Developing fish community based ecohydrological indicators for water resources management in Taiwan

With concerns about the maintenance of both aquatic communities and flow conditions, a number of hydrologic indicators have been developed. These indicators are generally based on the development of hydrologic statistics for flows that are important to the maintenance of aquatic ecosystems. Although the hydrologic basis for indicators is well defined by common techniques in stochastic hydrology, the basis for ecological integration is still being developed. A critical evaluation of hydrologic indicators intended to protect aquatic ecosystems finds that proposed indicators are based more on standard hydrologic statistics and measures of hydrologic alteration than the habitat needs and ecological requirements of local or desired aquatic communities. We argue that hydrologic indicators are not ecohydrological indicators unless direct connections between flow events and aquatic community habitat and ecological needs are the basis of the indicator development and selection. In this article, we identify ecohydrological indicators that are based on habitat and ecological needs of fish communities. The indicator identification process is initiated with the analysis of community needs using an autecology matrix. Hydrologic statistics are then selected that are appropriate to the target fish community. The resulting ecohydrological indicators provide a direct connection to fish community flow requirements and the physical habitat conditions and associated ecology and life history needs of fish species. Handling editor: J. A. Cambray     

Developing genomic resources in two Linum species via 454 pyrosequencing and genomic reduction

Recent advances in next-generation DNA sequencing (NGS) have enhanced the development of genomic resources such as contigs or single-nucleotide polymorphisms (SNPs) for evolutionary studies of a nonmodel species with a complex and unsequenced genome. This study presents an application of a NGS technique in combination with genomic reduction and advanced bioinformatics tools to identify contigs and SNPs from multiple samples of two Linum species. A full Roche 454 GS FLX run of 16 diverse Linum samples representing cultivated flax (Linum usitatissimum L.) and its wild progenitor (Linum bienne Mill.) generated approximately 1.6 million sequence reads with a total length of 498 Mbp. Application of the computational pipeline de novo identification of alleles identified 713 contigs and 1067 SNPs. A blast search revealed alignments of all 713 contigs with 491 existing Linum scaffolds and gene annotations associated with 512 contigs. Sanger sequencing confirmed 95% of 79 selected contigs and 94% of 272 SNPs and identified 211 new SNPs and 19 new indels. The scored 454 SNP data were highly imbalanced for assayed samples. These findings not only are useful for evolutionary studies of Linum species but also help to illustrate the utility of NGS technologies in SNP discovery for nonmodel organisms.     

Ventilation of an additional dead space

The authors studied the question of the completeness of ventilation of an additional dead space in the form of a tube 3 cm in diameter and with a volume of 600 ml. Seven young volunteers were examined while breathing with and without the tube, seated at rest and during a two-grade exercise load on a bicycle ergometer. The criterion of ventilation of the tube was enlargement of the dead space by 600 ml during breathing through the tube. The functional dead space was always calculated from the tidal volume and the CO2 concentration in mixed expired air and in an end-tidal sample, using the Bohr equation. In every case, the tube was found to be completely ventilated by breathing, both under resting conditions and during exercise. In breathing during the bicycle exercise, the ratio of the functional dead space to tidal volume fell from 0.3 to 0.19 and a similar decrease was recorded in breathing through the tube.     

Synthesis of nucleosides with additional nucleobases

The syntheses of two nucleosides with additional nucleobases in the 2'-position are presented. The nucleosides have two- and one-carbon linkers to the additional nucleobase, respectively. The two nucleosides are synthesized from different strategies. The nucleoside with two carbons in the linker has been incorporated into oligonucleotides and showed stabilization of a tree-way junction.