Image based phenotyping during winter: a powerful tool to assess wheat genetic variation in growth response to temperature

2015 ◽  
Vol 42 (4) ◽  
pp. 387 ◽  
Author(s):  
Christoph Grieder ◽  
Andreas Hund ◽  
Achim Walter
Keyword(s):  
Growth Response ◽  
Digital Camera ◽  
Canopy Cover ◽  
Triticum Aestivum L ◽  
Base Temperature ◽  
Strong Positive Correlation ◽  
Measurement Interval ◽  
Relative Growth Rates ◽  
Additional Information ◽  
Large Populations

Having a strong effect on plant growth, temperature adaption has become a major breeding aim. Due to a lack of efficient methods, we developed an image-based approach to characterise genotypes for their temperature behaviour in the field. Twenty-nine winter wheat (Triticum aestivum L.) genotypes were continuously monitored at 3-day intervals on a plot basis during early growth from November to March using a modified digital camera. Canopy cover (CC) was determined by segmentation of leaves in calibrated images. Relative growth rates (RGR) of CC were then calculated for each measurement interval and related to the respective temperature. Also, classical traits used in plant breeding were assessed. Measurements of CC at single dates were highly repeatable with respect to genotype. For the tested range of temperatures (0−7°C), a linear relation between RGR and temperature was observed. Genotypes differed for base temperature and increase in RGR with rising temperature, these two traits showing a strong positive correlation with each other but being independent of CC at a single date. Our simple approach is suitable to screen large populations for differences in growth response to environmental stimuli. Furthermore, the derived parameters reveal additional information that cannot be assessed by usual measurements of static size.

Electron Holography and Digital Imaging for Analysis of Nanostructured Materials

1998 ◽  
Vol 4 (S2) ◽  
pp. 750-751
Author(s):  
L. F. Allard ◽  
E. Voelkl ◽  
A. K. Datye ◽  
A. H. Carim
Keyword(s):  
Nanostructured Materials ◽  
Digital Camera ◽  
Digital Processing ◽  
Quantitative Information ◽  
Electron Holography ◽  
Additional Information ◽  
Camera Systems ◽  
Phase Images ◽  
Ultra Fine Particle ◽  
Rapid Processing

Many nanostructured materials are formed from powder precursors having ultra-fine particle sizes. Techniques of electron microscopy have proven invaluable for characterizing the structure of the precursor materials in order to better understand the fundamental processes that govern consolidation of the materials into the final nanophase structures. In recent years, the rapidly developing technique of electron holography has increasingly been applied for characterizing particle morphologies. The advent of the modern field emission microscope, which offers beam coherency sufficient to produce high contrast interference fringes for optimum hologram formation, and especially the availability of digital camera systems for hologram acquisition and rapid processing have both combined to bring electron holography to the forefront of techniques for characterization of nanostructured materials.Electron holograms typically yield phase images that can give quantitative information on crystal morphologies, but much additional information can result from digital processing of holograms.

scholarly journals Opportunistic Germination Behaviour of Gypsophila (Caryophyllaceae) in Two Priority Habitats from Semi-arid Mediterranean Steppes

2011 ◽  
Vol 39 (1) ◽  
pp. 18 ◽  
Author(s):  
Felix MORUNO ◽  
Pilar SORIANO ◽  
Oscar VICENTE ◽  
Monica BOSCAIU ◽  
Elena ESTRELLES
Keyword(s):  
Seed Germination ◽  
Climatic Conditions ◽  
Thermal Time ◽  
Distribution Area ◽  
Base Temperature ◽  
Additional Information ◽  
High Viability ◽  
Germination Behaviour ◽  
Alternating Temperature

Gypsophila tomentosa and G. struthium are closely related species, characteristic of two European priority habitats, salt and gypsum inland steppes, respectively. Germination strategies of the two taxa were investigated in plants from two nearby populations, growing under the same climatic conditions but on different types of soil, and belonging to different plant communities. Their germination patterns were studied at five constant temperatures in darkness: 5oC, 10oC, 15oC, 20oC and 25oC, and the base temperature and the thermal time requirement were calculated. As the distribution area of both species is subjected to a Mediterranean continental climate with significant differences between day and night, the possible preferences for an alternating temperature regime (25/10oC) were contrasted, as well as the influence of cold stratification and freezing. The effects on seed germination of light at constant 20oC and a 12/12 h photoperiod were also compared in the two species. The main conclusions of the work are the similarity of behaviour of both species, with an absence of seed dormancy, their opportunistic germination strategy, and water availability as the principal limitation to seed germination and plant establishment. The base temperature and thermal time indicate higher competitiveness of G. struthium at low temperatures, but seed germination of G. tomentosa is the most efficient at temperatures higher than 13.3oC. Optimal temperature and illumination conditions for nursery propagation depend on the species. The high viability of seeds observed after freezing prove the orthodox character of these seeds, providing additional information for long term seed conservation procedures.

A Photographic Flux Mapping Method for Concentrating Solar Collectors and Receivers

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Clifford K. Ho ◽  
Siri S. Khalsa
Keyword(s):  
Digital Camera ◽  
Mapping Method ◽  
Test Facility ◽  
The Novel ◽  
Error Sources ◽  
Additional Information ◽  
Direct Normal Irradiance ◽  
Beam Characterization ◽  
Pixel Value ◽  
Relative Errors

A new method is described to determine irradiance distributions on receivers and targets from heliostats or other collectors for concentrating solar power applications. The method uses a digital camera, and, unlike previous beam characterization systems, it does not require additional sensors, calorimeters, or flux gauges on the receiver or target. In addition, spillage can exist and can also be measured (the beam does not need to be contained within the target). The only additional information required besides the images recorded from the digital camera is the direct normal irradiance and the reflectivity of the receiver. Methods are described to calculate either an average reflectivity or a reflectivity distribution for the receiver using the digital camera. The novel feature of this new photographic flux (PHLUX) mapping method is the use of recorded images of the sun to scale both the magnitude of each pixel value and the subtended angle of each pixel. A test was performed to evaluate the PHLUX method using a heliostat beam on the central receiver tower at the National Solar Thermal Test Facility in Albuquerque, NM. Results showed that the PHLUX method was capable of producing an accurate flux map of the heliostat beam on a Lambertian surface with a relative error in the peak flux of ∼2% when the filter attenuation factors and effective receiver reflectivity were well characterized. Total relative errors associated with the measured irradiance using the PHLUX method can be up to 20%–40%, depending on various error sources identified in the paper, namely, uncertainty in receiver reflectivity and filter attenuation.

Wheat Spike Temperature in Relation to Base Temperature for Grain Filling Duration

1991 ◽  
Vol 71 (1) ◽  
pp. 63-69 ◽  
Author(s):  
S. Pararajasingham ◽  
L. A. Hunt
Keyword(s):  
Triticum Aestivum ◽  
Air Temperature ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
The Other ◽  
Base Temperature ◽  
Infrared Thermometer ◽  
Grain Filling Duration ◽  
Set Up ◽  
Wheat Spike

Estimates of the base temperature for grain filling duration of wheat (Triticum aestivum L.) differ between outdoor and indoor studies. This study was set up to determine whether this difference could be attributed to variation in spike-air temperature differentials. Spike and/or spikelet temperatures were determined in wheat grown outdoors as well as indoors. Spike temperature, measured with an infrared thermometer, of wheat grown outdoors with adequate water supply was 1.5 °C greater than air temperature while spikelet temperature measured with a thermocouple closely approximated air temperature. In indoor grown wheat, on the other hand, regardless of the magnitude of air temperature, spikelet temperature was found to be 3–4 °C above that of air when lights were on. Estimating the base temperature for grain filling duration with data from a previous indoor study, with compensation for the 3–4 °C increase in spikelet temperature, resulted in 8.8 °C base temperature for grain filling duration, comparable to that obtained in outdoor studies. Differences between outdoor and indoor studies may thus reflect spike-air temperature differentials. Estimation of the base temperature for grain filling with air temperature appears appropriate for outdoor studies. Key words: Triticum aestivum (L.), base temperature, grain filling duration, wheat

scholarly journals On-Sun Evaluation of the PHLUX Method for Heliostat Beam Characterization

2016 ◽  
Author(s):  
Julius Yellowhair ◽  
Clifford K. Ho
Keyword(s):  
Focal Length ◽  
Digital Camera ◽  
Total Power ◽  
Neutral Density ◽  
Additional Information ◽  
Direct Normal Irradiance ◽  
Beam Characterization ◽  
Peak Flux ◽  
And Performance ◽  
Solar Field

Flux distributions from solar field collectors are typically evaluated using a beam characterization system, which consists of a digital camera with neutral density filters, flux gauge or calorimeter, and water-cooled Lambertian target panel. The pixels in camera image of the flux distribution are scaled by the flux peak value measured with the flux gauge or the total power value measured with the calorimeter. An alternative method, called PHLUX developed at Sandia National Laboratories, can serve the same purpose using a digital camera but without auxiliary instrumentation. The only additional information required besides the digital images recorded from the camera are the direct normal irradiance, an image of the sun using the same camera, and the reflectivity of the receiver or target panel surface. The PHLUX method was evaluated using two digital cameras (Nikon D90 and D3300) at different flux levels on a target panel. The performances of the two cameras were compared to each other and to measurements from a Kendall radiometer. For consistency in comparison of the two cameras, the same focal length lenses and same number of neutral density filters were used. Other camera settings (e.g., shutter speed, f-stop, etc.) were set based on the aperture size and performance of the cameras. The Nikon D3300 has twice the number of pixels as the D90. D3300 provided higher resolution, however, due to the smaller pixel sizes the images were noisier, and the D90 with larger pixels had better response to low light levels. The noise in the D3300, if not corrected, could result in gross overestimation of the irradiance calculations. After corrections to the D3300 flux images, the PHLUX results from the two cameras showed they agreed to within 8% for a peak flux level of 1000 suns on the target, and less than 10% error in the peak flux when compared to the Kendall radiometer.

scholarly journals Updated catalogue of bony fishes observed in deep waters at Isla del Coco National Park and Las Gemelas Seamount, Costa Rica (Eastern Tropical Pacific)

2018 ◽  
Vol 66 (5) ◽  
pp. 1 ◽  
Author(s):  
Astrid Sánchez-Jiménez ◽  
Beatriz Naranjo-Elizondo ◽  
Alexander Rodríguez-Arrieta ◽  
Andrés J. Quesada ◽  
Shmulik Blum ◽  
...  
Keyword(s):  
Costa Rica ◽  
National Park ◽  
Digital Camera ◽  
Systematic Research ◽  
High Definition ◽  
Remotely Operated Vehicle ◽  
Additional Information ◽  
Deep Waters ◽  
Bony Fishes ◽  
Management Area

From 2006 to date the submersible DeepSee has been used to study the deep waters in and around Isla del Coco National Park, Costa Rica. Over these years, images and samples have been collected at depths between 50 and 450 m. Here we present a catalogue of bony fishes recorded by the submersible in deep waters of Isla del Coco, 500 km south-southwest of mainland Costa Rica, and at Las Gemelas Seamount within the designated Seamounts Management Area, 50 km southwest of Isla del Coco. A database with video-images of bony fishes was created from videos taken by the submersible’s high-definition digital camera from 2006 to 2015. Additional information on the distribution of fishes was obtained from 11 dives (24.3 hrs) using the remotely operated vehicle Hela at Las Gemelas Seamount during February 2012. Images of bony fishes were obtained during 376 dives (365 DeepSee dives plus 11 Hela dives) in 18 different locations, and here we report on a total of 85 taxa (i.e. putative species). In this catalogue we present images that are the first color photographs published for some species. In other cases, identifications were possible only to the level of genus (11), family (5) or order (1); hence the information is presented in terms of putative taxa. Four new records are reported for Isla del Coco: Leptenchelys vermiformis (Ophichthidae), Hyporthodus mystacinus (Serranidae), Kathetostoma averruncus (Uranoscopidae), and Symphurus diabolicus (Cynoglossidae). Depth ranges of twenty-six species are expanded beyond previously published records; three were observed in shallower water, twenty-two in deeper water and one was observed both shallower and deeper than in previous reports. As might be expected, increased bottom time with the submersible resulted in additions to the list of documented species. This highlights the importance of maintaining systematic research efforts in the deep waters around Isla del Coco, both for scientific purposes as well as conservation.

scholarly journals Anticipating the curve: can online symptom-based data reflect COVID-19 case activity in Ontario, Canada?

2021 ◽  
Author(s):  
Arjuna S. Maharaj ◽  
Jennifer Parker ◽  
Jessica P. Hopkins ◽  
Effie Gournis ◽  
Isaac I. Bogoch ◽  
...  
Keyword(s):  
Syndromic Surveillance ◽  
Low Cost ◽  
Diagnostic Testing ◽  
Primary Objective ◽  
Surveillance Systems ◽  
Strong Positive Correlation ◽  
Additional Information ◽  
Digital Surveillance ◽  
Percent Positivity ◽  
And Control

ABSTRACTBackgroundLimitations in laboratory diagnostic capacity and reporting delays have hampered efforts to mitigate and control the ongoing COVID-19 pandemic globally. Syndromic surveillance of COVID-19 is an important public health tool that can help detect outbreaks, mobilize a rapid response, and thereby reduce morbidity and mortality. The primary objective of this study was to determine whether syndromic surveillance through self-reported COVID-19 symptoms could be a timely proxy for laboratory-confirmed case trends in the Canadian province of Ontario.MethodsWe retrospectively analyzed self-reported symptoms data collected using an online tool – Outbreaks Near Me (ONM) – from April 20th to Oct 11th, 2020 in Ontario, Canada. We estimated the correlation coefficient between the weekly proportion of respondents reporting a COVID-like illness (CLI) to both the weekly number of PCR-confirmed COVID-19 cases and the percent positivity in the same period for the same week and with a one-week lag.ResultsThere were 314,686 responses from 188,783 unique respondents to the ONM symptom survey. Respondents were more likely to be female and be in the 40-59 age demographic compared to the Ontario general population. There was a strong positive correlation between the weekly number of reported cases in Ontario and the percent of respondents reporting CLI each week (r = 0.89, p <0.01) and with a one-week lag (r = 0.89, p <0.01).InterpretationWe demonstrate a strong positive and significant correlation (r = 0.89, p <0.01) between percent of self-reported COVID-like illness and the subsequent week’s COVID-19 cases reported, highlighting that a rise in CLI may precede official statistics by at least 1 week. This demonstrates the utility of syndromic surveillance in predicting near-future disease activity. Digital surveillance systems are low-cost tools that may help measure the burden of COVID-19 in a community if there is under-detection of cases through conventional laboratory diagnostic testing. This additional information can be used to guide a healthcare response and policy decisions.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Laser Pulse ◽  
Digital Camera ◽  
Florida Keys ◽  
Benthic Habitat ◽  
Seagrass Beds ◽  
Additional Information ◽  
Monitoring Tools ◽  
Sonar Systems ◽  
Satellite Sensors ◽  
Remote Mapping

For ecologists and managers of seagrass systems, the spatial context provided by remote sensing has proven to be an important complement to in situ assessments and measurements. The spatial extent of seagrass beds has been mapped most commonly with conventional aerial photography. Additional remote mapping and monitoring tools applied to seagrass studies include optical satellite sensors, airborne multispectral scanners, underwater video cameras, and towed sonar systems. An additional tool that shows much promise is airborne, waveform-resolving lidar (light detection and ranging). Now used routinely for high-resolution bathymetric and topographic surveys, lidar systems operate by emitting a laser pulse, then measuring its two-way travel time from the plane to reflecting surface(s) below, then back to the detector co-located with the laser transmitter. Using a novel, waveformresolving lidar system developed at NASA — the Experimental Advanced Airborne Research Lidar (EAARL) — we are investigating the possibility of using the additional information contained in the returned laser pulse (waveform) for the purposes of benthic habitat mapping. Preliminary analyses indicate that seagrass beds can potentially be delineated on the basis of apparent bathymetry, returned waveform shape and amplitude, and (horizontal) spatial texture. A complete set of georectified digital camera imagery is also collected during each EAARL overflight and can aid in mapping efforts. Illustrative examples are shown from seagrass beds in the turbid waters of Tampa Bay and the relatively clear waters of the Florida Keys.

EXPRESSION OF VERNALIZATION GENES IN NEAR-ISOGENIC WHEAT LINES: METHODS OF VERNALIZATION

1979 ◽  
Vol 21 (3) ◽  
pp. 429-434 ◽  
Author(s):  
P. A. Salisbury ◽  
G. J. Berry ◽  
G. M. Halloran
Keyword(s):  
Reproductive Development ◽  
Triticum Aestivum L ◽  
Development Rate ◽  
Strong Positive Correlation ◽  
Near Isogenic Lines ◽  
Spikelet Number ◽  
Threshold Response ◽  
Graded Response ◽  
Vernalization Genes ◽  
Wheat Lines

Four near isogenic lines of wheat (Triticum aestivum L. em Thell.) were given various combinations of vernalization as imbibed seed and as growing plants. The combinations were designed so that all treatments had the equivalent of four weeks at 4 °C. In terms of days to anthesis the lines reacted in three different ways to increases in the proportion of the vernalization treatment given to the growing plant. Two lines exhibited a threshold response, another showed a graded response, while the remaining line was unaffected by the method of vernalization. The treatments affected final leaf number differently, and the usually strong positive correlation with days to anthesis was not evident. Similarly there was no evidence of a relationship between days to anthesis and spikelet number. The rate of reproductive development of varieties vernalized as imbibed seed will not necessarily reflect their development rate when vernalized naturally in the field. Hence wheat breeders adapting varieties to particular environments by the use of vernalization genes should evaluate their action under appropriate field conditions.

Relative growth rates of two epiphytic lichens, Lobaria pulmonaria and Hypogymnia occidentalis, transplanted within and outside of Populus dripzones

Botany ◽  
2012 ◽  
Vol 90 (10) ◽  
pp. 954-965 ◽  
Author(s):  
Yngvar Gauslaa ◽  
Trevor Goward
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Picea Glauca ◽  
Canopy Cover ◽  
Tree Height ◽  
P Fertilization ◽  
Lobaria Pulmonaria ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Area Growth

Overstory Populus has been shown to facilitate establishment by cyano- and cephalolichens on conifer branches within its dripzone; though the mechanisms behind this “dripzone effect” have yet to be elucidated. Here we test the following hypotheses that throughfall from Populus: (i) elevates bark pH; (ii) increases relative growth rate in cephalolichens; and (iii) stimulates their growth through phosphorus (P) fertilization. In southern British Columbia we transplanted the cephalolichen Lobaria pulmonaria (L.) Hoffm. (promoted by dripzones) and the acidophytic chlorolichen Hypogymnia occidentalis L.H. Pike for 14 months to 26 pairs of similar-sized Picea glauca × engelmannii situated within and outside of Populus dripzones. Half of our transplants were fertilized with P. Bark pH was significantly higher on spruce branches within than outside dripzones. Relative growth rate in L. pulmonaria increased with bark pH and was slightly higher within dripzones than outside, consistent with a facilitating effect of Populus on the Lobarion community. By contrast, the addition of P decreased relative thallus area growth in L. pulmonaria and increased relative thallus area growth in H. occidentalis; though a stronger influence on growth could be attributed to variation in canopy cover and tree height. We conclude that cephalolichens in our study area are unlikely to be facilitated by P leached from Populus.

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