1,898 research outputs found
Shotgun Metagenomic Sequencing Revealed the Prebiotic Potential of a Fruit Juice Drink with Fermentable Fibres in Healthy Humans
Fibre-based dietary interventions are at the forefront of gut microbiome modulation research, with a wealth of 16S rRNA information to demonstrate the prebiotic effects of isolated fibres. However, there is a distinct lack of data relating to the effect of a combination of soluble and insoluble fibres in a convenient-to-consume fruit juice food matrix on gut microbiota structure, diversity, and function. Here, we aimed to determine the impact of the MOJU Prebiotic Shot, an apple, lemon, ginger, and raspberry fruit juice drink blend containing chicory inulin, baobab, golden kiwi, and green banana powders, on gut microbiota structure and function. Healthy adults (n = 20) were included in a randomised, double-blind, placebo-controlled, cross-over study, receiving 60 mL MOJU Prebiotic Shot or placebo (without the fibre mix) for 3 weeks with a 3-week washout period between interventions. Shotgun metagenomics revealed significant between-group differences in alpha and beta diversity. In addition, the relative abundance of the phyla Actinobacteria and Desulfobacteria was significantly increased as a result of the prebiotic intervention. Nine species were observed to be differentially abundant (uncorrected p-value of <0.05) as a result of the prebiotic treatment. Of these, Bifidobacterium adolescentis and CAG-81 sp900066785 (Lachnospiraceae) were present at increased abundance relative to baseline. Additionally, KEGG analysis showed an increased abundance in pathways associated with arginine biosynthesis and phenylacetate degradation during the prebiotic treatment. Our results show the effects of the daily consumption of 60 mL MOJU Prebiotic Shot for 3 weeks and provide insight into the functional potential of B. adolescentis
The impact of the port of Durban on the city's road network
This study answers two key questions i.e. what is the volume of freight traffic generated by the Port of Durban and its overall distribution and what impact does the Port of Durban have on the City?s road network. This was achieved by quantifying the road based volumes (specifically heavy vehicle trips) based on Transnet?s Freight Demand Forecasts at the Port of Durban.
The freight distribution patterns from the Port of Durban were then investigated. Finally, the impacts and costs the Freight Demand Forecasts from the Port of Durban have on the City?s (Durban) road network were investigated. The costs included accidents costs, environmental costs, congestion costs and infrastructure costs.
The complex interaction of freight movement around ports can often be overlooked or misunderstood. This then leads to inefficiencies, inequalities, inadequate funding and unsustainability. It is thus imperative that planning authorities fully understand the multitude of port interactions, movements and impacts so that proper frameworks and policies can be established by all stakeholders to deal with ports.Paper presented at the 35th Annual Southern African Transport Conference 4-7 July 2016 "Transport ? a catalyst for socio-economic
growth and development opportunities to improve quality of life", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US
Influence of the charge carrier tunneling processes on the recombination dynamics in single lateral quantum dot molecules
We report on the charge carrier dynamics in single lateral quantum dot
molecules and the effect of an applied electric field on the molecular states.
Controllable electron tunneling manifests itself in a deviation from the
typical excitonic decay behavior which is strongly influenced by the tuning
electric field and inter-molecular Coulomb energies. A rate equation model is
developed to gain more insight into the charge transfer and tunneling
mechanisms. Non-resonant (phonon-mediated) electron tunneling which changes the
molecular exciton character from direct to indirect, and vice versa, is found
to be the dominant tunable decay mechanism of excitons besides radiative
recombination.Comment: 4 pages, 4 figure
Experimental imaging and atomistic modeling of electron and hole quasiparticle wave functions in InAs/GaAs quantum dots
We present experimental magnetotunneling results and atomistic
pseudopotential calculations of quasiparticle electron and hole wave functions
of self-assembled InAs/GaAs quantum dots. The combination of a predictive
theory along with the experimental results allows us to gain direct insight
into the quantum states. We monitor the effects of (i) correlations, (ii)
atomistic symmetry and (iii) piezoelectricity on the confined carriers and (iv)
observe a peculiar charging sequence of holes that violates the Aufbau
principle.Comment: Submitted to Physical Review B. A version of this paper with figures
can be found at http://www.sst.nrel.gov/nano_pub/mts_preprint.pd
Germ-furrow morphology and storage conditions determine the degree of viability of Pinus caribaea pollen
This study has found a correlation between Pinus caribaea pollen morphology and viability. Eighteen different P. caribaea pollen families were screened to determine the effect of environmental conditions during storage on germination. The results indicated that there was a direct decrease in viability with an increase in the age of the pollen, temperature at which the pollen was stored, and exposure to high humidity during storage. Scanning electron microscopy was used to investigate the dimensions of the 18 families. Upon statistical analysis of the dimensional data, the families were found to group into three clusters. Pollen families displaying narrow germ furrows clustered with those displaying wide germ furrows, while those pollen families displaying intermediate germ furrows clustered into a second group. When the clusters were compared with the germination data obtained it was found that the pollen families displaying highest germination percentages fell into the intermediate cluster, while the pollen families displaying low to intermediate germination percentages fell into the narrow/wide cluster
Collateral and Debt Maturity Choice. A Signaling Model
This paper derives optimal loan policies under asymmetric information where banks offer loan contracts of long and short duration, backed or unbacked with collateral. The main novelty of the paper is that it analyzes a setting in which high quality firms use collateral as a complementary device along with debt maturity to signal their superiority. The least-cost signaling equilibrium depends on the relative costs of the signaling devices, the difference in firm quality and the proportion of good firms in the market. Model simulations suggest a non-monotonic relationship between firm quality and debt maturity, in which high quality firms have both long-term secured debt and short-term secured or non-secured debt.
Recent advances in exciton based quantum information processing in quantum dot nanostructures
Recent experimental developments in the field of semiconductor quantum dot
spectroscopy will be discussed. First we report about single quantum dot
exciton two-level systems and their coherent properties in terms of single
qubit manipulations. In the second part we report on coherent quantum coupling
in a prototype "two-qubit" system consisting of a vertically stacked pair of
quantum dots. The interaction can be tuned in such quantum dot molecule devices
using an applied voltage as external parameter.Comment: 37 pages, 15 figures, submitted to New Journal of Physics, focus
issue on Solid State Quantum Information, added reference
Rates of species introduction to a remote oceanic island
The introduction of species to areas beyond the limits of their natural distributions has a major homogenizing influence, making previously distinct biotas more similar. The scale of introductions has frequently been commented on, but their rate and spatial pervasiveness have been less well quantified. Here, we report the findings of a detailed study of pterygote insect introductions to Gough Island, one of the most remote and supposedly pristine temperate oceanic islands, and estimate the rate at which introduced species have successfully established.
Out of 99 species recorded from Gough Island, 71 are established introductions, the highest proportion documented for any Southern Ocean island. Estimating a total of approximately 233 landings on Gough Island since first human landfall, this equates to one successful establishment for every three to four landings. Generalizations drawn from other areas suggest that this may be only one-tenth of the number of pterygote species that have arrived at the island, implying that most landings may lead to the arrival of at least one alien. These rates of introduction of new species are estimated to be two to three orders of magnitude greater than background levels for Gough Island, an increase comparable to that estimated for global species extinctions (many of which occur on islands) as a consequence of human activities
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