Secondary Traumatic Stress and Alexithymia in High-Risk Professionals

This study investigated the role that cognitive deficits in emotional processing (i.e., alexithymia) play in the development of traumatic responses, such as secondary traumatic stress (STS), following work with clients who have experienced trauma. Using a prospective cohort of novice counselling psychology and pre-service education students, participants were measured for traits of alexithymia and STS before and after their first practicum placements. Elevated rates of STS consistent with a diagnosis of post-traumatic stress disorder were identified in participants following initial practicum placement. Correlation analyses demonstrated that alexithymia and alexithymia symptom clusters were significantly, and robustly, associated with STS and STS symptom clusters. Finally, hierarchal multiple regression analysis found that scores of alexithymia, pre-trauma exposure, predicted a significant amount of the variance in post-trauma exposure STS. Implications for identification, prevention, treatment, and destigmatization of negative emotional responses to working with clients who have experienced trauma are discussed along with future directions of study

From Observers to Participants: Joining the Scientific Community

In this essay, we have integrated the voices of our mentors and students to explore 45 years of undergraduate research experiences and their role in shaping our scientific community. In considering our collective experiences, we see undergraduate involvement in research as a rich source of community development, one that has both touched our lives and influenced our teaching

Neuroimaging Depression Risk in a Sample of Never-Depressed Children

Children of mothers with a history of depression are at significantly higher risk for developing depression themselves. Although numerous mechanisms explaining this relationship have been proposed (Goodman & Gotlib, 1999), relatively little is known about the neural substrates of never-depressed children’s depression risk. Of the few studies that have used neuroimaging techniques to characterize risk-based differences in children’s neural structure, function, and functional connectivity, most have used samples that include participants with a personal history of depression or older samples (i.e., past the typical age of onset for depressive disorders). These approaches limit what can be determined regarding whether findings are true markers of risk (and potential etiological mechanisms) or better reflect resilience to depression or brain-based sequelae of depression. There is a clear need to better characterize children’s neuroimaging-based markers of depression risk by focusing on samples with clear statistical risk (i.e., a maternal history of depression or early emerging depression symptoms) prior to their own onset of disorder. This dissertation addresses this gap in the literature by characterizing the association between a sample (Ns = 80-85) of never-depressed children’s risk for depression and magnetic resonance imaging (MRI) markers of children’s brain structure (Study 1), functional response to maternal feedback (Study 2), and resting-state functional connectivity (Study 3). Main findings included never-depressed children’s self-reported depression symptoms being negatively associated with grey matter volume in regions relevant to reward processing (i.e., orbitofrontal cortex; Study 1), functional activity in salience processing regions (i.e., anterior insula) and reward processing (i.e., putamen) during critical maternal feedback (Study 2), and resting-state functional connectivity within the Central Executive Network and Salience Network (Study 3). I also demonstrated that children with high maternal risk for depression (i.e., a maternal history of depression) had significantly increased resting-state functional connectivity within the default mode network. Results indicate that brain-based associates of depression risk (i.e., maternal history of depression and children’s depression symptoms) pre-exist the development of depression, potentially contributing to the etiology of depression. Future directions for the emerging field of neuroimaging children’s risk for depression are discussed

Spatial heterogeneity promotes coexistence of rock-paper-scissor metacommunities

The rock-paper-scissor game -- which is characterized by three strategies R,P,S, satisfying the non-transitive relations S excludes P, P excludes R, and R excludes S -- serves as a simple prototype for studying more complex non-transitive systems. For well-mixed systems where interactions result in fitness reductions of the losers exceeding fitness gains of the winners, classical theory predicts that two strategies go extinct. The effects of spatial heterogeneity and dispersal rates on this outcome are analyzed using a general framework for evolutionary games in patchy landscapes. The analysis reveals that coexistence is determined by the rates at which dominant strategies invade a landscape occupied by the subordinate strategy (e.g. rock invades a landscape occupied by scissors) and the rates at which subordinate strategies get excluded in a landscape occupied by the dominant strategy (e.g. scissor gets excluded in a landscape occupied by rock). These invasion and exclusion rates correspond to eigenvalues of the linearized dynamics near single strategy equilibria. Coexistence occurs when the product of the invasion rates exceeds the product of the exclusion rates. Provided there is sufficient spatial variation in payoffs, the analysis identifies a critical dispersal rate $d^*$ required for regional persistence. For dispersal rates below $d^*$, the product of the invasion rates exceed the product of the exclusion rates and the rock-paper-scissor metacommunities persist regionally despite being extinction prone locally. For dispersal rates above $d^*$, the product of the exclusion rates exceed the product of the invasion rates and the strategies are extinction prone. These results highlight the delicate interplay between spatial heterogeneity and dispersal in mediating long-term outcomes for evolutionary games.Comment: 31pages, 5 figure

Neural activity during self-referential processing in children at risk for depression.

ABSTRACT BACKGROUND: According to cognitive theories of depression, more negative and less positive self-schemas are thought to play a causal role in the disorder. Existing evidence speaks to the neural substrates of self-referential processes in both healthy and depressed individuals, but little is known about how the brain relates to selfreferential processing in the context of depression risk in children. We therefore studied the neural substrates of self-referential processing in never-depressed preadolescent children at high and low risk for depression based on maternal depression history. METHODS: A total of 87 never-depressed 10–12-year-old children (29 with maternal depression) completed a selfreferential encoding task during a functional magnetic resonance imaging session, in which they were presented a series of positive and negative trait adjectives and endorsed whether each word was self-descriptive. Small volume correction analyses were conducted within 7 regions of interest that are important for self-referential and emotion-related processes. RESULTS: Analyses of small volume correction indicated that high-risk children showed greater activation in the ventrolateral prefrontal cortex and ventromedial prefrontal cortex during the positive-word self-referential encoding task condition than low-risk children. Ventrolateral prefrontal cortex activation mediated the association between maternal depression and child depressive symptoms only when children had lower positive self-schemas, indicating that more positive self-schemas may protect at-risk children from developing depressive symptoms. CONCLUSIONS: Cortical midline and prefrontal regions are important to self-, emotion-, and regulation-related processes. Heightened activation within these regions in never-depressed high-risk children indicates that these neurobiological substrate

Aboveground Biomass Accumulation in a Tropical Wet Forest in Nicaragua Following a Catastrophic Hurricane Disturbance 1

Among their effects on forest structure and carbon dynamics, hurricanes frequently create large-scale canopy gaps that promote secondary growth. To measure the accumulation of aboveground biomass (AGBM) in a hurricane damaged forest, we established permanent plots 4 mo after the landfall of Hurricane Joan on the Atlantic coast of Nicaragua in October 1988. We quantified AGBM accumulation in these plots by correlating diameter measurements to AGBM values using a published allometric regression equation for tropical wet forests. In the first measurement year following the storm, AGBM in hurricane-affected plots was quite variable, ranging from 26 to 153 Mg/ha, with a mean of 78 (±15) Mg/ha. AGBM was substantially lower than in two control plots several kilometers outside the hurricane's path (331 ±15 Mg/ha). Biomass accumulation was slow (5.36 ± 0.74 Mg/ha/yr), relative to previous studies of forest regeneration following another hurricane (Hugo) and agricultural activity. We suggest that large-scale, homogenous canopy damage caused by Hurricane Joan impeded the dispersal and establishment of pioneer trees and led to a secondary forest dominated by late successional species that resprouted and survived the disturbance. With the relatively slow rate of biomass accumulation, any tightening in disturbance interval could reduce the maximum capacity of the living biomass to store carbon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73646/1/j.1744-7429.2005.00077.x.pd

Characterizing and Predicting Canadian Adolescents’ Internalizing Symptoms In The First Year Of The COVID-19 Pandemic

To date, most longitudinal studies of adolescents’ internalizing symptoms during the COVID-19 pandemic include few time points, limiting knowledge about the long-term course of adolescents’ mental health during the pandemic. Moreover, examining intraindividual variability in symptoms, which may have important implications for adolescents’ adjustment beyond mean or “typical” symptoms, requires multiple time points. We examined the course of internalizing symptoms in 271 Ontario adolescents (mean n = 193 across time points) during the first year of the pandemic (March 2020–April 2021) via mixed-effect location scale models, drawing upon established internalizing symptom risk factors as predictors of mean trends and intraindividual variability. Adolescents’ internalizing symptoms were relatively stable and generally low over the first year of the pandemic, with severity peaking in February and April 2021. Girls showed more symptoms on average and greater intraindividual variability in symptoms. Parents’ depressive symptoms predicted intraindividual variability in adolescents’ anxious and depressive symptoms. Adolescents’ symptoms were stable and generally below clinical cutoffs. However, female adolescents and those whose parents experienced more depressive symptoms were most vulnerable to the stress of the pandemic. Implications for intervention and prevention efforts are discussed

Children\u27s neural reactivity to maternal praise and criticism: Associations with early depressive symptoms and maternal depression

Caregiving experiences are implicated in children\u27s depression risk; however, children\u27s neural reactivity to positive and negative feedback from mothers, a potential mediator of depression risk, is poorly understood. In a sample of 81 children

Clusters of ant colonies and robust criticality in a tropical agroecosystem

Although sometimes difficult to measure at large scales, spatial pattern is important in natural biological spaces as a determinant of key ecological properties such as species diversity, stability, resiliency and others(1-6). Here we demonstrate, at a large spatial scale, that a common species of tropical arboreal ant forms clusters of nests through a combination of local satellite colony formation and density- dependent control by natural enemies, mainly a parasitic fly. Cluster sizes fall off as a power law consistent with a so-called robust critical state(7). This endogenous cluster formation at a critical state is a unique example of an insect population forming a non- random pattern at a large spatial scale. Furthermore, because the species is a keystone of a larger network that contributes to the ecosystem function of pest control, this is an example of how spatial dynamics at a large scale can affect ecosystem service at a local level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62598/1/nature06477.pd

THE MICHIGAN BIG WOODS RESEARCH PLOT AT THE EDWIN S. GEORGE RESERVE, PINCKNEY, MI, USA

The Michigan Big Woods research plot is a 23-ha forest dynamics research area at the Edwin S. George Reserve in Pinckney, MI, USA and is part of the Smithsonian Institution’s ForestGEO network of research stations. The plot’s freestanding woody vegetation (trees and shrubs) were censused three times, in 2003, 2008–2010, and 2014; lianas were censused on 20 ha from 2017 to 2018.http://deepblue.lib.umich.edu/bitstream/2027.42/156251/1/MP 207.pdfDescription of MP 207.pdf : Main ArticleSEL