37,600 research outputs found
On The Linguistic Effects Of Articulatory Ease, With A Focus On Sign Languages
Spoken language has a well-known drive for ease of articulation, which Kirchner (1998, 2004) analyzes as reduction of the total magnitude of all biomechanical forces involved. We extend Kirchner\u27s insights from vocal articulation to manual articulation, with a focus on joint usage, and we discuss ways that articulatory ease might be realized in sign languages. In particular, moving more joints and/or joints more proximal to the torso results in greater mass being moved, and thus more articulatory force being expended, than moving fewer joints or moving more distal joints. We predict that in casual conversation, where articulatory ease is prized, moving fewer joints should be favored over moving more, and moving distal joints should be favored over moving proximal joints. We report on the results of our study of the casual signing of fluent signers of American Sign Language, which confirm our predictions: in comparison to citation forms of signs, the casual variants produced by the signers in our experiment exhibit an overall decrease in average joint usage, as well as a general preference for more distal articulation than is used in citation form. We conclude that all language, regardless of modality, is shaped by a fundamental drive for ease of articulation. Our work advances a cross-modality approach for considering ease of articulation, develops a potentially important vocabulary for describing variations in signs, and demonstrates that American Sign Language exhibits variation that can be accounted for in terms of ease of articulation. We further suggest that the linguistic drive for ease of articulation is part of a broader tendency for the human body to reduce biomechanical effort in all physical activities
Required Rates of Return for Corporate Investment Appraisal in the Presence of Growth Opportunities
Traditional methods of estimating required rates of return overstate hurdle rates in the presence of growth opportunities. We attempt to quantify this effect by developing a simple model which: (i) identifies those companies that have valuable growth opportunities; (ii) splits the value of shares into 'assets-in-place' and 'growth opportunities'; and (iii) splits the equity β into β for 'assets-in-place' and 'growth opportunities'. We find growth opportunities for UK companies over the 1990–2004 period to average 33% of equity value. Incorporating the effect of growth opportunities, the average cost of capital for investment purposes falls by 1.1 percentage points
Measuring the Hidden Aspects of Solar Magnetism
2008 marks the 100th anniversary of the discovery of astrophysical magnetic
fields, when George Ellery Hale recorded the Zeeman splitting of spectral lines
in sunspots. With the introduction of Babcock's photoelectric magnetograph it
soon became clear that the Sun's magnetic field outside sunspots is extremely
structured. The field strengths that were measured were found to get larger
when the spatial resolution was improved. It was therefore necessary to come up
with methods to go beyond the spatial resolution limit and diagnose the
intrinsic magnetic-field properties without dependence on the quality of the
telescope used. The line-ratio technique that was developed in the early 1970s
revealed a picture where most flux that we see in magnetograms originates in
highly bundled, kG fields with a tiny volume filling factor. This led to
interpretations in terms of discrete, strong-field magnetic flux tubes embedded
in a rather field-free medium, and a whole industry of flux tube models at
increasing levels of sophistication. This magnetic-field paradigm has now been
shattered with the advent of high-precision imaging polarimeters that allow us
to apply the so-called "Second Solar Spectrum" to diagnose aspects of solar
magnetism that have been hidden to Zeeman diagnostics. It is found that the
bulk of the photospheric volume is seething with intermediately strong, tangled
fields. In the new paradigm the field behaves like a fractal with a high degree
of self-similarity, spanning about 8 orders of magnitude in scale size, down to
scales of order 10 m.Comment: To appear in "Magnetic Coupling between the Interior and the
Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and
Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200
Connection between a possible fifth force and the direct detection of Dark Matter
If there is a fifth force in the dark sector and dark sector particles
interact non-gravitationally with ordinary matter, quantum corrections
generically lead to a fifth force in the visible sector. We show how the strong
experimental limits on fifth forces in the visible sector constrain the direct
detection cross section, and the strength of the fifth force in the dark
sector. If the latter is comparable to gravity, the spin-independent direct
detection cross section must typically be <~ 10^{-55} cm^2. The anomalous
acceleration of ordinary matter falling towards dark matter is also
constrained: \eta_{OM-DM} <~ 10^{-8}.Comment: 4 pages, 2 figures. v3: contains a more detailed treatment of the
spin-dependence of the effective interaction between dark matter and ordinary
matte
Overview of holistic application of biogas for small scale farmers in Sub-Saharan Africa
Peer reviewedPostprin
Fighting Ebola in Sierra Leone: the experience of frontline NHS workers
A group of UK trainees find themselves face-to-face with one of the most catastrophic health crises in recent times
Numerical simulations of flow and mass transport processes in the anterior chamber in the presence of an iris-fixated intraocular lens
The effect of spatially correlated noise on coherence resonance in a network of excitable cells
We study the effect of spatially correlated noise on coherence resonance (CR)
in a Watts-Strogatz small-world network of Fitz Hugh-Nagumo neurons, where the
noise correlation decays exponentially with distance between neurons. It is
found that CR is considerably improved just by a small fraction of long-range
connections for an intermediate coupling strength. For other coupling
strengths, an abrupt change in CR occurs following the drastic fracture of the
clustered structures in the network. Our study shows that spatially correlated
noise plays a significant role in the phenomenon of CR through enforcing the
clustering of the network.Comment: 11 pages, 4 figur
High fidelity sorting of remarkably similar components via metal-mediated assembly.
Subtle differences in ligand coordination angle and rigidity lead to high fidelity sorting between individual components displaying identical coordination motifs upon metal-mediated self-assembly. Narcissistic self-sorting can be achieved between highly similar ligands that vary minimally in rigidity and internal coordination angle upon combination with Fe(ii) ions and 2-formylpyridine. Selective, sequential cage formation can be precisely controlled in a single flask from a mix of three different core ligands (and 33 total components) differing only in the hybridization of one group that is uninvolved in the metal coordination process
The physiological expression of inducible nitric oxide synthase (iNOS) in the human colon
Inducible nitric oxide synthase (iNOS) is expressed in the colonic epithelium in both inflammatory bowel disease and colorectal cancer. Nitric oxide (NO), the product of this enzyme, has been implicated in the pathogenesis of both conditions. However, there are conflicting data on whether iNOS is expressed in the normal, uninflamed human colon. To evaluate the expression of iNOS in histologically normal, non-inflamed human colonic mucosa. Reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemistry were used to investigate the expression of iNOS in 17 histologically normal specimens obtained at colectomy performed for colorectal neoplasia. In addition, 16 endoscopic mucosal biopsies, taken from normal individuals, were also evaluated. Eleven surgical specimens and 16 endoscopic biopsies from patients with refractory ulcerative colitis were used as inflammatory controls. All types of specimens expressed iNOS mRNA. Immunoblotting revealed a protein of approximately 130 kDa consistent with iNOS in mucosal extracts of 77% of normal individuals, and 85% of diseased controls. Immunolabelling localised this protein to the surface epithelium in most of the normal specimens and also to the crypt epithelium and inflammatory cells in the diseased controls. These findings provide evidence that iNOS is often expressed in the surface epithelium of non-inflamed human colon, suggesting that it is induced by local luminal factors, such as bacterial lipopolysaccharide (endotoxin). The resultant NO produced at this site might act as an oxidative barrier, reducing bacterial translocation and providing a means of defence against pathogenic microorganisms
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