red wing
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2021 ◽  
Author(s):  
F. Talbi ◽  
N. Lamoudi ◽  
L. Reggami ◽  
M. T. Bouazza ◽  
K. Alioua ◽  
...  

Abstract This work reports pressure-broadening line-wing and line-core of the lithium Li (2p ← 2s) resonance line perturbed by ground sodium Na (3s) atoms. In far-wing region the calculations are performed quantum-mechanically and are intended to examine the photoabsorption coefficients at diverse temperatures. The results show the existence of three satellites, in the blue wing near the wavelengths 470nm and in the red wing around 862 and 1070nm. For the line-core region, by adopting the simplified Baranger model the line-width and line-shift rates are determined and their variation law with temperature is examined. No published data were found to compare these results with.


2021 ◽  
Vol 140 (9) ◽  
Author(s):  
Cameron J. Mackie ◽  
Alessandra Candian ◽  
Timothy J. Lee ◽  
Alexander G. G. M. Tielens

AbstractThe profile of the 11.2 μm feature of the infrared (IR) cascade emission spectra of polycyclic aromatic hydrocarbon (PAH) molecules is investigated using a vibrational anharmonic method. Several factors are found to affect the profile including: the energy of the initially absorbed ultraviolet (UV) photon, the density of vibrational states, the anharmonic nature of the vibrational modes, the relative intensities of the vibrational modes, the rotational temperature of the molecule, and blending with nearby features. Each of these factors is explored independently and influence either the red or blue wing of the 11.2 μm feature. The majority impact solely the red wing, with the only factor altering the blue wing being the rotational temperature.


Author(s):  
Conor C. Egan ◽  
Bradley F. Blackwell ◽  
Esteban Fernández-Juricic ◽  
Page E. Klug

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Justin J. Reel ◽  
Todd J. Underwood

Abstract Background Red-winged Blackbirds (Agelaius phoeniceus), hereafter red-wings, are much less frequently parasitized by Brown-headed Cowbirds (Molothrus ater) in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania. Although hosts of Old World cuckoos (Cuculidae) often show geographic variation in egg rejection behavior, cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs. Thus, geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism. In this study, we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population, which may provide insight into low parasitism levels across eastern North America. Methods We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism. Nests were tested across three nest stages and compared to control nests with no manipulations. Because rejection differed significantly by stage, we compared responses separately for each nest stage. We also monitored other songbird nests to identify parasitism frequencies on all potential hosts. Results Red-wings showed significantly more rejections during the building stage, but not for the laying and incubation stages. Rejections during nest building involved mostly egg burials, which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg. Excluding these responses, red-wings rejected 15% of cowbird eggs, which is similar to rejection levels from other studies and populations. The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%. Conclusions Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population. Alternatively, we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism. Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.


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