The formation of elaborate molecules is regarded as an essential first step in prebiotic chemistry, but how such transformations could spontaneously occur, particularly in dilute aqueous conditions, remains poorly understood. Here, micromolar concentrations of a 3,4-dialkylpyrrole and excess formaldehyde in aqueous micellar solution (pH 7) at 25 or 50 °C were found to give good yield (up to 40%) of the lipophilic octaalkylporphyrin. The reaction occurs despite a mean occupancy number of ∼0.1 pyrrole molecules/micelle, and <1 of 10,000 micelles initially containing the requisite 4 pyrrole molecules to form the porphyrin assuming a (random) Poisson distribution. Yields of up to 13% were observed in large, unilamellar phosphatidylcholine vesicles, wherein there are ∼15,000 pyrrole molecules per vesicle membrane. Double-labeling crossover experiments (of 3,4-diethylpyrrole and 3,4-dimethylpyrrole) examined by mass spectrometry revealed facile exchange processes of reactive constituents among both micelle and vesicle surfactant assemblies. Together, the exchange of pyrrolic reactants among micelles and the thermodynamic driving force for tetrapyrrole formation overcome the apparent statistical odds against reaction. The fruitful exchange, accumulation and reaction of minute quantities of reactants in aqueous-surfactant assemblies suggest a general means for formation of prebiotically valuable constituents, even when the statistical odds at the outset are overwhelmingly improbable.

The Asian tiger mosquito, Aedes albopictus, transmits several arboviruses of public health importance, including chikungunya and dengue. Since its introduction to the United States in 1985, the species has invaded more than 40 states, including temperate areas not previously at risk of Aedes-transmitted arboviruses. Mathematical models incorporate climatic variables in predictions of site-specific Ae. albopictus abundances to identify human populations at risk of disease. However, these models rely on coarse resolutions of environmental data that may not accurately represent the climatic profile experienced by mosquitoes in the field, particularly in climatically heterogeneous urban areas. In this study, we pair field surveys of larval and adult Ae. albopictus mosquitoes with site-specific microclimate data across a range of land use types to investigate the relationships between microclimate, density of larval habitat, and adult mosquito abundance and determine whether these relationships change across an urban gradient. We find no evidence for a difference in larval habitat density or adult abundance between rural, suburban, and urban land classes. Adult abundance increases with increasing larval habitat density, which itself is dependent on microclimate. Adult abundance is strongly explained by microclimate variables, demonstrating that theoretically derived, laboratory-parameterized relationships in ectotherm physiology apply to the field. Our results support the continued use of temperature-dependent models to predict Ae. albopictus abundance in urban areas.

word count (max 250): 216 17 Text word count: 3753 18 ABSTRACT 30The Asian tiger mosquito, Aedes albopictus, transmits several arboviruses of public 31 health importance, including chikungunya and Zika. Since its introduction to the United States in 32 1985, the species has invaded over forty states, including temperate areas not previously at risk 33 of Aedes-transmitted arboviruses. Mathematical models incorporate climatic variables in 34 predictions of site-specific Ae. albopictus abundances to identify human populations at risk of 35 disease. However, these models rely on coarse resolutions of environmental data that may not 36 accurately represent the climatic profile experienced by mosquitoes in the field, particularly in 37 climatically-heterogeneous urban areas. In this study, we pair field surveys of larval and adult 38Ae. albopictus mosquitoes with site-specific microclimate data across a range of land use types 39 to investigate the relationships between microclimate, density of larval habitat, and adult 40 mosquito abundance and determine whether these relationships change across an urban 41 gradient. We find no evidence for a difference in larval habitat density or adult abundance 42 between rural, suburban, and urban land classes. Adult abundance increases with increasing 43 larval habitat density, which itself is dependent on microclimate. Adult abundance is strongly 44 explained by microclimate variables, demonstrating that theoretically derived, lab-parameterized 45 relationships in ectotherm physiology apply to the field. Our results provide support for the 46 continued use of temperature-dependent models to predict Ae. albopictus abundance in urban 47 areas. 48 49 cooler climates than Ae. aegypti. Following initial establishment in Texas, Ae. albopictus has 56 invaded over 40 states, 7 and models predict its range will expand as the climate warms. 8,9 At 57 present, established populations of Ae. albopictus are found in the United States as far north as 58Connecticut and New York, 10,11 well outside the present range of Ae. aegypti. Ae. albopictus is 59 implicated in transmission cycles of dengue and chikungunya in the Mediterranean region of 60 Europe, 12,13 which suggests that temperate regions of the US may be similarly vulnerable. 61Given the potential role of Ae. albopictus in disease transmission, it is important to 62 understand what factors influence its abundance. Ae. albopictus is sensitive to variation in 63 temperature due to temperature-dependent life history traits such as development rates, 64 fecundity, and survival. [14][15][16] Climate or meteorological predictors are widely used in mechanistic 65 models and statistical models. [17][18][19][20][21][22] Models leverage these relationships to predict mosquito 66 presence, population growth rates, and abundances based on temperature metrics derived from 67 weather stations or remotely-sensed datasets. However, urban landscapes are composed of a 68 variety of land classes (e.g. residential, developed, vegetated), which vary in th...