2,894 research outputs found

    Travel and activity time allocation: An empirical comparison between eight cities in Europe

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    A study of daily time allocation to travel and out-of-home activity is conducted across eight European cities over three countries: France (Lyon, Grenoble, Strasbourg and Rennes), Switzerland (Geneva, Bern and Zurich) and Belgium (Brussels), based on individual travel survey data collected between 1997 and 2006. The effects of socio-demographic, spatial context, transport availability and city-specific variables are investigated thanks to the Cox proportional hazard model. The results indicate that socio-demographic characteristics and city (or country) specific effect play a major role while residential density and proximity to high level road or public transport networks have a very limited impact on time budgets for travel and out-of-home activities.Travel ; Activity ; Time allocation ; Cities ; Europe ; Duration model

    On Vertex- and Empty-Ply Proximity Drawings

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    We initiate the study of the vertex-ply of straight-line drawings, as a relaxation of the recently introduced ply number. Consider the disks centered at each vertex with radius equal to half the length of the longest edge incident to the vertex. The vertex-ply of a drawing is determined by the vertex covered by the maximum number of disks. The main motivation for considering this relaxation is to relate the concept of ply to proximity drawings. In fact, if we interpret the set of disks as proximity regions, a drawing with vertex-ply number 1 can be seen as a weak proximity drawing, which we call empty-ply drawing. We show non-trivial relationships between the ply number and the vertex-ply number. Then, we focus on empty-ply drawings, proving some properties and studying what classes of graphs admit such drawings. Finally, we prove a lower bound on the ply and the vertex-ply of planar drawings.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

    a meta-analysis of the 5-year efficacy and safety

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    Background The objective of this study was to compare the efficacy and safety of taxane (docetaxel or paclitaxel), cisplatin, and fluorouracil (Tax-PF) with cisplatin plus fluorouracil (PF) regimen by a meta-analysis of data retrieved from the literature. Methods Seven randomized clinical trials were identified, which included patients with advanced head and neck cancer who underwent induction chemotherapy with either a Tax-PF or PF protocol. The outcomes included the 3-year and 5-year overall survival (OS) and progression-free survival (PFS), overall response rate (ORR) and different types of adverse events. Results The 3-year OS rate (HR: 1.14; 95% CI: 1.03 to 1.25; P = 0.008), 3-year PFS rate (HR: 1.24; 95% CI: 1.08 to 1.43; P = 0.002), 5-year OS rate (HR: 1.30; 95% CI, 1.09 to 1.55;P = 0.003), 5-year PFS rate (HR: 1.39; 95% CI, 1.14 to 1.70; P = 0.001) and ORR to chemotherapy (OR 1.66; 95% CI, 1.35 to 2.05; P < 0.001) of the patients in the Tax-PF group were statistically superior to those in the PF group. In terms of toxicities, the incidence of febrile neutropenia (OR 2.36; 95% CI, 1.62 to 3.46; P < 0.001), alopecia (OR 8.22; 95% CI, 3.99 to 16.92; P < 0.001), diarrhea (OR 1.57; 95% CI, 1.05 to 2.36; P = 0.03) and leukopenia (OR 2.79; 95% CI, 1.86 to 4.21; P < 0.001) was higher in the Tax-PF group. Conclusion The Tax-PF induction chemotherapy improved PFS and OS, and the ORR was better as compared to PF- based therapy regimens at the cost of a higher incidence of adverse events

    Planar Drawings of Fixed-Mobile Bigraphs

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    A fixed-mobile bigraph G is a bipartite graph such that the vertices of one partition set are given with fixed positions in the plane and the mobile vertices of the other part, together with the edges, must be added to the drawing. We assume that G is planar and study the problem of finding, for a given k >= 0, a planar poly-line drawing of G with at most k bends per edge. In the most general case, we show NP-hardness. For k=0 and under additional constraints on the positions of the fixed or mobile vertices, we either prove that the problem is polynomial-time solvable or prove that it belongs to NP. Finally, we present a polynomial-time testing algorithm for a certain type of "layered" 1-bend drawings

    Perimovement decrease of alpha/beta oscillations in the human nucleus accumbens

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    The human nucleus accumbens is thought to play an important role in guiding future action selection via an evaluation of current action outcomes. Here we provide electrophysiological evidence for a more direct, i.e., online, role during action preparation. We recorded local field potentials from the nucleus accumbens in patients with epilepsy undergoing surgery for deep brain stimulation. We found a consistent decrease in the power of alpha/beta oscillations (10–30 Hz) before and around the time of movements. This perimovement alpha/beta desynchronization was observed in seven of eight patients and was present both before instructed movements in a serial reaction time task as well as before self-paced, deliberate choices in a decision making task. A similar beta decrease over sensorimotor cortex and in the subthalamic nucleus has been directly related to movement preparation and execution. Our results support the idea of a direct role of the human nucleus accumbens in action preparation and execution

    Credibility theory-based available transfer capability assessment

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    Since the development of large scale power grid interconnections and power markets, research on available transfer capability (ATC) has attracted great attention. The challenges for accurate assessment of ATC originate from the numerous uncertainties in electricity generation, transmission, distribution and utilization sectors. Power system uncertainties can be mainly described as two types: randomness and fuzziness. However, the traditional transmission reliability margin (TRM) approach only considers randomness. Based on credibility theory, this paper firstly built models of generators, transmission lines and loads according to their features of both randomness and fuzziness. Then a random fuzzy simulation is applied, along with a novel method proposed for ATC assessment, in which both randomness and fuzziness are considered. The bootstrap method and multi-core parallel computing technique are introduced to enhance the processing speed. By implementing simulation for the IEEE-30-bus system and a real-life system located in Northwest China, the viability of the models and the proposed method is verified

    Two types of martensitic phase transformations in magnetic shape memory alloys by in-situ nanoindentation studies

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    Ni based magnetic shape memory alloys (MSMAs) have broad applications in actuators and MEMS devices. Two-stage stress induced martensitic phase transformation, a widely observed phenomenon in these alloys, is described conventionally as a first stage L21 (austenite)-to-10M/14M (M: modulated martensite) transition, followed by a second stage 14M-to-L10 (tetragonal martensite) transformation at higher stresses. Here we show, for the first time via in-situ nanoindentation on single crystalline Ni54Fe19Ga27 alloy, that a reversible L21-to-10M/14M transformations took place at lower stress. However at higher stress, an irreversible transition from residual L21 to L10 martensite (a second type of phase transformation) occurred. Furthermore phase fronts propagate gradually during the L21-to-10M/14M transformation, whereas L10 is abruptly emitted in a jerky style during the 14M-to-L10 transformation. Detailed examination of crystal structure suggests that a direct transition from 14M to observed L10 is crystallographically forbidden in the current loading condition. This study provides new perspective for understanding of stress induced various types of phase transformations in MSMAs. This research is funded by NSF-CMMI under grant no. 1129065

    Reducing unscheduled hospital care for adults with diabetes following a hypoglycaemic event: which community-based interventions are most effective? A systematic review

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    AIM: To determine which community-based interventions are most effective at reducing unscheduled hospital care for hypoglycaemic events in adults with diabetes. METHODS: Medline Ovid, CINAHL Plus and ProQuest Health and Medical Collection were searched using both key search terms and medical subject heading terms (MeSH) to identify potentially relevant studies. Eligible studies were those that involved a community-based intervention to reduce unscheduled admissions in adults with diabetes. Papers were initially screened by the primary researcher and then a secondary reviewer. Relevant data were then extracted from papers that met the inclusion criteria. RESULTS: The search produced 2226 results, with 1360 duplicates. Of the remaining 866 papers, 198 were deemed appropriate based on titles, 90 were excluded following abstract review. A total of 108 full papers were screened with 19 full papers included in the review. The sample size of the 19 papers ranged from n = 25 to n = 104,000. The average ages within the studies ranged from 41 to 74 years with females comprising 57% of the participants. The following community-based interventions were identified that explored reducing unscheduled hospital care in people with diabetes; telemedicine, education, integrated care pathways, enhanced primary care and care management teams. CONCLUSIONS: This systematic review shows that a range of community-based interventions, requiring different levels of infrastructure, are effective in reducing unscheduled hospital care for hypoglycaemia in people with diabetes. Investment in effective community-based interventions such as integrated care and patient education must be a priority to shift the balance of care from secondary to primary care, thereby reducing hospital admissions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40200-021-00817-z

    Clinical risk factors and atherosclerotic plaque extent to define risk for major events in patients without obstructive coronary artery disease: the long-term coronary computed tomography angiography CONFIRM registry.

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    AimsIn patients without obstructive coronary artery disease (CAD), we examined the prognostic value of risk factors and atherosclerotic extent.Methods and resultsPatients from the long-term CONFIRM registry without prior CAD and without obstructive (≥50%) stenosis were included. Within the groups of normal coronary computed tomography angiography (CCTA) (N = 1849) and non-obstructive CAD (N = 1698), the prognostic value of traditional clinical risk factors and atherosclerotic extent (segment involvement score, SIS) was assessed with Cox models. Major adverse cardiac events (MACE) were defined as all-cause mortality, non-fatal myocardial infarction, or late revascularization. In total, 3547 patients were included (age 57.9 ± 12.1 years, 57.8% male), experiencing 460 MACE during 5.4 years of follow-up. Age, body mass index, hypertension, and diabetes were the clinical variables associated with increased MACE risk, but the magnitude of risk was higher for CCTA defined atherosclerotic extent; adjusted hazard ratio (HR) for SIS &gt;5 was 3.4 (95% confidence interval [CI] 2.3-4.9) while HR for diabetes and hypertension were 1.7 (95% CI 1.3-2.2) and 1.4 (95% CI 1.1-1.7), respectively. Exclusion of revascularization as endpoint did not modify the results. In normal CCTA, presence of ≥1 traditional risk factors did not worsen prognosis (log-rank P = 0.248), while it did in non-obstructive CAD (log-rank P = 0.025). Adjusted for SIS, hypertension and diabetes predicted MACE risk in non-obstructive CAD, while diabetes did not increase risk in absence of CAD (P-interaction = 0.004).ConclusionAmong patients without obstructive CAD, the extent of CAD provides more prognostic information for MACE than traditional cardiovascular risk factors. An interaction was observed between risk factors and CAD burden, suggesting synergistic effects of both
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