1,525 research outputs found
The distinctive determinants of European urban growth: Does one size fit all?
This paper investigates growth differences in the urban system of the EU12. Alternative dependent variables - growth in population and real GDP per capita - are analysed and instructive differences emerge. The US model which assumes perfect factor mobility does not seem well adapted to European conditions. There is evidence strongly suggesting that equilibrating flows between cities are highly constrained in the EU. Models in which growth of real GDP p.c. are the dependent variable perform well and make it possible to test significant hypotheses. Evidence is found which is supportive of a spatial adaptation of the endogenous growth model with the relative size of the university sector having a highly significant role in explaining growth differences. In addition the analysis supports the conclusion that systems of urban governance are strongly related to growth. The variables are formulated in a way which tests hypotheses derived from 'fiscal federalism' viewing growth promotion as the production of a local public good. While international factor flows appear to be constrained as an adjustment mechanism the density of urbanisation in regions of the EU12 seems to produce a strong local 'growth shadow' effect consistent with commuting flows having an important role in spatial economic adjustment processes. Finally new evidence is found supporting the conclusion that integration shocks in the EU favour core areas but that this effect tends to fade with time.
The energy-oriented management of public historic buildings: An integrated approach and methodology applications
In the European framework, there is a strong drive to develop integrated approaches aimed at understanding and improving the energy behavior of public historic buildings within urban contexts. However, the examples already provided tend to address the issue from mono-disciplinary perspectives, losing the opportunity for a coordinated view. The research suggests a methodology to reach the definition of a three-dimensional database, which incorporates spatial models and energy information, with the final goal of merging heterogeneous information that is useful to interpret the overall framework and to design sustainable development scenarios. The platform achieves GIS (Geographic Information System) and BIM (Building Information Modeling) integration by using the CityGML data model, for supporting multi-scale analyses without break of continuity, ranging from urban to building level. The discussion combines the applicative case with the theoretical background, deepening the role of a solid knowledge framework as a basis for sustainable interventions on public historic buildings. To better explain and test the methodology, a case study on the University built heritage of Pavia is presented and three possible outputs deriving from the database are discussed. The example demonstrates the strength of the approach, which is able to provide a variety of results coming from a unique source of information, ensuring coherence and unambiguousness at all levels of investigation
Pro-inflammatory and anti-inflammatory circulating cytokines and periprosthetic osteolysis
We investigated the circulating levels of the main cytokines involved in bone resorption (IL-1β, IL-6, TNF-α), prostaglandins (PGE2) and metalloproteases (MMP-1), as possible early markers of osteolysis, in the serum of eight patients with periprosthetic osteolysis and ten patients without osteolysis. All had received a cementless hip prosthesis (ABG-1). We also assessed the serum levels of IL-11 and TGF-β anti-inflammatory cytokines exerting protective effect on bone resorption. The mean serum levels of IL-1β, IL-6, TNF-α, TGF-β, MMP-1, and PGE2 in patients with periprosthetic osteolysis did not differ significantly from those of patients without osteolysis or from those of normal controls. IL-11 serum levels were not detectable at all in any of the patients, while they were detected within normal reference values in the control subjects (significant inverse correlation). We believe that circulating cytokines cannot be regarded as markers of osteolysis, a condition characterised by a local inflammation without systemic signs of inflammation. On the contrary, the undetectable levels of IL-11 in implanted patients could provide evidence for a lack of balance between pro- and anti-inflammatory cytokines in these patients
Municipal solid waste prevention: A review of market-based instruments in six European Union countries
This article focuses on quantitative prevention of municipal solid waste among the 28 member countries of the European Union. A strict definition of waste prevention is used, including waste avoidance, waste reduction at source or in process, and product reuse, while recycling is outside the scope of this article. In order to provide a solid overview of the European situation, the study selected six countries (Belgium, Bulgaria, Italy, the Netherlands, Romania and Spain). Several selection requirements have been considered, such as geographic location or municipal solid waste per capita production trends from 1995 to 2017. A review of prevention programmes and other national strategic documents has been conducted. Extended producer responsibility, Pay-As-You-Throw schemes, Deposit-Refund Systems and Environmental Taxes implementation among the selected countries have been studied in order to understand how these market-based instruments can be used for the sake of waste prevention. Each market-based instrument has been further analysed using the Drivers Pressures State Impact Response model. Based on the results of this study, the effectiveness of market-based instruments implementation is strictly related to the context they are enforced in. It is particularly important to tailor the market-based instruments based on the implementation area. Nevertheless, market-based instruments, which are now mostly meant to boost the recycling sector of the considered Member States, should be designed to improve waste prevention performances, ensuring the achievement of the highest level of waste hierarchy promoted by the European Union
Conceptual-level evaluation of a variable stiffness skin for a morphing wing leading edge
A morphing leading edge produces a continuous aerodynamic surface that has no gaps between the moving and fixed parts. The continuous seamless shape has the potential to reduce drag, compared to conventional devices, such as slats that produce a discrete aerofoil shape change. However, the morphing leading edge has to achieve the required target shape by deforming from the baseline shape under the aerodynamic loads. In this paper, a conceptual-level method is proposed to evaluate the morphing leading edge structure. The feasibility of the skin design is validated by checking the failure index of the composite when the morphing leading edge undergoes the shape change. The stiffness of the morphing leading edge skin is spatially varied using variable lamina angles, and comparisons to the skin with constant stiffness are made to highlight its potential to reduce the actuation forces. The structural analysis is performed using a two-level structural optimisation scheme. The first level optimisation is applied to find the optimised structural proper- ties of the leading edge skin and the associated actuation forces. The structural properties of the skin are given as a stiffness distribution, which is controlled by a B spline interpolation function. In the second level, the design solution of the skin is investigated. The skin is assumed to be made of variable stiffness composite. The stack sequence of the composite is optimised element-by-element to match the target stiffness. A failure criterion is employed to obtain the failure index when the leading edge is actuated from the baseline shape to the target shape. Test cases are given to demonstrate that the optimisation scheme is able to provide the stiffness distribution of the leading edge skin and the actuation forces can be reduced by using a spatially variable stiffness skin
Weathering Effects on Engineering Geological Properties of Trachydacitic Volcanic Rocks from the Monte Amiata (Southern Tuscany, Italy)
Variability in lithology and weathering degree affects physical and mechanical properties
of rocks. In this study, we investigated the relationships between weathering degree and engineering
geological properties of trachydacitic volcanic rocks from Monte Amiata (central Italy) by coupling
field and laboratory analyses. We collected in situ Schmidt hammer tests in the field. We evaluated
weathering quantifying the percentage of secondary minerals through thermal analysis in the
laboratory. We also determined dry density (rd), specific gravity of solids (Gs), porosity (n) and
two-dimensional (2D) porosity as resulted from scanning electron microscopy investigations. The
results of our study indicate a negative linear correlation between Schmidt hammer rebound values
and secondary mineral percentage. This correlation provides a tool to quantitatively estimate the
deterioration of rock uniaxial compressive strength (UCS) as weathering increases. Moreover, thermal
analysis turned out to be a quantitative and reproducible method to evaluate weathering degree of
magmatic rocks
Atomic and Molecular Data for Optical Stellar Spectroscopy
High-precision spectroscopy of large stellar samples plays a crucial role for
several topical issues in astrophysics. Examples include studying the chemical
structure and evolution of the Milky Way galaxy, tracing the origin of chemical
elements, and characterizing planetary host stars. Data are accumulating from
instruments that obtain high-quality spectra of stars in the ultraviolet,
optical and infrared wavelength regions on a routine basis. These instruments
are located at ground-based 2- to 10-m class telescopes around the world, in
addition to the spectrographs with unique capabilities available at the Hubble
Space Telescope. The interpretation of these spectra requires high-quality
transition data for numerous species, in particular neutral and singly ionized
atoms, and di- or triatomic molecules. We rely heavily on the continuous
efforts of laboratory astrophysics groups that produce and improve the relevant
experimental and theoretical atomic and molecular data. The compilation of the
best available data is facilitated by databases and electronic infrastructures
such as the NIST Atomic Spectra Database, the VALD database, or the Virtual
Atomic and Molecular Data Centre (VAMDC). We illustrate the current status of
atomic data for optical stellar spectra with the example of the Gaia-ESO Public
Spectroscopic Survey. Data sources for 35 chemical elements were reviewed in an
effort to construct a line list for a homogeneous abundance analysis of up to
100000 stars.Comment: Published 30 April 2015 in Physica Script
Consumption of oral antibiotic formulations for young children according to the WHO Access, Watch, Reserve (AWaRe) antibiotic groups: an analysis of sales data from 70 middle-income and high-income countries
Background
The 2017 WHO Model List of Essential Medicines for Children (EMLc) groups antibiotics as Access, Watch, or Reserve, based on recommendations of their use as first-choice and second-choice empirical treatment for the most common infections. This grouping provides an opportunity to review country-level antibiotic consumption and a potential for stewardship. Therefore, we aimed to review 2015 levels of oral antibiotic consumption by young children globally.
Methods
We analysed wholesale antibiotic sales in 70 middle-income and high-income countries in 2015. We identified oral antibiotic formulations appropriate for use in young children (defined as child-appropriate formulations [CAFs]) using wholesale data from the IQVIA-Multinational Integrated Data Analysis System database, and we estimated 2015 antibiotic consumption in reference to the 2017 WHO EMLc Access, Watch, Reserve (AWaRe) antibiotic groups. We used three metrics for assessment of intra-country patterns: access percentage, defined as the number of CAF standard units of Access antibiotics divided by the total number of CAF standard units; amoxicillin index, defined as the number of amoxicillin CAF standard units divided by the total number of CAF standard units; and access-to-watch index, defined as the ratio of Access-to-Watch CAF standard units.
Findings
The overall median volume of CAF antibiotic standard units sold in 2015 per country was 74·5 million (IQR 12·4–210·7 million). The median access percentage among the 70 countries was 76·3% (IQR 62·6–84·2). The amoxicillin index was low (median 30·7%, IQR 14·3–47·3). The median access-to-watch index was 6·0 (IQR 3·1–9·8). CAF antibiotic consumption patterns were highly variable between the 70 countries, without a clear difference between high-income and middle-income countries.
Interpretation
Antibiotics in the Access group have a key role in treating young children globally. A simple combination of metrics based on the AWaRe groups can be informative on individual countries' patterns of antibiotic consumption and stewardship opportunities. These metrics could support countries in the development of programmes to improve access to core Access antibiotics, particularly amoxicillin.
Funding
Global Antibiotic R&D Partnership (German Federal Ministry of Health, Médecins Sans Frontières, Netherlands Ministry of Health, Welfare and Sport, and UK Department for International Development)
Young stellar clusters and associations in M33
We analyse multi-wavelength observations of 32 young star clusters and
associations in M33 with known oxygen abundance (8 < 12 + log(O/H) < 8.7),
using ultraviolet (UV), optical, mid-infrared (MIR), CO (1-0) and 21-cm line
(HI) observations. We derive their spectral energy distribution, and we
determine age, bolometric luminosities, masses and the extinction, by comparing
the multi-band integrated photometry to single-age stellar population models.
The stellar system ages range between 2 and 15 Myr, masses are between 3 x 10^2
and 4 x 10^4 M_sun, and the intrinsic extinction, A_V, varies from 0.3 to 1
mag. We find a correlation between age and extinction, and between the cluster
mass and size. The MIR emission shows the presence of a dust component around
the clusters whose fractional luminosity at 24 um, L_{24}/L_{Bol}, decreases
with the galactocentric distance. However, the total IR luminosity inferred
from L_{24} is smaller than what we derive from the extinction corrections. The
Halpha luminosity predicted by population synthesis models is larger than the
observed one, especially for low-mass systems (M < 10^4 M_sun). Such a
difference is reduced, but not erased, when the incomplete sampling of the
initial mass function (IMF) at the high-mass end is taken into account. Our
results suggest that a non-negligible fraction of UV ionising and non-ionising
radiation is leaking into the ISM outside the HII regions. This would be in
agreement with the large UV and Halpha diffuse fractions observed in M33, but
it implies that stellar systems younger than 3 Myr retain, on average, only 30%
of their Lyman continuum photons. However, the uncertainties on cluster ages
and the stochastic fluctuations of the IMF do not allow to accurately quantify
this issue. We also consider the possibility that this discrepancy is the
consequence of a suppressed or delayed formation of the most massive stars.Comment: 17 pages, 13 figures. Accepted for publications in A&A; v2 --> Table
2 corrected because of a misprint in the FUV magnitude
Earthquake Characteristics and Structural Properties of the Southern Tyrrhenian Basin from Full Seismic Wave Simulations
Modelling the response of seismic wavefields to sharp lateral variations in crustal discontinuities is essential for seismic tomography application and path effects correction in earthquake source characterization. This is particularly relevant when wavefields cross back-arc oceanic basins, i.e. mixed continental-oceanic settings. High-frequency (> 0.05 Hz) seismic waves resonate and get absorbed across these settings due to a shallow Moho, crustal heterogeneities, and energy leakage. Here, we provide the first high-frequency wave-equation model of full seismograms propagating through realistic 3D back-arc basins. Inversion by parameters trial based on correlation analyses identifies P-, S-and coda-wave as attributes able to estimate jointly 3D Moho variations, sediment thickness, and earthquake source characteristics using data from a single regional earthquake. We use as data waveforms produced by the Accumoli earthquake (Central Italy, 2016), propagating across the Southern Tyrrhenian basin and recorded across Southern Italy. The best model comprises a deep Moho ( similar to 18 km) in the middle of the basin and a crustal pinch with the continental crust in Sicily. The deep Moho corresponds to the Issel Bridge, a portion of continental crust trapped between the Vavilov and Marsili volcanic centres. The Accumoli earthquake is optimally described at a depth of 7.3 km using a boxcar with rise time of 6 s. Our results show that the early S-wave coda comprises trapped and reverberating phases sensitive to crustal interfaces. Forward modelling these waves is computationally expensive; however, adding these attributes to tomographic procedures allows modelling both source and structural parameters across oceanic basins
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