Air-Sea Exchange of Biogenic Volatile Organic Compounds and the Impact on Aerosol Particle Size Distributions

We report simultaneous, underway eddy covariance measurements of the vertical flux of isoprene, total monoterpenes, and dimethyl sulfide (DMS) over the Northern Atlantic Ocean during fall. Mean isoprene and monoterpene sea-to-air vertical fluxes were significantly lower than mean DMS fluxes. While rare, intense monoterpene sea-to-air fluxes were observed, coincident with elevated monoterpene mixing ratios. A statistically significant correlation between isoprene vertical flux and short wave radiation was not observed, suggesting that photochemical processes in the surface microlayer did not enhance isoprene emissions in this study region. Calculations of secondary organic aerosol production rates (PSOA) for mean isoprene and monoterpene emission rates sampled here indicate that PSOA is on average <0.1 μg m−3 d−1. Despite modest PSOA, low particle number concentrations permit a sizable role for condensational growth of monoterpene oxidation products in altering particle size distributions and the concentration of cloud condensation nuclei during episodic monoterpene emission events from the ocean

Life history and chemical ecology of the Warrior wasp Synoeca septentrionalis (Hymenoptera : Vespidae, Epiponini)

Swarm-founding ‘Warrior wasps’ (Synoeca spp.) are found throughout the tropical regions of South America, are much feared due to their aggressive nest defence and painful sting. There are only five species of Synoeca, all construct distinctive nests that consist of a single sessile comb built onto the surface of a tree or rock face, which is covered by a ribbed envelope. Although locally common, research into this group is just starting. We studied eight colonies of Synoeca septentrionalis, a species recently been described from Brazil. A new colony is established by a swarm of 52 to 140 adults that constructs a colony containing around 200 brood cells. The largest colony collected containing 865 adults and over 1400 cells. The number of queen’s present among the eight colonies varied between 3 and 58 and no clear association between colony development and queen number was detected. Workers and queens were morphologically indistinguishable, but differences in their cuticular hydrocarbons were detected, particularly in their (Z)-9-alkenes. The simple cuticular profile, multiple queens, large size and small number of species makes the ‘Warrior wasps’ an excellent model group for further chemical ecology studies of swarm-founding wasps

Control of Pyrethroid-Resistant Chagas Disease Vectors with Entomopathogenic Fungi

Chagas disease, also known as American Trypanosomiasis, is the most relevant parasitic disease in Latin America, being a major burden that affects mostly poor human populations living in rural areas. The kissing-bugs of the Triatominae family transmit the parasite Trypanosoma cruzi by infectious blood-sucking; Triatoma infestans is the vector of major relevance in the southern Cone of South America. Current control strategies, heavily based on residual insecticide spraying, are threatened by the emergence of pyrethroid-resistant bug populations. Furthermore, ensuring the long-term and sustainable control of this overwhelming disease remains a major challenge. Here we show the utility of a simple, low-cost, biological control methodology against T. infestans bugs, regardless of their susceptibility to pyrethroid insecticides. It is based on the understanding of the initial contact interactions between a mycoinsecticide agent—the fungus Beauveria bassiana—and the host defense barrier, the bug cuticle. The proposed methodology is also supported by present data showing a relationship between the triatomine cuticle width and its hydrocarbon surface components, with insecticide resistance. These results will help to provide a safe and efficient alternative to overcome pyrethroid-resilience of these noxious bugs. A high transfer potential to immediate application in rural communities located in remote areas inaccessible to sanitary control teams, and to the control of other Chagas disease vectors as well, is also envisaged

Multiple Pathway-Based Genetic Variations Associated with Tobacco Related Multiple Primary Neoplasms

BACKGROUND: In order to elucidate a combination of genetic alterations that drive tobacco carcinogenesis we have explored a unique model system and analytical method for an unbiased qualitative and quantitative assessment of gene-gene and gene-environment interactions. The objective of this case control study was to assess genetic predisposition in a biologically enriched clinical model system of tobacco related cancers (TRC), occurring as Multiple Primary Neoplasms (MPN). METHODS: Genotyping of 21 candidate Single Nucleotide Polymorphisms (SNP) from major metabolic pathways was performed in a cohort of 151 MPN cases and 210 cancer-free controls. Statistical analysis using logistic regression and Multifactor Dimensionality Reduction (MDR) analysis was performed for studying higher order interactions among various SNPs and tobacco habit. RESULTS: Increased risk association was observed for patients with at least one TRC in the upper aero digestive tract (UADT) for variations in SULT1A1 Arg²¹³His, mEH Tyr¹¹³His, hOGG1 Ser³²⁶Cys, XRCC1 Arg²⁸⁰His and BRCA2 Asn³⁷²His. Gene-environment interactions were assessed using MDR analysis. The overall best model by MDR was tobacco habit/p53(Arg/Arg)/XRCC1(Arg³⁹⁹His)/mEH(Tyr¹¹³His) that had highest Cross Validation Consistency (8.3) and test accuracy (0.69). This model also showed significant association using logistic regression analysis. CONCLUSION: This is the first Indian study on a multipathway based approach to study genetic susceptibility to cancer in tobacco associated MPN. This approach could assist in planning additional studies for comprehensive understanding of tobacco carcinogenesis

Abstracts from the NIHR INVOLVE Conference 2017

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Prenatal exposures and exposomics of asthma

This review examines the causal investigation of preclinical development of childhood asthma using exposomic tools. We examine the current state of knowledge regarding early-life exposure to non-biogenic indoor air pollution and the developmental modulation of the immune system. We examine how metabolomics technologies could aid not only in the biomarker identification of a particular asthma phenotype, but also the mechanisms underlying the immunopathologic process. Within such a framework, we propose alternate components of exposomic investigation of asthma in which, the exposome represents a reiterative investigative process of targeted biomarker identification, validation through computational systems biology and physical sampling of environmental medi

Evolution of cuticular hydrocarbons in the hymenoptera : a meta-analysis

Chemical communication is the oldest form of communication, spreading across all organisms of life. In insects, cuticular hydrocarbons (CHC) function as the chemical recognition cues for the recognition of mates, species and nest-mates in social insects. Although much is known about the function of individual hydrocarbons and their biosynthesis, a phylogenetic overview is lacking. Here we review the CHC profiles of 241 species of hymenoptera, one of the largest and important insect orders, including the Symphyta (sawflies), the polyphyletic Parasitica (parasitoid wasps) and the Aculeata (wasps, bees and ants). We investigated whether these five major taxonomic groups differed in the presence and absence of CHC classes and whether the sociality of a species (solitarily vs. social) had an effect on CHC profile complexity. We found that the main CHC classes (i.e., n-alkanes, alkenes and methylalkanes) were all present early in the evolutionary history of the hymenoptera, as evidenced by their presence in ancient Symphyta and primitive Parasitica wasps. Throughout all groups within the Hymenoptera the more complex a CHC the fewer species that produce it, which may reflect the Occam's razor principle that insects’ only biosynthesize the most simple compound that fulfil its needs. Surprisingly there was no difference in the complexity of CHC profiles between social and solitary species, with some of the most complex CHC profiles belonging to the Parasitica. This profile complexity has been maintained in the ants, but some specialisation in biosynthetic pathways has led to a simplification of profiles in the aculeate wasps and bees. The absence of CHC classes in some taxa or species may be due to gene silencing or down-regulation rather than gene loss, as evidenced by sister species having highly divergent CHC profiles, and cannot be predicted by their phylogenetic history. The presence of highly complex CHC profiles prior to the vast radiation of the social hymenoptera indicates a 'spring-loaded' system where the diverse CHC needed for the complex communication systems of social insects, were already present for natural selection to act upon rather than evolve independently. This would greatly aid the multiple evolution of sociality in the Aculeata