Evaluation of the validity and utility of a transdiagnostic psychosis dimension encompassing schizophrenia and bipolar disorder

BACKGROUND

In recent years, the Kraepelinian dichotomy has been challenged in light of evidence on shared genetic and environmental factors for schizophrenia and bipolar disorder, but empirical efforts to identify a transdiagnostic phenotype of psychosis remain remarkably limited.

AIMS

To investigate whether schizophrenia spectrum and bipolar disorder lie on a transdiagnostic spectrum with overlapping non-affective and affective psychotic symptoms.

METHOD

Multidimensional item-response modelling was conducted on symptom ratings of the OPerational CRITeria (OPCRIT) system in 1168 patients with schizophrenia spectrum and bipolar disorder.

RESULTS

A bifactor model with one general, transdiagnostic psychosis dimension underlying affective and non-affective psychotic symptoms and five specific dimensions of positive, negative, disorganised, manic and depressive symptoms provided the best model fit and diagnostic utility for categorical classification.

CONCLUSIONS

Our findings provide support for including dimensional approaches into classification systems and a directly measurable clinical phenotype for cross-disorder investigations into shared genetic and environmental factors of psychosis.

The Emotional Eating Scale adapted for children and adolescents: Factorial invariance across adolescent males and females

OBJECTIVE

The purpose of the present study was to assess factorial invariance of the Emotional Eating Scale (EES) across a sample of adolescent males and females.

METHOD

Two-hundred-twenty-six middle school students (mean age=13.19years; SD=1.00) completed the EES adapted for children and adolescents and a brief demographic survey. Approximately 40% of the sample were males. An item-level multi-group confirmatory factor analysis was performed specifying a bi-factor model that mapped onto the EES' four scores.

RESULTS

We found that the EES was partially invariant across sex in the current study's sample. The instrument appeared to measure the same constructs in both groups, except for the two items: worried and bored.

CONCLUSIONS

Our findings suggest that overall the EES items measure their intended constructs in both male and female adolescents, but caution should be used when interpreting scores that include the worried and bored items. These two item may have be measuring their constructs differently in adolescent females and males.

Influence of selected anti-cancer drugs on the induction of DNA double-strand breaks and changes in gene expression in human hepatoma HepG2 cells

In chemotherapy, various anti-cancer drugs with different mechanisms of action are used and may represent different risk of undesirable delayed side effects in treated patients as well as in occupationally exposed populations. The aim of the present study was to evaluate genotoxic potential of four widely used anti-cancer drugs with different mechanisms of action: 5-fluorouracil (5-FU), cisplatin (CDDP) and etoposide (ET) that cause cell death by targeting DNA function and imatinib mesylate (IM) that inhibits targeted protein kinases in cancer cells in an experimental model with human hepatoma HepG2 cells. After 24 h of exposure all four anti-cancer drugs at non-cytotoxic concentrations induced significant increase in formation of DNA double strand breaks (DSBs), with IM being the least effective. The analysis of the changes in the expression of genes involved in the response to DNA damage (CDKN1A, GADD45A, MDM2), apoptosis (BAX, BCL2) and oncogenesis (MYC, JUN) showed that 5-FU, CDDP and ET upregulated the genes involved in DNA damage response, while the anti-apoptotic gene BCL2 and oncogene MYC were downregulated. On the contrary, IM did not change the mRNA level of the studied genes, showing different mechanism of action that probably does not involve direct interaction with DNA processing. Genotoxic effects of the tested anti-cancer drugs were observed at their therapeutic concentrations that may consequently lead to increased risk for development of delayed adverse effects in patients. In addition, considering the genotoxic mechanism of action of 5-FU, CDDP and ET an increased risk can also not be excluded in occupationally exposed populations. The results also indicate that exposure to 5-FU, CDDP and ET represent a higher risk for delayed effects such as cancer, reproductive effects and heritable disease than exposure to IM.

Clonal growth buffers the effect of grazing management on the population growth rate of a perennial grassland herb

Grazing is an important management action to conserve biodiversity in semi-natural grasslands but it is important to understand how grazing influences the life-history components and population dynamics of plant species. In this study, we analysed effects of grazing intensity and abandonment on population dynamics of the semi-natural grassland species Knautia arvensis which is an important nectar source for pollinating species and an indicator of biodiversity in agricultural landscapes. We recorded life-history stage, survival, establishment of seedlings and ramets, number of inflorescences and grazing marks on permanently marked individuals in eight populations in mid-Norway for three consecutive years. Matrix modelling was used to estimate population growth rates and elasticities, and life Table response experiments (LTREs) were used to assess the contribution of different life-history components to the observed variation in population growth rates between different management treatments. Generalized linear mixed effects models (GLMMs) were used to investigate the effect of management on vital rates and number of inflorescences as well as damage to K. arvensis individuals. Populations in abandoned grasslands had more inflorescences, a lower proportion of seedlings and a higher proportion of flowering ramets compared to populations in grasslands under high grazing intensity. There were no differences in population growth rates between different grazing intensities. Fecundity however, contributed more to the growth rate in grazed grasslands compared to abandoned grasslands where clonal regeneration contributed the most. Survival of non-flowering rosettes made the largest impact to overall growth rates. Our results indicate that a long life-span and clonal growth buffer the effect of environmental change in abandoned grasslands and that there is a trade-off between fertility and clonal regeneration in K. arvensis populations.

Work-Family Trajectories and the Higher Cardiovascular Risk of American Women Relative to Women in 13 European Countries

OBJECTIVES

To investigate whether less-healthy work-family life histories contribute to the higher cardiovascular disease prevalence in older American compared with European women.

METHODS

We used sequence analysis to identify distinct work-family typologies for women born between 1935 and 1956 in the United States and 13 European countries. Data came from the US Health and Retirement Study (1992-2006) and the Survey of Health, Aging, and Retirement in Europe (2004-2009).

RESULTS

Work-family typologies were similarly distributed in the United States and Europe. Being a lone working mother predicted a higher risk of heart disease, stroke, and smoking among American women, and smoking for European women. Lone working motherhood was more common and had a marginally stronger association with stroke in the United States than in Europe. Simulations indicated that the higher stroke risk among American women would only be marginally reduced if American women had experienced the same work-family trajectories as European women.

CONCLUSIONS

Combining work and lone motherhood was more common in the United States, but differences in work-family trajectories explained only a small fraction of the higher cardiovascular risk of American relative to European women.

The comparative efficacy and safety of cholinesterase inhibitors in patients with mild-to-moderate Alzheimer's disease: a Bayesian network meta-analysis

BACKGROUND

Comparative evidence for efficacy and safety of second-generation cholinesterase inhibitors (ChEIs) is still sparse.

OBJECTIVES

The purpose of this research is to compare three ChEIs, donepezil, galantamine and rivastigmine, in patients with mild-to-moderate Alzheimer's disease (AD).

METHODS

We conducted a systematic review for published articles and included randomised, double-blind, placebo-controlled trials and head-to-head randomised trials evaluating the efficacy and safety of ChEIs in patients with AD. We examined Alzheimer's Disease Assessment Scale, cognitive subscale (ADAS-Cog), Neuropsychiatric Inventory (NPI), Clinician's Interview-Based Impression of Change plus caregiver's input (CIBIC+) and Clinical Global Impression of Change (CGIC) as efficacy endpoints. Withdrawals due to adverse events and number of patients experiencing nausea, vomiting, diarrhoea and dizziness were examined as safety profiles. Network meta-analyses were sequentially performed for efficacy and safety outcomes based on drug/dose treatment conditions.

RESULTS

Among the 21 trials included, network meta-analysis showed that all treatments were significantly more efficacious than placebo in cognition measured by ADAS-Cog. All treatments except galantamine were significantly more efficacious than placebo in global change in CIBIC+ or CGIC. Across all conditions, no significant efficacy was observed in neuropsychiatric symptoms measured by NPI. Derived hierarchies in the efficacy of treatment conditions were variables across efficacy and safety.

CONCLUSIONS

Our analysis is the first attempt to incorporate available direct and indirect evidence. The results suggest that ChEIs should have significant efficacy for cognition and global change assessment, but the efficacy on neuropsychiatric symptoms is questionable in patients with mild-to-moderate AD.

Generalizing the Network Scale-Up Method: A New Estimator for the Size of Hidden Populations

The network scale-up method enables researchers to estimate the size of hidden populations, such as drug injectors and sex workers, using sampled social network data. The basic scale-up estimator offers advantages over other size estimation techniques, but it depends on problematic modeling assumptions. We propose a new generalized scale-up estimator that can be used in settings with non-random social mixing and imperfect awareness about membership in the hidden population. Further, the new estimator can be used when data are collected via complex sample designs and from incomplete sampling frames. However, the generalized scale-up estimator also requires data from two samples: one from the frame population and one from the hidden population. In some situations these data from the hidden population can be collected by adding a small number of questions to already planned studies. For other situations, we develop interpretable adjustment factors that can be applied to the basic scale-up estimator. We conclude with practical recommendations for the design and analysis of future studies.

Reflections of the social environment in chimpanzee memory: applying rational analysis beyond humans

In cognitive science, the rational analysis framework allows modelling of how physical and social environments impose information-processing demands onto cognitive systems. In humans, for example, past social contact among individuals predicts their future contact with linear and power functions. These features of the human environment constrain the optimal way to remember information and probably shape how memory records are retained and retrieved. We offer a primer on how biologists can apply rational analysis to study animal behaviour. Using chimpanzees (Pan troglodytes) as a case study, we modelled 19 years of observational data on their social contact patterns. Much like humans, the frequency of past encounters in chimpanzees linearly predicted future encounters, and the recency of past encounters predicted future encounters with a power function. Consistent with the rational analyses carried out for human memory, these findings suggest that chimpanzee memory performance should reflect those environmental regularities. In re-analysing existing chimpanzee memory data, we found that chimpanzee memory patterns mirrored their social contact patterns. Our findings hint that human and chimpanzee memory systems may have evolved to solve similar information-processing problems. Overall, rational analysis offers novel theoretical and methodological avenues for the comparative study of cognition.

Dynamic cerebral autoregulation in young athletes following concussion

The purpose of this study was to examine cerebral autoregulation (CA) in young athletes experiencing concussion. The subjects were monitored and repeatedly tested 72 hours, 2 weeks and 1 month post-injury. Mean arterial blood pressure (MABP), end-tidal partial pressure of carbon dioxide (PETCO2) and cerebral blood flow velocity (CBFV) in the middle and posterior cerebral arteries were monitored during mental activation paradigms. In order to characterize CA we employed autoregressive models with exogenous inputs (ARX) and impulse response models based on the Laguerre expansion technique (LET). By extracting gain and phase estimates from the obtained models we were able to detect disruptions in CA 72 hours following concussion and a slow recovery within a time period of one month.

Drinking Water Sodium and Elevated Blood Pressure of Healthy Pregnant Women in Salinity-Affected Coastal Areas

Coastal areas in Southeast Asia are experiencing high sodium concentrations in drinking water sources that are commonly consumed by local populations. Salinity problems caused by episodic cyclones and subsequent seawater inundations are likely (partly) related to climate change and further exacerbated by changes in upstream river flow and local land-use activities. Dietary (food) sodium plays an important role in the global burden of hypertensive disease. It remains unknown, however, if sodium in drinking water—rather than food—has similar effects on blood pressure and disease risk. In this study, we examined the effect of drinking water sodium on blood pressure of pregnant women: increases in blood pressure in this group could severely affect maternal and fetal health. Data on blood pressure, drinking water source, and personal, lifestyle, and environmental confounders was obtained from 701 normotensive pregnant women residing in coastal Bangladesh. Generalized linear mixed regression models were used to investigate association of systolic and diastolic blood pressure of these—otherwise healthy—women with their water source. After adjustment for confounders, drinkers of tube well and pond water (high saline sources) were found to have significantly higher average systolic (+4.85 and +3.62 mm Hg) and diastolic (+2.30 and +1.72 mm Hg) blood pressures than rainwater drinkers. Drinking water salinity problems are expected to exacerbate in the future, putting millions of coastal people—including pregnant women—at increased risk of hypertension and associated diseases. There is an urgent need to further explore the health risks associated to this understudied environmental health problem and feasibility of possible adaptation strategies.

Using empirical models of species colonization under multiple threatening processes to identify complementary threat-mitigation strategies

Approaches to prioritize conservation actions are gaining popularity. However, limited empirical evidence exists on which species might benefit most from threat mitigation and on what combination of threats, if mitigated simultaneously, would result in the best outcomes for biodiversity. We devised a way to prioritize threat mitigation at a regional scale with empirical evidence based on predicted changes to population dynamics-information that is lacking in most threat-management prioritization frameworks that rely on expert elicitation. We used dynamic occupancy models to investigate the effects of multiple threats (tree cover, grazing, and presence of an hyperaggressive competitor, the Noisy Miner (Manorina melanocephala) on bird-population dynamics in an endangered woodland community in southeastern Australia. The 3 threatening processes had different effects on different species. We used predicted patch-colonization probabilities to estimate the benefit to each species of removing one or more threats. We then determined the complementary set of threat-mitigation strategies that maximized colonization of all species while ensuring that redundant actions with little benefit were avoided. The single action that resulted in the highest colonization was increasing tree cover, which increased patch colonization by 5% and 11% on average across all species and for declining species, respectively. Combining Noisy Miner control with increasing tree cover increased species colonization by 10% and 19% on average for all species and for declining species respectively, and was a higher priority than changing grazing regimes. Guidance for prioritizing threat mitigation is critical in the face of cumulative threatening processes. By incorporating population dynamics in prioritization of threat management, our approach helps ensure funding is not wasted on ineffective management programs that target the wrong threats or species.

GPS tracking of non-breeding ravens reveals the importance of anthropogenic food sources during their dispersal in the Eastern Alps

In many songbirds, the space use of breeders is well studied but poorly understood for non-breeders. In common ravens, some studies of non-breeders indicate high vagrancy with large individual differences in home range size, whereas others show that up to 40% of marked non-breeders can be regularly observed at the same anthropogenic food source over months to years. The aim of this study was to provide new insights on ravens' behavior during dispersal in the Eastern Alps. We deployed Global Positioning System (GPS) loggers on 10 individuals to gather accurate spatial and temporal information on their movements to quantify: 1) the dimension of the birds' space use (home range size with seasonal effects and daily/long-term travel distances), 2) how long they stayed in a dispersal stage of wandering as opposed to settling temporarily, and 3) their destination of movements. We recorded movements of up to 40 km per hour, more than 160 km within 1 day and more than 11,000 km within 20 months, indicating high vagrancy. Switching frequently between temporarily settling and travelling large distances in short time intervals leads to extensive home ranges, which also explains and combines the different findings in the literature. The destinations are rich anthropogenic food sources, where the birds spent on average 75% of their time. We discuss how ravens may find these "feeding hot spots" and which factors may influence their decision to stay/leave a site. The strong dependence on anthropogenic resources found in this population may have implications for site management and conservation issues.

Impact of Mucinous Histology on the Prognosis of Stage I-III Adenocarcinomas of the Appendix: a Population-Based, Propensity Score-Matched Analysis

BACKGROUND

Whereas the poor prognosis of signet ring cell adenocarcinomas of the appendix is well known, the significance of mucinous histology remains unclear. The aim of this population-based study was to evaluate if mucinous histology is an independent prognostic factor in appendiceal adenocarcinomas.

METHODS

Patients with stage I-III adenocarcinoma of the appendix who underwent surgery between 2004 and 2012 were identified in the Surveillance, Epidemiology, and End Results database. Overall survival (OS) and cancer-specific survival (CSS) were assessed using risk-adjusted Cox proportional hazards regression models and propensity score methods.

RESULTS

Overall, 980 patients with appendix cancer were included, of which 449 (45.8 %) had a mucinous histology. In an unadjusted analysis, the 5-year OS and CSS in patients with a mucinous adenocarcinoma (MC) was 76.8 % (95 % confidence interval (95 %CI): 72.1-81.7 %) and 81.0 % (95 %CI: 76.6-85.6 %), respectively, compared with 70.0 % (95 %CI: 65.1-75.3 %) and 76.2 % (95 %CI: 71.5-81.2 %) in patients with non-mucinous adenocarcinoma (NMC) (P = 0.082 and P = 0.368). In multivariable analysis, no impact on survival was observed for OS (HR = 1.22, 95 %CI: 0.89-1.68, P = 0.208) and CSS (HR = 1.21, 95 %CI: 0.84-1.74, P = 0.296). After propensity score matching, nearly identical survival rates were observed (OS: HR = 1.03, 95 %CI: 0.71-1.49, P = 0.881 and CSS: HR = 1.05, 95 %CI: 0.70-1.59, P = 0.803).

CONCLUSIONS

The present population-based, propensity score matched analysis shows that mucinous histology does not affect survival in stage I-III appendiceal adenocarcinoma patients. Therefore, the same treatment strategies can be applied for patients with NMC and MC of the appendix.

Depression and anxiety in patients with Inflammatory Bowel Disease: A systematic review

OBJECTIVE

An increasing number of studies have been conducted to look at anxiety and depression in IBD; however, there is no clear consensus on the prevalence of anxiety and depression in this population. The objective of this systematic review was to compile the existing data on the prevalence of all mood and anxiety disorders in Inflammatory Bowel Disease patients.

METHODS

A series of comprehensive literature searches of Medline, Cochrane Library, PsycINFO, CINAHL, Embase, AMED, and ProQuest Dissertations were performed through March 2014. Inclusion criteria included peer-reviewed, published scientific articles that reported a measurement of mood or anxiety among IBD patients. Only studies with adults (≥18years old) and with more than 10 patients were included. Methodological quality was assessed for all included studies.

RESULTS

171 articles were identified with a total of 158,371 participants. Pooled prevalence estimate for anxiety disorders was 20.5% [4.9%, 36.5%] and 35.1% [30.5, 39.7%] for symptoms of anxiety. IBD patients in active disease had higher prevalence of anxiety of 75.6% [65.5%, 85.7%] compared to disease remission. Pooled prevalence of depression disorders was 15.2% [9.9%, 20.5%] and was 21.6% [18.7%, 24.3%] for symptoms of depression. The prevalence of depressive symptoms was higher in Crohn's disease (25.3% [20.7%, 30.0%]) compared to UC, and higher with active disease (40.7% [31.1%, 50.3%]) compared to IBD patients in remission.

CONCLUSION

Results from this systematic review indicate that patients with IBD have about a 20% prevalence rate of anxiety and a 15% prevalence rate of depression.

Social cognition in schizophrenia in comparison to bipolar disorder: A meta-analysis

OBJECTIVE

Cognitive dysfunction is a common characteristic of both schizophrenia and bipolar disorder (BP). While these deficits are more severe in schizophrenia, there is a significant overlap between conditions. However, it was hypothesized that social cognitive deficits might be more specific to schizophrenia.

METHODS

We conducted a meta-analysis of studies comparing facial emotion recognition and theory of mind (ToM) abilities in schizophrenia and BP. 26 studies comparing 1301 patients with schizophrenia and 1075 with BP were included.

RESULTS

Schizophrenia patients significantly underperformed compared with BP patients in both facial emotion recognition (d=0.39) and ToM (d=0.57). Neurocognitive deficits significantly contributed to schizophrenia-BP group differences for ToM. However, between-group differences for social cognition were not statistically more severe than neurocognition.

CONCLUSION

Social cognitive impairment is more severe in schizophrenia in comparison to BP. However, between-group differences are modest and are comparable to other neurocognitive differences between schizophrenia and BP. There is significant overlap in social cognitive performance deficits observed in both schizophrenia and BP.

Bidirectional prefrontal-hippocampal interactions support context-guided memory

We compared the dynamics of hippocampal and prefrontal interactions in rats as they used spatial contexts to guide the retrieval of object memories. Functional connectivity analysis indicated a flow of contextual information from the hippocampus to prefrontal cortex upon the rat's entry into the spatial context. Conversely, upon the onset of object sampling, the direction of information flow reversed, consistent with prefrontal control over the retrieval of context-appropriate hippocampal memory representations.

Can survival analyses detect hunting pressure in a highly connected species? Lessons from straw-coloured fruit bats

Animal behaviour, social structure and population dynamics affect community structure, interspecific interactions, and a species' resilience to harvesting. Building on new life history information for the straw-coloured fruit bat (Eidolon helvum) from multiple localities across Africa, we used survival analyses based on tooth-cementum annuli data to test alternative hypotheses relating to hunting pressure, demography and population connectivity. The estimated annual survival probability across Africa was high (≥ 0.64), but was greatest in colonies with the highest proportion of males. This difference in sex survival, along with age and sex capture biases and out-of-phase breeding across the species' distribution, leads us to hypothesize that E. helvum has a complex social structure. We found no evidence for additive mortality in heavily hunted populations, with most colonies having high survival with constant risk of mortality despite different hunting pressure. Given E. helvum's slow life history strategy, similar survival patterns and rate among colonies suggest that local movement and regional migration may compensate for local excess hunting, but these were also not clearly detected. Our study suggests that spatio-temporal data are necessary to appropriately assess the population dynamics and conservation status of this and other species with similar traits.

Best (but oft-forgotten) practices: propensity score methods in clinical nutrition research

In observational studies, treatment assignment is a nonrandom process and treatment groups may not be comparable in their baseline characteristics, a phenomenon known as confounding. Propensity score (PS) methods can be used to achieve comparability of treated and nontreated groups in terms of their observed covariates and, as such, control for confounding in estimating treatment effects. In this article, we provide a step-by-step guidance on how to use PS methods. For illustrative purposes, we used simulated data based on an observational study of the relation between oral nutritional supplementation and hospital length of stay. We focused on the key aspects of PS analysis, including covariate selection, PS estimation, covariate balance assessment, treatment effect estimation, and reporting. PS matching, stratification, covariate adjustment, and weighting are discussed. R codes and example data are provided to show the different steps in a PS analysis.

What Are We Looking for in Computer-Based Learning Interventions in Medical Education? A Systematic Review

Background

Computer-based learning (CBL) has been widely used in medical education, and reports regarding its usage and effectiveness have ranged broadly. Most work has been done on the effectiveness of CBL approaches versus traditional methods, and little has been done on the comparative effects of CBL versus CBL methodologies. These findings urged other authors to recommend such studies in hopes of improving knowledge about which CBL methods work best in which settings.

Objective

In this systematic review, we aimed to characterize recent studies of the development of software platforms and interventions in medical education, search for common points among studies, and assess whether recommendations for CBL research are being taken into consideration.

Methods

We conducted a systematic review of the literature published from 2003 through 2013. We included studies written in English, specifically in medical education, regarding either the development of instructional software or interventions using instructional software, during training or practice, that reported learner attitudes, satisfaction, knowledge, skills, or software usage. We conducted 2 latent class analyses to group articles according to platform features and intervention characteristics. In addition, we analyzed references and citations for abstracted articles.

Results

We analyzed 251 articles. The number of publications rose over time, and they encompassed most medical disciplines, learning settings, and training levels, totaling 25 different platforms specifically for medical education. We uncovered 4 latent classes for educational software, characteristically making use of multimedia (115/251, 45.8%), text (64/251, 25.5%), Web conferencing (54/251, 21.5%), and instructional design principles (18/251, 7.2%). We found 3 classes for intervention outcomes: knowledge and attitudes (175/212, 82.6%), knowledge, attitudes, and skills (11.8%), and online activity (12/212, 5.7%). About a quarter of the articles (58/227, 25.6%) did not hold references or citations in common with other articles. The number of common references and citations increased in articles reporting instructional design principles (P=.03), articles measuring online activities (P=.01), and articles citing a review by Cook and colleagues on CBL (P=.04). There was an association between number of citations and studies comparing CBL versus CBL, independent of publication date (P=.02).

Conclusions

Studies in this field vary highly, and a high number of software systems are being developed. It seems that past recommendations regarding CBL interventions are being taken into consideration. A move into a more student-centered model, a focus on implementing reusable software platforms for specific learning contexts, and the analysis of online activity to track and predict outcomes are relevant areas for future research in this field.

Modeling stream fish distributions using interval-censored detection times

Controlling for imperfect detection is important for developing species distribution models (SDMs). Occupancy-detection models based on the time needed to detect a species can be used to address this problem, but this is hindered when times to detection are not known precisely. Here, we extend the time-to-detection model to deal with detections recorded in time intervals and illustrate the method using a case study on stream fish distribution modeling. We collected electrofishing samples of six fish species across a Mediterranean watershed in Northeast Portugal. Based on a Bayesian hierarchical framework, we modeled the probability of water presence in stream channels, and the probability of species occupancy conditional on water presence, in relation to environmental and spatial variables. We also modeled time-to-first detection conditional on occupancy in relation to local factors, using modified interval-censored exponential survival models. Posterior distributions of occupancy probabilities derived from the models were used to produce species distribution maps. Simulations indicated that the modified time-to-detection model provided unbiased parameter estimates despite interval-censoring. There was a tendency for spatial variation in detection rates to be primarily influenced by depth and, to a lesser extent, stream width. Species occupancies were consistently affected by stream order, elevation, and annual precipitation. Bayesian P-values and AUCs indicated that all models had adequate fit and high discrimination ability, respectively. Mapping of predicted occupancy probabilities showed widespread distribution by most species, but uncertainty was generally higher in tributaries and upper reaches. The interval-censored time-to-detection model provides a practical solution to model occupancy-detection when detections are recorded in time intervals. This modeling framework is useful for developing SDMs while controlling for variation in detection rates, as it uses simple data that can be readily collected by field ecologists.

Legacy Pollutants are Declining in Great Skuas (Stercorarius skua) but Remain Higher in Faroe Islands than in Scotland

To monitor environmental pollutants in Faroese biota, samples from a top predator were analysed and put into a spatial and temporal context. Analysis of 20 Great Skua eggs sampled in 2012 from the Faroe Islands showed >70 % lower concentrations of legacy persistent organic pollutants (POPs) than in samples analysed in 1977. The 2012 Faroese eggs showed higher concentrations than for eggs in Shetland from about the same period (2008). Eggshells were analysed for sub-lethal effects but there were no detectable effects of legacy POP levels on eggshell colour or thickness. A temporal decline in legacy POPs would indicate a reduction in the general pollutant levels present in the environment as has been shown in other areas of the North Atlantic, but there are significant geographic differences in POPs levels likely due to differences in diet resulting in significantly different exposures on a relatively limited spatial scale.

CopyMean: A new method to predict monotone missing values in longitudinal studies

BACKGROUND

Longitudinal studies are those in which the same variable is repeatedly measured at different times. More likely than others, these studies suffer from missing values. Because the missing values may impact the statistical analyses, it is important that they be dealt with properly.

METHODS

In this paper, we present "CopyMean", a new method to impute (predict) monotone missing values. We compared its efficiency to sixteen imputation methods dedicated to the treatment of missing values in longitudinal data. All these methods were tested on four datasets, real or artificial, presenting markedly different caracteristics.

RESULTS

The analysis showed that CopyMean was more efficient in almost all situations.

Drivers of Spatial Variation in the Role of Ants as Secondary Seed Dispersers

The spatial variation in the outcome of the interaction between secondary dispersers and seeds is superimposed upon the variation produced by primary dispersers. Investigating the factors that drive the outcome of the interactions with secondary seed dispersers thus represents an essential refinement to our understanding of the complete seed dispersal process. We studied the interactions between two ponerine ants (Pachycondyla striata Smith, 1858 and Odontomachus chelifer (Latreille, 1802)) with fruits experimentally set on the ground, and estimated the effects of ants on seedling establishment in three areas distributed along a 2-km stretch of a Brazilian Atlantic rainforest that differ in soil properties and vegetation physiognomies. We tested the hypothesis that interactions are more frequent, resulting in greater seedling establishment at the site with harsher abiotic and biotic conditions. Both ant species removed fruits frequently and have a positive effect on seedling establishment in all study areas, but fruit removal did not differ among areas, while seedling establishment was more pronounced at the site with stressful abiotic conditions. The two ant species differed in important aspects of their seed dispersal services, including the propensity to interact with seeds. As a result, both the species of ant and abiotic conditions interact at the scale of 2 km to determine the fate of seeds interacting with ants, thus creating a mosaic of outcomes with variable benefits to plants.

Response retrieval and motor planning during typing

Recent work in language production research suggests complex relationships between linguistic and motor processes. Typing is an interesting candidate for investigating further this issue. First, typing presumably relies on the same distributed left-lateralized brain network as handwriting and speech production. Second, typing has its own set of highly specific motor constraints, such as internal keystroke representations that hold information about both letter identity and spatial characteristics of the key to strike. The present study aims to further develop research on typed production, by targeting the dynamics between linguistic and motor neural networks. Specifically, we used a typed picture-naming task to examine the interplay between response retrieval and motor planning. To track processes associated with both linguistic processing and keystroke representation, we manipulated, respectively, the semantic context in which the target appeared and the side of the first keystrokes of the word. We recorded high-density electroencephalography (EEG) continuously from the presentation of a picture, to the typing of its name, and computed both event-related potentials (ERP) and beta-band power analyses. Non-parametric data-driven analysis revealed a clear pattern of response preparation over both hemispheres close to response time, in both the ERP and beta-band power modulations. This was preceded by a left-lateralized power decrease in the beta-band, presumably representing memory retrieval, and an early contrast in ERP, between left and right keystrokes' preparation. We discuss these results in terms of a dynamic access approach for internal keystroke representations, and argue for an integrative rather than separatist view of linguistic and motor processes.

Sea anemones modify their hiding time based on their commensal damselfish

Animals often retreat to refugia when alarmed and the time they spend hiding reflects an economic decision that trades off reducing predation risk with other beneficial activities. Typically, refugia such as burrows are static, but some refugia are dynamic. For species with defensive mutualisms, hiding might be contingent on their mutualist's behaviour. We disturbed and quantified hiding time in magnificent sea anemones, Heteractis magnifica, and their associated domino damselfish, Dascyllus trimaculatus. We found that sea anemone hiding behaviour was dependent on the number and behaviour of their commensal fish: anemones emerged sooner when they had more associated fish and faster returning fish. Together, these results demonstrate that hiding behaviour can be influenced by the behaviour of a commensal; such dynamic mutualisms may be found in other systems.

Uh and um in children with autism spectrum disorders or language impairment

Atypical pragmatic language is often present in individuals with autism spectrum disorders (ASD), along with delays or deficits in structural language. This study investigated the use of the "fillers" uh and um by children ages 4-8 during the autism diagnostic observation schedule. Fillers reflect speakers' difficulties with planning and delivering speech, but they also serve communicative purposes, such as negotiating control of the floor or conveying uncertainty. We hypothesized that children with ASD would use different patterns of fillers compared to peers with typical development or with specific language impairment (SLI), reflecting differences in social ability and communicative intent. Regression analyses revealed that children in the ASD group were much less likely to use um than children in the other two groups. Filler use is an easy-to-quantify feature of behavior that, in concert with other observations, may help to distinguish ASD from SLI. Autism Res 2016, 9: 854-865. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Assessing Field-Specific Risk of Soybean Sudden Death Syndrome Using Satellite Imagery in Iowa

Moderate resolution imaging spectroradiometer (MODIS) satellite imagery from 2004 to 2013 were used to assess the field-specific risks of soybean sudden death syndrome (SDS) caused by Fusarium virguliforme in Iowa. Fields with a high frequency of significant decrease (>10%) of the normalized difference vegetation index (NDVI) observed in late July to middle August on historical imagery were hypothetically considered as high SDS risk. These high-risk fields had higher slopes and shorter distances to flowlines, e.g., creeks and drainages, particularly in the Des Moines lobe. Field data in 2014 showed a significantly higher SDS level in the high-risk fields than fields selected without considering NDVI information. On average, low-risk fields had 10 times lower F. virguliforme soil density, determined by quantitative polymerase chain reaction, compared with other surveyed fields. Ordinal logistic regression identified positive correlations between SDS and slope, June NDVI, and May maximum temperature, but high June maximum temperature hindered SDS. A modeled SDS risk map showed a clear trend of potential disease occurrences across Iowa. Landsat imagery was analyzed similarly, to discuss the ability to utilize higher spatial resolution data. The results demonstrated the great potential of both MODIS and Landsat imagery for SDS field-specific risk assessment.

A multivariate single-index model for longitudinal data

Abstract:

Index measures are commonly used in medical research and clinical practice, primarily for quantification of health risks in individual subjects or patients. The utility of an index measure is ultimately contingent on its ability to predict health outcomes. Construction of medical indices has largely been based on heuristic arguments, although the acceptance of a new index typically requires objective validation, preferably with multiple outcomes. In this article, we propose an analytical tool for index development and validation. We use a multivariate single-index model to ascertain the best functional form for risk index construction. Methodologically, the proposed model represents a multivariate extension of the traditional single-index models. Such an extension is important because it assures that the resultant index simultaneously works for multiple outcomes. The model is developed in the general framework of longitudinal data analysis. We use penalized cubic splines to characterize the index components while leaving the other subject characteristics as additive components. The splines are estimated directly by penalizing nonlinear least squares, and we show that the model can be implemented using existing software. To illustrate, we examine the formation of an adiposity index for prediction of systolic and diastolic blood pressure in children. We assess the performance of the method through a simulation study.

Daily ambient temperature and renal colic incidence in Guangzhou, China: a time-series analysis

Few previous studies have examined the association between temperature and renal colic in developing regions, especially in China, the largest developing country in the world. We collected daily emergency ambulance dispatches (EADs) for renal colic from Guangzhou Emergency Center from 1 January 2008 to 31 December 2012. We used a distributed-lag nonlinear model in addition to the over-dispersed generalized additive model to investigate the association between daily ambient temperature and renal colic incidence after controlling for seasonality, humidity, public holidays, and day of the week. We identified 3158 EADs for renal colic during the study period. This exposure-response curve was almost flat when the temperature was low and moderate and elevated when the temperature increased over 21 °C. For heat-related effects, the significant risk occurred on the concurrent day and diminished until lag day 7. The cumulative relative risk of hot temperatures (90th percentile) and extremely hot temperatures (99th percentile) over lag days 0-7 was 1.92 (95 % confidence interval, 1.21, 3.05) and 2.45 (95 % confidence interval, 1.50, 3.99) compared with the reference temperature of 21 °C. This time-series analysis in Guangzhou, China, suggested a nonlinear and lagged association between high outdoor temperatures and daily EADs for renal colic. Our findings might have important public health significance to prevent renal colic.

A randomised trial of the effect and cost-effectiveness of early intensive multifactorial therapy on 5-year cardiovascular outcomes in individuals with screen-detected type 2 diabetes: the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION-Europe) study

BACKGROUND

Intensive treatment (IT) of cardiovascular risk factors can halve mortality among people with established type 2 diabetes but the effects of treatment earlier in the disease trajectory are uncertain.

OBJECTIVE

To quantify the cost-effectiveness of intensive multifactorial treatment of screen-detected diabetes.

DESIGN

Pragmatic, multicentre, cluster-randomised, parallel-group trial.

SETTING

Three hundred and forty-three general practices in Denmark, the Netherlands, and Cambridge and Leicester, UK.

PARTICIPANTS

Individuals aged 40-69 years with screen-detected diabetes.

INTERVENTIONS

Screening plus routine care (RC) according to national guidelines or IT comprising screening and promotion of target-driven intensive management (medication and promotion of healthy lifestyles) of hyperglycaemia, blood pressure and cholesterol.

MAIN OUTCOME MEASURES

The primary end point was a composite of first cardiovascular event (cardiovascular mortality/morbidity, revascularisation and non-traumatic amputation) during a mean [standard deviation (SD)] follow-up of 5.3 (1.6) years. Secondary end points were (1) all-cause mortality; (2) microvascular outcomes (kidney function, retinopathy and peripheral neuropathy); and (3) patient-reported outcomes (health status, well-being, quality of life, treatment satisfaction). Economic analyses estimated mean costs (UK 2009/10 prices) and quality-adjusted life-years from an NHS perspective. We extrapolated data to 30 years using the UK Prospective Diabetes Study outcomes model [version 1.3; (©) Isis Innovation Ltd 2010; see www.dtu.ox.ac.uk/outcomesmodel (accessed 27 January 2016)].

RESULTS

We included 3055 (RC, n = 1377; IT, n = 1678) of the 3057 recruited patients [mean (SD) age 60.3 (6.9) years] in intention-to-treat analyses. Prescription of glucose-lowering, antihypertensive and lipid-lowering medication increased in both groups, more so in the IT group than in the RC group. There were clinically important improvements in cardiovascular risk factors in both study groups. Modest but statistically significant differences between groups in reduction in glycated haemoglobin (HbA1c) levels, blood pressure and cholesterol favoured the IT group. The incidence of first cardiovascular event [IT 7.2%, 13.5 per 1000 person-years; RC 8.5%, 15.9 per 1000 person-years; hazard ratio 0.83, 95% confidence interval (CI) 0.65 to 1.05] and all-cause mortality (IT 6.2%, 11.6 per 1000 person-years; RC 6.7%, 12.5 per 1000 person-years; hazard ratio 0.91, 95% CI 0.69 to 1.21) did not differ between groups. At 5 years, albuminuria was present in 22.7% and 24.4% of participants in the IT and RC groups, respectively [odds ratio (OR) 0.87, 95% CI 0.72 to 1.07), retinopathy in 10.2% and 12.1%, respectively (OR 0.84, 95% CI 0.64 to 1.10), and neuropathy in 4.9% and 5.9% (OR 0.95, 95% CI 0.68 to 1.34), respectively. The estimated glomerular filtration rate increased between baseline and follow-up in both groups (IT 4.31 ml/minute; RC 6.44 ml/minute). Health status, well-being, diabetes-specific quality of life and treatment satisfaction did not differ between the groups. The intervention cost £981 per patient and was not cost-effective at costs ≥ £631 per patient.

CONCLUSIONS

Compared with RC, IT was associated with modest increases in prescribed treatment, reduced levels of risk factors and non-significant reductions in cardiovascular events, microvascular complications and death over 5 years. IT did not adversely affect patient-reported outcomes. IT was not cost-effective but might be if delivered at a reduced cost. The lower than expected event rate, heterogeneity of intervention delivery between centres and improvements in general practice diabetes care limited the achievable differences in treatment between groups. Further follow-up to assess the legacy effects of early IT is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00237549.

FUNDING DETAILS

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 64. See the NIHR Journals Library website for further project information.

Natural disturbance impacts on ecosystem services and biodiversity in temperate and boreal forests

In many parts of the world forest disturbance regimes have intensified recently, and future climatic changes are expected to amplify this development further in the coming decades. These changes are increasingly challenging the main objectives of forest ecosystem management, which are to provide ecosystem services sustainably to society and maintain the biological diversity of forests. Yet a comprehensive understanding of how disturbances affect these primary goals of ecosystem management is still lacking. We conducted a global literature review on the impact of three of the most important disturbance agents (fire, wind, and bark beetles) on 13 different ecosystem services and three indicators of biodiversity in forests of the boreal, cool- and warm-temperate biomes. Our objectives were to (i) synthesize the effect of natural disturbances on a wide range of possible objectives of forest management, and (ii) investigate standardized effect sizes of disturbance for selected indicators via a quantitative meta-analysis. We screened a total of 1958 disturbance studies published between 1981 and 2013, and reviewed 478 in detail. We first investigated the overall effect of disturbances on individual ecosystem services and indicators of biodiversity by means of independence tests, and subsequently examined the effect size of disturbances on indicators of carbon storage and biodiversity by means of regression analysis. Additionally, we investigated the effect of commonly used approaches of disturbance management, i.e. salvage logging and prescribed burning. We found that disturbance impacts on ecosystem services are generally negative, an effect that was supported for all categories of ecosystem services, i.e. supporting, provisioning, regulating, and cultural services (P < 0.001). Indicators of biodiversity, i.e. species richness, habitat quality and diversity indices, on the other hand were found to be influenced positively by disturbance (P < 0.001). Our analyses thus reveal a 'disturbance paradox', documenting that disturbances can put ecosystem services at risk while simultaneously facilitating biodiversity. A detailed investigation of disturbance effect sizes on carbon storage and biodiversity further underlined these divergent effects of disturbance. While a disturbance event on average causes a decrease in total ecosystem carbon by 38.5% (standardized coefficient for stand-replacing disturbance), it on average increases overall species richness by 35.6%. Disturbance-management approaches such as salvage logging and prescribed burning were neither found significantly to mitigate negative effects on ecosystem services nor to enhance positive effects on biodiversity, and thus were not found to alleviate the disturbance paradox. Considering that climate change is expected to intensify natural disturbance regimes, our results indicate that biodiversity will generally benefit from such changes while a sustainable provisioning of ecosystem services might come increasingly under pressure. This underlines that disturbance risk and resilience require increased attention in ecosystem management in the future, and that new approaches to addressing the disturbance paradox in management are needed.

Biology and Seasonality of the Reemergent Pest Rhynchaenus pallicornis (Coleoptera: Curculionidae) and Methods for Monitoring Its Abundance

Rhynchaenus pallicornis (Say) is a pest of commercially grown apples in the upper Midwest. This historic pest has resurged and caused severe yield loss on farms using certified organic production practices. The life history and potential monitoring methods of R. pallicornis are presented. Seasonal abundance data were collected through beat and visual sampling. A phenological model was developed for R. pallicornis. The minimum developmental threshold of R. pallicornis was determined to be 3.5°C with a required degree-day accumulation of 125°D for first adult emergence. Larval damage was observed on >60% of leaves in unmanaged orchards and affected significantly fewer basal leaf clusters (near the trunk), than medially or apically located clusters. Of 2,900 R. pallicornis larval mines collected over two years at three different sites, 18.0% produced at least one adult parasitoid, but the targeted larval stage is unknown. Measurements of R. pallicornis larval head capsules and the simple frequency method were used to determine three larval instars of R. pallicornis The number of larval instars could also be accurately determined by observing the presence or absence of two sets of thoracic sclerites. Pyramid traps, yellow sticky cards baited with olfactory cues (pear essence, benzaldehyde, and an aggregation of adult R. pallicornis) were evaluated as R. pallicornis monitoring tools. None of the traps or lures tested significantly affected the number of adult R. pallicornis per trap.

Exposure to Violence During Ferguson Protests: Mental Health Effects for Law Enforcement and Community Members

There is little information available on the mental health effects of exposure to shared community violence such as the August 2014 violence that occurred in Ferguson, Missouri. This study sought to examine the relationship between proximity to community violence and mental health in both community members and police officers. We recruited 565 adults (community, n = 304, and police, n = 261) exposed to the violence in Ferguson to complete measures of proximity to violence, posttraumatic stress, depression, and anger. Using structural equation modeling, we assessed aspects of proximity to violence-connectedness, direct exposure, fear from exposure, media exposure, reactions to media, and life interruption-as correlates of posttraumatic stress disorder (PTSD) symptoms, depression, and anger. The final model yielded (n = 432), χ(2) (d = 12) = 7.4, p = .830; comparative fit index = 1.0, root mean square error of approximation = 0 [0, .04]. All aspects of proximity except direct exposure were associated with mental health outcomes. There was no moderation as a function of community versus police. Race moderated the relationship between life interruptions and negative outcomes; interruption was related to distress for White, but not Black community members. Based on group comparisons, community members reported more symptoms of PTSD and depression than law enforcement (ηp (2) = .06 and .02, respectively). Black community members reported more PTSD and depression than White community members (ηp (2) = .05 and .02, respectively). Overall, distress was high, and mental health interventions are likely indicated for some individuals exposed to the Ferguson events.

Differential endorsement of suicidal ideation and attempt in bipolar versus unipolar depression: a testlet response theory analysis

BACKGROUND

Published data concerning differences in suicide risk across the mood disorders spectrum remain mixed. The current study used testlet response theory methods to evaluate differences in the endorsement of suicidal ideation and attempt in an epidemiological sample of individuals with bipolar and unipolar depression.

METHOD

Participants with lifetime history of bipolar I (n=1154), bipolar II (n=494), and unipolar (n=5695) depression were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions, which included 4 structured queries concerning suicidal ideation/attempt. We estimated differential item functioning between groups with a 2-pl parametric item response model.

RESULTS

Endorsement of suicide items increased as a function of underlying depression severity. Equating for severity, endorsement of suicidal ideation and attempt was generally more frequent in bipolar versus unipolar depression, and in bipolar I versus bipolar II depression. Yet findings were not consistent across all suicide items, and differences were small in magnitude.

LIMITATIONS

The NESARC relied upon lifetime endorsement of suicide items, and suicide risk was only evaluated within the context of a major depressive episode. Thus, this study could not evaluate endorsement of suicide items within the context of (hypo)manic or mixed states.

CONCLUSION

Although there were some group differences, patterns of item endorsement were more similar than different. These data support a transdiagnostic model of suicide that emphasizes underlying depression severity over mood disorder class.

Consequences of inoculation with native arbuscular mycorrhizal fungi for root colonization and survival of Artemisia tridentata ssp. wyomingensis seedlings after transplanting

In arid environments, the propagule density of arbuscular mycorrhizal fungi (AMF) may limit the extent of the plant-AMF symbiosis. Inoculation of seedlings with AMF could alleviate this problem, but the success of this practice largely depends on the ability of the inoculum to multiply and colonize the growing root system after transplanting. These phenomena were investigated in Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) seedlings inoculated with native AMF. Seedlings were first grown in a greenhouse in soil without AMF (non-inoculated seedlings) or with AMF (inoculated seedlings). In spring and fall, 3-month-old seedlings were transplanted outdoors to 24-L pots containing soil from a sagebrush habitat (spring and fall mesocosm experiments) or to a recently burned sagebrush habitat (spring and fall field experiments). Five or 8 months after transplanting, colonization was about twofold higher in inoculated than non-inoculated seedlings, except for the spring field experiment. In the mesocosm experiments, inoculation increased survival during the summer by 24 % (p = 0.011). In the field experiments, increased AMF colonization was associated with increases in survival during cold and dry periods; 1 year after transplanting, survival of inoculated seedlings was 27 % higher than that of non-inoculated ones (p < 0.001). To investigate possible mechanisms by which AMF increased survival, we analyzed water use efficiency (WUE) based on foliar (13)C/(12)C isotope ratios (δ (13)C). A positive correlation between AMF colonization and δ (13)C values was observed in the spring mesocosm experiment. In contrast, inoculation did not affect the δ (13)C values of fall transplanted seedlings that were collected the subsequent spring. The effectiveness of AMF inoculation on enhancing colonization and reducing seedling mortality varied among the different experiments, but average effects were estimated by meta-analyses. Several months after transplanting, average AMF colonization was in proportion 84 % higher in inoculated than non-inoculated seedlings (p = 0.0042), while the average risk of seedling mortality was 42 % lower in inoculated than non-inoculated seedlings (p = 0.047). These results indicate that inoculation can increase AMF colonization over the background levels occurring in the soil, leading to higher rates of survival.