6,067 research outputs found
Oribatid assemblies of tropical high mountains on some points of the âGondwana-Bridgeâ â a case study
This work is the first part of a series of studies, which introduces the methodological possibilities of coenological and zoogeographical indication and â following the climate, vegetation and elevation zones â the pattern-describing analysis of the main Oribatid sinusia of the world explored till our days.This current work is a case-study, which displays the comparison of 9 examination sites from 3
different geographical locations. On each location, three vegetation types have been examined: a plain
rain-forest, a mossforest and a mountainous paramo. Analyses are based on the hitherto non-published
genus-level database and coenological tables of the deceased JĂĄnos Balogh professor. Occurrence of 18
genera is going to be published as new data for the given zoogeographical region
Bibliography and checklist of foliicolous lichenized fungi up to 1992
Bibliographic records are presented of 324 scientific papers on foliicolous lichenized fungi published subsequent to Santessonâs survey of 1952. The 482 species presently known are listed in an alphabetical checklist, with references to important descriptions, keys and illustrations published by or after Santesson (1952), and an indication of the distribution. Also added are all synonyms used after 1952. Introductory chapters deal with the present state of research on foliicolous lichens and its history. The following new combination is proposed: Strigula smaragdula Fr. var. stellata (Nyl. & Cromb.) Farkas
Names of Bacidia s. l. in current use for foliicolous lichens â an annotated nomenclatural study
Abstract
The checklist contains 135 names in current use for taxa of former Bacidia s. l. and 99 synonyms or invalid names. Place of description or new combination, basionym, synonyms, type, distribution is given for species. Type species, substrate, number of foliicolous species, systematic position, distribution is given for genera. Data are edited similarly with the online checklist on foliicolous lichens last updated by LĂŒcking and his co-authors in 2000. The list contains the following 7 new combinations: Bacidina cinnamomea (Kremp.) Farkas, Bacidina clauzadei (SĂ©rus. et Lambinon) Farkas, Brasilicia foliicola (VÄzda) Farkas, Brasilicia ituriensis (VÄzda) Farkas, Brasilicia olivaceorufa (Vain.) Farkas, Brasilicia subsimilis (VÄzda) Farkas, Szczawinskia permira (VÄzda) Farkas. The genus Bacidia De Not. is excluded from the checklist of foliicolous lichens, as all of its former foliicolous species are now belonging to other genera. Current names are in the following 12 genera: Bacidina, Badimia, Badimiella, Baflavia, Bapalmuia, Barubria, Brasilicia, Eugeniella, Fellhanera, Fellhaneropsis, Scoliciosporum and Szczawinskia
Foliicolous lichen collections on Mount Kanga, Tanzania (East Africa)
Abstract
The Tanzanian Mt Kanga was at first visited by TamĂĄs PĂłcs in 1987 when he collected foliicolous lichens in lowland rainforest between 800 and 900 m elevation and in submontane rainforest between 900 and 1,250 m. Later, in 1989 he returned there with participants of the Nguru Mts expedition, when the author collected further lichens including foliicolous ones in three different forest types (dry evergreen and semi-evergreen forest at 600â800 m, submontane rainforest at 850â1,200 m and rocky forest at 1,200â1,300 m). Altogether 37 species became known from the area. The comparison of collections revealed that submontane rainforests (including rocky forests) are the richest of the studied forest types in foliicolous lichens. Mt Kanga is characterised by rare species like Calopadia editae discovered by AntonĂn VÄzda in material from Mt Kanga, described and validated in 2011 by Chaves and LĂŒcking based on materials from Mt Kanga and Costa Rica. The new combination Brasilicia dimerelloides (VÄzda) Farkas is introduced. The palaeotropical Fouragea viridistellata (SĂ©rus., LĂŒcking et Sparrius) Ertz et Frisch described in 2008 is reported here as new for Tanzania
Revisiting the stability of spatially heterogeneous predator-prey systems under eutrophication
We employ partial integro-differential equations to model trophic interaction
in a spatially extended heterogeneous environment. Compared to classical
reaction-diffusion models, this framework allows us to more realistically
describe the situation where movement of individuals occurs on a faster time
scale than the demographic (population) time scale, and we cannot determine
population growth based on local density. However, most of the results reported
so far for such systems have only been verified numerically and for a
particular choice of model functions, which obviously casts doubts about these
findings. In this paper, we analyse a class of integro-differential
predator-prey models with a highly mobile predator in a heterogeneous
environment, and we reveal the main factors stabilizing such systems. In
particular, we explore an ecologically relevant case of interactions in a
highly eutrophic environment, where the prey carrying capacity can be formally
set to 'infinity'. We investigate two main scenarios: (i) the spatial gradient
of the growth rate is due to abiotic factors only, and (ii) the local growth
rate depends on the global density distribution across the environment (e.g.
due to non-local self-shading). For an arbitrary spatial gradient of the prey
growth rate, we analytically investigate the possibility of the predator-prey
equilibrium in such systems and we explore the conditions of stability of this
equilibrium. In particular, we demonstrate that for a Holling type I (linear)
functional response, the predator can stabilize the system at low prey density
even for an 'unlimited' carrying capacity. We conclude that the interplay
between spatial heterogeneity in the prey growth and fast displacement of the
predator across the habitat works as an efficient stabilizing mechanism.Comment: 2 figures; appendices available on request. To appear in the Bulletin
of Mathematical Biolog
Use of conductimetric technique for data capture in predictive microbiology
Conductimetry as an alternative data capture method for following microbial growth has a great potential as a research tool of predictive microbiology. In spite of this fact there is only a limited number of applications using conductimetric data for model generation. In this study the growth of single strains of Listeria monocytogenes and Lactococcus lactis was tested in 5 media using a RABITinstrument. The goal of the work was to find selective growth media for Listeria and Lactococcus, respectively, in order to study their interaction in mixed-culture using the conductimetric technique. Whitley Anaerobic broth, Whitley Impedance broth and modified Whitely Impedance broth (Whitley Impedance broth + Chloramphenicol 7 mg l Ś1) were not suitable for following selectively the growth of Lactococcus lactis or Listeria monocytogenes in a mixed culture of the two bacteria. BiMedia 630 A for Lactococcus lactis and Bimedia 403 A for Listeria monocytogenes satisfied the demands raised by conductance measurement. Linear correlations were established between the graphically estimated TTD values of the conductance curves and the logarithmic numbers of colony forming units (CFU). The correlations were very strong in each case (determination coefficients (R 2) of the linear regression were higher than 0.98 at both medium-strain combinations). However, in BiMedia 630 Listeria monocytogenes was capable of slow growth, therefore, this medium would be feasible for studying microbial interactions if only low concentrations of Listeria (less than 10 6 CFU ml Ś1) were present in the mixed culture
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