Estimating development effort in free/open source software projects by mining software repositories: A case study of OpenStack

Because of the distributed and collaborative nature of free/open source software (FOSS) projects, the development effort invested in a project is usually unknown, even after the software has been released. However, this information is becoming of major interest, especially-but not only-because of the growth in the number of companies for which FOSS has become relevant for their business strategy. In this paper we present a novel approach to estimate effort by considering data from source code management repositories. We apply our model to the OpenStack project, a FOSS project with more than 1,000 authors, in which several tens of companies cooperate. Based on data from its repositories and together with the input from a survey answered by more than 100 developers, we show that the model offers a simple, but sound way of obtaining software development estimations with bounded margins of error.Gregorio Robles, Carlos Cervig on and Jes us M. Gonz alez-Barahona, project SobreSale (TIN2011-28110). and The work of Daniel Izquierdo has been funded in part by the Torres Quevedo program (PTQ-12-05577

Landscape Socioecology in the Serpis Valley (10,000–4000 BP)

En este trabajo se discute nuestro enfoque de la modelización del paisaje para la cuenca del Serpis medio (costa mediterránea central de la Península Ibérica) durante el Holoceno. La secuencia arqueológica de estos valles está marcada por la aparición inicial del paquete neolítico alrededor del año 5700 a.C. Examinamos cómo los paisajes responden al modo de vida agrícola, tanto a corto como a largo plazo. Conceptos como el cambio, la adaptación y también la resiliencia proporcionan marcos conceptuales para comprender mejor la forma en que los seres humanos interactúan con su entorno. También ayudan a explicar cómo fenómenos como la introducción inicial de la horticultura simple de cereales o la posterior introducción del cultivo del arado (Bernabeu Aubán 1995) pueden desencadenar procesos con consecuencias a veces impredecibles en los ecosistemas mediterráneos. Estas consecuencias no son inherentemente desastrosas, pero las interacciones entre los ecosistemas y los seres humanos que usan recursos son complejas y a menudo muestran resultados no lineales en sus respuestas a las actuaciones antrópicas. Utilizamos el concepto de socioecología para caracterizar estos sistemas humanos y naturales vinculados estrechamente, ya que estos deben ser un importante foco de interés para la arqueología.In this paper we discuss our approach to landscape modeling for the Holocene middle Serpis drainage system (central Mediterranean Coast of the Iberian Peninsula). The archaeological sequence of these valleys is marked by the initial appearance of the Neolithic package around 5700 BC. We examine how landscapes respond to the agricultural way of life, in both the short and the long term. Concepts like change, adaptation and also resilience provide conceptual frameworks to better understand the way in which humans interact with their surroundings. They also help to explain how phenomena like the initial introduction of simple cereal horticulture, or subsequent introduction of plow cultivation (Bernabeu Aubán 1995) can trigger processes with sometimes unpredictable consequences in Mediterranean ecosystems. These consequences are not inherently disastrous, but the interactions between ecosystems and humans using resources are complex and often display non-linear outcomes of human decisions. We use the concept of socioecology to characterize these closely coupled human and natural systems as these should be an important focus of interest for archaeology

Adicción a la pornografía: interferencia atencional y gravedad del consumo

Introduction: The increased use of Information and Comunication Tecnologies (ICT) and internet in our society has boosted new forms of addiction. Because of its public health concerns, one of the most important is cybersex addiction, and in particular excessive and problematic pornography consumption. Large number of studies pointed out that in some people, pornography viewing can be excessive and uncontrolled, creating several problems in different areas of life. For this reason, it is important to explore the underlying factors and maintainers in this problem. It is postulated that one of these factors could be the pornographic content ability to attract and consume attention resources (cue reactivity).The purpose of this study is to explore the relation between the attention interference created by the pornography contents viewing and severity of this behaviour. Method: To assess this attentional bias, we developed and applied an experimental task to a group of participants whose age oscillates between 18 and 35 years old. The experimental task was based on a Stroop task paradigm: participants concurrently answer to this attentional task when they were exposed to four types of contents (pornographic video, sitcom, video game and a low interactive content -a man reading a newspaper-). Participants received the premise of ignoring videos and focusing on answer quickly and accurately the Stroop task. Results: Level of attention interference created by pornography compared to other contents was assessed through the comparison between average reaction times and right answer and mistakes of each trial. These results, where we showed significant differences between the experimental conditions, will be exposed in detail during the presentation of the study.Conclusions: This study supports, on the one hand, the big ability of the different multimedia contents (among them, pornography), to attract and consume attentional resources; on the other hand, it also highlights the strong relation with the ability of attention interference that have their addictive potential. Therefore, it is important to include new clinical approaches that address this aspect at different levels: prevention, assessment, and treatment.Introducción: El aumento del uso de las Tecnologías de la Información y la Comunicación (TICS) e Internet en nuestra sociedad ha potenciado la aparición de nuevas formas de adicción. Una de las más relevantes por sus implicaciones sociosanitarias sería la adicción al cibersexo, y más en concreto, el visionado excesivo de pornografía online. Numerosos estudios apuntan que, en determinadas personas, el visionado de pornografía puede sobrevenir excesivo e incontrolado, generando graves problemas en las diferentes áreas de la vida. Por ello, es importante explorar aquellos factores que actúan como predisponentes o mantenedores de este problema. Se postula que uno de ellos podría ser la capacidad que tiene el material pornográfico para atraer y consumir recursos atencionales (cue reactivity), generando una interferencia en la atención a otros estímulos relevantes. Por tanto, el objetivo de este trabajo sería explorar la relación entre la interferencia atencional inducida por la exposición a contenidos pornográficos y la severidad de dicha conducta. Método: A fin de evaluar dichos sesgos atencionales, se desarrolló una tarea experimental que se aplicó a participantes con edades comprendidas entre los 18 y 35 años. La tarea experimental consistía en responder a una tarea Stroop al mismo tiempo que los participantes eran expuestos a cuatro tipos de video (pornográfico, serie de televisión, videojuego y contenido poco interactivo -un vídeo de un hombre leyendo el periódico-). Los participantes recibían la premisa de ignorar los videos y centrarse en responder de la forma más rápida y certera a la tarea Stroop. Resultados: El nivel de interferencia atencional inducida por la pornografía en comparación a la inducida por los otros tipos de contenidos se evalúo a través del contraste de los tiempos de reacción medios y los aciertos y errores de cada ensayo Stroop. Dichos resultados, donde se aprecian importantes diferencias entre las distintas condiciones experimentales, se exponen de forma detallada durante la presentación del presente trabajo. Conclusiones: Este estudio confirma la capacidad de distintos contenidos multimedia (entre ellos, la pornografía) para atraer y consumir recursos atencionales, así como la relación entre la capacidad de interferencia atencional y su potencial adictivo. Así, resulta primordial plantear nuevas aproximaciones clínicas que den relevancia a este aspecto tanto a nivel de evaluación como a nivel de tratamiento e intervención directa

Near-ground Effect of Height on Pollen Exposure

The effect of height on pollen concentration is not well documented and little is known about the near-ground vertical profile of airborne pollen. This is important as most measuring stations are on roofs, but patient exposure is at ground level. Our study used a big data approach to estimate the near-ground vertical profile of pollen concentrations based on a global study of paired stations located at different heights. We analyzed paired sampling stations located at different heights between 1.5 and 50m above ground level (AGL). This provided pollen data from 59 Hirst-type volumetric traps from 25 different areas, mainly in Europe, but also covering North America and Australia, resulting in about 2,000,000 daily pollen concentrations analyzed. The daily ratio of the amounts of pollen from different heights per location was used, and the values of the lower station were divided by the higher station. The lower station of paired traps recorded more pollen than the higher trap. However, while the effect of height on pollen concentration was clear, it was also limited (average ratio 1.3, range 0.7–2.2). The standard deviation of the pollen ratio was highly variable when the lower station was located close to the ground level (below 10m AGL). We show that pollen concentrations measured at >10m are representative for background near-ground levels