Xeno-free bioengineered human skeletal muscle tissue using human platelet lysate-based hydrogels

Bioengineered human skeletal muscle tissues have emerged in the last years as new in vitro systems for disease modeling. These bioartificial muscles are classically fabricated by encapsulating human myogenic precursor cells in a hydrogel scaffold that resembles the extracellular matrix. However, most of these hydrogels are derived from xenogenic sources, and the culture media is supplemented with animal serum, which could interfere in drug testing assays. On the contrary, xeno-free biomaterials and culture conditions in tissue engineering offer increased relevance for developing human disease models. In this work, we used human platelet lysate-based nanocomposite hydrogels (HUgel) as scaffolds for human skeletal muscle tissue engineering. These hydrogels consist of human platelet lysate reinforced with cellulose nanocrystals (a-CNC) that allow tunable mechanical, structural, and biochemical properties for the 3D culture of stem cells. Here, we developed hydrogel casting platforms to encapsulate human muscle satellite stem cells in HUgel. The a-CNC content was modulated to enhance matrix remodeling, uniaxial tension, and self-organization of the cells, resulting in the formation of highly aligned, long myotubes expressing sarcomeric proteins. Moreover, the bioengineered human muscles were subjected to electrical stimulation, and the exerted contractile forces were measured in a non-invasive manner. Overall, our results demonstrated that the bioengineered human skeletal muscles could be built in xeno-free cell culture platforms to assess tissue functionality, which is promising for drug development applications

Fusarium Mycotoxins and Metabolites that Modulate Their Production

The genus Fusarium is a group of fungi producing several types of toxins with toxicological effect in both humans and animals. Such fungi are commonly found in soils so it can contaminate various types of crops, preferably cereals, leading to significant economic losses. Relative humidity, storage temperature and various handling in cereales increase the possibility of contamination by Fusarium toxins. Cereals naturally have secondary metabolites that may help attenuate contamination by these toxins, but it is necessary to know strategies and mechanisms that generate inactivation mycotoxins. This chapter reviews relevant information about cereal mycotoxin contamination, as well as the production of cereal secondary metabolites as a strategy to reduce the possibility of mycotoxin contamination

Optimization in VHTS Satellite System Design with Irregular Beam Coverage for Non-Uniform Traffic Distribution

Very High Throughput Satellites (VHTS) have a pivotal role in complementing terrestrial networks to increase traffic demand. VHTS systems currently assume a uniform distribution of traffic in the service area, but in a real system, traffic demands are not uniform and are dynamic. A possible solution is to use flexible payloads, but the cost of the design increases considerably. On the other hand, a fixed payload that uses irregular beam coverage depending on traffic demand allows maintaining the cost of a fixed payload while minimizing the error between offered and required capacity. This paper presents a proposal for optimizing irregular beams coverage and beam pattern, minimizing the costs per Gbps in orbit, the Normalized Coverage Error, and Offered Capacity Error per beam. We present the analysis and performance for the case study and compare it with a previous algorithm for a uniform coverage area

Forward Link Optimization for the Design of VHTS Satellite Networks

The concept of geostationary VHTS (Very High Throughput Satellites) is based on multibeam coverage with intensive frequency and polarization reuse, in addition to the use of larger bandwidths in the feeder links, in order to provide high capacity satellite links at a reduced cost per Gbps in orbit. The dimensioning and design of satellite networks based on VHTS imposes the analysis of multiple trade-offs to achieve an optimal solution in terms of cost, capacity, and the figure of merit of the user terminal. In this paper, we propose a new method for sizing VHTS satellite networks based on an analytical expression of the forward link CINR (Carrier-to-Interference-plus-Noise Ratio) that is used to evaluate the trade-off of different combinations of system parameters. The proposed method considers both technical and commercial requirements as inputs, including the constraints to achieve the optimum solution in terms of the user G/T, the number of beams, and the system cost. The cost model includes both satellite and ground segments. Exemplary results are presented with feeder links using Q/V bands, DVB-S2X and transmission methods based on CCM and VCM (Constant and Variable Coding and Modulation, respectively) in two scenarios with different service areas

S-wave Meson-Meson Scattering from Unitarized U(3) Chiral Lagrangians

An investigation of the s-wave channels in meson-meson scattering is performed within a U(3) chiral unitary approach. Our calculations are based on a chiral effective Lagrangian which includes the eta' as an explicit degree of freedom and incorporates important features of the underlying QCD Lagrangian such as the axial U(1) anomaly. We employ a coupled channel Bethe-Salpeter equation to generate poles from composed states of two pseudoscalar mesons. Our results are compared with experimental phase shifts up to 1.5 GeV and effects of the eta' within this scheme are discussed.Comment: 18 pages, 6 figure

Convolutional Neural Networks for Flexible Payload Management in VHTS Systems

Very high throughput satellite (VHTS) systems are expected to have a large increase in traffic demand in the near future. However, this increase will not be uniform throughout the service area due to the nonuniform user distribution, and the changing traffic demand during the day. This problem is addressed using flexible payload architectures, enabling the allocation of the payload resources in a flexible manner to meet traffic demand of each beam, leading to dynamic resource management (DRM) approaches. However, DRM adds significant complexity to the VHTS systems, which is why in this article, we are analyzing the use of convolutional neural networks (CNNs) to manage the resources available in flexible payload architectures for DRM. The VHTS system model is first outlined, for introducing the DRM problem statement and the CNN-based solution. A comparison between different payload architectures is performed in terms of DRM response, and the CNN algorithm performance is compared by three other algorithms, previously suggested in the literature to demonstrate the effectiveness of the suggested approach and to examine all the challenges involved

Rudimentary G-Quadruplex-Based Telomere Capping In Saccharomyces Cerevisiae

Telomere capping conceals chromosome ends from exonucleases and checkpoints, but the full range of capping mechanisms is not well defined. Telomeres have the potential to form G-quadruplex (G4) DNA, although evidence for telomere G4 DNA function in vivo is limited. In budding yeast, capping requires the Cdc13 protein and is lost at nonpermissive temperatures in cdc13-1 mutants. Here, we use several independent G4 DNA-stabilizing treatments to suppress cdc13-1 capping defects. These include overexpression of three different G4 DNA binding proteins, loss of the G4 DNA unwinding helicase Sgs1, or treatment with small molecule G4 DNA ligands. In vitro, we show that protein-bound G4 DNA at a 3\u27 overhang inhibits 5\u27-\u3e 3\u27 resection of a paired strand by exonuclease I. These findings demonstrate that, at least in the absence of full natural capping, G4 DNA can play a positive role at telomeres in vivo

Temporal and spatial distribution fatal occupational injuries in Ecuador

Introduction: Ecuador is a country in South America, divided geographically by the Andean Mountain Range.  With the approval of the Resolution No C.D. 333 in 2010, companies are compelled to report all occupational accidents and diseases to the corresponding Occupational Health Public Organisms. Currently, there are no studies on the geographic and temporal distribution of deadly occupational accidents in the country. Objective: The objective of this study was to determine the temporal and geographic distribution of fatal occupational accidents (FOA) in Ecuador. Material-Methods: Ecologic Study of temporal and geographical distribution of FOA in the 24 provinces of Ecuador between 2010 and 2016. Data was obtained thru official secondary information sources. Gross and Adjusted Mortality Rates were calculated for workers affiliated to the General Mandatory Insurance, allowing the space representation in terms of the object of study. Results: During the period analyzed, 1.748 workers have passed due to work related accidents in Ecuador. The Gross Mortality Rate (x100.000-affiliated workers) presents a decreasing tendency from 2010 (13.2) to 2014 (6.3), increasing for 2015 (9.5). The main provinces with a higher Adjusted Mortality Rate (x10.000-affiliated workers) are located in the Amazon Region: Morona Santiago, Napo, Orellana and Sucumbíos. Conclusions: Ecuadorian Geography implies important differences in terms of FOA distribution by provinces and the compliance of legal norms in Safety and Occupational Health thru time. The temporal distribution and geographic representation of this phenomenon will allow the corresponding public control entities to identify provinces with high mortality rates and implement specific actions to prevent. The results of this study will help establish future research lines that will analyze more in depth this issue

Non-invasive ventilation in obesity hypoventilation syndrome without severe obstructive sleep apnoea

Background Non-invasive ventilation (NIV) is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS) who have concomitant severe obstructive sleep apnoea (OSA). However, there is a paucity of evidence on the efficacy of NIV in patients with OHS without severe OSA. We performed a multicentre randomised clinical trial to determine the comparative efficacy of NIV versus lifestyle modification (control group) using daytime arterial carbon dioxide tension (PaCO2) as the main outcome measure. Methods Between May 2009 and December 2014 we sequentially screened patients with OHS without severe OSA. Participants were randomised to NIV versus lifestyle modification and were followed for 2 months. Arterial blood gas parameters, clinical symptoms, health-related quality of life assessments, polysomnography, spirometry, 6-min walk distance test, blood pressure measurements and healthcare resource utilisation were evaluated. Statistical analysis was performed using intention-to-treat analysis. Results A total of 365 patients were screened of whom 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomised. NIV led to a significantly larger improvement in PaCO2 of -6 (95% CI -7.7 to -4.2) mm Hg versus -2.8 (95% CI -4.3 to -1.3) mm Hg, (p<0.001) and serum bicarbonate of -3.4 (95% CI -4.5 to -2.3) versus -1 (95% CI -1.7 to -0.2 95% CI) mmol/L (p<0.001). PaCO2 change adjusted for NIV compliance did not further improve the inter-group statistical significance. Sleepiness, some health-related quality of life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency towards lower healthcare resource utilisation in the NIV group. Conclusions NIV is more effective than lifestyle modification in improving daytime PaCO2, sleepiness and polysomnographic parameters. Long-term prospective studies are necessary to determine whether NIV reduces healthcare resource utilisation, cardiovascular events and mortality