174 research outputs found

    Soil rehabilitation in semi-arid Spain: Long-term effect of afforestation and land abandonment on soil quality

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    In response to the increasing amount of abandoned agricultural land in the European Mediterranean area during the last century, afforestation projects have been conducted as a measure for soil protection and ecosystem restoration. Despite the research on the impact and effectiveness of these projects, the long-term effect on soil quality has hardly been studied. Especially the linkage between soil physical, chemical and hydrological properties is lacking. An intensive fieldwork has been carried out in Murcia, southeastern Spain to study the effects of land abandonment and afforestation on soil quality along a chronosequence and included two afforested areas, planted with Pinus halepensis trees in the early ‘70s and ‘90s. Samples were taken to study changes in soil physical and chemical quality (e.g. Aggregate stability, Corg, N, P, K, Na), Soil Organic Carbon (SOC) stocks and soil hydrological properties, such as infiltration and water retention. A comparison was made between afforestation projects, abandoned agricultural plots of similar age, semi-natural vegetation and cereal crop fields. As the natural vegetation is characterized by a spotted pattern of bare areas and trees, forming so-called “islands of fertility”, both bare and vegetation covered sub-sites were included. Our results indicated that under secondary succession on abandoned fields, soil quality showed a marginal non-linear improvement over the studied period. The afforestation showed a much more pronounced linear increase, resulting in a soil quality comparable to what can be found under semi-natural vegetation. After 40 years afforestation showed to be successful in the restoration of the natural soil hydrological functioning, while the abandoned sites only indicated small changes. For this case study, in semiarid areas, afforesting is the best way forward as it has a clear effect on enhancing soil quality compared to secondary succession on abandoned agricultural fields

    К разработке технологии возведения геокомпозитных охранных систем горных выработок

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    У статті розглянуто відмінності використання особливо тонко дисперсних в’яжучих (ОТДВ) у підземних умовах для створення елементів геокомпозитних конструкцій.In article the differences of the use especially thinly of dispersible astringent are considered in underground terms for creation elements of geocomposit constructions

    Orthopedic surgery increases atherosclerotic lesions and necrotic core area in ApoE-/- mice

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    Background and aims Observational studies show a peak incidence of cardiovascular events after major surgery. For example, the risk of myocardial infarction increases 25-fold early after hip replacement. The acuteness of this increased risk suggests abrupt enhancement in plaque vulnerability, which may be related to intra-plaque inflammation, thinner fibrous cap and/or necrotic core expansion. We hypothesized that acute systemic inflammation following major orthopedic surgery induces such changes. Methods ApoE−/− mice were fed a western diet for 10 weeks. Thereafter, half the mice underwent mid-shaft femur osteotomy followed by realignment with an intramedullary K-wire, to mimic major orthopedic surgery. Mice were sacrificed 5 or 15 days post-surgery (n = 22) or post-saline injection (n = 13). Serum amyloid A (SAA) was measured as a marker of systemic inflammation. Paraffin embedded slides of the aortic root were stained to measure total plaque area and to quantify fibrosis, calcification, necrotic core, and inflammatory cells. Results Surgery mice showed a pronounced elevation of serum amyloid A (SAA) and developed increased plaque and necrotic core area already at 5 days, which reached significance at 15 days (p = 0.019; p = 0.004 for plaque and necrotic core, respectively). Macrophage and lymphocyte density significantly decreased in the surgery group compared to the control group at 15 days (p = 0.037; p = 0.024, respectively). The density of neutrophils and mast cells remained unchanged. Conclusions Major orthopedic surgery in ApoE−/− mice triggers a systemic inflammatory response. Atherosclerotic plaque area is enlarged after surgery mainly due to an increase of the necrotic core. The role of intra-plaque inflammation in this response to surgical injury remains to be fully elucidated. © 2016 Elsevier Ireland Lt

    Regenerating zebrafish scales express a subset of evolutionary conserved genes involved in human skeletal disease

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    BACKGROUND: Scales are mineralised exoskeletal structures that are part of the dermal skeleton. Scales have been mostly lost during evolution of terrestrial vertebrates whilst bony fish have retained a mineralised dermal skeleton in the form of fin rays and scales. Each scale is a mineralised collagen plate that is decorated with both matrix-building and resorbing cells. When removed, an ontogenetic scale is quickly replaced following differentiation of the scale pocket-lining cells that regenerate a scale. Processes promoting de novo matrix formation and mineralisation initiated during scale regeneration are poorly understood. Therefore, we performed transcriptomic analysis to determine gene networks and their pathways involved in dermal scale regeneration. RESULTS: We defined the transcriptomic profiles of ontogenetic and regenerating scales of zebrafish and identified 604 differentially expressed genes (DEGs). These were enriched for extracellular matrix, ossification, and cell adhesion pathways, but not in enamel or dentin formation processes indicating that scales are reminiscent to bone. Hypergeometric tests involving monogenetic skeletal disorders showed that DEGs were strongly enriched for human orthologues that are mutated in low bone mass and abnormal bone mineralisation diseases (P< 2× 10(−3)). The DEGs were also enriched for human orthologues associated with polygenetic skeletal traits, including height (P< 6× 10(−4)), and estimated bone mineral density (eBMD, P< 2× 10(−5)). Zebrafish mutants of two human orthologues that were robustly associated with height (COL11A2, P=6× 10(−24)) or eBMD (SPP1, P=6× 10(−20)) showed both exo- and endo- skeletal abnormalities as predicted by our genetic association analyses; col11a2(Y228X/Y228X) mutants showed exoskeletal and endoskeletal features consistent with abnormal growth, whereas spp1(P160X/P160X) mutants predominantly showed mineralisation defects. CONCLUSION: We show that scales have a strong osteogenic expression profile comparable to other elements of the dermal skeleton, enriched in genes that favour collagen matrix growth. Despite the many differences between scale and endoskeletal developmental processes, we also show that zebrafish scales express an evolutionarily conserved sub-population of genes that are relevant to human skeletal disease. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12915-021-01209-8

    Early life glucocorticoid exposure modulates immune function in zebrafish (Danio rerio) larvae

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    In this study we have assessed the effects of increased cortisol levels during early embryonic development on immune function in zebrafish (Danio rerio) larvae. Fertilized eggs were exposed to either a cortisol-containing, a dexamethasone-containing (to stimulate the glucocorticoid receptor selectively) or a control medium for 6 h post-fertilization (0-6 hpf). First, we measured baseline expression of a number of immune-related genes (socs3a, mpeg1.1, mpeg1.2, andirg1l) 5 days post-fertilization (dpf) in larvae of the AB and TL strain to assess the effectiveness of our exposure procedure and potential strain differences. Cortisol and dexamethasone strongly up-regulated baseline expression of these genes independent of strain. The next series of experiments were therefore carried out in larvae of the AB strain only. We measured neutrophil/macrophage recruitment following tail fin amputation (performed at 3 dpf) and phenotypical changes as well as survival following LPS-induced sepsis (150 mu g/ml; 4-5 dpf). Dexamethasone, but not cortisol, exposure at 0-6 hpf enhanced neutrophil recruitment 4 h post tail fin amputation. Cortisol and dexamethasone exposure at 0-6 hpf led to a milder phenotype (e.g., less tail fin damage) and enhanced survival following LPS challenge compared to control exposure. Gene-expression analysis showed accompanying differences in transcript abundance oftlr4bb, cxcr4a, myd88, il1 beta, and il10. These data show that early-life exposure to cortisol, which may be considered to be a model or proxy of maternal stress, induces an adaptive response to immune challenges, which seems mediated via the glucocorticoid receptor.Animal science
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