In vitro technique for selecting onion FOR white rot disease- resistance

In vitro selection is one of the most effective and efficient techniques for plant improvement. This is due to its ability to isolate plants with the desired character(s), either by applying a selection agent on the culture media to drive the selection of somaclones with the required character(s), or by establishing particular conditions that change in the genomes of somaclones toward the required character. The objective of this study was to identify a suitable protocol for in vitro selection of Allium white rot disease ( Sclerotium cepivorum ) tolerance in commercial Egyptian onion varieties, namely Giza 20, Giza 6 and Beheri Red. Oxalic acid (OA), the phytotoxin produced by Sclerotium cepivorum, was used as the selective agent. Seeds of the three Egyptian varieties were germinated on four concentrations (0.0, 0.02, 0.2, 2 and 20 mM) of Oxalic acid. Among the tested cultivars, Beheri Red had the highest germination frequency (52%) at all concentrations tested, followed by Giza 20 (42.6%), and Giza 6 at (32%). Cotyledon explants from the varieties were cultured on toxic MSBDK> medium, supplemented with 0, 3, 6 and 12 mM OA. The survival of calli on MSBDK free toxic medium was 70.7% for all tested cultivars; however, MSBDK-stressed medium, with 3 mM OA reduced the viable calli to 42.1%. The highest OA concentration (12 mM) completely inhibited calli induction from cotyledons explants. A medium supplement with 3 mM OA retarded 80% of calli growth. Among 156 tested calli of Beheri Red, only 23 calli (14.7%) survived on toxic medium for 45 days. Similarly, there was 15.6% survival for Giza 20 calli, while 40.1% of the Giza 6 calli survived. Plantlets were regenerated from surviving calli and transplanted onto ex vitro, and formed bulb after acclimatisation.La selection In vitro est l\u2019une des techniques les plus efficaces en amelioration des plantes. Ceci est d\ufb \ue1 la capacit\ue9 qu\u2019\ue1 cette technique de permettre l\u2019isolation des plants avec des caract\ue8res d\ue9sir\ue9s. Ceci se fait de deux mani\ue8res; soit en appliquant un agent de selection sur le milieu de culture afin d\u2019orienter la s\ue9lection somaclonale de fa\ue7on \ue1 pr\ue9server le caract\ue8re desir\ue9, ou, en cr\ue9ant des conditions particuli\ue8res visant \ue1 modifier le genome afin dans le sens des caract\ue8res voulus. L\u2019ojectif de l\u2019\ue9tude \ue9tait d\u2019identifier un protocole ad\ue9quat pour la selection in vitro de la tol\ue9rance \ue1 la maladie de pourriture blanche ( Sclerotium cepivorum ) chez les vari\ue9t\ue9s commerciales d\u2019oignon en Egypte, en loccurence, Giza 20, Giza 6 et Beheri Red. L\u2019acide oxalique (OA), la phytotoxine produite par Sclerotium cepivorum, ont \ue9t\ue9 utilis\ue9s comme agent de s\ue9lection. Les semences des trois vari\ue9t\ue9s Egyptienne d\u2019oignon ont \ue9t\ue9 cultiv\ue9es sur quatre milieu de culture de diff\ue9rentes concentrations d\u2019acide oxalique (0.0, 0.02, 0.2, 2 et 20 mM). parmi les cultivars test\ue9s, Beheri Red avait la fr\ue9quence de germination la plus (52%) sur tous les quatre milieu de culture, puis vint Giza 20 (42,6%) et Giza 6 (32%). Des explants de cotyledons ont \ue9t\ue9 cultiv\ue9s sur milieu toxique MSBDK, additionn\ue9 de 0, 3, 6 et 12 mM de OA. Les calls survivants sur milieu toxique mais ne contenant pas de MSBDK \ue9tait de 70.7% pour tous les cultivars test\ue9s; n\ue9anmoins, le milieu contenant MSBDK, avec 3 mM de OA a caus\ue9 la r\ue9duction des calls viables de 42.1%. la plus forte concentration de OA (12 mM) a caus\ue9 une inhibiton complete de la r\ue9g\ue9ration des calls \ue1 partir des explants de cotyledons. Un milieu additionn\ue9 de 3 mM de OA \ue1 retard\ue9 la croissance des calls de 80%. Parmi les 156 calls de Beheri Red test\ue9s, seuls 23 calls, soit 14,7%, ont surv\ue9cu sur milieu toxique pendant 45 jours. De m\ueame, il y avait 15,6% de calls survivants Giza 20 calli, tandis que 40,1% des calls de Giza 6 ont surv\ue9cu. Des plantules ont \ue9t\ue9 r\ue9g\ue9n\ue9r\ue9 \ue1 partir des calls survivants et ceux ci ont \ue9t\ue9 transplant\ue9 sur milieu naturel, ils forment des bulbes d\u2019oignons apr\ue8s un temps d\u2019acclimatation

Stabilin receptors clear LPS and control systemic inflammation

Lipopolysaccharides (LPSs) cause lethal endotoxemia if not rapidly cleared from blood circulation. Liver sinusoidal endothelial cells (LSEC) systemically clear LPS by unknown mechanisms. We discovered that LPS clearance through LSEC involves endocytosis and lysosomal inactivation via Stabilin-1 and 2 (Stab1 and Stab2) but does not involve TLR4. Cytokine production was inversely related to clearance/endocytosis of LPS by LSEC. When exposed to LPS, Stabilin double knockout mice (Stab DK) and Stab1 KO, but not Stab2 KO, showed significantly enhanced systemic inflammatory cytokine production and early death compared with WT mice. Stab1 KO is not significantly different from Stab DK in circulatory LPS clearance, LPS uptake and endocytosis by LSEC, and cytokine production. These data indicate that (1) Stab1 receptor primarily facilitates the proactive clearance of LPS and limits TLR4-mediated inflammation and (2) TLR4 and Stab1 are functionally opposing LPS receptors. These findings suggest that endotoxemia can be controlled by optimizing LPS clearance by Stab1

A checklist of native freshwater fish from Brantas River, East Java, Indonesia

Hasan V, Mamat NB, South J, Ottoni FP, Widodo MS, Arisandi P, Isroni W, Jerikho R, Samitra D, Faqih AR, Simanjuntak CPH, Mukti AT. 2022. A checklist of native freshwater fish from Brantas River, East Java, Indonesia. Biodiversitas 23: 6031-6039. This study aims to provide information on the freshwater fish species composition of the Brantas River, the second-largest river in Java, Indonesia. All samples used in this study were the caught activities during Fish Resource Survey (form May 5, 2021 to August 20, 2022). Sampling was carried out in four stations of the Brantas River, representing upstream, the Karangkates Reservoir, midstream, and downstream. This work recorded 42 fish species divided into 35 genera and 21 families. Cyprinidae was the dominant family, comprising 12 genera and 15 species. According to the IUCN Red List, most fish species inhabiting the Brantas River have a conservation status of Least Concern (LC) or Data Deficient (DD), except for Rasbora lateristriata which is categorized as Vulnerable (VU). Genera Tor and Neolissochilus are rarely found in Javanese waters. We suggest that the conservation status of these species should be reviewed. Information on habitat use and ecological interactions of fish occurring in the Brantas River are needed urgently to make appropriate conservation decisions and plans. Therefore, we suggest that more collections need to be carried out in the studied river, as well as studies based on eDNA analysis and research incorporating both morphological and molecular data

Effect of cross section reduction on the mechanical properties of aluminium tubes drawn with variable wall thickness

Variable thickness tube drawing is a new process for the production of high performance tubes. In this study, experiments were conducted to evaluate the effect of cross section reduction on the microstructure and mechanical properties of variable thickness aluminium tubes drawn using two different position controlled mandrel techniques. Various tubes with three different outer diameters were subjected to cold drawing at room temperature from 11 percent to 41percent cross section reduction. The local mechanical properties were determined from tensile tests carried out on specimens cut from different positions in the tubes parallel to their axes. The distributions of the Vickers hardness over the surfaces at 0 deg and 90 deg to the drawing direction were examined. It was found that the microhardness, yield strength, and ultimate tensile of the deformed samples increase and the corresponding elongation decreases with the increase of cross section reduction. Also, the anisotropy in microstructure and mechanical properties is more significant with increasing of cross section reduction. The evolution of mechanical properties of drawn tubes versus cross section reduction depends on the mandrel shapes and initial tube outer diameter. This study helps to further understand the microstructure and mechanical properties evolutions during tube drawing process with variable thickness.Peer reviewed: YesNRC publication: Ye

Perspectives for the application of variable thickness aluminium tubes in hydroforming of complex tubes

Tubular products have very important applications in various areas especially in the transportation industries. For instance, in the structure of cars there are various tubular products like roof headers, engine cradles, roof rails and frame rails with complex geometries which most of them need multiple steps like tube drawing, tube bending and hydroforming for their production. Based on the recent studies by this group, it was proven that in most of the structural tubular parts in the cars it was not necessary to have constant thickness along the axial direction of tube and it will be considered as overdesign and the overall weight of structures can be reduced considerably by using variable thickness tubes. In this paper, the variable thickness tube drawing and its applications in the tube bending and hydroforming applications were studied. The results showed that this process can have important role in reduction of defective parts in the production of complex tubes by the tube hydroforming method. However especial considerations should be taken into account in the design of thickness distribution along axial direction of these kinds of tubes to avoid problems in the drawing step and as well in the bending and hydroforming steps. \ua9 (2011) Trans Tech Publications.Peer reviewed: YesNRC publication: Ye

Global optimisation of the production of complex aluminium tubes by the hydroforming process

With the recent development of analysis software products, designers and engineers are able to design more complex parts to obtain better performance in the final products. In this study, the tube hydroforming process, including preceding processes, i.e. variable thickness tube drawing and two-step bending, are globally optimised to obtain parts without any problems like bursting or un-filled zones at the end of the forming processes. Unlike most previous studies which searched for an optimum hydroforming process by changing two hydroforming parameters, i.e. axial load feeding and internal pressure, in this study, the distribution of initial tube wall thickness and the variation of thickness due to bending steps will be taken into account in a global optimisation algorithm. The developed algorithm is a general-purpose algorithm that can encompass different processes and change various parameters in each process to be able to reach the global objective. The case study used was a part that needs two-step variable thickness tube drawing, and two bending steps before hydroforming. To verify the numerical results in each forming stage and at the end of all forming processes, extensive experiments were performed, and acceptable agreements were observed.Peer reviewed: YesNRC publication: Ye

Application of a new procedure for the optimization of variable thickness drawing of aluminium tubes

The application of aluminium tubes, especially with variation of thickness, in the structures of various transportation devices like cars and bicycles makes it a point of interest for various designers. In this paper, the variable thickness tube drawing process was studied with a newly developed procedure to evaluate the effect of tools geometries on the maximum possible tube deformation. The procedure applies the desired variation in the design variables (die angle, mandrel angle, and die fillet radius) and the required adjustments and changes in the geometries with the aid of an in-house code automatically. Based on the optimized results, a die and a mandrel were built to verify numerical results in variable thickness tube drawing. The numerical results were compared with the experiments in the prototype machine, which was designed by this group, and acceptable agreements were observed.Peer reviewed: YesNRC publication: Ye

Investigation of the formability limit of aluminium tubes drawn with variable wall thickness

Structural aluminium tubes have very important industrial applications, particularly in automobile industry. Tube drawing process is widely used to reduce the outer and inner diameters of tubes. An important issue in the tube drawing process to obtain variable wall thickness is how to determinate and predict its formability limits. Previously published works generally deal with the formability limit of conventional tube drawing based on experimental analysis, analytical method and finite element method. However, in the case of variable wall thickness tubes, there is a lack of knowledge and data in order to predict their limit of formability. In the present study, both theoretical and experimental methods are proposed for estimating the formability limit of the variable wall thickness aluminium tubes used for the transportation purposes. A modification of a conical mandrel was proposed and a special control system for mandrel displacement during the process was used to carry out the drawing tests. During the drawing process, the tube pulling axis was controlled at constant speed while the mandrel was moved to achieve the continuously variable wall thickness. The formability limit in term of minimum wall thickness and maximum area reduction was obtained before tube rupture. These values are useful data for the determination of the extent of deformation during a drawing process that a material can experience without failure. The maximum drawing stress ratio was also determined experimentally. Further, an extension of an upper bound solution developed in previous publications is proposed to predict the drawing stress field. The maximum drawing stress ratio was used as a criterion for fracture analysis. It was shown that the analytical model with its new extension combined to the fracture criterion predicts quite well the thickness and area reduction limit. The experimental studies were completed by examining the microstructure and strain field at the limit state.Les structures tubulaires en aluminium ont de tr\ue8s importantes applications industrielles, particuli\ue8rement dans l\u2019industrie automobile. Le proc\ue9d\ue9 d\u2019\ue9tirage est couramment utilis\ue9 pour r\ue9duire les diam\ue8tres externes et internes des tubes. Un probl\ue8me majeur li\ue9 au proc\ue9d\ue9 d\u2019\ue9tirage de tube afin d\u2019obtenir une \ue9paisseur de paroi variable est de pouvoir d\ue9terminer et pr\ue9dire ses limites de formabilit\ue9. Des travaux d\ue9j\ue0 publi\ue9s traitent g\ue9n\ue9ralement de la limite de formabilit\ue9 de l\u2019\ue9tirage de tube classique fond\ue9e sur l\u2019analyse exp\ue9rimentale, la m\ue9thode analytique et la m\ue9thode des \ue9l\ue9ments finis. Toutefois, dans le cas des tubes d\u2019\ue9paisseur variable, peu de connaissances et de donn\ue9es existent qui permettent de pr\ue9dire leur limite de formabilit\ue9. Dans la pr\ue9sente \ue9tude, on propose des m\ue9thodes th\ue9oriques et exp\ue9rimentales pour estimer la limite de formabilit\ue9 de tubes d\u2019aluminium \ue0 paroi d\u2019\ue9paisseur variable, utilis\ue9s \ue0 des fins de transport. On propose la modification d\u2019un mandrin conique et l\u2019utilisation d\u2019un syst\ue8me de contr\uf4le particulier pour le d\ue9placement du mandrin au cours du processus, lors des essais d\u2019\ue9tirage. Au cours du proc\ue9d\ue9 d\u2019\ue9tirage, l\u2019axe d\u2019\ue9tirement du tube est r\ue9gl\ue9 \ue0 une vitesse constante pendant que le mandrin se d\ue9place pour obtenir l\u2019\ue9paisseur de paroi variable de fa\ue7on constante. On obtient la limite de formabilit\ue9 par l\u2019\ue9paisseur minimale de la paroi et la r\ue9duction maximale de la surface avant la rupture du tube. Ces valeurs constituent des donn\ue9es utiles pour d\ue9terminer le degr\ue9 de d\ue9formation que peut subir un mat\ue9riau avant qu\u2019il ne se rompe au cours d\u2019un proc\ue9d\ue9 d\u2019\ue9tirage. Le rapport de contrainte d\u2019\ue9tirage maximal est \ue9galement d\ue9termin\ue9 exp\ue9rimentalement. De plus, on propose une extension d\u2019une solution de limite sup\ue9rieure mise au point dans des publications ant\ue9rieures pour pr\ue9dire le champ de contrainte d\u2019\ue9tirage. Le rapport de contrainte d\u2019\ue9tirage maximal a servi de crit\ue8re dans l\u2019analyse des fractures. On montre que la combinaison du mod\ue8le analytique comportant sa nouvelle extension avec le crit\ue8re de fracture permet de pr\ue9dire particuli\ue8rement bien la limite d\u2019\ue9paisseur et de r\ue9duction de surface. Ces \ue9tudes exp\ue9rimentales sont r\ue9alis\ue9es en examinant la microstructure et le champ de d\ue9formation \ue0 l\u2019\ue9tat limite.Peer reviewed: YesNRC publication: Ye

Optimization on the Cold Drawing Process of 6063 Aluminium Tubes

To obtain the T832 material behaviour, 6063-T4 tubes need to be cold drawn before artificial aging to enhance their mechanical properties. Since a high area reduction is required, multiple drawing passes are generally necessary to avoid fracture of tubes during the drawing process. These several steps need a time consuming process which could be reduced by optimization. The optimization of the tools geometry has been done through a finite element model with the objective of reducing the maximum stress level to draw tubes in one pass. Based on the optimum design, a new tool was built and acceptable accordance was observed between experiments and numerical results.Peer reviewed: YesNRC publication: Ye