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Every five years, a group of the leading database researchers meet to reflect on their community's impact on the computing industry as well as examine current research challenges.

We propose a simple definition of an explanation for the outcome of a classifier based on concepts from causality. We compare it with previously proposed notions of explanation, and study their complexity. We conduct an experimental evaluation with two real datasets from the financial domain.

BACKGROUND: Molecular genetic testing is commonly used to confirm clinical diagnoses of inherited urea cycle disorders (UCDs); however, conventional mutation screenings encompassing only the coding regions of genes may not detect disease-causing mutations occurring in regulatory elements and introns. Microarray-based target enrichment and next-generation sequencing now allow more-comprehensive genetic screening. We applied this approach to UCDs and combined it with the use of DNA bar codes for more cost-effective, parallel analyses of multiple samples. METHODS: We used sectored 2240-feature medium-density oligonucleotide arrays to capture and enrich a 199-kb genomic target encompassing the complete genomic regions of 3 urea cycle genes, OTC (ornithine carbamoyltransferase), CPS1 (carbamoyl-phosphate synthetase 1, mitochondrial), and NAGS (N-acetylglutamate synthase). We used the Genome Sequencer FLX System (454 Life Sciences) to jointly analyze 4 samples individually tagged with a 6-bp DNA bar code and compared the results with those for an individually sequenced sample. RESULTS: Using a low tiling density of only 1 probe per 91 bp, we obtained strong enrichment of the targeted loci to achieve ≥90% coverage with up to 64% of the sequences covered at a sequencing depth ≥10-fold. We observed a very homogeneous sequence representation of the bar-coded samples, which yielded a >30% increase in the sequence data generated per sample, compared with an individually processed sample. Heterozygous and homozygous disease-associated mutations were correctly detected in all samples. CONCLUSIONS: The use of DNA bar codes and the use of sectored oligonucleotide arrays for target enrichment enable parallel, large-scale analysis of complete genomic regions for multiple genes of a disease pathway and for multiple samples simultaneously. This approach thus may provide an efficient tool for comprehensive diagnostic screening of mutations.

A trickling filter pilot plant was operated to biologically degrade spent phenol paint stripper from building 507 at the Hill AFB Air Logistic Center in Ogden, Utah. The parameters studied were temperature, pH, diammonium phosphate concentration, air flow, influent flow rate, and phenol concentration. Also, series flow, recirculation, and a flooded reactor bed were tested. The pilot plant was operated successfully over a broad range of parameters and phenol removal was demonstrated at concentrations up to 2100 ppm of phenol. The microorganisms degraded phenol at a constant rate related to phenol concentration, and they exhibited physiological stability to the parameters tested. A respirometer test apparatus was used to screen the temperature, pH, and diammonium phosphate and phenol concentrations. The effects of the concentration of chromium and cadmium and those of mixed phenols on the respiration rate were also evaluated with the respirometer. Keywords: Solvent degradation; Waste minimization; Phenolic wastewater.