Search Results (8)

This study builds on previous research into the basic flow structure of a separated curved swept compression ramp shock wave/turbulence boundary layer interaction (CSCR-SWBLI) at the leading edge of an inward-turning inlet. We employ the ice-cluster-based planar laser scattering (IC-PLS) technique, which integrates multiple observation directions and positions, to experimentally investigate a physical model with typical parameter states at a freestream Mach number of 2.85. This study captures the fine structure of some sections of the flow field and identifies the presence of Görtler vortices (GVs) in the CSCR-SWBLI. It is observed that due to the characteristics of variable sweep angle, variable intensity interaction, and centrifugal force, GVs exhibit strong three-dimensional characteristics in the curved section. Additionally, their position is not fixed in the spanwise direction, demonstrating strong intermittence. As the vortices develop downstream, their size gradually increases while the number decreases, always corresponding to the local boundary layer thickness. When considering the effects of coupling of bilateral walls, it is noted that the main difference between double-sided coupling and single-sided uncoupling conditions is the presence of a large-scale vortex in the central plane and an odd number of GVs in the double-sided model. Finally, the existence of GVs in CSCR-SWBLI is verified through the classical determine criteria Görtler number (G_T) and Floryan number (F) decision basis. Full article

The accuracy of X-ray fluorescence spectrometry in quantitative element analysis depends on the particular sample composition (so-called matrix effects). Counteracting these effects requires a large number of calibration samples similar in composition to those under analysis. Application of the model constructed for a particular type of samples is not possible for the analysis of samples having a different matrix composition. A possible solution for this problem can be found in the construction of universal calibration models. We propose the development of these universal models using chemometric tools: influence coefficients—partial least squares regression (IC-PLS) and nonlinear kernel regularized least squares regression. We hypothesize that the application of these methods for constructing calibration models would allow embracing the samples of different types in the framework of a single model. We explored this approach for the case of two substantially different types of samples: ores and steels. The performance of these methods was compared with the fundamental parameters (FP) method, which takes into account matrix effects using theoretical equations and allows handling samples of different elemental composition. IC-PLS significantly outperforms traditional FP in terms of accuracy for predicting the content of Al (root mean squared error of prediction 0.96% vs. 3.87%) and Ti (0.05% vs. 0.09%) and yields comparable results for Si and Mn quantification in ores and steels. Full article

Phytophthora, a blight of pigeonpea caused by Phytophthora cajani, has been significantly increasing in major pigeonpea production regions of India. Limited information on infection with this pathogen and its epidemiology, as well as a lack of adequate resistant cultivars, is hampering the management of Phytophthora blight significantly. Therefore, five fungicides, viz., metiram + dimethomorph, cymoxanil + mancozeb, famoxadone + cymoxanil, mancozeb, and metalaxyl-M + mancozeb, were evaluated against P. cajani under control conditions to control zoospore induction, as well as the infection of zoospores, at the seedling stage. The half-maximal effective concentration (EC50) of fungicides for mycelial inhibition was calculated. The lowest EC50 was recorded in metiram + dimethomorph (0.17 µg/mL), followed by the metalaxyl-M + mancozeb (2.49 µg/mL) and cymoxanil + mancozeb (8.23 µg/mL) fungicides. The formation of the sporangium and zoospores was most significantly affected by metalaxyl-M + mancozeb, followed by metiram + dimethomorph and cymoxanil + mancozeb, in terms of sporangia viability and zoospore germination and encystment. Further, under glasshouse conditions, different fungicide application methods (e.g., seed-treatment; soil-drench; foliar-spray, either singly or in combinations) were evaluated with fungicides on susceptible (ICP 7119) moderately resistant pigeonpea (ICPL 99010, ICPL 20135 and ICPL 99048) cultivars. The seed-treatment + soil-drench, soil-drench + foliar-spray, and soil-drench of fungicide application methods were found to be effective in controlling the Phytophthora blight, at p < 0.001. A combination of the seed-treatment + soil-drench and soil-drench + foliar-spray methods, using metalaxyl-M + mancozeb or metiram + dimethomorph fungicides on moderately resistant cultivars (ICPL 99010), has a synergistic effect on the ability to control the Phytophthora blight at the seedling stage. Full article

Pigeonpea [Cajanus cajan (L.) Millspaugh] is an economically important legume playing a crucial role in the semi-arid tropics. Pigeonpea is susceptible to Helicoverpa armigera (Hübner), which causes devastating yield losses. This pest is developing resistance to many commercially available insecticides. Therefore, crop wild relatives of pigeonpea, are being considered as potential sources of genes to expand the genetic base of cultivated pigeonpea to improve traits such as host plant resistance to pests and pathogens. Quantitative proteomic analysis was conducted using the tandem mass tag platform to identify differentially abundant proteins between IBS 3471 and ICPL 87 tolerant accession and susceptible variety to H. armigera, respectively. Leaf proteome were analysed at the vegetative and flowering/podding growth stages. H. armigera tolerance in IBS 3471 appeared to be related to enhanced defence responses, such as changes in secondary metabolite precursors, antioxidants, and the phenylpropanoid pathway. The development of larvae fed on an artificial diet with IBS 3471 lyophilised leaves showed similar inhibition with those fed on an artificial diet with quercetin concentrations with 32 mg/25 g of artificial diet. DAB staining (3,3′-diaminobenzidine) revealed a rapid accumulation of reactive oxygen species in IBS 3471. We conclude that IBS 3471 is an ideal candidate for improving the genetic base of cultivated pigeonpea, including traits for host plant resistance. Full article

Pigeonpea (Cajanus cajan (L.) Millsp.) is grown globally for its protein-rich seed. However, low availability of soil zinc (Zn) adversely affects the seed yield of pigeonpea. The present study was therefore conducted to assess the Zn efficiency of pigeonpea genotypes based on seed yield and seed Zn uptake efficiency. Field experiments were conducted at the Indian Council of Agricultural Research–Indian Institute of Soil Science, Bhopal, India with twenty different pigeonpea genotypes and two levels of Zn application under a split-plot design. The two levels of Zn were low (without application of Zn fertilizer) and high (with application of 20 kg Zn ha⁻¹ (as ZnSO₄∙7H2O) as basal soil application, in conjunction with three foliar sprays of 0.50% (w/v) ZnSO₄∙7H₂O aqueous solution) (with 0.25% lime as neutralizing agent) at flowering, pod formation, and pod filling stages). Application of Zn improved plant height, branches plant⁻¹, pods plant⁻¹, seeds pod⁻¹, and 100 seed weight of pigeonpea genotypes differently. The mean seed yield, seed Zn concentration, and seed Zn uptake of the genotypes increased from 1.71 to 2.12 t ha⁻¹, 32.4 to 43.0 mg kg⁻¹, and 54.9 to 90.6 g ha⁻¹, respectively, with application of Zn. The seed yield efficiency index (SYEI) and Zn uptake efficiency index (ZUEI) of pigeonpea genotypes varied from 67.0 to 92.5 and from 47.0 to 69.9, respectively. Based on SYEI and ZUEI, the genotypes were classified as efficient and responsive (Virsa Arhar-1, GT-1, GT-101, SKNP 05-05, BDN-2, AAUT 2007-04, BSMR 853, T 15-15, DT 23, Pusa 9), efficient and non-responsive (ICPL 87119, PKV Trombay), inefficient and responsive (AKT 8811, Hisar Paras), and inefficient and non-responsive (AAUT 2007-10, JKM 7, Hisar Manak, C 11, Hisar HO2-60, GAUT 93-17). The efficient and responsive genotypes are the most useful as they yield well under low soil Zn conditions and also respond to Zn fertilizer application. The inefficient and responsive genotypes could be utilized for plant breeding programs by plant breeders for identification and utilization of responsive traits. Full article

Cajanus scarabaeoides (L.), Thouars, is the closest wild crop relative of cultivated pigeonpea, Cajanus cajan (L.), Millspaugh. This wild pigeonpea has several insect-resistance mechanisms, particularly to Helicoverpa armigera (Hübner). Estimated economic losses in the semi-arid tropics from H. armigera damage in pigeonpea are approximately two billion USD/year. Therefore, it is imperative to improve pest resistance in this crop. In this study, we investigated insect-resistance components in IBS 3471, a C. scarabaeoides accession, and explored the possibility of transferring resistance mechanism/s to cultivated pigeonpea. A detached leaf bioassay revealed that IBS 3471 has more effective antibiosis and antixenosis resistance mechanisms against H. armigera compared to the susceptible C. cajan variety, ICPL 87. To further investigate the antibiosis resistance mechanism, we fed H. armigera larvae a heated and non-heated artificial diet supplemented with lyophilised IBS 3471 leaf powder. Incorporation of IBS 3471 leaf powder inhibited H. armigera larval weight and delayed larval development compared to larvae reared on diet supplemented with ICPL 87 leaf powder. The putative insect-resistance compounds in C. scarabaeoides were heat-labile. Proteomic analysis revealed higher levels of potential insecticidal proteins, namely lectin and cysteine proteinase inhibitor, in wild pigeonpea compared to the cultivated variety. Nutritional analysis and interspecific hybridisation experiments also indicated that IBS 3471 is a potential candidate for improvement of insect-resistance in pigeonpea. This study demonstrates that IBS 3471 has multiple resistance mechanisms against H. armigera, and they are transferable to cultivated pigeonpea. Full article

Cajanus scarabaeoides (L.) Thouars is the closest wild relative of cultivated pigeonpea, Cajanus cajan (L.) Millspaugh. However, unlike cultivated pigeonpea which is very susceptible to insects, especially Helicoverpa armigera (Hubner), this wild pigeonpea is strongly insect resistant. Since H. armigera causes damage to many important crops resulting in economic losses up to 2 billion USD/year, improvement in resistance to this insect in crops is highly desirable. Here we investigate insect resistance components in C. scarabaeoides and explore the possibility of transferring one or more of those factors to cultivated pigeonpea. A detached leaf assay was used to assess antibiosis and antixenosis resistance mechanisms in C. scarabaeoides. Artificial diet supplemented with lyophilised leaf powder was employed to investigate the antibiosis resistance mechanism. Data on larval mortality and larval and pupal weights were collected. Time taken for neonate larvae to pupate and for pupae to develop to the moth stage were determined through daily observations. Preliminary results showed that H. armigera larval weight was significantly reduced and larval development stages were prolonged when reared on different accessions of C. scarabaeoides as compared to the susceptible check, C. cajan (ICPL 87). Interspecific hybridization was carried out between C. scarabaeoides and a commercial pigeonpea variety. Results from insect challenge assays and trichome identification indicate that the hybrids have similar levels of insect resistance to their wild parent. Proteomic analysis is being used to identify possible antibiosis factors. Full article

Neoadjuvant chemoradiation (nCRT) is an established procedure in stage union internationale contre le cancer (UICC) II/III rectal carcinomas. Around 53% of the tumours present with good tumor regression after nCRT, and 8%–15% are complete responders. Reliable selection markers would allow the identification of poor or non-responders prior to therapy. Tumor biopsies were harvested from 20 patients with rectal carcinomas, and stored in liquid nitrogen prior to therapy after obtaining patients’ informed consent (Erlangen-No.3784). Patients received standardized nCRT with 5-Fluoruracil (nCRT I) or 5-Fluoruracil ± Oxaliplatin (nCRT II) according to the CAO/ARO/AIO-04 protocol. After surgery, regression grading (Dworak) of the tumors was performed during histopathological examination of the specimens. Tumors were classified as poor (Dworak 1 + 2) or good (Dworak 3 + 4) responders. Laser capture microdissection (LCM) for tumor enrichment was performed on preoperative biopsies. Differences in expressed proteins between poor and good responders to nCRT I and II were identified by proteomic analysis (Isotope Coded Protein Label, ICPL™) and selected markers were validated by immunohistochemistry. Tumors of 10 patients were classified as histopathologically poor (Dworak 1 or 2) and the other 10 tumor samples as histopathologically good (Dworak 3 or 4) responders to nCRT after surgery. Sufficient material in good quality was harvested for ICPL analysis by LCM from all biopsies. We identified 140 differentially regulated proteins regarding the selection criteria and the response to nCRT. Fourteen of these proteins were synchronously up-regulated at least 1.5-fold after nCRT I or nCRT II (e.g., FLNB, TKT, PKM2, SERINB1, IGHG2). Thirty-five proteins showed a complete reciprocal regulation (up or down) after nCRT I or nCRT II and the rest was regulated either according to nCRT I or II. The protein expression of regulated proteins such as PLEC1, TKT, HADHA and TAGLN was validated successfully by immunohistochemistry. ICPL is a valid method to identify differentially expressed proteins in rectal carcinoma tissue between poor vs. good responders to nCRT. The identified protein markers may act as selection criteria for nCRT in the future, but our preliminary findings must be reproduced and validated in a prospective cohort. Full article