Molecular phylogeny and DNA barcoding of tropical eastern Pacific shallow-water gorgonian octocorals

The octocoral fauna inhabiting the shallow waters (<50 m) of the eastern Pacific has been the subject of renewed interest, and the taxonomy of the most important genera in the region has been reviewed and clarified. Many new species have been described, significantly increasing the known biological diversity of the region. Despite their importance as potential sister-groups of Caribbean octocorals, the phylogenetic relationships of eastern Pacific octocorals remain poorly studied. Here, using partial mitochondrial MutS and igr1-COI sequences, we provide a phylogenetic assessment of a broad sample of eastern Pacific shallow-water octocorals and investigate their phylogenetic relationships with Caribbean gorgonians. We corroborate the monophyly of Pacifigorgia, Leptogorgia and Eugorgia and provide evidence of a close relationship between Swiftia and Psammogorgia, currently placed in Plexauridae. In addition, the phylogenies obtained here provide insights into the historical biogeography and phylogenetic diversity of the eastern Pacific octocoral assemblages and on character evolution among this diverse faunal assemblage. Finally, we evaluate the classification power of DNA barcoding for identifying species of shallow-water eastern Pacific octocorals and assess the use of a nuclear intron (SRP54) to supplement traditional mitochondrial barcodes in this group of organisms.     

Ecological drivers of group living in two populations of the communally rearing rodent, Octodon degus

Intraspecific variation in sociality is thought to reflect a trade-off between current fitness benefits and costs that emerge from individuals' decision to join or leave groups. Since those benefits and costs may be influenced by ecological conditions, ecological variation remains a major, ultimate cause of intraspecific variation in sociality. Intraspecific comparisons of mammalian sociality across populations facing different environmental conditions have not provided a consistent relationship between ecological variation and group-living. Thus, we studied two populations of the communally rearing rodent Octodon degus to determine how co-variation between sociality and ecology supports alternative ecological causes of group living. In particular, we examined how variables linked to predation risk, thermal conditions, burrowing costs, and food availability predicted temporal and population variation in sociality. Our study revealed population and temporal variation in total group size and group composition that covaried with population and yearly differences in ecology. In particular, predation risk and burrowing costs are supported as drivers of this social variation in degus. Thermal differences, food quantity and quality were not significant predictors of social group size. In contrast to between populations, social variation within populations was largely uncoupled from ecological differences.     

REAcct: a scenario analysis tool for rapidly estimating economic impacts of major natural and man-made hazards

The REAcct (for Regional Economic Accounting) tool was developed for estimating order-of-magnitude economic impacts within DHS scenario analysis. REAcct uses input–output modeling, geo-spatial data computational tools, and publically available economic data and allows for detailed specification of sectors, regions, and disruption intervals. Direct impacts are estimated as changes in output and employment; total (direct plus indirect) impacts are calculated using regional total and final demand multipliers. In total, the REAcct framework and software allow for scenario analysts to understand and assess the interdependent relationships between critical infrastructures, economic industries, and consumers that are essential to broader homeland security scenario analysis.     

Model selection analysis of temporal variation in benefit for an ant-tended treehopper

Recent studies of mutualism have emphasized both that the net benefit to participants depends on the ecological context and that the density-dependent pattern of benefit is key to understanding the population dynamics of mutualism. Indeed, changes in the ecological context are likely to drive changes in both the magnitude of benefit and the density-dependent pattern of benefit. Despite the close linkage between these two areas of research, however, few studies have addressed the factors underlying variation in the density-dependent pattern of benefit. Here I use model selection to evaluate how variation in the benefits of a mutualism drives temporal variation in the density-dependent pattern of net benefit for the ant-tended treehopper Publilia concava. In the interaction between ants and treehoppers in the genus Publilia, ants collect the sugary excretions of treehoppers as a food resource, and treehoppers benefit both directly (e.g., by feeding facilitation) and indirectly (e.g., by predator protection). Results presented here show that temporal changes in the relative magnitude of direct and indirect benefit components of ant tending, especially the effectiveness of predator protection by ants, qualitatively change the overall pattern of density-dependent benefit between years with maximum benefit shifting from treehoppers in small to large aggregations. These results emphasize the need for empirical studies that evaluate the long-term dynamics of mutualism and theoretical studies that consider the population dynamics consequences of variation in the density-dependent pattern of benefit.     

Biliverdin-based egg coloration is enhanced by carotenoid supplementation

Avian eggshell color is remarkably variable among and within species and its possible function has long been controversial. Female birds use biliverdin pigment to color their eggs blue and green. Although evidence is accumulating that blue-green eggshell coloration is costly to produce, the exact mechanisms underlying its expression are little studied. Biliverdin pigment is involved in important maintenance functions such as immune and antioxidant defenses and shows similar properties to carotenoid pigments. Carotenoids play a role as immunoenhancers and have the potential to ameliorate the impact of oxidative processes, although their antioxidant function could be minor for some bird species. Important life-history components can be limited by carotenoid availability, including sexual displays and fecundity. Here we explored if biliverdin-based eggshell pigmentation was affected by carotenoid availability in a seabird, by performing a carotenoid supplementation experiment in female blue-footed boobies (Sula nebouxii) after laying their first egg. In this species, blue eggshell color is associated with incubation patterns, and carotenoid availability affects the crucial trade-off between female foot ornamentation and fecundity. We found that under natural conditions, there was a decline in eggshell color with laying order, suggesting pigment limitation for females. However, carotenoid-supplemented females had enhanced second egg coloration compared to controls, and the color increase was independent of their previous pigment allocation to the first egg. Our results suggest that biliverdin-based eggshell coloration is costly to produce and can be alleviated by current carotenoid availability.     

Genomic erosion in a demographically recovered bird species during conservation rescue

The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400–480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993–2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations.     

“Modern agriculture” transfers many pesticides to watercourses: a case study of a representative rural catchment of southern Brazil

Environmental Science and Pollution Research - The total cultivated area in Brazil reached to 62 million ha in 2018, with the predominance of genetically modified soybean and corn (36 and 17...     

Simple Model of Dissolved Oxygen Consumption in a Bay within High Organic Loading: An Applied Remediation Tool

San Vicente Bay is a coastal shallow embayment in Central Chile with multiple uses, one of which is receiving wastewater from industrial fisheries, steel mill effluents, and domestic sewage. A simulation model was developed and applied to dissolved oxygen consumption by organic residues released into this embayment. Three compartments were established as function of: depth, circulation and outfall location. The model compartments had different volumes, and their oxygen saturation value was used as baseline. The parameters: (a) BOD₅ of the industrial and urban effluents, (b) oxygen demand by organic sediments, (c) respiration, (d) photosynthesis and (e) re-aeration were included in the model. Iteration results of the model showed severe alterations in Compartment 1, with a decrease of 65% in the oxygen below saturation. Compartment 2 showed a small decline (10%) and compartment 3 did not show apparent changes in oxygen values. Measures recommended for remediation were to decrease the BOD₅ loading by 30% in the affected sector. Iteration of the model for 200 h following recommendations derived from the preceding results produced an increase in saturation of 60% (5 ml O₂ L⁻¹), which suggested an improvement of the environmental conditions.     

The effects of the Fukushima disaster on nuclear energy debates and policies: a two-step comparative examination

Under what conditions do critical events trigger large-scale public discussion and mobilisation, and can these lead to policy change? In a comparative study of nuclear energy policy after the Japanese Fukushima disaster in March 2011, a theory-development approach is adopted, mobilising data collected from national news agencies’ newswires, public surveys, legislation and parliamentary databases, and newspaper editorials in 12 established democracies between March 2011 and March 2013. The analysis suggests two main hypotheses that can guide future research: critical events are more likely to trigger policy change when intense (contentious) mobilisation from policy challengers aligns with the views of the general public, and is backed by major political allies; and critical events are more likely to trigger intense (contentious) mobilisation when policy challengers articulate their opposition around pre-existing policy debates on the issue and resort to pre-existing organisational and mobilisation resources.     

Anti-oviposition activities of used sock media against a dengue vector: prospects of eco-friendly control and solutions to pollution

Yearly, huge amounts of sock refuse are discarded into the environment. Socks contain many molecules, and worn ones, which are rich in smell-causing bacteria, have a strong influence on animals’ behaviors. But the impacts of sock odor on the oviposition behavior of dengue vectors are unknown. We assessed whether Aedes albopictus changes its oviposition activity in response to the presence of used socks extract (USEx) in potential breeding grounds, using choice and no-choice bioassays (NCB). When furnished even chances to oviposit in two sites holding USEx and two others containing water (control), Ae. albopictus deposited significantly less eggs in USEx than in water sites. A similar pattern of oviposition preference was also observed when there were more oviposition options in water. When there were greater oviposition opportunities in USEx sites, Ae. albopictus oviposited preferentially in water. Females laid significantly more eggs during the NCB involving water than USEx. Also, significantly more mature eggs were retained by females in the NCB with USEx than in that with water. These observations strongly suggest the presence of molecules with either repellent or deterrent activities against Ae. albopictus females and provide an impetus to advocate the integration of used socks in dengue control programs. Such applications could be a realistic end-of-life recourse to reroute this waste from landfills.