Phylogeography of the Endangered Franciscana Dolphin: Timing and Geological Setting of the Evolution of Populations

Pontoporia blainvillei (Gervais & d’Orbigny, 1844), the franciscana dolphin, is the most endangered small cetacean in the Western South Atlantic. It is an endemic species with a coastal and estuarine distribution that has been divided into four Franciscana Management Areas (FMAs). We used the mitochondrial DNA control region to conduct a phylogeographic analysis to evaluate the population structure of the franciscana and the influence of paleoceanographic events on its biogeographic history. We found nine populations along the entire distribution (Φ_ST?=?0.41, Φ_CT?=?0.38, p?<?10^–5), with estimated migration rates resulting in less than one female per generation. Populations from FMAIII and FMAIV in the south (including the Río de La Plata Estuary) showed higher long-term migration rates and effective population sizes than northern populations. The phylogeographic analysis supports the franciscana origin in the Río de La Plata Estuary, with further dispersal south and northwards. The first lineage split happened around 2.5 Ma, with lineage radiation throughout the Pleistocene until recent fragmentation events shaped current-day populations. We suggest that Pleistocene glaciations influenced the dispersion and population structure of the franciscana. Specifically, that the shift of the Brazil-Malvinas Confluence drove the dispersion northwards. Then, low sea-level periods caused either the isolation in estuarine refugia or local extinctions, followed by re-colonizations.

     

Lipoprotein-Associated Phospholipase A2 Activity Predicts Cardiovascular Events in High Risk Coronary Artery Disease Patients

Objective

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is deemed to play a role in atherosclerosis and plaque destabilization as demonstrated in animal models and in prospective clinical studies. However, most of the literature is either focused on high-risk, apparently healthy patients, or is based on cross sectional studies. Therefore, we tested the hypothesis that serum Lp-PLA2 mass and activity are useful for predicting cardiovascular (CV) events over the coronary atherosclerotic burden and conventional risk factors in high-risk coronary artery disease patients.

Methods and Results

In a prospective cohort study of 712 Caucasian patients, who underwent coronary angiography and measurement of both Lp-PLA2 mass and activity at baseline, we determined incident CV events at follow-up after splitting the patients into a high and a low Lp-PLA2 mass and activity groups based on ROC analysis and Youden index. Kaplan-Meier and propensity score matching analysis were used to compare CV event-free survival between groups. Follow-up data were obtained in 75% of the cohort after a median of 7.2 years (range 1–12.7 years) during which 129 (25.5%) CV events were observed. The high Lp-PLA2 activity patients showed worse CV event-free survival (66.7% vs. 79.5%, p = 0.023) and acute coronary syndrome-free survival (75.4% vs. 85.6%, p = 0.04) than those in low Lp-PLA2 group.

Conclusions

A high Lp-PLA2 activity implies a worse CV prognosis at long term follow up in high-risk Caucasian patients referred for coronary angiography.     

Preliminary appraisal of an innovative hydraulic dredge with vibrating and sorting bottom on clam beds (Chamelea gallina)

To solve some of the efficiency and environmental problems related to the use of the hydraulic dredge in bivalve mollusc fishing, a new experimental gear with vibrating bottom grid and other technical changes has been tested on clam (Chamelea gallina) beds in the Adriatic Sea. Comparative fishing surveys indicate a significantly different selectivity of the vibrating dredge, with respect to a standard gear: in fact, undersize clams are sieved out during the fishing process, and almost no juveniles are hauled. Regarding the product quality, laboratory analyses show that the amount of intervalvar sediment is significantly lower in the catch from the modified dredge, due to a sort of `warning' device. Nevertheless, the larger number of damaged shells suggests that the vibrating grid subjects the clams to a greater mechanical stress than the standard gear. As for the environmental effects, the vibrating bottom is selective for the associated fauna too, as is shown by the higher mean weight of most the by-catch species in the experimental gear. Moreover, the riddling goes on continuously, allowing the immediate release of the sorted-out organisms, which are repositioned in the area of origin, thus avoiding a `contagious' distribution. In conclusion, these positive preliminary results suggest real benefits of this innovative modified dredge, with wide margins for further improvement.