Environmental Risk Assessment Based on High-Resolution Spatial Maps of Potentially Toxic Elements Sampled on Stream Sediments of Santiago, Cape Verde

Geochemical mapping is the base knowledge to identify the regions of the planet with critical contents of potentially toxic elements from either natural or anthropogenic sources. Sediments, soils and waters are the vehicles which link the inorganic environment to life through the supply of essential macro and micro nutrients. The chemical composition of surface geological materials may cause metabolic changes which may favor the occurrence of endemic diseases in humans. In order to better understand the relationships between environmental geochemistry and public health, we present environmental risk maps of some harmful elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn) in the stream sediments of Santiago, Cape Verde, identifying the potentially harmful areas in this island. The Estimated Background Values (EBV) of Cd, Co, Cr, Ni and V were found to be above the Canadian guidelines for any type of use of stream sediments and also above the target values of the Dutch and United States guidelines. The Probably Effect Concentrations (PEC), above which harmful effects are likely in sediment dwelling organisms, were found for Cr and Ni. Some associations between the geological formations of the island and the composition of stream sediments were identified and confirmed by descriptive statistics and by Principal Component Analysis (PCA). The EBV spatial distribution of the metals and the results of PCA allowed us to establish relationships between the EBV maps and the geological formations. The first two PCA modes indicate that heavy metals in Santiago stream sediments are mainly originated from weathering of underlying bedrocks. The first metal association (Co, V, Cr, and Mn; first PCA mode) consists of elements enriched in basic rocks and compatible elements. The second association of variables (Zn and Cd as opposed to Ni; second PCA mode) appears to be strongly controlled by the composition of alkaline volcanic rocks and pyroclastic rocks. So, the second PCA mode is also considered as a natural lithogenic mode. The third association (Cu and Pb; third PCA mode) consists of elements of anthropogenic origin

UTILIZAÇÃO DE EXPERIMENTOS ANALÓGICOS E SOFTWARES PARA AUXILIAR O PROCESSO ENSINO APRENDIZAGEM DO EFEITO FOTOELÉTRICO

The present work is an excerpt from the master's dissertation entitled: Didactic kit as a facilitating tool for the teaching-learning process of the photoelectric effect using the inverted classroom methodology presented in the National Professional Master's Degree in Physics Teaching (MNPEF) pole 19 of the Federal University of the South and Southeast of Pará (UNIFESSPA), as part of the necessary requirements to obtain the title of Master in Physics Teaching. The present research was applied in the ninth-grade classes of the Municipal School of Basic Education Ronilton Aridal da Silva Grilo in the Municipality of Canaã dos Carajás-PA. In this context, this work starts from the use of new technologies in the classroom, specifically robotic sensors to apply concepts related to the photoelectric effect as a tool to facilitate the teaching-learning process. Three analog experimentsO presente trabalho é um recorte da dissertação de mestrado intitulada: Kit didático como ferramenta facilitadora para o processo ensino aprendizagem do efeito fotoelétrico usando a metodologia de sala de aula invertida, apresentada no Mestrado Nacional Profissional em Ensino de Física (MNPEF), polo 19 da Universidade Federal do Sul e Sudeste do Pará (UNIFESSPA), como parte dos requisitos necessários à obtenção do título de Mestre em Ensino de Física. Aplicada nas turmas do nono ano da Escola Municipal de Ensino Básico Ronilton Aridal da Silva Grilo do Município de Canaã dos Carajás-PA, a presente pesquisa parte da utilização de novas tecnologias em sala de aula, especificamente, dos sensores robóticos para aplicação de conceitos relacionados ao efeito fotoelétrico, como ferramenta facilitadora do processo de ensino-aprendizagem. Nesse contexto, apresenta-se três experimentos analógicos (in loco) e dois softwares (virtuais), que podem ser utilizados por professores de ensino médio como suporte para aplicação e abordagem dos fenômenos de Física Moderna, sobretudo, o efeito fotoelétrico, fazendo uso das contribuições dos modelos de aprendizagem significativa de Ausubel e Moreira. Para tanto, a utilização dos experimentos analógicos e dos softwares mostra-se uma ferramenta potencialmente significativa no processo de ensino-aprendizagem de conteúdos que envolvem a Física Moderna

Didactic Sequence for Teaching Exponential Function

This paper presents a methodological proposal for the teaching of exponential function, resulting from the application of a didactic sequence involving exponential function, where evidence of learning and the consolidation and application of mathematical concepts in problem solving were identified and analyzed. The Didactic Engineering of Michèle Artigue (1988) was used as a research methodology. As theoretical contributions that guided and enabled the development of the research, we chose the use of Mathematical Investigation in the classroom; Didactic Sequence in the conception of Zabala (1999); the Articulated Units of Conceptual Reconstruction proposed by Cabral (2017) and assumptions of Vygotsky\u27s theory. A didactic sequence composed of five UARC\u27s was elaborated to work the exponential function, with a view to minimizing the difficulties naturally imposed by the content to be explained. Microgenetic analysis of verbal interactions between teacher and students was used to analyze the results of the application. The results show that the students participating in the experiment showed evidence of learning, recorded during the process, and began to have a good understanding of the concepts and properties related to the topic, in addition to a good performance in carrying out the activities, facts that corroborate the potential of the didactic sequence proposed herein

What's in a Sign? Trademark Law and Economic Theory

Abstract: The aim of this paper is to summarise the extant theory as it relates to the economics of trademark, and to give some suggestions for further research with reference to distinct streams of literature. The proposed line of study inevitably looks at the complex relationship between signs and economics. Trademark is a sign introduced to remedy a market failure. It facilitates purchase decisions by indicating the provenance of the goods, so that consumers can identify specific quality attributes deriving from their own, or others', past experience. Trademark holders, on their part, have an incentive to invest in quality because they will be able to reap the benefits in terms of reputation. In other words, trademark law becomes an economic device which, opportunely designed, can produce incentives for maximising market efficiency. This role must, of course, be recognised, as a vast body of literature has done, with its many positive economic consequences. Nevertheless, trademark appears to have additional economic effects that should be properly recognized: it can determine the promotion of market power and the emergence of rent-seeking behaviours. It gives birth to an idiosyncratic economics of signs where very strong protection tends to be assured, even though the welfare effects are as yet poorly understood. In this domain much remains to be done and the challenge to researchers is open

Incidence and mortality of ischemic stroke subtypes in Joinville, Brazil: a population-based study

Aims To measure the incidence and mortality rates of ischemic stroke (IS) subtypes in Joinville, Brazil. Methods All first-ever IS patients that occurred in Joinville from January 2005 to December 2006 were identified. The IS subtypes were classified by the TOAST criteria, and the patients were followed-up for one year after IS onset. Results The age-adjusted incidence per 100,000 inhabitants was 26 (17-39) for large-artery atherosclerosis (LAA), 17 (11-27) for cardioembolic (CE), 29 (20-41) for small vessel occlusion (SVO), 2 (0.6-7) for stroke of other determined etiology (OTH) and 30 (20-43) for stroke of undetermined etiology (UND). The 1-year mortality rate per 100,000 inhabitants was 5 (2-11) for LAA, 6 (3-13) for CE, 1 (0.1-6) for SVO, 0.2 (0-0.9) for OTH and 9 (4-17) for UND. Conclusion In the population of Joinville, the incidences of IS subtypes were similar to those found in other populations. These findings highlight the importance of better detection and control of atherosclerotic risk factors