945 research outputs found

    Estimating Use-Values and Relative Importance of Amazonian Flood Plain Trees and Forests to Local Inhabitants

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    Use-values have been advocated as a tool to compare the value of not just individual species, but also of plant families and forest types to local people, in order, for example, to identify species or habitats in need of special management or conservation. We estimated use-values in three forest types (upper restinga, lower restinga, tahuampa) on the Amazon flood plain south of Iquitos (Peru), compared two methodologies, identified the most valuable species and contrasted these valuations with the actual use of forest resources in local villages. A new method for estimating use-values was contrasted with the method of Phillips and Gentry (1993a). Despite philosophical and procedural differences, estimates were highly correlated (R2=0.86). We discuss limitations of both methods and suggest some possible enhancements. The need to discriminate between past, present and potential uses is emphasised

    Structure and Floristic Composition of Flood Plain Forests in the Peruvian Amazon I. Overstorey

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    Three Peruvian flood plain forests adjacent to the Ucayali river were sampled using nine 1 ha permanent sample plots in which stems exceeding 10 cm DBH were identified and measured. These plots were measured four times during 1993-1997. Three plots were established in each of the three forest types high restinga, low restinga, and tahuampa, characterised in part by an annual inundation of one, two and four months per year, respectively. Stem density varied from 446 to 601 per hectare, and the basal area ranged between 20 and 29 m2/ha. A total of 321 species were recorded in the nine hectare sample, with 88-141 species in each 1 ha plot. Species composition indicated a relatively low similarity between the forest types. Plots with the longest flooding contained the most species, expressed both as per unit area as well as per 1000 stems. The flood plain forests contained fewer tree species than adjacent non-flooded terra firme forest. Family importance values were calculated for each forest. In all three forests Leguminosae, Euphorbiaceae, Annonaceae and Lauraceae were important. The Moraceae family was conspicuous in both high restinga and low restinga. The Arecaceae and Meliaceae were notable in high restinga, as was Rubiaceae in low restinga. Lecythidaceae, Sapotaceae and Chrysobalanaceae exhibited relatively high values in the tahuampa forest. High species importance values were obtained for Maquira coriacea, Guarea macrophylla, Terminalia oblonga, Spondias mombin, Ceiba pentandra, Hura crepitans, Eschweilera spp., Canipsiandra angustifolia, Pouteria spp., Licania micrantha, Parinari excelsa and Calycophyllum spruceanum. Among the species of smaller stature, Drypetes amazonica, Leonia glycicarpa, Theobroma cacao and Protium nodulosum attained high values

    First-time fathers experiences of their prenatal preparation in relation to challenges met in the early parenthood period : Implications for early parenthood preparation

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    Objective to describe first-time fathers experiences of their prenatal preparation in relation to challenges met in the early parenthood period. Design a qualitative study was conducted and data was analysed with a phenomenographical approach. Setting and participants 15 first-time fathers were recruited from three postnatal units in southern Sweden and interviewed approximately one month after their baby was born. Measurements and findings three categories and 14 conceptions about fathers' experiences of their preparation emerged from the data. ‘Acquiring knowledge and forming realistic expectations' was essential for ‘Developing strategies' and ‘Being facilitated and supported' enhanced these processes. Key conclusions and implications for practice supporting fathers to develop strategies for life with a new baby and providing expert guidance to fruitful and accurate information may help the construction of a fatherhood identity and strengthen the fatherhood role. The findings can be used to develop a parental preparation for early parenthood that will correspond to fathers' needs

    Estructura y Composicion Floristica del Bosque de la Llanura Aluvial en la Amazonia Peruana: I. El Bosque Alto

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    Three peruvian flood plain forests adjacent to the Ucayali river were sampled using nine one hectare permanent sample plots in which stems exceeding 10 cm DBH were identified and measured. These plots have been measured 4 times during 1993-1997, and provide the basis for the results reported here. Three plots were established in each of the three forest types high restinga, low restinga, and tahuampa, characterized in part by and annual inundation of 1, 2 and 4 months per year, respectively. Stem density varies from 446 to 601 per ha, and the basal area ranges between 20-29 m2/ha. A total of 321 species were recorded in the nine hectare sample, with 88-141 species in each one hectare plot. Species composition indicated a relatively low similarity between the forest types. Plots with the longest flooding contained the most species, expressed both as per unit area as well as per 1 000 stems. The flood plain forests contain fewer tree species than the non-flooded terra firme forest. In all three forests Legminosae, Euphorbiaceae, Annonaceae and Lauraceae, are important. The Moraceae family is conspicuous in both high restinga, as is Rubiaceae in low restinga. Lecythidaceae, Sapotaceae, and Chrysobalanaceae exhibit relatively high values in the tahuampa forest. High species importance values are obtained for Maquira coriacea, Guarea macrophylla, Terminalia oblonga, Spondias mombin, Ceiba pentandra, Hura crepitans, Schweilera spp., Campsiandra angustifolia, Pouteria spp., Licania micrantha, Parinari excelsa, and Calycophyllum spruceanum. Among the species of smaller stature, Drypetes amazonica, Leonia glycicarpa, Theobroma cacao, and Protium nodulosum attain high values

    A comprehensive epigenomic analysis of phenotypically distinguishable, genetically identical female and male Daphnia pulex

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    Background Daphnia species reproduce by cyclic parthenogenesis involving both sexual and asexual reproduction. The sex of the offspring is environmentally determined and mediated via endocrine signalling by the mother. Interestingly, male and female Daphnia can be genetically identical, yet display large differences in behaviour, morphology, lifespan and metabolic activity. Our goal was to integrate multiple omics datasets, including gene expression, splicing, histone modification and DNA methylation data generated from genetically identical female and male Daphnia pulex under controlled laboratory settings with the aim of achieving a better understanding of the underlying epigenetic factors that may contribute to the phenotypic differences observed between the two genders. Results In this study we demonstrate that gene expression level is positively correlated with increased DNA methylation, and histone H3 trimethylation at lysine 4 (H3K4me3) at predicted promoter regions. Conversely, elevated histone H3 trimethylation at lysine 27 (H3K27me3), distributed across the entire transcript length, is negatively correlated with gene expression level. Interestingly, male Daphnia are dominated with epigenetic modifications that globally promote elevated gene expression, while female Daphnia are dominated with epigenetic modifications that reduce gene expression globally. For examples, CpG methylation (positively correlated with gene expression level) is significantly higher in almost all differentially methylated sites in male compared to female Daphnia. Furthermore, H3K4me3 modifications are higher in male compared to female Daphnia in more than 3/4 of the differentially regulated promoters. On the other hand, H3K27me3 is higher in female compared to male Daphnia in more than 5/6 of differentially modified sites. However, both sexes demonstrate roughly equal number of genes that are up-regulated in one gender compared to the other sex. Since, gene expression analyses typically assume that most genes are expressed at equal level among samples and different conditions, and thus cannot detect global changes affecting most genes. Conclusions The epigenetic differences between male and female in Daphnia pulex are vast and dominated by changes that promote elevated gene expression in male Daphnia. Furthermore, the differences observed in both gene expression changes and epigenetic modifications between the genders relate to pathways that are physiologically relevant to the observed phenotypic differences.Peer reviewe

    Characterisation of the dynamic nature of lipids throughout the lifespan of genetically identical female and male Daphnia magna

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    Lipids play a significant role in regulation of health and disease. To enhance our understanding of the role of lipids in regulation of lifespan and healthspan additional studies are required. Here, UHPLC-MS/MS lipidomics was used to measure dynamic changes in lipid composition as a function of age and gender in genetically identical male and female Daphnia magna with different average lifespans. We demonstrate statistically significant age-related changes in triglycerides (TG), diglycerides (DG), phosphatidylcholine, phosphatidylethanolamine, ceramide and sphingomyelin lipid groups, for example, in males, 17.04% of TG lipid species decline with age whilst 37.86% increase in relative intensity with age. In females, 23.16% decrease and 25.31% increase in relative intensity with age. Most interestingly, the rate and direction of change can differ between genetically identical female and male Daphnia magna, which could be the cause and/or the consequence of the different average lifespans between the two genetically identical genders. This study provides a benchmark dataset to understand how lipids alter as a function of age in genetically identical female and male species with different average lifespan and ageing rate.Peer reviewe

    Pattern of DNA methylation in daphnia : evolutionary perspective

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    DNA methylation is an evolutionary ancient epigenetic modification that is phylogenetically widespread. Comparative studies of the methylome across a diverse range of non-conventional and conventional model organisms is expected to help reveal how the landscape of DNA methylation and its functions have evolved. Here, we explore the DNA methylation profile of two species of the crustacean Daphnia using whole genome bisulfite sequencing. We then compare our data with the methylomes of two insects and two mammals to achieve a better understanding of the function of DNA methylation in Daphnia. Using RNA-sequencing data for all six species, we investigate the correlation between DNA methylation and gene expression. DNA methylation in Daphnia is mainly enriched within the coding regions of genes, with the highest methylation levels observed at exons 2-4. In contrast, vertebrate genomes are globally methylated, and increase towards the highest methylation levels observed at exon 2, and maintained across the rest of the gene body. Although DNA methylation patterns differ among all species, their methylation profiles share a bimodal distribution across the genomes. Genes with low levels of CpG methylation and gene expression are mainly enriched for species specific genes. In contrast, genes associated with high methylated CpG sites are highly transcribed and evolutionary conserved across all species. Finally, the positive correlation between internal exons and gene expression potentially points to an evolutionary conserved mechanism, whereas the negative regulation of gene expression via methylation of promoters and exon 1 is potentially a secondary mechanism that has been evolved in vertebrates

    Benefits of combination of insulin degludec and liraglutide are independent of baseline glycated haemoglobin level and duration of type 2 diabetes

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    AIM: To evaluate, using post hoc analyses, whether the novel combination of a basal insulin, insulin degludec, and a glucagon‐like peptide‐1 receptor agonist, liraglutide (IDegLira), was consistently effective in patients with type 2 diabetes (T2D), regardless of the stage of T2D progression. METHODS: Using data from the DUAL I extension [insulin‐naĂŻve patients uncontrolled on oral antidiabetic drugs (OADs), n = 1660, 52 weeks] and DUAL II (patients uncontrolled on basal insulin plus OADs, n = 398, 26 weeks) randomized trials, the efficacy of IDegLira was investigated with regard to measures of disease progression stage including baseline glycated haemoglobin (HbA1c), disease duration and previous insulin dose. RESULTS: Across four categories of baseline HbA1c (≀7.5–9.0%), HbA1c reductions were significantly greater with IDegLira (1.1–2.5%) compared with IDeg or liraglutide alone in DUAL I. In DUAL II, HbA1c reductions were significantly greater with IDegLira (0.9–2.5%) than with IDeg in all but the lowest HbA1c category. In DUAL I, insulin dose and hypoglycaemia rate were lower across all baseline HbA1c categories for IDegLira versus IDeg, while hypoglycaemia was higher with IDegLira than liraglutide, irrespective of baseline HbA1c. In DUAL II, insulin dose and hypoglycaemia rate were similar with IDegLira and IDeg (maximum dose limited to 50 U) independent of baseline HbA1c. The reduction in HbA1c with IDegLira was independent of disease duration and previous insulin dose but varied depending on pre‐trial OAD treatment. CONCLUSIONS: IDegLira effectively lowered HbA1c across a range of measures, implying suitability for patients with either early or advanced T2D
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