140 research outputs found

    Emotion as an emergent phenomenon of the neurocomputational energy regulation mechanism of a cognitive agent in a decision-making task:

    Get PDF
    Biological agents need to complete perception-action cycles to perform various cognitive and biological tasks such as maximizing their wellbeing and their chances of genetic continuation. However, the processes performed in these cycles come at a cost. Such costs force the agent to evaluate a tradeoff between the optimality of the decision making and the time and computational effort required to make it. Several cognitive mechanisms that play critical roles in managing this tradeoff have been identified. These mechanisms include adaptation, learning, memory, attention, and planning. One of the often overlooked outcomes of these cognitive mechanisms, in spite of the critical effect that they may have on the perception-action cycle of organisms, is "emotion." In this study, we hold that emotion can be considered as an emergent phenomenon of a plausible neurocomputational energy regulation mechanism, which generates an internal reward signal to minimize the neural energy consumption of a sequence of actions (decisions), where each action triggers a visual memory recall process. To realize an optimal action selection over a sequence of actions in a visual recalling task, we adopted a model-free reinforcement learning framework, in which the reward signal—that is, the cost—was based on the iteration steps of the convergence state of an associative memory network. The proposed mechanism has been implemented in simulation and on a robotic platform: the iCub humanoid robot. The results show that the computational energy regulation mechanism enables the agent to modulate its behavior to minimize the required neurocomputational energy in performing the visual recalling task

    APE Results of Hadron Masses in Full QCD Simulations

    Get PDF
    We present numerical results obtained in full QCD with 2 flavors of Wilson fermions. We discuss the relation between the phase of Polyakov loops and the {\bf sea} quarks boundary conditions. We report preliminary results about the HMC autocorrelation of the hadronic masses, on a 163×3216^3 \times 32 lattice volume, at β=5.55\beta=5.55 with ksea=0.1570k_{sea}=0.1570.Comment: 3 pages, compressed ps-file (uufiles), Contribution to Lattice 9

    Risk Factors of Right Ventricular Dysfunction and Adverse Cardiac Events in Patients with Repaired Tetralogy of Fallot

    Get PDF
    Aim: This study evaluates the risk factors associated with right ventricular (RV) dilation and dysfunction leading to pulmonary valve replacement (PVR) or adverse cardiac events in repaired Tetralogy of Fallot (rToF) patients. Methods: Data from all rToF patients who underwent magnetic resonance imaging (MRI) evaluation at our hospital between February 2007 and September 2020 were collected. Results: Three hundred and forty-two patients (60% males, 42% older than 18 years), with a median age of 16 years (IQR 13–24) at the time of MRI, were included. All patients underwent complete repair at a median age of 8 months (IQR 5–16), while palliation was performed in 56 patients (16%). One hundred and forty-four patients (42%) subsequently received pulmonary valve replacement (PVR). At the multivariate analysis, male gender was an independent predictor for significant RV dilation, RV and left ventricular (LV) dysfunction. Transventricular ventricular septal defect (VSD) closure and previous palliation significantly affected LV function and RV size, respectively. Male gender and the transventricular VSD closure were independent predictors for PVR. Conclusions: Male gender and surgical history (palliation, VSD closure approach) significantly affected the long-term outcomes in rToF patients and should be taken into consideration in the follow-up management and in PVR timing in this patient population

    Comparison between intrasylvian and intracerebral hematoma associated with ruptured middle cerebral artery aneurysms: clinical implications, technical considerations, and outcome evaluation

    Get PDF
    Background: Subarachnoid hemorrhage (SAH) due to a middle cerebral artery (MCA) aneurysms rupture is often associated with intracerebral (ICH) or intrasylvian hematomas (ISH). Materials and methods: We reviewed 163 patients with ruptured MCA aneurysms associated with pure SAH or SAH+ICH/ISH. Patients were first dichotomized according to the presence of a hematoma (ICH/ISH). Then, we performed a subgroup analysis comparing ICH versus ISH in order to explore their relationship with the most relevant demographic, clinical, and angioarchitectural features. Results: Overall, 85 patients (52%) had a pure SAH, whereas 78 (48%) presented an associated ICH/ISH. No significant differences were observed in demographics and angioarchitectural features between the two groups, but Fisher grading and Hunt-Hess score were higher in patients with hematomas. A good outcome was observed in a higher percentage of patients with pure SAH compared with the others (76% Vs 44%), although mortality rates were comparable. Age, Hunt-Hess and treatment-related complications were the main outcome predictors at multivariate analysis. Patients with ICH appeared clinically worse than those with ISH. We also found that older age, higher Hunt-Hess, larger aneurysms, decompressive craniectomy and treatment-related complications were associated with poor outcome among patients with ISH, but not with ICH, which appeared per se as a more severe clinical condition. Conclusions: Our study confirm that age, Hunt-Hess and treatment-related complications influence the outcome of patients with ruptured MCA aneurysms. However, in the subgroup analysis of patients with SAH associated with ICH or ISH, only the Hunt-Hess at onset appeared as an independent predictor of outcome

    Legal immigrants: invasion of alien microbial communities during winter occurring desert dust storms

    Get PDF
    Background A critical aspect regarding the global dispersion of pathogenic microorganisms is associated with atmospheric movement of soil particles. Especially, desert dust storms can transport alien microorganisms over continental scales and can deposit them in sensitive sink habitats. In winter 2014, the largest ever recorded Saharan dust event in Italy was efficiently deposited on the Dolomite Alps and was sealed between dust-free snow. This provided us the unique opportunity to overcome difficulties in separating dust associated from “domestic” microbes and thus, to determine with high precision microorganisms transported exclusively by desert dust. Results Our metagenomic analysis revealed that sandstorms can move not only fractions but rather large parts of entire microbial communities far away from their area of origin and that this microbiota contains several of the most stress-resistant organisms on Earth, including highly destructive fungal and bacterial pathogens. In particular, we provide first evidence that winter-occurring dust depositions can favor a rapid microbial contamination of sensitive sink habitats after snowmelt. Conclusions Airborne microbial depositions accompanying extreme meteorological events represent a realistic threat for ecosystem and public health. Therefore, monitoring the spread and persistence of storm-travelling alien microbes is a priority while considering future trajectories of climatic anomalies as well as anthropogenically driven changes in land use in the source regions

    COVID-19-associated Guillain-Barré syndrome in the early pandemic experience in Lombardia (Italy)

    Get PDF
    Objective To estimate the incidence and describe clinical characteristics and outcome of GBS in COVID-19 patients (COVID19-GBS) in one of the most hit regions during the frst pandemic wave, Lombardia. Methods Adult patients admitted to 20 Neurological Units between 1/3–30/4/2020 with COVID19-GBS were included as part of a multi-center study organized by the Italian society of Hospital Neuroscience (SNO). Results Thirty-eight COVID19-GBS patients had a mean age of 60.7 years and male frequency of 86.8%. CSF albuminocytological dissociation was detected in 71.4%, and PCR for SARS-CoV-2 was negative in 19 tested patients. Based on neurophysiology, 81.8% of patients had a diagnosis of AIDP, 12.1% of AMSAN, and 6.1% of AMAN. The course was favorable in 76.3% of patients, stable in 10.5%, while 13.2% worsened, of which 3 died. The estimated occurrence rate in Lombardia ranges from 0.5 to 0.05 GBS cases per 1000 COVID-19 infections depending on whether you consider positive cases or estimated seropositive cases. When we compared GBS cases with the pre-pandemic period, we found a reduction of cases from 165 to 135 cases in the 2-month study period in Lombardia. Conclusions We detected an increased incidence of GBS in COVID-19 patients which can refect a higher risk of GBS in COVID-19 patients and a reduction of GBS events during the pandemic period possibly due to a lower spread of more common respiratory infectious diseases determined by an increased use of preventive measures
    • …
    corecore