FUNCTIONAL MAGNETIC RESONANCE IMAGING STUDY OF THE BRAIN IN PATIENTS WITH AMYOTROPHIC LATERAL SCLEROSIS

Objective To study the activation changes of the brain in patients with amyotrophic lateral sclerosis （ALS） while executing sequential finger tapping movement using the method of blood oxygenation level dependent （BOLD） functional magnetic resonance imaging （tMRI）. Methods Fifteen patients with definite or probable ALS and fifteen age and gender matched normal controls were enrolled. MRI was performed on a 3.0 Tesla scanner with standard headcoiL The functional images were acquired using a gradient echo single shot echo planar imaging （EPI） sequence. All patients and normal subjects executed sequential finger tapping movement at the frequency of 1-2 Hz during a block-design motor task. Structural MRI was acquired using a three-dimensional fast spoiled gradient echo （3D-FSPGR） sequence. The tMRI data were analyzed by statistical parametric mapping （SPM）. Results Bilateral primary sensorimotor cortex （ PSM）, bilateral premotor area （ PA）, bilateral supplementary motor area （SMA）, bilateral parietal region （ PAR）, contralateral inferior lateral premotor area （ ILPA）, and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM, bilateral PA, bilateral SMA, and ipsilateral cerebellum were significantly larger in ALS patients than those in normal controls （ P 〈 0.05 ）. Extra activation areas including ipsilateral ILPA, bilateral posterior limb of internal capsule, and contralateral cerebellum were only detected in ALS patients. Conclusions Similar activation areas are activated in ALS patients and normal subjects while executing the same motor task. The increased activation areas in ALS patients may represent neural reorganization, while the extra activation areas in ALS patients may indicate functional compensation.

OPTIMAL CONVERGENCE RATES OF LANDAU EQUATION WITH EXTERNAL FORCING IN THE WHOLE SPACE

In this paper, we combine the method of constructing the compensating function introduced by Kawashima and the standard energy method for the study on the Landau equation with external forcing. Both the global existence of solutions near the time asymptotic states which are local Maxwellians and the optimal convergence rates are obtained. The method used here has its own advantage for this kind of studies because it does not involve the spectrum analysis of the corresponding linearized operator.

Axonal remodeling in the corticospinal tract after stroke： how does rehabilitative training modulate it？

Stroke causes long-term disability, and rehabilitative training is commonly used to improve the consecutive functional recovery. Following brain damage, surviving neurons undergo morphological alterations to reconstruct the remaining neural network. In the motor system, such neural network remodeling is observed as a motor map reorganization. Because of its significant correlation with functional recovery, motor map reorganization has been regarded as a key phenomenon for functional recovery after stroke. Although the mechanism underlying motor map reorganization remains unclear, increasing evidence has shown a critical role for axonal remodeling in the corticospinal tract. In this study, we review previous studies investigating axonal remodeling in the corticospinal tract after stroke and discuss which mechanisms may underlie the stimulatory effect of rehabilitative training. Axonal remodeling in the corticospinal tract can be classified into three types based on the location and the original targets of corticospinal neurons, and it seems that all the surviving corticospinal neurons in both ipsilesional and contralesional hemisphere can participate in axonal remodeling and motor map reorganization. Through axonal remodeling, corticospinal neurons alter their output selectivity from a single to multiple areas to compensate for the lost function. The remodeling of the corticospinal axon is influenced by the extent of tissue destruction and promoted by various therapeutic interventions, including rehabilitative training. Although the precise molecular mechanism underlying rehabilitation-promoted axonal remodeling remains elusive, previous data suggest that rehabilitative training promotes axonal remodeling by upregulating growth-promoting and downregulating growth-inhibiting signals.

Dehazing algorithm using adaptive dark channel fusion and sky compensation

Aiming at the inaccurate transmission estimation problem of dark channel prior image dehazing algorithm in the sudden change area of depth of field and sky area,a dehazing algorithm using adaptive dark channel fusion and sky compensation is proposed.Firstly,according to the characteristics of minimum filtering of large window scale and small window scale in the dark channel prior,the fused dark channel is obtained by weighted fusion of the approximate depth of field relationship,thus obtaining the primary transmission.Secondly,use the down-sampling to optimize the primary transmission combined with gray scale image of haze image by fast joint bilateral filtering,then restore the original image size by up-sampling,and the compensation of the Gaussian function is used in the sky area to obtain corrected transmission.Finally,the improved atmospheric light is combined with atmospheric scattering model to recover haze-free image.Experimental results show that the algorithm can recover a large amount of detailed information of the image,obtain high visibility,and effectively eliminate the halo effect.At the same time,it has a better recovery effect on bright areas such as the sky area.

THE VLASOV-MAXWELL-FOKKER-PLANCK SYSTEM WITH RELATIVISTIC TRANSPORT IN THE WHOLE SPACE

In this paper, we consider the Vlasov-Maxwell-Fokker-Planck system with relativistic transport in the whole space. The global solutions to this system near the relativistic Maxwellian are constructed and the optimal time decay rate of global solutions are also obtained by an approach by combining the compensating function and energy method.

A New Approximation to the Jacobian Logarithm Suitable for MAP Decoding in BICM-ID

In this paper, a new method to approximate the compensation term in the Jacobian logarithm used by the MAP decoder is proposed. Using the proposed approximation, the complex functions In（.） and exp（.） in the Exact-log-MAP algorithm can be estimated with high accuracy and lower computational complexity. The efficacy of the proposed approximation is investigated and demonstrated by applying it to iteratively decoded BICM （Bit Interleaved Coded Modulation）.

Effects of Nectar Property on Compensated Dipping Behavior of Honey Bees with Damaged Tongues

In nature,bees with damaged tongues are adapted to have a feat in collecting nectariferous sources in a large spectrum of concentrations(19%-69%)or viscosities(10^(-3)Pa·s to 10^(-1)Pa·s);however,eff ects of nectar property on compensated dipping behavior remain elusive.Combining the bee tongue anatomy,high-speed videography,and mathematical models,we investigate responses of honey bees with damaged tongues to fluidic sources in various properties.We find that,bees with 80%damaged tongues are deprived of feeding capability and remarkably,the dipping frequency increases from 4.24 Hz to 5.08 Hz while ingesting 25%sugar water when the tongue loses 0-30%in length,while declines from 5.08 to 3.86 Hz in case of 30%damaged tongue when sucrose concentration increases from 25%to 45%.We employ the energetic compensation rate and energetic utilization rate to evaluate eff ectiveness of the compensation from the perspective of energetic regulation.The mathematical model indicates that the energetic compensation rate turns higher in bees with less damaged tongues for ingesting dilute sugar water,demonstrating its capability of functional compensation for combined factors.Also,the tongue-damaged bees achieve the highest energetic utilization rate when ingesting~30%sugar water.Beyond biology,the findings may shed lights on biomimetic materials and technologies that aim to compensate for geometrical degradations without regeneration.