Least-cost 100% renewable electricity scenarios

Renewable energy sources (RES) are becoming the main players for the sustainability of the planet and achieving a 100% RES energy system has been attested as a good strategy to go forward in many countries. This target however defies the system to integrate highly variable RES in a system that does not allow for shortage on the energy supply. This work presents a possible 100% RES scenario for an electricity system close to the Portuguese estimating and analysing the economic and technical impacts. The sensitivity of the results to aspects related to RES availability, electricity demand, peak load and interconnection capacity for electricity trading were also analysed. The results highlighted the excess of electricity produced in 100% RES systems and the importance of including interconnection capacity to contribute to overcome this problem.The authors wish to acknowledge the support of ALGORITMI research Centre at University of Minho. This work has been supported by COMPETE: POCI-OI-0145- FEDER-007043 and FCT - Funda<;iio para a Ciencia e Tecnologia within the Project Scope: UID/CEC/I00319/2013.info:eu-repo/semantics/publishedVersio

Multicriteria scenario analysis on electricity production

Energy planning is a complex process involving multiple and conflicting objectives with many agents able to influence decisions. This complexity is frequently addressed with the use of multicriteria tools, relying on a set of criteria and different methods to aggregate all the information in a final ranking of the available alternatives. This paper describes the application of a multicriteria decision tool for the analysis of Portuguese electricity scenarios. A set of criteria is proposed aiming to include social, economic, environmental and technical aspects. Criteria weighting was directly addressed considering 5 approaches: equitable weights, financial, technological, social and environmental perspectives. Results indicate that close to 100% RES scenario is the best option under a social perspective, base scenario represents the best option on a technical approach and scenarios relying on natural gas and wind power units are the best options for the electricity system under equitable weights, economic and environmental approaches.FCT - Fundação para a Ciência e a Tecnologia()The author wish to acknowledge the support of ALGORITMI, a research Centre at the University of Minho. This work is supported by National Funds through FCT - Foundation for Science and Technology, under the project PEst- OE/UID/CEC00319/2013.info:eu-repo/semantics/publishedVersio

Ecohydrology of temporary ponds

Temporary ponds (TP) comprise a complex ecohydrology and are extremely vulnerable to habitat degradation. These ecosystems contain species rarely found elsewhere but the environments are highly exposed to human and climate change pressures. TP have been recognised as priority habitats for conservation in Europe by the Habitats Directive, and work towards improved knowledge, understanding and conservation has increased since. This thesis focuses on the ecohydrological controls on the cladoceran species and communities in coastal temporary ponds in two geographic regions along a northwest Europe latitudinal gradient: the northwest coast of Ireland and the southwest coast of Portugal. It explores local time-variance in two dune slack ponds at Sheskinmore, Co. Donegal, Ireland, local spatial-variance across 24 ponds at the same site, and regional controls on temporary pond Cladocera ecohydrology at two sites in southwest Portugal (Malhão (MAL) and Vila do Bispo (VB)). The focus of investigation here is the seasonal hydrological balance and dependence of this dynamic on the ecology and biology of the habitats. This research aims to achieve a better understanding of individual, local and regional ecohydrological dynamics of TP’s and characterise the drivers of ecosystem variation within. Results uncover that ponds and slacks of Sheskinmore are highly dependent on rainfall and their vulnerability is confirmed when precipitation levels are not met. Increased variability inter-annually of cladocerans as opposed to intra-annual seasonal variation showed this. Weather changeability is the most important aspect of future climate change but there is a complex interaction between weather variability, local hydroregime and topography of a waterbody, impacting species’ temporal and spatial assemblages varyingly. Spatial dynamics of these dune ponds evaluated that within a rather small area, cladoceran composition differs, mainly according to hydrological categories, which are then linked to proximity of each site to the water table. Water chemistry was not so relevant to the spatial patterns in species. At a regional scale, sediment composition and water chemistry were better predictors of differentiation of the cladoceran composition within the Portuguese ponds, rather than geomorphological differentiations between regions. MAL ponds contained higher cladoceran abundance, whereas VB ponds contained higher cladoceran richness. Regionally, cladoceran communities are shaped by a combination of important factors and explanations vary according to the individual characteristics and to the collective groups of ponds. Results corroborate the importance of hydrology, topology and climatic factors as ecological drivers of ecosystem functioning in TP. This work demonstrates the uniqueness and sensitivity of TPs, therefore supporting the need to conserve these habitats

Impact of cervicovaginal microbiome on the risk of cervical abnormalities development

The vaginal microbiome has emerged as potentially influencing the natural history of Human Papillomavirus (HPV) infections and their clinical impact. We aimed to characterize the vaginal microbiome in samples from 807 high-risk HPVs (Hr-HPV) positive women with a mean age of 41.45 +/- 10.79 years who participated in the Regional Cervical Cancer Screening Program from the Northern Region of Portugal. Microbiome analysis was performed with commercial kits for the detection of 21 microorganisms. The most frequent microorganisms were Ureaplasma parvum (52.5%), Gardnerella vaginalis (GV) (34.5%), Atopobium vaginae (AV) (32.6%), Lacto (30.7%), and Mycoplasma hominis (MH) (23.5%). The distribution according to age reveals that MH, Mega1, GV, BVab2, AV, and Mob were more prevalent in women older than 41 years of age (p < 0.050), while Lacto is significantly decreased in this group (23.5% vs. 39.4%, p < 0.001; RR = 0.47). The risk analysis showed that Hr-HPV-16/-18 and Hr-HPV-9val genotypes are associated with an increased risk of developing cervical abnormalities, while Lacto (p < 0.001; odd ratio [OR] = 0.33), GV (p = 0.0111; OR = 0.41), AV (p = 0.033; OR = 0.53) and Mob (p = 0.022; OR = 0.29) are associated with protection. Similar results were found for the risk of development atypical squamous cells cannot exclude HSIL/high-grade squamous intraepithelial lesion. Overall, the multivariate analysis confirmed that lactobacillus and bacteria associated with bacterial vaginosis (GV, AV, and Mob) are associated with protection against the development of cervical abnormalities. This study provides important data to be included in the future management of risk stratification for Hr-HPV-positive women

Scenarios for the future Brazilian power sector based on a multi-criteria assessment

The Brazilian power generation sector faces a paradigm change driven by, on one hand, a shift from a hydropower dominated mix and, on the other hand, international goals for reducing greenhouse gas emissions. The objective of this work is to evaluate five scenarios for the Brazilian power sector until 2050 using a multi-criteria decision analysis tool. These scenarios include a baseline trend and low carbon policy scenarios based on carbon taxes and carbon emission limits. To support the applied methodology, a questionnaire was elaborated to integrate the perceptions of experts on the scenario evaluation process. Considering the results from multi-criteria analysis, scenario preference followed the order of increasing share of renewables in the power sector. The preferable option for the future Brazilian power sector is a scenario where wind and biomass have a major contribution. The robustness of the multi-criteria tool applied in this study was tested by a sensitivity analysis. This analysis demonstrated that, regardless of the respondents' preferences and backgrounds, scenarios with higher shares of fossil fuel sources are the least preferable option, while scenarios with major contributions from wind and biomass are the preferable option to supply electricity in Brazil through 2050.The research that allowed the publication of this paper has been produced with the financial assistance of the European Union in the context of the CLIMACAP project (EuropeAid/131944/C/SER/Multi) and of the U.S. Agency for International Development and U.S. Environmental Protection Agency in the context of the LAMP project (under Interagency Agreements DW89923040 and DW89923951US). The contents of this publication are the sole responsibility of the authors and can in no way be taken to reflect the views of the European Union or the U.S. government. The authors would like to thank the feedback and efforts from all CLIMACAP and LAMP project partners for enabling the research results reported in this article. This research was also supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under project NETEP-European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263).info:eu-repo/semantics/publishedVersio

A comunicação nas práticas de jovens professores de Matemática

Este artigo visa conhecer o modo como jovens professores, de diversos níveis de ensino, recém diplomados por instituições de formação inicial, orientam a comunicação nas suas aulas, a que aspectos tendem a dar atenção, que dificuldades sentem. Na sua base está um trabalho colectivo realizado por formadores de instituições de ensino superior em Portugal, preocupados em melhorar a qualidade da formação inicial dos professores em especial no que se refere à Didáctica da Matemática. A metodologia, de natureza qualitativa e interpretativa, envolveu a realização de 12 estudos de caso. Os resultados mostram que a comunicação é vista pelos jovens professores como um suporte de um ambiente geral que poderá favorecer, em termos globais a aprendizagem. No entanto, são relativamente poucos aqueles que identificam a comunicação como um objectivo curricular importante da disciplina de Matemática e que apontam estratégias consistentes para a promover, tanto na sua vertente oral como na sua vertente escrita. São ainda menos os apontam a comunicação como um processo fundamental para o desenvolvimento de significados matemáticos por parte dos alunos. Estes resultados sugerem que as instituiçõesThis article aims to know the way how new teachers, at several teaching levels, recently graduated by pre-service teacher education institutions view and conduct communication in their classrooms, to which aspects they tend to pay attention and which difficulties they feel. The paper is based on a collective work carried out by teacher educators of teacher education institutions in Portugal that are concerned in improving the quality of the preservice teacher education, especially in what refers to mathematics education. The methodology is qualitative and interpretative and involved the realization of 12 case studies. The results show that communication is seen by the new teachers as a support of a general environment that must favour learning. However, only relatively few teachers point out communication as an important curriculum objective in the discipline of mathematics and indicate consistent strategies to promote it, both in oral and written forms. There are still less teachers who view communication as a basic process for the development of mathematical meanings by students. These results suggest that teacher education institutions may have interest in reflecting about their teaching practices in this regard

The Zambian Macrophyte Trophic Ranking scheme, ZMTR:A new biomonitoring protocol to assess the trophic status of tropical southern African rivers

The Zambian Macrophyte Trophic Ranking system (ZMTR) is a new bioassessment scheme to indicate the trophic status of tropical southern African river systems. It was developed using a dataset of 218 samples of macrophytes and water chemistry, collected during 2009–2012, from river sites located in five world freshwater ecoregions primarily represented in Zambia. A typology based on these ecoregions, and three stream order categories, was used to determine soluble reactive phosphate (SRP) reference conditions. Zambian Trophic Ranking Scores (ZTRSsp) were calculated for 156 species, using direct allocation from SRP data for 80 species, in samples for which sufficient available SRP data existed. An indirect quantitative procedure, based upon occurrence of species in six sample-groups, of differing mean SRP status, produced by TWINSPAN classification, allocated provisional ZTRSsp values for the remaining 76 species. Additional data for nitrate, pH, alkalinity and conductivity were used to help assess the trophic preferences of macrophyte species showing differing ZTRSsp values. ZMTRsample values were calculated as the mean ZTRSsp score of species present per sample. ZMTR indicated trophic status reasonably accurately for 83.1% of Zambian samples, and for all samples within a test dataset from Botswanan rivers. Examples of application of the methodology, and its potential for hindcasting river trophic status are provided. The scheme currently underestimates highly-enriched conditions, and, to a lesser extent, overestimates the trophic status of some very low-nutrient rivers, but at this pilot stage of development it generally predicts the trophic status of tropical southern African river systems quite well

Environmental drivers of aquatic macrophyte communities in southern tropical African rivers:Zambia as a case study

The first-ever extensive macrophyte survey of Zambian rivers and associated floodplain waterbodies, conducted during 2006–2012, collected 271 samples from 228 sites, mainly located in five freshwater ecoregions of the world primarily represented in Zambia. The results supported the hypothesis that variation in macrophyte community structure (measured as species composition and diversity) in southern tropical African river systems, using Zambia as a case study area, is driven primarily by geographical variation in water physico-chemical conditions. In total, 335 macrophyte taxa were recorded, and a chronological cumulative species records curve for the dataset showed no sign of asymptoting: clearly many additional macrophyte species remain to be found in Zambian rivers. Emergent macrophytes were predominant (236 taxa), together with 26 floating and 73 submerged taxa. Several species were rare in a regional or international context, including two IUCN Red Data List species: Aponogeton rehmanii and Nymphaea divaricata. Ordination and classification analysis of the data found little evidence for temporal change in vegetation, at repeatedly-sampled sites, but strong evidence for the existence of seven groups of samples from geographically-varied study sites. These supported differing sets of vegetation (with eight species assemblages present in the sample-groups) and showed substantial inter-group differences in both macrophyte alpha-diversity, and geographically-varying physico-chemical parameters. The evidence suggested that the main environmental drivers of macrophyte community composition and diversity were altitude, stream order, shade, pH, alkalinity, NO3-N, and underwater light availability, while PO4-P showed slightly lower, but still significant variation between sample-groups

Síntese de 1,2-di-hidropiridinas

Mestrado em Química - Química Orgânica e Produtos NaturaisAs 1,2-di-hidropiridinas têm sido alvo de um crescente interesse ao longo dos últimos anos devido, fundamentalmente, à sua importância e versatilidade como intermediários sintéticos na obtenção de compostos heterocíclicos quirais, para os quais são conhecidas variadas e importantes atividades biológicas. O trabalho descrito nesta dissertação reporta o estudo da síntese de 1,2-dihidropiridinas segundo reações pericíclicas de aza-eletrociclização 6π de iminas α,β,γ,δ-di-insaturadas, obtidas por reação de condensação de (E,E)- cinamilidenoacetofenonas com aminas aromáticas primárias. Na primeira parte desta dissertação apresenta-se uma revisão bibliográfica sobre as propriedades e metodologias de síntese das 1,2-di-hidropiridinas. Na segunda parte encontram-se descritos os estudos que permitiram a obtenção destes compostos. Dois métodos de síntese das 1,2-di-hidropiridinas foram desenvolvidos. Um método direto de preparação das 1,2-dihidropiridinas recorrendo a radiação com micro-ondas e um segundo método que recorre à preparação da imina α,β,γ,δ-di-insaturada, intermediário fundamental nesta síntese, seguida de preparação da 1,2-di-hidropiridina quer por método clássico, quer por radiação com micro-ondas. A síntese de 1,2-di-hidropiridinas usando como substrato compostos cetónicos α,β,γ,δ-di-insaturados foi conseguida, apesar de todas as dificuldades enfrentadas no que se refere à sua instabilidade durante os procedimentos de purificação. Na caracterização estrutural dos compostos sintetizados recorreu-se a vários estudos de espectroscopia de ressonância magnética nuclear (RMN), os quais incluíram sobretudo o estudo de espectros de 1H, 13C, e estudos bidimensionais de correlação espectroscópica homo e heteronuclear.1,2-Dihydropyridines have been the subject of increasing interest over the last years, mainly due to its importance and versatility as synthetic intermediates in obtaining chiral heterocyclic compounds, which are known for various important biological activities. The work described in this thesis, reports the synthetic studies of 1,2- dihydropyridines based on pericyclic reactions of 6π-azaelectrocyclization involving α,β,γ,δ-diunsaturated imines, obtained by condensation of (E,E)- cinnamylideneacetophenones with primary aromatic amines. In the first part of this work, we present a bibliographic review concerning the properties and synthetic methodologies of 1,2-dihydropyridines. In the second part, we describe the studies that made possible to obtain these compounds. Two methods of synthesis of 1,2-dihydropyridines were developed. One direct method for the preparation of 1,2-dihydropyridines by microwave radiation, and a second one which relies on the preparation of the α,β,γ,δ-diunsaturated imine, an essential intermediate in this synthesis, followed by the preparation of the 1,2-dihydropyridine by both, the classic method or under microwave radiation. The synthesis of 1,2-dihydropyridines using as substrate α,β,γ,δ-diunsaturated carbonyl compounds was achieved, despite all the difficulties faced in what refers to its instability during the purifying procedures. All synthesized compounds were characterized recurring to exhaustive nuclear magnetic resonance (NMR) spectroscopic studies. The NMR methods used included 1H, 13C, two dimensional homonuclear (COSY) and heteronuclear correlation spectroscopy