PoPeC: PAoI-Centric Task Offloading with Priority over Unreliable Channels

Freshness-aware computation offloading has garnered great attention recently in the edge computing arena, with the aim of promptly obtaining up-to-date information and minimizing the transmission of outdated data. However, most of the existing work assumes that wireless channels are reliable and neglect the dynamics and stochasticity thereof. In addition, varying priorities of offloading tasks along with heterogeneous computing units also pose significant challenges in effective task scheduling and resource allocation. To address these challenges, we cast the freshness-aware task offloading problem as a multi-priority optimization problem, considering the unreliability of wireless channels, the heterogeneity of edge servers, and prioritized users. Based on the nonlinear fractional programming and ADMM-Consensus method, we propose a joint resource allocation and task offloading algorithm to solve the original problem iteratively. To improve communication efficiency, we further devise a distributed asynchronous variant for the proposed algorithm. We rigorously analyze the performance and convergence of the proposed algorithms and conduct extensive simulations to corroborate their efficacy and superiority over the existing baselines

Near-fault mining induced microseismic distribution characteristics and its influencing factors

Rudarene u blizini konstrukcije s greškom može lako dovesti do aktiviranja greške i izazvati ozbiljne geološke poremećaje, predstavljajući ozbiljnu prijetnju sigurnosti proizvodnje uglja. Da bi pokazali karakteristike aktivnosti koje se javljaju u okolnoj stijeni zbog rudarenja u blizini područja s greškom, uzimajući Qixing ugljenokop u Kini kao tehnički ambijent, provela se kontrastivna analiza mikroseizmičkih kretanja u nadgledanom području s greškom na osnovu dobivenih mikroseizmičkih podataka. Promatrano sa stanovišta vrijednosti seizmičkog parametra b i rješenja žarišnog mehanizma, analizirale su se karakteristike širenja mikroseizmičkog događanja i načina loma u ta dva područja. Povećanjem područja rudarenja, provjeravale su se karakteristike razvijanja mikroseizmičkih događanja u okolnoj stijeni pod utjecajem obližnjih konstrukcija s greškom primjenom FLAC3D. Ustanovili smo da je b vrijednost u praćenom području s greškom mnogo niža od one u području nesigurnog rudarenja, što znači da postoji veća opasnost od pojave mikroseizmičkih poremećaja velikog opsega u prvom nego u drugom slučaju. Uz to, razlika u osnovnom naprezanju i elastičnoj energiji u području iskapanja pokazala je karakteristike diskontinuiranog rasprostiranja. Rezultati su pokazali da su postojale neke granične vrijednosti koje su uzrokovale rapidnu promjenu broja mikroseizmičkih pomaka s promjenom faktora kao što su dubina iskapanja, čvrstoća stijene i područje početnog naprezanja. Zaključci su od velike teorijske i praktične vrijednosti za slično rudarstvo.Mining near the fault structure can easily lead to the fault activity and induce serious geological disasters, posing a serious threat to coal mine safety production. To reveal the surrounding rock activity characteristics induced by near-fault mining, taking Qixing Coal Mine in China as the engineering background, the contrastive analysis of the microseismic events in the fault-control area and the mining disturbance area was conducted based on the microseismic monitoring data. From the point of views of seismic parameter b value and focal-mechanism solution, the microseismic event distribution characteristics and the fracture modes in those two areas were analyzed. With the mining area increasing, the evolution characteristics of the microseismic events in the surrounding rock affected by the near-fault structures were verified by using FLAC3D. We found that b value in the fault-control area was much lower than that in the mining disturbance area, indicating that the possibility of large-magnitude microseismic events was greater in the former than that in the latter. Moreover, the principal stress difference and the elastic energy in the mining area displayed the discontinuity distribution charateristics. The results showed that there were some threshold values making the microseismic event numbers change rapidly with these factors variation such as mining depth, rock strength and initial stress field. The conclusions are of important theoretical and practical value for the similar mining engineering

Anti-biofilm formation of a novel stainless steel against Staphylococcus aureus

© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Abstract Staphylococcus aureus (S. aureus) is a bacterium frequently found proliferating on metal surfaces such as stainless steels used in healthcare and food processing facilities. Past research has shown that a novel Cu-bearing 304 type stainless steel (304CuSS) exhibits excellent antibacterial ability (i.e. against S. aureus) in a short time period (24 h.). This work was dedicated to investigate the 304CuSS's inhibition ability towards the S. aureus biofilm formation for an extended period of 7 days after incubation. It was found that the antibacterial rate of the 304CuSS against sessile bacterial cells reached over 99.9% in comparison with the 304SS. The thickness and sizes of the biofilms on the 304SS surfaces increased markedly with period of contact, and thus expected higher risk of bio-contamination, indicated by the changes of surface free energy between biofilm and the steel surfaces. The results demonstrated that the 304CuSS exhibited strong inhibition on the growth and adherence of the biofilms. The surface free energy of the 304CuSS after contact with sessile bacterial cells was much lower than that of the 304SS towards the same culture times. The continuously dissolved Cu2+ ions well demonstrated the dissolution ability of Cu-rich precipitates after exposure to S. aureus solution, from 3.1 ppm (2 days) to 4.5 ppm (7 days). For this to occur, a hypothesis mechanism might be established for 304CuSS in which the Cu2+ ions were released from Cu-rich phases that bond with extracellular polymeric substances (EPS) of the microorganisms. And these inhibited the activities of cell protein/enzymes and effectively prevented planktonic bacterial cells attaching to the 304CuSS metal surface.Peer reviewedFinal Published versio

Long intergenic non-coding RNA 00152 promotes lung adenocarcinoma proliferation via interacting with EZH2 and repressing IL24 expression

Primer sequences. (XLSX 13 kb

Optical effects of spin currents in semiconductors

A spin current has novel linear and second-order nonlinear optical effects due to its symmetry properties. With the symmetry analysis and the eight-band microscopic calculation we have systematically investigated the interaction between a spin current and a polarized light beam (or the "photon spin current") in direct-gap semiconductors. This interaction is rooted in the intrinsic spin-orbit coupling in valence bands and does not rely on the Rashba or Dresselhaus effect. The light-spin current interaction results in an optical birefringence effect of the spin current. The symmetry analysis indicates that in a semiconductor with inversion symmetry, the linear birefringence effect vanishes and only the circular birefringence effect exists. The circular birefringence effect is similar to the Faraday rotation in magneto-optics but involves no net magnetization nor breaking the time-reversal symmetry. Moreover, a spin current can induce the second-order nonlinear optical processes due to the inversion-symmetry breaking. These findings form a basis of measuring a pure spin current where and when it flows with the standard optical spectroscopy, which may provide a toolbox to explore a wealth of physics connecting the spintronics and photonics.Comment: 16 pages, 7 fig

High persistence rate of hepatitis B virus in a hydrodynamic injection-based transfection model in C3H/HeN mice

AIM: To optimize the viral persistence rate in a hydrodynamic injection (HI) based hepatitis B virus (HBV) transfection mouse model.METHODS: (1) 5-6-wk-old male C3H/HeN and C57BL/6 mice were hydrodynamically injected with 10 μg endotoxin-free pAAV/HBV1.2 plasmid DNA via the tail vein. Hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and HBV DNA, both in the serum and liver, were detected at different time points post HI by ELISA, immunohistochemical staining or quantitative polymerase chain reaction (PCR); (2) male C3H/HeN and C57BL/6 mice, either hydrodynamically injected mice at 10 wk post HI or naïve mice, were all immunized subcutaneously with 5 μg HBsAg formulated in complete Freund's adjuvant three times at a 2-wk interval. Two weeks after the final immunization, splenocytes were isolated for T cell function analysis by ELISPOT assay; and (3) five weeks post HI, C3H/HeN mice were intragastrically administered 0.1 mg/kg entecavir once a day for 14 d, or were intraperitoneally injected with 1 mg/kg interferon (IFN)-α twice a week for 2 wk, or were treated with PBS as controls. The sera were collected and assayed for HBV DNA on days 0, 7 and 14 after drug treatment.RESULTS: (1) Approximately 90% (22/25) of the injected C3H/HeN mice were still HBsAg-positive at 46 wk post HI, whereas HBsAg in C57BL/6 mice were completely cleared at 24 wk. Serum levels of HBeAg in C3H/HeN mice were higher than those in C57BL/6 mice from 4 wk to 46 wk. HBV DNA levels in the hydrodynamically injected C3H/HeN mice were higher than those in the C57BL/6 mice, both in the serum (from 4 wk to 46 wk) and in the liver (detected at 8 wk and 46 wk post HI). Histology showed that hepatitis B core antigen and HBsAg were expressed longer in the liver of C3H/HeN mice than in C57BL/6; (2) HBsAg specific T cell responses after HBsAg vaccination in hydrodynamically injected C3H/HeN and C57BL/6 mice, or naive control mice were detected by ELISPOT assay. After stimulation with HBsAg, the frequencies of IFN-γ producing splenocytes in the hydrodynamically injected C3H/HeN mice were significantly lower than those in hydrodynamically injected C57BL/6 mice, control C3H/HeN and control C57BL/6 mice, which were 0, 17 ± 7, 18 ± 10, and 41 ± 10 SFCs/10(6) splenocytes, respectively, and the mean spot sizes showed the same pattern. Even just stimulated with PMA and ionomysin, T-cell responses elicited in the vaccinated control C3H/HeN were much higher than those in hydrodynamically injected C3H/HeN mice; and (3) For drug treatment experiments on the hydrodynamically injected C3H/HeN mice, serum HBV DNA levels in the entecavir treatment group declined (131.2 folds, P &lt; 0.01) on day 7 after treatment and kept going down. In the group of IFN-α treatment, serum HBV DNA levels declined to a lowest point (6.42 folds, P &lt; 0.05) on 7 d after treatment and then rebounded.CONCLUSION: We have developed a novel HI-based HBV transfection model using C3H/HeN mice, which had a higher HBV persistence rate than the classic C57BL/6 mouse model.</p