44 research outputs found

    A Glance to the Fragmenta Membranea Manuscript Collection Through Ftir and Radiocarbon Analyses

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    The Fragmenta membranea manuscript fragment collection at the National Library of Finland has proved challenging to date using only traditional paleography. Therefore, radiocarbon dates can contribute to the understanding of these fragments by offering a parallel natural scientific timeline for the parchment the manuscripts are written on. In this study, we apply our previously developed method for radiocarbon dating medieval manuscripts made of parchment. In total 35 datings were made from 14 separate assemblages of manuscripts, being the first systematic wide-scale application of radiocarbon dating to a collection of medieval manuscripts in order to improve their chronological proxy. Additionally, due to the fragmentary and sometimes poor condition of the manuscript fragments of Fragmenta membranea analyzed in this study, we used Fourier-transform infrared spectroscopy (FTIR) to evaluate the quality of the collagen and the presence of contaminants in the fragments affecting the radiocarbon dates. We report out radiocarbon dating results and FTIR screenings for each sample and for each manuscript assemblage, and discuss the applicability of our method in further studies of applying radiocarbon dating on objects of cultural historical interest and value. The results indicate an essential role of high-quality samples and multiple measurements to interpret the radiocarbon dating results.Peer reviewe

    Up in the air: threats to Afromontane biodiversity from climate change and habitat loss revealed by genetic monitoring of the Ethiopian Highlands bat

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    This is the author accepted manuscript. The final version is available on open access from Wiley via the DOI in this recordWhilst climate change is recognised as a major future threat to biodiversity, most species are currently threatened by extensive human-induced habitat loss, fragmentation and degradation. Tropical high altitude alpine and montane forest ecosystems and their biodiversity are particularly sensitive to temperature increases under climate change, but they are also subject to accelerated pressures from land conversion and degradation due to a growing human population. We studied the combined effects of anthropogenic land-use change, past and future climate changes and mountain range isolation on the endemic Ethiopian Highlands long-eared bat, Plecotus balensis, an understudied bat that is restricted to the remnant natural high altitude Afroalpine and Afromontane habitats. We integrated ecological niche modelling, landscape genetics and model-based inference to assess the genetic, geographic and demographic impacts of past and recent environmental changes. We show that mountain range isolation and historic climates shaped population structure and patterns of genetic variation, but recent anthropogenic land-use change and habitat degradation are associated with a severe population decline and loss of genetic diversity. Models predict that the suitable niche of this bat has been progressively shrinking since the last glaciation period. This study highlights threats to Afroalpine and Afromontane biodiversity, squeezed to higher altitudes under climate change while losing genetic diversity and suffering population declines due to anthropogenic land-use change. We conclude that the conservation of tropical montane biodiversity requires a holistic approach, using genetic, ecological and geographic information to understand the effects of environmental changes across temporal scales and simultaneously addressing the impacts of multiple threats.Natural Environment Research Council (NERC

    Assessment of risk factors and glycosylated haemoglobin in early pregnancy as predictors of diabetes in pregnancy

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    Background: The aim of the study was to determine the performance of history of risk factors and universal HBA1c testing as screening tools for diabetes mellitus in the first trimester of pregnancy using OGTT as a gold standard. Methods: A prospective cross-sectional study conducted between 8 and 13±6 weeks in 305 consecutive pregnancies in the antenatal clinics of the University of Port Harcourt Teaching (UPTH) and Rivers State University Teaching Hospital (RSUTH) between January and August 2020. Each woman had oral glucose tolerance test (OGTT), and glycosylated haemoglobin (HBA1c) levels estimation. Multivariate logistic regression analysis was carried out with history of risk factors and HBA1c level as independent variables and OGTT as the dependent variable for the assessment of their predictive performances. Results: The prevalence of DM was 28.85%, 2.62% and 31.48% for GDM, pre-gestational and for both respectively. Family history of DM was associated with high specificity (91.4%) and negative predictive value (NPV) of 68.7% but low sensitivity (9.4%) and positive predictive value (PPV) (33.3%). The receiver operator characteristic curve for HBA1c revealed a significant area under the curve value: 0.653 (CI: 058-0.72), p<0.01. The optimal cut-off for HBA1c from Youden index was 5.25%. HBA1c levels had high specificity (88.5%) and NPV (75.2%) with low sensitivity (36.5%) and PPV (59.3%). Multivariate logistic regression analysis showed HbA1c as the only independent predictor of GDM (p=0.0001). Conclusions: The high prevalence of diabetes (31.48%), underscores the need for universal screening in early pregnancy. The high NPV and specificity of the risk factors for GDM and HBA1c levels better predict pregnancies that are not likely to develop GDM, but they are not suitable for diagnosis because of the low sensitivity and PPV

    Pongamia seed cake as a valuable source of plant nutrients for sustainable agriculture

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    Pongamia, a multipurpose leguminous tree containing non-edible oil, grows widely in India. Oil extracted from the seeds of Pongamia is used as energy source as well as in tanneries while the cake (a byproduct after extracting oil) was found to be rich in all plant nutrients in general and nitrogen (4.28%) and sulfur (0.19%) in particular. Both nitrogen and sulfur were found to be deficient in 100 and 80%, respectively, in soil samples from farmers' fields in Powerguda village of Adilabad district, Andhra Pradesh, India. Use of Pongamia seed cake as a source of plant nutrients for maize, soyabean and cotton was found beneficial in participatory research and development trials on farmers' fields. Further, application of critically deficient micronutrients such as zinc and boron and secondary nutrient sulfur increased crop yields by 16.7 and 19% in soyabean and cotton, respectively. In addition, B:C ratios of 5.03, 1.81 and 2.04 were obtained for soyabean, maize and cotton, respectively, with use of cake as a source of N, however it needed higher initial investment

    Globally, functional traits are weak predictors of juvenile tree growth, and we do not know why

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    1. Plant functional traits, in particular specific leaf area (SLA), wood density and seed mass, are often good predictors of individual tree growth rates within communities. Individuals and species with high SLA, low wood density and small seeds tend to have faster growth rates. 2. If community-level relationships between traits and growth have general predictive value, then similar relationships should also be observed in analyses that integrate across taxa, biogeographic regions and environments. Such global consistency would imply that traits could serve as valuable proxies for the complex suite of factors that determine growth rate, and, therefore, could underpin a new generation of robust dynamic vegetation models. Alternatively, growth rates may depend more strongly on the local environment or growth–trait relationships may vary along environmental gradients. 3. We tested these alternative hypotheses using data on 27 352 juvenile trees, representing 278 species from 27 sites on all forested continents, and extensive functional trait data, 38% of which were obtained at the same sites at which growth was assessed. Data on potential evapotranspiration (PET), which summarizes the joint ecological effects of temperature and precipitation, were obtained from a global data base. 4. We estimated size-standardized relative height growth rates (SGR) for all species, then related them to functional traits and PET using mixed-effect models for the fastest growing species and for all species together. 5. Both the mean and 95th percentile SGR were more strongly associated with functional traits than with PET. PET was unrelated to SGR at the global scale. SGR increased with increasing SLA and decreased with increasing wood density and seed mass, but these traits explained only 3.1% of the variation in SGR. SGR–trait relationships were consistently weak across families and biogeographic zones, and over a range of tree statures. Thus, the most widely studied functional traits in plant ecology were poor predictors of tree growth over large scales. 6. Synthesis. We conclude that these functional traits alone may be unsuitable for predicting growth of trees over broad scales. Determining the functional traits that predict vital rates under specific environmental conditions may generate more insight than a monolithic global relationship can offer

    A systematic review of rodent pest research in Afro-Malagasy small-holder farming systems: Are we asking the right questions?

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    Rodent pests are especially problematic in terms of agriculture and public health since they can inflict considerable economic damage associated with their abundance, diversity, generalist feeding habits and high reproductive rates. To quantify rodent pest impacts and identify trends in rodent pest research impacting on small-holder agriculture in the Afro-Malagasy region we did a systematic review of research outputs from 1910 to 2015, by developing an a priori defined set of criteria to allow for replication of the review process. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We reviewed 162 publications, and while rodent pest research was spatially distributed across Africa (32 countries, including Madagascar), there was a disparity in number of studies per country with research biased towards four countries (Tanzania [25%], Nigeria [9%], Ethiopia [9%], Kenya [8%]) accounting for 51% of all rodent pest research in the Afro-Malagasy region. There was a disparity in the research themes addressed by Tanzanian publications compared to publications from the rest of the Afro-Malagasy region where research in Tanzania had a much more applied focus (50%) compared to a more basic research approach (92%) in the rest of the Afro-Malagasy region. We found that pest rodents have a significant negative effect on the Afro-Malagasy small-holder farming communities. Crop losses varied between cropping stages, storage and crops and the highest losses occurred during early cropping stages (46% median loss during seedling stage) and the mature stage (15% median loss). There was a scarcity of studies investigating the effectiveness of various management actions on rodent pest damage and population abundance. Our analysis highlights that there are inadequate empirical studies focused on developing sustainable control methods for rodent pests and rodent pests in the Africa-Malagasy context is generally ignored as a research topic

    Skin:Conservation of Books

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    Volumes of Worth—Delimiting the Sample Size for Radiocarbon Dating of Parchment

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    Medieval manuscripts are invaluable archives of the written history of our past. Manuscripts can be dated and localized paleographically, but this method has its limitations. The Fragmenta membranea manuscript collection at the National Library of Finland has proved difficult to date using paleographic methods. Radiocarbon dating has been applied to manuscripts of parchment before, but a systematic protocol for radiocarbon dating of parchment has not been established with a minimally destructive sampling strategy. In this work, we have established a radiocarbon dating procedure for parchments combining a clean-room based chemical pretreatment process, elemental analyzer combustion, automatic graphitization and accelerator mass spectrometry (AMS) measurements to reduce the AMS target size from a typical 1 mg of carbon. Prolonged acid treatment resulted in improved dating accuracy, since this is consistent with the manufacturing process of medieval parchment involving a lime bath. Two different combustion processes were compared. The traditional closed tube combustion (CTC) method provided a well-established though labor-intensive way to produce 1 mg AMS targets. The Elemental Analyzer-based process (EA-HASE, Elemental Analyzer Helsinki Adaptive Sample prEparation line), is designed for fast combustion and smaller sample sizes. The EA-HASE process was capable of reproducing the simulated radiocarbon ages of known-age samples with AMS graphite target sizes of 0.3 mg of carbon, corresponding to a 3 mm2 area of a typical medieval parchment. The full potential of the process to go down to as little as 50 mu g will be further explored in the future in parallel to studies of sample-specific contamination issues.Peer reviewe

    Multifaceted DNA

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