Pollinators contribute to the maintenance of flowering plant diversity.

Mechanisms that favour rare species are key to the maintenance of diverse communities1-3. One of the most critical tasks for conservation of flowering plant biodiversity is to understand how plant-pollinator interactions contribute to the maintenance of rare species4-7. Here we show that niche partitioning in pollinator use and asymmetric facilitation confer fitness advantage of rarer species in a biodiversity hotspot using phylogenetic structural equation modelling that integrates plant-pollinator and interspecific pollen transfer networks with floral functional traits. Co-flowering species filtered pollinators via floral traits, and rarer species showed greater pollinator specialization leading to higher pollination-mediated male and female fitness than more abundant species. When plants shared pollinator resources, asymmetric facilitation via pollen transport dynamics benefitted the rarer species at the cost of more abundant species, serving as an alternative diversity-promoting mechanism. Our results emphasize the importance of community-wide plant-pollinator interactions that affect reproduction for biodiversity maintenance.

Using brain structural neuroimaging measures to predict psychosis onset for individuals at clinical high-risk.

Machine learning approaches using structural magnetic resonance imaging (sMRI) can be informative for disease classification, although their ability to predict psychosis is largely unknown. We created a model with individuals at CHR who developed psychosis later (CHR-PS+) from healthy controls (HCs) that can differentiate each other. We also evaluated whether we could distinguish CHR-PS+ individuals from those who did not develop psychosis later (CHR-PS-) and those with uncertain follow-up status (CHR-UNK). T1-weighted structural brain MRI scans from 1165 individuals at CHR (CHR-PS+, n = 144; CHR-PS-, n = 793; and CHR-UNK, n = 228), and 1029 HCs, were obtained from 21 sites. We used ComBat to harmonize measures of subcortical volume, cortical thickness and surface area data and corrected for non-linear effects of age and sex using a general additive model. CHR-PS+ (n = 120) and HC (n = 799) data from 20 sites served as a training dataset, which we used to build a classifier. The remaining samples were used external validation datasets to evaluate classifier performance (test, independent confirmatory, and independent group [CHR-PS- and CHR-UNK] datasets). The accuracy of the classifier on the training and independent confirmatory datasets was 85% and 73% respectively. Regional cortical surface area measures-including those from the right superior frontal, right superior temporal, and bilateral insular cortices strongly contributed to classifying CHR-PS+ from HC. CHR-PS- and CHR-UNK individuals were more likely to be classified as HC compared to CHR-PS+ (classification rate to HC: CHR-PS+, 30%; CHR-PS-, 73%; CHR-UNK, 80%). We used multisite sMRI to train a classifier to predict psychosis onset in CHR individuals, and it showed promise predicting CHR-PS+ in an independent sample. The results suggest that when considering adolescent brain development, baseline MRI scans for CHR individuals may be helpful to identify their prognosis. Future prospective studies are required about whether the classifier could be actually helpful in the clinical settings.

Longitudinal trajectories of cortical development in 22q11.2 copy number variants and typically developing controls.

Probing naturally-occurring, reciprocal genomic copy number variations (CNVs) may help us understand mechanisms that underlie deviations from typical brain development. Cross-sectional studies have identified prominent reductions in cortical surface area (SA) and increased cortical thickness (CT) in 22q11.2 deletion carriers (22qDel), with the opposite pattern in duplication carriers (22qDup), but the longitudinal trajectories of these anomalies-and their relationship to clinical symptomatology-are unknown. Here, we examined neuroanatomic changes within a longitudinal cohort of 261 22q11.2 CNV carriers and demographically-matched typically developing (TD) controls (84 22qDel, 34 22qDup, and 143 TD; mean age 18.35, ±10.67 years; 50.47% female). A total of 431 magnetic resonance imaging scans (164 22qDel, 59 22qDup, and 208 TD control scans; mean interscan interval = 20.27 months) were examined. Longitudinal FreeSurfer analysis pipelines were used to parcellate the cortex and calculate average CT and SA for each region. First, general additive mixed models (GAMMs) were used to identify regions with between-group differences in developmental trajectories. Secondly, we investigated whether these trajectories were associated with clinical outcomes. Developmental trajectories of CT were more protracted in 22qDel relative to TD and 22qDup. 22qDup failed to show normative age-related SA decreases. 22qDel individuals with psychosis spectrum symptoms showed two distinct periods of altered CT trajectories relative to 22qDel without psychotic symptoms. In contrast, 22q11.2 CNV carriers with autism spectrum diagnoses showed early alterations in SA trajectories. Collectively, these results provide new insights into altered neurodevelopment in 22q11.2 CNV carriers, which may shed light on neural mechanisms underlying distinct clinical outcomes.

Developmental influences on symptom expression in antipsychotic-naïve first-episode psychosis.

BACKGROUND: The neurodevelopmental model of psychosis was established over 30 years ago; however, the developmental influence on psychotic symptom expression - how age affects clinical presentation in first-episode psychosis - has not been thoroughly investigated. METHODS: Using generalized additive modeling, which allows for linear and non-linear functional forms of age-related change, we leveraged symptom data from a large sample of antipsychotic-naïve individuals with first-episode psychosis (N = 340, 12-40 years, 1-12 visits), collected at the University of Pittsburgh from 1990 to 2017. We examined relationships between age and severity of perceptual and non-perceptual positive symptoms and negative symptoms. We tested for age-associated effects on change in positive or negative symptom severity following baseline assessment and explored the time-varying relationship between perceptual and non-perceptual positive symptoms across adolescent development. RESULTS: Perceptual positive symptom severity significantly decreased with increasing age (F = 7.0, p = 0.0007; q = 0.003) while non-perceptual positive symptom severity increased with age (F = 4.1, p = 0.01, q = 0.02). Anhedonia severity increased with increasing age (F = 6.7, p = 0.00035; q = 0.0003), while flat affect decreased in severity with increased age (F = 9.8, p = 0.002; q = 0.006). Findings remained significant when parental SES, IQ, and illness duration were included as covariates. There were no developmental effects on change in positive or negative symptom severity (all p > 0.25). Beginning at age 18, there was a statistically significant association between severity of non-perceptual and perceptual symptoms. This relationship increased in strength throughout adulthood. CONCLUSIONS: These findings suggest that as maturation proceeds, perceptual symptoms attenuate while non-perceptual symptoms are enhanced. Findings underscore how pathological brain-behavior relationships vary as a function of development.

Spacer microbial contamination and asthma outcomes: case series.

OBJECTIVE: The primary method of drug delivery to treat asthma is through pressurized metered dose inhalers (pMDI). Asthma guidelines recommend that providers prescribe a spacer for all patients using pMDI. The objective of this study was to examine whether microbial contamination of spacer devices is associated with poor asthma outcomes. METHODS: This was a cross-sectional, single-center case series of seven pediatric patients with persistent asthma who had previously been prescribed a spacer. Spacers were swabbed with sterile cotton and samples assessed for bacterial/fungal growth. Parents completed a questionnaire including Asthma Control Test (ACT) and asthma control was assessed by an Allergist/Immunologist physician. RESULTS: Two (n = 2) children's parent-completed ACT score indicated poorly controlled asthma and three (n = 3) patients were noted to be poorly controlled by the physician. All but one caregiver reported cleaning the spacer with most reporting (n = 5) that they cleaned their child's spacer monthly and one (n = 1) reporting cleaning it every two weeks. One spacer had detected Candida albicans. There was not a statistically significant association between ACT score and microbial growth (p > 0.05). CONCLUSION: Most spacers in a pediatric sample were not contaminated, despite lack of consistent cleaning, as recommended by spacer manufacturers. Providers and pharmacists should discuss proper cleaning of spacers with caregivers of pediatric patients.

Diversity and composition of pollen loads carried by pollinators are primarily driven by insect traits, not floral community characteristics.

Flowering plants require conspecific pollen to reproduce but they often also receive heterospecific pollen, suggesting that pollinators carry mixed pollen loads. However, little is known about drivers of abundance, diversity or composition of pollen carried by pollinators. Are insect-carried pollen loads shaped by pollinator traits, or do they reflect available floral resources? We quantified pollen on 251 individual bees and 95 flies in a florally diverse community. We scored taxonomic order, sex, body size, hairiness and ecological specialization of pollinators, and recorded composition of available flowers. We used phylogenetically controlled model selection to compare relative influences of pollinator traits and floral resources on abundance, diversity and composition of insect-carried pollen. We tested congruence between composition of pollen loads and available flowers. Pollinator size, specialization and type (female bee, male bee, or fly) described pollen abundance, diversity and composition better than floral diversity. Pollen loads varied widely among insects (10-80,000,000 grains, 1-16 species). Pollen loads of male bees were smaller, but vastly more diverse than those of female bees, and equivalent in size but modestly more diverse than those of flies. Pollen load size and diversity were positively correlated with body size but negatively correlated with insect ecological specialization. These traits also drove variation in taxonomic and phylogenetic composition of insect-carried pollen loads, but composition was only weakly congruent with available floral resources. Qualities of pollinators best predict abundance and diversity of carried pollen indicating that functional composition of pollinator communities may be important to structuring heterospecific pollen transfer among plants.

Managing driving issues after an acquired brain injury: strategies used by health professionals.

BACKGROUND/AIM: The ability to drive safely can be affected by an acquired brain injury. Following acquired brain injury, clients may experience driving disruptions, formal assessment, return to driving or permanent cessation. Health professionals may be involved in formal driving or component skills' assessment and rehabilitation, or interventions for continued community participation. Meeting the needs of clients related to driving remains a challenging area of clinical practice. The aim of this study was to investigate how driving issues are currently managed by acquired brain injury rehabilitation teams. METHOD: This study utilised a qualitative phenomenological approach to gain insight into the approaches undertaken by four rehabilitation teams working with clients post-acquired brain injury. Semi-structured, audiotaped interviews were conducted with 25 participants who had identified driving as part of their role. RESULTS: Health professional participants described three major areas of clinical focus, describing strategies and challenges associated with each. These were as follows: 'Integrating driving goals into rehabilitation' which involved optimising timing and acknowledging the clients' focus on driving while enhancing driving and rehabilitation outcomes; 'Managing emotional responses' which required protecting therapeutic relationships and providing information, as well as responding to more extreme responses; and finally 'Managing unlicensed driving and meeting long-term needs', which participants identified as the most challenging aspect. Strategies involved using set procedures, building on knowledge of the client, supporting the family and exploring alternatives. CONCLUSION: The teams described a range of strategies used to address the challenges related to driving and driving cessation which can be applied to successfully manage this issue in acquired brain injury rehabilitation.

Bridging the gap: improving correspondence between low-field and high-field magnetic resonance images in young people.

Background: Portable low-field-strength magnetic resonance imaging (MRI) systems represent a promising alternative to traditional high-field-strength systems with the potential to make MR technology available at scale in low-resource settings. However, lower image quality and resolution may limit the research and clinical potential of these devices. We tested two super-resolution methods to enhance image quality in a low-field MR system and compared their correspondence with images acquired from a high-field system in a sample of young people. Methods: T1- and T2-weighted structural MR images were obtained from a low-field (64mT) Hyperfine and high-field (3T) Siemens system in N = 70 individuals (mean age = 20.39 years, range 9-26 years). We tested two super-resolution approaches to improve image correspondence between images acquired at high- and low-field: (1) processing via a convolutional neural network ('SynthSR'), and (2) multi-orientation image averaging. We extracted brain region volumes, cortical thickness, and cortical surface area estimates. We used Pearson correlations to test the correspondence between these measures, and Steiger Z tests to compare the difference in correspondence between standard imaging and super-resolution approaches. Results: Single pairs of T1- and T2-weighted images acquired at low field showed high correspondence to high-field-strength images for estimates of total intracranial volume, surface area cortical volume, subcortical volume, and total brain volume (r range = 0.60-0.88). Correspondence was lower for cerebral white matter volume (r = 0.32, p = 0.007, q = 0.009) and non-significant for mean cortical thickness (r = -0.05, p = 0.664, q = 0.664). Processing images with SynthSR yielded significant improvements in correspondence for total brain volume, white matter volume, total surface area, subcortical volume, cortical volume, and total intracranial volume (r range = 0.85-0.97), with the exception of global mean cortical thickness (r = 0.14). An alternative multi-orientation image averaging approach improved correspondence for cerebral white matter and total brain volume. Processing with SynthSR also significantly improved correspondence across widespread regions for estimates of cortical volume, surface area and subcortical volume, as well as within isolated prefrontal and temporal regions for estimates of cortical thickness. Conclusion: Applying super-resolution approaches to low-field imaging improves regional brain volume and surface area accuracy in young people. Finer-scale brain measurements, such as cortical thickness, remain challenging with the limited resolution of low-field systems.

Assessing expert reliability in determining intracranial EEG channel quality and introducing the automated bad channel detection algorithm.

Objective.To evaluate the inter- and intra-rater reliability for the identification of bad channels among neurologists, EEG Technologists, and naïve research personnel, and to compare their performance with the automated bad channel detection (ABCD) algorithm for detecting bad channels.Approach.Six Neurologists, ten EEG Technologists, and six naïve research personnel (22 raters in total) were asked to rate 1440 real intracranial EEG channels as good or bad. Intra- and interrater kappa statistics were calculated for each group. We then compared each group to the ABCD algorithm which uses spectral and temporal domain features to classify channels as good or bad.Main results.Analysis of channel ratings from our participants revealed variable intra-rater reliability within each group, with no significant differences across groups. Inter-rater reliability was moderate among neurologists and EEG Technologists but minimal among naïve participants. Neurologists demonstrated a slightly higher consistency in ratings than EEG Technologists. Both groups occasionally misclassified flat channels as good, and participants generally focused on low-frequency content for their assessments. The ABCD algorithm, in contrast, relied more on high-frequency content. A logistic regression model showed a linear relationship between the algorithm's ratings and user responses for predominantly good channels, but less so for channels rated as bad. Sensitivity and specificity analyses further highlighted differences in rating patterns among the groups, with neurologists showing higher sensitivity and naïve personnel higher specificity.Significance.Our study reveals the bias in human assessments of intracranial electroencephalography (iEEG) data quality and the tendency of even experienced professionals to overlook certain bad channels, highlighting the need for standardized, unbiased methods. The ABCD algorithm, outperforming human raters, suggests the potential of automated solutions for more reliable iEEG interpretation and seizure characterization, offering a reliable approach free from human biases.

The association between cortical gyrification and sleep in adolescents and young adults.

STUDY OBJECTIVES: Healthy sleep is important for adolescent neurodevelopment, and relationships between brain structure and sleep can vary in strength over this maturational window. Although cortical gyrification is increasingly considered a useful index for understanding cognitive and emotional outcomes in adolescence, and sleep is also a strong predictor of such outcomes, we know relatively little about associations between cortical gyrification and sleep. We aimed to identify developmentally invariant (stable across age) or developmentally specific (observed only during discrete age intervals) gyrification-sleep relationships in young people. METHODS: A total of 252 Neuroimaging and Pediatric Sleep Databank participants (9-26 years; 58.3% female) completed wrist actigraphy and a structural MRI scan. Local gyrification index (lGI) was estimated for 34 bilateral brain regions. Naturalistic sleep characteristics (duration, timing, continuity, and regularity) were estimated from wrist actigraphy. Regularized regression for feature selection was used to examine gyrification-sleep relationships. RESULTS: For most brain regions, greater lGI was associated with longer sleep duration, earlier sleep timing, lower variability in sleep regularity, and shorter time awake after sleep onset. lGI in frontoparietal network regions showed associations with sleep patterns that were stable across age. However, in default mode network regions, lGI was only associated with sleep patterns from late childhood through early-to-mid adolescence, a period of vulnerability for mental health disorders. CONCLUSIONS: We detected both developmentally invariant and developmentally specific ties between local gyrification and naturalistic sleep patterns. Default mode network regions may be particularly susceptible to interventions promoting more optimal sleep during childhood and adolescence.

Normative Modeling of Brain Morphometry in Clinical High Risk for Psychosis.

Importance: The lack of robust neuroanatomical markers of psychosis risk has been traditionally attributed to heterogeneity. A complementary hypothesis is that variation in neuroanatomical measures in individuals at psychosis risk may be nested within the range observed in healthy individuals. Objective: To quantify deviations from the normative range of neuroanatomical variation in individuals at clinical high risk for psychosis (CHR-P) and evaluate their overlap with healthy variation and their association with positive symptoms, cognition, and conversion to a psychotic disorder. Design, Setting, and Participants: This case-control study used clinical-, IQ-, and neuroimaging software (FreeSurfer)-derived regional measures of cortical thickness (CT), cortical surface area (SA), and subcortical volume (SV) from 1340 individuals with CHR-P and 1237 healthy individuals pooled from 29 international sites participating in the Enhancing Neuroimaging Genetics Through Meta-analysis (ENIGMA) Clinical High Risk for Psychosis Working Group. Healthy individuals and individuals with CHR-P were matched on age and sex within each recruitment site. Data were analyzed between September 1, 2021, and November 30, 2022. Main Outcomes and Measures: For each regional morphometric measure, deviation scores were computed as z scores indexing the degree of deviation from their normative means from a healthy reference population. Average deviation scores (ADS) were also calculated for regional CT, SA, and SV measures and globally across all measures. Regression analyses quantified the association of deviation scores with clinical severity and cognition, and 2-proportion z tests identified case-control differences in the proportion of individuals with infranormal (z < -1.96) or supranormal (z > 1.96) scores. Results: Among 1340 individuals with CHR-P, 709 (52.91%) were male, and the mean (SD) age was 20.75 (4.74) years. Among 1237 healthy individuals, 684 (55.30%) were male, and the mean (SD) age was 22.32 (4.95) years. Individuals with CHR-P and healthy individuals overlapped in the distributions of the observed values, regional z scores, and all ADS values. For any given region, the proportion of individuals with CHR-P who had infranormal or supranormal values was low (up to 153 individuals [<11.42%]) and similar to that of healthy individuals (<115 individuals [<9.30%]). Individuals with CHR-P who converted to a psychotic disorder had a higher percentage of infranormal values in temporal regions compared with those who did not convert (7.01% vs 1.38%) and healthy individuals (5.10% vs 0.89%). In the CHR-P group, only the ADS SA was associated with positive symptoms (ß = -0.08; 95% CI, -0.13 to -0.02; P = .02 for false discovery rate) and IQ (ß = 0.09; 95% CI, 0.02-0.15; P = .02 for false discovery rate). Conclusions and Relevance: In this case-control study, findings suggest that macroscale neuromorphometric measures may not provide an adequate explanation of psychosis risk.

Increased reliance on world knowledge during language comprehension in healthy aging: evidence from verb-argument prediction.

Cognitive aging negatively impacts language comprehension performance. . However, there is evidence that older adults skillfully use linguistic context and their crystallized world knowledge to offset age-related changes that negatively impact comprehension. Two visual-world paradigm experiments examined how aging changes verb-argument prediction, a comprehension process that relies on world knowledge but has rarely been examined in the cognitive-aging literature. Older adults did not differ from younger adults in their activation of an upcoming likely verb argument, particularly when cued by a semantically-rich agent+verb combination (Experiment 1). However, older adults showed elevated activation of previously-mentioned agents (Experiment 1) and of unlikely but verb-congruent referents (Experiment 2). This is novel evidence that older adults exploit semantic context and world knowledge during comprehension to successfully activate upcoming referents. However, older adults also show elevated activation of irrelevant information, consistent with previous findings demonstrating that older adults may experience greater proactive interference and competition from task-irrelevant information.

Neurobiological Clusters Are Associated With Trajectories of Overall Psychopathology in Youth.

BACKGROUND: Integrating multiple neuroimaging modalities to identify clusters of individuals and then associating these clusters with psychopathology is a promising approach for understanding neurobiological mechanisms that underlie psychopathology and the extent to which these features are associated with clinical symptoms. METHODS: We leveraged neuroimaging data from T1-weighted, diffusion-weighted, and resting-state functional magnetic resonance images from the Adolescent Brain Cognitive Development (ABCD) Study (N = 8035) and used similarity network fusion and spectral clustering to identify subgroups of participants. We examined neuroimaging measures as a function of clustering profiles using 1, 2, or 3 imaging modalities (i.e., data combinations), calculated the stability of the clustering assignment in each respective data combination, and compared the consistency of clusters across different data combinations. We then compared the extent to which clusters were associated with overall psychopathology at the baseline assessment and at 2 yearly follow-up visits. RESULTS: Each data combination resulted in optimal clusters ranging from 2 to 4 subgroups for each data combination. Clusters were stable across subsampling of the ABCD Study cohort. Widespread structural measures (surface area, fractional anisotropy, and mean diffusivity) were important features contributing to clustering across different data combinations. Five of the seven data combinations were associated with overall psychopathology, both at baseline and over time (d = 0.08-0.41). Generally, lower global cortical volume and surface area, widespread reduced fractional anisotropy, and increased radial diffusivity were associated with increased overall psychopathology. CONCLUSIONS: Profiles constructed from neuroimaging data combinations are associated with concurrent and future psychopathology trajectories.

Chiropractic care and research priorities for the pediatric population: a cross-sectional survey of Quebec chiropractors.

BACKGROUND: Chiropractors commonly treat pediatric patients within their private practices. The objectives of this study were (1) to identify the treatment techniques and health advice used by Quebec chiropractors with pediatric patients; (2) to explore the research priorities of Quebec chiropractors for the pediatric population; and (3) to identify Quebec chiropractors' training in the field of pediatric chiropractics. METHODS: A web-based cross-sectional survey was conducted among all licensed Quebec chiropractors (Qc, Canada). Descriptive statistics were used to analyze all quantitative variables. RESULTS: The results showed that among the 245 respondents (22.8% response rate), practitioners adapted their treatment techniques based on their patients' age group, thus using softer techniques with younger pediatric patients and slowly gravitating toward techniques used with adults when patients reached the age of six. In terms of continuing education, chiropractors reported an average of 7.87 h of training on the subject per year, which mostly came from either Quebec's College of Chiropractors (OCQ) (54.7%), written articles (46.9%) or seminars and conferences (43.7%). Both musculoskeletal (MSK) and viscerosomatic conditions were identified as high research priorities by the clinicians. CONCLUSIONS: Quebec chiropractors adapt their treatment techniques to pediatric patients. In light of limited sources of continuing education in the field of pediatric chiropractics, practitioners mostly rely on the training provided by their provincial college and scientific publications. According to practitioners, future research priorities for pediatric care should focus on both MSK conditions and non-MSK conditions.