The statistical mechanics of turbo codes

The "turbo codes", recently proposed by Berrou et. al. are written as a disordered spin Hamiltonian. It is shown that there is a threshold Theta such that for signal to noise ratios v^2 / w^2 > Theta, the error probability per bit vanishes in the thermodynamic limit, i.e. the limit of infinitly long sequences. The value of the threshold has been computed for two particular turbo codes. It is found that it depends on the code. These results are compared with numerical simulations.Comment: 23 pages, 6 figures: Fig.2 has been replaced (in the preceding version it was identical to Fig.1

Ethical and medico-legal remarks on uterus transplantation: may it solve uterine factor infertility?

Uterus transplantation was firstly tested with animal trials sixty-five years ago. Despite several successful attempts in human subjects, the different procedures still lay at the experimental stage, in need of further studies and investigations before they can be considered as standard clinical practices. Uterus transplant cannot be regarded as a life-saving procedure, but rather a method to restore woman ability to procreate, when lost, thus improving her quality of life. Uterus transplant is a complex surgical procedure and presents significant health threats. Medical staff should therefore always obtain informed consent from patients, emphasizing such risks. Before that, women undergoing uterine transplants should be thoroughly informed about the hazards inherent to the procedure and especially about the dangers of immunosuppressant drugs, administered after the surgery which may injure the fetus, eventually formed in the restored organ and even lead to its death, thus nullifying the purpose of the transplant itself. Therefore, the risk-benefit ratio of uterus transplantation needs to be carefully assessed and described

Medical use of cannabis: italian and european legislation

This review illustrates some brief considerations of the medical use of cannabis recently issued in Italy. History and uses of cannabis throughout centuries and different countries are illustrated together with a description of botany and active phytocannabinoids. Then, medical use of cannabis anti-pain treatment for patients resistant to conventional therapies is described in case of chronic neuropathic pain, spasticity, for anticinetosic and antiemetic effect in nausea and vomiting caused by chemotherapy, for appetite stimulating effect in cachexia, anorexia, loss of appetite in cancer patients or patients with AIDS and in anorexia nervosa, hypotensive effect in glaucoma resistant to conventional therapies and for reduction of involuntary body and facial movements in Gilles de la Tourette syndrome. Italian most recent legislation on medical cannabis is detailed with some law proposals, also showing the inconsistent legislation within European Union. Some final considerations of future studies are also reported

A Framework for Indoor Positioning Including Building Topology

In many application domains, position information is of fundamental importance. However, unlike the case of outdoor positioning, producing an accurate position estimation in the indoor setting turns out to be quite difficult. One of the most common localisation strategies makes use of fingerprinting. Research in this area has been faced with a number of challenges, leading to the proposal of a number of localisation algorithms, sampling strategies, benchmark datasets, and representations of building information. This proliferation made the modeling of the indoor positioning domain quite hard from both a theoretical and a practical point of view. In this paper, we propose a general and extensible framework, based on a relational database, that pairs fingerprints with building information. We show how the proposed system successfully deals with a number of problems that affect indoor positioning, supporting a large set of relevant tasks. The source code of the framework is available online, as well as an implementation of it, that provides an interactive open repository of indoor positioning data

Generalized Jacobi identities and ball-box theorem for horizontally regular vector fields

We consider a family of vector fields and we assume a horizontal regularity on their derivatives. We discuss the notion of commutator showing that different definitions agree. We apply our results to the proof of a ball-box theorem and Poincar\'e inequality for nonsmooth H\"ormander vector fields.Comment: arXiv admin note: material from arXiv:1106.2410v1, now three separate articles arXiv:1106.2410v2, arXiv:1201.5228, arXiv:1201.520

Error-correcting code on a cactus: a solvable model

An exact solution to a family of parity check error-correcting codes is provided by mapping the problem onto a Husimi cactus. The solution obtained in the thermodynamic limit recovers the replica symmetric theory results and provides a very good approximation to finite systems of moderate size. The probability propagation decoding algorithm emerges naturally from the analysis. A phase transition between decoding success and failure phases is found to coincide with an information-theoretic upper bound. The method is employed to compare Gallager and MN codes.Comment: 7 pages, 3 figures, with minor correction

FRAMH: A Federated Learning Risk-Based Authorization Middleware for Healthcare

Modern healthcare systems operate in highly dy- namic environments requiring adaptable access control mecha- nisms. Access to sensitive data and medical equipment should be granted or denied according to the current health situation of the patient. To handle the need for adaptable access control of healthcare scenarios, we propose a novel model that allows dynamic access control decisions based on the context character- izing the source, type of access request, patient, and estimated risk corresponding to the conditions of the patient. Estimating patient status risk requires analyzing vital physiological data whose availability is growing thanks to the widespread diffusion of the Internet of Medical Things (IoMT) devices. Inferring the patient health status risk through Machine Learning (ML) techniques is possible, but to achieve better accuracy, the training phase requires the aggregation of vast amounts of data from different sources. This aggregation could be difficult or even impossible due to organization regulations and privacy laws. To address these issues, this paper proposes a novel Federated Learning Risk-based Authorization Middleware for Healthcare (FRAMH) that supports risk-based access control to deal with changing and unforeseen medical situations. Our solution infers the risk of health status through a federated learning (FL) approach enriched with blockchain to avoid the weaknesses of centralized servers. The implemented prototype and a large set of experimental results demonstrate the advantages of FL in estimating the risk in healthcare scenarios. Through this approach, even a medical institution with a limited dataset can achieve a satisfying risk estimation and efficient access control enforcement

Target Controllability and Target Observability of Structured Network Systems

The duality between controllability and observability enables methods developed for full-state control to be applied to full-state estimation, and vice versa. In applications in which control or estimation of all state variables is unfeasible, the generalized notions of output controllability and functional observability establish the minimal conditions for the control and estimation of a target subset of state variables, respectively. Given the seemly unrelated nature of these properties, thus far methods for target control and target estimation have been developed independently in the literature. Here, we characterize the graph-theoretic conditions for target controllability and target observability (which are, respectively, special cases of output controllability and functional observability for structured systems). This allow us to rigorously establish a weak and strong duality between these generalized properties. When both properties are equivalent (strongly dual), we show that efficient algorithms developed for target controllability can be used for target observability, and vice versa, for the optimal placement of sensors and drivers. These results are applicable to large-scale networks, in which control and monitoring are often sought for small subsets of nodes.Comment: Codes are available in GitHub (https://github.com/montanariarthur/TargetCtrb

Dielectric approaches for interactions of protons, positrons, and electrons in cold matter and plasmas

This work investigates the projectile and temperature dependence of the energy loss of charged particles in matter. To this end, we analyze two dielectric approaches which consider the presence of bound and free electrons and the effects of the ionization process. With these approaches, we calculate the energy-loss moments of protons, positrons, and electrons traversing Si, Fe, and Al targets, both in the cold solid phase and in the plasma state. We compare the results from the unified-wave-packet model (UWPM) and the shellwise local plasma approximation (SLPA) on an extensive range of parameters, including low, intermediate, and high projectile energies and target temperatures going from cold solid-state densities to hot plasma with temperatures up to 1000 eV. We reformulate the SLPA to include light-particle restrictions. We give special consideration to the case of positrons and electrons, where the inner-shell effects have not been analyzed in our previous works. Comparisons with experimental results for cold solid targets are presented, and stopping enhancement effects for heated targets are described, showing the physical origin of these effects.Fil: Archubi, Claudio Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Montanari, Claudia Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Arista, N. R.. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro | Universidad Nacional de Cuyo. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro; Argentin