Identification and Validation of EST-Derived Molecular Markers, TRAP and VNTRs, for Banana Research

The advent of high-throughput sequencing technology has generated abundant information on DNA sequences for the genomes of many plant species. Expressed Sequence Tags (ESTs), which are unique DNA sequences derived from a cDNA library and therefore representing genes transcribed in specific tissues or at some stage of development, are one type of DNA sequences highly available today for many important crop species. Molecular markers are used for bridging DNA sequence information with particular phenotypes and are useful tools for genotyping germplasm collections and also for tagging genes involved in desirable agronomic traits. In this sense, there is always a strong demand for suitable marker techniques to better utilise existing sequence information. A transcriptome database from banana (Musa spp.), DATAMusa, containing 42,724 ESTs from 11 different cDNA libraries and encompassing approximately 24 Mb of DNA sequence, was used in this study for the design of primers to PCR-amplify two types of EST-derived molecular markers, Variable Nucleotide Tandem Repeat (VNTR) and Target Region Amplification Polymorphism (TRAP). These primers were then validated against a panel of 14 diploid Musa genotypes and produced 32 (VNTR) and 119 (TRAP) alleles. Used separately or together, both types of markers were able to discriminate Musa genotypes from different genome background (A or B genomes). The TRAP alleles identified were derived from only one EST, while the VNTR alleles were derived from 12 unigenes. Based on the results of this study, EST-derived markers can be an important source of polymorphism to be used in genetic diversity and gene discovery studies in banan

Variable number of tandem repeat markers in the genome sequence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana (Musa spp)

ABSTRACT. We searched the genome of Mycosphaerella fijiensis for molecular markers that would allow population genetics analysis of this plant pathogen. M. fijiensis, the causal agent of banana leaf streak disease, also known as black Sigatoka, is the most devastating pathogen attacking bananas (Musa spp). Recently, the entire genome sequence of M. fijiensis became available. We screened this database for VNTR markers. Forty-two primer pairs were selected for validation, based on repeat type and length and the number of repeat units. Five VNTR markers showing multiple alleles were validated with a reference set of isolates from different parts of the world and a population from a banana plantation in Costa Rica. Polymorphism information content values varied from 0.6414 to 0.7544 for the reference set and from 0.0400 and 0.7373 for the population set. Eighty percent of the polymorphism information content values were above 0.60, indicating that the markers are highly informative. These markers allowed robust scoring of agarose gels and proved to be useful for variability and population genetics studies. In conclusion, the strategy we developed to identify and validate VNTR markers is an efficient means to incorporate markers that can be used for fungicide resistance management and to develop breeding strategies to control banana black leaf streak disease. This is the first report of VNTR-minisatellites from the M. fijiensis genome sequence. Key words: Molecular markers; VNTRs; Genetic diversity; Population genetics; Black Sigatok

Application of a cost-benefit model to evaluate the investment viability of the small-scale cogeneration systems in the Portuguese context

Increasingly, modern society is dependent on energy to thrive. Remarkable attention is being drawn to high energy-efficient conversion systems such as cogeneration. World energy sustainability depends on the rational use of energy, fulfilling the demands without compromising the future of energy supply. The market trends foresee the use of decentralized production and the increasing replacement of conventional systems by small-scale cogeneration units as solutions to meet the energy needs of the building sector. Analysing the influence of the variables that determine the economic viability of decentralized energy production systems has become more important given the scenario of energy dependence and high energy costs for the final consumer. A cost-benefit model was developed and presented to identify the potential of small commercial scale cogeneration systems in the Portuguese building sector, based on cost-benefit analysis methodology. Five case-scenarios were analysed based on commercial models, using different technologies such as internal combustion engines, gas turbines and Stirling engines. A positive value of CBA analysis was obtained for all the tested cases, however, the use of classic economic evaluation criteria such as the net present value, internal rate of return and payback period results led to different investment decisions. The model also highlights the influence of energy prices in the economic viability of these energy power plants. The inclusion of subsidized tariffs for efficient energy production is the most contributing aspect in the analysis of the economic viability of small-scale cogeneration systems in the Portuguese building sector. Only in that case, it would be possible for an investor to recover the capital costs of such technology, even if the technical and societal benefits are accounted for

Spatial distribution of bed variables, animal welfare indicators, and milk production in a closed compost-bedded pack barn with a negative tunnel ventilation system

This research aimed to characterize, evaluate and compare the spatial distribution of the leading bed variables, animal welfare indicators, and milk production in a closed compost-bedded pack barn (CBP) with a negative tunnel ventilation system, for summer and winter periods. The study was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. The geostatistical modeling technique evaluated the variables of temper ature, moisture content, and pH (on the surface and depth of 0.20m) across the length of the bed. Bed samples were characterized for carbon (C), nitrogen (N), and C:N ratio. Cows housed in the CBP were assessed for locomotion and hygiene scores and average milk production. To evaluate the thermoregulation of the cows, the respiratory rate (RR) and surface temperature (ST) were measured. Geostatistical analysis showed spatial dependence and the non-uniformity of the spatial distribution of bed variables. The worst levels of bed tem perature and moisture were found in the regions close to the evaporative cooling plate, surrounding the feeding alley, and in the region with the highest cow stocking. The C:N ratio, obtained in both climatic seasons of the year, remained outside the recommended range for ideal composting. During the summer and winter, the bed variables’ values suggest that the material was below levels for optimal composting; however, the aerated inner layer was biologically active. The high animal density significantly impacted the worsening of the bed moisture content and internal temperature. In general, dairy cows showed adequate hygiene (score of 1 and 2) and locomotion (score of 0 and 1) scores for the two climatic seasons evaluated, indicating good welfare conditions. In relation to RR and ST, the summer period presented less favorable environmental conditions. During winter, the average milk production was 28.1 ± 7.2 kg day-1, and during summer, it was 26.9 ± 6.7 kg day-1

Sliding wear behavior of Al2O3-NbC composites obtained by conventional and nonconventional techniques

[EN] This study aims to investigate the dry sliding wear behavior of Al2O3 5vol.%NbC nanocomposite sintered by conventional and spark plasma sintering at temperatures from 1450 to 1600 ºC. The tests were performed using WC 6 wt%Co balls as a counterpart material, a load of 30 and 60 N, a sliding distance of 2000 m and a sliding speed of 0.1 m/s. The consolidation techniques influenced the friction coefficient, wear rates and patterns. Samples tested at 30 N showed better wear resistance than the samples tests with 60 N. The nanocomposites obtained by SPS at 1500 ºC exhibited a lower friction coefficient and wear rate compared to all other materials. The results indicated that Al2O3-NbC nanocomposites show promise as material for cutting tool applications.This work has been financial support by the Brazilian institution CAPES for the project CAPES-PVE A086/2013 (project No 23038.009604/2013-12). A. Borrell acknowledges the Spanish Ministry of Economy and Competitiveness for her Juan de la Cierva-Incorporacion contract (IJCI-2014-19839).Ribeiro-Rodrigues Alecrim, L.; Ferreira, J.; Gutierrez-Gonzalez, C.; Salvador Moya, MD.; Borrell Tomás, MA.; Pallone, E. (2017). Sliding wear behavior of Al2O3-NbC composites obtained by conventional and nonconventional techniques. Tribology International. 110:216-221. https://doi.org/10.1016/j.triboint.2017.02.028S21622111

Development of mechanical engineering curricula at the University of Minho

The implementation of the Bologna protocol in the European Union has set new goals for the whole higher education system as: (a) a quality assessment for university courses; (b) a framework for the exchange of students and academics; and (c) an opportunity for changing the teaching/learning procedures and methodologies. Within the context, the mechanical engineering curricula at the University of Minho have been comprehensively formulated in order to meet these and future challenges and expectations. The whole process has been based upon various cornerstones: the legal framework for the higher education system; the introduction of new learning methodologies and an accurate survey and understanding of the existing strong and week points of the previous experience. For this purpose, a comprehensive evaluation has been carried out with former students and a detailed map has been formulated regarding their professional careers and experiences. Furthermore, a discussion has been carried out in order to define the mission of the graduate in mechanical engineering. In brief, such mission may be referred by his ability to participate in the wealth creation through technology based innovation. Within this context, the curriculum has been structured in order to meet such goals. In addition to strong foundations in physics and mathematics, new subjects are introduced into the curriculum. The whole education is based upon project development which stimulates the students’ initiative, responsibility and their ability to integrate knowledge. Throughout the curriculum, students are enrolled into research projects developed in the department and it is expected that a few selected projects may be taken into a quasi industrial stage.(undefined

Characterization at 25°C of Sodium Hyaluronate in Aqueous Solutions Obtained by Transport Techniques

Mutual diffusion coefficients, D, were determined for aqueous solutions of sodium hyaluronate (NaHy) at 25°C and concentrations ranging from 0.00 to 1.00 g·dm-3 using the Taylor dispersion technique. From these experimental data, it was possible to estimate some parameters, such as the hydrodynamic radius Rh, and the diffusion coefficient at infinitesimal concentration, D0, of hyaluronate ion, permitting us to have a better understanding of the structure of these systems of sodium hyaluronate in aqueous solutions. The additional viscosity measurements were done and Huggins constant, kH, and limiting viscosity number, [η], were computed for interaction NaHy/water and NaHy/NaHy determination. © 2015, MDPI AG. All rights reserved.PTDC/AAC-CLI/118092/2010, FCT, Fuel Cycle TechnologiesFCT [PTDC/AAC-CLI/118092/2010]; Coimbra Chemistry Centre from the FCT [Pest-OE/QUI/UI0313/2014]; Centre of Polymer Systems [CZ.1.05/2.1.00/03.0111]; TBU in Zlin - specific university research and national budget of Czech Republic [IGA/FT/2013/015, IGA/FT/2014/018]; [SFRH/BD/72305/2010

Inverse problems with partial data for a magnetic Schr\"odinger operator in an infinite slab and on a bounded domain

In this paper we study inverse boundary value problems with partial data for the magnetic Schr\"odinger operator. In the case of an infinite slab in $R^n$, $n\ge 3$, we establish that the magnetic field and the electric potential can be determined uniquely, when the Dirichlet and Neumann data are given either on the different boundary hyperplanes of the slab or on the same hyperplane. This is a generalization of the results of [41], obtained for the Schr\"odinger operator without magnetic potentials. In the case of a bounded domain in $R^n$, $n\ge 3$, extending the results of [2], we show the unique determination of the magnetic field and electric potential from the Dirichlet and Neumann data, given on two arbitrary open subsets of the boundary, provided that the magnetic and electric potentials are known in a neighborhood of the boundary. Generalizing the results of [31], we also obtain uniqueness results for the magnetic Schr\"odinger operator, when the Dirichlet and Neumann data are known on the same part of the boundary, assuming that the inaccessible part of the boundary is a part of a hyperplane

Passivation and dissolution mechanisms in ordered anodic tantalum oxide nanostructures

Tantalum oxide (Ta2O5) nanostructures exhibit outstanding electrical and optical properties, as well as, high chemical resistance and stability. These materials have great potential for biomedical, catalysis, semiconductors and energy applications due to their large surface area and high specific charge, when arranged in nanoporous or nanotubular morphologies. In order to obtain these structures, an anodization process, which is inexpensive, reproducible and easy to scale up, is used. Yet, depending on the anodization conditions, the formation of a nanoporous or nanotubular layer is difficult to stabilize during the anodization process. In this regard, anodized tantalum oxide nanostructures were produced to understand the effect of the anodization conditions, including electrolyte concentration, potential and time. The nanopores or nanotubes morphologies, their chemical composition and structure were investigated by FIB-SEM, double-corrected TEM-STEM and EDS. We found that it is necessary to have high acid concentrations (mixture of H2SO4 with HF) to be able to form nanoporous or nanotubular structures. Despite the capacity of HF to dissolve and create anodic oxide nanostructures, the amount of H2SO4 concentration in the mixture is very important, leading to a dimple morphology. Furthermore, the increase of the anodization potential/electrical field clearly leads to an increase in the dimples diameter.This research is sponsored by FEDER funds through the program COMPETE -Programa Operacional Factores de Competitividade and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020, and UID/EMS/00285/2020 and with a PhD fellowship SFRH/BD/98199/2013.The authors thank the financial support in the framework of HEALTHYDENT -POCI-01-0145-FEDER-030708 and PTDC/CTM-NAN/4242/2014 projects.This work was supported by FCT, through IDMEC, under LAETA, project UIDB/50022/2020.The authors would like to acknowledge that this project has received funding from the EU Framework Programme for Research and Innovation H2020, scheme COFUND -Co-funding of Regional, National and International Programmes, under Grant Agreement 713640