The Neronian Persecution

Let us for a moment pause here, and take a closer glimpse of Nero, who at this time occupied the throne at Rome. At the time of the fire he was in the tenth year of his reign

Against all odds: Tentative steps toward efficient information sharing in groups

When groups face difficult problems, the voices of experts may be lost in the noise of others’ contributions. We present results from a “naturally noisy” setting, a large first-year undergraduate class, in which the expert’s voice was “lost” to such a degree that bringing forward even more inferior information was optimal. A single individual had little chance to improve the outcome and coordinating with the whole group was impossible. In this setting, we examined the change in behavior before and after people could talk to their neighbors. We found that the number of people who reduced noise by holding back their information strongly and significantly increased

Sequential vs. Simultaneous Trust

We examine theoretically and experimentally the implications of trust arising under sequential and simultaneous designs, where one player makes an investment choice, and another player decides whether to share the investment gains. We show analytically that in some cases the sequential design may be outperformed by the simultaneous design. In an experiment we find that the investment levels and sharing rates are higher in the sequential design, but there are no corresponding differences in beliefs. We conjecture that this happens because in the sequential design substantially more trust is necessary to induce cooperation. Our data strongly support this conjecture

Behavioral and stimulant treatment of hyperactive children: a therapy study with methylphenidate probes in a within-subject design.

Eight hyperactive children were treated with a behavioral intervention focusing on teacher and parent training over a period of 5 months. Three times, before therapy and after 3 weeks and 13 weeks of intervention, children received methylphenidate during 3-week probe periods. Each week in a probe they received either a placebo, .25 mg/kg, or .75 mg/kg methylphenidate. Classroom observation of on-task behavior suggested that effectiveness of the behavioral intervention was between that of the two dosages of medication before therapy. Both dosages resulted in higher levels of on-task behavior when administered after 13 weeks of behavioral intervention than when administered before therapy. Teacher rating data showed equivalent effects of therapy and the low dosage of methylphenidate alone but a stronger effect of the high dose alone; only the high dose resulted in improved behavior after 13 weeks of behavioral intervention. As a group, only when they received the high dose of methylphenidate after 13 weeks of behavioral intervention did children reach the level of appropriate behavior shown by nonhyperactive controls. However, this level was also reached by two children with the low dose and by one child without medication, and it was not reached by one child. The results suggest that the combination of psychostimulant medication and behavior therapy may be more effective in the short-term than either treatment alone for hyperactive children in school settings. In addition, parent ratings and clinic observation of parent-child interactions suggested that children had improved in the home setting, high-lighting the importance of behavioral parent training in the treatment of hyperactivity

Likelihood Estimation for Censored Random Vectors

This article shows how to construct a likelihood for a general class of censoring problems. This likelihood is proven to be valid, i.e. its maximizer is consistent and the respective root-n estimator is asymptotically efficient and normally distributed under regularity conditions. The method generalizes ordinary maximum likelihood estimation as well as several standard estimators for censoring problems (e.g. tobit type I-tobit type V).Censored variables, Likelihood, Limited dependent variables, Multivariate methods, Random censoring,

Probing defect states in polycrystalline GaN grown on Si(111) by sub-bandgap laser-excited scanning tunneling spectroscopy

We demonstrate the potential of sub-bandgap laser-excited cross-sectional scanning tunneling microscopy and spectroscopy to investigate the presence of defect states in semiconductors. The characterization method is illustrated on GaN layers grown on Si(111) substrates without intentional buffer layers. According to high-resolution transmission electron microscopy and cathodoluminescence spectroscopy, the GaN layers consist of nanoscale wurtzite and zincblende crystallites with varying crystal orientations and hence contain high defect state densities. In order to discriminate between band-to-band excitation and defect state excitations, we use sub-bandgap laser excitation. We probe a clear increase in the tunnel current at positive sample voltages during sub-bandgap laser illumination for the GaN layer with high defect density, but no effect is found for high quality GaN epitaxial layers. This demonstrates the excitation of free charge carriers at defect states. Thus, sub-bandgap laser-excited scanning tunneling spectroscopy is a powerful complimentary characterization tool for defect states.INTRODUCTIO

Entwicklung eines Modellinstrumentariums zur immissionsseitigen Bewertung von Kfz-Emissionen. T. 1: Modell zur Wirkungsabschaetzung von verkehrsbezogenen Minderungsmassnahmen Endbericht

As a tool to facilitate the checking task of Paragraph 40.2 Federal Immission Control Act, the computer program CITAIR was developed. Its emission and transmission modules calculate air quality parameters for street canyons with high building density. Its measure module City IMPACT allows an a-priori assessment of the effects of traffic restrictions considering the given local frame conditions. Part 1 of the report describes the assessment model for transport related measures. Part 2 describes the transmission model IMMIS-Net/CPB for inert air pollutants. Part 3 describes a model system for 3-dimensional transmission in street canyons with special respect to photochemical reactions. (orig.)Als Hilfsmittel zur Umsetzung der Pruefaufgaben des Paragraph 40 Abs. 2 Bundes-Immissionsschutzgesetz wurde das Computerprogramm CITAIR fuer den Einsatz in Kommunal- und Landesbehoerden entwickelt. Mittels einer Emissions- und eines Ausbreitungsmoduls berechnet CITAIR die Immissionskonzentrationswerte an den Raendern einer Strassenschlucht mit dichter Randbebauung. Das Massnahmenmodul City IMPACT als drittes Element von CITAIR ermoeglicht die a-priori-Abschaetzung der Wirkungen von Verkehrsbeschraenkungen und Verkehrsverboten unter Beruecksichtigung der lokalen Randbedingungen. Berichtsteil 1 beschreibt das Modell zur Wirkungsabschaetzung von verkehrsplanerischen Massnahmen. Berichtsteil 2 beschreibt das Ausbreitungsmodul IMMIS-Net/CPB fuer inerte Schadstoffe. Berichtsteil 3 beschreibt ein Modellsystem zur dreidimensionalen Ausbreitungsrechnung unter Beruecksichtigung der Photochemie in Strassenschluchten. (orig.)SIGLEAvailable from TIB Hannover: F99B717 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekUmweltbundesamt, Berlin (Germany)DEGerman