Essays on corporate governance

Doutoramento em Gestão. Especialização em Finanças.Na presente dissertação são apresentados quatro ensaios sobre governo das sociedades. No primeiro ensaio é analisada a remuneração dos CEO das empresas cotadas portuguesas. Os resultados obtidos revelam que os fatores específicos das empresas explicam grande parte da variabilidade da remuneração total dos CEO, ao passo que o desempenho das empresas explica menos de 5%. Outras características do governo destas sociedades estão também relacionadas com a remuneração dos CEO. No segundo ensaio é analisada a relação entre o desempenho da empresa e o governo das sociedades, com especial enfoque nas características dos CEO, designadamente quanto ao nível e tipo de educação. Além da relação entre o governo das sociedades cotadas portuguesas e o seu desempenho, os resultados sugerem ainda que existe uma relação positiva entre o nível de educação dos CEO e o desempenho das empresas. No terceiro ensaio é analisado efeito da diversidade de género no conselho de administração na redução dos custos de agência. Os resultados empíricos suportam esta relação. Adicionalmente é encontrada evidência de que as empresas mais complexas e com maior preocupação acerca da independência dos seus dirigentes têm maior diversidade de género no conselho de administração. Por fim, no último ensaio é analisado o efeito da composição do conselho de administração na política de financiamento. Os resultados obtidos suportam a ideia de que conselhos de administração mais independentes reduzem a assimetria de informação, levando a uma maior utilização de fontes externas de capital tais como ações e dívida de longo prazo.This dissertation presents four empirical essays on corporate governance. The first essay analyses Portuguese CEO’s earnings. It is found that firm specific factors accounts for the majority of the variance in total CEO pay, while firm performance accounts for less than 5%. It is also found that the CEO characteristics, board of directors’ structures, and shareholders features are related with the CEO pay. In the second essay, we analyse the relationship between company performance and governance characteristics allowing for CEO specific characteristics, such as education, age and tenure. The findings support the conclusion that firm performance relates positively to the CEO’s level of educational attainment. Other governance-specific characteristics also explain this relationship, namely, the presence of independent directors on the board and voting cap restrictions. The third essay empirically analyses whether gender diversity enhances boards of directors’ independence and efficiency. The empirical results support this hypothesis. Moreover, this essay finds that firms that are concerned with board independence and those in more complex environments are more likely to have gender-balanced boards. Finally, the fourth essay empirically analyses the association between the board of directors’ composition and a firm’s financing policies. It is theorised that a more independent and efficient board leads to a shift of financing choices from retained earnings to short-term debt, from short-term debt to long-term debt, and from long-term debt to external equity financing. The results obtained in this last study support this hypothesis.N/

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Euronext stock exchange order book and order flow dynamics

Mestrado em Gestão/MBA in FinanceThe purpose of this study is twofold. First we analyze the intraday pattems of the Euronext Stock Exchange order book in terms of relative spread and depth at the best quotes. Then we test if the order flow aggressiveness is predisposed by the current state of the order book. The order book and order flow aggressiveness is analyzed using a data sample with more than 3 million order records across the 4 main national stock market places rnanaged by Euronext. We use the cross section regressions on a set of durnmy variables to analyze the intraday pattems of the order book and the order probit rnodel to study the interaction between the order flow aggressiveness and the current state of the order book. On the contrary to the current literature, the results obtained on the intraday pattems of the order book do not reveal a "U-Shape" but rather suggest that liquidity provision is larger and the relative spread is narrower by the end of the trading session and, thus, transaction costs are srnaller at this moment when compared with the beginning of the day. The trading activity is concentrated at the beginning and by the end of the trading day exhibiting a "waxing moon" shape. The tests held over the order flow aggressiveness given the state of the order book support the idea that traders are more concemed with depth at the sarne side of the book than to the opposite side. We find as well that traders tend to submit less aggressive orders when the transient volatility is smaller avoiding to be picked offby inforrned traders. Therefore, we provide new evidence that order aggressiveness is at least partially explained by the previous state of the order book in particular by the depth on the sarne side of the book and the transient volatility.Este estudo tem um duplo objectivo, primeiro pretende analisar o comportamento intra­ diário do livro de ofertas em termos de spread e profundidade nos melhores limites do livro de ordens. Segundo, pretende averiguar se a agressividade das ordens, medida através do posicionamento do seu preço face aos melhores preços oferecidos no mercado é explicado pelo estado actual do livro de ordens. No estudo é analisado o livro central de ofertas e a dinâmica das ordens introduzidas nas 4 praças nacionais da Euronext através de uma base de dados com mais de 3 milhões de ofertas introduzidas no sistema. Ao contrário da literatura recente sobre esta matéria não se encontrou evidencia de que o spread e a profundidade do livro de ordens tem um formato em U mas sim que a oferta de liquidez é maior e o spread relativo é mais estreito no final da sessão de negociação e, como tal, os custos de transacção são menores neste momento. A negociação está concentrada no início e no final da sessão exibindo um formato semelhante a uma "lua em quarto crescente". Os testes realizados sobre a agressividade das ordens sugerem que os investidores monitorizam o estado da profundidade do mercado. Contudo, preocupam-se mais com a profundidade do livro de ordens no mesmo lado da oferta do que com o lado oposto. Encontramos também evidência de que os investidores tendem a ser menos agressivos quando a volatilidade de curto prazo é maior evitando assim a negociação contra investidores mais informados. Conclui-se portanto que a agressividade das ordens é em parte explicada pelo estado actual do livro de ordens, particularmente pela profundidade do mercado na mesma ponta e pela volatilidade de curto prazo.N/

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data