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Peak Mass (peak + mass)
Selected AbstractsChick provisioning rates and growth in Blacklbrowed Albatross Diomedea melanophris and Grey-headed Albatross D. chrysostoma at Bird Island, South GeorgiaIBIS, Issue 4 2000NICOLAS HUIN We compared the parental division of labour and the pattern and rate of parental provisioning by two sympatric species of albatross of similar mass and breeding timetable but differing in diet and in the duration of chick-rearing. Using electronic weighing platforms inside artificial nests, we recorded chick mass of Black-browed Albatross and Grey-headed Albatross at Bird Island, South Georgia every 10 minutes for both species in 1993 and 1994 and for each species in two other years between 1990 and 1996. The chick mass data (nearly one million weighings) were used to calculate meal mass (over 5000 meals) and intervals between meals. Adult birds were fitted with radio-transmitters which allowed each meal to be allocated to the appropriate parent. The combination of meal mass and foraging trip duration were used to calculate provisioning rates for chicks and individual adults. Overall, Black-browed Albatrosses delivered significantly lighter meals (569 g) than Grey-headed Albatrosses (616 g) but more frequently (every 2.07 days and 2.50 days respectively). Thus combining foraging trip data for both parents, Black-browed Albatross chicks received a meal every 1.22 days compared with 1.26 days for Greyheaded Albatross. These rates did not differ significantly. The contribution of each sex of each species in chick provisioning fluctuated between years, being similar in some years or biased towards males in others. Chicks of both species that failed to fledge received smaller, less frequent meals than successful chicks. In 1990 and 1994, Black-browed Albatross chick provisioning rates were lower than in 1992 and 1993. In 1990, both meal mass and trip duration were affected, but only in 1994 was trip duration longer. Greyheaded Albatross chick provisioning rate was lower in 1994 than in other years but trip duration was longer. In each species, significant changes in meal mass and trip duration occurred within the chick-rearing period. Chick provisioning rates invariably declined before chicks attained their peak mass. For both species, chick growth rates and peak and fledging mass, but not fledging age, were affected by differences in provisioning rate. [source] Fly or die: the role of fat stores in the growth and development of Grey-headed Albatross Diomedea chrysostoma chicksIBIS, Issue 2 2000KEITH REID Chicks of albatrosses, like other Procellariiformes, become independent at a mass similar to their parents but during growth attain a peak mass some 30% or more greater, before losing mass prior to fledging. The current views are that this high peak mass represents chicks storing fat reserves as an energy sink, or as an insurance against periodic food scarcity, or as a Consequence of natural stochastic variation in provisioning rate. We analysed growth and body composition of Grey-headed Albatross Diomedea chrysostoma chicks at Bird Island, South Georgia in 1984 and 1986, two years of very different food availability. In 1984 when overall breeding success was only 28% (the lowest in 20 years and less than halt that in 1986), chicks were significantly smaller in terms of peak mass (by 37%), primary length (by 25%), liver, lung, heart and kidney size (by 18,34%) and fat (by 75,80%) but not significantly different in terms of skeletal (tarsus, culmen, ulna, sternum) or muscle (pectoral, leg) size. Despite these differences, there were some important similarities in the patterns of growth in both years. Up to the attainment of peak mass, most of the growth of organs and of skeletal structures was completed and little fat was deposited. In the remaining part of the chick-rearing period, feather growth and acquisition of fat stores were undertaken. Thus Grey-headed Albatross chicks begin to acquire substantial fat stores only during the later part of the development period; this is contrary to the predictions of any of the existing hypotheses concerning provisioning patterns and the role of fat stores in Procellariiformes. We propose that the deposition of fat in the later stages of chick growth is an adaptation to: (a) ensure against energy demands and/or nutritional stress affecting the quality of flight feathers (many of which are not renewed for up to three years after fledging); and (b) provide an energy reserve for chicks to use in the critical period immediately after independence. [source] Repeatability of chick growth and food provisioning in Manx shearwaters Puffinus puffinusJOURNAL OF AVIAN BIOLOGY, Issue 5 2005Catherine M. Gray In animals that produce few offspring during their lifetime, the ability to raise high-quality offspring through the provision of parental care is particularly important for individual fitness. In this paper, we use repeatability analysis of data from two separate time-periods, in the 1970s and the 1990s, to examine parental and environmental effects on chick growth and food provisioning in a long-lived seabird, the Manx shearwater Puffinus puffinus. We test the hypothesis that asymptotic body masses of chicks are most strongly influenced by an individual's genotype, with growth rates intermediate and food provisioning rates most strongly affected by environmental conditions during growth. Peak body masses of chicks raised by the same parents showed significant repeatability in both samples, whereas mass growth rates up to the attainment of peak mass showed significant repeatability only in the 1970s. Several different measures of food provisioning by parents showed no individual consistency in either time-period, in keeping with our predictions. Food provisioning rate was a major determinant of annual variation in chick growth, and so it may seem surprising that Manx shearwaters showed repeatable patterns of chick growth but not of food provisioning, and several possible explanations for this pattern are discussed. [source] Processing and classification of protein mass spectraMASS SPECTROMETRY REVIEWS, Issue 3 2006Melanie Hilario Abstract Among the many applications of mass spectrometry, biomarker pattern discovery from protein mass spectra has aroused considerable interest in the past few years. While research efforts have raised hopes of early and less invasive diagnosis, they have also brought to light the many issues to be tackled before mass-spectra-based proteomic patterns become routine clinical tools. Known issues cover the entire pipeline leading from sample collection through mass spectrometry analytics to biomarker pattern extraction, validation, and interpretation. This study focuses on the data-analytical phase, which takes as input mass spectra of biological specimens and discovers patterns of peak masses and intensities that discriminate between different pathological states. We survey current work and investigate computational issues concerning the different stages of the knowledge discovery process: exploratory analysis, quality control, and diverse transforms of mass spectra, followed by further dimensionality reduction, classification, and model evaluation. We conclude after a brief discussion of the critical biomedical task of analyzing discovered discriminatory patterns to identify their component proteins as well as interpret and validate their biological implications. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 25:409,449, 2006 [source] | ||||||||||