Collective Coordinate Action for Charged Sigma-Model Vortices in Finite Geometries

In this Letter the method of Lund is applied to formulate a variational principle for the motion of charged vortices in an effective non-linear Schr\"{o}dinger field theory describing finite size two-dimensional quantum Hall samples under the influence of an arbitrary perpendicular magnetic field. Freezing out variations in the modulus of the effective field yields a $U(1)$ sigma-model. A duality transformation on the sigma-model reduces the problem to finding the Green function for a related electrostatics problem. This duality illuminates the plasma analogy to the Laughlin wave function.Comment: 7 pp., Plain TeX (macros included), MAD/TH-92-0

A quantitative analysis of the phytoplankton of the Gulf of Panama II. On the relationship between C14 assimilation and the diatom standing crop

ENGLISH: The Inter-American Tropical Tuna Commission has maintained a hydro-biological station in the Gulf of Panama located at 8°45'N, 79°23'W in connection with their ecological investigation of the anchoveta (Cetengraulis mysticetus), a tuna baitfish (see Peterson, 1961, for references) . The depth is approximately 42 meters at mean low water at this station. Routine hydrographic and biological observations have been made (Schaefer, Bishop and Howard, 1958; Schaefer and Bishop, 1958; Forsbergh, 1963), including the collection of quantitative phytoplankton samples from November 1954 through May 1957 (Smayda, 1959; unpublished). The seasonal and regional variations in phytoplankton growth in the Gulf of Panama have also been investigated (Smayda, 1963). The relationships existing between C1 4 assimilation as determined by 24 hour in situ experiments and diatom standing crop at 10 meters when expressed as cell numbers, cell volume, cell surface area and cell plasma volume have been assessed for 30 observations made between November 1954 and May 1957 at 8°45'N, 79°23'W. The average cell volume and cell surface area characteristics for 110 diatom species and varieties are presented. SPANISH: Las relaciones existentes entre la asimilación del C14 , determinadas después de 24 horas de experimentos in situ, y la cosecha estable de las diatomeas a 10 metros, expresando el número de células, volumen celular, área de la superficie celular y volumen del plasma celular, han sido determinadas por medio de 30 observaciones hechas entre noviembre de 1954 y mayo de 1957, a los 8°45'N, 79°23'W. Se presenta, para 110 especies y variedades de diatomeas, el promedio de las características del volumen celular y del área de la superficie celular. (PDF contains 67 pages.

Statement of Theodore J. St. Antoine Before the Commission on the Future of Worker-Management Relations

Testimony_St_Antoine_040694.pdf: 205 downloads, before Oct. 1, 2020

Charged Vortex Dynamics in Ginzburg-Landau Theory of the Fractional Quantum Hall Effect

We write a Ginzburg-Landau Hamiltonian for a charged order parameter interacting with a background electromagnetic field in 2+1 dimensions. Using the method of Lund we derive a collective coordinate action for vortex defects in the order parameter and demonstrate that the vortices are charged. We examine the classical dynamics of the vortices and then quantize their motion, demonstrating that their peculiar classical motion is a result of the fact that the quantum motion takes place in the lowest Landau level. The classical and quantum motion in two dimensional regions with boundaries is also investigated. The quantum theory is not invariant under magnetic translations. Magnetic translations add total time derivative terms to the collective action, but no extra constants of the motion result.Comment: 28 pages + 1 Figure, new phyzzx macro (included), MAD/TH-92-0

Further Tests of Abortion and Crime: A Response to Donohue and Levitt (2001,2004, 2006)

The association between legalized abortion and crime remains a contentious finding with major implications for social policy. In this paper, I replicate analyses of Donohue and Levitt (2001, 2004, 2006) in which they regress age-specific arrests and homicides on cohort-specific abortion rates. I find that the coefficient on the abortion rate in a regression of age-specific homicide or arrest rates has either the wrong sign or is small in magnitude and statistically insignificant when adjusted for serial correlation. Efforts to instrument for measurement error are flawed and attempts to identify cohort from selection effects are mis-specified. Nor are their findings robust to alternative identification strategies. A convincing test of abortion and crime should be based on an exogenous change in abortion that had a demonstrable effect on fertility. Thus, I analyze changes in abortion rates before and after Roe to identify changes in unwanted fertility. I use within-state comparison groups to net out hard to measure period effects. I also follow Donohue and Levitt (2004) and average the effects of abortion on crime over 15 to 20 years of the life of a cohort to lessen the impact of the crack epidemic. I find little support for a credible association between legalized abortion and crime.

The Demand for Health Inputs and Their Impact on the Black Neonatal Mortality Rate in the U.S.

Relatively high birth rates among black adolescents and unmarried women as well as inadequate access to medical care are considered primary reasons why the black neonatal mortality rate is almost double that of whites. Using household production theory, this paper examines the determinants of input utilization and estimates the impact of utilization on the survival of black infants across large counties in the U.S. in 1977. The results indicate that expanding the availability of family planning clinics increases the number of teenagers served resulting in a lower neonatal mortality rate. Accessibility to abortion services operates in a similar manner. Moreover, the use of neonatal intensive care, which is strongly related to its availability, is an important determinant of newborn survivability whereas the initiation of early prenatal care is not. Overall, the results suggest that lowering the incidence of low weight and preterm births among blacks by helping women to avoid an unwanted birth, may be the moat cost-effective way of improving black infant health.