The type b capsular polysaccharide as a virulence determinant of Haemophilus influenzae: studies using clinical isolates and laboratory transformants

Haemophilus influenzae organisms elaborating one of six capsular polysaccharides (types a-f) colonize the respiratory tract of humans, but only type b strains commonly cause systemic infections. To investigate the role of capsular polysaccharides as virulence determinants, rats were inoculated with capsulated (types a-f) or noncapsulated clinical isolates or with laboratory-derived type b and type d transformants of a noncapsulated strain. After intraperitoneal inoculation, all capsulated strains possessed the potential for systemic infection, but type b strains were more virulent; noncapsulated strains were noninvasive. After intranasal inoculation, only type b strains were invasive. There was no difference in efficiency of nasopharyngeal colonization between type b and type d transformants. After intravenous inoculation, only type b strains resulted in persistent bacteremia. Thus, type b strains--clinical isolates or transformants--display unique virulence characteristics. These data suggest that elaboration of type b capsule is necessary and sufficient for this virulence of H. influenzae type b in the rat.

The application of new software tools to quantitative protein profiling via isotope-coded affinity tag (ICAT) and tandem mass spectrometry: II. Evaluation of tandem mass spectrometry methodologies for large-scale protein analysis, and the application of statistical tools for data analysis and interpretation

Proteomic approaches to biological research that will prove the most useful and productive require robust, sensitive, and reproducible technologies for both the qualitative and quantitative analysis of complex protein mixtures. Here we applied the isotope-coded affinity tag (ICAT) approach to quantitative protein profiling, in this case proteins that copurified with lipid raft plasma membrane domains isolated from control and stimulated Jurkat human T cells. With the ICAT approach, cysteine residues of the two related protein isolates were covalently labeled with isotopically normal and heavy versions of the same reagent, respectively. Following proteolytic cleavage of combined labeled proteins, peptides were fractionated by multidimensional chromatography and subsequently analyzed via automated tandem mass spectrometry. Individual tandem mass spectrometry spectra were searched against a human sequence database, and a variety of recently developed, publicly available software applications were used to sort, filter, analyze, and compare the results of two repetitions of the same experiment. In particular, robust statistical modeling algorithms were used to assign measures of confidence to both peptide sequences and the proteins from which they were likely derived, identified via the database searches. We show that by applying such statistical tools to the identification of T cell lipid raft-associated proteins, we were able to estimate the accuracy of peptide and protein identifications made. These tools also allow for determination of the false positive rate as a function of user-defined data filtering parameters, thus giving the user significant control over and information about the final output of large-scale proteomic experiments. With the ability to assign probabilities to all identifications, the need for manual verification of results is substantially reduced, thus making the rapid evaluation of large proteomic datasets possible. Finally, by repeating the experiment, information relating to the general reproducibility and validity of this approach to large-scale proteomic analyses was also obtained.

The application of new software tools to quantitative protein profiling via isotope-coded affinity tag (ICAT) and tandem mass spectrometry: I. Statistically annotated datasets for peptide sequences and proteins identified via the application of ICAT and tandem mass spectrometry to proteins copurifying with T cell lipid rafts

Lipid rafts were prepared according to standard protocols from Jurkat T cells stimulated via T cell receptor/CD28 cross-linking and from control (unstimulated) cells. Co-isolating proteins from the control and stimulated cell preparations were labeled with isotopically normal (d0) and heavy (d8) versions of the same isotope-coded affinity tag (ICAT) reagent, respectively. Samples were combined, proteolyzed, and resultant peptides fractionated via cation exchange chromatography. Cysteine-containing (ICAT-labeled) peptides were recovered via the biotin tag component of the ICAT reagents by avidin-affinity chromatography. On-line micro-capillary liquid chromatography tandem mass spectrometry was performed on both avidin-affinity (ICAT-labeled) and flow-through (unlabeled) fractions. Initial peptide sequence identification was by searching recorded tandem mass spectrometry spectra against a human sequence data base using SEQUEST software. New statistical data modeling algorithms were then applied to the SEQUEST search results. These allowed for discrimination between likely "correct" and "incorrect" peptide assignments, and from these the inferred proteins that they collectively represented, by calculating estimated probabilities that each peptide assignment and subsequent protein identification was a member of the "correct" population. For convenience, the resultant lists of peptide sequences assigned and the proteins to which they corresponded were filtered at an arbitrarily set cut-off of 0.5 (i.e. 50% likely to be "correct") and above and compiled into two separate datasets. In total, these data sets contained 7667 individual peptide identifications, which represented 2669 unique peptide sequences, corresponding to 685 proteins and related protein groups.

Introducing solution-focused approaches to staff in inpatient psychiatric settings

The authors describe several approaches to introducing solution-focused ideas to inpatient psychiatric nursing staff and psychiatric nursing students. The approach is intended to show the basic values of this approach in the process of helping participants become acquainted with concepts central to newer models of brief psychotherapy. The format uses humor, small group experiential case examples along with didactic approaches to facilitate new ways of thinking congruent with new models of therapy.

Beyond the bilingual advantage: The potential role of genes and environment on the development of cognitive control

In recent years there has been considerable debate about the presence or absence of a bilingual advantage in tasks that involve cognitive control. Our previous work has established evidence of differences in brain activity between monolinguals and bilinguals in both word learning and in the avoidance of interference during a picture selection task. Recent models of cognitive control have highlighted the importance of a set of neural structures that may show differential tuning due to exposure to two languages. There is also evidence that genetic factors play a role in the availability of dopamine in neural structures involved in cognitive control. Thus, it is important to investigate whether there are interactions effects generating variability in language acquisition when attributed to genetic (e.g., characteristics of dopamine turnover) and environmental (e.g., exposure to two languages) factors. Here preliminary results from genotyping of a sample of bilingual and monolingual individuals are reported. They reveal different distributions in allele frequencies of the DRD2/ANKK1 taq1A polymorphism. These results bring up the possibility that bilinguals may exhibit additional flexibility due to differences in genetic characteristics relative to monolinguals. Future studies should consider genotype as a possible contributing factor to the development of cognitive control across individuals with different language learning histories.

An ode to fetal, infant, and toddler neuroimaging: Chronicling early clinical to research applications with MRI, and an introduction to an academic society connecting the field

Fetal, infant, and toddler neuroimaging is commonly thought of as a development of modern times (last two decades). Yet, this field mobilized shortly after the discovery and implementation of MRI technology. Here, we provide a review of the parallel advancements in the fields of fetal, infant, and toddler neuroimaging, noting the shifts from clinical to research use, and the ongoing challenges in this fast-growing field. We chronicle the pioneering science of fetal, infant, and toddler neuroimaging, highlighting the early studies that set the stage for modern advances in imaging during this developmental period, and the large-scale multi-site efforts which ultimately led to the explosion of interest in the field today. Lastly, we consider the growing pains of the community and the need for an academic society that bridges expertise in developmental neuroscience, clinical science, as well as computational and biomedical engineering, to ensure special consideration of the vulnerable mother-offspring dyad (especially during pregnancy), data quality, and image processing tools that are created, rather than adapted, for the young brain.

Individual differences in the bilingual brain: The role of language background and DRD2 genotype in verbal and non-verbal cognitive control

Bilingual language control may involve cognitive control, including inhibition and switching. These types of control have been previously associated with neural activity in the inferior frontal gyrus (IFG) and the anterior cingulate cortex (ACC). In previous studies, the DRD2 gene, related to dopamine availability in the striatum, has been found to play a role in neural activity during cognitive control tasks, with carriers of the gene's A1 allele showing different patterns of activity in inferior frontal regions during cognitive control tasks than non-carriers. The current study sought to extend these findings to the domain of bilingual language control. Forty-nine Spanish-English bilinguals participated in this study by providing DNA samples through saliva, completing background questionnaires, and performing a language production task (picture-naming), a non-verbal inhibition task (Simon task), and a non-verbal switching task (shape-color task) in the fMRI scanner. The fMRI data were analyzed to determine whether variation in the genetic background or bilingual language background predicts neural activity in the IFG and ACC during these three tasks. Results indicate that genetic and language background variables predicted neural activity in the IFG during English picture naming. Variation in only the genetic background predicted neural activity in the ACC during the shape-color switching task; variation in only the language background predicted neural activity in the ACC and IFG during the Simon task. These results suggest that variation in the DRD2 gene should not be ignored when drawing conclusions about bilingual verbal and non-verbal cognitive control.

"Doing What I can, but I got no Magic Wand:" A Snapshot of Early Childhood Educator Experiences and Efforts to Ensure Quality During the COVID-19 Pandemic

The COVID-19 pandemic impacted early childhood programs serving infants, toddlers, and preschoolers in dramatic ways. After temporarily closing, many educators quickly adapted their procedures to ensure children's safety as they reopened to provide childcare for essential workers and then the community at large. This manuscript reports on statewide efforts to continue quality improvement initiatives for early childhood programs amidst the COVID-19 pandemic. We first describe the impacts of the COVID-19 pandemic for over 2000 educators-teachers, administrators, and specialists-who completed surveys in the Spring and Fall of 2020. These survey data come from a statewide system called the Texas Early Childhood Professional Development System (TECPDS), designed to track the professional development needs/progress of early childhood educators. Second, we describe an example of how a statewide professional development and quality improvement program shifted to remote delivery during the pandemic. As an increasing number of educators turn to virtual training resources, we explain lessons learned from these response efforts and how they can inform future virtual professional development efforts, even amidst crisis, to ensure that a focus on quality improvement continues while supporting teachers' individual needs.

Lipid raft proteins and their identification in T lymphocytes

This review focuses on how membrane lipid rafts have been detected and isolated, mostly from lymphocytes, and their associated proteins identified. These proteins include transmembrane antigens/receptors, GPI-anchored proteins, cytoskeletal proteins, Src-family protein kinases, G-proteins, and other proteins involved in signal transduction. To further understand the biology of lipid rafts, new methodological approaches are needed to help characterize the raft protein component, and changes that occur in this component as a result of cell perturbation. We describe the application of new proteomic approaches to the identification and quantification of raft proteins in T-lymphocytes. Similar approaches, applied to other model cell systems, will provide valuable new insights into both cellular signal transduction and lipid raft biology.

Symbiosis, Parasitism and Bilingual Cognitive Control: A Neuroemergentist Perspective

Interest in the intersection between bilingualism and cognitive control and accessibility to neuroimaging methods has resulted in numerous studies with a variety of interpretations of the bilingual cognitive advantage. Neurocomputational Emergentism (or Neuroemergentism for short) is a new framework for understanding this relationship between bilingualism and cognitive control. This framework considers Emergence, in which two small elements are recombined in an interactive manner, yielding a non-linear effect. Added to this is the notion that Emergence can be captured in neural systems using computationally inspired models. This review poses that bilingualism and cognitive control, as examined through the Neuroemergentist framework, are interwoven through development and involve the non-linear growth of cognitive processing encompassing brain areas that combine and recombine, in symbiotic and parasitic ways, in order to handle more complex types of processing. The models that have sought to explain the neural substrates of bilingual cognitive differences will be discussed with a reinterpretation of the entire bilingual cognitive advantage within a Neuroemergentist framework incorporating its neural bases. It will conclude by discussing how this new Neuroemergentist approach alters our view of the effects of language experience on cognitive control. Avenues to move beyond the simple notion of a bilingual advantage or lack thereof will be proposed.

Modeling the client's world through brief solution-focused therapy

The shift to a managed care philosophy means that clients with psychiatric needs are likely to have both fewer and briefer inpatient hospitalizations. Identification of focused goals and measurable outcomes may not translate easily into inpatient programs that have been more process oriented or have based definitions of improvement on complete or near-complete remission of the admission diagnosis. In the context of these shifts, nursing's focus on maintaining a safe environment, developing a therapeutic relationship, providing information, and valuing holistic and individualized care may be lost in programs that treat all clients in the same "packaged" programs. This article describes the philosophical assumptions that underlie the brief inpatient program. The next article in this issue describes how solution-focused therapeutic modalities are used in the continuum of care.

A RETROSPECTIVE STUDY OF PATIENT FALLS IN A PSYCHIATRIC HOSPITAL

1. While falls on medical-surgical units are the focus of extensive research, falls on inpatient psychiatric units are an understudied critical event. 2. The purposes of this study were to identify the variables associated with psychiatric patient falls and to use that information to assess risk and, therefore, prevent falls in this population. 3. The psychiatric patient at risk for falling is described as a woman with a prior history of falls; less than 65 years of age; experiencing anxiety and agitation; and receiving a sedative, a tranquilizer, and a laxative. Additionally, this patient is more likely to fall in a community area.

Brief inpatient psychiatric treatment: finding solutions

The shift to a managed care philosophy means that clients with psychiatric needs are likely to have both fewer and briefer inpatient hospitalizations. Identification of focused goals and measurable outcomes may not translate easily into inpatient programs that have been more process oriented or have based definitions of improvement on complete or near-complete remission of the admission diagnosis. In the context of these shifts, nursing's focus on maintaining a safe environment, developing a therapeutic relationship, providing information, and valuing holistic and individualized care may be lost in programs that treat all clients in the same "packaged" programs. The previous article in this issue described the philosophical assumptions that underlie our brief inpatient program. This article describes how solution-focused therapeutic modalities are used in our continuum of care.

Age of acquisition impacts the brain differently depending on neuroanatomical metric

Although researchers generally agree that a certain set of brain areas underlie bilingual language processing, there is discrepancy regarding what effect timing of language acquisition has on these regions. We aimed to investigate the neuroanatomical correlates of age of acquisition (AoA), which has been examined previously, but with inconsistent results, likely influenced by methodological differences across studies. We analyzed gray matter density, volume, and thickness using whole-brain linear models in 334 bilinguals and monolinguals. Neuroanatomical correlates of AoA differed depending on gray matter metric. Relative to early bilinguals, late bilinguals had thicker cortex in language processing and cognitive control regions, and greater density in multiple frontal areas and the right middle temporal and supramarginal gyri. Early bilinguals had greater volume than late bilinguals in the left middle temporal gyrus. Overall, volume was the least sensitive to AoA-related differences. Multiple regions not classically implicated in dual-language processing were also found, which highlights the important role of whole-brain analyses in neuroscience. This is the first study to investigate AoA and gray matter thickness, volume, and density all in the same sample. We conclude that cognitive models of bilingualism should consider the roles of development and neuroanatomical metric in driving our understanding of bilingual and monolingual language organization.

Becoming a balanced, proficient bilingual: Predictions from age of acquisition & genetic background

Genetic variants related to dopamine functioning (e.g., the ANKK1/TaqIa polymorphism within the DRD2 gene and the Val158Met polymorphism within the COMT gene) have previously been shown to predict cognitive flexibility and learning (e.g., Colzato et al., 2010; Stelzel et al., 2010). Additionally, researchers have found that these genetic variants may also predict second language learning (Mamiya et al., 2016), although this relationship may change across the lifespan (Sugiura et al., 2011). The current study examined the role of the ANKK1/TaqIa and Val158Met polymorphisms along with age of second language acquisition (AoA) in order to predict levels of bilingual proficiency in Spanish-English bilinguals. Results indicated a three-way interaction such that the relationship between the genetic variants and bilingual proficiency depended on AoA. At earlier AoAs, having the genetic variant associated with higher levels of subcortical dopamine (A1+) predicted the highest levels of bilingual proficiency. At later AoAs, individuals with the genetic variant associated with cortical dopamine levels that are balanced between stability and flexibility (Val/Met) predicted the highest levels of bilingual proficiency. These results fit with theories about the development of language as a subcortical process early in life and as a cortical process later in life (Hernandez & Li, 2007), as well as the importance of both stability and flexibility in bilingual language development (Green & Abutalebi, 2013). Finally, this study raises questions about the direction of causality between bilingualism and cognitive control, which is central to the debate over the "bilingual advantage."

Anterior insular thickness predicts speech sound learning ability in bilinguals

A previous fMRI study of novel speech sound learning, tied to the methods and results presented here, identified groups of advanced and novice learners and related their classification to neural activity. To complement those results and better elucidate the role of the entire neural system in speech learning, the current study analyzed the neuroanatomical data with the goals of 1) uncovering the regions of interest (ROIs) that predicted speech learning performance in a sample of monolingual and bilingual adults, and 2) examining if the relationship between cortical thickness from selected ROIs and individual learning ability depends on language group. The ROIs selected were brain regions well-established in the literature as areas associated with language and speech processing (i.e., Transverse Superior Temporal Gyrus, anterior insula and posterior insula, all bilaterally). High-resolution brain scans (T1-weighted) were acquired from 23 Spanish-English bilinguals and 20 English monolingual adults. The thickness of the left anterior insula significantly predicted speech sound learning ability in bilinguals but not monolinguals. These results suggest that aptitude for learning a new language is associated with variations in the cortical thickness of the left anterior insula in bilinguals. These findings may provide insight into the higher order mechanisms involved in speech perception and advance our understanding of the unique strategies employed by the bilingual brain during language learning.

Knockdown mortality, repellency, and residual effects of insecticides for control of adult Bactericera cockerelli (Hemiptera: Psyllidae)

The psyllid Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae) is the vector of a bacterial pathogen causing zebra chip (ZC) disease in potato, Solanum tuberosum L. (Solanaceae). Recently, ZC has become important to potato growers and the potato chipping industry in the southwestern United States, Mexico, Central America, and New Zealand. In the current study, we evaluated the knockdown effect of 12 insecticides against adult B. cockerelli, and we examined the effects of treating potato leaves: top side only, bottom side only, or both sides. Within 48 h of exposure, abamectin showed the highest and most consistent rate of adult B. cockerelli mortality and a dosage response to three dosages within labeled field rates. Choice tests conducted in petri dishes, involving untreated potato leaves and leaves treated with abamectin, revealed that abamectin did not affect host preference of adult B. cockerelli. A residual test under field conditions revealed that, although highly effective immediately after application, abamectin-effect was nonsignificantly different from control treatments 24 and 48 h after field application. Higher adult B. cockerelli mortality was recorded from potato plants treated with ground application compared with aerial 48 h after application. Our results indicated that abamectin has a high knockdown effect on adult B. cockerelli and that it can be used effectively in insecticide rotation programs against adult B. cockerelli and ZC control in potatoes.

Prefrontal transcranial direct current stimulation (tDCS) has a domain-specific impact on bilingual language control

Researchers debate whether domain-general cognitive control supports bilingual language control through brain regions such as the dorsolateral prefrontal cortex (DLPFC). Transcranial direct current stimulation (tDCS) is a method to alter brain activity, which can lead to causal attribution of task performance to regional brain activity. The current study examined whether the DLPFC enables domain-general control for between-language switching and nonlinguistic switching and whether the control enabled by DLPFC differs between bilinguals and monolinguals. tDCS was applied to the DLPFC of bilingual and monolingual young adults before they performed linguistic and nonlinguistic switching measures. For bilinguals, left DLPFC stimulation selectively worsened nonlinguistic switching, but not within-language switching. Left DLPFC stimulation also resulted in higher overall accuracy on bilingual picture-naming. These findings suggest that language control and cognitive control are distinct processes in relation to the left DLPFC. The left DLPFC may aid bilingual language control, but stimulating it does not benefit nonlinguistic control. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cortical Thickness in bilingual and monolingual children: Relationships to language use and language skill

There is a growing body of evidence based on adult neuroimaging that suggests that the brain adapts to bilingual experiences to support language proficiency. The Adolescent Brain Cognitive Development (ABCD) Study is a useful source of data for evaluating this claim during childhood, as it involves data from a large sample of American children. Using the baseline ABCD Study data collected at ages nine and ten, the goal of this study was to identify differences in cortical thickness between bilinguals and monolinguals and to evaluate how variability in English vocabulary and English use within bilinguals might explain these group differences. We identified bilingual participants as children who spoke a non-English language and were exposed to the non-English language at home. We then identified a matched sample of English monolingual participants based on age, sex, pubertal status, parent education, household income, non-verbal IQ, and handedness. Bilinguals had thinner cortex than monolinguals in widespread cortical regions. Within bilinguals, more English use was associated with greater frontal and parietal cortical thickness; greater English vocabulary was associated with greater frontal and temporal cortical thickness. These findings replicate and extend previous research with bilingual children and highlight unexplained cortical thickness differences between bilinguals and monolinguals.

Highly proficient, balanced bilingualism is related to thinner cortex in two cognitive control regions

Whereas some bilinguals have one language that is dominant, others attain high proficiency in both languages. This variation is likely explained by a combination of environmental and genetic factors; however, there is a lapse in research on the neural underpinnings of bilingual proficiency. No study to date has examined how highly proficient bilingualism that is balanced relates to brain morphology in adults. Our present study analyzed the brains of 200 Spanish-English bilingual adults. Bilingual proficiency was measured and weighted by the degree of balance across the two languages. It was found that having higher dual language proficiency was related to thinner cortex in two regions: the left anterior prefrontal cortex (PFC) and the right anterior cingulate cortex (ACC). Neither English nor Spanish proficiency alone could account for neuroanatomical differences. Our findings suggest that thinner cortex of the left anterior PFC and the right ACC in adults with highly proficient, balanced bilingualism is how the adult brain reflects a lifetime of learning to flexibly adapt and utilize both languages and suggests the involvement of these structures in maintaining and increasing dual language proficiency.

Functional neuroimaging of sensorimotor cortices in postmenopausal women with type II diabetes

Significance: Deficits in sensorimotor function in persons with type II diabetes mellitus (PwDM) have traditionally been considered a result of peripheral nerve damage. Emerging evidence has suggested that factors outside of nerve damage due to type II diabetes mellitus, such as impaired hemodynamic function, contribute significantly to both sensory and motor deficits in PwDM. Aim: The focus of the current study was to evaluate functional cortical hemodynamic activity during sensory and motor tasks in PwDM. Approach: Functional near-infrared spectroscopy was used to monitor oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) across the cortex during sensory and motor tasks involving the hands. Results: Decline in HbO across sensory and motor regions of interest was found in PwDM with simultaneous deficits in manual motor tasks, providing the first evidence of functional cortical hemodynamic activity deficits relating to motor dysfunction in PwDM. Similar deficits were neither specifically noted in HbR nor during evaluation of sensory function. Health state indices, such asA 1 c , blood pressure, body mass index, and cholesterol, were found to clarify group effects. Conclusions: Further work is needed to clarify potential sex-based differences in PwDM during motor tasks as well as the root of reduced cortical HbO indices but unchanged HbR indices in PwDM.

An Opportunity to Increase Collaborative Science in Fetal, Infant, and Toddler Neuroimaging

The field of fetal, infant, and toddler (FIT) neuroimaging research—including magnetic resonance imaging (MRI), electroencephalography (EEG), magnetoencephalography, and functional near-infrared spectroscopy, among others—offers pioneering insights into early brain development and has grown in popularity over the past 2 decades. In broader neuroimaging research, multisite collaborative projects, data sharing, and open-source code have increasingly become the norm, fostering big data, consensus standards, and rapid knowledge transfer and development. Given the aforementioned benefits, along with recent initiatives from funding agencies to support multisite and multimodal FIT neuroimaging studies, the FIT field now has the opportunity to establish sustainable, collaborative, and open science practices. By combining data and resources, we can tackle the most pressing issues of the FIT field, including small effect sizes, replicability problems, generalizability issues, and the lack of field standards for data collection, processing, and analysis—together. Thus, the goals of this commentary are to highlight some of the potential barriers that have waylaid these efforts and to discuss the emerging solutions that have the potential to revolutionize how we work together to study the developing brain early in life.

Effective connectivity in the default mode network after paediatric traumatic brain injury

Children who experience a traumatic brain injury (TBI) are at elevated risk for a range of negative cognitive and neuropsychological outcomes. Identifying which children are at greatest risk for negative outcomes can be difficult due to the heterogeneity of TBI. To address this barrier, the current study applied a novel method of characterizing brain connectivity networks, Bayesian multi-subject vector autoregressive modelling (BVAR-connect), which used white matter integrity as priors to evaluate effective connectivity-the time-dependent relationship in functional magnetic resonance imaging (fMRI) activity between two brain regions-within the default mode network (DMN). In a prospective longitudinal study, children ages 8-15 years with mild to severe TBI underwent diffusion tensor imaging and resting state fMRI 7 weeks after injury; post-concussion and anxiety symptoms were assessed 7 months after injury. The goals of this study were to (1) characterize differences in positive effective connectivity of resting-state DMN circuitry between healthy controls and children with TBI, (2) determine if severity of TBI was associated with differences in DMN connectivity and (3) evaluate whether patterns of DMN effective connectivity predicted persistent post-concussion symptoms and anxiety. Healthy controls had unique positive connectivity that mostly emerged from the inferior temporal lobes. In contrast, children with TBI had unique effective connectivity among orbitofrontal and parietal regions. These positive orbitofrontal-parietal DMN effective connectivity patterns also differed by TBI severity and were associated with persisting behavioural outcomes. Effective connectivity may be a sensitive neuroimaging marker of TBI severity as well as a predictor of chronic post-concussion symptoms and anxiety.