11,345 research outputs found
Integrating genomics and phylogenetics in understanding the history of Trichinella species
In 2004, funding was received by Washington University’s Genome Sequencing Center through NHGRI, to completely sequence several nematode genomes as part of a holistic effort to advance our understanding of the human genome and evolution within the Metazoa. Trichinella spiralis was among this group of worms because of its strategic location at the base of the phylum Nematoda, and the belief that extant species represented an ancient divergent event that occurred as early as the Paleozoic. At the same time, a concerted effort was put forth to solidify the phylogeny of extant species of Trichinella based upon molecular analyses of a multi-gene system to understand the history of the genus and thereby enhance utilization of the forthcoming sequence data. Since the inception of this research, several findings have emerged: (1) the size of T. spiralis genome estimated by flow cytometry (71.3 Mb) is substantially smaller than originally predicted (270 Mb); (2) to date, a subset of the total of 3,534,683 sequences have been assembled into a 59.3 Mb unique sequence; (3) 19% of the assembled sequence is comprised of repetitive elements; and (4) sequence data are predicated upon extant T. spiralis which probably diverged as little as 20 million years ago. Thus, the utility of the T. spiralis genome as representative of an archaic species must be tempered with the knowledge that encapsulated and non-encapsulated clades probably separated during the mid-Miocene as temperate ecosystems changed
Perspective: tobacco manufacturers are now compensating states for smoking-related costs: how will this affect the economy?
Smoking out the social and economic benefits of the 1998 tobacco settlement for Massachusetts.Tobacco industry ; Medical care, Cost of
The Economic Impacts of the Tobacco Settlement
Recent litigation against major tobacco companies culminated in a Master Settlement Agreement' (MSA) under which the participating companies agreed to compensate most states for Medicaid expenses. We outline the terms of the settlement and analyze whether it was a move toward economic efficiency using data from Massachusetts. Medicaid spending will fall, but only a modest amount ($0.1 billion). The efficiency issue turns mainly on the treatment of health benefits from reduced smoking induced by the settlement. We conclude that the settlement was a move towards economic efficiency.
The Price of Anarchy for Selfish Ring Routing is Two
We analyze the network congestion game with atomic players, asymmetric
strategies, and the maximum latency among all players as social cost. This
important social cost function is much less understood than the average
latency. We show that the price of anarchy is at most two, when the network is
a ring and the link latencies are linear. Our bound is tight. This is the first
sharp bound for the maximum latency objective.Comment: Full version of WINE 2012 paper, 24 page
Space and Ground Based Pulsation Data of Eta Bootis Explained with Stellar Models Including Turbulence
The space telescope MOST is now providing us with extremely accurate low
frequency p-mode oscillation data for the star Eta Boo. We demonstrate in this
paper that these data, when combined with ground based measurements of the high
frequency p-mode spectrum, can be reproduced with stellar models that include
the effects of turbulence in their outer layers. Without turbulence, the l=0
modes of our models deviate from either the ground based or the space data by
about 1.5-4.0 micro Hz. This discrepancy can be completely removed by including
turbulence in the models and we can exactly match 12 out of 13 MOST frequencies
that we identified as l=0 modes in addition to 13 out of 21 ground based
frequencies within their observational 2 sigma tolerances. The better agreement
between model frequencies and observed ones depends for the most part on the
turbulent kinetic energy which was taken from a 3D convection simulation for
the Sun.Comment: 13 pages, 7 figures, ApJ in pres
How Good a Deal Was the Tobacco Settlement?: Assessing Payments to Massachusetts
We estimate the increment in Massachusetts Medicaid program costs attributable to smoking from December 20, 1991, to 1998. We describe how our methods improve upon earlier estimates of analogous costs at the national level. Current costs to the Massachusetts Medicaid program approximate the payments to Massachusetts under the tobacco settlement of November 1998. Whether these payments are viewed as appropriate compensation for Medicaid costs over time depends upon the rate of increase in future health care costs, the rate of decline in smoking, the proportion of smoking that should be attributed to the actions of the tobacco companies and the liklihood that state would have prevailed at trial. The costs to the Medicaid program are dwarfed by the internal costs to smokers themselves.
Solar Oscillations and Convection: II. Excitation of Radial Oscillations
Solar p-mode oscillations are excited by the work of stochastic,
non-adiabatic, pressure fluctuations on the compressive modes. We evaluate the
expression for the radial mode excitation rate derived by Nordlund and Stein
(Paper I) using numerical simulations of near surface solar convection. We
first apply this expression to the three radial modes of the simulation and
obtain good agreement between the predicted excitation rate and the actual mode
damping rates as determined from their energies and the widths of their
resolved spectral profiles. We then apply this expression for the mode
excitation rate to the solar modes and obtain excellent agreement with the low
l damping rates determined from GOLF data. Excitation occurs close to the
surface, mainly in the intergranular lanes and near the boundaries of granules
(where turbulence and radiative cooling are large). The non-adiabatic pressure
fluctuations near the surface are produced by small instantaneous local
imbalances between the divergence of the radiative and convective fluxes near
the solar surface. Below the surface, the non-adiabatic pressure fluctuations
are produced primarily by turbulent pressure fluctuations (Reynolds stresses).
The frequency dependence of the mode excitation is due to effects of the mode
structure and the pressure fluctuation spectrum. Excitation is small at low
frequencies due to mode properties -- the mode compression decreases and the
mode mass increases at low frequency. Excitation is small at high frequencies
due to the pressure fluctuation spectrum -- pressure fluctuations become small
at high frequencies because they are due to convection which is a long time
scale phenomena compared to the dominant p-mode periods.Comment: Accepted for publication in ApJ (scheduled for Dec 10, 2000 issue).
17 pages, 27 figures, some with reduced resolution -- high resolution
versions available at http://www.astro.ku.dk/~aake/astro-ph/0008048
- …