45 research outputs found

    Allergic diseases in the elderly

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    Demographic distribution of the population is progressively changing with the proportion of elderly persons increasing in most societies. This entails that there is a need to evaluate the impact of common diseases, such as asthma and other allergic conditions, in this age segment. Frailty, comorbidities and polymedication are some of the factors that condition management in geriatric patients. The objective of this review is to highlight the characteristics of allergic diseases in older age groups, from the influence of immunosenescence, to particular clinical implications and management issues, such as drug interactions or age-related side effects

    Comparison of instruments for particle number size distribution measurements in air quality monitoring

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    Number size distributions of airborne particles are relevant to fields including ambient monitoring, pharmaceutical and automotive measurements. A number of commercially available instruments can be used to determine particle number size distributions including the Electrical Low Pressure Impactor (ELPI), Scanning Mobility Particle Sizer (SMPS), Fast Mobility Particle Sizer (FMPS) and the Aerodynamic Particle Sizer (APS). The comparability of the data provided by these instruments has not been fully tested for different kinds of aerosols. This study compared number size distributions of laboratory generated aerosols (TiO2, NaCl, fumed silica and soot) in a wind tunnel. Reasonable agreement was noted between the different instruments, though there were divergences. For example the ELPI was inconsistent at the upper and lower limits of its working size (at low concentrations). Instruments responded variably to different particle types, which has important implications for sampling heterogeneous particle mixtures such as those found in urban air. This study highlights the need for caution when comparing data obtained from different particle instruments, and demonstrates the requirement for further comparison studies in controlled settings using an assortment of particle types with the aim to standardise and harmonise particle sampling protocols.<br/

    Determining the contribution of tyre, clutch, brake and wearing course abrasion to the PM10 emissions of roads

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    Im Hinblick auf die prozessbezogenen BeitrĂ€ge nicht-motorischer Partikelemissionen durch Abriebs- und Aufwirbelung existieren derzeit lediglich Studien, die an stark belasteten Innerortsstraßen oder in Tunneln durchgefĂŒhrt wurden. FĂŒr die Emissionen von Autobahnen konnten die so gewonnenen Ergebnisse daher nicht ohne Weiteres als reprĂ€sentativ fĂŒr die wesentlich hĂ€ufiger anzutreffende Situation frei angeströmter Autobahnabschnitte betrachtet werden. Um diese WissenslĂŒcke zu schließen, wurden im vorliegenden Projekt an der Autobahn A61 fĂŒr mehr als 1 Jahr Luv-Lee Messungen durchgefĂŒhrt. Mittels der NOx-Tracer-Methode wurden die in Tabelle 16 des Berichtes wiedergegebenen partikelmassen-bezogenen Emissionsfaktoren (EFs) ermittelt. Die EFs fĂŒr PM10 sind mit Ergebnissen anderer Studien aus Deutschland beziehungsweise der Schweiz gut vergleichbar, wĂ€hrend sich fĂŒr die PM1-10-Fraktion geringere EFs ergaben, als aktuell angenommen. Mittels der Positiv-Matrix-Faktorisierung konnten neben den motorischen Emissionen vier nicht-motorische Quellfaktoren identifiziert und quantifiziert werden. Dabei zeigte sich neben einem deutlichen Einfluss durch Tausalzausbringung insbesondere die Relevanz von Bremsabrieb Diese Ergebnisse bestĂ€tigen somit auch fĂŒr freiliegende Autobahnabschnitte die Signifikanz der nicht-motorischen Partikelemissionen fĂŒr die PM10-Emissionen.Currently, only studies conducted at highly polluted streets within built-up areas or in tunnels exist concerning non-exhaust emissions from traffic caused by abrasion and resuspension. Results from these studies are therefore not directly transferable to emissions from highway traffic with free airflow. In order to close this gap of knowledge, upwind/downwind measurements at the German highway A61 were conducted for more than 1 year. Particle mass related emissions factors (EFs) (see table 16 of the report) were derived using the NOx tracer method. EFs for PM10 compare well with results from other studies from Germany and Switzerland, whereas the coarse fraction's EFs (PM1-10) are lower than those actually used in Germany. Using positive matrix factorisation (PMF) four non-exhaust sources could be identified and quantified. The relevance of brake abrasion was shown, together with a considerable influence due to road salting. These results confirm the importance of non-exhaust particle emissions regarding PM10 emissions also for highways in non-built-up areas with free air flow conditions

    Public Perception of Invasive Plant Species: Assessing the impact of workshop activities to promote young students’ awareness

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    Invasive species are one of the main threats to biodiversity worldwide. Even though they are identified and recognized as such by the Portuguese law, the majority of the population is not yet aware of this problem. Aiming to increase awareness about biological invasions among young students, a workshop on Invasive Plant Species was organized at the Botanical Museum of the University of Coimbra. A total of 170 teenager students from five schools participated in the workshop. Three activities were prepared, focusing on: (1) identification of invasive plants, (2) competition between native and invasive plants and (3) control of invasive plants. One year later, questionnaires were sent to the participants, aiming to appraise workshop effectiveness, and this questionnaire revealed that these students know more about invasive plant species than a comparable group of students that did not participate in the workshop. The results clearly showed that practical informal education activities may be effective in raising public awareness. Questionnaires were essential to evaluate the knowledge acquired and retained by the students during the workshop.This workshop was supported by FCT-MCTES (Portuguese Foundation for Science and Technology) and European fund FEDER, project INVADER II—Invasion processes, control and restoration of coastal ecosystems invaded by Acacia longifolia—PPCDT/AMB/61387/ 2004

    Performance Evaluation of Workflows Using Continuous Petri Nets with Interval Firing Speeds

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    In this paper, we study performance evaluation of workflow-based information systems. Because of state space explosion, analysis by stochastic models, such as stochastic Petri nets and queuing models, is not suitable for workflow systems in which a large number of flow instances run concurrently. We use fluid-flow approximation technique to overcome this difficulty. In the proposed method, GSPN (Generalized Stochastic Petri Nets) models representing workflows are approximated by a class of timed continuous Petri nets, called routing timed continuous Petri nets (RTCPN). In RTCPN models, each discrete set is approximated by a continuous region on a real-valued vector space, and variance in probability distribution is replaced with a real-valued interval. Next we derive piecewise linear systems from RTCPN models, and use interval methods to compute guaranteed enclosures for state variables. As a case study, we solve an optimal resource assignment problem for a paper review process
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