Improving Cardiology-Rehospitalization Prediction Through the Synergy of Process Mining and Deep Learning: An Innovative Approach.

Nowadays, hospitals are facing the need for an accurate prediction of rehospitalizations. Rehospitalizations, indeed, represent both a high financial burden for the hospital and a proxy measure of care quality. The current work aims to address such a problem with an innovative approach, by building a Process Mining-Deep Learning model for the prediction of 6-months rehospitalization of patients hospitalized in a Cardiology specialty at San Raffaele Hospital, starting from their medical history contained in the Patients Hospital Records, with the double purpose of supporting resource planning and identifying at-risk patients.

Diurnal changes in the efficiency of information transmission at a sensory synapse.

Neuromodulators adapt sensory circuits to changes in the external world or the animal's internal state and synapses are key control sites for such plasticity. Less clear is how neuromodulation alters the amount of information transmitted through the circuit. We investigated this question in the context of the diurnal regulation of visual processing in the retina of zebrafish, focusing on ribbon synapses of bipolar cells.

Fighting healthcare rocketing costs with value-based medicine: the case of stroke management.

Value-Based Medicine (VBM) is imposing itself as 'a new paradigm in healthcare management and medical practice.In this perspective paper, we discuss the role of VBM in dealing with the large productivity issue of the healthcare industry and examine some of the worldwide industrial and technological trends linked with VBM introduction. To clarify the points, we discuss examples of VBM management of stroke patients.

Targeting neuronal and glial cell types with synthetic promoter AAVs in mice, non-human primates and humans.

Targeting genes to specific neuronal or glial cell types is valuable for both understanding and repairing brain circuits. Adeno-associated viruses (AAVs) are frequently used for gene delivery, but targeting expression to specific cell types is an unsolved problem. We created a library of 230 AAVs, each with a different synthetic promoter designed using four independent strategies.

Log files analysis and evaluation of circadian patterns for the early diagnosis of pump thrombosis with a centrifugal continuous-flow left ventricular assist device.

Background: No clinical standardized methods exist to identify the early stage of the development of pump thrombosis in the setting of HVAD (Medtronic Inc., USA) implantation. We aimed at developing a clinically relevant tool to evaluate HVAD operation during long-term support and at identifying a new reliable marker for the early diagnosis of pump thrombosis reflecting altered patient-pump physiological interplay.

Congenital Nystagmus Gene FRMD7 Is Necessary for Establishing a Neuronal Circuit Asymmetry for Direction Selectivity.

Neuronal circuit asymmetries are important components of brain circuits, but the molecular pathways leading to their establishment remain unknown. Here we found that the mutation of FRMD7, a gene that is defective in human congenital nystagmus, leads to the selective loss of the horizontal optokinetic reflex in mice, as it does in humans. This is accompanied by the selective loss of horizontal direction selectivity in retinal ganglion cells and the transition from asymmetric to symmetric inhibitory input to horizontal direction-selective ganglion cells.

A synaptic mechanism for temporal filtering of visual signals.

The visual system transmits information about fast and slow changes in light intensity through separate neural pathways. We used in vivo imaging to investigate how bipolar cells transmit these signals to the inner retina. We found that the volume of the synaptic terminal is an intrinsic property that contributes to different temporal filters.

Rapid mapping of visual receptive fields by filtered back projection: application to multi-neuronal electrophysiology and imaging.

Neurons in the visual system vary widely in the spatiotemporal properties of their receptive fields (RFs), and understanding these variations is key to elucidating how visual information is processed. We present a new approach for mapping RFs based on the filtered back projection (FBP), an algorithm used for tomographic reconstructions. To estimate RFs, a series of bars were flashed across the retina at pseudo-random positions and at a minimum of five orientations.

Olfactory stimulation selectively modulates the OFF pathway in the retina of zebrafish.

Cross-modal regulation of visual performance by olfactory stimuli begins in the retina, where dopaminergic interneurons receive projections from the olfactory bulb. However, we do not understand how olfactory stimuli alter the processing of visual signals within the retina. We investigated this question by in vivo imaging activity in transgenic zebrafish expressing SyGCaMP2 in bipolar cell terminals and GCaMP3.

Optimization of a GCaMP calcium indicator for neural activity imaging.

Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials in short bursts in several systems in vivo.

Color vision: retinal blues.

Two complementary studies have resolved the circuitry underlying green-blue color discrimination in the retina. A blue-sensitive interneuron provides the inhibitory signal required for computing green-blue color opponency.

Fractal behavior of spontaneous neurotransmitter release: from single-synapse to whole-cell recordings.

Spontaneous release of neurotransmitter vesicles at brain chemical synapses has been deeply investigated in the last decades at several levels. First and second order statistics have been widely adopted as a tool for assessing, inter-alia, dependence of spontaneous release on the concentration of ionic species in the intra- or extra-cellular environment. Furthermore, several studies demonstrated that spontaneous release exhibits fractal, and generally non purely random, behavior.

Spikes in retinal bipolar cells phase-lock to visual stimuli with millisecond precision.

Background: The conversion of an analog stimulus into the digital form of spikes is a fundamental step in encoding sensory information. Here, we investigate this transformation in the visual system of fish by in vivo calcium imaging and electrophysiology of retinal bipolar cells, which have been assumed to be purely graded neurons.

Results: Synapses of all major classes of retinal bipolar cell encode visual information by using a combination of spikes and graded signals.

Novel image processing methods for the analysis of calcium dynamics in glial cells.

Calcium (Ca(2+)) waves and Ca(2+) oscillations within cells initiate a wide range of physiological processes including control of cell signaling, gene expression, secretion, and cell migration. A thorough analysis of Ca(2+) waves in glial cells provides information not only about the subcellular location of signaling processing events but also about nonneuronal or intercellular signaling pathways, their timing, routes, spatial domains, and coordination. In this study, three novel image processing methods have been applied to the study of Ca(2+) dynamics in cells.

In vivo evidence that retinal bipolar cells generate spikes modulated by light.

Retinal bipolar cells have been assumed to generate purely graded responses to light. To test this idea we imaged the presynaptic calcium transient in live zebrafish. We found that ON, OFF, transient and sustained bipolar cells are all capable of generating fast 'all-or-none' calcium transients modulated by visual stimulation.

Study of neuronal networks development from in-vitro recordings: A Granger causality based approach.

This methodological work is aimed at providing a Granger causality based approach to the study of neuronal networks development in vitro. The analysis procedure makes use of tools derived from statistics and network theory for accessing network development of in-vitro neuronal cultures from their electrical activity, recorded through Multi Electrode Arrays (MEAs). The preliminary results that will be presented here show the potential of this approach for characterizing in a quantitative way the developmental stages of neuronal networks and provide some evidences which are consistent with direct in-vitro and in-vivo observations reported by other authors.

Exploiting the multiplicative nature of fluoroscopic image stochastic noise to enhance calcium imaging recording quality.

One of the main problems that affect fluoroscopic imaging is the difficulty in coupling the recorded activity with the morphological information. The comprehension of fluorescence events in relationship with the internal structure of the cell can be very difficult. At this purpose, we developed a new method able to maximize the fluoroscopic movie quality.

Statistical long-term correlations in dissociated cortical neuron recordings.

The study of nonlinear long-term correlations in neuronal signals is a central topic for advanced neural signal processing. In particular, the existence of long-term correlations in neural signals recorded via multielectrode array (MEA) could provide interesting information about changes in interneuron communications. In this study we propose a new method for long-term correlation analysis of neuronal burst activity based on the periodogram alpha slope estimation of the MEA signal.

A blind method for the estimation of the Hurst exponent in time series: theory and application.

Nowadays many methods for the estimation of self-similarity (Hurst coefficient, H) in time series are available. Most of them, even if very effective, need some a priori information to be applied. We analyzed the eight most used methods for H estimation (working both in time and in frequency).

Long-term invariant parameters obtained from 24-h Holter recordings: a comparison between different analysis techniques.

Over the last two decades, a large number of different methods had been used to study the fractal-like behavior of the heart rate variability (HRV). In this paper some of the most used techniques were reviewed. In particular, the focus is set on those methods which characterize the long memory behavior of time series (in particular, periodogram, detrended fluctuation analysis, rescale range analysis, scaled window variance, Higuchi dimension, wavelet-transform modulus maxima, and generalized structure functions).