An analysis of imagery in listening to orchestral music in grades six and seven

Thesis (M.A.)--Boston Universit

Magnetoelastic Coupling and Possibility of Spintronic Electromagnetomechanical Effects

Nanoelectromangetomechanical systems (NEMMS) open up a new path for the development of high speed autonomous nanoresonators and signal generators that could be used as actuators, for information processing, as elements of quantum computers etc. Those NEMMS that include ferromagnetic layers could be controlled by the electric current due to effects related with spin transfer. In the present paper we discuss another situation when the current-controlled behaviour of nanorod that includes an antiferro- (instead of one of ferro-) magnetic layer. We argue that in this case ac spin-polarized current can also induce resonant coupled magneto-mechanical oscillations and produce an oscillating magnetization of antiferromagnetic (AFM) layer. These effects are caused by \emph{i}) spin-transfer torque exerted to AFM at the interface with nonmagnetic spacer and by \emph{ii}) the effective magnetic field produced by the spin-polarized free electrons due to $sd$-exchange.The described nanorod with an AFM layer can find an application in magnetometry and as a current-controlled high-frequency mechanical oscillator.Comment: 8 pages, 2 figures, submitted to Low Temp. Physic

Farming Exit Decision by Age Group: Analysis of Tobacco Buyout Impact in Kentucky

This article analyzes factors that affected the decision to exit tobacco production in the wake of the tobacco buyout program using the data collected through a survey of Kentucky tobacco farmers. Using the Heuristic logistic regression model, we find that the decision to exit tobacco growing was affected by efficiency considerations, availability of off-farm employment, and exit barriers. Availability of off-farm employment had the strongest effect on farmers younger than 46, while the effect of variables measuring efficiency and exit barriers seemed to be more uniform across age groups. Based on the results we suggest several policy interventions.age group, industry exit, tobacco buyout, tobacco farming, Agribusiness, Crop Production/Industries, Farm Management, Institutional and Behavioral Economics, Labor and Human Capital, Marketing, Production Economics, C25, D21, E24, J00, J11, J24, J43, Q18, R23,

Shape-induced phenomena in the finite size antiferromagnets

It is of common knowledge that the direction of easy axis in the finite-size ferromagnetic sample is controlled by its shape. In the present paper we show that a similar phenomenon should be observed in the compensated antiferromagnets with strong magnetoelastic coupling. Destressing energy which originates from the long-range magnetoelastic forces is analogous to demagnetization energy in ferromagnetic materials and is responsible for the formation of equilibrium domain structure and anisotropy of macroscopic magnetic properties. In particular, crystal shape may be a source of additional uniaxial magnetic anisotropy which removes degeneracy of antiferromagnetic vector or artificial 4th order anisotropy in the case of a square cross-section sample. In a special case of antiferromagnetic nanopillars shape-induced anisotropy can be substantially enhanced due to lattice mismatch with the substrate. These effects can be detected by the magnetic rotational torque and antiferromagnetic resonance measurements.Comment: 7 pages, 5 figures, to appear in Phys. Rev. B, v.75, N17, 200

Pathogen avoidance by insect predators

Insects can detect cues related to the risk of attack by their natural enemies. Pathogens are among the natural enemies of insects and entomopathogenic fungi attack a wide array of host species. Evidence documents that social insects in particular have adapted behavioural mechanisms to avoid infection by fungal pathogens. These mechanisms are referred to as 'behavioural resistance'. However, there is little evidence for similar adaptations in non-social insects. We have conducted experiments to assess the potential of common insect predators to detect and avoid their entomopathogenic fungal natural enemy Beauveria bassiana. The predatory bug Anthocoris nemorum was able to detect and avoid nettle leaves that were treated with B. bassiana. Females laid fewer eggs on leaf halves contaminated with the pathogen. Similarly, females were very reluctant to contact nettle leaves contaminated with the fungus compared to uncontaminated control leaves in ‘no-choice’ experiments. Adult seven spot ladybirds, Coccinella septempunctata, overwinter in the litter layer often in groups. Adult C. septempunctata modified their overwintering behaviour in relation to the presence of B. bassiana conidia in soil and sporulating conspecifics by moving away from sources of infection. Furthermore active (non-overwintering) adult C. septempunctata were also able to detect and avoid B. bassiana conidia on different substrates; bean leaves, soil and sporulating on dead conspecifics. Our studies show that insect predators have evolved mechanisms to detect and avoid pathogens that they are susceptible to. Fungal pathogens may be significant mortality factors among populations of insect predators, especially long-lived species that must diapause before reproduction. Likewise, actively foraging species are more likely to come in contact with pathogens than predators that sit and wait for prey. These particular groups of insects will benefit from adaptations to avoid pathogens

Domestic Violence: A Non-random Affair

In this paper, we develop and estimate a model of violence between romantically linked men and women. Physical violence is viewed as both a source of direct gratification and as an instrument for controlling the victim's behavior. Our model is a Stackleberg type model in which the assailant maximizes expected utility subject to the stochastic reaction function of the victim. Our model is estimated by a bounded-?influence regression technique because the process generating violence appears to lead to a heavy-tailed error distribution. Our empirical results suggest that increases in the assailants(i.e. the male's) income serve to increase violence, while increases in the proportion of the year that he is employed serve to decrease violence. Further, the employment effect is larger than the income effect. By way of contrast, our results suggest that the effect of a change in the female's employment or income depends heavily onher economic status relative to the male's. Finally, we find that improvements in the female's opportunites outside the relationship significantly reduce the level of violence.

Tax Compliance: An Investigation Using Individual TCMP Data

In this paper, we analyze the tax compliance behavior of US taxpayers by using a 1979 data set that combines information from a random sample of individual tax returns each of which has been thoroughly audited, IRS administrative records, and sociodemographic data from the Census. We find evidence that both audits and tax code provisions affect compliance. However, the effects are significant for only the low and high income groups. Interestingly, previous research has shown that these groups also participate most actively in underground economic activities, the income from which is not reported on any tax returns. Our results for audits suggest that the "ripple" or general deterrent effect of audits may be many times larger than the direct revenue yield of audits for high income taxpayers. Our results for allowable subtractions from income imply that the 1986 Tax Reform Act changes to lower allowable subtractions may have procompliance effects.