National Repository of Grey Literature 12,821 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Study on dynamics of spinning apparatus of some wolf spiders (Araneae: Lycosidae) during their life cycle
Dolejš, Petr ; Smrž, Jaroslav (advisor) ; Žďárek, Jan (referee) ; Hajer, Jaromír (referee)
Current knowledge of the spinning apparatus comes namely from studies on orb web spiders and their relatives, whereas that of wolf spiders were more or less neglected. Therefore, developmental changes of the spinning apparatus of four wolf spiders were studied throughout their life cycles. Each of these lycosids possesses stenochronous life cycle with similar number of instars (7-10) but of different length (1-3 years). There is only one period of reproduction in spring/summer in all four species. Sperms are being formed just after the final moult; diplotene in some species is peculiar. The courtship behaviour reflects the microhabitat occupied by the concrete spider species; the copulations are species specific. Ontogeny of the spinning apparatus of developing spiderlings was observed: The spinning apparatus initiate its function in the first instar. Secondary ampullate, all piriform and all but four aciniform glands are tartipore-accommodated; they do not moult in situ. The tartipores, vestigial structures corresponding to spigots of the previous instar, appear on the spinning field starting with the second instar. Tartipore-accommodated glands play roles also during proecdysis and their evolution corresponds with the way how do the spiders secure themselves when moulting. Hence, the not yet...
Plasma-membrane alkali-metal-cation transporters involved in salt tolerance of pathogenic Candida species
Krauke, Yannick ; Sychrová, Hana (advisor) ; Malcová, Ivana (referee) ; Heidingsfeld, Olga (referee)
of Ph.D.Thesis Conclusions All the aims of the thesis were achieved.The toleranceto alkali metalcationsof four pathogenic Candida species was studied in detail and revealed differencesamong the yeasts. These differences in sall tolerance remained the same under various growth conditions.For the first time, the internalsodium and potassiumconcentrationsof several Candidaspecieswere estimatedunder highsalt-stressgrolvth.The internalK./Na* ratiowas not in relationwith the salt tolerancerevealingdifferentadaptationmechanismsto salt stress in Candida species. A first study on combinatoryuse of fluconazoleand NaCl revealed severe synergisticeffects of both compounds, leading to grovvthinhibitionand increased internalNa* concentrationsin C. albicans.The molecularbasis of this synergismremainsto be established. Ihe C. dubliniensis, C. glabrata and C. parapsilosis Cnhl NalH- antiporters were cloned and functionallycharacterizedupon heterologousexpression in S. cerevlslae to understandthe mechanismsinvolvedin the differentsalttolerancesof Candidaspecies.The three antiportersdifferedin theiractivityfor alkalimetalcations,which roughlycorrelatedwith the observed differences in salt tolerance among the species. Additionally,during the characterizationof heteroiogouslyexpressed antiporters,two antiporter chimeras...
Contaminant mobility and toxicity in soil profiles in the Mufulira smelting area (Copperbelt, Zambia)
Konečný, Ladislav ; Ettler, Vojtěch (advisor) ; Frouz, Jan (referee)
ii SUMMARY The smelter in Mufulira is one of the several active copper smelters in Copperbelt area in Zambia. It had operated for almost 70 years and during that period all offgas and dust were released into the atmosphere. Six profiles, three of them beneath trees, were sampled in the distances of 3.6, 8 and 24 km from the smelter. Each profile consisted of 9-10 layers collected continuously from the topsoil till depth of 60-70 cm. Following parameters were measured for each layer: pH, TC, TS a CEC, then total concentration of Ag, As, Al, Fe, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Sn, V a Zn and extractability by EDTA. The total concentrations of metals/metalloids were measured by ICP-OES and quadrupole- based ICP-MS. TC and TS were determined by thermal analysis and mobility of metals was assessed according to their extractability by EDTA. The aim of this work was to compare vertical distribution and mobility especially of these metals Co, Cr, Cu, Pb, V and Zn among profiles. Finally a standardized toxicity test was performed with ten selected layers (include all top soils) from all profiles. This reproductive test with Enchytraeus crypticus reflected how tested soil samples were suitable for living and reproducing this specimen of invertebrates. Generally the total concentrations of metals decreased in...
Taxonomy of species of the genus Lachnum s.I. in Central Europe
Chlebická, Markéta ; Holec, Jan (advisor) ; Pažoutová, Sylva (referee) ; Baral, Hans-Otto (referee)
Aims of the thesis The generalobjectiveof thethesisv/asto taxonomically evaluatethe rich materialof Lachnurn s.l. depositedin Czech herbaria,as well as the personal ťreldcollections. In the case of taxonomic or nomenclatural problems, the problematic groups were studied in detail. Various methods were used to solve the taxonomic problems and important collections from other herbariawere also studied. Outline of the thesis Problematic groups in Lachnum. I paid attentionto lignicolous and herbicolous species of Lachnum and to the group of Lachnum pygmaeum (Article III, VII) from the taxonomicpoint of view. Field collections of the whole spectrumoťLachnum specieswere included to the check-list (Article I). Species concept in Capitotricha. Central European species of Capitotricha with asci arising from simple septa were sequenced and a larger set of data supplementingthe previously known sequencewas obtained and analysed. Interesting data on Capitotricha species from Nothofagus from southern hemisphere were obtained. Long-spored lignicolous species of the genus Erioscyphella Kirschst. close to Lachnum and Capitotricha from the tropics and subtropics were also studiedanddiscussed. Taxonomy of Trichopeziza. Tbere was a lot of confusion connected with the name Peziza sulphurea Pers. At first, it was used for a...
Analysis of factors affecting human preferences and thus effort given to the conservation of animal species
Lišková, Silvie ; Frynta, Daniel (advisor) ; Komárek, Stanislav (referee) ; Sedláček, František (referee)
Recently, it was reported that humans treat animals that they perceive as aesthetically attractive unequally to the "ugly" ones, turning more attention to them and setting more conservation programs for their protection. The aim of this thesis was to investigate the issue focusing around animal beauty in more detail by examining human preferences towards one of the most popular animal taxon, the birds. In three subsequent studies, we assessed human preferences towards selected bird species: all members of the order of parrots, randomly selected representatives of all non- passerine bird families, and all members of the vividly colored passerine family Pittidae. The first study revealed that the preferred parrots were kept in zoos in higher numbers, regardless of their conservation priority (IUCN status). We discussed possible consequences of this finding and the benefits that may arise in the light of animal conservation if this bias in species preferences was to be considered by conservation specialists. We also found that people preferred long-tailed parrots possessing blue and yellow colors over green ones, which were probably perceived as dull and uninteresting as the majority of the parrots are fully or partially green. In the next two studies, we found that shape, pattern, and overall...
Shell shape variability in selected members of family Geoemydidae
Protiva, Tomáš ; Rehák, Ivan (advisor) ; Šmíd, Jiří (referee) ; Široký, Pavel (referee)
Turtles always fascinated men primarily by morphology, unique embryogenesis and later also by uncertain phylogenetic position. As this group exists for 200 Mya, with taxon Odontochelys and Proganochelys identified as the first ancestors, recently they are endangered by habitat destruction and hunting for meat. The worst situation is in Asia, with China as the most important consumer of turtle meat and other products. Captive breeding programs may be the only chance for lot of almost extinct species. Proper taxonomic and geographical determination is crucial for correct management of rescue programs. Shell shape variability studied by geometric morphometric method and supported by genetics is the right tool for this task. My thesis is focused on verification of the use of geometric morphometric method for selected species of family Geoemydidae. This family has centre of distribution in Asia and many of its species are endangered by so called Asian Turtle Crisis. We found unusual high occurrence of supernumerary vertebral scute in Morenia petersi. Shape of the carapace and plastron is not affected by presence of this extra scute. There are no significant differences between turtles with additional scute and turtles with normal five vertebral layouts. Scute pattern with supernumerary vertebral scute...
Genus Apodemus (Mammalia: Rodentia) in the Quaternary fossil record of Central Europe.
Knitlová, Markéta ; Horáček, Ivan (advisor) ; Macholán, Miloš (referee) ; Čermák, Stanislav (referee)
Wood mice of the genus Apodemus rank among the most common extant mammals throughout Europe. A history of its species and their distributional ranges is to be looked upon as a serious topic relevant also for general concepts on current setting of European biotic diversity. Nevertheless, despite several phylogeographic studies on that subject and a rich fossil record of the genus, many details of that issue remains only very poorly comprehended. This state is essentially caused by enormous complications with phenotype discrimination of individual species, their extensive variation and broad between-species overlaps in all phenotype traits. The present project was intended to establish the techniques enabling reliable species identification applicable to fragmentary fossil materials and to use them for retrieving information on range dynamics and phylogenetic history of individual species during the Quaternary past. It begun with detailed morphometric analyses of extant populations, using the characters available in fossils, and with establishing a concept of alternative parataxonomic classification covering the complete phenotype span of the genus. The respective techniques were applied onto an extensive set of well-dated records from the Late Pleistocene-Holocene sedimentary series from diverse...
Fylogeneze vybraných druhů letounů Afriky na základě cytogenetického a molekulárního přístupu
Koubínová, Darina ; Zima, Jan (advisor) ; Macholán, Miloš (referee) ; Martínková, Natália (referee)
Phylogenetic relationships of a sample comprising 248 bats belonging to 19 species and four families (Hipposideridae, Rhinolophidae, Molossidae and Vespertilionidae) from Senegal (Western Africa) were investigated with the use of multi-locus sequence data and non- differentially stained chromosomes. The karyotypes of Hipposideros ruber, H. tephrus, H. jonesi and H. cyclops were described for the first time. The standard Hipposideros formula was recorded in H. tephrus, H. jonesi and H. ruber (2n = 32, FNa = 60, FN = 64). The karyotypes of H. cyclops (2n = 36, FN = 66) and H. gigas (2n = 52, FN = 64) substantially diverged from this typical chromosomal complement. Rhinolophus landeri and R. fumigatus shared the same diploid number (2n = 58), but differed in the chromosome morphology (R. fumigatus - FNa = 60, FN = 64; R. landeri - FNa = 64, FN = 68). Rhinolophus landeri was found karyotypically distinct to other African populations, thus signalling a possible presence of cryptic forms within this species. The karyotypes of Chaerephon pumilus and Mops condylurus had a 2n = 48, FN = 54 and were similar to other previously studied species of this chromosomally conservative family. Chromosomal, Bayesian, maximum likelihood and genetic distance analyses revealed an indication for the existence of cryptic...
Molecular phylogeny and evolutionary trends in Hieracium (Asteraceae, Lactuceae)
Krak, Karol ; Fehrer, Judith (advisor) ; Zozomová, Judita (referee) ; Nieto Feliner, Gonzalo (referee)
The hawkweed subgenus Hieracium s. str. is notoriously known for its extreme morphological variability and variation in ploidy levels that is associated with differences in modes of reproduction. Extensive past hybridization is supposed for the subgenus, but recent hybridization was evidenced only in few cases. The subgenus attracts the attention of botanists already for more than a century. Therefore the species diversity is largely examined and the taxonomy of the subgenus is well elaborated, although several contradictory taxonomic concepts exist. However the relationships among the species are unknown and haven't been studied yet. The investigation of these relationships from a phylogenetic perspective using molecular approaches was the main aim of the presented thesis. Basic species (both diploid and polyploid), representing morphologically unique taxa, that are supposed to be the basic evolutionary units of the subgenus were studied. The sequences of two intergenic spacers of the cpDNA (trnT-trnL and trnV-ndhC) and the external transcribed spacer of the nuclear ribosomal DNA (nrDNA ETS) were analyzed. Moreover, three new low-copy nuclear markers with higher variability than nrDNA and cpDNA markers were developed and their suitability for phylogenetic studies in Hieracium s. str. was...
Analysis of antimicrobial peptides in venom glands of bumblebees.
Janechová, Daniela ; Cvačka, Josef (advisor) ; Monincová, Lenka (referee)
The growing resistance of bacteria to traditional antibiotics promotes the interest in finding new substances for their production. Antimicrobial peptides have comparable effect to conventional antibiotics, but a different mechanism of action and they do not provoke bacterial resistance. These peptides were characterized in all forms of multicellular organisms. Hymenoptera venom contains many biologically active substances including antimicrobial peptides. For this reason, this thesis focuses on the acquisition of antimicrobial peptide sequences from selected species of bumblebees (Bombus terrestris, B. hortorum, B. hypnorum, B. pratorum, B. lucorum, B. lapidarius, B. humilis and B. bohemicus). The isolation from the venom glands was performed by high performance liquid chromatography with reversed phases. Subsequent analysis was performed using the methods of mass spectrometry, matrix-assisted laser desorption/ionization with time of flight analyzer and electrospray ionization connected with hybrid linear ion trap analyzer with orbitrap. The sequences for the found peptides were determined by tandem mass spectrometry methods "de novo" and Edman degradation. In this work we characterized 17 sequences of peptides extracted from bumblebee venom glands for which antimicrobial activity was determined...

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