As non-biological molecules, molecular imprinted polymers (MIPs) can be made as antibody mimics for the development of luminescence sensors for various targets. The combination of MIPs with nanomaterials is further recognized as a useful option to improve the sensitivity of luminescence sensors. In this work, the recent progresses made in the fabrication of fluorescence, phosphorescence, chemiluminescence, and electrochemiluminescence sensors based on such combination have been reviewed with emphasis on the detection of pesticides/herbicides. Accordingly, the materials that are most feasible for the detection of such targets are recommended based on the MIP technologies.

Land use change affects the supply and demand of water, energy and food and the integration of land elements into the common water-energy-food (WEF) nexus, which is an effective way to strictly adhere to the bottom line of natural resources. First, this study used the entropy method and coupling coordination model to measure the coupling coordination degree of the water-energy-land-food (WELF) nexus in 30 provinces in China during the period of 2006–2019. Then, the regional differences and distribution dynamics were examined with the Dagum Gini coefficient and Kernel density estimation, respectively. Finally, the spatial correlation was analyzed using the global Moran’s I, and a spatial β convergence model was constructed to empirically test its spatial β convergence characteristics. The results show that the coupling coordination degree of the WELF nexus in most of the provinces was at the stage of barely coordinated, with a decreasing trend; the intensity of transvariation was the main source of regional differences in the coupling coordination degree of the WELF nexus, followed by intra-regional differences, while inter-regional differences were small. The national, eastern and central regions had a slight gradient effect, showing regional dispersion characteristics, albeit less obvious; there was a spatial absolute-β convergence and spatial conditional-β convergence nationally and in the three regions. On this basis, policy recommendations were made to realize the synergistic development of land planning, water resources allocation, energy utilization, and food production and to balance regional differences in resources.

The energy demand in South Asia is increasing at a rapid rate and it is becoming harder to meet the demand due to the high cost of conventional energy sources, the unsustainability of energy use, and the high emissions caused by the energies. South Asia is blessed with a high potential for renewable energy, especially hydropower, but that has not been adequately tapped. This has highly compromised the food, water, and energy security of the people in South Asian countries. This article identifies the roles of renewable energy sources in achieving energy, water, and food security for South Asian nations and provides suggestions for enhancing the utilization of renewable resources. The article identifies the potential for the promotion of hydropower and other renewable energy sources as well as opportunities and potential challenges for multilateral energy trade for increasing the availability of energy. It also recommends possible solutions and approaches for the promotion of hydropower and other renewables in South Asia. The article infers that a nexus approach for integrated planning, policy coherence, and institutional harmonization increases the benefit by reducing transaction costs, generating additional synergies, and reducing the trade-off at different scales. These approaches enhance energy, food, and water security, and eventually improve the quality of life in the region. Improved access to renewable energy can contribute directly and indirectly to achieving Sustainable Development Goals (SDGs) in this region.

Introduction Stunting or linear growth faltering, measured by length-for-age Z-score (LAZ), remains a significant public health challenge, particularly in rural low-income and middle-income countries. It is a marker of inadequate environments in which infants are born and raised. However, the contributions of household resource insecurities, such as food and water, to growth and growth trajectory are understudied. Methods We used the cluster-randomised Sanitation Hygiene and Infant Nutrition Efficacy trial to determine the association of household-level food insecurity (FI) and water insecurity (WI) on LAZ and LAZ trajectory among infants during early life. Dimensions of FI (poor access, household shocks, low availability and quality) and WI (poor access, poor quality, low reliability) were assessed with the multidimensional household food insecurity and the multidimensional household water insecurity measures. Infant length was converted to LAZ based on the 2006 WHO Child Growth Standards. We report the FI and WI fixed effects from multivariable growth curve models with repeated measures of LAZ at 1, 3, 6, 12 and 18 months (M1–M18). Results A total of 714 and 710 infants were included in our analyses of LAZ from M1 to M18 and M6 to M18, respectively. Mean LAZ values at each time indicated worsening linear growth. From M1 to M18, low food availability and quality was associated with lower LAZ (β=−0.09; 95% −0.19 to –0.13). From M6 to M18, poor food access was associated with lower LAZ (β=−0.11; 95% −0.20 to –0.03). None of the WI dimensions were associated with LAZ, nor with LAZ trajectory over time. Conclusion FI, but not WI, was associated with poor linear growth among rural Zimbabwean infants. Specifically, low food availability and quality and poor food access was associated with lower LAZ. There is no evidence of an effect of FI or WI on LAZ trajectory.

The present study aims to identify and quantify the phenolic compounds of Azadirachta indica leaf extract using HPLC-MS and to evaluate the antioxidant, antibacterial (against different Gram-positive and negative bacteria) and in vitro anti-proliferative activities of this extract (against breast, human liver and cervix adenocarcinoma-derived cells). The application of this extract as a natural antioxidant for food preservation was also tested on oil-in-water food emulsions for the first time in the present work in order to determine the use of Azadirachta indica leaves as a natural additive to preserve the food against lipid oxidation and rancidity. The results obtained revealed that 50%-aqueous ethanol leaf extract showed the best extraction yield (25.14%), which was characterized by a high content in phenolic compounds and strong antioxidant activity. Moreover, this leaf extract inhibited the growth of the bacterial strains tested (Staphylococcus aureus, Escherichia coli, Salmonella paratyphi and Micrococcus luteus) and showed better anti-proliferative activity against breast and cervix adenocarcinoma-derived cells than human liver cancer cells after 48 h of treatment. Additionally, Azadirachta indica leaf extract showed almost similar effects as gallic acid solutions (0.25% and 0.5%) in preserving the oxidation of oil-in-water food emulsions and prevented the formation of secondary oxidation products (malondialdehyde) as well. The results obtained suggested that extracts of Azadirachta indica leaves are a potential source of antioxidant and antibacterial compounds and pointed to the potential of these natural extracts as therapeutic agents.

There is limited focus on the water-energy-food (WEF) nexus approach at the local scale, particularly considering the social contexts of neglected territories. To contribute to this debate, we propose a framework to address this topic in an area in Angra dos Reis, Rio de Janeiro State, Brazil, as a case study. A survey was conducted regarding residents’ perceptions, choices, practices and access to water, energy, and food. The interviews highlighted important topics on the WEF nexus. As a result, a set of 12 indicators with data available on official datasets was proposed, reflecting residents’ perceptions of WEF safety. For each indicator, thresholds were established based mainly on the goals defined by Brazilian policies across different spheres—federal, state, or municipal. Thus, each indicator is multi-scale and integrative, since it comprises a local perspective (from the interview results), an official perspective (from the official databases), and a threshold. The results showed problems with energy and water supply, and the presence of home cropping, contrasting with residents who do not have access to basic food and experience extreme poverty. All these elements drew attention to the possibility of applying the WEF nexus approach, searching for feasible solutions which can support better decisions and governance in neglected territories.

There is limited focus on the water-energy-food (WEF) nexus approach at the local scale, particularly considering the social contexts of neglected territories. To contribute to this debate, we propose a framework to address this topic in an area in Angra dos Reis, Rio de Janeiro State, Brazil, as a case study. A survey was conducted regarding residents’ perceptions, choices, practices and access to water, energy, and food. The interviews highlighted important topics on the WEF nexus. As a result, a set of 12 indicators with data available on official datasets was proposed, reflecting residents’ perceptions of WEF safety. For each indicator, thresholds were established based mainly on the goals defined by Brazilian policies across different spheres—federal, state, or municipal. Thus, each indicator is multi-scale and integrative, since it comprises a local perspective (from the interview results), an official perspective (from the official databases), and a threshold. The results showed problems with energy and water supply, and the presence of home cropping, contrasting with residents who do not have access to basic food and experience extreme poverty. All these elements drew attention to the possibility of applying the WEF nexus approach, searching for feasible solutions which can support better decisions and governance in neglected territories.

Department of Geography and Environmental Sciences | Department of Geography and Environmental Sciences | Globally, the occurrence of cyanobacterial blooms in freshwater ecosystems has become a concern. Cyanobacteria produces secondary metabolites, known as cyanotoxins that cause acute and chronic poisoning in animals and humans. History of mining, industrial activities and poor maintenance of wastewater treatment infrastructure are the main causes of the hyper-eutrophic conditions affecting most dams in South Africa. The co-occurrence of multiple stressors in agricultural waters and soils potentially pose a human and animal risk if contaminated water and plants are ingested. The study investigated the co-existence of cyanotoxins, anionic surfactants and metal species in irrigation water, agricultural soils and food crops and determine the health risks associated with consuming cyanotoxins contaminated plants in the Crocodile (West) Marico Water Management Area, which covers parts of Gauteng and Northwest Provinces. Lastly, the study assessed the applicability of passive sampling technology in monitoring of cyanotoxins using DIAON HP20 resins as an adsorbent. Water, food crops and soil samples were collected from Roodeplaat and Hartbeespoort dam sites in irrigation canals and cropping fields in June 2019, September 2019, February 2020, and March 2021. Seven sites were selected for sampling of water for cyanotoxins, anionic surfactants and toxic metals, while 4 farmland sites were selected for agricultural soils and food crops in Roodeplaat and Hartbeespoort sites. Physicochemical parameters of the irrigation water (pH, temperature, EC, TDS, DO), chlorophyll-a and dissolved nutrients were also monitored using Spectrophotometer and Spectro-Quant® Merck Pharo 100 with the photo-metric test kits from Merck, respectively. The levels of Microcystins (MCs), anionic surfactants, and metals were detected and quantified using the ELISA method, anionic surfactant portable photometer and inductively coupled plasma mass spectrometry (ICP- MS), respectively. The results are presented for each chapters below. The results for chapter 1 revealed the co-existence of cyanotoxins, metal species and anionic surfactants in the irrigation water, and agricultural soils, across sampling sites, throughout sampling period. The microcystins in irrigation water ranged from 0.00 to 15.57 μg/L. Total anionic surfactants in irrigation water and agricultural soil ranged from 0.01 to 3.49 mg/L and 1.81 to 5.46 mg/kg, respectively. Among all the physicochemical parameters only pH (p = 0.624), TDS (p = - 0.466), EC (p = - 0.445), and turbidity (p = 0.521) correlated with MCs. Moreover, total anionic surfactant showed to have positive moderate relationship with levels of MCs in irrigation water (p = 0.342). Metal species in irrigation water were decreased in the following order: Al > Mn > Fe > B > Zn > Ni > Cu > Pb > Cr > As and were all below the maximum DWAF acceptable limit, implying that the water was safe for irrigation use. Metal species in other soil sampling sites such as 16534.61 – 33285 mg/kg (Fe), 111.25 – 723.4 mg/kg (Cr),4.44 – 23.93 mg/kg (Pb), 0.80 – 9.70 mg/kg (As), 22.11 – 33.95 mg/kg (Cu), and 33.70 – 85.885 mg/kg (Ni) were above the maximum limit set by DEA, USEPA, and FAO/WHO for agricultural use. Thus, soils from Roodeplaat and Hartbeespoort farmland sites are contaminated by the mentioned metals. The findings from the second chapter of results revealed the bio-accumulation of microcystins and metals in food crops. The estimated daily intake (EDI) for MCs in all food crops for both adults and children were below 0.04 μg/kg DW acceptable value set by World Health Organisation, implying that the crops were safe for human consumption by adult and children population. Metal species levels accumulated in plant samples collected from different sampling sites, showed that 0.21 to 10.80 mg/kg (Cr), 19.64 to 734.00 mg/kg (Fe), 5.45 to 76.80 mg/kg (Zn), 0.01 to 0.20 mg/kg (As), 0.96 to 60.40 mg/kg (Cu), and 0.10 to 0.70 mg/kg (Pb) were above the EU and FAO/WHO guideline standards. Spearman correlation between metals in plants and water showed that only Pb (p = 0.874) and As (p = 0.809) in irrigation water had a positive moderate association with metals in plants collected from the sampling sites. The estimated daily intake (EDI) of metals via consumption of the crops were found to be below the maximum tolerable daily intake (MTDI) proposed for each metal. The translocation factors (TF) showed that only Cu and Cd were rapidly transported to the plant’s edible parts from the soil. Moreover, target hazard quotient (THQ) for each metal were below 1, indicating that consuming the food crops wont cause carcinogenic effect to the adult population, while hazard index (HI) for other sites was found to be >1 for crop plants, thus plants from these sites pose a health hazards to adult population. In addition, the target cancer risk (TCR) value for Cr and Ni in crops from other sampling sites were above the maximum threshold implying that there is a potential cancer risk to adult population over a long-term. In addition, findings from the third chapter showed that SPATT was applicable in monitoring and detecting MCs across all sampling sites and sampling months. The MCs levels in grab and SPATT bags ranged from 0.14 to 13.03 μg/L and 0.99 to 2.28 ng/g resin throughout the sampling sites and months, respectively. Thus, showing the persistence of MCs in canals and farm dams of Roodeplaat and Hartbeespoort. A spearman correlation revealed that pH (p = 0.776), Turbidity (p = 0.699) and DO (p = 0.829) had a significant positive association with total toxins in grab samples, while total dissolved MCs in SPATT samples showed negative moderate relationship with TDS (p = - 0.615) and EC (p = - 0.602). Total toxin concentrations in SPATT bags and Grab samples did not show any correlation this is because SPATT bags detect and collect microcystins within water column overtime, unlike point (Grab sampling), hence, there is no relationship between the two-sampling method. Overall results showed that SPATT bags with DIAON HP20 resin as an adsorbent proved to be applicable in monitoring and detecting microcystins in the irrigation water of Roodeplaat and Hartbeespoort sites. | NRF

The residues of antibiotics in the environment pose a potential health hazard, so highly sensitive detection of antibiotics has always appealed to analytical chemists. With the widespread use of new low-dimensional materials, graphene-modified electrochemical sensors have emerged as an excellent candidate for highly sensitive detection of antibiotics. Graphene, its derivatives and its composites have been used in this field of exploration in the last decade. In this review, we have not only described the field using traditional summaries, but also used bibliometrics to quantify the development of the field. The literature between 2011 and 2021 was included in the analysis. Also, the sensing performance and detection targets of different sensors were compared. We were able to trace not only the flow of research themes, but also the future areas of development. Graphene is a material that has a high potential to be used on a large scale in the preparation of electrochemical sensors. How to design a sensor with selectivity and low cost is the key to bring this material from the laboratory to practical applications.

Climate change, growing populations, and increasing wealth are increasing demand for food, energy, and water. Additionally, water stress is expected to increase in the future in areas with high rates of seasonality of precipitation, due to increased variability in precipitation. One approach to limiting the impact of climate change on food system productions is through the intensive and extensive expansion of irrigated agriculture. This study develops a hydro-economic model to assess future agriculture production possibilities and the role of irrigation water in the Pacific Slope region of Guatemala, one of the most productive agricultural regions in the country. A range of future scenarios are presented to account for uncertainty around irrigation infrastructure expansion, future crop prices, incentives for production of biomass for bioenergy, and water availability and irrigation demand due to climate change. We find that current surface water irrigation infrastructure increases agricultural output by value in the region by about 5.3% compared to a fully rainfed system. Additionally, we show that with expanded irrigation infrastructure, agricultural output could increase by between 3.4% and 18.4% relative to current levels under current climate conditions, but the value of agricultural production could increase under climate change with projected output from current and expanded irrigation infrastructure resulting in an increase of 1.2–24.8% relative to current irrigation levels. We also present evidence that the marginal benefit from increased irrigation access to smallholder farmers is nearly equal to that received by large-scale industrial agricultural producers.