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21.
Although riverine carbon fluxes are a minor component of the global carbon cycle, thetransfer of organic carbon from land to ocean represents a flux of potential carbon storage, irre-versible over 10~3 to 10~4 a. Future carbon transfers through river basins are expected to accelerate,with respect to both sources and sinks, because of the large-scale human driven land-use and land-cover changes. Thus, the increased amounts of carbon transported to and sequestered inmarine sediments (through fertilization by river-borne inorganic nutrients) may be an important netsink for anthropogenic CO_2. Particularly, the humid tropics of South Asia are regions very sensitiveto this lateral C transport because of high precipitation and high rates of land use and cover change. In this paper we report on the role of upland tributaries in the transport processes influ-encing the lateral carbon and nitrogen fluxes of the Godavari, a large tropical river of India. By far,dissolved inorganic carbon (DIC) is the dominant form of carbon transport in the river basin. It con-stitutes as much as 75% to the total carbon load. Particulate and dissolved organic carbon (POC and DOC) fluxes account for 21% and 4%, respectively. In the upper basin, DOC fluxes exceedthat of POC due to large-scale anthropogenic activities. In contrast, tributaries in the central basinare characterized by comparable fluxes of POC and DOC. However, downriver POC export is 35%less than the import from upriver and tributaries due to the entrainment of sediments in river channels and dam sites. We argue that for highly disturbed watersheds in tropical regions, down-stream transport of sediments and carbon requires long-term sampling programmes. 相似文献
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Surya Sudheer Zain Taha Sivakumar Manickam Asgar Ali Poh Guat Cheng 《Fungal biology》2018,122(5):293-301
Following the importance of antler-type fruiting bodies of Ganoderma lucidum, in this study, the impact of main growth parameters such as ventilation and light on the development of antler-type fruiting bodies has been investigated together with the determination of physico-chemical properties of antler fruiting bodies. For this, the primordia bags of G. lucidum were kept under controlled ventilation to adjust the CO2 produced by the mushrooms owing to its respiration under light and dark conditions. The bioactive compounds such as phenolics, flavonoids, water-soluble polysaccharides and ganoderic acid showed a two-fold increase in the antler-type fruiting bodies as compared to normal kidney-shaped fruiting bodies. It is assumed from this study that the antler type fruiting bodies are developed due to restricted ventilation which causes an increase in the level of CO2 gas in the air as a result of respiration of mushroom. The shape and colour of antler fruiting bodies again dependent on the light provided in the growth chamber. This study also proves that with the manipulation of light and ventilation antler-type fruiting bodies of G. lucidum could be developed with higher quantity of bioactive compounds and with higher antioxidant potential. 相似文献
23.
Although riverine carbon fluxes are a minor component of the global carbon cycle, the transfer of organic carbon from land to ocean represents a flux of potential carbon storage, irreversible over 103 to 104 a. Future carbon transfers through river basins are expected to accelerate, with respect to both sources and sinks, because of the large-scale human driven land-use and land-cover changes. Thus, the increased amounts of carbon transported to and sequestered in marine sediments (through fertilization by river-borne inorganic nutrients) may be an important net sink for anthropogenic CO2. Particularly, the humid tropics of South Asia are regions very sensitive to this lateral C transport because of high precipitation and high rates of land use and cover change. In this paper we report on the role of upland tributaries in the transport processes influencing the lateral carbon and nitrogen fluxes of the Godavari, a large tropical river of India. By far, dissolved inorganic carbon (DIC) is the dominant form of carbontransport in the river basin. It constitutes as much as 75% to the total carbonload. Particulate and dissolved organic carbon (POC and DOC) fluxes account for21% and 4%, respectively. In the upper basin, DOC fluxes exceed that of POC dueto large-scale anthropogenic activities. In contrast, tributaries in the central basin are characterized by comparable fluxes of POC and DOC. However, downriver POC export is 35% less than the import from upriver and tributaries due to theentrainment of sediments in river channels and dam sites. We argue that for highly disturbed watersheds in tropical regions, downstream transport of sediments and carbon requires long-term sampling programmes. 相似文献
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Mitochondrial dysfunction and oxidative stress in the pathogenesis of alcohol- and obesity-induced fatty liver diseases 总被引:6,自引:1,他引:5
Mantena SK King AL Andringa KK Eccleston HB Bailey SM 《Free radical biology & medicine》2008,44(7):1259-1272
Fatty liver disease associated with chronic alcohol consumption or obesity/type 2 diabetes has emerged as a serious public health problem. Steatosis, accumulation of triglyceride in hepatocytes, is now recognized as a critical "first-hit" in the pathogenesis of liver disease. It is proposed that steatosis "primes" the liver to progress to more severe liver pathologies when individuals are exposed to subsequent metabolic and/or environmental stressors or "second-hits." Genetic risk factors can also influence the susceptibility to and severity of fatty liver disease. Furthermore, oxidative stress, disrupted nitric oxide (NO) signaling, and mitochondrial dysfunction are proposed to be key molecular events that accelerate or worsen steatosis and initiate progression to steatohepatitis and fibrosis. This review article will discuss the following topics regarding the pathobiology and molecular mechanisms responsible for fatty liver disease: (1) the "two-hit" or "multi-hit" hypothesis, (2) the role of mitochondrial bioenergetic defects and oxidant stress, (3) the interplay between NO and mitochondria in fatty liver disease, (4) genetic risk factors and oxidative stress-responsive genes, and (5) the feasibility of antioxidants for treatment. 相似文献
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Rajesh Kumar Singh D. Praveen Kumar Pratiksha Singh Manoj Kumar Solanki Supriya Srivastava Prem Lal Kashyap Sudheer Kumar Alok K. Srivastava Pradeep K. Singhal Dilip K. Arora 《Plant Growth Regulation》2014,73(1):91-101
Wilt and root rot are the major constraints in chickpea production and very difficult to manage through agrochemicals. Hence, for an ecofriendly and biological management, 240 strains of Bacillus and Bacillus derived genera were isolated from chickpea rhizosphere, further narrowed down to 14 strains on the basis of in vitro production of indole acetic acid, siderophore, phosphate solubilization, hydrolytic enzymes and were evaluated for antagonism against chickpea pathogens (Fusarium oxysporum f. sp. ciceri race 1, F. solani and Macrophomina phaseolina). The strains were identified on the basis of physiological characters and 16S RNA gene sequencing. The genotypic comparisons of strains were determined by BOX-polymerase chain reaction profiles and amplified rDNA restriction analysis. These isolates were evaluated in greenhouse assay in which B. subtilis (B-CM191, B-CV235, B-CL-122) proved to be effective in reducing wilt incidence and significant enhancement in growth (root and shoot length) and dry matter of chickpea plants. PCR amplification of bacillomycin (bmyB) and β-glucanase genes suggests that amplified genes from the Bacillus could have a role to further define the diversity, ecology, and biocontrol activities in the suppression of soil-borne pathogens. 相似文献
27.
Chibueze A. Ihunnah Taira Wada Brian J. Philips Sudheer K. Ravuri Robert B. Gibbs Levent Kirisci J. Peter Rubin Kacey G. Marra Wen Xie 《Molecular and cellular biology》2014,34(9):1682-1694
Estrogen sulfotransferase (EST/SULT1E1) is known to catalyze the sulfoconjugation and deactivation of estrogens. The goal of this study is to determine whether and how EST plays a role in human adipogenesis. By using human primary adipose-derived stem cells (ASCs) and whole-fat tissues from the abdominal subcutaneous fat of obese and nonobese subjects, we showed that the expression of EST was low in preadipocytes but increased upon differentiation. Overexpression and knockdown of EST in ASCs promoted and inhibited differentiation, respectively. The proadipogenic activity of EST in humans was opposite to the antiadipogenic effect of the same enzyme in rodents. Mechanistically, EST promoted adipogenesis by deactivating estrogens. The proadipogenic effect of EST can be recapitulated by using an estrogen receptor (ER) antagonist or ERα knockdown. In contrast, activation of ER in ASCs inhibited adipogenesis by decreasing the recruitment of the adipogenic peroxisome proliferator-activated receptor γ (PPARγ) onto its target gene promoters, whereas ER antagonism increased the recruitment of PPARγ to its target gene promoters. Linear regression analysis revealed a positive correlation between the expression of EST and body mass index (BMI), as well as a negative correlation between ERα expression and BMI. We conclude that EST is a proadipogenic factor which may serve as a druggable target to inhibit the turnover and accumulation of adipocytes in obese patients. 相似文献
28.
Jatropha curcas L. (Euphorbiaceae) has acquired a great importance as a renewable source of energy with a number of environmental benefits. Very few attempts were made to understand the extent of genetic diversity and its distribution. This study was aimed to study the diversity and deduce the phylogeography of Jatropha curcas L. which is said to be the most primitive species of the genus Jatropha. Here we studied the intraspecific genetic diversity of the species distributed in different parts of the globe. The study also focused to understand the molecular diversity at reported probable center of origin (Mexico), and to reveal the dispersal route to other regions based on random amplified polymorphic DNA, amplified fragment length polymorphism and nrDNA-ITS sequences data. The overall genetic diversity of J. curcas found in the present study was narrow. The highest genetic diversity was observed in the germplasm collected from Mexico and supports the earlier hypothesis based on morphological data and natural distribution, it is the center for origin of the species. Least genetic diversity found in the Indian germplasm and clustering results revealed that the species was introduced simultaneously by two distinct germplasm and subsequently distributed in different parts of India. The present molecular data further revealed that J. curcas might have spread from the center of the origin to Cape Verde, than to Spain, Portuguese to other neighboring countries and simultaneously to Africa. The molecular evidence supports the Burkill et al. (A dictionary of the economic products of the Malay Peninsula, Governments of Malaysia and Singapore by the Ministry of Agriculture and Co-operatives. Kuala Lumpur, Malaysia, 1966) view of Portuguese might have introduced the species to India. The clustering pattern suggests that the distribution was interfered by human activity. 相似文献
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Amod D. Kulkarni Viswanath Kiron Jan H. W. M. Rombout Monica F. Brinchmann Jorge M. O. Fernandes Naduvilamuriparampu S. Sudheer Bright I. S. Singh 《Proteomics》2014,14(13-14):1660-1673
White spot syndrome virus (WSSV) is a pathogen that causes considerable mortality of the farmed shrimp, Penaeus monodon. Candidate ‘vaccines’, WSSV envelope protein VP28 and formalin‐inactivated WSSV, can provide short‐lived protection against the virus. In this study, P. monodon was orally intubated with the aforementioned vaccine candidates, and protein expression in the gut of immunised shrimps was profiled. The alterations in protein profiles in shrimps infected orally with live‐WSSV were also examined. Seventeen of the identified proteins in the vaccine and WSSV‐intubated shrimps varied significantly compared to those in the control shrimps. These proteins, classified under exoskeletal, cytoskeletal, immune‐related, intracellular organelle part, intracellular calcium‐binding or energy metabolism, are thought to directly or indirectly affect shrimp's immunity. The changes in the expression levels of crustacyanin, serine proteases, myosin light chain, and ER protein 57 observed in orally vaccinated shrimp may probably be linked to immunoprotective responses. On the other hand, altered expression of proteins linked to exoskeleton, calcium regulation and energy metabolism in WSSV‐intubated shrimps is likely to symbolise disturbances in calcium homeostasis and energy metabolism. 相似文献