Are interventions to reduce the impact of arsenic contamination of groundwater on human health in developing countries effective? A systematic review

BackgroundWithin developing countries, groundwater provides an alternative drinking source to polluted surface water. However, the presence of arsenic in some groundwater sources has resulted in chronic worldwide poisoning. The aim of this review was to determine the effectiveness of field-based technologies for the removal of arsenic from groundwater in developing countries.MethodsA structured search strategy was conducted in a range of databases. Titles, abstracts and full texts were screened using pre-defined inclusion criteria. Included studies were quality appraised prior to data extraction. The primary outcome was the percentage of effluent water samples meeting WHO guidelines for arsenic concentrations (≤0.01 mg/L). Secondary outcomes included: (a) arsenic concentrations in effluent water samples meeting the national guideline limit (≤0.05 mg/L), (b) arsenic concentrations in human tissue, and (c) knowledge and attitudes related to the interventions.ResultsFifty-one reports, evaluating 50 different technologies, were included. Sixty-seven percent (n = 34) of studies were conducted in Bangladesh. Fifty of the included reports were appraised as ‘weak’, with one ‘strong’ report of a randomised-controlled trial.In summary, the effectiveness of the oxidation and filtration interventions is poor, while the evidence for coagulation, co-precipitation and filtration, subterranean and membrane and electrolytic methods is mixed. Evidence regarding adsorption and zero valent iron interventions is more persuasive with most results suggesting good evidence of effectiveness (i.e. ≥95% of samples with arsenic concentrations ≤0.01 mg/L). In particular, activated alumina and sono/three-kolshi/gagri/pitcher filters have ≥95% of samples meeting national guidelines. Disappointingly, only one study reports excellent evidence of effectiveness: BRAC (2000) for activated alumina (i.e. ≥95% of samples with arsenic concentrations ≤0.01 mg/L).The success of each technology was highly dependent on context, especially their acceptability to users, a sense of ownership and expectations of women’s roles in society.ConclusionsMost studies were poorly conducted and reported. Consequently, although some technologies met national guidelines, the evidence-base for decision-making regarding arsenic mitigation technologies at household- and community-level is weak. To improve this situation, primary research needs to be commissioned with adequate sample sizes, testing the impact of key contextual factors, using valid tools for analysis, and meeting standards for completeness of reporting

Stay home, stay active with superjump®: A home-based activity to prevent sedentary lifestyle during covid-19 outbreak

The purpose of this study was to investigate the intensity of SuperJump® workout as a home-based activity for fulfilling physical activity recommendations during COVID-19 home-confinement. Seventeen (males: n = 10; females: n = 7) college students (age: 25.8 ± 2.7 years; height: 1.7 ± 0.1 m; weight: 66.2 ± 12.1 kg) participated in the study. To assess the intensity of the activity (30-min), heart rate (HR), expressed as percentages of age-predicted maximal HR (%HRmax), and session ratings of perceived exertion (sRPE), collected on a CR10 scale, were used. %HRmax data were categorically separated in five classes of intensity according to the American College of Sport Science’s guidelines. Enjoyment was evaluated using the Physical Activity Enjoyment Scale (PACES). Repeated measures ANOVA was used to evaluate differences (p < 0.05) in relation to gender and exercise intensity. No gender difference emerged for %HRmax and sRPE. Significantly higher (p < 0.05) %HRmax were found for the moderate intensity (47.1 ± 34.4%) with respect to very light (3.6 ± 6.9%), light (14.5 ± 23.3%) and vigorous (34.6 ± 39.6%) and for the vigorous intensity with respect to very light; no near maximal to maximal values were observed. Subjects perceived SuperJump® as moderate (sRPE = 3.1 ± 1.2) while showing high levels of enjoyability (PACES = 86.6 ± 16.2%). SuperJump® can be classified as moderate-to-vigorous activity, representing an effective alternative and enjoyable home-based activity for preventing the effects of a sedentary lifestyle during home-confinement

Ion Channel Clustering at the Axon Initial Segment and Node of Ranvier Evolved Sequentially in Early Chordates

In many mammalian neurons, dense clusters of ion channels at the axonal initial segment and nodes of Ranvier underlie action potential generation and rapid conduction. Axonal clustering of mammalian voltage-gated sodium and KCNQ (Kv7) potassium channels is based on linkage to the actin–spectrin cytoskeleton, which is mediated by the adaptor protein ankyrin-G. We identified key steps in the evolution of this axonal channel clustering. The anchor motif for sodium channel clustering evolved early in the chordate lineage before the divergence of the wormlike cephalochordate, amphioxus. Axons of the lamprey, a very primitive vertebrate, exhibited some invertebrate features (lack of myelin, use of giant diameter to hasten conduction), but possessed narrow initial segments bearing sodium channel clusters like in more recently evolved vertebrates. The KCNQ potassium channel anchor motif evolved after the divergence of lampreys from other vertebrates, in a common ancestor of shark and humans. Thus, clustering of voltage-gated sodium channels was a pivotal early innovation of the chordates. Sodium channel clusters at the axon initial segment serving the generation of action potentials evolved long before the node of Ranvier. KCNQ channels acquired anchors allowing their integration into pre-existing sodium channel complexes at about the same time that ancient vertebrates acquired myelin, saltatory conduction, and hinged jaws. The early chordate refinements in action potential mechanisms we have elucidated appear essential to the complex neural signaling, active behavior, and evolutionary success of vertebrates

DREADDs in Drosophila: A Pharmacogenetic Approach for Controlling Behavior, Neuronal Signaling, and Physiology in the Fly

SummaryWe have translated a powerful genetic tool, designer receptors exclusively activated by designer drugs (DREADDs), from mammalian systems to Drosophila melanogaster to selectively, rapidly, reversibly, and dose-dependently control behaviors and physiological processes in the fly. DREADDs are muscarinic acetylcholine G protein-coupled receptors evolved for loss of affinity to acetylcholine and for the ability to be fully activated by an otherwise biologically inert chemical, clozapine-N-oxide. We demonstrate its ability to control a variety of behaviors and processes in larvae and adults, including heart rate, sensory processing, diurnal behavior, learning and memory, and courtship. The advantages of this particular technology include the dose-responsive control of behaviors, the lack of a need for specialized equipment, and the capacity to remotely control signaling in essentially all neuronal and nonneuronal fly tissues

The Bioreduction of Selenite under Anaerobic and Alkaline Conditions Analogous to Those Expected for a Deep Geological Repository System

The environmental conditions for the planned geological disposal of radioactive waste —including hyper-alkaline pH, radiation or anoxia—are expected to be extremely harsh for microbial activity. However, it is thought that microbial communities will develop in these repositories, and this would have implications for geodisposal integrity and the control of radionuclide migration through the surrounding environment. Nuclear waste contains radioactive isotopes of selenium (Se) such as 79Se, which has been identified as one of the main radionuclides in a geodisposal system. Here, we use the bacterial species Stenotrophomonas bentonitica, isolated from bentonites serving as an artificial barrier reference material in repositories, to study the reduction of selenite (SeIV) under simulated geodisposal conditions. This bacterium is able to reduce toxic SeIV anaerobically from a neutral to alkaline initial pH (up to pH 10), thereby producing elemental selenium (Se0) nanospheres and nanowires. A transformation process from amorphous Se (a-Se) nanospheres to trigonal Se (t-Se) nanowires, through the formation of monoclinic Se (m-Se) aggregates as an intermediate step, is proposed. The lesser solubility of Se0 and t-Se makes S. bentonitica a potential candidate to positively influence the security of a geodisposal system, most probably with lower efficiency rates than those obtained aerobically.This work was supported by the Euratom research and training programme 2014–2018 under grant agreement no. 66188

Achieving the Millennium Development Goals: Does Mental Health Play a Role?

Miranda and Patel argue that mental disorders are among the most important causes of disability and premature mortality in developing countries

Compendium of Single Event Effects Test Results for Commercial Off-The-Shelf and Standard Electronics for Low Earth Orbit and Deep Space Applications

We present the results of Single Event Effects (SEE) testing with high energy protons and with low and high energy heavy ions for electrical components considered for Low Earth Orbit (LEO) and for deep space applications