A General and Intuitive Envelope Theorem

We present an envelope theorem for establishing first-order conditions in decision problems involving continuous and discrete choices. Our theorem accommodates general dynamic programming problems, even with unbounded marginal utilities. And, unlike classical envelope theorems that focus only on differentiating value functions, we accommodate other endogenous functions such as default probabilities and interest rates. Our main technical ingredient is how we establish the differentiability of a function at a point: we sandwich the function between two differentiable functions from above and below. Our theory is widely applicable. In unsecured credit models, neither interest rates nor continuation values are globally differentiable. Nevertheless, we establish an Euler equation involving marginal prices and values. In adjustment cost models, we show that first-order conditions apply universally, even if optimal policies are not (S,s). Finally, we incorporate indivisible choices into a classic dynamic insurance analysis.

Biogeographic origin and radiation of the Old World crocidurine shrews (Mammalia: Soricidae) inferred from mitochondrial and nuclear genes.

The crocidurine shrews include the most speciose genus of mammals, Crocidura. The origin and evolution of their radiation is, however, poorly understood because of very scant fossil records and a rather conservative external morphology between species. Here, we use an alignment of 3560 base pairs of mitochondrial and nuclear DNA to generate a phylogenetic hypothesis for the evolution of Old World shrews of the subfamily Crocidurinae. These molecular data confirm the monophyly of the speciose African and Eurasian Crocidura, which also includes the fossorial, monotypic genus Diplomesodon. The phylogenetic reconstructions give further credit to a paraphyletic position of Suncus shrews, which are placed into at least two independent clades (one in Africa and sister to Sylvisorex and one in Eurasia), at the base of the Crocidura radiation. Therefore, we recommend restricting the genus Suncus to the Palaearctic and Oriental taxa, and to consider all the African Suncus as Sylvisorex. Using molecular dating and biogeographic reconstruction analyses, we suggest a Palaearctic-Oriental origin for Crocidura dating back to the Upper Miocene (6.8 million years ago) and several subsequent colonisations of the Afrotropical region by independent lineages of Crocidura.

Mutagenesis and modelling of the alpha(1b)-adrenergic receptor highlight the role of the helix 3/helix 6 interface in receptor activation.

Computer simulations on a new model of the alpha1b-adrenergic receptor based on the crystal structure of rhodopsin have been combined with experimental mutagenesis to investigate the role of residues in the cytosolic half of helix 6 in receptor activation. Our results support the hypothesis that a salt bridge between the highly conserved arginine (R143(3.50)) of the E/DRY motif of helix 3 and a conserved glutamate (E289(6.30)) on helix 6 constrains the alpha1b-AR in the inactive state. In fact, mutations of E289(6.30) that weakened the R143(3.50)-E289(6.30) interaction constitutively activated the receptor. The functional effect of mutating other amino acids on helix 6 (F286(6.27), A292(6.33), L296(6.37), V299(6.40,) V300(6.41), and F303(6.44)) correlates with the extent of their interaction with helix 3 and in particular with R143(3.50) of the E/DRY sequence.

Publiradio.net: innovación docente e investigación sobre publicidad radiofónica en el marco del EEES

La adaptación del sistema universitario catalán y español al Espacio Europeo de Educación Superior (EEES) está favoreciendo la aparición de nuevas metodologías docentes en respuesta a los requerimientos del llamado European Credit Transfer System (ECTS), una modalidad de crédito cuya principal característica consiste, como ya es ampliamente conocido, en focalizar la atención en el estudiante y, especialmente, en generar un proceso interactivo en el que el alumno se convierta en responsable activo de la adquisición de conocimientos. En el ámbito de las Ciencias de la Comunicación, una de las iniciativas más destacables de aproximación al EEES comienza en el año 2004, cuando el Departament d'Universitats, Investigació i Societat de la Informació de la Generalitat de Catalunya (DURSI) eligió a varios centros catalanes para que aplicaran de manera experimental el nuevo sistema común de créditos derivados de la Declaración de Bolonia. La Universidad Autónoma de Barcelona (UAB) fue uno de ellos, y ésta, a su vez, decidió poner en práctica la prueba piloto en la licenciatura de Publicidad y Relaciones Públicas. Es a partir de ese momento cuando los profesores del Departament de Comunicació Audiovisual i Publicitat de la UAB que forman el grupo de investigación Publiradio2 deciden poner en marcha un proyecto que, en el marco de las asignaturas de creatividad y de radio publicitaria, respondiera a las exigencias de la cultura docente en la que se inspira el crédito ECTS. Nace así Publiradio.net, un aplicativo on-line para la creación de publicidad radiofónica destinado, también, a facilitar y potenciar el aprendizaje autónomo entre los estudiantes, a fomentar, en sintonía con las apreciaciones de Aguaded, la utilización de 'técnicas y procedimientos que permitan al alumnado su análisis y uso como lenguajes propios' y a impulsar y facilitar a los estudiantes la investigación en publicidad radiofónica.

Control of schistosomiasis transmission

Despite the success of control programmes, schistosomiasis is still a serious public health problem in the world. More than 70 countries where 200 million individuals are evaluated to be infected of a total 600 million at risk. Though there have been important local success in the control of transmission, globally the infection has increased. Economic constrains in developing countries, environmental changes associated with migration and water resources development have been blocking the progress. The main objective of schistosomiasis control is to achieve reduction of disease due to schistosomiasis. We discussed the control measures like: health education, diagnosis and chemotherapy, safe water supplies, sanitation and snail control. We emphasized the need to give priority to school-age children and the importance of integrating the measures of control into locally available systems of health care. The control of schistosomiasis is directly related to the capacity of the preventive health services of an endemic country. The strategy of control requires long-term commitment from the international to the local level.

lntroducció de tècniques d'aprenentatge col·laboratiu en I'àmbit de bases de dades amb el suport de les tecnologies de la informació

Els canvi recents en els plans d’estudis de la UPC i la UOC tenen en compte el nou espai europeu d’educació superior (EEES). Una de les conseqüències directes a aquests canvis es la necessitat d'aprofitar i optimitzar el temps dedicat a les activitats d'aprenentatge que requereixen la participació activa de l’estudiant i que es realitzen de manera continuada durant el semestre. A més, I'EEES destaca la importància de les pràctiques, les relacions interpersonals i la capacitat per treballar en equip, suggerint la reducció de classes magistrals i l’augment d’activitats que fomentin tant el treball personal de l’estudiant com el cooperatiu. En l’àmbit de la docència informàtica d’assignatures de bases de dades el problema és especialment complex degut a que els enunciats de les proves no acostumen a tenir una solució única. Nosaltres hem desenvolupat una eina anomenada LEARN-SQL, l’objectiu de la qual és corregir automàticament qualsevol tipus de sentència SQL (consultes, actualitzacions, procediments emmagatzemats, disparadors, etc.) i discernir si la resposta aportada per l’estudiant és o no és correcta amb independència de la solució concreta que aquest proposi. D’aquesta manera potenciem l’autoaprenentatge i l’autoavaluació, fent possible la semi-presencialitat supervisada i facilitant l’aprenentatge individualitzat segons les necessitats de cada estudiant. Addicionalment, aquesta eina ajuda als professors a dissenyar les proves d’avaluació, permetent també la opció de revisar qualitativament les solucions aportades pels estudiants. Per últim, el sistema proporciona ajuda als estudiants per a que aprenguin dels seus propis errors, proporcionant retroalimentació de qualitat.

Adaptació del model europeu (EEES) de les assignatures relacionades amb organització i mètodes de treball de la Diplomatura de relacions Laborals

L'adaptació dels estudis a l'Espai Europeu d'Educació Superior (EEES) comporta l'establiment d'un nou paradigma docent centrat en l'estudiant, l'ús d'una nova unitat de valoració de l'activitat acadèmica, el crèdit europeu, i enfortir i repensar l'avaluació de l'aprenentatge. Aquesta adaptació representa una transformació profunda en el paper que juga tant el professor com l'alumne. En aquest context, es fa molt necessari adaptar les metodologies docents, els continguts i les eines d'interacció amb els alumnes. La finalitat d'aquest projecte consisteix en adaptar les assignatures troncals d'Organització i Mètodes de Treball de la Diplomatura de Relacions Laborals a aquest nou entorn. Per a tal fi, a part d'elaborar un pla docent consistent al EEES, també s'han de desenvolupar continguts, eines d'interacció i metodologies d'avaluació que permetin millorar el nivell de formació i el rendiment acadèmic de l'estudiant. Aquest projecte comprèn sis accions específiques per aconseguir-ho: 1) L'elaboració de la guia docent (objectius, capacitats a treballar, continguts, metodologia, avaluació, etc.); 2) L'elaboració del programa d'activitats (on es concreten les activitats d'aprenentatge que l'estudiant ha de dur a terme per assolir els objectius formatius: projectes tutoritzats, estudis de casos , lectures orientades, etc.) 3) Elaboració del material teòric. Aquesta acció té com a objectiu realitzar un llibre bàsic que comprengui la totalitat de la matèria relacionada amb OMT. 4) Elaboració del material pràctic. 5) Creació d'una pàgina web per aquest material. Aquesta web pretén ser un espai de treball comú pels estudiants de Relacions Laborals que cursin assignatures d'OMT a la UAB i la UPF. 6) Realitzar un projecte pilot tutoritzat. Aquesta prova pilot sorgeix arran de converses informals mantingudes amb alumnes de la diplomatura i la coordinadora d'estudis.

Application of a roughness-length representation to parameterize energy loss in 3-D numerical simulations of large rivers

Recent technological advances in remote sensing have enabled investigation of the morphodynamics and hydrodynamics of large rivers. However, measuring topography and flow in these very large rivers is time consuming and thus often constrains the spatial resolution and reach-length scales that can be monitored. Similar constraints exist for computational fluid dynamics (CFD) studies of large rivers, requiring maximization of mesh-or grid-cell dimensions and implying a reduction in the representation of bedform-roughness elements that are of the order of a model grid cell or less, even if they are represented in available topographic data. These ``subgrid'' elements must be parameterized, and this paper applies and considers the impact of roughness-length treatments that include the effect of bed roughness due to ``unmeasured'' topography. CFD predictions were found to be sensitive to the roughness-length specification. Model optimization was based on acoustic Doppler current profiler measurements and estimates of the water surface slope for a variety of roughness lengths. This proved difficult as the metrics used to assess optimal model performance diverged due to the effects of large bedforms that are not well parameterized in roughness-length treatments. However, the general spatial flow patterns are effectively predicted by the model. Changes in roughness length were shown to have a major impact upon flow routing at the channel scale. The results also indicate an absence of secondary flow circulation cells in the reached studied, and suggest simpler two-dimensional models may have great utility in the investigation of flow within large rivers. Citation: Sandbach, S. D. et al. (2012), Application of a roughness-length representation to parameterize energy loss in 3-D numerical simulations of large rivers, Water Resour. Res., 48, W12501, doi: 10.1029/2011WR011284.

The determinants of YIc's R&D activity

This paper examines the determinants of young innovative companies’ (YICs) R&D activities taking into account the autoregressive nature of innovation. Using a large longitudinal dataset comprising Spanish manufacturing firms over the period 1990-2008, we find that previous R&D experience is a fundamental determinant for mature and young firms, albeit to a smaller extent in the case of the YICs, suggesting that their innovation behaviour is less persistent and more erratic. Moreover, our results suggest that firm and market characteristics play a distinct role in boosting the innovation activity of firms of different age. In particular, while market concentration and the degree of product diversification are found to be important in boosting R&D activities in the sub-sample of mature firms only, YICs’ spending on R&D appears to be more sensitive to demand-pull variables, suggesting the presence of credit constraints. These results have been obtained using a recently proposed dynamic type-2 tobit estimator, which accounts for individual effects and efficiently handles the initial conditions problem.

Sistemes de crèdit hipotecari en l'europa del segle XIX, en especial a Catalunya i Espanya: legislació hipotecària i bancs hipotecaris

Investigación producida a partir de una estancia en la Westfälische Wilhelms-Universität, Alemania, entre julio y septiembre del 2007. En este trabajo, se estudia la situación del crédito hipotecario en España a mediados de siglo XIX (con especial atención a Cataluña). En su desarrollo, se abordan tres cuestiones. La situación del crédito hipotecario en España a mediados de siglo XIX. La legislación hipotecaria española en el siglo XIX. En especial, se ha puesto de relieve su incapacidad para movilizar la riqueza inmueble, que sólo se solucionó con una completa reforma hipotecaria y registral. El “sistema de crédito territorial” que, ideado por el desconocido abogado catalán Joaquín Borrell y Vilá, debe considerarse como el verdadero primer paso jurídico hacia el futuro desarrollo de las instituciones de crédito hipotecario en España, aunque fue ignorado por el Gobierno y los agentes económicos.

The ethnography of study abroad: what is study abroad as a cultural event?

Recent research in the field of study abroad shows that study abroad participation among all U.S. students increased 20% since 2001 and nearly 200,000 U.S. students currently go abroad each year. Additionally, about 8% of all undergraduate degree recipients receive part of their education abroad. Although quantitative studies have dominated research on study abroad, my research project calls for a qualitative approach since the goal is to understand what study abroad is as a cultural event, what authentic cultural immersion is, how program stakeholders understand and perceive cultural immersion, and how cultural immersion in programs can be improved. Following the tradition of ethnographic and case study approaches in study abroad research, my study also pivots on ethnography. As an ethnographer I collected data mainly through participant observation, semi-structured interviews, and document analysis. The study abroad participants were a group of undergraduate native speakers of English studying Spanish for seven weeks in Cádiz, a small costal city in southern Spain, as well as program coordinators, host community members, and professors. I also examined the specific program design features, particularly the in-class and out-of-class activities that students participated in. The goal was to understand if these features were conducive to authentic immersion in the language and culture. Eventually, I elaborated an ethnographic evaluation of the study abroad program and its design features suggesting improvements in order to enhance the significance and value of study abroad as a cultural event. Among other things, I discussed the difficulties that students had at the beginning of their sojourn to understand local people, get used to their host families’ small apartments, get adjusted to new schedules and eating habits, and venture out from the main group to individually explore the new social and cultural fabric and interact with the host community. The program evaluation revealed the need for carefully-designed pre-departure preparation sessions, pre-departure credit-bearing courses in intercultural communication, and additional language practice abroad and opportunities to come in contact with the local community through internships, volunteer or field work. My study gives an important contribution in study abroad research and education. It benefits students, teachers, and study abroad directors and coordinators in suggesting ideas on how to improve the program and optimize the students’ cultural experiences abroad. This study is also important because it investigated how US undergraduate learners studying the Spanish language and culture approach and perceive the study abroad experience in Spain.

Information systems for water resources management improvement in developing countries

Water resources management, as also water service provision projects in developing countries have difficulties to take adequate decisions due to scarce reliable information, and a lack of proper information managing. Some appropriate tools need to be developed in order to improve decision making to improve water management and access of the poorest, through the design of Decision Support Systems (DSS). On the one side, a DSS for developing co-operation projects on water access improvement has been developed. Such a tool has specific context constrains (structure of the system, software requirements) and needs (Logical Framework Approach monitoring, organizational-learning, accountability and evaluation) that shall be considered for its design. Key aspects for its successful implementation have appeared to be a participatory design of the system and support of the managerial positions at the inception phase. A case study in Tanzania was conducted, together with the Spanish NGO ONGAWA – Ingeniería para el Desarrollo. On the other side, DSS are required also to improve decision making on water management resources in order to achieve a sustainable development that not only improves the living conditions of the population in developing countries, but that also does not hinder opportunities of the poorest on those context. A DSS made to fulfil these requirements shall be using information from water resources modelling, as also on the environment and the social context. Through the research, a case study has been conducted in the Central Rift Valley of Ethiopia, an endhorreic basin 160 km south of Addis Ababa. There, water has been modelled using ArcSWAT, a physically based model which can assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time. Moreover, governance on water and environment as also the socioeconomic context have been studied.

Machine learning algorithms for spatial data. Case studies: Environmental pollution, natural hazards, renewable resources

This paper presents general problems and approaches for the spatial data analysis using machine learning algorithms. Machine learning is a very powerful approach to adaptive data analysis, modelling and visualisation. The key feature of the machine learning algorithms is that they learn from empirical data and can be used in cases when the modelled environmental phenomena are hidden, nonlinear, noisy and highly variable in space and in time. Most of the machines learning algorithms are universal and adaptive modelling tools developed to solve basic problems of learning from data: classification/pattern recognition, regression/mapping and probability density modelling. In the present report some of the widely used machine learning algorithms, namely artificial neural networks (ANN) of different architectures and Support Vector Machines (SVM), are adapted to the problems of the analysis and modelling of geo-spatial data. Machine learning algorithms have an important advantage over traditional models of spatial statistics when problems are considered in a high dimensional geo-feature spaces, when the dimension of space exceeds 5. Such features are usually generated, for example, from digital elevation models, remote sensing images, etc. An important extension of models concerns considering of real space constrains like geomorphology, networks, and other natural structures. Recent developments in semi-supervised learning can improve modelling of environmental phenomena taking into account on geo-manifolds. An important part of the study deals with the analysis of relevant variables and models' inputs. This problem is approached by using different feature selection/feature extraction nonlinear tools. To demonstrate the application of machine learning algorithms several interesting case studies are considered: digital soil mapping using SVM, automatic mapping of soil and water system pollution using ANN; natural hazards risk analysis (avalanches, landslides), assessments of renewable resources (wind fields) with SVM and ANN models, etc. The dimensionality of spaces considered varies from 2 to more than 30. Figures 1, 2, 3 demonstrate some results of the studies and their outputs. Finally, the results of environmental mapping are discussed and compared with traditional models of geostatistics.

Grámmata Kaì épos : Introducció a la literatura grega I

Aquest treball consisteix en la creació d'un crèdit variable adreçat a alumnat de 3r d'ESO. Hem de tenir en compte que aquest alumnat ja ha estat introduït prèviament a la cultura i civilització clàssica grega dins de l'àrea de ciències socials, per tant el que pretenem és endinsar-nos un poc més en aquesta temàtica, tot aprofundint en alguns aspectes sobre la seva literatura.

Three essays in international finance

Executive Summary The first essay of this dissertation investigates whether greater exchange rate uncertainty (i.e., variation over time in the exchange rate) fosters or depresses the foreign investment of multinational firms. In addition to the direct capital financing it supplies, foreign investment can be a source of valuable technology and know-how, which can have substantial positive effects on a host country's economic growth. Thus, it is critically important for policy makers and central bankers, among others, to understand how multinationals base their investment decisions on the characteristics of foreign exchange markets. In this essay, I first develop a theoretical framework to improve our knowledge regarding how the aggregate level of foreign investment responds to exchange rate uncertainty when an economy consists of many firms, each of which is making decisions. The analysis predicts a U-shaped effect of exchange rate uncertainty on the total level of foreign investment of the economy. That is, the effect is negative for low levels of uncertainty and positive for higher levels of uncertainty. This pattern emerges because the relationship between exchange rate volatility and 'the probability of investment is negative for firms with low productivity at home (i.e., firms that find it profitable to invest abroad) and the relationship is positive for firms with high productivity at home (i.e., firms that prefer exporting their product). This finding stands in sharp contrast to predictions in the existing literature that consider a single firm's decision to invest in a unique project. The main contribution of this research is to show that the aggregation over many firms produces a U-shaped pattern between exchange rate uncertainty and the probability of investment. Using data from industrialized countries for the period of 1982-2002, this essay offers a comprehensive empirical analysis that provides evidence in support of the theoretical prediction. In the second essay, I aim to explain the time variation in sovereign credit risk, which captures the risk that a government may be unable to repay its debt. The importance of correctly evaluating such a risk is illustrated by the central role of sovereign debt in previous international lending crises. In addition, sovereign debt is the largest asset class in emerging markets. In this essay, I provide a pricing formula for the evaluation of sovereign credit risk in which the decision to default on sovereign debt is made by the government. The pricing formula explains the variation across time in daily credit spreads - a widely used measure of credit risk - to a degree not offered by existing theoretical and empirical models. I use information on a country's stock market to compute the prevailing sovereign credit spread in that country. The pricing formula explains a substantial fraction of the time variation in daily credit spread changes for Brazil, Mexico, Peru, and Russia for the 1998-2008 period, particularly during the recent subprime crisis. I also show that when a government incentive to default is allowed to depend on current economic conditions, one can best explain the level of credit spreads, especially during the recent period of financial distress. In the third essay, I show that the risk of sovereign default abroad can produce adverse consequences for the U.S. equity market through a decrease in returns and an increase in volatility. The risk of sovereign default, which is no longer limited to emerging economies, has recently become a major concern for financial markets. While sovereign debt plays an increasing role in today's financial environment, the effects of sovereign credit risk on the U.S. financial markets have been largely ignored in the literature. In this essay, I develop a theoretical framework that explores how the risk of sovereign default abroad helps explain the level and the volatility of U.S. equity returns. The intuition for this effect is that negative economic shocks deteriorate the fiscal situation of foreign governments, thereby increasing the risk of a sovereign default that would trigger a local contraction in economic growth. The increased risk of an economic slowdown abroad amplifies the direct effect of these shocks on the level and the volatility of equity returns in the U.S. through two channels. The first channel involves a decrease in the future earnings of U.S. exporters resulting from unfavorable adjustments to the exchange rate. The second channel involves investors' incentives to rebalance their portfolios toward safer assets, which depresses U.S. equity prices. An empirical estimation of the model with monthly data for the 1994-2008 period provides evidence that the risk of sovereign default abroad generates a strong leverage effect during economic downturns, which helps to substantially explain the level and the volatility of U.S. equity returns.