1,807 research outputs found
Squeezing in a nonlocal photon fluid
Quantum fluids of light are an emerging tool employed in quantum many-body
physics. Their amazing properties and versatility allow using them in a wide
variety of fields including gravitation, quantum information and simulation.
However the implications of the quantum nature of light in the nonlinear
optical propagation are still missing many features. We theoretically predict
classical spontaneous squeezing of a photon fluid in a nonlocal nonlinear
medium. By using the so called Gamow vectors, we show that the quadratures of a
coherent state get squeezed and that a maximal squeezing power exists. Our
analysis holds true for temporal and spatial optical propagation in highly
nonlocal regime. These results open a new scenario in quantum photon fluids and
may lead to novel applications in fields like metrology and analogues of
quantum gravity.Comment: 6 pages, 2 figure
Energetics and switching of quasi-uniform states in small ferromagnetic particles
We present a numerical algorithm to solve the micromagnetic equations based on tangential-plane minimization for the magnetization update and a homothethic-layer decomposition of outer space for the computation of the demagnetization field. As a first application, detailed results on the flower-vortex transition in the cube of Micromagnetic Standard Problem number 3 are obtained, which confirm, with a different method, those already present in the literature, and validate our method and code. We then turn to switching of small cubic or almost-cubic particles, in the single-domain limit. Our data show systematic deviations from the Stoner-Wohlfarth model due to the non-ellipsoidal shape of the particle, and in particular a non-monotone dependence on the particle size
c-Flip KO fibroblasts display lipid accumulation associated with endoplasmic reticulum stress
c-Flip proteins are well-known apoptosis modulators. They generally contribute to tissue homeostasis
maintenance by inhibiting death-receptor-mediated cell death.
In the present manuscript, we showthat c-Flip knock-out (KO) mouse embryonic fibroblasts (MEFs) kept in culture
under starvation conditions gradually modify their phenotype and accumulate vacuoles, becoming progressively
larger according to the duration of starvation. Large vacuoles are present in KO MEFs though not in WT
MEFs, and are Oil Red-O positive, which indicates that they represent lipid droplets. Western blot experiments
reveal that, unlikeWTMEFs, KOMEFs express high levels of the lipogenic transcription factor PPAR-γ. Lipid droplet
accumulation was found to be associated with endoplasmic reticulum (ER) stress activation and autophagic
modulation valuated by means of BIP increase, LC3 lipidation and AMP-activated protein kinase (AMPK) phosphorylation,
and p62 accumulation. Interestingly, XBP-1, an ER stress-induced lipogenic transcription factor,
was found to preferentially localize in the nucleus rather than in the cytoplasm of KO MEFs.
These data demonstrate that, upon starvation, c-Flip affects lipid accumulation, ER stress and autophagy, thereby
pointing to an important role of c-Flip in the adaptive response and ER stress response programs under both
normal and pathological conditions
Measuring Euro Area Monetary Policy Transmission in a Structural Dynamic Factor Model
We study the effects of euro area common monetary policy by means of a structural dynamic factor model estimated on a large panel of euro area quarterly series. While we estimate a flat response of prices to a monetary policy shock, which we explain as aggregation of heterogeneous country-specific responses, we find no relevant asymmetries between countries in terms of output reaction. However, for both Spain and Italy, we find asymmetries in consumption, investment and unemployment. The introduction of the single currency in 1999 has helped reducing asymmetries in price responses but not in consumption and investment.
Proteomics for Cerebrospinal Fluid Biomarker Identification in Parkinsons Disease: Methods and Critical Aspects
Parkinson's disease (PD), similar with other neurodegenerative disorders, would benefit from the identification of early biomarkers for differential diagnosis and prognosis to address prompt clinical treatments. Together with hypothesis driven approaches, PD has been investigated by high-throughput differential proteomic analysis of cerebrospinal fluid (CSF) protein content. The principal methodologies and techniques utilized in the proteomics field for PD biomarker discovery from CSF are presented in this mini review. The positive aspects and challenges in proteome-based biomarker research are also discussed
A 64mW DNN-based Visual Navigation Engine for Autonomous Nano-Drones
Fully-autonomous miniaturized robots (e.g., drones), with artificial
intelligence (AI) based visual navigation capabilities are extremely
challenging drivers of Internet-of-Things edge intelligence capabilities.
Visual navigation based on AI approaches, such as deep neural networks (DNNs)
are becoming pervasive for standard-size drones, but are considered out of
reach for nanodrones with size of a few cm. In this work, we
present the first (to the best of our knowledge) demonstration of a navigation
engine for autonomous nano-drones capable of closed-loop end-to-end DNN-based
visual navigation. To achieve this goal we developed a complete methodology for
parallel execution of complex DNNs directly on-bard of resource-constrained
milliwatt-scale nodes. Our system is based on GAP8, a novel parallel
ultra-low-power computing platform, and a 27 g commercial, open-source
CrazyFlie 2.0 nano-quadrotor. As part of our general methodology we discuss the
software mapping techniques that enable the state-of-the-art deep convolutional
neural network presented in [1] to be fully executed on-board within a strict 6
fps real-time constraint with no compromise in terms of flight results, while
all processing is done with only 64 mW on average. Our navigation engine is
flexible and can be used to span a wide performance range: at its peak
performance corner it achieves 18 fps while still consuming on average just
3.5% of the power envelope of the deployed nano-aircraft.Comment: 15 pages, 13 figures, 5 tables, 2 listings, accepted for publication
in the IEEE Internet of Things Journal (IEEE IOTJ
Cancer microenvironment and endoplasmic reticulum stress response
Different stressful conditions such as hypoxia, nutrient deprivation, pH changes, or reduced vascularization, potentially able to act as growth-limiting factors for tumor cells, activate the unfolded protein response (UPR). UPR is therefore involved in tumor growth and adaptation to severe environments and is generally cytoprotective in cancer. The present review describes the molecular mechanisms underlying UPR and able to promote survival and proliferation in cancer. The critical role of UPR activation in tumor growth promotion is discussed in detail for a few paradigmatic tumors such as prostate cancer and melanoma
Management of Distal Radius Fractures in the Elderly Patients
Distal radius fractures are one of the most common injuries treated by the
orthopedic surgeons representing almost 1/6 of the fractures that are treated in
the emergency departments and the 75% of all fractures of the upper limb and
are second only to hip fractures in elderly population. The age distribution of this
kind of injury is typically bimodal with peaks in the young patients (6-25) and
in the elderly patients older than 65. In the first case the mechanism of injury
is usually a high energy trauma, such as a car accident, whilst in the second
one is usually a low energy trauma like a domestic fall. Various classification
systems have been proposed for these fractures. The classic eponymy-based
classification, which divides the fractures in “Colles, Smith, Hutchinson, etc” is
always useful but we think that the best system could be a combination with the
classic eponymy-based classification with the one proposed by the AO Trauma.
Distal radius fractures are frequent in elderly active patients and are usually
treated with closed reduction and cast immobilization for 5-6 weeks. Decision
for surgical treatment in osteoporotic and elderly patients is difficult as there are
no significant differences of functional outcome after non surgical and surgical
treatment, patient’s comfort, pre- injury activity level, life style requirement,
stage of osteoporosis, fracture stability, joint congruency, loss of previous
reduction and bilateral fractures should be considered in decision making. Of
different kinds of surgical treatment we prefer k-wires fixation, epibloc or ORIF
with locking plate
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