A Theory of Jurisdictional Assignments in Bureaucracies

What determines the allocation of tasks among government agencies? This article develops a formal model of task allocation that argues that jurisdictions are strategically designed to achieve legislative goals. In the model, agencies choose unobservable policies, and political outcomes are a noisy indicator of these choices. The legislature therefore faces a compliance issue when the agencies' policy preferences are different from its own. The legislature exerts control by defining agency jurisdictions, setting ex ante budgets and choosing ex post contractual inducements. The principal result is that tasks will be consolidated under a single roof when that agency prefers lower levels of policy than the legislature. In other cases, separating tasks prevents resources from being allocated in a manner undesirable for the legislature

Cascades of Dynamical Transitions in an Adaptive Population

In an adaptive population which models financial markets and distributed control, we consider how the dynamics depends on the diversity of the agents' initial preferences of strategies. When the diversity decreases, more agents tend to adapt their strategies together. This change in the environment results in dynamical transitions from vanishing to non-vanishing step sizes. When the diversity decreases further, we find a cascade of dynamical transitions for the different signal dimensions, supported by good agreement between simulations and theory. Besides, the signal of the largest step size at the steady state is likely to be the initial signal.Comment: 4 pages, 8 figure

An Informational Rationale for Political Parties

This article studies a model of political parties as informative "brands" to voters. Voters across a large number of constituencies are assumed to be risk averse and incompletely informed about candidate ideal policies, and candidates are unable to commit to a declared policy platform. In this environment, parties can play a critical role by aggregating ideologically similar candidates and signaling their preferences to voters. This signaling is effective because party membership imposes costs, which screen out candidates whose preferences are not sufficiently close to the party's platform. We find that when party labels are very informative, the parties' platforms converge. When party labels are less informative, however, platforms diverge, because taking an extreme position allows a party to reduce the variance of its members' preferences. As parties become less able to impose costs on their members, or less able to screen out certain types of candidates, their platforms move further apart

IFU observations of luminous type II AGN - I. Evidence for ubiquitous winds

We present observations of 17 luminous (log(L[O III]/L_Sun) > 8.7) local (z < 0.11) type II AGN. Our aim is to investigate the prevalence and nature of AGN driven outflows in these galaxies by combining kinematic and ionization diagnostic information. We use non-parametric methods (e.g. W80, the width containing 80% of the line flux) to assess the line widths in the central regions of our targets. The maximum values of W80 in each galaxy are in the range 400 - 1600 km/s, with a mean of 790 +- 90 km/s. Such high velocities are strongly suggestive that these AGN are driving ionized outflows. Multi-Gaussian fitting is used to decompose the velocity structure in our galaxies. 14/17 of our targets require 3 separate kinematic components in the ionized gas in their central regions. The broadest components of these fits have FWHM = 530 - 2520 km/s, with a mean value of 920 +- 50 km/s. By simultaneously fitting both the H{\beta}/[O III] and H{\alpha}/[N II] complexes we construct ionization diagnostic diagrams for each component. 13/17 of our galaxies show a significant (> 95 %) correlation between the [N II]/H{\alpha} ratio and the velocity dispersion of the gas. Such a correlation is the natural consequence of a contribution to the ionization from shock excitation and we argue that this demonstrates that the outflows from these AGN are directly impacting the surrounding ISM within the galaxies.Comment: 37 pages, 30 figures. Accepted for publication in MNRA

Timing and seasonality of the United States ‘warming hole’

The United States ‘warming hole’ is a region in the southeast/central U.S. where observed long-term surface temperature trends are insignificant or negative. We investigate the roles of anthropogenic forcing and internal variability on these trends by systematically examining observed seasonal temperature trends over all time periods of at least 10 years during 1901–2015. Long-term summer cooling in the north central U.S. beginning in the 1930s reflects the recovery from the anomalously warm ‘Dust Bowl’ of that decade. In the northeast and southern U.S., significant summertime cooling occurs from the early 1950s to the mid 1970s, which we partially attribute to increasing anthropogenic aerosol emissions (median fraction of the observed temperature trends explained is 0.69 and 0.17, respectively). In winter, the northeast and southern U.S. cool significantly from the early 1950s to the early 1990s, but we do not find evidence for a significant aerosol influence. Instead, long-term phase changes in the North Atlantic Oscillation contribute significantly to this cooling in both regions, while the Pacific Decadal Oscillation also contributes significantly to southern U.S. cooling. Rather than stemming from a single cause, the U.S. warming hole reflects both anthropogenic aerosol forcing and internal climate variability, but the dominant drivers vary by season, region, and time period

Synaptic Signaling by All-Trans Retinoic Acid in Homeostatic Synaptic Plasticity

SummaryNormal brain function requires that the overall synaptic activity in neural circuits be kept constant. Long-term alterations of neural activity lead to homeostatic regulation of synaptic strength by a process known as synaptic scaling. The molecular mechanisms underlying synaptic scaling are largely unknown. Here, we report that all-trans retinoic acid (RA), a well-known developmental morphogen, unexpectedly mediates synaptic scaling in response to activity blockade. We show that activity blockade increases RA synthesis in neurons and that acute RA treatment enhances synaptic transmission. The RA-induced increase in synaptic strength is occluded by activity blockade-induced synaptic scaling. Suppression of RA synthesis prevents synaptic scaling. This form of RA signaling operates via a translation-dependent but transcription-independent mechanism, causes an upregulation of postsynaptic glutamate receptor levels, and requires RARα receptors. Together, our data suggest that RA functions in homeostatic plasticity as a signaling molecule that increases synaptic strength by a protein synthesis-dependent mechanism

TESS Data Release Notes: Sector 18 DR25

This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 18 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics

TESS Data Release Notes: Sector 17, DR24

This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 17 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics