Maximum Distance Separable Convolutional Codes

A maximum distance separable (MDS) block code is a linear code whose distance is maximal among all linear block codes of rate k/n. It is well known that MDS block codes do exist if the field size is more than n. In this paper we generalize this concept to the class of convolutional codes of a fixed rate k/n and a fixed code degree δ. In order to achieve this result we will introduce a natural upper bound for the free distance generalizing the Singleton bound. The main result of the paper shows that this upper bound can be achieved in all cases if one allows sufficiently many field elements. Received: December 10, 1998; revised version: May 14, 1999     

Macrophage-like Cells Are Responsive to Titania Nanotube Intertube Spacing—An In Vitro Study

With the introduction of a new interdisciplinary field, osteoimmunology, today, it is well acknowledged that biomaterial-induced inflammation is modulated by immune cells, primarily macrophages, and can be controlled by nanotopographical cues. Recent studies have investigated the effect of surface properties in modulating the immune reaction, and literature data indicate that various surface cues can dictate both the immune response and bone tissue repair. In this context, the purpose of the present study was to investigate the effects of titanium dioxide nanotube (TNT) interspacing on the response of the macrophage-like cell line RAW 264.7. The cells were maintained in contact with the surfaces of flat titanium (Ti) and anodic TNTs with an intertube spacing of 20 nm (TNT20) and 80 nm (TNT80), under standard or pro-inflammatory conditions. The results revealed that nanotube interspacing can influence macrophage response in terms of cell survival and proliferation, cellular morphology and polarization, cytokine/chemokine expression, and foreign body reaction. While the nanostructured topography did not tune the macrophages’ differentiation into osteoclasts, this behavior was significantly reduced as compared to flat Ti surface. Overall, this study provides a new insight into how nanotubes’ morphological features, particularly intertube spacing, could affect macrophage behavior.     

Next-Generation Sequencing of Local Romanian Tomato Varieties and Bioinformatics Analysis of the Ve Locus

Genetic variability is extremely important, not only for the species’ adaptation to environmental challenges, but also for the creation of novel varieties through plant breeding. Tomato is an important vegetable crop, as well as a model species in numerous genomic studies. Its genome was fully sequenced in 2012 for the ‘Heinz 1706’ variety, and since then, resequencing efforts have revealed genetic variability data that can be used for multiple purposes, including triggering mechanisms of biotic and abiotic stress resistance. The present study focused on the analysis of the genome variation for eight Romanian local tomato varieties using next-generation sequencing technique, and as a case study, the sequence analysis of the Ve1 and Ve2 loci, to determine which genotypes might be good candidates for future breeding of tomato varieties resistant to Verticillium species. The analysis of the Ve locus identified several genotypes that could be donors of the Ve1 gene conferring resistance to Verticillium race 1. Sequencing for the first time Romanian genotypes enriched the existing data on various world tomato genetic resources, but also opened the way for the molecular breeding in Romania. Plant breeders can use these data to create novel tomato varieties adapted to the ever-changing environment.     

Targeting Cell Death Mechanism Specifically in Triple Negative Breast Cancer Cell Lines

Triple negative breast cancer (TNBC) is currently associated with a lack of treatment options. Arsenic derivatives have shown antitumoral activity both in vitro and in vivo; however, their mode of action is not completely understood. In this work we evaluate the response to arsenate of the double positive MCF-7 breast cancer cell line as well as of two different TNBC cell lines, Hs578T and MDA-MB-231. Multimodal experiments were conducted to this end, using functional assays and microarrays. Arsenate was found to induce cytoskeletal alteration, autophagy and apoptosis in TNBC cells, and moderate effects in MCF-7 cells. Gene expression analysis showed that the TNBC cell lines’ response to arsenate was more prominent in the G2M checkpoint, autophagy and apoptosis compared to the Human Mammary Epithelial Cells (HMEC) and MCF-7 cell lines. We confirmed the downregulation of anti-apoptotic genes (MCL1, BCL2, TGFβ1 and CCND1) by qRT-PCR, and on the protein level, for TGFβ2, by ELISA. Insight into the mode of action of arsenate in TNBC cell lines it is provided, and we concluded that TNBC and non-TNBC cell lines reacted differently to arsenate treatment in this particular experimental setup. We suggest the future research of arsenate as a treatment strategy against TNBC.     

Esterolytic and lipolytic activities of lactic acid bacteria isolated from ewe's milk and cheese

In the present work, we report on the esterase and lipase activities of lactic acid bacteria representing the genera Lactococcus, Leuconostoc, Lactobacillus, and Enterococcus isolated from ewe's milk and cheeses. Esterase activity was studied using alpha- and beta-naphthyl derivatives of 2 to 12 carbon atoms and postelectrophoretic detection. The lactic acid bacteria evaluated had intracellular esterase activities, which preferentially degraded the alpha- and beta-naphthyl derivatives of 2 to 6 carbon atoms. By studying postelectrophoretic patterns, it was found that some strains presented more than one esterase. Lactobacillus plantarum O236 showed four enzymes that hydrolyze carboxyl ester linkages with different specificity. Lipase activity was studied in intracellular and extracellular fractions using tributyrin, tricaprylin, triolein, and milk fat as substrates. The intracellular and extracellular fractions of Leuconostoc mesenteroides O257, Lactobacillus plantarum O236, and Lactobacillus acidophilus O177 were able to hydrolyze tributyrin. L. plantarum O186, L. acidophilus O252, Enterococcus faecium O174 and O426, and Enterococcus faecalis Ov409 showed lipase activity associated with the intracellular fraction on tributyrin. Lactococcus lactis O233, L. plantarum O155, and Lactobacillus casei O190 did not hydrolyze triglycerides. Not all strains that showed esterase activity exhibited high activity on triglycerides. Esterase and lipase activities were species- and strain-specific. Wide variations in activity between strains highlight the need for selecting appropriate starters to produce enzyme-modified cheese as well as accelerated ripened cheese.     

Production,mode of action and sequencing of the corresponding gene of a bacteriocin produced by Lactococcus lactis 19.3

Lactococcus lactis 19.3 produces a bacteriocin with a wide inhibitory spectrum, including the food pathogen Listeria monocytogenes. The producing strain was able to grow and produce similar amounts of bacteriocin in MRS medium, cow's milk and soya milk, respectively. The mode of action of this bacteriocin was further investigated using two indicator strains, Lactobacillus delbrueckii subsp. bulgaricus LMG 6901^T and Listeria monocytogenes ATCC 1911‐1. The bacteriocin displayed a bactericidal effect, causing a rapid decrease of the cell viability. Bacteriocin treatment of the sensitive strains resulted in major morphological changes, including pore formation, as shown by scanning electron microscopy. Finally, the bacteriocin‐encoding gene was identified by sequencing. The presence of nisin gene was confirmed. Based on all our data gathered so far, L. lactis 19.3 is a good candidate for a starter or protective culture in the manufacturing of both fermented dairy and vegetarian food products.     

Immediate and delayed effects of using a classroom case exemplar in teacher education: The role of presentation format.

Students learned teaching principles either with or without (control group) the presentation of a classroom exemplar in video or text format. Across 2 experiments, the video group produced higher transfer scores and affective ratings than the other groups. Four weeks later, the video group recalled more information about the exemplar than the text group, but no treatment effects were found on transfer. Qualitative analyses (Experiment 2) showed that the video group produced a significantly larger number of modeled behaviors in the transfer test than the text (immediate) and control (immediate and delayed) groups. Results encourage using classroom video exemplars to promote students' affect and retention, but suggest that additional pedagogies are needed to promote longer term transfer of theory into practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Castor-oil-modified epoxy resins as model systems of rubber-modified thermosets. 1: Thermodynamic analysis of the phase separation

Castor oil (CO) was used to replace polydisperse commercial rubbers (carboxy- or epoxy-terminated butadiene-acrylonitrile random copolymers, CTBN or ETBN) in model systems developed to analyse the origin of the phase separation process in rubber-modified thermosets. Mixtures of CO with an epoxy resin based on the diglycidyl ether of bisphenol A (DGEBA) showed a higher miscibility than a typical CTBN (18% acrylonitrile)-DGEBA system. Thermodynamic factors accounting for this behaviour are discussed using the Flory-Huggins lattice model. Addition of a stoichiometric amount of ethylenediamine (EDA) to a DGEBA-CO solution increased the miscibility. A pseudo-binary approach was used to fit the cloud point curve up to 30% volume fraction of CO. Percentage conversions at the cloud point during the DGEBA-EDA polymerization were experimentally determined and compared with theoretical predictions using the pseudo-binary approach in the framework of the Flory-Huggins lattice model. Reasonable agreement was found, giving direct evidence of the fact that phase separation results from the decrease in the entropic contribution to the free energy of mixing during polymerization.     

Washcoating of metallic monoliths with a MnCu catalyst for catalytic combustion of volatile organic compounds

A ready-made MnCu catalyst showing a good performance in the combustion of volatile organic compounds has been deposited on FeCrAlloy^® metallic monoliths by means of washcoating. With the aim of depositing a homogeneous and well-adhered layer of catalyst on the monoliths, the effects of a pre-coating with colloidal alumina as a primer, the solid concentration in the slurry, the addition of a stabilizer to the slurry, and the immersions number of the monolith in the slurry were studied. The addition of a stabilizer to the slurry was necessary to prevent sedimentation and to achieve reproducible washcoatings. The pre-coating of the monolith with the primer improved the washcoating adherence obtained with one impregnation but a better adherence did not compensate a lower solid load due to a lower surface roughness. A higher amount of deposited material was obtained with the slurry at 35 wt% making two impregnations. The obtained monoliths showed excellent catalytic activity in the combustion of ethyl acetate and toluene. The activity as well as the surface area and pore volume of each monolith increased with the amount of retained solid.