International stock markets: Essays on the determinants and consequences of financial market development

This dissertation consists of three empirical papers about the determinants and consequences of financial market development in an international context. It aims to contribute to our understanding of the functioning of global financial markets. Each chapter provides evidence of a different issue related to a specific stage of financial market development. Chapter 2 provides an evaluation of the relative importance of structural and poli

Defense Strategies: The Role of Transcription Factors in Tomato–Pathogen Interaction

Tomato, one of the most cultivated and economically important vegetable crops throughout the world, is affected by a panoply of different pathogens that reduce yield and affect product quality. The study of tomato–pathogen system arises as an ideal system for better understanding the molecular mechanisms underlying disease resistance, offering an opportunity of improving yield and quality of the products. Among several genes already identified in tomato response to pathogens, we highlight those encoding the transcription factors (TFs). TFs act as transcriptional activators or repressors of gene expression and are involved in large-scale biological phenomena. They are key regulators of central components of plant innate immune system and basal defense in diverse biological processes, including defense responses to pathogens. Here, we present an overview of recent studies of tomato TFs regarding defense responses to biotic stresses. Hence, we focus on different families of TFs, selected for their abundance, importance, and availability of functionally well-characterized members in response to pathogen attack. Tomato TFs’ roles and possibilities related to their use for engineering pathogen resistance in tomato are presented. With this review, we intend to provide new insights into the regulation of tomato defense mechanisms against invading pathogens in view of plant breeding.This work was funded by the projects “Development of a new virus-based vector to control TSWV in tomato plants” with the references ALT20-03-0145-FEDER-028266 and PTDC/ASP-PLA/28266/2017, and “Control of olive anthracnose through gene silencing and gene expression using a plant virus vector” with the references ALT20-03-0145-FEDER-028263 and PTDC/ASP-PLA/28263/2017, co-financed by the European Union through the European Regional Development Fund, under the ALENTEJO 2020 (Regional Operational Program of the Alentejo), ALGARVE 2020 (Regional Operational Program of the Algarve) and through the Foundation for Science and Technology (FCT), in its national component. M.P. was supported by Portuguese National Funds through FCT/MCTES, under the PhD scholarship SFRH/BD/145321/2019, co-financed by the European Social Fund through the Regional Operational Program of the Alentejo. This work was also supported by National Funds through FCT under the Project UIDB/05183/2020

Tomato Response to Fusarium spp. Infection under Field Conditions: Study of Potential Genes Involved

Tomato is one of the most important horticultural crops in the world and is severely affected by Fusarium diseases. To successfully manage these diseases, new insights on the expression of plant– pathogen interaction genes involved in immunity responses to Fusarium spp. infection are required. The aim of this study was to assess the level of infection of Fusarium spp. in field tomato samples and to evaluate the differential expression of target genes involved in plant–pathogen interactions in groups presenting different infection levels. Our study was able to detect Fusarium spp. in 16 from a total of 20 samples, proving the effectiveness of the primer set designed in the ITS region for its detection, and allowed the identification of two main different species complexes: Fusarium oxysporum and Fusarium incarnatum-equiseti. Results demonstrated that the level of infection positively influenced the expression of the transcription factor WRKY41 and the CBEF (calcium-binding EF hand family protein) genes, involved in plant innate resistance to pathogens. To the best of our knowledge, this is the first time that the expression of tomato defense-related gene expression is studied in response to Fusarium infection under natural field conditions. We highlight the importance of these studies for the identification of candidate genes to incorporate new sources of resistance in tomato and achieve sustainable plant disease management.This research was supported by projects “Development of a new virus-based vector to control TSWV in tomato plants” with the references ALT20-03-0145-FEDER-028266 and PTDC/ASP-PLA/28266/2017, and “Control of olive anthracnose through gene silencing and gene ex- pression using a plant virus vector” with the references ALT20-03-0145-FEDER-028263 and PTDC/ASP- PLA/28263/2017, both projects co-financed by the European Union through the European Regional Development Fund, under the ALENTEJO 2020 (Regional Operational Program of the Alentejo), ALGARVE 2020 (Regional Operational Program of the Algarve) and through the Foundation for Science and Technology (FCT), in its national component. M.P. was supported by Portuguese National Funds through FCT/MCTES, under the PhD scholarship SFRH/BD/145321/2019, co-financed by the European Social Fund through the Regional Operational Program of the Alentejo. J.A.R. was supported by Portuguese National Funds through Project ALT20-03-0246-FEDER-000056, “BIOPRO- TOMATE: Bioproteção do tomateiro contra a fusariose—impacto das práticas agronómicas”, under scholarship BI_MESTRE_Uevora_CER_BIOPROTOMATE, co-financed by the European Regional Development Fund through Regional Operational Program Alentejo 2020

Recovery of bioactive compounds from Arbutus unedo L. fruits: Comparative optimization study of maceration/microwave/ultrasound extraction techniques

The aim of this work was to produce an extract rich in different bioactive compounds from Arbutus unedo L. fruits to enhance its possible valorization and commercialization. The conditions of the main variables of maceration, microwave, and ultrasound assisted extractions (MA, MAE and UAE, respectively) were optimized and compared in terms of its composition (based on the total material extracted, total content in carbohydrates, phenolic and flavonoid compounds) and its preservative potential (based on the response of four in vitro antioxidant assays). The key variables of each extraction technique (time, temperature or power and hydroalcoholic mixture) were evaluated by specific experimental designs using response surface methodology. Mathematical models were developed and numerical optimal values for each extraction technique and response were achieved. Regarding the extraction of target compositional compounds, MAE was the most efficient, closely followed by MA. In terms of its preservative potential, MAE was the most suitable solution, but MA gave similar results at lower temperatures (~90 °C). Globally, MA and MAE were the best options conducting to optimal solutions using reduced amounts of ethanol. UAE required higher ethanol contents (~60%). The results showed alternatives to obtain extracts of A. unedo fruits, supporting their potential to be exploited at industrial level.The authors thank the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E; and to the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE- 01-0145-FEDER-023289: DeCodE. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020 and FCT. To Xunta de Galicia for financial support for the post-doctoral researcher of M.A. Prieto. B. Albuquerque thanks Celeide Pereira (UTFPR, Brazil) for her master co-supervision. Finally, the authors want to express their gratitude to Araceli Menduiña Santomé (Instituto de Investigacións Mariñas, IIM-CSIC) for her professional work and dedication on the production of the laboratory results.info:eu-repo/semantics/publishedVersio

Axion-like particles as ultra high energy cosmic rays?

If Ultra High Energy Cosmic Rays (UHECRs) with E>4 10^{19} eV originate from BL Lacertae at cosmological distances as suggested by recent studies, the absence of the GZK cutoff can not be reconciled with Standard-Model particle properties. Axions would escape the GZK cutoff, but even the coherent conversion and back-conversion between photons and axions in large-scale magnetic fields is not enough to produce the required flux. However, one may construct models of other novel (pseudo)scalar neutral particles with properties that would allow for sufficient rates of particle production in the source and shower production in the atmosphere to explain the observations. As an explicit example for such particles we consider SUSY models with light sgoldstinos.Comment: 5 pages, 2 postscript figures, ref. adde

Metagenomic Assessment Unravels Fungal Microbiota Associated to Grapevine Trunk Diseases

Grapevine trunk diseases (GTDs) are among the most important problems that affect the longevity and productivity of vineyards in all the major growing regions of the world. They are slow-progression diseases caused by several wood-inhabiting fungi with similar life cycles and epidemiology. The simultaneous presence of multiple trunk pathogens in a single plant together with the inconsistent GTDs symptoms expression, their isolation in asymptomatic plants, and the absence of effective treatments make these diseases extremely complex to identify and eradicate. Aiming to gain a better knowledge of GTDs and search sustainable alternatives to limit their development, the present work studied the fungal community structure associated with GTDs symptomatic and asymptomatic grapevines, following a metagenomic approach. Two important cultivars from the Alentejo region with different levels of susceptibility to GTDs were selected, namely, ‘Alicante Bouschet’ and ‘Trincadeira’. Deep sequencing of fungal-directed ITS1 amplicon led to the detection of 258 taxa, including 10 fungi previously described as responsible for GTDs. Symptomatic plants exhibited a lower abundance of GTDs-associated fungi, although with significantly higher diversity of those pathogens. Our results demonstrated that trunk diseases symptoms are intensified by a set of multiple GTDs-associated fungi on the same plant. The composition of fungal endophytic communities was significantly different according to the symptomatology and it was not affected by the cultivar. This study opens new perspectives in the study of GTDs-associated fungi and their relation to the symptomatology in grapevines.This research was supported by Portuguese National Funds through FCT- MCTES under the PhD scholarship SFRH/BD/145321/2019, attributed to M.P., co-financed by the European Social Fund through the Regional Operational Program of the Alentejo. It was also supported by the project “Control of olive anthracnose through gene silencing and gene expression using a plant virus vector” (ALT20-03-0145-FEDER-028263 and PTDC/ASP-PLA/28263/2017) and by the project “Development of a new virus-based vector to control TSWV in tomato plants” (ALT20-03- 0145-FEDER-028266 and PTDC/ASP-PLA/28266/2017), both projects co-financed by the European Union through the European Regional Development Fund, under the Alentejo 2020, Algarve 2020 and through the FCT, in its national component

Nascent markets: Understanding the success and failure of new stock markets

We study the success and failure of 59 newly established (“nascent”) stock markets since 1975 in their first 40 years of activity. Nascent markets differ markedly in their success, as measured by number of listings, market capitalization, and trading activity. Long-term success is in part determined by early success: a high initial number of listings and trading activity are necessary, though not sufficient, conditions for long-term success. Banking sector development at the time of establishment and development of national savings over the life of the stock market are the other two most reliable predictors of success. We find little evidence that structural factors such as country size or legal and political institutions matter. Rather, our results point to an important role of banks, demand factors, and initial success in fostering long-term stock market development

Trypanocidal Activity Of Brazilian Plants Against Epimastigote Forms From Y And Bolivia Strains Of Trypanosoma Cruzi

Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 μg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.223528533Bastos, J.K., Albuquerque, S., Silva, M.L.A., Evaluation of the trypanocidal activity of lignans isolated from the leaves of Zanthoxylum naranjillo (1999) Planta Med, 65, pp. 1-4Batista Jr., J.M., Lopes, A.A., Ambrósio, D.L., Regasini, L.O., Kato, M.J., Bolzani, V.S., Cicarelli, R.M., Furlan, M., Natural chromenes and chromene derivatives as potencial antitrypanosomal agents (2008) Biol Pharm Bull, 31, pp. 538-540Botsaris, A., Plants used traditionally to treat malaria in Brazil: The archives of Flora Medicinal (2007) J Ethnobiol Ethnomed, 1, p. 18Buainain, A., Giazzi, J.F., Belda Neto, F.M., Martini, A.S., Rosa, J.A., Pozetti, G.L., Estudo da atividade de extratos vegetais sobre o desenvolvimento de Trypanosoma cruzi em meio líquido de Warren (1992) Rev Cien Farm, 14, pp. 93-102Cabral, M.M., Barbosa-Filho, J.M., Maia, G.L., Chaves, M.C., Braga, M.V., de Souza, W., Neolignans from plants in northeastern Brazil (Lauraceae) with activity against (2010) Trypanosoma Cruzi. Exp Parasitol, 124, pp. 319-324Costa-Lotufo, L.V., Silveira, E.R., Barros, M.C., Lima, M.A., de Moraes, M.E., de Moraes, M.O., Pessoa, C., Antiproliferative effects of abietane diterpenes from aegiphilla lhotzkyana (2004) Planta Med, 70, pp. 180-182Cotinguiba, F., Regasini, L.O., Bolzani, V.S., Debonsi, H.M., Passerini, D.O., Cicarelli, R.M.B., Kato, M.J., Furlan, M., Piperamides and their derivatives as potential antitrypanosomal agents (2009) Med Chem Res, 18, pp. 703-711Coura, J.R., Castro, S.L., A critical review on Chagas disease chemotherapy (2002) Mem I Oswaldo Cruz, 97, pp. 3-24Coura, J.R., Present situation and new strategies for Chagas disease chemotherapy: A proposal (2009) Mem I Oswaldo Cruz, 104, pp. 549-554Fernandes, O., Souto, R.P., Castro, J.A., Pereira, J.B., Fernandes, N.C., Junqueira, A.C., Naiff, R.D., Coura, J.R., Brazilian isolates of Trypanosoma cruzi from humans and triatomines classified into two lineages using mini-exon and ribosomal RNA sequences (1998) Am J Trop Med Hyg, 58, pp. 807-811Fournet, A., Ferreira, M.E., Rojas de Arias, A., Guy, I., Guinaudeau, H., Heinzen, H., Phytochemical and antiprotozoal activity of (2007) Ocotea Lancifolia. Fitoterapia, 78, pp. 382-384Lopes, A.A., López, S.N., Regasini, L.O., Batista, J.M., Ambrósio, D.L., Kato, M.J., da Silva, B.V., Furlan, M., In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi (2008) Nat Prod Res, 22, pp. 1040-1046Macedo, A.M., Oliveira, R.P., Pena, S.D.J., Chagas disease: Role of parasite genetic variation in pathogenesis (2002) Exp Mol Med, 4, pp. 1-16Muelas-Serrano, S., Nogal-Ruiz, J.J., Gómez-Barrio, A., Setting of a colorimetric method to determine the viability of Trypanosoma cruzi epimastigotes (2000) Parasitol Res, 86, pp. 999-1002Nwaka, S., Ridley, R.G., Virtual drug discovery and development for neglected diseases through publicprivate partnerships (2003) Nat Rev Drug Discov, 2, pp. 919-928Osorio, E., Arango, G.J., Jiménez, N., Alzate, F., Ruiz, G., Gutiérrez, D., Paco, M.A., Robledo, S., Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae (2007) J Ethnopharmacol, 111, pp. 630-635Regasini, L.O., Cotinguiba, F., Passerini, G.D., Bolzani, V.S., Cicarelli, R.M.B., Kato, M.J., Furlan, M., Trypanocidal activity of Piper arboreum and Piper tuberculatum (Piperaceae) (2009) Rev Bras Farmacog, 19, pp. 199-203Saraiva, J., Vega, C., Rolon, M., da Silva, R., Silva, M.L., Donate, P.M., Bastos, J.K., de Albuquerque, S., In vitro and in vivo activity of lignan lactones derivatives against Trypanosoma cruzi (2007) Parasitol Res, 100, pp. 791-795Tibayrenc, M., Ayala, F.J., The clonal theory of parasitic protozoa: 12 years on (2002) Trends Parasitol, 18, pp. 405-410(2010), http://www.who.int/mediacentre/factsheets/fs340/en/index.html, World Health Organization 2010, accessed in Au