A NOVEL METHOD FOR STUDYING THRESHOLD LEVELS FOR POSITIVE PHOTOTAXIS IN INSECTS

2021 ◽  
Author(s):  
M. Nilsson Tengelin ◽  
A.K. Jägerbrand ◽  
P. Andersson ◽  
S. Källberg
Keyword(s):  
Spectral Composition ◽  
Light Response ◽  
Optical Filters ◽  
Ecological Impacts ◽  
Infrared Light ◽  
Positive Phototaxis ◽  
Threshold Levels ◽  
Light Levels ◽  
Novel Method ◽  
Effect Of Light

This paper presents a novel method for studying threshold levels for positive phototaxis of insects and smaller mobile organisms. Outdoor lighting affects light sensitive species and there is a need to evaluate the effect of light levels, spectral composition of the light and light distribution to mitigate the ecological impacts of the artificial light. For this purpose, a test box investigating the effect of light on insects in a controlled manner has been constructed. The box is equipped with a luminance source and the light levels can be varied from a maximum value continuously down to zero. The spectral composition of the light can be varied by changing the lamp or using optical filters. For visibility of the insects the box has infrared light emitting diodes in the ceiling and two wide-angle cameras monitor the light response. The functionality of the box is tested with the species greater wax moth.

scholarly journals Suspended Sediment Modeling Using a Heuristic Regression Method Hybridized with Kmeans Clustering

2021 ◽  
Vol 13 (9) ◽  
pp. 4648
Author(s):  
Rana Muhammad Adnan ◽  
Kulwinder Singh Parmar ◽  
Salim Heddam ◽  
Shamsuddin Shahid ◽  
Ozgur Kisi
Keyword(s):  
Clustering Algorithm ◽  
Suspended Sediments ◽  
Ecological Impacts ◽  
Accurate Estimation ◽  
Data Sets ◽  
The Novel ◽  
Neuro Fuzzy ◽  
Adaptive Regression ◽  
Novel Method ◽  
Model Training

The accurate estimation of suspended sediments (SSs) carries significance in determining the volume of dam storage, river carrying capacity, pollution susceptibility, soil erosion potential, aquatic ecological impacts, and the design and operation of hydraulic structures. The presented study proposes a new method for accurately estimating daily SSs using antecedent discharge and sediment information. The novel method is developed by hybridizing the multivariate adaptive regression spline (MARS) and the Kmeans clustering algorithm (MARS–KM). The proposed method’s efficacy is established by comparing its performance with the adaptive neuro-fuzzy system (ANFIS), MARS, and M5 tree (M5Tree) models in predicting SSs at two stations situated on the Yangtze River of China, according to the three assessment measurements, RMSE, MAE, and NSE. Two modeling scenarios are employed; data are divided into 50–50% for model training and testing in the first scenario, and the training and test data sets are swapped in the second scenario. In Guangyuan Station, the MARS–KM showed a performance improvement compared to ANFIS, MARS, and M5Tree methods in term of RMSE by 39%, 30%, and 18% in the first scenario and by 24%, 22%, and 8% in the second scenario, respectively, while the improvement in RMSE of ANFIS, MARS, and M5Tree was 34%, 26%, and 27% in the first scenario and 7%, 16%, and 6% in the second scenario, respectively, at Beibei Station. Additionally, the MARS–KM models provided much more satisfactory estimates using only discharge values as inputs.

scholarly journals Effect of light on aggregational behavior of planarian Dugesia tigrina

2017 ◽  
Author(s):  
Jaemin Lee
Keyword(s):  
Defense Mechanisms ◽  
Uv Light ◽  
Infrared Light ◽  
Light Sources ◽  
Initial Exposure ◽  
Dugesia Tigrina ◽  
Wide Range ◽  
Photophobic Response ◽  
Negative Effect ◽  
Effect Of Light

Introduction. Planarians are renowned for their regenerative ability due to pluripotent stem cells, as well as their peculiar photophobic response. However, few facts are known about their aggregational behavior. This study aims to reveal the effect of light on aggregational behavior. Reynierse (1966) suggested that light has a negative effect on the formation of aggregations. However, one of his objectives for aggregational behavior was inappropriate. This study reevaluated the effect of existence of light on aggregational behavior, as well as ascertained the effect of wavelength on the formation of aggregations. Methods. In this study, the ratio of individuals participating in aggregations was measured as a criterion to determine aggregational behavior. Aggregational behavior was measured after two hours from the initial exposure to different light sources. The behaviors under white LED light and under shade were compared, as well as the behaviors under five different light sources: infrared lamp, red, green, blue LED, and ultraviolet lamp. Results. The existence of light interfered the formation of aggregations (t-test, p < 0.0001), which supports the former study of Reynierse. Also, aggregational behavior differed under different wavelengths (ANOVA, p < 0.0001). Except for the infrared light which emitted a wide range of wavelengths, the behavior showed hierarchy: decreasing aggregational behavior in accordance with decreasing wavelength. UV light has the most significant negative effect on the formation of aggregations. Discussion. Exposure to light caused negative effects on performing aggregational behavior. Participation in aggregations appears to be influenced by photophobic response, especially under lights of short wavelength. Disintegrating aggregations under exposure to lights can potentially bring evolutionary benefit. This behavior possibly makes the aggregating planarians altogether exposed to a higher risk or predation, considering that they lack defense mechanisms. Planarians can lower the risk and continue the populations by disintegrating the aggregational behavior under the existence of UV and lights of higher wavelength, which are indicatives of daytime. Understanding aggregational behavior of animals of a lower order would give better insight on general herding behavior, and potentially help interpreting more complex behaviors of higher animals.

scholarly journals Enhancement of Titania Photoanode Performance by Sandwiching Copper between Two Titania Layers

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4326
Author(s):  
Fan Yang ◽  
Ruizhuang Yang ◽  
Lin Yan ◽  
Jiankun Wu ◽  
Xiaolin Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Sandwich Structure ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Light Response ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Tio2 Lattice ◽  
Novel Method ◽  
Cu Dopant

Vacancies in semiconductors can play a versatile role in boosting their photocatalytic activity. In this work, a novel TiO2/Cu/TiO2 sandwich structure is designed and constructed. Abundant vacancies were introduced in TiO2 lattice by Cu reduction under heat treatment. Meanwhile, Cu atom could diffuse into TiO2 to form Cu-doped TiO2. The synergistic effect between oxygen vacancies and Cu atoms achieved about 2.4 times improved photocurrent of TiO2/Cu/TiO2 sandwich structure compared to bare TiO2 thin film. The enhanced photoactivity may be attributed to regulated electron structure of TiO2 by oxygen vacancies and Cu dopant from experimental results and density functional theory calculations. Oxygen vacancies and Cu dopant in TiO2 formed through copper metal reduction can introduce impurity levels and narrow the band gap of TiO2, thus improve the visible light response. More importantly, the Cu2+ and oxygen vacancies in TiO2 lattice can dramatically increase the charge density around conduction band and promote separation of photo-induced charge carriers. Furthermore, the oxygen vacancies on the surface may serve as active site for sufficient chemical reaction. This work presents a novel method to prepare doped metal oxides catalysts with abundant vacancies for improving photocatalytic activity.

scholarly journals Light Exposure during Days with Night, Outdoor, and Indoor Work

2019 ◽  
Vol 63 (6) ◽  
pp. 651-665 ◽  
Author(s):  
Stine Daugaard ◽  
Jakob Markvart ◽  
Jens Peter Bonde ◽  
Jens Christoffersen ◽  
Anne Helene Garde ◽  
...  
Keyword(s):  
Light Intensity ◽  
Light Exposure ◽  
Spectral Composition ◽  
Working Hours ◽  
Well Being ◽  
Outdoor Workers ◽  
Light Levels ◽  
Light Intensities ◽  
Treatment Of Depression ◽  
Night Shifts

Abstract Objective To assess light exposure during days with indoor, outdoor, and night work and days off work. Methods Light intensity was continuously recorded for 7 days across the year among indoor (n = 170), outdoor (n = 151), and night workers (n = 188) in Denmark (55–56°N) equipped with a personal light recorder. White light intensity, duration above 80, 1000, and 2500 lux, and proportion of red, green, and blue light was depicted by time of the day and season for work days and days off work. Results Indoor workers’ average light exposure only intermittently exceeded 1000 lux during daytime working hours in summer and never in winter. During daytime working hours, most outdoor workers exceeded 2500 lux in summer and 1000 lux in winter. Night workers spent on average 10–50 min &gt;80 lux when working night shifts. During days off work, indoor and night workers were exposed to higher light intensities than during work days and few differences were seen between indoor, outdoor, and night workers. The spectral composition of light was similar for indoor, outdoor, and night workers during days at and off work. Conclusion The night workers of this study were during night hours on average exposed for a limited time to light intensities expected to suppress melatonin. The indoor workers were exposed to light levels during daylight hours that may reduce general well-being and mood, especially in winter. Outdoor workers were during summer daylight hours exposed to light levels comparable to those used for the treatment of depression.

A Novel Application of Vehicle Security by Infrared Camera and Coating Technology

2011 ◽  
Vol 396-398 ◽  
pp. 981-987
Author(s):  
Jen Yu Shieh ◽  
Ji Sheng Hsieh ◽  
Chih Ming Lin ◽  
Yueh Hsun Lee
Keyword(s):  
Wireless Communication ◽  
Incident Light ◽  
Infrared Camera ◽  
Infrared Light ◽  
Dark Condition ◽  
Coating Technology ◽  
Infrared Photography ◽  
Novel Method ◽  
Vehicle Security ◽  
Pass Through

In the paper, a novel method is proposed for application of vehicle security by infrared camera and coating technology. In this Vehicle Security System (VSS), the traditional mirror is coated on the surface with special material by multi-layers, then, an infrared camera is placed behind the mirror on the bottom of device. In order to obtain the image, a wireless communication is integrated on this system. Therefore, the user can easily inspect the object under the vehicle. By using this infrared photography, it provides completely imaging for the total dark condition, to examine the under-vehicle area of an object or explosives. Experiments show that the proposed device reflected 80% of visible light and penetrated 20% of incident light, about 96% infrared light pass through the mirror.

Chemiluminescence - A Novel Method in the Research of Degradation of Paper. I. The Effect of Light on Stacked Sheets of Paper

2007 ◽  
Vol 247 (1) ◽  
pp. 340-349 ◽  
Author(s):  
Lyda Matisová-Rychlá ◽  
Vladimír Bukovský ◽  
Jozef Rychlý ◽  
Martina Pleteníková
Keyword(s):  
Novel Method ◽  
Effect Of Light

Carotenoid pigments: their possible role in protecting against photooxidation in eyes and photoreceptor cells

1982 ◽  
Vol 216 (1202) ◽  
pp. 71-85 ◽  
Keyword(s):  
Plant Tissue ◽  
Photoreceptor Cells ◽  
Cellular Damage ◽  
Carotenoid Pigments ◽  
Animal Tissues ◽  
Light Spectrum ◽  
High Exposure ◽  
Light Levels ◽  
Gain Energy ◽  
Effect Of Light

The effect of light on animal tissues is ambivalent. Light is necessary for many functions, e. g. for vision and, as in the flagellate halobacterium, to gain energy. But light is potentially dangerous: it is capable of destroying cells or their components by photooxidation, especially in the presence of sensitizing pigments such as haems and cytochromes, which are ubiquitous in aerobic cells. Several different examples are discussed to show how a compromise is achieved in animal tissues that for functional reasons receive high exposure to light. Carotenoid pigments, present in many eyes and photoreceptors, seem especially suited to protect against the deleterious effects of light because they absorb the dangerous short wavelength part of the light spectrum. In plant tissue, carotenoids are also well known to be capable of ‘quenching’ photoexcited states of sensitizing pigments and of oxygen, a function that they might have also in animal tissues. A consequence of the considerations is that whenever animal tissues are exposed to higher than usual light levels and/or oxygen pressures cellular damage might occur. Examples are discussed; strategies to circumvent the deleterious effects by photooxidation follow directly from the arguments.

scholarly journals The effect of light on N<sub>2</sub> fixation and net nitrogen release of field <i>Trichodesmium</i>

2017 ◽  
Author(s):  
Yangyang Lu ◽  
Zuozhu Wen ◽  
Dalin Shi ◽  
Mingming Chen ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Model Prediction ◽  
Carbon Fixation ◽  
Physiological State ◽  
Light Stress ◽  
Light Response ◽  
Light Change ◽  
Filamentous Cyanobacterium ◽  
Net Release ◽  
Effect Of Light

Abstract. Dinitrogen fixation (NF) by marine cyanobacteria is a crucial pathway to replenish the oceanic bioavailable nitrogen inventory. Light is the key to modulate NF, however, field studies regarding light response curve (NF-I curve) of NF rate and the effect of light on diazotroph derived nitrogen (DDN) net release are missing that may hamper an accurate nitrogen model prediction. Uncontaminated 15N2 gas dissolution method was applied to examine how the light change may influence the NF intensity and DDN net release in the oligotrophic ocean. Experiments were conducted at stations with diazotrophs dominated by filamentous cyanobacterium Trichodesmium spp. in the Western Pacific and the South China Sea. The light effect on carbon fixation (CF) was measured in parallel using the 13C labelling method specifically for a station characterized by Trichodesmium bloom. Both NF-I and CF-I curves showed Ik (light saturation coefficient) range of 328 to 509 μE m−2 s−1 with saturation light at around 600 μE m−2 s−1. The proportion of DDN net release ranged from ~6% to ~50% revealing an increasing trend as the light intensity decreased. At the Trichodesmium bloom station, we found CF/NF ratio was light-dependent and the ratio started to increase as light was lower than the carbon compensation point of 300 μE m−2 s−1. NF pathway was likely preferentially blocked under low light to conserve energy for photosynthesis, thus, there is a metabolism tradeoff between carbon and nitrogen fixation pathways under light stress. Results showed that short-term light change modulates the physiological state, which subsequently determined the C/N metabolism and DDN net release of field Trichodesmium. Energy reallocation associated with the variations of field light intensity would be helpful for model prediction of global biogeochemical cycle involved with Trichodesmium.

scholarly journals A simple PVA/Cu(OAc)2 thermogel with an inherent near-infrared light response and its applications in smart windows and photoresistors

2020 ◽  
Vol 8 (34) ◽  
pp. 17800-17807
Author(s):  
Hao Zhang ◽  
Jie Hao ◽  
Xia Yu ◽  
Jianqiao Wu ◽  
Jiawei Li ◽  
...  
Keyword(s):  
Near Infrared ◽  
Light Response ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Smart Windows

A PVA/Cu(OAc)2 thermogel with an inherent NIR photothermal response was prepared, and its applications in smart windows and photoresistors were explored.

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