31 research outputs found

    Transition from Modernity to Post-modernity

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    The era of enlightenment is known as “mother of modernityâ€. It has promoted human rationality, scientific development, and human supremacy and paves the way for the decline of religious understanding of the society. The rise of human rationality, materialization of industry, invention of printing press and rising trend of democratic principle, emerging market economy and technological development are characterised as modernity.  The idea of modernity is first stage of human era where human beings were treated as supreme authority of their spheres. With modernity, the concept of nation/state emerged which has the credit to organise the world, promote the rights of the individuals and pay its emphasis on the construction of the democratic society, participatory politics and free individuals. But modernity is criticised by scholars like Perry Anderson, who argue that modernity has actually created another layer and made society absolute. It has inserted empirical documentation and rejected the persons’ observation, including local reality. With these critiques, post-modernity emerged which has questioned the foundation of modernity. It advocated for ‘bottom to approach’ unlike modernity. The main objective of this paper to analysed the main tenets of modernity and discuss the actual principle of post-modernity. This analytical paper concludes with the major critics of post-modernity by taking the author’s understanding about modernity and post-modernity

    High Energy Emission Processes in OJ 287 during 2009 Flare

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    The broadband spectrum of a BL Lac object, OJ 287, from radio to γ\gamma-rays obtained during a major γ\gamma-ray flare detected by \emph{Fermi} in 2009 are studied to understand the high energy emission mechanism during this episode. Using a simple one-zone leptonic model, incorporating synchrotron and inverse Compton emission processes, we show that the explanation of high energy emission from X-rays to γ\gamma-rays, by considering a single emission mechanism, namely, synchrotron self-Compton (SSC) or external Compton (EC) requires unlikely physical conditions. However, a combination of both SSC and EC mechanisms can reproduce the observed high energy spectrum satisfactorily. Using these emission mechanisms we extract the physical parameters governing the source and its environment. Our study suggests that the emission region of OJ 287 is surrounded by a warm infrared (IR) emitting region of 250K\sim 250 \, K. Assuming this region as a spherical cloud illuminated by an accretion disk, we obtain the location of the emission region to be 9pc\sim 9 pc. This supports the claim that the γ\gamma-ray emission from OJ 287 during the 2009 flare arises from a location far away from the central engine as deduced from millimeter-gamma ray correlation study and very long baseline array images.Comment: 22 pages, 7 figures, 1 table, accepted for publication in MNRA

    Brightest Fermi-LAT Flares of PKS 1222+216: Implications on Emission and Acceleration Processes

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    We present a high time resolution study of the two brightest γ\gamma-ray outbursts from a blazar PKS 1222+216 observed by the \textit{Fermi} Large Area Telescope (LAT) in 2010. The γ\gamma-ray light-curves obtained in four different energy bands: 0.1--3, 0.1--0.3, 0.3--1 and 1--3 GeV, with time bin of 6 hr, show asymmetric profiles with a similar rise time in all the bands but a rapid decline during the April flare and a gradual one during the June. The light-curves during the April flare show 2\sim 2 days long plateau in 0.1--0.3 GeV emission, erratic variations in 0.3--1 GeV emission, and a daily recurring feature in 1--3 GeV emission until the rapid rise and decline within a day. The June flare shows a monotonic rise until the peak, followed by a gradual decline powered mainly by the multi-peak 0.1--0.3 GeV emission. The peak fluxes during both the flares are similar except in the 1--3 GeV band in April which is twice the corresponding flux during the June flare. Hardness ratios during the April flare indicate spectral hardening in the rising phase followed by softening during the decay. We attribute this behavior to the development of a shock associated with an increase in acceleration efficiency followed by its decay leading to spectral softening. The June flare suggests hardening during the rise followed by a complicated energy dependent behavior during the decay. Observed features during the June flare favor multiple emission regions while the overall flaring episode can be related to jet dynamics.Comment: 17 pages, 9 figures, 4 tables, accepted for publication in Ap

    Multi-wavelength Temporal Variability of the Blazar 3C 454.3 during 2014 Activity Phase

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    We present a multi-wavelength temporal analysis of the blazar 3C 454.3 during the high γ\gamma-ray active period from May-December, 2014. Except for X-rays, the period is well sampled at near-infrared (NIR)-optical by the \emph{SMARTS} facility and the source is detected continuously on daily timescale in the \emph{Fermi}-LAT γ\gamma-ray band. The source exhibits diverse levels of variability with many flaring/active states in the continuously sampled γ\gamma-ray light curve which are also reflected in the NIR-optical light curves and the sparsely sampled X-ray light curve by the \emph{Swift}-XRT. Multi-band correlation analysis of this continuous segment during different activity periods shows a change of state from no lags between IR and γ\gamma-ray, optical and γ\gamma-ray, and IR and optical to a state where γ\gamma-ray lags the IR/optical by \sim3 days. The results are consistent with the previous studies of the same during various γ\gamma-ray flaring and active episodes of the source. This consistency, in turn, suggests an extended localized emission region with almost similar conditions during various γ\gamma-ray activity states. On the other hand, the delay of γ\gamma-ray with respect to IR/optical and a trend similar to IR/optical in X-rays along with strong broadband correlations favor magnetic field related origin with X-ray and γ\gamma-ray being inverse Comptonized of IR/optical photons and external radiation field, respectively.Comment: 15 pages, 5 figures, 1 table, MNRAS accepte

    DEVELOPMENT OF CAUDAL FIN CELL LINE FROM HILL TROUT Barilius bendelisis (HAMILTON, 1807) FOR CYTOTOXICITY AND TRANSFECTION STUDIES

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    Stanična linija, nazvana BBdF-1, uspostavljena iz repne peraje Barilius bendelisis, presađena je na više od 52 „oblika“(prolaza) a održavala se u medijima L-15 koji sadrže 20% FBS. Porijeklo stanične linije potvrđeno je pomoću pojačanja djelomičnog područja 16S i COI mitohondrijskih genskih sekvenci. Utvrđeno je da je optimalna temperatura za rast stanične linije BBdF-1 28°C. Kariotipizacijom se utvrdio diploidni broj kromosoma kao 50. Stanice su pokazale snažno vezanje za citokeratinski marker i, prema tome, utvrđeno je da sliče epitelu. Jaka zelena fluorescencija primijećena je u stanicama BBdF-1 transficiranim vektorom phrGFP-II-N, što ukazuje da je prikladna za upotrebu u ispitivanjima ekspresije i manipulacije gena. Izvršena je i uspješna procjena citotoksičnosti dvaju teških metala, žive i kroma. Stanična linija može poslužiti kao koristan izvorni materijal za ranu provjeru toksičnosti pesticida/zagađivača i ekspresije gena.A cell line named BBdF-1, established from the caudal fin of hill stream fish Barilius bendelisis, has been subcultured for more than 52 passages and is being maintained in L-15 media containing 20% FBS. Species origin of the cell line was confirmed using amplification of partial region of 16S and COI mitochondrial gene sequences. The optimum temperature for growth of BBdF-1 cell line was found to be 28°C. Karyotyping revealed diploid chromosome number as 50. Cells exhibited strong binding for cytokeratin marker and thus were found to be epithelial-like. Strong green fluorescence was observed in BBdF-1 cells transfected with phrGFP-II-N vector, indicating its suitability for utilization in gene expression and manipulation studies. Successful assessment of cytotoxicity of two heavy metals, viz. mercury and chromium, was performed. The cell line can serve as a useful resource material for early toxicity screening of pesticides/pollutant and gene expression
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