996 resultados para maternal status


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Eutrophication has become increasingly serious and noxious algal blooms have been of more frequent occurrence in the Yangtze River Estuary and in the adjacent East China Sea. In 2003 and 2004, four cruises were undertaken in three zones in the estuary and in the adjacent sea to investigate nitrate (NO3-N), ammonium (NH4-N), nitrite (NO2-N), soluble reactive phosphorus (SRP), dissolved reactive silica (DRSi), dissolved oxygen (DO), phytoplankton chlorophyll a (Chl a) and suspended particulate matter (SPM). The highest concentrations of DIN (NO3-N+NH4-N+NO2-N), SRP and DRSi were 131.6, 1.2 and 155.6 mu M, respectively. The maximum Chl a concentration was 19.5 mg m(-3) in spring. An analysis of historical and recent data revealed that in the last 40 years, nitrate and SRP concentrations increased from 11 to 97 mu M and from 0.4 to 0.95 mu M, respectively. From 1963 to 2004, N:P ratios also increased from 30-40 up to 150. In parallel with the N and P enrichment, a significant increase of Chl a was detected, Chl a maximum being 20 mg m(-3), nearly four times higher than in the 1980s. In 2004, the mean DO concentration in bottom waters was 4.35 mg l(-1), much lower than in the 1980s. In comparison with other estuaries, the Yangtze River Estuary was characterized by high DIN and DRSi concentrations, with low SRP concentrations. Despite the higher nutrient concentrations, Chl a concentrations were lower in the inner estuary (Zones 1 and 2) than in the adjacent sea (Zone 3). Based on nutrient availability, SPM and hydrodynamics, we assumed that in Zones 1 and 2 phytoplankton growth was suppressed by high turbidity, large tidal amplitude and short residence time. Furthermore, in Zone 3 water stratification was also an important factor that resulted in a greater phytoplankton biomass and lower DO concentrations. Due to hydrodynamics and turbidity, the open sea was unexpectedly more sensitive to nutrient enrichment and related eutrophication processes.

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This paper provides information about the distribution, structure, and ecology of the world's largest alpine ecosystem, the Kobresia pygmaea pastures in the southeastern Tibetan plateau. The environmental importance of these Cyperaceae mats derives from the extremely firm turf, which protects large surfaces against erosion, including the headwaters of the Huang He, Yangtze, Mekong, Salween, and Brahmaputra. The emphasis of the present article is on the climate-driven evolution and recent dynamics of these mats under the grazing impact of small mammals and livestock. Considering pedological analyses, radiocarbon datings, and results from exclosure experiments, we hypothesize that the majority of K. pygmaea mats are human-induced and replace forests, scrub, and taller grasslands. At present, the carrying capacity is increasingly exceeded, and reinforced settlement of nomads threatens this ecosystem especially in its drier part, where small mammals become strong competitors with livestock and the removal of the turf is irreversible. Examples of rehabilitation measures are given.

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Homoploid hybrid plant species are rare, and the mechanisms of their speciation are largely unknown, especially for homoploid hybrid tree species. Two contrasting hypotheses have been proposed to explain the origin of Hippophae goniocarpa: (1) it is a diploid hybrid originating from H. rhamnoides ssp. sinensis x H. neurocarpa ssp. neurocarpa, and (2) it originated via marginal differentiation from H. rhamnoides ssp. sinensis. Regardless of which of these hypotheses is true (if either), previous studies have suggested that H. rhamnoides ssp. sinensis is the only maternal donor for this hybrid species. In this study, we aim to elucidate the maternal composition of H. goniocarpa and to test the two hypotheses. For this purpose, we sequenced the maternal chloroplast DNA trnL-F region of 75 individuals representing H. goniocarpa, H. rhamnoides ssp. sinensis, and H. neurocarpa ssp. neurocarpa in two co-occurring sites of the taxa. Seven haplotypes were identified from three taxonomic units, and their phylogenetic relationships were further constructed by means of maximum parsimony, maximum likelihood, and network analyses. These seven haplotypes clustered into two distinct, highly divergent lineages. Two haplotypes from one lineage were found in H. rhamnoides ssp. sinensis, and five (representing the other lineage) in H. neurocarpa ssp. neurocarpa. Hippophae goniocarpa shared four common haplotypes from both lineages, but the haplotypes detected from the two populations differed to some extent, and in each case were identical to local haplotypes of the putative parental species. Thus, both H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa appear to have together contributed to the maternal establishment of H. goniocarpa. These results clearly demonstrate that the marginal origin hypothesis should be rejected, and support the hybrid origin hypothesis. Hippophae goniocarpa exhibits a sympatric distribution with its two parent species, without occupying new niches or displaying complete ecological isolation. However, this species has effectively developed reproductive isolation from its sympatric parent species. Our preliminary results suggest that H. goniocarpa may provide a useful model system for studying diploid hybrid speciation in trees. (c) 2008 The Linnean Society of London.

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Large-scale grassland rehabilitation has been carried out on the severely degraded lands of the Tibetan plateau. The grasslands created provide a useful model for evaluating the recovery of ecosystem properties. The purposes of this research were: (1) to examine the relative influence of various rehabilitation practices on carbon and nitrogen in plants and soils in early secondary succession; and (2) to evaluate the degree to which severely degraded grassland altered plant and soil properties relative to the non-disturbed native community. The results showed: (1) The aboveground tissue C and N content in the control were 105-97 g m(-2) and 3.356gm(-2), respectively. The aboveground tissue C content in the mixed seed treatment, the single seed treatment, the natural recovery treatment and the severely degraded treatment was 137 per cent, 98 per cent, 49 per cent and 38 per cent, respectively, of that in the control. The corresponding aboveground tissue N content was 109 per cent, 84 per cent, 60 per cent and 47 per cent, respectively, of that in the control. (2) Root C and N content in 0-20 cm depths of the control had an 2 2 average 1606 gm(-2) and 30-36 gm(-2) respectively. Root C and N content in the rehabilitation treatments were in the range of 26-36 per cent and 35-53 per cent, while those in the severely degraded treatment were only 17 per cent and 26 per cent of that in the control. (3) In the control the average soil C and N content at 0-20 cm was 11307 gm(-2) and 846 gm(-2), respectively. Soil C content in the uppermost 20 cm in the seeded treatments, the natural recovery treatment and the severely degraded treatment was 67 per cent, 73 per cent and 57 per cent, respectively, while soil N content in the uppermost 20cm was 72 per cent, 82 per cent and 79 per cent, respectively, of that in the control. The severely degraded land was a major C source. Restoring the severely degraded lands to perennial vegetation was an alternative approach to sequestering C in former degraded systems. N was a limiting factor in seeding grassland. It is necessary for sustainable utilization of seeding grassland to supply extra N fertilizer to the soil or to add legume species into the seed mix. Copyright (c) 2005 John Wiley & Sons, Ltd.

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Chungui Lu, Olga A. Koroleva, John F. Farrar, Joe Gallagher, Chris J. Pollock, and A. Deri Tomos (2002). Rubisco small subunit, chlorophyll a/b-binding protein and sucrose : fructan-6-fructosyl transferase gene expression and sugar status in single barley leaf cells in situ. Cell type specificity and induction by light. Plant Physiology, 130 (3) pp.1335-1348 Sponsorship: BBSRC RAE2008

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The definite article in the Modern Nordic languages is a suffix, etymologically related to a demonstrative. The form is not attested in runic inscriptions, the oldest linguistic sources, but first appears in Icelandic sagas as well as in Swedish and Danish legal codices from 13th century onwards. However, in these texts it does not appear with the same regularity as in modern languages. The Old Swedish form constitutes an intermediate form between a demonstrative, from which it is derived, and the article it has become in Modern Swedish. In the oldest texts it appears in contexts where demonstratives can only be found sporadically and its form suggests it no longer is a demonstrative. At the same time it is not yet obligatory. The aim of this paper is to show the grammaticalization of the definite article as a gradual, dynamic process, involving changes in the form and functional scope of the grammaticalizing item and to consider the properties of the Old Swedish form -in, derived from the distal demonstrative hin ‘that’.

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Objectives. This paper explores the use of regression models for estimating health status of schizophrenic patients, from a Bayesian perspective. Our aims are: 1- To obtain a set of values of health states of the EQ-5D based on self-assessed health from a sample of schizophrenic patients. 2- To analyse the differences in the health status and in patients’ perceptions of their health status between four mental-health districts in Spain. Methods. We develop two linear models with dummy variables. The first model seeks to obtain an index of the health status of the patients using a VAS as a dependent variable and the different dimensions of EQ-5D as regressors. The second model allows to analyse the differences between the self-assessed health status in the different geographic areas and also the differences between the patients’ self-assessed health states, irrespective of their actual health state, in the different geographic areas. The analysis is done using Bayesian approach with Gibbs sampling (computer program WinBUGS 1.4). Data concerning self-assessed EQ-5D with VAS from four geographic areas of schizophrenic patients were obtained for the purposes of this analysis. Results. We obtained the health status index for this sample and analysed the differences for this index between the four geographic areas. Our study reveals variables that explain the differences in patients’ health status and differences in their health states assessment. We consider four possible scenarios.

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National Institute of Child Health and Human Development (HD051804)

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An important component of this Ph.D. thesis was to determine the European consumers’ views on processed meats and bioactive compounds. Thus a survey gathered information form over 500 respondents and explored their perceptions on the healthiness and purchase-ability for both traditional and functional processed meats. This study found that the consumer was distrustful towards processed meat, especially high salt and fat content. Consumers were found to be very pro-bioactive compounds in yogurt style products but unsure of their feelings on the idea of them in meat based products, which is likely due to the lack of familiarity to these products. The work in this thesis also centred on the applied acceptable reduction of salt and fat in terms of consumer sensory analysis. The products chosen ranged in the degree of comminution, from a coarse beef patty to a more fine emulsion style breakfast sausage and frankfurter. A full factorial design was implemented which saw the production of twenty beef patties with varying concentrations of fat (30%, 40%, 50%, 60% w/w) and salt (0.5%, 0.75%, 1.0%, 1.25%, 1.5% w/w). Twenty eight sausage were also produced with varying concentrations of fat (22.5%, 27.5%, 32.5%, 37.5% w/w) and salt (0.8%, 1%, 1.2%, 1.4%, 1.6%, 2%, 2.4% w/w). Finally, twenty different frankfurters formulations were produced with varying concentrations of fat (10%, 15%, 20%, 25% w/w) and salt (1%, 1.5%, 2%, 2.5%, 3% w/w). From these products it was found that the most consumer acceptable beef patty was that containing 40% fat with a salt level of 1%. This is a 20% decrease in fat and a 50% decrease in salt levels when compared to commercial patty available in Ireland and the UK. For sausages, salt reduced products were rated by the consumers as paler in colour, more tender and with greater meat flavour than higher salt containing products. The sausages containing 1.4 % and 1.0 % salt were significantly (P<0.01) found to be more acceptable to consumers than other salt levels. Frankfurter salt levels below 1.5% were shown to have a negative effect on consumer acceptability, with 2.5% salt concentration being the most accepted (P<0.001) by consumers. Samples containing less fat and salt were found to be tougher, less juicy and had greater cooking losses. Thus salt perception is very important for consumer acceptability, but fat levels can be potentially reduced without significantly affecting overall acceptability. Overall it can be summarised that the consumer acceptability of salt and fat reduced processed meats depends very much on the product and generalisations cannot be assumed. The study of bio-actives in processed meat products found that the reduced salt/fat patties fortified with CoQ10 were rated as more acceptable than commercially available products for beef patties. The reduced fat and salt, as well as the CoQ10 fortified, sausages were found to compare quite well to their commercial counterparts for overall acceptability, whereas commercial frankfurters were found to be the more favoured in comparison to reduced fat and CoQ10 fortified Frankfurters.

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Vitamin D deficiency during pregnancy, lactation, and early infancy has been widely reported. Current understanding of vitamin D metabolism during pregnancy and lactation is incomplete, and to date, experimental data to support vitamin D requirements for these life stages are scarce. There is a shortage of nationally representative data and appropriate reference ranges for serum 25-hydroxyvitamin D (25OHD) during pregnancy, lactation and infancy, including in umbilical cord blood. This thesis described concentrations of total 25OHD and individual metabolites including 25OHD3, 25OHD2, and 3-epi-25OHD3 at 15 weeks’ gestation in a large seasonally balanced pregnancy cohort study (n 1768), carried out in Cork, Ireland (52oN). The prevalence of low 25OHD concentrations in pregnant women was higher than published reports in other Caucasian women, and was highest among non-users of vitamin D-containing supplements during winter. A longitudinal pregnancy study was included which suggested gestational stages had an impact on the total serum 25OHD concentration. This thesis incorporated a randomized controlled trial carried out among 100 women across 3 intervention groups using 20 μg/day of vitamin D3 with or without 500 mg calcium, or placebo, over 12-weeks of lactation to investigate the vitamin D requirement for lactating mothers and the vitamin D content of human milk. A daily intake of 25 μg/day was suggested to meet the requirement of lactating women to maintain a 25OHD levels above 50 nmol/L in 97.5% of the population at 52oN all year around. However, vitamin D content in human milk did not increase in response to supplementation. Serum 25OHD concentration has been used as a predictor of a number of health outcomes. This thesis reported large differences in serum 25OHD concentrations using different methods in 86 umbilical cord samples. The need for international standardization of serum 25OHD measurements was re-emphasized in this thesis.