1,560 research outputs found

    Fixed-step anonymous overtaking and catching-up

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    We investigate criteria for evaluating infinite utility streams that satisfy Fixed-step anonymity and includes some notion of overtaking or catching-up. We do so in a generalized setting which do not require us to specify the underlying finite-dimensional criterion (e.g., utilitarianism or leximin). We present axiomatizations that rely on weaker axioms than those in the literature, and which in one case is new. We also provide a complete analysis of the relationships between the symmetric parts of these criteria and likewise for the asymmetric parts.Intergenerational justice; Utilitarianism; Leximin

    Generalized time-invariant overtaking

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    We present a new version of the overtaking criterion, which we call generalized time-invariant overtaking. The generalized time-invariant overtaking criterion (on the space of infinite utility streams) is defined by extending proliferating sequences of complete and transitive binary relations defined on finite dimensional spaces. The paper presents a general approach that can be specialized to at least two, extensively researched examples, the utilitarian and the leximin orderings on a finite dimensional Euclidean space.intergenerational justice, utilitarianism, leximin

    Generalized time-invariant overtaking

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    We present a new version of the overtaking criterion, which we call generalized time-invariant overtaking. The generalized time-invariant overtaking criterion (on the space of infinite utility streams) is defined by extending proliferating sequences of complete and transitive binary relations defined on finite dimensional spaces. The paper presents a general approach that can be specialized to at least two, extensively researched examples, the utilitarian and the leximin orderings on a finite dimensional Euclidean spaceintergenerationa justice; utilitarianism, leximin

    Generalized time-invariant overtaking

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    We present a new version of the overtaking criterion, which we call generalized time-invariant overtaking. The generalized time-invariant overtaking criterion (on the space of infinite utility streams) is defined by extending proliferating sequences of complete and transitive binary relations defined on finite dimensional spaces. The paper presents a general approach that can be specialized to at least two, extensively researched examples, the utilitarian and the leximin orderings on a finite dimensional Euclidean space.Intergenerational justice; Utilitarianism; Leximin

    Generalized time-invariant overtaking

    Get PDF
    We present a new version of the overtaking criterion, which we call generalized time invariant overtaking. The generalized time-invariant overtaking criterion (on the space of infinite utility streams) is defined by extending proliferating sequences of complete and transitive binary relations defined on finite dimensional spaces. The paper presents a general approach that can be specialized to at least two, extensively researched examples, the utilitarian and the leximin orderings on a finite dimensional Euclidean space.intergenerational justice, utilitarianism, leximin.

    Optical Observations and Multiband Modelling of the Afterglow of GRB 041006: Evidence of A Hard Electron Energy Spectrum

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    We present the CCD Cousins R band photometric observations of the afterglow of GRB 041006. The multiband afterglow evolution is modelled using an underlying `hard' electron energy spectrum with a p11.3p_1 \sim 1.3. The burst appears to be of very low energy (E1048E \sim 10^{48} ergs) confined to a narrow cone of opening angle θ2.3\theta \sim 2.3^{\circ}. The associated supernova is compared with SN1998bw and is found to be brighter.Comment: Accepted for publication in Bull. Astr. Soc. India (BASI

    Synthesis of benzothiazolopyrazoloisonicotinohydrazide derivatives and their nitro regioisomers for antitubercular activity

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    1388-1399The history of incessant struggle and the current global burden associated with emerging infectious disease especially tuberculosis, guided us to define the scope of this research project, and to identify research gaps in synthesizing some heterocyclic compounds for anti-tubercular activity. In this research project, we have synthesized a series of novel heterocyclic (benzothiazoles) compounds viz N'-((1-(7-chloro-6-fluorobenzo[d]thiazol-2-yl)-3-phenyl-1H-pyrazol-4-yl) methylene)isonicotinohydrazide 12a-c their 5-nitro 15a-c and 4-nitro 18a-c derivatives, by a series of reactions of their respective synthons. The completion of reaction and the purity of the synthesized compounds have been established by chromatographic analysis. All the newly synthesized compounds satisfactorily show acceptable analysis for their anticipated structures, which have been confirmed based on physicochemical and spectral data. These newly synthesized compounds have been primarily evaluated for their in vitro anti-tubercular activity by Ziehl-Neelsen stain method. Compounds 15a, 15b, 15c, 18b and 18c have shown 100% inhibition at 25 mg/ mL and MIC values of around 45 nM against M. tuberculosis H37Rv (ATCC 27294). Cytotoxicity on THP-1 cell line shows that all the tested compounds are safe

    Synthesis of benzothiazolopyrazoloisonicotinohydrazide derivatives and their nitro regioisomers for antitubercular activity

    Get PDF
    The history of incessant struggle and the current global burden associated with emerging infectious disease especially tuberculosis, guided us to define the scope of this research project, and to identify research gaps in synthesizing some heterocyclic compounds for anti-tubercular activity. In this research project, we have synthesized a series of novel heterocyclic (benzothiazoles) compounds viz N'-((1-(7-chloro-6-fluorobenzo[d]thiazol-2-yl)-3-phenyl-1H-pyrazol-4-yl) methylene)isonicotinohydrazide 12a-c their 5-nitro 15a-c and 4-nitro 18a-c derivatives, by a series of reactions of their respective synthons. The completion of reaction and the purity of the synthesized compounds have been established by chromatographic analysis. All the newly synthesized compounds satisfactorily show acceptable analysis for their anticipated structures, which have been confirmed based on physicochemical and spectral data. These newly synthesized compounds have been primarily evaluated for their in vitro anti-tubercular activity by Ziehl-Neelsen stain method. Compounds 15a, 15b, 15c, 18b and 18c have shown 100% inhibition at 25 mg/ mL and MIC values of around 45 nM against M. tuberculosis H37Rv (ATCC 27294). Cytotoxicity on THP-1 cell line shows that all the tested compounds are safe.

    SN 2007uy - metamorphosis of an aspheric Type Ib explosion

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    The supernovae of Type Ibc are rare and the detailed characteristics of these explosions have been studied only for a few events. Unlike Type II SNe, the progenitors of Type Ibc have never been detected in pre-explosion images. So, to understand the nature of their progenitors and the characteristics of the explosions, investigation of proximate events are necessary. Here we present the results of multi-wavelength observations of Type Ib SN 2007uy in the nearby (\sim 29.5 Mpc) galaxy NGC 2770. Analysis of the photometric observations revealed this explosion as an energetic event with peak absolute R band magnitude 18.5±0.16-18.5\pm0.16, which is about one mag brighter than the mean value (17.6±0.6-17.6\pm0.6) derived for well observed Type Ibc events. The SN is highly extinguished, E(B-V) = 0.63±\pm0.15 mag, mainly due to foreground material present in the host galaxy. From optical light curve modeling we determine that about 0.3 M_{\odot} radioactive 56^{56}Ni is produced and roughly 4.4 M_{\odot} material is ejected during this explosion with liberated energy 15×1051\sim 15\times10^{51} erg, indicating the event to be an energetic one. Through optical spectroscopy, we have noticed a clear aspheric evolution of several line forming regions, but no dependency of asymmetry is seen on the distribution of 56^{56}Ni inside the ejecta. The SN shock interaction with the circumburst material is clearly noticeable in radio follow-up, presenting a Synchrotron Self Absorption (SSA) dominated light curve with a contribution of Free Free Absorption (FFA) during the early phases. Assuming a WR star, with wind velocity \ga 10^3 {\rm km s}^{-1}, as a progenitor, we derive a lower limit to the mass loss rate inferred from the radio data as \dot{M} \ga 2.4\times10^{-5} M_{\odot}, yr1^{-1}, which is consistent with the results obtained for other Type Ibc SNe bright at radio frequencies.Comment: 22 pages, 13 figures, accepted for publication in MNRA
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