24,400 research outputs found
How to internalize congestion costs through a pricing scheme in the metropolitan area of madrid
Following the EU policy oriented to implement a tolling system based on social marginal costs, Spain is studying the implementation of an interurban road pricing scheme. In particular, a main result from the Spanish Road Pricing Model suggests that a road pricing scheme based on the congestion costs makes sense only in the reduced number of metropolitan highways and can be used to manage the travel demand in an urban and metropolitan context. In consequence, the analysis of this paper is focused on the results of the simulation of a toll-ring defined as a combined toll (access and distance toll based scheme) applied on the one of the more congested ring of the Madrid Metropolitan Area, the M40. The results are analyzed in terms of efficiency and equity criteria. Finally, the results of the implementation of a toll-ring pricing policy show a clear increasing level of socio-spatial inequalities. In fact, when the users have a viable road alternative, the burden of the toll-ring is equally distributed, if not, the burden of toll ring affects more the less wealthy people
Functional anatomy of non-REM sleep
The state of non-REM sleep (NREM), or slow wave sleep, is associated with a synchronized
EEG pattern in which sleep spindles and/or K complexes and high-voltage slow wave
activity (SWA) can be recorded over the entire cortical surface. In humans, NREM is subdivided
into stages 2 and 3â4 (presently named N3) depending on the proportions of each
of these polygraphic events. NREM is necessary for normal physical and intellectual performance
and behavior. An overview of the brain structures involved in NREM generation
shows that the thalamus and the cerebral cortex are absolutely necessary for the most
significant bioelectric and behavioral events of NREM to be expressed; other structures
like the basal forebrain, anterior hypothalamus, cerebellum, caudal brain stem, spinal cord
and peripheral nerves contribute to NREM regulation and modulation. In NREM stage 2,
sustained hyperpolarized membrane potential levels resulting from interaction between
thalamic reticular and projection neurons gives rise to spindle oscillations in the membrane
potential; the initiation and termination of individual spindle sequences depends on
corticothalamic activities. Cortical and thalamic mechanisms are also involved in the generation
of EEG delta SWA that appears in deep stage 3â4 (N3) NREM; the cortex has
classically been considered to be the structure that generates this activity, but delta oscillations
can also be generated in thalamocortical neurons. NREM is probably necessary to
normalize synapses to a sustainable basal condition that can ensure cellular homeostasis.
Sleep homeostasis depends not only on the duration of prior wakefulness but also on its
intensity, and sleep need increases when wakefulness is associated with learning. NREM
seems to ensure cell homeostasis by reducing the number of synaptic connections to a
basic level; based on simple energy demands, cerebral energy economizing during NREM
sleep is one of the prevalent hypotheses to explain NREM homeostasis.Grant BFU2009-06991/BFI from the Spanish Ministry of Science
and Innovation supported this wor
"Narco" Emotions: Affect and Desensitization in Social Media during the Mexican Drug War
Social media platforms have emerged as prominent information sharing
ecosystems in the context of a variety of recent crises, ranging from mass
emergencies, to wars and political conflicts. We study affective responses in
social media and how they might indicate desensitization to violence
experienced in communities embroiled in an armed conflict. Specifically, we
examine three established affect measures: negative affect, activation, and
dominance as observed on Twitter in relation to a number of statistics on
protracted violence in four major cities afflicted by the Mexican Drug War.
During a two year period (Aug 2010-Dec 2012), while violence was on the rise in
these regions, our findings show a decline in negative emotional expression as
well as a rise in emotional arousal and dominance in Twitter posts: aspects
known to be psychological markers of desensitization. We discuss the
implications of our work for behavioral health, facilitating rehabilitation
efforts in communities enmeshed in an acute and persistent urban warfare, and
the impact on civic engagement.Comment: Best paper award at the 32nd annual ACM conference on Human factors
in computing systems (CHI '14). ACM, New York, NY, USA, pages 3563-357
Biocatalysis as Useful Tool in Asymmetric Synthesis: An Assessment of Recently Granted Patents (2014â2019)
The broad interdisciplinary nature of biocatalysis fosters innovation, as different technical fields are interconnected and synergized. A way to depict that innovation is by conducting a survey on patent activities. This paper analyses the intellectual property activities of the last five years (2014â2019) with a specific focus on biocatalysis applied to asymmetric synthesis. Furthermore, to reflect the inventive and innovative steps, only patents that were granted during that period are considered. Patent searches using several keywords (e.g., enzyme names) have been conducted by using several patent engine servers (e.g., Espacenet, SciFinder, Google Patents), with focus on granted patents during the period 2014â2019. Around 200 granted patents have been identified, covering all enzyme types. The inventive pattern focuses on the protection of novel protein sequences, as well as on new substrates. In some other cases, combined processes, multi-step enzymatic reactions, as well as process conditions are the innovative basis. Both industries and academic groups are active in patenting. As a conclusion of this survey, we can assert that biocatalysis is increasingly recognized as a useful tool for asymmetric synthesis and being considered as an innovative option to build IP and protect synthetic routes
Strong Optomechanical Coupling at Room Temperature by Coherent Scattering
Quantum control of a system requires the manipulation of quantum states
faster than any decoherence rate. For mesoscopic systems, this has so far only
been reached by few cryogenic systems. An important milestone towards quantum
control is the so-called strong coupling regime, which in cavity optomechanics
corresponds to an optomechanical coupling strength larger than cavity decay
rate and mechanical damping. Here, we demonstrate the strong coupling regime at
room temperature between a levitated silica particle and a high finesse optical
cavity. Normal mode splitting is achieved by employing coherent scattering,
instead of directly driving the cavity. The coupling strength achieved here
approaches three times the cavity linewidth, crossing deep into the strong
coupling regime. Entering the strong coupling regime is an essential step
towards quantum control with mesoscopic objects at room temperature
Boundary stress tensor and asymptotically AdS3 non-Einstein spaces at the chiral point
Chiral gravity admits asymptotically AdS3 solutions that are not locally
equivalent to AdS3; meaning that solutions do exist which, while obeying the
strong boundary conditions usually imposed in General Relativity, happen not to
be Einstein spaces. In Topologically Massive Gravity (TMG), the existence of
non-Einstein solutions is particularly connected to the question about the role
played by complex saddle points in the Euclidean path integral. Consequently,
studying (the existence of) non-locally AdS3 solutions to chiral gravity is
relevant to understand the quantum theory. Here, we discuss a special family of
non-locally AdS3 solutions to chiral gravity. In particular, we show that such
solutions persist when one deforms the theory by adding the higher-curvature
terms of the so-called New Massive Gravity (NMG). Moreover, the addition of
higher-curvature terms to the gravity action introduces new non-locally AdS3
solutions that have no analogues in TMG. Both stationary and time-dependent,
axially symmetric solutions that asymptote AdS3 space without being locally
equivalent to it appear. Defining the boundary stress-tensor for the full
theory, we show that these non-Einstein geometries have associated vanishing
conserved charges.Comment: 8 pages. v2 minor typos correcte
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