Orbital Frontal Cortex Projections to Secondary Motor Cortex Mediate Exploitation of Learned Rules.

Animals face the dilemma between exploiting known opportunities and exploring new ones, a decision-making process supported by cortical circuits. While different types of learning may bias exploration, the circumstances and the degree to which bias occurs is unclear. We used an instrumental lever press task in mice to examine whether learned rules generalize to exploratory situations and the cortical circuits involved. We first trained mice to press one lever for food and subsequently assessed how that learning influenced pressing of a second novel lever. Using outcome devaluation procedures we found that novel lever exploration was not dependent on the food value associated with the trained lever. Further, changes in the temporal uncertainty of when a lever press would produce food did not affect exploration. Instead, accrued experience with the instrumental contingency was strongly predictive of test lever pressing with a positive correlation between experience and trained lever exploitation, but not novel lever exploration. Chemogenetic attenuation of orbital frontal cortex (OFC) projection into secondary motor cortex (M2) biased novel lever exploration, suggesting that experience increases OFC-M2 dependent exploitation of learned associations but leaves exploration constant. Our data suggests exploitation and exploration are parallel decision-making systems that do not necessarily compete

Ko-produktive Stadtentwicklung? Steuerungsansätze und Steuerungsprobleme mit kreativen Wertschöpfungsprozessen

In den wissenschaftlichen Diskussionen über die Kulturalisierung der Ökonomie oder Kreativquartiere lässt sich erkennen, dass für raumgestaltende Prozesse die Eigenlogiken kreativer Unternehmen von grundlegender Bedeutung sind. Zur Gestaltung einer kreativen Stadt sind flexible und projektbasierte Konstellationen notwendig. Hierarchische Organisationsmodelle und formelle Instrumente der Stadtplanung verlieren in diesem Kontext an Bedeutung. Horizontale Steuerungsformen und vor allem ko-produktive Aktivitäten sind dafür geeignet. Wichtige Akteure sind dabei natürlich Stadtplanungsämter und städtische Wirtschaftsförderungsgesellschaften. Diese Akteure setzen in der Praxis die damit verbundenen Aufgabenjedoch nur selten in Beziehung zu der Frage nach adäquaten Formen der räumlichen Planung oder Steuerung. Anhand eines bedarfsorientierten Forschungsansatzes habe ich dieses Phänomen planungswissenschaftlich untersucht und dazu die Wertschöpfungsprozesse kreativer Kleinstunternehmen in der Stadt Hamburg als Beispiel genommen. Dabei zeigen sich vielfältige Formen betrieblicher Entwicklungspfade sowie zielgruppenorientierte Unterstützungsmaßnahmen der lokalen Institutionen der Stadtplanung und Wirtschaftsförderung. Der Artikel beschreibt Steuerungsansätze und -probleme mit kreativen Ökonomien von unterschiedlichen Akteuren der öffentlichen Hand hinsichtlich gesamtstädtischer Entwicklungsperspektiven. Möglichkeiten und Grenzen ko-produktiver Stadtentwicklung werden konkret am Beispiel der Stadt Hamburg skizziert. Der Artikel endet mit Handlungsvorschlägen für eine Qualifizierung planerischer Ko-Produktion und Übertragungsmöglichkeiten für andere Städte

Developmental sensory experience balances cortical excitation and inhibition.

Early in life, neural circuits are highly susceptible to outside influences. The organization of the primary auditory cortex (A1) in particular is governed by acoustic experience during the critical period, an epoch near the beginning of postnatal development throughout which cortical synapses and networks are especially plastic. This neonatal sensitivity to the pattern of sensory inputs is believed to be essential for constructing stable and adequately adapted representations of the auditory world and for the acquisition of language skills by children. One important principle of synaptic organization in mature brains is the balance between excitation and inhibition, which controls receptive field structure and spatiotemporal flow of neural activity, but it is unknown how and when this excitatory-inhibitory balance is initially established and calibrated. Here we use whole-cell recording to determine the processes underlying the development of synaptic receptive fields in rat A1. We find that, immediately after the onset of hearing, sensory-evoked excitatory and inhibitory responses are equally strong, although inhibition is less stimulus-selective and mismatched with excitation. However, during the third week of postnatal development, excitation and inhibition become highly correlated. Patterned sensory stimulation drives coordinated synaptic changes across receptive fields, rapidly improves excitatory-inhibitory coupling and prevents further exposure-induced modifications. Thus, the pace of cortical synaptic receptive field development is set by progressive, experience-dependent refinement of intracortical inhibition

How Do Firms Respond to Place-Based Tax Incentives?

In this paper, we evaluate the effects of payroll tax changes on firm behavior, by exploiting a unique policy setting in Norway, where a system of geographically differentiated payroll taxes was suddenly abolished due to an EU regulation. We find that firms are only partially able to shift the increased costs from higher payroll tax rates onto workers’ wages. Instead, firms respond to the tax increase primarily by reducing employment. The drop in employment following the tax reform is particularly pronounced in labor intensive firms—which experience a larger windfall loss due to the tax reform than non-labor intensive firms—and in multi-establishment firms—which respond to the payroll tax increase in part by reducing the number of establishments per firm. Overall, our findings point to liquidity effects whereby a sudden and largely unexpected payroll tax increase aggravates firms’ liquidity constraints, forcing them to cut employment to bring down costs

Lepton Polarization in Neutrino-Nucleon Interactions

We derive generic formulas for the polarization density matrix of leptons produced in neutrino and antineutrino collisions and briefly consider some important particular cases. Next we employ the general formalism in order to include the final lepton mass and spin into the popular model by Rein and Sehgal for single pion neutrinoproduction.Comment: Talk given at 10th International Workshop on High-Energy Spin Physics (SPIN 03), Dubna, Russia, 16-20 Sep 2003. 12 pages; extended version, typos remove

Analysis of GPS radio occultation data from the FORMOSAT-3/COSMIC and Metop/GRAS missions at CDAAC

This study investigates the noise level and mission-to-mission stability of Global Positioning System (GPS) radio occultation (RO) neutral atmospheric bending angle data at the UCAR COSMIC Data Analysis and Archive Center (CDAAC). Data are used from two independently developed RO instruments currently flying in orbit on the FORMOSAT-3/COSMIC (F3C) and Metop/GRAS (GNSS Receiver for Atmospheric Sounding) missions. The F3C 50 Hz RO data are post-processed with a single-difference excess atmospheric phase algorithm, and the Metop/GRAS 50 Hz closed loop and raw sampling (down-sampled from 1000 Hz to 50 Hz) data are processed with a zero-difference algorithm. The standard deviations of the F3C and Metop/GRAS bending angles from climatology between 60 and 80 km altitude from June–December 2009 are approximately 1.78 and 1.13 μrad, respectively. The F3C standard deviation reduces significantly to 1.44 μrad when single-difference processing uses GPS satellites on the same side of the spacecraft. The higher noise level for F3C bending angles can be explained by additional noise from the reference link phase data that are required with single-difference processing. The F3C and Metop/GRAS mean bending angles differences relative to climatology during the same six month period are statistically significant and have values of −0.05 and −0.02 μrad, respectively. A comparison of ~13 500 collocated F3C and Metop/GRAS bending angle profiles over this six month period shows a similar mean difference of ~0.02 ± 0.02 μrad between 30 and 60 km impact heights that is marginally significant. The observed mean difference between the F3C and Metop/GRAS bending angles of ~0.02–0.03 μrad is quite small and illustrates the high degree of re-produceability and mission independence of the GPS RO data at high altitudes. Collocated bending angles between two F3C satellites from early in the mission differ on average by up to 0.5% near the surface due to systematically lower signal-to-noise ratio for one of the satellites. Results from F3C and Metop/GRAS differences in the lower troposphere suggest the Metop/GRAS bending angles are negatively biased compared to F3C with a maximum of several percents near the surface in tropical regions. This bias is related to different tracking depths (deeper in F3C) and data gaps in Metop/GRAS which make it impossible to process the data from both missions in exactly the same way

Radon mitigation during the installation of the CUORE 0νββ0\nu\beta\beta decay detector

CUORE - the Cryogenic Underground Observatory for Rare Events - is an experiment searching for the neutrinoless double-beta ($0\nu\beta\beta$) decay of $^{130}$Te with an array of 988 TeO$_2$ crystals operated as bolometers at $\sim$10 mK in a large dilution refrigerator. With this detector, we aim for a $^{130}$Te $0\nu\beta\beta$ decay half-life sensitivity of $9\times10^{25}$ y with 5 y of live time, and a background index of $\lesssim 10^{-2}$ counts/keV/kg/y. Making an effort to maintain radiopurity by minimizing the bolometers' exposure to radon gas during their installation in the cryostat, we perform all operations inside a dedicated cleanroom environment with a controlled radon-reduced atmosphere. In this paper, we discuss the design and performance of the CUORE Radon Abatement System and cleanroom, as well as a system to monitor the radon level in real time.Comment: 10 pages, 6 figures, 1 tabl