324 research outputs found
A Comparison of Gill Net Labeling Methods for Fisher Identification
Six methods of fisher identification were applied to gill net float lines for 230 trials. Three methods marked floats and three methods were attached to the line between floats. Nets were set and retrieved using a hydraulic net reel in order to test failure rate and remarking ease under typical field conditions. Cost and application time of each marking methods was also quantified. Two of the three float marking methods (hot brand, Sharpie® marker) experienced a 0% failure rate. The third method, however, (paint) had the highest failure rate of the study ( 10% ). Self applied float marking methods required more time to apply but were less expensive than line marking methods. All line marking methods experienced a failure rate of 2% or less. Line marking tag cost were higher due to their production by various professional tag manufacturing companies. Good retention of one of the line markers ( crab pot tag) on vertical buoy lines suggests that these types of markers may offer a reasonable method of labeling such lines below buoy breakaways in pot fisheries. Neither float nor line marking methods differed significantly in number of characters which could be presented, however, imprinting restrictions (set up) would significantly increase cost if line tags had to contain specific information (mesh sizes) where as addition of such information on floats would only require additional time
Bycatch Reduction Panels Improve Catch Composition and Size Distribution of Fishes Retained in Pound Nets
Integrated tectonic and quantitative thermochronometric investigation of the Xainza rift, Tibet
The Himalayan Tibetan orogeny is a superlative in many respects and has drawn a lot of attention because of its unrivaled landscape and geologic attractiveness. Many processes including ocean-continent and continent-continent collision, mountain building, plateau uplift, and E-W extension can be studied. This study utilizes a variety of different techniques to improve understanding of the history of the Lhasa terrane from its collision with the Qiangtang terrane to the north, subsequent amalgamation of the Indian subcontinent to the south, and late-stage extensional tectonics. The Xainza rift in the central Lhasa terrane, an about 200 km long N-S trending structure, provides access to deeper crustal rocks enabling the study of magmatic evolution as well as timing and magnitude of footwall uplift during E-W extension. Zircon U/Pb dating reveals three distinct stages of magmatism at ~140-110 Ma, ~65-50 Ma, and ~15 Ma. The Cretaceous magmatism is triggered by southward subduction of the Bangong ocean slab whereas early Tertiary rocks are emplaced as a result of northward subduction of the Neo-Tethyan slab. The Miocene magmatic rocks result from additional heat influx following delamination of an over-thickened Lhasa lithosphere and show signs of significant assimilation of surrounding early Tertiary plutons. Whole rock geochemistry reveals that the Lhasa terrane has ancient and thicker crust in its interior and more juvenile crust going outward, which has a first order effect on the observed isotopic ratios. Metamorphosed basaltic melts, under-plated during the early Tertiary, play a major role in the observed elemental patterns (high La/Yb and Sr/Y ratios) in post-collisional rocks. Low-temperature thermochronology results from vertical transects as well as single samples, reveal that E-W extension initiated in the middle Miocene. Rift morphology combined with decreasing apatite (U-Th)/He ages from north to south support the proposed model of zipper-like opening of the rift triggered by right-lateral slip on the Gyaring Co fault. Major phase of rift shoulder uplift is constrained at ~12-10 Ma in the north and ~8 Ma in the southernmost segment. These dates coincide with the waning stages of south-directed thrusting along major faults in the Himalayas, suggesting a causal relationship between N-S shortening and E-W extension. Thermal history modeling of (U-Th)/He data is a critical component of this study and the results are based on improved analysis of these data utilizing a newly developed software package. Modeling samples from vertical transects together provides superior control over the time-temperature evolution of the sampled crustal sections allowing for better constraint estimates of initiation and magnitude of rifting
Mesh-Specific Catch Compositions and Size Distributions Occuring in Virginia\u27s 2005 Winter-Spring Striped Bass Gill Net Fishery
Ichthyofaunal and dietary analysis of sympatric piscivores in a Chesapeake Bay littoral zone: Including bioenergetic models of growth and diel temperature sanctuary use
The first section of this dissertation describes the ichthyofaunal community of a mesohaline Chesapeake Bay April--November. Fish assemblages were sampled using two seine gears, a small seine that sampled 352 m 2 and a 914m haul-seine that sampled 144,473 m2. The small seine collected 32 finfish species. The larger gear captured 31 finfish species, including 17 that were not sampled by small gear. Sampled diversity was greater but density estimates were similar to those determined previously by other investigators using flume-net, drop-ring, and otter trawl techniques. Nocturnal abundance of larger fishes far exceeded daylight. Fish abundance and size distribution varied seasonally in both gears. The second section describes the littoral diet composition of striped bass (Morone saxatilis ), bluefish (Pomatomus saltatrix), and weakfish (Cynoscion regalis). These species were the most abundant piscivores sampled in the littoral zone. as in previous Chesapeake Bay diet studies the importance of pelagic prey increased with predator size, however, littoral diets evidenced greater dietary diversity and dependence on crustacean prey items. The third section consists of bioenergetic models that predict piscivore growth based on estimated nocturnal consumption and test energetic consequences of diel thermal refugia. Bluefish and weakfish were predicted to achieve better growth rates than those evidenced by field samples of aged fishes collected from across random Chesapeake habitats. Models predict that striped bass experience declining condition during warm water periods due to physiological stresses and poor prey acquisition. Theoretical diel relocation models illustrated how important species and age specific metabolic restrictions due to physical parameters are to fish health. Findings suggest that habitat specific physical dynamics may be as important as prey provision in determination of and spatial assessments of essential fish habitats
Efficiency of Pound-Net Cull Panels: A Comparison of Size Selectivity and Relative Release for Weakfish (Cynoscion regalis) and Summer Flounder (Paralichthys dentatus)
Mitose assoziierter Zelltod nach Chemotherapie vermittelter Durchbrechung des G2-Zellzyklus-Kontrollpunktes
Eine häufige Eigenschaft von Tumorzellen ist die Fehlfunktion von Signalwegen, die den Zellzyklus regulieren, wodurch eine erhöhte Proliferations- und Mutationsrate ermöglicht wird. Zellen mit einer gestörten Funktion des p53-abhängigen DNA-Schaden-Signalwegs in der G1-Phase besitzen einerseits diese Tumor-fördernden Eigenschaften und sind andererseits vollständig auf den DNA-Schaden-Signalweg der G2-Phase angewiesen, um schädlichen DNA-Schaden reparieren zu können. Ein neues Konzept einer kombinierten Chemotherapie besteht in der sequentiellen Gabe einer DNA-schädigenden Substanz und eines CHK1-Inhibitors, welcher den DNA-Schaden-Signalweg der G2-Phase hemmt. Zellen mit gestörter p53-Funktion können so weder in der G1- noch in der G2-Phase arretieren, um eine DNA-Reparatur zu ermöglichen, und versterben in großer Zahl nach Eintritt in die Mitose. Die hierbei eingeleiteten mitotischen und apoptotischen Signalwege sind bisher nicht im Detail bekannt und sollten in dieser Arbeit weiter untersucht werden.
Ich konnte zeigen, dass in Zellen, die nach Behandlung mit Adriamycin (Topoisomerase-II-Hemmstoff) und UCN-01 (CHK1-Hemmstoff) mitotisch arretieren, neben der Einleitung einer mitochondrialen Apoptose auch antiapoptotische Signalwege aktiviert werden. So kommt es zu einer Abnahme der aktiven Form des proapoptotischen Proteins Bax und einer Hyperphosphorylierung des antiapoptotischen Proteins Bcl-2. Durch zusätzliche Gabe von Roscovitine (CDK1-Hemmstoff) kann der Zelltod deutlich verstärkt werden, was möglicherweise in einer direkten antiapoptotischen Funktion von CDK1 in der Mitose oder einer Entblockung apoptotischer Signale durch den mitotischen Austritt begründet ist. Eine ähnliche Therapieverstärkung zeigte sich nach einer Kombination mit dem Aurora-B-Inhibitor ZM447439. Diese Ergebnisse stützen den allgemeinen Ansatz, Tumorzellen mit DNA-Schaden in die Mitose zu treiben und einen hierdurch eingeleiteten Zelltod durch Interaktion mit mitotischen oder apoptotischen Proteinen zu verstärken.
Ob eine kombinierte sequentielle Chemotherapie aus DNA-Schädigung, CHK1-Inhibierung und CDK1-Inhibierung eine Option zur Effizienzsteigerung und Resistenzumgehung einer antiproliferativen Therapie darstellen könnte, müssen weitere Untersuchungen zeigen. Niedermolekulare CHK1- und CDK1-Inhibitoren befinden sich als Einzelsubstanzen oder Kombinationstherapien in der klinischen Erprobung
Darstellung und Bedeutung von Politischem Opportunismus im Film "Der Fall Jägerstätter" von Axel Corti
Die vorliegende Diplomarbeit mit dem Titel „Darstellung und Bedeutung von Politischem Opportunismus im Film `Der Fall Jägerstätter` von Axel Corti“ ist als Beitrag zur politikwissenschaftlichen Kulturforschung zu verstehen. Im Rahmen eines Methoden-Mix bestehend aus historiographischer Begriffsgeschichte nach Reinhart Koselleck, systematischer Filmanalyse nach Helmut Korte und qualitativer Inhaltsanalyse nach Philipp Mayring wird versucht, das Phänomen des Politischen Opportunismus anhand des Filmdokuments „Der Fall Jägerstätter“ des Regisseurs Corti wissenschaftlich zu untersuchen. Demnach wird die filmische Darstellung von Politischem Opportunismus durch Corti mit einer auf Basis der historiographischen Begriffsgeschichte formulierten Definition dieses Phänomens verglichen. Im Zuge dessen zeigt sich, dass sich der künstlerische Zugang Cortis über weite Strecken mit dem wissenschaftlich erarbeiteten Ergebnis deckt, wonach Politischer Opportunismus als eine spezifische Form von ethischem Egoismus zu betrachten ist. Weiters wird die beeindruckende Wirkung von Cortis Filmarbeit auf die Erinnerungskultur in Österreich erörtert. Zuletzt wird im Rahmen der Filmanalyse auch sehr deutlich der negative Effekt politisch opportunistischen Handelns aufgezeigt. Abgerundet und untermauert werden die wissenschaftlichen Schlussfolgerungen durch Auszüge aus einem Experten-Interview mit dem ehemaligen ORF-Generalintendanten und Corti-Vertrauten Gerd Bacher.The diploma thesis entitled “Darstellung und Bedeutung von Politischem Opportunismus im Film `Der Fall Jägerstätter` von Axel Corti“ makes a contribution to cultural studies in the framework of political science. It was done using a combination of three certain methods: conceptual history according to Reinhart Koselleck, systematic film analysis according to Helmut Korte and qualitative content analysis according to Philipp Mayring. My personal intention was to investigate the phenomenon of political opportunism with respect to the film “Der Fall Jägerstätter” by the famous Austrian film director Axel Corti. Therefore, the cinematic representation of political opportunism is compared with a definition formulated on the basis of the conceptual history. It appears that the artistic access coincides about wide distances with the academically compiled result after which political opportunism is to be looked as a specific form of ethical egoism. Furthermore the impressive effect from Cortis film work on the reminiscent culture is discussed. Last the negative effect of politically opportunistic action is indicated within the scope of the film analysis also very clearly. The scientific conclusions are underpinned by extracts from an expert's interview with the former ORF director Gerd Bacher
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