Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues.Because of their prominent role in the global carbon balance and their possible rol...Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues.Because of their prominent role in the global carbon balance and their possible role in carbon sequestration, soil microbes are very important organisms in relation to global climate changes. This review focuses mainly on the responses of soil microbes to climate changes and subsequent effects on soil carbon dynamics. An overview table regarding extracellular enzyme activities(EAA) with all relevant literature data summarizes the effects of different ecosystems under various experimental treatments on EAA. Increasing temperature, altered soil moisture regimes, and elevated carbon dioxide significantly affect directly or indirectly soil microbial activities.High temperature regimes can increase the microbial activities which can provide positive feedback to climate change, whereas lower moisture condition in pedosystem can negate the increase, although the interactive effects still remain unanswered. Shifts in soil microbial community in response to climate change have been determined by gene probing, phospholipid fatty acid analysis(PLFA),terminal restriction length polymorphism(TRFLP), and denaturing gradient gel electrophoresis(DGGE), but in a recent investigations,omic technological interventions have enabled determination of the shift in soil microbe community at a taxa level, which can provide very important inputs for modeling C sequestration process. The intricacy and diversity of the soil microbial population and how it responds to climate change are big challenges, but new molecular and stable isotope probing tools are being developed for linking fluctuations in microbial diversity to ecosystem function.展开更多
AIM： To systematically examine the extent of correlation of risk factors, such as age, consumed dietary habit and familial predisposition with somatic Tp53 molecular lesion causal to elevate carcinogenesis severity o...AIM： To systematically examine the extent of correlation of risk factors, such as age, consumed dietary habit and familial predisposition with somatic Tp53 molecular lesion causal to elevate carcinogenesis severity of esophageal squamous cell carcinoma （ESCC） among the Kashmiri population of Northern India. METHODS： All cases （n = 51） and controls （n = 150） were permanent residents of the Kashmir valley. Genetic alterations were determined in exons 5-8 of Tp53 tumor suppressor gene among 45 ESCC cases histologically confirmed by PCR-SSCP analysis. Data for individual cancer cases （n = 45） and inpatient controls （n = 150） with non-cancer disease included information on family history of cancer, thirty prevailing common dietary risk factors along with patient＇s age group. Correlation of genetic lesion in p53 exons to animistic data from these parameters was generated by Chi-square test to all 45 histologically confirmed ESCC cases along with healthy controls.RESULTS： Thirty-five of 45 （77.8%） histologically characterized tumor samples had analogous somatic mutation as opposed to 1 of 45 normal sample obtained from adjacent region from the same patient showed gerrnline mutation. The SSCP analysis demonstrated that most common p53 gene alterations were found in exon 6 （77.7%）, that did not correlate with the age of the individual and clinicopathological parameters but showed significant concordance （P 〈 0.05） with familial history of cancer （CD = 58）, suggesting germline predisposition at an unknown locus, and dietary habit of consuming locally grown Brassica vegetable ＂Hakh＂ （CD = 19.5）, red chillies （CD = 20.2）, hot salty soda tea （CD = 2.37） and local baked bread （CD = 1.1）. CONCLUSION： Our study suggests that somatic chromosomal mutations, especially in exon 6 of Tp53 gene, among esophageal cancer patients of an ethnically homogenous population of Kashmir valley are closely related to continued exposure to various common dietary risk factors, especially hot salty tea, meat, baked bread and ＂Hakh＂, that are rich in nitrosoamines and familial cancer history.展开更多
Suspended core fiber tapers with different cross sections （with diameters from 70μm to 120 μm） are produced by filament heating. Before obtaining the taper, the spectral behavior of the suspended core fiber is a m...Suspended core fiber tapers with different cross sections （with diameters from 70μm to 120 μm） are produced by filament heating. Before obtaining the taper, the spectral behavior of the suspended core fiber is a multimode interference structure. When the taper is made, an intermodal interference between a few modes is observed. This effect is clearly visible for low taper core dimensions. Since the core and cladding do not collapse, two taper regions exist, one in the core and the other in the cladding. The cladding taper does not affect the light transmission, only the core is reduced to a microtaper. The spectral response of the microtaper based-suspended core fiber is similar to a beat of two interferometers. The strain is applied to the microtaper, and with the reduction in the transverse area, an increase in sensitivity is observed. When the taper is immersed in a liquid with a different index of refraction or subjected to temperature variations, no spectral change Occurs.展开更多
文摘Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues.Because of their prominent role in the global carbon balance and their possible role in carbon sequestration, soil microbes are very important organisms in relation to global climate changes. This review focuses mainly on the responses of soil microbes to climate changes and subsequent effects on soil carbon dynamics. An overview table regarding extracellular enzyme activities(EAA) with all relevant literature data summarizes the effects of different ecosystems under various experimental treatments on EAA. Increasing temperature, altered soil moisture regimes, and elevated carbon dioxide significantly affect directly or indirectly soil microbial activities.High temperature regimes can increase the microbial activities which can provide positive feedback to climate change, whereas lower moisture condition in pedosystem can negate the increase, although the interactive effects still remain unanswered. Shifts in soil microbial community in response to climate change have been determined by gene probing, phospholipid fatty acid analysis(PLFA),terminal restriction length polymorphism(TRFLP), and denaturing gradient gel electrophoresis(DGGE), but in a recent investigations,omic technological interventions have enabled determination of the shift in soil microbe community at a taxa level, which can provide very important inputs for modeling C sequestration process. The intricacy and diversity of the soil microbial population and how it responds to climate change are big challenges, but new molecular and stable isotope probing tools are being developed for linking fluctuations in microbial diversity to ecosystem function.
基金Supported by funding (100%) from the Department of Science and Technology, New Delhi through the Fast Track Young Scientist Project Award to Dr. Imtiyaz Murtaza, No. SR/FTP/LS-A-91/2001
文摘AIM： To systematically examine the extent of correlation of risk factors, such as age, consumed dietary habit and familial predisposition with somatic Tp53 molecular lesion causal to elevate carcinogenesis severity of esophageal squamous cell carcinoma （ESCC） among the Kashmiri population of Northern India. METHODS： All cases （n = 51） and controls （n = 150） were permanent residents of the Kashmir valley. Genetic alterations were determined in exons 5-8 of Tp53 tumor suppressor gene among 45 ESCC cases histologically confirmed by PCR-SSCP analysis. Data for individual cancer cases （n = 45） and inpatient controls （n = 150） with non-cancer disease included information on family history of cancer, thirty prevailing common dietary risk factors along with patient＇s age group. Correlation of genetic lesion in p53 exons to animistic data from these parameters was generated by Chi-square test to all 45 histologically confirmed ESCC cases along with healthy controls.RESULTS： Thirty-five of 45 （77.8%） histologically characterized tumor samples had analogous somatic mutation as opposed to 1 of 45 normal sample obtained from adjacent region from the same patient showed gerrnline mutation. The SSCP analysis demonstrated that most common p53 gene alterations were found in exon 6 （77.7%）, that did not correlate with the age of the individual and clinicopathological parameters but showed significant concordance （P 〈 0.05） with familial history of cancer （CD = 58）, suggesting germline predisposition at an unknown locus, and dietary habit of consuming locally grown Brassica vegetable ＂Hakh＂ （CD = 19.5）, red chillies （CD = 20.2）, hot salty soda tea （CD = 2.37） and local baked bread （CD = 1.1）. CONCLUSION： Our study suggests that somatic chromosomal mutations, especially in exon 6 of Tp53 gene, among esophageal cancer patients of an ethnically homogenous population of Kashmir valley are closely related to continued exposure to various common dietary risk factors, especially hot salty tea, meat, baked bread and ＂Hakh＂, that are rich in nitrosoamines and familial cancer history.
文摘Suspended core fiber tapers with different cross sections （with diameters from 70μm to 120 μm） are produced by filament heating. Before obtaining the taper, the spectral behavior of the suspended core fiber is a multimode interference structure. When the taper is made, an intermodal interference between a few modes is observed. This effect is clearly visible for low taper core dimensions. Since the core and cladding do not collapse, two taper regions exist, one in the core and the other in the cladding. The cladding taper does not affect the light transmission, only the core is reduced to a microtaper. The spectral response of the microtaper based-suspended core fiber is similar to a beat of two interferometers. The strain is applied to the microtaper, and with the reduction in the transverse area, an increase in sensitivity is observed. When the taper is immersed in a liquid with a different index of refraction or subjected to temperature variations, no spectral change Occurs.
