2,578 research outputs found

    Conservation Pakage for Modal Ecorace

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    Conserving biodiversity is about genetic variety, species, habitats and ecosystems. All are important, but it is often most appropriate, practical and effective to focus on species. With modern conservation awareness, there is a welcome and popular commitment to maintaining the diversity of species in India. Nevertheless, over the last 50 years, we have witnessed the severe decline of many once widespread and familiar species, such as tropical Tasar silkworm Antherea mylitta D. Conservation is not just about avoiding extinctions, but about restoring or recovering species populations to secure levels and preventing other species from reaching such a perilous situation in the first place. Species, by their very nature, have specific ecological requirements. They may appear to share the same habitat with many others but each has a different, specific niche. It is what sets them apart, and makes them what they are. Habitat loss has historically been a factor in species decline. However, the way existing habitats are managed is also important

    Variability In The Ecoraces Of Tropical Tasar Sillkworm Antheraea Mylitta Drury

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    Tropical tasar silkworm, Antheraea mylitta Drury is exploited in countries for commercial silk production and improved varieties of these silkworms can be evolved by employing various breeding techniques. As the insect has established itself in various forms of ecological populations (Commonly called as ecoraces) in different geographical niches of the country depending on food plants and micro-environmental conditions available to them, the species exists in the form of nearly 44 ecoraces (Singh and Srivastava,1997, Srivastava,2002 and Srivastava et at. 2007) distributed over different states. However, due to free interbreeding in nature for centuries, the fauna is highly heterogeneous.

Tasar culture is a forest based industry being practiced as tradition, since time immemorial by the tribes of Central India, extending from West Bengal in the East to Karnataka in South. The species A. mylitta D. is polyphagous in nature. The present study comprises the ecoraces of tropical tasar silkworm of A. mylitta D. These ecoraces are mainly restricted in the tropical moist deciduous forest area where the average rainfall varies between 1200-2000 mm and the deciduous zone of the dry tropical forest area where the average rainfall has been observed to be about 1000 mm. The Primary food plants of the insects are Terminalia tomentosa, Terminalia arjuna and Shorea robusta and secondary food plants are Terminalia chebula, T. bellerica, T. peniculata, Zizyphus jujuba etc. The phenotypic and genotypic variability is very much prominent. The present review paper comprises the extent and degree of natural variation in tropical tasar silkworm A. mylitta D

    Ostrogradsky instability and Born-Infeld modified cosmology in Palatini formalism

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    The Ostrogradsky instability of higher derivative Lagrangians is derived from first principles using Control theory and Lyapunov Stability Analysis. This result is then used to argue that Born-Infeld Lagrangians are viable modifications of the Einstein-Hilbert action provided the action is varied in accordance with the Palatini formalism, in contrast to the metric formalism. Finally, the Born-Infeld version of the FRW equations are derived and the cosmological dynamics is studied for matter dominated closed and open universes, and the results are compared with the usual cosmology
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