Gene flow at three spatial scales in a coral reef fish, the three-spot dascyllus, Dascyllus trimaculatus

Dispersal in coral reef fishes occurs predominantly during the larval planktonic stage of their life cycle. With relatively brief larval stages, damselfishes (Pomacentridae) are likely to exhibit limited dispersal. This study evaluates gene flow at three spatial scales in one species of coral reef damselfish, Dascyllus trimaculatus. Samples were collected at seven locations at Moorea, Society Islands, French Polynesia. Phylogenetic relationships and gene flow based on mitochondrial control region DNA sequences between these locations were evaluated (first spatial scale). Although spatial structure was not found, molecular markers showed clear temporal structure, which may be because pulses of settling larvae have distinct genetic composition. Moorea samples were then compared with individuals from a distant island (750 km), Rangiroa, Tuamotu Archipelago, French Polynesia (second spatial scale). Post-recruitment events (selection) and gene flow were probably responsible for the lack of structure observed between populations from Moorea and Rangiroa. Finally, samples from six Indo-West Pacific locations, Zanzibar, Indonesia, Japan, Christmas Island, Hawaii, and French Polynesia were compared (third spatial scale). Strong population structure was observed between Indo-West Pacific populations. Received: 26 May 2000 / Accepted: 10 October 2000     

Heat stress and crop yields in the Mediterranean basin: impact on expected insurance payouts

Insurance programmes have been indicated as a tool to reduce the economic risk associated with climate change, and crop growth simulation models can be used effectively to assess future trends in crop insurance payouts. This paper assesses the economic role of increasing weather extremes under future climate change on the expected insurance payouts for durum wheat (Triticum turgidum L. spp. durum) over the Mediterranean basin, focusing attention on the effects of heat stresses (HSs). A crop growth simulation, Sirius Quality version 2 (SQ2), calibrated for three varieties (long, medium and short growth cycle) was applied on seven sites under present (1975–1990) and future climate conditions (2030–2050) obtained from five regional circulation models under SRES scenario A1b. The intensity of HSs at anthesis was included as reducing factor of yield originally simulated by SQ2 calculated according to a specific empirical model. Simulated yields were then fitted to the most appropriate distribution, which was used to calculate the expected payouts according to the probability of yields being below a guaranteed level. We found that the simulated crop yields were, in general, negatively skewed and that Weibull probability density function (PDF), admitting negative skewing, provided the best performances in their fitting. The simulation of HSs modified the original shape of the Weibull PDF by increasing the skewness of the distribution. The results of the insurance model indicated that the modification of crop PDFs induced by HSs led to a general increase in payouts with respect to unstressed conditions, with a marked difference between present (+11 %, on average for the selected sites) and future periods (+25 %). When compared to the present, a general decrease in payouts (?1.1 %) was observed when HSs were not included in the simulations. Conversely, HSs impact resulted in a general increase in payouts (+10.3 %) where the highest increase was detected for the long growth cycle variety (+16.6 %) and the lowest for that with short growth cycle (?1.6 %). These results emphasize the importance of the appropriate characterization of crop yield distribution, the economic implications of HSs in a risk management context and a possible strategy to cope with climate change and variability.     

Risk factors associated with bus accident severity in the United States: A generalized ordered logit model

IntroductionRecent years have witnessed a growing interest in improving bus safety operations worldwide. While in the United States buses are considered relatively safe, the number of bus accidents is far from being negligible, triggering the introduction of the Motor-coach Enhanced Safety Act of 2011.MethodThe current study investigates the underlying risk factors of bus accident severity in the United States by estimating a generalized ordered logit model. Data for the analysis are retrieved from the General Estimates System (GES) database for the years 2005–2009.ResultsResults show that accident severity increases: (i) for young bus drivers under the age of 25; (ii) for drivers beyond the age of 55, and most prominently for drivers over 65 years old; (iii) for female drivers; (iv) for very high (over 65 mph) and very low (under 20 mph) speed limits; (v) at intersections; (vi) because of inattentive and risky driving.     

Analysis of individual year-classes of a marine fish reveals little evidence of first-generation hybrids between cryptic species in sympatric regions

As settled juveniles and adults, blue rockfish (Sebastes mystinus) are nonmigratory inhabitants of kelp and rocky reef habitats along the California coast, USA, and prior to settlement, they possess a pelagic larval and juvenile stage lasting 3–5 months. A previous study of adults revealed two cryptic species within S. mystinus and evidence of reproductive isolation in a region where both cryptic adults co-occur. Given this pattern of reproductive isolation, we investigated the degree of hybridization or introgression in individual year-classes shortly after juvenile settlement in two different years (2001 and 2002). Using microsatellite markers, we found little indication of hybridization in new juvenile year-classes despite an adult population that comprised both cryptic species. However, we found an average of two percent of hybrid or introgressed individuals in regions with a low frequency of one of the two species. Therefore, while the lack of hybrids or introgression supports the hypothesis of reproductive isolation between the cryptic species within S. mystinus, the age-structured analysis also revealed a spatial pattern of low-frequency differences in the number of introgressed individuals. These results suggest that reproductive barriers may breakdown when one of the two species predominates the regional adult gene pool.     

Autotrophic nitrogen removal for decentralized treatment of ammonia-rich industrial textile wastewater: process assessment,stabilization and modelling

Environmental Science and Pollution Research - Digital textile printing (DTP) is a game-changer technology that is rapidly expanding worldwide. On the other hand, process wastewater is rich in...     

Application of domino effect quantitative risk assessment to an extended industrial area

Escalation of primary accidental scenarios triggering a “domino effect” have caused extremely severe accidental events in the chemical and process industry. The identification of possible escalation events is required in the safety assessment of sites where relevant quantities of hazardous substances are stored or handled. In the European Union, “Seveso-II” Directive requires the assessment of on-site and off-site possible escalation scenarios in sites falling under the obligations of the Directive. In the present study, a methodology developed for the quantitative assessment of risk due to domino effect was applied to the analysis of an extended industrial area. Recently developed equipment damage probability models were applied for the identification of the final scenarios and for escalation probability assessment. The domino package of the Aripar-GIS software was used for risk recomposition. The results evidence that quantitative risk assessment of escalation hazard is of fundamental importance in order to identify critical equipment and to address prevention and protection actions.     

Plants as indicators of urban air pollution (ozone and trace elements) in Pisa, Italy

A biennial integrated survey, based on the use of vascular plants for the bioindication of the effects of tropospheric ozone, was performed in the area of Pisa (Tuscany, Central Italy). It also investigated the distribution of selected trace elements in plants and the data were compared with those obtained from the use of passive samplers, automatic analysers of ozone and lichen biodiversity. Photochemically produced ozone proved to be present during the warm season, with maximum hourly means surpassing 100 ppb: the use of supersensitive tobacco Bel-W3 confirmed the value of detailed, cost-effective, monitoring surveys. Trials with clover clones demonstrate that sensitive plants undergo severe biomass reduction in the current ozone regime. The mean NC-S (clover clone sensitive to ozone):NC-R (resistant) biomass ratio ranged from 0.7 (in 1999) to 0.5 (in 2000). The economic impact of these reductions deserves attention. The data obtained using passive ozone samplers exceeded those obtained using an automatic analyser. The mapping of epiphytic lichen biodiversity was not related to the geographical ozone distribution as can be seen from the tobacco's response. Lettuce plants grown under standardized conditions were used positively as bioaccumulators of trace elements: Pb was abundantly recovered, but a large portion of this element was removed by washing.     

Bisphenol A and Bisphenol S release in milk under household conditions from baby bottles marketed in Italy

A simple and sensitive validated analytical method based on liquid chromatography coupled to tandem fluorescence (FD) and ultraviolet (UV) spectrophotometry was applied to monitor the presence of bisphenol A and bisphenol S in plastic baby bottles marketed in Italy. The limits of detection (LOD) were 3.75 ng mL^?1 and 80.00 ng mL^?1, and those of quantification (LOQ) were 12.51 ng mL^?1 and 260.00 ng mL^?1 for BPA (FD detection) and for BPS (UV detection), respectively. BPA was found in only four samples, two samples undergone to microwave heating and two samples undergone to bottle warmer heating either at 40°C or at 80°C. Although the quantities of leached BPA were well below the reference dose for daily intake established by the European Food Safety Authority (EFSA) (4.0 µg kg^?1 bw/day), the release of BPA and BPS from these plastic materials should be carefully considered by the government authorities to increase people's awareness on this issue and to protect the most vulnerable population group.