892 research outputs found
Scalar-tensor theories, trace anomalies and the QCD-frame
We consider the quantum effects of matter fields in scalar-tensor theories
and clarify the role of trace anomaly when switching between conformally
related `frames'. We exploit the property that the couplings between the scalar
and the gauge fields are not frame-invariant in order to define a `QCD-frame',
where the scalar is not coupled to the gluons. We show that this frame is a
natural generalization of the `Jordan frame' in the case of non-metric theories
and that it is particularly convenient for gravitational phenomenology: test
bodies have trajectories that are as close as possible to geodesics with
respect to such a metric and equivalence principle violations are directly
proportional to the scalar coupling parameters written in this frame. We show
how RG flow and decoupling work in metric and non-metric theories. RG-running
commutes with the operation of switching between frames at different scales.
When only matter loops are considered, our analysis confirms that metricity is
stable under radiative corrections and shows that approximate metricity is
natural in a technical sense.Comment: 10 pages. Minor changes to the main text, appendix added. To appear
on PR
A Cognitive Social IoT Approach for Smart Energy Management in a Real Environment
Energy usage inside buildings is a critical problem, especially considering high loads such as Heating, Ventilation and Air Conditioning (HVAC) systems: around 50% of the buildings’ energy demand resides in HVAC usage which causes a significant waste of energy resources due to improper uses. Usage awareness and efficient management have the potential to reduce related costs. However, strict saving policies may contrast with users’ comfort. In this sense, this paper proposes a multi-user multi-room smart energy management approach where a trade-off between the energy cost and the users’ thermal comfort is achieved. The proposed user-centric approach takes advantage of the novel paradigm of the Social Internet of Things to leverage a social consciousness and allow automated interactions between objects. Accordingly, the system automatically obtains the thermal profiles of both rooms and users. All these profiles are continuously updated based on the system experience and are then analysed through an optimization model to drive the selection of the most appropriate working times for HVACs. Experimental results in a real environment demonstrated the cognitive behaviour of the system which can adapt to users’ needs and ensure an acceptable comfort level while at the same time reducing energy costs compared to traditional usage
How to exploit the Social Internet of Things: Query Generation Model and Device Profiles’ Dataset
The future Internet of Things (IoT) will be characterized by an increasing number of object-to-object interactions for the implementation of distributed applications running in smart environments. The Social IoT (SIoT) is one of the possible paradigms that is proposed to make the objects’ interactions easier by facilitating the search of services and the management of objects’ trustworthiness. In this scenario, we address the issue of modeling the queries that are generated by the objects when fulfilling applications’ requests that could be provided by any of the peers in the SIoT. To this, the defined model takes into account the objects’ major features in terms of typology and associated functionalities, and the characteristics of the applications. We have then generated a dataset, by extracting objects’ information and positions from the city of Santander in Spain. We have classified all the available devices according to the FIWARE Data Models, so as to enable the portability of the dataset among different platforms. The dataset and the proposed query generation model are made available to the research community to study the navigability of the SIoT network, with an application also to other IoT networks. Experimental analyses have also been conducted, which give some key insights on the impact of the query model parameters on the average number of hops needed for each search
Numerical methods for fluctuation driven interactions between dielectrics
We develop a discretized theory of thermal Casimir interactions to
numerically calculate the interactions between fluctuating dielectrics. From a
constrained partition function we derive a surface free energy, while handling
divergences that depend on system size and discretization. We derive analytic
results for parallel plate geometry in order to check the convergence of the
numerical methods. We use the method to calculate vertical and lateral Casimir
forces for a set of grooves.Comment: revtex, 20 page
Implementation of a multi-approach fake news detector and of a trust management model for news sources
Technological development combined with the evolution of the Internet has made it possible to reach an increasing number of people over the years and given them the opportunity to access information published on the network. The growth in the number of fake news generated daily, combined with the simplicity with which it is possible to share them, has created such a large phenomenon that it has become immediately uncontrollable. Furthermore, the quality with which malicious content is made is increasingly high so even professional experts, such as journalists, have difficulty recognizing which news is fake and which is real. This paper aims to implement an architecture that provides a service to final users that assures the reliability of news providers and the quality of news based on innovative tools. The proposed models take advantage of several Machine Learning approaches for fake news detection tasks and take into account well-known attacks on trust. Finally, the implemented architecture is tested with a well-known dataset and shows how the proposed models can effectively identify fake news and isolate malicious sources
An Easy Route to Enantiomerically Enriched 7- and 8-Hydroxystearic Acids by Olefin Metathesis - Based Approach
The synthesis of enantiomerically enriched 7- and 8-hydroxystearic acids (7- and 8-HSA) has been successfully accomplished starting from chiral non racemic 1-pentadecen-4-ol and 1-tetradecen-4-ol respectively. Their Yamaguchi\u2019s esterification with 4-pentenoic and 5-hexenoic acids respectively afforded the suitable dienic esters which were submitted to ring closing metathesis reaction. After hydrogenation and basic hydrolysis of the complex reaction mixture, chiral non racemic 7- and 8-HSA were obtained in about 40% total yield
Freeze-drying of Beauveria bassiana suspended in Hydroxyethyl cellulose based hydrogel as possible method for storage: Evaluation of survival, growth and stability of conidial concentration before and after processing
Beauveria bassiana (Bb) is an entomopathogenic fungus considered as a valid alternative to chemical pesticides. However, Bb use is still limited due to short storage period and persistence in field conditions. Storage can be extended by reducing water content in products but an excessive drying can cause damage during rehydration. Persistence is promoted by using conidia into pellets or granules formulation. Integration of these two aspects can be challenging and costly. In this work, we present how utilizing a hydrogel containing Bb as growth substrate could potentially overcome both issues
OnabotulinumtoxinA 100U provides significant improvements in overactive bladder symptoms in patients with urinary incontinence regardless of the number of anticholinergic therapies used or reason for inadequate management of overactive bladder
INTRODUCTION: A prespecified pooled analysis of two placebo-controlled, phase 3 trials evaluated whether the number of prior anticholinergics used or reason for their discontinuation affected the treatment response to onabotulinumtoxinA 100U in overactive bladder (OAB) patients with urinary incontinence (UI). METHODS: Patients with symptoms of OAB received intradetrusor injections of onabotulinumtoxinA 100U or placebo, sparing the trigone. Change from baseline at week 12 in UI episodes/day, proportion of patients reporting a positive response (‘greatly improved’ or ‘improved’) on the treatment benefit scale (TBS), micturition and urgency were evaluated by number of prior anticholinergics (1, 2 or ≥ 3) and reason for their discontinuation (insufficient efficacy or side effects). Adverse events (AE) were assessed. RESULTS: Patients had taken an average of 2.4 anticholinergics before study enrolment. OnabotulinumtoxinA reduced UI episodes/day from baseline vs. placebo, regardless of the number of prior anticholinergics (−2.82 vs. −1.52 for one prior anticholinergic; −2.58 vs. −0.58 for two prior anticholinergics; and −2.92 vs. −0.73 for three or more prior anticholinergics; all p < 0.001). The proportion of TBS responders was higher with onabotulinumtoxinA vs. placebo (69.0% vs. 37.2% for one prior anticholinergic; 58.8% vs. 24.8% for two prior anticholinergics and 56.4% vs. 22.5% for three or more prior anticholinergics; all p < 0.001). Similar results were observed regardless of the reason for discontinuation. OnabotulinumtoxinA reduced the episodes of urgency and frequency of micturition vs. placebo in all groups. AEs were well tolerated, with a comparable incidence in all groups. CONCLUSION: In patients with symptoms of OAB who were inadequately managed by one or more anticholinergics, onabotulinumtoxinA 100U provided significant and similar treatment benefit and safety profile regardless of the number of prior anticholinergics used or reason for inadequate management of OAB. ClinicalTrials.gov: NCT00910845, NCT00910520
Naturalness in Cosmological Initial Conditions
We propose a novel approach to the problem of constraining cosmological
initial conditions. Within the framework of effective field theory, we classify
initial conditions in terms of boundary terms added to the effective action
describing the cosmological evolution below Planckian energies. These boundary
terms can be thought of as spacelike branes which may support extra
instantaneous degrees of freedom and extra operators. Interactions and
renormalization of these boundary terms allow us to apply to the boundary terms
the field-theoretical requirement of naturalness, i.e. stability under
radiative corrections. We apply this requirement to slow-roll inflation with
non-adiabatic initial conditions, and to cyclic cosmology. This allows us to
define in a precise sense when some of these models are fine-tuned. We also
describe how to parametrize in a model-independent way non-Gaussian initial
conditions; we show that in some cases they are both potentially observable and
pass our naturalness requirement.Comment: 35 pages, 8 figure
Steady-state visual evoked potentials and phase synchronization in migraine
We investigate phase synchronization in EEG recordings from migraine
patients. We use the analytic signal technique, based on the Hilbert transform,
and find that migraine brains are characterized by enhanced alpha band phase
synchronization in presence of visual stimuli. Our findings show that migraine
patients have an overactive regulatory mechanism that renders them more
sensitive to external stimuli.Comment: 4 page
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