2,096 research outputs found
A study of the genus Thaumetopoea (Lepidoptera: Notodontidae), using morphological, ecological, andmolecular traits
Thaumetopoeinae include several species called processionary moths, mainly due to their gregarious behaviour to form long single lines to forage and to pupate. Even if historically it has been considered as a separate family, Thaumetopoeinae were recently included as a subfamily of Notodontidae, based on both cladistic and molecular analyses. This groups has a great importance for forestry and landscape because their larvae feed on trees and shrubs, both broadleaved and coniferous, defoliating the canopy and weakening the plants, making them more susceptible to tree killers (i.e. bark beetles). Furthermore, they threaten human and animal health due to the presence of urticating setae in larvae and/or adults that are used as an effective defence strategy against vertebrate predators. In humans, these setae are responsible of allergic reactions, also of strong intensity, from dermatitis to anaphylactic shock; instead in animals, they produce pruritus, necrosis, abortions, anorexia, up to death. Thaumetopoea is the most known genus and historically it has been split into three separated genera. A recent molecular study has defined the phylogenetic relationships and the evolution of life history traits for a few taxa of this genus that is mainly distributed in Europe, the Mediterranean and Iranoturanic areas.
In the first study, I completed the phylogeny of the genus analysing all the 15 species of Thaumetopoea s. lat., introducing both rare species found in different museum collections, by defining a set of 165 traits from head, thorax, abdomen, wing and male genitalia. The very recently described Thaumetopoea loxostigma Hacker, 2016 could not be included as the only extant specimen, viz. the holotype, was not available. According to the original description, T. loxostigma is closely related to the Thaumetopoea apologetica – Thaumetopoea jordana group, which itself needs revision. Five subspecies other than nominal ones are currently recognised within Thaumetopoea , namely T. apologetica abyssinica, T. herculeana judaea, T. processionea pseudosolitaria, T. solitaria iranica, and T. pityocampa orana, and they were included in the analysis. Whenever possible, the specimens were compared with the types of the various species. Morphological traits were combined with 9 mitochondrial genes already present in literature for some species. For the others, I sequenced the barcoding portion of cox1 due to the difficulties to amplify old fragmented DNA also using ad hoc primers. Matrix was processed using different software, to test different approaches, and the analyses were conducted both on separated matrix (morphological vs. molecular) and in combined ones (morphological + molecular). Finally, morphological traits were plotted on reference tree in order to identify apomorphies and homoplasious changes useful to draw a morphological key for the Thaumetopoea genus. Furthermore, I selected ecological and life history traits: presence of urticating setae on larva; pupation site; larval seasonal feeding activity; host plant group; host plant family, in order to outline the traits of a possible ancestor of processionary moths.
In the second study, I use the morphological traits collected and the large number of specimens analysed to draw a morphological key and distribution maps of the whole genus Thaumetopoea, which will be helpful to entomologists and foresters to identify the adult specimens both in museum collection and in field. In the meantime, I synonymised some taxa recently described, mainly for lack of diagnostic characters or inconsistency.
In the third study, I focused on the single clade genus Thaumetopoea in order to collect the information about the species of the 'summer' Thaumetopoea from Eurasia, feeding on coniferous hosts. Information included morphological and life history traits. Furthermore, the work involved also T. cheela that is proposed to be included in this group based on morphology and indirect evidence of life history traits. Although some evidences supported the hypothesis that Cedrus could be the host on which most of speciation in the summer clade had happened, more studies have to be made, especially for the less known species.
Although my works complete the phylogeny of the genus of Thaumetopoea and provide valid methods to identify the species, which is very important because of the group includes some of the most important forest pests that also affect human and domesticated animal health through the urticating setae, more work is left to do in order to complete the knowledge on some neglected taxa and to expand the analysis to other genera of the subfamily, which apparently share the same traits and are causing similar problems in other continents
Discovery potential for in the trilepton channel at the LHC
The LHC discovery potential of heavy top partners decaying into a top quark
and a boson is studied in the trilepton channel at TeV. The
clean multilepton final state allows to strongly reduce the background
contaminations and to reconstruct the mass. We show that a simple
cut-and-count analysis probes the parameter space of a simplified model as
efficiently as a dedicated multivariate analysis. The trilepton signature
finally turns out to be as sensitive in the low mass region as the
complementary channel with a fully hadronic top quark, and more sensitive in
the large mass domain. The reinterpretation in terms of the top--up
anomalous coupling is shown.Comment: 18 pages, 9 figures, 6 tables. Matching published versio
Diabetes Mellitus and Reprogrammed Glucose Metabolism in Pancreatic Cancer: Features for Clinical Translation
The reprogrammed metabolism of cancer cells underlies the shift of glucose energetics from the highly efficient oxidative phosphorylation to the less efficient aerobic glycolysis, the Warburg effect. This phenomenon, with the activation of the glutamine pathway, advantage survival and proliferation of pancreatic ductal adenocarcinoma (PDAC) cells, which live in an adverse hypoxic and nutrient restricted microenvironment. In PDAC, glucose metabolic alterations occur also at the whole organism, diabetes mellitus (DM) being diagnosed in approximately 60% to 80% of patients. The association beteen PDAC and DM is a dual face phenomenon, DM being both a risk factor for and a consequence of this tumor type. Data from epidemiology indicate that longstanding DM increases PDAC risk 1.5 to 2.0 fold, probably because of the pro-proliferative effects of hyperinsulinemia. By contrast early onset DM, i.e. diabetes diagnosed no more than two years prior to cancer diagnosis, is considered a consequence of PDAC. Secondary DM is due to complex interactions between tumor cells, tumor microenvironment and pancreatic endocrine cells. In this scenario the role of the inflammatory S100A8 calcium binding protein, matrix metalloproteinases, Vanin1 or amylin has been experimentally demonstrated. However, the efforts made to translate in the clinical practice any individual new poteantial biomarker failed, because none reached enough sensitivity and specificity to be considered a reliable biomarker to diagnose PDAC even in high risk subjects as those with new onset DM. Therefore the identification and clinical validation of new biomarkers remains a challenge for future studies
Facets of Right Measure: Cognitive Images and Leadership of Minds in Plato's 'Statesman'
This thesis illuminates two underexplored facets of Plato’s notion of right measure in the Statesman: the cognitive role of imagery and the correct leadership of minds for individuals and political communities.
The central chapters of this thesis argue that the cognitive function of images is grounded on their well-articulated combination. The first and last chapters serve to frame this study of imagery within the main subject of the dialogue, namely the correct guidance of human minds. This study is thus divided in five chapters that explore the different facets of right measure in different contexts.
The first chapter examines the structure of the Statesman as representing a disrupted dialectical process aimed at discovering the right measure of philosophical judgments. The second chapter studies the notions of paradeigmata and eikones as images to be artfully combined in a cohesive, measured whole. The third chapter accounts for the value of mythical paidia as productive of a clash of images that corrects excesses and invites to seek for measured judgments. The fourth chapter examines Plato’s usage of contrasting images of divine steering and cosmic balance to represent an expert communication of inner harmony. Finally, the last chapter returns to the Statesman as a whole, examining how Plato represents education and educational leadership as communication of a well-composed balance to the mind and to the political community.
This project illuminates a frequently overlooked of Plato’s philosophy: its nuanced and flexible attention to the guidance of human minds in need of psychological and political equilibrium
A Post-Quantum Round-Optimal Oblivious PRF from Isogenies
An oblivious pseudorandom function, or OPRF, is an important primitive that is used to build many advanced cryptographic protocols. Despite its relevance, very few post-quantum solutions exist.
In this work, we propose a novel OPRF protocol that is post-quantum, verifiable, round-optimal, and moderately compact. Our protocol is based on a previous SIDH-based construction by Boneh, Kogan, and Woo, which was later shown to be insecure due to an attack on its one-more unpredictability.
We first propose an efficient countermeasure against this attack by redefining the PRF function to use irrational isogenies. This prevents a malicious user from independently evaluating the PRF.
The SIDH-based construction by Boneh, Kogan, and Woo is also vulnerable to the recent attacks on SIDH. We thus demonstrate how to efficiently incorporate the countermeasures against such attacks to obtain a secure OPRF protocol. To achieve this, we also propose the first proof of isogeny knowledge that is compatible with masked torsion points, which may be of independent interest.
Lastly, we design a novel non-interactive proof of knowledge of parallel isogenies, which reduces the number of communication rounds of the OPRF to the theoretically-optimal two.
Putting everything together, we obtain the most compact post-quantum verifiable OPRF protocol
POKE: A Framework for Efficient PKEs, Split KEMs, and OPRFs from Higher-dimensional Isogenies
We introduce a new framework, POKE, to build cryptographic protocols from irrational isogenies using higher-dimensional representations. The framework enables two parties to manipulate higher-dimensional representations of isogenies to efficiently compute their pushforwards, and ultimately to obtain a shared secret.
We provide three constructions based on POKE: the first is a PKE protocol, which is one of the most compact post-quantum PKEs and possibly the most efficient isogeny-based PKE to date. We then introduce a validation technique to ensure the correctness of uniSIDH public keys: by combining the validation method with a POKE-based construction, we obtain a split KEM, a primitive that generalizes NIKEs and can be used to instantiate a post-quantum version of the Signal\u27s X3DH protocol. The third construction builds upon the split KEM and its validation method to obtain a round-optimal verifiable OPRF. It is the first such construction that does not require more than isogeny computations, and it is significantly more compact and more efficient than all other isogeny-based OPRFs
RECONSTRUCTION OF A LOST CARBONATE FACTORY BASED ON ITS BIOGENIC DETRITUS (TERNATE-TRAVEDONA FORMATION AND GONFOLITE LOMBARDA GROUP - NORTHERN ITALY)
This work reconstructs a now completely eroded late Eocene to earliest Oligocene carbonate factory of Northern Italy, through the analysis of a carbonate deep-water-fan sequence (Ternate-Travedona Formation) and the limestone detritus dispersed into the late Oligocene clastic-wedge of the Gonfolite Lombarda Group. Textural characteristics and skeletal assemblages of the Gonfolite pebbles were studied and compared to those of the Ternate-Travedona Formation. The same skeletal assemblage and the same taxa were found in samples from both areas, suggesting their common origin. Whereas the Ternate-Travedona Formation skeletal grains were reworked during transport, the Gonfolite Lombarda Group pure-limestone pebbles are pristine fragments of the carbonate platform, that was uplifted and eroded from the late Eocene to the early Oligocene. Using both these sources of information it was possible to reconstruct the late Eocene environment and its facies distribution. The areas undergoing high hydrodynamic energy were dominated by free-living coralline-algal branches, rhodoliths and larger thick-tested benthic foraminifera. A coralline framework, associated with thin-tested benthic foraminifera and boxwork rhodoliths, was present in slightly deeper and sheltered environments. Episodic debris flows, mainly triggered by river floods, supplied the sub-marine fan of the Ternate-Travedona Formation. These events were able to down-cut through the narrow platform and rip off large fragments of the substrate. River runoff probably also supplied large quantities of organic matter, leading to local oxygen-depletion and preservation of organic matter. The combined stressful effects of bottom instability and riverine discharge probably excluded corals from the association. The integrated study of the Ternate-Travedona Formation, and of the limestone pebbles in the Gonfolite Group, have enabled the reconstruction of this otherwise lost Eocene carbonate factory
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