Campaign finance regulations and policy convergence: the role of interest groups and valence

Regulation of campaign finance of political parties and candidates is intended to decrease the political influence of special interest groups and enhance the public interest in electoral outcomes. I investigate empirically the consequences of campaign financing regulations and find that public funding leads parties' platforms to diverge whereas ceilings on individual contributions lead to platform convergence to the median voter outcome. I relate these consequences to differences in valence or intrinsic popularity of parties. I also show that platform divergence is associated with a ban on corporate donations and with requirements of public disclosure of parties' income statements.info:eu-repo/semantics/acceptedVersio

Lane reduction in driven 2d-colloidal systems through microchannels

The transport behavior of a system of gravitationally driven colloidal particles is investigated. The particle interactions are determined by the superparamagnetic behavior of the particles. They can thus be arranged in a crystalline order by application of an external magnetic field. Therefore the motion of the particles through a narrow channel occurs in well-defined lanes. The arrangement of the particles is perturbed by diffusion and the motion induced by gravity. Due to these combined influences a density gradient forms along the direction of motion of the particles. A reconfiguration of the crystal is observed leading to a reduction of the number of lanes. In the course of the lane reduction transition a local melting of the quasi-crystalline phase to a disordered phase and a subsequent crystallization along the motion of the particles is observed. This transition is characterized experimentally and using Brownian dynamics (BD) simulations.Comment: 4 pages, 4 figure

Disentangling the fiscal effects of local constitutions

We apply a regression discontinuity design to verify how constitutional rules, such aselectoral systems, shape budget revenues at the subnational governmental level. We takeadvantage of a natural experiment involving an institutional reform at the local level inPoland. The reform introduced two electoral rules, which changed according to an exogenouspopulation threshold: smaller municipalities used majoritarian elections and largermunicipalities used proportional elections. While intergovernmental grants increased inboth small and large municipalities, they increased less in municipalities with majoritarianelections compared to jurisdictions with proportional representation. This has furtherimplications regarding the level of property taxes and vertical fiscal imbalance. The jurisdictionswith proportional electoral systems had lower revenues from property taxes andhigher vertical fiscal imbalance than jurisdictions with majoritarian systems. We show thatthis effect works through the alignment channel, which is driven by the political alignmentof mayors with parties in the central government. This is more prevalent in proportionalelection scenarios. We also demonstrate that these effects are more pronounced in theperiod after 2002, when direct elections of mayors were introduced.Hervorming Sociale Regelgevin

Evidence for an Auditory Fovea in the New Zealand Kiwi (Apteryx mantelli)

Kiwi are rare and strictly protected birds of iconic status in New Zealand. Yet, perhaps due to their unusual, nocturnal lifestyle, surprisingly little is known about their behaviour or physiology. In the present study, we exploited known correlations between morphology and physiology in the avian inner ear and brainstem to predict the frequency range of best hearing in the North Island brown kiwi. The mechanosensitive hair bundles of the sensory hair cells in the basilar papilla showed the typical change from tall bundles with few stereovilli to short bundles with many stereovilli along the apical-to-basal tonotopic axis. In contrast to most birds, however, the change was considerably less in the basal half of the epithelium. Dendritic lengths in the brainstem nucleus laminaris also showed the typical change along the tonotopic axis. However, as in the basilar papilla, the change was much less pronounced in the presumed high-frequency regions. Together, these morphological data suggest a fovea-like overrepresentation of a narrow high-frequency band in kiwi. Based on known correlations of hair-cell microanatomy and physiological responses in other birds, a specific prediction for the frequency representation along the basilar papilla of the kiwi was derived. The predicted overrepresentation of approximately 4-6 kHz matches potentially salient frequency bands of kiwi vocalisations and may thus be an adaptation to a nocturnal lifestyle in which auditory communication plays a dominant role

Frequency-Invariant Representation of Interaural Time Differences in Mammals

Interaural time differences (ITDs) are the major cue for localizing low-frequency sounds. The activity of neuronal populations in the brainstem encodes ITDs with an exquisite temporal acuity of about . The response of single neurons, however, also changes with other stimulus properties like the spectral composition of sound. The influence of stimulus frequency is very different across neurons and thus it is unclear how ITDs are encoded independently of stimulus frequency by populations of neurons. Here we fitted a statistical model to single-cell rate responses of the dorsal nucleus of the lateral lemniscus. The model was used to evaluate the impact of single-cell response characteristics on the frequency-invariant mutual information between rate response and ITD. We found a rough correspondence between the measured cell characteristics and those predicted by computing mutual information. Furthermore, we studied two readout mechanisms, a linear classifier and a two-channel rate difference decoder. The latter turned out to be better suited to decode the population patterns obtained from the fitted model

Hyperspectral reflectance measurements from UAS under intermittent clouds: Correcting irradiance measurements for sensor tilt

One great advantage of optical hyperspectral remote sensing from unmanned aerial systems (UAS) compared to satellite missions is the possibility to fly and collect data below clouds. The most typical scenario is flying below intermittent clouds and under turbulent conditions, which causes tilting of the platform. This study aims to advance hyperspectral imaging from UAS in most weather conditions by addressing two challenges: (i) the radiometric and spectral calibrations of miniaturized hyperspectral sensors; and (ii) tilting effects on measured downwelling irradiance. We developed a novel method to correct the downwelling irradiance data for tilting effects. It uses a hybrid approach of minimizing measured irradiance variations for constant irradiance periods and spectral unmixing, to calculate the spectral diffuse irradiance fraction for all irradiance measurements within a flight. It only requires the platform's attitude data and a standard incoming light sensor. We demonstrated the method at the Palo Verde National Park wetlands in Costa Rica, a highly biodiverse area. Our results showed that the downwelling irradiance correction method reduced systematic shifts caused by a change in flight direction of the UAS, by 87% and achieving a deviation of 2.78% relative to a on ground reference in terms of broadband irradiance. High frequency (< 3 s) irradiance variations caused by high-frequency tilting movements of the UAS were reduced by up to 71%. Our complete spectral and radiometric calibration and irradiance correction can significantly remove typical striped illumination artifacts in the surface reflectance-factor map product. The possibility of collecting precise hyperspectral reflectance-factor data from UAS under varying cloud cover makes it more operational for environmental monitoring or precision agriculture applications, being an important step in advancing hyperspectral imaging from UAS.Innovation Fund Denmark/[7048-00001B]/IFD/DinamarcaAgricultural Water Innovations in the Tropics/[]/AgWIT/CanadáUniversidad de Costa Rica/[805-C0-603]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic

An unusual case of a microscopic alveolar adenoma coexisting with lung carcinoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Alveolar adenomas are extremely rare, benign, primary lung tumors of unknown histogenesis that are characterized by proliferative type II alveolar epithelium and septal mesenchyma. Mostly incidental, they are clinically important as they can imitate benign primary and secondary malignant tumors and at times are difficult to differentiate from early-stage lung cancer. We describe the case of a 59-year-old man with an incidental microscopic alveolar adenoma coexisting with poorly differentiated lung carcinoma.</p> <p>Case presentation</p> <p>A 59-year-old Caucasian man with a medical history of smoking and chronic obstructive pulmonary disease was incidentally found to have a right upper lobe mass while undergoing a computed tomographic chest scan as part of a chronic obstructive pulmonary disease clinical trial. Our patient underwent a right upper lobectomy after a bronchoscopic biopsy of the mass revealed the mass to be a carcinoma. A pathological examination revealed an incidental, small, 0.2 cm, well circumscribed lesion on the staple line margin of the lobectomy in addition to the carcinoma. Histopathological and immunohistochemical examinations revealed the lesion to be an alveolar adenoma.</p> <p>Conclusions</p> <p>We report the rare presentation of a microscopic alveolar adenoma coexisting with lung carcinoma. Alveolar adenoma is an entirely benign incidental neoplasm that can be precisely diagnosed using immunohistochemical analysis in addition to its unique histopathological characteristics.</p