RNAi efficiency, systemic properties, and novel delivery methods for pest insect control : what we know so far

In recent years, the research on the potential of using RNA interference (RNAi) to suppress crop pests has made an outstanding growth. However, given the variability of RNAi efficiency that is observed in many insects, the development of novel approaches toward insect pest management using RNAi requires first to unravel factors behind the efficiency of dsRNA-mediated gene silencing. In this review, we explore essential implications and possibilities to increase RNAi efficiency by delivery of dsRNA through non-transformative methods. We discuss factors influencing the RNAi mechanism in insects and systemic properties of dsRNA. Finally, novel strategies to deliver dsRNA are discussed, including delivery by symbionts, plant viruses, trunk injections, root soaking, and transplastomic plants

Long wavelength structural anomalies in jammed systems

The structural properties of static, jammed packings of monodisperse spheres in the vicinity of the jamming transition are investigated using large-scale computer simulations. At small wavenumber $k$, we argue that the anomalous behavior in the static structure factor, $S(k) \sim k$, is consequential of an excess of low-frequency, collective excitations seen in the vibrational spectrum. This anomalous feature becomes more pronounced closest to the jamming transition, such that $S(0) \to 0$ at the transition point. We introduce an appropriate dispersion relation that accounts for these phenomena that leads us to relate these structural features to characteristic length scales associated with the low-frequency vibrational modes of these systems. When the particles are frictional, this anomalous behavior is suppressed providing yet more evidence that jamming transitions of frictional spheres lie at lower packing fractions that that for frictionless spheres. These results suggest that the mechanical properties of jammed and glassy media may therefore be inferred from measurements of both the static and dynamical structure factors.Comment: 8 pages, 6 figure captions. Completely revised version to appear in Phys. Rev.

key determinants of e-commerce usage and repurchase intention

Aparicio, M., Costa, C. J., & Moises, R. (2021). Gamification and reputation: key determinants of e-commerce usage and repurchase intention. Heliyon, 7(3), [e06383]. https://doi.org/10.1016/j.heliyon.2021.e06383Nowadays, companies know that keeping customers engaged is essential to increase their loyalty. The main goal of this study is to understand the impact of gamification and reputation on the intention of repurchase in e-commerce. Gamification corresponds to the regular usage of game elements in non-game context. This study purposes a theoretical model indicating the determinants of repurchase intention. Here we present an empirical study (survey collected data) within a real e-commerce usage context. Data were analysed with SEM/PLS method. Results indicate a positive impact of trust on the intention to use of e-commerce, on buy frequency and on repurchase intention. Ease of use, usefulness of e-commerce platforms affect intension to use. We verified the impact of reputation on trust, as well as the impact of gamification on the effective use of the e-commerce platforms. Results indicate that gamified e-commerce websites determine usage and use positively influences repurchase intention in e-commerce context. Gamification, e-commerce, Repurchase intention, Information systems modelpublishersversionpublishe

A phase one AR/C system design

The Phase One AR&C System Design integrates an evolutionary design based on the legacy of previous mission successes, flight tested components from manned Rendezvous and Proximity Operations (RPO) space programs, and additional AR&C components validated using proven methods. The Phase One system has a modular, open architecture with the standardized interfaces proposed for Space Station Freedom system architecture

Clamp bending machine and annealed wire cutter for reinforced concrete columns

This study developed a reinforced steel rod bending machine for rods with diameters of up to 8 mm and annealed wire cutter for up to 5 kg for replacing manual intervention required to bend rods in reinforced concrete columns. This study aims to reduce the physical effort that could lead to occupational diseases, such as tenosynovitis, bursitis, muscle disorders. Clamp manufacturing possesses great risk for workers, who are exposed to injuries while using different cutting devices, such as grinders and electric saws. They also face potential problems such as muscular fatigue due to the nonergonomic and repetitive work positions. The proposed machine features a mechanical dragging and bending systems and manual shears. Additionally, the proposed machine has been designed theoretically and its effectiveness has been assessed through simulations conducted using the SolidWorks CAD software. A bending machine prototype for producing clamps is developed and its machine productivity is measured. Using this machine, approximately 300 clamps can be bent per hour without possessing any risk to the worker

Shipbuilding 4.0 Index Approaching Supply Chain

The shipbuilding industry shows a special interest in adapting to the changes proposed by the industry 4.0. This article bets on the development of an index that indicates the current situation considering that supply chain is a key factor in any type of change, and at the same time it serves as a control tool in the implementation of improvements. The proposed indices provide a first definition of the paradigm or paradigms that best fit the supply chain in order to improve its sustainability and a second definition, regarding the key enabling technologies for Industry 4.0. The values obtained put shipbuilding on the road to industry 4.0 while suggesting categorized planning of technologies

Influence of 1-Methylcyclopropene Treatment on Postharvest Quality of Four Scab (Venturia inaequalis)-Resistant Apple Cultivars

Scab (Venturia inaequalis) is a very serious disease for apples causing up to 80% of loss in yield but there are only a few studies on postharvest quality of scab-resistant cultivars. In this study we evaluated the effect of 1-methylcyclopropene (1-MCP) on fruit quality, total phenolic content, and antioxidant capacity after storage of four scab-resistant cultivars and compared to a standard cultivar, “Golden Delicious.” In general, ethylene production and respiration rates significantly differed among cultivars, between control and 1-MCP-treated fruits, and between storage duration regimes. 1-MCP treatment retarded fruit softening and lowered juice pH but storage effect on soluble solids and acidity depended on cultivar and 1-MCP treatment. Total phenolic content was significantly affected by storage duration and 1-MCP treatment. Antioxidant capacity of the four scab-resistant cultivars was either similar to or significantly higher than that of “Golden Delicious” with the 1-MCP-treated fruits having significantly higher antioxidant capacity than the nontreated fruits after storage. Our results clearly show that the quality of four scab-resistant cultivars was comparable to that of “Golden Delicious” and 1-MCP effect differed among cultivars. These differences need to be considered in developing storage regime to minimize quality deterioration during long-term storage