Bank filtration: a sustainable water treatment technology for developing countries

As good quality water sources become more scare, water quality standards become more stringent and the cost of water treatment is increasing, there is need for a sustainable and robust water treatment technology. Bank filtration has been used for surface water treatment in Europe and USA for many years. However, this technology has not been utilised fully in developing countries. Bank filtration is a natural process of water treatment which is simple, avoids the use of chemicals and when properly designed and operated produces water of acceptable quality and reduces the cost of water treatment. It utilises the physical, chemical and biological removal processes in the soil and aquifer for purification of surface water during its passage to production wells. Based on the results of two feasibility studies conducted in Malawi and Kenya, this paper elaborates on the potentials and constraints of promoting bank filtration technology for water treatment in developing countries

Sustainability analysis of water supply systems in Cochabamba, Bolivia

After the decentralisation, water supply systems in several municipalities of Cochabamba department, Bolivia are being managed by different local institutions. The main aim of this study was to make a comparative evaluation of the sustainability of three water supply systems in Cochabamba, Quillacollo and Tiquipaya municipalities of Cochabamba. Based on the results of extensive field data collection and sustainability scoring system developed, technical, financial, social, institutional, and environmental aspects of these three water supply systems were analysed. Sustainability analysis showed that SEMAPA Cochabamba has the highest score in all sustainability aspects followed by COAPAT Tiquipaya and EMAPAQUI Quillacolo. Furthermore, the technical aspect is the weakest in all the three water supply systems. Lessons learnt from this study could be used to improve the sustainability of water supply systems in these municipalities and would be helpful to analyse water supply situations in other municipalities in Bolivia

Water supply systems in selected urban poor areas of Addis Ababa, Ethiopia

Water supply systems in three urban poor areas of Addis Ababa namely Teklehaimanot, Merkato and Biheretsige were evaluated based on a field survey of 105 randomly selected households and interviews with other major stakeholders. Private taps, yard taps, public taps, water kiosks and water vendors are the primary sources of water in these areas. The average water consumption of more than 75% of the sampled households was less than 20 litres per person per day. Most of the households pay a relatively high price for drinking water with the average cost of ETB 6.2/m3 (US$ 0.74/m3). Although many households are willing to have private or yard taps, they can not afford the one time connection fee payment of about ETB 412. An innovative financing and cost recovery mechanism is required, specifically for the initial connection fees, in order to increase the coverage of safe water supply at an affordable price in these areas to meet the Millennium Development Goals

Air-conditioning guidelines for healthcare facilities during the covid pandemic

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The disease spreads primarily through respiratory droplets, physical contact and contact with surfaces as well as fomites. Isolation of patients in hospitals and quarantine of contacts in separate facilities are the mainstay of outbreak containment. This pandemic has brought forward various challenges to the hospital administrators, one of the most important being air-conditioning of hospitals in the time of this pandemic

Water loss management: a case study of Ho Chi Minh City, Vietnam

Ho Chi Minh City in Vietnam has very high non-revenue water (NRW) of 91 million m3/year (about 40% of total production) while there is shortage in water supply in the city. Analysis of the causes and components of such high water losses is necessary to develop programmes for its reduction. This paper reviews the existing water supply and losses in the distribution systems, their components based on the field data and analyses it by calculating different water loss indicators. It was found that NRW is composed of 83% real losses and 17% apparent losses. Invisible leaks in the service pipes (due to ageing) is the major cause of water losses. There are no proper water auditing, distribution system maps or databases to quantify the water losses components accurately. The study showed that there is high potential for water saving in Ho Chi Minh city by implementing several short-term and long-term measures

Evaluation of handpump water supply in selected rural and semi-urban areas of Zambia

Handpumps are widely used for water supply in rural and semi-urban areas of Zambia. This could be an attractive technology to provide safe water supply to additional number of unserved people. However, as the handpumps used in Zambia are imported from outside and financed mainly by donors, the sustainability of this water supply system is questionable. This study reviewed different factors affecting sustainability of handpump water supply in Zambia through a field study conducted in selected rural and semi-urban areas of Zambia. The study revealed that despite the low level of support from government and donors during the O&M phase, most of the handpumps are in relatively good condition. Access to spare parts and financing of O&M costs are the main problems in many rural areas of Zambia. Local manufacture of handpumps, continued support from the government agencies and donors in O&M phase and water quality testing is recommended for long-term sustainability of handpump water supply systems in Zambia

Investigating water meter performance in developing countries: A case study of Kampala, Uganda

This paper examines the performance of 3 meter models, on the basis of failure records for a developing world water utility in Kampala city, Uganda.High levels of water losses in distribution systems are the main challenge that water utilities in developing countries currently face. The water meter is an essential tool for both the utility and the customers to measure and monitor consumption. When metering is inefficient and coupled with low tariffs, the financial sustainability of utilities is at stake. Apparent water losses caused by metering inefficiencies can be reduced by assessing meters’ performance and identifying the main causes of inefficiency. This paper examines the performance of 3 meter models, on the basis of failure records for a developing world water utility in Kampala city, Uganda. The influence of sub-metering on meter accuracy is also examined. The results indicate a high meter failure rate (6.6%/year) in Kampala. Over 75% of failures were observed in the volumetric (oscillating-piston) meter types with the main cause of meter failure being particulates in water. The study also indicates an average reduction in revenue water registration of 18% due to sub-metering. The reduction was not because of water use efficiency but due to the combined effect of the metering errors of the sub-meters. This clearly implies that when properties are sub-metered, customers should be charged proportionately based on master meter readings, for accurate water accountability. The findings of this study will be useful for both utility managers and meter manufacturers who work in the water industry, especially in developing countries, to make appropriate metering and sub-metering decisions

The Malignant Pleural Effusion as a Model to Investigate Intratumoral Heterogeneity in Lung Cancer

Malignant Pleural Effusions (MPE) may be useful as a model to study hierarchical progression of cancer and/or intratumoral heterogeneity. To strengthen the rationale for developing the MPE-model for these purposes, we set out to find evidence for the presence of cancer stem cells (CSC) in MPE and demonstrate an ability to sustain intratumoral heterogeneity in MPE-primary cultures. Our studies show that candidate lung CSC-expression signatures (PTEN, OCT4, hTERT, Bmi1, EZH2 and SUZ12) are evident in cell pellets isolated from MPE, and MPE-cytopathology also labels candidate-CSC (CD44, cMET, MDR-1, ALDH) subpopulations. Moreover, in primary cultures that use MPE as the source of both tumor cells and the tumor microenvironment (TME), candidate CSC are maintained over time. This allows us to live-sort candidate CSC-fractions from the MPE-tumor mix on the basis of surface markers (CD44, c-MET, uPAR, MDR-1) or differences in xenobiotic metabolism (ALDH). Thus, MPE-primary cultures provide an avenue to extract candidate CSC populations from individual (isogenic) MPE-tumors. This will allow us to test whether these cells can be discriminated in functional bioassays. Tumor heterogeneity in MPE-primary cultures is evidenced by variable immunolabeling, differences in colony-morphology, and differences in proliferation rates of cell subpopulations. Collectively, these data justify the ongoing development of the MPE-model for the investigation of intratumoral heterogeneity, tumor-TME interactions, and phenotypic validation of candidate lung CSC, in addition to providing direction for the pre-clinical development of rational therapeutics

Polymorphisms of TNF-enhancer and gene for FcγRIIa correlate with the severity of falciparum malaria in the ethnically diverse Indian population

<p>Abstract</p> <p>Background</p> <p>Susceptibility/resistance to <it>Plasmodium falciparum </it>malaria has been correlated with polymorphisms in more than 30 human genes with most association analyses having been carried out on patients from Africa and south-east Asia. The aim of this study was to examine the possible contribution of genetic variants in the <it>TNF </it>and <it>FCGR2A </it>genes in determining severity/resistance to <it>P. falciparum </it>malaria in Indian subjects.</p> <p>Methods</p> <p>Allelic frequency distribution in populations across India was first determined by typing genetic variants of the <it>TNF </it>enhancer and the <it>FCGR2A </it>G/A SNP in 1871 individuals from 55 populations. Genotyping was carried out by DNA sequencing, single base extension (SNaPshot), and DNA mass array (Sequenom). Plasma TNF was determined by ELISA. Comparison of datasets was carried out by Kruskal-Wallis and Mann-Whitney tests. Haplotypes and LD plots were generated by PHASE and Haploview, respectively. Odds ratio (OR) for risk assessment was calculated using EpiInfo™ version 3.4.</p> <p>Results</p> <p>A novel single nucleotide polymorphism (SNP) at position -76 was identified in the <it>TNF </it>enhancer along with other reported variants. Five <it>TNF </it>enhancer SNPs and the <it>FCGR2A </it>R131H (G/A) SNP were analyzed for association with severity of <it>P. falciparum </it>malaria in a malaria-endemic and a non-endemic region of India in a case-control study with ethnically-matched controls enrolled from both regions. <it>TNF </it>-1031C and -863A alleles as well as homozygotes for the TNF enhancer haplotype CACGG (-1031T>C, -863C>A, -857C>T, -308G>A, -238G>A) correlated with enhanced plasma TNF levels in both patients and controls. Significantly higher TNF levels were observed in patients with severe malaria. Minor alleles of -1031 and -863 SNPs were associated with increased susceptibility to severe malaria. The high-affinity IgG2 binding FcγRIIa AA (131H) genotype was significantly associated with protection from disease manifestation, with stronger association observed in the malaria non-endemic region. These results represent the first genetic analysis of the two immune regulatory molecules in the context of <it>P. falciparum </it>severity/resistance in the Indian population.</p> <p>Conclusion</p> <p>Association of specific <it>TNF </it>and <it>FCGR2A </it>SNPs with cytokine levels and disease severity/resistance was indicated in patients from areas with differential disease endemicity. The data emphasizes the need for addressing the contribution of human genetic factors in malaria in the context of disease epidemiology and population genetic substructure within India.</p

Variations in host genes encoding adhesion molecules and susceptibility to falciparum malaria in India

<p>Abstract</p> <p>Background</p> <p>Host adhesion molecules play a significant role in the pathogenesis of <it>Plasmodium falciparum </it>malaria and changes in their structure or levels in individuals can influence the outcome of infection. The aim of this study was to investigate the association of SNPs of three adhesion molecule genes, <it>ICAM1</it>, <it>PECAM1 </it>and <it>CD36</it>, with severity of falciparum malaria in a malaria-endemic and a non-endemic region of India.</p> <p>Methods</p> <p>The frequency distribution of seven selected SNPs of <it>ICAM1</it>, <it>PECAM1 </it>and <it>CD36 </it>was determined in 552 individuals drawn from 24 populations across India. SNP-disease association was analysed in a case-control study format. Genotyping of the population panel was performed by Sequenom mass spectroscopy and patient/control samples were genotyped by SNaPshot method. Haplotypes and linkage disequilibrium (LD) plots were generated using PHASE and Haploview, respectively. Odds-ratio (OR) for risk assessment was estimated using EpiInfo™ version 3.4.</p> <p>Results</p> <p>Association of the ICAM1 rs5498 (exon 6) G allele and the CD36 exon 1a A allele with increased risk of severe malaria was observed (severe versus control, OR = 1.91 and 2.66, P = 0.02 and 0.0012, respectively). The CD36 rs1334512 (-53) T allele as well as the TT genotype associated with protection from severe disease (severe versus control, TT versus GG, OR = 0.37, P = 0.004). Interestingly, a SNP of the <it>PECAM1 </it>gene (rs668, exon 3, C/G) with low minor allele frequency in populations of the endemic region compared to the non-endemic region exhibited differential association with disease in these regions; the G allele was a risk factor for malaria in the endemic region, but exhibited significant association with protection from disease in the non-endemic region.</p> <p>Conclusion</p> <p>The data highlights the significance of variations in the <it>ICAM1</it>, <it>PECAM1 </it>and <it>CD36 </it>genes in the manifestation of falciparum malaria in India. The <it>PECAM1 </it>exon 3 SNP exhibits altered association with disease in the endemic and non-endemic region.</p