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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Technologies for tissue preservation: the role of endogenous and exogenous antioxidants in preserving tissue function in chinook salmon, Oncorhynchus tshawytscha

Tuckey, Nicholas Pierre Lemieux January 2008 (has links)
The seafood industry is of considerable importance to both the New Zealand and global economies and therefore tissue preservation technologies that increase product quality and/or prolong shelf life have the potential to add significant value. Technologies for maintaining the viability of isolated tissues also have a wide range of other medical and industrial applications. This thesis examines the relationship between metabolic function, oxidation and cell death and the resulting stability of the non-viable tissues during long term storage in chinook salmon (Oncorhynchus tshawytscha) red and white skeletal muscle tissue. This research also looks at the role of the aquatic anaesthetic AQUI-S™, in which the active ingredient is isoeugenol (a lipid soluble antioxidant), and other antioxidant compounds in preserving metabolic function in viable tissues and tissue stability in nonviable tissues. Perfusion of salmon tails at 15℃ over 5 or 10 hours with oxygen saturated saline resulted in significant increases in protein and lipid oxidation (protein carbonyl and TBARS concentrations respectively) in the red muscle, but not the white muscle. The introduction of ascorbic acid and uric acid into the saline did not reduce the oxidation in the red muscle despite significantly increasing their respective concentrations in the tissue. This indicates the difficulties associated with attempting to extend tissue viability by delivering free oxygen to the tissue and also highlights the difference in susceptibility of the two muscle types to oxidation. Tail fillets from salmon harvested in both rested and exhausted physiological states using AQUI-S™, and fillets from exhausted salmon harvested without AQUI-S™, were exposed to air at 15℃ for up to 96 hours. Protein carbonyls increased in a roughly linear fashion over the entire 96 hours in all three groups. Both lipid peroxides (TBARS) and uric acid concentrations began to increase in the exhausted group after 30 hours. In contrast, no significant increases in lipid peroxides or uric acid was seen in the fillets from either group harvested using AQUI-S™. Vitamin E concentrations reduced slowly but did not change significantly despite the oxidation that was evident in the tissue. These processes also occurred in salmon tail fillets during storage at 6℃. The measurement of ATP related compounds provides an effective indicator of both the metabolic state of the tissue post-harvest and the quality. The breakdown of these compounds is also associated with the production of ammonia and hydrogen peroxide. Fresh rested salmon fillets had high concentrations of ATP and creatine phosphate, which were both depleted after 12 hours storage at 15℃. This indicates that cell viability lasted a number of hours following harvesting. These metabolites were depleted in exhausted fillets and metabolic potential appeared to be immediately compromised. The concentration of the taste enhancing compound IMP was significantly reduced in fresh rested tissue, but increased during storage, and was significantly higher than in exhausted tissues following 12 hours of storage at 15℃. This indicates that some properties of rested tissues may improve with limited storage times. The accumulation of uric acid - the metabolic end point for ATP related compounds - was also significantly reduced in rested tissue and increases in K-value were slowed. AQUI-S™ showed an ability to preserve tissue function through its anaesthetic action allowing tissue to be harvested in a rested state, and to reduce late stage lipid oxidation in stored salmon tail fillets. The antioxidant action of isoeugenol in salmon fillets may be mediated through its ability to chelate transition metals released during tissue degradation. This research shows that during reperfusion and during fillet storage there is a significant level of oxidative stress, which needs to be minimized while maintaining basic tissue metabolism to prolong tissue and cellular viability. The development of future technologies to preserve tissue viability may depend on the development of a synthetic oxygen carrying compound with properties similar to red blood cells. This may allow more control over oxygen delivery, potentially reducing the oxidative stress associated with high concentrations of free oxygen in solution. However, preserving cell viability will also require the maintenance of endogenous antioxidant function and there is also the potential to use iron chelating compounds including plant derived flavonoids to preserve non-viable tissues. Future research in these areas is necessary.
102

L'attention visuelle sélective : pertinence, saillance, résistance à l'interférence / Visual selective attention : relevance, salience and resistance to interference

Fernandez, Damien 04 November 2010 (has links)
Cette thèse portait sur l'attention visuelle sélective, dans le domaine non-spatial, c'est-à-dire la capacité à favoriser le traitement perceptif de certains objets de la scène visuelle au détriment des autres. En particulier, l'objectif était d'étudier, à l'aide de tâches de recherche visuelle, les différentes interactions possibles entre les processus endogènes (liés aux intentions et connaissances du sujet) et les processus exogènes (liés aux caractéristiques perceptives des objets). Une première série d'expériences démontrait que la saillance pouvait présenter des effets relativement durables. Cependant, ces effets de saillance pouvaient être favorisés ou contrecarrés par des processus endogènes (induits par indiçage portant sur la taille), et modulés par l'amorçage perceptif. Une seconde série d'expériences démontrait que la résistance à l'interférence induite par un distracteur saillant dépendait de ressources attentionnelles centrales, et était modulée par la charge perceptive. Enfin, la troisième série d'expériences validait l'hypothèse d'une intégration entre des signaux endogènes et exogènes compatibles mais strictement distincts. La falsification de l'inégalité de Miller (1982) précisait que cette intégration reposait sur une coactivation effective, non sur une simple facilitation statistique entre signaux strictement indépendants. Le locus cognitif de cette intégration semble être le système perceptif. L'ensemble des données présentées souligne la flexibilité du contrôle attentionnel, et invite à développer un modèle général de l'attention visuelle sélective basé sur l'hypothèse de compétition biaisée (Desimone & Duncan, 1995). / This thesis was about visual selective attention, toward non-spatial features, that is, the ability to favour the perceptual processing of some objects in the visual scene, at the expense of others. In particular, the aim was to study, through visual search experiments, the various possible interactions between endogenous (linked with incentives and knowledge of subjects) and exogenous (linked with perceptual properties of the objects) processes. The first series of experiments showed long-lived salience effects. These salience effects could, hewever, be favoured or overriden by endogenous processes (induced by cueing the target size), and modulated by perceptual priming. The second series evidenced that resisting the interference induced by a salient distractor depended on central attentional resources, and was modulatted by perceptual load. Finally, the third series demonstrated that separate endogenous and exogenous signals could genuinely integrate. This integration could not be accounted for by a race between strictly independant signals, as evidenced by the falsification of the Miller's (1982) inequality. This integration might occur in the perceptual system. Theglobal set of data highlighted the flexibility of endogenous attentional control, and invited developping a general model of visual selective attention, on the basis of the biased competition hypothesis.
103

Analýza vývoje úmrtnosti v Rusku za využití různých metod dekompozice / Analysis of Mortality Development in Russia using various decompositon methods

Kocová, Markéta January 2012 (has links)
Analysis of mortality development in Russia using various decomposition methods Abstract The aim of this thesis is to analyze and evaluate mortality development in Russia in last 50 years by using various decomposition methods. The first part presents the method of decomposition of the difference between two demographic indicators (E. Kitagawa's method or methods from E. Arriaga, R. Pressat and J. Pollard). In the second part mortality development in Russia is analyzed by using methods that decomposed the value of demographic indicators in a given year. Mortality is divided into senescent and background component by using the Gompertz-Makeham formula and by using the logistic model. Afterwards, avoidable and unavoidable mortality and mortality due to endogenous and exogenous causes of death is analyzed. Hypotheses, set out in the introductory chapter, are verified by using different decomposition methods. Using multiple methods of decomposition enable to obtain a more complex view of the evolution of mortality in the observed period so that could be viewed from multiple perspectives and identify specific population trends in Russia. Keywords: mortality, Russia, decomposition, senescent and background mortality, avoidable mortality, endogenous, exogenous, causes of death, mortality crisis
104

Pilotstudie zur Ätiologie der Trisomie 21 im Oman mit molekulargenetischem Schwerpunkt

Näthe, Jenny 10 November 2006 (has links)
Das Down Syndrom trägt wesentlich zur Morbidität und Mortalität im Kindesalter bei und ist die häufigste Ursache geistiger Behinderung bei Neugeborenen. Überwiegend handelt es sich um Neumutationen mütterlichen Ursprungs. Die hohe Rate an Neumutationen und deren starke Zunahme mit dem mütterlichen Alter sprechen dafür, dass die Chromosomensegregation in der Oogenese ein sehr fehleranfälliger Prozess ist. Im Rahmen dieser Pilotstudie konnte eine deutliche Alterskorrelation zwischen dem Auftreten der Geburt eines Down Syndrom Kindes und dem elterlichen Alter beobachtet werden. Wie in anderen publizierten Studien wurde in der vorliegenden Studie gezeigt, dass das Geschlechterverhältnis bei den Down Syndrom Kindern von 1.37:1 (m:w ) deutlich zugunsten der Jungen verschoben ist. Der Schwerpunkt dieser Arbeit lag auf der molekulargenetischen Analyse der elterlichen Herkunft des zusätzlichen Chromosoms 21, der Verteilung der Cross-over, und der Analyse des MTHFR-Polymorphismus. Betrachtet man die 72 voll informativen maternalen Meiosen, so ergibt sich ein Verhältnis von Meiose I zu Meiose II von 80:20. Dieses Verhältnis korreliert mit anderen Studien zur parentalen Herkunft des zusätzlichen Chromosoms 21. Bemerkenswerter Weise fand sich unter den 93 paternal informativen Meiosen kein paternales Non-disjunction Ereignis. Dieses Ergebnis unterscheidet sich von den bisherigen epidemiologischen Studien zur parentalen Herkunft des zusätzlichen Chromosoms 21, wofür derzeit keine Erklärung existiert. Die Assoziation zwischen mütterlichem Alter und meiotischer Rekombination wurde analog zu der Studie von [Lamb et al. 2005] durchgeführt und bestätigt. Die erhobenen Daten aus dem Oman zeigen, dass das C-Allel mit 87% im Oman deutlich häufiger ist als in den anderen untersuchten Populationen. Dieses Ergebnis spricht für eine große geographische Variabilität des Polymorphismus und dafür, dass möglicherweise besondere Selektionsbedingungen auf der arabischen Halbinsel vorliegen. / Down syndrome (DS) is a main cause of human prenatal and postnatal morbidity and mortality, and a leading cause of birth defects and mental retardation. There is increasing evidence that maternal meiosis is an error prone process that is most sensitive to the effect of exogenous factors at the time of chromosomal segregation, which is around conception. In addition to environmental factors, various genetic factors have been described which seem to influence the nondisjunction rate during meiosis. The first data of DS in the Oman yielded a high prevalence among live births. The birth prevalence of Trisomy 21 in Oman with 1:454 newborns is, perhaps, the highest reported so far. We have performed a case control study based on a structured questionnaire, which covers socio demographics, family history and potential risk factors. We identified increased maternal age as one factor for the birth of a DS child. The sex ratio among Down Syndrome children showed a predominance of boys of 1.37:1 (m:f ) as reported from other studies. The main aim of the thesis was to investigate the parental origin of the extra chromosome 21, the number and chromosomal distribution of recombination events. Of the 72 informative cases, 80% were consistent with meiosis I (MI) nondisjunction and 20% with a meiosis II (MII) error during oogenesis. Surprisingly, there were no cases of paternal non-disjunction. These findings differ significantly from other publications where at least 8% were of paternal origin. There is no explanation for this phenomenon at present. Analogous to Lamb et al. we analyzed the association between maternal age and meiotic recombination events and revealed similar results. Furthermore, we investigated the MTHFR-polymorphism among 83 families. In the Oman, the C-allele is more frequent (87%) than in other publications. The results indicate, this polymorphism emerges in a large geographical variety and underlies perhaps special selection on the Arabic Peninsula.
105

Níveis de complexo enzimático em dietas para ruminantes / Enzimatic complex levels in ruminant diets

Brito, Fernando de Oliveira 26 March 2010 (has links)
Foram utilizados 24 cordeiros cruzados Ile de France, com peso médio inicial de 22,27 ± 1,85 kg e, aproximadamente, 80 dias de idade, suplementados com os níveis 0 (controle); 0,3; 0,9 e 2,7 g/kg de MS de produto enzimático comercial, contendo amilase, celulase, fitase, xilanase, betaglucanase, pectinase e protease, adicionado no momento da mistura do concentrado. O desempenho animal não foi afetado pela adição das enzimas, com médias de 37,3 ± 4,3 kg; 1,182 ± 0,153 kg/dia; 0,356 ± 0,077 kg/dia e 3,3 ± 0,3 para o PVF, IMS, GPD e CA, respectivamente. Para a digestibilidade da MS, FDN, FDA, PB, EE, NDT e amido, as médias foram, respectivamente, 80,55; 60,14; 58,80; 81,55; 52,02; 83,16 e 98,20%. A Digestibilidade da FDN apresentou uma tendência de aumento linear conforme o acréscimo do nível de enzima, com uma melhora de 11% para o último nível, em relação ao controle. As demais variáveis não foram alteradas. As concentrações de fósforo e glicose plasmáticos não foram alteradas pela enzima. O protozoário do gênero Entodinium sp. representou mais de 95% do total de ciliados para todos os tratamentos avaliados, e os dados se ajustaram ao efeito quadrático, com o nível de 2,18 kg de enzima/kg de MS proporcionando maior crescimento destes. Para o pH ruminal ao abate, não houve influência das enzimas. Os rendimentos de carcaça quente e fria apresentaram uma queda até os níveis de 1,61 e 1,55 g de enzima/kg de MS, respectivamente, sendo que, após estes valores, os rendimentos se aproximaram novamente do controle. A adição de níveis crescentes de enzimas diminuiu a perda de água por exsudação, mas não afetou a perda por cocção e a maciez da carne de cordeiros. Portanto, apesar da melhora em alguns parâmetros, o desempenho dos animais, bem como as características de carcaça e da carne, não foram afetados pela adição das enzimas, sendo que, para ovinos, o complexo enzimático avaliado não é eficaz sob as mesmas condições experimentais. / Twenty-four crossbred lambs Ile de France, with initial average body weight of 22,7 ± 1,85 kg and age of 80 days, were supplemented with 0 (control treatment); 0,3; 0,9 e 2,7 g/kg DM levels of enzymatic commercial product, with amylase, cellulose, phytase, xylanase, glucanase, pectinase e protease, added at the moment of concentrate mixing. Performance was not affected by enzyme complex supplement,, with averages of 37,3 ± 4,3 kg; 1,182 ± 0,153kg/day, 0,356 ± 0.077 kg/day and 3,3 ± 0,3 for FLW, DMI, ADG and FC, respectively. For DM, NDF, ADF, CP, EE, TDN and starch, the averages were, respectively, 80,55;60,14; 58,80; 81,55; 52,02; 83,16 and 98,20%. There was observed a tendency to FDN digestibility with linear increasing as the enzyme levels increased, with an improvement of 11% for the last level, compared to control diet. All the others variables were not changed. Glucose and phosphorus concentrations were not affected by the enzyme complex. The Entodinium sp. protozoa represented more than 95% of the total ciliated protozoa for all treatments studied and the data were adjusted by the quadratic effect, with the level of 2,18 kg of enzyme/kg of DM showing a better growing of those. Ruminal pH at the slaughter, was not affected by enzymes. Hot dressing percentage and cold dressing percentage decreased until levels of 1,61 and 1,55 g of enzyme/kg of DM, respectively, even when after these data, dressing percentage went back closely to the control treatment. The increasing levels addition of enzyme decreased drip loss, but did not affect the cocking loss and tenderness of lambs meat. Despite the improvement of some parameters, as well as performance, meat and carcass characteristics, were not affect by the enzymes, suggesting that enzyme complex analyzed was not efficient at the same experimental conditions for sheep.
106

多變量TAR模型分析及其在預測流浪教師數的應用 / Multivariate TAR Model Analysis and its Applications to the Vagabond Teachers’ Forecasting

蔡佳玲 Unknown Date (has links)
流浪教師問題是目前教育界中ㄧ重要問題,流浪教師數的預測精準與否,將會影響教育政策的裁定。本研究中,使用多變量門檻自迴歸模式,預測100年度到103年度的流浪教師數量。結果顯示,多變量門檻自迴歸模式較ARIMA模式更能顯現數列的趨勢,對於預測上有極大的幫助。且多變量門檻自迴歸模式的可用範圍很廣,因為一般的時間數列中或多或少都會有結構改變的現象,時間數列的資料普遍存在有非線性現象,且同時受到多個變數影響,此時加入多個外生變數作為考量,更能精準分析資料和做預測。 / The vagabond teachers in elementary schools is an important problem in education administration. An accurate forecast of the number of vagabond teachers in elementary schools may heavily affect educational policy. In this thesis, we use multivariate TAR model analysis to forecast the number of vagabond teachers in elementary schools in Taiwan Area during a period from 100 to 103. According to the result, multivariate TAR model perform well for prediction. Multivariate TAR model can be widely used in different circumstances, especially complicated situation. As far as common time series data is concerned, it has change point or change period occurs.Structural change of a non-linear time series is auniversal phenomenon. Selecting suitable data variables and using exogenous variables to be a threshold, we could obtain better predictable effect by multivariate TAR model.
107

Origin of organic compounds in fluids from ultramafic-hosted hydrothermal vents of the Mid-Atlantic Ridge

Konn, Cécile January 2009 (has links)
Natural gas, primarily methane (CH4), is produced in substantial amounts in ultramafic-hosted hydrothermal systems. These systems could also generate oil (heavier hydrocarbons) and the first building blocks of life (prebiotic molecules). In the presence of iron bearing minerals, serpentinisation reactions generate H2. Subsequently, CH4 could be synthesised by Fischer-Tropsch Type (FTT) reaction (4H2 + CO2 → CH4 + 2H2O) which is an abiotic process. This has lead to the idea of abiotic formation of larger organic molecules. Both thermodynamics and laboratory work support this idea, yet field data have been lacking. This study focuses on determining the organic content of fluids from ultramafic-hosted hydrothermal systems from the Mid-Atlantic Ridge (MAR) and the origin of the compounds. Fluids were collected from the Lost City, Rainbow, Ashadze and Logatchev vent fields during the EXOMAR (2005), SERPENTINE (2007), MoMARDREAMnaut (2007) and MOMAR08-Leg2 (2008) cruises conducted by IFREMER, France. A SBSE-TD-GC-MS technique was developed and used to extract, concentrate, separate and identify compounds in the fluids. Hydrothermally derived compounds appeared to consist mainly of hydrocarbons and O-bearing molecules. In addition, some amino acids were detected in the fluids by ULPC-ESI-QToF-MS but their origin will need to be determined. The organic content of the Rainbow fluids did not show intra field variability unlike differences could be noted over the years. In order to address the question of the source of the molecules, compound specific carbon isotopic analyses were carried out and completed with a bacterial (Pyrococcus abyssi) hydrothermal degradation experiment. The δ13C data fall in the range of -40 to -30‰ (vs. V-PDB), but individual δ13C values preclude the identification of a biogenic or abiogenic origin of the compounds. The degradation experiment, however, suggests an abiogenic origin of a portion of saturated hydrocarbons whereas carboxylic acids would be biogenic, and aromatic compounds would be thermogenic. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted. Paper 4: Submitted. / MoMARnet
108

Critical Evaluation Of Endogenous Regional Development Theories

Cicek, Huseyin 01 February 2013 (has links) (PDF)
Regional development discourses and theories have significantly changed since the born of regional science. Focus of regional development theories has shifted from industrialization efforts via large-scale enterprises and transfer of central government funds to disadvantaged regions to endogenous capabilities and potentials of innovation and knowledge creation. Endogenous factors and self-development capabilities are highly emphasized by recent development literature. Changes in the regional development discourses also affected regional policies, policy tools and actors / endogenous factors and self-development discourses became dominant in regional development policies and implementations. However, source of regional development for less developed regions that do not have endogenous potentials and self-development capability have not clearly defined and have not empirically tested. The thesis attempted to empirically define regional growth factors and the usefulness of theoretical frameworks. In the thesis, econometric model of Turkey is used for the empirical study. The theoretical framework discussed in the thesis is both economic theories and regional development models. The study shows that all theoretical models offer only partial explanations of regional growth. While study shows that factors emphasized by traditional theories support regional growth, the study has no evidence supporting that soft factors emphasized by recent theories support regional growth. The main findings of this study contribute to theoretical and empirical field by reintroducing role of government and interventions. Factors highlighted by recent regional development theories are not sufficient for explaining growth, since the regional policies at the national level continue to be important therefore factors emphasized by traditional theories still have significant contributions to growth.
109

Comparative reproductive strategies between long-tailed ducks and king eiders at Karrak Lake, Nunavut: use of energy resources during the nesting season

Lawson, Shona Louise 21 September 2006
Energy demands can be particularly high in arctic-nesting birds that face harsh, unpredictable conditions during the breeding season. Consequences of these demands, particularly energy-partitioning during egg laying and incubation, are fundamentally important for arctic nesters. This study investigated differences in breeding strategies between Long-tailed Duck (<i>Clangula hyemalis</i>) and King Eider (<i>Somateria spectabilis</i>) in the central Canadian arctic. The focus was on ecological variables and influences of variation in nutrient resources used during incubation and egg production. Research was done at Karrak Lake, Nunavut, where both species nest sympatrically at relatively high densities, permitting comparative research about breeding strategies.<p>This study used stable-carbon (d13C) and nitrogen (d15N) isotope analysis to investigate origins and allocation of endogenous (stored) and exogenous (external) nutrients used in egg production. Remote temperature sensors were placed in nests to estimate and compare incubation rhythms and gain insight into capital and income incubating strategies of both species. Results suggest that breeding Long-tailed Ducks and King Eiders used a mixed breeding strategy, that is they relied on both exogenous and endogenous resources for reproduction. Close correspondence between d13C and d15N values of egg components and potential diet items indicated that King Eiders allocated exogenous nutrients for egg production (albumen 98.1%, yolk protein 96.8%, whole yolk 98.4%, and yolk lipids 84%). Female King Eiders relied on endogenous nutrients for incubation, as evidenced by high incubation constancy (96%). Conversely, the range of d13C values in components of Long-tailed Duck eggs and d13C values of diet items suggested that although some females allocated endogenous reserves for egg production, most females allocated exogenous resources for egg production (albumen 98.5%, yolk protein 78.3%, whole yolk 84.9%, and yolk lipids 38.3%). Long-tailed Duck females had an 84% incubation constancy, suggesting less reliance on endogenous nutrients for incubation than was estimated for female King Eiders. Knowledge about the relative importance of endogenous reserves and exogenous nutrients for egg production and incubation may help direct management decisions to specific winter/staging and or breeding areas used by King Eiders and Long-tailed Ducks.
110

Comparative reproductive strategies between long-tailed ducks and king eiders at Karrak Lake, Nunavut: use of energy resources during the nesting season

Lawson, Shona Louise 21 September 2006 (has links)
Energy demands can be particularly high in arctic-nesting birds that face harsh, unpredictable conditions during the breeding season. Consequences of these demands, particularly energy-partitioning during egg laying and incubation, are fundamentally important for arctic nesters. This study investigated differences in breeding strategies between Long-tailed Duck (<i>Clangula hyemalis</i>) and King Eider (<i>Somateria spectabilis</i>) in the central Canadian arctic. The focus was on ecological variables and influences of variation in nutrient resources used during incubation and egg production. Research was done at Karrak Lake, Nunavut, where both species nest sympatrically at relatively high densities, permitting comparative research about breeding strategies.<p>This study used stable-carbon (d13C) and nitrogen (d15N) isotope analysis to investigate origins and allocation of endogenous (stored) and exogenous (external) nutrients used in egg production. Remote temperature sensors were placed in nests to estimate and compare incubation rhythms and gain insight into capital and income incubating strategies of both species. Results suggest that breeding Long-tailed Ducks and King Eiders used a mixed breeding strategy, that is they relied on both exogenous and endogenous resources for reproduction. Close correspondence between d13C and d15N values of egg components and potential diet items indicated that King Eiders allocated exogenous nutrients for egg production (albumen 98.1%, yolk protein 96.8%, whole yolk 98.4%, and yolk lipids 84%). Female King Eiders relied on endogenous nutrients for incubation, as evidenced by high incubation constancy (96%). Conversely, the range of d13C values in components of Long-tailed Duck eggs and d13C values of diet items suggested that although some females allocated endogenous reserves for egg production, most females allocated exogenous resources for egg production (albumen 98.5%, yolk protein 78.3%, whole yolk 84.9%, and yolk lipids 38.3%). Long-tailed Duck females had an 84% incubation constancy, suggesting less reliance on endogenous nutrients for incubation than was estimated for female King Eiders. Knowledge about the relative importance of endogenous reserves and exogenous nutrients for egg production and incubation may help direct management decisions to specific winter/staging and or breeding areas used by King Eiders and Long-tailed Ducks.

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