171 research outputs found

    POEM: Pricing Longer for Edge Computing in the Device Cloud

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    Multiple access mobile edge computing has been proposed as a promising technology to bring computation services close to end users, by making good use of edge cloud servers. In mobile device clouds (MDC), idle end devices may act as edge servers to offer computation services for busy end devices. Most existing auction based incentive mechanisms in MDC focus on only one round auction without considering the time correlation. Moreover, although existing single round auctions can also be used for multiple times, users should trade with higher bids to get more resources in the cascading rounds of auctions, then their budgets will run out too early to participate in the next auction, leading to auction failures and the whole benefit may suffer. In this paper, we formulate the computation offloading problem as a social welfare optimization problem with given budgets of mobile devices, and consider pricing longer of mobile devices. This problem is a multiple-choice multi-dimensional 0-1 knapsack problem, which is a NP-hard problem. We propose an auction framework named MAFL for long-term benefits that runs a single round resource auction in each round. Extensive simulation results show that the proposed auction mechanism outperforms the single round by about 55.6% on the revenue on average and MAFL outperforms existing double auction by about 68.6% in terms of the revenue.Comment: 8 pages, 1 figure, Accepted by the 18th International Conference on Algorithms and Architectures for Parallel Processing (ICA3PP

    Complement blockade with eculizumab to treat acute symptomatic humoral rejection after heart transplantation.

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    Antibody-mediated rejection (AMR) is a major barrier preventing successful discordant organ xenotransplantation, but it also occurs in allotransplantation due to anti-HLA antibodies. Symptomatic acute AMR is rare after heart allograft but carries a high risk of mortality, especially >1 year after transplant. As complement activation may play a major role in mediating tissue injury in acute AMR, drugs blocking the terminal complement cascade like eculizumab may be useful, particularly since "standards of care" like plasmapheresis are not based on strong evidence. Eculizumab was successfully used to treat early acute kidney AMR, a typical condition of "active AMR," but showed mitigated results in late AMR, where "chronic active" lesions are more prevalent. Here, we report the case of a heart recipient who presented with acute heart failure due to late acute AMR with eight de novo donor-specific anti-HLA antibodies (DSA), and who fully recovered allograft function and completely cleared DSA following plasmapheresis-free upfront eculizumab administration in addition to thymoglobulin, intravenous immunoglobulins (IVIG), and rituximab. Several clinical (acute onset, abrupt and severe loss of graft function), biological (sudden high-level production of DSA), and pathological features (microvascular injury, C4d deposits) of this cardiac recipient are shared with early kidney AMR and may indicate a strong role of complement in the pathogenesis of acute graft injury that may respond to drugs like eculizumab. Terminal complement blockade should be further explored to treat acute AMR in recipients of heart allografts and possibly also in recipients of discordant xenografts in the future

    Has the profile of heart transplantation recipients changed within the last three decades?

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    Heart transplantation remains the most durable treatment for patients with end-stage heart failure refractory to medical treatment. Central elements of the listing criteria for heart transplantation have remained largely unchanged in the last three decades whereas treatment of heart failure has significantly increased survival and reduced disease-related symptoms. It remains unknown whether the improvement of heart failure therapy changed the profile of heart transplantation candidates or affected post-transplant survival. The study investigated a total of 323 heart transplant recipients of the Lausanne University Hospital with 328 transplant operations between 1987 and 2018. Patients were separated into three groups on the basis of availability of heart failure therapy: period 1 (1987-1998; n = 115) when renin-angiotensin system blockade and diuretic treatment were available; period 2 (1999-2010; n = 106) marked by the addition of beta-blocker and mineralocorticoid receptor antagonist treatment in severe heart failure, and the establishment of cardiac defibrillator and resynchronisation therapy; period 3 (2011-2018; n = 107) characterised by the increasing use of ventricular assist devices for bridge to transplantation. The patient characteristics age (all: 53.4 years), male sex (all: 79%) and body mass index (all: 24.5 kg/m2) did not differ between periods. History of arterial hypertension was less prevalent in period 2 (period 1 vs 2 vs 3: 44 vs 28 vs 43%, p = 0.04) whereas other cardiovascular risk factors were equally distributed. Left ventricular ejection fraction, VO2max, and pulmonary vascular resistance were not different between the three periods. The prevalence of ischaemic cardiomyopathy was higher in periods 1 and 3; dilated non-ischaemic cardiomyopathy was more frequent in period 2. Post-transplant 1-year survival was highest in period 3 (1 vs 2 vs 3: 87.2 ± 3.2% vs 70.8 ± 4.4% vs 93.0 ± 2.6%, p always ≤0.02), and the Kaplan-Meier estimates of survivors of the first year post-transplant were not different between the three periods. In descriptive analysis, early mortality was not associated with acknowledged pretransplant predictors of post-transplant mortality. Availability of different medical heart failure treatments did not result in greatly different pretransplant characteristics of heart transplantation recipients across the three periods. This suggests that the maintained central criteria of listing for heart transplantation still identify end-stage heart failure patients with a similar profile. This finding can explain the unchanged overall mortality on condition of 1-year survival across the three periods, since pretransplant characteristics are relevant for long-term survival after heart transplantation

    Decongestion improving right heart function ameliorates prognosis after an acute heart failure episode.

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    The prognostic role of decongestion-related change of cardiac morphology and in particular right heart function has not been investigated comprehensively in AHF patients. This prospective observational single-centre study included consecutive patients hospitalized for treatment of AHF with reduced, mildly-reduced or preserved left ventricular ejection fraction (LVEF). Comprehensive transthoracic echocardiography at admission and discharge assessed decongestion-related change of cardiac function and morphology. The combined endpoint of 1 year all-cause mortality and cardiovascular rehospitalization explored the prognostic importance of decongestion-related change. The 176 study participants were 83 years old [74-87] and 54% were men. Fifty one (29%) had rLVEF, 65 (37%) mrLVEF, and 60 (34%) pLVEF. The proportion of de novo or worsening chronic HF was not different between LVEF groups. HF aetiology and cardiovascular risk factors were equally distributed across all groups except for a higher BMI in the pLVEF group. Decongestion equally reduced body weight, heart rate, systolic and diastolic blood pressure, tricuspid regurgitation gradient, and inferior vena cava diameter across all groups (P < 0.004 for all). Decongestion-related increase in TAPSE independent of the LVEF was associated with improvement of right-ventricular-pulmonary artery coupling and a lower incidence of the combined outcome in the Cox proportional hazard risk analysis (unadjusted HR 0.50 95% CI 0.33-0.78, P = 0.002; adjusted HR 0.46 95% CI: 0.33-0.78, P = 0.001). Decongestion-related increase in TAPSE and recovery of RV/pulmonary artery coupling was observed across all LVEF groups and associated with a risk reduction for the combined endpoint highlighting the important prognostic role of right heart recovery after an AHF episode

    Analysis of associated risk factors among recurrent cutaneous leishmaniasis patients: A cross-sectional study in Khyber Pakhtunkhwa, Pakistan

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    Background Leishmaniasis is the second and fourth highest cause of mortality and morbidity respectively among all tropical diseases. Recurrence in the onset of leishmaniasis is a major problem that needs to be addressed to reduce the case fatality rate and ensure timely clinical intervention. Here we are investigating the association of risk factors with recurrent cutaneous leishmaniasis to address this issue. Material and methods Patients received by Nasser Ullah Khan Babar Hospital in Peshawar, Pakistan from March 2019 to July 2020 were enrolled in this study. Those patients who developed symptoms after completion of treatment were included in Group-A while those who had atypical scars like leishmaniasis but were negative for cutaneous leishmaniasis were included in the comparison group tagged as Group B. All those individuals who had completed six weeks of treatment for CL but had normal complete blood counts (CBC) were included to avoid other underlying immunological pathologies, while we excluded those participants who had co-morbidities like diabetes, liver disease, cardiac disease, and pregnant and lactating women through their history Association was tested between Group-A and Group-B with other explanatory variables through chi-square test. The regression model was proposed to determine the predictors. Result A total of 48 participants of both sexes were included in the study with a mean age of 32.2 ± 15.10. The data suggest that females are overrepresented among the patients with recurrent leishmaniasis [21(53.8 %,); p = 0.07]. Compared to patients; healthy participants had a higher proportion of adults (19–59 years) versus adolescents (13–18 years) [26(66.7 %) vs 07(17.9), p = 0.004]. Multivariate logistic regression analysis shows that females are 2.1 times more prone to infections among cases as compared to healthy individuals [unadjusted OR 2.20, 95 % confidence interval (CI) 1.5–10.6, p = 0.02; adjusted OR 2.1, 95 % CI 1.50–10.69, p = 0.02]. We propose that patients receiving intradermal were less likely to be infected as compared to those receiving intralesional injections [unadjusted OR 0.07.0, 95 % confidence interval (CI) 1.18–3.37, p = 0.03; adjusted OR 0.06, 95 % CI 1.18–3.38, p = 0.03]. Conclusion Old age (adults) and sex (females) were the strongest predictors to be associated with recurrent leishmaniasis. Similarly, the choice of intradermal as compared to intralesional injection and the prolonged treatment duration were strongly associated with greater chances of recurrence

    Deciphering the genome structure and paleohistory of _Theobroma cacao_

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    We sequenced and assembled the genome of _Theobroma cacao_, an economically important tropical fruit tree crop that is the source of chocolate. The assembly corresponds to 76% of the estimated genome size and contains almost all previously described genes, with 82% of them anchored on the 10 _T. cacao_ chromosomes. Analysis of this sequence information highlighted specific expansion of some gene families during evolution, for example flavonoid-related genes. It also provides a major source of candidate genes for _T. cacao_ disease resistance and quality improvement. Based on the inferred paleohistory of the T. cacao genome, we propose an evolutionary scenario whereby the ten _T. cacao_ chromosomes were shaped from an ancestor through eleven chromosome fusions. The _T. cacao_ genome can be considered as a simple living relic of higher plant evolution

    Evaluation of the color stability of two techniquesfor reproducing artificial irides after microwave polymerization

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    The use of ocular prostheses for ophthalmic patients aims to rebuild facial aesthetics and provide an artificial substitute to the visual organ. Natural intemperate conditions promote discoloration of artificial irides and many studies have attempted to produce irides with greater chromatic paint durability using different paint materials. OBJECTIVES: The present study evaluated the color stability of artificial irides obtained with two techniques (oil painting and digital image) and submitted to microwave polymerization. MATERIAL AND METHODS: Forty samples were fabricated simulating ocular prostheses. each sample was constituted by one disc of acrylic resin N1 and one disc of colorless acrylic resin with the iris interposed between the discs. The irides in brown and blue color were obtained by oil painting or digital image. The color stability was determined by a reflection spectrophotometer and measurements were taken before and after microwave polymerization. Statistical analysis of the techniques for reproducing artificial irides was performed by applying the normal data distribution test followed by 2-way ANOVA and Tukey HSD test (α=.05). RESULTS: Chromatic alterations occurred in all specimens and statistically significant differences were observed between the oil-painted samples and those obtained by digital imaging. There was no statistical difference between the brown and blue colors. Independently of technique, all samples suffered color alterations after microwave polymerization. CONCLUSION: The digital imaging technique for reproducing irides presented better color stability after microwave polymerization

    Effects of different surface treatments and accelerated artificial aging on the bond strength of composite resin repairs

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    Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)The purpose of the present study was to assess the bond strength of composite resin repairs subjected to different surface treatments and accelerated artificial aging. 192 cylindrical samples (CSs) were prepared and divided into 24 groups (n = 8). Half of the CSs were stored in water for 24 h, and the other half were subjected to C-UV accelerated aging for non-metallic specimens. The treatments were phosphoric acid + silane + adhesive (PSA); phosphoric acid + adhesive (PA); diamond bur + phosphoric acid + silane + adhesive (DPSA); diamond bur + phosphoric acid + adhesive (DPA); air abrasion + phosphoric acid + silane + adhesive (APSA); and air abrasion + phosphoric acid + adhesive (APA). The repair was performed and the specimens were again aged as described above. A control group (n = 8) was established and did not receive any type of aging or surface treatment. The specimens were loaded to failure in shear mode with a crosshead speed of 0.5 mm/min until fracture. Data were analyzed by one-way ANOVA/Tukey's test (p < 0.05). No statistically significant differences were found among DPSA, DPA, APSA, APA, and the control group. The aged PSA and PA achieved low bonding values and were statistically different from the control group, whereas the non-aged PSA and PA presented no statistically significant difference from the control group. Repairs with the proposed surface treatments were viable on both recent and aged restorations; however, phosphoric acid + adhesive alone were effective only on recent restorations

    Efect of maleated anhydride on mechanical properties of rice husk filler reinforced PLA Matrix Polymer Composite

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    Polylactic acid (PLA) formulated from corn starch has a bright potential to replace the non-renewable petroleum-based plastics. The combination of PLA and natural fbre has gained interest due to its unique performance, as reported in many researches and industries. Meanwhile, rice husk produced as the by-product of rice milling can be utilised, unless it is turned completely into waste. Therefore, in the present study, the rice husk powder (RHP) was used as a fller in the PLA, so to determine the infuence of the fller loading on the mechanical properties of the PLA composite. A coupling agent was selected for treatment from two options, i.e., maleic anhydride polypropylene (MAPP) and maleic anhydride polyethylene (MAPE), by applying the agents with various loading contents, such as 2, 4 and 6 wt%. The composite was fabricated by using the hot compression machine. Both the treated and untreated RHP–PLA composites were characterised via the tensile, fexural and impact strength tests. The increase in the RHP loading content led to the decrease in the tensile and fexural strengths. The applications of the coupling agents (MAPE and MAPP) did not improve the tensile and impact strengths, but the fexural strength was enhanced
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