Short-Term Water Use Dynamics in Drainage Lysimeters

Turfgrass water use (seasonal turfET) and crop coefficients were determined and a mathematical soil-water balance model for non-weighing drainage lysimeters, which simulates the occurrence (timing and amount) of drainage, was developed. Pairs of non-weighing drainage lysimeters were used to determine crop coefficients for turfgrass in four locations in the state of Utah: Logan Golf and Country Club, Murray Golf Course, Brigham Young University (Spanish Fork) Experiment Farm, and Sunbrook Golf Course (St. George). Daily weather data including air temperature, relative humidity, average wind travel, total solar radiation, precipitation, and average soil temperature were collected with an electronic weather station at each site. Daily precipitation was measured in three sites throughout the season: Murray, Spanish Fork, and Sunbrook. At Logan Golf and Country Club, precipitation was measured to November 10,2002. Water use (averages of two lysimeters) during the growing season varied from 684 to 732 mm for three years (2000- 2002) for the mid-April through late-October observation period at Logan Golf Course; 699 mm for May through October at Murray; 469 mm at Spanish Fork; and 896 mm for late-February through early November at Sunbrook, for 2002 growing season. Calculated seasonal Etr using the 82 Kimberly Penman equation with a 1 00-miles-per-day wind travel limit varied from 1166 to 1229 mm at Logan Golf and Country Club, 1067 mm at Murray, 839 mm at Spanish Fork, and 1574 mm at Sunbrook. Seasonal Etr calculated using the PM ASCE std Etr equation was greater than the 82 Kimberly Peru11an . Seasonal Eto calculated using the FAO#56 Eto equation was less than both the 82 Kimberly Penman and the PM ASCE std Etr equations. Calculated crop coefficients (as a ratio of measured crop water use and calculated potential evapotranspiration) based on alfalfa reference evapotranspiration with the 1982 Kimberly-Penman equation averaged 0.58 for the three years at Logan. Seasonal averages varied from 0.57 to 0.60. Seasonal crop coefficients (2002) were 0.57 for Logan, Spanish Fork, and Sunbrook, and 0.65 for Murray. Short-period crop coefficients also varied within a given season. Short-term crop coefficients derived from a time of wetting and drainage experiment averaged 0.55 at Logan, 0.56 at Murray, 0.60 at Spanish Fork, and 0.56 at Sunbrook

Markers of anti-malarial drug resistance in Plasmodium falciparum isolates from Swaziland: identification of pfmdr1-86F in natural parasite isolates

BACKGROUND: The development of Plasmodium falciparum resistance to chloroquine (CQ) has limited its use in many malaria endemic areas of the world. However, despite recent drug policy changes to adopt the more effective artemisinin-based combination (ACT) in Africa and in the Southern African region, in 2007 Swaziland still relied on CQ as first-line anti-malarial drug. METHODS: Parasite DNA was amplified from P. falciparum isolates from Swaziland collected in 1999 (thick smear blood slides) and 2007 (filter paper blood spots). Markers of CQ and sulphadoxine-pyrimethamine (SP) resistance were identified by probe-based qPCR and DNA sequencing. RESULTS: Retrospective microscopy, confirmed by PCR amplification, found that only six of 252 patients treated for uncomplicated malaria in 2007 carried detectable P. falciparum. The pfcrt haplotype 72C/73V/74I/75E/76T occurred at a prevalence of 70% (n = 64) in 1999 and 83% (n = 6) in 2007. Prevalence of the pfmdr1-86N allele was 24% in 1999 and 67% in 2007. A novel substitution of phenylalanine for asparagine at codon 86 of pfmdr1 (N86F) occurred in two of 51 isolates successfully amplified from 1999. The pfmdr1-1246Y allele was common in 1999, with a prevalence of 49%, but was absent among isolates collected in 2007. The 86N/184F/1246D pfmdr1 haplotype, associated with enhanced parasite survival in patients treated with artemether-lumefantrine, comprised 8% of 1999 isolates, and 67% among 2007 isolates. The pfdhfr triple-mutant 16C/51I/59R/108N/164I haplotype associated with pyrimethamine resistance was common in both 1999 (82%, n = 34) and 2007 (50%, n = 6), as was the wild-type 431I/436S/437A/540K/581A/613A haplotype of pfdhps (100% and 93% respectively in 1999 and 2007). The quintuple-mutant haplotype pfdhfr/pfdhps-CIRNI/ISGEAA, associated with high-level resistance to SP, was rare (9%) among 1999 isolates and absent among 2007 isolates. CONCLUSIONS: The prevalence of pfcrt and pfmdr1 alleles reported in this study is consistent with a parasite population under sustained CQ drug pressure. The low prevalence of dhps-437G and dhps-540E mutations (ISGEAA) and the rarity of quintuple-mutant haplotype pfdhfr/pfdhps-CIRNI/ISGEAA suggest that SP retains some efficacy in Swaziland. Anti-malarial policy changes in neighbouring countries may have had an impact on the prevalence of molecular markers of anti-malarial resistance in Swaziland, and it is hoped that this new information will add to understanding of the regional anti-malarial resistance map

ARCHIVED GIEMSA-STAINED THICK-SMEAR BLOOD SAMPLES AS A SOURCE OF DNA FOR PLASMODIUM FALCIPARUM DETECTION BY THE POLYMERASE CHAIN REACTION (PCR): AN IDEA FOR LOW TRANSMISSION SETTINGS

The absence of a reasonable number of cases of malaria in low transmission settings often presents problems for epidemiologic studies of antimalarial drug resistance. Whole blood from filter paper spots is normally used as a source of deoxyribonucleic acid (DNA). The number of samples available to derive statistical power is usually limited due to low transmission rates. This study suggests an alternative source of DNA from Giemsa-stained thick smears (GSTS) for epidemiological studies of Plasmodium falciparum drug resistance. A total of 73 archived GSTS and 6 whole blood filter paper samples were available for this analysis. DNA obtained from GSTS was successfully extracted, genotyped and sequenced for 64 (88%) samples for the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene, 51 (70%) samples for the Plasmodium falciparum multi-drug resistance 1 (pfmdr1) gene, 34 (47%) samples for the Plasmodium falciparum dihydrofolate reductase (pfdhfr) gene and 27 (37%) samples for the Plasmodium falciparum dihydropteroate synthase (pfdhps) gene. Whole blood from the 6 filter paper samples that were also run for comparison were all (100%) successfully genotyped and sequenced in a single attempt for all the four genes. The ease of the analysis of the filter paper DNA samples and the quality of the gel electrophoresis pictures suggests that filter paper DNA sources are much more sensitive than archived GSTS samples. Nonetheless, the results of this study suggest that safely stored and clearly labelled GSTS can provide a cheap and somewhat reliable alternative source of DNA for retrospective epidemiologic studies using the polymerase chain reaction (PCR) analyses where filter paper sources are either not available or insufficient. It is, therefore, strongly recommended that laboratories in malaria low transmission settings develop guidelines for safe storage of GSTS for future use in genotyping and other experiments. Protocols to refine extraction and PCR methods as well as the design of appropriate primer pairs may improve the sensitivity of current PCR methods to improve the results of GSTS

Kinetic, equilibrium and thermodynamic modelling of the sorption of metals from aqueous solution by a silica polyamine composite

Batch sorption studies were conducted to assess the potential of a phosphonated silica polyamine composite (BPAP) to remove metals (Co, Cu, Fe, Mg, Mn, Ni, U and Zn) from mine waters. The metal adsorption showed a good Langmuir isotherm fit. Ni and Mn fitted both the Freundlich and Langmuir isotherms. The activation energies (Ea) of Co, Mg and Ni ranged between 5 and 40 kJ∙moℓ-1, signifying physisorption while U showed a chemisorption type of adsorption (with Ea > 50 kJ∙moℓ-1). Cu and Fe on the other hand gave negative Ea values, indicating their preference to bind to low-energy sites. The pseudo-second-order kinetic model provided the best correlation of the experimental data, except for Mg and Ni for which the pseudo-first-order model and the Elovich model gave a better fit, respectively. Adsorption was almost constant over a wide pH regime and increased with time. Adsorption increased with concentration of the metals with the exception of Co, Fe and Ni which displayed about a 40% drop at a concentration of 200 mg∙ℓ-1. Desorption experimental data gave poor results except for U which showed 99.9% desorption.Keywords: silica polyamine composite, sorption, kinetics, isotherms, desorptio

'This is what is going to help me': Developing a co-designed and theoretically informed harm reduction intervention for mobile youth in South Africa and Uganda

Young migrants in sub-Saharan Africa are particularly vulnerable to HIV-acquisition. Despite this, they are consistently under-served by services, with low uptake and engagement. We adopted a community-based participatory research approach to conduct longitudinal qualitative research among 78 young migrants in South Africa and Uganda. Using repeat in-depth interviews and participatory workshops we sought to identify their specific support needs, and to collaboratively design an intervention appropriate for delivery in their local contexts. Applying a protection-risk conceptual framework, we developed a harm reduction intervention which aims to foster protective factors, and thereby nurture resilience, for youth ‘on the move’ within high-risk settings. Specifically, by establishing peer supporter networks, offering a ‘drop-in’ resource centre, and by identifying local adult champions to enable a supportive local environment. Creating this supportive edifice, through an accessible and cohesive peer support network underpinned by effective training, supervision and remuneration, was considered pivotal to nurture solidarity and potentially resilience. This practical example offers insights into how researchers may facilitate the co-design of acceptable, sustainable interventions

ACUTE PERICARDITIS ON EXAMPLE OF ILLUSTRATIVE CLINICAL CASE

Pericarditis is an important diagnosis to consider in a patient presenting with chest pain. This article describes the common features and management of pericarditis in the general practice setting on the example of clinical case. To the cardiologic department was admitted middle aged male. He complained of sharp retrosternal pain, and fever. The survey revealed distinctive features of pericarditis: pericardial friction rub on auscultation, diffuse PR segment depressions on ECG, pericardial effusion on echocardiography, but etiology was not elicit. Most cases are labeled as «idiopathic» because the traditional diagnostic approach often fails to identify the etiology. The presence of febrile fever and neutrophilic leukocytosis indicates that a bacterial etiology take place. Prompt antibacterial and anti-inflammatory treatment led to recovery of the patient. He was completely free of symptoms and had returned to his pre-morbid state

Integration of the Demographic Dividend into Government Plans: A Case of the Kwazulu-Natal Province of South Africa

The Population reference Bureau policy brief, (Gribble and Bremmer, 2012):1) described the demographic dividendas “…the accelerated economic growth that may result from a decline in a country’s mortality and fertility and thesubsequent change in the age structure of the population. With fewer births each year, a country’s young dependentpopulation grows smaller in relation to the working-age population. With fewer people to support, a country has awindow of opportunity for rapid economic growth if the right social and economic policies developed and investments made”. Several South Africa based studies have explored age structure and the prospects of a demographic dividend. These studies range from those that explore timing of the dividend to those that investigate readiness to harness the dividend. Three aspects of the demographic dividend are investigated by this research. Firstly, the paper will explorethe age structure of KwaZulu-Natal population to ascertain the timing of the age-structure (youth bulge) that is a pre-requisite for the dividend. Secondly, demographic, health and education characteristics that are knows to affect the achievement of the dividend will be examined. Lastly, the extent of integration of the demographic dividend into Integrated Development Plans (IDPs) in the province will be explored

Prolonged treatment of COVID-19 pneumonia with high-flow nasal oxygen: A story of oxygen and resilience

The COVID-19 pandemic has placed significant strain on the oxygen delivery infrastructure of health facilities in resource-constrained health systems. In this case report, we describe a patient with severe COVID-19 pneumonia who was managed with high-flow nasal oxygen for 40 days, with an eventual successful outcome. We discuss the oxygen delivery infrastructure needed to offer this intervention, as well as the psychosocial impact on those undergoing treatment

Deep learning of HIV field-based rapid tests

Although deep learning algorithms show increasing promise for disease diagnosis, their use with rapid diagnostic tests performed in the field has not been extensively tested. Here we use deep learning to classify images of rapid human immunodeficiency virus (HIV) tests acquired in rural South Africa. Using newly developed image capture protocols with the Samsung SM-P585 tablet, 60 fieldworkers routinely collected images of HIV lateral flow tests. From a library of 11,374 images, deep learning algorithms were trained to classify tests as positive or negative. A pilot field study of the algorithms deployed as a mobile application demonstrated high levels of sensitivity (97.8%) and specificity (100%) compared with traditional visual interpretation by humans-experienced nurses and newly trained community health worker staff-and reduced the number of false positives and false negatives. Our findings lay the foundations for a new paradigm of deep learning-enabled diagnostics in low- and middle-income countries, termed REASSURED diagnostics1, an acronym for real-time connectivity, ease of specimen collection, affordable, sensitive, specific, user-friendly, rapid, equipment-free and deliverable. Such diagnostics have the potential to provide a platform for workforce training, quality assurance, decision support and mobile connectivity to inform disease control strategies, strengthen healthcare system efficiency and improve patient outcomes and outbreak management in emerging infections

Environmental flows in support of sustainable intensification of agriculture in the Letaba River Basin, South Africa

This study evaluates the socioecological consequences of the potential trade-offs between maintaining environmental flows (e-flows) and providing water for sustainable subsistence agriculture and livelihoods to the vulnerable human communities living along the lower Great Letaba River in South Africa. Implementation of e-flows is now generally recognized as an essential part of water resources management as they are designed to ensure that sufficient water is retained in a river to protect river ecosystems and all the beneficiaries of services that arise from those ecosystems. Understanding the relationship between e-flows and the use of water for small-scale agriculture is important for the management of trade-offs. The Letaba River Basin and it's tributary, the Great/Groot Letaba, are located in the eastern part of the Limpopo province in South Africa. This is one of the most important river basins in the region supporting both large-scale commercial and small-scale farmers. The river sustains many vulnerable human communities who depend on the ecosystem services provided by the river. Yet, the water resources of the Letaba River are heavily overutilized due to expanding developments, including upstream dams with associated offtakes mostly for irrigation. The findings of the study indicate that irrigation water demand from subsistence agriculture in the Great Letaba Basin amounted to around 2 million cubic meters annually with median demand not exceeding 300,000 cubic meters per month. This means that irrigation water demand from smallholder agriculture only amounts to about one-tenth of the estimated e-flow requirement. However, small-scale farmers contend with an increasing crop water gap which limits irrigated agriculture, especially during the dry season. Given the need to sustainably maintain e-flows for ecological purposes, crop water gaps are only likely to increase and compromise the sustainability of irrigated agriculture. With active upstream supplementation of river flows from dams to maintain both environmental and livelihoods-oriented river flows, the crop water gap can be fully eliminated. This supplementation is not assured due to competing uses