396 research outputs found

    African mountain thistles: generic delimitation problems analyzed with NGS

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    PĂłster presentado en el III Simposio Anual de BotĂĄnica EspaĂąola celebrado en el Institut BotĂ nic de Barcelona, 25-26 de noviembre de 202

    Secreted Phosphoprotein 24 kD (Spp24) and Spp14 Affect TGF-β Induced Bone Formation Differently

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    Transforming growth factor-β (TGF-β) and bone morphogenetic proteins (BMPs) have opposing but complementary functions in directing bone growth, repair, and turnover. Both are found in the bone matrix. Proteins that bind to and affect the activity of these growth factors will determine the relative abundance of the growth factors and, therefore, regulate bone formation. Secreted phosphoprotein 24 kD (Spp24) is a bone matrix protein that has been demonstrated to bind to and affect the activity of BMPs. The arginine-rich carboxy terminus of Spp24 is proteolytically processed to produce three other predictable truncation products (Spp18.1, Spp16.0, and Spp14.5). In this work, we report that kinetic data obtained by surface plasmon resonance demonstrate that Spp24 and the three C-terminal truncation products all bind to TGF-β1 and TGF-β2 with a similar but somewhat less affinity than they bind BMP-2; that, as in the case of BMP-2, the full-length (FL) form of Spp24 binds TGF-β with greater affinity than do the truncation products; that FL-Spp24 inhibits TGF-β2 induced bone formation in vivo, but Spp14.5 does not; and that co-administration of FL-Spp24 or Spp14.5 with TGF-β2 in vivo is associated with a reduction in the amount of cartilage, relative to new bone, present at the site of injection. This finding is consistent with the observation that low-dose TGF-β administration in vivo is associated with greater bone formation than high-dose TGF-β administration, and suggests that one function of Spp24 and its truncation products is to down-regulate local TGF-β activity or availability during bone growth and development. The similarities and differences of the interactions between Spp24 proteins and TGF-β compared to the interaction of the Spp24 proteins and BMPs have significant implications with respect to the regulation of bone metabolism and with respect to engineering therapeutic proteins for skeletal disorders. Š 2013 Tian et al

    Bone Morphogenetic Protein-2 Promotes Osteosarcoma Growth by Promoting Epithelial-Mesenchymal Transition (EMT) Through the Wnt/b-Catenin Signaling Pathway

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    The correlation between BMP-2 and osteosarcoma growth has gained increased interest in the recent years, however, there is still no consensus. In this study, we tested the effects of BMP-2 on osteosarcoma cells through both in vitro and in vivo experiments. The effect of BMP-2 on the proliferation, migration and invasion of osteosarcoma cells was tested in vitro. Subcutaneous and intratibial tumor models were used for the in vivo experiments in nude mice. The effects of BMP-2 on EMT of osteosarcoma cells and the Wnt/β-catenin signaling pathway were also tested using a variety of biochemical methods. In vitro tests did not show a significant effect of BMP-2 on tumor cell proliferation. However, BMP-2 increased the mobility of tumor cells and the invasion assay demonstrated that BMP-2 promoted invasion of osteosarcoma cells in vitro. In vivo animal study showed that BMP-2 dramatically enhanced tumor growth. We also found that BMP-2 induced EMT of osteosarcoma cells. The expression levels of Axin2 and Dkk-1 were both down regulated by BMP-2 treatment, while β-catenin, c-myc and Cyclin-D1 were all upregulated. The expression of Wnt3α and p-GSK-3β were also significantly upregulated indicating that the Wnt/β-catenin signaling pathway was activated during the EMT of osteosarcoma driven by BMP-2. From this study, we can conclude that BMP-2 significantly promotes growth of osteosarcoma cells (143B, MG63), and enhances mobility and invasiveness of tumor cells as demonstrated in vitro. The underlying mechanism might be that BMP-2 promotes EMT of osteosarcoma through the Wnt/β-catenin signaling pathway. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1638–1648, 2019. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc

    Repeatedly Northwards and Upwards: Southern African Grasslands Fuel the Colonization of the African Sky Islands in Helichrysum (Compositae)

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    The Afromontane and Afroalpine areas constitute some of the main biodiversity hotspots of Africa. They are particularly rich in plant endemics, but the biogeographic origins and evolutionary processes leading to this outstanding diversity are poorly understood. We performed phylogenomic and biogeographic analyses of one of the most species-rich plant genera in these mountains, Helichrysum (Compositae-Gnaphalieae). Most previous studies have focused on Afroalpine elements of Eurasian origin, and the southern African origin of Helichrysum provides an interesting counterexample. We obtained a comprehensive nuclear dataset from 304 species (≈50% of the genus) using target-enrichment with the Compositae1061 probe set. Summary-coalescent and concatenation approaches combined with paralog recovery yielded congruent, well-resolved phylogenies. Ancestral range estimations revealed that Helichrysum originated in arid southern Africa, whereas the southern African grasslands were the source of most lineages that dispersed within and outside Africa. Colonization of the tropical Afromontane and Afroalpine areas occurred repeatedly throughout the Miocene-Pliocene. This timing coincides with mountain uplift and the onset of glacial cycles, which together may have facilitated both speciation and intermountain gene flow, contributing to the evolution of the Afroalpine flora.This work received financial support from the Spanish Ministry of Science, Innovation and Universities (PID2019-105583GB-C22/AEI/10.13039/501100011033) and the Catalan government (“Ajuts a grups consolidats” 2021SGR00315 and FI grant to C.B.-G. 2022FI_B 00150). The Ph.D. thesis was carried out under the Ph.D. program “Plant Biology and Biotechnology” of the Autonomous University of Barcelona (UAB). Additional support was provided by the Czech Science Foundation GAČR project no. 20-10878S to R.S. and F.K. and long-term research development project (RVO 67985939) of the Czech Academy of Sciences. Additional funds were obtained from the Norwegian Programme for Development, Research and Higher Education (NUFU; project AFROALP-II, no 2007/1058) and the Research Council of Norway (project SpeciationClock, no 274607) to C.B.Abstract 1. Introduction 2. Materials and Methods 2.1. Taxon Sampling 2.2. DNA Extraction, Library Preparation, Target Capture, and Sequencing 2.3. Molecular Data Processing and Phylogenetic Analyses 2.4. Divergence Time Estimation 2.5. Ancestral Range Estimation 3. Results 3.1. Alignment Processing and Filtering 3.2. Phylogenetic Analyses 3.3. Divergence Time and Ancestral Range Estimation 3.4. Number, Type, and Directionality Estimation of Biogeographical Events 4. Discussion 4.1. Utility of Target-Enrichment Strategies in Reconstructing the Radiation of Helichrysum 4.2. The Early History of Helichrysum and Colonization of Madagascar 4.3. Repeatedly Northwards 4.4. Repeatedly Upwards 5. Conclusions Supplementary Materials Author Contributions Funding Data Availability Statement Acknowledgments Conflicts of Interest Reference

    Measurement of the top quark mass using the matrix element technique in dilepton final states

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    We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7  fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84  GeV

    Integrating climate adaptation, water governance and conflict management policies in lake riparian zones: insights from African drylands

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    As river basin authorities and national governments develop policies to achieve sustainable development outcomes, conflicting signals between existing policies are undermining cross-thematic integrative modes of policy planning. This raises fundamental questions over how coherent portfolios of policy interventions across vital themes can best be advanced and managed. Taking the Lake Chad Basin (LCB) as an empirical example, we analyse transboundary policies and intervention documents relating to climate adaptation, water governance and conflict management to ascertain the interdependencies at the adaptation-water-peace nexus. Using a Qualitative Document Analysis (QDA) approach and a set of subjective integration scoring criteria, we assess whether and how integration is planned, setting out ways forward for mutually beneficial integration actions.Despite recent progress in addressing lake drying and recognising cross-thematic challenges, most LCB intervention plans continue to adopt standalone basin-scale agendas and seldom consider action plan preparedness based on local-level assessments. Analysis of a few (existing) cross-thematic, well-integrated initiatives indicates that the timings of societal challenges and funding arrangements appear to play a key role in shaping policy strategies, the manner in which climate adaptation, water or security are treated and the level of integration attained. Based on the notion that integration is inherently desirable, we suggest a new ‘policy integration thinking’ that embraces a development landscape logic and balances short-term and long-term development priorities

    Evolutionary winners are ecological losers among oceanic island plants

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    Aim Adaptive radiation, in which successful lineages proliferate by exploiting untapped niche space, provides a popular but potentially misleading characterization of evolution on oceanic islands. Here we analyse the respective roles of members of in situ diversified vs. non-diversified lineages in shaping the main ecosystems of an archipelago to explore the relationship between evolutionary and ecological ‘success’. Location Canary Islands. Taxon Vascular plants. Methods We quantified the abundance/rarity of the native flora according to the geographical range (number of islands where present and geographical extent of the range), habitat breadth (climatic niche) and local abundance (cover) using species distribution data based on 500 × 500 m grid cells and 2000 vegetation inventories located all over the archipelago. Results Species of diversified lineages have significantly smaller geographic ranges, narrower climatic niches and lower local abundances than those of non-diversified lineages. Species rarity increased with the degree of diversification. The diversified Canarian flora is mainly comprised by shrubs. At both archipelagic and island level, the four core ecosystems (Euphorbia scrub, thermophilous woodlands, laurel forest and pine forest) were dominated by non-diversified lineages species, with diversified lineages species providing <25% cover. Species of diversified lineages, although constituting 54% of the archipelagic native flora, were only abundant in two rare ecosystems: high mountain scrub and rock communities. Main conclusions Radiated species, endemic products of in situ speciation, are mostly rare in all three rarity axes and typically do not play an important role in structuring plant communities on the Canaries. The vegetation of the major ecosystem types is dominated by plants representing non-diversified lineages (species that derive from immigration and accumulation), while species of evolutionarily successful lineages are abundant only in marginal habitats and could, therefore, be considered ecological losers. Within this particular oceanic archipelago, and we posit within at least some others, evolutionary success in plants is accomplished predominantly at the margins.publishedVersio
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