Bird Feces as Indicators of Metal Pollution: Pitfalls and Solutions

Bird feces are commonly used as a proxy for measuring dietary metal exposure levels in wild populations. Our study aims to improve the reliability and repeatability of fecal metal measurements and gives some recommendations for sampling. First, we studied levels of variation in metallic element (arsenic, calcium, cadmium, cobalt, copper, nickel, lead) concentrations: temporal variation within an individual, among siblings in a brood and among-brood/spatial variation. Second, we explored the variation caused by dual composition (urate vs. feces) of bird droppings. Two sets of fresh fecal samples were collected from pied flycatcher (Ficedula hypoleuca) nestlings living in a metal polluted area in summers 2017 (dataset 1) and 2018 (dataset 2). We found a great deal of temporal intra-individual variation in metal levels, suggesting that dietary exposure varied markedly in a short time scale (within a day). A sample from only one nestling per brood did not well describe the brood mean value, and we recommend that at least four siblings should be sampled. Brood level samples give relatively good temporal repeatability for most metals. For all the metals, the levels in the fecal portion were more than double to those in the urate portion. Since the mass proportion of urate in the bird droppings varied a great deal among samples, standardizing sampling, e.g., by collecting only the fecal part, would markedly reduce the variation due to composition. Alternatively, urate portion could be used for biomonitoring of internally circulated bioavailable metal.

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Periodic Variations in the Coronal Green Line Intensity and their Connection with the White-light Coronal Structures

International Astronomical Union Colloquium ◽

10.1017/s0252921100064484 ◽

2000 ◽

Vol 179 ◽

pp. 197-200

Author(s):

Milan Minarovjech ◽

Milan Rybanský ◽

Vojtech Rušin

Keyword(s):

Time Resolution ◽

White Light ◽

Short Time Scale ◽

High Time Resolution ◽

Green Line ◽

Periodic Intensity ◽

Coronal Green Line ◽

Significant Intensity ◽

Short Time ◽

Coronal Structures

AbstractWe present an analysis of short time-scale intensity variations in the coronal green line as obtained with high time resolution observations. The observed data can be divided into two groups. The first one shows periodic intensity variations with a period of 5 min. the second one does not show any significant intensity variations. We studied the relation between regions of coronal intensity oscillations and the shape of white-light coronal structures. We found that the coronal green-line oscillations occur mainly in regions where open white-light coronal structures are located.

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Faculty Opinions recommendation of On the simulation of protein folding by short time scale molecular dynamics and distributed computing.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1005159.177184 ◽

2002 ◽

Author(s):

Tamar Schlick

Keyword(s):

Molecular Dynamics ◽

Protein Folding ◽

Distributed Computing ◽

Time Scale ◽

Short Time Scale ◽

Short Time

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Nondiffusive Brownian Motion Studied by Diffusing-Wave Spectroscopy

MRS Proceedings ◽

10.1557/proc-177-225 ◽

1989 ◽

Vol 177 ◽

Author(s):

D. J. Pine ◽

D. A. Weitz ◽

D. J. Durian ◽

P. N. Pusey ◽

R. J. A. Tough

Keyword(s):

Autocorrelation Function ◽

Colloidal Particles ◽

Scattered Light ◽

Short Time Scale ◽

Velocity Autocorrelation Function ◽

Velocity Autocorrelation ◽

Power Law Decay ◽

Brownian Particles ◽

Short Time ◽

Surrounding Fluid

ABSTRACTOn a short time scale, Brownian particles undergo a transition from initially ballistic trajectories to diffusive motion. Hydrodynamic interactions with the surrounding fluid lead to a complex time dependence of this transition. We directly probe this transition for colloidal particles by measuring the autocorrelation function of multiply scattered light and observe the effects of the slow power-law decay of the velocity autocorrelation function.

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On the Short Time Scale Evolutionary History of the Contact Binary VW Cephei

Highlights of Astronomy ◽

10.1017/s1539299600021468 ◽

1998 ◽

Vol 11 (1) ◽

pp. 396-396

Author(s):

I. Pustylnik

Keyword(s):

Evolutionary History ◽

Light Curves ◽

Published Data ◽

Short Time Scale ◽

Flare Activity ◽

Considerable Portion ◽

History Of ◽

Contact Binary ◽

Elongation Phase ◽

Short Time

We study the short-time evolutionary history of the well-known contact binary VW Cep. Our analysis is based partly on the numerous UBV lightcurves obtained at Tartu Observatory, IUE spectra, and samples from the published data. Special attention is given to the effects of asymmetry of the light curves. A higher degree of asymmetry outside the eclipses along with the significant displacements of the brightness maxima in respect to the elongation phase is interpreted as evidence that a considerable portion of the flaring source is concentrated close to the neck connecting the components. We discuss the nature of asymmetry in terms of possible mass exchange and the flare activity and compare the results of our model computations with the record of orbital period variations over the last 60 years.

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An Alternative Test Using Algal Cultures for Testing Chemicals for Toxicity

Alternatives to Laboratory Animals ◽

10.1177/026119299302100213 ◽

1993 ◽

Vol 21 (2) ◽

pp. 196-201

Author(s):

Søren Achim Nielsen ◽

Thomas Hougaard

Keyword(s):

Size Distribution ◽

Mitotic Activity ◽

Time Scale ◽

Test System ◽

Short Time Scale ◽

Toxic Substances ◽

Alternative Test ◽

Short Time ◽

Algal Cultures ◽

Test Cultures

An alternative test is presented, in which algal cultures are used for testing toxic substances. This test system is based on variations in the size distribution of cells in test cultures as a measurement of growth. Thus, inhibition of mitotic activity is used as a measurement for toxic effects. The test can be performed on a short time-scale and is very sensitive to even weak toxic doses.

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Contactless Video-Based Heart Rate Monitoring of a Resting and an Anesthetized Pig

Animals ◽

10.3390/ani11020442 ◽

2021 ◽

Vol 11 (2) ◽

pp. 442

Author(s):

Meiqing Wang ◽

Ali Youssef ◽

Mona Larsen ◽

Jean-Loup Rault ◽

Daniel Berckmans ◽

...

Keyword(s):

Heart Rate ◽

Estimation Error ◽

Well Being ◽

Absolute Error ◽

Mean Value ◽

Video Data ◽

Window Functions ◽

The Face ◽

Short Time ◽

Better Than

Heart rate (HR) is a vital bio-signal that is relatively easy to monitor with contact sensors and is related to a living organism’s state of health, stress and well-being. The objective of this study was to develop an algorithm to extract HR (in beats per minute) of an anesthetized and a resting pig from raw video data as a first step towards continuous monitoring of health and welfare of pigs. Data were obtained from two experiments, wherein the pigs were video recorded whilst wearing an electrocardiography (ECG) monitoring system as gold standard (GS). In order to develop the algorithm, this study used a bandpass filter to remove noise. Then, a short-time Fourier transform (STFT) method was tested by evaluating different window sizes and window functions to accurately identify the HR. The resulting algorithm was first tested on videos of an anesthetized pig that maintained a relatively constant HR. The GS HR measurements for the anesthetized pig had a mean value of 71.76 bpm and standard deviation (SD) of 3.57 bpm. The developed algorithm had 2.33 bpm in mean absolute error (MAE), 3.09 bpm in root mean square error (RMSE) and 67% in HR estimation error below 3.5 bpm (PE3.5). The sensitivity of the algorithm was then tested on the video of a non-anaesthetized resting pig, as an animal in this state has more fluctuations in HR than an anaesthetized pig, while motion artefacts are still minimized due to resting. The GS HR measurements for the resting pig had a mean value of 161.43 bpm and SD of 10.11 bpm. The video-extracted HR showed a performance of 4.69 bpm in MAE, 6.43 bpm in RMSE and 57% in PE3.5. The results showed that HR monitoring using only the green channel of the video signal was better than using three color channels, which reduces computing complexity. By comparing different regions of interest (ROI), the region around the abdomen was found physiologically better than the face and front leg parts. In summary, the developed algorithm based on video data has potential to be used for contactless HR measurement and may be applied on resting pigs for real-time monitoring of their health and welfare status, which is of significant interest for veterinarians and farmers.

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