Synthetic building block for hierarchical tissue engineering

We focus on designing biomaterial systems for hierarchical tissue engineering. Polymeric molecular and nano- to micron-scale building blocks are assembled into soft 3D biomimetic constructs, which allow studying and controlling cell/material interactions that are difficult or impossible to investigate with current material systems.[1] These biomaterial platforms can then be applied to build ex vivo tissue models for drug testing or investigating pathologies, to grow tissue or organs ex vivo for transplantation in vivo, or for in vivo tissue regenerative therapies. The hybrid artificial biomaterial matrices consist of a polymeric crosslinked network and colloids to create macroscopic structures with new properties. Microgels and fibers are produced by adapted technologies based on fiber spinning, microfluidics, and in-mold polymerization. To arrange the building blocks in a spatially controlled manner, we rely on self-assembly mechanisms and assembly by external fields (e.g., magnetic). A better understanding of cellular processes in contact with synthetic biomaterials will supply information about the parameters, which are most important to make viable and functional regenerative materials for clinical use in a modular manner. The different methods are applied to embed and grow cells in micro-containers to form mini-tissues for transplantation or load specific biological molecules to control temporal release [2], and produce structural magnetic elements that can be aligned for cell guidance. Due to their size, the micro-objects can be injected, with or without a surrounding hydrogel. Their internal structure and degradation properties enable temporal control of tissue formation. To obtain anisotropic matrices after injection, rod-shaped elements are rendered magneto-responsive by the incorporation of superparamagnetic iron oxide nanoparticles. Due to their anisometric shape, the elements align parallel to a low external mTesla magnetic field, after which a surrounding hydrogel can crosslink to fix their unidirectional orientation after removal of the magnetic field. Fibroblasts and nerve cells sense the mechanical anisotropy, induced by a minimal amount of oriented structures, resulting in directed cell growth inside 3D hydrogels.[3] Modification of the guiding elements with adhesive peptides enhances the overall cell alignment, reduces ECM production, and increases nuclear shuttling of mechanosensitive proteins, such as YAP/TAZ.[4] Neurons inside the Anisogel show spontaneous electrical activity proving neuronal functionality and importantly, electrical signals propagate along the anisotropy axis of the material.[5] The developed hybrid hydrogel can be applied as a low invasive, injectable material to repair complex, sensitive tissues, such as the spinal cord. [1] Rose J, De Laporte L. Hierarchical design of tissue regenerative constructs. Review paper. Advanced Healthcare Materials. Published Online January 2018. [2] Guerzoni LPB, De Laporte L et al. Microfluidic fabrication of polyethylene glycol microgel capsules with tailored properties for the delivery of biomolecules. Biomaterials Science. 2017 Aug; 5(8): 1549-57. [3] Rose J, De Laporte L et al. Nerve cells decide to orient inside an injectable hydrogel with minimal structural guidance. Nano Letters, 2017 Jun; 17(6): 3782-91. [4] Rose JC, Gehlen DB, Haraszti T, Köhler J, Licht CJ, De Laporte L. Biofunctionalized aligned microgels to provide 3D cell guidance to mimic complex tissue matrices. Biomaterials, Published Online February 2018 [5] Omidinia-Anarkoli A, De Laporte L et al. An injectable hybrid hydrogel with oriented short fibers induces unidirectional growth of functional nerve cells. Small, 2017 Sept; 13(36

What Do We Know about Mineral Resource Rent Sharing in Africa?

taxation; mineral tax; resource rent tax; developing countries.Governments that lack the capacity to mine resources themselves have to attract foreign direct investment. However, since resources are not renewable countries need to capture a ‘fair’ share of mineral resource rent to promote their development. While the sharp rise of the world prices of most minerals (in particular, gold, copper, iron and bauxite) multiplied the global turnover of the mining sector by 4.6 between 2002 and 2010, tax revenue earned by African governments from the non-renewable natural resource sector only grew by a factor of 1.15 (Mansour 2014). The sharing of mineral resource rent between governments and investors is often criticised for being unfavourable to African governments. But what do we really know about the sharing of mineral resource rent in Africa? The aim of this study is to review theoretical and empirical studies on rent sharing in Africa, and to note their limitations regarding knowledge of the actual sharing of mineral rent.DfID, NORA

A real delivery problem dealt with Monte Carlo techniques

[EN] In this paper we use Monte Carlo Techniques to deal with a real world delivery problem of a food company in Valencia (Spain). The problem is modeled as a set of 11 instances of the well known Vehicle Routing Problem, VRP, with additional time constraints. Given that VRP is a NP-hard problem, a heuristic algorithm, based on Monte Carlo techniques, is implemented. The solution proposed by this heuristic algorithm reaches distance and money savings of about 20% and 5% respectively.This research was partially supported by MICINN, Project MTM2013-43540-P and by UPV, Project Programa de Apoyo a la Investigación y Desarrollo de la UPV PAID-06-12.S577181Fernández de Córdoba, P., L.M. García-Raffi and J.M. Sanchis Llopis (1998), A heuristic algorithm based on Monte Carlo methods for the Rural Postman Problem.Computers and Op. Research,25, No. 12, pp. 1097–1106, 1998.Fernández de Córdoba, P. and L.M. García-Raffi, E. Nieto and J.M. Sanchis Llopis (1999a), Aplicación de técnicas Monte Carlo a un problema real de Rutas de Vehículos.Anales de Ingeniería, Colombia. In press.Fernández de Córdoba, P., L.M. García-Raffi and J.M. Sanchis Llopis (1999b), A Constructive Parallel Algorithm based on Monte Carlo techniques for Routing Problems, Submitted toParallel Computers.Laporte, G. (1992), The Vehicle Routing Problem: an overview of exact and approximate algorithms,European Journal of Operations Research,59, 345.Laporte, G., M. Desrochers and Y. Nobert (1985), “Optimal Routing under Capacity and Distance Restrictions.Operations Research,33, pp. 1050–1073.Laporte G. and Y. Nobert (1987), Exact algorithms for The Vehicle Routing Problem,Surveys in Combinatorial Optimization (S. Martello, G. Laporte, M. Minoux and C. Ribeiro Eds.). North-HollandAmsterdamMayado, A. (1998), Organización de los itinerarios de la flota de camiones de reparto de una sociedad cooperativa. Optimización mediante técnicas de simulación Monte Carlo. Proyecto Fin de Carrera. E.T.S.I.I. Universidad Politécnica de Valencia

La fiscalité minière en Afrique : un état des lieux du secteur de l’or dans 14 pays de 1980 à 2015

The lack of information about the mining resource rent sharing between governments and investors is an easy statement in Africa. Existing public databases are often insufficient for a deep analysis of the African tax law applied to natural resource sectors, which limits the academic and operational work. The FERDI publishes the first tax and legal database which specifies the tax regime applied to industrial gold mining companies in 14 African countries from the 1980s to 2015. The database featuring three major innovations: (i) an inventory of taxes and duties (rate, base and exemptions) payable during the prospecting phase and mining phase of a gold mining project; (ii) an entirely new level of historical depth; (iii) the link between each piece of tax information and its legal source. This database is used to make a first analysis of tax regimes and rent sharing in gold producer countries. The first results emphasize heterogeneity of tax regimes between English-speaking and French-speaking countries with a convergence of the average effective tax rates that increase in most countries following the tax reforms undertaken since 2010

La fiscalité minière en Afrique : quelle évolution récente en 2018 ?

The extractive sector is of primary importance to African states. Of the 54 countries on the continent, 20 are considered by the International Monetary Fund (IMF) to be rich in natural resources. These are countries whose natural resources account for more than 25 per cent of total exports. All are sub-Saharan African countries: seven export mainly oil and gas, and 13 export mainly minerals: mostly gold, diamonds and precious stones. The significant weight of the extractive sector in these states raises the question of the taxation of these natural resources, which are non-renewable. An innovative database on the taxation of mining industries in Africa has been put online on the Ferdi website, in partnership with Cerdi and ICTD. This database covers 21 sub-Saharan African countries over a period that varies according to the availability of information in each country but can go back to the 1980s. It was created based on the tax legislation and regulations of each country, essentially the income tax acts, finance acts and mining acts. It separates the general regime (applicable to all companies) from the mining regime (applicable only to holders of mineral rights for prospecting or exploitation on an industrial scale). It focuses on a single ore: gold.Le secteur extractif est de première importance pour les Etats africains. Sur les 54 pays que compte le continent, 20 sont considérés comme riches en ressources naturelles par le Fonds Monétaire International (FMI)1. Il s’agit des pays dont les ressources naturelles représentent plus de 25% des exportations totales. Tous sont des pays d’Afrique sub-saharienne : 7 exportent principalement du pétrole et du gaz, 13 exportent principalement des minerais : surtout de l’or, des diamants et des pierres précieuses. Le poids conséquent du secteur extractif dans ces Etats pose la question de la taxation de ces ressources naturelles qui sont non-renouvelables. Une base de données inédite sur la fiscalité des industries minières en Afrique a été mise en ligne sur le site de la Ferdi, en partenariat avec le Cerdi et l’ICTD. Cette base de données couvre 21 pays d’Afrique sub-saharienne sur une période qui varie selon la disponibilité de l’information dans chaque pays mais peut remonter jusque dans les années 1980. Elle a été constituée à partir de la législation et de la réglementation fiscale de chaque pays, essentiellement les codes généraux des impôts, les lois de finances, les codes miniers et leurs textes d’application. Elle distingue le régime général (applicable à toutes les entreprises) du régime minier (applicable aux seuls titulaires de titres miniers de recherche ou d’exploitation à l’échelle industrielle). Elle se concentre sur un seul minerai : l’or

Digitally Fabricated and Naturally Augmented In Vitro Tissues

Human in vitro tissues are extracorporeal 3D cultures of human cells embedded in biomaterials, commonly hydrogels, which recapitulate the heterogeneous, multiscale, and architectural environment of the human body. Contemporary strategies used in 3D tissue and organ engineering integrate the use of automated digital manufacturing methods, such as 3D printing, bioprinting, and biofabrication. Human tissues and organs, and their intra- and interphysiological interplay, are particularly intricate. For this reason, attentiveness is rising to intersect materials science, medicine, and biology with arts and informatics. This report presents advances in computational modeling of bioink polymerization and its compatibility with bioprinting, the use of digital design and fabrication in the development of fluidic culture devices, and the employment of generative algorithms for modeling the natural and biological augmentation of in vitro tissues. As a future direction, the use of serially linked in vitro tissues as human body-mimicking systems and their application in drug pharmacokinetics and metabolism, disease modeling, and diagnostics are discussed. © 2020 The Authors. Advanced Healthcare Materials published by Wiley-VCH Gmb

Planning rapid transit networks

[EN] Rapid transit construction projects are major endeavours that require long-term planning by several players, including politicians, urban planners, engineers, management consultants, and citizen groups. Traditionally, operations research methods have not played a major role at the planning level but several tools developed in recent years can assist the decision process and help produce tentative network designs that can be submitted to the planners for further evaluation. This article reviews some indices for the quality of a rapid transit network, as well as mathematical models and heuristics that can be used to design networks. © 2011 Elsevier Ltd.This research was partly funded by the Canadian Natural Sciences and Engineering Research Council under grant no. 39682-10, the Spanish Ministry of Science and Innovation under grant no. MTM 2009-14243 and the Junta de Andalucía, Spain, under grant no. P09-TEP-5022. This support is gratefully acknowledged. Fig. 10 was kindly provided by Giuseppe Bruno. Thanks are due to a referee who provided several valuable comments on an earlier version of this paper.Laporte, G.; Mesa, J.; Ortega, F.; Perea Rojas Marcos, F. (2011). Planning rapid transit networks. Socio-Economic Planning Sciences. 45(3):95-104. https://doi.org/10.1016/j.seps.2011.02.001S9510445

Design Thinking as a Framework for Teaching Packaging Innovation

Students in scientific/technical-oriented disciplines struggle with achieving good levels of innovation when exposed to design problems. Research indicates the need for implementing alternative pedagogical approaches in technical curricula that enhance students’ creative skills. The purpose of this study was to evaluate the implementation of a cross-disciplinary pedagogical approach with a focus on teaching innovation in the field of packaging engineering at a university in the United States. A Design Thinking Project-Based Learning (DTPBL) approach was used to improve the levels of innovation in student work. Its outcomes were compared with those of a Traditional Project-Based Learning (TPBL) approach. The implementation of DTPBL across several courses took place between 2015 and 2018. TPBL was the norm in these courses between 2009 and 2014. National and international student design competitions were used to assess the level of innovation of student work externally. Statistically significant differences were found in the levels of innovation of student work between approaches. DTPBL projects placed higher in design competitions, and they were recognized more often by independent expert judges than TPBL projects. At a national level, TPBL generated 172 projects in 11 instances, obtaining 12 awards. DTPBL produced 61 projects in seven instances, and student work was recognized with 21 awards. At a global level, student work created with TPBL was never recognized, while student projects generated using DTPBL received seven recognitions in three participation instances. This study provides evidence that a Design Thinking Project-Based Learning (DTPBL) approach can be a successful pedagogical strategy to enhance students’ creative skills and produce innovative design solutions

A atenção nutricional ao pré-natal e puerpério: relato de experiência em um município do litoral Paulista

The purpose of this study is to present a report of the experiences of the adoption of the Approach to Nutritional Care during Prenatal and Postpartum Periods, resulting from a partnership between the university and the municipal primary health care system of Santos, SP, Brazil. This approach was developed through joint work plans based on the need to incorporate nutritional care into the prenatal and postpartum care. All stages of design and implementation and the results of this strategy were documented in a field diary. This approach was adopted in two basic health units between 2010 and 2014. The stages of this process were planned in conjunction with health care teams and consisted of putting together interdisciplinary groups for nutrition education during the prenatal period. Interdisciplinary educational group meetings were held focusing on listening to the needs of pregnant women, the provision of prenatal nutritional care, and on the project to monitor the nutritional status of newborns through home visits up to the 15 days of postpartum. The interdisciplinary activities strengthened the bond between the users and the health care team members, contributing to the provision of effective care and promoting integrality. Home visiting contributed to encourage exclusive breastfeeding.Univ Fed Sao Paulo, Inst Saude & Sociedade, Curso Nutr, Santos, SP, BrazilUniv Fed Sao Paulo, Inst Saude & Sociedade, Dept Polit Publ & Saude Colet, Campus Baixada Santista R Silva Jardim 136, BR-11015020 Santos, SP, BrazilUniversidade Federal de São Paulo, Instituto Saúde e Sociedade, Curso de Nutrição. Santos, SP, BrasilUniversidade Federal de São Paulo, Instituto Saúde e Sociedade, Departamento de Políticas Públicas e Saúde Coletiva. Campus Baixada Santista R. Silva Jardim, 136, Vila Matias, 11015020, Santos, SP, BrasilWeb of Scienc