The Application of Bystander Intervention Scripts: Implications for Guardianship in Action

Responding to high rates of interpersonal victimization and perpetration among adolescents, schools have implemented bystander intervention (BI) training to educate students to intervene to prevent or stop violence. These trainings function much like an application of scripts for guardianship in action. The current study builds on the overlapping and complementary bodies of BI and routine activities research by testing whether participation in BI training, namely Green Dot (GD), influences individuals’ underlying ability to intervene. Using four years of survey data collected from high school students (N = 2,374–3,443), we use item response theory to model the difficulty of engaging in different BI behaviors. We then estimate multivariate ordinary least squares regression models, one for each year, to estimate the effect of GD training on students’ ability to intervene. The item response theory results show that BI behaviors differ in terms of how “difficult” they are for respondents to engage in. Findings show that in each year, GD training increased students’ underlying ability to intervene. Our findings suggest BI training and guardianship in action scripts should take into account this varying difficulty of intervention behaviors to best train individuals for successful intervention to prevent victimization

Deficiency of Complement Component C1Q Prevents Cerebrovascular Damage and White Matter Loss in a Mouse Model of Chronic Obesity.

Age-related cognitive decline and many dementias involve complex interactions of both genetic and environmental risk factors. Recent evidence has demonstrated a strong association of obesity with the development of dementia. Furthermore, white matter damage is found in obese subjects and mouse models of obesity. Here, we found that components of the complement cascade, including complement component 1qa (C1QA) and C3 are increased in the brain of Western diet (WD)-fed obese mice, particularly in white matter regions. To functionally test the role of the complement cascade in obesity-induced brain pathology, female and male mice deficient in C1QA, an essential molecule in the activation of the classical pathway of the complement cascade, were fed a WD and compared with WD-fed wild type (WT) mice, and t

Transcriptional profiling predicts running promotes cerebrovascular remodeling in young but not midlife mice.

BACKGROUND: The incidence of dementia and cognitive decline is increasing with no therapy or cure. One of the reasons treatment remains elusive is because there are various pathologies that contribute to age-related cognitive decline. Specifically, with Alzheimer\u27s disease, targeting to reduce amyloid beta plaques and phosphorylated tau aggregates in clinical trials has not yielded results to slow symptomology, suggesting a new approach is needed. Interestingly, exercise has been proposed as a potential therapeutic intervention to improve brain health and reduce the risk for dementia, however the benefits throughout aging are not well understood. RESULTS: To better understand the effects of exercise, we preformed transcriptional profiling on young (1-2 months) and midlife (12 months) C57BL/6 J (B6) male mice after 12 weeks of voluntary running. Data was compared to age-matched sedentary controls. Interestingly, the midlife running group naturally broke into two cohorts based on distance ran - either running a lot and more intensely (high runners) or running less and less intensely (low runners). Midlife high runners had lower LDL cholesterol as well as lower adiposity (%fat) compared to sedentary, than midlife low runners compared to sedentary suggesting more intense running lowered systemic markers of risk for age-related diseases including dementias. Differential gene analysis of transcriptional profiles generated from the cortex and hippocampus showed thousands of differentially expressed (DE) genes when comparing young runners to sedentary controls. However, only a few hundred genes were DE comparing either midlife high runners or midlife low runners to midlife sedentary controls. This indicates that, in our study, the effects of running are reduced through aging. Gene set enrichment analyses identified enrichment of genes involved in extracellular matrix (ECM), vascular remodeling and angiogenesis in young runners but not midlife runners. These genes are known to be expressed in multiple vascular-related cell types including astrocytes, endothelial cells, pericytes and smooth muscle cells. CONCLUSIONS: Taken together these results suggest running may best serve as a preventative measure to reduce risk for cerebrovascular decline. Ultimately, this work shows that exercise may be more effective to prevent dementia if introduced at younger ages

Examining the Effect of Perceived Responsibility on Online Bystander Intervention, Target Hardening, and Inaction

Failure to take responsibility for intervening has been identified as a primary barrier to bystander intervention. Building on these findings, we examine how perceptions of responsibility affect responses to witnessing victimization in the online realm—a topic that has received limited attention. Using a maximum-likelihood selection model, we analyze data from the Pew American Trends Panel (N = 3709) to estimate the effects of respondents’ perceptions of the role different groups should play in addressing online harassment on their likelihood to engage in intervention, target hardening, or inaction in response to witnessing online harassment, conditioned upon their likelihood of having witnessed such behavior. Findings indicate that the greater role respondents believe online users should have in addressing online harassment, the more likely they are to intervene. (b = .310). The greater role respondents believe law enforcement or elected officials should have in addressing online harassment, the less likely they are to intervene (b = −.135 and −.072, respectively). These findings have implications for future efforts to curb online harassment through users’ crime prevention efforts

Examining the Effect of Perceived Responsibility On Online Bystander Intervention, Target Hardening, and Inaction

Failure to take responsibility for intervening has been identified as a primary barrier to bystander intervention. Building on these findings, we examine how perceptions of responsibility affect responses to witnessing victimization in the online realm—a topic that has received limited attention. Using a maximum-likelihood selection model, we analyze data from the Pew American Trends Panel (N = 3709) to estimate the effects of respondents’ perceptions of the role different groups should play in addressing online harassment on their likelihood to engage in intervention, target hardening, or inaction in response to witnessing online harassment, conditioned upon their likelihood of having witnessed such behavior. Findings indicate that the greater role respondents believe online users should have in addressing online harassment, the more likely they are to intervene. (b = .310). The greater role respondents believe law enforcement or elected officials should have in addressing online harassment, the less likely they are to intervene (b = −.135 and −.072, respectively). These findings have implications for future efforts to curb online harassment through users’ crime prevention efforts

Genetic perturbations of disease risk genes in mice capture transcriptomic signatures of late-onset Alzheimer\u27s disease.

BACKGROUND: New genetic and genomic resources have identified multiple genetic risk factors for late-onset Alzheimer\u27s disease (LOAD) and characterized this common dementia at the molecular level. Experimental studies in model organisms can validate these associations and elucidate the links between specific genetic factors and transcriptomic signatures. Animal models based on LOAD-associated genes can potentially connect common genetic variation with LOAD transcriptomes, thereby providing novel insights into basic biological mechanisms underlying the disease. METHODS: We performed RNA-Seq on whole brain samples from a panel of six-month-old female mice, each carrying one of the following mutations: homozygous deletions of Apoe and Clu; hemizygous deletions of Bin1 and Cd2ap; and a transgenic APOEε4. Similar data from a transgenic APP/PS1 model was included for comparison to early-onset variant effects. Weighted gene co-expression network analysis (WGCNA) was used to identify modules of correlated genes and each module was tested for differential expression by strain. We then compared mouse modules with human postmortem brain modules from the Accelerating Medicine\u27s Partnership for AD (AMP-AD) to determine the LOAD-related processes affected by each genetic risk factor. RESULTS: Mouse modules were significantly enriched in multiple AD-related processes, including immune response, inflammation, lipid processing, endocytosis, and synaptic cell function. WGCNA modules were significantly associated with Apoe CONCLUSIONS: This study of genetic mouse models provides a basis to dissect the role of AD risk genes in relevant AD pathologies. We determined that different genetic perturbations affect different molecular mechanisms comprising AD, and mapped specific effects to each risk gene. Our approach provides a platform for further exploration into the causes and progression of AD by assessing animal models at different ages and/or with different combinations of LOAD risk variants

Transcriptome profiling of brain myeloid cells revealed activation of Itgal, Trem1, and Spp1 in western diet-induced obesity.

BACKGROUND: Environmental factors are critical in the development of age-related cognitive decline and dementia. A western diet (WD) can cause nutrient deficiency and inflammation that could impact cognition directly. It is increasingly recognized that innate immune responses by brain myeloid cells, such as resident microglia, and infiltrating peripheral monocytes/macrophages may represent an essential link between a WD, cognitive decline, and dementia. Our previous data demonstrated that chronic consumption of a WD induced inflammation through brain myeloid cells in aging mice and a mouse model of Alzheimer\u27s disease (AD). However, the subtypes of myeloid cells that contribute to the WD-induced inflammation remain unclear. METHODS: C57BL/6J (B6), myeloid cell reporter mice (B6.Ccr2 RESULTS: Ccr2::RFP expressing myeloid cells were significantly increased in brains of WD- compared to CD-fed mice, but were not elevated in Ccr2-deficient WD-fed mice. The percent of CD11b+CD45 CONCLUSIONS: These data further support the model that peripheral myeloid cells enter the brain in response to diet-induced obesity. Elucidating their contribution to age-related cognitive decline and age-related neurodegenerative diseases should offer new avenues for therapeutic intervention in Alzheimer\u27s disease and related dementias, where diet/obesity are major risk factors

Who Wears the MAGA Hat? Racial Beliefs and Faith in Trump

On the basis of a 2019 YouGov survey of white respondents (n = 734), the impact of racial beliefs on support for Donald Trump was explored. The analysis revealed that in addition to racial resentment, white nationalism—a desire to keep the United States white demographically and culturally—was strongly related to faith in Trump. Analyses based on a 2019 Amazon Mechanical Turk survey yielded similar results and also showed that white nationalism increased willingness to wear a MAGA hat. Future research on the political consequences of racial beliefs should focus on what whites think not only of blacks but also of themselves

Meox2 haploinsufficiency increases neuronal cell loss in a mouse model of Alzheimer\u27s disease

Evidence suggests that multiple genetic and environmental factors conspire together to increase susceptibility to Alzheimer\u27s disease (AD). The amyloid cascade hypothesis states that deposition of the amyloid-β (Aβ) peptide is central to AD; however, evidence in humans and animals suggests that Aβ buildup alone is not sufficient to cause neuronal cell loss and cognitive decline. Mouse models that express high levels of mutant forms of amyloid precursor protein and/or cleaving enzymes deposit amyloid but do not show neuron loss. Therefore, a double-hit hypothesis for AD has been proposed whereby vascular dysfunction precedes and promotes Aβ toxicity. In support of this, copy number variations in mesenchyme homeobox 2 (MEOX2), a gene involved in vascular development, are associated with severe forms of AD. However, the role of MEOX2 in AD has not been studied. Here, we tested Meox2 haploinsufficiency in B6.APP/PS1 (B6.APBTg) mice, a mouse model of AD. Despite no overt differences in plaque deposition or glial activation, B6.APBTg mice that carry only one copy of Meox2 (B6.APBTg.Mx−/+) show increased neuronal cell loss, particularly in regions containing plaques, compared with B6.APBTgmice. Neuronal cell loss corresponds with a significant decrease in plaque-associated microvessels, further supporting a synergistic effect of vascular compromise and amyloid deposition on neuronal cell dysfunction in AD

Meox2 haploinsufficiency increases neuronal cell loss in a mouse model of Alzheimer\u27s disease

Evidence suggests that multiple genetic and environmental factors conspire together to increase susceptibility to Alzheimer\u27s disease (AD). The amyloid cascade hypothesis states that deposition of the amyloid-β (Aβ) peptide is central to AD; however, evidence in humans and animals suggests that Aβ buildup alone is not sufficient to cause neuronal cell loss and cognitive decline. Mouse models that express high levels of mutant forms of amyloid precursor protein and/or cleaving enzymes deposit amyloid but do not show neuron loss. Therefore, a double-hit hypothesis for AD has been proposed whereby vascular dysfunction precedes and promotes Aβ toxicity. In support of this, copy number variations in mesenchyme homeobox 2 (MEOX2), a gene involved in vascular development, are associated with severe forms of AD. However, the role of MEOX2 in AD has not been studied. Here, we tested Meox2 haploinsufficiency in B6.APP/PS1 (B6.APBTg) mice, a mouse model of AD. Despite no overt differences in plaque deposition or glial activation, B6.APBTg mice that carry only one copy of Meox2 (B6.APBTg.Mx−/+) show increased neuronal cell loss, particularly in regions containing plaques, compared with B6.APBTgmice. Neuronal cell loss corresponds with a significant decrease in plaque-associated microvessels, further supporting a synergistic effect of vascular compromise and amyloid deposition on neuronal cell dysfunction in AD