Body visual discontinuity affects feeling of ownership and skin conductance responses

When we look at our hands we are immediately aware that they belong to us and we rarely doubt about the integrity, continuity and sense of ownership of our bodies. Here we explored whether the mere manipulation of the visual appearance of a virtual limb could influence the subjective feeling of ownership and the physiological responses (Skin Conductance Responses, SCRs) associated to a threatening stimulus approaching the virtual hand. Participants observed in first person perspective a virtual body having the right hand-forearm (i) connected by a normal wrist (Full-Limb) or a thin rigid wire connection (Wire) or (ii) disconnected because of a missing wrist (m-Wrist) or a missing wrist plus a plexiglass panel positioned between the hand and the forearm (Plexiglass). While the analysis of subjective ratings revealed that only the observation of natural full connected virtual limb elicited high levels of ownership, high amplitudes of SCRs were found also during observation of the non-natural, rigid wire connection condition. This result suggests that the conscious embodiment of an artificial limb requires a natural looking visual body appearance while implicit reactivity to threat may require physical body continuity, even non-naturally looking, that allows the implementation of protective reactions to threat

Self-Equilibrium state of V-Expander Tensegrity Beam

In this paper, we study an innovative class of tensegrity beams, obtained by a suitable assembly of elementary V-Expander tensegrity cells along a longitudinal axis in the three-dimensional space. Tensegrity structures, made by struts in compression and cables in tension, are an innovative structures by itself: they are similar only in appearance to conventional pin-joint structures (trusses), and their mechanics is strongly related to initial feasible self-stress states induced in absence of external loads. In particular, from a kinematical point of view these self-stress states avoid the activation of possible infinitesimal mechanisms. By a numerical study, we analyze the feasible self-stress states for lightweight tensegrity beams made by a suitable assembly of V-Expander elementary cells. Moreover, we analyze the influence on the feasible self-stress states of the addition of struts or cables starting from the simplest V-Expander configuration

Observation of an improved healing process in superficial skin wounds after irradiation with a blue-LED haemostatic device

The healing process of superficial skin wounds treated with a blue-LED haemostatic device is studied. Four mechanical abrasions are produced on the back of 10 Sprague Dawley rats: two are treated with the blue-LED device, while the other two are left to naturally recover. Visual observations, non-linear microscopic imaging, as well as histology and immunofluorescence analyses are performed 8 days after the treatment, demonstrating no adverse reactions neither thermal damages in both abraded areas and surrounding tissue. A faster healing process and a better-recovered skin morphology are observed: the treated wounds show a reduced inflammatory response and a higher collagen content. Blue LED induced photothermal effect on superficial abrasions

Feeling of ownership over an embodied avatar's hand brings about fast changes of fronto-parietal cortical dynamics

When we look at our body parts, we are immediately aware that they belong to us and we rarely doubt about the integrity, continuity, and sense of ownership of our body. Despite this certainty, immersive virtual reality (IVR) may lead to a strong feeling of embodiment over an artificial body part seen from a first-person perspective (1PP). Although such feeling of ownership (FO) has been described in different situations, it is not yet understood how this phenomenon is generated at neural level. To track the real-time brain dynamics associated with FO, we delivered transcranial magnetic stimuli over the hand region in the primary motor cortex (M1) and simultaneously recorded electroencephalography (EEG) in 19 healthy volunteers (11 male/8 female) watching IVR renderings of anatomically plausible (full-limb) versus implausible (hand disconnected from the forearm) virtual limbs. Our data show that embodying a virtual hand is temporally associated with a rapid drop of cortical activity of the onlookers' hand region in the M1 contralateral to the observed hand. Spatiotemporal analysis shows that embodying the avatar's hand is also associated with fast changes of activity within an interconnected fronto-parietal circuit ipsilateral to the brain stimulation. Specifically, an immediate reduction of connectivity with the premotor area is paralleled by an enhancement in the connectivity with the posterior parietal cortex (PPC) which is related to the strength of ownership illusion ratings and thus likely reflects conscious feelings of embodiment. Our results suggest that changes of bodily representations are underpinned by a dynamic cross talk within a highly-plastic, fronto-parietal network

Successful ventricular tachycardia radioablation in a patient with previous chemical pleurodesis: A case report

IntroductionStereotactic arrhythmia radioablation (STAR) is a novel technique for the ablation of ventricular tachycardia in patients with contraindications to standard procedures, i.e., radiofrequency ablation.Case presentationWe report the case of a 73-year-old man with non-ischemic dilated cardiomyopathy and recurrent VT episodes. Electroanatomic mapping showed VT prevalently of epicardial origin, but direct epicardial access through subxyphoid puncture could not be performed due to pleuropericardial adhesions from a past history of chemical pleurodesis. STAR was performed, with no VT recurrence at 6 months follow-up.ConclusionsPrevious experiences with STAR have demonstrated its importance in the management of patients with refractory VT in whom other ablation strategies were not successful. Our case report highlights the use of STAR as a second choice in a patient with an unfavorable VT anatomical location and technical limitations to an optimal radiofrequency ablation. Moreover, it confirms STAR's effectiveness in the ablation of complex transmural lesions, which are more often associated with non-ischemic structural heart disease

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Machine Learning Characterization of Ictal and Interictal States in EEG Aimed at Automated Seizure Detection

Background: The development of automated seizure detection methods using EEG signals could be of great importance for the diagnosis and the monitoring of patients with epilepsy. These methods are often patient-specific and require high accuracy in detecting seizures but also very low false-positive rates. The aim of this study is to evaluate the performance of a seizure detection method using EEG signals by investigating its performance in correctly identifying seizures and in minimizing false alarms and to determine if it is generalizable to different patients. Methods: We tested the method on about two hours of preictal/ictal and about ten hours of interictal EEG recordings of one patient from the Freiburg Seizure Prediction EEG database using machine learning techniques for data mining. Then, we tested the obtained model on six other patients of the same database. Results: The method achieved very high performance in detecting seizures (close to 100% of correctly classified positive elements) with a very low false-positive rate when tested on one patient. Furthermore, the model portability or transfer analysis revealed that the method achieved good performance in one out of six patients from the same dataset. Conclusions: This result suggests a strategy to discover clusters of similar patients, for which it would be possible to train a general-purpose model for seizure detection

A novel method for determining the feasible integral self-stress states for tensegrity structures

The form-finding analysis is a crucial step for determining the stable self-equilibrated states for tensegrity structures, in the absence of external loads. This form-finding problem leads to the evaluation of both the self-stress in the elements and the shape of the tensegrity structure. This paper presents a novel method for determining feasible integral self-stress states for tensegrity structures, that is self-equilibrated states consistent with the unilateral behaviour of the elements, struts in compression and cables in tension, and with the symmetry properties of the structure. In particular, once defined the connectivity between the elements and the nodal coordinates, the feasible self-stress states are determined by suitably investigating the Distributed Static Indeterminacy (DSI). The proposed method allows for obtaining feasible integral self-stress solutions by a unique Singular Value Decomposition (SVD) of the equilibrium matrix, whereas other approaches in the literature require two SVD. Moreover, the proposed approach allows for effectively determining the Force Denstiy matrix, whose properties are strictly related to the super-stability of the tensegrity structures. Three tensegrity structures were studied in order to assess and discuss the efficiency and accuracy of the proposed innovative method