This study presents a geochemical investigation of Tikak Parbat and Tipam Sandstone Formations occurring in and around Dilli area, Sivasagar, Assam. Petrographically Tikak Parbat and Tipam sandstones are mainly quartz...This study presents a geochemical investigation of Tikak Parbat and Tipam Sandstone Formations occurring in and around Dilli area, Sivasagar, Assam. Petrographically Tikak Parbat and Tipam sandstones are mainly quartzose arenite to sublitharenite types with their constituents being derived from recycled orogen provenance under sub-humid to humid climatic conditions. Geochemically, sandstones of both the formations range from sublitharenite to wacke. They indicate a recycled orogen source and influence of humid to arid condition. Source rocks of Tikak Parbat sandstones were more weathered than the Tipam sandstones. While Tikak Parbat sandstones show affinity towards passive margin, Tipam sandstones hint at active continental margin setup, where clasts were supplied from uplifted areas. Upliftment of provenance covering areas of Naga Patkai Range in the south east and Eastern Himalayas along the syntaxial bend during mid Miocene affected the sandstones. Tikak Parbat sandstones reflect a stable tectonic setup which later underwent a phase of volatility leading to deposition of the Tipam sandstones. Our study supports a sediment supply from the upper continental crust, largely of granitic composition, however, with a significant variation in their depth of source supply. Trace element analyses indicate depositional setup with low ventilation marked by both oxic and anoxic phases.展开更多
Endophytic fungal isolates(139 no.)were obtained from 143(62 roots,18 fruits and 54 leaves)samples of 15 different varieties of banana collected from 10 sites in Assam,India during 2018-2019.Overall isolation fr...Endophytic fungal isolates(139 no.)were obtained from 143(62 roots,18 fruits and 54 leaves)samples of 15 different varieties of banana collected from 10 sites in Assam,India during 2018-2019.Overall isolation frequency from surface-sterilized tissue ranged from 10%-80%(as per site)and 6%-70%(as per variety of banana).All isolates were segregated into 40 different types on the basis of macromorphological and micro morphological characteristics.Forty different fungal taxa were isolated belonging to 14 genera including Absidia,Arthrinium,Aspergillus,Bipolaris,Cladosporium,Curvularia,Dendrophion,Fusarium,Humicola,Mortierella,Mucor,Penicillium,Paecilomyces,Verticillium and one mycelium sterile.Among them,Cladosporium cladosporioidies and Paecilomyces sp.frequently occurred in most of the sites surveyed whereas Cladospoirum cladosporioides and Aspergillus sp.8,Fusarium graminseram were most frequently isolated from different varieties.However,all sites differed in their fungal diversity.Banana samples from Narigoan and Jorhat have been found with maximum fungal species followed by marigoan samples so as to Banana varieties Amrit Sagar endowed 27 no.of fungi followed by Jehaji and Honda which were associated with a maximum 14 fungal sp.Isolation frequency and relative abundance of Cladosporium cladosporiodes(80%,4.6),Paecilomyces farinosus(80%,4.6)followed by Penicillium ruburm,Aspergillus sp.8&9(70%,4.02)were recorded as maximum comparatively in different sites.However,Aspergillus sp.8,Mortieralla sp.and Pacilomyces farinosus are isolated frequently from different banana varieties(73.33%,4.93).展开更多
We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total o...We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total of 166 species (80 trees, 20 shrubs and 66 herbs) of 136 genera and 63 families were recorded in both study sites. The disturbance index at the two sites, Kumorakata Reserve Forest and Hojai Reserve Forest, were recorded at 11.4% and 3.70% respectively. Reverse J-shaped population curve and exploitation of tree species in higher girth classes were recorded at both study sites. In the girth classes (10-30 cm, 30-60 cm, 60-90 cm and 90-120 cm in size) the percentage of cut stump density was higher than the percentage of individual living trees. The 18% (Kumorakata Reserve Forest) and 7% (Hojai Reserve Forest) spe- cies were recorded as not regenerating. Illegal felling and over-exploitation of forest resources may lead to species-specific changes in the population structure and can alter the future structure and composi- tion of the forests.展开更多
Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from...Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance(AAI) and relative acoustic impedance(RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone(TS) and Barail Arenaceous Sandstone(BAS) are the main reservoirs,delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network(MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively.展开更多
We identified 67 and 21 NTFP-yielding plant and animal species, respectively, in a reserve forest in Cachar district of Assam. We recorded globally threatened species listed by IUCN as Critically Endangered (plant sp...We identified 67 and 21 NTFP-yielding plant and animal species, respectively, in a reserve forest in Cachar district of Assam. We recorded globally threatened species listed by IUCN as Critically Endangered (plant species Dipterocarpus turbinatus), Vulnerable (plant species Aquillaria malaccensis), Endangered (animal species Hoolock hoolock, Indotestudo elongata and Manis pentadactyla), and Vulnerable (animal species Nilssonia hurum and Rusa unicolor). The whole plant or animal and/or their various parts were used as food or medicine, in house construction, magico-religious activities and others. While some NTFPs were harvested throughout the year, others were harvested seasonally. A comprehensive NTFP policy, along with scientific measures for regen- eration, restoration and augmentation of NTFP-yielding plants and animals, would help in addressing the conflicting demands of conservation and livelihood in the forests of this area.展开更多
Background: The national HIV scenario in India has improved impressively during past two decades. Contrastingly, the State-level HIV sentinel surveil-lance and routine programme data from various testing facilities in...Background: The national HIV scenario in India has improved impressively during past two decades. Contrastingly, the State-level HIV sentinel surveil-lance and routine programme data from various testing facilities indicated an increasing HIV prevalence among antenatal clinic attendees and female sex workers (FSWs) in three districts of Assam. Objectives: 1) To explore the reasons behind increasing adult HIV prevalence and 2) To understand the role of FSW and Migrants/long distance truckers as drivers of the HIV epi-demic in these districts. Methodology: Three sources of data were utilized in this concurrent mixed methods study—1) existing programme data for past three years;2) questionnaire-based data for a case-control study, where dur-ing past six months at designated testing facilities HIV(+) married women were “cases” and age-matched HIV(?) women from the same district were “controls”. Spouses of these women were also interviewed separately;and 3) a qualitative study, where focus group discussions were conducted among FSWs, outgoing male migrant labourers and long-distance truckers. Results: The study revealed high levels of unsafe sexual practices among the FSWs. Sometimes in poverty-struck areas, women, not identifying themselves as sex workers, sold sex on a part-time basis to earn extra money for financial sup-port and often remained invisible to the programme. The clients of the sex workers, male migrants and truckers also revealed various risk behaviours for contracting and transmitting HIV infection. Conclusion: Population and context specific programme strategies are required to halt the rising trend of HIV infection in the general population in Assam.展开更多
Extracting geothermal energy from the oil-producing fields is an experimental venture globally.The exploitation and utilization of geothermal energy can partly reduce the larger dependence on conventional non-renewabl...Extracting geothermal energy from the oil-producing fields is an experimental venture globally.The exploitation and utilization of geothermal energy can partly reduce the larger dependence on conventional non-renewable energy sources like oil,gas,coal,and other fossil fuels,and has a bright prospect.The Upper Assam Basin is a mature petroliferous basin of NE India,where there are several hundred low production,high water cut,or abandoned oil and gas wells that can be retrofitted as geothermal wells instead of drilling new ones.This will help bridge the gap of growing energy demand and limited supply in energy-deficient state like Assam.Situated away from the active plate boundaries and in lack of active volcanism,the Upper Assam Basin remains a low-to-medium enthalpy geothermal fluid regime.The deeper reservoir in this regard can,therefore,be the best candidate for the introspection of the potential geothermal energy reservoir reconnaissance.The selection of a deeper horizon considered in the present case has been the stratified reservoirs of the Lakadong-Therria(Lk-Th)Formation,Sylhet Group of the Lower Eocene age occurring at a variable depth of 3400 me 4600 m.The Lk-Th Formation possesses a fair-quality reservoir with lateral continuity and favourable petrophysical properties.In this study,representative gamma-ray(GR)and resistivity(R)logs were examined to work out lithology,and bed boundary demarcation,etc.The total Formation thickness varies from 97 to 157 m;the individual sand body thickness is up to 6 m.Other reservoir parameters,e.g.,porosity(φ=8-33%),water saturation(S_(w)=4.57-95.15%),geothermal gradient(2.71℃/100m to 3.92 C/100 m at 4300 m and 3608 m)respectively,and theoretical estimate of high heat flux in the range 70e100 mW/m^(2)/s,are the necessary yard-stick to measure the subsurface geothermal reserves.Efficient energy extraction will have the potential in facilitating energy utilization for industrial purposes,especially in tea processing units present nearby oilfields and also for power generation by the binary mechanism.展开更多
In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-ba...In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.展开更多
Objective:To assess the best suitable condition for virus inactivation.and to study the immunogenic potential and protective efficacy of a circulating West Nile virus(WNV) strain in Assam.Methods:Bulk preparation of c...Objective:To assess the best suitable condition for virus inactivation.and to study the immunogenic potential and protective efficacy of a circulating West Nile virus(WNV) strain in Assam.Methods:Bulk preparation of circulating WNV:WNIRGC07(GeneBank ID:HQ246154).was undertaken in a bioreaclor using eytodex-1.Virus Inactivation was done in three different conditions:22 ℃.4 ℃ and room temperature.The virus preparations were evaluated for antigenicity by ELISA and toxicity by cell proliferation kit.Virus efficacy was done in-viro on swiss albino mice against standard Indian WNV and Japanese encephalitis virus(JKV)strain.Humoral and cell mediated immune response was evaluated in mice sera by ELISA and neutralization assay.Results:Inactivation at 22 ℃ was found to be more suitable in terms of less toxicity and high antigenicity.The same was selected to study the immune response and efficacy in mice.It induced neutralizing antibody titre of 1:625 and high EgG response.In vivo experiment showed 100% protective efficacy against WNV and 20.8% cross protective efficacy against JEV.Further assessment of cellular immunity through immunized mice revealed augmentation of high levels of pro-inflammatory cytokines and moderate levels of anti—cytokines indicating a mixed balance of Th1 and Th2 response.Conclusions:Findings suggest that formalin inactivated Indian WNV strain has a good immunogenic potential.This is the first study on assessment of immunogenic potential of a lineage 5 strain of WNV.Our study reveals that it would be a promising and effective candidate for vaccine studies which warrants further evaluation.展开更多
文摘This study presents a geochemical investigation of Tikak Parbat and Tipam Sandstone Formations occurring in and around Dilli area, Sivasagar, Assam. Petrographically Tikak Parbat and Tipam sandstones are mainly quartzose arenite to sublitharenite types with their constituents being derived from recycled orogen provenance under sub-humid to humid climatic conditions. Geochemically, sandstones of both the formations range from sublitharenite to wacke. They indicate a recycled orogen source and influence of humid to arid condition. Source rocks of Tikak Parbat sandstones were more weathered than the Tipam sandstones. While Tikak Parbat sandstones show affinity towards passive margin, Tipam sandstones hint at active continental margin setup, where clasts were supplied from uplifted areas. Upliftment of provenance covering areas of Naga Patkai Range in the south east and Eastern Himalayas along the syntaxial bend during mid Miocene affected the sandstones. Tikak Parbat sandstones reflect a stable tectonic setup which later underwent a phase of volatility leading to deposition of the Tipam sandstones. Our study supports a sediment supply from the upper continental crust, largely of granitic composition, however, with a significant variation in their depth of source supply. Trace element analyses indicate depositional setup with low ventilation marked by both oxic and anoxic phases.
基金funded by Department of Biotechnology,Govt.of India,New Delhi under network project under NER-BPMC-DBT-NER/AGRI/33/2016.
文摘Endophytic fungal isolates(139 no.)were obtained from 143(62 roots,18 fruits and 54 leaves)samples of 15 different varieties of banana collected from 10 sites in Assam,India during 2018-2019.Overall isolation frequency from surface-sterilized tissue ranged from 10%-80%(as per site)and 6%-70%(as per variety of banana).All isolates were segregated into 40 different types on the basis of macromorphological and micro morphological characteristics.Forty different fungal taxa were isolated belonging to 14 genera including Absidia,Arthrinium,Aspergillus,Bipolaris,Cladosporium,Curvularia,Dendrophion,Fusarium,Humicola,Mortierella,Mucor,Penicillium,Paecilomyces,Verticillium and one mycelium sterile.Among them,Cladosporium cladosporioidies and Paecilomyces sp.frequently occurred in most of the sites surveyed whereas Cladospoirum cladosporioides and Aspergillus sp.8,Fusarium graminseram were most frequently isolated from different varieties.However,all sites differed in their fungal diversity.Banana samples from Narigoan and Jorhat have been found with maximum fungal species followed by marigoan samples so as to Banana varieties Amrit Sagar endowed 27 no.of fungi followed by Jehaji and Honda which were associated with a maximum 14 fungal sp.Isolation frequency and relative abundance of Cladosporium cladosporiodes(80%,4.6),Paecilomyces farinosus(80%,4.6)followed by Penicillium ruburm,Aspergillus sp.8&9(70%,4.02)were recorded as maximum comparatively in different sites.However,Aspergillus sp.8,Mortieralla sp.and Pacilomyces farinosus are isolated frequently from different banana varieties(73.33%,4.93).
文摘We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total of 166 species (80 trees, 20 shrubs and 66 herbs) of 136 genera and 63 families were recorded in both study sites. The disturbance index at the two sites, Kumorakata Reserve Forest and Hojai Reserve Forest, were recorded at 11.4% and 3.70% respectively. Reverse J-shaped population curve and exploitation of tree species in higher girth classes were recorded at both study sites. In the girth classes (10-30 cm, 30-60 cm, 60-90 cm and 90-120 cm in size) the percentage of cut stump density was higher than the percentage of individual living trees. The 18% (Kumorakata Reserve Forest) and 7% (Hojai Reserve Forest) spe- cies were recorded as not regenerating. Illegal felling and over-exploitation of forest resources may lead to species-specific changes in the population structure and can alter the future structure and composi- tion of the forests.
基金funding the project (MoES/P.O. (Seismo)/1(273)/2015)
文摘Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance(AAI) and relative acoustic impedance(RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone(TS) and Barail Arenaceous Sandstone(BAS) are the main reservoirs,delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network(MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively.
文摘We identified 67 and 21 NTFP-yielding plant and animal species, respectively, in a reserve forest in Cachar district of Assam. We recorded globally threatened species listed by IUCN as Critically Endangered (plant species Dipterocarpus turbinatus), Vulnerable (plant species Aquillaria malaccensis), Endangered (animal species Hoolock hoolock, Indotestudo elongata and Manis pentadactyla), and Vulnerable (animal species Nilssonia hurum and Rusa unicolor). The whole plant or animal and/or their various parts were used as food or medicine, in house construction, magico-religious activities and others. While some NTFPs were harvested throughout the year, others were harvested seasonally. A comprehensive NTFP policy, along with scientific measures for regen- eration, restoration and augmentation of NTFP-yielding plants and animals, would help in addressing the conflicting demands of conservation and livelihood in the forests of this area.
文摘Background: The national HIV scenario in India has improved impressively during past two decades. Contrastingly, the State-level HIV sentinel surveil-lance and routine programme data from various testing facilities indicated an increasing HIV prevalence among antenatal clinic attendees and female sex workers (FSWs) in three districts of Assam. Objectives: 1) To explore the reasons behind increasing adult HIV prevalence and 2) To understand the role of FSW and Migrants/long distance truckers as drivers of the HIV epi-demic in these districts. Methodology: Three sources of data were utilized in this concurrent mixed methods study—1) existing programme data for past three years;2) questionnaire-based data for a case-control study, where dur-ing past six months at designated testing facilities HIV(+) married women were “cases” and age-matched HIV(?) women from the same district were “controls”. Spouses of these women were also interviewed separately;and 3) a qualitative study, where focus group discussions were conducted among FSWs, outgoing male migrant labourers and long-distance truckers. Results: The study revealed high levels of unsafe sexual practices among the FSWs. Sometimes in poverty-struck areas, women, not identifying themselves as sex workers, sold sex on a part-time basis to earn extra money for financial sup-port and often remained invisible to the programme. The clients of the sex workers, male migrants and truckers also revealed various risk behaviours for contracting and transmitting HIV infection. Conclusion: Population and context specific programme strategies are required to halt the rising trend of HIV infection in the general population in Assam.
文摘Extracting geothermal energy from the oil-producing fields is an experimental venture globally.The exploitation and utilization of geothermal energy can partly reduce the larger dependence on conventional non-renewable energy sources like oil,gas,coal,and other fossil fuels,and has a bright prospect.The Upper Assam Basin is a mature petroliferous basin of NE India,where there are several hundred low production,high water cut,or abandoned oil and gas wells that can be retrofitted as geothermal wells instead of drilling new ones.This will help bridge the gap of growing energy demand and limited supply in energy-deficient state like Assam.Situated away from the active plate boundaries and in lack of active volcanism,the Upper Assam Basin remains a low-to-medium enthalpy geothermal fluid regime.The deeper reservoir in this regard can,therefore,be the best candidate for the introspection of the potential geothermal energy reservoir reconnaissance.The selection of a deeper horizon considered in the present case has been the stratified reservoirs of the Lakadong-Therria(Lk-Th)Formation,Sylhet Group of the Lower Eocene age occurring at a variable depth of 3400 me 4600 m.The Lk-Th Formation possesses a fair-quality reservoir with lateral continuity and favourable petrophysical properties.In this study,representative gamma-ray(GR)and resistivity(R)logs were examined to work out lithology,and bed boundary demarcation,etc.The total Formation thickness varies from 97 to 157 m;the individual sand body thickness is up to 6 m.Other reservoir parameters,e.g.,porosity(φ=8-33%),water saturation(S_(w)=4.57-95.15%),geothermal gradient(2.71℃/100m to 3.92 C/100 m at 4300 m and 3608 m)respectively,and theoretical estimate of high heat flux in the range 70e100 mW/m^(2)/s,are the necessary yard-stick to measure the subsurface geothermal reserves.Efficient energy extraction will have the potential in facilitating energy utilization for industrial purposes,especially in tea processing units present nearby oilfields and also for power generation by the binary mechanism.
文摘In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.
文摘Objective:To assess the best suitable condition for virus inactivation.and to study the immunogenic potential and protective efficacy of a circulating West Nile virus(WNV) strain in Assam.Methods:Bulk preparation of circulating WNV:WNIRGC07(GeneBank ID:HQ246154).was undertaken in a bioreaclor using eytodex-1.Virus Inactivation was done in three different conditions:22 ℃.4 ℃ and room temperature.The virus preparations were evaluated for antigenicity by ELISA and toxicity by cell proliferation kit.Virus efficacy was done in-viro on swiss albino mice against standard Indian WNV and Japanese encephalitis virus(JKV)strain.Humoral and cell mediated immune response was evaluated in mice sera by ELISA and neutralization assay.Results:Inactivation at 22 ℃ was found to be more suitable in terms of less toxicity and high antigenicity.The same was selected to study the immune response and efficacy in mice.It induced neutralizing antibody titre of 1:625 and high EgG response.In vivo experiment showed 100% protective efficacy against WNV and 20.8% cross protective efficacy against JEV.Further assessment of cellular immunity through immunized mice revealed augmentation of high levels of pro-inflammatory cytokines and moderate levels of anti—cytokines indicating a mixed balance of Th1 and Th2 response.Conclusions:Findings suggest that formalin inactivated Indian WNV strain has a good immunogenic potential.This is the first study on assessment of immunogenic potential of a lineage 5 strain of WNV.Our study reveals that it would be a promising and effective candidate for vaccine studies which warrants further evaluation.