7,722 research outputs found
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Neural plasticity in common forms of chronic headaches
Headaches are universal experiences and among the most common disorders. While headache may be physiological in the acute
setting, it can become a pathological and persistent condition.The mechanisms underlying the transition from episodic to chronic
pain have been the subject of intense study. Using physiological and imaging methods, researchers have identified a number of
different forms of neural plasticity associated with migraine and other headaches, including peripheral and central sensitization,
and alterations in the endogenous mechanisms of pain modulation. While these changes have been proposed to contribute to
headache and pain chronification, some findings are likely the results of repetitive noxious stimulation, such as atrophy of brain
areas involved in pain perception and modulation. In this review, we provide a narrative overview of recent advances on the
neuroimaging, electrophysiological and genetic aspects of neural plasticity associated with the most common forms of chronic
headaches, including migraine, cluster headache, tension-type headache, and medication overuse headache
Using a Hybrid Evolutionary Algorithm for Solving Signal Transmission Station Location and Allocation Problem with Different Regional Communication Quality Restriction
This study aims to investigate the signal transmission station location-allocation problems with the various restricted regional constraints. In each constraint, the types of signal transmission stations and the corresponding numbers and locations are to be decided at the same time. Inappropriate set up of stations is not only causing the unnecessary cost but also making the poor service quality. In this study, we proposed a hybrid evolutionary approach integrating the immune algorithm with particle swarm optimization (IAPSO) to solve this problem where each of the regions is with different maximum failure rate restrictions. We compared the performance of the proposed method with commercial optimization software LINGO®. According to the experimental results, solutions obtained by our IAPSO are better than or as well as the best solutions obtained by LINGO®. It is expected that our research can provide the telecommunication enterprise the optimal/near-optimal strategies for the setup of signal transmission stations
Merged Search Algorithms for Radio Frequency Identification Anticollision
Nowadays, the Radio Frequency Identification (RFID) system enables the control of many devices over an open communication infrastructure ranging from a small home area network to the global Internet. Moreover, a variety of consumer products are tagged with remotely low-cost readable identification electromagnetic tags to replace Bar Codes. Applications such as automatic object tracking, inventory and supply chain management, and Web appliances were adopted for years in many companies.
The arbitration algorithm for RFID system is used to arbitrate all the tags to avoid the collision problem with the existence of multiple tags in the interrogation field of a transponder. A splitting algorithm which is called Binary Search Tree (BST) is well known for multitags arbitration. In the current study, a splitting-based schema called Merged Search Tree is proposed to capture identification codes correctly for anticollision. Performance of the proposed algorithm is compared with the original BST according to time and power consumed during the arbitration process. The results show that the proposed model can reduce searching time and power consumed to achieve a better performance arbitration
Maternal Baicalin Treatment Increases Fetal Lung Surfactant Phospholipids in Rats
Baicalin is a flavonoid compound purified from the medicinal plant Scutellaria baicalensis Georgi and has been reported to stimulate surfactant protein (SP)-A gene expression in human lung epithelial cell lines (H441). The aims of this study were to determine whether maternal baicalin treatment could increase lung surfactant production and induce lung maturation in fetal rats. This study was performed with timed pregnant Sprague-Dawley rats. One-day baicalin group mothers were injected intraperitoneally with baicalin (5 mg/kg/day) on Day 18 of gestation. Two-day baicalin group mothers were injected intraperitoneally with baicalin (5 mg/kg/day) on Days 17 and 18 of gestation. Control group mothers were injected with vehicle alone on Day 18 of gestation. On Day 19 of gestation, fetuses were delivered by cesarean section. Maternal treatment with 2-day baicalin significantly increased saturated phospholipid when compared with control group and total phospholipid in fetal lung tissue when compared with control and 1-day baicalin groups. Antenatal treatment with 2-day baicalin significantly increased maternal growth hormone when compared with control group. Fetal lung SP-A mRNA expression and maternal serum corticosterone levels were comparable among the three experimental groups. Maternal baicalin treatment increases pulmonary surfactant phospholipids of fetal rat lungs and the improvement was associated with increased maternal serum growth hormone. These results suggest that antenatal baicalin treatment might accelerate fetal rat lung maturation
Glutamatergic Dysfunction and Glutamatergic Compounds for Major Psychiatric Disorders: Evidence From Clinical Neuroimaging Studies
Excessive glutamate release has been linked to stress and many neurodegenerative diseases. Evidence indicates abnormalities of glutamatergic neurotransmission or glutamatergic dysfunction as playing an important role in the development of many major psychiatric disorders (e.g., schizophrenia, bipolar disorder, and major depressive disorder). Recently, ketamine, an N-methyl-d-aspartate antagonist, has been demonstrated to have promisingly rapid antidepressant efficacy for treatment-resistant depression. Many compounds that target the glutamate system have also become available that possess potential in the treatment of major psychiatric disorders. In this review, we update evidence from recent human studies that directly or indirectly measured glutamatergic neurotransmission and function in major psychiatric disorders using modalities such as magnetic resonance spectroscopy, positron emission tomography/single-photon emission computed tomography, and paired-pulse transcranial magnetic stimulation. The newer generation of antidepressants that target the glutamatergic system developed in human clinical studies is also reviewed
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Regulation of axon repulsion by MAX-1 SUMOylation and AP-3.
During neural development, growing axons express specific surface receptors in response to various environmental guidance cues. These axon guidance receptors are regulated through intracellular trafficking and degradation to enable navigating axons to reach their targets. In Caenorhabditis elegans, the UNC-5 receptor is necessary for dorsal migration of developing motor axons. We previously found that MAX-1 is required for UNC-5-mediated axon repulsion, but its mechanism of action remained unclear. Here, we demonstrate that UNC-5-mediated axon repulsion in C. elegans motor axons requires both max-1 SUMOylation and the AP-3 complex β subunit gene, apb-3 Genetic interaction studies show that max-1 is SUMOylated by gei-17/PIAS1 and acts upstream of apb-3 Biochemical analysis suggests that constitutive interaction of MAX-1 and UNC-5 receptor is weakened by MAX-1 SUMOylation and by the presence of APB-3, a competitive interactor with UNC-5. Overexpression of APB-3 reroutes the trafficking of UNC-5 receptor into the lysosome for protein degradation. In vivo fluorescence recovery after photobleaching experiments shows that MAX-1 SUMOylation and APB-3 are required for proper trafficking of UNC-5 receptor in the axon. Our results demonstrate that SUMOylation of MAX-1 plays an important role in regulating AP-3-mediated trafficking and degradation of UNC-5 receptors during axon guidance
Counteracting Phishing Page Polymorphism: An Image Layout Analysis Approach
Abstract. Many visual similarity-based phishing page detectors have been developed to detect phishing webpages, however, scammers now cre-ate polymorphic phishing pages to breach the defense of those detectors. We call this kind of countermeasure phishing page polymorphism. Poly-morphic pages are visually similar to genuine pages they try to mimic, but they use different representation techniques. It increases the level of difficulty to detect phishing pages. In this paper, we propose an effective detection mechanism to detect polymorphic phishing pages. In contrast to existing approaches, we analyze the layout of webpages rather than the HTML codes, colors, or content. Specifically, we compute the sim-ilarity degree of a suspect page and an authentic page through image processing techniques. Then, the degrees of similarity are ranked by a classifier trained to detect phishing pages. To verify the efficacy of our phishing detection mechanism, we collected 6, 750 phishing pages and 312 mimicked targets for the performance evaluation. The results show that our method achieves an excellent detection rate of 99.6%.
Causal Evidence for the Role of Specific GABAergic Interneuron Types in Entorhinal Recruitment of Dentate Granule Cells
The dentate gyrus (DG) is the primary gate of the hippocampus and controls
information flow from the cortex to the hippocampus proper. To maintain normal
function, granule cells (GCs), the principal neurons in the DG, receive fine-
tuned inhibition from local-circuit GABAergic inhibitory interneurons (INs).
Abnormalities of GABAergic circuits in the DG are associated with several
brain disorders, including epilepsy, autism, schizophrenia, and Alzheimer
disease. Therefore, understanding the network mechanisms of inhibitory control
of GCs is of functional and pathophysiological importance. GABAergic
inhibitory INs are heterogeneous, but it is unclear how individual subtypes
contribute to GC activity. Using cell-type-specific optogenetic perturbation,
we investigated whether and how two major IN populations defined by
parvalbumin (PV) and somatostatin (SST) expression, regulate GC input
transformations. We showed that PV-expressing (PV+) INs, and not SST-
expressing (SST+) INs, primarily suppress GC responses to single cortical
stimulation. In addition, these two IN classes differentially regulate GC
responses to θ and γ frequency inputs from the cortex. Notably, PV+ INs
specifically control the onset of the spike series, whereas SST+ INs
preferentially regulate the later spikes in the series. Together, PV+ and SST+
GABAergic INs engage differentially in GC input-output transformations in
response to various activity patterns
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