Integration of Exploration and Search: A Case Study of the M3 Model

International audienceEffective support for multimedia analytics applications requires exploration and search to be integrated seamlessly into a single interaction model. Media metadata can be seen as defining a multidimensional media space, casting multimedia analytics tasks as exploration, manipulation and augmentation of that space. We present an initial case study of integrating exploration and search within this multidimensional media space. We extend the M3 model, initially proposed as a pure exploration tool, and show that it can be elegantly extended to allow searching within an exploration context and exploring within a search context. We then evaluate the suitability of relational database management systems, as representatives of today’s data management technologies, for implementing the extended M3 model. Based on our results, we finally propose some research directions for scalability of multimedia analytics

Using Structural Equation Modeling to Investigate Students' Career Awareness in Science

One of the goals of education is to enable young adults to become critical evaluators of their career pursuits. Recognizing this, the objectives of this study were to: (1) develop a model of the relationships among some of the variables underlying students’ career awareness in science, and (2) evaluate the model using PISA 2006 data for the United States and Canada. Results revealed that for both the USA and Canada, students’ self–efficacy in science had the largest direct effect on their science proficiency. Additionally, how students perceived their science school subjects in relation to career and job prospects contributed the most to their career awareness. Findings from this study have a potential to inform educational policies and suggest mechanisms to raise students’ career awareness and motivation to pursue careers in science

Conservation versus parallel gains in intron evolution

Orthologous genes from distant eukaryotic species, e.g. animals and plants, share up to 25–30% intron positions. However, the relative contributions of evolutionary conservation and parallel gain of new introns into this pattern remain unknown. Here, the extent of independent insertion of introns in the same sites (parallel gain) in orthologous genes from phylogenetically distant eukaryotes is assessed within the framework of the protosplice site model. It is shown that protosplice sites are no more conserved during evolution of eukaryotic gene sequences than random sites. Simulation of intron insertion into protosplice sites with the observed protosplice site frequencies and intron densities shows that parallel gain can account but for a small fraction (5–10%) of shared intron positions in distantly related species. Thus, the presence of numerous introns in the same positions in orthologous genes from distant eukaryotes, such as animals, fungi and plants, appears to reflect mostly bona fide evolutionary conservation

Mutational hotspots in the TP53 gene and, possibly, other tumor suppressors evolve by positive selection

BACKGROUND: The mutation spectra of the TP53 gene and other tumor suppressors contain multiple hotspots, i.e., sites of non-random, frequent mutation in tumors and/or the germline. The origin of the hotspots remains unclear, the general view being that they represent highly mutable nucleotide contexts which likely reflect effects of different endogenous and exogenous factors shaping the mutation process in specific tissues. The origin of hotspots is of major importance because it has been suggested that mutable contexts could be used to infer mechanisms of mutagenesis contributing to tumorigenesis. RESULTS: Here we apply three independent tests, accounting for non-uniform base compositions in synonymous and non-synonymous sites, to test whether the hotspots emerge via selection or due to mutational bias. All three tests consistently indicate that the hotspots in the TP53 gene evolve, primarily, via positive selection. The results were robust to the elimination of the highly mutable CpG dinucleotides. By contrast, only one, the least conservative test reveals the signature of positive selection in BRCA1, BRCA2, and p16. Elucidation of the origin of the hotspots in these genes requires more data on somatic mutations in tumors. CONCLUSION: The results of this analysis seem to indicate that positive selection for gain-of-function in tumor suppressor genes is an important aspect of tumorigenesis, blurring the distinction between tumor suppressors and oncogenes. REVIEWERS: This article was reviewed by Sandor Pongor, Christopher Lee and Mikhail Blagosklonny

Evolutionary conservation suggests a regulatory function of AUG triplets in 50 -UTRs of eukaryotic genes

By comparing sequences of human, mouse and rat orthologous genes, we show that in 50 -untranslated regions (50 -UTRs) of mammalian cDNAs but not in 30 - UTRs or coding sequences, AUG is conserved to a significantly greater extent than any of the other 63 nt triplets. This effect is likely to reflect, primarily, bona fide evolutionary conservation, rather than cDNA annotation artifacts, because the excess of conserved upstream AUGs (uAUGs) is seen in 50 -UTRs containing stop codons in-frame with the start AUG and many of the conserved AUGs are found in different frames, consistent with the location in authentic non-coding sequences. Altogether, conserved uAUGs are present in at least 20–30% of mammalian genes. Qualitatively similar results were obtained by comparison of orthologous genes from different species of the yeast genus Saccharomyces. Together with the observation that mammalian and yeast 50 -UTRs are significantly depleted in overall AUG content, these findings suggest that AUG triplets in 50 -UTRs are subject to the pressure of purifying selection in two opposite directions: the uAUGs that have no specific function tend to be deleterious and get eliminated during evolution, whereas those uAUGs thatdoserveafunctionareconserved.Mostprobably, the principal role of the conserved uAUGs is attenuation of translation at the initiation stage, which is often additionally regulated by alternative splicing in the mammalian 50 -UTRs. Consistent with this hypothesis, we found that open reading frames starting from conserved uAUGs are significantly shorter than those starting from non-conserved uAUGs, possibly, owing to selection for optimization of the level of attenuation

Evolutionary conservation suggests a regulatory function of AUG triplets in 5′-UTRs of eukaryotic genes

By comparing sequences of human, mouse and rat orthologous genes, we show that in 5′-untranslated regions (5′-UTRs) of mammalian cDNAs but not in 3′-UTRs or coding sequences, AUG is conserved to a significantly greater extent than any of the other 63 nt triplets. This effect is likely to reflect, primarily, bona fide evolutionary conservation, rather than cDNA annotation artifacts, because the excess of conserved upstream AUGs (uAUGs) is seen in 5′-UTRs containing stop codons in-frame with the start AUG and many of the conserved AUGs are found in different frames, consistent with the location in authentic non-coding sequences. Altogether, conserved uAUGs are present in at least 20–30% of mammalian genes. Qualitatively similar results were obtained by comparison of orthologous genes from different species of the yeast genus Saccharomyces. Together with the observation that mammalian and yeast 5′-UTRs are significantly depleted in overall AUG content, these findings suggest that AUG triplets in 5′-UTRs are subject to the pressure of purifying selection in two opposite directions: the uAUGs that have no specific function tend to be deleterious and get eliminated during evolution, whereas those uAUGs that do serve a function are conserved. Most probably, the principal role of the conserved uAUGs is attenuation of translation at the initiation stage, which is often additionally regulated by alternative splicing in the mammalian 5′-UTRs. Consistent with this hypothesis, we found that open reading frames starting from conserved uAUGs are significantly shorter than those starting from non-conserved uAUGs, possibly, owing to selection for optimization of the level of attenuation

Meta-Tracker: Fast and Robust Online Adaptation for Visual Object Trackers

This paper improves state-of-the-art visual object trackers that use online adaptation. Our core contribution is an offline meta-learning-based method to adjust the initial deep networks used in online adaptation-based tracking. The meta learning is driven by the goal of deep networks that can quickly be adapted to robustly model a particular target in future frames. Ideally the resulting models focus on features that are useful for future frames, and avoid overfitting to background clutter, small parts of the target, or noise. By enforcing a small number of update iterations during meta-learning, the resulting networks train significantly faster. We demonstrate this approach on top of the high performance tracking approaches: tracking-by-detection based MDNet and the correlation based CREST. Experimental results on standard benchmarks, OTB2015 and VOT2016, show that our meta-learned versions of both trackers improve speed, accuracy, and robustness.Comment: Code: https://github.com/silverbottlep/meta_tracker

Using microorganisms for cleaning oil-contaminated concrete

Revealed that the distribution of spots on the surface of the concrete depends on its density and structure, and the penetration of oil into the concrete occurs through micro- and nano-pores and cracks of the further spread of spots along the pathways. It was found that the use of hydrocarbon-oxidizing microorganisms strains as Micrococcus luteus IS16, M. varians IS41, micromycetes: Aspergillus sp., Penicillium sp., Alternaria sp., thiobacteria Acidithiobacillus ferrooxidans Ach1, A. ferrooxidans Ach2 promising for biological treatment of oil-contaminated concrete. Create optimal conditions for maintaining the activity of microorganisms: 55,0 ± 15,0% moisture, nutrients, temperature 38,0 ± 2,00C, trace elements, optimize the biodegradation of petroleum hydrocarbons