CRISPR/Cas9-Mediated Generation of Pathogen-Resistant Tomato against Tomato Yellow Leaf Curl Virus and Powdery Mildew

Tomato is one of the major vegetable crops consumed worldwide. Tomato yellow leaf curl virus (TYLCV) and fungal Oidium sp. are devastating pathogens causing yellow leaf curl disease and powdery mildew. Such viral and fungal pathogens reduce tomato crop yields and cause substantial economic losses every year. Several commercial tomato varieties include Ty-5 (SlPelo) and Mildew resistance locus o 1 (SlMlo1) locus that carries the susceptibility (S-gene) factors for TYLCV and powdery mildew, respectively. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) is a valuable genome editing tool to develop disease-resistant crop varieties. In this regard, targeting susceptibility factors encoded by the host plant genome instead of the viral genome is a promising approach to achieve pathogen resistance without the need for stable inheritance of CRISPR components. In this study, the CRISPR/Cas9 system was employed to target the SlPelo and SlMlo1 for trait introgression in elite tomato cultivar BN-86 to confer host-mediated immunity against pathogens. SlPelo-knockout lines were successfully generated, carrying the biallelic indel mutations. The pathogen resistance assays in SlPelo mutant lines confirmed the suppressed accumulation of TYLCV and restricted the spread to non-inoculated plant parts. Generated knockout lines for the SlMlo1 showed complete resistance to powdery mildew fungus. Overall, our results demonstrate the efficiency of the CRISPR/Cas9 system to introduce targeted mutagenesis for the rapid development of pathogen-resistant varieties in tomato.     

Preprogramming Floating Time of Liquid Marble

Non-sticking droplets wrapped with fine hydrophobic particles, namely liquid marbles, can be transported both on solid and water pool without an undesired spill of the inner encapsulated liquid. While the stimuli-responsive release of the inner liquid in the target area is proposed, the time-programmed release is not yet achieved. Herein, the hydrophobicity of nanoclay is modulated via a catalyst-free 1,4-conjugate addition reaction to form liquid marbles. This nanoclay liquid marble is robust and stable in air but collapses on the liquid pool with a specific lifetime. The lifetime of the liquid marble can be modulated over seconds to hours scale depending on the selection of chemically modulated wettability of the nanoclay. The critical mechanism of lifetime modulation is responsible for controlling the coalescence kinetics between the water pool and inner liquid by nanoclays’ high diffusion length and chemically varied water spreading potential. The NC liquid marble's programmable lifetime to ‘time-bomb’ type drug release and cascade chemical reaction is applied—without requiring any external intervention.     

Effects of Post-Weld Heat Treatment on the Microstructure and Toughness of Flash Butt Welded High-Strength Low-Alloy Steel

Metallurgical and Materials Transactions A - Effect of post-weld heat treatment on the weld microstructure, texture, and its correlation to the toughness of flash butt welded joints were...     

Continuous cooling transformation diagrams applicable to the heat-affected zone of HSLA-80 and HSLA-100 steels

Continuous cooling transformation (CCT) diagrams for HSLA-80 and HSLA-100 steels pertaining to fusion welding with heat inputs of 10 to 40 kJ/cm, and peak temperatures of 1000 °C to 1400 °C have been developed. The corresponding nonlinear cooling profiles and related γ → α phase transformation start and finish temperatures for various peak temperature conditions have been taken into account. The martensite start (M _s ) temperature for each of the grades and ambient temperature microstructures were considered for mapping the CCT diagrams. The austenite condition and cooling rate are found to influence the phase transformation temperatures, transformation kinetics, and morphology of the transformed products. In the fine-grain heat-affected zone (FGHAZ) of HSLA-80 steel, the transformation during cooling begins at temperatures of 550 °C to 560 °C, and in the HSLA-100 steel at 470 °C to 490 °C. In comparison, the transformation temperature is lower by 120 °C and 30 °C in the coarse-grain heat-affected zone (CGHAZ) of HSLA-80 steel and HSLA-100 steel, respectively. At these temperatures, acicular ferrite (AF) and lath martensite (LM) phases are formed. While the FGHAZ contains a greater proportion of acicular ferrite, the CGHAZ has a higher volume fraction of LM. Cooling profiles from the same peak temperature influence the transformation kinetics with slower cooling rates producing a higher volume fraction of acicular ferrite at the expense of LM. The CCT diagrams produced can predict the microstructure of the entire HAZ and have overcome the limitations of the conventional CCT diagrams, primarily with respect to the CGHAZ.     

Guest Editors' Introduction: Security & Privacy

Security and privacy concerns touch on all aspects of pervasive computing, including hardware, operating systems, networks, databases, user interfaces, and applications. The seven articles selected for this special issue draw on ideas from many of these fields and provide a flavor of the kinds of security and privacy challenges and opportunities in pervasive computing. This article is part of a special issue on security and privacy.     

Pervasive Personal Computing in an Internet Suspend/Resume System

The Internet suspend/resume model of mobile computing cuts the tight binding between PC state and PC hardware. By layering a virtual machine on distributed storage, ISR lets the VM encapsulate execution and user customization state; distributed storage then transports that state across space and time. This article explores the implications of ISR for an infrastructure-based approach to mobile computing. It reports on experiences with three versions of ISR and describes work in progress toward the OpenISR version     

Cognitive deficits in docosahexaenoic acid-deficient rats.

This study investigated the influence of brain docosahexaenoic acid (DHA) deficiency on simple and complex olfactory-based learning and memory in 2nd generation (F2) adult male rats. Rats raised and maintained on either an n-3-adequate or an n-3-deficient diet were tested for acquisition of an olfactory learning set and an olfactory memory task, and for motivation to obtain a water reward. Despite a 76% decrease in brain DHA, n-3-deficient rats were able to acquire most simple 2-odor discrimination tasks but were deficient in the acquisition of a 20-problem olfactory learning set. This deficit could not be attributed to changes in sensory capacity but, instead, appeared to represent a deficit in higher order learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microstructures and properties of friction stir spot welded DP590 dual phase steel sheets

DP590 steel sheets were joined by friction stir spot welding using polycrystalline cubic boron nitride tool with an objective to produce bond diameters similar to conventional spot welding nuggets. A range of spindle rotation (400–2400 rev min^?1) and plunge speeds (0·03–3·8 mm s^?1) were exercised to attain defect free welds in 1·6 mm thick sheets. A bond diameter of 4t^1/2, alike minimum nugget diameter criteria for resistance spot welds, resulted in superior mechanical properties than conventional spot welds. The heat inputs corresponding to different welding parameters influenced the weld microstructure, including grain size, phases and their morphology. The bond diameter was higher for higher heat inputs. However, low heat input welds with weld time cycles ～4 s produced more refined microstructure and exhibited similar strengths even with reduced bond size. Plug type failure was associated with larger bond diameters (～7·1 mm), while interfacial failure was observed with smaller welds (～5·4 mm).     

Flood Plain Filling by a Monoclinal Flood Wave

Theoretical equations are derived to estimate the flood wave celerity and the volume of lateral flow leaving the main channel and entering the flood plain for a two-dimensional monoclinal wave. The equations are based on conservation of water mass assuming an idealized compound channel. The parameters that affect the lateral flow volume are the ratio of flood plain depth to the depth in the main channel at the peak discharge, the ratio of the flood plain width to the main channel width, and the ratio of the flood plain roughness to the main channel roughness. The percentage of flood plain volume filled up by lateral flow from the main channel increases as the width ratio decreases, the roughness ratio increases, or as the depth ratio decreases.