Methods for interpolating missing data in aerobiological databases.

Missing data is a common problem in scientific research. The availability of extensive environmental time series is usually laborious and difficult, and sometimes unexpected failures are not detected until samples are processed. Consequently, environmental databases frequently have some gaps with missing data in it. Applying an interpolation method before starting the data analysis can be a good solution in order to complete this missing information. Nevertheless, there are several different approaches whose accuracy should be considered and compared. In this study, data from 6 aerobiological sampling stations were used as an example of environmental data series to assess the accuracy of different interpolation methods. For that, observed daily pollen/spore concentration data series were randomly removed, interpolated by using different methods and then, compared with the observed data to measure the errors produced. Different periods, gap sizes, interpolation methods and bioaerosols were considered in order to check their influence in the interpolation accuracy. The moving mean interpolation method obtained the highest success rate as average. By using this method, a success rate of the 70% was obtained when the risk classes used in the alert systems of the pollen information platforms were taken into account. In general, errors were mostly greater when there were high oscillations in the concentrations of biotic particles during consecutive days. That is the reason why the pre-peak and peak periods showed the highest interpolation errors. The errors were also higher when gaps longer than 5 days were considered. So, for completing long periods of missing data, it would be advisable to test other methodological approaches. A new Variation Index based on the behaviour of the pollen/spore season (measurement of the variability of the concentrations every 2 consecutive days) was elaborated, which allows to estimate the potential error before the interpolation is applied.

Increasing resolution of airborne pollen forecasting at a discrete sampled area in the southwest Mediterranean Basin.

Daily fluctuations of the airborne pollen concentrations produce variations on symptomatology in allergic population. Such fluctuations are influenced by local vegetal coverage, flowering phenology, geography and climatology. Since 1991, airborne pollen of Malaga province (southern Spain) has been monitored in 7 different locations. Malaga station has been kept operational uninterruptedly throughout the studied period, while the rest of the stations only worked in periods of 2-4 years. Weekly, its pollen information is updated online to inform the population in order to prevent allergic diseases. Increasing the spatial resolution of pollen information would be very useful for allergic population living at unsampled locations. Due to the impossibility of keeping operational a high number of pollen stations covering the whole province of Malaga, the aim of this study is to create spatial models to extrapolate and forecast the pollen concentrations to Malaga province by using the concentrations registered at the capital as unique input. To do so, the relationships obtained between the airborne pollen concentrations detected at Malaga city and those detected at the other stations have been used to elaborate models for the main pollen types registered at the province. These models were spatially interpolated all over the province by using co-kriging techniques and the Compensated Thermicity Index as covariable. As result of this work, pollen distribution of the 8 most prevalent taxa has been depicted all over the whole Malaga province and an allergy alert system has been set up to extrapolate pollen information from Malaga to the whole province.

Identification and quantification of isoquinoline alkaloids in the genus Sarcocapnos by GC-MS.

Six cularine alkaloids, cularicine, O-methylcularicine, celtisine, cularidine, cularine and celtine, three isocularine alkaloids, sarcophylline, sarcocapnine and sarcocapnidine, and five non-cularine alkaloids, glaucine, protopine, ribasine, dihydrosanguinarine and chelidonine, were identified and quantified by GC-MS in nine taxa of the genus Sarcocapnos (Fumariaceae). The chemotaxonomic significance of the results is discussed.

Direct determination of alkaloid contents in Fumaria species by GC-MS.

The isoquinoline alkaloids protopine, cryptopine, sinactine, stylopine, bicuculline, adlumine, parfumine, fumariline, fumarophycine, fumaritine, dihydrofumariline, parfumidine and dihydrosanguinarine have been determined and identified by gas chromatography-mass spectrometry in Fumaria agraria, F. bastardii, F. capreolata, F. sepium, F. densiflora, F. faurei, F. officinalis subsp. officinalis, F. parviflora, F. petteri subsp. calcarata and F. macrosepala. The chemotaxonomic significance of the results is discussed.

Pollinosis due to Australian pine (Casuarina): an aerobiologic and clinical study in southern Spain.

An aerobiologic and clinical survey was conducted in Málaga, southern Spain, in order to determine fluctuations of Australian pine (Casuarina) pollen in the atmosphere of the city, and the prevalence of sensitivity in a nonatopic population. The aerobiologic survey, using a Burkard spore trap, was conducted from January 1991 to December 1994, and sensitization was ascertained by the skin prick test. The pollen season is relatively short and the pollen dispersion period occurs during October and November, mainly during the last 3 weeks of October. Diurnal patterns showed that the highest concentrations of pollen occur between 12 a.m. and 2 p.m., the most influential variables in its dispersion being temperature, sunshine, and rainfall. The prevalence of sensitization to Casuarina pollen was determined by skin prick test (SPT) in a nonatopic population of 210 patients with a previous history of autumn rhinitis, asthma, or rhinitis asthma. Six subjects showed a positive reaction to the pollen extracts, and the presence of specific IgE was demonstrated by the conventional radioallergosorbent test (RAST > or = 2) in five of these patients with positive SPT.