Mobile slit sampler for pollen and spore sampling on motorways

Summary Pollen allergic patients often develop severe symptoms during or after driving on English motorways, suggesting very high counts due to turbulence from vehicles disturbing the wayside grass which is usually allowed to pollenate. To investigate this hypothesis the author made a slit sampler which is mounted on the vehicle, and indicates directly in litres the amount of air sampled on to a vaseline coated slide. Grass pollen counts as high as 10,000/m³ have been found at the seasonal peak, and high concentrations of spores and pollution from particles of carbon from vehicle exhausts have been observed. The device can take serial samples and may prove useful in the study of the epidemiology of plant pathogens or air pollution with particulate matter.     

One-Year pollen and spore calendars of Saudi Arabia Al-Khobar, Abha and Hofuf

Airborne Pollen grains and Spores of three different cities viz., Al-Khobar (1987–1988), Abha (1991–1992) and Hofuf (1992–1993) in Saudi Arabia were studied using Burkard Volumetric Seven-Day Spore Trap. The data were analyzed in relation to their allergenic capability and one-year pollen and spore calendars were designed to correlate the patients’ symptoms as well as for selection of appropriate allergen extracts for diagnosis and treatment of allergic diseases. Amongst pollen group, Amaranthus viridis, Plantago spp., Chenopodium album, Ricinus communis, Rumex vesicarius, Juniperus spp., Parkinsonia aculeata, Prosopis spp., and Phoenix dactylifera were some of the frequent types. Amongst the fungal spores group Cladosporium, Smuts spores, Colored basidiospores, Alternaria, Ulocladium and Drechslera were the dominant types.     

Assembling spatially explicit landscape models of pollen and spore dispersal by wind for risk assessment

Models of windblown pollen or spore movement are required to predict gene flow from genetically modified (GM) crops and the spread of fungal diseases. We suggest a simple form for a function describing the distance moved by a pollen grain or fungal spore, for use in generic models of dispersal. The function has power-law behaviour over sub-continental distances. We show that air-borne dispersal of rapeseed pollen in two experiments was inconsistent with an exponential model, but was fitted by power-law models, implying a large contribution from distant fields to the catches observed. After allowance for this 'background' by applying Fourier transforms to deconvolve the mixture of distant and local sources, the data were best fit by power-laws with exponents between 1.5 and 2. We also demonstrate that for a simple model of area sources, the median dispersal distance is a function of field radius and that measurement from the source edge can be misleading. Using an inverse-square dispersal distribution deduced from the experimental data and the distribution of rapeseed fields deduced by remote sensing, we successfully predict observed rapeseed pollen density in the city centres of Derby and Leicester (UK).     

An evaluation of the microscopical counting methods of the tape in hirst-burkard pollen and spore trap

Three different sampling units in current use and different sampling strategies were tested. Randomly placed microscope fields are good in estimating the daily mean concentration, but very big sample size is needed. Traverses across the slide in systematic order are best to estimate the shortterm concentrations and diurnal variation. A formula for the estimation of the error in one transverse traverse is given. Twelve transverse traverses in systematic order is also enough to estimate the daily mean concentration. One or two traverses along the length of the slide give often unreliable estimates because of the irregularities in the transverse variation of the particle concentrations on the slide. For the same reason it is not safe to choose an “effectively collecting area”. Instead the whole width of the tape should be studied.     

Gamma,Gaussian and logistic distribution models for airborne pollen grains and fungal spore season dynamics

The characteristics of a pollen season, such as timing and magnitude, depend on a number of factors such as the biology of the plant and environmental conditions. The main aim of this study was to develop mathematical models that explain dynamics in atmospheric concentrations of pollen and fungal spores recorded in Rzeszów (SE Poland) in 2000–2002. Plant taxa with different characteristics in the timing, duration and curve of their pollen seasons, as well as several fungal taxa were selected for this analysis. Gaussian, gamma and logistic distribution models were examined, and their effectiveness in describing the occurrence of airborne pollen and fungal spores was compared. The Gaussian and differential logistic models were very good at describing pollen seasons with just one peak. These are typically for pollen types with just one dominant species in the flora and when the weather, in particular temperature, is stable during the pollination period. Based on s parameter of the Gaussian function, the dates of the main pollen season can be defined. In spite of the fact that seasonal curves are often characterised by positive skewness, the model based on the gamma distribution proved not to be very effective.     

Substructure of spore and pollen grain exines in Lycopodium,Alnus, Betula,Fagus and Rhododendron

We have used atomic force microscopy and scanning tunnelling microscopy to extract new information about the substructure of the Alnus, Betula, Fagus, Lycopodium and Rhododendron pollen grain exine. Our scans of exines using atomic force microscopy and scanning tunnelling microscopy reveal somewhat similar substructures for Lycopodium spores and pollen of Alnus, Betula, Fagus and Rhododendron. They show various levels of alignment and clustering of substructure components. Except for Alnus, which showed polygonal clustering of spheroids and weak alignment, there is pronounced alignment of helical units. In Betula, Fagus, Lycopodium and Rhododendron the subunits appear to be helical or perhaps consisting of elongated spheroids, these spheroids are however arranged in a way that suggest that they are part of a helical structure. The diameter of these helical subunits range from 10–15 nm in Fagus, 20–25 nm in Lycopodium, 35–90 nm in Rhododendron up to 70–120 nm in Betula. Our preparations graded from intact or fractured fresh pollen to pollen that was acetolyzed, chemically fixed and epoxy resin embedded. While our knowledge of the exact radial/lateral orientation of most of our scans is less than perfect there were in all cases substructures or cross connections of exine units. We found results from scanning and transmission electron microscopy to be helpful in understanding images from Atomic Force- and Scanning Tunnelling Microscopy.     

Diagnostics in allergic diseases by correlating pollen/fungal spore counts with patient scores of symptoms

Pollen/fungal spore counts have been performed since 1977 in Copenhagen and since 1979 in Copenhagen, Viborg, Nykobing Falster and Nykobing Mors. Four Burkard Seven Day Recording Volumetric Spore Traps were used. Fungal spore counts were performed in the same period using a BIAP Slit Sampler (placed in the Copenhagen area). The study was carried out by the Danish Asthma-Allergy Association's interdisciplinary Aerobiology Group. In 1979 at the Allergy Clinic, Copenhagen County Hospital at Lyngby, data from the pollen/fungal spore counts were compared with daily scores of 95 patients' symptoms and medicine-index. Seventy-eight patients were scored in the entire period where symptoms occurred. For diagnostic purposes of allergy to pollen and fungal spores, previous patient history and symptom scores correlated to the pollen/fungal spore counts showed similarity and to some extent supplementary corrections to the diagnosis based on previous patient history, skin tests, laboratory tests, and provocation tests.     

Atmospheric pollen and fungal spores in Hamilton in 1972 estimated by the Hirst automatic volumetric spore trap

A knowledge of the atmospheric pollen and fungal spores is necessary for the diagnosis and management of extrinsic rhinitis and asthma. The Hirst automatic volumetric spore trap has been used for the first time in Canada to identify the quantitative and seasonal incidence of these particles. The trap is easy to operate and has several advantages over the previously used gravity samplers. Tree, grass and ragweed pollens occurred in short, well-defined seasons. Fungal spores greatly outnumbered pollen by 120 to one, and occurred in long, ill-defined seasons. They included large numbers of small basidiospores and ascospores which have previously not been detected in Canada. The latter have not been considered as potential allergens; their clinical importance requires investigation.     

Optimizing Bacillus subtilis spore isolation and quantifying spore harvest purity

Investigating the biochemistry, resilience and environmental interactions of bacterial endospores often requires a pure endospore biomass free of vegetative cells. Numerous endospore isolation methods, however, neglect to quantify the purity of the final endospore biomass. To ensure low vegetative cell contamination we developed a quality control technique that enables rapid quantification of endospore harvest purity. This method quantifies spore purity using bright-field and fluorescence microscopy imaging in conjunction with automated cell counting software. We applied this method to Bacillus subtilis endospore harvests isolated using a two-phase separation method that utilizes mild chemicals. The average spore purity of twenty-two harvests was 88 ± 11% (error is 1σ) with a median value of 93%. A spearman coefficient of 0.97 correlating automated and manual bacterial counts confirms the accuracy of software generated data.     

Optimizing Bacillus subtilis spore isolation and quantifying spore harvest purity

Investigating the biochemistry, resilience and environmental interactions of bacterial endospores often requires a pure endospore biomass free of vegetative cells. Numerous endospore isolation methods, however, neglect to quantify the purity of the final endospore biomass. To ensure low vegetative cell contamination we developed a quality control technique that enables rapid quantification of endospore harvest purity. This method quantifies spore purity using bright-field and fluorescence microscopy imaging in conjunction with automated cell counting software. We applied this method to Bacillus subtilis endospore harvests isolated using a two-phase separation method that utilizes mild chemicals. The average spore purity of twenty-two harvests was 88 ± 11% (error is 1σ) with a median value of 93%. A spearman coefficient of 0.97 correlating automated and manual bacterial counts confirms the accuracy of software generated data.     

Correlation between spore structure and spore properties in Bacillus megaterium

The spores of six strains of Bacillus megaterium were divided into two distinct groups on the basis of germination. Three of the strains germinated in a mixture of l-alanine and inosine (AL type spores), and three strains germinated in a mixture of glucose and potassium nitrate (GN type spores); recriprocal germination in the respective solutions did not occur. The AL spores and the GN spores were morphologically distinct. Other differences between the two spore groups included germination inhibition characteristics, dipicolinic acid content, hexosamine content, phosphorus and magnesium content, spore coat features, ion exchange properties, and heat resistance. A correlation appears to exist between spore morphology and certain other spore properties in strains of B. megaterium.     

Fern and bryophyte endozoochory by slugs

Endozoochory plays a prominent role for the dispersal of seed plants, and dispersal vectors are well known. However, for taxa such as ferns and bryophytes, endozoochory has only been suggested anecdotally but never tested in controlled experiments. We fed fertile leaflets of three ferns and capsules of four bryophyte species to three slug species. We found that, overall, spores germinated from slug feces in 57.3 % of all 89 fern and in 51.3 % of all 117 bryophyte samples, showing that the spores survived gut passage of slugs. Moreover, the number of samples within which spores successfully germinated did not differ among plant species but varied strongly among slug species. This opens new ecological perspectives suggesting that fern and bryophyte endozoochory by gastropods is a so-far-overlooked mode of dispersal, which might increase local population sizes of these taxa by spore deposition on suitable substrates.