RESUMO
Ports link world commerce via maritime routes, and dredging services are essential to establish and maintain these connections. However, one question is critical when dredging is being considered: where are the best places to do it? To try to answer this question, a Dredging Sensitivity Index (DSI) was developed as a management tool to be used in project planning steps. In order to diminish environmental damages and quality-of-life losses, DSI provides alternatives by identifying sensitivity areas. This new methodology quantifies impacts caused by the sediment removal step and points out favorable areas to dredge, with a simple map. Parameters such as fine-grain content (% < 63 µm), Acid Volatile Sulfides (AVS), Shannon-Wiener Index and fisheries, among others, were used to calculate the DSI. Formulas were used to weight and aggregate both, the parameters and the DSI itself. Sepetiba Bay was chosen to apply this methodology because of its relevant economic and environmental aspects. The methodology was applied to dredging situations, but it can be used to indicate areas for dredged material disposal, with a few modifications in the DSI formulas. A DSI map was a final result of this methodology, and showed that the northern portion of the bay, close to the littoral is a more sensitive area, where dredging should be avoided, or carried out very carefully. DSI is a very useful tool for reducing damages from dredging services, it contributes with zonation and it provides alternatives to decision-makers who manage these areas.
RESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as coronavirus disease-2019 (COVID-19). SARS-CoV-2 infects the lungs and may cause several immune-related complications such as lymphocytopenia and cytokine storm which are associated with the severity of the disease and predict mortality . The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is not fully understood. Here we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS- CoV-2 in T helper cells in a mechanism that also requires ACE2 and TMPRSS2. Once inside T helper cells, SARS-CoV-2 assembles viral factories, impairs cell function and may cause cell death. SARS-CoV-2 infected T helper cells express higher amounts of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may explain the poor adaptive immune response of many COVID- 19 patients.
RESUMO
The present report deals with host distribution ectoparasites related to a col-lection of 1, 774 specimens captured on 51 wild rodentes and 3 marsupials, during three different periods from November 1987 to 19&9, in Maracá Island, Roraima State, Brazil. The number of ectoparasites found, as well as the sex ratio of the ectopanasites are presented. New host records are given for. A. fahrenholzi, G. goyanenis, L. flexa, L. paulistanensisand T. aymara.All the ectoparasites are, recorded for the first time in Roraima State. With the exception of Amblyommasp., Cummingsiasp. ,H. Aplendida, P. klagesi blagesi, P. blagesi samielisand Rhopalopsyllus australisssp., the otherspecies are recorded for. the fist time in Brazilian's Amazon. L. flexa, T. amazonicus, T. apicalis, T. aymaraand G. venezuelanusalso constitute new Brazilian records. Two new species of ectoparasites were also found: one acari and one biting lice.
Um levantamento de ectoparasitos de pequenos mamiferos foi realizado na ilha de Ma-racá, Roraima, Bnasil, durante três distintos periodos entre novembro de 1987 a fevereiro de 1989, tendo sido colecionados 1. 774 exemplares retirados de 51 roedores e 3 marsupiais. Os números e a distribuição por sexo das espécies de ectoparasitos encontrados são apresentados. Novos registros de hospedeiros são dados pana Androlaelaps fahrenhol zi, Gigantolaelaps goyanensis, Laelaps flexa, Laelaps paulistanensise Tur aymara.Todas as espécies de ectoparasiZos são registradas pela primeira vez no Estado de Rorai ma. Excetuando-se Amblyomma.sp., Cummingsiasp., Hoplopleura splendida, Polygenis kla-gesi klagesi, Polygenis klagesi samuelise Rhopalopsyllus australisssp. as demais espé-cies são assinaladas pela primeira vez na Amazônia brasileira. L. flexa, Tur amazonicus, Turapicalis, . aymanae Gliricola venezuelanustambém constituem novos negistros pora o Bnasil. Duas novas espécies de. ectoparasitos - uma de ácaro, outra de malófogo-foram, também, encontradas.
