Preferences and constraints: the value of economic games for studying human behaviour

© 2020 The Authors. As economic games have spread from experimental economics to other social sciences, so too have critiques of their usefulness for drawing inferences about the ‘real world’. What these criticisms often miss is that games can be used to reveal individuals' private preferences in ways that observational and interview data cannot; furthermore, economic games can be designed such that they do provide insights into real-world behaviour. Here, we draw on our collective experience using economic games in field contexts to illustrate how researchers can strategically alter the framing or design of economic games to draw inferences about private-world or real-world preferences. A detailed case study from coastal Colombia provides an example of the subtleties of game design and how games can be combined fruitfully with self-report data. We close with a list of concrete recommendations for how to modify economic games to better match particular research questions and research contexts.Max Planck Institute for Evolutionary Anthropolog

Isoniazid Preventive Therapy Added to ART to Prevent TB: An Individual Participant Data Meta-Analysis

Background: Isoniazid preventive therapy prevents active tuberculosis in people with HIV, but previous studies have found no evidence of benefit in people with HIV who had a negative tuberculin skin test, and a non-significant effect on mortality. We aimed to estimate the effect of isoniazid preventive therapy given with antiretroviral therapy (ART) for the prevention of tuberculosis and death among people with HIV across population subgroups. Methods: We searched PubMed, Embase, the Cochrane database, and conference abstracts from database inception to Jan 15, 2019, to identify potentially eligible randomised trials. Eligible studies were trials that enrolled HIV-positive adults (age ≥15 years) taking ART who were randomly assigned to either daily isoniazid preventive therapy plus ART or ART alone and followed up longitudinally for outcomes of incident tuberculosis and mortality. We approached all authors of included trials and requested individual participant data: coprimary outcomes were relative risk of incident tuberculosis and all-cause mortality. We did a single-stage meta-analysis of individual participant data using stratified Cox-proportional hazards models. We did prespecified subgroup analyses by sex, CD4 cell count, and evidence of immune sensitisation to tuberculosis (indicated by tuberculin skin test or interferon-γ release assays [IGRAs]). We also assessed the relative risk of liver injury in an additional prespecified analysis. This study is registered with PROSPERO, CRD42019121400. Findings: Of 838 records, we included three trials with data for 2611 participants and 8584·8 person-years of follow-up for the outcome of incident tuberculosis, and a subset of 2362 participants with 8631·6 person-years of follow-up for the coprimary outcome of all-cause mortality. Risk for tuberculosis was lower in participants given isoniazid preventive therapy and ART than participants given ART alone (hazard ratio [HR] 0·68, 95% CI 0·49–0·95, p=0·02). Risk of all-cause mortality was lower in participants given isoniazid preventive therapy and ART than participants given ART alone, but this difference was non-significant (HR 0·69, 95% CI 0·43–1·10, p=0·12). Participants with baseline CD4 counts of less than 500 cells per μL had increased risk of tuberculosis, but there was no significant difference in the benefit of isoniazid preventive therapy with ART by sex, baseline CD4 count, or results of tuberculin skin test or IGRAs. 65 (2·5%) of 2611 participants had raised alanine aminotransferase, but data were insufficient to calculate an HR. Interpretation: Isoniazid preventive therapy with ART prevents tuberculosis across demographic and HIV-specific and tuberculosis-specific subgroups, which supports efforts to further increase use of isoniazid preventive therapy with ART broadly among people living with HIV. Funding: National Institutes of Health and National Institute of Allergy and Infectious Diseases

Glucocorticoids regulate AKR1D1 activity in human liver in vitro and in vivo

Steroid 5β-reductase (AKR1D1) is highly expressed in human liver where it inactivates endogenous glucocorticoids and catalyses an important step in bile acid synthesis. Endogenous and synthetic glucocorticoids are potent regulators of metabolic phenotype and play a crucial role in hepatic glucose metabolism. However, the potential of synthetic glucocorticoids to be metabolised by AKR1D1 as well as to regulate its expression and activity has not been investigated. The impact of glucocorticoids on AKR1D1 activity was assessed in human liver HepG2 and Huh7 cells; AKR1D1 expression was assessed by qPCR and Western blotting. Genetic manipulation of AKR1D1 expression was conducted in HepG2 and Huh7 cells and metabolic assessments were made using qPCR. Urinary steroid metabolite profiling in healthy volunteers was performed pre- and post-dexamethasone treatment, using gas chromatography-mass spectrometry. AKR1D1 metabolised endogenous cortisol, but cleared prednisolone and dexamethasone less efficiently. In vitro and in vivo, dexamethasone decreased AKR1D1 expression and activity, further limiting glucocorticoid clearance and augmenting action. Dexamethasone enhanced gluconeogenic and glycogen synthesis gene expression in liver cell models and these changes were mirrored by genetic knockdown of AKR1D1 expression. The effects of AKR1D1 knockdown were mediated through multiple nuclear hormone receptors, including the glucocorticoid, pregnane X and farnesoid X receptors. Glucocorticoids down-regulate AKR1D1 expression and activity and thereby reduce glucocorticoid clearance. In addition, AKR1D1 down-regulation alters the activation of multiple nuclear hormone receptors to drive changes in gluconeogenic and glycogen synthesis gene expression profiles, which may exacerbate the adverse impact of exogenous glucocorticoids

Widespread sex differences in gene expression and splicing in the adult human brain

There is strong evidence to show that men and women differ in terms of neurodevelopment, neurochemistry and susceptibility to neurodegenerative and neuropsychiatric disease. The molecular basis of these differences remains unclear. Progress in this field has been hampered by the lack of genome-wide information on sex differences in gene expression and in particular splicing in the human brain. Here we address this issue by using post-mortem adult human brain and spinal cord samples originating from 137 neuropathologically confirmed control individuals to study whole-genome gene expression and splicing in 12 CNS regions. We show that sex differences in gene expression and splicing are widespread in adult human brain, being detectable in all major brain regions and involving 2.5% of all expressed genes. We give examples of genes where sex-biased expression is both disease-relevant and likely to have functional consequences, and provide evidence suggesting that sex biases in expression may reflect sex-biased gene regulatory structures

Extracellular Matrix Aggregates from Differentiating Embryoid Bodies as a Scaffold to Support ESC Proliferation and Differentiation

Embryonic stem cells (ESCs) have emerged as potential cell sources for tissue engineering and regeneration owing to its virtually unlimited replicative capacity and the potential to differentiate into a variety of cell types. Current differentiation strategies primarily involve various growth factor/inducer/repressor concoctions with less emphasis on the substrate. Developing biomaterials to promote stem cell proliferation and differentiation could aid in the realization of this goal. Extracellular matrix (ECM) components are important physiological regulators, and can provide cues to direct ESC expansion and differentiation. ECM undergoes constant remodeling with surrounding cells to accommodate specific developmental event. In this study, using ESC derived aggregates called embryoid bodies (EB) as a model, we characterized the biological nature of ECM in EB after exposure to different treatments: spontaneously differentiated and retinoic acid treated (denoted as SPT and RA, respectively). Next, we extracted this treatment-specific ECM by detergent decellularization methods (Triton X-100, DOC and SDS are compared). The resulting EB ECM scaffolds were seeded with undifferentiated ESCs using a novel cell seeding strategy, and the behavior of ESCs was studied. Our results showed that the optimized protocol efficiently removes cells while retaining crucial ECM and biochemical components. Decellularized ECM from SPT EB gave rise to a more favorable microenvironment for promoting ESC attachment, proliferation, and early differentiation, compared to native EB and decellularized ECM from RA EB. These findings suggest that various treatment conditions allow the formulation of unique ESC-ECM derived scaffolds to enhance ESC bioactivities, including proliferation and differentiation for tissue regeneration applications. © 2013 Goh et al

Strategies and Practices in Off-Label Marketing of Pharmaceuticals: A Retrospective Analysis of Whistleblower Complaints

Aaron Kesselheim and colleagues analyzed unsealed whistleblower complaints against pharmaceutical companies filed in US federal fraud cases that contained allegations of off-label marketing, and develop a taxonomy of the various off-label practices

Why it takes an 'ontological shock' to prompt increases in small firm resilience : sensemaking, emotions and flood risk

This article uses a sensemaking approach to understand small firms’ responses to the threat of external shocks. By analysing semi-structured interviews with owners of flooded small firms, we investigate how owners process flood experiences and explore why such experiences do not consistently lead to the resilient adaptation of premises. We, conclude that some of the explanation for low levels of adaptation relates to a desire to defend existing sensemaking structures and associated identities. Sensemaking structures are only revised if these structures are not critical to business identity, or if a flood constitutes an ‘ontological shock’ and renders untenable existing assumptions regarding long-term business continuity. This article has implications for adaptation to the growing risk of flooding, climate change and external shocks. Future research analysing external shocks would benefit from using a sensemaking approach and survey studies should include measurements of ‘ontological’ impact as well as material and financial damage. In addition, those designing information campaigns should take account of small firms’ resistance to information that threatens their existing sensemaking structures and social identities

Patients' constructions of disability in metastatic spinal cord compression

Metastatic spinal cord compression (MSCC) is characterised by poor prognosis and serious physical disability. Patients have complex rehabilitation needs, but the evidence on rehabilitation is sparse. This study aimed to ascertain the constructions placed upon disability by patients with MSCC. A series of nine process-tracing, longitudinal case studies, involving 58 interviews with 9 patients, 6 carers, and 29 staff in one NHS region. A context-mechanism-outcome configuration was adopted as a conceptual basis for data collection, together with a constant comparative method of data analysis. Patients’ orientation to disability incorporated two apparently inconsistent attitudes. Patients acknowledged that their situation had changed, and that their future plans would need to accommodate altered circumstances. However, they also resisted the idea of themselves as disabled, wanting to retain an image of themselves as resourceful and resilient. Patients used a number of strategies to reconcile the tension between these two positions. The illusions incorporated into the ‘failure to acknowledge’ pole of this orientation are self-protective and, like other positive illusions, have psychological benefits. Providing effective and acceptable support to patients living with disability relies on professional responses that are able to sustain patients’ sense of their own competence

In one’s own time: Contesting the temporality and linearity of bereavement

This article explores the experience and meaning of time from the perspective of caregivers who have recently been bereaved following the death of a family member. The study is situated within the broader cultural tendency to understand bereavement within the logic of stages, including the perception of bereavement as a somewhat predictable and certainly time-delimited ascent from a nadir in death to a ‘new normal’ once loss is accepted. Drawing on qualitative data from interviews with 15 bereaved family caregivers we challenge bereavement as a linear, temporally bound process, examining the multiple ways bereavement is experienced and how it variously resists ideas about the timeliness, desirability and even possibility of ‘recovery’. We posit, on the basis of these accounts, that the lived experience of bereavement offers considerable challenges to normative understandings of the social ties between the living and the dead and requires a broader reconceptualization of bereavement as an enduring affective state

Estimation of heterogeneity in malaria transmission by stochastic modelling of apparent deviations from mass action kinetics

<p>Abstract</p> <p>Background</p> <p>Quantifying heterogeneity in malaria transmission is a prerequisite for accurate predictive mathematical models, but the variance in field measurements of exposure overestimates true micro-heterogeneity because it is inflated to an uncertain extent by sampling variation. Descriptions of field data also suggest that the rate of <it>Plasmodium falciparum </it>infection is not proportional to the intensity of challenge by infectious vectors. This appears to violate the principle of mass action that is implied by malaria biology. Micro-heterogeneity may be the reason for this anomaly. It is proposed that the level of micro-heterogeneity can be estimated from statistical models that estimate the amount of variation in transmission most compatible with a mass-action model for the relationship of infection to exposure.</p> <p>Methods</p> <p>The relationship between the entomological inoculation rate (EIR) for falciparum malaria and infection risk was reanalysed using published data for cohorts of children in Saradidi (western Kenya). Infection risk was treated as binomially distributed, and measurement-error (Poisson and negative binomial) models were considered for the EIR. Models were fitted using Bayesian Markov chain Monte Carlo algorithms and model fit compared for models that assume either mass-action kinetics, facilitation, competition or saturation of the infection process with increasing EIR.</p> <p>Results</p> <p>The proportion of inocula that resulted in infection in Saradidi was inversely related to the measured intensity of challenge. Models of facilitation showed, therefore, a poor fit to the data. When sampling error in the EIR was neglected, either competition or saturation needed to be incorporated in the model in order to give a good fit. Negative binomial models for the error in exposure could achieve a comparable fit while incorporating the more parsimonious and biologically plausible mass action assumption. Models that assume negative binomial micro-heterogeneity predict lower incidence of infection at a given average exposure than do those assuming exposure to be uniform. The negative binomial model moreover provides an estimate of the variance of the within-cohort distribution of the EIR and hence of within cohort heterogeneity in exposure.</p> <p>Conclusion</p> <p>Apparent deviations from mass action kinetics in parasite transmission can arise from spatial and temporal heterogeneity in the inoculation rate, and from imprecision in its measurement. For parasites like <it>P. falciparum</it>, where there is no plausible biological rationale for deviations from mass action, this provides a strategy for estimating true levels of heterogeneity, since if mass-action is assumed, the within-population variance in exposure becomes identifiable in cohort studies relating infection to transmission intensity. Statistical analyses relating infection to exposure thus provide a valid general approach for estimating heterogeneity in transmission but only when they incorporate mass action kinetics and shrinkage estimates of exposure. Such analyses make it possible to include realistic levels of heterogeneity in dynamic models that predict the impact of control measures on transmission intensity.</p