2,313 research outputs found
“Sidewalk” as a Realm of Users’ Interactions: simulating pedestrians’ densities at a commercial street in Cairo City
During the last four decades, researchers have developed many tools in order to investigate pedestrians’ behavior at sidewalks. Those tools tried to study sidewalks by investigating two main components: built environment and pedestrians’ movement. This paper presents a simulation for the pedestrians’ movement at a commercial street in Cairo, using an agent-based model. The model was designed in a way by which we could examine: pedestrians’ densities, the influence of types of uses on densities, the influence of flow-generators and destinations. In addition, we categorized the uses along the selected case of study by type of service and time spent by customer.
The method which we utilized for this work could be divided into two main phases: The first phase, included site video-based survey at different times and days, by which we could calculate flow rates at each generator point, and test the influence of uses on the density along the sidewalk. The second phase was to develop the model. In parallel, we focused on the uses’ types and how it affects controls pedestrians’ densities. Our results referred to a strong relation between use’s type and densities’ distribution along the street
Dielectric Properties of the Quasi-Two-Dimensional Electron Liquid in Heterojunctions
A quasi-two-dimensional (Q2D) electron liquid (EL) is formed at the interface
of a semiconductor heterojunction. For an accurate characterization of the Q2D
EL, many-body effects need to be taken into account beyond the random phase
approximation. In this theoretical work, the self-consistent static local-field
correction known as STLS is applied for the analysis of the Q2D EL. The
penetration of the charge distribution to the barrier-acting material is taken
into consideration through a variational approach. The Coulomb from factor that
describes the effective 2D interaction is rigorously treated. The longitudinal
dielectric function and the plasmon dispersion of the Q2D EL are presented for
a wide range of electron and ionized acceptor densities choosing GaAs/AlGaAs as
the physical system. Analytical expressions fitted to our results are also
supplied to enable a widespread use of these results.Comment: 39 pages (in LaTeX), including 8 PostScript figure
An individualized approach to sustained inflation duration at birth improves outcomes in newborn preterm lambs
A sustained first inflation (SI) at birth may aid lung liquid clearance and aeration, but the impact of SI duration relative to the volume-response of the lung is poorly understood. We compared three SI strategies: 1) variable duration defined by attaining volume equilibrium using real-time electrical impedance tomography (EIT; SIplat); 2) 30 s beyond equilibrium (SIlong); 3) short 30-s SI (SI30); and 4) positive pressure ventilation without SI (no-SI) on spatiotemporal aeration and ventilation (EIT), gas exchange, lung mechanics, and regional early markers of injury in preterm lambs. Fifty-nine fetal-instrumented lambs were ventilated for 60 min after applying the allocated first inflation strategy. At study completion molecular and histological markers of lung injury were analyzed. The time to SI volume equilibrium, and resultant volume, were highly variable; mean (SD) 55 (34) s, coefficient of variability 59%. SIplat and SIlong resulted in better lung mechanics, gas exchange and lower ventilator settings than both no-SI and SI30. At 60 min, alveolar-arterial difference in oxygen was a mean (95% confidence interval) 130 (13, 249) higher in SI30 vs. SIlong group (two-way ANOVA). These differences were due to better spatiotemporal aeration and tidal ventilation, although all groups showed redistribution of aeration towards the nondependent lung by 60 min. Histological lung injury scores mirrored spatiotemporal change in aeration and were greatest in SI30 group (P < 0.01, Kruskal-Wallis test). An individualized volume-response approach to SI was effective in optimizing aeration, homogeneous tidal ventilation, and respiratory outcomes, while an inadequate SI duration had no benefit over positive pressure ventilation alone
Cell therapy for spinal cord injury with Olfactory Ensheathing Glia Cells (OECs)
This is the peer reviewed version of the following article: Gómez RM, Sánchez MY, Portela-Lomba M, et al. Cell therapy for spinal cord injury with olfactoryensheathing glia cells (OECs). Glia. 2018;00:1–35
 which has been published in final form at GLIA 13 January (2018) http://doi.org/10.1002/glia.23282. © 2018 Wiley Periodicals This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The prospects of achieving regeneration in the central nervous system (CNS) have changed, asmost recent findings indicate that several species, including humans, can produce neurons in adult-hood. Studies targeting this property may be considered as potential therapeutic strategies torespond to injury or the effects of demyelinating diseases in the CNS. While CNS trauma mayinterrupt the axonal tracts that connect neurons with their targets, some neurons remain alive, asseen in optic nerve and spinal cord (SC) injuries (SCIs). The devastating consequences of SCIs aredue to the immediate and significant disruption of the ascending and descending spinal pathways,which result in varying degrees of motor and sensory impairment. Recent therapeutic studies forSCI have focused on cell transplantation in animal models, using cells capable of inducing axonregeneration like Schwann cells (SchCs), astrocytes, genetically modified fibroblasts and olfactoryensheathing glia cells (OECs). Nevertheless, and despite the improvements in such cell-based ther-apeutic strategies, there is still little information regarding the mechanisms underlying the successof transplantation and regarding any secondary effects. Therefore, further studies are needed to clarify these issues. In this review, we highlight the properties of OECs that make them suitable toachieve neuroplasticity/neuroregeneration in SCI. OECs can interact with the glial scar, stimulateangiogenesis, axon outgrowth and remyelination, improving functional outcomes following lesion.Furthermore, we present evidence of the utility of cell therapy with OECs to treat SCI, both fromanimal models and clinical studies performed on SCI patients, providing promising results for future treatments
Behavior of RC Wide Beams under Eccentric Loading
Wide beams are one of the widely used structural elements in RC buildings due to the many special features that characterize them. The main objective of this research is to investigate the behavior of wide shallow beams under the effect of eccentric loading acting along their cross sections. To achieve that, an experimental program that consisted of seven wide beams was conducted. All beams were loaded using two concentrated loads at their middle third where the main parameters considered were: the magnitude of the load eccentricity, the longitudinal spacing between shear reinforcement, and the arrangement of the longitudinal reinforcement. Following that, a finite element analysis was performed where the analytical model used was first verified using the data from the experimental program. The results from both the experimental and analytical programs were in good agreement. Then, the finite element analysis was extended through a parametric study where other variables were studies such as the compressive strength of concrete, the transverse spacing between stirrups and the longitudinal reinforcement ratio. The results showed that the value of the load eccentricity, spacing between shear reinforcement, the arrangement of the main reinforcement along the beam cross section, and the compressive strength of concrete significantly affected the torsional resistance of shallow wide beams. Conclusions and recommendations are presented which can be useful for future researchers. Doi: 10.28991/cej-2021-03091766 Full Text: PD
Trump vs. Hillary: What went Viral during the 2016 US Presidential Election
In this paper, we present quantitative and qualitative analysis of the top
retweeted tweets (viral tweets) pertaining to the US presidential elections
from September 1, 2016 to Election Day on November 8, 2016. For everyday, we
tagged the top 50 most retweeted tweets as supporting or attacking either
candidate or as neutral/irrelevant. Then we analyzed the tweets in each class
for: general trends and statistics; the most frequently used hashtags, terms,
and locations; the most retweeted accounts and tweets; and the most shared news
and links. In all we analyzed the 3,450 most viral tweets that grabbed the most
attention during the US election and were retweeted in total 26.3 million times
accounting over 40% of the total tweet volume pertaining to the US election in
the aforementioned period. Our analysis of the tweets highlights some of the
differences between the social media strategies of both candidates, the
penetration of their messages, and the potential effect of attacks on bothComment: Paper to appear in Springer SocInfo 201
Observation of charge asymmetry dependence of pion elliptic flow and the possible chiral magnetic wave in heavy-ion collisions
We present measurements of  and  elliptic flow, , at
midrapidity in Au+Au collisions at  200, 62.4, 39, 27,
19.6, 11.5 and 7.7 GeV, as a function of event-by-event charge asymmetry,
, based on data from the STAR experiment at RHIC. We find that 
() elliptic flow linearly increases (decreases) with charge asymmetry
for most centrality bins at  and higher.
At , the slope of the difference of
 between  and  as a function of  exhibits a
centrality dependence, which is qualitatively similar to calculations that
incorporate a chiral magnetic wave effect. Similar centrality dependence is
also observed at lower energies.Comment: 6 pages, 4 figure
Centrality and transverse momentum dependence of elliptic flow of multi-strange hadrons and meson in Au+Au collisions at = 200 GeV
We present high precision measurements of elliptic flow near midrapidity
() for multi-strange hadrons and  meson as a function of
centrality and transverse momentum in Au+Au collisions at center of mass energy
 200 GeV. We observe that the transverse momentum dependence of
 and   is similar to that of  and , respectively,
which may indicate that the heavier strange quark flows as strongly as the
lighter up and down quarks. This observation constitutes a clear piece of
evidence for the development of partonic collectivity in heavy-ion collisions
at the top RHIC energy. Number of constituent quark scaling is found to hold
within statistical uncertainty for both 0-30 and 30-80 collision
centrality. There is an indication of the breakdown of previously observed mass
ordering between  and proton  at low transverse momentum in the
0-30 centrality range, possibly indicating late hadronic interactions
affecting the proton .Comment: 7 pages and 4 figures, Accepted for publication in Physical Review
  Letter
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