scholarly journals New modular assays for the quantitative study of skylight navigation in flying flies

2019 ◽  
Author(s):  
Thomas Mathejczyk ◽  
Mathias F. Wernet
Keyword(s):  
Quantitative Study ◽  
Controlled Environment ◽  
Light Sources ◽  
Software Components ◽  
Uniform Field ◽  
Visual Behaviors ◽  
3D Printed ◽  
Computer Controlled ◽  
Visual Artifacts ◽  
Filter Wheel

SummaryThe quantitative study of visual behaviors using virtual flight arenas is complicated by the fact that an effective experimental setup needs to combine a rather complex set of custom-built mechanical, electronic, and software components. Assembling such an apparatus amounts to a major challenge when working in an environment without the support of a machine shop. Here we present detailed instructions for the assembly of virtual flight arenas optimized for Drosophila skylight navigation, which can easily be modified towards other uses. This system consists entirely of off-the-shelf parts and 3D-printed components, combining a modular flight arena designed to reduce visual artifacts, swappable high-power LED light sources, polarization filters on a computer-controlled rotating filter wheel, all placed within a temperature and humidity controlled environment. Using this new assay, we show that individual flies choose arbitrary headings when flying under a uniform field of linear polarization. Furthermore, flies adjust their heading to both sudden and continuous changes in filter orientation and can keep their chosen heading for several minutes. Finally, flies show the tendency to maintain headings even after interruption with an unpolarized stimulus. Taken together, these findings demonstrate the usefulness of these assays for the study of skylight navigation in flies.

scholarly journals How to Validate in silico Deployment of Coronary Stents: Strategies and Limitations in the Choice of Comparator

2021 ◽  
Vol 3 ◽  
Author(s):  
Francesca Berti ◽  
Luca Antonini ◽  
Gianluca Poletti ◽  
Constantino Fiuza ◽  
Ted J. Vaughan ◽  
...  
Keyword(s):  
Numerical Model ◽  
Medical Devices ◽  
In Silico ◽  
Computational Models ◽  
Ad Hoc ◽  
Coronary Stent ◽  
Controlled Environment ◽  
Stent Deployment ◽  
Validation Plan ◽  
3D Printed

This study aims at proposing and discussing useful indications to all those who need to validate a numerical model of coronary stent deployment. The proof of the reliability of a numerical model is becoming of paramount importance in the era of in silico trials. Recently, the ASME V&V Standard Committee for medical devices prepared the V&V 40 standard document that provides a framework that guides users in establishing and assessing the relevance and adequacy of verification and validation activities performed for proving the credibility of models. To the knowledge of the authors, only a few examples of the application of the V&V 40 framework to medical devices are available in the literature, but none about stents. Specifically, in this study, the authors wish to emphasize the choice of a relevant set of experimental activities to provide data for the validation of computational models aiming to predict coronary stent deployment. Attention is focused on the use of ad hoc 3D-printed mock vessels in the validation plan, which could allow evaluating aspects of clinical relevance in a representative but controlled environment.

scholarly journals Biochemical and Gene Expression Involved in Red Blush Color Development in ‘Ambrosia’ Apple

2019 ◽  
Vol 144 (3) ◽  
pp. 164-171
Author(s):  
Peter M.A. Toivonen ◽  
Jared Stoochnoff ◽  
Kevin Usher ◽  
Changwen Lu ◽  
Paul A. Wiersma ◽  
...  
Keyword(s):  
Gene Expression ◽  
Color Space ◽  
Skin Surface ◽  
Ultraviolet B ◽  
Controlled Environment ◽  
Light Sources ◽  
Color Development ◽  
Primary Driver ◽  
Uvb Exposure ◽  
Environment Chamber

The market value of the apple (Malus ×domestica Borkh.) cultivar Ambrosia is closely linked to the characteristic blush on the skin surface. For ‘Ambrosia’ orchards that produce consistently low levels of surface blush, the implementation of reflective rowcovering has improved surface coloration, but the reflected wavebands responsible for this enhanced color production have not been confirmed. This study consisted of two separate experiments: one conducted in the field to confirm reflective rowcovering efficacy and the other in a controlled environment cabinet to determine which waveband was enhancing red blush production. The red blush production in orchards with and without reflective rowcovering was then directly compared with the red blush produced on the surface of apples that were poorly colored at harvest and then exposed to visible, fluorescent, ultraviolet A (UVA), or ultraviolet B (UVB) light sources within the controlled environment chamber. Consequent analysis of the red blush color within the Commission Internationale de l’Eclairage a* and b* color space was conducted to evaluate the quality of the red blush pigment under each treatment in the field and the controlled environment chamber. The analysis revealed that the red blush that developed on apples from the reflective rowcover treatment most closely matched the red blush that developed in response to UVB exposure in the controlled environment cabinet. Further analysis of gene expression and anthocyanin contents in the ‘Ambrosia’ apples support the hypothesis that the primary driver for the characteristic red blush development, when reflective rowcovers are used, is increased exposure to UVB light.

scholarly journals Different Textile Materials as Light Shaping Attachments in Studio Photography and Their Influence on Colour Reproduction

Tekstilec ◽  
2021 ◽  
Vol 64 (1) ◽  
pp. 4-15
Author(s):  
Veronika Štampfl ◽  
◽  
Klemen Možina ◽  
Jure Ahtik ◽  
◽  
...  
Keyword(s):  
Controlled Environment ◽  
Light Sources ◽  
Diffuse Light ◽  
High Quality ◽  
Textile Materials ◽  
Different Types

The research focuses on the quality of colour reproduction when using different light sources, often used to illuminate scenes in a photo studio, and different types of fabrics as lighting shapers. With the latter, the light can be converted into softer and more diffuse light, but the properties of the fabrics used affect the colour impression and thus the quality of the reproduced colours. This was evaluated by analysing the colour differ¬ences which were calculated from the colorimetric values of the colour patches of the X-Rite ColorChecker Passport test chart. Test chart was photographed in a controlled environment and illuminated with different combinations of light sources and tested fabrics. The results confirmed that not all combinations of variables are suitable for use if the goal of the photograph is to achieve high quality colour reproduction.

scholarly journals TetrODrive: An open-source microdrive for combined electrophysiology and optophysiology

2020 ◽  
Author(s):  
Marcel Brosch ◽  
Alisa Vlasenko ◽  
Frank W. Ohl ◽  
Michael T. Lippert
Keyword(s):  
Signal To Noise Ratio ◽  
Cell Types ◽  
High Signal ◽  
Light Sources ◽  
3D Printer ◽  
Optogenetic Stimulation ◽  
Open Design ◽  
Reward Prediction ◽  
3D Printed ◽  
The Brain

AbstractObjectiveIn tetrode recordings, the cell types of the recorded units are difficult to determine based on electrophysiological characteristics alone. Optotagging, the use of optogenetic stimulation at the tip of electrodes to elicit spikes from genetically identified cells, is a method to overcome this challenge. However, recording from many different cells requires advancing electrodes and light sources slowly through the brain with a microdrive. Existing designs suffer from a number of drawbacks, such as limited stability and precision, high cost, complex assembly, or excessive size and weight.ApproachWe designed TetrODrive as a microdrive that can be 3D printed on an inexpensive desktop resin printer and has minimal parts, assembly time, and cost. The microdrive can be assembled in 15 minutes and the price for all materials, including the 3D printer, is lower than a single commercial microdrive. To maximize recording stability, we mechanically decoupled the drive mechanism from the electrical and optical connectors.Main resultsThe developed microdrive is small and light enough to be carried effortlessly by a mouse. It provides high signal-to-noise ratio recordings from optotagged units, even across recording sessions. Owing to its moveable optical fiber, our microdrive can also be used for fiber photometry. We evaluated our microdrive by recording single units and calcium signals in the ventral tegmental area (VTA) of mice and confirmed cell identity via optotagging. Thereby we found units not following the classical reward prediction error model.SignificanceTetrODrive is a tiny, lightweight, and affordable microdrive for optophysiology in mice. Its open design, price, and built-in characteristics can significantly expand the use of microdrives in mice.

scholarly journals Photosynthetic efficiency, growth and secondary metabolism of common buckwheat (Fagopyrum esculentum Moench) in different controlled-environment production systems

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Marta Hornyák ◽  
Michał Dziurka ◽  
Monika Kula-Maximenko ◽  
Jakub Pastuszak ◽  
Anna Szczerba ◽  
...  
Keyword(s):  
Secondary Metabolism ◽  
Production Systems ◽  
Soluble Carbohydrates ◽  
Controlled Environment ◽  
Light Sources ◽  
Common Buckwheat ◽  
Light Emitting ◽  
Led Light ◽  
Plant Cultivation ◽  
Fagopyrum Esculentum Moench

AbstractLight-emitting diodes (LEDs) and high-pressure sodium lamps (HPS) are among the most commonly used light sources for plant cultivation. The objective of this study was to evaluate the effect of two controlled-environment production systems differing in light sources on growth, photosynthetic activity, and secondary metabolism of common buckwheat. We hypothesized that LED light with the majority of red and blue waves would increase physiological and biochemical parameters compared to sunlight supplemented with HPS lamps. The experiment was performed in a phytotronic chamber (LEDs) and in a greenhouse (solar radiation supplemented with HPS lamps as a control). The effects were analyzed at the flowering phase with biometric measurements, leaf chlorophyll index, the kinetics of chlorophyll a fluorescence, content of soluble carbohydrates and phenolics in the leaves. Applied LED light decreased the biomass but stimulated the production of phenolics compared to control plants. In control plants, a positive correlation between flavonoid content and energy dissipation from photosystem II (DIo/CSm) was found, while in plants under LEDs total pool of phenolic content correlated with this parameter and the quantum yield of electron transport (φ Ro and ψ Ro) was lower than that of the control, probably affecting buckwheat biomass.

scholarly journals Effects of artificial light sources on growth and phytochemicals content in green oak lettuce

2020 ◽  
Vol 38 (2) ◽  
pp. 204-210
Author(s):  
Nursalmeeyah Etae ◽  
Yarodah Wamae ◽  
Weeraya Khummueng ◽  
Tanyarath Utaipan ◽  
Eaknarin Ruangrak
Keyword(s):  
Energy Saving ◽  
Flux Density ◽  
Dry Mass ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Controlled Environment ◽  
Artificial Light ◽  
Light Sources ◽  
Vegetable Production ◽  
Artificial Lighting

ABSTRACT The artificial light source is one of the most important factors in a controlled environment for vegetable production. It could provide new opportunities to improve growth and increase phytochemicals content in vegetables. Therefore, this study focused on the effects of artificial light sources on growth and phytochemicals in green oak lettuce (Lactuca sativa). The plants were grown under growth chamber with three artificial light sources, namely bar-LED (the 1:1:1 ratio of blue 460 nm : red 630 nm : red 660 nm), bulb-LED (the 2:1:1 ratio of blue 460 nm : red 630 nm : red 660 nm), and fluorescent lamp (FL) (the wavelength range 380-700 nm) for 4 weeks. The quality of bar-LED light was better than either bulb-LED or FL, when assessed by the parameters of photosynthetically active radiation (PAR), photosynthetic photon flux density (PPFD, 400-700 nm), PPFD-B (blue, 400-500 nm), PPFD-R (red, 600-700 nm), the yield photon flux density (YPFD), and the color of red. However, shoot and root (fresh and dry mass), leaf area, leaf number, and shoot/root ratio did not significantly differ between plants grown under bar-LED and bulb-LED, but they were significantly higher than plants grown under FL. Bulb-LED and bar-LED induced larger dry mass of the plants than FL. The dry mass per mole of artificial lighting was highest in plants grown under bar-LED. On the other hand, the fresh mass per mole of artificial lighting was highest in plants grown under bulb-LED. As regards power consumption, bar-LED provided the lowest consumption with 44.4% energy saving over the FL. Total phenolic content, 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenylpicrylhydrazyl (DPPH) activities were highest in plants grown under bar-LED. FL lighting gave the least contents of chlorophyll a and chlorophyll a + b. However, chlorophyll b and carotenoid contents did not significantly differ among the treatments. Thus, the results suggested that bar-LED has the potential to improve energy saving, and both growth and phytochemicals content of green oak lettuce grown in a controlled environment of vegetable production.

Retrieving reusable software components by polymorphic type

1991 ◽  
Vol 1 (2) ◽  
pp. 191-211 ◽  
Author(s):  
Colin Runciman ◽  
Ian Toyn
Keyword(s):  
Quantitative Study ◽  
Retrieval System ◽  
Software Components ◽  
Reusable Software ◽  
Flexible System ◽  
Software Libraries ◽  
Free Variables ◽  
Polymorphic Type

AbstractPolymorphic types are labels classifying both (a) defined components in a library and (b) contexts of free variables in partially written programs. It is proposed to help programmers make better use of software libraries by providing a system that, given (b), identifies candidates from (a) with matching types. Assuming at first that matching means unifying (i.e. having a common instance), efficient ways of implementing such a retrieval system are discussed and its likely effectiveness based on a quantitative study of currently available libraries is indicated. The applicative instance relation between types, which captures some intuitions about generalization/specialization is then introduced, and its use as the basis of a more flexible system is discussed.

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