78,015 research outputs found
Fitness Consequences of Clutch Size Decisions and Mate Change in Black Brant
No full textFor long-lived species with perennial, socially monogamous pair bonds and bi-parental brood care, decisions concerning how much to invest in reproduction and whether to remain with a partner could substantially affect lifetime fitness. I studied the fitness consequences of reproductive effort (Chapter 2) and mate change (Chapters 3-5) in black brant geese (Branta bernicla nigricans, hereafter brant), an Arctic nesting goose species with precocial young. I used a 25 year (1990�"2014) dataset collected at the Tutakoke River brant colony (TRC), in southwestern Alaska, USA to investigate these questions. Brant provide an ideal study species because researchers are able monitor large numbers of individuals and obtain unbiased estimates of fitness components throughout their life cycle. In my second chapter, I used experimental manipulations of clutch and broods sizes (i.e., the number of goslings leaving the nest) to understand if the maximal clutch size laid by brant (i.e., 5 eggs) is under ultimate control as a result of tradeoffs between reproduction and residual reproductive value of females. I used the Barker robust design mark-recapture model to estimate two components of female fitness: (1) true survival and (2) breeding probability in t+1. I found no evidence that incubated clutch size affects future fitness of female brant. However, breeding probability in t+1 (0.82 ± 0.10 [95% CI]) was maximized for females tending 4�"5 goslings and declined for females with smaller or larger brood sizes. Thus, the brood sizes that maximized the residual reproductive value of adult females matched the most common clutch sizes laid by brant. The unexpected result that females tending smaller broods had lower future fitness may result from their smaller family size during winter which may decrease their social status in wintering flocks and result in reduced foraging profitability which may carryover to affect reproduction. My findings support the hypothesis that the maximal clutch size in brant is under ultimate regulation because of tradeoffs with adult residual reproductive value. In Chapter 3, I investigated whether or not mate change influenced reproductive success of female brant. I hypothesized that changing mates could affect reproductive success because (1) new pairs are unfamiliar with each other and (2) females may repair with a male that is an inexperienced breeder (i.e., fewer than two previous breeding attempts at TRC). I investigated the reproductive consequences of mate change using generalized linear models to estimate relative initiation date, clutch size, and the number of goslings leaving the nest and a Cormack-Jolly-Seber mark-recapture analysis to estimate prefledging survival. I found that females breeding with an unfamiliar, but otherwise experienced male fledged at least as many goslings as females breeding with an experienced, familiar mate. However, females who had switched to an inexperienced mate initiated their nests 0.48 (± 0.26 [95% CI]) days later and incubated clutches that were 0.17 (± 0.10 [95% CI]) eggs smaller than females breeding with a familiar mate. More importantly, goslings attended by a mother who was breeding with an experienced, familiar mate had greater prefledging survival (ϕ = 0.30 ± 0.04 [95% CI]) than those whose mother had changed mates in year t and paired with an inexperienced male (ϕ = 0.19 ± 0.04 [95% CI]). These results support the hypothesis that there can be reproductive costs of changing mates for female brant, but male experience rather than familiarity of partners determines these costs. In Chapter 4, I estimated rates of mate retention and investigated if there were long-term fitness benefits of mate retention. This analysis included 3021 and 3039 mature female and male brant who bred at TRC from 1990�"2014. From 1990�"2010, I recorded 748 and 196 breeding attempts after mate change for female and male brant, respectively. I estimated mate fidelity in t+1 of brant that were breeding with a familiar or unfamiliar mate in year t using a multi-strata robust design capture-mark-recapture analysis. I investigated whether breeding with a new mate reduced true survival or breeding probability in t+1 using the Barker robust design capture-mark-recapture framework. I found that mate retention in year t+1 for brant breeding with a familiar mate in year t was high for females (0.881 ± 0.017 [95% CI]) and males (0.952 ± 0.013 [95% CI]). However, for individuals who had switched mates in year t the probability of mate fidelity was greatly reduced for females (0.277 ± 0.163 [95% CI]) and males (0.343 ± 0.246 [95% CI]). There was also long-term fitness costs associated with mate change. Such that individuals who nested with a new mate had true survival rates which were lower (S females = 0.85 ± 0.009 [95% CI]; S males = 0.80 ± 0.017 [95% CI]) than those breeding with a familiar mate in year t (S females = 0.90 ± 0.006 [95% CI]; S males = 0.89 ± 0.011 [95% CI]). Additionally, individuals nesting with a new mate had a lower probability of breeding in year t+1 (females = 0.80 ± 0.035 [95% CI]; males = 0.44 ± 0.090 [95% CI]) than those breeding with a familiar mate in year t (females = 0.96 ± 0.008 [95% CI]; males = 0.98 ± 0.006 [95% CI]). I hypothesize that the demographic costs of mate change are partially related to the relatively low rates of mate retention among newly formed pairs. As a result, individuals breeding with a new mate are more likely to be single for part of the next winter which likely reduces their social status in wintering flocks and results in additional energy expenditure while they attempt to repair. To my knowledge, these results represent the first strong evidence of a link between breeding with a familiar mate and adult demographics in a long-lived bird, with perennial, socially monogamous pair bonds. In my fifth chapter, I investigated factors influencing mate retention and the proportion of female brant that pair with an inexperienced mate after mate change. I predicted that female brant that had undergone a mate change in year t and had paired with an inexperienced breeder or who failed to produce at least one gosling would have low rates of mate retention. I also suspected that brant would pair in a positive assortative manner by body size, previous breeding experience, and age because of the potential fitness benefits of breeding with larger, older and more experienced mates. Contrary to a priori predictions I found that females who had repaired with an inexperienced male were 39% more likely to retain their mate than those who repaired with an experienced male. I found no evidence that successfully producing at least one gosling influenced future mate retention. I recorded 273 cases where experienced female brant switched mates and the new mate was previously marked. In these cases the age of each mate was more strongly correlated (r = 0.26, P < 0.001) than the previous number of breeding attempts by each partner (r = 0.16, P = 0.007). There were weak, but statistically significant correlations between tarsus (r = 0.07, P = 0.012) and culmen (r = 0.07, P = 0.016) lengths of partners (i.e., proxies for structural size). However, body mass during brood-rearing was more strongly correlated among pair members than structural measurements (r = 0.28, P < 0.001). I estimated that about 90% of females who change mates acquire a male who is likely an inexperienced TRC breeder. It is unclear why females who pair with experienced partners have lower rates of mate retention, but it could result from experienced males being in short supply, thereby, enabling them to increase their choosiness in mates. It is clear that most females who change mates will suffer short term reductions in reproductive success, because they will likely acquire partners who are inexperienced breeders. When taken together, the results of chapters 3-5 suggest that there are short and long-term fitness benefits for brant that remained paired with an experienced, familiar partner. These benefits of mate retention may at least partially explain why brant have a perennial, socially monogamous mating system
Navis stultifera
No full texta domino Sebastiano Brant primum edificata: & lepidissimis Teutonice lingue rithmis decorata ; deinde ab Iacobo Lochero philomuso Latinitate donata ; & demum ab Iodoco Badio Ascensio vario carminum genere non sine eorundem familiari explanatione illustrataEnthält das Werk von Jodocus Badius Ascensius, das von Sebastian Brants Werk inspiriert, von diesem aber verschieden istDruckort auf Grund des Druckers erschlossenImpressum aus Kolophon: "Impressum per Nicolaum Lamparter. Anno &c. M.cccc.vi. [i.e. M.ccccc.vi.] die vero. xxvi. mensis Augusti."Signaturen: a⁸b⁴-r⁸s⁴RotschwarzdruckIllustrationen, Zierinitialen, DruckermarkeDigitalisierung=Digitization=Numérisation April 2021 TIF
Navis stultifera
No full texta domino Sebastiano Brant primum edificata: & lepidissimis Teutonice lingue rithmis decorata ; deinde ab Iacobo Lochero philomuso Latinitate donata ; & demum ab Iodoco Badio Ascensio vario carminum genere non sine eorundem familiari explanatione illustrataEnthält das Werk von Jodocus Badius Ascensius, das von Sebastian Brants Werk inspiriert, von diesem aber verschieden istImpressum aus Kolophon: "Impressum Basilee per Nicolaum Lamparter. Anno &c. M.ccccc vii. die vero.xv. mensis Martii."Signaturen: a⁸b⁴-r⁸s⁴RotschwarzdruckIllustrationen, Zierinitialen, DruckermarkeDigitalisierung=Digitization=Numérisation April 2021 TIF
Navis stultifera
No full texta domino Sebastiano Brant primum edificata: & lepidissimis Teutonice lingue rithmis decorata ; deinde ab Iacobo Lochero philomuso Latinitate donata ; & demum ab Iodoco Badio Ascensio vario carminum genere non sine eorundem familiari explanatione illustrataEnthält das Werk von Jodocus Badius Ascensius, das von Sebastian Brants Werk inspiriert, von diesem aber verschieden istDruckort auf Grund des Druckers erschlossenImpressum aus Kolophon: "Impressum per Nicolaum Lamparter. Anno &c. M.cccc.vi. [i.e. M.ccccc.vi.] die vero. xxvi. mensis Augusti."Signaturen: a⁸b⁴-r⁸s⁴RotschwarzdruckIllustrationen, Zierinitialen, DruckermarkeDigitalisierung=Digitization=Numérisation April 2021 TIF
Model based defect characterization in composites
No full textWork is reported on model-based defect characterization in CFRP composites. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing multi-ply impact-induced delamination, with application in this paper focusing on ultrasound. A companion paper in these proceedings summarizes corresponding activity in thermography. Inversion of ultrasound data is demonstrated showing the quantitative extraction of damage properties.This proceeding may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.
This proceeding appeared in Roberts, R., and S. Holland. "Model based defect characterization in composites." In AIP Conference Proceedings, vol. 1806, no. 1, p. 090015. AIP Publishing LLC, 2017, and may be found at
DOI: 10.1063/1.4974659.
Copyright 2017 Author(s).
Posted with permission
On the Elusive Crystallography of Lithium‐Rich Layered Oxides: Novel Structural Models
No full textLithium-rich layered oxides (LRLOs) are one of the most attractive families among future positive electrode materials for the so-called fourth generation of lithium-ion batteries (LIBs). Their electrochemical performance is enabled by the unique ambiguous crystal structure that is still not well understood despite decades of research. In the literature, a clear structural model able to describe their crystallographic features is missing thereby hindering a clear rationalization of the interplay between synthesis, structure, and functional properties. Here, the structure of a specific LRLO, Li1.28Mn0.54Ni0.13Co0.02Al0.03O2, using synchrotron X-ray diffraction (XRD), neutron diffraction (ND), and High-Resolution Transmission Electron Microscopy (HR-TEM), is analyzed. A systematic approach is applied to model diffraction patterns of Li1.28Mn0.54Ni0.13Co0.02Al0.03O2 by using the Rietveld refinement method considering the R (Formula presented.) m and C2/m unit cells as the prototype structures. Here, the relative ability of a variety of structural models is compared to match the experimental diffraction pattern evaluating the impact of defects and supercells derived from the R (Formula presented.) m structure. To summarize, two possible models able to reconcile the description of experimental data are proposed here for the structure of Li1.28Mn0.54Ni0.13Co0.02Al0.03O2: namely a monoclinic C2/m defective lattice (prototype Li2MnO3) and a monoclinic defective supercell derived from the rhombohedral R (Formula presented.) m unit cell (prototype LiCoO2)
Time energy budgets and food use of Atlantic brant across their wintering range
No full textWe conducted extensive behavioral and food sampling of Atlantic brant (Branta bernicla hrota) across their winter range and used time-activity budgets for brant to determine daily energy expenditure (DEE). Sampling occurred 1 December-31 May 2006-2008 in 11,225-km2 sites between Rhode Island and Virginia containing important estuarine and upland habitat. To calculate DEE we used instantaneous scan sampling to estimate time-activity budgets. We also determined foods eaten by brant and energy density of food plants. Last, we quantified body condition of brant, which differed among years, months, regions, and ages, and sexes. Overall DEE for brant was 1,530 ± 64 kJ/day. There was considerable variation in time-activity budgets among years, months, regions, habitat, tide, temperature, and time-of-day, but we detected no significant difference in DEE of brant between years or among regions. However, DEE in January (2,018 ± 173 kJ/day) was nearly double the DEE of brant in May (1,048 ± 137 kJ/day). Brant spent their time feeding (32.3%), swimming (26.2%), resting (16.2%), and flying (14.5%). The percent of brant foreguts sampled contained macroalgae (53%) eelgrass (Zostera marina; 18%), salt marsh cordgrass (Spartina alterniflora; 17%), and terrestrial grass (Poa. sp.) and clover (Trifollium sp.; 9%). Energy density differed by vegetation type: macroalgae (12.6 ± 0.1 kJ/g), eelgrass (14.1 ± 0.1 kJ/g), new-growth salt marsh cordgrass (16.9 ± 0.2 kJ/g), and terrestrial grass and clover (17.7 ± 0.1 kJ/g). Atlantic brant exhibited behavioral plasticity thereby allowing modification of daily activity budgets to meet seasonally varying energetic requirements associated with wintering and spring staging. Recognizing a variable DEE can be used along with eventual estimates of food biomass and total metabolizable energy on the landscape to calculate carrying capacity (goose use days) on state, region, or range-wide scales. © 2011 The Wildlife Society
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Liftings for noncomplete probability spaces
No full textThe current state of knowledge concerning liftings for noncomplete probability spaces is discussed. This is a somewhat expanded version of the author's talk given at the 1991 Summer Conference on General Topology and Applications in Honor of Mary Ellen Rudin and Her Work.PT: S; CR: BURKE MR, IN PRESS P AM MATH S BURKE MR, 1991, ISRAEL J MATH, V73, P33 BURKE MR, 1992, ISRAEL J MATH, V79, P289 CARLSON T, THEOREM LIFTING CHRISTENSEN JPR, 1974, TOPOLOGY BOREL STRUC FREMLIN DH, 1989, HDB BOOLEAN ALGEBRAS, P877 INOESCUTULCEA A, 1966, 5TH P BERK S MATH ST, V2 IONESCUTULCEA A, 1967, CONTRIBUTIONS PROB 1, P63 IONESCUTULCEA A, 1969, TOPICS THEORY LIFTIN JECH TJ, 1978, SET THEORY JOHNSON RA, 1980, P AM MATH SOC, V80, P234 JUST W, IN PRESS T AM MATH S KUPKA J, 1983, INDIANA U MATH J, V32, P717 LOSERT V, 1983, LNM, V1080, P95 MAHARAM D, 1958, P AM MATH SOC, V9, P987 SHELAH S, 1983, ISRAEL J MATH, V45, P90 TALAGRAND M, 1982, P AM MATH SOC, V84, P379 VONNEUMANN J, 1931, CRELLES J MATH, V165, P109; NR: 18; TC: 0; J9: ANN N Y ACAD SCI; PG: 4; GA: BZ86BSource type: Electronic(1
Regional and intraseasonal variation in diet of wintering and staging Atlantic brant
No full textRegional and intraseasonal patterns of food use influence populations through impacts on breeding success, survival, and distribution of individuals. We used both traditional foregut content analysis and stable carbon and nitrogen isotopes in liver and leg muscle to determine intraseasonal patterns in the diet of Atlantic brant geese (Branta bernicla hrota) from early winter through spring staging (1 Dec-31 May 2007-2008) along the mid-Atlantic coast of the United States. Overall, brant diet consisted of macroalgae (52%), salt marsh cordgrass (22%), eelgrass (18%), and terrestrial grass and clover (8%). Mean δ13C and δ15N values differed among these 4 food sources. Therefore, we used an isotope mixing-model (SIAR) to estimate the relative contributions of each source to brant diet among regions and months. Wintering brant in northern and southern regions ate mostly macroalgae throughout the wintering period and ate more salt marsh and terrestrial grasses in spring. Brant in central regions had a more stable diet from December to May. Regional and intraseasonal patterns in brant diet are likely affected by several factors including variation in food source availability and quality due to synergistic effects of long-term annual and intraseasonal changes in abundance of submerged aquatic vegetation. Our estimates of diet combined with information on brant daily energy requirements and forage quality can be used to more accurately determine carrying capacity of wintering brant geese given established population objectives
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