1,064 research outputs found
Do Spin-Offs Make the Academics’ Heads Spin?: The Impacts of Spin-Off Companies on Their Parent Research Organisation
As public research organisations are increasingly driven by their national and regional governments to engage in knowledge transfer, they have started to support the creation of companies. These research based spin-off companies (RBSOs) often keep contacts with the research institutes they originate from. In this paper we present the results of a study of four research institutes within two universities and two non-university public research organisations (PROs) in the Netherlands. We show that research organisations have distinct motivations to support the creation of spin-off companies. In terms of resources RBSOs contribute, mostly in a modest way, to research activities by providing information, equipment and monetary resources. In particular, RBSOs are helpful for researchers competing for research grants that demand participation of industry. Furthermore, RBSOs may be seen as a proactive response by Dutch public research organisations to demands of economic relevance from their institutional environment. RBSOs enhance the prestige of their parent organisations and create legitimacy for public funds invested in PROs. At the same time, most RBSOs do not have a significant impact on the direction of the research conducted at the PROs
Spin dependent quantum interference in non-local graphene spin valves
Spin dependent electron transport measurements on graphene are of high
importance to explore possible spintronic applications. Up to date all spin
transport experiments on graphene were done in a semi-classical regime,
disregarding quantum transport properties such as phase coherence and
interference. Here we show that in a quantum coherent graphene nanostructure
the non-local voltage is strongly modulated. Using non-local measurements, we
separate the signal in spin dependent and spin independent contributions. We
show that the spin dependent contribution is about two orders of magnitude
larger than the spin independent one, when corrected for the finite
polarization of the electrodes. The non-local spin signal is not only strongly
modulated but also changes polarity as a function of the applied gate voltage.
By locally tuning the carrier density in the constriction we show that the
constriction plays a major role in this effect and indicates that it can act as
a spin filter device. Our results show the potential of quantum coherent
graphene nanostructures for the use in future spintronic devices
Electronic Spin Transport in Dual-Gated Bilayer Graphene
The elimination of extrinsic sources of spin relaxation is key in realizing
the exceptional intrinsic spin transport performance of graphene. Towards this,
we study charge and spin transport in bilayer graphene-based spin valve devices
fabricated in a new device architecture which allows us to make a comparative
study by separately investigating the roles of substrate and polymer residues
on spin relaxation. First, the comparison between spin valves fabricated on
SiO2 and BN substrates suggests that substrate-related charged impurities,
phonons and roughness do not limit the spin transport in current devices. Next,
the observation of a 5-fold enhancement in spin relaxation time in the
encapsulated device highlights the significance of polymer residues on spin
relaxation. We observe a spin relaxation length of ~ 10 um in the encapsulated
bilayer with a charge mobility of 24000 cm2/Vs. The carrier density dependence
of spin relaxation time has two distinct regimes; n<4 x 1012 cm-2, where spin
relaxation time decreases monotonically as carrier concentration increases, and
n>4 x 1012 cm-2, where spin relaxation time exhibits a sudden increase. The
sudden increase in the spin relaxation time with no corresponding signature in
the charge transport suggests the presence of a magnetic resonance close to the
charge neutrality point. We also demonstrate, for the first time, spin
transport across bipolar p-n junctions in our dual-gated device architecture
that fully integrates a sequence of encapsulated regions in its design. At low
temperatures, strong suppression of the spin signal was observed while a
transport gap was induced, which is interpreted as a novel manifestation of
impedance mismatch within the spin channel
Surfaces roughness effects on the transmission of Gaussian beams by anisotropic parallel plates
Influence of the plate surfaces roughness in precise ellipsometry experiments
is studied. The realistic case of a Gaussian laser beam crossing a uniaxial
platelet is considered. Expression for the transmittance is determined using
the first order perturbation theory. In this frame, it is shown that
interference takes place between the specular transmitted beam and the
scattered field. This effect is due to the angular distribution of the Gaussian
beam and is of first order in the roughness over wavelength ratio. As an
application, a numerical simulation of the effects of quartz roughness surfaces
at normal incidence is provided. The interference term is found to be strongly
connected to the random nature of the surface roughness.Comment: 18 pages, Journal of Physics D: Applied Physics, volume 36, issue 21,
pages 2697 - 270
The Equine Faecal Microbiota of Healthy Horses and Ponies in The Netherlands:Impact of Host and Environmental Factors
Several studies have described the faecal microbiota of horses and the factors that influence its composition, but the variation in results is substantial. This study aimed to investigate the microbiota composition in healthy equids in The Netherlands under standard housing and management conditions and to evaluate the effect of age, gender, horse type, diet, pasture access, the season of sampling and location on it. Spontaneously produced faecal samples were collected from the stall floor of 79 healthy horses and ponies at two farms. The validity of this sampling technique was evaluated in a small pilot study including five ponies showing that the microbiota composition of faecal samples collected up to 6 h after spontaneous defaecation was similar to that of the samples collected rectally. After DNA extraction, Illumina Miseq 16S rRNA sequencing was performed to determine microbiota composition. The effect of host and environmental factors on microbiota composition were determined using several techniques (NMDS, PERMANOVA, DESeq2). Bacteroidetes was the largest phylum found in the faecal microbiota (50.1%), followed by Firmicutes (28.4%). Alpha-diversity and richness decreased significantly with increasing age. Location, age, season, horse type and pasture access had a significant effect on beta-diversity. The current study provides important baseline information on variation in faecal microbiota in healthy horses and ponies under standard housing and management conditions. These results indicate that faecal microbiota composition is affected by several horse-related and environment-related factors, and these factors should be considered in future studies of the equine faecal microbiota
Genome-wide association studies of Shigella spp. and Enteroinvasive Escherichia coli isolates demonstrate an absence of genetic markers for prediction of disease severity
BACKGROUND: We investigated the association of symptoms and disease severity of shigellosis patients with genetic determinants of infecting Shigella and entero-invasive Escherichia coli (EIEC), because determinants that predict disease outcome per individual patient could be used to prioritize control measures. For this purpose, genome wide association studies (GWAS) were performed using presence or absence of single genes, combinations of genes, and k-mers. All genetic variants were derived from draft genome sequences of isolates from a multicenter cross-sectional study conducted in the Netherlands during 2016 and 2017. Clinical data of patients consisting of binary/dichotomous representation of symptoms and their calculated severity scores were also available from this study. To verify the suitability of the methods used, the genetic differences between the genera Shigella and Escherichia were used as control. RESULTS: The isolates obtained were representative of the population structure encountered in other Western European countries. No association was found between single genes or combinations of genes and separate symptoms or disease severity scores. Our benchmark characteristic, genus, resulted in eight associated genes and > 3,000,000 k-mers, indicating adequate performance of the algorithms used. CONCLUSIONS: To conclude, using several microbial GWAS methods, genetic variants in Shigella spp. and EIEC that can predict specific symptoms or a more severe course of disease were not identified, suggesting that disease severity of shigellosis is dependent on other factors than the genetic variation of the infecting bacteria. Specific genes or gene fragments of isolates from patients are unsuitable to predict outcomes and cannot be used for development, prioritization and optimization of guidelines for control measures of shigellosis or infections with EIEC
The role of soil carbon in natural climate solutions
Acknowledgements. This study was made possible by funding from the Craig and Susan McCaw Foundation. Data Deposition A global spatial dataset of reforestation opportunities is available on Zenodo (https://zenodo.org/record/883444). Figures 1 and 2 have associated raw data that can be made available upon request.Peer reviewedPostprin
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