Improved post-processing for GMM based adaptive background modeling

In this paper, we propose a new post-processing method for Gaussian mixture model (GMM) based adaptive background modeling which was proposed by Stauffer and Grimson. This is a ubiquitous and successful background modeling method. A drawback of this method is that it assumes independence of pixels and relies solely on the difference between current pixel value and its past values. This causes some errors within the foreground region and results in fragmentation of foreground objects detected. Our method uses relaxed-thresholding and adds foreground edge information in close proximity of detected foreground blobs. The close proximity is obtained as the union of convex hulls of close-by regions which we call the hysteresis region. Our results show that we can achieve increased recall rate with the proposed method without much decreasing the precision of the conventional method

Antiprotozoal activity and cytotoxicity of Lycopodium clavatum and Lycopodium complanatum subsp. chamaecyparissus extracts

Objective: the aim of this study is to investigate the in vitro antioxidant activity, the total phenol and flavonoid content and the possible protective effects of commercial propolis on gentamicin-induced nephrotoxicity in rabbits. Methods: the in vitro antioxidant activity was measured by ferric reducing antioxidant power assay and cupric reducing antioxidant capacity assay, the total phenols content was measured by folin–ciocalteau assay, the flavonoids content by the alcl3 colorimetric method and the renoprotective effects of propolis methanol extract was evaluated in a rabbit model of gentamicin-induced nephrotoxicity. The protective effects of propolis on gentamicin-induced nephrotoxicity in rabbits were evaluated through biochemical parameter (measuring serum urea and creatinine) and histopathological alterations in kidneys Results: methanol extract of propolis showed a strong antioxidant activity, which is attributed to its high phenolic and flavonoid contents. Oral administration of propolis extract to rabbits at a dose of 1 mg/kg body weight significantly protected against histopathological and biochemical alterations induced by gentamicin. Conclusion: the present study demonstrated that commercial propolis is strong antioxidant and is effective for the prevention of gentamicin-induced renal damage in rabbit

Self-Supervised Learning with an Information Maximization Criterion

Self-supervised learning allows AI systems to learn effective representations from large amounts of data using tasks that do not require costly labeling. Mode collapse, i.e., the model producing identical representations for all inputs, is a central problem to many self-supervised learning approaches, making self-supervised tasks, such as matching distorted variants of the inputs, ineffective. In this article, we argue that a straightforward application of information maximization among alternative latent representations of the same input naturally solves the collapse problem and achieves competitive empirical results. We propose a self-supervised learning method, CorInfoMax, that uses a second-order statistics-based mutual information measure that reflects the level of correlation among its arguments. Maximizing this correlative information measure between alternative representations of the same input serves two purposes: (1) it avoids the collapse problem by generating feature vectors with non-degenerate covariances; (2) it establishes relevance among alternative representations by increasing the linear dependence among them. An approximation of the proposed information maximization objective simplifies to a Euclidean distance-based objective function regularized by the log-determinant of the feature covariance matrix. The regularization term acts as a natural barrier against feature space degeneracy. Consequently, beyond avoiding complete output collapse to a single point, the proposed approach also prevents dimensional collapse by encouraging the spread of information across the whole feature space. Numerical experiments demonstrate that CorInfoMax achieves better or competitive performance results relative to the state-of-the-art SSL approaches

Exploring Sources of Engineering Teaching Self-Efficacy for Pre-Service Elementary Teachers

Background: The Next Generation Science Standards (2013) put a special emphasis on engineering for K-12 science education. However, a significant number of elementary teachers still feel unprepared to integrate engineering into their science programs. It is, therefore, incumbent upon science educators to update their elementary science methods courses to accommodate engineering especially in the states which adopted the NGSS. In this study, we taught an engineering unit in an elementary science teaching methods course to examine what instructional components and learning experiences provided in the engineering unit enhance teachers’ engineering teaching self-efficacy beliefs. Our research questions addressed to what extent the engineering education intervention improved pre-service teachers’ engineering teaching efficacy beliefs and what instructional components and learning experiences served as sources of self-efficacy contributing to the improvement of pre-service elementary teachers’ engineering teaching efficacy beliefs. We also explored how pre-service teachers viewed the relative importance of the sources of teaching efficacy stemming from the engineering unit. Results: The participants comprised 84 pre-service teachers enrolled in an elementary education program at a public university in the Southwestern United States. Data obtained from the Engineering Teaching Efficacy Beliefs Instrument (ETEBI) indicated that the pre-service teachers’ personal teaching efficacy beliefs significantly improved after the engineering intervention; however, the engineering intervention had a small impact on teachers’ engineering teaching outcome expectancy beliefs. Written reflections used to explore the sources of engineering teaching efficacy and the relative importance of each source showed that cognitive content mastery and cognitive pedagogical mastery were the major sources of engineering teaching self-efficacy among the pre-service elementary teachers. Conclusion: Our study illustrated that integrating engineering design activities with explicit-reflective instruction on the nature of engineering concepts could enhance pre-service teachers’ personal engineering teaching efficacy beliefs even though a relatively small impact was observed in their engineering teaching outcome expectancy beliefs. Also, the study indicated cognitive content mastery and cognitive pedagogical mastery were the most important sources of engineering teaching efficacy. Therefore, the study suggests that it is vital to integrate a variety of mastery and vicarious experiences in methods courses to support the development of teachers’ engineering teaching efficacy beliefs. Besides, the current study could provide an example for integrating engineering education in methods courses

MITF-MIR211 axis is a novel autophagy amplifier system during cellular stress

Macroautophagy (autophagy) is an evolutionarily conserved recycling and stress response mechanism. Active at basal levels in eukaryotes, autophagy is upregulated under stress providing cells with building blocks such as amino acids. A lysosome-integrated sensor system composed of RRAG GTPases and MTOR complex 1 (MTORC1) regulates lysosome biogenesis and autophagy in response to amino acid availability. Stress-mediated inhibition of MTORC1 results in the dephosphorylation and nuclear translocation of the TFE/MITF family of transcriptional factors, and triggers an autophagy- and lysosomal-related gene transcription program. The role of family members TFEB and TFE3 have been studied in detail, but the importance of MITF proteins in autophagy regulation is not clear so far. Here we introduce for the first time a specific role for MITF in autophagy control that involves upregulation of MIR211. We show that, under stress conditions including starvation and MTOR inhibition, a MITF-MIR211 axis constitutes a novel feed-forward loop that controls autophagic activity in cells. Direct targeting of the MTORC2 component RICTOR by MIR211 led to the inhibition of the MTORC1 pathway, further stimulating MITF translocation to the nucleus and completing an autophagy amplification loop. In line with a ubiquitous function, MITF and MIR211 were co-expressed in all tested cell lines and human tissues, and the effects on autophagy were observed in a cell-type independent manner. Thus, our study provides direct evidence that MITF has rate-limiting and specific functions in autophagy regulation. Collectively, the MITF-MIR211 axis constitutes a novel and universal autophagy amplification system that sustains autophagic activity under stress conditions.No sponso

The essentials of marine biotechnology.

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better health and well-being, new biomedicines, natural cosmeceuticals, environmental conservation, and sustainable energy sources. These societal needs stimulated the interest of researchers on the diverse and underexplored marine environments as promising and sustainable sources of biomolecules and biomass, and they are addressed by the emerging field of marine (blue) biotechnology. Blue biotechnology provides opportunities for a wide range of initiatives of commercial interest for the pharmaceutical, biomedical, cosmetic, nutraceutical, food, feed, agricultural, and related industries. This article synthesizes the essence, opportunities, responsibilities, and challenges encountered in marine biotechnology and outlines the attainment and valorization of directly derived or bio-inspired products from marine organisms. First, the concept of bioeconomy is introduced. Then, the diversity of marine bioresources including an overview of the most prominent marine organisms and their potential for biotechnological uses are described. This is followed by introducing methodologies for exploration of these resources and the main use case scenarios in energy, food and feed, agronomy, bioremediation and climate change, cosmeceuticals, bio-inspired materials, healthcare, and well-being sectors. The key aspects in the fields of legislation and funding are provided, with the emphasis on the importance of communication and stakeholder engagement at all levels of biotechnology development. Finally, vital overarching concepts, such as the quadruple helix and Responsible Research and Innovation principle are highlighted as important to follow within the marine biotechnology field. The authors of this review are collaborating under the European Commission-funded Cooperation in Science and Technology (COST) Action Ocean4Biotech – European transdisciplinary networking platform for marine biotechnology and focus the study on the European state of affairs

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Compressed representation of a partially defined integer function over multiple arguments

In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV

Results are presented from a search for physics beyond the standard model based on events with large missing transverse energy, at least three jets, and at least one, two, or three b-quark jets. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS detector at the LHC in 2011. The integrated luminosity of the sample is 4.98 inverse femtobarns. The observed number of events is found to be consistent with the standard model expectation, which is evaluated using control samples in the data. The results are used to constrain cross sections for the production of supersymmetric particles decaying to b-quark-enriched final states in the context of simplified model spectra.Comment: Submitted to Physical Review