Enhancing and implementing a pairs trading strategy

This paper designs a pairs trading model with the intent to identify existing profitable market opportunities to invest, i.e. traditionally strong correlated stocks that have diverged from its historical norm. It comprises a broad literature review on this strategy whose relevant findings (strategy improvements) are contemplated in the model. The authors combine the statistical results of the model with a backtesting analysis in order to provide guidance on the best investment opportunities.NSBE - UN

Brazilian Female Labor Market: Racial-Skin Color Discrimination

O mito da democracia racial é ainda muito presente na sociedade brasileira, embora a literatura econômica aponte para a existência de umalto grau de discriminação racial. Este artigo visa inferir sua existência nos salários eficientes do mercado de trabalho feminino, levando-se em conta o problema do viés de seleção. As causas da ineficiência são também investigadas. Os resultados mostram que o diferencial de salário eficiente, não explicadas por diferenças no capital humano, é significativo, sendo maior entre as trabalhadoras mais eficientes. Por conseguinte, políticas tradicionais possuem apenas um efeito limitado para reduzir as diferenciais salariais entre raças.The myth of racial democracy is still widespread in the Brazilian society, although economic literature has continuously documented pervasive racial discrimination. This study analyzes racial discrimination in the Brazilian female labor market using a Mincer stochastic wage frontier, corrected for sample selection. The results, using Oaxaca-Blinder decomposition, showed that an efficient wage differential, not explained by differences in human capital does exist and is large among the most efficient workers. Wage inefficiencies are also explained and it is a claim of the study that traditional policies might be a tool in reducing underpayment dispersion, but cannot cope with pure discrimination

ESTRATÉGIAS PRODUTIVAS E APLICAÇÃO DE PRINCÍPIOS DA AGROECOLOGIA: o caso dos agricultores familiares de base ecológica da cooperativa dos agropecuaristas solidários de Itápolis - COAGROSOL

O artigo apresenta uma análise das estratégias produtivas de unidades certificadas de uma cooperativa de agricultores familiares de Itápolis (SP). Verificou-se nessas unidades a aplicação de princípios da agroecologia recomendados pela agricultura de base ecológica, em observância à agro-biodiversidade, à reciclagem de material e aos aspectos socioeconômicos do processo de conversão e transição agroecológica. A pesquisa desenvolveu-se por meio da complementaridade de abordagens proporcionada pela combinação de métodos de pesquisa sociológica e agronômica, com base na realiza-ção de entrevistas qualitativas e na aplicação de questionários com questões semiestruturadas. Con-cluiu-se que o estabelecimento de relações econômicas entre a cooperativa e uma entidade internacio-nal de comércio tem estimulado aumento expressivo na diversificação produtiva e na aplicação de princípios da agricultura de base ecológica, bem como proporcionado uma visível mudança de atitude quanto à exploração dos recursos naturais da região, localizada em uma das bacias hidrográficas mais degradadas do Estado de São Paulo em razão da poluição por agroquímicos e pesticidas e da ausência de matas nativas

Policies for a greener agriculture: the agro-ecological approach of current programs in Brazil.

Based a multiple-cases-study approach, our main objective is to discuss to what extent the new political approach of 2003 has been able so far to obtain and increase concrete progress in rural areas in Brazil

Determination of causal associations in occupational medicine and the medico-legal context: references and standards

Causality is a transdisciplinary topic with the medical-legal field representing one of its most exciting aspects. Since medicine and law have different roots and objectives, this article provides references to support occupational physicians and medico-legal experts in the difficult task of establishing occupational causation. In addition to the traditional Bradford Hill criteria and Schilling’s Classification, additional standards are provided to enhance critical assessment and contribute to the responsible use of the concept of causation in both the legal and medical-occupational fields

Acute onset of renal colic from bilateral ureterolithiasis: a case report

We report a case of a 32-year-old man, who presented to the emergency department with severe abdominal pain, with radiation to his back. An ultrasound examination revealed mild hydronephrosis bilaterally. A non-enhanced computer tomography was then performed and showed a 9 mm hyperdense image in the left ureter topography along together with an 8-mm hyperdense image in the right ureter topography, allowing us to establish the diagnosis of bilateral ureterolithiasis. The patient was taken to the operating room in order to perform ureteroscopy for endoscopic removal of the stones

Transport is important in the carbon footprint of imported organic plant products.

Farmers or consumers may ask about the environmental implications when choosing organic products. Is it sustainable to buy organic products from China or South America? How much does the long-distance transport affect the climate and carbon footprint of the products? And does the organic production in the countries concerned benefit the environment? These are some of the questions raised – and the point of departure for a recently finalized PhD study

OS ALIMENTOS TRANSGÊNICOS NA AGRICULTURA BRASILEIRA: EVOLUÇÃO E PERSPECTIVAS

The transgenic is a genetically modified organism or culture (OGM) that contains a gene that was artificially inserted, instead of having acquired naturally for pollination as they are for the conventional cultures. The “new agriculture “ based on this kind of products, points to a smaller degradation of the soils and of the environment, with reduction of the production costs and of the final prices for the consumer. Though your effects about the human health are still ignored and for that same reason, several restrictions to that type of food have been imposed. In that sense, this work sought to enlarge the discussion on that product type, discussing the possible environmental, economical and biological impacts of the transgenic use. The work is concluded discussing that this technology, with your potential of creating varieties of commercial cultures economically important, it is simply very valuable to be ignored. There is, however some concerns and valid subjects. For those subjects to be resolved with clarity, the decisions and analyses should be based in information with deep scientific rigor.transgenic food, agricultural productivity, agricultural, Agribusiness,

Modulation of an essential histone methyltransferase in mouse embryonic stem cells

The H3K9me3 is one of the major modifications characteristic of repressed chromatin. Its accumulation is linked to silencing of transcription and compaction of chromatin. Among the methyltransferases able to catalyze H3K9me3, SETDB1 leads to the earliest lethal phenotype in knockout mice embryos. In vitro studies showed that its interactor ATF7IP is capable of modulating SETDB1-dependent catalysis of H3K9me3. The implications of this interaction in a cellular system still remains an open question. Thus, to understand the modulation of SETDB1 methyltransferase activity during mouse early development was the main goal of this work. Using ChIP-Seq the genome-wide occupancy of both SETDB1 and ATF7IP was identified in FLAG knockin mouse embryonic stem cells (mESC). To investigate the epigenetic outcome of this interaction, the genome-wide enrichment for different H3K9 marks was characterized in control mESC and cells where Atf7ip was deleted by the CRISPR/Cas system. Afterwards, these data were coupled with transcriptome profiles to address whether the epigenetic changes implicated in transcriptional deregulation. In contrast to Setdb1 knockout mESC, cells lacking ATF7IP survive and grow normally. However, several families of endogenous retrovirus (ERV) belonging to classes I and II known to be controlled by SETDB1 were bound by both SETDB1 and ATF7IP and became derepressed in Atf7ip knockout mESC. This phenotype is further enhanced when cells are devoid of DNA methylation. Interestingly, while mutant cells are able to differentiate and repress repetitive sequences during differentiation as in control cells, DNA methylation-depleted mutant mESC could not properly repress those sequences. Unexpectedly, H3K9me3 levels in Atf7ip knockout mESC were reduced neither globally nor site specifically at transposable elements targets of SETDB1-ATF7IP complex. On the contrary, H3K9me3 deposition increased at those regions and was followed by increase in H3K9me2. To identify other proteins that might be involved in SETDB1-ATF7IP silencing mechanism mass spectrometry of FLAG-ATF7IP immune-complexes was performed. Then, taking advantage of an exogenous retrotransposon repression reporter system, which is impaired in Atf7ip-depleted mESC, ATF7IP partner proteins and other known repressors were screened for genetic interaction with Atf7ip. Some factors were found to act within the same pathway, while others had synergistic effects and probably belong to independent pathways. Lastly, exchanging the expression of the endogenous locus by that of different Atf7ip mutants by using a Bxb1-mediated recombination system demonstrated that nuclear localization, as well as the conserved Domains 1 and 2, are essential for proper ERV repression. Altogether, this work provides a better understanding of the molecular mechanism of repression by SETDB1 and its modulation by the co-factor ATF7IP