472 research outputs found
Can proprioceptive training improve motor learning?
Recent work has investigated the link between motor learning and sensory function in arm movement control. A number of findings are consistent with the idea that motor learning is associated with systematic changes to proprioception (Haith A, Jackson C, Mial R, Vijayakumar S. Adv Neural Inf Process Syst 21: 593-600, 2008; Ostry DJ, Darainy M, Mattar AA, Wong J, Gribble PL. J Neurosci 30: 5384-5393, 2010; Vahdat S, Darainy M, Milner TE, Ostry DJ. J Neurosci 31: 16907- 16915, 2011). Here, we tested whether motor learning could be improved by providing subjects with proprioceptive training on a desired hand trajectory. Subjects were instructed to reproduce both the time-varying position and velocity of novel, complex hand trajectories. Subjects underwent 3 days of training with 90 movement trials per day. Active movement trials were interleaved with demonstration trials. For control subjects, these interleaved demonstration trials consisted of visual demonstration alone. A second group of subjects received visual and proprioceptive demonstration simultaneously; this group was presented with the same visual stimulus, but, in addition, their limb was moved through the target trajectory by a robot using servo control. Subjects who experienced the additional proprioceptive demonstration of the desired trajectory showed greater improvements during training movements than control subjects who only received visual information. This benefit of adding proprioceptive training was seen in both movement speed and position error. Interestingly, additional control subjects who received proprioceptive guidance while actively moving their arm during demonstration trials did not show the same improvement in positional accuracy. These findings support the idea that the addition of proprioceptive training can augment motor learning, and that this benefit is greatest when the subject passively experiences the goal movement. © 2012 the American Physiological Society
An Analysis of Human Silhouettes with Normalised Silhouettes Images and Shape Fourier Descriptors
This paper aims to investigate the human silhouettes in video frames, which involves normalizing the silhouettes and describing the shape of the region in video frames using Shape Fourier Descriptors. Shape Fourier Descriptor describes the shape of an object by considering its boundaries, which are the shape centroid and calculated by a particular formula through all the video frames after normalized the videos. This shows the changes of the objects with various actions and can be recognized and characterized human or non-human in the video frames. Normalized Silhouette Image is significant before the videos are being processed to describe in descriptors. It focuses on the region based on the object’s ratio in images of the shape of the object and silhouette images are centred after action segmentation. This reduces the burden of the process of extract unnecessary part in whole videos. Various human action videos and animal videos are used for the training and testing in this study to make sure the system performed better
Antisense suppression of donor splice site mutations in the dystrophin gene transcript
We describe two donor splice site mutations, affecting dystrophin exons 16 and 45 that led to Duchenne muscular dystrophy (DMD), through catastrophic inactivation of the mRNA. These gene lesions unexpectedly resulted in the retention of the downstream introns, thereby increasing the length of the dystrophin mRNA by 20.2 and 36 kb, respectively. Splice-switching antisense oligomers targeted to exon 16 excised this in-frame exon and the following intron from the patient dystrophin transcript very efficiently in vitro, thereby restoring the reading frame and allowing synthesis of near-normal levels of a putatively functional dystrophin isoform. In contrast, targeting splice-switching oligomers to exon 45 in patient cells promoted only modest levels of an out-of-frame dystrophin transcript after transfection at high oligomer concentrations, whereas dual targeting of exons 44 and 45 or 45 and 46 resulted in more efficient exon skipping, with concomitant removal of intron 45. The splice site mutations reported here appear highly amenable to antisense oligomer intervention. We suggest that other splice site mutations may need to be evaluated for oligomer interventions on a case-by-case basis
Field tests on a grease trap effluent filter
This study investigates the field performance tests of a commercial grease trap effluent filter for
removal of total suspended solids, and oil and grease discharged from the clear zone of full service restaurant grease
traps. The grease trap effluent filters were installed on 1,000-gallon, 2,000-gallon and 5,400-gallon full service
restaurant grease traps over a period of 8 weeks, and samples were taken at the inlets and outlets. On average, the
effluent filters demonstrated to be capable of removing 41% to 57% of TSS, and 43% to 52% of O and G. Field test
data also showed that the total amount of TSS removed by the grease trap effluent filter installed on 1,000 gallon, 2,000
gallon and 5,400 gallon grease traps were approximately 2,542 kg, 709 kg, and 2,319 kg, respectively; and the total
amount of O and G removed over the same period were approximately 1,104 kg, 271 kg, and 897 kg, respectivel
Optimization of Circular Plate Separators with Cross Flow for Removal of Oil Droplets and Solid Particles
A circular gravity-phase separator using coalescing
medium with cross flow was developed to remove oil and suspended
solids from wastewaters. Coalescence medium in the form of inclined
plates promotes rising of oil droplets through coalescence and settling of
solid particles through coagulation. It exhibits 22.67% higher removal of
total suspended solids (TSS) compared to separators without coalescing
medium. Moreover, it removed more than 70% of oil compared to
conventional American Petroleum Institute separators, which exhibit an
average of 33% oil removal. The flowrate required to attain an effluent oil
concentration of 10 mg/L (Qo10) at different influent oil concentrations
(Cio) can be represented by Qo10 3 1025 5 20.0012Cio + 0.352. The
flowrate required to attain an effluent TSS concentration of 50 mg/L
(Qss50) at different influent TSS concentrations (Ciss) can be represented
by Qss50 3 1025 5 1.0 3 106 Ciss
22.9576. The smallest removable solid
particle size was 4.87 mm. Water Environ. Res., 84, 299 (2012)
B_c Meson Production in Nuclear Collisions at RHIC
We study quantitatively the formation and evolution of B_c bound states in a
space-time domain of deconfined quarks and gluons (quark-gluon plasma, QGP). At
the Relativistic Heavy Ion Collider (RHIC) one expects for the first time that
typical central collisions will result in multiple pairs of heavy (in this case
charmed) quarks. This provides a new mechanism for the formation of heavy
quarkonia which depends on the properties of the deconfined region. We find
typical enhancements of about 500 fold for the B_c production yields over
expectations from the elementary coherent hadronic B_c-meson production
scenario. The final population of bound states may serve as a probe of the
plasma phase parameters.Comment: 9 Pages, 11 Postscript Figure
Pathogenic Role of microRNA in Rheumatoid Arthritis
Rheumatoid arthritis (RA) being a chronic inflammatory disease can be affected by both genetic and environmental factors. Abnormal functioning of immune response is the main underlying cause of RA. A growing number of studies on related diseases uncovered that microRNA (miRNA) may influence the pathogenesis of RA, such as the promotion of proliferation of fibroblast-like synoviocytes and secretion of cytokines by highly expressed miRNAs. A large number of studies have reported the aberrant expressions of miRNAs during the entire phase of RA, from the preclinical to terminal stages. These dynamic changes can be potentially developed as a bio-marker for predicting the risk, diagnosis and clinical management of RA. This chapter aims to summarize and discuss miRNAs’ roles and mechanisms in the process of RA development, differential diagnosis from other diseases, clinical management and refractory RA. Therefore, miRNA demonstrates future perspectives of diagnosis and treatment of clinical RA under the support of newly discovered theoretical basis
Persistence of a Continuous Stochastic Process with Discrete-Time Sampling: Non-Markov Processes
We consider the problem of `discrete-time persistence', which deals with the
zero-crossings of a continuous stochastic process, X(T), measured at discrete
times, T = n(\Delta T). For a Gaussian Stationary Process the persistence (no
crossing) probability decays as exp(-\theta_D T) = [\rho(a)]^n for large n,
where a = \exp[-(\Delta T)/2], and the discrete persistence exponent, \theta_D,
is given by \theta_D = \ln(\rho)/2\ln(a). Using the `Independent Interval
Approximation', we show how \theta_D varies with (\Delta T) for small (\Delta
T) and conclude that experimental measurements of persistence for smooth
processes, such as diffusion, are less sensitive to the effects of discrete
sampling than measurements of a randomly accelerated particle or random walker.
We extend the matrix method developed by us previously [Phys. Rev. E 64,
015151(R) (2001)] to determine \rho(a) for a two-dimensional random walk and
the one-dimensional random acceleration problem. We also consider `alternating
persistence', which corresponds to a < 0, and calculate \rho(a) for this case.Comment: 14 pages plus 8 figure
Atom gratings produced by large angle atom beam splitters
An asymptotic theory of atom scattering by large amplitude periodic
potentials is developed in the Raman-Nath approximation. The atom grating
profile arising after scattering is evaluated in the Fresnel zone for
triangular, sinusoidal, magneto-optical, and bichromatic field potentials. It
is shown that, owing to the scattering in these potentials, two
\QTR{em}{groups} of momentum states are produced rather than two distinct
momentum components. The corresponding spatial density profile is calculated
and found to differ significantly from a pure sinusoid.Comment: 16 pages, 7 figure
Fraction of uninfected walkers in the one-dimensional Potts model
The dynamics of the one-dimensional q-state Potts model, in the zero
temperature limit, can be formulated through the motion of random walkers which
either annihilate (A + A -> 0) or coalesce (A + A -> A) with a q-dependent
probability. We consider all of the walkers in this model to be mutually
infectious. Whenever two walkers meet, they experience mutual contamination.
Walkers which avoid an encounter with another random walker up to time t remain
uninfected. The fraction of uninfected walkers is investigated numerically and
found to decay algebraically, U(t) \sim t^{-\phi(q)}, with a nontrivial
exponent \phi(q). Our study is extended to include the coupled
diffusion-limited reaction A+A -> B, B+B -> A in one dimension with equal
initial densities of A and B particles. We find that the density of walkers
decays in this model as \rho(t) \sim t^{-1/2}. The fraction of sites unvisited
by either an A or a B particle is found to obey a power law, P(t) \sim
t^{-\theta} with \theta \simeq 1.33. We discuss these exponents within the
context of the q-state Potts model and present numerical evidence that the
fraction of walkers which remain uninfected decays as U(t) \sim t^{-\phi},
where \phi \simeq 1.13 when infection occurs between like particles only, and
\phi \simeq 1.93 when we also include cross-species contamination.Comment: Expanded introduction with more discussion of related wor
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