58 research outputs found

    Olive phenology as a sensitive indicator of future climatic warming in the Mediterranean

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    Experimental and modelling work suggests a strong dependence of olive flowering date on spring temperatures. Since airborne pollen concentrations reflect the flowering phenology of olive populations within a radius of 50 km, they may be a sensitive regional indicator of climatic warming. We assessed this potential sensitivity with phenology models fitted to flowering dates inferred from maximum airborne pollen data. Of four models tested, a thermal time model gave the best fit for Montpellier, France, and was the most effective at the regional scale, providing reasonable predictions for 10 sites in the western Mediterranean. This model was forced with replicated future temperature simulations for the western Mediterranean from a coupled ocean-atmosphere general circulation model (GCM). The GCM temperatures rose by 4·5 °C between 1990 and 2099 with a 1% per year increase in greenhouse gases, and modelled flowering date advanced at a rate of 6·2 d per °C. The results indicated that this long-term regional trend in phenology might be statistically significant as early as 2030, but with marked spatial variation in magnitude, with the calculated flowering date between the 1990s and 2030s advancing by 3–23 d. Future monitoring of airborne olive pollen may therefore provide an early biological indicator of climatic warming in the Mediterranean

    Spatial and Temporal Variations in the Annual Pollen Index Recorded by Sites Belonging to the Portuguese Aerobiology Network

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    This study presents the findings of a 10-year survey carried out by the Portuguese Aerobiology Network (RPA) at seven pollen-monitoring stations: five mainland stations (Oporto, Coimbra, Lisbon, Évora and Portimão) and two insular stations [Funchal (Madeira archipelago) and Ponta Delgada (Azores archipelago)]. The main aim of the study was to examine spatial and temporal variations in the Annual Pollen Index (API) with particular focus on the most frequently recorded pollen types. Pollen monitoring (2003–2012) was carried out using Hirst-type volumetric spore traps, following the minimum recommendations proposed by the European Aerobiology Society Working Group on Quality Control. Daily pollen data were examined for similarities using the Kruskal–Wallis nonparametric test and multivariate regression trees. Simple linear regression analysis was used to describe trends in API. The airborne pollen spectrum at RPA stations is dominated by important allergenic pollen types such as Poaceae, Olea and Urticaceae. Statistically significant differences were witnessed in the API recorded at the seven stations. Mean API is higher in the southern mainland cities, e.g. Évora, Lisbon and Portimão, and lower in insular and littoral cities. There were also a number of significant trends in API during the 10-year study. This report identifies spatial and temporal variations in the amount of airborne pollen recorded annually in the Portuguese territory. There were also a number of significant changes in API, but no general increases in the amount of airborne pollen

    Threat of allergenic airborne grass pollen in Szczecin, NW Poland: the dynamics of pollen seasons, effect of meteorological variables and air pollution

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    The dynamics of Poaceae pollen season, in particularly that of the Secale genus, in Szczecin (western Poland) 2004–2008 was analysed to establish a relationship between the meteorological variables, air pollution and the pollen count of the taxa studied. Consecutive phases during the pollen season were defined for each taxon (1, 2.5, 5, 25, 50, 75, 95, 97.5, 99% of annual total), and duration of the season was determined using the 98% method. On the basis of this analysis, the temporary differences in the dynamics of the seasons were most evident for Secale in 2005 and 2006 with the longest main pollen season (90% total pollen). The pollen season of Poaceae started the earliest in 2007, when thermal conditions were the most favourable. Correlation analysis with meteorological factors demonstrated that the relative humidity, mean and maximum air temperature, and rainfall were the factors influencing the average daily pollen concentrations in the atmosphere; also, the presence of air pollutants such as ozone, PM10 and SO2 was statistically related to the pollen count in the air. However, multiple regression models explained little part of the total variance. Atmospheric pollution induces aggravation of symptoms of grass pollen allergy

    Hypersensitivity to Pollen of Olea Europea in Patients with Pollen Allergy in Zadar Country, Croatia

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    Preosjetljivost na pelud masline važan je uzrok peludnih alergija u mediteranskim zemljama. Cilj ovoga rada bio je utvrditi učestalost preosjetljivosti na pelud masline među bolesnicima s peludnom alergijom u Zadru i Zadarskoj županiji. Dobivene rezultate usporedili smo s ranijim ispitivanjem preosjetljivosti na pelud masline u Dalmaciji. Ukupno je obrađen 671 ispitanik s preosjetljivosti na peludne alergene. Od toga broja 61 % ispitanika bilo je muškog spola, a 39 % je bilo ženskog spola. Od ukupno ispitanih 53.5 % činila su djeca u dobi od 4 do 14 godina, a preostalih 46.5 % bili su odrasli u dobi od 15 do 59 godina života. Svim ispitanicima uzeta je detaljna obiteljska i osobna anamneza, napravljen klinički pregled te učinjeno kožno prick-testiranje i enzimatsko-imunološki UniCAP-test za određivanje specifi čnih IgE-protutijela. Statistička obrada podataka učinjena je χ2-testom. Preosjetljivost na pelud masline dokazana je u 8.8 % bolesnika s peludnom alergijom. Najveći broj bolesnika s preosjetljivosti na pelud masline boluje od alergijskog rinitisa, 58 % bolesnika. Postoji statistički značajna razlika u broju bolesnika između dvije ispitivane sredine, gradske i seoske. Samo 3 % bolesnika stanovnici su otoka. Preosjetljivost na pelud masline u našem ispitivanju najniža je u odnosu na ispitivanja provedena u drugim mediteranskim zemljama. Najčešće se očituje kliničkom slikom alergijskog rinitisa, a statistički je značajno češća u gradskoj sredini. Usporedba preosjetljivosti na pelud masline tijekom dvaju ispitivanih razdoblja u našoj zemlji nije pokazala porast broja bolesnika s preosjetljivosti na pelud masline.Olive pollen is one of the most common respiratory allergens in the Mediterranean countries. The aim of this study was to establish the frequency of hypersensitivity to the pollen of Olea europea in pollen allergic patients in the County of Zadar. The study included 671 patients with pollen allergy; 61 % were male and 39 % female. 53.5 % were children aged from 4 to 14 years and 46.5 % adolescents and adults from 15 to 59 years. We took their case history, clinically examined them, and tested using the skin prick test and enzymo-immunologic UniCAP test for specifi c IgE antibodies. For statistical analysis we used the chi-square test. Hypersensitivity to Olea europea pollen was confi rmed in 8.8 % patients with pollen allergy. Among them, the most prevalent symptom was rhinitis (58 %). Most hypersensitive patients were urban residents. Only 3 % patients lived on an island. Judging by available data, our fi ndings show the lowest hypersensitivity to olive pollen in the Mediterranean. A comparison with our two earlier studies did not show any fl uctuation in this kind of hypersensitivity

    Enhanced current flow through a plasma cloud by induction of plasma turbulence

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