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Reprodukční užitkovost v chovu prasnic
AIDELOMON, Emmanuel Onosimuan
2024 - English
Cílem diplomové práce bylo analyzovat úroveň reprodukční užitkovosti prasnic. Byla shromážděna a analyzována data 1 013 záznamů prasnic (plemene large white a hybridních prasnic plemen large white a landrase) z vybraného chovu za časové období čtyř let (2019 až 2022). Do sledování byly zařazené prasnice na 1. až 7. vrhu, které byly rozdělené do následujících kategorií - 1. a 2. vrh (1); 3. až 5. vrh (2) a 6. a 7. vrh (3). Prasnice byly chované ve stáji s řízeným klimatem, byly očkované podle vakcinačního programu chovu a krmené na základě nutričních požadavků. Voda byla prasnicím dostupná prostřednictvím systému napáječek ad libitum. Byly sledovány vlivy působící na počet všech a živě narozených selat, a to pořadí vrhu, sezóna při prvním zapuštění, genotyp, věk při prvním porodu, délka březosti, délka mezidobí, interval od odstavu do zabřeznutí, rok zapuštění a kanec. Data byla analyzována pomocí softwaru Statistika.12, TIBCO. Statisticky významný vliv (P < 0,05) byl pozorován mezi skupinou 1 (1. a 2. vrh) a skupinou 2 (3. až 5. vrh) pro všechna a živě narozená selata s nejvyšší hodnotou ve skupině 2 (3. až 5. vrh), poté počet selat zaznamenal pokles. Počet všech a živě narozených selat byl zjištěný nejvyšší u prasnic zapuštěných v letních měsících a nejnižší u prasnic zapuštěných na podzim (statisticky nevýznamné rozdíly). Nejvyšší počet všech narozených selat měly prasnice LW L a nejvyšší počet živě narozených selat měly prasnice LW. Statisticky významně nižší počet všech a živě narozených selat měly kříženky L LW. Plodnost prasnic při prvním porodu ve věku 361-381 dní se statisticky významně lišila od prasnic s prvním porodem ve věku < 361 dnů. U prasnic s prvním porodem ve věku > 381 dnů došlo ke snížení počtu všech a živě narozených selat ve srovnání s prasnicemi ve věku 361-381 dní při prvním porodu, ale rozdíl nebyl statisticky významný. Vyšší hodnoty v počtu všech i živě narozených selat byly zaznamenány u prasnic s délkou březosti 114 dnů ve srovnání s prasnicemi s délkou březosti 115 dnů (statisticky nevýznamný vliv). Takže čím vyšší počet selat byl ve vrhu, tím kratší byla délka březosti. Vyšší počet všech i živě narozených selat byl zjištěn u prasnic s délkou mezidobí 146 dnů ve srovnání s prasnicemi s délkou mezidobí 147 dní, ale rozdíl nebyl statisticky významný. Počet všech i živě narozených selat u prasnic s intervalem od odstavu do zapuštění 4 dny se statisticky významně lišil od prasnic s intervalem od odstavu do zapuštění 5 dnů. Nejvyšší počet všech i živě narozených selat byl zaznamenán v roce 2022 a nejnižší počet selat v roce 2019. Počet všech a živě narozených selat v roce 2022 se statisticky významně lišil od počtu selat v letech 2019 a 2020. Závěrem lze konstatovat, že výsledky sledování naznačily, že jako indikátory reprodukční užitkovosti prasnic lze u prasnic použít pořadí vrhu, genotyp, věk při prvním porodu, interval od odstavu do zabřeznutí a kanec. Analýza také poskytla základ pro budoucí vývoj benchmarkingu ke sledování a zlepšování reprodukční užitkovosti ve stádech prasnic. The objective of this study was to analyse the level of reproductive efficiency of sows. Data of 1013 records of sows between 2019 to 2022 from a commercial herd were collected and analysed (Large White and cross between Large White and Landrace sows). Sows ranged from parity 1 to 7 with the number of parity grouped into 1-2 (1); 3-5 (2); 6-7 (3). Sows were raised in well-ventilated pens and were vaccinated according to the veterinarian's recommendations and sows were well-fed to meet their nutritional requirement. Water was available ad libitum via the drinking nipple system. All-born piglets and live-born piglets were analysed by monitoring the influence of parity, season at first conception, genotype, age at first farrowing, gestation length, farrowing interval, weaning-to-conception interval, year of conception and boar. Data were analysed using Statistika.12, TIBCO software package. Significant influence (P < 0.05) was observed between parity group 1 (parity 1-2) and parity group 2 (parity 3-5) for all-born piglets and live-born piglets with the highest value at parity group 2 (parity 3-5) and decreasing thereafter. Prolificacy (all-born piglets and live-born piglets) appeared highest in animals during the summer months and the lowest in autumn (statistically unconfirmed differences). Crossing sows between Large White and Landrace produced the highest number of all-born piglets, and sow Large White produced the highest number of live-born piglets. Crossing sows between Landrace and Large White produced a statistically lower number of piglets. Prolificacy at 361-381 days (age of first farrowing) was significantly different from < 361 days. There was reduction in number of all-born piglets and live-born piglets for above > 381 days when compared to 361-381 but it was not different statistically. Higher value was recorded for gestation length of 114 days compared to 115 days in all-born piglets and live-born piglets (but no significant influence). The mean of all-born piglets and live-born piglets shows that the larger the litter is, the shorter the gestation length becomes. Farrowing interval for 146 days had a high mean value for both all-born piglets and live-born piglets compared to 147 days but no significant influence. Weaning to conception interval for 4 days is significantly different from 5 days in all-live born piglets. The highest average for all-born piglets and live-born piglets was recorded in 2022 and the lowest was recorded in 2019. Result for 2022 was significantly different from 2019 and 2020 results. In conclusion, this study showed that sow parity, genotype, age at first farrowing, weaning to conception interval and boar can be used as indicators of reproductive performance. Furthermore, this study has provided the basis for future development of a benchmarking tool to monitor and improve productivity in sow herds.
Keywords:
všech narozených selat; živě narozených selat; reprodukce; prasnice
Available in the Digital Repository of University of South Bohemia.
Reprodukční užitkovost v chovu prasnic
Cílem diplomové práce bylo analyzovat úroveň reprodukční užitkovosti prasnic. Byla shromážděna a analyzována data 1 013 záznamů prasnic (plemene large white a hybridních prasnic plemen large white a ...
Regenerace smyslových orgánů u raků
KOR, Golara
2024 - English
Anteny jsou u raků důležitým smyslovým orgánem, které mají zásadní roli na jejich přežití, komunikaci a orientaci v prostředí. Jsou vybaveny smyslovými chloupky, které umožňují rakům detekovat různé podněty. Raci mají jedinečnou schopnost regenerovat své anteny. Hemocyty jsou specializované buňky raků a hrají klíčovou roli v jejich imunitním systému a podílejí se na procesu regenerace. Ke studiu morfologie a regenerace smyslových orgánů u raků jsme použili kryo-skenování a transmisní elektronové mikroskopy. V kapitole 2 byla kryo-skenovací elektronová mikroskopie použita k identifikaci potenciálních rozdílů v morfologii anten u šesti různých druhů raků, zahrnujících raka mramorovaného Procambarus virginalis, raka mexického Cambarellus patzcuarensis), raka červeného (Procambarus clarkii), raka signálního (Pacifastacus leniusculus), raka ničivého (Cherax destructor) a raka pruhovaného (Faxonius limosus). Zjistili jsme významné rozdíly mezi šesti druhy raků v poměru délky anteny, délky a šířky segmentu k délce krunýře a počtu segmentů. Zkoumání ultrastrukturálních rysů odhalilo rozdíly ve vzorcích distribuce smyslových chloupků podél anten a morfologii povrchu anten. Rozdílná morfologie anten mezi studovanými druhy pravděpodobně ukazuje na přizpůsobení se specifickým podmínkám jejich příslušných stanovišť. Výsledky dále ukázaly, že kombinace morfologických charakteristik anten nám může pomoci rozlišit různé studované druhy raků. V kapitole 3 bylo pomocí transmisní elektronové mikroskopie zkoumáno ultrastrukturální chování hemocytů během koagulace a fagocytózy v počátečních fázích poranění u raka mramorovaného. Během koagulačního procesu prodělaly hemocyty výrazné transformace v morfologii. Cytoplazmatická granula vykazovala změnu z elektronově hustých na elektronově prostupné formy s postupem koagulace. Bylo pozorováno, že transformované granule obsahují amorfní, pro eletrony prostupný materiál navzájem spojený a uvolňující svůj obsah do extracelulárního prostoru jako součást koagulačního procesu. Kromě toho bylo pozorováno, že obsah jádra také hraje roli během procesu koagulace. Navíc amputace nohy vedla k silné svalové degeneraci a fagocytující hemocyty začaly pohlcovat nekrotické tkáně. Kromě toho jsme pozorovali natrávené zbytky z fagocytovaných nekrotických tkání sloučených do granulí a dalších buněčných složek, čímž se zvýšila granularita hemocytů a změnila se jejich buněčná morfologie. Je však nutno poznamenat, že degranulace hemocytů během koagulace by mohla potenciálně snížit jejich granularitu. Vzhledem k tomu, že morfologické vlastnosti jsou pro klasifikaci hemocytů zcela zásadní, musí být tyto morfologické změny během koagulace a fagocytózy považovány za významné faktory. Degenerovaný materiál uložený uvnitř fagocytárních hemocytů může mít uplatnění v imunologických a regeneračních procesech. V kapitole 4 jsme použili transmisní elektronovou mikroskopii, abychom prozkoumali ultrastrukturální aspekty potenciálního zapojení imunitních buněk do regenerace nervů po amputaci anten raků. Zjištění ukázala, že během regenerace nervů byly přítomny všechny tři formy hemocytů. Nicméně granule v semigranulocytech a granulocytech přispěly především ke vzniku nových organel, jako jsou mitochondrie, Golgiho aparát a nervová vlákna v regenerovaných nervech račích anten. Odhalili jsme transformaci granulí hemocytů na různé organely během procesu regenerace nervů na ultrastrukturální úrovni. Závěrem lze říci, že tyto granule fungují jako kompaktní úložiště adaptabilních materiálů nesených imunitními buňkami, schopných transformace na různé organely během regenerace nervů v račích anten. The antennae are a crucial sensory organ in crayfish that plays vital roles in their survival, communication, and orientation within their environment. They are equipped with sensory hairs that enable crayfish to detect various stimuli. Crayfish possess the unique ability to regenerate their antennae. Hemocytes are specialized cells within crayfish and play a crucial role in their immune system and contribute to the process of regeneration. We applied cryo-scanning and Transmission electron microscopies to study sensory organ morphology and regeneration in crayfish. In Chapter 2, cryo-scanning electron microscopy was used to identify potential differences in antennal morphology in six different crayfish species including marbled crayfish Procambarus virginalis, Mexican dwarf crayfish Cambarellus patzcuarensis, red swamp crayfish Procambarus clarkii, signal crayfish Pacifastacus leniusculus, common yabby Cherax destructor, and spiny-cheek crayfish Faxonius limosus. We observed significant differences among the six crayfish species in the ratios of antenna length, segment length and width to carapace length, and the number of segments. Examination of ultrastructural features unveiled differences in the distribution patterns of sensory hairs along the antenna and the morphology of the antennal surface. The varying morphology of antennae among studied species possibly indicates an adaptation to the specific conditions of their respective habitats. Furthermore, the outcomes demonstrated that a combination of variations in both antennal morphological characteristics and biometric measurements could effectively help us to distinguish the different studied crayfish species. In Chapter 3, the ultrastructural behaviour of hemocytes during coagulation and phagocytosis in the initial phases of injury in marbled crayfish was explored using transmission electron microscopy. During the coagulation process, hemocytes experienced marked transformations in morphology. The cytoplasmic granules exhibited a change from electron-dense to electron-lucent forms with the progress of coagulation. The transformed granules containing amorphous, electron-lucent material were observed to combine and release their contents into the extracellular space as part of the coagulation process. Additionally, it was observed that the nucleus contents also play a role in the coagulation process. Furthermore, the amputation of the leg led to substantial muscle degeneration, and phagocytic hemocytes start to take up the necrotic tissues. Besides, we observed the digested remains from phagocytized necrotic tissues merged into granules and other cellular components, thereby enhancing the granularity of the hemocytes and altering their cellular morphology. However, it is essential to note that hemocyte degranulation during coagulation could potentially reduce their granularity. Since morphological features are critical for classifying hemocytes, these morphological changes during coagulation and phagocytosis must be considered significant factors. The degenerated material that stored inside phagocytic hemocytes may have application in immunological and regeneration processes. In Chapter 4, we employed transmission electron microscopy to explore the ultrastructural aspects of potential immune cell involvement in nerve regeneration within crayfish antennae post-amputation. The findings indicated that, during nerve regeneration, all three forms of hemocytes were present. However, the granules within semi-granulocytes and granulocytes mainly contributed to the generation of new organelles such as mitochondria, the Golgi apparatus, and nerve fibers in the regenerated nerves of crayfish antennae. We revealed the transformation of granules of hemocytes into diverse organelles during the process of nerve regeneration at the ultrastructural level. In conclusion, these granules function as compact repositories of adaptable materials carried by immune cells, capable of transformatio
Keywords:
Anteny; Elektronová mikroskopie; Hemocyt; Imunitní systém; Regenerace
Available in the Digital Repository of University of South Bohemia.
Regenerace smyslových orgánů u raků
Anteny jsou u raků důležitým smyslovým orgánem, které mají zásadní roli na jejich přežití, komunikaci a orientaci v prostředí. Jsou vybaveny smyslovými chloupky, které umožňují rakům detekovat různé ...
God's Unity and God's Relational Character in the Thinking and Biblical Interpretation of Philo Judaeus
LANDOVÁ, Barbora
2024 - English
Diplomová práce analyzuje, jak se helénský židovský filosof, Filón Alexandrijský, vypořádává s pasážemi v Bibli, ve kterých je Bůh antropomorfizován. Práce se snaží představit dva světy uvnitř Filónovy osoby, svět filosofie a Bible, přičemž oba jsou zásadní pro jeho myšlení, ačkoli přináší odlišné podání Boha. Cílem práce je zjistit, jakým způsobem Filón, zastávaje filosofický koncept neměnného Boha, řeší ty pasáže v Bibli, při kterých se zdá, že je Boží charakter proměnlivý. Práce přichází s hypotézou, že vyobrazení Boha je svázáno s literárním žánrem, který Filón použije, když o Bohu mluví. V úvahu jsou vzaty Filónovy tři práce - Quod Deus sit Immutabilis, Quaestiones et Solutiones in Genesin et Exodum a De Vita Mosis, zatímco je rozlišováno mezi jejich odlišnými žánry. The thesis analyzes how the Hellenistic Jewish philosopher Philo of Alexandria deals with passages in the Bible where God experiences any kind of human emotions. It aims to present the two sides of Philo's persona - the Greek and the Jewish. These two worlds (the world of philosophy and that of the Bible) are constituent for Philo's thinking, however, they also provide a distinct rendering of God. The aim is to ascertain how Philo deals with passages in the Bible where God seems to have a changeable character while holding a strong philosophical concept of him. The thesis adheres to the hypothesis that his depiction of God is bound to the literary genre he applies when rendering God. It takes into consideration Philo's Quod Deus sit Immutabilis, Quaestiones et Solutiones in Genesin et Exodum and De Vita Mosis while differentiating between their distinct literary genres.
Keywords:
židovská helénská filosofie; Filón Alexandrijský; židovská filosofie; antropomorfismus; Septuaginta
Available in the Digital Repository of University of South Bohemia.
God's Unity and God's Relational Character in the Thinking and Biblical Interpretation of Philo Judaeus
Diplomová práce analyzuje, jak se helénský židovský filosof, Filón Alexandrijský, vypořádává s pasážemi v Bibli, ve kterých je Bůh antropomorfizován. Práce se snaží představit dva světy uvnitř ...
The study of the phylogeny and taxonomy of selected genera of Erebidae (Lepidoptera; Noctuoidea) as a tool for understanding of origin of the Afrotropical moth fauna
IGNATEV, Nikolai
2024 - English
In this thesis, I conducted the taxonomical and phylogenetical research of selected Afrotropical moth genera, especially an Old-World moth genus Amerila, Walker 1855. All the studied genera belong to the family Erebidae (Lepidoptera; Noctuoidea) and are well-presented in the state European entomological collections. In our research, we used mitochondrial, or mitochondrial and nuclear markers and different molecular analyses to resolve relationships within the studied genera (exclude Meganaclia, Aurivillius 1892). Comparative morphological analysis was used in all the studies. We aimed to update the classification of studied Lepidoptera genera, and to highlight the gaps in taxonomical study of Afrotropical moth fauna in general.
Keywords:
arctiinae; ancestral state reconstruction; integrative taxonomy; morphological characters
Available in the Digital Repository of University of South Bohemia.
The study of the phylogeny and taxonomy of selected genera of Erebidae (Lepidoptera; Noctuoidea) as a tool for understanding of origin of the Afrotropical moth fauna
In this thesis, I conducted the taxonomical and phylogenetical research of selected Afrotropical moth genera, especially an Old-World moth genus Amerila, Walker 1855. All the studied genera belong to ...
Microbial ecology of Alpine and High Arctic soils in changing climate
LULÁKOVÁ, Petra
2024 - English
This study has contributed to a deeper understanding of certain aspects of initial soil development in the extreme environments of the High Arctic and the High Alpine regions. Specifically, we have examined the impact of geochemistry on the initial microbial succession following deglaciation and its subsequent transition toward the predominant influence of pioneer plants over time and the process of SOC stabilization. Our focus has been on understanding substrate-microbial and plant-microbial interactions, particularly with regards to nutrient availability and stoichiometry. In addition to investigations carried out in the High Arctic regions, we conducted an incubation experiment in the High Alps. This experiment aimed to explore nutrient availability for microorganisms in relation to their response to varying high temperatures, which are observed under ongoing climate change. This study has contributed to a deeper understanding of certain aspects of initial soil development in the extreme environments of the High Arctic and the High Alpine regions. Specifically, we have examined the impact of geochemistry on the initial microbial succession following deglaciation and its subsequent transition toward the predominant influence of pioneer plants over time and the process of SOC stabilization. Our focus has been on understanding substrate-microbial and plant-microbial interactions, particularly with regards to nutrient availability and stoichiometry. In addition to investigations carried out in the High Arctic regions, we conducted an incubation experiment in the High Alps. This experiment aimed to explore nutrient availability for microorganisms in relation to their response to varying high temperatures, which are observed under ongoing climate change.
Keywords:
Arctic soils; biogeochemistry; deglaciation; glacier forefield; microbial assembly; soil succession; alpine soils; SOC stabilization; plant-microbial interaction; rhizosphere soils; willow exudation
Available in the Digital Repository of University of South Bohemia.
Microbial ecology of Alpine and High Arctic soils in changing climate
This study has contributed to a deeper understanding of certain aspects of initial soil development in the extreme environments of the High Arctic and the High Alpine regions. Specifically, we have ...
Investigating associations of saproxylic beetles with forest structure through the analysis of species composition and feeding guilds
KOZEL, Petr
2024 - English
The thesis contains studies focusing on various forest biotopes of Central Europe and saproxylic beetles as a model group for forest ecology research. In the review, current knowledge about the threats for forest biota, mainly saproxylic beetles are discussed in the context of species composition and trait-based approach. Various stages of succession in the patches of disturbed forests, their connectivity, the introduction non-native tree species, and the assessment of feeding guilds using stable isotopes are studied in the relation to saproxylic beetles in separate chapters.
Keywords:
connectivity; forest ecology; non-native tree species; trait-based approach; saproxylic beetles; species composition; stable isotopes; succession
Available in the Digital Repository of University of South Bohemia.
Investigating associations of saproxylic beetles with forest structure through the analysis of species composition and feeding guilds
The thesis contains studies focusing on various forest biotopes of Central Europe and saproxylic beetles as a model group for forest ecology research. In the review, current knowledge about the ...
Waste as a source of business opportunities for circular economy and bioeconomy
MAROUŠKOVÁ, Anna
2024 - English
This dissertation thesis underlines the promising potential of biowaste processing using Black Soldier Fly (BSF) larvae with the subsequent production of value-added products such as feed components, fertilizers, cosmetics, etc. The concept is gaining global popularity, although legislative challenges initially hindered EU companies, resulting in delays in the placement of BSF products on the market. Nevertheless, EU enterprises, leveraging the time afforded by evolving legislation, emerged with cutting-edge technologies, positioning them to produce high-quality protein for animal feed and other value-added products. The study reveals a significant correlation between business development and scientific achievements in the field of BSF rearing in the EU and EFTA Member states. Another finding of this study was that countries with established Bioeconomy strategies at the national level show higher numbers of publications and established companies in the field of BSF rearing compared to those with Bioeconomy strategies under development or other bioeconomy-related policies. However, the biggest finding of this study is the results of the BSF meal, soybean meal and fish meal competitiveness analysis for the first time conducted in the Czech Republic. The comprehensive analysis showed that BSF meal has the potential to compete with products like soybean meal and fish meal despite its current market price is still a major drawback. The main benefits of the BSF meal are well-balanced nutritional properties and demonstrated positive ecological impact. It was also discovered that under the current conditions, the key bottlenecks are insufficient BSF products supply and the overly strict EU legislation which causes challenges in the price competitiveness. However, based on the review accompanied by the competitiveness analysis results and taking into account political trends, it can be concluded that industrial insect rearing represents a significant commercial potential. This dissertation thesis underlines the promising potential of biowaste processing using Black Soldier Fly (BSF) larvae with the subsequent production of value-added products such as feed components, fertilizers, cosmetics, etc. The concept is gaining global popularity, although legislative challenges initially hindered EU companies, resulting in delays in the placement of BSF products on the market. Nevertheless, EU enterprises, leveraging the time afforded by evolving legislation, emerged with cutting-edge technologies, positioning them to produce high-quality protein for animal feed and other value-added products. The study reveals a significant correlation between business development and scientific achievements in the field of BSF rearing in the EU and EFTA Member states. Another finding of this study was that countries with established Bioeconomy strategies at the national level show higher numbers of publications and established companies in the field of BSF rearing compared to those with Bioeconomy strategies under development or other bioeconomy-related policies. However, the biggest finding of this study is the results of the BSF meal, soybean meal and fish meal competitiveness analysis for the first time conducted in the Czech Republic. The comprehensive analysis showed that BSF meal has the potential to compete with products like soybean meal and fish meal despite its current market price is still a major drawback. The main benefits of the BSF meal are well-balanced nutritional properties and demonstrated positive ecological impact. It was also discovered that under the current conditions, the key bottlenecks are insufficient BSF products supply and the overly strict EU legislation which causes challenges in the price competitiveness. However, based on the review accompanied by the competitiveness analysis results and taking into account political trends, it can be concluded that industrial insect rearing represents a significant commercial potential.
Keywords:
bioeconomy; circular economy; competitiveness; feed; insect protein
Available in the Digital Repository of University of South Bohemia.
Waste as a source of business opportunities for circular economy and bioeconomy
This dissertation thesis underlines the promising potential of biowaste processing using Black Soldier Fly (BSF) larvae with the subsequent production of value-added products such as feed components, ...
Anthropogenic impact on early-life stages of rheophilic fish
BARTOŇ, Daniel
2024 - English
This study focuses on the problems faced by the early-life stages of fish living in a river influenced by reservoirs and suggests possible solutions to enhance recruitment. The model fish for the study is the asp (Leuciscus aspius), known for its significant and protected population in the Želivka Reservoir, from where it migrates for reproduction to the tributary of Želivka River. The asp migrates upstream in spring to spawn in shallow, fast-flowing waters. At a research site, the adult population of asp is monitored using passive telemetry. Fish are caught, tagged, and released back into the reservoir. The asp population faces threats due to hydropeaking and river fragmentation. Hydropeaking causes egg detachment from the pebbles and their sedimentation in the reservoir. The study suggests that water should not exceed a velocity of 0.7 m×s-1 at the spawning ground. Periodically increasing discharge also shifts spawning fish outside their preferred spawning site, causing disruption of spawning and potentially lowering recruitment. A flowdeflector was built to protect newly spawned eggs from hydropeaking. However, there are additional threats to the asp recruitment process such as egg consumption by non-indigenous fish like common bream (Abramis brama). Water flow conditions are crucial for the conservation of rheophilic fish, as these fish, aside from habitat loss and modification, also face newly interacting generalist fish species moving from lentic to lotic sections of the system. Fish communities can be affected by reservoir construction far upstream, and these anthropogenic habitat alterations have severe negative impacts on threatened rheophilic fish recruitment. This study focuses on the problems faced by the early-life stages of fish living in a river influenced by reservoirs and suggests possible solutions to enhance recruitment. The model fish for the study is the asp (Leuciscus aspius), known for its significant and protected population in the Želivka Reservoir, from where it migrates for reproduction to the tributary of Želivka River. The asp migrates upstream in spring to spawn in shallow, fast-flowing waters. At a research site, the adult population of asp is monitored using passive telemetry. Fish are caught, tagged, and released back into the reservoir. The asp population faces threats due to hydropeaking and river fragmentation. Hydropeaking causes egg detachment from the pebbles and their sedimentation in the reservoir. The study suggests that water should not exceed a velocity of 0.7 m×s-1 at the spawning ground. Periodically increasing discharge also shifts spawning fish outside their preferred spawning site, causing disruption of spawning and potentially lowering recruitment. A flowdeflector was built to protect newly spawned eggs from hydropeaking. However, there are additional threats to the asp recruitment process such as egg consumption by non-indigenous fish like common bream (Abramis brama). Water flow conditions are crucial for the conservation of rheophilic fish, as these fish, aside from habitat loss and modification, also face newly interacting generalist fish species moving from lentic to lotic sections of the system. Fish communities can be affected by reservoir construction far upstream, and these anthropogenic habitat alterations have severe negative impacts on threatened rheophilic fish recruitment.
Available in the Digital Repository of University of South Bohemia.
Anthropogenic impact on early-life stages of rheophilic fish
This study focuses on the problems faced by the early-life stages of fish living in a river influenced by reservoirs and suggests possible solutions to enhance recruitment. The model fish for the ...
A novel structurally characterized haloacid dehalogenase superfamily phosphatase from Thermococcus thioreducens with diverse substrate specificity
HAVLÍČKOVÁ, Petra
2024 - English
This RNDr. thesis is focused on complex studies of a haloacid dehalogenase superfamily phosphatase member with an unknown substrate specificity, isolated from a hyperthermofilic archeon Thermococcus thioreducens. The HAD phosphatase, internally named as Tt82, was isolated, expressed and purified using standard techniques and the crystal structure was solved by X-ray crystallography method. The refined crystal structure displayed characteristic HAD superfamily elements, such as the HAD canonical fold with the HAD signature motifs in the active site. Further, possible substrates for the enzyme were proposed and examined by computational docking in the active site of the HAD phosphatase. The results of the docking studies served as a basis for an experimental measurement of Tt82 enzymatic activity against selected substrates at two different temperatures. HAD phosphatase Tt82 is a promising target for the biotechnological field, mainly for its wide substrate specificity and higher temperature optima.
Available in the Digital Repository of University of South Bohemia.
A novel structurally characterized haloacid dehalogenase superfamily phosphatase from Thermococcus thioreducens with diverse substrate specificity
This RNDr. thesis is focused on complex studies of a haloacid dehalogenase superfamily phosphatase member with an unknown substrate specificity, isolated from a hyperthermofilic archeon Thermococcus ...
Functional Ultrastructure of Hymenopteran Stingers: Devastating Spear or Delicate Syringe
ČERNÝ, Jan
2024 - English
In this study, we tested the hypothesis that a micro-serrated edge on the honey bee Apis mellifera stinger tip serves as a tool for more intensive crushing of cell membranes in the victim's tissues. This could have mechanical consequences as well as initiate metabolic pathways linked to cell membrane breakdown (e.g., production of biogenic amines). Accordingly, we found that hymenopteran species that use their stingers as an offensive or defensive weapon to do as much damage to the victim's body as possible had this cuticular microstructure. In parasitic hymenopterans, on the other hand, this structure was missing, as stingers are solely used to delicately transport venom to the victim's body in order to do little mechanical harm. We also demonstrated that the stinger lancets of the honey bee A. mellifera are living organs with sensilla innervated by sensory neurons and containing other essential tissues, rather than mere cuticular structures.
Keywords:
bee; Hymenoptera; nerve; SEM; sensilla; stinger microstructure; TEM; ultrastructure
Available in the Digital Repository of University of South Bohemia.
Functional Ultrastructure of Hymenopteran Stingers: Devastating Spear or Delicate Syringe
In this study, we tested the hypothesis that a micro-serrated edge on the honey bee Apis mellifera stinger tip serves as a tool for more intensive crushing of cell membranes in the victim's tissues. ...
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