Tommaso Gili

Tommaso Gili
IMT School for Advanced Studies Lucca · NETWORKS Complex Networks Research Unit

PhD

About

90
Publications
11,018
Reads
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1,804
Citations
Additional affiliations
September 2012 - September 2015
Foundation Santa Lucia
Position
  • Researcher
September 2010 - September 2012
Cardiff University
Position
  • Marie Curie Fellow
January 2003 - January 2006
Sapienza University of Rome
Position
  • PhD Student

Publications

Publications (90)
Preprint
Full-text available
Exploring the dynamics of a complex system, such as the human brain, poses significant challenges due to inherent uncertainties and limited data. In this study, we enhance the capabilities of noisy linear recurrent neural networks (lRNNs) within the reservoir computing framework, demonstrating their effectiveness in creating autonomous in silico re...
Preprint
Full-text available
Brain structure-function coupling has been studied in health and disease by many different researchers in recent years. Most of the studies have addressed functional connectivity matrices by estimating correlation coefficients between different brain areas, despite well-known disadvantages compared to partial correlation connectivity matrices. Inde...
Preprint
Full-text available
Understanding the dynamical behavior of complex systems from their underlying network architectures is a long-standing question in complexity theory. Therefore, many metrics have been devised to extract network features like motifs, centrality, and modularity measures. It has previously been proposed that network symmetries are of particular import...
Article
Full-text available
The renormalization group (RG) constitutes a fundamental framework in modern theoretical physics. It allows the study of many systems showing states with large-scale correlations and their classification into a relatively small set of universality classes. The RG is the most powerful tool for investigating organizational scales within dynamic syste...
Preprint
Full-text available
Ferroelectrics undergoing spontaneous symmetry breaking can manifest intricate domain patterns that allow the exploration of topological defects and their potential applications, such as domain-wall nanoelectronics. Engineering actual devices remains a challenge as domain patterns have complexity-driven properties whose origin and nature are still...
Preprint
Full-text available
In his book 'A Beautiful Question' [1], physicist Frank Wilczek argues that symmetry is 'nature's deep design,' governing the behavior of the universe, from the smallest particles to the largest structures [1-4]. While symmetry is a cornerstone of physics, it has not yet been found widespread applicability to describe biological systems [5], partic...
Preprint
Full-text available
The renormalization group (RG) constitutes a fundamental framework in modern theoretical physics. It allows the study of many systems showing states with large-scale correlations and their classification in a relatively small set of universality classes. RG is the most powerful tool for investigating organizational scales within dynamic systems. Ho...
Article
Tropical rainforests exhibit a rich repertoire of spatial patterns emerging from the intricate relationship between the microscopic interaction between species. In particular, the distribution of vegetation clusters can shed much light on the underlying process that regulates the ecosystem. Analyzing the distribution of vegetation clusters at diffe...
Article
Full-text available
We define bipartite and monopartite relational networks of chemical elements and compounds using two different datasets of inorganic chemical and material compounds, as well as study their topology. We discover that the connectivity between elements and compounds is distributed exponentially for materials, and with a fat tail for chemicals. Compoun...
Article
Full-text available
Inflammatory bowel diseases (IBDs) are complex medical conditions in which the gut microbiota is attacked by the immune system of genetically predisposed subjects when exposed to yet unclear environmental factors. The complexity of this class of diseases makes them suitable to be represented and studied with network science. In this paper, the meta...
Article
We present a comparison between various algorithms of inference of covariance and precision matrices in small data sets of real vectors of the typical length and dimension of human brain activity time series retrieved by functional magnetic resonance imaging (fMRI). Assuming a Gaussian model underlying the neural activity, the problem consists of d...
Article
Full-text available
Narratives are paradigmatic examples of natural language, where nouns represent a proxy of information. Functional magnetic resonance imaging (fMRI) studies revealed the recruitment of temporal cortices during noun processing and the existence of a noun-specific network at rest. Yet, it is unclear whether, in narratives, changes in noun density inf...
Poster
Full-text available
Moisture is the main factor that causes deterioration in cultural heritage objects made of porous materials. At the same time, it is essential to choose non-destructive and non-invasive approaches for more sustainable investigations and make them safe for the environment and the sample. The question addressed in the work concerns the possibility an...
Preprint
Full-text available
We present a comparison between various algorithms of inference of covariance and precision matrices in small datasets of real vectors, of the typical length and dimension of human brain activity time series retrieved by functional Magnetic Resonance Imaging (fMRI). Assuming a Gaussian model underlying the neural activity, the problem consists in d...
Article
Full-text available
In cultural heritage conservation science, moisture content (MC) is an essential factor to determine. At the same time, it is essential to choose non-destructive and non-invasive approaches for more sustainable investigations and make them safe for the environment and the sample. The question addressed in this work concerns the possibility and the...
Preprint
Full-text available
Tropical rainforests exhibit a rich repertoire of spatial patterns emerging from the intricate relationship between the microscopic interaction between species. In particular, the distribution of vegetation clusters can shed much light on the underlying process regulating the ecosystem. Analyzing the distribution of vegetation clusters at different...
Preprint
Full-text available
Heterogeneous and complex networks represent the intertwined interactions between real-world elements or agents. A fundamental problem of complex network theory involves finding inherent partitions, clusters, or communities. By taking advantage of the recent Laplacian Renormalization Group approach, we scrutinize information diffusion pathways thro...
Article
Full-text available
The renormalization group is the cornerstone of the modern theory of universality and phase transitions and it is a powerful tool to scrutinize symmetries and organizational scales in dynamical systems. However, its application to complex networks has proven particularly challenging, owing to correlations between intertwined scales. To date, existi...
Article
Full-text available
Complex networks usually exhibit a rich architecture organized over multiple intertwined scales. Information pathways are expected to pervade these scales reflecting structural insights that are not manifest from analyses of the network topology. Moreover, small-world effects correlate with the different network hierarchies complicating the identif...
Article
A set of discrete individual points located in an embedding continuum space can be seen as percolating or non-percolating, depending on the radius of the discs/spheres associated with each of them. This problem is relevant in theoretical ecology to analyze, e.g., the spatial percolation of a tree species in a tropical forest or a savanna. Here, we...
Preprint
Full-text available
Complex networks usually exhibit a rich architecture organized over multiple intertwined scales. Information pathways are expected to pervade these scales reflecting structural insights that are not manifest from analyses of the network topology. Moreover, small-world effects correlate with the different network hierarchies complicating the identif...
Article
Full-text available
Artificial intelligence (AI) models and procedures hold remarkable predictive efficiency in the medical domain through their ability to discover hidden, non-obvious clinical patterns in data. However, due to the sparsity, noise, and time-dependency of medical data, AI procedures are raising unprecedented issues related to the mismatch between docto...
Preprint
Full-text available
A set of discrete individual points located in an embedding continuum space can be seen as percolating or non-percolating, depending on the radius of the discs/spheres associated with each of them. This problem is relevant in theoretical ecology to analyze, e.g., the spatial percolation of a tree species in a tropical forest or a savanna. Here, we...
Preprint
Full-text available
The renormalization group is the cornerstone of the modern theory of universality and phase transitions, a powerful tool to scrutinize symmetries and organizational scales in dynamical systems. However, its network counterpart is particularly challenging due to correlations between intertwined scales. To date, the explorations are based on hidden g...
Article
Full-text available
Procedures and models of computerized data analysis are becoming researchers' and practitioners' thinking partners by transforming the reasoning underlying biomedicine. Complexity theory, Network analysis and Artificial Intelligence are already approaching this discipline, intending to provide support for patient's diagnosis, prognosis and treatmen...
Article
Statistical physics has proved essential to analyze multiagent environments. Motivated by the empirical observation of various nonequilibrium features in Barro Colorado and other ecological systems, we analyze a plant-species abundance model of neutral competition, presenting analytical evidence of scale-invariant plant clusters and nontrivial emer...
Article
Full-text available
The effects of osteopathic manipulative treatment (OMT) on functional brain connectivity in healthy adults is missing in the literature. To make up for this lack, we applied advanced network analysis methods to analyze resting state functional magnetic resonance imaging (fMRI) data, after OMT and Placebo treatment (P) in 30 healthy asymptomatic you...
Article
Full-text available
Several studies in recent times have linked gut microbiome (GM) diversity to the pathogenesis of cancer and its role in disease progression through immune response, inflammation and metabolism modulation. This study focused on the use of network analysis and weighted gene co-expression network analysis (WGCNA) to identify the biological interaction...
Article
Full-text available
Spontaneous oscillations of the blood oxygenation level-dependent (BOLD) signal are spatially synchronized within specific brain networks and are thought to reflect synchronized brain activity. Networks are modulated by the performance of a task, even if the exact features and degree of such modulations are still elusive. The presence of networks s...
Preprint
Full-text available
Objective To provide Covid-19 fatality rate, correlations with comorbidities and sensitivity of nasopharingeal swab. Design Prospective cohort study performed between February 21th and March 19rd, 2020 Setting Hospital-based study Participants Of 2,217 admitted, 766 consecutive individuals either reporting or presenting with fever, cough or dyspnea...
Article
Full-text available
Mechanisms of anesthetic drug-induced sedation and unconsciousness are still incompletely understood. Functional neuroimaging modalities provide a window to study brain function changes during anesthesia allowing us to explore the sequence of neuro-physiological changes associated with anesthesia. Cerebral perfusion change under an assumption of in...
Article
It has long been assumed that the language function is hierarchically organized into specific cortical areas. Here, for the first time, we present direct evidence that the spinal cord takes part in language processing. In a randomized-double blind design, sixteen aphasics underwent a language treatment combined with transcutaneous spinal direct cur...
Article
Full-text available
Osteopathic Manipulative Treatment (OMT) is a therapeutic approach aimed at enhancing the body's self-regulation focusing on somatic dysfunctions correction. Despite evidence of OMT effectiveness, the underlying neurophysiological mechanisms, as well as blood perfusion effects, are still poorly understood. The study aim was to address OMT effects o...
Preprint
Full-text available
Using a novel network analysis of spontaneous low-frequency functional MRI data recorded at rest, we study the functional network that describes the extent of synchronization among different areas of the brain. Comparing forty-four medicated patients and forty healthy subjects, we detected significant differences in the robustness of these function...
Article
Full-text available
The dynamics of the environment where we live in and the interaction with it, predicting events, provided strong evolutionary pressures for the brain functioning to process temporal information and generate timed responses. As a result, the human brain is able to process temporal information and generate temporal patterns. Despite the clear importa...
Article
Full-text available
Brain activity at rest is characterized by widely distributed and spatially specific patterns of synchronized low-frequency blood-oxygenation level-dependent (BOLD) fluctuations, which correspond to physiologically relevant brain networks. This network behaviour is known to persist also during task execution, yet the details underlying task-associa...
Article
Full-text available
The ability to generate probabilistic expectancies regarding when and where sensory stimuli will occur, is critical to derive timely and accurate inferences about updating contexts. However, the existence of specialized neural networks for inferring predictive relationships between events is still debated. Using graph theoretical analysis applied t...
Preprint
Modularity plays an important role in brain networks' architecture and influences its dynamics and the ability to integrate and segregate different modules of cerebral regions. Alterations in community structure are associated with several clinical disorders, specially schizophrenia, although its time evolution is not clear yet. In the present work...
Article
Full-text available
When can a system be unambiguously defined as “complex”? Although many real-world systems are believed to bear the signature of complexity, the question above remains unanswered. Our special issue aims at contributing to this ongoing discussion by collecting a number of studies tackling two aspects of complexity that have recently gained increasing...
Chapter
Methods enabling the characterization of brain morphometry have evolved exponentially in the last decades and have been shown important clinical applications. First MRI studies usually included a low number of subjects, but later on, it has become recognized that efforts from different research centers can be pooled by combining data acquisition an...
Chapter
During the last three decades, neuroimaging techniques have emerged as an essential tool for the noninvasive examination of subtle brain dysfunctions in psychiatric patient populations. These techniques helped clarify in vivo some of the principal neurobiological characteristic of the quintessential major mental disorder, schizophrenia, providing e...
Article
Full-text available
Recent studies have shown that the systematic and repetitive observation of actions belonging to the experiential human motor repertoire without verbal facilitation enhances the recovery of verbs in non fluent aphasia. However, it is still an open question whether this approach extends its efficacy also on discourse productivity by improving the re...
Article
Full-text available
Over the last 20 years, major advances in cognitive neuroscience have clearly shown that the language function is not restricted into the classical language areas but it involves brain regions, which had never previously considered. Indeed, recent lines of evidence have suggested that the processing of words associated to motor schemata, such as ac...
Article
Full-text available
Spontaneous low-frequency Blood-Oxygenation Level-Dependent (BOLD) signals acquired during resting state are characterized by spatial patterns of synchronous fluctuations, ultimately leading to the identification of robust brain networks. The resting-state brain networks, including the Default Mode Network (DMN), are demonstrated to persist during...
Data
Supplementary Figure 1 PSD difference between 1 back and 2 back. The figure reports the 95% confidence band for the difference of LFFs power spectral density between task levels 1-back and 2-back. The confidence band does not overlap zero only below 0.02 Hz.
Data
Supplementary Figure 2 Correlation between fALFF and FC changes within the DMN, unthresholded. Unthresholded map of the correlation between fALFF and FC changes within the DMN (unthresholded version of Figure 3). Correlation was generally around 0, except some clusters of positive correlation. Only one of them reached statistical significance (high...
Article
Full-text available
In the past few years, cognitive enhancing drugs (CEDs) have gained growing interest and the focus of investigations aimed at exploring their use to potentiate the cognitive performances of healthy individuals. Most of this exploratory CED-related research has been performed on young adults. However, CEDs may also help to maintain optimal brain fun...
Article
Introduction Several studies have already shown that transcranial direct current stimulation (tDCS) is an useful tool to enhance recovery in aphasia. However, no reports to date have investigated functional connectivity changes on cortical activity due to tDCS language treatment. Objectives The present study explored whether bilateral tDCS over th...
Article
Full-text available
The brain is a paradigmatic example of a complex system as its functionality emerges as a global property of local mesoscopic and microscopic interactions. Complex network theory allows to elicit the functional architecture of the brain in terms of links (correlations) between nodes (grey matter regions) and to extract information out of the noise....
Article
Several studies have already shown that transcranial direct current stimulation (tDCS) is a useful tool for enhancing recovery in aphasia. However, no reports to date have investigated functional connectivity changes on cortical activity because of tDCS language treatment. Here, nine aphasic persons with articulatory disorders underwent an intensiv...
Article
Full-text available
Low frequency fluctuations (LFFs) of the BOLD signal are a major discovery in the study of the resting brain with functional magnetic resonance imaging (fMRI). Two fMRI-based measures, functional connectivity (FC), a measure of signal synchronicity, and the amplitude of LFFs (ALFF), a measure of signal periodicity, have been proved to be sensitive...
Article
Full-text available
Alterations in the electrical passive parameters of red blood cell membranes occurring during storage have been investigated by means of two different experimental approaches, i.e., radiowave dielectric spectroscopy measurements and flow-cytometric measurements. We observed a correlation between the appearance of phosphatidylserine molecules in the...
Article
Full-text available
Despite their routine use during surgical procedures, no consensus has yet been reached on the precise mechanisms by which hypnotic anesthetic agents produce their effects. Molecular, animal and human studies have suggested disruption of thalamocortical communication as a key component of anesthetic action at the brain systems level. Here, we used...
Article
Full-text available
Interobserver reproducibility of measurements of the supraclavicular ultrasound view of the brachial plexus The performance of successful ultrasound-guided supraclavicular blocks currently relies upon appropriate two-dimensional ultrasound visualization, accurate interpretation of that image, and effective operator technique. Failure to do so can...
Article
Full-text available
A consistent and prominent feature of brain functional magnetic resonance imaging (fMRI) data is the presence of low-frequency (<0.1 Hz) fluctuations of the blood oxygenation level-dependent (BOLD) signal that are thought to reflect spontaneous neuronal activity. In this report we provide modeling evidence that cyclic physiological activation of as...
Article
Previous studies suggest that the clinical manifestations of Alzheimer's disease (AD) are not only associated with regional gray matter damage but also with abnormal functional integration of different brain regions by disconnection mechanisms. A measure of anatomical connectivity (anatomical connectivity mapping or ACM) can be obtained by initiati...
Article
Full-text available
To assess the contribution of regional grey matter (GM) atrophy and functional disconnection in determining the level of cognitive decline in patients with Alzheimer's disease (AD) at different clinical stages. Ten patients with amnesic mild cognitive impairment (a-MCI), 11 patients with probable AD and 10 healthy controls were recruited. T1 volume...
Conference Paper
Full-text available
Multimodality imaging plays a significant role on specific diagnosis of prostate cancer. An endorectal PET-TOF MRI probe, designed here, allows for improved SNR and NECR with respect to standard imagers, providing better functional diagnosis of prostate diseases.
Conference Paper
Full-text available
Introduction DTI technique has been used to investigate both collagen orientation (1-2) and proteoglycan degeneration (3). Cartilage aging is one of the leading risk factor for Osteoarthritis (4), and is generally associated to a reduction in water content. Some studies demonstrate that dehydration of cartilage matrix doesn't affect collagen networ...
Article
The hemocompatibility of standard surgical treatment of carotid artery disease through the insertion of metallic stents is investigated by means of radio wave dielectric spectroscopy technique that allows the measurements of the electrical parameters of the red blood cell membrane. Our measurements suggest that both the membrane permittivity and th...
Article
Correlated fluctuations of low-frequency fMRI signal have been suggested to reflect functional connectivity among the involved regions. However, large-scale correlations are especially prone to spurious global modulations induced by coherent physiological noise. Cardiac and respiratory rhythms are the most offending component, and a tailored prepro...
Conference Paper
Full-text available
NMR represents a powerful tool to investigate, non-invasively, water diffusion in living systems. Specifically, Diffusion-Tensor-Imaging (DTI) [1] is a quite recent NMR technique which is especially sensitive to anisotropic molecular diffusion. DTI method provides parametric maps where pixel intensity is proportional either to mean diffusivity (MD)...
Article
Full-text available
One of the main limitations for BNCT effectiveness is the insufficient intake of (10)B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumula...
Article
Boron neutron capture therapy (BNCT) is a radiotherapeutic modality based on (10)B(n,alpha)(7)Li reaction, for the treatment of malignant gliomas. One of the main limitations for BNCT effectiveness is the insufficient intake of (10)B nuclei in the tumor cells. This work was aimed at investigating the use of L-DOPA as a putative enhancer for (10)B-d...
Conference Paper
Full-text available
Introduction: NMR diffusion techniques have recently found application in characterization of cartilage. Several in vitro studies, performed with DTI methods, have demonstrated their consistence with the known collagen fibre architecture. Moreover, NMR data are in accord to polarised light microscopy and scanning electron microscopy data, recognisi...
Article
The aging of water suspension of the synthetic clay Laponite has been studied by liquid-state triple-quantum filter nuclear magnetic resonance techniques, in a range of clay weight concentration (Cw = 0.012-0.028) known as the isotropic phase. Counterions dynamic parameters (rotational correlation time tauc and quadrupolar coupling constant e2qQ/h)...