Use of uniconazole in growth regulation and biochemical changes in maize.

ABSTRACT - The current paper evaluated the incubation time, and doses of Uniconazole (UCZ) applied to maize seeds to verify the plants? response at different phenological stages. MSG1001 hybrid seeds were treated with UCZ (0, 50, and 100 mg.kg-1 of seed) with different incubation times (IT ? 1 min and 12 h). In the lab experiment, the treated seeds were displaced in rolls of the previously moistened Germitest paper and incubated for a week in a BOD chamber at 25ºC with a 12-hour photoperiod. In the greenhouse experiments, sowing was carried out in pots with sand, and supplementary irrigation was applied for ten days. In the field experiment, sowing was performed with 0.5 m spacing between rows in densities of 75,000 and 65,000 plants.ha-1. In the BOD and the greenhouse, the design of both experiments was entirely randomized in a double-factor scheme (IT x UCZ). A randomized block design in a triple-factor scheme (IT x UCZ x Population) was used in the field experiment. Seed treatment with UCZ did not promote germination inhibition. The concentration of 100 mg UCZ kg-1 of seed in the 12-hour IT resulted in a more significant accumulation of root mass in seedlings after one week in the BOD. In the greenhouse, plants in the V1 stage presented longer shoot lengths for the treatments that received UCZ. Incubation time influenced root length, and IT = 12 h at a concentration of 50 mg UCZ kg-1 of seed was more efficient than IT = 1 min. Application of 100 mg UCZ kg-1 of seed was more effective for accumulating chlorophylls A and B in IT = 1 min. In the field, seeds treated with UCZ changed plants for female flowering and the number of green leaves below the ear. The population of 75,000 plants.ha-1 was more productive, with UCZ contributing to the hybrid?s yield. Incubation of the seeds with 50 or 100 mg UCZ kg-1 of seed in IT = 1 min contributed to more productivity than IT = 12 h. The grains? starch content increased with the application of UCZ at a dose of 100 mg kg-1 of seed, and the starch percentage was modified according to population density and incubation time. RESUMO - O presente trabalho teve como objetivo avaliar o tempo de incubação e doses de Uniconazole (UCZ), aplicadas em sementes de milho, visando verificar a resposta das plantas em diferentes estádios fenológicos. Sementes do híbrido MSG1001 foram tratadas com UCZ (0; 50; 100 mg.kg-1 de semente) sob diferentes tempos de incubação (TI ? 1 min e 12 h). No experimento em laboratório, as sementes tratadas foram dispostas em rolos de papel Germitest previamente umedecido, e incubadas por uma semana em BOD a 25ºC com fotoperíodo de 12 h. No experimento conduzido em casa de vegetação a semeadura foi realizada em vasos contendo areia, e irrigação suplementar foi realizada no período de 10 dias. No experimento de campo, a semeadura foi realizada empregando-se espaçamento de 0,5 m entre fileiras nas densidades de 75 e 65 mil plantas. ha-1. O delineamento dos experimentos em BOD e em casa de vegetação foi inteiramente casualizado em esquema fatorial duplo (TI x UCZ). No experimento de campo foi empregado o delineamento de blocos casualizados em esquema fatorial triplo (TI x UCZ x População). O tratamento de sementes com UCZ não promoveu a inibição da germinação. Na concentração de 100 mg UCZ kg-1 de sementes no TI de 12 h resultou em maior acúmulo de massa de raiz em plântulas após uma semana em BOD. Em casa de vegetação, plantas no estádio V1, apresentaram maior comprimento da parte aérea para os tratamentos que receberam UCZ. O tempo de incubação apresentou influência sobre o comprimento radicular sendo que TI = 12 h na concentração de 50 mg UCZ.kg-1 de sementes foi mais eficiente que TI= 1 min. A aplicação de 100 mg UCZ kg-1 de sementes foi mais efetiva para acumulação das clorofilas A e B no TI= 1 min. Em campo, sementes tratadas com UCZ resultaram em alteração em plantas para florescimento feminino e número de folhas verdes abaixo da espiga. População de 75 mil plantas ha-1 foram mais produtivas, com o UCZ contribuindo para o rendimento do híbrido. Incubação das sementes nas concentrações de 50 ou 100 mg UCZ kg-1 semente no TI= 1 mim contribuiu mais para a produtividade do que em TI = 12 h. O teor de amido dos grãos apresentou incremento com a aplicação de UCZ na dose de 100 mg kg-1 de sementes e, a percentagem de amido foi modificada conforme a densidade populacional e o tempo de incubação

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci.

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations

Age-dependent white matter disruptions after military traumatic brain injury: Multivariate analysis results from ENIGMA brain injury

Mild Traumatic brain injury (mTBI) is a signature wound in military personnel, and repetitive mTBI has been linked to age-related neurogenerative disorders that affect white matter (WM) in the brain. However, findings of injury to specific WM tracts have been variable and inconsistent. This may be due to the heterogeneity of mechanisms, etiology, and comorbid disorders related to mTBI. Non-negative matrix factorization (NMF) is a data-driven approach that detects covarying patterns (components) within high-dimensional data. We applied NMF to diffusion imaging data from military Veterans with and without a self-reported TBI history. NMF identified 12 independent components derived from fractional anisotropy (FA) in a large dataset (n = 1,475) gathered through the ENIGMA (Enhancing Neuroimaging Genetics through Meta-Analysis) Military Brain Injury working group. Regressions were used to examine TBI- and mTBI-related associations in NMF-derived components while adjusting for age, sex, post-traumatic stress disorder, depression, and data acquisition site/scanner. We found significantly stronger age-dependent effects of lower FA in Veterans with TBI than Veterans without in four components (q \u3c 0.05), which are spatially unconstrained by traditionally defined WM tracts. One component, occupying the most peripheral location, exhibited significantly stronger age-dependent differences in Veterans with mTBI. We found NMF to be powerful and effective in detecting covarying patterns of FA associated with mTBI by applying standard parametric regression modeling. Our results highlight patterns of WM alteration that are differentially affected by TBI and mTBI in younger compared to older military Veterans

Assessment of brain age in posttraumatic stress disorder: Findings from the ENIGMA PTSD and brain age working groups

Background: Posttraumatic stress disorder (PTSD) is associated with markers of accelerated aging. Estimates of brain age, compared to chronological age, may clarify the effects of PTSD on the brain and may inform treatment approaches targeting the neurobiology of aging in the context of PTSD. Method: Adult subjects (N = 2229; 56.2% male) aged 18–69 years (mean = 35.6, SD = 11.0) from 21 ENIGMA-PGC PTSD sites underwent T1-weighted brain structural magnetic resonance imaging, and PTSD assessment (PTSD+, n = 884). Previously trained voxel-wise (brainageR) and region-of-interest (BARACUS and PHOTON) machine learning pipelines were compared in a subset of control subjects (n = 386). Linear mixed effects models were conducted in the full sample (those with and without PTSD) to examine the effect of PTSD on brain predicted age difference (brain PAD; brain age − chronological age) controlling for chronological age, sex, and scan site. Results: BrainageR most accurately predicted brain age in a subset (n = 386) of controls (brainageR: ICC = 0.71, R = 0.72, MAE = 5.68; PHOTON: ICC = 0.61, R = 0.62, MAE = 6.37; BARACUS: ICC = 0.47, R = 0.64, MAE = 8.80). Using brainageR, a three-way interaction revealed that young males with PTSD exhibited higher brain PAD relative to male controls in young and old age groups; old males with PTSD exhibited lower brain PAD compared to male controls of all ages. Discussion: Differential impact of PTSD on brain PAD in younger versus older males may indicate a critical window when PTSD impacts brain aging, followed by age-related brain changes that are consonant with individuals without PTSD. Future longitudinal research is warranted to understand how PTSD impacts brain aging across the lifespan

Intrusive Traumatic Re-Experiencing Domain (ITRED) – Functional Connectivity Feature Classification by the ENIGMA PTSD Consortium

Background Intrusive Traumatic Re-Experiencing Domain (ITRED) was recently introduced as a novel perspective on posttraumatic psychopathology, proposing to focus research of posttraumatic stress disorder (PTSD) on the unique symptoms of intrusive and involuntary re-experiencing of the trauma, namely, intrusive memories, nightmares, and flashbacks. The aim of the present study was to explore ITRED from a neural network connectivity perspective. Methods Data was collected from nine sites taking part in the ENIGMA-PTSD Consortium (n=584) and included itemized PTSD symptoms scores and resting-state functional connectivity (rsFC) data. We assessed the utility of rsFC in classifying PTSD, ITRED-only (no PTSD diagnosis), and Trauma-exposed (TE)-only (no PTSD or ITRED) groups using a machine learning approach, examining well-known networks implicated in PTSD. Random forest classification model was built on a training set using cross-validation (CV), and the averaged CV model performance for classification was evaluated using area-under-the-curve (AUC). The model was tested using a fully independent portion of the data (test dataset), and the test AUC was evaluated. Results RsFC signatures differentiated TE-only participants from PTSD and from ITRED-only participants at about 60% accuracy. Conversely, rsFC signatures did not differentiate PTSD from ITRED-only individuals (45% accuracy). Common features differentiating TE-only participants from PTSD and from ITRED-only participants mainly involved default mode network-related pathways. Some unique features, such as connectivity within the frontal-parietal network, differentiated TE-only participants from one group (PTSD or ITRED-only), but to a lesser extent from the other. Conclusion Neural network connectivity supports ITRED as a novel neurobiologically-based approach to classifying post-trauma psychopathology