title: Wanted dead or alive? Using metabarcoding of environmental DNA and RNA to distinguish living assemblages for biosecurity applications

authors: Pochon, Xavier

subjects: Science & Technology

abstract: High-throughput sequencing metabarcoding studies in marine biosecurity have largely focused on targeting environmental DNA (eDNA). DNA can persist extracellularly in the environment, making discrimination of living organisms difficult. In this study, bilge water samples (i.e., water accumulating on-board a vessel during transit) were collected from 15 small recreational and commercial vessels. eDNA and eRNA molecules were co-extracted and the V4 region of the 18S ribosomal RNA gene targeted for metabarcoding. In total, 62.7% of the Operational Taxonomic Units (OTUs) were identified at least once in the corresponding eDNA and eRNA reads, with 19.5% unique to eDNA and 17.7% to eRNA. There were substantial differences in diversity between molecular compartments; 57% of sequences from eDNA-only OTUs belonged to fungi, likely originating from legacy DNA. In contrast, there was a higher percentage of metazoan (50.2%) and ciliate (31.7%) sequences in the eRNA-only OTUs. Our data suggest that the presence of eRNA-only OTUs could be due to increased cellular activities of some rare taxa that were not identified in the eDNA datasets, unusually high numbers of rRNA transcripts in ciliates, and/or artefacts produced during the reverse transcriptase, PCR and sequencing steps. The proportions of eDNA/eRNA shared and unshared OTUs were highly heterogeneous within individual bilge water samples. Multiple factors including boat type and the activities performed on-board, such as washing of scientific equipment, may play a major role in contributing to this variability. For some marine biosecurity applications analysis, eDNA-only data may be sufficient, however there are an increasing number of instances where distinguishing the living portion of a community is essential. For these circumstances, we suggest only including OTUs that are present in both eDNA and eRNA data. OTUs found only in the eRNA data need to be interpreted with caution until further research provides conclusive evidence for their origin.

text: Wanted dead or alive? Using metabarcoding of environmental DNA and RNA to distinguish living assemblages for biosecurity applications High-throughput sequencing metabarcoding studies in marine biosecurity have largely focused on targeting environmental DNA (eDNA). DNA can persist extracellularly in the environment, making discrimination of living organisms difficult. In this study, bilge water samples (i.e., water accumulating on-board a vessel during transit) were collected from 15 small recreational and commercial vessels. eDNA and eRNA molecules were co-extracted and the V4 region of the 18S ribosomal RNA gene targeted for metabarcoding. In total, 62.7% of the Operational Taxonomic Units (OTUs) were identified at least once in the corresponding eDNA and eRNA reads, with 19.5% unique to eDNA and 17.7% to eRNA. There were substantial differences in diversity between molecular compartments; 57% of sequences from eDNA-only OTUs belonged to fungi, likely originating from legacy DNA. In contrast, there was a higher percentage of metazoan (50.2%) and ciliate (31.7%) sequences in the eRNA-only OTUs. Our data suggest that the presence of eRNA-only OTUs could be due to increased cellular activities of some rare taxa that were not identified in the eDNA datasets, unusually high numbers of rRNA transcripts in ciliates, and/or artefacts produced during the reverse transcriptase, PCR and sequencing steps. The proportions of eDNA/eRNA shared and unshared OTUs were highly heterogeneous within individual bilge water samples. Multiple factors including boat type and the activities performed on-board, such as washing of scientific equipment, may play a major role in contributing to this variability. For some marine biosecurity applications analysis, eDNA-only data may be sufficient, however there are an increasing number of instances where distinguishing the living portion of a community is essential. For these circumstances, we suggest only including OTUs that are present in both eDNA and eRNA data. OTUs found only in the eRNA data need to be interpreted with caution until further research provides conclusive evidence for their origin.

year: 2017

title: The impact on language teachers of trends in the literature on language teaching and learning: A questionnaire-based study involving teachers of English as an additional language

authors: Fester, Anthea

subjects: Language teachers

abstract: The article reports about the research on teachers of English language as an Additional Language in five countries. As mentioned, a questionnaire including questions about genre, cohesion and coherence of teaching was prepared, it revealed that the language had less impact on beliefs and practices of these language teachers, and that too only a superficial one. Several illustrative diagrams are in the article, and it's concluded that teaching English has less impact on teaching of other languages.

text: The impact on language teachers of trends in the literature on language teaching and learning: A questionnaire-based study involving teachers of English as an additional language The article reports about the research on teachers of English language as an Additional Language in five countries. As mentioned, a questionnaire including questions about genre, cohesion and coherence of teaching was prepared, it revealed that the language had less impact on beliefs and practices of these language teachers, and that too only a superficial one. Several illustrative diagrams are in the article, and it's concluded that teaching English has less impact on teaching of other languages.

year: 2010-09

title: Prismatic storying: Making visible multi coloured codes

authors: Stuart, Margaret J.

abstract: Language is a casement into cultures' deepest meanings. As children acquire languages, they implicitly adopt the mores of people around them; read the symbols, artefacts and codes. In this article, we examine the importance of language and literacy in the early childhood curriculum Te Whariki: He Whariki Matauranga mo nga Mokopuna o Aotearoa/Early Childhood Curriculum (Ministry of Education, 1996). The focus of the article is on literacy from a bicultural perspective. Adults support children in finding out about both their social and physical worlds. They use their 'imaginations to explore their own and others' identities' (MoE, 1996, p. 25). Our aim is to offer teachers in mainstream early childhood centres (ECE) strategies to apply, practise and situate literacy approaches that reflect Te Ao Maori through stories reflecting symbolic representations of people, places and things.

text: Prismatic storying: Making visible multi coloured codes Language is a casement into cultures' deepest meanings. As children acquire languages, they implicitly adopt the mores of people around them; read the symbols, artefacts and codes. In this article, we examine the importance of language and literacy in the early childhood curriculum Te Whariki: He Whariki Matauranga mo nga Mokopuna o Aotearoa/Early Childhood Curriculum (Ministry of Education, 1996). The focus of the article is on literacy from a bicultural perspective. Adults support children in finding out about both their social and physical worlds. They use their 'imaginations to explore their own and others' identities' (MoE, 1996, p. 25). Our aim is to offer teachers in mainstream early childhood centres (ECE) strategies to apply, practise and situate literacy approaches that reflect Te Ao Maori through stories reflecting symbolic representations of people, places and things.

year: 2018