Real-time hierarchical hypervisor

textBoth real-time virtualization and recursive virtualization are desirable properties of a virtual machine monitor (or hypervisor). Although the prospect for virtualization and even recursive virtualization has become better as the PC hardware becomes faster, the real-time systems community so far has not been able to reap much benefits. This is because no existing virtualization mechanism can properly support the stringent timing requirements needed by real-time systems. It is hard to do real-time virtualization, and it is even harder to do it recursively. In this dissertation, we propose a framework whereby the hypervisor is capable of running real-time guests and participating in recursive virtualization. Such a hypervisor is called a real-time hierarchical hypervisor. We first look at virtualization of abstract resource types from the real-time systems perspective. Unlike the previous work on recursive real-time partitioning that assumes fully-preemptable resources, we concentrate on other and often more practical types of scheduling constraints, especially the non-preemptive and limited-preemptive ones. Then we consider the current x86 architecture and explore the problems that need to be addressed for real-time recursive virtualization. We drill down on the problem that affects timing properties the most, namely, the recursive forwarding and delivery of interrupts, exceptions and intercepts. We choose the x86 architecture because it is popular and readily available, but it is by no means the only architecture of choice for real-time recursive virtualization. We conclude the research with an architecture-independent discussion on future possibilities in real-time recursive virtualization.Computer Science

Human Pluripotent Stem Cells in Cardiovascular Research and Regenerative Medicine

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How Ontologies Can Help in an eMarketplace

Recently, ontologies have been developed in various business domains with the recent maturing of the Semantic Web technologies. However, ontology-related researches have largely focused on the facilitation of successful matchmaking but not much on traders’ requirement elicitation and potential negotiations in e-marketplaces. Because ontology provides the key knowledge about the inter-relationships among the issues and alternatives of the traders’ requirements, we show how to elicit trade requirements, alternatives, and tradeoff from an agreed ontology. This facilitates the whole business process of the e-marketplace, from matchmaking, recommendation, to negotiation. We further propose a novel methodology for the elicitation of dependencies among traders’ requirements for the formulation of an effective decision plan. As a result, traders can have a better cognition of their requirements and the overall operations of the e-marketplace can be streamlined

An International Collaborative Consensus Statement on En Bloc Resection of Bladder Tumour Incorporating Two Systematic Reviews, a Two-round Delphi Survey and a Consensus Meeting

Funding/Support and role of the sponsor: This study was supported by the General Research Fund/Early Career Scheme of the Research Grants Council, Hong Kong, China (reference no. 24116518).Peer reviewedPostprin

An exploratory study of using hydrogen peroxide as oxygen source in aerobic upflow sludge blanket reactor

The normal biomass level in the conventional activated sludge reactor is generally limited to between 2,000 and 3,000 mg/L due to the oxygen transfer limitation and the need for effective sludge settling in the secondary clarifier. In order to eliminate these two constraints, an exploratory study has been carried out to use hydrogen peroxide as the oxygen source in a non-aerated sludge blanket reactor containing a biomass level of 18,000-52,000 mg/L. The thick sludge blanket can effectively retain most of the produced bio-solids, leaving an effluent with SS levels between 50 and 350 mg/L, which may be polished by settling, micro-straining, or even slow sand filtration for small treatment plants. It has been found that an influent dosing of 800 mg/L H2O2 does not induce any peroxide toxicity. This dosing provides an oxygen supply of 376 mg/L, which can satisfy a theoretical COD removal of 750 mg/L based on a cell yield coefficient of 0.50. Of course, the actual COD removal is somewhat lower because a portion of the oxygen supply is consumed by biomass respiration. In treating a synthetic influent containing a TOC of 300 to 500 mg/L (with a COD/TOC ratio of 2.65) and an HRT of 0.33 to 1.0 hour, the reactor can accept an organic loading of up to 36 kgTOC/m3-day (over 50 times higher than the conventional activated sludge system) with a 50% organic removal efficiency. When the loading rate is reduced to 7.2 kgTOC/m3-day, the efficiency increases to 82%. Actually, the extent of TOC removal is largely dictated by the level of peroxide dosing since in this type of reactor, the biomass level is very high and the organic stabilization rate is not dictated by microbial activities. The capital requirement for such a compact reactor is less than 5% of that for the conventional activated sludge plant since its reactor volume is only 2 to 3% of the aeration tank, and there is no need for blowers or other aeration equipment. The operating cost is higher as 1.0 kg of oxygen supply from peroxide is about HK$12/kgO2, while that from diffuser aeration is only HK$1.5 to HK$2.0/kgO2. Nevertheless, for a small plant with a treatment capacity of 500 m3/day treating an influent COD of 500 mg/L, the daily oxygen required is only 112.5 kg/day (equivalent to a peroxide cost of HKD$1,350/day or HK$2.7/m3) , which can be easily offset by the tremendous capital saving for the plant installation. Keywords: Intensified biological rector; compact technology, aerobic sludge blanket reactor; hydrogen peroxide as oxygen source; low capital treatment

Comparison of Direct Sequencing, Real-Time PCR-High Resolution Melt (PCR-HRM) and PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) Analysis for Genotyping of Common Thiopurine Intolerant Variant Alleles NUDT15 c.415C>T and TPMT c.719A>G (TPMT*3C)

Thiopurine intolerance and treatment-related toxicity, such as fatal myelosuppression, is related to non-function genetic variants encoding thiopurine S-methyltransferase (TPMT) and Nudix hydrolase 15 (NUDT15). Genetic testing of the common variants NUDT15:NM_018283.2:c.415C>T (Arg139Cys, dbSNP rs116855232 T allele) and TPMT: NM_000367.4:c.719A>G (TPMT*3C, dbSNP rs1142345 G allele) in East Asians including Chinese can potentially prevent treatment-related complications. Two complementary genotyping approaches, real-time PCR-high resolution melt (PCR-HRM) and PCR-restriction fragment length morphism (PCR-RFLP) analysis were evaluated using conventional PCR and Sanger sequencing genotyping as the gold standard. Sixty patient samples were tested, revealing seven patients (11.7%) heterozygous for NUDT15 c.415C>T, one patient homozygous for the variant and one patient heterozygous for the TPMT*3C non-function allele. No patient was found to harbor both variants. In total, nine out of 60 (15%) patients tested had genotypic evidence of thiopurine intolerance, which may require dosage adjustment or alternative medication should they be started on azathioprine, mercaptopurine or thioguanine. The two newly developed assays were more efficient and showed complete concordance (60/60, 100%) compared to the Sanger sequencing results. Accurate and cost-effective genotyping assays by real-time PCR-HRM and PCR-RFLP for NUDT15 c.415C>T and TPMT*3C were successfully developed. Further studies may establish their roles in genotype-informed clinical decision-making in the prevention of morbidity and mortality due to thiopurine intolerance

Novel Tetra-Primer ARMS-PCR Assays for Thiopurine Intolerance Susceptibility Mutations NUDT15 c.415C>T and TPMT c.719A>G (TPMT*3C) in East Asians

Thiopurines are clinically useful in the management of diverse immunological and malignant conditions. Nevertheless, these purine analogues can cause lethal myelosuppression, which may be prevented by prospective testing for variants in the thiopurine S-methyltransferase (TPMT) and, in East Asians, Nudix hydrolase 15 (NUDT15) genes. Two single-tube, tetra-primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR) assays were developed to genotype the common loss-of-function variants NUDT15 c.415C>T (rs116855232) and TPMT*3C c.719A>G (rs1142345). In a group of 60 unselected patients, one and seven were found to be homozygous and heterozygous, respectively, for NUDT15 c.415C>T; one was found to be heterozygous for TPMT*3C c.719A>G. There was no non-specific amplification, and the genotypes were 100% concordant with Sanger sequencing. Limit-of-detection for both assays was below 1 ng of heterozygous template per reaction. Time- and cost-effective ARMS-PCR assays, suitable for genotyping East-Asian patients for thiopurine intolerance, were successfully developed and validated

Socialna zdržnost pri urbani prenovi: ocena želja skupnosti

Pomanjkanje prave kulture skrbi za stavbe je v večini razvitih mest pripeljalo do resnih težav zaradi propadanja mestnih predelov, in to ogroža zdravje in varnost mestnih skupnosti. Sanacija je pristop, s katerim navadno ustavimo propadanje in obnovimo propadajoča območja. Pogosto pa ima tudi negativne posledice; zmoti lahko delovanje obstoječih socialnih mrež in pretirano poveča količino odpadkov, ki nastanejo pri gradnji in rušenju zgradb. Po drugi strani je obnova stavb socialno in okolju prijaznejša izbira v primerjavi s prenovo, vendar je njen uspeh kar najbolj odvisen od sodelovanja stanovalcev. Če želimo doseči trajnostno strategijo urbane prenove, moramo najti ravnotežje med interesi različnih déležnikov za enega od obeh glavnih pristopov k prenovi. Čeprav je pomembno, da pri sprejemanju odločitev upoštevamo ekonomska in fizična vprašanja, se v tej raziskavi s strukturirano anketo preučujejo želje in preference lokalnih prebivalcev glede teh dveh možnosti. Ugotovitve prispevajo k razvoju uravnotežene in socialno trajnostne strategije urbane prenove