Exercise, Decision-Making, and Cannabis-Related Outcomes among Adolescents.

OBJECTIVE: Poor decision-making may represent a risk factor for adverse cannabis-related outcomes, whereas exercise has been linked to better executive functioning and substance use outcomes. This study examines the associations between self-reported exercise and cannabis use (CU) outcomes over 6 months among adolescents, and whether these are mediated by exercise-related effects on decision-making. Method: Participants were 387 adolescents aged 15-18 who completed two assessments 6 months apart. Self-reported past 6-month hours/week of exercise were assessed at baseline. At the 6-month follow-up, participants completed measures assessing past 6-month CU frequency, presence of CU disorder (CUD), and CU-related problems, as well as risky decision-making tasks (Iowa Gambling Task, Game of Dice Task, Cups Task), which were used to derive a latent construct of decision-making. We used prospective mediation to examine the role of decision-making in the relationship between exercise and CU outcomes. Results: More self-reported exercise at baseline predicted greater CU frequency at the 6-month follow-up, but did not predict the presence of a CUD, or cannabis-related problems. After controlling for confounds, baseline exercise did not predict better decision-making at follow-up. Decision-making did not predict CU outcomes, and indirect effects of decision-making were not significant. Conclusions: Contrary to hypotheses, adolescents reporting more exercise at baseline also reported higher CU frequency in our sample. This association may be explained by factors like sample characteristics or sports types, but more research is needed to explore this. Results did not support a mediating role for decision-making in the associations between exercise and CU outcomes.Supplemental data for this article can be accessed online at https://doi.org/10.1080/10826084.2021.1906279.

Bioaccumulation and toxic effects of nanoparticulate and ionic silver in Saccostrea glomerata (rock oyster).

The increasing production of Ag nanoparticle (AgNP) containing products has inevitably led to a growing concern about their release into the aquatic environment, along with their potential behaviour, toxicity, and bioaccumulation in marine organisms exposed to NPs released from these products. Hence, this study is focused on the effects of AgNPs in Saccostrea glomerata (rock oyster) in artificial seawater (ASW); evaluating the NP's stability, dissolution, and bioaccumulation rate. AgNPs NM300K (20 ±â€¯5 nm) in concentrations of 12.5 µgL-1 and 125 µgL-1 were used to conduct the experiments, and were compared to a blank and a positive control of 12.5 µgL-1 AgNO3. Dissolution in ASW was measured by ICP-OES and stability was assessed by TEM after 1 h and 3, 5, and 7 days of exposure. Bioaccumulation in gills and digestive glands was measured after 7 days of exposure. The higher concentration of AgNPs induced more aggregation, underwent less dissolution, and showed less bioaccumulation, while the lower concentration showed less aggregation, more dissolution and higher bioaccumulation. Five biomarkers (EROD: ethoxyresorufin-o-deethylase, DNA strand breaks, LPO: lipid peroxidation, GST: glutathione S-transferase and GR: glutathione reductase) were analysed at 0, 3, 5 and 7 days. Significant differences compared to the initial day of exposure (day 0) were reported in DNA strand breaks after 5 and 7 days of exposure, GST, from the third day of exposure, in all the Ag samples, and in some samples for LPO and GR biomarkers, while no significant induction of EROD was observed. A combined effect for each type of treatment and time of exposure was also reported for DNA strand breaks and GST biomarkers measured at the digestive glands. In general, the significant inductions measured showed the following trend: 125 µgL-1 AgNPs >12.5 µgL-1 AgNPs ∼12.5 µgL-1 AgNO3 even though bioaccumulation followed the opposite trend.

An early approach for the evaluation of repair processes in fish after exposure to sediment contaminated by an oil spill.

A chronic bioassay was carried out under laboratory conditions using juvenile Solea senegalensis to determine the toxicity of contaminants from an oil spill(Prestige). Also, the repair processes in fish affected by contaminants due to oil exposure were evaluated. Over 30 days individuals were exposed to clean sediment (control) and to sediment contaminated by a mixture of polyaromatic hydrocarbons (PAHs) and other substances. The physicochemical parameters of the tanks (salinity, temperature, pH and dissolved oxygen) were controlled during the exposure period. Clean sediment from the Bay of Cadiz (Spain) was used as negative control and was mixed with fuel oil to prepare the dilution (0.5% w:w dry-weight). After the exposure period, fish were labeled and transferred to "clean tanks" (tanks without sediment) in order to study the recovery and the repair processes in the exposed organisms. A biomarker of exposure (ethoxyresorufin-O-deethylase activity - EROD activity) and a biomarker of effect (histopathology) were analyzed during the exposure and recovery period. After 10, 20 and 30 days of exposure, individuals showed significant induction (P < 0.05) of the EROD activity and also presented diverse histopathological damages. The analysis of both the biomarkers of exposure and effect, after the 5th and 10th day of recovery in the "clean tank", enabled a first evaluation of the repair process of the induced damages due to the fuel oil exposure. After the recovery phase, control individuals showed a more significant decrease (P < 0.05) of the alteration of the measured biomarkers than in the oil-exposed fish. While in the oil-exposed fish the EROD activity showed some recovery, the histopathological damages did hardly improve. According to our results, tissue repair processes probably need longer recovery periods to observe significant improvement of the affected organs. This will be further investigated in the future.