Large Deviations Theory of Increasing Returns

An influential theory of increasing returns has been proposed by the economist W. B. Arthur (1989) to explain the lock in phenomenon between two competing commercial products. In the most simplified situation there are two competing products that gain customers according to a majority mechanism: each new customer arrives and asks which product they bought to a certain odd number of previous customers, and then buy the most shared product within this sample. It is known that one of these two companies reaches monopoly almost surely in the limit of infinite customers. Here we consider a generalization proposed by G. Dosi et al. (1994), where the new customer follows the indication of the sample with some probability, and buy the other product otherwise. We provide a Large Deviation analysis of this model at the sample-path level, and describe a method to identify the most likely trajectories to reach some given market share. Interestingly, in the parameter range where the lock in phase is expected we observe a whole region of convergence where the entropy cost is sub-linear. We also find a non-linear differential equation for the the Cumulant Generating Function of the market share variable, that can be studied with a suitable perturbations theory.Comment: 30 pages, 9 figure

Mutual information for fermionic systems

We study the behavior of the mutual information (MI) in various quadratic fermionic chains, with and without pairing terms and both with short- and long-range hoppings. The models considered include the short-range Kitaev model and also cases in which the area law for the entanglement entropy is - logarithmically or non-logarithmically - violated. When the area law is violated at most logarithmically, the MI is a monotonically increasing function of the conformal four-point ratio x, also for the Kitaev model. Where non-logarithmic violations of the area law are present, then non-monotonic features of MI can be observed, with a structure of peaks related to the spatial configuration of Bell pairs, and the four-point ratio x is found to be not sufficient to capture the whole structure of the MI. For the model exhibiting perfect volume law, the MI vanishes identically. For the Kitaev model, when it is gapped or the range of the pairing is large enough, then the results have vanishing MI for small x. A discussion of the comparison with the results obtained by the AdS/CFT correspondence in the strong coupling limit is presented

Ma quanti sono gli ammalati di Covid-19 in Italia?

Mostriamo che la fase iniziale dell’epidemia in Cina ha avuto molto in comune con quella italiana, e che l’Italia ha avuto un ritardo di circa 40 giorni rispetto alla Cina Analizziamo il tempo che in media occorre ad una persona contagiata per sviluppare i primi sintomi e la data in cui i pazienti sono diventati sintomatici, e usiamo questa informazione per rendere il confronto fra il caso cinese e quello italiano più stringente. Difficoltà nella somministrazione dei tamponi in Italia hanno certamente portato a statistiche difficili da interpretare Facendo ragionevoli congetture emerge che il numero dei casi sintomatici in Italia potrebbe essere almeno quattro volte più grande di quello dichiarato (e forse anche di più) anche se siamo lontani da avere stime definitive La nostra analisi matematica suggerisce l’importanza di testare molto dei campioni statisticamente significativi di cittadini (misurandone anche gli anticorpi) e di rintracciare il maggior numero possibile di persone con cui i nuovi pazienti positivi sono state in contatto: misure di geo-localizzazione potrebbero essere cruciali Controlliamo infine che, a parte piccole discrepanze spiegabili in vari modi, i dati epidemiologici che la Cina ha fornito sembrano essere affidabil

"Paradoxical" p16 overexpression in cutaneous melanoma: Molecular and immunohistochemical analysis of a rare phenomenon with a focus on cell cycle regulatory molecules

Background: One of the most relevant genetic alterations in cutaneous melanoma (CM) is the biallelic inactivation/loss-of-heterozygosis (LOH) of cyclin-dependent kinase inhibitor 2 A (CDKN2A), which results in the immunohistochemical loss of p16 frequently found in CM. However, we recently described a rare case of dermal/deep-seated melanoma arising in giant congenital nevus (DDM-GCN) with p16 overexpression combined with p53 loss and tumor protein 53 (TP53) mutation. Herein, we reported a case series of CM with p16 overexpression and analyzed their clinicopathologic features, immunohistochemical expression of the cell cycle regulatory molecules (CCRM: p53, p21, Cyclin D1, Rb), and mutational landscape. Methods: We retrospectively tested for p16 all cases of CM diagnosed at our institution between January 1st 2019-April 1st 2022. In CM with p16 overexpression, we reported clinicopathologic features, immunohistochemical results for melanocytic markers and CCRM, and mutational landscape investigated with a next-generation sequencing (NGS) panel. In cases with zonal p16 overexpression, the immunohistochemical assessment for melanocytic markers and CCRM, as well as the NGS analysis have been performed in both components {with and without p16 overexpression [p16(+)c and p16(-)]}. Results: Overexpression of p16 was found in 10/2879 (0.35%) CM [5/10 (50%) diffuse and 5/10 (50%) zonal]. We combined the immunohistochemical results for CCRM and molecular data to classify the cases as follows: a) Group 1 with altered expression of at least one CCRM but no TP53 mutations [3/10 (30%), all with Rb altered/lost]; b) Group 2 with altered expression of at least one CCRM and TP53 mutations [4/10 (40%), all with p53 altered]; c) Group 3 with normal expression of CCRM and no TP53 mutations [3/10 (30%), all with mutations in MAPK pathway genes (NRAS and BRAF)]. In CM with zonal p16 overexpression, the histologic appearance of p16(+)c was heterogeneous, whereas combining CCRM profiles and molecular data the cases could be categorized as follows: a) cases with the same CCRM and molecular profiles in both p16(+)c and p16(-)c; b) cases with p16(+)c showing additional genetic mutations and/or modifications of CCRM expression. Conclusions: p16 overexpression is a rare event, occurring in advanced-stage, clinically- and histologically-heterogeneous CM. These lesions may be classified into three different groups based on CCRM expression and mutational profiles (including TP53 mutation). The analysis of CM with zonal p16 overexpression suggests that, at least in a subset of cases, this phenomenon could represent a sign of "molecular progression" due to the acquisition of additional genetic mutations and/or modifications of the CCRM profile

Trabalho de Campo em Saúde Bucal: Um Contexto da Relação Ensino-Serviço-Comunidade

Trata-se de um relato de experiência sobre a introdução de conteúdos e estratégias pedagógicas na disciplina de Saúde Coletiva em Odontologia da Faculdade de Odontologia da Universidade de São Paulo (FOUSP) que, seguindo as orientações das Diretrizes Curriculares Nacionais para cursos de Odontologia, utiliza o Sistema Único de Saúde (SUS) como cenário pedagógico, permitindo ao aluno vivenciar e dialogar com a realidade in loco, ampliando o olhar e a escuta. Por meio de módulos de conteúdo aplicados com uma pedagogia baseada em problemas, a construção da teoria é complementada com visitas técnicas ao SUS do município de Embu das Artes, além da elaboração, ao longo do ano e em grupo, de uma política municipal de saúde bucal de outro município do estado de São Paulo. A experiência propõe fornecer ao aluno instrumentos de análise críticoreflexiva, inserindo sua prática num contexto social que visa a atender as necessidades em saúde da população.This is an experience report on the introduction of content and teaching strategies in the discipline of Community Dental Health of the Faculty of Dentistry in São Paulo State University (FOUSP) that, following the suggestions of the National Curriculum Guidelines for Dentistry courses, use the Unified Public Health System (SUS) as a pedagogical scenario, allowing students to experience and dialogue with the reality on the spot, extending their observation skills. Through content modules with a problematical pedagogy, theory building is complemented with technical visits to the SUS of Embu das Artes in addition to the development, throughout the year and collectively, of a municipal policy of oral health public system of another municipality of the State of São Paulo. The experience intends to provide students with tools for critical and reflective analysis, inserting their practice in a social context that aims to meet the health needs of the population

Stroke management during the coronavirus disease 2019 (COVID-19) pandemic: experience from three regions of the north east of Italy (Veneto, Friuli-Venezia-Giulia, Trentino-Alto-Adige)

Background: Efficiency of care chain response and hospital reactivity were and are challenged for stroke acute care management during the pandemic period of coronavirus disease 2019 (COVID-19) in North-Eastern Italy (Veneto, Friuli-Venezia-Giulia, Trentino-Alto-Adige), counting 7,193,880 inhabitants (ISTAT), with consequences in acute treatment for patients with ischemic stroke. Methods: We conducted a retrospective data collection of patients admitted to stroke units eventually treated with thrombolysis and thrombectomy, ranging from January to May 2020 from the beginning to the end of the main first pandemic period of COVID-19 in Italy. The primary endpoint was the number of patients arriving to these stroke units, and secondary endpoints were the number of thrombolysis and/or thrombectomy. Chi-square analysis was used on all patients; furthermore, patients were divided into two cohorts (pre-lockdown and lockdown periods) and the Kruskal-Wallis test was used to test differences on admission and reperfusive therapies. Results: In total, 2536 patients were included in 22 centers. There was a significant decrease of admissions in April compared to January. Furthermore, we observed a significant decrease of thrombectomy during the lockdown period, while thrombolysis rate was unaffected in the same interval across all centers. Conclusions: Our study confirmed a decrease in admission rate of stroke patients in a large area of northern Italy during the lockdown period, especially during the first dramatic phase. Overall, there was no decrease in thrombolysis rate, confirming an effect of emergency care system for stroke patients. Instead, the significant decrease in thrombectomy rate during lockdown addresses some considerations of local and regional stroke networks during COVID-19 pandemic evolution

Genome-wide diversity, population structure and signatures of inbreeding in the African buffalo in Mozambique

DATA AVAILABILITY : All sequence data presented here (fastq format) have been deposited into the NCBI SRA database (accession number: PRJNA971211).The African buffalo, Syncerus caffer, is a key species in African ecosystems. Like other large herbivores, it plays a fundamental role in its habitat acting as an ecosystem engineer. Over the last few centuries, African buffalo populations have declined because of range contraction and demographic decline caused by direct or indirect human activities. In Mozambique, historically home to large buffalo herds, the combined effect of colonialism and subsequent civil wars has created a critical situation that urgently needs to be addressed. In this study, we focused on the analysis of genetic diversity of Syncerus caffer caffer populations from six areas of Mozambique. Using genome-wide SNPs obtained from ddRAD sequencing, we examined the population structure across the country, estimated gene flow between areas under conservation management, including national reserves, and assessed the inbreeding coefficients. Our results indicate that all studied populations of Syncerus caffer caffer are genetically depauperate, with a high level of inbreeding. Moreover, buffaloes in Mozambique present a significant population differentiation between southern and central areas. We found an unexpected genotype in the Gorongosa National Park, where buffaloes experienced a dramatic population size reduction, that shares a common ancestry with southern populations of Catuane and Namaacha. This could suggest the past occurrence of a connection between southern and central Mozambique and that the observed population structuring could reflect recent events of anthropogenic origin. All the populations analysed showed high levels of homozygosity, likely due to extensive inbreeding over the last few decades, which could have increased the frequency of recessive deleterious alleles. Improving the resilience of Syncerus caffer caffer in Mozambique is essential for preserving the ecosystem integrity. The most viable approach appears to be facilitating translocations and re-establishing connectivity between isolated herds. However, our results also highlight the importance of assessing intraspecific genetic diversity when considering interventions aimed at enhancing population viability such as selecting suitable source populations.This research was supported by the projects “Training in Biodiversity and Biotechnology for sustainable development” (AID 11096) and BioForMoz “Support for Environmental Research” (AID 12089) managed by the Department of Biomedical Sciences, University of Sassari, Italy, and funded by the Italian Agency for Development Cooperation, Italy. Open Access funding enabled and organized by Projekt DEAL.https://bmcecolevol.biomedcentral.comhj2024Veterinary Tropical DiseasesSDG-15:Life on lan

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV