DIPTEREX RESISTANCE IN THE HOUSEFLY AND THE SYNERGIC MECHANISM OF SV1 IN RELATION TO PENETRATION THROUGH CUTICLE

Abstract  SV₁ was observed to have obvious synergism and could delay housefly ( Musca domestica vicina ) resistance development to Dipterex. The penetration rates of Dipterex through housefly cuticle were determined in a susceptible and two resistant strains. The results indicated that the penetration in the resistant housefly strains was obviously slower than in the susceptible one. The penetrating rate of SV₁+ Dipterex (in mixture) was higher than that of Dipterex. The penetration reduction in resistant houseflies may be an important factor in bringing forth resistance. The increase of the penetrating rate of Dipterex and the decrease of its metabolic rate are regarded as the important mechanisms of SV₁ synergism to Dipterex.     

Biogeography of salt marsh plant zonation on the Pacific coast of South America

Aim

The aim of this study was to investigate the biogeography of plant zonation in salt marshes on the Pacific coast of South America; to examine whether salt marsh plant zonation varies with latitude; and to explore the relative importance of climatic, tidal, edaphic and disturbance factors in explaining large‐scale variation in salt marsh plant community structure.

Location

A 2,000‐km latitudinal gradient on the Pacific coast in Chile, with a climate shift from hyper‐arid at low to hyper‐humid at high latitudes.

Methods

Plant zonation was quantified in field surveys of ten marshes. Climate, tidal regimes, edaphic factors and disturbances (tsunami and rainfall floods) were determined. We used multivariate analyses to explore their relative importance in explaining large‐scale variation in salt marsh plant community structure.

Results

Across latitude, marshes were dominated by distinct plant communities in different climate regions, especially at the extreme dry and wet latitudes. Intertidal plant species zonation was present in hyper‐arid and semi‐arid climates, but not in arid, humid and hyper‐humid climates. Latitudinal variation in low‐marsh plant communities (regularly flooded at high tide) was largely a function of precipitation, while at high marshes (never flooded at high tide) latitudinal variation was explained with precipitation, temperature, tidal cycles, soil salinity and disturbances.

Main conclusions

Salt marshes on the Pacific coast of South America belong to Dry Coast and Temperate biogeographic types. Salt marsh plant zonation varies across latitude, and is explained by climatic, tidal, edaphic and disturbance factors. These patterns appear to be mechanistically explained by extrapolating experimentally generated community assembly models and have implications for predicting responses to climate change.     

Molecular modelling of ionic liquids in the ordered mesoporous carbon CMK-5

We performed classical molecular dynamics simulations of the ionic liquids (ILs) [dmim⁺][Cl^?] and [emim⁺][NTf₂^?], confined in a model CMK-5 material, which consists of amorphous carbon nanopipes (ACNPs) arranged in a hexagonal array. We compare our findings against the behaviour of the same ILs inside an isolated ACNP (i.e. no IL adsorbed on the outer surface of the ACNP) and inside a model CMK-3 material (which is similar to CMK-5, but is formed by amorphous carbon nanorods). Our results indicate that the presence of IL adsorbed in the outer surface of an uncharged ACNP in CMK-5 affects the dynamics and the density of an IL adsorbed inside the ACNP and vice versa. ILs adsorbed outside the nanopipes in CMK-5 (i.e. with IL also adsorbed inside the nanopipes) have faster dynamics and remain closer to the carbon surfaces when compared to the same ILs adsorbed on CMK-3 materials. The trends are IL-specific: [dmim⁺][Cl^?] has slower dynamics when inside an isolated ACNP than when inside the ACNPs in CMK-5, but in contrast, [emim⁺][NTf₂^?] moves faster when it is inside an isolated ACNP than when it is inside the ACNPs in CMK-5 (i.e. with IL adsorbed outside the nanopipes).