Science.gov

Sample records for airborne pollen types

  1. Seasonal variations of airborne pollen in Allahabad, India.

    PubMed

    Sahney, Manju; Chaurasia, Swati

    2008-01-01

    Using a Burkard 7-day volumetric sampler a survey of airborne pollen grains in Allahabad was carried out from December 2004--November 2005 to assess the qualitative and quantitative occurrence of pollen grains during different months of the year, and to characterize the pollen seasons of dominant pollen types in the atmosphere of Allahabad. 80 pollen types were identified out of the total pollen catch of 3,416.34 pollen grains/m(3). Bulk of the pollen originated from anemophilous trees and grasses. Thirteen pollen types recorded more than 1 % of the annual total pollen catch. Holoptelea integrifolia formed the major component of the pollen spectrum constituting 46.21 % of the total pollen catch followed by Poaceae, Azadirachta indica, Ailanthus excelsa, Putranjiva roxburghii, Parthenium hysterophorus, Ricinus communis, Brassica compestris, Amaranthaceae/Chenopodiaceae, Madhuca longifolia, Syzygium cumini, other Asteraceae and Aegle marmelos. Highest pollen counts were obtained in the month of March and lowest in July. The pollen types recorded marked the seasonal pattern of occurrence in the atmosphere. February-May was the principal pollen season with maximum number of pollen counts and pollen types. Chief sources of pollen during this period were arboreal taxa. September-October was the second pollen season with grasses being the main source of pollen. Airborne pollen spectrum reflected the vegetation of Allahabad, except for Alnus sp., which grows in the Himalayan region. A significant negative correlation was found of daily pollen counts with minimum temperature, relative humidity and rainfall. PMID:19061265

  2. Impact of land cover changes and climate on the main airborne pollen types in Southern Spain.

    PubMed

    García-Mozo, Herminia; Oteros, Jose Antonio; Galán, Carmen

    2016-04-01

    Airborne pollen concentrations strongly correlate with flowering intensity of wind-pollinated species growing at and around monitoring sites. The pollen spectrum, and the variations in its composition and concentrations, is influenced by climatic features and by available nutritional resources but it is also determined by land use and its changes. The first factor influence is well known on aerobiological researches but the impact of land cover changes has been scarcely studied until now. This paper reports on a study carried out in Southern Spain (Córdoba city) examining airborne pollen trends over a 15-year period and it explores the possible links both to changes in land use and to climate variations. The Seasonal-Trend Decomposition procedure based on Loess (STL) which decomposes long-term data series into smaller seasonal component patterns was applied. Trends were compared with recorded changes in land use at varying distances from the city in order to determine their possible influence on pollen-count variations. The influence of climate-related factors was determined by means of non-parametric correlation analysis. The STL method proved highly effective for extracting trend components from pollen time series, because their features vary widely and can change quickly in a short term. Results revealed mixed trends depending on the taxa and reflecting fluctuations in land cover and/or climate. A significant rising trend in Olea pollen counts was observed, attributable both to the increasing olive-growing area but also to changes in temperature and rainfall. Poaceae pollen concentrations also increased, due largely to an expansion of heterogeneous agricultural areas and to an increase in pollen season length positively influenced by rainfall and temperature. By contrast, the significant declining trend observed for pollen from ruderal taxa, such as Amaranthaceae, Rumex, Plantago and Urticaceae, may be linked to changes in urban planning strategies with a

  3. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  4. Airborne pollen of allergenic herb species in Toledo (Spain).

    PubMed

    Vaquero, Consolación; Rodríguez-Torres, Alfonso; Rojo, Jesús; Pérez-Badia, Rosa

    2013-01-01

    This study analysed airborne pollen counts for allergenic herb taxa in Toledo (central Spain), a major tourist city receiving over 2 million visitors per year, located in the region of Castilla-La Mancha. The taxa selected were Chenopodiaceae-Amaranthaceae, Plantago, Poaceae and Urticaceae, all of which produce allergenic pollen giving rise to serious symptoms in pollen-allergy sufferers. Aerobiological data were recorded over a 6-year period (2005 to 2010) using the sampling and analysis procedures recommended by the Spanish Aerobiology Network. The abundance and the temporal (annual, daily and intradiurnal) distribution of these pollen types were analysed, and the influence of weather-related factors on airborne pollen counts was assessed. Pollen from herbaceous species accounted for 20.9% of total airborne pollen in Toledo, the largest contributor being Poaceae, with 8.5% of the total pollen count; this family was also the leading cause of respiratory allergies. Examination of intradiurnal variation revealed three distinct distribution patterns: (1) peak daily counts for Chenopodiaceae-Amaranthaceae and Plantago were recorded during the hottest part of the day, i.e. from 1400 to 1600 hours; (2) Urticaceae displayed two peaks (1400-1600 and 2200 hours); and (3) Poaceae counts remained fairly stable throughout the day. Two main risk periods were identified for allergies: spring, with allergies caused by Urticaceae, Plantago and Poaceae pollen, and summer, due to Chenopodiaceae-Amaranthaceae pollen. PMID:22331454

  5. Models for forecasting airborne Cupressaceae pollen levels in central Spain

    NASA Astrophysics Data System (ADS)

    Sabariego, Silvia; Cuesta, Pedro; Fernández-González, Federico; Pérez-Badia, Rosa

    2012-03-01

    The influence of meteorological variables on airborne Cupressaceae pollen levels in central Spain was analyzed, and prediction models based on polynomial and multiple regressions were used to predict pollen counts throughout the pollen season. The Cupressaceae pollen type was selected in view of both its abundance in the atmosphere of the central Iberian Peninsula (particularly from January to March) and its allergenic importance. Sampling was performed uninterruptedly over a 5-year period, using a Hirst volumetric sampler and the sampling method established by the Spanish Aerobiology Network. Temperature displayed the strongest (positive) correlation with Cupressaceae pollen counts. Polynomial and multiple regression analysis showed that maximum temperature was the most influential variable included in prediction models. The prediction equations obtained for the study period were reasonably satisfactory, accounting for 48% and 59% of the variation in airborne pollen levels.

  6. Airborne pollen trends in the Iberian Peninsula.

    PubMed

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants. PMID:26803684

  7. Characterisation of particulate matter on airborne pollen grains.

    PubMed

    Ribeiro, Helena; Guimarães, Fernanda; Duque, Laura; Noronha, Fernando; Abreu, Ilda

    2015-11-01

    A characterization of the physical-chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles' equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical-chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity. PMID:26141127

  8. Effect of land uses and wind direction on the contribution of local sources to airborne pollen.

    PubMed

    Rojo, Jesús; Rapp, Ana; Lara, Beatriz; Fernández-González, Federico; Pérez-Badia, Rosa

    2015-12-15

    The interpretation of airborne pollen levels in cities based on the contribution of the surrounding flora and vegetation is a useful tool to estimate airborne allergen concentrations and, consequently, to determine the allergy risk for local residents. This study examined the pollen spectrum in a city in central Spain (Guadalajara) and analysed the vegetation landscape and land uses within a radius of 20km in an attempt to identify and locate the origin of airborne pollen and to determine the effect of meteorological variables on pollen emission and dispersal. The results showed that local wind direction was largely responsible for changes in the concentrations of different airborne pollen types. The land uses contributing most to airborne pollen counts were urban green spaces, though only 0.1% of the total surface area studied, and broadleaved forest which covered 5% of the study area. These two types of land use together accounted for 70% of the airborne pollen. Crops, scrubland and pastureland, though covering 80% of the total surface area, contributed only 18.6% to the total pollen count, and this contribution mainly consisted of pollen from Olea and herbaceous plants, including Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Pollen from ornamental species were mainly associated with easterly (Platanus), southerly (Cupressaceae) and westerly (Cupressaceae and Platanus) winds from the areas where the city's largest parks and gardens are located. Quercus pollen was mostly transported by winds blowing in from holm-oak stands on the eastern edge of the city. The highest Populus pollen counts were associated with easterly and westerly winds blowing in from areas containing rivers and streams. The airborne pollen counts generally rose with increasing temperature, solar radiation and hours of sunlight, all of which favour pollen release. In contrast, pollen counts declined with increased relative humidity and rainfall, which hinder airborne pollen transport

  9. Elemental characterization of the airborne pollen surface using Electron Probe Microanalysis (EPMA)

    NASA Astrophysics Data System (ADS)

    Duque, Laura; Guimarães, Fernanda; Ribeiro, Helena; Sousa, Raquel; Abreu, Ilda

    2013-08-01

    Recent worldwide increase in pollinoses has been attributed to the synergy between pollen and pollutants. We used EPMA for the elemental characterization of the airborne pollen surface in order to find out what occurs to the wall of pollen grains when they are together with other atmospheric pollutants. Analyses were performed both to airborne pollen and to pollen that was collected from Acer spp., Platanus spp. and Pinus spp. trees. Airborne samples were assembled using a Hirst-type volumetric spore sampler set in the coastal city of Porto, Portugal. Airborne pollen samples showed major elemental differences when compared to the control pollen sample of the same species, namely in the amounts of Cl, Na and Mg, which very significantly increased on airborne samples, revealing an important influence of the ocean. Mineral dust also contributed to modify the pollen surface, by increasing Si contents on Acer spp. and Platanus spp. airborne pollen. Our results revealed consistent positive effects of the relative humidity and the precipitation in the increase of Cl, Na and Mg relative amounts on the pollen surface. This study shows that pollen grains have the ability to adsorb and/or absorb other materials, which may contribute to enhance pollen's harmful effects on people's health.

  10. The occurrence and allergising potential of airborne pollen in West Bengal, India.

    PubMed

    Boral, Dola; Chatterjee, Soma; Bhattacharya, Kashinath

    2004-01-01

    A continuous 2-year volumetric aerobiological survey was conducted in Berhampore town, a centrally located and representative part of West Bengal, India. The aim of the study was to assess the allergising potential of airborne pollen grains of West Bengal. A total of 31 pollen types were identified of which Poaceae (grasses) pollen showed maximum frequency, followed by Cyperaceae, Cassia sp., Acacia auriculiformis, etc. The seasonal periodicities of the pollen types and their relationship to meteorological conditions were investigated. It was found that the pollen concentration is positively correlated with temperature and negatively correlated with rainfall and relative humidity. Clinical investigations by skin prick test were carried out to detect allergenicity of pollen types. Eighteen common airborne pollen types induced positive responses of which pollen extracts of Saccharum officinarum (grass), Azadirachta indica, Cocos nucifera, Phoenix sylvestris, Cyperus rotundus and Eucalyptus citriodora showed strongest sensitising potential. This result is consistent with previous investigations in different parts of West Bengal. PMID:15236497

  11. Analysis of airborne pollen concentrations in Zagreb, Croatia, 2002.

    PubMed

    Peternel, Renata; Culig, Josip; Mitić, Bozena; Vukusić, Ivan; Sostar, Zvonimir

    2003-01-01

    Employing the volumetric method by use of a Hirst sampler, a total of 71,286 pollen grains, as many as 94.20% of them allergenic, were recorded in the air samples from the city of Zagreb during the 2002 pollen season. Among identified pollen of 35 plant species/genera/families, 23 were allergenic: Taxus/Juniperus, Alnus sp., Fraxinus sp., Betula sp., Corylus sp., Poaceae, Urticaceae, Artemisia sp., Ambrosia sp., Carpinus sp., Castanea sp., Chenopodiaceae, Salix sp., Populus sp., Ulmus sp., Juglans sp., Quercus sp., Platanus sp., Fagus sp., Plantago sp., Pinus sp., Picea sp. and Abies sp. The pollen of these plants also cause the majority of pollinosis in Europe. Study results and the pollen calendar designed for the 2002 pollen season for the City of Zagreb provide useful data for allergologists to reach an accurate diagnosis. The calendar also provides timely information on airborne pollen types and air concentrations for individuals with pollen hypersensitivity, thus allowing them to adjust their daily activities so as to minimize their contact with allergens and improve their quality of life both at home and at work. PMID:12852741

  12. Characterisation of the airborne pollen spectrum in Guadalajara (central Spain) and estimation of the potential allergy risk.

    PubMed

    Rojo, Jesús; Rapp, Ana; Lara, Beatriz; Sabariego, Silvia; Fernández-González, Federico; Pérez-Badia, Rosa

    2016-03-01

    Aerobiological research into airborne pollen diversity and seasonal variations in pollen counts has become increasingly important over recent decades due to the growing incidence of asthma, rhinitis and other pollen-related allergic conditions. Airborne pollen in Guadalajara (Castilla-La Mancha, Spain) was studied over a 6-year period (2008-2013) using a Hirst-type volumetric spore trap. The highest pollen concentrations were recorded from February to June, coinciding with the pollen season of the pollen types that most contribute to the local airborne pollen spectrum: Cupressaceae (32.2%), Quercus (15.1%), Platanus (13.2%), Olea (8.3%), Populus (7.8%) and Poaceae (7.2%). These are therefore critical months for allergy sufferers. The pollen calendar was typically Mediterranean and comprised 25 pollen types. Between January and March, Cupressaceae pollen concentrations exceeded allergy risk thresholds on 38 days. Other woody species such as Olea and Platanus have a shorter pollen season, and airborne concentrations exceeded allergy risk thresholds on around 13 days in each case. Poaceae pollen concentrations attained allergy risk levels on 26 days between May and July. Other highly allergenic pollen types included Urticaceae and Chenopodiaceae-Amaranthaceae, though these are less abundant than other pollen types in Guadalajara and did not exceed risk thresholds on more than 3 and 5 days, respectively. PMID:26832913

  13. Wavelet-based fractal analysis of airborne pollen

    NASA Astrophysics Data System (ADS)

    Degaudenzi, M. E.; Arizmendi, C. M.

    1999-06-01

    The most abundant biological particles in the atmosphere are pollen grains and spores. Self-protection of a pollen allergy is possible through information about future pollen contents in the air. In spite of the importance of airborne pollen concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of daily pollen forecasts result in failures. Previous analyses of the dynamic characteristics of atmospheric pollen time series indicate that the system can be described by a low dimensional chaotic map. We apply a wavelet transform to study the multifractal characteristics of an airborne pollen time series. The information and the correlation dimensions correspond to a chaotic system showing a loss of information with time evolution.

  14. Fifteen years' record of airborne allergenic pollen and meteorological parameters in Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Gioulekas, Dimitrios; Balafoutis, Christos; Damialis, Athanasios; Papakosta, Despoina; Gioulekas, George; Patakas, Dimitrios

    . A pollen calendar has been constructed for the area of Thessaloniki and relationships between pollen transport and meteorological parameters have been assessed. Daily airborne pollen records were collected over a 15-year period (1987-2001), using a Burkard continuous volumetric pollen trap, located in the centre of the city. Sixteen allergenic pollen types were identified. Simultaneously, daily records of five main meteorological parameters (mean air temperature, relative humidity, rainfall, sunshine, wind speed) were made, and then correlated with fluctuations of the airborne pollen concentrations. For the first time in Greece, a pollen calendar has been constructed for 16 pollen types, from which it appears that 24.9% of the total pollen recorded belong to Cupressaceae, 20.8% to Quercus spp., 13.6% to Urticaceae, 9.1% to Oleaceae, 8.9% to Pinaceae, 6.3% to Poaceae, 5.4% to Platanaceae, 3.0% to Corylus spp., 2.5% to Chenopodiaceae and 1.4% to Populus spp. The percentages of Betula spp., Asteraceae (Artemisia spp. and Ambrosia spp.), Salix spp., Ulmaceae and Alnus spp. were each lower than 1%. A positive correlation between pollen transport and both mean temperature and sunshine was observed, whereas usually no correlation was found between pollen and relative humidity or rainfall. Finally, wind speed was generally found to have a significant positive correlation with the concentrations of 8 pollen types. For the first time in the area of Thessaloniki, and more generally in Greece, 15-year allergenic pollen records have been collected and meteorological parameters have been recorded. The airborne pollen concentration is strongly influenced by mean air temperature and sunshine duration. The highest concentrations of pollen grains are observed during spring (May).

  15. Airborne pollen and spores of León (Spain)

    NASA Astrophysics Data System (ADS)

    Fernández-González, Delia; Suarez-Cervera, María; Díaz-González, Tomás; Valencia-Barrera, Rosa María

    1993-06-01

    A qualitative and quantitative analysis of airborne pollen and spores was carried out over 2 years (from September 1987 to August 1989) in the city of León. Slides were prepared daily using a volumetric pollen trap, which was placed on the Faculty of Veterinary Science building (University of León) 12m above ground-level. Fifty-one pollen types were observed; the most important of these were: Cupressaceae during the winter, Pinus and Quercus in spring, and Poaceae, Leguminosae and Chenopodiaceae in the summer. The results also showed the existence of a rich mould spore assemblage in the atmosphere. The group of Amerospores ( Penicillium, Aspergillus and Cladosporium) as well as Dictyospores ( Alternaria) were the most abundant; Puccinia was common in the air in August. Fluctuations in the total pollen and spores m3 of air were compared with meteorological parameters (temperature, relative humidity and rainfall). From the daily sampling of the atmosphere of León, considering the maximum and minimum temperature and duration of rainfall, the start of the pollen grain season was observed generally to coincide with a rise in temperature in the absence of rain.

  16. Diurnal variation in airborne pollen concentrations of the selected taxa in Zagreb, Croatia.

    PubMed

    Toth, Ivan; Peternel, Renata; Srnec, Lidija; Vojniković, Bozo

    2011-09-01

    The number of individuals allergic to plant pollen has recently been on a constant increase. The knowledge of diurnal distribution and abundance of allergenic pollen types, their patterns and response to source position and weather is useful to correlate hay fever symptoms with the presence of allergenic pollen in the atmosphere. The aim of this study was to determine diurnal distribution of total airborne pollen, pollen of particular allergenic taxa, possible variation in diurnal pollen distribution at measuring sites placed at different heights, and effect of some meteorological parameters on airborne pollen concentrations. A 7-day Hirst-type volumetric pollen trap was used for pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). Total pollen of all plant taxa (Ambrosia sp., Betula sp., Cupressaceae, Urticaceae, Poaceae, Quercus sp., Fraxinus sp., Alnus sp., Corylus sp., Populus sp., Pinus sp., Picea sp.) observed showed a regular diurnal distribution at both sampling sites in both study years, with a rise in the pollen concentration recorded after 4.00 a.m. and 6.00 a.m., respectively. The peak pollen concentration occurred between 12.00 a.m. and 4.00 p.m., and the lowest diurnal pollen concentrations were recorded overnight. About 50% of the 24-h pollen concentration were released to the atmosphere between 10.00 a.m. and 4.00 p.m. The timing and size of diurnal peaks were closely related to high temperature, low humidity and south-west maximum wind direction. PMID:22220402

  17. Variations of airborne winter pollen in southern Spain.

    PubMed

    Ruiz de Clavijo, E; Galán, C; Infante, F; Domínguez, E

    1988-01-01

    This work deals with the variation in the atmosphere of the airborne pollen produced by winter blooming plants and is aimed to establish correlations between the concentration of pollen grains in the atmosphere of Córdoba and meteorological parameters such as the temperature, humidity, rainfall, pressure, hours of sunlight and wind speed and direction. The work was conducted for two consecutive years (1981-82 and 1982-83). The sampling was carried out in Córdoba (Spain) with a BURKARD sporetrap. The data obtained in the aeropalinological study are correlated to the above-mentioned meterological parameters. Along the period investigated grains were found from Ulmus minor, Fraxinus sp., Populus sp., Alnus glutinosa and Cupressaceae, and less frequently, Artemisia sp., Pinaceae, Urticaceae, type Helianthus and Gramineae. Pollen grains from Cupressaceae were found at the highest absolute and relative concentrations in the atmosphere of Córdoba during the winter, where they occurred almost throughout. The correlation analysis applied showed that the parameters most markedly influencing the grain concentration of most taxa were the temperature and humidity. Alnus glutinosa was the least affected species, probably because of the scarcity of its pollen grains. PMID:3177155

  18. Ambrosia airborne pollen concentration modelling and evaluation over Europe

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Viovy, Nicolas; Khvorostyanov, Dmitry; Colette, Augustin

    2014-05-01

    Native from North America, Ambrosia artemisiifolia L. (Common Ragweed) is an invasive annual weed introduced in Europe in the mid-nineteenth century. It has a very high spreading potential throughout Europe and releases very allergenic pollen leading to health problems for sensitive persons. Because of its health effects, it is necessary to develop modelling tools to be able to forecast ambrosia air pollen concentration and to inform allergy populations of allergenic threshold exceedance. This study is realised within the framework of the ATOPICA project (https://www.atopica.eu/) which is designed to provide first steps in tools and estimations of the fate of allergies in Europe due to changes in climate, land use and air quality. To calculate and predict airborne concentrations of ambrosia pollen, a chain of models has been built. Models have been developed or adapted for simulating the phenology (PMP phonological modelling platform), inter-annual production (ORCHIDEE vegetation model), release and airborne processes (CHIMERE chemical transport model) of ragweed pollen. Airborne pollens follow processes similar to air quality pollutants in CHIMERE with some adaptations. The detailed methodology, formulations and input data will be presented. A set of simulations has been performed to simulate airborne concentrations of pollens over long time periods on a large European domain. Hindcast simulations (2000 - 2012) driven by ERA-Interim re-analyses are designed to best simulate past periods airborne pollens. The modelled pollen concentrations are calibrated with observations and validated against additional observations. Then, 20-year long historical simulations (1986 - 2005) are carried out using calibrated ambrosia density distribution and climate model-driven weather in order to serve as a control simulation for future scenarios. By comparison with multi-annual observed daily pollen counts we have shown that the model captures well the gross features of the pollen

  19. Detection of airborne allergen (Pla a 1) in relation to Platanus pollen in Córdoba, South Spain.

    PubMed

    Alcázar, Purificación; Galán, Carmen; Torres, Carmen; Domínguez-Vilches, Eugenio

    2015-01-01

    Córdoba is one of the Spanish cities with the highest records of plane tree pollen grains in the air. Clinical studies have identified Platanus as a major cause of pollinosis. This fact provokes an important public health problem during early spring when these trees bloom. The objective of the study is to evaluate the correlation between airborne pollen counts and Pla a 1 aeroallergen concentrations in Córdoba, to elucidate if airborne pollen can be an accurate measure that helps to explain the prevalence of allergenic symptoms. Pollen sampling was performed during 2011-2012 using a Hirst-type sampler. Daily average concentration of pollen grains (pollen grains/m 3 ) was obtained following the methodology proposed by the Spanish Aerobiology Network. A multi-vial cyclone was used for the aeroallergen quantification. Allergenic particles were measured by ELISA using specific antibodies Pla a 1. The trend of Platanus pollen was characterized by a marked seasonality, reaching high concentrations in a short period of time. Airborne pollen and aeroallergen follow similar trends. The overlapping profile between both variables during both years shows that pollen and Pla a 1 are significantly correlated. The highest significant correlation coefficients were obtained during 2011 and for the post peak. Although some studies have found notable divergence between pollen and allergen concentrations in the air, in the case of Platanus in Córdoba, similar aerobiological dynamics between pollen and Pla a 1 have been found. Allergenic activity was found only during the plane tree pollen season, showing a close relationship with daily pollen concentrations. The obtained pollen potency was similar for both years of study. The results suggest that the allergenic response in sensitive patients to plane tree pollen coincide with the presence and magnitude of airborne pollen. PMID:25780836

  20. Correlation between airborne Olea europaea pollen concentrations and levels of the major allergen Ole e 1 in Córdoba, Spain, 2012-2014

    NASA Astrophysics Data System (ADS)

    Plaza, M. P.; Alcázar, P.; Galán, C.

    2016-04-01

    Olea europaea L. pollen is the second-largest cause of pollinosis in the southern Iberian Peninsula. Airborne-pollen monitoring networks provide essential data on pollen dynamics over a given study area. Recent research, however, has shown that airborne pollen levels alone do not always provide a clear indicator of actual exposure to aeroallergens. This study sought to evaluate correlations between airborne concentrations of olive pollen and Ole e 1 allergen levels in Córdoba (southern Spain), in order to determine whether atmospheric pollen concentrations alone are sufficient to chart changes in hay fever symptoms. The influence of major weather-related variables on local airborne pollen and allergen levels was also examined. Monitoring was carried out from 2012 to 2014. Pollen sampling was performed using a Hirst-type sampler, following the protocol recommended by the Spanish Aerobiology Network. A multi-vial cyclone sampler was used to collect aeroallergens, and allergenic particles were quantified by ELISA assay. Significant positive correlations were found between daily airborne allergen levels and atmospheric pollen concentrations, although there were occasions when allergen was detected before and after the pollen season and in the absence of airborne pollen. The correlation between the two was irregular, and pollen potency displayed year-on-year variations and did not necessarily match pollen-season-intensity.

  1. Quantitative DNA Analyses for Airborne Birch Pollen

    PubMed Central

    Müller-Germann, Isabell; Vogel, Bernhard; Vogel, Heike; Pauling, Andreas; Fröhlich-Nowoisky, Janine; Pöschl, Ulrich; Després, Viviane R.

    2015-01-01

    Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR), which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm) and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8) and the other for a multi-copy gene (ITS). The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm), the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future. PMID:26492534

  2. Meteorological variables connected with airborne ragweed pollen in Southern Hungary.

    PubMed

    Makra, L; Juhász, M; Borsos, E; Béczi, R

    2004-09-01

    About 30% of the Hungarian population has some type of allergy, 65% of them have pollen sensitivity, and at least 60% of this pollen sensitivity is caused by ragweed. The short (or common) ragweed (Ambrosia artemisiifolia = Ambrosia elatior) has the most aggressive pollen of all. Clinical investigations prove that its allergenic pollen is the main reason for the most massive, most serious and most long-lasting pollinosis. The air in the Carpathian Basin is the most polluted with ragweed pollen in Europe. The aim of the study is to analyse how ragweed pollen concentration is influenced by meteorological elements in a medium-sized city, Szeged, Southern Hungary. The data basis consists of daily ragweed pollen counts and averages of 11 meteorological parameters for the 5-year daily data set, between 1997 and 2001. The study considers some of the ragweed pollen characteristics for Szeged. Application of the Makra test indicates the same period for the highest pollen concentration as that established by the main pollination period. After performing factor analysis for the daily ragweed pollen counts and the 11 meteorological variables examined, four factors were retained that explain 84.4% of the total variance of the original 12 variables. Assessment of the daily pollen number was performed by multiple regression analysis and results based on deseasonalised and original data were compared. PMID:15103548

  3. Airborne castanea pollen forecasting model for ecological and allergological implementation.

    PubMed

    Astray, G; Fernández-González, M; Rodríguez-Rajo, F J; López, D; Mejuto, J C

    2016-04-01

    Castanea sativa Miller belongs to the natural vegetation of many European deciduous forests prompting impacts in the forestry, ecology, allergological and chestnut food industry fields. The study of the Castanea flowering represents an important tool for evaluating the ecological conservation of North-Western Spain woodland and the possible changes in the chestnut distribution due to recent climatic change. The Castanea pollen production and dispersal capacity may cause hypersensitivity reactions in the sensitive human population due to the relationship between patients with chestnut pollen allergy and a potential cross reactivity risk with other pollens or plant foods. In addition to Castanea pollen's importance as a pollinosis agent, its study is also essential in North-Western Spain due to the economic impact of the industry around the chestnut tree cultivation and its beekeeping interest. The aim of this research is to develop an Artificial Neural Networks for predict the Castanea pollen concentration in the atmosphere of the North-West Spain area by means a 20years data set. It was detected an increasing trend of the total annual Castanea pollen concentrations in the atmosphere during the study period. The Artificial Neural Networks (ANNs) implemented in this study show a great ability to predict Castanea pollen concentration one, two and three days ahead. The model to predict the Castanea pollen concentration one day ahead shows a high linear correlation coefficient of 0.784 (individual ANN) and 0.738 (multiple ANN). The results obtained improved those obtained by the classical methodology used to predict the airborne pollen concentrations such as time series analysis or other models based on the correlation of pollen levels with meteorological variables. PMID:26802339

  4. Controlling the levels of airborne pollen: can heterogeneous photocatalysis help?

    PubMed

    Sapiña, M; Jimenez-Relinque, E; Castellote, M

    2013-10-15

    Airborne pollen is a worldwide problem because is a very important allergenic agent; it can be altered only by certain microorganisms and by some oxidizers, such as reactive oxygen species (ROS). On the other hand, heterogeneous photocatalysis (HPC) arose as a promising technology for reducing the level of contaminants in the air, based on their degradation by the production of ROS. In this paper, study of the feasibility of HPC to diminish the counts of pollen is undertaken. The research has been carried out at different levels, from solutions to mortar specimens with the evidence that HPC is able to reduce the amount of pollen grains. This is a major breakthrough that opens the door to a whole field of research, already full of gaps, whose implications could be quite controversial. PMID:24063577

  5. Modelling airborne concentration and deposition rate of maize pollen

    NASA Astrophysics Data System (ADS)

    Jarosz, Nathalie; Loubet, Benjamin; Huber, Laurent

    2004-10-01

    The introduction of genetically modified (GM) crops has reinforced the need to quantify gene flow from crop to crop. This requires predictive tools which take into account meteorological conditions, canopy structure as well as pollen aerodynamic characteristics. A Lagrangian Stochastic (LS) model, called SMOP-2D (Stochastic Mechanistic model for Pollen dispersion and deposition in 2 Dimensions), is presented. It simulates wind dispersion of pollen by calculating individual pollen trajectories from their emission to their deposition. SMOP-2D was validated using two field experiments where airborne concentration and deposition rate of pollen were measured within and downwind from different sized maize (Zea mays) plots together with micrometeorological measurements. SMOP-2D correctly simulated the shapes of the concentration profiles but generally underestimated the deposition rates in the first 10 m downwind from the source. Potential explanations of this discrepancy are discussed. Incorrect parameterisation of turbulence in the transition from the crop to the surroundings is probably the most likely reason. This demonstrates that LS models for particle transfer need to be coupled with air-flow models under complex terrain conditions.

  6. Enhanced airborne radioactivity during a pine pollen release episode.

    PubMed

    Tschiersch, J; Frank, G; Roth, P; Wagenpfeil, F; Watterson, F; Watterson, J

    1999-07-01

    A single episode of pine pollen release in the highly contaminated area of Novozybkov, Russian Federation, which led to enhanced atmospheric concentrations of 137Cs is discussed. The pollen grains were sampled by a rotating arm impactor and analysed by gamma-spectrometry for 137Cs activity and by image analysis for their size. In the vicinity of a forest, a maximum concentration of 4.5+/-0.4 mBq m(-3) was measured, and a mean activity per pollen grain of 260+/-80 nBq was determined. The emission rate of the Novozybkov mixed pine forest was estimated to be approximately 400 Bq m(-2) per year. Because of the large size of pine pollen grains (about 50 microm) and the short emission period of 5-8 days per year, the estimated potential annual inhalation doses are very low. Biological emissions including pollen release may be a source of increased airborne radionuclide concentrations at larger distances from the source areas as well. PMID:10461761

  7. Physico-chemical characteristics of visibility impairment by airborne pollen in an urban area

    NASA Astrophysics Data System (ADS)

    Kim, Kyung W.

    The number of airborne pollen produced from plants is visible as a haze mixed with urban air pollution in an urban area when atmospheric conditions are proper for pollination of pollen from April to May in Korea. The big loading of airborne pollen can cause further visibility degradation in an urban area. In order to investigate physico-chemical characteristics of visibility impairment by airborne pollen, chemical aerosol measurements, optical aerosol monitoring, and scenic monitoring were performed during the intensive monitoring period from April 19 to May 2, 2005 in the urban area of Seoul, Korea. The particles collected on filters were examined with a scanning electron microscope (SEM) interfaced with an energy dispersive X-ray analysis to characterize size, elemental composition, and count of airborne pollen. During the airborne pollen period, the daily averaged number concentrations of airborne pollen; P and P were calculated to be 8.4±6.9 and 113.7±91.1 m -3, respectively. The daily averaged light extinction coefficient ( bext), light scattering coefficient for open path ( bscat), light scattering coefficient for dry particle in the fine regime ( bscat,fine), and light absorption coefficient in the fine regime ( babs,fine) were measured to be 459±267, 357±214, 263±165, and 44±30 Mm -1, respectively. And mass concentration of PM 2.5 and PM 10 were measured to be 46.5±29.1 and 97.0±41.7 μg m -3. The average light absorption coefficient by airborne pollen was estimated to be about 30 M m -1 and the average light scattering coefficient by airborne pollen was estimated to be 67±57 Mm -1. During the airborne pollen period the average contribution of airborne pollen to visibility impairment was roughly estimated to be 19-25%.

  8. Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Liu, Li; Solmon, Fabien; Viovy, Nicolas; Khvorostyanov, Dmitry; Essl, Franz; Chuine, Isabelle; Colette, Augustin; Semenov, Mikhail A.; Schaffhauser, Alice; Storkey, Jonathan; Thibaudon, Michel; Epstein, Michelle M.

    2015-08-01

    Common ragweed (Ambrosia artemisiifolia) is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals. Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios. We estimate that by 2050 airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change. The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy.

  9. Relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts.

    PubMed

    Yamamoto, Naomichi; Matsuki, Yuuki; Yokoyama, Hiromichi; Matsuki, Hideaki

    2015-01-01

    Japanese cedar pollinosis (JCP) is an important illness caused by the inhalation of airborne allergenic cedar pollens, which are dispersed in the early spring throughout the Japanese islands. However, associations between pollen exposures and the prevalence or severity of allergic symptoms are largely unknown, due to a lack of understanding regarding personal pollen exposures in relation to indoor and outdoor concentrations. This study aims to examine the relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts. We conducted a 4-year monitoring campaign to quantify indoor, outdoor, and personal airborne cedar pollen counts, where the personal passive settling sampler that has been previously validated against a volumetric sampler was used to count airborne pollen grains. A total of 256 sets of indoor, outdoor, and personal samples (768 samples) were collected from 9 subjects. Medians of the seasonally-integrated indoor-to-outdoor, personal-to-outdoor, and personal-to-indoor ratios of airborne pollen counts measured for 9 subjects were 0.08, 0.10, and 1.19, respectively. A greater correlation was observed between the personal and indoor counts (r = 0.89) than between the personal and outdoor counts (r = 0.71), suggesting a potential inaccuracy in the use of outdoor counts as a basis for estimating personal exposures. The personal pollen counts differed substantially among the human subjects (49% geometric coefficient of variation), in part due to the variability in the indoor counts that have been found as major determinants of the personal pollen counts. The findings of this study highlight the need for pollen monitoring in proximity to human subjects to better understand the relationships between pollen exposures and the prevalence or severity of pollen allergy. PMID:26110813

  10. Relationships among Indoor, Outdoor, and Personal Airborne Japanese Cedar Pollen Counts

    PubMed Central

    Yamamoto, Naomichi; Matsuki, Yuuki; Yokoyama, Hiromichi; Matsuki, Hideaki

    2015-01-01

    Japanese cedar pollinosis (JCP) is an important illness caused by the inhalation of airborne allergenic cedar pollens, which are dispersed in the early spring throughout the Japanese islands. However, associations between pollen exposures and the prevalence or severity of allergic symptoms are largely unknown, due to a lack of understanding regarding personal pollen exposures in relation to indoor and outdoor concentrations. This study aims to examine the relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts. We conducted a 4-year monitoring campaign to quantify indoor, outdoor, and personal airborne cedar pollen counts, where the personal passive settling sampler that has been previously validated against a volumetric sampler was used to count airborne pollen grains. A total of 256 sets of indoor, outdoor, and personal samples (768 samples) were collected from 9 subjects. Medians of the seasonally-integrated indoor-to-outdoor, personal-to-outdoor, and personal-to-indoor ratios of airborne pollen counts measured for 9 subjects were 0.08, 0.10, and 1.19, respectively. A greater correlation was observed between the personal and indoor counts (r = 0.89) than between the personal and outdoor counts (r = 0.71), suggesting a potential inaccuracy in the use of outdoor counts as a basis for estimating personal exposures. The personal pollen counts differed substantially among the human subjects (49% geometric coefficient of variation), in part due to the variability in the indoor counts that have been found as major determinants of the personal pollen counts. The findings of this study highlight the need for pollen monitoring in proximity to human subjects to better understand the relationships between pollen exposures and the prevalence or severity of pollen allergy. PMID:26110813

  11. Pollen loads of eucalypt and other pollen types in birds in NW Spain.

    PubMed

    Calviño-Cancela, María; Neumann, Max

    2015-12-01

    Here we present the amount of pollen of eucalypt and pollen of other types for birds captured in two bird ringing stations for 14 months (March 2014 to April 2015) in NW Spain. Common and latin names of all birds species captured, together with the number of captured individuals (N), prevalence of eucalypt pollen (percentage of individuals with eucalypt pollen) and of pollen of other types and average pollen loads per individual for eucalypt and other pollen types is presented. See [1] for further information and discussion. PMID:26568978

  12. Pollen loads of eucalypt and other pollen types in birds in NW Spain

    PubMed Central

    Calviño-Cancela, María; Neumann, Max

    2015-01-01

    Here we present the amount of pollen of eucalypt and pollen of other types for birds captured in two bird ringing stations for 14 months (March 2014 to April 2015) in NW Spain. Common and latin names of all birds species captured, together with the number of captured individuals (N), prevalence of eucalypt pollen (percentage of individuals with eucalypt pollen) and of pollen of other types and average pollen loads per individual for eucalypt and other pollen types is presented. See [1] for further information and discussion. PMID:26568978

  13. Airborne pollen in three European cities: Detection of atmospheric circulation pathways by applying three-dimensional clustering of backward trajectories

    NASA Astrophysics Data System (ADS)

    Makra, LáSzló; SáNta, TamáS.; Matyasovszky, IstváN.; Damialis, Athanasios; Karatzas, Kostas; Bergmann, Karl-Christian; Vokou, Despoina

    2010-12-01

    The long-range transport of particulates can substantially contribute to local air pollution. The importance of airborne pollen has grown due to the recent climate change; the lengthening of the pollen season and rising mean airborne pollen concentrations have increased health risks. Our aim is to identify atmospheric circulation pathways influencing pollen levels in three European cities, namely Thessaloniki, Szeged, and Hamburg. Trajectories were computed using the HYSPLIT model. The 4 day, 6 hourly three-dimensional (3-D) backward trajectories arriving at these locations at 1200 UT are produced for each day over a 5 year period. A k-means clustering algorithm using the Mahalanobis metric was applied in order to develop trajectory types. The delimitation of the clusters performed by the 3-D function "convhull" is a novel approach. The results of the cluster analysis reveal that the main pathways for Thessaloniki contributing substantially to the high mean Urticaceae pollen levels cover western Europe and the Mediterranean. The key pathway patterns for Ambrosia for Szeged are associated with backward trajectories coming from northwestern Europe, northeastern Europe, and northern Europe. A major pollen source identified is a cluster over central Europe, namely the Carpathian basin with peak values in Hungary. The principal patterns for Poaceae for Hamburg include western Europe and the mid-Atlantic region. Locations of the source areas coincide with the main habitat regions of the species in question. Critical daily pollen number exceedances conditioned on the clusters were also evaluated using two statistical indices. An attempt was made to separate medium- and long-range airborne pollen transport.

  14. [Seasonal Dynamics of Airborne Pollens and Its Relationship with Meteorological Factors in Beijing Urban Area].

    PubMed

    Meng, Ling; Wang, Xiao-ke; Ouyang, Zhi-yun; Ren, Yu-fen; Wang, Qiao-huan

    2016-02-15

    The seasonal dynamics of airborne pollens and their relationship with meteorological conditions, which are considered to be important factors for appropriate construction of urban green system and reliable prevention of tropic pollinosis, were investigated in Beijing urban area. The airborne pollens were monitored from December 31st 2011 to December 31st 2012 by Burkard volumetric trap, and the data were analyzed. The results revealed that: (1) In 2012 the pollen dispersion period lasted 238 days from March 17 to November 18th, accounting for 65% of the year. There were two peaks of pollen amount in air, which occurred from March to May and from August to October, respectively. In the spring peak, tree pollens such as Oleaceae, Populus and Salix pollens were the dominant, accounting for 53% of the total annual pollens, while in the autumn period, weed pollens such as Compositae, Chenopodiaceae and Amaranthaceae pollens made up about 40% of the annual total value; (2) The highly allergenic weeds pollens dominated in autumn, which caused a high incidence of tropic pollinosis; (3) The airborne pollen amount of Beijing urban area was significantly affected by meteorological condition like the wind speed, temperature, humidity, precipitation and so on; (4) When temperature ranged from OC to 15 degrees C, the pollen amount showed positive relation with temperature; while in the temperature range of 18 degrees C to 30 degrees C, it showed negative relation; (5) The average temperature of spring and autumn season in 2012 was 17 degrees C, and 79% of airborne pollens were detected in these two seasons. This temperature condition was conducive to the pollen dispersion. (6) The pollen amount showed negative relation with relative moisture between 20% and 50% and larger than 70%, while in the moisture range of 50% to 60%, it showed positive relation; (7) The wind speed smaller than 3 m x s(-1) was good to pollen distribution, when it was larger than 4 m x s(-1) or the wind

  15. On the causes of variability in amounts of airborne grass pollen in Melbourne, Australia

    NASA Astrophysics Data System (ADS)

    de Morton, Julian; Bye, John; Pezza, Alexandre; Newbigin, Edward

    2011-07-01

    In Melbourne, Australia, airborne grass pollen is the predominant cause of hay fever (seasonal rhinitis) during late spring and early summer, with levels of airborne grass pollen also influencing hospital admissions for asthma. In order to improve predictions of conditions that are potentially hazardous to susceptible individuals, we have sought to better understand the causes of diurnal, intra-seasonal and inter-seasonal variability of atmospheric grass pollen concentrations (APC) by analysing grass pollen count data for Melbourne for 16 grass pollen seasons from 1991 to 2008 (except 1994 and 1995). Some of notable features identified in this analysis were that on days when either extreme (>100 pollen grains m-3) or high (50-100 pollen grains m-3) levels of grass pollen were recorded the winds were of continental origin. In contrast, on days with a low (<20 pollen grains m-3) concentration of grass pollen, winds were of maritime origin. On extreme and high grass pollen days, a peak in APC occurred on average around 1730 hours, probably due to a reduction in surface boundary layer turbulence. The sum of daily APC for each grass pollen season was highly correlated ( r = 0.79) with spring rainfall in Melbourne for that year, with about 60% of a declining linear trend across the study period being attributable to a reduction of meat cattle and sheep (and hence grazing land) in rural areas around Melbourne. Finally, all of the ten extreme pollen events (3 days or more with APC > 100 pollen grains m-3) during the study period were characterised by an average downward vertical wind anomaly in the surface boundary layer over Melbourne. Together these findings form a basis for a fine resolution atmospheric general circulation model for grass pollen in Melbourne's air that can be used to predict daily (and hourly) APC. This information will be useful to those sectors of Melbourne's population that suffer from allergic problems.

  16. Influence of wind on daily airborne pollen counts in Catalonia (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    tareq Majeed, Husam; Periago, Cristina; Alarcón, Marta; De Linares, Concepción; Belmonte, Jordina

    2016-04-01

    The aim of this study is to analize the influence of wind (speed and direction) on the daily airborne pollen counts recorded in Catalonia (NE Iberian Peninsula) of 21 pollen taxa recorded at 6 aerobiological stations: Barcelona, Bellaterra, Girona, Lleida Manresa, and Tarragona for the period 2004-2014. The taxa studied are Alnus, Betula, Castanea, Cupressaceae, Fagus, Fraxinus, Olea, Pinus, Platanus, total Quercus, Quercus deciduous type, Quercus evergreen type, Ulmus, Corylus, Pistacia, Artemisia, Chenopodiaceae/Amaranthaceae, Plantago, Poaceae, Polygonaceae, and Urticaceae. The mean daily wind direction was divided into 8 sectors: N, NE, E, SE, S, SW, W and NW. For each sector, the correlation between the daily pollen concentrations and wind speed using Spearman's rank correlation coefficient was computed and compared with the wind rose charts. The results showed that Tarragona was the station with more significant correlations followed by Bellaterra, Lleida and Manresa. On the other hand, Artemisia was the most correlated taxon with mainly negative values, and Fagus was the least. The W wind direction showed the largest number of significant correlations, mostly positive, while the N direction was the least and negatively correlated.

  17. Environmental Factors Affecting Asthma and Allergies: Predicting and Simulating Downwind Exposure to Airborne Pollen

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey; Estes, Sue; Sprigg, William A.; Nickovic, Slobodan; Huete, Alfredo; Solano, Ramon; Ratana, Piyachat; Jiang, Zhangyan; Flowers, Len; Zelicoff, Alan

    2009-01-01

    This slide presentation reviews the environmental factors that affect asthma and allergies and work to predict and simulate the downwind exposure to airborne pollen. Using a modification of Dust REgional Atmosphere Model (DREAM) that incorporates phenology (i.e. PREAM) the aim was to predict concentrations of pollen in time and space. The strategy for using the model to simulate downwind pollen dispersal, and evaluate the results. Using MODerate-resolution Imaging Spectroradiometer (MODIS), to get seasonal sampling of Juniper, the pollen chosen for the study, land cover on a near daily basis. The results of the model are reviewed.

  18. Time series predictions with neural nets: Application to airborne pollen forecasting

    NASA Astrophysics Data System (ADS)

    Arizmendi, C. M.; Sanchez, J. R.; Ramos, N. E.; Ramos, G. I.

    1993-09-01

    Pollen allergy is a common disease causing rhinoconjunctivitis (hay fever) in 5 10% of the population. Medical studies have indicated that pollen related diseases could be highly reduced if future pollen contents in the air could be predicted. In this work we have developed a new forecasting method that applies the ability of neural nets to predict the future behaviour of chaotic systems in order to make accurate predictions of the airborne pollen concentration. The method requires that the neural net be fed with non-zero values, which restricts the method predictions to the period following the start of pollen flight. The operational method outlined here constitutes a different point of view with respect to the more generally used forecasts of time series analysis, which require input of many meteorological parameters. Excellent forecasts were obtained training a neural net by using only the time series pollen concentration values.

  19. Temporal modelling and forecasting of the airborne pollen of Cupressaceae on the southwestern Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Silva-Palacios, Inmaculada; Fernández-Rodríguez, Santiago; Durán-Barroso, Pablo; Tormo-Molina, Rafael; Maya-Manzano, José María; Gonzalo-Garijo, Ángela

    2016-02-01

    Cupressaceae includes species cultivated as ornamentals in the urban environment. This study aims to investigate airborne pollen data for Cupressaceae on the southwestern Iberian Peninsula over a 21-year period and to analyse the trends in these data and their relationship with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1993 to 2013 in Badajoz (SW Spain). The main pollen season for Cupressaceae lasted, on average, 58 days, ranging from 55 to 112 days, from 24 January to 22 March. Furthermore, a short-term forecasting model has been developed for daily pollen concentrations. The model proposed to forecast the airborne pollen concentration is described by one equation. This expression is composed of two terms: the first term represents the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term is obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological parameters multiplied by a fitting coefficient. Temperature was the main meteorological factor by its influence over daily pollen forecast, being the rain the second most important factor. This model represents a good approach to a continuous balance model of Cupressaceae pollen concentration and is supported by a close agreement between the observed and predicted mean concentrations. The novelty of the proposed model is the analysis of meteorological parameters that are not frequently used in Aerobiology.

  20. Temporal modelling and forecasting of the airborne pollen of Cupressaceae on the southwestern Iberian Peninsula.

    PubMed

    Silva-Palacios, Inmaculada; Fernández-Rodríguez, Santiago; Durán-Barroso, Pablo; Tormo-Molina, Rafael; Maya-Manzano, José María; Gonzalo-Garijo, Ángela

    2016-02-01

    Cupressaceae includes species cultivated as ornamentals in the urban environment. This study aims to investigate airborne pollen data for Cupressaceae on the southwestern Iberian Peninsula over a 21-year period and to analyse the trends in these data and their relationship with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1993 to 2013 in Badajoz (SW Spain). The main pollen season for Cupressaceae lasted, on average, 58 days, ranging from 55 to 112 days, from 24 January to 22 March. Furthermore, a short-term forecasting model has been developed for daily pollen concentrations. The model proposed to forecast the airborne pollen concentration is described by one equation. This expression is composed of two terms: the first term represents the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term is obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological parameters multiplied by a fitting coefficient. Temperature was the main meteorological factor by its influence over daily pollen forecast, being the rain the second most important factor. This model represents a good approach to a continuous balance model of Cupressaceae pollen concentration and is supported by a close agreement between the observed and predicted mean concentrations. The novelty of the proposed model is the analysis of meteorological parameters that are not frequently used in Aerobiology. PMID:26092133

  1. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

    PubMed Central

    Toro A., Richard; Córdova J., Alicia; Canales, Mauricio; Morales S., Raul G. E.; Mardones P., Pedro; Leiva G., Manuel A.

    2015-01-01

    Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. PMID:25946339

  2. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile.

    PubMed

    Toro A, Richard; Córdova J, Alicia; Canales, Mauricio; Morales S, Raul G E; Mardones P, Pedro; Leiva G, Manuel A

    2015-01-01

    Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009-2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. PMID:25946339

  3. Allergenic airborne pollen and spores in Anchorage, Alaska

    SciTech Connect

    Anderson, J.H.

    1985-05-01

    Major aeroallergens in Anchorage are birch, alder, poplar, spruce, grass pollen, Cladosporium, and unspecified fungus spores. Lesser pollens are sorrel, willow, pine, juniper, sedge, lamb's-quarters, wormwood, plantain, and others. The aero-flora is discussed in terms of the frequency of allergenically significant events and within-season and year-to-year dynamics.

  4. Airborne birch and grass pollen allergens in street-level shops.

    PubMed

    Holmquist, L; Weiner, J; Vesterberg, O

    2001-12-01

    Polluted urban outdoor air may be enriched with large amounts of submicronic respirable pollen allergen particles that penetrate into street-level shops. The objectives of the study were to map concentrations of birch and grass pollen allergens in indoor air of street-level shops and to explore the effect of electrostatic air cleaning under authentic working conditions, indoor air samples were collected in May and July 1999 in two shops. Allergens were quantified by a direct on sampling filter in solution (DOSIS) luminescence immunoassay. The average concentration of airborne indoor birch pollen allergen in the shop with air cleaning was estimated to be 20 +/- 9 SQ/m3 (mean +/- SD) compared to 31 +/- 17 SQ/m3 (mean +/- SD) of that without. The air cleaner reduced the indoor air birch pollen allergen concentration by on average 26 to 48% (P < 0.05). Corresponding figures for airborne indoor grass pollen allergen concentrations were 14 +/- 7 SQ/m3 and 17 +/- 8 SQ/m3, indicating a statistically non-significant (t-test) average 18% reduction of allergen by air cleaning. Excluding two observations with poor fit to the statistical model a significant (P < 0.05) average 27% reduction was obtained. Substantial amounts of airborne birch and grass pollen allergens may occur in street-level shops during flowering seasons. PMID:11761599

  5. The Macroecology of Airborne Pollen in Australian and New Zealand Urban Areas

    PubMed Central

    Haberle, Simon G.; Bowman, David M. J. S.; Newnham, Rewi M.; Johnston, Fay H.; Beggs, Paul J.; Buters, Jeroen; Campbell, Bradley; Erbas, Bircan; Godwin, Ian; Green, Brett J.; Huete, Alfredo; Jaggard, Alison K.; Medek, Danielle; Murray, Frank; Newbigin, Ed; Thibaudon, Michel; Vicendese, Don; Williamson, Grant J.; Davies, Janet M.

    2014-01-01

    The composition and relative abundance of airborne pollen in urban areas of Australia and New Zealand are strongly influenced by geographical location, climate and land use. There is mounting evidence that the diversity and quality of airborne pollen is substantially modified by climate change and land-use yet there are insufficient data to project the future nature of these changes. Our study highlights the need for long-term aerobiological monitoring in Australian and New Zealand urban areas in a systematic, standardised, and sustained way, and provides a framework for targeting the most clinically significant taxa in terms of abundance, allergenic effects and public health burden. PMID:24874807

  6. Detection of airborne genetically modified maize pollen by real-time PCR.

    PubMed

    Folloni, Silvia; Kagkli, Dafni-Maria; Rajcevic, Bojan; Guimarães, Nilson C C; Van Droogenbroeck, Bart; Valicente, Fernando H; Van den Eede, Guy; Van den Bulcke, Marc

    2012-09-01

    The cultivation of genetically modified (GM) crops has raised numerous concerns in the European Union and other parts of the world about their environmental and economic impact. Especially outcrossing of genetically modified organisms (GMO) was from the beginning a critical issue as airborne pollen has been considered an important way of GMO dispersal. Here, we investigate the use of airborne pollen sampling combined with microscopic analysis and molecular PCR analysis as an approach to monitor GM maize cultivations in a specific area. Field trial experiments in the European Union and South America demonstrated the applicability of the approach under different climate conditions, in rural and semi-urban environment, even at very low levels of airborne pollen. The study documents in detail the sampling of GM pollen, sample DNA extraction and real-time PCR analysis. Our results suggest that this 'GM pollen monitoring by bioaerosol sampling and PCR screening' approach might represent an useful aid in the surveillance of GM-free areas, centres of origin and natural reserves. PMID:22805239

  7. Immunologic, spectrophotometric and nucleic acid based methods for the detection and quantification of airborne pollen

    PubMed Central

    Rittenour, William R.; Hamilton, Robert G.; Beezhold, Donald H.; Green, Brett J.

    2015-01-01

    Microscopic identification of pollen morphological phenotypes has been the traditional method used to identify and quantify pollen collected by air monitoring stations worldwide. Although this method has enabled a semi-standardized approach for the assessment of pollen exposure, limitations including labor intensiveness, required expertise, examiner bias, and the inability to differentiate species, genera, and in some cases families have limited data derived from the these stations. Recent advances in chemical, biochemical and molecular detection methods have provided standardized alternatives to this microscopic approach. In this review, we examine the applicability of alternative methodologies, in particular nucleic acid based assays involving the quantitative polymerase chain reaction, for the standardized detection of airborne pollen. PMID:22342607

  8. Pla a_1 aeroallergen immunodetection related to the airborne Platanus pollen content.

    PubMed

    Fernández-González, M; Guedes, A; Abreu, I; Rodríguez-Rajo, F J

    2013-10-01

    Platanus hispanica pollen is considered an important source of aeroallergens in many Southern European cities. This tree is frequently used in urban green spaces as ornamental specie. The flowering period is greatly influenced by the meteorological conditions, which directly affect its allergenic load in the atmosphere. The purpose of this study is to develop equations to predict the Platanus allergy risk periods as a function of the airborne pollen, the allergen concentration and the main meteorological parameters. The study was conducted by means two volumetric pollen samplers; a Lanzoni VPPS 2000 for the Platanus pollen sampling and a Burkard multivial Cyclone Sampler to collect the aeroallergen particles (Pla a_1). In addiction the Dot-Blot and the Raman spectroscopy methods were used to corroborate the results. The Pla a_1 protein is recorded in the atmosphere after the presence of the Platanus pollen, which extend the Platanus pollen allergy risk periods. The Platanus pollen and the Pla a 1 allergens concentration are associated with statistical significant variations of some meteorological variables: in a positive way with the mean and maximum temperature whereas the sign of the correlation coefficient is negative with the relative humidity. The lineal regression equation elaborated in order to forecast the Platanus pollen content in the air explain the 64.5% of variance of the pollen presence in the environment, whereas the lineal regression equation elaborated in order to forecast the aeroallergen a 54.1% of the Pla a_1 presence variance. The combination of pollen count and the allergen quantification must be assessed in the epidemiologic study of allergic respiratory diseases to prevent the allergy risk periods. PMID:23867849

  9. Seasonal and intradiurnal variation of airborne pollen concentrations in Bodrum, SW Turkey.

    PubMed

    Tosunoglu, Aycan; Bicakci, Adem

    2015-04-01

    An aeropalynological study was performed in Bodrum, the famous tourism center in southwestern Turkey with a Hirst-type volumetric 7-day pollen and spore trap for 2 years (2007-2008). In Bodrum, 25,099 pollen grains as a mean value belonging to 41 taxa were recorded annually during the study period, and pollen grains from woody plant taxa had the largest atmospheric contribution of 86.99% and 24 taxa. However, 17 herbaceous plant taxa constituted 12.82% of the annual total pollen count, and 0.19% were unidentified. An average annual pollen index of 22.66% was recorded in March, despite differences from year to year. The highest pollen variability of 34 taxa was recorded in April and May. Predominant pollen types belonged to Cupressaceae/Taxaceae (42.73%), Quercus (15.95%), Pinus (9.78%), Olea europaea (9.04%), Poaceae (5.50%), Betula (1.82%), Pistacia (1.74%), Morus (1.72%), Urticaceae (1.46%), and Plantago (1.28%) and generated 91.03 of the annual total. In total, 32.59% of the mean annual total pollen index was recorded in the morning, and less pollen was recorded in the evening (18.71%). Maximum pollen concentration was recorded between 11:00 and 12:00 a.m. PMID:25750068

  10. Identification of potential sources of airborne Olea pollen in the Southwest Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Fernández-Rodríguez, S.; Ambelas Skjøth, C.; Tormo-Molina, R.; Brandao, R.; Caeiro, E.; Silva-Palacios, I.; Gonzalo-Garijo, Á.; Smith, M.

    2012-04-01

    This study aims to determine the potential origin of Olea pollen recorded in Badajoz in the Southwest of the Iberian Peninsula during 2009-2011. This was achieved using a combination of daily average and diurnal (hourly) airborne Olea pollen counts recorded at Badajoz (southwestern Spain) and Évora (southeastern Portugal), an inventory of olive groves in the studied area and air mass trajectory calculations computed using the HYSPLIT model. Examining olive pollen episodes at Badajoz that had distinctly different diurnal cycles in olive pollen in relation to the mean, allowed us to identify three different scenarios where olive pollen can be transported to the city from either distant or nearby sources. Back trajectory analysis showed that olive pollen can be transported to Badajoz from the West on prevailing winds, either directly or on slow moving air masses, and from high densities of olive groves situated to the Southeast (e.g. Andalucía). Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop.

  11. Models to predict the start of the airborne pollen season.

    PubMed

    Siniscalco, Consolata; Caramiello, Rosanna; Migliavacca, Mirco; Busetto, Lorenzo; Mercalli, Luca; Colombo, Roberto; Richardson, Andrew D

    2015-07-01

    Aerobiological data can be used as indirect but reliable measures of flowering phenology to analyze the response of plant species to ongoing climate changes. The aims of this study are to evaluate the performance of several phenological models for predicting the pollen start of season (PSS) in seven spring-flowering trees (Alnus glutinosa, Acer negundo, Carpinus betulus, Platanus occidentalis, Juglans nigra, Alnus viridis, and Castanea sativa) and in two summer-flowering herbaceous species (Artemisia vulgaris and Ambrosia artemisiifolia) by using a 26-year aerobiological data set collected in Turin (Northern Italy). Data showed a reduced interannual variability of the PSS in the summer-flowering species compared to the spring-flowering ones. Spring warming models with photoperiod limitation performed best for the greater majority of the studied species, while chilling class models were selected only for the early spring flowering species. For Ambrosia and Artemisia, spring warming models were also selected as the best models, indicating that temperature sums are positively related to flowering. However, the poor variance explained by the models suggests that further analyses have to be carried out in order to develop better models for predicting the PSS in these two species. Modeling the pollen season start on a very wide data set provided a new opportunity to highlight the limits of models in elucidating the environmental factors driving the pollen season start when some factors are always fulfilled, as chilling or photoperiod or when the variance is very poor and is not explained by the models. PMID:25234751

  12. Models to predict the start of the airborne pollen season

    NASA Astrophysics Data System (ADS)

    Siniscalco, Consolata; Caramiello, Rosanna; Migliavacca, Mirco; Busetto, Lorenzo; Mercalli, Luca; Colombo, Roberto; Richardson, Andrew D.

    2015-07-01

    Aerobiological data can be used as indirect but reliable measures of flowering phenology to analyze the response of plant species to ongoing climate changes. The aims of this study are to evaluate the performance of several phenological models for predicting the pollen start of season (PSS) in seven spring-flowering trees ( Alnus glutinosa, Acer negundo, Carpinus betulus, Platanus occidentalis, Juglans nigra, Alnus viridis, and Castanea sativa) and in two summer-flowering herbaceous species ( Artemisia vulgaris and Ambrosia artemisiifolia) by using a 26-year aerobiological data set collected in Turin (Northern Italy). Data showed a reduced interannual variability of the PSS in the summer-flowering species compared to the spring-flowering ones. Spring warming models with photoperiod limitation performed best for the greater majority of the studied species, while chilling class models were selected only for the early spring flowering species. For Ambrosia and Artemisia, spring warming models were also selected as the best models, indicating that temperature sums are positively related to flowering. However, the poor variance explained by the models suggests that further analyses have to be carried out in order to develop better models for predicting the PSS in these two species. Modeling the pollen season start on a very wide data set provided a new opportunity to highlight the limits of models in elucidating the environmental factors driving the pollen season start when some factors are always fulfilled, as chilling or photoperiod or when the variance is very poor and is not explained by the models.

  13. Identification of potential sources of airborne Olea pollen in the Southwest Iberian Peninsula.

    PubMed

    Fernández-Rodríguez, Santiago; Skjøth, Carsten Ambelas; Tormo-Molina, Rafael; Brandao, Rui; Caeiro, Elsa; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Angela; Smith, Matt

    2014-04-01

    This study aims to determine the potential origin of Olea pollen recorded in Badajoz in the Southwest of the Iberian Peninsula during 2009-2011. This was achieved using a combination of daily average and diurnal (hourly) airborne Olea pollen counts recorded at Badajoz (south-western Spain) and Évora (south-eastern Portugal), an inventory of olive groves in the studied area and air mass trajectory calculations computed using the HYSPLIT model. Examining olive pollen episodes at Badajoz that had distinctly different diurnal cycles in olive pollen in relation to the mean, allowed us to identify three different scenarios where olive pollen can be transported to the city from either distant or nearby sources during conditions with slow air mass movements. Back trajectory analysis showed that olive pollen can be transported to Badajoz from the West on prevailing winds, either directly or on slow moving air masses, and from high densities of olive groves situated to the Southeast (e.g. Andalucía). Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies that examine sources and the atmospheric transport of pollen are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop. PMID:23334443

  14. Identification of potential sources of airborne Olea pollen in the Southwest Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Fernández-Rodríguez, Santiago; Skjøth, Carsten Ambelas; Tormo-Molina, Rafael; Brandao, Rui; Caeiro, Elsa; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela; Smith, Matt

    2014-04-01

    This study aims to determine the potential origin of Olea pollen recorded in Badajoz in the Southwest of the Iberian Peninsula during 2009-2011. This was achieved using a combination of daily average and diurnal (hourly) airborne Olea pollen counts recorded at Badajoz (south-western Spain) and Évora (south-eastern Portugal), an inventory of olive groves in the studied area and air mass trajectory calculations computed using the HYSPLIT model. Examining olive pollen episodes at Badajoz that had distinctly different diurnal cycles in olive pollen in relation to the mean, allowed us to identify three different scenarios where olive pollen can be transported to the city from either distant or nearby sources during conditions with slow air mass movements. Back trajectory analysis showed that olive pollen can be transported to Badajoz from the West on prevailing winds, either directly or on slow moving air masses, and from high densities of olive groves situated to the Southeast (e.g. Andalucía). Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies that examine sources and the atmospheric transport of pollen are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop.

  15. Predicting onset and duration of airborne allergenic pollen season in the United States

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Bielory, Leonard; Cai, Ting; Mi, Zhongyuan; Georgopoulos, Panos

    2015-02-01

    Allergenic pollen is one of the main triggers of Allergic Airway Disease (AAD) affecting 5%-30% of the population in industrialized countries. A modeling framework has been developed using correlation and collinearity analyses, simulated annealing, and stepwise regression based on nationwide observations of airborne pollen counts and climatic factors to predict the onsets and durations of allergenic pollen seasons of representative trees, weeds and grass in the contiguous United States. Main factors considered are monthly, seasonal and annual mean temperatures and accumulative precipitations, latitude, elevation, Growing Degree Day (GDD), Frost Free Day (FFD), Start Date (SD) and Season Length (SL) in the previous year. The estimated mean SD and SL for birch (Betula), oak (Quercus), ragweed (Ambrosia), mugwort (Artemisia) and grass (Poaceae) pollen season in 1994-2010 are mostly within 0-6 days of the corresponding observations for the majority of the National Allergy Bureau (NAB) monitoring stations across the contiguous US. The simulated spatially resolved maps for onset and duration of allergenic pollen season in the contiguous US are consistent with the long term observations.

  16. Predicting Onset and Duration of Airborne Allergenic Pollen Season in the United States

    PubMed Central

    Zhang, Yong; Bielory, Leonard; Cai, Ting; Mi, Zhongyuan; Georgopoulos, Panos

    2014-01-01

    Allergenic pollen is one of the main triggers of Allergic Airway Disease (AAD) affecting 5% to 30% of the population in industrialized countries. A modeling framework has been developed using correlation and collinearity analyses, simulated annealing, and stepwise regression based on nationwide observations of airborne pollen counts and climatic factors to predict the onsets and durations of allergenic pollen seasons of representative trees, weeds and grass in the contiguous United States. Main factors considered are monthly, seasonal and annual mean temperatures and accumulative precipitations, latitude, elevation, Growing Degree Day (GDD), Frost Free Day (FFD), Start Date (SD) and Season Length (SL) in the previous year. The estimated mean SD and SL for birch (Betula), oak (Quercus), ragweed (Ambrosia), mugwort (Artemisia) and grass (Poaceae) pollen season in 1994–2010 are mostly within 0 to 6 days of the corresponding observations for the majority of the National Allergy Bureau (NAB) monitoring stations across the contiguous US. The simulated spatially resolved maps for onset and duration of allergenic pollen season in the contiguous US are consistent with the long term observations. PMID:25620875

  17. Masting in oaks: Disentangling the effect of flowering phenology, airborne pollen load and drought

    NASA Astrophysics Data System (ADS)

    Fernández-Martínez, Marcos; Belmonte, Jordina; Maria Espelta, Josep

    2012-08-01

    Quercus species exhibit an extreme inter-annual variability in seed production often synchronized over large geographical areas (masting). Since this reproductive behavior is mostly observed in anemophilous plants, pollination efficiency is suggested as one hypothesis to explain it, although resource-based hypotheses are also suggested as alternatives. We analyzed the effect of flowering phenology, airborne pollen presence and meteorological conditions in the pattern of acorn production in mixed evergreen-deciduous oak forests (Quercus ilex and Quercus pubescens) in NE Spain for twelve years (1998-2009). In both oaks, higher temperatures advanced the onset of flowering and increased the amount of airborne pollen. Nevertheless, inter-annual differences in pollen production did not influence acorn crop size. Acorn production was enhanced by a delay in flowering onset in Q. ilex but not in Q. pubescens. This suggests that in perennial oaks a larger number of photosynthates produced before flowering could benefit reproduction while the lack of effects on deciduous oaks could be because these species flush new leaves and flowers at the same time. Notwithstanding this effect, spring water deficit was the most relevant factor in explaining inter-annual variability in acorn production in both species. Considering that future climate scenarios predict progressive warmer and dryer spring seasons in the Mediterranean Basin, this might result in earlier onsets of flowering and higher water deficits that would constrain acorn production.

  18. Transport of airborne Picea schrenkiana pollen on the northern slope of Tianshan Mountains (Xinjiang, China) and its implication for paleoenvironmental reconstruction.

    PubMed

    Pan, Yanfang; Yan, Shun; Behling, Hermann; Mu, Guijin

    2013-06-01

    The understanding of airborne pollen transportation is crucial for the reconstruction of the paleoenvironment. Under favorable conditions, a considerable amount of long-distance-transported pollen can be deposited far from its place of origin. In extreme arid regions, in most cases, such situations occur and increase the difficulty to interpret fossil pollen records. In this study, three sets of Cour airborne pollen trap were installed on the northern slope of Tianshan Mountains to collect airborne Picea schrenkiana (spruce) pollen grains from July 2001 to July 2006. The results indicate that Picea pollen disperses extensively and transports widely in the lower atmosphere far away from spruce forest. The airborne Picea pollen dispersal period is mainly concentrated between mid-May and July. In desert area, weekly Picea pollen began to increase and peaked suddenly in concentration. Also, annual pollen indices do not decline even when the distance increased was probably related to the strong wind may pick up the deposited pollen grains from the topsoil into the air stream, leading to an increase of pollen concentration in the air that is irrelevant to the normal and natural course of pollen transport and deposition. This, in turn, may lead to erroneous interpretations of the pollen data in the arid region. This study provided insight into the shift in the Picea pollen season regarding climate change in arid areas. It is recorded that the pollen pollination period starts earlier and the duration became longer. The results also showed that the temperature of May and June was positively correlated with the Picea pollen production. Furthermore, the transport of airborne Picea pollen data is useful for interpreting fossil pollen records from extreme arid regions. PMID:23576840

  19. Disentangling the effects of feedback structure and climate on Poaceae annual airborne pollen fluctuations and the possible consequences of climate change.

    PubMed

    García de León, David; García-Mozo, Herminia; Galán, Carmen; Alcázar, Purificación; Lima, Mauricio; González-Andújar, José L

    2015-10-15

    Pollen allergies are the most common form of respiratory allergic disease in Europe. Most studies have emphasized the role of environmental processes, as the drivers of airborne pollen fluctuations, implicitly considering pollen production as a random walk. This work shows that internal self-regulating processes of the plants (negative feedback) should be included in pollen dynamic systems in order to give a better explanation of the observed pollen temporal patterns. This article proposes a novel methodological approach based on dynamic systems to investigate the interaction between feedback structure of plant populations and climate in shaping long-term airborne Poaceae pollen fluctuations and to quantify the effects of climate change on future airborne pollen concentrations. Long-term historical airborne Poaceae pollen data (30 years) from Cordoba city (Southern Spain) were analyzed. A set of models, combining feedback structure, temperature and actual evapotranspiration effects on airborne Poaceae pollen were built and compared, using a model selection approach. Our results highlight the importance of first-order negative feedback and mean annual maximum temperature in driving airborne Poaceae pollen dynamics. The best model was used to predict the effects of climate change under two standardized scenarios representing contrasting temporal patterns of economic development and CO2 emissions. Our results predict an increase in pollen levels in southern Spain by 2070 ranging from 28.5% to 44.3%. The findings from this study provide a greater understanding of airborne pollen dynamics and how climate change might impact the future evolution of airborne Poaceae pollen concentrations and thus the future evolution of related pollen allergies. PMID:26026414

  20. Long-term monitoring of airborne pollen in Alaska and the Yukon: Possible implications for global change

    SciTech Connect

    Anderson, J.H.

    1992-03-01

    Airborne pollen and spores have been sampled since 1978 in Fairbanks and 1982 Anchorage and other Alaska-Yukon locations for medical and ecological purposes. Comparative analyses of pre- and post-1986 data subsets reveal that after 1986 (1) pollen is in the air earlier, (2) the multiyear average of degree-days promoting pollen onset is little changed while (3) annual variation in degree-days at onset is greater, (4) pollen and spore annual productions are considerably higher, and (5) there is more year-to-year variation in pollen production. These changes probably reflect directional changes in certain weather variables, and there is some indication that they are of global change significance, i.e., related to increasing atmospheric greenhouse gases. Correlations with pollen data suggest that weather variables of high influence are temperatures during specific periods following pollen dispersal in the preceding year and the average temperature in April of the current year. Annual variations in pollen dispersal might be roughly linked to the 11 year sunspot cycle through air temperature mediators. Weather in 1990, apparent pollen production cycles under endogenous control, and the impending sunspot maximum portend a very severe pollen season in 199 existing but unfunded sampling projects.

  1. Airborne Pollen Concentrations and Emergency Room Visits for Myocardial Infarction: A Multicity Case-Crossover Study in Ontario, Canada.

    PubMed

    Weichenthal, Scott; Lavigne, Eric; Villeneuve, Paul J; Reeves, François

    2016-04-01

    Few studies have examined the acute cardiovascular effects of airborne allergens. We conducted a case-crossover study to evaluate the relationship between airborne allergen concentrations and emergency room visits for myocardial infarction (MI) in Ontario, Canada. In total, 17,960 cases of MI were identified between the months of April and October during the years 2004-2011. Daily mean aeroallergen concentrations (pollen and mold spores) were assigned to case and control periods using central-site monitors in each city along with daily measurements of meteorological data and air pollution (nitrogen dioxide and ozone). Odds ratios and their 95% confidence intervals were estimated using conditional logistic regression models adjusting for time-varying covariates. Risk of MI was 5.5% higher (95% confidence interval (CI): 3.4, 7.6) on days in the highest tertile of total pollen concentrations compared with days in the lowest tertile, and a significant concentration-response trend was observed (P < 0.001). Higher MI risk was limited to same-day pollen concentrations, with the largest risks being observed during May (odds ratio = 1.16, 95% CI: 1.00, 1.35) and June (odds ratio = 1.10, 95% CI: 1.00, 1.22), when tree and grass pollen are most common. Mold spore concentrations were not associated with MI. Our findings suggest that airborne pollen might represent a previously unidentified environmental risk factor for myocardial infarction. PMID:26934896

  2. Pollen spectrum and risk of pollen allergy in central Spain.

    PubMed

    Perez-Badia, Rosa; Rapp, Ana; Morales, Celia; Sardinero, Santiago; Galan, Carmen; Garcia-Mozo, Herminia

    2010-01-01

    The present work analyses the airborne pollen dynamic of the atmosphere of Toledo (central Spain), a World Heritage Site and an important tourist city receiving over 2 millions of visitors every year. The airborne pollen spectrum, the annual dynamics of the most important taxa, the influence of meteorological variables and the risk of suffering pollen allergy are analysed. Results of the present work are compared to those obtained by similar studies in nearby regions. The average annual Pollen Index is 44,632 grains, where 70-90 percent is recorded during February-May. The pollen calendar includes 29 pollen types, in order of importance; Cupressaceae (23.3 percent of the total amount of pollen grains), Quercus (21.2 percent), and Poaceae and Olea (11.5 and 11.2 percent, respectively), are the main pollen producer taxa. From an allergological viewpoint, Toledo is a high-risk locality for the residents and tourist who visit the area, with a great number of days exceeding the allergy thresholds proposed by the Spanish Aerobiological Network (REA). The types triggering most allergic processes in Toledo citizens and tourists are Cupressaceae, Platanus, Olea, Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Allergic risk increases in 3 main periods: winter (January-March), with the main presence of the Cupressaceae type; spring, characterized by Poaceae, Olea, Platanus and Urticaceae pollen types; and, finally, late summer (August-September), characterized by Chenopodiaceae- Amaranthaceae pollen type, which are the main cause of allergies during these months. PMID:20684492

  3. Influence of atmospheric ozone, PM 10 and meteorological factors on the concentration of airborne pollen and fungal spores

    NASA Astrophysics Data System (ADS)

    Sousa, S. I. V.; Martins, F. G.; Pereira, M. C.; Alvim-Ferraz, M. C. M.; Ribeiro, H.; Oliveira, M.; Abreu, I.

    The increase of allergenic symptoms has been associated with air contaminants such as ozone, particulate matter, pollen and fungal spores. Considering the potential relevance of crossed effects of non-biological pollutants and airborne pollens and fungal spores on allergy worsening, the aim of this work was to evaluate the influence of non-biological pollutants and meteorological parameters on the concentrations of pollen and fungal spores using linear correlations and multiple linear regressions. For that, the seasonal variation of ozone, particulate matter with an equivalent aerodynamic diameter smaller than 10 μm, pollen and fungal spores were assessed and statistical correlations were analysed between those parameters. The data were collected through 2003-2005 in Porto, Portugal. The linear correlations showed that ozone and particulate matter had no significant influence on the concentration of pollen and fungal spores. On the contrary, when using multiple linear regressions those parameters showed to have some influence on the biological pollutants, although results were different depending on the year analysed. Among the meteorological parameters analysed, temperature was the one that most influenced the pollen and fungal spores airborne concentrations, both when using linear and multiple linear correlations. Relative humidity also showed to have some influence on the fungal spore dispersion when multiple linear regressions were used. Nevertheless, the conclusions for each pollen and fungal spore were different depending on the analysed period, which means that the correlations identified as statistically significant may not be, even so, consistent enough. Furthermore, the comparison of the results here presented with those obtained by other authors for only one period should be made carefully.

  4. The long distance transport of airborne Ambrosia pollen to the UK and the Netherlands from Central and south Europe

    NASA Astrophysics Data System (ADS)

    de Weger, Letty A.; Pashley, Catherine H.; Šikoparija, Branko; Skjøth, Carsten A.; Kasprzyk, Idalia; Grewling, Łukasz; Thibaudon, Michel; Magyar, Donat; Smith, Matt

    2016-04-01

    The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport. Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectory and atmospheric dispersion calculations were performed using HYSPLIT_4. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses (1500 m) originated from source areas on the Pannonian Plain and Ukraine. During the episode, air masses veered to the west and passed over the Rhône Valley. Dispersion calculations showed that the atmospheric conditions were suitable for Ambrosia pollen released from the Pannonian Plain and the Rhône Valley to reach the higher levels and enter the airstream moving to northwest Europe where they were deposited at ground level and recorded by monitoring sites. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rhône Valley in France.

  5. Airborne-pollen pool and mating pattern in a hybrid zone between Pinus pumila and P. parviflora var. pentaphylla.

    PubMed

    Ito, Megumi; Suyama, Yoshihisa; Ohsawa, Takeshi A; Watano, Yasuyuki

    2008-12-01

    The reproductive isolation barriers and the mating patterns among Pinus pumila, P. parviflora var. pentaphylla and their hybrids were examined by flowering phenology and genetic assays of three life stages: airborne-pollen grains, adults and seeds, in a hybrid zone on Mount Apoi, Hokkaido, Japan. Chloroplast DNA composition of the airborne-pollen was determined by single-pollen polymerase chain reaction. Mating patterns were analysed by estimating the molecular hybrid index of the seed parent, their seed embryos and pollen parents. The observation of flowering phenology showed that the flowering of P. pumila precedes that of P. parviflora var. pentaphylla by about 6 to 10 days within the same altitudinal ranges. Although this prezygotic isolation barrier is effective, the genetic assay of airborne-pollen showed that the two pine species, particularly P. pumila, still have chances to form F(1) hybrid seeds. Both parental species showed a strong assortative mating pattern; F(1) seeds were found in only 1.4% of seeds from P. pumila mother trees and not at all in P. parviflora var. pentaphylla. The assortative mating was concluded as the combined result of flowering time differentiation and cross-incompatibility. In contrast to the parental species, hybrids were fertilized evenly by the two parental species and themselves. The breakdown of prezygotic barriers (intermediate flowering phenology) and cross-incompatibility may account for the unselective mating. It is suggested that introgression is ongoing on Mount Apoi through backcrossing between hybrids and parental species, despite strong isolation barriers between the parental species. PMID:19120991

  6. Association between first airborne cedar pollen level peak and pollinosis symptom onset: a web-based survey.

    PubMed

    Bando, Harumi; Sugiura, Hiroaki; Ohkusa, Yasushi; Akahane, Manabu; Sano, Tomomi; Jojima, Noriko; Okabe, Nobuhiko; Imamura, Tomoaki

    2015-01-01

    Cedar pollinosis in Japan affects nearly 25 % of Japanese citizens. To develop a treatment for cedar pollinosis, it is necessary to understand the relationship between the time of its occurrence and the amount of airborne cedar pollen. In the spring of 2009, we conducted daily Internet-based epidemiologic surveys, which included 1453 individuals. We examined the relationship between initial date of onset of pollinosis symptoms and daily amount of airborne cedar pollen to which subjects were exposed. Approximately 35.2 % of the subjects experienced the onset of pollinosis during a one-week interval in which the middle day coincided with the peak pollen count. The odds ratio for this one-week time interval was 4.03 (95 % confidence interval: 3.34-4.86). The predicted date of the cedar pollen peak can be used to determine the appropriate date for initiation of self-medication with anti-allergy drugs and thus avoid development of sustained and severe pollinosis. PMID:24720339

  7. Weather elements, chemical air pollutants and airborne pollen influencing asthma emergency room visits in Szeged, Hungary: performance of two objective weather classifications

    NASA Astrophysics Data System (ADS)

    Makra, László; Puskás, János; Matyasovszky, István; Csépe, Zoltán; Lelovics, Enikő; Bálint, Beatrix; Tusnády, Gábor

    2015-09-01

    Weather classification approaches may be useful tools in modelling the occurrence of respiratory diseases. The aim of the study is to compare the performance of an objectively defined weather classification and the Spatial Synoptic Classification (SSC) in classifying emergency department (ED) visits for acute asthma depending from weather, air pollutants, and airborne pollen variables for Szeged, Hungary, for the 9-year period 1999-2007. The research is performed for three different pollen-related periods of the year and the annual data set. According to age and gender, nine patient categories, eight meteorological variables, seven chemical air pollutants, and two pollen categories were used. In general, partly dry and cold air and partly warm and humid air aggravate substantially the symptoms of asthmatics. Our major findings are consistent with this establishment. Namely, for the objectively defined weather types favourable conditions for asthma ER visits occur when an anticyclonic ridge weather situation happens with near extreme temperature and humidity parameters. Accordingly, the SSC weather types facilitate aggravating asthmatic conditions if warm or cool weather occur with high humidity in both cases. Favourable conditions for asthma attacks are confirmed in the extreme seasons when atmospheric stability contributes to enrichment of air pollutants. The total efficiency of the two classification approaches is similar in spite of the fact that the methodology for derivation of the individual types within the two classification approaches is completely different.

  8. Weather elements, chemical air pollutants and airborne pollen influencing asthma emergency room visits in Szeged, Hungary: performance of two objective weather classifications.

    PubMed

    Makra, László; Puskás, János; Matyasovszky, István; Csépe, Zoltán; Lelovics, Enikő; Bálint, Beatrix; Tusnády, Gábor

    2015-09-01

    Weather classification approaches may be useful tools in modelling the occurrence of respiratory diseases. The aim of the study is to compare the performance of an objectively defined weather classification and the Spatial Synoptic Classification (SSC) in classifying emergency department (ED) visits for acute asthma depending from weather, air pollutants, and airborne pollen variables for Szeged, Hungary, for the 9-year period 1999-2007. The research is performed for three different pollen-related periods of the year and the annual data set. According to age and gender, nine patient categories, eight meteorological variables, seven chemical air pollutants, and two pollen categories were used. In general, partly dry and cold air and partly warm and humid air aggravate substantially the symptoms of asthmatics. Our major findings are consistent with this establishment. Namely, for the objectively defined weather types favourable conditions for asthma ER visits occur when an anticyclonic ridge weather situation happens with near extreme temperature and humidity parameters. Accordingly, the SSC weather types facilitate aggravating asthmatic conditions if warm or cool weather occur with high humidity in both cases. Favourable conditions for asthma attacks are confirmed in the extreme seasons when atmospheric stability contributes to enrichment of air pollutants. The total efficiency of the two classification approaches is similar in spite of the fact that the methodology for derivation of the individual types within the two classification approaches is completely different. PMID:25504051

  9. Bayesian analysis of climate change effects on observed and projected airborne levels of birch pollen

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Isukapalli, Sastry S.; Bielory, Leonard; Georgopoulos, Panos G.

    2013-04-01

    A Bayesian framework is presented for modeling effects of climate change on pollen indices such as annual birch pollen count, maximum daily birch pollen count, start date of birch pollen season and the date of maximum daily birch pollen count. Annual mean CO2 concentration, mean spring temperature and the corresponding pollen index of prior year were found to be statistically significant accounting for effects of climate change on four pollen indices. Results suggest that annual productions and peak values from 2020 to 2100 under different scenarios will be 1.3-8.0 and 1.1-7.3 times higher respectively than the mean values for 2000, and start and peak dates will occur around two to four weeks earlier. These results have been partly confirmed by the available historical data. As a demonstration, the emission profiles in future years were generated by incorporating the predicted pollen indices into an existing emission model.

  10. Bayesian Analysis of Climate Change Effects on Observed and Projected Airborne Levels of Birch Pollen.

    PubMed

    Zhang, Yong; Isukapalli, Sastry; Bielory, Leonard; Georgopoulos, Panos

    2013-04-01

    A Bayesian framework is presented for modeling Effects of climate change on pollen indices such as annual birch pollen count, maximum daily birch pollen count, start date of birch pollen season and the date of maximum daily birch pollen count. Annual mean CO2 concentration, mean spring temperature and the corresponding pollen index of prior year were found to be statistically significant accounting for Effects of climate change on four pollen indices. Results suggest that annual productions and peak values from 2020 to 2100 under different scenarios will be 1.3-8.0 and 1.1-7.3 times higher respectively than the mean values for 2000, and start and peak dates will occur around two to four weeks earlier. These results have been partly confirmed by the available historical data. As a demonstration, the emission profiles in future years were generated by incorporating the predicted pollen indices into an existing emission model. PMID:23526049

  11. Bayesian Analysis of Climate Change Effects on Observed and Projected Airborne Levels of Birch Pollen

    PubMed Central

    Zhang, Yong; Isukapalli, Sastry; Bielory, Leonard; Georgopoulos, Panos

    2012-01-01

    A Bayesian framework is presented for modeling Effects of climate change on pollen indices such as annual birch pollen count, maximum daily birch pollen count, start date of birch pollen season and the date of maximum daily birch pollen count. Annual mean CO2 concentration, mean spring temperature and the corresponding pollen index of prior year were found to be statistically significant accounting for Effects of climate change on four pollen indices. Results suggest that annual productions and peak values from 2020 to 2100 under different scenarios will be 1.3-8.0 and 1.1-7.3 times higher respectively than the mean values for 2000, and start and peak dates will occur around two to four weeks earlier. These results have been partly confirmed by the available historical data. As a demonstration, the emission profiles in future years were generated by incorporating the predicted pollen indices into an existing emission model. PMID:23526049

  12. Airborne pollen-climate relationship based on discriminant analysis in Nam Co, Central Tibet and its palaeoenvironmental significance

    NASA Astrophysics Data System (ADS)

    Lyu, X.; Zhu, L.; Ma, Q.; Li, Q.

    2014-12-01

    Based on the airborne pollen data collected using a Burkard pollen trap, discriminant analysis were conducted to evaluate the relationship between two different atmospheric circulation systems, the Asia summer monsoon (ASM) and the Westerlies, in Nam Co basin, central Tibet. The whole year's samples could be classified into two groups using cluster analysis: one group was from May to September, another group was from October to April of next year, corresponding to monsoon period and non-monsoon period, respectively. The classification represents two different atmospheric circulation systems, ASM in monsoon period and the Westerlies in non-monsoon period. Discriminant analysis was performed. First, the whole year samples were divided into two a priori groups, group A is monsoon period (May-Sep.) and group B is non-monsoon period (Oct.-Apr.). Then percentage data of major pollen taxa were used to establish the discriminant functions, and then the samples were classified into predicted groups. The results of discriminant analysis show that 78.6% of the samples were cross-validated grouped correctly. Thus, airborne pollen assemblages can distinguish two different climate systems: monsoon period and non-monsoon period. According to the discriminant score, the group centroids of group A and group B were negative and positive, respectively. Therefore, we created the discriminant score as a new monsoon index (PDI, Pollen Discriminant Index), small PDI values represented enhanced summer monsoon climate. Using above result, we calculated the PDI of Nam Co NCL core, the PDI values can be coincided with Dryness (moisture indicator) and A/Cy ratio (temperature indicator).

  13. Diurnal variations of airborne pollen concentration and the effect of ambient temperature in three sites of Mexico City.

    PubMed

    Ríos, B; Torres-Jardón, R; Ramírez-Arriaga, E; Martínez-Bernal, A; Rosas, I

    2016-05-01

    Pollen is an important cause of allergic respiratory ailments in the Mexico City Metropolitan Area (MCMA). However, very little is known if ambient air temperature correlates with the early blooming of plants observed in other urban areas around the world. A research study was conducted during the dry season of 2012-2013 at three representative sites of the MCMA with different urban characteristics with the aim to understand the relationships between the profusion and diversity of pollen against temperature and other meteorological variables and degree of urbanization. Pollen samples were collected using a Hirst-type trap sampler in the sites: Merced (highly urbanized), Iztapalapa (medium-high urbanized) and Coyoacan (moderately urbanized). Urbanization levels were determined using a composite index based on population density, proportion of surface covered by construction and asphalt, and urban heat island intensity. A set of representative pollen sampling tapes were assayed under a light microscope at magnification of ×1,000 and converted to grains per cubic meter. The most representative pollen types found in the three sites were, regardless of urbanization levels were: Fraxinus, Cupressaceae/Taxodiaceae, Casuarina, Alnus, Myrtaceae, and Pinus. Total pollen concentration was greatest in the moderately urbanized area, although earlier blooming took place at the highly urbanized zone. Total pollen concentration in the medium-high urbanized site has the lowest because the green areas in this zone of MCMA are few. In a diurnal basis, the most abundant pollen types peaked near midday or in the afternoon evening at the three sites. A Spearman test showed a positive correlation among bihourly pollen concentrations, temperature and relative humidity in all sites, but wind speed just correlated in Iztapalapa and Coyoacan. The results obtained suggest that Urban Heat Island Intensity can disturb flowering periods and pollen concentrations, largely in the highly urbanized

  14. Diurnal variations of airborne pollen concentration and the effect of ambient temperature in three sites of Mexico City

    NASA Astrophysics Data System (ADS)

    Ríos, B.; Torres-Jardón, R.; Ramírez-Arriaga, E.; Martínez-Bernal, A.; Rosas, I.

    2016-05-01

    Pollen is an important cause of allergic respiratory ailments in the Mexico City Metropolitan Area (MCMA). However, very little is known if ambient air temperature correlates with the early blooming of plants observed in other urban areas around the world. A research study was conducted during the dry season of 2012-2013 at three representative sites of the MCMA with different urban characteristics with the aim to understand the relationships between the profusion and diversity of pollen against temperature and other meteorological variables and degree of urbanization. Pollen samples were collected using a Hirst-type trap sampler in the sites: Merced (highly urbanized), Iztapalapa (medium-high urbanized) and Coyoacan (moderately urbanized). Urbanization levels were determined using a composite index based on population density, proportion of surface covered by construction and asphalt, and urban heat island intensity. A set of representative pollen sampling tapes were assayed under a light microscope at magnification of ×1,000 and converted to grains per cubic meter. The most representative pollen types found in the three sites were, regardless of urbanization levels were: Fraxinus, Cupressaceae/Taxodiaceae, Casuarina, Alnus, Myrtaceae, and Pinus. Total pollen concentration was greatest in the moderately urbanized area, although earlier blooming took place at the highly urbanized zone. Total pollen concentration in the medium-high urbanized site has the lowest because the green areas in this zone of MCMA are few. In a diurnal basis, the most abundant pollen types peaked near midday or in the afternoon evening at the three sites. A Spearman test showed a positive correlation among bihourly pollen concentrations, temperature and relative humidity in all sites, but wind speed just correlated in Iztapalapa and Coyoacan. The results obtained suggest that Urban Heat Island Intensity can disturb flowering periods and pollen concentrations, largely in the highly urbanized

  15. Airborne pollen assemblages and weather regime in the central-eastern Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Li, Yuecong; Ge, Yawen; Xu, Qinghai; Bunting, Jane M.; Lv, Suqing; Wang, Junting; Li, Zetao

    2015-04-01

    This paper presents the results of pollen trapping studies designed to quantify the pollen assemblages carried in the winds of the Loess Plateau in Luochuan and Hunyuan. The one-year-collection samples analysis results show that pollen assemblages can be more sensitive to the change of climate than the vegetation composition, because of the change of pollen production. The analysis results of pollen traps in different weather regimes indicate that the pollen influx coming from dust weather contribute more to the total pollen influx than that coming from non-dust weather. The wind speed is the most important influenced factor to pollen assemblages, then the mean temperature and the mean relative humidity, the wind direction also contributes some. Strong wind coming from dust direction can make the percent and influx of Artemisia and Chenopodiaceae increase obviously with averagely higher than over 2.7 times in dust weather than in non-dust samples. The influences of wind speed and wind direction are not serious to some arboreal pollen such as Rosaceae, Quercus, Betula, Pinus and Ostryopsis, which are mainly influenced by temperature or the relative humidity such as Salix, Hippophae, Carpinus, Brassicaceae, Cupressaceae, Fabaceae.

  16. Seasonal appearance of grass pollen allergen in natural, pauci-micronic aerosol of various size fractions. Relationship with airborne grass pollen concentration.

    PubMed

    Spieksma, F T; Nikkels, B H; Dijkman, J H

    1995-03-01

    In a study during the 1993 grass pollen season at Leiden, the relationship between atmospheric pollen allergen carried by five size fractions of pauci-micronic (few microns) particles and the grass pollen count was investigated. Sampling was carried out on dry days, and atmospheric pollen allergen in the particle fractions was assessed by a RAST-inhibition assay while grass pollen quantities were measured with a volumetric pollen trap. It appears that the atmospheric presence of grass pollen allergen in all size fractions is restricted mainly to the period of presence of grass pollen grains. Before and after the grass pollen season atmospheric grass pollen allergen quantities are generally very low. It is concluded that a routinely performed grass pollen count is a reliable measurement for the estimation of the amount of atmospheric grass pollen allergen, also in the pauci-micronic particle fraction. PMID:7788570

  17. Particulate matter modifies the association between airborne pollen and daily medical consultations for pollinosis in Tokyo.

    PubMed

    Konishi, Shoko; Ng, Chris Fook Sheng; Stickley, Andrew; Nishihata, Shinichi; Shinsugi, Chisa; Ueda, Kayo; Takami, Akinori; Watanabe, Chiho

    2014-11-15

    Pollen from Japanese cedar (sugi) and cypress (hinoki) trees is responsible for the growing prevalence of allergic rhinitis, especially pollinosis in Japan. Previous studies have suggested that air pollutants enhance the allergic response to pollen in susceptible individuals. We conducted a time-stratified case-crossover study to examine the potential modifying effects of PM2.5 and suspended particulate matter (SPM) on the association between pollen concentration and daily consultations for pollinosis. A total of 11,713 daily pollinosis cases (International Classification of Diseases, ICD-10, J30.1) from January to May, 2001-2011, were obtained from a clinic in Chiyoda, Tokyo. Daily pollen counts and the daily mean values of air pollutants (PM2.5, SPM, SO2, NO2, CO, and O3) were collected from monitoring stations across Tokyo. The effects of pollen were stratified by the level of PM2.5 and SPM to examine the interaction effect of pollen and particulate pollutants. We found a statistically significant interaction between pollen concentration and PM2.5/SPM. On days with a high level of PM2.5 (>95th percentile), an interquartile increase in the mean cumulative pollen count (an average of 28 pollen grains per cm(2) during lag-days 0 to 5) corresponded to a 10.30% (95%CI: 8.48%-12.16%) increase in daily new pollinosis cases, compared to 8.04% (95%CI: 7.28%-8.81%) on days with a moderate level of PM2.5 (5th-95th percentile). This interaction persisted when different percentile cut-offs were used and was robust to the inclusion of other air pollutants. A similar interaction pattern was observed between SPM and pollen when a less extreme cut-off for SPM was used to stratify the effect of pollen. Our study showed the acute effect of pollen was greater when the concentration of air particulate pollutant, specifically PM2.5 and SPM, was higher. These findings are consistent with the notion that particulate air pollution may act as an adjuvant that promotes allergic disease (i

  18. Poaceae pollen in Galicia (N.W. Spain): characterisation and recent trends in atmospheric pollen season.

    PubMed

    Jato, V; Rodríguez-Rajo, F J; Seijo, M C; Aira, M J

    2009-07-01

    Airborne Poaceae pollen counts are greatly influenced by weather-related parameters, but may also be governed by other factors. Poaceae pollen is responsible for most allergic reactions in the pollen-sensitive population of Galicia (Spain), and it is therefore essential to determine the risk posed by airborne pollen counts. The global climate change recorded over recent years may prompt changes in the atmospheric pollen season (APS). This survey used airborne Poaceae pollen data recorded for four Galician cities since 1993, in order to characterise the APS and note any trends in its onset, length and severity. Pollen sampling was performed using Hirst-type volumetric traps; data were subjected to Spearman's correlation test and regression models, in order to detect possible correlations between different parameters and trends. The APS was calculated using ten different methods, in order to assess the influence of each on survey results. Finally, trends detected for the major weather-related parameters influencing pollen counts over the study period were compared with those recorded over the last 30 years. All four cities displayed a trend towards lower annual total Poaceae pollen counts, lower peak values and a smaller number of days on which counts exceeded 30, 50 and 100 pollen grains/m(3). Moreover, the survey noted a trend towards delayed onset and shorter duration of the APS, although differences were observed depending on the criteria used to define the first and the last day of the APS. PMID:19347372

  19. Poaceae pollen in Galicia (N.W. Spain): characterisation and recent trends in atmospheric pollen season

    NASA Astrophysics Data System (ADS)

    Jato, V.; Rodríguez-Rajo, F. J.; Seijo, M. C.; Aira, M. J.

    2009-07-01

    Airborne Poaceae pollen counts are greatly influenced by weather-related parameters, but may also be governed by other factors. Poaceae pollen is responsible for most allergic reactions in the pollen-sensitive population of Galicia (Spain), and it is therefore essential to determine the risk posed by airborne pollen counts. The global climate change recorded over recent years may prompt changes in the atmospheric pollen season (APS). This survey used airborne Poaceae pollen data recorded for four Galician cities since 1993, in order to characterise the APS and note any trends in its onset, length and severity. Pollen sampling was performed using Hirst-type volumetric traps; data were subjected to Spearman’s correlation test and regression models, in order to detect possible correlations between different parameters and trends. The APS was calculated using ten different methods, in order to assess the influence of each on survey results. Finally, trends detected for the major weather-related parameters influencing pollen counts over the study period were compared with those recorded over the last 30 years. All four cities displayed a trend towards lower annual total Poaceae pollen counts, lower peak values and a smaller number of days on which counts exceeded 30, 50 and 100 pollen grains/m3. Moreover, the survey noted a trend towards delayed onset and shorter duration of the APS, although differences were observed depending on the criteria used to define the first and the last day of the APS.

  20. Variations in mugwort (Artemisia spp.) airborne pollen concentrations at three sites in central Croatia, in period from 2002 to 2003.

    PubMed

    Peternel, Renata; Hrga, Ivana; Culig, Josip

    2006-12-01

    In spite of the low atmospheric pollen levels, Artemisia sensitisation and allergy has been reported widely. The aim of the study was to determine the length of pollen season, intradiurnal, daily and monthly pollen variation, and the effect of some meteorological parameters on atmospheric pollen concentrations in Central Croatia. Seven-day Hirst volumetric pollen and spore traps were used for pollen sampling. The Artemisia pollen season lasted from the end of July until the end of September with the highest concentrations in August. The percentage of the total pollen count ranged from 0.52% to 0.92%. The intradiurnal peak occurred between 10 a.m. and 12 a.m. Statistical analysis showed a significant correlations between higher air temperature and high pollen concentration as well as high precipitation and low pollen concentration. Results of this study are expected to help in preventing the symptoms of allergic reaction in individuals with Artemisia pollen hypersensitivity. PMID:17243566

  1. Impact and correlation of environmental conditions on pollen counts in Karachi, Pakistan.

    PubMed

    Perveen, Anjum; Khan, Muneeba; Zeb, Shaista; Imam, Asif Ali

    2015-02-01

    A quantitative and qualitative survey of airborne pollen was performed in the city of Karachi, and the pollen counts were correlated with different climatic conditions. The aim of the study was to determine the possible effect of meteorological factors on airborne pollen distribution in the atmosphere of Karachi city. Pollen sampling was carried out by using Burkard spore Trap for the period of August 2009 to July 2010, and a total of 2,922 pollen grains/m(3) were recorded. In this survey, 22 pollen types were recognized. The highest pollen count was contributed by Poaceae pollen type (1,242 pollen grains/m(3)) followed by Amaranthaceae/Chenopodiaceae (948 pollen grains/m(3)), Cyperus rotundus (195 pollen grains/m(3)) and Prosopis juliflora (169 pollen grains/m(3)). Peak pollen season was in August showing a total of 709 pollen grains/m(3) and lowest pollen count was observed in January-2010. Pearson's chi-square test was performed for the possible correlation of pollen counts and climatic factors. The test revealed significant positive correlation of wind speed with pollen types of Amaranthaceae/Chenopodiaceae; Brassica campestris; Asteraceae; and Thuja orientalis. While the correlation of "average temperature" showed significant positive value with Asteraceae and Tamarix indica pollen types. Negative correlation was observed between humidity/ precipitation and pollen types of Brassica campestris; Daucus carota; Ephedra sp.; and Tamarix indica. In the light of above updated data one could identify various aeroallergens present in the air of Karachi city. PMID:25530143

  2. An unusual appearance of a common pollen type indicates the scene of the crime.

    PubMed

    Mildenhall, D C

    2006-11-22

    Forensic palynology is a useful source of evidence in cases of violence committed in the open. A young girl was grabbed off the street, threatened and brutally raped. During the investigation the exact place of the rape became an issue. Growing around the scene identified by the victim were shrubs identified as Coprosma, a common New Zealand plant and one that produces abundant, easily wind-dispersed pollen. Abundant Coprosma pollen was found at the scene. The pollen were unusual in that the site was very damp, encouraging fungal growth, and fungal hyphae had penetrated the pores of many of the tricolporate pollen grains. Some grains had fungal spores inside. Coprosma pollen identical in preservational characteristics and morphology to those from the scene and containing fungal hyphae and spores were found in considerable numbers on the victim's clothes. This and rare Coprosma pollen grains and fungal remains recovered from vaginal swabs provided evidence that she had been at the scene where she claimed to have been raped. The diversity of pollen types recovered from the clothing in this case provides further evidence of the usefulness of clothing in picking up and retaining pollen from crime scenes and that obvious staining on clothes is not a pre-requisite for good pollen recovery. It also demonstrates the importance of collecting samples from different parts of the same garment in order to get a full picture of events since different parts of a garment can come into contact with different plants or different parts of the ground in a scuffle. It is also demonstrated that significant evidential material can be collected from the body, in this case from vaginal swabs from the victim. Forensic palynology should be considered in every case of violent assault, especially, but not exclusively, when having occurred in an open area subject to extensive pollen settlement. PMID:16406423

  3. Utility of surface pollen assemblages to delimit Eastern Eurasian steppe types.

    PubMed

    Qin, Feng; Wang, Yu-Fei; Ferguson, David K; Chen, Wen-Li; Li, Ya-Meng; Cai, Zhe; Wang, Qing; Ma, Hong-Zhen; Li, Cheng-Sen

    2015-01-01

    Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an ecological humidity gradient. The multivariate ordination of the pollen data indicated that Eurasian steppe types could be clearly differentiated. The different steppe types could be distinguished primarily by xerophilous elements in the pollen assemblages. Redundancy analysis indicated that the relative abundances of Ephedra, Tamarix, Nitraria and Zygophyllaceae were positively correlated with aridity. The relative abundances of Ephedra increased from meadow steppe to typical steppe and desert steppe. Tamarix and Zygophyllaceae were found in both typical steppe and desert steppe, but not in meadow steppe. Nitraria was only found in desert steppe. The relative abundances of xerophilous elements were greater in desert steppe than in typical steppe. These findings indicate that Eurasian steppe types can be differentiated based on recent pollen rain. PMID:25763576

  4. Utility of Surface Pollen Assemblages to Delimit Eastern Eurasian Steppe Types

    PubMed Central

    Qin, Feng; Wang, Yu-Fei; Ferguson, David K.; Chen, Wen-Li; Li, Ya-Meng; Cai, Zhe; Wang, Qing; Ma, Hong-Zhen; Li, Cheng-Sen

    2015-01-01

    Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an ecological humidity gradient. The multivariate ordination of the pollen data indicated that Eurasian steppe types could be clearly differentiated. The different steppe types could be distinguished primarily by xerophilous elements in the pollen assemblages. Redundancy analysis indicated that the relative abundances of Ephedra, Tamarix, Nitraria and Zygophyllaceae were positively correlated with aridity. The relative abundances of Ephedra increased from meadow steppe to typical steppe and desert steppe. Tamarix and Zygophyllaceae were found in both typical steppe and desert steppe, but not in meadow steppe. Nitraria was only found in desert steppe. The relative abundances of xerophilous elements were greater in desert steppe than in typical steppe. These findings indicate that Eurasian steppe types can be differentiated based on recent pollen rain. PMID:25763576

  5. Airborne pollen sampling in Manoa Valley, Hawaii: effect of rain, humidity and wind.

    PubMed

    Massey, D G; Fournier-Massey, G

    1984-05-01

    Kramer-Collins pollen sampling was conducted over 24 hours for 25 consecutive months at two valley sites in Honolulu. Of 1,059 expected samples, 699 (66.0%) were collected. Only 25 were considered excellent, i.e., eight three-hour collection bands. Twenty eight were considered good, ie., two to six bands. The difficulties in the study were associated with the weather directly (17.5%), the power source (3.9%), inadequancy of the samplers (63.1%) and the inexperience of technicians (15.3%). Sampler problems were also indirectly attributable to the high humidity, rain and wind, which differed at the two sites. PMID:6721258

  6. Cytochemical Analysis of Pollen Development in Wild-Type Arabidopsis and a Male-Sterile Mutant.

    PubMed Central

    Regan, SM; Moffatt, BA

    1990-01-01

    Microsporogenesis has been examined in wild-type Arabidopsis thaliana and the nuclear male-sterile mutant BM3 by cytochemical staining. The mutant lacks adenine phosphoribosyltransferase, an enzyme of the purine salvage pathway that converts adenine to AMP. Pollen development in the mutant began to diverge from wild type just after meiosis, as the tetrads of microspores were released from their callose walls. The first indication of abnormal pollen development in the mutant was a darker staining of the microspore wall due to an incomplete synthesis of the intine. Vacuole formation was delayed and irregular in the mutant, and the majority of the mutant microspores failed to undergo mitotic divisions. Enzyme activities of alcohol dehydrogenase and esterases decreased in the mutant soon after meiosis and were undetectable in mature pollen grains of the mutant. RNA accumulation was also diminished. These results are discussed in relation to the possible role(s) of adenine salvage in pollen development. PMID:12354970

  7. Bee Pollen

    MedlinePlus

    ... Don’t confuse bee pollen with bee venom, honey, or royal jelly. People take bee pollen for ... Pollen, Extrait de Pollen d’Abeille, Honeybee Pollen, Honey Bee Pollen, Maize Pollen, Pine Pollen, Polen de ...

  8. Allergies, asthma, and pollen

    MedlinePlus

    Allergic rhinitis - pollen ... them is your first step toward feeling better. Pollen is a trigger for many people who have allergies and asthma. The types of pollens that are triggers vary from person to person ...

  9. Biochemical and immunological studies on eight pollen types from South Assam, India.

    PubMed

    Sharma, Dhruba; Dutta, B K; Singh, A B

    2009-12-01

    A total of 65 pollen types were identified from two years atmospheric pollen survey in the environmental conditions of South Assam. Out of them, eight pollen types viz., Acacia auriculiformis, Amaranthus spinosus, Cassia alata, Cleome gynandra, Cocos nucifera, Imperata cylindrica, Ricinus communis and Trewia nudiflora, were selected for biochemical studies on the basis of their dominance in the study sites. Among the sample extract tested, Ricinus communis was found to contain the highest amount of soluble protein, free amino acid and total carbohydrate, per gram of dry weight followed by Imperata cylindrica and Cassia alata. Maximum numbers of protein polypeptide bands were detected in the sample extract of Cassia alata by polyacrylamide gel electrophoresis method followed by Acacia auriculiformis, Imperata cylindrica and Cocos nucifera. IgE binding protein fractions were maximum in Cassia alata and minimum in Trewia nudiflora. PMID:20404388

  10. Atmospheric pollen season in Zagreb (Croatia) and its relationship with temperature and precipitation.

    PubMed

    Peternel, Renata; Srnec, Lidija; Culig, Josip; Zaninović, Ksenija; Mitić, Bozena; Vukusić, Ivan

    2004-05-01

    The number of individuals allergic to plant pollen has recently been on a constant increase, especially in large cities and industrial areas. Therefore, monitoring of airborne pollen types and concentrations during the pollen season is of the utmost medical importance. The research reported in this paper aims to determine the beginning, course and end of the pollen season for the plants in the City of Zagreb, to identify allergenic plants, and to assess the variation in airborne pollen concentration as a function of temperature and precipitation changes for the year 2002. A volumetric Hirst sampler was used for airborne pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). In the Zagreb area, 12 groups of highly allergenic plants (alder, hazel, cypress, birch, ash, hornbeam, grasses, elder, nettles, sweet chestnut, artemisia and ambrosia) were identified. Birch pollen predominated in spring, the highest concentrations being recorded in February and March. Grass pollen prevailed in May and June, and pollen of herbaceous plants of the genus Urtica (nettle) and of ambrosia in July, August and September. Air temperature was mostly higher or considerably higher than the annual average in those months, which resulted in a many days with high and very high airborne pollen concentrations. The exception was April, when these concentrations were lower because of high levels of precipitation. This also held for the first half of August and the second half of September. Pollen-sensitive individuals were at high risk from February till October because of the high airborne pollen concentrations, which only showed a transient decrease when the temperature fell or there was precipitation. PMID:14770305

  11. Atmospheric pollen season in Zagreb (Croatia) and its relationship with temperature and precipitation

    NASA Astrophysics Data System (ADS)

    Peternel, Renata; Srnec, Lidija; Čulig, Josip; Zaninović, Ksenija; Mitić, Božena; Vukušić, Ivan

    . The number of individuals allergic to plant pollen has recently been on a constant increase, especially in large cities and industrial areas. Therefore, monitoring of airborne pollen types and concentrations during the pollen season is of the utmost medical importance. The research reported in this paper aims to determine the beginning, course and end of the pollen season for the plants in the City of Zagreb, to identify allergenic plants, and to assess the variation in airborne pollen concentration as a function of temperature and precipitation changes for the year 2002. A volumetric Hirst sampler was used for airborne pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification ×400). In the Zagreb area, 12 groups of highly allergenic plants (alder, hazel, cypress, birch, ash, hornbeam, grasses, elder, nettles, sweet chestnut, artemisia and ambrosia) were identified. Birch pollen predominated in spring, the highest concentrations being recorded in February and March. Grass pollen prevailed in May and June, and pollen of herbaceous plants of the genus Urtica (nettle) and of ambrosia in July, August and September. Air temperature was mostly higher or considerably higher than the annual average in those months, which resulted in a many days with high and very high airborne pollen concentrations. The exception was April, when these concentrations were lower because of high levels of precipitation. This also held for the first half of August and the second half of September. Pollen-sensitive individuals were at high risk from February till October because of the high airborne pollen concentrations, which only showed a transient decrease when the temperature fell or there was precipitation.

  12. First Evidence for Wollemi Pine-type Pollen (Dilwynites: Araucariaceae) in South America

    PubMed Central

    Macphail, Mike; Carpenter, Raymond J.; Iglesias, Ari; Wilf, Peter

    2013-01-01

    We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America. PMID:23894439

  13. First evidence for Wollemi Pine-type pollen (Dilwynites: Araucariaceae) in South America.

    PubMed

    Macphail, Mike; Carpenter, Raymond J; Iglesias, Ari; Wilf, Peter

    2013-01-01

    We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America. PMID:23894439

  14. Intradiurnal variations of allergenic tree pollen in the atmosphere of Toledo (central Spain).

    PubMed

    Pérez-Badia, Rosa; Vaquero, Consolación; Sardinero, Santiago; Galán, Carmen; García-Mozo, Herminia

    2010-01-01

    To study the impact of inhaling airborne pollen on health, it is important to know not only their average daily concentrations but also the intradiurnal behaviour of these biological particles. This study reports the bi-hourly distribution of the arboreal airborne pollen types more abundant in the atmosphere of Toledo (central Spain), many of them triggering important allergic processes in Toledo citizens and tourist visitors. Knowledge of bi-hourly pattern atmospheric variation pollen may help pollinosis patients to adopt preventive measures and plan their outdoor activities accordingly. Intradiurnal variation has been studied for the arboreal pollen types: Cupressaceae, Fraxinus, Olea, Platanus, Populus, Quercus and Ulmus, during the period 2005-2008. The main hourly pollen concentrations were observed during sunlight hours and the maximum pollen values obtained at midday and in the afternoon, except for pollen types Quercus and Platanus, whose maximum pollen concentrations were obtained during the night. The statistical analyses performed to compare pollen concentration and main hourly meteorological variables proved to be significant for most of the taxa. The results show a significant and positive effect of temperature, solar radiation and wind speed on the daily variability undergone by atmospheric pollen. Relative humidity influenced in a negative way on the intradiurnal variation of pollen in the atmosphere of Toledo. PMID:21186770

  15. An objective classification system of air mass types for Szeged, Hungary, with special attention to plant pollen levels.

    PubMed

    Makra, László; Juhász, Miklós; Mika, János; Bartzokas, Aristides; Béczi, Rita; Sümeghy, Zoltán

    2006-07-01

    This paper discusses the characteristic air mass types over the Carpathian Basin in relation to plant pollen levels over annual pollination periods. Based on the European Centre for Medium-Range Weather Forecasts dataset, daily sea-level pressure fields analysed at 00 UTC were prepared for each air mass type (cluster) in order to relate sea-level pressure patterns to pollen levels in Szeged, Hungary. The database comprises daily values of 12 meteorological parameters and daily pollen concentrations of 24 species for their pollination periods from 1997 to 2001. Characteristic air mass types were objectively defined via factor analysis and cluster analysis. According to the results, nine air mass types (clusters) were detected for pollination periods of the year corresponding to pollen levels that appear with higher concentration when irradiance is moderate while wind speed is moderate or high. This is the case when an anticyclone prevails in the region west of the Carpathian Basin and when Hungary is under the influence of zonal currents (wind speed is high). The sea level pressure systems associated with low pollen concentrations are mostly similar to those connected to higher pollen concentrations, and arise when wind speed is low or moderate. Low pollen levels occur when an anticyclone prevails in the region west of the Carpathian Basin, as well as when an anticyclone covers the region with Hungary at its centre. Hence, anticyclonic or anticyclonic ridge weather situations seem to be relevant in classifying pollen levels. PMID:16575583

  16. Regional forecast model for the Olea pollen season in Extremadura (SW Spain)

    NASA Astrophysics Data System (ADS)

    Fernández-Rodríguez, Santiago; Durán-Barroso, Pablo; Silva-Palacios, Inmaculada; Tormo-Molina, Rafael; Maya-Manzano, José María; Gonzalo-Garijo, Ángela

    2016-02-01

    The olive tree (Olea europaea) is a predominantly Mediterranean anemophilous species. The pollen allergens from this tree are an important cause of allergic problems. Olea pollen may be relevant in relation to climate change, due to the fact that its flowering phenology is related to meteorological parameters. This study aims to investigate airborne Olea pollen data from a city on the SW Iberian Peninsula, to analyse the trends in these data and their relationships with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1994 to 2013 in Badajoz (SW Spain) using a 7-day Hirst-type volumetric sampler. The main Olea pollen season lasted an average of 34 days, from May 4th to June 7th. The model proposed to forecast airborne pollen concentrations, described by one equation. This expression is composed of two terms: the first term represents the resilience of the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term was obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological variables multiplied by a fitting coefficient. Due to the allergenic characteristics of this pollen type, it should be necessary to forecast its short-term prevalence using a long record of data in a city with a Mediterranean climate. The model obtained provides a suitable level of confidence to forecast Olea airborne pollen concentration.

  17. Separating morphologically similar pollen types using basic shape features from digital images: A preliminary study1

    PubMed Central

    Holt, Katherine A.; Bebbington, Mark S.

    2014-01-01

    • Premise of the study: One of the many advantages offered by automated palynology systems is the ability to vastly increase the number of observations made on a particular sample or samples. This is of particular benefit when attempting to fully quantify the degree of variation within or between closely related pollen types. • Methods: An automated palynology system (Classifynder) has been used to further investigate the variation in pollen morphology between two New Zealand species of Myrtaceae (Leptospermum scoparium and Kunzea ericoides) that are of significance in the New Zealand honey industry. Seven geometric features extracted from automatically gathered digital images were used to characterize the range of shape and size of the two taxa, and to examine the extent of previously reported overlap in these variables. • Results: Our results indicate a degree of overlap in all cases. The narrowest overlap was in measurements of maximum Feret diameter (MFD) in grains oriented in polar view. Multivariate statistical analysis using all seven factors provided the most robust discrimination between the two types. • Discussion: Further work is required before this approach could be routinely applied to separating the two pollen types used in this study, most notably the development of comprehensive reference distributions for the types in question. PMID:25202650

  18. Modeling olive pollen intensity in the Mediterranean region through analysis of emission sources.

    PubMed

    Rojo, J; Orlandi, F; Pérez-Badia, R; Aguilera, F; Ben Dhiab, A; Bouziane, H; Díaz de la Guardia, C; Galán, C; Gutiérrez-Bustillo, A M; Moreno-Grau, S; Msallem, M; Trigo, M M; Fornaciari, M

    2016-05-01

    Aerobiological monitoring of Olea europaea L. is of great interest in the Mediterranean basin because olive pollen is one of the most represented pollen types of the airborne spectrum for the Mediterranean region, and olive pollen is considered one of the major cause of pollinosis in this region. The main aim of this study was to develop an airborne-pollen map based on the Pollen Index across a 4-year period (2008-2011), to provide a continuous geographic map for pollen intensity that will have practical applications from the agronomical and allergological points of view. For this purpose, the main predictor variable was an index based on the distribution and abundance of potential sources of pollen emission, including intrinsic information about the general atmospheric patterns of pollen dispersal. In addition, meteorological variables were included in the modeling, together with spatial interpolation, to allow the definition of a spatial model of the Pollen Index from the main olive cultivation areas in the Mediterranean region. The results show marked differences with respect to the dispersal patterns associated to the altitudinal gradient. The findings indicate that areas located at an altitude above 300ma.s.l. receive greater amounts of olive pollen from shorter-distance pollen sources (maximum influence, 27km) with respect to areas lower than 300ma.s.l. (maximum influence, 59km). PMID:26874763

  19. Incidence of Betulaceae pollen and pollinosis in Zagreb, Croatia, 2002-2005.

    PubMed

    Peternel, Renata; Milanović, Sanja Musić; Hrga, Ivana; Mileta, Tatjana; Culig, Josip

    2007-01-01

    Pollen allergy is characterized by seasonal allergic manifestations affecting patients during the plant pollen season. The aim of this study was to analyze the Betulaceae pollen pattern in Zagreb (2002-2005) and to determine the incidence of sensitization to these pollen types in patients with seasonal respiratory allergy. Twenty-four-hour pollen counts were carried out using volumetric procedure. Skin prick test were performed on a total of 864 patients aged 18-80< in Zagreb between 2 January-31 December 2004. Pollen of the representatives of the family Betulaceae accounted for a significant proportion of total pollen (34% on an average), predominated by Betula pollen and considerably lower proportion of Alnus sp. and Corylus sp. pollen. Alder and hazel pollen first occurred in the air in February throughout the study period. The highest airborne pollen concentration of these taxa was recorded in February and March. The birch pollen season generally peaked in April. Only 2.67% of patients showed birch pollen monosensitization. The proportion of patients with polysensitization to Betulaceae pollen was considerably greater (12.88%), whereas polysensitization to Betulaceae, Poaceae and Ambrosia pollen was recorded in the highest proportion of patients (26.23%). According to age, the highest and lowest rate of allergy was recorded in the 31-50 and >51 age groups, respectively (46.22% vs 23.12%). Female predominance was observed across all age groups. The patients with monosensitization to birch pollen had the most severe symptoms in April. In the patients with poylsensitization to alder, hazel and birch pollen who developed cross-reaction, initial symptoms occurred as early as February, with abrupt exacerbation in March and April. The most severe condition was observed in the patients allergic to birch, hazel, alder, grass and ragweed pollen, with symptoms present throughout the year and exacerbation in spring and late summer months. PMID:17655183

  20. Dating Fossil Pollen: A Simulation.

    ERIC Educational Resources Information Center

    Sheridan, Philip

    1992-01-01

    Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

  1. Allergenic pollen and pollen allergy in Europe.

    PubMed

    D'Amato, G; Cecchi, L; Bonini, S; Nunes, C; Annesi-Maesano, I; Behrendt, H; Liccardi, G; Popov, T; van Cauwenberge, P

    2007-09-01

    The allergenic content of the atmosphere varies according to climate, geography and vegetation. Data on the presence and prevalence of allergenic airborne pollens, obtained from both aerobiological studies and allergological investigations, make it possible to design pollen calendars with the approximate flowering period of the plants in the sampling area. In this way, even though pollen production and dispersal from year to year depend on the patterns of preseason weather and on the conditions prevailing at the time of anthesis, it is usually possible to forecast the chances of encountering high atmospheric allergenic pollen concentrations in different areas. Aerobiological and allergological studies show that the pollen map of Europe is changing also as a result of cultural factors (for example, importation of plants such as birch and cypress for urban parklands), greater international travel (e.g. colonization by ragweed in France, northern Italy, Austria, Hungary etc.) and climate change. In this regard, the higher frequency of weather extremes, like thunderstorms, and increasing episodes of long range transport of allergenic pollen represent new challenges for researchers. Furthermore, in the last few years, experimental data on pollen and subpollen-particles structure, the pathogenetic role of pollen and the interaction between pollen and air pollutants, gave new insights into the mechanisms of respiratory allergic diseases. PMID:17521313

  2. An ABCG/WBC-type ABC transporter is essential for transport of sporopollenin precursors for exine formation in developing pollen.

    PubMed

    Choi, Hyunju; Jin, Jun-Young; Choi, Setbyoul; Hwang, Jae-Ung; Kim, Yu-Young; Suh, Mi Chung; Lee, Youngsook

    2011-01-01

    The exine of the pollen wall shows an intricate pattern, primarily comprising sporopollenin, a polymer of fatty acids and phenolic compounds. A series of enzymes synthesize sporopollenin precursors in tapetal cells, and the precursors are transported from the tapetum to the pollen surface. However, the mechanisms underlying the transport of sporopollenin precursors remain elusive. Here, we provide evidence that strongly suggests that the Arabidopsis ABC transporter ABCG26/WBC27 is involved in the transport of sporopollenin precursors. Two independent mutations at ABCG26 coding region caused drastic decrease in seed production. This defect was complemented by expression of ABCG26 driven by its native promoter. The severely reduced fertility of the abcg26 mutants was caused by a failure to produce mature pollen, observed initially as a defect in pollen-wall development. The reticulate pattern of the exine of wild-type microspores was absent in abcg26 microspores at the vacuolate stage, and the vast majority of the mutant pollen degenerated thereafter. ABCG26 was expressed specifically in tapetal cells at the early vacuolate stage of pollen development. It showed high co-expression with genes encoding enzymes required for sporopollenin precursor synthesis, i.e. CYP704B1, ACOS5, MS2 and CYP703A2. Similar to two other mutants with defects in pollen-wall deposition, abcg26 tapetal cells accumulated numerous vesicles and granules. Taken together, these results suggest that ABCG26 plays a crucial role in the transfer of sporopollenin lipid precursors from tapetal cells to anther locules, facilitating exine formation on the pollen surface. PMID:21223384

  3. Pollen-based quantitative reconstructions of Holocene regional vegetation cover (plant-functional types and land-cover types) in Europe suitable for climate modelling.

    PubMed

    Trondman, A-K; Gaillard, M-J; Mazier, F; Sugita, S; Fyfe, R; Nielsen, A B; Twiddle, C; Barratt, P; Birks, H J B; Bjune, A E; Björkman, L; Broström, A; Caseldine, C; David, R; Dodson, J; Dörfler, W; Fischer, E; van Geel, B; Giesecke, T; Hultberg, T; Kalnina, L; Kangur, M; van der Knaap, P; Koff, T; Kuneš, P; Lagerås, P; Latałowa, M; Lechterbeck, J; Leroyer, C; Leydet, M; Lindbladh, M; Marquer, L; Mitchell, F J G; Odgaard, B V; Peglar, S M; Persson, T; Poska, A; Rösch, M; Seppä, H; Veski, S; Wick, L

    2015-02-01

    We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1° × 1° spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS model was applied on 636 pollen records from lakes and bogs to reconstruct the past cover of 25 plant taxa grouped into 10 plant-functional types and three land-cover types [evergreen trees, summer-green (deciduous) trees, and open land]. The model corrects for some of the biases in pollen percentages by using pollen productivity estimates and fall speeds of pollen, and by applying simple but robust models of pollen dispersal and deposition. The emerging patterns of tree migration and deforestation between 6k bp and modern time in the REVEALS estimates agree with our general understanding of the vegetation history of Europe based on pollen percentages. However, the degree of anthropogenic deforestation (i.e. cover of cultivated and grazing land) at 3k, 0.5k, and 0.2k bp is significantly higher than deduced from pollen percentages. This is also the case at 6k in some parts of Europe, in particular Britain and Ireland. Furthermore, the relationship between summer-green and evergreen trees, and between individual tree taxa, differs significantly when expressed as pollen percentages or as REVEALS estimates of tree cover. For instance, when Pinus is dominant over Picea as pollen percentages, Picea is dominant over Pinus as REVEALS estimates. These differences play a major role in the reconstruction of European landscapes and for the study of land cover-climate interactions, biodiversity and human resources. PMID:25204435

  4. Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands)

    NASA Astrophysics Data System (ADS)

    Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia

    2011-01-01

    The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees ( Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs ( Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea

  5. Heterogeneity in ragweed pollen exposure is determined by plant composition at small spatial scales.

    PubMed

    Katz, Daniel S W; Carey, Tiffany S

    2014-07-01

    Pollen allergies are one of the most common health problems in the United States and over 20% of Americans are sensitized to the pollen produced by common ragweed (Ambrosia artemisiifolia L.). Despite the importance of allergenic pollen to public health, no research has linked land use and plant populations to spatial heterogeneity in airborne pollen concentrations. In order to quantify these relationships and elucidate the processes which lead to pollen exposure, we surveyed ragweed stem density in Detroit (Michigan, USA) as a function of land use. We then deployed 34 pollen collectors throughout the city and recorded ragweed cover in the immediate vicinity of each pollen collector. We found that ragweed populations were highest in vacant lots, a common land cover type in Detroit. Because ragweed population density was so strongly correlated to vacant lots, for which spatially explicit data were available, we were able to investigate whether observed ragweed pollen concentrations were a function of land use at the spatial scales of 10 m and 1 km. Both relationships were significant, and the combination of these two variables predicts a large portion of airborne ragweed pollen concentrations (R(2)=0.48). These results emphasize the important role of pollen production within the urban environment and show that management of allergenic pollen producing plants must be considered at multiple spatial scales. Our findings also demonstrate that there is too much spatial heterogeneity for a pollen collector at any given site to portray the allergenic pollen load experienced by different individuals within the same city. Finally, we discuss how spatial correlations between socio-economic status, vacant lots, and ragweed could help to explain the disproportionate amount of allergies and ragweed sensitization experienced by low income and minority populations in Detroit. PMID:24742553

  6. Pollen and seed flow patterns of Carapa guianensis Aublet. (Meliaceae) in two types of Amazonian forest

    PubMed Central

    Martins, Karina; Raposo, Andréa; Klimas, Christie A.; Veasey, Elizabeth A.; Kainer, Karen; Wadt, Lúcia Helena O.

    2012-01-01

    Various factors affect spatial genetic structure in plant populations, including adult density and primary and secondary seed dispersal mechanisms. We evaluated pollen and seed dispersal distances and spatial genetic structure of Carapa guianensis Aublet. (Meliaceae) in occasionally inundated and terra firme forest environments that differed in tree densities and secondary seed dispersal agents. We used parentage analysis to obtain contemporary gene flow estimates and assessed the spatial genetic structure of adults and juveniles. Despite the higher density of adults (diameter at breast height ≥ 25 cm) and spatial aggregation in occasionally inundated forest, the average pollen dispersal distance was similar in both types of forest (195 ± 106 m in terra firme and 175 ± 87 m in occasionally inundated plots). Higher seed flow rates (36.7% of juveniles were from outside the plot) and distances (155 ± 84 m) were found in terra firme compared to the occasionally inundated plot (25.4% and 114 ± 69 m). There was a weak spatial genetic structure in juveniles and in terra firme adults. These results indicate that inundation may not have had a significant role in seed dispersal in the occasionally inundated plot, probably because of the higher levels of seedling mortality. PMID:23271944

  7. Central African biomes and forest succession stages derived from modern pollen data and plant functional types

    NASA Astrophysics Data System (ADS)

    Lebamba, J.; Ngomanda, A.; Vincens, A.; Jolly, D.; Favier, C.; Elenga, H.; Bentaleb, I.

    2009-07-01

    New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo) including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs) and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1) modern potential biomes and (2) potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites) and tropical rain forest (TRFO biome) is well identified from tropical seasonal forest (TSFO biome). When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe) evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map should be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO) is well differentiated from the secondary forest (TSFE), but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

  8. Definition of main pollen season using a logistic model.

    PubMed

    Ribeiro, Helena; Cunha, Mário; Abreu, Ilda

    2007-01-01

    This paper proposes a method to unify the definition of the main pollen season based on statistical analysis. For this, an aerobiological study was carried out in Porto region (Portugal), from 2003-2005 using a 7-day Hirst-type volumetric spore trap. To define the main pollen season, a non-linear logistic regression model was fitted to the values of the accumulated sum of the daily airborne pollen concentration from several allergological species. An important feature of this method is that the main pollen season will be characterized by the model parameters calculated. These parameters are identifiable aspects of the flowering phenology, and determine not only the beginning and end of the main pollen season, but are also influenced by the meteorological conditions. The results obtained with the proposed methodology were also compared with two of the most used percentage methods. The logistic model fitted well with the sum of accumulated pollen. The explained variance was always higher than 97%, and the exponential part of the predicted curve was well adjusted to the time when higher atmospheric pollen concentration was sampled. The comparison between the different methods tested showed large divergence in the duration and end dates of the main pollen season of the studied species. PMID:18247462

  9. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    NASA Astrophysics Data System (ADS)

    Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo; Hialine Working Group

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network). Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient. Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration. Although Bet v 1 is a mixture of different

  10. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    NASA Astrophysics Data System (ADS)

    The HIALINE working Group; Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network).Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient.Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration.Although Bet v 1 is a mixture of different

  11. Types of Pollen Dispersal Units in Orchids, and their Consequences for Germination and Fertilization

    PubMed Central

    Pacini, Ettore; Hesse, Michael

    2002-01-01

    The various pollen dispersal units (PDU) found in orchids are discussed together with possible evolutionary trends and the consequences for germination and fertilization. Orchids with monad and tetrad pollen form more complex dispersal units by means of pollenkitt, elastoviscin, a callosic wall, common walls or a combination of these. Evolutionary trends include (1) from pollenkitt to elastoviscin; (2) from monad to tetrads and multiples of tetrads; (3) from partially dehydrated (<30 %) to partially hydrated (>30 %) pollen; and (4) from monad pollen to PDUs with many pollen grains. The biological consequences concern both male and female reproductive systems. Some features of the male side are present in all orchids irrespective of the pollen dispersal unit, whereas other characters are found only in orchids with pollinia; the same applies for the female counterpart. Pollen grains of orchids with pollinia germinate at least 24 h after pollination because the pollen grains/tetrads must swell and make space for the growth of pollen tubes. PMID:12102520

  12. Integration of Airborne Aerosol Prediction Systems and Vegetation Phenology to Track Pollen for Asthma Alerts in Public Health Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey C.; Sprigg, William A.; Huete, Alfredo; Pejanovic, Goran; Nickovic,Slobodan; Ponce-Campos, Guillermo; Krapfl, Heide; Budge, Amy; Zelicoff, Alan; VandeWater, Peter K.; Levetin, Estelle; Crimmins, Theresa; Weltzin, Jake

    2011-01-01

    This slide presentation reviews the study that used a model to forecast pollen to assist in warning for asthma populations. Using MODIS daily reflectances to input to a model, PREAM, adapted from the Dust REgional Atmospheric Modeling (DREAM) system, a product of predicted pollen is produced. Using the pollen from Juniper the PREAM model was shown to be an assist in alerting the public of pollen bursts, and reduce the health impact on asthma populations.

  13. A Six-Year Study on the Changes in Airborne Pollen Counts and Skin Positivity Rates in Korea: 2008–2013

    PubMed Central

    Park, Hye Jung; Lee, Jae-Hyun; Park, Kyung Hee; Kim, Kyu Rang; Han, Mae Ja; Choe, Hosoeng

    2016-01-01

    Purpose The occurrence of pollen allergy is subject to exposure to pollen, which shows regional and temporal variations. We evaluated the changes in pollen counts and skin positivity rates for 6 years, and explored the correlation between their annual rates of change. Materials and Methods We assessed the number of pollen grains collected in Seoul, and retrospectively reviewed the results of 4442 skin-prick tests conducted at the Severance Hospital Allergy-Asthma Clinic from January 1, 2008 to December 31, 2013. Results For 6 years, the mean monthly total pollen count showed two peaks, one in May and the other in September. Pollen count for grasses also showed the same trend. The pollen counts for trees, grasses, and weeds changed annually, but the changes were not significant. The annual skin positivity rates in response to pollen from grasses and weeds increased significantly over the 6 years. Among trees, the skin positivity rates in response to pollen from walnut, popular, elm, and alder significantly increased over the 6 years. Further, there was a significant correlation between the annual rate of change in pollen count and the rate of change in skin positivity rate for oak and hop Japanese. Conclusion The pollen counts and skin positivity rates should be monitored, as they have changed annually. Oak and hop Japanese, which showed a significant correlation with the annual rate of change in pollen count and the rate of change in skin positivity rate over the 6 years may be considered the major allergens in Korea. PMID:26996572

  14. The Effect of Pollinator Type and Plant Spatial Structure on Patterns of Pollen-Mediated Gene Dispersal in Aquilegia Coerulea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Question/Methods - Direct estimation of pollen dispersal distances from paternity type analyses is often not possible. Therefore, recent emphasis have been on the development of indirect methods relying on the assumed decay with spatial distance in a measure of the genetic structure of p...

  15. Pollen and microsporangium development in Hovenia dulcis (Rhamnaceae): a different type of tapetal cell ultrastructure.

    PubMed

    Gotelli, Marina M; Galati, Beatriz G; Zarlavsky, Gabriela; Medan, Diego

    2016-07-01

    Despite that there is some literature on pollen morphology of Rhamnaceae, studies addressing general aspects of the microsporogenesis, microgametogenesis, and anther development are rare. The aim of this paper is to describe the ultrastructure of pollen grain ontogeny with special attention to tapetum cytology in Hovenia dulcis. Anthers at different stages of development were processed for transmission and scanning electron microscopy, bright-field microscopy, and fluorescence microscopy. Different histochemical reactions were carried out. The ultrastructural changes observed during the development of the tapetal cells and pollen grains are described. Large vesicles containing carbohydrates occur in the tapetal cell cytoplasm during the early stages of pollen development. Its origin and composition are described and discussed. This is the first report on the ontogeny and ultrastructure of the pollen grain and related sporophytic structures of H. dulcis. PMID:26277353

  16. Comparison of modern pollen distribution between the northern and southern parts of the South China Sea

    NASA Astrophysics Data System (ADS)

    Luo, Chuanxiu; Chen, Muhong; Xiang, Rong; Liu, Jianguo; Zhang, Lanlan; Lu, Jun

    2015-04-01

    The authors conducted a palynological analysis based on different number of air pollen samples for the northern and southern parts of the South China Sea, respectively, in order to give a reference to reconstruct the paleoclimate of the area. (1) Fifteen air pollen samples were collected from the northern part of the South China Sea from August to September 2011, and 13 air pollen samples were collected from the southern part of the South China Sea in December 2011. The pollen types were more abundant in the north than in the south. The total pollen number and concentration in the north was 10 times more than that in the south, which may be because of the sampling season. Airborne pollen types and concentrations have a close relationship with wind direction and distance from the sampling point to the continent. (2) Seventy-four samples were collected from surface sediments in the northern part of the South China Sea in the autumn. Thirty-three samples were collected from surface sediments in the southern part of the South China Sea in the winter. Pollen concentrations in the north were nearly 10 times higher than that in the south. This is because trilete spores are transported by rivers from Hainan Island to the sea and also by the summer monsoon-forced marine current. (3) Ten air pollen samples and 10 surface sediments samples were selected for comparison. The pollen and spores in the air were mainly herbaceous and woody pollen, excluding fern spores, having seasonal pollen characteristics. Pollen in the surface sediments were mainly trilete, Pinus, and herbaceous, and may also show a combination of annual pollen characteristics.

  17. Integration of Airborne Aerosol Prediction Systems and Vegetation Phenology to Track Pollen for Asthma Alerts in Public Health Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey C.; Sprigg, William A.; Huete, Alfredo; Pejanovic, Goran; Nickovic, Slobodan; Krapfl, Heide; Budge, Amy; Zelicoff, Alan; VandeWater, Peter K.; Levetin, Estelle; Losleben, Mark; Weltzin, Jake

    2009-01-01

    The residual signal indicates that the pollen event may influence the seasonal signal to an extent that would allow detection, given accurate QA filtering and BRDF corrections. MODIS daily reflectances increased during the pollen season. The DREAM model (PREAM) was successfully modified for use with pollen and may provide 24-36 hour running pollen forecasts. Publicly available pollen forecasts are linked to general weather patterns and roughly-known species phenologies. These are too coarse for timely health interventions. PREAM addresses this key data gap so that targeting intervention measures can be determined temporally and geospatially. The New Mexico Department of Health (NMDOH) as part of its Environmental Public Health Tracking Network (EPHTN) would use PREAM a tool for alerting the public in advance of pollen bursts to intervene and reduce the health impact on asthma populations at risk.

  18. Stable isotope ratios of carbon and nitrogen in pollen grains in order to characterize plant functional groups and photosynthetic pathway types.

    PubMed

    Descolas-Gros, Chantal; Schölzel, Christian

    2007-01-01

    Measurements of delta(13)C, delta(15)N and C : N ratios on modern pollen grains from temperate plants, including whole grains as well as extracted sporopollenin, were analysed in order to characterize physiological plant types at the pollen level and to determine the variation of these parameters in modern pollen grains of the same climatic area. Measurements are presented for 95 batches of whole modern pollen from 58 temperate species and on the stable fraction of modern pollen grains, chemically extracted sporopollenin, for two modern species. Fourier transform infrared (FTIR) and cross-polarization and magic-angle spinning (CP/MAS) sporopollenin spectra were conducted in parallel. C(3) and C(4) plants can be separated by delta(13)C measurements based on pollen. Probabilistic assignments to plant functional groups (herbaceous, deciduous woody, evergreen woody) of C(3) plants by the means of a discriminant analysis can be made for C : N ratios and for delta(13)C. The results are related to other studies on sporopollenin in order to use this method in future work on fossil samples. Stable isotope measurements on pollen allow improved pollen diagrams, including forms that cannot be differentiated at species level, increasing the accuracy and resolution of plant physiological type distribution in quaternary and older fossil sediments. PMID:17888118

  19. Effect of air temperature on forecasting the start of Cupressaceae pollen type in Ponferrada (Leon, Spain).

    PubMed

    Fuertes-Rodríguez, Carmen Reyes; González-Parrado, Zulima; Vega-Maray, Ana María; Valencia-Barrera, Rosa María; Fernández-González, Delia

    2007-01-01

    In order to survive periods of adverse cold climatic conditions, plant requirements are satisfied by means of physiological adaptations to prevent cells from freezing. Thus, the growth of woody plants in temperate regions slows down and they enter into a physiological state called dormancy. In order to identify the chilling and heat requirements to overcome the dormancy period of Cupressaceae pollen type in the south of Europe, we have carried out our study with aerobiological data from a 10-year (1996-2005) period in Ponferrada, León (Spain). For the chilling requirements the best result was with a threshold temperature of 7.1 degrees C and an average of 927 CH. Calculation of heat requirements was carried out with maximum temperature, with 490 growth degree days (GDD) needed, with a threshold temperature of 0 degrees C. We have used the 2002-2003, 2003-2004 and 2004-2005 periods in order to determine the real validity of the model. We have not used these years in developing the models. The dates predicted differ in only a few days from those observed: in 2002-2003 there was a difference of 11 days, in 2003-2004 predicted and observed dates were the same, but in 2004-2005 the difference obtained was of 43 days. PMID:18247458

  20. Integration for Airborne Dust Prediction Systems and Vegetation Phenology to Track Pollen for Asthma Alerts in Public Health Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Luvall, J. C.; Sprigg, W. A.; Nickovic, S.; Huete, A.; Budge, A.; Flowers, L.

    2008-01-01

    The objective of the program is to assess the feasibility of combining a dust transport model with MODIS derived phenology to study pollen transport for integration with a public health decision support system. The use of pollen information has specifically be identified as a critical need by the New Mexico State Health department for inclusion in the Environmental Public Health Tracking (EPHT) program. Material and methods: Pollen can be transported great distances. Local observations of plan phenology may be consistent with the timing and source of pollen collected by pollen sampling instruments. The Dust REgional Atmospheric Model (DREAM) is an integrated modeling system designed to accurately describe the dust cycle in the atmosphere. The dust modules of the entire system incorporate the state of the art parameterization of all the major phases of the atmospheric dust life such as production, diffusion, advection, and removal. These modules also include effects of the particles size distribution on aerosol dispersion. The model was modified to use pollen sources instead of dust. Pollen release was estimated based on satellite-derived phenology of key plan species and vegetation communities. The MODIS surface reflectance product (MOD09) provided information on the start of the plant growing season, growth stage, and pollen release. The resulting deterministic model is useful for predicting and simulating pollen emission and downwind concentration to study details of phenology and meteorology and their dependencies. The proposed linkage in this project provided critical information on the location timing and modeled transport of pollen directly to the EPHT> This information is useful to support the centers for disease control and prevention (CDC)'s National EPHT and the state of New Mexico environmental public health decision support for asthma and allergies alerts.

  1. MISR BRF measurements for various surface types: Intercomparison with coincident airborne and ground measurements.

    NASA Astrophysics Data System (ADS)

    Abdou, W. A.; Helmlinger, M.; Jovanovic, V. M.; Martonchik, J. V.; Diner, D. J.; Gatebe, C. K.; King, M. D.

    2005-05-01

    The BRF retrieved by the multiangle Imaging spectroRadimeter (MISR) are compared with those coincidently measured from aircraft, by the Cloud Absorption Radiometer (CAR) and MISR airborne simulator (AirMISR), and on the ground, by the Portable Apparatus for Rabid Acquisition of Bidirectional Observations of Land and Atmosphere (PARABOLA III). The intercomparisons are made for five types of surfaces: bright desert, salt pans, dark grassland, forests and dismal swamps. The results show that MISR BRF values are within +/- 10% in agreement with the corresponding airborne and ground measurements, independent of the surface type. This study is part of an effort to validate MISR surface products.

  2. All-optical automatic pollen identification: Towards an operational system

    NASA Astrophysics Data System (ADS)

    Crouzy, Benoît; Stella, Michelle; Konzelmann, Thomas; Calpini, Bertrand; Clot, Bernard

    2016-09-01

    We present results from the development and validation campaign of an optical pollen monitoring method based on time-resolved scattering and fluorescence. Focus is first set on supervised learning algorithms for pollen-taxa identification and on the determination of aerosol properties (particle size and shape). The identification capability provides a basis for a pre-operational automatic pollen season monitoring performed in parallel to manual reference measurements (Hirst-type volumetric samplers). Airborne concentrations obtained from the automatic system are compatible with those from the manual method regarding total pollen and the automatic device provides real-time data reliably (one week interruption over five months). In addition, although the calibration dataset still needs to be completed, we are able to follow the grass pollen season. The high sampling from the automatic device allows to go beyond the commonly-presented daily values and we obtain statistically significant hourly concentrations. Finally, we discuss remaining challenges for obtaining an operational automatic monitoring system and how the generic validation environment developed for the present campaign could be used for further tests of automatic pollen monitoring devices.

  3. AIRBORNE-CONTACT DERMATITIS OF NON-PLANT ORIGIN: AN OVERVIEW

    PubMed Central

    Ghosh, Sanjay

    2011-01-01

    Airborne-contact dermatitis (ABCD) represents a unique type of contact dermatitis originating from dust, sprays, pollens or volatile chemicals by airborne fumes or particles without directly touching the allergen. ABCD in Indian patients has been attributed exclusively by pollens of the plants like Parthenium hysterophorus, etc., but in recent years the above scenario has been changing rapidly in urban and semiurban perspective especially in developing countries. ABCD has been reported worldwide due to various type of nonplant allergens and their clinical feature are sometimes distinctive. Preventive aspect has been attempted by introduction of different chemicals of less allergic potential. PMID:22345776

  4. Pollen Primer

    MedlinePlus

    ... air filters (HEPA) or an electrostatic air filter. Tree Pollen Trees produce pollen earliest, as soon as January in ... distributed miles away. Fewer than 100 kinds of trees cause allergies. Some common ones are catalpa, elm, ...

  5. Pollen Allergy

    MedlinePlus

    ... pollen count, which is often reported by local weather broadcasts or allergy websites, is a measure of how much pollen is in the air. Pollen counts tend to be highest early in the morning on warm, dry, breezy days and lowest during chilly, wet periods. ...

  6. Aerobiological study in east-central Iberian Peninsula: pollen diversity and dynamics for major taxa.

    PubMed

    Pérez-Badia, Rosa; Rapp, Ana; Vaquero, Consolación; Fernández-González, Federico

    2011-01-01

    A study was made of airborne pollen counts in Cuenca (east-central Iberian Peninsula, Spain), using data obtained over a 3-year period (2008-2010). This is the first such study carried out in the World Heritage city of Cuenca, situated in the large region of Castilla-La Mancha. Air monitoring was performed using the sampling and analysis procedures recommended by the Spanish Aerobiology Network. Sampling commenced in mid- 2007, and provided the first recorded pollen-spectrum for the area. The greatest pollen-type diversity was recorded in spring, whilst the highest pollen counts (over 80 percent of the annual total) were observed between February and June. The lowest counts were found in September, November and December. The 10 leading taxa, in order of abundance, were: Cupressaceae, Quercus, Urticaceae, Pinus, Olea, Poaceae, Populus, Platanus, Chenopodiaceae-Amaranthaceae and Plantago. The pollen calendar was thus typically Mediterrean, and comprised the 27 pollen types reaching 10-day mean counts of over 1 grain/m(3) of air. Maximum concentration values during the day were recorded between 12:00-20:00, coinciding with the highest temperatures and lowest humidity levels. The pollen types responsible for most allergies in the city of Cuenca, ordered by the number of days on which risk levels were reached, were: Poaceae, Urticaceae, Cupressaceae, Olea, Platanus and Chenopodiaceae-Amaranthaceae. PMID:21736275

  7. Spatial variability of oceanic phycoerythrin spectral types derived from airborne laser-induced fluorescence emissions

    NASA Astrophysics Data System (ADS)

    Hoge, Frank E.; Wright, C. Wayne; Kana, Todd M.; Swift, Robert N.; Yungel, James K.

    1998-07-01

    We report spatial variability of oceanic phycoerythrin spectral types detected by means of a blue spectral shift in airborne laser-induced fluorescence emission. The blue shift of the phycoerythrobilin fluorescence is known from laboratory studies to be induced by phycourobilin chromophore substitution at phycoerythrobilin chromophore sites in some strains of phycoerythrin-containing marine cyanobacteria. The airborne 532-nm laser-induced phycoerythrin fluorescence of the upper oceanic volume showed distinct segregation of cyanobacterial chromophore types in a flight transect from coastal water to the Sargasso Sea in the western North Atlantic. High phycourobilin levels were restricted to the oceanic (oligotrophic) end of the flight transect, in agreement with historical ship findings. These remotely observed phycoerythrin spectral fluorescence shifts have the potential to permit rapid, wide-area studies of the spatial variability of spectrally distinct cyanobacteria, especially across interfacial regions of coastal and oceanic water masses. Airborne laser-induced phytoplankton spectral fluorescence observations also further the development of satellite algorithms for passive detection of phytoplankton pigments. Optical modifications to the NASA Airborne Oceanographic Lidar are briefly described that permitted observation of the fluorescence spectral shifts.

  8. Classification of Airborne Laser Scanning Data Using Geometric Multi-Scale Features and Different Neighbourhood Types

    NASA Astrophysics Data System (ADS)

    Blomley, R.; Jutzi, B.; Weinmann, M.

    2016-06-01

    In this paper, we address the classification of airborne laser scanning data. We present a novel methodology relying on the use of complementary types of geometric features extracted from multiple local neighbourhoods of different scale and type. To demonstrate the performance of our methodology, we present results of a detailed evaluation on a standard benchmark dataset and we show that the consideration of multi-scale, multi-type neighbourhoods as the basis for feature extraction leads to improved classification results in comparison to single-scale neighbourhoods as well as in comparison to multi-scale neighbourhoods of the same type.

  9. Cluster analysis of intradiurnal holm oak pollen cycles at peri-urban and rural sampling sites in southwestern Spain

    NASA Astrophysics Data System (ADS)

    Hernández-Ceballos, M. A.; García-Mozo, H.; Galán, C.

    2015-08-01

    The impact of regional and local weather and of local topography on intradiurnal variations in airborne pollen levels was assessed by analysing bi-hourly holm oak ( Quercus ilex subsp. ballota (Desf.) Samp.) pollen counts at two sampling stations located 40 km apart, in southwestern Spain (Cordoba city and El Cabril nature reserve) over the period 2010-2011. Pollen grains were captured using Hirst-type volumetric spore traps. Analysis of regional weather conditions was based on the computation of backward trajectories using the HYSPLIT model. Sampling days were selected on the basis of phenological data; rainy days were eliminated, as were days lying outside a given range of percentiles (P95-P5). Analysis of cycles for the study period, as a whole, revealed differences between sampling sites, with peak bi-hourly pollen counts at night in Cordoba and at midday in El Cabril. Differences were also noted in the influence of surface weather conditions (temperature, relative humidity and wind). Cluster analysis of diurnal holm oak pollen cycles revealed the existence of five clusters at each sampling site. Analysis of backward trajectories highlighted specific regional air-flow patterns associated with each site. Findings indicated the contribution of both nearby and distant pollen sources to diurnal cycles. The combined use of cluster analysis and meteorological analysis proved highly suitable for charting the impact of local weather conditions on airborne pollen-count patterns. This method, and the specific tools used here, could be used not only to study diurnal variations in counts for other pollen types and in other biogeographical settings, but also in a number of other research fields involving airborne particle transport modelling, e.g. radionuclide transport in emergency preparedness exercises.

  10. Cluster analysis of intradiurnal holm oak pollen cycles at peri-urban and rural sampling sites in southwestern Spain.

    PubMed

    Hernández-Ceballos, M A; García-Mozo, H; Galán, C

    2015-08-01

    The impact of regional and local weather and of local topography on intradiurnal variations in airborne pollen levels was assessed by analysing bi-hourly holm oak (Quercus ilex subsp. ballota (Desf.) Samp.) pollen counts at two sampling stations located 40 km apart, in southwestern Spain (Cordoba city and El Cabril nature reserve) over the period 2010-2011. Pollen grains were captured using Hirst-type volumetric spore traps. Analysis of regional weather conditions was based on the computation of backward trajectories using the HYSPLIT model. Sampling days were selected on the basis of phenological data; rainy days were eliminated, as were days lying outside a given range of percentiles (P95-P5). Analysis of cycles for the study period, as a whole, revealed differences between sampling sites, with peak bi-hourly pollen counts at night in Cordoba and at midday in El Cabril. Differences were also noted in the influence of surface weather conditions (temperature, relative humidity and wind). Cluster analysis of diurnal holm oak pollen cycles revealed the existence of five clusters at each sampling site. Analysis of backward trajectories highlighted specific regional air-flow patterns associated with each site. Findings indicated the contribution of both nearby and distant pollen sources to diurnal cycles. The combined use of cluster analysis and meteorological analysis proved highly suitable for charting the impact of local weather conditions on airborne pollen-count patterns. This method, and the specific tools used here, could be used not only to study diurnal variations in counts for other pollen types and in other biogeographical settings, but also in a number of other research fields involving airborne particle transport modelling, e.g. radionuclide transport in emergency preparedness exercises. PMID:25315264

  11. Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease.

    PubMed

    Zhang, Rui; Duhl, Tiffany; Salam, Muhammad T; House, James M; Flagan, Richard C; Avol, Edward L; Gilliland, Frank D; Guenther, Alex; Chung, Serena H; Lamb, Brian K; VanReken, Timothy M

    2013-03-01

    Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the WRF/CMAQ air-quality modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 km and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to underestimate walnut and peak oak pollen concentrations, and tends

  12. Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Duhl, T.; Salam, M. T.; House, J. M.; Flagan, R. C.; Avol, E. L.; Gilliland, F. D.; Guenther, A.; Chung, S. H.; Lamb, B. K.; VanReken, T. M.

    2014-03-01

    Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF/CMAQ) modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California (USA) for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to

  13. Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Duhl, T.; Salam, M. T.; House, J. M.; Flagan, R. C.; Avol, E. L.; Gilliland, F. D.; Guenther, A.; Chung, S. H.; Lamb, B. K.; VanReken, T. M.

    2013-03-01

    Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the WRF/CMAQ air-quality modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 km and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to underestimate walnut and peak oak pollen concentrations, and tends to

  14. Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease

    PubMed Central

    Zhang, Rui; Duhl, Tiffany; Salam, Muhammad T.; House, James M.; Flagan, Richard C.; Avol, Edward L.; Gilliland, Frank D.; Guenther, Alex; Chung, Serena H.; Lamb, Brian K.; VanReken, Timothy M.

    2014-01-01

    Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the WRF/CMAQ air-quality modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 km and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to underestimate walnut and peak oak pollen concentrations, and tends

  15. Pollen taphonomy in a canyon stream

    NASA Astrophysics Data System (ADS)

    Fall, Patricia L.

    1987-11-01

    Surface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae- Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

  16. Trends in atmospheric concentrations of weed pollen in the context of recent climate warming in Poznań (Western Poland)

    NASA Astrophysics Data System (ADS)

    Bogawski, Paweł; Grewling, Łukasz; Nowak, Małgorzata; Smith, Matt; Jackowiak, Bogdan

    2014-10-01

    A significant increase in summer temperatures has been observed for the period 1996-2011 in Poznań, Poland. The phenological response of four weed taxa, widely represented by anemophilous species ( Artemisia spp., Rumex spp. and Poaceae and Urticaceae species) to this recent climate warming has been analysed in Poznań by examining the variations in the course of airborne pollen seasons. Pollen data were collected by 7-day Hirst-type volumetric trap. Trends in pollen seasons were determined using Mann-Kendall test and Sen's slope estimator, whereas the relationships between meteorological and aerobiological data were established by Spearman's rank correlation coefficient. Significant trends in pollen data were detected. The duration of pollen seasons of all analysed taxa increased (from +2.0 days/year for Urticaceae to +3.8 days/year for Rumex), which can be attributed to a delay in pollen season end dates rather than earlier start dates. In addition, the intensity of Artemisia pollen seasons significantly decreased and correlates with mean July-September daily minimum temperatures ( r = -0.644, p < 0.01). In contrast, no significant correlations were found between temperature and characteristics of Rumex pollen seasons. The results of this study show that observed shifts in weed pollen seasons in Poznań, i.e. longer duration and later end dates, might be caused by the recorded increase in summer temperature. This influence was the strongest in relation to Artemisia, which is the taxon that flowers latest in the year. The general lack of significant correlations between Rumex and Urticaceae pollen seasons and spring and/or summer temperature suggests that other factors, e.g. land use practices, could also be partially responsible for the observed shifts in pollen seasons.

  17. A comparative analysis of pollinator type and pollen ornamentation in the Araceae and the Arecaceae, two unrelated families of the monocots

    PubMed Central

    Sannier, Julie; Baker, William J; Anstett, Marie-Charlotte; Nadot, Sophie

    2009-01-01

    Background The high diversity of ornamentation type in pollen grains of angiosperms has often been suggested to be linked to diversity in pollination systems. It is commonly stated that smooth pollen grains are associated with wind or water pollination while sculptured pollen grains are associated with biotic pollination. We tested the statistical significance of an association between pollen ornamentation and pollination system in two families of the monocotyledons, the Araceae and the Arecaceae, taking into account the phylogenetic framework. Findings Character optimization was carried out with the Maximum Parsimony method and two different methods of comparative analysis were used: the Concentrated-Change test and the Discrete method. The ancestral ornamentation in Araceae is foveolate/reticulate. It is probably the same in Arecaceae. The ancestral flowers of Araceae were pollinated by beetles while ancestral pollination in Arecaceae is equivocal. A correlation between ornamentation type and pollination was highlighted in Araceae although the results slightly differ depending on the method and the options chosen for performing the analyses. No correlation was found in palms. Conclusion In this study, we show that the relationships between the ornamentation type and the pollination system depend on the family and hence vary among taxonomic groups. We also show that the method chosen may strongly influence the results. PMID:19624836

  18. A reconstruction of Atlantic Central African biomes and forest succession stages derived from modern pollen data and plant functional types

    NASA Astrophysics Data System (ADS)

    Lebamba, J.; Ngomanda, A.; Vincens, A.; Jolly, D.; Favier, C.; Elenga, H.; Bentaleb, I.

    2009-01-01

    New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo) including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs) and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1) modern potential biomes and (2) potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites) and tropical evergreen to semi-evergreen forest (TRFO biome) is well identified from semi-deciduous forest (TSFO biome). When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe) evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map must be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO) is well differentiated from the secondary forest (TSFE), but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

  19. The Effect of Pollen Source vs. Flower Type on Progeny Performance and Seed Predation under Contrasting Light Environments in a Cleistogamous Herb

    PubMed Central

    Munguía-Rosas, Miguel A.; Campos-Navarrete, María J.; Parra-Tabla, Víctor

    2013-01-01

    Dimorphic cleistogamy is a specialized form of mixed mating system where a single plant produces both open, potentially outcrossed chasmogamous (CH) and closed, obligately self-pollinated cleistogamous (CL) flowers. Typically, CH flowers and seeds are bigger and energetically more costly than those of CL. Although the effects of inbreeding and floral dimorphism are critical to understanding the evolution and maintenance of cleistogamy, these effects have been repeatedly confounded. In an attempt to separate these effects, we compared the performance of progeny derived from the two floral morphs while controlling for the source of pollen. That is, flower type and pollen source effects were assessed by comparing the performance of progeny derived from selfed CH vs. CL and outcrossed CH vs. selfed CH flowers, respectively. The experiment was carried out with the herb Ruellia nudiflora under two contrasting light environments. Outcrossed progeny generally performed better than selfed progeny. However, inbreeding depression ranges from low (1%) to moderate (36%), with the greatest value detected under shaded conditions when cumulative fitness was used. Although flower type generally had less of an effect on progeny performance than pollen source did, the progeny derived from selfed CH flowers largely outperformed the progeny from CL flowers, but only under shaded conditions and when cumulative fitness was taken into account. On the other hand, the source of pollen and flower type influenced seed predation, with selfed CH progeny the most heavily attacked by predators. Therefore, the effects of pollen source and flower type are environment-dependant and seed predators may increase the genetic differences between progeny derived from CH and CL flowers. Inbreeding depression alone cannot account for the maintenance of a mixed mating system in R. nudiflora and other unidentified mechanisms must thus be involved. PMID:24260515

  20. The effect of pollen source vs. flower type on progeny performance and seed predation under contrasting light environments in a cleistogamous herb.

    PubMed

    Munguía-Rosas, Miguel A; Campos-Navarrete, María J; Parra-Tabla, Víctor

    2013-01-01

    Dimorphic cleistogamy is a specialized form of mixed mating system where a single plant produces both open, potentially outcrossed chasmogamous (CH) and closed, obligately self-pollinated cleistogamous (CL) flowers. Typically, CH flowers and seeds are bigger and energetically more costly than those of CL. Although the effects of inbreeding and floral dimorphism are critical to understanding the evolution and maintenance of cleistogamy, these effects have been repeatedly confounded. In an attempt to separate these effects, we compared the performance of progeny derived from the two floral morphs while controlling for the source of pollen. That is, flower type and pollen source effects were assessed by comparing the performance of progeny derived from selfed CH vs. CL and outcrossed CH vs. selfed CH flowers, respectively. The experiment was carried out with the herb Ruellia nudiflora under two contrasting light environments. Outcrossed progeny generally performed better than selfed progeny. However, inbreeding depression ranges from low (1%) to moderate (36%), with the greatest value detected under shaded conditions when cumulative fitness was used. Although flower type generally had less of an effect on progeny performance than pollen source did, the progeny derived from selfed CH flowers largely outperformed the progeny from CL flowers, but only under shaded conditions and when cumulative fitness was taken into account. On the other hand, the source of pollen and flower type influenced seed predation, with selfed CH progeny the most heavily attacked by predators. Therefore, the effects of pollen source and flower type are environment-dependant and seed predators may increase the genetic differences between progeny derived from CH and CL flowers. Inbreeding depression alone cannot account for the maintenance of a mixed mating system in R. nudiflora and other unidentified mechanisms must thus be involved. PMID:24260515

  1. The influence from synoptic weather on the variation of air pollution and pollen exposure

    NASA Astrophysics Data System (ADS)

    Grundström, Maria; Dahl, Åslög; Chen, Deliang; Pleijel, Håkan

    2014-05-01

    Exposure to elevated air pollution levels can make people more susceptible to allergies or result in more severe allergic reactions for people with an already pronounced sensitivity to pollen. The aim of this study was to investigate the relationships between urban air pollution (nitrogen oxides, ozone and particles) and airborne Betula pollen in Gothenburg, Sweden, during the pollen seasons for the years 2001-2012. Further, the influence from atmospheric weather pattern on pollen/pollution related risk, using Lamb Weather Types (LWT), was also considered. Daily LWTs were obtained by comparing the variation in atmospheric pressure from a 16 point grid over a given region on earth (scale ~1000km) and essentially describe the air mass movement for the region. They include two non-directional types, cyclonic (C) and anticyclonic (A) and eight directional types depending on the wind direction (N, NE, E... etc.). LWTs with dry and calm meteorological character e.g. limited precipitation and low to moderate wind speeds (A, NE, E, SE) were associated with strongly elevated air pollution and pollen levels where Betula was exceptionally high in LWTs NE and E. The co-variation between Betula pollen and ozone was strong and significant during situations with LWTs A, NE, E and SE. The most important conclusion from this study was that LWTs A, NE, E and SE were associated with high pollen and air pollution levels and can therefore be classified as high risk weather situations for combined air pollution and pollen exposure. Our study shows that LWTs have the potential to be developed into an objective tool for integrated air quality forecasting and a warning system for risk of high exposure situations.

  2. Near-surface and columnar measurements with a micro pulse lidar of atmospheric pollen in Barcelona, Spain

    NASA Astrophysics Data System (ADS)

    Sicard, Michaël; Izquierdo, Rebeca; Alarcón, Marta; Belmonte, Jordina; Comerón, Adolfo; Baldasano, José Maria

    2016-06-01

    We present for the first time continuous hourly measurements of pollen near-surface concentration and lidar-derived profiles of particle backscatter coefficients and of volume and particle depolarization ratios during a 5-day pollination event observed in Barcelona, Spain, between 27 and 31 March 2015. Daily average concentrations ranged from 1082 to 2830 pollen m-3. Platanus and Pinus pollen types represented together more than 80 % of the total pollen. Maximum hourly pollen concentrations of 4700 and 1200 m-3 were found for Platanus and Pinus, respectively. Every day a clear diurnal cycle caused by the vertical transport of the airborne pollen was visible on the lidar-derived profiles with maxima usually reached between 12:00 and 15:00 UT. A method based on the lidar polarization capabilities was used to retrieve the contribution of the pollen to the total aerosol optical depth (AOD). On average the diurnal (09:00-17:00 UT) pollen AOD was 0.05, which represented 29 % of the total AOD. Maximum values of the pollen AOD and its contribution to the total AOD reached 0.12 and 78 %, respectively. The diurnal means of the volume and particle depolarization ratios in the pollen plume were 0.08 and 0.14, with hourly maxima of 0.18 and 0.33, respectively. The diurnal mean of the height of the pollen plume was found at 1.24 km with maxima varying in the range of 1.47-1.78 km. A correlation study is performed (1) between the depolarization ratios and the pollen near-surface concentration to evaluate the ability of the former parameter to monitor pollen release and (2) between the depolarization ratios as well as pollen AOD and surface downward solar fluxes, which cause the atmospheric turbulences responsible for the particle vertical motion, to examine the dependency of the depolarization ratios and the pollen AOD upon solar fluxes. For the volume depolarization ratio the first correlation study yields to correlation coefficients ranging 0.00-0.81 and the second to

  3. [Development of allergic reactivity to Artemesia pollen during combined sensitization to pollen and microbes].

    PubMed

    Ermekova, R K

    1978-08-01

    Some regularities of formation of hypersensitivity of the immediate type to the pollen of Artemisia absinthium were studied under conditions of combined hypersensitivity to pollen and Brucella abortus 19-BA vaccine strain; the latter was administered 3, 12, and 28 days after the pollen. The degree of specific allergic reconstruction to the pollen was studied by passive skin anaphylaxis after Ovary, indirect degranulation of mast cells of healthy rats, and by general anaphylaxis in response to intravenous injection of the Artemisia absinthium pollen water-salt extract. Early formation of allergy to the pollen was observed in the groups of animals with combined hypersensitivity to the pollen and brucellae. The degree of allergic reactivity to the pollen allergen was more expressed in the groups with combined allergy than in those with pure pollen hypersensitivity at all the stages of this experiment. PMID:99195

  4. A Method of Recording and Predicting the Pollen Count.

    ERIC Educational Resources Information Center

    Buck, M.

    1985-01-01

    A hair dryer, plastic funnel, and microscope slide can be used for predicting pollen counts on a day-to-day basis. Materials, methods for assembly, collection technique, meteorological influences, and daily patterns are discussed. Data collected using the apparatus suggest that airborne grass products other than pollen also affect hay fever…

  5. PROJECTING POLLEN ALLERGENS AND THEIR HEALTH IMPLICATIONS IN A CHANGING WORLD

    EPA Science Inventory

    This project will increase our basic understanding of the links between climatic conditions and atmospheric concentrations of pollen and pollen-derived respirable allergenic material, and impacts of airborne pollen on human health. The work will result in new parameterization...

  6. A new measurement method for separating airborne and structureborne noise radiated by aircraft type panels

    NASA Technical Reports Server (NTRS)

    Mcgary, M. C.

    1982-01-01

    The theoretical basis for and experimental validation of a measurement method for separating airborne and structure borne noise radiated by aircraft type panels are presented. An extension of the two microphone, cross spectral, acoustic intensity method combined with existing theory of sound radiation of thin shell structures of various designs, is restricted to the frequency range below the coincidence frequency of the structure. Consequently, the method lends itself to low frequency noise problems such as propeller harmonics. Both an aluminum sheet and two built up aircraft panel designs (two aluminum panels with frames and stringers) with and without added damping were measured. Results indicate that the method is quick, reliable, inexpensive, and can be applied to thin shell structures of various designs.

  7. Ice-type classifications from airborne pulse-limited radar altimeter return waveform characteristics

    NASA Technical Reports Server (NTRS)

    Fedor, L. S.; Hayne, G. S.; Walsh, E. J.

    1989-01-01

    During mid-March 1978, the NASA C-130 aircraft was deployed to Eielson Air Force Base in Fairbanks, Alaska, to make a series of flights over ice in the Beaufort Sea. The radar altimeter data analyzed were obtained northeast of Mackenzie Bay on March 14th in the vicinity of 69.9 deg N, 134.2 deg W. The data were obtained with a 13.9 GHz radar altimeter developed under the NASA Advanced Applications Flight Experiments (AAFE) Program. This airborne radar was built as a forerunner of the Seasat radar altimeter, and utilized the same pulse compression technique. Pulse-limited radar data taken with the altimeter from 1500-m altitude over sea ice are registered to high-quality photography. The backscattered power is statistically related the surface conductivity and to the number of facets whose surface normal is directed towards the radar. The variations of the radar return waveform shape and signal level are correlated with the variation of the ice type determined from photography. The AAFE altimeter has demonstrated that the return waveform shape and signal level of an airborne pulse-limited altimeter at 13.9 GHz respond to sea ice type. The signal level responded dramatically to even a very small fracture in the ice, as long as it occurred directly at the altimeter nadir point. Shear zones and regions of significant compression ridging consistently produced low signal levels. The return waveforms frequently evidenced the characteristics of both specular and diffuse scattering, and there was an indication that the power backscattered at 3 deg off-nadir in a shear zone was actually somewhat higher than that from nadir.

  8. Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

    NASA Astrophysics Data System (ADS)

    Aboulaich, Nadia; Achmakh, Lamiaa; Bouziane, Hassan; Trigo, M. Mar; Recio, Marta; Kadiri, Mohamed; Cabezudo, Baltasar; Riadi, Hassane; Kazzaz, Mohamed

    2013-03-01

    Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008-2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114-173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m3. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2-78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33-42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.

  9. Classification of Baltic Sea ice types by airborne multifrequency microwave radiometer

    SciTech Connect

    Kurvonen, L.; Hallikainen, M.

    1996-11-01

    An airborne multifrequency radiometer (24, 34, 48, and 94 GHz, vertical polarization) was used to investigate the behavior of the brightness temperature of different sea ice types in the Gulf of Bothnia (Baltic Sea). The measurements and the main results of the analysis are presented. The measurements were made in dry and wet conditions (air temperature above and below 0 C). The angle of incidence was 45{degree} in all measurements. The following topics are evaluated: (a) frequency dependency of the brightness temperature of different ice types, (b) the capability of the multifrequency radiometer to classify ice types for winter navigation purposes, and (c) the optimum measurement frequencies for mapping sea ice. The weather conditions had a significant impact on the radiometric signatures of some ice types (snow-covered compact pack ice and frost-covered new ice); the impact was the highest at 94 GHz. In all cases the overall classification accuracy was around 90% (the kappa coefficient was from 0.86 to 0.96) when the optimum channel combination (24/34 GHz and 94 GHz) was used.

  10. Pollen clumping and wind dispersal in an invasive angiosperm.

    PubMed

    Martin, Michael D; Chamecki, Marcelo; Brush, Grace S; Meneveau, Charles; Parlange, Marc B

    2009-09-01

    Pollen dispersal is a fundamental aspect of plant reproductive biology that maintains connectivity between spatially separated populations. Pollen clumping, a characteristic feature of insect-pollinated plants, is generally assumed to be a detriment to wind pollination because clumps disperse shorter distances than do solitary pollen grains. Yet pollen clumps have been observed in dispersion studies of some widely distributed wind-pollinated species. We used Ambrosia artemisiifolia (common ragweed; Asteraceae), a successful invasive angiosperm, to investigate the effect of clumping on wind dispersal of pollen under natural conditions in a large field. Results of simultaneous measurements of clump size both in pollen shedding from male flowers and airborne pollen being dispersed in the atmosphere are combined with a transport model to show that rather than being detrimental, clumps may actually be advantageous for wind pollination. Initial clumps can pollinate the parent population, while smaller clumps that arise from breakup of larger clumps can cross-pollinate distant populations. PMID:21622356

  11. Aerobiology of Juniperus Pollen in Oklahoma, Texas, and New Mexico

    NASA Technical Reports Server (NTRS)

    Levetin, Estelle; Bunderson, Landon; VandeWater, Pete; Luvall, Jeff

    2014-01-01

    Pollen from members of the Cupressaceae are major aeroallergens in many parts of the world. In the south central and southwest United States, Juniperus pollen is the most important member of this family with J. ashei (JA) responsible for severe winter allergy symptoms in Texas and Oklahoma. In New Mexico, pollen from J. monosperma (JM) and other Juniperus species are important contributors to spring allergies, while J. pinchotii (JP) pollinates in the fall affecting sensitive individuals in west Texas, southwest Oklahoma and eastern New Mexico. Throughout this region, JA, JM, and JP occur in dense woodland populations. Generally monitoring for airborne allergens is conducted in urban areas, although the source for tree pollen may be forested areas distant from the sampling sites. Improved pollen forecasts require a better understanding of pollen production at the source. The current study was undertaken to examine the aerobiology of several Juniperus species at their source areas for the development of new pollen forecasting initiatives.

  12. Variations and trends of Fagaceae pollen in Northern Sardinia, Italy

    NASA Astrophysics Data System (ADS)

    Canu, Annalisa; Pellizzaro, Grazia; Arca, Bachisio; Vargiu, Arnoldo

    2016-04-01

    The aim of this study is to analyze variations in the start and the end dates of pollen season, date of maximum concentration peak, pollen season duration, pollen concentration value and Seasonal Pollen Index of airborne Fagaceae pollen series recorded in Sassari, Northern Italy, and to evaluate their relation to meteorological data. Daily pollen concentration data were measured from 1986 to 2008 in a urban area of northern Sardinia (Italy) using a Burkard seven-day recording volumetric spore trap. The date of the peak occurrence was defined as the day when the cumulated daily pollen values reached the 50 % of the total annual pollen concentration. Meteorological data were recorded during the same period by an automatic weather station. Cumulative Degree days were calculated, for each year, from different starting dates using the daily averaging method. The correlation between meteorological variables and the different characteristics of pollen seasons was analyzed using Spearman's correlation tests. In the city of Sassari the Fagaceae airborne pollen content was mainly due to Quercus. The main pollen season took place from April to June. The longest pollen season appeared in the year 2002. The cumulative counts varied over the years, with a mean value of 5,336 pollen grains, a lowest total of 550 in 1986 and a highest total of 8,678 in 2001. Daily pollen concentrations presented positive correlation with temperature, and negative with relative humidity (p<0,0001) and with rainfall. In addition, Cumulative Degree days were significantly correlated with the dates of maximum concentration peak (p<0,0001).

  13. BURSTING POLLEN is required to organize the pollen germination plaque and pollen tube tip in Arabidopsis thaliana.

    PubMed

    Hoedemaekers, Karin; Derksen, Jan; Hoogstrate, Suzanne W; Wolters-Arts, Mieke; Oh, Sung-Aeong; Twell, David; Mariani, Celestina; Rieu, Ivo

    2015-04-01

    Pollen germination may occur via the so-called germination pores or directly through the pollen wall at the site of contact with the stigma. In this study, we addressed what processes take place during pollen hydration (i.e. before tube emergence), in a species with extra-poral pollen germination, Arabidopsis thaliana. A T-DNA mutant population was screened by segregation distortion analysis. Histological and electron microscopy techniques were applied to examine the wild-type and mutant phenotypes. Within 1 h of the start of pollen hydration, an intine-like structure consisting of cellulose, callose and at least partly de-esterified pectin was formed at the pollen wall. Subsequently, this 'germination plaque' gradually extended and opened up to provide passage for the cytoplasm into the emerging pollen tube. BURSTING POLLEN (BUP) was identified as a gene essential for the correct organization of this plaque and the tip of the pollen tube. BUP encodes a novel Golgi-located glycosyltransferase related to the glycosyltransferase 4 (GT4) subfamily which is conserved throughout the plant kingdom. Extra-poral pollen germination involves the development of a germination plaque and BUP defines the correct plastic-elastic properties of this plaque and the pollen tube tip by affecting pectin synthesis or delivery. PMID:25442716

  14. Polarization Analysis of Light Scattered by Pollen Grains of Cryptomeria japonica

    NASA Astrophysics Data System (ADS)

    Iwai, Toshiaki

    2013-06-01

    Pollinosis to airborne pollen grains is a severe problem that concerns the whole world. Almost spring allergies in Japan are caused by pollen grains of Japan cedar (Cryptomeria japonica) during the period of pollination from February to May. One of the key technologies in a pollen monitoring and forecast system is a pollen sensor. The pollen grain of Japan cedar is identified by introducing the degree of polarization to the optical sensor based on the scattered intensity. The detectability and discriminability in identifying the pollen grains of Japan cedar from the polystyrene spherical particles and the Kanto loam grains are achieved up to 95 and 86%, respectively.

  15. Modular method of detection, localization, and counting of multiple-taxon pollen apertures using bag-of-words

    NASA Astrophysics Data System (ADS)

    Lozano-Vega, Gildardo; Benezeth, Yannick; Marzani, Franck; Boochs, Frank

    2014-09-01

    Accurate recognition of airborne pollen taxa is crucial for understanding and treating allergic diseases which affect an important proportion of the world population. Modern computer vision techniques enable the detection of discriminant characteristics. Apertures are among the important characteristics which have not been adequately explored until now. A flexible method of detection, localization, and counting of apertures of different pollen taxa with varying appearances is proposed. Aperture description is based on primitive images following the bag-of-words strategy. A confidence map is estimated based on the classification of sampled regions. The method is designed to be extended modularly to new aperture types employing the same algorithm by building individual classifiers. The method was evaluated on the top five allergenic pollen taxa in Germany, and its robustness to unseen particles was verified.

  16. Pollen analyses for pollination research, unacetolyzed pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollinators can significantly increase the potential yield of crops, but little is known about which pollinators pollinate various crop species. Many pollinators feed on pollen, nectar and plant secretions associated with flowers, and consequently pollen attaches to the pollinators. Identification...

  17. Role of Macrophage Migration Inhibitory Factor (MIF) in Pollen-Induced Allergic Conjunctivitis and Pollen Dermatitis in Mice

    PubMed Central

    Nagata, Yuka; Yoshihisa, Yoko; Matsunaga, Kenji; Rehman, Mati Ur; Kitaichi, Nobuyuki; Shimizu, Tadamichi

    2015-01-01

    Pollen is a clinically important airborne allergen and one of the major causes of allergic conjunctivitis. A subpopulation of patients with atopic dermatitis (AD) are also known to have exacerbated skin eruptions on the face, especially around the eyelids, after contact with pollen. This pollen-induced skin reaction is now known as pollen dermatitis. Macrophage migration inhibitory factor (MIF) is a pluripotent cytokine that plays an essential role in allergic inflammation. Recent findings suggest that MIF is involved in several allergic disorders, including AD. In this study, MIF knockout (KO), MIF transgenic (Tg) and WT littermate mice were immunized with ragweed (RW) pollen or Japanese cedar (JC) pollen and challenged via eye drops. We observed that the numbers of conjunctiva- and eyelid-infiltrating eosinophils were significantly increased in RW and JC pollen-sensitized MIF Tg compared with WT mice or MIF KO mice. The mRNA expression levels of eotaxin, interleukin (IL)-5 and IL-13 were increased in pollen-sensitized eyelid skin sites of MIF Tg mice. An in vitro analysis revealed that high eotaxin expression was induced in dermal fibroblasts by MIF combined with stimulation of IL-4 or IL-13. This eotaxin expression was inhibited by the treatment with CD74 siRNA in fibroblasts. These findings indicate that MIF can induce eosinophil accumulation in the conjunctiva and eyelid dermis exposed to pollen. Therefore, targeted inhibition of MIF might result as a new option to control pollen-induced allergic conjunctivitis and pollen dermatitis. PMID:25647395

  18. Radiometric Normalization of Large Airborne Image Data Sets Acquired by Different Sensor Types

    NASA Astrophysics Data System (ADS)

    Gehrke, S.; Beshah, B. T.

    2016-06-01

    Generating seamless mosaics of aerial images is a particularly challenging task when the mosaic comprises a large number of im-ages, collected over longer periods of time and with different sensors under varying imaging conditions. Such large mosaics typically consist of very heterogeneous image data, both spatially (different terrain types and atmosphere) and temporally (unstable atmo-spheric properties and even changes in land coverage). We present a new radiometric normalization or, respectively, radiometric aerial triangulation approach that takes advantage of our knowledge about each sensor's properties. The current implementation supports medium and large format airborne imaging sensors of the Leica Geosystems family, namely the ADS line-scanner as well as DMC and RCD frame sensors. A hierarchical modelling - with parameters for the overall mosaic, the sensor type, different flight sessions, strips and individual images - allows for adaptation to each sensor's geometric and radiometric properties. Additional parameters at different hierarchy levels can compensate radiome-tric differences of various origins to compensate for shortcomings of the preceding radiometric sensor calibration as well as BRDF and atmospheric corrections. The final, relative normalization is based on radiometric tie points in overlapping images, absolute radiometric control points and image statistics. It is computed in a global least squares adjustment for the entire mosaic by altering each image's histogram using a location-dependent mathematical model. This model involves contrast and brightness corrections at radiometric fix points with bilinear interpolation for corrections in-between. The distribution of the radiometry fixes is adaptive to each image and generally increases with image size, hence enabling optimal local adaptation even for very long image strips as typi-cally captured by a line-scanner sensor. The normalization approach is implemented in HxMap software. It has been

  19. Can we improve pollen season definitions by using the symptom load index in addition to pollen counts?

    PubMed

    Bastl, Katharina; Kmenta, Maximilian; Geller-Bernstein, Carmi; Berger, Uwe; Jäger, Siegfried

    2015-09-01

    Airborne pollen measurements are the foundation of aerobiological research and provide essential raw data for various disciplines. Pollen itself should be considered a relevant factor in air quality. Symptom data shed light on the relationship of pollen allergy and pollination. The aim of this study is to assess the spatial variation of local, regional and national symptom datasets. Ten pollen season definitions are used to calculate the symptom load index for the birch and grass pollen seasons (2013-2014) in Austria. (1) Local, (2) regional and (3) national symptom datasets are used to examine spatial variations and a consistent pattern was found. In conclusion, national datasets are suitable for first insights where no sufficient local or regional dataset is available and season definitions based on percentages provide a practical solution, as they can be applied in regions with different pollen loads and produce more constant results. PMID:25935611

  20. Occupational contact urticaria and late-phase bronchial asthma caused by compositae pollen in a florist.

    PubMed

    Uter, W; Nöhle, M; Randerath, B; Schwanitz, H J

    2001-09-01

    Insect-pollinated members of the plant family Compositae (Asteraceae) rarely cause immediate-type hypersensitivity disease; however, this may have quite disabling consequences, which is shown by the case of a 42-year-old female florist. She developed contact urticaria later accompanied by rhinoconjunctivitis and bronchial asthma with maximum obstruction occurring some hours after the end of occupational exposure to the causative Compositae pollens of, for example, dandelions, blazing star, golden rod, yarrow, Aster ssp, chrysanthemums, and marguerite. Skin testing revealed immediate-type hypersensitivity to several members of the above-mentioned plant family confirmed by demonstration of specific IgE antibodies. Bronchial provocation testing yielded a positive response with all 4 pollen extracts tested. The patient had to give up work in a flower shop, because sufficient avoidance of airborne inhalant exposure was not considered practical. PMID:11526527

  1. Bees associate colour cues with differences in pollen rewards.

    PubMed

    Nicholls, Elizabeth; de Ibarra, Natalie Hempel

    2014-08-01

    In contrast to the wealth of knowledge concerning sucrose-rewarded learning, the question of whether bees learn when they collect pollen from flowers has been little addressed. The nutritional value of pollen varies considerably between species, and it may be that bees learn the features of flowers that produce pollen best suited to the dietary requirements of their larvae. It is still unknown, however, whether a non-ingestive reward pathway for pollen learning exists, and how foraging bees sense differences between pollen types. Here we adopt a novel experimental approach testing the learning ability of bees with pollen rewards. Bumblebees were reared under controlled laboratory conditions. To establish which pollen rewards are distinguishable, individual bees were given the choice of collecting two types of pollen, diluted to varying degrees with indigestible α-cellulose. Bees preferentially collected a particular pollen type, but this was not always the most concentrated sample. Preferences were influenced by the degree of similarity between samples and also by the period of exposure, with bees more readily collecting samples of lower pollen concentration after five trials. When trained differentially, bees were able to associate an initially less-preferred contextual colour with the more concentrated sample, whilst their pollen preferences did not change. Successful learning of contextual cues seems to maintain pollen foraging preferences over repeated exposures, suggesting that fast learning of floral cues may preclude continuous sampling and evaluation of alternative reward sources, leading to constancy in pollen foraging. PMID:24855678

  2. Abundant Type III Lipid Transfer Proteins in Arabidopsis Tapetum Are Secreted to the Locule and Become a Constituent of the Pollen Exine1[W][OPEN

    PubMed Central

    Huang, Ming-Der; Chen, Tung-Ling L.; Huang, Anthony H.C.

    2013-01-01

    Lipid transfer proteins (LTPs) are small secretory proteins in plants with defined lipid-binding structures for possible lipid exocytosis. Special groups of LTPs unique to the anther tapetum are abundant, but their functions are unclear. We studied a special group of LTPs, type III LTPs, in Arabidopsis (Arabidopsis thaliana). Their transcripts were restricted to the anther tapetum, with levels peaking at the developmental stage of maximal pollen-wall exine synthesis. We constructed an LTP-Green Fluorescent Protein (LTP-GFP) plasmid, transformed it into wild-type plants, and monitored LTP-GFP in developing anthers with confocal laser scanning microscopy. LTP-GFP appeared in the tapetum and was secreted via the endoplasmic reticulum-trans-Golgi network machinery into the locule. It then moved to the microspore surface and remained as a component of exine. Immuno-transmission electron microscopy of native LTP in anthers confirmed the LTP-GFP observations. The in vivo association of LTP-GFP and exine in anthers was not observed with non-type III or structurally modified type III LTPs or in transformed exine-defective mutant plants. RNA interference knockdown of individual type III LTPs produced no observable mutant phenotypes. RNA interference knockdown of two type III LTPs produced microscopy-observable morphologic changes in the intine underneath the exine (presumably as a consequence of changes in the exine not observed by transmission electron microscopy) and pollen susceptible to dehydration damage. Overall, we reveal a novel transfer pathway of LTPs in which LTPs bound or nonbound to exine precursors are secreted from the tapetum to become microspore exine constituents; this pathway explains the need for plentiful LTPs to incorporate into the abundant exine. PMID:24096413

  3. Abundant type III lipid transfer proteins in Arabidopsis tapetum are secreted to the locule and become a constituent of the pollen exine.

    PubMed

    Huang, Ming-Der; Chen, Tung-Ling L; Huang, Anthony H C

    2013-11-01

    Lipid transfer proteins (LTPs) are small secretory proteins in plants with defined lipid-binding structures for possible lipid exocytosis. Special groups of LTPs unique to the anther tapetum are abundant, but their functions are unclear. We studied a special group of LTPs, type III LTPs, in Arabidopsis (Arabidopsis thaliana). Their transcripts were restricted to the anther tapetum, with levels peaking at the developmental stage of maximal pollen-wall exine synthesis. We constructed an LTP-Green Fluorescent Protein (LTP-GFP) plasmid, transformed it into wild-type plants, and monitored LTP-GFP in developing anthers with confocal laser scanning microscopy. LTP-GFP appeared in the tapetum and was secreted via the endoplasmic reticulum-trans-Golgi network machinery into the locule. It then moved to the microspore surface and remained as a component of exine. Immuno-transmission electron microscopy of native LTP in anthers confirmed the LTP-GFP observations. The in vivo association of LTP-GFP and exine in anthers was not observed with non-type III or structurally modified type III LTPs or in transformed exine-defective mutant plants. RNA interference knockdown of individual type III LTPs produced no observable mutant phenotypes. RNA interference knockdown of two type III LTPs produced microscopy-observable morphologic changes in the intine underneath the exine (presumably as a consequence of changes in the exine not observed by transmission electron microscopy) and pollen susceptible to dehydration damage. Overall, we reveal a novel transfer pathway of LTPs in which LTPs bound or nonbound to exine precursors are secreted from the tapetum to become microspore exine constituents; this pathway explains the need for plentiful LTPs to incorporate into the abundant exine. PMID:24096413

  4. Recent pollen spectra and zonal vegetation in the western USSR

    NASA Astrophysics Data System (ADS)

    Peterson, G. M.

    The relationship of modern pollen spectra to present-day vegetation is critical to the reconstruction of vegetation and climate from fossil pollen spectra. This study uses isopoll maps to illustrate the pollen-vegetation relationships in the Soviet Union west of 100°E and presents descriptive statistics for 544 modern samples of arboreal pollen and for 370 samples of herb pollen obtained from the Soviet palynological literature. Data are assembled from this large geographic region and presented in a standardized form on a scale which can be used to relate quantitative pollen data to zonal vegetation and climatic variables and to make comparisons with other regions. In order to show the relationship between pollen types and major ecotones in forested and non-forested areas, the pollen data are presented as percentages of a sum including both arboreal and non-arboreal pollen. Major pollen types which attain values of 10% or more in at least one vegetation zone include Betula (birch), Cyperaceae (sedges), Picea (spruce), Pinus (total pine), Pinus sibirica, Ericaceae (heath family), Gramineae (grasses), Artemisia (sage), and Chenopodiaceae (i.e., saltbush, Russian thistle, pigweed family). Samples from the tundra and forest-tundra have high values of Ericaceae (heath family), birch, alder, and sedge pollen. In the boreal forest, pine, spruce, and birch pollen predominate. In the mixed and deciduous forests, Tilia (linden), Quercus (oak), Ulmus (elm), and Corylus (hazel) pollen attain maximum values. In the forest-steppe and steppe zones, arboreal pollen decreases in importance and is replaced by non-arboreal pollen types. Pollen of Artemisia and Chenopodiaceae predominates in the semi-desert zones. In spite of variation in the pollen spectra arising from the use of different sediment types (soil, peat, and river sediments), and human disturbance of vegetation, the pollen spectra are clearly related to zonal vegetation. Pollen spectra from the western USSR show

  5. Antibiotic resistance and OXA-type carbapenemases-encoding genes in airborne Acinetobacter baumannii isolated from burn wards.

    PubMed

    Gao, Jing; Zhao, Xiaonan; Bao, Ying; Ma, Ruihua; Zhou, Yufa; Li, Xinxian; Chai, Tongjie; Cai, Yumei

    2014-03-01

    The study was conducted to investigate drug resistance, OXA-type carbapenemases-encoding genes and genetic diversity in airborne Acinetobacter baumannii (A. baumannii) in burn wards. Airborne A. baumannii were collected in burn wards and their corridors using Andersen 6-stage air sampler from January to June 2011. The isolates susceptibility to 13 commonly used antibiotics was examined according to the CLSI guidelines; OXA-type carbapenemases-encoding genes and molecular diversity of isolates were analyzed, respectively. A total of 16 non-repetitive A. baumannii were isolated, with 10 strains having a resistance rate of greater than 50% against the 13 antibiotics. The resistance rate against ceftriaxone, cyclophosvnamide, ciprofloxacin, and imipenem was 93.75% (15/16), but no isolate observed to be resistant to cefoperazone/sulbactam. Resistance gene analyses showed that all 16 isolates carried OXA-51, and 15 isolates carried OXA-23 except No.15; but OXA-24 and OXA-58 resistance genes not detected. The isolates were classified into 13 genotypes (A-M) according to repetitive extragenic palindromic sequence PCR (REP-PCR) results and only six isolates had a homology ≥90%. In conclusion, airborne A. baumannii in the burn wards had multidrug resistance and complex molecular diversity, and OXA-23 and OXA-51 were dominant mechanisms for resisting carbapenems. PMID:23886986

  6. Pollen Forecast and Dispersion Modelling

    NASA Astrophysics Data System (ADS)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  7. Estimates of common ragweed pollen emission and dispersion over Europe using RegCM-pollen model

    NASA Astrophysics Data System (ADS)

    Liu, L.; Solmon, F.; Vautard, R.; Hamaoui-Laguel, L.; Torma, Cs. Zs.; Giorgi, F.

    2015-11-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In the online model environment where climate is integrated with dispersion and vegetation production, pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000-2010. To reduce the large uncertainties notably due to ragweed density distribution on pollen emission, a calibration based on airborne pollen observations is used. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger. From these simulations health risks associated common ragweed pollen spread are then evaluated through calculation of exposure time above health

  8. Wind-pollination and the roles of pollen allergenic proteins.

    PubMed

    Songnuan, Wisuwat

    2013-12-01

    Over the past few decades, there has been an explosion of understanding of the molecular nature of major allergens contained within pollens from the most important allergenic plant species. Most major allergens belong to only a few protein families. Protein characteristics, cross-reactivity, structures, and IgE binding epitopes have been determined for several allergens. These efforts have led to significant improvements in specific immunotherapy, yet there has been little discussion about the physiological functions of these proteins. Even with large amounts of available information about allergenic proteins from pollens, the incidence of pollen allergy continuously increases worldwide. The reason for this increase is unclear and is most likely due to a combination of factors. One important culprit might be a change in the pollen itself. Knowledge about pollen biology and how pollen is changing as a result of more extreme environmental conditions might improve our understanding of the disease. This review focuses on the characteristics of plants producing allergenic pollens that are relevant to pollen allergy, including the phylogenetic relationships, pollen dispersal distances, amounts of pollen produced, amounts of protein in each type of pollen, and how allergenic proteins are released from pollens. In addition, the physiological roles of major allergenic protein families will be discussed to help us understand why some of these proteins become allergens and why GMO plants with hypoallergenic pollens may not be successful. PMID:24383968

  9. Aerobiology, allergenicity and biochemistry of Madhuca indica Gmel. pollen.

    PubMed

    Boral, D; Roy, I; Bhattacharya, K

    1999-01-01

    An ASTIR volumetric sampler was used for one year (May 1995-April 1996) for aerobiological survey at Beharampore town, a centrally located representative part of West Bengal, to record the occurrence and frequency of airborne Madhuca pollen. The highest frequency of Madhuca pollen was recorded in April when the weather was dry with low relative humidity (RH) and moderately high temperature. Clinical test (skin prick test) showed Madhuca pollen to be one of the major causes of respiratory allergy. 30-60% (NH(4))(2)SO(4) cut fraction showed maximum positivity in skin prick test. Biochemical analysis showed that Madhuca pollen was rich in lipid and protein. SDS-PAGE was performed with the total soluble pollen protein which showed a total of 6 major protein bands, while in isolated fraction (Fr. II) a total of 7 protein bands were obtained. PMID:10607988

  10. Pollen Allergens for Molecular Diagnosis.

    PubMed

    Pablos, Isabel; Wildner, Sabrina; Asam, Claudia; Wallner, Michael; Gadermaier, Gabriele

    2016-04-01

    Pollen allergens are one of the main causes of type I allergies affecting up to 30 % of the population in industrialized countries. Climatic changes affect the duration and intensity of pollen seasons and may together with pollution contribute to increased incidences of respiratory allergy and asthma. Allergenic grasses, trees, and weeds often present similar habitats and flowering periods compromising clinical anamnesis. Molecule-based approaches enable distinction between genuine sensitization and clinically mostly irrelevant IgE cross-reactivity due to, e. g., panallergens or carbohydrate determinants. In addition, sensitivity as well as specificity can be improved and lead to identification of the primary sensitizing source which is particularly beneficial regarding polysensitized patients. This review gives an overview on relevant pollen allergens and their usefulness in daily practice. Appropriate allergy diagnosis is directly influencing decisions for therapeutic interventions, and thus, reliable biomarkers are pivotal when considering allergen immunotherapy in the context of precision medicine. PMID:27002515

  11. Pollen (quick guide)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    What is pollen, and is it haploid or diploid? Pollen is a crucial stage of the plant life cycle — without pollen there will be no seed. When someone says “Think of a plant,” the plant you think of (whether it’s a tree, a tomato plant, or a geranium) is a sporophyte. Most land plants are sporophytes...

  12. Modeling pollen time series using seasonal-trend decomposition procedure based on LOESS smoothing

    NASA Astrophysics Data System (ADS)

    Rojo, Jesús; Rivero, Rosario; Romero-Morte, Jorge; Fernández-González, Federico; Pérez-Badia, Rosa

    2016-08-01

    Analysis of airborne pollen concentrations provides valuable information on plant phenology and is thus a useful tool in agriculture—for predicting harvests in crops such as the olive and for deciding when to apply phytosanitary treatments—as well as in medicine and the environmental sciences. Variations in airborne pollen concentrations, moreover, are indicators of changing plant life cycles. By modeling pollen time series, we can not only identify the variables influencing pollen levels but also predict future pollen concentrations. In this study, airborne pollen time series were modeled using a seasonal-trend decomposition procedure based on LOcally wEighted Scatterplot Smoothing (LOESS) smoothing (STL). The data series—daily Poaceae pollen concentrations over the period 2006-2014—was broken up into seasonal and residual (stochastic) components. The seasonal component was compared with data on Poaceae flowering phenology obtained by field sampling. Residuals were fitted to a model generated from daily temperature and rainfall values, and daily pollen concentrations, using partial least squares regression (PLSR). This method was then applied to predict daily pollen concentrations for 2014 (independent validation data) using results for the seasonal component of the time series and estimates of the residual component for the period 2006-2013. Correlation between predicted and observed values was r = 0.79 (correlation coefficient) for the pre-peak period (i.e., the period prior to the peak pollen concentration) and r = 0.63 for the post-peak period. Separate analysis of each of the components of the pollen data series enables the sources of variability to be identified more accurately than by analysis of the original non-decomposed data series, and for this reason, this procedure has proved to be a suitable technique for analyzing the main environmental factors influencing airborne pollen concentrations.

  13. Allergenic pollen season variations in the past two decades under changing climate in the United States

    PubMed Central

    Zhang, Yong; Bielory, Leonard; Mi, Zhongyuan; Cai, Ting; Robock, Alan; Georgopoulos, Panos

    2014-01-01

    Many diseases are linked with climate trends and variations. In particular, climate change is expected to alter the spatiotemporal dynamics of allergenic airborne pollen and potentially increase occurrence of allergic airway disease. Understanding the spatiotemporal patterns of changes in pollen season timing and levels is thus important in assessing climate impacts on aerobiology and allergy caused by allergenic airborne pollen. Here we describe the spatiotemporal patterns of changes in the seasonal timing and levels of allergenic airborne pollen for multiple taxa in different climate regions at a continental scale. The allergenic pollen seasons of representative trees, weeds and grass during the past decade (2001–2010) across the contiguous United States have been observed to start 3.0 (95% Confidence Interval (CI), 1.1–4.9) days earlier on average than in the 1990s (1994–2000). The average peak value and annual total of daily counted airborne pollen have increased by 42.4% (95% CI, 21.9%–62.9%) and 46.0% (95% CI, 21.5%–70.5%), respectively. Changes of pollen season timing and airborne levels depend on latitude, and are associated with changes of growing degree days, frost free days, and precipitation. These changes are likely due to recent climate change and particularly the enhanced warming and precipitation at higher latitudes in the contiguous United States. PMID:25266307

  14. Preservation of cycad and Ginkgo pollen

    USGS Publications Warehouse

    Frederiksen, N.O.

    1978-01-01

    Pollen grains of Ginkgo, Cycas, and Encephalartos were chemically treated together with pollen of Quercus, Alnus, and Pinus, the latter three genera being used as standards. The experiments showed that: (1) boiling the pollen for 8-10 hours in 10% KOH had little if any effect on any of the grains; (2) lengthy acetolysis treatment produced some degradation or corrosion, particularly in Ginkgo and Cycas, but the grains of even these genera remained easily recognizable; (3) oxidation with KMnO4 followed by H2O2 showed that pollen of Ginkgo, Cycas, and Encephalartos remains better preserved than that of Quercus and Alnus, and although Ginkgo and Encephalartos probably are slightly less resistant to oxidation than Pinus, no great differences exists between these monosulcate types and Pinus. Thus the experiments show that, at least for sediments low in bacteria, cycad and Ginkgo pollen should be well represented in the fossil record as far as their preservational capabilities are concerned. ?? 1978.

  15. Immersion freezing of birch pollen washing water

    NASA Astrophysics Data System (ADS)

    Augustin, S.; Wex, H.; Niedermeier, D.; Pummer, B.; Grothe, H.; Hartmann, S.; Tomsche, L.; Clauss, T.; Voigtländer, J.; Ignatius, K.; Stratmann, F.

    2013-11-01

    Birch pollen grains are known to be ice nucleating active biological particles. The ice nucleating activity has previously been tracked down to biological macromolecules that can be easily extracted from the pollen grains in water. In the present study, we investigated the immersion freezing behavior of these ice nucleating active (INA) macromolecules. Therefore we measured the frozen fractions of particles generated from birch pollen washing water as a function of temperature at the Leipzig Aerosol Cloud Interaction Simulator (LACIS). Two different birch pollen samples were considered, with one originating from Sweden and one from the Czech Republic. For the Czech and Swedish birch pollen samples, freezing was observed to start at -19 and -17 °C, respectively. The fraction of frozen droplets increased for both samples down to -24 °C. Further cooling did not increase the frozen fractions any more. Instead, a plateau formed at frozen fractions below 1. This fact could be used to determine the amount of INA macromolecules in the droplets examined here, which in turn allowed for the determination of nucleation rates for single INA macromolecules. The main differences between the Swedish birch pollen and the Czech birch pollen were obvious in the temperature range between -17 and -24 °C. In this range, a second plateau region could be seen for Swedish birch pollen. As we assume INA macromolecules to be the reason for the ice nucleation, we concluded that birch pollen is able to produce at least two different types of INA macromolecules. We were able to derive parameterizations for the heterogeneous nucleation rates for both INA macromolecule types, using two different methods: a simple exponential fit and the Soccer ball model. With these parameterization methods we were able to describe the ice nucleation behavior of single INA macromolecules from both the Czech and the Swedish birch pollen.

  16. Hygroscopic weight gain of pollen grains from Juniperus species

    NASA Astrophysics Data System (ADS)

    Bunderson, Landon D.; Levetin, Estelle

    2015-05-01

    Juniperus pollen is highly allergenic and is produced in large quantities across Texas, Oklahoma, and New Mexico. The pollen negatively affects human populations adjacent to the trees, and since it can be transported hundreds of kilometers by the wind, it also affects people who are far from the source. Predicting and tracking long-distance transport of pollen is difficult and complex. One parameter that has been understudied is the hygroscopic weight gain of pollen. It is believed that juniper pollen gains weight as humidity increases which could affect settling rate of pollen and thus affect pollen transport. This study was undertaken to examine how changes in relative humidity affect pollen weight, diameter, and settling rate. Juniperus ashei, Juniperus monosperma, and Juniperus pinchotii pollen were applied to greased microscope slides and placed in incubation chambers under a range of temperature and humidity levels. Pollen on slides were weighed using an analytical balance at 2- and 6-h intervals. The size of the pollen was also measured in order to calculate settling rate using Stokes' Law. All pollen types gained weight as humidity increased. The greatest settling rate increase was exhibited by J. pinchotii which increased by 24 %.

  17. Hygroscopic weight gain of pollen grains from Juniperus species.

    PubMed

    Bunderson, Landon D; Levetin, Estelle

    2015-05-01

    Juniperus pollen is highly allergenic and is produced in large quantities across Texas, Oklahoma, and New Mexico. The pollen negatively affects human populations adjacent to the trees, and since it can be transported hundreds of kilometers by the wind, it also affects people who are far from the source. Predicting and tracking long-distance transport of pollen is difficult and complex. One parameter that has been understudied is the hygroscopic weight gain of pollen. It is believed that juniper pollen gains weight as humidity increases which could affect settling rate of pollen and thus affect pollen transport. This study was undertaken to examine how changes in relative humidity affect pollen weight, diameter, and settling rate. Juniperus ashei, Juniperus monosperma, and Juniperus pinchotii pollen were applied to greased microscope slides and placed in incubation chambers under a range of temperature and humidity levels. Pollen on slides were weighed using an analytical balance at 2- and 6-h intervals. The size of the pollen was also measured in order to calculate settling rate using Stokes' Law. All pollen types gained weight as humidity increased. The greatest settling rate increase was exhibited by J. pinchotii which increased by 24 %. PMID:25008113

  18. Large Eddy Simulation of Pollen Transport in the Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Chamecki, Marcelo; Meneveau, Charles; Parlange, Marc B.

    2007-11-01

    The development of genetically modified crops and questions about cross-pollination and contamination of natural plant populations enhanced the importance of understanding wind dispersion of airborne pollen. The main objective of this work is to simulate the dispersal of pollen grains in the atmospheric surface layer using large eddy simulation. Pollen concentrations are simulated by an advection-diffusion equation including gravitational settling. Of great importance is the specification of the bottom boundary conditions characterizing the pollen source over the canopy and the deposition process everywhere else. The velocity field is discretized using a pseudospectral approach. However the application of the same discretization scheme to the pollen equation generates unphysical solutions (i.e. negative concentrations). The finite-volume bounded scheme SMART is used for the pollen equation. A conservative interpolation scheme to determine the velocity field on the finite volume surfaces was developed. The implementation is validated against field experiments of point source and area field releases of pollen.

  19. Determination of allergenic load and pollen count of Cupressus arizonica pollen by flow cytometry using Cup a1 polyclonal antibody.

    PubMed

    Benítez, Francisco Moreno; Camacho, Antonio Letrán; Del Cuvillo Bernal, Alfonso; de Medina, Pedro Lobatón Sánchez; Cózar, Francisco J García; Romeu, Ma Luisa Espinazo

    2013-07-10

    Background: There is an increase in the incidence of pollen related allergy, thus information on pollen schedules would be a great asset for physicians to improve the clinical care of patients. Like cypress pollen sensitization shows a high prevalence among the causes of allergic rhinitis, and therefore it is of interest to use it like a model of study, distinguishing cypress pollen, pollen count and allergenic load level. In this work, we use a flow cytometry based technique to obtain both Cupressus arizonica pollen count and allergenic load, using specific rabbit polyclonal antibody Cup a1 and its comparison with optical microscopy technique measurement. Methods: Airborne samples were collected from Burkard Spore-Trap and Burkard Cyclone Cupressus arizonica pollen was studied using specific rabbit polyclonal antibody Cup a1, labelled with AlexaFluor(®) 488 or 750 and analysed by Flow Cytometry in both an EPICS XL and Cyan ADP cytometers (Beckman Coulter(®) ). Optical microscopy study was realized with a Leica optical microscope. Bland & Altman was used to determine agreement between both techniques measured. Results: We can identify three different populations based on rabbit polyclonal antibody Cup a1 staining. The main region (44.5%) had 97.3% recognition, a second region (25%) with 28% and a third region (30.5%) with 68% respectively. Immunofluorescence and confocal microscopy showed that main region corresponds to whole pollen grains, the second region are pollen without exine and the third region is constituted by smaller particles with allergenic properties. Pollen schedule shows a higher correlation measured by optical microscopy and flow cytometry in the pollen count with a p-value: 0.0008E(-2) and 0.0002 with regard to smaller particles, so the Bland & Altman measurement showed a good correlation between them, p-value: 0,0003. Conclusion: Determination of pollen count and allergenic load by flow cytometry represents an important tool in the

  20. Modeling the dispersion of Ambrosia artemisiifolia L. pollen with the model system COSMO-ART.

    PubMed

    Zink, Katrin; Vogel, Heike; Vogel, Bernhard; Magyar, Donát; Kottmeier, Christoph

    2012-07-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic plant that is spreading throughout Europe. Ragweed pollen can be transported over large distances by the wind. Even low pollen concentrations of less than 10 pollen m(-3) can lead to health problems in sensitive persons. Therefore, forecasting the airborne concentrations of ragweed pollen is becoming more and more important for public health. The question remains whether distant pollen sources need to be considered in reliable forecasts. We used the extended numerical weather prediction system COSMO-ART to simulate the release and transport of ragweed pollen in central Europe. A pollen episode (September 12-16, 2006) in north-eastern Germany was modeled in order to find out where the pollen originated. For this purpose, several different source regions were taken into account and their individual impact on the daily mean pollen concentration and the performance of the forecast were studied with the means of a 2 × 2 contingency table and skill scores. It was found that the majority of the pollen originated in local areas, but up to 20% of the total pollen load came from distant sources in Hungary. It is concluded that long-distance transport should not be neglected when predicting pollen concentrations. PMID:21744099

  1. Modeling the dispersion of Ambrosia artemisiifolia L. pollen with the model system COSMO-ART

    NASA Astrophysics Data System (ADS)

    Zink, Katrin; Vogel, Heike; Vogel, Bernhard; Magyar, Donát; Kottmeier, Christoph

    2012-07-01

    Common ragweed ( Ambrosia artemisiifolia L.) is a highly allergenic plant that is spreading throughout Europe. Ragweed pollen can be transported over large distances by the wind. Even low pollen concentrations of less than 10 pollen m-3 can lead to health problems in sensitive persons. Therefore, forecasting the airborne concentrations of ragweed pollen is becoming more and more important for public health. The question remains whether distant pollen sources need to be considered in reliable forecasts. We used the extended numerical weather prediction system COSMO-ART to simulate the release and transport of ragweed pollen in central Europe. A pollen episode (September 12-16, 2006) in north-eastern Germany was modeled in order to find out where the pollen originated. For this purpose, several different source regions were taken into account and their individual impact on the daily mean pollen concentration and the performance of the forecast were studied with the means of a 2 × 2 contingency table and skill scores. It was found that the majority of the pollen originated in local areas, but up to 20% of the total pollen load came from distant sources in Hungary. It is concluded that long-distance transport should not be neglected when predicting pollen concentrations.

  2. Pollen sequence at Kirchner Marsh, Minnesota

    USGS Publications Warehouse

    Winter, T.C.

    1962-01-01

    A pollen diagram from Kirchner Marsh, southeastern Minnesota, records a continuous vegetation sequence from the time of Late Wisconsin ice retreat from the region. The late-glacial and early postglacial portions of the diagram are correlated with a radiocarbon-dated diagram from Madelia, Minnesota. Both diagrams show a series of maxima of pollen types in the early postglacial that suggest a significant climatic change at that time. The Kirchner diagram, in addition, shows high percentages of nonarboreal pollen later in the postglacial that indicate an advance of prairie elements into the area between 7200 and 5000 years ago.

  3. A biology-driven receptor model for daily pollen allergy risk in Korea based on Weibull probability density function

    NASA Astrophysics Data System (ADS)

    Kim, Kyu Rang; Kim, Mijin; Choe, Ho-Seong; Han, Mae Ja; Lee, Hye-Rim; Oh, Jae-Won; Kim, Baek-Jo

    2016-07-01

    Pollen is an important cause of respiratory allergic reactions. As individual sanitation has improved, allergy risk has increased, and this trend is expected to continue due to climate change. Atmospheric pollen concentration is highly influenced by weather conditions. Regression analysis and modeling of the relationships between airborne pollen concentrations and weather conditions were performed to analyze and forecast pollen conditions. Traditionally, daily pollen concentration has been estimated using regression models that describe the relationships between observed pollen concentrations and weather conditions. These models were able to forecast daily concentrations at the sites of observation, but lacked broader spatial applicability beyond those sites. To overcome this limitation, an integrated modeling scheme was developed that is designed to represent the underlying processes of pollen production and distribution. A maximum potential for airborne pollen is first determined using the Weibull probability density function. Then, daily pollen concentration is estimated using multiple regression models. Daily risk grade levels are determined based on the risk criteria used in Korea. The mean percentages of agreement between the observed and estimated levels were 81.4-88.2 % and 92.5-98.5 % for oak and Japanese hop pollens, respectively. The new models estimated daily pollen risk more accurately than the original statistical models because of the newly integrated biological response curves. Although they overestimated seasonal mean concentration, they did not simulate all of the peak concentrations. This issue would be resolved by adding more variables that affect the prevalence and internal maturity of pollens.

  4. Influence of Pollen Nutrition on Honey Bee Health: Do Pollen Quality and Diversity Matter?

    PubMed Central

    Di Pasquale, Garance; Salignon, Marion; Le Conte, Yves; Belzunces, Luc P.; Decourtye, Axel; Kretzschmar, André; Suchail, Séverine; Brunet, Jean-Luc; Alaux, Cédric

    2013-01-01

    Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen) necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens) and diversity (polyfloral pollen diet) on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level), and on the tolerance to the microsporidian parasite Nosemaceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification), phenoloxidase (immunity) and alkaline phosphatase (metabolism)). We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context) of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health. PMID:23940803

  5. A combinatorial morphospace for angiosperm pollen

    NASA Astrophysics Data System (ADS)

    Mander, Luke

    2016-04-01

    The morphology of angiosperm (flowering plant) pollen is extraordinarily diverse. This diversity results from variations in the morphology of discrete anatomical components. These components include the overall shape of a pollen grain, the stratification of the exine, the number and form of any apertures, the type of dispersal unit, and the nature of any surface ornamentation. Different angiosperm pollen morphotypes reflect different combinations of these discrete components. In this talk, I ask the following question: given the anatomical components of angiosperm pollen that are known to exist in the plant kingdom, how many unique biologically plausible combinations of these components are there? I explore this question from the perspective of enumerative combinatorics using an algorithm I have written in the Python programming language. This algorithm (1) calculates the number of combinations of these components; (2) enumerates those combinations; and (3) graphically displays those combinations. The result is a combinatorial morphospace that reflects an underlying notion that the process of morphogenesis in angiosperm pollen can be thought of as an n choose k counting problem. I compare the morphology of extant and fossil angiosperm pollen grains to this morphospace, and suggest that from a combinatorial point of view angiosperm pollen is not as diverse as it could be, which may be a result of developmental constraints.

  6. Aerobiological studies and low allerginicity of date-palm pollen in the UAE.

    PubMed

    Almehdi, Ahmed M; Maraqa, Munjed; Abdulkhalik, Samar

    2005-06-01

    Date-Palm trees (Phoenix dactylifera L.) are the most abundant crop in the United Arab Emirates (UAE). The aim of this work was to conduct aerobiological studies on Date-Palm pollens and correlate that to allergenicity. An aerobiological survey was performed at three Date-Palm farms. Radioallergosorbent test (RAST) and total IgE were performed on 477 airborne allergic patients. Small mass bioactive constituents were fractionated and isolated by HPLC. Aerobiological studies demonstrate the short distance traveled by the Date-Palm pollens. Pollen counts were about 800 counts/m3 within the Date-Palm farms and decreased by about 80% just 100 meters away from the farm area and almost diminished beyond 200 meters. Scanning electron micrograph of the pollen grain showed a uniform smooth texture with an oval shape. Out of 477 airborne allergic patients having high total IgE counts, only 2.3% gave positive RAST for Date-Palm pollen. HPLC chromatogram separated the non-protein content of Date-Palm pollen into four distinct peak fractions. The present study revealed that Date-Palm pollens have a low allergic effect on airborne allergic people. The short distance traveled by the pollen, the smooth texture, the short pollination period and low molecular weight biomolecule content may be the main factors behind the low allergenicity. PMID:16134484

  7. PECTIN METHYLESTERASE48 is involved in Arabidopsis pollen grain germination.

    PubMed

    Leroux, Christelle; Bouton, Sophie; Kiefer-Meyer, Marie-Christine; Fabrice, Tohnyui Ndinyanka; Mareck, Alain; Guénin, Stéphanie; Fournet, Françoise; Ringli, Christoph; Pelloux, Jérôme; Driouich, Azeddine; Lerouge, Patrice; Lehner, Arnaud; Mollet, Jean-Claude

    2015-02-01

    Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme48-/- pollen grains. In contrast, the PME activity was lower in pme48-/-, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme48-/- with the optimum germination medium supplemented with 2.5 mm calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca(2+) necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination. PMID:25524442

  8. Variability within the 10-Year Pollen Rain of a Seasonal Neotropical Forest and Its Implications for Paleoenvironmental and Phenological Research

    PubMed Central

    Haselhorst, Derek S.; Moreno, J. Enrique; Punyasena, Surangi W.

    2013-01-01

    Tropical paleoecologists use a combination of mud-water interface and modern pollen rain samples (local samples of airborne pollen) to interpret compositional changes within fossil pollen records. Taxonomic similarities between the composition of modern assemblages and fossil samples are the basis of reconstructing paleoclimates and paleoenvironments. Surface sediment samples reflect a time-averaged accumulation of pollen spanning several years or more. Due to experimental constraints, modern pollen rain samples are generally collected over shorter timeframes (1–3 years) and are therefore less likely to capture the full range of natural variability in pollen rain composition and abundance. This potentially biases paleoenvironmental interpretations based on modern pollen rain transfer functions. To determine the degree to which short-term environmental change affects the composition of the aerial pollen flux of Neotropical forests, we sampled ten years of the seasonal pollen rain from Barro Colorado Island, Panama and compared it to climatic and environmental data over the same ten-year span. We establish that the pollen rain effectively captured the strong seasonality and stratification of pollen flow within the forest canopy and that individual taxa had variable sensitivity to seasonal and annual changes in environmental conditions, manifested as changes in pollen productivity. We conclude that modern pollen rain samples capture the reproductive response of moist tropical plants to short-term environmental change, but that consequently, pollen rain-based calibrations need to include longer sampling periods (≥7 years) to reflect the full range of natural variability in the pollen output of a forest and simulate the time-averaging present in sediment samples. Our results also demonstrate that over the long-term, pollen traps placed in the forest understory are representative samples of the pollen output of both canopy and understory vegetation. Aerial pollen

  9. Exposure to grass pollen--but not birch pollen--affects lung function in Swedish children.

    PubMed

    Gruzieva, O; Pershagen, G; Wickman, M; Melén, E; Hallberg, J; Bellander, T; Lõhmus, M

    2015-09-01

    Allergic response to pollen is increasing worldwide, leading to high medical and social costs. However, the effect of pollen exposure on lung function has rarely been investigated. Over 1800 children in the Swedish birth cohort BAMSE were lung-function- and IgE-tested at the age of 8 and 16 years old. Daily concentrations for 9 pollen types together with measurements for ozone, NO2 , PM10 , PM2.5 were estimated for the index day as well as up to 6 days before the testing. Exposure to grass pollen during the preceding day was associated with a reduced forced expiratory volume in 8-yr-olds; -32.4 ml; 95% CI: -50.6 to -14.2, for an increase in three pollen counts/m³. Associations appeared stronger in children sensitized to pollen allergens. As the grass species flower late in the pollen season, the allergy care routines might be weakened during this period. Therefore, allergy information may need to be updated to increase awareness among grass pollen-sensitized individuals. PMID:26011717

  10. Discriminating phytoplankton functional types (PFTs) in the coastal ocean using the inversion algorithm PHYDOTax and airborne imaging spectrometer data

    NASA Astrophysics Data System (ADS)

    Palacios, S. L.; Schafer, C. B.; Broughton, J.; Guild, L. S.; Kudela, R. M.

    2013-12-01

    There is a need in the Biological Oceanography community to discriminate among phytoplankton groups within the bulk chlorophyll pool to understand energy flow through ecosystems, to track the fate of carbon in the ocean, and to detect and monitor-for harmful algal blooms (HABs). The ocean color community has responded to this demand with the development of phytoplankton functional type (PFT) discrimination algorithms. These PFT algorithms fall into one of three categories depending on the science application: size-based, biogeochemical function, and taxonomy. The new PFT algorithm Phytoplankton Detection with Optics (PHYDOTax) is an inversion algorithm that discriminates taxon-specific biomass to differentiate among six taxa found in the California Current System: diatoms, dinoflagellates, haptophytes, chlorophytes, cryptophytes, and cyanophytes. PHYDOTax was developed and validated in Monterey Bay, CA for the high resolution imaging spectrometer, Spectroscopic Aerial Mapping System with On-board Navigation (SAMSON - 3.5 nm resolution). PHYDOTax exploits the high spectral resolution of an imaging spectrometer and the improved spatial resolution that airborne data provides for coastal areas. The objective of this study was to apply PHYDOTax to a relatively lower resolution imaging spectrometer to test the algorithm's sensitivity to atmospheric correction, to evaluate capability with other sensors, and to determine if down-sampling spectral resolution would degrade its ability to discriminate among phytoplankton taxa. This study is a part of the larger Hyperspectral Infrared Imager (HyspIRI) airborne simulation campaign which is collecting Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imagery aboard NASA's ER-2 aircraft during three seasons in each of two years over terrestrial and marine targets in California. Our aquatic component seeks to develop and test algorithms to retrieve water quality properties (e.g. HABs and river plumes) in both marine and in

  11. Discriminating Phytoplankton Functional Types (PFTs) in the Coastal Ocean Using the Inversion Algorithm Phydotax and Airborne Imaging Spectrometer Data

    NASA Technical Reports Server (NTRS)

    Palacios, Sherry L.; Schafer, Chris; Broughton, Jennifer; Guild, Liane S.; Kudela, Raphael M.

    2013-01-01

    There is a need in the Biological Oceanography community to discriminate among phytoplankton groups within the bulk chlorophyll pool to understand energy flow through ecosystems, to track the fate of carbon in the ocean, and to detect and monitor-for harmful algal blooms (HABs). The ocean color community has responded to this demand with the development of phytoplankton functional type (PFT) discrimination algorithms. These PFT algorithms fall into one of three categories depending on the science application: size-based, biogeochemical function, and taxonomy. The new PFT algorithm Phytoplankton Detection with Optics (PHYDOTax) is an inversion algorithm that discriminates taxon-specific biomass to differentiate among six taxa found in the California Current System: diatoms, dinoflagellates, haptophytes, chlorophytes, cryptophytes, and cyanophytes. PHYDOTax was developed and validated in Monterey Bay, CA for the high resolution imaging spectrometer, Spectroscopic Aerial Mapping System with On-board Navigation (SAMSON - 3.5 nm resolution). PHYDOTax exploits the high spectral resolution of an imaging spectrometer and the improved spatial resolution that airborne data provides for coastal areas. The objective of this study was to apply PHYDOTax to a relatively lower resolution imaging spectrometer to test the algorithm's sensitivity to atmospheric correction, to evaluate capability with other sensors, and to determine if down-sampling spectral resolution would degrade its ability to discriminate among phytoplankton taxa. This study is a part of the larger Hyperspectral Infrared Imager (HyspIRI) airborne simulation campaign which is collecting Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imagery aboard NASA's ER-2 aircraft during three seasons in each of two years over terrestrial and marine targets in California. Our aquatic component seeks to develop and test algorithms to retrieve water quality properties (e.g. HABs and river plumes) in both marine and in

  12. Maize pollen is an important allergen in occupationally exposed workers

    PubMed Central

    2011-01-01

    Background The work- or environmental-related type I sensitization to maize pollen is hardly investigated. We sought to determine the prevalence of sensitization to maize pollen among exposed workers and to identify the eliciting allergens. Methods In July 2010, 8 out of 11 subjects were examined who were repeatedly exposed to maize pollen by pollinating maize during their work in a biological research department. All 8 filled in a questionnaire and underwent skin prick testing (SPT) and immune-specific analyses. Results 5 out of the 8 exposed subjects had repeatedly suffered for at least several weeks from rhinitis, 4 from conjunctivitis, 4 from urticaria, and 2 from shortness of breath upon occupational exposure to maize pollen. All symptomatic workers had specific IgE antibodies against maize pollen (CAP class ≥ 1). Interestingly, 4 of the 5 maize pollen-allergic subjects, but none of the 3 asymptomatic exposed workers had IgE antibodies specific for grass pollen. All but one of the maize pollen-allergic subjects had suffered from allergic grass pollen-related symptoms for 6 to 11 years before job-related exposure to maize pollen. Lung function testing was normal in all cases. In immunoblot analyses, the allergenic components could be identified as Zea m 1 and Zea m 13. The reactivity is mostly caused by cross-reactivity to the homologous allergens in temperate grass pollen. Two sera responded to Zea m 3, but interestingly not to the corresponding timothy allergen indicating maize-specific IgE reactivity. Conclusion The present data suggest that subjects pollinating maize are at high risk of developing an allergy to maize pollen as a so far underestimated source of occupational allergens. For the screening of patients with suspected maize pollen sensitization, the determination of IgE antibodies specific for maize pollen is suitable. PMID:22165847

  13. Effects of CO₂ on Acer negundo pollen fertility, protein content, allergenic properties, and carbohydrates.

    PubMed

    Silva, M; Ribeiro, H; Abreu, I; Cruz, A; Esteves da Silva, J C G

    2015-05-01

    Atmospheric gaseous pollutants can induce qualitative and quantitative changes in airborne pollen characteristics. In this work, it was investigated the effects of carbon dioxide (CO2) on Acer negundo pollen fertility, protein content, allergenic properties, and carbohydrates. Pollen was collected directly from the anthers and in vitro exposed to three CO2 levels (500, 1000, and 3000 ppm) for 6 and 24 h in an environmental chamber. Pollen fertility was determined using viability and germination assays, total soluble protein was determined with Coomassie Protein Assay Reagent, and the antigenic and allergenic properties were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunological techniques using patients' sera. Also, pollen fructose, sucrose, and glucose values were determined. Carbon dioxide exposure affected negatively pollen fertility, total soluble protein content, and fructose content. The patient sera revealed increased IgE reactivity to proteins of A. negundo pollen exposed to increasing levels of the pollutant. No changes were detected in the SDS-PAGE protein profiles and in sucrose and glucose levels. Our results indicate that increase in atmospheric CO2 concentrations can have a negative influence of some features of A. negundo airborne pollen that can influence the reproductive processes as well as respiratory pollen allergies in the future. PMID:25471717

  14. Evolutionarily conserved phenylpropanoid pattern on angiosperm pollen.

    PubMed

    Fellenberg, Christin; Vogt, Thomas

    2015-04-01

    The male gametophyte of higher plants appears as a solid box containing the essentials to transmit genetic material to the next generation. These consist of haploid generative cells that are required for reproduction, and an invasive vegetative cell producing the pollen tube, both mechanically protected by a rigid polymer, the pollen wall, and surrounded by a hydrophobic pollen coat. This coat mediates the direct contact to the biotic and abiotic environments. It contains a mixture of compounds required not only for fertilization but also for protection against biotic and abiotic stressors. Among its metabolites, the structural characteristics of two types of phenylpropanoids, hydroxycinnamic acid amides and flavonol glycosides, are highly conserved in Angiosperm pollen. Structural and functional aspects of these compounds will be discussed. PMID:25739656

  15. Allergies, asthma, and pollen

    MedlinePlus

    ... Some trees Some grasses Weeds Ragweed Watch the weather and the season The amount of pollen in the air can affect whether you or your child has hay fever and asthma symptoms. On hot, dry, windy days, more pollen is in the air. ...

  16. Plant pollen content in the air of Lublin (central-eastern Poland) and risk of pollen allergy.

    PubMed

    Piotrowska-Weryszko, Krystyna; Weryszko-Chmielewska, Elżbieta

    2014-01-01

    Pollen monitoring was carried out in Lublin in 2001-2012 by the volumetric method using a Hirst-type spore trap (Lanzoni VPPS 2000). Daily pollen concentrations considerably differed in the particular years. The pollen counts with the biggest variability were observed in the first half of a year when woody plants flowering. The highest annual pollen index were noted for the following taxa: Betula, Urtica, Pinaceae, Poaceae and Alnus. Betula annual total showed the greatest diversity in the study years. The number of days on which the pollen concentration exceeded the threshold values, thereby inducing allergies, was determined for the taxa producing the most allergenic pollen. The above-mentioned taxa primarily included the following: Poaceae, in the case of which the highest number of days with the risk of occurrence of pollen allergy was found (35), Betula (18), and Artemisia (10). The following taxa: Alnus (14 days), Populus (11 days), Fraxinus (10 days), and Quercus (8 days), were also characterized by a large number of days on which their pollen concentrations exceeded the threshold values. The occurrence of periods of high concentration of particular pollen types were also noted. Risk of pollen allergy appeared the earliest at the beginning of February during Alnus and Corylus blooming. High concentrations of other woody plants were recorded from the last ten days of March to about 20 May, and of herbaceous plants from the first/last half of May-beginning of October. PMID:25528903

  17. Pollen counts and their relationship to meteorological factors in Ankara, Turkey during 2005-2008

    NASA Astrophysics Data System (ADS)

    Kizilpinar, Ilginc; Civelek, Ersoy; Tuncer, Ayfer; Dogan, Cahit; Karabulut, Erdem; Sahiner, Umit M.; Yavuz, S. Tolga; Sackesen, Cansin

    2011-07-01

    Pollen plays an important role in the development and exacerbation of allergic diseases. We aimed to investigate the days with highest counts of the most allergenic pollens and to identify the meteorological factors affecting pollen counts in the atmosphere of Ankara, Turkey. Airborne pollen measurements were carried out from 2005 to 2008 with a Burkard volumetric 7-day spore trap. Microscope counts were converted into atmospheric concentrations and expressed as pollen grains/m3. Meteorological parameters were obtained from the State Meteorological Service. All statistical analyses were done with pollen counts obtained from March to October for each year. The percentages of tree, grass and weed pollens were 72.1% ( n = 24,923), 12.8% ( n = 4,433) and 15.1% ( n = 5,219), respectively. The Pinaceae family from tree taxa (39% to 57%) and the Chenopodiaceae/Amaranthaceae family from weed taxa, contributed the highest percentage of pollen (25% to 43%), while from the grass taxa, only the Poaceae family was detected from 2005 to 2008. Poaceae and Chenopodiaceae/Amaranthaceae families, which are the most allergenic pollens, were found in high numbers from May to August in Ankara. In multiple logistic regression analysis, wind speed (OR = 1.18, CI95% = 1.02-1.36, P = 0.023) for tree pollen, daily mean temperature (OR = 1.10, CI95% = 1.04-1.17, P = 0.001) and sunshine hours (OR = 1.15, CI95% = 1.01-1.30, P = 0.033) for grass pollen, and sunshine hours (OR = 3.79, CI95% = 1.03-13.92, P = 0.044) for weed pollen were found as significant risk factors for high pollen count. The pollen calendar and its association with meteorological factors depend mainly on daily temperature, sunshine hours and wind speed, which may help draw the attention of physicians and allergic patients to days with high pollen counts.

  18. [A relationship between birch pollen counts and meteorological factors in Sapporo].

    PubMed

    Shirasaki, Hideaki; Yamamoto, Tetsuo; Saikawa, Etsuko; Seki, Nobuhiko; Asakura, Kohji; Kataura, Akikatsu; Himi, Tetsuo

    2014-05-01

    Occurrence of airborne pollen in Sapporo has been studied for 19 years during the period between 1995 and 2013. There are wide year-to-year variations in the quantities of birch pollens. A simple linear regression with the least squares method was used for studying correlations between the annual quantities of birch pollens and the meteorological factors. A significant positive correlation was found between the hours of sunlight in June of the preceding year and the annual birch pollen concentrations with the correlation coefficient, R = 0.667. Also, we found the significant positive correlation between the hours of sunlight in March and the annual birch pollen concentrations with the correlation coefficient, R = 0.684. These results suggest that the atmospheric birch pollen counts can be predicted from meteorological factors. PMID:24956742

  19. Seasonal variation of birch and grass pollen loads and allergen release at two sites in the German Alps

    NASA Astrophysics Data System (ADS)

    Jochner, Susanne; Lüpke, Marvin; Laube, Julia; Weichenmeier, Ingrid; Pusch, Gudrun; Traidl-Hoffmann, Claudia; Schmidt-Weber, Carsten; Buters, Jeroen T. M.; Menzel, Annette

    2015-12-01

    Less vegetated mountainous areas may provide better conditions for allergy sufferers. However, atmospheric transport can result in medically relevant pollen loads in such regions. The majority of investigations has focused on the pollen load, expressed as daily averages of pollen per cubic meter of air (pollen grains/m³); however, the severity of allergic symptoms is also determined by the actual allergen content of this pollen, its pollen potency, which may differ between high and low altitudes. We analysed airborne birch and grass pollen concentrations along with allergen content (birch: Bet v 1, grass: Phl p 5) at two different altitudes (734 and 2650 m a.s.l.) in the Zugspitze region (2009-2010). Back-trajectories were calculated for the high altitude site and for specific days with abrupt increases in pollen potency. We observed several days with medically relevant pollen concentrations at the highest site. In addition, a few days with pollen were not associated with allergens and vice versa. The calculated seasonal mean allergen release per pollen grain was 1.8-3.3 pg Bet v 1 and 5.7 pg Phl p 5 in the valley and 1.1-3.7 pg Bet v 1 and 0.7-1.5 pg Phl p 5 at the high altitude site. Back-trajectories revealed that high pollen potency at the higher site was generally associated with south-westerly to south-easterly (birch), or northerly (grass) wind directions. By investigating days with sudden increases in pollen potency, however, it was difficult to draw definitive conclusions on long- or short-range transport. Our findings suggest that people allergic to pollen might suffer less at higher altitudes and further indicate that a risk assessment relying on the actual concentration of airborne pollen does not necessarily reflect the actual allergy exposure of individuals.

  20. Annexin5 Plays a Vital Role in Arabidopsis Pollen Development via Ca2+-Dependent Membrane Trafficking

    PubMed Central

    Zhu, Jingen; Wu, Xiaorong; Yuan, Shunjie; Qian, Dong; Nan, Qiong

    2014-01-01

    The regulation of pollen development and pollen tube growth is a complicated biological process that is crucial for sexual reproduction in flowering plants. Annexins are widely distributed from protists to higher eukaryotes and play multiple roles in numerous cellular events by acting as a putative “linker” between Ca2+ signaling, the actin cytoskeleton and the membrane, which are required for pollen development and pollen tube growth. Our recent report suggested that downregulation of the function of Arabidopsis annexin 5 (Ann5) in transgenic Ann5-RNAi lines caused severely sterile pollen grains. However, little is known about the underlying mechanisms of the function of Ann5 in pollen. This study demonstrated that Ann5 associates with phospholipid membrane and this association is stimulated by Ca2+ in vitro. Brefeldin A (BFA) interferes with endomembrane trafficking and inhibits pollen germination and pollen tube growth. Both pollen germination and pollen tube growth of Ann5-overexpressing plants showed increased resistance to BFA treatment, and this effect was regulated by calcium. Overexpression of Ann5 promoted Ca2+-dependent cytoplasmic streaming in pollen tubes in vivo in response to BFA. Lactrunculin (LatB) significantly prohibited pollen germination and tube growth by binding with high affinity to monomeric actin and preferentially targeting dynamic actin filament arrays and preventing actin polymerization. Overexpression of Ann5 did not affect pollen germination or pollen tube growth in response to LatB compared with wild-type, although Ann5 interacts with actin filaments in a manner similar to some animal annexins. In addition, the sterile pollen phenotype could be only partially rescued by Ann5 mutants at Ca2+-binding sites when compared to the complete recovery by wild-type Ann5. These data demonstrated that Ann5 is involved in pollen development, germination and pollen tube growth through the promotion of endomembrane trafficking modulated by

  1. Immunological Interactive Effects between Pollen Grains and Their Cytoplasmic Granules on Brown Norway Rats

    PubMed Central

    2009-01-01

    Background Grass pollen is one of the most important aeroallergen vectors in Europe. Under some meteorological factors, pollen grains can release pollen cytoplasmic granules (PCGs). PCGs induce allergic responses. Several studies have shown that during a period of thunderstorms the number of patients with asthma increases because of higher airborne concentrations of PCGs. Objective The aims of the study were to assess the allergenicity of interactive effects between pollen and PCGs and to compare it with allergenicity of Timothy grass pollen and PCGs in Brown Norway rats. Methods Rats were sensitized (day 0) and challenged (day 21) with pollen grains and/or PCGs. Four groups were studied: pollen-pollen (PP), PCGs-PCGs (GG), pollen-PCGs (PG), and PCGs-pollen (GP). Blood samples, bronchoalveolar lavage fluid, and bronchial lymph node were collected at day 25. IgE and IgG1 levels in sera were assessed by enzyme-linked immunosorbent assay. Alveolar cells, protein, and cytokine concentrations were quantified in bronchoalveolar lavage fluid. T-cell proliferation, in response to pollen or granules, was performed by lymph node assay. Results Interactive effects between pollen and PCGs increased IgE and IgG1 levels when compared with those of the negative control. These increases were lower than those of the PP group but similar to the levels obtained by the GG group. Whatever was used in the sensitization and/or challenge phase, PCGs increased lymphocyte and Rantes levels compared with those of the pollen group. The interactive effects increased IL-1α and IL-1β compared with those of the PP and GG groups. Conclusions Immunologic interactive effects have been shown between pollen and PCGs. For humoral and cellular allergic responses, interactive effects between the 2 aeroallergenic sources used in this study seem to be influenced mainly by PCGs. PMID:23283149

  2. Health effects of airborne particulate matter: do we know enough to consider regulating specific particle types or sources?

    PubMed

    Grahame, Thomas J; Schlesinger, Richard B

    2007-05-01

    Researchers and regulators have often considered preferentially regulating the types of ambient airborne particulate matter (PM) most relevant to human health effects. While few would argue the inherent merits of such a policy, many believe there may not yet be enough information to differentially regulate PM species. New evidence, using increasingly sophisticated methodologies, has become available in the last several years, allowing more accurate assessment of exposure and resultant associations with specific types of PM, or PM derived from different sources. Such new studies may also allow differentiation of effects from different chemical components in the same study against the same health endpoints. This article considers whether this new evidence might be adequate to allow us to "speciate" PM types or sources by severity of health effects. We address this issue with respect to two widespread sources of PM, emissions from motor vehicles and coal-fired power plants. Emissions from less widespread sources, residual oil and steel/coking facilities, are also discussed in order to illustrate how health effects associated with such emissions might instead be associated with more widespread sources when accurate exposure information is unavailable. Based upon evaluation of studies and methodologies which appear to contain the most accurate information on exposure and response to important emissions, including variable local emissions, it is concluded that public health will likely be better protected by reduction of various vehicular emissions than by continued regulation of the total mass of fine PM (PM <2.5 microm, or PM2.5) as if all PM in this mode is equitoxic. However, the knowledge base is incomplete. Important remaining research questions are identified. PMID:17497526

  3. Rice UDP-Glucose Pyrophosphorylase1 Is Essential for Pollen Callose Deposition and Its Cosuppression Results in a New Type of Thermosensitive Genic Male Sterility[W][OA

    PubMed Central

    Chen, Rongzhi; Zhao, Xiao; Shao, Zhe; Wei, Zhe; Wang, Yuanyuan; Zhu, Lili; Zhao, Jie; Sun, Mengxiang; He, Ruifeng; He, Guangcun

    2007-01-01

    UDP-glucose pyrophosphorylase (UGPase) catalyzes the reversible production of glucose-1-phosphate and UTP to UDP-glucose and pyrophosphate. The rice (Oryza sativa) genome contains two homologous UGPase genes, Ugp1 and Ugp2. We report a functional characterization of rice Ugp1, which is expressed throughout the plant, with highest expression in florets, especially in pollen during anther development. Ugp1 silencing by RNA interference or cosuppression results in male sterility. Expressing a double-stranded RNA interference construct in Ugp1-RI plants resulted in complete suppression of both Ugp1 and Ugp2, together with various pleiotropic developmental abnormalities, suggesting that UGPase plays critical roles in plant growth and development. More importantly, Ugp1-cosuppressing plants contained unprocessed intron-containing primary transcripts derived from transcription of the overexpression construct. These aberrant transcripts undergo temperature-sensitive splicing in florets, leading to a novel thermosensitive genic male sterility. Pollen mother cells (PMCs) of Ugp1-silenced plants appeared normal before meiosis, but during meiosis, normal callose deposition was disrupted. Consequently, the PMCs began to degenerate at the early meiosis stage, eventually resulting in complete pollen collapse. In addition, the degeneration of the tapetum and middle layer was inhibited. These results demonstrate that rice Ugp1 is required for callose deposition during PMC meiosis and bridges the apoplastic unloading pathway and pollen development. PMID:17400897

  4. Estimation of aerosol type from airborne hyperspectral data: a new technique designed for industrial plume characterization

    NASA Astrophysics Data System (ADS)

    Deschamps, A.; Marion, R.; Foucher, P.-Y.; Briottet, X.

    2012-11-01

    The determination of the aerosol type in a plume from remotely sensed data without any a priori knowledge is a challenging task. If several methods have already been developed to characterize the aerosols from multi or hyperspectral data, they are not suited for industrial particles, which have specific physical and optical properties, changing quickly and in a complex way with the distance from the source emission. From radiative transfer equations, we have developed an algorithm, based on a Look-Up Table approach, enabling the determination of the type of this kind of particles from hyperspectral data. It consists in the selection of pixels pairs, located at the transitions between two kinds of grounds (or between an illuminated and a shadow area), then in the comparison between normalized estimated Aerosol Optical Thicknesses (AOTs) and pre-calculated AOTs. The application of this algorithm to simulated data leads to encouraging results: the selection of only six pixels pairs allows the algorithm to differentiate aerosols emitted by a metallurgical plant from biomass burning particles, urban aerosols and particles from an oil depot explosion, regardless the size and the aerosol concentration. The algorithm performances are better for a relatively high AOT but the single scattering approximation does not enable the characterization of thick plumes (AOT above 2.0). However, the choice of transitions (type of grounds) does not seem to significantly affect the results.

  5. Analysis of Allergenic Pollen by FTIR Microspectroscopy.

    PubMed

    Zimmerman, B; Tafintseva, V; Bağcıoğlu, M; Høegh Berdahl, M; Kohler, A

    2016-01-01

    Fourier transform infrared (FTIR) spectroscopy is a powerful tool for the identification and characterization of pollen and spores. However, interpretation and multivariate analysis of infrared microscopy spectra of single pollen grains are hampered by Mie-type scattering. In this paper, we introduce a novel sampling setup for infrared microspectroscopy of pollens preventing strong Mie-type scattering. Pollen samples were embedded in a soft paraffin layer between two sheets of polyethylene foils without any further sample pretreatment. Single-grain infrared spectra of 13 different pollen samples, belonging to 11 species, were obtained and analyzed by the new approach and classified by sparse partial least-squares regression (PLSR). For the classification, chemical and physical information were separated by extended multiplicative signal correction and used together to build a classification model. A training set of 260 spectra and an independent test set of 130 spectra were used. Robust sparse classification models allowing the biochemical interpretation of the classification were obtained by the sparse PLSR, because only a subset of variables was retained for the analysis. With accuracy values of 95% and 98%, for the independent test set and full cross-validation respectively, the method is outperforming the previously published studies on development of an automated pollen analysis. Since the method is compatible with standard air-samplers, it can be employed with minimal modification in regular aerobiology studies. When compared with optical microscopy, which is the benchmark method in pollen analysis, the infrared microspectroscopy method offers better taxonomic resolution, as well as faster, more economical, and bias-free measurement. PMID:26599685

  6. Comparison of field and airborne laser scanning based crown cover estimates across land cover types in Kenya

    NASA Astrophysics Data System (ADS)

    Heiskanen, J.; Korhonen, L.; Hietanen, J.; Heikinheimo, V.; Schafer, E.; Pellikka, P. K. E.

    2015-04-01

    Tree crown cover (CC) provides means for the continuous land cover characterization of complex tropical landscapes with multiple land uses and variable degrees of degradation. It is also a key parameter in the international forest definitions that are basis for monitoring global forest cover changes. Recently, airborne laser scanning (ALS) has emerged as a practical method for accurate CC mapping, but ALS derived CC estimates have rarely been assessed with field data in the tropics. Here, our objective was to compare the various field and ALS based CC estimates across multiple land cover types in the Taita Hills, Kenya. The field data was measured from a total of 178 sample plots (0.1 ha) in 2013 and 2014. The most accurate field measurement method, line intersect sampling using Cajanus tube, was used in 37 plots. Other methods included CC estimate based on the tree inventory data (144 plots), crown relascope (43 plots) and hemispherical photography (30 plots). Three ALS data sets, including two scanners and flying heights, were acquired concurrently with the field data collection. According to the results, the first echo cover index (FCI) from ALS data had good agreement with the most accurate field based CC estimates (RMSD 7.1% and 2.7% depending on the area and scan). The agreement with other field based methods was considerably worse. Furthermore, we observed that ALS cover indices were robust between the different scans in the overlapping area. In conclusion, our results suggest that ALS provides a reliable method for continuous CC mapping across tropical land cover types although dense shrub layer and tree-like herbaceous plants can cause overestimation of CC.

  7. Suitability of different pollen as alternative food for the predatory mite Amblyseius swirskii (Acari, Phytoseiidae).

    PubMed

    Goleva, Irina; Zebitz, Claus P W

    2013-11-01

    The predacious mite Amblyseius swirskii Athias-Henriot is used as a biological control agent against various pests in greenhouses. Pollen offered as supplementary food is reported to improve their fast establishment and performance. However, the nutritional suitability of different pollens for A. swirskii is not sufficiently known yet. Pollens of 21 plant species were offered to the mites as exclusive food during preimaginal development. Preimaginal mortality and developmental time have been assessed, followed by a life-table analysis of the emerged adults and a calculation of demographic parameters. Amblyseius swirskii can feed exclusively on pollen, but the nutritional value of the pollens differed significantly. Pollens of Lilium martagon and Hippeastrum sp. were toxic, causing 100 % preimaginal mortality, probably due to secondary plant compounds. Hibiscus syriacus pollen was absolutely incompatible for the juvenile and adult mites, possibly due to their external morphology, differing from all the other pollens tested and leading to 100 % preimaginal mortality also. Considering all parameters, feeding on Aesculus hippocastanum, Crocus vernus, Echinocereus sp. and Paulownia tomentosa pollens lead to the best performance of the mites. Feeding on most pollens resulted in no or low preimaginal mortality of A. swirskii, but affected significantly developmental time, adult longevity, and reproduction parameters. Commercial bee pollen was not able to improve life-table parameters compared to pure pollen of the plant species. Pollens of Helianthus annuus, Corylus avellana and a Poaceae mix were less suitable as food source and resulted in a poor performance of all tested parameters. Compared with literature data, 18 pollens tested proved to be a similar or better food source than cattail pollen, qualifying A. swirskii as a positively omnivorous type IV species. Pollens of Ricinus communis and Zea mays can be recommended as supplementary food offered as banker plants

  8. Feature Extraction and Machine Learning for the Classification of Brazilian Savannah Pollen Grains.

    PubMed

    Gonçalves, Ariadne Barbosa; Souza, Junior Silva; Silva, Gercina Gonçalves da; Cereda, Marney Pascoli; Pott, Arnildo; Naka, Marco Hiroshi; Pistori, Hemerson

    2016-01-01

    The classification of pollen species and types is an important task in many areas like forensic palynology, archaeological palynology and melissopalynology. This paper presents the first annotated image dataset for the Brazilian Savannah pollen types that can be used to train and test computer vision based automatic pollen classifiers. A first baseline human and computer performance for this dataset has been established using 805 pollen images of 23 pollen types. In order to access the computer performance, a combination of three feature extractors and four machine learning techniques has been implemented, fine tuned and tested. The results of these tests are also presented in this paper. PMID:27276196

  9. Feature Extraction and Machine Learning for the Classification of Brazilian Savannah Pollen Grains

    PubMed Central

    Souza, Junior Silva; da Silva, Gercina Gonçalves

    2016-01-01

    The classification of pollen species and types is an important task in many areas like forensic palynology, archaeological palynology and melissopalynology. This paper presents the first annotated image dataset for the Brazilian Savannah pollen types that can be used to train and test computer vision based automatic pollen classifiers. A first baseline human and computer performance for this dataset has been established using 805 pollen images of 23 pollen types. In order to access the computer performance, a combination of three feature extractors and four machine learning techniques has been implemented, fine tuned and tested. The results of these tests are also presented in this paper. PMID:27276196

  10. Platanus pollen season in Andalusia (southern Spain): trends and modeling.

    PubMed

    Alcázar, Purificación; García-Mozo, Herminia; Trigo, Maria Del Mar; Ruiz, Luis; González-Minero, Francisco José; Hidalgo, Pablo; Díaz de la Guardia, Consuelo; Galán, Carmen

    2011-09-01

    Platanus is a major cause of pollen allergy in many Spanish cities. The present paper reports an analysis of Platanus pollen season throughout the Andalusia region (southern Spain), which has among the highest pollen counts and the highest incidence of Platanus-related allergies in Europe. The main aim was to analyze pollen season trends from 1992 to 2010 in Andalusia; models were also constructed to forecast the start of the season. Daily pollen counts were recorded using Hirst-type volumetric spore-traps. Pollen season start-dates were very similar at all sites, usually occurring in March. The pollen season was delayed over the study period. The Pollen-season duration and Pollen index generally increased throughout the study period. The starting date for temperature accumulation was around the 10th February, although the threshold temperatures varied by site. The regional model for Andalusia failed to provide sufficiently accurate results compared with sub-regional or local models. For modeling purposes, three sub-regions are recommended: Inland, East Coast and West Coast. PMID:21748144

  11. Hydrogen ions associated with the dry deposition of pollen

    SciTech Connect

    Noll, K.E.; Khalili, E.K. )

    1988-01-01

    The data provided in this paper demonstrates that pollen can generate significant amounts of hydrogen ions when added to water and that the deposition of tree pollen in forested areas represents a significant hydrogen ion source. Measurements of dry deposition of pollen were made during the months of May and June, 1987 in Northern Wisconsin, using a smooth surrogate surface. Rain samples were also collected. Deposited particles were weighed to determine mass fluxes, then washed and ion chromatographed for SO {sub 4} = and NO {sub 3} {minus} analysis. Species of pollen collected from different types of trees during the sampling period were analyzed for SO{sub 4} = NO {sub 3} and other trace constituents. The micrograms of hydrogen ions (protons) generated per gram for different types of pollen added to water, were measured. From 56 to 566 gm were generated per gram or pollen added. The amount generated varied with pollen type. Based on this information, the equivalent protons from the dry deposition of pollen were calculated and compared with the wet deposition proton data. The sulfate, nitrate, and protons associated with dry deposition were of a magnitude comparable with wet deposition.

  12. The C-terminal hypervariable domain targets Aradopsis ROP9 to the invaginated pollen tube plasma membrane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rop9 is a small GTPase of the Type II class, whereas the often studied type I Rops play roles during pollen tube growth. In pollen, Rop9 is located at the invaginated plasma membrane that surrounds the sperm cells, whereas type I Rops are located at the apical membrane of the pollen tube. The C-ter...

  13. Functionality Based Detection of Airborne Engineered Nanoparticles in Quasi Real Time: A New Type of Detector and a New Metric

    PubMed Central

    Neubauer, Nicole

    2013-01-01

    A new type of detector which we call the Catalytic Activity Aerosol Monitor (CAAM) was investigated towards its capability to detect traces of commonly used industrial catalysts in ambient air in quasi real time. Its metric is defined as the catalytic activity concentration (CAC) expressed per volume of sampled workplace air. We thus propose a new metric which expresses the presence of nanoparticles in terms of their functionality - in this case a functionality of potential relevance for damaging effects - rather than their number, surface, or mass concentration in workplace air. The CAAM samples a few micrograms of known or anticipated airborne catalyst material onto a filter first and then initiates a chemical reaction which is specific to that catalyst. The concentration of specific gases is recorded using an IR sensor, thereby giving the desired catalytic activity. Due to a miniaturization effort, the laboratory prototype is compact and portable. Sensitivity and linearity of the CAAM response were investigated with catalytically active palladium and nickel nano-aerosols of known mass concentration and precisely adjustable primary particle size in the range of 3–30nm. With the miniature IR sensor, the smallest detectable particle mass was found to be in the range of a few micrograms, giving estimated sampling times on the order of minutes for workplace aerosol concentrations typically reported in the literature. Tests were also performed in the presence of inert background aerosols of SiO2, TiO2, and Al2O3. It was found that the active material is detectable via its catalytic activity even when the particles are attached to a non-active background aerosol. PMID:23504803

  14. Down-Regulating CsHT1, a Cucumber Pollen-Specific Hexose Transporter, Inhibits Pollen Germination, Tube Growth, and Seed Development1[OPEN

    PubMed Central

    Cheng, Jintao; Wang, Zhenyu; Yao, Fengzhen; Gao, Lihong; Ma, Si; Zhang, Zhenxian

    2015-01-01

    Efficient sugar transport is needed to support the high metabolic activity of pollen tubes as they grow through the pistil. Failure of transport results in male sterility. Although sucrose transporters have been shown to play a role in pollen tube development, the role of hexoses and hexose transporters is not as well established. The pollen of some species can grow in vitro on hexose as well as on sucrose, but knockouts of individual hexose transporters have not been shown to impair fertilization, possibly due to transporter redundancy. Here, the functions of CsHT1, a hexose transporter from cucumber (Cucumis sativus), are studied using a combination of heterologous expression in yeast (Saccharomyces cerevisiae), histochemical and immunohistochemical localization, and reverse genetics. The results indicate that CsHT1 is a plasma membrane-localized hexose transporter with high affinity for glucose, exclusively transcribed in pollen development and expressed both at the levels of transcription and translation during pollen grain germination and pollen tube growth. Overexpression of CsHT1 in cucumber pollen results in a higher pollen germination ratio and longer pollen tube growth than wild-type pollen in glucose- or galactose-containing medium. By contrast, antisense suppression of CsHT1 leads to inhibition of pollen germination and pollen tube elongation in the same medium and results in a decrease of seed number per fruit and seed size when antisense transgenic pollen is used to fertilize wild-type or transgenic cucumber plants. The important role of CsHT1 in pollen germination, pollen tube growth, and seed development is discussed. PMID:25888616

  15. Pollen Viability and Pollen Tube Attrition in Cranberry (Vaccinium macrocarpon)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The content of mature seed in a cranberry fruit increases with stigmatic pollen load. On average, however, only two seeds result for every tetrad of pollen deposited. What then is the fate of the two remaining pollen grains fused in each tetrad? Germination in vitro revealed that most of the grains ...

  16. Characterization of Pollen Dispersion in the Neighborhood of Tokyo, Japan in the Spring of 2005 and 2006

    PubMed Central

    Ishibashi, Yoshinaga; Ohno, Hideki; Oh-ishi, Shuji; Matsuoka, Takeshi; Kizaki, Takako; Yoshizumi, Kunio

    2008-01-01

    The behavior of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) pollens in an urban area was examined through the measurements of the dispersion characteristics at the various sampling locations in both outdoor and indoor environments. Airborne pollens were counted continuously for three months during the Japanese cedar pollen and Japanese cypress seasons in 2005 and 2006 by the use of Durham’s pollen trap method in and around Tokyo, Japan. The dispersion of pollens at the rooftop of Kyoritsu Women’s University was observed to be at extremely high levels in 2005 compared with previously reported results during the past two decades. As for Japanese cedar pollen, the maximum level was observed as 440 counts cm−2 day−1 on 18 March 2005. Japanese cypress pollen dispersed in that area in the latter period was compared with the Japanese cedar pollen dispersions. The maximum dispersion level was observed to be 351 counts cm−2 day−1 on 7 April 2005. Total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 5,552 and 1,552 counts cm−2 for the three months (Feb., Mar. and Apr.) in 2005, respectively. However, the dispersion of both pollens in 2006 was very low. The total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 421 and 98 counts cm−2 for three months (Feb., Mar. and Apr.) in 2006, respectively. Moreover, the pollen deposition on a walking person in an urban area showed that the pollen counts on feet were observed to be extremely high compared with the ones on the shoulder, back and legs. These findings suggested that pollen fell on the surface of the paved road at first, rebounded to the ambient air and was deposited on the residents again. Furthermore, the regional distribution of the total pollen dispersion in the South Kanto area was characterized on 15–16 March 2005 and on 14–15 March 2006. Although the pollen levels in 2005 were much higher than in 2006, it

  17. The Role of Arabidopsis ABCG9 and ABCG31 ATP Binding Cassette Transporters in Pollen Fitness and the Deposition of Steryl Glycosides on the Pollen Coat[W

    PubMed Central

    Choi, Hyunju; Ohyama, Kiyoshi; Kim, Yu-Young; Jin, Jun-Young; Lee, Saet Buyl; Yamaoka, Yasuyo; Muranaka, Toshiya; Suh, Mi Chung; Fujioka, Shozo; Lee, Youngsook

    2014-01-01

    The pollen coat protects pollen grains from harmful environmental stresses such as drought and cold. Many compounds in the pollen coat are synthesized in the tapetum. However, the pathway by which they are transferred to the pollen surface remains obscure. We found that two Arabidopsis thaliana ATP binding cassette transporters, ABCG9 and ABCG31, were highly expressed in the tapetum and are involved in pollen coat deposition. Upon exposure to dry air, many abcg9 abcg31 pollen grains shriveled up and collapsed, and this phenotype was restored by complementation with ABCG9pro:GFP:ABCG9. GFP-tagged ABCG9 or ABCG31 localized to the plasma membrane. Electron microscopy revealed that the mutant pollen coat resembled the immature coat of the wild type, which contained many electron-lucent structures. Steryl glycosides were reduced to about half of wild-type levels in the abcg9 abcg31 pollen, but no differences in free sterols or steryl esters were observed. A mutant deficient in steryl glycoside biosynthesis, ugt80A2 ugt80B1, exhibited a similar phenotype. Together, these results indicate that steryl glycosides are critical for pollen fitness, by supporting pollen coat maturation, and that ABCG9 and ABCG31 contribute to the accumulation of this sterol on the surface of pollen. PMID:24474628

  18. The weak effects of climatic change on Plantago pollen concentration: 17 years of monitoring in Northwestern Spain

    NASA Astrophysics Data System (ADS)

    González-Parrado, Zulima; Valencia-Barrera, Rosa Ma.; Vega-Maray, Ana Ma.; Fuertes-Rodríguez, Carmen Reyes; Fernández-González, Delia

    2014-09-01

    Plantago L. species are very common in nitrified areas such as roadsides and their pollen is a major cause of pollinosis in temperate regions. In this study, we sampled airborne pollen grains in the city of León (NW, Spain) from January 1995 to December 2011, by using a Burkard® 7-day-recording trap. The percentage of Plantago pollen compared to the total pollen count ranged from 11 % (1997) to 3 % (2006) in the period under study. Peak pollen concentrations were recorded in May and June. Our 17-year analysis failed to disclose significant changes in the seasonal trend of plantain pollen concentration. In addition, there were no important changes in the start dates of pollen release and the meteorological parameters analyzed did not show significant variations in their usual trends. We analyzed the influence of several meteorological parameters on Plantago pollen concentration to explain the differences in pollen concentration trends during the study. Our results show that temperature, sun hours, evaporation, and relative humidity are the meteorological parameters best correlated to the behavior of Plantago pollen grains. In general, the years with low pollen concentrations correspond to the years with less precipitation or higher temperatures. We calculated the approximate Plantago flowering dates using the cumulative sum of daily maximum temperatures and compared them with the real bloom dates. The differences obtained were 4 days in 2009, 3 days in 2010, and 1 day in 2011 considering the complete period of pollination.

  19. The weak effects of climatic change on Plantago pollen concentration: 17 years of monitoring in Northwestern Spain.

    PubMed

    González-Parrado, Zulima; Valencia-Barrera, Rosa Ma; Vega-Maray, Ana Ma; Fuertes-Rodríguez, Carmen Reyes; Fernández-González, Delia

    2014-09-01

    Plantago L. species are very common in nitrified areas such as roadsides and their pollen is a major cause of pollinosis in temperate regions. In this study, we sampled airborne pollen grains in the city of León (NW, Spain) from January 1995 to December 2011, by using a Burkard® 7-day-recording trap. The percentage of Plantago pollen compared to the total pollen count ranged from 11% (1997) to 3% (2006) in the period under study. Peak pollen concentrations were recorded in May and June. Our 17-year analysis failed to disclose significant changes in the seasonal trend of plantain pollen concentration. In addition, there were no important changes in the start dates of pollen release and the meteorological parameters analyzed did not show significant variations in their usual trends. We analyzed the influence of several meteorological parameters on Plantago pollen concentration to explain the differences in pollen concentration trends during the study. Our results show that temperature, sun hours, evaporation, and relative humidity are the meteorological parameters best correlated to the behavior of Plantago pollen grains. In general, the years with low pollen concentrations correspond to the years with less precipitation or higher temperatures. We calculated the approximate Plantago flowering dates using the cumulative sum of daily maximum temperatures and compared them with the real bloom dates. The differences obtained were 4 days in 2009, 3 days in 2010, and 1 day in 2011 considering the complete period of pollination. PMID:24337493

  20. Modern pollen deposition in Long Island Sound

    USGS Publications Warehouse

    Beuning, Kristina R.M.; Fransen, Lindsey; Nakityo, Berna; Mecray, Ellen L.; Bucholtz ten Brink, Marilyn R.

    2000-01-01

    Palynological analyses of 20 surface sediment samples collected from Long Island Sound show a pollen assemblage dominated by Carya, Betula, Pinus, Quercus, Tsuga, and Ambrosia, as is consistent with the regional vegetation. No trends in relative abundance of these pollen types occur either from west to east or associated with modern riverine inputs throughout the basin. Despite the large-scale, long-term removal of fine-grained sediment from winnowed portions of the eastern Sound, the composition of the pollen and spore component of the sedimentary matrix conforms to a basin-wide homogeneous signal. These results strongly support the use of select regional palynological boundaries as chronostratigraphic tools to provide a framework for interpretation of the late glacial and Holocene history of the Long Island Sound basin sediments.

  1. A laboratory assessment of the Waveband Integrated Bioaerosol Sensor (WIBS-4) using individual samples of pollen and fungal spore material

    NASA Astrophysics Data System (ADS)

    Healy, David A.; O'Connor, David J.; Burke, Aoife M.; Sodeau, John R.

    2012-12-01

    A Bioaerosol sensing instrument referred to as WIBS-4, designed to continuously monitor ambient bioaerosols on-line, has been used to record a multiparameter “signature” from each of a number of Primary Biological Aerosol Particulate (PBAP) samples found in air. These signatures were obtained in a controlled laboratory environment and are based on the size, asymmetry (“shape”) and auto-fluorescence of the particles. Fifteen samples from two separate taxonomic ranks (kingdoms), Plantae (×8) and Fungi (×7) were individually introduced to the WIBS-4 for measurement along with two non-fluorescing chemical solids, common salt and chalk. Over 2000 individual-particle measurements were recorded for each sample type and the ability of the WIBS spectroscopic technique to distinguish between chemicals, pollen and fungal spore material was examined by identifying individual PBAP signatures. The results obtained show that WIBS-4 could potentially be a very useful analytical tool for distinguishing between natural airborne PBAP samples, such as the fungal spores and may potentially play an important role in detecting and discriminating the toxic fungal spore, Aspergillus fumigatus, from others in real-time. If the sizing range of the commercial instrument was customarily increased and permitted to operate simultaneously in its two sizing ranges, pollen and spores could potentially be discriminated between. The data also suggest that the gain setting sensitivity on the detector would also have to be reduced by a factor >5, to routinely detect, in-range fluorescence measurements for pollen samples.

  2. Satellite Phenology Observations Inform Peak Season of Allergenic Grass Pollen Aerobiology across Two Continents

    NASA Astrophysics Data System (ADS)

    Huete, A. R.; Devadas, R.; Davies, J.

    2015-12-01

    Pollen exposure and prevalence of allergenic diseases have increased in many parts of the world during the last 30 years, with exposure to aeroallergen grass pollen expected to intensify with climate change, raising increased concerns for allergic diseases. The primary contributing factors to higher allergenic plant species presence are thought to be climate change, land conversion, and biotic mixing of species. Conventional methods for monitoring airborne pollen are hampered by a lack of sampling sites and heavily rely on meteorology with less attention to land cover updates and monitoring of key allergenic species phenology stages. Satellite remote sensing offers an alternative method to overcome the restrictive coverage afforded by in situ pollen networks by virtue of its synoptic coverage and repeatability of measurements that enable timely updates of land cover and land use information and monitoring landscape dynamics and interactions with human activity and climate. In this study, we assessed the potential of satellite observations of urban/peri-urban environments to directly inform landscape conditions conducive to pollen emissions. We found satellite measurements of grass cover phenological evolution to be highly correlated with in situ aerobiological grass pollen concentrations in five urban centres located across two hemispheres (Australia and France). Satellite greenness data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were found to be strongly synchronous with grass pollen aerobiology in both temperate grass dominated sites (France and Melbourne), as well as in Sydney, where multiple pollen peaks coincided with the presence of subtropical grasses. Employing general additive models (GAM), the satellite phenology data provided strong predictive capabilities to inform airborne pollen levels and forecast periods of grass pollen emissions at all five sites. Satellite phenology offer promising opportunities of improving public health risk

  3. Large Eddy Simulation and Field Experiments of Pollen Transport in the Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Chamecki, M.; Meneveau, C.; Parlange, M. B.; van Hout, R.

    2006-12-01

    Dispersion of airborne pollen by the wind has been a subject of interest for botanists and allergists for a long time. More recently, the development of genetically modified crops and questions about cross-pollination and subsequent contamination of natural plant populations has brought even more interest to this field. A critical question is how far from the source field pollen grains will be advected. Clearly the answer depends on the aerodynamic properties of the pollen, geometrical properties of the field, topography, local vegetation, wind conditions, atmospheric stability, etc. As a consequence, field experiments are well suited to provide some information on pollen transport mechanisms but are limited to specific field and weather conditions. Numerical simulations do not have this drawback and can be a useful tool to study pollen dispersal in a variety of configurations. It is well known that the dispersion of particles in turbulent fields is strongly affected by the large scale coherent structures. Large Eddy Simulation (LES) is a technique that allows us to study the typical distances reached by pollen grains and, at the same time, resolve the larger coherent structures present in the atmospheric boundary layer. The main objective of this work is to simulate the dispersal of pollen grains in the atmospheric surface layer using LES. Pollen concentrations are simulated by an advection-diffusion equation including gravitational settling. Of extreme importance is the specification of the bottom boundary conditions characterizing the pollen source over the canopy and the deposition process everywhere else. In both cases we make use of the theoretical profile for suspended particles derived by Kind (1992). Field experiments were performed to study the applicability of the theoretical profile to pollen grains and the results are encouraging. Airborne concentrations as well as ground deposition from the simulations are compared to experimental data to validate the

  4. Climate change and its impact on birch pollen quantities and the start of the pollen season an example from Switzerland for the period 1969-2006

    NASA Astrophysics Data System (ADS)

    Frei, Thomas; Gassner, Ewald

    2008-09-01

    As published by the Intergovernmental Panel on Climate Change (IPCC) global warming is a reality and its impact is huge like the increase of extreme weather events, glacier recession, sea level rise and also effects on human health. Among them allergies to airborne pollen might increase or change in pattern due to the invasion of new allergic plants or due to different behavior of plants like earlier flowering. In this study we used the longest Swiss airborne pollen data set to examine the influence of the temperature increase on the time of flowering. In the case of Basel, where pollen data for 38 years are available, it was shown that due to a temperature increase the start of flowering in the case of birch occurred about 15 days earlier. Apart from a shift of the start of the flowering there is also a trend towards higher annual birch pollen quantities and an increase of the highest daily mean pollen concentrations. Due to global warming and because symptoms may appear earlier in the year people suffering from a pollen allergy might face a new unaccustomed situation.

  5. Monarch larvae sensitivity to Bacillus thuringiensis- purified proteins and pollen

    PubMed Central

    Hellmich, Richard L.; Siegfried, Blair D.; Sears, Mark K.; Stanley-Horn, Diane E.; Daniels, Michael J.; Mattila, Heather R.; Spencer, Terrence; Bidne, Keith G.; Lewis, Leslie C.

    2001-01-01

    Laboratory tests were conducted to establish the relative toxicity of Bacillus thuringiensis (Bt) toxins and pollen from Bt corn to monarch larvae. Toxins tested included Cry1Ab, Cry1Ac, Cry9C, and Cry1F. Three methods were used: (i) purified toxins incorporated into artificial diet, (ii) pollen collected from Bt corn hybrids applied directly to milkweed leaf discs, and (iii) Bt pollen contaminated with corn tassel material applied directly to milkweed leaf discs. Bioassays of purified Bt toxins indicate that Cry9C and Cry1F proteins are relatively nontoxic to monarch first instars, whereas first instars are sensitive to Cry1Ab and Cry1Ac proteins. Older instars were 12 to 23 times less susceptible to Cry1Ab toxin compared with first instars. Pollen bioassays suggest that pollen contaminants, an artifact of pollen processing, can dramatically influence larval survival and weight gains and produce spurious results. The only transgenic corn pollen that consistently affected monarch larvae was from Cry1Ab event 176 hybrids, currently <2% corn planted and for which re-registration has not been applied. Results from the other types of Bt corn suggest that pollen from the Cry1Ab (events Bt11 and Mon810) and Cry1F, and experimental Cry9C hybrids, will have no acute effects on monarch butterfly larvae in field settings. PMID:11559841

  6. Composition and Morphology of Major Particle Types from Airborne Measurements during ICE-T and PRADACS Field Studies

    NASA Astrophysics Data System (ADS)

    Venero, I. M.; Mayol-Bracero, O. L.; Anderson, J. R.

    2012-12-01

    As part of the Puerto Rican African Dust and Cloud Study (PRADACS) and the Ice in Clouds Experiment - Tropical (ICE-T), we sampled giant airborne particles to study their elemental composition, morphology, and size distributions. Samples were collected in July 2011 during field measurements performed by NCAR's C-130 aircraft based on St Croix, U.S Virgin Island. The results presented here correspond to the measurements done during research flight #8 (RF8). Aerosol particles with Dp > 1 um were sampled with the Giant Nuclei Impactor and particles with Dp < 1 um were collected with the Wyoming Inlet. Collected particles were later analyzed using an automated scanning electron microscope (SEM) and manual observation by field emission SEM. We identified the chemical composition and morphology of major particle types in filter samples collected at different altitudes (e.g., 300 ft, 1000 ft, and 4500ft). Results from the flight upwind of Puerto Rico show that particles in the giant nuclei size range are dominated by sea salt. Samples collected at altitudes 300 ft and 1000 ft showed the highest number of sea salt particles and the samples collected at higher altitudes (> 4000 ft) showed the highest concentrations of clay material. HYSPLIT back trajectories for all samples showed that the low altitude samples initiated in the free troposphere in the Atlantic Ocean, which may account for the high sea salt content and that the source of the high altitude samples was closer to the Saharan - Sahel desert region and, therefore, these samples possibly had the influence of African dust. Size distribution results for quartz and unreacted sea-salt aerosols collected on the Giant Nuclei Impactor showed that sample RF08 - 12:05 UTM (300 ft) had the largest size value (mean = 2.936 μm) than all the other samples. Additional information was also obtained from the Wyoming Inlet present at the C - 130 aircraft which showed that size distribution results for all particles were smaller in

  7. Precipitation signal in pollen rain from tropical forests, South India.

    PubMed

    Barboni, D; Bonnefille, R

    2001-04-01

    We have analyzed the pollen content of 51 surface soil samples collected in tropical evergreen and deciduous forests from the Western Ghats of South India sampled along a west to east gradient of decreasing rainfall (between 11 degrees 30-13 degrees 20'N and 75 degrees 30-76 degrees 30'E). Values of mean annual precipitation (Pann, mm/yr) have been calculated at each of the 51 sampling sites from a great number of meteorological stations in South India, using a method of data interpolation based on artificial neural network. Interpolated values at the pollen sites of Pann range from 1200 to 5555mm/yr, while mean temperature of the coldest month (MTCO) remains >15 degrees C and humidity factor (AET/PET, the actual evapotranspiration to potential evapotranspiration ratio) remains also included between 65 and 72%.Results are presented in the form of percentage pollen diagrams where samples are arranged according to increasing values of annual precipitation. They indicate that the climatic signal of rainfall is clearly evidenced by distinct pollen associations. Numerical analyses show that annual precipitation is an important parameter explaining the modern distribution of pollen taxa in this region. Pollen taxa markers of high rainfall (Pann >2500mm/yr) are Mallotus type, Elaeocarpus, Syzygium type, Olea dioica, Gnetum ula, and Hopea type, associated with Ixora type and Caryota. Pollen taxa markers of low rainfall (Pann <2500mm/yr) are Melastomataceae/Combretaceae, Maytenus type, Lagerstroemia and Grewia. The proportions of evergreen taxa and of arboreal taxa vary according to rainfall values. Indeed, when rainfall is <2500mm/yr, percentage of arboreal pollen (AP) is <50% and proportion of evergreen taxa is <20%. When rainfall exceeds 2500mm/yr, AP values average 70%, and proportion of evergreen taxa increases from 60 to 90%. Moreover, a good correlation between precipitation and proportion of evergreen taxa (0.85) presumes that precipitation can be estimated from

  8. Pollen Tube Discharge Completes the Process of Synergid Degeneration That Is Initiated by Pollen Tube-Synergid Interaction in Arabidopsis1[OPEN

    PubMed Central

    Leydon, Alexander R.; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Qin, Yuan; Johnson, Mark A.; Palanivelu, Ravishankar

    2015-01-01

    In flowering plant reproduction, pollen tube reception is the signaling system that results in pollen tube discharge, synergid degeneration, and successful delivery of male gametes (two sperm cells) to the site where they can fuse with female gametes (egg cell and central cell). Some molecules required for this complex and essential signaling exchange have been identified; however, fundamental questions about the nature of the interactions between the pollen tube and the synergid cells remain to be clarified. Here, we monitor pollen tube arrival, pollen tube discharge, and synergid degeneration in Arabidopsis (Arabidopsis thaliana) wild type and in male and female gametophytic mutants that disrupt development and function of the gametophytes. By combining assays used previously to study these interactions and an assay that facilitates simultaneous analysis of pollen tube discharge and synergid degeneration, we find that synergid degeneration could be initiated without pollen tube discharge. Our data support the hypothesis that pollen tube-synergid contact, or signaling via secreted molecules, initiates receptive synergid degeneration. We also find that when pollen tubes successfully burst, they always discharge into a degenerated synergid. In addition to this pollen tube-dependent promotion of synergid degeneration, we also show that a basal developmental pathway mediates synergid degeneration in the absence of pollination. Our results are consistent with the model that a complex set of interactions between the pollen tube and synergid cells promote receptive synergid degeneration. PMID:26229050

  9. A mechanistic modeling system for estimating large-scale emissions and transport of pollen and co-allergens

    NASA Astrophysics Data System (ADS)

    Efstathiou, Christos; Isukapalli, Sastry; Georgopoulos, Panos

    2011-04-01

    Allergic airway diseases represent a complex health problem which can be exacerbated by the synergistic action of pollen particles and air pollutants such as ozone. Understanding human exposures to aeroallergens requires accurate estimates of the spatial distribution of airborne pollen levels as well as of various air pollutants at different times. However, currently there are no established methods for estimating allergenic pollen emissions and concentrations over large geographic areas such as the United States. A mechanistic modeling system for describing pollen emissions and transport over extensive domains has been developed by adapting components of existing regional scale air quality models and vegetation databases. First, components of the Biogenic Emissions Inventory System (BEIS) were adapted to predict pollen emission patterns. Subsequently, the transport module of the Community Multiscale Air Quality (CMAQ) modeling system was modified to incorporate description of pollen transport. The combined model, CMAQ-pollen, allows for simultaneous prediction of multiple air pollutants and pollen levels in a single model simulation, and uses consistent assumptions related to the transport of multiple chemicals and pollen species. Application case studies for evaluating the combined modeling system included the simulation of birch and ragweed pollen levels for the year 2002, during their corresponding peak pollination periods (April for birch and September for ragweed). The model simulations were driven by previously evaluated meteorological model outputs and emissions inventories for the eastern United States for the simulation period. A semi-quantitative evaluation of CMAQ-pollen was performed using tree and ragweed pollen counts in Newark, NJ for the same time periods. The peak birch pollen concentrations were predicted to occur within two days of the peak measurements, while the temporal patterns closely followed the measured profiles of overall tree pollen

  10. Characterization of pollen and bacterial community composition in brood provisions of a small carpenter bee.

    PubMed

    McFrederick, Quinn S; Rehan, Sandra M

    2016-05-01

    Many insects obtain gut microbes from their diet, but how a mother's foraging patterns influence the microbes found in her offspring's food remains an open question. To address this gap, we studied a bee that forages for pollen from multiple species of plants and may therefore acquire diverse bacteria from different plants. We tested the hypothesis that pollen diversity correlates with bacterial diversity by simultaneously characterizing these two communities in bee brood provisions for the first time. We used deep sequencing of the plant RBCL gene and the bacterial 16S rRNA gene to characterize pollen and bacterial diversity. We then tested for associations between pollen and bacterial species richness and community composition, as well as co-occurrence of specific bacteria and pollen types. We found that both pollen and bacterial communities were extremely diverse, indicating that mother bees visit a wide variety of flowers for pollen and nectar and subsequently bring a diversity of microbes back into their nests. Pollen and bacterial species richness and community composition, however, were not correlated. Certain pollen types significantly co-occurred with the most proportionally abundant bacteria, indicating that the plants these pollen types came from may serve as reservoirs for these bacteria. Even so, the overall diversity of these communities appears to mask these associations at a broader scale. Further study of these pollen and bacteria associations will be important for understanding the complicated relationship between bacteria and wild bees. PMID:26945527

  11. Quantitative Climate Reconstruction Based On Pollen Data From Russian Arctic

    NASA Astrophysics Data System (ADS)

    Tarasov, P. E.; Andreev, A. A.; Hubberten, H.-W.

    Three different statistical approaches have been tested to get quantitative reconstruc- tion of the Late Quaternary climate fluctuations in the Russian Arctic using surface pollen data set from the northern Eurasia. An information-statistical method (Kli- manov, 1984) is based on the statistical correlations between the total pollen and spore abundance, as well as relative values of 14 most common tree and shrub pollen taxa. Over 800 recent pollen spectra from 220 sites across the northern Eurasia were used to worked out the method. It has been applied to the fossil pollen records from the Rus- sian Arctic (e.g. Andreev and Klimanov, 2000). However, we found that it has a clear limitation in reconstruction of climate from spectra with low percentages of arboreal pollen. A plant functional type (PFT) method gives better results in reconstruction of modern climate in the forest-tundra and tundra zone (Tarasov et al., 1999). However, transfer functions between modern PFT scores and climate were also derived from the data set with a limited number of Russian Arctic pollen spectra. A best modern ana- logues method (Guiot, 1990) have been applied to the recently updated modern pollen data set, including over 1100 pollen spectra from the areas of the former USSR and Mongolia. Totally, 77 arboreal and non-arboreal pollen taxa were included in the anal- ysis. Modern climate variables at the pollen sampling sites have been calculated from the climate database with precise topography (W. Cramer, pers. comm.). We found that the mean July temperature and the sum of the mean daily temperatures above 5zC (growing-degree-days) can be reconstructed in the Russian Arctic with high accuracy. However, pollen spectra from Russian Arctic do not show a clear response to changes in the mean January temperature and in moisture index. Among the other tested vari- ables annual precipitation and runoff (annual precipitation minus evaporation) were reconstructed from the modern pollen spectra

  12. Pollen calendar of the city of Salamanca (Spain). Aeropalynological analysis for 1981-1982 and 1991-1992.

    PubMed

    Hernández Prieto, M; Lorente Toledano, F; Romo Cortina, A; Dávila González, I; Laffond Yges, E; Calvo Bullón, A

    1998-01-01

    We report a study on the contents of airborne pollen in the city of Salamanca (Spain) aimed at establishing a pollen calendar for the city for the yearly periods of maximum concentrations, relating these with quantifiable atmospheric variables over two two-year periods with an interval of 10 years between them: 1981-82 and 1991-92. The pollen was captured with Burkard spore-traps, based on Hirst's volumetric method. Determinations were made daily and were used to make preparations, previously stained with basic fuscin, for study under light microscopy at x 1,000 magnification. 946 preparations were analyzed, corresponding to the same number of days distributed over 150 weeks of the periods studied. The results afforded the identification of 48 different types of pollen grain: Grasses (Poaceae), Olea europea (olive), Quercus rotundifolia (Holm-oak), other Quercus spp. (Q. pyrenaica, Q. suber, Q. faginea, etc.), Cupressaceae (Cupressus sempervivens, C. arizonica, Juniperus communis etc.), Plantago (Plantago lanceolata, Plantago media, etc.), Pinaceae (Pinus communis, Abies alba, etc.), Rumex sp. (osier), Urtica dioica (nettle), Parietaria (Parietaria officinalis, P. judaica), Chenopodio-Amaranthaceae (Chenopodium sp., Amaranthus sp., Salsola kali, etc.), Artemisia vulgaris (Artemisia), other Compositae (Taraxacum officinalis, Hellianthus sp. etc.), Castanea sativa (Chestnut), Ligustrum sp. (privet), Betula sp. (birch), Alnus sp. (common alder), Fraxinus sp (ash), Populus sp. (poplar), Salix sp. (willow), Ulmus sp. (elm), Platanus sp. (plantain, plane), Carex sp. (sweet flag), Erica sp. (common heather), Leguminosae or Fabaceae:--Papillionaceae (Medicago sp.; Cercis sp., Robina sp.)--Cesalpinoideae Acacia sp. (Acacia),--Mimosoideae: Sophora japonica, Umbelliferae (Foeniculum sp., Cirsium sp., etc.), Centaurea sp., Cistus sp. (rock rose), Typha sp (bulrush), Mirtaceae (Myrtus communis), Juglans regia (Walnut), Galium verum, Filipendula sp. (spirea/drop wort), Rosaceae

  13. An analysis of modern pollen rain from the Maya lowlands of northern Belize

    USGS Publications Warehouse

    Bhattacharya, T.; Beach, T.; Wahl, D.

    2011-01-01

    In the lowland Maya area, pollen records provide important insights into the impact of past human populations and climate change on tropical ecosystems. Despite a long history of regional paleoecological research, few studies have characterized the palynological signatures of lowland ecosystems, a fact which lowers confidence in ecological inferences made from palynological data. We sought to verify whether we could use pollen spectra to reliably distinguish modern ecosystem types in the Maya lowlands of Central America. We collected 23 soil and sediment samples from eight ecosystem types, including upland, riparian, secondary, and swamp (bajo) forests; pine savanna; and three distinct wetland communities. We analyzed pollen spectra with non-metric multidimensional scaling (NMDS), and found significant compositional differences in ecosystem types' pollen spectra. Forested sites had spectra dominated by Moraceae/Urticaceae pollen, while non-forested sites had significant portions of Poaceae, Asteraceae, and Amaranthaceae pollen. Upland, bajo, and riparian forest differed in representation of Cyperaceae, Bactris-type, and Combretaceae/Melastomataceae pollen. High percentages of pine (Pinus), oak (Quercus), and the presence of Byrsonima characterized pine savanna. Despite its limited sample size, this study provides one of the first statistical analyses of modern pollen rain in the Maya lowlands. Our results show that pollen assemblages can accurately reflect differences between ecosystem types, which may help refine interpretations of pollen records from the Maya area. ?? 2010 Elsevier B.V.

  14. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia.

    PubMed

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m(3)) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m(3). Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration. PMID:22410823

  15. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    NASA Astrophysics Data System (ADS)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  16. Transport and radiative impacts of atmospheric pollen using online, observation-based emissions

    NASA Astrophysics Data System (ADS)

    Wozniak, M. C.; Steiner, A. L.; Solmon, F.; Li, Y.

    2015-12-01

    Atmospheric pollen emitted from trees and grasses exhibits both a high temporal variability and a highly localized spatial distribution that has been difficult to quantify in the atmosphere. Pollen's radiative impact is also not quantified because it is neglected in climate modeling studies. Here we couple an online, meteorological active pollen emissions model guided by observations of airborne pollen to understand the role of pollen in the atmosphere. We use existing pollen counts from 2003-2008 across the continental U.S. in conjunction with a tree database and historical meteorological data to create an observation-based phenological model that produces accurately scaled and timed emissions. These emissions are emitted and transported within the regional climate model (RegCM4) and the direct radiative effect is calculated. Additionally, we simulate the rupture of coarse pollen grains into finer particles by adding a second size mode for pollen emissions, which contributes to the shortwave radiative forcing and also has an indirect effect on climate.

  17. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Specifications and preliminary design of an Airborne Oceanographic Lidar (AOL) system, which is to be constructed for installation and used on a NASA Wallops Flight Center (WFC) C-54 research aircraft, are reported. The AOL system is to provide an airborne facility for use by various government agencies to demonstrate the utility and practicality of hardware of this type in the wide area collection of oceanographic data on an operational basis. System measurement and performance requirements are presented, followed by a description of the conceptual system approach and the considerations attendant to its development. System performance calculations are addressed, and the system specifications and preliminary design are presented and discussed.

  18. Fraxinus pollen and allergen concentrations in Ourense (South-western Europe).

    PubMed

    Vara, A; Fernández-González, M; Aira, M J; Rodríguez-Rajo, F J

    2016-05-01

    In temperate zones of North-Central Europe the sensitization to ash pollen is a recognized problem, also extended to the Northern areas of the Mediterranean basin. Some observations in Switzerland suggest that ash pollen season could be as important as birch pollen period. The allergenic significance of this pollen has been poorly studied in Southern Europe as the amounts of ash pollen are low. Due to the high degree of family relationship with the olive pollen major allergen (backed by a sequence identity of 88%), the Fraxinus pollen could be a significant cause of early respiratory allergy in sensitized people to olive pollen as consequence of cross-reactivity processes. Ash tree flowers in the Northwestern Spain during the winter months. The atmospheric presence of Ole e 1-like proteins (which could be related with the Fra a 1 presence) can be accurately detected using Ole e 1 antibodies. The correlation analysis showed high Spearman correlation coefficients between pollen content and rainfall (R(2)=-0.333, p<0.01) or allergen concentration and maximum temperature (R(2)=-0.271, p<0.01). In addiction CCA analysis showed not significant differences (p<0.05) between the component 1 and 2 variables. PCFA analysis plots showed that the allergen concentrations are related to the presence of the Fraxinus pollen in the air, facilitating the wind speed its submicronic allergen proteins dispersion. In order to forecast the Fraxinus allergy risk periods, two regression equations were developed with Adjusted R(2) values around 0.48-0.49. The t-test for dependent samples shows no significant differences between the observed data and the estimated by the equations. The combination of the airborne pollen content and the allergen quantification must be assessed in the epidemiologic study of allergic respiratory diseases. PMID:26901381

  19. The Arabidopsis KINβγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen.

    PubMed

    Gao, Xin-Qi; Liu, Chang Zhen; Li, Dan Dan; Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-07-01

    Pollen-stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen-stigma interactions is poorly understood. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINβγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinβγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinβγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinβγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinβγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINβγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen-stigma interactions during pollination. PMID:27472382

  20. Class XI Myosins Move Specific Organelles in Pollen Tubes and Are Required for Normal Fertility and Pollen Tube Growth in Arabidopsis1[OPEN

    PubMed Central

    Madison, Stephanie L.; Buchanan, Matthew L.; Glass, Jeremiah D.; McClain, Tarah F.; Park, Eunsook; Nebenführ, Andreas

    2015-01-01

    Pollen tube growth is an essential aspect of plant reproduction because it is the mechanism through which nonmotile sperm cells are delivered to ovules, thus allowing fertilization to occur. A pollen tube is a single cell that only grows at the tip, and this tip growth has been shown to depend on actin filaments. It is generally assumed that myosin-driven movements along these actin filaments are required to sustain the high growth rates of pollen tubes. We tested this conjecture by examining seed set, pollen fitness, and pollen tube growth for knockout mutants of five of the six myosin XI genes expressed in pollen of Arabidopsis (Arabidopsis thaliana). Single mutants had little or no reduction in overall fertility, whereas double mutants of highly similar pollen myosins had greater defects in pollen tube growth. In particular, myo11c1 myo11c2 pollen tubes grew more slowly than wild-type pollen tubes, which resulted in reduced fitness compared with the wild type and a drastic reduction in seed set. Golgi stack and peroxisome movements were also significantly reduced, and actin filaments were less organized in myo11c1 myo11c2 pollen tubes. Interestingly, the movement of yellow fluorescent protein-RabA4d-labeled vesicles and their accumulation at pollen tube tips were not affected in the myo11c1 myo11c2 double mutant, demonstrating functional specialization among myosin isoforms. We conclude that class XI myosins are required for organelle motility, actin organization, and optimal growth of pollen tubes. PMID:26358416

  1. Elevation of Pollen Mitochondrial DNA Copy Number by WHIRLY2: Altered Respiration and Pollen Tube Growth in Arabidopsis.

    PubMed

    Cai, Qiang; Guo, Liang; Shen, Zhao-Rui; Wang, Dan-Yang; Zhang, Quan; Sodmergen

    2015-09-01

    In plants, the copy number of the mitochondrial DNA (mtDNA) can be much lower than the number of mitochondria. The biological significance and regulatory mechanisms of this phenomenon remain poorly understood. Here, using the pollen vegetative cell, we examined the role of the Arabidopsis (Arabidopsis thaliana) mtDNA-binding protein WHIRLY2 (AtWHY2). AtWHY2 decreases during pollen development, in parallel with the rapid degradation of mtDNA; to examine the importance of this decrease, we used the pollen vegetative cell-specific promoter Lat52 to express AtWHY2. The transgenic plants (LWHY2) had very high mtDNA levels in pollen, more than 10 times more than in the wild type (ecotype Columbia-0). LWHY2 plants were fertile, morphologically normal, and set seeds; however, reciprocal crosses with heterozygous plants showed reduced transmission of LWHY2-1 through the male and slower growth of LWHY2-1 pollen tubes. We found that LWHY2-1 pollen had significantly more reactive oxygen species and less ATP compared with the wild type, indicating an effect on mitochondrial respiration. These findings reveal that AtWHY2 affects mtDNA copy number in pollen and suggest that low mtDNA copy numbers might be the normal means by which plant cells maintain mitochondrial genetic information. PMID:26195569

  2. Pollen Dispersion, Pollen Viability and Pistil Receptivity in Leymus chinensis

    PubMed Central

    HUANG, ZEHAO; ZHU, JINMAO; MU, XIJIN; LIN, JINXING

    2004-01-01

    • Background and Aims Leymus chinensis is an economically and ecologically important grass that is widely distributed across eastern areas of the Eurasian steppe. A major problem facing its propagation by man is its low sexual reproductivity. The causes of low fecundity are uncertain, largely because many aspects of the reproductive biology of this species remained unknown or incomplete. This study aims to address some of these issues. • Methods Pollen dispersion, pollen viability, pollen longevity and pistil receptivity were studied in a representative, natural population of L. chinensis growing in Inner Mongolia. • Key Results Flowering of L. chinensis occurred at the end of June and lasted for 5 d. Pollination peaked between 1600 h and 1700 h, and about 56·1 % of the total pollen grains were released at this time. Pollen density was highest towards the middle of flowering spikes and lowest at the bottom over the 5 d measurement period. Pollen viability (62·4 %) assessed using TTC was more accurate than using IKI (85·6 %); 50 % of pollen arriving on stigmas germinated. Pollen remained viable for only 3 h and the pollen : ovule ratio was 79 333 : 1. Pistil receptivity lasted for only 3 h and, overall, 86·7 % of pistils were pollinated. Within the spike, the relative fecundity of different positions was middle > lower > upper throughout the period of pollination; daily variation of fecundity was similar to that of the pollen flow. The spikes that opened on the day of highest pollen density exhibited the highest fecundity (36·0 %). No seeds were produced by self‐pollination. • Conclusions The data suggest that low pollen viability, short pollen longevity and short pistil receptivity all appear to contribute to the low seed production typical of this important forage crop. PMID:14744707

  3. [The effect of climate change on pollen allergy in the Netherlands].

    PubMed

    de Weger, Letty A; Hiemstra, Pieter S

    2009-01-01

    Climate change can exert a range of effects on pollen, which might have consequences for pollen-allergic patients. New allergenic pollen types might appear in the Netherlands, like common ragweed and olive, which result in allergy patients developing allergies that scarcely occur in the Netherlands at present. Trees, such as birches and planes, might produce larger quantities of pollen, which could result in more severe symptoms. The pollen season might become longer thereby extending the period in which patients suffer from allergy symptoms. This extension of the pollen season could be due to a prolonged flowering period of certain species, e.g. grasses, or the appearance of new species that flower in late summer, e.g. common ragweed. Climate change could cause an increase in heavy thunderstorms on summer days in the grass pollen season, which are known to increase the chance of asthma exacerbations. PMID:20025786

  4. Arabidopsis thaliana CML25 mediates the Ca(2+) regulation of K(+) transmembrane trafficking during pollen germination and tube elongation.

    PubMed

    Wang, Shuang-Shuang; Diao, Wen-Zhu; Yang, Xue; Qiao, Zhu; Wang, Mei; Acharya, Biswa R; Zhang, Wei

    2015-11-01

    The concentration alteration of cytosolic-free calcium ([Ca(2+) ]cyt ) is a well-known secondary messenger in plants and plays important roles during pollen grain germination and tube elongation. Here we demonstrate that CML25, a member of calmodulin-like proteins, has Ca(2+) -binding activity and plays a role in pollen grain germination, tube elongation and seed setting. CML25 transcript was abundant in mature pollen grains and pollen tubes, and its product CML25 protein was primarily directed to the cytoplasm. Two independent CML25 loss-of-function T-DNA insertion mutants suffered a major reduction in both the rate of pollen germination and the elongation of the pollen tube. Also, pollen grains of cml25 mutants were less sensitive to the external K(+) and Ca(2+) concentration than wild-type pollen. The disruption of CML25 increased the [Ca(2+) ]cyt in both the pollen grain and the pollen tube, which in turn impaired the Ca(2+) -dependent inhibition of whole-cell inward K(+) currents in protoplasts prepared from these materials (pollen grain and pollen tube). Complementation of cml25-1 mutant resulted in the recovery of wild-type phenotype. Our findings indicate that CML25 is an important transducer in the Ca(2+) -mediated regulation of K(+) influx during pollen germination and tube elongation. PMID:25923414

  5. Effect of repetitive mowing on common ragweed (Ambrosia artemisiifolia L.) pollen and seed production.

    PubMed

    Simard, Marie-Josée; Benoit, Diane Lyse

    2011-01-01

    Ambrosia artemisiifolia L (common ragweed) is a familiar roadside weed in southern Québec (Canada) that produces large amounts of airborne pollen responsible for multiple rhino-conjunctivitis (hay fever) cases. As roadside weeds are increasingly controlled by mowing alone, the effect of a mowing treatment on pollen production was evaluated. Ambrosia artemisiifolia plants were grown in a greenhouse at 4 densities (1, 3, 6 and 12 plants per 314 cm(2) pot) and either left intact or mowed (10 cm from the ground) when the plants reached 25 cm in height, i.e. twice during the life cycle of this annual plant. Pollen production per male inflorescence was collected in open-top bags and counted. Inflorescence mass, length, location on the plant and date of anthesis onset was noted. Above-ground plant biomass and seed production was also evaluated. Mowed plants produced less pollen per unit of inflorescence length than intact plants. Pollen production per plant was reduced by a factor of 8.84 by the double mowing treatment, while viable seed production per plant was reduced by a factor of 4.66, irrespective of density. Mowing twice has the potential to reduce airborne pollen loads but Ambrosia artemisiifolia seed banks are unlikely to be depleted by this management strategy. PMID:21736270

  6. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  7. Trans-disciplinary research in synthesis of grass pollen aerobiology and its importance for respiratory health in Australasia.

    PubMed

    Davies, Janet M; Beggs, Paul J; Medek, Danielle E; Newnham, Rewi M; Erbas, Bircan; Thibaudon, Michel; Katelaris, Connstance H; Haberle, Simon G; Newbigin, Edward J; Huete, Alfredo R

    2015-11-15

    Grass pollen is a major trigger for allergic rhinitis and asthma, yet little is known about the timing and levels of human exposure to airborne grass pollen across Australasian urban environments. The relationships between environmental aeroallergen exposure and allergic respiratory disease bridge the fields of ecology, aerobiology, geospatial science and public health. The Australian Aerobiology Working Group comprised of experts in botany, palynology, biogeography, climate change science, plant genetics, biostatistics, ecology, pollen allergy, public and environmental health, and medicine, was established to systematically source, collate and analyse atmospheric pollen concentration data from 11 Australian and six New Zealand sites. Following two week-long workshops, post-workshop evaluations were conducted to reflect upon the utility of this analysis and synthesis approach to address complex multidisciplinary questions. This Working Group described i) a biogeographically dependent variation in airborne pollen diversity, ii) a latitudinal gradient in the timing, duration and number of peaks of the grass pollen season, and iii) the emergence of new methodologies based on trans-disciplinary synthesis of aerobiology and remote sensing data. Challenges included resolving methodological variations between pollen monitoring sites and temporal variations in pollen datasets. Other challenges included "marrying" ecosystem and health sciences and reconciling divergent expert opinion. The Australian Aerobiology Working Group facilitated knowledge transfer between diverse scientific disciplines, mentored students and early career scientists, and provided an uninterrupted collaborative opportunity to focus on a unifying problem globally. The Working Group provided a platform to optimise the value of large existing ecological datasets that have importance for human respiratory health and ecosystems research. Compilation of current knowledge of Australasian pollen aerobiology

  8. Airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-06-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  9. PECTIN METHYLESTERASE48 Is Involved in Arabidopsis Pollen Grain Germination1[OPEN

    PubMed Central

    Leroux, Christelle; Bouton, Sophie; Kiefer-Meyer, Marie-Christine; Fabrice, Tohnyui Ndinyanka; Mareck, Alain; Guénin, Stéphanie; Fournet, Françoise; Ringli, Christoph; Pelloux, Jérôme; Driouich, Azeddine; Lerouge, Patrice; Lehner, Arnaud; Mollet, Jean-Claude

    2015-01-01

    Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme48−/− pollen grains. In contrast, the PME activity was lower in pme48−/−, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme48−/− with the optimum germination medium supplemented with 2.5 mm calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca2+ necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination. PMID:25524442

  10. Fungal spores and pollen in particulate matter collected during agricultural activities in the Po Valley (Italy).

    PubMed

    Telloli, Chiara; Chicca, Milvia; Leis, Marilena; Vaccaro, Carmela

    2016-08-01

    Airborne particulate matter (PM) containing fungal spores and pollen grains was sampled within a monitoring campaign of wheat threshing, plowing and sowing agricultural operations. Fungal spores and pollen grains were detected and identified on morphological basis. No studies were previously available about fungal spore and pollen content in agricultural PM in the Po Valley. Sampling was conducted in a Po Valley farmland in Mezzano (Ferrara, Italy). The organic particles collected were examined by scanning electron microscopy with energy dispersive X-ray spectrometer. Fungal spores and pollen grains were identified when possible at the level of species. The most frequent components of the organic particles sampled were spores of Aspergillus sp., which could represent a risk of developing allergies and aspergillosis for crop farmers. PMID:27521955

  11. Atmospheric solids analysis probe mass spectrometry for the rapid identification of pollens and semi-quantification of flavonoid fingerprints

    DOE PAGESBeta

    Xiao, Xiaoyin; Miller, Lance L.; Parchert, Kylea J.; Hayes, Dulce; Hochrein, James M.

    2016-06-08

    From allergies to plant reproduction, pollens have important impacts on the health of human and plant populations, yet identification of pollen grains remains difficult and time-consuming. Low-volatility flavonoids generated from pollens cannot be easily characterized and quantified with current analytical techniques. Here we demonstrate the novel use of atmospheric solids analysis probe mass spectrometry (ASAP-MS) for the characterization of flavonoids in pollens. Flavonoid patterns were generated for pollens collected from different plant types (trees and bushes) in addition to bee pollens from distinct geographic regions. Standard flavonoids (kaempferol and rhamnazin) and those produced from pollens were compared and assessed withmore » ASAP-MS using low-energy collision MS/MS. Results for a semi-quantitative method for assessing the amount of a flavonoid in pollens are also presented.« less

  12. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks.

    PubMed

    Emer, Carine; Vaughan, Ian P; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  13. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks

    PubMed Central

    Emer, Carine; Vaughan, Ian P.; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  14. Atmospheric Poaceae pollen frequencies and associations with meteorological parameters in Brisbane, Australia: a 5-year record, 1994-1999

    NASA Astrophysics Data System (ADS)

    Green, Brett James; Dettmann, Mary; Yli-Panula, Eija; Rutherford, Shannon; Simpson, Rod

    Grass pollen is an important risk factor for allergic rhinitis and asthma in Australia and is the most prevalent pollen component of the aerospora of Brisbane, accounting for 71.6% of the annual airborne pollen load. A 5-year (June 1994-May 1999) monitoring program shows the grass pollen season to occur during the summer and autumn months (December-April), however the timing of onset and intensity of the season vary from year to year. During the pollen season, Poaceae counts exceeding 30 grains m-3 were recorded on 244 days and coincided with maximum temperatures of 28.1 +/- 2.0 °C. In this study, statistical associations between atmospheric grass pollen loads and several weather parameters, including maximum temperature, minimum temperature and precipitation, were investigated. Spearman's correlation analysis demonstrated that daily grass pollen counts were positively associated (P < 0.0001) with maximum and minimum temperature during each sampling year. Precipitation, although considered a less important daily factor (P < 0.05), was observed to remove pollen grains from the atmosphere during significant periods of rainfall. This study provides the first insight into the influence of meteorological variables, in particular temperature, on atmospheric Poaceae pollen counts in Brisbane. An awareness of these associations is critical for the prevention and management of allergy and asthma for atopic individuals within this region.

  15. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G.

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6 %-248 %. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions.

  16. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States.

    PubMed

    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6%-248%. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions. PMID:23793955

  17. Grass pollen hypersensitivity in mice

    PubMed Central

    McCaskill, A. C.; Hosking, C. S.; Hill, D. J.

    1982-01-01

    Mice were sensitized by intranasal administration of ryegrass pollen. Subsequent nasal challenge with pollen extract led to a `shock' response peaking in severity 4 hr after challenge. Histological examination of lungs revealed the development of a pneumonitis which was most severe 3 days after challenge. ImagesFigure 2 PMID:7106842

  18. Comparison of modern pollen distribution between northern and southern South China Sea

    NASA Astrophysics Data System (ADS)

    Luo, C.; Chen, M.; Xiang, R.; Liu, J.; Zhang, L.; Lu, J.

    2013-12-01

    To understand pollen transport mechanic and terrigenous area is the base to explain pollen data correctly in Southern South China Sea (Fig.1). Based on Palynology analyzing the following preliminary conclusions are listed. 1. Air pollen differences between northern and southern South China Sea 15 air pollen samples were collected from northern part of the South China Sea from August to September 2011. 13 air pollen samples were collected from southern South China Sea in December 2011. It was found that the air pollen are different between northern and southern part of South China Sea: the pollen types in the north are more abundant than in the south, Ulmaceae, Monolete spore, Cyperaceae, Euphorbiaceae, Rubiaceae, Artemisia, Chenopodiaceae, Rosaceae, Labiatae occur only in the north, they do not occur or is just sporadic in the south. The total pollen number and concentration in the north is 10 times of the south, one of the reasons may be that the sampling season in the north is autumn with more flowering plants, the sampling season in the south is winter, with fewer flowering plants; the second reason might be that pollen and spore in autumn and winter are mainly spread by the winter wind, thus they reduce from north to south. 2. Pollen differences of the surface sediments between northern and southern South China Sea 14 samples were collected from surface sediments in the northern part of the South China Sea from August to October, 2011. 12 samples were collected from surface sediments in the southern part of the South China Sea from year 1997 to 2002. The differences of pollen characteristics from the surface sediments between northern and southern part of South China Sea are: pollen types and quantities in the north are richer than in south. There are Trilete spores (35-100%), Pinus (3-65%) in northern of SCS, with pollen concentration of 33-1031grain/g. There are only a small amount of Trilete-spore and Pinus pollen in southern of SCS. Pollen concentration in

  19. Quantitative interpretation of fossil pollen spectra: Dissimilarity coefficients and the method of modern analogs

    NASA Astrophysics Data System (ADS)

    Overpeck, J. T.; Webb, T.; Prentice, I. C.

    1985-01-01

    Dissimilarity coefficients measure the difference between multivariate samples and provide a quantitative aid to the identification of modern analogs for fossil pollen samples. How eight coefficients responded to differences among modern pollen samples from eastern North America was tested. These coefficients represent three different classes: (1) unweighted coefficients that are most strongly influenced by large-valued pollen types, (2) equal-weight coefficients that weight all pollen types equally but can be too sensitive to variations among rare types, and (3) signal0to-noise coefficients that are intermediate in their weighting of pollen types. The studies with modern pollen allowed definition of critical values for each coefficient, which, when not exceeded, indicate that two pollen samples originate from the same vegetation region. Dissimilarity coefficients were used to compare modern and fossil pollen samples, and modern samples so similar to fossil samples were found that most of three late Quaternary pollen diagrams could be "reconstructed" by substituting modern samples for fossil samples. When the coefficients indicated that the fossil spectra had no modern analogs, then the reconstructed diagrams did not match all aspects of the originals. No modern analogs existed for samples from before 9300 yr B.P. at Kirchner Marsh, Minnesota, and from before 11,000 yr B.P. at Wintergreen Lake, Michigan, but modern analogs existed for almost all Holocene samples from these two sites and Brandreth Bog. New York.

  20. Modelling past land use using archaeological and pollen data

    NASA Astrophysics Data System (ADS)

    Pirzamanbein, Behnaz; Lindström, johan; Poska, Anneli; Gaillard-Lemdahl, Marie-José

    2016-04-01

    Accurate maps of past land use are necessary for studying the impact of anthropogenic land-cover changes on climate and biodiversity. We develop a Bayesian hierarchical model to reconstruct the land use using Gaussian Markov random fields. The model uses two observations sets: 1) archaeological data, representing human settlements, urbanization and agricultural findings; and 2) pollen-based land estimates of the three land-cover types Coniferous forest, Broadleaved forest and Unforested/Open land. The pollen based estimates are obtained from the REVEALS model, based on pollen counts from lakes and bogs. Our developed model uses the sparse pollen-based estimations to reconstruct the spatial continuous cover of three land cover types. Using the open-land component and the archaeological data, the extent of land-use is reconstructed. The model is applied on three time periods - centred around 1900 CE, 1000 and, 4000 BCE over Sweden for which both pollen-based estimates and archaeological data are available. To estimate the model parameters and land use, a block updated Markov chain Monte Carlo (MCMC) algorithm is applied. Using the MCMC posterior samples uncertainties in land-use predictions are computed. Due to lack of good historic land use data, model results are evaluated by cross-validation. Keywords. Spatial reconstruction, Gaussian Markov random field, Fossil pollen records, Archaeological data, Human land-use, Prediction uncertainty

  1. Pollen assemblages as paleoenvironmental proxies in the Florida Everglades

    USGS Publications Warehouse

    Willard, D.A.; Weimer, L.M.; Riegel, W.L.

    2001-01-01

    Analysis of 170 pollen assemblages from surface samples in eight vegetation types in the Florida Everglades indicates that these wetland sub-environments are distinguishable from the pollen record and that they are useful proxies for hydrologic and edaphic parameters. Vegetation types sampled include sawgrass marshes, cattail marshes, sloughs with floating aquatics, wet prairies, brackish marshes, tree islands, cypress swamps, and mangrove forests. The distribution of these vegetation types is controlled by specific environmental parameters, such as hydrologic regime, nutrient availability, disturbance level, substrate type, and salinity; ecotones between vegetation types may be sharp. Using R-mode cluster analysis of pollen data, we identified diagnostic species groupings; Q-mode cluster analysis was used to differentiate pollen signatures of each vegetation type. Cluster analysis and the modern analog technique were applied to interpret vegetational and environmental trends over the last two millennia at a site in Water Conservation Area 3A. The results show that close modern analogs exist for assemblages in the core and indicate past hydrologic changes at the site, correlated with both climatic and land-use changes. The ability to differentiate marshes with different hydrologic and edaphic requirements using the pollen record facilitates assessment of relative impacts of climatic and anthropogenic changes on this wetland ecosystem on smaller spatial and temporal scales than previously were possible. ?? 2001 Elsevier Science B.V.

  2. A Taxonomic Reduced-Space Pollen Model for Paleoclimate Reconstruction

    NASA Astrophysics Data System (ADS)

    Wahl, E. R.; Schoelzel, C.

    2010-12-01

    Paleoenvironmental reconstruction from fossil pollen often attempts to take advantage of the rich taxonomic diversity in such data. Here, a taxonomically "reduced-space" reconstruction model is explored that would be parsimonious in introducing parameters needing to be estimated within a Bayesian Hierarchical Modeling context. This work involves a refinement of the traditional pollen ratio method. This method is useful when one (or a few) dominant pollen type(s) in a region have a strong positive correlation with a climate variable of interest and another (or a few) dominant pollen type(s) have a strong negative correlation. When, e.g., counts of pollen taxa a and b (r >0) are combined with pollen types c and d (r <0) to form ratios of the form (a + b) / (a + b + c + d), an appropriate estimation form is the binomial logistic generalized linear model (GLM). The GLM can readily model this relationship in the forward form, pollen = g(climate), which is more physically realistic than inverse models often used in paleoclimate reconstruction [climate = f(pollen)]. The specification of the model is: rnum Bin(n,p), where E(r|T) = p = exp(η)/[1+exp(η)], and η = α + β(T); r is the pollen ratio formed as above, rnum is the ratio numerator, n is the ratio denominator (i.e., the sum of pollen counts), the denominator-specific count is (n - rnum), and T is the temperature at each site corresponding to a specific value of r. Ecological and empirical screening identified the model (Spruce+Birch) / (Spruce+Birch+Oak+Hickory) for use in temperate eastern N. America. α and β were estimated using both "traditional" and Bayesian GLM algorithms (in R). Although it includes only four pollen types, the ratio model yields more explained variation ( 80%) in the pollen-temperature relationship of the study region than a 64-taxon modern analog technique (MAT). Thus, the new pollen ratio method represents an information-rich, reduced space data model that can be efficiently employed in

  3. Contribution of pollen to atmospheric ice nuclei concentrations

    NASA Astrophysics Data System (ADS)

    Hader, J. D.; Wright, T. P.; Petters, M. D.

    2014-06-01

    Recent studies have suggested that the ice-nucleating ability of some types of pollen is derived from non-proteinaceous macromolecules. These macromolecules may become dispersed by the rupturing of the pollen grain during wetting and drying cycles in the atmosphere. If true, this mechanism might prove to be a significant source of ice nuclei (IN) concentrations when pollen is present. Here we test this hypothesis by measuring ambient IN concentrations from the beginning to the end of the 2013 pollen season in Raleigh, North Carolina, USA. Air samples were collected using a swirling aerosol collector twice per week and the solutions were analysed for ice nuclei activity using a droplet freezing assay. Rainwater samples were collected at times when pollen grain number concentrations were near their maximum value and analysed with the drop-freezing assay to compare the potentially enhanced IN concentrations measured near the ground with IN concentrations found aloft. Ambient ice nuclei spectra, defined as the number of ice nuclei per volume of air as a function of temperature, are inferred from the aerosol collector solutions. No general trend was observed between ambient pollen grain counts and observed IN concentrations, suggesting that ice nuclei multiplication via pollen grain rupturing and subsequent release of macromolecules was not prevalent for the pollen types and meteorological conditions typically encountered in the southeastern US. A serendipitously sampled collection after a downpour provided evidence for a rain-induced IN burst with an observed IN concentration of approximately 30 per litre, a 30-fold increase over background concentrations at -20 °C. The onset temperature of freezing for these particles was approximately -12 °C, suggesting that the ice-nucleating particles were biological in origin.

  4. Contribution of pollen to atmospheric ice nuclei concentrations

    NASA Astrophysics Data System (ADS)

    Hader, J. D.; Wright, T. P.; Petters, M. D.

    2013-12-01

    Recent studies have suggested that the ice nucleating ability of some types of pollen is derived from non-proteinaceous macromolecules. These macromolecules may become dispersed by the rupturing of the pollen sac during wetting and drying cycles in the atmosphere. If true, this mechanism might prove to be a significant source of ice nuclei (IN) concentrations when pollen are present. Here we test this hypothesis by measuring ambient IN concentrations from the beginning to the end of the 2013 pollen season in Raleigh, North Carolina, USA. Air samples were collected using a swirling aerosol collector twice per week and the solutions were analysed for ice nuclei activity using a droplet freezing assay. Rainwater samples were collected at the peak of the pollen season and analysed with the drop freezing assay to compare the potentially enhanced IN concentrations measured near the ground with IN concentrations found aloft. Ambient ice nuclei spectra, defined as the number of ice nuclei per volume of air as a function of temperature, are inferred from the aerosol collector solutions. No general trend was observed between ambient pollen counts and observed IN concentrations, suggesting that ice nuclei multiplication via pollen sac rupturing and subsequent release of macromolecules was not prevalent for the pollen types and meteorological conditions typically encountered in the Southeastern US. A serendipitously sampled collection after a downpour provided evidence for a rain-induced IN burst with an observed IN concentration of approximately 30 per litre, a 30-fold increase over background concentrations at -20 °C. The onset temperature of freezing for these particles was approximately -12 °C, suggesting that the ice nucleating particles were biological in origin. The magnitude of the IN burst was significantly larger than previously observed, providing additional evidence to merit further investigation of a self-regulated feedback cycle between the atmosphere and

  5. Ambrosia artemisiifolia L. pollen simulations over the Euro-CORDEX domain: model description and emission calibration

    NASA Astrophysics Data System (ADS)

    liu, li; Solmon, Fabien; Giorgi, Filippo; Vautard, Robert

    2014-05-01

    Ragweed Ambrosia artemisiifolia L. is a highly allergenic invasive plant. Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma (D'Amato et al., 2007). In the context of the ATOPICA EU program we are studying the links between climate, land use and ecological changes on the ragweed pollen emissions and concentrations. For this purpose, we implemented a pollen emission/transport module in the RegCM4 regional climate model in collaboration with ATOPICA partners. The Abdus Salam International Centre for Theoretical Physics (ICTP) regional climate model, i.e. RegCM4 was adapted to incorporate the pollen emissions from (ORCHIDEE French) Global Land Surface Model and a pollen tracer model for describing pollen convective transport, turbulent mixing, dry and wet deposition over extensive domains, using consistent assumption regarding the transport of multiple species (Fabien et al., 2008). We performed two families of recent-past simulations on the Euro-Cordex domain (simulation for future condition is been considering). Hindcast simulations (2000~2011) were driven by the ERA-Interim re-analyses and designed to best simulate past periods airborne pollens, which were calibrated with parts of observations and verified by comparison with the additional observations. Historical simulations (1985~2004) were driven by HadGEM CMPI5 and designed to serve as a baseline for comparison with future airborne concentrations as obtained from climate and land-use scenarios. To reduce the uncertainties on the ragweed pollen emission, an assimilation-like method (Rouǐl et al., 2009) was used to calibrate release based on airborne pollen observations. The observations were divided into two groups and used for calibration and validation separately. A wide range of possible calibration coefficients were tested for each calibration station, making the bias between observations and simulations within an admissible value then

  6. Contribution of pollen to atmospheric ice nuclei concentrations

    NASA Astrophysics Data System (ADS)

    Petters, M. D.; Hader, J.; Wright, T.; McMeeking, G. R.

    2013-12-01

    Primary biological aerosol particles (PBAP) contribute to the concentrations of ice nuclei (IN) in the atmosphere. Laboratory studies have shown that pollen grains, a subset of PBAP, can serve as immersion mode ice nuclei at temperatures ranging from -9 to -25 deg C. At the peak of the pollen season pollen concentrations can reach surface-level concentrations exceeding 1 per liter of air. Furthermore, previous studies have suggested that the ice nucleating ability of some types of pollen is derived from non-proteinaceous macromolecules, which may become dispersed by the rupturing of the pollen sac during wetting and drying cycles. If true, this mechanism is expected to produce highly elevated IN concentrations at temperatures warmer than -25 deg C. Here we test this hypothesis by measuring ambient IN concentrations from the beginning to the end of the 2013 pollen season in Raleigh, North Carolina. Raleigh is surrounded by a dense mixed hardwood forest composed primarily of oak, hickory, and pine species. Air samples were collected using a swirling aerosol collector twice per week and the solution was analyzed for ice nuclei activity using a droplet freezing assay setup. Rainwater samples were collected during rain events at the peak of the pollen season and analyzed with the drop freezing assay to compare the potentially enhanced IN concentrations measured near the ground with IN concentrations found aloft. Raw freezing spectra were used to probe the freezing activity of both abundant and rare IN contained in sample liquids by analysis of drops that had varying degrees of preconcentration and size (~50 to ~650 μm). Extreme value statistics is used to collapse the raw freezing data into a single ice nuclei spectrum, defined as number of ice nuclei per volume of air as a function of temperature, that spans ~6 orders of magnitude in IN concentration. For a selected number of samples, concentrations of biological and non-biological ambient aerosol and particles are

  7. Glutathione-S-Transferase: A Minor Allergen in Birch Pollen due to Limited Release from Hydrated Pollen

    PubMed Central

    Vejvar, Eva; Kitzmüller, Claudia; Gadermaier, Gabriele; Nagl, Birgit; Vrtala, Susanne; Briza, Peter; Zlabinger, Gerhard J.; Jahn-Schmid, Beatrice; Ferreira, Fatima; Bohle, Barbara

    2014-01-01

    Background Recently, a protein homologous to glutathione-S-transferases (GST) was detected in prominent amounts in birch pollen by proteomic profiling. As members of the GST family are relevant allergens in mites, cockroach and fungi we investigated the allergenic relevance of GST from birch (bGST). Methodology bGST was expressed in Escherichia coli, purified and characterized by mass spectrometry. Sera from 217 birch pollen-allergic patients were tested for IgE-reactivity to bGST by ELISA. The mediator-releasing activity of bGST was analysed with IgE-loaded rat basophil leukaemia cells (RBL) expressing human FcεRI. BALB/c mice were immunized with bGST or Bet v 1. Antibody and T cell responses to either protein were assessed. IgE-cross-reactivity between bGST with GST from house dust mite, Der p 8, was studied with murine and human sera in ELISA. The release kinetics of bGST and Bet v 1 from birch pollen were assessed in water, simulated lung fluid, 0.9% NaCl and PBS. Eluted proteins were quantified by ELISA and analysed by immunoblotting. Principle findings Only 13% of 217 birch pollen-allergic patients showed IgE-reactivity to bGST. In RBL assays bGST induced mediator release. Immunization of mice with bGST induced specific IgE and a Th2-dominated cellular immune response comparably to immunization with Bet v 1. bGST did not cross-react with Der p 8. In contrast to Bet v 1, only low amounts of bGST were released from pollen grains upon incubation in water and the different physiological solutions. Conclusion/Significance Although bGST is abundant in birch pollen, immunogenic in mice and able to induce mediator release from effector cells passively loaded with specific IgE, it is a minor allergen for birch pollen-allergic patients. We refer this discrepancy to its limited release from hydrated pollen. Hence, bGST is an example demonstrating that allergenicity depends mainly on rapid elution from airborne particles. PMID:25275548

  8. CHARACTERIZATION OF THE MAIZE POLLEN TRANSCRIPTOME

    EPA Science Inventory

    Pollen is a primary vehicle for transgene flow from engineered plants to their non-transgenic, native or weedy relatives. Hence, gene flow will be affected by pollen fitness (e.g., how well a particular pollen grain can outcompete other pollen present on the stigma and complete ...

  9. A New Secondary Pollen Presentation Mechanism from a Wild Ginger (Zingiber densissimum) and Its Functional Roles in Pollination Process

    PubMed Central

    Fan, Yong-Li; Kress, W. John; Li, Qing-Jun

    2015-01-01

    Background and Aims Secondary pollen presentation (SPP), a floral mechanism of reproductive adaptation, has been described for more than 200 years, with nine types SPP recorded. However, few studies have been done experimentally to link the floral mechanism of SPP to its functional roles in pollination process. This study aims to describe a new SPP mechanism from a wild ginger (Zingiber densissimum, Zingiberaceae) and explore how the pollen arrangement of SPP affects pollen removal during the interaction with different pollinators. Methodology/Principal Findings Field observations and experiments revealed that flowers lasted for less than one day. The breeding system was partially self-incompatible. Two bee species, Macropis hedini (which carried pollen dorsally) and Amegilla zonata (which carried pollen ventrally) were the primary pollinators. About a third of pollen grains were relocated from the anther to the labellum staminode of flowers through the adherence of aggregated pollen chains, while other grains were presented on the anther. In a single visit, each bee species removed pollen grains from both the labellum staminode and the anther. Macropis hedini was more effective than Amegilla zonata. Conclusions/Significance Our study describes a new SPP mechanism in angiosperms. The new SPP mode enables pollen grains presented on the anther and the labellum staminode simultaneously via the adherence of aggregated pollen chains, thus promoting pollen to be taken away by different pollinators. This SPP mechanism plays a key role during pollen removal and may have evolved under the pressure to improve male fitness. PMID:26637125

  10. Grass pollen allergens globally: the contribution of subtropical grasses to burden of allergic respiratory diseases.

    PubMed

    Davies, J M

    2014-06-01

    types of subtropical grass pollens to achieve optimal diagnosis and treatment of patients with allergic respiratory disease in subtropical regions of the world. PMID:24684550

  11. City scale pollen concentration variability

    NASA Astrophysics Data System (ADS)

    van der Molen, Michiel; van Vliet, Arnold; Krol, Maarten

    2016-04-01

    Pollen are emitted in the atmosphere both in the country-side and in cities. Yet the majority of the population is exposed to pollen in cities. Allergic reactions may be induced by short-term exposure to pollen. This raises the question how variable pollen concentration in cities are in temporally and spatially, and how much of the pollen in cities are actually produced in the urban region itself. We built a high resolution (1 × 1 km) pollen dispersion model based on WRF-Chem to study a city's pollen budget and the spatial and temporal variability in concentration. It shows that the concentrations are highly variable, as a result of source distribution, wind direction and boundary layer mixing, as well as the release rate as a function of temperature, turbulence intensity and humidity. Hay Fever Forecasts based on such high resolution emission and physical dispersion modelling surpass traditional hay fever warning methods based on temperature sum methods. The model gives new insights in concentration variability, personal and community level exposure and prevention. The model will be developped into a new forecast tool to serve allergic people to minimize their exposure and reduce nuisance, coast of medication and sick leave. This is an innovative approach in hay fever warning systems.

  12. The role of glycosylation in flavonol-induced pollen germination.

    PubMed

    Taylor, L P; Strenge, D; Miller, K D

    1998-01-01

    Flavonols are small (C15) plant-specific molecules that are required for petunia and maize pollen to germinate. They exist in two chemical forms: the aglycone or glycosyl conjugates. Flavonol-deficient pollen is biochemically complemented by flavonol aglycones but not by the glycosylated forms that accumulate in wild type (WT) pollen. Coincident with the biochemical induction of germination, the added flavonol aglycone is rapidly converted to a galactoside and then to a glucosyl galactoside (diglycoside) that is identical to the compound present in WT pollen. A flavonol 3-O-galactosyltransferase (F3GalTase) activity has been identified that controls the formation of glycosylated flavonols in pollen. Importantly, this enzyme also catalyzes the reverse reaction, i.e. the production of the flavonol aglycone from the galactoside and UDP (Fig. 1). F3GalTase/RevGalTase therefore has the potential to control the level of the bioactive flavonol species and as a result, pollen germination. PMID:9781293

  13. Influence of wind direction on pollen concentration in the atmosphere

    NASA Astrophysics Data System (ADS)

    Silva Palacios, I.; Tormo Molina, R.; Muñoz Rodríguez, A. F.

    The daily pollen concentration in the atmosphere of Badajoz (SW Spain) was analysed over a 6-year period (1993-1998) using a volumetric aerobiological trap. The results for the main pollination period are compared with the number of hours of wind each day in the four quadrants: 1 (NE), 2 (SE), 3 (SW) and 4 (NW). The pollen source distribution allowed 16 pollen types to be analysed as a function of their distribution in the four quadrants with respect to the location of the trap. Four of them correspond to species growing in an irrigated farmland environment (Amaranthaceae-Chenopodiaceae, Plantago, Scirpus, and Typha), five to riparian and woodland species (Salix, Fraxinus, Alnus, Populus, and Eucalyptus), four to urban ornamentals (Ulmus, Arecaceae, Cupressaceae, and Casuarina), and three which include the most frequent pollen grains of widely distributed species (Poaceae, Quercus, and Olea). The results show that the distribution of the sources and the wind direction play a very major role in determining the pollen concentration in the atmosphere when these sources are located in certain quadrants, and that the widely distributed pollen sources show no relationship with wind direction. In some years the values of the correlations were not maintained, which leads one to presume that, in order to draw significant conclusions and establish clear patterns of the influence of wind direction, a continuous and more prolonged study will be required.

  14. Individual lifetime pollen and nectar foraging preferences in bumble bees

    NASA Astrophysics Data System (ADS)

    Hagbery, Jessica; Nieh, James C.

    2012-10-01

    Foraging specialization plays an important role in the ability of social insects to efficiently allocate labor. However, relatively little is known about the degree to which individual bumble bees specialize on collecting nectar or pollen, when such preferences manifest, and if individuals can alter their foraging preferences in response to changes in the colony workforce. Using Bombus impatiens, we monitored all foraging visits made by every bee in multiple colonies and showed that individual foragers exhibit consistent lifetime foraging preferences. Based upon the distribution of foraging preferences, we defined three forager types (pollen specialists, nectar specialists, and generalists). In unmanipulated colonies, 16-36 % of individuals specialized (≥90 % of visits) on nectar or pollen only. On its first day of foraging, an individual's foraging choices (nectar only, pollen only, or nectar and pollen) significantly predicted its lifetime foraging preferences. Foragers that only collected pollen on their first day of foraging made 1.61- to 1.67-fold more lifetime pollen foraging visits (as a proportion of total trips) than foragers that only collected nectar on their first foraging day. Foragers were significantly larger than bees that stayed only in the nest. We also determined the effect of removing pollen specialists at early (brood present) or later (brood absent) stages in colony life. These results suggest that generalists can alter their foraging preferences in response to the loss of a small subset of foragers. Thus, bumble bees exhibit individual lifetime foraging preferences that are established early in life, but generalists may be able to adapt to colony needs.

  15. Projected Carbon Dioxide to Increase Grass Pollen and Allergen Exposure Despite Higher Ozone Levels

    PubMed Central

    Albertine, Jennifer M.; Manning, William J.; DaCosta, Michelle; Stinson, Kristina A.; Muilenberg, Michael L.; Rogers, Christine A.

    2014-01-01

    One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10–30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change. PMID:25372614

  16. Grass Pollen Allergens

    PubMed Central

    Augustin, Rosa; Hayward, Barbara J.

    1962-01-01

    Cocksfoot and Timothy pollen extracts are each found to contain at least fifteen components antigenic in rabbits. Most of these can also be allergens for man, but only a few are regularly so. These `principal' allergens have now been isolated in highly purified form. Procedures are given for a simple method of preparing extracts for clinical purposes and for the partial separation, concentration and purification of the allergens by means of differential extractions of the pollens and by means of ultrafiltration, isoelectric precipitation and salt fractionations (at acid and neutral pH) of the extracts. Isoelectric precipitations gave highly pigmented acid complexes, two of which moved as single sharp peaks at pH 7.4 in free electrophoresis, but proved to be hardly active by skin tests. Acid NaCl fractionation of the remainder resulted for Cocksfoot and Timothy in the isolation of a nearly white powder (T21.111121112 = T21B) which was weight for weight 1000–10,000 times as active as the pollen from which it had been derived. The powders have retained their activity for 7 years. By gel diffusion tests, they were found to contain two antigens (one in each preparation) which were immunologically partially related, but the Timothy preparation contained in addition the `innermost' `twin' antigens specific for Timothy that we had discovered previously in the crude extracts by gel diffusion methods. Skin reactions could be elicited in hay-fever subjects by prick tests with concentrations of 10-9–10-8 g./ml., which is equivalent to intradermal injections of 10-11–10-10 mg. and represents a 300-fold purification with respect to the concentrates of crude pollen extracts prepared by ultrafiltration and dialysis. Fractionation on DEAE-cellulose of one of the highly purified Timothy preparations (T21.11112112 = T21A) and other, crude Timothy and Cocksfoot extracts resulted in considerable and reproducible separation of the various antigens, with no indication of the

  17. Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe

    NASA Astrophysics Data System (ADS)

    Liu, Li; Solmon, Fabien; Vautard, Robert; Hamaoui-Laguel, Lynda; Zsolt Torma, Csaba; Giorgi, Filippo

    2016-05-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hay fever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In this online approach pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000-2010. To reduce the large uncertainties notably due to the lack of information on ragweed density distribution, a calibration based on airborne pollen observations is used. Accordingly a cross validation is conducted and shows reasonable error and sensitivity of the calibration. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger and the model is better constrained. From these simulations health risks associated to common ragweed pollen

  18. Cellular dynamics during early barley pollen embryogenesis revealed by time-lapse imaging

    PubMed Central

    Daghma, Diaa Eldin S.; Hensel, Goetz; Rutten, Twan; Melzer, Michael; Kumlehn, Jochen

    2014-01-01

    Plants display a remarkable capacity for cellular totipotency. An intriguing and useful example is that immature pollen cultured in vitro can pass through embryogenic development to form haploid or doubled haploid plants. However, a lack of understanding the initial mechanisms of pollen embryogenesis hampers the improvement and more effective and widespread employment of haploid technology in plant research and breeding. To investigate the cellular dynamics during the onset of pollen embryogenesis, we used time-lapse imaging along with transgenic barley expressing nuclear localized Green Fluorescent Protein. The results enabled us to identify nine distinct embryogenic and non-embryogenic types of pollen response to the culture conditions. Cell proliferation in embryogenic pollen normally started via a first symmetric mitosis (54.3% of pollen observed) and only rarely did so via asymmetric pollen mitosis I (4.3% of pollen observed). In the latter case, proliferation generally originated from the vegetative-like cell, albeit the division of the generative-like cell was observed in few types of pollen. Under the culture conditions used, fusion of cell nuclei was the only mechanism of genome duplication observed. PMID:25538715

  19. Pollen specificity elements reside in 30 bp of the proximal promoters of two pollen-expressed genes.

    PubMed

    Eyal, Y; Curie, C; McCormick, S

    1995-03-01

    Functional analyses previously identified minimal promoter regions required for maintaining high-level expression of the late anther tomato LAT52 and LAT59 genes in tomato pollen. Here, we now define elements that direct pollen specificity. We used a transient assay system consisting of two cell types that differentially express the LAT genes and both "loss-of-function" and "gain-of-function" approaches. Linker substitution mutants analyzed in the transient assay and in transgenic plants identified 30-bp proximal promoter regions of LAT52 and LAT59 that are essential for their expression in pollen and that confer pollen specificity when fused to the heterologous cauliflower mosaic virus 35S core promoter. In vivo competition experiments demonstrated that a common trans-acting factor interacts with the pollen specificity region of both LAT gene promoters and suggested that a common mechanism regulates their coordinate expression. Adjacent upstream elements, the 52/56 box in LAT52 and the 56/59 box in LAT59, are involved in modulating the level of expression in pollen. The 52/56 box may be a target for the binding of a member of the GT-1 transcription factor family. PMID:7734969

  20. Pollen specificity elements reside in 30 bp of the proximal promoters of two pollen-expressed genes.

    PubMed Central

    Eyal, Y; Curie, C; McCormick, S

    1995-01-01

    Functional analyses previously identified minimal promoter regions required for maintaining high-level expression of the late anther tomato LAT52 and LAT59 genes in tomato pollen. Here, we now define elements that direct pollen specificity. We used a transient assay system consisting of two cell types that differentially express the LAT genes and both "loss-of-function" and "gain-of-function" approaches. Linker substitution mutants analyzed in the transient assay and in transgenic plants identified 30-bp proximal promoter regions of LAT52 and LAT59 that are essential for their expression in pollen and that confer pollen specificity when fused to the heterologous cauliflower mosaic virus 35S core promoter. In vivo competition experiments demonstrated that a common trans-acting factor interacts with the pollen specificity region of both LAT gene promoters and suggested that a common mechanism regulates their coordinate expression. Adjacent upstream elements, the 52/56 box in LAT52 and the 56/59 box in LAT59, are involved in modulating the level of expression in pollen. The 52/56 box may be a target for the binding of a member of the GT-1 transcription factor family. PMID:7734969

  1. [Air-borne disease].

    PubMed

    Lameiro Vilariño, Carmen; del Campo Pérez, Victor M; Alonso Bürger, Susana; Felpeto Nodar, Irene; Guimarey Pérez, Rosa; Pérez Alvarellos, Alberto

    2003-11-01

    Respiratory protection is a factor which worries nursing professionals who take care of patients susceptible of transmitting microorganisms through the air more as every day passes. This type of protection covers the use of surgical or hygienic masks against the transmission of infection by airborne drops to the use of highly effective masks or respirators against the transmission of airborne diseases such as tuberculosis or SARS, a recently discovered disease. The adequate choice of this protective device and its correct use are fundamental in order to have an effective protection for exposed personnel. The authors summarize the main protective respiratory devices used by health workers, their characteristics and degree of effectiveness, as well as the circumstances under which each device is indicated for use. PMID:14705591

  2. The patterns of Corylus and Alnus pollen seasons and pollination periods in two Polish cities located in different climatic regions.

    PubMed

    Puc, Małgorzata; Kasprzyk, Idalia

    2013-01-01

    This study compares phenological observations of Corylus (hazel) and Alnus (alder) flowering with airborne pollen counts of these taxa recorded using volumetric spore traps (2009-2011). The work was carried out in the Polish cities of Szczecin and Rzeszów that are located in different climatic regions. Correlations between pollen concentrations and meteorological data were investigated using Spearman's rank correlation analysis. The timings of hazel and alder pollination and the occurrence of airborne pollen varied greatly and were significantly influenced by meteorological conditions (p < 0.05). The flowering synchronization of hazel and alder pollination in Szczecin and Rzeszów varied over the study period. Hazel and alder trees flowered notably earlier in stands located in places that were exposed to sunlight (insolated) and sheltered from the wind. On the other hand, a delay in the timing of pollination was observed in quite sunny but very windy sites. In Rzeszów, maximum hazel pollen concentrations did not coincide with the period of full pollination (defined as between 25 % hazel and alder and 75 % of flowers open). Conversely, in Szczecin, the highest hazel pollen concentrations were recorded during phenophases of the full pollination period. The period when the highest alder pollen concentrations were recorded varied between sites, with Rzeszów recording the highest concentrations at the beginning of pollination and Szczecin recording alder pollen throughout the full pollination period. Substantial amounts of hazel and alder pollen grains were recorded in the air of Rzeszów (but not Szczecin) before the onset of the respective pollen seasons. PMID:24098067

  3. The Arabidopsis KINβγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen

    PubMed Central

    Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-01-01

    Pollen–stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen–stigma interactions is poorly understood. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINβγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinβγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinβγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinβγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinβγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINβγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen–stigma interactions during pollination. PMID:27472382

  4. Variations in Quercus sp. pollen seasons (1996-2011) in Poznań, Poland, in relation to meteorological parameters.

    PubMed

    Grewling, Lukasz; Jackowiak, Bogdan; Smith, Matt

    2014-01-01

    The aim of this study is to supply detailed information about oak (Quercus sp.) pollen seasons in Poznań, Poland, based on a 16-year aerobiological data series (1996-2011). The pollen data were collected using a volumetric spore trap of the Hirst design located in Poznań city center. The limits of the pollen seasons were calculated using the 95 % method. The influence of meteorological parameters on temporal variations in airborne pollen was examined using correlation analysis. Start and end dates of oak pollen seasons in Poznań varied markedly from year-to-year (14 and 17 days, respectively). Most of the pollen grains (around 75 % of the seasonal pollen index) were recorded within the first 2 weeks of the pollen season. The tenfold variation was observed between the least and the most intensive pollen seasons. These fluctuations were significantly related to the variation in the sum of rain during the period second fortnight of March to first fortnight of April the year before pollination (r = 0.799; p < 0.001). During the analyzing period, a significant advance in oak pollen season start dates was observed (-0.55 day/year; p = 0.021), which was linked with an increase in the mean temperature during the second half of March and first half of April (+0.2 °C; p = 0.014). Daily average oak pollen counts correlated positively with mean and maximum daily temperatures, and negatively with daily rainfall and daily mean relative humidity. PMID:24817783

  5. World Allergy Organization Study on Aerobiology for Creating First Pollen and Mold Calendar With Clinical Significance in Islamabad, Pakistan; A Project of World Allergy Organization and Pakistan Allergy, Asthma & Clinical Immunology Centre of Islamabad

    PubMed Central

    2012-01-01

    Pollen and mold allergies are highly problematic in Islamabad. This study was conducted to investigate the type and concentration of airborne pollens/molds causing allergic diseases in susceptible individuals. A volumetric spore trap (Burkard) was placed at the height of 11 m and ran continuously for 3 years. Once a week, the collecting drum was prepared by affixing Melinex tape with a double sided adhesive that was coated with a thin layer of silicone grease. Every Sunday at 9:00 AM the drum was replaced by another drum and the pollen/mold spores were removed and permanently mounted on slides. Using a microscope, the trapped particles were identified and recorded as counts per cubic meter of air per hour. From these data, the pollen and mold calendars were constructed and expressed as counts per cubic meter of air per day. Skin prick tests were performed on more than 1000 patients attending the Pakistan Allergy, Asthma & Clinical Immunology Centre of Islamabad. The results indicated that there were 2 main pollen plants that contributed to seasonal allergies. These were Broussonetia papyrifera and Cannabis sativa during the March/April season and the July/September season, respectively. Although mold spores were continuously detected throughout the year, the most prominent mold was undetected mold and unconfirmed mold species similar to Stachybotrys species, which was high from July to September/October. Two additional molds contributing to allergic reactions were Pithomyces species and Cladosporium species, which were active during January and April, with the latter also being detected between October and November. These results may prove beneficial to both patients and physicians in planning a therapeutic protocol for avoidance and amelioration. PMID:23283209

  6. Determination of sound types and source levels of airborne vocalizations by California sea lions, Zalophus californianus, in rehabilitation at the Marine Mammal Center in Sausalito, California

    NASA Astrophysics Data System (ADS)

    Schwalm, Afton Leigh

    California sea lions (Zalophus californianus) are a highly popular and easily recognized marine mammal in zoos, aquariums, circuses, and often seen by ocean visitors. They are highly vocal and gregarious on land. Surprisingly, little research has been performed on the vocalization types, source levels, acoustic properties, and functions of airborne sounds used by California sea lions. This research on airborne vocalizations of California sea lions will advance the understanding of this aspect of California sea lions communication, as well as examine the relationship between health condition and acoustic behavior. Using a PhillipsRTM digital recorder with attached microphone and a calibrated RadioShackRTM sound pressure level meter, acoustical data were recorded opportunistically on California sea lions during rehabilitation at The Marine Mammal Center in Sausalito, CA. Vocalizations were analyzed using frequency, time, and amplitude variables with Raven Pro: Interactive Sound Analysis Software Version 1.4 (The Cornell Lab of Ornithology, Ithaca, NY). Five frequency, three time, and four amplitude variables were analyzed for each vocalization. Differences in frequency, time, and amplitude variables were not significant by sex. The older California sea lion group produced vocalizations that were significantly lower in four frequency variables, significantly longer in two time variables, significantly higher in calibrated maximum and minimum amplitude variables, and significantly lower in frequency at maximum and minimum amplitude compared with pups. Six call types were identified: bark, goat, growl/grumble, bark/grumble, bark/growl, and grumble/moan. The growl/grumble call was higher in dominant beginning, ending, and minimum frequency, as well as in the frequency at maximum amplitude compared with the bark, goat, bark/grumble calls in the first versus last vocalization sample. The goat call was significantly higher in first harmonic interval than any other call type

  7. A new method for determining the sources of airborne particles.

    PubMed

    Oteros, J; García-Mozo, H; Alcázar, P; Belmonte, J; Bermejo, D; Boi, M; Cariñanos, P; Díaz de la Guardia, C; Fernández-González, D; González-Minero, F; Gutiérrez-Bustillo, A M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, F J; Ruíz-Valenzuela, L; Suárez-Pérez, J; Trigo, M M; Domínguez-Vilches, E; Galán, C

    2015-05-15

    Air quality is a major issue for humans owing to the fact that the content of particles in the atmosphere has multiple implications for life quality, ecosystem dynamics and environment. Scientists are therefore particularly interested in discovering the origin of airborne particles. A new method has been developed to model the relationship between the emission surface and the total amount of airborne particles at a given distance, employing olive pollen and olive groves as examples. A third-degree polynomial relationship between the air particles at a particular point and the distance from the source was observed, signifying that the nearest area to a point is not that which is most correlated with its air features. This work allows the origin of airborne particles to be discovered and could be implemented in different disciplines related to atmospheric aerosol, thus providing a new approach with which to discover the dynamics of airborne particles. PMID:25837296

  8. Modern pollen data from North America and Greenland for multi-scale paleoenvironmental applications

    USGS Publications Warehouse

    Whitmore, J.; Gajewski, K.; Sawada, M.; Williams, J.W.; Shuman, B.; Bartlein, P.J.; Minckley, T.; Viau, A.E.; Webb, T., III; Shafer, S.; Anderson, P.; Brubaker, L.

    2005-01-01

    The modern pollen network in North America and Greenland is presented as a database for use in quantitative calibration studies and paleoenvironmental reconstructions. The georeferenced database includes 4634 samples from all regions of the continent and 134 pollen taxa that range from ubiquitous to regionally diagnostic taxa. Climate data and vegetation characteristics were assigned to every site. Automated and manual procedures were used to verify the accuracy of geographic coordinates and identify duplicate records among datasets, incomplete pollen sums, and other potential errors. Data are currently available for almost all of North America, with variable density. Pollen taxonomic diversity, as measured by the Shannon-Weiner coefficient, varies as a function of location, as some vegetation regions are dominated by one or two major pollen producers, while other regions have a more even composition of pollen taxa. Squared-chord distances computed between samples show that most modern pollen samples find analogues within their own vegetation zone. Both temperature and precipitation inferred from best analogues are highly correlated with observed values but temperature exhibits the strongest relation. Maps of the contemporary distribution of several pollen types in relation to the range of the plant taxon illustrate the correspondence between plant and pollen ranges. ?? 2005 Elsevier Ltd. All rights reserved.

  9. Pollen Tubes Lacking a Pair of K+ Transporters Fail to Target Ovules in Arabidopsis[C][W][OA

    PubMed Central

    Lu, Yongxian; Chanroj, Salil; Zulkifli, Lalu; Johnson, Mark A.; Uozumi, Nobuyuki; Cheung, Alice; Sze, Heven

    2011-01-01

    Flowering plant reproduction requires precise delivery of the sperm cells to the ovule by a pollen tube. Guidance signals from female cells are being identified; however, how pollen responds to those cues is largely unknown. Here, we show that two predicted cation/proton exchangers (CHX) in Arabidopsis thaliana, CHX21 and CHX23, are essential for pollen tube guidance. Male fertility was unchanged in single chx21 or chx23 mutants. However, fertility was impaired in chx21 chx23 double mutant pollen. Wild-type pistils pollinated with a limited number of single and double mutant pollen producing 62% fewer seeds than those pollinated with chx23 single mutant pollen, indicating that chx21 chx23 pollen is severely compromised. Double mutant pollen grains germinated and grew tubes down the transmitting tract, but the tubes failed to turn toward ovules. Furthermore, chx21 chx23 pollen tubes failed to enter the micropyle of excised ovules. Green fluorescent protein–tagged CHX23 driven by its native promoter was localized to the endoplasmic reticulum of pollen tubes. CHX23 mediated K+ transport, as CHX23 expression in Escherichia coli increased K+ uptake and growth in a pH-dependent manner. We propose that by modifying localized cation balance and pH, these transporters could affect steps in signal reception and/or transduction that are critical to shifting the axis of polarity and directing pollen growth toward the ovule. PMID:21239645

  10. Pollen mixing in pollen generalist solitary bees: a possible strategy to complement or mitigate unfavourable pollen properties?

    PubMed

    Eckhardt, Michael; Haider, Mare; Dorn, Silvia; Müller, Andreas

    2014-05-01

    Generalist herbivorous insects, which feed on plant tissue that is nutritionally heterogeneous or varies in its content of secondary metabolites, often benefit from dietary mixing through more balanced nutrient intake or reduced exposure to harmful secondary metabolites. Pollen is similarly heterogeneous as other plant tissue in its content of primary and secondary metabolites, suggesting that providing their offspring with mixed pollen diets might be a promising strategy for pollen generalist bees to complement nutrient imbalances or to mitigate harmful secondary metabolites of unfavourable pollen. In the present study, we compared larval performance of the pollen generalist solitary bee species Osmia cornuta (Megachilidae) on five experimental pollen diets that consisted of different proportions of unfavourable pollen diet of Ranunculus acris (Ranunculaceae) and favourable pollen diet of Sinapis arvensis (Brassicaceae). In addition, we microscopically analysed the pollen contained in the scopal brushes of field-collected females of O. cornuta and three closely related species to elucidate to what degree these pollen generalist bees mix pollen of different hosts in their brood cells. In striking contrast to a pure Ranunculus pollen diet, which had a lethal effect on most developing larvae of O. cornuta, larval survival, larval development time and adult body mass of both males and females remained nearly unaffected by the admixture of up to 50% of Ranunculus pollen diet to the larval food. Between 42% and 66% of all female scopal pollen loads analysed contained mixtures of pollen from two to six plant families, indicating that pollen mixing is a common behaviour in O. cornuta and the three related bee species. The present study provides the first evidence that the larvae of pollen generalist bees can benefit from the nutrient content of unfavourable pollen without being negatively affected by its unfavourable chemical properties if such pollen is mixed with

  11. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    PubMed Central

    Vogler, Frank; Konrad, Sebastian S. A.; Sprunck, Stefanie

    2015-01-01

    Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane. PMID:25954283

  12. Statistical approach to the analysis of olive long-term pollen season trends in southern Spain.

    PubMed

    García-Mozo, H; Yaezel, L; Oteros, J; Galán, C

    2014-03-01

    Analysis of long-term airborne pollen counts makes it possible not only to chart pollen-season trends but also to track changing patterns in flowering phenology. Changes in higher plant response over a long interval are considered among the most valuable bioindicators of climate change impact. Phenological-trend models can also provide information regarding crop production and pollen-allergen emission. The interest of this information makes essential the election of the statistical analysis for time series study. We analysed trends and variations in the olive flowering season over a 30-year period (1982-2011) in southern Europe (Córdoba, Spain), focussing on: annual Pollen Index (PI); Pollen Season Start (PSS), Peak Date (PD), Pollen Season End (PSE) and Pollen Season Duration (PSD). Apart from the traditional Linear Regression analysis, a Seasonal-Trend Decomposition procedure based on Loess (STL) and an ARIMA model were performed. Linear regression results indicated a trend toward delayed PSE and earlier PSS and PD, probably influenced by the rise in temperature. These changes are provoking longer flowering periods in the study area. The use of the STL technique provided a clearer picture of phenological behaviour. Data decomposition on pollination dynamics enabled the trend toward an alternate bearing cycle to be distinguished from the influence of other stochastic fluctuations. Results pointed to show a rising trend in pollen production. With a view toward forecasting future phenological trends, ARIMA models were constructed to predict PSD, PSS and PI until 2016. Projections displayed a better goodness of fit than those derived from linear regression. Findings suggest that olive reproductive cycle is changing considerably over the last 30years due to climate change. Further conclusions are that STL improves the effectiveness of traditional linear regression in trend analysis, and ARIMA models can provide reliable trend projections for future years taking into

  13. Comparative Structure and Pollen Production of the Stamens and Pollinator-deceptive Staminodes of Commelina coelestis and C. dianthifolia (Commelinaceae)

    PubMed Central

    HRYCAN, WILLIAM C.; DAVIS, ARTHUR R.

    2005-01-01

    • Background and Aims Flowers of Commelina coelestis and C. dianthifolia provide pollen alone as a floral reward, and rely on visual cues to attract pollinators. Three stamen types, all producing pollen, occur in each of these species: two cryptically coloured lateral stamens, a single cryptically coloured central stamen and three bright yellow staminodes that sharply contrast with the blue to purple corolla. The objective was to compare the stamen structure and pollen characteristics of each of the three stamen types, and to test the hypothesis that the staminodes are poor contributors of viable pollen for the siring of seed. The pollination roles of the three stamen types and the breeding systems of both species were also explored. • Methods Light, fluorescence and scanning electron microscopy were utilized to examine stamen morphology and pollen structure and viability. Controlled hand pollinations were used to explore the breeding system of each species. Filament and style lengths were measured to investigate herkogamy and autogamy. • Key Results Pollen from all stamen morphs is viable, but staminode pollen has significantly lower viability. Pollen polymorphism exists both (a) between the lateral and central stamens and the staminodes, and (b) within each anther. Lateral and central stamens have thicker endothecia with a greater number of secondary cell wall thickenings than the staminodes. • Conclusions Both species are entomophilous and facultatively autogamous. Lateral stamen pollen is important for cross-pollination, central stamen pollen is utilized by both species as a pollinator reward and for delayed autogamy in C. dianthifolia, and the staminodes mimic, by means of both colour and epidermal features, large amounts of pollen to attract insects to the flowers. Pollen from all three anther morphs is capable of siring seed, although staminode pollen is inferior. The thin staminode endothecium with fewer secondary thickenings retards staminode

  14. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    SciTech Connect

    Mohd-Arrabe', A. B.; Noraini, Talip Noraini

    2013-11-27

    Rhizophora L. are common mangrove genus in Peninsular Malaysia, it contains 3 species and 1 hybrid (R. apiculata Blume, R. mucronata Lam., R. stylosa Griff., R. x lamarckii Montrouz). This genus has some unique adaptation towards extreme environment. Rhizophora has looping aerial stilt-root and uniformly viviparous. The aim of this study is to investigate the variation in the pollen morphology of Rhizophora that can be related to their habitat. Methods include in this study is pollen observation under light and acetolysis method under scanning electron microscope. Pollen type of Rhizophora species studied except hybrid species is classified tricolporate, shape spheroidal based on ratio of length polar axis/ length of equatorial axis (1.03 - 1.09). The exine ornamentation is perforate-reticulate for R. apiculata and R. mucronata, while R. stylosa is perforate. For the only hybrid in Peninsular Malaysia, R. x lamarckii (R. apiculata x R. stylosa) differs from others, tricolpate with the absence of porate, shape is subprolate and exine ornamentation is reticulate and striate in equatorial region. Pollenkitt is present due to the salty and extreme environment. This may enhance the volume of pollenkitt present surrounding the pollen grains in Rhizophora for protection and adaptation purposes. Based on these findings, it is evident that pollen morphology is somehow related to its natural habitat.

  15. Hydrogen peroxide affects ion channels in lily pollen grain protoplasts.

    PubMed

    Breygina, M A; Abramochkin, D V; Maksimov, N M; Yermakov, I P

    2016-09-01

    Ion homeostasis plays a central role in polarisation and polar growth. In several cell types ion channels are controlled by reactive oxygen species (ROS). One of the most important cells in the plant life cycle is the male gametophyte, which grows under the tight control of both ion fluxes and ROS balance. The precise relationship between these two factors in pollen tubes has not been completely elucidated, and in pollen grains it has never been studied to date. In the present study we used a simple model - protoplasts obtained from lily pollen grains at the early germination stage - to reveal the effect of H2 O2 on cation fluxes crucial for pollen germination. Here we present direct evidence for two ROS-sensitive currents on the pollen grain plasma membrane: the hyperpolarisation-activated calcium current, which is strongly enhanced by H2 O2 , and the outward potassium current, which is modestly enhanced by H2 O2 . We used low concentrations of H2 O2 that do not cause an intracellular oxidative burst and do not damage cells, as demonstrated with fluorescent staining. PMID:27115728

  16. Airborne Spectral BRDF of Various Surface Types (Ocean, Vegetation, Snow, Desert, Wetlands, Cloud Decks, Smoke Layers) for Remote Sensing Applications

    NASA Technical Reports Server (NTRS)

    Gatebe, Charles K.; King, Michael D.

    2016-01-01

    In this paper we describe measurements of the bidirectional reflectance-distribution function (BRDF) acquired over a 30-year period (1984-2014) by the National Aeronautics and Space Administration's (NASA's) Cloud Absorption Radiometer (CAR). Our BRDF database encompasses various natural surfaces that are representative of many land cover or ecosystem types found throughout the world. CAR's unique measurement geometry allows a comparison of measurements acquired from different satellite instruments with various geometrical configurations, none of which are capable of obtaining such a complete and nearly instantaneous BRDF. This database is therefore of great value in validating many satellite sensors and assessing corrections of reflectances for angular effects. These data can also be used to evaluate the ability of analytical models to reproduce the observed directional signatures, to develop BRDF models that are suitable for sub-kilometer-scale satellite observations over both homogeneous and heterogeneous landscape types, and to test future spaceborne sensors. All of these BRDF data are publicly available and accessible in hierarchical data format (http:car.gsfc.nasa.gov/).

  17. Bioassaying for ozone with pollen systems

    SciTech Connect

    Feder, W.A.

    1981-01-01

    Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Year-round pollen producion can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilities without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality.

  18. A theoretical model for airborne radars

    NASA Astrophysics Data System (ADS)

    Faubert, D.

    1989-11-01

    This work describes a general theory for the simulation of airborne (or spaceborne) radars. It can simulate many types of systems including Airborne Intercept and Airborne Early Warning radars, airborne missile approach warning systems etc. It computes the average Signal-to-Noise ratio at the output of the signal processor. In this manner, one obtains the average performance of the radar without having to use Monte Carlo techniques. The model has provision for a waveform without frequency modulation and one with linear frequency modulation. The waveform may also have frequency hopping for Electronic Counter Measures or for clutter suppression. The model can accommodate any type of encounter including air-to-air, air-to-ground (look-down) and rear attacks. It can simulate systems with multiple phase centers on receive for studying advanced clutter or jamming interference suppression techniques. An Airborne Intercept radar is investigated to demonstrate the validity and the capability of the model.

  19. Poor correlation between the removal or deposition of pollen grains and frequency of pollinator contact with sex organs

    NASA Astrophysics Data System (ADS)

    Sakamoto, Ryota L.; Morinaga, Shin-Ichi

    2013-09-01

    Pollinators deposit pollen grains on stigmas and remove pollen grains from anthers. The mechanics of these transfers can now be quantified with the use of high-speed video. We videoed hawkmoths, carpenter bees, and swallowtail butterflies pollinating Clerodendrum trichotomum. The number of grains deposited on stigmas did not vary significantly with the number of times pollinators contacted stigmas. In contrast, pollen removal from the anthers increased significantly with the number of contacts to anthers. Pollen removal varied among the three types of pollinators. Also, the three types carried pollen on different parts of their bodies. In hawkmoths and carpenter bees, a large number of contacted body part with anthers differed significantly from the body part that attached a large number of pollen grains. Our results indicate that a large number of contacts by pollinators does not increase either the male or female reproductive success of plants compared to a small number of contacts during a visit.

  20. Poor correlation between the removal or deposition of pollen grains and frequency of pollinator contact with sex organs.

    PubMed

    Sakamoto, Ryota L; Morinaga, Shin-Ichi

    2013-09-01

    Pollinators deposit pollen grains on stigmas and remove pollen grains from anthers. The mechanics of these transfers can now be quantified with the use of high-speed video. We videoed hawkmoths, carpenter bees, and swallowtail butterflies pollinating Clerodendrum trichotomum. The number of grains deposited on stigmas did not vary significantly with the number of times pollinators contacted stigmas. In contrast, pollen removal from the anthers increased significantly with the number of contacts to anthers. Pollen removal varied among the three types of pollinators. Also, the three types carried pollen on different parts of their bodies. In hawkmoths and carpenter bees, a large number of contacted body part with anthers differed significantly from the body part that attached a large number of pollen grains. Our results indicate that a large number of contacts by pollinators does not increase either the male or female reproductive success of plants compared to a small number of contacts during a visit. PMID:23928839

  1. Variation of microsporogenesis in monocots producing monosulcate pollen grains

    PubMed Central

    Toghranegar, Z.; Nadot, S.; Albert, B.

    2013-01-01

    Background and Aims Microsporogenesis leading to monosulcate pollen grains has already been described for a wide range of monocot species. However, a detailed study of additional callose deposition after the completion of the cleavage walls has been neglected so far. The study of additional callose deposition in monosulcate pollen grain has gained importance since a correlation between additional callose deposition and aperture location has recently been revealed. Methods Microsporogenesis is described for 30 species belonging to eight families of the monocots: Acoraceae, Amaryllidaceae, Alstroemeriaceae, Asparagaceae, Butomaceae, Commelinaceae, Liliaceae and Xanthorrhoeaceae. Key Results Five different microsporogenesis pathways are associated with monosulcate pollen grain. They differ in the type of cytokinesis, tetrad shape, and the presence and shape of additional callose deposition. Four of them present additional callose deposition. Conclusions In all these different microsporogenesis pathways, aperture location seems to be linked to the last point of callose deposition. PMID:23666889

  2. [The epidemiology of pollen allergy].

    PubMed

    Charpin, D; Caillaud, D

    2014-04-01

    The prevalence of seasonal allergic rhinitis can be established through surveys performed in a sample of the general population. These surveys are based on a questionnaire, which could lead to an overestimate of prevalence rates, and on measurements of specific IgE, which need to be interpreted in the light of the responses to the questionnaire. Such surveys are few in France and need to be updated. Risk factors for seasonal allergic rhinitis are genetic, epigenetic and environmental. Relationships between exposure to pollen and health can be documented through ecological and panel surveys. Panel surveys may give information on threshold levels and dose-response relationships. In addition to pollen exposure, global warming and air pollutants act as cofactors. Monitoring of both pollen exposure and its health effects should be encouraged and strengthened. PMID:24750956

  3. Pollen Recovery from Insects: Light Microscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous insect species feed on the pollen, nectar, and other plant exudates that are associated with flowers. As a result of this feeding activity, pollen becomes attached to the insects. Analysis of the pollen attached to these insects can reveal what insects eat, their dispersal patterns in and...

  4. Pollen Analysis of Natural Honeys from the Central Region of Shanxi, North China

    PubMed Central

    Song, Xiao-Yan; Yao, Yi-Feng; Yang, Wu-De

    2012-01-01

    Based on qualitative and quantitative melissopalynological analyses, 19 Chinese honeys were classified by botanical origin to determine their floral sources. The honey samples were collected during 2010–2011 from the central region of Shanxi Province, North China. A diverse spectrum of 61 pollen types from 37 families was identified. Fourteen samples were classified as unifloral, whereas the remaining samples were multifloral. Bee-favoured families (occurring in more than 50% of the samples) included Caprifoliaceae (found in 10 samples), Laminaceae (10), Brassicaceae (12), Rosaceae (12), Moraceae (13), Rhamnaceae (15), Asteraceae (17), and Fabaceae (19). In the unifloral honeys, the predominant pollen types were Ziziphus jujuba (in 5 samples), Robinia pseudoacacia (3), Vitex negundo var. heterophylla (2), Sophora japonica (1), Ailanthus altissima (1), Asteraceae type (1), and Fabaceae type (1). The absolute pollen count (i.e., the number of pollen grains per 10 g honey sample) suggested that 13 samples belonged to Group I (<20,000 pollen grains), 4 to Group II (20,000–100,000), and 2 to Group III (100,000–500,000). The dominance of unifloral honeys without toxic pollen grains and the low value of the HDE/P ratio (i.e., honey dew elements/pollen grains from nectariferous plants) indicated that the honey samples are of good quality and suitable for human consumption. PMID:23185358

  5. Airborne laser topographic mapping results

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Collins, J. G.; Link, L. E.; Swift, R. N.; Butler, M. L.

    1984-01-01

    The results of terrain mapping experiments utilizing the National Aeronautics and Space Administration (NASA) Airborne Oceanographic Lidar (AOL) over forested areas are presented. The flight tests were conducted as part of a joint NASA/U.S. Army Corps of Engineers (CE) investigation aimed at evaluating the potential of an airborne laser ranging system to provide cross-sectional topographic data on flood plains that are difficult and expensive to survey using conventional techniques. The data described in this paper were obtained in the Wolf River Basin located near Memphis, TN. Results from surveys conducted under winter 'leaves off' and summer 'leaves on' conditions, aspects of day and night operation, and data obtained from decidous and coniferous tree types are compared. Data processing techniques are reviewed. Conclusions relative to accuracy and present limitations of the AOL, and airborne lidar systems in general, to terrain mapping over forested areas are discussed.

  6. Magnetic pollen grains as sorbents for facile removal of organic pollutants in aqueous media.

    PubMed

    Thio, Beng Joo Reginald; Clark, Kristin K; Keller, Arturo A

    2011-10-30

    Plant materials have long been demonstrated to sorb organic compounds. However, there are no known reports about pollen grains acting as sorbents to remove hydrophobic organic compounds (HOCs) such as pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) from contaminated waters. We report a facile and effective method to remove HOCs from water using magnetized short ragweed (Ambrosia artemisiifolia) pollen grains. We dispersed the magnetized pollen grains in two different water samples - deionized (DI) and natural storm water to mimic real environmental conditions likely to be encountered during treatment. The magnetized pollen grains were readily separated from the aqueous media via a magnetic field after adsorption of the HOCs. We measured the adsorption of five representative HOCs (acenaphthene, phenanthrene, atrazine, diuron, and lindane) onto magnetized ragweed pollen in different aqueous matrices. We demonstrate that the adsorption capacity of the magnetized ragweed pollen can be regenerated to a large extent for reuse as a sorbent. Our results also indicate that the magnetized pollen grains are as effective as activated carbon (AC) in removing HOCs from both types of contaminated waters. The high HOC sorption of the ragweed pollen allows it to have potential remediation application in the field under realistic conditions. PMID:21871731

  7. Characterization of ragweed pollen adhesion to polyamides and polystyrene using atomic force microscopy.

    PubMed

    Thio, Beng Joo Reginald; Lee, Jung-Hyun; Meredith, J Carson

    2009-06-15

    Pollen is a leading contributor to asthma and allergies, yet pollen adhesion to common indoor surfaces is not well understood. We report the adhesive behavior of short ragweed (A. artemisiifolia) pollen grains with Nylon 6 (N6) and Nylon 6,6 (N66), chosen due to their use in synthetic carpet, and three control surfaces: polyamide 12 (PA12), polystyrene (PS), and silicon. The forces were measured by using atomic force microscopy (AFM) under controlled humidity, where single pollen grains were attached to tipless AFM cantilevers. Pollen grains had an average adhesion of 10 +/- 3 nN with the surfaces, independent of surface type or relative humidity from 20% to 60%. van der Waals forces are the primary molecular attraction driving pollen adhesion to these surfaces. The results also indicate that ragweed pollen contacts the polymer surface via its exine surface spikes, and the total adhesion force scales with the number of contacts. The pollen surface spikes are strong, resisting fracture and compliance up to a load of 0.5 GPa. PMID:19603639

  8. Use of Remote Sensing and Dust Modelling to Evaluate Ecosystem Phenology and Pollen Dispersal

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey C.; Sprigg, William A.; Watts, Carol; Shaw, Patrick

    2007-01-01

    The impact of pollen release and downwind concentrations can be evaluated utilizing remote sensing. Previous NASA studies have addressed airborne dust prediction systems PHAiRS (Public Health Applications in Remote Sensing) which have determined that pollen forecasts and simulations are possible. By adapting the deterministic dust model (as an in-line system with the National Weather Service operational forecast model) used in PHAiRS to simulate downwind dispersal of pollen, initializing the model with pollen source regions from MODIS, assessing the results a rapid prototype concept can be produced. We will present the results of our effort to develop a deterministic model for predicting and simulating pollen emission and downwind concentration to study details or phenology and meteorology and their dependencies, and the promise of a credible real time forecast system to support public health and agricultural science and service. Previous studies have been done with PHAiRS research, the use of NASA data, the dust model and the PHAiRS potential to improve public health and environmental services long into the future.

  9. Review of probabilistic pollen-climate transfer methods

    NASA Astrophysics Data System (ADS)

    Ohlwein, Christian; Wahl, Eugene R.

    2012-01-01

    Pollen-climate transfer methods are reviewed from a Bayesian perspective and with a special focus on the formulation of uncertainties. This approach is motivated by recent developments of spatial multi-proxy Bayesian hierarchical models (BHM), which allow synthesizing local reconstructions from different proxies for a spatially complete picture of past climate. In order to enhance the pollen realism in these models we try to bridge the gap between spatial statistics and paleoclimatology and show how far classical pollen-climate transfer concepts such as regression methods, mutual climatic range, modern analogues, plant functional types, and biomes can be understood in novel ways by refining the data models used in BHMs. As a case study, we discuss modeling of uncertainty by introducing a new probabilistic pollen ratio model, which is a simplified variation of the modern analogue technique (MAT) including the concept of response surfaces and designed for later inclusion in a spatial multiproxy BHM. Applications to fossil pollen data from varved sediments in three nearby lakes in west-central Wisconsin, USA and for a Holocene fossil pollen record from southern California, USA provide local climate reconstructions of summer temperature for the past millennium and the Holocene respectively. The performance of the probabilistic model is generally similar in comparison to MAT-derived reconstructions using the same data. Furthermore, the combination of co-location and precise dating for the three fossil sites in Wisconsin allows us to study the issue of site-specific uncertainty and to test the assumption of ergodicity in a real-world example. A multivariate ensemble kernel dressing approach derived from the post-processing of climate simulations reveals that the overall interpretation based on the individual reconstructions remains essentially unchanged, but the single-site reconstructions underestimate the overall uncertainty.

  10. Cytochemical localization of some hydrolases in the pollen and pollen tubes of Amaryllis vittata Ait.

    PubMed

    Sharma, D

    1982-01-01

    Some hydrolases are localized cytochemically in the pollen and pollen tubes of Amaryllis vittata Ait. The function of different enzymes is discussed in relation to pollen tubes morphogenesis. Activity of most of the enzymes was confined to colpus region, pollen wall and general cytoplasm of pollen and pollen tube. The activity of hydrolytic enzymes like acid monophosphoesterase and lipase and was nil in the exine of both germinated and ungerminated pollen, whereas intense reaction for esterase was observed in exine. Enzyme activity increased after germination which suggest the hydrolysis of stored metabolites and synthesis of proteins and other metabolites for the active growth of pollen tube. Intense reaction for enzymes like alkaline phosphomonoesterase, ATP-ase, 5-nucleotidase etc. at the tip region of pollen tube suggest their role in physiological processes associated with exchange of materials through intercellular transport during tube wall polysaccharide biogenesis. PMID:6298081

  11. A new approach used to explore associations of current Ambrosia pollen levels with current and past meteorological elements.

    PubMed

    Matyasovszky, István; Makra, László; Csépe, Zoltán; Deák, Áron József; Pál-Molnár, Elemér; Fülöp, Andrea; Tusnády, Gábor

    2015-09-01

    The paper examines the sensitivity of daily airborne Ambrosia (ragweed) pollen levels of a current pollen season not only on daily values of meteorological variables during this season but also on the past meteorological conditions. The results obtained from a 19-year data set including daily ragweed pollen counts and ten daily meteorological variables are evaluated with special focus on the interactions between the phyto-physiological processes and the meteorological elements. Instead of a Pearson correlation measuring the strength of the linear relationship between two random variables, a generalised correlation that measures every kind of relationship between random vectors was used. These latter correlations between arrays of daily values of the ten meteorological elements and the array of daily ragweed pollen concentrations during the current pollen season were calculated. For the current pollen season, the six most important variables are two temperature variables (mean and minimum temperatures), two humidity variables (dew point depression and rainfall) and two variables characterising the mixing of the air (wind speed and the height of the planetary boundary layer). The six most important meteorological variables before the current pollen season contain four temperature variables (mean, maximum, minimum temperatures and soil temperature) and two variables that characterise large-scale weather patterns (sea level pressure and the height of the planetary boundary layer). Key periods of the past meteorological variables before the current pollen season have been identified. The importance of this kind of analysis is that a knowledge of the past meteorological conditions may contribute to a better prediction of the upcoming pollen season. PMID:25376632

  12. A new approach used to explore associations of current Ambrosia pollen levels with current and past meteorological elements

    NASA Astrophysics Data System (ADS)

    Matyasovszky, István; Makra, László; Csépe, Zoltán; Deák, Áron József; Pál-Molnár, Elemér; Fülöp, Andrea; Tusnády, Gábor

    2015-09-01

    The paper examines the sensitivity of daily airborne Ambrosia (ragweed) pollen levels of a current pollen season not only on daily values of meteorological variables during this season but also on the past meteorological conditions. The results obtained from a 19-year data set including daily ragweed pollen counts and ten daily meteorological variables are evaluated with special focus on the interactions between the phyto-physiological processes and the meteorological elements. Instead of a Pearson correlation measuring the strength of the linear relationship between two random variables, a generalised correlation that measures every kind of relationship between random vectors was used. These latter correlations between arrays of daily values of the ten meteorological elements and the array of daily ragweed pollen concentrations during the current pollen season were calculated. For the current pollen season, the six most important variables are two temperature variables (mean and minimum temperatures), two humidity variables (dew point depression and rainfall) and two variables characterising the mixing of the air (wind speed and the height of the planetary boundary layer). The six most important meteorological variables before the current pollen season contain four temperature variables (mean, maximum, minimum temperatures and soil temperature) and two variables that characterise large-scale weather patterns (sea level pressure and the height of the planetary boundary layer). Key periods of the past meteorological variables before the current pollen season have been identified. The importance of this kind of analysis is that a knowledge of the past meteorological conditions may contribute to a better prediction of the upcoming pollen season.

  13. Pollen selection under acid rain stress

    SciTech Connect

    Zhang, Y.

    1994-01-01

    To investigate whether acid rain stress induces pollen selection in nature, three different approaches were used, based on the assumption that the response of pollen grains to acid rain is controlled by an acid sensitive gene product. Germination of pollen from homozygous and heterozygous individuals under acid rain stress was examined to detect any differences in rate of germination between populations of homogeneous and heterogeneous pollen grains. In vitro and in vivo bulked segregant analysis using RAPDs was used to search for differences in DNA constitution between the survivors of acid rain stressed and non-acid rain stressed pollen populations in vitro and between the progenies of acid rain stressed and non-acid rain stressed populations during pollination, respectively. No evidence for the pollen selection under acid rain stress was obtained in any of the test systems. Inhibition of protein synthesis using cycloheximide led to significant reduction of tube elongation at 4 hr and had no effect on pollen germination at any time interval tested. Total proteins extracted from control and acid rain stressed pollen grain populations exhibited no differences. The reduction of corn pollen germination in vitro under acid rain stress was mainly due to pollen rupture. The present data indicates the reduction of pollen germination and tube growth under acid rain stress may be a physiological response rather than a genetic response. A simple, nontoxic, and effective method to separate germinated from ungerminated pollen grains has been developed using pollen from corn (Zea mays, L. cv. Pioneer 3747). The separated germinated pollen grains retained viability and continued tube growth when placed in culture medium.

  14. Linking pollinator visitation rate and pollen receipt.

    PubMed

    Cayenne Engel, E; Irwin, Rebecca E

    2003-11-01

    The majority of flowering plants require animals for pollination, a critical ecosystem service in natural and agricultural systems. However, quantifying useful estimates of pollinator visitation rates can be nearly impossible when pollinator visitation is infrequent. We examined the utility of an indirect measure of pollinator visitation, namely pollen receipt by flowers, using the hummingbird-pollinated plant, Ipomopsis aggregata (Polemoniaceae). Our a priori hypothesis was that increased pollinator visitation should result in increased pollen receipt by stigmas. However, the relationship between pollinator visitation rate and pollen receipt may be misleading if pollen receipt is a function of both the number of pollinator visits and variation in pollinator efficiency at depositing pollen, especially in the context of variable floral morphology. Therefore, we measured floral and plant characters known to be important to pollinator visitation and/or pollen receipt in I. aggregata (corolla length and width and plant height) and used path analysis to dissect and compare the effect of pollinator visitation rate vs. pollinator efficiency on pollen receipt. Of the characters we measured, pollinator visitation rate (number of times plants were visited multiplied by the mean percentage of flowers probed per visit) had the strongest direct positive effect on pollen receipt, explaining 36% of the variation in pollen receipt. Plant height had a direct positive effect on pollinator visitation rate and an indirect positive effect on pollen receipt. Despite the supposition that floral characters would directly affect pollen receipt as a result of changes in pollinator efficiency, corolla length and width only weakly affected pollen receipt. These results suggest a direct positive link between pollinator visitation rate and pollen receipt across naturally varying floral morphology in I. aggregata. Understanding the relationship between pollinator visitation rate and pollen

  15. PHARUS airborne SAR concept

    NASA Astrophysics Data System (ADS)

    Snoeij, Paul; Pouwels, Henk; Koomen, Peter J.; Hoogeboom, Peter

    1995-11-01

    to ingest raw data from other SARs on the input side. The combination of the airborne and the ground segment, augmented by the transfer of technological knowledge needed to operate the system, will provide for an autonomous capability of the system user/owner. The PHARUS project has so far resulted in the construction of a C-band, VV-polarized research SAR (PHARS) with a 1- look resolution of 1.5 multiplied by 5 meter (5 multiplied by 5 meter at 7 independent looks) and a swath width of 6 km. This system has been extensively used for research and application projects in Europe, for purposes of mapping, land use inventory, change detection, coastal bathymetry, ship detection and ocean wave measurement. The next system recently completed is a fully polarimetric C-band system with adjustable resolution and swath width (the latter up to 20 km); this system is expected to be operational autumn 1995. The polarimetric capability will provide for a much enhanced discerning power (discrimination between e.g. forest/cultivated, various forest types, etc.). Discrimination by polarimetric signature is an alterative approach, with different possibilities and limitations, to e.g. the use of several frequencies. This paper gives an overview of the SAR research system and the results obtained with this system. The PHARUS design and use are discussed.

  16. Interspecific mating in the Piriqueta caroliniana (Turneraceae) complex: effects of pollen load size and composition.

    PubMed

    Wang, J; Cruzan, M

    1998-08-01

    Two taxa of Piriqueta (P. caroliniana and P. viridis) form a broad hybrid zone that extends over much of the central Florida peninsula. We used genetic markers to examine the strength of the isolation barriers between these taxa and the patterns of mating at the initial stages of hybridization. Regression models were employed to analyze the effects of pollen load size and the proportions of intra- and interspecific pollen on the frequency of first-generation (F1) hybrid formation. Overall, the postpollination mating barriers between these two taxa were relatively weak. However, there were significant effects of pollen load composition and size on the patterns of hybridization in both taxa with frequency-dependent responses to composition in both taxa. The frequency of F1 hybrid formation was generally lower than expected based on the frequency of each pollen type on the stigma for P. caroliniana recipients. The lower frequencies of F1 seeds in this taxon were apparently due to a greater competitive ability for intraspecific pollen, since hybrid seed formation decreased with increasing pollen load size. Pollen from P. caroliniana donors was also competitively superior on P. viridis recipients, leading to higher than expected frequencies of hybrid seed formation. Pollen from P. caroliniana did suffer higher rates of pollen-tube attrition than intraspecific pollen on P. viridis recipients, so the frequency of hybrid seed formation would be lower when pellen load sizes were small. In general, reproductive isolation mechanisms were stronger in P. caroliniana, suggesting that introgression should occur into P. viridis when these taxa come into close contact. Comparison of these expected patterns of mating to the distribution of hybrid genotypes in Florida provides insights into the relative roles of mating and selection in the evolution of hybrid populations of Piriqueta. PMID:21685002

  17. Pollution by Urticaceae pollen-influence of selected air pollutants and meteorological parameters.

    PubMed

    Sabo, Nataša Čamprag; Kiš, Tibor; Janaćković, Peđa; Đorđević, Dragana; Popović, Aleksandar

    2016-05-01

    The goal of this study was to analyze the influence of pollutants (concentrations of NO2, SO2, and soot in the air) and meteorological parameters (air temperature, humidity, wind speed, air pressure, cloud index) on Urticaceae pollen type emission measured in the region of Subotica, Serbia. The concentrations of the air pollutants, Urticaceae pollen, and meteorological parameters were measured over a 5-year period (2009-2013), followed by a statistical analysis of the values obtained. For most of the years examined, the concentration of NO2 correlates significantly with the concentration of Urticaceae pollen type. It was also established that air temperature, humidity, wind speed, atmospheric pressure, and cloud index have an influence on Urticaceae pollen type emission, while SO2 and soot do not contribute. PMID:26865493

  18. Forecasting daily pollen concentrations using data-driven modeling methods in Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Voukantsis, Dimitris; Niska, Harri; Karatzas, Kostas; Riga, Marina; Damialis, Athanasios; Vokou, Despoina

    2010-12-01

    Airborne pollen have been associated with allergic symptoms in sensitized individuals, having a direct impact on the overall quality of life of a considerable fraction of the population. Therefore, forecasting elevated airborne pollen concentrations and communicating this piece of information to the public are key issues in prophylaxis and safeguarding the quality of life of the overall population. In this study, we adopt a data-oriented approach in order to develop operational forecasting models (1-7 days ahead) of daily average airborne pollen concentrations of the highly allergenic taxa: Poaceae, Oleaceae and Urticaceae. The models are developed using a representative dataset consisting of pollen and meteorological time-series recorded during the years 1987-2002, in the city of Thessaloniki, Greece. The input variables (features) of the models have been optimized by making use of genetic algorithms, whereas we evaluate the performance of three algorithms: i) multi-Layer Perceptron, ii) support vector regression and iii) regression trees originating from distinct domains of Computational Intelligence (CI), and compare the resulting models with traditional multiple linear regression models. Results show the superiority of CI methods, especially when forecasting several days ahead, compared to traditional multiple linear regression models. Furthermore, the CI models complement each other, resulting to a combined model that performs better than each one separately. The overall performance ranges, in terms of the index of agreement, from 0.85 to 0.93 clearly suggesting the potential operational use of the models. The latter ones can be utilized in provision of personalized and on-time information services, which can improve quality of life of sensitized citizens.

  19. Pollen-Associated Microbiome Correlates with Pollution Parameters and the Allergenicity of Pollen.

    PubMed

    Obersteiner, Andrea; Gilles, Stefanie; Frank, Ulrike; Beck, Isabelle; Häring, Franziska; Ernst, Dietrich; Rothballer, Michael; Hartmann, Anton; Traidl-Hoffmann, Claudia; Schmid, Michael

    2016-01-01

    Pollen allergies have been rapidly increasing over the last decades. Many allergenic proteins and non-allergenic adjuvant compounds of pollen are involved in the plant defense against environmental or microbial stress. The first aim of this study was to analyze and compare the colonizing microbes on allergenic pollen. The second aim was to investigate detectable correlations between pollen microbiota and parameters of air pollution or pollen allergenicity. To reach these aims, bacterial and fungal DNA was isolated from pollen samples of timothy grass (Phleum pratense, n = 20) and birch trees (Betula pendula, n = 55). With this isolated DNA, a terminal restriction fragment length polymorphism analysis was performed. One result was that the microbial diversity on birch tree and timothy grass pollen samples (Shannon/Simpson diversity indices) was partly significantly correlated to allergenicity parameters (Bet v 1/Phl p 5, pollen-associated lipid mediators). Furthermore, the microbial diversity on birch pollen samples was correlated to on-site air pollution (nitrogen dioxide (NO2), ammonia (NH3), and ozone (O3)). What is more, a significant negative correlation was observed between the microbial diversity on birch pollen and the measured NO2 concentrations on the corresponding trees. Our results showed that the microbial composition of pollen was correlated to environmental exposure parameters alongside with a differential expression of allergen and pollen-associated lipid mediators. This might translate into altered allergenicity of pollen due to environmental and microbial stress. PMID:26910418

  20. Pollen-Associated Microbiome Correlates with Pollution Parameters and the Allergenicity of Pollen

    PubMed Central

    Obersteiner, Andrea; Gilles, Stefanie; Frank, Ulrike; Beck, Isabelle; Häring, Franziska; Ernst, Dietrich; Rothballer, Michael; Hartmann, Anton; Traidl-Hoffmann, Claudia; Schmid, Michael

    2016-01-01

    Pollen allergies have been rapidly increasing over the last decades. Many allergenic proteins and non-allergenic adjuvant compounds of pollen are involved in the plant defense against environmental or microbial stress. The first aim of this study was to analyze and compare the colonizing microbes on allergenic pollen. The second aim was to investigate detectable correlations between pollen microbiota and parameters of air pollution or pollen allergenicity. To reach these aims, bacterial and fungal DNA was isolated from pollen samples of timothy grass (Phleum pratense, n = 20) and birch trees (Betula pendula, n = 55). With this isolated DNA, a terminal restriction fragment length polymorphism analysis was performed. One result was that the microbial diversity on birch tree and timothy grass pollen samples (Shannon/Simpson diversity indices) was partly significantly correlated to allergenicity parameters (Bet v 1/Phl p 5, pollen-associated lipid mediators). Furthermore, the microbial diversity on birch pollen samples was correlated to on-site air pollution (nitrogen dioxide (NO2), ammonia (NH3), and ozone (O3)). What is more, a significant negative correlation was observed between the microbial diversity on birch pollen and the measured NO2 concentrations on the corresponding trees. Our results showed that the microbial composition of pollen was correlated to environmental exposure parameters alongside with a differential expression of allergen and pollen-associated lipid mediators. This might translate into altered allergenicity of pollen due to environmental and microbial stress. PMID:26910418

  1. Pollen, Tapetum, and Orbicule Development in Colletia paradoxa and Discaria americana (Rhamnaceae)

    PubMed Central

    Gotelli, M.; Galati, B.; Medan, D.

    2012-01-01

    Tapetum, orbicule, and pollen grain ontogeny in Colletia paradoxa and Discaria americana were studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage. PMID:22645479

  2. Mineral content of commercial pollen.

    PubMed

    Orzáez Villanueva, M T; Díaz Marquina, A; Bravo Serrano, R; Blaźquez Abellán, G

    2001-05-01

    Pollen is a natural product which is extending its marketing day by day, given that it is considered to be a dietetic product and it is consumed everyday by a broad sector of the Spanish population. In its composition it presents valuable nutrients, among which we can find minerals, which is the main object of this study. We have analysed sodium, potassium, magnesium, copper, iron, manganese and zinc in 15 pollen samples which correspond to different brands. The technique we have used is atomic absortion spectroscopy. The results show us the great potassium contribution of this natural product, with values over 400 mg/100 g, and about microelements, mainly iron and zinc, although with different results, depending on the brand which markets it, with average values of 4.01 +/- 1.00 and 3.66 +/- 1.02, respectively. PMID:11400473

  3. Effects of Ambient Pollen Concentrations on Frequency and Severity of Asthma Symptoms Among Asthmatic Children

    PubMed Central

    Triche, Elizabeth W.; Leaderer, Brian P.; Bell, Michelle L.

    2011-01-01

    Background Previous studies on the associations between ambient pollen exposures and daily respiratory symptoms have produced inconsistent results. We investigated these relationships in a cohort of asthmatic children, using pollen exposure models to estimate individual ambient exposures. Methods Daily symptoms of wheeze, night symptoms, shortness of breath, chest tightness, persistent cough and rescue medication use were recorded in a cohort of 430 children age 4-12 years with asthma in Connecticut, Massachusetts and New York. Daily ambient exposures to tree, grass, weed and all-type pollen were estimated using mixed effects models. We stratified analyses by asthma maintenance medication and sensitization to grass or weed pollens. Separate logistic regression analysis using generalized estimating equations were performed for each symptom outcome and pollen type. We adjusted analyses for maximum daily temperature, maximum 8-hr average ozone, fine particles (PM2.5), season and antibiotic use. Results Associations were observed among children sensitized to specific pollens; these associations varied by use of asthma maintenance medication. Exposures to even relatively low levels of weed pollen (6-9 grains/m3) were associated with increased shortness of breath, chest tightness, rescue medication use, wheeze, and persistent cough, compared with lower exposure among sensitized children taking maintenance medication. Grass pollen exposures ≥2 grains/m3 were associated with wheeze, night symptoms, shortness of breath and persistent cough compared with lower exposure among sensitized children who did not take maintenance medication. Conclusion Even low-level pollen exposure was associated with daily asthmatic symptoms. PMID:22082997

  4. Pollen and ovule development in Arabidopsis thaliana under spaceflight conditions

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Musgrave, M. E.; Matthews, S. W.; Cummins, D. B.; Tucker, S. C.

    1995-01-01

    The development of pollen and ovules in Arabidopsis thaliana on the space shuttle 'Endeavour' (STS-54) was investigated. Plants were grown on nutrient agar for 14 days prior to loading into closed plant growth chambers that received light and temperature control inside the Plant Growth Unit flight hardware on the shuttle middeck. After 6 days in spaceflight the plants were retrieved and immediately dissected and processed for light and electron microscope observation. Reproductive development aborted at an early stage. Pistils were collapsed and ovules inside were seen to he empty. No viable pollen was observed from STS-54 plants; young microspores were deformed and empty. At a late stage, the cytoplasm of the pollen contracted and became disorganized, but the pollen wall developed and the exine appeared normal. The tapetum in the flight flowers degenerated at early stages. Ovules from STS-54 flight plants stopped growing and the integuments and nucellus collapsed and degenerated. The megasporocytes appeared abnormal and rarely underwent meiosis. Apparently they enlarged, or occasionally produced a dyad or tetrad, to assume the form of a female gametophyte with the single nucleus located in an egglike cell that lacks a cell wall. Synergids, polar nuclei, and antipodals were not observed. The results demonstrate the types of lesions occurring in plant reproductive material under spaceflight conditions.

  5. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model: a pollen production model for regional emission and transport modeling

    NASA Astrophysics Data System (ADS)

    Duhl, T. R.; Zhang, R.; Guenther, A.; Chung, S. H.; Salam, M. T.; House, J. M.; Flagan, R. C.; Avol, E. L.; Gilliland, F. D.; Lamb, B. K.; VanReken, T. M.; Zhang, Y.; Salathé, E.

    2013-04-01

    A pollen model that simulates the timing and production of wind-dispersed allergenic pollen by terrestrial, temperate vegetation has been developed to quantify how pollen occurrence may be affected by climate change and to investigate how pollen can interact with anthropogenic pollutants to affect human health. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model is driven by local meteorological conditions and is designed to be sensitive to climate shifts, as well as flexible with respect to the vegetation species and plant functional types (trees, grasses, etc.) represented and the climate zones simulated. The initial focus for the model is the simulation of the pollen emission potential of important allergenic tree and grass species that typically flower between March-June in Southern California (S. CA), which is characterized by moderate Mediterranean and oceanic climate zones as well as regions of arid desert and arid steppe. Vegetation cover and species composition data are obtained from numerous datasets and a database of allergenic vegetation species, their pollen production potential and relative allergenicities has been developed. For the selected allergenic species and spring-early summer simulation period, temperature is the main driver controlling the timing of pollen release, while precipitation (and temperature, for some species) controls the magnitude of pollen produced. The model provides species-specific pollen potential maps for each day of the simulation period; these are then used by a pollen transport model to simulate ambient pollen concentrations as described in a companion paper (Zhang et al., 2013a), which also presents model evaluation results for the S. CA model domain. The STaMPS model was also used to quantify the possible impact of climate change on pollen season under the IPCC SRES A1B scenario as simulated by the ECHAM5 global climate model. Current (1995-2004) and future (2045-2054) meteorological conditions

  6. Ultrastructure and pollen morphology of Bromeliaceae species from the Atlantic Rainforest in Southeastern Brazil.

    PubMed

    Silva, Vanessa J D; Ribeiro, Ester M; Luizi-Ponzo, Andrea P; Faria, Ana Paula G

    2016-01-01

    Pollen grain morphology of Bromeliaceae species collected in areas of the Atlantic Rainforest of southeastern Brazil was studied. The following species were analyzed: Aechmea bambusoides L.B.Sm. & Reitz, A. nudicaulis (L.) Griseb., A. ramosa Mart. ex Schult.f., Ananas bracteatus (Lindl.) Schult.f., Billbergia distachia (Vell.) Mez, B. euphemiae E. Morren, B. horrida Regel, B. zebrina (Herb.) Lindl., Portea petropolitana (Wawra) Mez, Pitcairnia flammea Lindl., Quesnelia indecora Mez, Tillandsia polystachia (L.) L., T. stricta Sol., T. gardneri Lindl., T. geminiflora Brongn. and Vriesea grandiflora Leme. Light and scanning electron microscopy were used and the species were grouped into three pollen types, organized according to aperture characteristics: Type I - pantoporate pollen grains observed in P. petropolitana, Type II - 2-porate pollen grains, observed in the genera Ananas, Aechmea and Quesnelia, and Type III - 1-colpate pollen grains, observed in the genera Billbergia, Pitcairnia, Tillandsia and Vriesea. Pollen data led to the construction of an identification key. The results showed that the species analyzed can be distinguished using mainly aperture features and exine ornamentation, and that these characteristics may assist in taxonomic studies of the family. PMID:27168370

  7. Honey Pollen: Using Melissopalynology to Understand Foraging Preferences of Bees in Tropical South India

    PubMed Central

    Ponnuchamy, Raja; Bonhomme, Vincent; Prasad, Srinivasan; Das, Lipi; Patel, Prakash; Gaucherel, Cédric; Pragasam, Arunachalam; Anupama, Krishnamurthy

    2014-01-01

    The aim of the study was to use melissopalynology to delineate the foraging preferences of bees in tropical environs. This was done by comparing pollen spectra obtained from the same hives every three months for three years at four sampling locations (in two sites) within a confined landscape mosaic. If melissopalynology is highly replicable, the spatial variation of the pollen spectrum from the honey samples would be much more than the temporal (inter-annual) variations. In other words, given the three factors, Month, Year and Location, honey pollen from different Locations, in a given Year and Month, would be much less similar than samples from different Years, in a given Location and Month. We then determined how the factors, Month, Year and Location, influenced the pollen influx of honey. The pollen analyses of the 42 honey samples collected during the three years yielded 80 pollen taxa/types: 72 dicotyledonous and 8 monocotyledonous, encompassing 41 botanical families spread into seven life forms namely, trees, shrubs, epiphytes, herbs, climbers, grasses, and sedges. Our results showed that pollen spectra were equally comparable between Locations and between Months and Years; the importance of this result is that it helped to demonstrate the complexity of ecological/environmental phenomena involved in the process of foraging by bees in a heterogeneous and complex landscape. PMID:25004103

  8. Honey pollen: using melissopalynology to understand foraging preferences of bees in tropical South India.

    PubMed

    Ponnuchamy, Raja; Bonhomme, Vincent; Prasad, Srinivasan; Das, Lipi; Patel, Prakash; Gaucherel, Cédric; Pragasam, Arunachalam; Anupama, Krishnamurthy

    2014-01-01

    The aim of the study was to use melissopalynology to delineate the foraging preferences of bees in tropical environs. This was done by comparing pollen spectra obtained from the same hives every three months for three years at four sampling locations (in two sites) within a confined landscape mosaic. If melissopalynology is highly replicable, the spatial variation of the pollen spectrum from the honey samples would be much more than the temporal (inter-annual) variations. In other words, given the three factors, Month, Year and Location, honey pollen from different Locations, in a given Year and Month, would be much less similar than samples from different Years, in a given Location and Month. We then determined how the factors, Month, Year and Location, influenced the pollen influx of honey. The pollen analyses of the 42 honey samples collected during the three years yielded 80 pollen taxa/types: 72 dicotyledonous and 8 monocotyledonous, encompassing 41 botanical families spread into seven life forms namely, trees, shrubs, epiphytes, herbs, climbers, grasses, and sedges. Our results showed that pollen spectra were equally comparable between Locations and between Months and Years; the importance of this result is that it helped to demonstrate the complexity of ecological/environmental phenomena involved in the process of foraging by bees in a heterogeneous and complex landscape. PMID:25004103

  9. Grass pollen immunotherapy: where are we now.

    PubMed

    Würtzen, Peter A; Gupta, Shashank; Brand, Stephanie; Andersen, Peter S

    2016-04-01

    During allergen immunotherapy (AIT), the allergic patient is exposed to the disease-inducing antigens (allergens) in order to induce clinical and immunological tolerance and obtain disease modification. Large trials of grass AIT with highly standardized subcutaneous and sublingual tablet vaccines have been conducted to document the clinical effect. Induction of blocking antibodies as well as changes in the balance between T-cell phenotypes, including induction of regulatory T-cell subtypes, have been demonstrated for both treatment types. These observations increase the understanding of the immunological mechanism behind the clinical effect and may make it possible to use the immunological changes as biomarkers of clinical effect. The current review describes the recent mechanistic findings for subcutaneous immunotherapy and sublingual immunotherapy/tablet treatment and discusses how the observed immunological changes translate into a scientific foundation for the observed clinical effects of grass pollen immunotherapy and lead to new treatment strategies for grass AIT. PMID:26973122

  10. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.)

    PubMed Central

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media. PMID:25405230

  11. Ragweed pollen source inventory for France - The second largest centre of Ambrosia in Europe

    NASA Astrophysics Data System (ADS)

    Thibaudon, Michel; Šikoparija, Branko; Oliver, Gilles; Smith, Matt; Skjøth, Carsten A.

    2014-02-01

    France, in particular the Rhône-Alpes region, is one of the three main centres of ragweed (Ambrosia) in Europe. The aim of this study is to develop a gridded ragweed pollen source inventory for all of France that can be used in assessments, eradication plans and by atmospheric models for describing concentrations of airborne ragweed pollen. The inventory combines information about spatial variations in annual Ambrosia pollen counts, knowledge of ragweed ecology, detailed land cover information and a Digital Elevation Model. The ragweed inventory consists of a local infection level on a scale of 0-100% (where 100% is the highest plant abundance per area in the studied region) and a European infection level between 0% and 100% (where 100% relates to the highest identified plant abundance in Europe using the same methodology) that has been distributed onto the EMEP grid with 5 km × 5 km resolution. The results of this analysis showed that some of the highest mean annual ragweed pollen concentrations were recorded at Roussillon in the Rhône-Valley. This is reflected by the inventory, where the European infection level has been estimated to reach 67.70% of the most infected areas in Europe i.e. Kecskemét in central Hungary. The inventory shows that the Rhône Valley is the most heavily infected part of France. Central France is also infected, but northern and western parts of France are much less infected. The inventory can be entered into atmospheric transport models, in combination with other components such as a phenological model and a model for daily pollen release, in order to simulate the dispersion of ragweed pollen within France as well as potential long-distance transport from France to other European countries.

  12. Synoptic and meteorological characterisation of olive pollen transport in Córdoba province (south-western Spain)

    NASA Astrophysics Data System (ADS)

    Hernández-Ceballos, Miguel A.; García-Mozo, Hermínia; Adame, José Antonio; Domínguez-Vilches, Eugenio; de La Morena, Benito A.; Bolívar, Juan Pedro; Galán, Carmen

    2011-01-01

    The main goal of the present study was to provide a detailed analysis of olive pollen transport dynamics in the province of Córdoba (south-western Spain) by applying back-trajectory analysis. Pollen data from 2006 and 2007 were analysed at four monitoring sites: Córdoba city in the centre of the province, Baena and Priego de Córdoba located in the south, and El Cabril reserve (Hornachuelos Natural Park) in the north. Particular attention was paid to nine episodes of high pollen counts. Synoptic surface maps were used, and kinematic back-trajectories (3D) were computed using the hybrid single particle Lagrangian integrated trajectory model (HYSPLIT) at 500 m above ground level, run with a time-step of 6 h over a period of 36 h. Findings were analysed in conjunction with daily and bi-hourly airborne pollen data, field phenological data and hourly surface meteorological data recorded at nearby stations: temperature, relative humidity, rainfall, wind direction and wind speed. The results identified two pollen source areas over the Córdoba province, the largest one located in the south, affecting Baena, Priego de Córdoba and Córdoba city, and one smaller located in the west, which determines mainly the pollen cycle over the north of the province, El Cabril. In addition, two air mass circulations were found, one coming from the south and crossing the main olive pollen sources very close to the surface and being frequently associated with higher pollen counts, and the other coming from the west and, in the episodes investigated, influencing mainly the north of the province.

  13. Use of MODIS Satellite Data to Evaluate Juniperus spp. Pollen Phenology to Support a Pollen Dispersal Model, PREAM, to Support Public Health Allergy Alerts

    NASA Technical Reports Server (NTRS)

    Luvall, J. C.; Sprigg, W.; Levetin, E.; Huete, A.; Nickovic, S.; Pejanovic, G. A.; Vukovic, A.; VandeWater, P.; Budge, A.; Hudspeth, W.; Krapfl, H.; Toth, B.; Zelicoff, A.; Myers, O.; Bunderson, L.; Ponce-Campos, G.; Crimmins, T.; Menache, M.

    2012-01-01

    Juniperus spp. pollen is a significant aeroallergen that can be transported 200-600 km from the source. Local observations of Juniperus spp. phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. Methods: The Dust REgional Atmospheric Model (DREAM)is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and quantities of dust. We successfully modified the DREAM model to incorporate pollen transport (PREAM) and used MODIS satellite images to develop Juniperus ashei pollen input source masks. The Pollen Release Potential Source Map, also referred to as a source mask in model applications, may use different satellite platforms and sensors and a variety of data sets other than the USGS GAP data we used to map J. ashei cover type. MODIS derived percent tree cover is obtained from MODIS Vegetation Continuous Fields (VCF) product (collection 3 and 4, MOD44B, 500 and 250 m grid resolution). We use updated 2010 values to calculate pollen concentration at source (J. ashei ). The original MODIS derived values are converted from native approx. 250 m to 990m (approx. 1 km) for the calculation of a mask to fit the model (PREAM) resolution. Results: The simulation period is chosen following the information that in the last 2 weeks of December 2010. The PREAM modeled near-surface concentrations (Nm-3) shows the transport patterns of J. ashei pollen over a 5 day period (Fig. 2). Typical scales of the simulated transport process are regional.

  14. The Unique Pollen Morphology of Duparquetia (Leguminosae: Caesalpinioideae): Developmental Evidence of Aperture Orientation Using Confocal Microscopy

    PubMed Central

    BANKS, HANNAH; FEIST-BURKHART, SUSANNE; KLITGAARD, BENTE

    2006-01-01

    legume pollen types. PMID:16735411

  15. Arabidopsis mutant of AtABCG26, an ABC transporter gene, is defective in pollen maturation.

    PubMed

    Kuromori, Takashi; Ito, Takuya; Sugimoto, Eriko; Shinozaki, Kazuo

    2011-11-01

    In plants, pollen is the male gametophyte that is generated from microspores, which are haploid cells produced after meiosis of diploid pollen mother cells in floral anthers. In normal maturation, microspores interact with the tapetum, which consists of one layer of metabolically active cells enclosing the locule in anthers. The tapetum plays several important roles in the maturation of microspores. ATP-binding cassette (ABC) transporters are a highly conserved protein super-family that uses the energy released in ATP hydrolysis to transport substrates. The ABC transporter gene family is more diverse in plants than in animals. Previously, we reported that an Arabidopsis half-size type ABC transporter gene, COF1/AtWBC11/AtABCG11, is involved in lipid transport for the construction of cuticle layers and pollen coats in normal organ formation, as compared to CER5/AtWBC12/AtABCG12. However, physiological functions of most other ABCG members are unknown. Here, we identified another family gene, AtABCG26, which is required for pollen development in Arabidopsis. An AtABCG26 mutant developed very few pollen grains, resulting in a male-sterile phenotype. By investigating microspore and pollen development in this mutant, we observed that there was a slight abnormality in tetrad morphology prior to the formation of haploid microspores. At a later stage, we could not detect exine deposition on the microspore surface. During pollen maturation, many grains in the mutant anthers got aborted, and surviving grains were found to be defective in mitosis. Transmission of the mutant allele through male gametophytes appeared to be normal in genetic transmission analysis, supporting the view that the pollen function was disturbed by sporophytic defects in the AtABCG26 mutant. AtABCG26 can be expected to be involved in the transport of substrates such as sporopollenin monomers from tapetum to microspores, which both are plant-specific structures critical to pollen development. PMID

  16. [Pollen morphology in species of Canna (Cannaceae), and systematics implications].

    PubMed

    Ciciarelli, María de las Mercedes; Passarelli, Lilian M; Rolleri, Cristina H

    2010-03-01

    The morphology of pollen grains of eight taxa of Canna, C. ascendens, C. coccinea, C compacta, C. glauca, C. indica, C. paniculata, C. variegatifolia and C. fuchsina, an unpublished new species, were studied using light and scanning electronic microscopes. We used the Wodehouse technique on samples of 20 grains per specimen to measure the intine with a light microscope; and the density of spines (in 400 microm2 fields) with scanning electronic microscopy. Pollen grains are spherical, echinate, omniaperturate. The sporoderm presents a very thin exine covering a thicker intine. Corrugate micro-perforate, sub-reticulate, rugate, rugulate, striate to folded, micro-striate, micro-granulate, and smooth types of the external surface of the sporoderm were found. The spines consist of exine, partially to completely covered by tryphine. The two-layered intine is the thicker part of the wall. Echinate ornamentation is a generic character in Canna, but size, surface and color of pollen walls, and density and shape of spines, are diagnostic for species. Pollen morphology supports the view of C. indica and C. coccinea as different species. Canna fuchsina grows in wild, dense colonies, in humid riverside forests from Buenos Aires and Santa Fe Provinces, Argentina; its characters suggest relationships with a not well known group of taxa, some of them hybrids, such as C. x generalis. However, as these plants showed normal, well formed grains, close to those of C. coccinea, that germinate over the stigmatic surfaces in fresh flowers, we decided to include their pollen in this study. PMID:20411707

  17. Surface pollen and its relationship to vegetation in the Zoige Basin, eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Li, Furong; Zhao, Yan; Sun, Jinghui; Zhao, Wenwei; Guo, Xiaoli; Zhang, Ke

    2011-09-01

    We use a data set of 23 surface pollen samples from moss polsters in the Zoige Basin to explore the relationship between modern pollen assemblages and contemporary vegetation patterns. The surface pollen samples spanned four types of plant communities: Carex muliensis marsh, Stipa and Kobresia meadow, Carex-dominated forb meadow and Sibiraea angustata scrub. Principal-components analysis (PCA) was used to determine the relationships between modern pollen and vegetation and environmental variables. The results show that the pollen assemblages of surface moss samples generally reflect the features of the modern vegetation, basically similar in the vegetation types and the dominant genera; however, they don't show a very clear distinction between different communities. Our results also demonstrate that pollen representation of different families or genus varied. Some tree taxa, such as Pinus and Betula, and herb types, such as Artemisia are over-represented, while Asteraceae, Ranunculaceae and Cyperaceae are moderately represented, and Poaceae and Rosaceae are usually under-represented in our study region. PCA results indicate that the distribution of vegetation in the Zoige Basin is mainly controlled by precipitation and altitude.

  18. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The characteristics of an Airborne Oceanographic Lidar (AOL) are given. The AOL system is described and its potential for various measurement applications including bathymetry and fluorosensing is discussed.

  19. Pollen concentration and asthma exacerbations in Wake County, North Carolina, 2006-2012.

    PubMed

    Sun, Xuezheng; Waller, Anna; Yeatts, Karin B; Thie, Lauren

    2016-02-15

    Pollen has been generally linked to an increased risk for asthma exacerbation. However, the delayed effect (lag), the length of effect duration, and the association heterogeneity by pollen types have not been well characterized. Short-term associations between ambient concentration of various pollen types (tree, grass, and weed) and emergency department (ED) visits for asthma were assessed using data in Wake County, North Carolina, during 2006-2012. Distributed lag nonlinear models (DLNM) were used to characterize the associations, while adjusting for air pollutants, meteorological, and temporal factors. A strong association between same-day tree pollen and asthma ED visits was detected. This association lasted four days, with a 4-day cumulative risk ratio (RR) up to 2.10 (3500 grains/m(3) vs. 0 grains/m(3), 95% confidence interval [CI]=1.21-3.65). The associations of asthma ED visits with weed pollen and grass pollen were weak, suggestively starting from lag 2 and lasting 3 days, with the strongest association a 3-day cumulative RR of 1.08 (32 grains/m(3) vs. 0 grains/m(3), 95% CI=1.01-1.15) and 1.05 (11 grains/m(3) vs. 0 grains/m(3), 95% CI=1.00-1.11). Our results indicate that the association of ambient pollen and asthma exacerbation vary by pollen type, both quantitatively and temporally. These findings have important implications for optimizing targeted allergic disease prevention and management, and helping understand the etiology of ambient exposure-induced allergic diseases. PMID:26657364

  20. Specialized bees fail to develop on non-host pollen: do plants chemically protect their pollen?

    PubMed

    Praz, Christophe J; Müller, Andreas; Dorn, Silvia

    2008-03-01

    Bees require large amounts of pollen for their own reproduction. While several morphological flower traits are known to have evolved to protect plants against excessive pollen harvesting by bees, little is known on how selection to minimize pollen loss acts on the chemical composition of pollen. In this study, we traced the larval development of four solitary bee species, each specialized on a different pollen source, when reared on non-host pollen by transferring unhatched eggs of one species onto the pollen provisions of another species. Pollen diets of Asteraceae and Ranunculus (Ranunculaceae) proved to be inadequate for all bee species tested except those specialized on these plants. Further, pollen of Sinapis (Brassicaceae) and Echium (Boraginaceae) failed to support larval development in one bee species specialized on Campanula (Campanulaceae). Our results strongly suggest that pollen of these four taxonomic groups possess protective properties that hamper digestion and thus challenge the general view of pollen as an easy-to-use protein source for flower visitors. PMID:18459342

  1. Airborne Gamma-Spectrometry in Switzerland

    SciTech Connect

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-07

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of {sup 137}Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  2. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    PubMed Central

    Sénéchal, Hélène; Visez, Nicolas; Charpin, Denis; Shahali, Youcef; Peltre, Gabriel; Biolley, Jean-Philippe; Lhuissier, Franck; Couderc, Rémy; Yamada, Ohri; Malrat-Domenge, Audrey; Pham-Thi, Nhân; Poncet, Pascal; Sutra, Jean-Pierre

    2015-01-01

    This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed. PMID:26819967

  3. [Study of the coverage of pollen capture in Lyon over three seasons (1999, 2000, 2001)].

    PubMed

    Thibaudon, M; Burnichon, A; Deruaz, D; Laurent, O

    2002-05-01

    For the third consecutive year, the two sensors of the type HIRST of the National Network of aerobiology monitoring (RNSA) worked on the agglomeration of Lyon. The primary trap (Lyon 1) is located at 26 m height on a roof in southern zone of Lyon (district of Gerland), the second (Lyon 2) is located in northern zone of the city (district of Vaise) on a roof at 15 m height compared to the ground. The study of the daily variations of the pollinic counts over the first two years had shown a perfect parallelism for pollens of trees, Poaceae and Urticaceae. Only the curves of pollens of ambrosia presented different layouts between the two pollen traps. The study of this third year makes it possible to consolidate the proceeding results and to appreciate the value of the cover of a Hirst pollen trap in urban implantation within the framework of the allergo-pollinic monitoring. PMID:12108330

  4. Loss of the Arabidopsis thaliana P4-ATPases ALA6 and ALA7 impairs pollen fitness and alters the pollen tube plasma membrane.

    PubMed

    McDowell, Stephen C; López-Marqués, Rosa L; Cohen, Taylor; Brown, Elizabeth; Rosenberg, Alexa; Palmgren, Michael G; Harper, Jeffrey F

    2015-01-01

    Members of the P4 subfamily of P-type ATPases are thought to create and maintain lipid asymmetry in biological membranes by flipping specific lipids between membrane leaflets. In Arabidopsis, 7 of the 12 Aminophospholipid ATPase (ALA) family members are expressed in pollen. Here we show that double knockout of ALA6 and ALA7 (ala6/7) results in siliques with a ~2-fold reduction in seed set with a high frequency of empty seed positions near the bottom. Seed set was reduced to near zero when plants were grown under a hot/cold temperature stress. Reciprocal crosses indicate that the ala6/7 reproductive deficiencies are due to a defect related to pollen transmission. In-vitro growth assays provide evidence that ala6/7 pollen tubes are short and slow, with ~2-fold reductions in both maximal growth rate and overall length relative to wild-type. Outcrosses show that when ala6/7 pollen are in competition with wild-type pollen, they have a near 0% success rate in fertilizing ovules near the bottom of the pistil, consistent with ala6/7 pollen having short and slow growth defects. The ala6/7 phenotypes were rescued by the expression of either an ALA6-YFP or GFP-ALA6 fusion protein, which showed localization to both the plasma membrane and highly-mobile endomembrane structures. A mass spectrometry analysis of mature pollen grains revealed significant differences between ala6/7 and wild-type, both in the relative abundance of lipid classes and in the average number of double bonds present in acyl side chains. A change in the properties of the ala6/7 plasma membrane was also indicated by a ~10-fold reduction of labeling by lipophilic FM-dyes relative to wild-type. Together, these results indicate that ALA6 and ALA7 provide redundant activities that function to directly or indirectly change the distribution and abundance of lipids in pollen, and support a model in which ALA6 and ALA7 are critical for pollen fitness under normal and temperature-stress conditions. PMID:25954280

  5. Loss of the Arabidopsis thaliana P4-ATPases ALA6 and ALA7 impairs pollen fitness and alters the pollen tube plasma membrane

    PubMed Central

    McDowell, Stephen C.; López-Marqués, Rosa L.; Cohen, Taylor; Brown, Elizabeth; Rosenberg, Alexa; Palmgren, Michael G.; Harper, Jeffrey F.

    2015-01-01

    Members of the P4 subfamily of P-type ATPases are thought to create and maintain lipid asymmetry in biological membranes by flipping specific lipids between membrane leaflets. In Arabidopsis, 7 of the 12 Aminophospholipid ATPase (ALA) family members are expressed in pollen. Here we show that double knockout of ALA6 and ALA7 (ala6/7) results in siliques with a ~2-fold reduction in seed set with a high frequency of empty seed positions near the bottom. Seed set was reduced to near zero when plants were grown under a hot/cold temperature stress. Reciprocal crosses indicate that the ala6/7 reproductive deficiencies are due to a defect related to pollen transmission. In-vitro growth assays provide evidence that ala6/7 pollen tubes are short and slow, with ~2-fold reductions in both maximal growth rate and overall length relative to wild-type. Outcrosses show that when ala6/7 pollen are in competition with wild-type pollen, they have a near 0% success rate in fertilizing ovules near the bottom of the pistil, consistent with ala6/7 pollen having short and slow growth defects. The ala6/7 phenotypes were rescued by the expression of either an ALA6-YFP or GFP-ALA6 fusion protein, which showed localization to both the plasma membrane and highly-mobile endomembrane structures. A mass spectrometry analysis of mature pollen grains revealed significant differences between ala6/7 and wild-type, both in the relative abundance of lipid classes and in the average number of double bonds present in acyl side chains. A change in the properties of the ala6/7 plasma membrane was also indicated by a ~10-fold reduction of labeling by lipophilic FM-dyes relative to wild-type. Together, these results indicate that ALA6 and ALA7 provide redundant activities that function to directly or indirectly change the distribution and abundance of lipids in pollen, and support a model in which ALA6 and ALA7 are critical for pollen fitness under normal and temperature-stress conditions. PMID:25954280

  6. The pollen tube paradigm revisited.

    PubMed

    Kroeger, Jens; Geitmann, Anja

    2012-12-01

    The polar growth process characterizing pollen tube elongation has attracted numerous modeling attempts over the past years. While initial models focused on recreating the correct cellular geometry, recent models are increasingly based on experimentally assessed cellular parameters such as the dynamics of signaling processes and the mechanical properties of the cell wall. Recent modeling attempts have therefore substantially gained in biological relevance and predictive power. Different modeling methods are explained and the power and limitations of individual models are compared. Focus is on several recent models that use closed feedback loops in order to generate limit cycles representing the oscillatory behavior observed in growing tubes. PMID:23000432

  7. Polyamines in Pollen: From Microsporogenesis to Fertilization

    PubMed Central

    Aloisi, Iris; Cai, Giampiero; Serafini-Fracassini, Donatella; Del Duca, Stefano

    2016-01-01

    The entire pollen life span is driven by polyamine (PA) homeostasis, achieved through fine regulation of their biosynthesis, oxidation, conjugation, compartmentalization, uptake, and release. The critical role of PAs, from microsporogenesis to pollen–pistil interaction during fertilization, is suggested by high and dynamic transcript levels of PA biosynthetic genes, as well as by the activities of the corresponding enzymes. Moreover, exogenous supply of PAs strongly affects pollen maturation and pollen tube elongation. A reduction of endogenous free PAs impacts pollen viability both in the early stages of pollen development and during fertilization. A number of studies have demonstrated that PAs largely function by modulating transcription, by structuring pollen cell wall, by modulating protein (mainly cytoskeletal) assembly as well as by modulating the level of reactive oxygen species. Both free low-molecular weight aliphatic PAs, and PAs conjugated to proteins and hydroxyl-cinnamic acids take part in these complex processes. Here, we review both historical and recent evidence regarding molecular events underlying the role of PAs during pollen development. In the concluding remarks, the outstanding issues and directions for future research that will further clarify our understanding of PA involvement during pollen life are outlined. PMID:26925074

  8. Antioxidant Activity of Sonoran Desert Bee Pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bee products have been consumed by mankind since antiquity and their health benefits are becoming more apparent. Bee pollen (pollen collected by honey bees) was collected in the high intensity ultraviolet (UV) Sonoran desert and was analyzed by the anti-2,2-diphenyl-1-picryhydrazyl (DPPH) assay and...

  9. Impact of a city centre on the dispersal of a regional pollen cloud. Cas of Montréal, Canada.

    NASA Astrophysics Data System (ADS)

    Goyette-Pernot, J.

    2003-04-01

    Highly allergenic ragweed pollen is released into the air in large quantities at the end of every summer in and around Montreal. More than 19% of the city's population experiences hay fever (DSP-Montreal Center, 2000). The aim of this study is to obtain a deeper insight into the manner in which a North American urban area may influence the dispersal of a regional pollen clouds, how it modifies the dispersal and thereby its concentration. Downtown areas provide particular surface characteristics that result in strong disturbances to regional meteorological conditions. Strong pollen concentrations are modified by the passage of fronts and may increase the occurrence of regional-scale pollen peaks. They offer the best conditions for the local dilution of pollen and even the best dynamic conditions for external pollen that reaches Montreal from southern regions. On the contrary, anticyclonic situations seem to offer the best conditions for local production but inhibit dilution on a larger scale. Observations have been made in order to investigate the vertical as well as the regional versus the local and street-level differences in pollen abundance. The aim is to develop an original statistical downscaling technique, inferring pollen concentrations from the largest to the smallest scales. At the regional scale, the emphasis is placed on the typical meteorological conditions or weather types influencing the regional pollen cloud. At the street level, the discussion focuses on whether these prior regional conditions continue to influence the micro-scale pollen diffusion or whether they are themselves modified by the characteristics of the surface. If this were to be the case, then it would be essential to address the issue of how it affects the pollen concentrations at the pedestrian level, with all this may imply in term of public health.

  10. New insights into ragweed pollen allergens.

    PubMed

    Bordas-Le Floch, Véronique; Groeme, Rachel; Chabre, Henri; Baron-Bodo, Véronique; Nony, Emmanuel; Mascarell, Laurent; Moingeon, Philippe

    2015-11-01

    Pollen allergens from short ragweed (Ambrosia artemisiifolia) cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies (IUIS) allergen database. With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies. This review provides an update on both known as well as novel candidate allergens from short ragweed pollen, identified through a comprehensive characterization of the ragweed pollen transcriptome and proteome. PMID:26383916

  11. Pollen dispersal by Artemisia tridentata (Asteraceae)

    NASA Astrophysics Data System (ADS)

    Laursen, S. C.; Reiners, W. A.; Kelly, R. D.; Gerow, K. G.

    2007-08-01

    While the biophysics of anemophilous pollen dispersal is understood in principle, empirical studies for testing such principles are rare, particularly in native ecosystems. This paper describes mechanisms underlying the dispersal of Artemisia pollen in a Wyoming sagebrush steppe. The relationships between meteorological variables and pollen flux were defined during the 1999 Artemisia flowering season, and detailed processes at the individual plant level were experimentally tested in the field in 2000. Results indicated that Artemisia pollen presentation is continuous but with early morning maxima. Atmospheric pollen concentrations and potential dispersal rates are controlled at diurnal time scales by individual flower development together with characteristic changes in temperature/humidity and wind speeds, at multi-day scales by frontal weather patterns, and at week-long scales by flowering phenology.

  12. Importance of Saprotrophic Freshwater Fungi for Pollen Degradation

    PubMed Central

    Wurzbacher, Christian; Rösel, Stefan; Rychła, Anna; Grossart, Hans-Peter

    2014-01-01

    Fungi and bacteria are the major organic matter (OM) decomposers in aquatic ecosystems. While bacteria are regarded as primary mineralizers in the pelagic zone of lakes and oceans, fungi dominate OM decomposition in streams and wetlands. Recent findings indicate that fungal communities are also active in lakes, but little is known about their diversity and interactions with bacteria. Therefore, the decomposer niche overlap of saprotrophic fungi and bacteria was studied on pollen (as a seasonally recurring source of fine particulate OM) by performing microcosm experiments with three different lake types. Special emphasis was placed on analysis of fungal community composition and diversity. We hypothesized that (I) pollen select for small saprotrophic fungi and at the same time for typical particle-associated bacteria; (II) fungal communities form specific free-living and attached sub-communities in each lake type; (III) the ratio between fungi or bacteria on pollen is controlled by the lake's chemistry. Bacteria-to-fungi ratios were determined by quantitative PCR (qPCR), and bacterial and fungal diversity were studied by clone libraries and denaturing gradient gel electrophoresis (DGGE) fingerprints. A protease assay was used to identify functional differences between treatments. For generalization, systematic differences in bacteria-to-fungi ratios were analyzed with a dataset from the nearby Baltic Sea rivers. High abundances of Chytridiomycota as well as occurrences of Cryptomycota and yeast-like fungi confirm the decomposer niche overlap of saprotrophic fungi and bacteria on pollen. As hypothesized, microbial communities consistently differed between the lake types and exhibited functional differences. Bacteria-to-fungi ratios correlated well with parameters such as organic carbon and pH. The importance of dissolved organic carbon and nitrogen for bacteria-to-fungi ratios was supported by the Baltic Sea river dataset. Our findings highlight the fact that carbon

  13. Pollen grains for oral vaccination

    PubMed Central

    Atwe, Shashwati U.; Ma, Yunzhe; Gill, Harvinder Singh

    2015-01-01

    Oral vaccination can offer a painless and convenient method of vaccination. Furthermore, in addition to systemic immunity it has potential to stimulate mucosal immunity through antigen-processing by the gut-associated lymphoid tissues. In this study we propose the concept that pollen grains can be engineered for use as a simple modular system for oral vaccination. We demonstrate feasibility of this concept by using spores of Lycopodium clavatum (clubmoss) (LSs). We show that LSs can be chemically cleaned to remove native proteins to create intact clean hollow LS shells. Empty pollen shells were successfully filled with molecules of different sizes demonstrating their potential to be broadly applicable as a vaccination system. Using ovalbumin (OVA) as a model antigen, LSs formulated with OVA were orally fed to mice. LSs stimulated significantly higher anti-OVA serum IgG and fecal IgA antibodies compared to those induced by use of cholera toxin as a positive-control adjuvant. The antibody response was not affected by pre-neutralization of the stomach acid, and persisted for up to seven months. Confocal microscopy revealed that LSs can translocate in to mouse intestinal wall. Overall, this study lays the foundation of using LSs as a novel approach for oral vaccination. PMID:25151980

  14. Pollen grains for oral vaccination.

    PubMed

    Atwe, Shashwati U; Ma, Yunzhe; Gill, Harvinder Singh

    2014-11-28

    Oral vaccination can offer a painless and convenient method of vaccination. Furthermore, in addition to systemic immunity it has potential to stimulate mucosal immunity through antigen-processing by the gut-associated lymphoid tissues. In this study we propose the concept that pollen grains can be engineered for use as a simple modular system for oral vaccination. We demonstrate feasibility of this concept by using spores of Lycopodium clavatum (clubmoss) (LSs). We show that LSs can be chemically cleaned to remove native proteins to create intact clean hollow LS shells. Empty pollen shells were successfully filled with molecules of different sizes demonstrating their potential to be broadly applicable as a vaccination system. Using ovalbumin (OVA) as a model antigen, LSs formulated with OVA were orally fed to mice. LSs stimulated significantly higher anti-OVA serum IgG and fecal IgA antibodies compared to those induced by use of cholera toxin as a positive-control adjuvant. The antibody response was not affected by pre-neutralization of the stomach acid, and persisted for up to 7 months. Confocal microscopy revealed that LSs can translocate into mouse intestinal wall. Overall, this study lays the foundation of using LSs as a novel approach for oral vaccination. PMID:25151980

  15. A late Quaternary pollen dataset in eastern continental Asia for plant migration study, vegetation and climate reconstructions: set up and evaluation

    NASA Astrophysics Data System (ADS)

    Cao, Xianyong; Ni, Jian; Herzschuh, Ulrike; Wang, Yongbo; Zhao, Yan

    2013-04-01

    A total of 272 pollen records with reliable dating information and high temporal resolutions were selected from a large collection of both original and digitized pollen spectra from the eastern continental Asia (70°-135°E and 18°-55°N). After pollen percentage recalculations, taxonomy harmonization, and age model revision, pollen spectra were interpolated at a 500-year resolution, a taxonomically harmonized and temporally standardized fossil pollen dataset was established, which has 226 pollen taxa and covers the last 22 cal ka. Of the 227 pollen records, 85% were published during the last two decades with reliable chronologies and high temporal resolutions, and 50% have original data with complete pollen assemblages, all of them ensure the quality of this dataset. The available pollen records at each 500-year time slice are well distributed in all main vegetation types and climatic zones over the study area, making their pollen spectra suitable for palaeovegetation and palaeoclimate research. Such a dataset can be used as an example for the development of similar datasets in other regions of the world.

  16. Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland)

    PubMed Central

    Hochuli, Peter A.; Feist-Burkhardt, Susanne

    2013-01-01

    Here we report on angiosperm-like pollen and Afropollis from the Anisian (Middle Triassic, 247.2–242.0 Ma) of a mid-latitudinal site in Northern Switzerland. Small monosulcate pollen grains with typical reticulate (semitectate) sculpture, columellate structure of the sexine and thin nexine show close similarities to early angiosperm pollen known from the Early Cretaceous. However, they differ in their extremely thin inner layer (nexine). Six different pollen types (I–VI) are differentiated based on size, reticulation pattern, and exine structure. The described pollen grains show all the essential features of angiosperm pollen. However, considering the lack of a continuous record throughout the lower part of the Mesozoic and the comparison with the oldest Cretaceous finds we suggest an affinity to an angiosperm stem group. Together with the previously published records from the Middle Triassic of the Barents Sea area the angiosperm-like pollen grains reflect a considerable diversity of the parent plants during the Middle Triassic. Sedimentological evidence and associated palynofloras also suggest a remarkable ecological range for these plants. Associated with these grains we found pollen comparable to the genus Afropollis. Representatives of this genus are commonly recorded in Lower Cretaceous sediments of low latitudes, but until now had no record from the lower part of the Mesozoic. PMID:24106492

  17. Pollen analysis of honey and pollen collected by Apis mellifera linnaeus, 1758 (Hymenoptera, Apidae), in a mixed environment of Eucalyptus plantation and native cerrado in Southeastern Brazil.

    PubMed

    Simeão, C M G; Silveira, F A; Sampaio, I B M; Bastos, E M A F

    2015-11-01

    Eucalyptus plantations are frequently used for the establishment of bee yards. This study was carried on at Fazenda Brejão, northwestern region of the State of Minas Gerais, Brazil. This farm is covered both with native Cerrado vegetation (Brazilian savanna) and eucalyptus plantations. This paper reports on the botanic origin of pollen pellets and honey collected from honeybee (Apis mellifera) hives along a thirteen-month period (January 2004 to January 2005). The most frequent pollen types found in the pollen pellets during the rainy season were Trema micrantha (Ulmaceae), Copaifera langsdorffii (Fabaceae), an unidentified Poaceae, unidentified Asteraceae-2, Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae); during the dry season the most frequent pollen types were Acosmium dasycarpum (Fabaceae), Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae). Pollen grains of Baccharis sp. (Asteraceae), Cecropia sp. 1 (Cecropiaceae), Copaifera langsdorffii (Fabaceae), Mimosa nuda (Fabaceae), Eucalyptus spp. (Myrtaceae) and Trema micrantha (Ulmaceae) were present in the honey samples throughout the study period. PMID:26628236

  18. Pollen

    MedlinePlus

    ... most common grasses that can cause allergies are: Bermuda grass Johnson grass Kentucky bluegrass Orchard grass Sweet ... Health Sciences 111 T.W. Alexander Drive Research Triangle Park, N.C. 27709 Last Reviewed: July 14, ...

  19. Quantifying Aerial Concentrations of Maize Pollen in the Atmospheric Surface Layer Using Remote-Piloted Airplanes and Lagrangian Stochastic Modeling

    NASA Astrophysics Data System (ADS)

    Aylor, Donald E.; Boehm, Matthew T.; Shields, Elson J.

    2006-07-01

    The extensive adoption of genetically modified crops has led to a need to understand better the dispersal of pollen in the atmosphere because of the potential for unwanted movement of genetic traits via pollen flow in the environment. The aerial dispersal of maize pollen was studied by comparing the results of a Lagrangian stochastic (LS) model with pollen concentration measurements made over cornfields using a combination of tower-based rotorod samplers and airborne radio-controlled remote-piloted vehicles (RPVs) outfitted with remotely operated pollen samplers. The comparison between model and measurements was conducted in two steps. In the first step, the LS model was used in combination with the rotorod samplers to estimate the pollen release rate Q for each sampling period. In the second step, a modeled value for the concentration Cmodel, corresponding to each RPV measured value Cmeasure, was calculated by simulating the RPV flight path through the LS model pollen plume corresponding to the atmospheric conditions, field geometry, wind direction, and source strength. The geometric mean and geometric standard deviation of the ratio Cmodel/Cmeasure over all of the sampling periods, except those determined to be upwind of the field, were 1.42 and 4.53, respectively, and the lognormal distribution corresponding to these values was found to fit closely the PDF of Cmodel/Cmeasure. Model output was sensitive to the turbulence parameters, with a factor-of-100 difference in the average value of Cmodel over the range of values encountered during the experiment. In comparison with this large potential variability, it is concluded that the average factor of 1.4 between Cmodel and Cmeasure found here indicates that the LS model is capable of accurately predicting, on average, concentrations over a range of atmospheric conditions.

  20. Heterotrimeric G-protein participation in Arabidopsis pollen germination through modulation of a plasmamembrane hyperpolarization-activated Ca2+-permeable channel.

    PubMed

    Wu, Yansheng; Xu, Xiaodong; Li, Sujuan; Liu, Ting; Ma, Ligeng; Shang, Zhonglin

    2007-01-01

    The role of heterotrimeric G proteins in pollen germination and tube growth was investigated using Arabidopsis thaliana plants in which the gene (GPA) encoding the G-protein a subunit (Galpha) was null or overexpressed. Pollen germination, free cytosolic calcium concentration ([Ca(2+)](cyt)) and Ca(2+) channel activity in the plasma membrane (PM) of pollen cells were investigated. Results showed that, compared with pollen grains of the wild type (ecotype Wassilewskija, ws), in vitro germinated pollen of Galpha null mutants (gpa1-1 and gpa1-2) had lower germination percentages and shorter pollen tubes, while pollen from Galpha overexpression lines (wGalpha and cGalpha) had higher germination percentages and longer pollen tubes. Compared with ws pollen cells, [Ca(2+)](cyt) was lower in gpa1-1 and gpa1-2 and higher in wGalpha and cGalpha. In whole-cell patch clamp recordings, a hyperpolarization-activated Ca(2+)-permeable conductance was identified in the PM of pollen protoplasts. The conductance was suppressed by trivalent cations but insensitive to organic blockers; its permeability to divalent cations was Ba(2+) > Ca(2+) > Mg(2+) > Sr(2+) > Mn(2+). The activity of the Ca(2+)-permeable channel conductance was down-regulated in pollen protoplasts of gpa1-1 and gpa1-2, and up-regulated in wGalpha and cGalpha. The results suggest that Galpha may participate in pollen germination through modulation of the hyperpolarization-activated Ca(2+) channel in the PM of pollen cells. PMID:17953540

  1. Isolation of total RNA from pollens.

    PubMed

    Bijli, K M; Singh, B P; Sridhara, S; Arora, N

    2001-05-01

    Isolation of total RNA from plant materials has been difficult, due to the presence of complex organic substances and the associated pigmentation. In fact, there is a dearth of standardized protocols for isolating total RNA from pollens. To find a simple and reliable method for isolating total RNA from pollen, four methods, viz. phenol/SDS (PS), guanidine HCl (GH), tri-reagent (TR), and modified SDS-betaME (SB) were tested with fresh pollen of Ricinus communis (procured at -70 degrees C) and pollen dried at 30-37 degrees C. The quality and quantity of RNA was superior for the material processed at -70 degrees C. SB gave the highest RNA yield (2.35 mg/g, OD260/280 >2.0), compared to other methods. The results obtained by the SB method were found to be comparable with the widely used tri-reagent method. This was validated with other pollens of Imperata cylindrica and Xanthium strumarium. The yield obtained from graded amounts of pollen was consistent with SB, compared to the TR method. The RNA isolated by SB gave good quality mRNA for synthesizing cDNA. The SDS-betaME method is simple, efficient, and uses less expensive reagents. Hence, we recommend the modified SDS-betaME method for isolating total RNA from pollens. PMID:11426703

  2. Thunderstorm-asthma and pollen allergy.

    PubMed

    D'Amato, G; Liccardi, G; Frenguelli, G

    2007-01-01

    Thunderstorms have been linked to asthma epidemics, especially during the pollen seasons, and there are descriptions of asthma outbreaks associated with thunderstorms, which occurred in several cities, prevalently in Europe (Birmingham and London in the UK and Napoli in Italy) and Australia (Melbourne and Wagga Wagga). Pollen grains can be carried by thunderstorm at ground level, where pollen rupture would be increased with release of allergenic biological aerosols of paucimicronic size, derived from the cytoplasm and which can penetrate deep into lower airways. In other words, there is evidence that under wet conditions or during thunderstorms, pollen grains may, after rupture by osmotic shock, release into the atmosphere part of their content, including respirable, allergen-carrying cytoplasmic starch granules (0.5-2.5 microm) or other paucimicronic components that can reach lower airways inducing asthma reactions in pollinosis patients. The thunderstorm-asthma outbreaks are characterized, at the beginning of thunderstorms by a rapid increase of visits for asthma in general practitioner or hospital emergency departments. Subjects without asthma symptoms, but affected by seasonal rhinitis can experience an asthma attack. No unusual levels of air pollution were noted at the time of the epidemics, but there was a strong association with high atmospheric concentrations of pollen grains such as grasses or other allergenic plant species. However, subjects affected by pollen allergy should be informed about a possible risk of asthma attack at the beginning of a thunderstorm during pollen season. PMID:17156336

  3. Genomic Conflicts that Cause Pollen Mortality and Raise Reproductive Barriers in Arabidopsis thaliana.

    PubMed

    Simon, Matthieu; Durand, Stéphanie; Pluta, Natacha; Gobron, Nicolas; Botran, Lucy; Ricou, Anthony; Camilleri, Christine; Budar, Françoise

    2016-07-01

    Species differentiation and the underlying genetics of reproductive isolation are central topics in evolutionary biology. Hybrid sterility is one kind of reproductive barrier that can lead to differentiation between species. Here, we analyze the complex genetic basis of the intraspecific hybrid male sterility that occurs in the offspring of two distant natural strains of Arabidopsis thaliana, Shahdara and Mr-0, with Shahdara as the female parent. Using both classical and quantitative genetic approaches as well as cytological observation of pollen viability, we demonstrate that this particular hybrid sterility results from two causes of pollen mortality. First, the Shahdara cytoplasm induces gametophytic cytoplasmic male sterility (CMS) controlled by several nuclear loci. Second, several segregation distorters leading to allele-specific pollen abortion (pollen killers) operate in hybrids with either cytoplasm. The complete sterility of the hybrid with the Shahdara cytoplasm results from the genetic linkage of the two causes of pollen mortality, i.e., CMS nuclear determinants and pollen killers. Furthermore, natural variation at these loci in A. thaliana is associated with different male-sterility phenotypes in intraspecific hybrids. Our results suggest that the genomic conflicts that underlie segregation distorters and CMS can concurrently lead to reproductive barriers between distant strains within a species. This study provides a new framework for identifying molecular mechanisms and the evolutionary history of loci that contribute to reproductive isolation, and possibly to speciation. It also suggests that two types of genomic conflicts, CMS and segregation distorters, may coevolve in natural populations. PMID:27182945

  4. Calorimetric Properties of Dehydrating Pollen (Analysis of a Desiccation-Tolerant and an Intolerant Species).

    PubMed Central

    Buitink, J.; Walters-Vertucci, C.; Hoekstra, F. A.; Leprince, O.

    1996-01-01

    The physical state of water in the desiccation-tolerant pollen of Typha latifolia L. and the desiccation-sensitive pollen of Zea mays L. was studied using differential scanning calorimetry in an attempt to further unravel the complex mechanisms of desiccation tolerance. Melting transitions of water were not observed at water content (wc) values less than 0.21 (T. latifolia) and 0.26 (Z. mays) g H2O/g dry weight. At moisture levels at which melting transitions were not observable, water properties could be characterized by changes in heat capacity. Three hydration regions could be distinguished with the defining wc values changing as a function of temperature. Shifts in baseline power resembling second-order transitions were observed in both species and were interpreted as glass-to-liquid transitions, the glass-transition temperatures being dependent on wc. Irrespective of the extent of desiccation tolerance, both pollens exhibited similar state diagrams. The viability of maize pollen at room temperature decreased gradually with the removal of the unfrozen water fraction. In maize, viability was completely lost before grains were sufficiently dried to enter into a glassy state. Apparently, the glassy state per se cannot provide desiccation tolerance. From the existing data, we conclude that, although no major differences in the physical behavior of water could be distinguished between desiccation-tolerant and -intolerant pollens, the physiological response to the loss of water varies between the two pollen types. PMID:12226289

  5. Cells of the connective tissue differentiate and migrate into pollen sacs

    NASA Astrophysics Data System (ADS)

    Iqbal, M. C. M.; Wijesekara, Kolitha B.

    2002-01-01

    In angiosperms, archesporial cells in the anther primordium undergo meiosis to form haploid pollen, the sole occupants of anther sacs. Anther sacs are held together by a matrix of parenchyma cells, the connective tissue. Cells of the connective tissue are not known to differentiate. We report the differentiation of parenchyma cells in the connective tissue of two Gordonia species into pollen-like structures (described as pseudopollen), which migrate into the anther sacs before dehiscence. Pollen and pseudopollen were distinguishable by morphology and staining. Pollen were tricolpate to spherical while pseudopollen were less rigid and transparent with a ribbed surface. Both types were different in size, shape, staining and surface architecture. The ratio of the number of pseudopollen to pollen was 1:3. During ontogeny in the connective tissue, neither cell division nor tetrad formation was observed and hence pseudopollen were presumed to be diploid. Only normal pollen germinated on a germination medium. Fixed preparations in time seemed to indicate that pseudopollen migrate from the connective tissue into the anther sac.

  6. An immunoblotting analysis of cross-reactivity between melon, and plantago and grass pollens.

    PubMed

    García Ortiz, J C; Ventas, P; Cosmes, P; López-Asunsolo, A

    1996-01-01

    It is known that most patients with type I allergy to pollens also suffer intolerance to fruits. Recently, an epidemiological and CAP-inhibition study has shown a new clustering of allergy between melon and Plantago and grass pollens. The aim of the present study was to confirm these results by immunoblotting analysis and inhibition of immunoblotting. Sera from 3 patients with confirmed allergy to melon, and Dactylis glomerata and Plantago lanceolata pollens were used for the in vitro studies. SDS-PAGE and immunoblotting analysis with a pool of sera revealed that several distinct protein bands were shared by the three extracts at 14, 31, and a spectrum between 40 and 70 kDa, approximately. Immunoblotting inhibition experiments, performed with extracts of melon, Plantago and Dactylis, showed that all allergens of melon blotting were almost completely inhibited by grass and Plantago pollen extracts. Inversely, the melon extract was capable of inhibiting IgE-binding to various allergens of Dactylis at high mol mass and partially to the band at 14 kDa. Moreover, the melon almost totally inhibited the IgE-binding capacity to the proteins of Plantago extract. Taken together, the results support the presence of structurally similar allergens in melon, Plantago and grass pollens, and that all allergenic epitopes of the melon are present in these pollens. PMID:9015782

  7. Mid- to Late-Wisconsin Pollen Record of San Felipe Basin, Baja California

    NASA Astrophysics Data System (ADS)

    Lozano-García, María. Socorro; Ortega-Guerrero, Beatriz; Sosa-Nájera, Susana

    2002-07-01

    A lacustrine sequence from Laguna Seca San Felipe, Baja California, in the southwestern Sonoran Desert, provides the first record of mid- to late-Wisconsin vegetation in one of the driest regions of North America. Pollen analysis was performed in the intermediate part of the sequence from ca. 44,000 to ca. 13,000 14C yr B.P. according to six 14C radiocarbon dates. Sedimentation of eolian sands prior to 44,000 14C yr B.P. indicates dry conditions. High pollen concentration of montane and chaparral species in the pollen assemblages contrast with the modern desert vegetation. Sixty-four pollen types were identified. The source of mid- to late-Wisconsin sedimentation must have been the plant communities in the surrounding highlands of the basin. Mid-Wisconsin pollen assemblages dominated by pines, junipers, and Artemisia reflect humid conditions in the area. By late Wisconsin time, a significant increment in junipers indicates a lowering in the altitudinal ranges of woodlands/chaparral. Pollen from wind-pollinated species is abundant while desert plants, specifically animal or insect pollinated species, are poorly represented. The San Felipe record does not identify the Last Glacial Maximum as the time of greatest effective moisture, as suggested by pluvial lake levels and other paleoclimatic evidence in the soutwestern United States.

  8. Biochemical and Immunocytological Characterizations of Arabidopsis Pollen Tube Cell Wall1[C][W][OA

    PubMed Central

    Dardelle, Flavien; Lehner, Arnaud; Ramdani, Yasmina; Bardor, Muriel; Lerouge, Patrice; Driouich, Azeddine; Mollet, Jean-Claude

    2010-01-01

    During plant sexual reproduction, pollen germination and tube growth require development under tight spatial and temporal control for the proper delivery of the sperm cells to the ovules. Pollen tubes are fast growing tip-polarized cells able to perceive multiple guiding signals emitted by the female organ. Adhesion of pollen tubes via cell wall molecules may be part of the battery of signals. In order to study these processes, we investigated the cell wall characteristics of in vitro-grown Arabidopsis (Arabidopsis thaliana) pollen tubes using a combination of immunocytochemical and biochemical techniques. Results showed a well-defined localization of cell wall epitopes. Low esterified homogalacturonan epitopes were found mostly in the pollen tube wall back from the tip. Xyloglucan and arabinan from rhamnogalacturonan I epitopes were detected along the entire tube within the two wall layers and the outer wall layer, respectively. In contrast, highly esterified homogalacturonan and arabinogalactan protein epitopes were found associated predominantly with the tip region. Chemical analysis of the pollen tube cell wall revealed an important content of arabinosyl residues (43%) originating mostly from (1→5)-α-l-arabinan, the side chains of rhamnogalacturonan I. Finally, matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of endo-glucanase-sensitive xyloglucan showed mass spectra with two dominant oligosaccharides (XLXG/XXLG and XXFG), both being mono O-acetylated, and accounting for over 68% of the total ion signals. These findings demonstrate that the Arabidopsis pollen tube wall has its own characteristics compared with other cell types in the Arabidopsis sporophyte. These structural features are discussed in terms of pollen tube cell wall biosynthesis and growth dynamics. PMID:20547702

  9. MicroRNA and tasiRNA diversity in mature pollen of Arabidopsis thaliana

    PubMed Central

    2009-01-01

    Background New generation sequencing technology has allowed investigation of the small RNA populations of flowering plants at great depth. However, little is known about small RNAs in their reproductive cells, especially in post-meiotic cells of the gametophyte generation. Pollen - the male gametophyte - is the specialised haploid structure that generates and delivers the sperm cells to the female gametes at fertilisation. Whether development and differentiation of the male gametophyte depends on the action of microRNAs and trans-acting siRNAs guiding changes in gene expression is largely unknown. Here we have used 454 sequencing to survey the various small RNA populations present in mature pollen of Arabidopsis thaliana. Results In this study we detected the presence of 33 different microRNA families in mature pollen and validated the expression levels of 17 selected miRNAs by Q-RT-PCR. The majority of the selected miRNAs showed pollen-enriched expression compared with leaves. Furthermore, we report for the first time the presence of trans-acting siRNAs in pollen. In addition to describing new patterns of expression for known small RNAs in each of these classes, we identified 7 putative novel microRNAs. One of these, ath-MIR2939, targets a pollen-specific F-box transcript and we demonstrate cleavage of its target mRNA in mature pollen. Conclusions Despite the apparent simplicity of the male gametophyte, comprising just two different cell types, pollen not only utilises many miRNAs and trans-acting siRNAs expressed in the somatic tissues but also expresses novel miRNAs. PMID:20042113

  10. Pollen and Phytolith Evidence for Rice Cultivation and Vegetation Change during the Mid-Late Holocene at the Jiangli Site, Suzhou, East China

    PubMed Central

    Qiu, Zhenwei; Jiang, Hongen; Ding, Jinlong; Hu, Yaowu; Shang, Xue

    2014-01-01

    Pollen and phytolith analyses were undertaken at the Jiangli site in Suzhou, Jiangsu Province, combined with studies on macrofossils by flotation. The concentration of pollen decreased while the percentage of Poaceae pollen in the profile increased from the late phase of the Majiabang Culture to the Songze Culture suggesting that human impact on the local environment intensified gradually. The discovery of rice paddy implies a relatively advanced rice cultivation in this area during the middle-late Holocene. Other than phytoliths, the high percentage of Oryza-type Poaceae pollen (larger than 40 µm) supplied robust evidence for the existence of rice paddy. Moreover, the fact that the farther from the rice paddy, the lower the concentration and percentage of Poaceae pollen also proves that the dispersal and deposition of pollen is inversely proportional to the distance. PMID:24466254

  11. Trends in prevalence of allergic rhinitis and correlation with pollen counts in Switzerland

    NASA Astrophysics Data System (ADS)

    Frei, Thomas; Gassner, Ewald

    2008-11-01

    but with a slight tendency to decrease. In Locarno, most of the pollen species also show a decreasing trend, while in Zurich, the development is somewhat different as the pollen counts of most of the pollen types have been increasing. It is interesting, however, that some of the pollen counts of this station (grass, stinging nettle, mugwort and ragweed) have been decreasing in the period 1982-2007.

  12. Evaluation of structural and geological factors in orogenic gold type mineralisation in the Kervian area, north-west Iran, using airborne geophysical data

    NASA Astrophysics Data System (ADS)

    Almasi, Alireza; Jafarirad, Alireza; Kheyrollahi, Hasan; Rahimi, Mana; Afzal, Peyman

    2014-03-01

    The Piranshahr-Sardasht-Saqqez Zone (PSSZ) in the north-west of the Sanandaj-Sirjan metamorphic zone (SSZ) hosts some major Iranian gold deposits. In the south-east of PSSZ, there is a north-east trending orogenic gold belt which contains three gold deposits/occurrences (Qolqoleh, Kervian and Ghabaghloujeh). In this research, studies are focused on processing and analysing airborne magnetic and radiometric data in order to find applicable indicators for prospecting gold in this area. Former studies on the gold deposits/occurrences in the study area suggest three essential factors in local orogenic gold mineralisation: (1) intersecting deep bending structures/shear zones, (2) Fe-rich mafic meta-volcanic lithologies (primary source and host rocks) and (3) altered mylonitic granites (secondary host rock). Geological structures and lithological contacts can be mapped based on locating edges in the magnetic field at different depths. In this study, we extracted the structure from aeromagnetic data by reduction to the pole, upward continuation and applying a tilt derivative filter to the horizontal derivative of the upward continued data. Upward continuation was to several levels from 500 to 4000 m. Afterwards, a 3D architecture was built based on extracted subsurface lineaments in different levels. This 3D model can assist in the visualisation of the underground shape of structures that may influence gold mineralisation. Moreover, mafic meta-volcanic rocks in the study area, which contain magnetic minerals such as magnetite, titanomagnetite and ilmenite, can be mapped using aeromagnetic data. Mylonitic granites, which are the other host rock in the deposits, were mapped using airborne radiometric data.

  13. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  14. Bee Pollen: Chemical Composition and Therapeutic Application

    PubMed Central

    Komosinska-Vassev, Katarzyna; Olczyk, Pawel; Kaźmierczak, Justyna; Olczyk, Krystyna

    2015-01-01

    Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process. PMID:25861358

  15. Intracellular auxin transport in pollen

    PubMed Central

    Dal Bosco, Cristina; Dovzhenko, Alexander; Palme, Klaus

    2012-01-01

    Cellular auxin homeostasis is controlled at many levels that include auxin biosynthesis, auxin metabolism, and auxin transport. In addition to intercellular auxin transport, auxin homeostasis is modulated by auxin flow through the endoplasmic reticulum (ER). PIN5, a member of the auxin efflux facilitators PIN protein family, was the first protein to be characterized as an intracellular auxin transporter. We demonstrated that PIN8, the closest member of the PIN family to PIN5, represents another ER-residing auxin transporter. PIN8 is specifically expressed in the male gametophyte and is located in the ER. By combining genetic, physiological, cellular and biochemical data we demonstrated a role for PIN8 in intracellular auxin homeostasis. Although our investigation shed light on intracellular auxin transport in pollen, the physiological function of PIN8 still remains to be elucidated. Here we discuss our data taking in consideration other recent findings. PMID:22990451

  16. Use Of MODIS Satellite Images And An Atmospheric Dust Transport Model To Evaluate Juniperus Spp. Pollen Phenology And Transport

    NASA Astrophysics Data System (ADS)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A. R.; Nickovic, S.; Crimmins, T. M.; Van De Water, P. K.; Pejanovic, G.; Vukovic, A. J.; Myers, O.; Budge, A.; Zelicoff, A.; Bunderson, L.; Ponce-Campos, G.

    2011-12-01

    Pollen can be transported great distances. Van de Water et al., 2003 reported Juniperus spp. pollen, a significant aeroallergen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. Direct detection of pollen via satellite is not practical. A practical alternative combines modeling and phenological observations using ground based sampling and satellite data. The DREAM (Dust REgional Atmospheric Model) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and quantities of dust (Nickovic et al. 2001). The use of satellite data products for studying phenology is well documented (White and Nemani 2006). In the current project MODIS data will provide critical input to the PREAM model providing pollen source location, timing of pollen release, and vegetation type. We are modifying the DREAM model (PREAM - Pollen REgional Atmospheric Model) to incorporate pollen transport. The linkages already exist with DREAM through PHAiRS (Public Health Applications in Remote Sensing) to the public health community. This linkage has the potential to fill this data gap so that the potential association of health effects of pollen can better be tracked for possible linkage with health outcome data which may be associated with asthma, respiratory effects, myocardial infarction, and lost workdays. Juniperus spp. pollen phenology may respond to a wide range of environmental factors such as day length, growing degree-days, precipitation patterns and soil moisture. Species differences are also important. These environmental factors vary over both time and spatial scales. Ground based networks such as the USA National Phenology Network have been established to provide national wide observations of vegetation phenology. However, the density of observers is not adequate to sufficiently document the phenology variability

  17. Use of MODIS Satellite Images and an Atmospheric Dust Transport Model to Evaluate Juniperus spp. Pollen Phenology and Transport

    NASA Technical Reports Server (NTRS)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A.; Nickovic, S.; Pejanovic, G. A.; Vukovic, A.; Van de Water, P. K.; Myers, O. B.; Budge, A. M.; Zelicoff, A. P.; Bunderson, L.; Ponce-Campos, G.; Crimmins, T. M.

    2011-01-01

    Pollen can be transported great distances. Van de Water et al., 2003 reported Juniperus spp. pollen, a significant aeroallergen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. Direct detection of pollen via satellite is not practical. A practical alternative combines modeling and phenological observations using ground based sampling and satellite data. The DREAM (Dust REgional Atmospheric Model) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and quantities of dust (Nickovic et al. 2001). The use of satellite data products for studying phenology is well documented (White and Nemani 2006). In the current project MODIS data will provide critical input to the PREAM model providing pollen source location, timing of pollen release, and vegetation type. We are modifying the DREAM model (PREAM - Pollen REgional Atmospheric Model) to incorporate pollen transport. The linkages already exist with DREAM through PHAiRS (Public Health Applications in Remote Sensing) to the public health community. This linkage has the potential to fill this data gap so that the potential association of health effects of pollen can better be tracked for possible linkage with health outcome data which may be associated with asthma, respiratory effects, myocardial infarction, and lost workdays. Juniperus spp. pollen phenology may respond to a wide range of environmental factors such as day length, growing degree-days, precipitation patterns and soil moisture. Species differences are also important. These environmental factors vary over both time and spatial scales. Ground based networks such as the USA National Phenology Network have been established to provide national wide observations of vegetation phenology. However, the density of observers is not adequate to sufficiently document the phenology variability

  18. Capturing the Surface Texture and Shape of Pollen: A Comparison of Microscopy Techniques

    PubMed Central

    Sivaguru, Mayandi; Mander, Luke; Fried, Glenn; Punyasena, Surangi W.

    2012-01-01

    Research on the comparative morphology of pollen grains depends crucially on the application of appropriate microscopy techniques. Information on the performance of microscopy techniques can be used to inform that choice. We compared the ability of several microscopy techniques to provide information on the shape and surface texture of three pollen types with differing morphologies. These techniques are: widefield, apotome, confocal and two-photon microscopy (reflected light techniques), and brightfield and differential interference contrast microscopy (DIC) (transmitted light techniques). We also provide a first view of pollen using super-resolution microscopy. The three pollen types used to contrast the performance of each technique are: Croton hirtus (Euphorbiaceae), Mabea occidentalis (Euphorbiaceae) and Agropyron repens (Poaceae). No single microscopy technique provided an adequate picture of both the shape and surface texture of any of the three pollen types investigated here. The wavelength of incident light, photon-collection ability of the optical technique, signal-to-noise ratio, and the thickness and light absorption characteristics of the exine profoundly affect the recovery of morphological information by a given optical microscopy technique. Reflected light techniques, particularly confocal and two-photon microscopy, best capture pollen shape but provide limited information on very fine surface texture. In contrast, transmitted light techniques, particularly differential interference contrast microscopy, can resolve very fine surface texture but provide limited information on shape. Texture comprising sculptural elements that are spaced near the diffraction limit of light (∼250 nm; NDL) presents an acute challenge to optical microscopy. Super-resolution structured illumination microscopy provides data on the NDL texture of A. repens that is more comparable to textural data from scanning electron microscopy than any other optical microscopy technique

  19. A Pollen-Specific RALF from Tomato That Regulates Pollen Tube Elongation12[W][OA

    PubMed Central

    Covey, Paul A.; Subbaiah, Chalivendra C.; Parsons, Ronald L.; Pearce, Gregory; Lay, Fung T.; Anderson, Marilyn A.; Ryan, Clarence A.; Bedinger, Patricia A.

    2010-01-01

    Rapid Alkalinization Factors (RALFs) are plant peptides that rapidly increase the pH of plant suspension cell culture medium and inhibit root growth. A pollen-specific tomato (Solanum lycopersicum) RALF (SlPRALF) has been identified. The SlPRALF gene encodes a preproprotein that appears to be processed and released from the pollen tube as an active peptide. A synthetic SlPRALF peptide based on the putative active peptide did not affect pollen hydration or viability but inhibited the elongation of normal pollen tubes in an in vitro growth system. Inhibitory effects of SlPRALF were detectable at concentrations as low as 10 nm, and complete inhibition was observed at 1 μm peptide. At least 10-fold higher levels of alkSlPRALF, which lacks disulfide bonds, were required to see similar effects. A greater effect of peptide was observed in low-pH-buffered medium. Inhibition of pollen tube elongation was reversible if peptide was removed within 15 min of exposure. Addition of 100 nm SlPRALF to actively growing pollen tubes inhibited further elongation until tubes were 40 to 60 μm in length, after which pollen tubes became resistant to the peptide. The onset of resistance correlated with the timing of the exit of the male germ unit from the pollen grain into the tube. Thus, exogenous SlPRALF acts as a negative regulator of pollen tube elongation within a specific developmental window. PMID:20388667

  20. Phosphoproteomics Profiling of Tobacco Mature Pollen and Pollen Activated in vitro.

    PubMed

    Fíla, Jan; Radau, Sonja; Matros, Andrea; Hartmann, Anja; Scholz, Uwe; Feciková, Jana; Mock, Hans-Peter; Čapková, Věra; Zahedi, René Peiman; Honys, David

    2016-04-01

    Tobacco mature pollen has extremely desiccated cytoplasm, and is metabolically quiescent. Upon re-hydration it becomes metabolically active and that results in later emergence of rapidly growing pollen tube. These changes in cytoplasm hydration and metabolic activity are accompanied by protein phosphorylation. In this study, we subjected mature pollen, 5-min-activated pollen, and 30-min-activated pollen to TCA/acetone protein extraction, trypsin digestion and phosphopeptide enrichment by titanium dioxide. The enriched fraction was subjected to nLC-MS/MS. We identified 471 phosphopeptides that carried 432 phosphorylation sites, position of which was exactly matched by mass spectrometry. These 471 phosphopeptides were assigned to 301 phosphoproteins, because some proteins carried more phosphorylation sites. Of the 13 functional groups, the majority of proteins were put into these categories: transcription, protein synthesis, protein destination and storage, and signal transduction. Many proteins were of unknown function, reflecting the fact that male gametophyte contains many specific proteins that have not been fully functionally annotated. The quantitative data highlighted the dynamics of protein phosphorylation during pollen activation; the identified phosphopeptides were divided into seven groups based on the regulatory trends. The major group comprised mature pollen-specific phosphopeptides that were dephosphorylated during pollen activation. Several phosphopeptides representing the same phosphoprotein had different regulation, which pinpointed the complexity of protein phosphorylation and its clear functional context. Collectively, we showed the first phosphoproteomics data on activated pollen where the position of phosphorylation sites was clearly demonstrated and regulatory kinetics was resolved. PMID:26792808

  1. Pollen, Tapetum and Orbicule Development in Modiolastrum malvifolium (Malvaceae)

    PubMed Central

    Galati, Beatriz G.; Monacci, Federico; Gotelli, Marina M.; Rosenfeldt, Sonia

    2007-01-01

    Background and Aims Although orbicular functions are still a matter of debate, they are considered by most authors to be exclusively formed by a secretory tapetum. However, the presence of orbicules on a peritapetal membrane associated with a plasmodial tapetum has been described for Abutilon pictum (Malvaceae) in a previous study. Thus, studies on other species of Malvaceae are necessary to corroborate the presence of such bodies in other members of the family. Pollen and microsporangium development of Modiolastrum malvifolium has been studied in this work. Methods Anthers at different stages of development were processed for transmission electron microscopy and light microscopy. Membranes and pollen walls resistant to acetolysis were isolated from whole anthers. Key Results Microspore tetrads have a tetrahedral arrangement. Pollen grains are shed at the bicellular stage. The tapetum is invasive, non-syncytial and a peritapetal membrane with orbicules is formed. Conclusions This is the first report of the presence of orbicules on a peritapetal membrane in a species with a tapetum of an invasive, non-syncytial type. Taking into consideration all the information on the subject, it can be concluded that the presence of orbicules is not a stable criterion to differentiate between a secretory or plasmodial, or intermediate invasive, non-syncytial tapetum. PMID:17353203

  2. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic–Jurassic transition

    PubMed Central

    Kürschner, Wolfram M.; Batenburg, Sietske J.; Mander, Luke

    2013-01-01

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic–Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis. PMID:23926159

  3. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic-Jurassic transition.

    PubMed

    Kürschner, Wolfram M; Batenburg, Sietske J; Mander, Luke

    2013-10-01

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic-Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis. PMID:23926159

  4. Cell wall components and pectin esterification levels as markers of proliferation and differentiation events during pollen development and pollen embryogenesis in Capsicum annuum L.

    PubMed Central

    Bárány, Ivett; Fadón, Begoña; Risueño, María C.; Testillano, Pilar S.

    2010-01-01

    Plant cell walls and their polymers are regulated during plant development, but the specific roles of their molecular components are still unclear, as well as the functional meaning of wall changes in different cell types and processes. In this work the in situ analysis of the distribution of different cell wall components was performed during two developmental programmes, gametophytic pollen development, which is a differentiation process, and stress-induced pollen embryogenesis, which involves proliferation followed by differentiation processes. The changes in cell wall polymers were compared with a system of plant cell proliferation and differentiation, the root apical meristem. The analysis was also carried out during the first stages of zygotic embryogenesis. Specific antibodies recognizing the major cell wall polymers, xyloglucan (XG) and the rhamnogalacturonan II (RGII) pectin domain, and antibodies against high- and low-methyl-esterified pectins were used for both dot-blot and immunolocalization with light and electron microscopy. The results showed differences in the distribution pattern of these molecular complexes, as well as in the proportion of esterified and non-esterified pectins in the two pollen developmental pathways. Highly esterified pectins were characteristics of proliferation, whereas high levels of the non-esterified pectins, XG and RGII were abundant in walls of differentiating cells. Distribution patterns similar to those of pollen embryos were found in zygotic embryos. The wall changes reported are characteristic of proliferation and differentiation events as markers of these processes that take place during pollen development and embryogenesis. PMID:20097842

  5. Toolsets for Airborne Data

    Atmospheric Science Data Center

    2015-04-02

    article title:  Toolsets for Airborne Data     View larger image The ... limit of detection values. Prior to accessing the TAD Web Application ( https://tad.larc.nasa.gov ) for the first time, users must ...

  6. The airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven; Schall, Harold; Shattuck, Paul

    2007-05-01

    The Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the current program status.

  7. Molecular biomarkers for grass pollen immunotherapy

    PubMed Central

    Popescu, Florin-Dan

    2014-01-01

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines. PMID:25237628

  8. Quarternary Pollen Analysis in Secondary School Ecology

    ERIC Educational Resources Information Center

    Slater, F. M.

    1972-01-01

    Describes techniques for studying historic changes in climate by analysis of pollen preserved in peat bogs. Illustrates the methodology and data analysis techniques by reference to results from English research. (AL)

  9. Enclosed bark as a pollen trap

    USGS Publications Warehouse

    Adam, D.P.; Ferguson, C.W.; Lamarch, V.C., Jr.

    1967-01-01

    Counts were made of pollen in traps formed by enclosed bark in two remnants of bristlecone pine, Pinus aristata Engelm., from the White Mountains of east-central California. The traps, dated by tree-rings at A.D. 350 and 1300 B.C., contained a major complex of pine-sagebrush pollen and traces of other species, representing the equivalent of the present vegetation.

  10. Juniper Pollen Hotspots in the Southwest

    NASA Technical Reports Server (NTRS)

    Bunderson, L. D.; VandeWater, P.; Luvall, J.; Levetin, E.

    2013-01-01

    Rationale: Juniperus pollen is a major allergen in Texas, Oklahoma, and New Mexico. While the bulk of pollen may be released in rural areas, large amounts of pollen can be transported to urban areas. Major juniper species in the region include: Juniperus ashei, J. virginiana, J. pinchotii, and J. monosperma. Pollen release is virtually continuous beginning in late September with J. pinchotii and ending in May with J. monosperma. Urban areas in the region were evaluated for the potential of overlapping seasons in order to inform sensitive individuals. Methods: Burkard volumetric pollen traps were established for two consecutive spring seasons at 6 sites in northern New Mexico and 6 sites for two consecutive winter and fall seasons in Texas and Oklahoma Standard methods were used in the preparation and analysis of slides. Results: The Dallas-Fort Worth Metroplex is home to over 6 million people. It is adjacent to populations of J. pinchotii, J. virginiana, and J. ashei. Peak concentration near Dallas for J. ashei in 2011 was 5891 pollen grains/m3 in January 7th. The peak date for J. pinchotii at an upwind sampling location in San Marcos, TX was November 1, 2010 and peak for J. virginiana at a nearby station in Tulsa, OK was November 1, 2010 and peak for J. virginiana at a nearby station in Tulsa, OK was February 20, 2011. Amarillo, TX is adjacent to J. pinchotii, J. ashei, and J. monosperma populations and may be subject to juniper pollen from September through May. Conclusions: Considering the overlapping distributions of juniper trees and the overlapping temporal release of pollen, sensitive patients may benefit from avoiding hotspots.

  11. Molecular Evolution of Hypoallergenic Hybrid Proteins for Vaccination against Grass Pollen Allergy

    PubMed Central

    Linhart, Birgit; Focke-Tejkl, Margarete; Weber, Milena; Narayanan, Meena; Neubauer, Angela; Mayrhofer, Hannes; Blatt, Katharina; Lupinek, Christian; Valent, Peter

    2015-01-01

    More than 10% of the population in Europe and North America suffer from IgE-associated allergy to grass pollen. In this article, we describe the development of a vaccine for grass pollen allergen-specific immunotherapy based on two recombinant hypoallergenic mosaic molecules, designated P and Q, which were constructed out of elements derived from the four major timothy grass pollen allergens: Phl p 1, Phl p 2, Phl p 5, and Phl p 6. Seventeen recombinant mosaic molecules were expressed and purified in Escherichia coli using synthetic genes, characterized regarding biochemical properties, structural fold, and IgE reactivity. We found that depending on the arrangement of allergen fragments, mosaic molecules with strongly varying IgE reactivity were obtained. Based on an extensive screening with sera and basophils from allergic patients, two hypoallergenic mosaic molecules, P and Q, incorporating the primary sequence elements of the four grass pollen allergens were identified. As shown by lymphoproliferation experiments, they contained allergen-specific T cell epitopes required for tolerance induction, and upon immunization of animals induced higher allergen-specific IgG Abs than the wild-type allergens and a registered monophosphoryl lipid A–adjuvanted vaccine based on natural grass pollen allergen extract. Moreover, IgG Abs induced by immunization with P and Q inhibited the binding of patients’ IgE to natural allergens from five grasses better than IgG induced with the wild-type allergens or an extract-based vaccine. Our results suggest that vaccines based on the hypoallergenic grass pollen mosaics can be used for immunotherapy of grass pollen allergy. PMID:25786690

  12. Molecular evolution of hypoallergenic hybrid proteins for vaccination against grass pollen allergy.

    PubMed

    Linhart, Birgit; Focke-Tejkl, Margarete; Weber, Milena; Narayanan, Meena; Neubauer, Angela; Mayrhofer, Hannes; Blatt, Katharina; Lupinek, Christian; Valent, Peter; Valenta, Rudolf

    2015-04-15

    More than 10% of the population in Europe and North America suffer from IgE-associated allergy to grass pollen. In this article, we describe the development of a vaccine for grass pollen allergen-specific immunotherapy based on two recombinant hypoallergenic mosaic molecules, designated P and Q, which were constructed out of elements derived from the four major timothy grass pollen allergens: Phl p 1, Phl p 2, Phl p 5, and Phl p 6. Seventeen recombinant mosaic molecules were expressed and purified in Escherichia coli using synthetic genes, characterized regarding biochemical properties, structural fold, and IgE reactivity. We found that depending on the arrangement of allergen fragments, mosaic molecules with strongly varying IgE reactivity were obtained. Based on an extensive screening with sera and basophils from allergic patients, two hypoallergenic mosaic molecules, P and Q, incorporating the primary sequence elements of the four grass pollen allergens were identified. As shown by lymphoproliferation experiments, they contained allergen-specific T cell epitopes required for tolerance induction, and upon immunization of animals induced higher allergen-specific IgG Abs than the wild-type allergens and a registered monophosphoryl lipid A-adjuvanted vaccine based on natural grass pollen allergen extract. Moreover, IgG Abs induced by immunization with P and Q inhibited the binding of patients' IgE to natural allergens from five grasses better than IgG induced with the wild-type allergens or an extract-based vaccine. Our results suggest that vaccines based on the hypoallergenic grass pollen mosaics can be used for immunotherapy of grass pollen allergy. PMID:25786690

  13. Pollen as atmospheric cloud condensation nuclei

    NASA Astrophysics Data System (ADS)

    Steiner, Allison L.; Brooks, Sarah D.; Deng, Chunhua; Thornton, Daniel C. O.; Pendleton, Michael W.; Bryant, Vaughn

    2015-05-01

    Anemophilous (wind-dispersed) pollen grains are emitted in large quantities by vegetation in the midlatitudes for reproduction. Pollen grains are coarse particles (5-150 µm) that can rupture when wet to form submicron subpollen particles (SPP) that may have a climatic role. Laboratory CCN experiments of six fresh pollen samples show that SPP activate as CCN at a range of sizes, requiring supersaturations from 0.81 (± 0.07)% for 50 nm particles, 0.26 (± 0.03)% for 100 nm particles, and 0.12 (± 0.00)% for 200 nm particles. Compositional analyses indicate that SPP contain carbohydrates and proteins. The SPP contribution to global CCN is uncertain but could be important depending on pollen concentrations outside the surface layer and the number of SPP generated from a single pollen grain. The production of hygroscopic SPP from pollen represents a novel, biologically driven cloud formation pathway that may influence cloud optical properties and lifetimes, thereby influencing climate.

  14. [Factors affecting the estimation of pollen limitation in Sagittaria trifolia].

    PubMed

    Qin, Dao-feng; Li, Ting; Dai, Can

    2015-12-01

    This study explored whether the degree of pollen limitation was affected by the experimental level (a single flower or inflorescence) and pollen quality (self-pollen or outcross-pollen) of supplemental pollination in Sagittaria trifolia. The results showed that the experimental level caused varying degree of pollen limitation. Compared with the inflorescence level, pollination at the single flower level led to a redistribution of resources among flowers, therefore affecting seed numbers. Pollen quality also played a vital role in the estimation of pollen limitation. Compared with self-pollen, supplemental pollination with outcross-pollen resulted in significantly more seeds and a higher germination rate. This proved that in the research system the reproduction was limited by pollen quality rather than quantity. Our study revealed that both experimental level and pollen quality had effects on the estimation of pollen limitation. It was suggested that in future studies we should evaluate pollen limitation at the inflorescence or whole plant level, and also consider comparing self- and outcross-pollen when applicable. PMID:27112030

  15. Does an 'oversupply' of ovules cause pollen limitation?

    PubMed

    Rosenheim, Jay A; Schreiber, Sebastian J; Williams, Neal M

    2016-04-01

    Lifetime seed production can be constrained by shortfalls of pollen receipt ('pollen limitation'). The ovule oversupply hypothesis states that, in response to unpredictable pollen availability, plants evolve to produce more ovules than they expect to be fertilized, and that this results in pollen limitation of seed production. Here, we present a cartoon model and a model of optimal plant reproductive allocations under stochastic pollen receipt to evaluate the hypothesis that an oversupply of ovules leads to increased pollen limitation. We show that an oversupply of ovules has two opposing influences on pollen limitation of whole-plant seed production. First, ovule oversupply increases the likelihood that pollen receipt limits the number of ovules that can be fertilized ('prezygotic pollen limitation'). Second, ovule oversupply increases the proportion of pollen grains received that are used to fertilize ovules ('pollen use efficiency'). As a result of these opposing influences, ovule oversupply has only a modest effect on the degree to which lifetime seed production is constrained by pollen receipt, producing a small decrease in the incidence of pollen limitation. Ovule oversupply is not the cause of the pollen limitation problem, but rather is part of the evolutionary solution to that problem. PMID:26574903

  16. A 12,000-Yr Pollen Record off Cape Hatteras: Pollen Sources and Mechanisms of Pollen Dispersion

    NASA Technical Reports Server (NTRS)

    Naughton, F.; Keigwin, L.; Peteet, D.; Costas, S.; Desprat, S.; Oliveira, D.; de Vernal, A.; Voelker, A.; Abrantes, F.

    2015-01-01

    Integrating both marine and terrestrial signals from the same sediment core is one of the primary challenges for understanding the role of ocean-atmosphere coupling throughout past climate changes. It is therefore vital to understand how the pollen signal of a given marine record reflects the vegetation changes of the neighboring continent. The comparison between the pollen record of marine core JPC32 (KNR178JPC32) and available terrestrial pollen sequences from eastern North America over the last 12,170 years indicates that the pollen signature off Cape Hatteras gives an integrated image of the regional vegetation encompassing the Pee Dee river, Chesapeake and Delaware hydrographic basins and is reliable in reconstructing the past climate of the adjacent continent. Extremely high quantities of pollen grains included in the marine sediments off Cape Hatteras were transferred from the continent to the sea, at intervals 10,100-8800 cal yr BP, 8300-7500 cal yr BP, 5800- 4300 cal yr BP and 2100-730 cal yr BP, during storm events favored by episodes of rapid sea-level rise in the eastern coast of US. In contrast, pollen grains export was reduced during 12,170-10,150 cal yr BP and 4200- 2200 cal yr BP, during episodes of intense continental dryness and slow sea level rise episodes or lowstands in the eastern coast of US. The near absence of reworked pollen grains in core JPC32 contrasts with the high quantity of reworked material in nearby but deeper located marine sites, suggesting that the JPC32 recordwas not affected by the DeepWestern Boundary Current (DWBC) since the end of the Younger Dryas and should be considered a key site for studying past climate changes in the western North Atlantic.

  17. Colour learning when foraging for nectar and pollen: bees learn two colours at once.

    PubMed

    Muth, Felicity; Papaj, Daniel R; Leonard, Anne S

    2015-09-01

    Bees are model organisms for the study of learning and memory, yet nearly all such research to date has used a single reward, nectar. Many bees collect both nectar (carbohydrates) and pollen (protein) on a single foraging bout, sometimes from different plant species. We tested whether individual bumblebees could learn colour associations with nectar and pollen rewards simultaneously in a foraging scenario where one floral type offered only nectar and the other only pollen. We found that bees readily learned multiple reward-colour associations, and when presented with novel floral targets generalized to colours similar to those trained for each reward type. These results expand the ecological significance of work on bee learning and raise new questions regarding the cognitive ecology of pollination. PMID:26423070

  18. Design of a downscaling method to estimate continuous data from discrete pollen monitoring in Tunisia.

    PubMed

    Orlandi, Fabio; Oteros, Jose; Aguilera, Fátima; Ben Dhiab, Ali; Msallem, Monji; Fornaciari, Marco

    2014-07-01

    The study of microorganisms and biological particulate matter that transport passively through air is very important for an understanding of the real quality of air. Such monitoring is essential in several specific areas, such as public health, allergy studies, agronomy, indoor and outdoor conservation, and climate-change impact studies. Choosing the suitable monitoring method is an important step in aerobiological studies, so as to obtain reliable airborne data. In this study, we compare olive pollen data from two of the main air traps used in aerobiology, the Hirst and Cour air samplers, at three Tunisian sampling points, for 2009 to 2011. Moreover, a downscaling method to perform daily Cour air sampler data estimates is designed. While Hirst air samplers can offer daily, and even bi-hourly data, Cour air samplers provide data for longer discrete sampling periods, which limits their usefulness for daily monitoring. Higher quantities of olive pollen capture were generally detected for the Hirst air sampler, and a downscaling method that is developed in this study is used to model these differences. The effectiveness of this downscaling method is demonstrated, which allows the potential use of Cour air sampler data series. These results improve the information that new Cour data and, importantly, historical Cour databases can provide for the understanding of phenological dates, airborne pollination curves, and allergenicity levels of air. PMID:24824947

  19. Morphology and structure of the pollen cone and pollen grain of the Araucaria species from Argentina.

    PubMed

    Del Fueyo, Georgina M; Caccavari, Marta A; Dome, Elizabeth A

    2008-04-01

    The pollen cone and the pollen grain of the two Argentinean species of Araucaria are described with LM, SEM and TEM. Primordia of pollen cones are formed in April and May and reach maturity by mid-October in A. angustifolia (Bert.) O. Kuntze and by mid-November in A. araucana. (Mol.) K. Koch. Characters of the mature pollen cones and microsporophylls between both taxa are clearly differentiated. Pollen grains are spheroidal-subspheroidal, inaperturate, and asaccate with granulate exine and a subequatorial annular area that corresponds to the sexine thickness. Sculpturing consists of irregularly dispersed granules that are sometimes fused to each other (A. angustifolia) or forming microrugulae (A. araucana). Microgranules and microspinules are also present. The pollen wall ultrastructure is formed by a granular ectexine and lamellated endexine. Granular elements in A. angustifolia are more loosely disposed, form more interstices, and are gradually smaller towards the endexine than in A. araucana. To asses the probable relationships within the family, we compared the pollen grains of the two Araucaria species with those of other extant genera (Agathis, Wollemia) and also with fossil pollen (Araucariacites, Balmeiopsis, Cyclusphaera, Dilwynites) attributed to Araucariaceae. PMID:18669323

  20. Ultraviolet radiation environment of pollen and its effect on pollen germination. Final report

    SciTech Connect

    Not Available

    1981-12-01

    The damage to pollen caused by natural ultraviolet radiation was investigated. Experimental and literature research into the UV radiation environment is reported. Viability and germination of wind and insect pollinated species were determined. Physiological, developmental, and protective factors influencing UV sensitivity of binucleate, advanced binucleate, and trinucleate pollen grains are compared.

  1. The ultraviolet radiation environment of pollen and its effect on pollen germination

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The damage to pollen caused by natural ultraviolet radiation was investigated. Experimental and literature research into the UV radiation environment is reported. Viability and germination of wind and insect pollinated species were determined. Physiological, developmental, and protective factors influencing UV sensitivity of binucleate, advanced binucleate, and trinucleate pollen grains are compared.

  2. Receptor-Like Kinase RUPO Interacts with Potassium Transporters to Regulate Pollen Tube Growth and Integrity in Rice.

    PubMed

    Liu, Lingtong; Zheng, Canhui; Kuang, Baijan; Wei, Liqin; Yan, Longfeng; Wang, Tai

    2016-07-01

    During sexual reproduction of flowering plants, the pollen tube grows fast and over a long distance within the pistil to deliver two sperms for double fertilization. Growing plant cells need to communicate constantly with external stimuli as well as monitor changes in surface tension of the cell wall and plasma membrane to coordinate these signals and internal growth machinery; however, the underlying mechanisms remain largely unknown. Here we show that the rice member of plant-specific receptor-like kinase CrRLK1Ls subfamily, Ruptured Pollen tube (RUPO), is specifically expressed in rice pollen. RUPO localizes to the apical plasma membrane and vesicle of pollen tubes and is required for male gamete transmission. K+ levels were greater in pollen of homozygous CRISPR-knockout lines than wild-type plants, and pollen tubes burst shortly after germination. We reveal the interaction of RUPO with high-affinity potassium transporters. Phosphorylation of RUPO established and dephosphorylation abolished the interaction. These results have revealed the receptor-like kinase as a regulator of high-affinity potassium transporters via phosphorylation-dependent interaction, and demonstrated a novel receptor-like kinase signaling pathway that mediates K+ homeostasis required for pollen tube growth and integrity. PMID:27447945

  3. Receptor-Like Kinase RUPO Interacts with Potassium Transporters to Regulate Pollen Tube Growth and Integrity in Rice

    PubMed Central

    Liu, Lingtong; Zheng, Canhui; Kuang, Baijan; Wei, Liqin; Yan, Longfeng; Wang, Tai

    2016-01-01

    During sexual reproduction of flowering plants, the pollen tube grows fast and over a long distance within the pistil to deliver two sperms for double fertilization. Growing plant cells need to communicate constantly with external stimuli as well as monitor changes in surface tension of the cell wall and plasma membrane to coordinate these signals and internal growth machinery; however, the underlying mechanisms remain largely unknown. Here we show that the rice member of plant-specific receptor-like kinase CrRLK1Ls subfamily, Ruptured Pollen tube (RUPO), is specifically expressed in rice pollen. RUPO localizes to the apical plasma membrane and vesicle of pollen tubes and is required for male gamete transmission. K+ levels were greater in pollen of homozygous CRISPR-knockout lines than wild-type plants, and pollen tubes burst shortly after germination. We reveal the interaction of RUPO with high-affinity potassium transporters. Phosphorylation of RUPO established and dephosphorylation abolished the interaction. These results have revealed the receptor-like kinase as a regulator of high-affinity potassium transporters via phosphorylation-dependent interaction, and demonstrated a novel receptor-like kinase signaling pathway that mediates K+ homeostasis required for pollen tube growth and integrity. PMID:27447945

  4. Labyrinths, columns and cavities: new internal features of pollen grain walls in the Acanthaceae detected by FIB-SEM.

    PubMed

    House, Alisoun; Balkwill, Kevin

    2016-03-01

    External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants, especially the Acanthaceae which are noted for pollen diversity. However internal pollen wall features have received far less attention due to the difficulty of examining the wall structure. Advancing technology in the field of microscopy has made it possible, with the use of a focused ion beam-scanning electron microscope (FIB-SEM), to view the structure of pollen grain walls in far greater detail and in three dimensions. In this study the wall structures of 13 species from the Acanthaceae were investigated for features of potential systematic relevance. FIB-SEM was applied to obtain precise cross sections of pollen grains at selected positions for examining the wall ultrastructure. Exploratory studies of the exine have thus far identified five basic structural types. The investigations also show that similar external pollen wall features may have a distinctly different internal structure. FIB-SEM studies have revealed diverse internal pollen wall features which may now be investigated for their systematic and functional significance. PMID:26698154

  5. Experimental forensic studies of the preservation of pollen in vehicle fires.

    PubMed

    Morgan, R M; Flynn, J; Sena, V; Bull, P A

    2014-03-01

    The implications of the recent recommendations of the Law Commission regarding the use of admissibility tests have the potential to be far reaching for forensic disciplines that rely on the expertise of highly qualified expert witnesses. These disciplines will need a concomitant body of peer-reviewed experiments that provides a basis for the interpretations of such evidence presented in court. This paper therefore, presents such results from two experiments which were undertaken to address specific issues that were raised in cases presented in the British courtroom. These studies demonstrate that there is a variability in the persistence of Lily, Daffodil and Tulip pollen when exposed to high temperatures between 0.5min and 1440min (24h). It was possible to identify all three pollen types after 30min of exposure to 400°C, and after shorter time frames the threshold for successful identification was 700°C after 0.5min for all pollen types tested and 500°C for Daffodil and Lily after 5min of heat exposure. Over longer time periods (18h (1080min)) the different pollen types were found to persist in a viable form for identification at 300°C (Lily), 200°C (Daffodil) and 50°C (Tulip). These findings, albeit from a small sample of pollen types, provide empirical contextual information that would contribute to such evidence having sufficient scientific weight to meet admissibility criteria and be viable evidence for a court. These studies demonstrate the value in seeking pollen evidence from even such extreme crime scenes as encountered in vehicular fires. PMID:24630324

  6. Pollen evidence for late pleistocene bering land bridge environments from Norton Sound, Northeastern Bering Sea, Alaska

    USGS Publications Warehouse

    Ager, T.A.; Phillips, R.L.

    2008-01-01

    After more than half a century of paleoenvironmental investigations, disagreements persist as to the nature of vegetation type and climate of the Bering land bridge (BLB) during the late Wisconsin (Sartan) glacial interval. Few data exist from sites on the former land bridge, now submerged under the Bering and Chukchi Seas. Two hypotheses have emerged during the past decade. The first, based on pollen data from Bering Sea islands and adjacent mainlands of western Alaska and Northeast Siberia, represents the likely predominant vegetation on the Bering land bridge during full-glacial conditions: graminoid-herb-willow tundra vegetation associated with cold, dry winters and cool, dry summer climate. The second hypothesis suggests that dwarf birch-shrub-herb tundra formed a broad belt across the BLB, and that mesic vegetation was associated with cold, snowier winters and moist, cool summers. As a step towards resolving this controversy, a sediment core from Norton Sound, northeastern Bering Sea was radiocarbon dated and analyzed for pollen content. Two pollen zones were identified. The older, bracketed by radiocarbon ages of 29,500 and 11,515 14C yr BP, contains pollen assemblages composed of grass, sedge, wormwood, willow, and a variety of herb (forb) taxa. These assemblages are interpreted to represent graminoid-herb-willow tundra vegetation that developed under an arid, cool climate regime. The younger pollen zone sediments were deposited about 11,515 14C yr BP, when rising sea level had begun to flood the BLB. This younger pollen zone contains pollen of birch, willow, heaths, aquatic plants, and spores of sphagnum moss. This is interpreted to represent a Lateglacial dwarf birch-heath-willow-herb tundra vegetation, likely associated with a wetter climate with deeper winter snows, and moist, cool summers. This record supports the first hypothesis, that graminoid-herb-willow tundra vegetation extended into the lowlands of the BLB during full glacial conditions of the

  7. The pollen-specific R-SNARE/longin PiVAMP726 mediates fusion of endo- and exocytic compartments in pollen tube tip growth.

    PubMed

    Guo, Feng; McCubbin, Andrew G

    2012-05-01

    The growing pollen tube apex is dedicated to balancing exo- and endocytic processes to form a rapidly extending tube. As perturbation of either tends to cause a morphological phenotype, this system provides tractable model for studying these processes. Vesicle-associated membrane protein 7s (VAMP7s) are members of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family that mediate cognate membrane fusion but their role in pollen tube growth has not been investigated. This manuscript identifies PiVAMP726 of Petunia inflata as a pollen-specific VAMP7 that localizes to the inverted cone of transport vesicles at the pollen tube tip. The endocytic marker FM4-64 was found to colocalize with yellow fluorescent protein (YFP)-PiVAMP726, which is consistent with PiVAMP726 containing an amino-acid motif implicated in endosomal localization, At high overexpression levels, YFP- PiVAMP726 inhibited growth and caused the formation of novel membrane compartments within the pollen tube tip. Functional dissection of PiVAMP726 implicated the N-terminal longin domain in negative regulation of the SNARE activity, but not localization of PiVAMP726. Expression of the constitutively active C-terminal SNARE domain alone, in pollen tubes, generated similar phenotypes to the full-length protein, but the truncated domain was more potent than the wild-type protein at both inhibiting growth and forming the novel membrane compartments. Both endo- and exocytic markers localized to these compartments in addition to YFP-PiVAMP726, leading to the speculation that PiVAMP726 might be involved in the recycling of endocytic vesicles in tip growth. PMID:22345643

  8. A high-resolution angiosperm pollen reference record covering Albian mid-latitude coastal deposits (Lusitanian Basin, Portugal)

    NASA Astrophysics Data System (ADS)

    Horikx, Maurits; Dinis, Jorge L.; Heimhofer, Ulrich

    2013-04-01

    The Lusitanian Basin in Portugal is one of the most important areas to investigate the rise and radiation of early angiosperms. Here, important micro-, macro- and mesofossil remains including pollen, reproductive organs, fruits and seeds have been found. In this study, a high-resolution Early to Late Albian pollen record from a thick (~160m) coastal succession in the Lusitanian Basin containing mixed carbonate-siliciclastic near-shore deposits is generated. The outcrop is located near the town of Ericeira (São Julião) and exhibits some important new features compared to existing records from the Lusitanian basin. The comparatively proximal depositional setting and high sedimentation rate of the São Julião outcrop is well suited for high-resolution palynological sampling compared to previously studied, more distal outcrops. In addition, the succession covers almost the entire Albian including a thick interval representing Late Albian strata. Dating of the succession was obtained using dinoflagellate cyst biostratigraphy, bulk C-isotope analysis and strontium isotope analysis of low-Mg oysters and rudist shells. The high-resolution pollen record shows a distinct radiation pattern of early angiosperm pollen as well as significant changes in the accompanying palynoflora. During most of the section gymnosperm pollen types such as Classopollis spp., Inaperturopollenites spp. and Exesipollenites spp. are dominant. Angiosperm pollen abundances do not exceed 20%, although angiosperms increase slightly from the Early Albian onwards. Monoaperturate grains of magnoliid or monocot affinity remain the most dominant angiosperm pollen type, both in abundances and diversity. Tricolpate and zonoaperturate pollen grains are also present. In addition, the occurrence of several odd-shaped Dichastopollenites-type pollen types is intriguing. The palynological results indicate a warm and dry climate during most of the Albian, although a rise in the spores over pollen ratio in the

  9. Allergenicity of the pollen of Pistacia.

    PubMed

    Keynan, N; Tamir, R; Waisel, Y; Reshef, A; Spitz, E; Shomer-Ilan, A; Geller-Bernstein, C

    1997-03-01

    Differences in IgE binding and skin responses to pollen extracts of four species of Pistacia, and some immunochemical characteristics of this pollen were investigated. The incidence of positive SPT among atopic patients varied between 31.5% to the pollen extracts of P. vera and 24.6% to P. palaestina. The antigens are located on the exine of the grains as well as in their cytoplasm. Some of the antigens are common to all four species, whereas others seem to be specific. Cross-reactivity was found among the four species of Pistacia and between them and Schinus terebintifolious. Five conspicuous IgE-binding bands were observed in the immunoblots of the four examined species, the bands of 49, 57, 64, 68, and 79 kDa. The 36-37-kDa band of P. lentiscus and the 60- and 84-kDa bands of P. atlantica and P. vera were also noticeable. As the flowering seasons of Pistacia and Schinus do not overlap, the patients are exposed to such pollen for more than 4 months a year. Apparently, Pistacia pollen is a major source of allergy. PMID:9140524

  10. Effect of water absorption on pollen adhesion.

    PubMed

    Lin, Haisheng; Lizarraga, Leonardo; Bottomley, Lawrence A; Carson Meredith, J

    2015-03-15

    Pollens possess a thin liquid coating, pollenkitt, which plays a major role in adhesion by forming capillary menisci at interfaces. Unfortunately, the influence of humidity on pollenkitt properties and capillary adhesion is unknown. Because humidity varies widely in the environment, the answers have important implications for better understanding plant reproduction, allergy and asthma, and pollen as atmospheric condensation nuclei. Here, pollenkitt-mediated adhesion of sunflower pollen to hydrophilic and hydrophobic surfaces was measured as a function of humidity. The results quantify for the first time the significant water absorption of pollenkitt and the resulting complex dependence of adhesion on humidity. On hydrophilic Si, adhesion increased with increasing RH for pollens with or without pollenkitt, up to 200nN at 70% RH. In contrast, on hydrophobic PS, adhesion of pollenkitt-free pollen is independent of RH. Surprisingly, when pollenkitt was present adhesion forces on hydrophobic PS first increased with RH up to a maximum value at 35% RH (∼160nN), and then decreased with further increases in RH. Independent measurement of pollenkitt properties is used with models of capillary adhesion to show that humidity-dependent changes in pollenkitt wetting and viscosity are responsible for this complex adhesion behavior. PMID:25524008

  11. The Airborne Laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-09-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  12. Performance of a scanning mobility particle sizer in measuring diverse types of airborne nanoparticles: Multi-walled carbon nanotubes, welding fumes, and titanium dioxide spray.

    PubMed

    Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-07-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the "gold standard" for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing "monodisperse" aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in some test

  13. Performance of a Scanning Mobility Particle Sizer in Measuring Diverse Types of Airborne Nanoparticles: Multi-Walled Carbon Nanotubes, Welding Fumes, and Titanium Dioxide Spray

    PubMed Central

    Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-01-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the “gold standard” for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing “monodisperse” aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in

  14. NASA Airborne Lidar July 1991

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar July 1991 Data from the 1991 NASA Langley Airborne Lidar flights following the eruption of Pinatubo in July ... and Osborn [1992a, 1992b]. Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  15. NASA Airborne Lidar May 1992

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar May 1992 An airborne Nd:YAG (532 nm) lidar was operated by the NASA Langley Research Center about a year following the June 1991 eruption of ... Osborn [1992a, 1992b].  Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  16. Pollen sensitivity to ultraviolet-B (UV-B) suggests floral structure evolution in alpine plants

    PubMed Central

    Zhang, Chan; Yang, Yong-Ping; Duan, Yuan-Wen

    2014-01-01

    Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Floral forms were categorized as either protecting or exposing pollen grains to UV-B. The floral materials of plants with exposed and protected pollen grains were able to block UV-B at similar levels. Exposure to UV-B radiation in vitro resulted in a significantly greater loss of viability in pollen from plant species with protective floral structures. The pronounced sensitivity of protected pollen to UV-B radiation was associated with the type of flower structure. These findings demonstrate that UV-B plays an important role in the evolution of protective floral forms in alpine plants. PMID:24682234

  17. Spring Allergies? Don't Assume It's Only Pollen

    MedlinePlus

    ... html Spring Allergies? Don't Assume It's Only Pollen Identifying your triggers is the first step toward ... reducing your symptoms, experts say. You may believe pollen is the culprit. But, other substances such as ...

  18. A Pollen Primer | NIH MedlinePlus the Magazine

    MedlinePlus

    ... please turn Javascript on. Feature: Managing Allergies A Pollen Primer Past Issues / Summer 2011 Table of Contents ... National Institute of Environmental Health Sciences (NIEHS) . Plant Pollen Ragweed and other weeds, such as curly dock, ...

  19. Quantification of airway deposition of intact and fragmented pollens.

    PubMed

    Horváth, Alpár; Balásházy, Imre; Farkas, Arpád; Sárkány, Zoltán; Hofmann, Werner; Czitrovszky, Aladár; Dobos, Erik

    2011-12-01

    Although pollen is one of the most widespread agents that can cause allergy, its airway transport and deposition is far from being fully explored. The objective of this study was to characterize the airway deposition of pollens and to contribute to the debate related to the increasing number of asthma attacks registered after thunderstorms. For the quantification of the deposition of inhaled pollens in the airways computer simulations were performed. Our results demonstrated that smaller and fragmented pollens may penetrate into the thoracic airways and deposit there, supporting the theory that fragmented pollen particles are responsible for the increasing incidence of asthma attacks following thunderstorms. Pollen deposition results also suggest that children are the most exposed to the allergic effects of pollens. Finally, pollens between 0.5 and 20 μm deposit more efficiently in the lung of asthmatics than in the healthy lung, especially in the bronchial region. PMID:21563012

  20. [Hypersensitivity to pollen of Olea europea in patients with pollen allergy in Zadar County, Croatia].

    PubMed

    Skitarelić, Natasa; Mazzi, Antun; Skitarelić, Neven; Misulić, Josko; Vuletić, Ana

    2010-06-01

    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 specific IgE antibodies. For statistical analysis we used the chi-square test. Hypersensitivity to Olea europea pollen was confirmed 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 findings show the lowest hypersensitivity to olive pollen in the Mediterranean. A comparison with our two earlier studies did not show any fluctuation in this kind of hypersensitivity. PMID:20587396

  1. Anatomical and pollen ornamentation study on Hymenocrater species in North East of Iran.

    PubMed

    Jafari, A; Jafarzadeh, F

    2008-09-01

    The present study tends to investigate the anatomy and palynology of Hymenocrater species in Northeast of Iran. To conduct the comparative study of anatomy characters, sections from stem and leaf were prepared using microtome and differential staining. In this part of investigation, arrangement of vessel in stem, stoma type and arrangement of mesophyll in leaf were studied. For the palynology study, too a comparative investigation on the species showed, the pollen was problate spheroidal, hexacolpate, bireticulate and semitectate. Finally a variation between the shape of lumina in eu-reticulate and supra reticulate of pollen was observed. PMID:19266931

  2. Quantification of Juniperus Ashei Pollen Production for the Development of Forecasting Models

    NASA Technical Reports Server (NTRS)

    Bunderson, L. D.; Levetin, E.

    2010-01-01

    Juniperus ashei pollen is considered one of the most allergenic species of Cupressaceae in North America. Juniperus ashei is distributed throughout central Texas, Northern Mexico, the Arbuckle Mountains of south central Oklahoma, and the Ozark Mountains of northern Arkansas and southwestern Missouri. The large amount of airborne pollen that J. ashei produces affects inhabitants of cities and towns adjacent to juniper woodland areas and because juniper pollen can be transported over long distances, it affects populations that are far away. In order to create a dynamic forecast system for allergy and asthma sufferers, pollen production must be estimated. Estimation of pollen production requires the estimation of male cone production. Two locations in the Arbuckle Mountains of Oklahoma and 4 locations in the Edwards Plateau region of Texas were chosen as sampling sites. Trees were measured to determine approximate size. Male to female ratio was determined and pollen cone production was estimated using a qualitative scale from 0 to 2. Cones were counted from harvested 1/8 sections of representative trees. The representative trees were measured and approximate surface area of the tree was calculated. Using the representative tree data, the number of cones per square meter was calculated for medium production (1) and high production (2) trees. These numbers were extrapolated to calculate cone production in other trees sampled. Calibration was achieved within each location's sub-plot by counting cones on 5 branches collected from 5 sides of both high production and medium production trees. The total area sampled in each location was 0.06 hectare and total cone production varied greatly from location to location. The highest production area produced 5.8 million cones while the lowest production area produced 72,000 cones. A single representative high production tree in the Arbuckle Mountains produced 1.38 million cones. The number of trees per location was relatively

  3. Prey and Pollen Food Choice Depends on Previous Diet in an Omnivorous Predatory Mite.

    PubMed

    Schuldiner-Harpaz, Tarryn; Coll, Moshe; Weintraub, Phyllis G

    2016-08-01

    The time allocated by omnivorous predators to consuming prey versus plant-provided foods (e.g., pollen) directly influences their efficacy as biocontrol agents of agricultural pests. Nonetheless, diet shifting between these two very different food sources remains poorly understood. We hypothesized that previous diet composition influences subsequent choice of prey and plant food types. We tested this hypothesis by observing the foraging choices of Amblyseius swirskii (Athias-Henriot) mites (Mesostigmata: Phytoseiidae), which were first maintained on either prey (broad mites) or corn pollen, and then offered familiar and unfamiliar foods. A. swirskii exhibited strong fidelity to familiar food, whether prey or pollen, suggesting there are physiological or behavioral costs involved in shifting between such different foods. Results illustrate the importance of previous diet for subsequent pest consumption by omnivorous natural enemies. PMID:27271945

  4. Pollen tubes and the physical world.

    PubMed

    Winship, Lawrence J; Obermeyer, Gerhard; Geitmann, Anja; Hepler, Peter K

    2011-07-01

    The primary goal of our previous opinion paper (Winship, L.J. et al. (2010) Trends Plant Sci. 15, 363-369) [1] was to put two models for the control of pollen tube growth on the same theoretical and biophysical footing, and to then test both for consistency with basic principles and with experimental data. Our central thesis, then and now, is that the biophysical and biochemical mechanisms that enable pollen tubes to grow and to respond to their environment evolved in a physical context constrained by known, inescapable principles. First, pressure is a scalar, not a vector quantity. Second, the water movement in and out of plant cells that generates pressure is passive, not active, and is controlled by differences in water potential. Here we respond to the issues raised by Zonia and Munnik (Trends Plant Sci. 2011; this issue) [2] in the light of new evidence concerning turgor pressure and pollen tube growth rates. PMID:21536475

  5. Wettable and Unsinkable: The Hydrodynamics of Saccate Pollen Grains in Relation to the Pollination Mechanism in the Two New Zealand Species of Prumnopitys Phil. (Podocarpaceae)

    PubMed Central

    SALTER, JOSHUA; MURRAY, BRIAN G.; BRAGGINS, JOHN E.

    2002-01-01

    The pollination mechanism of most genera of the Podocarpaceae involves inverted ovules, a pollination drop and bisaccate pollen grains. Saccate grains have sometimes been referred to as ‘non‐wettable’ due to their buoyant properties, while non‐saccate pollen grains have been described as ‘wettable’. The hydrodynamic properties of saccate pollen grains of seven podocarp species in five genera, Dacrydium Sol. ex G. Forst., Dacrycarpus (Endl.) de Laub., Manoao Molloy, Podocarpus L‘Hér. ex Pers. and Prumnopitys Phil. have been tested in water, together with saccate and non‐saccate pollen of four other conifer genera, Cedrus Trew (Pinaceae), Cephalotaxus Siebold & Zucc. ex Endl. (Cephalotaxaceae), Cupressus L. (Cupressaceae) and Phyllocladus Rich. ex Mirb. (Phyllocladaceae), and spores of three fern species and one lycopod species. All four spore types studied were non‐wettable, whereas the bisaccate and trisaccate pollen types, like all other conifer pollen types, were wettable, enabling the grains to cross the surface tension barrier of water. Once past this barrier, grain behaviour was governed by presence or absence of sacci. Non‐saccate and vestigially saccate grains sank, whereas saccate grains behaved like air bubbles, floating up to the highest point. In addition, the grains were observed to float in water with sacci uppermost, consistent with the suggestion that distally placed sacci serve to orientate the germinal furrow of the pollen grain towards the nucellus of an inverted ovule. Observations of pollen grains in the pollen chambers of naturally pollinated Prumnopitys ovules confirmed this. The combination of buoyancy and wettability in saccate pollen has implications for the efficiency of the typical podocarp pollination mechanism. PMID:12099344

  6. Thunderstorm asthma due to grass pollen.

    PubMed

    Suphioglu, C

    1998-08-01

    It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. Moreover, grass pollen is also responsible for triggering allergic asthma, gaining impetus as a result of the 1987/1989 Melbourne and 1994 London thunderstorm-associated asthma epidemics. However, grass pollen is too large to gain access into the lower airways to trigger the asthmatic response and micronic particles <5 micro m are required to trigger the response. We have successfully shown that ryegrass pollen ruptures upon contact with water, releasing about 700 starch granules which not only contain the major allergen Lol p 5, but have been shown to trigger both in vitro and in vivo IgE-mediated responses. Furthermore, starch granules have been isolated from the Melbourne atmosphere with 50-fold increase following rainfall. Free grass pollen allergen molecules have been recently shown to interact with other particles including diesel exhaust carbon particles, providing a further transport mechanism for allergens to gain access into lower airways. In this review, implication and evidence for grass pollen as a trigger of thunderstorm-associated asthma is presented. Such information is critical and mandatory for patient education and training in their allergen avoidance programs. More importantly, patients with serum IgE to group 5 allergens are at high risk of allergic asthma, especially those not protected by medication. Therefore, a system to determine the total atmospheric allergen load and devising of an effective asthma risk forecast is urgently needed and is subject to current investigation. PMID:9693274

  7. Airborne antenna pattern calculations

    NASA Technical Reports Server (NTRS)

    Knerr, T. J.; Schaffner, P. R.; Mielke, R. R.; Gilreath, M. C.

    1980-01-01

    A procedure for numerically calculating radiation patterns of fuselage-mounted airborne antennas using the Volumetric Pattern Analysis Program is presented. Special attention is given to aircraft modeling. An actual case study involving a large commercial aircraft is included to illustrate the analysis procedure.

  8. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

    The heating, ventilating, and air conditioning (HVAC) systems in older buildings often do not adequately handle air-borne contaminants. Outlines a three-stage Indoor Air Quality (IAQ) assessment and describes a case in point at a Pittsburgh, Pennsylvania, school. (MLF)

  9. Airborne Fraunhofer Line Discriminator

    NASA Technical Reports Server (NTRS)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  10. Airborne Remote Sensing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA imaging technology has provided the basis for a commercial agricultural reconnaissance service. AG-RECON furnishes information from airborne sensors, aerial photographs and satellite and ground databases to farmers, foresters, geologists, etc. This service produces color "maps" of Earth conditions, which enable clients to detect crop color changes or temperature changes that may indicate fire damage or pest stress problems.

  11. Floral sources to Tetragonisca angustula (Hymenoptera: Apidae) and their pollen morphology in a Southeastern Brazilian Atlantic Forest.

    PubMed

    Braga, Juliana Almeida; Sales, Erika Oliveira; Soares Neto, João; Conde, Marilena Menezes; Barth, Ortrud Monika; Maria, Cristina Lorenzon

    2012-12-01

    The stingless bees are important flowers visitors of several plant species, due to their feeding habits and foraging behavior, constituting an important group to maintain biodiversity and the dynamics of tropical communities. Among stingless bees, Tetragonisca angustula is widely distributed in tropical habitats, and has been considered an important pollinator of different plant families. To support a rational economic use of this group, there is a need to characterize the plant species that represent important sources as part of their diet, as preferred, alternative or casual food sources. The aim of this survey was to distinguish the plant species that T. angustula visited most often. The study was undertaken in four regions of the Atlantic Rainforest in Rio de Janeiro state (Brazil) over a year from March 2008 to February 2009. For this, we collected bees, flowering plants and bee pollen loads from the four sites, and evaluated pollen morphology in the laboratory. Field observations showed the presence of plants belonging to ten different families and pollen loads showed the presence of pollen types belonging to 26 plant families. There were strong differences between pollen types, especially regarding pollen grain shape. The present survey suggests a high value of these plant species as trophic resources for the T. angustula in the understory of Atlantic Rainforest. Changes in these fragments of this forest may compromise the availability of resources for Tetragonisca angustula species and other stingless bees. PMID:23342504

  12. Lignin biomarkers and pollen in the postglacial sediment of an Alaskan Lake

    NASA Astrophysics Data System (ADS)

    Hu, Feng Sheng; Hedges, John I.; Gordon, Elizabeth S.; Brubaker, Linda B.

    1999-05-01

    organic matter and that p-coumaric acid is labile, it is important to consider pollen as a nonwoody tissue type when lignin biomarkers are used to determine the sources of vascular-plant material in sediments.

  13. Composition of polyphenol and polyamide compounds in common ragweed (Ambrosia artemisiifolia L.) pollen and sub-pollen particles.

    PubMed

    Mihajlovic, Luka; Radosavljevic, Jelena; Burazer, Lidija; Smiljanic, Katarina; Cirkovic Velickovic, Tanja

    2015-01-01

    Phenolic composition of Ambrosia artemisiifolia L. pollen and sub-pollen particles (SPP) aqueous extracts was determined, using a novel extraction procedure. Total phenolic and flavonoid content was determined, as well as the antioxidative properties of the extract. Main components of water-soluble pollen phenolics are monoglycosides and malonyl-mono- and diglycosides of isorhamnetin, quercetin and kaempferol, while spermidine derivatives were identified as the dominant polyamides. SPP are similar in composition to pollen phenolics (predominant isorhamnetin and quercetin monoglycosides), but lacking small phenolic molecules (<450Da). Ethanol-based extraction protocol revealed one-third lower amount of total phenolics in SPP than in pollen. For the first time in any pollen species, SPP and pollen phenolic compositions were compared in detail, with an UHPLC/ESI-LTQ-Orbitrap-MS-MS approach, revealing the presence of spermidine derivatives in both SPP and pollen, not previously reported in Ambrosia species. PMID:25468540

  14. Effects of NO2 and Ozone on Pollen Allergenicity

    PubMed Central

    Frank, Ulrike; Ernst, Dieter

    2016-01-01

    This mini-review summarizes the available data of the air pollutants NO2 and ozone on allergenic pollen from different plant species, focusing on potentially allergenic components of the pollen, such as allergen content, protein release, IgE-binding, or protein modification. Various in vivo and in vitro studies on allergenic pollen are shown and discussed. PMID:26870080

  15. Diversity and conservation in maize pollen: Phenotypes and transcripts

    EPA Science Inventory

    In addition to its crucial role in seed production, pollen serves as a vector for gene flow between plant populations. Recently, pollen was identified as a mechanism for introduction of transgenes into non-transgenic populations. To investigate the genetic basis for pollen fitn...

  16. Pollen Biology of Ornamental Ginger (Hedychium spp. J. Koenig)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An improved in vitro pollen germination assay was developed to assess the viability of stored Hedychium pollen. The effect of polyethylene glycol (PEG) (10, 15, and 20% w/v) on pollen germination and tube growth was evaluated for H. longicornutum and two commercial Hedychium cultivars, ‘Orange Brush...

  17. Effects of NO2 and Ozone on Pollen Allergenicity.

    PubMed

    Frank, Ulrike; Ernst, Dieter

    2016-01-01

    This mini-review summarizes the available data of the air pollutants NO2 and ozone on allergenic pollen from different plant species, focusing on potentially allergenic components of the pollen, such as allergen content, protein release, IgE-binding, or protein modification. Various in vivo and in vitro studies on allergenic pollen are shown and discussed. PMID:26870080

  18. Pollen Germination--A Challenging and Educational Experiment.

    ERIC Educational Resources Information Center

    Tse, H. L. H.; Chan, G. Y. S.

    2001-01-01

    Summarizes the recent research on pollen germination and introduces some basic studies on pollen tube growth that can be conducted in a secondary school laboratory. Discusses the use of a light microscope and refrigerator to study pollen. (Contains 13 references.) (Author/YDS)

  19. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  20. Isolation of Cytoplasmic Enzymes from Pollen 1

    PubMed Central

    Weeden, Norman F.; Gottlieb, Leslie D.

    1980-01-01

    The cytoplasmic isozyme of many cytoplasmic-organelle isozyme pairs, as well as other cytoplasmic enzymes in plants, can be readily obtained from pollen by soaking it in an appropriate buffer for 4 hours. Enzymes localized in subcellular organelles appear not to be released during the soaking period, although they are released if the pollen is crushed. The technique is a useful initial step in studies of subcellular localization of enzymes or for obtaining small quantities of cytoplasmic enzymes free of organellar contaminants. Images PMID:16661444

  1. Characterization of FAB1 phosphatidylinositol kinases in Arabidopsis pollen tube growth and fertilization.

    PubMed

    Serrazina, Susana; Dias, Fernando Vaz; Malhó, Rui

    2014-08-01

    In yeast and animal cells, phosphatidylinositol-3-monophosphate 5-kinases produce phosphatidylinositol (3,5)-bisphosphate (PtdIns(3,5)P2) and have been implicated in endomembrane trafficking and pH control in the vacuole. In plants, PtdIns(3,5)P2 is synthesized by the Fab1 family, four orthologs of which exist in Arabidopsis: FAB1A and FAB1B, both from the PIKfyve/Fab1 family; FAB1C and FAB1D, both without a PIKfyve domain and of unclear role. Using a reverse genetics and cell biology approach, we investigated the function of the Arabidopsis genes encoding FAB1B and FAB1D, both highly expressed in pollen. Pollen viability, germination and tube morphology were not significantly affected in homozygous mutant plants. In vivo, mutant pollen fertilized ovules leading to normal seeds and siliques. The same result was obtained when mutant ovules were fertilized with wild-type pollen. Double mutant pollen for the two genes was able to fertilize and develop plants no different from the wild-type. At the cellular level, fab1b and fab1d pollen tubes were found to exhibit perturbations in membrane recycling, vacuolar acidification and decreased production of reactive oxygen species (ROS). Subcellular imaging of FAB1B-GFP revealed that the protein localized to the endomembrane compartment, whereas FAB1D-GFP localized mostly to the cytosol and sperm cells. These results were discussed considering possible complementary roles of FAB1B and FAB1D. PMID:24807078

  2. New evidence of the reproductive organs of Glossopteris based on permineralized fossils from Queensland, Australia. II: pollen-bearing organ Ediea gen. nov.

    PubMed

    Nishida, Harufumi; Pigg, Kathleen B; Kudo, Kensuke; Rigby, John F

    2014-03-01

    Ediea homevalensis H. Nishida, Kudo, Pigg & Rigby gen. et sp. nov. is proposed for permineralized pollen-bearing structures from the Late Permian Homevale Station locality of the Bowen Basin, Queensland, Australia. The taxon represents unisexual fertile shoots bearing helically arranged leaves on a central axis. The more apical leaves are fertile microsporophylls bearing a pair of multi-branched stalks on their adaxial surfaces that each supports a cluster of terminally borne pollen sacs. Proximal to the fertile leaves there are several rows of sterile scale-like leaves. The pollen sacs (microsporangia) have thickened and dark, striate walls that are typical of the Arberiella type found in most pollen organs presumed to be of glossopterid affinity. An examination of pollen organs at several developmental stages, including those containing in situ pollen of the Protohaploxypinus type, provides the basis for a detailed analysis of these types of structures, which bear similarities to both compression/impression Eretmonia-type glossopterid microsporangiate organs and permineralized Eretmonia macloughlinii from Antarctica. These fossils demonstrate that at least some Late Permian pollen organs were simple microsporophyll-bearing shoot systems and not borne directly on Glossopteris leaves. PMID:24165836

  3. Hive-stored pollen of honey bees: many lines of evidence are consistent with pollen preservation, not nutrient conversion.

    PubMed

    Anderson, Kirk E; Carroll, Mark J; Sheehan, Tim; Lanan, Michele C; Mott, Brendon M; Maes, Patrick; Corby-Harris, Vanessa

    2014-12-01

    Honey bee hives are filled with stored pollen, honey, plant resins and wax, all antimicrobial to differing degrees. Stored pollen is the nutritionally rich currency used for colony growth and consists of 40-50% simple sugars. Many studies speculate that prior to consumption by bees, stored pollen undergoes long-term nutrient conversion, becoming more nutritious 'bee bread' as microbes predigest the pollen. We quantified both structural and functional aspects associated with this hypothesis using behavioural assays, bacterial plate counts, microscopy and 454 amplicon sequencing of the 16S rRNA gene from both newly collected and hive-stored pollen. We found that bees preferentially consume fresh pollen stored for <3 days. Newly collected pollen contained few bacteria, values which decreased significantly as pollen were stored >96 h. The estimated microbe to pollen grain surface area ratio was 1:1 000 000 indicating a negligible effect of microbial metabolism on hive-stored pollen. Consistent with these findings, hive-stored pollen grains did not appear compromised according to microscopy. Based on year round 454 amplicon sequencing, bacterial communities of newly collected and hive-stored pollen did not differ, indicating the lack of an emergent microbial community co-evolved to digest stored pollen. In accord with previous culturing and 16S cloning, acid resistant and osmotolerant bacteria like Lactobacillus kunkeei were found in greatest abundance in stored pollen, consistent with the harsh character of this microenvironment. We conclude that stored pollen is not evolved for microbially mediated nutrient conversion, but is a preservative environment due primarily to added honey, nectar, bee secretions and properties of pollen itself. PMID:25319366

  4. Hive-stored pollen of honey bees: many lines of evidence are consistent with pollen preservation, not nutrient conversion

    PubMed Central

    Anderson, Kirk E; Carroll, Mark J; Sheehan, Tim; Mott, Brendon M; Maes, Patrick; Corby-Harris, Vanessa

    2014-01-01

    Honey bee hives are filled with stored pollen, honey, plant resins and wax, all antimicrobial to differing degrees. Stored pollen is the nutritionally rich currency used for colony growth and consists of 40–50% simple sugars. Many studies speculate that prior to consumption by bees, stored pollen undergoes long-term nutrient conversion, becoming more nutritious ‘bee bread’ as microbes predigest the pollen. We quantified both structural and functional aspects associated with this hypothesis using behavioural assays, bacterial plate counts, microscopy and 454 amplicon sequencing of the 16S rRNA gene from both newly collected and hive-stored pollen. We found that bees preferentially consume fresh pollen stored for <3 days. Newly collected pollen contained few bacteria, values which decreased significantly as pollen were stored >96 h. The estimated microbe to pollen grain surface area ratio was 1:1 000 000 indicating a negligible effect of microbial metabolism on hive-stored pollen. Consistent with these findings, hive-stored pollen grains did not appear compromised according to microscopy. Based on year round 454 amplicon sequencing, bacterial communities of newly collected and hive-stored pollen did not differ, indicating the lack of an emergent microbial community co-evolved to digest stored pollen. In accord with previous culturing and 16S cloning, acid resistant and osmotolerant bacteria like Lactobacillus kunkeei were found in greatest abundance in stored pollen, consistent with the harsh character of this microenvironment. We conclude that stored pollen is not evolved for microbially mediated nutrient conversion, but is a preservative environment due primarily to added honey, nectar, bee secretions and properties of pollen itself. PMID:25319366

  5. Pollen Lipidomics: Lipid Profiling Exposes a Notable Diversity in 22 Allergenic Pollen and Potential Biomarkers of the Allergic Immune Response

    PubMed Central

    Bashir, Mohamed Elfatih H.; Lui, Jan Hsi; Palnivelu, Ravishankar; Naclerio, Robert M.; Preuss, Daphne

    2013-01-01

    Background/Aim Pollen grains are the male gametophytes that deliver sperm cells to female gametophytes during sexual reproduction of higher plants. Pollen is a major source of aeroallergens and environmental antigens. The pollen coat harbors a plethora of lipids that are required for pollen hydration, germination, and penetration of the stigma by pollen tubes. In addition to proteins, pollen displays a wide array of lipids that interact with the human immune system. Prior searches for pollen allergens have focused on the identification of intracellular allergenic proteins, but have largely overlooked much of the extracellular pollen matrix, a region where the majority of lipid molecules reside. Lipid antigens have attracted attention for their potent immunoregulatory effects. By being in close proximity to allergenic proteins on the pollen surface when they interact with host cells, lipids could modify the antigenic properties of proteins. Methodology/Principal Findings We performed a comparative pollen lipid profiling of 22 commonly allergenic plant species by the use of gas chromatography-mass spectroscopy, followed by detailed data mining and statistical analysis. Three experiments compared pollen lipid profiles. We built a database library of the pollen lipids by matching acquired pollen-lipid mass spectra and retention times with the NIST/EPA/NIH mass-spectral library. We detected, identified, and relatively quantified more than 106 lipid molecular species including fatty acids, n-alkanes, fatty alcohols, and sterols. Pollen-derived lipids stimulation up-regulate cytokines expression of dendritic and natural killer T cells co-culture. Conclusions/Significance Here we report on a lipidomic analysis of pollen lipids that can serve as a database for identifying potential lipid antigens and/or novel candidate molecules involved in allergy. The database provides a resource that facilitates studies on the role of lipids in the immunopathogenesis of allergy. Pollen

  6. Environmental pollen trapped by tobacco leaf as indicators of the provenance of counterfeit cigarette products: a preliminary investigation and test of concept.

    PubMed

    Donaldson, Margaret P; Stephens, William E

    2010-05-01

    The global trade in counterfeit tobacco products is increasingly taking market share from legal brands in many parts of the developed world, with attendant adverse economic, health, criminal, and other societal impacts. Knowing the geographical source is central to developing new strategies for curbing this illicit trade, and here, the potential of environmental pollen extracted from manufactured cigarettes is examined. Two samples representing U.S. and Chinese brands were investigated for their pollen content. Results indicate that tobacco leaf very efficiently captures environmental pollen (about 1800 and 12,600 grains per cigarette, respectively) with no detectable self-contamination by the tobacco plant. In both cases, the flora is typical of open space environments, but pollen type counts indicate very different distributions of species. This preliminary investigation indicates that palynology has the potential to constrain geographical source(s) of tobacco, particularly if regionally localized species can be recognized among the pollen. PMID:20202071

  7. Arabidopsis FIMBRIN5, an Actin Bundling Factor, Is Required for Pollen Germination and Pollen Tube Growth[W

    PubMed Central

    Wu, Youjun; Yan, Jin; Zhang, Ruihui; Qu, Xiaolu; Ren, Sulin; Chen, Naizhi; Huang, Shanjin

    2010-01-01

    Actin cables in pollen tubes serve as molecular tracks for cytoplasmic streaming and organelle movement and are formed by actin bundling factors like villins and fimbrins. However, the precise mechanisms by which actin cables are generated and maintained remain largely unknown. Fimbrins comprise a family of five members in Arabidopsis thaliana. Here, we characterized a fimbrin isoform, Arabidopsis FIMBRIN5 (FIM5). Our results show that FIM5 is required for the organization of actin cytoskeleton in pollen grains and pollen tubes, and FIM5 loss-of-function associates with a delay of pollen germination and inhibition of pollen tube growth. FIM5 decorates actin filaments throughout pollen grains and tubes. Actin filaments become redistributed in fim5 pollen grains and disorganized in fim5 pollen tubes. Specifically, actin cables protrude into the extreme tips, and their longitudinal arrangement is disrupted in the shank of fim5 pollen tubes. Consequently, the pattern and velocity of cytoplasmic streaming were altered in fim5 pollen tubes. Additionally, loss of FIM5 function rendered pollen germination and tube growth hypersensitive to the actin-depolymerizing drug latrunculin B. In vitro biochemical analyses indicated that FIM5 exhibits actin bundling activity and stabilizes actin filaments. Thus, we propose that FIM5 regulates actin dynamics and organization during pollen germination and tube growth via stabilizing actin filaments and organizing them into higher-order structures. PMID:21098731

  8. Methods to isolate a large amount of generative cells, sperm cells and vegetative nuclei from tomato pollen for “omics” analysis

    PubMed Central

    Lu, Yunlong; Wei, Liqin; Wang, Tai

    2015-01-01

    The development of sperm cells (SCs) from microspores involves a set of finely regulated molecular and cellular events and the coordination of these events. The mechanisms underlying these events and their interconnections remain a major challenge. Systems analysis of genome-wide molecular networks and functional modules with high-throughput “omics” approaches is crucial for understanding the mechanisms; however, this study is hindered because of the difficulty in isolating a large amount of cells of different types, especially generative cells (GCs), from the pollen. Here, we optimized the conditions of tomato pollen germination and pollen tube growth to allow for long-term growth of pollen tubes in vitro with SCs generated in the tube. Using this culture system, we developed methods for isolating GCs, SCs and vegetative cell nuclei (VN) from just-germinated tomato pollen grains and growing pollen tubes and their purification by Percoll density gradient centrifugation. The purity and viability of isolated GCs and SCs were confirmed by microscopy examination and fluorescein diacetate staining, respectively, and the integrity of VN was confirmed by propidium iodide staining. We could obtain about 1.5 million GCs and 2.0 million SCs each from 180 mg initiated pollen grains, and 10 million VN from 270 mg initiated pollen grains germinated in vitro in each experiment. These methods provide the necessary preconditions for systematic biology studies of SC development and differentiation in higher plants. PMID:26082789

  9. Pollen tetrads in the detection of environmental mutagenesis

    SciTech Connect

    Mulcahy, D.L.

    1981-01-01

    Although pollen is a very sensitive indicator of environmental mutagenesis, it is also sensitive to nonmutagenic environmental stress. By analyzing pollen tetrads, rather than individual pollen grains, it is possible to distinguish between mutagenic and nonmutagenic influences. Another advantage of using pollen tetrads in mutagenicity studies is that it is possible to discriminate between pre- and post-pachytene mutations. This eliminates the mutant sector problem of a single mutational event giving rise to a large number of mutant cells. Methods of analyzing pollen tetrads are described.

  10. Pollen wall development: the associated enzymes and metabolic pathways.

    PubMed

    Jiang, J; Zhang, Z; Cao, J

    2013-03-01

    Pollen grains are surrounded by a sculpted wall, which protects male gametophytes from various environmental stresses and microbial attacks, and also facilitates pollination. Pollen wall development requires lipid and polysaccharide metabolism, and some key genes and proteins that participate in these processes have recently been identified. Here, we summarise the genes and describe their functions during pollen wall development via several metabolic pathways. A working model involving substances and catalytic enzyme reactions that occur during pollen development is also presented. This model provides information on the complete process of pollen wall development with respect to metabolic pathways. PMID:23252839

  11. Extensive Pollen Flow but Few Pollen Donors and High Reproductive Variance in an Extremely Fragmented Landscape

    PubMed Central

    González-Martínez, Santiago C.; Aparicio, Abelardo

    2012-01-01

    Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (Nep) and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73–93%), fat-tailed dispersal kernels and large average pollination distances (δ = 229–412 m). However, they also agreed in detecting very few pollen donors (Nep = 4.3–10.2) and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plant