704 research outputs found
Limited Ability to Activate Protein C Confers Left Atrial Endocardium A Thrombogenic Phenotype: A Role in Cardioembolic Stroke?
Background and Purpose—Atrial fibrillation is the most important risk factor for cardioembolic stroke. Thrombi form
in the left atrial appendage rather than in the right. The causes of this different thrombogenicity are not
well-understood. The goal herein was to compare the activation of the anticoagulant protein C and the
thrombomodulin and endothelial protein C receptor/activated protein C receptor expression on the endocardium
between right and left atria.
Methods—We harvested the atria of 6 monkeys (Macaca fascicularis) and quantified their ability to activate protein C ex
vivo and we measured the thrombomodulin and endothelial protein C receptor expression by immunofluorescence.
Results—We found the ability to activate protein C decreased by half (P 0.028) and there was lower expression of
thrombomodulin in the left atrial endocardium than the right (52.5 19.9 and 72.1 18.8 arbitrary intensity units,
mean standard deviation; P 0.028). No differences were detected in endothelial protein C receptor expression.
Conclusions—Impaired protein C activation on the left atrial endocardium attributable to low thrombomodulin expression
may explain its higher thrombogenicity and play a role in cardioembolic stroke
Characterizing Usage Patterns and Service Demand of a Two-Way Car-Sharing System
Urban mobility is directly linked to the demand for communication resources and, clearly, its understanding is useful for better planning of urban and communication systems. However, getting data about urban mobility is still a challenge. In many cases, only a few companies have access to accurate and updated data. In most cases, these data are also privacy sensitive. It is thus important to generate models that can help to understand mobility patterns. We here characterize the demands of a two-way car-sharing system. We explore data of the public API of Modo, a car-sharing system that operates in Vancouver (Canada) and nearby regions. Our study uncovers patterns of users’ habits and demands in the service, which can be explored for urban and communication planning
Paratransit: the need for a regulatory revolution in the light of institutional inertia
This chapter begins by defining what is traditionally meant by the term 'paratransit', before exploring why it has remained a relatively niche transport concern. Societal trends have shifted to a pattern of demand that is ill-suited to the system design for conventional public transport. Emerging IT applications offer the potential to introduce a new model of public transport appropriate to the travel needs of the 21st century. Paratransit modes are appealing because they could dynamically match the supply of a service with the level of demand required, unlike conventional models of public transport based on fading historical demand patterns.
But the regulatory environment for the local passenger sector has been built incrementally over many years around the institutional frameworks for buses and taxis. Paratransit alternatives often do not fully fit under any of these categorisations with the result that they often do not have an institutional home and thus either upset the status quo (as with Uber currently) or else are still born.
A redefinition of paratransit is proposed to facilitate a regulatory change to help address the institutional challenges of paratransit innovation
The nonlinear Schroedinger equation for the delta-comb potential: quasi-classical chaos and bifurcations of periodic stationary solutions
The nonlinear Schroedinger equation is studied for a periodic sequence of
delta-potentials (a delta-comb) or narrow Gaussian potentials. For the
delta-comb the time-independent nonlinear Schroedinger equation can be solved
analytically in terms of Jacobi elliptic functions and thus provides useful
insight into the features of nonlinear stationary states of periodic
potentials. Phenomena well-known from classical chaos are found, such as a
bifurcation of periodic stationary states and a transition to spatial chaos.
The relation of new features of nonlinear Bloch bands, such as looped and
period doubled bands, are analyzed in detail. An analytic expression for the
critical nonlinearity for the emergence of looped bands is derived. The results
for the delta-comb are generalized to a more realistic potential consisting of
a periodic sequence of narrow Gaussian peaks and the dynamical stability of
periodic solutions in a Gaussian comb is discussed.Comment: Enhanced and revised version, to appear in J. Nonlin. Math. Phy
Relationship between spatial proximity and travel-to-work distance : the effect of the compact city
In this paper, an assessment is made of the relationship between selected aspects of spatial proximity (density, diversity, minimum commuting distance, jobs-housing balance and job accessibility) and reported commuting distances in Flanders (Belgium). Results show that correlations may depend on the considered trip end. For example, a high residential density, a high degree of spatial diversity and a high level of job accessibility are all associated with a short commute by residents, while a high job density is associated with a long commute by employees. A jobs-housing balance close to one is associated with a short commute, both by residents and by employees. In general, it appears that the alleged sustainability benefits of the compact city model are still valid in a context of continuously expanding commuting trip lengths
Tendon Immune Regeneration: Insights on the Synergetic Role of Stem and Immune Cells during Tendon Regeneration
Tendon disorders represent a very common pathology in today’s population, and tendinopathies that account 30% of tendon-related injuries, affect yearly millions of people which in turn cause huge socioeconomic and health repercussions worldwide. Inflammation plays a prominent role in the development of tendon pathologies, and advances in understanding the underlying mechanisms during the inflammatory state have provided additional insights into its potential role in tendon dis-orders. Different cell compartments, in combination with secreted immune modulators, have shown to control and modulate the inflammatory response during tendinopathies. Stromal compartment represented by tenocytes has shown to display an important role in orchestrating the inflammatory response during tendon injuries due to the interplay they exhibit with the immune-sensing and infiltrating compartments, which belong to resident and recruited immune cells. The use of stem cells or their derived secretomes within the regenerative medicine field might represent synergic new therapeutical approaches that can be used to tune the reaction of immune cells within the damaged tissues. To this end, promising opportunities are headed to the stimulation of macrophages polarization towards anti-inflammatory phenotype together with the recruitment of stem cells, that possess immunomodulatory properties, able to infiltrate within the damaged tissues and improve tendinopathies resolution. Indeed, the comprehension of the interactions between tenocytes or stem cells with the immune cells might considerably modulate the immune reaction solving hence the inflammatory response and preventing fibrotic tissue formation. The purpose of this review is to compare the roles of distinct cell compartments during tendon homeostasis and injury. Furthermore, the role of immune cells in this field, as well as their interactions with stem cells and tenocytes during tendon regeneration, will be discussed to gain insights into new ways for dealing with tendinopathies
Understanding consumer demand for new transport technologies and services, and implications for the future of mobility
The transport sector is witnessing unprecedented levels of disruption.
Privately owned cars that operate on internal combustion engines have been the
dominant modes of passenger transport for much of the last century. However,
recent advances in transport technologies and services, such as the development
of autonomous vehicles, the emergence of shared mobility services, and the
commercialization of alternative fuel vehicle technologies, promise to
revolutionise how humans travel. The implications are profound: some have
predicted the end of private car dependent Western societies, others have
portended greater suburbanization than has ever been observed before. If
transport systems are to fulfil current and future needs of different
subpopulations, and satisfy short and long-term societal objectives, it is
imperative that we comprehend the many factors that shape individual behaviour.
This chapter introduces the technologies and services most likely to disrupt
prevailing practices in the transport sector. We review past studies that have
examined current and future demand for these new technologies and services, and
their likely short and long-term impacts on extant mobility patterns. We
conclude with a summary of what these new technologies and services might mean
for the future of mobility.Comment: 15 pages, 0 figures, book chapte
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