Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different co...Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different concentrations(20,40,60,80 and 100 ppm).Methods:M.oleifera was collected from the area of around Bharathiar University,Coimbatore.The dried plant materials were powdered by an electrical blender.From each sample,100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus.The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material(residue) from Arcang amara and Ocimum basilicum,respectively.One gram of the each plant residue was dissolved separately in 100 mL of acetone(stock solution) from which different concentrations, i.e.,20,40,60,80 and 100 ppm were prepared.Results:Larvicidal activity of M.oleifera exhibited in the first to fourth instar larvae of the A.stephensi,and the LC_(50) and LC_(90) values were 57.79 ppm and 125.93 ppm for the first instar,63.90 ppm and 133.07 ppm for the second inslar,72.45 ppm and 139.82 ppm for the third instar,78.93 ppm and 143.20 ppm for the fourth instar,respectively. During the pupal stage the methanolic extract of M.oleifera showed that the LC_(50),and LC_(90) values were 67.77 ppm and 141.00 ppm,respectively.Conclusions:The present study indicates that the phytochemicals derived from M.oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.展开更多
Foxtail millet (Setaria italica L.) is a drought-tolerant millet crop of arid and semi-arid regions. Aldo-keto reductases (AKRs) are significant part of plant defence mechanism, having an ability to confer multiple st...Foxtail millet (Setaria italica L.) is a drought-tolerant millet crop of arid and semi-arid regions. Aldo-keto reductases (AKRs) are significant part of plant defence mechanism, having an ability to confer multiple stress tolerance. In this study, AKR1 gene expression was studied in roots and leaves of foxtail millet subjected to different regimes of PEG- and NaCl-stress for seven days. The quantitative Real-time PCR expression analysis in both root and leaves showed upregulation of AKR1 gene during PEG and salt stress. A close correlation exits between expression of AKR1 gene and the rate of lipid peroxidation along with the retardation of growth. Tissue-specific differences were found in the AKR1 gene expression to the stress intensities studied. The reduction in root and shoot growth under both stress conditions were dependent on stress severity. The level of lipid peroxidation as indicated by MDA formation was significantly increased in roots and leaves along with increased stress levels. Finally, these findings support the early responsive nature of AKR1 gene and seem to be associated at least in part with its ability to contribute in antioxidant defence related pathways which could provide a better protection against oxidative stress under stress conditions.展开更多
Safflower is an important, traditional, multipurpose oil crop. This was to investigate the effect of different salinity levels on morphological, physiological, biochemical and antioxidant response of two safflower cul...Safflower is an important, traditional, multipurpose oil crop. This was to investigate the effect of different salinity levels on morphological, physiological, biochemical and antioxidant response of two safflower cultivars (Carthamus tinctorius L. cultivar TSF1 and cultivar SM) differing in salt tolerance. Salinity stress (0.0%, 1.0%, 1.5% and 2.0% of NaCl) was induced to safflower plants after 19 days of vegetative growth. After 12 days of stress impositions, plants were harvested and analysed for various parameters. The results revealed that cultivar TSF1 showed maximum growth, dry weight, cell membrane stability and more water content in both root and leaf tissues at higher salinity levels than cultivar SM. Salt stress resulted an accumulation of more soluble sugars, amino acids, proline and glycine betaine at high salinity level confers the tolerance potential of cultivar TSF1 over cultivar SM. Salt stress induces more increase in the enzyme activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and catalase in tolerant cultivar than sensitive one. The results indicate that each cultivar adopt specific strategy at distinct salinity level for resistance against salinity. The possible conclusion is that improved tolerance in cultivar TSF1 to salinity may be accomplished by better management of growth, physiological attributes and antioxidative defence mechanisms.展开更多
Drought and salt stress are two major environmental constraints that limit the productivity of agriculture crops worldwide. WRKY transcription factors are the plant-specific transcription factors that regulate several...Drought and salt stress are two major environmental constraints that limit the productivity of agriculture crops worldwide. WRKY transcription factors are the plant-specific transcription factors that regulate several developmental events and stress responses in plants. The WRKY domain is defined by a 60-amino acid conserved sequence named WRKYGQK at N-terminal and a Zinc Finger-like motif at the C-terminal. WRKY genes are known to respond several stresses which may act as negative or positive regulators. The function of most of the WRKY transcription factors from non-model plants remains poorly understood. This investigation shows the expression levels of eight WRKY transcription factor genes from horsegram plant under drought and salt stress conditions. The increase in mRNA transcript levels of WRKY transcription factor genes was found to be high in drought stressed plants compared to salt-stressed plants. The levels of MDA which indicates the lipid peroxidation were less in drought stress. More ROS is produced in salt stress conditions compared to drought. The results show that the expression of WRKY transcription factors in drought stress conditions is reducing the adverse effect of stress on plants. These results also suggest that, during abiotic stress conditions such as drought and salt stress, WRKY transcription factors are regulated at the transcription level.展开更多
With advancements in computing powers and the overall quality of images captured on everyday cameras,a much wider range of possibilities has opened in various scenarios.This fact has several implications for deaf and ...With advancements in computing powers and the overall quality of images captured on everyday cameras,a much wider range of possibilities has opened in various scenarios.This fact has several implications for deaf and dumb people as they have a chance to communicate with a greater number of people much easier.More than ever before,there is a plethora of info about sign language usage in the real world.Sign languages,and by extension the datasets available,are of two forms,isolated sign language and continuous sign language.The main difference between the two types is that in isolated sign language,the hand signs cover individual letters of the alphabet.In continuous sign language,entire words’hand signs are used.This paper will explore a novel deep learning architecture that will use recently published large pre-trained image models to quickly and accurately recognize the alphabets in the American Sign Language(ASL).The study will focus on isolated sign language to demonstrate that it is possible to achieve a high level of classification accuracy on the data,thereby showing that interpreters can be implemented in the real world.The newly proposed Mobile-NetV2 architecture serves as the backbone of this study.It is designed to run on end devices like mobile phones and infer signals(what does it infer)from images in a relatively short amount of time.With the proposed architecture in this paper,the classification accuracy of 98.77%in the Indian Sign Language(ISL)and American Sign Language(ASL)is achieved,outperforming the existing state-of-the-art systems.展开更多
In this paper, a model is proposed to study the impact of awareness on the dynamics of dengue. It is assumed that due to awareness of the disease some susceptible take necessary precautionary measures to protect thems...In this paper, a model is proposed to study the impact of awareness on the dynamics of dengue. It is assumed that due to awareness of the disease some susceptible take necessary precautionary measures to protect themselves from mosquito bite. A threshold is obtained for the stability of the disease-free equilibrium state. The awareness is found to affect the threshold. For the sufficiently large awareness rate, the endemic state does not exist and disease-free state remains globally stable. It is concluded that the increase in the awareness rate decreases the densities of infectious populations of human as well as mosquitoes.展开更多
Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at ...Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at different concentrations(0.01,0.02,0.04,0.06 and 0.08 ppm.), and against first to fourth instar larvae and pupae.Results:The larval mortality ranged from 36.1±1.7 in(0.01 ppm) to 79.3±1.8(0.08 ppm) the first instar larva.The LC<sub>50</sub> and LC<sub>90</sub> values of first, second,third and fourth instar larva were 0.001,0.031,0.034,0.036 and 0.0113,0.102,0.111,0.113, respectively.The pupal mortality ranged from 33.0±2.0(0.01 ppm) to 80.0±0.9(0.08 ppm).The LC<sub>50</sub> and LC<sub>90</sub> values were 0.028 and 0.1020,respectively.The reduction percentage of Anopheles larvae was 82.7%,91.4%and 96.0%after 24,48,72 hours,respectively,while more than 80% reduction was observed after 3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial.It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.展开更多
Lead (Pb) is an important environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Pb phytotoxicity, a pot culture experiment was carried out using two groundnut cultiva...Lead (Pb) is an important environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Pb phytotoxicity, a pot culture experiment was carried out using two groundnut cultivars (Arachis hypogaea L. cultivar K6 and cultivar K9) on plant growth, ROS levels, lipid peroxidation, and antioxidant metabolism using biochemical, histochemical methods. Plants were grown in pots for 14 days, in the botanic garden, and subjected to Pb-stress (0, 100, 200, 400 and 800 ppm) by adding Pb (NO3)2 solution and further allowed to grow for 10 days. The results showed that cultivar K6 registered lower Pb accumulation than cultivar K9, however, localization of Pb was greater in roots than leaves in both groundnut cultivars. The Pb-stress results in an increase in free radicals (O2?- and H2O2) generation in both groundnut cultivars, but more significantly in cultivar K9 than K6. Pb-stress also caused significant changes in the rate of peroxidation as shown in the levels of malondialdehyde (MDA) content in roots and leaves of both groundnut cultivars. Free proline, ascorbic acid (AsA) and non-protein thiol (NP-SH) contents were increased in cultivar K6 due to Pb-stress, but less in cultivar K9. Pb treated plants showed increased levels of antioxidant enzymes such as superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) glutathione reductase (GR) and glutathione S-transferase (GST). Isozyme band intensities of SOD, GPX and APX were more consistent with the respective changes in antioxidative enzyme activities. These results indicate that cultivar K6 possesses greater tolerance potential for Pb toxicity than cultivar K9.展开更多
文摘Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different concentrations(20,40,60,80 and 100 ppm).Methods:M.oleifera was collected from the area of around Bharathiar University,Coimbatore.The dried plant materials were powdered by an electrical blender.From each sample,100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus.The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material(residue) from Arcang amara and Ocimum basilicum,respectively.One gram of the each plant residue was dissolved separately in 100 mL of acetone(stock solution) from which different concentrations, i.e.,20,40,60,80 and 100 ppm were prepared.Results:Larvicidal activity of M.oleifera exhibited in the first to fourth instar larvae of the A.stephensi,and the LC_(50) and LC_(90) values were 57.79 ppm and 125.93 ppm for the first instar,63.90 ppm and 133.07 ppm for the second inslar,72.45 ppm and 139.82 ppm for the third instar,78.93 ppm and 143.20 ppm for the fourth instar,respectively. During the pupal stage the methanolic extract of M.oleifera showed that the LC_(50),and LC_(90) values were 67.77 ppm and 141.00 ppm,respectively.Conclusions:The present study indicates that the phytochemicals derived from M.oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.
文摘Foxtail millet (Setaria italica L.) is a drought-tolerant millet crop of arid and semi-arid regions. Aldo-keto reductases (AKRs) are significant part of plant defence mechanism, having an ability to confer multiple stress tolerance. In this study, AKR1 gene expression was studied in roots and leaves of foxtail millet subjected to different regimes of PEG- and NaCl-stress for seven days. The quantitative Real-time PCR expression analysis in both root and leaves showed upregulation of AKR1 gene during PEG and salt stress. A close correlation exits between expression of AKR1 gene and the rate of lipid peroxidation along with the retardation of growth. Tissue-specific differences were found in the AKR1 gene expression to the stress intensities studied. The reduction in root and shoot growth under both stress conditions were dependent on stress severity. The level of lipid peroxidation as indicated by MDA formation was significantly increased in roots and leaves along with increased stress levels. Finally, these findings support the early responsive nature of AKR1 gene and seem to be associated at least in part with its ability to contribute in antioxidant defence related pathways which could provide a better protection against oxidative stress under stress conditions.
文摘Safflower is an important, traditional, multipurpose oil crop. This was to investigate the effect of different salinity levels on morphological, physiological, biochemical and antioxidant response of two safflower cultivars (Carthamus tinctorius L. cultivar TSF1 and cultivar SM) differing in salt tolerance. Salinity stress (0.0%, 1.0%, 1.5% and 2.0% of NaCl) was induced to safflower plants after 19 days of vegetative growth. After 12 days of stress impositions, plants were harvested and analysed for various parameters. The results revealed that cultivar TSF1 showed maximum growth, dry weight, cell membrane stability and more water content in both root and leaf tissues at higher salinity levels than cultivar SM. Salt stress resulted an accumulation of more soluble sugars, amino acids, proline and glycine betaine at high salinity level confers the tolerance potential of cultivar TSF1 over cultivar SM. Salt stress induces more increase in the enzyme activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and catalase in tolerant cultivar than sensitive one. The results indicate that each cultivar adopt specific strategy at distinct salinity level for resistance against salinity. The possible conclusion is that improved tolerance in cultivar TSF1 to salinity may be accomplished by better management of growth, physiological attributes and antioxidative defence mechanisms.
文摘Drought and salt stress are two major environmental constraints that limit the productivity of agriculture crops worldwide. WRKY transcription factors are the plant-specific transcription factors that regulate several developmental events and stress responses in plants. The WRKY domain is defined by a 60-amino acid conserved sequence named WRKYGQK at N-terminal and a Zinc Finger-like motif at the C-terminal. WRKY genes are known to respond several stresses which may act as negative or positive regulators. The function of most of the WRKY transcription factors from non-model plants remains poorly understood. This investigation shows the expression levels of eight WRKY transcription factor genes from horsegram plant under drought and salt stress conditions. The increase in mRNA transcript levels of WRKY transcription factor genes was found to be high in drought stressed plants compared to salt-stressed plants. The levels of MDA which indicates the lipid peroxidation were less in drought stress. More ROS is produced in salt stress conditions compared to drought. The results show that the expression of WRKY transcription factors in drought stress conditions is reducing the adverse effect of stress on plants. These results also suggest that, during abiotic stress conditions such as drought and salt stress, WRKY transcription factors are regulated at the transcription level.
文摘With advancements in computing powers and the overall quality of images captured on everyday cameras,a much wider range of possibilities has opened in various scenarios.This fact has several implications for deaf and dumb people as they have a chance to communicate with a greater number of people much easier.More than ever before,there is a plethora of info about sign language usage in the real world.Sign languages,and by extension the datasets available,are of two forms,isolated sign language and continuous sign language.The main difference between the two types is that in isolated sign language,the hand signs cover individual letters of the alphabet.In continuous sign language,entire words’hand signs are used.This paper will explore a novel deep learning architecture that will use recently published large pre-trained image models to quickly and accurately recognize the alphabets in the American Sign Language(ASL).The study will focus on isolated sign language to demonstrate that it is possible to achieve a high level of classification accuracy on the data,thereby showing that interpreters can be implemented in the real world.The newly proposed Mobile-NetV2 architecture serves as the backbone of this study.It is designed to run on end devices like mobile phones and infer signals(what does it infer)from images in a relatively short amount of time.With the proposed architecture in this paper,the classification accuracy of 98.77%in the Indian Sign Language(ISL)and American Sign Language(ASL)is achieved,outperforming the existing state-of-the-art systems.
文摘In this paper, a model is proposed to study the impact of awareness on the dynamics of dengue. It is assumed that due to awareness of the disease some susceptible take necessary precautionary measures to protect themselves from mosquito bite. A threshold is obtained for the stability of the disease-free equilibrium state. The awareness is found to affect the threshold. For the sufficiently large awareness rate, the endemic state does not exist and disease-free state remains globally stable. It is concluded that the increase in the awareness rate decreases the densities of infectious populations of human as well as mosquitoes.
文摘Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at different concentrations(0.01,0.02,0.04,0.06 and 0.08 ppm.), and against first to fourth instar larvae and pupae.Results:The larval mortality ranged from 36.1±1.7 in(0.01 ppm) to 79.3±1.8(0.08 ppm) the first instar larva.The LC<sub>50</sub> and LC<sub>90</sub> values of first, second,third and fourth instar larva were 0.001,0.031,0.034,0.036 and 0.0113,0.102,0.111,0.113, respectively.The pupal mortality ranged from 33.0±2.0(0.01 ppm) to 80.0±0.9(0.08 ppm).The LC<sub>50</sub> and LC<sub>90</sub> values were 0.028 and 0.1020,respectively.The reduction percentage of Anopheles larvae was 82.7%,91.4%and 96.0%after 24,48,72 hours,respectively,while more than 80% reduction was observed after 3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial.It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.
文摘Lead (Pb) is an important environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Pb phytotoxicity, a pot culture experiment was carried out using two groundnut cultivars (Arachis hypogaea L. cultivar K6 and cultivar K9) on plant growth, ROS levels, lipid peroxidation, and antioxidant metabolism using biochemical, histochemical methods. Plants were grown in pots for 14 days, in the botanic garden, and subjected to Pb-stress (0, 100, 200, 400 and 800 ppm) by adding Pb (NO3)2 solution and further allowed to grow for 10 days. The results showed that cultivar K6 registered lower Pb accumulation than cultivar K9, however, localization of Pb was greater in roots than leaves in both groundnut cultivars. The Pb-stress results in an increase in free radicals (O2?- and H2O2) generation in both groundnut cultivars, but more significantly in cultivar K9 than K6. Pb-stress also caused significant changes in the rate of peroxidation as shown in the levels of malondialdehyde (MDA) content in roots and leaves of both groundnut cultivars. Free proline, ascorbic acid (AsA) and non-protein thiol (NP-SH) contents were increased in cultivar K6 due to Pb-stress, but less in cultivar K9. Pb treated plants showed increased levels of antioxidant enzymes such as superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) glutathione reductase (GR) and glutathione S-transferase (GST). Isozyme band intensities of SOD, GPX and APX were more consistent with the respective changes in antioxidative enzyme activities. These results indicate that cultivar K6 possesses greater tolerance potential for Pb toxicity than cultivar K9.