87 research outputs found
Detecting phonon blockade with photons
Measuring the quantum dynamics of a mechanical system, when few phonons are
involved, remains a challenge. We show that a superconducting microwave
resonator linearly coupled to the mechanical mode constitutes a very powerful
probe for this scope. This new coupling can be much stronger than the usual
radiation pressure interaction by adjusting a gate voltage. We focus on the
detection of phonon blockade, showing that it can be observed by measuring the
statistics of the light in the cavity. The underlying reason is the formation
of an entangled state between the two resonators. Our scheme realizes a
phonotonic Josephson junction, giving rise to coherent oscillations between
phonons and photons as well as a self-trapping regime for a coupling smaller
than a critical value. The transition from the self-trapping to the oscillating
regime is also induced dynamically by dissipation.Comment: 6 pages, 5 figure
Photon production from the vacuum close to the super-radiant transition: When Casimir meets Kibble-Zurek
The dynamical Casimir effect (DCE) predicts the generation of photons from
the vacuum due to the parametric amplification of the quantum fluctuation of an
electromagnetic field\cite{casimir1,casimir2}. The verification of such effect
is still elusive in optical systems due to the very demanding requirements of
its experimental implementation. This typically requires very fast changes of
the boundary conditions of the problem, such as the high-frequency driving of
the positions of the mirrors of a cavity accommodating the field. Here, we show
that an ensemble of two-level atoms collectively coupled to the electromagnetic
field of a cavity (thus embodying the quantum Dicke model\cite{dicke}), driven
at low frequencies and close to a quantum phase transition, stimulates the
production of photons from the vacuum. This paves the way to an effective
simulation of the DCE through a mechanism that has recently found an
outstanding experimental demonstration\cite{esslinger}. The spectral properties
of the emitted radiation reflect the critical nature of the system and allow us
to link the detection of DCE to the Kibble-Zurek mechanism for the production
of defects when crossing a continuous phase transition\cite{KZ1,KZ2}. We
illustrate the features of our proposal by addressing a simple cavity
quantum-electrodynamics (cQED) setting of immediate experimental realisation.Comment: 4+1 pages, major changes in the second part of the paper. To appear
in Physical Review Letter
Long Term Ecological Research (LTER) in the Marine Coastal Environment: Basic Concepts and Keystones from the Plankton Communities.
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Influence of a high‐impact multidimensional rehabilitation program on the gut microbiota of patients with multiple sclerosis
Multiple sclerosis (MS) is a neurodegenerative inflammatory condition mediated by autoreactive immune processes. Due to its potential to influence host immunity and gut‐brain communication, the gut microbiota has been suggested to be involved in the onset and progression of MS. To date, there is no definitive cure for MS, and rehabilitation programs are of the utmost importance, especially in the later stages. However, only a few people generally participate due to poor support, knowledge, and motivation, and no information is available on gut microbiota changes. Herein we evaluated the potential of a brief high‐impact multidimensional rehabilitation program (B‐HIPE) in a leisure environment to affect the gut microbiota, mitigate MS symptoms and improve quality of life. B‐HIPE resulted in modulation of the MS‐typical dysbiosis, with reduced levels of pathobionts and the replenishment of beneficial short‐chain fatty acid producers. This partial recovery of a eubiotic profile could help counteract the inflammatory tone typically observed in MS, as supported by reduced circulating lipopolysaccharide levels and decreased populations of pro‐inflammatory lymphocytes. Improved physical performance and fatigue relief were also found. Our findings pave the way for integrating clinical practice with holistic approaches to mitigate MS symptoms and improve patients’ quality of life
Real Time Marine Data Acquisition: The Coastal Oceanographic Observatory Network in the Adriatic sea.
not availabl
Bridging the gap between chronic cerebrospinal venous insufficiency and Ménière disease
M\ue9ni\ue8re disease (MD) is a chronic illness of the inner ear that affects a substantial number of patients every year worldwide. Because of a dearth of well-controlled studies, the medical and surgical management of MD remains quite empirical. The main reason is that it is very difficult to investigate patients affected with \u201cCertain MD\u201d due to the post-mortem criterion necessary for this diagnostic grade. The aim of this paper is an attempt to approach MD into the context of the more recent findings about the global brain waste clearance system, to which inner ear is anatomically and functionally connected, in order to build a reasonable model of MD pathogenesis. it seems nowadays reasonable to state that CCSVI may be the anatomical background to develop endolymphatic hydrops in MD, the worldwide accepted pathogenetic mechanism of the disease. The mechanism leading from CCSVI to MD is still debated. Since MD has been correlated mostly to a wide and different diseases and treatments, CCSVI may be considered more than a cause of MD per se, rather the anatomical predisposition to develop the disease. CCSVI may lead to endolymphatic hydrops through a pure \u201chydraulic\u201d mechanism but in the model proposed in this paper CCSVI interplays with the Glymphatic (GS) and Brain Lymphatic System (LS) and MD development is due to a failure of the congenital venous abnormalities: MD develops when vascular and/or glymphatic and/or lymphatic compensation fails
A Systematic Review of Cerebral Functional Near-Infrared Spectroscopy in Chronic Neurological Diseases—Actual Applications and Future Perspectives
Background: The management of people affected by age-related neurological disorders requires the adoption of targeted and cost-effective interventions to cope with chronicity. Therapy adaptation and rehabilitation represent major targets requiring long-term follow-up of neurodegeneration or, conversely, the promotion of neuroplasticity mechanisms. However, affordable and reliable neurophysiological correlates of cerebral activity to be used throughout treatment stages are often lacking. The aim of this systematic review is to highlight actual applications of functional Near-Infrared Spectroscopy (fNIRS) as a versatile optical neuroimaging technology for investigating cortical hemodynamic activity in the most common chronic neurological conditions. Methods: We reviewed studies investigating fNIRS applications in Parkinson’s Disease (PD), Alzheimer’s Disease (AD) and Mild Cognitive Impairment (MCI) as those focusing on motor and cognitive impairment in ageing and Multiple Sclerosis (MS) as the most common chronic neurological disease in young adults. The literature search was conducted on NCBI PubMed and Web of Science databases by PRISMA guidelines. Results: We identified a total of 63 peer-reviewed articles. The AD spectrum is the most investigated pathology with 40 articles ranging from the traditional monitoring of tissue oxygenation to the analysis of functional resting-state conditions or cognitive functions by means of memory and verbal fluency tasks. Conversely, applications in PD (12 articles) and MS (11 articles) are mainly focused on the characterization of motor functions and their association with dual-task conditions. The most investigated cortical area is the prefrontal cortex, since reported to play an important role in age-related compensatory mechanism and neurofunctional changes associated to these chronic neurological conditions. Interestingly, only 9 articles applied a longitudinal approach. Conclusion: The results indicate that fNIRS is mainly employed for the cross-sectional characterization of the clinical phenotypes of these pathologies, whereas data on its utility for longitudinal monitoring as surrogate biomarkers of disease progression and rehabilitation effects are promising but still lacking
RESTAURI ROMANTICI ALL'OMBRA DEL CAMPANILE
Il saggio ripercorre la storia dei restauro alla basilica di San'Abbondio a Como con una cronologia degli interventi e un'ipotesi sullo stato di consistenza dell'edificio prima dei restaur
L'INGEGNER TATTI PROGETTAVA E SAN CARPOFORO CROLLAVA
L'articolo ripercorre la storia dei restauri alla basilica comasca di San Carpoforo
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