38,677 research outputs found
Song post exposure, song features, and predation risk
No full textMale birds use song to attract mates and deter other males, but in doing so, they also attract the attention of predators and parasites. Such viability costs are inherent in reliable signals, potentially causing females to prefer mates that display from the most exposed sites. However, viability costs of sexual signals may be ameliorated by affecting the choice of microhabitat, which in turn may affect the design of song features that are most efficiently transmitted in this microhabitat. We estimated the exposure of song posts (microsites used by males when singing) used by passerine birds in relation to prey selection by the sparrowhawk Accipiter nisus, by calculating the proportion of males that sang from song posts that were at the maximum level of the vegetation, in an attempt to quantify the costs of sexual selection. We quantified prey susceptibility to predation as the difference between the log-transformed observed number of prey minus the log-transformed expected number of prey in the environment. This prey susceptibility index increased with increasing song post exposure similarly in sexually dichromatic and monochromatic species, although the prey susceptibility index was related to sexual dichromatism. Song post exposure was dependent on habitat, but comparative models controlling for the potentially confounding effects of habitat, sexual dichromatism, hole nesting, coloniality, body mass, cognitive capacities, and flying abilities indicated that the relationship between the prey susceptibility index and song post exposure is strong. Path analyses of the relationship between song post exposure, sexual dichromatism, and prey susceptibility index revealed that selection acting on sexual dichromatism and song post exposure has secondary impact on prey susceptibility index. The opposite causal mechanisms by which predation affects sexual traits are less likely. These models suggest that female preference for high song posts or dichromatic plumage increases predation risk on an evolutionary time scale. Copyright 2006.birds; costs of sexual selection; prey selection; sound transmission
q-Differential equations for q-classical polynomials and q-Jacobi-Stirling numbers
No full textWe introduce, characterise and provide a combinatorial interpretation for the so-called q-Jacobi–Stirling numbers.
This study is motivated by their key role in the (reciprocal) expansion of any power of a second order
q-differential operator having the q-classical polynomials as eigenfunctions in terms of other even order operators,
which we explicitly construct in this work. The results here obtained can be viewed as the q-version of
those given by Everitt et al. and by the first author, whilst the combinatorics of this new set of numbers is a
q-version of the Jacobi–Stirling numbers given by Gelineau and the second author
Age-dependent health status and song characteristics in the barn swallow
No full textBird song has been hypothesized to evolve, partly, to signal health status of males, and song features should therefore correlate with parasite load. Immune function, parasitism, and secondary sexual characters can, however, differ between age classes, and any apparent relationship between song and parasite loads can be the result of systematic age effects. We tested for an age-dependent relationship between sexually selected characters and measures of parasitism in a Spanish population of the barn swallow Hirundo rustica. A comparison across age classes revealed that chewing lice load, song duration, mean peak amplitude frequency of songs, and tail length differed significantly between yearlings and adults. In a longitudinal analysis, we found significant evidence for mean peak amplitude frequency of songs, tail length and chewing louse parasitism, and a nonsignificant tendency for song duration to change with age of an individual. We found a significant association between song duration and chewing louse load and between hematocrit and peak amplitude frequency of the rattle, the typical harsh terminal syllable. In tests for associations between song traits and health status, while controlling for age, age and chewing louse load were independently related to song duration. We found a significant relationship between pairing success and song duration, implying that females may use this song trait in their choice of parasite-free males. Although the song of the barn swallow may provide information about both male age and parasite resistance, signaling of health status appears to be independent of age effects, in accordance with the theory of parasite-mediated sexual selection, suggesting that male signals can be used as reliable indicators of parasitism. Copyright 2005.age; barn swallow; bird song; chewing louse; hematocrit; sedimentation rate
Huchimingia podocarpa Z. Q. Song
No full text6. Huchimingia podocarpa (Dunn) Z.Q. Song in Song et al. (2022: 49). ≡ Millettia podocarpa Dunn (1912: 166). Type: — MYANMAR. Upper Burma, Upper Chindwin, Byinbou, December 1907, A. E . Meebold 7823 (holotype: K000848691!; isotypes: E00275442!, K000848692!).Published as part of Song, Zhu-Qiu, Li, Shi-Jin, Vu, Quang Nam & Khang, Nguyen Sinh, 2022, Taxonomic notes on the genus Millettia (Fabaceae: Millettieae) in Vietnam, pp. 169-185 in Phytotaxa 571 (2) on page 181, DOI: 10.11646/phytotaxa.571.2.4, http://zenodo.org/record/728433
Psalm Song | 10-96080
No full textPsalm Song (Psalm 100)
Part Number: 10-96080
Price: $2.10
Voicing: SATB
Music By: James Q. Mulholland
with Horn
Commissioned by Crossgates United Methodist Church, Brandon, Mississippi,in Celebration of Celia Lymberis\u27 35th Anniversary as OrganistBenjamin Turner, Director of Musichttps://digitalcommons.butler.edu/jca_scores/1233/thumbnail.jp
Huchimingia piscidia Z. Q. Song
No full text5. Huchimingia piscidia (Roxb.) Z.Q. Song in Song et al. (2022: 48). ≡ Millettia piscidia (Roxburgh 1832: 240) Wight (1838: t. 86) ≡ Galedupa piscidia Roxb. ≡ Pongamia piscidia (Roxb.) Sweet (1839: 193) ≡ Phaseolodes piscidia Kuntze (1891: 201). Type: — INDIA. cultivated in Calcutta Botanical Garden, introduced from Silhet, 1813, W. Roxburgh s.n. (lectotype: BM012554441!, designated by Dunn 1912: 166). This species was recorded by Hô (1999) from Vietnam, but it was not included by Lôc & Vidal (2001). Most recently, Song et al. (2022) transfered it to the genus Huchimingia and suggested it is distributed in China, India and Myanmar. Thus, the species should be excluded from the flora of Vietnam.Published as part of Song, Zhu-Qiu, Li, Shi-Jin, Vu, Quang Nam & Khang, Nguyen Sinh, 2022, Taxonomic notes on the genus Millettia (Fabaceae: Millettieae) in Vietnam, pp. 169-185 in Phytotaxa 571 (2) on page 181, DOI: 10.11646/phytotaxa.571.2.4, http://zenodo.org/record/728433
The limiting case of Haglund's (q,t)-Schröder theorem and an involution formula
No full textAbstractAs a generalization of Haglund's statistic on Dyck paths [Conjectured statistics for the q,t-Catalan numbers, Adv. Math. 175 (2) (2003) 319–334; A positivity result in the theory of Macdonald polynomials, Proc. Nat. Acad. Sci. 98 (2001) 4313–4316], Egge et al. introduced the (q,t)-Schröder polynomial Sn,d(q,t), which evaluates to the Schröder number when q=t=1 [A Schröder generalization of Haglund's statistic on Catalan paths, Electron. J. Combin. 10 (2003) 21pp (Research Paper 16, electronic)]. In their paper, Sn,d(q,t) was conjectured to be equal to the coefficient of a hook shape on the Schur function expansion of the symmetric function ∇en, which Haiman [Vanishing theorems and character formulas for the Hilbert scheme of points in the plane, Invent. Math. 149 (2002) 371–407] has shown to have a representation-theoretic interpretation. This conjecture was recently proved by Haglund [A proof of the q,t-Schröder conjecture, Internat. Math. Res. Not. (11) (2004) 525–560]. However, because that proof makes heavy use of symmetric function identities and plethystic machinery, the combinatorics behind it is not understood. Therefore, it is worthwhile to study it combinatorially. This paper investigates the limiting case of the (q,t)-Schröder Theorem and obtains interesting results by looking at some special cases
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No full textA press release from Network Q announcing that they will begin featuring Brian McNaught, a gay columnist and author, for a monthly segment
Network Q
No full textA press release from Network Q announcing that they will begin featuring Brian McNaught, a gay columnist and author, for a monthly segment
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