scholarly journals Aeromycology: studies of fungi in aeroplankton

2014 ◽  
Vol 10 ◽  
pp. 18-26 ◽  
Author(s):  
Małgorzata Jędryczka

Air is a natural environment for spores of many genera and species of fungi. Despite its small size and a significant dispersion they have a great impact on human health and different areas of our activities, such as agricultural production. The study on spores of fungi that belong to aeroplankton or bioaerosole is called aeromycology. The most frequent fungi present in the air are Cladosporium and Alternaria species. Their numbers are abundant regardless of latitude and height above the sea level and above the ground. They mostly originate from agricultural environment. Other frequently listed species of fungi, whose spores are present in the air include of Aspergillus, Penicillium, Fusarium, Sclerotinia and Ganoderma. The concentration of spores in the air strongly depends on the abundance of their formation during the studied period. This in turn relates to geobotanical region, vegetation, degree of urbanization, climatic conditions, season, current weather, wind force and direction, local microclimate, and many other factors. Changes in humidity affect the concentration of different types of fungal spores. In general they are divided to ‘dry’ (Alternaria, Cladosporium, Puccinia, Ustilago, Melampsora, Epicoccum, Drechslera) and ‘wet’ (Didymella, Fusarium, Ganoderma, Gliocladium, Leptosphaeria, Verticillium). Study of the composition of species and genera are being done using different types of spore samplers, mostly volumetric instruments. Visual identification is based on colony morphology of the fungus and the shape and size of spores. The identification at the species level is possible with molecular tools. Methods based on DNA/RNA amplification are very sensitive and accurate. They allow the identification below the species level, e.g. chemotypes, mating types or isolates with genes or alleles of interest. Aerobiological monitoring is widely used in the epidemiology of human diseases (inhalant allergies) and infections of arable crops (decision support systems for the protection of cultivated plants). Aeromycology is interconnected with such diverse areas as industrial aerobiology, bioterrorism, ecology, climatology or even speleology and cultural heritage.

2021 ◽  
Vol 13 (30) ◽  
pp. 13-19
Author(s):  
Vera Stefanova ◽  
◽  
Georgi Komitov ◽  

The idea of "seeing" machines developed violently after the entry of computer technology and industry 4.0 into mass production. The first task of the machine vision is the processing of images and their adjacent equipment, and its systems then include devices with digital inputs/outputs. These inputs/outputs are designed to control some kind of movement or operation of equipment, such as manipulators or automatic lines. The modern machine vision systems are a modern direction of technology that contains elements of computer technology, optics, mechanical systems and industrial automation. With their help, modern agrorobots perform orderly tasks such as visual identification, visual control, obstacle and position determination. This article presents an overview of certain applications of different machine vision systems suitable for use in agrorobots. It is known that they are autonomously powered and work in poor climatic conditions. In other cases, the machine vision in agrorobots must necessarily work in random oscillations and variable focal length, as well as with a wide assortment of objects for research. The article discusses the capabilities of different types of cameras and related software, the application of QR and laser technology for agrorobots.


2018 ◽  
Vol 11 (11) ◽  
pp. 6203-6230 ◽  
Author(s):  
Simon Ruske ◽  
David O. Topping ◽  
Virginia E. Foot ◽  
Andrew P. Morse ◽  
Martin W. Gallagher

Abstract. Primary biological aerosol including bacteria, fungal spores and pollen have important implications for public health and the environment. Such particles may have different concentrations of chemical fluorophores and will respond differently in the presence of ultraviolet light, potentially allowing for different types of biological aerosol to be discriminated. Development of ultraviolet light induced fluorescence (UV-LIF) instruments such as the Wideband Integrated Bioaerosol Sensor (WIBS) has allowed for size, morphology and fluorescence measurements to be collected in real-time. However, it is unclear without studying instrument responses in the laboratory, the extent to which different types of particles can be discriminated. Collection of laboratory data is vital to validate any approach used to analyse data and ensure that the data available is utilized as effectively as possible. In this paper a variety of methodologies are tested on a range of particles collected in the laboratory. Hierarchical agglomerative clustering (HAC) has been previously applied to UV-LIF data in a number of studies and is tested alongside other algorithms that could be used to solve the classification problem: Density Based Spectral Clustering and Noise (DBSCAN), k-means and gradient boosting. Whilst HAC was able to effectively discriminate between reference narrow-size distribution PSL particles, yielding a classification error of only 1.8 %, similar results were not obtained when testing on laboratory generated aerosol where the classification error was found to be between 11.5 % and 24.2 %. Furthermore, there is a large uncertainty in this approach in terms of the data preparation and the cluster index used, and we were unable to attain consistent results across the different sets of laboratory generated aerosol tested. The lowest classification errors were obtained using gradient boosting, where the misclassification rate was between 4.38 % and 5.42 %. The largest contribution to the error, in the case of the higher misclassification rate, was the pollen samples where 28.5 % of the samples were incorrectly classified as fungal spores. The technique was robust to changes in data preparation provided a fluorescent threshold was applied to the data. In the event that laboratory training data are unavailable, DBSCAN was found to be a potential alternative to HAC. In the case of one of the data sets where 22.9 % of the data were left unclassified we were able to produce three distinct clusters obtaining a classification error of only 1.42 % on the classified data. These results could not be replicated for the other data set where 26.8 % of the data were not classified and a classification error of 13.8 % was obtained. This method, like HAC, also appeared to be heavily dependent on data preparation, requiring a different selection of parameters depending on the preparation used. Further analysis will also be required to confirm our selection of the parameters when using this method on ambient data. There is a clear need for the collection of additional laboratory generated aerosol to improve interpretation of current databases and to aid in the analysis of data collected from an ambient environment. New instruments with a greater resolution are likely to improve on current discrimination between pollen, bacteria and fungal spores and even between different species, however the need for extensive laboratory data sets will grow as a result.


Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 937-937
Author(s):  
H. -D. Ihlenfeldt

The Mesembryanthemaceae, which inhabit the deserts and semi-deserts of Southern Africa, exhibit two very different types of epidermis. The first is characterized by thick outer cell walls encrusted by oxalate crystals, a thick cuticle and thick wax layers. In the second type, the epidermal cells exhibit only very thin outer cell walls, not encrusted by oxalate crystals, a very thin cuticle, and wax layers are poorly developed; the most prominent feature of this type is the occurrence of huge idioblasts often protruding as ‘bladder cells’. With regard to the climatic conditions in the native habitats this type of epidermis must be called ‘abnormal’. Both types of epidermis may form sculptures of three distinct size classes, which are not necessarily homologous. The function of these sculptures is still poorly understood. There is evidence that the sculptures influence the optical properties of the surfaces and thereby the radiation balance (and heat stress) of the leaves.From recent research, it has become evident that the two different types of epidermis are the anatomical expression of two different strategies for survival under extreme conditions. Species with the idioblast type of epidermis exhibit a strategy that might be called ‘opportunistic’. These species have developed a mechanism of gaining water from the atmosphere during the night under favourable conditions. There are indications that the idioblasts are involved in this mechanism.


2020 ◽  
Vol 12 (9) ◽  
pp. 3858 ◽  
Author(s):  
Magda Sibley ◽  
Antonio Peña-García

This paper presents the first comparative study of its type of the performance of light pipes with different types of apertures: a flat glass versus a bohemian crystal dome. Measurements were taken at 20-minute intervals over a period of one year in the bathrooms of two newly built identical houses of the same orientation located in Manchester, UK. The comparative analysis of the data collected for both light pipes types reveals that the crystal domed aperture consistently outperforms the flat glass one. Furthermore, the difference in the recorded horizontal illuminance is most marked during the winter months and at the end of the one-year experiment, indicating that the crystal dome has better performance for low incident winter light and higher resistance for the long term effect of weathering and pollution. This study provides strong evidence based on long term real measurements. Such evidence informs architects’ decisions when weighing up the aesthetic considerations of a flat glass aperture versus the higher illumination levels afforded by a crystal dome aperture with higher resistance to weathering and pollution.


2013 ◽  
Vol 1 (2) ◽  
pp. 59-61 ◽  
Author(s):  
S. Thirumala ◽  
Pradeep Nathu M. ◽  
H. B. Aravinda

Air borne fungi of Hill fort region of Channagiri is studied with help of Petriplate exposure method using Pottato dextrose agar media, petriplate exposure time is 15min. Sampling is taken in the month of  January 2013 total 74 fungal colonies represented 07 fungal types were observed during the present investigation period. Environmental condition plays an importance role in the distribution of the fungal spores. Out of 07 fungal species most numbers of fungi are anamorphic groups. The fungal species were Aspergillus, Pencillium, Curvilaria, Cladosporium, Fusarium Rhizopus, Alternaria species were identified. Aspergillus species (47.2%) showing maximum contribution is observed where as Rhizopus shows minimum contribution.DOI: http://dx.doi.org/10.3126/ijasbt.v1i2.8203 Int J Appl Sci Biotechnol, Vol. 1(2): 60-62


1940 ◽  
Vol 18c (7) ◽  
pp. 307-317 ◽  
Author(s):  
M. I. Timonin

The microbial population in the rhizosphere of wheat, oats, alfalfa, and peas was studied and the relative abundance of different types of micro-organisms recorded. By means of the plating method it was found that bacteria and actinomycetes were 7 to 71 times greater in the rhizosphere than in the soil distant from the roots, whereas fungi were but 0.75 to 3.1 times more numerous.Different varieties of plants affected the activity of the various groups of soil micro-organisms differently. Thus fungi were more numerous in the rhizosphere of oats, and bacteria in the rhizosphere of alfalfa. Seventeen genera of fungi were represented in isolates from the rhizosphere of seedlings and the soil distant from the roots. However, no marked difference was observed in the types isolated from the rhizosphere of different varieties of seedlings. A fungus isolated from the rhizosphere of alfalfa proved to be a new species and the genus Spicularia Persoon was amended to include it.


1993 ◽  
Vol 39 (1) ◽  
pp. 107-119 ◽  
Author(s):  
John Ogden ◽  
Rewi M. Newnham ◽  
Jonathan G. Palmer ◽  
Richard G. Serra ◽  
Neil D. Mitchell

AbstractTwenty-two plant species were identified from leaves, fruits, or flowers, and 41 taxa from pollen, present in a macrofossil (leaf) layer in a peat swamp formed on Pleistocene dunes on the Aupouri Peninsula in northern New Zealand. Eight genera of gymnosperms are represented. With the exception of Lagarostrobos colensoi, all tree species abundant as macrofossils are also common as pollen. Macrofossils enabled the on-site flora to be compared with the regional flora, represented by the pollen rain. Studies on leaf decomposition rates indicate bias toward sclerophyllous species in the macrofossils. Identification to species level and treering data from preserved kauri logs allow quantitative comparisons with similar extant communities. Current climatic conditions at those analogue sites are cooler (2° to 3°C), cloudier (11%), and much wetter (85%) than those currently prevailing on the Aupouri Peninsula. Dendrochronological results also suggest that the far north of New Zealand had a cooler, cloudier, and wetter climate at the time the fossil leaf assemblage was formed. Radiocarbon dates from possibly contaminated samples suggest that a diverse mixed gymnosperm/angiosperm forest, dominated by kauri (Agathis australis), was present about (or sometime before) 41,00034,000 yr B.P., when the leaf layer was formed. Similar temperature reductions have been postulated for this period in New Zealand by other authors.


Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 463-472
Author(s):  
Borivoj Pejic ◽  
Ksenija Mackic ◽  
Dragisa Milosev ◽  
Erkut Peksen ◽  
Srdjan Seremesic ◽  
...  

Mitigation of global climate change impact on the agricultural production is the major priorities in future research. Cowpea as a drought tolerant plant is interesting for growing in semi-arid climate of the Vojvodina region. The effect of water stress on yield of cultivated plants can be obtained by calculating the yield response factor (Ky) which represents the ratio between the relative evapotranspiration deficit (1-ETa/ETm) and the relative decline in yield (1-Ya/Ym). The values of Ky ranged from 0.91 to 1.17 for genotype G1 and G2 respectively. Genotype G1, with a value lower than 1 of Ky, shows a good tolerance to water deficit, on the contrary, genotype G2, with a greater Ky than 1, expresses some sensitivity to water stress. Obtained results will be used in breeding programs to develop cowpea cultivars tolerant to stressful conditions, primarily to water stress, as well as more productive in water use.


Sign in / Sign up

Export Citation Format

Share Document