Search results for "Rima"
showing 10 items of 3334 documents
Varieties of algebras with pseudoinvolution and polynomial growth
2017
Let A be an associative algebra with pseudoinvolution (Formula presented.) over an algebraically closed field of characteristic zero and let (Formula presented.) be its sequence of (Formula presented.) -codimensions. We shall prove that such a sequence is polynomially bounded if and only if the variety generated by A does not contain five explicitly described algebras with pseudoinvolution. As a consequence, we shall classify the varieties of algebras with pseudoinvolution of almost polynomial growth, i.e. varieties of exponential growth such that any proper subvariety has polynomial growth and, along the way, we shall give also the classification of their subvarieties. Finally, we shall de…
12 gennaio 1848: a Palermo inizia la Primavera dei popoli
2016
Quanto accade a Palermo il 12 gennaio 1848 resterà per sempre tra gli annali del tempo come un evento che apre una nuova stagione europea passata alla storia con la definizione di “Primavera dei popoli”. Al di là dell’esito che nell’immediato se ne ha in Sicilia, quelle che da quest’isola si riverberano ben presto in tutta Europa sono insurrezioni destinate a mutare società e nazioni del Vecchio continente.
Éducation primaire et croissance économique en Afrique subsaharienne : les conditions d'une relation efficace
1995
This article is looking at the causes of the low effectiveness of educational investment in Subsaharan Africa, both at the micro level (effect on labour productivity), and at the macro level (effect on the rate of economic growth). Several recent empirical studies have shown that education impact is systematically weaker in this region than in the rest of the world, and even sometimes negative, as in the case of agricultural productivity. Two series of causes may explain this lack of impact : first, inappropriate economic policies at the macro level which hamper the role of education, either through negative incentives structures, or because of the absence of provision of associated factors…
Land use intensification increasingly drives the spatiotemporal patterns of the global human appropriation of net primary production in the last cent…
2021
Land use has greatly transformed Earth's surface. While spatial reconstructions of how the extent of land cover and land-use types have changed during the last century are available, much less information exists about changes in land-use intensity. In particular, global reconstructions that consistently cover land-use intensity across land-use types and ecosystems are missing. We, therefore, lack understanding of how changes in land-use intensity interfere with the natural processes in land systems. To address this research gap, we map land-cover and land-use intensity changes between 1910 and 2010 for 9 points in time. We rely on the indicator framework of human appropriation of net primar…
Some Applications of the Poincaré-Bendixson Theorem
2021
We consider a C 1 vector field X defined on an open subset U of the plane, with compact closure. If X has no singular points and if U is simply connected, a weak version of the Poincaré-Bendixson Theorem says that the limit sets of X in U are empty but that one can defined non empty extended limit sets contained into the boundary of U. We give an elementary proof of this result, independent of the classical Poincaré-Bendixson Theorem. A trapping triangle T based at p, for a C 1 vector field X defined on an open subset U of the plane, is a topological triangle with a corner at a point p located on the boundary ∂U and a good control of the tranversality of X along the sides. The principal app…
On presentations for mapping class groups of orientable surfaces via Poincaré's Polyhedron theorem and graphs of groups
2021
The mapping class group of an orientable surface with one boundary component, S, is isomorphic to a subgroup of the automorphism group of the fundamental group of S. We call these subgroups algebraic mapping class groups. An algebraic mapping class group acts on a space called ordered Auter space. We apply Poincaré's Polyhedron theorem to this action. We describe a decomposition of ordered Auter space. From these results, we deduce that the algebraic mapping class group of S is a quotient of the fundamental group of a graph of groups with, at most, two vertices and, at most, six edges. Vertex and edge groups of our graph of groups are mapping class groups of orientable surfaces with one, tw…
COVID-19 Infection Process in Italy and Spain: Are the Data Talking?
2020
Background: COVID-19 has spread successfully worldwide in a matter of weeks. After the example of China, all the affected countries are taking hard-confinement measures to control the infection and to gain some time to diminish the big amount of cases that arrive to hospital. Although the measures in China reduced the percentages of new cases, this is not seen in other countries that have taken similar measures, such as Italy and Spain. Now we are in the middle of a battle trying to prevent the healthcare system from collapsing while it effectively responds to the needs of patients who are infected and require hospitalization. Methods: Using China as a mirror of what could happen in our cou…
Six Weeks of Confinement: Psychological Effects on a Sample of Children in Early Childhood and Primary Education
2020
Spain has been one of the countries most affected by the health crisis derived from COVID-19. Within this country, the city of Madrid has registered the highest number of infections and deaths. This circumstance led to the adoption of strict confinement measures for a period of 6 weeks. The objective of the present study was to investigate the psychological effects that this confinement has had on the psychological well-being of a sample of children from Madrid. A total of 167 families with children aged between 3 and 11 years participated in this study. The parents evaluated the children through the System of Evaluation of Children and Adolescents (SENA) scale in the month of February and …
An Italian Guidance Model for the Management of Suspected or Confirmed COVID-19 Patients in the Primary Care Setting
2020
An outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 started in China's Hubei province at the end of 2019 has rapidly become a pandemic. In Italy, a great number of patients was managed in primary care setting and the role of general practitioners and physicians working in the first-aid emergency medical service has become of utmost importance to coordinate the network between the territory and hospitals during the pandemic. Aim of this manuscript is to provide a guidance model for the management of suspected, probable, or confirmed cases of SARS-CoV-2 infection in the primary care setting, from diagnosis to treatment, applying also the recommendations of the Italian Society of Ge…
Field evaluation of a rapid antigen test (Panbio™ COVID-19 Ag Rapid Test Device) for the diagnosis of COVID-19 in primary healthcare centers
2020
AbstractWe evaluated the Panbio™ COVID-19 AG Rapid Test Device (RAD) for the diagnosis of COVID-19 in symptomatic patients attended in primary healthcare centers (n=412). Overall specificity and sensitivity of RAD was 100% and 79.6%, respectively, taking RT-PCR as the reference. SARS-CoV-2 could not be cultured from specimens yielding RT-PCR+/RAD- results.