General Linear Mixed-effects Models Research Articles

Impact of vaccine stockouts on immunization coverage in Nigeria

Improving immunization coverage requires creating reliable supply of vaccines and immunization supplies; trained and incentivized health workers; and strategies to improve the demand for immunization. Yet, the interplay of demand and supply side factors on immunization coverage has not been evaluated in literature with data. We use data from Nigeria and a mixed-effects general linear model to estimate the effect of vaccine availability on routine immunization coverage and to identify demand and health system factors which affect this relationship. We find that when vaccine stockouts occur at Local Government Area stores in Nigeria, they significantly decrease the number of children immunized, and for most vaccines, the effect lasts for several months after a stockout. Some of the demand lost when a stockout occurs is recovered over the following six months as children catch up with the regimen. The magnitude of the impact varies across different vaccines.

Racial/Ethnic Disparities in Dental Service Utilization for Foreign-Born and U.S.-Born Middle-Aged and Older Adults.

This study examines racial/ethnic disparities of dental service utilization for foreign-born and U.S.-born dentate residents aged 50 years and older. Generalized linear mixed-effects models (GLMM) were used to perform longitudinal analyses of five-wave data of dental service utilization from the Health and Retirement Study (HRS). We used stratified analyses for the foreign-born and U.S.-born and assessed the nonlinear trend in rates of dental service utilization for different racial/ethnic groups. Findings indicate that Whites had higher rates of service utilization than Blacks and Hispanics regardless of birthplace. For all groups, the rates of service utilization decreased around age 80, and the rates of decline for Whites were slower than others. The U.S.-born showed the trend of higher rates of service utilization than the foreign-born for all racial/ethnic groups. These findings suggest the importance of developing culturally competent programs to meet the dental needs of the increasingly diverse populations in the United States.

Density of low-barrier opioid agonist clinics and risk of non-fatal overdose during a community-wide overdose crisis: A spatial analysis

ObjectivesIn recent years, North America has witnessed a spike in the number of overdoses (OD) and OD-related deaths. The aim of this study was to assess spatial correlates of OD risk in Vancouver, Canada. MethodsData utilized for this study was from three open and ongoing prospective cohorts of people who use drugs (PWUDs) in Vancouver, Canada. Logistic regression analyses with generalized linear mixed-effects models (GLMM) was used to examine correlates of residing in areas characterized by high OD rates. Mapping was used to examine areas showing OD clusters. ResultsWe included 1336 PWUDs who resided in the downtown area. In multivariable analysis, higher availability of methadone clinics within walking distance, daily cocaine injectors and daily crack users had independent decreased odds of living within an OD cluster. ConclusionThis study found that higher availability of methadone clinics was associated with decreased odds of living within OD clusters.

Associations Among School Day Sedentary Behavior, Physical Activity, and Motor Skills: A Compositional Data Analysis

PURPOSE: A novel analytic approach, Compositional Data Analysis (CoDa), has recently been used to analyze physical activity data. CoDa assumes co-dependence among physical activity compositional parts within a time-constrained data analytic framework, which makes it appropriate for assessing and analyzing physical activity behavior during school hours. The purpose of this study was to examine the relationships among school day sedentary times (SED), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with gross motor skills in children using Compositional Data Analysis (CoDa). METHODS: Participants were 409 children (Mean age = 8.4±1.8 years) recruited across five low-income schools. Gross Motor Skills were assessed using the Test of Gross Motor Development - 3rdEdition (TGMD-3) and physical activity was assessed using accelerometers. Isometric Log Ratio coordinates (ILRs) were calculated quantifying the relative proportion of percent of the school day (%) spent in SED, LPA, and MVPA. The associations of the ILRs with the TGMD-3 scores were estimated using general linear mixed effects models adjusted for age, BMI, and estimated VO2Peak. RESULTS: A higher proportion of the school day spent in %MVPA relative to %SED and %LPA significantly associated with higher TGMD-3 total scores (γMVPA= 14.44, P= 0.012). This relationship was also observed for the ball skills subtest scores (γMVPA= 16.12, P= 0.003). A 5% reallocation in % of time spent in SED and LPA to MVPA was independently associated with a 0.48 and 1.74-point increase in ball skills scores, respectively, after controlling for the potential confounders of age, BMI, and estimated VO2Peak. CONCLUSIONS: Replacing %SED and %LPA with %MVPA during school hours may an effective strategy for improving gross motor skills, specifically ball skills, in low-income elementary school-aged children.

No Differences in Sub-Cortical Motor Region Activity for Knee Motor Control Following Anterior Cruciate Ligament Reconstruction

PURPOSE: Emerging research has indicated that anterior cruciate ligament reconstruction (ACL-R) is associated with neuroplasticity. It has been speculated that these findings may have future implications on rehabilitation and ACL-R outcomes. However, most of this research has focused on cortical plasticity rather than sub-cortical plasticity. The purpose of this project was to determine the effects of ACL-R on sub-cortical portions of the cortical-subcortical motor loop. METHODS: A healthy group of active participants (n=16, age=23.2±3.5 years, height=1.7±0.1 m, weight=69.7±14.3 kg) and a left ACL-R group (n=15, age=21.7±2.7 years, height=1.7±0.1 m, weight=70.4±15.8 kg, 38.1±27.2 months’ post-surgery) were locally recruited. Functional magnetic resonance imaging (fMRI) and T1 structural imaging were performed to analyze brain activation during a unilateral left (involved) 45° knee extension/flexion at a rate of 1.2 Hz for 4 blocks of 30 seconds interspersed with 30 seconds of rest. The right putamen and right sub-thalamic nuclei (STN) served as seed regions, and the two groups were contrasted using a mixed-effects general linear model with a priori cluster threshold of p<.05. RESULTS: Compared to the control group, the ACL-R group displayed no differences in right putamen and right STN activation during the unilateral motor task. CONCLUSION: These results indicate that ACL-R may not influence the motor control loop at the sub-cortical level. Therefore, motor control and motor learning, as it relates to the subcortical structures, may not be affected by ACL-R. As a result, neurorehabilitation after ACL-R should use priming techniques to target specific cortical regions that previous studies have indicated as being affected by ACL-R.

Platycodi Radix Beverage Reduced the Postprandial Lipemia Response to a High-fat Load in Randomized Controlled Trials of Healthy Subjects (P12-009-19)

ObjectivesHigh postprandial lipemia is a characteristic of metabolic abnormality recognized as a risk factor inducing cardiovascular disease. The objective of this study was to investigate the effects of Platycodi radix (PR) beverage on postprandial lipemia response after challenging with a high-fat/sugar load using both single-dose cross-over and 8-week repeated paralleled designs in healthy subjects. MethodsA total of 52 and 96 subjects were included in the two studies, respectively. Postprandial blood samples were collected at designated time points from 0 to 6 hours after a high-fat load at each visit to determine triglyceride (TG) and lipoprotein lipase (LPL) activity and mass in plasma, chylomicron and very low-density lipoprotein (VLDL). A general linear mixed-effect model analysis of time point values and area under the curves (AUCs) was performed to estimate the effect of PR beverage on postprandial lipemia response. ResultsIn a single-dose cross-over design study, PR beverage consumption significantly increased lipoprotein lipase mass (P = 0.011, β estimate = 4.295) and reduced TG concentration in VLDL (P = 0.038, β estimate = –52.69) at 6-hour as compared to those in placebo consumption with a high-fat load. Postprandial TG responses as measured by AUC for 6 hours were significantly correlated with a high-fat dietary score MEDFICTS in chylomicron (r = 0.276, P = 0.008) and VLDL (r = 0.213, P = 0.040). In a 8-week repeated parallel design study, postprandial lipemia responses were compared considering the interaction between group and week. PR beverage consumption decreased postprandial serum TG response (AUCn, P = 0.039; total AUC, P = 0.088). In addition, PR increased plasma LPL mass (AUCn, P = 0.076) that is a clearing factor that hydrolyzed TG of chylomicron and VLDL in the lipoprotein metabolism. ConclusionsIn both of single and long-term intake, PR beverage consumption improved the degradation of postprandial TG level with increasing postprandial LPL mass. However, detail LPL mechanisms of PR consumption should be further analyzed. Funding SourcesThis work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development” Rural Development Administration, Republic of Korea and the BK21 PLUS program of the Ministry of Education.

A computational note on maximum likelihood estimation in random effects panel probit model

Panel data sets have recently been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Often a dichotomous dependent variable occur in survival analysis, biomedical and epidemiological studies that is analyzed by a generalized linear mixed effects model (GLMM). The most common estimation method for the binary panel data may be the maximum likelihood (ML). Many statistical packages provide ML estimates; however, the estimates are computed from numerically approximated likelihood function. For instance, R packages, pglm (Croissant, 2017) approximate the likelihood function by the Gauss–Hermite quadratures, while Rchoice (Sarrias, Journal of Statistical Software, 74, 1–31, 2016) use a Monte Carlo integration method for the approximation. As a result, it can be observed that different packages give different results because of different numerical computation methods. In this note, we discuss the pros and cons of numerical methods compared with the exact computation method.

Ash Dieback and Its Impact in Near-Natural Forest Remnants - A Plant Community-Based Inventory.

Temperate European forests are currently largely under attack by the infection with Hymenoscyphus fraxineus, a fungal pathogen introduced from Asia since at least the early 1990s and causing a major dieback of common ash (Fraxinus excelsior) throughout Europe. At present, ash dieback evokes major problems for forestry, in particular in sensitive forest remnants in Northern Germany, where the disease causes serious concerns for ecosystem conservation. This makes ash dieback a focal area of ecological research. In the present study, we quantified the extent of ash dieback in adult and in young ash trees in Northern Schleswig-Holstein, Germany, in relation to community composition and associated biotic and abiotic factors. Data collection was carried out in 37 plots in communities of ash-rich forests and included floristic inventory, rating of adult and young ash individuals and recording of light and soil conditions. Data were analyzed using non-metric multidimensional scaling and general linear mixed effects models. Forest type was the strongest significant predictor for variation in crown defoliation of adult ash trees. Damage was highest in communities of wet alder-ash forests and lowest in ash-rich beech forests. A further significant predictor of adult crown defoliation was individual height of the ash tree with larger trees being less affected than smaller ones. For juveniles, total species richness displayed a significant positive relationship with the proportional abundance of fungal infection, while the mean damage proportion per individual significantly increased with increasing relative light intensity in the understorey. The study clearly shows a strong relationship between forest type and ecosystem vulnerability to ash dieback. In particular, communities belonging to the species-rich wet alder-ash forests were most severely affected by ash disease, thereby deserving special attention among the vulnerable fragmented forest remnants in Schleswig-Holstein. Co-varying factors, however, seem to differ between juvenile and adult trees, hinting at the relative importance of tree performance for the adult trees and abiotic conditions for the juveniles. Accounting for such differences along a larger ecological gradient of ash forest communities will be necessary to more comprehensively understand effects of ash dieback on the ecosystem and needs to be addressed in future research.

An additive Gaussian process regression model for interpretable non-parametric analysis of longitudinal data

Biomedical research typically involves longitudinal study designs where samples from individuals are measured repeatedly over time and the goal is to identify risk factors (covariates) that are associated with an outcome value. General linear mixed effect models are the standard workhorse for statistical analysis of longitudinal data. However, analysis of longitudinal data can be complicated for reasons such as difficulties in modelling correlated outcome values, functional (time-varying) covariates, nonlinear and non-stationary effects, and model inference. We present LonGP, an additive Gaussian process regression model that is specifically designed for statistical analysis of longitudinal data, which solves these commonly faced challenges. LonGP can model time-varying random effects and non-stationary signals, incorporate multiple kernel learning, and provide interpretable results for the effects of individual covariates and their interactions. We demonstrate LonGP’s performance and accuracy by analysing various simulated and real longitudinal -omics datasets.

Are diurnal time-budgets and activity patterns density-dependent in the Shelduck (Tadorna tadorna) wintering in Algeria? An analysis across multiple temporal scales

BackgroundThe Shelduck (Tadorna tadorna) is a characteristic waterbird species of inland wetlands in northeastern Algeria. Its wintering behavior in relation to changes of local abundances and foraging group density is poorly known.ObjectivesThis study aims at monitoring patterns of diurnal activities and the variation of behavioral time-budgets in relation to numbers of wintering Shelducks. We investigate temporal variations of diurnal activities across multiple-time scales and consider their interrelationships.MethodsAssessments of local population abundance were weekly surveyed during two wintering seasons (2010–2012), whereas diurnal activities (feeding, sleeping, swimming, preening, loafing, flying, courtship, and antagonism) were studied three times a month during seven hours (08:00–16:00) using the Scan method. Time budget variations of each behavioral activity were tested using nested ANOVAs following multiple time scales. Generalized linear mixed-effects models (GLMM) tested whether variations in diurnal activities were density-dependent.ResultsDuring the wintering season, Shelduck’s numbers followed a bell-shaped trend, which indicated that the species was typically a wintering migrant in Sabkha Djendli. The first individuals arrived onsite in October–November then numbers reached a peak in January (up to 2400 individuals in 2012) with steady density during December–February, afterward individuals left the site progressively until late April when the site is deserted. During both wintering seasons, diurnal activities were dominated by feeding (60%), followed by sleeping (12%) then swimming and preening with 9% and 8%, respectively. The rest of the activities (loafing, flying, courtship and antagonistic behaviors) had low proportions of time budget. ANOVAs showed that activity time budgets varied significantly following multiple time scales (year, season, month, day, semi-hour). Time budgets of diurnal activities during each wintering season were significantly interrelated. Correlations patterns between the two seasons were similar. GLMMs revealed that the variations of diurnal activities were not density-dependent, except for preening and swimming.ConclusionDuring the wintering season, habitats of Sabkha Djendli are important for waterbirds, including the Shelduck that used the lake mainly for food-foraging and resting. The 2400 individuals censused in mid-winter are important locally and at the North African scale. This stresses the need to strengthen the protection status of this wetland and mitigate degradation sources that threaten wintering waterfowl.

Pharmacological baroreflex testing with fMRI reveals baroreflex mediated brainstem nuclei

BackgroundBrainstem nuclei mediate baroreflex adjustments in efferent sympathetic and parasympathetic traffic. Yet, human brainstem physiology is poorly understood given the lack of suitable methodology. We developed a novel approach combining pharmacological testing, beat‐by‐beat cardiovascular monitoring, and high‐resolution functional magnetic resonance imaging (fMRI) to assess human baroreflex regulation at the level of the brainstem.Method and materialsIn 11 healthy men (30.7 ±6.6 years; 24.1 ±1.9 kg/m2), we monitored continuous finger arterial blood pressure and ECG using customized hardware during multiband fMRI brain acquisitions. We applied repeated intravenous phenylephrine (PHE, 25 and 75 μg, n=8) and nitroprusside (NTP 25 and 75 μg, n=8) boluses using a remote controlled injector. Brainstem and hypothalamus fMRI images were analyzed to identify brainstem nuclei involved in baroreflex‐mediated blood pressure control using with masked general linear model (GLM). BP changes were correlated with the time‐courses of blood‐oxygen‐level dependent (BOLD) signals by mixed‐effects general linear model.ResultsPharmacological baroreflex testing yielded baroreflex sensitivity measurements with typical blood pressure and RR‐interval patterns. Correlation of the baroreflex‐mediated changes in systolic blood pressure with BOLD signals clearly revealed brainstem nuclei. The solitary tract (NTP: 7.3; PHE: 6.0 t‐value), the caudal ventrolateral medulla (PHE: 5.8 t‐value); the rostral ventrolateral medulla (NTP: 5.6; PHE: 7.1 t‐value), the nucleus ambiguus (PHE: 5.8 t‐value), the paraventricular nucleus (NTP:7.1; PHE: 4.5 t‐value), and raphe nuclei (NTP: 5.7; PHE: 6.0 t‐value), were identified with high sensitivity and corrected for multiple comparisons (p &lt; 0.01).ConclusionWe developed novel approach testing baroreflex regulation at the level of the brainstem in humans. The methodology identified baroreflex‐mediated activation and deactivation patterns consistent with previous investigations in animal models. The methodology can be applied to elucidate human physiology and mechanisms of autonomic cardiovascular disease.Support or Funding InformationThis study was funded by the DLR internal cost object 2475023.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Historical Supplier Performance and Strategic Relationship Dissolution: Unintentional but Serious Supplier Error as a Moderator

ABSTRACTHow and why is the association between historical supplier performance and strategic relationship dissolution moderated by an unintentional but serious supplier error? Adopting Assimilation‐Contrast Theory, we propose that this moderation effect can be either negative or positive. As an empirical test, we collected and analyzed data from 256 sourcing professionals participating in a scenario‐based role‐playing experiment. After confirming experimental checks, we fitted a general linear mixed effects model to the data with appropriate controls. We find, ceteris paribus, that a critical‐component supplier with stellar historical performance is less likely to be terminated by the manufacturer than one with marginally‐acceptable historical performance. However, when a critical‐component supplier with stellar historical performance errs, its likelihood of being terminated by the manufacturer increases by a greater extent than when a supplier with marginally‐acceptable historical performance commits the same mistake. This positive supplier performance penalty effect contributes to the buyer‐supplier relationship dissolution literature by identifying how and why the deterrence to relationship dissolution typically engendered by stellar historical supplier performance does not hold. Our results have implications for how manufacturers should evaluate critical‐component suppliers and how critical‐component suppliers should manage ongoing strategic relationships with manufacturers.

Contrasting vegetation change (1974–2015) in hedgerows and forests in an intensively used agricultural landscape

AbstractQuestionsHow did hedgerows and forests change in area between 1974 and 2015 and did hedgerows still show the same vegetation composition in 2015? To what degree did the vegetation change in hedgerows and how do these changes compare to changes in forests? What is the nature of the species that changed and, from these, can we make general inferences about possible drivers of change?LocationThe countryside in the municipality of Turnhout, province of Antwerp, northern Belgium.MethodsThrough a resurvey of 54 and 20 quasi‐permanent plots in hedgerows and forests, respectively, we investigated shifts in the herb layer over the period 1974–2015. The plot‐level mean Ellenberg Indicator Values (EIVs) were calculated and soil samples were taken in 2015. We compared diversity statistics and used used Generalized Linear Mixed‐Effects Models (GLMMs) to detect trends in species richness (SR) and EIVs. Via a non‐metric multidimensional scaling (NMDS) ordination based on the Sørensen dissimilarity, we compared shifts at the community level.ResultsOur study shows severe, but opposite changes in SR in forests and hedgerows. In forests, SR declined and a homogenization occurred. The shifts in EIVs indicate that forest vegetation evolved to more shade‐tolerant and nutrient‐demanding species, likely due to eutrophication combined with natural forest succession. In hedgerows, SR significantly increased. The species pool became more diverse and more heterogeneous. Changes in EIVs suggest a change towards more light‐demanding species, possibly caused by fragmentation of the network, and towards species indicative for nutrient‐rich habitats, benefiting from eutrophication.ConclusionsIn general, SR in hedgerows is higher than in forests in our studied region, being a suitable habitat for a wide range of plant species in the countryside. However, the loss of almost 30% of the hedgerow habitat in 41 years confronts us with the challenge of protecting the hedgerow remnants, in the interest of agro‐biodiversity.

Cerebral perfusion changes in presymptomatic genetic frontotemporal dementia: a GENFI study.

Genetic forms of frontotemporal dementia are most commonly due to mutations in three genes, C9orf72, GRN or MAPT, with presymptomatic carriers from families representing those at risk. While cerebral blood flow shows differences between frontotemporal dementia and other forms of dementia, there is limited evidence of its utility in presymptomatic stages of frontotemporal dementia. This study aimed to delineate the cerebral blood flow signature of presymptomatic, genetic frontotemporal dementia using a voxel-based approach. In the multicentre GENetic Frontotemporal dementia Initiative (GENFI) study, we investigated cross-sectional differences in arterial spin labelling MRI-based cerebral blood flow between presymptomatic C9orf72, GRN or MAPT mutation carriers (n = 107) and non-carriers (n = 113), using general linear mixed-effects models and voxel-based analyses. Cerebral blood flow within regions of interest derived from this model was then explored to identify differences between individual gene carrier groups and to estimate a timeframe for the expression of these differences. The voxel-based analysis revealed a significant inverse association between cerebral blood flow and the expected age of symptom onset in carriers, but not non-carriers. Regions included the bilateral insulae/orbitofrontal cortices, anterior cingulate/paracingulate gyri, and inferior parietal cortices, as well as the left middle temporal gyrus. For all bilateral regions, associations were greater on the right side. After correction for partial volume effects in a region of interest analysis, the results were found to be largely driven by the C9orf72 genetic subgroup. These cerebral blood flow differences first appeared approximately 12.5 years before the expected symptom onset determined on an individual basis. Cerebral blood flow was lower in presymptomatic mutation carriers closer to and beyond their expected age of symptom onset in key frontotemporal dementia signature regions. These results suggest that arterial spin labelling MRI may be a promising non-invasive imaging biomarker for the presymptomatic stages of genetic frontotemporal dementia.

Influence of the number of calves and lactating adult females in a herd on the adrenocortical activity of free-ranging Asian elephants

Abstract ContextPhysiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand how the elephants’ stress levels are influenced by socio-ecological factors when not directly exposed to human-induced threats, and to use this understanding to improve conservation and management strategies. AimsThe present study was designed to provide baseline information on the link between socio-ecological factors and stress levels of undisturbed populations of elephants. The main aim was to determine the influence of a number of factors – herd size, season, number of calves and adult females present in a herd and their lactational status and body condition – on the adrenocortical activity of free-ranging adult female Asian elephants living in protected forests (without any direct exposure to human-induced threats), by measuring their faecal glucocorticoid metabolite (fGCM) levels. MethodsA total of 145 fresh faecal samples were collected from 123 identified adult female elephants inhabiting Bandipur and Nagarahole National Parks of southern India, between the years 2013 and 2015. fGCM levels were measured by employing a group-specific standardised 11-oxoetiocholanolone enzyme immunoassay (EIA). A generalised linear mixed-effects model (GLMM) was used to assess the influence of socio-ecological factors on fGCM levels of adult female elephants. Key resultsWhen fGCM levels were analysed with a GLMM, the following patterns were observed: fGCM levels were negatively correlated with the number of adult females (herd size) and positively correlated with the number of calves in a herd and active lactational status of an adult female. fGCM levels of adult female elephants were higher during the dry season (February to May) than wet season (August to December) and negatively correlated with body condition scores. ConclusionsAdrenocortical activity of female elephants is significantly influenced by the number of calves and adult females present in the herd, seasonality and lactational status. ImplicationsIt is important to consider the influence of multiple ecological and social correlates when assessing and interpreting the adrenocortical activity of Asian elephants. Our findings highlight the importance of maintaining the social structure of elephants in the wild to avoid detrimental effects on their physiological health. Insights from such assessments could be used to evaluate the stress in elephants that are involved in direct conflicts with humans to take appropriate management decisions for mitigating conflicts.

Children’s Weight Gain and Cardiovascular Fitness Loss over the Summer

The purpose of this study was to examine the impact of summer breaks on the body composition and cardiovascular fitness of elementary school children who participated in a multi-year school-based physical activity intervention. Participants were 404 children who had their height and weight measured and completed the Progressive Aerobic Cardiovascular Endurance Run (PACER) during physical education classes at the beginning and end of the school year for three consecutive years. To examine the effects of time on health-related fitness data, general linear mixed effects models were employed. The results indicate that there was a trend toward an increase in body mass index (BMI) after the summer of 2015 (p = 0.958), and a significant increase in BMI after the summer of 2016 compared to time point 1 (p < 0.001). For PACER laps, there were trends toward decreases in PACER laps after the summers of 2015 (p = 0.515) and 2016 (p = 0.073). Summer breaks tended to attenuate the BMI and PACER lap improvements that were observed during the intervention. While school-based physical activity programming has had some successes in improving health-related fitness markers, the loss of these improvements over the summer is of concern to both practitioners and researchers. It is clear that additional efforts are needed to limit obesogenic behaviors during the summer months.

Black swans in space: modeling spatiotemporal processes with extremes.

In ecological systems, extremes can happen in time, such as population crashes, or in space, such as rapid range contractions. However, current methods for joint inference about temporal and spatial dynamics (e.g., spatiotemporal modeling with Gaussian random fields) may perform poorly when underlying processes include extreme events. Here we introduce a model that allows for extremes to occur simultaneously in time and space. Our model is a Bayesian predictive-process GLMM (generalized linear mixed-effects model) that uses a multivariate-t distribution to describe spatial random effects. The approach is easily implemented with our flexible R package glmmfields. First, using simulated data, we demonstrate the ability to recapture spatiotemporal extremes, and explore the consequences of fitting models that ignore such extremes. Second, we predict tree mortality from mountain pine beetle (Dendroctonus ponderosae) outbreaks in the U.S. Pacific Northwest over the last 16yr. We show that our approach provides more accurate and precise predictions compared to traditional spatiotemporal models when extremes are present. Our R package makes these models accessible to a wide range of ecologists and scientists in other disciplines interested in fitting spatiotemporal GLMMs, with and without extremes.

Protected areas do not mitigate biodiversity declines: A case study on butterflies

AbstractAimTo assess the effectiveness of protected areas in preventing biodiversity decline. We first test whether species richness of butterfly assemblages is higher within European Natura 2000 (N2000) sites than in their surroundings. We then assess temporal trends in butterfly richness and test whether these trends differ inside and outside the N2000 network.LocationGermany, Europe.MethodsWe utilized generalized linear mixed‐effects models (GLMM) to analyse an 11‐year data series on species richness of butterfly assemblages collected on 245 transects across Germany, located inside and outside N2000 sites, and comprising a total of 122 butterfly species.ResultsButterfly species richness was highest inside N2000 protected areas, while outside it constantly declined with increasing distance from N2000 sites. We found an overall decline in species richness by 10% within 11 years. This decline neither differed between transects located inside or outside the N2000 network nor varied with distance from N2000 sites.Main conclusionsThe higher species richness inside the N2000 network underlines their proper designation and their potential for the conservation of biodiversity. However, the current negative trend in butterfly species richness across Germany is not mitigated by the N2000 network, and we assume insufficient management or measures targeted at other organisms than butterflies as potential reasons.

Changes in Sleep Problems Across Attention-Deficit/Hyperactivity Disorder Treatment: Findings from the Multimodal Treatment of Attention-Deficit/Hyperactivity Disorder Study.

Objective: Stimulant medication and behavior therapy are efficacious for youth with attention-deficit/hyperactivity disorder (ADHD). However, research suggests that stimulants may start and/or worsen sleep problems for youth. Further, the impact of behavior therapy for ADHD on sleep is unknown. This study examined the frequency of sleep problems and effects of stimulant medication, behavior therapy, and their combination on sleep problems in youth with ADHD. This study also explored the influence of dimensional baseline ratings of ADHD symptom subtype and psychiatric comorbidity on sleep outcomes. Methods: Participants were 576 children (aged 7-9 years) with ADHD-Combined type from the Multimodal Treatment of ADHD study that compared methylphenidate, behavior therapy, and their combination to community care. Before treatment, parents completed the Child Behavior Checklist used to derive a total sleep problems score. Parents also completed ratings of oppositionality and ADHD symptom severity, whereas youth completed ratings of depression and anxiety. These ratings were readministered after treatment. Results: General linear mixed-effects models were used to assess change in total sleep problems across treatment. The combined group exhibited a statistically significant reduction in total sleep problems (z = -5.81, p < 0.001). Reductions in total sleep problems in methylphenidate (z = -3.11, p = 0.05), behavior therapy (z = -2.99, p = 0.08), or community care (z = -1.59, p > 0.99) did not reach statistical significance. Change in psychiatric symptoms did not significantly moderate change in total sleep problems by treatment assignment. Greater baseline oppositional defiant disorder severity predicted less reduction in total sleep problems, χ2(1) = 3.86, p < 0.05. Conclusions: Findings suggest that combination of methylphenidate and behavior therapy is efficacious for reducing parent-reported sleep problems in young children with ADHD-Combined type relative to community care. However, potential ameliorative effects of monotherapy treatments (i.e., methylphenidate, behavior therapy) should be examined. Future replication is needed to confirm findings.

The Effects of Aromatherapy on Sleep Quality in Diabetes Patients with Restless Leg Syndrome in Taiwan

This study is a longitudinal experimental design that examine the effects of aromatherapy on sleep quality in diabetes patients with restless leg syndrome (RLS). Patients in the experimental group received the aromatherapy intervention for 6 weeks, while those in the control group received only regular nursing care. The instruments included Pittsburg Sleep Quality Index and SureStep TM of blood glucose meters. Data were collected at pre-test, 2nd week, 4th week, and 6th week after the aromatherapy. Data analysis included descriptive analysis, chi-square, independent t test, Pearson correlation, repeated measure ANOVA and general linear mixed-effect models. Forty-four diabetes patients with RLS were randomly assigned to the experimental group (n=22) and the control group (n=22) at a hospital in northern Taiwan. Sleep quality of diabetes patients with RLS was poor in this study. Sleep latency of patients in the experimental group was improved at 2nd week after aromatherapy. Subjective sleep quality and sleep disturbance of patients was also improved at 4th week after aromatherapy. At 6th week, patients in the experimental group had increased their sleep duration, and improved their overall sleep quality. The level of blood sugar was decreased at 2nd week after aromatherapy on experimental group. Based on the analysis it was concluded that Aromatherapy can ameliorate both blood sugar and sleep quality of diabetes patients with RLS. Thus aromatherapy can be a safe, noninvasive, effective approach for clinical nurses as a therapy in routine care to improve sleep quality in diabetes patients with neuropathy.