Riviste Online SApienza - R.O.SA - 2 (Sapienza University of Rome)
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An integrated approach to casuality: the role of casual graphs
Get PDFCausal questions are central for most biomedical and social science studies. The main frameworks that allow the analysis of causal relations are Potential Outcomes and Causal Graphs. The approaches have often been compared, contrasting their relative strengths. This paper evaluates the implications of merging the two methodologies in an integrated approach. In particular, we assess how the limits of one can be compensated by the solutions provided by the other. The outlined approach employs causal graphs to discover and formalize a causal model that is then used as a guide to implementing potential outcomes identification strategies. The integrated approach could be beneficial to both frameworks. The assumptions of potential outcome methods can be assessed directly from a causal graph even in high dimensional contexts, thus making the obtained causal estimates more reliable. On the other hand, causal graphs can benefit from the several ad hoc identification strategies that have been developed in the potential outcomes literature
European migration policies between restrictions and few rights. The case of the Balkan route
Get PDFThe rise of new migratory routes in the world has represented a response to the unsuccessful strategies adopted by States in the field of people mobility. The Balkan route, in Eastern Europe, came out from the migration crisis in 2015 and continues until today. The main goal of this note is to provide a detailed literature about the policies adopted by the States to manage migration along Balkan countries. It is also the aim of this paper to demonstrate how policies have produced changes in the route, violating the fundamental human rights and not reducing the number of people trying to cross the borders to reach Europe but rather creating categories of marginalized people in marginalized places
An overview on dynamic optimal portfolio allocation
No full textA portfolio allocation problem relies upon the decision process to establish how resources must be allocated among different possible investments. Investors are interested in gaining as much as possible from their investment, but at the same time they are concerned with risks they have to face. The aim of investors is to maximize their returns without exceeding a certain level of risk. Moreover this behaviour has to be mathematically modeled, resorting to the optimal control theory and the maximization of expected utility. This paper reviews the literature on the portoflio allocation, in order to give a complete picture of what has been done, as well as, possible contributions for future research
La questione nazionale in Europa centro-orientale
Get PDFIn seguito ai trattati di Versailles, la presenza di diverse minoranze nazionali all’interno degli Stati dell’Europa centro-orientale rappresentò una delle questioni più delicate e controverse per la stabilità dell’intera regione. Di conseguenza, sulla scia delle analoghe problematiche che avevano caratterizzato la Guerra Civile in Russia, il Comintern orientò la propria politica in tale area verso la piena affermazione del principio di auto-determinazione nazionale. Come si cercherà di evidenziare, questa scelta ebbe conseguenze non sempre positive all’interno degli stessi partiti comunisti e contribuì a rendere la loro posizione all’interno dei singoli Stati ancora più precaria. La questione nazionale rappresentò comunque un vivace argomento di discussione e diede vita a esperienze interessanti come quella della federazione balcanica e alla definizione di nuovi progetti identitari. Anche in questo campo, ad ogni modo, la politica del Comintern andò tuttavia evolvendosi a cavallo fra anni Venti e Trenta e finì con l’adattarsi alle linee di politica estera di Mosca
La mobilitazione internazionalista, il caso della guerra di Spagna
Get PDFDopo una breve riflessione di carattere generale sull’abbondante produzione e sui dibattiti storiografici esistenti sul tema, l’articolo analizzerà brevemente quattro aspetti. In primo luogo la lettura che il Comintern fece della situazione spagnola prima dello scoppio della guerra e le ragioni che portarono ad un impegno determinato nella difesa della Repubblica Spagnola minacciata dal golpe dell’estate del 1936. L’intervento, inserito nella strategia dei Fronti Popolari, ebbe delle caratteristiche, che proiettavano in maniera decisa l’immagine di un movimento comunista impegnato nella difesa della democrazia. In secondo luogo, verrà analizzata l’azione del Comintern durante la guerra. Ci si soffermerà sulla costruzione delle Brigate Internazionali: la struttura direttiva ed organizzativa messa in campo per realizzare uno sforzo di solidarietà internazionale senza precedenti, e la loro azione militare, impegnate sui fronti del Jarama, Guadalajara, Brunete, Belchite, Teruel, Aragona ed Ebro, prima dello scioglimento e della ritirata dei combattenti stranieri nel novembre del 1938. Si terrà conto anche dell’azione politica del Comintern e dei suoi dirigenti nell’ambito della vita politica repubblicana, in particolar modo nel conflitto della primavera del 1937. Infine, l’articolo proporrà una riflessione sulla memoria dell’azione del Comintern e delle Brigate Internazionali durante la guerra spagnola, soprattutto durante la Guerra Fredda
Problems and solutions for the management of a unitary system of landslide monitoring networks: an experience in North Italy
No full textInternational scientific studies show that landslides are widespread throughout Europe, especially in Italy (Herrera et alii, 2018; Trigila et alii, 2007). Due to the phenomenon high dimension, it’s not possible to act in all the areas with structural operations to reduce the landslides risk. For this reason, the geological monitoring networks represent an efficacious and cost-effective system to protect the population. ARPA Lombardia, with Geological Monitoring Centre (CMG), has worked for the last years for the management of dozens of early warning geological monitoring networks. CMG has been monitoring a total of 44 landslide areas and has been collecting and analysing about 25 million data for the last years. These data are acquired by sensors every 10 or 30 minutes. This paper will take in consideration the essential and critical aspects linked to the planning, integration and unitary management of numerous monitoring networks to control landslides. The CMG’s experience has shown how the unitary management of the warning systems of multiple monitoring networks is the ideal method to manage landslides problem and reduce hazard. This paper highlights how the technician’s formation on landslides and geological monitoring networks has allowed better management of the landslide risk problem. Finally, it is quantitatively demonstrated that management costs show significant reductions after the implementation of this unitary management
Nest architectures of myrmecophilous stingless bees, Trigona cfr. cilipes and Paratrigona sp., from Peruvian Amazon
No full textStingless bees (Hymenoptera: Meliponini) are corbiculate and eusocial bees, including over 500 species distributed in the tropical and sub-tropical regions of the world. They establish perennial colonies using a large variety of nesting sites, as well as colonies of ants, wasps and termites. Compared to termitophily, myrmecophily is an uncommon feature and little studied aspect among Meliponini. In Peru there are few records relating to these types of associations, and in general little is known about the architecture of the nests of bees and ants that live together. For the first time, the nest architecture of Trigona cfr. cilipes in association with Dolichoderus quadridenticulatus is described from the Peruvian Amazon. The record of another association, Paratrigona sp. - Camponotus sp. is also reported. As the nests are arranged, the types of building materials used and some behavioral defense observations of ants and bees are also provided
A new taxon of the soldier beetles’ genus †Poinarelektronmiles from Burmese amber (Coleoptera: Cantharidae)
Get PDFPoinarelektronmiles cuaroni sp. n., a new fossil species of soldier beetles from the Cretaceous Burmese amber is diagnosed and illustrated, in this document. It is characterized by the antennomeres V-IX with an extremely long antennal process, and the last antennomere is very robust. Unlike what some authors have recently proposed, and as in other genera of Cretaceous soldier beetles, the antennal processes are evidently inserted at the apex of the antennomeres, in the intersegmental zone between the apex and the base of the next antennomere
Contributions to the knowledge of tiger beetles in Paraguay, with new country and departmental records (Coleoptera: Cicindelidae)
Get PDFWe report on four new country records of tiger beetles in Paraguay and 22 new departmental records based on specimens in Paraguayan collections. We also provide substantial increases to the knowledge on distributions of numerous species in the country through additional specimen records. The first tiger beetle records from south- western Ñeembucú are also provided. New country records are illustrated and comments on previous works dealing with the Paraguayan Cicindelid fauna are summarised
Orthopteran diversity and distribution in the Monviso Natural Park (Western Italian Alps) (Insecta: Orthoptera)
No full textThe Alps represent a biodiversity hotspot in Europe, especially due to the occurrence of many endemic plant and animal species. In particular, the southwestern portions of the Alpine range have been identified as a centre of endemism for many taxa, including Orthoptera, thanks to the peculiar biogeographical history of this area. In this research, the orthopteran fauna living in one of the main massifs of the Italian western Alps (Monviso massif, Cottian Alps) was investigated, focusing on the Monviso Natural Park and the SAC/SPA IT1160058 “Gruppo del Monviso e Bosco dell’Alevé” territories. Merging field data with information gathered from bibliographical sources, public and private databases, a checklist of 51 species was compiled for the study area, including 7 W-Alpine endemic species and 4 Near-threatened taxa according to the European IUCN orthopteran Red List. Species distribution has been mapped in detail within the park, identifying core areas for endemic and near-threatened species, as well as for the overall orthopteran diversity, where desirable research and conservation efforts should be focused in future. In addition, combining field data with the information obtained by means of a little systematic review, the known elevation extremes of 43 orthopteran species observed in the study area are updated for the W-Alpine region, significantly improving the current knowledge on their altitudinal distribution in this area, especially in view of the upward range shifts expected in the ongoing climate change scenario