1,734 research outputs found
Redefining Utilities: Regulatory Change for Electric and Telephone Companies in Maine since 1980
The regulation of public utilities in Maine continues to evolve in response to changing economic, political and social forces. Not only has the structure of regulation of the electrical and telecommunications industry seen dramatic changes in the past 20 years, but it also is certain the next decade will see equally fundamental changes. Maine Policy Review invited three key participants in Maine\u27s regulatory arena to interpret the changes of the past two decades and what future changes we can expect. This article provides the perspectives of Public Advocate Steve Ward
Assessing Textbook Costs at a Small College
In recent years, the cost of textbooks has risen drastically, making it an important issue for everyone involved in higher education. Accurate and specific information on the cost of textbooks is needed to effectively address the situation. Over the summer of 2018, a librarian and an undergraduate student at a small liberal arts college assessed the textbook costs at their institution, using methodology developed by community colleges doing similar research. Based on course catalogs, bookstore records, and other resources, they calculated the costs for students in different disciplines over four years of study. These costs were impacted by major, courses chosen, and where materials were purchased. Patterns included higher prices in the sciences than in the humanities, as well as more expensive textbooks at the college bookstore than at other sources. Estimated total textbook costs varied widely (from under 7,000 for four years of study), leading the researchers to conclude that no single average was representative of any one student’s experience
Immunolocalization of Kinetodesmal Fibers with an Anti-Laminin Antibody in Tetrahymena thermophila
Netrin, a protein in the laminin family, is a pleiotropic signal that guides axonal development as well as angiogenesis in animals. Axonal guidance via netrins is dependent upon the ability of netrin to act both as a chemorepellent and a chemoattractant, depending upon the cell type and the netrin concentration. Tetrahymena thermophila are unicellular eukaryotic protists that can sometimes be used as a model system for neurons, due to the fact that both are excitable cells. Our previous studies have shown that netrin-1-peptide, netrin-3-peptides, and netrin-4 are all chemorepellents in Tetrahymena, and that netrin-like proteins may be isolated from Tetrahymena by Western blotting. Because netrins are part of the laminin family, we used immunofluorescence to investigate whether an anti-laminin antibody would bind to proteins in Tetrahymena. We hypothesized that an anti-laminin antibody should colocalize with an anti-netrin-1 antibody. Instead, we found that our anti-laminin antibody preferentially stained kinetodesmal fibers on the cell membrane, suggesting a structural role for a laminin-like protein in Tetrahymena
Evolution of Migrating Planets Undergoing Gas Accretion
We analyze the orbital and mass evolution of planets that undergo run-away
gas accretion by means of 2D and 3D hydrodynamic simulations. The disk torque
distribution per unit disk mass as a function of radius provides an important
diagnostic for the nature of the disk-planet interactions. We first consider
torque distributions for nonmigrating planets of fixed mass and show that there
is general agreement with the expectations of resonance theory. We then present
results of simulations for mass-gaining, migrating planets. For planets with an
initial mass of 5 Earth masses, which are embedded in disks with standard
parameters and which undergo run-away gas accretion to one Jupiter mass (Mjup),
the torque distributions per unit disk mass are largely unaffected by migration
and accretion for a given planet mass. The migration rates for these planets
are in agreement with the predictions of the standard theory for planet
migration (Type I and Type II migration). The planet mass growth occurs through
gas capture within the planet's Bondi radius at lower planet masses, the Hill
radius at intermediate planet masses, and through reduced accretion at higher
planet masses due to gap formation. During run-away mass growth, a planet
migrates inwards by only about 20% in radius before achieving a mass of ~1
Mjup. For the above models, we find no evidence of fast migration driven by
coorbital torques, known as Type III migration. We do find evidence of Type III
migration for a fixed mass planet of Saturn's mass that is immersed in a cold
and massive disk. In this case the planet migration is assumed to begin before
gap formation completes. The migration is understood through a model in which
the torque is due to an asymmetry in density between trapped gas on the leading
side of the planet and ambient gas on the trailing side of the planet.Comment: 26 pages, 29 figures. To appear in The Astrophysical Journal vol.684
(September 20, 2008 issue
Commentary: Energy Deregulation in Maine
Recent stories from California of power blackouts, utility bankruptcies, and skyrocketing rates have left many wondering whether Maine is going to suffer a similar fate. Like California, Maine has deregulated its electricity supply—an idea that sounded good to many, but which now has some questioning whether consumers will be made better off or worse. To address these issues, MPR asked six analysts to comment on electricity deregulation in Maine. Some address whether Maine is destined to follow in California’s footsteps. Others question whether regional decision making entities, such as the New England Power Pool and the Independent System Operator of New England, sufficiently represent the public interest. Still others address whether there is a future role for public conservation programs. Together, they suggest Maine will not befall the fate of California, but they also suggest that electricity deregulation in Maine may bring its own troubles if we’re not attentive and forward-thinking today
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