741 research outputs found
Public Opinion in Perspective: Wisconsin's Mind on Education
Outlines survey findings on Wisconsin residents' views on the quality of public schools and reforms including increased spending, accountability, vouchers, charter schools, online education, and merit pay, compared with Milwaukee and national surveys
Donald Trump’s presidency will be a stress-test for American politics
Six weeks from now, Donald Trump will enter the White House as the 45th president of the United States. Ahead of Trump’s inauguration, William G. Howell poses three questions that he argues those who study American politics should be asking: does the political system require a base level of virtue after all; will the office of the presidency discipline Donald Trump; and what awaits the two major parties? Asking such questions will shed light on both Trump and the political institutions we thought we knew
Evaluation of Roadway Lighting Practices
Adequate roadway lighting allows better driver visibility during nighttime conditions. Research studies show that lighted roadways on average experience 28 percent fewer vehicles crashes on all roadway types. Most state DOTs have historically used High-Pressure Sodium (HPS) lights for their roadside lighting programs due to their wide availability and relatively low purchase costs. However, the short lifespan of HPS results in frequent replacement, leading to high life cycle costs. Light-Emitting Diode (LED) lights consume less energy, demonstrate improved performance, and require less overall maintenance due to their longer lifespans. Over time, this translates into maintenance cost savings for stateDOTs. In recent years, several state and local governments have begun increasing their use of LED lighting. KTC reviewed other state’s best practices for roadway lighting and assisted KYTC with analyzing the performance differences between HPS and LED. KTC also compiled a statewide roadside lighting inventory through coordination with each KYTC district.After developing the full inventory, the research team conducted light surveys at locations across Kentucky. The light surveys confirmed that LED lights routinely outperform HPS lights. It is recommended that Kentucky continue to transition to LED lighting, find a method for keeping the statewide lighting inventory up to date, and specify light spacing for new installations
The politician's province
Politicians, especially executives, regularly seek to project their influence into new policy domains. In some instances, they do so only after having secured the requisite statutory authority; in others, they intervene without prior authorization, hoping that their actions henceforth serve as precedent for future policy involvement. To investigate the conditions under which politicians pursue one strategy versus another, we study a stylized model of authority acquisition that recognizes the electoral pressures under which executives operate. We show that politicians seek authority that is both more secure and broader in scope as the public support for their policy position increases even if- indeed, precisely because|their opponent stands to benefit from this authority if elected to office. Far from tying their opponents' hands, as a number of literatures suggests, incumbents have electoral incentives to liberate them
Observations of Binary Stars with the Differential Speckle Survey Instrument. V. Toward an Empirical Metal-Poor Mass-Luminosity Relation
In an effort to better understand the details of the stellar structure and
evolution of metal poor stars, the Gemini North telescope was used on two
occasions to take speckle imaging data of a sample of known spectroscopic
binary stars and other nearby stars in order to search for and resolve close
companions. The observations were obtained using the Differential Speckle
Survey Instrument, which takes data in two filters simultaneously. The results
presented here are of 90 observations of 23 systems in which one or more
companions was detected, and 6 stars where no companion was detected to the
limit of the camera capabilities at Gemini. In the case of the binary and
multiple stars, these results are then further analyzed to make first orbit
determinations in five cases, and orbit refinements in four other cases. Mass
information is derived, and since the systems span a range in metallicity, a
study is presented that compares our results with the expected trend in total
mass as derived from the most recent Yale isochrones as a function of metal
abundance. These data suggest that metal-poor main-sequence stars are less
massive at a given color than their solar-metallicity analogues in a manner
consistent with that predicted from the theory
Observations of Binary Stars with the Differential Speckle Survey Instrument. VII. Measures from 2010 September to 2012 February at the WIYN Telescope
We report on speckle observations of binary stars carried out at the WIYN
Telescope over the period from September 2010 through February 2012, providing
relative astrometry for 2521 observations of 883 objects, 856 of which are
double stars and 27 of which are triples. The separations measured span a range
of 0.01 to 1.75 arc seconds. Wavelengths of 562 nm, 692 nm, and 880 nm were
used, and differential photometry at one or more of these wavelengths is
presented in most cases. Sixty-six components were resolved for the first time.
We also estimate detection limits at 0.2 and 1.0 arc seconds for high-quality
observations in cases where no companion was seen, a total of 176 additional
objects. Detection limits vary based on observing conditions and
signal-to-noise ratio, but are approximately 4 magnitudes at 0.2 arc seconds
and 6 magnitudes at 1.0 arc seconds on average. Analyzing the measurement
precision of the data set, we find that the individual separations obtained
have linear measurement uncertainties of approximately 2 mas, and photometry is
uncertain to approximately 0.1 magnitudes in general. This work provides
fundamental, well-calibrated data for future orbit and mass determinations, and
we present three first orbits and total mass estimates of nearby K-dwarf
systems as examples of this potential
Periodontal disease and risk of subsequent cardiovascular disease in U.S. male physicians
AbstractOBJECTIVESWe sought to prospectively assess whether self-reported periodontal disease is associated with subsequent risk of cardiovascular disease in a large population of male physicians.BACKGROUNDPeriodontal disease, the result of a complex interplay of bacterial infection and chronic inflammation, has been suggested to be a predictor of cardiovascular disease.METHODSPhysicians’ Health Study I was a randomized, double-blind, placebo-controlled trial of aspirin and beta-carotene in 22,071 U.S. male physicians. A total of 22,037 physicians provided self-reports of presence or absence of periodontal disease at study entry and were included in this analysis.RESULTSA total of 2,653 physicians reported a personal history of periodontal disease at baseline. During an average of 12.3 years of follow-up, there were 797 nonfatal myocardial infarctions, 631 nonfatal strokes and 614 cardiovascular deaths. Thus, for each end point, the study had >90% power to detect a clinically important increased risk of 50%. In Cox proportional hazards regression analysis adjusted for age and treatment assignment, physicians who reported periodontal disease at baseline had slightly elevated, but statistically nonsignificant, relative risks (RR) of nonfatal myocardial infarction, (RR, 1.12; 95% confidence interval [CI], 0.92 to 1.36), nonfatal stroke (RR, 1.10; CI, 0.88 to 1.37) and cardiovascular death (RR, 1.20; CI, 0.97 to 1.49). Relative risk for a combined end point of all important cardiovascular events (first occurrence of nonfatal myocardial infarction, nonfatal stroke or cardiovascular death) was 1.13 (CI, 0.99 to 1.28). After adjustment for other cardiovascular risk factors, RRs were all attenuated and nonsignificant.CONCLUSIONSThese prospective data suggest that self-reported periodontal disease is not an independent predictor of subsequent cardiovascular disease in middle-aged to elderly men
The Kepler Follow-up Observation Program
The Kepler Mission was launched on March 6, 2009 to perform a photometric
survey of more than 100,000 dwarf stars to search for terrestrial-size planets
with the transit technique. Follow-up observations of planetary candidates
identified by detection of transit-like events are needed both for
identification of astrophysical phenomena that mimic planetary transits and for
characterization of the true planets and planetary systems found by Kepler. We
have developed techniques and protocols for detection of false planetary
transits and are currently conducting observations on 177 Kepler targets that
have been selected for follow-up. A preliminary estimate indicates that between
24% and 62% of planetary candidates selected for follow-up will turn out to be
true planets.Comment: 12 pages, submitted to the Astrophysical Journal Letter
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