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Horváth G, Dárdai B, Bíró M, Slíz-Balogh J, Száz D, Barta A, Egri Á. The all-day pollinator visits of sunflower inflorescences in Helianthus annuus plantations are independent of head orientation: Testing a widespread hypothesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 120:1563-1576. [PMID: 39395022 DOI: 10.1111/tpj.17070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 09/24/2024] [Accepted: 09/26/2024] [Indexed: 10/14/2024]
Abstract
Mature inflorescences of sunflowers (Helianthus annuus) orient constantly on average to the geographical east. According to one of the explanations of this phenomenon, the eastward orientation of sunflower inflorescences increases the number of attracted insect pollinators. We tested this hypothesis in three field experiments performed in flowering sunflower plantations. In experiments 1 and 2 we measured the number of insects trapped by the vertical walls of sticky sunflower models facing north, east, south, and west. In experiment 3 we counted the pollinators' landings on real sunflower inflorescences facing naturally east or turned artificially toward north, south, and west. We found that the all-day number of pollinators (predominantly bees) attracted to model and real sunflowers in H. annuus plantations is independent of the azimuth direction of sunflower heads, and after 10 h in the morning, the average number of pollinators counted every 20 min is practically constant in the rest of the day.
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Affiliation(s)
- Gábor Horváth
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
| | - Bence Dárdai
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
| | - Máté Bíró
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
| | - Judit Slíz-Balogh
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
| | - Dénes Száz
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
| | - András Barta
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
| | - Ádám Egri
- Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, Pázmány sétány 1, Budapest, H-1117, Hungary
- HUN-REN Centre for Ecological Research, Institute of Aquatic Ecology, Karolina út 29-31, Budapest, H-1113, Hungary
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2
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Cerkvenik U, Belušič G. Drinking on the wing: water collection in polarotactic horseflies. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:943-954. [PMID: 37477716 PMCID: PMC10643286 DOI: 10.1007/s00359-023-01657-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/28/2023] [Accepted: 07/10/2023] [Indexed: 07/22/2023]
Abstract
Many insects detect water bodies by observing the linearly polarised light which is reflected from the water surface. Polarotactic horseflies exhibit acrobatic manoeuvres above the water and are able to plunge on its surface, collect a droplet and fly away. This behaviour is extremely fast and has not yet been analysed. We recorded the flight patterns and kinematics of drinking horseflies using a pair of high-speed cameras. The animals of both sexes are attracted to water puddles where they make short, millisecond pitstops to collect a droplet of water that is then presumably drank "on the wing". Before the collection, the flies perform several low-altitude flybys above the puddle. After a few passes, the fly suddenly reverses its body orientation, decelerates, briefly touches the water surface and immediately flies away, usually with a droplet carried between its front legs. During the approach flight, the horseflies fly low but do not show any angular preference. Thus, they view the reflections from the sky, sun, or vegetation with a wide band of ventral ommatidia. Polarotaxis in drinking horseflies is a very robust visually guided behaviour, which operates at a broad range of intensities and various spectral compositions of reflected light.
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Affiliation(s)
- Uroš Cerkvenik
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, 1000, Ljubljana, Slovenia
| | - Gregor Belušič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, 1000, Ljubljana, Slovenia.
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3
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Beck M, Althaus V, Pegel U, Homberg U. Neurons sensitive to non-celestial polarized light in the brain of the desert locust. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:907-928. [PMID: 36809566 PMCID: PMC10643347 DOI: 10.1007/s00359-023-01618-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 01/20/2023] [Accepted: 02/04/2023] [Indexed: 02/23/2023]
Abstract
Owing to alignment of rhodopsin in microvillar photoreceptors, insects are sensitive to the oscillation plane of polarized light. This property is used by many species to navigate with respect to the polarization pattern of light from the blue sky. In addition, the polarization angle of light reflected from shiny surfaces such as bodies of water, animal skin, leaves, or other objects can enhance contrast and visibility. Whereas photoreceptors and central mechanisms involved in celestial polarization vision have been investigated in great detail, little is known about peripheral and central mechanisms of sensing the polarization angle of light reflected from objects and surfaces. Desert locusts, like other insects, use a polarization-dependent sky compass for navigation but are also sensitive to polarization angles from horizontal directions. In order to further analyze the processing of polarized light reflected from objects or water surfaces, we tested the sensitivity of brain interneurons to the angle of polarized blue light presented from ventral direction in locusts that had their dorsal eye regions painted black. Neurons encountered interconnect the optic lobes, invade the central body, or send descending axons to the ventral nerve cord but are not part of the polarization vision pathway involved in sky-compass coding.
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Affiliation(s)
- Marius Beck
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany
- Institute of Biology, University of Siegen, 57068, Siegen, Germany
| | - Vanessa Althaus
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany
| | - Uta Pegel
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps University of Marburg, 35032, Marburg, Germany.
- Center for Mind Brain and Behavior (CMBB), Philipps-University of Marburg and Justus Liebig University of Giessen, 35032, Marburg, Germany.
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4
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Mathejczyk TF, Babo ÉJ, Schönlein E, Grinda NV, Greiner A, Okrožnik N, Belušič G, Wernet MF. Behavioral responses of free-flying Drosophila melanogaster to shiny, reflecting surfaces. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:929-941. [PMID: 37796303 PMCID: PMC10643280 DOI: 10.1007/s00359-023-01676-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 09/14/2023] [Accepted: 09/16/2023] [Indexed: 10/06/2023]
Abstract
Active locomotion plays an important role in the life of many animals, permitting them to explore the environment, find vital resources, and escape predators. Most insect species rely on a combination of visual cues such as celestial bodies, landmarks, or linearly polarized light to navigate or orient themselves in their surroundings. In nature, linearly polarized light can arise either from atmospheric scattering or from reflections off shiny non-metallic surfaces like water. Multiple reports have described different behavioral responses of various insects to such shiny surfaces. Our goal was to test whether free-flying Drosophila melanogaster, a molecular genetic model organism and behavioral generalist, also manifests specific behavioral responses when confronted with such polarized reflections. Fruit flies were placed in a custom-built arena with controlled environmental parameters (temperature, humidity, and light intensity). Flight detections and landings were quantified for three different stimuli: a diffusely reflecting matt plate, a small patch of shiny acetate film, and real water. We compared hydrated and dehydrated fly populations, since the state of hydration may change the motivation of flies to seek or avoid water. Our analysis reveals for the first time that flying fruit flies indeed use vision to avoid flying over shiny surfaces.
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Affiliation(s)
- Thomas F Mathejczyk
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Édouard J Babo
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Erik Schönlein
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Nikolai V Grinda
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Andreas Greiner
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Nina Okrožnik
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Gregor Belušič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Mathias F Wernet
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Chemie and Pharmazie, Freie Universität Berlin, Königin-Luise Strasse 1-3, 14195, Berlin, Germany.
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5
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Han MJ, Tsukruk VV. Trainable Bilingual Synaptic Functions in Bio-enabled Synaptic Transistors. ACS NANO 2023; 17:18883-18892. [PMID: 37721448 PMCID: PMC10569090 DOI: 10.1021/acsnano.3c04113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023]
Abstract
The signal transmission of the nervous system is regulated by neurotransmitters. Depending on the type of neurotransmitter released by presynaptic neurons, neuron cells can either be excited or inhibited. Maintaining a balance between excitatory and inhibitory synaptic responses is crucial for the nervous system's versatility, elasticity, and ability to perform parallel computing. On the way to mimic the brain's versatility and plasticity traits, creating a preprogrammed balance between excitatory and inhibitory responses is required. Despite substantial efforts to investigate the balancing of the nervous system, a complex circuit configuration has been suggested to simulate the interaction between excitatory and inhibitory synapses. As a meaningful approach, an optoelectronic synapse for balancing the excitatory and inhibitory responses assisted by light mediation is proposed here by deploying humidity-sensitive chiral nematic phases of known polysaccharide cellulose nanocrystals. The environment-induced pitch tuning changes the polarization of the helicoidal organization, affording different hysteresis effects with the subsequent excitatory and inhibitory nonvolatile behavior in the bio-electrolyte-gated transistors. By applying voltage pulses combined with stimulation of chiral light, the artificial optoelectronic synapse tunes not only synaptic functions but also learning pathways and color recognition. These multifunctional bio-based synaptic field-effect transistors exhibit potential for enhanced parallel neuromorphic computing and robot vision technology.
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Affiliation(s)
- Moon Jong Han
- Department
of Electronic Engineering, Gachon University, Seongnam 13120, Republic of Korea
| | - Vladimir V. Tsukruk
- School
of Materials Science and Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
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6
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Peredo Arce A, Palt M, Schletterer M, Kail J. Has riparian woody vegetation a positive effect on dispersal and distribution of mayfly, stonefly and caddisfly species? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:163137. [PMID: 37001668 DOI: 10.1016/j.scitotenv.2023.163137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/24/2023] [Accepted: 03/24/2023] [Indexed: 05/17/2023]
Abstract
During their adult life stage most EPTs (Ephemeroptera, Plecoptera and Trichoptera) disperse by flying following the riparian corridor. Although it is likely that riparian forest fosters EPT dispersion, this has not been empirically tested in a larger dataset yet and several additional open questions remain. First, it is unclear if the effect of riparian vegetation on EPT community differs and depends on the spatial scale. Second, it is not assessed how the effect of riparian vegetation on EPTs is and how it changes depending on other environmental stressors. Third, the effect potentially depends on riparian vegetation characteristics such as trees species composition and cover. We analysed 98 sites in lowland and lower mountain streams in Northrhine Westfalia, Germany, at two longitudinal and two lateral spatial scales. At each site we calculated the EPT community dispersal ability and quantified other environmental stressors as well as deciduous and coniferous woody cover in the riparian buffer. Generalised Linear Models were used to identify the conditions under which woody riparian vegetation has a significant effect on EPT community dispersal ability. Our results confirmed that the share of weak dispersers increased with deciduous woody riparian cover in low mountain streams, indicating a potential positive effect of natural riparian forest on landscape connectivity. This relationship was only observed at the regional longitudinal scale irrespective of the lateral spatial scale. Tree species composition was relevant as coniferous forests did not contribute to this effect. Finally, there was some indication that the positive effect of deciduous riparian forest occurs at a moderate woody cover and levels off at higher values. This highlights the role of riparian forests not only as habitat but also dispersal corridor in river management and the need to preserve and restore natural woody riparian vegetation to improve EPT communities and macroinvertebrates ecological status.
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Affiliation(s)
| | - M Palt
- University of Duisburg-Essen, Essen, Germany; Environmental Campus Birkenfeld, University of Applied Sciences Trier, Birkenfeld, Germany
| | - M Schletterer
- University of Natural Resources and Life Sciences, Vienna, Austria
| | - J Kail
- University of Duisburg-Essen, Essen, Germany
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7
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Egri Á, Mészáros Á, Kriska G. Spectral sensitivity transition in the compound eyes of a twilight-swarming mayfly and its visual ecological implications. Proc Biol Sci 2022; 289:20220318. [PMID: 35473376 PMCID: PMC9043733 DOI: 10.1098/rspb.2022.0318] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aquatic insect species that leave the water after larval development, such as mayflies, have to deal with extremely different visual environments in their different life stages. Measuring the spectral sensitivity of the compound eyes of the virgin mayfly (Ephoron virgo) resulted in differences between the sensitivity of adults and larvae. Larvae were primarily green-, while adults were mostly UV-sensitive. The sensitivity of adults and larvae was the same in the UV, but in the green spectral range, adults were 3.3 times less sensitive than larvae. Transmittance spectrum measurements of larval skins covering the eye showed that the removal of exuvium during emergence cannot explain the spectral sensitivity change of the eyes. Taking numerous sky spectra from the literature, the ratio of UV and green photons in the skylight was shown to be maximal for θ ≈ -13° solar elevation, which is in the θmin = -14.7° and θmax = -7.1° typical range of swarming that was established from webcam images of real swarmings. We suggest that the spectral sensitivity of both the larval and adult eyes are adapted to the optical environment of the corresponding life stages.
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Affiliation(s)
- Ádám Egri
- Institute of Aquatic Ecology, Centre for Ecological Research, Karolina út 29, Budapest H-1113, Hungary
| | - Ádám Mészáros
- Institute of Aquatic Ecology, Centre for Ecological Research, Karolina út 29, Budapest H-1113, Hungary.,Doctoral School of Environmental Sciences, Eötvös University, Pázmány sétány 1, Budapest H-1117 Hungary.,Group for Methodology in Biology Teaching, Biological Institute, Eötvös University, Pázmány sétány 1, Budapest H-1117, Hungary
| | - György Kriska
- Institute of Aquatic Ecology, Centre for Ecological Research, Karolina út 29, Budapest H-1113, Hungary.,Group for Methodology in Biology Teaching, Biological Institute, Eötvös University, Pázmány sétány 1, Budapest H-1117, Hungary
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8
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Yadav P, Shein-Idelson M. Polarization vision in invertebrates: beyond the boundaries of navigation. CURRENT OPINION IN INSECT SCIENCE 2021; 48:50-56. [PMID: 34628060 DOI: 10.1016/j.cois.2021.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 08/16/2021] [Accepted: 09/21/2021] [Indexed: 05/05/2023]
Abstract
Invertebrates possess the unique ability to see polarized light. This allows them to exploit the rich polarization information embedded in their natural environments: patterns in plants, high contrast on water surfaces, distinctive signatures of conspecifics, and the celestial polarization pattern around the sun. From this wide repertoire of polarization signals, studies have primarily focused on understanding how celestial polarization information is converted into an internal compass. This review highlights several studies which suggest that spatio-temporal polarization information is utilized by insects for additional functions, such as signaling, detection, contrast enhancement, and host assessment. It concludes by evaluating recent technological advances for uncovering the full repertoire of polarization-sensitivity in invertebrates.
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Affiliation(s)
- Pratibha Yadav
- Sagol School of Neuroscience, Tel Aviv University, Israel; School of Zoology, Tel Aviv University, Israel
| | - Mark Shein-Idelson
- Sagol School of Neuroscience, Tel Aviv University, Israel; School of Neurobiology, Biochemistry, and Biophysics, Tel Aviv University, Israel.
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9
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Fritz KM, Nadeau TL, Kelso JE, Beck WS, Mazor RD, Harrington RA, Topping BJ. Classifying Streamflow Duration: The Scientific Basis and an Operational Framework for Method Development. WATER 2020; 12:1-2545. [PMID: 33133647 PMCID: PMC7592706 DOI: 10.3390/w12092545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Streamflow duration is used to differentiate reaches into discrete classes (e.g., perennial, intermittent, and ephemeral) for water resource management. Because the depiction of the extent and flow duration of streams via existing maps, remote sensing, and gauging is constrained, field-based tools are needed for use by practitioners and to validate hydrography and modeling advances. Streamflow Duration Assessment Methods (SDAMs) are rapid, reach-scale indices or models that use physical and biological indicators to predict flow duration class. We review the scientific basis for indicators and present conceptual and operational frameworks for SDAM development. Indicators can be responses to or controls of flow duration. Aquatic and terrestrial responses can be integrated into SDAMs, reflecting concurrent increases and decreases along the flow duration gradient. The conceptual framework for data-driven SDAM development shows interrelationships among the key components: study reaches, hydrologic data, and indicators. We present a generalized operational framework for SDAM development that integrates the data-driven components through five process steps: preparation, data collection, data analysis, evaluation, and implementation. We highlight priorities for the advancement of SDAMs, including expansion of gauging of nonperennial reaches, use of citizen science data, adjusting for stressor gradients, and statistical and monitoring advances to improve indicator effectiveness.
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Affiliation(s)
- Ken M. Fritz
- Center for Environmental Measurement and Modeling, Office of Research and Development, US Environmental Protection Agency, Cincinnati, OH 45268, USA
| | - Tracie-Lynn Nadeau
- Region 10, US Environmental Protection Agency, Portland, OR 97205, USA
- Office of Wetlands, Oceans, and Watersheds, US Environmental Protection Agency, Washington, DC 20460, USA
| | - Julia E. Kelso
- Office of Wetlands, Oceans, and Watersheds, US Environmental Protection Agency, Washington, DC 20460, USA
- Oak Ridge Institute for Science and Education Fellow, Oak Ridge, TN 37831, USA
| | - Whitney S. Beck
- Office of Wetlands, Oceans, and Watersheds, US Environmental Protection Agency, Washington, DC 20460, USA
| | - Raphael D. Mazor
- Southern California Coastal Water Research Project, Costa Mesa, CA 92626, USA
| | - Rachel A. Harrington
- Office of Wetlands, Oceans, and Watersheds, US Environmental Protection Agency, Washington, DC 20460, USA
| | - Brian J. Topping
- Office of Wetlands, Oceans, and Watersheds, US Environmental Protection Agency, Washington, DC 20460, USA
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10
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Egri Á, Kriska G, Horváth G. Method to reduce motion artifacts of sequential imaging polarimetry: long enough exposures minimize polarization blurs of wavy water surfaces. APPLIED OPTICS 2018; 57:7564-7569. [PMID: 30461822 DOI: 10.1364/ao.57.007564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/14/2018] [Indexed: 06/09/2023]
Abstract
Researchers studying the polarization characteristics of the optical environment prefer to use sequential imaging polarimetry, because it is inexpensive and simple. This technique takes polarization pictures through polarizers in succession. Its main drawback is, however, that during sequential exposure of the polarization pictures, the target must not move, otherwise so-called motion artifacts are caused after evaluation of the polarization pictures. How could these disturbing motion artifacts be minimized? Taking inspiration from photography, our idea was to take the polarization pictures with an exposure that is long enough so that the changes of the moving/changing target can be averaged and, thus, motion artifacts are reduced, at least in a special case when the motion has a stable mean. In the laboratory, we demonstrated the performance of this method when the target was a wavy water surface. We found that the errors of the measured degree and angle of polarization of light reflected from the undulating water surface decreased with increasing exposure time (shutter speed) and converged to very low values. Although various simultaneous polarimeters (taking the polarization pictures at once) are available that do not suffer from motion artifacts, our method is much cheaper and performs very well, at least when the target is a wavy water surface.
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11
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Heinloth T, Uhlhorn J, Wernet MF. Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits. Front Cell Neurosci 2018; 12:50. [PMID: 29615868 PMCID: PMC5870057 DOI: 10.3389/fncel.2018.00050] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 02/15/2018] [Indexed: 12/13/2022] Open
Abstract
The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the “Dorsal Rim Area” (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster, we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision.
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Affiliation(s)
- Tanja Heinloth
- Division of Neurobiology, Institut für Biology, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität Berlin, Berlin, Germany
| | - Juliane Uhlhorn
- Division of Neurobiology, Institut für Biology, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität Berlin, Berlin, Germany
| | - Mathias F Wernet
- Division of Neurobiology, Institut für Biology, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität Berlin, Berlin, Germany
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12
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Egri Á, Száz D, Farkas A, Pereszlényi Á, Horváth G, Kriska G. Method to improve the survival of night-swarming mayflies near bridges in areas of distracting light pollution. ROYAL SOCIETY OPEN SCIENCE 2017; 4:171166. [PMID: 29291103 PMCID: PMC5717677 DOI: 10.1098/rsos.171166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/17/2017] [Indexed: 06/07/2023]
Abstract
Numerous negative ecological effects of urban lighting have been identified during the last decades. In spite of the development of lighting technologies, the detrimental effect of this form of light pollution has not declined. Several insect species are affected including the night-swarming mayfly Ephoron virgo: when encountering bridges during their mass swarming, these mayflies often fall victim to artificial lighting. We show a simple method for the conservation of these mayflies exploiting their positive phototaxis. With downstream-facing light-emitting diode beacon lights above two tributaries of the river Danube, we managed to guide egg-laying females to the water and prevent them from perishing outside the river near urban lights. By means of measuring the mayfly outflow from the river as a function of time and the on/off state of the beacons, we showed that the number of mayflies exiting the river's area was practically zero when our beacons were operating. Tributaries could be the sources of mayfly recolonization in case of water quality degradation of large rivers. The protection of mayfly populations in small rivers and safeguarding their aggregation and oviposition sites is therefore important.
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Affiliation(s)
- Ádám Egri
- MTA Centre for Ecological Research, Danube Research Institute, 1113 Budapest, Karolina út 29-31, Hungary
- Environmental Optics Laboratory, Department of Biological Physics, Physical Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Dénes Száz
- Environmental Optics Laboratory, Department of Biological Physics, Physical Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Alexandra Farkas
- MTA Centre for Ecological Research, Danube Research Institute, 1113 Budapest, Karolina út 29-31, Hungary
- Environmental Optics Laboratory, Department of Biological Physics, Physical Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - Ádám Pereszlényi
- Environmental Optics Laboratory, Department of Biological Physics, Physical Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
- Department of Zoology, Hungarian Natural History Museum, Bird Collection, 1083 Budapest, Ludovika tér 2-6, Hungary
| | - Gábor Horváth
- Environmental Optics Laboratory, Department of Biological Physics, Physical Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
| | - György Kriska
- MTA Centre for Ecological Research, Danube Research Institute, 1113 Budapest, Karolina út 29-31, Hungary
- Group for Methodology in Biology Teaching, Biological Institute, ELTE Eötvös Loránd University, 1117 Budapest, Pázmány sétány 1, Hungary
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