Ultraviolet reflecting photonic microstructures in the King Penguin beak

King and emperor penguins ( Aptenodytes patagonicus and Aptenodytes forsteri ) are the only species of marine birds so far known to reflect ultraviolet (UV) light from their beaks. Unlike humans, most birds perceive UV light and several species communicate using the near UV spectrum. Indeed, UV reflectance in addition to the colour of songbird feathers has been recognized as an important signal when choosing a mate. The king penguin is endowed with several highly coloured ornaments, notably its beak horn and breast and auricular plumage, but only its beak reflects UV, a property considered to influence its sexual attraction. Because no avian UV-reflecting pigments have yet been identified, the origin of such reflections is probably structural. In an attempt to identify the structures that give rise to UV reflectance, we combined reflectance spectrophotometry and morphological analysis by both light and electron microscopy, after experimental removal of surface layers of the beak horn. Here, we characterize for the first time a multilayer reflector photonic microstructure that produces the UV reflections in the king penguin beak.

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The Detection of Near-Ultraviolet Light by Nonmigratory and Migratory Birds

The Auk ◽

10.1093/auk/101.1.53 ◽

1984 ◽

Vol 101 (1) ◽

pp. 53-58 ◽

Cited By ~ 18

Author(s):

John W. Parrish ◽

James A. Ptacek ◽

Kevin L. Will

Keyword(s):

Migratory Birds ◽

Uv Light ◽

Mate Recognition ◽

Insectivorous Birds ◽

Uv Spectrum ◽

Near Ultraviolet ◽

Ultraviolet Reflectance ◽

Uv Reflectance ◽

Uv Vision ◽

First Time

Abstract Near-ultraviolet (UV) light reception was demonstrated for the first time in three species of nonmigratory emberizid and passerid birds. Behavioral data also established that eight additional alcedinid and emberizid birds can detect near-UV wavelengths. The finding that these more recently evolved species can see near-UV light implies that near-UV vision is probably an important visual capability in most, if not all, diurnal birds. Although the utility of near-UV reception for birds remains equivocal, the fact that nonmigratory as well as migratory birds can perceive UV suggests that birds may be able to utilize the UV spectrum for homing, orientation, and navigation, as do the UV-sensitive arthropods. It also can be inferred that UV vision may be especially useful to insectivorous birds for the detection of UV reflectance patterns, which many otherwise cryptic arthropods possess for mate recognition. Ultraviolet reflectance patterns also may be useful to frugivorous and nectarivorous birds for the detection of food items.

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4 Pattern Recognition for Healing Burns to Compute Evidence: Space Syntax and Machine Learning Analysis of Burns Center Karachi

Sir Syed Research Journal of Engineering & Technology ◽

10.33317/ssurj.v1i1.64 ◽

2013 ◽

Vol 1 (1) ◽

pp. 13

Author(s):

Javaria Manzoor Shaikh ◽

JaeSeung Park

Keyword(s):

Pattern Recognition ◽

Prediction Models ◽

Uv Light ◽

Healing Process ◽

Space Syntax ◽

Depth Map ◽

Routine Tasks ◽

Hyper Plane ◽

First Time ◽

Learning Analysis

Usually elongated hospitalization is experienced byBurn patients, and the precise forecast of the placement of patientaccording to the healing acceleration has significant consequenceon healthcare supply administration. Substantial amount ofevidence suggest that sun light is essential to burns healing andcould be exceptionally beneficial for burned patients andworkforce in healthcare building. Satisfactory UV sunlight isfundamental for a calculated amount of burn to heal; this delicaterather complex matrix is achieved by applying patternclassification for the first time on the space syntax map of the floorplan and Browder chart of the burned patient. On the basis of thedata determined from this specific healthcare learning technique,nurse can decide the location of the patient on the floor plan, hencepatient safety first is the priority in the routine tasks by staff inhealthcare settings. Whereas insufficient UV light and vitamin Dcan retard healing process, hence this experiment focuses onmachine learning design in which pattern recognition andtechnology supports patient safety as our primary goal. In thisexperiment we lowered the adverse events from 2012- 2013, andnearly missed errors and prevented medical deaths up to 50%lower, as compared to the data of 2005- 2012 before this techniquewas incorporated.In this research paper, three distinctive phases of clinicalsituations are considered—primarily: admission, secondly: acute,and tertiary: post-treatment according to the burn pattern andhealing rate—and be validated by capable AI- origin forecastingtechniques to hypothesis placement prediction models for eachclinical stage with varying percentage of burn i.e. superficialwound, partial thickness or full thickness deep burn. Conclusivelywe proved that the depth of burn is directly proportionate to thedepth of patient’s placement in terms of window distance. Ourfindings support the hypothesis that the windowed wall is mosthealing wall, here fundamental suggestion is support vectormachines: which is most advantageous hyper plane for linearlydivisible patterns for the burns depth as well as the depth map isused.

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Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

10.26434/chemrxiv.7098695 ◽

2018 ◽

Author(s):

Elaine A. Kelly ◽

Judith E. Houston ◽

Rachel Evans

Keyword(s):

Real Time ◽

Absorption Spectroscopy ◽

Self Assembly ◽

Uv Light ◽

Wormlike Micelles ◽

Tetraethylene Glycol ◽

Light Illumination ◽

First Time ◽

Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such asdrug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis-and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in-situUV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4could switch between wormlike micelles (transnative state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in-situthrough combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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Ultrastructural studies of Chlamydia psittaci 6BC variant strains. I. Ultrastructure of the surface layers of egg-passaged 6BC strain

Canadian Journal of Microbiology ◽

10.1139/m73-142 ◽

1973 ◽

Vol 19 (8) ◽

pp. 887-894

Author(s):

Linda Poffenroth ◽

J. W. Costerton ◽

Nonna Kordová ◽

John C. Wilt

Keyword(s):

Chick Embryo ◽

Microscopic Examination ◽

Electron Microscopic Examination ◽

Chlamydia Psittaci ◽

Gram Negative Bacteria ◽

Surface Layers ◽

Electron Microscopic ◽

Gram Negative ◽

Ultrastructural Studies ◽

First Time

Electron microscopic examination of a semipurified Chlamydia psittaci 6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.

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The influence of behaviour modifying chemicals on mating success of the red bollworm Diparopsis castanea Hmps. (Lepidoptera, Noctuidae) in Malawi

Bulletin of Entomological Research ◽

10.1017/s0007485300006684 ◽

1976 ◽

Vol 66 (2) ◽

pp. 279-300 ◽

Cited By ~ 10

Author(s):

R. J. Marks

Keyword(s):

Sex Pheromone ◽

Sexual Attraction ◽

Practical Method ◽

Pheromone Trap ◽

Cotton Field ◽

Field Cage ◽

Synthetic Sex Pheromone ◽

Trap Catches ◽

First Time ◽

Lepidoptera Noctuidae

AbstractThe synthetic sex pheromone (dicastalure) of the red bollworm of cotton, Diparopsis castanea Hmps., in Central and Southern Africa, and an inhibitor of male sexual attraction (trans-9-dodecenyl acetate,=IIA), were used in an enclosed 0·2 ha cotton field-cage to reduce successful female matings. Over one month dicastalure at 21·0 and 42·3 g/ha produced average reductions in mating of 47·9% and 72·5% respectively and 37·9 g IIA/ha produced an overall reduction in mating of 71·5%, or 79·5% in released moth populations, over the same period. The proportion of virgin females present in disruption situations was significantly greater than in untreated populations and was density-independent for moth populations of up to 2 200/ha. The proportion of fertile eggs in disruption situations was correspondingly reduced to 30·2% from an average of 67·9% in control cycles. Reduction in sex pheromone trap catches is an unsatisfactory indicator of the extent to which males are prevented from inseminating females and considerably over-estimates the true degree of disruption. This is the first time that a naturally occurring inhibitor has been used successfully to disrupt mating in a field population of insects and it indicates the potential of the method for the control of high density pest populations in cotton. However, use of polyethylene dispensing mechanisms similar to those used in the field-cage disruption experiments would be unsuitable as a practical method of dispensing behaviour modifying chemicals and it is suggested that, for suitably controlled release of such chemicals, currently available microencapsulation technology offers the best prospects.

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Cymatosirella Dąbek, Witkowski & Sabbe gen. nov., a new marine benthic diatom genus (Bacillariophyta) belonging to the family Cymatosiraceae

Phytotaxa ◽

10.11646/phytotaxa.183.2.6 ◽

2014 ◽

Vol 183 (2) ◽

pp. 120

Author(s):

PRZEMYSŁAW DĄBEK ◽

KOEN SABBE ◽

ANDRZEJ WITKOWSKI ◽

COLIN ARCHIBALD ◽

KRZYSZOF J. KURZYDŁOWSKI ◽

...

Keyword(s):

New Genus ◽

Light And Electron Microscopy ◽

Benthic Diatom ◽

Western Cape ◽

Western Cape Province ◽

Line Drawings ◽

The Family ◽

Diatom Genus ◽

Electron Microscopical ◽

First Time

We present a new marine benthic diatom genus Cymatosirella gen. nov. The genus belongs to the family Cymatosiraceae and has been assigned to the subfamily Extubocelluloideae on the basis of ultrastructural cell wall features. It has isovalvate cells with undulate valves and is characterized by the absence of tubular processes and the occurrence of hollow spines which are observed for the first time in the Cymatosiraceae. The new genus contains four species, two of which are transferred from the genus Cymatosira, viz. Cymatosirella capensis comb. nov. and Cymatosirella minutissima comb. nov., and two which are new to science, viz. Cymatosirella benguelensis sp. nov. and Cymatosirella taylorii sp. nov. Cymatosirella capensis is chosen as the generitype. The new genus includes a group of very small taxa inhabiting the intertidal zone of the Atlantic Ocean with three species in South Africa and one in Europe. C. capensis was originally described by Giffen from Langebaan Lagoon (a shallow marine inlet in the southern part of Saldanha Bay, Western Cape Province), on the basis of light microscopy only, and has to date only been illustrated by line drawings. C. minutissima, so far only known from the Westerschelde estuary (The Netherlands), has previously been documented in more detail using both light and electron microscopy. Here, we present the results of detailed light and electron microscopical investigations of C. capensis, both from its original type material and from recently collected samples from the type locality and neighboring littoral areas in the Western Cape Province, and of the new species C. benguelensis and C. taylorii, also from Western Cape localities. All species are compared with similar small taxa belonging to the Cymatosiraceae, subfamily Extubocelluloideae.

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Temperature and UV light affect the activity of marine cell-free enzymes

Biogeosciences ◽

10.5194/bg-14-3971-2017 ◽

2017 ◽

Vol 14 (17) ◽

pp. 3971-3977 ◽

Cited By ~ 3

Author(s):

Blair Thomson ◽

Christopher David Hepburn ◽

Miles Lamare ◽

Federico Baltar

Keyword(s):

Organic Matter ◽

Extracellular Enzymes ◽

Elevated Temperatures ◽

Uv Light ◽

Control Mechanisms ◽

Potential Control ◽

Control Factors ◽

Rate Limiting Step ◽

Ocean Environment ◽

First Time

Abstract. Microbial extracellular enzymatic activity (EEA) is the rate-limiting step in the degradation of organic matter in the oceans. These extracellular enzymes exist in two forms: cell-bound, which are attached to the microbial cell wall, and cell-free, which are completely free of the cell. Contrary to previous understanding, cell-free extracellular enzymes make up a substantial proportion of the total marine EEA. Little is known about these abundant cell-free enzymes, including what factors control their activity once they are away from their sites (cells). Experiments were run to assess how cell-free enzymes (excluding microbes) respond to ultraviolet radiation (UVR) and temperature manipulations, previously suggested as potential control factors for these enzymes. The experiments were done with New Zealand coastal waters and the enzymes studied were alkaline phosphatase (APase), β-glucosidase, (BGase), and leucine aminopeptidase (LAPase). Environmentally relevant UVR (i.e. in situ UVR levels measured at our site) reduced cell-free enzyme activities by up to 87 % when compared to controls, likely a consequence of photodegradation. This effect of UVR on cell-free enzymes differed depending on the UVR fraction. Ambient levels of UV radiation were shown to reduce the activity of cell-free enzymes for the first time. Elevated temperatures (15 °C) increased the activity of cell-free enzymes by up to 53 % when compared to controls (10 °C), likely by enhancing the catalytic activity of the enzymes. Our results suggest the importance of both UVR and temperature as control mechanisms for cell-free enzymes. Given the projected warming ocean environment and the variable UVR light regime, it is possible that there could be major changes in the cell-free EEA and in the enzymes contribution to organic matter remineralization in the future.

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Redescription of Centronia melanitis Hübner, 1818 (Lepidoptera: Arctiinae: Arctiini: Ctenuchina) with notes on androconial organs

Entomological Communications ◽

10.37486/2675-1305.ec03029 ◽

2021 ◽

Vol 3 ◽

pp. ec03029

Author(s):

Juan Grados ◽

Karla Mantilla

Keyword(s):

Scientific Literature ◽

Sexual Attraction ◽

Museum Collections ◽

First Time

The Neotropical genus Centronia Hübner, 1818 is monotypic and represented by the species Centronia melanitis Hübner, 1818. Individuals of this species display diurnal habits and are attracted by plant bait of Heliotropium sp.. Specimens of Centronia are very rare in museum collections. The present study, notes are provided for the male specimens and the first time the female is mentioned in the scientific literature. The presence of androconial organs in Centronia melanitis and other species of Ctenuchina is hypothesized to be related to the visits to pyrrolizidine sources and their role in the pheromones production and the sexual attraction for mating.

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Measurement report: Biogenic VOC emissions profiles of Rapeseed leaf litter and their SOA formation potential

10.5194/acp-2021-135 ◽

2021 ◽

Author(s):

Letizia Abis ◽

Carmen Kalalian ◽

Bastien Lunardelli ◽

Tao Wang ◽

Liwu Zhang ◽

...

Keyword(s):

Uv Light ◽

Organic Aerosols ◽

Light Irradiation ◽

Large Contribution ◽

Biogenic Volatile Organic Compounds ◽

Voc Emissions ◽

Uv Light Irradiation ◽

Biogenic Voc ◽

Volatile Organic ◽

First Time

Abstract. We analysed the biogenic volatile organic compounds (BVOC) emissions from rapeseed leaves litter and their potential to create secondary organic aerosols (SOA) under three different conditions i.e., (i) in presence of UV light irradiation; (ii) in presence of ozone, and (iii) with both ozone and UV light. These experiments have been performed in a controlled atmospheric simulation chamber containing leaves litter samples, where BVOC and aerosol number concentrations have been measured for 6 days. Our results show that BVOC emission profiles were affected by UV light irradiation, which increased the summed BVOC emissions compared to the experiment with solely O3. Furthermore, the diversity of emitted VOCs from the rapeseed litter increased also in presence of UV light irradiation. SOA formation was observed when leaves litter were exposed to both UV light and O3, indicating a potentially large contribution to particle formation or growth at local scales. To our knowledge, this study investigates for the first time the effect of UV irradiation and O3 exposure on both VOC emissions and SOA formation for leaves litter samples. A detailed discussion about the processes behind the biological production of the most important VOC is proposed.

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PhotoATRP Induced Self-Assembly (PhotoATR-PISA) Enables Simplified Synthesis of Responsive Polymer Nanoparticles in One-Pot

10.26434/chemrxiv.12988559 ◽

2020 ◽

Author(s):

Ali Shahrokhinia ◽

Randall Scanga ◽

Priyanka Biswas ◽

James Reuther

Keyword(s):

Self Assembly ◽

Glycidyl Methacrylate ◽

Uv Light ◽

Copper Catalyst ◽

Crosslinking Agent ◽

Polymer Nanoparticles ◽

One Pot ◽

Responsive Polymer ◽

Catalyst Systems ◽

First Time

ABSTRACT: Photo-controlled atom transfer radical polymerization (PhotoATRP) was implemented, for the first time, to accomplish polymerization induced self-assembly (PISA) mediated by UV light (λ = 365 nm) using ppm levels (ca. < 20 ppm) of copper catalyst at ambient temperature. Using CuIIBr2/tris(pyridin-2-ylmethyl)amine (TPMA) catalyst systems, PISA was per-formed all in one-pot starting from synthesis of solvophilic poly(oligo(ethylene oxide) methyl ether methacrylate) (POEGMA) blocks to core-crosslinked nanoparticles (NPs) utilizing poly(glycidyl methacrylate) (PGMA) and N,N-cystamine bismethacrylamide (CBMA) as the solvophobic copolymer and crosslinking agent, respectively. Sequential chain-extensions were performed for PGMA demonstrating capabilities for accessing multi-block copolymers with temporal control via switching the UV light on and off. Further, core-crosslinking of PISA nanoparticles was performed via the slow incorporation of the CBMA enabling one-pot crosslinking during the PISA process. Finally, the disulfide installed in the CBMA core-crosslinks allowed for the stimuli-triggered dissociation of nanoparticles using DL-dithiothreitol at acidic pH.

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