5,143 research outputs found
The revanchist logic of mega-events: community displacement in Rio de Janeiro's West End
As the curtains are drawn in London's East End, Brazil and Rio de Janeiro will be under the international spotlight over the next four years. This paper focuses on the process of Olympic city-making in the West End of Rio de Janeiro, where the planning and construction of facilities and transport network have adversely affected low-income settlements. The planning of the Olympic Park has become the latest episode in a series of attempts to drive out one of the longest established poor settlements in the borough of Barra da Tijuca. Attention is given to the changing discourse justifying the relocation and the context in which residents have resisted eviction. In another case study, the paper considers the construction of Bus Rapid Transit corridors aimed to improve access to the area. In this instance, some communities were not able to avoid eviction, being relocated to the western edges of the city or financially compensated. Analysis of the eviction process is drawn from material collected by visiting the affected communities. The paper concludes by reflecting on the inexorability of Olympic city-making and entitlement to the emerging geographies
The involvement of girls and boys with bullying: an analysis of gender differences
This exploratory and cross-sectional study aimed to identify the prevalence of bullying in a group of students and analyze the data regarding the gender of those involved in the violence. A questionnaire adapted from Olweus was applied in seven elementary education schools in Portugal. The sample consisted of 387 students between 7 and 14 years old. Data are presented in terms of descriptive statistics and differences between proportions were analyzed using chi-square tests. The gender analysis of victimization and aggression shows that boys and girls are both victims and aggressors, and there are significant differences in involvement in bullying between genders and the roles played. Boys are victims more often when considering different types of bullying,
although significant differences were only found for physical aggression. Strategies that include gender roles are a priority for prevention and careful attention to this phenomenon in the school context. The questions addressed contribute to a broader understanding of the phenomenon, emphasizing the differential participation of boys and girls in bullying.CIEC – Research Centre on Child Studies, UM (FCT R&D 317
Coating of bioactive glasses with chitosan: The effects of the glass composition and coating method on the surface properties, including preliminary in vitro results
Two bioactive glasses were coated with chitosan: SCNB belongs to the SiO2-CaO-Na2O system, and SCNA has the addition of Al2O3 to enhance chemical stability. Different coating methods were compared: direct physical attachment, surface activation through tresyl chloride, and polydopamine as a linker. The samples were char-acterized through SEM-EDS, contact angle measurements, FTIR, zeta potential titrations, tape tests, in vitro precipitation of hydroxylapatite (bioactivity), and cell cultures (RAW 264.7 and UMR-106) on some selected samples. Direct physical attachment (in acetic acid) or use of polydopamine allowed complete surface coverage, while it dropped to one-quarter on both glasses by using tresyl chloride. The coating had a contact angle of about 80 degrees and it well showed typical functional groups (FTIR). The coatings on SCNA were chemically and mechan-ically stable (classified as 4-5B by the tape tests, partially maintained after soaking for 14 days), and showed an isoelectric point around 8. On SCNB, the coatings were unstable (classified as 0-3B, dissolved during soaking) but bioactivity was preserved. The coating affected the biological outcome of SCNA with M0/M1 polarization (1 day) and reduced viability of macrophages (3 days), while osteoblastic cells showed poor adhesion but maintained cell viability and osteogenic potential (3-7 days)
Microdevices for extensional rheometry of low viscosity elastic liquids : a review
Extensional flows and the underlying stability/instability mechanisms are of extreme relevance to the efficient operation of inkjet printing, coating processes and drug delivery systems, as well as for the generation of micro droplets. The development of an extensional rheometer to characterize the extensional properties of low viscosity fluids has therefore stimulated great interest of researchers, particularly in the last decade. Microfluidics has proven to be an extraordinary working platform and different configurations of potential extensional microrheometers have been proposed. In this review, we present an overview of several successful designs, together with a critical assessment of their capabilities and limitations
NETRA: Interactive Display for Estimating Refractive Errors and Focal Range
We introduce an interactive, portable, and inexpensive solution for estimating refractive errors in the human eye. While expensive optical devices for automatic estimation of refractive correction exist, our goal is to greatly simplify the mechanism by putting the human subject in the loop. Our solution is based on a high-resolution programmable display and combines inexpensive optical elements, interactive GUI, and computational reconstruction. The key idea is to interface a lenticular view-dependent display with the human eye in close range - a few millimeters apart. Via this platform, we create a new range of interactivity that is extremely sensitive to parameters of the human eye, like refractive errors, focal range, focusing speed, lens opacity, etc. We propose several simple optical setups, verify their accuracy, precision, and validate them in a user study.Alfred P. Sloan Foundation (Research Fellowship
Protein Co-Enrichment Analysis of Extracellular Vesicles
Extracellular Vesicles (EVs) carry cell-derived proteins that confer
functionality and selective cell uptake. However, whether proteins are packaged
stochastically or co-enriched within individual EVs, and whether co-enrichment
fluctuates under homeostasis and disease, has not been measured. EV abundance
and protein global relative expression have been qualified by bulk analysis.
Meanwhile, co-enrichment is not directly accessible via bulk measurement and
has not been reported for single EV analysis. Here, we introduce the normalized
index of co-enrichment (NICE) to measure protein co-enrichment. NICE was
derived by (i) capturing EVs based on the expression of a membrane-bound
protein, (ii) probing for the co-expression of a second protein at the
population level - EV integrity underwrites the detection of single EV
co-expression without the need to resolve single EVs - and (iii) normalizing
measured values using two universal normalization probes. Axiomatically, NICE =
1 for stochastic inclusion or no overall co-enrichment, while for positive and
negative co-enrichment NICE > 1 or < 1, respectively. We quantified the NICE of
tetraspanins, growth factor receptors and integrins in EVs of eight breast
cancer cell lines of varying metastatic potential and organotropism,
combinatorially mapping up to 104 protein pairs. Our analysis revealed protein
enrichment and co-expression patterns consistent with previous findings. For
the organotropic cell lines, most protein pairs were co-enriched on EVs, with
the majority of NICE values between 0.2 to 11.5, and extending from 0.037 to
80.4. Median NICE were either negative, neutral or positive depending on the
cells. NICE analysis is easily multiplexed and is compatible with microarrays,
bead-based and single EV assays. Additional studies are needed to deepen our
understanding of the potential and significance of NICE for research and
clinical uses
The Critical Behaviour of the Spin-3/2 Blume-Capel Model in Two Dimensions
The phase diagram of the spin-3/2 Blume-Capel model in two dimensions is
explored by conventional finite-size scaling, conformal invariance and Monte
Carlo simulations. The model in its -continuum Hamiltonian version is
also considered and compared with others spin-3/2 quantum chains. Our results
indicate that differently from the standard spin-1 Blume-Capel model there is
no multicritical point along the order-disorder transition line. This is in
qualitative agreement with mean field prediction but in disagreement with
previous approximate renormalization group calculations. We also presented new
results for the spin-1 Blume-Capel model.Comment: latex 18 pages, 4 figure
Visualizing intracardiac atrial fibrillation electrograms using spectral analysis
Atrial fibrillation is the most common cardiac arrhythmia, and it is associated with increased risk of stroke, heart failure, and mortality. This work describes spectral analysis techniques that are being used in conjunction with visualization algorithms to help guide catheter ablation procedures that aim at treating patients with arrhythmia
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