22 research outputs found
The fundamental group and torsion group of Beauville surfaces
We give a survey on the fundamental group of surfaces isogenous to a higher
product. If the surfaces are regular, e.g. if they are Beauville surfaces, the
first homology group is a finite group. We present a MAGMA script which
calculates the first homology groups of regular surfaces isogenous to a
product.Comment: 14 pages; MAGMA script included; v2: minor corrections, final version
to appear in the Proceedings of the Conference "Beauville Surfaces and
Groups", Newcastle University (UK), 7-9th June 201
Nanolipid-trehalose conjugates and nano-assemblies as putative autophagy inducers
The disaccharide trehalose is an autophagy inducer, but its pharmacological application is severely limited by its poor pharmacokinetics properties. Thus, trehalose was coupled via suitable spacers with squalene (in 1:2 and 1:1 stoichiometry) and with betulinic acid (1:2 stoichiometry), in order to yield the corresponding nanolipid-trehalose conjugates 1-Sq-mono, 2-Sq-bis and 3-Be-mono. The conjugates were assembled to produce the corresponding nano-assemblies (NAs) Sq-NA1, Sq-NA2 and Be-NA3. The synthetic and assembly protocols are described in detail. The resulting NAs were characterized in terms of loading and structure, and tested in vitro for their capability to induce autophagy. Our results are presented and thoroughly commented upon
Construction of maps for soil recycling in regional infrastructural works integrating soil-quality laws
A soil-quality map is at present an important tool to integrate laws on soil quality with regional infrastructural works. Basic data are commonly available, but soil quality is an indicator that has to be derived from these data, including site-specific environmental standards.We propose three geostatistics-based methods for the comparison of interpolated contaminant concentrations and standards. The study is illustrated by data from a part of the Betuwe railroad transect, which extends over 12 km in the western Netherlands. As it turns out, a useful procedure is to combine interpolated contaminant concentrations with interpolated threshold values
Construction of maps for soil recycling in regional infrastructural works integrating soil-quality laws
A soil-quality map is at present an important tool to integrate laws on soil quality with regional infrastructural works. Basic data are commonly available, but soil quality is an indicator that has to be derived from these data, including site-specific environmental standards.We propose three geostatistics-based methods for the comparison of interpolated contaminant concentrations and standards. The study is illustrated by data from a part of the Betuwe railroad transect, which extends over 12 km in the western Netherlands. As it turns out, a useful procedure is to combine interpolated contaminant concentrations with interpolated threshold values
Statistical analysis of anthropogenic versus geochemical-controlled differences in groundwater composition in The Netherlands
Quantitative insight into the impact of land use on groundwater composition is vital for the sustainable management of aquifers, especially those situated in urban areas. The objective of the present study was to determine the effects of land use on groundwater composition throughout the Netherlands, relative to the influence of groundwater age, groundwater origin, and geochemical processes. Using a nationwide dataset on shallow groundwater from the Dutch National Groundwater-Monitoring Network, land-use effects were quantified statistically for all major ionic substances. Analysis of variance was applied to the entire dataset, to a priori groups based on groundwater age, and to non-a priori statistical clusters determined by fuzzy c-means clustering. The results indicated that the effect of land use on groundwater composition in the Netherlands strongly depends on geochemical processes and groundwater age. Land-use effects were most pronounced in younger, geochemically less-evolved groundwater: for example, urban areas showed an increase in Ca, Na, Cl, and HCO3 by a factor 2-4, an increase in K and B by a factor 4-10, and a decrease in Al by a factor 10 compared to natural areas. Similarly, agricultural areas showed an increase in Ca, NO3, and Fe by a factor 2-4, an increase in K by a factor 4-10, and a decrease in Al by a factor 2. Compared to urban areas, agricultural areas contained less Na, Cl, and Al and more NO3. Our results demonstrate that the importance of the processes controlling groundwater composition in the Netherlands is scale-dependent, with geochemical processes being more dominant on a national scale and land use on regional and local scales. © 2007 Elsevier B.V. All rights reserved
Association between PM10 concentrations and school absences in proximity of a cement plant in northern Italy.
Dusts are one of the main air pollutants emitted during cement manufacturing. A substantial part of these are breathable particles that are less than 10\u3bcm in diameter (PM10), which represent a potential threat for the health of the exposed population. This study aimed at evaluating the short-term effects of PM10 concentrations on the health of children, aged 6-14 years, who attended the schools in Fumane (Italy), in proximity (1.2km) to a large cement plant. School absenteeism was used as a proxy indicator of child morbidity. Time series of daily school absences and PM10 concentrations were collected for 3 school-years from 2007 to 2010 (541 school-days, 462 children on average). The associations between PM10 concentrations and school absence rates in the same day (lag0) and in the following 4 days (lag1 to lag4) were evaluated using generalised additive models, smoothed for medium/long term trends and adjusted for day of the week, influenza outbreaks, daily temperature and rain precipitations. The average concentration of PM10 in the period was 34 (range: 4-183) \u3bcg/m(3). An average 10\u3bcg/m(3) increase of PM10 concentration in the previous days (lag0-4) was associated with a statistically significant 2.5\% (95\%CI: 1.1-4.0\%) increase in the rate of school absences. The highest increase in the absence rates (2.4\%; 95\%CI: 1.2-3.5\%) was found 2 days after exposure (lag2). These findings provide epidemiological evidence of the acute health effects of PM10 in areas with annual concentrations that are lower than the legal European Union limit of 40\u3bcg/m(3), and support the need to establish more restrictive legislative standards