159 research outputs found

    Landing Preference and Reproduction of Rhopalosiphum padi (Hemiptera: Aphididae) in the Laboratory on Three Maize, Potato, and Wheat Cultivars

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    The bird cherry-oat aphid Rhopalosiphum padi (L.) transmits the nonpersistent Potato virus Y (PVY) to seed potatoes. Planting a nonvirus host plant around the main crop can reduce PVY incidence, because aphids tend to land in high numbers at the edge of a field and the crop border acts as a virus sink. This study determined R. padi landing and settling preferences and reproductive rates on three cultivars each of maize and wheat compared with potato in the laboratory as a basis for identifying an attractive crop border plant. Aphids were reared on maize and wheat to control for bias due to previous experience. Irrespective of origin, alates preferred to land almost exclusively on maize and wheat rather than on potato cultivars in choice experiments. Aphid settling on the maize and wheat cultivars depended on aphid origin. In no-choice experiments, R. padi produced the highest number of offspring on the wheat cultivars, irrespective of origin. Plant nitrogen content and trichome density did not influence R. padi reproduction. The study demonstrates that host plant preference of aphids may vary between plant cultivars and can therefore influence the effectiveness of a crop border. The high landing rate but low reproduction suggest that maize cultivars '6Q-121' and '78-15B' could be suitable crop border plants in regions where R. padi is abundant. Before testing potential crop border plants in the field, cultivars should be screened using aphid landing, settling and reproduction as selection criteria

    Verification of the effectiveness of the Integrated Product Development paradigm for the development of sports equipment — A case study

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    AbstractThe sporting goods companies face significant challenges. To be successful on the market it is essential to follow a structured systematic product development process. A potential approach is the Integrated Product Development (IPD) paradigm. In this paper Insider Action Research (IAR) is used to verify the effectiveness of the IPD in a case study. It is shown that IPD is a potential development paradigm for the sporting goods industry to support a systematic development process for a successful product development in sports

    Lehrpersonen als Lerncoaches - Begleitstudie zur Implementation eines neuen Konzepts für die Lehrpersonenausbildung der Sekundarstufe II

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    Lerncoaching kann Lernprozesse bei Schülerinnen und Schülern fördern. In der Nordwestschweiz soll der Erwerb entsprechender Kompetenzen daher fester Bestandteil der Lehrpersonenausbildung für die Sekundarstufe II werden. Der Beitrag stellt ein neues Konzept vor, bei dem Studierende Lerncoaching in unterschiedlichen schulbasierten Settings durchführen und ihre Erfahrungen damit reflektieren. Zudem präsentiert er eine Begleitstudie zur Implementation des Konzepts. In der Studie berichteten die Studierenden in Fokusgruppeninterviews von ihren Lerncoachingerfahrungen. Das Konzept kann demnach bei Studierenden nicht nur Coachingkompetenzen fördern, sondern auch zur Sensibilisierung für die individuellen Lernvoraussetzungen der Schülerinnen und Schüler beitragen

    CXCR4 mediates leukemic cell migration and survival in the testicular microenvironment

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    The testis is the second most frequent extramedullary site of relapse in pediatric acute lymphoblastic leukemia (ALL). The mechanism for B-cell (B) ALL cell migration towards and survival within the testis remains elusive. Here, we identified CXCL12-CXCR4 as the leading signaling axis for B-ALL cell migration and survival in the testicular leukemic niche. We combined analysis of primary human ALL with a novel patient-derived xenograft (PDX)-ALL mouse model with testicular involvement. Prerequisites for leukemic cell infiltration in the testis were prepubertal age of the recipient mice, high surface expression of CXCR4 on PDX-ALL cells, and CXCL12 secretion from the testicular stroma. Analysis of primary pediatric patient samples revealed that CXCR4 was the only chemokine receptor being robustly expressed on B-ALL cells both at the time of diagnosis and relapse. In affected patient testes, leukemic cells localized within the interstitial space in close proximity to testicular macrophages. Mouse macrophages isolated from affected testes, in the PDX model, revealed a macrophage polarization towards a M2-like phenotype in the presence of ALL cells. Therapeutically, blockade of CXCR4-mediated functions using an anti-CXCR4 antibody treatment completely abolished testicular infiltration of PDX-ALL cells and strongly impaired the overall development of leukemia. Collectively, we identified a prepubertal condition together with high CXCR4 expression as factors affecting the leukemia permissive testicular microenvironment. We propose CXCR4 as a promising target for therapeutic prevention of testicular relapses in childhood B-ALL. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland

    Nanoproteomic analysis of ischemia-dependent changes in signaling protein phosphorylation in colorectal normal and cancer tissue

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    Additional file 1: Table S1. Clinical data for the 20 patients analyzed in the study. Presents patient clinical data including tumor stage and grade

    Specificity Protein 2 (Sp2) Is Essential for Mouse Development and Autonomous Proliferation of Mouse Embryonic Fibroblasts

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    BACKGROUND: The zinc finger protein Sp2 (specificity protein 2) is a member of the glutamine-rich Sp family of transcription factors. Despite its close similarity to Sp1, Sp3 and Sp4, Sp2 does not bind to DNA or activate transcription when expressed in mammalian cell lines. The expression pattern and the biological relevance of Sp2 in the mouse are unknown. METHODOLOGY/PRINCIPAL FINDINGS: Whole-mount in situ hybridization of mouse embryos between E7.5 and E9.5 revealed abundant expression in most embryonic and extra-embryonic tissues. In order to unravel the biological relevance of Sp2, we have targeted the Sp2 gene by a tri-loxP strategy. Constitutive Sp2null and conditional Sp2cko knockout alleles were obtained by crossings with appropriate Cre recombinase expressing mice. Constitutive disruption of the mouse Sp2 gene (Sp2null) resulted in severe growth retardation and lethality before E9.5. Mouse embryonic fibroblasts (MEFs) derived from Sp2null embryos at E9.5 failed to grow. Cre-mediated ablation of Sp2 in Sp2cko/cko MEFs obtained from E13.5 strongly impaired cell proliferation. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that Sp2 is essential for early mouse development and autonomous proliferation of MEFs in culture. Comparison of the Sp2 knockout phenotype with the phenotypes of Sp1, Sp3 and Sp4 knockout strains shows that, despite their structural similarity and evolutionary relationship, all four glutamine-rich members of the Sp family of transcription factors have distinct non-redundant functions in vivo

    Aster yellows phytoplasma in grapevines: identification of vectors in South Africa

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    Abstract Since the discovery of aster yellows phytoplasma on grapevine in South Africa in 2006, a concerted effort by various research groups to identify the vector(s) was co-ordinated by Winetech. This included qualitative and quantitative surveys for two years of leaf-and planthoppers occurring in vineyards in affected areas, testing specimens of leaf-and planthopper species for the presence of aster yellows phytoplasma with PCR, transmission experiments, and relating presence of leaf-and planthoppers in the field to the time of disease transmission. Twenty-eight leaf-and planthopper species/species groups have been recorded from vineyards in aster yellows-infected regions. The four most abundant species/species groups were Acia lineatifrons (Naudé), Austroagallia spp., Cicadulina spp. and Mgenia fuscovaria (Stål) (Hemiptera: Cicadellidae). Austroagallia spp. and M. fuscovaria repeatedly tested positive for the presence of AY. Results of transmission experiments and a field trial to determine leaf-/planthopper abundance in vineyards along with time of transmission in the field suggest that M. fuscovaria is a vector of aster yellows phytoplasma in South Africa. The concerted effort between industry and researchers allowed for fast identification of a potential vector of aster yellows phytoplasma in South Africa
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