Prior exposure to weathered oil influences foraging of an ecologically important saltmarsh resident fish

Estuarine ecosystem balance typically relies on strong food web interconnectedness dependent on a relatively low number of resident taxa, presenting a potential ecological vulnerability to extreme ecosystem disturbances. Following the Deepwater Horizon (DwH) oil spill disaster of the northern Gulf of Mexico (USA), numerous ecotoxicological studies showed severe species-level impacts of oil exposure on estuarine fish and invertebrates, yet post-spill surveys found little evidence for severe impacts to coastal populations, communities, or food webs. The acknowledgement that several confounding factors may have limited researchers’ abilities to detect negative ecosystem-level impacts following the DwH spill drives the need for direct testing of weathered oil exposure effects on estuarine residents with high trophic connectivity. Here, we describe an experiment that examined the influence of previous exposure to four weathered oil concentrations (control: 0.0 L oil m−2; low: 0.1 L oil m−2; moderate: 0.5–1 L oil m−2; high: 3.0 L oil m−2) on foraging rates of the ecologically important Gulf killifish (Fundulus grandis). Following exposure in oiled saltmarsh mesocosms, killifish were allowed to forage on grass shrimp (Palaeomonetes pugio) for up to 21 h. We found that previous exposure to the high oil treatment reduced killifish foraging rate by ~37% on average, compared with no oil control treatment. Previous exposure to the moderate oil treatment showed highly variable foraging rate responses, while low exposure treatment was similar to unexposed responses. Declining foraging rate responses to previous high weathered oil exposure suggests potential oil spill influence on energy transfer between saltmarsh and off-marsh systems. Additionally, foraging rate variability at the moderate level highlights the large degree of intraspecific variability for this sublethal response and indicates this concentration represents a potential threshold of oil exposure influence on killifish foraging. We also found that consumption of gravid vs non-gravid shrimp was not independent of prior oil exposure concentration, as high oil exposure treatment killifish consumed ~3× more gravid shrimp than expected. Our study findings highlight the sublethal effects of prior oil exposure on foraging abilities of ecologically valuable Gulf killifish at realistic oil exposure levels, suggesting that important trophic transfers of energy to off-marsh systems may have been impacted, at least in the short-term, by shoreline oiling at highly localized scales. This study provides support for further experimental testing of oil exposure effects on sublethal behavioral impacts of ecologically important estuarine species, due to the likelihood that some ecological ramifications of DwH on saltmarshes likely went undetected.

Growth of Falcataria moluccana and Albizia chinensis seedling under aluminum exposure

Salim MA, Setyaningsih L, Wahyudi I, Budi SW. 2021. Growth of Falcataria moluccana and Albizia chinensis seedling under aluminum exposure. Biodiversitas 22: 3693-3701. Aluminum (Al) is an element found in acid soils and is one of the limiting factors for plant growth. This study aims to examine the growth of Falcataria moluccana (Miq.) Barneby & J.W.Grimes and Albizia chinensis (Osbeck) Merr seedlings under exposure of aluminum. This study used an one-factor completely randomized design (Al concentration) consisting of 5 levels, namely 0, 2, 4, 6, and 8 mM. Each treatment was repeated 3 times and each replication consisted of 3 plant units. The results showed that the Al exposure treatment gave significant differences in the growth of height, root length, dry weight (root, shoot, and total) of F. moluccana and A. chinensis seedlings. The 2 mM Al concentration stimulated the growth of height, root length and dry weight (root, shoot, and total) of A. chinensis seedlings. The tolerance index for F. moluccana and A. chinensis seedlings was highest when the Al 2 mM concentration was 147.55% and 115.32%, respectively. 2 mM Al exposure treatment increased the chlorophyll content a, b, total chlorophyll and carotenoids of F. moluccana and A. chinensis seedlings. Al exposure treatment did not significantly differ from the rate of photosynthesis and MDA content in F. moluccana and A. chinensis seedlings. The Al content in the roots was higher than in the shoots, and the increase in Al concentration increased the Al content in the roots and shoots of F. moluccana and A. chinensis seedlings.

The enhancing effects of testosterone in exposure treatment for social anxiety disorder: a randomized proof-of-concept trial

Individuals with a social anxiety disorder (SAD) show hypofunctioning of the hypothalamus–pituitary-gonadal (HPG) axis, which is linked to social fear and avoidance behavior. As testosterone administration has been shown to facilitate social-approach behavior in this population, it may enhance the effectiveness of exposure treatment. In this proof-of-concept study, we performed a randomized clinical assay in which 55 women diagnosed with SAD received two exposure therapy sessions. Session 1 was supplemented with either testosterone (0.50 mg) or placebo. Next, transfer effects of testosterone augmentation on within-session subjective fear responses and SAD symptom severity were assessed during a second, unenhanced exposure session (session 2) and at a 1-month follow-up, respectively. The participants having received testosterone showed a more reactive fear pattern, with higher peaks and steeper reductions in fear levels in session 2. Post-hoc exploration of moderating effects of endogenous testosterone levels, revealed that this pattern was specific for women with high basal testosterone, both in the augmented and in the transfer session. In contrast, the participants with low endogenous testosterone showed reduced peak fear levels throughout session 1, again with transfer to the unenhanced session. Testosterone did not significantly affect self-reported anxiety. The effects of testosterone supplementation on fear levels show transfer to non-enhanced exposure, with effects being modulated by endogenous testosterone. These first preliminary results indicate that testosterone may act on important fear mechanisms during exposure, providing the empirical groundwork for further exploration of multi-session testosterone-enhanced exposure treatment for SAD.

Does Concentrated Exposure Treatment for Obsessive-Compulsive Disorder Improve Insomnia Symptoms? Results From a Randomized Controlled Trial

Insomnia is a substantial problem in patients with obsessive-compulsive disorder (OCD). There is, however, a lack of studies investigating changes in concurrent symptoms of insomnia in OCD after concentrated treatment. A recent randomized controlled trial randomized participants to the Bergen 4-day treatment (B4DT, n = 16), or 12 weeks of unguided self-help (SH, n = 16), or waitlist (WL, n = 16). Patients from the SH- and WL-group who wanted further treatment after the 12 weeks were then offered the B4DT (total of 42 patients treated with the B4DT). There were no significant differences in symptoms of insomnia between the conditions at post-treatment, but a significant moderate improvement at 3-month follow-up for patients who received the B4DT. Insomnia was not associated with OCD-treatment outcome, and change in symptoms of insomnia was mainly related to changes in depressive symptoms. The main conclusion is that concentrated exposure treatment is effective irrespective of comorbid insomnia, and that insomnia problems are moderately reduced following treatment.

Exposure-enhanced cognitive behavioral therapy for adolescents with binge eating: An initial case series

Binge eating (BE) often develops during adolescence and is associated with deleterious psychological and physical consequences. Current treatments for adolescents achieve suboptimal results, likely due to failure to adequately address fear of weight gain (FOWG) which maintains BE. Thus, exposure treatment (the most powerful intervention for fear) may be a promising approach. However, exposure treatment has only minimally tested in adults with BE and never tested in adolescents. Thus, the current study is the first to evaluate a 4-session exposure module within a 12-session standard cognitive behavioral therapy for adolescents with BE. We recruited adolescents with BE ( N = 5) and examined treatment feasibility, acceptability, and preliminary effects on FOWG and eating pathology. Overall, the 4-session exposure module was feasible and acceptable and showed preliminary evidence that it could reduce FOWG. However, several participants did not endorse significant fears of weight gain; rather, these participants reported that fears of deprivation or social judgment were more related to their BE. Future research should test higher doses of exposure and further examine the role of fear of deprivation/social judgment. Finally, future iterations of this treatment could include more parent involvement or test exposure in combination with treatments other than cognitive behavioral therapy, such as family-based treatment.

Treatment Adherence as Predictor of Outcome in Concentrated Exposure Treatment for Obsessive-Compulsive Disorder

Background: The treatment of choice for obsessive-compulsive disorder (OCD) is exposure and response prevention (EX/RP). Previous studies have demonstrated that treatment adherence predicts treatment outcome for patients with OCD, but there is little knowledge on its role in concentrated exposure treatment for OCD.Method: In the present study, 42 patients received EX/RP treatment using the Bergen 4-day format. Adherence was measured with the Exposure and Response Prevention Adherence Scale (PEAS, rated both by patients and therapists) after the second and third day. Treatment outcome (symptoms of OCD, depression, anxiety, work- and social functioning, and well-being) was assessed at 3-month follow-up.Results: At follow-up, 71.4% were in remission. High adherence was reported (mean score of 6 on a 1–7 scale). The combination of patient- and therapist rated adherence was significantly associated with treatment outcome whilst controlling for age, sex, and pre-treatment scores. Patients with higher degree of adherence reported less symptoms, higher functioning, and more well-being at follow-up.Conclusions: The results of the present study indicated that adherence in concentrated exposure treatment is significantly associated with a wide range of treatment outcomes for OCD.