Bidding for Highly Available Services with Low Price in Spot Instance Market

ABSTRACT Amazon EC2 has built the Spot Instance Marketplace and offers a new type of virtual machine instances called as spot instances. These instances are less expensive but considered failure-prone. Despite the underlying hardware status, if the bidding price is lower than the market price, such an instance will be terminated. Distributed systems can be built from the spot instances to reduce the cost while still tolerating instance failures. For example, embarrassingly parallel jobs can use the spot instances by re-executing failed tasks. The bidding framework for such jobs simply selects the spot price as the bid. However, highly available services like lock service or storage service cannot use the similar techniques for availability consideration. The spot instance failure model is different to that of normal instances (fixed failure probability in traditional distributed model). This makes the bidding strategy more complex to keep service availability for such systems. We formalize this problem and propose an availability and cost aware bidding framework. Experiment results show that our bidding framework can reduce the costs of a distributed lock service and a distributed storage service by 81.23% and 85.32% respectively while still keeping availability level the same as it is by using on-demand instances

SIMULATION ANALYSIS OF IMPACT DYNAMIC RESPONSE OF A COAL PLOW BIT

The plow bit is one of the key parts of the coal plow, and is the working part of the coal plow that directly contacts the coal and rock. When plowing the coal, due to the complex and tough coal seam conditions, especially when encountering hard minerals such as hard inclusions, the force on the plow bit increases sharply. The plow bit is impacted, which easily results in the failure of plow bit, such as plow bit head losing, plow bit body broken. And the consumption of plow bit is very large. Therefore, it is important to study the dynamic response of the plow bit when it is impacted during plowing. In this paper, the finite element simulation analysis method is used to conduct in-depth research on the dynamic response of the plow bit under impact. It provides theoretical references for the material selection of plow bit, the design and optimization of plow bit structure, the improvement of plow bit reliability, and the reasonable selection of the working parameters such as plow speed. It is of great significance to the design of China’s coal mining machinery and the development of coal industry

Intranasal B5 promotes mucosal defence against Actinobacillus pleuropneumoniae via ameliorating early immunosuppression

ABSTRACTActinobacillus pleuropneumoniae (APP) is an important pathogen of the porcine respiratory disease complex, which leads to huge economic losses worldwide. We previously demonstrated that Pichia pastoris-producing bovine neutrophil β-defensin-5 (B5) could resist the infection by the bovine intracellular pathogen Mycobacterium bovis. In this study, the roles of synthetic B5 in regulating mucosal innate immune response and protecting against extracellular APP infection were further investigated using a mouse model. Results showed that B5 promoted the production of tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and interferon (IFN)-β in macrophages as well as dendritic cells (DC) and enhanced DC maturation in vitro. Importantly, intranasal B5 was safe and conferred effective protection against APP via reducing the bacterial load in lungs and alleviating pulmonary inflammatory damage. Furthermore, in the early stage of APP infection, we found that intranasal B5 up-regulated the secretion of TNF-α, IL-1β, IL-17, and IL-22; enhanced the rapid recruitment of macrophages, neutrophils, and DC; and facilitated the generation of group 3 innate lymphoid cells in lungs. In addition, B5 activated signalling pathways associated with cellular response to IFN-β and activation of innate immune response in APP-challenged lungs. Collectively, B5 via the intranasal route can effectively ameliorate the immune suppression caused by early APP infection and provide protection against APP. The immunization strategy may be applied to animals or human respiratory bacterial infectious diseases. Our findings highlight the potential importance of B5, enhancing mucosal defence against intracellular bacteria like APP which causes early-phase immune suppression

Community-based interventions to enhance knowledge, protective attitudes and behaviors towards canine rabies: results from a health communication intervention study in Guangxi, China

Background: In China canine rabies poses a serious public health problem in that human mortality ranks the second highest globally. While rabies health education interventions are advocated by WHO to be critical components of modern rabies control and prevention programs, available studies have not adequately investigated the relative efficacy of their implementation in at-risk populations. This study aims to measure and compare the effect on knowledge and protective behavior towards rabies of health education interventions that include a novel Short Messaging Service via cell phone (SMS) and rabies health information sessions (IS). Methods: The study used a between-subject design involving repeated measures of rabies-related KAP (knowledge, attitude and practice). A total of 350 randomly selected villagers were randomly allocated into three intervention (SMS, IS and SMS + IS) and one control group. The content of SMS and IS covered topics about rabies prevention and route of transmission. The SMS intervention consisted of ten separate messages delivered three times two weeks after the pretest; the IS intervention was conducted once immediately after the pretest. A validated questionnaire was used to capture demographic information and KAP information. Ordinary Least Squares regression was used to contrast the effects of interventions. Results: Our results indicate that overall SMS outperforms IS at improving knowledge and protective behavior against rabies. Our results suggest that a combined intervention of SMS and IS can result in higher scores than any of the two in isolation. The impact of SMS, IS and SMS + IS is greatest on knowledge, followed by attitude and practice scores. Conclusion: This study demonstrated that health communication modes based on SMS, IS and a combination of the two are all effective to improve rabies-related KAP in the short term. These findings highlight the potential usefulness of SMS as an additional tool for public health communication and promotion; further studies are needed to investigate the long term benefits of these interventions on the reduction of dog bites and resulting human rabies incidence

Variance analysis of the effects of block, Al, P, and clone on enzyme activities in roots.

<p>Variance analysis of the effects of block, Al, P, and clone on enzyme activities in roots.</p

The randomized block design of different Al-P-clone treatments.

<p>The randomized block design of different Al-P-clone treatments.</p

Variance analysis of the effects of block, Al, P, and clone on Al-induced secretion of organic acids from roots.

<p>Variance analysis of the effects of block, Al, P, and clone on Al-induced secretion of organic acids from roots.</p

Variance analysis of the effects of block, Al, P, and clone on the root, stem, and leaf DWs, and root/shoot DW ratio of seedlings.

<p>Variance analysis of the effects of block, Al, P, and clone on the root, stem, and leaf DWs, and root/shoot DW ratio of seedlings.</p