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Free orbicules of Cupressaceae in daily aerobiological samples
No full textIntroduction: Pollen grains of Cupressaceae are a major cause of pollinosis, especially in Mediterranean countries (1,2), and a strong risk factor for allergic asthma (2, 3). Pollen and orbicules of Cupressaceae carry a carbohydrate epitope recognised by human IgE (4). However, while airborne pollen grains of Cupressaceae are commonly observed in aerobiological monitoring, free orbicules were never reported in aerobiological samples. We report (a) the presence of orbicules in Calocedrus decurrens (Torr.) Florin (Cupressaceae) and (b) the observation of free orbicules belonging to Cupressaceae in daily aerobiological samples.
Materials and Methods: Dried microsporophylls of Calocedrus decurrens (Torr.) Florin (Cupressaceae) were fixed to aluminum stubs with double adhesive carbon tape, sputter-coated with gold, and observed and photographed with a SEM (7) (JEOL JSM 5410, Jeol Ltd, Tokyo, Japan). Daily aerobiological samples were collected in Pisa, Italy with a “Lanzoni VPPS 2000” pollen trap installed in an urban area of Pisa about 17 m from the road pavement (Google maps coordinates 43.718343° N, 10.395110° E) and equipped with pre- siliconed sampling tape Silkostrip (Lanzoni). Sections corresponding to 24-hour intervals were cut from the tape, placed on microscope slides and stained with fuchsin jelly (5). The slides were then examined with optical (Leica Diaplan) and confocal microscope (Nikon A1plus) at 400x (6).
Results and discussion: The inner side of the tapetum and the outer side of the pollen exine of Calocedrus decurrens are covered by free, not embedded, orbicules ranging from 0.6 to 0.7 μm. Our observations are consistent with other researches supporting the hypothesis that orbicules may become airborne as loose particles when pollen grains are released from pollen sacs (8). Under the optical microscope, daily aerobiological samples sometimes exhibit clusters of very small, well stained dots, around Cupressaceae pollen grains. When the same samples are observed with the confocal microscope, the cluster is resolved in submicronic particles, ranging from 0.5 to 0.6 μm, with the same autofluorescence emission as the exine of the pollen grains, which leads us to identify them as orbicules (7). We were able to observe a large number of orbicules both on the exine of pollen grains of Cupressaceae and as loose bodies around them. Conclusions: For the first time, we proved that orbicules of Cupressaceae can be detected as loose particles in aerobiological samples at the same time of the “parental” pollen grains but vastly outnumbering them. On account of their smaller size, free orbicules can reach – and carry their allergenic load (4) - much deeper in respiratory systems than pollen grains. Although further cross-disciplinary research is needed, we hypothesize that free orbicules contribute to the strong correlation of airborne pollen grains of Cupressaceae with pollinosis
First aerobiological monitoring data in Pisa (Italy) within AIS-LIFE project
No full textIntroduction: One of the most important biological component of air is pollen, as its allergens are driver of airborne allergic diseases (1). Pollen allergy has a remarkable clinical impact over Europe. AIS LIFE ENV/IT/001107 project – Aerobiological Information Systems and allergic respiratory disease management (http://www.ais-life.eu), launched in 2014 (2), aims to assess the clinical impact of dissemination of pollen information. In this context, aerobiological monitoring was started in Pisa (Italy) for the first time. This contribution is the first report on aerobiological data ever collected in Pisa. The monitoring covers 21 months of operation of the pollen trap.
Materials and Methods: The sampling procedure and the count of the airborne pollen grains and fungal spores is based on UNI 11108:2004. Aerobiological samples were obtained with a “Lanzoni VPPS 2000” pollen trap installed on top of the Biology Department building in Pisa, via Derna 1, about 17 m above the road pavement (coordinates 43.718343° N, 10.395110° E). Pollen grains of eight families: Betulaceae, Cupressaceae – Taxaceae, Asteraceae, Fagacee, Oleaceae, Urticaceae, Poaceae, Platanaceae and spores of Alternaria sp.pl. have been counted every day since 4 November 2014. Cycles of pollination and sporulation, the main pollen seasons (MPS), and the main spore season (MSS) were calculated according to 3, 4. Meteorological data were obtained from www.meteopisa.it and from a weather station placed next to the pollen trap.
Results and discussion: We recorded a cumulative value of 25377.55 pollen grains per m3 and 1202.85 fungal spores per m3 from January to May 2016; the same values for the whole 2015 are 38781.49 and 12846.02 respectively. As regards woody species, the highest value was contributed by Cupressaceae – Taxaceae families, with 6820.5 pollen grains in 2016 and 16032.5 in 2015; followed by Platanaceae with 2229.15 pollen grains in 2016 and 1625.03 in 2015; Coryloideae subfamily with 2794.55 pollen grains in 2016 and 866.47 in 2015.
As regards MPS, Betuloideae subfamily lasted 79 days in 2016 and 88 in 2015. The starting date for Betuloideae subfamily varied from 32 days in 2016 to 46 in 2015. As regards the ending date, Betuloideae varied with 111 days in 2016 and with 134 days in 2015.
The average temperature of the period 1 January-31 March was 10.6°C in 2016 and 9.8°C in 2015; in the same periods total rainfall was 391 mm and 205 mm respectively. Therefore our data may suggest a correlation between pollen concentration of woody species and meteorological factors, consistent with observations reported in other studies (5).
Conclusions: The aerobiological monitoring campaign started in Pisa in 2014 is providing scientific data in support of an on-going European project addressing the clinical impact of dissemination of airborne pollen information. The aerobiological monitoring represents a unique tool to supply local real data to allergologists, enabling them to calibrate the drugs therapy for their patients and providing immediate advantages both for patients' health and for better management of the national healthcare system (6). The data obtained from the aerobiological monitoring will be useful for other applications as well, from biology and medicine to agriculture. Analysis of changes in MPS and MSS may help in detecting local changes in climate factors
Free orbicules of Cupressaceae detected in daily aerobiological samples by optical and confocal microscopy
No full textMembers of Cupressaceae and Taxaceae are known to release large amounts of highly allergenic pollen grains into the atmosphere, which are responsible for the onset of pollinosis in many countries throughout the world. In addition to pollen grains, their pollen sacs produce orbicules, which are submicron particles reported to carry allergens and which are potentially able to reach much further down the respiratory tract than pollen grains. Previous research has postulated the presence of orbicules in the atmosphere; however, direct observations have not yet been reported. The aim of this research was to provide the first direct evidence that Cupressaceae orbicules are released into the atmosphere by detecting them in daily aerobiological samples. We observed pollen sacs, pollen grains, and orbicules of nine species of Cupressaceae using scanning electron microscope (SEM). We then used a light and confocal microscope, to examine daily aerobiological samples. Under SEM, we measured the orbicule size (0.494â0.777 Âμm) and detected unknown nanometric particles (130â200 nm). Under the light microscope, aerobiological samples showed clusters of stained dots surrounding the pollen grains of Cupressaceae. Under the confocal microscope, the same clusters were resolved into submicron particles with the same autofluorescence as the pollen grains. These features enabled us to identify them as orbicules. We believe that our findings help to explain the onset of pollinosis and allergic asthma related to Cupressaceae pollen grains in many countries, even before pollen grains are actually detected or after they are no longer observed in aerobiological monitoring samples
Systematic and morphologic survey of orbicules in allergenic angiosperms
No full textOrbicules are sub- or pauci-micronic sporopollenin-coated particles associated with pollen grains. Recent studies have highlighted their importance in terms of systematic value or as vectors of allergens that may trigger pollinosis. While orbicules have indeed been reported for most families and genera of allergological importance, their usefulness in systematics remains little explored. Our study aims: (a) to discover the presence/absence of orbicules in species of allergological interest hitherto overlooked regarding these particles; (b) to propose standard descriptors for orbicule morphology; and (c) to link the features of orbicules to a systematic framework. We observed or measured selected orbicule traits in SEM micrographs of pollen sacs and pollen grains of 23 species of 17 genera in Asteraceae, Betulaceae, Fagaceae, Oleaceae, Poaceae, Plantaginaceae and Polygonaceae families. Categorical and continuous traits were included in a matrix and then subjected to NMDS as ordination method to assess the usefulness of orbicule traits as systematic characters. We detected orbicules both on the locule wall and on the pollen exine in almost all investigated species and described unknown nanoparticles smaller than orbicules. Based on orbicules traits, NMDS separated the samples at species level. We detected and described orbicules on the tapetum and on the pollen exine in 19 target species and observed unknown nanoparticles that might explain (a) the process of deposition of sporopollenin during orbicule development and (b) the onset of pollinosis before and after the dispersion of pollen grains into the air. Finally, within the restricted sample examined, selected orbicule traits allowed to resolve the data set at species level
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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