Archivio Istituzionale della Ricerca - Università degli Studi di Pavia
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Rare uniparental lineages reveal external ancestries in the gene pool of the Italian linguistic enclave of Grecìa Salentina
No full textCan language be a valuable predictor of genetic diversity even at the level of extremely circumscribed areas of linguistic diversity? We report on the analysis of mtDNA and NRY variation extracted from the whole-genome sequencing of 27 natives of Grecìa Salentina, a geographic area in southern Italy home to a historic Greek-speaking community. With respect to mtDNA, we found similarities with samples from Central Italy and Eastern Balkan, mainly because of the high haplogroups N, K and J1 frequencies. Detailed phylogeographic analyses of these haplogroups reveal instances of Grecìa Salentina-specific lineages. With respect to the NRY, we find similarities with other samples from southern Italy, Anatolia and the Middle East, because of the overwhelming frequency of haplogroup J2a. The new J2a lineages, many of which are specific to Grecìa Salentina, greatly expand the phylogeny of the haplogroup. Haplogroup R1a is also overrepresented, with a new lineage belonging to the GML6 subclade, which is common in the Western Balkans. All the above haplogroups were long recognized as markers of post-Neolithic East-to-West movements through the Balkan Peninsula by land or off its coasts by sea. We conclude that the peculiar component detected in the Grecìa Salentina gene pool is the result of past immigration. Specifically, there was a demic contribution of both sexes, which foreshadows the build-up of an entire community, and subsequent dilution in the surrounding gene pool by admixture occurred only to a limited extent. These results add a genomic dimension to our knowledge of the identity of the Greek-speaking community settled in Grecìa Salentina. To date, the peculiarity of the Grecìa Salentina population was only its linguistic identity, but we now show that it is also supported by a genetic component. The more general hypothesis of a connection between the demic and linguistic structure of the area can now be tested by comparing the genetics of Grecìa Salentina to those of other linguistic enclaves of Balkan origin in southern Italy
Why is the estimation of metaorder impact with public market data so challenging?
No full textEstimating market impact and transaction costs of large trades (metaorders) is a very important topic in finance. However, using models of price and trade based on public market data provide average price trajectories which are qualitatively different from what is observed during real metaorder executions: the price increases linearly, rather than in a concave way, during the execution and the amount of reversion after its end is very limited. We claim that this is a generic phenomenon due to the fact that even sophisticated statistical models are unable to correctly describe the origin of the autocorrelation of the order flow. We propose a modified Transient Impact Model which provides more realistic trajectories by assuming that only a fraction of the metaorder trading triggers market order flow. Interestingly, in our model there is a critical condition on the kernels of the price and order flow equations in which market impact becomes permanent
Biochar-based “in-vial” stir bar sorptive microextraction for a greener determination of steroid hormones in saliva
No full textAdvancing Neuropediatric Rare Disease Diagnosis Through Clinical Genome Sequencing
No full textBackground: Many patients with rare genetic diseases remain undiagnosed or receive a molecular diagnosis only after years. In this study, we want to evaluate the usefulness of clinical genome sequencing (cGS) in a cohort of complex neuropediatric patients with undiagnosed rare genetic diseases. Methods: Between 2018 and 2022, our Medical Genetics Units in Torino, Trieste and Pavia partnered with the iHope program, a philanthropic initiative by Illumina Inc., with the aim of offering family-based cGS within the Italian National Health Service (Servizio Sanitario Nazionale) diagnostic process. A multidisciplinary team of pediatricians, clinical geneticists, and molecular biologists selected 64 cases. Inclusion criteria consisted of suspicion of an ultra-rare monogenic disease and at least one negative result from a first-tier genetic test. Results: A definitive molecular diagnosis was achieved in 57.8% of the patients. All patients and families underwent clinical re-evaluation to assess the diagnostic relevance of the laboratory findings, which led us to reclassify 10 variants of unknown significance as responsible for the probands' phenotypes. Diagnoses impacted patients' management, enabling palliative care referrals, avoiding unnecessary invasive tests, and guiding follow-up treatments. Conclusions: Our study confirms that the use of cGS in a rare disease setting increased the diagnostic yield even in complex cases where other methods had previously failed. We speculate that introducing cGS as first-tier test within the Italian Servizio Sanitario Nazionale might offer both diagnostic and economic advantages
Italian guidelines for the use of digital breast tomosynthesis in breast cancer screening programmes: GRADE-ADOLOPMENT of the European guidelines
No full textNative plants for ecological restoration in Italy: taxonomy and species selection
No full textGrasslands represent one of the most widespread and ecologically significant terrestrial biomes, covering roughly 30-40% of Earth’s land surface and providing a variety of vital ecosystem services. Among their dominant species, perennial grasses are particularly important for ecosystem, consisting often in the keystone and dominant species of these habitats, and partaking a critical role in the correct functioning of the vast majority of these ecosystemic services. Because of their undiscussed importance, perennial grasses have been the main focus when talking ecological restoration and protection of grasslands.
Within the grass family (Poaceae), Festuca L. is a globally distributed and ecologically diverse genus, with fine-leaved taxa (Festuca sect. Festuca) playing central roles in the composition of Eurasian steppes, alpine meadows, and semi-natural grasslands of Europe. Despite their ecological importance, the taxonomy of Festuca remains one of the most challenging in the grass family, with morphological convergence, polyploidy, hybridization, and incomplete lineage sorting leading to long-standing uncertainty in species delimitation. These taxonomic criticalities are not to be overlooked as they go far beyond the disciplines of taxonomy and systematic botany. In fact, this type of knowledge is fundamental to many other seemingly unrelated disciplines, as reliable species identification is fundamental to ecological restoration, conservation planning, and biodiversity monitoring.
This PhD project focuses on the Festuca stricta-valesiaca complex, a particularly intricate group of fine-leaved fescues distributed across Eurasia, focusing on the taxa that naturally occurs in the Alps and Apennines. Taxa within this complex have been variously interpreted as species, subspecies, or hybrids, and their boundaries remain controversial. The aim of the study is to integrate morphological, cytogenetic, and molecular approaches to achieve a clearer understanding of taxa boundaries, evolutionary relationships, and nomenclatural stability within the group, for further application in ecological restoration projects.
To this end, 987 individuals from 66 populations were collected across the Alps and Apennines, supplemented by herbarium research and historical type material consultation in different European herbaria. Morphological variation was quantified using 32 characters from vegetative, reproductive, and anatomical traits, with analyses conducted through ordination and canonical discriminant methods. Flow cytometry was employed on fresh and recent herbarium material to assess ploidy levels and cytotype variation across populations. Finally, for a limited number of individuals, genomic data were generated using ddRAD sequencing, allowing phylogenetic inference of relationships within the complex and between taxa.
The analyses revealed clear differentiation between taxa with lower ploidy (F. valesiaca, F. sp. nova) and the more complex group of polyploid taxa (hexaploids, octoploids, decaploids), which showed in some cases morphological overlap but also evidence of reproductive isolation. Several diagnostic morphological characters, particularly leaf cross-section anatomy, scabridity, spikelets elements size and pubescence, were confirmed as useful for discrimination, though many boundaries remain blurred by gradual variation and shared traits. Flow cytometry confirmed known ploidy levels but also identified unexpected cytotypes in the Apennines, suggesting overlooked diversity or some polyploidization events. Phylogenomic analyses showed promising early results and laid a solid base for a more complete study of the group in the future.Grasslands represent one of the most widespread and ecologically significant terrestrial biomes, covering roughly 30-40% of Earth’s land surface and providing a variety of vital ecosystem services. Among their dominant species, perennial grasses are particularly important for ecosystem, consisting often in the keystone and dominant species of these habitats, and partaking a critical role in the correct functioning of the vast majority of these ecosystemic services. Because of their undiscussed importance, perennial grasses have been the main focus when talking ecological restoration and protection of grasslands.
Within the grass family (Poaceae), Festuca L. is a globally distributed and ecologically diverse genus, with fine-leaved taxa (Festuca sect. Festuca) playing central roles in the composition of Eurasian steppes, alpine meadows, and semi-natural grasslands of Europe. Despite their ecological importance, the taxonomy of Festuca remains one of the most challenging in the grass family, with morphological convergence, polyploidy, hybridization, and incomplete lineage sorting leading to long-standing uncertainty in species delimitation. These taxonomic criticalities are not to be overlooked as they go far beyond the disciplines of taxonomy and systematic botany. In fact, this type of knowledge is fundamental to many other seemingly unrelated disciplines, as reliable species identification is fundamental to ecological restoration, conservation planning, and biodiversity monitoring.
This PhD project focuses on the Festuca stricta-valesiaca complex, a particularly intricate group of fine-leaved fescues distributed across Eurasia, focusing on the taxa that naturally occurs in the Alps and Apennines. Taxa within this complex have been variously interpreted as species, subspecies, or hybrids, and their boundaries remain controversial. The aim of the study is to integrate morphological, cytogenetic, and molecular approaches to achieve a clearer understanding of taxa boundaries, evolutionary relationships, and nomenclatural stability within the group, for further application in ecological restoration projects.
To this end, 987 individuals from 66 populations were collected across the Alps and Apennines, supplemented by herbarium research and historical type material consultation in different European herbaria. Morphological variation was quantified using 32 characters from vegetative, reproductive, and anatomical traits, with analyses conducted through ordination and canonical discriminant methods. Flow cytometry was employed on fresh and recent herbarium material to assess ploidy levels and cytotype variation across populations. Finally, for a limited number of individuals, genomic data were generated using ddRAD sequencing, allowing phylogenetic inference of relationships within the complex and between taxa.
The analyses revealed clear differentiation between taxa with lower ploidy (F. valesiaca, F. sp. nova) and the more complex group of polyploid taxa (hexaploids, octoploids, decaploids), which showed in some cases morphological overlap but also evidence of reproductive isolation. Several diagnostic morphological characters, particularly leaf cross-section anatomy, scabridity, spikelets elements size and pubescence, were confirmed as useful for discrimination, though many boundaries remain blurred by gradual variation and shared traits. Flow cytometry confirmed known ploidy levels but also identified unexpected cytotypes in the Apennines, suggesting overlooked diversity or some polyploidization events. Phylogenomic analyses showed promising early results and laid a solid base for a more complete study of the group in the future
Interferometric Couplers for the Control of Quantum Light in Integrated Resonators
No full textWe leverage integrated ring resonators and interferometric couplers to design tunable and efficient quantum light sources. We critically review and develop theoretical models for on-chip squeezed light generation. Within this framework, we propose a Mach-Zehnder resonant interferometric coupler that selectively controls the quality factor of individual ring resonances, optimizing spontaneous four-wave mixing for the generation of high-purity heralded single photons and high-gain degenerate squeezed states. We select the waveguide material and geometry to balance the requirements of high nonlinearity, low losses, and opportune dispersion engineering. Finally, we introduce a Sagnac-interferometer-based resonant interferometric coupler to control spontaneous single-photon emission from a dipole, showcasing the versatility of resonant coupling architectures in quantum photonics.We leverage integrated ring resonators and interferometric couplers to design tunable and efficient quantum light sources. We critically review and develop theoretical models for on-chip squeezed light generation. Within this framework, we propose a Mach-Zehnder resonant interferometric coupler that selectively controls the quality factor of individual ring resonances, optimizing spontaneous four-wave mixing for the generation of high-purity heralded single photons and high-gain degenerate squeezed states. We select the waveguide material and geometry to balance the requirements of high nonlinearity, low losses, and opportune dispersion engineering. Finally, we introduce a Sagnac-interferometer-based resonant interferometric coupler to control spontaneous single-photon emission from a dipole, showcasing the versatility of resonant coupling architectures in quantum photonics
Invidia, politica e società nell’opera di Cicerone: osservazioni di lessico e di metodo
No full textIl periodo della tarda repubblica è quello in cui si manifestano le più accese rivalità che danno vita a forme esasperate di invidia sociale. La produzione ciceroniana appare significativamente attraversata dal tema dell’invidia
– seppure con sensibili differenze tra le opere trattatistiche e le orazioni – e lo
stesso Cicerone fu implicato storicamente nella discussione di delicati temi politici e
sociali
Qualche ulteriore considerazione su Leoni teorico della politica
No full textL'articolo si sofferma su alcuni aspetti della teoria politica di Bruno Leoni, e segnatamente sull'idea dello scambio di poteri interindividuale come criterio di identificazione della politicità