2,129 research outputs found
Increased expression of matrix metalloproteinase-9 in patients with temporal lobe epilepsy
Aim: The molecular mechanism of epileptogenesis in temporal lobe epilepsy is still unclear. Experimental studies have suggested that matrix metalloproteinases have important roles in this process, but human studies are limited. The aim of this study was to assess the expression of MMP-9, MMP-2 and their tissue inhibitors (TIMP-1 and TIMP-2) in patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Material and Methods: The tissue samples from temporal neocortex and hippocampus were obtained from patients with temporal lobe epilepsy with hippocampal sclerosis who had undergone anterior temporal lobectomy for recurrent medically resistant seizures. Immunohistochemical methods were used to determine the expression of MMP-9, MMP-2 and their tissue inhibitors. Tissue samples were also analyzed with transmission electron microscopy. Results: The immunoreactivity for MMP-9 both in hippocampal and temporal neocortical neurons was stronger than that of MMP-2. Additionally, there was a mild reaction for its tissue inhibitor TIMP-1 as with TIMP-2. The TEM analysis of the hippocampus revealed that there was apparent ultra-structural damage on the pericarya and neuropil of some neurons. There was obvious damage in the mitochondria and the nuclear membrane. Conclusion: The preliminary results of this study revealed that MMP-9 may have a role in patients with drug resistant TLE-HS
Scalable Tensor Factorizations for Incomplete Data
The problem of incomplete data - i.e., data with missing or unknown values -
in multi-way arrays is ubiquitous in biomedical signal processing, network
traffic analysis, bibliometrics, social network analysis, chemometrics,
computer vision, communication networks, etc. We consider the problem of how to
factorize data sets with missing values with the goal of capturing the
underlying latent structure of the data and possibly reconstructing missing
values (i.e., tensor completion). We focus on one of the most well-known tensor
factorizations that captures multi-linear structure, CANDECOMP/PARAFAC (CP). In
the presence of missing data, CP can be formulated as a weighted least squares
problem that models only the known entries. We develop an algorithm called
CP-WOPT (CP Weighted OPTimization) that uses a first-order optimization
approach to solve the weighted least squares problem. Based on extensive
numerical experiments, our algorithm is shown to successfully factorize tensors
with noise and up to 99% missing data. A unique aspect of our approach is that
it scales to sparse large-scale data, e.g., 1000 x 1000 x 1000 with five
million known entries (0.5% dense). We further demonstrate the usefulness of
CP-WOPT on two real-world applications: a novel EEG (electroencephalogram)
application where missing data is frequently encountered due to disconnections
of electrodes and the problem of modeling computer network traffic where data
may be absent due to the expense of the data collection process
B-> X_d \ell^+\ell^- in a CP softly broken two Higgs doublet model
We study the differential branching ratio, forward-backward asymmetry,
CP-violating asymmetry, CP-violating asymmetry in the forward-backward
asymmetry and polarization asymmetries of the final lepton in the B-> X_d
\ell^+\ell^- decays in the context of a CP softly broken two Higgs doublet
model. We analyze the dependencies of these observables on the model parameters
by paying a special attention to the effects of neutral Higgs boson (NHB)
exchanges and possible CP violating effects. We find that NHB effects are quite
significant for the \tau mode. The above-mentioned observables seems to be
promising as a testing ground for new physics beyond the SM, especially for the
existence of the CP-violating phase in the theory.Comment: 15 pages, 13 figure
Spinal cord stimulation in failed back surgery
Objective: Spinal cord stimulation is used for
treating failed back surgery syndrome, chronic
arachnoiditis, peripheral neuropathies, postamputation
phantom pain, complex regional pain syndrome and
pain secondary to spinal cord injury. In this study we
present 7 cases with intractable neuropathic radicular
pain which developed following spine surgery.
Material and Methods: Spinal cord stimulation
was applied to 7 (3male/4 female) patients who had
failed back surgery syndrome and pain resistant to
medical and invasive methods, with the council
decision, which included neurosurgery, neurology,
and psychiatry. One week stimulation trial was
applied to all cases.
Results:The mean age of the patients was
54.85±7.64 years. The mean of pain intensity in
Visual Analog Scale was 8.71±0.74 at preoperative
status and post operative pain intensity was 2.27±0.67
at 6 months. Pain intensity significantly decreases
after spinal cord stimulation (p=0.000). One of the
three cases who had unsuccessful trial period received
morphine pump implantation, and percutaneous
lumbar sympathectomy was applied to another one.
One case who received permanent implantation was
replaced to another location due to skin erosion. There
was no morbidity.
Conclusion: Spinal cord stimulation is an effective
tool in reducing pain, in patients who have
unsuccessful lower back surgery with the correct
indications
Mutual coupling of printed elements on a cylindrically layered structure using closed-form Green's functions
A hybrid method to calculate mutual coupling of electric or magnetic current elements on a cylindrically layered structure using closed-form Green's functions is presented. When rho = rho' and phi is not very close to phi', closed-form Green's functions are employed in the calculation of MoM matrix entries. When both rho = rho' and phi = phi', series representation of the spectral domain Green's functions do not converge, therefore closed-form Green's functions can not be employed. In that case MoM matrix entries are evaluated using the proposed hybrid method. The technique is applied to both printed dipoles and slots placed on a layered cylindrical structures. The computational efficiency of the analysis of mutual coupling of printed elements on cylindrically layered geometries is increased with the use of proposed hybrid method which employs closed-form Green's functions
Feedback Implosion Suppression Algorithm for Reliable Multicast Data Transmission over Geostationary Satellite Networks
Modelling human factors in perceptual multimedia quality: On the role of personality and culture
Perception of multimedia quality is shaped by a rich interplay between system, context, and human factors. While system and context factors are widely researched, few studies in this area consider human factors as sources of systematic variance. This paper presents an analysis on the influence of personality (Five-Factor Model) and cultural traits (Hofstede Model) on the perception of multimedia quality. A set of 144 video sequences (from 12 short movie excerpts) were rated by 114 participants from a cross-cultural population, producing 1232 ratings. On this data, three models are compared: a baseline model that only considers system factors; an extended model that includes personality and culture as human factors; and an optimistic model in which each participant is modeled as a random effect. An analysis shows that personality and cultural traits represent 9.3% of the variance attributable to human factors while human factors overall predict an equal or higher proportion of variance compared to system factors. In addition, the quality-enjoyment correlation varied across the movie excerpts. This suggests that human factors play an important role in perceptual multimedia quality, but further research to explore moderation effects and a broader range of human factors is warranted
Instability tests for air-jet textured yarns
The air-jet texturing process is briefly introduced and its advantages over other texturing processes are summarized. Characteristics of air-jet textured yarns are stated with special reference to the stability of the yarns. Test methods used in industry and research to determine the "stability" or "instability" of air-jet textured yarns are critically reviewed. These methods involve different basic principles and therefore inevitably give different results. There is no consensus on a standard method. Effects of various test parameters, such as specimen length, test duration, and the alternatives of using a single yarn, a hank, or a skein as a test specimen are investigated. An improved test method is suggested as a standard instability test, and various existing methods are compared with it. Results of all the methods show similar trends for varying values of air pressure. Other yarn characteristics such as linear density, breaking elongation, and tenacity are also determined, and their indications of yarn quality are compared with the indications of instability tests. Stability test results alone provide misleading information regarding air-jet textured yarn quality
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