A protocol for distilling animal body water from biological samples and measuring oxygen and hydrogen stable isotopes via cavity ring-down spectroscopy.

The application of stable isotope analysis (SIA) to the fields of ecology and animal biology has rapidly expanded over the past three decades, particularly with regards to water analysis. SIA now provides the opportunity to monitor migration patterns, examine food webs, and assess habitat changes in current and past study systems. While carbon and nitrogen SIA of biological samples have become common, analyses of oxygen or hydrogen are used more sparingly despite their promising utility for tracing water sources and animal metabolism. Common ecological applications of oxygen or hydrogen SIA require injecting enriched isotope tracers. As such, methods for processing and analyzing biological samples are tailored for enriched tracer techniques, which require lower precision than other techniques given the large signal-to-noise ratio of the data. However, instrumentation advancements are creating new opportunities to expand the applications of high-throughput oxygen and hydrogen SIA. To support these applications, we update methods to distill and measure water derived from biological samples with consistent precision equal to, or better than, ± 0.1 ‰ for δ17O, ± 0.3 ‰ for δ18O, ± 1 ‰ for δ2H, ± 2 ‰ for d-excess, and ± 15 per meg for Δ17O.

Investigating public support for biosecurity measures to mitigate pathogen transmission through the herpetological trade.

The expanding global trade in herpetofauna has contributed to new infectious disease dynamics and pathways that allow for the rapid spread of pathogens geographically. Improved biosecurity is needed to mitigate adverse biodiversity, economic and human health impacts associated with pathogen transmission through the herpetological trade. However, general lack of knowledge of the pathogen transmission risks associated with the global trade in herpetofauna and public opposition to biosecurity measures are critical obstacles to successfully preventing pathogen transmission. In 2019 we administered a survey to 2,007 members of the public in the United States of America to ascertain their support for interventions to prevent the spread of Batrachochytrium dendrobatidis (Bd), Batrachochytrium salamandrivorans (Bsal), ranaviruses, and Salmonella through the herpetological trade. We presented survey respondents with different potential hazards associated with pathogen transmission through this trade, namely ecological, economic, and human health impacts. We used structural equation models to determine how these different hazards and respondents' characteristics influenced respondents' support for quarantine and veterinary observation of herpetofauna imported into the United States, mandatory tests for diseases of concern, and best practices to reduce stress and improve the care of live herpetofauna during transport to the United States. Respondents' values and their perceived susceptibility and sensitivity to different hazards associated with pathogen transmission were key determinants of their support for biosecurity. Respondents with strong biospheric and altruistic values demonstrated sensitivity to ecological and human health impacts associated with pathogen transmission, whereas respondents with strong egoistic values demonstrated sensitivity to economic impacts. Respondents had limited knowledge of Bd, Bsal or ranaviruses, the size of the herpetological trade, or how this trade may contribute to pathogen transmission. Improved outreach and education on pathogen transmission through the herpetological trade is required, but it is important that messages are tailored to people with different values to elicit their support for biosecurity.

Treatment Outcomes for Military Veterans With Posttraumatic Stress Disorder: Response Trajectories by Symptom Cluster.

Although effective posttraumatic stress disorder (PTSD) treatments are available, outcomes for veterans with PTSD are relatively modest. Previous researchers have identified subgroups of veterans with different response trajectories but have not investigated whether PTSD symptom clusters (based on a four-factor model) have different patterns of response to treatment. The importance of this lies in the potential to increase treatment focus on less responsive symptoms. We investigated treatment outcomes by symptom cluster for 2,685 Australian veterans with PTSD. We used Posttraumatic Stress Disorder Checklist scores obtained at treatment intake, posttreatment, and 3- and 9-month follow-ups to define change across symptom clusters. Repeated measures effect sizes indicated that arousal and numbing symptoms exhibited the largest changes between intake and posttreatment, dRM = -0.61 and dRM = -0.52, respectively, whereas avoidance and intrusion symptoms showed more modest reductions, dRM = -0.36 and dRM = -0.30, respectively. However, unlike the other symptom clusters, the intrusions cluster continued to show significant changes between posttreatment and 3-month follow-up, dRM = -0.21. Intrusion and arousal symptoms also showed continued changes between 3- and 9-month follow-ups although these effects were very small, dRM = -0.09. Growth curve model analyses produced consistent findings and indicated modest initial changes in intrusion symptoms that continued posttreatment. These findings may reflect the longer time required for emotional processing, relative to behavioral changes in avoidance, numbing, and arousal, during the program; they also reinforce the importance of prioritizing individual trauma-focused therapy directly targeting intrusions as the core component of programmatic treatment.

Prediction of Late-Onset Psychiatric Disorder in Survivors of Severe Injury: Findings of a Latent Transition Analysis.

OBJECTIVE: There is a growing body of evidence indicating that late or delayed onset of psychiatric disorder following traumatic injury and other psychological trauma is common. This research, however, has not examined factors that pose risks for delayed development of different types of psychopathology or at different time points. Such research has considerable implications for the development of screening, assessment, and intervention practices. This article investigates risk factors for late-onset disorders up to 72 months after a severe injury. METHODS: In this 6-year longitudinal study, 1,167 hospitalized patients with severe injury recruited between April 2004 and February 2006 were analyzed with repeated measures at 3, 12, and 72 months after injury. The Mini-International Neuropsychiatric Interview (MINI) and Clinician-Administered PTSD Scale (CAPS) were employed to complete diagnoses according to DSM-IV. Latent transition analyses with continuous covariates (injury severity, social support, recent life events, and pain) and 1 dichotomous covariate (presence/absence of a psychiatric disorder before injury) were conducted to identify risk factors for transitioning out of a No Disorder class and into one of 3 previously reported psychopathology classes (PTSD [posttraumatic stress disorder]/Depression, Alcohol/Depression, and Alcohol only) between 3 and 12 months (transition 1) and between 12 and 72 months (transition 2) postinjury. RESULTS: Movement into the PTSD/Depression class was predicted by injury severity at transitions 1 (P = .003) and 2 (P = .017) and social support (P = .006) at transition 1. Past psychiatric history increased the likelihood of moving into the PTSD/Depression class, with anxiety or mood disorders specifically implicated in transition 1. Movement into the Alcohol/Depression class was predicted by social support at transitions 1 (P = .008) and 2 (P < .001) and also by injury severity (P < .001) and pain (P < .001) at transition 2. Movement into the Alcohol class was predicted only by pain (P = .011) at transition 2. A history of a substance use or alcohol use disorder before injury was implicated in movement into both of the alcohol-based classes. CONCLUSIONS: Predictors of developing a delayed-onset psychiatric disorder after severe injury differed by duration after injury and class of disorder. These findings highlight the need to offer targeted screening based on these risk factors to severe injury survivors up to 12 months postinjury, even when they present without disorder at 3 months.