A quantitative analysis of objective feather colour assessment: measurements in the lab are more reliable than in the field

The evolution of animal colouration is importantly driven by sexual selection operating on traits used to transmit information to rivals and potential mates, which therefore, have major impacts on fitness. Reflectance spectrometry has become a standard colour-measuring tool, especially after the discovery of tetrachromacy in birds and their ability to detect UV. Birds? plumage patterns may be invisible to humans, necessitating a reliable and objective way of assessing colouration not dependent on human vision. Plumage colouration measurements can be taken directly on live birds in the field or in the lab (e.g. on collected feathers). Therefore, it is essential to determine which sampling method yields more repeatable and reliable measures, and which of the available quantitative approaches best assess the repeatability of these measures. Using a spectrophotometer, we measured melanin-based colouration in barn swallows? (Hirundo rustica) plumage. We assessed the repeatability of measures obtained with both traditional sampling methods separately to quantitatively determine their reliability. We used the ANOVA-based method for calculating the repeatability of measurements from two years separately, and the GLMM-based method to calculate overall adjusted repeatabilities for both years. We repeated the assessment for the whole reflectance spectrum range and only the human-visible part, to assess the influence of the UV component on the reliabilities of sampling methodologies. Our results reveal very high repeatability for lab measurements and a lower, still moderate to high repeatability, for field measurements. Both increased when limited to only the human-visible part, for all plumage patches except the throat, where we observed the opposite trend. Repeatability between sampling methods was quite low including the whole spectrum, but moderate including only the human-visible part. Our results suggest higher reliability for measurements in the lab and higher power and accuracy of the GLMM-based method. They also suggest UV reflectance differences amongst different plumage patches.

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A comparison of animal color measurements using a commercially available digital color sensor and photograph analysis

Current Zoology ◽

10.1093/cz/zoaa016 ◽

2020 ◽

Vol 66 (6) ◽

pp. 601-606 ◽

Cited By ~ 1

Author(s):

Alex D Potash ◽

Daniel U Greene ◽

Gabrielle A Foursa ◽

Verity L Mathis ◽

L Mike Conner ◽

...

Keyword(s):

Skin Color ◽

New Technology ◽

Human Vision ◽

Light Spectrum ◽

Small Aperture ◽

Animal Coloration ◽

Color Sensor ◽

Color Measurements ◽

Measuring Tool ◽

Reliable Methods

Abstract An animal’s pelage, feather, or skin color can serve a variety of functions, so it is important to have multiple standardized methods for measuring color. One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals. New technology in the form of a commercially available handheld digital color sensor could provide an alternative to photography-based animal color measurements. To determine whether a digital color sensor could be used to measure animal coloration, we tested the ability of a digital color sensor to measure coloration of mammalian, avian, and lepidopteran museums specimens. We compared results from the sensor to measurements taken using traditional photography methods. Our study yielded significant differences between photography-based and digital color sensor measurements of brightness (light to dark) and colors along the green to red spectrum. There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum. The average difference in recorded color (ΔE) by the 2 methods was above the threshold at which humans can perceive a difference. There were significant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool. However, the sensor’s small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research. We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.

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Thermal Management Issues in Operational Data Centers: Computational Fluid Dynamics Analysis and Experimental Study

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4035943 ◽

2017 ◽

Vol 9 (3) ◽

Cited By ~ 2

Author(s):

Babak Fakhim ◽

Srinarayana Nagarathinam ◽

Steven W. Armfield ◽

Masud Behnia

Keyword(s):

Thermal Management ◽

Data Center ◽

Data Centers ◽

Electricity Consumption ◽

Field Measurements ◽

Hot Air ◽

Computational Fluid Dynamics Analysis ◽

Higher Power ◽

Operational Data ◽

Management Issues

The increase in the number of data centers in the last decade, combined with higher power density racks, has led to a significant increase in the associated total electricity consumption, which is compounded by cooling inefficiencies. Issues, such as hot air recirculation in the data center room environment, provide substantial challenges in thermal manageability. Three operational data centers have been studied to identify the cooling issues. Field measurements of temperature were obtained and were compared to numerical simulations to evaluate the overall thermal behavior of the data centers and to identify the thermal issues.

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Comparing the Efficiency of Three Inventory Sampling Methods To Determine Timber Volumes in Pinyon-Juniper Woodlands

Western Journal of Applied Forestry ◽

10.1093/wjaf/7.4.110 ◽

1992 ◽

Vol 7 (4) ◽

pp. 110-113 ◽

Cited By ~ 1

Author(s):

Bruce E. Fox ◽

Pamela E. Raskob

Keyword(s):

Standard Error ◽

Sampling Methods ◽

Field Measurements ◽

Measurement Time ◽

Point Sampling ◽

Plot Sampling ◽

Transect Sampling ◽

The Mean ◽

Time Required ◽

Line Intercept

Abstract We compared three sampling methods to determine timber volumes in pinyon-juniper (Pinus edulis-Juniperus spp.) woodlands, fixed radius plots, variable radius "point" sampling, and line intercept transects. Based on the criterion of the square of the standard error of the mean volume per acre multiplied by total time required to take the field measurements, line intercept transect sampling was the most efficient method. Fixed plot sampling had the highest standard error of the mean and highest measurement time, while point sampling fell between the other two methods in measurement time and standard error of the mean. Based on this analysis, transect sampling is an efficient approach for inventorying pinyon-juniper woodlands, in terms of required field time and in the variance estimates of volume per acre. West. J. Appl. For. 7(4):110-113.

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General Aspects of Optical Methods in Dentistry

Advances in Dental Research ◽

10.1177/08959374870010011201 ◽

1987 ◽

Vol 1 (1) ◽

pp. 5-7 ◽

Cited By ~ 5

Author(s):

J.J. Ten Bosch

Keyword(s):

Optical Radiation ◽

Polymeric Materials ◽

Human Vision ◽

Optical Methods ◽

Laser Fusion ◽

Wavelength Selection ◽

Diagnostic Use ◽

Higher Power ◽

Instrumental Measurement ◽

General Aspects

Optical methods may be considered first in relation to vision. At wavelengths and power levels common in vision, optical radiation is harmless, and therefore only diagnostic use can be expected; for treatment uses, other wavelengths and/or higher power levels are needed. Because human vision is of high quality and the most important channel of information, optical methods are only useful as a supplement to it. This supplement is most useful when light properties are employed which are not used by vision: wavelength selection, coherence, and quantification. This leads to the use of fluorescence, holography, and instrumental measurement of contrasts and color, respectively. Applications of such use in dental diagnosis are summarized. Optical methods for treatment include the well-known curing of polymeric materials, photodynamic therapy of tumors and, potentially, laser fusion of enamel and dentin.

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Going Beyond 3-D Imaging: Automated 3-D Montaged image Analysis of Cytological Specimens

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163873 ◽

1996 ◽

Vol 54 ◽

pp. 282-283

Author(s):

Badrinath Roysam ◽

Hakan Ancin ◽

Douglas E. Becker ◽

Robert W. Mackin ◽

Matthew M. Chestnut ◽

...

Keyword(s):

Image Analysis ◽

Structural Changes ◽

Sampling Methods ◽

Spatial Clustering ◽

Three Dimensional ◽

Field Of View ◽

Cell Counting ◽

Depth Of Field ◽

Tissue Cell ◽

Tissue Organization

This paper summarizes recent advances made by this group in the automated three-dimensional (3-D) image analysis of cytological specimens that are much thicker than the depth of field, and much wider than the field of view of the microscope. The imaging of thick samples is motivated by the need to sample large volumes of tissue rapidly, make more accurate measurements than possible with 2-D sampling, and also to perform analysis in a manner that preserves the relative locations and 3-D structures of the cells. The motivation to study specimens much wider than the field of view arises when measurements and insights at the tissue, rather than the cell level are needed.The term “analysis” indicates a activities ranging from cell counting, neuron tracing, cell morphometry, measurement of tracers, through characterization of large populations of cells with regard to higher-level tissue organization by detecting patterns such as 3-D spatial clustering, the presence of subpopulations, and their relationships to each other. Of even more interest are changes in these parameters as a function of development, and as a reaction to external stimuli. There is a widespread need to measure structural changes in tissue caused by toxins, physiologic states, biochemicals, aging, development, and electrochemical or physical stimuli. These agents could affect the number of cells per unit volume of tissue, cell volume and shape, and cause structural changes in individual cells, inter-connections, or subtle changes in higher-level tissue architecture. It is important to process large intact volumes of tissue to achieve adequate sampling and sensitivity to subtle changes. It is desirable to perform such studies rapidly, with utmost automation, and at minimal cost. Automated 3-D image analysis methods offer unique advantages and opportunities, without making simplifying assumptions of tissue uniformity, unlike random sampling methods such as stereology.12 Although stereological methods are known to be statistically unbiased, they may not be statistically efficient. Another disadvantage of sampling methods is the lack of full visual confirmation - an attractive feature of image analysis based methods.

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Abstract #1125: It is the Work of a Higher Power – An Unusual Presentation of Isolated Central Hypothyroidism

Endocrine Practice ◽

10.1016/s1530-891x(20)44767-6 ◽

2016 ◽

Vol 22 ◽

pp. 261

Author(s):

Lavanya Viswanathan ◽

Cherie Vaz

Keyword(s):

Unusual Presentation ◽

Central Hypothyroidism ◽

Higher Power

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Physical Fitness and Resting EEG in Children With Attention Deficit Hyperactivity Disorder

Journal of Psychophysiology ◽

10.1027/0269-8803/a000131 ◽

2015 ◽

Vol 29 (1) ◽

pp. 26-32 ◽

Cited By ~ 7

Author(s):

Ching-Wen Huang ◽

Chung-Ju Huang ◽

Chiao-Ling Hung ◽

Chia-Hao Shih ◽

Tsung-Min Hung

Keyword(s):

Attention Deficit Hyperactivity Disorder ◽

Physical Fitness ◽

Attention Deficit ◽

Resting State ◽

Self Control ◽

Children With Adhd ◽

Hyperactivity Disorder ◽

Higher Power ◽

Eyes Open ◽

The Relationship

Children with attention deficit hyperactivity disorder (ADHD) are characterized by a deviant pattern of brain oscillations during resting state, particularly elevated theta power and increased theta/alpha and theta/beta ratios that are related to cognitive functioning. Physical fitness has been found beneficial to cognitive performance in a wide age population. The purpose of the present study was to investigate the relationship between physical fitness and resting-state electroencephalographic (EEG) oscillations in children with ADHD. EEG was recorded during eyes-open resting for 28 children (23 boys and 5 girls, 8.66 ± 1.10 years) with ADHD, and a battery of physical fitness assessments including flexibility, muscular endurance, power, and agility tests were administered. The results indicated that ADHD children with higher power fitness exhibited a smaller theta/alpha ratio than those with lower power fitness. These findings suggest that power fitness may be associated with improved attentional self-control in children with ADHD.

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