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Sample records for aborted pollen grains

  1. A simplified method for differential staining of aborted and non-aborted pollen grains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to use chemical staining to discriminate aborted from non-aborted pollen grains has well-known practical applications in agriculture. A commonly used technique for assessing pollen vitality, Alexander’s stain, uses chloral hydrate, phenol and mercuric chloride, all of which are highly to...

  2. 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

  3. 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

  4. Microsporogenesis in the endangered species Cupressus dupreziana A. Camus: evidence for meiotic defects yielding unreduced and abortive pollen.

    PubMed

    El Maâtaoui, M; Pichot, C

    2001-08-01

    To understand the reproductive biology of Cupressus dupreziana A. Camus (Cupressaceae), a highly endangered Mediterranean conifer, the processes of microsporogenesis and pollen differentiation were investigated cytologically. Pre-meiotic development proved to be similar to the coniferous pattern: the microsporangia differentiated sporogenous tissue in which microsporocytes separated and underwent meiosis. As the meiotic steps proceeded, unexpected irregularities were observed concerning chromosomal and nuclear behaviour. This mainly included: abnormal chromosome segregation and cytokinesis, and nuclear fusion of the meiotic products. The result was the formation, in the same microsporangium, of heterogeneous microspore populations arranged in monads, dyads, triads, tetrads, and polyads, and cytoplasts giving rise to pollen grains of different sizes. This indicates that in C. dupreziana both abortive and unreduced pollen grains are generated. The significance of the finding is discussed in relation to reproductive biology and vulnerability to extinction. PMID:11556786

  5. 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

  6. 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

  7. Ultrastructural Study of Some Pollen Grains of Prairie Flowers

    ERIC Educational Resources Information Center

    Kozar, Frank

    1973-01-01

    Discusses the importance of the electron microscope, and in particular the scanning electron microscope, in studying the surface topography, sectional substructures, and patterns of development of pollen grains. The production, dispersal methods, and structure of pollen grains are described and illustrated with numerous electron micrographs. (JR)

  8. Flower numbers, pod production, pollen viability, and pistil function are reduced and flower and pod abortion increased in chickpea (Cicer arietinum L.) under terminal drought

    PubMed Central

    Fang, Xiangwen; Turner, Neil C.; Yan, Guijun; Li, Fengmin; Siddique, Kadambot H. M.

    2010-01-01

    Terminal drought during the reproductive stage is a major constraint to yield of chickpea in many regions of the world. Termination of watering (WS) during podding in a small-seeded desi chickpea (Cicer arietinum L.) cultivar, Rupali, and a large-seeded kabuli chickpea cultivar, Almaz, induced a decrease in predawn leaf water potential (LWP), in the rate of photosynthesis, and in stomatal conductance. Compared to well-watered (WW) controls, the WS treatment reduced flower production by about two-thirds. In the WW treatment, about 15% of the flowers aborted and 42% (Rupali) and 67% (Almaz) of the pods aborted, whereas in the WS treatment 37% and 56% of the flowers aborted and 54% and 73% of the pods aborted, resulting in seed yields of 33% and 15% of the yields in WW plants in Rupali and Almaz, respectively. In vitro pollen viability and germination in Rupali decreased by 50% and 89% in the WS treatment, and pollen germination decreased by 80% in vivo when pollen from a WS plant was placed on a stigma of a WW plant. While about 37% of the germinated pollen tubes from WW plants and 22% from the WS plants reached the ovary in the WW plants, less than 3% of pollen grains reached the ovary when pollen from either WS or WW plants was placed on a stigma of a WS plant. It is concluded that, in addition to pod abortion, flower abortion is an important factor limiting yield in chickpea exposed to terminal drought and that water deficit impaired the function of the pistil/style more than the pollen. PMID:19854801

  9. Foldable structures and the natural design of pollen grains

    PubMed Central

    Katifori, Eleni; Alben, Silas; Cerda, Enrique; Nelson, David R.; Dumais, Jacques

    2010-01-01

    Upon release from the anther, pollen grains of angiosperm flowers are exposed to a dry environment and dehydrate. To survive this process, pollen grains possess a variety of physiological and structural adaptations. Perhaps the most striking of these adaptations is the ability of the pollen wall to fold onto itself to prevent further desiccation. Roger P. Wodehouse coined the term harmomegathy for this folding process in recognition of the critical role it plays in the survival of the pollen grain. There is still, however, no quantitative theory that explains how the structure of the pollen wall contributes to harmomegathy. Here we demonstrate that simple geometrical and mechanical principles explain how wall structure guides pollen grains toward distinct folding pathways. We found that the presence of axially elongated apertures of high compliance is critical for achieving a predictable and reversible folding pattern. Moreover, the intricate sculpturing of the wall assists pollen closure by preventing mirror buckling of the surface. These results constitute quantitative structure-function relationships for pollen harmomegathy and provide a framework to elucidate the functional significance of the very diverse pollen morphologies observed in angiosperms. PMID:20404200

  10. 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

  11. 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

  12. 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.

  13. 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

  14. Comparative Actions of Barbiturates Studied by Pollen Grain Germination.

    ERIC Educational Resources Information Center

    Kordan, Herbert A.; Mumford, Pauline M.

    1979-01-01

    Describes a simple experimental system whereby the comparative actions of long, medium, and short-acting barbiturates can be demonstrated in a relatively short period of time under optical microscopy using pollen grains as the biological test or assay system. (Author/HM)

  15. 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

  16. ABORTED MICROSPORES Acts as a Master Regulator of Pollen Wall Formation in Arabidopsis.

    PubMed

    Xu, Jie; Ding, Zhiwen; Vizcay-Barrena, Gema; Shi, Jianxin; Liang, Wanqi; Yuan, Zheng; Werck-Reichhart, Danièle; Schreiber, Lukas; Wilson, Zoe A; Zhang, Dabing

    2014-04-29

    Mature pollen is covered by durable cell walls, principally composed of sporopollenin, an evolutionary conserved, highly resilient, but not fully characterized, biopolymer of aliphatic and aromatic components. Here, we report that ABORTED MICROSPORES (AMS) acts as a master regulator coordinating pollen wall development and sporopollenin biosynthesis in Arabidopsis thaliana. Genome-wide coexpression analysis revealed 98 candidate genes with specific expression in the anther and 70 that showed reduced expression in ams. Among these 70 members, we showed that AMS can directly regulate 23 genes implicated in callose dissociation, fatty acids elongation, formation of phenolic compounds, and lipidic transport putatively involved in sporopollenin precursor synthesis. Consistently, ams mutants showed defective microspore release, a lack of sporopollenin deposition, and a dramatic reduction in total phenolic compounds and cutin monomers. The functional importance of the AMS pathway was further demonstrated by the observation of impaired pollen wall architecture in plant lines with reduced expression of several AMS targets: the abundant pollen coat protein extracellular lipases (EXL5 and EXL6), and CYP98A8 and CYP98A9, which are enzymes required for the production of phenolic precursors. These findings demonstrate the central role of AMS in coordinating sporopollenin biosynthesis and the secretion of materials for pollen wall patterning. PMID:24781116

  17. The damaging effects of nitrogen ion beam implantation on upland cotton ( Gossypium hirsutum L.) pollen grains

    NASA Astrophysics Data System (ADS)

    Yu, Yanjie; Wu, Lijun; Wu, Yuejin; Wang, Qingya; Tang, Canming

    2008-09-01

    With the aim to study the effects of an ion beam on plant cells, upland cotton (Gossypium hirsutum L.) cultivar "Sumian 22" pollen grains were irradiated in vacuum (7.8 × 10-3 Pa) by low-energy nitrogen ions with an energy of 20 keV at various fluences ranging from 0.26 × 1016 to 0.78 × 1016 N+/cm2. The irradiation effects on pollen grains were tested, considering the ultrastructural changes in the exine and interior walls of pollen grains, their germination rate, the growth speed of the pollen tubes in the style, fertilization and boll development after the pistils were pollinated by the pollen grains which had been implanted with nitrogen ions. Nitrogen ions entered the pollen grains by etching and penetrating the exine and interior walls and destroying cell structures. A greater percentage of the pollen grains were destroyed as the fluence of N+ ions increased. Obviously, the nitrogen ion beam penetrated the exine and interior walls of the pollen grains and produced holes of different sizes. As the ion fluence increased, the amount and the density of pollen grain inclusions decreased and the size of the lacuna and starch granules increased. Pollen grain germination rates decreased with increasing ion fluence. The number of pollen tubes in the style declined with increased ion implantation into pollen grains, but the growth speed of the tubes did not change. All of the pollen tubes reached the end of the style at 13 h after pollination. This result was consistent with that of the control. Also, the weight and the diameter of the ovary decreased and shortened with increased ion beam implantation fluence. No evident change in the fecundation time of the ovule was observed. These results indicate that nitrogen ions can enter pollen grains and cause a series of biological changes in pollen grains of upland cotton.

  18. A high-throughput procedure for single pollen grain collection and PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollen grains are haploid male gametophytes that share identical genetic contents of the female gametophytes; therefore, one can predict the potential genetic makeup of progeny by genotyping single pollen DNA. Amplification of DNA from single pollen grain using PCR has been accomplished in several ...

  19. High-throughput procedure for single pollen grain collection and polymerase chain reaction in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single pollen grain PCR has succeeded in several species, however only a limited number (up to 60) pollen grains were involved due to difficulties in pollen isolation and lysis. This has limited its application in genetic analysis and mapping studies in plants. A high-throughput procedure for dete...

  20. 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

  1. 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 %.

  2. 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

  3. 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

  4. Silencing of the Tapetum-Specific Zinc Finger Gene TAZ1 Causes Premature Degeneration of Tapetum and Pollen Abortion in Petunia

    PubMed Central

    Kapoor, Sanjay; Kobayashi, Akira; Takatsuji, Hiroshi

    2002-01-01

    TAZ1 (TAPETUM DEVELOPMENT ZINC FINGER PROTEIN1; renamed from PEThy; ZPT3-2) cDNA was first isolated as an anther-specific cDNA from petunia. Here, we report a functional characterization that includes analysis of spatial and temporal expression profiles and examination of anther phenotypes in TAZ1-silenced plants. TAZ1 showed a biphasic expression pattern. In the premeiotic phase, TAZ1 transcripts were found to accumulate in all cell types of the anther except the tapetum and gametophytic tissues, whereas the postmeiotic phase of anther development was characterized by expression exclusively in the tapetum. Silencing of TAZ1 by cosuppression resulted in aberrant development and precocious degeneration of the tapetum, followed by extensive microspore abortion that started soon after their release from pollen tetrads. A few pollen grains that survived showed reduced flavonol accumulation, defects in pollen wall formation, and poor germination rates. This study demonstrates an essential role for TAZ1 in the postmeiotic phase of tapetum development. PMID:12368491

  5. 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

  6. Abortion

    MedlinePlus

    An abortion is a procedure to end a pregnancy. It uses medicine or surgery to remove the embryo or ... personal. If you are thinking of having an abortion, most healthcare providers advise counseling.

  7. Abortion.

    PubMed

    1993-09-01

    Vacuum aspiration, dilatation and curettage, hysterotomy, and, in some cases, hysterectomy comprise surgical methods of abortion. Oral administration of RU-486, epostane, prostaglandins E and F2 and vaginal suppositories of prostaglandins E and F2 are medical abortion methods. The traditional or clandestine methods are usually performed by unqualified persons and pregnant women themselves. These methods tend to be inefficient and harmful. They include oral preparations of herbs and drugs (e.g., quinine and ergot), introduction of fluids (e.g., household disinfectants) into the vagina, introduction of foreign bodies (e.g., twigs, stems, hollow tubes, needles, wire) into the uterus. Hospital records, death certificates, and community-based surveys are common sources of data on abortion. Worldwide, 40-70/1000 women of childbearing age undergo an abortion. 20-33% of all pregnancies are terminated. Abortion is always legal when it is performed to save a pregnant woman's life. In most countries, it is legal to protect the woman's physical or mental health against serious danger. The risk of death from a legal abortion is rare. On the other hand, when an abortion is performed by an unqualified, unskilled abortionist and/or under unhygienic conditions (all of which are common in countries who have a law against abortion) the risk of death is much higher. In fact, abortion is one of the leading causes of maternal death in many countries (25% and 86% of maternal deaths in Bangladesh and Romania, respectively). Common complications of abortion are incomplete abortion, trauma to pelvic organs (e.g., uterine perforation), tetanus, and infertility. In some developing countries, the cost of treating abortion complications account for up to 50% of maternity hospital budgets. Ways to reduce mortality from unsafe abortion include promoting contraceptive use, legalizing abortion, allowing trained practitioners to perform abortions for health reasons, and improving clinical management

  8. Comparison of ultrastructure, pollen tube growth pattern and starch content in developing and abortive ovaries during the progamic phase in hazel

    PubMed Central

    Liu, Jianfeng; Zhang, Huidi; Cheng, Yunqing; Wang, Ju; Zhao, Yixin; Geng, Wanting

    2014-01-01

    HIGHLIGHTS In an abortive ovary of hazel, an integument seldom differentiated and a mature embryo sac never developed.In an abortive ovary of hazel, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded.Ovary abortion in the four hybrid cultivars was indicated to be associated with insufficient resource availability to support fruit set by all flowers, whereas ovary abortion in C. heterophylla was at least partly determined by pollen availability. In Northeast China, a high frequency of ovary abortion contributes to serious losses in yield of hazelnut. The development of pistillate inflorescences and fruit clusters of four large-fruited hybrid hazel cultivars and the small-fruited Corylus heterophylla were used to study ovary abortion and its possible causes during the progamic phase in hazel. The average number of pistillate (ANP) flowers per inflorescence and average number of fruit (ANF) per cluster of four hybrid hazel cultivars were 7.6–8.5 and 2.4–3.0 respectively; in C. heterophylla, its ANP and ANF was 5.8–6.2 and 3.5, respectively. The total drop varied from 50 to 67%. Ovary abortion in hazel initiated from about 30 days after blooming. The percentage of abortive ovaries (PAO) in the four hybrid hazel cultivars ranged from 63 to 72%, and was significantly higher than that of C. heterophylla (29–42%). Only the abortive ovary ratio of C. heterophylla was significantly reduced after artificial pollination. Fruit number per cluster was positively and negatively correlated with yield and nut mass, respectively. In abortive ovaries, the diameter remained less than 2 mm during the entire fruit development, an integument seldom differentiated and a mature embryo sac never developed. In addition, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded. Compared with abortive ovary, starch content in developing ovary

  9. Comparison of ultrastructure, pollen tube growth pattern and starch content in developing and abortive ovaries during the progamic phase in hazel.

    PubMed

    Liu, Jianfeng; Zhang, Huidi; Cheng, Yunqing; Wang, Ju; Zhao, Yixin; Geng, Wanting

    2014-01-01

    HIGHLIGHTSIn an abortive ovary of hazel, an integument seldom differentiated and a mature embryo sac never developed.In an abortive ovary of hazel, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded.Ovary abortion in the four hybrid cultivars was indicated to be associated with insufficient resource availability to support fruit set by all flowers, whereas ovary abortion in C. heterophylla was at least partly determined by pollen availability. In Northeast China, a high frequency of ovary abortion contributes to serious losses in yield of hazelnut. The development of pistillate inflorescences and fruit clusters of four large-fruited hybrid hazel cultivars and the small-fruited Corylus heterophylla were used to study ovary abortion and its possible causes during the progamic phase in hazel. The average number of pistillate (ANP) flowers per inflorescence and average number of fruit (ANF) per cluster of four hybrid hazel cultivars were 7.6-8.5 and 2.4-3.0 respectively; in C. heterophylla, its ANP and ANF was 5.8-6.2 and 3.5, respectively. The total drop varied from 50 to 67%. Ovary abortion in hazel initiated from about 30 days after blooming. The percentage of abortive ovaries (PAO) in the four hybrid hazel cultivars ranged from 63 to 72%, and was significantly higher than that of C. heterophylla (29-42%). Only the abortive ovary ratio of C. heterophylla was significantly reduced after artificial pollination. Fruit number per cluster was positively and negatively correlated with yield and nut mass, respectively. In abortive ovaries, the diameter remained less than 2 mm during the entire fruit development, an integument seldom differentiated and a mature embryo sac never developed. In addition, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded. Compared with abortive ovary, starch content in developing ovary of four

  10. [Abortion].

    PubMed

    Dourlen-rollier, A M

    1971-01-01

    The historical and current (1969) abortion laws in France as well as those in other Western countries are analyzed. France has had a series of punitive abortion codes since the Napoleonic Code of 1810 prescribing solitary confinement for the woman. The reforms of 1920 and 1923 made provocation of abortion or contraceptional propaganda a "crime" (felony), later a "delit" (misdemeanor), called for trial before magistr ate instead of jury, but resulted in only about 200 convictions a year. The decree of 1939 extended the misdemeanor to women who aborted even if they were not pregnant, and provided for professional licenses such as that of surgeon or pharmacist to be suspended. The law of 1942 made abortion a social crime and increased the maximum penalty to capital punishment, which was exercised in 2 cases. About 4000 per year were convicted from 1942-1944. Now the law still applies to all who intend to abort, whether or not pregnant or successful, but punishemnt is limited to 1-5 years imprisonment, and 72,000 francs fine, or suspension of medical practice for 5 years. About 500 have been convicted per year. Since 1955 legal abortion has been available (to about 130 women over 4 years) if it is the only means to save the woman's life. Although pregnancy tests are controlled, the population desregards the law by resorting to clandestine abortion. The wealthy travel to Switzerland (where 68% of legal abortions are done on French women) or to England. Numbers are estimated by the French government at 250,000-300,000 per year, or 1 for every 2 live births, but by hospital statistics at 400,000-1,000,000 per year. The rest of the review covers abortion laws in Scandinavian, Central European, and individual US states as of 1969. PMID:12333138

  11. 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.

  12. 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

  13. Classification of bee pollen grains using hyperspectral microscopy imaging and Fisher linear classifier

    NASA Astrophysics Data System (ADS)

    Su, Kang; Zhu, Siqi; Wei, Lin; Li, Zhen; Yin, Hao; Ye, Pingping; Li, Anming; Chen, Zhenqiang; Li, Migao

    2016-05-01

    The rapid and accurate classification of bee pollen grains is still a challenge. The purpose of this paper is to develop a method which could directly classify bee pollen grains based on fluorescence spectra. Bee pollen grain samples of six species were excited by a 409-nm laser diode source, and their fluorescence images were acquired by a hyperspectral microscopy imaging (HMI) system. One hundred pixels in the region of interest were randomly selected from each single bee pollen species. The fluorescence spectral information in all the selected pixels was stored in an n-dimensional hyperspectral data set, where n=37 for a total of 37 hyperspectral bands (465 to 645 nm). The hyperspectral data set was classified using a Fisher linear classifier. The performance of the Fisher linear classifier was measured by the leave-one-out cross-validation method, which yielded an overall accuracy of 89.2%. Finally, additional blinded samples were used to evaluate the established classification model, which demonstrated that bee pollen mixtures could be classified efficiently with the HMI system.

  14. The Epidermal Cell Structure of the Secondary Pollen Presenter in Vangueria infausta (Rubiaceae: Vanguerieae) Suggests a Functional Association with Protruding Onci in Pollen Grains

    PubMed Central

    Tilney, Patricia M.; van Wyk, Abraham E.; van der Merwe, Chris F.

    2014-01-01

    Secondary pollen presentation is a well-known phenomenon in the Rubiaceae with particularly conspicuous pollen presenters occurring in the tribe Vanguerieae. These knob-like structures are formed by a modification of the upper portion of the style and stigma, together known as the stylar head complex. In the flower bud and shortly before anthesis, the anthers surrounding the stylar head complex dehisce and release pollen grains which adhere to the pollen presenter. The epidermal cells of the pollen presenter facing the anthers are radially elongated with a characteristic wall thickening encircling the anticlinal walls of each cell towards the distal end. These cells were studied in the pollen presenter of Vangueria infausta using electron and light microscopy in conjunction with histochemical tests and immunohistochemical methods. Other prominent thickenings of the cell wall were also observed on the distal and proximal walls. All these thickenings were found to be rich in pectin and possibly xyloglucan. The terms “thickenings of Igersheim” and “bands of Igersheim” are proposed to refer, respectively, to these wall structures in general and those encircling the anticlinal walls of each cell near the distal end. The epidermal cells have an intricate ultrastructure with an abundance of organelles, including smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and secretory vesicles. This indicates that these cells are likely to have an active physiological role. The pollen grains possess prominent protruding onci and observations were made on their structure and development. Walls of the protruding onci are also rich in pectin. Pectins are hydrophilic and known to be involved in the dehydration and rehydration of pollen grains. We hypothesise that the thickenings of Igersheim, as well as the protruding onci of the pollen grains, are functionally associated and part of the adaptive syndrome of secondary pollen presentation, at least in the

  15. The epidermal cell structure of the secondary pollen presenter in Vangueria infausta (Rubiaceae: Vanguerieae) suggests a functional association with protruding onci in pollen grains.

    PubMed

    Tilney, Patricia M; van Wyk, Abraham E; van der Merwe, Chris F

    2014-01-01

    Secondary pollen presentation is a well-known phenomenon in the Rubiaceae with particularly conspicuous pollen presenters occurring in the tribe Vanguerieae. These knob-like structures are formed by a modification of the upper portion of the style and stigma, together known as the stylar head complex. In the flower bud and shortly before anthesis, the anthers surrounding the stylar head complex dehisce and release pollen grains which adhere to the pollen presenter. The epidermal cells of the pollen presenter facing the anthers are radially elongated with a characteristic wall thickening encircling the anticlinal walls of each cell towards the distal end. These cells were studied in the pollen presenter of Vangueria infausta using electron and light microscopy in conjunction with histochemical tests and immunohistochemical methods. Other prominent thickenings of the cell wall were also observed on the distal and proximal walls. All these thickenings were found to be rich in pectin and possibly xyloglucan. The terms "thickenings of Igersheim" and "bands of Igersheim" are proposed to refer, respectively, to these wall structures in general and those encircling the anticlinal walls of each cell near the distal end. The epidermal cells have an intricate ultrastructure with an abundance of organelles, including smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and secretory vesicles. This indicates that these cells are likely to have an active physiological role. The pollen grains possess prominent protruding onci and observations were made on their structure and development. Walls of the protruding onci are also rich in pectin. Pectins are hydrophilic and known to be involved in the dehydration and rehydration of pollen grains. We hypothesise that the thickenings of Igersheim, as well as the protruding onci of the pollen grains, are functionally associated and part of the adaptive syndrome of secondary pollen presentation, at least in the Vanguerieae

  16. Evaluation of anti-inflammatory activity of Typha angustifolia pollen grains extracts in experimental animals

    PubMed Central

    Varpe, Saroj S.; Juvekar, Archana R.; Bidikar, Mukta P.; Juvekar, Parikshit R.

    2012-01-01

    Objective: This study was designed to evaluate the anti-inflammatory activity of aqueous and 70% methanolic extracts of pollen grains of Typha angustifolia. Materials and Methods: Female Sprague Dawley rats were used for the study. The acute anti-inflammatory activity of pollen grains of T. angustifolia was studied using the carrageenan as phlogistic agent, whereas its chronic anti-inflammatory effect was investigated by the percentage inhibition of cotton pellet-induced granuloma. Results: Both aqueous and 70% methanolic extracts of pollen grains of T. angustifolia showed significant dose-dependent inhibition of carrageenan-induced paw edema as compared to the control (P<0.001). It was observed that both the extracts at dose of 125 mg/kg inhibited the granuloma formation by 44.30% which is higher than at dose of 500, 250 mg/kg, thus causing a significant (P<0.001) non-dose-related inhibition of granuloma formation. Conclusion: The results of this study indicate that extracts of pollen grains of T. angustifolia are effective in the treatment of both acute and chronic inflammatory conditions and thus support its traditional utilization. PMID:23248413

  17. Abortion.

    PubMed

    Blumenthal, P D

    1991-08-01

    In 1990 abortion literature was characterized by articles relating to 1) the safety of surgical abortion procedures, 2) advances in knowledge and experience with medical abortifacients such as mifepristone (RU 486), and 3) reviews of psychologic and ethical considerations. Although technical methods differ greatly between countries and continents, there is increasing similarity between termination protocols in the United States, the United Kingdom, and Europe. The advent of mifepristone will make this even more so. Surgically, although dilatation and evacuation procedures are far more common in the United States than in other countries, the literature reflects a fine-tuning of analysis and technique, with safety the major consideration. Knowledge about the effectiveness of mifepristone continues to grow, and the effective dose for early first-trimester termination appears established. There is increasing evidence that at least in the short term, the negative psychologic sequelae of abortion are infrequent and are inconsequential as a public health issue. PMID:1878507

  18. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths

    PubMed Central

    Holst, Irene; Moreno, J. Enrique; Piperno, Dolores R.

    2007-01-01

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals. PMID:17978176

  19. Epigenetic marks in the Hyacinthus orientalis L. mature pollen grain and during in vitro pollen tube growth.

    PubMed

    Kozłowska, Marlena; Niedojadło, Katarzyna; Brzostek, Marta; Bednarska-Kozakiewicz, Elżbieta

    2016-09-01

    During the sexual reproduction of flowering plants, epigenetic control of gene expression and genome integrity by DNA methylation and histone modifications plays an important role in male gametogenesis. In this study, we compared the chromatin modification patterns of the generative, sperm cells and vegetative nuclei during Hyacinthus orientalis male gametophyte development. Changes in the spatial and temporal distribution of 5-methylcytosine, acetylated histone H4 and histone deacetylase indicated potential differences in the specific epigenetic state of all analysed cells, in both the mature cellular pollen grains and the in vitro growing pollen tubes. Interestingly, we observed unique localization of chromatin modifications in the area of the generative and the vegetative nuclei located near each other in the male germ unit, indicating the precise mechanisms of gene expression regulation in this region. We discuss the differences in the patterns of the epigenetic marks along with our previous reports of nuclear metabolism and changes in chromatin organization and activity in hyacinth male gametophyte cells. We also propose that this epigenetic status of the analysed nuclei is related to the different acquired fates and biological functions of these cells. PMID:27422435

  20. Abortion.

    PubMed

    Savage, A

    1979-09-15

    I refer for termination anyone who requests it for--pace Mr V Tunkel, (28 July, p 253)--the law is generally regarded as being one of "abortion on demand." I have some misgivings as I do not believe that women in early pregnancy are always in a fit state to make a considered decision, and they cannot in the nature of things be given time. I have, however, become increasingly worried about the morbidity arising from the procedure, and it is interesting that letters on the subject (25 August, pp 495 and 496) should be followed by one reporting rupture of the uterus during prostaglandin-induced abortion--yet another complication to add to those of cervical incompetence, pelvic sepsis, and permanent neurological damage. In so far as these tragedies usually follow late terminations Mr John Corrie's Bill is to be welcomed. A few further points. I am not so cynical as to think that every impregnation is the result of a thoughtless act of male lust. Unlike Professor Peter Huntingford (25 August, p 496), I listen to men as well as women, and many of them are deeply involved emotionally in the pregnancy they have helped to produce. Certainly I think a man should have the right to be consulted if his wife is to undergo a procedure that might damage her health. It is unfair contemptuously to dismiss as "whims" opinions that differ from ones own. These may result from genuine conscientious doubts or inability to cope from overwork and understaffing. Abortion is quite the most expensive form of contraception, and perhaps in these days of financial stringency this should be taken into account. "Bigotry" is defined in my dictionary as "blind zeal." This could be said of those who enthusiastically promote a course of action without regard to circumstances, safety, or cost. PMID:497770

  1. Mitochondrial ORF79 levels determine pollen abortion in cytoplasmic male sterile rice.

    PubMed

    Kazama, Tomohiko; Itabashi, Etsuko; Fujii, Shinya; Nakamura, Takahiro; Toriyama, Kinya

    2016-03-01

    Cytoplasmic male sterility (CMS) is an important agricultural trait characterized by lack of functional pollen, and caused by ectopic and defective mitochondrial gene expression. The pollen function in CMS plants is restored by the presence of nuclear-encoded restorer of fertility (Rf) genes. Previously, we cloned Rf2, which restores the fertility of Lead Rice (LD)-type CMS rice. However, neither the function of Rf2 nor the identity of the mitochondrial gene causing CMS has been determined in LD-CMS rice. Here, we show that the mitochondrial gene orf79 acts as a CMS-associated gene in LD-CMS rice, similar to its role in BT-CMS rice originating from Chinsurah Boro II, and Rf2 weakly restores fertility in BT-CMS rice. We also show that RF2 promotes degradation of atp6-orf79 RNA in a different manner from that of RF1, which is the Rf gene product in BT-CMS rice. The amount of ORF79 protein in LD-CMS rice was one-twentieth of the amount in BT-CMS rice. The difference in ORF79 protein levels probably accounts for the mild and severe pollen defects in LD-CMS and BT-CMS rice, respectively. In the presence of Rf2, accumulation of ORF79 was reduced to almost zero and 25% in LD-CMS and BT-CMS rice, respectively, which probably accounts for the complete and weak fertility restoration abilities of Rf2 in LD-CMS and BT-CMS rice, respectively. These observations indicate that the amount of ORF79 influences the pollen fertility in two strains of rice in which CMS is induced by orf79. PMID:26850149

  2. 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

  3. 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

  4. Using pollen grains as novel hydrophilic solid-phase extraction sorbents for the simultaneous determination of 16 plant growth regulators.

    PubMed

    Lu, Qian; Wu, Jian-Hong; Yu, Qiong-Wei; Feng, Yu-Qi

    2014-11-01

    In this article, pollen grains were for the first time used as a hydrophilic solid-phase extraction (HILIC-SPE) sorbent for the determination of 16 plant growth regulators (PGRs) in fruits and vegetables. Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM) and nitrogen sorption porosimetry (NSP) were used to investigate the chemical structure and the surface properties of the pollen grains. Pollen grains exhibited an excellent adsorption capacity for some polar compounds due to their particular functional groups. Several parameters influencing extraction performance were investigated. A green and simple HILIC-SPE-method using pollen grain cartridge for purification of fruit and vegetable extractions, followed by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) was established. Good linear relationships were obtained for 16 PGRs with correlation coefficients (R) above 0.9980. The limits of detection (LODs) of 16 PGRs in cucumber were in the range of 0.01-1.10 μg · kg(-1). Reproducibility of the method was evaluated by intra-day and inter-day precisions with relative standard deviations (RSDs), which were less than 14.4%. We successfully applied this methodology to analyze 16 PGRs in 8 different kinds of fruits and vegetables. The recoveries from samples spiked with 16 PGRs were from 80.5% to 119.2%, with relative standard deviations less than 15.0%. PMID:25311486

  5. A Comparison of the Human Buccal Cell Assay and the Pollen Abortion Assay in Assessing Genotoxicity in an Urban-Rural Gradient

    PubMed Central

    Fleck, Alan da Silveira; Vieira, Mariana; Amantéa, Sergio Luís; Rhoden, Claudia Ramos

    2014-01-01

    Air pollution is exacerbated near heavy traffic roads in cities. Air pollution concentration and composition vary by region and depend on urban-rural gradients. The aim of this study was to evaluate the distribution of air pollution in areas of varying population densities and to compare plant biomonitoring with an established biomarker of human exposure to traffic-related air pollution in children. The areas of study were selected near a major street in 3 different regions. Areas A, B and C represent high, intermediate and low population densities, respectively. Micronucleus assay, an established biomarker of human exposure, was performed in children from these areas. For a plant biomonitoring assay, the pollen abortion assay was performed on Bauhinia variegata in these areas. NO2 and O3 concentrations were determined by passive sampling. We report here that the pollen abortion frequency in Bauhinia variegata is correlated with NO2 concentration (P = 0.004) and is strongly associated with vehicular flow and population density in the studied areas. Micronuclei frequency in buccal cells of children was higher in the regions with more degree of urbanization (P < 0.001) following the same pattern of O3 concentrations (P = 0.030). In conclusion, our results demonstrate that high concentrations of air pollutants in Porto Alegre are related to both human and plant genotoxicity. Areas with different concentration of pollutants demonstrated to have an urbanization gradient dependent pattern which also reflected on genotoxic damage among these areas. PMID:25166920

  6. A comparison of the human buccal cell assay and the pollen abortion assay in assessing genotoxicity in an urban-rural gradient.

    PubMed

    Fleck, Alan da Silveira; Vieira, Mariana; Amantéa, Sergio Luís; Rhoden, Claudia Ramos

    2014-09-01

    Air pollution is exacerbated near heavy traffic roads in cities. Air pollution concentration and composition vary by region and depend on urban-rural gradients. The aim of this study was to evaluate the distribution of air pollution in areas of varying population densities and to compare plant biomonitoring with an established biomarker of human exposure to traffic-related air pollution in children. The areas of study were selected near a major street in 3 different regions. Areas A, B and C represent high, intermediate and low population densities, respectively. Micronucleus assay, an established biomarker of human exposure, was performed in children from these areas. For a plant biomonitoring assay, the pollen abortion assay was performed on Bauhinia variegata in these areas. NO2 and O3 concentrations were determined by passive sampling. We report here that the pollen abortion frequency in Bauhinia variegata is correlated with NO2 concentration (P = 0.004) and is strongly associated with vehicular flow and population density in the studied areas. Micronuclei frequency in buccal cells of children was higher in the regions with more degree of urbanization (P < 0.001) following the same pattern of O3 concentrations (P = 0.030). In conclusion, our results demonstrate that high concentrations of air pollutants in Porto Alegre are related to both human and plant genotoxicity. Areas with different concentration of pollutants demonstrated to have an urbanization gradient dependent pattern which also reflected on genotoxic damage among these areas. PMID:25166920

  7. Buzz pollination in eight bumblebee-pollinated Pedicularis species: does it involve vibration-induced triboelectric charging of pollen grains?

    PubMed Central

    Corbet, Sarah A.; Huang, Shuang-Quan

    2014-01-01

    Background and Aims Buzz pollination involves explosive pollen release in response to vibration, usually by bees. The mechanism of pollen release is poorly understood, and it is not clear which component of vibration (acceleration, frequency, displacement or velocity) is critical; the role of buzz frequency has been particularly controversial. This study proposes a novel hypothesis that explosive pollen release results from vibration-induced triboelectric charging. If it does, pollen release is expected to depend on achievement of a critical threshold velocity. Methods Eight sympatric buzz-pollinated species of Pedicularis that share bumblebee pollinator species were studied, giving a rare opportunity to compare sonication behaviour of a shared pollinator on different plant species. Key Results Reconsidering previous experimental studies, it is argued that they establish the critical role of the velocity component of vibration in pollen release, and that when displacement is constrained by body size bees can achieve the critical velocity by adjusting frequency. It was shown that workers of Bombus friseanus assorted themselves among Pedicularis species by body size, and that bees adjusted their buzz/wingbeat frequency ratio, which is taken as an index of the velocity component, to a value that corresponds with the galea length and pollen grain volume of each species of Pedicularis. Conclusions Sonication behaviour of B. friseanus differs among Pedicularis species, not only because worker bees assort themselves among plant species by body size, but also because bees of a given size adjust the buzz frequency to achieve a vibration velocity corresponding to the floral traits of each plant species. These findings, and the floral traits that characterize these and other buzz-pollinated species, are compatible with the hypothesis of vibration-induced triboelectric charging of pollen grains. PMID:25274550

  8. Le δ13C des grains de pollen : intérêt pour l'étude des paléovégétationsCarbon isotopic ratios of pollen: interest for palaeovegetations reconstructions

    NASA Astrophysics Data System (ADS)

    Descolas-Gros, Chantal; Calleja, Michel; Cour, Pierre; Richard, Paul; Perruchietti, Christiane; Jame, Patrick

    2001-06-01

    δ13C values of pollen grains belonging to different plant species (trees, herbaceous no poaceae, poaceae) were measured. Most of these temperate species are C3 plants with δ13C values between -28.6 ‰ and -21.7 ‰, the C4 plants have more positive values between -15.9 ‰ and -10 ‰. These results corroborate the interest of such measurements to differentiate C4 poaceae from C3 ones. Inside the same genus or the same species data variability is studied. Chemical treatment (acetolysis) of pollen grains induces a lowering of the values. These preliminary results are intended to help calibrate the pollen grains δ13C of modern plants in order to use δ13C of fossil pollen grains to reconstruct palaeovegetation variability responses to climatic factors.

  9. Factors affecting quantity of pollen dispersal of spray cut chrysanthemum (Chrysanthemum morifolium)

    PubMed Central

    2014-01-01

    Background Spray cut chrysanthemum is a vital flower with high ornamental value and popularity in the world. However, the excessive quantity of pollen dispersal of most spray cut chrysanthemum is an adverse factor during its flowering stage, and can significantly reduce its ornamental value and quickly shorten its vase life. More seriously, excessive pollen grains in the air are usually harmful to people, especially for those with pollen allergies. Therefore, in order to obtain some valuable information for developing spray cut chrysanthemum with less-dispersed or non-dispersed pollen in the future breeding programs, we here investigated the factors affecting quantity of pollen dispersal of spray cut chrysanthemum with four cultivars, i.e. ‘Qx-097’, ‘Noa’, ‘Qx-115’, and ‘Kingfisher’, that have different quantity of pollen dispersal. Results ‘Qx-097’ with high quantity of pollen dispersal has 819 pollen grains per anther, 196.4 disk florets per inflorescence and over 800,000 pollen grains per inflorescence. The corresponding data for ‘Noa’ with low quantity of pollen dispersal are 406, 175.4 and over 350,000, respectively; and 219, 144.2 and nearly 160,000 for ‘Qx-115’ without pollen dispersal, respectively. ‘Kingfisher’ without pollen dispersal has 202.8 disk florets per inflorescence, but its anther has no pollen grains. In addition, ‘Qx-097’ has a very high degree of anther cracking that nearly causes a complete dispersal of pollen grains from its anthers. ‘Noa’ has a moderate degree of anther cracking, and pollen grains in its anthers are not completely dispersed. However, the anthers of ‘Qx-115’ and ‘Kingfisher’ do not crack at all. Furthermore, microsporogenesis and pollen development are normal in ‘Qx-097’, whereas many microspores or pollen degenerate in ‘Noa’, most of them abort in ‘Qx-115’, and all of them degrade in ‘Kingfisher’. Conclusions These results suggest that quantity of pollen

  10. 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

  11. 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

  12. Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n = 28) of Ranunculus laetus Wall. ex Royle

    PubMed Central

    Kumar, Puneet; Singhal, Vijay Kumar

    2012-01-01

    Two accessions were studied for male meiosis in Ranunculus laetus from the cold regions of Northwest Himalayas. One accession showed the presence of 14 bivalents at diakinesis and regular segregation of bivalents at anaphase I which lead to normal tetrad formation with four n microspores and consequently n pollen grains and 100% pollen fertility. Second accession from the same locality revealed the erratic meiosis characterized by the presence of all the 28 chromosomes as univalents in meiocytes at metaphase I. Univalent chromosomes failed to segregate during anaphases and produced restitution nuclei at meiosis I and II. These restitution nuclei resulted into dyads and triads which subsequently produced two types of apparently fertile pollen grains. On the basis of size, the two types of pollen grains were categorized as n (normal reduced) and 2n (unreduced, 1.5-times larger than the n pollen grains). The estimated frequency of 2n pollen grains from dyads and triads (61.59%) was almost the same as that of the observed one (59.90%), which indicated that 2n pollen grains in R. laetus were the result of dyads and triads. The present paper herein may provide an insight into the mechanisms of the formation of various intraspecific polyploids through sexual polyploidization in R. laetus. PMID:22629184

  13. Pollen grain morphology of Fabaceae in the Special Protection Area (SPA) Pau-de-Fruta, Diamantina, Minas Gerais, Brazil.

    PubMed

    Luz, Cynthia F P da; Maki, Erica S; Horák-Terra, Ingrid; Vidal-Torrado, Pablo; Mendonça Filho, Carlos Victor

    2013-01-01

    The presented paper considered the pollen morphology of thirteen species belonging to seven genera of the Fabaceae family occurring in the Pau-de-Fruta Special Protection Area (SPA), Diamantina, state of Minas Gerais, Brazil. The pollen grains of six species of Chamaecrista [C. cathartica (Mart.) H.S. Irwin & Barneby, C. debilis Vogel, C. flexuosa (L.) Greene, C. hedysaroides (Vogel) H.S. Irwin & Barneby, C. glandulosa (L.) Greene, and C. papillata H.S. Irwin & Barneby] have a similar morphology, characterized by three long colporated apertures with a central constriction. The species share specific morphological features regarding pollen size, endoaperture type (circular, lalongate or lolongate) and SEM ornamentation patterns of the exine (rugulate with perforations or perforate). Andira fraxinifolia Benth., Dalbergia miscolobium Benth, Galactia martii DC, Periandra mediterranea (Vell.) Taub., Senna rugosa (G.Don) H.S. Irwin & Barneby and Zornia diphylla (L.) Pers showed different pollen types in small to large size; oblate spheroidal to prolate form; colpus or colporus apertures; circular, lalongate or lolongate endoapertures and distinctive SEM ornamentation patterns of the exine (perforate, microreticulate, reticulate or rugulate with perforations). Only Stryphnodendron adstringens (Mart.) Coville presents polyads. The pollen morphology variation of these species allowed the Fabaceae family to be characterized as eurypalynous in the SPA Pau-de-Fruta. PMID:24346795

  14. 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

  15. RUPTURED POLLEN GRAIN1, a Member of the MtN3/saliva Gene Family, Is Crucial for Exine Pattern Formation and Cell Integrity of Microspores in Arabidopsis1[C][W][OA

    PubMed Central

    Guan, Yue-Feng; Huang, Xue-Yong; Zhu, Jun; Gao, Ju-Fang; Zhang, Hong-Xia; Yang, Zhong-Nan

    2008-01-01

    During microsporogenesis, the microsporocyte (or microspore) plasma membrane plays multiple roles in pollen wall development, including callose secretion, primexine deposition, and exine pattern determination. However, plasma membrane proteins that participate in these processes are still not well known. Here, we report that a new gene, RUPTURED POLLEN GRAIN1 (RPG1), encodes a plasma membrane protein and is required for exine pattern formation of microspores in Arabidopsis (Arabidopsis thaliana). The rpg1 mutant exhibits severely reduced male fertility with an otherwise normal phenotype, which is largely due to the postmeiotic abortion of microspores. Scanning electron microscopy examination showed that exine pattern formation in the mutant is impaired, as sporopollenin is randomly deposited on the pollen surface. Transmission electron microscopy examination further revealed that the primexine formation of mutant microspores is aberrant at the tetrad stage, which leads to defective sporopollenin deposition on microspores and the locule wall. In addition, microspore rupture and cytoplasmic leakage were evident in the rpg1 mutant, which indicates impaired cell integrity of the mutant microspores. RPG1 encodes an MtN3/saliva family protein that is integral to the plasma membrane. In situ hybridization analysis revealed that RPG1 is strongly expressed in microsporocyte (or microspores) and tapetum during male meiosis. The possible role of RPG1 in microsporogenesis is discussed. PMID:18434608

  16. Adsorption of air pollutants on the grain surface of Japanese cedar pollen

    NASA Astrophysics Data System (ADS)

    Okuyama, Yuji; Matsumoto, Kiyoshi; Okochi, Hiroshi; Igawa, Manabu

    The contaminants adsorbed on the surface of pollen may affect the development of hay fever, because the patients of the fever are larger in areas with much air pollution than in nonpolluted areas and the fine particles and gases are susceptible to deposit on the nasal cavities and eyes by their transfer on the pollen. Since Japanese cedar pollinosis is the most common hay fever in Japan, we analyzed the air pollutants adsorbed on the surface of dispersed Japanese cedar pollen in the urban and mountainous districts. Fine anthropogenic particles were significantly adsorbed and many elements were concentrated on the surface of the pollen in the urban site of Yokohama, while they were not concentrated on the surface of the pollen collected at a mountainous site. The acid gases are also adsorbed and acidify the surface, and their amounts increase with their concentrations in the ambient air. The high adsorption of nitric acid on the pollen determined by an exposure experiment of nitric acid gas suggests that nitric acid is dissolved in the inner part of the pollen. The adsorption amounts of the gases on the pollen were especially greater than those on other natural particles, humic acid and yellow sand.

  17. Brassinosteroids promote development of rice pollen grains and seeds by triggering expression of Carbon Starved Anther, a MYB domain protein.

    PubMed

    Zhu, Xiaolei; Liang, Wanqi; Cui, Xiao; Chen, Mingjiao; Yin, Changsong; Luo, Zhijing; Zhu, Jiaying; Lucas, William J; Wang, Zhiyong; Zhang, Dabing

    2015-05-01

    Transport of photoassimilates from leaf tissues (source regions) to the sink organs is essential for plant development. Here, we show that a phytohormone, the brassinosteroids (BRs) promotes pollen and seed development in rice by directly promoting expression of Carbon Starved Anther (CSA) which encodes a MYB domain protein. Over-expression of the BR-synthesis gene D11 or a BR-signaling factor OsBZR1 results in higher sugar accumulation in developing anthers and seeds, as well as higher grain yield compared with control non-transgenic plants. Conversely, knockdown of D11 or OsBZR1 expression causes defective pollen maturation and reduced seed size and weight, with less accumulation of starch in comparison with the control. Mechanically, OsBZR1 directly promotes CSA expression and CSA directly triggers expression of sugar partitioning and metabolic genes during pollen and seed development. These findings provide insight into how BRs enhance plant reproduction and grain yield in an important agricultural crop. PMID:25754973

  18. ATR–FTIR spectroscopy reveals involvement of lipids and proteins of intact pea pollen grains to heat stress tolerance

    PubMed Central

    Lahlali, Rachid; Jiang, Yunfei; Kumar, Saroj; Karunakaran, Chithra; Liu, Xia; Borondics, Ferenc; Hallin, Emil; Bueckert, Rosalind

    2014-01-01

    With climate change, pea will be more frequently subjected to heat stress in semi-arid regions like Saskatchewan during flowering. The pollen germination percentage of two pea cultivars was reduced by heat stress (36°C) with an important decrease in cultivar ‘CDC Golden’ compared to ‘CDC Sage.’ Lipids, protein and other pollen coat compositions of whole intact pollen grains of both pea cultivars were investigated using mid infrared (mid-IR) attenuated total reflectance (ATR)–Fourier transform infrared (FTIR) spectroscopy. Curve fitting of ATR absorbance spectra in the protein region enabled estimation and comparison of different protein secondary structures between the two cultivars. CDC Sage had relatively greater amounts of α-helical structures (48.6–43.6%; band at 1654 cm-1) and smaller amounts of β-sheets (41.3–46%) than CDC Golden. The CDC Golden had higher amounts of β-sheets (46.3–51.7%) compared to α-helical structures (35.3–36.2%). Further, heat stress resulted in prominent changes in the symmetrical and asymmetrical CH2 bands from lipid acyl chain, ester carbonyl band, and carbohydrate region. The intensity of asymmetric and symmetric CH2 vibration of heat stressed CDC Golden was reduced considerably in comparison to the control and the decrease was higher compared to CDC Sage. In addition, CDC Golden showed an increase in intensity at the oxidative band of 3015 cm-1. These results reveal that the whole pollen grains of both pea cultivars responded differently to heat stress. The tolerance of CDC Sage to heat stress (expressed as pollen germination percentage) may be due to its protein richness with α-helical structures which would protect against the destructive effects of dehydration due to heat stress. The low pollen germination percentage of CDC Golden after heat stress may be also due to its sensitivity to lipid changes due to heat stress. PMID:25566312

  19. When did C4 Photosynthesis originate: New evidence from δ13C analysis of single grass-pollen grains

    NASA Astrophysics Data System (ADS)

    Urban, M. A.; Nelson, D. M.; Pearson, A.; Hu, F.

    2009-12-01

    C4 grasses account for >20% of global primary productivity and dominate tropical, subtropical, and warm-temperate grassland ecosystems. Thus it is vital to understand when and why C4 photosynthesis first evolved in the grass family (Poaceae). However, because of limitations of most proxies, the origin of C4 grasses remains ambiguous. Grass pollen is morphologically indistinct below the family level, making pollen analysis a crude instrument for studying C4-grass evolution. Previous studies have investigated the timing of C4 evolution using molecular tools and δ13C records from n-alkanes, ungulate teeth, and paleosols, but they yield disparate results. Molecular clocks suggest that C4 grasses first evolved between 27 and 36 Ma (million years before present), coincident with the Oligocene decline in pCO2 from >1000 to <500 ppm. In contrast, δ13C-based approaches do not detect the presence of C4 grasses until the middle Miocene, indicating that they were previously uncommon or absent on the landscape. To investigate when C4 photosynthesis first appeared in the grass family, we utilized Single Pollen Isotope Ratio AnaLysis (SPIRAL), a technique that reliably distinguishes C4 from C3 grass pollen via δ13C. We analyzed 837 single grains of grass pollen from eight lacustrine geological samples (~100 grains/sample) from France and Spain spanning the earliest Oligocene to middle Miocene. To distinguish C3/C4 ratios, we used an optimal threshold value of -19.2‰ adjusted for small (~1‰) temporal variations in atmospheric δ13C. Initial results provide unequivocal evidence of C4 grass pollen in all samples (24-57% C4 grass pollen ±9.2% on average) lending further credence to the molecular data, which posits that C4 grasses appeared as early as the Late Eocene, which is a plausible outcome when considering alternate schemes of dating phylogenetic trees. A C4 origin prior to pCO2 reaching its lowest levels of the Cenozoic at the Oligocene/Miocene boundary indicates that

  20. Abortion - medical

    MedlinePlus

    Therapeutic medical abortion; Elective medical abortion; Induced abortion; Nonsurgical abortion ... The pregnancy is harmful to the woman's health (therapeutic abortion). The pregnancy resulted after a traumatic event ...

  1. 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 ...

  2. Pollen Grain Size, Density, and Settling Velocity for Palmer Amaranth (Amaranthus palmeri)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Palmer amaranth has known resistance to several herbicides, including glyphosate, and there is concern that the resistance traits are being transferred between spatially segregated populations via pollen movement. The objective of this study was to describe the physical properties of Palmer amarant...

  3. A flash-lamp based device for fluorescence detection and identification of individual pollen grains

    NASA Astrophysics Data System (ADS)

    Kiselev, Denis; Bonacina, Luigi; Wolf, Jean-Pierre

    2013-03-01

    We present a novel optical aerosol particle detector based on Xe flash lamp excitation and spectrally resolved fluorescence acquisition. We demonstrate its performances on three natural pollens acquiring in real-time scattering intensity at two wavelengths, sub-microsecond time-resolved scattering traces of the particles' passage in the focus, and UV-excited fluorescence spectra. We show that the device gives access to a rather specific detection of the bioaerosol particles.

  4. Abortion - surgical

    MedlinePlus

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... problem. Your pregnancy is harmful to your health (therapeutic abortion). The pregnancy resulted after a traumatic event ...

  5. Cytomictic Anomalous Male Meiosis and 2n Pollen Grain Formation in Mertensia echioides Benth. (Boraginaceae) from Kashmir Himalaya

    PubMed Central

    Malik, Reyaz Ahmad; Gupta, Raghbir Chand; Kumari, Santosh; Malik, Akhtar Hussain

    2014-01-01

    Presently Mertensia echioides Benth. (Boraginaceae) collected from Kashmir Himalaya, India, is cytologically analyzed for the first time revealing 2n = 2x = 24 (diploid). Interestingly we found 4.3–6.2% syncytic meiocytes/PMCs with 2n = 4x = 48 (tetraploid) in addition to normal meiocytes (2n = 24) during male meiosis. These comparatively larger PMCs (pollen mother cells) lead to the formation of fertile giant 2n pollen grains. A frequency of 6.4–13.3% PMCs shows transfer of chromatin material at prophase-I and, therefore, results in aneuploid meiocytes. Whole chromatin transfer by the process of cytomixis could also have led to the formation of tetraploid cells. Translocation heterozygosity is also evident in the form of multivalents in 12–17% diploid (2x) meiocytes at diakinesis and metaphase-I and is reported for the first time in this species. The syncytes formed depict open chain hexavalent and quadrivalent formation in the three populations with different frequencies. Moreover chromatin stickiness at metaphase-I is observed in 45% of PMCs in population-1 (P-1). Syncyte or unreduced PMC formation leading to unreduced fertile gametes is here speculated to act as a possible way out for infraspecific polyploidization in the species. PMID:25544950

  6. Abortion - medical

    MedlinePlus

    Therapeutic medical abortion; Elective medical abortion; Induced abortion; Nonsurgical abortion ... A medical, or nonsurgical, abortion can be done within 7 weeks from the first day of the woman's last ...

  7. 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 ...

  8. Can Triticum urartu (Poaceae) be identified by pollen analysis? Implications for detecting the ancestor of the extinct two-grained einkorn-like wheat

    PubMed Central

    López-Merino, Lourdes; Leroy, Suzanne A G; Haldorsen, Sylvi; Heun, Manfred; Reynolds, Alan

    2015-01-01

    The domestication of the one-grained einkorn (Triticum monococcum) in the Near East is relatively well known. However, an independent two-grained einkorn-like domestication has been archaeobotanically detected and scarce information is available. Triticum urartu, a wild wheat, was not fully described until the 1970s because the phenology does not allow it to be distinguished easily from wild einkorn (Triticum boeoticum subsp. thaoudar), although a genetic separation exists. Both species are mostly two grained and could potentially be the relatives of the extinct two-grained form. Pollen grains of several genetically well-identified wheat species, including T. urartu and T. boeoticum subsp. thaoudar, were studied by measuring the grain diameter and examining the exine sculpturing with phase-contrast microscopy and scanning electron microscopy to gain an insight into differences enabling taxonomic identification. This work showed that, although T. urartu pollen is smaller on average, grain diameter is not sufficient because of the size overlap between the species, but T. urartu presents a different exine sculpturing (scabrate) from other Triticum spp. (aerolate). This outcome is useful for taxonomists and archaeobotanists. First, it will allow a simple re-classification of herbarium materials. Second, further research could establish whether T. urartu was cultivated. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177, 278–289. PMID:25821246

  9. Stable Carbon Isotope Ratios of Individual Pollen Grains as a Proxy for C3- Versus C4-Grass Abundance in Paleorecords: A Validation Study

    NASA Astrophysics Data System (ADS)

    Nelson, D. M.; Hu, F.; Pearson, A.

    2007-12-01

    C3 and C4 grasses have distinct influences on major biogeochemical processes and unique responses to important environmental controls. Difficulties in distinguishing between these two functional groups of grasses have hindered paleoecological studies of grass-dominated ecosystems. We recently developed a technique to analyze the stable carbon isotope composition of individual grass-pollen grains using a spooling- wire microcombustion device interfaced with an isotope-ratio mass spectrometer (Nelson et al. 2007). This technique holds promise for improving C3 and C4 grass reconstructions. It requires ~90% fewer grains than typical methods and avoids assumptions associated with mixing models. However, our previous work was based on known C3 and C4 grasses from herbarium specimens and field collections and the technique had not been test using geological samples. To test the ability of this technique to reproduce the abundance of C3 and C4 grasses on the landscape, we measured δ13C values of >1500 individual grains of grass pollen isolated from the surface sediments of 10 North American lakes that span a large gradient of C3 and C4 grass abundance. Results indicate a strong positive correlation (r=0.94) between % C4-grass pollen (derived from classifying δ13C values from single grains as C3 and C4) and the literature-reported abundance of C4 grasses on the landscape. However, the measured % C4-grass pollen shows some deviation from the actual abundance at sites with high proportions of C4 grasses. This is likely caused by uncertainty in the magnitude, composition, and variability of the analytical blank associated with these measurements. Correcting for this deviation using regression analysis improves the estimation of the abundance of C4 grasses on the landscape. Comparison of the % C4-grass pollen with C/N and δ13C measurements of total organic matter in the same lake-sediment samples illustrates the distinct advantage of grass-pollen δ13C as a proxy for

  10. Abortion - surgical

    MedlinePlus

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... Surgical abortion involves dilating the opening to the uterus (cervix) and placing a small suction tube into the uterus. ...

  11. Ca2+ influx into lily pollen grains through a hyperpolarization-activated Ca2+-permeable channel which can be regulated by extracellular CaM.

    PubMed

    Shang, Zhong-lin; Ma, Li-geng; Zhang, Hai-lin; He, Rui-rong; Wang, Xue-chen; Cui, Su-juan; Sun, Da-ye

    2005-04-01

    Confocal laser scanning microscopy (CLSM) and whole-cell patch-clamp were used to investigate the role of Ca2+ influx in maintaining the cytosolic Ca2+ concentration ([Ca2+]c) and the features of the Ca2+ influx pathway in germinating pollen grains of Lilium davidii D. [Ca2+]c decreased when Ca2+ influx was inhibited by EGTA or Ca2+ channel blockers. A hyperpolarization-activated Ca2+-permeable channel, which can be suppressed by trivalent cations, verapamil, nifedipine or diltiazem, was identified on the plasma membrane of pollen protoplasts with whole-cell patch-clamp recording. Calmodulin (CaM) antiserum and W7-agarose, both of which are cell-impermeable CaM antagonists, lead to a [Ca2+]c decrease, while exogenous purified CaM triggers a transient increase of [Ca2+]c and also remarkably activated the hyperpolarization-activated Ca2+ conductance on plasma membrane of pollen protoplasts in a dose-dependent manner. Both the increase of [Ca2+]c and the activation of Ca2+ conductance which were induced by exogenous CaM were inhibited by EGTA or Ca2+ channel blockers. This primary evidence showed the presence of a voltage-dependent Ca2+-permeable channel, whose activity may be regulated by extracellular CaM, in pollen cells. PMID:15695439

  12. 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

  13. Induced Abortion

    MedlinePlus

    ... Induced Abortion Patient Education FAQs Induced Abortion Patient Education Pamphlets - Spanish Induced Abortion FAQ043, May 2015 PDF Format Induced ... Your Practice Patient Safety & Quality Payment Reform (MACRA) Education & Events Annual ... Pamphlets Teen Health About ACOG About Us Leadership & ...

  14. 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 ...

  15. Phosphatidylinositol 4-phosphate 5-kinases 1 and 2 are involved in the regulation of vacuole morphology during Arabidopsis thaliana pollen development.

    PubMed

    Ugalde, José-Manuel; Rodriguez-Furlán, Cecilia; Rycke, Riet De; Norambuena, Lorena; Friml, Jiří; León, Gabriel; Tejos, Ricardo

    2016-09-01

    The pollen grains arise after meiosis of pollen mother cells within the anthers. A series of complex structural changes follows, generating mature pollen grains capable of performing the double fertilization of the female megasporophyte. Several signaling molecules, including hormones and lipids, have been involved in the regulation and appropriate control of pollen development. Phosphatidylinositol 4-phophate 5-kinases (PIP5K), which catalyze the biosynthesis of the phosphoinositide PtdIns(4,5)P2, are important for tip polar growth of root hairs and pollen tubes, embryo development, vegetative plant growth, and responses to the environment. Here, we report a role of PIP5Ks during microgametogenesis. PIP5K1 and PIP5K2 are expressed during early stages of pollen development and their transcriptional activity respond to auxin in pollen grains. Early male gametophytic lethality to certain grade was observed in both pip5k1(-/-) and pip5k2(-/-) single mutants. The number of pip5k mutant alleles is directly related to the frequency of aborted pollen grains suggesting the two genes are involved in the same function. Indeed PIP5K1 and PIP5K2 are functionally redundant since homozygous double mutants did not render viable pollen grains. The loss of function of PIP5K1 and PIP5K2results in defects in vacuole morphology in pollen at the later stages and epidermal root cells. Our results show that PIP5K1, PIP5K2 and phosphoinositide signaling are important cues for early developmental stages and vacuole formation during microgametogenesis. PMID:27457979

  16. 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

  17. The miRNAs and their regulatory networks responsible for pollen abortion in Ogura-CMS Chinese cabbage revealed by high-throughput sequencing of miRNAs, degradomes, and transcriptomes

    PubMed Central

    Wei, Xiaochun; Zhang, Xiaohui; Yao, Qiuju; Yuan, Yuxiang; Li, Xixiang; Wei, Fang; Zhao, Yanyan; Zhang, Qiang; Wang, Zhiyong; Jiang, Wusheng; Zhang, Xiaowei

    2015-01-01

    Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetables in Asia and is cultivated across the world. Ogura-type cytoplasmic male sterility (Ogura-CMS) has been widely used in the hybrid breeding industry for Chinese cabbage and many other cruciferous vegetables. Although, the cause of Ogura-CMS has been localized to the orf138 locus in the mitochondrial genome, however, the mechanism by which nuclear genes respond to the mutation of the mitochondrial orf138 locus is unclear. In this study, a series of whole genome small RNA, degradome and transcriptome analyses were performed on both Ogura-CMS and its maintainer Chinese cabbage buds using deep sequencing technology. A total of 289 known miRNAs derived from 69 families (including 23 new families first reported in B. rapa) and 426 novel miRNAs were identified. Among these novel miRNAs, both 3-p and 5-p miRNAs were detected on the hairpin arms of 138 precursors. Ten known and 49 novel miRNAs were down-regulated, while one known and 27 novel miRNAs were up-regulated in Ogura-CMS buds compared to the fertile plants. Using degradome analysis, a total of 376 mRNAs were identified as targets of 30 known miRNA families and 100 novel miRNAs. A large fraction of the targets were annotated as reproductive development related. Our transcriptome profiling revealed that the expression of the targets was finely tuned by the miRNAs. Two novel miRNAs were identified that were specifically highly expressed in Ogura-CMS buds and sufficiently suppressed two pollen development essential genes: sucrose transporter SUC1 and H+-ATPase 6. These findings provide clues for the contribution of a potential miRNA regulatory network to bud development and pollen engenderation. This study contributes new insights to the communication between the mitochondria and chromosome and takes one step toward filling the gap in the regulatory network from the orf138 locus to pollen abortion in Ogura-CMS plants from a mi

  18. Seasonal variation of IgE and IgG antibody of some atopic patients against the pollen grains of selected plant species.

    PubMed

    Ruffin, J; Shaw, S; Banerjee, S

    1990-01-01

    Several steps were taken to determine the seasonal variation of IgE and IgG antibody against Short Ragweed, Timothy Grass, Tag Alder and White Ash. Extracts of the above pollen grains were separated into their allergen components using SDS-gel electrophoresis and transblotted to nitrocellulose membrane (Western blotting) and probed with sera from atopic patients in every month (August 1987-July 1988). The IgE and IgG antibody against the specific-allergens were detected by double antibody immunoenzyme assay. The percentage of binding was determined by using a 620 video-densitometer. Results indicate that there was no reasonable IgE antibody before the pollination season, but IgEAb appeared after the season and was detectable for several months. Negligible amounts of IgGAb were observed. PMID:2292188

  19. A novel double-component MOAC honeycomb composite with pollen grains as a template for phosphoproteomics research.

    PubMed

    Wang, Jiaxi; Li, Jie; Wang, Yanan; Gao, Mingxia; Zhang, Xiangmin; Deng, Chunhui

    2016-07-01

    The enrichment and separation of phosphopeptides from mixed biological samples is a technologically very significance, but highly challenging work. Current designed materials are mainly based on the broad and effective adsorptive character of metal oxide affinity chromatography (MOAC). Though significant progress has been made in the enrichment of phosphopeptides with MOAC material, there are chances for further development. In this study, a novel pollen-based MOAC honeycomb material was firstly explored in which the suitable hydrophilic channels preferentially enrich much more endogenous phosphopeptides than nonphosphopeptides or proteins while doping binary metal oxides at the atomic level and the ultra-high specific surface area have further allowed it to possess more effective active sites. Based on these unique features, the pollen-based material exhibited high selectivity for β-casein (mass ratio of β-casein/BSA, 1:1500), ultra-low detection limit (0.1fmol), desirable reusability. Moreover, the bionics MOAC composites were investigated in the enrichment of phosphopeptides from nonfat milk, human serum (male and female at the same age) and mice liver, results of which indicate the great potential of the composite for the phosphoproteome analysis of complex biological samples through the cheap and environmentally friendly process. PMID:27154659

  20. 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

  1. [Discussing abortion].

    PubMed

    1997-01-01

    Discussions with several groups of low-income, middle-aged women in various countries of Latin America showed that most disapproved of abortion. In the course of group discussions about the motives of women who seek abortions and the psychological and sanitary conditions under which abortion occurs, however, their disapproval became less categorical. They began to accept the need to decriminalize abortion in order to protect women. The majority, strongly influenced by the Catholic Church, believed that human life begins at conception. Others disapproved of abortion because they feared it would be used as a birth control method and would encourage promiscuity. Most disapproved of abortion for single women attempting to escape family or social censure of unmarried motherhood. Fear of health effects or death from abortion and fear of divine punishment were also mentioned. Recognition of the anguish and pain suffered by women deciding to seek abortion and the difficulty of providing for the material and other needs of many children were factors that led to reconsideration of the wholesale condemnation of abortion. The women realized that such condemnations never take the woman's circumstances into account. Some of the women felt that aborting an unwanted pregnancy would be preferable to abandoning or neglecting an unwanted child. Many of the women came to feel that abortion should be legalized at least under some circumstances. PMID:12348503

  2. The Cysteine Protease CEP1, a Key Executor Involved in Tapetal Programmed Cell Death, Regulates Pollen Development in Arabidopsis[W][OPEN

    PubMed Central

    Zhang, Dandan; Liu, Di; Lv, Xiaomeng; Wang, Ying; Xun, Zhili; Liu, Zhixiong; Li, Fenglan; Lu, Hai

    2014-01-01

    Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development in Arabidopsis thaliana. CEP1 is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole. cep1 mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in the cep1 mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development. CEP1 overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that proper CEP1 expression is necessary for timely degeneration of tapetal cells and functional pollen formation. PMID:25035401

  3. Vegetation and climate history in arid western China during MIS2: New insights from pollen and grain-size data of the Balikun Lake, eastern Tien Shan

    NASA Astrophysics Data System (ADS)

    Zhao, Yongtao; An, Cheng-Bang; Mao, Limi; Zhao, Jiaju; Tang, Lingyu; Zhou, Aifeng; Li, Hu; Dong, Weimiao; Duan, Futao; Chen, Fahu

    2015-10-01

    Marine Isotope Stage (MIS) 2 is mostly a cold period encompassing the Last Glacial Maximum (LGM), but the regional expression of MIS2 in arid areas of China is not well known. In this paper, we use high-resolution lacustrine pollen and grain-size records from Balikun Lake to infer vegetation, lake evolution, and climate in arid western China during MIS2. Our results suggest that: 1) the regional vegetation around Balikun was mainly dominated by desert and/or desert-steppe, and Balikun Lake was relatively shallow and experienced high aeolian input during MIS2; 2) distinctive runoff from mountain glacial meltwater in the eastern parts of the Balikun basin caused a high relative abundance of Artemisia pollen during the LGM (26.5-19.2 cal kyr BP), while simultaneously the desert areas expanded as indicated by the high abundance of desert shrubs (e.g., Elaeagnaceae, Rhamnaceae, Hippophae). This cold and dry LGM climate triggered a substantial lowering of lake level; 3) an extremely cold and dry climate prevailing from 17.0 to 15.2 cal kyr BP, correlated with Heinrich event 1 (H1), would explain the low vegetation cover found then; and 4) the warm and humid Bølling/Allerød interstadial (BA: ca. 15-ca. 13 cal kyr BP) is clearly recorded in the Balikun region by the development of wetland herb communities (e.g., Poaceae, Cyperaceae, Typha), and the lake level rose due to increased runoff. Our results challenge the traditional view of cold and wet climatic conditions and high lake levels in arid western China during the LGM, and we propose that changes in local temperature modulated by July insolation was an indispensable factor in triggering vegetation evolution in the Balikun region during MIS2.

  4. Pollen viability, pistil receptivity, and embryo development in hybridization of Nelumbo nucifera Gaertn.

    PubMed

    Wang, Yan-Li; Guan, Zhi-Yong; Chen, Fa-Di; Fang, Wei-Min; Teng, Nian-Jun

    2012-01-01

    Seed set is usually low and differs for different crosses of flower lotus (Nelumbo nucifera Gaertn.). The reasons remain unknown, and this has a negative impact on lotus breeding. To determine the causes, we carried out two crosses of flower lotus, that is, "Jinsenianhua" × "Qinhuaihuadeng" and "Qinhuaihuadeng" × "Jinsenianhua" and pollen viability, pistil receptivity, and embryo development were investigated. The pollen grains collected at 05:00-06:00 hrs had the highest viability, and the viabilities of "Jinsenianhua" and "Qinhuaihuadeng" were 20.6 and 15.7%, respectively. At 4 h after artificial pollination, the number of pollen grains germinating on each stigma reached a peak: 63.0 and 17.2 per stigma in "Jinsenianhua" × "Qinhuaihuadeng" and "Qinhuaihuadeng" × "Jinsenianhua", respectively. At 1 d after artificial pollination, the percentages of normal embryos in the two crosses were 55.0 and 21.9%, respectively; however, at 11 d after pollination, the corresponding percentages were 20.8 and 11.2%. Seed sets of the two crosses were 17.9 and 8.0%, respectively. The results suggested that low pistil receptivity and embryo abortion caused low seed set in "Qinhuaihuadeng" × "Jinsenianhua", whereas low fecundity of "Jinsenianhua" × "Qinhuaihuadeng" was mainly attributable to embryo abortion. PMID:22629182

  5. Pollen Viability, Pistil Receptivity, and Embryo Development in Hybridization of Nelumbo nucifera Gaertn

    PubMed Central

    Wang, Yan-Li; Guan, Zhi-Yong; Chen, Fa-Di; Fang, Wei-Min; Teng, Nian-Jun

    2012-01-01

    Seed set is usually low and differs for different crosses of flower lotus (Nelumbo nucifera Gaertn.). The reasons remain unknown, and this has a negative impact on lotus breeding. To determine the causes, we carried out two crosses of flower lotus, that is, “Jinsenianhua” × “Qinhuaihuadeng” and “Qinhuaihuadeng” × “Jinsenianhua” and pollen viability, pistil receptivity, and embryo development were investigated. The pollen grains collected at 05:00-06:00 hrs had the highest viability, and the viabilities of “Jinsenianhua” and “Qinhuaihuadeng” were 20.6 and 15.7%, respectively. At 4 h after artificial pollination, the number of pollen grains germinating on each stigma reached a peak: 63.0 and 17.2 per stigma in “Jinsenianhua” × “Qinhuaihuadeng” and “Qinhuaihuadeng” × “Jinsenianhua”, respectively. At 1 d after artificial pollination, the percentages of normal embryos in the two crosses were 55.0 and 21.9%, respectively; however, at 11 d after pollination, the corresponding percentages were 20.8 and 11.2%. Seed sets of the two crosses were 17.9 and 8.0%, respectively. The results suggested that low pistil receptivity and embryo abortion caused low seed set in “Qinhuaihuadeng” × “Jinsenianhua”, whereas low fecundity of “Jinsenianhua” × “Qinhuaihuadeng” was mainly attributable to embryo abortion. PMID:22629182

  6. 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, ...

  7. 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. ...

  8. 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.

  9. ABORTED GAMETOPHYTE 1 is required for gametogenesis in Arabidopsis.

    PubMed

    Cui, Hong-Hui; Liao, Hong-Ze; Tang, Yu; Du, Xin-Yu; Chen, Li-Qun; Ye, De; Zhang, Xue-Qin

    2015-12-01

    In flowering plants, the male and female gametogenesis is a crucial step of sexual reproduction. Although many genes have been identified as being involved in the gametogenesis process, the genetic mechanisms underlying gametogenesis remains poorly understood. We reported here characterization of the gene, ABORTED GAMETOPHYTE 1 (AOG1) that is newly identified as essential for gametogenesis in Arabidopsis thaliana. AOG1 is expressed predominantly in reproductive tissues including the developing pollen grains and ovules. The AOG1 protein shares no significant amino acid sequence similarity with other documented proteins and is located mainly in nuclei of the cells. Mutation in AOG1 caused degeneration of pollen at the uninucleate microspore stage and severe defect in embryo sacs, leading to a significant reduction in male and female fertility. Furthermore, the molecular analyses showed that the aog1 mutant significantly affected the expression of several genes, which are required for gametogenesis. Our results suggest that AOG1 plays important roles in gametogenesis at the stage prior to pollen mitosis I (PMI) in Arabidopsis, possibly through collaboration with other genes. PMID:25693728

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Pollen Concentration in the Atmosphere of Abha City, Saudi Arabia and its Relationship with Meteorological Parameters

    NASA Astrophysics Data System (ADS)

    Alwadie, Hussein M.

    A qualitative and quantitative evaluation of pollen concentration in the atmosphere of Abha city, Saudi Arabia with the relation to meteorological parameters is presented. Investigations were undertaken from January to December 2006 using a Burkard 7 day volumetric spore trap. A total of 6,492 pollen grains m-3 belonging to 50 pollen taxa was detected. Poaceae represented 55.1% of total pollen, Leguminosae (11.7%), Compositae (6.1%), Solanaceae (4.6%) and Cupressaceae (4.2%). Pollen grains were found throughout the year. July represented the highest peak of pollen number and also the highest pollen taxa. The monthly variation of pollen taxa and their relationship to meteorological parameters were investigated. It was found that the pollen concentration is positively correlated with temperature and negatively correlated with rainfall, relative humidity and wind velocity. May-September represented the months of highest pollen number (95% of total pollen).

  15. Characterization of the maize pollen transcriptome: Validation of microarray results using quantitative real-time PCR

    EPA Science Inventory

    Pollen is the primary means of gene flow between plants and plant populations and plays a critical role in seed production. Pollen fitness can be defined as the ability of a particular pollen grain to outcompete other pollen present on the stigma and complete fertilization, thus ...

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. Mechanical damage to pollen aids nutrient acquisition in Heliconius butterflies (Nymphalidae).

    PubMed

    Krenn, Harald W; Eberhard, Monika J B; Eberhard, Stefan H; Hikl, Anna-Laetitia; Huber, Werner; Gilbert, Lawrence E

    2009-12-01

    Neotropical Heliconius and Laparus butterflies actively collect pollen onto the proboscis and extract nutrients from it. This study investigates the impact of the processing behaviour on the condition of the pollen grains. Pollen samples (n = 72) were collected from proboscides of various Heliconius species and Laparus doris in surrounding habitats of the Tropical Research Station La Gamba (Costa Rica). Examination using a light microscope revealed that pollen loads contained 74.88 ± 53.67% of damaged Psychotria pollen, 72.04 ± 23.4% of damaged Psiguria/Gurania pollen, and 21.35 ± 14.5% of damaged Lantana pollen (numbers represent median ± first quartile). Damaged pollen grains showed deformed contours, inhomogeneous and/or leaking contents, or they were empty. Experiments with Heliconius and Laparus doris from a natural population in Costa Rica demonstrated that 200 min of pollen processing behaviour significantly increased the percentage of damaged pollen of Psychotria compared to pollen from anthers (P = 0.015, Z = -2.44, Mann-Whitney U-test). Examination of pollen loads from green house reared Heliconius butterflies resulted in significantly greater amounts of damaged Psiguria pollen after 200 min of processing behaviour compared to pollen from flowers (P < 0.001, Z = -4.583, Mann-Whitney U-test). These results indicate that pollen processing functions as extra oral digestion whereby pollen grains are ruptured to make the content available for ingestion. PMID:24900162

  2. Impact of common cytostatic drugs on pollen fertility in higher plants.

    PubMed

    Mišík, Miroslav; Kundi, Michael; Pichler, Clemens; Filipic, Metka; Rainer, Bernhard; Mišíková, Katarina; Nersesyan, Armen; Knasmueller, Siegfried

    2016-08-01

    Cytostatic drugs are among the most toxic chemicals which are produced. Many of them cause damage of the genetic material which may affect the fertility of higher organisms. To study the impact of the widely used anticancer drugs [cisplatin (CisPt), etoposide (Et), and 5-fluorouracil (5-FU)] on the reproduction of higher plants, pollen abortion experiments were conducted with species which belong to major plant families, namely with Tradescantia paludosa (Commelinaceae), Arabidopsis thaliana (Brassicaceae), Chelidonium majus (Papaveraceae), and Alisma plantago-aquatica (Alismataceae). All compounds increased the frequencies of abortive grains. The lowest effective doses were in general in a narrow range (i.e., 1 and 10 mg/kg of dry soil). The effects of the individual drugs were similar in T. paludosa, A. plantago-aquatica, and Ch. majus, while A. thaliana was consistently less sensitive. The highest abortion rate was obtained in most experiments with CisPt, followed by 5-FU and Et. Comparisons of the doses which caused effects in the present experiments in the different species with the predicted environment concentrations and with the levels of the cytostatics which were detected in hospital wastewaters show that the realistic environmental concentrations of the drugs are 4-6 orders of magnitude lower. Therefore, it is unlikely that these drugs affect the fertility of higher plants in aquatic and terrestrial ecosystems. PMID:25779110

  3. 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

  4. 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.

  5. Pollen source and resource limitation to fruit production in the rare species Eremosparton songoricum (Fabaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eremosparton songoricum (Litv.) Vass. is a rare, central Asian desert species which shows lower fruit set and seed set (<16%) than most hermaphroditic species. We hypothesized that fruit production was limited by pollen and resources. To evaluate potential fruit abortion due to pollen limitation, su...

  6. 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 ...

  7. Space Shuttle ascent aborts

    NASA Astrophysics Data System (ADS)

    Schmidgall, Richard A.

    1989-09-01

    Specific guidance functions and trajectory design of return to launch site (RTLS) and transoceanic abort landing (TAL) intact abort profiles, as well as the increasing emphasis on contingency aborts, are presented. Various systems failures including Space Shuttle main engine failures and detailed technical analyses, including the design of powered flight abort trajectories, are considered. The most critical of flight abort situations is the RTLS, while TAL is the preferred abort when uphill capability is no longer available. It is concluded that one principle must remain to ensure continuing success of Space Shuttle flights: namely that intact and contingency aborts necessitate development to ensure safe return of the vehicle, payload, and crew whenever possible.

  8. Pollen Production, Microsporangium Dehiscence and Pollen Flow in Himalayan Cedar (Cedrus deodara Roxb. ex D. Don)

    PubMed Central

    KHANDURI, V. P.; SHARMA, C. M.

    2002-01-01

    Microsporangium dehiscence, pollen production and dispersal were studied in Himalayan cedar (Cedrus deodara) during 1998 and 1999. Microsporangium dehiscence showed diurnal periodicity and was found to be related to air temperature and relative air humidity, with a strobilus taking 2 d to dehisce completely in warmer conditions and 3 d in cooler ones. The frequency of flowering in C. deodara was highly variable during the two successive years; however, cyclical production of pollen grains was observed in 50 % of the trees. The maximum concentration of pollen grains in the air was found between 1200 and 1600 h, and this period was also noted to be the best time for pollination. Studying migration of pollen grains from isolated single trees in three directions showed that migration was not uniform in all directions. Long‐distance transport of pollen grains was observed in the downhill direction. However, in the uphill and horizontal directions grains could travel only up to 97·5 and 195·1 m, respectively, and the frequency of pollen grains to the source frequency at these distances was only 1·9 and 2·5 %, respectively. The results suggest that an isolation barrier of 190 m may be considered as a minimum for the management of deodar seed orchards. PMID:12099533

  9. Should abortion be legalized?

    PubMed

    Sodhy, L S

    1968-01-01

    Abortion is an important means of family planning, especially when contraception is unavailable or when it fails. Morbidity associated with legal abortion is low, though illegal abortion is a common cause of maternal mortality. The Union of Soviet Socialist Republic, Hungary, Yugoslavia, Czechoslovakia, Romania, Poland, and the German Demogratic Republic all have laws legalizing abortion. Legalized abortion is the surest method of population control and should be promoted if the moral and religious objections can be overcome. PMID:12255647

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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

  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. 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

  18. 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.

  19. [Abortion and rights. Legal thinking about abortion].

    PubMed

    Perez Duarte, A E

    1991-01-01

    Analysis of abortion in Mexico from a juridical perspective requires recognition that Mexico as a national community participates in a double system of values. Politically it is defined as a liberal, democratic, and secular state, but culturally the Judeo-Christian ideology is dominant in all social strata. This duality complicates all juridical-penal decisions regarding abortion. Public opinion on abortion is influenced on the 1 hand by extremely conservative groups who condemn abortion as homicide, and on the other hand by groups who demand legislative reform in congruence with characteristics that define the state: an attitude of tolerance toward the different ideological-moral positions that coexist in the country. The discussion concerns the rights of women to voluntary maternity, protection of health, and to making their own decisions regarding their bodies vs. the rights of the fetus to life. The type of analysis is not objective, and conclusions depend on the ideology of the analyst. Other elements must be examined for an objective consideration of the social problem of abortion. For example, aspects related to maternal morbidity and mortality and the demographic, economic, and physical and mental health of the population would all seem to support the democratic juridical doctrine that sees the clandestine nature of abortion as the principal problem. It is also observed that the illegality of abortion does not guarantee its elimination. Desperate women will seek abortion under any circumstances. The illegality of abortion also impedes health and educational policies that would lower abortion mortality. There are various problems from a strictly juridical perspective. A correct definition of the term abortion is needed that would coincide with the medical definition. The discussion must be clearly centered on the protected juridical right and the definition of reproductive and health rights and rights to their own bodies of women. The experiences of other

  20. Abortion Before & After Roe

    PubMed Central

    Joyce, Ted; Tan, Ruoding; Zhang, Yuxiu

    2013-01-01

    We use unique data on abortions performed in New York State from 1971–1975 to demonstrate that women travelled hundreds of miles for a legal abortion before Roe. A100- mile increase in distance for women who live approximately 183 miles from New York was associated with a decline in abortion rates of 12.2 percent whereas the same change for women who lived 830 miles from New York lowered abortion rates by 3.3 percent. The abortion rates of nonwhites were more sensitive to distance than those of whites. We found a positive and robust association between distance to the nearest abortion provider and teen birth rates but less consistent estimates for other ages. Our results suggest that even if some states lost all abortion providers due to legislative policies, the impact on population measures of birth and abortion rates would be small as most women would travel to states with abortion services. PMID:23811233

  1. Specialist pollinators deplete pollen in the spring ephemeral wildflower Claytonia virginica.

    PubMed

    Parker, Alison J; Williams, Neal M; Thomson, James D

    2016-08-01

    Pollinators that collect pollen - and specifically, pollen-specialist bees - are often considered to be the best pollinators of a (host) plant. Although pollen collectors and pollen specialists often benefit host plants, especially in the pollen that they deliver (their pollination "effectiveness"), they can also exact substantial costs because they are motivated to collect as much pollen as possible, reducing the proportion of pollen removed that is subsequently delivered to stigmas (their pollination "efficiency"). From the plant perspective, pollen grains that do not pollinate conspecific stigmas are "wasted", and potentially costly. We measured costs and benefits of nectar-collecting, pollen-collecting, and pollen-specialist pollinator visitation to the spring ephemeral Claytonia virginica. Visits by the pollen-specialist bee Andrena erigeniae depleted pollen quickly and thoroughly. Although all pollinators delivered roughly the same number of grains, the pollen specialist contributed most to C. virginica pollen delivery because of high visitation rates. However, the pollen specialist also removed a large number of grains; this removal may be especially costly because it resulted in the depletion of pollen grains in C. virginica populations. While C. virginica appears to rely on pollen transfer by the pollen specialist in these populations, nectar-collecting visitors could provide the same benefit at a lower cost if their visitation rates increased. Pollen depletion affects a pollinator's value to plants, but is frequently overlooked. If they lower the effectiveness of future floral visitors, visits by A. erigeniae females to C. virginica may be more detrimental than beneficial compared to other pollinators and may, in some circumstances, reduce plant fitness rather than increase it. Therefore, A. erigeniae and C. virginica may vary in their degree of mutualism depending on the ecological context. PMID:27551374

  2. Proteomic analyses of apoplastic proteins from germinating Arabidopsis thaliana pollen

    PubMed Central

    Ge, Weina; Song, Yun; Zhang, Cuijun; Zhang, Yafang; Burlingame, Alma L.; Guo, Yi

    2011-01-01

    Pollen grains play important roles in the reproductive processes of flowering plants. The roles of apoplastic proteins in pollen germination and in pollen tube growth are comparatively less well understood. To investigate the functions of apoplastic proteins in pollen germination, the global apoplastic proteins of mature and germinated Arabidopsis thaliana pollen grains were prepared for differential analyses by using 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) saturation labeling techniques. One hundred and three proteins differentially expressed (p value ≤ 0.01) in pollen germinated for 6h compare with un-germination mature pollen, and 98 spots, which represented 71 proteins, were identified by LC-MS/MS. By bioinformatics analysis, 50 proteins were identified as secreted proteins. These proteins were mainly involved in cell wall modification and remodeling, protein metabolism and signal transduction. Three of the differentially expressed proteins were randomly selected to determine their subcellular localizations by transiently expressing YFP fusion proteins. The results of subcellular localization were identical with the bioinformatics prediction. Based on these data, we proposed a model for apoplastic proteins functioning in pollen germination and pollen tube growth. These results will lead to a better understanding of the mechanisms of pollen germination and pollen tube growth. PMID:21798377

  3. 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.

  4. 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.

  5. Pollen tubes introduce Raspberry bushy dwarf virus into embryo sacs during fertilization processes.

    PubMed

    Isogai, Masamichi; Yoshida, Tetu; Shimura, Takuya; Yoshikawa, Nobuyuki

    2015-10-01

    We developed a fertilization method in which pollen tubes entered into embryo sacs without any need to contact surrounding female sporophytic cells by using Torenia fournieri (Torenia) plants under the condition of hindering movement of the virus from a stigma, which is the first infection site leading to systemic infection. When RBDV-infected Torenia pollen grains were used for the developed fertilization method, the virus was transmitted to the seeds by pollen tubes germinating from them. On the other hand, no seeds were infected with the virus when Torenia plants were pollinated with healthy Torenia pollen grains in combination with RBDV-infected raspberry pollen grains, which caused the virus infection in the stigma by penetration of their pollen tubes arrested in its style. Our results indicate that vertical transmission of RBDV by pollen occurs in the transport of the virus into embryo sacs by pollen tubes reaching the embryo sacs. PMID:26176979

  6. Abortion and psychiatric practice.

    PubMed

    Stotland, Nada L

    2003-03-01

    The subject of abortion is fraught with politics, emotions, and misinformation. A widespread practice reaching far back in history, abortion is again in the news. Psychiatry sits at the intersection of the religious, ethical, psychological, sociological, medical, and legal facets of the abortion issue. Although the religions that forbid abortion are more prominent in the media, many religions have more liberal approaches. While the basic right to abortion has been upheld by the U.S. Supreme Court, several limitations have been permitted, including parental notification or consent (with the possibility of judicial bypass) for minors, waiting periods, and mandatory provision of certain, sometimes biased, information. Before the Roe v. Wade decision legalizing abortion in 1973, many women were maimed or killed by illegal abortions, and psychiatrists were sometimes asked to certify that abortions were justified on psychiatric grounds. Currently, there are active attempts to convince the public and women considering abortion that abortion frequently has negative psychiatric consequences. This assertion is not borne out by the literature: the vast majority of women tolerate abortion without psychiatric sequelae. The psychiatric outcome of abortion is best when patients are able to make autonomous, supported decisions. Psychiatrists need to know the medical and psychiatric facts about abortion. Psychiatrists can then help patients prevent unwanted pregnancies, make informed decisions consonant with their own values and circumstances when they become pregnant, and find appropriate social and medical resources whatever their decisions may be. PMID:15985924

  7. From the anther to the proctodeum: Pear (Pyrus communis) pollen digestion in Osmia cornuta larvae.

    PubMed

    Nepi, Massimo; Cresti, Laura; Maccagnani, Bettina; Ladurner, Edith; Pacini, Ettore

    2005-07-01

    Modifications of the pollen grains of Pyrus communis Linneaus that occur during the digestion by Osmia cornuta (Latreille) larvae were studied histochemically. We compared the features of the pollen grains found in the anthers, in the larval cell provisions and in the alimentary canal of the 5th instar larvae. Modifications were already evident in the provisions and consisted of protoplast protrusions through the apertures and a decrease in the number of starch-containing pollen grains. After pollen grains were ingested by the larvae, the protoplast appeared retracted from the pollen wall. Pollen digestion began in the anterior part of the midgut, where we observed: (1) disorganised intine at the apertures; (2) disappearance of DAPI staining of nuclear pollen DNA; (3) fewer pollen grains containing starch than in the anthers; (4) some empty pollen grains. Pollen grains in the proctodeum appeared extremely compressed and crushed. Some grains appeared to be unaffected by the digestive process. We hypothesise that the protrusion of the intine and of the protoplast from the apertures in bee provisions could be considered a kind of pre-treatment necessary to initiate the digestion process in the larval alimentary canal. PMID:16105552

  8. 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

  9. 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

  10. 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

  11. 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

  12. Legalized abortion in Czechoslovakia.

    PubMed

    Zidovsky, J; Zwinger, A

    1972-01-01

    A law legalizing abortion was passed nearly 20 years ago in Czechosl ovakia. The law aimed to give women the freedom to decide for themselves whether they want to be pregnant and to decrease the dangers of illegal abortion. The law resulted in a decreased number of abortions and of complications and deaths associated with abortion. Fertility in the country also declined. In 1968 there were more abortions than live births in the country. Since 1957, the law has been modified. The law still aims to prevent the birth of defective children and to protect the life and health of mothers. Each application for abortion is now examined on its own merits. Favorable economic circumstances, prolife social policies adopted by the government, and the new stricter interpretation of the abortion law have resulted in a r ising birthrate since 1969. Contraception is still stressed as preferab le to abortion. PMID:12256872

  13. Abortion - surgical - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000658.htm Abortion - surgical - aftercare To use the sharing features on ... please enable JavaScript. You have had a surgical abortion. This is a procedure that ends pregnancy by ...

  14. Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas

    NASA Astrophysics Data System (ADS)

    Grewling, Ł.; Bogawski, P.; Jenerowicz, D.; Czarnecka-Operacz, M.; Šikoparija, B.; Skjøth, C. A.; Smith, M.

    2016-02-01

    Allergenic ragweed (Ambrosia spp.) pollen grains, after being released from anthers, can be dispersed by air masses far from their source. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported (LDT) pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen (Amb a 1) collected in ambient air during episodes of LDT still have immunoreactive properties. The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations.

  15. 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

  16. Investigating atmospheric transport of Ambrosia pollen from the Pannonian Plain towards the Balkan region with DEHM-Pollen

    NASA Astrophysics Data System (ADS)

    Ambelas Skjoth, C.

    2009-04-01

    The pollen grains of Ambrosia spp. are considered to be important aeroallergens. The threshold value for clinical symptoms for ragweed pollen grains for the majority of sensitised patients is below 20 grains/m3. Ambrosia pollen appears to induce asthma about twice as often as other pollen. Each ragweed plant produces millions of pollen grains that are small (18-22 μm) and suitable for long-range transport when conditions are favourable. In this study we use DEHM-Pollen to investigate if the Pannonian Plain could be the source area for observed episodes of Ambrosia pollen in the Balkans. A possible Ambrosia pollen inventory for various regions in the Pannonian Plain was constructed using detailed land cover data from Serbia, Hungary, Austria, Croatia, Bosnia-Herzegovina, Slovakia, Romania and Czech Republic in combination with measurements of the annual load of Ambrosia pollen in the source areas. A simple unified pollen release model (SUPREME) was calibrated against daily measurements from Novi Sad in Serbia and implemented in DEHM-Pollen with the Ambrosia pollen inventory. Model simulations was then performed with DEHM-Pollen for the months August and September 2007 and compared with measurements from stations outside the Pannonian Plain. The simulations several times indicate regional scale transport from the Pannonian Plain towards the Balkan region including the 26th - 27th of August and the 1st and 2nd September. During these episode air masses passed over parts of Bosnia and Herzegovina, Southern Serbia, Albania and Macedonia. The verifying measurements at Skopje (Macedonia) show episodes of elevated Ambrosia pollen concentration the 26th -27th of August and for the 1st and 2nd of September. The model experiments with DEHM-Pollen strongly indicate that the Pannonian Plain alone can be a source to significant Ambrosia pollen concentrations in the Balkans. The methods and the model results look promising with respect to future numerical forecasting of Ambrosia

  17. 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

  18. Late-term abortion.

    PubMed

    Epner, J E; Jonas, H S; Seckinger, D L

    1998-08-26

    Recent proposed federal legislation banning certain abortion procedures, particularly intact dilatation and extraction, would modify the US Criminal Code such that physicians performing these procedures would be liable for monetary and statutory damages. Clarification of medical procedures is important because some of the procedures used to induce abortion prior to viability are identical or similar to postviability procedures. This article reviews the scientific and medical information on late-term abortion and late-term abortion techniques and includes data on the prevalence of late-term abortion, abortion-related mortality and morbidity rates, and legal issues regarding fetal viability and the balance of maternal and fetal interests. According to enacted American Medical Association (AMA) policy, the use of appropriate medical terminology is critical in defining late-term abortion procedures, particularly intact dilatation and extraction, which is a variant of but distinct from dilatation and evacuation. The AMA recommends that the intact dilatation and extraction procedure not be used unless alternative procedures pose materially greater risk to the woman and that abortions not be performed in the third trimester except in cases of serious fetal anomalies incompatible with life. Major medical societies are urged to collaborate on clinical guidelines on late-term abortion techniques and circumstances that conform to standards of good medical practice. More research on the advantages and disadvantages of specific abortion procedures would help physicians make informed choices about specific abortion procedures. Expanded ongoing data surveillance systems estimating the prevalence of abortion are also needed. PMID:9728645

  19. Abortion among Adolescents.

    ERIC Educational Resources Information Center

    Adler, Nancy E.; Ozer, Emily J.; Tschann, Jeanne

    2003-01-01

    Reviews the current status of abortion laws pertaining to adolescents worldwide, examining questions raised by parental consent laws in the United States and by the relevant psychological research (risk of harm from abortion, informed consent, consequences of parental involvement in the abortion decision, and current debate). Discusses issues…

  20. 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

  1. Reconstructing Earth's Past Climates: The Hidden Secrets of Pollen

    ERIC Educational Resources Information Center

    Steele, Adrienne; Warny, Sophie

    2013-01-01

    "Palynology" is the study of fossil pollen and spores, and these tiny grains can provide fundamental information about past climates on Earth. Among their many unique and useful properties, pollen and spores are composed of some of the most chemically resistant organic compounds found in nature. They are also produced in vast quantities and are…

  2. Cotton pollen retention in boll weevils, a laboratory experiment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton pollen is thought to exist in a boll weevil’s gut for at least 18 hours. In a controlled laboratory experiment examining non-cotton food sources, a cotton pollen grain was found in an individual boll weevil that had not fed on cotton for 120 hours. Because we believe that finding whole or ...

  3. Variation in Pollen-Donor Composition among Pollinators in an Entomophilous Tree Species, Castanea crenata, Revealed by Single-Pollen Genotyping

    PubMed Central

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2015-01-01

    Background In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored roles of foraging behavior of insect pollinators on pollen-donor composition and subsequent reproductive success in a woody plant. Methods We performed paternity analyses based on microsatellite genotyping of individual pollen grains found on diurnal pollinators (i.e., bumblebee, small bee, fly, small beetle, and honeybee) visiting Castanea crenata trees. Results The outcross-pollen rate was highest in bumblebees (66%), followed by small bees (35%), flies (31%), and small beetles (18%). The effective number of pollen donors, representing pollen carryover, was greater in bumblebees (9.71) than in flies (3.40), small bees (3.32), and small beetles (3.06). The high percentages of pollen from outside the plot on bumblebees (65.4%) and flies (71.2%) compared to small bees (35.3%) and small beetles (13.5%) demonstrated their longer pollen dispersal distances. Conclusions All of the diurnal insects carried outcross-pollen grains for long distances via pollen carryover. This fact suggests that a wide range of insect taxa are potential outcross-pollen transporters for the self-incompatible C. crenata. PMID:25793619

  4. Abortion in Ireland.

    PubMed

    Francome, C

    1992-08-22

    Substantial legal barriers to abortion persist in both the Irish Republic and Northern Ireland, despite growing popular support for abortion under certain conditions. A 1983 amendment to the republic's constitution guarantees the fetus the same right to life s the mother and bans the provision of information on abortion. Although a recent well publicized case of a pregnant, suicidal 14-year-old who travelled to England for an abortion resulted in an Irish Supreme Court ruling that abortion was acceptable in cases of "real and substantial risk" to a woman's life, uncertainty still surrounds the right to travel to England for the procedure. In Northern Ireland, the 1967 Abortion Act does not apply and abortions are denied even in cases of rape and incest. A total of 1766 women from Northern Ireland and 4158 from the republic travelled to England for abortions in 1991. Public opinion seems to have shifted toward support for less restrictive abortion laws, however. Whereas 80% of those surveyed in a 1980 Irish poll supported to ban on abortion in all cases, this statistic had dropped to 30% by 1990. Similarly, a 1991 poll taken in Northern Ireland found 80% of respondents to be a favor of abortion in cases where the procedure is necessary to maintain a woman's physical or mental health. PMID:1392954

  5. Callose plug deposition patterns vary in pollen tubes of Arabidopsis thaliana ecotypes and in tomato species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background The pollen grain contains the male gametophyte that extends a pollen tube that grows through female tissues in order to deliver sperm to the embryo sac for double fertilization. Growing pollen tubes form periodic callose plugs that are thought to block off the older parts of the tube and ...

  6. 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

  7. 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.

  8. A Multiscale Vibrational Spectroscopic Approach for Identification and Biochemical Characterization of Pollen

    PubMed Central

    Bağcıoğlu, Murat; Zimmermann, Boris; Kohler, Achim

    2015-01-01

    Background Analysis of pollen grains reveals valuable information on biology, ecology, forensics, climate change, insect migration, food sources and aeroallergens. Vibrational (infrared and Raman) spectroscopies offer chemical characterization of pollen via identifiable spectral features without any sample pretreatment. We have compared the level of chemical information that can be obtained by different multiscale vibrational spectroscopic techniques. Methodology Pollen from 15 different species of Pinales (conifers) were measured by seven infrared and Raman methodologies. In order to obtain infrared spectra, both reflectance and transmission measurements were performed on ground and intact pollen grains (bulk measurements), in addition, infrared spectra were obtained by microspectroscopy of multigrain and single pollen grain measurements. For Raman microspectroscopy measurements, spectra were obtained from the same pollen grains by focusing two different substructures of pollen grain. The spectral data from the seven methodologies were integrated into one data model by the Consensus Principal Component Analysis, in order to obtain the relations between the molecular signatures traced by different techniques. Results The vibrational spectroscopy enabled biochemical characterization of pollen and detection of phylogenetic variation. The spectral differences were clearly connected to specific chemical constituents, such as lipids, carbohydrates, carotenoids and sporopollenins. The extensive differences between pollen of Cedrus and the rest of Pinaceae family were unambiguously connected with molecular composition of sporopollenins in pollen grain wall, while pollen of Picea has apparently higher concentration of carotenoids than the rest of the family. It is shown that vibrational methodologies have great potential for systematic collection of data on ecosystems and that the obtained phylogenetic variation can be well explained by the biochemical composition of

  9. 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

  10. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor.

    PubMed

    Dong, Shanshan; Liu, Yan; Yu, Cigang; Zhang, Zhenhua; Chen, Ming; Wang, Changyong

    2016-01-01

    Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow. PMID:26975052

  11. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor

    PubMed Central

    Dong, Shanshan; Liu, Yan; Yu, Cigang; Zhang, Zhenhua; Chen, Ming; Wang, Changyong

    2016-01-01

    Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow. PMID:26975052

  12. 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...

  13. A pollen-specific calmodulin-binding protein, NPG1, interacts with putative pectate lyases

    PubMed Central

    Shin, Sung-Bong; Golovkin, Maxim; Reddy, Anireddy S. N.

    2014-01-01

    Previous genetic studies have revealed that a pollen-specific calmodulin-binding protein, No Pollen Germination 1 (NPG1), is required for pollen germination. However, its mode of action is unknown. Here we report direct interaction of NPG1 with pectate lyase-like proteins (PLLs). A truncated form of AtNPG1 lacking the N-terminal tetratricopeptide repeat 1 (TPR1) failed to interact with PLLs, suggesting that it is essential for NPG1 interaction with PLLs. Localization studies with AtNPG1 fused to a fluorescent reporter driven by its native promoter revealed its presence in the cytosol and cell wall of the pollen grain and the growing pollen tube of plasmolyzed pollen. Together, our data suggest that the function of NPG1 in regulating pollen germination is mediated through its interaction with PLLs, which may modify the pollen cell wall and regulate pollen tube emergence and growth. PMID:24919580

  14. 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).

  15. Abortion ruling in Quebec.

    PubMed

    Brahams, D

    1989-08-01

    Brahams summarizes a 1989 Quebec Court of Appeal decision in an abortion case and places the ruling in the context of worldwide trends in abortion regulation. In Tremblay v. Daigle (1989 Jul 26), the Quebec court upheld a lower court injunction banning a woman from having an abortion. The injunction had been obtained by the woman's former boyfriend, the putative father. Brahams discusses the current legal status of abortion in Canada, the Daigle court's reasoning, and how the British approach to the legal status of fathers and fetuses in abortion disputes differs from the Canadian. She also briefly summarizes recent abortion-related judicial and regulatory developments in the United States, Ireland, and France. PMID:2569146

  16. The Beauty and Biology of Pollen.

    ERIC Educational Resources Information Center

    Clay-Poole, Scott T.; Slesnick, Irwin L.

    1983-01-01

    Describes: basic features of pollen grains (shapes, apertures, layering of wall, exine sculpturing); strategies for pollination (anemophily--wind transported, zoophily--animal transported); and the structures specialized for each process. Gives instructions for using scanning electron microscope photographs and for collecting, identifying, and…

  17. [Bioethics and abortion. Debate].

    PubMed

    Diniz, D; Gonzalez Velez, A C

    1998-06-01

    Although abortion has been the most debated of all issues analyzed in bioethics, no moral consensus has been achieved. The problem of abortion exemplifies the difficulty of establishing social dialogue in the face of distinct moral positions, and of creating an independent academic discussion based on writings that are passionately argumentative. The greatest difficulty posed by the abortion literature is to identify consistent philosophical and scientific arguments amid the rhetorical manipulation. A few illustrative texts were selected to characterize the contemporary debate. The terms used to describe abortion are full of moral meaning and must be analyzed for their underlying assumptions. Of the four main types of abortion, only 'eugenic abortion', as exemplified by the Nazis, does not consider the wishes of the woman or couple--a fundamental difference for most bioethicists. The terms 'selective abortion' and 'therapeutic abortion' are often confused, and selective abortion is often called eugenic abortion by opponents. The terms used to describe abortion practitioners, abortion opponents, and the 'product' are also of interest in determining the style of the article. The video entitled "The Silent Scream" was a classic example of violent and seductive rhetoric. Its type of discourse, freely mixing scientific arguments and moral beliefs, hinders analysis. Within writings about abortion three extreme positions may be identified: heteronomy (the belief that life is a gift that does not belong to one) versus reproductive autonomy; sanctity of life versus tangibility of life; and abortion as a crime versus abortion as morally neutral. Most individuals show an inconsistent array of beliefs, and few groups or individuals identify with the extreme positions. The principal argument of proponents of legalization is respect for the reproductive autonomy of the woman or couple based on the principle of individual liberty, while heteronomy is the main principle of

  18. [Abortion law in Italy].

    PubMed

    Havránek, F

    1979-04-01

    On May 28, 1978, the Italian senate passed a law legalizing abortions. The law, passed against the will of the Christian Democrat party and the Vatican, is the most liberal in Western Europe. Any woman 18 or older is free to seek an abortion at a private or public institution during the first 90 days of pregnancy. Abortions can be sought on health, economic, social, family, or psychological grounds. A woman requests an abortion at a hospital or clinic, or from a physician. If termination is deemed urgent, the procedure may be performed immediately. If a request is denied, a woman may make another request 7 days later. Second trimester abortions are permitted only if grave danger to the woman or deformation of the fetus is suspected. Women under 18 meed the permission of their parents or legal guardians; a court may also grant permission. Passage of the law has facilitated open debate on the legal and medical aspects of abortion. It has also guaranteed women access to abortions. Physicians, who on grounds of conscience feel they can't perform abortions, may register to be exempt from having to perform them. They may not, however, deny a woman care before and after her abortion, and if they perform the procedure even once, their name is removed from the exempt register. Additionally, all physicians are bound to attempt to preserve the life of all women as well as any fetus which shows life outside the womb. PMID:445601

  19. 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

  20. 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.

  1. Links between pollen, atopy and the asthma epidemic.

    PubMed

    Taylor, Philip E; Jacobson, Kraig W; House, James M; Glovsky, M Michael

    2007-01-01

    Pollen allergy has been found in 80-90% of childhood asthmatics and 40-50% of adult-onset asthmatics. Despite the high prevalence of atopy in asthmatics, a causal relationship between the allergic response and asthma has not been clearly established. Pollen grains are too large to penetrate the small airways where asthma occurs. Yet pollen cytoplasmic fragments are respirable and are likely correlated with the asthmatic response in allergic asthmatics. In this review, we outline the mechanism of pollen fragmentation and possible pathophysiology of pollen fragment-induced asthma. Pollen grains rupture within the male flowers and emit cytoplasmic debris when winds or other disturbances disperse the pollen. Peak levels of grass and birch pollen allergens in the atmosphere correlated with the occurrence of moist weather conditions during the flowering period. Thunderstorm asthma epidemics may be triggered by grass pollen rupture in the atmosphere and the entrainment of respirable-sized particles in the outflows of air masses at ground level. Pollen contains nicotinamide adenine dinucleotide phosphate (reduced) oxidases and bioactive lipid mediators which likely contribute to the inflammatory response. Several studies have examined synergistic effects and enhanced immune response from interaction in the atmosphere, or from co-deposition in the airways, of pollen allergens, endogenous pro-inflammatory agents, and the particulate and gaseous fraction of combustion products. Pollen and fungal fragments also contain compounds that can suppress reactive oxidants and quench free radicals. It is important to know more about how these substances interact to potentially enhance, or even ameliorate, allergic asthma. PMID:17536216

  2. 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.

  3. [Prevention of abortion].

    PubMed

    Alberti, N; Nègre-Garnier, C

    1994-03-01

    Psychologists and marriage counselors conducting preabortion interviews in a French clinic note that women have emotions concerning abortion apart from the reasons they give for choosing to end their pregnancies. Their experience demonstrates that a pregnancy never occurs by chance, but always at a given moment of existence. An abortion becomes an event in the significant and particular history of each woman undergoing one. Particular circumstances of unemployment, illness, or other adversity become linked in the woman's later recollections of the abortion. Abortions often signify psychic problems of separation or loss, as demonstrated by the considerable number of immigrant women who undergo abortions after having been obliged to leave their native lands, or those who undergo abortions after the death of a child. Women choosing abortion experience anguish and guilt. Fantasies of the aborted child represent the period of mourning that must be surmounted. The psychic labor of the grief process allows a progressive detachment to be achieved. The belief that expanded knowledge and use of contraception would lead to a significant decline in abortion has been belied by experience; the number of abortions has been stable over the years despite ever increasing use of contraceptives of all types. The objective of contraception, a harmonious sexual relationship in which pregnancy does not occur, is itself complex. Choices related to a more or less distant future are made by individuals who are to a greater or lesser extent engaged in the relationship using more or less inconvenient techniques. Statements made by couples themselves perfectly reflect the paradoxes. Objections and resistances to contraceptive use are also prompted by societal norms of sex and reproduction. The couple are influenced in their abortion decision by their own level of maturity and by their family backgrounds. PMID:8009399

  4. 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

  5. High temperature stress and its effect on pollen development and morphological components of harvest index in the C3 model grass Brachypodium distachyon.

    PubMed

    Harsant, Jeffrey; Pavlovic, Lazar; Chiu, Greta; Sultmanis, Stefanie; Sage, Tammy L

    2013-07-01

    The effect of high temperatures on harvest index (HI) and morphological components that contribute to HI was investigated in two lines (Bd21 and Bd21-3) of Brachypodium distachyon, a C3 grass recognized as a tractable plant, to address critical issues associated with enhancing cereal crop yields in the presence of global climate change. The results demonstrated that temperatures ≥32 °C eliminated HI. Reductions in yield at 32 °C were due primarily to declines in pollen viability, retention of pollen in anthers, and pollen germination, while abortion of microspores by the uninucleate stage that was correlated with abnormal tapetal development resulted in yield failure at 36 °C. Increasing temperatures from 24 to 32 °C resulted in reductions in tiller numbers but had no impact on axillary branch numbers per tiller. Grain developed at 24 and 28 °C primarily in tiller spikes, although spikes on axillary branches also formed grain. Grain quantity decreased in tiller spikes but increased in axillary branch spikes as temperatures rose from 24 to 28 °C. Differential patterns of axillary branching and floret development within spikelets between Bd21 and Bd21-3 resulted in higher grain yield in axillary branches of Bd21-3 at 28 °C. The response of male reproductive development and tiller branching patterns in B. distachyon to increasing temperatures mirrors that in other cereal crops, providing support for the use of this C3 grass in assessing the molecular control of HI in the presence of global warming. PMID:23771979

  6. 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.

  7. Abortion: the new debate.

    PubMed

    Callahan, D

    1986-06-01

    The course of the debate on abortion following the 1973 Supreme Court decision legalizing abortion has been marked by a variety of medical and scientific developments. Many of these new developments have important legal, psychologic, social, moral, and political implications. The cumulative impact of all these developments may pose a significant challenge to the social and legal foundations of Roe v. Wade. PMID:3523563

  8. Psychosocial aspects of abortion

    PubMed Central

    Illsley, Raymond; Hall, Marion H.

    1976-01-01

    The literature on psychosocial aspects of abortion is confusing. Individual publications must be interpreted in the context of cultural, religious, and legal constraints obtaining in a particular society at a given time, with due attention to the status and availability of alternatives to abortion that might be chosen by a woman with an “unwanted” pregnancy. A review of the literature shows that, where careful pre- and post-abortion assessments are made, the evidence is that psychological benefit commonly results, and serious adverse emotional sequelae are rare. The outcome of refused abortion seems less satisfactory, with regrets and distress frequently occurring. Research on the administration of abortion services suggests that counselling is often of value, that distress is frequently caused by delays in deciding upon and in carrying out abortions, and by unsympathetic attitudes of service providers. The phenomenon of repeated abortion seeking should be seen in the context of the availability and cost of contraception and sterilization. The place of sterilization with abortion requires careful study. A recommendation is made for observational descriptive research on populations of women with potentially unwanted pregnancies in different cultures, with comparisons of management systems and an evaluation of their impact on service users. PMID:1085671

  9. Abortion in Adolescence.

    ERIC Educational Resources Information Center

    Campbell, Nancy B.; And Others

    1988-01-01

    Explored differences between 35 women who had abortions as teenagers and 36 women who had abortions as adults. Respondents reported on their premorbid psychiatric histories, the decision-making process itself, and postabortion distress symptoms. Antisocial and paranoid personality disorders, drug abuse, and psychotic delusions were significantly…

  10. Access to legal abortion.

    PubMed

    1993-10-01

    Countries are grouped by the nature and extent of access to legal abortion. The categories include abortion on demand, for social reasons, for health reasons, for rape or incest or to save a mother's life, and only to save a mother's life. Abortion on demand is available for about 40% of the world's population and may have restrictions, such as parental consent or approval of state committees or physicians. There are 22 countries in Europe, 12 in the former Soviet Union, four in Asia, four in the Americas, one in the Middle East (Turkey), and one in Africa (Tunisia) which provide access to early abortion on demand. Abortion for social and economic reasons is available to 21% of the world's population in five countries in Asia, three in Europe (Great Britain, Finland, and Hungary), and one in Africa (Zambia). Abortion for health reasons is available to 16% of the world's population located in 21 countries in Africa, eight in the Americas, seven in Asia, five in Europe, and four in the Middle East. Laws governing about 5% of the world's population permit abortion only in the case of rape, incest, or when a mother's life is in danger (Brazil, Mexico, and Sudan). 18% of the world's population is covered by laws which permit an abortion only when a mother's life is in danger; this includes 19 countries in Africa, 11 in the Americas, nine in Asia, seven in the Middle East, and one in Europe (Ireland). PMID:12287145

  11. "Conservative" views of abortion.

    PubMed

    Devine, P E

    1997-01-01

    The introduction to this essay, which presents and defends the "conservative" position on abortion, explains that this position holds that 1) abortion is wrong because it destroys the fetus; 2) the fetus has full personhood from conception (or very near conception); 3) abortion is only justified under special circumstances, such as when the pregnancy poses a threat to the woman's life; and 4) these conclusions should be reflected in law and public policy. Part 2 sets forth the moral foundations for this position. The third part considers the status of the fetus and reviews the various arguments that have been forwarded to resolve the question, such as the species principle, the potentiality principle, the sentience principle, and the conventionalist principle. Part 4 applies the conservative position to problems posed by hard cases, determines that abortion is a form of homicide from two weeks after fertilization (at the latest), reviews circumstances in which various legal definitions of homicide are applicable, argues for the denial of abortion funding by the state, and notes that violent militancy is not the appropriate response to a belief that abortion should be illegal. Section 5 refutes objections to the conservative position based on the fact that some opponents of abortion also oppose contraception, based on feminist ideals, and based on calls for religious freedom in a pluralistic society. In conclusion, the labels applied to the abortion debate are examined, and it is suggested that "communitarian" is the best term for the conservative position. PMID:12348327

  12. Induced abortion: epidemiological aspects.

    PubMed Central

    Baird, D

    1975-01-01

    Sir Dugald Baird sketches the history of abortion legislation in Great Britain from the beginning of the century. In his views the 1967 Abortion Act has been one of the most important and beneficial pieces of social legislation enacted in Britain in the last 100 years. It has, however, brought problems both of administration in the hospitals and to individual doctors and nurses, particularly when the patients are young single women and even schoolgirls. One of the consequences of the Abortion Act has been a fall in maternal mortality and perinatal mortality rates. Abortion does not seem to be followed by serious emotional sequelae. Nevertheless recent changes in sexual mores have introduced new and serious social problems which are discussed in relation to the role of the doctor in his relationship with patients seeking abortion. PMID:765461

  13. Abortion: a history.

    PubMed

    Hovey, G

    1985-01-01

    This review of abortion history considers sacred and secular practice and traces abortion in the US, the legacy of the 19th century, and the change that occurred in the 20th century. Abortion has been practiced since ancient times, but its legality and availability have been threatened continuously by forces that would denigrate women's fundamental rights. Currently, while efforts to decrease the need for abortion through contraception and education continue, access to abortion remains crucial for the well-being of millions of women. That access will never be secure until profound changes occur in the whole society. Laws that prohibit absolutely the practice of abortion are a relatively recent development. In the early Roman Catholic church, abortion was permitted for male fetuses in the first 40 days of pregnancy and for female fetuses in the first 80-90 days. Not until 1588 did Pope Sixtus V declare all abortion murder, with excommunication as the punishment. Only 3 years later a new pope found the absolute sanction unworkable and again allowed early abortions. 300 years would pass before the Catholic church under Pius IX again declared all abortion murder. This standard, declared in 1869, remains the official position of the church, reaffirmed by the current pope. In 1920 the Soviet Union became the 1st modern state formally to legalize abortion. In the early period after the 1917 revolution, abortion was readily available in state operated facilities. These facilities were closed and abortion made illegal when it became clear that the Soviet Union would have to defend itself against Nazi Germany. After World War II women were encouraged to enter the labor force, and abortion once again became legal. The cases of the Catholic church and the Soviet Union illustrate the same point. Abortion legislation has never been in the hands of women. In the 20th century, state policy has been determined by the rhythms of economic and military expansion, the desire for cheap

  14. Abortion in adolescence.

    PubMed

    Greydanus, D E; Railsback, L D

    1985-09-01

    This article reviews the difficult but complex subject of abortion in adolescents. Methods of abortion are outlined and additional aspects are presented: psychological effects, counseling issues, and legal parameters. It is our conclusion that intense efforts should be aimed at education of youth about sexuality and prevention of pregnancy, utilizing appropriate contraceptive services. When confronted with a youth having an unwanted pregnancy, all legal options need to be carefully explored: delivery, adoption, or abortion. The decision belongs to the youth and important individuals in her environment. Understanding developmental aspects of adolescence will help the clinician deal with the pregnant teenagers. If abortion is selected, a first trimester procedure is best. Finally, physicians are urged to be aware of the specific, ever changing legal dynamics concerning this subject which are present in their states. Abortion is a phenomenon which has become an emotional but undeniably important aspect of adolescent sexuality and adolescent health care, in this country and around the world. PMID:3916607

  15. Pollen loads and specificity of native pollinators of lowbush blueberry.

    PubMed

    Moisan-Deserres, J; Girard, M; Chagnon, M; Fournier, V

    2014-06-01

    The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem. PMID:25026677

  16. 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

  17. 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.

  18. Zinc is critically required for pollen function and fertilisation in lentil.

    PubMed

    Pandey, Nalini; Pathak, Girish Chandra; Sharma, Chandra Prakash

    2006-01-01

    The role of zinc (Zn) in reproduction of lentil (Lens culinaris Medik. cv. DPL 15) and the extent to which the Zn requirement for reproduction can be met through supplementation of Zn at the time of initiation of the reproductive phase have been investigated. Low supply (0.1micromol/L) of Zn reduced the size of anthers, the pollen producing capacity and the size and viability of the pollen grains. Scanning electron microscopy (SEM) of pollen grains of Zn deficient plants showed enhanced thickening of exine and wide and raised muri. In vitro germination of pollen grains was reduced by >50% and growth of pollen tubes was retarded. Unlike Zn sufficient plants, the cuticle around the stigmatic papillae of Zn deficient plants remained intact, preventing the interaction between pollen grains and stigmatic exudates that provides the polarity for the growth of pollen tubes through the stylar tract. Zn deficiency increased the activity of acid phosphatase and peroxidase in extracts of pollen grains. Histochemical localisation on the stigmatic surface and native PAGE of the enzyme extracts of pollen grain and stigma exudates showed enhanced expression of acid phosphatase and peroxidase and suppressed expression of esterase in response to Zn deficiency. Zn deficiency reduced the setting of seeds and also their viability. The effect on seed setting was more marked than on in vitro germination of pollen grains, suggesting that the latter was not the exclusive cause of inhibition of fertility. Possibly, loss of fertility was also caused by impairment in pollen-pistil interaction conducive to pollen tube growth and fertilisation. Impairment in pollen structure and function and seed setting was observed even when plants were deprived of Zn at the time of flowering, but to a lesser extent than in plants maintained with low Zn supply from the beginning. Increasing the Zn supply from deficient to sufficient at the initiation of flowering decreased the severity of Zn deficiency

  19. 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

  20. Water status and associated processes mark critical stages in pollen development and functioning

    PubMed Central

    Firon, Nurit; Nepi, Massimo; Pacini, Ettore

    2012-01-01

    Background The male gametophyte developmental programme can be divided into five phases which differ in relation to the environment and pollen hydration state: (1) pollen develops inside the anther immersed in locular fluid, which conveys substances from the mother plant – the microsporogenesis phase; (2) locular fluid disappears by reabsorption and/or evaporation before the anther opens and the maturing pollen grains undergo dehydration – the dehydration phase; (3) the anther opens and pollen may be dispersed immediately, or be held by, for example, pollenkitt (as occurs in almost all entomophilous species) for later dispersion – the presentation phase; (4) pollen is dispersed by different agents, remaining exposed to the environment for different periods – the dispersal phase; and (5) pollen lands on a stigma and, in the case of a compatible stigma and suitable conditions, undergoes rehydration and starts germination – the pollen–stigma interaction phase. Scope This review highlights the issue of pollen water status and indicates the various mechanisms used by pollen grains during their five developmental phases to adjust to changes in water content and maintain internal stability. Conclusions Pollen water status is co-ordinated through structural, physiological and molecular mechanisms. The structural components participating in regulation of the pollen water level, during both dehydration and rehydration, include the exine (the outer wall of the pollen grain) and the vacuole. Recent data suggest the involvement of water channels in pollen water transport and the existence of several molecular mechanisms for pollen osmoregulation and to protect cellular components (proteins and membranes) under water stress. It is suggested that pollen grains will use these mechanisms, which have a developmental role, to cope with environmental stress conditions. PMID:22523424

  1. 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

  2. Legalized Abortion in Japan

    PubMed Central

    Hart, Thomas M.

    1967-01-01

    The enactment of the Eugenic Protection Act in Japan was followed by many changes. The population explosion was stemmed, the birth rate was halved, and while the marriage rate remained steady the divorce rate declined. The annual total of abortions increased until 1955 and then slowly declined. The highest incidence of abortions in families is in the 30 to 34 age group when there are four children in the family. As elsewhere abortion in advanced stages of pregnancy is associated with high morbidity and mortality. There is little consensus as to the number of criminal abortions. Reasons for criminal abortions can be found in the legal restrictions concerning abortion: Licensing of the abortionist, certification of hospitals, taxation of operations and the requirement that abortion be reported. Other factors are price competition and the patient's desire for secrecy. Contraception is relatively ineffective as a birth control method in Japan. Oral contraceptives are not yet government approved. In 1958 alone 1.1 per cent of married women were sterilized and the incidence of sterilization was increasing. PMID:6062283

  3. Undue burden of abortion.

    PubMed

    Charo, A

    1992-07-01

    In Planned Parenthood vs. Casey, the US Supreme Court upheld all but 1 provision of Pennsylvania law that further restricts access to abortion. The law has a 24-hour waiting period, parental consent for minors with a judicial bypass, husband notification, and the circumstances of each abortion are to be reported to the state for statistical purposes. The Court overturned the husband notification provision even though it had a bypass procedure. The most important aspect of the decision was the change from the strict scrutiny in which abortion was to be left alone unless the state could show a compelling need to regulate it to an undue burden test in which the state is allowed to regulate abortion so long as it does not place an undue burden on women trying to seek abortion services. The 24-hour waiting period was upheld; however, it was also acknowledged that since 83% of women live in counties without abortion services, this may turn out to be an undue burden and it is open to review at later date when statistical evidence is available. The Opinion was written by Justices O'Connor, Kennedy, and Souter. Chief Justice Rehnquist and Justices Scalia, White, and Thomas dissented saying that the undue burden standard was unprecedented in constitutional law and undefinable in practice. It is likely now that the Court will begin writing abortion policy as it clarifies each specific point of the law rather than ruling on fundamental legal principles. PMID:1351612

  4. Legalized abortion in Japan.

    PubMed

    Hart, T M

    1967-10-01

    The enactment of the Eugenic Protection Act in Japan was followed by many changes. The population explosion was stemmed, the birth rate was halved, and while the marriage rate remained steady the divorce rate declined. The annual total of abortions increased until 1955 and then slowly declined. The highest incidence of abortions in families is in the 30 to 34 age group when there are four children in the family. As elsewhere abortion in advanced stages of pregnancy is associated with high morbidity and mortality. There is little consensus as to the number of criminal abortions. Reasons for criminal abortions can be found in the legal restrictions concerning abortion: Licensing of the abortionist, certification of hospitals, taxation of operations and the requirement that abortion be reported. Other factors are price competition and the patient's desire for secrecy. Contraception is relatively ineffective as a birth control method in Japan. Oral contraceptives are not yet government approved. In 1958 alone 1.1 per cent of married women were sterilized and the incidence of sterilization was increasing. PMID:6062283

  5. 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

  6. 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)

  7. Abortion: the hidden plague.

    PubMed

    Tuckwell, S

    1974-05-01

    Abortion is called the invisible plague of all countries and cultures in the twentieth century. It is by far the most important method of birth control in the world today. For every 200 babies born there are at least 100 abortions. In the rich world, a woman who wants to end her pregnancy goes to an abortionist, but for millions of poor women, abortion happens spontaneously in their own homes induced by poor nutrition, sheer physical weakness, and too many pregnancies too close together. In countries where abortion is illegal, millions of women die each year as a result of severe illness or the botched handiwork of backyard operators. The most common complications are massive hemorrhaging, perforation of the uterus, laceration, sepsis, and renal failure. The experience of a great many countries shows that simply legalizing abortion can lead to a dramatic drop in death and illness. Relaxation of abortion laws can save lives, money, and misery for mothers and children. Illegal abortion has become a major problem in Africa there are 3 main types of women who enter hospitals with complications after abortions: 1) the teenager who is away from home; 2) the young woman, often educated, working, and with financial responsibilities, who is ambitious for herself, her husband, or her family; and 3) the woman in her thirties, illiterate, a rural worker, married most of her reproductive life, and pregnant most years. The third type of woman may abort because her system is utterly depleted. Such women must be shown that there is a good chance of survival for her children so that she will not have so many. PMID:12307249

  8. Demand for abortion and post abortion care in Ibadan, Nigeria

    PubMed Central

    2014-01-01

    Background While induced abortion is considered to be illegal and socially unacceptable in Nigeria, it is still practiced by many women in the country. Poor family planning and unsafe abortion practices have daunting effects on maternal health. For instance, Nigeria is on the verge of not meeting the Millennium development goals on maternal health due to high maternal mortality ratio, estimated to be about 630 maternal deaths per 100,000 live births. Recent evidences have shown that a major factor in this trend is the high incidence of abortion in the country. The objective of this paper is, therefore, to investigate the factors determining the demand for abortion and post-abortion care in Ibadan city of Nigeria. Methods The study employed data from a hospital-based/exploratory survey carried out between March to September 2010. Closed ended questionnaires were administered to a sample of 384 women of reproductive age from three hospitals within the Ibadan metropolis in South West Nigeria. However, only 308 valid responses were received and analysed. A probit model was fitted to determine the socioeconomic factors that influence demand for abortion and post-abortion care. Results The results showed that 62% of respondents demanded for abortion while 52.3% of those that demanded for abortion received post-abortion care. The findings again showed that income was a significant determinant of abortion and post-abortion care demand. Women with higher income were more likely to demand abortion and post-abortion care. Married women were found to be less likely to demand for abortion and post-abortion care. Older women were significantly less likely to demand for abortion and post-abortion care. Mothers’ education was only statistically significant in determining abortion demand but not post-abortion care demand. Conclusion The findings suggest that while abortion is illegal in Nigeria, some women in the Ibadan city do abort unwanted pregnancies. The consequence of this

  9. The pollen enigma: modulation of the allergic immune response by non-allergenic, pollen-derived compounds.

    PubMed

    Gilles, Stefanie; Behrendt, Heidrun; Ring, Johannes; Traidl-Hoffmann, Claudia

    2012-01-01

    The question what makes an allergen an allergen puzzled generations of researchers. Pollen grains of anemophilous plants are the most important allergen carriers in ambient air, and pollinosis is a highly prevalent multi-organ disease in civilized countries. In the past, research on the allergenicity of pollen has mainly focused on elucidating genetic predisposing factors and on defining certain structural characteristics of pollen derived allergens. Recently, studies extended to the analysis of non-allergenic, adjuvant mediators co-released from pollen. Besides active proteases and oxidases, extracts of pollen contain low molecular weight molecules like pollen-associated lipid mediators or adenosine exhibiting a potential to stimulate and modulate cultured human immune cells. This article reviews our current knowledge on non-allergenic, protein and non-protein compounds from pollen and their in vitro and in vivo effects on the allergic immune response. To ultimately judge the physiological relevance of these compounds, a systematic approach will be needed comparing their releasability, content and activity in different, allergenic and non-allergenic, pollen species. System biology such as proteome and metabolome analysis will be a useful future approach to better understand pollen biology. PMID:22390694

  10. Dynamics of sulfate and nitrate dry deposition associated with pollen

    SciTech Connect

    Khalili, E.K.

    1988-01-01

    A field study of pollen dispersion and deposition from a remote forested area in Northern Wisconsin has been undertaken. Although the experiments constitute a case study in Wisconsin, the experimental site was chosen, which represents much of the Eastern US and Europe where acid rain is considered an important environmental problem. Measurements of dry deposition of pollen were made during the pollination season (May and June, 1987). Deposited particles were weighted to determine mass fluxes, then washed and subjected to ion chromatographic analysis for sulfate and nitrate. Ambient concentration of pollen were measured by a coarse particle sampler (Noll Inertial Rotary Impact) during the same time period. The chemical analysis of pollen species collected around the sampling site as well as commercially available pollen demonstrated that sulfate and nitrate were present on all pollen samples. Many trace metals such as Fe, Al, Zn, Cu, Mn, Cd, Pb, Ca, and Si and organic acids were quantified. It was hypothesized that pollen accumulate extraneous amounts of non-essential, as well as essential elements from the soil supplying nutrient. Therefore, pollen can be used as a fingerprint for the availability and the level of contamination of a particular element in the forest soil environment. A model developed for measurement of coarse particle dry deposition was utilized to measure the pollen dry deposition velocity. It was shown that depositional velocity of pollen exceeds the settling velocity by a factor of 3 to 4, and both V{sub d} and fluxes of pollen grains increase with wind speed. Finally, the role of pollen dispersion and deposition has been discussed and emphasized for modeling of lake acidification in forested region.

  11. 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.

  12. Abortion in Ghana.

    PubMed

    Sedgh, Gilda

    2010-07-01

    Maternal mortality is the second most common cause of death among women in Ghana, and more than one in 10 maternal deaths (11%) are the result of unsafe induced abortions.1 In addition, a substantial proportion of women who survive an unsafe abortion experience complications from the procedure. This suffering is all the more tragic because it is unnecessary: Many women likely turn to unsafe providers or do not obtain adequate postabortion care when it is needed because they are unaware that abortion is legal on fairly broad grounds in Ghana. PMID:20653094

  13. Utilization of pollen to examine insect foraging and movement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The outer wall of a pollen grain is called the exine and protects the genetic material located inside the grain from desiccation and radiation. It is made up largely of a complex molecule called sporopollenin, which is durable and does not easily decay. The exine also exhibits specific patterns wh...

  14. The ARID-HMG DNA-binding protein AtHMGB15 is required for pollen tube growth in Arabidopsis thaliana.

    PubMed

    Xia, Chuan; Wang, Yu-Jiao; Liang, Yan; Niu, Qian-Kun; Tan, Xiao-Yun; Chu, Liang-Cui; Chen, Li-Qun; Zhang, Xue-Qin; Ye, De

    2014-09-01

    In flowering plants, male gametes (sperm cells) develop within male gametophytes (pollen grains) and are delivered to female gametes for double fertilization by pollen tubes. Therefore, pollen tube growth is crucial for reproduction. The mechanisms that control pollen tube growth remain poorly understood. In this study, we demonstrated that the ARID-HMG DNA-binding protein AtHMGB15 plays an important role in pollen tube growth. This protein is preferentially expressed in pollen grains and pollen tubes and is localized in the vegetative nuclei of the tricellular pollen grains and pollen tubes. Knocking down AtHMGB15 expression via a Ds insertion caused retarded pollen tube growth, leading to a significant reduction in the seed set. The athmgb15-1 mutation affected the expression of 1686 genes in mature pollen, including those involved in cell wall formation and modification, cell signaling and cellular transport during pollen tube growth. In addition, it was observed that AtHMGB15 binds to DNA in vitro and interacts with the transcription factors AGL66 and AGL104, which are required for pollen maturation and pollen tube growth. These results suggest that AtHMGB15 functions in pollen tube growth through the regulation of gene expression. PMID:24923357

  15. [Interregional project concerning abortion].

    PubMed

    Jourdain, A; Pierotti, D; Vinclair, M

    1979-01-01

    The law legalizing abortion in France was passed in 1975. To group information of a social and medical nature and to publish reports on their activities, a questionnaire was designed to be filled by physicians and nurses working in centers and hospitals performing abortion. There were 19,000 abortions performed in 1976, and 30,000 are expected to be performed in 1979. The questionnaire contains 80 questions gathering information on socieconomic data, on medical history, on the procedure of the intervention, and on the follow-up visit. A study done on 5700 questionnaires filled between 1976 and 1977 show that most abortion seekers belong to the middle class, and that pregnancy was due in 20% of cases to pill failure, and in 34% of cases to failure of behavioral methods, or to lack of contraception. 88% of patients declared themselves satisfied with the procedure. PMID:12309432

  16. Induced abortion in Indonesia.

    PubMed

    Hull, T H; Sarwono, S W; Widyantoro, N

    1993-01-01

    Induced abortion is one of the most difficult sociomedical problems facing the Indonesian government. While well-known in traditional society, the practice was discouraged by all Indonesian religious groups, and forbidden by the Dutch colonial authorities. Although abortion was technically illegal under the criminal code, a judicial interpretation in the early 1970s permitted medical professionals to offer the procedure so long as they were discreet and careful. The numbers of medical abortions carried out in Indonesia rose dramatically, and there was evidence of matching declines in the incidence of morbidity and mortality caused by dangerous illegal procedures. Medical and community groups campaigned for a more liberal abortion law to protect legal practitioners and stamp out illegal traditional practices. Their efforts appeared to bear fruit in the draft Health Law, but when the law was passed by the legislature in late 1992, the issue was again clouded by contradictions and inconsistencies. PMID:8212094

  17. 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

  18. Botswana: abortion "debate" dynamics.

    PubMed

    Mogwe, A

    1992-01-01

    The Penal Code (Amendment) Bill or the abortion bill has the objective of liberalizing the current law on the regulation of abortion. Abortion had been strictly prohibited and carried stiff penalties. Anyone who attempted to assists a woman to procure an abortion could be liable to 7 years' imprisonment. However, medical abortions were distinguished as being medically determined to save the health of the mother. Demands for a reevaluation of the law came from the medical profession, and in response the Minister for Presidential Affairs submitted a bill to Parliament in November, 1990. The expressed government rationale for these proposed amendments was concern about the health of women. In Botswana about 200 women die yearly because of pregnancy. According to the proposed law: an abortion could be carried out within the first 16 weeks of pregnancy if: 1) the pregnancy were a result of rape, incest, or defilement (the impregnation of a girl aged 16 or less, the impregnation of imbeciles or idiots), 2) the physical or mental health of the woman were at risk because of the pregnancy, 3) the child would be born with a serious physical or mental abnormality. The abortion could be carried out only if 2 medical doctors approved it. The amendments fall far short of increasing women's control over their bodies. The Botswana Christian Council issued a statement early in the public debate. While it did not oppose the bill in its entirety, clear concern was expressed concerning the apparent right of determining who lives and who dies depending on the handicap of the child. This rather liberal position was challenged by the Roman Catholic Church which interpreted abortion as the murder of God-given life. The bill was nevertheless passed by Parliament in September 1991, and the President signed it on October 11, 1991. PMID:12288837

  19. 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. ...

  20. Germination of stress-tolerant Eucalyptus pollen.

    PubMed

    Heslop-Harrison, J; Heslop-Harrison, Y

    1985-02-01

    Earlier reports have indicated that the pollen of Eucalyptus is mechanically robust and unusually resistant to the osmotic stress imposed by immersion in water. We have investigated some of the features of the germination mechanism in the pollen of E. rhodantha with a view to clarifying the role of pollen-wall specializations in determining this resistance. Cultured in vitro, the pollen showed erratic germination, with a scatter of germination times up to 24 h. This was associated with variation between individual grains in the rate of hydration and dispersal of the pectins of the oncus, the thickened outer component of the intine present at each aperture. The oncus is itself differentiated, with a refractive outer layer lying within a sporopollenin operculum and itself overlying the protein-bearing layer of the intine. The outer layer, interpreted as a compacted pectin, undergoes only slow dissolution in aqueous media after the lifting of the operculum, and it is this that apparently protects the grain from the effects of short-term osmotic stress. The rate of dissolution varies between grains, possibly as a consequence of minor differences in developmental rate in the final stages of differentiation in the anther, and this contributes to the wider scatter of germination times. The dehydrated pollen gave one-third of the potential germination after 24 h exposure to 60 degrees C, and a small proportion survived 24 h at 70 degrees C. This degree of heat tolerance must primarily reflect properties of the protoplast of the vegetative cell, not examined in the present study; but the wall specializations may well provide a guard against extreme desiccation, and it is noteworthy that the function of the germination mechanism is not prejudiced by exposure to high temperatures. PMID:4019590

  1. AtTMEM18 plays important roles in pollen tube and vegetative growth in Arabidopsis.

    PubMed

    Dou, Xiao-Ying; Yang, Ke-Zhen; Ma, Zhao-Xia; Chen, Li-Qun; Zhang, Xue-Qin; Bai, Jin-Rong; Ye, De

    2016-07-01

    In flowering plants, pollen tube growth is essential for delivery of male gametes into the female gametophyte or embryo sac for double fertilization. Although many genes have been identified as being involved in the process, the molecular mechanisms of pollen tube growth remains poorly understood. In this study, we identified that the Arabidopsis Transmembrane Protein 18 (AtTMEM18) gene played important roles in pollen tube growth. The AtTMEM18 shares a high similarity with the Transmembrane 18 proteins (TMEM18s) that are conserved in most eukaryotes and may play important roles in obesity in humans. Mutation in the AtTMEM18 by a Ds insertion caused abnormal callose deposition in the pollen grains and had a significant impact on pollen germination and pollen tube growth. AtTMEM18 is expressed in pollen grains, pollen tubes, root tips and other vegetative tissues. The pollen-rescued assays showed that the mutation in AtTMEM18 also caused defects in roots, stems, leaves and transmitting tracts. AtTMEM18-GFP was located around the nuclei. Genetic assays demonstrated that the localization of AtTMEM18 around the nuclei in the generative cells of pollen grains was essential for the male fertility. Furthermore, expression of the rice TMEM18-homologous protein (OsTMEM18) driven by LAT52 promoter could recover the fertility of the Arabidopsis attmem18 mutant. These results suggested that the TMEM18 is important for plant growth in Arabidopsis. PMID:26699939

  2. Proteomic analysis of major and minor allergens from isolated pollen cytoplasmic granules.

    PubMed

    Abou Chakra, Oussama R; Sutra, Jean-Pierre; Demey Thomas, Emmanuelle; Vinh, Joëlle; Lacroix, Ghislaine; Poncet, Pascal; Sénéchal, Hélène

    2012-02-01

    Grass pollen is one of the most important vectors of aeroallergens. Under atmospheric conditions, pollen grains can release pollen cytoplasmic granules (PCGs). The allergens associated with these intrinsic subfractions induce, in laboratory animals as well as in asthmatic patients, allergic and inflammatory responses. The objectives of this study were to characterize the PCGs' intrinsic allergens and to compare them with those of pollen grains. The water-soluble proteins were extracted from pollen grains and their PCGs. IgE-binding proteins were analyzed and characterized through an allergomic strategy: 1- and 2-dimensional gel electrophoresis (1-DE and 2-DE), immunoblotting, using grass-pollen-sensitized patient sera, mass spectrometry (MS) analysis, and database searching. Several of the allergens listed in the IUIS nomenclature, Phl p 1, 4, 5, 6, and 12, were detected in pollen and PCG extracts, whereas Phl p 11 was found only in PCGs, and Phl p 2 as well as Phl p 13 were found only in pollen extract. Some other allergens not listed in the IUIS nomenclature were also characterized in both pollen and PCG extracts. Since the major grass pollen allergens were found in PCGs and because of their small size, these submicronic particles should be considered as very potent sensitizing and challenging respirable vectors of allergens. PMID:22188203

  3. 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.

  4. Secretory activity is rapidly induced in stigmatic papillae by compatible pollen, but inhibited for self-incompatible pollen in the Brassicaceae.

    PubMed

    Safavian, Darya; Goring, Daphne R

    2013-01-01

    [In the Brassicaceae, targeted exocytosis to the stigmatic papillar plasma membrane under the compatible pollen grain is hypothesized to be essential for pollen hydration and pollen tube penetration. In contrast, polarized secretion is proposed to be inhibited in the stigmatic papillae during the rejection of self-incompatible pollen. Using transmission electron microscopy (TEM), we performed a detailed time-course of post-pollination events to view the cytological responses of the stigmatic papillae to compatible and self-incompatible pollinations. For compatible pollinations in Arabidopsis thaliana and Arabidopsis lyrata, vesicle secretion was observed at the stigmatic papillar plasma membrane under the pollen grain while Brassica napus stigmatic papillae appeared to use multivesicular bodies (MVBs) for secretion. Exo70A1, a component of the exocyst complex, has been previously implicated in the compatible pollen responses, and disruption of Exo70A1 in both A. thaliana and B. napus resulted in a loss of secretory vesicles/MVBs at the stigmatic papillar plasma membrane. Similarly, for self-incompatible pollinations, secretory vesicles/MVBs were absent from the stigmatic papillar plasma membrane in A. lyrata and B. napus; and furthermore, autophagy appeared to be induced to direct vesicles/MVBs to the vacuole for degradation. Thus, these findings support a model where the basal pollen recognition pathway in the stigmatic papilla promotes exocytosis to accept compatible pollen, and the basal pollen recognition pathway is overridden by the self-incompatibility pathway to prevent exocytosis and reject self-pollen. PMID:24386363

  5. Secretory Activity Is Rapidly Induced in Stigmatic Papillae by Compatible Pollen, but Inhibited for Self-Incompatible Pollen in the Brassicaceae

    PubMed Central

    Safavian, Darya; Goring, Daphne R.

    2013-01-01

    [In the Brassicaceae, targeted exocytosis to the stigmatic papillar plasma membrane under the compatible pollen grain is hypothesized to be essential for pollen hydration and pollen tube penetration. In contrast, polarized secretion is proposed to be inhibited in the stigmatic papillae during the rejection of self-incompatible pollen. Using transmission electron microscopy (TEM), we performed a detailed time-course of post-pollination events to view the cytological responses of the stigmatic papillae to compatible and self-incompatible pollinations. For compatible pollinations in Arabidopsis thaliana and Arabidopsis lyrata, vesicle secretion was observed at the stigmatic papillar plasma membrane under the pollen grain while Brassica napus stigmatic papillae appeared to use multivesicular bodies (MVBs) for secretion. Exo70A1, a component of the exocyst complex, has been previously implicated in the compatible pollen responses, and disruption of Exo70A1 in both A. thaliana and B. napus resulted in a loss of secretory vesicles/MVBs at the stigmatic papillar plasma membrane. Similarly, for self-incompatible pollinations, secretory vesicles/MVBs were absent from the stigmatic papillar plasma membrane in A. lyrata and B. napus; and furthermore, autophagy appeared to be induced to direct vesicles/MVBs to the vacuole for degradation. Thus, these findings support a model where the basal pollen recognition pathway in the stigmatic papilla promotes exocytosis to accept compatible pollen, and the basal pollen recognition pathway is overridden by the self-incompatibility pathway to prevent exocytosis and reject self-pollen. PMID:24386363

  6. 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.

  7. Automated pollen identification using microscopic imaging and texture analysis.

    PubMed

    Marcos, J Víctor; Nava, Rodrigo; Cristóbal, Gabriel; Redondo, Rafael; Escalante-Ramírez, Boris; Bueno, Gloria; Déniz, Óscar; González-Porto, Amelia; Pardo, Cristina; Chung, François; Rodríguez, Tomás

    2015-01-01

    Pollen identification is required in different scenarios such as prevention of allergic reactions, climate analysis or apiculture. However, it is a time-consuming task since experts are required to recognize each pollen grain through the microscope. In this study, we performed an exhaustive assessment on the utility of texture analysis for automated characterisation of pollen samples. A database composed of 1800 brightfield microscopy images of pollen grains from 15 different taxa was used for this purpose. A pattern recognition-based methodology was adopted to perform pollen classification. Four different methods were evaluated for texture feature extraction from the pollen image: Haralick's gray-level co-occurrence matrices (GLCM), log-Gabor filters (LGF), local binary patterns (LBP) and discrete Tchebichef moments (DTM). Fisher's discriminant analysis and k-nearest neighbour were subsequently applied to perform dimensionality reduction and multivariate classification, respectively. Our results reveal that LGF and DTM, which are based on the spectral properties of the image, outperformed GLCM and LBP in the proposed classification problem. Furthermore, we found that the combination of all the texture features resulted in the highest performance, yielding an accuracy of 95%. Therefore, thorough texture characterisation could be considered in further implementations of automatic pollen recognition systems based on image processing techniques. PMID:25259684

  8. Spatial and temporal modeling of daily pollen concentrations

    NASA Astrophysics Data System (ADS)

    Dellavalle, Curt T.; Triche, Elizabeth W.; Bell, Michelle L.

    2012-01-01

    Accurate assessments of pollen counts are valuable to allergy sufferers, the medical industry, and health researchers; however, monitoring stations do not exist in most areas. In addition, the degree of spatial reliability provided by the limited number of monitoring stations is poorly understood. We developed and compared spatial models to estimate pollen concentrations in locations without monitoring stations. Daily Acer, Quercus, and overall tree, grass, and weed pollen counts, in grains/m3, were obtained from 14 aeroallergen monitoring stations located in the northeastern and mid-Atlantic region of the United States from 2003 to 2006. Pollen counts were spatially interpolated using ordinary kriging. Mixed effects and generalized estimating equations incorporating daily and seasonal weather characteristics, pollen season characteristics and land-cover information were also developed to estimate daily pollen concentrations. We then compared observed values from a monitoring station to model estimates for that location. Observed counts and kriging estimates for tree pollen differed ( p = 0.04), but not when peak periods were removed ( p = 0.29). No differences between observed and kriging estimates of Acer ( p = 0.46), Quercus ( p = 0.24), grass ( p = 0.31) or weed pollen ( p = 0.29) were found. Estimates from longitudinal models also demonstrated good agreement with observed counts, except for the extremes of pollen distributions. Our results demonstrate that spatial interpolation techniques as well as regression methods incorporating both weather and land-cover characteristics can provide reliable estimates of daily pollen concentrations in areas where monitors do not exist for all but periods of extremely high pollen.

  9. Pollen embryogenesis to induce, detect, and analyze mutants

    SciTech Connect

    Constantin, M.J.

    1981-01-01

    The development of fully differentiated plants from individual pollen grains through a series of developmental phases that resemble embryogenesis beginning with the zygote was demonstrated during the mid-1960's. This technology opened the door to the use of haploid plants (sporophytes with the gametic number of chromosomes) for plant breeding and genetic studies, biochemical and metabolic studies, and the selection of mutations. Although pollen embryogenesis has been demonstrated successfully in numerous plant genera, the procedure cannot as yet be used routinely to generate large populations of plants for experiments. Practical results from use of the technology in genetic toxicology research to detect mutations have failed to fully realize the theoretical potential; further developments of the technology could overcome the limitations. Pollen embryogenesis could be used to develop plants from mutant pollen grains to verify that genetic changes are involved. Through either spontaneous or induced chromosome doubling, these plants can be made homozygous and used to analyze genetically the mutants involved. The success of this approach will depend on the mutant frequency relative to the fraction of pollen grains that undergo embryogenesis; these two factors will dictate population size needed for success. Research effort is needed to further develop pollen embryogenesis for use in the detection of genotoxins under both laboratory and in situ conditions.

  10. Pollen embryogenesis to induce, detect, and analyze mutants.

    PubMed Central

    Constantin, M J

    1981-01-01

    The development of fully differentiated plants from individual pollen grains through a series of developmental phases that resemble embryogenesis beginning with the zygote was demonstrated during the mid-1960's. This technology opened the door to the use of haploid plants (sporophytes with the gametic number of chromosomes) for plant breeding and genetic studies, biochemical and metabolic studies, and the selection of mutations. Although pollen embryogenesis has been demonstrated successfully in numerous plant genera, the procedure cannot as yet be used routinely to generate large populations of plants for experiments. Practical results from use of the technology in genetic toxicology research to detect mutations have failed to fully realize the theoretical potential; further developments of the technology could overcome the limitations. Pollen embryogenesis could be used to develop plants from mutant pollen grains to verify that genetic changes are involved. Through either spontaneous or induced chromosome doubling, these plants can be made homozygous and used to analyze genetically the mutants involved. The success of this approach will depend on the mutant frequency relative to the fraction of pollen grains that undergo embryogenesis; these two factors will dictate population size needed for success. Research effort is needed to further develop pollen embryogenesis for use in the detection of genotoxins under both laboratory and in situ conditions. PMID:7460882

  11. Pollen tube growth: where does the energy come from?

    PubMed Central

    Selinski, Jennifer; Scheibe, Renate

    2014-01-01

    This review focuses on the energy metabolism during pollen maturation and tube growth and updates current knowledge. Pollen tube growth is essential for male reproductive success and extremely fast. Therefore, pollen development and tube growth are high energy-demanding processes. During the last years, various publications (including research papers and reviews) emphasize the importance of mitochondrial respiration and fermentation during male gametogenesis and pollen tube elongation. These pathways obviously contribute to satisfy the high energy demand, and there are many studies which suggest that respiration and fermentation are the only pathways to generate the needed energy. Here, we review data which show for the first time that in addition plastidial glycolysis and the balancing of the ATP/NAD(P)H ratio (by malate valves and NAD+ biosynthesis) contribute to satisfy the energy demand during pollen development. Although the importance of energy generation by plastids was discounted during the last years (possibly due to the controversial opinion about their existence in pollen grains and pollen tubes), the available data underline their prime role during pollen maturation and tube growth. PMID:25482752

  12. 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

  13. Limnic sediments and the taphonomy of Lateglacial pollen assemblages

    NASA Astrophysics Data System (ADS)

    Pennington, Winifred; Tutin, T. G.

    Pollen taphonomy, defined by R.G. West in 1973 as "the processes which govern the production of fossil (pollen) assemblages from living vegetation", introduces an additional variable into the pollen/vegetation relationship. Changes in taphonomic factors, of the kind to be expected within cold-stage Quaternary environments, may influence the composition of pollen assemblages, producing variations between them in space and time which are not directly related to variation in vegetation. Comparisons between sites — 35 Lateglacial (Late Devensian) lake sediment profiles within a 40 × 40 km region of high relief — are used to identify situations where anomalies in pollen values can be attributed to taphonomic factors. Processes involved include: redeposition of older pollen from soils (recycling) during episodes of increased instability of the land surface; spatial differentiation in deposition of sediment and pollen within the larger lakes, associated with a within-lake water circulation very different from today's; selective recruitment of pollen taxa by glacial meltwater; a) of Salix by outlet streams from small glaciers associated with favourable habitats for willows, and b) of Pinus from grains trapped by extensive mountain snowfields and larger glaciers.

  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 morphology and plant taxonomy of white oaks in eastern North America

    SciTech Connect

    Solomon, A.M.

    1983-04-01

    An evaluation of possible approaches to fossil oak pollen identification utilized scanning electron microscopy to examine exine-surface features of 171 collections, representing 16 Quercus subgenus Lepidobalanus species and varieties of eastern North America. Twenty qualitative pollen morphological characters were defined and tabulated for each of 217 pollen grains. The data were subjected to cluster analysis and cluster diagrams were compared with published white oak taxonomy. Pollen morphology and plant taxonomy compared well in series of the subgenus Lepidobalanus due primarily to consistency of character presence and absence within species and varieties. Pollen morphology of white oaks appears to reflect plant systematics above the species level. Use of routine SEM analysis to identify series of white oaks among fossil pollen grains likely will yield valid results. 38 references.

  16. Current technology for abortion.

    PubMed

    Stubblefield, P G

    1978-12-01

    This discussion focuses on the presently available technology of abortion induction techniques, which, though recent scientific interest has been in abortifacient agents, still primarily consists of some variation on the ancient technique of forcible cervical dilatation and pregnancy extraction in the first trimester. With the advent of legal abortions in the United States, technology and expertise that will lower the already low rate of abortion-associated complications are of paramount importance. That abortion may be preferable to contraception as a fertility control measure is argued from the following 3 drawbacks of present means of contraception: 1) they are preventitive and must be used in advance of need; 2) they fail more frequently than is usually thought (e.g., 4% for birth control pills, 5% for IUDs, and from 17-21% for more conventional methods); and 3) they are associated, though rarely, with potentially fatal side effects such as heart attack, stroke, or infection (some also raise the incidence of pathological pregnancies). The article devotes itself to an overview of complications of induced abortions (the mortality for legal abortions is 1/100,000 vs. maternal mortality of 10/100,000 in the United States), and to discussions of appropriate evacuation procedures per gestational age. Instruments and techniques for menstrual regulation (uterine aspiration during first trimester), are discussed. Procedures and instrumentation required for standard vacuum aspiration are covered. Use of analgesics and anesthetics during abortion procedures comprises one topic, with especial focus on the use of curettage for midtrimester terminations. Midtrimester terminations by amnioinfusions of abortifacients (saline, urea, and prostaglandins, e.g.) are analyzed. And, in addition to discussing sequelae for each particular abortion type, a section is devoted to the sequelae of induced abortion for subsequent pregnancy. Though 100% effectiveness has not been achieved yet

  17. 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.

  18. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination

    PubMed Central

    Rejón, Juan D.; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J.

    2012-01-01

    Background and Aims A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. Methods The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Key Results Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. Conclusions In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of

  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. 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

  1. The Response of Abortion Demand to Changes in Abortion Costs

    ERIC Educational Resources Information Center

    Medoff, Marshall H.

    2008-01-01

    This study uses pooled cross-section time-series data, over the years 1982, 1992 and 2000, to estimate the impact of various restrictive abortion laws on the demand for abortion. This study complements and extends prior research by explicitly including the price of obtaining an abortion in the estimation. The empirical results show that the real…

  2. Unsafe abortion and abortion care in Khartoum, Sudan.

    PubMed

    Kinaro, Joyce; Ali, Tag Elsir Mohamed; Schlangen, Rhonda; Mack, Jessica

    2009-11-01

    Unsafe abortion in Sudan results in significant morbidity and mortality. This study of treatment for complications of unsafe abortion in five hospitals in Khartoum, Sudan, included a review of hospital records and a survey of 726 patients seeking abortion-related care from 27 October 2007 to 31 January 2008, an interview of a provider of post-abortion care and focus group discussions with community leaders. Findings demonstrate enormous unmet need for safe abortion services. Abortion is legally restricted in Sudan to circumstances where the woman's life is at risk or in cases of rape. Post-abortion care is not easily accessible. In a country struggling with poverty, internal displacement, rural dwelling, and a dearth of trained doctors, mid-level providers are not allowed to provide post-abortion care or prescribe contraception. The vast majority of the 726 abortion patients in the five hospitals were treated with dilatation and curettage (D&C), and only 12.3% were discharged with a contraceptive method. Some women waited long hours before treatment was provided; 14.5% of them had to wait for 5-8 hours and 7.3% for 9-12 hours. Mid-level providers should be trained in safe abortion care and post-abortion care to make these services accessible to a wider community in Sudan. Guidelines should be developed on quality of care and should mandate the use of manual vacuum aspiration or misoprostol for medical abortion instead of D&C. PMID:19962640

  3. A compromise on abortion?

    PubMed

    Rhoden, N K

    1989-01-01

    Rhoden's article is one of three on "Abortion: searching for common ground" in this issue of the Hastings Center Report. Her article, together with those by M. Mahowald and M. Glendon, was prompted by the expectation that the impending U.S. Supreme Court decision in Webster v. Reproductive Health Services (3 July 1989) would overturn or restrict Roe v. Wade (1973). Rhoden, an advocate for the pro-choice position, asks whether a compromise leading to an acceptable regulatory policy is possible or desirable among those on opposite sides of the abortion issue. She identifies several reasons why the Roe decision is vulnerable to review, but argues that effective education about sexuality and comprehensive social support of women are better approaches to abortion than restrictive legislation. PMID:2663778

  4. Abortion and human rights.

    PubMed

    Shaw, Dorothy

    2010-10-01

    Abortion has been a reality in women's lives since the beginning of recorded history, typically with a high risk of fatal consequences, until the last century when evolutions in the field of medicine, including techniques of safe abortion and effective methods of family planning, could have ended the need to seek unsafe abortion. The context of women's lives globally is an important but often ignored variable, increasingly recognised in evolving human rights especially related to gender and reproduction. International and regional human rights instruments are being invoked where national laws result in violations of human rights such as health and life. The individual right to conscientious objection must be respected and better understood, and is not absolute. Health professional organisations have a role to play in clarifying responsibilities consistent with national laws and respecting reproductive rights. Seeking common ground using evidence rather than polarised opinion can assist the future focus. PMID:20303830

  5. [Spontaneous abortion. Etiologic survey. Results].

    PubMed

    Baaklini, N; Anguenot, J L; Boulanger, J C; Vitse, M

    1990-12-01

    The definition of repeated spontaneous abortions is subject to caution. For some, it corresponds to at least three repeated spontaneous abortions with no normal previous pregnancy; for others, it comprises the repeated spontaneous abortions occurring after a normal pregnancy. It is a frequent problem, especially if one tries to give a wider definition. The authors studied the frequency of repeated spontaneous abortions in a continuous series of 14,857 pregnancies which took place between January 1982 and December 1988. In the study of the aetiology of the repeated spontaneous abortions in the various groups of women defined according to the number of previous pregnancies and abortions, they find the classical causes of repeated spontaneous abortions in all the categories: therefore, it seems legitimate to them that a wider definition be given for repeated spontaneous abortions. PMID:2291048

  6. 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

  7. The pollen organelle membrane proteome reveals highly spatial-temporal dynamics during germination and tube growth of lily pollen.

    PubMed

    Pertl, Heidi; Schulze, Waltraud X; Obermeyer, Gerhard

    2009-11-01

    As a first step in understanding the membrane-related dynamics during pollen grain germination and subsequent tube growth, the changes in protein abundance of membrane and membrane-associated proteins of 5 different membrane/organelle fractions were studied at physiologically important stages (0, 10, 30, 60, and 240 min) of Lilium longiflorum pollen in vitro culture. Proteins of each fraction and time point were identified by 'shot-gun' proteomics (LC-MS/MS). Analysis of more than 270 identified proteins revealed an increase in the abundance of proteins involved in cytoskeleton, carbohydrate and energy metabolism, as well as ion transport before pollen grain germination (10-30 min), whereas proteins involved in membrane/protein trafficking, signal transduction, stress response and protein biosynthesis decreased in abundance during this time. Proteins of amino acids and lipids/steroids metabolism, proteolysis, transcription, cell wall biosynthesis as well as nutrient transport showed a time-independent abundance profile. These spatiotemporal patterns were confirmed by immunodetection of specific proteins of the cellular processes membrane/protein trafficking and ion transport. Our results reveal major protein rearrangements at endomembranes and the plasma membrane before and as the pollen grains start tube growth. The spatiotemporal protein abundance changes correlate with the underlying developmental and physiological processes of the germinating pollen grain. PMID:19799449

  8. Apollo experience report: Abort planning

    NASA Technical Reports Server (NTRS)

    Hyle, C. T.; Foggatt, C. E.; Weber, B. D.

    1972-01-01

    Definition of a practical return-to-earth abort capability was required for each phase of an Apollo mission. A description of the basic development of the complex Apollo abort plan is presented. The process by which the return-to-earth abort plan was developed and the constraining factors that must be included in any abort procedure are also discussed. Special emphasis is given to the description of crew warning and escape methods for each mission phase.

  9. Space Shuttle Abort Evolution

    NASA Technical Reports Server (NTRS)

    Henderson, Edward M.; Nguyen, Tri X.

    2011-01-01

    This paper documents some of the evolutionary steps in developing a rigorous Space Shuttle launch abort capability. The paper addresses the abort strategy during the design and development and how it evolved during Shuttle flight operations. The Space Shuttle Program made numerous adjustments in both the flight hardware and software as the knowledge of the actual flight environment grew. When failures occurred, corrections and improvements were made to avoid a reoccurrence and to provide added capability for crew survival. Finally some lessons learned are summarized for future human launch vehicle designers to consider.

  10. Orion Abort Flight Test

    NASA Technical Reports Server (NTRS)

    Hayes, Peggy Sue

    2010-01-01

    The purpose of NASA's Constellation project is to create the new generation of spacecraft for human flight to the International Space Station in low-earth orbit, the lunar surface, as well as for use in future deep-space exploration. One portion of the Constellation program was the development of the Orion crew exploration vehicle (CEV) to be used in spaceflight. The Orion spacecraft consists of a crew module, service module, space adapter and launch abort system. The crew module was designed to hold as many as six crew members. The Orion crew exploration vehicle is similar in design to the Apollo space capsules, although larger and more massive. The Flight Test Office is the responsible flight test organization for the launch abort system on the Orion crew exploration vehicle. The Flight Test Office originally proposed six tests that would demonstrate the use of the launch abort system. These flight tests were to be performed at the White Sands Missile Range in New Mexico and were similar in nature to the Apollo Little Joe II tests performed in the 1960s. The first flight test of the launch abort system was a pad abort (PA-1), that took place on 6 May 2010 at the White Sands Missile Range in New Mexico. Primary flight test objectives were to demonstrate the capability of the launch abort system to propel the crew module a safe distance away from a launch vehicle during a pad abort, to demonstrate the stability and control characteristics of the vehicle, and to determine the performance of the motors contained within the launch abort system. The focus of the PA-1 flight test was engineering development and data acquisition, not certification. In this presentation, a high level overview of the PA-1 vehicle is given, along with an overview of the Mobile Operations Facility and information on the White Sands tracking sites for radar & optics. Several lessons learned are presented, including detailed information on the lessons learned in the development of wind

  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. Identification and localization of a caleosin in olive (Olea europaea L.) pollen during in vitro germination

    PubMed Central

    Zienkiewicz, Krzysztof; Castro, Antonio J.; de Dios Alché, Juan; Zienkiewicz, Agnieszka; Suárez, Cynthia; Rodríguez-García, María Isabel

    2010-01-01

    In plant organs and tissues, the neutral storage lipids are confined to discrete spherical organelles called oil bodies. Oil bodies from plant seeds contain 0.6–3% proteins, including oleosins, steroleosins, and caleosins. In this study, a caleosin isoform of ∼30 kDa was identified in the olive pollen grain. The protein was mainly located at the boundaries of the oil bodies in the cytoplasm of the pollen grain and the pollen tube. In addition, caleosins were also visualized in the cytoplasm at the subapical zone, as well as in the tonoplast of vacuoles present in the pollen tube cytoplasm. The cellular behaviour of lipid bodies in the olive pollen was also monitored during in vitro germination. The number of oil bodies decreased 20-fold in the pollen grain during germination, whereas the opposite tendency occurred in the pollen tube, suggesting that oil bodies moved from one to the other. The data suggest that this pollen caleosin might have a role in the mobilization of oil bodies as well as in the reorganization of membrane compartments during pollen in vitro germination. PMID:20164143

  13. 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

  14. Did Legalized Abortion Lower Crime?

    ERIC Educational Resources Information Center

    Joyce, Ted

    2004-01-01

    Changes in homicide and arrest rates were compared among cohorts born before and after legalization of abortion and those who were unexposed to legalized abortion. It was found that legalized abortion improved the lives of many women as they could avoid unwanted births.

  15. Abortion and compelled physician speech.

    PubMed

    Orentlicher, David

    2015-01-01

    Informed consent mandates for abortion providers may infringe the First Amendment's freedom of speech. On the other hand, they may reinforce the physician's duty to obtain informed consent. Courts can promote both doctrines by ensuring that compelled physician speech pertains to medical facts about abortion rather than abortion ideology and that compelled speech is truthful and not misleading. PMID:25846035

  16. RNA-Seq of Aradopsis pollen uncovers novel transcription and alternative splicing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollen grains of Arabidopsis (Arabidopsis thaliana) contain two haploid sperm cells enclosed in a haploid vegetative cell. Upon germination, the vegetative cell extrudes a pollen tube that carries the sperm to an ovule for fertilization. Knowing the identity, relative abundance, and splicing pattern...

  17. A mitochondrial DNA sequence is associated with abnormal pollen development in cytoplasmic male sterile bean plants.

    PubMed Central

    Johns, C; Lu, M; Lyznik, A; Mackenzie, S

    1992-01-01

    Cytoplasmic male sterility (CMS) in common bean is associated with the presence of a 3-kb unique mitochondrial sequence designated pvs. The pvs sequence encodes at least two open reading frames (297 and 720 bp in length) with portions derived from the chloroplast genome. Fertility restoration by the nuclear restorer gene Fr results in the loss of this transcriptionally active unique region. We examined the effect of CMS (pvs present) and fertility restoration by Fr (pvs absent) on the pattern of pollen development in bean. In the CMS line, pollen aborted in the tetrad stage late in microgametogenesis. Microspores maintained cytoplasmic connections throughout pollen development, indicating aberrant or incomplete cytokinesis. Pollen-specific events associated with pollen abortion and fertility restoration imply that a gametophytic factor or event may be involved in CMS. In situ hybridization experiments suggested that significant reduction or complete loss of the mitochondrial sterility-associated sequence occurred in fertile pollen of F2 populations segregating for fertility. These observations support a model of fertility restoration by the loss of a mitochondrial DNA sequence prior to or during microsporogenesis/gametogenesis. PMID:1498602

  18. 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

  19. Lipids in pollen - They are different.

    PubMed

    Ischebeck, Till

    2016-09-01

    During evolution, the male gametophyte of Angiosperms has been severely reduced to the pollen grain, consisting of a vegetative cell containing two sperm cells. This vegetative cell has to deliver the sperm cells from the stigma through the style to the ovule. It does so by producing a pollen tube and elongating it to many centimeters in length in some species, requiring vast amounts of fatty acid and membrane lipid synthesis. In order to optimize this polar tip growth, a unique lipid composition in the pollen has evolved. Pollen tubes produce extraplastidial galactolipids and store triacylglycerols in lipid droplets, probably needed as precursors of glycerolipids or for acyl editing. They also possess special sterol and sphingolipid moieties that might together form microdomains in the membranes. The individual lipid classes, the proteins involved in their synthesis as well as the corresponding Arabidopsis knockout mutant phenotypes are discussed in this review. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27033152

  20. Effects of acidity on tree pollen germination and tube growth

    SciTech Connect

    Jacobson, J.S.; Van Rye, D.M.; Lassoie, J.P.

    1985-01-01

    Several studies have indicated that pollen germination and tube growth are adversely affected by air pollutants. Pollutants may inhibit the function of pollen by reducing the number of pollen grains which germinate, by reducing the maximum length to which the pollen tubes grow, or by interfering with the formation of the generative cell. The paper reports on studies that are attempting to determine the effects acid rain may have on these crucial stages in the life histories of northeastern tree species. The first stage of this work assessed the effects of acidity in the growth medium on in vitro pollen germination for four deciduous forest species common to central New York State, Betula lutea (yellow birch), B. lenta (black birch), Acer saccharum (sugar maple), and Cornus florida (flowering dogwood). Measurements were taken at the end of the growth period to determine the percentage of grains which had germinated, and to estimate the average tube length. To determine the effects of pollen on the growth medium, the pH of the germination drop was measured at the end of the growth period.

  1. 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

  2. [Abortion and conscientious objection].

    PubMed

    Czarkowski, Marek

    2015-03-01

    Polish laws specify the parties responsible for lawful medical care in the availability of abortion differently than the Resolution of the Council of Europe. According to Polish regulations they include all Polish doctors while according to the Resolution, the state. Polish rules should not discriminate against anyone in connection with his religion or belief, even more so because the issue of abortion is an example of an unresolved ethical dispute. The number of lawful abortion in Poland does not exceed 1000 per year and can be carried out by only a few specialists contracted by the National Health Fund. Sufficient information and assistance should be provided to all pregnant women by the National Health Fund. The participation of all physicians in the informing process is not necessary, as evidenced by the lack of complaints to provide information on where in vitro fertilization treatment can be found - until recently only available when paid for by the individual and performed in much larger numbers than abortion. Entities performing this paid procedure made sure to provide information on their own. The rejection of the right to the conscientious objection clause by negating the right to refuse information may lead some to give up the profession or cause the termination of certain professionals on the basis of the professed worldview. Meanwhile, doctors are not allowed to be discriminated against on the basis of their conscience or religion. PMID:25815623

  3. Roundtable: Legal Abortion

    ERIC Educational Resources Information Center

    Guttmacher, Alan F.; And Others

    1971-01-01

    A roundtable discussion on legal abortion includes Dr. Alan F. Guttmacher, President of The Planned Parenthood Federation of America, Robert Hall, Associate Professor of Obstetrics and Gynecology at Columbia University College of Physicians and Surgeons, Christopher Tietze, a diretor of The Population Council, and Harriet Pilpel, a lawyer.…

  4. 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).

  5. 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.

  6. Observations on abortion in Zambia.

    PubMed

    Castle, M A; Likwa, R; Whittaker, M

    1990-01-01

    This report describes the findings of a preliminary investigation of women who sought treatment for abortion from the Gynecological Emergency Ward at the University Teaching Hospital (UTH) in Lusaka, Zambia. Barriers to obtaining legal abortions are identified and the harsh experiences of women seeking treatment for complications of illegally induced abortion are discussed. The data contribute to an understanding of the intensity of abortion for Zambian women and draw attention to the value of small-scale, qualitative research on women's reproductive health care needs. It is suggested that a study be planned at UTH to determine how health care delivery can be improved for women who seek abortion. PMID:2219228

  7. 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

  8. Fullerene-Based Symmetry in Hibiscus rosa-sinensis Pollen

    PubMed Central

    Andrade, Kleber; Guerra, Sara; Debut, Alexis

    2014-01-01

    The fullerene molecule belongs to the so-called super materials. The compound is interesting due to its spherical configuration where atoms occupy positions forming a mechanically stable structure. We first demonstrate that pollen of Hibiscus rosa-sinensis has a strong symmetry regarding the distribution of its spines over the spherical grain. These spines form spherical hexagons and pentagons. The distance between atoms in fullerene is explained applying principles of flat, spherical, and spatial geometry, based on Euclid’s “Elements” book, as well as logic algorithms. Measurements of the pollen grain take into account that the true spine lengths, and consequently the real distances between them, are measured to the periphery of each grain. Algorithms are developed to recover the spatial effects lost in 2D photos. There is a clear correspondence between the position of atoms in the fullerene molecule and the position of spines in the pollen grain. In the fullerene the separation gives the idea of equal length bonds which implies perfectly distributed electron clouds while in the pollen grain we suggest that the spines being equally spaced carry an electrical charge originating in forces involved in the pollination process. PMID:25003375

  9. 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

  10. 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

  11. RNA Silencing of Exocyst Genes in the Stigma Impairs the Acceptance of Compatible Pollen in Arabidopsis.

    PubMed

    Safavian, Darya; Zayed, Yara; Indriolo, Emily; Chapman, Laura; Ahmed, Abdalla; Goring, Daphne R

    2015-12-01

    Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We hypothesized that EXO70A1, along with other exocyst subunits, functions in the Brassicaceae dry stigma to deliver cargo-bearing secretory vesicles to the stigmatic papillar plasma membrane, under the pollen attachment site, for pollen hydration and pollen tube entry. Here, we investigated the functions of exocyst complex genes encoding the remaining seven subunits, SECRETORY3 (SEC3), SEC5, SEC6, SEC8, SEC10, SEC15, and EXO84, in Arabidopsis stigmas following compatible pollinations. Stigma-specific RNA-silencing constructs were used to suppress the expression of each exocyst subunit individually. The early postpollination stages of pollen grain adhesion, pollen hydration, pollen tube penetration, seed set, and overall fertility were analyzed in the transgenic lines to evaluate the requirement of each exocyst subunit. Our findings provide comprehensive evidence that all eight exocyst subunits are necessary in the stigma for the acceptance of compatible pollen. Thus, this work implicates a fully functional exocyst complex as a component of the compatible pollen response pathway to promote pollen acceptance. PMID:26443677

  12. The Pannonian plain as a source of Ambrosia pollen in the Balkans.

    PubMed

    Sikoparija, B; Smith, M; Skjøth, C A; Radisić, P; Milkovska, S; Simić, S; Brandt, J

    2009-05-01

    This study aims to find likely sources of Ambrosia pollen recorded during 2007 at five pollen-monitoring sites in central Europe: Novi Sad, Ruma, Negotin and Nis (Serbia) and Skopje (Macedonia). Ambrosia plants start flowering early in the morning and so Ambrosia pollen grains recorded during the day are likely to be from a local source. Conversely, Ambrosia pollen grains recorded at night or very early in the morning may have arrived via long-range transport. Ambrosia pollen counts were analysed in an attempt to find possible sources of the pollen and to identify Ambrosia pollen episodes suitable for further investigation using back-trajectory analysis. Diurnal variations and the magnitude of Ambrosia pollen counts during the 2007 Ambrosia pollen season showed that Novi Sad and Ruma (Pannonian Plain) and to a lesser degree Negotin (Balkans) were located near to sources of Ambrosia pollen. Mean bi-hourly Ambrosia pollen concentrations peaked during the middle of the day, and concentrations at these sites were notably higher than at Nis and Skopje. Three episodes were selected for further analysis using back-trajectory analysis. Back-trajectories showed that air masses brought Ambrosia pollen from the north to Nis and, on one occasion, to Skopje (Balkans) during the night and early morning after passing to the east of Novi Sad and Ruma during the previous day. The results of this study identified the southern part of the Pannonian Plain around Novi Sad and Ruma as being a potential source region for Ambrosia pollen recorded at Nis and Skopje in the Balkans. PMID:19224251

  13. Abortion health services in Canada

    PubMed Central

    Norman, Wendy V.; Guilbert, Edith R.; Okpaleke, Christopher; Hayden, Althea S.; Steven Lichtenberg, E.; Paul, Maureen; White, Katharine O’Connell; Jones, Heidi E.

    2016-01-01

    Abstract Objective To determine the location of Canadian abortion services relative to where reproductive-age women reside, and the characteristics of abortion facilities and providers. Design An international survey was adapted for Canadian relevance. Public sources and professional networks were used to identify facilities. The bilingual survey was distributed by mail and e-mail from July to November 2013. Setting Canada. Participants A total of 94 abortion facilities were identified. Main outcome measures The number and location of services were compared with the distribution of reproductive-age women by location of residence. Results We identified 94 Canadian facilities providing abortion in 2012, with 48.9% in Quebec. The response rate was 83.0% (78 of 94). Facilities in every jurisdiction with services responded. In Quebec and British Columbia abortion services are nearly equally present in large urban centres and rural locations throughout the provinces; in other Canadian provinces services are chiefly located in large urban areas. No abortion services were identified in Prince Edward Island. Respondents reported provision of 75 650 abortions in 2012 (including 4.0% by medical abortion). Canadian facilities reported minimal or no harassment, in stark contrast to American facilities that responded to the same survey. Conclusion Access to abortion services varies by region across Canada. Services are not equitably distributed in relation to the regions where reproductive-age women reside. British Columbia and Quebec have demonstrated effective strategies to address disparities. Health policy and service improvements have the potential to address current abortion access inequity in Canada. These measures include improved access to mifepristone for medical abortion; provincial policies to support abortion services; routine abortion training within family medicine residency programs; and increasing the scope of practice for nurses and midwives to include abortion

  14. A cytological study of anther and pollen development in Camellia oleifera.

    PubMed

    Gao, C; Yuan, D Y; Wang, B F; Yang, Y; Liu, D M; Han, Z Q

    2015-01-01

    The plant species Camellia oleifera is an important producer of edible oil in China. However, it suffers from a low fruit-setting rate. This study used high resolution scanning electron microscopy of semi-thin tissue sections to investigate anther development and pollen formation, and to determine whether problems in forming functional pollen cause low seed setting rates. During anther development, cell sizes within the epidermis and end othecium gradually increase, and at the beginning of the microsporocyte phase, the cells become highly vacuolated. The cell walls of the inner wall cells thicken in a ribbon pattern during the later part of the two-cell pollen stage. Middle layer cells become flattened during the later part of the secondary sporogenous cell stage. A tapetum also forms at this stage; the secondary sporogenous cells begin to degrade at the early microspore stage and completely disappear by the time the pollen is mature, thus forming a glandular tapetum. In microsporocyte, cytokinesis occurs simultaneously with microsporocyte meiosis, and a tetrahedral arrangement is present in tetrads. Reproductive cells begin to form at the later stage of microsporogenesis; the nuclei of the reproductive cells are enlarged as the reproductive cells begin to move away from the pollen wall. Two-cell pollen is first formed after reproductive cells have left the pollen wall, and the number of inclusions in the pollen subsequently increases. The pollen matures for 5-8 days before flowering occurs. No pollen abortion phenomena were observed, suggesting that anther development in C. oleifera is normal and that functional pollen are formed. PMID:26345807

  15. 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

  16. The consequences of abortion legislation.

    PubMed

    Braude, M

    1983-01-01

    This article examines the consequences of the 1973 US Supreme Court decision legalizing abortion as well as potential implications of proposed legilation aimed at nullifying this decision. In addition to giving women the right to determine their own reproduction, legal abortion had had beneficial health effects for both mothers and infants. The partial reversal of abortion gains due to restrictions on public funding and limitations on how and where abortions can be performed has produced a slight increase in abortion mortality, but the impact has not been dramatic. Moreover, each year since 1973, women have been obtaining abortions earlier in pregnancy. Abortion may be experienced as a loss by the mother, but there is no evidence of serious psychological sequelae. In contrast, a large body of evidence supports the physical, psychological, and social benefits of legal abortion to women, children, and families. However, proponents of the proposed Human Life Amendment place protection of the rights of the fetus over all other considerations. Their antiabortion actions have challenged the medical tradition of privacy and the confidentiality of the doctor-patient relationship. Most supporters of legal abortion would prefer that there be fewer abortions; such a decrease is more likely as a result of better education and contraceptive methods rather than coercion. PMID:12340335

  17. Abortion: taking the debate seriously.

    PubMed

    Kottow Lang, Miguel Hugo

    2015-01-01

    Voluntarily induced abortion has been under permanent dispute and legal regulations, because societies invariably condemn extramarital pregnancies. In recent decades, a measure of societal tolerance has led to decriminalize and legalize abortion in accordance with one of two models: a more restricted and conservative model known as therapeutic abortion, and the model that accepts voluntary abortion within the first trimester of pregnancy. Liberalization of abortion aims at ending clandestine abortions and decriminalizes the practice in order to increase reproductive education and accessibility of contraceptive methods, dissuade women from interrupting their pregnancy and, ultimately, make abortion a medically safe procedure within the boundaries of the law, inspired by efforts to reduce the incidence of this practice. The current legal initiative to decriminalize abortion in Chile proposes a notably rigid set of indications which would not resolve the three main objectives that need to be considered: 1) Establish the legal framework of abortion; 2) Contribute to reduce social unrest; 3) Solve the public health issue of clandestine, illegal abortions. Debate must urgently be opened to include alternatives in line with the general tendency to respect women's decision within the first trimester of pregnancy. PMID:26057783

  18. Unsafe abortion: the preventable pandemic.

    PubMed

    Grimes, David A; Benson, Janie; Singh, Susheela; Romero, Mariana; Ganatra, Bela; Okonofua, Friday E; Shah, Iqbal H

    2006-11-25

    Ending the silent pandemic of unsafe abortion is an urgent public-health and human-rights imperative. As with other more visible global-health issues, this scourge threatens women throughout the developing world. Every year, about 19-20 million abortions are done by individuals without the requisite skills, or in environments below minimum medical standards, or both. Nearly all unsafe abortions (97%) are in developing countries. An estimated 68 000 women die as a result, and millions more have complications, many permanent. Important causes of death include haemorrhage, infection, and poisoning. Legalisation of abortion on request is a necessary but insufficient step toward improving women's health; in some countries, such as India, where abortion has been legal for decades, access to competent care remains restricted because of other barriers. Access to safe abortion improves women's health, and vice versa, as documented in Romania during the regime of President Nicolae Ceausescu. The availability of modern contraception can reduce but never eliminate the need for abortion. Direct costs of treating abortion complications burden impoverished health care systems, and indirect costs also drain struggling economies. The development of manual vacuum aspiration to empty the uterus, and the use of misoprostol, an oxytocic agent, have improved the care of women. Access to safe, legal abortion is a fundamental right of women, irrespective of where they live. The underlying causes of morbidity and mortality from unsafe abortion today are not blood loss and infection but, rather, apathy and disdain toward women. PMID:17126724

  19. The Politicization of Abortion and the Evolution of Abortion Counseling

    PubMed Central

    2013-01-01

    The field of abortion counseling originated in the abortion rights movement of the 1970s. During its evolution to the present day, it has faced significant challenges, primarily arising from the increasing politicization and stigmatization of abortion since legalization. Abortion counseling has been affected not only by the imposition of antiabortion statutes, but also by the changing needs of patients who have come of age in a very different era than when this occupation was first developed. One major innovation—head and heart counseling—departs in significant ways from previous conventions of the field and illustrates the complex and changing political meanings of abortion and therefore the challenges to abortion providers in the years following Roe v Wade. PMID:23153144

  20. Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)

    PubMed Central

    Timerman, David; Greene, David F.; Urzay, Javier; Ackerman, Josef D.

    2014-01-01

    In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind–stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulence-driven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal- from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems. PMID:25297315

  1. Morphological characterization of pollens from three Apiaceae species and their ingestion by twelve-spotted lady beetle (Coleoptera: Coccinellidae).

    PubMed

    D'Ávila, V A; Aguiar-Menezes, E L; Gonçalves-Esteves, V; Mendonça, C B F; Pereira, R N; Santos, T M

    2016-04-19

    Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae), but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill.) was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems. PMID:27097091

  2. Bodies, rights and abortion.

    PubMed

    McLachlan, H V

    1997-06-01

    The issue of abortion is discussed with reference to the claim that people have a right of control over their own bodies. Do people "own" their own bodies? If so, what would be entailed? These questions are discussed in commonsense terms and also in relation to the jurisprudence of Hohfeld, Honore, Munzer and Waldron. It is argued that whether or not women are morally and/or should be legally entitled to have abortions, such entitlements cannot be derived from a general moral entitlement to do what we will with our own bodies since there is no such entitlement. Whether or not we "own" them, we can have rights duties, liabilities, restrictions and disadvantages as well as rights concerning our own bodies. PMID:9220332

  3. 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

  4. Cytochrome P450 family member CYP704B2 catalyzes the {omega}-hydroxylation of fatty acids and is required for anther cutin biosynthesis and pollen exine formation in rice.

    PubMed

    Li, Hui; Pinot, Franck; Sauveplane, Vincent; Werck-Reichhart, Danièle; Diehl, Patrik; Schreiber, Lukas; Franke, Rochus; Zhang, Ping; Chen, Liang; Gao, Yawei; Liang, Wanqi; Zhang, Dabing

    2010-01-01

    The anther cuticle and microspore exine act as protective barriers for the male gametophyte and pollen grain, but relatively little is known about the mechanisms underlying the biosynthesis of the monomers of which they are composed. We report here the isolation and characterization of a rice (Oryza sativa) male sterile mutant, cyp704B2, which exhibits a swollen sporophytic tapetal layer, aborted pollen grains without detectable exine, and undeveloped anther cuticle. In addition, chemical composition analysis indicated that cutin monomers were hardly detectable in the cyp704B2 anthers. These defects are caused by a mutation in a cytochrome P450 family gene, CYP704B2. The CYP704B2 transcript is specifically detected in the tapetum and the microspore from stage 8 of anther development to stage 10. Heterologous expression of CYP704B2 in yeast demonstrated that CYP704B2 catalyzes the production of omega -hydroxylated fatty acids with 16 and 18 carbon chains. Our results provide insights into the biosynthesis of the two biopolymers sporopollenin and cutin. Specifically, our study indicates that the omega -hydroxylation pathway of fatty acids relying on this ancient CYP704B family, conserved from moss to angiosperms, is essential for the formation of both cuticle and exine during plant male reproductive and spore development. PMID:20086189

  5. 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

  6. 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

  7. Patterns of pollen removal and deposition in Polemonium brandegeei (Polemoniaceae): the role of floral visitors, floral design and sexual interference.

    PubMed

    Kulbaba, M W; Worley, A C

    2014-11-01

    The arrangement, colour, shape and size of floral parts (collectively floral design) have evolved primarily to promote mating success via animal-mediated pollen transfer. Although numerous studies have examined variation in pollinator assemblages, relatively few have examined patterns of pollen removal and deposition in the presence of fluctuating pollinators and ineffective floral visitors; therefore, net pollen removal and deposition by entire visitor assemblages are unclear. We studied the timing (diurnal or nocturnal) and effects of floral traits on pollen removal and deposition under a dynamic visitor assemblage of Polemonium brandegeei. We quantified pollen grains remaining in anthers (pollen removal) and deposited on stigmas (pollen deposition) of plants visited during either the day (07:30-20:00 h) or night (20:30-07:30 h) in natural populations over two flowering seasons. Pollen removal and deposition occurred both diurnally and nocturnally during our study. Increased diurnal removal and deposition coincided with peak floral visitations in 2006. This increase in pollen removal and deposition may reflect increased visits by pollen consumers, effective hawkmoth pollinators and increased self-pollen deposition due to hot, dry weather. Nonlinear effects of style length significantly affected pollen removal, with less pollen remaining in flowers with intermediate style lengths. Pollen deposition was more complex, with herkogamy and anther height affecting deposition. Further, close proximity of stigmas and anthers increased the potential for sexual interference between pollen removal and deposition. Overall, flower visitations and pollen removal and deposition varied between years and populations, but sex organ placement consistently influenced the removal and deposition of pollen. PMID:24850527

  8. Penetration of the Stigma and Style Elicits a Novel Transcriptome in Pollen Tubes, Pointing to Genes Critical for Growth in a Pistil

    PubMed Central

    Qin, Yuan; Leydon, Alexander R.; Manziello, Ann; Pandey, Ritu; Mount, David; Denic, Stojan; Vasic, Bane; Johnson, Mark A.; Palanivelu, Ravishankar

    2009-01-01

    Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. Using microarray analysis in Arabidopsis, we show that pollen tubes that have grown through stigma and style tissues of a pistil have a distinct gene expression profile and express a substantially larger fraction of the Arabidopsis genome than pollen grains or pollen tubes grown in vitro. Genes involved in signal transduction, transcription, and pollen tube growth are overrepresented in the subset of the Arabidopsis genome that is enriched in pistil-interacted pollen tubes, suggesting the possibility of a regulatory network that orchestrates gene expression as pollen tubes migrate through the pistil. Reverse genetic analysis of genes induced during pollen tube growth identified seven that had not previously been implicated in pollen tube growth. Two genes are required for pollen tube navigation through the pistil, and five genes are required for optimal pollen tube elongation in vitro. Our studies form the foundation for functional genomic analysis of the interactions between the pollen tube and the pistil, which is an excellent system for elucidation of novel modes of cell–cell interaction. PMID:19714218

  9. Austerity and Abortion in the European Union.

    PubMed

    Lima, Joana Madureira; Reeves, Aaron; Billari, Francesco; McKee, Martin; Stuckler, David

    2016-06-01

    Economic hardship accompanying large recessions can lead families to terminate unplanned pregnancies. To assess whether abortions have risen during the recession, we collected crude abortion data from 2000 to 2012 from Eurostat for countries that had legal abortions and complete data. Declining trends in abortion ratios between 2000 and 2009 have been reversing. Excess abortions between 2010 and 2012 totaled 10.6 abortions per 1000 pregnancies ending in abortion or birth or 6701 additional abortions (95% CI 1190-9240) with stronger effects in younger ages. Economic shocks may increase recourse to abortion. Further research should explore causal pathways and protective factors. PMID:27009038

  10. Austerity and Abortion in the European Union

    PubMed Central

    Reeves, Aaron; Billari, Francesco; McKee, Martin; Stuckler, David

    2016-01-01

    Economic hardship accompanying large recessions can lead families to terminate unplanned pregnancies. To assess whether abortions have risen during the recession, we collected crude abortion data from 2000 to 2012 from Eurostat for countries that had legal abortions and complete data. Declining trends in abortion ratios between 2000 and 2009 have been reversing. Excess abortions between 2010 and 2012 totaled 10.6 abortions per 1000 pregnancies ending in abortion or birth or 6701 additional abortions (95% CI 1190–9240) with stronger effects in younger ages. Economic shocks may increase recourse to abortion. Further research should explore causal pathways and protective factors. PMID:27009038

  11. Immunologically mediated abortion (IMA).

    PubMed

    Giacomucci, E; Bulletti, C; Polli, V; Prefetto, R A; Flamigni, C

    1994-06-01

    Roughly 20% of all clinical pregnancies evolve into "spontaneous abortions". The causes of spontaneous abortion have been determined in under 60% of the total and comprise genetic, infectious, hormonal and immunological factors. In some cases the immune tolerance mechanism may be impaired and the foetus immunologically rejected (IMA, immunologically mediated abortion). The immunological mechanism implicated depends on the time in which pregnancy loss takes place. During preimplantation and up to the end of implantation (13th day) the cell-mediated immune mechanism (potential alloimmune etiologies) is responsible for early abortion. This mechanism involves immunocompetent decidual cells (eGL, endometrial granulated lymphocytes) already present during pre-decidualization (late luteal phase) and their production of soluble factors or cytokines. Once the implantation process is over, after blastocyst penetration of the stroma and the decidual reaction of uterine tissue, IMA could be caused by cell-mediated and humoral mechanism (anti-paternal cytotoxic antibodies or autoantibody etiology), by the production of paternal anti major histocompatibility complex antibodies, or even by an autoimmune disorder leading to the production of autoantibodies (antiphospholipid antibodies, antinuclear antibodies or polyclonal B cell activation). The diagnostic work-up adopted to select IMA patients is crucial and includes primary (karyotype of both partners, toxo-test, hysterosalpingography, endometrial biopsy, thyroid function tests, serum hprolactin, luteal phase dating) and secondary (full hemochromocytometric test, search for LE cells, lupus anticoagulant, anticardiolipin, antinuclear antibodies, Rheumatoid factor, blood complement VDRL) investigations. Therapeutical approaches vary. If autoimmune disorders are demonstrated therapies with different combinations of corticosteroids, aspirin and heparin or intravenous immunoglobulin are administered. Otherwise, therapy with paternal

  12. 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.

  13. 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

  14. Histological analysis of pollen-pistil interactions in sour passion fruit plants (Passiflora edulis Sims).

    PubMed

    Madureira, Hérika Chagas; Pereira, Telma Nair Santana; Da Cunha, Maura; Klein, Denise Espellet

    2012-08-01

    The success of sexual plant reproduction is directly influenced by specific interactions between the pollen and pistil. Light, fluorescence and scanning electron microscopy techniques were used to evaluate the steps of pollination in sour passion fruit plants (Passiflora edulis Sims). In the compatible interaction, pollen tubes grow through stigma projections towards the ovary. The pollen grain surface was found to be spheroidal and to consist of heteroreticulate exine with six colpi. Furthermore, analysis in vivo of pollen-pistil interactions indicated that stigmas of flowers 24 hours before anthesis are unable to discriminate compatible (genetically unrelated) and incompatible (genetically related) pollen grains. Taken together, these results provide insight into the cellular mechanisms underlying pollination in passion fruit plants. PMID:23185783

  15. 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.

  16. The abortion debate in Australia.

    PubMed

    Read, Christine Margaret

    2006-09-01

    I recently watched a fascinating documentary about the crusade of Dr Bertram Wainer in the 1960s to bring the practice of illegal abortion in Victoria to an end. It documented the profound horror of the backyard abortion that so often ended in infection, sterility or death, and served as a potent reminder of a practice to which we must never return. Of course that cant happen again, abortion is legal now, isnt it? In Victoria in 1969 a Supreme Court judge ruled that an abortion is not unlawful if a doctor believed that: the abortion is necessary to preserve the woman from serious danger to her life or physical or mental health (Menhennit ruling). In Australia today however, abortion law remains conditional, unclear and inconsistent and, except in the ACT, is still part of criminal statutes. PMID:16969440

  17. Legal abortion and public health.

    PubMed

    Tietze, C

    1984-01-01

    Over 15 million abortions have been performed in the US since the process of abortion legalization began in 1967. Consequences of legalization have included a marked reduction of pregnancy-related mortality and the prevention in many cases of the birth of infants with major physical or mental defects. Prenatal diagnosis, backed up by selective abortion, has made procreation a possibility for many couples who might otherwise avoid childbearing. However, the number of abortions performed on the basis of prenatal diagnosis remains small, comprising only about .01% of all legal abortions. In recent months, the pro-choice movement in the US has been handed 2 important victories: the US Supreme Court reaffirmed the 1973 decision legalizing abortion and the US Senate defeated a constitutional amendment intended to reverse this decision. As a result of these victories, contributions to pro-choice groups have declined. Continued vigilance is needed to protect these victories. PMID:12267089

  18. Abortion law reform in Nepal.

    PubMed

    Upreti, Melissa

    2014-08-01

    Across four decades of political and social action, Nepal changed from a country strongly enforcing oppressive abortion restrictions, causing many poor women's long imprisonment and high rates of abortion-related maternal mortality, into a modern democracy with a liberal abortion law. The medical and public health communities supported women's rights activists in invoking legal principles of equality and non-discrimination as a basis for change. Legislative reform of the criminal ban in 2002 and the adoption of an Interim Constitution recognizing women's reproductive rights as fundamental rights in 2007 inspired the Supreme Court in 2009 to rule that denial of women's access to abortion services because of poverty violated their constitutional rights. The government must now provide services under criteria for access without charge, and services must be decentralized to promote equitable access. A strong legal foundation now exists for progress in social justice to broaden abortion access and reduce abortion stigma. PMID:24890742

  19. 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

  20. 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

  1. Impacts of air pollution exposure on the allergenic properties of Arizona cypress pollens

    NASA Astrophysics Data System (ADS)

    Shahali, Y.; Pourpak, Z.; Moin, M.; Zare, A.; Majd, A.

    2009-02-01

    Epidemiological studies have demonstrated that urbanization and high levels of vehicle emissions correlated with the increasing trend of pollen-induced respiratory allergies. Numerous works have investigated the role of pollutants in the pathogenesis of respiratory diseases but impacts of anthropogenic pollution on pollen allergenic properties are still poorly understood. The objective of this survey was to evaluate impacts of the traffic-related pollution on the structure and allergenic protein content of Arizona cypress (Cupressus arizonica, CA) pollens, recognized as a rising cause of seasonal allergy in various regions worldwide. According to our results, traffic-related air pollution by its direct effects on the elemental composition of pollens considerably increased the fragility of the pollen exine, causing numerous cracks in its surface and facilitating pollen content liberation. Pollen grains were also covered by numerous submicronic orbicules which may act as effective vectors for pollen-released components into the lower regions of respiratory organs. On the other hand, this study provides us reliable explications about the low efficiency of standard commercial allergens in the diagnosis of the Arizona cypress pollen allergy in Tehran. Although traffic related pollution affects the allergenic components of CA pollens, the repercussions on the respiratory health of urban populations have yet to be clarified and need further investigations.

  2. Are the birch trees in Southern England a source of Betula pollen for North London?

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Smith, M.; Brandt, J.; Emberlin, J.

    2009-01-01

    Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts ( n = 60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200-0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

  3. Influence of boundary-layer dynamics on pollen dispersion and viability

    NASA Astrophysics Data System (ADS)

    Arritt, Raymond W.; Viner, Brian J.; Westgate, Mark E.

    2013-04-01

    Adoption of genetically modified (GM) crops has raised concerns that GM traits can accidentally cross into conventional crops or wild relatives through the transport of wind-borne pollen. In order to evaluate this risk it is necessary to account both for dispersion of the pollen grains and environmental influences on pollen viability. The Lagrangian approach is suited to this problem because it allows tracking the environmental temperature and moisture that pollen grains experience as they travel. Taking advantage of this capability we have combined a high-resolution version of the WRF meteorological model with a Lagrangian particle dispersion model to predict maize pollen dispersion and viability. WRF is used to obtain fields of wind, turbulence kinetic energy, temperature, and humidity which are then used as input to the Lagrangian dispersion model. The dispersion model in turn predicts transport of a statistical sample of a pollen cloud from source plants to receptors. We also use the three-dimensional temperature and moisture fields from WRF to diagnose changes in moisture content of the pollen grains and consequent loss of viability. Results show that turbulent motions in the convective boundary layer counteract the large terminal velocity of maize pollen grains and lift them to heights of several hundred meters, so that they can be transported long distances before settling to the ground. We also found that pollen lifted into the upper part of the boundary layer remains more viable than has been inferred using surface observations of temperature and humidity. This is attributed to the thermal and moisture structure that typifies the daytime atmospheric boundary layer, producing an environment of low vapor pressure deficit in the upper boundary layer which helps maintain pollen viability.

  4. 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

  5. Dworkin and Casey on abortion.

    PubMed

    Stroud, Sarah

    1996-01-01

    This article responds to two important recent treatments of abortion rights. I will mainly discuss Ronald Dworkin's recent writings concerning abortion: his article "Unenumerated rights: whether and how Roe should be overruled," and his book Life's Dominion. In these writings Dworkin presents a novel view of what the constitutional and moral argument surronding abortion is really about. Both debates actually turn, he argues, on the question of how to interpret the widely shared idea that human life is sacred. At the heart of the abortion debate is the essentially religious notion that human life has value which transcends its value to any particular person; abortion is therefore at bottom a religious issue. Dworkin hopes to use this analysis to show that the religion clauses of the First Amendment provide a "textual home" for a woman's right to choose abortion. I wish to scrutinize this suggestion here; I want to probe the precise consequences for abortion rights of such an understanding of their basis. I will argue that the consequences are more radical than Dworkin seems to realize. The other work I will examine here is the important 1992 Supreme Court decision on abortion, Planned Parenthood v. Casey. The controlling opinion in that case, written jointly by Justices Kennedy, O'Connor, and Souter, strongly reaffirmed Roe v. Wade, but also upheld most of the provisions of a Pennsylvania statute that had mandated various restrictions on abortion. The justices' basis for upholding these restictions was their introduction of a new constitutional standard for abortion regulations, an apparently weaker standard than those that had governed previous Supreme Court abortion decisions. I think there is a flaw in Casey's new constitutional test for abortion regulations, and I will explain, when we turn to Casey, what it is and why it bears a close relation to Dworkin's reluctance to carry his argument as far as it seems to go. PMID:11660187

  6. Simplified classification of spontaneous abortions.

    PubMed Central

    Rushton, D I

    1978-01-01

    A simple classification of products of conception aborted in early pregnancy is described. This classification bears a closer relation to the aetiology of the abortions and the timing of the teratological insult in those conceptuses with morphological abnormalities than have previous classifications. It is hoped it may be of value in counselling patients who abort recurrently and also in the assessment of some environmental hazards purported to cause early pregnancy wastage and congenital malformations. Images PMID:564967

  7. Structural correlates of imbibitional injury in Typha pollen

    NASA Technical Reports Server (NTRS)

    Sack, F. D.; Leopold, A. C.; Hoekstra, F. A.

    1988-01-01

    The ultrastructure of Typha latifolia pollen was examined as a function of pollen moisture content and incubation temperature, in order to identify possible lesions induced by imbibitional chilling. A syndrome of structural traits was found which characterizes damaged grains. Compared to viable grains, the protoplast of damaged pollen has a higher proportion of its volume occupied by vesicles, and less volume occupied by cytoplasm. Damaged grains also tend to have dilated cisternae of endoplasmic reticulum, larger starch grains and lipid bodies, poorly preserved mitochondria and membranes, and, sometimes, numerous electron-dense globules associated with membranes. The percentage of grains exhibiting this damage syndrome correlates closely with the number of ungerminated grains in most samples, regardless of moisture content or incubation temperature. Injury due to rapid imbibition from the dry state or to imbibitional chilling appear to be similar structurally, regardless of whether the stresses are imposed singly or together. The injury is not confined to one cell component (e.g., mitochondria), but may involve a generalized disruption of membranes. These results suggest that similar stress responses are elicited by imbibition from the dry state and by imbibitional chilling.

  8. Anti-abortion movement.

    PubMed

    Wilson, K

    1985-01-01

    At the same time that American women celebrate the freedoms won thus far for so many Americans, American women must realize they face some of the greatest threats to liberty in recent memory. To understand this movement against American women, it is necessary to first understand the roots of the historic movement for women's rights. Reproductive freedom for many years topped the agenda of the modern women's movement. At a time and in a land where rights were being enriched and liberty prized, choice took a prominent role, specifically, the right to abortion but also generally to repdocuctive freedom and the many underlying issues involved. This is why the various efforts to criminalize abortion effect every citizen, because they pose a serious threat to the constitutional rights of each individual. This is the intellectual view, or the "head" argument. The Constitution states that: "Congress shall make no laws respecting an establishment of religion, or prohibiting the free exercise thereof; the enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people; and no state shall make or enforce any laws which shall abridge the privileges or immunities of citizens of the US." Each of these clauses expresses the philosophy on which the Constitution was founded -- individual liberty. While there has been some legitimate disagreement over what constitutes an inalienable right, the concept is clear: the government should not become involved in personal philosophical or religious matters, except to permit the freedom of personal philosophical or religious expression. The anti-abortion contignent makes its case by claiming that a fertilized egg is a cona fide person and should, therefore, be guaranteed the Constitution's full roster of protections. In its landmark Roe v. Wade opinion, the Supreme Court held what pro-choice activities have been claiming for years. Since there is no empirical test by which measure

  9. 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.

  10. Second trimester abortions in India.

    PubMed

    Dalvie, Suchitra S

    2008-05-01

    This article gives an overview of what is known about second trimester abortions in India, including the reasons why women seek abortions in the second trimester, the influence of abortion law and policy, surgical and medical methods used, both safe and unsafe, availability of services, requirements for second trimester service delivery, and barriers women experience in accessing second trimester services. Based on personal experiences and personal communications from other doctors since 1993, when I began working as an abortion provider, the practical realities of second trimester abortion and case histories of women seeking second trimester abortion are also described. Recommendations include expanding the cadre of service providers to non-allopathic clinicians and trained nurses, introducing second trimester medical abortion into the public health system, replacing ethacridine lactate with mifepristone-misoprostol, values clarification among providers to challenge stigma and poor treatment of women seeking second trimester abortion, and raising awareness that abortion is legal in the second trimester and is mostly not requested for reasons of sex selection. PMID:18772082

  11. [Psychological consequences of induced abortion].

    PubMed

    Schleiss, L; Mygind, K A; Borre, R V; Petersson, B H

    1997-06-01

    One hundred and thirty consecutive women were interviewed about the development of psychological symptoms related to induced abortion two days before and four months after the abortion. Sixty-one (47%) participated in the second interview. Of the 61 women, 52% were psychologically influenced before the abortion to an extent which indicated severe crisis or actual psychiatric illness. Four months after the abortion 13 of these women were still psychologically affected. Furthermore, five women who were not affected before the abortion had developed psychological problems. Among ten of these women (16%) the physiological problems could only be related to the circumstance in connection with the abortion. For a number of women (30%) the abortion had a negative influence on their relationships and their sex lives, whereas other claimed that their relationship had become closer because of their reactions towards the abortions. In spite of these conditions all women indicated that their decision about the abortion had been the correct one under the given circumstances. PMID:9206861

  12. Taphonomic bias in pollen and spore record: a review

    SciTech Connect

    Fisk, L.H.

    1986-05-01

    The high dispersibility and ease of pollen and spore transport have led researchers to conclude erroneously that fossil pollen and spore floras are relatively complete and record unbiased representations of the regional vegetation extant at the time of sediment deposition. That such conclusions are unjustified is obvious when the authors remember that polynomorphs are merely organic sedimentary particles and undergo hydraulic sorting not unlike clastic sedimentary particles. Prior to deposition in the fossil record, pollen and spores can be hydraulically sorted by size, shape, and weight, subtly biasing relative frequencies in fossil assemblages. Sorting during transport results in palynofloras whose composition is environmentally dependent. Therefore, depositional environment is an important consideration to make correct inferences on the source vegetation. Sediment particle size of original rock samples may contain important information on the probability of a taphonomically biased pollen and spore assemblage. In addition, a reasonable test of hydraulic sorting is the distribution of pollen grain sizes and shapes in each assemblage. Any assemblage containing a wide spectrum of grain sizes and shapes has obviously not undergone significant sorting. If unrecognized, taphonomic bias can lead to paleoecologic, paleoclimatic, and even biostratigraphic misinterpretations.

  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. 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

  15. 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

  16. 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

  17. Legal abortion: a painful necessity.

    PubMed

    Kero, A; Högberg, U; Jacobsson, L; Lalos, A

    2001-12-01

    This study was conducted to increase knowledge about the psychosocial background and current living conditions of Swedish women seeking abortion, along with their motives for abortion and their feelings towards pregnancy and abortion. Two hundred and eleven women answered a questionnaire when they consulted the gynaecologist for the first time. The study indicates that legal abortion may be sought by women in many circumstances and is not confined to those in special risk groups. For example, most women in the sample were living in stable relationships with adequate finances. The motives behind a decision to postpone or limit the number of children revealed a wish to have children with the right partner and at the right time in order to combine good parenting with professional career. The study shows that prevailing expectations about lifestyle render abortion a necessity in family planning. One-third of the women had had a previous abortion(s) and 12% had become pregnant in a situation where they had felt pressured or threatened by the man. Two-thirds of the women characterised their initial feelings towards the pregnancy solely in painful words while nearly all the others reported contradictory feelings. Concerning feelings towards the coming abortion, more than half expressed both positive and painful feelings such as anxiety, relief, grief, guilt, anguish, emptiness and responsibility, while one-third expressed only painful feelings. However, almost 70% stated that nothing could change their decision to have an abortion. Thus, this study highlights that contradictory feelings in relation to both pregnancy and the coming abortion are common but are very seldom associated with doubts about the decision to have an abortion. PMID:11710423

  18. Among-species differences in pollen quality and quantity limitation: implications for endemics in biodiverse hotspots

    PubMed Central

    Alonso, Conchita; Navarro-Fernández, Carmen M.; Arceo-Gómez, Gerardo; Meindl, George A.; Parra-Tabla, Víctor; Ashman, Tia-Lynn

    2013-01-01

    Background and Aims Insufficient pollination is a function of quantity and quality of pollen receipt, and the relative contribution of each to pollen limitation may vary with intrinsic plant traits and extrinsic ecological properties. Community-level studies are essential to evaluate variation across species in quality limitation under common ecological conditions. This study examined whether endemic species are more limited by pollen quantity or quality than non-endemic co-flowering species in three endemic-rich plant communities located in biodiversity hotspots of different continents (Andalusia, California and Yucatan). Methods Natural variations in pollen receipt and pollen tube formation were analysed for 20 insect-pollinated plants. Endemic and non-endemic species that co-flowered were paired in order to estimate and compare the quantity and quality components of pre-zygotic pollination success, obtained through piecewise regression analysis of the relationship between pollen grains and pollen tubes of naturally pollinated wilted flowers. Key Results Pollen tubes did not frequently exceed the number of ovules per flower. Only the combination of abundant and good quality pollen and a low number of ovules per flower conferred relief from pre-zygotic pollen limitation in the three stochastic pollination environments studied. Quality of pollen receipt was found to be as variable as quantity among study species. The relative pollination success of endemic and non-endemic species, and its quantity and quality components, was community dependent. Conclusions Assessing both quality and quantity of pollen receipt is key to determining the ovule fertilization potential of both endemic and widespread plants in biodiverse hotspot regions. Large natural variation among flowers of the same species in the two components and pollen tube formation deserves further analysis in order to estimate the environmental, phenotypic and intraindividual sources of variation that may

  19. Adolescent pregnancy: a study of aborters and non-aborters.

    PubMed

    Kane, F J; Lachenbruch, P A

    1973-10-01

    In a June 1970 through January 1971 study of 99 single girls seeking abortion and 33 single girls choosing to complete the pregnancy, knowledge of and/or access to contraceptives were not the problem. Emotional factors such as guilt over sexual activity, acting-out disorders (rebellious attitude, hippie lifestyle, indifference toward others), or severe reactions to loss of a love relationship contributed to pregnancy in both groups. The girls who became pregnant, especially the ones who chose to complete the pregnancy, viewed pregnancy and motherhood as a source of gratification and self-esteem. Research on motivational factors in adolescent pregnancy is needed to prevent high recidivism. The majority of state abortion laws requiring phychiatric deficiencies for abortions are misguided, since the girls who chose not to abort were more psychiatrically disturbed than the ones who had abortions. PMID:4742821

  20. Effects of shading on spike differentiation and grain yield formation of summer maize in the field

    NASA Astrophysics Data System (ADS)

    Cui, Haiyan; Camberato, James J.; Jin, Libin; Zhang, Jiwang

    2015-09-01

    A field experiment was conducted to study the effects of shading on tassel and ear development and yield formation of three summer maize hybrids Zhenjie 2 (ZJ2), Denghai 605 (DH605), and Zhengdan 958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth stages from silking stage (R1) to physiological maturity stage (R6) (treatment S1), from the sixth extended leaf stage (V6) to R1 (treatment S2) and from seeding to R6 (treatment S3). Shading had no significant effect on the time from seeding to shoot emergence (VE); however, subsequent growth and development were delayed with shading beyond this point. The differentiation time of both tassel and ear delayed, and female spike (tassel) floret differentiation, sexual organ formation time, and anthesis-silking interval (ASI) were lengthened. After shading, the total number of floret, silk, and fertilization floret reduced significantly; the number of abortive seeds increased, and the total setting percentage among different treatments showed that CK>S2>S1>S3; and the total setting percentages in S1, S2, and S3 of ZD958 were 44, 72, and 15 % respectively. The total floret number of tassel primordium differentiation, fertility rate, and seed setting rate of florets in S3 treatment was the minimum; kernels per ear decreased seriously and single ear setting percentage was only 16 %; although floret degeneration number of S2 during ear differentiation stages increased and floret fertility rate reduced than that of CK, fertilization flower seed production increased and abortive seed decreased after canceling shading. Aborted kernel of S1 increased and kernel dry weight reduced, resulting in a significant decrease of kernel number per ear and kernel weight, and the grain abortive rate of 40-62 %. In conclusion, shading changed the growth and development process and caused infertility of tassel and ear; tassel branches decreased

  1. Abortion and parental responsibility.

    PubMed

    Winston, M E

    1986-01-01

    A theory on the morality of abortion is derived from the presumption that parents have special moral obligations to nurture their immature children. Three alternative models of the acquisition of parental responsibilities are examined: one based on biological relationships, one based on consent, and one based on causal responsibility. Each of the models is examined in terms of its ability to handle cases involving nonstandard methods of procreation, such as surrogate motherhood, artificial insemination by donor, and embryo transfer. It is concluded that the model based on causal responsibility provides the most adequate criterion for the ascription of parental responsibility toward fetuses. PMID:11650732

  2. Denial of abortion in legal settings

    PubMed Central

    Gerdts, Caitlin; DePiñeres, Teresa; Hajri, Selma; Harries, Jane; Hossain, Altaf; Puri, Mahesh; Vohra, Divya; Foster, Diana Greene

    2015-01-01

    Background Factors such as poverty, stigma, lack of knowledge about the legal status of abortion, and geographical distance from a provider may prevent women from accessing safe abortion services, even where abortion is legal. Data on the consequences of abortion denial outside of the US, however, are scarce. Methods In this article we present data from studies among women seeking legal abortion services in four countries (Colombia, Nepal, South Africa and Tunisia) to assess sociodemographic characteristics of legal abortion seekers, as well as the frequency and reasons that women are denied abortion care. Results The proportion of women denied abortion services and the reasons for which they were denied varied widely by country. In Colombia, 2% of women surveyed did not receive the abortions they were seeking; in South Africa, 45% of women did not receive abortions on the day they were seeking abortion services. In both Tunisia and Nepal, 26% of women were denied their wanted abortions. Conclusions The denial of legal abortion services may have serious consequences for women's health and wellbeing. Additional evidence on the risk factors for presenting later in pregnancy, predictors of seeking unsafe illegal abortion, and the health consequences of illegal abortion and childbirth after an unwanted pregnancy is needed. Such data would assist the development of programmes and policies aimed at increasing access to and utilisation of safe abortion services where abortion is legal, and harm reduction models for women who are unable to access legal abortion services. PMID:25511805

  3. 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

  4. Influence of wind velocity on pollen concentration in urban canopy layer

    NASA Astrophysics Data System (ADS)

    Pospisil, J.; Jícha, M.

    2009-09-01

    POLLEN RELEASE Temperature is the basic parameter for prediction of the beginning of the pollen season and identification days with good potential for pollen release. Different approaches are used for determination of the start of the pollen season: i) the sum of daily pollen counts = x criterion (Arnold 2002), ii) the mean temperature method during pre-defined period (Sparks, 2000), iii) the temperature sum method (Jones 1992). Another parameters influencing pollen release are: day light length, morning temperature gradient, relative humidity. The mentioned parameters enable to create the "statistical” model for determination of timing of pollen potential release. But, the correct determination of pollen release timing is only the first step to correct prediction of pollen concentration in air. The above mentioned collection of parameters isn't complete for correct pollen production prediction without inclusion of the actual wind velocity. The wind velocity directly influences the pollen release rate from mother plant and subsequently transport of pollen grains. From this reason, influence of wind conditions has to be considered as exactly as possible in complex prediction models. WIND VELOCITY AND POLLEN CONCENTRATION Results of in-situ measurements were used for carried out analysis of the relation between wind velocity and pollen concentration in an urban canopy layer. The mean daily wind velocities and the mean daily pollen concentrations were used as the input data describing the pollen season 2005 in an inner part of the city of Brno (pop. 400 000). The mean daily pollen concentrations were matched to corresponding mean daily wind velocity and depicted in graphs. This procedure was done for all locally monitored aeroallergens, namely Alnus, Ambrosia, Betula, Artemis, Corylus, Fraxinus, Poaceae and Quercus. Only days with significant pollen concentration (above 10% of maximal pollen season concentration) were considered for detail analysis. Clear

  5. Partner violence and abortion characteristics.

    PubMed

    Colarossi, Lisa; Dean, Gillian

    2014-01-01

    We conducted a retrospective cohort study using randomly selected medical charts of women reporting a history of partner violence and women with no history of partner violence at the time of a family planning or abortion appointment (n = 6,564 per group). We analyzed lifetime history of partner violence for odds of lifetime history of abortion and miscarriage number, and birth control problems. To more closely match timing, we analyzed a subsample of 2,186 women reporting current violence versus not at the time of an abortion appointment for differences in gestational age, medical versus surgical method choice, and return for follow-up visit. After adjusting for years at risk and demographic characteristics, women with a past history of partner violence were not more likely to have ever had one abortion, but they were more likely to have had problems with birth control, repeat abortions, and miscarriages than women with no history of violence. Women with current partner violence were also more likely to be receiving an abortion at a later gestational age. We found no differences between the groups in return for abortion follow-up visit or choice of surgical versus medication abortion. Findings support screening for the influence of partner violence on reproductive health and related safety planning. PMID:24580133

  6. Second-Trimester Abortion Overview

    MedlinePlus

    ... carrying a pregnancy to term – the risk for women having an abortion increases with gestation. xiv Qualitative evidence suggests the abortion referral process – connecting a pregnant woman with the right provider – is patchy. xv In short, a woman ...

  7. Sex Guilt in Abortion Patients

    ERIC Educational Resources Information Center

    Gerrard, Meg

    1977-01-01

    A measure of sex guilt was administered to clients of a university problem pregnancy counseling service who were planning to have abortions and to a group of sexually active nonpregnant university coeds. Sex guilt was found to be significantly higher for the abortion patients than for the nonpregnant group. (Author)

  8. Gene family analysis of the Arabidopsis pollen transcriptome reveals biological implications for cell growth, division control, and gene expression regulation.

    PubMed

    Pina, Cristina; Pinto, Francisco; Feijó, José A; Becker, Jörg D

    2005-06-01

    Upon germination, pollen forms a tube that elongates dramatically through female tissues to reach and fertilize ovules. While essential for the life cycle of higher plants, the genetic basis underlying most of the process is not well understood. We previously used a combination of flow cytometry sorting of viable hydrated pollen grains and GeneChip array analysis of one-third of the Arabidopsis (Arabidopsis thaliana) genome to define a first overview of the pollen transcriptome. We now extend that study to approximately 80% of the genome of Arabidopsis by using Affymetrix Arabidopsis ATH1 arrays and perform comparative analysis of gene family and gene ontology representation in the transcriptome of pollen and vegetative tissues. Pollen grains have a smaller and overall unique transcriptome (6,587 genes expressed) with greater proportions of selectively expressed (11%) and enriched (26%) genes than any vegetative tissue. Relative gene ontology category representations in pollen and vegetative tissues reveal a functional skew of the pollen transcriptome toward signaling, vesicle transport, and the cytoskeleton, suggestive of a commitment to germination and tube growth. Cell cycle analysis reveals an accumulation of G2/M-associated factors that may play a role in the first mitotic division of the zygote. Despite the relative underrepresentation of transcription-associated transcripts, nonclassical MADS box genes emerge as a class with putative unique roles in pollen. The singularity of gene expression control in mature pollen grains is further highlighted by the apparent absence of small RNA pathway components. PMID:15908605

  9. Herbivory in spiders: the importance of pollen for orb-weavers.

    PubMed

    Eggs, Benjamin; Sanders, Dirk

    2013-01-01

    Orb-weaving spiders (Araneidae) are commonly regarded as generalist insect predators but resources provided by plants such as pollen may be an important dietary supplementation. Their webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores. When recycling their orb webs, the spiders may therefore also feed on adhering pollen grains or fungal spores via extraoral digestion. In this study we measured stable isotope ratios in the bodies of two araneid species (Aculepeira ceropegia and Araneus diadematus), their potential prey and pollen to determine the relative contribution of pollen to their diet. We found that about 25% of juvenile orb-weaving spiders' diet consisted of pollen, the other 75% of flying insects, mainly small dipterans and hymenopterans. The pollen grains in our study were too large to be taken up accidentally by the spiders and had first to be digested extraorally by enzymes in an active act of consumption. Therefore, pollen can be seen as a substantial component of the spiders' diet. This finding suggests that these spiders need to be classified as omnivores rather than pure carnivores. PMID:24312430

  10. Herbivory in Spiders: The Importance of Pollen for Orb-Weavers

    PubMed Central

    Eggs, Benjamin; Sanders, Dirk

    2013-01-01

    Orb-weaving spiders (Araneidae) are commonly regarded as generalist insect predators but resources provided by plants such as pollen may be an important dietary supplementation. Their webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores. When recycling their orb webs, the spiders may therefore also feed on adhering pollen grains or fungal spores via extraoral digestion. In this study we measured stable isotope ratios in the bodies of two araneid species (Aculepeira ceropegia and Araneus diadematus), their potential prey and pollen to determine the relative contribution of pollen to their diet. We found that about 25% of juvenile orb-weaving spiders’ diet consisted of pollen, the other 75% of flying insects, mainly small dipterans and hymenopterans. The pollen grains in our study were too large to be taken up accidentally by the spiders and had first to be digested extraorally by enzymes in an active act of consumption. Therefore, pollen can be seen as a substantial component of the spiders’ diet. This finding suggests that these spiders need to be classified as omnivores rather than pure carnivores. PMID:24312430

  11. Gene-expression profile of developing pollen tube of Pyrus bretschneideri.

    PubMed

    Zhou, Hongsheng; Yin, Hao; Chen, Jianqing; Liu, Xing; Gao, Yongbin; Wu, Juyou; Zhang, Shaoling

    2016-01-01

    Pollen is an ideal model system for investigation of cell growth. In order to better understand the molecular biology mechanisms of the process of pear pollen tube development, RNA sequencing (RNA-Seq) technology was used to characterize the expression of genes during four development stages of pear pollen, including mature pollen grains (MP), hydrated pollen grains (HP), growing pollen tubes (PT) and stopped-growth pollen tubes (SPT). The four libraries generated a total of 47,072,151 clean reads that were mapped and assembled into 21,394 genes. Transcripts from the four stages were classified into 38 functional subcategories. Between MP and HP, 305 genes were differentially expressed, and 502 genes were differentially expressed between HP and PT. More importantly, we have observed that 2208 genes were differentially expressed between PT and SPT, and this is the first report of the gene expression comparison between the two development stages. Eight of the differentially expressed genes were randomly selected to confirm the RNA-Seq results by quantitative real-time PCR (qRT-PCR). Taken together, this research provides a platform for future research on pear pollen tube growth and growth cessation. PMID:26547040

  12. Bee pollen, a substrate that stimulates ochratoxin A production by Aspergillus ochraceus Wilh.

    PubMed

    Medina, Angel; González, Gabriela; Sáez, Joan M; Mateo, Rufino; Jiménez, Misericordia

    2004-03-01

    The capacity of bee pollen as a substrate for production of ochratoxin A (OTA) by a strain of Aspergillus ochraceus was studied. For control purposes corn, wheat and rice grains, and eleven liquid media were assayed. They were Yeast Extract Sucrose broth (YES), YES supplemented with 0.05, 0.1, 0.5, 1 and 5% bee pollen, YES supplemented with 0.5% peptone, 50% must, Wickerham medium, Aflatoxin Production medium and Coconut Broth Medium. Cultures were maintained at 28 degrees C for 4 weeks and were analyzed every seven days for OTA by liquid chromatography with fluorescence detection. OTA production in bee pollen was significantly (P < 0.01) higher than production in corn, wheat and rice grains regardless of incubation time. With regard to liquid cultures, OTA accumulation in YES supplemented with 5% bee pollen was significantly higher than in pollen-free liquid cultures. A positive correlation between the proportion of pollen added to YES medium and OTA level was observed. This is the first report concerning the use of bee pollen as a substrate to stimulate OTA production. On the basis of the preliminary results obtained in this study it can be hypothesized that bee pollen may constitute an important risk factor concerning the presence of OTA in the diet of consumers of that nutritious food. PMID:15046315

  13. Abortion: epidemiology, safety, and technique.

    PubMed

    Blumenthal, P D

    1992-08-01

    In 1991, the abortion literature was characterized by articles relating to 1) epidemiologic issues in abortion care, 2) advances in knowledge and experience with medical abortifacients such as mifepristone (RU 486), and 3) cervical ripening prior to abortion with the use of both mifepristone and prostaglandins. Technical methods of achieving termination of pregnancy continue to be similar in the United States, the United Kingdom, and Europe, although induction-abortion times are generally slower in Europe than in the United States. Surgically, dilatation and evacuation procedures continue to be more common in the United States than in other countries. The effectiveness of mifepristone is undisputed, and the recommended dose for early first-trimester termination is being compared with lower dose alternative regimens. There is additional evidence that at least in the short term, the negative psychological sequelae of abortion are infrequent and are inconsequential as a public health issue. PMID:1504270

  14. Birth, meaningful viability and abortion.

    PubMed

    Jensen, David

    2015-06-01

    What role does birth play in the debate about elective abortion? Does the wrongness of infanticide imply the wrongness of late-term abortion? In this paper, I argue that the same or similar factors that make birth morally significant with regard to abortion make meaningful viability morally significant due to the relatively arbitrary time of birth. I do this by considering the positions of Mary Anne Warren and José Luis Bermúdez who argue that birth is significant enough that the wrongness of infanticide does not imply the wrongness of late-term abortion. On the basis of the relatively arbitrary timing of birth, I argue that meaningful viability is the point at which elective abortion is prima facie morally wrong. PMID:25012846

  15. 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

  16. 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

  17. Teenage pregnancies and abortion.

    PubMed

    Morgenthau, J E

    1984-01-01

    The issue of abortion, except when it is rendered moot because the fetus endangers the life of the mother, is not really a medical issue. The physician's role is to help patients achieve and maintain their maximum potential for physical, mental, and social well-being. To accomplish this, the physician must acquire a constantly evolving database of scientific knowledge, must evaluate this information in a critical and ethical manner, and must be prepared to apply what is learned. In the realm of applied ethics, no particular religion, profession, culture, class, or sex should be thought of as having all the answers in the realm of applied ethics. This physician's actions are predicated on the belief that, to a large extent, ethical precepts reflect the broader social and economic issues of the period in which they are articulated. If this is the case, then in today's world the population explosion, the postindustrial society, the women's rights movement, inequality of access, and the ability to perform prenatal diagnosis are all factors which have molded the approach to the issue of abortion. Only the last 3 of these can in any way be considered as medical. When considering the role of a physician in dealing with the issue of abortion in the adolescent, this individual relies on the concept articulated by the World Health Association (WHA): promoting the physical, emotional, and social well-being of one's patients. Each year in the US over 1 million 15-19 year olds become pregnant, resulting in over 600,000 births. Most of these pregnancies are unintentional, yet approximately 90% of the infants are kept in the home by mothers who are ill prepared to be parents. What is most disturbing is that the pregnancy rate for the younger mother, 16 years or under, is accounting for an ever increasing percentage of the total. Studies at the Adolescent Health Center of the Mount Sinai Hospital in New York City as well as national studies suggest that the younger teens are more

  18. Identification and persistence of Pinus pollen DNA on cotton fabrics: A forensic application.

    PubMed

    Schield, Cassandra; Campelli, Cassandra; Sycalik, Jennifer; Randle, Christopher; Hughes-Stamm, Sheree; Gangitano, David

    2016-01-01

    Advances in plant genomics have had an impact on the field of forensic botany. However, the use of pollen DNA profiling in forensic investigations has yet to be applied. Five volunteers wore a jacket with Pinus echinata pollen-containing cotton swatches for a 14-day period. Pollen decay was evaluated at days 0, 3, 6, 9 and 14 by microscopy. Pollen grains were then transferred to slides using a portable forensic vacuum handle. Ten single grains per swatch were isolated for DNA analysis. DNA was extracted using a high throughput extraction method. A nine-locus short tandem repeat (STR) multiplex system, including previously published primers from Pinus taeda, was developed. DNA was amplified by PCR using fluorescent dyes and analyzed by capillary electrophoresis. Pollen counts from cotton swatches in a 14-day period exhibited an exponential decay from 100% to 17%. The success rate of PCR amplification was 81.2%. Complete and partial STR profiles were generated from 250 pollen grains analyzed (44% and 37%, respectively). Due to the limited amount of DNA, drop-in events were observed (1.87%). However, the rate of contamination with pollen from other pine individuals originating from environmental sources was 4.4%. In conclusion, this study has shown that pollen can be a stable source of forensic DNA evidence, as a proof-of-principle, and that may persist on cotton clothing for at least 14 days of wear. This method can be applied in forensic cases where pollen grains larger than 10 μm (e.g., from herbs or trees) may be transferred to clothing (worn by suspect or victim) by primary contact. PMID:26746823

  19. Intercellular communication in Arabidopsis thaliana pollen discovered via AHG3 transcript movement from the vegetative cell to sperm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An Arabidopsis pollen grain (male gametophyte) consists of three cells: the vegetative cell, which forms the pollen tube, and two sperm cells enclosed within the vegetative cell. It is still unclear if there is intercellular communication between the vegetative cell and the sperm cells. Here we show...

  20. 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

  1. [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

  2. 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

  3. Pollen--tiny and ephemeral but not forgotten: New ideas on their ecology and evolution.

    PubMed

    Williams, Joseph H; Mazer, Susan J

    2016-03-01

    Ecologists and evolutionary biologists have been interested in the functional biology of pollen since the discovery in the 1800s that pollen grains encompass tiny plants (male gametophytes) that develop and produce sperm cells. After the discovery of double fertilization in flowering plants, botanists in the early 1900s were quick to explore the effects of temperature and maternal nutrients on pollen performance, while evolutionary biologists began studying the nature of haploid selection and pollen competition. A series of technical and theoretic developments have subsequently, but usually separately, expanded our knowledge of the nature of pollen performance and how it evolves. Today, there is a tremendous diversity of interests that touch on pollen performance, ranging from the ecological setting on the stigma, structural and physiological aspects of pollen germination and tube growth, the form of pollen competition and its role in sexual selection in plants, virus transmission, mating system evolution, and inbreeding depression. Given the explosion of technical knowledge of pollen cell biology, computer modeling, and new methods to deal with diversity in a phylogenetic context, we are now more than ever poised for a new era of research that includes complex functional traits that limit or enhance the evolution of these deceptively simple organisms. PMID:26980838

  4. Palynology after Y2K--Understanding the Source Area of Pollen in Sediments

    NASA Astrophysics Data System (ADS)

    Davis, M. B.

    Pollen grains preserved in lake and bog sediment provide a record of past vegetation that has been an important source of information about climate and land cover during the Quaternary Period. Yet from the beginning, questions have been raised about the source area of pollen in sediment. Interpretation has been hampered by the lack of well-developed theory treating the relationship between the spatial distribution of trees on the landscape and the percentages of pollen in sediment. Within the past decade, however, new theory, models, and empirical data show how heterogeneous vegetation is represented by pollen. The distinction between "local" and "regional" pollen is explained by the Prentice-Sugita dispersal/deposition models, which predict how the ratio of regional to local pollen changes with lake size. Sugita's model simulating a landscape with heterogeneous vegetation predicts the size of the relevant source area-the area of vegetation reflected in between-lake variations in pollen loading-while demonstrating that regional pollen from beyond this distance is homogeneous at all lakes of similar size. By predicting the way landscape patterns will be reflected in pollen records, simulation models can improve research design and lead to more detailed and spatially precise records of past vegetation, enhancing continental-scale climate reconstructions.

  5. Effects of Ion Implantation on in Vitro Pollen Germination and Cellular Organization of Pollen Tube in Pinus thunbergii Parl. (Japanese Black Pine)

    NASA Astrophysics Data System (ADS)

    Li, Guoping; Huang, Qunce; Yang, Lusheng; Dai, Ximei; Qin, Guangyong; Huo, Yuping

    2006-09-01

    Low-energy ion implantation, as a new technology to produce mutation in plant breeding, has been widely applied in agriculture in China. But so far there is a little understanding of the underlying mechanisms responsible for its biological effects at the cellular level. Here we report the biological effects of a nitrogen ion beams of 30 keV on the pollen grains of Pinus thunbergii Parl. In general, ion implantation inhibited pollen germination. The dose-response curve presented a particular saddle-like pattern. Ion implantation also changed the dimension of the elongated tubes and significantly induced tip swelling. Confocal microscopy indicated that the pollen tube tips in P. thunbergii contained an enriched network of microtubules. Ion implantation led to the disruption of microtubules especially in swollen tips. Treatment with colchicine demonstrated that tip swelling was caused by the disruption of microtubules in the tip, indicating a unique role for microtubules in maintaining the tip integrality of the pollen tube in conifer. Our results suggest that ion implantation induce the disruption of microtubule organization in pollen and pollen tubes and subsequently cause morphological abnormalities in the pollen tubes. This study may provide a clue for further investigation on the interaction between low-energy ion beams and pollen tube growth.

  6. 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

  7. 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

  8. 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

  9. 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

  10. [Psychological aspects of induced abortion].

    PubMed

    Mouniq, C; Moron, P

    1982-06-01

    Results are presented of a literature review to identify social and psychological aspects of abortion. The literature does not provide a true profile of women requesting abortions, but some characteristics emerge. Reasons for requesting abortion include economic problems, difficult previous pregnancies, general medical contraindications to pregnancy, marital conflicts, feelings of loneliness, professional aspirations, problems with existing children, and feelings of insecurity about the future. However, the same feelings are found among women carrying their pregnancies to term. Unplanned pregnancies are more common during periods of depression. Most authors have found about 1/2 of women seeking abortions to be single and about 1/2 to be under 25 years old. Religion does not appear to be a determining factor. 1 study of psychological factors in abortion seekers found that a large number of single women seeking abortion had suffered traumatic experiences in childhood and were seeking security in inappropriate amorous relationships. Helene Deutsch stressed the destructive impulses latent in all pregnancies. Others have cited the ambivalence of the desire for pregnancy and feelings of loss after abortion. Studies published after legalization of abortion in the US and France however have stressed the nearly total absence of moderate or severe psychiatric symptoms after abortion. Responses immediately after the abortion may include feelings of relief, guilt, indifference, or ambivalence. Secondary affects appear minor to most authors. Psychological effects do not appear to be influenced by age, marital status, parity, intelligence, occupation, existence of a later pregnancy, or concommitant sterilization. "Premorbidity" and coercion by spouse or family were most closely associated with psychological symptoms. Numerous authors have found about twice as many negative reactions among women undergoing abortion for medical reasons. Most patients undergoing abortions for

  11. 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

  12. Herpesviral abortion in domestic animals.

    PubMed

    Smith, K C

    1997-05-01

    Abortion or neonatal disease may follow infection with several alpha, beta and gamma-herpesviruses. The alpha-herpesvirus, equid herpesvirus-1 (EHV-1), causes single or epizootic abortions or neonatal deaths in equids, and the closely related virus EHV-4 causes sporadic equine abortions. In cattle, the alpha-herpesviruses, bovine herpesvirus-1 (infectious bovine rhinotracheitis virus) and bovine herpesvirus-5 (bovine encephalitis virus), and a gamma-herpesvirus, bovine herpesvirus-4, have all been implicated as causes of abortion. In pigs, suid herpesvirus-1 (SHV-1: pseudorabies virus), an alpha-herpesvirus, and SHV-2 (porcine cytomegalovirus), a beta-herpesvirus, each cause abortion or neonatal piglet losses. Caprine herpesvirus-1, canine herpesvirus and feline herpesvirus-1, all alpha-herpesviruses, cause abortions or neonatal deaths in goats, dogs and cats, respectively. This review discusses the pathogenesis, pathology and laboratory diagnosis of these herpesviral abortions and neonatal diseases, with an emphasis on experimental studies of each disease. Alternative reviews covering other aspects of each infection, such as the genetic and antigenic structure of the viruses, host immune responses and approaches to vaccination and disease control are indicated at appropriate points in the text. PMID:9232116

  13. Republic of Ireland: abortion controversy.

    PubMed

    1998-01-01

    The problems associated with illegal abortion dominate public discussion in Ireland. While abortion is illegal in Ireland, the Supreme Court directed in 1992 that Irish women can go to Britain for abortions when their lives are thought to be at risk. Abortion was a constant feature during the Irish Presidential election campaign in October, while a dispute about the future of a 13-year-old girl's pregnancy dominated the headlines in November. The presidential election on October 30 resulted in a victory for one of the two openly anti-choice candidates, Mary McAleese, a lawyer from Northern Ireland. With a voter turnout of 47.6%, McAleese polled 45.2% of the votes cast. Although the president may refuse to sign bills which have been passed by parliament, McAleese has said that she will sign whatever bill is placed before her, even if it liberalizes abortion law in the republic. As for the case of the 13-year-old pregnant girl, she was taken into the care of Irish health authority officials once the case was reported to the police. However, the health board, as a state agency, is prevented by Irish law from helping anyone travel abroad for abortion. The girl was eventually given leave in a judgement by a High Court Judicial Review on November 28 to travel to England for an abortion. PMID:12321445

  14. Neighbourhood density and genetic relatedness interact to determine fruit set and abortion rates in a continuous tropical tree population

    PubMed Central

    Jones, F.A; Comita, L.S

    2008-01-01

    Tropical trees may show positive density dependence in fruit set and maturation due to pollen limitation in low-density populations. However, pollen from closely related individuals in the local neighbourhood might reduce fruit set or increase fruit abortion in self-incompatible tree species. We investigated the role of neighbourhood density and genetic relatedness on individual fruit set and abortion in the neotropical tree Jacaranda copaia in a large forest plot in central Panama. Using nested neighbourhood models, we found a strong positive effect of increased conspecific density on fruit set and maturation. However, high neighbourhood genetic relatedness interacted with density to reduce total fruit set and increase the proportion of aborted fruit. Our results imply a fitness advantage for individuals growing in high densities as measured by fruit set, but realized fruit set is lowered by increased neighbourhood relatedness. We hypothesize that the mechanism involved is increased visitation by density-dependent invertebrate pollinators in high-density populations, which increases pollen quantity and carry-over and increases fruit set and maturation, coupled with self-incompatibility at early and late stages due to biparental inbreeding that lowers fruit set and increases fruit abortion. Implications for the reproductive ecology and conservation of tropical tree communities in continuous and fragmented habitats are discussed. PMID:18713714

  15. 28 CFR 551.23 - Abortion.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Abortion. 551.23 Section 551.23 Judicial..., Pregnancy, Child Placement, and Abortion § 551.23 Abortion. (a) The inmate has the responsibility to decide either to have an abortion or to bear the child. (b) The Warden shall offer to provide each...

  16. 28 CFR 551.23 - Abortion.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Abortion. 551.23 Section 551.23 Judicial..., Pregnancy, Child Placement, and Abortion § 551.23 Abortion. (a) The inmate has the responsibility to decide either to have an abortion or to bear the child. (b) The Warden shall offer to provide each...

  17. 28 CFR 551.23 - Abortion.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Abortion. 551.23 Section 551.23 Judicial..., Pregnancy, Child Placement, and Abortion § 551.23 Abortion. (a) The inmate has the responsibility to decide either to have an abortion or to bear the child. (b) The Warden shall offer to provide each...

  18. 28 CFR 551.23 - Abortion.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Abortion. 551.23 Section 551.23 Judicial..., Pregnancy, Child Placement, and Abortion § 551.23 Abortion. (a) The inmate has the responsibility to decide either to have an abortion or to bear the child. (b) The Warden shall offer to provide each...

  19. 28 CFR 551.23 - Abortion.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Abortion. 551.23 Section 551.23 Judicial..., Pregnancy, Child Placement, and Abortion § 551.23 Abortion. (a) The inmate has the responsibility to decide either to have an abortion or to bear the child. (b) The Warden shall offer to provide each...

  20. Induced abortion and contraception use

    PubMed Central

    du Prey, Beatrice; Talavlikar, Rachel; Mangat, Rupinder; Freiheit, Elizabeth A.; Drummond, Neil

    2014-01-01

    Abstract Objective To determine what proportion of women seeking induced abortion in the Calgary census metropolitan area were immigrants. Design For 2 months, eligible women were asked to complete a questionnaire. Women who refused were asked to provide their country of birth (COB) to assess for selection bias. Setting Two abortion clinics in Calgary, Alta. Participants Women presenting at or less than 15 weeks’ gestational age for induced abortion for maternal indications. Main outcome measures The primary outcome was the proportion of women seeking induced abortion services who were immigrants. Secondary outcomes compared socioeconomic characteristics and contraception use between immigrant and Canadian-born women. Results A total of 752 women either completed a questionnaire (78.6%) or provided their COB (21.4%). Overall, 28.9% of women living in the Calgary census metropolitan area who completed the questionnaire were immigrants, less than the 31.2% background proportion of immigrant women of childbearing age. However, 46.0% of women who provided only COB were immigrants. When these data were combined, 34.2% of women presenting for induced abortion identified as immigrant, a proportion not significantly different from the background proportion (P = .127). Immigrant women presenting for induced abortion tended to be older, more educated, married with children, and have increased parity. They were similar to Canadian-born women in number of previous abortions, income status, and employment status. Conclusion This study suggests that immigrant women in Calgary are not presenting for induced abortion in disproportionately higher numbers, which differs from existing European literature. This is likely owing to differing socioeconomic characteristics among the immigrant women in our study from what have been previously described in the literature (typically lower socioeconomic status). Much still needs to be explored with regard to factors influencing the use of

  1. New German abortion law agreed.

    PubMed

    Karcher, H L

    1995-07-15

    The German Bundestag has passed a compromise abortion law that makes an abortion performed within the first three months of pregnancy an unlawful but unpunishable act if the woman has sought independent counseling first. Article 218 of the German penal code, which was established in 1871 under Otto von Bismarck, had allowed abortions for certain medical or ethical reasons. After the end of the first world war, the Social Democrats tried to legalize all abortions performed in the first three months of pregnancy, but failed. In 1974, abortion on demand during the first 12 weeks was declared legal and unpunishable under the social liberal coalition government of chancellor Willy Brandt; however, the same year, the German Federal Constitution Court in Karlsruhe ruled the bill was incompatible with article 2 of the constitution, which guarantees the right to life and freedom from bodily harm to everyone, including the unborn. The highest German court also ruled that a pregnant woman had to seek a second opinion from an independent doctor before undergoing an abortion. A new, extended article 218, which included a clause giving social indications, was passed by the Bundestag. When Germany was unified, East Germans agreed to be governed by all West German laws, except article 218. The Bundestag was given 2 years to revise the article; however, in 1993, the Federal Constitution Court rejected a version legalizing abortion in the first 3 months of the pregnancy if the woman sought counsel from an independent physician, and suggested the recent compromise passed by the Bundestag, the lower house of the German parliament. The upper house, the Bundesrat, where the Social Democrats are in the majority, still has to pass it. Under the bill passed by the Bundestag, national health insurance will pay for an abortion if the monthly income of the woman seeking the abortion falls under a certain limit. PMID:7613423

  2. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice1[OPEN

    PubMed Central

    Wu, Jinwen; Chen, Lin; Chen, Zhixiong; Wang, Lan; Lu, Yonggen

    2015-01-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (SiSj) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. PMID:26511913

  3. RNA Silencing of Exocyst Genes in the Stigma Impairs the Acceptance of Compatible Pollen in Arabidopsis1[OPEN

    PubMed Central

    Safavian, Darya; Indriolo, Emily; Chapman, Laura; Ahmed, Abdalla

    2015-01-01

    Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We hypothesized that EXO70A1, along with other exocyst subunits, functions in the Brassicaceae dry stigma to deliver cargo-bearing secretory vesicles to the stigmatic papillar plasma membrane, under the pollen attachment site, for pollen hydration and pollen tube entry. Here, we investigated the functions of exocyst complex genes encoding the remaining seven subunits, SECRETORY3 (SEC3), SEC5, SEC6, SEC8, SEC10, SEC15, and EXO84, in Arabidopsis stigmas following compatible pollinations. Stigma-specific RNA-silencing constructs were used to suppress the expression of each exocyst subunit individually. The early postpollination stages of pollen grain adhesion, pollen hydration, pollen tube penetration, seed set, and overall fertility were analyzed in the transgenic lines to evaluate the requirement of each exocyst subunit. Our findings provide comprehensive evidence that all eight exocyst subunits are necessary in the stigma for the acceptance of compatible pollen. Thus, this work implicates a fully functional exocyst complex as a component of the compatible pollen response pathway to promote pollen acceptance. PMID:26443677

  4. 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

  5. Abortion-seeking behaviour among Nigerian women.

    PubMed

    Bankole, Akinrinola; Sedgh, Gilda; Oye-Adeniran, Boniface A; Adewole, Isaac F; Hussain, Rubina; Singh, Susheela

    2008-03-01

    This study used data from a community-based survey to examine women's experiences of abortion in Nigeria. Fourteen percent of respondents reported that they had ever tried to terminate a pregnancy, and 10% had obtained an abortion. The majority of women who sought an abortion did so early in the pregnancy. Forty-two percent of women who obtained an abortion used the services of a non-professional provider, a quarter experienced complications and 9% sought treatment for complications from their abortions. Roughly half of the women who obtained an abortion used a method other than D&C or MVA. The abortion prevalence and conditions under which women sought abortions varied by women's socio-demographic characteristics. Because abortion is illegal in Nigeria except to save the woman's life, many women take significant risks to terminate unwanted pregnancies. Reducing the incidence of unwanted pregnancy and unsafe abortion can significantly impact the reproductive health of women in Nigeria. PMID:17711597

  6. Mechanosensitive channel MSL8 regulates osmotic forces during pollen hydration and germination.

    PubMed

    Hamilton, Eric S; Jensen, Gregory S; Maksaev, Grigory; Katims, Andrew; Sherp, Ashley M; Haswell, Elizabeth S

    2015-10-23

    Pollen grains undergo dramatic changes in cellular water potential as they deliver the male germ line to female gametes, and it has been proposed that mechanosensitive ion channels may sense the resulting mechanical stress. Here, we identify and characterize MscS-like 8 (MSL8), a pollen-specific, membrane tension-gated ion channel required for pollen to survive the hypoosmotic shock of rehydration and for full male fertility. MSL8 negatively regulates pollen germination but is required for cellular integrity during germination and tube growth. MSL8 thus senses and responds to changes in membrane tension associated with pollen hydration and germination. These data further suggest that homologs of bacterial MscS have been repurposed in eukaryotes to function as mechanosensors in multiple developmental and environmental contexts. PMID:26494758

  7. 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.

  8. 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.

  9. 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

  10. The long range transport of birch (Betula) pollen from Poland and Germany causes significant pre-season concentrations in Denmark

    NASA Astrophysics Data System (ADS)

    Ambelas Skjoth, C.; Sommer, J.; Stach, A.; Smith, M.; Brandt, J.; Christensen, J. H.; Frohn, L. M.; Geels, C.; Hansen, K. M.; Hedegaard, G. B.

    2009-04-01

    In Denmark, where birch pollen is considered to be among the most important allergenic pollen, about one million people suffer from seasonal allergic rhinitis. In Denmark, the official reported pollen forecast is based on the daily weather forecast, the pollen calendar and local 24-h measurements. Birch pollen has the potential for long-range transport but the present Danish pollen forecast does not account for birch pollen being transported into the country from distant sources.. Long-range transport episodes are intermittent and often out of the main pollen season, where individuals in general will be medically unprotected. Here we use an integrated approach to investigate whether or not Denmark receives significant quantities of birch pollen from Poland and Germany before local trees start to flower. In 2006 we used a combination of phenological observations and pollen measurements in Poland (Poznań) and Denmark (Copenhagen). Seasonal and diurnal variations in birch pollen measurement from Copenhagen (2000-2006) were examined with the aim of identifying pre-seasonal episodes originating from long-range transport. The 2.5% accumulation method was used for identifying start of season. If daily pollen counts exceeded 30 grains/m3 either before the local flowering season began or on the actual start day, the episode was chosen for investigation with back trajectory analysis. A birch forest inventory for Northern Europe was produced and implemented in DEHM-Pollen along with a simple unified pollen release model SUPREME to investigate the 2006 campaign in detail. In 2006, full flowering took place in Poznan between 20th and 28th of April and daily concentrations varied between 739 and 2169 grains/m3. In Copenhagen phenological observations showed that local flowering was initiated the 2nd of May. In Copenhagen several episodes with pollen concentrations at 108, 244 and 41 grains/m3 were recorded the 23rd, 26th and 27th of April, respectively. Back-trajectory analysis

  11. The spatial and temporal distribution of pollen in a room: forensic implications.

    PubMed

    Morgan, R M; Allen, E; King, T; Bull, P A

    2014-01-01

    This paper presents two experimental studies that deal with the spatial and temporal distribution of pollen grains within a room of a domestic dwelling. The findings concur with the preliminary work of Morgan et al. [1] and provide greater detail as to the behaviour of pollen grains within indoor locations that are pertinent for forensic investigations. The spatial distribution of pollen in a room exhibits strong distance decay trends, with the majority of pollen recovered within 0.8m of its source. The pollen was found to persist in increasing quantities during the time the flowers were in the room. This study also shows that 20days after the flowers were removed, 25-32% of the original pollen was still present within the room. The influence of disturbance was investigated and whilst areas of high disturbance were found to retain less pollen than undisturbed locations, the influence of the proximity to source was a more dominant factor. These findings have significant implications for forensic investigation protocols, particularly the collection and interpretation phases of trace evidence analysis. The distribution of pollen around a room ensures that viable sources of trace pollen are available for transfer if contact is made between a location in the room and a suspect. The persistence of pollen many days after the flowers have been removed from a room indicates that many rooms in domestic dwellings will have distinctive assemblages that reflect the history of the flowers that have been displayed within that room in the past, and that these assemblages will persist and therefore be available for transfer. These preliminary findings indicate that investigation by forensic palynology in indoor domestic settings may well be an underutilised technique that has the potential to provide accurate and valuable intelligence and evidence for forensic enquiry. PMID:24438777

  12. Examining Ambrosia pollen episodes at Poznań (Poland) using back-trajectory analysis

    NASA Astrophysics Data System (ADS)

    Stach, A.; Smith, M.; Skjøth, C. A.; Brandt, J.

    2007-03-01

    The pollen grains of Ambrosia spp. are considered to be important aeroallergens in parts of southern and central Europe. Back-trajectories have been analysed with the aim of finding the likely sources of Ambrosia pollen grains that arrived at Poznań (Poland). Temporal variations in Ambrosia pollen at Poznań from 1995-2005 were examined in order to identify Ambrosia pollen episodes suitable for further investigation using back-trajectory analysis. The trajectories were calculated using the transport model within the Lagrangian air pollution model, ACDEP (Atmospheric Chemistry and Deposition). Analysis identified two separate populations in Ambrosia pollen episodes, those that peaked in the early morning between 4 a.m. and 8 a.m., and those that peaked in the afternoon between 2 p.m. and 6 p.m.. Six Ambrosia pollen episodes between 2001 and 2005 were examined using back-trajectory analysis. The results showed that Ambrosia pollen episodes that peaked in the early morning usually arrived at Poznań from a southerly direction after passing over southern Poland, the Czech Republic, Slovakia and Hungary, whereas air masses that brought Ambrosia pollen to Poznań during the afternoon arrived from a more easterly direction and predominantly stayed within the borders of Poland. Back-trajectory analysis has shown that there is a possibility that long-range transport brings Ambrosia pollen to Poznań from southern Poland, the Czech Republic, Slovakia and Hungary. There is also a likelihood that Ambrosia is present in Poland, as shown by the arrival of pollen during the afternoon that originated primarily from within the country.

  13. Launch Abort System Pathfinder Arrival

    NASA Video Gallery

    The Orion Launch Abort System, or LAS, pathfinder returned home to NASA Langley on Oct. 18 on its way to NASA's Kennedy Space Center. The hardware was built at Langley and was used in preparation f...

  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. The Development of Instruments to Measure Attitudes toward Abortion and Knowledge of Abortion

    ERIC Educational Resources Information Center

    Snegroff, Stanley

    1976-01-01

    This study developed an abortion attitude scale and abortion knowledge inventory that may be utilized by health educators, counselors, and researchers for assessing attitudes toward abortion and knowledge about it. (SK)

  16. Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae) Species and Their Spontaneous Hybrids

    PubMed Central

    Danielewicz, Władysław; Bocianowski, Jan; Maliński, Tomasz; Janyszek, Magdalena

    2016-01-01

    Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy. PMID:27564015

  17. Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae) Species and Their Spontaneous Hybrids.

    PubMed

    Wrońska-Pilarek, Dorota; Danielewicz, Władysław; Bocianowski, Jan; Maliński, Tomasz; Janyszek, Magdalena

    2016-01-01

    Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy. PMID:27564015

  18. Participation of nurses in abortions.

    PubMed

    Neustatter, P L

    1980-11-29

    Doctors for a Woman's Choice on Abortion would agree with 1 point in Lord Denning's ruling on the role of nurses in abortions induced by (PGS) prostaglandins (November 15, p. 1091). The nurse should not be doing a doctor's job, as Lord Denning indicated, and we sympathize with any nurse who is doing so (though the 1967 Abortion Act allows any nurse to abstain, on grounds of conscience). However, the ruling that nurses are not legally covered to participate in any way with the "procuring of a miscarriage" (using terminology of the 1861 Offenses against the Persons Act upon which the ruling is based) does not require a radical change in the practice of late abortions (constituting only 7% of the terminations) or any change in the law. PG abortion can be done without a nurse. With the extraamniotic technique, a very cheap pump can be used to give subsequent doses of the PG (a function normally performed by a nurse) through the catheter left inserted through the cervix after the 1st dose has been given by the doctor. Alternatively, the intraamniotic method can be used, where PG is instilled into the amniotic sac via a needle passed through the abdominal wall. This normally requires only 1 dose, given by the doctor. Rarely are subsequent doses needed; however they could be given by the doctor with very little addition to his or her workload. While the fact that PG abortion can be done without nurses is not realized, late abortion will be restricted, a situation which is entirely deplorable. Also deplorable are the comments of an antiabortion nature made by Lord Denning, over and above the legal ruling in his jurisdiction to make. His ruling, furthermore, seems to have been sufficiently confused for the Department of Health to withdraw its circular on abortion and await an interpretation before issuing another. PMID:6107800

  19. Effects of pollen selection on progeny vigor in a Cucurbita pepo x C. texana hybrid.

    PubMed

    Quesada, M; Winsor, J A; Stephenson, A G

    1996-05-01

    We examined the effects of pollen selection for rapid pollen-tube growth on progeny vigor. First, we crossed a wild gourd (Cucurbita texana) to a cultivated zucchini (Cucurbita pepo cv 'Black Beauty') to produce an F1 and then an F2 generation. Half of the F1 seeds were produced by depositing small loads of C. texana pollen onto the stigmas of C. pepo. These small pollen loads were insufficient to produce a full complement of seeds and, consequently, both the fast- and the slow-growing pollen tubes were permitted to achieve fertilization. An F2 generation was then produced by depositing small loads of F1 pollen onto stigmas of F1 plants. The F2 seeds resulting from two generations of small pollen loads are termed the non-selected line because there was little or no selection for pollen-tube growth rate on these plants. The other half of the F1 and F2 seeds were produced by depositing large pollen loads (>10 000 pollen grains) onto stigmas and then allowing only the first 1% or so of the pollen tubes that entered the ovary to fertilize the ovules. We did this by excising the styles at the ovary at 12-15 h after pollination. The resulting F2 seeds are termed 'the selected line' because they were produced by two generations of selection for only the fastest growing pollen tubes. Small pollen loads from the F2plants, both the selected and the non-selected lines, were then deposited onto stigmas of different C. pepo flowers, and the vigor of the resulting seeds was compared under greenhouse and field conditions. The results showed that the seeds fertilized by pollen from the selected line had greater vegetative vigor as seedlings and greater flower and fruit production as mature plants than the seeds fertilized by pollen from the non-selected line. This study demonstrates that selection for fast pollen-tube growth (selection on the microgametophyte) leads to a correlated increase in sporophyte (progeny) vigor. PMID:24166555

  20. Paris court attacks abortion law.

    PubMed

    Dorozynski, A

    1995-07-15

    A Paris court last week challenged a 1993 law that makes it a criminal offense to obstruct abortions. The court acquitted nine anti-abortion protestors who had broken into the maternity ward of the public hospital Pitie-Salpetriere last November and prayed at the entrance of a ward where patients are admitted for abortions. The judges ruled that the protestors had not interfered with abortions being carried out because none were taking place at the time of the demonstration; furthermore, the judges stated, because the fetus could be considered a person (child), the protestors were protected by other laws which give immunity to those breaking a law in order to protect another person's life, or to defend a child that had been abandoned. The court continued to say that a fetus should be protected, whether or not it was considered a person, because it was definitely more than nothing. The Syndicat de la Magistrature, the association of French magistrates, believes the tribunal has denied the right to abortion guaranteed in the 1975 law. Veronique Neietz, who drafted the 1993 law, was "scandalized" by the decision and believes the decision of the court was made in retribution for a recent parliamentary decision to exclude anti-abortion protestors from the general amnesty given after presidential elections to minor offenders. During the same week of this court decision, two tribunals, in Lyons and in Bourg-en-Bresse, sentenced 45 anti-abortionists to suspended prison terms with fines. PMID:7613424

  1. A comparison of classification algorithms within the Classifynder pollen imaging system

    NASA Astrophysics Data System (ADS)

    Lagerstrom, Ryan; Arzhaeva, Yulia; Bischof, Leanne; Haberle, Simon; Hopf, Felicitas; Lovell, David

    2013-10-01

    We describe an investigation into how Massey University's Pollen Classifynder can accelerate the understanding of pollen and its role in nature. The Classifynder is an imaging microscopy system that can locate, image and classify slide based pollen samples. Given the laboriousness of purely manual image acquisition and identification it is vital to exploit assistive technologies like the Classifynder to enable acquisition and analysis of pollen samples. It is also vital that we understand the strengths and limitations of automated systems so that they can be used (and improved) to compliment the strengths and weaknesses of human analysts to the greatest extent possible. This article reviews some of our experiences with the Classifynder system and our exploration of alternative classifier models to enhance both accuracy and interpretability. Our experiments in the pollen analysis problem domain have been based on samples from the Australian National University's pollen reference collection (2890 grains, 15 species) and images bundled with the Classifynder system (400 grains, 4 species). These samples have been represented using the Classifynder image feature set. In addition to the Classifynder's native neural network classifier, we have evaluated linear discriminant, support vector machine, decision tree and random forest classifiers on these data with encouraging results. Our hope is that our findings will help enhance the performance of future releases of the Classifynder and other systems for accelerating the acquisition and analysis of pollen samples.

  2. Pollination of Schisandra henryi (Schisandraceae) by Female, Pollen-eating Megommata Species (Cecidomyiidae, Diptera) in South-central China

    PubMed Central

    Yuan, Liang-Chen; Luo, Yi-Bo; Thien, Leonard B.; Fan, Jian-Hua; Xu, Huan-Li; Chen, Zhi-Duan

    2007-01-01

    Background and Aims The mutualistic interaction between insects and flowers is considered to be a major factor in the early evolution of flowering plants. The Schisandraceae were, until now, the only family in the ANITA group lacking information on pollination biology in natural ecosystems. Thus, the objective of this research was to document the pollination biology and breeding system of Schisandra henryi. Methods Field observations were conducted in three populations of S. henryi and the floral phenology, floral characters and insect activities were recorded. Floral fragrances were sampled in the field and analysed using TCT-GC-MS. Floral thermogenesis was measured with a TR-71U Thermo Recorder. Pollen loads and location of pollen grains on insect bodies (including the gut) were checked with a scanning electron microscope and under a light microscope. Key Results Schisandra henryi is strictly dioecious. Male flowers are similar to female flowers in colour, shape, and size, but more abundant than female flowers. The distance between tepals and the androecium or gynoecium is narrow. Neither male nor female flowers are fragrant or thermogenic. Schisandra henryi is pollinated only by adult female Megommata sp. (Cecidomyiidae, Diptera) that eat the pollen grains as extra nutrition for ovary maturation and ovipositing. Both male and female flowers attract the pollinators using similar visual cues and thus the female flowers use deceit as they offer no food. Conclusions Schisandra henryi exhibits a specialized pollination system, which differs from the generalized pollination system documented in other ANITA members. Pollen is the sole food resource for Megommata sp. and the female flowers of S. henryi attract pollinators by deceit. This is the first report of predacious gall midges utilizing pollen grains as a food source. The lack of floral thermogenesis and floral odours further enforces the visual cues by reducing attractants for other potential pollinators. PMID

  3. In vitro germination characteristics of maize pollen to detect biological activity of environmental pollutants

    SciTech Connect

    Pfahler, P.L.

    1981-01-01

    In vitro pollen germination in maize was evaluated as a method of assessing the mutagenic and physiological effects of environmental pollutants on higher organisms. The extent of mutations was effectively determined by testing sporophytes homozygous for the mutated allele. Physiological effects were effectively determined when chemical agents were added directly into the in vitro medium. Exposure of pollen grains during in vitro germination to ultraviolet radiation in the range 280-320 nm produced little or no change in the germination or rupture percentage but a sharp decrease in pollen tube growth after 1 hr.

  4. Simulated environmental criticalities affect transglutaminase of Malus and Corylus pollens having different allergenic potential.

    PubMed

    Iorio, Rosa Anna; Di Sandro, Alessia; Paris, Roberta; Pagliarani, Giulia; Tartarini, Stefano; Ricci, Giampaolo; Serafini-Fracassini, Donatella; Verderio, Elisabetta; Del Duca, Stefano

    2012-02-01

    Increases in temperature and air pollution influence pollen allergenicity, which is responsible for the dramatic raise in respiratory allergies. To clarify possible underlying mechanisms, an anemophilous pollen (hazel, Corylus avellana), known to be allergenic, and an entomophilous one (apple, Malus domestica), the allergenicity of which was not known, were analysed. The presence also in apple pollen of known fruit allergens and their immunorecognition by serum of an allergic patient were preliminary ascertained, resulting also apple pollen potentially allergenic. Pollens were subjected to simulated stressful conditions, provided by changes in temperature, humidity, and copper and acid rain pollution. In the two pollens exposed to environmental criticalities, viability and germination were negatively affected and different transglutaminase (TGase) gel bands were differently immunodetected with the polyclonal antibody AtPng1p. The enzyme activity increased under stressful treatments and, along with its products, was found to be released outside the pollen with externalisation of TGase being predominant in C. avellana, whose grain presents a different cell wall composition with respect to that of M. domestica. A recombinant plant TGase (AtPng1p) stimulated the secreted phospholipase A(2) (sPLA(2)) activity, that in vivo is present in human mucosa and is involved in inflammation. Similarly, stressed pollen, hazel pollen being the most efficient, stimulated to very different extent sPLA(2) activity and putrescine conjugation to sPLA(2). We propose that externalised pollen TGase could be one of the mediators of pollen allergenicity, especially under environmental stress induced by climate changes. PMID:21847612

  5. 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.

  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. Crew Exploration Vehicle Ascent Abort Overview

    NASA Technical Reports Server (NTRS)

    Davidson, John B., Jr.; Madsen, Jennifer M.; Proud, Ryan W.; Merritt, Deborah S.; Sparks, Dean W., Jr.; Kenyon, Paul R.; Burt, Richard; McFarland, Mike

    2007-01-01

    One of the primary design drivers for NASA's Crew Exploration Vehicle (CEV) is to ensure crew safety. Aborts during the critical ascent flight phase require the design and operation of CEV systems to escape from the Crew Launch Vehicle and return the crew safely to the Earth. To accomplish this requirement of continuous abort coverage, CEV ascent abort modes are being designed and analyzed to accommodate the velocity, altitude, atmospheric, and vehicle configuration changes that occur during ascent. The analysis involves an evaluation of the feasibility and survivability of each abort mode and an assessment of the abort mode coverage. These studies and design trades are being conducted so that more informed decisions can be made regarding the vehicle abort requirements, design, and operation. This paper presents an overview of the CEV, driving requirements for abort scenarios, and an overview of current ascent abort modes. Example analysis results are then discussed. Finally, future areas for abort analysis are addressed.

  8. Assessing the impact of Cry1Ab-expressing corn pollen on monarch butterfly larvae in field studies

    PubMed Central

    Stanley-Horn, Diane E.; Dively, Galen P.; Hellmich, Richard L.; Mattila, Heather R.; Sears, Mark K.; Rose, Robyn; Jesse, Laura C. H.; Losey, John E.; Obrycki, John J.; Lewis, Les

    2001-01-01

    Survival and growth of monarch larvae, Danaus plexippus (L.), after exposure to either Cry1Ab-expressing pollen from three Bacillus thuringiensis (Bt) corn (Zea mays L.) events differing in toxin expression or to the insecticide, λ-cyhalothrin, were examined in field studies. First instars exposed to low doses (≈22 grains per cm2) of event-176 pollen gained 18% less weight than those exposed to Bt11 or Mon810 pollen after a 5-day exposure period. Larvae exposed to 67 pollen grains per cm2 on milkweed leaves from within an event-176 field exhibited 60% lower survivorship and 42% less weight gain compared with those exposed to leaves from outside the field. In contrast, Bt11 pollen had no effect on growth to adulthood or survival of first or third instars exposed for 5 days to ≈55 and 97 pollen grains per cm2, respectively. Similarly, no differences in larval survivorship were observed after a 4-day exposure period to leaves with 504–586 (within fields) or 18–22 (outside the field) pollen grains per cm2 collected from Bt11 and non-Bt sweet-corn fields. However, survivorship and weight gain were drastically reduced in non-Bt fields treated with λ-cyhalothrin. The effects of Bt11 and Mon810 pollen on the survivorship of larvae feeding 14 to 22 days on milkweeds in fields were negligible. Further studies should examine the lifetime and reproductive impact of Bt11 and Mon810 pollen on monarchs after long-term exposure to naturally deposited pollen. PMID:11559839

  9. Abortion restrictions may undermine welfare reform.

    PubMed

    1999-02-01

    Results from a study conducted by Pennsylvania State University's Population Research Institute indicate that more restrictive abortion laws in the US may have led to an increase in the number of single mothers, even given new welfare reform laws which make unmarried childbearing more costly. Study findings are based upon county rates of female-headed families from the 1980 and 1990 censuses, excluding those in Alaska and Hawaii. By making unmarried childbearing more costly, welfare reform has sparked a demand for abortion, while at the same time abortion laws have restricted access to abortion. An increasing number of unmarried women on welfare have therefore chosen childbearing over abortion. The study found a decline in the number of abortions in counties where abortion laws had become more strict. That states can now require abortion providers to notify the parents of minors who have abortions, to restrict Medicaid funding for abortions, and to establish 24-hour waiting periods has made abortion either a difficult or impossible option for some women. These restrictive abortion laws and geographic barriers to abortion have discouraged women from undergoing the procedure, increasing the number of female-headed families and single mothers. The public policy goal of reducing unmarried childbearing and female-headed families is being undermined by the growing geographic and legal barriers designed to discourage abortion. PMID:12348920

  10. Repeat abortions in New York City, 2010.

    PubMed

    Toprani, Amita; Cadwell, Betsy L; Li, Wenhui; Sackoff, Judith; Greene, Carolyn; Begier, Elizabeth

    2015-06-01

    This study aims to describe factors associated with the number of past abortions obtained by New York City (NYC) abortion patients in 2010. We calculated rates of first and repeat abortion by age, race/ethnicity, and neighborhood-level poverty and the mean number of self-reported past abortions by age, race/ethnicity, neighborhood-level poverty, number of living children, education, payment method, marital status, and nativity. We used negative binomial regression to predict number of past abortions by patient characteristics. Of the 76,614 abortions reported for NYC residents in 2010, 57% were repeat abortions. Repeat abortions comprised >50% of total abortions among the majority of sociodemographic groups we examined. Overall, mean number of past abortions was 1.3. Mean number of past abortions was higher for women aged 30-34 years (1.77), women with ≥5 children (2.50), and black non-Hispanic women (1.52). After multivariable regression, age, race/ethnicity, and number of children were the strongest predictors of number of past abortions. This analysis demonstrates that, although socioeconomic disparities exist, all abortion patients are at high risk for repeat unintended pregnancy and abortion. PMID:25779755

  11. 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…

  12. 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.

  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. [Readers' position against induced abortion].

    PubMed

    1981-08-25

    Replies to the request by the Journal of Nursing on readers' positions against induced abortion indicate there is a definite personal position against induced abortion and the assistance in this procedure. Some writers expressed an emotional "no" against induced abortion. Many quoted arguments from the literature, such as a medical dictionary definition as "a premeditated criminally induced abortion." The largest group of writers quoted from the Bible, the tenor always being: "God made man, he made us with his hands; we have no right to make the decision." People with other philosophies also objected. Theosophical viewpoint considers reincarnation and the law of cause and effect (karma). This philosophy holds that induced abortion impedes the appearance of a reincarnated being. The fundamental question in the abortion problem is, "can the fetus be considered a human life?" The German anatomist Professor E. Bleckschmidt points out that from conception there is human life, hence the fertilized cell can only develop into a human being and is not merely a piece of tissue. Professional nursing interpretation is that nursing action directed towards killing of a human being (unborn child) is against the nature and the essence of the nursing profession. A different opinion states that a nurse cares for patients who have decided for the operation. The nurse doesn't judge but respects the individual's decision. Some proabortion viewpoints considered the endangering of the mother's life by the unborn child, and the case of rape. With the arguments against abortion the question arises how to help the woman with unwanted pregnancy. Psychological counseling is emphasized as well as responsible and careful assistance. Referral to the Society for Protection of the Unborn Child (VBOK) is considered as well as other agencies. Further reader comments on this subject are solicited. PMID:6913282

  15. House subcmte. tightens abortion language.

    PubMed

    1978-05-10

    Medicaid would help pay for abortion in fewer circumstances under the fiscal 1979 Department of Health, Education, and Welfare (HEW), appropriations bill approved May 4, 1978, by the House HEW Appropriations Subcommittee than it did in 1978. The new language would permit the funding only if the mother's life would be endangered if the pregnancy were carried to term. Current law permits abortion payments for this reason; if pregnancy results from rape or incest, or if the birth would cause the mother severe and long-lasting physical damage. Behind the scenes pressure probably will be applied to resolve the issue quickly this year since all House members are up for reelection and do not want to have such a sensitive issue intruding on their campaigns. 1 strategy being discussed is the inclusion of riders that would directly or indirectly provide federal funds for abortions in other appropriation measures such as funding for the Defense Department and federal employees health benefits. The House will have to contend with Senator Brooke (R-Massachusetts) ranking minority member on the Senate HEW Appropriations Subcommittee, who is determined to stand firm in favor of liberal abortion funding. With only minimal opposition for his Senate seat this year, Senate staffers say Brooke is not concerned with the possibility of abortion becoming a major campaign issue. It was Brooke who forced the House's hand last year and obtained a more relaxed abortion curb, much to the chagrin of the Carter Administration. The White House, with the President's popularity at a low ebb, would prefer not to be put in a position of taking sides publicly although it prefers the strict curbs. Carter is currently deciding which House members to assist during the campaign and such a no-win issue would only serve to complicate matters. He will have enough of a problem reconciling health spending increases without the added burden of abortion. PMID:12335662

  16. Contraception and abortion in two Vietnamese communes.

    PubMed Central

    Gorbach, P M; Hoa, D T; Nhan, V Q; Tsui, A

    1998-01-01

    OBJECTIVES: The authors examined factors predicting abortion use in two communes in northern Vietnam. METHODS: A survey of 504 rural and 523 urban women of childbearing age was conducted. RESULTS: For the 13.6% of urban and 19% of rural commune women having had an abortion in the previous year, logistic regression analyses demonstrated that use of an intrauterine device reduced the likelihood of subsequent abortion in both communes. Traditional method use in the rural commune, however, increased women's likelihood of a subsequent abortion. CONCLUSIONS: Contraceptive use in these 2 communes affected abortion more than sociodemographic factors. Traditional method use by rural women is a risk for abortion. PMID:9551014

  17. 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

  18. Abortion and the law: the Supreme Court, privacy, and abortion.

    PubMed

    Marsh, F H

    1997-01-01

    This article examines the impact of the continuing politicization of the abortion issue in the US on the rights of women and on the emerging concept of fetal rights. The introduction 1) attributes the "final and total politicization" of a woman's right to control her reproduction to the "undue burden" standard introduced by the Supreme Court in its 1992 Casey decision and 2) claims that, if unchecked, the concept of fetal rights may give the state's interest in protecting potential life supremacy over women's rights. The next section presents an in-depth discussion of the politicization of the right to abortion that covers such topics as how the courts before Casey became the forum for debating abortion policy, how the "undue burden" standard fails to set definite parameters of acceptable state behavior, how the Casey decision in effect abandons the trimester-based framework of reference provided in Roe vs. Wade, how Casey allows states to subtly coerce women seeking abortions, how the Casey decision failed to reduce the intense politicization of abortion, and how the court failed to protect individual rights to health care and abortion funding from states. Part 3 of the article begins its exploration of the concept of "fetal rights" with a sketch of the history of this concept in the US courts starting in 1884 when damages for miscarriage were denied. Ways in which fetal rights compete with the rights of a pregnant woman are described, the Supreme Court is blamed for allowing states to develop this concept, and issues of patient confidentiality versus reporting requirements are considered. It is concluded that the Supreme Court will have to act to limit fetal rights. PMID:12348324

  19. Global consequences of unsafe abortion.

    PubMed

    Singh, Susheela

    2010-11-01

    Unsafe abortion is a significant cause of death and ill health in women in the developing world. A substantial body of research on these consequences exists, although studies are of variable quality. However, unsafe abortion has a number of other significant consequences that are much less widely recognized. These include the economic consequences, the immediate costs of providing medical care for abortion-related complications, the costs of medical care for longer-term health consequences, lost productivity to the country, the impact on families and the community, and the social consequences that affect women and families. This article will review the scientific evidence on the consequences of unsafe abortion, highlight gaps in the evidence base, suggest areas where future research efforts are needed, and speculate on the future situation regarding consequences and evidence over the next 5-10 years. The information provided is useful and timely given the current heightened interest in the issue of unsafe abortion, growing from the recent focus of national and international agencies on reducing maternal mortality by 75% by 2015 (as one of the Millennium Development Goals established in 2000). PMID:21118043

  20. 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

    • Background and Aims The phylogenetic affinities of the aberrant monotypic genus Duparquetia (subfamily Caesalpinioideae) are at present unresolved. Preliminary results from molecular analyses suggest a basal, isolated position among legumes. A study of Duparquetia pollen was carried out to provide further morphological characters to contribute to multi-data set analyses. Understanding the development of Duparquetia pollen was necessary to clarify the orientation of the apertures. • Methods Pollen grains and developing microspores were examined using light microscopy, confocal microscopy and scanning electron microscopy. Evidence for the orientation of the apertures was provided by the examination of microspores within developing tetrads, using (a) confocal microscopy to locate the position of the ectoapertures, and (b) light microscopy and Alcian blue stain to locate the position of the endoapertures. • Key Results Confocal microscopy has been used for the first time to examine developing microspores in order to obtain information on ectoapertures that was unavailable using other techniques. Pollen in Duparquetia develops in tetrahedral tetrads as in other eudicots, with the apertures arranged in a modified pattern following Fischer's rule. Pollen grains are asymmetrical and have one equatorial-encircling ectoaperture with two equatorial endoapertures, a unique feature in Leguminosae, and in eudicots. • Conclusions The pollen morphology of Duparquetia is so unusual that it provides little information to help determine its closest relatives. However, it does fit with a pattern of greater pollen morphological diversity in the first-branching caesalpinioid legume groups than in the more derived clades. The latitudinal ectoaperture of Duparquetia is unique within the Fabales and eudicot clades, resembling more closely the monosulcate pollen found in monocots and basal angiosperms; however, developmental patterns are recognizably similar to those of all other

  1. 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

  2. Betula Pollen Influx as an Indicator of Holocene Climate Change in Northwest Iceland

    NASA Astrophysics Data System (ADS)

    Eddudóttir, S. D.; Erlendsson, E.; Gísladóttir, G.

    2014-12-01

    Downy birch (Betula pubescens Ehrh.) forest is the natural climax vegetation in Iceland and reconstructions of Holocene forest dynamics can potentially provide important information about climate and environmental change in the North Atlantic. Pollen and macrofossil analysis have been carried out on a lake sediment core from Northwest Iceland, covering the period from the end of Younger Dryas to ca. 3000 cal. yr. BP. Only the most recent Icelandic pollen studies have included Betula pollen influx (pollen grains deposited per cm2 per year). Comparison between the Betula pollen percentages and Betula pollen influx in the core show a different trend between the two methods of data presentation, particularly after birch forest has been established. Both methods show expansion of dwarf birch (Betula nana) dominated shrub heath during the early Holocene. The appearance of downy birch (Betula pubescens) woodland and subsequent decline is also represented by both methods and is supported by the macrofossil record. The expansion of birch forest during the Holocene Thermal Maximum (HTM) is seen from high influx values of more than 2400 Betula grains cm-2 year-1 and Betula percentages above 80%. The influx decreases significantly at ca. 6600 cal. yr. BP and drops to less than 2000 Betula grains cm-2 year-1, decreasing upwards in the core. Betula percentage values become more variable and drop slightly at the same time, but not as prominently as the influx values. The terrestrial response recorded in the Betula pollen influx corresponds to changes apparent in marine cores from Húnaflói bay, and signifies a sensitivity of the Holocene terrestrial ecosystem to climate fluctuations. Betula pollen influx is potentially a sensitive proxy for temperature changes in Iceland and should be included in future palynological studies in order to improve the interpretation of Holocene vegetation and climate changes. The study is funded by the Eimskip University fund, University of Iceland

  3. 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

  4. The Road to Pad Abort 1

    NASA Video Gallery

    At the White Sands Missile Range in Las Cruces, N.M., engineers and technicians are preparing for the Pad Abort 1 flight test. The Launch Abort System is a sophisticated new rocket tower designed t...

  5. Using flow cytometry to estimate pollen DNA content: improved methodology and applications

    PubMed Central

    Kron, Paul; Husband, Brian C.

    2012-01-01

    Background and Aims Flow cytometry has been used to measure nuclear DNA content in pollen, mostly to understand pollen development and detect unreduced gametes. Published data have not always met the high-quality standards required for some applications, in part due to difficulties inherent in the extraction of nuclei. Here we describe a simple and relatively novel method for extracting pollen nuclei, involving the bursting of pollen through a nylon mesh, compare it with other methods and demonstrate its broad applicability and utility. Methods The method was tested across 80 species, 64 genera and 33 families, and the data were evaluated using established criteria for estimating genome size and analysing cell cycle. Filter bursting was directly compared with chopping in five species, yields were compared with published values for sonicated samples, and the method was applied by comparing genome size estimates for leaf and pollen nuclei in six species. Key Results Data quality met generally applied standards for estimating genome size in 81 % of species and the higher best practice standards for cell cycle analysis in 51 %. In 41 % of species we met the most stringent criterion of screening 10 000 pollen grains per sample. In direct comparison with two chopping techniques, our method produced better quality histograms with consistently higher nuclei yields, and yields were higher than previously published results for sonication. In three binucleate and three trinucleate species we found that pollen-based genome size estimates differed from leaf tissue estimates by 1·5 % or less when 1C pollen nuclei were used, while estimates from 2C generative nuclei differed from leaf estimates by up to 2·5 %. Conclusions The high success rate, ease of use and wide applicability of the filter bursting method show that this method can facilitate the use of pollen for estimating genome size and dramatically improve unreduced pollen production estimation with flow cytometry. PMID

  6. Abortion counseling and the school counselor.

    PubMed

    Duncan, J A; Moffett, C F

    1974-01-01

    The Supreme Court decision of January 22, 1973, legalizing abortion now requires school counselors to examine both their personal and professional positions on abortion information and abortion counseling. To date a review of school counseling literature reveals a failure to deal with abortion as a counseling issue. Also, schools have failed to develop official policies regarding abortion counseling and the distribution of abortion information. The counselors who have provided abortion information to date have done so at the request of a student or parent rather than by making the information generally available. A study in 1973 in Virginia, however, revealed that Virginia counselor educators believed that there was a need for counselors in training to be exposed to abortion information as part of their formal training experience. Generally, today's present exposure to abortion information makes it impossible for counselors to continue to ignore a growing demand for both abortion information and counseling. School counselors must deal with the following questions: 1) What course of action should school counselors take when a pregnant young seeks counseling on alternatives to pregnancy continuation? 2) What is the counselor's professional role in abortion counseling with respect to his or her personal feelings and beliefs? 3) What kind of training if any should school counselors receive regarding abortion counseling? 4) Is there a need for in-service training on abortion counseling for school counselors? 5) Should various professional organizations develop materials that would assist their members in providing abortion counseling? 6) Should institutions such as schools, churches, and community agencies establish policies concerning abortion counseling? Although the answers are not simple, the school counselors and their professional organizations must begin to develop the answers in order to provide good counseling services to young women exercising their right to

  7. Procured abortion in Ilorin, Nigeria.

    PubMed

    Anate, M; Awoyemi, O; Oyawoye, O; Petu, O

    1995-06-01

    A prospective study of the maternal mortality and morbidity and other related social problems among 144 cases of procured abortion in Ilorin, Nigeria over a 24-month period is presented. A mortality rate of 90.3 per thousand procured abortions was recorded. Genital sepsis, haemorrhagic anaemia, gut injury, uterine perforation and vesico vaginal fistulae (VVF) were encountered. Poor referral system, late presentation, poor blood transfusion services and inadequate availability of drugs had adverse effects on the patients. The implications (the menace and frequency) of these and possible measures like improving the literacy level, the moral standards, contraceptive practice and family life education (sex education) are discussed. PMID:7498012

  8. Abortion, Moral Maturity and Civic Journalism.

    ERIC Educational Resources Information Center

    Patterson, Maggie Jones; Hall, Megan Williams

    1998-01-01

    Contributes to rhetoric, moral reasonings scholarship, and journalism scholarship by examining public rhetoric on abortion and American popular media coverage (1940s to 1990s). Finds that the feminine means of moral reasoning has emerged into the foreground of discourse on abortion. Compares emergence of a common-ground rhetoric on abortion with a…

  9. Objective versus Subjective Responses to Abortion.

    ERIC Educational Resources Information Center

    Robbins, James M.

    1979-01-01

    Measured psychological sequelae to induced abortion among women pregnant out of wedlock, using the Minnesota Multiphasic Personality Inventory and questions specific to willingness to repeat abortion under similar circumstances. Analyses indicated no relation between objective and subjective indicators. Affectivity after induced abortion had…

  10. Abortion and Mental Health: Evaluating the Evidence

    ERIC Educational Resources Information Center

    Major, Brenda; Appelbaum, Mark; Beckman, Linda; Dutton, Mary Ann; Russo, Nancy Felipe; West, Carolyn

    2009-01-01

    The authors evaluated empirical research addressing the relationship between induced abortion and women's mental health. Two issues were addressed: (a) the relative risks associated with abortion compared with the risks associated with its alternatives and (b) sources of variability in women's responses following abortion. This article reflects…

  11. Orientation toward Abortion: Guilt or Knowledge?

    ERIC Educational Resources Information Center

    Allgeier, A.R.; And Others

    1981-01-01

    Students (N=118) were classified as pro-choice, anti-abortion, or mixed on the basis of their responses to 10 fictitious case histories of women who requested abortion. Attitudinal differences are discussed in the context of the public controversy over abortion. (Author/CM)

  12. Do urban canyons influence street level grass pollen concentrations?

    NASA Astrophysics Data System (ADS)

    Peel, Robert George; Kennedy, Roy; Smith, Matt; Hertel, Ole

    2014-08-01

    In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found to be statistically significant only in London. The ratio of street/roof level concentrations was compared with temperature, relative humidity, wind speed and direction, and solar radiation. Results indicated that the concentration ratio responds to wind direction with respect to relative canyon orientation and local source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were not found to be significant in either location. These results suggest a tendency for monitoring station data to overestimate exposure in the canyon environment.

  13. Do urban canyons influence street level grass pollen concentrations?

    PubMed

    Peel, Robert George; Kennedy, Roy; Smith, Matt; Hertel, Ole

    2014-08-01

    In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found to be statistically significant only in London. The ratio of street/roof level concentrations was compared with temperature, relative humidity, wind speed and direction, and solar radiation. Results indicated that the concentration ratio responds to wind direction with respect to relative canyon orientation and local source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were not found to be significant in either location. These results suggest a tendency for monitoring station data to overestimate exposure in the canyon environment. PMID:24037300

  14. F-actin forms mobile and unwinding ring-shaped structures in germinating Arabidopsis pollen expressing Lifeact

    PubMed Central

    Vogler, Frank; Sprunck, Stefanie

    2015-01-01

    The flowering plant pollen tube is the fastest elongating plant cell and transports the sperm cells for double fertilization. The highly dynamic formation and reorganization of the actin cytoskeleton is essential for pollen germination and pollen tube growth. To drive pollen-specific expression of fluorescent marker proteins, commonly the strong Lat52 promoter is used. Here we show by quantitative fluorescent analysis that the gametophyte-specific ARO1 promoter from Arabidopsis drives an about 3.5 times weaker transgene expression than the Lat52 promoter. In one third of the pollen of F-actin-labeled ARO1p:tagRFP-T-Lifeact transgenic lines we observed mobile ring-shaped actin structures in pollen grains and pollen tubes. Pollen tube growth, transgene transmission and seed production were not affected by tagRFP-T-Lifeact expression. F-actin rings were able to integrate into emerging actin filaments and they may reflect a particular physiological state of the pollen or a readily available storage form provided for rapid actin network remodeling. PMID:26337326

  15. Diversity and function of maize pollen coat proteins: from biochemistry to proteomics

    PubMed Central

    Gong, Fangping; Wu, Xiaolin

    2015-01-01

    Maize (Zea mays L.) is globally cultivated as one of the most important grain crops. As a wind-pollinated species, maize produces a large quantity of pollen grains that heavier and larger compared to Arabidopsis. Maize is an important model plant in pollen biology of monocots. The pollen coat, the outermost layer of pollen, plays a vital role in pollen–stigma interactions and successful fertilization. Pollen coat proteins (PCPs), which confer species specificity, are required for pollen adhesion, recognition, hydration, and germination on the stigma. Thus, PCPs have attracted intensive research efforts in plant science for decades. However, only a few PCPs in maize have been characterized to date, whereas the functions of most maize PCPs remain unclear. In this review, we summarize the current knowledge of maize PCPs with regard to protein constituents, synthesis and transport, and functions by comparison with the model plant Arabidopsis thaliana and Brassica plants. An understanding of the comprehensive knowledge of maize PCPs will help to illuminate the mechanism by which PCPs are involved in pollen–stigma interactions in maize and other crop plants. PMID:25870606

  16. Preferential expression of an alpha-tubulin gene of Arabidopsis in pollen.

    PubMed Central

    Carpenter, J L; Ploense, S E; Snustad, D P; Silflow, C D

    1992-01-01

    The pool of tubulin protein in tissues of Arabidopsis is provided by the expression of multiple alpha-tubulin (TUA) and beta-tubulin genes. Whereas most tubulin genes are expressed in many tissues, previous evidence suggested that the TUA1 gene might be expressed primarily in pollen. We now report a detailed analysis of TUA1 expression during Arabidopsis development. In RNA from tissues of dissected flowers, TUA1 transcripts were detected only in stamens and mature pollen. Chimeric genes containing TUA1 5' flanking DNA fused to the beta-glucuronidase (GUS) coding region were used to create transgenic Arabidopsis plants. Plants containing a chimeric gene with 533 bp of 5' flanking sequence were analyzed by histochemical assay to localize GUS expression within the plant. The blue product of GUS enzyme activity accumulated very rapidly in postmitotic pollen grains. Much lower levels of GUS activity were detected in anthers with uninucleate pollen grains, in flower receptacles, and in a few vegetative tissues. Analysis of 5' deletions of the TUA1 promoter suggested that 97 bp of 5' flanking DNA is sufficient to drive GUS expression in pollen and young anthers, whereas at least 380 bp is required to detect GUS expression in the receptacle. Examination of the TUA1 promoter sequence revealed several motifs that are repeated within the TUA1 promoter and are similar to sequences in other pollen-specific promoters. PMID:1498610

  17. 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

  18. Identifying the pollen of an extinct spruce species in the Late Quaternary sediments of the Tunica Hills region, south-eastern United States

    USGS Publications Warehouse

    Luke Mander; Jacklyn Rodriguez; Pietra G. Mueller; Jackson, Stephen T.; Surangi W. Punyasena

    2014-01-01

    Late Quaternary fluvial deposits in the Tunica Hills region of Louisiana and Mississippi are rich in spruce macrofossils of the extinct species Picea critchfieldii, the one recognized plant extinction of the Late Quaternary. However, the morphology of P. critchfieldii pollen is unknown, presenting a barrier to the interpretation of pollen spectra from the last glacial of North America. To address this issue, we undertook a morphometric study of Picea pollen from Tunica Hills. Morphometric data, together with qualitative observations of pollen morphology using Apotome fluorescence microscopy, indicate that Picea pollen from Tunica Hills is morphologically distinct from the pollen of P. glauca, P. mariana and P. rubens. Measurements of grain length, corpus width and corpus height indicate that Picea pollen from Tunica Hills is larger than the pollen of P. mariana and P. rubens, and is slightly larger than P. glauca pollen. We argue that the morphologically distinctive Tunica Hills Picea pollen was probably produced by the extinct spruce species P. critchfieldii. These morphological differences could be used to identify P. critchfieldii in existing and newly collected pollen records, which would refine its paleoecologic and biogeographic history and clarify the nature and timing of its extinction in the Late Quaternary.

  19. 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

  20. The long distance transport (LDT) of Ambrosia pollen from the Pannonian Plain to Scandinavia

    NASA Astrophysics Data System (ADS)

    Šikoparija, B..; Skjøth, C. A.; Alm Kübler, K.; Dahl, A.; Radišić, P.; Sommer, J.; Grewling, Ł.; Smith, M.

    2012-04-01

    Ragweed (Ambrosia spp.) pollen grains are important aeroallergens that cause seasonal allergic rhinitis and asthma to sensitive individuals. This study describes the conditions required for the LDT of ragweed pollen from the Pannonian Plain (PP) to Sweden on the 27- 28 August 2011, using a combination of daily and bi-hourly pollen count data, the overall synoptic weather situation, 3D analysis of the regional scale orography using Digital Elevation Models, surface meteorological data, satellite observations, and air mas trajectories calculated using the HYSPLIT model. During the episode, high pressure (1024-1028 hPa) situated over European Russia and the Black Sea to the east and deep low pressure (~990 hPa) over the British Isles in the northwest resulted in a general southeast-northwest movement of air, and the occurrence of the jet-effect Kosava wind in the PP. This dry and gusty wind caused ragweed pollen release on the PP and pollen to be transported to the northwest. A foehn wind that governs air movement down leeward slopes into the PP was also active. The 24 and 25 August 2011 were very hot and caused large amounts of ragweed pollen to be released and taken high up in the atmosphere through convection. Such conditions also resulted in high Planetary Boundary Layers over the entire area, conditions that facilitated the transport of pollen over areas of low elevation on the Western Carpathians (i.e. the Moravian Gate or Low Baskid passes) northward into Poland and beyond.

  1. 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

  2. Classification of grass pollen through the quantitative analysis of surface ornamentation and texture.

    PubMed

    Mander, Luke; Li, Mao; Mio, Washington; Fowlkes, Charless C; Punyasena, Surangi W

    2013-11-01

    Taxonomic identification of pollen and spores uses inherently qualitative descriptions of morphology. Consequently, identifications are restricted to categories that can be reliably classified by multiple analysts, resulting in the coarse taxonomic resolution of the pollen and spore record. Grass pollen represents an archetypal example; it is not routinely identified below family level. To address this issue, we developed quantitative morphometric methods to characterize surface ornamentation and classify grass pollen grains. This produces a means of quantifying morphological features that are traditionally described qualitatively. We used scanning electron microscopy to image 240 specimens of pollen from 12 species within the grass family (Poaceae). We classified these species by developing algorithmic features that quantify the size and density of sculptural elements on the pollen surface, and measure the complexity of the ornamentation they form. These features yielded a classification accuracy of 77.5%. In comparison, a texture descriptor based on modelling the statistical distribution of brightness values in image patches yielded a classification accuracy of 85.8%, and seven human subjects achieved accuracies between 68.33 and 81.67%. The algorithmic features we developed directly relate to biologically meaningful features of grass pollen morphology, and could facilitate direct interpretation of unsupervised classification results from fossil material. PMID:24048158

  3. Classification of grass pollen through the quantitative analysis of surface ornamentation and texture

    PubMed Central

    Mander, Luke; Li, Mao; Mio, Washington; Fowlkes, Charless C.; Punyasena, Surangi W.

    2013-01-01

    Taxonomic identification of pollen and spores uses inherently qualitative descriptions of morphology. Consequently, identifications are restricted to categories that can be reliably classified by multiple analysts, resulting in the coarse taxonomic resolution of the pollen and spore record. Grass pollen represents an archetypal example; it is not routinely identified below family level. To address this issue, we developed quantitative morphometric methods to characterize surface ornamentation and classify grass pollen grains. This produces a means of quantifying morphological features that are traditionally described qualitatively. We used scanning electron microscopy to image 240 specimens of pollen from 12 species within the grass family (Poaceae). We classified these species by developing algorithmic features that quantify the size and density of sculptural elements on the pollen surface, and measure the complexity of the ornamentation they form. These features yielded a classification accuracy of 77.5%. In comparison, a texture descriptor based on modelling the statistical distribution of brightness values in image patches yielded a classification accuracy of 85.8%, and seven human subjects achieved accuracies between 68.33 and 81.67%. The algorithmic features we developed directly relate to biologically meaningful features of grass pollen morphology, and could facilitate direct interpretation of unsupervised classification results from fossil material. PMID:24048158

  4. [Is a sociology of abortion possible?].

    PubMed

    Isambert, F A

    1982-01-01

    Abortion is a thorny problem whose study is problematic because it is a source of social and juridical discord, of moral incertitude, of medical and psychiatric confusion, and of personal anguish. The question arises of whether a single perspective can be found which allows comprehension of the entire phenomenon. This work uses published sources to examine the abortion debate, beginning with the varying views of abortion expressed in the struggles to liberalize abortion legislation in France, Europe, and the US. 4 particular views of abortion were identified in the Paris press; the traditional religious view, which condemns abortion because the fetus is regarded as fully human from conception; the view of abortion as a means of fertility regulation; the view of abortion as a cause of public health problems that could be alleviated through legalization and medical control; and the view that abortion allows women to control their own bodies. The law is obliged to reconcile these diverse positions. Abortion legislation in different countries ranges along a continuum from severe to lenient, but regional variations are also evident. Abortion trials in the US and France shortly before liberalization of the laws of either country showed striking similarities but also notable differences due largely to dissimilarities in the social structures of the 2 countries. The relations between the individual and the state, morality, and the law, as reflected in the abortion debate, rested on inverse bases in the 2 countries. The typically American doctrine of privacy occupied a prominent place in the American legislation, while the French was more concerned with the humanitarian goal of reducing health damage from illegal abortions. Tension and ambiguity nevertheless unavoidably characterize the abortion regulations in the 2 countries. Abortion as an institution is a controlled and practical compromise between 2 poles, those giving primacy to individual interests, as in the US, and

  5. RU-486: the "abortion pill".

    PubMed

    Herranz, G

    1991-05-23

    A report sent by the Vatican to bishops' conferences throughout the world calls RU-486, the so-called abortion pill currently available in France, "a new, serious threat to human life." The report was developed at the Vatican's request by Gonzalo Herranz, a Spanish bioethicist. A cover letter to bishops' conferences from Cardinal Alfonso Lopez Trujillo, president of the Pontifical Council for the Family, suggested that the report be used "to resist the introduction of the abortion pill RU-486 into your country." Related to TU-486 and to new terminology some use to characterize its non-surgical approach to abortion is an intention "to amoralize and thereby place the transmission of human life into an ethically neutral terrain and reduce it to pure biology," says the report. The report discusses possible future uses of RU-486 as a contraceptive, stating: "Women would no longer have to worry themselves about whether they have conceived or not. Each month they would proceed to clean out their uterus chemically." The report refers to RU-486 as "a technical step forward in an area that did not need it." It says, "The abortion pill favors a woman's privacy and secret, but it condemns her to solitude." The English text from the Vatican follows. PMID:16145821

  6. Self-Compatibility of Two Apricot Selections Is Associated with Two Pollen-Part Mutations of Different Nature1[W

    PubMed Central

    Vilanova, Santiago; Badenes, María Luisa; Burgos, Lorenzo; Martínez-Calvo, José; Llácer, Gerardo; Romero, Carlos

    2006-01-01

    Loss of pollen-S function in Prunus self-compatible mutants has recently been associated with deletions or insertions in S-haplotype-specific F-box (SFB) genes. We have studied two self-compatible cultivars of apricot (Prunus armeniaca), Currot (SCSC) and Canino (S2SC), sharing the naturally occurring self-compatible (SC)-haplotype. Sequence analysis showed that whereas the SC-RNase is unaltered, a 358-bp insertion is found in the SFBC gene, resulting in the expression of a truncated protein. The alteration of this gene is associated with self-incompatibility (SI) breakdown, supporting previous evidence that points to SFB being the pollen-S gene of the Prunus SI S-locus. On the other hand, PCR analysis of progenies derived from Canino showed that pollen grains carrying the S2-haplotype were also able to overcome the incompatibility barrier. However, alterations in the SFB2 gene or evidence of pollen-S duplications were not detected. A new class of F-box genes encoding a previously uncharacterized protein with high sequence similarity (approximately 62%) to Prunus SFB proteins was identified in this work, but the available data rules them out of producing S-heteroallelic pollen and thus the cause of the pollen-part mutation. These results suggest that cv Canino has an additional mutation, not linked to the S-locus, which causes a loss of pollen-S activity when present in pollen. As a whole, these findings support the proposal that the S-locus products besides other S-locus independent factors are required for gametophytic SI in Prunus. PMID:16920873

  7. RNA-Seq of Arabidopsis Pollen Uncovers Novel Transcription and Alternative Splicing1[C][W][OA

    PubMed Central

    Loraine, Ann E.; McCormick, Sheila; Estrada, April; Patel, Ketan; Qin, Peng

    2013-01-01

    Pollen grains of Arabidopsis (Arabidopsis thaliana) contain two haploid sperm cells enclosed in a haploid vegetative cell. Upon germination, the vegetative cell extrudes a pollen tube that carries the sperm to an ovule for fertilization. Knowing the identity, relative abundance, and splicing patterns of pollen transcripts will improve our understanding of pollen and allow investigation of tissue-specific splicing in plants. Most Arabidopsis pollen transcriptome studies have used the ATH1 microarray, which does not assay splice variants and lacks specific probe sets for many genes. To investigate the pollen transcriptome, we performed high-throughput sequencing (RNA-Seq) of Arabidopsis pollen and seedlings for comparison. Gene expression was more diverse in seedling, and genes involved in cell wall biogenesis were highly expressed in pollen. RNA-Seq detected at least 4,172 protein-coding genes expressed in pollen, including 289 assayed only by nonspecific probe sets. Additional exons and previously unannotated 5′ and 3′ untranslated regions for pollen-expressed genes were revealed. We detected regions in the genome not previously annotated as expressed; 14 were tested and 12 were confirmed by polymerase chain reaction. Gapped read alignments revealed 1,908 high-confidence new splicing events supported by 10 or more spliced read alignments. Alternative splicing patterns in pollen and seedling were highly correlated. For most alternatively spliced genes, the ratio of variants in pollen and seedling was similar, except for some encoding proteins involved in RNA splicing. This study highlights the robustness of splicing patterns in plants and the importance of ongoing annotation and visualization of RNA-Seq data using interactive tools such as Integrated Genome Browser. PMID:23590974

  8. Ontogeny of the barley plant as related to mutation expression and detection of pollen mutations

    SciTech Connect

    Hodgdon, A.L.; Marcus, A.H.; Arenaz, P.; Rosichan, J.L.; Bogyo, T.P.; Nilan, R.A.

    1980-05-29

    Clustering of mutant pollen grains in a population of normal pollen due to premeiotic mutational events complicates translating mutation frequencies into rates. Embryo ontogeny in barley will be described and used to illustrate the formation of such mutant clusters. The nature of the statistics for mutation frequency will be described from a study of the reversion frequencies of various waxy mutants in barley. Computer analysis by a jackknife method of the reversion frequencies of a waxy mutant treated with the mutagen sodium azide showed a significantly higher reversion frequency than untreated material. Problems of the computer analysis suggest a better experimental design for pollen mutation experiments. Preliminary work on computer modeling for pollen development and mutation will be described.

  9. Ontogeny of the barley plant as related to mutation expression and detection of pollen mutations

    SciTech Connect

    Hodgdon, A.L.; Marcus, A.H.; Arenaz, P.; Rosichan, J.L.; Bogyo, T.P.; Nilan, R.A.

    1981-01-01

    Clustering of mutant pollen grains in a population of normal pollen due to premeiotic mutational events complicates translating mutation frequencies into rates. Embryo ontogeny in barley will be described and used to illustrate the formation of such mutant clusters. The nature of the statistics for mutation frequency will be described from a study of the reversion frequencies of various waxy mutants in barley. Computer analysis by a ''jackknife'' method of the reversion of a waxy mutant treated with the mutagen sodium azide showed a significantly higher reversion frequency than untreated material. Problems of the computer analysis suggest a better experimental design for pollen mutation experiments. Preliminary work on computer modeling for pollen development and mutation will be described.

  10. 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

  11. Seventeen years of legalized abortion in Singapore.

    PubMed

    Saw, S

    1988-06-01

    "In this paper we first discuss the two-stage process of legalizing induced abortion in Singapore, the initial legalization to make it available on a restrictive basis in 1970 and the complete liberalization to make it available on demand from 1975 onwards. The incidence of abortions registered in the last seventeen years and the major characteristics of aborters are analysed. The impact of abortion on the rapid decline of fertility to below-replacement level is highlighted, and the need to reduce abortion by amending the more liberal aspects of the law are considered at the end of the paper." PMID:12341971

  12. Unintended pregnancy and abortion in Uganda.

    PubMed

    Hussain, Rubina

    2013-01-01

    Unintended pregnancy is common in Uganda, leading to high levels of unplanned births, unsafe abortions, and maternal injury and death. Because most pregnancies that end in abortion are unwanted, nearly all ill health and mortality resulting from unsafe abortion is preventable. This report summarizes evidence on the context and consequences of unintended pregnancy and unsafe abortion in Uganda, points out gaps in knowledge, and highlights steps that can be taken to reduce levels of unintended pregnancy and unsafe abortion, and, in turn, the high level of maternal mortality. PMID:23550324

  13. 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

  14. Family planning is reducing abortions.

    PubMed

    Clinton, H R

    1997-01-01

    This news brief presents the US President's wife's statement on the association between use of family planning and a decline in abortions worldwide. Hillary Rodham Clinton attended the Sixth Conference of Wives of Heads of State and Government of the Americas held in La Paz, Bolivia. The conference was suitably located in Bolivia, a country with the highest rates of maternal mortality in South America. Bolivia has responded by launching a national family planning campaign coordinated between government, nongovernmental, and medical organizations. Half of Bolivian women experience pregnancy and childbirth without the support of trained medical staff. Mortality from abortion complications account for about half of all maternal deaths in Bolivia. Voluntary family planning workers teach women about the benefits of child spacing, breast feeding, nutrition, prenatal and postpartum care, and safe deliveries. Bolivia has succeeded in increasing its contraceptive use rates and decreasing the number of safe and unsafe abortions. Bolivia's program effort was supported by USAID. USAID provided technical assistance and funds for the establishment of a network of primary health care clinics. Mrs. Clinton visited one such clinic in a poor neighborhood in La Paz, which in its first six months of operation provided 2200 consultations, delivered 200 babies, registered 700 new family planning users, and immunized 2500 children. Clinics such as this one will be affected by the US Congress's harsh cuts in aid, which reduce funding by 35% and delay program funding by 9 months. These US government cuts in foreign aid are expected to result in an additional 1.6 million abortions, over 8000 maternal deaths, and 134,000 infant deaths in developing countries. An investment in population assistance represents a sensible, cost-effective, and long-term strategy for improving women's health, strengthening families, and reducing abortion. PMID:12293000

  15. The Novel Plant Protein INAPERTURATE POLLEN1 Marks Distinct Cellular Domains and Controls Formation of Apertures in the Arabidopsis Pollen Exine[C][W

    PubMed Central

    Dobritsa, Anna A.; Coerper, Daniel

    2012-01-01

    Pollen grains protect the sperm cells inside them with the help of the unique cell wall, the exine, which exhibits enormous morphological variation across plant taxa, assembling into intricate and diverse species-specific patterns. How this complex extracellular structure is faithfully deposited at precise sites and acquires precise shape within a species is not understood. Here, we describe the isolation and characterization of the novel Arabidopsis thaliana gene INAPERTURATE POLLEN1 (INP1), which is specifically involved in formation of the pollen surface apertures, which arise by restriction of exine deposition at specific sites. Loss of INP1 leads to the loss of all three apertures in Arabidopsis pollen, and INP1 protein exhibits a unique tripartite localization in developing pollen, indicative of its direct involvement in specification of aperture positions. We also show that aperture length appears to be sensitive to INP1 dosage and INP1 misexpression can affect global exine patterning. Phenotypes of some inp1 mutants indicate that Arabidopsis apertures are initiated at three nonrandom positions around the pollen equator. The identification of INP1 opens up new avenues for studies of how formation of distinct cellular domains results in the production of different extracellular morphologies. PMID:23136373

  16. Post-abortion syndrome: creating an affliction.

    PubMed

    Dadlez, E M; Andrews, William L

    2010-11-01

    The contention that abortion harms women constitutes a new strategy employed by the pro-life movement to supplement arguments about fetal rights. David C. Reardon is a prominent promoter of this strategy. Post-abortion syndrome purports to establish that abortion psychologically harms women and, indeed, can harm persons associated with women who have abortions. Thus, harms that abortion is alleged to produce are multiplied. Claims of repression are employed to complicate efforts to disprove the existence of psychological harm and causal antecedents of trauma are only selectively investigated. We argue that there is no such thing as post-abortion syndrome and that the psychological harms Reardon and others claim abortion inflicts on women can usually be ascribed to different causes. We question the evidence accumulated by Reardon and his analysis of data accumulated by others. Most importantly, we question whether the conclusions Reardon has drawn follow from the evidence he cites. PMID:19594725

  17. Abortion returns to haunt US presidential campaign.

    PubMed

    Greenberg, D S

    2000-04-01

    The abortion issue has infested national politics since 1973, now it returns to haunt the US presidential election politics. However, rather than serving as a customary rallying cause for Republicans, it is now a millstone around the neck of their candidate, Governor George Bush, who seeks a broad ideological span of voters to win his candidacy. Bush expressed strong anti-abortion sentiments to attract the die-hard right-to-life vote in the hard-fought primary campaign. For many years, the anti-abortion language in the US remains strident, however, it is clear that most voters support, or at least tolerate, the availability of abortion services. In his presidential campaign, Bush shied away from endorsing a constitutional amendment to ban abortion, and declared his opposition to any exceptions to an abortion ban. He is now on the record with numerous anti-abortion declarations, and holds endorsements from the pro-life camp. PMID:10791389

  18. Abortion counseling: to benefit maternal health.

    PubMed

    Steinberg, T N

    1989-01-01

    This Note examines how both the law and the health care profession neglect women's needs for abortion counseling before, during and after an abortion. Part I analyzes the health care profession's view of counseling, the psychological effects of abortion and how counseling both positively and negatively influences those effects. Part II reviews Supreme Court cases and state law regarding abortion counseling, critizing both the Court's narrow view of counseling and the states' failure to use the legislative process to create laws which benefit maternal health. Part III recommends an expanded role for abortion counseling, in which the counselor can provide emotional support from before the day of an abortion until a woman emotionally recovers from an abortion. This expanded role would be state-mandated, but would remain within constitutional boundaries by providing flexibility for counselors to give individual treatment while respecting a woman's privacy. PMID:2699161

  19. [Induced abortion--a historical outline].

    PubMed

    Glenc, F

    1974-11-11

    An historical review of the use of induced abortion is presented, beginning with early eras. The Chinese were the 1st to record the practice of induced abortion, with this operation being administered to royal concubines recorded at 500-515 B.C. Induced abortion was not used in ancient Greece, either for criminal or ethical reason. However, the ancient Greeks did utilize compulsory abortion for serious economic indications, as a means of controlling natural growth. Greek medical, gyneoclogigcal instruments for adminsitering abortions were described by Hippocrates. The Greek moral attitudes on abortion were largely adopted by the Romans, which were later altered by the appearance of Christianity and new ethical ideas. These ideas dominated European attitudes, along with the Church of Rome, limiting induced abortion to cases where the life of the mother was threatened. This attitude has existed until the present century, when these moral ideas are being challanged seriously for the 1st time in modern history. PMID:4610534

  20. Absence of toxicity of Bacillus thuringiensis pollen to black swallowtails under field conditions.

    PubMed

    Wraight, C L; Zangerl, A R; Carroll, M J; Berenbaum, M R

    2000-07-01

    A single laboratory study on monarch butterflies has prompted widespread concern that corn pollen, engineered to express Bacillus thuringiensis (Bt) endotoxin, might travel beyond corn fields and cause mortality in nontarget lepidopterans. Among the lepidopterans at high potential risk from this technology is the black swallowtail butterfly, Papilio polyxenes, whose host plants in the midwestern U. S. are located principally in narrow strips between roads and crop fields. A field study was performed to assess whether mortality of early instar black swallowtails was associated either with proximity to a field of Bt corn or by levels of Bt pollen deposition on host plants. Potted host plants were infested with first instar black swallowtails and placed at intervals from the edge of a field of Bt corn (Pioneer 34R07 containing Monsanto event 810) at the beginning of anthesis. We confirmed by ELISA that pollen from these plants contained Cry1Ab endotoxin (2.125 +/- 0.289 ng/g). Although many of the larvae died during the 7 days that the experiments were run, there was no relationship between mortality and proximity to the field or pollen deposition on host plants. Moreover, pollen from these same plants failed to cause mortality in the laboratory at the highest pollen dose tested (10,000 grains/cm(2)), a level that far exceeded the highest pollen density observed in the field (200 grains/cm(2)). We conclude that Bt pollen of the variety tested is unlikely to affect wild populations of black swallowtails. Thus, our results suggest that at least some potential nontarget effects of the use of transgenic plants may be manageable. PMID:10840067

  1. Serum lipoperoxides in induced and spontaneous abortions.

    PubMed

    Sane, A S; Chokshi, S A; Mishra, V V; Barad, D P; Shah, V C; Nagpal, S

    1991-01-01

    Abortion, primarily as a measure of population control, certainly continues to be an emotional, frustrating and stressful event. In continuation of our work on stressful situations in the female life span and biochemical parameters, serum lipid peroxide levels in terms of malondialdehyde (nmol/ml) have been determined in females undergoing abortion [suction curettage (n = 30), Emcredil-induced abortion (n = 30) and spontaneous abortion (n = 40)] and were compared with appropriate gestational controls. Irrespective of the type of abortion, the serum lipid peroxide levels before abortion [mean malondialdehyde concentrations (nmol/ml): suction curettage 2.67, Emcredil-induced abortion 3.22, and spontaneous abortion 3.49] were found to be significantly elevated in comparison with those after abortion (suction curettage 1.91, Emcredil 1.97 and spontaneous abortion 1.95), indicating a maximum at peak time of stress and a minimum at the end of stress. The levels of serum lipid peroxide encountered before abortion were found to be significantly elevated in case of Emcredil-induced abortion and spontaneous abortion when compared with controls (second trimester mean levels 1.82 and first trimester 2.4) whereas the levels before suction curettage were found to be nonsignificant in comparison with controls, indicating a lesser degree of stress. It is felt that monitoring of serum lipid peroxide levels in serum and tissues (placenta), backed by scavenging enzyme superoxide dismutase, can be more helpful for corroborating safety and the risk of free radical toxicity in pregnancy and abortion. PMID:2071057

  2. Unsafe abortion and postabortion care - an overview.

    PubMed

    Rasch, Vibeke

    2011-07-01

    Forty per cent of the world's women are living in countries with restrictive abortion laws, which prohibit abortion or only allow abortion to protect a woman's life or her physical or mental health. In countries where abortion is restricted, women have to resort to clandestine interventions to have an unwanted pregnancy terminated. As a consequence, high rates of unsafe abortion are seen, such as in Sub-Saharan Africa where unsafe abortion occurs at rates of 18-39 per 1 000 women. The circumstances under which women obtain unsafe abortion vary and depend on traditional methods known and types of providers present. Health professionals are prone to use instrumental procedures to induce the abortion, whereas traditional providers often make a brew of herbs to be drunk in one or more doses. In countries with restrictive abortion laws, high rates of maternal death must be expected, and globally an estimated 66 500 women die every year as a result of unsafe abortions. In addition, a far larger number of women experience short- and long-term health consequences. To address the harmful health consequences of unsafe abortion, a postabortion care model has been developed and implemented with success in many countries where women do not have legal access to abortion. Postabortion care focuses on treatment of incomplete abortion and provision of postabortion contraceptive services. To enhance women's access to postabortion care, focus is increasingly being placed on upgrading midlevel providers to provide emergency treatment as well as implementing misoprostol as a treatment strategy for complications after unsafe abortion. PMID:21542813

  3. 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.

  4. 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

  5. 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

  6. [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

  7. 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

  8. The pollen complex from postglacial sediments of the Laptev Sea as a bioindicator

    NASA Astrophysics Data System (ADS)

    Naidina, O. D.

    2014-05-01

    The first results of comparison of palynological analysis (pollen of terrestrial plants), SEM analysis of pollen morphology, and radiocarbon age dating (AMS14C) of sediments of the eastern shelf of the Laptev Sea show that the diverse taxonomic composition of pollen spectra provides an integrated idea of the vegetation and climate of the region over 11.2 calendar kiloyears. It is found that phases of the tree and shrub vegetation development (maxima of pollen of Betula sect. Nanae and Pinus s/g Haploxylon) correspond to the warm epochs in the Holocene. It is obvious that birch phytocoenoses first settled in the southern tundra subzone with increasing temperature, and then coniferous communities of forest tundra. An occurrence of pollen of shrubby birches (Nanae) suggests compliance of permafrost landscapes with cold climate conditions, i.e., with an annual average temperature of -2°C and amount of precipitation of less than 500 mm. Owing to a progressive increase in summer temperatures, dwarf cedar and pine communities advanced toward the seashore. The SEM analysis results show that a significant proportion of regional coniferous pollen belongs to representatives of Pinus pumila (Pall.) and P. sylvestris L. In addition, the SEM study of the exine of Pinus sylvestris L. and P. pumila (Pall.) Regel pollen grains confirmed polymorphism in coniferous pollen. According to the inverse relationship between climate and vegetation, frequent climate fluctuations that are typical of progressive and differential postglacial transgression were revealed. An increase in arboreal pollen transfer onto the shelf later than 9.1 cal. ka coincides with the time of forest boundary migration to the north due to the warming of the Earth's climate. At that time, the tundra vegetation was replaced by forest-tundra vegetation, the maximum stage of sea transgression began, and there appeared a trend of increasing temperature and moisture.

  9. The involvement of nitric oxide in ultraviolet-B-inhibited pollen germination and tube growth of Paulownia tomentosa in vitro.

    PubMed

    He, Jun-Min; Bai, Xiao-Ling; Wang, Rui-Bin; Cao, Bing; She, Xiao-Ping

    2007-10-01

    The role of nitric oxide (NO) in the ultraviolet-B radiation (UV-B)-induced reduction of in vitro pollen germination and tube growth of Paulownia tomentosa Steud. was studied. Results showed that exposure of the pollen to 0.4 and 0.8 W m(-2) UV-B radiation for 2 h resulted in not only the reduction of pollen germination and tube growth but also the enhancement of NO synthase (NOS, EC 1.14.13.39) activity and NO production in pollen grain and tube. Also, exogenous NO donors sodium nitroprusside and S-nitrosoglutathione inhibited both pollen germination and tube growth in a dose-dependence manner. NOS inhibitor N(G)-nitro-l-Arg-methyl eater (l-NAME) and NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) not only largely prevented the NO generation but also partly reversed the UV-B-inhibited pollen germination and tube growth. These results indicate that UV-B radiation inhibits pollen germination and tube growth partly via promoting NO production in pollen grain and tube by a NOS-like enzyme. Additionally, a guanylyl cyclase inhibitor 6-anilino-5,8-quinolinequinone (LY-83583) prevented both the UV-B- and NO donors-inhibited pollen germination and tube growth, suggesting that the NO function is mediated by cyclic guanosine 5'-monophosphate. However, the effects of c-PTIO, l-NAME and LY-83583 on the UV-B-inhibited pollen germination and tube growth were only partial, suggesting that there are NO-independent pathways in UV-B signal networks. PMID:18251898

  10. 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

  11. 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

  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.

    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

  13. 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

  14. AMS radiocarbon dating of pollen concentrates in a karstic lake system

    NASA Astrophysics Data System (ADS)

    Fletcher, William; Zielhofer, Christoph; Mischke, Steffen; Campbell, Jennifer; Bryant, Charlotte; Fink, David; Xu, Xiaomei

    2016-04-01

    In lake sediments where terrestrial macrofossils are rare or absent, AMS radiocarbon dating of pollen concentrates represents an important alternative solution for developing a robust and high resolution chronology suitable for Bayesian modelling of age-depth relationships. Here we report an application of the dense media separation approach (Vandergoes and Prior, Radiocarbon 45:479-492, 2003) to Holocene lake sediments from karstic Lake Sidi Ali, Morocco (33° 03'N, 05° 00'W; 2,080 m a.s.l.). Paired dates on terrestrial (macrofossil) and aquatic (ostracod) samples, and dating of bulk sediment surface material at the site indicate varying reservoir effects of up to 900 yr and highlight the need to date terrestrial carbon sources. Dating of pollen concentrates is a viable approach at Lake Sidi Ali, as pollen concentrations are high (~200,000 grains/cc), and pollen assemblages typically contain only minor percentages (<1%) of aquatic pollen. Following laboratory trials, 23 pollen concentrates alongside laboratory standards (anthracite, IAEA C5 wood) were prepared and dated following the heavy liquid (sodium polytungstate, SPT) density separation protocol. A series of SPT solutions of progressively decreasing density (1.9-1.15 s.g.) were used to divide the samples into several fractions. The pollen purity of these fractions was evaluated by microscopic analysis of smear slides, and the richest fraction(s) were selected for dating. Sieving at 10 μm and at 50/125 μm (depending on the size of predominant pollen grains) was used to further concentrate the pollen grains, and the samples were freeze dried to determine the dry weight of material. The results show that the highest purity of pollen is sample dependent and may typically be achieved in the fractions precipitating at 1.4-1.2 s.g. With sieving, terrestrial pollen purity of ~50-80% can be achieved, offering a considerable improvement in terms of terrestrial carbon content over bulk sediment. These values reflect

  15. 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...

  16. 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

  17. Departure phase aborts for manned Mars missions

    NASA Astrophysics Data System (ADS)

    Dissel, Adam F.

    NASA goals are set on resumption of human activity on the Moon and extending manned missions to Mars. Abort options are key elements of any system designed to safeguard human lives and stated requirements stipulate the provision of an abort capability throughout the mission. The present investigation will focus on the formulation and analysis of possible abort modes during the Earth departure phase of manned Mars interplanetary transfers. Though of short duration, the departure phase encompasses a mission timeline where failures have frequently become manifest in historical manned spacecraft necessitating the inclusion of a departure phase abort capability. Investigated abort modes included aborts to atmospheric entry, and to Earth or Moon orbit. Considered interplanetary trajectory types included conjunction, opposition, and free-return trajectory classes. All abort modes were analyzed for aborts initiated at multiple points along each of these possible departure trajectories across all launch opportunities of the fifteen-year Earth-Mars inertial period. The consistently low departure velocities of the conjunction trajectories facilitated the greatest abort capability. An analysis of Mars transportation architectures was performed to determine the amount of available delta V inherent in each candidate architecture for executing departure aborts. Results indicate that a delta V of at least 4 km/s is required to achieve a continuous departure phase entry abort capability with abort flights less than three weeks duration for all transfer opportunity years. Less demanding transfer years have a corresponding increase in capability. The Earth orbit abort mode does not become widely achievable until more than 6 km/s delta V is provided; a capacity not manifest in any considered architecture. Optimization of the Moon abort mode resulted in slight departure date shifts to achieve improved lunar alignments. The Moon abort mode is only widely achievable for conjunction

  18. Zm908p11, encoded by a short open reading frame (sORF) gene, functions in pollen tube growth as a profilin ligand in maize

    PubMed Central

    Dong, Xue; Wang, Dongxue; Liu, Peng; Li, Chengxia; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2013-01-01

    Double fertilization of flowering plants depends on the targeted transportation of sperm to the embryo sac by the pollen tube. Currently, little is known about the underlying molecular mechanisms that regulate pollen germination and pollen tube growth in maize (Zea mays). Here, a maize pollen-predominant gene Zm908, with several putative short open reading frames (sORFs), was isolated and characterized. The longest ORF of Zm908 encodes a small protein of 97 amino acids. This was designated as Zm908p11 and is distributed throughout the maize pollen tube. Western blot detected the small peptide in mature pollen. Quantitative reverse transcription–PCR and northern blot analysis revealed that Zm908p11 was expressed predominantly in mature pollen grains. Ectopic overexpression of full-length Zm908 and Zm908p11 in tobacco resulted in defective pollen, while transgenic tobacco plants with a site-specific mutation or a frameshift mutation of Zm908p11 showed normal pollen development. Overexpression of Zm908p11 in maize decreased pollen germination efficiency. Maize pollen cDNA library screening and protein–protein interaction assays demonstrated that Zm908p11 interacts with maize profilin 1 (ZmPRO1). A microarray analysis identified 273 up-regulated and 203 down-regulated genes in the overexpressing transgenic Zm908p11 pollen. Taken together, these results indicate that Zm908 functions as Zm908p11, and binds to profilins as a novel ligand, with a required role during pollen tube growth in maize. Accordingly, a model is proposed for the role of Zm908p11 during pollen tube growth in maize. PMID:23676884

  19. Abort Options for Potential Mars Missions

    NASA Technical Reports Server (NTRS)

    Tartabini, P. V.; Striepe, S. A.; Powell, R. W.

    1994-01-01

    Mars trajectory design options were examined that would accommodate a premature termination of a nominal manned opposition class mission for opportunities between 2010 and 2025. A successful abort must provide a safe return to Earth in the shortest possible time consistent with mission constraints. In this study, aborts that provided a minimum increase in the initial vehicle mass in low Earth orbit (IMLEO) were identified by locating direct transfer nominal missions and nominal missions including an outbound or inbound Venus swing-by that minimized IMLEO. The ease with which these missions could be aborted while meeting propulsion and time constraints was investigated by examining free return (unpowered) and powered aborts. Further reductions in trip time were made to some aborts by the addition or removal of an inbound Venus swing-by. The results show that, although few free return aborts met the specified constraints, 85% of each nominal mission could be aborted as a powered abort without an increase in propellant. Also, in many cases, the addition or removal of a Venus swing-by increased the number of abort opportunities or decreased the total trip time during an abort.

  20. Is Induced Abortion Really Declining in Armenia?

    PubMed

    Jilozian, Ann; Agadjanian, Victor

    2016-06-01

    As in other post-Soviet settings, induced abortion has been widely used in Armenia. However, recent national survey data point to a substantial drop in abortion rates with no commensurate increase in modern contraceptive prevalence and no change in fertility levels. We use data from in-depth interviews with women of reproductive age and health providers in rural Armenia to explore possible underreporting of both contraceptive use and abortion. While we find no evidence that women understate their use of modern contraception, the analysis suggests that induced abortion might indeed be underreported. The potential for underreporting is particularly high for sex-selective abortions, for which there is growing public backlash, and medical abortion, a practice that is typically self-administered outside any professional supervision. Possible underreporting of induced abortion calls for refinement of both abortion registration and relevant survey instruments. Better measurement of abortion dynamics is necessary for successful promotion of effective modern contraceptive methods and reduction of unsafe abortion practices. PMID:27285426

  1. Induced abortion: a world review, 1990.

    PubMed

    Henshaw, S K

    1990-01-01

    The worldwide trend toward liberalization of abortion laws has continued in the last four years with changes in Canada, Czechoslovakia, Greece, Hungary, Romania, the Soviet Union and Vietnam. Forty percent of the world's population now lives in countries where induced abortion is permitted on request, and 25 percent lives where it is allowed only if the woman's life is in danger. In 1987, an estimated 26 to 31 million legal abortions and 10 to 22 million clandestine abortions were performed worldwide. Legal abortion rates ranged from a high of at least 112 abortions per 1,000 women of reproductive age in the Soviet Union to a low of five per 1,000 in the Netherlands. In recent years, abortion rates have been increasing in Czechoslovakia, England and Wales, New Zealand and Sweden and declining in China, France, Iceland, Italy, Japan and the Netherlands. In most Western European and English-speaking countries, about half of abortions are obtained by young, unmarried women seeking to delay a first birth, while in Eastern Europe and the developing countries, abortion is most common among married women with two or more children. Mortality from legal abortion averages 0.6 deaths per 100,000 procedures in developed countries with data. Abortion services are increasingly being provided outside of hospitals, and for those performed in hospitals, overnight stays are becoming less common. National health insurance covers abortions needed to preserve the health of a pregnant woman in all developed countries except the United States, where Medicaid and federal insurance programs do not cover abortion unless the woman's life is in danger. PMID:2347411

  2. The Incidence of Abortion in Nigeria

    PubMed Central

    Bankole, Akinrinola; Adewole, Isaac F.; Hussain, Rubina; Awolude, Olutosin; Singh, Susheela; Akinyemi, Joshua O.

    2016-01-01

    CONTEXT Because of Nigeria’s low contraceptive prevalence, a substantial number of women have unintended pregnancies, many of which are resolved through clandestine abortion, despite the country’s restrictive abortion law. Up-to-date estimates of abortion incidence are needed. METHODS A widely used indirect methodology was used to estimate the incidence of abortion and unintended pregnancy in Nigeria in 2012. Data on provision of abortion and postabortion care were collected from a nationally representative sample of 772 health facilities, and estimates of the likelihood that women who have unsafe abortions experience complications and obtain treatment were collected from 194 health care professionals with a broad understanding of the abortion context in Nigeria. RESULTS An estimated 1.25 million induced abortions occurred in Nigeria in 2012, equivalent to a rate of 33 abortions per 1,000 women aged 15–49. The estimated unintended pregnancy rate was 59 per 1,000 women aged 15–49. Fifty-six percent of unintended pregnancies were resolved by abortion. About 212,000 women were treated for complications of unsafe abortion, representing a treatment rate of 5.6 per 1,000 women of reproductive age, and an additional 285,000 experienced serious health consequences but did not receive the treatment they needed. CONCLUSION Levels of unintended pregnancy and unsafe abortion continue to be high in Nigeria. Improvements in access to contraceptive services and in the provision of safe abortion and postabortion care services (as permitted by law) may help reduce maternal morbidity and mortality. PMID:26871725

  3. ABORT GAP CLEANING IN RHIC.

    SciTech Connect

    DREES,A.; AHRENS,L.; III FLILLER,R.; GASSNER,D.; MCINTYRE,G.T.; MICHNOFF,R.; TRBOJEVIC,D.

    2002-06-03

    During the RHIC Au-run in 2001 the 200 MHz storage cavity system was used for the first time. The rebucketing procedure caused significant beam debunching in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam could account for approximately 30%-40% of the total beam intensity. Some of it will be in the abort gap. In order to minimize the risk of magnet quenching due to uncontrolled beam losses at the time of a beam dump, a combination of a fast transverse kicker and copper collimators were used to clean the abort gap. This report gives an overview of the gap cleaning procedure and the achieved performance.

  4. Wind-mediated horseweed (Conyza canadensis) gene flow: pollen emission, dispersion, and deposition

    PubMed Central

    Huang, Haiyan; Ye, Rongjian; Qi, Meilan; Li, Xiangzhen; Miller, David R; Stewart, Charles Neal; DuBois, David W; Wang, Junming

    2015-01-01

    Abstract Horseweed (Conyza canadensis) is a problem weed in crop production because of its evolved resistance to glyphosate and other herbicides. Although horseweed is mainly self-pollinating, glyphosate-resistant (GR) horseweed can pollinate glyphosate-susceptible (GS) horseweed. To the best of our knowledge, however, there are no available data on horseweed pollen production, dispersion, and deposition relative to gene flow and the evolution of resistance. To help fill this knowledge gap, a 43-day field study was performed in Champaign, Illinois, USA in 2013 to characterize horseweed atmospheric pollen emission, dispersion, and deposition. Pollen concentration and deposition, coupled with atmospheric data, were measured in a source field (180 m by 46 m) and its surrounding areas up to 1 km downwind horizontally and up to 100 m vertically. The source strength (emission rate) ranged from 0 to 140 pollen grains per plant per second (1170 to 2.1×106 per plant per day). For the life of the study, the estimated number of pollen grains generated from this source field was 10.5×1010 (2.3×106 per plant). The release of horseweed pollen was not strongly correlated to meteorological data and may be mainly determined by horseweed physiology. Horseweed pollen reached heights of 80 to100 m, making long-distance transport possible. Normalized (by source data) pollen deposition with distance followed a negative-power exponential curve. Normalized pollen deposition was 2.5% even at 480 m downwind from the source edge. Correlation analysis showed that close to or inside the source field at lower heights (≤3 m) vertical transport was related to vertical wind speed, while horizontal pollen transport was related to horizontal wind speed. High relative humidity prevented pollen transport at greater heights (3–100 m) and longer distances (0–1000 m) from the source. This study can contribute to the understanding of how herbicide-resistance weeds or invasive plants affect

  5. Wind-mediated horseweed (Conyza canadensis) gene flow: pollen emission, dispersion, and deposition.

    PubMed

    Huang, Haiyan; Ye, Rongjian; Qi, Meilan; Li, Xiangzhen; Miller, David R; Stewart, Charles Neal; DuBois, David W; Wang, Junming

    2015-07-01

    Horseweed (Conyza canadensis) is a problem weed in crop production because of its evolved resistance to glyphosate and other herbicides. Although horseweed is mainly self-pollinating, glyphosate-resistant (GR) horseweed can pollinate glyphosate-susceptible (GS) horseweed. To the best of our knowledge, however, there are no available data on horseweed pollen production, dispersion, and deposition relative to gene flow and the evolution of resistance. To help fill this knowledge gap, a 43-day field study was performed in Champaign, Illinois, USA in 2013 to characterize horseweed atmospheric pollen emission, dispersion, and deposition. Pollen concentration and deposition, coupled with atmospheric data, were measured in a source field (180 m by 46 m) and its surrounding areas up to 1 km downwind horizontally and up to 100 m vertically. The source strength (emission rate) ranged from 0 to 140 pollen grains per plant per second (1170 to 2.1×10(6) per plant per day). For the life of the study, the estimated number of pollen grains generated from this source field was 10.5×10(10) (2.3×10(6) per plant). The release of horseweed pollen was not strongly correlated to meteorological data and may be mainly determined by horseweed physiology. Horseweed pollen reached heights of 80 to100 m, making long-distance transport possible. Normalized (by source data) pollen deposition with distance followed a negative-power exponential curve. Normalized pollen deposition was 2.5% even at 480 m downwind from the source edge. Correlation analysis showed that close to or inside the source field at lower heights (≤3 m) vertical transport was related to vertical wind speed, while horizontal pollen transport was related to horizontal wind speed. High relative humidity prevented pollen transport at greater heights (3-100 m) and longer distances (0-1000 m) from the source. This study can contribute to the understanding of how herbicide-resistance weeds or invasive plants affect ecology

  6. 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

  7. RHIC Abort Kicker Prefire Report

    SciTech Connect

    Tan, Y.; Perlstein, S.

    2014-07-07

    In an attempt to discover any pattern to prefire events, abort prefire kicker data from 2007 to the present day have been recorded. With the 2014 operations concluding, this comprises 8 years of prefire data. Any activities that the Pulsed Power Group did to decrease prefire occurrences were recorded as well, but some information may be missing. The following information is a compilation of the research to date.

  8. Expectant Fathers, Abortion, and Embryos.

    PubMed

    Purvis, Dara E

    2015-01-01

    One thread of abortion criticism, arguing that gender equality requires that men be allowed to terminate legal parental status and obligations, has reinforced the stereotype of men as uninterested in fatherhood. As courts facing disputes over stored pre-embryos weigh the equities of allowing implantation of the pre-embryos, this same gender stereotype has been increasingly incorporated into a legal balancing test, leading to troubling implications for ART and family law. PMID:26242955

  9. Effect of Bt-176 maize pollen on first instar larvae of the Peacock butterfly (Inachis io) (Lepidoptera; Nymphalidae).

    PubMed

    Felke, Martin; Langenbruch, Gustav-Adolf; Feiertag, Simon; Kassa, Adane

    2010-01-01

    More than 10 years after registration of the first Bt maize cultivar in Europe, there still exists a remarkable lack of data on effects on Lepidoptera which would be necessary for a complete and comprehensive environmental risk assessment. So far only very few European butterfly species have been tested in this aspect. In our study the effect of transgenic Bacillus thuringiensis (Bt) maize pollen (event Bt-176) on the development and survival of neonate larvae of the Peacock butterfly, Inachis io (L.) was for the first time shown. The results of our study suggest that the Peacock butterfly may serve as a model organism for assessing potential side effects of new developed transgenic Bt crops on non-target butterflies in a GMO environmental risk assessment. The study was done under laboratory conditions by exposing larvae of the Peacock butterfly to various pollen doses of transgenic maize event Bt-176 (cv. PACTOL CB) or the conventional isogenic maize (cv. PACTOL) using a no-choice test. Larvae feeding for 48 h on nettle plants (Urtica dioica) that were contaminated with higher pollen concentrations from Bt-176 maize (205 and 388 applied pollen.cm⁻²) suffered a significantly higher mortality rate (68 and 85% respectively) compared to larvae feeding on leaves with no pollen (11%), or feeding on leaves with pollen from conventional maize (6 to 25%). At lower Bt maize pollen doses (23-104 applied pollen.cm⁻²),mortality ranged from 11-25% and there were no apparent differences among treatments. The corresponding LC₅₀-and LC₉₀-values for neonate larvae of the Peacock butterfly were 187 and 448 applied pollen grains.cm⁻² of Bt-176, respectively.Weight of larvae surviving consumption of Bt-176 maize pollen declined between 10 and 81% with increased pollen doses (r = -0.95). The highest weight reduction (81%) corresponded to the highest pollen concentration (388 pollen grains applied.cm⁻²). Ingestion of pollen from the conventional maize hybrid did not

  10. 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

  11. [Request for abortion during the 2d pregnancy trimester].

    PubMed

    Treffers, P E; Van den Berg, G R; Jager-van Gelder, P A; Van Oenen, J J

    1976-12-18

    156 women, 12-20 weeks pregnant, applied for abortion at the Wilhelmo Clinic in Amsterdam; 102 abortions were granted. The 156 late-abortion seekers were compared with 282 early-abortion seekers and 490 pregnant women. The late-abortion seekers were significantly younger (P .05). A significantly greater number of women over 30 applied for early abortion (P .001). Unmarried or divorced women were more likely to apply to abortion (P .001). Nulliparae applied more frequently for late abortion, compared to early-abortion seekers (P .001). Women with only one child were more likely to be in the pregnancy group (p .05), with 2 children in the early-abortion group (p .001). Women from Surinam and the Antilles were more likely to be in the early abortion group (p .001). Of the late-abortion seekers, 9 had medical indications. Many had psychosocial problems; 91 had problems with partner relations. In 24 cases the delay in seeking abortion was due to a doctor. An ambivalent attitude toward the abortion existed in 22 of the patients. 83% of the late-abortion seekers and 11.3% of the early-abortion seekers had previously had an abortion. The contraceptive use of the late-abortion seekers was not regular. 1.3% of the late-abortion seekers and 9.9% of the early-abortion seekers were using IUDs at the time of conception. PMID:1012384

  12. Differential Impact of Abortion on Adolescents and Adults.

    ERIC Educational Resources Information Center

    Franz, Wanda; Reardon, David

    1992-01-01

    Compared adolescent and adult reactions to abortion among 252 women. Compared to adults, adolescents were significantly more likely to be dissatisfied with choice of abortion and with services received, to have abortions later in gestational period, to feel forced by circumstances to have abortion, to report being misinformed at time of abortion,…

  13. Inheritance of hetero-diploid pollen S-haplotype in self-compatible tetraploid Chinese cherry (Prunus pseudocerasus Lindl).

    PubMed

    Gu, Chao; Liu, Qing-Zhong; Yang, Ya-Nan; Zhang, Shu-Jun; Khan, Muhammad Awais; Wu, Jun; Zhang, Shao-Ling

    2013-01-01

    The breakdown of self-incompatibility, which could result from the accumulation of non-functional S-haplotypes or competitive interaction between two different functional S-haplotypes, has been studied extensively at the molecular level in tetraploid Rosaceae species. In this study, two tetraploid Chinese cherry (Prunus pseudocerasus) cultivars and one diploid sweet cherry (Prunus avium) cultivar were used to investigate the ploidy of pollen grains and inheritance of pollen-S alleles. Genetic analysis of the S-genotypes of two intercross-pollinated progenies showed that the pollen grains derived from Chinese cherry cultivars were hetero-diploid, and that the two S-haplotypes were made up of every combination of two of the four possible S-haplotypes. Moreover, the distributions of single S-haplotypes expressed in self- and intercross-pollinated progenies were in disequilibrium. The number of individuals of the two different S-haplotypes was unequal in two self-pollinated and two intercross-pollinated progenies. Notably, the number of individuals containing two different S-haplotypes (S1- and S5-, S5- and S8-, S1- and S4-haplotype) was larger than that of other individuals in the two self-pollinated progenies, indicating that some of these hetero-diploid pollen grains may have the capability to inactivate stylar S-RNase inside the pollen tube and grow better into the ovaries. PMID:23596519

  14. Genome-wide identification and analysis of rice genes preferentially expressed in pollen at an early developmental stage.

    PubMed

    Nguyen, Tien Dung; Moon, Sunok; Nguyen, Van Ngoc Tuyet; Gho, Yunsil; Chandran, Anil Kumar Nalini; Soh, Moon-Soo; Song, Jong Tae; An, Gynheung; Oh, Sung Aeong; Park, Soon Ki; Jung, Ki-Hong

    2016-09-01

    Microspore production using endogenous developmental programs has not been well studied. The main limitation is the difficulty in identifying genes preferentially expressed in pollen grains at early stages. To overcome this limitation, we collected transcriptome data from anthers and microspore/pollen and performed meta-expression analysis. Subsequently, we identified 410 genes showing preferential expression patterns in early developing pollen samples of both japonica and indica cultivars. The expression patterns of these genes are distinguishable from genes showing pollen mother cell or tapetum-preferred expression patterns. Gene Ontology enrichment and MapMan analyses indicated that microspores in rice are closely linked with protein degradation, nucleotide metabolism, and DNA biosynthesis and regulation, while the pollen mother cell or tapetum are strongly associated with cell wall metabolism, lipid metabolism, secondary metabolism, and RNA biosynthesis and regulation. We also generated transgenic lines under the control of the promoters of eight microspore-preferred genes and confirmed the preferred expression patterns in plants using the GUS reporting system. Furthermore, cis-regulatory element analysis revealed that pollen specific elements such as POLLEN1LELAT52, and 5659BOXLELAT5659 were commonly identified in the promoter regions of eight rice genes with more frequency than estimation. Our study will provide new sights on early pollen development in rice, a model crop plant. PMID:27356912

  15. From unwanted pregnancy to safe abortion: Sharing information about abortion in Asia through animation.

    PubMed

    Krishnan, Shweta; Dalvie, Suchitra

    2015-05-01

    Although unsafe abortion continues to be a leading cause of maternal mortality in many countries in Asia, the right to safe abortion remains highly stigmatized across the region. The Asia Safe Abortion Partnership, a regional network advocating for safe abortion, produced an animated short film entitled From Unwanted Pregnancy to Safe Abortion to show in conferences, schools and meetings in order to share knowledge about the barriers to safe abortion in Asia and to facilitate conversations on the right to safe abortion. This paper describes the making of this film, its objectives, content, dissemination and how it has been used. Our experience highlights the advantages of using animated films in addressing highly politicized and sensitive issues like abortion. Animation helped to create powerful advocacy material that does not homogenize the experiences of women across a diverse region, and at the same time emphasize the need for joint activities that express solidarity. PMID:26278840

  16. Abortion in Sri Lanka: The Double Standard

    PubMed Central

    2013-01-01

    In Sri Lanka, women do not have access to legal abortion except under life-saving circumstances. Clandestine abortion services are, however, available and quite accessible. Although safe specialist services are available to women who can afford them, others access services under unsafe and exploitative conditions. At the time of this writing, a draft bill that will legalize abortion in instances of rape, incest, and fetal abnormalities awaits approval, amid opposition. In this article, I explore the current push for legal reform as a solution to unsafe abortion. Although a welcome effort, this amendment alone will be insufficient to address the public health consequences of unsafe abortion in Sri Lanka because most women seek abortions for other reasons. Much broader legal and policy reform will be required. PMID:23327236

  17. Abortion in Sri Lanka: the double standard.

    PubMed

    Kumar, Ramya

    2013-03-01

    In Sri Lanka, women do not have access to legal abortion except under life-saving circumstances. Clandestine abortion services are, however, available and quite accessible. Although safe specialist services are available to women who can afford them, others access services under unsafe and exploitative conditions. At the time of this writing, a draft bill that will legalize abortion in instances of rape, incest, and fetal abnormalities awaits approval, amid opposition. In this article, I explore the current push for legal reform as a solution to unsafe abortion. Although a welcome effort, this amendment alone will be insufficient to address the public health consequences of unsafe abortion in Sri Lanka because most women seek abortions for other reasons. Much broader legal and policy reform will be required. PMID:23327236

  18. The abortion decision: reasons and ambivalence.

    PubMed

    Allanson, S; Astbury, J

    1995-09-01

    Self-in-relation theory and pilot data responses to an Abortion Decision Balance Sheet by 20 women attending an abortion-providing clinic challenge previous formulations of the abortion decision. Pilot data suggest that: women may make an abortion decision based primarily on pragmatics, a belief in their right to choose and knowledge of the safety and simplicity of the procedure. A discrepancy may exist for a significant minority of women between their abstract beliefs/knowledge and the personal meaning for them of the pregnancy, abortion and its safety. Important links may exist between maternal attachment and anxiety about the safety of the abortion procedure. Ramifications for counselling and future research are discussed. PMID:8528379

  19. 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

  20. Abortion checks at German-Dutch border.

    PubMed

    Von Baross, J

    1991-05-01

    The commentary on West German abortion law, particularly in illegal abortion in the Netherlands, finds the law restrictive and in violation of the dignity and rights of women. The Max-Planck Institute in 1990 published a study that found that a main point of prosecution between 1976 and 1986, as reported by Der Spiegal, was in border crossings from the Netherlands. It is estimated that 10,000 annually have abortions abroad, and 6,000 to 7,000 in the Netherlands. The procedure was for an official to stop a young person and query about drugs; later the woman would admit to an abortion, and be forced into a medical examination. The German Penal Code Section 218 stipulates abortion only for certain reasons testified to by a doctor other than the one performing the abortion. Counseling on available social assistance must be completed 3 days prior to the abortion. Many counseling offices are church related and opposed to abortions. Many doctors refuse legally to certify, and access to abortion is limited. The required hospital stay is 3-4 nights with no day care facilities. Penal Code Section 5 No. 9 allows prosecution for uncounseled illegal abortion. Abortion law reform is anticipated by the end of 1992 in the Bundestag due to the Treaty or the Unification of Germany. The Treaty states that the rights of the unborn child must be protected and that pregnant women relieve their distress in a way compatible with the Constitution, but improved over legal regulations from either West or East Germany, which permits abortion on request within 12 weeks of conception without counseling. It is hoped that the law will be liberalized and Penal Code Section 5 No. 9 will be abolished. PMID:12343177

  1. 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

  2. [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

  3. 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

  4. 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

  5. Abortion induced with methotrexate and misoprostol.

    PubMed Central

    Wiebe, E R

    1996-01-01

    OBJECTIVE: To determine the outcome and side effects of a new drug protocol to induce abortion. DESIGN: Case series. SETTING: An urban primary care practice. PATIENTS: One hundred consecutive patients who requested elective termination of pregnancies of less than 8 weeks' gestation. INTERVENTION: Subjects received methotrexate (50 mg/m2 body surface area, administered intramuscularly) and, 3 days afterward, misoprostol (800 micrograms, given vaginally). OUTCOME MEASURES: Number of abortions induced within 24 hours and within 10 days of misoprostol administration, number of surgical aspirations conducted because of incomplete abortion, mean amount of bleeding and pain and the number of women who, if faced with the same situation, said they would again choose a drug-induced abortion over a surgical one. RESULTS: Abortion occurred within 24 hours of misoprostol administration among 48 women and within 10 days among 69 women. In total, 89 women had an abortion without surgical aspiration. Of these women, 71 said they would choose a drug-induced abortion if faced with the choice again. CONCLUSION: Abortion induced with methotrexate and misoprostol appears to be a feasible alternative to surgical abortion and deserves further study. PMID:8548705

  6. Medical abortion in Australia: a short history.

    PubMed

    Baird, Barbara

    2015-11-01

    Surgical abortion has been provided liberally in Australia since the early 1970s, mainly in privately owned specialist clinics. The introduction of medical abortion, however, was deliberately obstructed and consequently significantly delayed when compared to similar countries. Mifepristone was approved for commercial import only in 2012 and listed as a government subsidised medicine in 2013. Despite optimism from those who seek to improve women's access to abortion, the increased availability of medical abortion has not yet addressed the disadvantage experienced by poor and non-metropolitan women. After telling the story of medical abortion in Australia, this paper considers the context through which it has become available since 2013. It argues that the integration of medical abortion into primary health care, which would locate abortion provision in new settings and expand women's access, has been constrained by the stigma attached to abortion, overly cautious institutionalised frameworks, and the lack of public health responsibility for abortion services. The paper draws on documentary sources and oral history interviews conducted in 2013 and 2015. PMID:26719008

  7. Abortion in Iranian legal system: a review.

    PubMed

    Abbasi, Mahmoud; Shamsi Gooshki, Ehsan; Allahbedashti, Neda

    2014-02-01

    Abortion traditionally means, "to miscarry" and is still known as a problem which societies has been trying to reduce its rate by using legal means. Despite the pregnant women and fetuses have being historically supported; abortion was firstly criminalized in 1926 in Iran, 20 years after establishment of modern legal system. During next 53 years this situation changed dramatically, so in 1979, the time of Islamic Revolution, aborting fetuses before 12 weeks and therapeutic abortion (TA) during all the pregnancy length was legitimate, based on regulations that used medical justification. After 1979 the situation changed into a totally conservative and restrictive approach and new Islamic concepts as "Blood Money" and "Ensoulment" entered the legal debates around abortion. During the next 33 years, again a trend of decriminalization for the act of abortion has been continuing. Reduction of punishments and omitting retaliation for criminal abortions, recognizing fetal and maternal medical indications including some immunologic problems as legitimate reasons for aborting fetuses before 4 months and omitting the fathers' consent as a necessary condition for TA are among these changes. The start point for this decriminalization process was public and professional need, which was responded by religious government, firstly by issuing juristic rulings (Fatwas) as a non-official way, followed by ratification of "Therapeutic Abortion Act" (TAA) and other regulations as an official pathway. Here, we have reviewed this trend of decriminalization, the role of public and professional request in initiating such process and the rule-based language of TAA. PMID:24338232

  8. Women's perceptions of first trimester spontaneous abortion.

    PubMed

    Wall-Haas, C L

    1985-01-01

    Fifteen to twenty percent of all pregnancies end in spontaneous abortion. For many women, this loss is nearly the equivalent of the loss of a real baby. To explore the complexity of women's responses to spontaneous abortion, nine women were given a questionnaire to complete regarding experiences and behaviors at the time of the miscarriage. The data revealed that each woman was affected, to some degree, by her experience with a spontaneous abortion. A comprehensive psychologic approach to this special client is needed to help more effectively the woman who aborts in the first trimester cope with the very real loss of an infant. PMID:3844461

  9. The male partner involved in legal abortion.

    PubMed

    Kero, A; Lalos, A; Högberg, U; Jacobsson, L

    1999-10-01

    This study comprises 75 men who have been involved in legal abortion. The men answered a questionnaire concerning living conditions and attitudes about pregnancy and abortion. Most men were found to be in stable relationships with good finances. More than half clearly stated that they wanted the woman to have an abortion while 20 stressed that they submitted themselves to their partner's decision. Only one man wanted the woman to complete the pregnancy. Apart from wanting children within functioning family units, the motivation for abortion revealed that the desire to have children depended on the ability to provide qualitatively good parenting. More than half the men had discussed with their partner what to do in event of pregnancy and half had decided to have an abortion if a pregnancy occurred. More than half expressed ambivalent feelings about the coming abortion, using words such as anxiety, responsibility, guilt, relief and grief. In spite of these contradictory feelings, prevailing expectations concerning lifestyle make abortion an acceptable form of birth control. A deeper understanding of the complexity of le