Nestling begging intensity and parental effort in relation to prelaying carotenoid availability

Carotenoids are antioxidants playing major roles in physiological functions at various stages of an animal's life. Female birds deposit large amounts of carotenoids into their eggs. Carotenoids are, however, a limiting resource, and females are expected to balance carotenoid deposition into the eggs with their utilization for themselves. Carotenoid availability is thus likely to determine both the levels of yolk carotenoids and maternal care during rearing. Carotenoids have been shown to benefit the embryo and the growing nestling, and it can be hypothesized that an increase in carotenoid availability during laying leads to higher nestling condition and competitive ability. We manipulated carotenoid availability to great tit pairs prior to and during egg laying and later partially cross-fostered chicks at hatching. During the rearing period, we measured how carotenoid availability affected nestlings begging behavior and male and female feeding effort. We also manipulated the ectoparasite load, predicting that carotenoid supplementation would help adults and nestling to cope with parasites. Nestlings hatched from eggs laid by carotenoid-supplemented females and raised in small broods begged more intensely. Nestlings in small deparasitized broods also begged more actively. The feeding effort of control females increased with brood size, whereas the feeding effort of carotenoid-supplemented females was high whatever the brood size. Male feeding effort was unaffected by our treatment. Our results support the hypothesis that maternally derived carotenoids increase nestling begging behavior and hence competitive ability. They further suggest that carotenoid availability determines the level of parental investment and can mediate trade-offs between life-history trait

Maternal effects mediated by egg quality in the Yellow-legged Gull Larus michahellis in relation to laying order and embryo sex

<p>Abstract</p> <p>Background</p> <p>Maternal effects mediated by egg size and quality may profoundly affect offspring development and performance, and mothers may adjust egg traits according to environmental or social influences. In avian species, context-dependency of maternal effects may result in variation in egg composition, as well as in differential patterns of covariation among selected egg components, according to, for example, position in the laying sequence or offspring sex. We investigated variation in major classes of egg yolk components (carotenoids, vitamins and steroid hormones) in relation to egg size, position in the laying sequence and embryo sex in clutches of the Yellow-legged Gull (<it>Larus michahellis</it>). We also investigated their covariation, to highlight mutual adjustments, maternal constraints or trade-offs in egg allocation.</p> <p>Results</p> <p>Laying sequence-specific patterns of allocation emerged: concentration of carotenoids and vitamin E decreased, while concentrations of androgens increased. Vitamin A, estradiol and corticosterone did not show any change. There was no evidence of sex-specific allocation or covariation of yolk components. Concentrations of carotenoids and vitamins were positively correlated. Egg mass decreased along the laying sequence, and this decrease was negatively correlated with the mean concentrations of carotenoids in clutches, suggesting that nutritionally constrained females lay low quality clutches in terms of carotenoid content. Finally, clutches with smaller decline in antioxidants between first- and last-laid eggs had a larger increase in yolk corticosterone, suggesting that a smaller antioxidant depletion along the laying sequence may entail a cost for laying females in terms of increased stress levels.</p> <p>Conclusions</p> <p>Since some of the analyzed yolk components (e.g. testosterone and lutein) are known to exert sex-specific phenotypic effects on the progeny in this species, the lack of sex-specific egg allocation by mothers may either result from trade-offs between contrasting effects of different egg components on male and female offspring, or indicate that sex-specific traits are controlled primarily by mechanisms of sexual differentiation, including endogenous hormone production or metabolism of exogenous antioxidants, during embryonic development.</p

Initial syncope associated with alternating attacks of supraventricular tachycardia and atrioventricular block long after surgical correction of tricuspid atresia

The Fontan procedure has become a generic term to define a surgical procedure that orients the systemic venous return directly to the pulmonary arteries, and has been used as a palliative operation for pulmonary atresia, tricuspid atresia, double inlet ventricle and complex single ventricle. The earliest type of Fontan procedure was a simple atriopulmonary anastomosis between the right atrium and the pulmonary artery. Atrial arrhythmias, particularly atrial flutter and sinus node dysfunction may occur in the early and late postoperative period after simple atriopulmonary anastomosis. The case presented here represents a much delayed occurrence of an initial syncope due to alternating attacks of SVT (supraventricular tachycardia) and second degree heart block on admission 21 years after simple atriopulmonary anastomosis performed for the correction of tricuspid atresia. (Cardiol J 2008; 15: 186-188

The effect of smoking on cardiac diastolic parameters including Vp, a more reliable and newer parameter

Background: Previous studies have focused mainly on the acute effects of smoking on the diastolic function of the heart. The present study was conducted to demonstrate the chronic effects of smoking on the diastolic functional parameters of the heart, including transmitral M- mode coloured flow propagation velocity (Vp), among relatively younger asymptomatic adults. Method: Hundred smokers with histories of incessant smoking for at least one year prior to the time of the investigation were included in the prospectively designed study as group I. Group II consisted of 35 non-smokers, matched for age and gender. Addiction to smoking was graded according to the modified Fagerström test for nicotine dependence (M-FNDT). Each smoker was designated by a nicotine dependence index (NDI) according to the M-FNDT. Groups I and II were compared with respect to major diastolic functional parameters on transthoracic echocardiography (TTE), including the E/A ratio, deceleration time (DT), isovolumic relaxation time (IVRT) and Vp, along with basic clinical and echocardiographic parameters. Results: Thirty one smokers in group 1 and 5 non-smokers in group 2 were excluded from the study according to the pre-defined exclusion criteria. Therefore 69 smokers (mean age: 30 &#177; 4.9 years, M/F: 32/37) in group I were compared with 30 non-smokers (mean age: 31.4 &#177; 4.8 years, M/F: 15/15) in group II. In group I the mean values of E/A and Vp were significantly lower (p < 0.001), whereas the mean values of IVRT and DT were significantly higher (p < 0.001) than in group II. In group I the value of NDI was positively correlated with the values of DT and IVTR (p < 0.001) and negatively correlated with the value of Vp (p < 0.001). Conclusion: Conventional and relatively new parameters of cardiac diastolic function, in particular Vp, were found to be impaired in smokers demonstrating the chronic adverse effects of smoking on the diastolic function of the heart. The severity of this impairment was closely correlated with the degree of addiction to smoking. (Cardiol J 2007; 14: 281-286

Wpływ palenia tytoniu na parametry funkcji rozkurczowej lewej komory, w tym na Vp jako nowszy i bardziej wiarygodny parametr

Wstęp: We wcześniejszych badaniach skupiano się głównie na doraźnym, bezpośrednim wpływie palenia tytoniu na funkcję rozkurczową serca. Celem niniejszej pracy było przedstawienie wpływu długotrwałego palenia tytoniu na parametry funkcji rozkurczowej serca, w tym prędkość propagacji napływu mitralnego (Vp), ocenianą w badaniu doplerowskim znakowanym kolorem w prezentacji jednowymiarowej u stosunkowo młodych dorosłych bez objawów. Metody: Badanie miało charakter prospektywny. Do grupy I zakwalifikowano 100 osób palących tytoń nieprzerwanie przez przynajmniej rok przed rozpoczęciem badania. Grupę II stanowiło 35 niepalących pacjentów, dostosowanych do grupy I pod względem wieku i płci. Za pomocą zmodyfikowanego Kwestionariusza Tolerancji Nikotyny Fagerströma (M-FNDT) oceniono stopień uzależnienia od nikotyny u badanych pacjentów. Następnie na podstawie wskaźnika uzależnienia od nikotyny (NDI) uzyskanego z M-FNDT każdego z palaczy przydzielono do odpowiedniej podgrupy. Obie grupy pacjentów porównano na podstawie głównych parametrów rozkurczowych uzyskanych za pomocą echokardiografii przezklatkowej, takich jak stosunek E/A, czas deceleracji (DT), czas rozkurczu izowolumetrycznego (IVRT) i Vp, a także na podstawie podstawowych parametrów klinicznych i echokardiograficznych. Wyniki: Opierając się na wstępnych kryteriach wyłączenia, z badania wykluczono 31 palaczy z grupy I oraz 5 niepalących z grupy II. W rezultacie porównano 69 palaczy (śr. wiek: 30 &#177; &#177; 4,9 roku, M/K: 32/37) z grupy I oraz 30 niepalących (śr. wiek: 31,4 &#177; 4,8 roku, M/K: 15/15) z grupy II. W grupie I średnie wartości stosunku E/A oraz Vp były wyraźnie niższe (p < 0,001), podczas gdy średnie wartości IVRT oraz DT były znamiennie wyższe (p < 0,001) niż w grupie II. W grupie I wartość NDI była wprost proporcjonalna do DT oraz IVTR (p < 0,001) oraz odwrotnie proporcjonalna do Vp (p < 0,001). Wnioski: Zarówno konwencjonalne, jak i względnie nowe parametry oceny funkcji rozkurczowej lewej komory, zwłaszcza Vp, okazały się znacznie gorsze u osób palących tytoń, co odzwierciedla szkodliwy wpływ palenia na funkcję rozkurczową serca. Wielkość tego pogorszenia ściśle korelowała ze stopniem uzależnienia od palenia. (Folia Cardiologica Excerpta 2007; 2: 485&#8211;491

Liver Antioxidants in Relation to Beak Morphology, Gizzard Size and Diet in the Common Eider <i>Somateria mollissima</i>

Antioxidants in the liver are particularly abundant in capital breeders that rely on stored resources for egg production. Capital breeders like eider (hereafter common eider) Somateria mollissima have disproportionately large livers with low levels of coenzyme Q10 when compared to other bird species. Concentrations of total carotenoids and vitamin E in the livers of eiders were smaller than predicted for similarly sized bird species. Eiders with high body condition estimated as body mass relative to skeletal body size had high levels of total carotenoids and low levels of coenzyme Q10. The concentration of total carotenoids per gram of liver increased with age, and vitamin E and total carotenoids accumulated during the winter onwards from February to peak at the start of incubation in April. Total vitamin E, total carotenoids, and coenzyme Q10 per gram of liver decreased with increasing beak volume. The size of the empty gizzard increased with increasing liver mass but decreased with total carotenoids and coenzyme Q10. The main components of the diet were blue mussels Mytilus edulis (40%), draft whelk Nassarius reticulatus (27%), and periwinkle Littorina littorea (10%). The concentration of vitamin E increased with the number of razor clams Ensis sp. and draft whelks in the gizzard and the concentration of total carotenoids increased with the number of beach crabs Carcinus maenas. These observations are consistent with the hypothesis that eiders are limited in their levels of antioxidants through food limitation. Furthermore, they imply that diet and morphological characters involved in food acquisition and processing are important determinants of the level of antioxidants in the liver

Antioxidant systems in chick embryo development. Part 1. Vitamin E, carotenoids and selenium

Chick viability is known to be an important factor determining profitability of the poultry industry. Chick embryo tissues contain a high proportion of highly polyunsaturated fatty acids in the lipid fraction and therefore need antioxidant defence. The antioxidant system of the developing embryo and newly hatched chick includes the antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase), water-soluble antioxidants (ascorbic acid, taurine, carnitine, glutathione, etc.), fat-soluble antioxidants (vitamin E, carotenoids, coenzyme Q) as well as selenium (Se). In fact, the high levels of endogenous antioxidants within the egg and embryonic tissues can clearly serve as a major adaptive mechanism for the protection of the tissue during the oxidative stress experienced at hatching. It has been shown that among different nutrients in the maternal diet which could significantly affect chick embryo development and their viability in the early posthatch life, natural antioxidants have been suggested to play a central role. Our data indicate that increased supplementation of the maternal diet can substantially increase concentrations of vitamin E, carotenoids (especially canthaxanthin) and Se in developing chick tissues and significantly decrease susceptibility to lipid peroxidation being effective nutritional tools to deal with various commercial stresses in poultry production

Improvement in Doppler alternans in patients with severe heart failure: Levosimendan versus dobutamin

Mechanical alternans, an ominous sign of terminal systolic heart failure, could be indirectly shown by Doppler analysis. On the other hand, Levosimendan, a novel agent, improves contractility in patients with HE We searched the effect of L versus dobutamin onto Doppler alternans in patients with systolic HE We found that Levosimendan improves beta-to-beat alteration in patients with systolic HF, demonstrated by pulsed Doppler compared to dobutamin. (C) 2007 Elsevier Ireland Ltd. All rights reserved

Data from: Historical mutation rates predict susceptibility to radiation in Chernobyl birds

Extreme environmental perturbations are rare, but may have important evolutionary consequences. Responses to current perturbations may provide important information about the ability of living organisms to cope with similar conditions in the evolutionary past. Radioactive contamination from Chernobyl constitutes one such extreme perturbation, with significant but highly variable impact on local population density and mutation rates of different species of animals and plants. We explicitly tested the hypothesis that species with strong impacts of radiation on abundance were those with high rates of historical mutation accumulation as reflected by cytochrome b mitochondrial DNA base pair substitution rates during past environmental perturbations. Using a dataset of 32 species of birds we show higher historical mitochondrial substitution rates in species with the strongest negative impact of local levels of radiation on local population density. These effects were robust to different estimates of impact of radiation on abundance, weighting of estimates of abundance by sample size, statistical control for similarity in the response among species due to common phylogenetic descent, and effects of population size and longevity. Therefore, species that respond strongly to the impact of radiation from Chernobyl are also the species that in the past have been most susceptible to factors that have caused high substitution rates in mitochondrial DNA