1,863 research outputs found

    Reproduction of Soybean Cyst Nematode Populations on Field Pennycress, Henbit, and Purple Deadnettle Weed Hosts

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    Several weeds serve as alternative soybean cyst nematode (SCN) hosts. Still, the relative reproductive capacity of SCN HG types (Heterodera glycines type) on weed hosts relative to soybean is not well understood. This study examined the reproduction of three South Dakota endemic SCN populations—PSCN-1 (HG 0), PSCN-2 (HG 2.5.7), and PSCN-3 (HG 7)—on purple deadnettle, field pennycress, and henbit. The Relative Female Index (RFI) was calculated to compare SCN reproduction relative to the susceptible soybean check. Weed hosts, HG types, and their interactions influenced SCN reproduction. Henbit (RFI = 51.8) and purple deadnettle (RFI = 47.6) roots had a similar high RFI, whereas field pennycress (RFI = 23.04) had a lower RFI. Similarly, SCN populations PSCN-1 and PSCN-3 had a similar RFI of 36.9 and 37.2, respectively, while the population PSCN-2 had a higher RFI of 44.9 across weed hosts. A significant interaction between PSCN-1 and purple deadnettle was observed where the RFI was the highest (RFI = 53.3). These results indicate that these weed hosts support endemic SCN populations, and the HG type influenced reproductive success, further complicating SCN management. Hence, SCN presents a significant challenge in the new prospect of incorporating field pennycress host as an oilseed cover crop in the Midwest’s corn–soybean production system

    Learning layered motion segmentations of video

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    We present an unsupervised approach for learning a layered representation of a scene from a video for motion segmentation. Our method is applicable to any video containing piecewise parametric motion. The learnt model is a composition of layers, which consist of one or more segments. The shape of each segment is represented using a binary matte and its appearance is given by the rgb value for each point belonging to the matte. Included in the model are the effects of image projection, lighting, and motion blur. Furthermore, spatial continuity is explicitly modeled resulting in contiguous segments. Unlike previous approaches, our method does not use reference frame(s) for initialization. The two main contributions of our method are: (i) A novel algorithm for obtaining the initial estimate of the model by dividing the scene into rigidly moving components using efficient loopy belief propagation; and (ii) Refining the initial estimate using α β-swap and α-expansion algorithms, which guarantee a strong local minima. Results are presented on several classes of objects with different types of camera motion, e.g. videos of a human walking shot with static or translating cameras. We compare our method with the state of the art and demonstrate significant improvements. © 2007 Springer Science+Business Media, LLC

    Dermatofibrosarcoma Protuberans of Scalp With Cervical Lymph Node Metastasis

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    Dermatofibrosarcoma protuberans (DFSP) is an uncommon, slow growing and locally aggressive tumor of the skin with a high rate of recurrence even after supposedly wide excision. The reports of regional lymph node metastasis and distant metastasis are very rare. Because of the extreme rarity of these cases with metastasis, the experience with management of such patients is very limited. A case of recurrent DFSP of scalp, with metastasis to the regional lymph nodes, in a 17-year-old boy is reported here. This is the second case of DFSP involving scalp and 16th case of DFSP of all sites metastasizing to the regional lymph nodes reported in literature. The patient was treated with wide excision of the lesion and ipsilateral radical neck dissection (including excision of overlying involved skin)

    Applying the Dark Target Aerosol Algorithm with Advanced Himawari Imager Observations During the KORUS-AQ Field Campaign

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    For nearly 2 decades we have been quantitatively observing the Earth's aerosol system from space at one or two times of the day by applying the Dark Target family of algorithms to polar-orbiting satellite sensors, particularly MODIS and VIIRS. With the launch of the Advanced Himawari Imager (AHI) and the Advanced Baseline Imagers (ABIs) into geosynchronous orbits, we have the new ability to expand temporal coverage of the traditional aerosol optical depth (AOD) to resolve the diurnal signature of aerosol loading during daylight hours. The KoreanUnited States Air Quality (KORUS-AQ) campaign taking place in and around the Korean peninsula during MayJune 2016 initiated a special processing of full-disk AHI observations that allowed us to make a preliminary adoption of Dark Target aerosol algorithms to the wavelengths and resolutions of AHI. Here,we describe the adaptation and show retrieval results from AHI for this 2-month period. The AHI-retrieved AOD is collocated in time and space with existing AErosol RObotic NETwork stations across Asia and with collocated Terra and Aqua MODIS retrievals. The new AHI AOD product matches AERONET, and the standard MODIS product does as well, and the agreement between AHI and MODIS retrieved AOD is excellent, as can be expected by maintaining consistency in algorithm architecture and most algorithm assumptions. Furthermore, we show that the new product approximates the AERONET-observed diurnal signature. Examining the diurnal patterns of the new AHI AOD product we find specific areas over land where the diurnal signal is spatially cohesive. For example, in Bangladesh the AOD in-creases by 0.50 from morning to evening, and in northeast China the AOD decreases by 0.25. However, over open ocean the observed diurnal cycle is driven by two artifacts, one associated with solar zenith angles greater than 70t hat may be caused by a radiative transfer model that does not properly represent the spherical Earth and the other artifact associated with the fringes of the 40 degree glint angle mask. This opportunity during KORUS-AQ provides encouragement to move towards an operational Dark Target algorithm for AHI. Future work will need to re-examine masking including snow mask, reevaluate assumed aerosol models for geosynchronous geometry, address the artifacts over the ocean, and investigate size parameter retrieval from the over-ocean algorithm

    The moderating effects of transformational leadership and self-worth in the idiosyncratic deals - employee reactions relationship:A study of Indian hospitality industry

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    Purpose This paper examines the relationship between timing of negotiations and idiosyncratic deals (i-deals) through the moderating effects of core self-evaluations (CSE), and between i-deals and employee reactions through the moderating effects of transformational leadership behaviour (TLB) in the Indian hospitality industry. Design/methodology/approach A total of 275 employees working in 39 companies responded to a self-administered questionnaire. To test the research hypotheses, the methodology of structural equation models was used. Findings The results show that the relationship between before hiring negotiations and i-deals is stronger for those individuals who had low self-worth, due to countervailing forces created by their belief that they may not be eligible for i-deals. In contrast, the relationship between after hiring negotiations and i-deals is stronger for those who had high self-worth, due to their belief that they were entitled to i-deals. Additionally, the research highlights that the relationship between i-deals and employee reactions is stronger for those organisations, which are high on TLB. Research limitations/implications The data does not allow for investigating dynamic causal inferences, because they were collected using a questionnaire at a single point in time, and they were reported in retrospect, raising measurement concerns about recall bias. Practical implications From a managerial point of view, the findings of this study inform that in negotiating both employment conditions and work arrangements, organisations should try to achieve i-deals that are primarily flexibility focused, and that in increasing efficiency organisations should make the employees feel well supported in order to develop more confidence in deploying skills and abilities to address a more open view of their i-deals. Originality/value The study contributes to our understanding about the Indian hospitality industry by utilising the self-enhancement theory in examining whether individual differences moderate the relationship between the timing of negotiations and i-deals, and also by utilizing the social exchange theory to examine whether TLB moderates the relationship between i-deals and employee reactions

    Internationalization of emerging Indian multinationals:linkage, leverage and learning (LLL) perspective

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    The multi-polar world in which we now live and work demands re-examination and refinement of the traditional understanding of the internationalization strategies and competitive advantages of multinational firms by incorporating the characteristics of firms from emerging economies. Based on interviews in four Indian multinationals in different industry segments, we present the "voices" of Indian corporate leaders to provide preliminary evidence on the primary motives behind the internationalization process of emerging multinationals from the perspective of linkage, leverage and learning (LLL). We show how the case study organizations have evolved themselves to become credible global players by leveraging on their learning through targeted acquisitions in developed markets to acquire intangible assets and/or following global clients in search of new markets and competitive advantages

    Avapritinib: novel hope for patients with metastatic gist with PDGFRA exon 18 mutation

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    Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms of the gastrointestinal tract associated with high rates of malignant transformation. The activating mutations in platelet-derived growth factor receptor A (PDGFRA) have been linked to the development of GISTs, and up to approximately 10% of GIST cases involve mutations of this gene. Current treatment options for metastatic GIST are minimal, mainly trusting on tyrosine kinase inhibitors (TKIs) such as Imatinib, Sunitinib and Regorafenib. However, eventually, most patients develop resistance to TKIs, usually due to the acquisition of secondary mutations. Moreover, 5-6% of patients with unresectable of metastatic GIST have the primary PDGFRA D842V mutation, which makes it resistant to all approved treatment options. Avapritinib, a potent and selective TKI of KIT and PDGFRA activation loop mutants. The drug demonstrates anti-tumor activity by inhibiting the autophosphorylation of KIT D816V and PDGFRA D842V, thereby terminating the downstream signalling. The drug is available in oral formulation with a recommended dosage of 300 mg once daily. The onset of Avapritinib is fast, shows rapid absorption and linear pharmacokinetics. Most common adverse reactions seen are edema, fatigue, abdominal pain, and neurocognitive defects. Clinical trials for Avapritinib have been positive, and results suggest that the drug may be a new safe and effective option for metastatic GIST treatment. With Blueprint Medicines having already received US FDA approval in January 2020, Avapritinib may soon be an addition to the mounting armoury of drugs against metastatic GIST harbouring PDGFRA exon 18 mutation
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