A bounded jump for the bounded Turing degrees

We define the bounded jump of A by A^b = {x | Exists i <= x [phi_i (x) converges and Phi_x^[A|phi_i(x)](x) converges} and let A^[nb] denote the n-th bounded jump. We demonstrate several properties of the bounded jump, including that it is strictly increasing and order preserving on the bounded Turing (bT) degrees (also known as the weak truth-table degrees). We show that the bounded jump is related to the Ershov hierarchy. Indeed, for n > 1 we have X <=_[bT] 0^[nb] iff X is omega^n-c.e. iff X <=_1 0^[nb], extending the classical result that X <=_[bT] 0' iff X is omega-c.e. Finally, we prove that the analogue of Shoenfield inversion holds for the bounded jump on the bounded Turing degrees. That is, for every X such that 0^b <=_[bT] X <=_[bT] 0^[2b], there is a Y <=_[bT] 0^b such that Y^b =_[bT] X.Comment: 22 pages. Minor changes for publicatio

Growth and Diversity of the Population of the Soviet Union

The most remarkable feature of the Soviet Union's demography is its ethnic diversity. More than 90 ethnic groups are indigenous to the territory of the Soviet Union. Ethnic Russians composed only 50.8 percent of the population according to preliminary 1989 census results. The article examines official Soviet statistics for the period 1959 to 1989 to illustrate some of the risks in describing Soviet demographic behavior. Is fertility in the Soviet Union high or low? Answer: both. Is the Soviet population growing rapidly or slowly? Answer: both. The changing ethnic composition of the population of the USSR as a whole reflects large differences in growth rates of ethnic groups; the changing composition of the USSR by region also reflects differences in migration by ethnic group. Differences in growth rates are reshaping the ethnic composition of the Soviet labor force. For the USSR as a whole between 1979 and 1989, three-fourths of the net increment to the working ages was contributed by the one-sixth of the population in 1979 that was traditionally Muslim in religion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67141/2/10.1177_000271629051000112.pd

Vibrational properties of inclusion complexes: the case of indomethacin-cyclodextrin

Vibrational properties of inclusion complexes with cyclodextrins are studied by means of Raman spectroscopy and numerical simulation. In particular, Raman spectra of the non-steroidal, anti-inflammatory drug indomethacin undergo notable changes in the energy range between 1600 and 1700 cm$^{-1}$ when inclusion complexes with cyclodextrins are formed. By using both \emph{ab initio} quantum chemical calculations and molecular dynamics, we studied how to relate such changes to the geometry of the inclusion process, disentangling single-molecule effects, from changes in the solid state structure or dimerization processes.Comment: 14 file figure

Russia Faces Depopulation? Dynamics of Population Decline

Between 1992 and 1993 Russia's population declined, as it has in every succeeding year. This has been viewed as a population disaster, related to high adult male mortality and deterioration of the health care system. Some see a substantially depopulated Russia in the future. However, the prospect of long-term population decline is completely due to recent declines in fertility. High adult male mortality, although a cause of great concern, does not contribute to the chance of long-term population decline. Projections of the future population of Russia depend upon the exact fertility assumptions used. Based on the example of fertility in the United States in the Great Depression and the Baby Boom following World War II, the future depopulation of Russia is far from certain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43499/1/11111_2004_Article_369729.pd

Unintended Population Consequences of Policies

Unintended population consequences of policies stem from three sources: (1) A policy overshoots its original goal; (2) different policies conflict, so that the implementation of one policy inhibits implementation of another policy; (3) negative consequences of a policy are unforeseen, or are anticipated but judged unlikely to be severe or considered less important than the positive aims of the policy. Examples from Singapore, South Africa, Italy, the U.S., and the former Soviet Union are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43508/1/11111_2004_Article_489379.pd

Bounded low and high sets

Anderson and Csima (Notre Dame J Form Log 55(2):245–264, 2014) defined a jump operator, the bounded jump, with respect to bounded Turing (or weak truth table) reducibility. They showed that the bounded jump is closely related to the Ershov hierarchy and that it satisfies an analogue of Shoenfield jump inversion. We show that there are high bounded low sets and low bounded high sets. Thus, the information coded in the bounded jump is quite different from that of the standard jump. We also consider whether the analogue of the Jump Theorem holds for the bounded jump: do we have A ≤bT B if and only if Ab ≤1 Bb ? We show the forward direction holds but not the reverse

Energy Barriers to Motion of Flux Lines in Random Media

We propose algorithms for determining both lower and upper bounds for the energy barriers encountered by a flux line in moving through a two-dimensional random potential. Analytical arguments, supported by numerical simulations, suggest that these bounds scale with the length $t$ of the line as $t^{1/3}$ and $t^{1/3}\sqrt{\ln t}$, respectively. This provides the first confirmation of the hypothesis that barriers have the same scaling as the fluctuation in the free energy. \pacs{PACS numbers: 74.60.Ge, 05.70.Ln, 05.40.+j}Comment: 4 pages Revtex, 2 figures, to appear in PRL 75, 1170 (1995

Electrical anisotropy due to gas hydrate-filled fractures

In 2006, the Indian National Gas Hydrate Program Expedition 01, or NGHP-01, discovered gas hydrate as fill in near-vertical fractures in unconsolidated sediments at several drilling sites on the Indian continental margins. These gas hydrate-filled fractures were identified on logging-while-drilling resistivity images. The gas hydrate-filled fracture intervals coincide with high measured resistivity at the NGHP-01 sites. High measured resistivity translates into high hydrate saturations via Archie's equation; however, these high saturations contradict lower gas hydrate saturations determined from pressure core and chlorinity measurements. Also, in intervals with near-vertical gas hydrate-filled fractures, there is considerable separation between phase shift and attenuation resistivity logs, with 2-MHz resistivity measurements being significantly higher than 400-kHz resistivity measurements. We modeled the sensitivity of the propagation resistivity measurements in the gas hydrate-filled fracture intervals at NGHP-01 Sites 5 and 10. Near-vertical hydrate-filled fractures can cause the abnormally high resistivity measurements in vertical holes due to electrical anisotropy. The model suggests the gas hydrate saturations in situ are usually significantly lower than those calculated from Archie's equation. In addition, these modeled gas hydrate saturations generally agree with the lower gas hydrate saturations obtained from pressure core and chlorinity measurements at NGHP-01 Sites 5 and 10

Energy Barriers for Flux Lines in 3 Dimensions

I determine the scaling behavior of the free energy barriers encountered by a flux line in moving through a three-dimensional random potential. A combination of numerical simulations and analytic arguments suggest that these barriers scale with the length of the line in the same way as the fluctuation in the free energy.Comment: 12 pages Latex, 4 postscript figures tarred, compressed, uuencoded using `uufiles', coming with a separate fil