Geochemistry and risk assessment of street dust in Luanda, Angola, a tropical urban environment

A total of 92 samples of street dust were collected in Luanda, Angola, were sieved below 100 μm, and analysed by ICP-MS for 35 elements after an aqua-regia digestion. The concentration and spatial heterogeneity of trace elements in the street dust of Luanda are generally lower than in most industrialized cities in the Northern hemisphere. These observations reveal a predominantly “natural” origin for the street dust in Luanda, which is also manifested in that some geochemical processes that occur in natural soils are preserved in street dust: the separation of uranium from thorium, and the retention of the former by carbonate materials, or the high correlation between arsenic and vanadium due to their common mode of adsorption on solid particles in the form of oxyanions. The only distinct anthropogenic fingerprint in the composition of Luanda's street dust is the association Pb–Cd–Sb–Cu (and to a lesser extent, Ba–Cr–Zn). The use of risk assessment strategies has proved helpful in identifying the routes of exposure to street dust and the trace elements therein of most concern in terms of potential adverse health effects. In Luanda the highest levels of risk seem to be associated (a) with the presence of As and Pb in the street dust and (b) with the route of ingestion of dust particles, for all the elements included in the study except Hg, for which inhalation of vapours presents a slightly higher risk than ingestion. However, given the large uncertainties associated with the estimates of toxicity values and exposure factors, and the absence of site-specific biometric factors, these results should be regarded as preliminary and further research should be undertaken before any definite conclusions regarding potential health effects are drawn

Evaluación geoquímica de las propiedades del material particulado (polvo, suelos y sedimentos) de la ciudad de Luanda (Angola) y su entorno : implicaciones ambientales

En esta Tesis se ha realizado un estudio minucioso del entorno que es la ciudad de Luanda y sus alrededores, partiendo por establecer una metodología capaz de permitir el conocimiento de las características del medio en su globalidad, teniendo en cuenta los procesos que ahí que se producen y las actividades realizadas en su entorno. El trabajo consistió fundamentalmente en determinar las propiedades físico-químicas de tres medios a través de sus materiales particulados: polvo, suelos y sedimentos (de costa y de arroyos de la ciudad). Para el efecto, se han analizado un total de 222 muestras, siendo 92 de polvo urbano, 63 de sedimentos de costa, 10 de sedimentos de arroyos y 57 de suelos o formaciones geológicas del entorno de la ciudad. Se han determinado fundamentalmente las propiedades física y físico-químicas como la textura de los suelos, el pH, la conductividad eléctrica, el porcentaje de materia orgánica, el porcentaje de oxihidróxidos de hierro y manganeso, el porcentaje de carbonates y el contenido de 35 elementos químicos incluyendo algunos de relevancia medioambiental. El conjunto de propiedades estudiadas nos han servido para caracterizar el entorno y los medios estudiados, pero uno de los enfoques en que se ha profundizado con esmero y detalle es en relación al comportamiento de los diferentes elementos químicos determinados en los tres materiales y en el medio urbano en particular. De ahí, ha sido posible demostrar que los elementos traza en el medio urbano se encuentran sometidos a los mismos procesos físico-químicos que tienen lugar en el medio natural. Así, se ha podido estudiar su comportamiento utilizando los modelos y herramientas similares a aquellos que tradicionalmente han sido utilizados para el estudio de los sistemas y medios naturales. Los datos obtenidos han demostrado que el polvo de la ciudad de Luanda tiene una composición que depende fundamentalmente de procesos de origen natural, caracterizado por contenidos relativamente bajos en metales y elementos traza en relación a otros entornos urbanos de ciudades más desarrolladas, aunque con valores moderadamente altos para el Pb y Zn. También se ha podido observar que quizás debido a la gran contribución de fuentes naturales, tiene un carácter carbonatado acentuado y una relativa homogeneidad en su variabilidad espacial. systems, such as precipitation and catión exchange, have modified in certain way the commonly accepted approach that establish that at high valúes of pH, a higher Pb adsorption is observed, it means, that in this investigation, at higher valúes of pH, lower lead adsorption has been observed than at lower pH valúes in the same system. En relación a la costa, las diferentes propiedades determinadas, presentan una variación fluctuante, que obedece a dos criterios fundamentalmente: la diferencia litológica a lo largo de la costa y la intensidad o el aporte de materiales provenientes de la ciudad (actividad antrópica). Se ha podido constatar sobretodo que la bahía es una de las áreas de la costa más impactadas por la actividad humanas atendiendo los elevados contenidos de metales pesados que acumulan sus sedimentos con especial relevancia para Ag, Cu, Pb y Zn, que se mostrado ser superiores a los valores habitualmente considerados óptimos y compatibles para los medios marinos y la vida acuática. Ha sido fundamentalmente interesante observar en como la ciudad es la principal fuente de elementos traza a los sedimentos tanto de arroyo como de costa. Finalmente, a través de un estudio aplicado a la evaluación de riesgo que la exposición al polvo representa para los niños en Luanda, se ha determinado que los elementos traza que suponen un mayor riesgo para la salud son el arsénico y el plomo, y que la ingestión de partículas es la ruta de mayor riesgo para casi todos los elementos considerados, lo que amplia la probabilidad de que los niños puedan sufrir efectos adversos derivados de algunos elementos ya que la costumbre de llevar objetos no comestibles a la boca implica la ingestión de mayores cantidades de polvo y consecuentemente mayores de tóxicos

Motorways, sprawl, and the (un)sustainable economy

Mestrado Bolonha em ManagementUrban sprawl is usually addressed with a negative connotation due to its negative impacts on land uptake and contribution to a greater dependence on the automobile, which subsequently affects the environment as more fuel is consumed and more greenhouse gas emissions are emitted. There is also international evidence that investments in motorways have promoted urban expansion models akin to urban sprawl, particularly low density and dispersed suburbanization patterns. Portugal has one of the densest motorway networks in the EU and experienced a relatively late process of urbanization compared to other European countries. We study the relationship between motorways, urban sprawl and its impacts on travel mobility patterns and fuel consumption for Portugal over the period from 1991 to 2011. The results show that both motorways and urban sprawl have played a role in the shift in travel mobility towards greater automobile dependency and greater fuel consumption, which limit the country’s ability to meet the climate change targets set out in the national strategy for carbon neutrality by 2050.info:eu-repo/semantics/publishedVersio

Political debate on weblogs : a virtual public sphere for deliberation

info:eu-repo/semantics/publishedVersio

Deliberation in the classroom : on the potential of deliberative ideals for a more civic education

This article seeks to answer a very simple question: what is promising about deliberation in school education?For that, it sets out to examine how deliberative democracy can provide new ways to consider educational practices, from a civic perspective. In other words, it seeks to identify the possible and advantageous approaches linking the ideals of deliberative democracy and the educational process. It starts reviewing the idea of public deliberation, presenting it as a proposal to achieve informed, participated and founded decision-making. It could be possible to obtain a more civic and autonomous process of education throughan ethical use of discourse (Habermas). In the second part of the article, we will attempt to show how deliberative ideals can be applied, advantageously, in the classroom. To this extent, the autonomy of individuals (students) to participate in reasoningprocesses of problem solving as well as the ability to receive and accommodate different views and diverse experiences will be emphasized. This perception highlights the need to incorporate deliberative normative ideals in the classroom.info:eu-repo/semantics/publishedVersio

The Influence of oral environment on diet choices in goats: a focus on saliva protein composition

There is ample evidence that ruminants are capable of making choices between different foods that provide a more balanced diet that would be obtained by eating at random. In the particular case of goats, they occupy a diversity of habitats and different breeds present variability of feeding behaviors resultant from adaptations to the existent plant species. In their food search activity, individuals are faced with variable amounts of plant secondary metabolites (PSMs), which may present some toxic and anti-nutritional effects depending on the individual’s ability to deal with it. The oral cavity has a key role in the recognition and decision processes of ingestion or rejection. In this chapter we will first consider how goats identify foods and behave according to the food items available. Focus will be done on the importance of taste sense in this process and the information available on the main structures involved in taste detection and perception in goats will be reviewed. In a second section we will focus on the characteristics of goat’s saliva, particularly in terms of their protein composition, presenting results obtained by our research team

Criação de um banco de recursos humanos : uma proposta no âmbito das instituições particulares de solidariedade social

Dissertação de mestrado em Gestão (área de especialização em Gestão de Unidades de Saúde)Toda a crise é uma oportunidade de mudança. A nova conjuntura sócio-económica desafia as Instituições Particulares de Segurança Social (IPSS) a assegurarem a satisfação das necessidades dos utentes com uma gestão cada vez mais eficaz e eficiente dos recursos humanos. O recrutamento destes colaboradores especializados é essencial, mas terá de ser feito à medida dos interesses e ajustado ao grau de investimento de cada instituição - o grande objectivo é manter os recursos humanos, técnicos e materiais adequados para a melhor prestação de serviços possível. Neste sentido, propomo-nos estudar a viabilidade da criação de um banco de recursos humanos, com o objetivo de fornecer os recursos técnicos a todas as IPSS do concelho. Ou seja, o banco recruta os recursos humanos especializados na área da saúde, necessários a cada instituição e estes dividem o seu tempo de trabalho pelas várias IPSS, de forma sistémica e devidamente articulada. As vantagens enquadram-se sobretudo na otimização dos serviços prestados, no fortalecimento da competitividade, no aumento da eficiência e da eficácia dos meios disponíveis e no ganho do tempo. Pretende-se, portanto, comprovar que com a criação deste banco de recursos é possível fornecer o maior número de recursos humanos ao menor custo possível garantindo uma maior eficiência dos recursos e uma melhor qualidade de serviço, numa perspetiva de empreendedorismo social. Assim, estaria garantido que todas as instituições do concelho da Póvoa de Lanhoso poderiam usufruir dos mesmos serviços, em todas as dimensões da dinâmica de cada instituição, garantindo, a todas, a melhor qualidade.Every crisis presents an opportunity of change. The new social-economic situation challenges Instituições Particulares de Segurança Social (IPSS) to ensure the needs of their users, in a more efficient and effective way than ever. Managing human resources in a smart way might help to greatly reduce costs and furthermore safeguard the quality of the delivered service. While the recruitment of trained professionals is by no means expendable, it should be adjusted to the interests and level of investment of each institution. We then propose to assess the viability of creating a “bank of human resources”, aiming to provide for every IPSS in the region of Póvoa de Lanhoso. The bank would recruit specialized workforce, which would divide its time amongst several institutions, on a systemic and properly articulated way. Advantages lie, above all, on optimization of delivered services, strengthening of competitiveness, raise in efficiency and effectiveness of available resources, and finally, time sparing. It is therefore intended to prove that by creating this resource bank, it is possible to supply the greatest number of human resources at the lowest possible cost, ensuring a greater efficiency of resource usage as well as an improvement of service quality, on a perspective of social entrepreneurship. In this way, all institutions in the region of Póvoa de Lanhoso could benefit from the same services and provide their users the best quality on every type of service