2,769 research outputs found
Entangling macroscopic diamonds at room temperature: Bounds on the continuous-spontaneous-localization parameters
A recent experiment [K. C. Lee et al., Science 334, 1253 (2011)] succeeded in
detecting entanglement between two macroscopic specks of diamonds, separated by
a macroscopic distance, at room temperature. This impressive results is a
further confirmation of the validity of quantum theory in (at least parts of)
the mesoscopic and macroscopic domain, and poses a challenge to collapse
models, which predict a violation of the quantum superposition principle, which
is the bigger the larger the system. We analyze the experiment in the light of
such models. We will show that the bounds placed by experimental data are
weaker than those coming from matter-wave interferometry and
non-interferometric tests of collapse models.Comment: 7 pages, 3 figures, v2: close to the published version, LaTe
Correlating densities of centrality and activities in cities : the cases of Bologna (IT) and Barcelona (ES)
This paper examines the relationship between street centrality and densities of commercial and service activities in cities. The aim is to verify whether a correlation exists and whether some 'secondary' activities, i.e. those scarcely specialized oriented to the general public and ordinary daily life, are more linked to street centrality than others. The metropolitan area of Barcelona (Spain) is investigated, and results are compared with those found in a previous work on the city of Bologna (Italy). Street centrality is calibrated in a multiple centrality assessment (MCA) model composed of multiple measures such as closeness, betweenness and straightness. Kernel density estimation (KDE) is used to transform data sets of centrality and activities to one scale unit for correlation analysis between them. Results indicate that retail and service activities in both Bologna and Barcelona tend to concentrate in areas with better centralities, and that secondary activities exhibit a higher correlation
The influence of diffusion- and relaxation-related factors on signal intensity: An introductive guide to magnetic resonance diffusion-weighted Imaging studies
Metabolic reprogramming promotes myogenesis during aging
Sarcopenia is the age-related progressive loss of skeletal muscle mass and strength finally leading to poor physical performance. Impaired myogenesis contributes to the pathogenesis of sarcopenia, while mitochondrial dysfunctions are thought to play a primary role in skeletal muscle loss during aging. Here we studied the link between myogenesis and metabolism. In particular, we analyzed the effect of the metabolic modulator trimetazidine (TMZ) on myogenesis in aging. We show that reprogramming the metabolism by TMZ treatment for 12 consecutive days stimulates myogenic gene expression in skeletal muscle of 22-month-old mice. Our data also reveal that TMZ increases the levels of mitochondrial proteins and stimulates the oxidative metabolism in aged muscles, this finding being in line with our previous observations in cachectic mice. Moreover, we show that, besides TMZ also other types of metabolic modulators (i.e., 5-Aminoimidazole-4-Carboxamide Ribofuranoside-AICAR) can stimulate differentiation of skeletal muscle progenitors in vitro. Overall, our results reveal that reprogramming the metabolism stimulates myogenesis while triggering mitochondrial proteins synthesis in vivo during aging. Together with the previously reported ability of TMZ to increase muscle strength in aged mice, these new data suggest an interesting non-invasive therapeutic strategy which could contribute to improving muscle quality and neuromuscular communication in the elderly, and counteracting sarcopenia
A Single Wearable Sensor for Gait Analysis in Parkinsonâs Disease: A Preliminary Study
Movement monitoring in patients with Parkinsonâs disease (PD) is critical for quantifying disease progression and assessing how a subject responds to medication administration over time. In this work, we propose a continuous monitoring system based on a single wearable sensor placed on the lower back and an algorithm for gait parameters evaluation. In order to preliminarily validate the proposed system, seven PD subjects took part in an experimental protocol in preparation for a larger randomized controlled study. We validated the feasibility of our algorithm in a constrained environment through a laboratory scenario. Successively, it was tested in an unsupervised environment, such as the home scenario, for a total of almost 12 h of daily living activity data. During all phases of the experimental protocol, videos were shot to document the tasks. The obtained results showed a good accuracy of the proposed algorithm. For all PD subjects in the laboratory scenario, the algorithm for step identification reached a percentage error low of 2%, 99.13% of sensitivity and 100% of specificity. In the home scenario the BlandâAltman plot showed a mean difference of â3.29 and â1 between the algorithm and the video recording for walking bout detection and steps identification, respectively
Machine Learning Approach for Care Improvement of Children and Youth with Type 1 Diabetes Treated with Hybrid Closed-Loop System
Type 1 diabetes is a disease affecting beta cells of the pancreas and itâs responsible for a decreased insulin secretion, leading to an increased blood glucose level. The traditional method for glucose treatment is based on finger-stick measurement of the blood glucose concentration and consequent manual insulin injection. Nowadays insulin pumps and continuous glucose monitoring systems are replacing them, being simpler and automatized. This paper focuses on analyzing and improving the knowledge about which Machine Learning algorithms can work best with glycaemic data and tries to find out the relation between insulin pump settings and glycaemic control. The dataset is composed of 90 days of recordings taken from 16 children and adolescents. Three Machine Learning approaches, two for classification, Logistic Regression (LR) and Random Forest (RL), and one for regression, Multivariate Linear Regression (MLR), have been used for the purpose. Specifically, the pump settings analysis was performed based on the Time In Range (TIR) computation and comparison consequent to pump setting changes. RF and MLR have shown the best results, while, for the settingsâ analysis, the data show a discrete correlation between changes and TIRs. This study provides an interesting closer look at the data recorded by the insulin pump and a suitable starting point for a thorough and complete analysis of them
Les perles dâĂ©mail: aspects ultrastructuraux et hypothĂšses de morphogenĂšse
Five enamel pearls were examined by Scanning Electron Microscope. Some external pearls presented a bare enamel surface, others were covered by a thin layer of cementum.The enamel pearls showed irregular dystrofic enamel surface or a thin layer without structure, rows of irregular Tomeâs processes pits, enamel caps and focal holes. Some enamel pearls revealed little areas of enamel surface resorption like-resorbing lacunae with, in some cases, areas of tissue repair.La perle dâĂ©mail est une masse circulaire de matĂ©riel calcifiĂ© qui apparait le plus souvent dans la bifurcation des molaires et est attachĂ©e Ă la surface externe de la dent. Elle peut aussi ĂȘtre interne mais nous en savons trĂšs peu Ă ce sujet Ă cause du manque de publications. Cinq perles externes ont Ă©tĂ© observĂ©es au microscope Ă©lectronique Ă balayage.Tandis que certaines perles externes prĂ©sentent une surface Ă nu, dâautres sont recouvertes dâune fine couche de cĂ©ment qui les protĂšge. La surface de la perle dâĂ©mail prĂ©sente des zones irrĂ©guliĂšres dâhypominĂ©ralisation ou une fine couche sans structure, des rangĂ©es de petits trous irrĂ©guliers des processus de Tome et des trous focaux et des cratĂšres
Dark Matter investigation by DAMA at Gran Sasso
Experimental observations and theoretical arguments at Galaxy and larger
scales have suggested that a large fraction of the Universe is composed by Dark
Matter particles. This has motivated the DAMA experimental efforts to
investigate the presence of such particles in the galactic halo by exploiting a
model independent signature and very highly radiopure set-ups deep underground.
Few introductory arguments are summarized before presenting a review of the
present model independent positive results obtained by the DAMA/NaI and
DAMA/LIBRA set-ups at the Gran Sasso National Laboratory of the INFN.
Implications and model dependent comparisons with other different kinds of
results will be shortly addressed. Some arguments put forward in literature
will be confuted.Comment: review article, 71 pages, 25 figures, 8 tables; v2: minor
modifications. In publication on the International Journal of Modern Physics
Muon-Induced Background Study for Underground Laboratories
We provide a comprehensive study of the cosmic-ray muon flux and induced
activity as a function of overburden along with a convenient parameterization
of the salient fluxes and differential distributions for a suite of underground
laboratories ranging in depth from 1 to 8 km.w.e.. Particular attention
is given to the muon-induced fast neutron activity for the underground sites
and we develop a Depth-Sensitivity-Relation to characterize the effect of such
background in experiments searching for WIMP dark matter and neutrinoless
double beta decay.Comment: 18 pages, 28 figure
The event generator DECAY4 for simulation of double beta processes and decay of radioactive nuclei
The computer code DECAY4 is developed to generate initial energy, time and
angular distributions of particles emitted in radioactive decays of nuclides
and nuclear (atomic) deexcitations. Data for description of nuclear and atomic
decay schemes are taken from the ENSDF and EADL database libraries. The
examples of use of the DECAY4 code in several underground experiments are
described.Comment: 8 pages, 1 fi
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