We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Background: Attitudes toward aging influence many health outcomes, yet their relationship with cognition and Alzheimer’s disease (AD) remains unknown. To better understand their impact on cognition and AD risk, we examined whether positive attitudes predict better cognition and diminished risk on AD biomarkers. Methods: A subsample of older adults with a family history of AD (n=54; women=39) from the McGill PREVENT-AD cohort participated in this study. Participants completed the Attitudes to Ageing Questionnaire (AAQ-24), providing three scores: psychosocial loss, psychological growth and physical change. Participants underwent cognitive testing (Rey Auditory Verbal Learning Test, RAVLT; Delis-Kaplan Executive Function System-Color Word Interference Test, D-KEFS-CWIT), and AD blood-based biomarker assessments (p-tau217, Aβ42/40). Regression models tested associations, adjusting for covariates (age, sex, education, depression, APOE4), and were Bonferroni corrected. Results: Positive attitudes were associated with better recall and recognition (RAVLT) and improved word reading, colour naming, switching, and inhibition (D-KEFS-CWIT) (p<0.00077), while negative attitudes showed the opposite pattern. Negative attitudes were correlated with lower Aβ42/40 ratios, while positive attitudes were linked to lower p-tau217 (p<0.0167). Conclusions: These findings demonstrate that positive attitudes predict better cognition and a lower risk profile for AD biomarkers, suggesting that life outlook may be an early disease feature or a risk factor.
Threat sensitivity, an individual difference construct reflecting variation in responsiveness to threats of various types, predicts physiological reactivity to aversive stimuli and shares heritable variance with anxiety disorders in adults. However, no research has been conducted yet with youth to examine the heritability of threat sensitivity or evaluate the role of genetic versus environmental influences in its relations with mental health problems. The current study addressed this gap by evaluating the psychometric properties of a measure of this construct, the 20-item Trait Fear scale (TF-20), and examining its phenotypic and genotypic correlations with different forms of psychopathology in a sample of 346 twin pairs (121 monozygotic), aged 9–14 years. Analyses revealed high internal consistency and test-retest reliability for the TF-20. Evidence was also found for its convergent and discriminant validity in terms of phenotypic and genotypic correlations with measures of fear-related psychopathology. By contrast, the TF-20’s associations with depressive conditions were largely attributable to environmental influences. Extending prior work with adults, current study findings provide support for threat sensitivity as a genetically-influenced liability for phobic fear disorders in youth.
Stochastic actor-oriented models (SAOMs) were designed in the social network setting to capture network dynamics representing a variety of influences on network change. The standard framework assumes the observed networks are free of false positive and false negative edges, which may be an unrealistic assumption. We propose a hidden Markov model (HMM) extension to these models, consisting of two components: 1) a latent model, which assumes that the unobserved, true networks evolve according to a Markov process as they do in the SAOM framework; and 2) a measurement model, which describes the conditional distribution of the observed networks given the true networks. An expectation-maximization algorithm is developed for parameter estimation. We address the computational challenge posed by a massive discrete state space, of a size exponentially increasing in the number of vertices, through the use of the missing information principle and particle filtering. We present results from a simulation study, demonstrating our approach offers improvement in accuracy of estimation, in contrast to the standard SAOM, when the underlying networks are observed with noise. We apply our method to functional brain networks inferred from electroencephalogram data, revealing larger effect sizes when compared to the naive approach of fitting the standard SAOM.
Guided by concepts from life history (LH) theory, a large human research literature has tested the hypothesis that exposures to extrinsic mortality (EM) promote the development of faster LH strategies (e.g., earlier/faster reproduction, higher offspring number). A competing model proposes that, because EM in the past was intimately linked to energetic constraints, such exposures specifically led to the development of slower LH strategies. We empirically address this debate by examining (1) LH variation among small-scale societies under different environmental conditions; (2) country-, regional- and community-level correlations between ecological conditions, mortality, maturational timing, and fertility; (3) individual-level correlations between this same set of factors; and (4) natural experiments leveraging the impact of externally-caused changes in mortality on LH traits. Partially supporting each model, we found that harsh conditions encompassing energetic stress and ambient cues to EM (external cues received through sensory systems) have countervailing effects on the development of LH strategies, both delaying pubertal maturation and promoting an accelerated pace of reproduction and higher offspring number. We conclude that, although energetics are fundamental to many developmental processes, providing a first tier of environmental influence, this first tier alone cannot explain these countervailing effects. An important second tier of environmental influence is afforded by ambient cues to EM. We advance a 2-tiered model that delineates this second tier and its central role in regulating development of LH strategies. Consideration of the first and second tier together is necessary to account for the observed countervailing shifts toward both slower and faster LH traits.
Palmer amaranth (Amaranthus palmeri S. Watson, AMAPA) is one of the most troublesome weeds in North America due to its rapid growth rate, substantial seed production, competitiveness and the evolution of herbicide-resistant populations. Though frequently encountered in the South, Midwest, and Mid-Atlantic regions of the United States, A. palmeri was recently identified in soybean [Glycine max (L.) Merr.] fields in Genesee, Orange, and Steuben counties, NY, where glyphosate was the primary herbicide for in-crop weed control. This research, conducted in 2023, aimed to (1) describe the dose response of three putative resistant NY A. palmeri populations to glyphosate, (2) determine their mechanisms of resistance, and (3) assess their sensitivity to other postemergence herbicides commonly used in NY crop production systems. Based on the effective dose necessary to reduce aboveground biomass by 50% (ED50), the NY populations were 42 to 67 times more resistant to glyphosate compared with a glyphosate-susceptible population. Additionally, the NY populations had elevated EPSPS gene copy numbers ranging from 25 to 135 located within extrachromosomal circular DNA (eccDNA). Label rate applications of Weed Science Society of America (WSSA) Group 2 herbicides killed up to 42% of the NY populations of A. palmeri. Some variability was observed among populations in response to WSSA Group 5 and 27 herbicides. All populations were effectively controlled by labeled rates of herbicides belonging to WSSA Groups 4, 10, 14, and 22. Additional research is warranted to confirm whether NY populations have evolved multiple resistance to herbicides within other WSSA groups and to develop effective A. palmeri management strategies suitable for NY crop production.
Patients with progressive neurologic illness still lack access to quality palliative care services. Barriers to the comprehensive provision of neuropalliative care include gaps in palliative care education. To address this barrier, a novel international model of neuropalliative care education e-learning program was launched in 2022.
Methods
This is a qualitative study on the self-reported learning outcomes and educational gains of participants of a neuropalliative care e-learning course.
Results
Thematic analysis shows changes in the participants’ perceptions of neuropalliative care and several specific educational gains. After attending the course, participants recognized neuropalliative care as a multiprofessional and interdisciplinary effort requiring more than medical knowledge and disease-specific treatment skills. They gained understanding of the complexity of prognosis in neurological diseases, as well as ethical concepts as the basis to approach difficult decisions. Valuing the needs of patients and caregivers, as well as honest and open communication were recognized as key components of the caring process. In particular, providing emotional support and building relationships to enhance the spiritual component of care were avidly discussed as essential nonmedical treatment options.
Significance of results
E-learning courses are helping to close the gaps in healthcare professionals’ knowledge and skills about neuropalliative care.
Background: Near-infrared spectroscopy regional cerebral oxygen saturation (rSO2) has gained interest as a raw parameter and as a basis for measuring cerebrovascular reactivity (CVR). This study aimed to identify threshold values of rSO2 and rSO2 based CVR at which outcomes worsened following traumatic brain injury (TBI). Methods: A retrospective multi-institutional cohort study was performed. The cerebral oxygen indices, COx (using rSO2 and cerebral perfusion pressure) as well as COx_a (using rSO2 and arterial blood pressure) were calculated for each patient. 2x2 tables were created grouping patients by alive/dead and favorable/unfavorable outcomes at various thresholds of COx and COx_a as well as rSO2 itself. Chi-square values were calculated to identify the most discriminative significant threshold. Results: In the cohort of 129 patients rSO2 did not have any statistically significant threshold value. For COx and COx_a, an optimal threshold value of 0.2 was identified for both survival and favorable outcomes with values above this associated with worse outcomes. Conclusions: In this study, raw rSO2was found to contain no significant prognostic information. However, rSO2 based indices of CVR, were found to have a uniform threshold of 0.2, above which clinical outcomes worsened. This study lays the groundwork to transition to less invasive means of continuously measuring CVR.
Although the link between alcohol involvement and behavioral phenotypes (e.g. impulsivity, negative affect, executive function [EF]) is well-established, the directionality of these associations, specificity to stages of alcohol involvement, and extent of shared genetic liability remain unclear. We estimate longitudinal associations between transitions among alcohol milestones, behavioral phenotypes, and indices of genetic risk.
Methods
Data came from the Collaborative Study on the Genetics of Alcoholism (n = 3681; ages 11–36). Alcohol transitions (first: drink, intoxication, alcohol use disorder [AUD] symptom, AUD diagnosis), internalizing, and externalizing phenotypes came from the Semi-Structured Assessment for the Genetics of Alcoholism. EF was measured with the Tower of London and Visual Span Tasks. Polygenic scores (PGS) were computed for alcohol-related and behavioral phenotypes. Cox models estimated associations among PGS, behavior, and alcohol milestones.
Results
Externalizing phenotypes (e.g. conduct disorder symptoms) were associated with future initiation and drinking problems (hazard ratio (HR)⩾1.16). Internalizing (e.g. social anxiety) was associated with hazards for progression from first drink to severe AUD (HR⩾1.55). Initiation and AUD were associated with increased hazards for later depressive symptoms and suicidal ideation (HR⩾1.38), and initiation was associated with increased hazards for future conduct symptoms (HR = 1.60). EF was not associated with alcohol transitions. Drinks per week PGS was linked with increased hazards for alcohol transitions (HR⩾1.06). Problematic alcohol use PGS increased hazards for suicidal ideation (HR = 1.20).
Conclusions
Behavioral markers of addiction vulnerability precede and follow alcohol transitions, highlighting dynamic, bidirectional relationships between behavior and emerging addiction.
In this paper, we explore how critically important ecosystems on the land provide evaporation to the atmosphere, which will later fall as precipitation elsewhere. Using a model-based analysis that tracks water flowing through the atmosphere, we find that more than two-thirds of the precipitation over critically important ecosystem areas is supplied by evaporation from other land. Likewise, more than 40% of the evaporation from critically important ecosystems falls as precipitation on other land. We conclude our work by discussing the policy implications for how these critically important ecosystems connect spatially distant wild and working lands via the atmospheric water cycle.
Technical summary
Global ecosystems are interconnected via atmospheric water vapor flows. Land use change can modify evaporation from land, altering atmospheric moisture recycling and potentially leading to significant changes in downwind precipitation and associated ecological impacts. We combine insights on global ecosystem-regulated moisture recycling with an analysis of critical natural assets (CNA, the 30% of global land providing most of nature's contributions to people) to reveal the sources and sinks of atmospheric water cycle regulation. We find that 65% of the precipitation over CNA is supplied by evaporation from other land areas. Likewise, CNA regions supply critical moisture as precipitation to terrestrial natural ecosystems and production systems worldwide, with 44% of CNA evaporation falling on terrestrial surfaces. Specifically, the Congo River basin emerges as a hotspot of overlap between local atmospheric water cycle maintenance and concentration of nature's contributions to people. Our results suggest global priority areas for conservation efforts beyond and in support of CNA, emphasizing the importance of sparsely populated managed forests and rangelands, along with wild forests, for fostering moisture recycling to and within CNA. This work also underlines the manifold benefits associated with achieving United Nations Sustainable Development Goal #15, to sustainably manage terrestrial life and conserve biodiversity.
Social media summary
Critically important ecosystems are essential for connecting distant landscapes via the atmospheric water cycle.
The Maser Monitoring Parkes Project (M2P2) is an ongoing project to observe masers towards high-mass star-forming regions (HMSFRs) using the 64 m CSIRO Parkes radio telescope, Murriyang. In this paper, we outline the project and introduce Stokes-I data from the first two years of observations. For the 63 sightlines observed in this project we identify a total of 1 514 individual maser features: 14.4% of these (203) towards 27 sightlines show significant variability. Most of these (160/203) are seen in the main-line transitions of OH at 1665 and 1667 MHz, but this data set also includes a significant number of variable features in the satellite lines at 1 612 and 1 720 MHz (33 and 10, respectively), most of which (24 and 9, respectively) appear to be associated with the HMSFRs. We divide these features into 4 broad categories based on the behaviour of their intensity over time: flares (6%), periodic (11%), long-term trends (33%), and ‘other’ (50%). Variable masers provide a unique laboratory for the modelling of local environmental conditions of HMSFRs, and follow-up publications will delve into this in more detail.
Poor cardiovascular health occurs with age and is associated with increased dementia risk, yet its impact on frontotemporal lobar degeneration (FTLD) and autosomal dominant neurodegenerative disease has not been well established. Examining cardiovascular risk in a population with high genetic vulnerability provides an opportunity to assess the impact of lifestyle factors on brain health outcomes. In the current study, we examined whether systemic vascular burden associates with accelerated cognitive and brain aging outcomes in genetic FTLD.
Participants and Methods:
166 adults with autosomal dominant FTLD (C9orf72 n= 97; GRN n= 34; MAPT n= 35; 54% female; Mage = 47.9; Meducation = 15.6 years) enrolled in the Advancing Research and Treatment for Frontotemporal Lobar Degeneration (ARTFL) and Longitudinal Evaluation of Familial Frontotemporal Dementia Longitudinal FTD study (ALLFTD) were included. Participants completed neuroimaging and were screened for cardiovascular risk and functional impairment during a comprehensive neurobehavioral and medical interview. A vascular burden score (VBS) was created by summing vascular risk factors (VRS) [diabetes, hypertension, hyperlipidemia, and sleep apnea] and vascular diseases (VDS) [cerebrovascular disease (e.g., TIA, CVA), cardiac arrhythmia (e.g., atrial fibrillation, pacemaker, defibrillator), coronary artery disease (e.g., myocardial infarction, cardiac bypass, stent), and congestive heart failure] following a previously developed composite (range 0 to 8). We examined the interaction between each vascular health metric (VBS, VDS, VRS) and age (vascular health*age) on clinical severity (CDR plus NACC FTLD-SB), and white matter hyperintensity (WMH) volume outcomes, adjusting for age and sex. Vascular risk, disease, and overall burden scores were examined in separate models.
Results:
There was a statistically significant interaction between total VBS and age on both clinical severity (ß=0.20, p=0.044) and WMH burden (ß=0.20, p=0.032). Mutation carriers with higher vascular burden evidenced worse clinical and WMH outcomes for their age. When breaking down the vascular burden score into (separate) vascular risk (VRS) and vascular disease (VDS) scores, the interaction between age and VRS remained significant only for WMH (ß=0.26, p=0.009), but not clinical severity (ß=0.04, p=0.685). On the other hand, the interaction between VDS and age remained significant only for clinical severity (ß=0.20, p=0.041) but not WMH (ß=0.17, p=0.066).
Conclusions:
Our results demonstrate that systemic vascular burden is associated with an “accelerated aging” pattern on clinical and white matter outcomes in autosomal dominant FTLD. Specifically, mutation carriers with greater vascular burden show poorer neurobehavioral outcomes for their chronological age. When separating vascular risk from disease, risk was associated with higher age-related WMH burden, whereas disease was associated with poorer age-related clinical severity of mutation carriers. This pattern suggests preferential brain-related effects of vascular risk factors, while the functional impact of such factors may be more closely aligned with fulminant vascular disease. Our results suggest cardiovascular health may be an important, potentially modifiable risk factor to help mitigate the cognitive and behavioral disturbances associated with having a pathogenic variant of autosomal dominant FTLD. Future studies should continue to examine the neuropathological processes underlying the impact of cardiovascular risk in FTLD to inform more precise recommendations, particularly as it relates to lifestyle interventions.
Therapeutics targeting frontotemporal dementia (FTD) are entering clinical trials. There are challenges to conducting these studies, including the relative rarity of the disease. Remote assessment tools could increase access to clinical research and pave the way for decentralized clinical trials. We developed the ALLFTD Mobile App, a smartphone application that includes assessments of cognition, speech/language, and motor functioning. The objectives were to determine the feasibility and acceptability of collecting remote smartphone data in a multicenter FTD research study and evaluate the reliability and validity of the smartphone cognitive and motor measures.
Participants and Methods:
A diagnostically mixed sample of 207 participants with FTD or from familial FTD kindreds (CDR®+NACC-FTLD=0 [n=91]; CDR®+NACC-FTLD=0.5 [n=39]; CDR®+NACC-FTLD>1 [n=39]; unknown [n=38]) were asked to remotely complete a battery of tests on their smartphones three times over two weeks. Measures included five executive functioning (EF) tests, an adaptive memory test, and participant experience surveys. A subset completed smartphone tests of balance at home (n=31) and a finger tapping test (FTT) in the clinic (n=11). We analyzed adherence (percentage of available measures that were completed) and user experience. We evaluated Spearman-Brown split-half reliability (100 iterations) using the first available assessment for each participant. We assessed test-retest reliability across all available assessments by estimating intraclass correlation coefficients (ICC). To investigate construct validity, we fit regression models testing the association of the smartphone measures with gold-standard neuropsychological outcomes (UDS3-EF composite [Staffaroni et al., 2021], CVLT3-Brief Form [CVLT3-BF] Immediate Recall, mechanical FTT), measures of disease severity (CDR®+NACC-FTLD Box Score & Progressive Supranuclear Palsy Rating Scale [PSPRS]), and regional gray matter volumes (cognitive tests only).
Results:
Participants completed 70% of tasks. Most reported that the instructions were understandable (93%), considered the time commitment acceptable (97%), and were willing to complete additional assessments (98%). Split-half reliability was excellent for the executive functioning (r’s=0.93-0.99) and good for the memory test (r=0.78). Test-retest reliabilities ranged from acceptable to excellent for cognitive tasks (ICC: 0.70-0.96) and were excellent for the balance (ICC=0.97) and good for FTT (ICC=0.89). Smartphone EF measures were strongly associated with the UDS3-EF composite (ß's=0.6-0.8, all p<.001), and the memory test was strongly correlated with total immediate recall on the CVLT3-BF (ß=0.7, p<.001). Smartphone FTT was associated with mechanical FTT (ß=0.9, p=.02), and greater acceleration on the balance test was associated with more motor features (ß=0.6, p=0.02). Worse performance on all cognitive tests was associated with greater disease severity (ß's=0.5-0.7, all p<.001). Poorer performance on the smartphone EF tasks was associated with smaller frontoparietal/subcortical volume (ß's=0.4-0.6, all p<.015) and worse memory scores with smaller hippocampal volume (ß=0.5, p<.001).
Conclusions:
These results suggest remote digital data collection of cognitive and motor functioning in FTD research is feasible and acceptable. These findings also support the reliability and validity of unsupervised ALLFTD Mobile App cognitive tests and provide preliminary support for the motor measures, although further study in larger samples is required.
A common assumption in clinical neuropsychology is that cerebrovascular risk is adversely associated with executive function, while Alzheimer’s disease (AD) primarily targets episodic memory. The goal of the present study was to determine the cross-sectional and longitudinal validity of these assumptions using validated markers of cerebrovascular and AD burden.
Participants and Methods:
19271 longitudinally-followed participants from the National Alzheimer Coordinating Center (NACC) database (Mean age= 72.25; SD age= 10.42; 58% women; 51.6% CDR= 0, 33.7% CDR= 0.5, 14.7% CDR> 1) were included. Cognitive outcomes were a composite memory score and an executive function composite score (UDS3-EF; Staffaroni et al., 2020). Baseline presence of cerebrovascular disease was indexed by the presence of moderate to severe white matter hyperintensities or lacunar infarct on brain MRI (yes/no), while baseline AD pathology was indexed by the presence of a positive amyloid PET scan or elevated CSF AD biomarkers (yes/no). We used linear mixed effect models to assess the effects of baseline cerebrovascular disease, baseline AD pathology, and their interactions with time in study (years post baseline) controlling for baseline age, sex, education, and baseline MoCA score.
Results:
Baseline cerebrovascular disease was significantly associated with a lower intercept on executive functioning (between-person effect) (p < -0.001, 95% CI -0.37, -0.14) but not memory, while presence of AD biomarkers was associated with a lower memory intercept (p < -0.001, 95% CI -0.52, -0.39) but not executive function. However, only presence of AD pathology at baseline was associated with faster longitudinal decline on both memory and executive functioning over time. Baseline cerebrovascular disease did not independently relate to rate of cognitive decline.
Conclusions:
Consistent with widely held assumptions, our between-person analyses showed that MRI evidence of cerebrovascular disease was associated with worse executive functioning but not memory, while biomarker evidence of AD pathology was associated with worse memory but not executive function. Longitudinally, however, AD is the primary driver of decline in both executive and memory function. These results extend our understanding of how pathology impacts cognition in aging cohorts and highlight the importance of using longitudinal models.
Tissue inhibitor of metalloproteinases 2 (TIMP2) is produced peripherally, crosses the blood-brain barrier, and improves synaptic plasticity and hippocampal-dependent cognition in aged mice; however, the role of TIMP2 in human cognitive aging is unclear. We examined associations of circulating TIMP2 levels in blood with a known plasticity-inducing behavior, physical activity, and cognitive functioning among older adults along the Alzheimer’s disease continuum.
Participants and Methods:
Participants included 84 community-dwelling older adults (meanage = 78.8; 57% female; 82% cognitively normal; 14% MCI; 4% mild dementia; 35% PET Aß+) enrolled in the UC San Francisco Memory and Aging Center. All participants completed 30 days of observational FitbitTM monitoring to quantify physical activity (average daily steps), as well as a comprehensive in-person visit including blood draw (proteins assayed on SOMAscan platform), [18F]AV-45 positron emission tomography (PET) to quantify brain beta-amyloid (centiloids), and neuropsychological assessment. Composite cognitive z-scores were calculated for memory (California Verbal Learning Test-II [CVLT-II] and Benson Figure Recall), semantic processing (animal fluency and Boston Naming Test), and executive functioning (digits backwards span, Stroop inhibition, modified trail making test, lexical fluency, and design fluency). Multiple linear regression examined TIMP2 as a function of physical activity, covarying for age and PET centiloids. Additional regression models separately examined cognitive z-scores as a function of TIMP2, covarying for age, sex, education, PET centiloids, and body mass index (BMI).
Results:
TIMP2 was not significantly correlated with age, sex, education, or PET centiloids (ps > 0.05); however, TIMP2 was negatively correlated with BMI (r = -0.23, p = 0.036). Greater average daily steps related to higher levels of TIMP2 (b = 0.30, 95%CI = 0.04-0.55, p = 0.022). TIMP2 also related to better semantic processing (b = 0.28, 95%CI = 0.04-0.51, p = 0.021) and executive functioning (b = 0.26, 95%CI = 0.03-0.49, p = 0.028). TIMP2 did not significantly relate to memory (p > 0.05).
Conclusions:
Greater physical activity was associated with higher concentrations of blood factor TIMP2, which in turn related to better cognitive functioning independent of Alzheimer’s disease pathology burden. These results support previous mouse models by broadly replicating relationships between TIMP2 and cognition in humans, while also uniquely demonstrating an association between TIMP2 and physical activity, a modifiable protective factor in both typical and diseased cognitive aging. Our domain-specific results, however, suggest that benefits of TIMP2 in humans may involve a broader neuroanatomical network than the hippocampal-specific effects previously shown in mice. Although exact mechanisms of TIMP2 need further examination, TIMP2 is known to be enriched in human umbilical cord plasma, has been shown to be involved in cell-growth promoting activities, and may relate to increased neural plasticity in older age. Further examination of TIMP2 and other novel blood-based proteins as potential therapeutic targets for improved cognitive aging, including in the presence of Alzheimer’s disease, is warranted.
Traumatic brain injury (TBI) and concussion are associated with increased dementia risk. Accurate TBI/concussion exposure estimates are relatively unknown for less common neurodegenerative conditions like frontotemporal dementia (FTD). We evaluated lifetime TBI and concussion frequency in patients diagnosed with a range of FTD spectrum conditions and related prior head trauma to cavum septum pellucidum (CSP) characteristics observable on MRI.
Participants and Methods:
We administered the Ohio State University TBI Identification and Boston University Head Impact Exposure Assessment to 108 patients (age 69.5 ± 8.0, 35% female, 93% white or unknown race) diagnosed at the UCSF Memory and Aging Center with one of the following FTD or related conditions: behavioral variant frontotemporal dementia (N=39), semantic variant primary progressive aphasia (N=16), nonfluent variant PPA (N=23), corticobasal syndrome (N=14), or progressive supranuclear palsy (N=16). Data were also obtained from 217 controls (“HC”; age 76.8 ± 8.0, 53% female, 91% white or unknown race). CSP characteristics were defined based on width or “grade” (0-1 vs. 2+) and length of anterior-posterior separation (millimeters). We first describe frequency of any and multiple (2+) prior TBI based on different but commonly used definitions: TBI with loss of consciousness (LOC), TBI with LOC or posttraumatic amnesia (LOC/PTA), TBI with LOC/PTA or other symptoms like dizziness, nausea, “seeing stars,” etc. (“concussion”). TBI/concussion frequency was then compared between FTD and HC using chi-square. Associations between TBI/concussion and CSP characteristics were analyzed with chi-square (CSP grade) and Mann-Whitney U tests (CSP length). We explored sex differences due to typically higher rates of TBI among males.
Results:
History of any TBI with LOC (FTD=20.0%, HC=19.2%), TBI with LOC/PTA (FTD:32.2%, HC=31.5%), and concussion (FTD: 50.0%, HC=44.3%) was common but not different between study groups (p’s>.4). In both FTD and HC, prior TBI/concussion was nominally more frequent in males but not significantly greater than females. Frequency of repeat TBI/concussion (2+) also did not differ significantly between FTD and HC (repeat TBI with LOC: 6.7% vs. 3.3%, TBI with LOC/PTA: 12.2% vs. 10.3%, concussion: 30.2% vs. 28.7%; p’s>.2). Prior TBI/concussion was not significantly related to CSP grade or length in the total sample or within the FTD or HC groups.
Conclusions:
TBI/concussion rates depend heavily on the symptom definition used for classifying prior injury. Lifetime symptomatic TBI/concussion is common but has an unclear impact on risk for FTD-related diagnoses. Larger samples are needed to appropriately evaluate sex differences, to evaluate whether TBI/concussion rates differ between specific FTD phenotypes, and to understand the rates and effects of more extensive repetitive head trauma (symptomatic and asymptomatic) in patients with FTD.
There is increasing interest in examining a general psychopathology factor (p factor) in children and adolescents. In previous work, the relationship between the p factor and cognition in youth has largely focused on general intelligence (IQ) and executive functions (EF). Another cognitive construct, processing speed (PS), is dissociable from these cognitive constructs, but has received less research attention despite being related to many different mental health symptoms. This study aimed to examine the association between a latent processing speed factor and the p factor in youth.
Participants and Methods:
The present sample included 795 youth, ages 11-16 from the Colorado Learning Disability Research Center (CLDRC) sample. Confirmatory factor analyses tested multiple p factor models, with the primary model being a novel second-order, multireporter p factor where caregivers reported on externalizing symptoms (oppositional defiant disorder and conduct disorder modules from the Diagnostic Interview for Children and Adolescents [DICA]; aggression, delinquency, and attention problems subscales from the Child Behavior Checklist; and inattentive and hyperactive/impulsive subscales from the Disruptive Behavior Rating Scale) and youth self-reported on internalizing symptoms (Child Depression Inventory, generalized anxiety module from the DICA, and withdrawn, anxious/depression, and somatic subscales from the Youth Self Report). We then tested the correlation between the p factor and a latent PS factor. The latent PS factor was composed of WISC Symbol Search, WISC Coding, Colorado Perceptual Speed Test, and Identical Pictures Test. Three secondary p factor models were examined for comparison to previous literature, including (1) a bifactor, multi-reporter model, (2) a second-order model with just caregiver-report, and (3) a bifactor model with just caregiver-report.
Results:
There was a significant, negative correlation between the p factor and PS (r=-0.42, p<.001), indicating that slower processing speed is associated with higher general mental health symptoms. This finding was robust across models that used different raters (youth and caregiver-report vs. caregiver-report only) and modeling approaches (second-order vs. bifactor). This association is stronger than previously reported associations with IQ or EF in the p factor literature. Further, in this sample, we found that the association between PS and the p factor was robust to covariation for general cognition, whereas the correlation between general cognition and the p factor was fully accounted for by PS.
Conclusions:
Our findings indicate that PS is related to general psychopathology symptoms, expanding the existing literature relating PS to specific, distinct disorders by showing that PS is related to what is shared across psychopathology. As cognition and psychopathology both undergo significant development across childhood and adolescence, elucidating neurodevelopmental mechanisms that relate to risk for a broad range of symptoms may be critical to informing early intervention and prevention approaches. This research points to processing speed as an important transdiagnostic construct that warrants further attention and exploration across development.
Alcohol use is influenced by genetic and environmental factors. We examined the interactive effects between genome-wide polygenic risk scores for alcohol use (alc-PRS) and social support in relation to alcohol use among European American (EA) and African American (AA) adults across sex and developmental stages (emerging adulthood, young adulthood, and middle adulthood). Data were drawn from 4,011 EA and 1,274 AA adults from the Collaborative Study on the Genetics of Alcoholism who were between ages 18–65 and had ever used alcohol. Participants completed the Semi-Structured Assessment for the Genetics of Alcoholism and provided saliva or blood samples for genotyping. Results indicated that social support from friends, but not family, moderated the association between alc-PRS and alcohol use among EAs and AAs (only in middle adulthood for AAs); alc-PRS was associated with higher levels of alcohol use when friend support was low, but not when friend support was high. Associations were similar across sex but differed across developmental stages. Findings support the important role of social support from friends in buffering genetic risk for alcohol use among EA and AA adults and highlight the need to consider developmental changes in the role of social support in relation to alcohol use.
Objective, evidence-based neuroprognostication of postarrest patients is crucial to avoid inappropriate withdrawal of life-sustaining therapies or prolonged, invasive, and costly therapies that could perpetuate suffering when there is no chance of an acceptable recovery. Postarrest prognostication guidelines exist; however, guideline adherence and practice variability are unknown.
Objective:
To investigate Canadian practices and opinions regarding assessment of neurological prognosis in postarrest patients.
Methods:
An anonymous electronic survey was distributed to physicians who care for adult postarrest patients.
Results:
Of the 134 physicians who responded to the survey, 63% had no institutional protocols for neuroprognostication. While the use of targeted temperature management did not affect the timing of neuroprognostication, an increasing number of clinical findings suggestive of a poor prognosis affected the timing of when physicians were comfortable concluding patients had a poor prognosis. Variability existed in what factors clinicians’ thought were confounders. Physicians identified bilaterally absent pupillary light reflexes (85%), bilaterally absent corneal reflexes (80%), and status myoclonus (75%) as useful in determining poor prognosis. Computed tomography, magnetic resonance imaging, and spot electroencephalography were the most useful and accessible tests. Somatosensory evoked potentials were useful, but logistically challenging. Serum biomarkers were unavailable at most centers. Most (79%) physicians agreed ≥2 definitive findings on neurologic exam, electrophysiologic tests, neuroimaging, and/or biomarkers are required to determine a poor prognosis with a high degree of certainty. Distress during the process of neuroprognostication was reported by 70% of physicians and 51% request a second opinion from an external expert.
Conclusion:
Significant variability exists in post-cardiac arrest neuroprognostication practices among Canadian physicians.
Researchers have identified genetic and neural risk factors for externalizing behaviors. However, it has not yet been determined if genetic liability is conferred in part through associations with more proximal neurophysiological risk markers.
Methods
Participants from the Collaborative Study on the Genetics of Alcoholism, a large, family-based study of alcohol use disorders were genotyped and polygenic scores for externalizing (EXT PGS) were calculated. Associations with target P3 amplitude from a visual oddball task (P3) and broad endorsement of externalizing behaviors (indexed via self-report of alcohol and cannabis use, and antisocial behavior) were assessed in participants of European (EA; N = 2851) and African ancestry (AA; N = 1402). Analyses were also stratified by age (adolescents, age 12–17 and young adults, age 18–32).
Results
The EXT PGS was significantly associated with higher levels of externalizing behaviors among EA adolescents and young adults as well as AA young adults. P3 was inversely associated with externalizing behaviors among EA young adults. EXT PGS was not significantly associated with P3 amplitude and therefore, there was no evidence that P3 amplitude indirectly accounted for the association between EXT PGS and externalizing behaviors.
Conclusions
Both the EXT PGS and P3 amplitude were significantly associated with externalizing behaviors among EA young adults. However, these associations with externalizing behaviors appear to be independent of each other, suggesting that they may index different facets of externalizing.
This collection profiles understudied figures in the book and print trades of the seventeenth century. With an equal balance between women and men, it intervenes in the history of the trades, emphasising the broad range of material, cultural, and ideological work these people undertook. It offers a biographical introduction to each figure, placing them in their social, professional, and institutional settings. The collection considers varied print trade roles including that of the printer, publisher, paper-maker, and bookseller, as well as several specific trade networks and numerous textual forms. The biographies draw on extensive new archival research, with details of key sources for further study on each figure. Chronologically organised, this Element offers a primer both on numerous individual figures, and on the tribulations and innovations of the print trade in the century of revolution.