34 research outputs found
Recontextualising issues in the 'NISTCOL" environmental education curriculum module for Primary Diploma by Distance Learning in Zambia
This study investigated the recontextualising of the NISTCOL environmental education curriculum module for the Primary Teachersâ Diploma by Distance Learning (PTDDL) in Zambia. It focused on three case sites, the NISTCOL EE curriculum module for PTDDL and the University of Zambia, the National In-Service Teacherâs College (NISTCOL) and four basic schools: chalimbana, Bimbe, Chongwe and Silver Rest. The study looked at teacher professional development in environmental education in Zambia. The aims and goals were to investigate the NISTCOL EE curriculum and identifying issues that were associated with lecturers in the recontextualising process and further examine what issues were associated with curriculum recontextualisation in Zambian schools. For the conceptual constructs, the research drew on Bernsteinâs (1990) framework of pedagogic discourse, it traced how the pedagogic discourse was de-located from the field of production and re-located into the pedagogic practice of each stated case above. It further examined the continuities, discontinuities and changes in the official environmental discourse as it was recontextualised. The study particularly focused on Bernsteinâs conceptual constructs of selective appropriation and ideological transformation. In each case the Bernstein framework is used to analyze the process to identify recontextualising issues influencing pedagogical practice in the Zambian schools and college. The study revealed that each case under focus was unique but through examining the environmental discourse and pedagogical discourse in each case recontextalising issues were identified. Each case was influenced by different factors, such as lack of policy synergy, lack of EE vision at national level in Zambia, experience and knowledge, ideologies and emphasis, and depth of engagement. These factors provided me with a deeper insight into the curriculum recontextualising processes in Zambian schools
A framework genetic map for \u3ci\u3eMiscanthus sinensis\u3c/i\u3e from RNAseq-based markers shows recent tetraploidy
Background: Miscanthus (subtribe Saccharinae, tribe Andropogoneae, family Poaceae) is a genus of temperate perennial C4 grasses whose high biomass production makes it, along with its close relatives sugarcane and sorghum, attractive as a biofuel feedstock. The base chromosome number of Miscanthus (x = 19) is different from that of other Saccharinae and approximately twice that of the related Sorghum bicolor (x = 10), suggesting largescale duplications may have occurred in recent ancestors of Miscanthus. Owing to the complexity of the Miscanthus genome and the complications of self-incompatibility, a complete genetic map with a high density of markers has not yet been developed.
Results: We used deep transcriptome sequencing (RNAseq) from two M. sinensis accessions to define 1536 single nucleotide variants (SNVs) for a GoldenGateâą genotyping array, and found that simple sequence repeat (SSR) markers defined in sugarcane are often informative in M. sinensis. A total of 658 SNP and 210 SSR markers were validated via segregation in a full sibling F1 mapping population. Using 221 progeny from this mapping population, we constructed a genetic map for M. sinensis that resolves into 19 linkage groups, the haploid chromosome number expected from cytological evidence. Comparative genomic analysis documents a genomewide duplication in Miscanthus relative to Sorghum bicolor, with subsequent insertional fusion of a pair of chromosomes. The utility of the map is confirmed by the identification of two paralogous C4-pyruvate, phosphate dikinase (C4-PPDK) loci in Miscanthus, at positions syntenic to the single orthologous gene in Sorghum.
Conclusions: The genus Miscanthus experienced an ancestral tetraploidy and chromosome fusion prior to its diversification, but after its divergence from the closely related sugarcane clade. The recent timing of this tetraploidy complicates discovery and mapping of genetic markers for Miscanthus species, since alleles and fixed differences between paralogs are comparable. These difficulties can be overcome by careful analysis of segregation patterns in a mapping population and genotyping of doubled haploids. The genetic map for Miscanthus will be useful in biological discovery and breeding efforts to improve this emerging biofuel crop, and also provide a valuable resource for understanding genomic responses to tetraploidy and chromosome fusion
A framework genetic map for Miscanthus sinensis from RNAseq-based markers shows recent tetraploidy
Abstract Background Miscanthus (subtribe Saccharinae, tribe Andropogoneae, family Poaceae) is a genus of temperate perennial C4 grasses whose high biomass production makes it, along with its close relatives sugarcane and sorghum, attractive as a biofuel feedstock. The base chromosome number of Miscanthus (x = 19) is different from that of other Saccharinae and approximately twice that of the related Sorghum bicolor (x = 10), suggesting large-scale duplications may have occurred in recent ancestors of Miscanthus. Owing to the complexity of the Miscanthus genome and the complications of self-incompatibility, a complete genetic map with a high density of markers has not yet been developed. Results We used deep transcriptome sequencing (RNAseq) from two M. sinensis accessions to define 1536 single nucleotide variants (SNVs) for a GoldenGateâą genotyping array, and found that simple sequence repeat (SSR) markers defined in sugarcane are often informative in M. sinensis. A total of 658 SNP and 210 SSR markers were validated via segregation in a full sibling F1 mapping population. Using 221 progeny from this mapping population, we constructed a genetic map for M. sinensis that resolves into 19 linkage groups, the haploid chromosome number expected from cytological evidence. Comparative genomic analysis documents a genome-wide duplication in Miscanthus relative to Sorghum bicolor, with subsequent insertional fusion of a pair of chromosomes. The utility of the map is confirmed by the identification of two paralogous C4-pyruvate, phosphate dikinase (C4-PPDK) loci in Miscanthus, at positions syntenic to the single orthologous gene in Sorghum. Conclusions The genus Miscanthus experienced an ancestral tetraploidy and chromosome fusion prior to its diversification, but after its divergence from the closely related sugarcane clade. The recent timing of this tetraploidy complicates discovery and mapping of genetic markers for Miscanthus species, since alleles and fixed differences between paralogs are comparable. These difficulties can be overcome by careful analysis of segregation patterns in a mapping population and genotyping of doubled haploids. The genetic map for Miscanthus will be useful in biological discovery and breeding efforts to improve this emerging biofuel crop, and also provide a valuable resource for understanding genomic responses to tetraploidy and chromosome fusion
Microcollinearity between autopolyploid sugarcane and diploid sorghum genomes
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Sugarcane (Saccharum spp.) has become an increasingly important crop for its leading role in biofuel production. The high sugar content species S. officinarum is an octoploid without known diploid or tetraploid progenitors. Commercial sugarcane cultivars are hybrids between S. officinarum and wild species S. spontaneum with ploidy at ~12Ă. The complex autopolyploid sugarcane genome has not been characterized at the DNA sequence level.\ud
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The microsynteny between sugarcane and sorghum was assessed by comparing 454 pyrosequences of 20 sugarcane bacterial artificial chromosomes (BACs) with sorghum sequences. These 20 BACs were selected by hybridization of 1961 single copy sorghum overgo probes to the sugarcane BAC library with one sugarcane BAC corresponding to each of the 20 sorghum chromosome arms. The genic regions of the sugarcane BACs shared an average of 95.2% sequence identity with sorghum, and the sorghum genome was used as a template to order sequence contigs covering 78.2% of the 20 BAC sequences. About 53.1% of the sugarcane BAC sequences are aligned with sorghum sequence. The unaligned regions contain non-coding and repetitive sequences. Within the aligned sequences, 209 genes were annotated in sugarcane and 202 in sorghum. Seventeen genes appeared to be sugarcane-specific and all validated by sugarcane ESTs, while 12 appeared sorghum-specific but only one validated by sorghum ESTs. Twelve of the 17 sugarcane-specific genes have no match in the non-redundant protein database in GenBank, perhaps encoding proteins for sugarcane-specific processes. The sorghum orthologous regions appeared to have expanded relative to sugarcane, mostly by the increase of retrotransposons.\ud
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The sugarcane and sorghum genomes are mostly collinear in the genic regions, and the sorghum genome can be used as a template for assembling much of the genic DNA of the autopolyploid sugarcane genome. The comparable gene density between sugarcane BACs and corresponding sorghum sequences defied the notion that polyploidy species might have faster pace of gene loss due to the redundancy of multiple alleles at each locus.We acknowledge our colleagues at the University of Oklahomas Advanced Center for Genome Technology, Chunmei Qu and Ping Wang for their assistance with 454 GSFLX sequencing sample preparation and Steve Kenton for his help with deconvoluting the pooled BACs and their subsequent assembly. We also thank Eric Tang for assistance on sequencing two BACs using Sanger sequencers. This project is supported by startup funds from the University of Illinois to RM and a grant from the Energy Bioscience Institute (EBI) to SPM, MEH, RM, and DSR.We acknowledge our colleagues at the University of Oklahoma's Advanced Center for Genome Technology, Chunmei Qu and Ping Wang for their assistance with 454 GS-FLX sequencing sample preparation and Steve Kenton for his help with deconvoluting the pooled BACs and their subsequent assembly. We also thank Eric Tang for assistance on sequencing two BACs using Sanger sequencers. This project is supported by start-up funds from the University of Illinois to RM and a grant from the Energy Bioscience Institute (EBI) to SPM, MEH, RM, and DSR
Genome biology of the paleotetraploid perennial biomass crop Miscanthus
Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. x giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses
Characteristic trajectories of generalized Lanchester equations
http://archive.org/details/characteristictr00wozeN
Unclassified the Naval Postgraduate School GBS testbed
A downlink testbed for the Global Broadcast System (GBS) has been installed at the Naval Postgraduate School in the NPS Systems Technology Laboratory (STL). The purpose of the testbed is to conduct research on the link characteristics of GBS broadcasts that can be received in Monterey. Currently, the GBS Conus transmission is a Ku-band signal from the uplink testbed at the Pentagon via the medium power SBS-6 satellite located at 79 degrees West. Beginning in 1998, UFO-8
high power GBS broadcasts at Ka- band will be
analyzed. In addition, the testbed receives and analyzes commercial Direct Wand Dish Net Ku- band broadcasts. The testbed has been instrumented to monitor carrier power levels and background noise levels for each of the active transponders. Statistical analysis of this data is planned to develop distributions
of C/No and Eb/No for the different transmissions. Values are compared with computed link budgets. Correlation with local meteorological measurements is
planned.. Bit error rate testing is included to evaluate receiver/decoder losses and to validate effects of variable data rate
John Big Moose Walker
https://egrove.olemiss.edu/bluesphoto_one/1401/thumbnail.jp