Power-saving method for wireless sensor network

A power saving method of the present invention is provide for a wireless sensor network including a plurality of sensor nodes each transiting between a power saving mode and a transmit/receive mode, determines whether or not there is no transmit or receive data, enters the power saving mode if there is no transmit or receive data, and controls power consumption on the basis of signal-to-noise ratios in the power saving mode. In the power saving method of the present invention, it is possible to minimize the power consumption regardless of nodes density and without an adverse effect on the connectivity of the network, since the sojourn times of the sleep and idle states are determined adaptive to the interference level from neighboring nodes.Board of Regents, University of Texas Syste

Development of Threat Evaluation Tool for Distributed Network Environment

Current information protection systems only detect and warn against individual intrusion, and are not able to provide a collective and synthesized alert message. In this paper, we propose a new Meta-IDS system which is called ``SIA System''. The SIA system can filter redundant alert messages, analyze mixed attacks using correlation alert messages from each sensor and respond to security threats quickly, after classifying them into one of four different statuses. Then we implement the SIA system and test the efficiency of it in the managed networks. Thus we confirm that the SIA system enables security managers to deal with security threats efficiently

Age-related changes of ocular parameters in Korean subjects

Aims: To evaluate the age-related variations of ocular parameters in Korean subjects. Methods: We recruited 314 normal subjects who visited the department of Ophthalmology between January 2007 and October 2007. Refraction, axial length, corneal curvature, white-to-white distance, anterior chamber depth, corneal endothelial cell density, and retinal nerve fiber layer (RNFL) thickness were measured using auto-refractive keratometer, intraocular lens master, noncontact specular microscope, and optical coherence tomography. Result: In correlation analysis, from 19 to 82 years, hyperopic shift showed a strong positive statistical correlation with age (r = 0.553, P < 0.001). Corneal curvatures increased (r = 0.221, P < 0.001), while axial length (r = -0.506, P < 0.001), anterior chamber depth (r = -0.491, P < 0.001) and white-to-white distance (r = -0.205, P < 0.001) decreased with age. Also, corneal endothelial cell density was lower in older patients than in younger patients (r = -0.409, P < 0.001). Compared to younger patients, RNFL thickness was lower in the older patients as well, in all quadrants (superior, r = -0.283, P < 0.001; inferior, r = -0.230, P < 0.001; nasal, r = 0.025, P = 0.676; and temporal, r = -0.393, P < 0.001). According to multiple regression analysis, out of the six parameters measured, only hyperopic shift, anterior chamber depth and corneal endothelial cell density (P, 0.05) had statistically significant correlation with age. Conclusion: Some of the ocular parameters changed with aging. Hyperopic shift, shallowing anterior chamber depth, and reduction of corneal endothelial cell density were only definitely related to age

Improved reversibility in lithium-oxygen battery: Understanding elementary reactions and surface charge engineering of metal alloy catalyst

Most Li-O-2 batteries suffer from sluggish kinetics during oxygen evolution reactions (OERs). To overcome this drawback, we take the lesson from other catalysis researches that showed improved catalytic activities by employing metal alloy catalysts. Such research effort has led us to find Pt3Co nanoparticles as an effective OER catalyst in Li-O-2 batteries. The superior catalytic activity was reflected in the substantially decreased overpotentials and improved cycling/rate performance compared to those of other catalysts. Density functional theory calculations suggested that the low OER overpotentials are associated with the reduced adsorption strength of LiO2 on the outermost Pt catalytic sites. Also, the alloy catalyst generates amorphous Li2O2 conformally coated around the catalyst and thus facilitates easier decomposition and higher reversibility. This investigation conveys an important message that understanding elementary reactions and surface charge engineering of air-catalysts are one of the most effective approaches in resolving the chronic sluggish charging kinetics in Li-O-2 batteries.

A multicenter, prospective, randomized, controlled trial evaluating the safety and efficacy of intracoronary cell infusion mobilized with granulocyte colony-stimulating factor and darbepoetin after acute myocardial infarction: study design and rationale of the 'MAGIC cell-5-combination cytokine trial'

<p>Abstract</p> <p>Background</p> <p>Bone marrow derived stem/progenitor cell transplantation after acute myocardial infarction is safe and effective for improving left ventricular systolic function. However, the improvement of left ventricular systolic function is limited. This study will evaluate novel stem/progenitor cell therapy with combination cytokine treatment of the long-acting erythropoietin analogue, darbepoetin, and granulocyte colony-stimulating factor (G-CSF) in patients with acute myocardial infarction.</p> <p>Methods</p> <p>The 'MAGIC Cell-5-Combination Cytokine Trial' is a multicenter, prospective, randomized, 3-arm, controlled trial with blind evaluation of the endpoints. A total of 116 patients will randomly receive one of the following three treatments: an intravenous darbepoetin infusion and intracoronary infusion of peripheral blood stem cells mobilized with G-CSF (n = 58), an intracoronary infusion of peripheral blood stem cells mobilized with G-CSF alone (n = 29), or conventional therapy (n = 29) at phase I. Patients with left ventricular ejection fraction < 45% at 6 months, in the patients who received stem cell therapy at phase I, will receive repeated cell therapy at phase II. The objectives of this study are to evaluate the safety and efficacy of combination cytokine therapy with erythropoietin and G-CSF (phase I) and repeated progenitor/stem cell treatment (phase II).</p> <p>Discussion</p> <p>This is the first study to evaluate the safety and efficacy of combination cytokine based progenitor/stem cell treatment.</p> <p>Trial registration</p> <p><url>http://www.ClinicalTrials.gov</url> identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00501917">NCT00501917</a>.</p

Association of circulating omentin-1 level with arterial stiffness and carotid plaque in type 2 diabetes

<p>Abstract</p> <p>Background</p> <p>Adipokines contribute directly to the atherosclerotic process, connecting metabolic disorders such as obesity and diabetes to cardiovascular disease. Omentin-1 is a recently discovered novel adipokine, so data about the relationship of this adipokine to vascular health in type 2 diabetes is limited.</p> <p>Methods</p> <p>We enrolled 60 people with type 2 diabetes, with or without carotid plaque, and 30 participants with normal glucose tolerance. We measured serum omentin-1, high-sensitivity C-reactive protein (hsCRP) levels, and the homeostasis model assessment of insulin resistance (HOMA-IR), as well as other cardiovascular risk factors. Vascular health was assessed by brachial ankle pulse wave velocity (baPWV) and carotid intima-media thickness (IMT).</p> <p>Results</p> <p>Serum omentin-1 levels were significantly decreased in type 2 diabetes patients compared to normal glucose controls and was further reduced in type 2 diabetes patients with carotid plaque compared to those without carotid plaque. Multiple stepwise regression analysis showed that age, systolic blood pressure, history of use of statins, angiotensin receptor blockers or angiotensin-converting enzyme inhibitors, and serum omentin-1 level were independent factors determining baPWV in people with type 2 diabetes (<it>r</it>²= 0.637). Furthermore, in multivariate logistic regression analysis, circulating omentin-1 level was an independent decisive factor for the presence of carotid plaque in type 2 diabetes patients, even after adjusting for age, gender, body mass index, systolic blood pressure, fasting blood glucose, low density lipoprotein cholesterol, and history of smoking and medication (odds ratio, 0.621; 95% confidence interval, 0.420-0.919; <it>P </it>= 0.017).</p> <p>Conclusions</p> <p>Circulating omentin-1 level was independently correlated with arterial stiffness and carotid plaque in type 2 diabetes, even after adjusting for other cardiovascular risk factors and detailed medication history.</p