Symbiotic associations between legumes and rhizobia usually commence with the perception of bacterial lipochitooligosaccharides, known as Nod factors (NF), which triggers rapid cellular and molecular responses in host plants. We report here deep untargeted tandem mass spectrometry-based measurements of rapid NF-induced changes in the phosphorylation status of 13,506 phosphosites in 7739 proteins from the model legume Medicago truncatula. To place these phosphorylation changes within a biological context, quantitative phosphoproteomic and RNA measurements in wild-type plants were compared with those observed in mutants, one defective in NF perception (nfp) and one defective in downstream signal transduction events (dmi3). Our study quantified the early phosphorylation and transcription dynamics that are specifically associated with NF-signaling, confirmed a dmi3-mediated feedback loop in the pathway, and suggested "cryptic" NF-signaling pathways, some of them being also involved in the response to symbiotic arbuscular mycorrhizal fungi. Legumes have the ability to form a very efficient symbiotic association with rhizobia to meet their nitrogen demand. This results in root nodule formation, inside which the rhizobia can fix atmospheric nitrogen efficiently and transfer it to the plants, in exchange for a carbon source. This interaction is often characterized by a high level of host specificity and generally requires an exchange of diffusible signals between legumes and rhizobia. Flavonoids and isoflavonoids present in the legume root exudates induce the expression of nod genes in rhizobia, and are responsible for the production and secretion of bacterial lipochitooligosaccharides (LCOs), known as Nod factors (NF) 1 (1, 2). NF are generally required for rhizobial infection and nodule development. Mere application of purified NF at low concentrations (10 Ϫ8 to 10 Ϫ12 M) is sufficient to trigger responses in host plants similar to those elicited by the rhizobia themselves (2, 3). Responses are elicited in root cells within a few seconds to minutes after NF application and include changes in ion fluxes across the plasma membrane, as well as accumulation of reactive oxygen species (4, 5). After 15-20 min, oscillations of the nuclear and perinuclear calcium concentration (calcium spiking) are initiated and trigger the expression of early nodulin genes (3). Within the first hour, legume root hairs undergo a cytoplasmic disorganization ,which leads to a transient swelling (6), followed by root hair deformations (7).Forward and reverse genetic approaches, in the model legumes Medicago truncatula (Medicago) and Lotus japonicus (Lotus), have identified several components controlling these events (Fig. 1). NF are perceived with high specificity by LysM receptor-like kinases residing on the plasma membrane. These kinases include nod factor perception (NFP), an essential component of a signaling receptor necessary for early responses to NF and rhizobial infection (8, 9). Mutants in NFP are affected in all known cellular respons...

This paper presents ultrasonic assisted friction stir welding (UaFSW), which is suggested to improve the weld quality and efficiency as a hybrid welding system. Ultrasonic-assisted processes have been coupled with tooling in various manufacturing processes to enhance the performance of conventional machining and bonding processes. For successful and effective implementation of the UaFSW, we must first consider how to integrate ultrasonics into the friction stir welding equipment. To solve this problem, we designed an ultrasonic horn to vibrate the FSW tool and transmit ultrasonic energy into the workpiece. Using a numerical modal and harmonic analysis, we fabricated and analyzed the ultrasonic horn under specific design considerations. Force was measured and compared during ultrasonic assisted and conventional friction stir welding. The mechanical properties of the workpieces were also investigated.

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Data storage devices are getting "smarter." Smart Flash storage devices (a.k.a. "Smart SSD") are on the horizon and will package CPU processing and DRAM storage inside a Smart SSD, and make that available to run user programs inside a Smart SSD. The focus of this paper is on exploring the opportunities and challenges associated with exploiting this functionality of Smart SSDs for relational analytic query processing. We have implemented an initial prototype of Microsoft SQL Server running on a Samsung Smart SSD. Our results demonstrate that significant performance and energy gains can be achieved by pushing selected query processing components inside the Smart SSDs. We also identify various changes that SSD device manufacturers can make to increase the benefits of using Smart SSDs for data processing applications, and also suggest possible research opportunities for the database community.

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This article outlines the current state of and recent developments in the use of corpora for language assessment and considers future directions with a special focus on computational methodology. Because corpora began to make inroads into language assessment in the 1990s, test developers have increasingly used them as a reference resource to become well versed in terms of the linguistic characteristics of expert and novice speakers' usage and identify the test construct. In regard to developing and validating language tests, large representative corpora, learner corpora, and specialized corpora have been actively used, as these corpora have made it possible to systematically compare the linguistic features associated with expert users with those found in learner language. Recent advances in computational approaches to assessment can facilitate this comparison to a great extent using technologies in automated essay scoring and learner language analysis. As an emerging area in the field of language assessment, corpus-based research should extend to less explored areas including compilation and longitudinal analysis of developmental corpora, fine-grained microanalysis of learner's development, and assessment attuned to individual learners who use different linguistic varieties. INTRODUCTIONThis article outlines the current state of and recent developments in the use of corpora for language assessment and considers future directions with a special focus on computational approaches to assessment. A corpus is a principled collection of language materials, spoken or written, compiled into an electronic database for the purpose of linguistic analysis (Biber, Conrad, & Reppen, 1998;Sinclair, 2004). Early discussions on the use of corpora for the purpose of assessing language use dates back to the mid-1990s when the potential of corpora for assessment was first recognized (e.g., Alderson, 1996). Since then, corpora have been increasingly used for large-scale standardized tests as well as for more holistic and developmental assessments. The present article has two related purposes: (a) to review the use of corpora in language assessment and (b) the potential contribution of corpora to language assessment, which include exploratory endeavors drawing on longitudinal, qualitative, and computational techniques. In the following sections, this article offers a survey of related research areas that are beginning to make a mark on the field and computational approaches to assessment drawing on natural language processing (NLP) technology.Correspondence should be sent to Kwanghyun Park,

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