Combining abilities and heterotic groups in Pisum sativum L.

The objective of this research was to investigate the use of heterosis and estimates of the general combining ability (GCA) and specific combining ability (SCA) for yield and the yield-related traits for identifying suitable parents and forming heterotic groups for pea- breeding programs. Seventy-six F1 hybrids derived from crosses between nineteen female lines and four male testers were evaluated during two seasons. Estimates of variance due to GCA and SCA effects and their relationship revealed predominantly additive effects for all traits. Parents with higher GCA values were "ZAV20" (female parent) and "ZAV23" (male parent).The cross "ZAV5 x ZAV23" showed the highest value for seed yield. Days to flowering and number of seeds per plot were the variables with the highest values for broad and narrow-sense heritability (0.93 and 0.65, respectively), indicating that these traits are highly heritable. The highest best parent heterosis for seed yield was observed in the "ZAV17 x DDR14" hybrid. Four heterotic groups were formed and validated by estimating the intra and inter group heterosis.Fil: Espósito, María Andrea. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Gatti, Ileana. Universidad Nacional de Rosario; ArgentinaFil: Cravero, Vanina Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Lopez Anido, Fernando Sebastian. Universidad Nacional de Rosario; ArgentinaFil: Cointry Peix, Enrique Luis. Universidad Nacional de Rosario; Argentin

Repair and reinforcement of timber columns and shear walls – A review

This paper provides an overview of state-of-the-art repairing and reinforcing techniques on timber columns and shear walls in both research and practice. Both research projects in the laboratory scale and real repair/reinforcement projects are examined. It covers two levels of intervention; repair and reinforcement of timber elements. The former focuses on damaged elements and the latter focuses on enhancing the mechanical properties of the elements. Firstly the need to reinforce and repair timber columns and shear walls is discussed, followed by an extensive review of current techniques for repair and reinforcement. Advantages and disadvantages of different existing techniques are analysed so as to inform future practice and research. Finally, several important issues, such as reversibility and long term behaviour, are also discussed

Regulation of the PMP22 gene through an intronic enhancer

Successful myelination of the peripheral nervous system depends upon induction of major protein components of myelin, such as Peripheral Myelin Protein 22 (PMP22). Myelin stability is also sensitive to levels of PMP22, as a 1.4 Mb duplication on human chromosome 17, resulting in 3 copies of PMP22, is the most common cause of the peripheral neuropathy, Charcot-Marie-Tooth disease (CMT). The transcription factor Egr2/Krox20 is required for induction of high level expression of Pmp22 in Schwann cells but its activation elements have not yet been determined. Using chromatin immunoprecipitation analysis of the rat Pmp22 locus, we find a major peak of Egr2 binding within the large intron of the Pmp22 gene. Analysis of a 250 bp region within the largest intron showed that it is strongly activated by Egr2 expression in reporter assays. Moreover, this region contains conserved binding sites for not only Egr2 but also Sox10, which is also required for Schwann cell development. Our analysis shows that Sox10 is required for optimal activity of the intronic site as well as PMP22 expression. Finally, mouse transgenic analysis revealed tissue-specific expression of this intronic sequence in peripheral nerve. Overall, these data show that Egr2 and Sox10 activity are directly involved in mediating the developmental induction of Pmp22 expression

CAREER: Framework for Integrating Embedded Sensors in Durability Analysis of FRP Composites in Civil Infrastructure

The CAREER proposal will develop a framework to characterize durability of composites in civil infrastructure by integrating fiber-optic embedded sensors with damage mechanics models and life prediction methods. To tackle this problem, a combined analytical and experimental methodology is proposed, as follows: 1) Integrate embedded sensors in composites fabrication by VARTM and filament winding; 2) Implement strain, temperature, moisture and chemical degradation fiber-optic sensors; 3) Evaluate the embedded sensor system with controlled damage; 4) Develop a damage mechanics model and life-prediction methodology for durability analysis based on interrogating senors; 5) Assess reliability of sensor data and scale to composite structures (bridge decks and pipe walls); and 6) Validate the durability methodology and synthesize into a health-monitoring protocol. The educational approach is two-fold encompassing student recruitment and advanced graduate education. First, and educational collaboration is being developed with an applied technology center at a high school in Maine. The objective is to introduce high school students to the engineering experience by collaborating with civil engineering juniors in a composite bridge design and fabrication project. Second, an advanced graduate course on composites in civil engineering will be developed

3D-printed culvert diffusers to improve rural transportation resiliency

The increase in stormwater discharge, driven by climate change and land-use changes, has been exacerbated by the aging-related deterioration of existing diffusers, leading to culvert washouts. These washouts have significant consequences, blocking vehicle movement for days or even weeks, which disrupts access to disaster relief and emergency services in rural Maine, leaving these areas particularly vulnerable to storms. 3D-printed diffusers, as part of trenchless culvert rehabilitation technology, offer a potential solution to this problem. These diffusers enhance culvert discharge capacity, thereby helping to prevent washouts during high-discharge events caused by rainstorms. This trenchless technology avoids digging out and replacing old culverts offering cost-savings. Additionally, this technology is deployable without causing traffic disruptions. A prototype of the 3D-printed diffuser was successfully installed in Thorndike, ME, while a full system has been implemented on Route 85 in Rocky Brook, Newfields Rd, Exeter, NH. Further sites in Maine are being identified in collaboration with MaineDOT for additional implementations, aiming to strengthen infrastructure resilience across the state.https://digitalcommons.library.umaine.edu/rural_issues/1053/thumbnail.jp

Numerical Modeling and Experimental Investigation of Effective Elastic Properties of the 3D Printed Gyroid Infill

A numerical homogenization approach is presented for the effective elastic moduli of 3D printed cellular infills. A representative volume element of the infill geometry is discretized using either shell or solid elements and analyzed using the finite element method. The elastic moduli of the bulk cellular material are obtained through longitudinal and shear deformations of a representative volume element under periodic boundary conditions. The method is used to analyze the elastic behavior of gyroid infills for varying infill densities. The approach is validated by comparing the Young’s modulus and Poisson’s ratio with those obtained from compression experiments. Results indicate that although the gyroid infill exhibits cubic symmetry, it is nearly isotropic with a low anisotropy index. The numerical predictions are used to develop semi-empirical equations of the effective elastic moduli of gyroid infills as a function of infill density in order to inform design and topology optimization workflows

Integration of Material Characterization, Thermoforming Simulation, and As-Formed Structural Analysis for Thermoplastic Composites

An improved simulation-based thermoforming design process based on the integration of material characterization and as-formed structural analysis is proposed. The tendency of thermoplastic composites to wrinkle during forming has made simulation critical to optimized manufacturing, but the material models required are complex and time consuming to create. A suite of experimental methods has been developed for measurement of several required properties of the molten thermoplastic composite. These methods have the potential to enhance thermoplastic composites manufacturing by simplifying and expediting the process. These material properties have been verified by application to thermomechanical forming predictions using commercial simulation software. The forming predictions showed improved agreement with experimental results compared to those using representative material properties. A tool for using thermoforming simulations to inform more accurate structural models has been tested on a simple case study, and produced results that clearly differ from those of models using idealized fiber orientations and thicknesses. This provides evidence that this type of as-formed analysis may be necessary in some cases, and may be further investigated as an open source alternative to commercial analysis software

Combining Ability and Heterosis for Market Yield in Green Asparagus

In asparagus, current cultivars are mostly hybrids (known as clonal hybrids) derived from crosses between two parents, female and male, with good combining ability. Despite the fact that clonal hybrids have been obtained for more than 40 years, studies of the heterosis and combining abilities involved are limited. Similarly, there are no published studies regarding the association between genetic divergence and heterosis. In this sense, we evaluated two sets of diallel crosses including 12 accessions from 11 different origins for marketable green asparagus production. Parentals were also included as a way to assess heterosis. The variation for market yield was highly significant for both sets. Best parent heterosis was over 100% in four cases. The best experimental hybrid did not significant differ from the Atticus F1 all-male check. The general combining ability (GCA) and specific combining ability (SCA) were significant, with a relative greater contribution of the SCA than the GCA to the variation among crosses. The association between genetic distances and heterosis failed to be significant. The best experimental hybrids were obtained when UC157 and KBF (origins from the USA and the UK) were crossed to Argenteuil, Limburgia and Esparrago de Navarra (origins from France, the Netherlands and Spain).Fil: Amato, Lucía Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Martin, Eugenia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Lopez Anido, Fernando Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin

EFECTO DE UNA GENERACION DE SELECCION SOBRE CARACTERES PRODUCTIVOS EN UNA POBLACION DE ALCACHOFA (Cynara scolymus)

Selection response for productive characters in an open pollinated population of globe artichoke and clones derived of both generations (C0 and C1 ) were evaluated. By means of multivariate analysis, elite plants of C0 were selected and intercrossed to conform C1 . Selected plants of C0 and C1 were clonned and planted in a randomized complete block design with three replicates. Selection for marketable yield (42%) was related with increased total yield, head number (34%) and quality, but in turn associated to a slight reduction in mean head weight and mean bottom weight. Clones of C1 showed an increment of 25% in total and marketable yield over those of C0 . The selection gains for total marketable yield and head number are related to an additive gene action involved in the expression of these traits, however, for mean head weight the negative selection response is associated to non-additive gene effects.En una población obtenida por polinización libre entre distintos clones se evaluó la respuesta para caracteres productivos luego de un ciclo de selección comparándose el comportamiento de clones de alcachofa (Cynara scolymus L.), derivados de las poblaciones de ciclos cero (C0) y uno (C1). Los individuos de C1 se generaron por polinización libre de plantas de C0 seleccionadas por análisis multivariado, estimándose la ganancia por selección. Las plantas selectas de ambos ciclos fueron clonadas e implantadas en un diseño de bloques completos aleatorizados con tres repeticiones. Para el rendimiento de mercado se observó una ganancia del 42% debido a un mayor rendimiento total, dado por un 34% de aumento del número de capítulos y mejor calidad, acompañado de una leve disminución del peso y del peso de fondo. Los clones de C1 manifestaron un incremento del 25% en el rendimiento total y de mercado con respecto a aquellos obtenidos de C0. La ganancia por selección para rendimiento, rendimiento de mercado y número de capítulos se debería a la presencia, principalmente, de acciones aditivas aunque para peso del capítulo principal operarían efectos génicos no aditivos