803 research outputs found
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 childrenâs depression risk. Of the few studies that have used neuroimaging techniques to characterize risk-based differences in childrenâs 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 childrenâs 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 childrenâs risk for depression and magnetic resonance imaging (MRI) markers of childrenâs brain structure (Study 1), functional response to maternal feedback (Study 2), and resting-state functional connectivity (Study 3). Main findings included never-depressed childrenâs 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 childrenâs depression symptoms) pre-exist the development of depression, potentially contributing to the etiology of depression. Future directions for the emerging field of neuroimaging childrenâs risk for depression are discussed
Anolis lizards as biocontrol agents in mainland and island agroecosystems
Our knowledge of ecological interactions that bolster ecosystem function and productivity has broad applications to the management of agricultural systems. Studies suggest that the presence of generalist predators in agricultural landscapes leads to a decrease in the abundance of herbivorous pests, but our understanding of how these interactions vary across taxa and along gradients of management intensity and ecoâgeographic space remains incomplete. In this study, we assessed the functional response and biocontrol potential of a highly ubiquitous insectivore (lizards in the genus Anolis) on the worldâs most important coffee pest, the coffee berry borer (Hypothalemus hampei). We conducted field surveys and laboratory experiments to examine the impact of landâuse intensification on species richness and abundance of anoles and the capacity of anoles to reduce berry borer infestations in mainland and island coffee systems. Our results show that anoles significantly reduce coffee infestation rates in laboratory settings (Mexico, p = .03, F = 5.13 df = 1, 35; Puerto Rico, p = .014, F = 8.82, df = 1, 10) and are capable of consuming coffee berry borers in high abundance. Additionally, diversified agroecosystems bolster anole abundance, while highâintensity practices, including the reduction of vegetation complexity and the application of agrochemicals were associated with reduced anole abundance. The results of this study provide supporting evidence of the positive impact of generalist predators on the control of crop pests in agricultural landscapes, and the role of diversified agroecosystems in sustaining both functionally diverse communities and crop production in tropical agroecosystems.The focus of this project was to assess the predatory function of wildlife in tropical coffee agroecosystems (i.e. pest reduction by a generalist insectivore), and the relative impacts of landâuse intensification on species abundance in mainland and island settings. The results of this study are the first to provide evidence that lizards in the genus Anolis are capable of both consuming the coffee berry borer in high numbers and significantly reducing infestations in laboratory settings. Our results show that anole presence is bolstered by vegetative complexity, and significantly reduced by high intensity practices including the application of agrochemicals.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136386/1/ece32806.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136386/2/ece32806_am.pd
Characterizing and Predicting Canadian Adolescentsâ Internalizing Symptoms In The First Year Of The COVID-19 Pandemic
To date, most longitudinal studies of adolescentsâ internalizing symptoms during the COVID-19 pandemic include few time points, limiting knowledge about the long-term course of adolescentsâ mental health during the pandemic. Moreover, examining intraindividual variability in symptoms, which may have important implications for adolescentsâ adjustment beyond mean or âtypicalâ 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 2020âApril 2021) via mixed-effect location scale models, drawing upon established internalizing symptom risk factors as predictors of mean trends and intraindividual variability. Adolescentsâ 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. Parentsâ depressive symptoms predicted intraindividual variability in adolescentsâ anxious and depressive symptoms. Adolescentsâ 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
Fragmenting Forests: The Double Edge of Effective Forest Monitoring
The link between ineffective forest monitoring and forest degradation is well known. Under REDD+, monitoring stands to become more important as a means of maintaining incentive. Little attention however has been paid to the possible adverse consequences of forest monitoring. Our research develops a spatially explicit, agent-based model (ABM) of timber extraction in a Congo Basin forest concession to investigate the potential conservation impact of more effective monitoring. We modeled the building of access roads, and logging of legal timber and illegal timber, where illegal timber may be interpreted broadly to include prohibited species, smaller trees, or trees in areas where cutting is not permitted. We investigated road building under (1) random spot monitoring of logging sites and (2) monitoring of logged trunks at checkpoints. Our findings indicate that although more effective monitoring can reduce illegal harvesting, it can also lead to construction of denser road networks and higher levels of forest fragmentation, with an implied loss of biodiversity. These insights are particularly relevant in the context of REDD+, as they suggest that some monitoring strategies may lead to more forest fragmentation, even as they help reduce emissions
Orbitofrontal cortex grey matter volume is related to children\u27s depressive symptoms
© 2020 The Author(s) Adults with a history of depression show distinct patterns of grey matter volume (GMV) in frontal cortical (e.g., prefrontal cortex, orbitofrontal cortex) and limbic (e.g., anterior cingulate, amygdala, hippocampus, dorsal striatum) structures, regions relevant to the processing and regulation of reward, which is impaired in the context of depression. However, it is unclear whether these GMV associations with depression precede depressive disorder onset or whether GMV is related to early emerging symptoms or familial depression. To address these questions, we used voxel-based morphometry (VBM) to examine GMV in 85 community-dwelling children (M = 11.12 years, SD = 0.63 years) screened for current and lifetime depression. Associations between children\u27s depressive symptoms (self- and mother-report of children\u27s symptoms), children\u27s maternal depression history, and GMV were examined. Although maternal depression history was unrelated to children\u27s GMV, child GMV in the orbitofrontal cortex (OFC) was negatively related to children\u27s self-reported depressive symptoms, using both a priori ROI and whole-brain analyses. Moderated regression analyses indicated that girlsâ GMV was negatively related to girlsâ depressive symptoms (as indexed by both self- and mother-report of girlsâ symptoms), whereas boysâ symptoms were positively related to GMV. Our findings suggest that brain morphology in the OFC, a region with functional roles in processes relevant to depressive symptoms (i.e., reward-based learning and reward processing), is associated with early depressive symptoms prior to the development of clinically significant depression
Maternal Depression, Child Temperament, and Early-Life Stress Predict Never-Depressed Preadolescentsâ Functional Connectivity During a Negative-Mood Induction
Understanding the development of depression can inform etiology and prevention/intervention. Maternal depression and maladaptive patterns of temperament (e.g., low positive emotionality [PE] or high negative emotionality, especially sadness) are known to predict depression. Although it is unclear how these risks cause depression, altered functional connectivity (FC) during negative-emotion processing may play an important role. We investigated whether maternal depression and age-3 emotionality predicted FC during negative mood reactivity in never-depressed preadolescents and whether these relationships were augmented by early-life stress. Maternal depression predicted decreased medial prefrontal cortex (mPFC)âamygdala and mPFCâinsula FC but increased mPFCâposterior cingulate cortex (PCC) FC. PE predicted increased dorsolateral prefrontal cortexâamygdala FC, whereas sadness predicted increased PCC-based FC in insula, orbitofrontal cortex, and anterior cingulate cortex (ACC). Sadness was more strongly associated with PCCâinsula and PCCâACC FC as early stress increased. Findings indicate that early depression risks may be mediated by FC underlying negative-emotion processing
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
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