174 research outputs found
On the Second Fundamental Theorem of Asset Pricing
Let be sigma-martingales on . We show
that every bounded martingale (with respect to the underlying filtration)
admits an integral representation w.r.t. if and only if there
is no equivalent probability measure (other than ) under which
are sigma-martingales.
From this we deduce the second fundamental theorem of asset pricing- that
completeness of a market is equivalent to uniqueness of Equivalent
Sigma-Martingale Measure (ESMM)
Enhancement of reactivity and increased usage of low lime class -F-fly ash-possible avenues
The low lime class-F fly ash available in the country shows high degree of variability in the quality, higher content of crystallites , lower glassy phase which accounts for lower of usage in cement and concrete . The time reactivity test used for assessing the pozzolanicity of fly ash did not always correlate with its observed reactivity in Blended cements . An alternative
rapid alkali reactivity rest developed at the authors ' laboratory is illustrated in the paper. The paper also discusses the possibility of increasing the reactivity of fly ash and effect of the reactive fly ash on characteristics of PPC and concrete. The paper further discusses other avenues of fly ash utilisation, which could be categorised as low, medium and high value applications. One of such applications developed at the authors ' laboratory that merits special interest, is the Hydrogel process of clinkerisation , which has a potential for utilisation of 20-30% fly ash as a raw material in cement manufacture
Maturity and spawning period of Thrissocles purava (Ham.) as determined by ova-diameter measurements
The peak period of occurrence of Thrissocles purava (Ham.) in Bombay waters is in two seasons, namely February-April and August-October. The mature, spent and maturing fish are caught in inshore waters in these periods. The post-larval forms are also encountered in the plankton samples taken in these months. During the remaining months a few young, immature specimens are available in small numbers. The range of diameters of immature, maturing and mature ova is from 0.08 mm. to 0.44 mm.; 0.45 mm. to 0.76 mm. and 0.92 mm. to 1.26 mm. respectively. The mature ovaries of this species are found to contain only two groups of ova, namely mature and immature. The spawning season, as determined by the ova diameter measurements and the structure of the mature ovary, is found to be the same as the peak period of occurrence of this species in inshore waters. Relatively high percentages of mature and spent females during this period further supports the view that the species visits the Bombay shores mainly for spawning. The spawning period for individual fish is of a short duration and there is only one spawning a season. The minimum period required for the rematuration of the spent ovaries is about six months. The size at first maturity is found to be about 170 mm
Vertical distribution of atmospheric ozone in low latitudes
This article does not have an abstract
Bilateral total duplication of clavicle: First reported case
A very rare first case of bilateral duplication of the clavicle is presented here. Duplication of the clavicle has been described in only six reports based on a search of the world literature, with single case of bilateral duplication (incomplete) of clavicle being reported. The detection of anatomic anomalies are increasing with the advancement of technology in medicine field. This case is more of academic interest as it is the first case of total bilateral duplication of clavicle
Movie genre classification via scene categorization
ABSTRACT This paper presents a method for movie genre categorization of movie trailers, based on scene categorization. We view our approach as a step forward from using only low-level visual feature cues, towards the eventual goal of high-level semantic understanding of feature films. Our approach decomposes each trailer into a collection of keyframes through shot boundary analysis. From these keyframes, we use state-ofthe-art scene detectors and descriptors to extract features, which are then used for shot categorization via unsupervised learning. This allows us to represent trailers using a bag-of-visual-words (bovw) model with shot classes as vocabularies. We approach the genre classification task by mapping bovw temporally structured trailer features to four high-level movie genres: action, comedy, drama or horror films. We have conducted experiments on 1239 annotated trailers. Our experimental results demonstrate that exploiting scene structures improves film genre classification compared to using only low-level visual features
The 'K' selected oligophilic bacteria: a key to uncultured diversity?
Molecular techniques have made it increasingly clear that a large proportion of bacterial diversity in natural habitats is uncultured and therefore unexplored. We suggest and give evidence in support of a hypothesis that a large proportion, if not all, of the uncultured diversity from a variety of aquatic and terrestrial habitats are oligophilic (oligotrophic) bacteria. Oligophilic bacteria grow only on dilute nutrient media and form small or microscopic colonies. A technique to cultivate and isolate the moderately oligophilic bacteria was developed and 90 cultures isolated, The twelve bacterial cultures characterized showed high growth yield coefficients and carbon conversion efficiencies at low substrate concentrations and progressively decreased with increasing substrate concentrations. Most of the growth yields were substantially higher than those reported in the literature and lie near the theoretical maximum. Slow growth rates and high yields indicate that they are 'K' selected species. 16S rDNA partial sequence analysis of the isolates indicates that it is a novel as well as diverse group
Developmentally regulated cleavage of tRNAs in the bacterium Streptomyces coelicolor
The ability to sense and respond to environmental and physiological signals is critical for the survival of the soil-dwelling Gram-positive bacterium Streptomyces coelicolor. Nutrient deprivation triggers the onset of a complex morphological differentiation process that involves the raising of aerial hyphae and formation of spore chains, and coincides with the production of a diverse array of clinically relevant antibiotics and other secondary metabolites. These processes are tightly regulated; however, the genes and signals involved have not been fully elucidated. Here, we report a novel tRNA cleavage event that follows the same temporal regulation as morphological and physiological differentiation, and is growth medium dependent. All tRNAs appear to be susceptible to cleavage; however, there appears to be a bias towards increased cleavage of those tRNAs that specify highly utilized codons. In contrast to what has been observed in eukaryotes, accumulation of tRNA halves in S. coelicolor is not significantly affected by amino acid starvation, and is also not affected by induction of the stringent response or inhibition of ribosome function. Mutants defective in aerial development and antibiotic production exhibit altered tRNA cleavage profiles relative to wild-type strains
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