The plant immune response is a complex process involving transcriptional and posttranscriptional regulation of gene expression. Responses to plant immunity are initiated upon the perception of pathogen-associated molecular patterns, including peptide fragment of bacterial flagellin (flg22) or translation elongation factor Tu (elf18). Here, we identify an long-noncoding RNA, designated ELF18-INDUCED LONG-NONCODING RNA1 (ELENA1), as a factor enhancing resistance against pv DC3000. ELENA1 knockdown plants show decreased expression of () and the plants are susceptible to pathogens. By contrast, plants overexpressing ELENA1 show elevated expression after elf18 treatment and display a pathogen resistance phenotype. RNA-sequencing analysis of ELENA1-overexpressing plants after elf18 treatment confirms increased expression of defense-related genes compared with the wild type. ELENA1 directly interacts with Mediator subunit 19a (MED19a) and affects enrichment of MED19a on the promoter. These results show that MED19a regulates expression through ELENA1. Our findings uncover an additional layer of complexity, implicating long-noncoding RNAs in the transcriptional regulation of plant innate immunity.

[1] The influence of geomagnetic activity on middle-and low-latitude thermospheric winds and ionospheric electric fields is investigated using model results from the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model. Model runs are made for different levels of geomagnetic activity. Model results show that the equatorward ionospheric currents produced by disturbance winds develop positive charge accumulation at low latitudes that maximizes in the premidnight sector. The local time of maximum electric potential perturbation depends significantly on universal time so that the local time of reversal of the equatorial zonal perturbation electric field varies with longitude by 2 to 3 hours, depending on the intensity of geomagnetic activity. The westward perturbation electric field in the postsunset period indicates that stronger geomagnetic activity will produce a lower driven height of the evening F region. After geomagnetic activity ceases, model results show that the zonal disturbance winds can last for many days in the postrecovery period, while the meridional disturbance winds decay more rapidly. The long-lasting zonal winds, through the Pedersen currents they drive, help maintain meridional disturbance potential drops that decay much more slowly than the zonal disturbance potential drops after the activity ceases.

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[1] The effect of a disturbance dynamo during geomagnetic activity on the equatorial ionospheric electric fields is investigated, using model results from the NACR/TIEGCM (National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model). Model runs are made for different time-lengths of geomagnetic activity, for different seasons, and for different solar activities to investigate how and where the maximum electric potential forms. Model results show that the maximum electric potential is located at around 300 km altitude and at local time after the pre-reversal enhancement at equinox for high solar activity. For the case at solstice, without pre-reversal enhancement, the location moves to around 110 km altitude and to the local time close to midnight. Giving various parameters in the model runs to simulate different background conditions, many important output quantities are used to study the distributions of perturbed electric potential at the geomagnetic equator. Model investigation indicates that normal quiet time electrodynamics, at different seasons with different solar activities, significantly affect the distribution of perturbed current density associated with geomagnetic activity. Furthermore, model results also reveal that significant perturbed zonal electric fields tend to build up six hours after the onset of geomagnetic activity, except at regions close to sunset and sunrise, and the perturbed vertical electric fields increase with the time length of geomagnetic activity.Citation: Huang, C. M., and M. Q. Chen (2008), Formation of maximum electric potential at the geomagnetic equator by the disturbance dynamo,

The problem of choosing a good parameter setting for a better generalization performance in a learning task is the so-called model selection. A nested uniform design (UD) methodology is proposed for efficient, robust and automatic model selection for support vector machines (SVMs). The proposed method is applied to select the candidate set of parameter combinations and carry out a k-fold cross-validation to evaluate the generalization performance of each parameter combination. In contrast to conventional exhaustive grid search, this method can be treated as a deterministic analogue of random search. It can dramatically cut down the number of parameter trials and also provide the flexibility to adjust the candidate set size under computational time constraint. The key theoretic advantage of the UD model selection over the grid search is that the UD points are "far more uniform" and "far more space filling" than lattice grid points. The better uniformity and space-filling phenomena make the UD selection scheme more efficient by avoiding wasteful function evaluations of close-by patterns. The proposed method is evaluated on different learning tasks, different datasets as well as different SVM algorithms.

[1] Perturbed electric fields in the Earth's ionosphere during storm activities may result from the penetration electric fields from high latitudes and/or from the dynamo mechanism driven by the neutral disturbances, depending on the storm phases. In general, the identification of the penetration electric fields is easier than that of the dynamo electric fields. At times, the latter becomes unperceivable or difficult to identify. This is an interesting problem that motivates a model study to investigate the possible reasons. Model runs made from the National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model will be presented. Theoretical studies of ionospheric responses to geomagnetic storms with model simulations indicate that the intensities of disturbance dynamo electric fields are highly dependent on various parameters, for example, solar activities, seasonal effects and universal times, etc. When geomagnetic activities commence at 01~07 UT in summer solstices with low solar fluxes, the disturbance dynamo electric fields become very small. Compared with the general daily variations, they seem to be unperceivable. This phenomenon can be explained by the model results, which show that the positive charge accumulation at low latitudes will be weakened when the equatorward neutral disturbances penetrate the opposite hemisphere in the storm time. For other cases, the magnitudes of the dynamo electric fields are relatively larger under the same geomagnetic activities.

Due to reliance upon geometric assumptions and foreshortening issues, the traditionally utilized transthoracic two-dimensional echocardiography (2DTTE) has shown limitations in assessing left ventricular (LV) volume, mass, and function. Cardiac magnetic resonance imaging (MRI) has shown potential in accurately defining these LV characteristics. Recently, the emergence of live/real time three-dimensional (3D) TTE has demonstrated incremental value over 2DTTE and comparable value with MRI in assessing LV parameters. Here we report 58 consecutive patients with diverse cardiac disorders and clinical characteristics, referred for clinical MRI studies, who were evaluated by cardiac MRI and 3DTTE. Our results show good correlation between the two modalities.

We demonstrate for the first time that augmented miR-150 expression with depressed SOCS1 expression in CD14(+) cells are associated with the pathogenesis of DHF.