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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The locomotory mechanisms of lower tetrapods

Barclay, Oliver R. January 1944 (has links)
No description available.
12

Feuersalamander - Salamandra salamandra

Siegel, Stefan 31 August 2021 (has links)
Der Feuersalamander (Salamandra salamandra) ist eine von 18 in Sachsen vorkommenden Amphibienarten. Dieser Schwanzlurch kann etwa 20 cm lang werden und ist mit seiner gelben Flecken- oder Streifenzeichnung auf schwarzem Grund unverwechselbar. Diese signalisiert seinen Feinden, dass er nicht genießbar ist, denn auf seiner Haut befinden sich Drüsen, aus denen er das Gift Samandarin absondert. Deshalb haben erwachsene Feuersalamander auch kaum Feinde. In Gefangenschaft können die Tiere über 50 Jahre alt werden. Jeder Salamander besitzt ein individuelles Fleckenmuster und so kann man die Lurche in freier Wildbahn über lange Zeit beobachten. Bereits bei den mit Büschelkiemen ausgestatteten Larven kann man an jedem Beinansatz einen gelben Fleck erkennen, was sie von den sehr ähnlichen Molchlarven unterscheidet. Zur besseren Abschätzung des Gesamtvorkommens sowie von Rückgangs- bzw. Verlustursachen werden zurzeit alle potenziellen Lebensräume sowie frühere Fundorte auf das aktuelle Vorkommen der Art überprüft. Hierfür brauchen wir Ihre Mithilfe. Wenn Sie Feuersalamander oder deren Larven entdeckt haben, dann schreiben Sie uns Ihre Beobachtung mit Anzahl, Ort, Datum sowie Fundumstände bzw. Verhalten, wenn möglich mit Foto, per Post oder E-Mail an: Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Ref. 62 Artenschutz, Stichwort „Feuersalamander“, Pillnitzer Platz 3, 01326 Dresden oder per E-Mail an: artenerfassung.lfulg@smul.sachsen.de Redaktionsschluss: 29.08.2014
13

The biomechanics of vertebrae over evolutionary transitions between water and land: examples from early Tetrapoda and Crocodylomorpha

Molnar, Julia Louise January 2014 (has links)
With the transition from water to land in early tetrapods, and with transitions to secondarily aquatic habits in numerous tetrapod lineages, the functions of the vertebral column were transformed. Morphological changes in the vertebral column are a major mechanism by which vertebrates accommodate changes in locomotor forces. Although morphometric measurements from vertebrae have been correlated with axial mechanics and locomotor behaviour in numerous extant taxa, few studies have sought to test or apply these principles in non-mammalian tetrapods. In my thesis, I reconstructed the vertebral mechanics of fossil taxa that represent intermediate stages in water/land transitions of their lineages. Study taxa were the basal tetrapod Pederpes finneyae, which is one of the earliest known tetrapods to show indications of terrestrial adaptation, and three extinct crocodylomorphs, Terrestrisuchus, Protosuchus, and Pelagosaurus, which span the spectrum from fully terrestrial to primarily aquatic. I used a combination of morphometric measurements and 3D virtual models of bone morphology to estimate intervertebral joint stiffness and range of motion. For comparison, I also reconstructed the vertebral mechanics of four related extant taxa. Correlations between vertebral morphometrics and axial stiffness were statistically tested in (cadaveric) modem crocodylians, and I validated my methodology by comparing my results with data from extant taxa. My results reveal similarities and differences between the two lineages. Intervertebral joint compliance and range of motion tended to decrease with adaptation for terrestrial locomotion, as expected, but this trend seems to have reversed in later forms. Additionally, vertebral mechanics may have been largely controlled by different structural mechanisms in different lineages. The relationship between biomechanics of vertebrae and environment appears to be more complex than previously supposed. However, approaches that combine experimental measurements from extant animals, thorough analysis of fossil morphology, and explicit phylogenetic considerations have the potential to greatly improve locomotor reconstructions of extinct taxa.
14

Selection of modelling level of detail for incorporating stress analysis into evolutionary robotics simulations of extinct and extant vertebrates

Mustansar, Zartasha January 2015 (has links)
This thesis concerns the simulation of locomotion in vertebrates. The state-of-the-art uses genetic algorithms together with solid body kinematics to generate possible solutions for stable gaits. In recent work, this methodology led to a hopping gait in a dinosaur and the researchers wondered if this was realistic. The purpose of the research carried out in this thesis was to examine whether quick and simple finite-element analyses could be added to the simulator, to evaluate a simple ―break or―not break failure criterion. A break would rule out gaits that might damage theowner‘s skeleton. Linear elastic analysis was considered as a possible approach as it would add little overhead to the simulations. The author used X-ray computed tomography and the finite element method to examine the axial loading of a barnacle goose femur. The study considered four levels of detail for a linear elastic simulation, finding that all the analyses carried out overestimated the strength of the bone, when considering safety factors. The conclusion is that to incorporate stress-strain analysis into the gait simulation requires more realistic models of bone behaviour that incorporate the nonlinear response of bone to applied loading. A new study focusing on the use of novel techniques such as model order reduction is recommended for future work. The outputs of this research include chapters written up as journal papers covering a 4D tomography experiment; a level of detail study; an analysis of a purported tendon avulsion injury in Tyrannosaurus rex and a review of the elastic properties of bone.
15

Aplicação de fungos filamentosos para S-oxidação do ácido 2-[4-(1,4-tiazinan-4-ilsulfonil) fenilcarbamoil] benzóico (LASSBio-596) / Application of filamentous fungi for S-oxidation of 2-[4-(1,4-tiazinan-4-ylsulfonyl)phenylcarbamoyl]benzoic acid (LASSBio-596)

Cavaion, Juliana Camila Lopes 04 June 2012 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-12-18T10:55:48Z No. of bitstreams: 1 Dissertação - Juliana Camila Lopes Cavaion - 2012.pdf: 2928983 bytes, checksum: 908363ad8b87e3a821dd54fe80dcb4ce (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-12-18T14:24:31Z (GMT) No. of bitstreams: 1 Dissertação - Juliana Camila Lopes Cavaion - 2012.pdf: 2928983 bytes, checksum: 908363ad8b87e3a821dd54fe80dcb4ce (MD5) / Made available in DSpace on 2014-12-18T14:24:32Z (GMT). No. of bitstreams: 1 Dissertação - Juliana Camila Lopes Cavaion - 2012.pdf: 2928983 bytes, checksum: 908363ad8b87e3a821dd54fe80dcb4ce (MD5) Previous issue date: 2012-06-04 / Filamentous fungi have cytochrome P450 enzyme system similar to mammals whose application allows catalyze phase I oxidative reactions of metabolism. Obtaining functionalized derivatives by these microorganisms was the main purpose of this dissertation. Studies in silico to predict metabolism in the programs MetaPrint2D and SMARTCyp indicated S-oxidation, aromatic hydroxylation and dealkylation reactions, as the most likely S-oxidation in thiomorpholine ring of 2-[4-(1,4-thiazinan-4-ylsulfonyl)phenylcarbamoyl]benzoic acid (LASSBio-596). The filamentous fungi Absidia blakesleana ATCC 26617, Aspergillus candidus ATCC 1009, Beauveria bassiana ATCC 7159, Cunninghamella echinulata ATCC 9244, Cunninghamella echinulata ATCC 9245, Cunninghamella elegans ATCC 36112, Fusarium roseum ATCC 14717 and Streptomyces vendulae ATCC 8664 were used for biotransformation of LASSBio-596. In the reaction conditions applied, substrate dissolved in methanol with concentration of 0.25 mg/mL added to liquid culture medium PDSM and incubated at 27 °C with 200 rpm for 96 hours, the fungus Beauveria bassiana ATCC 7159 performed S-oxidation in the thiomorpholine ring resulting in sulfone derivative of LASSBio-596, called LaBioCon 214, yield of 5.84 %, and it was found the hydrolysis of amide reaction obtaining the compound 4-(thiomorpholinosulfonyl)aniline, LaBioCon 202, yield of 13.8 %. It was noted the solvent used affects the biotransformation process. The monitoring of the reactions and purification of the derivatives obtained were performed by high performance liquid chromatography with ultraviolet detector at 267 nm and preparative chromatography with column Microsorb 100-5 C18 (250 x 10 mm, 5 μm). Subsequently, sulfone derivative was obtained, called LaBioCon 223, by synthesis. Structural characterization was made by classical methods such as 1H NMR and mass spectrometry. / Os fungos filamentosos possuem o sistema enzimático citocromo P450 semelhante ao de mamíferos, cuja aplicação permite catalisar reações oxidativas de fase I do metabolismo. A obtenção de derivados funcionalizados por estes microrganismos foi o objetivo principal deste trabalho. Estudos in silico de previsão do metabolismo nos programas MetaPrint2D e SMARTCyp indicaram reações de S-oxidação, hidroxilação aromática e desalquilação, sendo mais provável a S-oxidação no anel tiomorfolina do ácido 2-[4-(1,4-tiazinan-4-ilsulfonil)fenilcarbamoil]benzóico (LASSBio-596). Os fungos filamentosos Absidia blakesleana ATCC 26617, Aspergillus candidus ATCC 1009, Beauveria bassiana ATCC 7159, Cunninghamella echinulata ATCC 9244, Cunninghamella echinulata ATCC 9245, Cunninghamella elegans ATCC 36112, Fusarium roseum ATCC 14717 e Streptomyces vendulae ATCC 8664 foram empregados para biotransformação do LASSBio-596. Nas condições reacionais aplicadas, substrato solubilizado em metanol com concentração de 0,25 mg/mL adicionado ao meio de cultura líquido PDSM e incubado a 27 °C com 200 rpm por 96 horas, a Beauveria bassiana ATCC 7159 promoveu a S-oxidação no anel tiomorfolina resultando no derivado sulfona do LASSBio-596, denominado LaBioCon 214, com rendimento de 5,84 %, e constatou-se a reação de hidrólise da amida obtendo o composto 4-(tiomorfolina-sulfonil)anilina, LaBioCon 202, com rendimento de 13,8 %. Verificou-se que o solvente utilizado interfere no processo de biotransformação. O monitoramento das reações e a purificação dos derivados obtidos foram realizados por cromatografia líquida de alta eficiência com detector ultravioleta em 267 nm e cromatografia preparativa com coluna Microsorb 100-5 C18 (250 x 10 mm, 5 μm). Posteriormente, foi obtido o derivado sulfona, LaBioCon 223, por via sintética. A caracterização estrutural foi realizada por métodos clássicos como a espectroscopia de ressonância magnética nuclear de hidrogênio e espectrometria de massas.
16

Comparative study on the nervous system of Tunicata to elucidate tunicate phylogeny and character transformations

Braun, Katrin 04 June 2019 (has links)
Tunicata umfasst 3000 marine Arten, mit sehr unterschiedlichen Lebensstrategien. Als eines der drei großen Taxa innerhalb der Chordata, stellt die Evolution der Tunikaten eine Schlüsselkomponente bei der Aufklärung der Evolution der Chordaten und Cranioten dar. Dafür ist ein Verständnis der Merkmalstransformationen innerhalb der Tunikaten notwendig. Leider sind die internen Verwandtschaftsverhältnisse der fünf großen Tunikatentaxa in verschiedenen molekularphylogenetischen Studien widersprüchlich. Bisher gibt es nur wenige morphologische phylogenetische Analysen. Ein Schwerpunkt dieser Arbeit liegt auf der Untersuchung neuroanatomischer Merkmale, da das Nervensystem wahrscheinlich phylogenetische Informationen enthält. Durch das Anwenden moderner morphologischer Methoden, wie hochauflösende konfokale Laserscan- und Elektronenmikroskopie (REM und TEM), und 3d Rekonstruktionen basierend auf lichtmikroskopischen Schnitten, wurde die Verfügbarkeit neuroanatomischer Daten wesentlich verbessert. Die Ergebnisse zeigen, dass die Variation neuroanatomischer Merkmale größer ist als bisher angenommen und dass sich die Gehirnanatomie und die Verteilung von Neurotransmittern in den zwei Stadien der Thaliaceen unterscheidet. Neue unabhängige Merkmale des Nervensystems wurden in einer Matrix kodiert. Ergänzt mit traditionellen in der Tunikatentaxonomie verwendeten Merkmalen, entstand die bisher umfangreichste morphologische Datenmatrix, die 116 Merkmale für insgesamt 54 Arten umfasst. Die kladistische Analyse ergab monophyletische Tunicata, in denen die Appendicularia die Schwestergruppe der übrigen Tunikaten bildet. Ascidiacea ist monophyletisch, während „Thaliacea“ paraphyletisch ist. Zusätzlich wurde eine kombinierte phylogenetische Analyse basierend auf den morphologischen Daten und 18S rDNA-Sequenzen durchgeführt. Eine stufenweise stärkere Gewichtung phänotypischer Merkmale zeigt, dass die morphologischen Daten das Ergebnis der kladistischen Analyse stark beeinflussen. / Tunicata comprises 3000 marine species with diverse life-history strategies. As one of the three major chordate taxa, the evolution of tunicates plays a key role to elucidate chordate and craniate evolution. Therefore, a broader understanding of character transformations within tunicates is essential, but the interrelationships of the five main tunicate subtaxa in previous molecular phylogenetic analyses were contradictory. Morphological phylogenetic analyses are rare. In this comparative study emphasis was given to neuroanatomical characters, as the nervous system probably contains phylogenetic information. Applying modern morphological techniques like high-resolution confocal laser scanning microscopy and electron microscopy (SEM and TEM), serial sectioning for light microscopy, and digital 3d reconstruction, the number of available tunicate neuroanatomical data was considerably increased. It was revealed that the variation of neuroanatomical characters is higher than previously assumed, a specific pattern of serotonin-like immunoreactive cells in ascidians is present, and that brain anatomy and distribution of neurotransmitters in the two thaliacean life-cycle stages differs. Novel independent characters of the central nervous system were coded in a matrix for a cladistic analysis. Including traditional morphological from tunicate literature this effort resulted in the largest morphological data matrix to date, containing 116 phenotypic characters and 54 species. The cladistic analysis resulted in monophyletic Tunicata, with Appendicularia the sister taxon to the remaining tunicates. Furthermore, the monophyly of Ascidiacea is supported, whereas “Thaliacea” are paraphyletic. An additional phylogenetic analysis combining morphological and 18S rDNA-sequence data was performed. A reevaluation of this dataset with a successively increased weighting of the phenotypic data showed that morphological data strongly influence the outcome of the cladistic analysis.
17

Betriebliches Eingliederungsmanagement in KMU

Herold, Stefan 21 January 2014 (has links)
Die Forschungsarbeit hat das Betriebliche Eingliederungsmanagement (im Folgenden BEM) in kleinen und mittleren Unternehmen (im Folgenden KMU) zum Gegenstand. Einerseits wird die Rechtsnorm gem. § 84 Abs. 2 SGB IX aus arbeits- und sozialpolitischer Sicht in Form und Funktion aufgearbeitet. Andererseits wird eine manuale Strategie zur Umsetzung des BEM entwickelt, mittels derer 42 BEM-Fälle in 10 KMU begleitet werden. Nach Diskussion der theoriegeleiteten Erkenntnisse und empirischen Ergebnisse folgt ein Ausblick. Es werden Anregungen zur weiterführenden Forschung gegeben, aber auch Forderungen an die Politik formuliert, die im Handlungsfeld der Präventionsnorm bestehenden und durch die Forschungsarbeit aufgedeckten Problempunkte aufzulösen und somit einen wirksamen Praxistransfer des BEM zu ermöglichen. / The research paper concentrates on Corporate Integration Management (CIM) in small and medium companies (SME). On the one hand the task consists in reviewing the form and function of the legal norm under Section 84 Subsection 2 of Book IX of the German Social Code (SGB) in terms of labour and social policies. On the other hand a manual-based strategy for implementing CIM shall be developed. Following the integration of the legally valid CIM concept with the appropriately adapted framework the manual is subjected to an empirical review. By accompanying 42 CIM cases in 10 SMEs it has been possible to show on the basis of partly standardized and open guided interviews with company experts that the introduction and implementation of CIM is markedly enhanced by means of this manual. The discussion of the theory-guided findings and the empirical results is followed by an outlook. Suggestions for further research are made while the political establishment is called upon to resolve the challenges existing within the scope of the prevention norm and revealed in the research paper thus facilitating an effective transfer of the CIM theory into the practice field.
18

"Was will man noch mehr machen als Arbeitszeit flexibilisieren, Telearbeitsplätze, Karenzierungen ...?". Eine qualitative Studie über pflegefreundliche Maßnahmen in Wiener Unternehmen.

Dawid, Evelyn, Ludescher, Martin, Trukeschitz, Birgit January 2008 (has links) (PDF)
(kein Abstract vorhanden) / Series: Forschungsberichte des Forschungsinstituts für Altersökonomie

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