76 research outputs found
On the objective evaluation of real-time networked games
No full textWith the recent evolution of network-based multiplayer games and the increasing popularity of online games demanding strict real-time interaction among players - like First Person Shooter (FPS) -, game providers face the problem to correlate network conditions with quality of gaming experience. This paper addresses the problem of the estimation gameplay quality during real-time games; in particular, we focus on FPS ones. Current literature usually considers end-to-end delay as the only important parameter and deducts system performance indexes from graphical ones. Player satisfaction, on the other hand, is usually evaluated in a subjective way: asking the player, or measuring how long he/she stays connected. In this paper we use a testbed with synthetic players (bots) to directly correlate network end-to-end delay and jitter with expected players' satisfaction. Running extensive experiments we argue about effective in-game performances degradation of penalized players. Performances are measured in terms of score and number of actions kills, actually - performed per minute
Ensuring fair coexistence of multimedia applications in a wireless home
No full textNowadays, wireless connectivity is increasinglyvailable in homes to support heterogeneous multimedia applications. However, with current off-the-shelf systems, real-time applications (e.g., video streaming, online games) suffer from delays caused by the interference with elastic (e.g., TCP-based downloading sessions) ones. Furthermore, simultaneous elastic application flows are not able to fairly share the same bottleneck, severely damaging those featured with long round-trip times (RTTs). In this article, we discuss how a solution based on a smart access point can actually solve these problems, ensuring low per-packet delays to real-time applications and both high and RTT-fair throughput to elastic ones. We discuss the experimental outcome of our solution showing the benefits achieved with respect to using the legacy protocols and even to adopting a TCP Vegas-based solution, known for providing the same goals we are aiming at
Arachidonic Acid Metabolites of CYP450 Enzymes and HIF-1α Modulate Endothelium-Dependent Vasorelaxation in Sprague-Dawley Rats under Acute and Intermittent Hyperbaric Oxygenation
No full textAcetylcholine-induced vasorelaxation (AChIR) and responses to reduced pO2 (hypoxia-induced relaxation (HIR), 0% O2) were assessed in vitro in aortic rings of healthy male Sprague-Dawley rats (N = 252) under hyperbaric (HBO2) protocols. The studied groups consisted of the CTRL group (untreated); the A-HBO2 group (single HBO2; 120 min of 100% O2 at 2.0 bars); the 24H-HBO2 group (examined 24 h after single exposure) and the 4D-HBO2 group (four consecutive days of single HBO2). AChIR, sensitivity to ACh and iNOS expression were decreased in the A-HBO2 group. HIR was prostanoid- and epoxyeicosatrienoic acid (EET)-mediated. HIF-1α expression was increased in the 24H-HBO2 and 4D-HBO2 groups. LW6 (HIF-1α inhibitor) decreased HIR in the 24H-HBO2 group. HBO2 affected the expression of COX-1 and COX-2. CYP2c11 expression was elevated in the 24H-HBO2 and 4D-HBO2 groups. Concentrations of arachidonic acid (AA) metabolites 14(15)-DiHET, 11(12)-DiHET and 8(9)-DiHET were increased in A-HBO2 and 24H-HBO2. An increased concentration of 8(9)-EET was observed in the A-HBO2 and 24h-HBO2 groups vs. the CTRL and 4D-HBO2 groups, and an increased concentration of 5(6)-DiHET was observed in the 24H-HBO2 group vs. the 4D-HBO2 group. The 20-HETE concentration was increased in the A-HBO2 group. All were determined by LC-MS/MS of the aorta. The results show that AChIR in all groups is mostly NO-dependent. HIR is undoubtedly mediated by the CYP450 enzymes’ metabolites of AA, whereas HIF-1α contributes to restored HIR. Vasoconstrictor metabolites of CYP450 enzymes contribute to attenuated AChIR and HIR in A-HBO2
Acute Hyperbaric Oxygenation, Contrary to Intermittent Hyperbaric Oxygenation, Adversely Affects Vasorelaxation in Healthy Sprague-Dawley Rats due to Increased Oxidative Stress
No full textThe present study was aimed at assessing endothelium-dependent vasorelaxation, at measuring superoxide production in the aorta and femoral artery, and at determining antioxidative enzyme expression and activity in aortas of male Sprague-Dawley rats (N=135), randomized to an A-HBO2 group exposed to a single hyperbaric oxygenation session (120′ of 100% O2 at 2.0 bars), a 24H-HBO2 group (single session, examined 24 h after exposure), a 4D-HBO2 group (4 consecutive days of single sessions), and a CTRL group (untreated group). Vasorelaxation of aortic rings in response to acetylcholine (AChIR) and to reduced pO2 (HIR) was tested in vitro in the absence/presence of NOS inhibitor L-NAME and superoxide scavenger TEMPOL. eNOS, iNOS, antioxidative enzyme, and NADPH oxidase mRNA expression was assessed by qPCR. Serum oxidative stress markers and enzyme activity were assessed by spectrometry, and superoxide production was determined by DHE fluorescence. Impaired AChIR and HIR in the A-HBO2 group were restored by TEMPOL. L-NAME inhibited AChIR in all groups. Serum oxidative stress and superoxide production were increased in the A-HBO2 group compared to all other groups. The mRNA expression of iNOS was decreased in the A-HBO2 and 24H-HBO2 groups while SOD1 and 3 and NADPH oxidase were increased in the 4D-HBO2 group. The expression and activity of catalase and glutathione peroxidase were increased in the 4D-HBO2 group as well. AChIR was NO dependent. Acute HBO2 transiently impaired vasorelaxation due to increased oxidative stress. Vasorelaxation was restored and oxidative stress was normalized 24 h after the treatment.</jats:p
An Enantiomerically Pure Hydrogen-Bonded Assembly
No full textChiral molecules have asymmetric arrangements of atoms, forming structures that are non-superposable mirror images of each other. Specific mirror images ('enantiomers') may be obtained either from enantiomerically pure precursor compounds, through enantioselective synthesis, or by resolution of so-called racemic mixtures of opposite enantiomers, provided that racemization (the spontaneous interconversion of enantiomers) is sufficiently slow. Non-covalent assemblies can similarly adopt chiral supramolecular structures1,2, and if they are held together by relatively strong interactions, such as metal coordination3, methods analogous to those used to obtain chiral molecules yield enantiomerically pure non-covalent products. But the resolution of assemblies formed through weak interactions, such as hydrogen-bonding, remains challenging, reflecting their lower stability and significantly higher susceptibility to racemization. Here we report the design of supramolecular structures from achir..
PENGARUH PENERAPAN GAYA MENGAJAR KOMANDO DAN RESIPROKAL TERHADAP HASIL BELAJAR TENIS
No full textAdapun masalah yang ingin penulis ajukan,tentang apakah terdapat perbedaan diantara gaya mengajar komando dan resprokal terhadap hasil belajar tenis.
Tujuan dari penelitian ini untuk mengetahui seberapa besarkah pengaruh dari dua gaya mengajar tersebut terhadap hasil belajar pembelajaran groundstroke forehand tenis,dan juga untuk mengetahui manakah yang lebih berpengaruh diantara gaya mengajar komando dan resiprokal terhadap hasil belajar tenis. Dalam penelitian ini, penulis menentukan sampel sebanyak 10 orang untuk kelompok komando dan 10 orang untuk kelompok resiprokal.
Setelah penulis melakukan penelitian di dapatkan hasil penghitungan rata-rata sebagai berikut: Dari hasil gain score diperoleh hasil sebagai berikut: Kelompok Komando sebesar (6,00), untuk kelompok Resiprokal (11,6). Kemudian ditemukan t hitung gaya mengajar komando dan gaya mengajar resiprokal adalah 0,74 dengan nilai probabilitas 0,94. Karena 0,94 ˃ 0,05 Maka H0 diterima.
Maka dari itu, Hasil penghitungan uji independent sample t-test adalah hasil belajar kedua gaya mengajar Komando dan Resiprokal tidak berbeda secara nyata. Namun terlihat dari realita di lapangan gaya mengajar komando lebih dominan menangani siswa/peserta didik dalam proses pembelajaran, sehingga tingkat penguasaan anak/siswa/peserta didik di lapangan lebih baik ketimbang gaya mengajar resiprokal.
;---the problem that author want to show is there any difference between reciprocal and command teaching style for the result of learning tennis.
The purpose of this research is to knowing how much the influence from this two tennis style had on the outcome of learning groundstroke forehand tennis, and to define which one is more effective between reciprocal and command teaching style for learning tennis.in this research the author provide 20 people and dived into two group, each group use different teaching style, one for command, and one for reciprocal.
After author did the research, the average calculation is come with following result: Command Group amounting to (6.00), for reciprocal groups (11.6). t the calculation of command style and reciprocal teaching style is 0.74 with a probability value of 0.94. Because 0.94 > 0.05 then H0 is accepted.
Therefore. The calculation independent sample t test result are there is no significantly different,however the realiti teaching style of command more different for student because student can be more understand than using teaching style of resiprocal
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