14 research outputs found
Neurophysiology in between the interests of Dom Pedro II of Brazil, and Charles Brown-Séquard
This article presents our historical research regarding Charles Brown-Séquard, a famous scientist with important contributions to the medical field, in particular for neurology, and endocrinology, and his relationship with Dom Pedro II, the second and last Brazilian Emperor, and an enlightened ruler. The Emperor contacted several illustrious personages in support of State policy, such as for the development of experimental physiology at the Imperial Museum of Natural History, but also for personal purposes given his health problems and those of the Empress. Charles Brown-Séquard and his pilgrimage between different worlds as a physician and physiologist are presented until his definitive establishment in Paris, where he replaces Claude Bernard in the chair of experimental medicine at the Collège de France. Jacques-Arsene d\u27Arsonval took over after this chair, and together with Brown-Séquard, he electrophysiologically examined the Emperor\u27s diabetic peripheral neuropathy. In this article, the Emperor´s relationship with BrownSéquard was studied mainly from the correspondence sent to Dom Pedro II and retrieved from the Imperial Museum in Petrópolis, Brazil, and from the accounts of his meetings that included scientific sessions and clinical consultations. This article can be used to understand the progress of knowledge in the field of neurology/clinical neurophysiology, the tracking of emerging ideas in the field of science in the past and the threat to the credibility of researchers
GOVERNANÇA CORPORATIVA E CRIAÇÃO DE VALOR EM AQUISIÇÕES
A literatura apresenta uma série de motivos para fusões e aquisições de empresas, que levariam a ganhos denominados genericamente de “sinergia”. Os mercados de capitais eficientes na forma semiforte perceberiam tais ganhos, o que elevaria o valor das empresas. Todavia, estudos empíricos indicam que, em média, os acionistas das empresas adquirentes experimentam retornos anormais nulos ou negativos, com elevada dispersão, quando tais transações são anunciadas. Uma possível explicação para tais resultados reside na possibilidade de algumas transações serem feitas por problemas de agência nas adquirentes. Em empresas com controle e propriedade pulverizados, executivos podem fazer tais transações em busca de benefícios para si, em detrimento dos acionistas. Na presença de benefícios privados do controle e da separação entre direitos de voto e direitos sobre fluxos de caixa, tal problema pode estar presente também em empresas com controle definido. Com base em tal arcabouço, este trabalho tem por objetivo investigar a relação entre qualidade da governança corporativa e o retorno anormal das adquirentes no Brasil, um mercado caracterizado pela presença de controladores que, muitas vezes, mantêm excesso de direitos de voto. Obtiveram-se evidências de relação positiva entre o retorno anormal das adquirentes e a listagem no Novo Mercado, segmento diferenciado de listagem superior da BM&FBovespa em que as empresas devem seguir a regra “uma ação – um voto
Non-Standard Errors
In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants
Do Bioreactor Designs with More Efficient Oxygen Supply to Ovarian Cortical Tissue Fragments Enhance Follicle Viability and Growth In Vitro?
Background: Autotransplantation of cryopreserved ovarian tissue is currently the main
option to preserve fertility for cancer patients. To avoid cancer cell reintroduction at transplantation,
amulti-step culture systemhas been proposed to obtain fully competent oocytes for in vitro fertilization.
Current in vitro systems are limited by the low number and health of secondary follicles produced
during the first step culture of ovarian tissue fragments. To overcome such limitations, bioreactor designs
have been proposed to enhance oxygen supply to the tissue, with inconsistent results. This retrospective
study investigates, on theoretical grounds, whether the lack of a rational design of the proposed
bioreactors prevented the full exploitation of follicle growth potential. Methods: Models describing
oxygen transport in bioreactors and tissue were developed and used to predict oxygen availability
inside ovarian tissue in the pertinent literature. Results: The proposed theoretical analysis suggests
that a successful outcome is associated with enhanced oxygen availability in the cultured tissue in the
considered bioreactor designs. This suggests that a rational approach to bioreactor design for ovarian
tissue culture in vitro may help exploit tissue potential to support follicle growth
Ensino de ciências e matemática II: temas sobre formação de conceitos
Coletânea de textos apresentados no Programa de Pós-Graduação em Educação para a Ciência, sediado na Faculdade de Ciências da UNESP, na área de ensino de Ciências e Matemática. O núcleo de pesquisa do Programa concentra-se em estudos sobre a ciência, a educação científica e nas relações entre o saber científico e seu ensino. Assim, incentiva a reflexão sobre os processos envolvidos na construção dos conhecimentos científicos e tecnológicos, além de contribuir para a produção de um corpo de conhecimentos filosóficos, científicos e pedagógicos destinados à formação de professores e outros profissionais da áre