27 research outputs found
A novel mutualism between an ant-plant and its resident pollinator
Pollination systems in which the host plant provides breeding sites for pollinators, invariably within flowers, are usually highly specialized mutualisms. We found that the pollinating bee Braunsapis puangensis breeds within the caulinary domatia of the semi-myrmecophyte Humboldtia brunonis (Fabaceae), an unusual ant-plant that is polymorphic for the presence of domatia and harbours a diverse invertebrate fauna including protective and non-protective ants in its domatia. B. puangensis is the most common flower visitor that carries the highest proportion of H. brunonis pollen. This myrmecophyte is pollen limited and cross-pollinated by bees in the daytime. Hence, the symbiotic pollinator could provide a benefit to trees bearing domatia by alleviating this limitation. We therefore report for the first time an unspecialised mutualism in which a pollinator is housed in a plant structure other than flowers. Here, the cost to the plant is lower than for conventional brood-site pollination mutualisms where the pollinator develops at the expense of plant reproductive structures. Myrmecophytes housing resident pollinators are unusual, as ants are known to be enemies of pollinators, and housing them together may decrease the benefits that these residents could individually provide to the host plant
Evaluation of effect of aqueous extract of leaves of Calotropis procera in pentylenetetrazole induced seizures in rats
Background: The study was carried out to evaluate the effect of aqueous extract of leaves of Calotropis procera in wistar rats.Methods: An aqueous extract of leaves of Calotropis procera was prepared. The effect of acute and chronic administration of the extract was tested in pentylenetetrazole (PTZ) induced seizures in wistar rats. Four groups, each containing 6 rats, were used to evaluate acute and chronic effects of the extract. The four groups were treated with distilled water 10 mL/kg (control group), Valproic acid 200 mg/kg (standard), aqueous extract of C. procera 250 mg/kg and 500 mg/kg respectively. In acute study, PTZ (60 mg/kg, intraperitoneally) was given 1 h after drugs were administered. In chronic study, all drugs were given for 6 weeks following which PTZ was given 1 h after last dose of each drug. The time taken for the onset of myoclonic jerk, seizures and duration of seizures was recorded. GABA levels were estimated in the brain homogenate. Data was analysed by one way analysis of variance followed by Tukey’s test.Results: Acute and chronic administration of the extract significantly increased the time to onset of first clonus and seizures and decreased the total duration of seizures. There was no significant change in GABA levels.Conclusions: Both acute and chronic administration of aqueous extract of leaves of Calotropis procera in Wistar rats inhibited pentylenetetrazole induced seizures in rats
A study of effect of acute and chronic administration of aqueous extract of Calotropis procera leaves on maximal electroshock induced seizures in rats
Background: The effect of acute and chronic administration of aqueous extract of leaves of Calotropis procera on maximal electroshock (MES) induced seizures in rats was evaluated.Methods: Four groups of wistar rats were treated with distilled water 10 mL/kg (oral), phenytoin 25 mg/kg (intraperitoneal), 250mg/kg (oral) and 500mg/kg (oral) of aqueous extract of leaves of C procera, respectively in both acute and chronic studies. For producing maximal electroshock seizures, an electroconvulsiometer was used to deliver an electric stimulus of 150mA for 0.2 sec. The duration of hind limb extension (HLE) and seizures were noted in seconds (sec). In the acute study, the shock was given 1 h after administration of drugs. For the chronic study, all drugs were administered for 6 weeks. One hour after the last dose of drugs, the shock was administered. Data was analyzed by one way ANOVA followed by Tukey’s post hoc test.Results: There was a significant decrease in the duration of hind limb extension, and convulsions as compared to control following acute (p<0.01 vs control) and chronic (p<0.05 vs control) administration of aqueous extract of leaves of Calotropis procera in rats.Conclusions: The study demonstrated that aqueous extract of C procera leaves resulted in significant protection against maximal electroshock induced seizures in rats
Indian Energy Policy and Strategy: Pre- and Post-Copenhagen 2009
Published by Palgrave Macmillan India is an extraordinarily diverse democratic country with one of the fastest growing economies in the world. It is the world’s sixth largest consumer of energy. Interest in its energy policies and strategies is escalating due to their huge impact on geopolitical relations, global energy prices and climate change. Its current per capita energy consumption and GHG emission values are low; however, these are bound to increase if it continues on the path of development that the West has followed. If India is to ‘leapfrog’ the already well-trodden path to one that ensures sustainable development, it is imperative for the country to redefine its development paradigm in order to ensure inclusive growth. Unsustainable subsidies, poor reform implementation, distorted energy prices and inadequate investment in renewables are some of the major constraints that the Indian government needs to re-examine so as to increase energy security and provide a framework for transition to a low-carbon economy. In addition to innovative energy policies such as the National Solar Mission, the National Mission on Enhanced Energy Efficiency and the National Mission on Sustainable Habitat, India needs to adopt a framework for decoupled growth, which we consider as an increase in the quality of life for its citizens without an increase in environmental damage. Since 2008 India has demonstrated that it is serious about changing its growth pattern and moving towards clean energy alternatives. However, this vision will not be fully realised unless the global North provides technical and financial assistance to collectively mitigate the adverse impact of global warming and subsequent climate change
Indian Energy Policy and Strategy: Pre- and Post-Copenhagen 2009
Published by Palgrave Macmillan India is an extraordinarily diverse democratic country with one of the fastest growing economies in the world. It is the world’s sixth largest consumer of energy. Interest in its energy policies and strategies is escalating due to their huge impact on geopolitical relations, global energy prices and climate change. Its current per capita energy consumption and GHG emission values are low; however, these are bound to increase if it continues on the path of development that the West has followed. If India is to ‘leapfrog’ the already well-trodden path to one that ensures sustainable development, it is imperative for the country to redefine its development paradigm in order to ensure inclusive growth. Unsustainable subsidies, poor reform implementation, distorted energy prices and inadequate investment in renewables are some of the major constraints that the Indian government needs to re-examine so as to increase energy security and provide a framework for transition to a low-carbon economy. In addition to innovative energy policies such as the National Solar Mission, the National Mission on Enhanced Energy Efficiency and the National Mission on Sustainable Habitat, India needs to adopt a framework for decoupled growth, which we consider as an increase in the quality of life for its citizens without an increase in environmental damage. Since 2008 India has demonstrated that it is serious about changing its growth pattern and moving towards clean energy alternatives. However, this vision will not be fully realised unless the global North provides technical and financial assistance to collectively mitigate the adverse impact of global warming and subsequent climate change
Potential changes in biomass flows due to India's biodiesel policy: a comparative material flow analysis of the Jatropha Curcas and Prosopis Juliflora economies in Tamil Nadu, India
India's current biodiesel policy mandates the use of non-edible oilseed feedstocks grown exclusively on 'wastelands', the country's term for degraded and marginal lands. In recent years, the Government of India has heavily supported the use of Jatropha curcas as a biodiesel feedstock because of its alleged ability to thrive in marginal landscapes. However, India's wastelands are often rich in local biomass resources that support a host of livelihood and industrial activities. This poster will present a comparative material flow analysis of the biofuel and biomass economies in Virudhunagar District, Tamil Nadu. The South Indian state of Tamil Nadu has been one of the leading promoters of Jatropha biodiesel production and the areas targeted for Jatropha cultivation are densely covered with a local biomass resource, Prosopis juliflora. At present, Prosopis is used as a fuelwood by local villagers and as a feedstock for brick, charcoal, cement and electricity production. Our analysis will evaluate the resource flows of these two energy economies and assess the environmental tradeoffs of replacing Prosopis with Jatropha
A novel mutualism between an ant-plant and its resident pollinator
Pollination systems in which the host plant provides breeding sites for pollinators, invariably within flowers, are usually highly specialized mutualisms. We found that the pollinating bee Braunsapis puangensis breeds within the caulinary domatia of the semi-myrmecophyte Humboldtia brunonis (Fabaceae), an unusual antplant that is polymorphic for the presence of domatia and harbours a diverse invertebrate fauna including protective and non-protective ants in its domatia. B. puangensis is the most common flower visitor that carries the highest proportion of H. brunonis pollen. This myrmecophyte is pollen limited and cross-pollinated by bees in the daytime. Hence, the symbiotic pollinator could provide a benefit to trees bearing domatia by alleviating this limitation. We therefore report for the first time an unspecialised mutualism in which a pollinator is housed in a plant structure other than flowers. Here, the cost to the plant is lower than for conventional brood-site pollination mutualisms where the pollinator develops at the expense of plant reproductive structures. Myrmecophytes housing resident pollinators are unusual, as ants are known to be enemies of pollinators, and housing them together may decrease the benefits that these residents could individually provide to the host plant
Politique et stratégie énergétiques de l’Inde avant et après Copenhague 2009
L’Inde est un pays démocratique d’une extraordinaire diversité. Sa croissance économique est l’une des plus rapides au monde. C’est le sixième plus grand consommateur mondial d’énergie. Ses politiques et ses stratégies énergétiques suscitent un intérêt de plus en plus important en raison de leur impact considérable sur les relations géopolitiques, sur les prix mondiaux de l’énergie et sur les changements climatiques. Actuellement, sa consommation d’énergie per capita et ses valeurs d’émissions de gaz à effet de serre sont faibles. Cependant, elles sont vouées à augmenter si le pays emprunte la même trajectoire de développement que l’Occident. Pour que l’Inde saute par-dessus ces sentiers déjà souvent battus pour en atteindre un qui garantisse un développement durable, le pays doit impérativement redéfinir son paradigme de développement de sorte à assurer une croissance inclusive. Des subventions inviables, une mise en œuvre des réformes laissant à désirer, des prix énergétiques faussés et des investissements inadaptés dans des énergies renouvelables sont quelques-unes des principales entraves que le gouvernement indien doit réexaminer afin d’améliorer la sécurité énergétique et de fournir un cadre de transition vers une économie à faible intensité de carbone. Outre des politiques énergétiques innovatrices telles que la Mission solaire nationale (National Solar Mission), la Mission nationale pour l’amélioration de l’efficacité énergétique (National Mission on Enhanced Energy Efficiency) et la Mission nationale pour l’habitat durable (National Mission on Sustainable Habitat), l’Inde a besoin d’adopter un cadre de croissance découplée, que nous considérons comme une amélioration de la qualité de vie des citoyens sans pour autant intensifier les dommages à l’environnement. Depuis 2008, l’Inde démontre qu’elle prend au sérieux le changement de son modèle de croissance et le passage à des énergies propres. Néanmoins, ces perspectives ne se réaliseront pas pleinement si l’hémisphère Nord n’apporte pas une aide technique et financière pour atténuer collectivement les effets nuisibles du réchauffement de la planète et des changements climatiques qu’il provoque
Why Socio-metabolic Studies are Central to Ecological Economics
Global material extraction has tripled since the 1970s, with more than 100 billion tonnes of materials entering the world economy each year. Only 8.6% of this amount is recycled, while 61% ends up as waste and emissions, the leading cause of global warming and large-scale pollution of land, rivers, and oceans. This theme paper introduces socio-metabolic research (SMR) and demonstrates its relevance to ecological economics scholarship in India. SMR is a research framework for studying the biophysical stocks and flows of materials and energy associated with societal production and consumption. As one of the core approaches in industrial ecology and ecological economics, SMR is widely conducted in Europe, the United States, Japan, Australia, and China. In India, it is still in its infancy. In this paper, we review pioneering efforts in SMR in India and make a case for advancing the field in the subcontinent