277 research outputs found

    Olfactory Cues from Plants Infected by Powdery Mildew Guide Foraging by a Mycophagous Ladybird Beetle

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    Powdery mildews (Erysiphales) are economically important plant pathogens that attack many agricultural crops. Conventional management strategies involving fungicide application face challenges, including the evolution of resistance and concerns over impacts on non-target organisms, that call for investigation of more sustainable alternatives. Mycophagous ladybird beetles (Coleoptera: Coccinellidae) feed on powdery mildew and have considerable potential as biological control agents; however, the foraging ecology and behavior of these beetles is not well understood. Here we document the olfactory cues presented by squash plants (Cucurbita moschata) infected by powdery mildew (Podosphaera sp.) and the behavioral responses of twenty-spotted ladybird beetles (Psyllobora vigintimaculata) to these cues. Volatile analyses through gas chromatography revealed a number of volatile compounds characteristic of infected plants, including 3-octanol and its analogues 1-octen-3-ol and 3-octanone. These compounds are typical “moldy” odorants previously reported in volatiles collected from other fungi. In addition, infected plants exhibited elevated emissions of several compounds also observed in collections from healthy leaves, including linalool and benzyl alcohol, which are reported to have anti-fungal properties. In Y-tube choice assays, P. vigintimaculata beetles displayed a significant preference for the odors of infected plants compared to those of healthy plants. Moreover, beetles exhibited strong attraction to one individual compound, 1-octen-3-ol, which was the most abundant of the characteristic fungal compounds identified. These results enhance our understanding of the olfactory cues that guide foraging by mycophagous insects and may facilitate the development of integrated disease-management strategies informed by an understanding of underlying ecological mechanisms

    Forprófun á íslenskri útgáfu Sjálfsmatskvarða Becks fyrir börn og unglinga

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    Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenGerð var forprófun á Sjálfsmatskvörðum Becks fyrir börn á aldrinum 7-14 ára til þess að athuga próffræðilega eiginleika íslenskrar útgáfu af kvörðunum. Þátttakendur voru 293 úr 12 grunnskólum í Reykjavík. Próffræðilegir eiginleikar reyndust sambærilegir við erlendar rannsóknir. Innri áreiðanleiki var hár og fylgni atriða við heildarskor hvers kvarða viðunandi. Samleitni kvarða var athugað með þáttagreiningu og niðurstöður sýndu að þunglyndi, kvíði og hegðunarvandi voru einsleitir kvarðar en atriði sjálfsmyndar og reiði mynduðu tvo þætti. Gerð var þáttagreining á öllum 100 atriðum kvarðanna. Niðurstöður sýndu þrjá þætti sem skýrðu 38,6% dreifingar. Fyrsti þáttur samanstóð af þunglyndi, reiði og kvíða. Á annan þátt lögðust þrjú atriði reiði og 18 atriði hegðunarvanda og á þriðja þátt lögðust 18 atriði sjálfsmyndar. Há fylgni reyndist vera milli kvíða, þunglyndis og reiði en það er sambærilegt niðurstöðum erlendra rannsókna. Réttmæti kvarðanna var athugað með þremur spurningum um líðan í skóla og stríðni. Spurning um líðan í frímínútum hafði hæstu fylgni við þunglyndi sem bendir til þess að nemendur sem sýna þunglyndiseinkenni líður frekar illa í frímínútum. Spurning um líðan í kennslustundum hafði hæstu fylgni við hegðunarvanda og reiði og loks var hæst fylgni milli hegðunarvanda og stríðni. Enginn kynja- eða aldursmunur kom fram á kvörðum fyrir þunglyndi, reiði og kvíða. Hins vegar var meðaltal eldri hóps og drengja hærra á kvarða fyrir hegðunarvanda en hjá yngri hóp og stúlkum. Meðaltal á sjálfsmyndarkvarða var lægra í hópi eldri þáttakenda og meiri munur var á milli yngri og eldri stúlkna sem bendir til að sjálfsmynd verði neikvæðari á unglingsárum og sérstaklega hjá stúlkum. Próffræðilegir eiginleikar reyndust í megindráttum góðir en safna þarf meiri gögnum um áreiðanleika og réttmæti kvarðanna áður en hægt er að mæla með almennri notkun þeirra hér á landi.A pilot study of the Beck Youth Inventories (BYI) for children 7-14 years was undertaken to evaluate the psychometric properties of the Icelandic version. Participants were 293 from 12 elementary schools in Reykjavík. Psychometric properties revealed similar findings as other studies abroad have revealed. The internal consistency reliability was high and item total correlation acceptable. A principal axis factor analysis was conducted to evaluate the homogeneity of the BYI. Depression, anxiety and disruptive behavior were unidimensional but self-concept and anger revealed two factors. Additionally a principal axis factor analysis of all items of the inventories indicated three factors explaining 38,6% of variance. Items of depression, anxiety and anger loaded on the first factor. Disruptive behavior and 3 items of anger loaded on the second factor. Items of self-concept loaded on the third factor. Depression, anxiety and anger correlated highly, consistent with studies abroad and the factor analysis results. The scales´ validity was evaluated by three items assesing emotional well being in school and teasing other pupils. The highest correlation was between emotional well being in school breaks and depression, emotional well being in classrooms and disruptive behavior and anger, and between teasing other pupils and disruptive behavior. No significant age and gender differences were found on depression, anxiety and anger. Mean score for boys was higher than for girls on disruptive behavior and older students scored higher than younger students. Older students´ mean score was lower than younger students´ mean on self-concept and this difference was greater for girls than boys. Psychometric properties were good, but additonal studies need to be undertaken on the scales´ reliability and validity before we can recommend general use of the scales for clinical purposes in Iceland

    Variation in Courtship Ultrasounds of Three Ostrinia Moths with Different Sex Pheromones

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    Moths use ultrasounds as well as pheromones for sexual communication. In closely related moth species, variations in ultrasounds and pheromones are likely to profoundly affect mate recognition, reproductive isolation, and speciation. The European corn borer, Ostrinia nubilalis, and its Asian congeners, Ostrinia furnacalis and Ostrinia scapulalis, exhibit within-species and between-species variation in their pheromone communication. Recently, we reported ultrasound communication in O. furnacalis; however, variations in ultrasounds in the three congeners have not been addressed to date. Here we investigated features of ultrasound production and hearing in O. nubilalis and O. scapulalis, and compared them with those of O. furnacalis. As in O. furnacalis, males of O. nubilalis and O. scapulalis produced ultrasounds during courtship by rubbing specialized scales on the wings against scales on the thorax. The covering of these scales with nail polish muffled the sounds and significantly reduced mating success in O. nubilalis, showing the importance of ultrasound signaling in mating. The ultrasounds produced by O. nubilalis and O. scapulalis were similar, consisting of long trains of pairs of pulses with a main energy at 40 kHz, but distinctly different from the ultrasound produced by O. furnacalis, consisting of groups of pulses peaking at 50 kHz and with substantially more energy up to 80 kHz. Despite overall similarities, temporal features and patterns of amplitude modulation differed significantly among the geographic populations of O. nubilalis and O. scapulalis, which differed in pheromone type. In contrast, no significant difference in hearing was found among the three species with regard to the most sensitive frequencies and hearing threshold levels. The patterns of variations in the songs and pheromones well reflected those of the phylogenetic relationships, implying that ultrasound and pheromone communications have diverged concordantly. Our results suggest that concordant evolution in sexual signals such as courtship ultrasounds and sex pheromones occurs in moths

    Therapeutic potential of clinical-grade human induced pluripotent stem cell-derived cardiac tissues

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    Objectives: To establish a protocol to prepare and transplant clinical-grade human induced pluripotent stem cell (hiPSC)-derived cardiac tissues (HiCTs) and to evaluate the therapeutic potential in an animal myocardial infarction (MI) model. Methods: We simultaneously differentiated clinical-grade hiPSCs into cardiovascular cell lineages with or without the administration of canonical Wnt inhibitors, generated 5- layer cell sheets with insertion of gelatin hydrogel microspheres (GHMs) (HiCTs), and transplanted them onto an athymic rat MI model. Cardiac function was evaluated by echocardiography and cardiac magnetic resonance imaging and compared with that in animals with sham and transplantation of 5-layer cell sheets without GHMs. Graft survival, ventricular remodeling, and neovascularization were evaluated histopathologically. Results: The administration of Wnt inhibitors significantly promoted cardiomyocyte (CM) (P < .0001) and vascular endothelial cell (EC) (P = .006) induction, which resulted in cellular components of 52.0 ± 6.1% CMs and 9.9 ± 3.0% ECs. Functional analyses revealed the significantly lowest left ventricular end-diastolic volume and highest ejection fraction in the HiCT group. Histopathologic evaluation revealed that the HiCT group had a significantly larger median engrafted area (4 weeks, GHM(-) vs HiCT: 0.4 [range, 0.2-0.7] mm² vs 2.2 [range, 1.8-3.1] mm²; P = .005; 12 weeks, 0 [range, 0-0.2] mm² vs 1.9 [range, 0.1-3.2] mm2; P = .026), accompanied by the smallest scar area and highest vascular density at the MI border zone. Conclusions: Transplantation of HiCTs generated from clinical-grade hiPSCs exhibited a prominent therapeutic potential in a rat MI model and may provide a promising therapeutic strategy in cardiac regenerative medicine

    Extracellular vesicles synchronize cellular phenotypes of differentiating cells

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    細胞外小胞が細胞の分化を同調させる現象の発見. 京都大学プレスリリース. 2021-10-01.Cells act in unison when next to each other. 京都大学プレスリリース. 2021-10-01.During embryonic development, cells differentiate in a coordinated manner, aligning their fate decisions and differentiation stages with those of surrounding cells. However, little is known about the mechanisms that regulate this synchrony. Here we show that cells in close proximity synchronize their differentiation stages and cellular phenotypes with each other via extracellular vesicle (EV)-mediated cellular communication. We previously established a mouse embryonic stem cell (ESC) line harbouring an inducible constitutively active protein kinase A (CA-PKA) gene and found that the ESCs rapidly differentiated into mesoderm after PKA activation. In the present study, we performed a co-culture of Control-ESCs and PKA-ESCs, finding that both ESC types rapidly differentiated in synchrony even when PKA was activated only in PKA-ESCs, a phenomenon we named ‘Phenotypic Synchrony of Cells (PSyC)’. We further demonstrated PSyC was mediated by EVs containing miR-132. PKA-ESC-derived EVs and miR-132-containing artificial nano-vesicles similarly enhanced mesoderm and cardiomyocyte differentiation in ESCs and ex vivo embryos, respectively. PSyC is a new form of cell-cell communication mediated by the EV regulation of neighbouring cells and could be broadly involved in tissue development and homeostasis

    TAT-dextran-mediated mitochondrial transfer enhances recovery from models of reperfusion injury in cultured cardiomyocytes

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    Acute myocardial infarction is a leading cause of death among single organ diseases. Despite successful reperfusion therapy, ischaemia reperfusion injury (IRI) can induce oxidative stress (OS), cardiomyocyte apoptosis, autophagy and release of inflammatory cytokines, resulting in increased infarct size. In IRI, mitochondrial dysfunction is a key factor, which involves the production of reactive oxygen species, activation of inflammatory signalling cascades or innate immune responses, and apoptosis. Therefore, intercellular mitochondrial transfer could be considered as a promising treatment strategy for ischaemic heart disease. However, low transfer efficiency is a challenge in clinical settings. We previously reported uptake of isolated exogenous mitochondria into cultured cells through co-incubation, mediated by macropinocytosis. Here, we report the use of transactivator of transcription dextran complexes (TAT-dextran) to enhance cellular uptake of exogenous mitochondria and improve the protective effect of mitochondrial replenishment in neonatal rat cardiomyocytes (NRCMs) against OS. TAT-dextran-modified mitochondria (TAT-Mito) showed a significantly higher level of cellular uptake. Mitochondrial transfer into NRCMs resulted in anti-apoptotic capability and prevented the suppression of oxidative phosphorylation in mitochondria after OS. Furthermore, TAT-Mito significantly reduced the apoptotic rates of cardiomyocytes after OS, compared to simple mitochondrial transfer. These results indicate the potential of mitochondrial replenishment therapy in OS-induced myocardial IRI

    Pregnancy-associated plasma protein Aを悪性胸膜中皮腫細胞の遊走能を促進する遺伝子として同定 : 治療標的としての可能性

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    Despite recent advances in treatment, malignant pleural mesothelioma (MPM) remains a deadly disease. Targeted therapy generated broad interests and is highly expected for the treatment of MPM, yet promising preclinical results have not been translated into substantial clinical benefits for the patients. In this study, we tried to identify the genes which play functional roles in cell migration as well as to test whether they can be used as novel targets for molecular targeted therapy for MPM in preclinical model. In our study, pregnancy-associated plasma protein A (PAPPA) was identified as a gene whose expression level is correlated with MPM cell migration by correlation analysis combining MPM cell migration ability and their gene expression profiles. Highly migratory cells were selected from MPM cell lines, MSTO-211H, NCI-H290 and EHMES-1 in vitro and up-regulation of PAPPA in these cells were confirmed. In vitro, PAPPA was demonstrated to stimulate the MPM cell migration via cleavage of insulin-like growth factor-binding protein-4 and subsequent release of IGF-1. Gene silencing of PAPPA in MPM cells led to reduced migration, invasion and proliferation. Furthermore, PAPPA shRNA transfected NCI-H290 when orthotopically inoculated into pleural cavity of severe combined immunodeficiency recipient mice, failed to develop tumors and produce bloody pleural effusion as control shRNA transfected cells did. Our study suggests that PAPPA plays a functional role in promoting MPM cell migration and it might serve as a potential therapeutic target for the treatment of MPM

    Local application of Usag-1 siRNA can promote tooth regeneration in Runx2-deficient mice

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    Runt-related transcription factor 2 (Runx2)-deficient mice can be used to model congenital tooth agenesis in humans. Conversely, uterine sensitization-associated gene-1 (Usag-1)-deficient mice exhibit supernumerary tooth formation. Arrested tooth formation can be restored by crossing both knockout-mouse strains; however, it remains unclear whether topical inhibition of Usag-1 expression can enable the recovery of tooth formation in Runx2-deficient mice. Here, we tested whether inhibiting the topical expression of Usag-1 can reverse arrested tooth formation after Runx2 abrogation. The results showed that local application of Usag-1 Stealth small interfering RNA (siRNA) promoted tooth development following Runx2 siRNA-induced agenesis. Additionally, renal capsule transplantation of siRNA-loaded cationized, gelatin-treated mouse mandibles confirmed that cationized gelatin can serve as an effective drug-delivery system. We then performed renal capsule transplantation of wild-type and Runx2-knockout (KO) mouse mandibles, treated with Usag-1 siRNA, revealing that hindered tooth formation was rescued by Usag-1 knockdown. Furthermore, topically applied Usag-1 siRNA partially rescued arrested tooth development in Runx2-KO mice, demonstrating its potential for regenerating teeth in Runx2-deficient mice. Our findings have implications for developing topical treatments for congenital tooth agenesis
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