Descriptive and spatial epidemiology of bovine cysticercosis in North-Eastern Spain (Catalonia).

From March 2005 to December 2007, 284 animals from 67 cattle farms (24 dairy and 43 beef) affected by bovine cysticercosis were detected in the region of Catalonia (North-Eastern Spain). Dairy farms were almost twice more likely to be affected than beef farms (OR=1.79, 95% CI=1.08-2.96, p<0.05), and infected premises have a statistically significant (p<0.05) larger number of animals when compared to uninfected farms in Catalonia. The geographical distribution of the infected farms was evaluated and two statistically significant clusters were identified. The most likely cluster was located in the western part of the study region, with 8 out of 10 farms infected. Epidemiological investigations revealed that the 8 farms belonged to the same company. The secondary cluster was located in Eastern Catalonia with 12 infected farms out of 167 cattle farms. No epidemiological links were found among the 12 infected premises. A questionnaire, based on the EFSA risk assessment, was used to assess the most likely route of introduction into each affected farm. Water supply for animals was the route with the highest score in 41.8% of the cases

Biomarkers: a strategic tool in the assessment of environmental quality of coastal waters

Ecosystems are under the pressure of complex mixtures of contaminants whose effects are not always simple to assess. Biomarkers, acting as early warning signals of the presence of potentially toxic xenobiotics, are useful tools for assessing either exposure to, or the effects of these compounds providing information about the toxicant bioavailability. In fact, it has been argued that a full understanding of ecotoxicological processes must consider an integrated multi-level approach, in which molecular impact is related with higher-order biological consequences at the individual, population and community levels. Monitoring programs should make use of this tool to link contaminants and ecological responses fulfilling strategies like those launched by OSPAR (Commissions of Oslo and Paris) Convention on the protection of the marine environment of the North-East Atlantic and the International Council for the Exploration of the Sea (ICES). An overview of the work done in the past few years using biomarkers as in situ tools for pollution assessment in Portuguese coastal waters is presented as a contribution to the set up of a biomonitoring program for the Portuguese coastal zone. Considering the data set available the biomonitoring proposal should include the analysis of biomarkers and effects at individual levels. The aim of the program will include a spatial and temporal characterization of the biomarkers acetyl-cholinesterase, metallothioneins, DNA damage, adenylate energy charge and scope-for-growth levels. The investigation of the spatial variation of biomarkers is crucial to define sites for long term monitoring, which will be integrated with a chemical monitoring program. This framework will be a major contribution to the implementation of a national database for the use of biomarkers along the Portuguese coast.info:eu-repo/semantics/publishedVersio

Technical-economical evaluation of pavement recycling alternatives

Pavement recycling is becoming an increasingly important alternative worldwide for maintenance of highways, once sustainability and environmental issues have continued to receive more attention. The reference point is that of considering the use of road materials in a closed cycle, in which a natural material, previously used in road construction, should not be rejected in the following life-cycle. The objective of this paper is that of analysing flexible pavement recycling alternatives techniques, including reclaimed material from flexible pavements recycled with emulsion, cement and reused in a hot-mix. Based on the results obtained from field and laboratory tests (stiffness modulus, resistance to fatigue and permanent deformation), carried out using different materials, a set of numerical simulations were made for the design of pavement structures where those mixtures would be used, according to their characteristics and traffic specifications. The results of pavement design were obtained using the linear elastic theory in the BISAR program. With the results obtained from the pavement design, the cost savings of using recycled materials in the different pavement structures were quantified and compared to a standard option, where new natural aggregates and binders would be used. In this analysis, the consideration of the reduction in the disposal of reclaimed pavement materials was also addressed. The results of this research will support the production of specifications, thus facilitating a more accurate reuse of natural resources, assisting in the protection of the environment, as well as in a more effective use of financial resources available for the activity of pavement maintenance and rehabilitation

Foot-and-mouth disease in Tanzania from 2001 to 2006.

Foot-and-mouth disease (FMD) is endemic in Tanzania, with outbreaks occurring almost each year in different parts of the country. There is now a strong political desire to control animal diseases as part of national poverty alleviation strategies. However, FMD control requires improving the current knowledge on the disease dynamics and factors related to FMD occurrence so control measures can be implemented more efficiently. The objectives of this study were to describe the FMD dynamics in Tanzania from 2001 to 2006 and investigate the spatiotemporal patterns of transmission. Extraction maps, the space-time K-function and space-time permutation models based on scan statistics were calculated for each year to evaluate the spatial distribution, the spatiotemporal interaction and the spatiotemporal clustering of FMD-affected villages. From 2001 to 2006, 878 FMD outbreaks were reported in 605 different villages of 5815 populated places included in the database. The spatial distribution of FMD outbreaks was concentrated along the Tanzania-Kenya, Tanzania-Zambia borders, and the Kagera basin bordering Uganda, Rwanda and Tanzania. The spatiotemporal interaction among FMD-affected villages was statistically significant (P≤0.01) and 12 local spatiotemporal clusters were detected; however, the extent and intensity varied across the study period. Dividing the country in zones according to their epidemiological status will allow improving the control of FMD and delimiting potential FMD-free areas

Mechanical behaviour of two crushed materials used in portuguese UGL

The crushed materials of extensive granulometry (UGM) are often used as unbound granular layers of road pavements, namely as granular sub-base and base. The behaviour of these materials on pavement layers is not sufficiently characterized, in spite of several studies already performed on this matter, due to reasons connected to the heterogeneity of the rock masses from which they come from. This has special importance for the Portuguese pavement technology. In the attempt of contributing for a better knowledge of that behaviour, a work was developed with the objective of obtaining the mechanical characterization and the establishment of behaviour models for crushed materials coming from different lithologies, namely limestone and granite, susceptible of being used as UGM. This paper describes the principal results obtained from this work and points out the main directives that can be extracted from it, in terms of the global behaviour of a road pavement

The influence of construction quality control data variability on pavements evolution

Predicting pavement evolution is a fundamental component in pavement maintenance and rehabilitation management work. However, it is very complex to carry out due to several drawbacks, namely a common use of inadequate quality control procedures or a lack of reproducibility of quality control data. This paper describes the main conclusions of a study on the influence of construction quality control data on pavement evolution. It was possible to develop a methodology for this purpose based on stiffness modulus evolution, which will also allow for the assessment of the pavement’s design. The study involved the establishment of a statistical analysis procedure in order to analyse construction quality variability data, and the use of deflection tests, stiffness modulus tests, back-analysis of FWD data and the development of a procedure to correct the effect of temperature within the pavement on stiffness modulus. Results analysis showed that control quality data variability has an important influence on pavements’ evolution prediction. It is expected that the integration of the proposed methodology on quality control plans will improve the data accuracy and all the decisions based on it.(undefined

Traffic noise changes due to water on porous and dense asphalt surfaces

The standards for the environmental quality required by the European Community are very demanding in what concerns traffic noise. The interaction tire/road is undoubtedly one of the main sources of traffic noise. Nevertheless, standards do not account for the increase in the noise level caused by rain falling onto road surfaces. Therefore, the aim of this work is to study the effects of water on pass-by noise since the weather is rainy about 25 per cent of the year in Portugal. Thus, it addresses two currently used pavement surfaces, porous asphalt and dense asphalt, constructed in a motorway. A version of the Statistical Pass-By Method was used to assess noise levels with dry and wet surfaces, using a selected set of heavy and light vehicles. The results include analysis of the statistical pass-by index, pressure noise levels and noise spectrum. Noise levels increase significantly with the presence of water, shifting the overall noise by 4 dB(A). The benefits of porous asphalt are null for heavy vehicles, particularly at high speeds. CE Database subject headings: traffic noise, water, porous asphalt, dense asphalt, statistical pass-by method, noise level, noise spectrum.(undefined

Construction quality, temperature and rutting effect on top-down cracking initiation

Top-down cracking (TDC) is a flexible pavement distress caused by a number of factors, including high contact stresses from truck tires, mix design characteristics, (e.g., binder type and aggregate gradation) and poor construction quality, (e.g., segregation and compaction methods). This paper presents the findings of a study seeking to quantify the effect of these factors on TDC. It consists of a laboratory component involving an accelerated Wheel Tracking device and a modeling component involving a 3-D non-linear viscoelastic finite element model. The laboratory component of the study involved 17 asphalt bituminous slabs, constructed to simulate the variation in material properties observed in the field as part of an earlier forensic TDC study. The effect of air voids, bitumen content and type, aggregate gradation and segregation on TDC were studied under 3 temperature conditions. Air voids, segregation and binder content were found to have a significant effect on TDC for all the temperatures tested. Modeling the TDC involved laboratory testing to establish the viscoelastic and tensile strength properties of the asphalt mixtures tested. It was found that the rutted surface contributes significantly to TDC initiation

Benefits of including hot mix recycled materials in pavement design

Pavement recycling is becoming more acceptable among the available techniques for pavement maintenance/rehabilitation. It is based on sustainable development, by reusing materials reclaimed from the pavements and reducing the disposal of asphalt materials. Based on the results obtained from laboratory tests carried out on two bituminous mixtures, one of which including 50% of recycled asphalt, some simulations were made for the design of a pavement where those mixtures would be used as a bituminous base. The aim of this investigation was to assess the benefits of using recycled materials, taking into account environmental and economical advantages. The results of pavement design were obtained using the linear elastic theory in BISAR (the structural analysis software developed by Shell). Fundamental properties of the mixtures analysed in this study were obtained from laboratory tests, which were carried out to determine their stiffness modulus and their resistance to fatigue and permanent deformation. With the results obtained from the pavement design, the cost savings of using recycled materials were quantified

The influence of temperature variation in the prediction of the pavement overlay life

This paper describes a study of the influence of temperature variation in the pavement overlay life, using finite-element methodology to consider the most predominant type of overlay distress observed in the field: reflective cracking. The temperature variation has a significant influence on thermally induced stresses that, in turn, affects the overlay predictive service life. This paper presents a three-dimensional (3D) finite element analysis to predict the pavement overlay life considering a combination of thermal pavement conditions with traffic loads in a pavement overlay modelled on a cracked pavement. The results present the influence of temperature variation in the cracked layer and overlay, as function of the initial pavement temperature. Furthermore, a comparison between the overlay life due to traffic loading and temperature variation in the overlay life is also presented. Finally, the overlay life was predicted using asphalt rubber and conventional mix fatigue laws allowing to conclude that asphalt rubber mixes exhibit more pavement life compared to conventional mixes even when the effects of temperature (temperature variation) are considered in the overlay design