102 research outputs found

    Mixed-species allometric equations and estimation of aboveground biomass and carbon stocks in restoring degraded landscape in northern Ethiopia

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    Accurate biomass estimation is critical to quantify the changes in biomass and carbon stocks following the restoration of degraded landscapes. However, there is lack of site-specific allometric equations for the estimation of aboveground biomass (AGB), which consequently limits our understanding of the contributions of restoration efforts in mitigating climate change. This study was conducted in northwestern Ethiopia to develop a multi-species allometric equation and investigate the spatial and temporal variation of C-stocks following the restoration of degraded landscapes. We harvested and weighed 84 trees from eleven dominant species from six grazing exclosures and adjacent communal grazing land. We observed that AGB correlates significantly with diameter at stump height D 30 (R 2 = 0.78; P < 0.01), and tree height H (R 2 = 0.41, P < 0.05). Our best model, which includes D 30 and H as predictors explained 82% of the variations in AGB. This model produced the lowest bias with narrow ranges of errors across different diameter classes. Estimated C-stock showed a significant positive correlation with stem density (R 2 = 0.80, P < 0.01) and basal area (R 2 = 0.84, P < 0.01). At the watershed level, the mean C-stock was 3.8 (±0.5) Mg C ha−1. Plot-level C-stocks varied between 0.1 and 13.7 Mg C ha−1. Estimated C-stocks in three- and seven-year-old exclosures exceeded estimated C-stock in the communal grazing land by 50%. The species that contribute most to C-stocks were Leucaena sp. (28%), Calpurnia aurea (21%), Euclea racemosa (20.9%), and Dodonaea angustifolia (15.8%). The equations developed in this study allow monitoring changes in C-stocks and C-sequestration following the implementation of restoration practices in northern Ethiopia over space and time. The estimated C-stocks can be used as a reference against which future changes in C-stocks can be compared

    Anticancer diterpenes of African natural products: Mechanistic pathways and preclinical developments

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    64 p.Background: The African continent is home to five biodiversity hotspots, boasting an immense wealth of medicinal flora, fungi and marine life. Diterpenes extracted from such natural products have compelling cytotoxic activities that warrant further exploration for the drug market, particularly in cancer therapy, where mortality rates remain elevated worldwide. Purpose: To demonstrate the potential of African natural products on the global stage for cancer therapy development and provide an in-depth analysis of the current literature on the activity of cancer cytotoxic diterpenes from African natural sources (to our knowledge, the first of its kind); not only to reveal the most promising candidates for clinical development, but to demonstrate the importance of preserving the threatened ecosystems of Africa.Universidad de Alcal

    Exploring SAR insights into royleanones for P-gp modulation

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    11 p.Multidrug resistance (MDR) poses a challenge in contemporary pharmacotherapy, significantly reducing the efficacy of chemotherapeutic agents. Among the array of mechanisms underpinning MDR, the upregulation of P-glycoprotein (P-gp), also known as MDR1 and encoded by the ABCB1 gene, emerges as an impediment in cancer treatment success. Plants from the Plectranthus genus (Lamiaceae) are recognised in traditional medicine for their diverse therapeutic applications. 7?-acetoxy-6?-hydroxyroyleanone (Roy), the principal diterpene derived from Plectranthus grandidentatus Gürke, has exhibited anti-cancer properties against various cancer cell lines. Previously synthesized ester derivatives of Roy have shown enhanced binding affinity with P-gp. This study utilises previously obtained in vitro data on P-gp activity of Roy derivatives to construct a ligand-based pharmacophore model elucidating critical features essential for P-gp modulation. Leveraging this data, we predict the potential of five novel ester derivatives of Roy to modulate P-gp in vitro against resistant NCI-H460 cells. A set of 16 previously synthesized royleanone derivatives underwent in silico structure-activity relationship (SAR) studies. A binary classification model, differentiating inactive and active compounds, generated 11,016 Molecular Interaction Field (MIF) descriptors from structures optimized at the DFT theory level. Following variable reduction and selection, a subset of 12 descriptors was identified, yielding a model with two latent variables (LV), utilizing only 34.14 % of the encoded information for calibration (LV1: 26.82 %; LV2: 7.32 %). Ultimately, prediction of the activity of new derivatives suggested all have a high likelihood of activity, which will be validated through future in vitro biological assays.Fundação para a Ciencia e a Tecnologia (FCT, Portugal)Fundação Calouste Gulbenkian (Portugal)Fundação Araucária (Brasil)Ministério da Educação (Brasil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil

    Electron Loss from 1.4-MeV / u U\u3csup\u3e4,6,10+\u3c/sup\u3e Ions Colliding with Ne, N₂, and Ar Targets

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    Absolute, total, single- and multiple-electron-loss cross sections are measured for 1.4-MeV / u U4,6,10+ ions colliding with neon and argon atoms and nitrogen molecules. It is found that the cross sections all have the same dependence on the number of electrons lost and that multiplying the cross sections by the initial number of electrons in the 6s, 6p, and 5f shells yields good agreement between the different projectiles. By combining the present data with previous measurements made at the same velocity, it is shown that the scaled cross sections slowly decrease in magnitude for incoming charge states between 1 and 10, whereas the cross sections for higher-charge-state ions fall off much more rapidly

    Sheep Genome Functional Annotation Reveals Proximal Regulatory Elements Contributed to The Evolution of Modern Breeds

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    Domestication fundamentally reshaped animal morphology, physiology and behaviour, offering the opportunity to investigate the molecular processes driving evolutionary change. Here we assess sheep domestication and artificial selection by comparing genome sequence from 43 modern breeds (Ovis aries) and their Asian mouflon ancestor (O. orientalis) to identify selection sweeps. Next, we provide a comparative functional annotation of the sheep genome, validated using experimental ChIP-Seq of sheep tissue. Using these annotations, we evaluate the impact of selection and domestication on regulatory sequences and find that sweeps are significantly enriched for protein coding genes, proximal regulatory elements of genes and genome features associated with active transcription. Finally, we find individual sites displaying strong allele frequency divergence are enriched for the same regulatory features. Our data demonstrate that remodelling of gene expression is likely to have been one of the evolutionary forces that drove phenotypic diversification of this common livestock species

    SNPchiMp v.3: integrating and standardizing single nucleotide polymorphism data for livestock species

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    Published: 10 April 2015In recent years, the use of genomic information in livestock species for genetic improvement, association studies and many other fields has become routine. In order to accommodate different market requirements in terms of genotyping cost, manufacturers of single nucleotide polymorphism (SNP) arrays, private companies and international consortia have developed a large number of arrays with different content and different SNP density. The number of currently available SNP arrays differs among species: ranging from one for goats to more than ten for cattle, and the number of arrays available is increasing rapidly. However, there is limited or no effort to standardize and integrate array- specific (e.g. SNP IDs, allele coding) and species-specific (i.e. past and current assemblies) SNP information.Here we present SNPchiMp v.3, a solution to these issues for the six major livestock species (cow, pig, horse, sheep, goat and chicken). Original data was collected directly from SNP array producers and specific international genome consortia, and stored in a MySQL database. The database was then linked to an open-access web tool and to public databases. SNPchiMp v.3 ensures fast access to the database (retrieving within/across SNP array data) and the possibility of annotating SNP array data in a user-friendly fashion.This platform allows easy integration and standardization, and it is aimed at both industry and research. It also enables users to easily link the information available from the array producer with data in public databases, without the need of additional bioinformatics tools or pipelines. In recognition of the open-access use of Ensembl resources, SNPchiMp v.3 was officially credited as an Ensembl E!mpowered tool. Availability at http://bioinformatics.tecnoparco.org/SNPchimp.Ezequiel L Nicolazzi, Andrea Caprera, Nelson Nazzicari, Paolo Cozzi, Francesco Strozzi, Cindy Lawley, Ali Pirani, Chandrasen Soans, Fiona Brew, Hossein Jorjani, Gary Evans, Barry Simpson, Gwenola Tosser-Klopp, Rudiger Brauning, John L Williams and Alessandra Stell

    Genome-wide association studies in Japanese quails of the F2 resource population elucidate molecular markers and candidate genes for body weight parameters

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    Molecular research for genetic variants underlying body weight (BW) provides crucial information for this important selected trait when developing productive poultry breeds, lines and crosses. We searched for molecular markers—single nucleotide polymorphisms (SNPs)—and candidate genes associated with this trait in 240 F2 resource population Japanese quails (Coturnix japonica). This population was produced by crossing two breeds with contrasting growth phenotypes, i.e., Japanese (with lower growth) and Texas White (with higher growth). The birds were genotyped using the genotyping-by-sequencing method followed by a genome-wide association study (GWAS). Using 74,387 SNPs, GWAS resulted in 142 significant SNPs and 42 candidate genes associated with BW at the age of 1, 14, 28, 35, 42, 49 and 56 days. Hereby, 25 SNPs simultaneously associated with BW at more than one age were established that colocalized with nine prioritized candidate genes (PCGs), including ITM2B, SLC35F3, ADAM33, UNC79, LEPR, RPP14, MVK, ASTN2, and ZBTB16. Twelve PCGs were identified in the regions of two or more significant SNPs, including MARCHF6, EGFR, ADGRL3, ADAM33, NPC2, LTBP2, ZC2HC1C, SATB2, ASTN2, ZBTB16, ADAR, and LGR6. These SNPs and PCGs can serve as molecular genetic markers for the genomic selection of quails with desirable BW phenotypes to enhance growth rates and meat productivity
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