Spelling suggestions: "subject:"testat""
11 |
Holocene sea-level changes in the Falkland Islands : new insights into accelerated sea-level rise in the 20th CenturyNewton, Thomas Lee January 2017 (has links)
This thesis investigates sea-level changes in order to test the hypothesis that the main contribution to early 20th century sea-level rise was Northern Hemisphere land-based ice melt. Multiproxy sea-level reconstructions were established for the Falkland Islands, a location where models suggest sea-level rise from Northern Hemisphere ice melt produces the largest signal. The Falklands reconstruction indicated sea levels in the early 20th century accelerated compared to the long-term rate, synchronous with accelerations observed globally. The magnitude of the acceleration in the Falklands reconstruction was greater than Northern Hemisphere rates, consistent with the spatial pattern from a Northern Hemisphere melt source, but likely less than in New Zealand and Australia. It is therefore not possible rule out other contributions to the observed sea-level acceleration. The Falklands reconstruction indicated a rapid sea-level jump around 8.4 ka BP, synchronous with a jump observed in the Northern Hemisphere, which has been attributed to the sudden drainage of Laurentide proglacial lake Agassiz-Ojibway associated with the 8.2 ka BP climatic downturn. A maximum estimate of 0.89 ± 0.22 m for this jump in the Falklands is considerably less than estimates from Northern Hemisphere records. This difference could indicate additional contributions from the Southern Hemisphere are being recorded in the Northern Hemisphere signal. This thesis also focused on developing testate amoebae as sea-level indicators. In the Falklands, testate amoebae transfer functions were able to reconstruct sea level with precision (±0.08 m) comparable to diatoms (±0.07 m). However, preservation issues were indicated in the fossil testate amoebae assemblages which limits their use as tools for sea-level reconstruction. In addition, contemporary distributions of salt-marsh testate amoebae were investigated over one annual cycle. Seasonal variations in the live assemblages were observed to be asynchronous between taxa. Variations in the death assemblages were also observed which were correlated with variations in the live assemblages. This observation suggests the commonly applied assumption in palaeoenvironmental studies that analysing the death population negates temporal bias is invalid. Further research is required to investigate the impact these observed variations have on reconstructive performance.
|
12 |
Micropaleontological (Foraminifera, Testate Amoeba) and µXRF Analysis of the Upper Cretaceous (Turonian) Notom Delta, Ferron Sandstone Member, Mancos Shale Formation, Central Utah, USATurkistani, Majed January 2020 (has links)
In this thesis, the results of microfossil, biofacies, and geochemical analyses (µXRF) of the Upper Cretaceous (Turonian) Ferron – Notom delta, Utah, USA are reported and discussed. The Notom delta is the oldest of three clastic deltas in the Ferron Sandstone Member, Mancos Shale Formation. Foraminifera and testate amoebae were recovered from ninety-eight mudstone samples among five well-exposed outcrops (Caineville North, Steamboat, Blue Hills, Neilson Wash, and Coalmine Wash). Detailed observations showed foraminifera, and testate amoebae tests have undergone post-burial compression (flattening), dissolution, and transport/reworking; therefore, identification of these assemblages to their species level is difficult.
The micropaleontological analysis of the Ferron-Notom delta consists of three studies. Morphogroup analysis was applied on foraminifera and testate amoebae, where a relationship between the test morphology and habitat was established. Morphogroup analysis resulted in four main morphogroups and eleven morphotypes and were assigned to life mode, environment, and feeding strategies. Three foraminifera morphogroups and one testate amoebae morphogroup were established indicate a range of environments, from shallow shelf to shallow shelf to lagoon/estuary environments. Biofacies analysis using the morphotypes was applied on three outcrops (Caineville North, Steamboat, and Blue Hills). We use the morphotypes to define the four main biofacies using cluster analysis, and biodiversity indices. Four biofacies showed marine and fluvial (freshwater) influences. Salinity and OM indices were derived from the relationship of foraminifera morphotypes (BiS, TrS, TS) and testate amoebae morphotypes (Ta-F, Ta-D, Ta-S) that follows lithofacies trends. Because of the under-representation of calcareous foraminifera (due to taphonomic and/or diagenetic factors), the biodiversity indices are treated herein as relative measures. Despite this taphonomic bias, the agglutinated foraminifera and testate amoebae morphogroups show trends with salinity both among the outcrops and stratigraphically within the outcrops. The Blue Hills outcrop represents the most landward and lowest salinity environment (tidally-influenced backwater), Steamboat is more coast proximal with a higher salinity of the delta front and fluvial estuarine environments, and the Caineville North outcrop represents the most coast proximal (fluvial/estuarine to deltaic/prodeltaic) with salinities ranging from low to medium. It appears that the landward transport and coastward of tests was a significant source of taphonomic bias. Nonetheless, the assemblages provide useful depositional information that correlates with previously documented lithofacies data. A salinity index based on a ratio of trochospiral taxa versus testate amoebae was found to provide a useful measure of coastal proximity that matches lithofacies trends.
The µXRF analysis was conducted on twenty-nine mudstone samples from the Caineville North outcrop to examine elemental proxies for paleo-salinity (Sr/Ba), organic matter (K/S), redox (V/Ni), and sediment sources (Zr/Rb, Ti/Fe, Ti/Ca). Twenty-nine surface mudstone samples collected from four lithofacies representing prodelta, delta front, fluvial valley fill and shelf environments. Fourteen elements (Ti, Fe, Ca, Sr, Ba, Ni, Rb, Zr, S, V, Cu, Mn, Si, and K) were used to calculate proxy ratios to detect variations in terrigenous sediments, carbonate production, salinity, grain size, and fluvial inputs in the Caineville North outcrop. Elemental data showed good correspondence between the elemental data and the lithofacies and microfossil indices. Sr/Ba and Ca/Fe showed relationships with carbonate content and proximity to the shoreline. The paleo-salinity proxy (Sr/Ba) did not respond to salinity, but was more responsive to lithological change of carbonate content. The microfossil salinity index seems to be a more accurate paleo-salinity indicator. The proxy for fluvial input of sediment (Zr/Rb and Ti/Fe) agree well with the lithofacies trends, and Zr/Rb and Ti/Fe showed highest values within the fluvial valley fill facies, with higher variability of Ti/Fe compared to the other lithofacies (prodelta, delta front, and shelf), corresponding to response to the proximity of the depositional sites to a fluvial sediment source. The redox proxy V/Ni matched the previously derived microfossil OM index ("bolivind-type" taxa) showing a strong relationship between eutrophication and redox trends. The study aims to establish important baseline geochemical compositions of sediment sources to establish patterns and trends with sediment succession in the deeper basin (offshore; i.e. Mancos Shale). Potentially, these nearshore to fluvial trends will provide important geochemical data to assess changes in paleoclimate, and sea-level in offshore sediment successions. / Dissertation / Doctor of Philosophy (PhD)
|
13 |
Water depth and salinity control of Thecamoebian (testate amoebae) assemblages in Cootes Paradise, Southern Ontario, Canada.Salimi, Samira 04 1900 (has links)
<p>High density sampling (n=50) was conducted in Cootes Paradise, a shallow wetland on the western shoreline of Lake Ontario near the city of Hamilton. Cootes Paradise is an urban wetland that has been affected by pollutants and nutrients and invasive carp. Thecamoebian analyses paired with site specific environmental measurements (depth, sp. conductivity, temperature, DO and pH) and substrate characteristics (textural and organic content -LOI) show relationships (R<sup>2</sup> = 0.6) with depth (0-1m) and corresponding sp. conductivity (0.5 to 0.65 mS/cm) and temperature (26.5 to 30.5 °C). Q-mode cluster analysis recognized two biofacies. Biofacies 1 samples (n= 26) are found in the deeper areas (0.70 ± 0.27 m) and dominated by <em>C. tricuspis</em> 36 ± 8% (1 std), <em>L. vas</em> 18 ± 13% and <em>D. protaeiformis “claviformis”</em> 14 ± 6%. Mean water temperature is 28.0 ± 0.6 °C and conductivity at 0.56 ± 0.04 mS/cm. This assemblage has low species diversity (SDI=1.9 ± 0.3) which indicates a transitional environment. Biofacies 2 contains samples (n= 24) which are found in shallower areas (0.38 ± 0.15 m) and the assemblage is characterized by <em>C. constricta “aerophila”</em> 25 ± 8%, <em>C. tricuspis</em> 18 ± 5%, <em>Cyclopyxis sp.</em> 9 ± 6 % and <em>L. vas</em> 9 ± 4 %. The SDI for Biofacies 2 is 2.2 ± 0.2 and like Biofacies 1 shows a transitional environment. The average temperature is and 29.0 ± 1.0 °C with mean sp. conductivity also slightly higher than Biofacies 1 at 0.6 ± 0.04 mS/cm.</p> / Master of Science (MSc)
|
14 |
Impact d’un réchauffement climatique sur le fonctionnement de la sphagnosphère : relations polyphenols-communautés microbiennes / Effect of climate warming on the functioning of the sphagnosphere : polyphenols – microbial communities relationshipsJassey, Vincent 25 November 2011 (has links)
Dans un contexte de réchauffement climatique, la fonction puits de carbone des tourbières à sphaignes est susceptible d’être altérée en raison d’une modification des interactions sphaignes-microorganismes, responsables de l’accumulation de carbone. L’objectif de cette thèse a été (1) d’identifier les interactions chimiques entre les polyphénols des sphaignes et les communautés microbiennes des sphaignes et (2) d’évaluer l’impact du réchauffement climatique sur ces relations.Un dispositif expérimental (Open Top Chambers) simulant in situ une hausse modérée des températures (+ 1°C) a été installé sur la tourbière de Frasne (25). La hausse des températures a provoqué une modification du réseau alimentaire microbien avec l’augmentation de la biomasse des bactéries et une baisse importante (-70%) de la biomasse des prédateurs (amibes à thèque). Le réchauffement climatique a également induit une baisse de la production de polyphénols, diminuant ainsi leur effet inhibiteur sur les microorganismes. En parallèle à cette baisse, une hausse des activités enzymatiques phénoloxydases a également été enregistrée. Le réchauffement a ainsi modifié les relations polyphénols – phénoloxydases, deux éléments essentiels du cycle du carbone des tourbières.Les différents changements induits par le réchauffement climatique (polyphénols, phénoloxydases, réseau trophique microbien) ont aussi conduit à une modification des relations « sphaignes-microorganismes » via une accélération potentielle du recyclage des nutriments, ce qui pourrait influencer sur le long terme le fonctionnement de l’écosystème tourbière. / Carbon stocks of Sphagnum-peatlands are likely to be altered by climate warming due to important changes in “Sphagnum-microorganisms” relationships which are responsible for carbon sequestration. The objectives of the thesis are (1) to identify the chemical interactions between Sphagnum-polyphenols and Sphagnum associated microbial communities and (2) to understand the impact of warming on these relationships.An experimental design using Open-Top-Chambers (OTC) was used to simulate an increase of air temperatures (+1°C) on a peatland situated in Jura Mountains (Frasne, 25). Temperature increase induced a modification of the microbial food web with an increase of the biomass of bacteria and a strong decrease of the biomass of top-predators (-70%), i.e. testate amoebae. Warming also induced a decrease of Sphagnum-polyphenols, diminishing their inhibitory effect on microbial communities. In parallel, an increase of phenoloxidase enzymatic activities was recorded in OTC. Climate warming thus modified polyphenol-phenoloxidase interplay, two crucial components of carbon cycle in peatlands. Warming effects on the different components – i.e. polyphenols, phenoloxidases, microbial food web – induced a modification of Sphagnum-microbial communities interplay, favoring carbon and nutrient recycling, which could alter peatland functioning in long-term.
|
15 |
Taxonomia dos Arcellinida Kent, 1880 (Protista: Ramicristates) do parque ecológico do rio Tietê / Taxonomy of the Arcellinida Kent, 1880 (Protista: Ramicristates) of the Tiete River Ecological Park.Lahr, Daniel José Galafasse 13 April 2006 (has links)
O presente trabalho explora os aspectos taxonomicos, ecologicos, morfologicos, biometricos e biogeograficos dos Arcellinida Kent, 1880 coletados no Parque Ecologico do Rio Tiete, Sao Paulo Brasil. Foram encontrados organismos pertencentes a cerca de 30 taxons nominais, no entanto, a revisao da literatura, novos dados morfologicos obtidos atraves do Microscopio Eletronico de Varredura e medidas biometricas realizadas com grande numero de individuos permitem afirmar que muitos destes taxons estao se referindo a mesma entidade na natureza. Logo, na presente pesquisa sao descritas, com detalhes de distribuicao geografica, morfologia ultra-estrutural, morfometria e ecologia, especies pertencentes a quatro familias e cinco generos: Difflugia corona Wallich, 1864; Difflugia gramen Penard, 1902; Difflugia lanceolata Penard, 1890; Difflugia claviformis Penard, 1899; Difflugia gigantea Chardez, 1967; Centropyxis aculeata (Ehrenberg, 1838); Netzelia wailesi (Ogden, 1980); Lesquereusia modesta Rhumbler, 1895; Lesquereusia mimetica Penard, 1911; Arcella hemisphaerica Perty, 1852; Arcella gibbosa Penard, 1890; Arcella discoides Ehrenberg, 1871 e Arcella brasiliensis Cunha, 1913. Sao discutidas inovacoes taxonomicas para que a comparacao de dados obtidos usando tecnicas atuais com aqueles reportados na literatura tradicional seja feita da maneira mais explicita possivel, de modo a delimitar melhor o conceito taxonomico de cada especie abordada. / The present survey explores the taxonomic, ecologic, morphologic, biometric and biogeographic aspects of the Arcellinida Kent, 1880 collected at the Ecological Park of the Tiete River, Sao Paolo Brazil. Around 30 nominal taxa were identified, however, a review of the literature and new morphologic data obtained via the Scanning Electron Microscope and biometric measures with a large number of individuals allow the inference that many of these taxa are referring to the same natural entity. Therefore, the present work describes species from four families and five genera, along with details about geographic distribution, ultra-structural morphology, morphometry and ecology: Difflugia corona Wallich, 1864; Difflugia gramen Penard, 1902; Difflugia lanceolata Penard, 1890; Difflugia claviformis Penard, 1899; Difflugia gigantea Chardez, 1967; Centropyxis aculeata (Ehrenberg, 1838); Netzelia wailesi (Ogden, 1980); Lesquereusia modesta Rhumbler, 1895; Lesquereusia mimetica Penard, 1911; Arcella hemisphaerica Perty, 1852; Arcella gibbosa Penard, 1890; Arcella discoides Ehrenberg, 1871 e Arcella brasiliensis Cunha, 1913. Taxonomic innovations are discussed in order to make comparison of recent data with those reported on traditional literature a more explicit practice, allowing a better understanding of each species taxonomic concept.
|
16 |
Taxonomia dos Arcellinida Kent, 1880 (Protista: Ramicristates) do parque ecológico do rio Tietê / Taxonomy of the Arcellinida Kent, 1880 (Protista: Ramicristates) of the Tiete River Ecological Park.Daniel José Galafasse Lahr 13 April 2006 (has links)
O presente trabalho explora os aspectos taxonomicos, ecologicos, morfologicos, biometricos e biogeograficos dos Arcellinida Kent, 1880 coletados no Parque Ecologico do Rio Tiete, Sao Paulo Brasil. Foram encontrados organismos pertencentes a cerca de 30 taxons nominais, no entanto, a revisao da literatura, novos dados morfologicos obtidos atraves do Microscopio Eletronico de Varredura e medidas biometricas realizadas com grande numero de individuos permitem afirmar que muitos destes taxons estao se referindo a mesma entidade na natureza. Logo, na presente pesquisa sao descritas, com detalhes de distribuicao geografica, morfologia ultra-estrutural, morfometria e ecologia, especies pertencentes a quatro familias e cinco generos: Difflugia corona Wallich, 1864; Difflugia gramen Penard, 1902; Difflugia lanceolata Penard, 1890; Difflugia claviformis Penard, 1899; Difflugia gigantea Chardez, 1967; Centropyxis aculeata (Ehrenberg, 1838); Netzelia wailesi (Ogden, 1980); Lesquereusia modesta Rhumbler, 1895; Lesquereusia mimetica Penard, 1911; Arcella hemisphaerica Perty, 1852; Arcella gibbosa Penard, 1890; Arcella discoides Ehrenberg, 1871 e Arcella brasiliensis Cunha, 1913. Sao discutidas inovacoes taxonomicas para que a comparacao de dados obtidos usando tecnicas atuais com aqueles reportados na literatura tradicional seja feita da maneira mais explicita possivel, de modo a delimitar melhor o conceito taxonomico de cada especie abordada. / The present survey explores the taxonomic, ecologic, morphologic, biometric and biogeographic aspects of the Arcellinida Kent, 1880 collected at the Ecological Park of the Tiete River, Sao Paolo Brazil. Around 30 nominal taxa were identified, however, a review of the literature and new morphologic data obtained via the Scanning Electron Microscope and biometric measures with a large number of individuals allow the inference that many of these taxa are referring to the same natural entity. Therefore, the present work describes species from four families and five genera, along with details about geographic distribution, ultra-structural morphology, morphometry and ecology: Difflugia corona Wallich, 1864; Difflugia gramen Penard, 1902; Difflugia lanceolata Penard, 1890; Difflugia claviformis Penard, 1899; Difflugia gigantea Chardez, 1967; Centropyxis aculeata (Ehrenberg, 1838); Netzelia wailesi (Ogden, 1980); Lesquereusia modesta Rhumbler, 1895; Lesquereusia mimetica Penard, 1911; Arcella hemisphaerica Perty, 1852; Arcella gibbosa Penard, 1890; Arcella discoides Ehrenberg, 1871 e Arcella brasiliensis Cunha, 1913. Taxonomic innovations are discussed in order to make comparison of recent data with those reported on traditional literature a more explicit practice, allowing a better understanding of each species taxonomic concept.
|
17 |
La composition des thèques d'amibes xénosomiques : utilisation potentielle comme bio-indicateur des dépôts de particules d’origine atmosphérique / Xenomic testate amoebae shells composition : potential use as bio-indicator of atmospheric particle depositsDelaine, Maxence 19 November 2016 (has links)
Les amibes à thèque, également appelés thécamoebiens, sont des micro-organismes unicellulaires, qui construisent une enveloppe rigide, appelée thèque (Adl et al., 2012). Ces thèques ont des tailles, formes et natures très variées (Ogden & Hedley, 1980). Les récentes études sur la composition des thèques ont conduit à émettre l’hypothèse que les amibes xénosomiques (constituées de particules exogènes), peuvent constituer des bio-indicateurs pertinents de la diversité particulaire de l’environnement minéral, organique et biologique dans lequel elles évoluent.L’objectif principal des recherches menées au cours de cette thèse vise donc à caractériser la composition des thèques d’amibes xénosomiques et à en évaluer leur utilisation potentielle en tant que bio-indicateurs des dépôts de particules d'origine atmosphérique. Pour cela, des thèques d’amibes ont été analysées in situ en conditions naturelles et après dépôts artificiels de particules minérales allochtones.Ces travaux permettent de dégager plusieurs conclusions majeures :(1) La taille des particules minérales intégrées dans la thèque xénosomique de Bullinularia indica est similaire à celle des particules minérales transportées dans l'atmosphère; (2) les particules minérales intégrées dans les thèques sont des silicates stables dans les conditions physico-chimiques régnant dans les tourbières, les bryophytes et les sols étudiés; (3) certains minéraux comme la phlogopite, même lorsqu’ils sont présents en de fortes concentrations, ne sont jamais intégrés par les amibes; (4) la combinaison des observations portant sur la taille, la forme et la nature des particules utilisées par des amibes xénosomiques permet de poser les bases de l'utilisation des amibes à thèques pour la bio-indication de la diversité particulaire atmosphérique récente ou ancienne. / Theca-like amoebae, also called thecaamoebius, are unicellular microorganisms, which construct a rigid envelope called theca (Adl et al., 2012). These themes have very varied sizes, shapes and natures (Ogden & Hedley, 1980). Recent studies on the composition of the themes have led to the hypothesis that xenosomal amoebae (constituted by exogenous particles) can constitute relevant bio-indicators of the particulate diversity of the mineral, organic and biological environment in which they evolve . The main objective of the research carried out during this thesis is therefore to characterize the composition of the xenosomal amoebae and to evaluate their potential use as bioindicators of deposits of atmospheric particles. For this purpose, amoeba theae were analyzed in situ under natural conditions and after artificial deposits of allochtonous mineral particles. Several major conclusions can be drawn from this work: (1) The size of the mineral particles integrated in the xenosomal theca of Bullinularia indica Is similar to that of mineral particles transported into the atmosphere; (2) the mineral particles integrated into the thecs are stable silicates under the physico-chemical conditions prevailing in the peatlands, bryophytes and soils studied; (3) some minerals such as phlogopite, even when present in high concentrations, are never integrated by amoebae; (4) the combination of observations on the size, shape and nature of the particles used by xenosomic amoebae forms the basis for the use of tea amoeba for bioindication of recent or former atmospheric particulate diversity .
|
18 |
Таксономија тестатних амеба које насељавају маховине на подручју Источне Херцеговине / Taksonomija testatnih ameba koje naseljavaju mahovine na području Istočne Hercegovine / Taxonomy of moss-dwelling testate amoebae from East HerzegovinaLuketa Stefan 08 December 2020 (has links)
<p>Докторска дисертација представља таксономску студију тестатних амеба Источне Херцеговине базирану искључиво на резултатима сопствених истраживања с обзиром да на овом подручју тестатне амебе до сада нису проучаване, те не постоје историјске музејске колекције. На подручју Источне Херцеговине регистровано је 40 врста тестатних амеба које су сврстане у 10 фамилија и један род без јасног места у класификационом систему. Сви регистровани таксони тестатних амеба су нови за фауну Босне и Херцеговине. Укупно је анализирано 24.549 јединки, од чега су 23.242 јединке припадале групи тестатних амеба са лобоподијама (супергрупа Amoebozoa), а 1307 јединки је припадало групи тестатних амеба са филоподијама (супергрупа Cercozoa). Најзначајнији резултат ове дисертације је опис пет нових врста за науку које припадају родовима<br />Centropyxis, Heleopera и Nebela. Морфотип означен као C. cf. aerophila се од врсте C. aerophila разликује по томе што се на крају љуштурице не налази пар крупних честица кварца,а и љуштурица је нешто дужа (46‒81 μm код врсте C. aerophila према 67‒ 88 μm код врсте C. cf. aerophila). Морфотип означен као C. cf. platystoma значајно се пре свега морфолошки разликује од врсте C. platystoma, те је закључено да се ради о неописаној врсти.У оквиру рода Heleopera описан је нови морфотип сличан врсти H. rosea који представља нову врсту за науку. Морфометријске разлике су релативне, тј. нису строго дискриминаторне, те се морају комбиновати са морфолошким разликама које су такође тешко yочљиве. Наиме, поред разлике у боји љуштурице, најбољи дискриминаторни морфолошки карактер је општи облик љуштурице. Љуштурице врсте H. rosea су робусног облика, док су љуштурице врсте Heleopera cf. rosea знатно елегантније ‒ уже су и имају облије ивице. Највеће морфометријске разлике у индексним карактерима су забележене за однос ширине и дужине љуштурице и однос ширине апертуре и ширине љуштурице.Морфотип Nebela cf. collaris се од врсте N. collaris јасно разликује пре свега морфолошки и еколошки, а морфометријски веома мало. Наиме, најважнија морфолошка одлика која морфотип N. cf. collaris раздваја од врсте N. collaris су таласасте ивице љуштурице, а еколошка разлика се јавља у смислу да врста N. collaris насељава зелене маховине док морфотип N. cf. collaris насељава сфагнумске маховине. Морфотип N. cf. tincta var. major се од морфотипа N. cf. collaris разликује пре свега по јасно израженом сужењу у делу близу апертуре, тј. израженом врату. Такође, морфотип N. cf. tincta var. major никада нема таласасте ивице љуштурице,док се код јединки морфотипа N. cf. collaris ова карактеристика често јасно уочава.</p> / <p>Doktorska disertacija predstavlja taksonomsku studiju testatnih ameba Istočne Hercegovine baziranu isključivo na rezultatima sopstvenih istraživanja s obzirom da na ovom području testatne amebe do sada nisu proučavane, te ne postoje istorijske muzejske kolekcije. Na području Istočne Hercegovine registrovano je 40 vrsta testatnih ameba koje su svrstane u 10 familija i jedan rod bez jasnog mesta u klasifikacionom sistemu. Svi registrovani taksoni testatnih ameba su novi za faunu Bosne i Hercegovine. Ukupno je analizirano 24.549 jedinki, od čega su 23.242 jedinke pripadale grupi testatnih ameba sa lobopodijama (supergrupa Amoebozoa), a 1307 jedinki je pripadalo grupi testatnih ameba sa filopodijama (supergrupa Cercozoa). Najznačajniji rezultat ove disertacije je opis pet novih vrsta za nauku koje pripadaju rodovima<br />Centropyxis, Heleopera i Nebela. Morfotip označen kao C. cf. aerophila se od vrste C. aerophila razlikuje po tome što se na kraju ljušturice ne nalazi par krupnih čestica kvarca,a i ljušturica je nešto duža (46‒81 μm kod vrste C. aerophila prema 67‒ 88 μm kod vrste C. cf. aerophila). Morfotip označen kao C. cf. platystoma značajno se pre svega morfološki razlikuje od vrste C. platystoma, te je zaključeno da se radi o neopisanoj vrsti.U okviru roda Heleopera opisan je novi morfotip sličan vrsti H. rosea koji predstavlja novu vrstu za nauku. Morfometrijske razlike su relativne, tj. nisu strogo diskriminatorne, te se moraju kombinovati sa morfološkim razlikama koje su takođe teško yočljive. Naime, pored razlike u boji ljušturice, najbolji diskriminatorni morfološki karakter je opšti oblik ljušturice. LJušturice vrste H. rosea su robusnog oblika, dok su ljušturice vrste Heleopera cf. rosea znatno elegantnije ‒ uže su i imaju oblije ivice. Najveće morfometrijske razlike u indeksnim karakterima su zabeležene za odnos širine i dužine ljušturice i odnos širine aperture i širine ljušturice.Morfotip Nebela cf. collaris se od vrste N. collaris jasno razlikuje pre svega morfološki i ekološki, a morfometrijski veoma malo. Naime, najvažnija morfološka odlika koja morfotip N. cf. collaris razdvaja od vrste N. collaris su talasaste ivice ljušturice, a ekološka razlika se javlja u smislu da vrsta N. collaris naseljava zelene mahovine dok morfotip N. cf. collaris naseljava sfagnumske mahovine. Morfotip N. cf. tincta var. major se od morfotipa N. cf. collaris razlikuje pre svega po jasno izraženom suženju u delu blizu aperture, tj. izraženom vratu. Takođe, morfotip N. cf. tincta var. major nikada nema talasaste ivice ljušturice,dok se kod jedinki morfotipa N. cf. collaris ova karakteristika često jasno uočava.</p> / <p>The PhD thesis is a taxonomic study of testate amoebae from East Herzegovina based exclusively on the results of our own research, given that testate amoebae have not been studied in this region so far, and there are no historical museum collections. In the region of East Herzegovina,40 testate amoeba species have been registered, which are classified into 10 families and one genus without a clear place in the classification system. All registered testate amoeba taxa are new to the fauna of Bosnia and Herzegovina. A total of 24,549 individuals belonged to the group of testate amoebae with lobopodia (supergroup Amoebozoa), and 1307 individuals belonged to the group of testate amoebae with filopodia (supergroup Cercozoa). The most significant results of this PhD thesis are the descriptions of five new species for science belonging to the genera Centropyxis, Heleopera, and Nebela. The morphotype Centropyxis cf. aerophila differs from C. aerophila in that there is no large quartz particles at the shell end, and the shell is slightly longer (46‒81 μm in C. aerophila versus 67‒88 μm in C. cf. aerophila). The morphotype C. cf. platystoma differs significantly morphologically from C. platystoma, so it was concluded that it is an undescribed species. Within the genus Heleopera a new morphotype similar to H. rosea has been described, representing a new species for science. Morphometric differences are relative, i.e. they are not strictly discriminatory, and must be combined with morphological differences that are difficult to detect. Namely, in addition to the difference in the color of the shell, the best discriminatory morphological character is the general shell shape. Shells of H. rosea are red and robust in shape, while shells of H. cf. rosea are volet and much more elegant ‒ they are narrower and have rounded edges. The largest morphometric differences in the index characters were observed for shell width/shell length ratio and aperture width/shell width ratio. The morphotype Nebela cf. collaris clearly differs from N. collaris primarily morphologically and ecologically, but morphometrically very little. Namely, the most important morphological character that N. cf. collaris separates from N. collaris are the wavy edges of the shell, and the ecological difference occurs in the sense that N. collaris inhabits green mosses while N. cf. collaris inhabits Sphagnum mosses. The morphotype N. cf. tincta var. major from the morphotype N. cf. collaris differs primarily by a clearly pronounced narrowing in the part near the aperture, i.e. pronounced neck. Also, the morphotype N. cf. tincta var. major never has a wavy edge of the shell, while in N. cf. collaris this feature is often clearly observed.</p>
|
19 |
Interakce mikroskopických hub a krytenek v opadu smrku ztepilého / Interactions of microscopic fungi and testate amoebae in Norway spruce litterKonvalinková, Tereza January 2011 (has links)
Both testate amoebae and fungi are common inhabitants of coniferous litter. Their interactions in this environment were rarely studied, although they reach high biodiversity and can play a significant role in nutrient cycling in this environment. In this study, a cultivation of litter needles in the damp chambers was used to investigate interactions between fungi and testate amoebae. Observation of spruce litter needles in environmental scanning electron microscope was used to better characterize testate amoebae communities directly on the needles. Additionally, two experiments changing the biotic conditions in the microcosm were used to follow a principle of the interactions. Three species of testate amoebae from litter needles were able to colonize the filter paper on the bottom of the damp chambers. Occurrence of Phryganella acropodia and Assulina muscorum on the filter paper was significantly fuelled by the presence of mycelium. Assulina muscorum was associated with the fungal spores and Arcella discoides was attracted by sporulating colonies of Cladosporium spp. in the damp chambers. By contrast, no association of putatively mycophagous Phryganella acropodia with fungal spores was observed. Arcella discoides was attracted both by live and death mycelium in additional experiment. Interestingly, the...
|
20 |
Aspects of succession law in ancient Egypt with specific reference to testamentary dispositionsVan Blerk, Nicolaas Johannes 11 1900 (has links)
Text in English / This study indicates the strong link between the belief in the afterlife and the inception of testamentary dispositions in ancient Egypt. To understand law, and specifically succession law, the importance of religion must be understood. Religion was embedded in society. One of the most important principles of religion was maat, which formed the basis for law. The living and dead formed part of the same community. The belief in the afterlife implied an immortality, an eternal continuation of life. There was a moral relationship between the dead and living and the deceased was dependent on sustenance after death. There was an obligation for the family to sustain the deceased, but this piety diminished and a need arose to make arrangements for sustenance prior to death. This led to the inception of the testamentary disposition document.
The purpose of succession law is to maintain and strengthen the socio-economic structure in society and it therefore fulfils a social function. At the heart is the nuclear family. In ancient Egypt two systems of succession law developed: customary intestate succession and testate succession (by way of testamentary disposition). Different types of documents were used in ancient Egypt to serve the purpose of a testamentary disposition, such as the pious foundation and the imyt-pr. Important concepts and elements of succession law from the Old, Middle and New Kingdoms are identified and discussed. These include fideicommissum, trusts, usufruct, habitatio, legacies, the importance to indicate ownership of property, etc.
The testamentary disposition documents of ancient Egypt must be one of the earliest examples of testate succession law. The Egyptian testamentary disposition, with its concepts and elements of succession law, was established centuries before Rome and Roman law were established. The resemblance to our modern-day wills and testaments through our Roman testate succession law heritage is remarkable. / Classics and World Languages / D. Litt. et Phil. (Ancient Near Eastern Studies)
|
Page generated in 0.0501 seconds