University of the Western Cape (UWC), South Africa. Methods: Semen samples obtained using masturbation method following three to five days of sexual abstinence from consenting men (n = 59) at the University of the Western Cape (UWC) were liquefied and analysed. Normozoospermic samples were selected according to the World Health Organization (WHO) 5th guideline. Thereafter, semen samples (7.5 × 106 /mL) were washed in human tubular fluid (HTF; 10 min at 300 ×g) and exposed to aqueous extracts of green tea (0 μg/mL, 0.4 μg/mL, 4 μg/mL, 40 μg/mL, 405 μg/mL) for 1 h with various sperm parameters analyzed. Human tubular fluid supplemented with bovine serum albumin (HTF-BSA; 10%) served as control. Results: Sperm motility, reactive oxygen species production, across some reaction and deoxyribonucleic acid (DNA) fragmentation decreased significantly, particularly at the highest concentration (405 μg/mL; p < 0.001). A substantial increase in the percentage of viable spermatozoa and those with intact mitochondrial membrane potential (MMP) were observed (p < 0.001). Conclusion: Aqueous extract of green tea prolonged sperm viability and MMP while reducing sperm intracellular ROS production, capacitation and across some reaction and DNA fragmentation, and may be attributed to its antioxidant potential. However, a high concentration of the extract appears to be detrimental to the functioning of human spermatozoa

Micellar effect on metal-ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with citric acid

Chemical speciation of citric acid complexes of Co(II), Ni(II), Cu(II) and Zn(II) was investigated pH-metrically in 0.0-2.5% anionic, cationic and neutral micellar media. The primary alkalimetric data were pruned with SCPHD program. The existence of different binary species was established from modeling studies using the computer program MINIQUAD75. Alkalimetric titrations were carried out in different relative concentrations (M:L:X = 1:2:5, 1:3:5, 1:5:3) of metal (M) to citric acid. The selection of best chemical models was based on statistical parameters and residual analysis. The species detected were MLH, ML2, ML2H and ML2H2. The trend in variation of stability constants with change in mole fraction of the medium is explained onthe basis of electrostatic and non-electrostatic forces. Distributions of the species with pH at different compositions of micellar media are also presented

Prevalence and Antibiotic Susceptibility Pattern of E. coli Isolated from Urinary Tract Infection in Patients with Renal Failure Disease and Renal Transplant Recipients

Purpose: To determine the common uropathogens found in patients with urinary tract infections and to assess their antibiotic susceptibility patterns.Methods: The prevalence and antibiotic susceptibility pattern of E. coli in urinary tract infection inpatients with renal failure disease and renal transplant recipients (group 1) and in outpatients (group 2), admitted in/attending Imam Reza Hospital in Tabriz, Iran, were determined. Isolates were analyzed by standard methods, and antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method.Results: A total of 136 E. coli strains from 81 females and 55 males were examined. The high level of antibiotic susceptibility for group 1 was cefuroxime/ceftazidime (100 %) and nitrofurantoin (81.63 %), respectively; and for group 2, it was ampicillin (95.83 %) and nitrofurantoin (93.75 %), respectively.Conclusion: The most important finding of this study is that a considerable proportion of the studied E. coli isolates are resistant to the antibiotics tested, except nitrofurantoin. This finding is useful for clinicians to determine appropriate empirical antimicrobial treatment in similar cases and would also help health authorities to formulate antibiotic prescription policies.Keywords: Urinary tract infection, Antibiotic susceptibility pattern, Uropathogens, Renal failure, Renal transplant, Escherichia col

Variation in methods, results and reporting in electronic health record-based studies evaluating routine care in gout: A systematic review

Objective: To perform a systematic review examining the variation in methods, results, reporting and risk of bias in electronic health record (EHR)-based studies evaluating management of a common musculoskeletal disease, gout. Methods: Two reviewers systematically searched MEDLINE, Scopus, Web of Science, CINAHL, PubMed, EMBASE and Google Scholar for all EHR-based studies published by February 2019 investigating gout pharmacological treatment. Information was extracted on study design, eligibility criteria, definitions, medication usage, effectiveness and safety data, comprehensiveness of reporting (RECORD), and Cochrane risk of bias (registered PROSPERO CRD42017065195). Results: We screened 5,603 titles/abstracts, 613 full-texts and selected 75 studies including 1.9M gout patients. Gout diagnosis was defined in 26 ways across the studies, most commonly using a single diagnostic code (n = 31, 41.3%). 48.4% did not specify a disease-free period before ‘incident’ diagnosis. Medication use was suboptimal and varied with disease definition while results regarding effectiveness and safety were broadly similar across studies despite variability in inclusion criteria. Comprehensiveness of reporting was variable, ranging from 73% (55/75) appropriately discussing the limitations of EHR data use, to 5% (4/75) reporting on key data cleaning steps. Risk of bias was generally low. Conclusion: The wide variation in case definitions and medication-related analysis among EHR-based studies has implications for reported medication use. This is amplified by variable reporting comprehensiveness and the limited consideration of EHR-relevant biases (e.g. data adequacy) in study assessment tools. We recommend accounting for these biases and performing a sensitivity analysis on case definitions, and suggest changes to assessment tools to foster this

Uso do Propofol associado a Metadona e bloqueio local com LidocaínA em seis exemplares de Potamotrygon sp.

Fish make up the group of vertebrates with the greatest diversity, and their main characteristic is their aquatic habitat, with primary respiration through gills and ectothermy. The Potamotrygonidae family is an example of cartilaginous fish that includes freshwater rays belonging to South America. As they are restricted to fresh life, they have anatomophysiological particularities that differentiate them from other elasmobranchs. Potamotrygon is the most diverse genus, and although they are not aggressive fish, stingrays of this genus have a retro-serrated sting covered by a venom-producing glandular epithelium. Aiming at the safety of many fish that are protected, and of those responsible for management, this work aims to report the anesthetic protocol for iron resection from six stingrays of the genus Potamotrygon. Six specimens of stingray were sent to the Veterinary Hospital of the Federal University of Uberlândia (HVET-UFU), three of the species Potamotrygon falkneri and three Potamotrygon leopoldi for surgical removal of sting. The anesthetic protocol consisted of methadone induction of anesthesia with propofol in the spiracles, and local blockade with lidocaine without vasoconstrictor. Trans-anesthetic monitoring was performed regarding water temperature, respiratory rate, and heart rate of the animals. All animals were recovered under anesthesia within five minutes, and no complications were recorded. Although the anesthesiology of elasmobranch fish is still an uncertain area due to the scarcity of experimental models, the launched protocol presented extraordinary results for promoting relaxation, analgesia and rapid recovery.Pesquisa sem auxílio de agências de fomentoOs peixes compõem o grupo de vertebrados de maior diversidade, e possuem como principal característica o hábitat aquático, com respiração primária através das brânquias, e ectotermia. A família Potamotrygonidae é um exemplo de peixes cartilaginosos que engloba as raias de água doce pertencentes à América do Sul. Por serem restritas à vida dulcícola, possuem particularidades anatomofisiológicas que as diferenciam dos demais elasmobrânquios. Potamotrygon é o gênero mais diverso, e embora não sejam peixes agressivos, as arraias deste gênero possuem um ferrão retro-serrilhado coberto por um epitélio glandular produtor de peçonha. Visando a segurança de demais peixes que compartilham o aquário, e do responsável pelo manejo, este trabalho objetivou relatar o protocolo anestésico para ressecção do ferrão de seis arraias do gênero Potamotrygon. Foram encaminhadas para o Hospital Veterinário da Universidade Federal de Uberlândia (HVET-UFU) seis exemplares de arraia, sendo três da espécie Potamotrygon falkneri e três Potamotrygon leopoldi para remoção cirúrgica de ferrão. O protocolo anestésico foi composto por metadona indução anestésica com propofol nos espiráculos, e bloqueio local com lidocaína sem vasoconstritor. A monitorização trans-anestésica foi realizada quanto à temperatura da água, frequência respiratória, e a frequência cardíaca dos animais. Todos os animais apresentaram recuperação anestésica em até cinco minutos, e não foram registradas intercorrências. Embora a anestesiologia de peixes elasmobrânquios ainda seja uma área incerta devido à escassez de modelos experimentais, o protocolo empregado apresentou resultados satisfatórios para promover relaxamento, analgesia e rápida recuperação

Heterogeneous impacts of mobility restrictions on air quality in the State of Sao Paulo during the COVID-19 pandemic

Air quality in the State of Sao Paulo was evaluated during the first general State plan of mobility restrictions due to the COVID-19 pandemic (24th March to May 31, 2020). Nitrogen dioxide (NO2), ozone (O-3), particulate matter PM10 and PM2.5 and sulphur dioxide (SO2) concentrations were assessed in cities of the Sao Paulo State with a monitoring station and compared to historical data. Linear regression models were built to investigate the relationship between the isolation of the population - determined using mobile phone monitoring data - and the concentration of each pollutant during the studied period. Although the reduction of pollutants such as NO2, SO2 and PM2.5 is very clear, the economic and climatic characteristics of each region were decisive in the general behaviour of O-3 and PM10. It was not possible to establish a correlation between the pollutants and the isolation index, partly due to the lack of data, partly due to the compliance of the population to those measurements, which was variable over time. Another important limitation factor was the absence of data related to the pollutants of interest in many of the stations. However, the isolation measures carried out in the State opened the opportunity to individually assess the air quality measurements in each of the stations, enabling an understanding that will allow in the future the design of air quality policies together with local sanitary policies

Basal topographic controls on rapid retreat of Humboldt Glacier, northern Greenland

This is the final version of the article. Available from CUP via the DOI in this record.Discharge from marine-terminating outlet glaciers accounts for up to half the recent mass loss from the Greenland ice sheet, yet the causal factors are not fully understood. Here we assess the factors controlling the behaviour of Humboldt Glacier (HG), allowing us to evaluate the influence of basal topography on outlet glacier response to external forcing since part of HG’s terminus occupies a large overdeepening. HG’s retreat accelerated dramatically after 1999, coinciding with summer atmospheric warming of up to 0.19°C a–1 and sea-ice decline. Retreat was an order of magnitude greater in the northern section of the terminus, underlain by a major basal trough, than in the southern section, where the bedrock is comparatively shallow. Velocity change following retreat was spatially non-uniform, potentially due to a pinning point near HG’s northern lateral margin. Consistent with observations, numerical modelling demonstrates an order-of-magnitude greater sensitivity to sea-ice buttressing and crevasse depth (used as a proxy for atmospheric warming) in the northern section. The trough extends up to 72 km inland, so it is likely to facilitate sustained retreat and ice loss from HG during the 21st century.Funding for this work was provided by a Durham Doctoral Studentship to J.R.C. Radio-echo sounding data were acquired and processed through UK Natural Environment Research Council (NERC) grant NE/H020667 to J.A.D. and P.C. and a G. Unger Vetlesen grant to the University of Texas Institute for Geophysics (UTIG). GrOGG laser altimetry was supported by NNXAD33G to D.D.B. This paper is UTIG contribution No. 2733. S.S.R.J. was supported by UK NERC fellowship NE/J018333/1