EnsembleSVM: A Library for Ensemble Learning Using Support Vector Machines

EnsembleSVM is a free software package containing efficient routines to perform ensemble learning with support vector machine (SVM) base models. It currently offers ensemble methods based on binary SVM models. Our implementation avoids duplicate storage and evaluation of support vectors which are shared between constituent models. Experimental results show that using ensemble approaches can drastically reduce training complexity while maintaining high predictive accuracy. The EnsembleSVM software package is freely available online at http://esat.kuleuven.be/stadius/ensemblesvm.Comment: 5 pages, 1 tabl

Influence of sow dietary polyunsaturated fatty acid source on the immunoglobulin profile of piglets

To examine the effect of different n-3 polyunsaturated fatty acid (PUFA) sources in sow diets on piglets’ immunoglobulin (Ig) profile, two groups of twelve sows each were fed different diets from day 45 of pregnancy and during lactation on two commercial farms. On farm I, a palm oil diet (25 g/kg; PALM) and a linseed oil containing diet (20 g/kg; LIN) were fed. On farm II, the same PALM diet and a fish oil containing diet (20 g/kg; FISH) were fed. All diets contained equal amounts of C18:2n-6 (13 g/kg). One day before parturition, blood (for serum) was taken and shortly after parturition, colostrum was taken from the sows (not from sows on farm I) for determination of Ig levels. On day 5 post partum and the day before weaning, blood (for serum) was taken from 4 piglets of six sows per group (24 piglets in total per group; for 5-d old piglets on farm II, only 6 piglets of the FISH group were sampled). In all samples total IgG, IgA, IgM concentration and specific F4-IgG, -IgA and -IgM titer (Log2 titer) against E. coli were determined. On farm I, the sows of the LIN group showed a trend towards lower IgG titers compared to the PALM group around farrowing (P<0.1). On farm II, the sows on the FISH diet showed a significantly (P<0.05) lower F4-IgG titer compared to the sows fed PALM. The colostrum samples on farm II showed no differences between both groups. On farm I, the 5-d old piglets from the LIN group had significantly higher IgA and IgM concentrations and higher F4-IgA and F4-IgM titers (P<0.05). F4-IgA and F4-IgG titers were also significantly higher at weaning in the LIN group compared to the PALM group. On farm II, the piglets of the FISH group had a significantly higher IgG concentration and F4-IgA titer (P<0.05) and a trend towards a higher IgM concentration (P<0.1) around weaning compared to the PALM group. It seems that fish oil in the maternal diet increases total IgG concentration, while linseed oil reduces total IgG and increases total IgA compared to a palm fat containing diet. Both fish and linseed oil seem to have a positive effect on total IgM concentration compared to the palm diet

γ-H2AX foci as in vivo effect biomarker in children emphasize the importance to minimize x-ray doses in paediatric CT imaging

Objectives: Investigation of DNA damage induced by CT x-rays in paediatric patients versus patient dose in a multicentre setting. Methods: From 51 paediatric patients (median age, 3.8 years) who underwent an abdomen or chest CT examination in one of the five participating radiology departments, blood samples were taken before and shortly after the examination. DNA damage was estimated by scoring gamma-H2AX foci in peripheral blood T lymphocytes. Patient-specific organ and tissue doses were calculated with a validated Monte Carlo program. Individual lifetime attributable risks (LAR) for cancer incidence and mortality were estimated according to the BEIR VII risk models. Results: Despite the low CT doses, a median increase of 0.13 gamma-H2AX foci/cell was observed. Plotting the induced gamma-H2AX foci versus blood dose indicated a low-dose hypersensitivity, supported also by an in vitro dose-response study. Differences in dose levels between radiology centres were reflected in differences in DNA damage. LAR of cancer mortality for the paediatric chest CT and abdomen CT cohort was 0.08 and 0.13% respectively. Conclusion: CT x-rays induce DNA damage in paediatric patients even at low doses and the level of DNA damage is reduced by application of more effective CT dose reduction techniques and paediatric protocols

Studie van het celdoodproces in candida albicans

Histatin 5 is an antimicrobial peptide with potent candidacidal activity present in the saliva of humans. Identification of functions involved in histatin 5-induced cell death can help to resolve the mechanism of action of histatin 5. In order to develop novel antifungal compounds, functions involved in this cell death process can be used as targets. By screening an overexpression library and profiling transcription, we identified functions involved in histatin 5-induced cell death in C. albicans. Overexpression analysis of some of these genes demonstrated their influence on cell death. Four of them are related to mitochondrial respiration or oxidative stress (POR1, CAT2, PGA3, TRX1), two are involved in nutrient sensing (GPR1, SNF31), one has an unknown function (IPF2973), one is involved in stress response (DDR48). The succeptibility of Saccharomyces cerevisiae to the antimicrobial peptide, histatin 5, was tested after pre-growth in fermentable and non-fermentable carbon sources and in the absence or presence of the uncoupler of oxidative phosphorylation CCCP. S. cerevisiae was more resistant to histatin 5 when grown on a fermentable carbon source compared to growth on a non-fermentable carbon source, indicating an important role for oxidative phosphorylation in histatin 5-induced cell death. Oxidative phosphorylation is a prerequisite for histatin 5-induced cell death in Candida albicans, this is not the case in S. cerevisiae. Incubation of CCCP-treated S. cerevisiae cells with histatin 5 still resulted in cell death. These results suggest that histatin 5-induced cell death in S. cerevisiae differs from that in C. albicans. Bax is a pro-apoptotic protein involved in the regulation of genetically programmed cell death in mammalian cells. It has been shown that heterologous expression of Bax in several yeast species also induces cell death. We investigated the effects of Bax expression in the yeast Candida albicans. Expression of BAX resulted in growth inhibition and cell death. By fusing Bax with yeGFP, the cell death-inducing effect of Bax was increased. Using this fusion protein we showed that in C. albicans Bax co-localizes with the mitochondria. Furthermore, we showed that expression of Bax in yeast causes the mitochondria to cluster in the perinuclear region

The Abbey of the Dunes (Koksijde) and Noordduinen: the environmental link restored

The Abbey of the Dunes (Ten Duinen) at Koksijde, founded in the 12th century and abandoned around 1600, forms the subject of a land use planning project realized by the Flemish Land Agency (Vlaamse Landmaatschappij). Initially the project focussed on the museum and the integration of the abbey ruins in an open-air museum. However the site presented an opportunity to involve the Noordduinen, bordering on the abbey park, in a nature restoration project. The key intention was to restore the landscape connection between the abbey and the dunes, as it was in the Middle Ages. The proposed actions consist of breaking up a road, deviation of the traffic, upgrading the abbey park and start of a nature restoration project in the Noordduinen. The main bottlenecks were deviation of the traffic, excavation and preservation of archaeological finds and intensive recreational use of the Noordduinen. Continuous consultation and deliberation with all involved authorities and with the local inhabitants of Koksijde resulted in a plan supported by the majority of the community

On the Energy Efficiency of Electric Vehicles with Multiple Motors

Electric Vehicles (EVs) with multiple motors permit to design the steady-state cornering response by imposing reference understeer characteristics according to expected vehicle handling quality targets. To this aim a direct yaw moment is generated by assigning different torque demands to the left and right vehicle sides. The reference understeer characteristic has an impact on the drivetrain input power as well. In parallel, a Control Allocation (CA) strategy can be employed to achieve an energy-efficient wheel torque distribution generating the reference yaw moment and wheel torque. To the knowledge of the authors, for the first time this paper experimentally compares and critically analyses the potential energy efficiency benefits achievable through the appropriate set-up of the reference understeer characteristics and wheel torque CA. Interestingly, the experiments on a four wheel-drive EV demonstrator show that higher energy savings can be obtained through the appropriate tuning of the reference cornering response rather than with an energy efficient CA

Module networks revisited: computational assessment and prioritization of model predictions

The solution of high-dimensional inference and prediction problems in computational biology is almost always a compromise between mathematical theory and practical constraints such as limited computational resources. As time progresses, computational power increases but well-established inference methods often remain locked in their initial suboptimal solution. We revisit the approach of Segal et al. (2003) to infer regulatory modules and their condition-specific regulators from gene expression data. In contrast to their direct optimization-based solution we use a more representative centroid-like solution extracted from an ensemble of possible statistical models to explain the data. The ensemble method automatically selects a subset of most informative genes and builds a quantitatively better model for them. Genes which cluster together in the majority of models produce functionally more coherent modules. Regulators which are consistently assigned to a module are more often supported by literature, but a single model always contains many regulator assignments not supported by the ensemble. Reliably detecting condition-specific or combinatorial regulation is particularly hard in a single optimum but can be achieved using ensemble averaging.Comment: 8 pages REVTeX, 6 figure