Insuring Educational Risk: Opportunities versus Income

We develop a model of education where individuals face educational risk. Successfully entering the skilled labor sector depends on individual effort in education and public resources, but educational risk still causes (income) inequality. We show that an optimal public policy consists of deferred skill-specific tuition fees, lump-sum transfers/taxes, and public funding of the educational sector. We argue that improved educational opportunities matter more than direct income transfers in a Second-best setting. Contrary to standard models of income risk, it is not optimal to use a proportional wage tax, because combining skill-specific tuition fees and public education spending provide both insurance and redistribution at lower costs. A wage tax is only optimal if skill-specific tuition fees are not available.human capital investment, endogenous risk, learning effort, optimal taxation, public education

Educational and Wage Risk: Social Insurance vs. Quality of Education

In this model of education, where individuals are exposed both to educational risk and to wage risk within the skilled sector, successful graduation depends both on individual effort to study and on public resources. We show that insuring the present risks is a dichotomic task: Wage risk is diversified ex post among the skilled by graduate taxation and skill-specific tuition fees. Educational risk of failure and inequality between skilled and unskilled workers are mitigated ex ante by enhancing the quality of education. The necessary expenditures are optimally financed by regressive tuition fees and the net revenue from the graduate tax.human capital investment, educational risk, wage risk, learning effort, graduate taxation, regressive tuition fees

Microanalysis as ideology critique

Microanalysis – understood as the ‘zooming in’ on the details of everday social practices and situations – is an increasingly popular tool of academic study in the discipline of International Relations (IR) and beyond. However, the critical potential of so-called micro-moves is today largely ignored. This chapter seeks to revive this potential. It elaborates four different strategies for using microanalysis as a tool for criticizing theory as ideology

White Matter Structural Connectivity is Associated with Sensorimotor Function in Stroke Survivors

Purpose Diffusion tensor imaging (DTI) provides functionally relevant information about white matter structure. Local anatomical connectivity information combined with fractional anisotropy (FA) and mean diffusivity (MD) may predict functional outcomes in stroke survivors. Imaging methods for predicting functional outcomes in stroke survivors are not well established. This work uses DTI to objectively assess the effects of a stroke lesion on white matter structure and sensorimotor function. Methods A voxel-based approach is introduced to assess a stroke lesion\u27s global impact on motor function. Anatomical T1-weighted and diffusion tensor images of the brain were acquired for nineteen subjects (10 post-stroke and 9 age-matched controls). A manually selected volume of interest was used to alleviate the effects of stroke lesions on image registration. Images from all subjects were registered to the images of the control subject that was anatomically closest to Talairach space. Each subject\u27s transformed image was uniformly seeded for DTI tractography. Each seed was inversely transformed into the individual subject space, where DTI tractography was conducted and then the results were transformed back to the reference space. A voxel-wise connectivity matrix was constructed from the fibers, which was then used to calculate the number of directly and indirectly connected neighbors of each voxel. A novel voxel-wise indirect structural connectivity (VISC) index was computed as the average number of direct connections to a voxel\u27s indirect neighbors. Voxel-based analyses (VBA) were performed to compare VISC, FA, and MD for the detection of lesion-induced changes in sensorimotor function. For each voxel, a t-value was computed from the differences between each stroke brain and the 9 controls. A series of linear regressions was performed between Fugl-Meyer (FM) assessment scores of sensorimotor impairment and each DTI metric\u27s log number of voxels that differed from the control group. Results Correlation between the logarithm of the number of significant voxels in the ipsilesional hemisphere and total Fugl-Meyer score was moderate for MD (R2 = 0.512), and greater for VISC (R2 = 0.796) and FA (R2 = 0.674). The slopes of FA (p = 0.0036), VISC (p = 0.0005), and MD (p = 0.0199) versus the total FM score were significant. However, these correlations were driven by the upper extremity motor component of the FM score (VISC: R2 = 0.879) with little influence of the lower extremity motor component (FA: R2 = 0.177). Conclusion The results suggest that a voxel-wise metric based on DTI tractography can predict upper extremity sensorimotor function of stroke survivors, and that supraspinal intraconnectivity may have a less dominant role in lower extremity function

The Isle of Spice

https://digitalcommons.library.umaine.edu/mmb-ps/1676/thumbnail.jp

Looking left or looking right?

The perception of political messages may not only be shaped by textual information, but also by its visual appearance. An online experiment investigated how newspaper articles’ layout style and text slant affect the perception of a newspapers’ political orientation on the left-right axis. The layout versions were based on a prior analysis of correlations between design and political direction of quality newspapers. Results suggest the existence of political layout effects: a conservative layout style led to the source of a left-wing slanted text being estimated more right-wing, especially for left-wing-oriented participants. However, it had no effect when it was combined congruently with a right-wing slanted text. A progressive layout style had only an effect for participants with more knowledge on quality newspapers, leading them to locate the source more left-wing

Ram pressure and dusty red galaxies - key factors in the evolution of the multiple cluster system Abell 901/902

We present spectroscopic observations of 182 disk galaxies (96 in the cluster and 86 in the field environment) in the region of the Abell 901/902 multiple cluster system, which is located at a redshift of $z\sim 0.165$. The presence of substructures and non-Gaussian redshift distributions indicate that the cluster system is dynamically young and not in a virialized state. We find evidence for two important galaxy populations. \textit{Morphologically distorted galaxies} are probably subject to increased tidal interactions. They show pronounced rotation curve asymmetries at intermediate cluster-centric radii and low rest-frame peculiar velocities. \textit{Morphologically undistorted galaxies} show the strongest rotation curve asymmetries at high rest-frame velocities and low cluster-centric radii. Supposedly, this group is strongly affected by ram-pressure stripping due to interaction with the intra-cluster medium. Among the morphologically undistorted galaxies, dusty red galaxies have particularly strong rotation curve asymmetries, suggesting ram pressure is an important factor in these galaxies. Furthermore, dusty red galaxies on average have a bulge-to-total ratio higher by a factor of two than cluster blue cloud and field galaxies. The fraction of kinematically distorted galaxies is 75% higher in the cluster than in the field environment. This difference mainly stems from morphological undistorted galaxies, indicating a cluster-specific interaction process that only affects the gas kinematics but not the stellar morphology. Also the ratio between gas and stellar scale length is reduced for cluster galaxies compared to the field sample. Both findings could be best explained by ram-pressure effects.Comment: Electronic version published in Astronomy and Astrophysics Volume 549, Page 0; 19 pages, 21 figure

Tully-Fisher analysis of the multiple cluster system Abell 901/902

We derive rotation curves from optical emission lines of 182 disk galaxies (96 in the cluster and 86 in the field) in the region of Abell 901/902 located at $z\sim 0.165$. We focus on the analysis of B-band and stellar-mass Tully-Fisher relations. We examine possible environmental dependencies and differences between normal spirals and "dusty red" galaxies, i.e. disk galaxies that have red colors due to relatively low star formation rates. We find no significant differences between the best-fit TF slope of cluster and field galaxies. At fixed slope, the field population with high-quality rotation curves (57 objects) is brighter by \Delta M_{B}=-0\fm42\pm0\fm15 than the cluster population (55 objects). We show that this slight difference is at least in part an environmental effect. The scatter of the cluster TFR increases for galaxies closer to the core region, also indicating an environmental effect. Interestingly, dusty red galaxies become fainter towards the core at given rotation velocity (i.e. total mass). This indicates that the star formation in these galaxies is in the process of being quenched. The luminosities of normal spiral galaxies are slightly higher at fixed rotation velocity for smaller cluster-centric radii. Probably these galaxies are gas-rich (compared to the dusty red population) and the onset of ram-pressure stripping increases their star-formation rates. The results from the TF analysis are consistent with and complement our previous findings. Dusty red galaxies might be an intermediate stage in the transformation of infalling field spiral galaxies into cluster S0s, and this might explain the well-known increase of the S0 fraction in galaxy clusters with cosmic time.Comment: Accepted for publication in Astronomy and Astrophysics; 16 pages, 14 figure