The fishing industry of colonial Massachusetts, 1620-1660

Thesis (M.A.)--Boston Universit

Child maltreatment and autonomic nervous system reactivity: identifying dysregulated stress reactivity patterns by using the biopsychosocial model of challenge and threat.

ObjectiveDisruptions in stress response system development have been posited as mechanisms linking child maltreatment (CM) to psychopathology. Existing theories predict elevated sympathetic nervous system reactivity after CM, but evidence for this is inconsistent. We present a novel framework for conceptualizing stress reactivity after CM that uses the biopsychosocial model of challenge and threat. We predicted that in the context of a social-evaluative stressor, maltreated adolescents would exhibit a threat pattern of reactivity, involving sympathetic nervous system activation paired with elevated vascular resistance and blunted cardiac output (CO) reactivity.MethodsA sample of 168 adolescents (mean age =14.9 years) participated. Recruitment targeted maltreated adolescents; 38.2% were maltreated. Electrocardiogram, impedance cardiography, and blood pressure were acquired at rest and during an evaluated social stressor (Trier Social Stress Test). Pre-ejection period (PEP), CO, and total peripheral resistance reactivity were computed during task preparation, speech delivery, and verbal mental arithmetic. Internalizing and externalizing symptoms were assessed.ResultsMaltreatment was unrelated to PEP reactivity during preparation or speech, but maltreated adolescents had reduced PEP reactivity during math. Maltreatment exposure (F(1,145) = 3.8-9.4, p = .053-<.001) and severity (β = -0.10-0.12, p = .030-.007) were associated with significantly reduced CO reactivity during all components of the stress task and marginally associated with elevated total peripheral resistance reactivity (F(1,145) = 3.8-9.4; p = .053-<.001 [β = 0.07-0.11] and p = .11-.009, respectively). Threat reactivity was positively associated with externalizing symptoms.ConclusionsCM is associated with a dysregulated pattern of physiological reactivity consistent with theoretical conceptualizations of threat but not previously examined in relation to maltreatment, suggesting a more nuanced pattern of stress reactivity than predicted by current theoretical models

Thinking beyond the tumor cell: Nf1 haploinsufficiency in the tumor environment

AbstractDeletion of both copies of the Nf1 gene in Schwann cells combined with Nf1 heterozygosity in the tumor environment promotes neurofibroma formation in mice

Beyond Cumulative Risk: A Dimensional Approach to Childhood Adversity

Children who have experienced environmental adversity—such as abuse, neglect, or poverty—are more likely to develop physical and mental health problems, perform poorly at school, and have difficulties in social relationships than children who have not encountered adversity. What is less clear is how and why adverse early experiences exert such a profound influence on children’s development. Identifying developmental processes that are disrupted by adverse early environments is the key to developing better intervention strategies for children who have experienced adversity. Yet, much existing research relies on a cumulative risk approach that is unlikely to reveal these mechanisms. This approach tallies the number of distinct adversities experienced to create a risk score. This risk score fails to distinguish between distinct types of environmental experience, implicitly assuming that very different experiences influence development through the same underlying mechanisms. We advance an alternative model. This novel approach conceptualizes adversity along distinct dimensions, emphasizes the central role of learning mechanisms, and distinguishes between different forms of adversity that might influence learning in distinct ways. A key advantage of this approach is that learning mechanisms provide clear targets for interventions aimed at preventing negative developmental outcomes in children who have experienced adversity

A Model to Evaluate Efficiency in Operating Room Processes.

In the operating room, efficiency is related to minutes pared from surgical time. The link between operating room efficiency and the composition of surgical teams has been investigated, yet research on the efficiency of surgical nursing staff members and operating room durations is scant. The purpose of this study was to assess the effects of nursing staff arrangements in surgery, with a view to better planning of staff training and structure to achieve savings in time and money. A conceptual framework based on scientific management theory was used to evaluate efficiency in operating room processes as time within and between surgical cases, and projected that nursing staff arrangements including specialization, standardization, and skill mix in surgical processes were key factors in reducing operating room process time. This retrospective, cross-sectional study examined data from electronic records of general surgery cases conducted in 2008 in a large U.S. teaching hospital. The research questions addressed the amount of variation in operating room process efficiency explained by nursing staff arrangement variables after controlling for environmental, patient health status, and case complexity variables. The explanatory statistical model included four independent variables to reflect operating room nursing staff patterns; four control variables to represent environmental conditions, patient health status, and case complexity; and five dependent variables for separate timeframes. Hierarchical regression analysis confirmed that the degree of nursing staff specialization in general surgery explained a significant portion of the variation in process timeframes spanning the surgical procedure, the duration between surgical cases, and the entirety of time within and between cases. Findings that scientific management principles may represent nursing staff arrangements indicate a need for further research to understand the factors that affect the use of perioperative time. One research avenue is to explore the cost-effectiveness of organizing the operating room nursing staff into specialty service teams; another is to evaluate turnover time as an opportunity cost from the perspective of patients, staff, and payers. Use of this model will improve both day-to-day and longer-term planning to optimize use of resources, in particular, nursing labor inputs, that contribute to an efficient and harmonious health care economy.PHDNursingUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/96155/1/mmmcl_1.pd