1,560 research outputs found
Fixed-step anonymous overtaking and catching-up
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
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
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
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
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
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 . The burst
appears to be of very low energy ( ergs) confined to a narrow
cone of opening angle . 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
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
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
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
( 29.5 Mpc) galaxy NGC 2770. Analysis of the photometric observations
revealed this explosion as an energetic event with peak absolute R band
magnitude , which is about one mag brighter than the mean value
() derived for well observed Type Ibc events. The SN is highly
extinguished, E(B-V) = 0.630.15 mag, mainly due to foreground material
present in the host galaxy. From optical light curve modeling we determine that
about 0.3 M radioactive Ni is produced and roughly 4.4
M material is ejected during this explosion with liberated energy
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 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, yr, 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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