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Thin Nanostructured Film with Bioapplication Potential
KUMAR, Sanjay
2024 - anglický
The Ph.D. thesis aims to investigate, develop, and fabricate advanced nanostructured surfaces for (bio)sensors and detection applications. The primary outcome of the research is the development of a functional sensor transducer for the detection of specific anti-DbpA antibodies, typically produced by a living organism in response to Lyme disease infection, as well as for detecting live Borreliosis pathogens. The developed sensor is based on AgNPs/C:H:N:O plasma polymer nanocomposites. Silver (Ag) nanoparticles, generated by a gas aggregation source, are incorporated into a C:H:N:O plasma polymer matrix, which is deposited by magnetron sputtering of nylon 6.6. The surface of the AgNPs/C:H:N:O nanocomposite is functionalized with amino-rich -NH2 grafts and specific antibodies to achieve high specificity in detection. Anchored Ag nanoparticles propagate localized surface plasmon resonance (LSPR), optically responding to changes caused by immobilized targets near the nanoparticles. The sensitivity of the sensor transducer is enhanced by incorporating Cu nanoparticles, which contribute to Cu-Ag coupling modes responsible for the modulation of the LSPR bands. The achieved results pave the way for rapid, low-cost, sensitive platforms for detecting not only the antibodies/pathogens studied here but also potentially other targets. The Ph.D. thesis aims to investigate, develop, and fabricate advanced nanostructured surfaces for (bio)sensors and detection applications. The primary outcome of the research is the development of a functional sensor transducer for the detection of specific anti-DbpA antibodies, typically produced by a living organism in response to Lyme disease infection, as well as for detecting live Borreliosis pathogens. The developed sensor is based on AgNPs/C:H:N:O plasma polymer nanocomposites. Silver (Ag) nanoparticles, generated by a gas aggregation source, are incorporated into a C:H:N:O plasma polymer matrix, which is deposited by magnetron sputtering of nylon 6.6. The surface of the AgNPs/C:H:N:O nanocomposite is functionalized with amino-rich -NH2 grafts and specific antibodies to achieve high specificity in detection. Anchored Ag nanoparticles propagate localized surface plasmon resonance (LSPR), optically responding to changes caused by immobilized targets near the nanoparticles. The sensitivity of the sensor transducer is enhanced by incorporating Cu nanoparticles, which contribute to Cu-Ag coupling modes responsible for the modulation of the LSPR bands. The achieved results pave the way for rapid, low-cost, sensitive platforms for detecting not only the antibodies/pathogens studied here but also potentially other targets.
Klíčová slova:
plasma polymer; plasma polymerization; C:H:N:O thin film; nylon; nanoparticles (Ag; Cu); nanostructures; nanocomposite; surface functionalization; magnetron sputtering; annealing; adhesion; immobilization; sensors; antibacterial; Lyme disease; Borrelia; plasmonic absorption; localized surface plasmon resonance (LSPR); plasma-assisted deposition; enhanced detection
Plné texty jsou dostupné v digitálním repozitáři JČU.
Thin Nanostructured Film with Bioapplication Potential
The Ph.D. thesis aims to investigate, develop, and fabricate advanced nanostructured surfaces for (bio)sensors and detection applications. The primary outcome of the research is the development of a ...
Population genomics of parasite adaptation: New insights into diversification and speciation of parasites
NAZARIZADEH DEHKORDI, Masoud
2024 - anglický
This thesis investigates the ecological and genetic dynamics of parasitic species, primarily focusing on Ligula intestinalis tapeworms and Cimex bedbugs, aiming to enhance our understanding of their evolutionary biology, genetics, and adaptation mechanisms. In Chapter I, it elucidates the prevalence and population genetic structure of L. intestinalis plerocercoids in various cyprinoid fish species across Czech water bodies, focusing on how different hosts and environments influence genetic diversity and distribution. Chapter II explores the historical dispersal and host-switching events that have shaped the evolutionary history of the L. intestinalis species complex on a global scale. This includes identifying major evolutionary lineages, their host specificity, and the influence of biogeographic and demographic events on lineage diversity. Chapter III provides a highly contiguous genome assembly for L. intestinalis and examines RNA transcription patterns to understand the regulation of biological functions during its life cycle, establishing a comprehensive reference transcriptome for both plerocercoid and adult stages. Chapter IV explores the mechanisms underlying possible ecological speciation in L. intestinalis, particularly under a sympatric setting, to determine whether host specificity influences population structure in the absence of geographical separation. Chapter V shifts focus to the establishment of the tropical bedbug, Cimex hemipterus, in Central Europe, using genetic analyses to reveal limited mtDNA variability and the presence of pyrethroid resistance mutations. Finally, Chapter VI investigates genetic and transcriptomic divergence in C. lectularius populations associated with human and bat hosts, exploring how host switching influences genetic diversity and adaptation. This genomic and transcriptomic approach provides valuable insights into the evolutionary dynamics and adaptive strategies of parasitic species.
Klíčová slova:
Population genomics; Phylogeography; Historical biogeography; Ligula intestinalis; bedbugs
Plné texty jsou dostupné v digitálním repozitáři JČU.
Population genomics of parasite adaptation: New insights into diversification and speciation of parasites
This thesis investigates the ecological and genetic dynamics of parasitic species, primarily focusing on Ligula intestinalis tapeworms and Cimex bedbugs, aiming to enhance our understanding of their ...
Tuning carotenoid photophysics by changes in structure and local environment
ÖZCAN, Emrah
2024 - anglický
This thesis investigates the complex dynamics of excited states in carotenoids, focusing on the origins and properties of certain dark states and how they are affected by external disturbances such as metal interactions, pH changes, applied voltage, and chemical modifications. Paper I demonstrates the creation of stable astaxanthin-metal complexes and their altered excited-state dynamics, revealing shortened lifetimes and enhanced ICT bands due to metal-ion interactions. Paper II explores the effect of external voltage on 8-apo--carotenal, showing that applied voltage can control the ICT state amplitude and extend its lifetime. Paper III examines pH-dependent effects on crocin, finding significant pH-induced shifts and stabilization at basic pH levels. Paper IV presents the synthesis and analysis of bis-phenylhydrazone astaxanthin, highlighting its modified excited-state dynamics and the potential for organic modification to study new effects. These findings enhance our understanding of carotenoid excited states and suggest new research approaches. This thesis investigates the complex dynamics of excited states in carotenoids, focusing on the origins and properties of certain dark states and how they are affected by external disturbances such as metal interactions, pH changes, applied voltage, and chemical modifications. Paper I demonstrates the creation of stable astaxanthin-metal complexes and their altered excited-state dynamics, revealing shortened lifetimes and enhanced ICT bands due to metal-ion interactions. Paper II explores the effect of external voltage on 8-apo--carotenal, showing that applied voltage can control the ICT state amplitude and extend its lifetime. Paper III examines pH-dependent effects on crocin, finding significant pH-induced shifts and stabilization at basic pH levels. Paper IV presents the synthesis and analysis of bis-phenylhydrazone astaxanthin, highlighting its modified excited-state dynamics and the potential for organic modification to study new effects. These findings enhance our understanding of carotenoid excited states and suggest new research approaches.
Klíčová slova:
Carotenoids; Metal complexes; Ultrafast spectroscopy; Charge transfer state; Cyclic voltammetry; 8'-apo--carotenal; Spectroelectrochemistry; Crocin; pH-dependence.
Plné texty jsou dostupné v digitálním repozitáři JČU.
Tuning carotenoid photophysics by changes in structure and local environment
This thesis investigates the complex dynamics of excited states in carotenoids, focusing on the origins and properties of certain dark states and how they are affected by external disturbances such as ...
Consumptive and non-consumptive effect of predators and food quality on arthropod herbivores
KOLLROSS, Jan
2024 - anglický
Top-down and bottom-up controls are crucial mechanisms that shape ecosystems and biodiversity. In this thesis, I investigate both bottom-up and top-down forces, their interplay and specific effects on arthropod communities, herbivores, and their behaviour across vertical forest gradients. The thesis consists of four chapters. The first chapter explores the top-down regulation of arthropods and the resulting herbivore damage across a vertical forest gradient in a Japanese temperate forest, focusing on the effect of three groups of insectivorous predators. In my second chapter, I attempt to compare the relative impact of bottom-up and top-down control. I studied their relative effects on arthropods and herbivore damage by manipulating nutrient availability and access of predators to trees in a temperate forest in the Czech Republic. In my third chapter, I focused on one of the most important insect orders, the Coleoptera. I investigated the Coleoptera communities and the influence of predators on them along the vertical forest gradient in two different temperate sites: in Japan and Germany. Finally, I examined the nonlethal effect of predators on herbivore prey, testing the effect of bird presence on locust behavior and their stress hormone levels. Overall, my thesis examines the complexity of tri-trophic interactions between plants, herbivorous arthropods, and their insectivorous predators. It highlights the importance of nutrient availability, and the access of insectivorous predators to plants, for the functioning and result of multi-trophic interactions. It also discusses lethal as well as nonlethal effects separately. Top-down and bottom-up controls are crucial mechanisms that shape ecosystems and biodiversity. In this thesis, I investigate both bottom-up and top-down forces, their interplay and specific effects on arthropod communities, herbivores, and their behaviour across vertical forest gradients. The thesis consists of four chapters. The first chapter explores the top-down regulation of arthropods and the resulting herbivore damage across a vertical forest gradient in a Japanese temperate forest, focusing on the effect of three groups of insectivorous predators. In my second chapter, I attempt to compare the relative impact of bottom-up and top-down control. I studied their relative effects on arthropods and herbivore damage by manipulating nutrient availability and access of predators to trees in a temperate forest in the Czech Republic. In my third chapter, I focused on one of the most important insect orders, the Coleoptera. I investigated the Coleoptera communities and the influence of predators on them along the vertical forest gradient in two different temperate sites: in Japan and Germany. Finally, I examined the nonlethal effect of predators on herbivore prey, testing the effect of bird presence on locust behavior and their stress hormone levels. Overall, my thesis examines the complexity of tri-trophic interactions between plants, herbivorous arthropods, and their insectivorous predators. It highlights the importance of nutrient availability, and the access of insectivorous predators to plants, for the functioning and result of multi-trophic interactions. It also discusses lethal as well as nonlethal effects separately.
Klíčová slova:
Bottom-up control; top-down control; arthropod communities; herbivory; vertical forest gradient; nutrient availability; predator presence; trophic cascades; ecosystem dynamics; nonlethal predator effects; Coleoptera; temperate forests
Plné texty jsou dostupné v digitálním repozitáři JČU.
Consumptive and non-consumptive effect of predators and food quality on arthropod herbivores
Top-down and bottom-up controls are crucial mechanisms that shape ecosystems and biodiversity. In this thesis, I investigate both bottom-up and top-down forces, their interplay and specific effects on ...
Impact of water deficit stress on leaf quality, predator and herbivore communities in Ficuses
XIAO, Xue
2024 - anglický
This thesis addresses the mechanism by which drought affects tropical plant-insect interactions via leaf traits, focusing on Ficus species. I discovered that both drought intensity and duration indirectly influenced the leaf palatability of Ficus through changes in leaf mechanical traits such as leaf water content and specific leaf area. Furthermore, my research revealed that drought increased leaf herbivory by altering leaf latex outflow, without affecting insect communities. Additionally, I observed that drought enhanced Ficus indirect defense through changes in herbivore-induced plant volatiles. My findings suggest that the impact of drought on Ficus-insect interactions may vary between greenhouse and tropical rainforest environments and may be species-specific. This work underscores the importance and urgency of researching tropical plant-insect interactions under climate change.
Klíčová slova:
drought; herbivores; leaf mechanical traits; leaf secondary metabolites; leaf volatile; predators; tropical ecosystem
Plné texty jsou dostupné v digitálním repozitáři JČU.
Impact of water deficit stress on leaf quality, predator and herbivore communities in Ficuses
This thesis addresses the mechanism by which drought affects tropical plant-insect interactions via leaf traits, focusing on Ficus species. I discovered that both drought intensity and duration ...
Patrnosti v polinačních systémech podél geografických gradientů
JACKWERTH, Karolína
2024 - anglický
The general aim of the thesis is to shed light on invertebrate herbivory and pollination in relation to the changing environment. Several experiments were conducted on meadow communities in the temperate region, and we combined manipulative and experimental approaches during data collection. The first chapter of the thesis investigated the change of invertebrate herbivory across one season affected by phylogeny and plant functional traits. The second chapter emphasized the impact of range-shifting plants, driven by increasing temperature as a proxy for global warming, on herbivory damage. Similarly, the third chapter focused on plant-pollinator turnover on range-shifting plants, driven by increasing temperature as a proxy for global warming. The last fourth chapter examined the effect of increasing temperature as a proxy for global warming on pollen viability of widespread forb.
Klíčová slova:
invertebrate herbivory; insect pollination; range-shifting plants; elevation
Plné texty jsou dostupné v digitálním repozitáři JČU.
Patrnosti v polinačních systémech podél geografických gradientů
The general aim of the thesis is to shed light on invertebrate herbivory and pollination in relation to the changing environment. Several experiments were conducted on meadow communities in the ...
Enhancement of fish communities, improvement of sampling and stock assessment in lakes and reservoirs.
RIBEIRO DE MORAES, Karlos
2024 - anglický
This Ph.D. thesis focuses on fish habitats, how we can improve their natural complexity, and how we can improve techniques to survey these habitats. With increasing human activities affecting freshwater ecosystems due to human population growth and industrial expansion, it is crucial to study environmental changes, their impacts, and ways to mitigate damage. As many biotic and abiotic factors can influence the health and diversity of the community, for our study, we focused on habitat definition and complexity, and the effect of fishery management. Paper (I) focuses on the transition between littoral (shallow areas) and pelagic (open water) habitats and their impact on fish communities. The littoral zone, typically the most intricate segment of a water body, serves as the primary habitat for a significant portion of the fish community and species diversity. However, its spatial extent is very limited. Littoral delimitation is important for obtaining a true picture of the fish community composition and for its sustainable management decisions. Paper (II) investigated the impact of protected areas on fish populations in the Lipno reservoir in the Czech Republic, specifically focusing on the abundance, biomass, standard length, and diversity indices. Protected areas have legislation that reduces or stops certain anthropological impacts to help recover the ecosystem. These areas are normally linked to spawning areas, feeding grounds, or rare species and are vital for the restoration and proliferation of specific environments. In our case, we revealed more and larger predatory fish in protected and low anthropological impact areas. Paper (III) tests the introduction of artificial habitats, which are man-made structures or environments created to provide additional habitats and support for various organisms. Despite efforts to restore habitats to their natural states, there are instances where complete restoration is challenging. In particular, water bodies are subjected to significant anthropogenic alterations, such as reservoirs. In such instances, the introduction of artificial habitats has emerged as a solution to rapidly enhance the complexity of these environments. In Lipno reservoir, artificial floating islands attracted young-of-the-year of common species.
Klíčová slova:
Fish management; Anthropogenic impact; Spatial distribution; Habitat use; Habitat restoration; Stock enhancement; Protected areas; Artificial Habitat
Plné texty jsou dostupné v digitálním repozitáři JČU.
Enhancement of fish communities, improvement of sampling and stock assessment in lakes and reservoirs.
This Ph.D. thesis focuses on fish habitats, how we can improve their natural complexity, and how we can improve techniques to survey these habitats. With increasing human activities affecting ...
The role of ecological gradients and host-parasitoid interaction in tropical insect communities
FINNIE, Sam Cameron
2024 - anglický
The thesis explores the various biotic and abiotic factors that drive change in insect communities with particular emphasis on host-parasitoid interactions. These factors range from ecological gradients to defensive traits and host specialisation. The aim of the first chapter was to determine how the assemblage of an ecologically and anthropocentrically significant group of insects changed in response to altitude. This study highlighted the elevational limit of fruit flies and discovered that a new and promising attractant lure used in agriculture was particularly useful at higher altitudes, potentially opening new avenues for pest management in mountainous regions. The aim of the second chapter was to ascertain the physiological and phylogenetic traits of galling insects that alter the diversity and host specificity of their parasitioids. This research not only uncovered a remarkably specialist community of gall parasitoids, and found significant physiological drivers of parasitoid assemblage, it also broached the possibility of a latitudinal gradient in gall parasitoid host specificity, that warrants further exploration due to its potential implications for biodiversity patterns. The final chapter, aimed to uncover patterns in the vertical stratification of a caterpillar-parasitoid community, and whether any potential patterns and interactions are driven by the defensive traits of the caterpillar hosts. This study provided further evidence that the defensive traits of caterpillars influence their vulnerability to parasitism, and discovered distinct patterns in the vertical stratification of caterpillar communities. Overall, this holistic research expands upon the existing literature on tropical insect ecology and advances our understanding on the complex interactions between insects and their environment. The thesis explores the various biotic and abiotic factors that drive change in insect communities with particular emphasis on host-parasitoid interactions. These factors range from ecological gradients to defensive traits and host specialisation. The aim of the first chapter was to determine how the assemblage of an ecologically and anthropocentrically significant group of insects changed in response to altitude. This study highlighted the elevational limit of fruit flies and discovered that a new and promising attractant lure used in agriculture was particularly useful at higher altitudes, potentially opening new avenues for pest management in mountainous regions. The aim of the second chapter was to ascertain the physiological and phylogenetic traits of galling insects that alter the diversity and host specificity of their parasitioids. This research not only uncovered a remarkably specialist community of gall parasitoids, and found significant physiological drivers of parasitoid assemblage, it also broached the possibility of a latitudinal gradient in gall parasitoid host specificity, that warrants further exploration due to its potential implications for biodiversity patterns. The final chapter, aimed to uncover patterns in the vertical stratification of a caterpillar-parasitoid community, and whether any potential patterns and interactions are driven by the defensive traits of the caterpillar hosts. This study provided further evidence that the defensive traits of caterpillars influence their vulnerability to parasitism, and discovered distinct patterns in the vertical stratification of caterpillar communities. Overall, this holistic research expands upon the existing literature on tropical insect ecology and advances our understanding on the complex interactions between insects and their environment.
Klíčová slova:
Vertical stratification; elevational gradient; defensive traits; caterpillars; galls; tephritidea; parasitism rates; parasitoid richness
Plné texty jsou dostupné v digitálním repozitáři JČU.
The role of ecological gradients and host-parasitoid interaction in tropical insect communities
The thesis explores the various biotic and abiotic factors that drive change in insect communities with particular emphasis on host-parasitoid interactions. These factors range from ecological ...
Reverse Janzen-Connell effects in New Guinean ant-plants
ZAHRA, Shafia
2024 - anglický
In this thesis, I investigate the presence of reverse Janzen-Connell effects in ant-plant communities in Papua New Guinea. Janzen-Connell effects help to explain species diversity maintenance by focusing on natural enemies' role in controlling plant distributions. It is postulated that spillover of enemies near adult plants reduces seedling survival, promoting coexistence and diversity. Conversely, reverse Janzen-Connell effects occur when mutualists enhance survival near conspecific adults, potentially creating larger recruitment zones leading in the extreme to species monodominance. I use a combination of observation and ant exclusion experiments, as well as spatial analysis to explore reverse Janzen-Connell effects. Ant-plant interactions, particularly myrmecophytic ones, show moderate species specificity, a key assumption of classic Janzen-Connell effects. Mutualistic ants enhance plant viability by eliminating herbivores and pathogens, reducing damage, and optimizing photosynthesis. I also explore the specificity of myrmecophytic systems compared to other ant-plant interactions across environments using a data collation approach. I speculate that reverse Janzen-Connell effects can be observed in ant-plant mutualisms, ectomycorrhizal fungi, and plants. I also found through a global meta-analysis that myrmecophytic networks are the most specialized, with specialisation being driven by network type rather than environmental factors. Thus, myrmecophytes are a suitable system to explore the presence of reverse Janzen-Connell effects. Spatial analysis showed the presence of reverse Janzen-Connell effects in plants in seedlings of Meliaceae family and less strongly in adults. In the ant exclusion experiments, conspecific saplings exhibited higher survival and growth, but this was not related to the treatment itself meaning the plants are potentially benefiting from root fungi from adult conspecifics. Saplings with ant patrolling had better survival, although caution is needed due to small sample size. Lastly, I found that ant inhabitation positively influenced growth in older ant-plants, but this was not linked to local ant-plant density, and leaf loss from herbivory was lower when saplings were near adult conspecifics, possibly due to protective volatiles. Taken together this suggests some weak evidence for reverse JanzenConnell effects in the lowland rainforest of Papua New Guinea.
Klíčová slova:
Ant-plants interaction; Papua New Guinea; Rypasora amplifolia; network specialization; Janzen-Connell effect; Reverse Janzen Connell effect; meta-analysis; Myrmecophytic.
Plné texty jsou dostupné v digitálním repozitáři JČU.
Reverse Janzen-Connell effects in New Guinean ant-plants
In this thesis, I investigate the presence of reverse Janzen-Connell effects in ant-plant communities in Papua New Guinea. Janzen-Connell effects help to explain species diversity maintenance by ...
Struktura a funkce rostlinné kutikuly ve vztahu k zásobení listu oxidem uhličitým
JANOVÁ, Jitka
2024 - anglický
V této práci nebyla rostlinná kutikula považována pouze za ochrannou bariéru proti ztrátě vody, ale za dynamickou strukturu, která odráží podmínky prostředí a může nést informace o koncentraci CO2 a jejího gradientu v listu. Pomocí izotopového složení epikutikulárního vosku jsme určili koncentraci CO2 v chloroplastech a gradient CO2 napříč listem hypo- a amfistomatických rostlin, otestovali jsme tento nový model na listech s odlišnou anatomickou strukturou a popsali dynamiku obnovy epikutikulárních vosků mladých a dospělých listů. In this thesis, plant cuticle was not considered only as a protective barrier agains water loss, but as a dynamic structure that reflects environmental conditions and may carry a trace of CO2 concentration and its gradient within the leaf. We used the isotopic composition of epicuticular wax to reveal concentration of CO2 in chloroplasts and gradient of CO2 across the leaf of hypo- and amphistomatous plants, tested this new model in leaves with distinct anatomical structures and described the dynamics of epicuticular wax renewal in young and mature leaves.
Klíčová slova:
izotopy uhlíku; difúze CO2; vývoj kutikuly; epikutikulární vosky; výměna plynů; anatomie listů; listová kutikula; listový mezofyl; mezofylová vodivost; regenerace vosků
Plné texty jsou dostupné v digitálním repozitáři JČU.
Struktura a funkce rostlinné kutikuly ve vztahu k zásobení listu oxidem uhličitým
V této práci nebyla rostlinná kutikula považována pouze za ochrannou bariéru proti ztrátě vody, ale za dynamickou strukturu, která odráží podmínky prostředí a může nést informace o koncentraci CO2 a ...
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