4,639 research outputs found
The Fictive Reflex : A Fresh Look at Reflexiveness and Narrative Representation
Reflexiveness in literary contexts tends to be assimilated to self-reference; to the various ways in which a work may foreground the artifice and conventionality of its own features as representation, narrative or language. In this sense it is equated with metafiction, and regarded as a sophisticated and highly self-conscious use of narrative; here, however, I offer a contrary view of reflexiveness, one which sees it as elementary, pervasive, and constitutive of fictionality. In this view, there is a continuity between the basic logic of mimesis and the self-conscious “baring of the device” that, for the Russian Formalists, defines the literary. I begin by clarifying the nature of (fictive) representation as an act, and identify its intrinsic reflexiveness, and go on to compare this perspective with both the metafictional notion of reflexiveness and the theoretical discourse on reflexiveness around “mirror neurons” in cognitive literary studies. I then situate reflexiveness within a broader interdisciplinary environment, framed by complex systems science and the conceptualization of emergence in terms of representational recursiveness, which allows the two sides of the discussion so far to be understood as complementary aspects of reflexiveness, one of which aligns with the cultivation of (self-) consciousness, the other with the simple enactment of systemic relations. Finally I address the conceptual challenge presented by an account of narrative, and fiction, based upon reflexiveness, and suggest some ways in which it can be understood
Health service use among adults with cerebral palsy: a mixed‐methods systematic review
Aim
To determine the proportion of adults with cerebral palsy (CP) using health services and frequency of use, and to explore experiences and perceptions of health services for this population.
Method
A mixed-methods systematic review was conducted using the Joanna Briggs Institute methodology. Five databases were searched to September 2020. Observational and qualitative studies were included. Two reviewers screened titles, abstracts, and full texts; extracted data; and assessed the quality of included studies. Separate meta-analyses were used to pool the proportion of adults using each service and frequency of use. A meta-aggregation approach was used to synthesize qualitative data. Quantitative and qualitative findings were integrated using the Andersen and Newman Model of health care utilization.
Results
Fifty-seven studies (31 quantitative, 26 qualitative) of 14 300 adults with CP were included. The proportion of adults using services ranged from 7% (95% confidence interval [CI]: 2–13%) for urologists to 84% (95% CI: 78–90%) for general practitioners. Incidence of visits ranged from 67 (95% CI: 37–123) hospital admissions to 404 (95% CI: 175–934) general practitioner visits per 100 person-years. Qualitative themes highlighted issues regarding accessibility, caregivers’ involvement, health workers’ expertise, unmet ageing needs, transition, and health system challenges.
Interpretation
Adults with CP used a wide range of health services but faced context-specific challenges in accessing required care. Appropriate service delivery models for adults with CP are required. This review emphasizes a need to develop an appropriate service model for adults with CP to meet their needs.SPHeRE Programme under Grant No.SPHeRE/2018/1; Royal College ofSurgeons in Ireland StAR programme
Feeding Concentrate Formulated With Native Irish Feed Ingredients and a Low Crude Protein Content to Grazing Dairy Cows Has No Effect on Milk Production or Milk Composition
Improving nitrogen use efficiency (NUE) and feeding native feed ingredients offers potential to improve the environmental sustainability of dairy production. However, improving NUE is a key challenge in grass-based systems due to high crude protein (CP) levels in grass and low nitrogen retention by dairy cows. In addition, concentrate feed typically contains imported feed ingredients which contribute to increased carbon footprint. Therefore, the objective of this study was to investigate the effect of concentrate CP level and ingredient source on milk production and composition. Forty-two mixed-parity Holstein-Friesian cows were blocked on parity and balanced on days in milk (DIM), milk production, BCS and Economic Breeding Index (EBI; n=14). Cows grazed full time and were offered a basal diet of perennial ryegrass pasture (average 17 kg DM/cow/day) and fed one of three concentrate supplements at varying levels according to DIM during the main grazing season (153 days). The concentrate treatments (T) were: T1) 14% CP concentrate formulated with non-native ingredients, T2) 12% CP concentrate formulated with non-native ingredients or T3) 12% CP concentrate formulated with native ingredients. Reducing the CP level or formulating with native feed ingredients did not alter milk or milk solids yield (T1: 25.7 kg/day, 2.11 kg/day; T2: 25.3 kg/day, 2.06 kg/day; T3: 24.9 kg/day, 2.01 kg/day respectively). Similarly, no effect of treatment was observed for milk fat or protein percentage (T1: 4.40 %, 3.66 %; T2: 4.44 %, 3.64 %; T3: 4.37 %, 3.66 %, respectively). The results of this study highlight that the sustainability of grass-based dairy may be improved by using a low concentrate CP content (12%) in addition to offering concentrate feed based on native feed ingredients which can result in similar performance to that of dairy cows offered a 14% CP concentrate or a concentrate based on imported ingredients respectively
Image Flux Ratios of Gravitationally Lensed HS 0810+2554 with High Resolution Infrared Imaging
We report near simultaneous imaging using LMIRCam on the LBTI of the
quadruply imaged lensed quasar HS 0810+2554 at wavelengths of 2.16, 3.7 and
m with a Full Width Half Max (FWHM) spatial resolution of
, and
respectively, comparable to HST optical imaging. In
the rest frame of the quasar, the observed wavelengths
correspond to 0.86, 1.48, and m respectively. The two brightest
images in the quad, A and B, are clearly resolved from each other with a
separation of . The flux ratio of these two images (A/B)
trends from 1.79 to 1.23 from 2.16 to m. The trend in flux ratio is
consistent with the m flux originating from a small sized accretion
disk in the quasar that experiences only microlensing. The excess flux above
the contribution from the accretion disk at the two longer wavelengths
originates from a larger sized region that experiences no microlensing. A
simple model employing multiplicative factors for image B due to stellar
microlensing and sub-structure millilensing is presented. The
result is tightly constrained to the product . Given the
observational errors, the 60\% probability contour for this product stretches
from , to , , where the later is
consistent with microlensing only.Comment: accepted A
Detecting weak spectral lines in interferometric data through matched filtering
Funding: R.A.L. and J.H. gratefully acknowledge funding from National Science Foundation Graduate Research Fellowships (Grant No. DGE-1144152). R.A.L. also acknowledges funding from the NRAO Student Observing Support Program. K.I.Ö. acknowledges funding from the Alfred P. Sloan Foundation and the David and Lucile Packard Foundation. C.W. acknowledges financial support from the Netherlands Organisation for Scientific Research (NWO, grant 639.041.335) and start-up funds from the University of Leeds, UK.Modern radio interferometers enable observations of spectral lines with unprecedented spatial resolution and sensitivity. In spite of these technical advances, many lines of interest are still at best weakly detected and therefore necessitate detection and analysis techniques specialized for the low signal-to-noise ratio (S/N) regime. Matched filters can leverage knowledge of the source structure and kinematics to increase sensitivity of spectral line observations. Application of the filter in the native Fourier domain improves S/N while simultaneously avoiding the computational cost and ambiguities associated with imaging, making matched filtering a fast and robust method for weak spectral line detection. We demonstrate how an approximate matched filter can be constructed from a previously observed line or from a model of the source, and we show how this filter can be used to robustly infer a detection significance for weak spectral lines. When applied to ALMA Cycle 2 observations of CH3OH in the protoplanetary disk around TW Hya, the technique yields a ≈53% S/N boost over aperture-based spectral extraction methods, and we show that an even higher boost will be achieved for observations at higher spatial resolution. A Python-based open-source implementation of this technique is available under the MIT license at http://github.com/AstroChem/VISIBLE.Publisher PDFPeer reviewe
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
Effect of head size and rotation on taper corrosion in a hip simulator
Aims
This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads.
Methods
In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth.
Results
Overall, 36 mm heads had lower corrosion onset load (p = 0.009) and change in open circuit potential (OCP) during simulated gait with (p = 0.006) and without joint movement (p = 0.004). Discontinuing gait’s joint movement decreased corrosion currents (p = 0.042); however, wear testing showed no significant effect of joint movement on taper damage. In addition, 36 mm heads had greater corrosion area (p = 0.050), but no significant difference was found for maximum linear wear depth (p = 0.155).
Conclusion
Larger heads are more susceptible to taper corrosion; however, not due to frictional torque as hypothesized. An alternative hypothesis of taper flexural rigidity differential is proposed. Further studies are necessary to investigate the clinical significance and underlying mechanism of this finding
The cometary composition of a protoplanetary disk as revealed by complex cyanides
Observations of comets and asteroids show that the Solar Nebula that spawned
our planetary system was rich in water and organic molecules. Bombardment
brought these organics to the young Earth's surface, seeding its early
chemistry. Unlike asteroids, comets preserve a nearly pristine record of the
Solar Nebula composition. The presence of cyanides in comets, including 0.01%
of methyl cyanide (CH3CN) with respect to water, is of special interest because
of the importance of C-N bonds for abiotic amino acid synthesis. Comet-like
compositions of simple and complex volatiles are found in protostars, and can
be readily explained by a combination of gas-phase chemistry to form e.g. HCN
and an active ice-phase chemistry on grain surfaces that advances
complexity[3]. Simple volatiles, including water and HCN, have been detected
previously in Solar Nebula analogues - protoplanetary disks around young stars
- indicating that they survive disk formation or are reformed in situ. It has
been hitherto unclear whether the same holds for more complex organic molecules
outside of the Solar Nebula, since recent observations show a dramatic change
in the chemistry at the boundary between nascent envelopes and young disks due
to accretion shocks[8]. Here we report the detection of CH3CN (and HCN and
HC3N) in the protoplanetary disk around the young star MWC 480. We find
abundance ratios of these N-bearing organics in the gas-phase similar to
comets, which suggests an even higher relative abundance of complex cyanides in
the disk ice. This implies that complex organics accompany simpler volatiles in
protoplanetary disks, and that the rich organic chemistry of the Solar Nebula
was not unique.Comment: Definitive version of the manuscript is published in Nature, 520,
7546, 198, 2015. This is the author's versio
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