10 research outputs found
Development of Molecular Markers Tightly Linked to Pvr4 Gene in Pepper Using Next-Generation Sequencing
It is imperative to identify highly polymorphic and tightly linked markers of a known trait for molecular marker-assisted selection. Potyvirus resistance 4 (Pvr4) locus in pepper confers resistance to three pathotypes of potato virus Y and to pepper mottle virus. We describe the use of next-generation sequencing technology to generate molecular markers tightly linked to Pvr4. Initially, comparative genomics was carried out, and a syntenic region of tomato on
chromosome ten was used to generate PCR-based markers and map Pvr4. Subsequently, the genomic sequence of pepper was used, and more than 5000 single-nucleotide variants (SNVs) were identified within the interval. In addition, we identified nucleotide binding site–leucine-rich repeat-type disease resistance genes within the interval. Several of these SNVs were converted to molecular markers desirable
for large-scale molecular breeding programmes
Improvement of seismic performance of precast frames with cladding panels fastened by energy dissipative steel cushions
Precast reinforced concrete panels are commonly used as wall claddings in precast buildings. The cladding panels are generally evaluated as non-structural members and are joined to structural systems via mechanical, welding, and bolted dry connections. Several failures were observed in the last seismic events in Southern Europe, which demonstrate the deficiencies of the cladding connections in terms of strength and ductility. A comprehensive research activity named SAFECLADDING was conducted in Europe to provide knowledge for proper seismic design of precast structures with cladding panels. In this context, energy dissipative steel cushions were developed and evaluated through the extensive experimental and numerical studies. Steel cushions can provide robust interaction of the structural system with the cladding panels. This paper numerically evaluates the effects of cladding panels with steel cushions on the global seismic behaviour of the buildings. An existing representative industrial building is selected to perform intensive nonlinear dynamic analyses. Analyses performed on the bare and hybrid systems showed that the hybrid system has high performance in terms of story drifts, internal forces, and deformations with respect to the bare system. The overall drifts in longitudinal and transversal directions of the building are reduced by about 78 and 54%, respectively. Average residual drifts of cladding panels and steel cushions indicated that the applied steel cushion placement scheme has a promising re-centring capability during seismic action.The research presented herein was accomplished via the valuable experimental and numerical data derived FP7 project, "SAFECLADDING: Improved Fastening Systems of Cladding Wall Panels of Precast Buildings in Seismic Zones" research for SME associations, grant agreement number 314122, coordinated by Mr. Alessio Rimoldi from BIBM, Belgium. The financial support provided by the Commission of the European Communities through SAFECLADDING and other project partners are greatly acknowledged. The study was conducted at the Structural and Earthquake Engineering Laboratory (STEELab) of Istanbul Technical University. Support for the laboratory staff and graduate students is gratefully acknowledged.Publisher's Versio
Studies on the Adaptation of Azolla mexicana in the Aegean and the Mediterranean Regions
Azolla (Azolla anabaena) is an aquatic fern plant that can be used as a green manure and organic matter resource in many countries where irrigation water is not a problem. A. mexicana is one of the azolla species adapted to the environmental conditions of Izmir (Turkey). The objective of this research was to determine the adaptation and agronomic potential of azolla plants to the Mediterranean climate regions. The research was conducted at three locations (Izmir and Aydın located in the Aegean region and Antalya located in the Mediterranean region of Turkey) in 1999, 2000 and 2001. Fresh azolla was planted in April, May, June and October at the rate of 300 g m−2 at each application. The growing azolla plants were harvested 15 days after planting. The highest fresh yield (1481 g m−2) was obtained in April at Izmir. The total N, P, and K values were between 2.93-3.31 %, 0.43-0.54 % and 1.10-1.37 % at Izmir, Aydın, and Antalya, respectively. The shortest time to reach a two-fold increase was 3.53 days at Izmir based on the average of three years
Physical mapping of NBS-coding resistance genes to the Me-gene cluster on chromosome P9 reveals markers tightly linked to the N gene for root-knot nematode resistance in pepper
Natural root-knot nematode resistance genes are unique resources to control this major pest in pepper (Capsicum annuum). Although four genes (Me1, Me3, Me7 and N) conferring broad-spectrum resistance were mapped to a cluster in a 28-cm interval on chromosome P9, limited markers targeting this region were available. In the present study, the Me-gene cluster was structurally annotated for resistance genes to develop markers targeting the N gene. As a result, the Me-gene cluster (4.07 Mb in size) was found to contain three resistance gene hotspots. In addition, a SSR maker tightly linked to the N gene (0.8 cM away) was developed for marker-assisted selection in pepper.Scientific and Technological Research Council of Turkey (TOVAG 110O675
Cyclic behavior of reinforced concrete cladding panels connected with energy dissipative steel cushions
Precast concrete structures show damage after the destructive earthquakes and indicate that the connections of reinforced concrete (RC) cladding panels might be inadequate. RC cladding panels greatly increase the lateral stiffness and strength of the building when they are rigidly connected to the structural system. However, this also increases the seismic requirements. Consequently, a robust mechanical connection device with energy-dissipating capability was produced for RC cladding panels. Extensive experimental and numerical studies on an energy-dissipative steel cushion (SC) connection device were carried out in the framework of the SAFECLADDING project. Cladding panel tests were conducted with various connection configurations. The fundamental variables are the location, quantity, and thickness of SCs used in the cladding systems. The test results demonstrate that the SCs used in panel-to-panel and panel-to-support connections made large contributions to the total energy dissipation capacity. The parameters of a numerical model were also evaluated to reproduce the experimental results.This research was conducted in the framework of the FP7 project, "SAFECLADDING: Improved Fastening Systems of Cladding Wall Panels of Precast Buildings in Seismic Zones," research for SME associations, grant agreement number 314122, which was coordinated by Mr. Alessio Rimoldi from BIBM. The financial support provided by the Commission of the European Communities through this project is greatly appreciated. The study was conducted at the Structural and Earthquake Engineering Laboratory (STEELab) of Istanbul Technical University. The support of the laboratory staff and graduate students is gratefully acknowledgedPublisher's Versio
Uni-axial behavior of energy dissipative steel cushions
Seismic excitations may impart a significant amount of energy into structures. Modern structural design attitudes tend to absorb some part of this energy through special dissipaters instead of heavy plastic deformations on the structural members. Different types of dissipater have been generated and utilized in various types of structures in last few decades. The expected earthquake damage is mainly concentrated on these devices and they may be replaced after earthquakes. In this study, a low-cost device called energy dissipative steel cushion (EDSC) made of flat mild steel was developed and tested in the Structural and Earthquake Engineering Laboratory (STEELab) of Istanbul Technical University (ITU). The monotonic and cyclic tests of EDSC were performed in transversal and longitudinal directions discretely. Very large deformation capability and stable hysteretic behavior are some response properties observed from the tests. Load vs. displacement relations, hysteretic energy dissipation properties as well as the closed form equations to predict the behavior parameters are presented in this paper.The research presented herein was conducted in the framework of the FP7 project "SAFECLADDING: Improved Fastening Systems of Cladding Wall Panels of Precast Buildings in Seismic Zones" research for SME associations, grant agreement number 314122, which was coordinated by Mr. Alessio Rimoldi from BIBM. The financial support provided by the Commission of the European Communities through this project is greatly appreciated. The study was conducted at the Structural and Earthquake Engineering Laboratory (STEELab) of Istanbul Technical University. The support of the laboratory staff and graduate students is gratefully acknowledgedPublisher's Versio
Experimental investigation and pseudoelastic truss model for in-plane behavior of corrugated sandwich panels with polyurethane foam core
Sandwich panels are commonly used in facades and the roofs of industrial buildings due to their well-known advantages. However, there is limited data about the in-plane behavior of the panels. Hence, this paper aimed to propose a pseudoelastic truss model to represent the effective in-plane stiffness and strength properties of the corrugated sandwich panels with a polyurethane foam core. Two separate sets of experiments (mock-up and system test) were conducted in the laboratory. The variables were the number of fasteners, sheet thickness, loading direction, and number of ribs. The number of fasteners, sheet thickness, and loading direction are the most effective parameters for the in-plane behavior. A formula was proposed to compute axial stiffness of the truss members by considering the effective parameters. Experimental results showed that the proposed robust truss model could give a good estimate of the pseudoelastic stiffness and maximum load bearing capacity of the sandwich panels.Turkish Precast Concrete AssociationThis study was conducted in the framework of ITuNOVA Technology Transfer Office Research Project titled Determination of In-plane Behavior of Corrugated Sandwich Panel Type Roof Shelters. The finan-cial support provided by Turkish Precast Concrete Association through this project is greatly appreciated. The study was conducted at the Structural and Earthquake Engineering Laboratory (STEELab) of Istanbul Technical University. Support of the laboratory staff and the contributions of Gunkut Barka and Hakan Atakody are gratefully acknowledged
Behaviour of steel cushions subjected to combined actions
Mild steel is relatively low-cost and easily accessible material to fabricate some structural members. It would be a significant advantage if seismic energy dissipaters that are used in structures constructed in the earthquake prone areas, could also be produced on site. In this paper, a promising seismic energy dissipater made of mild steel, so-called steel cushion (SC) is presented. It is provided experimental and analytical responses of SCs subjected to bi-axial loadings. SC rolls under the lateral loading that allows relocation of the plasticized cross-section. Henceforth, SC dissipates considerable amount of seismic energy. A series of tests were performed to achieve experimentally the behavior of SC subjected to longitudinal and transversal loading. Finite Element Models (FEMs) were also generated to reproduce the experimental backbone curves and to predict the bi-directional response properties for discrete transversal forces and plate thicknesses. Closed-form equations were derived to determine yield and ultimate forces and the corresponding displacements as well as location of the plasticized sections. The behavior of SC could either be projected by the FEMs with the exhibited parameters or by means of the proposed closed-form equations and the normalized design chart