Data Snapshot: U.S. Population Growth Continues to Slow Due to Fewer Births and More Deaths

The U.S. population grew by just 2,020,000 or 0.62 percent between July 2017 and July 2018 according to recent Census Bureau estimates. This is the lowest population growth rate since 1937

Rural demographic change in the new century: slower growth, increased diversity

This brief examines rural demographic trends in the first decade of the twenty-first century using newly available data from the 2010 Census. The rural population grew by just 2.2 million between 2000 and 2010—a gain barely half as great as that during the 1990s. Population growth was particularly slow in farming and mining counties and sharply reduced in rural manufacturing counties. Rural population gains were largest in high-amenity counties and just beyond the metropolitan fringe. Diversity accelerated in rural America, with racial and ethnic minorities accounting for 83 percent of rural population growth between 2000 and 2010

The changing face of Chicago: Demographic trends in the 1990s

The population of the Chicago metropolitan area grew by 869,000 (11.6%) between 1990 and 2000, the largest decade of growth in 30 years. The gain of 112,000 in the City of Chicago was the first in more than 50 years. Overall, gains were greatest in the outer suburbs and smallest in the city. Much of this growth was fueled by immigration and natural increase, with Hispanics contributing disproportionately to both

The Changing Discourse of the Supreme Court

[Excerpt] “Academics, judges, and other commentators complain that, for the past few decades, the Justices on the Supreme Court have been increasingly writing opinions that are unreadable for most American citizens. Those critics complain that the opinions are too long and too complex, riddled with incomprehensible multi-part tests. They also attack the style of the opinions and assert that recent opinions are more likely to be written in a technocratic, rather than persuasive, style. There seems to be little consensus among the critics regarding why the Justices are writing opinions that are increasingly unreadable. Some attribute it to the increasing complexity of issues that the Court is considering. Others suggest that the shift could be attributable to the lack of trial court experience among Justices. Some also speculate that a greater reliance on law clerks might be fueling a shift. Regardless of the reason for the shift, if such a shift is truly occurring, it could have important repercussions, depending on how one views the purposes of the Supreme Court’s opinions and the audiences to whom they are directed. If, as some academics assert, Supreme Court opinions are directed, at least in part, toward the public and are designed, at least in part, to advise the public about legal rights and responsibilities and to build public confidence in the rule of law by demonstrating a rational and transparent decision-making process, then unreadable Supreme Court opinions undermine those goals. If, however, Supreme Court opinions are simply directed to the parties before the court, other courts and agencies, lawyers, and law students, the shift is less problematic.

Microcystins in components of twelve New Hampshire lakes of varied trophic status

Cyanobacteria toxins, called microcystins (MCs), were found in components of twelve, stratified New Hampshire (USA) lakes of varied trophic status during the summer of 1998. A sensitive ELISA method detected MC levels in whole lakewater, grazable phytoplankton fractions (\u3c30 mm), net phytoplankton (\u3e 375 µm), and isolated copepod and cladoceran (Daphnia sp.) samples. Whole lakewater (WLW) and net phytoplankton MC concentrations ranged between 9 and 165 ng MC L-1 and 0.2 and 2031 mg MC g-1-dry wt, respectively. Lakewater MC concentrations correlated with total epilimnetic phosphorus and total epilimnetic chlorophyll a concentrations and inversely with Secchi disk depth. The filter-feeding cladoceran (daphnid) and omnivorous copepod components of the zooplankton were separated and assayed independently for MCs. The cladoceran component accumulated between 7 and 2800 µg MC g-1-dry wt. in 10 of the lakes. The copepod component accumulated similar levels (4 and 2400 µg MC g-1 dry-wt.) in all lakes. Toxin accumulation by zooplankton directly correlated with lakewater and net phytoplankton MC concentrations. The highest levels were found in Silver Lake, a productive lake where Microcystis aeruginosa blooms frequently occur. It is particularly noteworthy that MC levels were also detected by ELISA methods in Russell Pond, a pristine, deep mountain lake of low productivity. The results emphasize the importance of including oligotrophic lakes and water supplies in monitoring programs for MCs to ensure the safety of animals and humans utilizing them for drinking and recreation

Analytical shock solutions at large and small Prandtl number

Exact one-dimensional solutions to the equations of fluid dynamics are derived in the large-Pr and small-Pr limits (where Pr is the Prandtl number). The solutions are analogous to the Pr = 3/4 solution discovered by Becker and analytically capture the profile of shock fronts in ideal gases. The large-Pr solution is very similar to Becker's solution, differing only by a scale factor. The small-Pr solution is qualitatively different, with an embedded isothermal shock occurring above a critical Mach number. Solutions are derived for constant viscosity and conductivity as well as for the case in which conduction is provided by a radiation field. For a completely general density- and temperature-dependent viscosity and conductivity, the system of equations in all three limits can be reduced to quadrature. The maximum error in the analytical solutions when compared to a numerical integration of the finite-Pr equations is O(1/Pr) for large Pr and O(Pr) for small Pr.Comment: 11 pages, 6 figures. Accepted for publication in Journal of Fluid Mechanics Rapid