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Energy decay for evolution equations with glassy type memory
No full textIn this paper, we address the question of estimating the energy decay of integrodifferential evolution equations with glassy memory. This class of memory kernel was not analyzed in previous studies. Moreover, a detailed analysis provides an explicit estimate of the connection between the kernel function’s decay constant and the energy’s decay constant
Periodic and aperiodic electroencephalographic rhythms during vigilance transitions in Alzheimer's disease mild cognitive impairment
No full textAlzheimer's disease (AD) dementia is associated with marked disruptions in resting-state eyes-closed electroencephalographic (rsEEG) rhythms, particularly in the periodic alpha band (8–12 Hz), suggesting impaired vigilance regulation. In contrast, the aperiodic rsEEG component, reflecting global cortical arousal, has been reported to remain unchanged. This exploratory study examined periodic and aperiodic EEG activity in patients with mild cognitive impairment due to AD (ADMCI) during transitions from quiet wakefulness to light sleep. EEG datasets (∼30 min) from 19 ADMCI patients and 18 matched cognitively unimpaired older adults (control) were analyzed. Vigilance stages were scored using a reduced version of Hori's system, distinguishing the alpha-dominant wakefulness stage and the theta-dominant light sleep (ripples) stage. EEG spectra were parameterized using the specparam algorithm. ADMCI participants showed reduced reactivity of individual alpha power between the wakefulness and ripples stages compared to the control group. Conversely, both groups exhibited comparable increases in fronto-central theta power and steepening of the aperiodic slope and offset. No group differences emerged in aperiodic exponent and offset, although statistical power was limited by modest sample size. Overall, EEG alpha rhythms reflecting vigilance regulation are disrupted in prodromal AD, while periodic and aperiodic signatures of sleep onset are relatively preserved, suggesting selective vulnerability of attentional thalamocortical systems
Liquidity, stock valuation metrics, and the entrepreneurial sector
No full textPurpose – This paper aims to investigate the role of stock liquidity in valuation metrics through market
multiples by assessing how liquidity affects key valuation metrics such as enterprise value to sales (EV/Sales),
enterprise value to EBITDA (EV/EBITDA), price to book value (P/BV) and price to earnings (P/E) in the
European market. Furthermore, the moderating role played by the entrepreneurial context – represented by the
micro, small and medium-sized enterprise (MSME) status – is tested.
Design/methodology/approach – The study applies an empirical analysis to a sample of European listed firms.
Multivariate analysis is used to assess the direct impact of liquidity (proxied by the bid-ask spread) on valuation
multiples, thereby incorporating both company fundamentals and market behaviour. LASSO regression is
employed to confirm the robustness.
Findings – Results confirm a positive relationship between liquidity and market multiples, indicating that higher
stock liquidity leads to an increase in overall valuation. Moreover, the moderation analysis indicates that this
“positive liquidity effect” is most amplified among listed MSMEs, suggesting a potential distorting effect of
market metrics among this category of companies. The analysis particularly highlights how entrepreneurial
ventures may display stronger liquidity-valuation links.
Research limitations/implications – Findings advance knowledge on the liquidity-value debate by adding
insights based on the entrepreneurial light. They also provide practical implications for investors, managers and
financial analysts, regarding potential liquidity-distorting effects on valuation metrics.
Originality/value – This paper contributes to the business and finance fields, considering for the first time the
moderating role played by MSME status
FCC-ee collimation system design
No full textThe Future Circular electron–positron Collider (FCC-ee) is a proposed highest-energy, luminosity-frontier lepton collider designed to enable precision measurements in the electroweak and Higgs sectors. The machine is being designed to operate in four distinct running modes, with beam energies of 45.6 GeV, 80 GeV, 120 GeV, and 182.5 GeV, optimized for the production of different particles (Z, W , H, and tt̄). Owing to beam intensities far exceeding those of any previous lepton collider, required to achieve unprecedented luminosities, the FCC-ee beams will feature stored beam energies up to 17.7 MJ—about two orders of magnitude higher than the current state-of-the-art lepton collider, SuperKEKB, and comparable to the stored beam energy of the heavy-ion beams in the Large Hadron Collider (LHC).
The FCC-ee thus represents a new operational regime for lepton colliders, where the combination of high stored beam energy and ultra-low emittances makes the beams highly destructive. This regime is extremely challenging from a beam-collimation standpoint. At the FCC-ee, a beam collimation system is indispensable—not only to reduce beam-induced backgrounds in the experimental detectors, as in previous lepton colliders, but also to protect the machine itself from unavoidable beam losses. A robust and efficient beam collimation system is therefore essential both to minimize detector backgrounds and to ensure machine protection, operational safety, and sustained availability as the FCC-ee progresses toward its integrated luminosity goals.
This thesis presents a comprehensive design study of a beam collimation system for the FCC-ee, combining analytical studies and advanced simulations to evaluate performance under a wide range of beam-loss scenarios expected during regular operation as well as abnormal conditions. In this work, dedicated simulation routines have been developed to model beam losses from beam–residual gas scattering and Touschek scattering. The simulation tools and developed routines have been benchmarked against measured data from the SuperKEKB collider, as well as with beam loss data from the LHC, reproducing observed beam-induced background trends or beam loss patterns with
excellent accuracy. This validation demonstrates their reliability for predicting collimation performance not only at the FCC-ee but also at other existing or future colliders.
The outcome of this thesis is a proposed multi-stage beam collimation system for the FCC-ee, included in the machine’s baseline design. More importantly, this work provides a comprehensive documentation of the principles and methods for developing a robust and efficient collimation system for any future electron–positron collider. The methodologies, tools, and design strategies developed here provide a solid foundation for future optimization of the FCC-ee collimation system and will play a key role in the forthcoming technical design phase of the machine. Finally, complementary studies on a crystal collimation system are presented, demonstrating its promising potential and identifying it as an interesting alternative to a traditional collimation system
Supercritical carbon dioxide-based approach for the recovery and purification of polyhydroxyalkanoates from mixed microbial cultures: A green approach for bioplastics production
No full textThe widespread use of petroleum-based plastics has significant environmental consequences, including greenhouse gas emissions and long-term contamination of marine and terrestrial habitats. In contrast, bioplastics are a class of biopolymers, widely considered as the main alternative to conventional non-degradable plastics. Polyhydroxyalkanoates (PHAs) are a class of biodegradable polymers that have the potential to replace conventional polymers thanks to their similar properties. PHAs are currently produced using fermentation technologies, which require post-extraction purification procedures as well as the use of organic solvents for the removal of residual fermentation media to obtain high-quality products (e.g., medical devices). In the present study, supercritical CO2-extraction (scCO2) was employed as a green technology to selectively recover and purify PHAs from mixed microbial cultures using different multi-step protocols, including: the use of co-solvents (methanol, water and phosphate buffer solution) inside the scCO2 cell, pre- and post-treatment of the biomass (with enzymes and H2O2), employing different times (2 h to 4 h), temperatures (35 °C to 40 °C) and pressures (20 MPa to 35 MPa) for the scCO2-treatment. Among the tested protocols, the post-treatment of biomass with H2O2 and trypsin (scCO2-H2O2-trypsin) resulted in the highest PHA purity and recovery with 97.2 % and 97.3 %, respectively. The results demonstrate the importance of scCO2-based techniques as a valid alternative to conventional methods that use chlorinated organic solvents. This highlights the importance of green technologies as a turning point in the industrial production of biopolymers starting from a complex biomass feedstock
Domain-specific phenotypic profiles in RAF1-related Noonan syndrome
No full textPathogenic variants in RAF1 are a common cause of Noonan syndrome (NS), accounting for approximately 5% of cases. Nonetheless, RAF1-related NS is often associated with severe clinical features, particularly hypertrophic cardiomyopathy (HCM). Although initial studies highlighted the occurrence of genotype-phenotype correlations, a comprehensive analysis specifically focused on RAF1 variants is still lacking. We conducted a retrospective observational study combining newly collected cases of RAF1-related NS from a national multicenter retrospective cohort with systematically reviewed cases from a literature search. Variants were classified by protein domain, while the most recurrent variant, p.Ser257Leu, was analyzed separately to assess variant- and domain-specific phenotype correlations. A total of 203 cases were included. Variants in the CR2 domain accounted for 83% of cases, with p.Ser257Leu alone representing 53%. HCM was observed in 80.1% of affected individuals, confirming its role as the predominant cardiac manifestation in RAF1-related NS; neurodevelopmental features were reported in 44.5% of patients. The prevalence of clinical features varied significantly according to variant location. HCM was markedly more frequently associated with CR2 variants (89.4%) and in subjects heterozygous for the p.Ser257Leu change (94.2%) compared with non-CR2 variants (37.1%). Conversely, neurodevelopmental features were more common in patients with non-CR2 variants (69.2%) than in those with CR2 variants (38.2%) or p.Ser257Leu (29.4%). CR2 and p.Ser257Leu variants were associated with earlier age at diagnosis and increased mortality. Our findings confirm and document more comprehensively domain- and variant-specific phenotypes in RAF1-related NS, emphasizing the importance of variant-level interpretation in clinical management and genetic counseling
Development of a new telemedicine tool for the screening of thyroid eye disease
No full textIntroduction
Graves' disease (GD) is the most common cause of hyperthyroidism, and its primary extrathyroidal manifestation is Thyroid Eye Disease (TED), an autoimmune orbitopathy that significantly impairs quality of life. Early detection of TED is crucial for timely intervention, but access to specialist ophthalmological assessment can be limited. Telemedicine presents a potential solution for remote screening and monitoring, yet validated tools for TED are lacking. This study aimed to develop and validate a telemedicine-based pathway, incorporating a novel study-specific questionnaire (SSQ) and patient-provided photographs, to accurately screen for TED in patients with GD.
Materials and Methods
In this paired diagnostic accuracy study, 218 consecutive patients with GD were recruited from a tertiary care center. Participants completed a remote telemedicine assessment, which included the validated Graves' Ophthalmopathy Quality of Life (GO-QoL) questionnaire and an SSQ designed to remotely assess the Clinical Activity Score (CAS) and Gorman score for diplopia. Patients also uploaded facial photographs. All participants subsequently underwent a comprehensive, masked in-person ophthalmological examination, which served as the reference standard for diagnosing TED according to EUGOGO guidelines. The diagnostic accuracy of the telemedicine tools was evaluated using receiver operating characteristic (ROC) curve analysis, and agreement between remote and in-person scores was assessed using Bland-Altman analysis, intraclass correlation coefficients (ICC), and weighted kappa.
Results
Of the 218 participants, 65 (29.82%) were diagnosed with TED (TED+) and 153 (70.18%) were not (TED−). Patients in the TED+ group reported a significantly lower quality of life (mean GO-QoL score: 51.54 ± 13.51) compared to the TED− group (94.68 ± 7.66; p < 0.001). The remote assessments of diplopia (Tele-Gorman) and clinical activity (Tele-CAS) showed good-to-substantial agreement with in-person findings (ICC = 0.724 and 0.771, respectively), though a small but significant underestimation was noted at higher severity levels. The SSQ alone demonstrated excellent diagnostic performance, with an Area Under the Curve (AUC) of 0.93. At an optimal cut-off of ≥4, the SSQ achieved a sensitivity of 90.77% and a specificity of 95.42%. Incorporating photographic analysis (TeleTED score) yielded a marginally higher AUC of 0.94, with a sensitivity of 89.23% and a specificity of 98.69% at a cut-off of ≥5.
Conclusions
A streamlined telemedicine pathway, centered on a purpose-designed questionnaire, can triage patients with Graves' disease for TED with high discriminative accuracy. The tool demonstrates good agreement with in-person clinical grading, making it a reliable instrument for remote screening. This approach is immediately translatable into a high-sensitivity pre-screening protocol that can help preserve healthcare resources and accelerate access to specialist care for patients at genuine risk of developing thyroid eye disease
The Income Capitalization Approach for property valuation: a critical assessment of opportunities and limitations
No full textThe article provides a critical analysis of income-based methods used in real estate valuation (the Income Capitalization Approach – ICA) with the aim of highlighting their theoretical foundations, operational applications, strengths, and limitations within increasingly complex real estate markets. The study adopts a comparative approach based on an examination of the theoretical assumptions and operational procedures underpinning the methodologies included in the ICA. Critical variables are evaluated, such as the definition of cash flows, the determination of capitalization and discount rates, the estimation of terminal value, and the reliability of market inputs. The investigation integrates insights from international literature and reflections derived from professional practice. The critical assessment shows that Direct Capitalization (DC) remains effective in stable and transparent markets, but proves rigid in contexts characterized by irregular income patterns, cyclicality, or limited information availability. Discounted Cash Flow (DCF) analysis emerges as a more flexible and theoretically robust methodology capable of modeling complex scenarios; however, its effectiveness is strongly dependent on the quality of the assumptions adopted and on market predictability.
The article offers an interpretative framework that can guide both academic research and professional practice toward a more informed, transparent, and critical use of income-based valuation tools
Design and optimization of advanced nanophotonic devices based on plasmonic and optical soliton technology
No full textThis doctoral thesis presents a comprehensive investigation into the design, optimization, and synergistic
integration of novel nanophotonic devices, aimed at overcoming fundamental, long-standing
limitations in plasmonics and nonlinear optics. The research confronts three critical challenges that
obstruct the development of chip-scale integrated plasmonic devices: inefficient light coupling, debilitating
propagation loss of Surface Plasmon Polaritons (SPPs), and the inherent instability of
reconfigurable waveguides. By combining the subwavelength confinement of plasmonics with the
ultra-low-loss photorefractive soliton interconnections, this work provides a complete technological
"blueprint" for a new class of hybrid, adaptive nanophotonic systems.
The principal contributions of this research are fourfold. First, a new class of "Bilayered Conventional
and Buried Grating" (BCBG) couplers for SPPs is proposed and numerically optimized.
These structures are shown to solve the critical input problem by achieving a high coupling efficiency
of approximately 30.3% while simultaneously suppressing parasitic light transmission to an
unprecedented low of 0.3%, thereby eliminating a key source of noise and crosstalk in dense circuits.
Second, a novel "nonlinearly-assisted propagation" paradigm is introduced to circumvent the
high ohmic losses of short-wavelength SPPs. We demonstrate that by generating a 532 nm SPP
via second-harmonic generation from a low-loss, long-propagating 1064 nm fundamental SPP, the
effective propagation distance of the visible-light SPP can be extended by a factor of approximately
30 by CW and 120 by medium short pulse, opening the door to practical visible-light plasmonics
and sensing.
The design of the core hybrid architecture: an ultra-broadband "SPP-to-soliton-to-SPP" interconnect.
This system is designed to solve the long-distance routing problem by converting a
nanoscale SPP into an ultra-low-loss solitonic waveguide (0.04-0.07 dB/cm) that bridges centimeterscale
distances. A key innovation is the use of a multilayer ITO structure to control SPP diffraction
via Fabry-Perot resonance, ensuring an efficient launch of the soliton.
The critical barrier of instability in reconfigurable waveguides is solved. We discover and analyze
a novel "charge anchoring" mechanism, which, by using a new propagation geometry with a cathode
at the output, leverages electrostatic boundary conditions to completely suppress the detrimental
self-bending of photorefractive solitons. This breakthrough transforms the soliton from an unstable
phenomenon into a perfectly stable, immobilized, and spatially addressable waveguide.
Finally, this thesis demonstrates the power of this stable solitonic platform for advanced nonlinear
applications. We show, through experiment and simulation, that the self-formed solitonic
waveguide enables highly efficient Parametric Down-Conversion, even far from traditional phasematching
conditions. This is achieved through a phase-locking mechanism that ensures perfect
mode-overlap and interaction.
Collectively, these contributions establish a viable pathway for the first reconfigurable, low-loss,
solitonic-plasmonic interconnects capable of routing signals over centimeter-scale distances between
nanoscale components. This work lays the essential groundwork for future advancements in on-chip
optical networks, neuromorphic computing, and reconfigurable quantum light sources