31,770 research outputs found
Overexpression of Heme Oxygenase-1 Protects Dopaminergic Neurons against 1-Methyl-4-Phenylpyridinium-Induced Neurotoxicity
No full textHeme oxygenase-1 (HO-1) is up-regulated in response to oxidative stress and catalyzes the degradation of pro- oxidant heme to carbon monoxide (CO) , iron, and bilirubin. Intense HO-1 immunostaining in the Parkinsonian brain is demonstrated, indicating that HO-1 may be involved in the pathogenesis of Parkinsonism. We here locally injected adenovirus containing human HO-1 gene (Ad-HO-1) into rat substantia nigra concomitantly with 1-methyl-4- phenylpyridinium (MPP(+)). Seven days after injection of MPP (+) and Ad-HO-1, the brain was isolated for immunostaining and for measurement of dopamine content and inflammatory cytokines. It was found that overexpression of HO-1 significantly increased the survival rate of dopaminergic neurons; reduced the production of tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) in substantia nigra; antagonized the reduction of striatal dopamine content induced by MPP(+); and also up-regulated brain-derived neurotrophic factor (BDNF) and glial cell line -derived neurotrophic factor (GDNF) expression in substantia nigra. Apomorphine-induced rotation after MPP(+) treatment was also inhibited by Ad-HO-1. On the other hand, inhibition of HO enzymatic activity by zinc protoporphyrin-IX facilitated the MPP(+)-induced rotatory behavior and enhanced the reduction of dopamine content. HO-1 overexpression also protected dopaminergic neurons against MPP(+)-induced neurotoxicity in midbrain neuron-glia cocultures. Overexpression of HO-1 increased the expression of BDNF and GDNF in astrocytes and BDNF in neurons. Our results indicate that HO-1 induction exerts neuroprotection both in vitro and in vivo. Pharmacological or genetic approaches targeting HO-1 may represent a promising and novel therapeutic strategy in treating Parkinsonism
Link stability estimation based on link connectivity changes in mobile ad-hoc networks
No full textDear Wang,
Re: Link Stability Estimation Based on Link Connectivity Changes in Mobile Ad-hoc Networks
I have not been able to assess if this is an author version peer-reviewed or is it an author version non peer reviewed. Could you please clarify this so I can proceed to add your paper to Spiral. Spiral digital repository only accept peer-reviewed papers.
30/11/12 author has confirmed peer reviewe
Dynamics System Modeling Approach in Node Mobility on Mobile Ad-hoc Network
No full textMovement of the nodes in a mobile ad-hoc network is affected by distance and strong transmit / receive signal between neighboring nodes to each other, so how the mobility of the nodes in the network connection can maintain connectivity in the line-of-sight is emerging challenges in the dynamics system. In mobile ad-hoc network each connection connectivity is temporary, so the topology changes that appear along with the mobility of the nodes in constructing communication calls will change the position of the transmitter and receiver. This research has been done on modeling the dynamics system approach for each node mobility scenarios were created based on the selected tests and determined. With quantitative methods used involve tools that can observe the data streaming process in real-time, the results obtained demonstrate the system dynamics can serve to test the mobility of the nodes that occur in mobile ad-hoc network is able to maintain a connection connectivity between each neighboring node
Ad Hoc Positioning System (APS)
No full textMany ad ho network protools and appliations assume the knowledge of geographi loation of nodes. The absolute loation of eah networked node is an assumed fat by most sensor networks whih an then present the sensed information on a geographial map. Finding loation without the aid of GPS in eah node of an ad ho network is important in ases where GPS is either not aessible, or not pratial to use due to power, form fator or line of sight onditions. Loation would also enable routing in suÆiently isotropi large networks, without the use of large routing tables. We are proposing APS { a distributed, hop by hop positioning algorithm, that works as an extension of both distane vetor routing and GPS positioning in order to provide approximate loation for all nodes in a network where only a limited fration of nodes have self loation apability.Technical report DCS-TR-43
Ad exchange design and development
No full textAdvertising adapts and changes over the years as technology advances. Online Advertising became common and gave rise to advertisement exchange. Advertisement exchange can be viewed as a stock market, which involves advertisements rather than stocks. However, current advertisement exchange model consist of major flaws which compromises the effectiveness of advertising. Therefore, a new advertisements exchange model must be created to ensure those flaws can be covered.
Advertisement exchange facilitates Real Time Bidding. Real Time Bidding is a process which will be started when the user enters the webpage. Once a user enters the webpage, a request to fill the webpage’s advertisement slot will be sent through the supply side platform (SSP), which is a system that helps to push the advertisement to the advertisement exchange. On the other hand, advertisers will send advertisement details using demand side platform (DSP), a system which helps to send advertisement information to the advertisement exchange.
At the advertisement exchange, the webpage’s information like content and location will be recorded, and the highest bidder for the advertisement slot that is the most related to the webpage’s content will be granted the advertisement slot. The advertisement will then be displayed on the webpage. The process usually takes 100 milliseconds to complete. However, user demographics such as age, interest of the user can never be obtained by the traditional advertisement exchange model and hence Ad+ Platform proposed a new project; Ad Exchange Design And Development, aiming to remove current flaws and add new features such as applications support features into the new proposed system. The project consist of two main parts, the application and API segments, and there may be more sub parts depending on the changes Ad+ Platform see fit. Hence, this project report will attempt to explain some of the methodologies, strategies, encounters and learning experiences based on the portions that the student was involved.Bachelor of Engineering (Computer Science
HIV and tuberculosis in Ho Chi Minh City, Vietnam, 1997-2002.
No full textIn Ho Chi Minh City, Vietnam, reporting rates for tuberculosis (TB) are rising in an emerging HIV epidemic. To describe the HIV epidemic among TB patients and quantify its impact on rates of reported TB, we performed a repeated cross-sectional survey from 1997 through 2002 in a randomly selected sample of inner city TB patients. We assessed effect by adjusting TB case reporting rates by the fraction of TB cases attributable to HIV infection. HIV prevalence in TB patients rose exponentially from 1.5% to 9.0% during the study period. Young (<35 years), single, male patients were mostly affected; injection drug use was a potent risk factor. After correction for HIV infection, the trend in TB reporting rates changed from a 1.9% increase to a 0.4% decrease per year. An emerging HIV epidemic, concentrated in young, male, injection drug users, is responsible for increased TB reporting rates in urban Vietnam
A multiple-access collision avoidance protocol for multicast services in mobile ad hoc networks
No full textIn order to improve cross-layer optimization, we propose a multiple access collision avoidance protocol that combines RTS/CTS with scheduling algorithms to support the multicast routing protocol. We avoid collision by including additional information in the RTS. Proposed scheme, together with extra benefits, such as power saving, reliable data transmission and higher channel utilization compared with CSMA or multiple unicast, enables the support of multicast services in mobile ad hoc networks.
Cerebral atrophy in mild cognitive impairment and Alzheimer disease: rates and acceleration.
No full textOBJECTIVE: To quantify the regional and global cerebral atrophy rates and assess acceleration rates in healthy controls, subjects with mild cognitive impairment (MCI), and subjects with mild Alzheimer disease (AD). METHODS: Using 0-, 6-, 12-, 18-, 24-, and 36-month MRI scans of controls and subjects with MCI and AD from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, we calculated volume change of whole brain, hippocampus, and ventricles between all pairs of scans using the boundary shift integral. RESULTS: We found no evidence of acceleration in whole-brain atrophy rates in any group. There was evidence that hippocampal atrophy rates in MCI subjects accelerate by 0.22%/year2 on average (p = 0.037). There was evidence of acceleration in rates of ventricular enlargement in subjects with MCI (p = 0.001) and AD (p < 0.001), with rates estimated to increase by 0.27 mL/year2 (95% confidence interval 0.12, 0.43) and 0.88 mL/year2 (95% confidence interval 0.47, 1.29), respectively. A post hoc analysis suggested that the acceleration of hippocampal loss in MCI subjects was mainly driven by the MCI subjects that were observed to progress to clinical AD within 3 years of baseline, with this group showing hippocampal atrophy rate acceleration of 0.50%/year2 (p = 0.003). CONCLUSIONS: The small acceleration rates suggest a long period of transition to the pathologic losses seen in clinical AD. The acceleration in hippocampal atrophy rates in MCI subjects in the ADNI seems to be driven by those MCI subjects who concurrently progressed to a clinical diagnosis of AD
A new MAC algorithm based on reservation and scheduling for energy-limited ad-hoc networks
No full textA wireless ad-hoc network consists of wireless mobile terminals forming a temporary network without any deployed infrastructure or centralized administration. Energy efficiency is an important issue in wireless ad-hoc networks because the battery power of terminals is limited. We propose an energy efficient MAC algorithm based on reservation and scheduling for wireless ad-hoc networks. We evaluate the performance of our proposed MAC scheme with respect to the number of delayed slots, the channel utilization, and the energy efficiency. Then, we derive the fair threshold energy level for the Pseudo Base Station (PBS) reselection in the proposed MAC(1).This work was supported in part by the Korea Science and Engineering Foundation (KOSEF) through the Joint Research Project under The Korea-Japan Basic Scientific Promotion Program, Grant No. 20006-302-02-2
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