77 research outputs found
Temporal walk based centrality metric for graph streams
Abstract A plethora of centrality measures or rankings have been proposed to account for the importance of the nodes of a network. In the seminal study of Boldi and Vigna (2014), the comparative evaluation of centrality measures was termed a difficult, arduous task. In networks with fast dynamics, such as the Twitter mention or retweet graphs, predicting emerging centrality is even more challenging. Our main result is a new, temporal walk based dynamic centrality measure that models temporal information propagation by considering the order of edge creation. Dynamic centrality measures have already started to emerge in publications; however, their empirical evaluation is limited. One of our main contributions is creating a quantitative experiment to assess temporal centrality metrics. In this experiment, our new measure outperforms graph snapshot based static and other recently proposed dynamic centrality measures in assigning the highest time-aware centrality to the actually relevant nodes of the network. Additional experiments over different data sets show that our method perform well for detecting concept drift in the process that generates the graphs
ethp2psim: Evaluating and deploying privacy-enhanced peer-to-peer routing protocols for the Ethereum network
Network-level privacy is the Achilles heel of financial privacy in
cryptocurrencies. Financial privacy amounts to achieving and maintaining
blockchain- and network-level privacy. Blockchain-level privacy recently
received substantial attention. Specifically, several privacy-enhancing
technologies were proposed and deployed to enhance blockchain-level privacy. On
the other hand, network-level privacy, i.e., privacy on the peer-to-peer layer,
has seen far less attention and development. In this work, we aim to provide a
peer-to-peer network simulator, ethp2psim, that allows researchers to evaluate
the privacy guarantees of privacy-enhanced broadcast and message routing
algorithms. Our goal is two-fold. First, we want to enable researchers to
implement their proposed protocols in our modular simulator framework. Second,
our simulator allows researchers to evaluate the privacy guarantees of
privacy-enhanced routing algorithms. Finally, ethp2psim can help choose the
right protocol parameters for efficient, robust, and private deployment
Relevance of novel inflammatory markers in stroke-induced immunosuppression
BACKGROUND: Acute ischemic stroke (AIS) has a biphasic effect on the peripheral immune system. The initial inflammatory response is followed by systemic immunosuppression, referred to as stroke-induced immunosuppression (SIIS), leading to severe complications in stroke patients. We aimed to identify an inflammatory marker that best represents this biphasic immunological response after AIS. METHODS: We investigated the alteration of CRP, WBC, neutrophil count, suPAR levels, CD4+ CD25high Tregs, CD64+ and CD177+ neutrophils and monocytes in 12 acute ischemic stroke patients free of infection within 6 hours and one week after the insult. As controls, 14 age-matched healthy individuals were included. RESULTS: CRP, WBC and neutrophil count values were comparable in stroke patients within 6 hours and controls, however, they were elevated in stroke one week after the insult. suPAR levels were higher in both stroke groups compared to controls. The prevalence of CD64+ neutrophils was higher in stroke patients within 6 hours than in controls and it decreased in stroke one week after the insult below the level in controls (5.95 [5.41-8.75] % vs. 32.38 [9.21-43.93] % vs. 4.06 [1.73-6.77] %, p < 0.05). CONCLUSIONS: Our pilot study identified that the prevalence of CD64+ neutrophils may reflect a biphasic alteration of the immune response following AIS. Since its level decreases below baseline after one week of the CNS insult in stroke patients without infection, it might serve as a reliable candidate to identify the developing inflammatory response due to infection after stroke in the future
Effects of aerobic workout on the changes in the characteristics of dynamics of the center of gravity in different age categories
Introduction The quality and function of movements undergo deterioration due to weight gain. Aerobic training normalizes body weight, improves the health status, and in addition, it is expected to improve the dynamics of movements. The aims of this study were to prove the beneficial effects of recreational physical activities on the movements. Methods Participants were divided into five different age categories: second childhood, adolescence, mature age I, mature age II, and aging. Squatting and vertical jumping of the participants were measured at the beginning and at the end of a 5-month training program. These movements simulated ordinary daily movements. Changes in the body were determined by InBody230. APAS 3D system was used for movement analysis. Results The results showed significant improvements in body weight, fat mass, muscle mass, fat mass–body weight ratio, muscle mass–body weight ratio, body mass index, body fat percentage, and waist–hip ratio. During jumping, the lifting and sinking of the center of gravity’s (CG) position and its velocity and acceleration were improved. In case of squatting, the results showed significant improvements in the velocity and acceleration of dynamical characteristics of the CG. Other correlations were observed between changes in body composition and the dynamics of movements. Discussion The research proved that recreational training optimized body composition and improved the characteristics of CG’s dynamics. The study suggests considerable connection between body composition and the characteristics of the movements’ dynamics. From this point of view, our training program was the most effective in the working age groups
Energy-Availability-QoS Trade-off for Future Converged Fixed-Mobile Networks
Abstract-In the access part of the Future Internet the fixed and mobile access is expected to converge not only to better utilize the resources, but also to decrease the power consumption, to increase the availability and also to improve the QoS/QoE of uesrs. We present architectures and algorithms to show what EnergyAvailability-QoS tradeoffs can be reached. We support our approach by intensive simulations. The electric energy consumption [kWh] grows from year to year. The share of InfoCommunications Technologies (ICT) grows even faster. In this paper we focus primarily onto reducing energy consumption of the access part of modern heterogeneous mobile networks that leads to "greening" of this part of the network. The idea of our "greening" algorithm is based on selective switch-off and on consolidation of resources, employed jointly with both, the vertical and the horisontal handover (handoff). We show by simulations the energy saving benefits of our approach
Effects of a single aerobic exercise session on body image
Background and Objectives
Most research on the effects of exercise on body image has concentrated on the benefits of regular exercise. However, some research has indicated that exercise has an immediate impact on body image. The aims of this study were to investigate the immediate effects of aerobic exercise in a fitness class and the at-home environment on body image, and to examine the impact of nutritional status (i.e., normal weight vs. overweight/obesity) and exercise addiction on these changes.
Method
322 Hungarian women participated in the study with two different environmental conditions, fitness class condition (N = 155) and at-home video condition (N = 167). They completed the Body Appreciation Scale and Exercise Addiction Inventory before and after a one-hour aerobic exercise session. Self-report data on weight, height and exercise frequency were also collected.
Results
There were no significant differences between the fitness class and video groups in terms of age, educational level, BMI, body appreciation, exercise frequency and exercise addiction. We found that 7.5% (N = 24) of the participants were at risk for exercise addiction. Aerobic exercise had a significant positive effect on body appreciation (t(321) = 7.564, p < .001) independently from environment and nutritional status. Exercise addiction moderated the relationship between exercise and body image, the at risk for exercise addiction group showed the greatest improvement (F(1) = 3.252, p = .040).
Conclusion
The results indicate that even a one-hour aerobic exercise session has a positive effect on body image; this has important practical implications for intervention strategies and weight-loss treatments.
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Elméleti háttér és célkitűzés
Bár a legtöbb kutatás a rendszeres testedzés testképre gyakorolt pozitív hatására fókuszál, néhány vizsgálat eredménye a testedzés testképre tett azonnali hatására hívja fel a figyelmet. Jelen tanulmány célja az aerobik edzés testképre gyakorolt azonnali hatásának vizsgálata fitnesztermi és otthoni edzési körülmények között, továbbá a tápláltsági állapot (normális testsúly vs. túlsúly/elhízás) és a testedzésfüggőség potenciális moderátor szerepének vizsgálata az edzés és a testkép alakulása közötti kapcsolatban.
Módszer
A vizsgálatba aerobikedzést folytató nőket vontunk be (n = 322). A résztvevők egyik része edzőteremben folytatta a testgyakorlást (n = 155), másik része otthon végzett aerobik testedzést, video vagy DVD segítségével (n = 167).
Mérőeszközök
önbeszámolóval nyert testtömeg és testmagasság, a testedzés gyakoriságára vonatkozó kérdés, Testértékelési Skála, Testedzés Addikció Kérdőív. Az adatfelvétel az egyórás testgyakorlást megelőzően és azt követően történt.
Eredmények
Nem találtunk szignifikáns különbséget az edzőteremben és az otthonukban aerobik edzést folytató nők között az életkor, az iskolai végzettség, a BMI, a testértékelés, a testedzés gyakorisága és a testedzésfüggőség tekintetében. A válaszadók 7,5%-a (n = 24) esetében jelenik meg a testedzésfüggőség kockázata. Az egyórás testedzés szignifikáns, kedvező hatást gyakorolt a testképre (t(321) = 7,564; p < 0,001), amely hatás a testgyakorlás helyszínétől (edzőterem vs. otthon) és a tápláltsági állapottól függetlennek bizonyult. A testedzésfüggőség azonban moderálta a testgyakorlás és a testkép változásának kapcsolatát: a testedzést követően a testedzésfüggőség szempontjából veszélyeztetett csoportban mutatkozott meg a legnagyobb mértékű, pozitív irányú változás a testkép tekintetében (F(1) = 3,252; p = 0,040).
Következtetés
Eredményeink arra utalnak, hogy akár egy egyórás testgyakorlásnak is pozitív hatása lehet a testképre, amelynek jelentős gyakorlati implikációi vannak a testsúlycsökkentő kezelések szempontjából
Solid-Phase Quasi-Intramolecular Redox Reaction of [Ag(NH3)2]MnO4: An Easy Way to Prepare Pure AgMnO2
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