Bug-Fixing and Code-Writing: The Private Provision of Open Source Software

Open source software (OSS) is a public good. A self-interested individual would consider providing such software, if the benefits he gained from having it justified the cost of programming. Nevertheless each agent is tempted to free ride and wait for others to develop the software instead. This problem is modelled as a war of attrition with complete information, job signaling, repeated contribution to the public good and uncertainty in programming. The resulting game does not feature any delay: software will be provided swiftly, by young, low-cost individuals who gain considerably by signaling their programming skills; the startup (and collapse) of an OSS project displays bandwagon dynamics.open source software, war of attrition, public goods

On the timing between terrestrial gamma ray flashes, radio atmospherics, and optical lightning emission

On 25 October 2012 the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) and the Tropical Rainfall Measuring Mission (TRMM) satellites passed over a thunderstorm on the coast of Sri Lanka. RHESSI observed a terrestrial gamma ray flash (TGF) originating from this thunderstorm. Optical measurements of the causative lightning stroke were made by the lightning imaging sensor (LIS) on board TRMM. The World Wide Lightning Location Network (WWLLN) detected the very low frequency (VLF) radio emissions from the lightning stroke. The geolocation from WWLLN, which we also assume is the TGF source location, was in the convective core of the cloud. By using new information about both RHESSI and LIS timing accuracy, we find that the peak in the TGF light curve occurs 230 $\mu$s before the WWLLN time. Analysis of the optical signal from LIS shows that within the uncertainties, we cannot conclude which comes first: the gamma emission or the optical emission. We have also applied the new information about the LIS timing on a previously published event by {\O}stgaard et al. (2012). Also for this event we are not able to conclude which signal comes first. More accurate instruments are needed in order to get the exact timing between the TGF and the optical signal

Sexualmedizin für Gynäkologen

Zusammenfassung: Die Sexualität der Frau ist ein Paradigma für das Zusammenwirken biologischer, psychologischer und sozialer Faktoren. Die wichtigsten Störungen sind Mangel an sexuellem Verlangen, Erregungsstörungen, Störungen des Orgasmus und Schmerzen bei sexueller Aktivität. Häufig kommen diese Störungen kombiniert vor. In den letzten Jahren hat sich das Wissen um die neurophysiologischen, neuroendokrinen, vasomotorischen Prozesse bei der sexuellen Reaktion enorm erweitert und zur Entwicklung neuer Medikamente geführt. Gleichzeitig haben sich die psychologischen und soziologischen Erkenntnisse entwickelt und gewandelt. Als oft erste Ansprechpartner müssen sich Gynäkologinnen und Gynäkologen kontinuierlich weiterbilden, gleichzeitig müssen sie ihre kommunikativen Fertigkeiten in diesem sensiblen Bereich schulen. Ärztliches Gespräch, Diagnostik und Therapie folgen dabei dem Modell einer biopsychosozialen Sexualmedizin, die biomedizinischen Fortschritt mit psychosozialen Interventionen verbindet, um Patientinnen bei der Entfaltung ihrer selbstbestimmten und selbstgewählten Sexualität zu helfe

Chronic Toxicity Testing In Mining Influenced Streams of West Virginia

Whole effluent toxicity (WET) tests have become a common tool in the evaluation of effluent for discharge acceptability. In this study, four years of toxicity data from 119 sampling locations were analyzed to determine relationships with ions and conductivity as indicators of toxicity. West Virginia Stream Condition Index (WVSCI) scores were also examined to evaluate correlations between stream scores, conductivity, and IC25 endpoints from toxicity results. Conductivity was not an indicator of toxicity in the range of conductivities tested. Streams dominated by mining effluent sometimes exhibited toxicity to Ceriodaphnia dubia; however, toxicity was not found to be related to ionic concentration in the range tested. Although mortality and reproductive impairment were often demonstrated in the mining effluent dominated streams, there were no relationships established between survival and reproductive endpoints and the ionic concentrations. Benthic macroinvertebrate communities in the streams sampled indicated some level of impairment. Only a weak relationship was demonstrated between habitat assessment scores and WVSCI scores. No apparent relationship between conductivity and WVSCI was observed

Intrinsic motivation in open source software development

This papers sheds light on the puzzling evidence that even though open source software (OSS) is a public good, it is developed for free by highly qualified, young and motivated individuals, and evolves at a rapid pace. We show that once OSS development is understood as the private provision of a public good, these features emerge quite naturally. We adapt a dynamic private-provision-of-public-goods model to reflect key aspects of the OSS phenomenon. In particular, instead of relying on extrinsic motives for programmers (e.g. signaling) the present model is driven by intrinsic motives of OSS programmers, such as user-programmers, play value or homo ludens payoff, and gift culture benefits. Such intrinsic motives feature extensively in the wider OSS literature and contribute new insights to the economic analysis. --open source software,public goods,homo ludens,war of attrition

The effects of transgenic soybeans and associated herbicide treatment upon soil-surface mesofauna

While the percentage of transgenic soybean varieties being planted in Iowa has increased greatly, little has been done to evaluate the ecological consequences of these new technologies. Investigators examined the possible effects of three of these transgenic varieties and their associated broad-spectrum herbicides on soil-surface mesofauna, specifically springtails