1515 results
Direct numerical simulations of microlayer formation during heterogeneous bubble nucleation
- M. Saini, X. Chen, S. Zaleski, D. Fuster
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- Journal of Fluid Mechanics / Volume 984 / 10 April 2024
- Published online by Cambridge University Press:
- 12 April 2024, A70
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In this article, we present direct numerical simulation results for the expansion of spherical cap bubbles attached to a rigid wall due to a sudden drop in the ambient pressure. The critical pressure drop beyond which the bubble growth becomes unstable is found to match well with the predictions from classical theory of heterogeneous nucleation imposing a quasi-static bubble evolution. When the pressure drop is significantly higher than the critical value, a liquid microlayer appears between the bubble and the wall. In this regime, the interface outside the microlayer grows at an asymptotic velocity that can be predicted from the Rayleigh–Plesset equation, while the contact line evolves with another asymptotic velocity that scales with a visco-capillary velocity that obeys the Cox–Voinov law. In general, three distinctive regions can be distinguished: the region very close to the contact line where dynamics is governed by visco-capillary effects, an intermediate region controlled by inertio-viscous effects away from the contact line yet inside the viscous boundary layer, and the region outside the boundary layer dominated by inertial effects. The microlayer forms in a regime where the capillary effects are confined in a region much smaller than the viscous boundary layer thickness. In this regime, the global capillary number takes values much larger then the critical capillary number for bubble nucleation, and the microlayer height is controlled by viscous effects and not surface tension.
547 The viscous and fermentability properties of dietary fiber impact on chronic kidney disease-mineral and bone disorder
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- Annabel Biruete, Neal X. Chen, Shruthi Srinivasan, Kalisha O’Neill, Samantha Siles, Kathleen Hill Gallant, Sharon M. Moe
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- Journal:
- Journal of Clinical and Translational Science / Volume 8 / Issue s1 / April 2024
- Published online by Cambridge University Press:
- 03 April 2024, pp. 163-164
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OBJECTIVES/GOALS: Dietary fiber has been used in other clinical populations to improve mineral disorders, but there is limited data in chronic kidney disease, despite the high prevalence of mineral and bone disorder (known as CKD-MBD). Our objective was to evaluate the effect of dietary fiber based on viscosity and fermentability on CKD-MBD outcomes. METHODS/STUDY POPULATION: 22-week-old male CKD rats (mild-to-moderate CKD) were randomly assigned to receive one of four fiber treatments (10% w/w each) based on fermentability and viscosity: 1) Cellulose (-fermentability, -viscosity), 2) Inulin (+fermentability, -viscosity), 3) Psyllium husk (-fermentability, +viscosity), or 4) Pectin (+ fermentability, +viscosity). Treatments lasted 10 weeks, and rats were euthanized at 32 weeks of age (kidney failure). Rats were placed in metabolic cages for 3 consecutive days the last week before euthanasia for mineral balance. At euthanasia, blood, tibia, heart, and aorta were collected for CKD-MBD assessment. Additional tissues collected included kidneys and all intestinal segments. RESULTS/ANTICIPATED RESULTS: Our preliminary data indicates that weight trajectories and survival were similar between treatment groups. At 33 weeks of age, kidney weight index (an indirect measurement of kidney function as this animal model develops polycystic kidneys) was lower in the psyllium-treated rats compared to all of the other treatments. Plasma phosphorus was lower with Psyllium and Pectin compared to Cellulose-treated rats. Left ventricular mass index was lower in the Inulin, Psyllium, and Pectin-treated rats compared to the Cellulose-treated rats. Ongoing tissue analyses include biochemical markers of mineral and bone metabolism (parathyroid hormone, fibroblast growth factor-23, and phosphorus balance), bone parameters (dynamic histomorphometry and microCT), and cardiovascular calcification. DISCUSSION/SIGNIFICANCE: Our preliminary data indicate that dietary fiber based on fermentability and viscosity impacts CKD-MBD outcomes and may be an innovative, low-cost intervention that can be trialed in people with CKD for the prevention and treatment of CKD-MBD.
Effectiveness of a WHO self-help psychological intervention to alleviate stress among healthcare workers in the context of COVID-19 in China: a randomised controlled trial
- Jinghua Li, Rui Luo, Pengyue Guo, Dexing Zhang, Phoenix K. H. Mo, Anise M. S. Wu, Meiqi Xin, Menglin Shang, Yuqi Cai, Xu Wang, Mingyu Chen, Yiling He, Luxin Zheng, Jinying Huang, Roman Dong Xu, Joseph T. F. Lau, Jing Gu, Brian J. Hall
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- Journal:
- Epidemiology and Psychiatric Sciences / Volume 33 / 2024
- Published online by Cambridge University Press:
- 07 March 2024, e11
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Aims
To examine the effectiveness of Self-Help Plus (SH+) as an intervention for alleviating stress levels and mental health problems among healthcare workers.
MethodsThis was a prospective, two-arm, unblinded, parallel-designed randomised controlled trial. Participants were recruited at all levels of medical facilities within all municipal districts of Guangzhou. Eligible participants were adult healthcare workers experiencing psychological stress (10-item Perceived Stress Scale scores of ≥15) but without serious mental health problems or active suicidal ideation. A self-help psychological intervention developed by the World Health Organization in alleviating psychological stress and preventing the development of mental health problems. The primary outcome was psychological stress, assessed at the 3-month follow-up. Secondary outcomes were depression symptoms, anxiety symptoms, insomnia, positive affect (PA) and self-kindness assessed at the 3-month follow-up.
ResultsBetween November 2021 and April 2022, 270 participants were enrolled and randomly assigned to either SH+ (n = 135) or the control group (n = 135). The SH+ group had significantly lower stress at the 3-month follow-up (b = −1.23, 95% CI = −2.36, −0.10, p = 0.033) compared to the control group. The interaction effect indicated that the intervention effect in reducing stress differed over time (b = −0.89, 95% CI = −1.50, −0.27, p = 0.005). Analysis of the secondary outcomes suggested that SH+ led to statistically significant improvements in most of the secondary outcomes, including depression, insomnia, PA and self-kindness.
ConclusionsThis is the first known randomised controlled trial ever conducted to improve stress and mental health problems among healthcare workers experiencing psychological stress in a low-resource setting. SH+ was found to be an effective strategy for alleviating psychological stress and reducing symptoms of common mental problems. SH+ has the potential to be scaled-up as a public health strategy to reduce the burden of mental health problems in healthcare workers exposed to high levels of stress.
Generation of polarized electron beams through self-injection in the interaction of a laser with a pre-polarized plasma
- L. R. Yin, X. F. Li, Y. J. Gu, N. Cao, Q. Kong, M. Büscher, S. M. Weng, M. Chen, Z. M. Sheng
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- High Power Laser Science and Engineering / Accepted manuscript
- Published online by Cambridge University Press:
- 22 February 2024, pp. 1-7
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Misperception of peer beliefs reinforces inequitable gender norms among Tanzanian men
- David W. Lawson, Zhian Chen, Joseph A. Kilgallen, Charlotte O. Brand, Alexander M. Ishungisa, Susan B. Schaffnit, Yusufu Kumogola, Mark Urassa
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- Evolutionary Human Sciences / Volume 6 / 2024
- Published online by Cambridge University Press:
- 21 February 2024, e17
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Gender role ideology, i.e. beliefs about how genders should behave, is shaped by social learning. Accordingly, if perceptions about the beliefs of others are inaccurate this may impact trajectories of cultural change. Consistent with this premise, recent studies report evidence of a tendency to overestimate peer support for inequitable gender norms, especially among men, and that correcting apparent ‘norm misperception’ promotes transitions to relatively egalitarian beliefs. However, supporting evidence largely relies on self-report measures vulnerable to social desirability bias. Consequently, observed patterns may reflect researcher measurement error rather than participant misperception. Addressing this shortcoming, we examine men's gender role ideology using both conventional self-reported and a novel wife-reported measure of men's beliefs in an urbanising community in Tanzania. We confirm that participants overestimate peer support for gender inequity. However, the latter measure, which we argue more accurately captures men's true beliefs, implies that this tendency is relatively modest in magnitude and scope. Overestimation was most pronounced among men holding relatively inequitable beliefs, consistent with misperception of peer beliefs reinforcing inequitable norms. Furthermore, older and poorly educated men overestimated peer support for gender inequity the most, suggesting that outdated and limited social information contribute to norm misperception in this context.
Transverse magnetic field effects on the high-voltage pulsed discharge plasma in helium
- C. Chen, K. M. Rabadanov, N. A. Ashurbekov, C. Yuan, A. M. Shakhrudinov
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- Journal of Plasma Physics / Volume 90 / Issue 1 / February 2024
- Published online by Cambridge University Press:
- 21 February 2024, 905900115
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This study investigates the effect of a transverse magnetic field on high-voltage pulsed discharge in helium at a pressure of 30 Torr. A simple two-dimensional fluid model that describes the high-voltage pulsed discharge in helium in a transverse weak magnetic field (B = 0.4 T) is presented, which uses an empirical relation to account for the magnetic field. The results of using the empirical relation for the effective field agree well with the experimental results. The dynamics of discharge development in the presence of the magnetic field is also investigated. The magnetic field does not significantly affect the gas-discharge development dynamics in helium at a pressure of 30 Torr.
Assessment of coupled bilayer–cytoskeleton modelling strategy for red blood cell dynamics in flow
- V. Puthumana, P.G. Chen, M. Leonetti, R. Lasserre, M. Jaeger
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- Journal of Fluid Mechanics / Volume 979 / 25 January 2024
- Published online by Cambridge University Press:
- 22 January 2024, A44
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The red blood cell (RBC) membrane is composed of a lipid bilayer and a cytoskeleton interconnected by protein junction complexes, allowing for potential sliding between the lipid bilayer and the cytoskeleton. Despite this biological reality, it is most often modelled as a single-layer model, a hyperelastic capsule or a fluid vesicle. Another approach involves incorporating the membrane's composite structure using double layers, where one layer represents the lipid bilayer and the other represents the cytoskeleton. In this paper, we computationally assess the various modelling strategies by analysing RBC behaviour in extensional flow and four distinct regimes that simulate RBC dynamics in shear flow. The proposed double-layer strategies, such as the vesicle–capsule and capsule–capsule models, account for the fluidity and surface incompressibility of the lipid bilayer in different ways. Our findings demonstrate that introducing sliding between the layers offers the cytoskeleton a considerable degree of freedom to alleviate its elastic stresses, resulting in a significant increase in RBC elongation. Surprisingly, our study reveals that the membrane modelling strategy for RBCs holds greater importance than the choice of the cytoskeleton's reference shape. These results highlight the inadequacy of considering mechanical properties alone and emphasise the need for careful integration of these properties. Furthermore, our findings fortuitously uncover a novel indicator for determining the appropriate stress-free shape of the cytoskeleton.
Overcoming major barriers in seed ecology research in developing countries
- Fernando A. O. Silveira, Lisieux Fuzessy, Shyam S. Phartyal, Roberta L. C. Dayrell, Filip Vandelook, Jerónimo Vázquez-Ramírez, Çağatay Tavşanoğlu, Mehdi Abedi, Sershen Naidoo, Diana C. Acosta-Rojas, Si-Chong Chen, Diana M. Cruz-Tejada, Gehan Jayasuryia, Carlos A. Ordóñez-Parra, Arne Saatkamp
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- Seed Science Research / Volume 33 / Issue 3 / September 2023
- Published online by Cambridge University Press:
- 03 January 2024, pp. 172-181
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Scientists are becoming increasingly aware that disparities in opportunities for conducting and publishing research among scientists living under different socio-economic contexts have created pervasive biases and long-lasting impacts on our views of the natural world. These disparities are challenging the establishment of a global research agenda for a variety of disciplines, including seed ecology. Seed ecology has progressed enormously recently, but multiple barriers have hindered progress in the Global South where biodiversity and environmental complexity are highest. Here, we identify ten major challenges that seed ecologists from developing countries face in relation to planning, designing, conducting and publishing their research. We also propose several measures to overcome these challenges: (1) closing biodiversity knowledge shortfalls, (2) enhancing and creating long-term seed ecological networks, (3) supporting better infrastructure, (4) making fieldwork easier and safer, (5) unlocking funding opportunities, (6) promoting inclusive scientific meetings, (7) alleviating language barriers, (8) improving education, (9) shifting the notion of novelty and relevance and (10) supporting native seed markets. The authors recommend that the proposed solutions can be implemented by seed ecologists and the broader scientific community including funding agencies, research directors, journal editors and the academic publishing industry. Solutions can help mitigate multiple challenges simultaneously, thus offering a relatively inexpensive, fast and productive pathway for the development of seed ecology into a truly global research discipline that benefits scientists irrespective of their geographic location and background.
5 The Impact of Sex and Associations With Treatment Exposures on Neurocognitive Impairment in Pediatric Cancer Survivors: A report from the Childhood Cancer Survivor Study
- Rachel K Peterson, Yan Chen, Kevin Oeffinger, Yutaka Yasui, Wendy Leisenring, Gregory T Armstrong, Leslie L Robison, Rebecca M Howell, Sogol Mostoufi-Moab, Jordan Gilleland Marchak, Kevin R. Krull, Kim Edelstein
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 315-316
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Objective:
Sexual dimorphism in human brain structure and behavior is influenced by exposure to sex hormones during critical developmental periods. In children, cancer and cancer treatments may alter hormone activity and brain development, impacting neurocognitive functions.
Participants and Methods:Five-year survivors of childhood cancer (N=15,560) diagnosed at <21 years from 1970 to 1999, and 3,206 siblings from the Childhood Cancer Survivor Study completed the Neurocognitive Questionnaire (NCQ), a measure of self-reported task efficiency (TE), emotion regulation (ER), Organization, and working memory (WM). We compared rates of cognitive impairment (i.e., NCQ scores >90th percentile) in survivors and same-sex siblings, and sex differences in risk factors for cognitive impairment (i.e., treatment exposures, chronic health conditions (CHCs), cancer diagnosis, age at diagnosis) using modified Poisson regressions.
Results:Survivors were more likely to report cognitive impairment than same-sex siblings (Males: TE OR=2.3, p<.001; ER OR=1.7, p=.008; Organization OR=1.5, p=.04; WM OR=2.3, p<.001. Females: TE OR=2.6, p<.001; ER OR=1.9, p<.001; Organization OR=1.5, p=.02; WM OR=2.6, p<.001). Within survivors, females were more likely than males to report impairment in TE (OR=1.2, p=.001), ER (OR=1.5, p<.001), and WM (OR=1.2, p<.001). There were no sex differences in symptom severity in siblings (all ps>.05). Risk factors for cognitive impairment in survivors included cranial radiation dose (TE <20Gy OR=1.5, p=.008, ≥20Gy OR=2.5, p<.001; ER OR=1.5, p<.001; Organization <20 Gy OR=1.4, p<.001; < WM 20 Gy OR=1.8, p<.001, ≥20Gy OR=2.7, p<.001), presence of moderate to severe CHCs (TE 1 CHC OR=1.9, p<.001, >1 CHC OR=3.6, p<.001; ER 1 CHC OR=1.7, p<.001, >1 CHC OR=2.2, p<.001; Organization 1 CHC OR=1.5, p=.001, >1 CHC OR=2.5, p<.001; WM 1 CHC OR=1.8, p<.001, >1 CHC OR=4.1, p<.001). There were sex differences in cognitive impairment risk factors in survivors. In females, cranial radiation dose (<20 Gy TE OR=1.6, p=.02; ≥20Gy TE OR=1.4, p=.01), leukemia diagnosis (TE OR=1.4, p=.02), or diagnosis age between 3-5 years (WM OR=1.4, p=.02) conferred higher risk for cognitive impairment compared to males with the same history. Females diagnosed with Hodgkin’s lymphoma (Organization OR=0.61, p=.05) or non-Hodgkin’s lymphoma (Organization OR=0.55, p=.03) were at lower risk for cognitive impairment compared to males.
Conclusions:We found sex-specific differences in rates of, and risk factors for, neurocognitive impairment, suggesting a sex vulnerability. Future studies examining interactions between sex hormones and treatment exposures during brain development will enable tailoring treatments follow-up interventions to ensure that quality of life is maximized.
29 Associations Between Social Support and Cognitive Performance Among Persons with MS
- Caroline M. Rafizadeh, Cheyenne Smith, Michelle H. Chen, John DeLuca, Lauren Strober
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- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 545-546
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Objective:
Social support is an emerging protective factor against cognitive decline. However, the relationship between social support and cognitive functioning in the multiple sclerosis (MS) population is not well understood. The present study aimed to investigate the associations between different aspects of social support and cognitive performance among persons with MS.
Participants and Methods:A volunteer sample of 63 persons with MS (% female = 88.9, mean age = 48.16) completed measures assessing perceived levels of social support measured by the Medical Outcomes Study Support Social Survey 5-item short form (MSSS-5), and social network (social network diversity and total size of social network) measured by the Social Network Index (SNI). Cognitive functioning was assessed by a brief virtual examiner-administered neuropsychological test battery (using a teleconferencing platform), including the Rey Auditory Verbal Learning Test, Controlled Oral Word Association Test, animal naming, and the Symbol Digit Modalities Test. Participants also completed brief, self-paced, virtual cognitive tests through the testmybrain.org platform, which consisted of digit span and the Trail-Making Test. A principal component analysis (PCA) was carried out to reduce the number of neuropsychological outcomes into fewer dimensions. Multiple linear regressions were conducted to examine the associations between social support measures and cognitive performance. Regression models were adjusted by the levels of depressive symptoms (operationalized by the Chicago Multiscale Depression Inventory or the Hospital Anxiety and Depression Scale) and premorbid functioning (measured by the Test of Premorbid Functioning).
Results:A PCA reduced neuropsychological outcomes into 3 components representing cognitive domains of 1) processing speed/executive functioning, 2) verbal memory, and 3) verbal fluency / simple attention. In the unadjusted models, both perceived social support (i.e., to what extent one receives assistance from their social network) as well as total size of social network (i.e., total number of people one regularly talks to) were significant predictors of the processing speed/executive functioning component score of moderate strength, where F(1, 59) = 11.93, p = .001, β = 0.41 and F(1, 59) = 11.57, p = .001, β = 0.41, respectively. These associations were maintained after adjusting for depressive symptoms and level of premorbid functioning (F(4, 55) = 3.31, p = .003 and F(4, 55) = 3.31, p = .006, respectively). On the other hand, social network diversity (i.e., number of different types of close social relationships one has) was not a significant predictor of the processing speed/executive functioning component score (p > 0.05). None of the social support measures were significantly associated with the verbal memory and verbal fluency/simple attention component scores.
Conclusions:Greater social support (specifically, perceived levels of assistance and total size of social network) is associated with better performance on processing speed/executive functioning measures among persons with MS, independent of effects from depressive symptoms and premorbid functioning. Maintaining a strong social support network may be an important factor in optimizing cognitive health in MS.
74 Timed Motor Performance in Children Medically Cleared for Return to Activities Post Mild Traumatic Brain Injury
- Tyler A Busch, Adrian M Svingos, Hsuan-Wei Chen, Kayla Huntington, Nishta Amin, Beth S Slomine, Stacy J Suskauer
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 177-178
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Objective:
Children who sustain a mild traumatic brain injury (mTBI) are at increased odds of additive injury and continue to show altered motor performance relative to never-injured peers after being medically cleared (MC) to return to normal activities. There is a critical need to determine when children can return to activities without risk of short and long-term adverse effects, with research showing high reinjury rates for 3-12 months after RTP. The Physical and Neurological Examination for Subtle Signs (PANESS) measures subtle signs of motor impairment during gait, balance, and timed motor functions. Recent literature has demonstrated that PANESS timed motor function can distinguish between children medically cleared post-mTBI compared to never-injured controls. The present study examined performance on timed motor tasks in youth medically cleared from mTBI following medical clearance and 3-months later, compared to never-injured peers.
Participants and Methods:25 children (Mage=14.16, SD=2.46; Male=68%) were enrolled within 6 weeks of medical clearance from mTBI (Mdays post MC=33, SD=13.4, Range=2-59) along with 66 typically developing, never-injured controls (Mage=13.9, SD=2.22; Male=50%). Group differences were evaluated for the Timed Motor section of the PANESS at enrollment and at a 3-month follow-up (Mdays from enrollment to follow-up=95.90, SD=12.69, Range=62-129). This 3-month follow-up occurred on average 4 months after medical clearance (Mdays from MC to follow-up=130.08, SD=17.58, Range=92 - 164). The Timed Motor section includes Repetitive (foot tapping, hand patting, and finger tapping) and Sequential (heel-toe rocking, hand pronate/supinate, finger sequencing) raw time scores, measured in seconds. The Total Timed Motor Speed score is the combination of Repetitive and Sequential Movement and the side-to-side tongue item.
Results:At 3-month follow-up, mTBI participants (M=67.55, SD=8.26, Range=53.66-83.88) performed worse than controls (M=63.09, SD=10.23, Range=39.86-100.51) on Total Timed Motor Speed, t(89)= 1.95, p<0.05), including when controlling for age and sex, F(1, 87)=4.67, p<0.05. At the same time point, mTBI participants (M=36.54, SD=5.47, Range=28.74-49.17) performed worse on Sequential Speed than controls (M=32.93, SD=6.1, Range=21.49-56.76), t(89)=2.59, p<0.01, including when controlling for age and sex, F(1, 87)=7.687, p<0.01). Although groups performed similarly on Sequential Speed at the initial time point, mTBI participants exhibited a trend of less improvement from initial to follow-up (MmTBI=-1.69, Mcontrol=-3.68, t(90)=1.445, p=0.076).
Conclusions:Although groups did not significantly differ on Timed Motor Speed items at the initial time point, the mTBI group showed consistently lower scores than controls at both time points and less improvement over time. Results indicate that Total Timed Motor Speed, specifically Sequential Speed, may be a sensitive marker of persisting differences in high-level motor and cognitive learning/control in children who have been medically cleared after mTBI. More data are needed to evaluate these findings over a longer time period, and future studies should examine behavioral markers concurrently with physiologic brain recovery over time.
94 Equivalence of In-person and Virtual Administration of the Delis-Kaplan Executive Function System’s Color-Word Interference Subtest in Youth Recovered from Concussion and Controls
- Nishta R Amin, Tyler A Busch, Kayla B Huntington, Isaac H Chen, Beth S Slomine, Stacy J Suskauer, Adrian M Svingos
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 496-497
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Objective:
Virtual testing can reduce cost and burdens, as well as increase access to clinical care. Few studies have examined the equivalency of virtual and in-person administration of standardized measures of executive functioning in children. During the COVID-19 pandemic, we utilized virtual administration of the Delis-Kaplan Executive Function System, Color-Word Interference Test (DKEFS-CW) in our ongoing longitudinal research study exploring outcomes in children clinically recovered from concussion compared to never-concussed peers. In the current study, we explore the equivalence of scores obtained via in-person and virtual administration of the DKEFS-CW in youth recovered from concussion and never-concussed controls.
Participants and Methods:Participants included 112 youth ages 10-18 (Mage=14.05 years, SD=2.296; 53.5 % Male) who completed the DKEFS-CW in-person (n=63) or virtually (n=49) as part of their involvement in the parent study. Of these, 38 were recovered from concussion (Mdays since injury— 91.21, SD=88.91), and 74 were never-injured controls. Virtual administration was done via Zoom by presenting digital scans of the DKEFS stimulus book using the screen-sharing function. Participants set up and joined the Zoom call from a secondary device (cell phone) that was set in a stable position to provide a view of their screen, mouse and keyboard setup. Group (in-person vs remote) differences in DKEFS-CW scores were examined using independent-samples t-tests for all subtest conditions (color naming, word reading, inhibition, and inhibition/switching). T-tests/chi-square tests were used to examine between-group differences in demographic variables (i.e., age, sex maternal education, IQ, concussion history). Demographic variables that were significantly different by group were then included as covariates in ANCOVA models examining the effect of administration context on performance.
Results:There were no significant differences in DKEFS-CW scaled scores between those who were administered the measure in-person or virtually (Color Naming: Min-person=10.78, Mvirtual=10.08, t(110)=1.634, p=.105; Word Reading: Min-person=11.25, Mvirtual=10.92, t(110)=.877, p=.382; Inhibition: M in-person= 11.70, Mvirtual=11.24, t(110)=1.182, p=.240; Inhibition/Switching: Mi n-person= 11.29, Mvirtual=10.82, t(110)=1.114, p=.268). There were no significant between-group differences in concussion history, sex, maternal education or IQ. However, those who were administered the DKEFS-CW in-person (Mage=13.55) were significantly younger than those who were administered the measure virtually (Mage=14.69), t(110)=-2.777, p=.006. After controlling for age, there remained no significant relationship between administration context (in-person vs. virtual) and DKEFS-CW performance for any subtest condition (Color Naming: F(1,30)=.016, p=.889; Word Reading: F(1,76)=.655, p=.421; Inhibition: F(1,30)=.038, p=.847; Inhibition/Switching: F(1,30)=.015, p=.902).
Conclusions:The recommended practice for remote administration of DKEFS-CW is to have test stimuli presented flat on a table by a trained facilitator present with the examinees. Here, we provide preliminary evidence of equivalence between DKEFS-CW scores from tests completed in-person and those completed virtually with stimuli presented on a computer screen. Future studies are needed to replicate these findings in clinical populations with greater variability in executive function. Some clinical populations may also require more in-person support. Likewise, future studies may examine the role of trained facilitators or caregivers in the virtual testing process.
78 The Effects of Hypertension and Obstructive Sleep Apnea on Auditory Learning and Memory in Veterans with PTSD Symptomology
- Valerie Z. Alipio Jocson, Julie Gretler, Marcel Chen, Jerome A. Yesavage, Lisa M. Kinoshita
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- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 586-587
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Objective:
Obstructive sleep apnea (OSA) has been associated with cognitive deficits as evidenced by neuropsychological testing in the domains of attention/working memory, verbal memory, processing speed, and executive function. OSA is often comorbid with hypertension and has been considered a risk factor for hypertension (Kareem et al., 2018; Tietjens et al., 2019). Both hypertension and OSA have been shown to be independent predictors of memory (Kinoshita et al., 2012). OSA and posttraumatic stress disorder (PTSD) are also frequently co-occurring, especially among veterans. In a group of veterans with a history of PTSD, we seek to explore the effects of sleep apnea and hypertension on cognitive functioning, particularly auditory learning/memory.
Participants and Methods:One hundred and three male and female participants with comorbid OSA and PTSD symptomology were screened as part of a larger VA Palo Alto Health Care System study. Participants (age: x=56.3, a=13.8, 24-81 years; education: x=14.6, a=2.3, 8-20 years; 9.6% female, 89.6% male) completed a neuropsychological battery, including the CVLT-II and WMS-IV Logical Memory. Presence or absence of hypertension was dichotomously coded and AHI severity was categorically coded. An auditory learning/memory composite variable was created using the z-score transformation method (Dodge et al., 2020). Variables and covariates were entered into a hierarchical regression.
Results:The initial regression model revealed hypertension and OSA severity to be independent predictors of performance on auditory learning/memory (hypertension: ß= -0.71, p<0.01; OSA: ß= -0.42, p<0.01), where presence of hypertension or increased severity of OSA resulted in worse performance on the auditory learning/memory composite.
Conclusions:Results suggest that hypertension and OSA may independently and negatively affect performance on measures of auditory learning/memory in veterans with PTSD symptomology and OSA. Such findings underscore the importance of assessing and treating both hypertension and OSA among veterans with PTSD to improve not only physical health, but also cognitive health. Further research demonstrating similar findings is recommended along with studies investigating whether or not the treatment of hypertension and OSA can improve auditory learning/memory.
3 Harmonized Memory and Language Function in the Harmonized Cognitive Assessment Protocol (HCAP) Across the United States and Mexico
- Miguel Arce Rentería, Emily M Briceño, Diefei Chen, Joseph Saenz, Jet M. J. Vonk, Lindsay Kobayashi, Chris Gonzalez, Rich Jones, Rebeca Wong, Kenneth M Langa, David R Weir, Jennifer J Manly, Alden L Gross
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- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 87-88
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Objective:
Cross-national neuropsychological research is needed to understand the social, economic, and cultural factors associated with cognitive risk and resilience across global aging populations. Memory and language have been shown to be sensitive to age-related cognitive decline and pathological cognitive aging processes and may be more sensitive to subtle cognitive decline than measures of global cognitive function. Thus, we aimed to derive and validate harmonized cognitive domain scores for memory and language across population-based studies in the US and Mexico.
Participants and Methods:Data came from the Health and Retirement Study (HRS) Harmonized Cognitive Assessment Protocol (HCAP) and the Mexican Health and Aging Study (MHAS) Ancillary Study on Cognitive Aging (Mex-Cog). We used confirmatory factor analysis methodology to create statistically co-calibrated cognitive domains of memory and language. We performed differential item functioning (DIF) analysis to evaluate measurement differences across studies, using a cultural neuropsychological approach to identify comparable items across studies (i.e., cross-study anchors). We evaluated harmonized scores by examining their relationship to age and education in each study.
Results:We included 3347 participants from the HRS-HCAP study [Mage=76.6(7.5), 60% female] and 2042 participants from the Mex-Cog study [Mage=68.1(9.0), 59% female]. Education was classified according to the International Standard Classification of Education in the following categories (HRS-HCAP and Mex-Cog, respectively): none or early childhood education: (0.7%; 50.5%), primary education (4.1%; 22.3%), lower secondary education (7.1%; 15.7%), upper secondary education (41.1%; 3.0%), and any college (47.1%; 8.5%). DIF analyses revealed that 5 out of the 7 memory items and 1 out of the 12 language items demonstrated statistical evidence of measurement differences across studies, meaning that these items measured each underlying cognitive construct differently across studies. After adjusting for DIF by not allowing the items with DIF to be cross-study anchors, harmonized memory and language scores showed generally the expected associations with age and education in each study. Increasing age was associated with lower memory (r=-0.40 in HRS-HCAP; r=-0.44 in Mex-Cog) and language (r=-0.31 in HRS-HCAP and r=-0.67 in Mex-Cog) scores. Increasing years of education was associated with better memory and language scores, with mean scores ranging from z=-0.86 and z=-0.29 among those with a primary education or lower to z=0.33 and z=0.90 among those with any college, for HRS-HCAP and Mex-Cog, respectively.
Conclusions:A cultural neuropsychology approach to statistical harmonization facilitates the generation of harmonized measures of cognitive functioning in cross-national studies. Future work can utilize these harmonized cognitive scores to investigate determinants of late-life cognitive decline and dementia in the US and Mexico.
4 Misinterpreting cognitive change over multiple timepoints: When practice effects meet age-related decline
- Mark Sanderson-Cimino, Ruohui Chen, Xin M Tu, Jeremy A Elman, Amy J Jak, William S Kremen
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 673-674
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Objective:
Practice effects (PE) on cognitive testing impede our ability to accurately assess change. In particular, they hamper the detection of mild cognitive impairment (MCI) and progression to dementia by delaying the point at which test scores fall below diagnostic impairment cutoffs. When decline over time is expected, as with older adults or progressive diseases, failure to adequately address PEs may lead to inaccurate conclusions because PEs artificially boost scores while pathology-related or age-related decline reduces scores. The participant-replacement method accounts for PEs by comparing performance of demographically-matched replacement participants to returnees who have been tested previously. Unlike most methods, the participant-replacement method can separate pathology- or age-related decline from PEs; however, this method has only been used across two timepoints. Neuropsychologists tend to think that PEs level out after the first follow-up, but this issue has not been evaluated in models that allow PEs in the presence of overall decline. Including more than two timepoints makes it possible to determine if PEs level out after the first follow-up, but it is analytically challenging because individuals may not be assessed at every timepoint.
Participants and Methods:We examined 1190 older adults in the Alzheimer’s Disease Neuroimaging Initiative who were cognitively unimpaired (n=809) or had MCI (n=381) at baseline. Participants completed six neuropsychological measures (Trails A, Trials B, Boston Naming Test, Category Fluency, Logical Memory, Rey Auditory Verbal Learning Task) at three timepoints (baseline, 12-month, 24-month). We implemented the participant-replacement method using generalized estimating equations in comparisons of matched returnees and replacements to calculate PEs. Propensity scores matched individuals on age, education, sex, and an estimate of premorbid functioning. Generalized estimating equations modeled PEs and age-related decline separately for each cognitive measure.
Results:We observed significant PEs for 5 of the 6 measures in the cognitively unimpaired group and 4 measures in the baseline MCI group. PEs did not uniformly decrease across time; some—specifically on episodic memory measures—continued to increase beyond the first follow-up for both groups of participants. Without accounting for PEs, cognitive function appeared to improve or stay the same. In contrast, when PEs were included in the models, cognitive function appeared to decline or stay the same across time.
Conclusions:The replacement method of PE adjustment revealed significant PEs across two follow-ups. PEs for episodic memory, in particular, did not level out, but actually increased after the first follow-up, two years after baseline. As expected in these older adults, accounting for PEs revealed cognitive decline, in some cases, even when PE-unadjusted scores improved. This method of assessing PEs, in turn, means earlier detection of cognitive deficits, including progression to MCI, and more accurate characterization of longitudinal change.
58 Cognitive and Brain Reserve Predict a Decline in Adverse Driving Behaviors Among Cognitively Normal Older Adults
- Samantha A Murphy, Ling Chen, Jason M Doherty, Prerana Acharyya, Noah Riley, Ann M Johnson, Alexis Walker, Hailee Domash, Maren Jorgenson, Ganesh M Babulal
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 365-366
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Objective:
Daily driving behavior is ultimate measure of cognitive functioning requiring multiple cognitive domains working synergistically to complete this complex instrumental activity of daily living. As the world’s population continues to grow and age older, motor vehicle crashes become more frequent. Cognitive and brain reserve are developing constructs that are frequently assessed in aging research. Cognitive reserve preserves functioning in the face of greater loss of brain structure as experienced during cognitive impairment or dementia. This study determined whether cognitive reserve and brain reserve predict changes in adverse driving behaviors in cognitively normal older adults.
Participants and Methods:Cognitively normal participants (Clinical Dementia Rating 0) were enrolled from longitudinal studies at the Knight Alzheimer’s Disease Research Center at Washington University. Participants (n=186) were ≥ 65 years of age, required to have Magnetic Resonance Imaging (MRI) data, neuropsychological testing data, as well as one full year of naturalistic driving data prior to the beginning of COVID-19 lockdown in the United States (March 2020). Naturalistic driving behavior data was collected via the Driving Real World In-vehicle Evaluation System (DRIVES). DRIVES variables included idle time, over speeding, aggression, number of trips, including those at day and night. MRI was performed on 3T Tesla using a research imaging protocol based upon ADNI that includes a high-resolution T1 MPRAGE for assessment of brain structures to produce normalized whole brain volume (WBV) and hippocampal volume (HV). WBV and HV were each assessed using tertiles comparing the top 66% with the bottom 33% where the bottom represented increased atrophy. The Word Reading subtest of the Wide Range Achievement Test 4 (WRAT 4) was utilized as a proxy for cognitive reserve. WRAT 4 scores were compared with the top 66% and the bottom 33% where the bottom were poor performers. Linear-mixed-effect models adjusted for age, education, and sex.
Results:Participants on average were older (73.7±4.9), college educated (16.6±2.2), and similar sex distribution (males=100, females=86). Analyses showed statistically significant differences in slopes where participants with increased hippocampal and whole brain atrophy were less likely to overspeed (p=0.0035; p=0.0003), drive aggressively (p=0.0016; p<0.0001), and drive during the daytime (p<0.0001; p<0.0001). However, they were more likely to spend more time idling (p=0.0005; p<0.0001) and drive during the nighttime (p=0.003; p=0.0002). Similar findings occurred with the WRAT 4 where participants with lower scores were less likely to overspeed (p=0.0035), drive aggressively (p=0.0024), hard brake (p=0.0180), and drive during the daytime (p<0.0001) while they were more likely to also spend more time idling (p=0.0012) and drive during the nighttime (p=0.0004).
Conclusions:Numerous changes in driving behaviors over time were predicted by increased hippocampal and whole brain atrophy as well as lower cognitive reserve scores proxied by the WRAT 4. These changes show that those with lower brain and cognitive reserve are more likely to restrict their driving behavior and adapt their daily behaviors as they age. These results suggest older adults with lower brain and cognitive reserve are more likely to avoid highways where speeding and aggressive maneuvers are more frequent.
Conjugated hyperbilirubinemia is associated with increased morbidity and mortality after neonatal heart surgery
- Mallory Hunt, Iris E.M. de Jong, Rebecca G. Wells, Amit A. Shah, Pierre Russo, Marlene Mahle, Monique M. Gardner, Stephanie Fuller, Jonathan Chen, J. William Gaynor
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- Journal:
- Cardiology in the Young , First View
- Published online by Cambridge University Press:
- 18 December 2023, pp. 1-8
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Background:
Cholestasis characterised by conjugated hyperbilirubinemia is a marker of hepatobiliary dysfunction following neonatal cardiac surgery. We aimed to characterise the incidence of conjugated hyperbilirubinemia following neonatal heart surgery and examine the effect of conjugated hyperbilirubinemia on post-operative morbidity and mortality.
Methods:This was a retrospective study of all neonates who underwent surgery for congenital heart disease (CHD) at our institution between 1/1/2010 and 12/31/2020. Patient- and surgery-specific data were abstracted from local registry data and review of the medical record. Conjugated hyperbilirubinemia was defined as perioperative maximum conjugated bilirubin level > 1 mg/dL. The primary outcome was in-hospital mortality. Survival analysis was conducted using the Kaplan–Meier survival function.
Results:Conjugated hyperbilirubinemia occurred in 8.5% of patients during the study period. Neonates with conjugated hyperbilirubinemia were more likely to be of younger gestational age, lower birth weight, and non-Caucasian race (all p < 0.001). Patients with conjugated hyperbilirubinemia were more likely to have chromosomal and non-cardiac anomalies and require ECMO pre-operatively. In-hospital mortality among patients with conjugated hyperbilirubinemia was increased compared to those without (odds ratio 5.4). Post-operative complications including mechanical circulatory support, reoperation, prolonged ventilator dependence, and multi-system organ failure were more common with conjugated hyperbilirubinemia (all p < 0.04). Patients with higher levels of conjugated bilirubin had worst intermediate-term survival, with patients in the highest conjugated bilirubin group (>10 mg/dL) having a 1-year survival of only 6%.
Conclusions:Conjugated hyperbilirubinemia is associated with post-operative complications and worse survival following neonatal heart surgery. Cholestasis is more common in patients with chromosomal abnormalities and non-cardiac anomalies, but the underlying mechanisms have not been delineated.
Ten New Insights in Climate Science 2023/2024
- Mercedes Bustamante, Joyashree Roy, Daniel Ospina, Ploy Achakulwisut, Anubha Aggarwal, Ana Bastos, Wendy Broadgate, Josep G. Canadell, Edward R. Carr, Deliang Chen, Helen A. Cleugh, Kristie L. Ebi, Clea Edwards, Carol Farbotko, Marcos Fernández-Martínez, Thomas L. Frölicher, Sabine Fuss, Oliver Geden, Nicolas Gruber, Luke J. Harrington, Judith Hauck, Zeke Hausfather, Sophie Hebden, Aniek Hebinck, Saleemul Huq, Matthias Huss, M. Laurice P. Jamero, Sirkku Juhola, Nilushi Kumarasinghe, Shuaib Lwasa, Bishawjit Mallick, Maria Martin, Steven McGreevy, Paula Mirazo, Aditi Mukherji, Greg Muttitt, Gregory F. Nemet, David Obura, Chukwumerije Okereke, Tom Oliver, Ben Orlove, Nadia S. Ouedraogo, Prabir K. Patra, Mark Pelling, Laura M. Pereira, Åsa Persson, Julia Pongratz, Anjal Prakash, Anja Rammig, Colin Raymond, Aaron Redman, Cristobal Reveco, Johan Rockström, Regina Rodrigues, David R. Rounce, E. Lisa F. Schipper, Peter Schlosser, Odirilwe Selomane, Gregor Semieniuk, Yunne-Jai Shin, Tasneem A. Siddiqui, Vartika Singh, Giles B. Sioen, Youba Sokona, Detlef Stammer, Norman J. Steinert, Sunhee Suk, Rowan Sutton, Lisa Thalheimer, Vikki Thompson, Gregory Trencher, Kees van der Geest, Saskia E. Werners, Thea Wübbelmann, Nico Wunderling, Jiabo Yin, Kirsten Zickfeld, Jakob Zscheischler
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- Journal:
- Global Sustainability / Accepted manuscript
- Published online by Cambridge University Press:
- 01 December 2023, pp. 1-58
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Outcomes after initial heart failure consultation in Fontan patients
- Sharon Chen, Muhammad F. Shezad, Angela Lorts, Amanda D. McCormick, Chad Y. Mao, Kathleen E. Simpson, Matthew J. O’Connor, Aliessa Barnes, Adam M. Lubert, Chesney Castleberry, Julie Schmidt, Katie Schroeder, Anna Joong, David W. Bearl, Ashwin K. Lal, Deepa Mokshagundam, Jennifer Conway, Ari Cedars, Kurt R. Schumacher
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- Journal:
- Cardiology in the Young , First View
- Published online by Cambridge University Press:
- 28 November 2023, pp. 1-8
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Background:
Patients with Fontan failure are high-risk candidates for heart transplantation and other advanced therapies. Understanding the outcomes following initial heart failure consultation can help define appropriate timing of referral for advanced heart failure care.
Methods:This is a survey study of heart failure providers seeing any Fontan patient for initial heart failure care. Part 1 of the survey captured data on clinical characteristics at the time of heart failure consultation, and Part 2, completed 30 days later, captured outcomes (death, transplant evaluation outcome, and other interventions). Patients were classified as “too late” (death or declined for transplant due to being too sick) and/or “care escalation” (ventricular assist device implanted, inotrope initiated, and/or listed for transplant), within 30 days. “Late referral” was defined as those referred too late and/or had care escalation.
Results:Between 7/2020 and 7/2022, 77 Fontan patients (52% inpatient) had an initial heart failure consultation. Ten per cent were referred too late (6 were too sick for heart transplantation with one subsequent death, and two others died without heart transplantation evaluation, within 30 days), and 36% had care escalation (21 listed ± 5 ventricular assist device implanted ± 6 inotrope initiated). Overall, 42% were late referrals. Heart failure consultation < 1 year after Fontan surgery was strongly associated with late referral (OR 6.2, 95% CI 1.8–21.5, p=0.004).
Conclusions:Over 40% of Fontan patients seen for an initial heart failure consultation were late referrals, with 10% dying or being declined for transplant within a month of consultation. Earlier referral, particularly for those with heart failure soon after Fontan surgery, should be encouraged.
Reciprocal relationships between stress and depressive symptoms: the essential role of the nucleus accumbens
- Yizhou Ma, Peter Kochunov, Mark D. Kvarta, Tara LeGates, Bhim M. Adhikari, Joshua Chiappelli, Andrew van der Vaart, Eric L. Goldwaser, Heather Bruce, Kathryn S. Hatch, Si Gao, Shuo Chen, Ann Summerfelt, Thomas E. Nichols, L. Elliot Hong
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- Journal:
- Psychological Medicine / Volume 54 / Issue 5 / April 2024
- Published online by Cambridge University Press:
- 26 September 2023, pp. 1045-1056
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Background
Stress and depression have a reciprocal relationship, but the neural underpinnings of this reciprocity are unclear. We investigated neuroimaging phenotypes that facilitate the reciprocity between stress and depressive symptoms.
MethodsIn total, 22 195 participants (52.0% females) from the population-based UK Biobank study completed two visits (initial visit: 2006–2010, age = 55.0 ± 7.5 [40–70] years; second visit: 2014–2019; age = 62.7 ± 7.5 [44–80] years). Structural equation modeling was used to examine the longitudinal relationship between self-report stressful life events (SLEs) and depressive symptoms. Cross-sectional data were used to examine the overlap between neuroimaging correlates of SLEs and depressive symptoms on the second visit among 138 multimodal imaging phenotypes.
ResultsLongitudinal data were consistent with significant bidirectional causal relationship between SLEs and depressive symptoms. In cross-sectional analyses, SLEs were significantly associated with lower bilateral nucleus accumbal volume and lower fractional anisotropy of the forceps major. Depressive symptoms were significantly associated with extensive white matter hyperintensities, thinner cortex, lower subcortical volume, and white matter microstructural deficits, mainly in corticostriatal-limbic structures. Lower bilateral nucleus accumbal volume were the only imaging phenotypes with overlapping effects of depressive symptoms and SLEs (B = −0.032 to −0.023, p = 0.006–0.034). Depressive symptoms and SLEs significantly partially mediated the effects of each other on left and right nucleus accumbens volume (proportion of effects mediated = 12.7–14.3%, p < 0.001−p = 0.008). For the left nucleus accumbens, post-hoc seed-based analysis showed lower resting-state functional connectivity with the left orbitofrontal cortex (cluster size = 83 voxels, p = 5.4 × 10−5) in participants with high v. no SLEs.
ConclusionsThe nucleus accumbens may play a key role in the reciprocity between stress and depressive symptoms.