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Field studies were conducted in 2016 and 2017 at Clinton, NC, to quantify the effects of season-long interference of large crabgrass [Digitaria sanguinalis (L.) Scop.] and Palmer amaranth (Amaranthus palmeri S. Watson) on ‘AG6536’ soybean [Glycine max (L.) Merr.]. Weed density treatments consisted of 0, 1, 2, 4, and 8 plants m−2 for A. palmeri and 0, 1, 2, 4, and 16 plants m−2 for D. sanguinalis with (interspecific interference) and without (intraspecific interference) soybean to determine the impacts on weed biomass, soybean biomass, and seed yield. Biomass per square meter increased with increasing weed density for both weed species with and without soybean present. Biomass per square meter of D. sanguinalis was 617% and 37% greater when grown without soybean than with soybean, for 1 and 16 plants m−2 respectively. Biomass per square meter of A. palmeri was 272% and 115% greater when grown without soybean than with soybean for 1 and 8 plants m−2, respectively. Biomass per plant for D. sanguinalis and A. palmeri grown without soybean was greatest at the 1 plant m−2 density. Biomass per plant of D. sanguinalis plants across measured densities was 33% to 83% greater when grown without soybean compared with biomass per plant when soybean was present for 1 and 16 plants m−2, respectively. Similarly, biomass per plant for A. palmeri was 56% to 74% greater when grown without soybean for 1 and 8 plants m−2, respectively. Biomass per plant of either weed species was not affected by weed density when grown with soybean due to interspecific competition with soybean. Yield loss for soybean grown with A. palmeri ranged from 14% to 37% for densities of 1 to 8 plants m−2, respectively, with a maximum yield loss estimate of 49%. Similarly, predicted loss for soybean grown with D. sanguinalis was 0 % to 37% for densities of 1 to 16 m−2 with a maximum yield loss estimate of 50%. Soybean biomass was not affected by weed species or density. Results from these studies indicate that A. palmeri is more competitive than D. sanguinalis at lower densities, but that similar yield loss can occur when densities greater than 4 plants m−2 of either weed are present.
What are the effects of wearable police cameras on perceptions of the police? In this study, we report causal estimates from a crossover randomized controlled trial in Uruguay on the effects of use of body-worn cameras by traffic police on the perceptions of legitimacy and satisfaction by drivers ticketed for traffic violations. We pay particular attention to the effects on procedural justice—that is, perceptions of the fairness of the interactions between officers and drivers—without neglecting other features of legitimacy (i.e., effectiveness, distributive justice, and lawfulness). With the exception of lawfulness, wearable surveillance apparatuses showed improvements across all dimensions of legitimacy compared to control conditions, with medium to large effect sizes. The overall satisfaction from the police-public interaction was significantly higher when officers used body-worn cameras. These findings suggest that wearable surveillance technology can lead to enhanced perceptions of legitimacy across multiple dimensions, not just increased efficiency, as well as the perceived overall quality of police-public interaction.
Current coverage of mental healthcare in low- and middle-income countries is very limited, not only in terms of access to services but also in terms of financial protection of individuals in need of care and treatment.
To identify the challenges, opportunities and strategies for more equitable and sustainable mental health financing in six sub-Saharan African and South Asian countries, namely Ethiopia, India, Nepal, Nigeria, South Africa and Uganda.
In the context of a mental health systems research project (Emerald), a multi-methods approach was implemented consisting of three steps: a quantitative and narrative assessment of each country's disease burden profile, health system and macro-fiscal situation; in-depth interviews with expert stakeholders; and a policy analysis of sustainable financing options.
Key challenges identified for sustainable mental health financing include the low level of funding accorded to mental health services, widespread inequalities in access and poverty, although opportunities exist in the form of new political interest in mental health and ongoing reforms to national insurance schemes. Inclusion of mental health within planned or nascent national health insurance schemes was identified as a key strategy for moving towards more equitable and sustainable mental health financing in all six countries.
Including mental health in ongoing national health insurance reforms represent the most important strategic opportunity in the six participating countries to secure enhanced service provision and financial protection for individuals and households affected by mental disorders and psychosocial disabilities.
Declaration of interest
D.C. is a staff member of the World Health Organization.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
Species distribution models (SDMs) are statistical tools used to develop continuous predictions of species occurrence. ‘Integrated SDMs’ (ISDMs) are an elaboration of this approach with potential advantages that allow for the dual use of opportunistically collected presence-only data and site-occupancy data from planned surveys. These models also account for survey bias and imperfect detection through the use of a hierarchical modelling framework that separately estimates the species–environment response and detection process. This is particularly helpful for conservation applications and predictions for rare species, where data are often limited and prediction errors may have significant management consequences. Despite this potential importance, ISDMs remain largely untested under a variety of scenarios. We performed an exploration of key modelling decisions and assumptions on an ISDM using the endangered Baird’s tapir (Tapirus bairdii) as a test species. We found that site area had the strongest effect on the magnitude of population estimates and underlying intensity surface and was driven by estimates of model intercepts. Selecting a site area that accounted for the individual movements of the species within an average home range led to population estimates that coincided with expert estimates. ISDMs that do not account for the individual movements of species will likely lead to less accurate estimates of species intensity (number of individuals per unit area) and thus overall population estimates. This bias could be severe and highly detrimental to conservation actions if uninformed ISDMs are used to estimate global populations of threatened and data-deficient species, particularly those that lack natural history and movement information. However, the ISDM was consistently the most accurate model compared to other approaches, which demonstrates the importance of this new modelling framework and the ability to combine opportunistic data with systematic survey data. Thus, we recommend researchers use ISDMs with conservative movement information when estimating population sizes of rare and data-deficient species. ISDMs could be improved by using a similar parameterization to spatial capture–recapture models that explicitly incorporate animal movement as a model parameter, which would further remove the need for spatial subsampling prior to implementation.
Field studies were conducted in 2016 and 2017 in Clinton, NC, to determine the interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri S. Watson) or large crabgrass [Digitaria sanguinalis (L.) Scop.] in ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Amaranthus palmeri and D. sanguinalis were established 1 d after sweetpotato transplanting and maintained season-long at 0, 1, 2, 4, 8 and 0, 1, 2, 4, 16 plants m−1 of row in the presence and absence of sweetpotato, respectively. Predicted yield loss for sweetpotato was 35% to 76% for D. sanguinalis at 1 to 16 plants m−1 of row and 50% to 79% for A. palmeri at 1 to 8 plants m−1 of row. Weed dry biomass per meter of row increased linearly with increasing weed density. Individual dry biomass of A. palmeri and D. sanguinalis was not affected by weed density when grown in the presence of sweetpotato. When grown without sweetpotato, individual weed dry biomass decreased 71% and 62% from 1 to 4 plants m−1 row for A. palmeri and D. sanguinalis, respectively. Individual weed dry biomass was not affected above 4 plants m−1 row to the highest densities of 8 and 16 plants m−1 row for A. palmeri and D. sanguinalis, respectively.
Whereas genetic susceptibility increases the risk for major depressive disorder (MDD), non-genetic protective factors may mitigate this risk. In a large-scale prospective study of US Army soldiers, we examined whether trait resilience and/or unit cohesion could protect against the onset of MDD following combat deployment, even in soldiers at high polygenic risk.
Data were analyzed from 3079 soldiers of European ancestry assessed before and after their deployment to Afghanistan. Incident MDD was defined as no MDD episode at pre-deployment, followed by a MDD episode following deployment. Polygenic risk scores were constructed from a large-scale genome-wide association study of major depression. We first examined the main effects of the MDD PRS and each protective factor on incident MDD. We then tested the effects of each protective factor on incident MDD across strata of polygenic risk.
Polygenic risk showed a dose–response relationship to depression, such that soldiers at high polygenic risk had greatest odds for incident MDD. Both unit cohesion and trait resilience were prospectively associated with reduced risk for incident MDD. Notably, the protective effect of unit cohesion persisted even in soldiers at highest polygenic risk.
Polygenic risk was associated with new-onset MDD in deployed soldiers. However, unit cohesion – an index of perceived support and morale – was protective against incident MDD even among those at highest genetic risk, and may represent a potent target for promoting resilience in vulnerable soldiers. Findings illustrate the value of combining genomic and environmental data in a prospective design to identify robust protective factors for mental health.
Little is known about the household economic costs associated with mental, neurological and substance use (MNS) disorders in low- and middle-income countries.
To assess the association between MNS disorders and household education, consumption, production, assets and financial coping strategies in Ethiopia, India, Nepal, Nigeria, South Africa and Uganda.
We conducted an exploratory cross-sectional household survey in one district in each country, comparing the economic circumstances of households with an MNS disorder (alcohol-use disorder, depression, epilepsy or psychosis) (n = 2339) and control households (n = 1982).
Despite some heterogeneity between MNS disorder groups and countries, households with a member with an MNS disorder had generally lower levels of adult education; lower housing standards, total household income, effective income and non-health consumption; less asset-based wealth; higher healthcare expenditure; and greater use of deleterious financial coping strategies.
Households living with a member who has an MNS disorder constitute an economically vulnerable group who are susceptible to chronic poverty and intergenerational poverty transmission.
Declaration of interest
D.C. is a staff member of the World Health Organization. The authors alone are responsible for the views expressed in this publication and they do not necessarily represent the decisions, policy or views of the World Health Organization.
Retrospective reports of lifetime experience with mental disorders greatly underestimate the actual experiences of disorder because recall error biases reporting of earlier life symptoms downward. This fundamental obstacle to accurate reporting has many adverse consequences for the study and treatment of mental disorders. Better tools for accurate retrospective reporting of mental disorder symptoms have the potential for broad scientific benefits.
We designed a life history calendar (LHC) to support this task, and randomized more than 1000 individuals to each arm of a retrospective diagnostic interview with and without the LHC. We also conducted a careful validation with the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition.
Results demonstrate that—just as with frequent measurement longitudinal studies—use of an LHC in retrospective measurement can more than double reports of lifetime experience of some mental disorders.
The LHC significantly improves retrospective reporting of mental disorders. This tool is practical for application in both large cross-sectional surveys of the general population and clinical intake of new patients.
Both double-crystal and triple-axis x-ray diffraction techniques have been used to study complex SiGe/Si structures. A novel method for measuring the nucleation activation energy of dislocations in strain relaxed SiGe/Si structures is presented to illustrate the usefulness of these techniques.
Evidence shows benefits of psychological treatments in low-resource countries, yet few government health systems include psychological services.
Evaluating the clinical value of adding psychological treatments, delivered by community-based counsellors, to primary care-based mental health services for depression and alcohol use disorder (AUD), as recommended by the Mental Health Gap Action Programme (mhGAP).
Two randomised controlled trials, separately for depression and AUD, were carried out. Participants were randomly allocated (1:1) to mental healthcare delivered by mhGAP-trained primary care workers (psychoeducation and psychotropic medicines when indicated), or the same services plus individual psychological treatments (Healthy Activity Program for depression and Counselling for Alcohol Problems). Primary outcomes were symptom severity, measured using the Patient Health Questionnaire – 9 item (PHQ-9) for depression and the Alcohol Use Disorder Identification Test for AUD, and functional impairment, measured using the World Health Organization Disability Assessment Schedule (WHODAS), at 12 months post-enrolment.
Participants with depression in the intervention arm (n = 60) had greater reduction in PHQ-9 and WHODAS scores compared with participants in the control (n = 60) (PHQ-9: M = −5.90, 95% CI −7.55 to −4.25, β = −3.68, 95% CI −5.68 to −1.67, P < 0.001, Cohen's d = 0.66; WHODAS: M = −12.21, 95% CI −19.58 to −4.84, β = −10.74, 95% CI −19.96 to −1.53, P= 0.022, Cohen's d = 0.42). For the AUD trial, no significant effect was found when comparing control (n = 80) and intervention participants (n = 82).
Adding a psychological treatment delivered by community-based counsellors increases treatment effects for depression compared with only mhGAP-based services by primary health workers 12 months post-treatment.
Watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] grafting is commonly used for management of diseases caused by soilborne pathogens; however, little research exists describing the effect of grafting on the weed-competitive ability of watermelon. Field experiments determined the response in yield, fruit number, and fruit quality of grafted and nongrafted watermelon exposed to increasing densities of Palmer amaranth (Amaranthus palmeri S. Watson). Grafting treatments included ‘Exclamation’ triploid (seedless) watermelon grafted on two interspecific hybrid squash rootstocks ‘Carnivor’ and ‘Kazako’, with nongrafted Exclamation as the control. Weed treatments included A. palmeri at densities of 1, 2, 3, and 4 A. palmeri plants per watermelon planting hole (0.76-m row) and a weed-free control. Increasing A. palmeri densities caused significant reductions (P <0.05) in marketable watermelon yield and marketable fruit number. Watermelon yield reduction was described by a rectangular hyperbola model, and 4 A. palmeri plants planting hole−1 reduced marketable yield 41%, 38%, and 65% for Exclamation, Carnivor, and Kazako, respectively. Neither grafting treatment nor A. palmeri density had a biologically meaningful effect on soluble solids content or on the incidence of hollow heart in watermelon fruit. Amaranthus palmeri seed and biomass production was similar across weed population densities, but seed number per female A. palmeri decreased according to a two-parameter exponential decay equation. Thus, increasing weed population densities resulted in increased intraspecific competition among A. palmeri plants. While grafting may offer benefits for disease resistance, no benefits regarding weed-competitive ability were observed, and a consistent yield penalty was associated with grafting, even in weed-free treatments.
For a positive integer k and a prime p ≡ 1 (mod k), there is a proper subgroup, R, of the multiplicative group (mod p) consisting of the kth power residues (mod p). A necessary and sufficient condition that an integer t be an element of R is that the congruence xk ≡ t (mod p) be solvable. The cosets, not R, formed with respect to R are called classes of kth power nonresidues, and form with R a cyclic group of order k. Let ρ be a primitive kth root of unity and let S be a class of non-residues that is a generator of this cyclic group. There is a kth power character X (mod p) such that
Field experiments determined the critical period for weed control (CPWC) in grafted and nongrafted watermelon [Citrullus lanatus (Thumb.) Matsum. & Nakai] grown in plasticulture. Transplant types included ‘Exclamation’ seedless watermelon as the nongrafted control as well as Exclamation grafted onto two interspecific hybrid squash (ISH) rootstocks, ‘Carnivor’ and ‘Kazako’. To simulate weed emergence throughout the season, establishment treatments (EST) consisted of two seedlings each of common purslane (Portulaca oleracea L.), large crabgrass [Digitaria sanguinalis (L.) Scop.], and yellow nutsedge (Cyperus esculentus L.) transplanted in a 15 by 15 cm square centered on watermelon plants at 0, 2, 3, 4, and 6 wk after watermelon transplanting (WATr) and remained until the final watermelon harvest at 11 WATr. To simulate weed control at different times in the season, removal treatments (REM) consisted of two seedlings of the same weed species transplanted in a 15 by 15 cm square centered on watermelon plants on the same day of watermelon transplanting and allowed to remain until 2, 3, 4, 6, and 11 WATr, at which time they were removed. Season-long weedy and weed-free controls were included for both EST and REM studies in both years. For all transplant types, aboveground biomass of weeds decreased as weed establishment was delayed and increased as weed removal was delayed. The predicted CPWC for nongrafted Exclamation and Carnivor required only a single weed removal between 2.3 and 2.5 WATr and 1.9 and 2.6 WATr, respectively, while predicted CPWC for Kazako rootstock occurred from 0.3 to 2.6 WATr. Our study results suggest that weed control for this mixed population of weeds would be similar between nongrafted Exclamation and Exclamation grafted onto Carnivor. But the observed CPWC of Exclamation grafted onto Kazako suggests that CPWC may vary with specific rootstock–scion combinations.
As reported from studies conducted in Nepal, between 15% and 57% of adults had ever consumed alcohol and between 1.5% and 25% of adults have alcohol use disorders (AUD). Few studies in Nepal have identified the correlates of consumption or described the help-seeking patterns and stigma among those affected with AUD.
Interviewers administered the Alcohol Use Disorders Identification Test (AUDIT) as part of population-based surveys of adults in Chitwan District between 2013 and 2017. We conducted a secondary analysis to identify sociodemographic and health-related correlates of recent alcohol consumption using the χ2 test, to identify correlates of total AUDIT scores among men who drink using negative binomial regression, and to describe the treatment-seeking and stigma beliefs of men with AUD.
Over half (53.7%, 95% CI 50.4–57.0) of men (n = 1130) recently consumed alcohol, and there were associations between being a drinker with age, religion, caste, education, occupation and tobacco use. Nearly one in four (23.8%, 95% CI 20.2–27.8%) male drinkers screened positive for AUD, and AUDIT scores were associated with age, caste, marital status, occupation, tobacco use, depression, functional status and suicidal ideation. Few (13.3%, 95% CI 11.7–15.0) women (n = 2352) recently consumed alcohol, and 5.3% (95% CI 3.0–9.1) of female drinkers screened positive for AUD. Among AUDIT-positive men, 38% spoke to another person about their problems and 80% had internalized stigma.
This study revealed that nearly one in four men who drink likely have AUD. Higher AUDIT scores were associated with depression, suicidality, dysfunctionality and internalized stigma.