Geographical versus Industrial Diversification: A Mean Variance Spanning Approach

This paper addresses whether country allocation provides benefits over industry allocation in a sample of European country and industry indexes. Strategy performance is compared using a mean-variance spanning test. We find that, for investors with low risk aversion, industry allocation is as good as investing in the complete set of assets. Moreover, in the most recent subperiod coinciding with the inception of the Euro, country and industry diversification are both effective. By contrast, investors with high risk aversion should always mix country and industry portfolios. A striking aspect of our analysis is that we do not find empirical evidence to support the argument that country diversification is a superior approach.Diversification gains, EMU, mean-variance spanning, portfolio allocation strategies

Stock Exchange Competition in a Simple Model of Capital Market Equilibrium

This paper uses a simple model of mean-variance asset pricing with transaction costs to analyze one of the main empirical phenomena in stock market competition in the last years, the decrease of transaction costs. We endogenize transaction costs as variables strategically influenced by stock exchanges and model stock market integration as an increase in the correlation of the underlying stock market returns. Among other things, we find that market integration leads to a decrease of transaction costs and to an increase in long-term trading activity.Stock Exchange Competition; Capital Markets Equilibrium; Transaction Costs

Competition Between Stock Exchanges: A Survey

This paper offers a systematized and updated view of competition between exchanges. It is divided in two parts: In the first part, we describe the recent reforms in stock exchanges and the main forces driving the development of competition. The second part surveys research done on stock exchanges.Stock Exchanges; Reforms; ECNs; Mergers; Demutualization; Cross-Listing

Risk factors in oil and gas industry returns: international evidence

This paper analyzes the exposure of the oil and gas industry of 34 countries to oil prices. Using a multifactor panel model to estimate the oil and gas excess stock returns, our results strongly support the view that oil price is a globally priced factor for the oil industry. In particular, the response of the oil and gas sector to changes oil prices is positive and larger for developed countries than for emerging markets. The industry response is asymmetric, with positive oil price changes having a greater impact on the oil sector returns than negative changes. Furthermore, local market index returns, currency rates and oil price volatility also have a significant impact on oil industry's excess returns. Finally, industry local sensitivities seem to vary with stock market activity and with levels of appropriation of industry revenues by governments. Results are robust to a battery of tests

Cysteine Boosts Fitness Under Hypoxia-Mimicked Conditions in Ovarian Cancer by Metabolic Reprogramming

Funding Information: Funding. This research was supported by Funda??o para a Ci?ncia e Tecnologia (FCT) (Ph.D. ProRegeM program, Ref: PD/BD/105893/2014; FCT individual Ph.D. fellowship Ref: 2020.06956.BD) and iNOVA4 Health (Project 4 and Project 21). iNOVA4Health-UID/Multi/04462/2013 is a program financially supported by Funda??o para a Ci?ncia e Tecnologia/ Minist?rio da Educa??o e Ci?ncia, through national funds. The authors would like to acknowledge the Instituto Portugu?s de Oncologia de Lisboa Francisco Gentil (IPOLFG) for partially funding the project. Publisher Copyright: © Copyright © 2021 Nunes, Ramos, Santos, Mendes, Silva, Vicente, Pereira, Félix, Gonçalves and Serpa.Among gynecologic malignancies, ovarian cancer is the third most prevalent and the most common cause of death, especially due to diagnosis at an advanced stage together with resistance to therapy. As a solid tumor grows, cancer cells in the microenvironment are exposed to regions of hypoxia, a selective pressure prompting tumor progression and chemoresistance. We have previously shown that cysteine contributes to the adaptation to this hypoxic microenvironment, but the mechanisms by which cysteine protects ovarian cancer cells from hypoxia-induced death are still to be unveiled. Herein, we hypothesized that cysteine contribution relies on cellular metabolism reprogramming and energy production, being cysteine itself a metabolic source. Our results strongly supported a role of xCT symporter in energy production that requires cysteine metabolism instead of hydrogen sulfide (H2S) per se. Cysteine degradation depends on the action of the H2S-synthesizing enzymes cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and/or 3-mercaptopyruvate sulfurtransferase (MpST; together with cysteine aminotransferase, CAT). In normoxia, CBS and CSE inhibition had a mild impact on cysteine-sustained ATP production, pointing out the relevance of CAT + MpST pathway. However, in hypoxia, the concomitant inhibition of CBS and CSE had a stronger impact on ATP synthesis, thus also supporting a role of their hydrogen sulfide and/or cysteine persulfide-synthesizing activity in this stressful condition. However, the relative contributions of each of these enzymes (CBS/CSE/MpST) on cysteine-derived ATP synthesis under hypoxia remains unclear, due to the lack of specific inhibitors. Strikingly, NMR analysis strongly supported a role of cysteine in the whole cellular metabolism rewiring under hypoxia. Additionally, the use of cysteine to supply biosynthesis and bioenergetics was reinforced, bringing cysteine to the plateau of a main carbon sources in cancer. Collectively, this work supports that sulfur and carbon metabolism reprogramming underlies the adaptation to hypoxic microenvironment promoted by cysteine in ovarian cancer.publishersversionpublishe

Gla-rich protein is involved in the cross-talk between calcification and inflammation in osteoarthritis

Osteoarthritis (OA) is a whole-joint disease characterized by articular cartilage loss, tissue inflammation, abnormal bone formation and extracellular matrix (ECM) mineralization. Disease-modifying treatments are not yet available and a better understanding of osteoarthritis pathophysiology should lead to the discovery of more effective treatments. Gla-rich protein (GRP) has been proposed to act as a mineralization inhibitor and was recently shown to be associated with OA in vivo. Here, we further investigated the association of GRP with OA mineralization-inflammation processes. Using a synoviocyte and chondrocyte OA cell system, we showed that GRP expression was up-regulated following cell differentiation throughout ECM calcification, and that inflammatory stimulation with IL-1 beta results in an increased expression of COX2 and MMP13 and up-regulation of GRP. Importantly, while treatment of articular cells with gamma-carboxylated GRP inhibited ECM calcification, treatment with either GRP or GRP-coated basic calcium phosphate (BCP) crystals resulted in the down-regulation of inflammatory cytokines and mediators of inflammation, independently of its gamma-carboxylation status. Our results strengthen the calcification inhibitory function of GRP and strongly suggest GRP as a novel anti-inflammatory agent, with potential beneficial effects on the main processes responsible for osteoarthritis progression. In conclusion, GRP is a strong candidate target to develop new therapeutic approaches

Polyurea Dendrimer Folate-Targeted Nanodelivery of l-Buthionine sulfoximine as a Tool to Tackle Ovarian Cancer Chemoresistance

The research was funded by iNOVA4Health—UID/Multi/04462/, a program financially supported by the Fundação para a Ciência e a Tecnologia—Ministério da Educação e Ciência (FCT-MCTES), through nationalfunds and co-funded by FEDER under the PT2020 Partnership Agreement. We also acknowledge funding from FCT-MCTES through the project DREAM—PTDC/MEC-ONC/29327/2017 and FAI2017 from IPOLFG internal funding.: Ovarian cancer is a highly lethal disease, mainly due to chemoresistance. Our previous studies on metabolic remodeling in ovarian cancer have supported that the reliance on glutathione (GSH) bioavailability is a main adaptive metabolic mechanism, also accounting for chemoresistance to conventional therapy based on platinum salts. In this study, we tested the effects of the in vitro inhibition of GSH synthesis on the restoration of ovarian cancer cells sensitivity to carboplatin. GSH synthesis was inhibited by exposing cells to l-buthionine sulfoximine (l-BSO), an inhibitor of -glutamylcysteine ligase (GCL). Given the systemic toxicity of l-BSO, we developed a new formulation using polyurea (PURE) dendrimers nanoparticles (l-BSO@PUREG4-FA2), targeting l-BSO delivery in a folate functionalized nanoparticle.publishersversionpublishe

Spent yeast waste streams as a sustainable source of bioactive peptides for skin applications

Spent yeast waste streams are a byproduct obtained from fermentation process and have been shown to be a rich secondary source of bioactive compounds such as phenolic compounds and peptides. The latter are of particular interest for skin care and cosmetics as they have been shown to be safe and hypoallergenic while simultaneously being able to exert various effects upon the epidermis modulating immune response and targeting skin metabolites, such as collagen production. As the potential of spent yeast’s peptides has been mainly explored for food-related applications, this work sought to understand if peptide fractions previously extracted from fermentation engineered spent yeast (Saccharomyces cerevisiae) waste streams possess biological potential for skin-related applications. To that end, cytotoxic effects on HaCat and HDFa cells and whether they were capable of exerting a positive effect upon the production of skin metabolites relevant for skin health, such as collagen, hyaluronic acid, fibronectin and elastin, were evaluated. The results showed that the peptide fractions assayed were not cytotoxic up to the highest concentration tested (500 µg/mL) for both cell lines tested. Furthermore, all peptide fractions showed a capacity to modulate the various target metabolites production with an overall positive effect being observed for the four fractions over the six selected targets (pro-collagen IαI, hyaluronic acid, fibronectin, cytokeratin-14, elastin, and aquaporin-9). Concerning the evaluated fractions, the overall best performance (Gpep > 1 kDa) was of an average promotion of 41.25% over the six metabolites and two cell lines assessed at a concentration of 100 µg/mL. These results showed that the peptide fractions assayed in this work have potential for future applications in skin-related products at relatively low concentrations, thus providing an alternative solution for one of the fermentation industry’s waste streams and creating a novel and highly valuable bioactive ingredient with encompassing activity to be applied in future skin care formulations.info:eu-repo/semantics/publishedVersio

Micropropagación de caña de azúcar en Ecuador

Ecuador is a country where sugar cane (Saccharum spp. hybrid) exceeds 82 000 ha for sugar production. The Research Center of the National Union of sugar cane farming in Ecuador (UNCE) is plotted as objective to obtain plants of different varieties by micropropagation, to multiply quickly and efficiently, genotypes with excellent performance under the conditions of production and result in a high quality certified seed and plant genetics. It were used as initial explants shoots, of the varieties ‘Cenicaña 1985-1992’ (CC85-92), ‘Ragnar’, ‘BJ 7046’, ‘CR 74-250’, ‘SP70-1143’, ‘PCG 12 745’ ‘RD7511’ and ‘Mexico 73-0523’. The obtained seedlings were multiplied, rooted and acclimatised. Then be planted in areas where sugar cane is grown in the country. In the case of the variety ‘Ragnar’ planted an area of approximately 0.3 ha, which was determined yield (ton/ha). Micropropagation of selected varieties allowed to obtain 268 600 plants in 12 months. It was found that the varieties showed differences in their rates of multiplication. The survival of plants in the acclimatization phase was higher than 88.0%. The harvest for the experimental plot planted with the variety ‘Ragnar’ contributed 55 tons. This equates to an output of 183 ton/ha. These values are much higher than the national average. The results confirmed the non-appearance of diseased plants or Scalding RSD. These results are one of the first reports for Ecuador from the use of biotechnological methods, being the pioneers in the mass propagation of sugarcane plants.Keywords: mass propagation, Saccharum spp. hybrid, seedEcuador es un país donde la caña de azúcar (Saccharum spp. híbrido) supera las 82 000 ha dedicadas a la producción de azúcar. El Centro de Investigación de la Unión Nacional de Cañicultores del Ecuador (UNCE) se trazó como objetivo obtener plantas de diferentes variedades por micropropagación, que permitiera multiplicar de manera rápida y eficaz, genotipos con excelente comportamiento en las condiciones de producción y que resultaran en una semilla certificada de alta calidad genética y fitosanitaria. Se emplearon como explantes iniciales meristemos apicales de las variedades ‘CeniCaña 85-92’ (CC85-92),‘Ragnar’, ‘BJ 7046’, ‘CR 74-250’, ‘SP70-1143’, ‘PCG 12745’, ‘RD7511’ y ‘México 73-0523’. Las plántulas obtenidas se multiplicaron, enraizaron y aclimatizaron. Posteriormente, se sembraron en áreas donde se cultiva caña de azúcar en el país. En el caso de la variedad ‘Ragnar’ se plantó un área de aproximadamente 0.3 ha, en la cual se determinó el rendimiento (t/ha). La micropropagación de las variedades seleccionadas permitió obtener 268 600 plantas en 12 meses. Se comprobó que las variedades mostraron diferencias en sus coeficientes de multiplicación. La supervivencia de las plantas en la fase de aclimatización fue superior al 88.0%. La cosecha correspondiente a la parcela experimental sembrada con la variedad ‘Ragnar’ aportó 55 t. esto equivale a una producción de 183 t/ha. Estos valores son muy superiores a la media nacional. Los resultados confirmaron la no aparición de plantas enfermas por RSD o Escaldadura. Estos resultados constituyen uno de los primeros informes para Ecuador de la utilización de métodos biotecnológicos, siendo los pioneros en la propagación masiva de plantas de caña de azúcar.Palabras clave: propagación masiva, Saccharum spp. híbrido, semill

Clonal expansion across the seas as seen through CPLP-TB database: A joint effort in cataloguing Mycobacterium tuberculosis genetic diversity in Portuguese-speaking countries

This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).Tuberculosis (TB) remains a major health problem within the Community of Portuguese Language Speaking Countries (CPLP). Despite the marked variation in TB incidence across its member-states and continued human migratory flux between countries, a considerable gap in the knowledge on the Mycobacterium tuberculosis population structure and strain circulation between the countries still exists. To address this, we have assembled and analysed the largest CPLP M. tuberculosis molecular and drug susceptibility dataset, comprised by a total of 1447 clinical isolates, including 423 multidrug-resistant isolates, from five CPLP countries. The data herein presented reinforces Latin American and Mediterranean (LAM) strains as the hallmark of M. tuberculosis populational structure in the CPLP coupled with country-specific differential prevalence of minor clades. Moreover, using high-resolution typing by 24-loci MIRU-VNTR, six cross-border genetic clusters were detected, thus supporting recent clonal expansion across the Lusophone space. To make this data available to the scientific community and public health authorities we developed CPLP-TB (available at http://cplp-tb.ff.ulisboa.pt), an online database coupled with web-based tools for exploratory data analysis. As a public health tool, it is expected to contribute to improved knowledge on the M. tuberculosis population structure and strain circulation within the CPLP, thus supporting the risk assessment of strain-specific trends.info:eu-repo/semantics/publishedVersio