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Search Results: 1 - 10 of 7545 matches for " Arpita Das "
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A novel vague set approach for selective contrast enhancement of mammograms using multiresolution  [PDF]
Arpita Das, Mahua Bhattacharya
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.28083
Abstract: The proposed algorithm introduces a novel vague set approach to develop a selective but robust, flexible and intelligent contrast enhancement technique for mammograms. Wavelet based filtering analysis can produce Low Frequency (LF) and High Frequency (HF) subbands of the original input images. The extremely small size microcalcifications become visible under multiresolution techniques. LF subband is then fuzzified by conventional fuzzy c-means clustering (FCM) algorithm with justified number of clusters. HF components, representing the narrow protrusions and other fine details are also fuzzified by FCM with justified number of clusters. Vague set approach captures the hesitancies and uncertainties of truly affected masses/other breast abnormalities with normal glandular tissues. After highlighting the masses/microcalcifications accurately, both LF and HF subbands are transformed back to the original resolution by inverse wavelet transform. The results show that the proposed method can successfully enhance the selected regions of mammograms and provide better contrast images for visual interpretation.
Microbial Removal of Phenol and P-Chlorophenol from Industrial Waste Water Using Rhodococcus sp.RSP8 and Its Growth Kinetic Modeling  [PDF]
Pronoy Kumar Sinha, Arpita Sinha, Manas Das
Journal of Water Resource and Protection (JWARP) , 2011, DOI: 10.4236/jwarp.2011.38073
Abstract: A phenol-degrading microorganism, Rhodococcus sp.RSP8, was used to study the substrate interactions during cell growth on phenol and p-chlorophenol dual substrates. Both phenol and p-chlorophenol could be utilized by the bacteria as the sole carbon and energy sources. When cells grew on the mixture of phenol and p-chlorophenol, strong substrate interactions were observed. The p-chlorophenol inhibited the degradation of phenol, on the other hand, phenol also inhibited the utilization of p-chlorophenol. The overall cell growth rate depends on the co-actions of phenol and p-chlorophenol. In addition, the cell growth and substrate degradation kinetics of phenol, p-chlorophenol as single and mixed substrates for Rhodococcus sp.RSP8 in batch cultures were also investigated over a wide range of initial phenol concentrations (5-1600 mg.L–1) and initial p-chlorophenol concentrations (5 – 250 mg.L–1). The single-substrate kinetics was described well using the Haldane-type kinetic models, with model constants of µm1 = 0.15 h–1, KS1 = 2.22 mg.L–1 and Ki1 = 245.37 mg.L–1 for cell growth on phenol and of µm2 = 0.0782 h–1, KS2 = 1.30 mg.L–1 and Ki2 = 71.77 mg.L–1, K′i2 = 5480 (mg.L–1)2 for cell growth on p-chlorophenol. Proposed cell growth kinetic model was used to characterize the substrates interactions in the dual substrates system.
Soft Computing Based Decision Making Approach for Tumor Mass Identification in Mammogram
Mahua Bhattacharya,Arpita Das
International Journal of Bioinformatics Research , 2009,
Abstract: An intelligent computer aided diagnosis system can be very helpful for radiologist in detecting anddiagnosing breast cancer faster than typical screening program. This study attempted to segment themasses accurately and distinguish malignant from benign masses. The suspicious location of the breastmasses are specified by the radiologists and then masses are accurately segmented using fuzzy c-meansclustering technique. Fourier descriptors are utilized for the extraction of shape features of mammographicmasses. These shape features along with the texture features are fed to the input of the ANFIS classifier fordetermination of the masses as benign, lobular or malignant. The classification system utilizes a simpleEuclidian distance metric to determine the degree of malignancy. The study involves 40 digitizedmammograms from MIAS, BIRADS database and has to be found 87% correct classification rate.
Insight to the Mode of Action of Allium sativum Leaf Agglutinin (ASAL) Expressing in T3 Rice Lines on Brown Planthopper  [PDF]
Arpita Bala, Amit Roy, Niranjana Behura, Daniel Hess, Sampa Das
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.42A052
Abstract:

Brown planthopper, the sap sucking hemipteran pest, is one of the major contributors to the yield loss of rice through the world. To combat the situation researchers are interested identifying genes from plant origin having potentiality to develop hemipteran pest resistance. Interestingly, it was observed that rice plants expressing ASAL, a monocot mannose binding lectin, showed significant resistance to brown planthopper and green leafhopper. Additionally, antibiotic resistant marker gene free ASAL expressing rice lines were developed to overcome the biosafety issues. However, the basis behind the resistance against planthoppers is still not clearly understood. Ligand blot assay was performed with total BBMV protein from BPH and a ~56 kDa receptor protein was detected. LC MS/MS analysis revealed that the receptor protein is NADH quinone oxidoreductase (NQO), a key player in electron transport chain, insect defense response and male/female gametogenesis. Presumably interaction of ASAL with NQO may lead to toxicity and loss of fecundity among BPH feeding on ASAL expressing transgenic rice plants. These findings provide a stable scientific basis for considering these transgenic ASAL expressing rice plants as significant product for combating BPH attack associated yield loss of rice.

An Economic Analysis of Stevia (Stevia rebaudiana Bert.) Cultivation through Stem Cutting and Tissue Culture Propagule in India
Arpita Das,Mainak Biswas,Nirmal Mandal
Trends in Agricultural Economics , 2010,
Abstract: The present study has been formulated to study the cost of cultivation of stevia to encourage the farmer regarding cultivation of this plant and also provide information regarding profitability of cultivation. Stevia become a potential and renewable raw material in the food market because the increase in the number of diabetic and health conscious individual boost up the international market of high quality stevia leaves which is a non-caloric natural sugar. Lack of information regarding the cost of cultivation of stevia specially in Indian context generate plenty of confusion with regard to cultivation of this plant and also about selection of the profitable propagating material. The present study thus concerned with calculating the cost of cultivation, return and cost benefit ratio to identify economic viability and technical feasibility of stevia cultivation through cutting and tissue culture propagated planting material. For this an experimental plot size of 100x100 m each was used for cultivation for 3 years with cutting and tissue cultured plantlets as propagating material. The cost of cultivation refers to the total expenses incurred in cultivating stevia, expressed on a per hectare basis and worked out using operation wise approach in both the cases for three years. Lastly benefit cost ratio was incurred which is the ratio of the present worth of gross costs and represents the economic viability of the two projects. From the two project it was revealed that fixed as well as variable cost was more in tissue culture plantlets propagated field but tissue cultured plants favour disease free clean cultivation with high foliage production as compared with cutting where disease and pest infection was severe. For this during three years of economic life total sales of dry stevia leaves was generate more income in tissue cultured propagule established fields than cutting propagated field. From the cost benefit ratio of the two projects it was clear that profit of the two projects was comparable with each other and was technically feasible and economically viable.
PHARMACOGNOSTICAL AND PHYTOCHEMICAL SCREENING OF TRIKATU HERBS THE HEALING TOUCH OF AYURVEDA
Das Arpita,Mukerjee Tirtha,Sadhu Saugata
International Journal of Research in Ayurveda and Pharmacy , 2011,
Abstract: Ayurveda, arguably the oldest system of rnedicine in the world, frequently uses fixed combinations of herbs. An important ingredient of many recipes, some of which date back to 6000 BC, is 'Tlikatu' (Sanskrit, meaning 'three acrid'). Which is a mixture of black pepper Piper nigrum; long pepper, Piper longum; and ginger, Zingiber ofticinale; the reason for the inclusion of these has recently been examined and a theory for their use proposed which involves enhancement of bioavailability. The bioavailability enhancement probably results from the fact that piperine is a poter inhibitor of drug metabolism.
HEPATOTOXICITY AND HEPATOPROTECTISM HERBS: HERBAL REMIDIES
Das Arpita,Biswas Pritam,Chakrabarty Panjal
International Journal of Research in Ayurveda and Pharmacy , 2011,
Abstract: Liver disorders are serious health problem most common form occurring in people of all ages. Hepatotoxicity implies chemical-driven liver damage.Liver is the largest organ in the body is being evolved to maintain the body’s internal milieu and also protect itself from the challenges it faces during its functioning.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure the organ. Other chemical agents, such as those used in laboratories and industries, natural chemicals (e.g. microcystins) and herbal remedies can also induce hepatotoxicity. Chemicals that cause liver injury are called hepatotoxins.Herbal-based therapeutics for liver disorders has been in use in India for a long time and has been popularized world over by leading pharmaceuticals. Despite the significant popularity of several herbal medicines in general, and for liver diseases in particular, they are still unacceptable treatment modalities for liver diseases.
Vacuum-Induced Coherence in Ultracold Photoassociative Ro-Vibrational Excitations
Sumanta Das,Arpita Rakshit,Bimalendu Deb
Physics , 2011, DOI: 10.1103/PhysRevA.85.011401
Abstract: We show that coherence between two excited ro-vibrational states belonging to the same molecular electronic configuration arises quite naturally due to their interaction with electromagnetic vacuum. For initial preparation of a molecule in the desired ro-vibrational states, we propose to employ the method of ultracold photoassociation. Spontaneous decay of the excited molecule then gives rise to vacuum induced coherence between the excited ro-vibrational states. We demonstrate theoretically an interesting interplay of effects due to vacuum induced coherence and photoassociation. We apply our theory to photoassociation of bosonic Ytterbium (^{174}Yb) atoms which appear to be a promising system for exploring such interplay. The effects discussed here can be important for controlling decoherence and dissipation in molecular systems.
Diaspora, a large family of Ty3-gypsy retrotransposons in Glycine max, is an envelope-less member of an endogenous plant retrovirus lineage
Sho T Yano, Bahman Panbehi, Arpita Das, Howard M Laten
BMC Evolutionary Biology , 2005, DOI: 10.1186/1471-2148-5-30
Abstract: Diaspora is a multicopy member of the Ty3-gypsy-like family of LTR retrotransposons and comprises at least 0.5% of the soybean genome. Although the Diaspora family is highly degenerate, and with the exception of this report, is not represented in the Genbank nr database, a full-length consensus sequence was generated from short overlapping sequences using a combination of experimental and in silico methods. Diaspora is 11,737 bp in length and contains a single 1892-codon ORF that encodes a gag-pol polyprotein. Phylogenetic analysis indicates that it is closely related to Athila and Calypso retroelements from Arabidopsis and soybean, respectively. These in turn form the framework of an endogenous retrovirus lineage whose members possess an envelope-like gene. Diaspora appears to lack any trace of this coding region.A combination of empirical sequencing and retrieval of unannotated Genome Survey Sequence database entries was successfully used to construct a full-length representative of the Diaspora family in Glycine max. Diaspora is presently the only fully characterized member of a lineage of putative plant endogenous retroviruses that contains virtually no trace of an extra coding region. The loss of an envelope-like coding domain suggests that non-infectious retrotransposons could swiftly evolve from infectious retroviruses, possibly by anomalous splicing of genomic RNA.Eukaryotic genomes are littered with dozens to tens of thousands of copies of reverse transcriptase (RT)-based retroelements [1-3]. Among these are a diverse collection of elements characterized by long terminal repeats (LTR) that include the Ty1-copia-like and Ty3-gypsy-like retrotransposon families, endogenous retroviruses, and mammalian lentiviruses [4]. LTR retrotransposons have been especially successful colonizers of the chromosomes of higher plants where they constitute as much as 80% of these genomes [3,5-7]. In soybean, several families of LTR retrotransposons have been identified [8-10],
Improving Rain Attenuation Estimation: Modelling of Effective Path Length Using Ku-Band Measurements at a Tropical Location
Arpita Adhikari;Saurabh Das;Aniruddha Bhattacharya;Animesh Maitra
PIER B , 2011, DOI: 10.2528/PIERB11072503
Abstract: Rain attenuation is an important aspect of signal propagation above 10 GHz frequency. The attenuation time series generation from point rain rate measurement is crucial due to unavailability of actual signal measurements. In this paper, a simple and realistic approach has been demonstrated for better estimation of rain attenuation using Ku-band signal propagation data and ground rain rate measurements at Kolkata, India. The ITU-R model of rain attenuation has been modified by incorporating an effective slant path model. The effective slant path has been estimated and modelled in terms of a power-law relationship of rain rate data of 2007-2008. The methodology has been validated with the measured data of 2006. Comparison with ITU-R and SAM clearly demonstrates the improved predictability of the proposed model at the present tropical location.
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