1,245 research outputs found

    Where to put bike counters? Stratifying bicycling patterns in the city using crowdsourced data

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    This work was supported by a grant from the Public Health Agency of Canada to BikeMaps.org.When designing bicycle count programs, it can be difficult to know where to locate counters to generate a representative sample of bicycling ridership. Crowdsourced data on ridership has been shown to represent patterns of temporal ridership in dense urban areas. Here we use crowdsourced data and machine learning to categorize street segments into classes of temporal patterns of ridership. We used continuous signal processing to group 3,880 street segments in Ottawa, Ontario into six classes of temporal ridership that varied based on overall volume and daily patterns (commute vs non-commute). Transportation practitioners can use this data to strategically place counters across these strata to efficiently capture bicycling ridership counts that better represent the entire city.Publisher PDFPeer reviewe

    NEW SEISMIC SOURCE ZONE MODEL FOR PORTUGAL AND AZORES

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    The development of seismogenic source models is one of the first steps in seismic hazard assessment. In seismic hazard terminology, seismic source zones (SSZ) are polygons (or volumes) that delineate areas with homogeneous characteristics of seismicity. The importance of using knowledge on geology, seismicity and tectonics in the definition of source zones has been recognized for a long time [1]. However, the definition of SSZ tends to be subjective and controversial. Using SSZ based on broad geology, by spreading the seismicity clusters throughout the areal extent of a zone, provides a way to account for possible long-term non-stationary seismicity behavior [2,3]. This approach effectively increases seismicity rates in regions with no significant historical or instrumental seismicity, while decreasing seismicity rates in regions that display higher rates of seismicity. In contrast, the use of SSZ based on concentrations of seismicity or spatial smoothing results in stationary behavior [4]. In the FP7 Project SHARE (Seismic Hazard Harmonization in Europe), seismic hazard will be assessed with a logic tree approach that allows for three types of branches for seismicity models: a) smoothed seismicity, b) SSZ, c) SSZ and faults. In this context, a large-scale zonation model for use in the smoothed seismicity branch, and a new consensus SSZ model for Portugal and Azores have been developed. The new models were achieved with the participation of regional experts by combining and adapting existing models and incorporating new regional knowledge of the earthquake potential. The main criteria used for delineating the SSZ include distribution of seismicity, broad geological architecture, crustal characteristics (oceanic versus continental, tectonically active versus stable, etc.), historical catalogue completeness, and the characteristics of active or potentially-active faults. This model will be integrated into an Iberian model of SSZ to be used in the Project SHARE seismic hazard assessment

    Real-Word Effectiveness and Safety of Dimethyl Fumarate in a Multiple Sclerosis Portuguese Population

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    Objectives: The aim of this study was to evaluate postmarketing dimethyl fumarate (DMF) safety and effectiveness in a real-world population with relapsing-remitting multiple sclerosis (RRMS). Methods: This was a retrospective, single-center study with RRMS patients treated with DMF. Demographic, clinical, and imagiological characteristics were analyzed, including annualized relapse rate (ARR), Expanded Disability Status Scale, "No Evidence of Disease Activity 3," previous treatment, adverse events, treatment duration, and reason for discontinuation. We investigated which baseline variables were associated with clinical and radiological outcomes. Results: We included 176 patients (70.4% females) with a median on-treatment follow-up time of 25.5 months. In total, 139 patients received prior disease-modifying therapies, and 37 were treatment-naive. Annualized relapse rate decreased by 77.1% in the total population (P < 0.001) and also decreased in the naive, tolerability switch, and efficacy switch groups by 95.8%, 56.7%, and 76.6% (P < 0.001). No Evidence of Disease Activity 3 status after 12 months of DMF treatment was maintained in 69.2% patients. Thirty patients (17%) discontinued treatment because of adverse drug reactions, and 21 (11.9%) because of lack of effectiveness. The occurrence of first relapse during follow-up was associated with higher ARR in the year before DMF start (hazard ratio, 4.833; P < 0.001) and prior exposure to multiple sclerosis treatments (tolerability and efficacy switchers). Conclusions: In this real-world audit, DMF appeared to be effective and safe for RRMS. Additionally, the study suggested that naive patients strongly benefit from DMF, and DMF also improves ARR in patients who switched from injectable therapies due to tolerability and efficacy issues.info:eu-repo/semantics/publishedVersio

    O Bloqueio do Sistema Renina-Angiotensina-Aldosterona na Nefropatia Diabética

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    A nefropatia diabética é a primeira causa de insuficiência renal crónica nos Países Ocidentais. Na última década o bloqueio do sistema renina-angiotensina-aldosterona tem-se revelado particularmente útil na prevenção e na limitação da progressão da nefropatia diabética. O objectivo desta revisão é o de discutir os diversos níveis possíveis de intervenção neste sistema. Apresentam-se ainda as razões pelas quais defendemos o ratio urinário albumina:creatinina como o método preferencial para a determinação da excreção urinária de albumina..info:eu-repo/semantics/publishedVersio

    Serum C-X-C Motif Chemokine 13 is Elevated in Early and Established Rheumatoid Arthritis and Correlates with Rheumatoid Factor Levels

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    We hypothesized that serum levels of C-X-C motif chemokine 13 (CXCL13), a B-cell chemokine, would delineate a subset of rheumatoid arthritis (RA) patients characterized by increased humoral immunity

    COMPILATION OF ACTIVE FAULT DATA IN PORTUGAL FOR USE IN SEISMIC HAZARD ANALYSIS

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    To estimate where future earthquakes are likely to occur, it is essential to combine information about past earthquakes with knowledge about the location and seismogenic properties of active faults. For this reason, robust probabilistic seismic hazard analysis (PSHA) integrates seismicity and active fault data. Existing seismic hazard assessments for Portugal rely exclusively on seismicity data and do not incorporate data on active faults. Project SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded initiative (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are developing a fully-parameterized active fault database for Portugal that incorporates existing compilations, updated according to the most recent publications. The seismogenic source model derived for SHARE will be the first model for Portugal to include fault data and follow an internationally standardized approach. This model can be used to improve both seismic hazard and risk analyses and will be combined with the Spanish database for use in Iberian- and European-scale assessments

    Ca2+ Sparks and Embers of Mammalian Muscle. Properties of the Sources

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    Ca2+ sparks of membrane-permeabilized rat muscle cells were analyzed to derive properties of their sources. Most events identified in longitudinal confocal line scans looked like sparks, but 23% (1,000 out of 4,300) were followed by long-lasting embers. Some were preceded by embers, and 48 were “lone embers.” Average spatial width was ∼2 μm in the rat and 1.5 μm in frog events in analogous solutions. Amplitudes were 33% smaller and rise times 50% greater in the rat. Differences were highly significant. The greater spatial width was not a consequence of greater open time of the rat source, and was greatest at the shortest rise times, suggesting a wider Ca2+ source. In the rat, but not the frog, spark width was greater in scans transversal to the fiber axis. These features suggested that rat spark sources were elongated transversally. Ca2+ release was calculated in averages of sparks with long embers. Release current during the averaged ember started at 3 or 7 pA (depending on assumptions), whereas in lone embers it was 0.7 or 1.3 pA, which suggests that embers that trail sparks start with five open channels. Analysis of a spark with leading ember yielded a current ratio ranging from 37 to 160 in spark and ember, as if 37–160 channels opened in the spark. In simulations, 25–60 pA of Ca2+ current exiting a point source was required to reproduce frog sparks. 130 pA, exiting a cylindric source of 3 μm, qualitatively reproduced rat sparks. In conclusion, sparks of rat muscle require a greater current than frog sparks, exiting a source elongated transversally to the fiber axis, constituted by 35–260 channels. Not infrequently, a few of those remain open and produce the trailing ember

    A novel approach to measure the contribution of matrix metalloproteinase in the overall net proteolytic activity present in synovial fluids of patients with arthritis

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    Despite decades of research, only a very limited number of matrix metalloproteinase (MMP) inhibitors have been successful in clinical trials of arthritis. One of the central problems associated with this failure may be our inability to monitor the local activity of proteases in the joints since the integrity of the extracellular matrix results from an equilibrium between noncovalent, 1:1 stoichiometric binding of protease inhibitors to the catalytic site of the activated forms of the enzymes. In the present work, we have measured by flow cytometry the net proteolytic activity in synovial fluids (SF) collected from 95 patients with osteoarthritis and various forms of inflammatory arthritis, including rheumatoid arthritis, spondyloarthropathies, and chronic juvenile arthritis. We found that SF of patients with inflammatory arthritis had significantly higher levels of proteolytic activity than those of osteoarthritis patients. Moreover, the overall activity in inflammatory arthritis patients correlated positively with the number of infiltrated leukocytes and the serum level of C-reactive protein. No such correlations were found in osteoarthritis patients. Members of the MMP family contributed significantly to the proteolytic activity found in SF. Small-molecular-weight MMP inhibitors were indeed effective for inhibiting proteolytic activity in SF, but their effectiveness varied greatly among patients. Interestingly, the contribution of MMPs decreased in patients with very high proteolytic activity, and this was due both to a molar excess of tissue inhibitor of MMP-1 and to an increased contribution of other proteolytic enzymes. These results emphasize the diversity of the MMPs involved in arthritis and, from a clinical perspective, suggest an interesting alternative for testing the potential of new protease inhibitors for the treatment of arthritis
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