Effects of nano-TiO2 on Chlamydomonas reinhardtii cell surface under UV, natural light conditions

2017 ◽  
Vol 32 (1) ◽  
pp. 217-222 ◽  
Author(s):  
Xiaojuan Chen ◽  
Ruirui Lu ◽  
Peng Liu ◽  
Xi Li
Keyword(s):  
Cell Surface ◽  
Chlamydomonas Reinhardtii ◽  
Natural Light ◽  
Light Conditions ◽  
Nano Tio2

scholarly journals Development of a cell surface display system in Chlamydomonas reinhardtii

2022 ◽  
Vol 61 ◽  
pp. 102570
Author(s):  
João Vitor Dutra Molino ◽  
Roberta Carpine ◽  
Karl Gademann ◽  
Stephen Mayfield ◽  
Simon Sieber
Keyword(s):  
Cell Surface ◽  
Chlamydomonas Reinhardtii ◽  
Surface Display ◽  
Cell Surface Display ◽  
Display System ◽  
A Cell ◽  
Cell Surface Display System

scholarly journals Fluctuating light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM

Plant Methods ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Dominik Schneider ◽  
Laura S. Lopez ◽  
Meng Li ◽  
Joseph D. Crawford ◽  
Helmut Kirchhoff ◽  
...  
Keyword(s):  
Data Analysis ◽  
Low Cost ◽  
Growth Conditions ◽  
Research Field ◽  
Constant Light ◽  
Plant Phenotyping ◽  
Natural Light ◽  
Light Conditions ◽  
Fluctuating Light ◽  
Science Labs

Abstract Background Over the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field. Results We show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup. Conclusions With material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.

scholarly journals Development of an automatic visual grading system for grafting seedlings

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668626 ◽  
Author(s):  
Subo Tian ◽  
Zifan Wang ◽  
Jifeng Yang ◽  
Zichen Huang ◽  
Ruili Wang ◽  
...  
Keyword(s):  
Image Processing ◽  
Computer Vision ◽  
Grading System ◽  
Natural Light ◽  
Maximum Frequency ◽  
Light Conditions ◽  
Visual Grading ◽  
Key Technology ◽  
Background Light ◽  
Blue Background

In this study, a visual grading system of vegetable grafting machine was developed. The study described key technology of visual grading system of vegetable grafting machine. First, the contrasting experiment was conducted between acquired images under blue background light and natural light conditions, with the blue background light chosen as lighting source. The Visual C++ platform with open-source computer vision library (Open CV) was used for the image processing. Subsequently, maximum frequency of total number of 0-valued pixels was predicted and used to extract the measurements of scion and rootstock stem diameters. Finally, the developed integrated visual grading system was experimented with 100 scions and rootstock seedlings. The results showed that success rate of grading reached up to 98%. This shows that selection and grading of scion and rootstock could be fully automated with this developed visual grading system. Hence, this technology would be greatly helpful for improving the grading accuracy and efficiency.

Studies on reflexion of light from silvery surfaces of fishes, with special reference to the bleak, Alburnus alburnus

1965 ◽  
Vol 45 (3) ◽  
pp. 683-703 ◽  
Author(s):  
E. J. Denton ◽  
J. A. C. Nicol
Keyword(s):  
Special Reference ◽  
Aquatic Environment ◽  
The Body ◽  
Natural Light ◽  
Light Conditions ◽  
Trachurus Trachurus ◽  
Reflecting Surfaces ◽  
Bleak Alburnus Alburnus ◽  
Different Parts

The problem of how a fish can make itself invisible in the natural light-conditions in an aquatic environment is discussed with particular reference to the silvery surfaces of fish.In fish which we have examined, the silvery surfaces are of two types: (1) an argenteum which consists of long thin crystals of guanine whose reflecting surfaces are approximately parallel with the surface of the fish; (2) layers of guanine crystals lying either on the inner surfaces of the scales or in the subdermis—these crystals are not, in general, orientated with their reflecting surfaces parallel with the surfaces of the fish, and are much broader than those of the argenteum.Methods are described by which the orientation of the crystal planes with respect to the planes of the scales on which they lie can be determined.The orientation of the crystals of type 2 in different parts of the body is described for the horse mackerel, Trachurus trachurus (L.), and for the bleak, Alburnus alburnus (L.).For the bleak it is shown that although the planes of the crystals are often very much inclined with respect to the planes of the scales, the long axes of the crystals are always approximately parallel with the planes of scales. The inclination of the crystals, therefore, is away from the scales across their short axes.Measurements of the light transmitted by silvery scales of the bleak show that they reflect light strongly when this falls obliquely on the crystals which they contain and that they are most transparent to light which strikes the scales in a direction perpendicular to the reflecting planes of the crystals.

scholarly journals Fluctuating light experiments and semi-automated plant phenotyping enabled by self-built growth racks and simple upgrades to the IMAGING-PAM

2019 ◽  
Author(s):  
Dominik Schneider ◽  
Laura S. Lopez ◽  
Meng Li ◽  
Joseph D. Crawford ◽  
Helmut Kirchhoff ◽  
...  
Keyword(s):  
Data Analysis ◽  
Low Cost ◽  
Growth Conditions ◽  
Research Field ◽  
Constant Light ◽  
Plant Phenotyping ◽  
Natural Light ◽  
Light Conditions ◽  
Fluctuating Light ◽  
Science Labs

AbstractBackgroundOver the last years, several plant science labs have started to employ fluctuating growth light conditions to simulate natural light regimes more closely. Many plant mutants reveal quantifiable effects under fluctuating light despite being indistinguishable from wild-type plants under standard constant light. Moreover, many subtle plant phenotypes become intensified and thus can be studied in more detail. This observation has caused a paradigm shift within the photosynthesis research community and an increasing number of scientists are interested in using fluctuating light growth conditions. However, high installation costs for commercial controllable LED setups as well as costly phenotyping equipment can make it hard for small academic groups to compete in this emerging field.ResultsWe show a simple do-it-yourself approach to enable fluctuating light growth experiments. Our results using previously published fluctuating light sensitive mutants, stn7 and pgr5, confirm that our low-cost setup yields similar results as top-prized commercial growth regimes. Moreover, we show how we increased the throughput of our Walz IMAGING-PAM, also found in many other departments around the world. We have designed a Python and R-based open source toolkit that allows for semi-automated sample segmentation and data analysis thereby reducing the processing bottleneck of large experimental datasets. We provide detailed instructions on how to build and functionally test each setup.ConclusionsWith material costs well below USD$1000, it is possible to setup a fluctuating light rack including a constant light control shelf for comparison. This allows more scientists to perform experiments closer to natural light conditions and contribute to an emerging research field. A small addition to the IMAGING-PAM hardware not only increases sample throughput but also enables larger-scale plant phenotyping with automated data analysis.

Evidence that nano-TiO2 induces acute cytotoxicity to the agronomically beneficial nitrogen fixing bacteria Sinorhizobium meliloti

2021 ◽  
Author(s):  
Jieping Wang ◽  
Yu Jia ◽  
Joann K. Whalen ◽  
Heather McShane ◽  
Brian T. Driscoll ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Sinorhizobium Meliloti ◽  
Ultra Violet ◽  
Oxygen Species ◽  
Light Conditions ◽  
Nitrogen Fixing ◽  
Nano Tio2 ◽  
Aqueous Dispersions ◽  
Acute Cytotoxicity ◽  
Meliloti Strain

When nano-sized titanium dioxide (nano-TiO2) absorbs ultra-violet (UV-A) radiation, it produces reactive oxygen species that can be toxic to bacteria. We used the agronomically beneficial nitrogen-fixing bacterium Sinorhizobium meliloti strain 1021 as a model microorganism to detect nano-TiO2 toxicity. S. meliloti was exposed to aqueous dispersions of micrometer-sized TiO2 (micron-TiO2, 44 μm) or nanometer-sized TiO2 (nano-TiO2, 21 nm) at nominal concentrations of 0, 100, 300, 600, 900 and 1800 mg TiO2/L. There were fewer viable S. meliloti after exposure to nano-TiO2 under dark and UV-A light conditions. Nano-TiO2 was more toxic to S. meliloti with UV-A irradiation (100% mortality at 100 mg TiO2/L) than under dark conditions (100% mortality at 900 mg TiO2/L). Micron-TiO2 concentrations less than 300 mg TiO2/L had no effect on the S. meliloti viability under dark or UV-A light conditions. Exposure to 600 mg/L or more of micron-TiO2 under UV-A light could also photo-kill S. meliloti cells (100% mortality). Further study is needed to ascertain whether nano-TiO2 interferes with the growth of N2-fixing microorganisms in realistic agricultural environments.

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