Opening Session

Chancellor Motley Jessica Cicchino – Insurance Institute for Highway Safety, National crash trends Jeanne Hathaway – MA DPH Injury Prevention Epidemiologist, MA context Beth Dugan – UMass Boston, Fatal Accidents in MA involving drivers age 65+; Summit aim

Explicit incorporation of spatial variability in a biomass dynamics assessment model

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Incorporating intra-annual variability in fisheries abundance data to better capture population dynamics

To reduce the risk of overexploitation and the ensuing conservation and socio-economic consequences, fisheries management relies on receiving accurate scientific advice from stock assessments. Biomass dynamics models used in stock assessment tend to rely primarily on indices of abundance and commercial landings data. Standard practice for calculating the indices used in these models typically involves taking averages of survey tow data over large, diverse spatial domains. There is a lot of variability in the choice of methodologies used to propagate index uncertainty into the assessment model, many of which require specifying it through expert knowledge or prior distributions. Here we propose an alternative approach that treats each individual survey tow as an independent estimate of the true underlying biomass in the stock assessment model itself. This reduces information loss and propagates uncertainties into the model directly. A simulation study demonstrates that this approach accurately captures underlying population dynamics and reliably estimates variance parameters. We further demonstrate its utility with data from the Inshore Scallop Fishery of south-west Nova Scotia. Results show significant improvements in parameter estimation over previous models while providing similar predictions of biomass with less uncertainty. This reduced uncertainty can improve the resulting scientific advice and lead to improved decision-making by fisheries managers.publishedVersio

Epidemiology of community-acquired meticillin-resistant Staphylococcus aureus obtained from the UK West Midlands region

Between January 2005 and December 2005, 199 meticillin-resistant Staphylococcus aureus (MRSA) isolates were obtained from nonhospitalised patients presenting skin and soft tissue infections to local general practitioners. The study area incorporated 57 surgeries from three Primary Care Trusts in the Lichfield, Tamworth, Burntwood, North and East Birmingham regions of Central England, UK. Following antibiotic susceptibility testing, pulsed-field gel electrophoresis, Panton-Valentine leukocidin gene detection and SCCmec element assignment, 95% of the isolates were shown to be related to hospital epidemic strains EMRSA-15 and EMRSA-16. In total 87% of the isolate population harboured SCCmec IV, 9% had SCCmec II and 4% were identified as carrying novel SCCmec IIIa-mecI. When mapped to patient home postcode, a diverse distribution of isolates harbouring SCCmec II and SCCmec IV was observed; however, the majority of isolates harbouring SCCmec IIIa-mecI were from patients residing in the north-west of the study region, highlighting a possible localised clonal group. Transmission of MRSA from the hospital setting into the surrounding community population, as demonstrated by this study, warrants the need for targeted patient screening and decolonisation in both the clinical and community environments

Nexus of Despair: A Network Analysis of Suicidal Ideation among Veterans

The objective of this study was to estimate a network model of risk and resilience factors of suicidal ideation among veterans. Two network models of suicidal ideation among Operation Iraqi Freedom/ Operation Enduring Freedom/Operation New Dawn veterans (N = 276) incorporated key disorders, traumatic stress, and resilience constructs to contextualize suicidal ideation. Childhood trauma was positively connected with suicidal ideation and harassment and inversely connected with social support and distress tolerance. This exemplifies long-lasting associations between childhood trauma and revictimization, emotion regulation, and ability to form supportive social relationships. A subsequent model including lower-order facets indicated that combat trauma was predominantly associated with posttraumatic stress disorder–intrusion symptoms. This study highlights the importance of addressing both risk and resilience to reduce suicide risk among veterans and increases understanding of factors that contribute to suicidal ideation

PTSD Symptoms and Alcohol-Related Problems among Veterans: Temporal Associations and Vulnerability

Posttraumatic stress disorder (PTSD) is associated with elevated risk of both alcohol use disorder (AUD) and related conduct problems, which are associated with behavioral and emotional dysregulation. We conducted an intensive longitudinal burst design study with 10 weeks of experience sampling over the course of 1.5 years with 250 veterans of recent conflicts. We tested time-series models of daily associations between posttraumatic stress symptoms (PTSS), alcohol dependence syndrome, and conduct problems. Exacerbations of PTSS predicted higher dependence syndrome and conduct problems the next day. This effect was significant after controlling for both concurrent (i.e., same-day) associations between drinking and the outcomes as well as the strength of associations between the outcomes from one day to the next (i.e., autoregression). Affect lability and disinhibition were hypothesized vulnerability factors increasing the strength of within-person predictors of dependence syndrome and conduct problems. Lability and disinhibition were associated with greater dependence syndrome symptoms and conduct problems over the follow-up period. Consistent with expectation, lability rather than disinhibition increased the association between drinking and dependence syndrome as well as the strength of association between dependence syndrome symptoms from one day to the next. Moderating effects of disinhibition in the conduct problems model were not significant. Importantly, results indicated reciprocal associations over time. Lability potentiated the association between dependence syndrome symptoms and next-day PTSS, whereas disinhibition potentiated the association between conduct problems and next-day PTSS. Results demonstrate complex dynamic associations between PTSS, AUD symptoms, and conduct problems over time indicative of broad regulatory impairments

Spatial aspects of MRSA epidemiology:A case study using stochastic simulation, kernel estimation and SaTScan

The identification of disease clusters in space or space-time is of vital importance for public health policy and action. In the case of methicillin-resistant Staphylococcus aureus (MRSA), it is particularly important to distinguish between community and health care-associated infections, and to identify reservoirs of infection. 832 cases of MRSA in the West Midlands (UK) were tested for clustering and evidence of community transmission, after being geo-located to the centroids of UK unit postcodes (postal areas roughly equivalent to Zip+4 zip code areas). An age-stratified analysis was also carried out at the coarser spatial resolution of UK Census Output Areas. Stochastic simulation and kernel density estimation were combined to identify significant local clusters of MRSA (p<0.025), which were supported by SaTScan spatial and spatio-temporal scan. In order to investigate local sampling effort, a spatial 'random labelling' approach was used, with MRSA as cases and MSSA (methicillin-sensitive S. aureus) as controls. Heavy sampling in general was a response to MRSA outbreaks, which in turn appeared to be associated with medical care environments. The significance of clusters identified by kernel estimation was independently supported by information on the locations and client groups of nursing homes, and by preliminary molecular typing of isolates. In the absence of occupational/ lifestyle data on patients, the assumption was made that an individual's location and consequent risk is adequately represented by their residential postcode. The problems of this assumption are discussed, with recommendations for future data collection

Relationship Between Changes in Upper Body Fat-Free Mass and Bench Press Performance in American Football Players

Horizontal pushing strength and strength endurance are relevant attributes for blocking and block shedding in American football. Since most positions in American football require the ability to either block or shed a block, and since bench press repetitions to failure (RTF) with 225 pounds is a component of the NFL draft combine, improving horizontal pushing strength and strength endurance have been key areas of emphasis for strength and conditioning coaches working with these athletes. PURPOSE: The purpose of this analysis was to quantify the relationship between changes in upper body fat-free mass (FFM) and metrics of bench press performance in American football players. METHODS: Body composition and muscular performance were assessed in NCAA Division III American football players. Upper body FFM was obtained from dual-energy X-ray absorptiometry (DXA; Hologic Horizon) before and after a seven-week offseason training period. Barbell bench press one-repetition maximum (1RM), incline barbell bench press 1RM, and RTF with 225 pounds on the barbell bench press were also determined before and after the training period. Using Spearman’s rank correlations, the relationships between percent changes in upper body FFM and bench press 1RM (n=19), bench press RTF with 225 pounds (n=15), and incline bench press 1RM (n=18) were evaluated. RESULTS: Relative changes in bench press 1RM and DXA upper body FFM exhibited a weak, non-significant correlation (ρ: 0.38, p: 0.11). However, there was a moderate strength, significant correlation between relative changes in bench press RTF with 225 pounds and DXA upper body FFM (ρ: 0.53, p: 0.04). For relative changes in incline bench press 1RM, there was a weak, non-significant correlation with DXA upper body FFM (ρ: 0.24, p: 0.36). CONCLUSION: Of the performance tests assessed, only changes in bench press RTF with 225 pounds and changes in DXA upper body FFM were positively correlated. Therefore, strength and conditioning coaches working with athletes who plan on entering the NFL draft may want to consider dedicating time to increasing upper body FFM gains prior to the draft as it appears to be positively correlated with performance on this NFL combine test