Satyrization in Drosophila fruitflies

The satyr of Greek mythology was half-man, half-goat, with an animal persona signifying immoderate sexual appetites. In biology, satyrization is the disruption of reproduction in matings between closely related species. Interestingly, its effects are often reciprocally asymmetric, manifesting more strongly in one direction of heterospecific mating than the other. Heterospecific matings are well known to result in female fitness costs due to the production of sterile or inviable hybrid offspring and can also occur due to reduced female sexual receptivity, lowering the likelihood of any subsequent conspecific matings. Here we investigated the costs and mechanisms of satyrization in the Drosophila melanogaster species subgroup of fruitflies. The results showed that D. simulans females experienced higher fitness costs from a loss of remating opportunities due to significantly reduced post-mating sexual receptivity than did D. melanogaster females, as a result of reciprocal heterospecific matings. Reciprocal tests of the effects of male reproductive accessory gland protein (Acp) injections on female receptivity in pairwise comparisons between D. melanogaster and five other species within the melanogaster species subgroup revealed significant post-mating receptivity asymmetries. This was due to variation in the effects of heterospecific Acps within species with which D. melanogaster can mate, and significant but nonasymmetric Acp effects in species with which it cannot. We conclude that asymmetric satyrization due to post-mating effects of Acps may be common among diverging and hybridising species. The findings are of interest in understanding the evolution of reproductive isolation and species divergence

The Epidemiology of Fatal road traffic Collisions in Trinidad and Tobago, West Indies (2000–2011)

Summary of what was known• Few studies on road traffic collisions conducted in Latin American and the Caribbean region• Increasing car ownership within the region• Lack of seatbelt usage in Trinidad• Most accidents are associated with alcohol usage• High mortality among pedestriansSummary of what this study adds• Most collisions occur at night• Most collisions occur at weekends• Collisions are evenly distributed throughout the year• More males than females die in fatal collisions• The most productive age group (15–44) is affected the most• More drivers than pedestrians are affected• Reflects the pattern of developed rather than developing countries with respect to time of day for RTCs Background: The purpose of the study is to determine the epidemiology of road traffic collisions (RTCs) in Trinidad and Tobago by characterizing RTCs in terms of number of collisions, fatalities, victim profiles, and locations for the purpose of informing accident prevention programs. Previous studies of RTCs in Trinidad and Tobago were primarily concerned with patterns of drivers use of seat belts, road collisions as a cause of mortality in young men, and the economic burden of road collisions. Attempts were made to model road fatalities, but limited epidemiological data meant that it was difficult to determine trends or develop models. Methods: This study determined the epidemiology of RTCs in Trinidad and Tobago over the period 2000–2011using data collected by the Trinidad and Tobago Road Traffic Branch of the Police Service and secondary data from the Central Statistical Office. Data were analyzed using Excel, SPSS, and R statistical packages. Results: Fatalities were greater among men (80%) than among women (20%) and were highest on two major freeways in Trinidad [the Churchill–Roosevelt Highway and the Sir Solomon Hochoy Highway]. Most collisions occurred during the night among individuals between the ages of 15 and 44 years. Fatalities among drivers steadily increased over the study period and overtook fatalities among pedestrians, who were the group most affected in 2000. Most fatalities occurred at weekends. Conclusions: These patterns can inform (i) education programs and (ii) road and traffic control measures

Charlotteville Bioblitz 2015 Final Report

No abstract available

Port of Spain Bioblitz 2016 Final Report

No abstract available

Significant effects of host dietary guild and phylogeny in wild lemur gut microbiomes.

Mammals harbor diverse gut microbiomes (GMs) that perform critical functions for host health and fitness. Identifying factors associated with GM variation can help illuminate the role of microbial symbionts in mediating host ecological interactions and evolutionary processes, including diversification and adaptation. Many mammals demonstrate phylosymbiosis-a pattern in which more closely-related species harbor more similar GMs-while others show overwhelming influences of diet and habitat. Here, we generated 16S rRNA sequence data from fecal samples of 15 species of wild lemurs across southern Madagascar to (1) test a hypothesis of phylosymbiosis, and (2) test trait correlations between dietary guild, habitat, and GM diversity. Our results provide strong evidence of phylosymbiosis, though some closely-related species with substantial ecological niche overlap exhibited greater GM similarity than expected under Brownian motion. Phylogenetic regressions also showed a significant correlation between dietary guild and UniFrac diversity, but not Bray-Curtis or Jaccard. This discrepancy between beta diversity metrics suggests that older microbial clades have stronger associations with diet than younger clades, as UniFrac weights older clades more heavily. We conclude that GM diversity is predominantly shaped by host phylogeny, and that microbes associated with diet were likely acquired before evolutionary radiations within the lemur families examined

Application of Object Based Classification and High Resolution Satellite Imagery for Savanna Ecosystem Analysis

Savanna ecosystems are an important component of dryland regions and yet are exceedingly difficult to study using satellite imagery. Savannas are composed are varying amounts of trees, shrubs and grasses and typically traditional classification schemes or vegetation indices cannot differentiate across class type. This research utilizes object based classification (OBC) for a region in Namibia, using IKONOS imagery, to help differentiate tree canopies and therefore woodland savanna, from shrub or grasslands. The methodology involved the identification and isolation of tree canopies within the imagery and the creation of tree polygon layers had an overall accuracy of 84%. In addition, the results were scaled up to a corresponding Landsat image of the same region, and the OBC results compared to corresponding pixel values of NDVI. The results were not compelling, indicating once more the problems of these traditional image analysis techniques for savanna ecosystems. Overall, the use of the OBC holds great promise for this ecosystem and could be utilized more frequently in studies of vegetation structure

Arima Valley Bioblitz 2013 Final Report

The second Trinidad & Tobago Bioblitz was conducted 21-22 September 2013, in the Arima Valley, Trinidad, West Indies (W.I.). More than 100 volunteers helped observe, collect, and identify a diverse range of organisms: plants, fungi, birds, mammals, reptiles, amphibians, terrestrial invertebrates and freshwater organisms. A variety of surveying methods was used, including direct observation, trapping, netting and sampling. More than 150 members of the public came to watch the volunteers work, visit information stands staffed by members of various organisations, and take part in guided walks. A total of 740 species of organisms were reported after 24 hours of surveying; this total was updated to 771 after further analysis of specimens and results

Nariva Swamp Bioblitz 2014 Final Report

The third Trinidad & Tobago Bioblitz was conducted 18–19 October 2014 in the Nariva Swamp, Trinidad & Tobago. More than 100 volunteers helped observe, collect, and identify a diverse range of organisms: plants, fungi, birds, mammals, reptiles, amphibians, terrestrial invertebrates and aquatic organisms. A variety of surveying methods was used, including direct observation, trapping, netting and sampling. More than 100 members of the public came to watch the volunteers work, visit information stands staffed by members of various organisations, and take part in guided walks. A total of 742 species of organisms were reported after 24 hours of surveying; this total was corrected to 737 after further analysis of specimens and results