Abstract Objective To test the reliability and validity of shoulder joint angle measurements from the Microsoft Kinect™ for virtual rehabilitation. Design Test–retest reliability and concurrent ...validity, feasibility study. Setting Motion analysis laboratory. Participants A convenience sample of 10 healthy adults. Methods Shoulder joint angle was assessed in four static poses, two trials for each pose, using: (1) the Kinect; (2) a three-dimensional motion analysis system; and (3) a clinical goniometer. All poses were captured with the Kinect from the frontal view. The two poses of shoulder flexion were also captured with the Kinect from the sagittal view. Main outcome measures Absolute and relative test–retest reliability of the Kinect for the measurement of shoulder angle was determined in each pose with intraclass correlation coefficients (ICCs), standard error of the measure and minimal detectable change. The 95% limits of agreement (LOA) between the Kinect and the standard methods for measuring shoulder angle were computed to determine concurrent validity. Results While the Kinect provided to be highly reliable (ICC 0.76–0.98) for measuring shoulder angle from the frontal view, the 95% LOA between the Kinect and the two measurement standards were greater than ±5° in all poses for both views. Conclusions Before the Kinect is used to measure movements for virtual rehabilitation applications, it is imperative to understand its limitations in precision and accuracy for the measurement of specific joint motions.
Because of the broken time-translation symmetry, in periodically driven vibrational systems fluctuations of different vibration components have different intensities. Fluctuations of one of the ...components are often squeezed, whereas fluctuations of the other component, which is shifted in phase byπ/2, are increased. Squeezing is a multifaceted phenomenon; it attracts much attention from the perspective of high-precision measurements. Here we demonstrate a new and hitherto unappreciated side of squeezing: its direct manifestation in the spectra of driven vibrational systems. With a weakly damped nanomechanical resonator, we study the spectrum of thermal fluctuations of a resonantly driven nonlinear mode. In the attained sideband-resolved regime, we show that the asymmetry of the spectrum directly characterizes the squeezing. This opens a way to deduce squeezing of thermal fluctuations in strongly underdamped resonators, for which a direct determination by a standard homodyne measurement is impeded by frequency fluctuations. The experimental and theoretical results are in excellent agreement. We further extend the theory to also describe the spectral manifestation of squeezing of quantum fluctuations.
Abstract
The Pan-STARRS1 (PS1) Science Consortium has carried out a set of imaging surveys using the 1.4 gigapixel GPC1 camera on the PS1 telescope. As this camera is composed of many individual ...electronic readouts and covers a very large field of view, great care was taken to ensure that the many instrumental effects were corrected to produce the most uniform detector response possible. We present the image-detrending steps used as part of the processing of the data contained within the public release of Pan-STARRS1 Data Release 1 (DR1). In addition to the single image processing, the methods used to transform the 375,573 individual exposures into a common sky-oriented grid are discussed, as well as those used to produce both the image stack and difference combination products.
The capacity of the adult brain and spinal cord to repair lesions by axonal
regeneration or compensatory fibre growth is extremely limited. A monoclonal
antibody (IN-1) raised against NI-220/250, a ...myelin protein that is a potent
inhibitor of neurite growth, promoted axonal regeneration and compensatory
plasticity following lesions of the central nervous system (CNS) in adult
rats. Here we report the cloning of nogo A,
the rat complementary DNA encoding NI-220/250. The nogo gene encodes
at least three major protein products (Nogo-A, -B and -C). Recombinant Nogo-A
is recognized by monoclonal antibody IN-1, and it inhibits neurite outgrowth
from dorsal root ganglia and spreading of 3T3 fibroblasts in an IN-1-sensitive
manner. Antibodies against Nogo-A stain CNS myelin and oligodendrocytes and
allow dorsal root ganglion neurites to grow on CNS myelin and into optic nerve
explants. These data show that Nogo-A is a potent inhibitor of neurite growth
and an IN-1 antigen produced by oligodendrocytes, and may allow the generation
of new reagents to enhance CNS regeneration and plasticity.
The Total Synthesis of (−)-Nitidasin Hog, Daniel T.; Huber, Florian M. E.; Mayer, Peter ...
Angewandte Chemie (International ed.),
August 4, 2014, Letnik:
53, Številka:
32
Journal Article
Recenzirano
Nitidasin is a pentacyclic sesterterpenoid with a rare 5‐8‐6‐5 carbon skeleton that was isolated from the Peruvian folk medicine “Hercampuri”. It belongs to a small class of sesterterpenoids that ...feature an isopropyl trans‐hydrindane moiety fused to a variety of other ring systems. As a first installment of our general approach toward these natural products, we report the total synthesis of the title compound. Our stereoselective, convergent route involves the addition of a complex alkenyl lithium compound to a trans‐hydrindanone, followed by chemoselective epoxidation, ring‐closing olefin metathesis, and redox adjustment.
Put a ring on it: The first total synthesis of nitidasin, a complex sesterterpenoid with a 5‐8‐6‐5 skeleton, is reported. It involves the addition of a tetrasubstituted alkenyl lithium compound to a trans‐hydrindanone and an olefin metathesis to form a highly substituted eight‐membered ring at an unexpected site. The absolute configuration of nitidasin was established with our highly stereoselective and convergent synthesis.
Capturing exotic magnetism
Ferromagnetism is associated with the breaking of time-reversal symmetry, most frequently by the spin degree of freedom. Although the orbital motion of electrons can also ...contribute to ferromagnetism, in most materials, it is small relative to the spin contribution. Tschirhart
et al.
showed that the reverse is true in an unusual magnetic state hosted by twisted bilayer graphene. Their scanning magnetometry measurements were consistent with ferromagnetism of predominantly orbital origin.
Science
, abd3190, this issue p.
1323
Scanning magnetometry measurements show that a magnetic state in twisted bilayer graphene has orbital origin.
Electrons in moiré flat band systems can spontaneously break time-reversal symmetry, giving rise to a quantized anomalous Hall effect. In this study, we use a superconducting quantum interference device to image stray magnetic fields in twisted bilayer graphene aligned to hexagonal boron nitride. We find a magnetization of several Bohr magnetons per charge carrier, demonstrating that the magnetism is primarily orbital in nature. Our measurements reveal a large change in the magnetization as the chemical potential is swept across the quantum anomalous Hall gap, consistent with the expected contribution of chiral edge states to the magnetization of an orbital Chern insulator. Mapping the spatial evolution of field-driven magnetic reversal, we find a series of reproducible micrometer-scale domains pinned to structural disorder.
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