Exciton-exciton interaction engineering in coupled GaN quantum dots

We present a fully three-dimensional study of the multiexciton optical response of vertically coupled GaN-based quantum dots via a direct-diagonalization approach. The proposed analysis is crucial in understanding the fundamental properties of few-particle/exciton interactions and, more important, may play an essential role in the design/optimization of semiconductor-based quantum information processing schemes. In particular, we focus on the interdot exciton-exciton coupling, key ingredient in recently proposed all-optical quantum processors. Our analysis demonstrates that there is a large window of realistic parameters for which both biexcitonic shift and oscillator strength are compatible with such implementation schemes.Comment: 3 two-column pages, 3 figure

La documentazione epigrafica delle città-stato del Jawf fra il IX e il VI secolo a.C.

L’obiettivo della presente ricerca è la definizione del contesto storico e culturale della più antica fase (il cosiddetto periodo “madhābieno”) della civiltà sudarabica nella valle del Jawf (Yemen settentrionale) attraverso l’analisi della sua documentazione epigrafica monumentale. Nella prima metà del I millennio a.C., questa regione si caratterizza per la fioritura di cinque piccole città-stato (Nashshān, Ma‘īn, Haram, Kamna and Inabba’), un’organizzazione politica particolare rispetto ai regni maggiori che in quest’epoca stanno definendo le loro sfere di influenza nell’Arabia del Sud. Attraverso lo studio di 264 iscrizioni che sono state identificate nel corso del presente lavoro come la documentazione dei cinque regni, è stato possibile ricostruire la storia di questi, stabilendo i limiti cronologici del “periodo antico”, almeno dalla fine del IX fino all’inizio del VI secolo a.C., quando l’espansione del regno di Ma‘īn creò un nuovo assetto geopolitico della regione. L’edizione completa di questo corpus di testi – dei quali sono fornite le informazioni rilevanti, la trascrizione, la traduzione e un commento – ha permesso di tracciare un quadro della cultura “madhābiena”, nelle sue caratteristiche religiose, sociali e di documentazione testuale. The aim of this research is to define the history and the culture of the most ancient phase (the so-called “madhābaean” period) of the Ancient South Arabian civilization in the Jawf valley (northern Yemen) through the analysis of its monumental epigraphic documentation. In the first half of the I millennium BC, this region is characterized by the flourishing of five small city-states (Nashshān, Ma‘īn, Haram, Kamna and Inabba’), a peculiar political organization in respect to the major kingdoms that were defining their sphere influence on Southern Arabia at that time. Through the study of the 264 inscription which have been identified as the documentation of the five city-states, it has been possible to reconstruct their history, defining the chronological limits of this “ancient period” from at least the end of the 9th to the beginning of the 6th century BC, when the kingdom of Ma‘īn succeeded in establishing a new geo-political asset of the region. The complete edition of this corpus of texts – with relevant information, transcription, translation and commentary provided – has allowed to draw a picture of the “madhābaean” culture, in its religious, social and textual-linguistic features

Mathematical Reconstruction of Eroded Beach Ridges at the Ombrone River Delta

Several remotely sensed images, acquired by different sensors on satellite, airplane, and drone, were used to trace the beach ridges pattern present on the delta of the River Ombrone. A more detailed map of these morphologies, than those present in the literature, was obtained, especially at the delta apex, where beach ridges elevation in minor. Beach ridges crests, highlighted through image enhancement using ENVI 4.5 and a DTM based on LiDAR data, were then processed with ArcGIS 9.3 software. Starting from this map, a method to reconstruct beach ridges segments deleted by the transformations of the territory is proposed in this paper. The best crest-lines fitting functions were calculated through interpolation of their points with Curve Expert software, and further extrapolated to reconstruct the ridges morphology where human activity, riverbed migration, or coastal erosion eliminated them. This allowed to reconstruct the ridges pattern also offshore the present delta apex, where the shoreline retreated approximately 900 m in the last 150 years. Results can be further used to implement conceptual and numerical models of delta evolution

Solving the two membranes problem for different operators by iterations of the obstacle problem

In this paper we analyze iterations of the obstacle problem for two different operators. We solve iteratively the obstacle problem from above or below for two different differential operators with obstacles given by the previous functions in the iterative process. When we start the iterations with a super or a subsolution of one of the operators this procedure generates two monotone sequences of functions that we show that converge to a solution to the two membranes problem for the two different operators. We perform our analysis in both the variational and the viscosity settings

Synchronous primary papillary breast cancer, medullary thyroid carcinoma and neuroendocrine tumor in postmenopausal woman.

Multiple endocrine neoplasia are syndromes involving two or more endocrine tissues, often correlated to RET proto-oncogene mutations. We herein present the first reported case of a 57-years-old woman with three synchronous primary cancers of breast (papillary), thyroid (medullary) and pancreas (neuroendocrine), the latter with liver metastasis. The patient first underwent surgery for papillary breast cancer with axillary lymph nodes metastases. A staging whole body computerized tomography (CT) showed a right lateral cervical lymph node, pancreatic inhomogeneity, peri-pancreatic nodes and a single liver metastasis. The poor response to an antracycline and taxane-based chemotherapy, the good performance status of patient, and associated symptoms, suggested a different origin for pancreatic and hepatic lesions. A careful re-evaluation of clinical history, an octreotide-labeled scan and an immunohistochemical analysis, on both hepatic and pancreatic tissues and on laterocervical lymph node, determined the diagnosis of synchronous papillary breast cancer, pancreatic neuroendocrine tumor (pNET) with liver metastasis and an occult medullary thyroid carcinoma in a patient who had proto-oncogene RET wild type

Effects of the Representation of Convection on the Modelling of Hurricane Tomas (2010)

The cumulus parameterization is widely recognised as a crucial factor in tropical meteorology: this paper intends to shed further light on the effects of convection parameterization on tropical cyclones’ numerical predictions in the “grey zone” (10–1 km grid spacing). Ten experiments are devised by combining five different convection treatments over the innermost, 5 km grid spacing, domain, and two different global circulation model datasets (IFS and ERA-Interim). All ten experiments are finally analysed and compared to observations provided by the National Hurricane Center’s best track record and multisatellite rainfall measurements. Results manifestly point to the superiority of employing no convective parameterization at the scale of 5 km versus the usage of any of those provided by WRF to reproduce the case study of Hurricane Tomas, which hit the Lesser Antilles and Greater Antilles in late October and early November 2010

Extending 3-DoF Metrics to Model User Behaviour Similarity in 6-DoF Immersive Applications

Immersive reality technologies, such as Virtual and Augmented Reality, have ushered a new era of user-centric systems, in which every aspect of the coding--delivery--rendering chain is tailored to the interaction of the users. Understanding the actual interactivity and behaviour of the users is still an open challenge and a key step to enabling such a user-centric system. Our main goal is to extend the applicability of existing behavioural methodologies for studying user navigation in the case of 6 Degree-of-Freedom (DoF). Specifically, we first compare the navigation in 6-DoF with its 3-DoF counterpart highlighting the main differences and novelties. Then, we define new metrics aimed at better modelling behavioural similarities between users in a 6-DoF system. We validate and test our solutions on real navigation paths of users interacting with dynamic volumetric media in 6-DoF Virtual Reality conditions. Our results show that metrics that consider both user position and viewing direction better perform in detecting user similarity while navigating in a 6-DoF system. Having easy-to-use but robust metrics that underpin multiple tools and answer the question ``how do we detect if two users look at the same content?" open the gate to new solutions for a user-centric system

Extending 3-DoF Metrics to Model User Behaviour Similarity in 6-DoF Immersive Applications

Immersive reality technologies, such as Virtual and Augmented Reality, have ushered a new era of user-centric systems, in which every aspect of the coding-delivery-rendering chain is tailored to the interaction of the users. Understanding the actual interactivity and behaviour of the users is still an open challenge and a key step to enabling such a user-centric system. Our main goal is to extend the applicability of existing behavioural methodologies for studying user navigation in the case of 6 Degree-of-Freedom (DoF). Specifically, we first compare the navigation in 6-DoF with its 3-DoF counterpart highlighting the main differences and novelties. Then, we define new metrics aimed at better modelling behavioural similarities between users in a 6-DoF system. We validate and test our solutions on real navigation paths of users interacting with dynamic volumetric media in 6-DoF Virtual Reality conditions. Our results show that metrics that consider both user position and viewing direction better perform in detecting user similarity while navigating in a 6-DoF system. Having easy-to-use but robust metrics that underpin multiple tools and answer the question "how do we detect if two users look at the same content?" open the gate to new solutions for a user-centric syste