Geographic variability in Calligrapha verrucosa (Suffrian 1858), a willow-feeding leaf beetle from western North America(Coleoptera: Chrysomelidae)

A diagnosis is provided to separate Calligrapha verrucosa (Suffrian) from similar species. Geographic variability is described and illustrated for various populations of C. verrucosa. A map is provided to indicate the distribution of this species

Relationship Between Fruit Yield and Damage by Codling Moth and Plum Curculio in a Biologically-Managed Apple Orchard

Fruit yield, codling moth (Cydia pomonella) damage, and plum curculio (Conotrachelus nenuphar) damage were monitored over an 8-year period in a O.5-ha, biologically-managed apple orchard in southwestern Michigan. The relationship between yield and damage was examined for both of these pests. The orchard showed clear biennial bearing patterns of alternating high and low yields. A significant negative correlation was found for yield and percent- age damage by codling moth but not for plum curculio damage. However, the estimated amount of fruit damaged by codling moth remained relatively stable over the period, indicating that changes in percentage damage depended on yield dynamics rather than changes in codling moth abundance. In contrast, the amount of fruit damaged by plum curculio showed biennial fluctuations and a positive correlation with yield, indicating that the population of this pest was capable of responding with increased oviposition in years with greater fruit yield. In addition, a comparison of codling moth fruit injury in years with and without the use of pheromone mating disruption showed no statistically significant reduction in damage as a result of using this method, suggesting that the orchard may be too small or codling moth populations too high for effective use of this management tactic

Analyzing the Data from X-ray Polarimeters with Stokes Parameters

X-ray polarimetry promises to deliver unique information about the geometry of the inner accretion flow of astrophysical black holes and the nature of matter and electromagnetism in and around neutron stars. In this paper, we discuss the possibility to use Stokes parameters - a commonly used tool in radio, infrared, and optical polarimetry - to analyze the data from X-ray polarimeters such as scattering polarimeters and photoelectric effect polarimeters, which measure the linear polarization of the detected X-rays. Based on the azimuthal scattering angle (in the case of a scattering polarimeter) or the azimuthal component of the angle of the electron ejection (in the case of a photoelectric effect polarimeter), the Stokes parameters can be calculated for each event recorded in the detector. Owing to the additive nature of Stokes parameters, the analysis reduces to adding the Stokes parameters of the individual events and subtracting the Stokes parameters characterizing the background (if present). The main strength of this kind of analysis is that the errors on the Stokes parameters can be computed easily and are well behaved - in stark contrast of the errors on the polarization fraction and polarization direction. We demonstrate the power of the Stokes analysis by deriving several useful formulae, e.g. the expected error on the polarization fraction and polarization direction for a detection of $N_S$ signal and $N_{BG}$ background events, the optimal observation times of the signal and background regions in the presence of non-negligible background contamination of the signal, and the minimum detectable polarization (MDP) that can be achieved when following this prescription.Comment: 9 pages, 2 figures, accepted for publication in Astropart. Phy

The Close Binary Fraction of Dwarf M Stars

We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template-fitting technique to measure radial velocities from 145,888 individual spectra obtained for a magnitude-limited sample of 39,543 M dwarfs. Typically, the three or four spectra observed for each star are separated in time by less than four hours, but for ~17% of the stars, the individual observations span more than two days. In these cases we are sensitive to large-amplitude radial velocity variations on timescales comparable to the separation between the observations. We use a control sample of objects having observations taken within a four-hour period to make an empirical estimate of the underlying radial velocity error distribution and simulate our detection efficiency for a wide range of binary star systems. We find the frequency of binaries among the dwarf M stars with a < 0.4 AU to be 3%-4%. Comparison with other samples of binary stars demonstrates that the close binary fraction, like the total binary fraction, is an increasing function of primary mass

On Properties of the Isoscalar Giant Dipole Resonance

Main properties (strength function, energy-dependent transition density, branching ratios for direct nucleon decay) of the isoscalar giant dipole resonance in several medium-heavy mass spherical nuclei are described within a continuum-RPA approach, taking into account the smearing effect. All model parameters used in the calculations are taken from independent data. Calculation results are compared with available experimental data.Comment: 12 pages, 2 figure

Made in America? The New World, the Old, and the Industrial Revolution

For two decades, the consensus explanation of the British Industrial Revolution has placed technological change and the supply side at center stage, affording little or no role for demand or overseas trade. Recently, alternative explanations have placed an emphasis on the importance of trade with New World colonies, and the expanded supply of raw cotton it provided. We test both hypotheses using calibrated general equilibrium models of the British economy and the rest of the world for 1760 and 1850. Neither claim is supported. Trade was vital for the progress of the industrial revolution; but it was trade with the rest of the world, not the American colonies, that allowed Britain to export its rapidly expanding textile output and achieve growth through extreme specialization in response to shifting comparative advantage.

Non-Fermi-Liquid Behavior from the Fermi-Liquid Approach

Non-Fermi liquid behavior of strongly correlated Fermi systems is derived within the Landau approach. We attribute this behavior to a phase transition associated with a rearrangement of the Landau state that leads to flattening of a portion of the single-particle spectrum $\epsilon({\bf p})$ in the vicinity of the Fermi surface. We demonstrate that the quasiparticle subsystem responsible for the flat spectrum possesses the same thermodynamic properties as a gas of localized spins. Theoretical results compare favorably with available experimental data. While departing radically from prevalent views on the origin of non-Fermi-liquid behavior, the theory advanced here is nevertheless a conservative one of in continuing to operate within the general framework of Landau theory.Comment: 8 pages, 4 figures, corrected list of author