19 research outputs found
The effects of meteorological factors on the occurrence of Ganoderma sp. spores in the air
Ganoderma sp. is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the risk for allergic individuals, we analysed fungal spore circulation in Szczecin, Poland, and its dependence on meteorological conditions. Statistical models for the airborne spore concentrations of Ganoderma sp.—one of the most abundant fungal taxa in the area—were developed. Aerobiological sampling was conducted over 2004–2008 using a volumetric Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation, maximum and average wind speed, relative humidity and maximum, minimum, average and dew point temperatures. These data were used as the explaining variables. Due to the non-linearity and non-normality of the data set, the applied modelling techniques were artificial neural networks (ANN) and mutlivariate regression trees (MRT). The obtained classification and MRT models predicted threshold conditions above which Ganoderma sp. appeared in the air. It turned out that dew point temperature was the main factor influencing the presence or absence of Ganoderma sp. spores. Further analysis of spore seasons revealed that the airborne fungal spore concentration depended only slightly on meteorological factors
Spatial and Temporal Variations in the Annual Pollen Index Recorded by Sites Belonging to the Portuguese Aerobiology Network
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
X- and Q-band EPR study on dosimetric biomaterials
Electron paramagnetic resonance (EPR) spectroscopy (X- and Q-band) was used for identification of stable radicals in: compact bone powder, shell of arcidae mollusc and crystalline alanine. The aim of our investigation was to analyze the complex EPR spectra of these materials and to identify paramagnetic species contributing to it. The most successful results were obtained in the EPR study (X- and Q-band) on deproteinized and irradiated bone powder and arcidae shell at room temperature
Multifrequency EPR study on radiation induced centers in calcium carbonates labeled with 13C
In calcite and aragonite, γ-irradiated at 77 K, several paramagnetic centers were generated and detected
by EPR spectroscopy; in calcite, CO3
– (orthorhombic symmetry, bulk and bonded to surface), CO3
3–, NO3
2–, O3
–,
and in aragonite CO2
– (isotropic and orthorhombic symmetry) depending on the type of calcium carbonate used.
For calcium carbonates enriched with 13C more detailed information about the formed radicals was possible to
be obtained. In both natural (white coral) and synthetic aragonite the same radicals were identifi ed with main
differences in the properties of CO2
– radicals. An application of Q-band EPR allowed to avoid the signals overlap
giving the characteristics of radical anisotropy
EPR study of γ-irradiated feather keratin and human fingernails concerning retrospective dose assessment
In this paper we report the results of comparative EPR studies on free radicals generated in γ-irradiated
powder samples of feather keratin powder and human fingernails. In degassed samples of both materials irradiated at
77 K the major component of EPR spectrum represents sulphur-centred radicals in cysteine residues. It quickly decays
after air admission at room temperature while a singlet assigned to semiquinone melanin radicals remains the only one
seen. The singlet recorded with fingernails decays slowly at room temperature and might be potentially useful for dose
assessment by EPR. The advantages and limitations of fingernails EPR dosimetry are discussed