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Infant mortality and isotopic complexity: new approaches to stress, maternal health and weaning.Beaumont, Julia, Montgomery, Janet, Buckberry, Jo, Jay, Mandy 03 2015 (has links)
Yes / Objectives
Studies of the carbon and nitrogen stable isotope ratios (δ13C and δ15N) of modern tissues with a fast turnover, such as hair and fingernails, have established the relationship between these values in mothers and their infants during breastfeeding and weaning. Using collagen from high-resolution dentine sections of teeth which form in the perinatal period we investigate the relationship between diet and physiology in this pivotal stage of life.
Materials and Methods
Childhood dentine collagen δ13C and δ15N profiles were produced from horizontal sections of permanent and deciduous teeth following the direction of development. These were from two 19th-century sites (n = 24) and a small number (n = 5) of prehistoric samples from Great Britain and Ireland.
Results
These high-resolution data exhibit marked differences between those who survived childhood and those who did not, the former varying little and the latter fluctuating widely.
Discussion
Breastfeeding and weaning behavior have a significant impact on the morbidity and mortality of infants and the adults they become. In the absence of documentary evidence, archaeological studies of bone collagen of adults and juveniles have been used to infer the prevalence and duration of breastfeeding. These interpretations rely on certain assumptions about the relationship between isotope ratios in the bone collagen of the adult females and the infants who have died. The data from this study suggest a more complex situation than previously proposed and the potential for a new approach to the study of maternal and infant health in past populations.
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Identifying cohorts using isotope mass spectrometry: the potential of temporal resolution and dietary profilesBeaumont, Julia, Bekvalac, J., Harris, Sam, Batt, Catherine M. 14 February 2021 (has links)
Yes / Archaeological skeletal material from most sites represents a cross-sectional, opportunistic sample of the burials. These are influenced by the proportion and area of the site which is excavated, the taphonomic conditions and survival of tissues. This may not be representative of the population, and in an attritional cemetery may represent a long period of use, during which humans will have differing life-courses. Here we describe a commingled skeletal assemblage, the only human remains recovered from the historically significant medieval site of St Stephen’s Chapel, Palace of Westminster, London. Using carbon (δ13C) and nitrogen (δ15N) stable isotope ratios of bulk bone collagen and incremental dentine to investigate dietary life histories from 5 individuals, we combine the evidence with radiocarbon dating to assign them to two different temporal cohorts.
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Estudo da fixação biológica do nitrogênio em leguminosas (família Fabaceae) arbóreas tropicais através do enriquecimento isotópico do 15N / Estimates of biological nitrogen fixation by tropical legume trees (Fabaceae) using 15N labeled fertilizerColetta, Luciana Della 14 October 2010 (has links)
A família Fabaceae abundante nos trópicos, desperta grande interesse para o uso em recuperação de áreas degradas, já que em sua maioria, são lenhosas e perenes, se adaptam aos mais diversos ecossistemas brasileiros e são capazes de fazer associações simbiônticas com bactérias pertencentes ao gênero Rhizobium, que fixam nitrogênio atmosférico fornecendo-o para a planta em uma forma reativa. Dentro deste contexto, o presente estudo avaliou em um experimento em casa de vegetação como a fixação biológica de nitrogênio em três espécies pertencentes a família Fabaceae variou em função da adição de nitrogênio mineral em diferentes doses e através de tratamentos incluindo-se a inoculação com bactérias do gênero Rhizobium e fungos micorrízicos arbusculares (FMAs). Os resultados obtidos através da atividade da redução de acetileno indicaram que os nódulos se encontravam ativos no último mês de experimento nas três espécies fixadoras de N2. Houve uma grande variação na porcentagem de N na planta proveniente da fixação (NPPfix). Quando as plantas cresceram em meio onde a disponibilidade de N era baixa, sem a aplicação deste nutriente no solo, a FBN foi favorecida, variando de 34 a 84%. Pelo contrário, foi possível observar que a fixação foi inibida em vasos onde a adição de nitrogênio foi elevada. Devido ao uso do solo não esterilizado, os inoculantes aplicados (bactérias e fungos) parecem ter competido com a microbiota nativa do solo, assim sendo, diferenças entre os tratamentos inoculados e o controle (sem inoculação) não foram encontradas neste estudo / Legumes (Fabaceae) are abundant in the tropics and considered as of great interest as restorer of degraded areas, since most of them are woody and perennials, adapted to several Brazilian ecosystems and able to make associations with bacteria belonging to Rhizobium genus, which fix atmospheric nitrogen, and giving it to the plants in a reactive form. In this context, this study evaluated in a greenhouse experiment how nitrogen biological fixation (FBN) varied in three species of Fabaceae family according to the N-mineral addition in different doses and according to treatments including inoculation with bacteria of Rhizobium genus and arbuscular mycorrhizal fungi (AMF). The results obtained from the acetylene reduction activity indicate that the nodules were active in the last month of experiment in the three N2-fixing species. There was a wide variation in the plant N percentage derived from fixation (NPPfix). When plants grew in a soil where N availability was low, without application of this nutrient in the soil, the BNF was favored, ranging the NPPfix from 34 to 84%. On the contrary, it was possible to observe that FBN was inhibited in the pots where N additions were higher. Due to the use of unsterilized soil, the applied inoculants (bacteria and fungi) appear to have competed with the native soil microbiota, thus differences between inoculated and control (without inoculation) could not be established in this study
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Weaned Upon A Time : Studies of the Infant Diet in PrehistoryHowcroft, Rachel January 2013 (has links)
This thesis is concerned with how prehistoric infants were fed in different physical and cultural environments, and in particular what impact the economic, social, and epidemiological changes associated with the development of agriculture had on infant feeding practices. In order to examine these effects, stable isotope ratio analysis has been used to assess the duration of breastfeeding and weaning in a variety of prehistoric contexts. The first study is of Pitted Ware Culture hunter-gatherers at the site of Ajvide on Gotland, Sweden. Breastfeeding usually continued for at least two years, but there was some variation in supplementary foods, which is attributed to seasonal variations in resource availability. The second study analysed a number of Neolithic and early Bronze Age sites from south-east Poland. Breastfeeding duration varied both within and between sites and ranged from six months to five years. The third study found that the infant feeding practices of two Iron Age populations on Öland, Sweden, were very varied, and infants may have been fed differently depending on their social status. The fourth study is of the childhood diet in the Únětice Culture of south-west Poland. Individual diets changed little during the lifetime, suggesting that eventual adult identity was determined early in life. A small number of infants in the study were found to have breastfed for differing lengths of time. The final paper considers the health consequences of introducing animal milks into the infant diet in a prehistoric context, and finds that their availability is unlikely to have made it possible to safely wean infants earlier. Comparison of the results from the four stable isotope studies to those of other published studies reveals that the modal age at the end of weaning was slightly lower in agricultural communities than hunter-gatherer communities, but the range of ages was similar. Weaning prior to the age of eighteen months was rare before the post-medieval period. It is argued that the gradual reduction in breastfeeding duration since the Neolithic, and the replacement of breastmilk with animal milk products, means that on the whole the development of agriculture probably served to increase infant morbidity and mortality. / <p>At the time of doctoral defense the following papers were unpublished and had a status as follows: Paper 1: Manuscript; Paper 4: Accepted; Paper 5: Forthcoming 2014</p> / Lactase Persistence and the early Cultural History of Europe (LeCHE)
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A comparison of the stable isotopic ecology of eastern, western, and pre-human forest ecosystems in the South Island of New ZealandJohnston, Olivia Rose January 2014 (has links)
New Zealand forests have been reduced and degraded by gross removal, logging, and the effects of mammals introduced by Polynesian and European settlers. These changes increase the value of the remaining forests, so information on the effects of these disturbances will be useful to inform the management of forest protection. Integrated measurements of C and N cycling within forests can be obtained using foliar stable isotope ratios, which may detect differences between forests resulting from natural or anthropogenic disturbances. This thesis characterises the stable isotopic composition distribution and likely drivers of isotopic variation of vegetation in several central South Island forests, and provides a baseline for future ecological New Zealand studies of present and pre-human vegetation. The largest detected stable isotope variation in modern leaf material was that of δ15N values between the eastern and western podocarp-broadleaf forests. This variation was probably controlled by the lower soil N availability associated with the high rainfall of western forests causing low δ15N values (-8.5 ± 3.5 ‰) relative to an eastern forest (+1.6 ± 1.3 ‰) and global temperate forests (average -2.8 ± 2.0 ‰ (Martinelli et al. 1999)). The significant but slightly higher mean δ15N (0.6 ‰) of a historically selectively logged forest (Saltwater Forest) in comparison to the mean in an unlogged forest (Okarito Forest), on the West Coast, could be attributed to either alteration to N cycling from logging, site differences in topography, or local soil N differences between the forests. Although δ13C showed no significant geographical variation, the well-described ‘canopy effect’ was observed in all modern forests, manifested as a positive covariation between δ13C and vegetation height. Similarly, large taxon-specific differences were observed between δ15N and δ13C values in both modern and fossil leaves. Well-preserved fossil leaves, from sediments c. 4500 years B.P in Pyramid Valley, North Canterbury, had higher δ13C (4.2 ‰) and δ15N (2.5 ‰) values than modern vegetation from Riccarton Bush, Christchurch. The difference between ecosystems spanning several millennia probably reflects ecosystem-scale changes in C and N cycling within New Zealand forests following human arrival, particularly from the degradation caused by invasive animals.
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Estudo da fixação biológica do nitrogênio em leguminosas (família Fabaceae) arbóreas tropicais através do enriquecimento isotópico do 15N / Estimates of biological nitrogen fixation by tropical legume trees (Fabaceae) using 15N labeled fertilizerLuciana Della Coletta 14 October 2010 (has links)
A família Fabaceae abundante nos trópicos, desperta grande interesse para o uso em recuperação de áreas degradas, já que em sua maioria, são lenhosas e perenes, se adaptam aos mais diversos ecossistemas brasileiros e são capazes de fazer associações simbiônticas com bactérias pertencentes ao gênero Rhizobium, que fixam nitrogênio atmosférico fornecendo-o para a planta em uma forma reativa. Dentro deste contexto, o presente estudo avaliou em um experimento em casa de vegetação como a fixação biológica de nitrogênio em três espécies pertencentes a família Fabaceae variou em função da adição de nitrogênio mineral em diferentes doses e através de tratamentos incluindo-se a inoculação com bactérias do gênero Rhizobium e fungos micorrízicos arbusculares (FMAs). Os resultados obtidos através da atividade da redução de acetileno indicaram que os nódulos se encontravam ativos no último mês de experimento nas três espécies fixadoras de N2. Houve uma grande variação na porcentagem de N na planta proveniente da fixação (NPPfix). Quando as plantas cresceram em meio onde a disponibilidade de N era baixa, sem a aplicação deste nutriente no solo, a FBN foi favorecida, variando de 34 a 84%. Pelo contrário, foi possível observar que a fixação foi inibida em vasos onde a adição de nitrogênio foi elevada. Devido ao uso do solo não esterilizado, os inoculantes aplicados (bactérias e fungos) parecem ter competido com a microbiota nativa do solo, assim sendo, diferenças entre os tratamentos inoculados e o controle (sem inoculação) não foram encontradas neste estudo / Legumes (Fabaceae) are abundant in the tropics and considered as of great interest as restorer of degraded areas, since most of them are woody and perennials, adapted to several Brazilian ecosystems and able to make associations with bacteria belonging to Rhizobium genus, which fix atmospheric nitrogen, and giving it to the plants in a reactive form. In this context, this study evaluated in a greenhouse experiment how nitrogen biological fixation (FBN) varied in three species of Fabaceae family according to the N-mineral addition in different doses and according to treatments including inoculation with bacteria of Rhizobium genus and arbuscular mycorrhizal fungi (AMF). The results obtained from the acetylene reduction activity indicate that the nodules were active in the last month of experiment in the three N2-fixing species. There was a wide variation in the plant N percentage derived from fixation (NPPfix). When plants grew in a soil where N availability was low, without application of this nutrient in the soil, the BNF was favored, ranging the NPPfix from 34 to 84%. On the contrary, it was possible to observe that FBN was inhibited in the pots where N additions were higher. Due to the use of unsterilized soil, the applied inoculants (bacteria and fungi) appear to have competed with the native soil microbiota, thus differences between inoculated and control (without inoculation) could not be established in this study
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