ABSTRACT
The use of fish aggregation devices (FADs) can increase catchability of tuna purse seine for associated tuna schools. In the past decades, large scale deployments of FADs have drawn the international attention due to their negative effects on the marine environment. Finding a FAD design ecologically and economically compatible has therefore become a challenge for tuna purse seine fishe-ry. Nowadays, knowledge and comprehension of interaction between FADs and catch species are quite lacking as a result of limited experimental investigation. We interviewed the captain of Chinese tuna purse seiner based on questionnaire to summarize the status of FADs deployment strategy, structural design, capture and ecological characteristics, and the behavior characteristics of associa-ted schools from the perspective of fishermen's knowledge and experience. We also quantified the cognitive differences of the investigated issues based on the index of consistency (IoC). Our results showed that: 1) the average number of year-round FADs deployment was (102±37) per vessel, and the number of that being lost was (72±1). 2) empirical knowledge from fishing masters indicated that man-made FADs could attract more tuna than natural floating objects (e.g. logs). Submerged structure was the predominant mechanism for aggregating tunas around the FADs. Hanging attractors (e.g. palm leaves) would facilitate the aggregation of tunas. 3) Fishing masters' observations in practical operation revealed that the duration needed for tunas to be associated with a FAD was around 32 days, and fish aggregation would tend to stabilize in the following month. Entanglement of sea turtles and sharks by netting was incidental events. 4) Most fishing masters had identical opinion on "bio-fouling was helpful for FADs to attract tunas" (IoC=0.73) and "modifying FADs design to reduce the detectability by other vessels" (IoC=0.73), while the answers for "the effect of raft type on tuna attraction capability" (IoC=0.34) were quite different. 5) The results of questionnaire suggested that the current design of FADs used by Chinese tropical tuna purse seiner had high risks of detected by other vessels and increased vulnerability of non-target species to fishery. Moreover, our results provided valuable references that promote sustainable exploitation of purse seine in a way of reconciling profitability with ecological preservation.
Subject(s)
Fisheries , Sharks , Animals , Asian People , Humans , Schools , TunaABSTRACT
BACKGROUND: Propofol has been reported to protect vascular endothelial cells against oxidative stress. In this study we investigated its effect on hydrogen peroxide (H2O2)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and examined the possible signaling pathways. METHODS: HUVECs were pretreated with propofol (1, 5, 25, and 50 µM) for 30 min and then co-incubated with 0.4 mM H2O2 for 4 h. Cell viability was assessed using a Cell Counting Kit-8. Cell apoptosis was analyzed using flow cytometry with annexin V/propidium iodide staining, and evaluated by quantifying caspase-3, Bax, and Bcl-2 expression levels. The expression levels of p38 mitogen activated protein kinase (MAPK), phosphorylated (p)-p38 MAPK, cJun-N-terminal kinases (JNK), phosphorylated (p)-JNK, Akt and phosphorylated Akt [(p)-Akt] (Ser473) were measured by western blotting. RESULTS: H2O2 treatment induced the activation of caspase-3, downregulated Bcl-2 expression, and up-regulated Bax expression, all of which were dose-dependently attenuated by propofol pretreatment. Furthermore, propofol significantly ameliorated H2O2-induced phosphorylation of p38 MAPK, JNK, and Akt in HUVECs. CONCLUSIONS: Propofol can protect HUVECs against H2O2-induced apoptosis via a mechanism that may involve p38 MAPK, JNK, and Akt signaling pathways.
ABSTRACT
Propofol is a widely used intravenous anesthetic agent with antioxidant/antiapoptotic properties. Aldose reductase (AR) has been implicated in oxidative stress and apoptosis in endothelial cells. AR inhibition may protect cells from cardiovascular injury. Although the cytoprotective effect of propofol against hydrogen peroxide (H2O2)-induced injury has been widely studied, there is no information about the effects of propofol on AR. We therefore investigated the effect of propofol on H2O2-mediated injury and on aldose reductase expression. We found that propofol protected HUVECs against H2O2-induced damage and apoptosis and ameliorated AR expression induced by H2O2. Propofol also inhibited H2O2-induced p38 MAPK, JNK and Akt phosphorylation. Epalrestat (an AR inhibitor) or ablation of AR siRNA had a similar effect to propofol. The results suggest that propofol may be a preemptive anesthetic in patients with cardiovascular disease and inhibition of AR might be a new cytoprotective pathway for propofol.
