Automated Microscopy: Macro Language Controlling a Confocal Microscope and its External Illumination: Adaptation for Photosynthetic Organisms

AbstractPhotosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (throughTime Controlleroffered by Olympus orExperiment Designeroffered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with theCell⊕Findersoftware was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) theCell⊕Findersoftware with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser.Cell⊕Findercan be downloaded fromhttp://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity inSynechocystissp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light.

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Insufficient melanopic equivalent daylight illuminance in nursing home dementia units across seasons and gaze directions

Lighting Research and Technology ◽

10.1177/1477153521994539 ◽

2021 ◽

pp. 147715352199453

Author(s):

E Kolberg ◽

S Pallesen ◽

GJ Hjetland ◽

IH Nordhus ◽

E Thun ◽

...

Keyword(s):

Nursing Home ◽

Future Research ◽

Light Sources ◽

Physiological Effects ◽

Light Conditions ◽

Visual Responses ◽

Seasonal Differences ◽

Healthy Environment ◽

Nursing Home Patients

Adequate illumination plays an important part in providing a healthy environment for nursing home patients with dementia. With increasing awareness of non-visual responses to light, new approaches to quantifying illuminance have emerged. In the present study, we assessed the illuminance in nursing home dementia units in terms of melanopic equivalent daylight illuminance, a metric which aims to quantify the non-visual physiological effects of light by weighing irradiance according to non-visual photoreception. It is among the most comprehensive studies of light conditions conducted in dementia units in terms of melanopic equivalent daylight illuminance to date, and the first to elucidate seasonal differences in melanopic illumination. Light conditions were assessed in all 15 nursing homes with dedicated long-term dementia units in Bergen municipality (60.39°N), Norway, during summer and winter. Results indicated that seasonal differences and gaze direction had some impact on melanopic equivalent daylight illuminance, but most measurements still fell below even conservative recommendations across seasons. The findings indicate a need for additional light sources that can compensate for limited natural daylight in dementia units. The ubiquity of insufficient melanopic equivalent daylight illuminance in dementia units suggests a role for lighting interventions in future research seeking to improve entrainment, sleep and mental health of dementia unit residents.

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Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

Nuklearmedizin ◽

10.1055/s-0037-1620603 ◽

1977 ◽

Vol 16 (01) ◽

pp. 30-35 ◽

Cited By ~ 1

Author(s):

N. Agha ◽

R. B. R. Persson

Keyword(s):

Complex Formation ◽

Significant Influence ◽

Room Temperature ◽

Ph Value ◽

Maximum Activity ◽

Reduction Step ◽

Labelling Yield ◽

Different Temperatures ◽

Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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The problem of ballistic design of the space system Earth remote sensing in stable near-circular sun-synchronous orbits with long-term spacecraft lifetime

Informacionno-technologicheskij vestnik ◽

10.21499/2409-1650-2018-3-3-9 ◽

2018 ◽

pp. 3-9

Author(s):

V. M. Artyushenko ◽

D. Y. Vinogradov

Keyword(s):

Remote Sensing ◽

Target Function ◽

Normal Operation ◽

Space Systems ◽

Light Conditions ◽

Space System ◽

Earth Remote Sensing ◽

Synchronous Orbit ◽

Favorable Conditions

The article deals with the issues related to the problem of ballistic design of the space system of remote sensing of the Earth on stable near-circular solar-synchronous orbits with long-term existence of spacecraft. We propose a rational method of maintaining a solar-synchronous orbit in given light conditions with prolonged active lifetime of space systems. In solving this problem, the total time of normal operation of the system for a given period of operation, during which the most favorable conditions for the use of spacecraft are provided on the main parts of orbits, is taken as a target function.

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Long-Term Clinical Effects, Bioavailability, and Kinetics of Minoxidil in Relation to Renal Function

The Journal of Clinical Pharmacology ◽

10.1002/j.1552-4604.1978.tb01578.x ◽

1978 ◽

Vol 18 (10) ◽

pp. 500-508 ◽

Cited By ~ 17

Author(s):

DAVID T. LOWENTHAL ◽

GADDO ONESTI ◽

ROBERT MUTTERPERL ◽

MELTON APFRIME ◽

EDUARDO W. MARTINEZ ◽

...

Keyword(s):

Renal Function ◽

Clinical Effects ◽

Kinetics Of

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Phosphorus removal by apatite in horizontal flow constructed wetlands for small communities: pilot and full-scale evidence

Water Science & Technology ◽

10.2166/wst.2011.250 ◽

2011 ◽

Vol 63 (8) ◽

pp. 1629-1637 ◽

Cited By ~ 8

Author(s):

N. Harouiya ◽

S. Martin Rue ◽

S. Prost-Boucle ◽

A. Liénar ◽

D. Esser ◽

...

Keyword(s):

Constructed Wetlands ◽

Particle Surface ◽

Full Scale ◽

Retention Capacity ◽

Small Communities ◽

Lab Experiments ◽

Apatite Mineral ◽

Kinetics Of ◽

P Removal

Phosphorus (P) removals in constructed wetlands (CWs) have received particular attention in recent decades by using specific materials which promote adsorption/precipitation mechanisms. Recent studies have shown interest in using apatite materials to promote P precipitation onto the particle surface. As previous trials were mainly done by lab experiments, this present study aims to evaluate the real potential of apatites to remove P from wastewater in pilot units and a full-scale plant over a 2 year period. P retention kinetics of two qualities of apatites are presented and discussed. In this work apatite appears to have high retention capacity (>80% of P removal) and is still an interesting way for P removal in CWs for limiting the risk of eutrophication downstream of small communities. Nevertheless, the apatite quality appears to be of great importance for a reliable and long term P removal. The use of materials with low content of apatite mineral (40–50%) seems to be not economically relevant.

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Acclimation to changing light conditions of long-term shade-grown beech (Fagus sylvatica L.) seedlings of different geographic origins

Trees ◽

10.1007/pl00009719 ◽

1998 ◽

Vol 12 (6) ◽

pp. 326-333 ◽

Cited By ~ 8

Author(s):

R. Tognetti ◽

Gianfranco Minotta ◽

Simone Pinzauti ◽

Marco Michelozzi ◽

Marco Borghetti

Keyword(s):

Fagus Sylvatica ◽

Light Conditions ◽

Geographic Origins ◽

Fagus Sylvatica L ◽

Changing Light

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Generalized receptor law governs phototaxis in the phytoplanktonEuglena gracilis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1422922112 ◽

2015 ◽

Vol 112 (22) ◽

pp. 7045-7050 ◽

Cited By ~ 29

Author(s):

Andrea Giometto ◽

Florian Altermatt ◽

Amos Maritan ◽

Roman Stocker ◽

Andrea Rinaldo

Keyword(s):

Algal Blooms ◽

Nonlinear Response ◽

Temporal Dynamics ◽

Freshwater Ecosystems ◽

Trophic Levels ◽

Light Fields ◽

Light Sources ◽

Mathematical Framework ◽

Heterogeneous Environments ◽

Light Conditions

Phototaxis, the process through which motile organisms direct their swimming toward or away from light, is implicated in key ecological phenomena (including algal blooms and diel vertical migration) that shape the distribution, diversity, and productivity of phytoplankton and thus energy transfer to higher trophic levels in aquatic ecosystems. Phototaxis also finds important applications in biofuel reactors and microbiopropellers and is argued to serve as a benchmark for the study of biological invasions in heterogeneous environments owing to the ease of generating stochastic light fields. Despite its ecological and technological relevance, an experimentally tested, general theoretical model of phototaxis seems unavailable to date. Here, we present accurate measurements of the behavior of the algaEuglena graciliswhen exposed to controlled light fields. Analysis ofE. gracilis’ phototactic accumulation dynamics over a broad range of light intensities proves that the classic Keller–Segel mathematical framework for taxis provides an accurate description of both positive and negative phototaxis only when phototactic sensitivity is modeled by a generalized “receptor law,” a specific nonlinear response function to light intensity that drives algae toward beneficial light conditions and away from harmful ones. The proposed phototactic model captures the temporal dynamics of both cells’ accumulation toward light sources and their dispersion upon light cessation. The model could thus be of use in integrating models of vertical phytoplankton migrations in marine and freshwater ecosystems, and in the design of bioreactors.

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