Dynamic energy budget approach to evaluate antibiotic effects on biofilms

Quantifying the action of antibiotics on biofilms is essential to devise therapies against chronic infections. Biofilms are bacterial communities attached to moist surfaces, sheltered from external aggressions by a polymeric matrix. Coupling a dynamic energy budget based description of cell metabolism to surrounding concentration fields, we are able to approximate survival curves measured for different antibiotics. We reproduce numerically stratified distributions of cell types within the biofilm and introduce ways to incorporate different resistance mechanisms. Qualitative predictions follow that are in agreement with experimental observations, such as higher survival rates of cells close to the substratum when employing antibiotics targeting active cells or enhanced polymer production when antibiotics are administered. The current computational model enables validation and hypothesis testing when developing therapies.Comment: to appear in Communications in Nonlinear Science and Numerical Simulatio

Pharmaceutical M&A Activity: Effects on Prices, Innovation, and Competition

The rise of blockbuster pharmaceutical acquisitions has prompted fears that unprecedented market concentration will weaken competition. Two of the most prominent concerns focus on the upstream and downstream ends of the pharmaceutical industry: (1) the concern that these mergers will concentrate the market for discovery and will therefore lead to fewer discoveries; and (2) the concern that merging large marketing, sales, and distribution forces will strengthen the hands of select pharmaceutical manufacturers and weaken downstream competition. Having considered potential dynamic effects in the industry and conducted a series of preliminary interviews with knowledgeable observers, though, this Article argues that neither of these common fears is systematically warranted. There are, however, potential dangers in market concentration at an intermediate stage during the discovery-to-development path: the stage for regulatory approval. These preliminary findings are a product of dramatic changes that are currently reshaping the structure of the pharmaceutical industry. This Article discusses how these structural changes contribute to the current merger wave, how dynamic responses by industry players in response to the merger wave mitigate the potential harm from competition, and how the political arena might still offer threats to market concentration

The labour complementarity between international migration and national labour force in Spain, from a gender perspective

Comunicació presentada al 3rd European Workshop on "Labour Markets and Demographic Change". Organitzat pel Max Planck Institute for Demographic Research; Rostock Center for Research on Demographic Change; Department of Economics, University of Rostock. Rostock (Alemanya), 24 i 25 d'abril de 2008.Using the Spanish Labour Force Survey from 1999 to 2006, this article compares the distribution of foreign and national workers within the Spanish labour market. The initial hypothesis states that in the context of a segmented labour market, the recently arrived foreign population has filled the more precarious labour positions of the "secondary labour segment", allowing younger Spanish generations to occupy more skilled and stable occupations in accordance with educational attainment. This labour insertion has not only a national pattern but also a gendered one. Effectively, the increasing demand for immigrant women is a response to the improvement of the educational and socio-economic position of young female generations in Spain. We first carry out a descriptive analysis of the labour characteristics of the national and foreign population in Spain. In the second part of the analysis, using multivariable logistic regression models analysis, we attempt to establish that differentials in the labour attainment of nationals and foreigners are not only due to personal characteristics (educational levels, etc.) but also to gender and national identity.L'article compara, a través de les dades de la Encuesta de Población Activa (EPA) i, pel període 1999-2006, la distribució dels treballadors estrangers i nacionals en el mercat de treball espanyol. La hipòtesi inicial apunta que, en un mercat segmentat, els estrangers acabats d'arribar, ocupen les posicions més precàries del "segment de treball secundari", el que permet als joves espanyols ocupar aquelles posicions laborals més qualificades en relació al seu nivell d'instrucció. La inserció laboral no només segueix unes pautes diferenciades segons la nacionalitat, sinó també en funció del sexe. L'augment de la demanda de treballadors estrangers és una conseqüència de la millora educativa i de la posició socioeconòmica de les joves generacions femenines a Espanya. A la primera part de l'article, es desenvolupa un anàlisi descriptiu dels trets laborals de la població espanyola i estrangera. A la segona part, a partir de la tècnica de la regressió logística, es creen models multivariables per explicar com, les diferències entre les posicions laborals de nacionals i estrangers no venen només propiciades per les característiques dels treballadors (com el nivell d'instrucció), sinó també per diferències de gènere o per la nacionalitat dels mateixos.Este artículo compara, a través de los datos de la Encuesta de Población Activa (EPA) y para el periodo 1999-2006, la distribución de los trabajadores extranjeros y nacionales en el mercado de trabajo español. La hipótesis inicial apunta que, en un mercado segmentado, los extranjeros recién llegados ocupan las posiciones más precarias del "segmento de trabajo secundario" permitiendo a los jóvenes españoles ocupar aquellas posiciones laborales más cualificadas, en relación a su nivel educativo. Además, esta inserción laboral no solamente sigue unas pautas diferenciadas según la nacionalidad, sino también en función del sexo. Efectivamente, el aumento de la demanda de trabajadores extranjeros es una consecuencia de la mejora educativa y de la posición socio-económica de las jóvenes generaciones femeninas en España. En la primera parte del artículo, se desarrolla un análisis descriptivo de las características laborales de la población española y extranjera. En la segunda parte, a partir de la técnica de la regresión logística, se crean modelos multivariables para explicar cómo las diferencias entre las posiciones laborales de nacionales y extranjeros no son causadas solamente por características de los trabajadores (como el nivel de instrucción), sino también por diferencias de género o la nacionalidad de los mismos

Influència del flux a les propietats mecàniques del formigó convencional i reforçat amb fibres

Self compacting concrete is often defined as a composite that possesses not only a very high workability, which results in a not necessary compaction, but also that resists segregation and maintains stable composition throughout transport and placing. However, two of the inner properties of SCC, fluidity and stability, seem, in a primary analysis, to be opposed. That research has tried to investigate how these two properties interact. More particularly, what is the influence of the flow of concrete on its stability. However, this potential instability caused by flow could transcend further than the fresh state, affecting also the hardened properties. An initial experimental part had the aim to study the loss of uniformity caused by flow by means of the segregation experiment. Three mixes were studied, representing each mix one of the three groups: a self compacting concrete, a self compacting concrete with the aggregate grading modified for a potential higher segregation and, finally, a steel fibre reinforced self compacting concrete (SFRSCC). Almost identical results were assessed for the three mixes: the coarse aggregate distribution was constant along the length of the mould. In the case of the SFRSCC, also the fibre volume fraction exhibited a uniform distribution. Therefore, no segregation was observed for the three mixes studied, neither when the mix flowed into a 1,2 m long mould, nor when a longer mould of 2,96 m was used. The second part dealt with the distribution and orientation of fibres within SFRSCC elements. A uniform distribution of fibres is of crucial interest to guaranty the uniform response of the element and the absence of weaker sections that could cause structural problems. The results showed that no differences of the fibre orientation and distribution along the beam were caused by flow. Only a general tendency to distribute more fibres on the bottom part and to align in a planar orientation was observed. The final experimental part studied the potential influence of flow on the mechanical properties, more particularly, on the residual flexural strength of SFRSCC elements. The tested specimen, consisting of a 2,96 m long beam casted from one end, was sawn into three parts, so that three specimens composed of concrete with potentially different flow effects according to its proximity to the casting point were obtained. The mechanical properties of these specimens were studied through bending tests. After testing the thirds, the lack of differences on the flexural tensile strength between the third closer and the third further to the casting point proved that no influence of the flow of concrete was found in that mechanical property. The consideration of all the results obtained during the experimental research points in the direction that concrete had the enough stability during flow to exhibit uniform mechanical properties in the hardened state, unaffected by flow

Trade patterns of China and India

Artículo de revistaChina and India are playing an increasingly significant role in global trade. In 2016, their joint share of the global trade in goods reached around 14%, while their share of services came to 7.5%. They have very different trade profiles, however, also reflecting very different internationalisation strategies. Since opening up in the 1980s, China has taken on a global trade hub role, thanks to its growing integration into global production chains for manufactured goods. More recently, China has undergone a shift in trade specialisation towards a pattern characterised by the export of products with higher domestic value added (i.e. it has moved up the global value chain). India’s integration into global value chains has been much more limited and, since the early stages of its economic liberalisation, services have accounted for a substantial share of its exports. Although India’s export profile has remained fairly stable in recent decades, a growing weight of manufacturing exports with a greater import content has recently become discernible. Against this background, the estimation of goods export demand equations shows how, in the long run, external demand is the factor that wields most influence on developments in both countries’ exports, albeit more powerfully so in China, while price-competitiveness has a greater influence on Indian export

Modelo del proceso de diseño para el desarrollo de un Sistema Computacional de Asistencia al Diseño

Ponencia presentada en el VIII Congreso Internacional de Ingeniería de Proyectos celebrada en Bilbao en el año 2004One of the most interesting topics to enhance CAD systems consists of developing tools that further assist the designer during the conceptual phase. Those tools work in an interactive way. Two of the more broadly accepted computational models to assist design are: - The model proposed by Takeda and his colleagues, which models and makes use of different types of knowledge and reasoning, mainly the deductive and abductive reasoning types. - Chakrabarti’s model, in which a set of alternative solutions are synthesised to satisfy some initial functions of the problem, at the same time that they are used to check those functions. By doing so, co-evolution in the design process is achieved. With the aim to provide new insights into the development of computational tools that will further assist designers, an analysis of the most important characteristics of these models is done. As a result, the basis for a design process model, integrating Takeda’s and Chakrabarti’s models, is presented. The proposed model also includes the most recent experimental findings about the design process.Una de las líneas de interés en la mejora de los sistemas de Diseño Asistido por Ordenador (CAD) consiste en obtener herramientas que asistan en mayor medida al diseñador durante la fase de diseño conceptual, interactuando con éste. Dos de los modelos computacionales de asistencia al diseño que mayores avances están consiguiendo son: - El modelo computacional de Takeda y sus colaboradores, basado en el modelado y uso de diversos tipos de conocimiento y de razonamiento, principalmente el razonamiento deductivo y el abductivo; - El modelo basado en razonamiento funcional de Chakrabarti, en el que se parte de algunas de las funciones iniciales del problema, para las que se sintetiza un conjunto de alternativas, que son utilizadas a su vez para revisar las funciones, procediendo así de forma recursiva para conseguir la co-evolución del proceso de diseño. Con el fin de establecer nuevas propuestas para el desarrollo de herramientas computacionales que supongan una mayor asistencia al diseñador, se ha hecho un análisis de las características más importantes de estos modelos. Como resultado se presentan las bases de un modelo del proceso de diseño que fusiona los modelos desarrollados por Takeda y Chakrabarti y en el que también se consideran los resultados experimentales más recientes sobre el proceso de diseño

Labour insertion of immigrant women in the Spanish Labour Market

L’augment de la presència femenina entre la població immigrada a Espanya ha fet necessari replantejar-se’n l’estudi des de la perspectiva de gènere. En aquest treball, s’hi realitza un recorregut per les principals aportacions científiques centrades en la immigració femenina i, de manera més concreta, en la seva inserció en el mercat de treball espanyol. S’hi identifica la creixent demanda de treballadores per al servei domèstic com la raó principal de l’arribada de les dones no comunitàries, en el context de la internacionalització de les funcions de reproducció social. Ateses les diferències en els patrons d’activitat i en les posicions laborals que ocupen, existeix una complementarietat sociodemogràfica entre la mà d’obra femenina immigrada i l’autòctona. Les pàgines següents reuneixen, així mateix, els estudis principals sobre la mobilitat laboral de les treballadores immigrades, des del servei domèstic fins a unes altres activitats econòmiques.The increasing number of female immigrants in Spain made the introduction of the gender perspective in its analysis necessary. This paper quotes the main scientific contributions to the study of immigrant women and, more specifically, in their insertion in the Spanish Labour Market. Demand of female workers for the domestic service, is identified by most of the authors, as the most important cause of arrival of non-communitarian women. Therefore, it would be part of the internationalization of the social reproduction process. Differences between activity trends and labour positions indicate that there is socio-demographic complementarity between the immigrant and the native female labour force The next pages summarize the most notorious study on immigrant women’s labour mobility from domestic service to other activities.La creciente presencia femenina entre la población inmigrada en España ha hecho necesario replantearse el estudio de la misma desde una perspectiva de género. En el presente trabajo, se hace un recorrido por las principales aportaciones científicas centradas en la inmigración femenina y, de manera específica, en su inserción en el mercado de trabajo español. Se identifica la demanda creciente de trabajadoras para el servicio doméstico como la razón principal de la llegada de las mujeres no comunitarias, dentro de la internacionalización de las funciones de reproducción social. El resultado ha sido la existencia de la complementariedad sociodemográfica entre la mano de obra femenina inmigrada y la autóctona, dadas las diferencias en sus patrones de actividad y en las posiciones laborales que ocupan. Las siguientes páginas reúnen, asimismo, los principales estudios sobre la movilidad laboral, desde el servicio doméstico hacia otras actividades económicas de las trabajadoras inmigradas

Heuristic guidelines to support conceptual design

The creativity or unforeseeable nature of the design process, especially during the conceptual phase, makes it difficult to apply current design methodologies to aid designers and help them to reach a conceptual solution in an effective manner. In this paper we present some guidelines, based on experimental data about the evolution of the design process, with which to improve the effectiveness of the conceptual phase, above all as regards finding solutions. Here, effectiveness is taken as meaning quickly reaching a design solution that satisfies the requirements of the problem. Some of the guidelines obtained allow the effectiveness of a designer or a group of designers to be enhanced and are oriented towards controlling the divergence and convergence of the design space. Some guidelines for the development of interactive computer systems to aid designers are also put forwar

Integración de principios inventivos de TRIZ en sistema de diseño conceptual asistido por ordenador (CAD)

Ponencia presentada en el IX Congreso Internacional de Ingeniería de Proyectos celebrado en Málaga en el año 2005The work presented proposes the integration of TRIZ inventive principles as criteria for searching design alternatives in functional reasoning CACD systems. This approach enhances the exploration of different kinds of solutions and stimulates designers’ creativity by means of a synthesis process oriented by inventive principles, thus implementing aspects concerning CAI systems in an initial divergent scheme in order to guide the designer to search for more innovative alternatives.Este trabajo propone la integración de los principios inventivos de TRIZ como criterio de búsqueda de alternativas en sistemas CACD basados en razonamiento funcional con el fin de ampliar las posibilidades de explorar distintas soluciones y de estimular la creatividad del diseñador. La aproximación presentada permite explorar distintas alternativas mediante un proceso de síntesis orientado por los principios inventivos, implementado así parte de la filosofía de los sistemas de invención asistida por ordenador (CAI) en un esquema inicial divergente, para guiar al diseñador a la búsqueda de alternativas que acerquen a la innovación