8,302 research outputs found
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Leptodactylus knudseni
Number of Pages: 12Integrative BiologyGeological Science
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Leptodactylus lithonaetes
Number of Pages: 3Integrative BiologyGeological Science
Re-examining Larson's Scaling Relationships in Galactic Molecular Clouds
The properties of Galactic molecular clouds tabulated by Solomon etal (1987)
(SRBY) are re-examined using the Boston University-FCRAO Galactic Ring Survey
of 13CO J=1-0 emission. These new data provide a lower opacity tracer of
molecular clouds and improved angular and spectral resolution than previous
surveys of molecular line emission along the Galactic Plane. We calculate GMC
masses within the SRBY cloud boundaries assuming LTE conditions throughout the
cloud and a constant H2 to 13CO abundance, while accounting for the variation
of the 12C/13C with Galacto-centric radius. The LTE derived masses are
typically five times smaller than the SRBY virial masses. The corresponding
median mass surface density of molecular hydrogen for this sample is 42
Msun/pc^2, which is significantly lower than the value derived by SRBY (median
206 Msun/pc^2) that has been widely adopted by most models of cloud evolution
and star formation. This discrepancy arises from both the extrapolation by SRBY
of velocity dispersion, size, and CO luminosity to the 1K antenna temperature
isophote that likely overestimates the GMC masses and our assumption of
constant 13CO abundance over the projected area of each cloud. Owing to the
uncertainty of molecular abundances in the envelopes of clouds, the mass
surface density of giant molecular clouds could be larger than the values
derived from our 13CO measurements. From velocity dispersions derived from the
13CO data, we find that the coefficient of the cloud structure functions,
vo=sigma_v/R^{1/2}, is not constant, as required to satisfy Larson's scaling
relationships, but rather systematically varies with the surface density of the
cloud as Sigma^{0.5} as expected for clouds in self-gravitational equlibrium.Comment: Accepted by ApJ. Newest version includes modifications from the
refere
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Leptodactylus cunicularius
Number of Pages: 5Integrative BiologyGeological Science
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Leptodactylus savagei
Number of Pages: 19Integrative BiologyGeological Science
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Leptodactylus pentadactylus
Number of Pages: 48Integrative BiologyGeological Science
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Leptodactylus syphax
Number of Pages: 9Integrative BiologyGeological Science
The Changing Position of Agricultural Labourers in Villages in Rural Coimbatore, Tamil Nadu, between 1981/2 and 1996
This paper looks at agricultural labourers in villages in Coimbatore district in 1981/2 and in 1996. It focuses on Chakkiliyans, the lowest status and most numerous Scheduled Caste group. It shows that while their position had barely changed over the decades prior to 1981/2, between 1981/2 and 1996 it changed dramatically, albeit less dramatically than one might have expected given all that was going on. 1981/2 to 1996 was a period in which (1)industrial and urban opportunities became available to virtually all labourers in the villages for the first time; (2)state policy became more favourable to labourers; and (3)village agriculture declined. The position of Chakkiliyans' agricultural employers weakened considerably between 1981/2 and 1996, but Chakkiliyans nevertheless found it difficult to stand up to them. This was partly because they were still getting a relatively attractive agricultural employment package in 1996, partly because they were in such a weak position in relation to alternative opportunities. Chakkiliyans found 'flexible' urban and industrial labour markets problematic because risky and available only on terms that were harsh. Moreover, housing and increased indebtedness in the villages resulted in Chakkiliyans being tied in some ways more strongly to agricultural employment in 1996 than in 1981/2. Other low caste labourers were getting urban and industrial opportunities that were likely to give them better prospects in the longer term. Chakkiliyans were not. The paper also considers the position of the two other groups of agricultural labourers in the villages in 1981/2, and their descendants in 1996. These were (1) a higher status Scheduled Caste group, Pannadis, and (2) a group of Caste Hindus. The contrast between the three 1981/2 labourer groups is illuminating, illustrating the important role played by caste and the way it operates in this context.
Welfare Standards and Merger Analysis: Why not the Best?
Over the past several decades, there has emerged a rough consensus among professional antitrust practitioners, and within the law and economics community generally, that the "competition" referred to in our antitrust statutes is not to be interpreted simply as pre-merger rivalry among entities. Rather, it is best viewed as a process, the outcome of which is welfare, with welfare-not "rivalry"--being the object of interest. Consistent with this interpretation, scholars, competition authorities, and the courts have come to treat antitrust law as condemning only those mergers whose effect may be substantially to reduce welfare. That having been said, there remains a question of which welfare standard to use, and exactly whose welfare to consider. Several candidates suggest themselves. I argue in this paper for using the so-called "Total Welfare" standard, rather than the more commonly employed "Consumer Welfare" standard. In doing so, I respond to three broad objections that have been raised. One is that use of a total welfare standard conflicts with antitrust law, or at least with legal precedent. A second is that employing a total welfare standard would be more costly for antitrust agencies than employing one or another flavor of a consumer welfare standard. A third is that the total welfare standard ignores important distributional considerations-considerations that are better treated under some form of consumer welfare standard. Each of these objections is evaluated, and ultimately found unpersuasive.
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