10,347 research outputs found

    Algebraic Aspects of Abelian Sandpile Models

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    The abelian sandpile models feature a finite abelian group G generated by the operators corresponding to particle addition at various sites. We study the canonical decomposition of G as a product of cyclic groups G = Z_{d_1} X Z_{d_2} X Z_{d_3}...X Z_{d_g}, where g is the least number of generators of G, and d_i is a multiple of d_{i+1}. The structure of G is determined in terms of toppling matrix. We construct scalar functions, linear in height variables of the pile, that are invariant toppling at any site. These invariants provide convenient coordinates to label the recurrent configurations of the sandpile. For an L X L square lattice, we show that g = L. In this case, we observe that the system has nontrivial symmetries coming from the action of the cyclotomic Galois group of the (2L+2)th roots of unity which operates on the set of eigenvalues of the toppling matrix. These eigenvalues are algebraic integers, whose product is the order |G|. With the help of this Galois group, we obtain an explicit factorizaration of |G|. We also use it to define other simpler, though under-complete, sets of toppling invariants.Comment: 39 pages, TIFR/TH/94-3

    Critical Cooperation Range to Improve Spatial Network Robustness

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    A robust worldwide air-transportation network (WAN) is one that minimizes the number of stranded passengers under a sequence of airport closures. Building on top of this realistic example, here we address how spatial network robustness can profit from cooperation between local actors. We swap a series of links within a certain distance, a cooperation range, while following typical constraints of spatially embedded networks. We find that the network robustness is only improved above a critical cooperation range. Such improvement can be described in the framework of a continuum transition, where the critical exponents depend on the spatial correlation of connected nodes. For the WAN we show that, except for Australia, all continental networks fall into the same universality class. Practical implications of this result are also discussed

    Biochemical genetic profile of the Indian mackerel Rastreliger kanagurta of mud bank and post-mud bank period

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    An attempt was made to study the genetic profile of the Indian mackerel Rastrelliger kanagurta, an economically important fish species of India. The genetic profile of the mackerel caught during the mud bank period was compared to that of the post mud bank period

    Biochemical genetic polymorphism in Indian mackerel (Rastrelliger kanagurta)

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    Six enzymes glucose 6 phosphate dehydrogenase (G6PD), xanthene de hydrogenase (XDH), alcohol dehydrogenase (ADH), peroxidase (PO), lactate dehydrogenase (LDH) and isocitric dehydrogenase (lDH) were examined to discover the genetic variation in Indian mackerel through polyacrylamide gel electrophoresis. A significant difference in allelic frequency at XDH locus was observed between the eachin and Thotapally populations. Thotapally stocks exhibited a significant deviation (P< 0.05) from Hardy weinberg equillibrium. The proportion of polymorphic Joci was 0.777. The coefficient of identity and the genetic distance estimated were 0.9262 and 0.076 respectively

    Biochemical genetic polymorphism in the Indian mackerel Rastrelliger kanagurta from Mangalore region

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    Electrophoresis is the modern and most popular technique used for studying the genetic variability within and among the populations of plants and animals. Genetically controlled tissue enzymes are the most suitable parameters for genetic variability studies. In the present study Polyacrylamide Gel Electrophoresis was used to study the genetic variability in Indian mackerel

    Effect of FYM, foliar feeding of nitrogen and deficit irrigation on drip irrigated coriander (Coriandrum sativum L.)

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    A field experiment was conducted to study the water use, nitrogen (N) uptake and economics of coriander (Coriandrum sativum L.) under organic enrichment, foliar feeding of N and fertigation. Drip irrigation at 80% ETc + foliar spray of 25% N (15 kg ha-1) + fertigation (45 kg ha-1) gave the highest plant height, branch plant-1, umbel plant-1, umbelets umbel-1, seed umbel-1, and test weight compared to irrigation at 80% ETc and at 60% ETc (upto flowering stage) + 80% ETc (reproductive stage) with or without foliar spray. Increased yield parameters were attributed to the highest seed yield and B:C ratio of 1.90 using 265.74 mm water. Water use efficiency (WUE) was also the highest. This treatment also recorded the highest N uptake of 52.6 kg ha-1. Further, addition of 10 t ha-1 FYM in addition to recommended nitrogen dose (60 kg ha-1) gave higher yield attributes viz., branch plant-1, umbel plant-1, seed umbel-1 and test weight as compared to recommended level of fertilizers. Enhanced yield attributes thus increased seed yield, N removal, WUE and B:C ratio. &nbsp

    Knowledge And Opinion About Hiv/Aids Among Long Route Truck Drivers

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    A cross sectional study was carried out on 235 truck drivers operating at Kanpur- Jhansi highway to assess their knowledge and opinion about HIV/AIDS It was observed that about 73% had heard about HIV/AIDS. two third were aware about sexual transmission as the route of transmission. Televison was the main source of their knowledge (76.74%). But knowledge on other aspects of HIV was very less, only one-third were aware about preventive role of condom. Less than half (45.95%) were of the opinion that this disease can be prevented. It was dis heartening to note that (34.46%) were in favor to separate AIDS patient from family and (43.40%) were in favor todivorce spouse having AIDS. Withthis background of Knowledge about half of truck drivers (48.94%) were of the&nbsp
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