8,373 research outputs found
Perceptually smooth timbral guides by state-space analysis of phase-vocoder parameters
Sculptor is a phase-vocoder-based package of programs
that allows users to explore timbral manipulation
of sound in real time. It is the product
of a research program seeking ultimately to perform
gestural capture by analysis of the sound a
performer makes using a conventional instrument.
Since the phase-vocoder output is of high dimensionality —
typically more than 1,000 channels per
analysis frame—mapping phase-vocoder output to
appropriate input parameters for a synthesizer is
only feasible in theory
Pneumococcal Serotype-Specific Antibodies Persist through Early Childhood after Infant Immunization: Follow-Up from a Randomized Controlled Trial
Background: In a previous UK multi-center randomized study 278 children received three doses of 7-valent (PCV-7) or 13-
valent (PCV-13) pneumococcal conjugate vaccine at 2, 4 and 12 months of age. At 13 months of age, most of these children had pneumococcal serotype-specific IgG concentrations 8.
Methods: Children who had participated in the original study were enrolled again at 3.5 years of age. Persistence of immunity following infant immunization with either PCV-7 or PCV-13 and the immune response to a PCV-13 booster at preschool age were investigated.
Results: In total, 108 children were followed-up to the age of 3.5 years and received a PCV-13 booster at this age. At least 76% of children who received PCV-7 or PCV-13 in infancy retained serotype-specific IgG concentrations 0.35 mg/ml against each of 4/6 of the additional PCV-13 serotypes; for serotypes 1 and 3 this proportion was 45% and 52%. In the PCV-7 group these percentages were significantly lower for serotypes 1, 5 and 7F. A pre-school PCV-13 booster was highly immunogenic and resulted in low rates of local and systemic adverse effects.
Conclusion: Despite some decline in antibody from 13 months of age, these data suggest that a majority of pre-school
children maintain protective serotype-specific antibody concentrations following conjugate vaccination at 2, 4 and 12 months of age.
Trial Registration: ClinicalTrials.gov NCT0109547
Rich Situated Attitudes
We outline a novel theory of natural language meaning, Rich
Situated Semantics [RSS], on which the content of sentential utterances
is semantically rich and informationally situated. In virtue of its situatedness,
an utterance’s rich situated content varies with the informational
situation of the cognitive agent interpreting the utterance. In virtue of its
richness, this content contains information beyond the utterance’s lexically
encoded information. The agent-dependence of rich situated content
solves a number of problems in semantics and the philosophy of language
(cf. [14, 20, 25]). In particular, since RSS varies the granularity of utterance
contents with the interpreting agent’s informational situation, it
solves the problem of finding suitably fine- or coarse-grained objects for
the content of propositional attitudes. In virtue of this variation, a layman
will reason with more propositions than an expert
Structural Polymorphism of the Cytoskeleton: A Model of Linker-Assisted Filament Aggregation
The phase behavior of charged rods in the presence of inter-rod linkers is
studied theoretically as a model for the equilibrium behavior underlying the
organization of actin filaments by linker proteins in the cytoskeleton. The
presence of linkers in the solution modifies the effective inter-rod
interaction and can lead to inter-filament attraction. Depending on the
system's composition and physical properties such as linker binding energies,
filaments will either orient perpendicular or parallel to each other, leading
to network-like or bundled structures. We show that such a system can have one
of three generic phase diagrams, one dominated by bundles, another by networks,
and the third containing both bundle and network-like phases. The first two
diagrams can be found over a wide range of interaction energies, while the
third occurs only for a narrow range. These results provide theoretical
understanding of the classification of linker proteins as bundling proteins or
crosslinking proteins. In addition, they suggest possible mechanisms by which
the cell may control cytoskeletal morphology.Comment: 17 pages, 3 figure
Contraction of cross-linked actomyosin bundles
Cross-linked actomyosin bundles retract when severed in vivo by laser
ablation, or when isolated from the cell and micromanipulated in vitro in the
presence of ATP. We identify the time scale for contraction as a viscoelastic
time tau, where the viscosity is due to (internal) protein friction. We obtain
an estimate of the order of magnitude of the contraction time tau ~ 10-100 s,
consistent with available experimental data for circumferential microfilament
bundles and stress fibers. Our results are supported by an exactly solvable,
hydrodynamic model of a retracting bundle as a cylinder of isotropic, active
matter, from which the order of magnitude of the active stress is estimated.Comment: To be published in Physical Biolog
Vivaldi 1991 - A study of the formation, circulation and ventilation of Eastern North Atlantic Central Water
31 páginas, 10 figuras, 1 tablaA synoptic, hydrographic data set comprising 32 full depth CTD casts and 2500
CTD/SeaSoar profiles to 500 m is used to describe the 0/S properties and circulation of Central
Water east of the mid-Atlantic Ridge and between 39°N and 54°N. Eastward transport of 20 x
10 ~ m 3 s l in the North Atlantic Current turns entirely northwards to the west of 54°N, 20°W.
This transport consists in the upper layers of Western North Atlantic Water freshened at
temperatures below 10°C by mixing with SubArctic Intermediate Water. Northern and
Southern branches of the North Atlantic Current are well defined and both turn northwards west
of 20°W. A further l0 x l0 s m 3 s "1 of Eastern North Atlantic Water forms and recirculates
anticyclonicaily to the west of Spain south of the North Atlantic Current and north of 40°N.
Eastern North Atlantic Water is most weakly stratified east of 20°W and there is clear
correlation between weakly stratified pycnostads and positive salinity anomalies relative to
Western North Atlantic Water. Thus Eastern North Atlantic Water is a winter Mode Water in
which strong winter cooling has increased the density and hence also the salinity anomaly at
a given temperature. Near the southern entrance to the Rockall Trough there is evidence that
salinities are also increased by Mediterranean Water influence. Circulation south of the North
Atlantic Current is complex. There is no evidence for direct ventilation southwards across 40°N
where water properties (0/S, potential vorticity and CFC-113) and historical data all indicate
westward ventilation east of 24°W, with weak southward ventilation occurring further west, in
the vicinity of the Azores. The circulation pattern suggested is remarkably similar to that
proposed by Helland-Hansen and Nansen in 1926 (The eastern North Atlantic, Geophysiske
Publicajoner, 4, 1-76), with anticyclonic circulation of colder Eastern North Atlantic Water
north of 40°N meeting warmer water from south of 40°N circulating cyclonically north of the
Azores Current. The distribution of pycnostads and 0IS properties between 20°W and 35°W
north of the Azores indicates alternate bands of Western and Eastern North Atlantic Water
moving eastward and westward respectively, including evidence for westward motion immediately
south of the Southern branch of the North Atlantic Current, possibly by westward propagation of
anticyclonic eddies containing deep pycnostadsPeer reviewe
An Exactly Conservative Integrator for the n-Body Problem
The two-dimensional n-body problem of classical mechanics is a non-integrable
Hamiltonian system for n > 2. Traditional numerical integration algorithms,
which are polynomials in the time step, typically lead to systematic drifts in
the computed value of the total energy and angular momentum. Even symplectic
integration schemes exactly conserve only an approximate Hamiltonian. We
present an algorithm that conserves the true Hamiltonian and the total angular
momentum to machine precision. It is derived by applying conventional
discretizations in a new space obtained by transformation of the dependent
variables. We develop the method first for the restricted circular three-body
problem, then for the general two-dimensional three-body problem, and finally
for the planar n-body problem. Jacobi coordinates are used to reduce the
two-dimensional n-body problem to an (n-1)-body problem that incorporates the
constant linear momentum and center of mass constraints. For a four-body
choreography, we find that a larger time step can be used with our conservative
algorithm than with symplectic and conventional integrators.Comment: 17 pages, 3 figures; to appear in J. Phys. A.: Math. Ge
Two-Dimensional Molecular Patterning by Surface-Enhanced Zn-Porphyrin Coordination
In this contribution, we show how zinc-5,10,15,20-meso-tetradodecylporphyrins (Zn-TDPs) self-assemble into stable organized arrays on the surface of graphite, thus positioning their metal center at regular distances from each other, creating a molecular pattern, while retaining the possibility to coordinate additional ligands. We also demonstrate that Zn-TDPs coordinated to 3-nitropyridine display a higher tendency to be adsorbed at the surface of highly oriented pyrolytic graphite (HOPG) than noncoordinated ones. In order to investigate the two-dimensional (2D) self-assembly of coordinated Zn-TDPs, solutions with different relative concentrations of 3-nitropyridine and Zn-TDP were prepared and deposited on the surface of HOPG. STM measurements at the liquid-solid interface reveal that the ratio of coordinated Zn-TDPs over noncoordinated Zn-TDPs is higher at the n-tetradecane/HOPG interface than in n-tetradecane solution. This enhanced binding of the axial ligand at the liquid/solid interface is likely related to the fact that physisorbed Zn-TDPs are better binding sites for nitropyridines.
Cognitive representations of disability behaviours in people with mobility limitations : consistency with theoretical constructs
Disability is conceptualised as behaviour by psychological theory and as a result of bodily impairment by medical models. However, how people with disabilities conceptualise those disabilities is unclear. The purpose of this study was to examine disability representations in people with mobility disabilities. Thirteen people with mobility disabilities completed personal repertory grids (using the method of triads) applied to activities used to measure disabilities. Ten judges with expertise in health psychology then examined the correspondence between the elicited disability constructs and psychological and medical models of disability. Participants with mobility disabilities generated 73 personal constructs ofdisability. These constructs were judged consistent with the content of two psychological models, namely the theory of planned behaviour and social cognitive theory and with the main medical model of disability, the International Classification of Functioning Disability and Health.Individuals with activity limitations conceptualise activities in a manner that is compatible with both psychological and medical models. This ensures adequate communication in contexts where the medical model is relevant, e.g. clinical contexts, as well as in everyday conversation about activities and behaviours. Finally, integrated models of disability may be of value for theory driven interdisciplinary approaches to disability and rehabilitation
A Tentative Modeling Study of the Effect of Wall Reactions on Oxidation Phenomena
This paper gives details of a tentative modeling study that investigates the
inhibiting effect of internal reactor walls treated with acid..
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