165 research outputs found
Large scale simulation of watershed mass transport – a case study of Tsengwen reservoir watershed
The Tenth International Symposium on Mitigation of Geo-disasters in Asia Matsue Symposium Place: Shimane Civil Center, Matsue Date: 8 October 2012We present the large scale simulation of watershed mass transport, including landslide, debris-flow and sediment transport. A case study of Tsengwen reservoir watershed under the extreme rainfall triggered by typhoon Morakot is simulated for verification. This approach starts with volume-area relationship formula with inventory method to predict temporal and regional landslide volume production and distribution. Then, debris flow model, Debris-2D, is used to simulate the mass transport of debris-flow from hillslope to fluvial channel. Finally a sediment transport model, NETSTARS, is used for hydraulic and sediment routing in river and reservoir. The integrated simulation for the whole watershed gives a very good agreement with the temporal variation of sediment concentration recorded at the very downstream location
Plant and fungal products that extend lifespan in caenorhabditis elegans
The nematode Caenorhabditis elegans is a useful model to study aging due to its short lifespan, ease of manipulation, and available genetic tools. Several molecules and extracts derived from plants and fungi extend the lifespan of C. elegans by modulating aging-related pathways that are conserved in more complex organisms. Modulation of aging pathways leads to activation of autophagy, mitochondrial biogenesis and expression of antioxidant and detoxifying enzymes in a manner similar to caloric restriction. Low and moderate concentrations of plant and fungal molecules usually extend lifespan, while high concentrations are detrimental, consistent with a lifespan-modulating mechanism involving hormesis. We review here molecules and extracts derived from plants and fungi that extend the lifespan of C. elegans, and explore the possibility that these natural substances may produce health benefits in humans
Plant and fungal products that extend lifespan in caenorhabditis elegans
The nematode Caenorhabditis elegans is a useful model to study aging due to its short lifespan, ease of manipulation, and available genetic tools. Several molecules and extracts derived from plants and fungi extend the lifespan of C. elegans by modulating aging-related pathways that are conserved in more complex organisms. Modulation of aging pathways leads to activation of autophagy, mitochondrial biogenesis and expression of antioxidant and detoxifying enzymes in a manner similar to caloric restriction. Low and moderate concentrations of plant and fungal molecules usually extend lifespan, while high concentrations are detrimental, consistent with a lifespan-modulating mechanism involving hormesis. We review here molecules and extracts derived from plants and fungi that extend the lifespan of C. elegans, and explore the possibility that these natural substances may produce health benefits in humans
EBV-positive Hodgkin lymphoma is associated with suppression of p21cip1/waf1 and a worse prognosis
<p>Abstract</p> <p>Background</p> <p>About 30-50% of Hodgkin lymphomas (HLs) harbor the Epstein-Barr virus (EBV), but the impact of EBV infection on clinical outcomes has been unclear. EBV-encoded small RNAs (<it>EBER</it>s) are presented in all EBV-infected cells, but their functions are still less understood.</p> <p>Results</p> <p><it>EBER1 </it>was transfected into two HL cell lines, KMH2 and L428, and microarrays were used to screen for <it>EBER1</it>-induced changes. We found that <it>EBER1 </it>suppressed <it>p21</it><sup>cip1/waf1 </sup>transcription in HL cell lines. In addition, positive regulators of <it>p21</it><sup>cip1/waf1 </sup>transcription, such as p53, EGR1, and STAT1, were decreased. Suppression of <it>p21</it><sup>cip1/waf1 </sup>in the <it>EBER1</it><sup>+ </sup>HL cell lines was associated with increased resistance to histone deacetylase inhibitors or proteasome inhibitors, drugs known to cause apoptosis by increasing p21<sup>cip1/waf1 </sup>levels. On biopsy specimens, EBV<sup>+ </sup>HLs had weaker expression of both p21<sup>cip1/waf1 </sup>and active caspase 3. Clinically, suppression of p21<sup>cip1/waf1 </sup>in EBV<sup>+ </sup>HLs was associated with a worse 2-year disease-free survival rate (45% for EBV<sup>+ </sup>HLs <it>vs</it>. 77% for EBV<sup>- </sup>HLs, <it>p </it>= 0.002).</p> <p>Conclusion</p> <p>Although the underlying mechanisms are still relatively unclear, <it>EBER1 </it>inhibits <it>p21</it><sup>cip1/waf1 </sup>transcription and prevents apoptosis through down-regulation of p53, EGR1, and STAT1. The anti-apoptotic activity of <it>EBER1 </it>may be important in the rescue of Reed-Sternberg cells from drug-induced apoptosis and in the clinical behaviors of EBV<sup>+ </sup>HLs.</p
Successes and failures in language planning for European languages in Asian nations
Although there have been some attempts to examine language planning and its successes and failures in South and East Asian languages, especially as such planning relates to English and to other European languages, no systematic cross-national study is available that looks systemati-cally at these issues. While such a study is not possible within the limits imposed by this paper – a monograph would probably be needed; we attempt to sketch the broad outlines of what such a study might look like and provide some basic data about, and examples of the successful and more problematic language policy and planning that has occurred in this region. If we look beyond the large regional languages (e.g., Bengali, Chinese, Japanese, Javanese, Korean, and more recently Malay/Indonesian and Filipino) and the multitude of minority lan-guages, we find European – and of course Arabic and other Asian languages – have become es-tablished in the various polities in the region. These languages have come to be used for a number of reasons, including: •Trade internally within the region, from the Arabian peninsula, and later from Europe (Dutch, English, French, German, Italian, Portuguese, Russian, Spanish); •Religious proselytisation conducted through Arabic and various European languages; •Colonization, as conducted through various European (and Asian) languages; •Languages learned to access overseas education and technology; •Wars of aggression, some of which were linked to European, North American, and Asian colonial development; •The geopolitics of the “cold war”, especially for Russian and English; and •The rise of English as an economic world language or lingua franca
Ganoderma Lucidum Stimulates Autophagy-Dependent Longevity Pathways in Caenorhabditis Elegans and Human Cells
The medicinal fungus Ganoderma lucidum is used as a dietary supplement and health tonic, but whether it affects longevity remains unclear. We show here that a water extract of G. lucidum mycelium extends lifespan of the nematode Caenorhabditis elegans. The G. lucidum extract reduces the level of fibrillarin (FIB-1), a nucleolar protein that correlates inversely with longevity in various organisms. Furthermore, G. lucidum treatment increases expression of the autophagosomal protein marker LGG-1, and lifespan extension is abrogated in mutant C. elegans strains that lack atg-18, daf-16, or sir-2.1, indicating that autophagy and stress resistance pathways are required to extend lifespan. In cultured human cells, G. lucidum increases concentrations of the LGG-1 ortholog LC3 and reduces levels of phosphorylated mTOR, a known inhibitor of autophagy. Notably, low molecular weight compounds (\u3c10 kDa) isolated from the G. lucidum water extract prolong lifespan of C. elegans and the same compounds induce autophagy in human cells. These results suggest that G. lucidum can increase longevity by inducing autophagy and stress resistance
P2RX7 Deletion in T Cells Promotes Autoimmune Arthritis by Unleashing the Tfh Cell Response
Rheumatoid arthritis (RA) is an autoimmune disease that affects ~1% of the world's population. B cells and autoantibodies play an important role in the pathogenesis of RA. The P2RX7 receptor is an ATP-gated cation channel and its activation results in the release of pro-inflammatory molecules. Thus, antagonists of P2RX7 have been considered to have potential as novel anti-inflammatory therapies. Although originally identified for its role in innate immunity, P2RX7 has recently been found to negatively control Peyer's patches (PP) T follicular helper cells (Tfh), which specialize in helping B cells, under homeostatic conditions. We have previously demonstrated that PP Tfh cells are required for the augmentation of autoimmune arthritis mediated by gut commensal segmented filamentous bacteria (SFB). Thus, we hypothesized that P2RX7 is required to control autoimmune disease by keeping the Tfh cell response in check. To test our hypothesis, we analyzed the impact of P2RX7 deficiency in vivo using both the original K/BxN autoimmune arthritis model and T cell transfers in the K/BxN system. We also examined the impact of P2RX7 ablation on autoimmune development in the presence of the gut microbiota SFB. Our data illustrate that contrary to exerting an anti-inflammatory effect, P2RX7 deficiency actually enhances autoimmune arthritis. Interestingly, SFB colonization can negate the difference in disease severity between WT and P2RX7-deficient mice. We further demonstrated that P2RX7 ablation in the absence of SFB caused reduced apoptotic Tfh cells and enhanced the Tfh response, leading to an increase in autoantibody production. It has been shown that activation of TIGIT, a well-known T cell exhaustion marker, up-regulates anti-apoptotic molecules and promotes T cell survival. We demonstrated that the reduced apoptotic phenotype of P2rx7−/− Tfh cells is associated with their increased expression of TIGIT. This suggested that while P2RX7 was regulating the Tfh population by promoting cell death, TIGIT may have been opposing P2RX7 by inhibiting cell death. Together, these results demonstrated that systemic administration of general P2RX7 antagonists may have detrimental effects in autoimmune therapies, especially in Tfh cell-dependent autoimmune diseases, and cell-specific targeting of P2RX7 should be considered in order to achieve efficacy for P2RX7-related therapy
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Corrigendum: Ganoderma lucidum reduces obesity in mice by modulating the composition of the gut microbiota.
This corrects the article DOI: 10.1038/ncomms8489
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