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 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.

Quantum fountain infrared light sources based on intersubband emissions in quantum wells

1999 ◽  
Vol 09 (PR2) ◽  
pp. Pr2-161
Author(s):  
F. H. Julien ◽  
P. Boucaud ◽  
S. Sauvage ◽  
O. Gauthier-Lafaye ◽  
Z. Moussa
Keyword(s):  
Quantum Wells ◽  
Infrared Light ◽  
Light Sources

Immobilization of ZnO Suspension on Glass Substrate to Remove Filtration During the Removal of Remazol Red R from Aqueous Solution

2016 ◽  
Vol 12 (6) ◽  
pp. 4127-4133
Author(s):  
Nazmul Kayes ◽  
Jalil Miah ◽  
Md. Obaidullah ◽  
Akter Hossain ◽  
Mufazzal Hossain
Keyword(s):  
Aqueous Solution ◽  
Glass Substrate ◽  
Uv Light ◽  
Aqueous Suspension ◽  
Light Irradiation ◽  
Zno Films ◽  
Light Sources ◽  
Zno Film ◽  
Semiconductor Oxides ◽  
Remazol Red

Photodegradation of textile dyes in the presence of an aqueous suspension of semiconductor oxides has been of growing interest. Although this method of destruction of dyes is efficient, the main obstacle of applying this technique in the industry is the time and cost involving separation of oxides from an aqueous suspension. In this research, an attempted was made to develop ZnO films on a glass substrate by simple immobilization method for the adsorption and photodegradation of a typical dye, Remazol Red R (RRR) from aqueous solution. Adsorption and photodegradation of  RRR were performed in the presence of glass supported ZnO film. Photodegradation of the dye was carried out by varying different parameters such as the catalyst dosage, initial concentrations of RRR, and light sources. The percentage of adsorption as well as photodegradation increased with the amount of ZnO, reaches a maximum and then decreased. Maximum degradation has been found under solar light irradiation as compared to UV-light irradiation. Removal efficiency was also found to be influenced by the pre-sonication of ZnO suspension.

Research on the Economic Organization Environmental Impact

2017 ◽  
Vol 68 (3) ◽  
pp. 599-601
Author(s):  
Dan Paul Stefanescu ◽  
Oana Roxana Chivu ◽  
Claudiu Babis ◽  
Augustin Semenescu ◽  
Alina Gligor
Keyword(s):  
Economic Activity ◽  
Economic Organization ◽  
Economic Activities ◽  
Environmental Implications ◽  
Minimal Impact ◽  
Wide Range ◽  
Material Environment ◽  
Negative Effect ◽  
Harmful Effects

Any economic activity carried out by an organization, can generate a wide range of environmental implications. Particularly important, must be considered the activities that have a significant negative effect on the environment, meaning those which pollute. Being known the harmful effects of pollution on the human health, the paper presents two models of utmost importance, one of the material environment-economy interactions balance and the other of the material flows between environmental factors and socio-economic activities. The study of these models enable specific conditions that must be satisfied for the economic processes friendly coexist to the environment for long term, meaning to have a minimal impact in that the residues resulting from the economic activity of the organization to be as less harmful to the environment.

Green Synthesis of ZnO/Dy/NiO Heterostructures for Enhanced Photocatalytic Applications

2020 ◽  
Vol 1 (1) ◽  
pp. 30-36
Author(s):  
Shubha Jayachamarajapura Pranesh ◽  
Diwya Lanka
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Combustion Method ◽  
Hybrid Nanocomposites ◽  
Synthetic Dyes ◽  
Hybrid Nanostructure ◽  
Wide Range ◽  
Visible Light Active ◽  
Textile Industries ◽  
Photocatalytic Applications

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.

Associated microflora of medicinal ferns: biotechnological potentials and possible applications

2016 ◽  
Vol 5 (03) ◽  
pp. 4927 ◽  
Author(s):  
Shubhi Srivastava ◽  
Paul A. K.
Keyword(s):  
Secondary Metabolites ◽  
Growth Promotion ◽  
Biological Activities ◽  
Hydrolytic Enzymes ◽  
In Vitro Production ◽  
Wide Range ◽  
Negative Effect ◽  
Bacteria And Fungi

Plant associated microorganisms that colonize the upper and internal tissues of roots, stems, leaves and flowers of healthy plants without causing any visible harmful or negative effect on their host. Diversity of microbes have been extensively studied in a wide variety of vascular plants and shown to promote plant establishment, growth and development and impart resistance against pathogenic infections. Ferns and their associated microbes have also attracted the attention of the scientific communities as sources of novel bioactive secondary metabolites. The ferns and fern alleles, which are well adapted to diverse environmental conditions, produce various secondary metabolites such as flavonoids, steroids, alkaloids, phenols, triterpenoid compounds, variety of amino acids and fatty acids along with some unique metabolites as adaptive features and are traditionally used for human health and medicine. In this review attention has been focused to prepare a comprehensive account of ethnomedicinal properties of some common ferns and fern alleles. Association of bacteria and fungi in the rhizosphere, phyllosphere and endosphere of these medicinally important ferns and their interaction with the host plant has been emphasized keeping in view their possible biotechnological potentials and applications. The processes of host-microbe interaction leading to establishment and colonization of endophytes are less-well characterized in comparison to rhizospheric and phyllospheric microflora. However, the endophytes are possessing same characteristics as rhizospheric and phyllospheric to stimulate the in vivo synthesis as well as in vitro production of secondary metabolites with a wide range of biological activities such as plant growth promotion by production of phytohormones, siderophores, fixation of nitrogen, and phosphate solubilization. Synthesis of pharmaceutically important products such as anticancer compounds, antioxidants, antimicrobials, antiviral substances and hydrolytic enzymes could be some of the promising areas of research and commercial exploitation.

scholarly journals Formation of Carbon Quantum Dots via Hydrothermal Carbonization: Investigate the Effect of Precursors

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 986
Author(s):  
Md Rifat Hasan ◽  
Nepu Saha ◽  
Thomas Quaid ◽  
M. Toufiq Reza
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Synthesis Method ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Medical Diagnostics ◽  
Particle Size Range ◽  
Wide Range

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

New Mid-Infrared Light Sources

2012 ◽  
Vol 18 (1) ◽  
pp. 531-540 ◽  
Author(s):  
Jens Biegert ◽  
Philip K. Bates ◽  
Olivier Chalus
Keyword(s):  
Infrared Light ◽  
Light Sources ◽  
Mid Infrared
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