Characterizing Geo-located Tweets in Brazilian Megacities

This work presents a framework for collecting, processing and mining geo-located tweets in order to extract meaningful and actionable knowledge in the context of smart cities. We collected and characterized more than 9M tweets from the two biggest cities in Brazil, Rio de Janeiro and S\~ao Paulo. We performed topic modeling using the Latent Dirichlet Allocation model to produce an unsupervised distribution of semantic topics over the stream of geo-located tweets as well as a distribution of words over those topics. We manually labeled and aggregated similar topics obtaining a total of 29 different topics across both cities. Results showed similarities in the majority of topics for both cities, reflecting similar interests and concerns among the population of Rio de Janeiro and S\~ao Paulo. Nevertheless, some specific topics are more predominant in one of the cities

The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus-3

Ubulin-binding domain (TBD) are represented as grey and black boxes, respectively. Schematic representation of the Pr55/Pr55BRET assay. This assay is used as a sensor of Pr55multimerization. 293T cells were transfected with constant amounts of pCMV-Pr55-luc and increasing amounts of pCMV-Pr55-YFP. A constant amount of a third plasmid expressing Stau1-HAor Stau1-HAwas included in the transfection procedure. luc activity as well as transmitted and total YFP activities was measured. BRET ratios were plotted in function of their corresponding total YFP/luc ratio which allows us to compare BRET ratios at the same relative expression levels of Pr55fusion proteins. This figure is representative of four independent experiments. Cells corresponding to the four last points of each curve from Figure 4B were lysed. Cell lysates were analyzed by Western blotting using anti (α)-HA antibodies for their content in over-expressed Stau1 proteins. *: Non-specific labelling typically obtained with the anti-HA antibody. BRET ratios were compared at comparable total YFP/luc ratio. The BRET ratio corresponding to the pr55fusions expressed alone was arbitrarily set to 1. The BRET induction levels were then determined and are shown in the graph. These results are representative of 4 experiments.<p><b>Copyright information:</b></p><p>Taken from "The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus"</p><p>http://www.retrovirology.com/content/5/1/41</p><p>Retrovirology 2008;5():41-41.</p><p>Published online 22 May 2008</p><p>PMCID:PMC2409373.</p><p></p

The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus-8

Tations were introduced in the basic region or in the zinc fingers of NC-p1-YFP fusion protein to generate four mutants. 293T cells were transfected with YFP, NC-p1-YFP and mutated NC-p1-YFP expressors. 48 hours post-transfection, cell lysates were prepared and analyzed by Western blotting using anti (α)-GFP antibodies.<p><b>Copyright information:</b></p><p>Taken from "The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus"</p><p>http://www.retrovirology.com/content/5/1/41</p><p>Retrovirology 2008;5():41-41.</p><p>Published online 22 May 2008</p><p>PMCID:PMC2409373.</p><p></p

The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus-4

P1-luc and Stau1-YFP expressors. 48 hours post-transfection, Stau1-YFP and Stau1-YFP contents in the cells were analyzed by Western blotting using anti (α)-GFP antibodies. 293T cells were transfected with constant amounts of CA-p2-NC-p1-Rluc-expressing plasmid and increasing amounts of wild-type or mutated YFP-fused Stau1 expressors. Twenty four hours post-transfection, live transfected cells were used for CA-p2-NC-p1/Stau1 BRET assays. BRET ratios are plotted in function of their corresponding total YFP/luc ratio. n = 4. BRET ratios were compared at identical total YFP/luc ratio and corrected by subtracting the background BRET ratio calculated for unfused YFP and CA-p2-NC-p1-luc co-expression. The corrected BRET ratio between CA-p2-NC-p1-luc and Stau1-YFP was arbitrarily set to 100%. n = 4. 293T cells were co-transfected with Pr55and wild-type or N-terminally truncated Stau1-Flag expressors. Twenty-four hours post-transfection, cell extracts were prepared and subjected to immunoprecipitation using anti-Flag antibodies. Cell lysates and immune complexes were analyzed by Western blotting using anti (α)-Flag and anti (α)-CA antibodies. Anti (α)-GAPDH antibodies were used as a loading control. n = 2.<p><b>Copyright information:</b></p><p>Taken from "The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus"</p><p>http://www.retrovirology.com/content/5/1/41</p><p>Retrovirology 2008;5():41-41.</p><p>Published online 22 May 2008</p><p>PMCID:PMC2409373.</p><p></p

The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus-6

Ach condition, an aliquot of the cells (providing equivalent total YFP/luc ratio) was used for Western blot analysis using anti (α)-HA and anti (α)-CA antibodies. Anti (α)-GAPDH antibody was used as a loading control. Another aliquot of the cells was used for BRET assays. Calculated BRET ratios were plotted as a function of the corresponding total YFP/luc ratio. Dose response pr55/pr55BRET assays. 293T cells were transfected with fixed amounts of pCMV-pr55-luc and pCMV-pr55-YFP and increasing amounts of different Stau1-HA expressors. 48 hours later, half of the cells were lysed and analyzed by Western blotting using anti (α)-HA and anti (α)-GAPDH antibodies. *: Non-specific labelling.The other half of the cells was used for BRET assays. BRET ratio is plotted as a function of the corresponding amount of transfected Stau1-HA expressor.<p><b>Copyright information:</b></p><p>Taken from "The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus"</p><p>http://www.retrovirology.com/content/5/1/41</p><p>Retrovirology 2008;5():41-41.</p><p>Published online 22 May 2008</p><p>PMCID:PMC2409373.</p><p></p

The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus-2

YFP-fused Gag proteins were expressed in 293T cells for twenty-four hours. VLPs in the cell supernatant were purified. Cell lysates and VLPs were analyzed by Western blotting using anti (α)-GFP antibodies. Anti (α)-GAPDH antibodies were used as loading controls. This figure is representative of three independent experiments. 293T cells were transfected with constant amounts of pCMV-Pr55-luc and increasing amounts of wild type or mutated YFP-fused Gag expressors. Twenty-four hours post-transfection, cells were collected and BRET ratios determined. BRET ratios are plotted in function of their corresponding total YFP/luc ratio. This figure is representative of three independent experiments.<p><b>Copyright information:</b></p><p>Taken from "The host protein Staufen1 interacts with the Pr55zinc fingers and regulates HIV-1 assembly via its N-terminus"</p><p>http://www.retrovirology.com/content/5/1/41</p><p>Retrovirology 2008;5():41-41.</p><p>Published online 22 May 2008</p><p>PMCID:PMC2409373.</p><p></p