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

Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection

<p>Abstract</p> <p>Background</p> <p>Parasites that manipulate host behavior can provide prominent examples of extended phenotypes: parasite genomes controlling host behavior. Here we focus on one of the most dramatic examples of behavioral manipulation, the death grip of ants infected by <it>Ophiocordyceps </it>fungi. We studied the interaction between <it>O. unilateralis s.l</it>. and its host ant <it>Camponotus leonardi </it>in a Thai rainforest, where infected ants descend from their canopy nests down to understory vegetation to bite into abaxial leaf veins before dying. Host mortality is concentrated in patches (graveyards) where ants die on sapling leaves <it>ca</it>. 25 cm above the soil surface where conditions for parasite development are optimal. Here we address whether the sequence of ant behaviors leading to the final death grip can also be interpreted as parasite adaptations and describe some of the morphological changes inside the heads of infected workers that mediate the expression of the death grip phenotype.</p> <p>Results</p> <p>We found that infected ants behave as zombies and display predictable stereotypical behaviors of random rather than directional walking, and of repeated convulsions that make them fall down and thus precludes returning to the canopy. Transitions from erratic wandering to death grips on a leaf vein were abrupt and synchronized around solar noon. We show that the mandibles of ants penetrate deeply into vein tissue and that this is accompanied by extensive atrophy of the mandibular muscles. This lock-jaw means the ant will remain attached to the leaf after death. We further present histological data to show that a high density of single celled stages of the parasite within the head capsule of dying ants are likely to be responsible for this muscular atrophy.</p> <p>Conclusions</p> <p>Extended phenotypes in ants induced by fungal infections are a complex example of behavioral manipulation requiring coordinated changes of host behavior and morphology. Future work should address the genetic basis of such extended phenotypes.</p

Student engagement and wellbeing over time at a higher education institution

Student engagement is an important factor for learning outcomes in higher education. Engagement with learning at campus-based higher education institutions is difficult to quantify due to the variety of forms that engagement might take (e.g. lecture attendance, self-study, usage of online/digital systems). Meanwhile, there are increasing concerns about student wellbeing within higher education, but the relationship between engagement and wellbeing is not well understood. Here we analyse results from a longitudinal survey of undergraduate students at a campus-based university in the UK, aiming to understand how engagement and wellbeing vary dynamically during an academic term. The survey included multiple dimensions of student engagement and wellbeing, with a deliberate focus on self-report measures to capture students' subjective experience. The results show a wide range of engagement with different systems and study activities, giving a broad view of student learning behaviour over time. Engagement and wellbeing vary during the term, with clear behavioural changes caused by assessments. Results indicate a positive interaction between engagement and happiness, with an unexpected negative relationship between engagement and academic outcomes. This study provides important insights into subjective aspects of the student experience and provides a contrast to the increasing focus on analysing educational processes using digital records

Defining a GP consultation

Introduction The method used to define a GP-consultation using routine data will vary depending on the data source and research question. However, without consensus the approach will be tackled by numerous researchers and invariably result in different definitions. The LUCI study is assessing outcomes of childhood UTI using routine data sources. Objectives and Approach We are interested in GP urine sampling rate and re-consultation rate. The GP dataset includes multiple clinical (acute, routine monitoring, prescribing, results) and administrative codes. A GP consultation therefore needed to be defined. GP read code frequencies for our study cohort of children were produced. One researcher reviewed the codes that represented 80% of the data and classified them as a consultation or not. Where there was uncertainty this was independently reviewed by two clinicians and discrepancies agreed by the management team. Results We will present the decisions and assumptions made for this study in defining a GP consultation. 25,623 Read Codes represented the consultations for our study cohort of which 460 codes represented 80% of the consultations. The remaining 20% of codes represented <0.032% of records each. The 460 Read Codes were reviewed and following independent review and agreement from the management group 149 Read Codes were excluded. These were grouped into the following categories Administrative (e.g. Incoming Mail Processing, Ethnicity codes), Vaccinations, Child Health (e.g. First Smiled), Asthma and Medication Review. The GP consultations to be included in the analysis were then restricted to exclude these codes. This has been an important step in cleaning and understanding the data prior to analysis. Conclusion/Implications A consultation was defined for this study however there will be pros and cons to this method. In lieu of a consensus approach to the method this work is the first step to sharing approaches to help researchers with the same challenge

Organ-on-a-chip: current gaps and future directions.

As an emerging hot topic of the last decade, Organ on Chip (OoC) is a new technology that is attracting interest from both basic and translational scientists. The Biochemical Society, with its mission of supporting the advancement of science, with addressing grand challenges that have societal impact, has included OoC into their agenda to review the current state of the art, bottlenecks and future directions. This conference brought together representatives of the main stakeholders in the OoC field including academics, end-users, regulators and technology developers to discuss and identify requirements for this new technology to deliver on par with the expectations and the key challenges and gaps that still need to be addressed to achieve robust human-relevant tools, able to positively impact decision making in the pharmaceutical industry and reduce overreliance on poorly predictive animal models

Long-term outcomes of urinary tract infection (UTI) in Childhood (LUCI): protocol for an electronic record-linked cohort study

Funding This project has been funded by the Welsh Government through Health and Care Research Wales (project number 1068). Acknowledgments We acknowledge the support and input from Sarah Jones, our parent representative for the study. We are also grateful to the DUTY and EURICA participants for their agreement for continued use of their data for this study. The Centre for Trials Research receives funding from Health and Care Research Wales and Cancer Research UK. Wales Centre for Primary and Emergency Care Research (PRIME Centre Wales) receives funding from Health and Care Research Wales. The authors are supported by the Farr Institute CIPHER, funded by Arthritis Research UK, the British Heart Foundation, Cancer Research UK, the Economic and Social Research Council, the Engineering and Physical Sciences Research Council, the Medical Research Council, the National Institute of Health Research, the National Institute for Social Care and Health Research (Welsh Assembly Government), the Chief Scientist Office (Scottish Government Health Directorates), and the Wellcome Trust (MRC grant number MR/K006525/1) and the National Centre for Population Health and Wellbeing Research (NCPHWR). Ethics approval Ethics approval of the study has been given by the Research Ethics Committee for Wales (16/WA/0166) and the transfer and use of identifiable data has been approved by the Health Research Authority’s (HRA) Confidentiality Advisory Group (CAG) (16/CAG/0114).Peer reviewedPublisher PD

The Life of a Dead Ant:The Expression of an Adaptive Extended Phenotype

Specialized parasites are expected to express complex adaptations to their hosts. Manipulation of host behavior is such an adaptation. We studied the fungus Ophiocordyceps unilateralis, a locally specialized parasite of arboreal Camponotus leonardi ants. Ant-infecting Ophiocordyceps are known to make hosts bite onto vegetation before killing them. We show that this represents a fine-tuned fungal adaptation: an extended phenotype. Dead ants were found under leaves, attached by their mandibles, on the northern side of saplings similar to 25 cm above the soil, where temperature and humidity conditions were optimal for fungal growth. Experimental relocation confirmed that parasite fitness was lower outside this manipulative zone. Host resources were rapidly colonized and further secured by extensive internal structuring. Nutritional composition analysis indicated that such structuring allows the parasite to produce a large fruiting body for spore production. Our findings suggest that the osmotrophic lifestyle of fungi may have facilitated novel exploitation strategies

Graveyards on the Move: The Spatio-Temporal Distribution of Dead Ophiocordyceps-Infected Ants

Parasites are likely to play an important role in structuring host populations. Many adaptively manipulate host behaviour, so that the extended phenotypes of these parasites and their distributions in space and time are potentially important ecological variables. The fungus Ophiocordyceps unilateralis, which is pan-tropical in distribution, causes infected worker ants to leave their nest and die under leaves in the understory of tropical rainforests. Working in a forest dynamic plot in Southern Thailand we mapped the occurrence of these dead ants by examining every leaf in 1,360 m2 of primary rainforest. We established that high density aggregations exist (up to 26 dead ants/m2), which we coined graveyards. We further established that graveyards are patchily distributed in a landscape with no or very few O. unilateralis-killed ants. At some, but not all, spatial scales of analysis the density of dead ants correlated with temperature, humidity and vegetation cover. Remarkably, having found 2243 dead ants inside graveyards we only found 2 live ants of the principal host, ant Camponotus leonardi, suggesting that foraging host ants actively avoid graveyards. We discovered that the principal host ant builds nests in high canopy and its trails only occasionally descend to the forest floor where infection occurs. We advance the hypothesis that rare descents may be a function of limited canopy access to tree crowns and that resource profitability of such trees is potentially traded off against the risk of losing workers due to infection when forest floor trails are the only access routes. Our work underscores the need for an integrative approach that recognises multiple facets of parasitism, such as their extended phenotypes

Data-driven inverse modelling through neural network (deep learning) and computational heat transfer

In this work, the potential of carrying out inverse problems with linear and non-linear behaviour is investigated using deep learning methods. In inverse problems, the boundary conditions are determined using sparse measurement of a variable such as velocity or temperature. Although this is mathematically tractable for simple problems, it can be extremely challenging for complex problems. To overcome the non-linear and complex effects, a brute force approach was used on a trial and error basis to find an approximate solution. With the advent of machine learning algorithms it may now be possible to model inverse problems faster and more accurately. In order to demonstrate that machine learning can be used in solving inverse problems, we propose a fusion between computational mechanics and machine learning. The forward problems are solved first to create a database. This database is then used to train the machine learning algorithms. The trained algorithm is then used to determine the boundary conditions of a problem from assumed measurements. The proposed method is tested for the linear/non-linear heat conduction, convection–conduction, and natural convection problems in which the boundary conditions are determined by providing three, four, and five temperature measurements. This study demonstrates that the proposed fusion of computational mechanics and machine learning is an effective way of tackling complex inverse problems