Development of a hybrid dextrin hydrogel encapsulating dextrin nanogel as protein delivery system

Dextrin, a glucose polymer with low molecular weight, was used to develop a fully resorbable hydrogel, without using chemical initiators. Dextrin was first oxidized (oDex) with sodium periodate and then cross-linked with adipic acid dihidrazide, a nontoxic cross-linking molecule. Furthermore, a new bidimensional composite hydrogel, made of oxidized dextrin incorporating dextrin nanogels (oDex-nanogel), was also developed. The oDex hydrogels showed good mechanical properties and biocompatibility, allowing the proliferation of mouse embryo fibroblasts 3T3 cultured on top of the gel. The gelation time may be controlled selecting the concentrations of the polymer and reticulating agent. Both the oDex and oDex-nanogel hydrogels are biodegradable and present a 3-D network with a continuous porous structure. The obtained hybrid hydrogel enables the release of the dextrin nanogel over an extended period of time, paralleling the mass loss curve due to the degradation of the material. The dextrin nanogel allowed the efficient incorporation of interleukin-10 and insulin in the oDex hydrogel, providing a sophisticated system of controlled release. The new hydrogels present promising properties as an injectable carrier of bioactive molecules. Both proteins and poorly water-soluble low-molecular-weight drugs are efficiently encapsulated in the nanogel, which performs as a controlled release system entrapped in the hydrogel matrix.V.C. and D.S. were supported by the grants SFRH/BD/27359/2006 and SFRH/BD/64571/2009, respectively, from Fundacao para a Ciencia e Tecnologia (FCT), Portugal. We thank FCT funding through PTDC and COMPETE

Ocean currents modify the coupling between climate change and biogeographical shifts

Biogeographical shifts are a ubiquitous global response to climate change. However, observed shifts across taxa and geographical locations are highly variable and only partially attributable to climatic conditions. Such variable outcomes result from the interaction between local climatic changes and other abiotic and biotic factors operating across species ranges. Among them, external directional forces such as ocean and air currents influence the dispersal of nearly all marine and many terrestrial organisms. Here, using a global meta-dataset of observed range shifts of marine species, we show that incorporating directional agreement between flow and climate significantly increases the proportion of explained variance. We propose a simple metric that measures the degrees of directional agreement of ocean (or air) currents with thermal gradients and considers the effects of directional forces in predictions of climate-driven range shifts. Ocean flows are found to both facilitate and hinder shifts depending on their directional agreement with spatial gradients of temperature. Further, effects are shaped by the locations of shifts in the range (trailing, leading or centroid) and taxonomic identity of species. These results support the global effects of climatic changes on distribution shifts and stress the importance of framing climate expectations in reference to other non-climatic interacting factors

Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty

[EN] The regulation of water services shares many similarities with that of other utilities such as electricity or telecommunications. As a result, similar methods are often used by regulators to assess the efficiency of companies in those sectors. Data Envelopment Analysis (DEA) is one of those widely applied methods. This paper aims to determine the adequacy of DEA as a regulatory tool for urban water services, with a special focus on the quality of the available data. In order to obtain useful conclusions, two DEA simulations were performed with audited data from 194 water utilities, officially made available by the Portuguese water regulatory authority (ERSAR). Both simulations will demonstrate that the inherent inaccuracies found in some of the key data provided by water utilities represent a significant obstacle to obtain meaningful results with the DEA technique. This could represent a paradigm shift for some of the regulatory authorities currently using DEA or similar techniques, as the complexity of the method does not seem to be justified by a better analysis of the comparative performance of the different services.Cabrera Rochera, E.; Estruch-Juan, ME.; Molinos-Senante, M. (2018). Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty. Environmental Science & Policy. 85:155-162. https://doi.org/10.1016/j.envsci.2018.03.028S1551628

Evaluation of the impact of separative collection and recycling of municipal solid waste on performance: An empirical application for Chile

The collection of municipal solid waste (MSW) is a public service with notable effects on the environment and public health. The objective of this study was to evaluate the impact of selective collection and recycling of MSW on the performance of municipalities in providing MSW services. By employing the data envelopment analysis method, the efficiency and eco-efficiency scores for a sample of 298 municipalities in Chile were analyzed and compared. The efficiency estimation focused on the economic performance of the municipalities in the provision of MSW services, whereas the eco-efficiency assessment also integrated the environmental performance. The results indicated that the selective collection and recycling of MSW had a significant impact on the performance of the municipalities in providing these services. The percentages of efficient and ecoefficient municipalities were very low (4.70% and 4.36%, respectively), thus demonstrating the large room for performance improvement by Chilean municipalities in the management of MSW. The efficient and eco-efficient municipalities were heterogeneously distributed throughout the country, revealing the lack of collaboration between municipalities at the regional level. Finally, exogenous variables to the management of MSW carried out by the municipalities, including the population served, population density, tourism and waste generated per capita, all had an impact on the efficiency and eco-efficiency scores. The results and conclusions of this study are of great relevance for policy makers at the regional and local levels to improve the management of MSW in the context of a circular economy

Criminal Trajectories and Educational Measures in the Juvenile Court

El objetivo general de este trabajo fue el de determinar el perfil de los menores que acuden al juzgado, según sus trayectorias delictivas, en cuanto al tipo de delito y la medida propuesta. Los participantes de este estudio fueron 210 menores del Juzgado de Castellón, de edades entre 14.03 y 18.1 años. Las trayectorias de los menores reincidentes (23.15) correspondieron, en mayor medida, a delitos cometidos contra la propiedad 51.2% (delitos cometidos contra las personas = 48.8%). Por otra parte, a medida que iba aumentando la restricción de la medida, se incrementaba la reincidencia. Las medidas que contaron con un porcentaje más alto de reincidencia fueron: tratamiento ambulatorio (66.7%), tareas socioeducativas (53.8%), internamiento y (50%) y libertad vigilada (47.2%).The aim of this study is to define a profile of juvenile offenders with a criminal record in the juvenile court, according to their criminal trajectory, depending on the type of crime and educational measure. Participants were 210 adolescents between the ages of 14.03 and 18.10. Results showed recidivism trajectories (23.15%) that property-related offences were more present 51.2%, (offences against persons, and 48.8%). On the other hand as the educational measure is more punitive, the amount of minors with more criminal records is higher. The educational measures with the higher recidivism rates are: Outpatient services (66.7%), Socio-educational tasks (53.8%), Confinement in closed centres (50%) and Probation (47.2%)

Stabilized explicit u- pw solution in soil dynamic problems near the undrained-incompressible limit

Traditionally, Biot’s formulation is employed to model the behavior of saturated soils. The u- pw (solid displacement–pore water pressure) formulation can be considered as the standard one, since involves a good computational performance together with excellent accuracy for slow and moderate speed phenomena. Dynamic processes can be studied even if the acceleration of the water is neglected, what occurs in the undrained limit. It is well-known that u- pw formulation might display instabilities in the undrained-incompressible limit. Several techniques have been proposed to overcome this issue, principally within an implicit time integration scheme for small strains. In this paper, a robust implementation of the divergence of the momentum equation technique is presented for an explicit u- pw approach within the framework of optimal transportation meshfree scheme at finite strain. Several examples are provided in order to assess the good performance of the proposed methodology.Fil: Navas, Pedro. Universidad Politécnica de Madrid; EspañaFil: Stickle, Miguel M.. Universidad Politécnica de Madrid; EspañaFil: Yagüe, Angel. Universidad Politécnica de Madrid; EspañaFil: Manzanal, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad Politécnica de Madrid; EspañaFil: Molinos, Miguel. Universidad Politécnica de Madrid; EspañaFil: Pastor, Manuel. Universidad Politécnica de Madrid; Españ

Homogeneity problem for basis expansion of functional data with applications to resistive memories

The homogeneity problem for testing if more than two different samples come from the same population is considered for the case of functional data. The methodological results are motivated by the study of homogeneity of electronic devices fabricated by different materials and active layer thicknesses. In the case of normality distribution of the stochastic processes associated with each sample, this problem is known as Functional ANOVA problem and is reduced to test the equality of the mean group functions (FANOVA). The problem is that the current/voltage curves associated with Resistive Random Access Memories (RRAM) are not generated by a Gaussian process so that a different approach is necessary for testing homogeneity. To solve this problem two different parametric and nonparametric approaches based on basis expansion of the sample curves are proposed. The first consists of testing multivariate homogeneity tests on a vector of basis coefficients of the sample curves. The second is based on dimension reduction by using functional principal component analysis of the sample curves (FPCA) and testing multivariate homogeneity on a vector of principal components scores. Different approximation numerical techniques are employed to adapt the experimental data for the statistical study. An extensive simulation study is developed for analyzing the performance of both approaches in the parametric and non-parametric cases. Finally, the proposed methodologies are applied on three samples of experimental reset curves measured in three different RRAM technologies

Two-phase SPH modelling of a real debris avalanche and analysis of its impact on bottom drainage screens

Rapid flow-like landslides, particularly debris flows and debris avalanches, cause significant economic damage and many victims worldwide every year. They are usually extremely fast with the capability of travelling long distances in short times, sweeping away everything in their path. The principal objective of this paper is to test the ability of the ‘GeoFlow-SPH’ two-phase model developed by the authors, to reproduce the complex behaviour of natural debris avalanches where pore-water pressure evolution plays a key role. To reach this goal, the model is applied to reproduce the complex dynamic behaviour observed in Johnsons Landing debris avalanche including the observed bifurcation caused by the flowing out of part of the moving mass from the mid-channel. Initial thickness deposit trim-line, distribution of deposit volume, and the average velocities were provided for this real case, making it an appropriate case to validate the developed model. The paper also contributes to evaluate the SPH-FD model’s potentialities to simulate the structural countermeasure, like bottom drainage screens, used to reduce the impact of debris flows. The analysis of the results shows the adequacy of the proposed model to solve this complicated geophysical problem.Fil: Tayyebi, Saeid M.. Universidad Politécnica de Madrid; EspañaFil: Pastor, Manuel. Universidad Politécnica de Madrid; EspañaFil: Stickle, Miguel M.. Universidad Politécnica de Madrid; EspañaFil: Yagüe, Ángel. Universidad Politécnica de Madrid; EspañaFil: Manzanal, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad Politécnica de Madrid; EspañaFil: Molinos, Miguel. Universidad Politécnica de Madrid; EspañaFil: Navas, Pedro. Universidad Politécnica de Madrid; Españ

Mejora de la seguridad y la vida útil de alimentos de origen vegetal mediante métodos biológicos

Los alimentos de origen vegetal están a menudo implicados en la aparición de brotes de intoxicaciones alimentarias. El control biológico de los microorganismos patógenos o alterantes en alimentos vegetales no deja de ser una herramienta interesante, como lo demuestra la intensidad de los estudios realizados en este campo sobre los agentes antimicrobianos producidos por microorganismos, en especial los conocidos como bacteriocinas, así como los antimicrobianos naturales presentes en las plantas y sus aceites esenciales. Los bacteriófagos son una herramienta muy interesante para la inactivación de patógenos en alimentos, como lo demuestra el reciente desarrollo de preparados comerciales. Los antimicrobianos naturales funcionan mejor cuando se emplean como parte de la tecnología de obstáculos o barreras, pudiendo establecer efectos sinérgicos con otros agentes antimicrobianos o con tratamientos físico químicos.Vegetable foods are often involved in outbreaks of foodborne illnesses. Biological control of human pathogenic and food spoiling bacteria in vegetable foods still remains a viable approach, as shown by the numerous studies published in recent years on antimicrobial substances from microorganismos, especially the so-called bacteriocins, as well as on plant-derived natural antimicrobial compounds and essential oils. Bacteriophages are also a relevant tool for inactivation of foodborne pathogens, as shown by recent development of commercial phage preparations. The efficacy of natural antimicrobials can be improved considerably if they are used as part of hurdle technology, since they can act synergistically with other antimicrobials or with physico-chemical treatments

Phase-type distributions for studying variability in resistive memories

A new statistical approach has been developed to analyze Resistive Random Access Memory (RRAM) variability. The stochastic nature of the physical processes behind the operation of resistive memories makes variability one of the key issues to solve from the industrial viewpoint of these new devices. The statistical features of variability have been usually studied making use of Weibull distribution. However, this probability distribution does not work correctly for some resistive memories, in particular for those based on the Ni/HfO2/Si structure that has been employed in this work. A completely new approach based on phase-type modeling is proposed in this paper to characterize the randomness of resistive memories operation. An in-depth comparison with experimental results shows that the fitted phase-type distribution works better than the Weibull distribution and also helps to understand the physics of the resistive memories