Physiological Stress Responses to a Live-Fire Training Evolution in Career Firefighters

Firefighters have a physically demanding job that exposes them to many specific and unique stressors, which contribute to cardiovascular disease (CVD) risk (i.e., cardiovascular strain, inflammation, and oxidative stress) or even mortality. At present, the literature lacks data evaluating these physiological stress responses amongst firefighters in any realistic or simulated scenarios, such as a live-fire training evolution (LFTE). Given the elevated risk of premature mortality, there is a critical need to better understand the physiological stress responses to an LFTE. This information could aid in developing nutritional, training, and other various interventions to mitigate stress load and reduce the incidence of CVD among this population. PURPOSE: To assess the physiological stress response to an LFTE among firefighters. METHODS: Seventy-six (n = 76) career firefighters completed an LFTE. Salivary samples were collected pre, immediately post, and 30-min post the LFTE, and analyzed the following stress markers: α-amylase (AA), secretory immunoglobulin-A (SIgA), and cortisol. One-way repeated measures analysis of variance was used to assess changes over time. Fisher’s LSD and Cohen’s d effect size calculations were used for Post hoc analysis. RESULTS: Significant main effects for time were found for AA, SIgA, and cortisol (p\u3c0.001). Fisher’s LSD post hoc analysis found AA, SIgA, and cortisol concentrations were all significantly elevated immediately post LFTE compared to pre (p\u3c0.0001) and 30-min post (p\u3c0.0001). Medium to large effect sizes were noted for AA, SIgA, and cortisol with respect to changes pre to immediately post-LFTE (d = 0.84, 0.61, and 0.78, respectively). CONCLUSION: While many studies have shown increased inflammation and oxidative stress, as well as adverse cardiovascular and metabolic responses to firefighting activities, these data provide insight into the physiological stress placed upon a firefighter engaging in fire-suppressive evolutions

Identification of Orch3, a Locus Controlling Dominant Resistance to Autoimmune Orchitis, as Kinesin Family Member 1C

Experimental autoimmune orchitis (EAO), the principal model of non-infectious testicular inflammatory disease, can be induced in susceptible mouse strains by immunization with autologous testicular homogenate and appropriate adjuvants. As previously established, the genome of DBA/2J mice encodes genes that are capable of conferring dominant resistance to EAO, while the genome of BALB/cByJ mice does not and they are therefore susceptible to EAO. In a genome scan, we previously identified Orch3 as the major quantitative trait locus controlling dominant resistance to EAO and mapped it to chromosome 11. Here, by utilizing a forward genetic approach, we identified kinesin family member 1C (Kif1c) as a positional candidate for Orch3 and, using a transgenic approach, demonstrated that Kif1c is Orch3. Mechanistically, we showed that the resistant Kif1c$^{D2}$ allele leads to a reduced antigen-specific T cell proliferative response as a consequence of decreased MHC class II expression by antigen presenting cells, and that the L$^{578}$→P$^{578}$ and S$^{1027}$→P$^{1027}$ polymorphisms distinguishing the BALB/cByJ and DBA/2J alleles, respectively, can play a role in transcriptional regulation. These findings may provide mechanistic insight into how polymorphism in other kinesins such as KIF21B and KIF5A influence susceptibility and resistance to human autoimmune diseases

Book Reviews

Book reviews of: Hattiesburg: An American City in Black and White By William Sturkey. (Cambridge: Harvard University Press, 2019. Acknowledgements, illustrations, map, notes, index. Pp. 442. $29.95 cloth. ISBN 978-0-674-97635-1.) Confederate Generals in the Trans-Mississippi, Volume 3: Essays on America’s Civil War. Edited by Thomas E. Schott and Lawrence Lee Hewitt. (Knoxville: University of Tennessee Press, 2019. Maps, photos, notes, appendix, bibliography, index. Pp. xxiv, 374.$64.95 cloth. ISBN: 978-1-62190-454-0.) Mothers of Massive Resistance: White Women and the Politics of White Supremacy. By Elizabeth Gillespie McRae. (New York: Oxford University Press, 2018. Acknowledgements, Abbreviations, illustrations, notes, index. Pp. xiv, 343. $34.95 hardcover. ISBN: 978-0-19-027171-8.) Poll Power: The Voter Education Project and the Movement for the Ballot in the American South. By Evan Faulkenbury. (Chapel Hill: University of North Carolina Press, 2019. Acknowledgements, illustrations, notes, index. Pp. xi, 200.$90 cloth, $27.95 paper. ISBN: 978-1-4696-5131-6.) Let Us Make Men: The Twentieth Century Black Press and a Manly Vision for Racial Advancement. By D’Weston Haywood. (Chapel Hill: University of North Carolina Press, 2018. Acknowledgements, illustrations, map, notes, index. Pp. xi, 340.$55 cloth, $19.50 paper. ISBN: 978-1-4696-4338-0.) The Man Who Punched Jefferson Davis: The Political Life of Henry S. Foote, Southern Unionist. By Ben Wynne. (Baton Rouge, Louisiana State University Press, 2018. Acknowledgements, illustrations, notes, index. Pp. ix, 323.$47.50 cloth. ISBN: 978-0-8071-6933-9.) Desegregating Dixie: The Catholic Church in the South and Desegregation, 1945-1992. By Mark Newman. (Jackson: University Press of Mississippi, 2018. Acknowledgements, appendices, notes, bibliography, index. Pp. xvii, 455. $90 cloth,$30 paper. ISBN: 978-1-4968-1886-7.) The Loyal Republic: Traitors, Slaves, and the Remaking of Citizenship in Civil War America. By Erik Mathisen. (Chapel Hill: The University of North Carolina Press, 2018. Acknowledgments, illustrations, map, notes, index. Pp. xi, 219. $34.95 cloth. ISBN: 978-1-4696-3632-0.) Aberration of Mind: Suicide and Suffering in the Civil War-Era South. By Diane Miller Sommerville. (Chapel Hill: University of North Carolina Press, 2018. Acknowledgements, notes, bibliography, index. Pp. 448.$105 cloth, $34.95 paper. ISBN: 978-1-4696-4330-4.) Women’s War: Fighting and Surviving the American Civil War. By Stephanie McCurry. (Cambridge, Massachusetts: The Belknap Press of Harvard University Press, 2019. notes, acknowledgements, index. Pp ix, 297.$26.95 hardcover. ISBN: 978-0-674-98797-5.) Lines Were Drawn: Remembering Court-Ordered Integration at a Mississippi High School. Edited By Teena F. Horn, Alan Huffman, and John G. Jones. (Jackson: University Press of Mississippi, 2016. Acknowledgments, illustrations, map, notes, index. Pp. xi, 266. $35 hard back. ISBN: 978-1-62846-231-9.) Industrial Development and Manufacturing in the Antebellum Gulf South: A Reevaluation. By Michael S. Frawley. (Baton Rouge: Louisiana State University Press. 2019. ix, 256 pp. Cloth,$45.00, ISBN 978-0-8071-7068-7.) Integration Now: Alexander v. Holmes and the End of Jim Crow Education. By William P. Hustwit. (Chapel Hill: University of North Carolina Press, 2019. 8 halftones, 1 map, notes, bibl., index. 288 pp. $39.95, hardcover. ISBN: 978-1-4696-4855-2.

Snapshots of Simulation: Innovative Strategies Used by International Educators to Enhance Simulation Learning Experiences for Health Care Students

Innovations in simulation in nursing and health care continue to be developed as creative and committed educators respond to challenges of providing pedagogically sound, engaging and effective learning experiences for large student cohorts. Time-pressed educators may find it difficult to network with others working in simulation-based learning, and thus, it is useful to provide summaries or snapshots to provide a brief overview of activities in various countries using simulation in a variety of ways. The purpose of this paper is to profile a diverse range of innovative, cost-effective, and tested simulation approaches that have been implemented in healthcare programs by nursing educators from a range of countries to spark creativity. Each strategy was designed to address contemporary and critical practice issues. They facilitate immersion in authentic clinical scenarios, increase students’ awareness of cues in the environent that may compromise health and safety, and prepare students for cultural or clinical realities that they may not routinely encounter because of the inherent restrictions associated with clinical placements

Specifying and Validating Probabilistic Inputs for Prescriptive Models of Decision Making over Time

Optimization models for making decisions over time in uncertain environments rely on probabilistic inputs, such as scenario trees for stochastic mathematical programs. The quality of model outputs, i.e., the solutions obtained, depends on the quality of these inputs. However, solution quality is rarely assessed in a rigorous way. The connection between validation of model inputs and quality of the resulting solution is not immediate. This chapter discusses some efforts to formulate realistic probabilistic inputs and subsequently validate them in terms of the quality of solutions they produce. These include formulating probabilistic models based on statistical descriptions understandable to decision makers; conducting statistical tests to assess the validity of stochastic process models and their discretization; and conducting re-enactments to assess the quality of the formulation in terms of solution performance against observational data. Studies of long-term capacity expansion in service industries, including electric power, and short-term scheduling of thermal electricity generating units provide motivation and illustrations. The chapter concludes with directions for future research

Skeletal Adaptation to Intramedullary Pressure-Induced Interstitial Fluid Flow Is Enhanced in Mice Subjected to Targeted Osteocyte Ablation

Interstitial fluid flow (IFF) is a potent regulatory signal in bone. During mechanical loading, IFF is generated through two distinct mechanisms that result in spatially distinct flow profiles: poroelastic interactions within the lacunar-canalicular system, and intramedullary pressurization. While the former generates IFF primarily within the lacunar-canalicular network, the latter generates significant flow at the endosteal surface as well as within the tissue. This gives rise to the intriguing possibility that loading-induced IFF may differentially activate osteocytes or surface-residing cells depending on the generating mechanism, and that sensation of IFF generated via intramedullary pressurization may be mediated by a non-osteocytic bone cell population. To begin to explore this possibility, we used the Dmp1-HBEGF inducible osteocyte ablation mouse model and a microfluidic system for modulating intramedullary pressure (ImP) to assess whether structural adaptation to ImP-driven IFF is altered by partial osteocyte depletion. Canalicular convective velocities during pressurization were estimated through the use of fluorescence recovery after photobleaching and computational modeling. Following osteocyte ablation, transgenic mice exhibited severe losses in bone structure and altered responses to hindlimb suspension in a compartment-specific manner. In pressure-loaded limbs, transgenic mice displayed similar or significantly enhanced structural adaptation to Imp-driven IFF, particularly in the trabecular compartment, despite up to ∼50% of trabecular lacunae being uninhabited following ablation. Interestingly, regression analysis revealed relative gains in bone structure in pressure-loaded limbs were correlated with reductions in bone structure in unpressurized control limbs, suggesting that adaptation to ImP-driven IFF was potentiated by increases in osteoclastic activity and/or reductions in osteoblastic activity incurred independently of pressure loading. Collectively, these studies indicate that structural adaptation to ImP-driven IFF can proceed unimpeded following a significant depletion in osteocytes, consistent with the potential existence of a non-osteocytic bone cell population that senses ImP-driven IFF independently and potentially parallel to osteocytic sensation of poroelasticity-derived IFF

Dynamic Gene Expression in the Human Cerebral Cortex Distinguishes Children from Adults

In comparison with other primate species, humans have an extended juvenile period during which the brain is more plastic. In the current study we sought to examine gene expression in the cerebral cortex during development in the context of this adaptive plasticity. We introduce an approach designed to discriminate genes with variable as opposed to uniform patterns of gene expression and found that greater inter-individual variance is observed among children than among adults. For the 337 transcripts that show this pattern, we found a significant overrepresentation of genes annotated to the immune system process (pFDR≅0). Moreover, genes known to be important in neuronal function, such as brain-derived neurotrophic factor (BDNF), are included among the genes more variably expressed in childhood. We propose that the developmental period of heightened childhood neuronal plasticity is characterized by more dynamic patterns of gene expression in the cerebral cortex compared to adulthood when the brain is less plastic. That an overabundance of these genes are annotated to the immune system suggests that the functions of these genes can be thought of not only in the context of antigen processing and presentation, but also in the context of nervous system development

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements