Search results for "Graph theory"
showing 10 items of 784 documents
‘La chiamiamo con entrambi i nomi’: eponimia ed eteronimia tra Nemesis e Adrasteia
2020
Prendendo le mosse da un passo di Ammiano Marcellino (XIV 11,25), che lascia emergere un’evidente sovrapposizione tra la figura di Adrasteia e quella Nemesis, il contributo si propone di esaminare le ragioni che hanno condotto le due potenze ad essere indicate l’una come l’eteronimo dell’altra. A partire dalle fonti di V secolo fino alla paremiografia e alla lessicografia di età imperiale si ricostruisce un percorso che si propone di mostrare gli accidenti e le molteplici variabili cui le logiche di denominazione del divino, nel mondo greco, possono essere soggette. Starting from a passage by Ammiano Marcellino (XIV 11,25), which reveals an evident overlap between the figure of Adrasteia an…
Aberrant Subnetwork and Hub Dysconnectivity in Adult Bipolar Disorder: A Multicenter Graph Theory Analysis
2021
Abstract Neuroimaging evidence implicates structural network-level abnormalities in bipolar disorder (BD); however, there remain conflicting results in the current literature hampered by sample size limitations and clinical heterogeneity. Here, we set out to perform a multisite graph theory analysis to assess the extent of neuroanatomical dysconnectivity in a large representative study of individuals with BD. This cross-sectional multicenter international study assessed structural and diffusion-weighted magnetic resonance imaging data obtained from 109 subjects with BD type 1 and 103 psychiatrically healthy volunteers. Whole-brain metrics, permutation-based statistics, and connectivity of h…
Path Following in Non-Visual Conditions.
2018
Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on continuous, non-speech, and ecological auditory and vibrotactile cues to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causin…
Transient seizure onset network for localization of epileptogenic zone: effective connectivity and graph theory-based analyses of ECoG data in tempor…
2018
Objective: Abnormal and dynamic epileptogenic networks cause difficulties for clinical epileptologists in the localization of the seizure onset zone (SOZ) and the epileptogenic zone (EZ) in preoperative assessments of patients with refractory epilepsy. The aim of this study is to investigate the characteristics of time-varying effective connectivity networks in various non-seizure and seizure periods, and to propose a quantitative approach for accurate localization of SOZ and EZ. Methods: We used electrocorticogram recordings in the temporal lobe and hippocampus from seven patients with temporal lobe epilepsy to characterize the effective connectivity dynamics at a high temporal resolution …
Modular Control of Pointing beyond Arm's Length
2009
Hand reaching and bipedal equilibrium are two important functions of the human motor behavior. However, how the brain plans goal-oriented actions combining target reaching with equilibrium regulation is not yet clearly understood. An important question is whether postural control and reaching are integrated in one single module or controlled separately. Here, we show that postural control and reaching motor commands are processed by means of a modular and flexible organization. Principal component and correlation analyses between pairs of angles were used to extract global and local coupling during a whole-body pointing beyond arm's length. A low-dimensional organization of the redundant ki…
The Decreasing Prevalence of the Arcuate Foramen
2018
[Background]: The arcuate foramen (AF), or ponticulus posticus, is an anatomic variant of the first cervical vertebra that consists of a complete or partial osseous bridge over the groove for the vertebral artery and extends from the posterior aspect of the superior articular facet to the superior lateral border of the posterior arch. The AF has been associated with clinical symptoms, such as headache, migraine, neck pain, shoulder pain, arm pain, and vertebral artery dissection. We aimed to test whether the prevalence of the AF has decreased in the modern human population over the past centuries as a result of reduction in inbreeding and endogamy.
Tumor in the Horseshoe Kidney: Clinical Implications and Review of Embryogenesis
1992
We report on 3 patients with tumor in a horseshoe kidney, 1 of whom had bilateral tumor (renal cell cancer on the right side and urothelial cancer on the left side). Tumors that arise predominantly in the bridge of a horseshoe kidney can mimic the symptoms of an intra-abdominal disease process. Besides routine diagnostic procedures, angiography is essential to plan the surgical approach, which in principle should be organ-sparing. The literature of the embryology of the horseshoe kidney was reviewed for a relationship between the abnormal renal development and the site of tumorigenesis, and for development of a key for the wide variation of blood supply. Recently reported data suggest that …
Gray matter integrity predicts white matter network reorganization in multiple sclerosis
2019
Abstract Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease leading to gray matter atrophy and brain network reconfiguration as a response to increasing tissue damage. We evaluated whether white matter network reconfiguration appears subsequently to gray matter damage, or whether the gray matter degenerates following alterations in white matter networks. MRI data from 83 patients with clinically isolated syndrome and early relapsing–remitting MS were acquired at two time points with a follow‐up after 1 year. White matter network integrity was assessed based on probabilistic tractography performed on diffusion‐weighted data using graph theoretical analyses. We ev…
A new morphologic classification of the alveolar ridge after distraction osteogenesis in human patients. A 17 years retrospective case series study
2020
Background To perform a morphologic classification based on the results of bone augmentation after a distraction osteogenesis. Material and Methods Thirty-four (34) patients (24 women and 10 men; mean age, 47.1 years (SD=9.5); age range, 23 to 62 years) underwent a total of 42 alveolar ridge distractions before the placement of a total of 89 dental implants. Ridge bone morphology was evaluated as the main ordinal variable. Chi-squared, Kruskal-Wallis and ANOVA one-way test were used. Results Category I (30.95%): consisted of wide alveolar rim and no bone defects Category II (28.57%): wide alveolar rim, lateral bone surface concavity. Category III (23.81%): narrow alveolar rim, lateral bone …
An Agent-Based Model of Extortion Racketeering
2016
Mafias can be considered as criminal organisations that are in the business of producing, promoting, and selling protection. Here, we describe the Palermo Scenario, an agent-based model of protection rackets aimed to deepen our understanding of protection rackets, and help policymakers to evaluate methods for destabilising them. Additionally, since the system is explicitly specified, we can use it to investigate the entire causal pathway from cause to effect: not only from actions to Mafia destabilisation, but also the intermediate actions along the path and actors' internal mental representations among the population.