1,637 research outputs found
Morphology of Vaccine RD&D translation
Translation as a concept coordinates participation in innovation but remains
a qualitative construct. We provide multivariate accounting of linkages between
market entries of vaccines, clinical trials, patents, publications, funders,
and grants to quantify biomedical translation. We found that the most prevalent
types of biomedical translation are those between basic and applied research
(52 percent) followed by those between research and product development (36
percent). Although many biomedical stakeholders assume knowledge flows one way
from upstream research to downstream application, knowledge feedbacks that
mediate translation are prevalent. We also cluster biomedical funders based on
the types of translations they fund. Large-scale funding agencies such as NIH
are similarly involved in early-stage translation, whereas pharmaceuticals and
mission-oriented agencies such as DARPA involve diverse translation types, and
each leaves different translation footprints
Modelling an energetic tidal strait:investigating implications of common numerical configuration choices
Representation of the marine environment is key for reliable coastal hydrodynamic models. This study investigates the implications of common depth-averaged model configuration choices in sufficiently characterising seabed geometry and roughness. In particular, applications requiring a high level of accuracy and/or exhibiting complex flow conditions may call for greater detail in marine environment representation than typically adopted in coastal models. Ramsey Sound, a macrotidal strait in Pembrokeshire, Wales, UK is considered as a case study. The site contains various steeply inclined bathymetric features, including a submerged pinnacle named Horse Rock and a rocky reef called âThe Bitchesâ. The available energy in Ramsey Soundâs tidal currents has attracted attention from tidal energy developers. There is interest in accurately modelling the energetic hydrodynamics surrounding its pronounced bathymetry. The coastal flow solver Thetis is applied to simulate the flow conditions in Ramsey Sound. It is shown that notable prominent bathymetric features in the strait influence localised and, most importantly, regional hydrodynamic characteristics. âThe Bitchesâ consistently accelerate flow in the strait while Horse Rock induces a notable wake structure and flow reversals. The model is calibrated against bed- and vessel-mounted Acoustic Doppler Current Profiler (ADCP) observations, by altering seabed roughness parameterisations. A spatially variable and locally scaled Manning coefficient based on diverse seabed classification observations is found to improve model performance in comparison to uniformly applied constants, the latter a more common approach. The local impact of altering the Manning coefficient configuration is found to be greatest during spring flood periods of high velocity currents. Meanwhile, the effect of coarsening the computational mesh around bathymetric features towards values more typically applied in coastal models is investigated. Results indicate severe misrepresentation of seabed geometry and subsequent wake hydrodynamics unless refined to a mesh element size that adequately represents Horse Rock and âThe Bitchesâ
Axisymmetric Three-Integral Models for Galaxies
We describe an improved, practical method for constructing galaxy models that
match an arbitrary set of observational constraints, without prior assumptions
about the phase-space distribution function (DF). Our method is an extension of
Schwarzschild's orbit superposition technique. As in Schwarzschild's original
implementation, we compute a representative library of orbits in a given
potential. We then project each orbit onto the space of observables, consisting
of position on the sky and line-of-sight velocity, while properly taking into
account seeing convolution and pixel binning. We find the combination of orbits
that produces a dynamical model that best fits the observed photometry and
kinematics of the galaxy. A key new element of this work is the ability to
predict and match to the data the full line-of-sight velocity profile shapes. A
dark component (such as a black hole and/or a dark halo) can easily be included
in the models.
We have tested our method, by using it to reconstruct the properties of a
two-integral model built with independent software. The test model is
reproduced satisfactorily, either with the regular orbits, or with the
two-integral components. This paper mainly deals with the technical aspects of
the method, while applications to the galaxies M32 and NGC 4342 are described
elsewhere (van der Marel et al., Cretton & van den Bosch). (abridged)Comment: minor changes, accepted for publication in the Astrophysical Journal
Supplement
Scalable Focused Ion Beam Creation of Nearly Lifetime-Limited Single Quantum Emitters in Diamond Nanostructures
The controlled creation of defect center---nanocavity systems is one of the
outstanding challenges for efficiently interfacing spin quantum memories with
photons for photon-based entanglement operations in a quantum network. Here, we
demonstrate direct, maskless creation of atom-like single silicon-vacancy (SiV)
centers in diamond nanostructures via focused ion beam implantation with nm lateral precision and nm positioning accuracy relative to a
nanocavity. Moreover, we determine the Si+ ion to SiV center conversion yield
to and observe a 10-fold conversion yield increase by additional
electron irradiation. We extract inhomogeneously broadened ensemble emission
linewidths of GHz, and close to lifetime-limited single-emitter
transition linewidths down to MHz corresponding to -times
the natural linewidth. This demonstration of deterministic creation of
optically coherent solid-state single quantum systems is an important step
towards development of scalable quantum optical devices
Outfoxing the fox: effect of prey odor on fox behavior in a pastoral landscape
Invasive mammalian predators have had a devastating effect on native species globally. The European red fox (Vulpes vulpes) is one such species where it has been introduced in Australia. A novel but unexplored tactic to reduce the impact of mammalian predators is the use of unrewarded prey odors to undermine the effectiveness of olfactory hunting behavior. To test the viability of unrewarded prey odors in an applied setting we investigated how foxes responded to the odors of three different prey species. We used the odors of two locally extinct native Australian marsupials; the eastern quoll (a smaller carnivore) and eastern bettong (a fungivore), and the European rabbit, an introduced herbivore. Conducting our research over a period of 3âweeks in a pastoral environment in South-eastern Australia, we used video observations of foxes' behaviors, as they encountered the different odors. We found a reduction in the number of fox visits to bettong odors in the third week. In contrast, we observed a sustained number of visits to rabbit odors. Foxes also spent more time investigating rabbit odors and displayed longer durations of vigilance behavior at quoll odors. Our results support the hypothesis that the exposure of wild foxes to unrewarded odors of novel prey species can reduce their interest in these odors, which might translate to a reduction in predation pressure. Our results also suggest, however, that olfactory pre-exposure may not be as effective at reducing fox interest in a competitor species' odor
Local dominance unveils clusters in networks
Clusters or communities can provide a coarse-grained description of complex
systems at multiple scales, but their detection remains challenging in
practice. Community detection methods often define communities as dense
subgraphs, or subgraphs with few connections in-between, via concepts such as
the cut, conductance, or modularity. Here we consider another perspective built
on the notion of local dominance, where low-degree nodes are assigned to the
basin of influence of high-degree nodes, and design an efficient algorithm
based on local information. Local dominance gives rises to community centers,
and uncovers local hierarchies in the network. Community centers have a larger
degree than their neighbors and are sufficiently distant from other centers.
The strength of our framework is demonstrated on synthesized and empirical
networks with ground-truth community labels. The notion of local dominance and
the associated asymmetric relations between nodes are not restricted to
community detection, and can be utilised in clustering problems, as we
illustrate on networks derived from vector data
Developmental biographies of Olympic super-elite and elite athletes â a multidisciplinary pattern recognition analysis
This multidisciplinary study used pattern recognition analyses to examine the developmental biographies of 16 Great British Olympic and World Champions (âSuper-Eliteâ) and 16 matched international athletes who had not won major medals (âEliteâ). Athlete, coach and parent interviews (260 total interview hours) combined in-depth qualitative and quantitative methods. A combination of demographics, psychosocial characteristics, coach and family relationships, practice, competition, and performance development discriminated Super-Elite from Elite athletes with > 90% accuracy. Compared to Elite athletes, Super-Elite athletes were characterized by: (1) An early critical negative life experience in close proximity to significant positive sport-related events; (2) higher relative importance of sport over other aspects of life, stronger obsessiveness/perfectionism, and sport-related ruthlessness/selfishness; (3) conjoint outcome and mastery focus, and use of counterphobic and/or âtotal preparationâ strategies to maintain/enhance performance under pressure; (4) coaches who better met their physical and psychosocial needs; (5) coming back after severe performance setbacks during adulthood, and career âturning pointsâ leading to enhanced determination to excel; (6) more pronounced diversified youth sport engagement, and prolonged extensive sport-specific practice and competitions; and (7) continued performance improvement over more years during adulthood, eventually attaining their (first) gold medal after 21 ± 6 practice years. The findings are discussed relative to potential causal interactions and theoretical implications
Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon
Carbon sequestration and storage in peatlands rely on consistently highwater tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but withmarked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age
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