Water Supply Interruptions Are Associated with More Frequent Stressful Behaviors and Emotions but Mitigated by Predictability: A Multisite Study.

Water supply interruptions contribute to household water insecurity. Unpredictable interruptions may particularly exacerbate water insecurity, as uncertainty limits households' ability to optimize water collection and storage or to modify other coping behaviors. This study used regression models of survey data from 2873 households across 10 sites in 9 middle-income countries to assess whether water supply interruptions and the predictability of interruptions were related to composite indicators of stressful behaviors and emotional distress. More frequent water service interruptions were associated with more frequent emotional distress (ß = 0.49, SE = 0.05, P < 0.001) and stressful behaviors (ß = 0.39, SE = 0.06, P < 0.001). Among households that experienced interruptions, predictability mitigated these respective relationships by approximately 25 and 50%. Where the provision of continuous water supplies is challenged by climate change, population growth, and poor management, water service providers may be able to mitigate some psychosocial consequences of intermittency through scheduled intermittency and communication about water supply interruptions. Service providers unable to supply continuous water should optimize intermittent water delivery to reduce negative impacts on users, and global monitoring regimes should account for intermittency and predictability in post-2030 water service metrics to better reflect household water insecurity experiences.

Expression and in vitro anticancer activity of Lp16-PSP, a member of the YjgF/YER057c/UK114 protein family from the mushroom Lentinula edodes C91-3.

Latcripin-16 (Lp16-PSP) is a gene that was extracted as a result of de novo characterization of the Lentinula edodes strain C91-3 transcriptome. The aim of the present study was to clone, express, and investigate the selective in vitro anticancer potential of Lp16-PSP in human cell lines. Lp16-PSP was analyzed using bioinformatics tools, cloned in a prokaryotic expression vector pET32a (+) and transformed into E. coli Rosetta gami. It was expressed and solubilized under optimized conditions. The differential scanning fluorometry (DSF)-guided refolding method was used with modifications to identify the proper refolding conditions for the Lp16-PSP protein. To determine the selective anticancer potential of Lp16-PSP, a panel of human cancerous and non-cancerous cell lines was used. Lp16-PSP protein was identified as endoribonuclease L-PSP protein and a member of the highly conserved YjgF/YER057c/UK114 protein superfamily. Lp16-PSP was expressed under optimized conditions (37 °C for 4 h following induction with 0.5 mM isopropyl ß-D-1-thiogalactopyranoside). Solubilization was achieved with mild solubilization buffer containing 2 M urea using the freeze-thaw method. The DSF guided refolding method identified the proper refolding conditions (50 mM Tris-HCl, 100 mM NaCl, 1 mM EDTA, 400 mM Arginine, 0.2 mM GSH and 2 mM GSSG; pH 8.0) for Lp16-PSP, with a melting transition of ~ 58 °C. A final yield of ~ 16 mg of purified Lp16-PSP from 1 L of culture was obtained following dialysis and concentration by PEG 20,000. A Cell Counting Kit-8 assay revealed the selective cytotoxic effect of Lp16-PSP. The HL-60 cell line was demonstrated to be most sensitive to Lp16-PSP, with an IC50 value of 74.4 ± 1.07 µg/ml. The results of the present study suggest that Lp16-PSP may serve as a potential anticancer agent; however, further investigation is required to characterize this anticancer effect and to elucidate the molecular mechanism underlying the action of Lp16-PSP.

Comparative study to develop a single method for retrieving wide class of recombinant proteins from classical inclusion bodies.

The formation of inclusion bodies (IBs) is considered as an Achilles heel of heterologous protein expression in bacterial hosts. Wide array of techniques has been developed to recover biochemically challenging proteins from IBs. However, acquiring the active state even from the same protein family was found to be an independent of single established method. Here, we present a new strategy for the recovery of wide sub-classes of recombinant protein from harsh IBs. We found that numerous methods and their combinations for reducing IB formation and producing soluble proteins were not effective, if the inclusion bodies were harsh in nature. On the other hand, different practices with mild solubilization buffers were able to solubilize IBs completely, yet the recovery of active protein requires large screening of refolding buffers. With the integration of previously reported mild solubilization techniques, we proposed an improved method, which comprised low sarkosyl concentration, ranging from 0.05 to 0.1% coupled with slow freezing (- 1 °C/min) and fast thaw (room temperature), resulting in greater solubility and the integrity of solubilized protein. Dilution method was employed with single buffer to restore activity for every sub-class of recombinant protein. Results showed that the recovered protein's activity was significantly higher compared with traditional solubilization/refolding approach. Solubilization of IBs by the described method was proved milder in nature, which restored native-like conformation of proteins within IBs.

Polysaccharides Extracted from Rhizoma Pleionis Have Antitumor Properties In Vitro and in an H22 Mouse Hepatoma Ascites Model In Vivo.

Malignant ascites is a highly severe and intractable complication of advanced or recurrent malignant tumors that is often immunotherapy-resistant. Rhizoma Pleionis is widely used in traditional medicine as an antimicrobial and anticancer agent, but its effectiveness in treating malignant ascites is unclear. In the current study, we investigated the effect of polysaccharides isolated from Rhizoma Pleionis (PRP) on murine hepatocarcinoma H22 cells in an ascites model. We have found that the main components of PRP, that presented a relative molecular weight of 383.57 kDa, were mannose and glucose. We also found that PRP reduced the occurrence of abdominal ascites and increased survival in our mouse model. An immune response in the ascites tumor model was observed by performing a lymphocytes proliferation experiment and an E-rosette test. The ratios of CD8+ cytotoxic T cells and NK cells in the spleen were examined by flow cytometry, and the mRNA expression of Foxp3+in CD4⁺CD25⁺ (T regulatory Tregs) was measured by RT-PCR (reverse transcription-polymerase chain reaction). The levels of the cytokines TNF-α (tumor necrosis factor), VEGF (vascular endothelial growth factor), IL-2 (interleukin), and IFN-γ (interferon) in the serum and ascites supernatants were measured by ELISA. The expression of Foxp3 and Stat3 in peritoneal cells in the mouse model was measured by immunocytochemistry. The results indicated that PRP increased H22 tumor cell apoptosis in vivo by activating and enhancing the immune response. Furthermore, the effects of PRP on the proliferation of H22 cells were assessed by the CCK8 assay, Hoechest 33258, and TUNEL staining in vitro. We found that PRP suppressed the proliferation of H22 tumor cells but had no effect on BRL (Big rat liver) -3A rat hepatoma normal cells in vitro. Next, we investigated the underlying immunological mechanism by which PRP inhibits malignant ascites. PRP induced tumor cell apoptosis by inhibiting the Jak1⁻Stat3 pathway and by activating Caspase-3 and Caspase-8 to increase the Bax/Bcl-2 ratio. Collectively, our results indicate that PRP exhibits significant antitumor properties in H22 cells in vivo and in vitro, indicating that PRP may be used as a new therapeutic drug for cancer treatment.

LP1 from Lentinula edodes C91-3 Induces Autophagy, Apoptosis and Reduces Metastasis in Human Gastric Cancer Cell Line SGC-7901.

Present study aimed to elucidate the anticancer effect and the possible molecular mechanism underlying the action of Latcripin 1 (LP1), from the mushroom Lentinula edodes strain C91-3 against gastric cancer cell lines SGC-7901 and BGC-823. Cell viability was measured by Cell Counting Kit-8 (CCK-8); morphological changes were observed by phase contrast microscope; autophagy was determined by transmission electron microscope and fluorescence microscope. Apoptosis and cell cycle were assessed by flow cytometer; wound-healing, transwell migration and invasion assays were performed to investigate the effect of LP1 on gastric cancer cell's migration and invasion. Herein, we found that LP1 resulted in the induction of autophagy by the formation of autophagosomes and conversion of light chain 3 (LC3I into LC3II. LP1 up-regulated the expression level of autophagy-related gene (Atg7, Atg5, Atg12, Atg14) and Beclin1; increased and decreased the expression level of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2) proteins respectively, along with the activation of Caspase-3. At lower-doses, LP1 have shown to arrest cells in the S phase of the cell cycle and decreased the expression level of matrix metalloproteinase MMP-2 and MMP-9. In addition, it has also been shown to regulate the phosphorylation of one of the most hampered gastric cancer pathway, that is, protein kinase B/mammalian target of rapamycin (Akt/mTOR) channel and resulted in cell death. These findings suggested LP1 as a potential natural anti-cancer agent, for exploring the gastric cancer therapies and as a contender for further in vitro and in vivo investigations.

Antitumour activity of the novel flavonoid Oncamex in preclinical breast cancer models.

BACKGROUND: The natural polyphenol myricetin induces cell cycle arrest and apoptosis in preclinical cancer models. We hypothesised that myricetin-derived flavonoids with enhanced redox properties, improved cell uptake and mitochondrial targeting might have increased potential as antitumour agents. METHODS: We studied the effect of a second-generation flavonoid analogue Oncamex in a panel of seven breast cancer cell lines, applying western blotting, gene expression analysis, fluorescence microscopy and immunohistochemistry of xenograft tissue to investigate its mechanism of action. RESULTS: Proliferation assays showed that Oncamex treatment for 8 h reduced cell viability and induced cytotoxicity and apoptosis, concomitant with increased caspase activation. Microarray analysis showed that Oncamex was associated with changes in the expression of genes controlling cell cycle and apoptosis. Fluorescence microscopy showed the compound's mitochondrial targeting and reactive oxygen species-modulating properties, inducing superoxide production at concentrations associated with antiproliferative effects. A preliminary in vivo study in mice implanted with the MDA-MB-231 breast cancer xenograft showed that Oncamex inhibited tumour growth, reducing tissue viability and Ki-67 proliferation, with no signs of untoward effects on the animals. CONCLUSIONS: Oncamex is a novel flavonoid capable of specific mitochondrial delivery and redox modulation. It has shown antitumour activity in preclinical models of breast cancer, supporting the potential of this prototypic candidate for its continued development as an anticancer agent.

Series of quinone-containing nanosensors for biologically relevant redox potential determination by surface-enhanced Raman spectroscopy.

Redox potential is of key importance in the control and regulation of cellular function and lifecycle, and previous approaches to measuring the biological redox potential noninvasively in real time are limited to areas of hypoxia or normoxia. In this paper, we extend our previous work on nanoparticle-based intracellular nanosensors to cover a much wider redox potential range of -470 to +130 mV vs NHE, which includes the redox potential range occupied by cells in a state of oxidative stress. The nanosensors are rationally designed to target different areas of this redox potential range and are monitored by surface-enhanced Raman spectroscopy, which will permit noninvasive real-time imaging of cells undergoing oxidative stress.

The Impact of Rapid Handpump Repairs on Diarrhea Morbidity in Children: Cross-Sectional Study in Kwale County, Kenya.

BACKGROUND: Handpumps are used by millions of people as their main source of water. Although handpumps represent only a basic form of water provision, there have been continuous efforts to improve the performance of these systems as they are likely to remain in use for many years to come. The introduction of a professional maintenance service in southern Kenya has shown an order of magnitude improvement in operational performance over community-based management, with 90% of handpump faults repaired within 3 days of being reported. One driver behind these efforts is the assumption that a more reliable water supply will lead to a reduction in water-related disease. However, it is not clear if operational improvements lead to health gains. Despite limited empirical evidence, some modeling studies suggest that even short periods of drinking contaminated water can lead to disproportionate negative health impacts. OBJECTIVE: The aim of this study was to assess whether the improvements in operational performance from the rapid professional maintenance of rural handpumps lead to improved household health outcomes. METHODS: From a sample of households using handpumps as their primary water source in Kwale County, Kenya, we measured the 2-week prevalence of World Health Organization-defined diarrhea in children, reported by the adult respondent for each household. We compared the rates before and after a period during which the households' handpumps were being professionally maintained. We then conducted a cross-sectional analysis, fitting logistic regression models with reported diarrhea as the dependent variable and speed of repair as the independent exposure of interest, adjusting for household socioeconomic characteristics; dwelling construction; and Water, Sanitation, and Hygiene (WASH)-related factors. We fitted an additional model to examine select interactions between covariates. RESULTS: Reported diarrhea in children was lower in households whose pumps had been repaired within 24 hours (adjusted odds ratio 0.35, 95% CI 0.24-0.51). This effect was robust to the inclusion of multiple categories of covariates. No reduction was seen in households whose pump repairs took more than 24 hours. Analysis of interaction terms showed that certain interventions associated with improved WASH outcomes were only associated with reductions in diarrhea in conjunction with socioeconomic improvements. CONCLUSIONS: Only pump repairs consistently made within 24 hours of failure led to a reduction in diarrhea in the children of families using handpumps. While the efficacy of reduction in diarrhea is substantial, the operational challenges of guaranteeing same-day repairs limits the effectiveness of even best-in-class pump maintenance. Maintenance regimes that cannot bring handpump downtimes close to zero will struggle to generate health benefits. Other factors that reduce diarrhea prevalence have limited effect in isolation, suggesting that WASH interventions will be more effective when undertaken as part of more holistic poverty-reduction efforts.

Reaction hijacking inhibition of Plasmodium falciparum asparagine tRNA synthetase.

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism.

AAAA-DDDD quadruple hydrogen-bond arrays featuring NH···N and CH···N hydrogen bonds.

The X-ray crystal structure of a previously reported extremely strong quadruple NH···N AAAA-DDDD hydrogen-bond array [5·4] (K(a) = 1.5 × 10(6) M(-1) in CH3CN; K(a) > 3 × 10(12) M(-1) in CH2Cl2) features four short linear hydrogen bonds. Changing the two benzimidazole groups of the DDDD unit to triazole groups replaces two of the NH···N hydrogen bonds with CH···N interactions (complex [5·6]), but only reduces the association constant in CH3CN by 2 orders of magnitude (K(a) = 2.6 × 10(4) M(-1) in CH3CN; K(a) > 1 × 10(7) M(-1) in CH2Cl2). Related complexes without the triazole groups range in K(a) from 18 to 270 M(-1) in CH3CN, suggesting that the CH···N interactions can be considered part of a strong AAAA-DDDD quadruple hydrogen-bonding array. The NH···N/CH···N AAAA-DDDD motif can be repeatedly switched "on" and "off" in CDCl3 through successive additions of acid and base.

MAD Water: Integrating Modular, Adaptive, and Decentralized Approaches for Water Security in the Climate Change Era.

Centralized water infrastructure has, over the last century, brought safe and reliable drinking water to much of the world. But climate change, combined with aging and underfunding, is increasingly testing the limits of-and reversing gains made by-these large-scale water systems. To address these growing strains and gaps, we must assess and advance alternatives to centralized water provision and sanitation. The water literature is rife with examples of systems that are neither centralized nor networked, but still meet water needs of local communities in important ways, including: informal and hybrid water systems, decentralized water provision, community-based water management, small drinking water systems, point-of-use treatment, small-scale water vendors, and packaged water. Our work builds on these literatures by proposing a convergence approach that can integrate and explore the benefits and challenges of modular, adaptive, and decentralized ("MAD") water provision and sanitation, often foregrounding important advances in engineering technology. We further provide frameworks to evaluate justice, economic feasibility, governance, human health, and environmental sustainability as key parameters of MAD water system performance.

Reaction hijacking inhibition of Plasmodium falciparum asparagine tRNA synthetase.

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure activity relationship and the selectivity mechanism.

Duloxetine ameliorates valproic acid-induced hyperactivity, anxiety-like behavior, and social interaction deficits in zebrafish.

Syndromic autism spectrum disorders (ASDs) are characterized by impaired social communication and repetitive/stereotyped behaviors. Currently available therapeutic agents against ASD have limited efficacy. Thus, searching for novel and effective drugs ameliorating core symptoms, in particular social deficits, is of utmost importance. Duloxetine (DLX), an antidepressant that has been identified as an agonist mimetic for the cell adhesion molecule L1, exhibits beneficial functions in vitro and in vivo. Therefore, in this study, we focused on the rapid and persistent neuroprotective function of DLX following valproic acid (VPA)-triggered hyperactivity, anxiety-like behavior and social deficits in zebrafish. Embryonic exposure to VPA reduced survival in a dose- and time-dependent manner, delayed hatching, and also resulted in a significant number of malformed larvae. After initial dose-response experiments in zebrafish larvae, 10 µM VPA exposure between 0.33 and 4.5 days post fertilization (dpf) was identified as an effective concentration that led to an early and persistent ASD-like phenotype in zebrafish. ASD-like elevated acetylcholine esterase (AChE) activity and reduced Akt-mTOR signaling was observed in zebrafish whole brain. Acute administration of DLX (4.5-6 dpf) reduced the VPA-induced ASD-like phenotype in zebrafish larvae. Additionally, such early-life acute DLX treatment had long-term effects in ameliorating social impairments, hyperactivity, and anxiety-like behaviors through adulthood. This was accompanied by reduced AChE activity and by normalized Akt-mTOR signaling. Overall, DLX treatment showed a long-term therapeutic effect on autistic-like behaviors, and alteration of AChE activity and Akt-mTOR signaling were identified as crucial in the VPA-induced ASD zebrafish model.

Chondroitin 6-sulfate-binding peptides improve recovery in spinal cord-injured mice.

The role of glycosaminoglycan sulfation patterns, particularly in regard to scar formation and inhibition of neuritogenesis, has been mainly studied in cell culture with a focus on chondroitin 4-sulfate. In this study, we investigated chondroitin 6-sulfate (C6S) and found that it also inhibits neurite outgrowth of mouse cerebellar granule neurons in vitro. To examine whether the inhibitory activity of C6S could be neutralized, seven previously characterized high-affinity C6S-binding peptides were tested, among which three peptides neutralized the inhibitory functions of C6S. We further investigated these peptides in a mouse model of spinal cord injury, since upregulation of C6S expression in the glial scar following injury has been associated with reduced axonal regrowth and functional recovery. We here subjected mice to severe compression injury at thoracic levels T7-T9, immediately followed by inserting gelfoam patches soaked in C6S-binding peptides or in a control peptide. Application of C6S-binding peptides led to functional recovery after injury and prevented fibrotic glial scar formation, as seen by decreased activation of astrocytes and microglia/macrophages. Decreased expression of several lecticans and deposition of fibronectin at the site of injury were also observed. Application of C6S-binding peptides led to axonal regrowth and inhibited the C6S-mediated activation of RhoA/ROCK and decrease of PI3K-Akt-mTOR signaling pathways. Taken together, these results indicate that treatment with C6S-binding peptides improves functional recovery in a mouse model of spinal cord injury.

Reducing drought emergencies in the Horn of Africa.

Drought-driven humanitarian emergencies are becoming more frequent in the Horn of Africa where millions of people in this arid region face chronic water and food insecurity. Evidence from the region shows increasing reliance on groundwater supplies, infrastructure and institutional systems in response to decreasing rainfall. Drought emergencies can be mitigated by investing in resilience efforts that make safe water reliably available at strategic groundwater abstraction locations during cycles of water stress. A combination of early warning data, policy reform, asset management and improved rural water supplies and maintenance may enable rapid, responsive, and accountable water governance that is more cost effective than emergency relief and better positioned to absorb and adapt to shocks.

Adhesion Molecule L1 Agonist Mimetics Protect Against the Pesticide Paraquat-Induced Locomotor Deficits and Biochemical Alterations in Zebrafish.

Besides several endogenous elements, exogenous factors, including exposure to pesticides, have been recognized as putative factors contributing to the onset and development of neurodegenerative diseases, including Parkinson's disease (PD). Considering the availability, success rate, and limitations associated with the current arsenals to fight PD, there is an unmet need for novel therapeutic interventions. Therefore, based on the previously reported beneficial functions of the L1 cell adhesion molecule, we hypothesized that L1 mimetic compounds may serve to neutralize neurotoxicity triggered by the pesticide paraquat (PQ). In this study, we attempt to use PQ for inducing PD-like pathology and the L1 mimetic compounds phenelzine sulfate (PS) and tacrine (TC) as potential candidates for the amelioration of PD symptoms using zebrafish as a model system. Administration of PQ together with the L1 mimetic compounds PS or TC (250 nM) improved survival of zebrafish larvae, protected them from locomotor deficits, and increased their sensorimotor reflexes. Moreover, application of PQ together with PS (500 nM) or TC (1000 nM) in adult zebrafish counteracted PQ-induced toxicity, maintaining normal locomotor functions and spatial memory in an open field and T-maze task, respectively. Both L1 mimetic compounds prevented reduction in tyrosine hydroxylase and dopamine levels, reduced reactive oxygen species (ROS) generation, protected against impairment of mitochondrial viability, improved the antioxidant enzyme system, and prevented a decrease in ATP levels. Altogether, our findings highlight the beneficial functions of the agonistic L1 mimetics PS and TC by improving several vital cell functions against PQ-triggered neurotoxicity.

Rainfall and groundwater use in rural Kenya.

This study examines the relationship between rainfall and groundwater use in rural Kenya, using automatically-transmitted hourly data from handpumps (n = 266), daily rainfall records (n = 19), and household survey data (n = 2508). We demonstrate a 34% reduction in groundwater use during the wet season compared to the dry season, suggesting a large shift from improved to unimproved sources in the wet season. By cross-correlating handpump and rainfall time series, we also reveal substantial short-term changes in groundwater pumping observed immediately following heavy rainfall. Further investigation and modelling of this response reveals a 68% reduction in pump use on the day immediately following heavy rain. We then investigate reasons for this behavioural response to rainfall, using survey data to examine the characteristics, concerns and behaviours of households in the area where the reduction in pump use was most marked. In this area rainwater harvesting was widespread and only 6% of households reported handpumps as their sole source of drinking water in the wet season, compared to 86% in the dry season. These findings shed light on the impact increasing rainfall variability may have on the Sustainable Development Goal of "universal and equitable access to safe and affordable drinking water for all". Specifically, we suggest a flaw in the water policy assumption that the provision of improved sources of drinking water-in this case community handpumps-translates to consistent use and the associated health benefits. We note that failure to understand and account for actual water use behaviour may results in adverse public health outcomes and maladapted WASH policy and interventions.

Tryptophan-like fluorescence as a measure of microbial contamination risk in groundwater.

Microbial water quality is frequently assessed with a risk indicator approach that relies on Escherichia coli. Relying exclusively on E. coli is limiting, particularly in low-resource settings, and we argue that risk assessments could be improved by a complementary parameter, tryptophan-like fluorescence (TLF). Over two campaigns (June 2016 and March 2017) we sampled 37 water points in rural Kwale County, Kenya for TLF, E. coli and thermotolerant coliforms (total n = 1082). Using three World Health Organization defined classes (very high, high, and low/intermediate), risk indicated by TLF was not significantly different from risk indicated by E. coli (p = 0.85). However, the TLF and E. coli risk classifications did show disagreement, with TLF indicating higher risk for 14% of samples and lower risk for 13% of samples. Comparisons of duplicate/replicate results demonstrated that precision is higher for TLF (average relative percent difference of duplicates = 14%) compared to culture-based methods (average RPD of duplicates ≥ 26%). Additionally, TLF sampling is more practical because it requires less time and resources. Precision and practicality make TLF well-suited to high-frequency sampling in low resource contexts. Interpretation and interference challenges are minimised when TLF is measured in groundwaters, which typically have low dissolved organic carbon, relatively consistent temperature, negligible turbidity and pH between 5 and 8. TLF cannot be used as a proxy for E. coli on an individual sample basis, but it can add value to groundwater risk assessments by improving prioritization of sampling and by increasing understanding of spatiotemporal variability.

How does water-reliant industry affect groundwater systems in coastal Kenya?

The industrialization process taking place in Africa has led to an overall increase in groundwater abstraction in most countries in the continent. However, the lack of hydrogeological data, as in many developing countries, makes it difficult to properly manage groundwater systems. This study presents a real case study in which a combination of different hydrogeological tools together with different sources of information allow the assessment of how increased competition for water may be affecting groundwater systems by analysing the sustainability of new abstraction regimes under different real climatic condition (before, during and after La Niña 2016). The area where this approach has been applied is Kwale County (in Coastal Kenya) in a hydrogeological context representative of an important part of the east coast of the continent, where new mining and agriculture activities co-exist with tourism and local communities. The results show that the lack of aquifer systems data can be overcome, at least partly, by integrating different sources of information. Most of the time, water-reliant users collect specific hydrogeological information that can contribute to defining the overall hydrogeological system, since their own main purpose is to exploit the aquifer with the maximum productivity. Therefore, local community water usage, together with different stakeholder's knowledge and good corporate water management act as a catalyst for providing critical data, and allows the generation of credible models for future groundwater management and resource allocation. Furthermore, complementary but simple information sources such as in situ interviews, Google Earth, Trip Advisor and easy-to use analytical methods that can be applied in the African context as in many developing countries, and enables groundwater abstraction to be estimated and the sustainability of the aquifer system to be defined, allowing potential future risks to be assessed.

Risk factors associated with rural water supply failure: A 30-year retrospective study of handpumps on the south coast of Kenya.

An improved understanding of failure risks for water supplies in rural sub-Saharan Africa will be critical to achieving the global goal of safe water for all by 2030. In the absence of longitudinal biophysical and operational data, investigations into water point failure risk factors have to date been limited to cross-sectional research designs. This retrospective cohort study applies survival analysis to identify factors that predict failure risks for handpumps installed on boreholes along the south coast of Kenya from the 1980s. The analysis is based on a unique dataset linking attributes of >300 water points at the time of installation with their operational lifespan over the following decades. Cox proportional hazards and accelerated failure time models suggest water point failure risks are higher and lifespans are shorter when water supplied is more saline, static water level is deeper, and groundwater is pumped from an unconsolidated sand aquifer. The risk of failure also appears to grow as distance to spare part suppliers increases. To bolster the sustainability of rural water services and ensure no community is left behind, post-construction support mechanisms will need to mitigate heterogeneous environmental and geographical challenges. Further studies are needed to better understand the causal pathways that underlie these risk factors in order to inform policies and practices that ensure water services are sustained even where unfavourable conditions prevail.