ISSN:0017-3134    

DOI:10.1080/00173138609427716

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The pollen grains of 28 samples representing six species and four subspecies ofChimaphilaPursh were examined by light and scanning electron microscopy.Chimaphilapollen is characterized by polyads composed of an indefinite number of tetrads which is distinct from the pollen in the other genera of the Pyrolaceae, the monads ofOrthiliaand the tetrads ofPyrolaandMoneses. The variation in polyad size among the samples is examined and the confusing terms polyad and massula are clearly redefined. The pollen characters present no distinct differences within the genus, except inC. domingensisBlake, which has a rugulate pollen sculpture. The pollen characters confirm the unity and distinctness ofChimaphilain the Pyrolaceae.

ISSN:0017-3134    

DOI:10.1080/00173138609427717

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The pollen morphology of 12 taxa belonging to four genera of Boraginaceae have been investigated by LM and SEM. The pollen grains vary from genus to genus, and even in some species. In general, the pollen grains are small, isopolar, sometimes subisopolar, colporate with four, five or more apertures; apertural membrane granular. Exine tectate, tectum psilate. The taxonomic implications of the pollen morphological features are discussed.

ISSN:0017-3134    

DOI:10.1080/00173138609427718

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The Dakhleh Oasis lies at the heart of the Western Egyptian Desert. Measurable precipitation occurs at rare intervals and the mean annual rainfall is <0.5 mm. Artesian water supports the pastoral agricultural economy of the oasis. The vegetation consists of fragmentary natural communities of Saharo-Arabian species and a predominant anthropogenic component. Twenty-five samples were analysed for modern pollen—5 Tauber traps placed in a horticultural station; 18 surface muds from permanent pools or ditches; and 2 relict pond sediments on the plateaux above the oasis depression. The Tauber trap spectra are dominated by local, introduced taxa, with small percentages (1–3) of long-distance (Mediterranean region) elements and Saharo-Arabian, native elements (0–2). The relict pond samples and to a lesser extent the ditch and pond muds contain constant though small percentages (5–7%) of native desert species of indicator value, large proportions of ubiquitous taxa (chiefly Cheno-Amaranth, Cyperaceae and Gramineae), smaller proportions of naturalized anemophilous trees (CasuarinaandEucalyptus), and scattered occurrences in low frequencies of such allochthonous, Mediterranean taxa as alder, birch, pine and oak.

ISSN:0017-3134    

DOI:10.1080/00173138609427719

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Mean annual pollen influx values are presented for 20 sites within the open spruce dominated forests of Kuusamo, Finland. These are seen to reflect the local vegetation in terms of small-scale differences, particularly in the NAP but to have dominant features which represent the regional vegetation. A pollen analogue is suggested for this regional forest expressed in terms of pollen influx, species representation and percentage presence. This is then compared with results from other areas and seen to be sufficiently different to be characteristic. Some aspects of pollen trapping with respect to the sedimentary environment and length of sampling period are examined and recommendations for future trapping programmes are made. The advantages of influx values over percentage ones are emphasized.

ISSN:0017-3134    

DOI:10.1080/00173138609427720

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Une étude aéropalynologique limitée aux Oleacées de la région urbaine de Gênes a été élaborée de 1981 à 1983. Dans cette régionOlea europaeaest très repandue et les symptômes allergiques causés par le pollen d'Olivier sont assez communs. Le prélèvement de pollen a été effectué à l'aide d'un aspirateur Hirst-Burkard. L'examen au microscope (agrandissement ×400) exprime le nombre de pollens par jour et par m3d'air. Plusieurs périodes de dispersion ont été mises en évidence; la première en avril-mai avec le pollen deFraxinuset dePhillyreaaux valeurs bien modestes et la seconde, d'une plus grande durée et intensité due surtout àOlea europaeaet partiellement àLigustrum, dont les maxima correspondent au mois de mai et juin. La période principale de dispersion a été calculée plus en détail à partir du mois d'avril jusqu'au juillet 1983. Grâce à la teneur en pollens plutôt elevée, l'étude a permis la corrélation de la teneur en pollens avec des facteurs météorologiques: la pression atmosphérique, et les precipitations atmosphérique, la température, l'humidité relative, la vitesse du vent et la durée d'insolation. En ce qui concerne l'aspect allérgologique,Olea europaease place parmi les espèces les plus significatives de la région de Gênes avec une incidence d'environs 15% de réactions positives aux tests cutanés des individus atteints de pollinose. L'examen des facteurs météorologiques et leur correlation avec l'analyse pollinique, a une très importante valeur prognostique, relative à la diffusion du pollen par voie aérienne.

ISSN:0017-3134    

DOI:10.1080/00173138609427721

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0017-3134    

DOI:10.1080/00173138609427722

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Burkard volumetric samplers were used to carry out research on airborne pollen in the Ascoli Piceno and Siena atmosphere in the period April-September 1981. Total production in the period in question was quantitatively similar, with a prevalence of non-arboreal pollen in both stations. The overall trend has shown a positive correlation between the two stations. Differences were recorded with regard to the period of pollination and the quantity of pollen produced byQuercus, Poaceae, Oleaceae,Castanea, Plantaginaceae and Compositae.

ISSN:0017-3134    

DOI:10.1080/00173138609427723

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Strategies for reducing exposure to ragweed pollen are given a quantitative basis on the relationship between the distributions of ambient air ragweed pollen, its sources, and the urban population. Avoidance of a major fraction of the seasonal dosage is possible at little cost, particularly if the influences of day-to-day weather changes on the pollen count are known. Techniques are presented for estimating both the likely day-to-day pollen count and the influence of avoidance time patterns on dosage. Through a mathematical optimization method, the avoidance strategies can be made more efficient and uncertainties in the dosage reduction they are likely to achieve can be reduced. Ragweed plant control, however optimally carried out, is economically impractical here at the levels required to significantly reduce urban pollen counts. A public health program giving the pollen count effective meaning is described based on these findings.

ISSN:0017-3134    

DOI:10.1080/00173138609427724

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Aeroallergens of the southeastern Missouri region were determined by skin test frequencies of 817 consecutive individuals and compared and contrasted with five years of air sampling using the Rotorod sampler. Household inhalants were found to induce the most frequently positive skin tests, especially house dust, feathers, house dust mite, wool, cat epithelium, tobacco, dog epithelium, and horse epithelium. Among the trees, pollen extracts ofAcer saccharum(maple),Acer negundo(box-elder),Carya ovata/C. illinoensis(hickory/pecan),Juglans nigra(walnut), andUlmus americana(elm) were the most commonly positive. A slightly higher level of skin reactivity was found to grass pollen extracts withAnlhoxanthum odoralum(sweet vernal),Phleum pratense(timothy),Cynodon dactylon(Bermuda),Agrostis alba(red top) andFestuca elatior(meadow fescue), all being quite similar in incidence, butSorghum halepense(Johnson grass) was clearly less important.Ambrosiaspp. (ragweed) andXanthium commune(cocklebur) were the most frequent weed reactions with ragweed the most prominent allergen of outside environmental origin. Of the genera of fungi, skin tests toEpicoccumwere most frequently positive. When reactivity level is considered, the other important fungi areAlternaria, Candida, Cladosporium, Curvularia, andFusarium. Air sampling data generally correlates well with the positive skin tests frequencies i.e., the most numerous pollen, ragweed, has the highest skin test frequency and reactivity level. Similarly among the fungi the most numerous spores,Cladosporium, Alternaria, Fusarium, andEpicoccumhave the highest frequencies and reactivity levels. Certain species appear to be able to sensitize patients in lower concentrations, such as box-elder and the grasses. Oak pollen andCladosporiumspores appear in large numbers, but seem less sensitizing.

ISSN:0017-3134    

DOI:10.1080/00173138609427725

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor