104 research outputs found
Valuing agricultural externalities in Canterbury rivers and streams
Water quality and quantity concerns in Canterbury are intrinsically related to agriculture. Monetary values for impacts on streams and rivers is lacking in policy debate. This paper employs choice modelling to estimate values of three impacts on rivers and streams in Canterbury associated with agriculture: health risks of E coli from animal waste, ecological effects of excess nutrients, and low-flow impacts of irrigation. This study provides a valuation of outcomes for public policy implemented in Canterbury such as The Dairy and Clean Streams Accord, Living Streams, and The Restorative Programme for Lowland Streams.non-market-valuation, choice experiment, agricultural externalities, New Zealand, Agricultural and Food Policy, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Health Economics and Policy,
Nonmarket valuation of water quality: Addressing spatially heterogeneous preferences using GIS and a random parameter logit model
The spatial distribution of agri-environmental policy benefits has important implications for the efficient allocation of management effort. The practical convenience of relying on sample mean values of individual benefits for aggregation can come at the cost of biased aggregate estimates. The main objective of this paper is to test spatial hypotheses regarding respondents' local water quality and quantity, and their willingness-to-pay for improvements in water quality attributes. This paper combines choice experiment and spatially related water quality data via a Geographical Information System (GIS) to develop a method that evaluates the influence of respondents' local water quality on willingness-to-pay for river and stream conservation programmes in Canterbury, New Zealand. Results showed that those respondents who live in the vicinity of low quality waterways are willing to pay more for improvements relative to those who live near to high quality waterways. The study also found that disregarding the influence of respondents' local water quality data has a significant impact on the magnitude of welfare estimates and causes substantial underestimation of aggregated benefits
Developmental Resting State Functional Connectivity for Clinicians
Resting state functional magnetic imaging (fMRI) is a novel means to examine functional brain networks. It allows investigators to identify functional networks defined by distinct, spontaneous signal fluctuations. Resting state functional connectivity (RSFC) studies examining child and adolescent psychiatric disorders are being published with increasing frequency, despite concerns about the impact of motion on findings. Here we review important RSFC findings on typical brain development and recent publications of child and adolescent psychiatric disorders. We close with a summary of the major findings and current strengths and limitations of RSFC studies
Depressive and anxiety disorders and antidepressant prescriptions among insured children and young adults with congenital adrenal hyperplasia in the United States
BackgroundDysfunction in the hypothalamic-pituitary-adrenal axis has been associated with depressive and anxiety disorders. Little is known about the risk for these disorders among individuals with congenital adrenal hyperplasia (CAH), a form of primary adrenal insufficiency.ObjectiveWe investigated the prevalence of depressive and anxiety disorders and antidepressant prescriptions in two large healthcare databases of insured children, adolescents, and young adults with CAH in the United States.MethodsWe conducted a retrospective cohort study using administrative data from October 2015 through December 2019 for individuals aged 4–25 years enrolled in employer-sponsored or Medicaid health plans.ResultsAdjusting for age, the prevalence of depressive disorders [adjusted prevalence ratio (aPR) = 1.7, 95% confidence interval (CI): 1.4-2.0, p<0.001], anxiety disorders [aPR = 1.7, 95% CI: 1.4-1.9, p<0.001], and filled antidepressant prescriptions [aPR = 1.7, 95% CI: 1.4-2.0, p<0.001] was higher among privately insured youth with CAH as compared to their non-CAH peers. Prevalence estimates were also higher among publicly insured youth with CAH for depressive disorders [aPR = 2.3, 95% CI: 1.9-2.9, p<0.001], anxiety disorders [aPR = 2.0, 95% CI: 1.6-2.5, p<0.001], and filled antidepressant prescriptions [aPR = 2.5, 95% CI: 1.9-3.1, p<0.001] as compared to their non-CAH peers.ConclusionsThe elevated prevalence of depressive and anxiety disorders and antidepressant prescriptions among youth with CAH suggests that screening for symptoms of depression and anxiety among this population might be warranted
The Collective Submitted Works from Honors 2030
Students in the Honors 2030, Inquiries in the Social and Behavioral Sciences course each participated in the URS 2020 as their final project for the course. Dr. Wilson worked with each student as a faculty mentor to create, draft, edit, approve and publish each of the final posters and papers submitted to the 2020 URS for the course
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Correction:Brain structural abnormalities in obesity: relation to age, genetic risk, and common psychiatric disorders: Evidence through univariate and multivariate mega-analysis including 6420 participants from the ENIGMA MDD working group (Molecular Psychiatry, (2020), 10.1038/s41380-020-0774-9)
Regional brain volumes and antidepressant treatment resistance in major depressive disorder
Major depressive disorder (MDD) is a heritable and highly debilitating condition with
antidepressants, first-line treatment, demonstrating low to modest response rates. No
current biological mechanism substantially explains MDD but both neurostructural
and neurochemical pathways have been suggested. Further explication of these may
aid in identifying subgroups of MDD that are better defined by their aetiology.
Specifically, genetic stratification provides an array of tools to do this, including the
intermediate phenotype approach which was applied in this thesis. This thesis explores
genetic overlap with regional brain volume and MDD and the genetic and non-genetic
components of antidepressant response.
The first study utilised the most recent published data from ENIGMA (Enhancing
Neuroimaging Genetics through Meta-analysis) Consortium’s genome-wide
association study (GWAS) of regional brain volume to examine shared genetic
architecture between seven subcortical brain volumes and intracranial volume (ICV)
and MDD. This was explored using linkage disequilibrium score regression (LDSC),
polygenic risk scoring (PRS) techniques, Mendelian randomisation (MR) analysis and
BUHMBOX (Breaking Up Heterogeneous Mixture Based On Cross-locus
correlations). Results indicated that hippocampal volume was positively genetically
correlated with MDD (rg= 0.46, P= 0.02), although this did not survive multiple
comparison testing. Additionally, there was evidence for genetic subgrouping in
Generation Scotland: Scottish Family Health Study (GS:SFHS) MDD cases
(P=0.00281), however, this was not replicated in two other independent samples. This
study does not support a shared architecture for regional brain volumes and MDD,
however, provided some evidence that hippocampal volume and MDD may share
genetic architecture in a subgroup of individuals, albeit the genetic correlation did not
survive multiple testing correction and genetic subgroup heterogeneity was not
replicated.
To explore antidepressant treatment resistance, the second study utilised prescription
data in (GS:SFHS) to define a measure of (a) treatment resistance (TR) and (b) stages
of resistance (SR) by inferring antidepressant switching as non-response. GWAS were
conducted separately for TR in GS:SFHS and the GENDEP (Genome-based
Therapeutic Drugs for Depression) study and then meta-analysed (meta-analysis
n=4,213, cases=358). For SR, a GWAS on GS:SFHS only was performed (n=3,452).
Additionally, gene-set enrichment, polygenic risk scoring (PRS) and genetic
correlation analysis were conducted. No significant locus, gene or gene-set was
associated with TR or SR, however power analysis indicated that this analysis was
underpowered. Pedigree-based correlations identified genetic overlap with
psychological distress, schizotypy and mood disorder traits.
Finally, the role of neuroticism, psychological resilience and coping styles in
antidepressant resistance was investigated. Univariate, moderation and mediation
models were applied using logistic regression and structural equation modelling
techniques. In univariate models, neuroticism and emotion-orientated coping
demonstrated significant negative association with antidepressant resistance, whereas
resilience, task-orientated and avoidance-orientated coping demonstrated significant
positive association. No moderation of the association between neuroticism and TR
was detected and no mediating effect of coping styles was found. However, resilience
was found to partially mediate the association between neuroticism and TR.
Whilst the first study does not indicate a genetic overlap between regional brain
volumes and MDD, it demonstrates the utility of the intermediate approach in complex
disease. Antidepressant resistance was associated with neuroticism both genetically
and phenotypically, indicating its role as an intermediate phenotype. Nonetheless,
larger sample sizes are needed to adequately address the components of antidepressant
resistance. Further work in antidepressant non-response may help to identify biological
mechanisms responsible in MDD pathology and help stratify individuals into more
tractable groups
DenseNet and Support Vector Machine classifications of major depressive disorder using vertex-wise cortical features
Major depressive disorder (MDD) is a complex psychiatric disorder that
affects the lives of hundreds of millions of individuals around the globe. Even
today, researchers debate if morphological alterations in the brain are linked
to MDD, likely due to the heterogeneity of this disorder. The application of
deep learning tools to neuroimaging data, capable of capturing complex
non-linear patterns, has the potential to provide diagnostic and predictive
biomarkers for MDD. However, previous attempts to demarcate MDD patients and
healthy controls (HC) based on segmented cortical features via linear machine
learning approaches have reported low accuracies. In this study, we used
globally representative data from the ENIGMA-MDD working group containing an
extensive sample of people with MDD (N=2,772) and HC (N=4,240), which allows a
comprehensive analysis with generalizable results. Based on the hypothesis that
integration of vertex-wise cortical features can improve classification
performance, we evaluated the classification of a DenseNet and a Support Vector
Machine (SVM), with the expectation that the former would outperform the
latter. As we analyzed a multi-site sample, we additionally applied the ComBat
harmonization tool to remove potential nuisance effects of site. We found that
both classifiers exhibited close to chance performance (balanced accuracy
DenseNet: 51%; SVM: 53%), when estimated on unseen sites. Slightly higher
classification performance (balanced accuracy DenseNet: 58%; SVM: 55%) was
found when the cross-validation folds contained subjects from all sites,
indicating site effect. In conclusion, the integration of vertex-wise
morphometric features and the use of the non-linear classifier did not lead to
the differentiability between MDD and HC. Our results support the notion that
MDD classification on this combination of features and classifiers is
unfeasible
- …