1,990 research outputs found
Mitigation technologies for counteracting the UHI effects and for improving outdoor thermal comfort in mediterranean urban open spaces: a study of vegetation and cool materials effects on pedestrian comfort in Rome
The present study investigates the influence of building materials, traditional as well as innovative,
and vegetated urban surfaces on the urban microclimate and on pedestrian outdoor thermal comfort in
a typical Mediterranean city: Rome. It focuses the attention on selected mitigation technologies aiming
to increase the albedo of cities: high reflective materials called cool colored materials, and the use of
vegetative surfaces: green roofs, green walls and trees, with the main purpose to test, verify and
quantify the overall microclimate mitigation and thermal performance of the aforementioned strategies,
The study proposes and analyses, through CFD calculations (ENVImet v.4.0), five renovations
scenarios: applying cool materials and vegetation on roofs, walls and pavements of the selected square.
In order to support planning authorities and researches by going beyond the traditional way of urban
heat island studies, the present study aims to highlight the multiple effects of cool colored materials on
human comfort and to investigates which could be the best combination materials in terms of
mitigation of ambient temperatures and pedestrian thermal stress. Therefore, air temperature as well
as the physiologically equivalent temperature (PET) were applied to take into account the effect of the
variations of urban materials on human comfort, the studies focuses the attention and draw its
conclusions through the comparison of the Envimet thermal maps and the values of the different
scenarios in terms of deltas variations. The results show the negative effect of cool colored materials
on human thermal comfort when applied isolated to surfaces in direct contact with pedestrians, such as
pavements and urban façades, nevertheless it underlines the benefit associated with a mixed
combination of cool materials and trees, setting the path for further research in this direction
Income Polarization, Convergence Tools and Mixture Analysis
Modeling the cross-country distribution of per capita using mixture analysis provides a natural platform for the recovery or detection of clubs of countries. Unfortunately, these mixture methods, when based on a strictly univariate approach are limiting towards one's ability to learn about the underlying process of the emergence of the clubs. This paper takes a fresh look at the sources contributing to the emergence of clubs in the distribution of cross-country output using bivariate and multivariate mixture analysis.Convergence, Orientation, Mixture Densities
Decomposing The Conditional Variance of Cross-Country Output
A well established fact in the growth empirics literature is the increasing variation in output per capita across countries. This phenomena however does not adequately describe changes in the distribution of output since it does not account for changes in the covariates which undoubtedly in influence per capita output levels. We propose a robust, nonparametric decomposition of the conditional variation of per capita output and find that OECD countries have experienced diminishing conditional variation while other regions have experienced increasing conditional variation. Our decomposition suggests that most of these changes in the conditional variance of output is due to unobserved factors not accounted for by the traditional growth determinants. In addition to this we show as these factors played very different roles over time and across regions.Generalized Kernel, Nonparametric, Conditional Variation
Benchmarking multi-criteria evaluation methodology's application for the definition of benchmarks in a negotiation-type public-private partnership. A case of study: The integrated action programmes of the Lazio Region
The growing scarcity of public financial in Italy, in opposition of the more significant problems of degradation of many urban areas, prompted the Legislature to standardise new processes of settlement transformation based on negotiation-type public-private partnerships (PPPN). However, these standards have not provided for benchmarks referring to the contents of partnerships or assessment procedures aimed at assessing the initiatives undertaken with respect to public utility objectives. This has often led to redevelopment initiatives geared more towards the satisfaction of private rather than public interests. The proposed methodology, structured on the integration of a benchmarking process with multi-criteria evaluation techniques known as benchmarking multi-criteria evaluation (BME) enables the definition of benchmarks through a participatory process of the different stakeholders involved in a PPPN to which the BME is applied. In order to verify the applicability of the proposed procedure, it has been applied to a type of PPPN: the integrated action programmes (PII) in the Lazio Region. The benchmarks can be used by Lazio’s administrators both for renewing the planning of the PII concerned and for verifying the quality of the initiatives within the same PPPN proces
Probing the formation history of the nuclear star cluster at the Galactic Centre with millisecond pulsars
The origin of the Nuclear Star Cluster in the centre of our Galaxy is still
unknown. One possibility is that it formed after the disruption of stellar
clusters that spiralled into the Galactic Centre due to dynamical friction. We
trace the formation of the Nuclear Star Cluster around the central black hole,
using state-of-the-art N-body simulations, and follow the dynamics of the
neutron stars born in the clusters. We then estimate the number of Millisecond
Pulsars (MSPs) that are released in the Nuclear Star Cluster, during its
formation. The assembly and tidal dismemberment of globular clusters lead to a
population of MSPs distributed over a radius of about 20 pc, with a peak near 3
pc. No clustering is found on the sub-parsec scale. We simulate the
detectability of this population with future radio telescopes like the MeerKAT
radio telescope and SKA1, and find that about of order ten MSPs can be observed
over this large volume, with a paucity of MSPs within the central parsec. This
helps discriminating this scenario from the in-situ formation model for the
Nuclear Star Cluster that would predict an over abundance of MSPs closer to the
black hole. We then discuss the potential contribution of our MSP population to
the gamma-ray excess at the Galactic Centre.Comment: 11 pages, 8 figures, accepted for publication in MNRA
Pestilence, persistence and pathogenicity: infection strategies of Bartonella
It has been nearly two decades since the discovery of Bartonella as an agent of bacillary angiomatosis in AIDS patients and persistent bacteremia and \u27nonculturable\u27 endocarditis in homeless people. Since that time, the number of Bartonella species identified has increased from one to 24, and 10 of these bacteria are associated with human disease. Although Bartonella is the only genus that infects human erythrocytes and triggers pathological angiogenesis in the vascular bed, the group remains understudied compared with most other bacterial pathogens. Numerous questions regarding Bartonella\u27s molecular pathogenesis and epidemiology remain unanswered. Virtually every mammal harbors one or more Bartonella species and their transmission typically involves a hematophagous arthropod vector. However, many details regarding epidemiology and the public health threat imposed by these animal reservoirs is unclear. A handful of studies have shown that bartonellae are highly-adapted pathogens whose parasitic strategy has evolved to cause persistent infections of the host. To this end, virulence attributes of Bartonella include the subversion of host cells with effector molecules delivered via a type IV secretion system, induction of pathological angiogenesis through various means, including inhibition of apoptosis and activation of hypoxia-inducing factor 1, use of afimbrial adhesins that are orthologs of Yersinia adhesin A, incorporation of lipopolysaccharides with low endotoxic potency in the outer membrane, and several other virulence factors that help Bartonella infect and persist in erythrocytes and endothelial cells of the host circulatory system
Eco-efficient and sustainable settlement experimentation in Mediterranean housing
Eco-efficient and sustainable settlement experimentation in Mediterranean housing
Settlement experimentation in Europe is currently characterised by the attempt to promote energy efficient and environmentally sustainable housing in an evolutionary, organic and integrated sense; this approach could become a guiding tool for the transformation of the built environment, the latter consisting in the development and construction of a urban environment that shows sensibility towards ecological-environmental issues and social ones.
The focal points of such research experiences are housing projects built in Northern and Central European countries; the latter being very interesting projects that have become models for the rest of EU countries, showing what can be obtained in the contemporary experimentation field. In respect to these study cases, now all we need is to find ways to transfer the acquired knowhow in Mediterranean countries and therefore to adapt the new sustainable strategies to the Mediterranean climate. In this framework the paper wishes to offer an exploration on a research case study, carried out in central Italy, about the development of Mediterranean sustainable development
Development of a System for Genetic Manipulation of Bartonella Bacilliformis
Lack of a system for site specific genetic manipulation has severely hindered studies on the molecular biology of all Bartonella species. We report the first site-specific mutagenesis and complementation for a Bartonella species. A highly transformable strain of B. bacilliformis, termed JB584, was isolated and found to exhibit a significant increase in transformation efficiency with the broad-host-range plasmid pBBR1MCS-2, relative to wild-type strains. Restriction analyses of genomic preparations with the methylation-sensitive restriction enzymes ClaI and StuI suggest that strain JB584 possesses a dcm methylase mutation that contributes to its enhanced transformability. A suicide plasmid, pUB1, which contains a polylinker, a pMB1 replicon, and a nptI kanamycin resistance cassette, aas constructed. An internal 508-bp fragment of the B. bacilliformis flagellin gene (fla) was cloned into pUB1 to generate pUB508, a fla-targeting suicide vector. Introduction of pUB508 into JB584 by electroporation generated eight Kan(r) clones of B. bacilliformis, Characterization of one of these strains, termed JB585, indicated that allelic exchange between pUB508 and fla had occurred. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and electron microscopy showed that synthesis of flagellin encoded by fla and secretion/assembly of flagella were abolished. Complementation of fla in trans was accomplished with a pBBR1MCS recombinant containing the entire wild-type fla gene (pBBRFLAG), These data conclusively show that inactivation of fla results in a bald, nonmotile phenotype and that pMB1 and REP replicons make suitable B. bacilliformis suicide and shuttle vectors, respectively. When used in conjunction with the highly transformable strain JB584, this system for site-specific genetic manipulation and complementation provides a new venue for studying the molecular biology of B. bacilliformis
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