Archivio istituzionale della Ricerca - Università degli Studi di Parma
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GW250114: Testing Hawking’s Area Law and the Kerr Nature of Black Holes
No full textThe gravitational-wave signal GW250114 was observed by the two LIGO detectors with a network matched-filter signal-to-noise ratio of 80. The signal was emitted by the coalescence of two black holes with near-equal masses m_{1}=33.6_{-0.8}^{+1.2}M_{⊙} and m_{2}=32.2_{-1.3}^{+0.8}M_{⊙}, and small spins χ_{1,2}≤0.26 (90% credibility) and negligible eccentricity e≤0.03. Postmerger data excluding the peak region are consistent with the dominant quadrupolar (l=|m|=2) mode of a Kerr black hole and its first overtone. We constrain the modes' frequencies to ±30% of the Kerr spectrum, providing a test of the remnant's Kerr nature. We also examine Hawking's area law, also known as the second law of black hole mechanics, which states that the total area of the black hole event horizons cannot decrease with time. A range of analyses that exclude up to five of the strongest merger cycles confirm that the remnant area is larger than the sum of the initial areas to high credibility
Inter-Hospital Spread of Fluconazole-Resistant C. parapsilosis in Northern Italy: Insights Into Clonal Distribution, Resistance Mechanisms and Biofilm Production
No full textBackground: Starting from 2018 onwards, several outbreaks of fluconazole-resistant C. parapsilosis have been reported in many countries worldwide. Objectives: Here we report a retrospective study on C. parapsilosis blood isolates collected over 7 years (2018–2024) in two hospitals in Northern Italy. Patients/Methods: The study involved 169 C. parapsilosis isolates collected from individual hospitalised patients. We assessed the antifungal susceptibility of the isolates, evaluated the presence of mutations in the ERG11 gene and performed multilocus microsatellite typing to highlight the genetic relatedness of the strains. All isolates were also tested for their ability to produce biofilm. Results: Among the 169 clinical isolates, 124 (73.4%) were classified as fluconazole-resistant C. parapsilosis (FRCP) and 45 (26.6%) as fluconazole-susceptible (FSCP). ERG11 sequencing highlighted that the most frequent mutation in FRCP is the Y132F (118/124, 95.2%). None of the FSCP carried the Y132F. Microsatellite genotyping showed five major clusters and 13 sub-clusters, formed by isolates sharing identical genotypes. Sub-cluster R1 included 96 FRCP carrying the Y132F substitution, isolated from 2018 to 2024 in both hospitals. Interestingly, 99.1% of the FRCP carrying the Y132F mutation were categorised as low biofilm formers, while FRCP carrying other ERG11 mutations were categorised as medium or high biofilm formers. Conclusions: Our results confirmed that Y132F may be mainly responsible for azole resistance in C. parapsilosis and inter-hospital spread. As we found, recent clinical studies indicate that FRCP isolates responsible for severe outbreaks produce thin biofilms. Mutated and therefore resistant strains may exhibit reduced biofilm production as a protective mechanism
Prognostic gene expression signatures for HPV-negative head and neck squamous cell carcinoma
No full textBackground: Head and neck squamous cell carcinoma (HNSCC) is a leading cause of cancer-related deaths worldwide, with HPV-negative cases being particularly aggressive. These cases often show poor prognosis and low responsiveness to radiotherapy. Improved prognostic tools and treatment strategies are needed to enhance outcomes. Aim: To evaluate the prognostic value of various gene expression signatures in predicting survival outcomes in HPV-negative HNSCC patients receiving radiotherapy and to compare their accuracy against the current TNM staging system. Methods: This observational cohort study used data from the European BD2Decide project, systematically analyzing gene expression in loco-regionally advanced, non-metastatic HPV-negative HNSCC patients (stage III-IVa/b) treated with curative radiotherapy (post-operative or definitive) between 2008 and 2017. The primary outcome was overall survival (OS), with secondary outcomes including disease-free survival (DFS), distant metastasis-free survival (DMFS), and loco-regional recurrence-free survival (LRRFS). The prognostic performance of selected gene expression signatures was evaluated using receiver operating characteristic (ROC) curves and hazard ratios (HR) from Cox models. Results: The study included 783 patients, with a median age of 63 years, mostly male (68 %), with significant tobacco (84 %) and alcohol (69 %) exposure. The 172-gene signature (172GS) showed the highest prognostic accuracy, outperforming the TNM system in predicting OS, DFS, DMFS, and LRRFS. Multivariable analysis confirmed its independent prognostic value. Conclusions: The 172GS gene signature offers superior prognostic information compared to TNM staging, supporting its potential use for better risk stratification and personalized treatment planning in HPV-negative HNSCC. Future trials should consider tumor biology and gene signatures for better patient selection. Trial Registration: NCT02832102
Vascular System Formation: an Auxin-Dependent Physiological Process Involved in Plant Organogenesis
No full textThe vascular system is fundamental for land plants, ensuring the long-distance transport of water, nutrients, and signaling molecules. In Arabidopsis thaliana, vascular patterning is tightly regulated by the hormone auxin, which, according to the canalization hypothesis, promotes the formation of self-organizing transport channels via feedback regulation of its own polar transport. Vascular differentiation typically occurs where elevated auxin levels intersect with responsive cell populations.
It is thought that the small yet functionally active apoplastic fraction of Auxin Binding Protein 1 (ABP1) act in this extracellular acidic environment as a receptor mediating some auxin-driven processes such as canalization.
Here, we present preliminary data on the effects of two synthetic urea derivatives: N, N’-bis-(2,3-methylenedioxyphenyl) urea (2,3-MDPU) and 1,3-di(benzo[d]oxazol-5-yl) urea (5-BDPU) on vascular development in cotyledons of Arabidopsis thaliana. Seedlings were grown in vitro under various concentrations of the compounds alone, in mixture with auxin or in single sequential culture of both types of compounds (urea derivative and auxin). When seedlings are cultured in the presence of the compounds alone the vascular pattern is very similar to that of hormone free (HF) condition.
In the simultaneous presence of auxin plus the urea derivatives, the results suggest that these molecules reduce auxin responsiveness and may alter vascular patterning.
By contrast, in the sequential treatments it seems that the last one is responsible for the result.
In addition, molecular docking studies indicate that both 2,3-MDPU and 5-BDPU can potentially bind to the ABP1 receptor in the absence of auxin, with distinct binding energies.
Furthermore, enzymatic assays show that these synthetic urea derivatives inhibit cytokinin oxidase/dehydrogenase (CKX) activity.
Future researches will include:
• a molecular expression analysis of some genes related with vascular differentiation and auxin transport (including the ones that behave as cytokinin-responsive genes).
• an analysis of the endogenous cytokinin content in the presence of the urea derivatives
A Novel Approach to Rockwell and Scratch Adhesion Tests for Hard Coatings Deposited onto Ti6Al4V Substrates
No full textThe paper aims to investigate the failure modes induced by the Rockwell indentation test on Diamond-Like Carbon (DLC)-based and AlCrN coatings deposited on rolled and additively manufactured Ti6Al4V substrates with different surface finishes and subjected to two distinct post-process heat treatments, and the possible correlations with scratch tests. At the magnification required to capture the entire Rockwell imprint, the adhesion class of the investigated DLC-based and AlCrN coatings could be incorrectly classified as HF1. However, higher-magnification observations revealed numerous radial cracks and non-uniformly distributed small delamination areas, changing the adhesion class to HF3. Additionally, roughness values higher than 1 mu m hid the presence of radial cracks, which aligned parallel to the deep dales and high peaks of the roughness profile, as investigated by SEM. Likewise, in the scratch test, the rough surface also made the smallest cracks, formed at the critical load LC1, undetectable. The critical loads for spallation of the coating in the scratch test (LC2, LC3) did not show significant correlation with the number of radial cracks formed during Rockwell indentations. Consequently, a quick Rockwell indentation cannot predict the scratch test results. Finally, both DLC-based and the AlCrN coatings exhibited good adhesion to Ti6Al4V substrates, regardless of the microstructure and surface finish of the titanium substrates. SEM-FIB observations revealed that the cracks formed during Rockwell indentation and scratch tests were deflected longitudinally within the underlying layers of the DLC-based coating and in the bottom part of the AlCrN coating, where the N concentration was higher
Children's and adolescents' lifestyle factors associated with physical activity in five Mediterranean countries: the DELICIOUS project
No full textBackground Physical activity in children and adolescents represents one of the most important lifestyle factors to determine current and future health.Aim The aim of the study is to assess the lifestyle and dietary factors linked to physical activity in younger populations across five countries in the Mediterranean region.Design A total of 2,011 parents of children and adolescents (age range 6-17 years) participating to a preliminary survey of the DELICIOUS project were investigated to determine children's adequate physical activity level (identified using the short form of the international physical activity questionnaire) as well as diet quality parameters [measured as Youth-Healthy Eating Index (Y-HEI)] and eating and lifestyle factors (i.e., meal habits, sleep duration, screen time, etc.). Logistic regression analyses were performed to assess the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between variables of interest.Results Younger children of younger parents currently working had higher rates and probability to have adequate physical activity. Multivariate analysis showed that children and adolescents who had breakfast (OR = 1.88, 95% CI: 1.38, 2.56) and often ate with their family (OR = 1.80, 95% CI: 0.90, 3.61) were more likely to have an adequate level of physical activity. Children and adolescents who reported a sleep duration (8-10 h) closest to the recommended one were significantly more likely to achieve adequate levels of physical activity (OR = 1.88, 95% CI: 1.38, 2.56). Conversely, those with more than 4 h of daily screen time were less likely to engage in adequate physical activity (OR = 0.77, 95% CI: 0.54, 1.10). Furthermore, children and adolescents in the highest tertile of YEHI scores showed a 60% greater likelihood of engaging in adequate physical activity (OR = 1.60, 95% CI: 1.27, 2.01).Conclusion These results emphasize the importance of promoting healthy diet and lifestyle habits, including structured and high quality shared meals, sufficient sleep, and screen time moderation, as key strategies to support active behaviors in younger populations. Future interventions should focus on reinforcing these behaviors through parental guidance and community-based initiatives to foster lifelong healthy habits
Localized implicit iterative shifting to improve particle distribution in Smoothed Particle Hydrodynamics
No full textThis study presents a novel Implicit Iterative Particle Shifting method designed to enhance the accuracy of Smoothed Particle Hydrodynamics (SPH) simulations by improving particle distribution through the solution of a linear system of equations. The proposed approach addresses key limitations of existing techniques, namely distribution instability and lack of control over maximum particle displacement by accounting for the contribution of neighboring particles on a given particle when constructing the linear system. The method also imposes a constraint on the shifting magnitude, allowing for better control of particle movement and improved distribution stability also in presence of free surface. To reduce computational cost, a localization procedure has been introduced that restricts particle shifting to regions where it is necessary. The effectiveness of the method is demonstrated through a series of benchmark tests, including the Taylor-Green vortex, a moving square box, an oscillating droplet, and a dam break flow. The results show substantial improvements in the uniformity of the particle distribution, computational efficiency, and simulation accuracy compared to established methods
Preoperative Pelvic Muscle Training for Continence Recovery After Prostatectomy: Yet Another Meta‐Analysis?
No full textIntroduction: Urinary incontinence is a common complication after radical prostatectomy. Several meta-analyses have evaluated the effectiveness of pelvic floor muscle training (PFMT) for continence recovery, but their findings are inconsistent, and not all include all relevant studies. This meta-analysis aims to address these gaps. Objectives: The study aims to summarize evidence on the effectiveness of preoperative PFMT, with or without biofeedback, on continence recovery post-prostatectomy. Materials and Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. The PICO framework was used: Patients undergoing radical prostatectomy, Intervention: preoperative PFMT, Comparison: any postoperative intervention or monitoring, Outcome: continence recovery. Studies were sourced from PubMed, CINAHL, Scopus, Web of Science, and PEdro. Quality was assessed using the PEdro scale, and statistical analysis was performed using a random effect model. Results: Six studies were included. Preoperative PFMT did not significantly improve continence recovery 1 month post-surgery (odds-ratio 2.01, 95% CI [0.94–4.31], p = 0.37). However, a significant improvement was observed 3 months post-surgery (odds-ratio 1.52, 95% CI [1.05–2.20], p = 0.03). No significant differences were found at 6 months (odds-ratio 1.28, 95% CI [0.85–1.94], p = 0.95) and twelve months (odds-ratio 0.73, 95% CI [0.43–1.23], p = 0.32). Conclusions: Preoperative PFMT may improve continence recovery 3 months post-surgery but not at one, six, or twelve months. The study highlights the need for standardized assessment criteria and further research on robotic-assisted prostatectomy. The innovative aspect of this study lies in its conservative inclusion criteria and focus on preoperative PFMT's potential benefits. Clinical Trial Registration: Not applicable. This study did not require clinical trial registration because it is a systematic review and meta-analysis of previously published studies
Traditional/ethnic food preparations from medicinal fruits of Egypt
No full textThis chapter explores Egypt’s rich cultural, agricultural, and culinary heritage, shaped by its geographic location and ancient civilization. It delves into the historical and contemporary dietary practices of Egypt, highlighting the significance of plant-based foods in ancient times and their connection to health and spirituality. This chapter emphasizes the ethnobotanical tradition of using medicinal plants and fruits, such as dates, grapes, jujube, and baobab, which have played a key role in both nutrition and traditional medicine for millennia. Additionally, it addresses the growing global interest in herbal medicine and the potential of Egypt’s medicinal plants in modern health markets. This chapter underscores the importance of preserving Egypt’s culinary traditions and biodiversity for future generations, as well as the value of bridging ancient practices with modern scientific research
