Association of 6-Minute Walk Performance and Physical Activity With Incident Ischemic Heart Disease Events and Stroke in Peripheral Artery Disease.

BackgroundWe determined whether poorer 6-minute walk performance and lower physical activity levels are associated with higher rates of ischemic heart disease (IHD) events in people with lower extremity peripheral artery disease (PAD).Methods and resultsFive hundred ten PAD participants were identified from Chicago-area medical centers and followed prospectively for 19.0±9.5 months. At baseline, participants completed the 6-minute walk and reported number of blocks walked during the past week (physical activity). IHD events were systematically adjudicated and consisted of new myocardial infarction, unstable angina, and cardiac death. For 6-minute walk, IHD event rates were 25/170 (14.7%) for the third (poorest) tertile, 10/171 (5.8%%) for the second tertile, and 6/169 (3.5%) for the first (best) tertile (P=0.003). For physical activity, IHD event rates were 21/154 (13.6%) for the third (poorest) tertile, 15/174 (8.6%) for the second tertile, and 5/182 (2.7%) for the first (best) tertile (P=0.001). Adjusting for age, sex, race, smoking, body mass index, comorbidities, and physical activity, participants in the poorest 6-minute walk tertile had a 3.28-fold (95% CI 1.17 to 9.17, P=0.024) higher hazard for IHD events, compared with those in the best tertile. Adjusting for confounders including 6-minute walk, participants in the poorest physical activity tertile had a 3.72-fold (95% CI 1.24 to 11.19, P=0.019) higher hazard for IHD events, compared with the highest tertile.ConclusionsSix-minute walk and physical activity predict IHD event rates in PAD. Further study is needed to determine whether interventions that improve 6-minute walk, physical activity, or both can reduce IHD events in PAD

BGP Behavior Monitoring and Analysis

Border Gateway Protocol, an important inter-domain routing protocol, has a number of vulnerabilities. Little is known about how BGP actually performs in today's Internet. We designed a framework, BGP Assistant, to monitor and analyze BGP traffic. Number of BGP Updates and Route convergence time are used to characterize BGP behavior. Preliminary results with the Oregon Route Views BGP show that BGP Assistant can help the network operator to diagnose the network, identify the anomalous ASes or IP prefixes, and respond to them in real time. Further work is in progress to extend its functionalities and better understand BGP behavior

IMECE2009-10875 NUMERICAL SIMULATION OF BOUNDARY LAYER SEPERATION FLOW FOR AIRFOIL IN A WIND TURBINE

ABSTRACT The characteristic of static stall for an airfoil is very important for the design of wind turbine. As long as the detailed information of boundary layer separation flow around an airfoil is obtained, the static stall characteristics could be predicted appropriately. In this paper, both two dimensional (2D) and three dimensional (3D) mathematical models are implemented to simulate fluid flow around a NREL S809 airfoil. The steady state compressible Reynolds-Averaged Navier-Stokes equations are adopted and solved numerically in this paper. Both one-equation and two-equation turbulence models (i.e., Spalart-Allmaras and k-ω Shear Stress Transport models) are adopted, respectively, to solve the turbulent viscosity in this paper. The simulation results show that more detailed vortex structures are obtained by using 3D SpalartAllmaras turbulence model at high attack angle as compared to the two-equation k-ω SST turbulence model, and the obtained aerodynamic performance of an airfoil with Spalart-Allmaras model agrees well with the available experimental data. Therefore, it seems that the 3D Spalart-Allmaras turbulence model is more capable to demonstrate the 3D characteristics of boundary layer separation flow than the k-ω SST model, and it is more efficient to predict the characteristics of static stall for the airfoil. Meanwhile, the simulation results also reveal that the 3D characteristics of separation flow play a very important role for the aerodynamic performance of airfoil after the static stall, and then the 2D mathematical model is no longer suitable to simulate the boundary layer separation flow around the airfoil

Determinants of Perceived Importance of Targeted Transportation Services for Low-Income Riders

It is generally agreed that transit services in disadvantaged neighborhoods can have potentially positive effects on the accessibility of socially excluded or economically marginalized families. The impact of transit services has been quantified by using objective measures, such as travel time, travel cost, and changes in earnings or destinations reached. Although the body of literature on this topic is exhaustive, researchers have acknowledged the importance of more subjective measures associated with trip decision making of individuals. An index of perceived service importance (PSI) was used to study the impact of the subjective dimension of trip making. Riders of transit services were surveyed, and a conceptual model of activity changes that may be enabled by the services of the Job Access Reverse Commute program was designed to facilitate the modeling process. An ordered probit model was developed to explore the relationship between PSI and sociodemographics, service type and characteristics, employment attributes, and travel-related factors. Three models were estimated, and the differences among the models stemmed from the particular subsample used and the effects considered. The results of all three models highlight the importance of the service to frequent users. Time saved, trip length, type of service used, and type of area are somewhat important in explaining PSI, but not in all models. Results indicate that the PSI is indicative of extreme transit dependency, calling for use of these types of measures in addition to hard measures, in evaluating low-income transit services

Involvement of Calcium and Calmodulin in NO-Alleviated Salt Stress in Tomato Seedlings

Salt stress is an adverse impact on the growth and development of plants, leading to yield losses in crops. It has been suggested that nitric oxide (NO) and calcium ion (Ca2+) act as critical signals in regulating plant growth. However, their crosstalk remains unclear under stress condition. In this study, we demonstrate that NO and Ca2+ play positive roles in the growth of tomato (Lycopersicum esculentum) seedlings under salt stress. Our data show that Ca2+ channel inhibitor lanthanum chloride (LaCl3), Ca2+ chelator ethylene glycol-bis (2-aminoethylether)-N,N,N,N-tetraacetic acid (EGTA), or calmodulin (CaM) antagonist N-(6-aminohexyl)-5-chloro-1-naphthalenesulfona-mide hydrochloride (W-7) significantly reversed the effect of NO-promoted the growth of tomato seedlings under salt stress. We further show that NO and Ca2+ significantly decreased reactive oxygen accumulation, increased proline content, and increased the activity of antioxidant enzymes, as well as increased expression of antioxidant enzymes related genes. However, LaCl3, EGTA, and W-7 prevented the positive roles of NO. In addition, the activity of downstream target enzymes related to Ca2+/CaM was increased by NO under salt stress, while LaCl3, EGTA, and W-7 reversed this enhancement. Taken together, these results demonstrate that Ca2+/CaM might be involved in NO-alleviate salt stress