Enhancement of collagen deposition and cross-linking by coupling lysyl oxidase with bone morphogenetic protein-1 and its application in tissue engineering

Cultured cell-derived extracellular matrices (ECM)-based biomaterials exploit the inherent capacity of cells to create highly sophisticated supramolecular assemblies. However, standard cell culture conditions are far from ideal given the fact that the diluted microenvironment does not favor the production of ECM components, a circumstance particularly relevant for collagen. An incomplete conversion of procollagen by C-proteinase/bone morphogenetic protein 1 (BMP1) has been proposed to severely limit in vitro collagen deposition. BMP1 also catalyzes the proteolytic activation of the precursor of the collagen cross-linking enzyme, lysyl oxidase (LOX) to yield the active form, suggesting a deficit in cross-linking activity under standard conditions. We hypothesized that the implementation of fibroblast cultures with LOX and BMP1 may be an effective way to increase collagen deposition. To test it, we have generated stable cell lines overexpressing LOX and BMP1 and studied the effect of supernatants enriched in LOX and BMP1 on collagen synthesis and deposition from fibroblasts. Herein, we demonstrate that the supplementation with LOX and BMP1 strongly increased the deposition of collagen onto the insoluble matrix at the expense of the soluble fraction in the extracellular medium. Using decellularization protocols, we also show that fibroblast-derived matrices regulate adipogenic and osteogenic differentiation of human mesenchymal stem cells (MSC), and this effect was modulated by LOX/BMP1. Collectively, these data demonstrate that we have developed a convenient protocol to enhance the capacity of in vitro cell cultures to deposit collagen in the ECM, representing this approach a promising technology for application in tissue engineeringTis work was supported by grants from Ministerio de Economía y Competitividad (Plan Nacional de I+D+I: SAF2012-34916, and SAF2015-65679-R to F.R-P

Recent progress on truncated Toeplitz operators

This paper is a survey on the emerging theory of truncated Toeplitz operators. We begin with a brief introduction to the subject and then highlight the many recent developments in the field since Sarason's seminal paper in 2007.Comment: 46 page

Optimal Policy Derivation for Transmission Duty-Cycle Constrained LPWAN

Low-power wide-area network (LPWAN) technologies enable Internet of Things (IoT) devices to efficiently and robustly communicate over long distances, thus making them especially suited for industrial environments. However, the stringent regulations on the usage of certain industrial, scientific, and medical bands in many countries in which LPWAN operate limit the amount of time IoT motes can occupy the shared bands. This is particularly challenging in industrial scenarios, where not being able to report some detected events might result in the failure of critical assets. To alleviate this, and by mathematically modeling LPWAN-based IoT motes, we have derived optimal transmission policies that maximize the number of reported events (prioritized by their importance) while still complying with current regulations. The proposed solution has been customized for two widely known LPWAN technologies: 1) LoRa and 2) Sigfox. Analytical results reveal that our solution is feasible and performs remarkably close to the theoretical limit for a wide range of network activity patterns

Price Dynamics and Cointegration in the Major Markets of Aquaculture Species in the Philippines

This study explores the interdependencies of aquaculture markets in the Philippines by establishing the price cointegration between the wholesale and retail prices of three major species commonly farmed in the country, i.e., milkfish, tilapia, and shrimp. The co-movements of wholesale prices between and among key markets for each species are also investigated. Moreover, exogeneity in prices is established using the Granger-causation model to determine the existence of price leaders among these markets. These information are crucial because they may provide a better understanding of the efficiency in price formation across production and consumption centers. Thus, aquaculture producers and traders may use these information as basis for more efficient farm management and marketing decisions. Appropriate policies for the development of markets for the three aquaculture species are also identified in this study. Such policies are expected to contribute towards more efficient pricing and distribution of benefits among market players and stakeholders. These benefits are expected to manifest through the system of grading standards for fish traded in local markets, and the choice of cost-effective technologies in grow-out and post-production practices.

Comparative analysis of Bacillus weihenstephanensis KBAB4 spores obtained at different temperatures

The impact of Bacillus weihenstephanensis KBAB4 sporulation temperature history was assessed on spore heat resistance, germination and outgrowth capacity at a temperature range from 7 to 30 °C. Sporulation rate and efficiency decreased at low temperature, as cells sporulated at 12, 20 and 30 °C with approximately 99% efficiency, whereas at 7 °C and 10 °C, a maximum 15% of sporulation was reached. Spores formed at 30 °C showed the highest wet heat resistance at 95 °C, with spores formed at 7 and 10 °C displaying only survival of 15 min exposure at 70 °C, indicating their low level heat resistance. RT-PCR analysis revealed expression of sporulation sigma factor sigG, and germinant receptor operons gerI, gerK, gerL, gerR, gerS, and (plasmid-located) gerS2 to be activated in all sporulation conditions tested. Subsequent germination assays revealed a combination of inosine and L-Alanine to be very efficient, triggering over 99% of the spores to germinate, with spores obtained at 30 °C showing the highest germination rates (99%). Notably, spores obtained at 12, 20 and 30 °C, germinated at all tested temperatures, showing > 70% spore germination even at temperatures as low as 5 °C. Less than 5% of spores obtained at 7 and 10 °C showed a germination response. Furthermore, spores produced at 12, 20 and 30 °C showed similar outgrowth effiency at these temperatures, indicating that low temperature sporulation history does not improve low temperature outgrowth performance. Insights obtained in sporulation and germination behaviour of B. weihenstephanensis KBAB4, in combination with the availability of its genome sequence, may contribute to our understanding of the behaviour of psychrotolerant spoilage and pathogenic Bacill