Molecular analysis of Acipenser sturio L., 1758 and Acipenser oxyrinchus Mitchill, 1815: A review

Molecular phylogeny based on the analysis of partial sequences of mitochondrial (mt) cytochrome b (cyt b), 12S, and 16S genes supports a close relationship between the European Atlantic sturgeon Acipenser sturio L., 1758, and the American Atlantic sturgeon, Acipenser oxyrinchus Mitchill, 1815. These sister species form a separate clade within the genus Acipenser and appear to be the most basal clade with respect to all other species of the genus. Intraspecifically, at least two different genetic forms have been found within A. sturio (in the Northern and Baltic seas), but no defined subspecies exist. For A. oxyrinchus, fixed differences in the control region and cyt b gene distinguish the two subspecies, the Atlantic sturgeon A. oxyrinchus oxyrinchus Mitchill, 1815 and the Gulf of Mexico sturgeon A. oxyrinchus desotoi Vladykov, 1955. Within A. o. oxyrinchus, a pronounced latitudinal cline in haplotype diversity exists from north to south along the eastern coast of North America. This greater genetic diversity in southern populations is most likely a result of population continuity through the Pleistocene. Monomorphism within the two northernmost, post-Pleistocene A. o. oxyrinchus populations indicates a probable founder effect. A. o. desotoi also displays a significant geographic structuring of populations in different river systems. Because of the lack of A. sturio individuals necessary for population studies and the close relationship between this species and A. oxyrinchus, the genetic characteristics and structure of A. oxyrinchus can be regarded as a model for A. sturio. The only opportunity for future detailed molecular study of A. sturio resides in using tissue samples from sturgeon specimens kept in various European museums.La filogenia molecular basada en el análisis de secuencias parciales de los genes mitocondriales (mt) citocromo b (cyt b), 12S y 16S apoya la próxima relación entre el esturión atlántico europeo Acipenser sturio L., 1758 y el esturión atlántico americano Acipenser oxyrinchus Mitchill, 1815. Estas especies hermanas forman un clado separado dentro del género Acipenser y parecen constituir el clado más basal con relación a todas las otras especies del género. Intraespecíficamente se han encontrado, al menos, dos formas genéticas diferentes dentro de A. sturio (en los mares del Norte y Báltico) pero no existen subespecies definidas. Para A. oxyrinchus las diferencias fijadas en la región control y en el gen del cyt b distinguen las dos subespecies: el esturión atlántico A. oxyrinchus oxyrinchus Mitchill, 1815 y el esturión del golfo de México A. oxyrinchus desotoi Vladykov, 1955. Dentro de A. o. oxyrinchus existe un pronunciado cline latitudinal en la diversidad de haplotipos desde el norte hasta el sur a lo largo de la costa este de América del Norte. Esta mayor diversidad genética en las poblaciones meridionales es, más probablemente, un resultado de la continuidad poblacional durante el Pleistoceno. El monomorfismo dentro de las dos poblaciones post-pleistocénicas más septentrionales de A. o. oxyrinchus indica un probable efecto fundador. A. o. desotoi siempre muestra una significativa estructuración geográfica de poblaciones en diferentes sistemas fluviales. Debido a la falta de individuos de A. sturio necesarios para los estudios poblacionales y a la próxima relación entre esta especie y A. oxyrinchus, las características y estructura genéticas de A. oxyrinchus pueden ser consideradas como modelo para A. sturio. La única oportunidad para un futuro estudio molecular detallado de A. sturio reside en el uso de muestras de tejidos de ejemplares de esturión almacenados en varios museos europeos.Instituto Español de Oceanografí

Exploring TPACK among pre-service teachers in Australia and Israel

The ubiquitous nature of technology in the world has not yet translated into the ubiquitous use of technology to transform learning and teaching. Teachers lack the confidence and competence to integrate technology across a broad range of tools within a range of contexts. Technological Pedagogical Content Knowledge (TPACK) has become a common framework to explore technology within teaching and teacher education. However, little research exists to explore the similarities and differences of TPACK between different teacher education programs, within different countries or even different disciplines, especially in a secondary context. Using a self-report online survey, this study sought to compare and contrast TPACK results from pre-service teachers studying in secondary teacher education programs in Australia and Israel. Findings suggest that TPACK is higher in Australia, and in both countries for those students who were aged over 26. There were no significant differences between gender or disciplines reported. The paper also discusses broad-scale implications for the future of research in TPACK

Population structure, connectivity, and demographic history of an apex marine predator, the bull shark <i>Carcharhinus leucas</i>

Knowledge of population structure, connectivity, and effective population size remains limited for many marine apex predators, including the bull shark Carcharhinus leucas. This large‐bodied coastal shark is distributed worldwide in warm temperate and tropical waters, and uses estuaries and rivers as nurseries. As an apex predator, the bull shark likely plays a vital ecological role within marine food webs, but is at risk due to inshore habitat degradation and various fishing pressures. We investigated the bull shark\u27s global population structure and demographic history by analyzing the genetic diversity of 370 individuals from 11 different locations using 25 microsatellite loci and three mitochondrial genes (CR, nd4, and cytb). Both types of markers revealed clustering between sharks from the Western Atlantic and those from the Western Pacific and the Western Indian Ocean, with no contemporary gene flow. Microsatellite data suggested low differentiation between the Western Indian Ocean and the Western Pacific, but substantial differentiation was found using mitochondrial DNA. Integrating information from both types of markers and using Bayesian computation with a random forest procedure (ABC‐RF), this discordance was found to be due to a complete lack of contemporary gene flow. High genetic connectivity was found both within the Western Indian Ocean and within the Western Pacific. In conclusion, these results suggest important structuring of bull shark populations globally with important gene flow occurring along coastlines, highlighting the need for management and conservation plans on regional scales rather than oceanic basin scale

Measuring technological and content knowledge of undergraduate primary teachers in mathematics

Twenty-five final-year undergraduate students of primary education who were attending a course on mathematics education participated in a research project during the 2009 spring semester. A repeated measures experimental design was used. Quantitative data on students&apos; computer attitudes, self-efficacy in ICT, attitudes toward educational software, and self-efficacy in maths were collected. Data analysis showed a statistically non-significant improvement on participants&apos; computer attitudes and self-efficacy in ICT and ES, but a significant improvement of self-efficacy in mathematics. © 2010 Springer-Verlag Berlin Heidelberg

Researching technological and mathematical knowledge (TCK) of undergraduate primary teachers

Twenty-five final-year undergraduate students of primary education who were attending a six month course on mathematics education participated in a research project during the 2009 spring semester. A repeated measures experimental design was used. Quantitative data on students&apos; computer attitudes, self-efficacy in ICT, attitudes toward educational software, and self-efficacy in maths were collected. Data analysis showed a statistically non-significant improvement on participants&apos; computer attitudes and self-efficacy in ICT and educational software, but a significant improvement of self-efficacy in mathematics. In addition, it seemed that the crucial factors for the integration of educational software and scenarios into the teaching of mathematics are positive attitudes towards ICT - educational software and self-efficacy in technological tools and mathematics. Copyright © 2010 Inderscience Enterprises Ltd

Species and hybrid identification of sturgeon caviar: A new molecular approach to detect illegal trade

Overexploitation of wild populations due to the high economic value of caviar has driven sturgeons to near extinction. The high prices commanded by caviar on world markets have made it a magnet for illegal and fraudulent caviar trade, often involving low-value farmed caviar being sold as top-quality caviar. We present a new molecular approach for the identification of pure sturgeon species and hybrids that are among the most commercialized species in Europe and North America. Our test is based on the discovery of species-specific single nucleotide polymorphisms (SNPs) in the ribosomal protein S7, supplemented with the Vimentin gene and the mitochondrial D-loop. Test validations performed in 702 specimens of target and nontarget sturgeon species demonstrated a 100% identification success for Acipenser naccarii, A.fulvescens, A.stellatus, A.sinensis and A.transmontanus. In addition to species identification, our approach allows the identification of Bester and AL hybrids, two of the most economically important hybrids in the world, with 80% and 100% success, respectively. Moreover, the approach has the potential to identify many other existing sturgeon hybrids. The development of a standardized sturgeon identification tool will directly benefit trade law enforcement, providing the tools to monitor and regulate the legal trade of caviar and protect sturgeon stocks from illicit producers and traders, hence contributing to safeguarding this group of heavily threatened species

Data from: Species and hybrid identification of sturgeon caviar: a new molecular approach to detect illegal trade

Overexploitation of wild populations due to the high economic value of caviar has driven sturgeons to near extinction. The high prices commanded by caviar on world markets have made it a magnet for illegal and fraudulent caviar trade, often involving low-value farmed caviar being sold as top-quality caviar. We present a new molecular approach for the identification of pure sturgeon species and hybrids that are among the most commercialized species in Europe and North America. Our test is based on the discovery of species-specific single nucleotide polymorphisms (SNPs) in the ribosomal protein S7, supplemented with the Vimentin gene and the mitochondrial D-loop. Test validations performed in 702 specimens of target and nontarget sturgeon species demonstrated a 100% identification success for Acipenser naccarii, A. fulvescens, A. stellatus, A. sinensis and A. transmontanus. In addition to species identification, our approach allows the identification of Bester and AL hybrids, two of the most economically important hybrids in the world, with 80% and 100% success, respectively. Moreover, the approach has the potential to identify many other existing sturgeon hybrids. The development of a standardized sturgeon identification tool will directly benefit trade law enforcement, providing the tools to monitor and regulate the legal trade of caviar and protect sturgeon stocks from illicit producers and traders, hence contributing to safeguarding this group of heavily threatened species