Risk of multiple sclerosis after optic neuritis in patients with normal baseline brain MRI

When assessing and managing a patient with optic neuritis (ON), the risk of future development of multiple sclerosis (MS) is an important issue, as this can be the first presentation of the disease. Although the presence of lesions on baseline brain MRI is the strongest predictor of MS conversion, some patients with normal imaging also develop MS. We aimed to estimate MS risk in patients with ON and a normal baseline MRI and identify individuals with higher risk of conversion. We performed a retrospective study including patients with idiopathic ON and normal baseline brain MRI who presented to our hospital over an 8year period. Of a total of 42 patients, 10 converted to MS: five during the first follow-up year, seven during the first 2years and all of the patients within the first 5years, with a 5year MS conversion rate of 23.8%. MS conversion rates were significantly higher in patients with history of previous symptoms suggestive of demyelination (p=0.002), cerebrospinal fluid oligoclonal bands unmatched in serum (p=0.004) and incomplete visual acuity recovery (⩽6/12) after 1year (p=0.002). Lower conversion rates were found in patients with optic disc edema (p=0.022). According to these results, a significant proportion of patients with idiopathic ON and a normal baseline brain MRI will develop MS, with a higher risk during the first 5years. Therefore, in the presence of factors in favor of MS conversion, close follow-up, including semestral medical consultations and yearly brain MRI, can be recommended. Early immunomodulatory treatment may be individually considered as it can delay conversion and reduce new lesion development rate

Emergência indígena e abertura da história no Baixo Tapajós

Este artigo propõe uma reflexão sobre a emergência do movimento indígena como sujeito coletivo nos últimos vinte anos (1998-2018) na região do Baixo Tapajós, Oeste do Estado do Pará. Busca-se compreender o processo de etnogênese em curso na região, no qual dezenas de comunidades, antes classificadas como ribeirinhas ou caboclas, passaram a assumir publicamente a identidade de povos indígenas, lutando pelo reconhecimento de direitos diferenciados, em especial a demarcação dos seus territórios. De igual forma, o artigo busca analisar o significado histórico e os desdobramentos produzidos por esse fenômeno, tomando como suporte teórico a noção de história aberta de Walter Benjamin. Chega-se, ao final, à conclusão de que a emergência indígena reabriu dossiês históricos fechados acerca da história do Baixo Tapajós e alterou profundamente o panorama da região, com a conquista de importantes direitos pelos povos indígenas, especialmente o direito à autodeterminação

Geological Characterization, Lithogeochemistry and the Metallogenic Potential for Chromium of the Riacho do Mocambo Mafic-Ultramafic Body, Northeast of the São Francisco Craton, BA, Brazil

In the geotectonic context of the Salvador-Curaçá Orogen, north portion of the São Francisco Craton, an association of mafic-ultramafic (M-UM) rocks was identified and described in this paper as the Riacho do Mocambo Mafic- Ultramafic Body (RMMUB). Despite being located approximately 60 km from the Vale do Jacurici Complex (VJC), the host of Brazil’s largest reserves of  Cr, the RMMUB has never been associated with this Complex in regional geologic mapping projects. When it is mentioned in the bibliography, the M- UM rocks of the RMMUB are genetically related to the São José do Jacuípe Suite (SJJS). While the VJC is described as differentiated sills, associated with a synorogenic to a tardi-orogenic event, the SJJS is interpreted as fragments of an Archean-Paleoproterozoic oceanic crust or as a Gabbro- Anorthosite Stratiform Complex. Such contrasting genesis raised doubts about the RMMUB’s origin and field work along with geochemical analyses were carried out in order to better understand the possible source of the RMMUB. In the field, the RMMUB exhibits an elongated shape of small thickness (7 km of extension by less than 100 m of apparent thickness), displayed concordantly with the Tanque Novo-Ipirá Complex metasediments. In the mapped outcrops it is possible to observe the rhythmic and gradual alternation amid the lithotypes of the RMMUB, varying from serpentinite to metagabbro, suggesting that it is a layered igneous body. The geochemical results support the primitive aspect of the ultramafic rocks of this body (MgO up to 38 wt.%; Ni up to 2972 ppm; Cr up to 7799 ppm) and suggest that the RMMUB shows distinctive characteristics from the SJJS, but similar ones with magma of the VJC such as geochemical signatures, source, depth, and tectonic environment. The discovery of this new M-UM body in an area of great metallogenic fertility opens a potential for the identification of new Cr mineralization and magmatic sulfides of Ni, Cu, and EGP, in the Salvador- Curaçá Orogen, São Francisco Craton, the northeast region of the state of Bahia

Context-aware music recommender system based on automatic detection of the user’s physical activity

[EN] The large amount of music that can be accessed in streaming nowadays has led to the development of more reliable music recommenda- tion systems. To this end, context-aware music recommendation systems, capable of suggesting music taking into account contextual information, have emerged. Studies have shown that music helps to improve mood while can change the focus of attention of users during the performance of some activity, helping to make this activity more bearable. This work presents a music Context Aware Recommender System in order to moti- vate users in their daily activities. Its main purpose is to suggest to the user the most appropriate music to improve the performance of the phys- ical activity at recommending time. The conducted experiments along a case study prove that this system is useful and satisfactory when the activity does not require a great deal of concentration. During activities that required movement, most users indicated that the perceived effort decreases when using the recommendation system proposed. They also indicated that their mood had improved after using this system. This demonstrates the usefulness of this recommender system while doing physical activities