IRIS Università degli Studi dell'Aquila
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Use of cover data to model species abundance distributions through continuous probability functions
Get PDFSpecies abundance distribution (SAD) models describe the abundances of the species within ecological communities. SAD modelling has been developed using frequency distributions that require the use of count data (number of individuals). However, many organisms, such as most plants, cannot be counted. Instead, abundance is estimated using cover values. We show here how SAD approaches conceived for modelling frequency distributions based on counts can be modified to deal with continuous distributions and provide an application using relative plant cover as a continuous measure of abundance. We applied several SAD models using continuous probability functions to investigate how plant SADs changed along a wide (2,500 m) elevational gradient in the Alborz Mountains (Iran). We found that most communities were adequately fitted by the Weibull distribution, whose parameters changed along the gradient in response to the interplay between biotic and environmental filtering processes. The use of continuous probability functions in SAD modelling should be encouraged in research dealing with plant communities and other organisms for which counting individuals is theoretically or practically impossible
Detecting quasidegenerate ground states in topological models via the variational quantum eigensolver
No full textWe study the exact ground states of the Su-Schrieffer-Heeger open chain and of the Kitaev open chain, using the variational quantum eigensolver (VQE) algorithm. These models host symmetry-protected topological phases, characterized by edge modes with vanishing single-particle energy in the thermodynamic limit. The same fact prevents the standard VQE algorithm from converging to the correct ground state for finite chains, since it is quasidegenerate in energy with other many-body states. Notably, this quasidegeneracy cannot be removed by small perturbations, as in typical spin systems. We address this issue by imposing appropriate constraints on the VQE evolution and constructing appropriate variational circuits, to restrict the probed portion of the Hilbert space along the same evolution. These constraints stem from general properties both of the topological phases and of the studied Hamiltonians. In this way, the improved VQE algorithm achieves an accurate convergence to the exact ground states in each phase. The present approach promises large applicability, also to realistic systems with different topologies and/or not easily removable degeneracies, thanks to the very high fidelity achievable also on systems with a relatively high number of qubits
fRAme: an evaluation framework for human augmentation or replacement by autonomous intelligent systems
Get PDFThe Association of Lipoprotein(a) and Stroke Recurrence: A Systematic Review and Meta-Analysis
Get PDFBackground and Purpose Lipoprotein(a) [Lp(a)] is a lipoprotein structurally similar to low-density lipoprotein and is considered a genetically determined risk factor for cardiovascular disease. Although Lp(a) has been linked to ischemic stroke, its role in secondary stroke prevention, particularly in stroke recurrence, remains unclear. Methods A systematic search of MEDLINE and Scopus databases was conducted to identify randomized controlled trials (RCTs) and observational studies reporting Lp(a) levels in patients with ischemic stroke or transient ischemic attack. The primary outcome was stroke recurrence, and secondary outcomes included poor functional outcome, all-cause mortality, and recurrent vascular events. Pooled odds ratios (ORs) were calculated using a random-effects model. Results A total of 12 studies, including one RCT post hoc analysis and 11 observational studies, comprising 17,903 patients (mean age 63 years, 38% female), were included. Elevated Lp(a) levels were significantly associated with increased stroke recurrence (OR: 1.69; 95% confidence interval [CI]: 1.09–2.63; P=0.020) and poor functional outcome (OR: 2.09; 95% CI: 1.40–3.11; P<0.001). No significant associations were found between Lp(a) levels and all-cause mortality (OR: 2.20; 95% CI: 0.89–5.43; P=0.088) or recurrent vascular events (OR: 2.66; 95% CI: 0.95–7.44; P=0.063). Conclusion Elevated Lp(a) levels are linked to increased stroke recurrence and poor functional outcome in stroke patients. Lp(a) may represent a novel therapeutic target in secondary stroke prevention in addition to a promising biomarker
Cytotoxicity of Printed Aligners: A Systematic Review
Get PDFBackground/Objectives: The capability of printing aligners directly, eliminating the need for a dental model or thermoforming, represents a significant advancement in aligner therapy. This review aimed to assess the cytotoxicity of 3D-printed aligners to clarify their safety profile, given their growing clinical use. Methods: An electronic literature search was independently conducted by two reviewers up to February 2025 across PubMed, Scopus, and Web of Science. After a thorough selection process, five in vitro studies were included. The quality and risk of bias were evaluated using the QUIN tool. Results: Five studies were included in the systematic review, four of which used TC-85 resin and one TA-28. Two reported no cytotoxic effects. Mild cytotoxicity was observed in one study using UV and heat post-curing, while another reported increased cytotoxicity with extended UV/nitrogen curing. However, notable heterogeneity was present among the studies in terms of the experimental protocols, the cell lines used, and the outcome measures. Conclusions: The cytotoxicity of printed aligners appears to be influenced by post-curing duration and system type, highlighting the importance of strict adherence to manufacturers’ protocols. Nevertheless, due to the limited number of studies and methodological variability, definitive conclusions cannot yet be drawn. Further clinical and standardised in vitro studies are needed to better assess the biocompatibility of 3D-printed aligners
Towards early detection of algorithmic bias from dataset’s bias symptoms: An empirical study
No full textUn'ars poetica cristiana? Paolino di Nola e il protrepticon a Giovio
No full textIl saggio propone una rilettura complessiva del protrettico con
cui Paolino attorno al 400 esorta Giovio, cultore di interessi filosofici e letterari pagani, a dedicarsi alla poesia cristiana. Le idealità di Paolino sono esplicitate nella cornice del componimento: una poesia cristocentrica nei contenuti e nell’ispirazione, che non rinunci a contemperare retaggio della tradizione classica e proclamazione del messaggio cristiano, si configura come prolungamento e inveramento della Scrittura, strumento capace di contribuire concretamente alla progressione verso Dio non solo del poeta, ma anche dei suoi lettori. La versificazione, nella sezione centrale del carme, di contenuti scritturali vetero- e neotestamentari (e.g. cosmogonia, prologo del vangelo di Giovanni, vicenda di Giona) non intende solo confutare le posizioni filosofiche di Giovio, ma anche
delineare un programma di poesia biblica offrendo, in scala ridotta, uno specimen
della pratica poetica che Paolino propone al destinatario e delle possibilità e potenzialità ad essa connesse; in tal modo risulta convalidata per il carme a Giovio la definizione di ars poetica cristiana
Euclid I. Overview of the Euclid mission
No full textThe current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. Euclid is a medium-class mission in the Cosmic Vision 2015-2025 programme of the European Space Agency (ESA) that will provide high-resolution optical imaging, as well as near-infrared imaging and spectroscopy, over about 14 000 deg(2) of extragalactic sky. In addition to accurate weak lensing and clustering measurements that probe structure formation over half of the age of the Universe, its primary probes for cosmology, these exquisite data will enable a wide range of science. This paper provides a high-level overview of the mission, summarising the survey characteristics, the various data-processing steps, and data products. We also highlight the main science objectives and expected performance
