The ecology and conservation of green turtles (Chelonia mydas) in New Zealand : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Marine Ecology at Massey University, Albany, New Zealand

Historically, little consideration has been given to the occurrence, ecology or conservation of the green turtle (Chelonia mydas) in temperate New Zealand. Located geographically at the southern boundary of the distributional range of green turtles in the southwestern Pacific, reports of this species in New Zealand are often overlooked as occasional visitors or stragglers incidentally carried by ocean currents. This convention may be reasonable when considering the temperature constrained distribution of this poikilothermic marine reptile. Despite this, green turtles have been reported in New Zealand waters for more than 100 years, yet no study has undertaken any in depth investigation as to their occurrence in this region. Therefore, this thesis investigated the presence of green turtles in New Zealand waters to test the hypothesis that their occurrence is ephemeral and incidental. Opportunistic data and samples collected between 1895 and 2013 was collated, reviewed and analysed to investigate several lines of empirical enquiry, including spatio-temporal distribution, population structure, genetic origin, diet composition and anthropogenic effects. Sighting, stranding, and incidental capture revealed a year round presence of post-pelagic immature juveniles to large sub-adult green turtles across northern New Zealand (ca. 34°-38° S). Such occurrence exists despite sea surface temperatures averaging only 14 C during austral winters. The aggregation exhibited a female:male sex ratio of 1.7:1 which is similar to that reported from proximate warm temperate foraging grounds in eastern Australia. Size frequency data indicated that green turtles recruit to neritic habitats of the North Island at ca. 40.8 cm curved carapace length. This reflects a natural postoceanic settlement pattern rather than oceanic-phase stragglers incidentally blown ashore by storm and other stochastic events. Supporting this rationale for natural recruitment, diet component data demonstrates that once green turtles settle into New Zealand’s nearshore coastal habitats, they transition to a benthic foraging strategy. Notably, green turtles in New Zealand do not ontogenetically transition from omnivory to obligate herbivory with age, but instead consume a variable diet of primarily macroalgae and benthic macro invertebrates. Overall, the confirmation of feeding in New Zealand substantially extends the southern foraging limit for green turtles in the Pacific Ocean. Genetic analyses of ~770 base pair sequences of mitochondrial (mt) DNA was conducted on 42 stranded green turtles to characterize the genetic structure of this aggregation. Results identified 15 haplotypes including one orphan haplotype from widely dispersed green turtle stocks across the western, central, and eastern Pacific Ocean. When compared to other regional nesting rookeries and foraging grounds, the New Zealand aggregation exemplified its unique composition, predominantly due to the large proportion of haplotypes from the endemic eastern Pacific clade. These results provide a genetic link to east Pacific stocks in the southwestern Pacific; identifying previously undefined regional connectivity and trans-oceanic dispersal for eastern Pacific green turtles. In order to assess potential human impacts, gross necropsies were conducted on green turtles found stranded in northern New Zealand between 2007 and 2013. Anthropogenic effects predominantly associated with the ingestion of plastic marine debris were identified as the likely cause for the majority of strandings in the North Island. Propeller strike and incidental capture in recreational fisheries were further shown to impact green turtles, particularly for turtles inhabiting neritic habitats adjacent to densely populated urban centres of northeastern New Zealand. Overall, data presented here supports the hypothesis that New Zealand northern neritic habitats provide a transitional developmental habitat for immature green turtles at the edge of their range in the southwestern Pacific Ocean. Genetic analysis reveals this aggregation is unique when compared to other regional foraging grounds, exhibiting links to discrete genetic stocks from across the Pacific Ocean. In addition, the cause of the exponential increase in records observed over time remains unclear, therefore warrants further research and monitoring of this endangered marine reptile; particularly in light of climate-mediated environmental change presently experienced in the region

Resultados preliminares del proceso de minería de datos aplicado al análisis de la deserción en carreras de Informática utilizando herramientas open source

En el presente trabajo se realizó un proceso de minería de datos para generar conocimiento en base a patrones académicos, factores sociales y demográficos, que caractericen a los estudiantes, con la finalidad de pronosticar alumnos desertores de la Carrera Analista en Sistemas de Computación de la Facultad de Ciencias Exactas, Químicas y Naturales de la Universidad Nacional de Misiones. Como fuente de datos de utilizó el “Cubo 04 Desgranamiento”, exportado del Sistema de Gestión Académica SIU-Guaraní. Los modelos obtenidos se utilizaron para clasificar a los alumnos de otras cohortes. El trabajo se desarrolló bajo la metodología de libre difusión Crisp-DM y con herramientas open source. La calidad de los modelos obtenidos a través de la clasificación con árboles de decisión y redes bayesianas superaron ampliamente las expectativas.Presentado en el VIII Workshop Bases de Datos y Minería de Datos (WBDDM)Red de Universidades con Carreras en Informática (RedUNCI

New biotechnological perspectives of a NADH oxidase variant from Thermus thermophilus HB27 as NAD+-recycling enzyme

<p>Abstract</p> <p>Background</p> <p>The number of biotransformations that use nicotinamide recycling systems is exponentially growing. For this reason one of the current challenges in biocatalysis is to develop and optimize more simple and efficient cofactor recycling systems. One promising approach to regenerate NAD⁺pools is the use of NADH-oxidases that reduce oxygen to hydrogen peroxide while oxidizing NADH to NAD⁺. This class of enzymes may be applied to asymmetric reduction of prochiral substrates in order to obtain enantiopure compounds.</p> <p>Results</p> <p>The NADH-oxidase (NOX) presented here is a flavoenzyme which needs exogenous FAD or FMN to reach its maximum velocity. Interestingly, this enzyme is 6-fold hyperactivated by incubation at high temperatures (80°C) under limiting concentrations of flavin cofactor, a change that remains stable even at low temperatures (37°C). The hyperactivated form presented a high specific activity (37.5 U/mg) at low temperatures despite isolation from a thermophile source. Immobilization of NOX onto agarose activated with glyoxyl groups yielded the most stable enzyme preparation (6-fold more stable than the hyperactivated soluble enzyme). The immobilized derivative was able to be reactivated under physiological conditions after inactivation by high solvent concentrations. The inactivation/reactivation cycle could be repeated at least three times, recovering full NOX activity in all cases after the reactivation step. This immobilized catalyst is presented as a recycling partner for a thermophile alcohol dehydrogenase in order to perform the kinetic resolution secondary alcohols.</p> <p>Conclusion</p> <p>We have designed, developed and characterized a heterogeneous and robust biocatalyst which has been used as recycling partner in the kinetic resolution of <it>rac</it>-1-phenylethanol. The high stability along with its capability to be reactivated makes this biocatalyst highly re-useable for cofactor recycling in redox biotransformations.</p

Effect of cervical collars on intracranial pressure in patients with head neurotrauma

Trauma patients are at high risk of cervical and associated injuries. The standard protocol includes immobilization of the cervical spine in a polytrauma as it will help to prevent spinal injuries in the prehospital settings. Hard cervical collar (or alternatives) is routinely used until the cervical spine clearance is obtained . In patients with traumatic brain injury avoiding any kind of maneuver may lead to increased intracranial pressure

Entorno complementario al aprendizaje del sistema osteológico del equino

En los últimos años, los entornos virtuales educativos experimentaron un gran desarrollo. Se presenta una aplicación educativa interactiva que brinda información sobre la osteología del equino, uno de los temas que se dicta en la cátedra "Anatomía Comparada I" correspondiente al primer año de la carrera de Veterinaria (UNNE).Red de Universidades con Carreras en Informática (RedUNCI

Entorno complementario al aprendizaje del sistema osteológico del equino

En los últimos años, los entornos virtuales educativos experimentaron un gran desarrollo. Se presenta una aplicación educativa interactiva que brinda información sobre la osteología del equino, uno de los temas que se dicta en la cátedra "Anatomía Comparada I" correspondiente al primer año de la carrera de Veterinaria (UNNE).Red de Universidades con Carreras en Informática (RedUNCI

Using BOX-PCR to exclude a clonal outbreak of melioidosis

Background Although melioidosis in endemic regions is usually caused by a diverse range of Burkholderia pseudomallei strains, clonal outbreaks from contaminated potable water have been described. Furthermore B. pseudomallei is classified as a CDC Group B bioterrorism agent. Ribotyping, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) have been used to identify genetically related B. pseudomallei isolates, but they are time consuming and technically challenging for many laboratories. Methods We have adapted repetitive sequence typing using a BOX A1R primer for typing B. pseudomallei and compared BOX-PCR fingerprinting results on a wide range of well-characterized B. pseudomallei isolates with MLST and PFGE performed on the same isolates. Results BOX-PCR typing compared favourably with MLST and PFGE performed on the same isolates, both discriminating between the majority of multilocus sequence types and showing relatedness between epidemiologically linked isolates from various outbreak clusters. Conclusion Our results suggest that BOX-PCR can be used to exclude a clonal outbreak of melioidosis within 10 hours of receiving the bacterial strains

Numerical evaluation on shell buckling of empty thin-walled steel tanks under wind load according to current American and European design codes

Liquid storage steel tanks are vertical above-ground cylindrical shells and as typical thin-walled structures, they are very sensitive to buckling under wind loads, especially when they are empty or at low liquid level. Previous studies revealed discrepancies in buckling resistance of empty tanks between the design method proposed by the American Standard API 650 and the analytical formulas recommended by the European Standard EN1993-1-6 and EN1993-4-2. This study presents a comparison between the provisions of current design codes by performing all types of numerical buckling analyses recommended by Eurocodes (i.e. LBA-linear elastic bifurcation analysis, GNA-geometrically nonlinear elastic analysis of the perfect tank and GNIA-geometrically nonlinear elastic analysis of the imperfect tank). Such analyses are performed in order to evaluate the buckling resistance of two existing thin-walled steel tanks, with large diameters and variable wall thickness. In addition, a discussion is unfolded about the differences between computational and analytical methods and the conservatism that the latter method imposes. An influence study on the geometric imperfections and the boundary conditions is also conducted. Investigation on the boundary conditions at the foot of the tank highlights the sensitivity to the fixation of the vertical translational degree of freedom. Further, it is indicated that the imperfection magnitude recommended by the EN1993-1-6 is extremely unfavorable when applied to large diameter tanks. Comments and conclusions achieved could be helpful in order to evaluate the safety of the current design codes and shed more light towards the most accurate one

Viability of zebrafish (Danio rerio) ovarian follicles after vitrification in a metal container.

Cryopreservation of ovarian tissue has been studied for female germline preservation of farm animals and endangered mammalian species. However, there are relatively few reports on cryopreservation of fish ovarian tissue and especially using vitrification approach. Previous studies of our group has shown that the use of a metal container for the cryopreservation of bovine ovarian fragments results in good primordial and primary follicle morphological integrity after vitrification. The aim of this study was to assess the viability and in vitro development of zebrafish follicles after vitrification of fragmented or whole ovaries using the same metal container. In Experiment 1, we tested the follicular viability of five developmental stages following vitrification in four vitrification solutions using fluorescein diacetate and propidium iodide fluorescent probes. These results showed that the highest viability rates were obtained with immature follicles (Stage I) and VS1 (1.5 M methanol + 4.5 M propylene glycol). In Experiment 2, we used VS1 to vitrify different types of ovarian tissue (fragments or whole ovaries) in two different carriers (plastic cryotube or metal container). In this experiment, Stage I follicle survival was assessed following vitrification by vital staining after 24 h in vitro culture. Follicular morphology was analyzed by light microscopy after vitrification. Data showed that the immature follicles morphology was well preserved after cryopreservation. Follicular survival rate was higher (P < 0.05) in vitrified fragments, when compared to whole ovaries. There were no significant differences in follicular survival and growth when the two vitrification devices were compared