223 research outputs found
Intraspecific variability drives diversity in food webs
Biodiversity theories neglect individual-level variability in ecological interactions even though empirical work has revealed considerable genetic and phenotypic variation among individuals in natural populations. This impedes assessing the impact of individual-level variability on biodiversity in multi-trophic ecosystems. Here we use a density-dependent and individual-based food web model, tested against the largest individual-based food web to date, to show that non-random intraspecific variation in prey selection alters species diversity in food webs. Predators consuming many prey increase diversity by preferentially selecting common prey; predators consuming few prey inhibit diversity by preferentially selecting rare prey, putting them at risk of extinction. Thus species-level patterns cannot be explained by species-level averages, but instead must consider individual-level variation in prey selection. Individual-level variation occurs in many biological and social contexts, suggesting that analyses of individual-level interaction data will be relevant in a wide range of fields
Understanding the links between diversity and creativity as assessed in the boroughs of London
This paper analyses the links between creativity and diversity in the different boroughs of London. Based on rich data from the UK Census of Population of 2011 and other sources, we specifically analysed the correlations between creativity and diversity within the London boroughs. The main results of this study indicate that there is no direct correlation between creativity and diversity. Some significant correlations have been observed, however, between variables that shape such indices. Namely, the “creative class” tend to live in more diverse, more heterogeneous neighbourhoods (alongside people from many different countries) and they are more prepared to tolerate such diverse environments. The study also shows that diversity of geographical origin (measured by country of origin) is a more relevant factor for boosting creativity than variables such as religious diversity. This article contributes to the theoretical field of research exploring the impact of diversity on creative people and cities
On infrastructure for facilitation of inner source in small development teams
The phenomenon of adopting open source software development practices in a corporate environment is known by many names, one being inner source. The objective of this study is to investigate how an organization consisting of small development teams can benet from adopting inner source and assess the level of applicability. The research has been conducted as a case study at a software development company. Data collection was carried out through interviews and a series of focus group meetings, and then analyzed by mapping it to an available framework. The analysis shows that the organization possesses potential, and also identied a number of challenges and benets of special importance to the case company. To address these challenges, the case study synthesized the organizational and infrastructural needs of the organization in a requirements specication describing a technical infrastructure, also known as a software forge, with an adapted organizational context and work process
System architecture of Intelligent Monitoring in multi-domain orchestration
Orchestrating a service or resources across multiple administrative domains requires three main high level steps of operation: i) capability detection of other domains ii) placement of the service request across the domains iii) assurance that the service is functioning within the acceptable bounds of the service level agreement (SLA). This paper focuses on the assurance step; in particular, we present a novel architecture and preliminary implementation that supports monitoring of KPIs across multiple administrative domains. The challenges towards realising such an architecture are: i) coordinated monitoring with no direct access to the other domain's infrastructure ii) monitoring over an abstracted (instead of actual) topology that each administrative domain may expose to other domains iii) different domains have different systems for monitoring with different KPIs as well as different ways of measuring those KPI. Our architecture, referred to as IMoS addresses these challenges to provide an end-to-end monitoring as a fundamental functionality for supporting assurance and SLA management for services orchestration across multi-administrative-domains. In addition, the preliminary results are provided from the first proof of concept implementation of an IMoS. The work done in this paper has been developed within the H2020 ICT14 project 5G Exchange
Finite to infinite steady state solutions, bifurcations of an integro-differential equation
We consider a bistable integral equation which governs the stationary
solutions of a convolution model of solid--solid phase transitions on a circle.
We study the bifurcations of the set of the stationary solutions as the
diffusion coefficient is varied to examine the transition from an infinite
number of steady states to three for the continuum limit of the
semi--discretised system. We show how the symmetry of the problem is
responsible for the generation and stabilisation of equilibria and comment on
the puzzling connection between continuity and stability that exists in this
problem
Health Hazard from Gas Emissions in the Quaternary Volcanic Province of Latium (Italy)
The Quaternary Volcanic Province of Central Italy is characterized by zones with a huge endogenous degassing where frequent, sometimes lethal, accidents occur to people and animals. The emitted gas has a deep origin (volcanic or mantle) and is mainly composed by CO2 (up to 98%) and H2S (1-4%), which may reach dangerous concentrations both in open air and indoor. Here we present the results of a multiparametric geochemical study carried out in 2007-2009 in the Provinces of Rome and Viterbo (Latium), with the aim of assessing the health hazard of their main gas emission sites (GES). Three types of GES were investigated: 1. natural, open-air thermal pools, 2. within natural reserves, 3. near to inhabited zones. More than 15 GES have been studied, and here we will illustrate some of the cases with the highest hazard. Results are presented for the sites of Vejano and Mola di Oriolo (Viterbo), Caldara di Manziana, Tor Caldara and Solforata di Pomezia (Rome). Cava dei Selci is a well-known inhabited area of the volcanic complex of Colli Albani (Rome). In each site, multi-technique surveys have been carried out to estimate the total gas output and its concentration in air, by measuring: CO2 and H2S viscous and diffuse flux (the latter by accumulation chamber), CO2 and H2S concentration in air (by TDL profiles and punctual Draeger measurements); moreover, the chemical and isotopic composition of the gas was determined in each site. In all these zones, lethal air concentrations may be reached by both H2S and CO2, but more frequently by the first. Recommendations for risk reduction were given to Civil Protection authorities.Comission of Cities and Volcanoes (CaV) of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) Agencia Española de Cooperación Internacional para el Desarrollo (AECID), Gobierno de España Ministerio de Ciencia e Innovación (MICINN), Gobierno de España
Unidad Militar de Emergencias (UME), Ministerio de Defensa, Gobierno de España
Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI), Gobierno de Canarias Viceconsejería de Infraestructuras y Planificación, Gobierno de Canarias Consejería de Turismo, Gobierno de Canarias Consejería de Medio Ambiente y Ordenación Territorial, Gobierno de Canarias
Viceconsejería de Cultura y Deportes, Gobierno de Canarias Instituto Español de Oceanografía (IEO)Instituto Geológico y Minero de España (IGME)Instituto Geográfico Nacional (IGN)Academia Canaria de Seguridad
Federación Canaria de Municipios (FECAM)
Universidad de La Laguna (ULL)Instituto de Estudios Hispánicos de Canarias (IEHC)
CajaCanariasPublishedPuerto de la Cruz, Tenerife, Spain1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive4.5. Studi sul degassamento naturale e sui gas petroliferiope
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