Specification of the Joy of Giving: Insights from Altruism

This paper analyzes the joy of giving bequest motive in which the utility obtained from leaving a bequest depends only on the size of the bequest. It exploits the fact that this formulation can be interpreted as a reduced form of an altruistic bequest motive to derive a relation between the value of the altruism parameter and the value of the joy of giving parameter. Using previous discussions of an a priori range of plausible values for the altruism parameter we then derive plausible restrictions on the joy of giving parameter. We demonstrate that this parameter may well be orders of magnitude larger than assumed in the existing literature.

Is music a language?:Adorno, Voloshinov, and the language character of music

Marxists regard works of art as meaningful, and look for political meanings even when they are not addressing political subjects. But where does music’s meaning lie? The conventional view is that music is non-referential, capable only of supporting other artforms or of expressing emotions. Adorno rejects the idea of music as a language of emotions, and does not believe that music has universal grammatical and syntactical rules. Yet he claims that music has language characteristics which make it as political as other artforms. What does he mean, and is he right? To answer those questions, we need to know how he understands language. This article examines how Adorno's view compares with the Marxist theory of language and consciousness developed by Valentin Voloshinov, and explores the extent to which approaching music from this direction might clarify a Marxist understanding of music and contribute to solving the thorny question of musical meaning

Dynamical Expansion of H II Regions from Ultracompact to Compact Sizes in Turbulent, Self-Gravitating Molecular Clouds

The nature of ultracompact H II regions (UCHRs) remains poorly determined. In particular, they are about an order of magnitude more common than would be expected if they formed around young massive stars and lasted for one dynamical time, around 10^4 yr. We here perform three-dimensional numerical simulations of the expansion of an H II region into self-gravitating, radiatively cooled gas, both with and without supersonic turbulent flows. In the laminar case, we find that H II region expansion in a collapsing core produces nearly spherical shells, even if the ionizing source is off-center in the core. This agrees with analytic models of blast waves in power-law media. In the turbulent case, we find that the H II region does not disrupt the central collapsing region, but rather sweeps up a shell of gas in which further collapse occurs. Although this does not constitute triggering, as the swept-up gas would eventually have collapsed anyway, it does expose the collapsing regions to ionizing radiation. We suggest that these regions of secondary collapse, which will not all themselves form massive stars, may form the bulk of observed UCHRs. As the larger shell will take over 10^5 years to complete its evolution, this could solve the timescale problem. Our suggestion is supported by the ubiquitous observation of more diffuse emission surrounding UCHRs.Comment: accepted to ApJ, 40 pages, 13 b/w figures, changes from v1 include analytic prediction of radio luminosity, better description of code testing, and many minor changes also in response to refere

Longitudinal assessment of reflexive and volitional saccades in Niemann-Pick Type C disease during treatment with miglustat

Peer reviewedPublisher PD

Specification of the Joy of Giving: Insights From Altruism

This paper analyzes the joy of giving bequest motive in which the utility obtained from leaving a bequest depends only on the size of the bequest. It exploits the fact that this formulation can be interpreted as a reduced form of an altruistic bequest motive to derive a relation between the value of the altruism parameter and the value of the joy of giving parameter. Using previous discussions of an a priori range of plausible values for the altruism parameter we then derive plausible restrictions on the joy of giving parameter. We demonstrate that this parameter may well be orders of magnitude larger than assumed in the existing literature

Determination of step rate thresholds corresponding to physical activity intensity classifications in adults

Journal ArticleBackground: Current recommendations call for adults to be physically active at moderate and/or vigorous intensities. Given the popularity of walking and running, the use of step rates may provide a practical and inexpensive means to evaluate ambulatory intensity. Thus, the purpose of this study was to identify step rate thresholds that correspond to various intensity classifications. Methods: Oxygen consumption was measured at rest and during 10 minute treadmill walking and running trials at 6 standardized speeds (54, 80, 107, 134, 161, and 188 m?min-1) in 9 men and 10 women (28.8 ? 6.8 yrs). Two observers counted the participants? steps at each treadmill speed. Linear and nonlinear regression analyses were used to develop prediction equations to ascertain step rate thresholds at various intensities. Results: Nonlinear regression analysis of the metabolic cost versus step rates across all treadmill speeds yielded the highest R2 values for men (R2 = .91) and women (R2 = .79). For men, the nonlinear analysis yielded 94 and 125 step?min-1 for moderate and vigorous intensities, respectively. For women, 99 and 135 step?min-1 corresponded with moderate and vigorous intensities, respectively. Conclusions: Promoting a step rate of 100 step?min-1 may serve as a practical public health recommendation to exercise at moderate intensity

Dwarf Galaxies with Ionizing Radiation Feedback. I: Escape of Ionizing Photons

We describe a new method for simulating ionizing radiation and supernova feedback in the analogues of low-redshift galactic disks. In this method, which we call star-forming molecular cloud (SFMC) particles, we use a ray-tracing technique to solve the radiative transfer equation for ultraviolet photons emitted by thousands of distinct particles on the fly. Joined with high numerical resolution of 3.8 pc, the realistic description of stellar feedback helps to self-regulate star formation. This new feedback scheme also enables us to study the escape of ionizing photons from star-forming clumps and from a galaxy, and to examine the evolving environment of star-forming gas clumps. By simulating a galactic disk in a halo of 2.3e11 Msun, we find that the average escape fraction from all radiating sources on the spiral arms (excluding the central 2.5 kpc) fluctuates between 0.08% and 5.9% during a ~20 Myr period with a mean value of 1.1%. The flux of escaped photons from these sources is not strongly beamed, but manifests a large opening angle of more than 60 degree from the galactic pole. Further, we investigate the escape fraction per SFMC particle, f_esc(i), and how it evolves as the particle ages. We discover that the average escape fraction f_esc is dominated by a small number of SFMC particles with high f_esc(i). On average, the escape fraction from a SFMC particle rises from 0.27% at its birth to 2.1% at the end of a particle lifetime, 6 Myrs. This is because SFMC particles drift away from the dense gas clumps in which they were born, and because the gas around the star-forming clumps is dispersed by ionizing radiation and supernova feedback. The framework established in this study brings deeper insight into the physics of photon escape fraction from an individual star-forming clump, and from a galactic disk.Comment: 15 pages, 12 figures, Accepted for publication in the Astrophysical Journal, Image resolution reduced, High-resolution version of this article is available at http://www.jihoonkim.org/index/research.html#sfm