482 research outputs found
Chloroplast phosphoproteins: regulation of excitation energy transfer by phosphorylation of thylakoid membrane polypeptides.
Phylogenomics of the adaptive radiation of Triturus newts supports gradual ecological niche expansion towards an incrementally aquatic lifestyle
Newts of the genus Triturus (marbled and crested newts) exhibit substantial variation in the number of trunk vertebrae (NTV) and a higher NTV corresponds to a longer annual aquatic period. Because the Triturus phylogeny has thwarted resolution to date, the evolutionary history of NTV, annual aquatic period, and their potential coevolution has remained unclear. To resolve the phylogeny of Triturus, we generated a c. 6,000 transcriptome-derived marker data set using a custom target enrichment probe set, and conducted phylogenetic analyses using: 1) data concatenation with RAxML, 2) gene-tree summary with ASTRAL, and 3) species-tree estimation with SNAPP. All analyses produce the same, highly supported topology, despite cladogenesis having occurred over a short timeframe, resulting in short internal branch lengths. Our new phylogenetic hypothesis is consistent with the minimal number of inferred changes in NTV count necessary to explain the diversity in NTV observed today. Although a causal relationship between NTV, body form, and aquatic ecology has yet to be experimentally established, our phylogeny indicates that these features have evolved together, and suggest that they may underlie the adaptive radiation that characterizes Triturus
En kvalitativ studie av hvordan toppledere forholder seg nĂĄr #metoo blir tema i norsk samfunnsliv.
Masteroppgave i kunnskapsledelse (MKL) - Nord universitet 201
Parallel tagged amplicon sequencing of transcriptome-based genetic markers for Triturus newts with the Ion Torrent next-generation sequencing platform
Next-generation sequencing is a fast and cost-effective way to obtain sequence data for nonmodel organisms for many markers and for many individuals. We describe a protocol through which we obtain orthologous markers for the crested newts (Amphibia: Salamandridae: Triturus), suitable for analysis of interspecific hybridization. We use transcriptome data of a single Triturus species and design 96 primer pairs that amplify c. 180 bp fragments positioned in 3-prime untranslated regions. Next, these markers are tested with uniplex PCR for a set of species spanning the taxonomical width of the genus Triturus. The 52 markers that consistently show a single band of expected length at gel electrophoreses for all tested crested newt species are then amplified in five multiplex PCRs (with a plexity of ten or eleven) for 132 individual newts: a set of 84 representing the seven (candidate) species and a set of 48 from a presumed hybrid population. After pooling multiplexes per individual, unique tags are ligated to link amplicons to individuals. Subsequently, individuals are pooled equimolar and sequenced on the Ion Torrent next-generation sequencing platform. A bioinformatics pipeline identifies the alleles and recodes these to a genotypic format. Next, we test the utility of our markers. baps allocates the 84 crested newt individuals representing (candidate) species to their expected (candidate) species, confirming the markers are suitable for species delineation. newhybrids, a hybrid index and hiest confirm the 48 individuals from the presumed hybrid population to be genetically admixed, illustrating the potential of the markers to identify interspecific hybridization. We expect the set of markers we designed to provide a high resolving power for analysis of hybridization in Triturus
Economic implications of open versus closed cycle cooling for new steam electric power plants : a national and regional survey
Originally published as the author's thesis (M.S.), M.I.T., Dept. of Civil Engineering, 1979.Current and anticipated thermal pollution regulations will prevent
many new steam electric power plants from operating with once-through
cooling. Alternative cooling systems acceptable from an environmental
view fail to operate with the same efficiencies, in terms of resources
consumed per Kwh of electricity produced, offered by once-through
cooling systems. As a consequence there are clear conflicts between
meeting environmental objectives and meeting minimum cost and minimum
resource consumption objectives. This report examines, at both the
regional and national level, the costs of satisfying environmental objec-
tives through the existing thermal pollution regulations.
This study forecasts the costs of operating those megawatts of
new generating capacity to be installed between the years 1975 and 2000
which will be required to install closed cycle cooling solely to
comply with thermal regulations. A regionally disaggregated approach
is used in the forecasts in order to preserve as much of the anticipated
inter-regional variation in future capacity growth rates and economic
trends as possible. The net costs of closed cycle cooling over once-
through cooling are based on comparisons of the costs of owning and
operating optimal closed and open-cycle cooling configurations in
separate regions, using computer codes to simulate joint power plant/
cooling system operation. The expected future costs of current thermal
pollution regulations are determined for the mutually exclusive -
collectively exhaustive eighteen Water Resources Council Regions within
the contiguous U.S., and are expressed in terms of additional dollar
expenditures, water losses and energy consumption. These costs are then
compared with the expected resource commitments associated with the
normal operation of the steam electric power industry. It is found that
while energy losses appear to be small, the dollar costs could threaten
the profitability of those utility systems which have historically used
once-through cooling extensively throughout their system. In addition
the additional water demands of closed cycle cooling are likely to disrupt
the water supplies in those coastal areas having few untapped freshwater
supplies available
Testing an hypothesis of hybrid zone movement for toads in France
Hybrid zone movement may result in substantial unidirectional introgression of selectively neutral material from the local to the advancing species, leaving a genetic footprint. This genetic footprint is represented by a trail of asymmetric tails and displaced cline centres in the wake of the moving hybrid zone. A peak of admixture linkage disequilibrium is predicted to exist ahead of the centre of the moving hybrid zone. We test these predictions of the movement hypothesis in a hybrid zone between common (Bufo bufo) and spined toads (B. spinosus), using 31 nuclear and one mtDNA SNPs along a transect in the northwest of France. Average effective selection in Bufo hybrids is low and clines vary in shape and centre. A weak pattern of asymmetric introgression is inferred from cline discordance of seven nuclear markers. The dominant direction of gene flow is from B. spinosus to B. bufo and is in support of southward movement of the hybrid zone. Conversely, a peak of admixture linkage disequilibrium north of the hybrid zone suggests northward movement. These contrasting results can be explained by reproductive isolation of the B. spinosus and B. bufo gene pools at the southern (B. spinosus) side of the hybrid zone. The joint occurrence of asymmetric introgression and admixture linkage disequilibrium can also be explained by the combination of low dispersal and random genetic drift due to low effective population sizes
Imaging in population science: cardiovascular magnetic resonance in 100,000 participants of UK Biobank - rationale, challenges and approaches
PMCID: PMC3668194SEP was directly funded by the National Institute for Health Research
Cardiovascular Biomedical Research Unit at Barts. SN acknowledges support
from the Oxford NIHR Biomedical Research Centre and from the Oxford
British Heart Foundation Centre of Research Excellence. SP and PL are
funded by a BHF Senior Clinical Research fellowship. RC is supported by a
BHF Research Chair and acknowledges the support of the Oxford BHF Centre
for Research Excellence and the MRC and Wellcome Trust. PMM gratefully
acknowledges training fellowships supporting his laboratory from the
Wellcome Trust, GlaxoSmithKline and the Medical Research Council
Two transects reveal remarkable variation in gene flow on opposite ends of a European toad hybrid zone
Microbial BiotechnologyAnimal science
- …