1,259 research outputs found
Water-mediated variability in the structure of relaxed-state haemoglobin
The crystal structure of high-salt horse methaemoglobin has been determined at environmental relative humidities (r.h.) of 88, 79, 75 and 66%. The molecule is in the R state in the native and the r.h. 88% crystals. At r.h. 79%, the water content of the crystal is reduced and the molecule appears to move towards the R2 state. The crystals undergo a water-mediated transformation involving a doubling of one of the unit-cell parameters and an increase in water content when the environmental humidity is further reduced to r.h. 75%. The water content is now similar to that in the native crystals and the molecules are in the R state. The crystal structure at r.h. 66% is similar, but not identical, to that at r.h. 75%, but the solvent content is substantially reduced and the molecules have a quaternary structure that is in between those corresponding to the R and R2 states. Thus, variation in hydration leads to variation in the quaternary structure. Furthermore, partial dehydration appears to shift the structure from the R state to the R2 state. This observation is in agreement with the earlier conclusion that the changes in protein structure that accompany partial dehydration are similar to those that occur during protein action
Genetic Analysis of Some Morphological Traits in Egyptian Clover (\u3cem\u3eTrifolium alexandrinum\u3c/em\u3e L.)
Trifolium alexandrinum, commonly known as Berseem or Egyptian clover (2n=2x=16) is an important winter forage legume in India, Pakistan, Turkey, Egypt and Mediterranean region. It is characterized by three ecotypes viz; Mescavi, Fahli and Saidi. Amongst these, Mescavi type is most popular. In India it is cultivated in about 2 million hectare area.
The major impediment in genetic improvement of berseem is the lack of appreciable genetic variability (Verma and Mishra, 1995; Roy et al., 2004; Malaviya et al., 2005). Although limited, variability for desirable traits at intraspecific (T. alexandrinum var Fahli and var Saidi) has been reported, considerable variability exists at interspecific level. Affinity of T. alexandrinum was tested with different wild Trifolium species (Malaviya et al., 2005) and was successfully hybridized with T. apertum for transfer of desirable traits such as late maturity and root rot resistance (Malaviya et al., 2004). In the segregating population of the cross, novel morphological traits such as black seed coat colour were also observed (Malaviya et al., 2012). T. alexandrinum var Fahli is single cut type and has several desirable characteristics like self compatibility (even not requiring tripping), good plant height, better seed yield, apical branching, etc.
For incorporation of desirable genes in the improved genepool of beseem, the study of inheritance pattern of traits under consideration is a prerequisite. Therefore, present study was undertaken to study the inheritance pattern of pentafoliate leaf, dark green colour of leaf, black seed coat colour and regeneration capacity
Breeding Strategies to Improve Fodder Legumes with Special Emphasis on Clover and Medics
In India, Forage has a unique integration of agriculture and animal industry in diversified rich cultural environment. Greater part of rural economy in India relies much upon mixed farming system, a well-knit combination of crop production and livestock rearing. In India, grazing-based livestock husbandry plays an important role in the rural economy as around 50% of animals depend on grazing. Pasturelands over an area of 12 Mha constitute the main grazing resources that are available. Nearly 30 pastoral communities in hilly or arid/semi-arid regions in northern and western parts of India, depend on grazing-based livestock production. Nomadic pastoralism, a traditional form of human-livestock-grassland interaction, is still predominant in the drylands of western India, the Deccan Plateau, and in the mountainous reaches of the Himalayas. (Roy and Singh, 2013)
Effect of three decade long application of chemical fertilizer and amendments on crop yield under maize - wheat cropping system in an acid alfisol
The results on the effect of three decade long term application of chemical fertilizers and amendments on the yield of continuous maize-wheat crop rotation in an acid alfisol at Palampur revealed that continuous omission of essential nutrients in a maize-wheat sequence resulted in an appreciable decline in the grain yield of maize and wheat crops. A remarkable reduction in crop yield was noticed in plots where nitrogen was applied alone. Use of recommended level of N alone through urea had deleterious effect on crop productivity. The continuous exhaustionof native pools of K in 100% NP treated plots appreciably reduced percent grain yield. Application of farmyard manure (FYM) and lime along with NPK fertilizers increased the crop yield. The integrated use of optimal dose of NPK and FYM give better and more sustainable yields
Rejuvenation of Rangelands – Role of Diversity and Improvement Strategies of Range Grasses
In India, a major part of the rural economy is dependent on the grazing-based livestock husbandry which is unique integration of agriculture and livestock coupled with rich traditional knowledge. Ecosystems of common property resources had been a mainstay in rural economy and livelihood. The traditional grazing forage resources in arid and semi-arid regions have deteriorated a lot due to various factors including heavy grazing pressure, climate change and dominance of invasive species, thus, needs rejuvenation. Additionally, these are causing serious economic and ecological problems such as poor productivity, soil and water erosion and reduced carbon sequestration.
The genetic improvement of these grasses encounters various problems such as polyploidy, apomixis, seed shedding and shattering and poor seed to ovule ratio. Transfer of desirable traits from donor germplasm becomes difficult due to the existence of apomixis. The breeding objectives are also multifold including herbage yield, forage nutritional quality, abiotic stress tolerance etc. Identification of sexual lines is prerequisite for transfer of traits. Mutation attempts are also not effective due to polyploidy. ICAR- Indian Grassland and Fodder Research Institute, Jhansi has collected rich genetic diversity in these range grasses especially Dichanthium-Bothriochloa complex, Heteropogon, Chrysopogon, Sehima, Panicum, Cenchrus, Pennisetum etc. from different parts of the country as well as procurement from gene banks of the world. These germplasm were evaluated for morphological traits which indicated the existence of wide variation for various morpho-agronomic traits. The paper deals with reporting the extent of variability among the potential range grasses; with prospects of utilizing the diversity in rejuvenating the degraded rangelands of India and other places with isoclimatic conditions
Conservation of Grassland Plant Genetic Resources through People Participation
Agrobiodiversity provides the foundation of all food and feed production. Hence, need of the time is to collect, evaluate and utilize the biodiversity globally available. Indian sub-continent is one of the world’s mega centers of crop origins. India possesses 166 species of agri-horticultural crops and 324 species of wild relatives. India is reported to have five grass covers identified. There have been almost nil human interference in terms of selection pressure; hence, the biodiversity is well conserved in these grazing lands. There is need of a system approach to understanding biodiversity that moves significantly beyond taxonomy and species observations. In addition to forage value, many grasses hold the medicinal value. Duplication in the collected germplasm is a serious issue. Hence, molecular tools need to be employed. Indian Grassland and Fodder Research Institute, Jhansi is maintaining \u3e 8500 germplasm of many fodder crops. For thousands of years farmers have been domesticating plant species thereby developing a wide range of crop varieties adapted to specific needs and environmental conditions and their rights have been protected through Indian Plant Variety Protection and Farmer’s Right Act. The use of diverse species and varieties by farmers enhances their adaptability and resilience capacity to changing environmental and economic conditions. Farmers in Manipur are conserving the biodiversity of the state by farming around 100 traditional varieties of paddy and rare medicinal plants. Old grasslands are very good place of conservation. Southern India forms the important genetic resource centre for many grass crops which includes cereals, millets, sugarcane, lemon grass, ginger grass etc. farmers in Maharastra are also conserving PGR and maintaining Biodiversity Register of the grassland species under guidance of Samvedana. “Community based conservation” and “peoples’ participation” have become part of the conventional rhetoric. Wealth of segregating breeding population also need to be conserved. The grasses or other species in grasslands are growing in highly diverse and harsh condition. These are harbouring genes for tolerance to many abiotic stresses such as light, heat and salinity/alkalinity. Hence, this wide variability, if conserved suitably, can prove to be resource to address climate change issue
Kinetics of Heterogeneous Reaction between o-Toluidine Nitrate & Red Fuming Nitric Acid
291-29
Potential of C4 Tropical Grasses to Contribute in Carbon Sequestration, Environmental Security and Livelihood Opportunities through Increased Fodder Availability
The world grasslands/rangeland ecosystems comprise 26% of earth’s surface and have immense ecological and economic significance. Diversity of grasslands had been a key element for their sustainability. Grasslands in India have existed as natural ecosystems for millions of years. It is a major source of income, employment and livelihood to the rural families. Owing to heavy grazing pressure, coupled with other social/anthropogenic factors, the grazing resources have fast deteriorated. The country has many old and natural grasslands with ethnic and economic value. Comprehensive ecological studies including floristic compositions, dominant species, grazing pressure and the climax/sub-climax stages of ecological succession will surely provide prescriptions for developing and rejuvenating these grazing resources. Grasslands face challenges in arid, semiarid and the moist lowlands with trees, shrubs and many invasive species including alien trees and shrubs introduced intentionally or unintentionally. Fast degrading rangelands in dry areas is causing a threat to huge amount of carbon stored in the top soil on earth in addition to threat to global hotspots for biodiversity. In the context of fast changing climate, the grazing lands can play a significant role. High water use efficiency and productivity of most C4 tropical grasses make them suitable for coping with climate change along with quality fodder
Bulk Entanglement Entropy and Matrices
Motivated by the Bekenstein Hawking formula and the area law behaviour of
entanglement entropy, we propose that in any UV finite theory of quantum
gravity with a smooth spacetime, the total entropy for a pure state in a
co-dimension one spatial region, to leading order, is given by , where is the area of the co-dimension two boundary. In the context
of brane holography we show that for some specially chosen regions bulk
entanglement can be mapped to ``target space" entanglement in the boundary
theory. Our conjecture then leads to a precise proposal for target space
entanglement in the boundary theory at strong coupling and large . In
particular it leads to the conclusion that the target space entanglement would
scale like which is quite plausible in a system with degrees
of freedom. Recent numerical advances in studying the D0 brane system hold out
the hope that this proposal can be tested in a precise way in the future.Comment: Submitted 11 March 2020 to the Peter Freund Memorial Volume. J Phys
Frobenius theorem and invariants for Hamiltonian systems
We apply Frobenius integrability theorem in the search of invariants for
one-dimensional Hamiltonian systems with a time-dependent potential. We obtain
several classes of potential functions for which Frobenius theorem assures the
existence of a two-dimensional foliation to which the motion is constrained. In
particular, we derive a new infinite class of potentials for which the motion
is assurately restricted to a two-dimensional foliation. In some cases,
Frobenius theorem allows the explicit construction of an associated invariant.
It is proven the inverse result that, if an invariant is known, then it always
can be furnished by Frobenius theorem
- …