13,363 results on '"Walker S."'
Search Results
2. Assessing physiological arousal and emotional valence during behavioral intervention for pediatric feeding difficulties: A pilot study
- Author
-
Laura E. Phipps, Walker S. Arce, Seth G. Walker, and James E. Gehringer
- Subjects
avoidant restrictive food intake disorder ,biosensor ,cometrics ,happiness ,pediatric feeding disorders ,social validity ,Mental healing ,RZ400-408 ,Psychiatry ,RC435-571 - Abstract
Abstract This study's purpose is to introduce a new measurement system that objectively assesses the social validity of behavioral feeding intervention from the child's perspective via the concurrent measurement of two dimensions of emotion. To date, the primary measures of social validity for behavioral feeding intervention are caregiver treatment acceptability and satisfaction surveys. This is the first study to objectively measure two dimensions of emotion, physiological arousal and emotional valence, while children received behavioral intervention for feeding difficulties. Data collectors used a new open‐source data collection software, cometrics, developed to synchronize and record physiological and observational data. Physiological data was collected using a wearable biosensor and observers recorded an index of child happiness, unhappiness, or neither using definitions by Phipps et al. (2022) for six children with a pediatric feeding disorder. Two out of six children needed programmed habituation to the device before data collection. All children assented to wearing the device during data collection. Recorded indices mapped to separable physiological states using electrodermal activity and its constituent components, skin conductance responses and skin conductance level, in addition to skin temperature. Findings demonstrated the feasibility of measuring two dimensions of child emotions during behavioral feeding intervention and revealed that children's physiological responses were distinctly different during intervals scored as happy, unhappy, or neither. This new data collection system has implications for future research on the child's emotional experience of behavioral feeding treatment and increases the possibilities for improving clinical practice.
- Published
- 2024
- Full Text
- View/download PDF
3. Development and testing of a versatile genome editing application reporter (V-GEAR) system
- Author
-
Evan W. Kleinboehl, Kanut Laoharawee, Walker S. Lahr, Jacob D. Jensen, Joseph J. Peterson, Jason B. Bell, Beau R. Webber, and Branden S. Moriarity
- Subjects
CRISPR ,genome modification ,cas9 ,base editing ,prime editing ,reporter plasmid ,Genetics ,QH426-470 ,Cytology ,QH573-671 - Abstract
CRISPR-Cas9 and novel cas fusion proteins leveraging specific DNA targeting ability combined with deaminases or reverse transcriptases have revolutionized genome editing. However, their efficacy heavily relies upon protein variants, targeting single guide RNAs, and surrounding DNA sequence context within the targeted loci. This necessitates the need for efficient and rapid screening methods to evaluate these editing reagents and designs. Existing plasmid-based reporters lack flexibility, being fixed to specific DNA sequences, hindering direct comparisons between various editing approaches. To address this, we developed the versatile genome editing application reporter (V-GEAR) system. V-GEAR comprises genes detectable after desired editing via base editing, prime editing, or homology-directed repair within relevant genomic contexts. It employs a detectable synthetic cell surface protein (RQR8) followed by a customizable target sequence resembling genomic regions of interest. These genes allow for reliable identification of corrective editing and cell enrichment. We validated the V-GEAR system with base editors, prime editors, and Cas9-mediated homology-directed repair. Furthermore, the V-GEAR system offers versatility by allowing transient screening or stable integration at the AAVS1 safe harbor loci, rapidly achieved through immunomagnetic isolation. This innovative system enables direct comparisons among editing technologies, accelerating the development and testing of genome editing approaches.
- Published
- 2024
- Full Text
- View/download PDF
4. Anti-prion drugs do not improve survival in novel knock-in models of inherited prion disease
- Author
-
Daniel J. Walsh, Judy R. Rees, Surabhi Mehra, Matthew E. C. Bourkas, Lech Kaczmarczyk, Erica Stuart, Walker S. Jackson, Joel C. Watts, and Surachai Supattapone
- Subjects
Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Published
- 2024
5. The ratio of mesoscale convective system precipitation to total precipitation increases in future climate change scenarios
- Author
-
Alex M. Haberlie, Walker S. Ashley, Victor A. Gensini, and Allison C. Michaelis
- Subjects
Environmental sciences ,GE1-350 ,Meteorology. Climatology ,QC851-999 - Abstract
Abstract Mesoscale convective systems (MCSs) are a substantial source of precipitation in the eastern U.S. and may be sensitive to regional climatic change. We use a suite of convection-permitting climate simulations to examine possible changes in MCS precipitation. Specifically, annual and regional totals of MCS and non-MCS precipitation generated during a retrospective simulation are compared to end-of-21st-century simulations based on intermediate and extreme climate change scenarios. Both scenarios produce more MCS precipitation and less non-MCS precipitation, thus significantly increasing the proportion of precipitation associated with MCSs across the U.S.
- Published
- 2023
- Full Text
- View/download PDF
6. The impact of social-environmental factors on IQ in syndromic intellectual developmental disabilities
- Author
-
Walker S. McKinney, Desireé N. Williford, Leonard Abbeduto, and Lauren M. Schmitt
- Subjects
22q11.2 deletion syndrome ,cognitive development ,developmental disabilities ,Down syndrome ,economic stability ,environment ,fragile x syndrome ,genetic syndrome ,home environment ,intellectual developmental disabilities ,IQ ,parental stress ,social determinants of health ,social-demographic variables ,syndromic IDD ,socioeconomic status ,Medicine - Abstract
Despite having the same underlying genetic etiology, individuals with the same syndromic form of intellectual developmental disability (IDD) show a large degree of interindividual differences in cognition and IQ. Research indicates that up to 80% of the variation in IQ scores among individuals with syndromic IDDs is attributable to nongenetic effects, including social-environmental factors. In this narrative review, we summarize evidence of the influence that factors related to economic stability (focused on due to its prevalence in existing literature) have on IQ in individuals with syndromic IDDs. We also highlight the pathways through which economic stability is hypothesized to impact cognitive development and drive individual differences in IQ among individuals with syndromic IDDs. We also identify broader social-environmental factors (e.g., social determinants of health) that warrant consideration in future research, but that have not yet been explored in syndromic IDDs. We conclude by making recommendations to address the urgent need for further research into other salient factors associated with heterogeneity in IQ. These recommendations ultimately may shape individual- and community-level interventions and may inform systems-level public policy efforts to promote the cognitive development of and improve the lived experiences of individuals with syndromic IDDs.
- Published
- 2024
- Full Text
- View/download PDF
7. Decomposing the Precipitation Response to Climate Change in Convection Allowing Simulations Over the Conterminous United States
- Author
-
Brendan C. Wallace, Alex M. Haberlie, Walker S. Ashley, Vittorio A. Gensini, and Allison C. Michaelis
- Subjects
precipitation ,convection‐permitting ,regional climate ,climate change ,Astronomy ,QB1-991 ,Geology ,QE1-996.5 - Abstract
Abstract Explicit representation of finer‐scale processes can affect the sign and magnitude of the precipitation response to climate change between convection‐permitting and convection‐parameterizing models. We compare precipitation across two 15‐year epochs, a historical (HIST) and an end‐of‐21st‐century (EoC85), between a set of dynamically downscaled regional climate simulations at 3.75 km grid spacing (WRF) and bias‐corrected Community Earth System Model (CESM) output used to initialize and force the lateral boundaries of the downscaled simulations. In the historical climate, the downscaled simulations demonstrate less overall error than CESM when compared to observations for most portions of the conterminous United States. Both sets of simulations overestimate the incidence of environments with moderate to high precipitable water while CESM generally simulates rainfall that is too frequent but less intense. Within both sets of simulations, EoC85 rainfall amounts decrease in low‐moisture environments due to reduced rainfall frequency and intensity while rainfall amounts increase in high‐moisture environments as they occur more often. Overall, reductions in rainfall are stronger in WRF than in CESM, particularly during the warm season. This reduced drying in CESM is attributed to relatively higher rainfall frequency in environments with high concentrations of precipitable water and weak vertical motion. As a result, an increase in the occurrence of high moisture environments in EoC85 naturally favors more rainfall in CESM than WRF. Our results present an in‐depth examination of the characteristics of changes in overall accumulated precipitation and highlight an extra dimension of uncertainty when comparing convection‐permitting models against convection‐parameterizing models.
- Published
- 2023
- Full Text
- View/download PDF
8. Detecting aggression in clinical treatment videos
- Author
-
Walker S. Arce, Seth G. Walker, Jordan DeBrine, Benjamin S. Riggan, and James E. Gehringer
- Subjects
Machine learning ,Behavioral analysis ,Cometrics ,Transformer ,Aggression ,Cybernetics ,Q300-390 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Many clinical spaces are outfitted with centralized video recording systems to monitor patient–client interactions. Considering the increasing interest in video-based machine learning methods, the potential of using these clinical recordings to automate observational data collection is apparent. To explore this, seven patients had videos of their functional assessment and treatment sessions annotated by coders trained by our clinical team. Commonly used clinical software has inherent limitations aligning behavioral and video data, so a custom software tool was employed to address this functionality gap. After developing a Canvas-based coder training course for this tool, a team of six trained coders annotated 82.33 h of data. Two machine learning approaches were considered, where both used a convolutional neural network as a video feature extractor. The first approach used a recurrent network as the classifier on the extracted features and the second used a Transformer architecture. Both models produced promising metrics indicating that the capability of detecting aggression from clinical videos is possible and generalizable. Model performance is directly tied to the feature extractor’s performance on ImageNet, where ConvNeXtXL produced the best performing models. This has applications in automating patient incident response to improve patient and clinician safety and could be directly integrated into existing video management systems for real-time analysis.
- Published
- 2023
- Full Text
- View/download PDF
9. Germline T cell receptor exchange results in physiological T cell development and function
- Author
-
Meagan R. Rollins, Jackson F. Raynor, Ebony A. Miller, Jonah Z. Butler, Ellen J. Spartz, Walker S. Lahr, Yun You, Adam L. Burrack, Branden S. Moriarity, Beau R. Webber, and Ingunn M. Stromnes
- Subjects
Science - Abstract
The currently available transgenic T cell receptor (TCR) models represent high affinity antigen-TCR interactions. Authors here present an alternative approach to target an exogenous TCR into the physiological Trac locus in the germline of mice, which uncovers that the natural genomic context for TCRs can enhance the antigen sensitivity of lower affinity TCRs and enables the physiologic range of antigen-TCR interaction and a gene dosage dependent mechanism of central tolerance.
- Published
- 2023
- Full Text
- View/download PDF
10. Cerebellar granule neurons induce Cyclin D1 before the onset of motor symptoms in Huntington’s disease mice
- Author
-
Susanne Bauer, Chwen-Yu Chen, Maria Jonson, Lech Kaczmarczyk, Srivathsa Subramanya Magadi, and Walker S. Jackson
- Subjects
Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Although Huntington’s disease (HD) is classically defined by the selective vulnerability of striatal projection neurons, there is increasing evidence that cerebellar degeneration modulates clinical symptoms. However, little is known about cell type-specific responses of cerebellar neurons in HD. To dissect early disease mechanisms in the cerebellum and cerebrum, we analyzed translatomes of neuronal cell types from both regions in a new HD mouse model. For this, HdhQ200 knock-in mice were backcrossed with the calm 129S4 strain, to constrain experimental noise caused by variable hyperactivity of mice in a C57BL/6 background. Behavioral and neuropathological characterization showed that these S4-HdhQ200 mice had very mild behavioral abnormalities starting around 12 months of age that remained mild up to 18 months. By 9 months, we observed abundant Huntingtin-positive neuronal intranuclear inclusions (NIIs) in the striatum and cerebellum. The translatome analysis of GABAergic cells of the cerebrum further confirmed changes typical of HD-induced striatal pathology. Surprisingly, we observed the strongest response with 626 differentially expressed genes in glutamatergic neurons of the cerebellum, a population consisting primarily of granule cells, commonly considered disease resistant. Our findings suggest vesicular fusion and exocytosis, as well as differentiation-related pathways are affected in these neurons. Furthermore, increased expression of cyclin D1 (Ccnd1) in the granular layer and upregulated expression of polycomb group complex protein genes and cell cycle regulators Cbx2, Cbx4 and Cbx8 point to a putative role of aberrant cell cycle regulation in cerebellar granule cells in early disease.
- Published
- 2023
- Full Text
- View/download PDF
11. Selective Vulnerability to Neurodegenerative Disease: Insights from Cell Type-Specific Translatome Studies
- Author
-
Walker S. Jackson, Susanne Bauer, Lech Kaczmarczyk, and Srivathsa S. Magadi
- Subjects
Huntington’s disease ,Alzheimer’s disease ,prion disease ,amyotrophic lateral sclerosis ,RiboTag ,bacTRAP ,Biology (General) ,QH301-705.5 - Abstract
Neurodegenerative diseases (NDs) manifest a wide variety of clinical symptoms depending on the affected brain regions. Gaining insights into why certain regions are resistant while others are susceptible is vital for advancing therapeutic strategies. While gene expression changes offer clues about disease responses across brain regions, the mixture of cell types therein obscures experimental results. In recent years, methods that analyze the transcriptomes of individual cells (e.g., single-cell RNA sequencing or scRNAseq) have been widely used and have provided invaluable insights into specific cell types. Concurrently, transgene-based techniques that dissect cell type-specific translatomes (CSTs) in model systems, like RiboTag and bacTRAP, offer unique advantages but have received less attention. This review juxtaposes the merits and drawbacks of both methodologies, focusing on the use of CSTs in understanding conditions like amyotrophic lateral sclerosis (ALS), Huntington’s disease (HD), Alzheimer’s disease (AD), and specific prion diseases like fatal familial insomnia (FFI), genetic Creutzfeldt–Jakob disease (gCJD), and acquired prion disease. We conclude by discussing the emerging trends observed across multiple diseases and emerging methods.
- Published
- 2024
- Full Text
- View/download PDF
12. A BAFF ligand-based CAR-T cell targeting three receptors and multiple B cell cancers
- Author
-
Derek P. Wong, Nand K. Roy, Keman Zhang, Anusha Anukanth, Abhishek Asthana, Nicole J. Shirkey-Son, Samantha Dunmire, Bryan J. Jones, Walker S. Lahr, Beau R. Webber, Branden S. Moriarity, Paolo Caimi, and Reshmi Parameswaran
- Subjects
Science - Abstract
Antigen escape represents a potential drawback of chimeric antigen receptor T cell (CAR-T) therapy targeting a single tumor-associated antigen. To reduce the risk of antigen escape, here the authors report the design and characterization of a BAFF ligand CAR-T that can recognize three different receptors (BAFF-R, BCMA and TACI), demonstrating in vitro and in vivo cytotoxicity against multiple B cell cancer models.
- Published
- 2022
- Full Text
- View/download PDF
13. Hidden Cooling Flows in Elliptical Galaxies
- Author
-
Ivey, L. R., Fabian, A. C., Sanders, J. S., Pinto, C., Ferland, G. J., Walker, S., and Jiang, J.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
The radiative cooling time of hot gas in the cool cores of many galaxy clusters and massive elliptical galaxies drops in the centre to below 100 million years. The mass cooling rates inferred from simple modelling of X-ray observations of these objects are very low, indicating that either AGN feedback is tightly balanced or that soft X-rays from cooling gas are somehow hidden from view. An intrinsic absorption model developed for application to galaxy clusters is used here to search for hidden cooling flows (HCFs) in seven nearby elliptical galaxies. Mass cooling rates of 0.5-8 solar masses per year are found in each galaxy. The absorbed cooling flow luminosity is in agreement with the observed Far Infrared (FIR) luminosity in each case, indicating absorbed emission is energetically capable of emerging in the FIR band. An observed lack of agreement between HCF rates and normal star formation rates suggests the cooled material must have an alternative fate, with low-mass star formation considered as the primary outcome., Comment: 17 pages, 14 figures, 7 tables. Accepted for publication in MNRAS
- Published
- 2024
14. Hidden Cooling Flows IV: More Details on Centaurus and the Efficiency of AGN Feedback in Clusters
- Author
-
Fabian, A. C., Ferland, G. J., Sanders, J. S., Russell, H. R., McNamara, B. R., Pinto, C., Hlavacek-Larrondo, J., Walker, S. A., Ivey, L. R., and McDonald, M.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Cooling flows are common in galaxy clusters which have cool cores. The soft X-ray emission below 1 keV from the flows is mostly absorbed by cold dusty gas within the central cooling sites. Further evidence for this process is presented here through a more detailed analysis of the nearby Centaurus cluster and some additional clusters. Predictions of JWST near and mid-infrared spectra from cooling gas are presented. [NeVI] emission at 7.65 micron should be an important diagnostic of gas cooling between 6 and 1.5 times 10^5 K. The emerging overall picture of hidden cooling flows is explored. The efficiency of AGN feedback in reducing the total cooling rate in cool cores is shown to be above 50 percent for many clusters but is rarely above 90 per cent. The reduction is mostly in outer gas. Cooling dominates in elliptical galaxies and galaxy groups which have mass flow rates below about 15M/yr and in some massive clusters where rates can exceed 1000M/yr., Comment: 17 pages, 49 figures submitted to MNRAS
- Published
- 2024
15. Corrigendum: Cerebellar volumes and sensorimotor behavior in autism spectrum disorder
- Author
-
Walker S. McKinney, Shannon E. Kelly, Kathryn E. Unruh, Robin L. Shafer, John A. Sweeney, Martin Styner, and Matthew W. Mosconi
- Subjects
cerebellum ,volumetry ,autism spectrum disorder (ASD) ,sensorimotor ,oculomotor ,MRI ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Published
- 2022
- Full Text
- View/download PDF
16. Initial action output and feedback-guided motor behaviors in autism spectrum disorder
- Author
-
Kathryn E. Unruh, Walker S. McKinney, Erin K. Bojanek, Kandace K. Fleming, John A. Sweeney, and Matthew W. Mosconi
- Subjects
Autism spectrum disorder (ASD) ,Sensorimotor ,Eye movement ,Precision grip ,Lateralization ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Sensorimotor issues are common in autism spectrum disorder (ASD), related to core symptoms, and predictive of worse functional outcomes. Deficits in rapid behaviors supported primarily by feedforward mechanisms, and continuous, feedback-guided motor behaviors each have been reported, but the degrees to which they are distinct or co-segregate within individuals and across development are not well understood. Methods We characterized behaviors that varied in their involvement of feedforward control relative to feedback control across skeletomotor (precision grip force) and oculomotor (saccades) control systems in 109 individuals with ASD and 101 age-matched typically developing controls (range: 5–29 years) including 58 individuals with ASD and 57 controls who completed both grip and saccade tests. Grip force was examined across multiple force (15, 45, and 85% MVC) and visual gain levels (low, medium, high). Maximum grip force also was examined. During grip force tests, reaction time, initial force output accuracy, variability, and entropy were examined. For the saccade test, latency, accuracy, and trial-wise variability of latency and accuracy were examined. Results Relative to controls, individuals with ASD showed similar accuracy of initial grip force but reduced accuracy of saccadic eye movements specific to older ages of our sample. Force variability was greater in ASD relative to controls, but saccade gain variability (across trials) was not different between groups. Force entropy was reduced in ASD, especially at older ages. We also find reduced grip strength in ASD that was more severe in dominant compared to non-dominant hands. Limitations Our age-related findings rely on cross-sectional data. Longitudinal studies of sensorimotor behaviors and their associations with ASD symptoms are needed. Conclusions We identify reduced accuracy of initial motor output in ASD that was specific to the oculomotor system implicating deficient feedforward control that may be mitigated during slower occurring behaviors executed in the periphery. Individuals with ASD showed increased continuous force variability but similar levels of trial-to-trial saccade accuracy variability suggesting that feedback-guided refinement of motor commands is deficient specifically when adjustments occur rapidly during continuous behavior. We also document reduced lateralization of grip strength in ASD implicating atypical hemispheric specialization.
- Published
- 2021
- Full Text
- View/download PDF
17. Engineering T cells to enhance 3D migration through structurally and mechanically complex tumor microenvironments
- Author
-
Erdem D. Tabdanov, Nelson J. Rodríguez-Merced, Alexander X. Cartagena-Rivera, Vikram V. Puram, Mackenzie K. Callaway, Ethan A. Ensminger, Emily J. Pomeroy, Kenta Yamamoto, Walker S. Lahr, Beau R. Webber, Branden S. Moriarity, Alexander S. Zhovmer, and Paolo P. Provenzano
- Subjects
Science - Abstract
The mechanics of the migration of T cells into tumours is an important aspect of tumour immunity. Here the authors engineer complex 3D environments to explore functions of microtubules and cell contractility as strategies to enhance T cell migration in tumour microenvironments.
- Published
- 2021
- Full Text
- View/download PDF
18. CRISPR-Cas9 cytidine and adenosine base editing of splice-sites mediates highly-efficient disruption of proteins in primary and immortalized cells
- Author
-
Mitchell G. Kluesner, Walker S. Lahr, Cara-lin Lonetree, Branden A. Smeester, Xiaohong Qiu, Nicholas J. Slipek, Patricia N. Claudio Vázquez, Samuel P. Pitzen, Emily J. Pomeroy, Madison J. Vignes, Samantha C. Lee, Samuel P. Bingea, Aneesha A. Andrew, Beau R. Webber, and Branden S. Moriarity
- Subjects
Science - Abstract
Base editors can inactivate splice sites or introduce stop codons into a gene sequence. Here the authors present SpliceR to design, rank, and test sgRNAs for efficient gene disruption in T cells.
- Published
- 2021
- Full Text
- View/download PDF
19. Slc1a3-2A-CreERT2 mice reveal unique features of Bergmann glia and augment a growing collection of Cre drivers and effectors in the 129S4 genetic background
- Author
-
Lech Kaczmarczyk, Nicole Reichenbach, Nelli Blank, Maria Jonson, Lars Dittrich, Gabor C. Petzold, and Walker S. Jackson
- Subjects
Medicine ,Science - Abstract
Abstract Genetic variation is a primary determinant of phenotypic diversity. In laboratory mice, genetic variation can be a serious experimental confounder, and thus minimized through inbreeding. However, generalizations of results obtained with inbred strains must be made with caution, especially when working with complex phenotypes and disease models. Here we compared behavioral characteristics of C57Bl/6—the strain most widely used in biomedical research—with those of 129S4. In contrast to 129S4, C57Bl/6 demonstrated high within-strain and intra-litter behavioral hyperactivity. Although high consistency would be advantageous, the majority of disease models and transgenic tools are in C57Bl/6. We recently established six Cre driver lines and two Cre effector lines in 129S4. To augment this collection, we genetically engineered a Cre line to study astrocytes in 129S4. It was validated with two Cre effector lines: calcium indicator gCaMP5g-tdTomato and RiboTag—a tool widely used to study cell type-specific translatomes. These reporters are in different genomic loci, and in both the Cre was functional and astrocyte-specific. We found that calcium signals lasted longer and had a higher amplitude in cortical compared to hippocampal astrocytes, genes linked to a single neurodegenerative disease have highly divergent expression patterns, and that ribosome proteins are non-uniformly expressed across brain regions and cell types.
- Published
- 2021
- Full Text
- View/download PDF
20. Factors Associated with Concurrent Tobacco Smoking and Heavy Drinking within a Women Firefighters’ Sample
- Author
-
Nattinee Jitnarin, Christopher K. Haddock, Christopher M. Kaipust, Walker S. C. Poston, and Sara A. Jahnke
- Subjects
alcohol ,heavy drinking ,tobacco use ,smoking ,concurrent use ,women firefighters ,Physics ,QC1-999 - Abstract
Studies showed that tobacco use and excessive alcohol consumption frequently occur, and both are significant causes of preventable morbidity and mortality. Data were collected as part of a national online study of the health of women in the fire service. Multinomial logistic regression was employed to determine factors associated with smoking and drinking characteristics. A total of 2330 women firefighters completed questions regarding tobacco and alcohol use; 3.2% (n = 75) were concurrent users, 0.9% (n = 22) were smokers only, 49.4% (n = 1150) were heavy drinkers only, and 46.5% (n = 1083) were low-risk users. Compared with those who neither smoked nor binge drank, concurrent users were more likely to be younger and live alone or not married. The findings also suggested that smokers, heavy drinkers, or those who were both were more likely to report symptoms of depression and PTSD and a history of physician diagnosis of anxiety disorder compared to low-risk users. Smoking rates are relatively low among women firefighters; however, mental health risks are prevalent, particularly for those who both smoked and drank heavily. Results can be potentially used to inform prevention and treatment research to better address the unique condition of this occupational group.
- Published
- 2023
- Full Text
- View/download PDF
21. Cerebellar Volumes and Sensorimotor Behavior in Autism Spectrum Disorder
- Author
-
Walker S. McKinney, Shannon E. Kelly, Kathryn E. Unruh, Robin L. Shafer, John A. Sweeney, Martin Styner, and Matthew W. Mosconi
- Subjects
cerebellum ,volumetry ,autism spectrum disorder (ASD) ,sensorimotor ,oculomotor ,MRI ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
BackgroundSensorimotor issues are common in autism spectrum disorder (ASD), though their neural bases are not well understood. The cerebellum is vital to sensorimotor control and reduced cerebellar volumes in ASD have been documented. Our study examined the extent to which cerebellar volumes are associated with multiple sensorimotor behaviors in ASD.Materials and MethodsFifty-eight participants with ASD and 34 typically developing (TD) controls (8–30 years) completed a structural MRI scan and precision grip testing, oculomotor testing, or both. Force variability during precision gripping as well as absolute error and trial-to-trial error variability of visually guided saccades were examined. Volumes of cerebellar lobules, vermis, and white matter were quantified. The relationships between each cerebellar region of interest (ROI) and force variability, saccade error, and saccade error variability were examined.ResultsRelative to TD controls, individuals with ASD showed increased force variability. Individuals with ASD showed a reduced volume of cerebellar vermis VI-VII relative to TD controls. Relative to TD females, females with ASD showed a reduced volume of bilateral cerebellar Crus II/lobule VIIB. Increased volume of Crus I was associated with increased force variability. Increased volume of vermal lobules VI-VII was associated with reduced saccade error for TD controls but not individuals with ASD. Increased right lobule VIII and cerebellar white matter volumes as well as reduced right lobule VI and right lobule X volumes were associated with greater ASD symptom severity. Reduced volumes of right Crus II/lobule VIIB were associated with greater ASD symptom severity in only males, while reduced volumes of right Crus I were associated with more severe restricted and repetitive behaviors only in females.ConclusionOur finding that increased force variability in ASD is associated with greater cerebellar Crus I volumes indicates that disruption of sensory feedback processing supported by Crus I may contribute to skeletomotor differences in ASD. Results showing that volumes of vermal lobules VI-VII are associated with saccade precision in TD but not ASD implicates atypical organization of the brain systems supporting oculomotor control in ASD. Associations between volumes of cerebellar subregions and ASD symptom severity suggest cerebellar pathological processes may contribute to multiple developmental challenges in ASD.
- Published
- 2022
- Full Text
- View/download PDF
22. Measuring the ICM velocity structure within the A3266 galaxy cluster
- Author
-
Gatuzz, E., Sanders, J., Liu, A., Fabian, A., Pinto, C., Russell, H., Eckert, D., Walker, S., ZuHone, J., and Mohapatra, R.
- Subjects
Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Cosmology and Nongalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
We present a detailed analysis of the velocity structure of the hot intracluster medium (ICM) within the A3266 galaxy cluster, including new observations taken between June and November 2023. Firstly, morphological structures within the galaxy cluster were examined using a Gaussian Gradient Magnitude (GGM) and adaptively smoothed GGM filter applied to the EPIC-pn X-ray image. Then, we applied a novel {\it XMM-Newton} EPIC-pn energy scale calibration, which uses instrumental Cu K$\alpha$ as reference for the line emission, to measure line-of-sight velocities of the hot gas within the system. This approach enabled us to create two-dimensional projected maps for velocity, temperature, and metallicity, showing that the hot gas displays a redshifted systemic velocity relative to the cluster redshift across all fields of view. Further analysis of the velocity distribution through non-overlapping circular regions demonstrated consistent redshifted velocities extending up to 1125 kpc from the cluster core. Additionally, the velocity distribution was assessed along regions following surface brightness discontinuities, where we observed redshifted velocities in all regions, with the largest velocities reaching $768 \pm 284$ km/s. Moreover, we computed the velocity Probability Density Function (PDF) from the velocity map. We applied a normality test, finding that the PDF adheres to an unimodal normal distribution consistent with theoretical predictions. Lastly, we computed a velocity structure function (VSF) for this system using the measured line-of-sight velocities. These insights advance our understanding of the dynamic processes within the A3266 galaxy cluster and contribute to our broader knowledge of ICM behavior in merging galaxy clusters., Comment: 12 pages, 15 figures, This paper is part of a series on the ICM velocity structure using XMM-Newton observations. Related series papers: arXiv:2109.06213, arXiv:2203.12635; doi:10.1093/mnras/stad1132; arXiv:2303.17556
- Published
- 2024
23. Evidence of nutrient translocation in response to smoke exposure by the East African ant acacia, Vachellia drepanolobium
- Author
-
Richard Rabideau‐Childers, Katherine I. W. Angier, Brendan Z. M. Dean, Meghan Blumstein, Walker S. Darling, Annina Kennedy‐Yoon, Clayton H. Ziemke, Christian A. Perez‐Martinez, Donghao Wu, Wenqing Ye, Inam Yekwayo, Duncan M. Kimuyu, Dino J. Martins, and Naomi E. Pierce
- Subjects
fire ,Kenya ,root‐shoot ratio ,savanna ,transport ,volatile ,Ecology ,QH540-549.5 - Abstract
Abstract Fire is a major selective force on arid grassland communities, favoring traits such as the smoke‐induced seed germination response seen in a wide variety of plant species. However, little is known about the relevance of smoke as a cue for plants beyond the seedling stage. We exposed a fire‐adapted savanna tree, Vachellia (=Acacia) drepanolobium, to smoke and compared nutrient concentrations in leaf and root tissues to unexposed controls. Experiments were performed on three age cohorts: 2‐year‐old, 9‐month‐old, and 3‐month‐old plants. For the 2‐year‐old plants exposed to smoke, carbon and nitrogen concentrations were lower in the leaves and higher in the roots than controls. Less pronounced trends were found for boron and magnesium. In contrast, smoke‐exposed 3‐month‐old plants had lower root nitrogen concentrations than controls. No significant differences were found in the 9‐month‐old plants, and no significant shifts in other nutrient concentrations were observed between plant tissues for any of the three age cohorts. Synthesis: Our findings are consistent with smoke‐induced translocation of nutrients from leaves to roots in 2‐year‐old V. drepanolobium. This could represent a novel form of fire adaptation, with variation over the course of plant development. The translocation differences between age cohorts highlight the need to investigate smoke response in older plants of other species. Accounting for this adaptation could better inform our understanding of savanna community structure and nutrient flows under fire regimes altered by anthropogenic land use and climate change.
- Published
- 2022
- Full Text
- View/download PDF
24. Comparisons of Baseline Obesity Prevalence and Its Association with Perceived Health and Physical Performance in Military Officers
- Author
-
Brittany S. Hollerbach, Christopher K. Haddock, Filip Kukić, Walker S. C. Poston, Nattinee Jitnarin, Sara A. Jahnke, Justin A. DeBlauw, and Katie M. Heinrich
- Subjects
soldiers ,first responders ,body composition ,body fat ,waist-to-height ratio ,body mass index ,Biology (General) ,QH301-705.5 - Abstract
Increasing obesity rates among USA military members vary by age, pay grade, and measurement methods and threaten force fitness and readiness. Limited research has directly measured obesity among officers; those enrolled in graduate school at the Command and General Staff College (CGSC) face additional demands and increased obesity risk. This study compared obesity measurements and performance on the Army Physical Fitness test and self-rated health for a sample of mostly CGSC officers. Participants (n = 136, 75.7% male, 79.6% officers) completed body composition measures; BMI, body fat percentage (BF%), waist circumference (WC), and waist-to-height ratio (WHtR) estimated obesity rates and were compared for discordance. Army Physical Fitness Test pass/fail rates and self-reported perceived health were compared with each obesity classification. Obesity prevalence was 18.5–39.7%, differing by sex and measure. BMI, WC, and WHtR underestimated obesity compared to BF% at least 21% of the time. WHtR had the lowest discordance with BF%. Soldiers categorized as obese were significantly more likely to fail the fitness test and report lower self-rated health than non-obese soldiers. Overall, obesity rates among our primarily officer sample were higher than previous studies, particularly for women. Interventions to address obesity are necessary among military officers to optimize human performance.
- Published
- 2022
- Full Text
- View/download PDF
25. CalDAG-GEFI mediates striatal cholinergic modulation of dendritic excitability, synaptic plasticity and psychomotor behaviors
- Author
-
Jill R. Crittenden, Shenyu Zhai, Magdalena Sauvage, Takashi Kitsukawa, Eric Burguière, Morgane Thomsen, Hui Zhang, Cinzia Costa, Giuseppina Martella, Veronica Ghiglieri, Barbara Picconi, Karen A. Pescatore, Ellen M. Unterwald, Walker S. Jackson, David E. Housman, S. Barak Caine, David Sulzer, Paolo Calabresi, Anne C. Smith, D. James Surmeier, and Ann M. Graybiel
- Subjects
Striatum ,M1 muscarinic receptor ,Kir2 ,Dendritic excitability ,Stereotypy ,Amphetamine ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
CalDAG-GEFI (CDGI) is a protein highly enriched in the striatum, particularly in the principal spiny projection neurons (SPNs). CDGI is strongly down-regulated in two hyperkinetic conditions related to striatal dysfunction: Huntington's disease and levodopa-induced dyskinesia in Parkinson's disease. We demonstrate that genetic deletion of CDGI in mice disrupts dendritic, but not somatic, M1 muscarinic receptors (M1Rs) signaling in indirect pathway SPNs. Loss of CDGI reduced temporal integration of excitatory postsynaptic potentials at dendritic glutamatergic synapses and impaired the induction of activity-dependent long-term potentiation. CDGI deletion selectively increased psychostimulant-induced repetitive behaviors, disrupted sequence learning, and eliminated M1R blockade of cocaine self-administration. These findings place CDGI as a major, but previously unrecognized, mediator of cholinergic signaling in the striatum. The effects of CDGI deletion on the self-administration of drugs of abuse and its marked alterations in hyperkinetic extrapyramidal disorders highlight CDGI's therapeutic potential.
- Published
- 2021
- Full Text
- View/download PDF
26. Highly efficient multiplex human T cell engineering without double-strand breaks using Cas9 base editors
- Author
-
Beau R. Webber, Cara-lin Lonetree, Mitchell G. Kluesner, Matthew J. Johnson, Emily J. Pomeroy, Miechaleen D. Diers, Walker S. Lahr, Garrett M. Draper, Nicholas J. Slipek, Branden A. Smeester, Klaus N. Lovendahl, Amber N. McElroy, Wendy R. Gordon, Mark J. Osborn, and Branden S. Moriarity
- Subjects
Science - Abstract
Multiplexed genome engineering with Cas9 can increase efficiency but also the risk of unintended alterations. Here the authors demonstrate the use of multiplexed base editors on primary T cells with reduced translocation frequency.
- Published
- 2019
- Full Text
- View/download PDF
27. The association between television viewing time and percent body fat in adults varies as a function of physical activity and sex
- Author
-
Richard R. Suminski, Freda Patterson, Mackenzie Perkett, Katie M. Heinrich, and Walker S. Carlos Poston
- Subjects
Obesity ,Sedentary behavior ,Survey research ,Cross-sectional ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Data suggest that sedentary behavior is an independent risk factor for obesity; however, the extent to which physical activity (PA) and sex alter this relationship remains unclear. To address this gap, the current study examined the association between television (TV) viewing time and percent body fat (%BF) as a function of PA level and sex. Methods Trained interviewers assessed 454 adults at their place of residence. Participants completed questionnaires to determine h of TV watched per week, PA level (inactive = not meeting PA guidelines vs. active = meeting PA guideline), and covariates including demographics (e.g., sex), depression symptoms, perceived stress, fruit and vegetable intake, and environmental support for PA. Foot-to-foot bioelectrical impedance (Tanita TBF-300, Tokyo, Japan) was used to assess %BF. Mixed models were generated to examine the association between TV h/wk. and %BF as a function of PA level and sex while accounting for the multi-level nature of the data (neighborhood- and individual-levels) and covariates. Results Participants were 44.4 ± 14.0 (Mean + Standard Deviation) years of age with 33.2 ± 11.1%BF, and watched 19.3 ± 15.5 h/wk. of TV. Most were female (70.9%) and inactive (63.2%). Mixed model regression demonstrated that among inactive participants, each additional h of TV viewed/wk. was associated with a 1.03% increase in %BF; TV h/wk. and %BF were not associated in active adults. When models were further stratified by sex, h of TV viewed/wk. were significantly associated with %BF only in inactive females. Each additional h of TV viewed/wk. was associated with an increase in %BF of 1.14%. Conclusion: Interventions targeting PA and/or TV viewing time may be a high-priority to curb excess BF accumulation especially among inactive females.
- Published
- 2019
- Full Text
- View/download PDF
28. Examining a novel firefighter exercise training program on simulated fire ground test performance, cardiorespiratory endurance, and strength: a pilot investigation
- Author
-
Brittany S. Hollerbach, Sara A. Jahnke, Walker S. C. Poston, Craig A. Harms, and Katie M. Heinrich
- Subjects
Firefighter ,Health ,Occupational health ,Fitness ,HIFT ,Industrial medicine. Industrial hygiene ,RC963-969 - Abstract
Abstract Background Firefighting is a dangerous occupation with high rates of injuries and fatalities, with the majority of line of duty fatalities due to cardiovascular events. Additionally, firefighters struggle with poor health/low levels of fitness, including high (> 80%) rates of overweight and obesity. Limited resources exist for fire departments that are tailored to the culture and work requirements of these “tactical athletes”. Though there has been increasing interest in high intensity functional training (HIFT) programs, research data are lacking among firefighters and few studies have focused on training recruits. The purpose of this pilot investigation was to examine a novel HIFT program (TF20) on fire academy recruits’ health, fitness, and performance as determined by a simulated fire ground test (SFGT), as well as determining the program’s acceptability and feasibility. Methods Thirteen participants were recruited from an entry level fire academy and were randomly assigned to the control (CG, n = 6) or HIFT group (TF20, n = 7). The CG was asked to continue current exercise habits. TF20 was provided a 10-week online based training program that included periodized workouts, nutritional information, and mental readiness education. Due to attrition within the first two weeks of the study, 10 male fire recruits (23 ± 3 years) completed the study (CG, n = 3, TF20, n = 7). All 10 participants completed baseline and follow-up assessments. Results The TF20 group showed improvement on numerous outcome measures including SFGT (40% passing at baseline, 86% passing post-intervention). TF20 participants significantly increased estimated VO2max (p = 0.028), improved body composition (p = 0.028), and improved grip strength (p = 0.018). The CG did not experience any significant changes. The TF20 group completed approximately 75% of the assigned workouts. Conclusion While TF20 participants showed significant fitness gains, the small sample size limited direct comparisons to the CG. TF20 was well-received although there may be a better way to implement the intervention to increase participation. This investigation provides promising outcomes, useful information about implementation, feasibility, and acceptability for the TF20 HIFT program among firefighter recruits. IRB #8063 APPROVED 01/04/2016. Trial registration NCT03319394. Registered 28 September 2014. Retrospectively registered.
- Published
- 2019
- Full Text
- View/download PDF
29. A Pan-RNase Inhibitor Enabling CRISPR-mRNA Platforms for Engineering of Primary Human Monocytes
- Author
-
Kanut Laoharawee, Matthew J. Johnson, Walker S. Lahr, Christopher J. Sipe, Evan Kleinboehl, Joseph J. Peterson, Cara-lin Lonetree, Jason B. Bell, Nicholas J. Slipek, Andrew T. Crane, Beau R. Webber, and Branden S. Moriarity
- Subjects
primary human monocytes ,pan-RNase inhibitor ,CRISPR-Cas9 ,base editor ,genome engineering ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Monocytes and their downstream effectors are critical components of the innate immune system. Monocytes are equipped with chemokine receptors, allowing them to migrate to various tissues, where they can differentiate into macrophage and dendritic cell subsets and participate in tissue homeostasis, infection, autoimmune disease, and cancer. Enabling genome engineering in monocytes and their effector cells will facilitate a myriad of applications for basic and translational research. Here, we demonstrate that CRISPR-Cas9 RNPs can be used for efficient gene knockout in primary human monocytes. In addition, we demonstrate that intracellular RNases are likely responsible for poor and heterogenous mRNA expression as incorporation of pan-RNase inhibitor allows efficient genome engineering following mRNA-based delivery of Cas9 and base editor enzymes. Moreover, we demonstrate that CRISPR-Cas9 combined with an rAAV vector DNA donor template mediates site-specific insertion and expression of a transgene in primary human monocytes. Finally, we demonstrate that SIRPa knock-out monocyte-derived macrophages have enhanced activity against cancer cells, highlighting the potential for application in cellular immunotherapies.
- Published
- 2022
- Full Text
- View/download PDF
30. Correction of Fanconi Anemia Mutations Using Digital Genome Engineering
- Author
-
Christopher J. Sipe, Mitchell G. Kluesner, Samuel P. Bingea, Walker S. Lahr, Aneesha A. Andrew, Minjing Wang, Anthony P. DeFeo, Timothy L. Hinkel, Kanut Laoharawee, John E. Wagner, Margaret L. MacMillan, Gregory M. Vercellotti, Jakub Tolar, Mark J. Osborn, R. Scott McIvor, Beau R. Webber, and Branden S. Moriarity
- Subjects
Fanconi anemia (FA) ,gene therapy ,base editing ,adenine base editing (ABE) ,cytosine base editing (CBE) ,CRISPR-Cas9 ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Fanconi anemia (FA) is a rare genetic disease in which genes essential for DNA repair are mutated. Both the interstrand crosslink (ICL) and double-strand break (DSB) repair pathways are disrupted in FA, leading to patient bone marrow failure (BMF) and cancer predisposition. The only curative therapy for the hematological manifestations of FA is an allogeneic hematopoietic cell transplant (HCT); however, many (>70%) patients lack a suitable human leukocyte antigen (HLA)-matched donor, often resulting in increased rates of graft-versus-host disease (GvHD) and, potentially, the exacerbation of cancer risk. Successful engraftment of gene-corrected autologous hematopoietic stem cells (HSC) circumvents the need for an allogeneic HCT and has been achieved in other genetic diseases using targeted nucleases to induce site specific DSBs and the correction of mutated genes through homology-directed repair (HDR). However, this process is extremely inefficient in FA cells, as they are inherently deficient in DNA repair. Here, we demonstrate the correction of FANCA mutations in primary patient cells using ‘digital’ genome editing with the cytosine and adenine base editors (BEs). These Cas9-based tools allow for C:G > T:A or A:T > C:G base transitions without the induction of a toxic DSB or the need for a DNA donor molecule. These genetic corrections or conservative codon substitution strategies lead to phenotypic rescue as illustrated by a resistance to the alkylating crosslinking agent Mitomycin C (MMC). Further, FANCA protein expression was restored, and an intact FA pathway was demonstrated by downstream FANCD2 monoubiquitination induction. This BE digital correction strategy will enable the use of gene-corrected FA patient hematopoietic stem and progenitor cells (HSPCs) for autologous HCT, obviating the risks associated with allogeneic HCT and DSB induction during autologous HSC gene therapy.
- Published
- 2022
- Full Text
- View/download PDF
31. Consequences of a low-mass, high-pressure, star formation mode in early galaxies
- Author
-
Fabian, A. C., Sanders, J. S., Ferland, G. J., McNamara, B. R., Pinto, C., and Walker, S. A.
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
High resolution X-ray spectra reveal hidden cooling flows depositing cold gas at the centres of massive nearby early-type galaxies with little sign of normal star formation. Optical observations are revealing that a bottom-heavy Initial Mass Function is common within the inner kpc of similar galaxies. We revive the possibility that a low-mass star formation mode is operating due to the high thermal pressure in the cooling flow, thus explaining the accumulation of low-mass stars. We further explore whether such a mode operated in early, high-redshift galaxies and has sporadically continued to the present day. The idea links observed distant galaxies with black holes which are ultramassive for their stellar mass, nearby red nuggets and massive early-type galaxies. Nearby elliptical galaxies may be red but they are not dead., Comment: 4 pages, 2 Figures, Accepted for publication in MNRAS
- Published
- 2024
32. Technical Design Report for the LUXE experiment
- Author
-
Abramowicz, H., Almanza Soto, M., Altarelli, M., Aßmann, R., Athanassiadis, A., Avoni, G., Behnke, T., Benettoni, M., Benhammou, Y., Bhatt, J., Blackburn, T., Blanch, C., Bonaldo, S., Boogert, S., Borysov, O., Borysova, M., Boudry, V., Breton, D., Brinkmann, R., Bruschi, M., Burkart, F., Büßer, K., Cavanagh, N., Dal Corso, F., Decking, W., Deniaud, M., Diner, O., Dosselli, U., Elad, M., Epshteyn, L., Esperante, D., Ferber, T., Firlej, M., Fiutowski, T., Fleck, K., Fuster-Martinez, N., Gadow, K., Gaede, F., Gallas, A., Garcia Cabrera, H., Gerstmayr, E., Ghenescu, V., Giorato, M., Golubeva, N., Grojean, C., Grutta, P., Grzelak, G., Hallford, J., Hartman, L., Heinemann, B., Heinzl, T., Helary, L., Hendriks, L., Hoffmann, M., Horn, D., Huang, S., Huang, X., Idzik, M., Irles, A., Jacobs, R., King, B., Klute, M., Kropf, A., Kroupp, E., Lahno, H., Lasagni Manghi, F., Lawhorn, J., Levanon, A., Levi, A., Levinson, L., Levy, A., Levy, I., Liberman, A., Liss, B., List, B., List, J., Lohmann, W., Maalmi, J., Madlener, T., Malka, V., Marsault, T., Mattiazzo, S., Meloni, F., Miron, D., Morandin, M., Moroń, J., Nanni, J., Neagu, A. T., Negodin, E., Paccagnella, A., Pantano, D., Pietruch, D., Pomerantz, I., Pöschl, R., Potlog, P. M., Prasad, R., Quishpe, R., Ranken, E., Ringwald, A., Roich, A., Salgado, F., Santra, A., Sarri, G., Sävert, A., Sbrizzi, A., Schmitt, S., Schulthess, I., Schuwalow, S., Seipt, D., Simi, G., Soreq, Y., Spataro, D., Streeter, M., Swientek, K., Tal Hod, N., Teter, T., Thiebault, A., Thoden, D., Trevisani, N., Urmanov, R., Vasiukov, S., Walker, S., Warren, M., Wing, M., Yap, Y. C., Zadok, N., Zanetti, M., Żarnecki, A. F., Zbińkowski, P., Zembaczyński, K., Zepf, M., Zerwas, D., Ziegler, W., and Zuffa, M.
- Published
- 2024
- Full Text
- View/download PDF
33. Baseline Physical Activity Behaviors and Relationships with Fitness in the Army Training at High Intensity Study
- Author
-
Katie M. Heinrich, Aspen E. Streetman, Filip Kukić, Chunki Fong, Brittany S. Hollerbach, Blake D. Goodman, Christopher K. Haddock, and Walker S. C. Poston
- Subjects
exercise ,army physical fitness test ,army combat fitness test ,officers ,military ,health ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
United States Army soldiers must meet physical fitness test standards. Criticisms of the Army Physical Fitness Test (APFT) include limited testing of only aerobic and muscular endurance activity domains; yet, it is unclear what levels of aerobic and muscle strengthening activity may help predict performance in aspects of the new Army Combat Fitness Test (ACFT). This study explored relationships between baseline self-reported aerobic and muscle strengthening activities and APFT- and ACFT-related performance. Baseline participant data (N = 123) were from a cluster-randomized clinical trial that recruited active-duty military personnel (mean age 33.7 ± 5.7 years, 72.4% White, 87.0% college-educated, 81.5% Officers). An online survey was used for self-report of socio-demographic characteristics and weekly aerobic and muscle-strengthening physical activity behaviors. Participants also completed the APFT (2 min push-ups, 2 min sit-ups, 2-mile run) and ACFT-related measures (1-repetition maximum deadlift, pull-up repetitions or timed flexed arm hang, horizontal jump, and dummy drag). Bivariate logistic regression found greater aerobic and muscle-strengthening activity predicted better APFT performance, while better ACFT-related performance was predicted by greater muscle-strengthening activity. Although our data are mostly from mid-career officers, command policies should emphasize the new Holistic Health and Fitness initiative that encourages regular aerobic and muscle-strengthening physical activity for soldiers.
- Published
- 2022
- Full Text
- View/download PDF
34. Multi‐voxel pattern analysis of amygdala functional connectivity at rest predicts variability in posttraumatic stress severity
- Author
-
Jacklynn M. Fitzgerald, Emily L. Belleau, Tara A. Miskovich, Walker S. Pedersen, and Christine L. Larson
- Subjects
functional magnetic resonance imaging ,machine learning ,multi‐voxel pattern analysis ,posttraumatic stress disorder ,resting state ,trauma ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Abstract Introduction Resting state functional magnetic resonance imaging (rsfMRI) studies demonstrate that individuals with posttraumatic stress disorder (PTSD) exhibit atypical functional connectivity (FC) between the amygdala, involved in the generation of emotion, and regions responsible for emotional appraisal (e.g., insula, orbitofrontal cortex [OFC]) and regulation (prefrontal cortex [PFC], anterior cingulate cortex). Consequently, atypical amygdala FC within an emotional processing and regulation network may be a defining feature of PTSD, although altered FC does not seem constrained to one brain region. Instead, altered amygdala FC involves a large, distributed brain network in those with PTSD. The present study used a machine‐learning data‐driven approach, multi‐voxel pattern analysis (MVPA), to predict PTSD severity based on whole‐brain patterns of amygdala FC. Methods Trauma‐exposed adults (N = 90) completed the PTSD Checklist‐Civilian Version to assess symptoms and a 5‐min rsfMRI. Whole‐brain FC values to bilateral amygdala were extracted and used in a relevance vector regression analysis with a leave‐one‐out approach for cross‐validation with permutation testing (1,000) to obtain significance values. Results Results demonstrated that amygdala FC predicted PCL‐C scores with statistically significant accuracy (r = .46, p = .001; mean sum of squares = 130.46, p = .001; R2 = 0.21, p = .001). Prediction was based on whole‐brain amygdala FC, although regions that informed prediction (top 10%) included the OFC, amygdala, and dorsolateral PFC. Conclusion Findings demonstrate the utility of MVPA based on amygdala FC to predict individual severity of PTSD symptoms and that amygdala FC within a fear acquisition and regulation network contributed to accurate prediction.
- Published
- 2020
- Full Text
- View/download PDF
35. Higher resting-state BNST-CeA connectivity is associated with greater corrugator supercilii reactivity to negatively valenced images
- Author
-
Walker S. Pedersen, Stacey M. Schaefer, Lauren K. Gresham, Seungbeum D. Lee, Michael P. Kelly, Jeanette A. Mumford, Jonathan A. Oler, and Richard J. Davidson
- Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
The bed nucleus of the stria terminalis (BNST) and central nucleus of the amygdala (CeA) are hypothesized to be the output nodes of the extended amygdala threat response, integrating multiple signals to coordinate the threat response via outputs to the hypothalamus and brainstem. The BNST and CeA are structurally and functionally connected, suggesting interactions between these regions may regulate how the response to provocation unfolds. However, the relationship between human BNST-CeA connectivity and the behavioral response to affective stimuli is little understood. To investigate whether individual differences in BNST-CeA connectivity are related to the affective response to negatively valenced stimuli, we tested relations between resting-state BNST-CeA connectivity and both facial electromyographic (EMG) activity of the corrugator supercilii muscle and eyeblink startle magnitude during affective image presentation within the Refresher sample of the Midlife in the United States (MIDUS) study. We found that higher right BNST-CeA connectivity was associated with greater corrugator activity to negative, but not positive, images. There was a trend-level association between right BNST-CeA connectivity and trait negative affect. Eyeblink startle magnitude was not significantly related to BNST-CeA connectivity. These results suggest that functional interactions between BNST and CeA contribute to the behavioral response to negative emotional events.
- Published
- 2020
- Full Text
- View/download PDF
36. Cerebellar-cortical function and connectivity during sensorimotor behavior in aging FMR1 gene premutation carriers
- Author
-
Walker S. McKinney, James Bartolotti, Pravin Khemani, Jun Yi Wang, Randi J. Hagerman, and Matthew W. Mosconi
- Subjects
Fragile X-associated tremor/ataxia syndrome (FXTAS) ,Sensorimotor ,Extrastriate cortex ,Cerebellar Crus I ,Functional connectivity ,FMR1 premutation ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Introduction: Premutation carriers of the FMR1 gene are at risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disease characterized by motor, cognitive, and psychiatric decline as well as cerebellar and cerebral white matter pathology. Several studies have documented preclinical sensorimotor issues in aging premutation carriers, but the extent to which sensorimotor brain systems are affected and may represent early indicators of atypical neurodegeneration has not been determined. Materials and methods: Eighteen healthy controls and 16 FMR1 premutation carriers (including five with possible, probable, or definite FXTAS) group-matched on age, sex, and handedness completed a visually guided precision gripping task with their right hand during fMRI. During the test, they used a modified pinch grip to press at 60% of their maximum force against a custom fiber-optic transducer. Participants viewed a horizontal white force bar that moved upward with increased force and downward with decreased force and a static target bar that was red during rest and turned green to cue the participant to begin pressing at the beginning of each trial. Participants were instructed to press so that the white force bar stayed as steady as possible at the level of the green target bar. Trials were 2-sec in duration and alternated with 2-sec rest periods. Five 24-sec blocks consisting of six trials were presented. Participants’ reaction time, the accuracy of their force relative to the target force, and the variability of their force accuracy across trials were examined. BOLD signal change and task-based functional connectivity (FC) were examined during force vs. rest. Results: Relative to healthy controls, premutation carriers showed increased trial-to-trial variability of force output, though this was specific to younger premutation carriers in our sample. Relative to healthy controls, premutation carriers also showed reduced extrastriate activation during force relative to rest. FC between ipsilateral cerebellar Crus I and extrastriate cortex was reduced in premutation carriers compared to controls. Reduced Crus I-extrastriate FC was related to increased force accuracy variability in premutation carriers. Increased reaction time was associated with more severe clinically rated neurological abnormalities. Conclusions: Findings of reduced activation in extrastriate cortex and reduced Crus I-extrastriate FC implicate deficient visual feedback processing and reduced cerebellar modulation of corrective motor commands. Our results are consistent with documented cerebellar pathology and visual-spatial processing in FXTAS and pre-symptomatic premutation carriers, and suggest FC alterations of cerebellar-cortical networks during sensorimotor behavior may represent a “prodromal” feature associated with FXTAS degeneration.
- Published
- 2020
- Full Text
- View/download PDF
37. Engineering of Primary Human B cells with CRISPR/Cas9 Targeted Nuclease
- Author
-
Matthew J. Johnson, Kanut Laoharawee, Walker S. Lahr, Beau R. Webber, and Branden S. Moriarity
- Subjects
Medicine ,Science - Abstract
Abstract B cells offer unique opportunities for gene therapy because of their ability to secrete large amounts of protein in the form of antibody and persist for the life of the organism as plasma cells. Here, we report optimized CRISPR/Cas9 based genome engineering of primary human B cells. Our procedure involves enrichment of CD19+ B cells from PBMCs followed by activation, expansion, and electroporation of CRISPR/Cas9 reagents. We are able expand total B cells in culture 10-fold and outgrow the IgD+ IgM+ CD27− naïve subset from 35% to over 80% of the culture. B cells are receptive to nucleic acid delivery via electroporation 3 days after stimulation, peaking at Day 7 post stimulation. We tested chemically modified sgRNAs and Alt-R gRNAs targeting CD19 with Cas9 mRNA or Cas9 protein. Using this system, we achieved genetic and protein knockout of CD19 at rates over 70%. Finally, we tested sgRNAs targeting the AAVS1 safe harbor site using Cas9 protein in combination with AAV6 to deliver donor template encoding a splice acceptor-EGFP cassette, which yielded site-specific integration frequencies up to 25%. The development of methods for genetically engineered B cells opens the door to a myriad of applications in basic research, antibody production, and cellular therapeutics.
- Published
- 2018
- Full Text
- View/download PDF
38. Structural and mechanistic aspects influencing the ADAM10-mediated shedding of the prion protein
- Author
-
Luise Linsenmeier, Behnam Mohammadi, Sebastian Wetzel, Berta Puig, Walker S. Jackson, Alexander Hartmann, Keiji Uchiyama, Suehiro Sakaguchi, Kristina Endres, Jörg Tatzelt, Paul Saftig, Markus Glatzel, and Hermann C. Altmeppen
- Subjects
ADAM10 ,Antibody ,Exosomes ,Glycosylation ,Membrane anchor ,Neurodegeneration ,Neurology. Diseases of the nervous system ,RC346-429 ,Geriatrics ,RC952-954.6 - Abstract
Abstract Background Proteolytic processing of the prion protein (PrPC) by endogenous proteases generates bioactive membrane-bound and soluble fragments which may help to explain the pleiotropic roles of this protein in the nervous system and in brain diseases. Shedding of almost full-length PrPC into the extracellular space by the metalloprotease ADAM10 is of peculiar relevance since soluble PrP stimulates axonal outgrowth and is protective in neurodegenerative conditions such as Alzheimer’s and prion disease. However, molecular determinates and mechanisms regulating the shedding of PrP are entirely unknown. Methods We produced an antibody recognizing the neo-epitope of shed PrP generated by ADAM10 in biological samples and used it to study structural and mechanistic aspects affecting the shedding. For this, we investigated genetically modified cellular and murine models by biochemical and morphological approaches. Results We show that the novel antibody specifically detects shed PrP in cell culture supernatants and murine brain. We demonstrate that ADAM10 is the exclusive sheddase of PrPC in the nervous system and reveal that the glycosylation state and type of membrane-anchorage of PrPC severely affect its shedding. Furthermore, we provide evidence that PrP shedding can be modulated by pharmacological inhibition and stimulation and present data suggesting that shedding is a relevant part of a compensatory network ensuring PrPC homeostasis of the cell. Conclusions With the new antibody, our study introduces a new tool to reliably investigate PrP-shedding. In addition, this study provides novel and important insight into the regulation of this cleavage event, which is likely to be relevant for diagnostic and therapeutic approaches even beyond neurodegeneration.
- Published
- 2018
- Full Text
- View/download PDF
39. Muscular Strength, Power, and Endurance Adaptations after Two Different University Fitness Classes
- Author
-
Brittany S. Hollerbach, Sarah J. Cosgrove, Justin A. DeBlauw, Nattinee Jitnarin, Walker S. C. Poston, and Katie M. Heinrich
- Subjects
weight training ,resistance training ,physical education ,CrossFit ,high-intensity functional training ,college students ,Sports ,GV557-1198.995 - Abstract
Physical activity (PA) classes help college students add weekly PA, which can help improve health and maintain body weight. Traditional weight training (TWT) can improve strength and aerobic capacity. High-intensity functional training such as CrossFit® (CF) provides time-efficient workouts with both muscle strengthening and aerobic exercises. Limited research has compared these classes for college students. We examined changes in muscular strength, power, and endurance as well as body composition. Participants were 85 healthy college students enrolled in TWT (n = 36, age 22.6 ± 4.1 years, 72.2% male) or CF (n = 49, age 21.8 ± 3.2 years, 55.1% male) classes meeting twice/wk for 8 weeks between October 2017 and May 2018. Baseline and posttest measurements included a vertical jump, grip strength, a 2 min push-up test, a 1 min squat test, height, weight, and a bioelectrical impedance analysis. Although no significant group × time interactions were found, there was a significant main effect of time for push-ups and squats (both p < 0.001). Participants enjoyed the classes and most planned to continue. Both classes improved muscular endurance although no significant differences were found between them. Activity classes provide college students with an option for increasing their weekly PA and help maintain body composition. Future research should examine the benefits from longer or more frequent classes.
- Published
- 2021
- Full Text
- View/download PDF
40. Neural circuitry governing anxious individuals’ mis-allocation of working memory to threat
- Author
-
Daniel M. Stout, Alexander J. Shackman, Walker S. Pedersen, Tara A. Miskovich, and Christine L. Larson
- Subjects
Medicine ,Science - Abstract
Abstract Dispositional anxiety is a trait-like phenotype that confers increased risk for a range of debilitating neuropsychiatric disorders. Like many patients with anxiety disorders, individuals with elevated levels of dispositional anxiety are prone to intrusive and distressing thoughts in the absence of immediate threat. Recent electrophysiological research suggests that these symptoms are rooted in the mis-allocation of working memory (WM) resources to threat-related information. Here, functional MRI was used to identify the network of brain regions that support WM for faces and to quantify the allocation of neural resources to threat-related distracters in 81 young adults. Results revealed widespread evidence of mis-allocation. This was evident in both face-selective regions of the fusiform cortex and domain-general regions of the prefrontal and parietal cortices. This bias was exaggerated among individuals with a more anxious disposition. Mediation analyses provided compelling evidence that anxious individuals’ tendency to mis-allocate WM resources to threat-related distracters is statistically explained by heightened amygdala reactivity. Collectively, these results provide a neurocognitive framework for understanding the pathways linking anxious phenotypes to the development of internalizing psychopathology and set the stage for developing improved intervention strategies.
- Published
- 2017
- Full Text
- View/download PDF
41. The natural Disc1-deletion present in several inbred mouse strains does not affect sleep
- Author
-
Lars Dittrich, Alessandro Petese, and Walker S. Jackson
- Subjects
Medicine ,Science - Abstract
Abstract The gene Disrupted in Schizophrenia-1 (DISC1) is linked to a range of psychiatric disorders. Two recent transgenic studies suggest DISC1 is also involved in homeostatic sleep regulation. Several strains of inbred mice commonly used for genome manipulation experiments, including several Swiss and likely all 129 substrains, carry a natural deletion mutation of Disc1. This constitutes a potential confound for studying sleep in genetically modified mice. Since disturbed sleep can also influence psychiatric and neurodegenerative disease models, this putative confound might affect a wide range of studies in several fields. Therefore, we asked to what extent the natural Disc1 deletion affects sleep. To this end, we first compared sleep and electroencephalogram (EEG) phenotypes of 129S4 mice carrying the Disc1 deletion and C57BL/6N mice carrying the full-length version. We then bred Disc1 from C57BL/6N into the 129S4 background, resulting in S4-Disc1 mice. The differences between 129S4 and C57BL/6N were not detected in the 129S4 to S4-Disc1 comparison. We conclude that the mutation has no effect on the measured sleep and EEG characteristics. Thus, it is unlikely the widespread Disc1 deletion has led to spurious results in previous sleep studies or that it alters sleep in mouse models of psychiatric or neurodegenerative diseases.
- Published
- 2017
- Full Text
- View/download PDF
42. Precision Sensorimotor Control in Aging FMR1 Gene Premutation Carriers
- Author
-
Walker S. McKinney, Zheng Wang, Shannon Kelly, Pravin Khemani, Su Lui, Stormi P. White, and Matthew W. Mosconi
- Subjects
fragile X-associated tremor/ataxia syndrome ,FMR1 premutation ,sensorimotor ,precision grip ,neurodegeneration ,bradykinesia ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
BackgroundIndividuals with premutation alleles of the FMR1 gene are at risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative condition affecting sensorimotor function. Information on quantitative symptom traits associated with aging in premutation carriers is needed to clarify neurodegenerative processes contributing to FXTAS.Materials and Methods26 FMR1 premutation carriers ages 44–77 years and 31 age-matched healthy controls completed rapid (2 s) and sustained (8 s) visually guided precision gripping tasks. Individuals pressed at multiple force levels to determine the impact of increasing the difficulty of sensorimotor actions on precision behavior. During initial pressing, reaction time, the rate at which individuals increased their force, the duration of pressing, and force accuracy were measured. During sustained gripping, the complexity of the force time series, force variability, and mean force were examined. During relaxation, the rate at which individuals decreased their force was measured. We also examined the relationships between visuomotor behavior and cytosine-guanine-guanine (CGG) repeat length and clinically rated FXTAS symptoms.ResultsRelative to controls, premutation carriers showed reduced rates of initial force generation during rapid motor actions and longer durations of their initial pressing with their dominant hand. During sustained force, premutation carriers demonstrated reduced force complexity, though this effect was specific to younger premutation carries during dominant hand pressing and was more severe for younger relative to older premutation carriers at low and medium force levels. Increased reaction time and lower sustained force complexity each were associated with greater CGG repeat length for premutation carriers. Increased reaction time and increased sustained force variability were associated with more severe clinically rated FXTAS symptoms.ConclusionOverall our findings suggest multiple sensorimotor processes are disrupted in aging premutation carriers, including initial force control guided by feedforward mechanisms and sustained sensorimotor behaviors guided by sensory feedback control processes. Results indicating that sensorimotor issues in aging premutation carriers relate to both greater CGG repeat length and clinically rated FXTAS symptoms suggest that quantitative tests of precision sensorimotor ability may serve as key targets for monitoring FXTAS risk and progression.
- Published
- 2019
- Full Text
- View/download PDF
43. The evolution of galaxies and clusters at high spatial resolution with AXIS
- Author
-
Russell, H. R., Lopez, L. A., Allen, S. W., Chartas, G., Choudhury, P. P., Dupke, R. A., Fabian, A. C., Flores, A. M., Garofali, K., Hodges-Kluck, E., Koss, M. J., Lanz, L., Lehmer, B. D., Li, J. -T., Maksym, W. P., Mantz, A. B., McDonald, M., Miller, E. D., Mushotzky, R. F., Qiu, Y., Reynolds, C. S., Tombesi, F., Tozzi, P., Trindade-Falcao, A., Walker, S. A., Wong, K. -W., Yukita, M., and Zhang, C.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
Stellar and black hole feedback heat and disperse surrounding cold gas clouds, launching gas flows off circumnuclear and galactic disks and producing a dynamic interstellar medium. On large scales bordering the cosmic web, feedback drives enriched gas out of galaxies and groups, seeding the intergalactic medium with heavy elements. In this way, feedback shapes galaxy evolution by shutting down star formation and ultimately curtailing the growth of structure after the peak at redshift 2-3. To understand the complex interplay between gravity and feedback, we must resolve both the key physics within galaxies and map the impact of these processes over large scales, out into the cosmic web. The Advanced X-ray Imaging Satellite (AXIS) is a proposed X-ray probe mission for the 2030s with arcsecond spatial resolution, large effective area, and low background. AXIS will untangle the interactions of winds, radiation, jets, and supernovae with the surrounding ISM across the wide range of mass scales and large volumes driving galaxy evolution and trace the establishment of feedback back to the main event at cosmic noon., Comment: 29 pages, 18 figures; this white paper is part of a series commissioned for the AXIS Probe mission concept
- Published
- 2023
44. Chemical enrichment of ICM within the Ophiuchus cluster I: radial profiles
- Author
-
Gatuzz, Efrain, Sanders, J. S., Dennerl, K., Liu, A., Fabian, A. C., Pinto, C., Eckert, D., Walker, S. A., and ZuHone, J.
- Subjects
Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Cosmology and Nongalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
The analysis of the elemental abundances in galaxy clusters offers valuable insights into the formation and evolution of galaxies. In this study, we explore the chemical enrichment of the intergalactic medium (ICM) in the Ophiuchus cluster by utilizing {\it XMM-Newton} EPIC-pn observations. We explore the radial profiles of Si, S, Ar, Ca, and Fe. Due to the high absorption of the system, we have obtained only upper limits for O, Ne, Mg, and Ni. We model the X/Fe ratio profiles with a linear combination of core-collapse supernovae (SNcc) and type~Ia supernovae (SNIa) models. We found a flat radial distribution of SNIa ratio over the total cluster enrichment $10-30\%$ for all radii. However, the absence of light $\alpha$-elements abundances may lead to over-estimation of the SNcc contribution., Comment: 9 pages, 8 figures. This paper is part of a series on the ICM chemical enrichment using galaxy clusters XMM-Newton observations for which the velocity structure has been measured. Related series papers: arXiv:2302.04286, arXiv:2309.02507
- Published
- 2023
45. Chemical enrichment of ICM within the Centaurus cluster I: radial profiles
- Author
-
Gatuzz, Efrain, Sanders, J. S., Dennerl, K., Liu, A., Fabian, A. C., Pinto, C., Eckert, D., Walker, S. A., and ZuHone, J.
- Subjects
Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Cosmology and Nongalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
We examine deep {\it XMM-Newton} EPIC-pn observations of the Centaurus cluster to study the hot intracluster medium (ICM) and radial metal distributions within such an environment. We found that the best-fit spectral model corresponds to a log-normal temperature distribution, with discontinuities around $\sim10$~kpc, $\sim50$~kpc, and $\sim100$~kpc, also observed in the abundances distributions. We measured the radial profiles of O, Si, S, Ar, Ca, and Fe. These profiles reveal prominent negative gradients for distances $<90$~kpc, which then transition to flatter profiles. We modeled X/Fe ratio profiles with a linear combination of SNIcc and SNIa models. The best-fit model suggests a uniform SNIa percentage contribution to the total cluster enrichment, thus supporting an early enrichment of the ICM, with most of the metals present being produced before clustering., Comment: 8 pages, 9 figures. This paper is part of a series on the ICM chemical enrichment using galaxy clusters XMM-Newton observations for which the velocity structure has been measured. Related series papers: arXiv:2302.04286
- Published
- 2023
46. The impact of social-environmental factors on IQ in syndromic intellectual developmental disabilities
- Author
-
McKinney, Walker S, Williford, Desireé N, Abbeduto, Leonard, and Schmitt, Lauren M
- Subjects
Biological Psychology ,Cognitive and Computational Psychology ,Social and Personality Psychology ,Psychology ,Mental Health ,Behavioral and Social Science ,Intellectual and Developmental Disabilities (IDD) ,Clinical Research ,Brain Disorders ,Mental health ,Quality Education ,22q11.2 deletion syndrome ,Down syndrome ,IQ ,cognitive development ,developmental disabilities ,economic stability ,environment ,fragile x syndrome ,genetic syndrome ,home environment ,intellectual developmental disabilities ,parental stress ,social determinants of health ,social-demographic variables ,socioeconomic status ,syndromic IDD - Abstract
Despite having the same underlying genetic etiology, individuals with the same syndromic form of intellectual developmental disability (IDD) show a large degree of interindividual differences in cognition and IQ. Research indicates that up to 80% of the variation in IQ scores among individuals with syndromic IDDs is attributable to nongenetic effects, including social-environmental factors. In this narrative review, we summarize evidence of the influence that factors related to economic stability (focused on due to its prevalence in existing literature) have on IQ in individuals with syndromic IDDs. We also highlight the pathways through which economic stability is hypothesized to impact cognitive development and drive individual differences in IQ among individuals with syndromic IDDs. We also identify broader social-environmental factors (e.g., social determinants of health) that warrant consideration in future research, but that have not yet been explored in syndromic IDDs. We conclude by making recommendations to address the urgent need for further research into other salient factors associated with heterogeneity in IQ. These recommendations ultimately may shape individual- and community-level interventions and may inform systems-level public policy efforts to promote the cognitive development of and improve the lived experiences of individuals with syndromic IDDs.
- Published
- 2024
47. Upper and Lower Limb Movement Kinematics in Aging FMR1 Gene Premutation Carriers
- Author
-
Zheng Wang, Callie Lane, Matthew Terza, Pravin Khemani, Su Lui, Walker S. McKinney, and Matthew W. Mosconi
- Subjects
FMR1 gene ,fragile X−associated tremor/ataxia syndrome ,gait ,reaching ,kinematics ,cerebellum ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder associated with a premutation cytosine-guanine-guanine (CGG) trinucleotide repeat expansion of the FMR1 gene. FXTAS is estimated to be the most common single-gene form of ataxia in the aging population. Gait ataxia and intention tremor are the primary behavioral symptoms of FXTAS, though clinical evaluation of these symptoms often is subjective, contributing to difficulties in reliably differentiating individuals with FXTAS and asymptomatic premutation carriers. This study aimed to clarify the extent to which quantitative measures of gait and upper limb kinematics may serve as biobehavioral markers of FXTAS degeneration. Nineteen premutation carriers (aged 46–77 years), including 9 with possible, probable, or definite FXTAS and 16 sex- and IQ-matched healthy controls, completed tests of non-constrained walking and reaching while both standing (static reaching) and walking (dynamic reaching) to quantify gait and upper limb control, respectively. For the non-constrained walking task, participants wore reflective markers and walked at their preferred speed on a walkway. During the static reaching task, participants reached and lifted boxes of different sizes while standing. During the dynamic reaching task, participants walked to reach and lift the boxes. Movement kinematics were examined in relation to clinical ratings of neuromotor impairments and CGG repeat length. During non-constrained walking, individuals with FXTAS showed decreased stride lengths and stride velocities, increased percentages of double support time, and increased variabilities of cadence and center of mass relative to both asymptomatic premutation carriers and controls. While individuals with FXTAS did not show any static reaching differences relative to the other two groups, they showed multiple differences during dynamic reaching trials, including reduced maximum reaching velocity, prolonged acceleration time, and jerkier movement of the shoulder, elbow, and hand. Gait differences during non-constrained walking were associated with more severe clinically rated posture and gait symptoms. Reduced maximum reaching velocity and increased jerkiness during dynamic reaching were each related to more severe clinically rated kinetic dysfunction and overall neuromotor symptoms in FMR1 premutation carriers. Our findings suggest kinematic alterations consistent with gait ataxia and upper limb bradykinesia are each selectively present in individuals with FXTAS, but not asymptomatic aging premutation carriers. Consistent with neuropathological and magnetic resonance imaging (MRI) studies of FXTAS, these findings implicate cerebellar and basal ganglia degeneration associated with neuromotor decline. Our results showing associations between quantitative kinematic differences in FXTAS and clinical ratings suggest that objective assessments of gait and reaching behaviors may serve as critical and reliable targets for detecting FXTAS risk and monitoring progression.
- Published
- 2020
- Full Text
- View/download PDF
48. Moderating Effects of Harm Avoidance on Resting-State Functional Connectivity of the Anterior Insula
- Author
-
Ashley A. Huggins, Emily L. Belleau, Tara A. Miskovich, Walker S. Pedersen, and Christine L. Larson
- Subjects
functional connectivity ,harm avoidance ,anxiety ,resting-state ,personality ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
As an index of behavioral inhibition and an individual’s propensity to avoid, rather than seek, potentially dangerous situations, harm avoidance has been linked to internalizing psychopathology. Altered connectivity within intrinsic functional neural networks (i.e., default mode [DMN], central executive [CEN] and salience networks [SN]) has been related to internalizing psychopathology; however, less is known about the effects of harm avoidance on functional connectivity within and between these networks. Importantly, harm avoidance may be distinguishable from trait anxiety and have clinical relevance as a risk factor for internalizing psychopathology. A sample of young adults (n = 99) completed a resting state functional magnetic resonance imaging (fMRI) scan and self-report measures of harm avoidance and trait anxiety. Whole brain seed-to-voxel and seed-to-network connectivity analyses were conducted using anterior insula seeds to examine associations between harm avoidance/trait anxiety and connectivity. After adjusting for sex and age, there was a significant negative effect of harm avoidance on connectivity between the anterior insula and clusters in the precuneus/posterior cingulate cortex (PCC) left superior/middle frontal gyrus, dorsal anterior cingulate cortex (dACC) and bilateral inferior parietal lobule (IPL)/angular gyrus. Seed-to-network analyses indicated a negative effect of harm avoidance on connectivity between the right anterior insula and anterior and posterior DMN. There were no effects of trait anxiety on functional connectivity of the anterior insula. Overall, the results indicate that individual differences in harm avoidance relate to disruptions in internetwork connectivity that may contribute to deficits in appropriately modulating attentional focus.
- Published
- 2018
- Full Text
- View/download PDF
49. Structural Connectivity of the Posterior Cingulum Is Related to Reexperiencing Symptoms in Posttraumatic Stress Disorder
- Author
-
Carissa N. Weis, Emily L. Belleau, Walker S. Pedersen, Tara A. Miskovich, and Christine L. Larson
- Subjects
Psychiatry ,RC435-571 - Abstract
Posttraumatic stress disorder is a heterogeneous disorder with disturbances in hyperarousal or avoidance behaviors and intrusive or reexperiencing thoughts. The uncinate fasciculus and cingulum bundle are white matter pathways implicated in stress and trauma pathophysiology, yet their structural integrity related to posttraumatic stress disorder symptom domains is yet to be understood. Forty-four trauma-exposed young adults underwent structural and diffusion-weighted magnetic resonance imaging. Stress and trauma exposure indices and severity of posttraumatic stress disorder symptoms were collected and used to predict current integrity of the uncinate fasciculus and cingulum bundle. Severity of reexperiencing posttraumatic stress disorder symptoms was significantly related to increased fractional anisotropy ( r = .469 p 0.05) or avoidance ( p ’s > 0.2) posttraumatic stress disorder symptoms. The posterior cingulum connects medial temporal lobe structures with visual areas in the occipital lobe and has been implicated in visual memory and self-referential thought. Increased structural connectivity along this pathway may therefore explain the emergence of reexperiencing posttraumatic stress disorder symptoms. This along with the lack of results with respect to stress exposure suggests that structural aberrations in white matter pathways are more strongly linked with the actual experience of stress-related psychological symptoms than just exposure to stress.
- Published
- 2018
- Full Text
- View/download PDF
50. Author Correction: Highly efficient multiplex human T cell engineering without double-strand breaks using Cas9 base editors
- Author
-
Beau R. Webber, Cara-lin Lonetree, Mitchell G. Kluesner, Matthew J. Johnson, Emily J. Pomeroy, Miechaleen D. Diers, Walker S. Lahr, Garrett M. Draper, Nicholas J. Slipek, Branden A. Smeester, Klaus N. Lovendahl, Amber N. McElroy, Wendy R. Gordon, Mark J. Osborn, and Branden S. Moriarity
- Subjects
Science - Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.