scholarly journals Convergence in light transmission properties of transparent wing areas in clearwing mimetic butterflies

2020 ◽  
Author(s):  
Charline Pinna ◽  
Maëlle Vilbert ◽  
Stephan Borensztajn ◽  
Willy Daney de Marcillac ◽  
Florence Piron-Prunier ◽  
...  
Keyword(s):  
Optical Properties ◽  
Evolutionary Biology ◽  
Light Transmission ◽  
Interspecific Interaction ◽  
Fine Tuning ◽  
Colour Pattern ◽  
Wing Membrane ◽  
Microscopy Imaging ◽  
Transmission Properties ◽  
Aposematic Signals

AbstractMüllerian mimicry is a positive interspecific interaction, whereby co-occurring defended prey species share a common aposematic signal that advertises their defences to predators. In Lepidoptera, aposematic species typically harbour conspicuous opaque wing colour pattern, which have convergent optical properties, as perceived by predators. Surprisingly, some aposematic mimetic species have partially or totally transparent wings, which raises the question of whether optical properties of such transparent areas are also under selection for convergence. To answer this question and to investigate how transparency is achieved in the first place, we conducted a comparative study of optics and structures of transparent wings in neotropical mimetic clearwing Lepidoptera. We quantified transparency by spectrophotometry and characterised clearwing microstructures and nanostructures by microscopy imaging. We show that transparency is convergent among co-mimics in the eyes of predators, despite a large diversity of underlying micro- and nanostructures. Notably, we reveal that nanostructure density largely influences light transmission. While transparency is primarily produced by modification of microstructure features, nanostructures may provide a way to fine-tune the degree of transparency. This study calls for a change of paradigm in transparent mimetic lepidoptera: transparency not only enables camouflage but can also be part of aposematic signals.SignificanceTransparency in animals has long been associated to camouflage, but the existence of aposematic mimetic Lepidoptera with partly transparent wings raises the question of the role of transparency in aposematism. Here, we undertake the first comparative analysis of transparency features in mimetic Lepidoptera. We show that transparency is likely part of the aposematic signal, as light transmission properties are convergent among co-mimics. We also reveal a high diversity of wing structures (scales and wing membrane nanostructures) underlying transparency, which enables fine-tuning the degree of transparency. This study, at the interface between physical optics and evolutionary biology, sheds light on the evolution of transparency in aposematic mimetic lineages and may promote bioinspired applications for transparent materials such as antireflective devices.

scholarly journals Mimicry can drive convergence in structural and light transmission features of transparent wings in Lepidoptera

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Charline Sophie Pinna ◽  
Maëlle Vilbert ◽  
Stephan Borensztajn ◽  
Willy Daney de Marcillac ◽  
Florence Piron-Prunier ◽  
...  
Keyword(s):  
Optical Properties ◽  
Prey Species ◽  
Light Transmission ◽  
Structural Diversity ◽  
Interspecific Interaction ◽  
Fine Tuning ◽  
Microscopy Imaging ◽  
Wing Colour ◽  
Aposematic Signals ◽  
Colour Patterns

Müllerian mimicry is a positive interspecific interaction, whereby co-occurring defended prey species share a common aposematic signal. In Lepidoptera, aposematic species typically harbour conspicuous opaque wing colour patterns with convergent optical properties among co-mimetic species. Surprisingly, some aposematic mimetic species have partially transparent wings, raising the questions of whether optical properties of transparent patches are also convergent, and of how transparency is achieved. Here, we conducted a comparative study of wing optics, micro and nanostructures in neotropical mimetic clearwing Lepidoptera, using spectrophotometry and microscopy imaging. We show that transparency, as perceived by predators, is convergent among co-mimics in some mimicry rings. Underlying micro- and nanostructures are also sometimes convergent despite a large structural diversity. We reveal that while transparency is primarily produced by microstructure modifications, nanostructures largely influence light transmission, potentially enabling additional fine-tuning in transmission properties. This study shows that transparency might not only enable camouflage but can also be part of aposematic signals.

It Keeps Me Seeking

2018 ◽  
Author(s):  
Andrew Briggs ◽  
Hans Halvorson ◽  
Andrew Steane
Keyword(s):  
Evolutionary Biology ◽  
Quantum Physics ◽  
Natural World ◽  
Theological Reflection ◽  
Fine Tuning ◽  
Good Argument ◽  
The Difference ◽  
Argument From Design ◽  
Relationship Of

Two scientists and a philosopher aim to show how science both enriches and is enriched by Christian faith. The text is written around four themes: 1. God is a being to be known, not a hypothesis to be tested; 2. We set a high bar on what constitutes good argument; 3. Uncertainty is OK; 4. We are allowed to open up the window that the natural world offers us. This is not a work of apologetics. Rather, the text takes an overview of various themes and gives reactions and responses, intended to place science correctly as a valued component of the life of faith. The difference between philosophical analysis and theological reflection is expounded. Questions of human identity are addressed from philosophy, computer science, quantum physics, evolutionary biology and theological reflection. Contemporary physics reveals the subtle and open nature of physical existence, and offers lessons in how to learn and how to live with incomplete knowledge. The nature and role of miracles is considered. The ‘argument from design’ is critiqued, especially arguments from fine-tuning. Logical derivation from impersonal facts is not an appropriate route to a relationship of mutual trust. Mainstream evolutionary biology is assessed to be a valuable component of our understanding, but no exploratory process can itself fully account for the nature of what is discovered. To engage deeply in science is to seek truth and to seek a better future; it is also an activity of appreciation, as one may appreciate a work of art.

scholarly journals Temperature Dependence of Stress and Optical Properties in AlN Films Grown by MOCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 698
Author(s):  
Wenwang Wei ◽  
Yi Peng ◽  
Jiabin Wang ◽  
Muhammad Farooq Saleem ◽  
Wen Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Compressive Stress ◽  
Sapphire Substrate ◽  
Light Transmission ◽  
Chemical Vapor ◽  
Biaxial Stress ◽  
X Ray Diffraction ◽  
Patterned Sapphire Substrate ◽  
Transmission Electron ◽  
Nano Patterning

AlN epilayers were grown on a 2-inch [0001] conventional flat sapphire substrate (CSS) and a nano-patterned sapphire substrate (NPSS) by metalorganic chemical vapor deposition. In this work, the effect of the substrate template and temperature on stress and optical properties of AlN films has been studied by using Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible spectrophotometer and spectroscopic ellipsometry (SE). The AlN on NPSS exhibits lower compressive stress and strain values. The biaxial stress decreases from 1.59 to 0.60 GPa for AlN on CSS and from 0.90 to 0.38 GPa for AlN on NPSS sample in the temperature range 80–300 K, which shows compressive stress. According to the TEM data, the stress varies from tensile on the interface to compressive on the surface. It can be deduced that the nano-holes provide more channels for stress relaxation. Nano-patterning leads to a lower degree of disorder and stress/strain relaxes by the formation of the nano-hole structure between the interface of AlN epilayers and the substrate. The low crystal disorder and defects in the AlN on NPSS is confirmed by the small Urbach energy values. The variation in bandgap (Eg) and optical constants (n, k) with temperature are discussed in detail. Nano-patterning leads to poor light transmission due to light scattering, coupling, and trapping in nano-holes.

Fine-tuning the optical properties of aluminium and lithium quinolates through oligothiophene substituents in 2-position

2004 ◽  
Vol 147 (1-3) ◽  
pp. 175-182 ◽  
Author(s):  
A. Jaafari ◽  
V. Ouzeau ◽  
M. Ely ◽  
F. Rodriguez ◽  
A. Yassar ◽  
...  
Keyword(s):  
Optical Properties ◽  
Fine Tuning

pH-Mediated fine-tuning of optical properties of graphene oxide membranes

Carbon ◽  
2012 ◽  
Vol 50 (9) ◽  
pp. 3233-3239 ◽  
Author(s):  
Wei Lv ◽  
Cong-Hui You ◽  
Sida Wu ◽  
Baohua Li ◽  
Zhen-Ping Zhu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Fine Tuning ◽  
Oxide Membranes ◽  
Graphene Oxide Membranes

scholarly journals Fine Tuning the Optical Properties of Green to Red Photoconvertible Fluorescent Proteins

2010 ◽  
Vol 98 (3) ◽  
pp. 413a
Author(s):  
Karin Nienhaus ◽  
Virgile Adam ◽  
Dominique Bourgeois ◽  
G. Ulrich Nienhaus
Keyword(s):  
Optical Properties ◽  
Fluorescent Proteins ◽  
Fine Tuning

scholarly journals Stabilizing selection on individual pattern elements of aposematic signals

2017 ◽  
Vol 284 (1861) ◽  
pp. 20170926 ◽  
Author(s):  
Anne E. Winters ◽  
Naomi F. Green ◽  
Nerida G. Wilson ◽  
Martin J. How ◽  
Mary J. Garson ◽  
...  
Keyword(s):  
Pattern Analysis ◽  
Marine Organism ◽  
Warning Signal ◽  
Colour Pattern ◽  
Stabilizing Selection ◽  
Warning Signals ◽  
Fish Predator ◽  
Selection For ◽  
Aposematic Signals ◽  
Behavioural Experiments

Warning signal variation is ubiquitous but paradoxical: low variability should aid recognition and learning by predators. However, spatial variability in the direction and strength of selection for individual elements of the warning signal may allow phenotypic variation for some components, but not others. Variation in selection may occur if predators only learn particular colour pattern components rather than the entire signal. Here, we used a nudibranch mollusc, Goniobranchus splendidus , which exhibits a conspicuous red spot/white body/yellow rim colour pattern, to test this hypothesis. We first demonstrated that secondary metabolites stored within the nudibranch were unpalatable to a marine organism. Using pattern analysis, we demonstrated that the yellow rim remained invariable within and between populations; however, red spots varied significantly in both colour and pattern. In behavioural experiments, a potential fish predator, Rhinecanthus aculeatus , used the presence of the yellow rims to recognize and avoid warning signals. Yellow rims remained stable in the presence of high genetic divergence among populations. We therefore suggest that how predators learn warning signals may cause stabilizing selection on individual colour pattern elements, and will thus have important implications on the evolution of warning signals.

scholarly journals Partial and Total Substitution of Zn by Mg in the Cu2ZnSnS4 Structure

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 578
Author(s):  
Diana M. Mena Romero ◽  
David Victoria Valenzuela ◽  
Cristy L. Azanza Ricardo
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Cost Effective ◽  
Energy Conversion Efficiency ◽  
Band Gap Energy ◽  
Fine Tuning ◽  
Secondary Phases ◽  
Solar Absorber ◽  
High Efficient ◽  
Earth Abundant

Cu 2 ZnSnS 4 (CZTS) is a quaternary semiconductor that has emerged as a promising component in solar absorber materials due to its excellent optical properties such as band-gap energy of ca. 1.5 eV and significant absorption coefficient in the order of 10 4 cm − 1 . Nevertheless, the energy conversion efficiency of CZTS-based devices has not reached the theoretical limits yet, possibly due to the existence of antisite defects (such as Cu Zn or Zn Cu ) and secondary phases. Based on electronic similarities with Zn, Mg has been proposed for Zn substitution in the CZTS structure in the design of alternative semiconductors for thin-film solar cell applications. This work aims to study the properties of the CZTS having Mg incorporated in the structure replacing Zn, with the following stoichiometry: x = 0, 0.25, 0.5, 0.75, and 1 in the formula Cu 2 Zn 1 − x Mg x SnS 4 (CZ-MTS). The semiconductor was prepared by the hot injection method, using oleylamine (OLA) as both surfactant and solvent. The presence and concentration of incorporated Mg allowed the fine-tuning of the CZ-MTS semiconductor’s structural and optical properties. Furthermore, it was observed that the inclusion of Mg in the CZTS structure leads to a better embodiment ratio of the Zn during the synthesis, thus reducing the excess of starting precursors. In summary, CZ-MTS is a promising candidate to fabricate high efficient and cost-effective thin-film solar cells made of earth-abundant elements.

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