The ever increasing demand in passenger and freight transportation is leading to the saturation of railway network capacity. Virtual Coupling (VC) has been proposed within the European Horizon 2020 ...Shift2Rail Joint Undertaking as a potential solution to address this problem. It allows to dynamically connect two or more trains in a single convoy, thus reducing headway between them. In this work, we investigate the main challenges related to the potential deployment of VC in railways. Its feasibility through Reinforcement Learning techniques is explored, discussing about technical implementation and performance issues. A qualitative analysis based on a Deep Deterministic Policy Gradient control algorithm is proposed. The aim is to give a first insight towards the definition of a qualitative and technology roadmap which could lead to the deployment of artificial intelligence applications aiming at enhancing rail safety and automation.
Over the last 3 years new definitions of sarcopenia by the Sarcopenia Definition and Outcome Consortium (2020, SDOC), European Working Group on Sarcopenia in Older People (2019, EWGSOP2) and Asian ...Working Group on Sarcopenia (2019, AWGS2) have been proposed. The objective of this scoping review was to explore predictive validity of these current sarcopenia definitions for clinical outcomes. We followed the PRISMA checklist for scoping reviews. Based on a systematic search performed by two independent reviewers of databases (Pubmed and Embase) articles comparing predictive validity of two or more sarcopenia definitions on prospective clinical outcomes published since January 2019 (the year these definitions were introduced) were included. Data were extracted and results collated by clinical outcomes and by sarcopenia definitions, respectively. Of 4493 articles screened, 11 studies (mean age of participants 77.6 (SD 5.7) years and 50.0% female) comprising 82 validity tests were included. Overall, validity tests on the following categories of clinical outcomes were performed: fracture (n = 40, assessed in one study), mortality (n = 18), function (n = 11), institutionalization (n = 7), falls (n = 4), and hospitalization (n = 2). Thereby, EWGSOP2 was investigated in 15 validity tests (18.3%) on all categories of clinical outcomes, whereas SDOC was investigated in four validity tests (4.9%) in one study on fractures in men only, and none of the validity tests investigated predictive validity by the AWGS2. However, we were not able to pool the data using a meta‐analytic approach due to important methodological heterogeneity between the studies. We identified various definitions of clinical outcomes that were used to test predictive validity of sarcopenia definitions suggesting that an agreement on an operational definition of a clinical outcome is key to advance in the field of sarcopenia. Moreover, data on predictive validity using the sarcopenia definitions by the SDOC and AWGS2 are still scarce and lacking, respectively. In a next step, prospective studies including both women and men are needed to compare predictive validity of current sarcopenia definitions on defined key clinical outcomes.
Background: Studies on the role of mast cells (MC) in cancer have given contrasting results. In order to contribute to the
clarification of their role, research on breast cancer was carried out, ...because some aspects of its carcinogenesis, such as
the diversity of the hormonal component, differ greatly. Materials and Methods: This study included 50 cases of invasive ductal
breast cancer not otherwise specified (NOS): 25 of them were high hormone-receptive (HHR) cancers with estrogen and progesterone
receptor values not lower than 50%, 25 were minimum hormone-receptive (MHR) cancers (<5%). In both groups, mast cells were
quantified in the peritumoral area. Twenty cases of surgical interventions for non-neoplastic esthetic prosthesis in healthy
women were examined as controls. The proliferation index Ki-67 (MIB1) and the c-erb B2 receptor protein were also considered
in cancer patients. Mast cells were detected using Giemsa and Alcian blue stains. Results: The results obtained showed that
there was a highly significant increase in the number of mast cells mainly in the peritumoral area in HHR cancer cases (p<0.0001)
compared to MHR cancers and controls (p<0.0001). Comparison between mast cells in MHR cancer and control cases was not significant
(p=0.114). Hormone-receptive cancers have a less severe prognosis for their higher responsiveness to therapy. This element
may suggest that the higher mast cell number present in these types of cancer is a favorable prognostic factor. Moreover,
mast cells tend to accumulate around the cancer area and this can be seen as an attempt to oppose the progression of the anomalous
tissue. Mast cells were reported to exhibit cytolytic activity against tumor cells.
Background: Mast cells (MCs) remain enigmatic more than 100 years after their discovery by Paul Ehrlich. Continuous research
over the last 20 years has finally characterized the origin of MCs and ...determined many of the factors involved in MC differentiation
and proliferation. MCs are traditionally known for mediating allergic reactions. In addition, these cells have been implicated
in the pathogenesis of clinical conditions. Studies on the role of MCs in cancer have given contrasting results. Materials
and Methods: This study included 50 cases of invasive ductal breast cancer not otherwise specified (NOS): 25 of them were
highly hormone-receptive (HHR) cancers with estrogen and progesterone receptor values not lower than 50%, 25 were minimally
hormone-receptive (MHR) cancers (<5%). In both groups, mast cells were quantified in the peritumoral area. Twenty cases of
surgical interventions without cancer were included as controls. Results: It was found that in infiltrating ductal breast
cancers having a high hormone receptor content (>50% for both estrogen and progesterone), there was a highly significant increase
in MCs with respect to hypo-hormonal cancers in the same location and to controls (p<0.0001). MCs have thus proven to be very
important cells because they have been found in sites playing an active role in opposing the aggression of the cancer cells
(CCs). MCs may represent a protective factor of the human body against cancer aggresion. Two biological phenomena with the
same goal can be observed: CCs are first phagocytized by MCs and then completely destroyed by karyocytoplasmic chemolysis
through the action of toxicophore granulations. It was demonstrated that one or more CCs are surrounded by an MC's pseudopodia
and then engulfed in its cytoplasm. The phagocytized cell progressively loses its chromatic and volumetric characteristics
until complete achromia and almost complete reduction of its volume and consistency occur. The cell nucleus soon degenerates
to pyknosis and becomes no longer detectable.
The new railway mobility paradigm Virtual Coupling, recognized as one of the most promising solutions to face the ever-increasing demand in railway transportation and the saturation of network ...capacity, enables two or more trains to virtually couple in a single convoy, hence reducing the headway among them. Within this context, the design of an effective and robust Virtual Coupling control strategy for uncertain nonlinear heterogeneous train convoys, able to simultaneously cope with uncertain nonlinearities and unexpected/unpredictable external factors, is an open challenge in the railway field. This is very crucial for High-Speed Trains, where, due to the high-speed operating ranges, uncertain factors have a stronger impact on Virtual Coupling performance. To deal with this issue, this work exploits the ability of Deep Reinforcement Learning based strategies in defining an optimal control policy via an iterative exploration of the surrounding unknown environment and without detailed knowledge of the plant dynamics. Specifically, we propose a novel Deep Deterministic Policy Gradient based control strategy to coordinate and manage the High-Speed Trains convoy such that this latter can autonomously adapt its behaviour to all the encountered driving scenarios. The effectiveness of the proposed approach is evaluated via simulation analyses, carried-out via an ad-hoc implemented Virtual Coupling Train System simulation platform. After verifying the efficiency of the training process in ensuring the fulfilment of the Virtual Coupling control objectives, extensive non-trivial simulations, also involving cooperative manoeuvres, are performed for the validation phase. Results confirm how the proposed model-free Deep Deterministic Policy Gradient approach guarantees the Virtual Coupling for nonlinear heterogeneous High-Speed Train convoys despite the co-presence of uncertainties and unknown external factors. Finally, the advantages and the benefits of the proposed data-driven control are disclosed via a comparison analysis against model-based control strategies.
We studied the serum levels of vitamins A, E, zinc and copper in two hundred and twenty-five subjects of both sexes. They
were divided into two groups: 87 healthy subjects who served as controls and ...138 patients with neoplastic disease. The patients
were subdivided according to the absence (n=79) or the presence of metastatic disease (n=59). In 59 patients with cancer,
who were in therapy with scavenger drugs of free radical such as calcium antagonists and the antagonists of receptors H 2 , we also studied the possible effect of the same therapy on the serum levels of vitamins, on the concentrations of the microelements
and on membrane lipid peroxidation. We found that membrane lipid peroxidation, evaluated from the time of in vitro formation
in the blood of so-called âHeinz bodies,â decreased in all patients treated with scavenger drugs. In these patients the permeability
of the erythrocyte membrane was similar to the controls and the serum levels of the vitamins were equal to the levels in patients
who did not receive these therapies. Zinc concentration increased while copper remained unchanged. We also studied the levels
of vitamins in some organs. The results are discussed considering the role of free radicals. We underline the importance of
vitamins A and E in the protection from membranous peroxidation and from free radicals and the need to consider cancer as
a systemic morbid event, apart from the contingent actual location.
This paper tackles and solves the problem of end-to-end autonomous driving endowed with safe features for coping with sensors faults. To this aim, an unsupervised Deep Q-leaning Network (DQN) is ...proposed for the anomaly detection while an actor-critic Deep Deterministic Policy Gradient-based (DDPG) agent drives the motion of the autonomous vehicles in safe manner. The model-free detection algorithm allows identifying the sensor faults and the outcome is exploited for safe driving an autonomous vehicle via the DDPG agent. This later controller is, hence, properly designed for achieving a end-to-end driving despite the presence of possible faults. The effectiveness of the proposed approach is virtually tested by leveraging the combined features of Python and TORCS suites. The validation phase investigates the effectiveness of the detection solution and how/if the DDPG agent has learned the safe correct behavior to be pursued for a safe end-to-end driving. Finally the overall performance in a realistic driving scenario proves the benefits of the proposed solution.
Virtual Coupling has been included among the most relevant innovations to be studied in the European Horizon 2020 Shift2Rail Joint Undertaking for increasing the railway lines capacity through the ...dynamic connection of two or more trains to form a convoy while preserving safety. Within this framework, this paper addresses the virtual coupling control problem for heterogeneous nonlinear uncertain connected high-speed trains. Leveraging the Multi-Agent Systems framework, a novel distributed robust and adaptive PI-like control scheme is proposed to solve the control problem. In order to provide suitable adaptive mechanisms for the control gains, we exploit the Lyapunov theory and Barbalat's lemma and prove the asymptotic stability for the overall networked control system, as well as the boundedness of these signals. The virtual coupling objective is achieved in a fully-distributed fashion by limiting the amount of time-varying information necessary for the computation of the control action and, hence, saving communication channel bandwidth while reducing the computational burden. Exemplary numerical simulations are given to support the theoretical derivations and to prove the effectiveness of the proposed control strategy in a real driving scenario.
This paper addresses the path-tracking control problem for Connected Autonomous Electric Vehicles (CAEVs) moving in a smart Cooperative Connected Automated Mobility (CCAM) environment, where a smart ...infrastructure suggests the reference behaviour to achieve. To solve this problem, a novel energy-efficient Deep Deterministic Policy Gradient-based (DDPG) Algorithm, able to minimize its energy consumption while guaranteeing the optimal tracking of the suggested path, is proposed. Specifically, in order to improve the power autonomy and the battery state of charge (SOC), a Comprehensive Power-based Electric Vehicle Consumption Model (CPEM) is exploited for the training of the DDPG agent. The training process confirms the capability of DDPG agent into learning the safe eco-driving policy, while a case of study proves the advantages and the performance of the overall closed-loop of the proposed control strategy.
This work addresses the problem of Virtual Coupling (VC) control for uncertain heterogeneous nonlinear autonomous trains convoys sharing information among each other with Radio Block Center (RBC) and ...via Train-2-Train (T2T) communication network. To solve the problem we propose a novel no-supervised actor-critic Deep Deterministic Policy Gradient-based (DDPG) controller which drives each train within the convoy to track the reference behaviour, as imposed by the RBC, while maintaining a desired inter-train distance w.r.t. the preceding train. The effectiveness of the proposed approach is evaluated via a numerical analysis which is carried out in Python environment. The first step of validation involves the efficiency of the training process and discloses how the agent has learned the correct behaviour to track the train ahead. Then, we numerically prove how the overall closed-loop trains convoy under the action of the DDPG controller reaches the VC formation despite the presence of external disturbances acting on the train dynamics.
