R-process and alpha-elements in the Galactic disk: Kinematic correlations

Recent studies of elemental abundances in the Galactic halo and in the Galactic disk have underscored the possibility to kinematically separate different Galactic subcomponents. Correlations between the galactocentric rotation velocity and various element ratios were found, providing an important means to link different tracers of star formation and metal enrichment to the Galactic components of different origin (collapse vs. accretion). In the present work we determine stellar kinematics for a sample of 124 disk stars, which we derive from their orbits based on radial velocities and proper motions from the the literature. Our stars form a subsample of the Edvardsson et al. (1993) sample and we concentrate on three main tracers: (i) Europium as an r-process element is predominantly produced in Supernovae of type II. (ii) Likewise, alpha-elements, such as Ca, Si, Mg, are synthesised in SNe II, contrary to iron, which is being produced preferentially in SNe Ia. (iii) The s-process element Barium is a measure of the relative contribution of AGB stars to the Galaxy's enrichment history and has been shown to be an indicator for distinguishing between thin and thick disk stars. All such studies reveal, basically, that stars with low galactocentric rotational velocity tend to have high abundances of alpha-elements and Eu, but lower abundances of, e.g., Ba.Comment: 5 pages, 2 figures, Poster contribution to appear in "Planets To Cosmology: Essential Science In Hubble's Final Years", proceedings of the May 2004 STScI Symposium, M. Livio (ed.), (Cambridge University Press

The Impact of Olfactory Cues on Attention: The Case of Stroop Interference

This study explores the relationship between odor imagery, color associations, and visual attention through a Stroop-task based on common odor-color associations. This Stroop-task was designed using three fruits with odor-color associations: lime with green, strawberry with red, and lemon with yellow. Each possible word-color combination was lexically presented in the experimental trials. Three experiments were conducted that used the Stroop-task with different odors present. They suggest that odor imagery can affect visual attention, the inhibition of odor-color associations, and that odor imagery appears to be facilitated in the presence of a related odor

The Impact f Olfactory Cues on Attention: The Case of Reverse Stroop Interference

Ham and Koch (2019) found that an odorant could influence interference on a modified Stroop task. This study was conducted to examine the impact of olfactory cues on reverse Stroop interference. Across three experiments, participants completed a modified reverseStroop task in which they identified a word (strawberry, lime, lemon) in different color fonts (red, green, yellow). Although the words were fruit names instead of color names, each word had some degree of association with a particular color (e.g., lime and green). In Experiment 1, congruent and incongruent trials were presented without an odorant. No differences were found between congruent and incongruent trials (t(28) = .63, p \u3e .05; d = .12). Experiment 2 consisted of the same task; however, an orange odorant was added to the room. RTs were faster for congruent trials than incongruent trials (t(17) = 4.15, p \u3c .001; d = .98). Lavender odorant was used in Experiment 3 to test whether the RT differences in Experiment 2 were influenced by the presence of a related odorant or any odorant. No differences were found between conditions (t(27) = 1.89, p \u3e .05; d = .36). The results indicate that a task-related odorant can impact word identification in a modified Stroop task

Analog VLSI-Based Modeling of the Primate Oculomotor System

One way to understand a neurobiological system is by building a simulacrum that replicates its behavior in real time using similar constraints. Analog very large-scale integrated (VLSI) electronic circuit technology provides such an enabling technology. We here describe a neuromorphic system that is part of a long-term effort to understand the primate oculomotor system. It requires both fast sensory processing and fast motor control to interact with the world. A one-dimensional hardware model of the primate eye has been built that simulates the physical dynamics of the biological system. It is driven by two different analog VLSI chips, one mimicking cortical visual processing for target selection and tracking and another modeling brain stem circuits that drive the eye muscles. Our oculomotor plant demonstrates both smooth pursuit movements, driven by a retinal velocity error signal, and saccadic eye movements, controlled by retinal position error, and can reproduce several behavioral, stimulation, lesion, and adaptation experiments performed on primates

Cyclosporin A inhibits PGE2 release from vascular smooth muscle cells

The influence of the fungoid undecapeptide cyclosporin A (CyA) on PGE2 release from cultured rat aortic smooth muscle cells was investigated in this study. We found that CyA time and concentration dependently (ED50:500 ng/ml) inhibited PGE2 release from the cells. CyA attenuated both basal and PGE2 release evoked by angiotensin II (10(-10)-10(-6) M), arginine vasopressin (10(-10)-10(-6) M) and ionomycin (10(-9)-10(-6) M). CyA (1 microgram/ml) did not affect the conversion of exogenous arachidonic acid (1 microM) into PGE2. The inhibitory effect of CyA was neutralized by high concentrations of the calcium ionophore ionomycin (greater than 3 X 10(-6) M). Taken together our results indicate that CyA inhibits both basal and vasoconstrictor evoked PGE2 release from vascular smooth muscle by impairing the availability of free arachidonic acid rather than by inhibiting the conversion of arachidonic acid into PGE2

Self-Regulation through Goal Setting

Goals are an important source of motivation. But little is known about why and how people set them. We address these questions in a model based on two stylized facts from psychology and behavioral economics: i) Goals serve as reference points for performance. ii) Present-biased preferences create self-control problems. We show how goals permit self-regulation, but also that they are painful self-disciplining devices. Greater self-control problems therefore lead to stronger self-regulation through goals only up to a certain point. For severely present-biased preferences, the required goal for self-regulation is too painful and the individual rather gives up.goals, self-control, motivation, time inconsistency, psychology

Goals and Psychological Accounting

We model how people formulate and evaluate goals to overcome self-control problems. People often attempt to regulate their behavior by evaluating goal-related outcomes separately (in narrow psychological accounts) rather than jointly (in a broad account). To explain this evidence, our theory of endogenous narrow or broad psychological accounts combines insights from the literatures on goals and mental accounting with models of expectations-based reference-dependent preferences. By formulating goals the individual creates expectations that induce reference points for task outcomes. These goal-induced reference points make substandard performance psychologically painful and motivate the individual to stick to his goals. How strong the commitment to goals is depends on the type of psychological account. We provide conditions when it is optimal to evaluate goals in narrow accounts. The key intuition is that broad accounts make decisions or risks in different tasks substitutes and thereby create incentives to deviate from goals. Model extensions explore the robustness of our results to different timing assumptions and goal and account revision.quasi-hyperbolic discounting, reference-dependent preferences, loss aversion, self-control, mental accounting, goals

Clustering of Trading Activity in the DAX Index Options Market

Trades in DAX index options with identical maturities cluster around particular classes of strike prices. For example, options with strikes ending on 50 are less traded than options with strikes ending on 00. Clustering is higher when options with close strike prices are good substitutes. The degree of substitution between options with neighboring strikes depends on the strike price grid and options' characteristics. Using regression analysis we analyze the relation between clustering, grid size, and the options' characteristics. To our knowledge this paper is the first to explore how the grid size of strike prices affects options' trading volume.Clustering, Incidental Truncation, Index Options, Volume

Coordination under the Shadow of Career Concerns

To innovate, employees need to develop novel ideas and coordinate with each other to turn these ideas into better products and services. Work outcomes provide signals about employees' abilities to the labor market, and therefore career concerns arise. These can both be 'good' (enhancing incentives for effort in developing ideas) and 'bad' (preventing voluntary coordination). Our model shows how the firm designs its explicit incentive system and organizes work processes to take these conflicting forces into account. The comparative statics results suggest a link between the increased use of teams and recent changes in labor market returns to skills.career concerns, group incentives, knowledge work, reputation, teams