Should Workers Care About Firm Size?

The question of wage differentials by firm size has been studied for several decades with no commonly accepted explanations for why large firms pay more. In this paper, we reexamine the relationship between firm size and wage outcomes by estimating the returns to unmeasured ability between large and small firms. Our empirical methodology, based on non- linear instrumental variable estimations, allows us to directly estimate the returns to unmeasured ability by firm size and, therefore, to test the two main theories of wage determination proposed to explain the relationship between firm size and wages, namely ability sorting and job screening. We use data from the Survey of Labour and Income Dynamics (SLID), which provides longitudinal information on workers' and firms' characteristics, including establishment and firm size. We find significant differences in the returns to unmeasured ability across firm size. In particular, we find that the returns to unmeasured ability seem to follow a non-linear pattern. The returns to unmeasured ability are significantly higher in medium size (above 500, but below 1000 workers) firms relative to small firms. However, the returns to unmeasured ability are not significantly greater in large firms relative to medium or small firms. Overall, it seems that ability sorting dominates for moves from small to medium size firms in that ability is more productive and, therefore, more rewarded in the latter than the former. On the other hand, when firms become "too large," the monitoring costs hypothesis seems to dominate in that ability is not more rewarded than in smaller firms.Firm Size, Comparative Advantage, Self-selection, Job Screening, Ability Sorting

Characterization of sex, age, and breed for a population of canine leishmaniosis diseased dogs.

Our study of a large canine population investigated whether the development of symptomatic canine leishmaniosis revealed any predilection for sex, age, or breed. Included in the study were 390 leishmaniosis-affected dogs that had been treated at the Hospital Clínic Veterinari attached to the Universitat Autònoma de Barcelona. Of the diseased dogs, 238 were male (61%) and 152 were females (39%), whereas percentages for males and females in the overall reference population of dogs treated at this unit were 53% and 47%, respectively, (P<0.05). Age distribution was bimodal, with the highest prevalence of the disease occurring at 2-4 years of age and a secondary peak occurring at seven years or over. The over represented breeds were the German shepherd (13.6% versus 6.35%, P<0.001), the Rottweiler (13.1% versus 3.0%, P<0.001), and the Boxer (7.9% versus 4.7%, P=0.002), whereas the underrepresented breeds were the Yorkshire terrier (0.5% versus 6.5%, P<0.001), and the Poodle (0.3% versus 3.0%, P<0.001)

Trinocular ystem for 3D motion and dense structure estimation

The relief of the seafloor is an important source of data for many scientists. In this paper we present an optical system to deal with underwater 3D reconstruction. This system is formed by three cameras that take images synchronously in a constant frame rate scheme. We use the images taken by these cameras to compute dense 3D reconstructions. We use Bundle Adjustment to estimate the motion of the trinocular rig. Given the path followed by the system, we get a dense map of the observed scene by registering the different dense local reconstructions in a unique and bigger one.Peer Reviewe

Of Mice and Men: Reflexiones sobre la ética de la experimentación animal

En el presente artículo se sostiene que la experimentación con animales es necesaria para generar una parte de los avances en los conocimientos médicos, pero sin ignorar el difícil e ineludible dilema moral que supone el imponer sufrimiento a unos seres a cambio de beneficios para otros que son, en esencia, muy similares a los primeros, tanto física como mentalmente. La similitud, cada vez más constatada por la ciencia, es rechazada por muchas personas para no tener mala conciencia por los numerosos usos y abusos que se hacen de los animales en la sociedad. Este rechazo encuentra reflejo en el ámbito legal y en el religioso, en los que se ha consolidado la equiparación de los animales a las cosas. Pero tal equiparación se revela cada vez menos plausible, y el trato hacia ellos dispensado cada vez menos justificable, con las crecientes evidencias sobre los sentimientos y la capacidad de raciocinio de los animales. La experimentación médica con animales es un caso especial, no obstante, por los importantes beneficios que reporta, que son reconocidos incluso por muchas personas preocupadas por la protección de los animales. Sin embargo, no pocos ciudadanos se manifiestan contrarios a estas prácticas al tiempo que desean beneficiarse de los avances médicos. Esta incoherente actitud puede deberse, por un lado, a que la sociedad no comprende la ciencia, y por otro al impacto de algunas campañas sensacionalistas en contra de la experimentación. Frente a todo esto, el autor plantea una serie de recomendaciones para el desarrollo de la actividad investigadora con animales basadas en la transparencia, la información, el reconocimiento del dilema ético y la participación en el debate que suscita, siempre con el objetivo de causar el menor sufrimiento posible.This essay argues that research on animals is necessary for the unhindered advancement of medical knowledge, but at the same time it recognises the moral dilemma of inflicting suffering on some beings for the benefit of others who are, in essence, very similar to them physically and mentally. The likeness, for which there is increasing scientific evidence, is rejected by many in order not to have bad conscience over the extensive use and abuse of animals in society. Such deeply rooted denial has been woven into most legal and religious traditions, which regard animals as things. This conception of animals is becoming increasingly implausible, and our poor treatment of them decreasingly justifiable, in the light of the amounting evidence regarding the existence and nature of their feelings and rationality. Medical research is a special case, however, because of the important benefits it provides, which many animal advocates are ready to admit. Nevertheless, a portion of society is against medical research on animals while still wanting to benefit from the medical advances. Such inconsistent attitudes may be due, on one hand, to the fact that people generally do not understand science, and on the other, to the impact of campaigns that selectively use very graphic examples of experiments. In this context the author proposes a set of recommendations for carrying out medical research on animals emphasising transparency, openness, recognition of the moral dilemma and participation in the debate it gives rise to, always keeping sight on the goal of minimising suffering

Colecciones ex situ de planta viva para la conservación de la planta amenazada Silene hifacensis, Rouy ex Willk (Caryophyllaceae)

The establishment of seed orchards has allowed obtaining a great deal of germoplasm of Silene hifacensis, an endangered endemic Ibero-Balearic species. In four years, 3.958.531 seeds have been collected in our four seed orchards from a total of 570 plants/year per average, including all genetic variability from natural populations of this species in Alicante province (Illot of Mona, the Pessebret, Cova de les Cendres, Morro de Toix)

A solution for secure certified electronic mail using blockchain as a secure message board

[eng] The certified mail is a value-added service that is widely used in the paper world. However, the scientific community has not yet provided a solution for certified e-mail that has achieved widespread acceptance. This lack of a certified e-mail solution is not due to a lack of proposed approaches; because over the past 40 years, more than 100 protocols have been reported in journals and at conferences. The vast majority of these proposed protocols use a trusted third party (TTP) to achieve fairness. The few solutions without a TTP have not been successful due to their high computational and/or communication cost. Blockchain provides a new approach to develop the protocols without a TTP but without the prior drawbacks of the previous solutions without a TTP. Here, we present a new protocol for certified e-mail based on a blockchain without a conventional TTP that is integrated with the conventional e-mail infrastructure. The protocol is secure, efficient, and viable from a practical perspective

A fair contract signing protocol with blockchain support

[eng] Electronically signing contracts is fundamental for e-commerce transactions. The main property that contract signing protocols must achieve is fairness of the exchange. The solutions presented to date are divided into two major types: those that have a trusted third party (TTP) to achieve fairness and those that do not. In the literature, we find more than 40 published proposals, but none of these proposed protocols has become a recognized or de facto standard in the market. Blockchain has provided a new way to address classic problems such as double spending, as well as problems such as fairness. In this article, we present a protocol for contract signing based on blockchain. Our proposed protocol does not require a conventional TTP, and it does not present the disadvantages of solutions without a TTP (computational and/or communication cost). The protocol satisfies the necessary security requirements: fairness, timeliness and non-repudiation. We demonstrate the feasibility of the protocol with a cost analysis and a proof of concept implementation. In addition, we show how Ethereum can be integrated in our solution as an alternative platform to the use of Bitcoin. Finally, we show how our proposal improves previous solutions for contract signing based on blockchain in terms of cost, efficiency and security

Accelerated amyloid deposition, neurofibrillary degeneration and neuronal loss in double mutant APP/tau transgenic mice

Even though the idea that amyloid beta peptide accumulation is the primary event in the pathogenesis of Alzheimer's disease has become the leading hypothesis, the causal link between aberrant amyloid precursor protein processing and tau alterations in this type of dementia remains controversial. We further investigated the role of beta-amyloid production/deposition in tau pathology and neuronal cell death in the mouse brain by crossing Tg2576 and VLW lines expressing human mutant amyloid precursor protein and human mutant tau, respectively. The resulting double transgenic mice showed enhanced amyloid deposition accompanied by neurofibrillary degeneration and overt neuronal loss in selectively vulnerable brain limbic areas. These findings challenge the idea that tau pathology in Alzheimer's disease is merely a downstream effect of amyloid production/deposition and suggest that reciprocal interactions between beta-amyloid and tau alterations may take place in vivo

Teaching architectural design through creative practices

[EN] This article provides investigation details of teaching architectural design as a fundamental part of the architectural discipline. This line of research delves into learning about the most creative action of the architectural production process, design, taking into account that creativity must be complemented by disciplinary training that combines both theoretical knowledge and practical skills. Considering these observations, this text provides information about the experience accomplished by four teachers from the School of Architecture of the Universitat Politecnica de Valencia (ETSA-UPV) on the subject of Design Studio 1 for the first-year studies. The propaedeutic character of this subject shows additional difficulties given the complexity of introducing the students into the field of architectural design. The article begins with a description of the historical background of teaching architecture, contextualizing the object of study and also the different processes used as reference during the accomplishment of the teaching experience. The second section includes a description of basic methodology of the specific case of the first-year subject taught in the ETSA-UPV. It provides analysis of its evolution, detection of the problems and suggested variations of the learning method in order to improve the final results. The canonical teaching method is based on a linear process starting with the theory, followed by architectural analysis, finishing with project synthesis, which generates important doubts for the first-year students when implementing the theory in the project phase. Therefore, resuming the cycle of circular learning studied by David Kolb, several creative practices have been introduced into the subject, where the order of the stages depends on the particular characteristics of each individual and learning takes place by combining practices of perception and comprehension. Keeping in mind the main goal of the new teaching approach, the third part of the text includes a description of several activities. They are designed using a methodology capable to promote the transfer of knowledge between the analysis phase and the project phase. Creative practices are based on the learning by doing process, where reflection, conceptualization and experimentation are carried out with two basic tools: hand drawing and the three-dimensional model. With the practices and these two manual tools we seek a triple objective for students: to acquire a greater creative capacity, to develop spatial vision and to recognize how materiality affects the definition and perception of space. The methodology of the practices includes thinking with the hands, folding the space, inhabiting the space and building the space, and it is compared to the results obtained during the academic year 2017-2018. Finally, these results, together with the surveys completed by the students, lead to following conclusions: introducing creative activities in the first year of architectural design has shown a substantial improvement of the work carried out by students and has allowed settling the acquired theoretical knowledge. It helps to understand it not only as concepts that can be observed and analysed in reality, but also as tools of the creative process itself. On the one hand, the construction of models supports intuitive learning, allowing the students to directly recognize the consequences of their actions during the constructive process and its implications in the final result. On the other hand, the activities developed using hand drawing techniques confirm the value of the drawn plans as a tool to define the results and verify their correctness. Experiencing architecture with the hands implicitly involves a work of reflection through which the students are able to understand that space is the actual key element of the architectural project.Lizondo Sevilla, L.; Bosch Roig, L.; Ferrer Ribera, MC.; Alapont-Ramón, J. (2019). Teaching architectural design through creative practices. Journal of the Faculty of Architecture. 36(1):41-59. https://doi.org/10.4305/METU.JFA.2019.1.8S415936