Lightweight EDF scheduling with deadline inheritance

EDFI is a lightweight real-time scheduling protocol that combines EDF with deadline inheritance over shared resources. We will show that EDFI is flexible during a tasks admission control, efficient with scheduling and dispatching, and straightforward in feasibility analysis. The application programmer only needs to specify a tasks timing constraints (deadline, period, runtime) and resource needs, after which EDFI can execute admission control, scheduling, dispatching and resource synchronisation automatically. EDFI avoids gratuitous task switching and its programming overhead as well as runtime overhead is very low, which makes it ideal for lightweight and featherweight kernels. We will illustrate the elegance of the underlying theory and we will shortly discuss the implementation of EDFI in three different operating systems

Practices in timetabling in higher education institutions:A systematic review

The study of differences between timetabling research presented in conferences like PATAT or published in Annals of OR and commercial timetabling software used in Higher Education Institutions (HEIs) is essential for the discussion about innovation in both higher education and in commerce. In the field of planning and scheduling, a lot of developments are made and it is important to recognise that these developments are of influence on HEIs through their use of timetabling software. A main objective of the work presented here is to provide up-to-date information about timetabling in HEIs and see to what extent they adopt and implement timetabling developments. This is crucial because of budgets of institutions being strictly limited and remaining resources like rooms having to be shared more and more. Developments in HEIs have caused planning processes in higher education to deal with more limitations than ever, while at the same time the demand towards flexibility and availability is increasing. This paper gives the results of a systematic literature review in which differences and similarities in theory and practice of timetabling in higher education are described and discussed. We looked at state-of-the-art timetabling research for HEIs, at innovations in the field of timetabling and at changing requirements in Higher Education. The aim of this paper is to motivate the discussion about both the differences and similarities and bring timetabling application development closer to educational requirements

RNAseq Profiling of Leukocyte Populations in Zebrafish Larvae Reveals a cxcl11 Chemokine Gene as a Marker of Macrophage Polarization During Mycobacterial Infection

Macrophages are phagocytic cells from the innate immune system, which forms the first line of host defense against invading pathogens. These highly dynamic immune cells can adopt specific functional phenotypes, with the pro-inflammatory M1 and anti-inflammatory M2 polarization states as the two extremes. Recently, the process of macrophage polarization during inflammation has been visualized by real time imaging in larvae of the zebrafish. This model organism has also become widely used to study macrophage responses to microbial pathogens. To support the increasing use of zebrafish in macrophage biology, we set out to determine the complete transcriptome of zebrafish larval macrophages. We studied the specificity of the macrophage signature compared with other larval immune cells and the macrophage-specific expression changes upon infection. We made use of the well-established mpeg1, mpx, and lck fluorescent reporter lines to sort and sequence the transcriptome of larval macrophages, neutrophils, and lymphoid progenitor cells, respectively. Our results provide a complete dataset of genes expressed in these different immune cell types and highlight their similarities and differences. Major differences between the macrophage and neutrophil signatures were found within the families of proteinases. Furthermore, expression of genes involved in antigen presentation and processing was specifically detected in macrophages, while lymphoid progenitors showed expression of genes involved in macrophage activation. Comparison with datasets of in vitro polarized human macrophages revealed that zebrafish macrophages express a strongly homologous gene set, comprising both M1 and M2 markers. Furthermore, transcriptome analysis of low numbers of macrophages infected by the intracellular pathogen Mycobacterium marinum revealed that infected macrophages change their transcriptomic response by downregulation of M2-associated genes and overexpression of specific M1-associated genes. Among the infection-induced genes, a homolog of the human CXCL11 chemokine gene, cxcl11aa, stood out as the most strongly overexpressed M1 marker. Upregulation of cxcl11aa in Mycobacterium-infected macrophages was found to require the function of Myd88, a critical adaptor molecule in the Toll-like and interleukin 1 receptor pathways that are central to pathogen recognition and activation of the innate immune response. Altogether, our data provide a valuable data mining resource to support infection and inflammation research in the zebrafish model

The Effect of Stress and TiC Coated Balls on Lubricant Lifetimes Using a Vacuum Ball-on-Plate Rolling Contact Tribometer

A vacuum ball-on-plate rolling contact tribometer was used to determine the relative lifetimes of a perfluoropolyether (Krytox 143 AC) on 440C stainless steel. The effect of mean Hertzian stresses (0.75, 1.0, 1.5 and 2.0 GPa) and the use of TiC coated balls on lubricant lifetime was studied. Other conditions included: approximately 100 rpm, approximately 50 micrograms of lubricant, an initial vacuum level of less than 1.0 x 1O(exp -8) Torr, and room temperature (approximately 23 C). increasing the mean Hertzian stress from 0.75 to 2.0 GPa results in an exponential decrease in lubricant lifetime for both material combinations. However. substituting a TiC ball for the 440C ball quadrupled lifetime at low stress levels (0.75 and 1.0 GPa) and doubled life at higher stresses (1.5 and 2.0 GPa). The reduced reactivity of the TiC surface with the PFPE lubricant is considered to be the reason for this enhancement. Decreasing lifetime with increasing stress levels correlated well with energy dissipation calculations

Effect of α+-thalassaemia on episodes of fever due to malaria and other causes: a community-based cohort study in Tanzania

It is controversial to what degree α(+)-thalassaemia protects against episodes of uncomplicated malaria and febrile disease due to infections other than Plasmodium. In Tanzania, in children aged 6-60 months and height-for-age z-score < -1.5 SD (n = 612), rates of fevers due to malaria and other causes were compared between those with heterozygous or homozygotes α(+)-thalassaemia and those with a normal genotype, using Cox regression models that accounted for multiple events per child. The overall incidence of malaria was 3.0/child-year (1, 572/526 child-years); no differences were found in malaria rates between genotypes (hazard ratios, 95% CI: 0.93, 0.82-1.06 and 0.91, 0.73-1.14 for heterozygotes and homozygotes respectively, adjusted for baseline factors that were predictive for outcome). However, this association strongly depended on age: among children aged 6-17 months, those with α(+)-thalassaemia experienced episodes more frequently than those with a normal genotype (1.30, 1.02-1.65 and 1.15, 0.80-1.65 for heterozygotes and homozygotes respectively), whereas among their peers aged 18-60 months, α(+)-thalassaemia protected against malaria (0.80, 0.68-0.95 and 0.78, 0.60-1.03; p-value for interaction 0.001 and 0.10 for hetero- and homozygotes respectively). No effect was observed on non-malarial febrile episodes. In this population, the association between α(+)-thalassaemia and malaria depends on age. Our data suggest that protection by α(+)-thalassaemia is conferred by more efficient acquisition of malaria-specific immunity

Spontaneous rescue from cystic fibrosis in a mouse model

BACKGROUND: From the original Cftr(TgH(neoim)Hgu )mutant mouse model with a divergent genetic background (129P2, C57BL/6, MF1) we have generated two inbred Cftr(TgH(neoim)Hgu )mutant strains named CF/1-Cftr(TgH(neoim)Hgu )and CF/3-Cftr(TgH(neoim)Hgu), which are fertile and show normal growth and lifespan. Initial genome wide scan analysis with microsatellite markers indicated that the two inbred strains differed on the genetic level. In order to further investigate whether these genetic differences have an impact on the disease phenotype of cystic fibrosis we characterised the phenotype of the two inbred strains. RESULTS: Reduced amounts, compared to wild type control animals, of correctly spliced Cftr mRNA were detected in the nasal epithelia, lungs and the intestine of both inbred Cftr(TgH(neoim)Hgu )strains, with higher residual amount observed for CF/1-Cftr(TgH(neoim)Hgu )than CF/3-Cftr(TgH(neoim)Hgu )for every investigated tissue. Accordingly the amounts of wild type Cftr protein in the intestine were 9% for CF/1-Cftr(TgH(neoim)Hgu )and 4% for CF/3-Cftr(TgH(neoim)Hgu). Unlike the apparent strain and/or tissue specific regulation of Cftr mRNA splicing, short circuit current measurements in the respiratory and intestinal epithelium revealed that both strains have ameliorated the basic defect of cystic fibrosis with a presentation of a normal electrophysiology in both tissues. CONCLUSION: Unlike the outbred Cftr(TgH(neoim)Hgu )insertional mouse model, which displayed the electrophysiological defect in the gastrointestinal and respiratory tracts characteristic of cystic fibrosis, both inbred Cftr(TgH(neoim)Hgu )strains have ameliorated the electrophysiological defect. On the basis of these findings both CF/1-Cftr(TgH(neoim)Hgu )and CF/3-Cftr(TgH(neoim)Hgu )offer an excellent model whereby determination of the minimal levels of protein required for the restoration of the basic defect of cystic fibrosis can be studied, along with the modulating factors which may affect this outcome

MLPAinter for MLPA interpretation: An integrated approach for the analysis, visualisation and data management of Multiplex Ligation-dependent Probe Amplification

Background: Multiplex Ligation-Dependent Probe Amplification (MLPA) is an application that can be used for the detection of multiple chromosomal aberrations in a single experiment. In one reaction, up to 50 different genomic sequences can be analysed. For a reliable work-flow, tools are needed for administrative support, data management, normalisation, visualisation, reporting and interpretation.Results: Here, we developed a data management system, MLPAInter for MLPA interpretation, that is windows executable and has a stand-alone database for monitoring and interpreting the MLPA data stream that is generated from the experimental setup to analysis, quality control and visualisation. A statistical approach is applied for the normalisation and analysis of large series of MLPA traces, making use of multiple control samples and internal controls.Conclusions: MLPAinter visualises MLPA data in plots with information about sample replicates, normalisation settings, and sample characteristics. This integrated approach helps in the automated handling of large series of MLPA data and guarantees a quick and streamlined dataflow from the beginning of an experiment to an authorised report