395 research outputs found
Construction of wedge-local nets of observables through Longo-Witten endomorphisms. II
In the first part, we have constructed several families of interacting
wedge-local nets of von Neumann algebras. In particular, there has been
discovered a family of models based on the endomorphisms of the U(1)-current
algebra of Longo-Witten.
In this second part, we further investigate endomorphisms and interacting
models. The key ingredient is the free massless fermionic net, which contains
the U(1)-current net as the fixed point subnet with respect to the U(1) gauge
action. Through the restriction to the subnet, we construct a new family of
Longo-Witten endomorphisms on the U(1)-current net and accordingly interacting
wedge-local nets in two-dimensional spacetime. The U(1)-current net admits the
structure of particle numbers and the S-matrices of the models constructed here
do mix the spaces with different particle numbers of the bosonic Fock space.Comment: 33 pages, 1 tikz figure. The final version is available under Open
Access. CC-B
Ultrafast spectral-domain optical coherence tomography realized by parametric spectro-temporal analyzer
Performance of the spectral-domain optical coherence tomography is limited by its A-scan rate, namely the frame rate of spectrometer. In this paper, 60-MHz A-scan rate is achieved by adopting a recently demonstrated parametric spectro-temporal analyzer. © 2015 OSApostprin
On Multifractal Structure in Non-Representational Art
Multifractal analysis techniques are applied to patterns in several abstract
expressionist artworks, paintined by various artists. The analysis is carried
out on two distinct types of structures: the physical patterns formed by a
specific color (``blobs''), as well as patterns formed by the luminance
gradient between adjacent colors (``edges''). It is found that the analysis
method applied to ``blobs'' cannot distinguish between artists of the same
movement, yielding a multifractal spectrum of dimensions between about 1.5-1.8.
The method can distinguish between different types of images, however, as
demonstrated by studying a radically different type of art. The data suggests
that the ``edge'' method can distinguish between artists in the same movement,
and is proposed to represent a toy model of visual discrimination. A ``fractal
reconstruction'' analysis technique is also applied to the images, in order to
determine whether or not a specific signature can be extracted which might
serve as a type of fingerprint for the movement. However, these results are
vague and no direct conclusions may be drawn.Comment: 53 pp LaTeX, 10 figures (ps/eps
All-passive pixel super-resolution of time-stretch imaging
Based on image encoding in a serial-temporal format, optical time-stretch
imaging entails a stringent requirement of state-of-the- art fast data
acquisition unit in order to preserve high image resolution at an ultrahigh
frame rate --- hampering the widespread utilities of such technology. Here, we
propose a pixel super-resolution (pixel-SR) technique tailored for time-stretch
imaging that preserves pixel resolution at a relaxed sampling rate. It
harnesses the subpixel shifts between image frames inherently introduced by
asynchronous digital sampling of the continuous time-stretch imaging process.
Precise pixel registration is thus accomplished without any active
opto-mechanical subpixel-shift control or other additional hardware. Here, we
present the experimental pixel-SR image reconstruction pipeline that restores
high-resolution time-stretch images of microparticles and biological cells
(phytoplankton) at a relaxed sampling rate (approx. 2--5 GSa/s) --- more than
four times lower than the originally required readout rate (20 GSa/s) --- is
thus effective for high-throughput label-free, morphology-based cellular
classification down to single-cell precision. Upon integration with the
high-throughput image processing technology, this pixel-SR time- stretch
imaging technique represents a cost-effective and practical solution for large
scale cell-based phenotypic screening in biomedical diagnosis and machine
vision for quality control in manufacturing.Comment: 17 pages, 8 figure
Optical time-stretch microscopy enabled by free-space angular-chirp-enhanced delay
published_or_final_versio
What drives sound symbolism? Different acoustic cues underlie sound-size and sound-shape mappings
Sound symbolism refers to the non-arbitrary mappings that exist between phonetic properties of speech sounds and their meaning. Despite there being an extensive literature on the topic, the acoustic features and psychological mechanisms that give rise to sound symbolism are not, as yet, altogether clear. The present study was designed to investigate whether different sets of acoustic cues predict size and shape symbolism, respectively. In two experiments, participants judged whether a given consonant-vowel speech sound was large or small, round or angular, using a size or shape scale. Visual size judgments were predicted by vowel formant F1 in combination with F2, and by vowel duration. Visual shape judgments were, however, predicted by formants F2 and F3. Size and shape symbolism were thus not induced by a common mechanism, but rather were distinctly affected by acoustic properties of speech sounds. These findings portray sound symbolism as a process that is not based merely on broad categorical contrasts, such as round/unround and front/back vowels. Rather, individuals seem to base their sound-symbolic judgments on specific sets of acoustic cues, extracted from speech sounds, which vary across judgment dimensions
Growing pains in children
We review the clinical manifestations of "growing pains", the most common form of episodic childhood musculoskeletal pain. Physicians should be careful to adhere to clear clinical criteria as described in this review before diagnosing a child with growing pain. We expand on current theories on possible causes of growing pains and describe the management of these pains and the generally good outcome in nearly all children
HLA alleles associated with asparaginase hypersensitivity in Chinese children
Asparaginase is an important drug to treat childhood haematological malignancies. Data on the association between human leukocyte antigens (HLA) and asparaginase hypersensitivity among Chinese are lacking. We conducted a retrospective study to identify HLA alleles associated with asparaginase hypersensitivity among Chinese children with acute lymphoblastic leukaemia (ALL), mixed phenotype leukaemia and non-Hodgkin lymphoma (NHL), who received asparaginases with HLA typing performed between 2009 and 2019. 107 Chinese patients were analysed. 66.3% (71/107) developed hypersensitivity to at least one of the asparaginases. HLA-B*46:01 (OR 3.8, 95% CI 1.4-10.1, p < 0.01) and DRB1*09:01 (OR 4.3, 95% CI 1.6-11.4, p < 0.01) were significantly associated with L-asparaginase hypersensitivities, which remained significant after adjustment for age, gender and B cell ALL [HLA-B*46:01 (adjusted OR 3.5, 95% 1.3-10.5, p = 0.02) and DRB1*09:01 (OR 4.4, 95% CI 1.6-13.3, p < 0.01)]
Ischemia reperfusion dysfunction changes model-estimated kinetics of myofilament interaction due to inotropic drugs in isolated hearts
BACKGROUND: The phase-space relationship between simultaneously measured myoplasmic [Ca(2+)] and isovolumetric left ventricular pressure (LVP) in guinea pig intact hearts is altered by ischemic and inotropic interventions. Our objective was to mathematically model this phase-space relationship between [Ca(2+)] and LVP with a focus on the changes in cross-bridge kinetics and myofilament Ca(2+ )sensitivity responsible for alterations in Ca(2+)-contraction coupling due to inotropic drugs in the presence and absence of ischemia reperfusion (IR) injury. METHODS: We used a four state computational model to predict LVP using experimentally measured, averaged myoplasmic [Ca(2+)] transients from unpaced, isolated guinea pig hearts as the model input. Values of model parameters were estimated by minimizing the error between experimentally measured LVP and model-predicted LVP. RESULTS: We found that IR injury resulted in reduced myofilament Ca(2+ )sensitivity, and decreased cross-bridge association and dissociation rates. Dopamine (8 μM) reduced myofilament Ca(2+ )sensitivity before, but enhanced it after ischemia while improving cross-bridge kinetics before and after IR injury. Dobutamine (4 μM) reduced myofilament Ca(2+ )sensitivity while improving cross-bridge kinetics before and after ischemia. Digoxin (1 μM) increased myofilament Ca(2+ )sensitivity and cross-bridge kinetics after but not before ischemia. Levosimendan (1 μM) enhanced myofilament Ca(2+ )affinity and cross-bridge kinetics only after ischemia. CONCLUSION: Estimated model parameters reveal mechanistic changes in Ca(2+)-contraction coupling due to IR injury, specifically the inefficient utilization of Ca(2+ )for contractile function with diastolic contracture (increase in resting diastolic LVP). The model parameters also reveal drug-induced improvements in Ca(2+)-contraction coupling before and after IR injury
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