Ooi and Liu (2000) reported that protein-bound polysaccharide (PBP) and polysaccharide peptide were able to mimic the endogenous antioxidant superoxide dismutase (SOD) in cancer-bearing animals in vivo. These polysaccharides were also reported to protect the immune cells from oxidative damage (Ooi and Lui 2000). The protective effects of G. lucidum on DNA strand scission induced by a metal-catalyzed Fenton reaction, ultraviolet irradiation, and hydroxyl radical attack were shown in agarose gel electrophoresis in vitro (Lee et al. 2001). Hot water extracts of G. lucidum significantly protected Raji cells from hydrogen peroxide (H2O2)-induced DNA damage (Shi et al. 2002). Hot water extracts protected human lymphocyte DNA only at low (.01% w/v) (Wachtel-Galor, Choi, and Benzie 2005). Two antioxidant-enriched extracts from G. lucidum acted oppositely in premalignant HUC-PC cells under carcinogenic attack (Yuen and Gohel 2008). The aqueous extract protected cellular DNA from oxidative damage, whereas the ethanolic extract damaged cellular DNA, with increased H2O2 production and significant cell-killing effects observed. The results suggested that different effects of G. lucidum could be exhibited by different extractable components in bladder chemoprevention. Methanol extracts of G. lucidum were reported to prevent kidney damage (induced by the anticancer drug cisplatin) through restoration of the renal antioxidant defense system (Sheena, Ajith, and Janardhanan 2003). In contrast, a fraction of ganoderma triterpenes (GTS) was found to enhance the intracellular reactive oxygen species (ROS)-producing effect of doxorubicin (DOX) in Hela cells, leading to more DNA damage and apoptosis, whereas such synergism was inhibited by a ROS scavenger (Yue et al. 2008). In an animal study (diabetic rats), nonenzymic and enzymic antioxidants levels increased and lipid peroxidation levels decreased with G. lucidum treatment (Jia et al. 2009). However, a direct link has not been established between the antioxidant properties of G. lucidum and its immunomodulatory and anticancer effects, and whether lingzhi acts as an antioxidant or pro-oxidant may depend on concentration and environment.
GM SI Service Information 1980 Through 2009 Download Pc
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In a more recent study, oral administration of G. lucidum hot water extract (0.03 and 0.3 g/kg BW) for 4 weeks was found to lower the serum glucose levels in obese/diabetic (+db/+db) mice, with effects seen after the first week of treatment (Seto et al. 2009). However, the glucose levels were still higher in these animals than in the control animals, and insulin levels were not altered. The extract markedly reduced levels of phosphoenol-pyruvate carboxykinase (PEPCK), which are usually high in obese/diabetic mice. The suggested mechanism, according to the authors, is that of lowering the serum glucose levels through suppression of the hepatic PEPCK gene expression. In another study (Jia et al. 2009), a polysaccharides-rich extract showed beneficial effects in streptozotocin-induced diabetic rats. The diabetic rats were treated with G. lucidum for 30 days. Following the treatment, serum insulin levels increased (compared with the nontreated diabetic group) and glucose levels decreased in a dose-dependent way. Treatment with streptozotocin also elevated levels of lipid peroxidation markers (thiobarbituric acid reactive substances [TBARS]), lipid hydroperoxides, and conjugated dienes); decreased levels of nonenzymic antioxidants (vitamin C, reduced glutathione [GSH] vitamin E); and decreased activities of the antioxidant enzymes, SOD, catalase, and glutathione peroxidase (Gpx). Following treatment with GL-PSs, levels of nonenzymic and enzymic antioxidants increased and lipid peroxidation levels decreased. Therefore, in addition to its glycemic modulation, treatment with G. lucidum helped to decrease oxidative stress (Jia et al. 2009).
This study takes an historical approach in order to establish how the form and function of the social-ecological system that represents the Bangladesh south-western coastal zone has changed over recent decades. Time series data for a range of ecosystem services and drivers are analysed to define the range of trends, the presence of change points, slow and fast variables and the significant drivers of change. Since the 1980s, increasing gross domestic product and per capita income mirror rising levels of food and inland fish production. As a result, the size of population below the poverty line has reduced by 17 %. In contrast, non-food ecosystem services such as water availability, water quality and land stability have deteriorated. Conversion of rice fields to shrimp farms is almost certainly a factor in increasing soil and surface water salinity. Most of the services experienced statistically significant change points between 1975 and 1980, and among the services, water availability, shrimp farming and maintenance of biodiversity appear to have passed tipping points. An environmental Kuznets curve analysis suggests that the point at which growing economic wealth feeds back into effective environmental protection has not yet been reached for water resources. Trends in indicators of ecosystem services and human well-being point to widespread non-stationary dynamics governed by slowly changing variables with an increased likelihood of systemic threshold changes/tipping points in the near future. The results will feed into simulation models and strategies that can define alternative and sustainable paths for land management.
In this study, we develop further the co-evolutionary approach through description and analysis of multi-decadal changes in social, economic and biophysical variables for a region where the need for enhanced management tools is pressing: the coastal zone of south-west Bangladesh. Our main aim is to use that information to infer the rates and direction of change, the possible existence of transgressed thresholds, the changes in system resilience and the long-term relationship between poverty alleviation and environmental degradation as a foundation for further studies on the social-ecological links and modelling of appropriate management practices.
Bivariate plots (Figs. 5, 6) show the association between rising food provisioning services, rising GDP and poverty alleviation. Figure 5 shows that rising agricultural production is coupled with poverty alleviation that is also evident in other countries (e.g. Niger, Afghanistan and Mexico) (WB 2013). But it is also possible to explore the links between rising GDP, a measure of economic growth, and environmental quality. Environmental Kuznets curves are simple bivariate plots showing the relationship between economic wealth and environmental quality through time (e.g. Beckerman 1992). A bivariate plot (Fig. 7) of relative GDP against an index for water quality degradation (surface water salinity) in the BCZ shows that water resources have deteriorated as the Bangladesh economy has grown. In many middle- and high-income countries, the level of environmental degradation slows and reduces as GDP allows for investment in environmental remediation and protection measures. But in the BCZ, there is no indication that this turning point has been reached.
But is a turning point possible? Direct actions to reduce degradation could include greater control on water quality through stronger regulation on the extent and practice of shrimp farming and on the exploitation of the mangroves. But external controls on river discharge and regional climate may mean that these can only be partially successful. Proactive adaptive strategies for managing agriculture, such as through the introduction of new crop hybrids, might also be introduced although the dependence of T-Aman rice on irrigated water, obtained from declining resources, highlights the challenge of overcoming one problem without creating new ones or relying on environmental elements already stressed. The combined evidence from this study for declining resilience, possible tipping points and observable positive feedback mechanisms suggests growing unsustainability across the whole social-ecological system (cf. Zhang et al. 2015). Therefore, it is not unreasonable to suggest that a continuation of environmental degradation and losses of regulating services could eventually drive declines in rice, shrimp and fish production. This would impact first on rural poor farmers dependent on wage income or subsistence products, and gradually the larger landowners and associated processing industries. In time, a partial environmental improvement might occur as land became less intensively used. But in this scenario, it is unlikely that regional economic growth based on agriculture would continue. Rather than economic growth constraining environmental degradation, there would be a reversal or upturn of the Kuznets curve towards an earlier stage of development (cf. Liu 2012). Such a bleak prospect calls for the rapid involvement of scientists, stakeholders and politicians to negotiate a management plan for the BCZ.
There are multiple drivers of these changes in ecosystem services that range from global climate change and new agricultural methods to specific infrastructural developments (e.g. the Farakka barrage and polders), and local-policy-driven actions (e.g. commercial shrimp farming). Most of the ecosystem services and well-being have experienced change points around 1980s, where water availability, shrimp farming and maintenance of biodiversity have passed tipping points. 2ff7e9595c
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