Referential description of the evolution of a 2D swarm of robots interacting with the closer neighbors. Perspectives of continuum modeling via higher gradient continua

In the present paper a discrete robotic system model whose elements interact via a simple geometric law is presented and some numerical simulations are provided and discussed. The main idea of the work is to show the resemblance between the cases of first and second neighbors interaction with (respectively) first and second gradient continuous deformable bodies. Our numerical results showed indeed that the interaction and the evolution process described is suitable to closely reproduce some basic characteristics of the behavior of bodies whose deformation energy depends on first or on higher gradients of the displacement. Moreover, some specific qualitative characteristics of the continuous deformation are also reproduced. The model introduced here will need further investigation and generalization in both theoretical and numerical directions

Modeling Deformable Bodies Using Discrete Systems with Centroid-Based Propagating Interaction: Fracture and Crack Evolution

International audienceWe use a simple discrete system in order to model deformation and fracture within the same theoretical and numerical framework. The model displays a rich behavior, accounting for different fracture phenomena, and in particular for crack formation and growth. A comparison with standard Finite Element simulations and with the basic Griffith theory of fracture is provided. Moreover, an ‘almost steady’ state, i.e. a long apparent equilibrium followed by an abrupt crack growth, is obtained by suitably parameterizing the system. The model can be easily generalized to higher order interactions corresponding, in the homogenized limit, to higher gradient continuum theories

Pareto-Optimization of HTS CICC for High-Current Applications in Self-Field

The ENEA superconductivity laboratory developed a novel design for Cable-in-Conduit Conductors (CICCs) comprised of stacks of 2nd-generation REBCO coated conductors. In its original version, the cable was made up of 150 HTS tapes distributed in five slots, twisted along an aluminum core. In this work, taking advantage of a 2D finite element model, able to estimate the cable's current distribution in the cross-section, a multiobjective optimization procedure was implemented. The aim of optimization was to simultaneously maximize both engineering current density and total current flowing inside the tapes when operating in self-field, by varying the cross-section layout. Since the optimization process involved both integer and real geometrical variables, the choice of an evolutionary search algorithm was strictly necessary. The use of an evolutionary algorithm in the frame of a multiple objective optimization made it an obliged choice to numerically approach the problem using a nonstandard fast-converging optimization algorithm. By means of this algorithm, the Pareto frontiers for the different configurations were calculated, providing a powerful tool for the designer to achieve the desired preliminary operating conditions in terms of engineering current density and/or total current, depending on the specific application field, that is, power transmission cable and bus bar systems

Laparoscopic gynecological surgery under minimally invasive anesthesia: a prospective cohort study

The purpose of this study is to assess the feasibility and the perioperative outcomes of laparoscopic gynecological surgery in regional anesthesia (RA) from the point of view of the surgeon, anesthesiologist and patient. This is a prospective cohort study comprising sixty-six women planned to undergo gynecologic laparoscopy surgery for benign pathology at tertiary care gynecolgical center of the University Federico II of Naples. Women were assigned, according to their preference, to either RA (Group A) or general anesthesia (GA) (Group B). Surgical, anesthesiologic and postoperative recovery data were recorded. Postoperative pain was considered as the primary outcome. Secondary outcomes included mobilization, length of hospital stay, global surgeons and patient satisfaction, intraoperative pain assessment in Group A. Immediate postoperative pain was significantly lower in Group A 0 vs 2 (p < 0.001), with no significant differences at 24 h. The secondary outcome demonstrated early patient's mobilization (p < 0.001) as well as early discharge (p < 0.001) and greater patient's satisfaction for the Group A. In these patients, a maximum pain score of 3 points out of 5 was recorded through the entire surgery. RA showed to decrease the impact of surgical stress and to guarantee a quicker recovery without compromising surgical results. Although several surgical approaches can be employed to treat different conditions, RA technique could be a viable option for well-selected patients affected by gynecological diseases

Characterization of HTS coils for superconducting rotating electric machine applications : challenges, material selection, winding process, and testing

The second-generation high-Temperature superconducting tapes (2G-HTS) such as the REBCO coated conductors are known for their strong mechanical properties and high current carrying capacity with low ac losses compared with first-generation HTS tapes as well as low-Temperature superconductors. Therefore, they seem to be good candidates to assemble coils for superconducting rotating electric machines (SuREMs). In this article, to investigate the influence of a soft magnetic composite (SMC) material on the dc and ac HTS coil performances at cryogenic temperatures, GdBCO-and YBCO-based commercial tapes from different manufactures were used to assemble ten HTS coils in double-pancake configuration. These tapes were wound using two different core structures, i.e., fixed and movable cores, having the same circular shape but different diameters as well as materials, i.e., fiberglass and SMC. Critical currents and ac transport current losses of these coils were measured using the electrical method. To evaluate the parallel and perpendicular components of the profile of magnetic flux density for each assembled HTS coil, a finite element model has been developed using Maxwell 2D. Eventually, the performance of different coils for SuREM application was discussed

Technical Report: Anomaly Detection for a Critical Industrial System using Context, Logs and Metrics

Recent advances in contextual anomaly detection attempt to combine resource metrics and event logs to un- cover unexpected system behaviors and malfunctions at run- time. These techniques are highly relevant for critical software systems, where monitoring is often mandated by international standards and guidelines. In this technical report, we analyze the effectiveness of a metrics-logs contextual anomaly detection technique in a middleware for Air Traffic Control systems. Our study addresses the challenges of applying such techniques to a new case study with a dense volume of logs, and finer monitoring sampling rate. We propose an automated abstraction approach to infer system activities from dense logs and use regression analysis to infer the anomaly detector. We observed that the detection accuracy is impacted by abrupt changes in resource metrics or when anomalies are asymptomatic in both resource metrics and event logs. Guided by our experimental results, we propose and evaluate several actionable improvements, which include a change detection algorithm and the use of time windows on contextual anomaly detection. This technical report accompanies the paper “Contextual Anomaly Detection for a Critical Industrial System based on Logs and Metrics” [1] and provides further details on the analysis method, case study and experimental results

The Need for a Specific Risk Prediction System in Native Valve Infective Endocarditis Surgery

The need for a specific risk score system for infective endocarditis (IE) surgery has been previously claimed. In a single-center pilot study, preliminary to future multicentric development and validation, bivariate and multivariate (logistic regression) analysis of early postoperative mortality predictors in 440 native valve IE patients were performed. Mathematical procedures assigned scores to the independent predictors emerged (AUC of the ROC curve: 0.88). Overall mortality was 9.1%. Six predictors were identified and assigned scores, including age (5–13 points), renal failure (5), NYHA class IV (9), critical preoperative state (11), lack of preoperative attainment of blood culture negativity (5), perivalvular involvement (5). Four risk classes were drawn ranging from “very low risk” (≤5 points, mean predicted mortality 1%), and to “very high risk” (≥20 points, 43% mortality). IE-specific risk stratification models are both needed, as disease-specific factors (e.g., cultures, abscess), beside the generic ones (e.g., age, renal impairment) affect mortality, and feasible

A rare case of true carcinosarcoma of the breast

AbstractBackgroundTrue carcinosarcoma of the breast is an extremely rare condition, accounting for 0.08–0.2% of all breast malignancies.The correct definition of this tumor requires both a carcinomatous component and a malignant non-epithelial component of mesenchymal origin, without evidence of a transition zone between the two elements.Case presentationWe present a case of a 49-year-old woman presenting with a 4cm mass at the level of her left breast upper-outer quadrant with a histologic diagnosis of true carcinosarcoma of the breast.DiscussionThe most appropriate therapeutic regimens for breast carcinosarcoma are still unclear because of the rarity of this condition, but Breast Conserving Treatment (BCT) followed by adjuvant chemotherapy seems to provide a prognosis equalling that of usual Invasive Ductal Carcinoma of the breast

Stroke subtypes and their possible implication in stroke prevention drug strategies

Thrombotic strokes can affect large or small arteries in the brain. Drugs to prevent atherosclerosis complication such as thrombotic strokes, should be drugs able to prevent the accumulation of intravascular fat, reduce vascular proliferation, decrease blood pressure levels with the resulting shear stress, reduce platelet aggregation, and possibly partially or totally reverse carotid plaques. Any of the commonly used antihypertensive drugs lower the incidence of stroke, with larger reductions in BP resulting in larger reductions in risk. Experimental and clinical data suggest that reducing the activity of the renin-angiotensin aldosterone system (RAAS) may have beneficial effects beyond the lowering of blood pressure to reduce stroke incidence. In clinical trials, statins consistently reduced the risk of ischemic stroke in patients with or without CHD whereas the data on the effects of other lipid modifying drugs on stroke risk are limited. Approximately 25% of strokes are recurrent. Antiplatelet therapy is indicated for the prevention of recurrent stroke in patients with a history of noncardioembolic minor stroke or transient ischemic attack (TIA). Although clinicians may choose acetylsalicylic acid (ASA) as first-line therapy for secondary prevention, clinical guidelines and evidence from trials suggest that ASA may not be the most effective strategy. A recent review discussed results from clinical trials that have compared the efficacy of ASA monotherapy versus ASA + extended release dipyridamole in secondary stroke prevention. Therefore it is difficult to extrapolate the real benefit of pharmacological prevention strategies against atherothrombotic subtype for excellence in the TOAST classification subtype that is represented by the LAAS and also with regard to lacunar subtype as an expression of lipohyalinosis process which is a further aspect of atherosclerosis