6,787 research outputs found
Salicylic acid receptors activate jasmonic acid signalling through a non-canonical pathway to promote effector-triggered immunity.
It is an apparent conundrum how plants evolved effector-triggered immunity (ETI), involving programmed cell death (PCD), as a major defence mechanism against biotrophic pathogens, because ETI-associated PCD could leave them vulnerable to necrotrophic pathogens that thrive on dead host cells. Interestingly, during ETI, the normally antagonistic defence hormones, salicylic acid (SA) and jasmonic acid (JA) associated with defence against biotrophs and necrotrophs respectively, both accumulate to high levels. In this study, we made the surprising finding that JA is a positive regulator of RPS2-mediated ETI. Early induction of JA-responsive genes and de novo JA synthesis following SA accumulation is activated through the SA receptors NPR3 and NPR4, instead of the JA receptor COI1. We provide evidence that NPR3 and NPR4 may mediate this effect by promoting degradation of the JA transcriptional repressor JAZs. This unique interplay between SA and JA offers a possible explanation of how plants can mount defence against a biotrophic pathogen without becoming vulnerable to necrotrophic pathogens
Outward FDI: National and Regional Policy Implications for Technology Innovation
A significant contributor to China’s growth over the last 20 years is the ‘go-out’ policy, that is, for domestic firms to invest in international firms and has seen it develop a foundation of high technology industries and world leading research. We find that across China, the ‘go-out’ policy needs support from provincial governments in terms of human capital, basic research and infrastructure to ensure that imported technology is effectively absorbed into the local economies. This means a national strategy needs local tuning to the needs of the region. Across all provinces, we find that during the period 2006 to 2016 outward foreign direct investment (OFDI) spillovers have a significant and positive impact on technology innovation as measured by patents. OFDI alone is insufficient and may crowd out local research and development (R&D), as such, those provinces need to get to a threshold of absorptive capacity in basic, applied research supported by human capital and R&D capital stock. When the gap between a province and the rest of the world is large then OFDI could have a crowding out effect without the province supporting basic research. We test for structural changes across all provinces by classifying them by either having large or small frontier technology, the proxy for absorptive capacity. We find that the role of human capital and basic research changes substantially between small gap and large gap provinces indicating that regional policy makers need to ensure that policies are fine tuned to the stage of development in a particular region and will change over time. OFDI effects are diminished as the provinces gap reduces and this may be particularly timely in the face of China being subject to increasing trade and investment pressure internationally
An end-to-end review of gaze estimation and its interactive applications on handheld mobile devices
In recent years we have witnessed an increasing number of interactive systems on handheld mobile devices which utilise gaze as a single or complementary interaction modality. This trend is driven by the enhanced computational power of these devices, higher resolution and capacity of their cameras, and improved gaze estimation accuracy obtained from advanced machine learning techniques, especially in deep learning. As the literature is fast progressing, there is a pressing need to review the state of the art, delineate the boundary, and identify the key research challenges and opportunities in gaze estimation and interaction. This paper aims to serve this purpose by presenting an end-to-end holistic view in this area, from gaze capturing sensors, to gaze estimation workflows, to deep learning techniques, and to gaze interactive applications.PostprintPeer reviewe
Effect of adenine sulfate, benzylaminopurine and media forms on propagation of banana (Musa AAA) cv. Gros Michel and plantain (Musa ABB) cv. Cardaba
This study was initiated to test the effect of adenine sulfate, benzylaminopurine (BAP) and media forms on in vitro morphogenesis of banana cv. Gros Michel and plantain cv; Cardaba during the period January, 2001 to May, 2002. The number of plantlets per explant increased significantly on both cultivars cultured on liquid prop- agation medium with filter paper bridge compared to other forms of media. However, the percentage of explants with shoot regeneration was comparable on all treatments. Comparable percentage of shoot tip explants with shoots were induced from cv. Gros Michel culture on different concentrations of adenine sulfate and the propagation medium which represented the control. However, the number of shoots per explant decreased significantly except that on 100mg/l which was comparable with the propagation medium. The percentage of explants with roots and number of roots per explant increased significantly on cv. Gros Michel on adenine sulfate compared with the propagation medium. The different concentrations of adenine sulfate induced comparable percentage of explants with roots and shoots on cv. Cardaba. However, the number of explants with shoots induced on Cardaba decreased significantly when adenine sulfate was added to the propagation medium and the number of roots per explant increased significantly compared with the control. Benzylaminopurine induced similar percentages of explants with shoot regeneration on cvs. Gros Michel and Cardaba. Significantly higher number of shoots per explants of banana cv. Gros Michel was induced on mediun supplemented with BAP at 5 or 7.5 mg/l. However, the highest nurnber of shoots regenerated from plantain cv. Cardaba was induced
by higher concentrations of BAP (7.5 and 10.0 mg/l). There were genotypic differences in the response of the two cultivars to BAP.
 
Topological vacuum fluctuation and Dvoretzky‘s theorem – Mathematical proofs in the context of the dark energy density of the universe
Starting from the initial triality of physics, namely mathematical philosophy, transfinite set theory and number theory we drive the inevitability of a topological quantum vacuum fluctuation of spacetime resulting in the fundamental reality of pair creation and annihilation. Subsequently we give a simple but strong mathematical proof of Dvoretzky‘s marvellous theorem on measure concentration, thus making dark energy and accelerated cosmic expansion not only an astrophysical measurement and observational reality, but also a plausible topological-geometrical fact of a pointless Cantorian actual universe akin to the Penrose fractal tiling space. This space is described accurately via the von Neumann-Conne noncommutative geometry using their golden mean dimensional function and the corresponding bijection of E-infinity theory. The said theory was developed by the authors of the present paper and their group and is based on and starts from the pioneering efforts of the Canadian physicist G. Ord and the French astrophysicist L. Nottale
Head and Neck Cancer Primary Tumor Auto Segmentation Using Model Ensembling of Deep Learning in PET/CT Images
Auto-segmentation of primary tumors in oropharyngeal cancer using PET/CT images is an unmet need that has the potential to improve radiation oncology workflows. In this study, we develop a series of deep learning models based on a 3D Residual Unet (ResUnet) architecture that can segment oropharyngeal tumors with high performance as demonstrated through internal and external validation of large-scale datasets (training size = 224 patients, testing size = 101 patients) as part of the 2021 HECKTOR Challenge. Specifically, we leverage ResUNet models with either 256 or 512 bottleneck layer channels that demonstrate internal validation (10-fold cross-validation) mean Dice similarity coefficient (DSC) up to 0.771 and median 95% Hausdorff distance (95% HD) as low as 2.919 mm. We employ label fusion ensemble approaches, including Simultaneous Truth and Performance Level Estimation (STAPLE) and a voxel-level threshold approach based on majority voting (AVERAGE), to generate consensus segmentations on the test data by combining the segmentations produced through different trained cross-validation models. We demonstrate that our best performing ensembling approach (256 channels AVERAGE) achieves a mean DSC of 0.770 and median 95% HD of 3.143 mm through independent external validation on the test set. Our DSC and 95% HD test results are within 0.01 and 0.06 mm of the top ranked model in the competition, respectively. Concordance of internal and external validation results suggests our models are robust and can generalize well to unseen PET/CT data. We advocate that ResUNet models coupled to label fusion ensembling approaches are promising candidates for PET/CT oropharyngeal primary tumors auto-segmentation. Future investigations should target the ideal combination of channel combinations and label fusion strategies to maximize segmentation performance.</p
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