Wing scale ultrastructure underlying convergent and divergent iridescent colours in mimetic Heliconius butterflies

Iridescence is an optical phenomenon whereby colour changes with the illumination and viewing angle. It can be produced by thin film interference or diffraction. Iridescent optical structures are fairly common in nature, but relatively little is known about their production or evolution. Here we describe the structures responsible for producing blue-green iridescent colour in Heliconius butterflies. Overall the wing scale structures of iridescent and non-iridescent Heliconius species are very similar, both having longitudinal ridges joined by cross-ribs. However, iridescent scales have ridges composed of layered lamellae, which act as multilayer reflectors. Differences in brightness between species can be explained by the extent of overlap of the lamellae and their curvature as well as the density of ridges on the scale. Heliconius are well known for their Müllerian mimicry. We find that iridescent structural colour is not closely matched between co-mimetic species. Differences appear less pronounced in models of Heliconius vision than models of avian vision, suggesting that they are not driven by selection to avoid heterospecific courtship by co-mimics. Ridge profiles appear to evolve relatively slowly, being similar between closely related taxa, while ridge density evolves faster and is similar between distantly related co-mimics

Prévention et traitement de l'insuffisance pondérale chez le jeune enfant du Mono (Bénin)

Background: This study aimed to assess the prevention and treatment effectiveness of underweight in less than two years old children admitted in 2001 to community nutrition programme of Mono area in Benin. Methods: A longitudinal retrospective survey took place in 30 villages chosen at random. It concerned a sample of 1799 children. Inside of those children, during the 2001 year, when they were admitted to the programme, 1545 were without underweight, have had more than one month following visit and about them the underweight effectiveness prevention had been analyzed; the others 111 were underweighted, have had more than one month following visit and about them the underweight treatment had been assessed. The 143 other children have been followed for only one month. The prevention effectiveness had been explored by the evolution of the cumulative incidence of underweight according to the number of following visit and the underweight incidence density. The treatment effectiveness has been analysed by calculating the recovery rate and incidence density. Results: During 2001, there have been observed 10% for the underweight cumulative incidence and 51.4% for the cumulative incidence of underweight recovery. The underweight and recovery incidence density were respectively 14 cases for 1000 persons-months of following and 118 cases for 1000 persons-months of following. The children with serious underweight at their last following visit have had the number of following visits lower than those who were with moderate underweight. The recovery was arrived after two to twelve months. There was a significant increase of underweight prevalence with the increase of following visit number inside the children with a normal weight at their admission into the programme. Conclusion: During the 2001 following, the underweight prevention and treatment activities of community nutrition workers have been little effectiveness. The low level of instruction of community nutrition workers, their low level of knowledge of essential community nutrition activities, their multiple tasks and the not used appropriate foods for the treatment of underweight are the possible causes of the poor performance observed. © 2007 Elsevier Masson SAS. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Preclinical characterization of an intravenous coronavirus 3CL protease inhibitor for the potential treatment of COVID19

COVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. PF-00835231, a 3CL protease inhibitor, has exhibited potent in vitro antiviral activity against SARS-CoV-2 as a single agent. Here we report, the design and characterization of a phosphate prodrug PF-07304814 to enable the delivery and projected sustained systemic exposure in human of PF-00835231 to inhibit coronavirus family 3CL protease activity with selectivity over human host protease targets. Furthermore, we show that PF-00835231 has additive/synergistic activity in combination with remdesivir. We present the ADME, safety, in vitro, and in vivo antiviral activity data that supports the clinical evaluation of PF-07304814 as a potential COVID-19 treatment. © 2021, The Author(s).Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]