3,603 research outputs found
Geometric k-normality of curves and applications
The notion of geometric k-normality for curves is introduced in complete
generality and is investigated in the case of nodal and cuspidal curves living
on several types of surfaces. We discuss and suggest some applications of this
notion to the study of Severi varieties of nodal curves on surfaces of general
type and on the plane.Comment: 15 page
Resting-state connectivity and functional specialization in human medial parieto-occipital cortex
According to recent models of visuo-spatial processing, the medial parieto-occipital cortex is a crucial node of the dorsal visual stream. Evidence from neurophysiological studies in monkeys has indicated that the parieto-occipital sulcus (POS) contains three functionally and cytoarchitectonically distinct areas: the visual area V6 in the fundus of the POS, and the visuo-motor areas V6Av and V6Ad in a progressively dorsal and anterior location with respect to V6. Besides different topographical organization, cytoarchitectonics, and functional properties, these three monkey areas can also be distinguished based on their patterns of cortico-cortical connections. Thanks to wide-field retinotopic mapping, areas V6 and V6Av have been also mapped in the human brain. Here, using a combined approach of resting-state functional connectivity and task-evoked activity by fMRI, we identified a new region in the anterior POS showing a pattern of functional properties and cortical connections that suggests a homology with the monkey area V6Ad. In addition, we observed distinct patterns of cortical connections associated with the human V6 and V6Av which are remarkably consistent with those showed by the anatomical tracing studies in the corresponding monkey areas. Consistent with recent models on visuo-spatial processing, our findings demonstrate a gradient of functional specialization and cortical connections within the human POS, with more posterior regions primarily dedicated to the analysis of visual attributes useful for spatial navigation and more anterior regions primarily dedicated to analyses of spatial information relevant for goal-directed action
The Atlantic bluefin tuna: structure and competitiveness of Italian fishing in the international trade
In this paper after showing the productive and international trade background of the Atlantic bluefin tuna, we analyze the competitive position of Italy, important producer and exporter on world scale, compared with the main trade partners, carried out through competitiveness indexes based on trade data. The results highlight Italy's good competitive performance above all with Japan, which represents the main world reference market for the Italian product, but also with the United States, Malta and Turkey The Italian competitive advantage with these countries is stronger for the product taken into account. On the other hand, we can notice a competitive disadvantage with the traditional markets supplying bluefin tuna, and with Spain in particular The same is reckoned with the Southern Mediterranean countries which, in the last years, have contributed to increasing the world supply thanks to the spread of mariculture systems. In this background, the increasing interest in the Italian Atlantic bluefin tuna, by the United States in particular and by some Mediterranean countries and by Central Western Europe as well, could open new opportunities to the Italian trade
Prognostic significance of primary-tumor extension, stage and grade of nuclear differentiation in patients with renal cell carcinoma
Surgery remains the preferred therapy for renal cell carcinoma. The various adjunctive or complementary therapies currently yield disappointing results. Identifying reliable prognostic factors could help in selecting patients most likely to benefit from postoperative adjuvant therapies. We reviewed the surgical records of 78 patients who had undergone radical nephrectomy with lymphadenectomy for renal cell carcinoma, matched for type of operation and histology. According to staging (TNM), 5.1% of the patients were classified as stage I, 51.3% as stage II, 29.5% as stage III and 14.5% as stage IV. Of the 78 patients 40 were T2N0 and 21 T3aN0. Tumor grading showed that 39.7% of the patients had well-differentiated tumors(G1), 41.1% moderately-differentiated (G2), and 19.2% poorly-differentiated tumors (G3). Overall actuarial survival at 5 and 10 years was 100% for stage 1; 91.3% at 5 years and 83.1% at 10 years for stage II; 45.5% and 34.1% for stage III; and 29.1% and nil for stage IV (stage II vs stage III p = 0.0001). Patients with tumors confined to the kidney (pT2N0) had better 5- and 10-year survival rates than patients with tumors infiltrating the perirenal fat (pT3aN0) (p = 0.000006). Survival differed according to nuclear grading (G1 vs G3 ; p = 0.000005; G2 vs G3; p = 0.0009). In conclusion our review identified tumor stage, primary-tumor extension, and the grade of nuclear differentiation as reliable prognostic factors in patients with renal cell carcinomas
The Impact of Education and Culture on Poverty Reduction: Evidence from Panel Data of European Countries
The 2030 Agenda has among its key objectives the poverty eradication through increasing the level of education. A good level of education and investment in culture of a country is in fact necessary to guarantee a sustainable economy, in which coexists satisfactory levels of quality of life and an equitable distribution of income. There is a lack of studies in particular on the relations between some significant dimensions, such as education, culture and poverty, considering time lags for the measurement of impacts. Therefore, this study aims to fill this gap by focusing on the relationship between education, culture and poverty based on a panel of data from 34 European countries, over a 5-year period, 2015–2019. For this purpose, after applying principal component analysis to avoid multicollinearity problems, the authors applied three different approaches: pooled-ordinary least squares model, fixed effect model and random effect model. Fixed-effects estimator was selected as the optimal and most appropriate model. The results highlight that increasing education and culture levels in these countries reduce poverty. This opens space to new research paths and policy strategies that can start from this connection to implement concrete actions aimed at widening and improving educational and cultural offer
Sicilian floriculture companies and the role of transport in increasing their competitiveness
The aim of this study is to provide a deeper understanding of the Sicilian floriculture sector, which has recently become one of the most important on a regional and national scale. By analysing production, sales and logistical aspects of its production companies and specifically looking at aspects regarding transport logistics, this study highlights the sector operators. preference for road transport that offers better guarantees in terms of delivery speed with respect to other means of transport, an essential requirement for the transport of flowers and plants. However, operators are increasingly showing interest in alternative means of transport that may reduce transport time and, especially, costs. Some of the operators interviewed believe that the expected building of 7 trucking terminals in Sicily represents an important move of the Regional Government to support companies; nevertheless, others think that this type of intervention represents an erosive element in competitiveness, because of the probable increase in the presence of goods coming from the southern Mediterranean shore. However, the improvement of the regional transport system is necessary to reduce inefficiencies in the sales and distribution network of the floriculture industry and, more in general, of the whole Sicilian agri-food industry
How the COVID-19 pandemic is changing online food shopping human behaviour in Italy
The advent of the Internet has significantly changed consumption patterns and habits. Online grocery shopping is a way of purchasing food products using a web-based shopping service. The current COVID-19 pandemic is determining a rethinking of purchase choice elements and of consumers\u2019 behavior. This work aims to investigate which characteristics can affect the decision of online food shopping during the pandemic emergency in Italy. In particular, the work aims to analyze the effects of a set of explanatory variables on the level of satisfaction for the food online shopping experience. For achieving this aim, the proportional odds version of the cumulative logit model is carried out. Data derive from an anonymous on-line questionnaire administrated during the first months of the pandemic and filled by 248 respondents. The results of this work highlight that people having familiarity with buying food online, that have a higher educational level and consider food online channels easy to use, appear more satisfied for the food online shopping experience. These findings can be crucial for the future green global challenges as online shopping may help to reach competitive advantages for company sustainability
The role of internal resources in the competitive positioning of Sicilian wine cooperatives
The paper is an original article that uses accounting frameworks to determine what creates a competitive advantage in a cooperative business model. In particular, it investigates the influence of tangible, intangible and financial resources on the business performance of cooperatives operating in the Sicilian wine industry, with the RBV of the firms as a theoretical background. Using a linear regression model, our results show that tangible and financial resources are a source of a sustained competitive advantage. This study fills the gap existing in the strategic management literature related to the role of resources, tangible and intangible, in the cooperative system, providing both theoretical and practical implications
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