Evidências de retornos anormais nos processos de IPO na Bovespa

The objective of this research was to detect anomalies in the pricing of shares in IPOs in the Brazilian capital market. The methodology of the event study for the measurement of possible abnormal stock returns resulting from temporal periods (daily, monthly, semi-annual and annual) for a total of 91 IPOs conducted from 2007 to 2013 was applied. The empirical results presented evidence about recovery in stock prices resulting from the first day of trading, it was found an abnormal return of the 2.82% above the Bovespa index on average, which indicates the Underpricing. The cumulative average abnormal returns, excluding the return on day 1, were not observed for the survey period, it is suggested that, after the first day of trading, shares tend to maintain a consistent behavior with the Bovespa. These figures show significant gains in the value of stocks analyzed within one day's supply, provided that the investor perform the first day of trading on the stock market, both in purely economic terms and in their own level of statistical significance. Moreover, it is not characterized by robustness, statistically relevant, the phenomenon of underperformance in the period.O objetivo da pesquisa foi detectar anomalias na precificação das ações nos processos de IPO no mercado de capitais brasileiro. A metodologia aplicada foi um estudo de evento para a mensuração de possíveis retornos anormais de ações, resultantes de períodos temporais (diário, mensal, semestral e anual) de um total de 91 IPOs, realizados entre 2007 e 2013. Os resultados empíricos apresentaram evidências de sobrevalorização nos preços das ações no primeiro dia de negociação, com retornos anormais de 2,82% acima do Ibovespa em média, o que indica o Underpricing. Os retornos anormais médios acumulados, excluído o 1° dia, não foram observados para o período da pesquisa, sugerindo que, após o primeiro dia de negociação, as ações mantiveram um comportamento coerente com o Ibovespa. Os números evidenciam relevantes ganhos de valor nas ações analisadas no período de um dia de oferta, desde que o investidor os realize no primeiro dia de negociação em bolsa, tanto em termos econômicos quanto em nível de significância estatística. Adicionalmente, não há evidências, com significância estatística, do fenômeno da Underperformance no período

Construction industry in the Czech Republic: The level of involvement in corporate social responsibility

This article introduces results of inquiry in corporate social responsibility conducted among construction companies in the Czech Republic in 2017. Its main themes include specifics of application of the CSR concept in the practice of the construction industry and effects of selected factors on the level of involvement of Czech construction companies in CSR activities. The results of the inquiry clearly indicate that despite the high level of knowledge of the CSR concept among the construction companies reaching 65 % the overall activities across the CSR pillars are scarce. The statistical test results show that large companies working with the concept of business ethics are more engaged in CSR activities. Growing size of the construction company is connected with activity increase in the social pillar. On the other hand, strategic planning hardly affects the company involvement in the CSR concept. Also the length of activity of the construction company on the market only affects CSR activity level within the environmental pillar.O

Infrared Properties of QCD from Dyson-Schwinger equations

I review recent results on the infrared properties of QCD from Dyson-Schwinger equations. The topics include infrared exponents of one-particle irreducible Green's functions, the fixed point behaviour of the running coupling at zero momentum, the pattern of dynamical quark mass generation and properties of light mesons.Comment: 47 pages, 19 figures, Topical Review to be published in J.Phys.G, v2: typos corrected and some references adde

Influence of Rock-Pool Characteristics on the Distribution and Abundance of Inter-Tidal Fishes

Rock pools can be found in inter-tidal marine environments worldwide; however, there have been few studies exploring what drives their, fish species composition, especially in Australia. The rock-pool environment is highly dynamic and offers a unique natural laboratory to study the habitat choices, physiological limitations and adaptations of inter-tidal fish species. In this study rock pools of the Sydney region were sampled to determine how the physical (volume, depth, rock cover and vertical position) and biological (algal cover and predator presence) parameters of pools influence fish distribution and abundance. A total of 27 fish species representing 14 families was observed in tide pools at the four study locations. The five most abundant species were Bathygobius cocosensis, Centropogon australis, Enneapterygius atrogulare, Lepidoblennius haplodactylus and Microcanthus strigatus, which together represented 71% of the total number of fish recorded. Larger rock pools containing more algal and rock ledge cover hosted a larger and more diverse population of fish. Furthermore, certain species were only found in pools with specific characteristics, such as the presence of loose shells, a variety algae or rock cover, suggesting a high degree of habitat specificity. By contrast, some species were ubiquitous and thus can likely tolerate a wide variety of physical conditions

Molecular biology of histidine decarboxylase and prostaglandin receptors

Histamine and prostaglandins (PGs) play a variety of physiological roles as autacoids, which function in the vicinity of their sources and maintain local homeostasis in the body. They stimulate target cells by acting on their specific receptors, which are coupled to trimeric G proteins. For the precise understanding of the physiological roles of histamine and PGs, it is necessary to clarify the molecular mechanisms involved in their synthesis as well as their receptor-mediated responses. We cloned the cDNAs for mouse l-histidine decarboxylase (HDC) and 6 mouse prostanoid receptors (4 PGE2 receptors, PGF receptor, and PGI receptor). We then characterized the expression patterns and functions of these genes. Furthermore, we established gene-targeted mouse strains for HDC and PG receptors to explore the novel pathophysiological roles of histamine and PGs. We have here summarized our research, which should contribute to progress in the molecular biology of HDC and PG receptors

Properties of Graphene: A Theoretical Perspective

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

Measurement of the rate of nu_e + d --> p + p + e^- interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory

Solar neutrinos from the decay of $^8$B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to nu_e's, while the ES reaction also has a small sensitivity to nu_mu's and nu_tau's. The flux of nu_e's from ^8B decay measured by the CC reaction rate is \phi^CC(nu_e) = 1.75 +/- 0.07 (stat)+0.12/-0.11 (sys.) +/- 0.05(theor) x 10^6 /cm^2 s. Assuming no flavor transformation, the flux inferred from the ES reaction rate is \phi^ES(nu_x) = 2.39+/-0.34 (stat.)+0.16}/-0.14 (sys) x 10^6 /cm^2 s. Comparison of \phi^CC(nu_e) to the Super-Kamiokande Collaboration's precision value of \phi^ES(\nu_x) yields a 3.3 sigma difference, providing evidence that there is a non-electron flavor active neutrino component in the solar flux. The total flux of active ^8B neutrinos is thus determined to be 5.44 +/-0.99 x 10^6/cm^2 s, in close agreement with the predictions of solar models.Comment: 6 pages (LaTex), 3 figures, submitted to Phys. Rev. Letter

ANAFILAXIA NA EMERGÊNCIA: REVISÃO DA LITERATURA

Introduction: Anaphylaxis corresponds to an acute systemic immune reaction that has a frequent rate in the emergency. In many cases, its evolution is unpredictable and serious, demanding better knowledge of this disease by professionals. Methodology: A literature review was carried out. Data collection was carried out in SCIELO and PUBMED using the following health descriptors: “Anaphylaxis; Diagnosis; Emergency; Epidemiology; Therapy". Results: We selected 19 articles published in English and Portuguese between the years 2012 and 2020. Anaphylaxis usually results from an immunological mechanism against different antigens exposed to a previously sensitized person. Its pathogenesis involves direct activation of mast cells, which promote the release of inflammatory mediators. Such substances trigger the abrupt onset of symptoms. During seizures, patients have symptoms that predominate in the integumentary and respiratory systems. Diagnosis is symptomatic. Therapeutic management must be quick to prevent severe complications and the drug of choice is adrenaline. The understanding of this condition is still outdated by some health professionals, which supports the ineffective clinical management of some patients as well as the higher occurrence of death. Conclusion: Anaphylaxis is a potentially fatal clinical condition that must be correctly managed in the emergency, to reduce the number of deaths. However, their insufficient knowledge by some doctors and access to adrenaline in the country make it difficult for this to happen.Introducción: La anafilaxia corresponde a una reacción inmunitaria sistémica aguda que tiene una frecuencia frecuente en la emergencia. En muchos casos, su evolución es impredecible y grave, exigiendo un mejor conocimiento de esta enfermedad por parte de los profesionales. Metodología: Se realizó una revisión de la literatura. La recolección de datos se realizó en SCIELO y PUBMED utilizando los siguientes descriptores de salud: “Anafilaxia; Diagnóstico; Emergencia; Epidemiología; Terapia". Resultados: Se seleccionaron 19 artículos publicados en inglés y portugués entre los años 2012 y 2020. La anafilaxia suele ser el resultado de un mecanismo inmunológico frente a diferentes antígenos expuestos a una persona previamente sensibilizada. Su patogenia implica la activación directa de mastocitos, que promueven la liberación de mediadores inflamatorios. Estas sustancias desencadenan la aparición repentina de síntomas. Durante las convulsiones, los pacientes tienen síntomas que predominan en los sistemas tegumentario y respiratorio. El diagnóstico es sintomático. El manejo terapéutico debe ser rápido para prevenir complicaciones graves y la droga de elección es la adrenalina. La comprensión de esta condición aún está desactualizada por algunos profesionales de la salud, lo que respalda el manejo clínico ineficaz de algunos pacientes, así como la mayor ocurrencia de muerte. Conclusión: La anafilaxia es una condición clínica potencialmente fatal que debe ser manejada correctamente en la sala de emergencias para reducir el número de muertes. Sin embargo, su conocimiento insuficiente por parte de algunos médicos y el acceso a la adrenalina en el país dificultan que esto suceda.Introdução: A anafilaxia corresponde a uma reação imunológica sistêmica aguda que apresenta uma taxa frequente na emergência. Em muitos casos, sua evolução é imprevisível e grave, demandando um melhor conhecimento dessa enfermidade pelos profissionais. Metodologia: Realizou-se uma revisão de literatura. A coleta de dados foi efetuada no SCIELO e no PUBMED com o uso dos descritores em saúde: “Anafilaxia; Diagnóstico; Emergência; Epidemiologia; Terapêutica”. Resultados: Selecionou-se 19 artigos publicados em inglês e em português entre os anos de 2012 e 2020. A anafilaxia geralmente decorre de um mecanismo imunológico contra diferentes antígenos expostos a uma pessoa previamente sensibilizada. Sua patogênese envolve a ativação direta dos mastócitos, que promovem a liberação de mediadores inflamatórios. Tais substâncias desencadeiam o início abrupto dos sintomas. Durante as crises, os pacientes apresentam sintomas predominantes nos sistemas tegumentar e respiratório. O diagnóstico é sintomatológico. O manejo terapêutico deve ser rápido para prevenir complicações severas e o fármaco de escolha é a adrenalina. A compreensão acerca dessa condição ainda está defasada por alguns profissionais de saúde, o que embasa a condução clínica ineficaz de alguns pacientes bem como a maior ocorrência de óbito. Conclusão: A anafilaxia é uma condição clínica potencialmente fatal que deve ser manejada corretamente na emergência, para reduzir o número de óbitos. Contudo, o seu insuficiente conhecimento por alguns médicos e acesso à adrenalina no país dificultam que isso ocorra

Os aspectos patogênicos do SARS-CoV-2 e as novas perspectivas terapêuticas contra a Covid-19: uma revisão integrativa da literatura / The pathogenic aspects of SARS-CoV-2 and the new therapeutic perspectives against Covid-19: an integrative literature review

Segundo a Organização Mundial da Saúde (OMS), em relação à COVID-19, o Brasil ocupa a terceira colocação no ranking mundial em termos de casos confirmados, e é o segundo país com o maior número absoluto de óbitos, atrás apenas dos Estados Unidos. Em todo o mundo, ocorreram mais de 3 milhões de mortes e, nesse contexto, além dos esforços voltados para a vacinação em massa, existe também uma corrida mundial por novos tratamentos. Desse modo, o presente estudo tem por objetivo reunir informações atualizadas acerca de terapias vistas como potencialmente eficazes no tratamento de pacientes com COVID-19. Realizou-se uma revisão de literatura integrativa sobre os aspectos estruturais e patogênicos do vírus SARS-CoV-2, bem como acerca das seguintes classes de fármacos: anticoagulantes, antiandrogênios e anticorpos monoclonais. Os estudos demonstraram resultados benéficos quanto a esses medicamentos. Contudo, as pesquisas apresentaram limitações quanto aos métodos, às doses implementadas e aos possíveis riscos envolvidos. Assim, é necessário que mais avaliações empíricas sejam realizadas para se demonstrar com maior exatidão as vantagens e desvantagens desses fármacos, a fim de proporcionar melhora significativa com efeitos colaterais mínimos e, possivelmente, garantir uma recuperação total desses pacientes

Predictors of dying at home for patients receiving nursing services in Japan: A retrospective study comparing cancer and non-cancer deaths

<p>Abstract</p> <p>Background</p> <p>The combined effects of the patient's and the family's preferences for death at home have in determining the actual site of death has not been fully investigated. We explored this issue on patients who had been receiving end-of-life care from Visiting Nurse Stations (VNS). In Japan, it has been the government's policy to promote end-of-life care at home by expanding the use of VNS services.</p> <p>Methods</p> <p>A retrospective national survey of a random sample of 2,000 out of the 5,224 VNS was made in January 2005. Questionnaires were mailed to VNS asking the respondents to fill in the questionnaire for each patient who had died either at home or at the hospital from July to December of 2004. Logistic regression analysis was respectively carried out to examine the factors related to dying at home for cancer and non-cancer patients.</p> <p>Results</p> <p>We obtained valid responses from 1,016 VNS (50.8%). The total number of patients who had died in the selected period was 4,175 (cancer: 1,664; non-cancer: 2,511). Compared to cancer patients, non-cancer patients were older and had more impairment in activities of daily living (ADL) and cognitive performance, and a longer duration of care. The factor having the greatest impact for dying at home was that of both the patient and the family expressing such preferences [cancer: OR (95% CI) = 57.00 (38.79-83.76); non-cancer: OR (95% CI) = 12.33 (9.51-15.99)]. The Odds ratio was greater compared with cases in which only the family had expressed such a preference and in which only the patient had expressed such a preference. ADL or cognitive impairment and the fact that their physician was based at a clinic, and not at a hospital, had modest effects on dying at home.</p> <p>Conclusions</p> <p>Dying at home was more likely when both the patient and the family had expressed such preferences, than when the patient alone or the family alone had done so, in both cancer and non-cancer patients. Health care professionals should try to elicit the patient's and family's preferences on where they would wish to die, following which they should then take appropriate measures to achieve this outcome.</p