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

Occurrence frequencies (%) of possible NoLS sequences (K/R-K/R-X-K/R) and of the twenty aminoacids at the X position in several NoLS-containing nucleolar proteins.

a<p>Among the eight possible sequence combinations (upper line), observed frequency (OF) of each aminoacid at the X position in NoLS present in 61 well-characterized nucleolar proteins and using for the analysis.</p>b<p>Mean frequency (MF) of each aminoacid observed in vertebrate proteins.</p

Subcellular localization of human eRF1 fused with short or long N-terminal sequence of Ilf3/NF90.

<p>Plasmids pCMV-heRF1-Ilf3/NF90 short N-terminal sequence (N-heRF1, mid panels) and pCMV-heRF1-Ilf3/NF90 long N-terminal sequence (NoLS-heRF1, lower panels) were transfected into HeLa cells. After 24 hours, untransfected (Control, upper panels) or transfected cells were co-stained with anti-heRF1 antibody (heRF1), anti-α-tubulin antibody (α-Tub) and DAPI. Endogenous heRF1 or heRF1 recombinant fusion proteins appear in green, α-tubulin in red and DAPI in blue. Arrows point to intranuclear foci corresponding to nucleoli.</p

Fluorescence recovery in HeLa cell nucleoli after photobleaching (FRAP) of GFP-tagged L-Ilf3, L-NF90 or B23.

<p>Plasmids pEGFP-N1-L-Ilf3, pEGFP-N1-L-NF90 or pEGFP-N1-B23 were transfected into HeLa cells. After 24 hours, living cells were subjected to photobleaching. A. In HeLa cells expressing L-NF90-GFP, one nucleolus was targeted for laser bleaching (left panel, green circle in the upper cell) whereas another nucleolus from the same cell (blue circle in the upper cell) and a nucleolus from a distinct cell (yellow circle in the lower cell) were marked to serve as controls. Images were acquired every two seconds during 40 seconds before, immediately after or during 240 seconds after bleaching (prebleach, bleach, post-bleach 6 and 240 seconds, respectively). B. Fluorescence recordings emitted from the 3 delimited regions in A (green: bleached nucleolus; purple: control nucleolus from the same cell; yellow: control nucleolus from another unbleached cell). C. Kinetics of mean fluorescence recovery after photobleaching of GFP-tagged L-Ilf3 (n = 14), L-NF90 (n = 15) or B23 (n = 11) after a normalization of fluorescence intensity. The t¹/₂ of mean fluorescence recovery are indicated in the figure.</p

Ilf3 and NF90 polymorphism in nuclear fractions purified from P19 cells.

<p>Ilf3 and NF90 from P19 cell nuclear fractions were submitted to 2-D PAGE and immunodetected with polyclonal antibody 78. Arrows positioned in the same coordinates in Ilf3 or NF90 panels indicate the positions of Ilf3 and NF90 long and short isoforms. The faint signal in the middle right panel was detected with a ten fold longer time exposure than that of the other panels.</p

Subcellular distribution of Ilf3 and NF90 in P19 cells.

<p>After subcellular fractionation, proteins from identical percentages of each fraction were submitted to SDS-PAGE, blotted onto nitrocellulose and immunodetected with the serum Ab78 raised against Ilf3 and NF90 (S.E.: short exposure time; L.E.: long exposure time), anti-UBF serum (UBF) or anti-α-tubulin antibody (α-tub.). Molecular weight markers (kDa) are indicated at the right.</p

Subcellular localization of GFP fused with the short or long N-terminal sequence of Ilf3/NF90.

<p>Plasmids pEGFP-N1 (Control, left panels), pEGFP-N1-Ilf3/NF90 common N-terminal short sequence (Short-GFP, mid panels) and pEGFP-N1-Ilf3/NF90 common N-terminal long sequence (Long-GFP, right panels) were transfected into HeLa cells. After 24 hours, cells were fixed and co-stained with anti-α-tubulin antibody (α-Tub) and DAPI. GFP or GFP fusion proteins appear in green, α-tubulin in red and DAPI staining in blue. Arrows point to intranuclear foci.</p

<i>In vitro</i> comparison of three common essential oils mosquito repellents as inhibitors of the Ross River virus - Fig 2

<p><b>Infectious capacity of RRV-T48</b> determined by plaque assay on infected Vero cells after pre-treatment of the viruses (1×10⁵ PFU) with the essential oils: <b>A:</b> residual infectivity; pre-treatment of the cells with the essential oils <b>B</b>: entry inhibition. Controls are infected cells and virus without treatment by the essential oils and values are expressed as mean ± SEM (n = 5).</p

<i>In vitro</i> comparison of three common essential oils mosquito repellents as inhibitors of the Ross River virus

<div><p>Background</p><p>The essential oils of <i>Cymbopogon citratus</i> (CC), <i>Pelargonium graveolens</i> (PG) and <i>Vetiveria zizanioides</i> (VZ) are commonly used topically to prevent mosquito bites and thus the risk of infection by their vectored pathogens such as arboviruses. However, since mosquito bites are not fully prevented, the effect of these products on the level of viral infection remains unknown.</p><p>Objectives</p><p>To evaluate <i>in vitro</i> the essentials oils from Reunion Island against one archetypal arbovirus, the Ross River virus (RRV), and investigate the viral cycle step that was impaired by these oils.</p><p>Methods</p><p>The essential oils were extracted by hydrodistillation and analyzed by a combination of GC-FID and GC×GC-TOF MS techniques. <i>In vitro</i> studies were performed on HEK293T cells to determine their cytotoxicity, their cytoprotective and virucidal capacities on RRV-T48 strain, and the level of their inhibitory effect on the viral replication and residual infectivity prior, during or following viral adsorption using the reporter virus RRV-<i>ren</i>Luc.</p><p>Results</p><p>Each essential oil was characterized by an accurate quantification of their terpenoid content. PG yielded the least-toxic extract (CC₅₀ > 1000 μg.mL^-1). For the RRV-T48 strain, the monoterpene-rich CC and PG essential oils reduced the cytopathic effect but did not display virucidal activity. The time-of-addition assay using the gene reporter RRV-<i>ren</i>Luc showed that the CC and PG essential oils significantly reduced viral replication and infectivity when applied prior, during and early after viral adsorption. Overall, no significant effect was observed for the low monoterpene-containing VZ essential oil.</p><p>Conclusion</p><p>The inhibitory profiles of the three essential oils suggest the high value of the monoterpene-rich essential oils from CC and PG against RRV infection. Combined with their repellent activity, the antiviral activity of the essential oils of CC and PG may provide a new option to control arboviral infection.</p></div

Time course of infection from RRV determined by plaque assay on infected Vero cells and luciferase activity on infected HEK293T cells.

<p>Results are expressed as a mean ± SEM (n = 5).</p