Applying Prolog to Develop Distributed Systems

Development of distributed systems is a difficult task. Declarative programming techniques hold a promising potential for effectively supporting programmer in this challenge. While Datalog-based languages have been actively explored for programming distributed systems, Prolog received relatively little attention in this application area so far. In this paper we present a Prolog-based programming system, called DAHL, for the declarative development of distributed systems. DAHL extends Prolog with an event-driven control mechanism and built-in networking procedures. Our experimental evaluation using a distributed hash-table data structure, a protocol for achieving Byzantine fault tolerance, and a distributed software model checker - all implemented in DAHL - indicates the viability of the approach

The quest for identity: the role of objects in contemporary everyday life

The thesis explores the significance of material objects in the everyday life of contemporary individuals. It is suggested that the relationship between individuals and objects in modern /contemporary society is a peculiar one. This peculiarity derives from the essential and crucial role things play: they contribute to shape and support the individual's identity in a context of fragmentation of the work experience and of the whole life, of anonymity and depersonalization of social relations, of bureaucratization and accelerated change.In the first part of the dissertation the topic is discussed and developed mainly at a theoretical level. A revisitation of well -known authors intends to recover what has been said - explicitly or otherwise - on the social meanings and uses of objects in modern society. A review and critique of express discussions of the functions performed by objects - e.g., the literature on consumer behaviour, on possession and exchange of goods in different cultures, on the psychological and symbolical significance of things - provide the framework to understand the complexity of our relationship to things and the multiplicity of meanings and projections attached to them.In the second part of the dissertation the results of a small - scale, exploratory, qualitatively oriented, empirical investigation of people who experience a peculiar relationship to objects are discussed. Through the analysis of this empirical material several interesting features of our relationship to things emerge quite clearly: gender il differences in the way of relating to the material world; the limited relevance of the concept of status symbol to explain the reasons why we surround ourselves with objects; the great emotional significance attached to things; the essential role objects play in providing the individual with material for the presentation of one's self and to communicate symbolically with others.It is concluded that the analysis of the meanings and uses of objects in everyday life provides interesting elements to understand how the individual copes with the problems contemporary industrial society raises for the establishment and maintenance of personal identity

Massive stars exploding in a He-rich circumstellar medium - VIII. PSN J07285387+3349106, a highly reddened supernova Ibn

We present spectroscopic and photometric observations for the Type Ibn supernova (SN) dubbed PSN J07285387+3349106. Using data provided by amateur astronomers, we monitored the photometric rise of the SN to maximum light, occurred on 2015 February 18.8 UT (JD(max,V) = 2457072.0 +- 0.8). PSN J07285387+3349106 exploded in the inner region of an infrared luminous galaxy, and is the most reddened SN Ibn discovered so far. We apply multiple methods to derive the total reddening to the SN, and determine a total colour excess E(B-V)(tot) = 0.99 +- 0.48 mag. Accounting for the reddening correction, which is affected by a large uncertainty, we estimate a peak absolute magnitude of M(V) = -20.30 +- 1.50. The spectra are dominated by continuum emission at early phases, and He I lines with narrow P-Cygni profiles are detected. We also identify weak Fe III and N II features. All these lines show an absorption component which is blue-shifted by about 900-1000 km/s. The spectra also show relatively broad He I line wings with low contrast, which extend to above 3000 km/s. From about 2 weeks past maximum, broad lines of O I, Mg II and the Ca II near-infrared triplet are identified. The composition and the expansion velocity of the circumstellar material, and the presence of He I and alpha-elements in the SN ejecta indicate that PSN J07285387+3349106 was produced by the core-collapse of a stripped-envelope star. We suggest that the precursor was WNE-type Wolf-Rayet star in its dense, He-rich circumstellar cocoon.Comment: 12 pages, 7 figures, 2 tables. Accepted for publication in MNRA

The state of peer-to-peer network simulators

Networking research often relies on simulation in order to test and evaluate new ideas. An important requirement of this process is that results must be reproducible so that other researchers can replicate, validate and extend existing work. We look at the landscape of simulators for research in peer-to-peer (P2P) networks by conducting a survey of a combined total of over 280 papers from before and after 2007 (the year of the last survey in this area), and comment on the large quantity of research using bespoke, closed-source simulators. We propose a set of criteria that P2P simulators should meet, and poll the P2P research community for their agreement. We aim to drive the community towards performing their experiments on simulators that allow for others to validate their results

SNhunt151: An explosive event inside a dense cocoon

Indexación: Scopus.We thank S. Spiro, R. Rekola, A. Harutyunyan, and M. L. Graham for their help with the observations. We are grateful to the collaboration of Massimo Conti, Giacomo Guerrini, Paolo Rosi, and Luz Marina Tinjaca Ramirez from the Osservatorio Astronomico Provinciale di Montarrenti. The staffs at the different observatories provided excellent assistance with the observations.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 267251, ‘Astronomy Fellowships in Italy’ (AstroFIt)’. NE-R acknowledges financial support from MIUR PRIN 2010-2011, ‘The Dark Universe and the Cosmic Evolution of Baryons: From Current Surveys to Euclid’. NE-R, AP, SB, LT, MT, and GP are partially supported by the PRIN-INAF 2014 (project ‘Transient Universe: Unveiling New Types of Stellar Explosions with PESSTO’). GP acknowledges support provided by the Millennium Institute of Astrophysics (MAS) through grant IC120009 of the Programa Iniciativa Cientíifica Milenio del Ministerio de Economía, Fomento y Turismo de Chile. TK acknowledges financial support from the Emil Aaltonen Foundation. CRTS was supported by the NSF grants AST-0909182, AST-1313422, and AST-1413600. AVF is grateful for generous financial assistance from the Christopher R. Redlich Fund, the TABASGO Foundation, the Miller Institute for Basic Research in Science (UC Berkeley), and NASA/HST grant GO-14668 from the Space Telescope Science Institute, which is operated by AURA, Inc. under NASA contract NAS5-26555. The work of AVF was conducted in part at the Aspen Center for Physics, which is supported by NSF grantPHY-1607611; he thanks the Center for its hospitality during the neutron stars workshop in June and July 2017. NE-R acknowledges the hospitality of the ‘Institut de Ciències de l'Espai (CSIC), where this work was completed.This research is based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofísica de Canarias; the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma; the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the Fundaci Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias; the Liverpool Telescope, operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias with financial support from the UK Science and Technology Facilities Council; the 1.82-m Copernico Telescope and the Schmidt 67/92 cm of INAF-Asiago Observatory; the Catalina Real Time Survey (CRTS) Catalina Sky Survey (CSS) 0.7-m Schmidt Telescope; and the Las Cumbres Observatory (LCO) network. This work is also based in part on archival data obtained with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555; the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA (support was provided by NASA through an award issued by JPL/Caltech); and the Swift telescope.This work has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.SNhunt151 was initially classified as a supernova (SN) impostor (nonterminal outburst of a massive star). It exhibited a slow increase in luminosity, lasting about 450 d, followed by a major brightening that reaches M V ≈ -18 mag. No source is detected to M V ≳ -13 mag in archival images at the position of SNhunt151 before the slow rise. Low-to-mid-resolution optical spectra obtained during the pronounced brightening show very little evolution, being dominated at all times by multicomponent Balmer emission lines, a signature of interaction between the material ejected in the new outburst and the pre-existing circumstellar medium. We also analysed mid-infrared images from the Spitzer Space Telescope, detecting a source at the transient position in 2014 and 2015. Overall, SNhunt151 is spectroscopically a Type IIn SN, somewhat similar to SN 2009ip. However, there are also some differences, such as a slow pre-discovery rise, a relatively broad light-curve peak showing a longer rise time (~50 d), and a slower decline, along with a negligible change in the temperature around the peak (T ≤ 10 4 K). We suggest that SNhunt151 is the result of an outburst, or an SN explosion, within a dense circumstellar nebula, similar to those embedding some luminous blue variables like η Carinae and originating from past mass-loss events. © 2017 The Author(s).https://academic.oup.com/mnras/article/475/2/2614/479530

Vite diseguali nella pandemia

COVID-19 affects different social groups in unequal ways: from the older to the younger, from more (MD, nurses and manual worker in the tertiary sector) to less dangerous jobs. Economic conditions affect sanitary and poverty risks across fragile social groups, revealing a strong correlation between economic and health conditions. The social consequences of COVID are extremely serious and socially stratified: young people, irregular migrants, working mothers and poor children which had to handle everyday life in extreme economic, social, housing and cultural malaise.COVID-19 affects different social groups in unequal ways: from the older to the younger, from more (MD, nurses and manual worker in the tertiary sector) to less dangerous jobs. Economic conditions affect sanitary and poverty risks across fragile social groups, revealing a strong correlation between economic and health conditions. The social consequences of COVID are extremely serious and socially stratified: young people, irregular migrants, working mothers and poor children which had to handle everyday life in extreme economic, social, housing and cultural malaise

Translocational belonging in urban peripheries among the postmigrant generation: San Siro and the trap/drill subculture of Milan

This article investigates the construction of translocal belongings among postmigrant youth in urban peripheries, by analyzing the latter’s musical subculture treated as expressions of identity for racialized and marginalized young individuals. Focusing on the case of the trap ensemble Seven7oo associated with the San Siro neighborhood of Milan, an intertextual reading of everyday urban spaces, personal narratives, musical and social media content is undertaken to unpack core themes shaping identity constructions of postmigrant youth living in peripheral landscapes. This is done so through the triangulation of ethnographic fieldwork in the neighborhood of San Siro, online ethnography of Seven7oo members and their followers, in-depth interviews, and song lyrics treated as personal testimonies of children of immigrants growing up in marginalized areas of a rich European metropolis. It is argued that three themes are salient across different sources of data, namely a. situated childhood suffering as a glue for translocal collective identity, b. prevalence of translocational bonds against the negation of national belongings, and c. (digital) marketing of fast-track mobility in overcoming stigmatization and marginalization

“A Cathartic Moment in a Man’s Life”: Homosociality and Gendered Fun on the Puttan Tour

Rarely addressed in academic scholarship, the puttan tour is a well-known form of entertainment in Italy where young men drive around in small groups with the aim of spotting street sex workers. On some occasions, the participants will approach the sex workers to strike up a conversation. On others, they will shout out insults from their car then drive away. This article aims to advance a detailed analysis of this underexplored cultural practice drawing on a diverse body of scholarship exploring the intersection of masculinity, leisure, and homosociality. By analyzing stories of puttan tours gathered mostly online, including written accounts and YouTube videos, our aim is to explore the appeal of the puttan tour through an analysis of how homosociality, humor, and laughter operate in this example of gendered fun. To this end, we look at the multiple and often equivocal meanings of this homosocial male-bonding ritual, its emotional and affective dynamics, and the ways in which it reproduces structures of inequality while normalizing violence against sex workers

The language of food and intercultural exchanges and relationships

The article discusses the role of food as an instrument of identity and a channel of contact through cultures. This is discussed drawing from three cases of Italian food culture hybridization spanning from the early 20th century to the first decade of the 2000s: the role of Italian food in Italian-American identity as depicted in Leonardo Coviello\u201fs work, the meeting of Southern and Northern food cultures following the Italian internal migrations in the 50s and 60s, the food practices of international migrants in the context of the global flows of people and commodities in present day Italy. In this regard, food plays an essential role in the rebuilding of a familiar context in which migrants can feel temporarily \u201cat home\u201d. At the same time, food is an important form of communication and contact between different cultures and social contexts. In this process of exchange both migrants\u201f and hosts\u201f food habits and diets are modified as they incorporate elements and ingredients from each other, making boundaries more porous

Shifting Geographical Configurations in Migrant Families: Narratives of Children Reunited with their Mothers in Italy

Der Aufsatz untersucht die Erfahrungen von Trennung und Wiedervereinigung von Kindern und gewanderten Müttern in Italien anhand der Analyse von 32 qualitativen Interviews, durchgeführt mit Heranwachsenden, die zu unterschiedlichen Zeitpunkten ihres Lebens wieder mit ihren Müttern vereint wurden. Wir zeigen, dass internationale Migration die Ursache ist, dass Kinder mehrfach Veränderungen in der Zusammensetzung ihrer familiären Bindungen ausgesetzt sind, die aus der räumlichen Trennung und Wiedervereinigung resultieren, von der diese Bindungen abhängig sind. Die Art, in der Kinder diese Wechsel interpretieren und sich ihnen anpassen, hängt von Faktoren wie dem Zeitpunkt des familiären Wanderungsprozesses und der Häufigkeit transnationaler Familienpraktiken ab, die von den mehr oder weniger abrupten Unterbrechungen des Familienlebens nach der Abreise der Mutter und des Kindes beeinflusst werden.The article explores the experiences of separation and reunification by children of migrant mothers in Italy by analysing 32 qualitative interviews conducted with adolescents who had rejoined their mothers at different points in their lives. We show that international migration causes children to face multiple shifts in the configuration of their family ties due to the geographical dislocations and re-locations to which these ties are subject. The way in which children interpret and adjust to these changes depends on factors such as the timing of the family migration process and the frequency of transnational family practices, which are affected by more or less abrupt discontinuities in family life after their mothers’ and their own departure