scholarly journals Lens transmittance shapes ultraviolet sensitivity in the eyes of frogs from diverse ecological and phylogenetic backgrounds

2020 ◽  
Vol 287 (1918) ◽  
pp. 20192253 ◽  
Author(s):  
Carola A. M. Yovanovich ◽  
Michele E. R. Pierotti ◽  
Almut Kelber ◽  
Gabriel Jorgewich-Cohen ◽  
Roberto Ibáñez ◽  
...  
Keyword(s):  
Uv Light ◽  
Visible Spectrum ◽  
Diel Activity ◽  
Closely Related Species ◽  
Eye Size ◽  
Diel Activity Pattern ◽  
Ocular Media ◽  
Uv Transmittance ◽  
The Relationship ◽  
Lens Transmittance

The amount of short wavelength (ultraviolet (UV), violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographical distributions and phylogenetic positions and used them together with eye size and pupil shape to evaluate the relationship with diel activity pattern, elevation and latitude. We found an unusually high lens UV transmittance in the most basal species, and a cut-off range that extends into the visible spectrum for the rest of the sample, with lenses even absorbing violet light in some diurnal species. However, other diurnal frogs had lenses that transmit UV light like the nocturnal species. This unclear pattern in the segregation of ocular media transmittance and diel activity is shared with other vertebrates and is consistent with the absence of significant correlations in our statistical analyses. Although we did not detect a significant phylogenetic effect, closely related species tend to have similar transmittances, irrespective of whether they share the same diel pattern or not, suggesting that anuran ocular media transmittance properties might be related to phylogeny.

scholarly journals Lens Transmittance Shapes UV Sensitivity in the Eyes of Frogs from Diverse Ecological and Phylogenetic Backgrounds

2019 ◽  
Author(s):  
Carola A. M. Yovanovich ◽  
Michele E. R. Pierotti ◽  
Almut Kelber ◽  
Gabriel Jorgewich-Cohen ◽  
Roberto Ibáñez ◽  
...  
Keyword(s):  
Uv Light ◽  
Visible Spectrum ◽  
Diel Activity ◽  
Closely Related Species ◽  
Eye Size ◽  
Diel Activity Pattern ◽  
Ocular Media ◽  
Uv Transmittance ◽  
The Relationship ◽  
Lens Transmittance

ABSTRACTThe amount of short wavelength (UV, violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographic distributions, and phylogenetic positions and used them together with eye size and pupil shape to evaluate the relationship with diel activity pattern, elevation and latitude. We found an unusually high lens UV transmittance in the most basal species, and a range that extends into the visible spectrum for the rest of the sample, with lenses even absorbing violet light in some diurnal species. However, other diurnal frogs had lenses that transmit UV light like the nocturnal species. This unclear pattern in the segregation of ocular media transmittance and diel activity is shared with other vertebrates and is consistent with the absence of significant correlations in our statistical analyses. Although we did not detect a significant phylogenetic effect, closely related species tend to have similar transmittances, irrespective of whether they share the same diel pattern or not, suggesting that ocular media transmittance properties might be related to phylogeny.

scholarly journals Ultraviolet vision in birds: the importance of transparent eye media

2014 ◽  
Vol 281 (1774) ◽  
pp. 20132209 ◽  
Author(s):  
Olle Lind ◽  
Mindaugas Mitkus ◽  
Peter Olsson ◽  
Almut Kelber
Keyword(s):  
Uv Light ◽  
Bird Species ◽  
Bright Light ◽  
Visual Pigments ◽  
Colour Discrimination ◽  
Animal Kingdom ◽  
Eye Size ◽  
Visual Models ◽  
Ultraviolet Vision ◽  
Ocular Media

Ultraviolet (UV)-sensitive visual pigments are widespread in the animal kingdom but many animals, for example primates, block UV light from reaching their retina by pigmented lenses. Birds have UV-sensitive (UVS) visual pigments with sensitivity maxima around 360–373 nm (UVS) or 402–426 nm (violet-sensitive, VS). We describe how these pigments are matched by the ocular media transmittance in 38 bird species. Birds with UVS pigments have ocular media that transmit more UV light (wavelength of 50% transmittance, λ T0.5 , 323 nm) than birds with VS pigments ( λ T0.5 , 358 nm). Yet, visual models predict that colour discrimination in bright light is mostly dependent on the visual pigment (UVS or VS) and little on the ocular media. We hypothesize that the precise spectral tuning of the ocular media is mostly relevant for detecting weak UV signals, e.g. in dim hollow-nests of passerines and parrots. The correlation between eye size and UV transparency of the ocular media suggests little or no lens pigmentation. Therefore, only small birds gain the full advantage from shifting pigment sensitivity from VS to UVS. On the other hand, some birds with VS pigments have unexpectedly low UV transmission of the ocular media, probably because of UV blocking lens pigmentation.

Synthesis and Application of New Benzotriazole Derivatives as UV Absorbers for Polyester Fabrics

2011 ◽  
Vol 233-235 ◽  
pp. 219-224 ◽  
Author(s):  
Yan Yan Yang ◽  
Hong Qi Li ◽  
Xue Dan He ◽  
Bing Nan Mu ◽  
Yi Jun Chen ◽  
...  
Keyword(s):  
Uv Light ◽  
Protection Factor ◽  
Polyester Fabrics ◽  
Ultraviolet Protection Factor ◽  
Uv Absorbers ◽  
Ultraviolet Protection ◽  
Dyeing Method ◽  
Uv Transmittance ◽  
The Relationship ◽  
Benzotriazole Derivatives

2-(2′-Hydroxyphenyl)-5-amino-2H-benzotriazole was synthesized and subjected to acylamidation to yield three new ultraviolet (UV) absorbers. The largest absorption wavelength and the relationship between the concentration and the maximum absorbance of the UV absorbers were measured in dimethylsulfoxide. Then the four benzotriazole type UV absorbers were dispersed and applied onto polyester fabrics with the high temperature and pressure dyeing method. The stabilizing effect against UV light of the finished fabrics was studied by ultraviolet protection factor (UPF) and UV transmittance measurement.

scholarly journals Lens and cornea limit UV vision of birds – a phylogenetic perspective

2021 ◽  
Author(s):  
Peter Olsson ◽  
Olle Lind ◽  
Mindaugas Mitkus ◽  
Kaspar Delhey ◽  
Almut Kelber
Keyword(s):  
Uv Light ◽  
Strong Predictor ◽  
Chromatic Aberration ◽  
Limiting Factor ◽  
Ancestral State ◽  
Eye Size ◽  
Phylogenetic Perspective ◽  
Uv Vision ◽  
Ocular Media ◽  
Specific Contribution

Most vertebrates have UV-sensitive vision, but the UV-sensitivity of their eyes is limited by the transmittance of the ocular media, and the specific contribution of the different media (cornea, lens) has remained unclear. Here we describe the transmittance of all ocular media (OMT), as well as that of lenses and corneas of birds. For 66 species belonging to 18 orders, the wavelength at which 50% of light is transmitted through the ocular media to the retina (λT0.5) ranges from 310 to 398 nm. Low λT0.5 corresponds to more UV-light transmitted. Corneal λT0.5 varies only between 300 and 345 nm, whereas lens λT0.5 values are more variable (between 315 and 400 nm) and tend to be the limiting factor, determining OMT in the majority of species. OMT λT0.5 is positively correlated with eye size, but λT0.5 of corneas and lenses are not correlated with their thickness when controlled for phylogeny. Corneal and lens transmittances do not differ between birds with UV- and violet-sensitive SWS1 opsin when controlling for eye size and phylogeny. Phylogenetic relatedness is a strong predictor of OMT, and ancestral state reconstructions suggest that from ancestral intermediate OMT, highly UV-transparent ocular media (low λT0.5) evolved at least five times in our sample of birds. Some birds have evolved in the opposite direction towards a more UV-opaque lens, possibly due to pigmentation, likely to mitigate UV-damage or reduce chromatic aberration.

scholarly journals Nocturnal and diurnal activity of armored suckermouth catfish (Loricariidae: Pterygoplichthys) associated with wintering Florida manatees (Trichechus manatus latirostris)

2010 ◽  
Vol 8 (4) ◽  
pp. 893-898 ◽  
Author(s):  
Leo G. Nico
Keyword(s):  
River Basin ◽  
Activity Pattern ◽  
Diel Activity ◽  
Diurnal Activity ◽  
Trichechus Manatus ◽  
Trichechus Manatus Latirostris ◽  
Size Classes ◽  
Diel Activity Pattern ◽  
Spring System ◽  
Diel Period

Several Pterygoplichthys species, members of the Neotropical catfish family Loricariidae, have been widely introduced outside their native ranges. In this paper, I present observations on the diel activity pattern of non-native Pterygoplichthys, tentatively identified as P. disjunctivus, with respect to their attachment and grazing on endangered Florida manatees, Trichechus manatus latirostris. The study was conducted in December 2009 at Volusia Blue Spring, an artesianal spring system in the St. Johns River basin, Florida (USA). Supplemented by information gathered during previous visits to the spring site, this study revealed that adult Pterygoplichthys are active throughout the diel period (day, twilight and night). However, juvenile Pterygoplichthys were largely nocturnal and only at night did they consistently join adults in attaching to manatees. The juveniles generally remain hidden during the day, probably responding to presence of diurnal predators, mainly birds. Differences in diel behaviors among different Pterygoplichthys size classes in Florida are consistent with published observations on loricariids inhabiting clearwater streams within their native ranges.

The Relationship Between UV Transmittance and Color — Visual Description and Instrumental Measurement

2008 ◽  
Vol 78 (2) ◽  
pp. 128-137 ◽  
Author(s):  
C.A. Wilson ◽  
P.H. Gies ◽  
B.E. Niven ◽  
A. McLennan ◽  
N.K. Bevin
Keyword(s):  
Instrumental Measurement ◽  
Uv Transmittance ◽  
Visual Description ◽  
The Relationship

scholarly journals Non-uniform evolutionary response of gecko eye size to changes in diel activity patterns

2018 ◽  
Vol 14 (5) ◽  
pp. 20180064 ◽  
Author(s):  
Lars Schmitz ◽  
Timothy E. Higham
Keyword(s):  
Phenotypic Diversity ◽  
Activity Patterns ◽  
Model Fitting ◽  
Regime Shifts ◽  
Least Square ◽  
Diel Activity ◽  
Relevant Variable ◽  
Eye Size ◽  
Evolutionary Response ◽  
Diel Activity Patterns

Geckos feature a large range of eye sizes, but what drives this phenotypic diversity is currently unknown. Earlier studies point towards diel activity patterns (DAPs) and locomotory mode, but phylogenetic comparative studies in support of the proposed adaptive mode of eye evolution are lacking. Here, we test the hypothesis of DAPs as the driver of eye size evolution with a dataset on 99 species of gecko. Results from phylogenetic generalized least-square analysis (PGLS) and multivariate model-fitting reveal smaller eyes in diurnal geckos consistent with different phenotypic optima. However, Bayesian analyses of selective regime shifts demonstrate that only two of nine transitions from nocturnal to diurnal activity are coupled with decreases in eye size, and two other regime shifts are not associated with DAP transitions. This non-uniform evolutionary response suggests that eye size is not the only functionally relevant variable. Evolutionary adaptations may therefore include different combinations of several traits (e.g. photoreceptors), all with the same functional outcome. Our results further demonstrate that DAP only partially explains eye size diversity in geckos. As open habitats favour the evolution of large eyes while obstructed habitats favour small eyes, the degree of habitat clutter emerges as another potential axis of eye diversification.

Evaluation of Reflectance Fluorodensitometry for Measuring Aflatoxins on Thin Layer Plates

1971 ◽  
Vol 54 (4) ◽  
pp. 870-873
Author(s):  
Walter A Pons
Keyword(s):  
Thin Layer ◽  
Silica Gel ◽  
Uv Light ◽  
Plate Surface ◽  
Coefficients Of Variation ◽  
Standard Application ◽  
Tlc Plates ◽  
Relationship Of ◽  
The Relationship

Abstract A reflectance fluorodensitometer employing illumination of chromatograms with longwave UV light at 45° angles to the plate surface and measurement of reflected fluorescence at 90° was found to be suitable for measuring aflatoxins on silica gel-coated thin layer plates. The relationship of peak area vs. concentration was linear for 1–20 ng aflatoxins B1 and G1/ spot. Degradation of aflatoxins was slight. Five repetitive scans of the same chromatogram containing 5 ng each of B1 and G1 reduced the recorded areas an average of 1% per scan. Consecutive scans of 8 identical standard chromatograms containing 5 ng each of B1 and G1 and 1.5 ng each of B2 and G2 showed a reproducibility, as measured by coefficients of variation, of ±4–5% (B1 and G1) and ±5–9% (B2 and G2), representing the combined errors of standard application, TLC development, and scanning. Analysis of aflatoxins in purified sample extracts from 6 contaminated oilseed meals, 3–500 μg afla toxins/kg, in which the same TLC plates were scanned by a transmission densitometer and the reflectance densitometer yielded essentially equivalent values.

scholarly journals Convergent evolution of bird-mammal shared characteristics for adapting to nocturnality

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182185 ◽  
Author(s):  
Yonghua Wu ◽  
Haifeng Wang
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Convergent Evolution ◽  
Ecological Model ◽  
Common Factor ◽  
Ecological Factors ◽  
Adaptive Strategy ◽  
Diel Activity ◽  
Diel Activity Pattern ◽  
Low Ambient Temperature

The diapsid lineage (birds) and synapsid lineage (mammals), share a suite of functionally similar characteristics (e.g. endothermy) that are considered to be a result of their convergent evolution, but the candidate selections leading to this convergent evolution are still under debate. Here, we used a newly developed molecular phyloecological approach to reconstruct the diel activity pattern of the common ancestors of living birds. Our results strongly suggest that they had adaptations to nocturnality during their early evolution, which is remarkably similar to that of ancestral mammals. Given their similar adaptation to nocturnality, we propose that the shared traits in birds and mammals may have partly evolved as a result of the convergent evolution of their early ancestors adapting to ecological factors (e.g. low ambient temperature) associated with nocturnality. Finally, a conceptually unifying ecological model on the evolution of endothermy in diverse organisms with an emphasis on low ambient temperature is proposed. We reason that endothermy may evolve as an adaptive strategy to enable organisms to effectively implement various life-cycle activities under relatively low-temperature environments. In particular, a habitat shift from high-temperature to relatively low-temperature environments is identified as a common factor underlying the evolution of endothermy.

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