IRIS Università degli Studi dell'Aquila
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Cambiare la scuola. Partire dall’ascolto degli studenti.
No full textLa ricerca presentata è finalizzata a costruire e validare uno strumento atto a stimare il benessere degli studenti di scuola secondaria superiore in ambito scolastico e a esplorare gli eventuali legami fra i diversi aspetti che possono influenzare il sentirsi bene e a proprio agio a scuola. Lo strumento è stato costruito partendo da due specifiche esigenze: ascoltare la voce degli studenti per rilevare quali elementi dovrebbero essere presi in considerazione per migliorare la loro esperienza di vita scolastica e rispondere, almeno in parte, al bisogno delle scuole di avere uno strumento profondamente calato sulle specificità del contesto e utilizzabile per definire azioni o strategie che supportino i membri della comunità scolastica sia nell’acquisizione di consapevolezza dello stato dell’arte sia delle possibili vie per il miglioramento. Lo strumento, costituito da 65 domande chiuse e da 3 domande aperte, è stato somministrato tra aprile e giugno 2023 su un campione di convenienza di 871 studenti frequentanti due licei del Lazio, e ne è stata realizzata una prima validazione (Lucisano & Botta, 2023) che ha messo in luce un modello con un fattore di Benessere comprendente sei sottoscale, Considerazione, Senso di protezione, Ambiente, Valutazione degli insegnanti, Didattica attiva, Coesione della classe, e due distinti fattori di ansia, Ansia generale e Ansia da valutazione. In questo lavoro si vogliono presentare i risultati dell’analisi delle domande aperte che costituiscono un elemento rilevante dello strumento perché consentono di avere un quadro più specifico di che cosa chiedono gli studenti per migliorare la loro scuola. Sono stati raccolti quasi 1700 suggerimenti sui quali è stata effettuata un’analisi categoriale dalla quale sono emerse, in prima istanza, 12 categorie. Fra queste si notano quelle relative all’Ambiente, che trovano riscontro anche i risultati dell’analisi del questionario, da cui emerge che il fattore ambiente ha la maggiore quota di varianza spiegata e la media di scala più bassa fra i fattori di benessere, e quelle connesse alla Valutazione e alla Didattica. I suggerimenti degli studenti, in molti casi, nella loro chiarezza e specificità, richiamano con forza principi pedagogici che la scuola dovrebbe aver acquisito da tempo: il bisogno di una didattica attiva, la necessità di essere partecipi e avere una voce, la richiesta di una valutazione per l’apprendimento, tempi e spazi per la socializzazione
Exploring Cellulose Fibers as Support for a Microbial Inoculant Immobilitation
No full textCreating robust and long-lasting storage solutions presents a major challenge in developing microbial inoculants for eco-friendly farming. Well-developed techniques for anchoring bacteria onto solid supports are available, and growing interest is focusing on the implementation of sustainable carrier materials. This work aims to examine the utilization of cellulose functional fibers, chemically altered by the integration of natural polymers derived from the pulp industry. The fibers were assessed as a carrier for a consortium of plant growth-promoting bacteria. The consortium was immobilized on fibers culturing the strains in a combined fermentation with the addition of fibers (1% w/v) to allow microbial self-adhesion to the surface. The fibers were added at three specific stages of the bioreaction (0, 24 hours, and 48 hours), utilizing two separate culture mediums. Desiccation was executed using freeze-drying and heat-drying techniques. Cell viability was assessed in never-dried functional fibers and dried fibers until one month from inoculation, after drying. Immobilized bacteria were also assessed for plant growth-promoting (PGP) traits, encompassing indoles, ammonia production, and phosphate solubilization. Never-dried fibers demonstrated a favorable microbial load (between 6.78 and 8.22 Log CFU g-1), although the cell viability after drying diminished more than 1 Log CFU g-1 relative to the never-dried matter. Notable findings were achieved when comparing the two distinct growth conditions and the timing of functional fiber inoculation. Post-drying disparities between unmodified fibers and functional fibers were observed, underscoring the possible role of natural polymers in enhancing cellular protection. Plant growth-promoting testing exhibited advantageous results relative to the non-immobilized consortia. These results establish a foundation for additional research, concentrating on shelf-life assessments and suitable applications in plant and greenhouse investigations
Multipoint Observations and Modeling of the 2021 November 4 Forbush Decrease Using Solar Orbiter, CSES-01, and Ground-based Neutron Monitor Data
Full text linkDuring their propagation in the heliosphere, interplanetary coronal mass ejections (ICMEs) interact with galactic cosmic ray (GCR) particles, modifying their spectrum and driving anisotropies. We analyze the first large Forbush decrease (FD) of Solar Cycle 25 on 2021 November 3–5 by using multipoint in situ observations and neutron monitors to study the association between FD characteristics and ICME. We use the Grad–Shafranov reconstruction to infer the magnetic field configuration of the ICME. We model the neutron monitor response through primary spectrum and anisotropy. The primary spectrum is parameterized with the force-field approximation and the anisotropy is modeled through a spherical harmonic expansion. We optimize the model parameters during the FD by using ground-based observations provided by the worldwide neutron-monitor network. The model's results are compared with space-based measurements of the differential proton flux measured by the HEPD-01 detector on board the CSES-01 satellite and of the integral counts of both the High-Energy Particle Detector (HEPD-01) and the High Energy Telescope on board the Solar Orbiter. Anisotropy develops during the ICME passage, within the magnetic flux rope (MFR) and is found to be bidirectional. The force-field parameterization of the primary GCR fluxes based on ground-based measurements is found to be in very good agreement with spacecraft observations in the sub-GeV range. The GCR anisotropy obtained by fitting the model to ground-based observations is consistent with interplanetary magnetic field observations. The results suggest that the local magnetic field has a substantial axial component that is aligned to the MFR axis, and determines the GCR anisotropy at the typical neutron monitor energies
Diagnosis of cardiac papillary fibroelastoma presenting with acute coronary syndrome and concomitant Salmonella bacteraemia, mimicking aortic endocarditis
Full text linkIntroduction: A case of fibroelastoma of the aortic valve in a patient with acute coronary syndrome has been reported. Cardiac papillary fibroelastomas (PFE) are rare cardiac tumours that are generally benign. In most cases they are incidental findings, their first clinical manifestation is often associated with embolic events. Case presentation: We present the case of a 63-year-old man who experienced coronary embolization without any indications of underlying coronary artery disease. Further investigation led to the identification of the cause of embolization. The concomitant presence of Salmonella bacteraemia, associated with symptoms of gastrointestinal inflammation and elevated inflammation indices, led to the hypothesis of valvular endocarditis. Therefore, a transoesophageal echocardiogram was performed, which confirmed the presence of a mobile, well-demarcated, echo-dense mass identified on the left coronary cusp. Despite the diagnostic uncertainty between fibroelastoma and endocarditic formation, the occurrence of the embolic event and the marked hypermobility we decided that prompt intervention was required. Surgical cleavage of the valve formation was performed, revealing macroscopic morphological characteristics consistent with PFE which was confirmed by the histological finding. Conclusions: This case highlight the importance of a comprehensive diagnostic approach, including transoesophageal echocardiography, in patients with embolic events with no obvious evidence of an embolic causes
Wire-arc additive manufacturing: Process optimization, advancements, in-process data monitoring, and material characterization
Full text linkThis thesis explores the optimization and characterization of Wire Arc Additive Manufacturing (WAAM) for low-carbon steel, aiming to enhance deposition quality, geometrical precision, and material properties. Preliminary experiments established a processing window by analyzing the influence of key process parameters power, travel speed, wire feed speed, and stand-off distance on bead geometry and material properties. Advanced methodologies, such as force air cooling, in-process data monitoring and microstructural analysis, were utilized to evaluate the thermal and mechanical behavior of WAAM-fabricated components
Effect of Dapagliflozin on Ventricular Arrhythmic Events in Heart Failure Patients With an Implantable Cardioverter Defibrillator
Full text linkBackground: The aim of our study was to evaluate the effects of dapagliflozin on the ventricular arrhythmia burden (VAb) in patients with heart failure with reduced ejection fraction (HFrEF) and an implantable cardioverter defibrillator (ICD), correlating the possible reduction in arrhythmic events and ICD therapies with the basal functional capacity, as well as the remodeling parameters induced by treatment. Methods: A total of 117 outpatient ICD patients with a known diagnosis of HFrEF who underwent treatment with dapagliflozin were evaluated according to a prospective observational protocol. VAb (including sustained ventricular tachycardia, non-sustained ventricular tachycardia, ventricular fibrillation, and total ventricular events) and specific ICD therapies (anti-tachycardia pacing (ATP) and ICD shocks) were extrapolated from the devices’ memory (events per patient per month) by comparing events in the observation period before and after the introduction of dapagliflozin. Results: The VAb was significantly reduced after dapagliflozin introduction (2.9 ± 1.8 vs. 4.5 ± 2.0, P = 0.01). The burden of appropriate ATPs was significantly reduced (0.57 ± 0.80 vs. 0.65 ± 0.91, P = 0.03), but not for ICD shocks. In patients with a more advanced functional class, a greater reduction in VAb was observed than in patients with a better initial functional capacity (2.2 ± 0.8 vs. 5.5 ± 1.8, P = 0.001 in the New York Heart Association (NYHA) III/IV group; 3.5 ± 2.1 vs. 4.5 ± 2.2, P = 0.02 in the NYHA I/II group). Considering two independent groups according to reverse remodeling (Δleft ventricular ejection fraction (LVEF) > 15%), a significant reduction in VAb was observed only in those patients who presented significant reverse remodeling (2.5 ± 1.1 vs. 5.1 ± 1.6, P = 0.01). A statistically significant interaction between the variation of total ventricular arrhythmias (VTA) and the basal NYHA class (F(1,115) = 142.25, P < 0.0001, partial η2 = 0.553), as well as between the variation of VTA and the ΔLVEF (F(1,115) = 107.678, P < 0.0001, partial η2 = 0.484) has been demonstrated using a two-way analysis of variance (ANOVA) test. Conclusions: In ICD outpatients with HFrEF, dapagliflozin treatment produces a reduction in arrhythmic ventricular events. This improvement is more evident in patients who have a worse functional class and thus a more precarious hemodynamic state, and in patients who present with significant ventricular reverse remodeling. Therefore, we can hypothesize that the hemodynamic and structural improvements induced by treatment represent, at least in the short-medium term, some of the principal elements justifying the significant reduction in VAb
Valutazione delle vie di signalling indotte dal sistema del complemento nell’instaurarsi del dolore neuropatico: effetti di antagonisti dei recettori C5aR1 e C5aR2
No full textPeripheral neuropathy and hypersensitivity reactions (HSRs), frequently associated with chemotherapy, represent common and debilitating adverse effects linked to the use of paclitaxel as an antineoplastic agent. Evidence indicates that paclitaxel binds to and activates complement component 5a receptors 1 and 2 (C5aR1, C5aR2), a mechanism identified as pivotal in the onset of paclitaxel-induced neuropathy and anaphylaxis. Prior research connecting interleukin-8 (IL-8) to paclitaxel-driven neurotoxicity prompted an investigation into the proteins responsible for IL-8 induction. Molecular docking simulations conducted via the Exscalate platform demonstrated a high binding affinity between paclitaxel and C5aR1 and 2. In vitro studies confirmed that the interaction between paclitaxel and C5aR1 is specific and competitive, leading, in particular for C5aR1, to the activation of intracellular NFκB/P38 signaling and c-Fos pathways. In neuronal F11 cells and rat dorsal root ganglia, C5aR1 blockade reduced neuropathological changes caused by paclitaxel. Similarly, in mice treated with paclitaxel, either genetic deletion of C5aR1 or its pharmacological inhibition significantly ameliorated symptoms of chemotherapy-induced peripheral neuropathy (CIPN), including cold and mechanical allodynia, and minimized chronic pathological alterations in the paw. Furthermore, inhibition of C5aR1 suppressed anaphylactic cytokine release triggered by paclitaxel in macrophages during in vitro experiments and reduced the incidence of HSRs in mouse models. These findings collectively identify C5aR1 as a key mediator in the pathogenesis of paclitaxel-induced CIPN and HSRs and highlight its potential as a therapeutic target for mitigating these severe adverse effects
Recurrent stroke in patients with history of stroke/transient ischemic attack and device-detected atrial fibrillation: A systematic review and meta-analysis
Full text linkIntroduction: Prolonged cardiac monitoring after stroke increases the detection of device-detected atrial fibrillation (DDAF), leading to a clinical dilemma regarding anticoagulation for secondary stroke prevention. While anticoagulation reduces thromboembolic risk in clinical AF, its benefit-risk profile in DDAF remains uncertain. Methods: In this systematic review and meta-analysis, randomized-controlled clinical trials (RCTs) evaluating anticoagulation among patients with DDAF post stroke or transient ischemic attack (TIA) were pooled. The primary efficacy outcome was any stroke recurrence, while stroke or systemic embolism, ischemic stroke recurrence, myocardial infarction, and cardiovascular mortality were assessed as secondary efficacy outcomes. The primary safety outcome was major bleeding, while hemorrhagic stroke and all-cause mortality were assessed as secondary safety outcomes. Results: Two RCTs with 599 patients (294 anticoagulation, 305 no-anticoagulation) were included. Anticoagulation significantly reduced any stroke recurrence (RR: 0.47; 95% CI: 0.23–0.94; p = 0.034; number-needed-to-treat = 34). Anticoagulation lowered the risk of the composite outcome of stroke recurrence and systemic embolism (RR: 0.45; 95% CI: 0.22–0.90; p = 0.023). However, anticoagulation was associated with an increased risk of major bleeding (RR: 2.30; 95% CI: 1.06–4.98; p = 0.035; number-needed-to-harm = 37). There were no differences in ischemic stroke recurrence (RR: 0.53; 95% CI: 0.26–1.09; p = 0.084), myocardial infarction (RR: 0.58; 95% CI: 0.17–1.96; p = 0.379), cardiovascular mortality (RR: 0.68; 95% CI: 0.35–1.34; p = 0.265), hemorrhagic stroke (RR: 0.25; 95% CI: 0.03–2.24; p = 0.217) or all-cause mortality (RR: 0.97; 95% CI: 0.66–1.41; p = 0.857). Discussion: Anticoagulation in DDAF patients with prior stroke/TIA reduces any stroke recurrence but increases major bleeding risk without raising hemorrhagic stroke incidence. This trade-off underscores the need for individualized risk stratification. Conclusions: Anticoagulation lowers any stroke recurrence in DDAF patients post-stroke/TIA but raises major bleeding risk
Unveiling the emotional edge: how fans’ emotional attachment influences the relationships between fanship, fandom, subjective well-being, and attitudinal loyalty
No full textEmotions are hallmarks of more internalised and meaningful sport fan identities. Building on this premise, we use the social identity approach to explore how fans’ emotional attachment affects the relationships between fanship (i.e. personal identification with a team), fandom (i.e. social identification with fellow fans), subjec- tive well-being (SWB), and attitudinal loyalty. We used structural equation modelling to analyse data from fans (N = 571) of two Italian Serie A association football teams. Results highlighted a positive association between fandom and SWB. SWB positively mediated the relationship between fandom and attitudinal loyalty. Moreover, emotional attachment negatively moderated the rela- tionships between fanship and SWB, and between fandom and attitudinal loyalty. These results indicated that high identifiers feel- ing strong emotional attachment to the team displayed lower SWB and attitudinal loyalty toward the team. Practitioners and organisa- tions may benefit from implementing initiatives and programs addressing the side effects of fans’ emotions
Engineering Fair and Efficient Learning-Based Software Systems
Full text linkLearning-based systems – i.e., systems including machine learning (ML) models – are now employed in all aspects of our lives. The wide adoption of these systems has raised several concerns about their quality, as highlighted by the United Nations Sustainability Development Goals and the European Union AI Act. Unlike traditional software systems, learning-based systems employ an additional set of relevant quality properties (such as fairness, explainability, and privacy) that must be addressed.
In this thesis, we focus on two of the most relevant quality properties of these systems—namely, fairness and efficiency—and propose a set of contributions that span different phases of a general learning-based systems development workflow.
Concerning the fairness quality property, we first address a significant lack of fairness-enhancing methods by proposing a novel pre-processing algorithm to improve fairness in both binary and multi-class classification settings. Next, we formally model the workflows for fairness assessment and select the best combination of ML model and fairness-enhancing method. We propose two low-code approaches leveraging these formal models to support data scientists in developing fair learning-based systems. Additionally, motivated by the desire to further support data scientists in the early identification of variables leading to high bias in a system, we performed an extensive empirical evaluation of the ability of dataset structural features—termed bias symptoms—to detect algorithmic bias early, before training a model. Finally, we begin to investigate bias issues of learning-based systems employing Large Language Models (LLMs) and how the fairness of these systems is currently assessed in GitHub projects.
Concerning the efficiency of learning-based systems, we first investigate the ability of existing approaches to estimate the training time of ML models early. This investigation is motivated by the need to assist data scientists in the early selection
of ML models that meet a given training time constraint. Next, we examine the efficiency of LLMs regarding inference time and memory size. First, we conduct a thorough empirical investigation of the impact of LLM compression strategies on
the efficiency and effectiveness of models fine-tuned for software engineering tasks.
From this investigation, we derive a set of recommendations for practitioners and researchers to guide them in selecting the best compression strategy for a given task.
Finally, we propose a novel search-based approach that identifies the optimal hyperparameter setting and prompt structure to reduce the inference time of text-to-image generation models while maintaining high quality in the generated images.
With this thesis, we aim to support data scientists and practitioners in developing fair and efficient learning-based systems and to help standardize some phases of the development workflow