786 research outputs found

    Insecticide effect of zeolites on the tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae)

    Get PDF
    (1) Background: The tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae) is a key tomato insect pest. At present, it is considered to be a serious threat in various countries in Europe, North Africa, and Middle East. The extensive use and the developed resistance of T. absoluta to spinosad causes some concern, which leads to the need for alternative products. (2) Materials and Methods: Several laboratory experiments were conducted to investigate the ovicidal properties of a zeolite particle film on T. absoluta. The toxicity of three different zeolites and six zeolite formulations to T. absoluta eggs and larvae was determined using different exposure methods. (3) Results: In general, the formulated zeolites yielded higher egg and larvae mortality values, especially when the zeolite particle film was residually applied. Notable differences in mortality rates from exposure to zeolites compared to other products, such as kaolin, its formulated product Surround, and the insecticide spinosad, were observed. Kaolin and Surround exhibited little or no effect for both application methods, while the hatch rate was reduced by 95% when spinosad was applied topically. Spinosad yielded egg and larvae mortality rates of 100% for both application methods. Additionally, increased oviposition activity was observed in adults exposed to the wettable powder (WP) formulations. These WP formulations increased egg deposition, while Surround and spinosad elicited a negative oviposition response. (4) Conclusions: It can be derived that the tested products, zeolites BEA (Beta polymorph A), FAU (Faujasite), LTA (Linde type A), and their formulations, had no real insecticidal activity against the eggs of T. absoluta. Nevertheless, egg exposure to zeolites seemed to affect the development process by weakening the first instar larvae and increasing their mortality. Subsequently, based on the choice test, no significant difference was observed between the number of eggs laid on the treated leaves and control leaves

    Analysis of walking with unilateral exoskeleton assistance compared to bilateral assistance with matched work

    Get PDF
    The finding of the highest negative metabolic rate versus mechanical work ratio in the Bilateral Matched Total Work condition means that if a constrained amount of mechanical work is available (e.g. from a battery) it is more advanta- geous to distribute this work evenly over both legs. The EMG reductions in the unassisted leg also suggest that if the goal is to maximize assistance to one (impaired) leg it might still be advantageous to use a bilateral exoskeleton, perhaps with a different actuation pattern for each leg that is specifically optimized such that each exoskeleton side assists specific phases in the impaired leg

    SCM : Secure Code Memory Architecture

    Get PDF
    An increasing number of applications implemented on a SoC (System-on-chip) require security features. This work addresses the issue of protecting the integrity of code and read-only data that is stored in memory. To this end, we propose a new architecture called SCM, which works as a standalone IP core in a SoC. To the best of our knowledge, there exist no architectural elements similar to SCM that offer the same strict security guarantees while, at the same time, not requiring any modifications to other IP cores in its SoC design. In addition, SCM has the flexibility to select the parts of the software to be protected, which eases the integration of our solution with existing software. The evaluation of SCM was done on the Zynq platform which features an ARM processor and an FPGA. The design was evaluated by executing a number of different benchmarks from memory protected by SCM, and we found that it introduces minimal overhead to the system

    Tibial acceleration-based prediction of maximal vertical loading rate during overground running : a machine learning approach

    Get PDF
    Ground reaction forces are often used by sport scientists and clinicians to analyze the mechanical risk-factors of running related injuries or athletic performance during a running analysis. An interesting ground reaction force-derived variable to track is the maximal vertical instantaneous loading rate (VILR). This impact characteristic is traditionally derived from a fixed force platform, but wearable inertial sensors nowadays might approximate its magnitude while running outside the lab. The time-discrete axial peak tibial acceleration (APTA) has been proposed as a good surrogate that can be measured using wearable accelerometers in the field. This paper explores the hypothesis that applying machine learning to time continuous data (generated from bilateral tri-axial shin mounted accelerometers) would result in a more accurate estimation of the VILR. Therefore, the purpose of this study was to evaluate the performance of accelerometer-based predictions of the VILR with various machine learning models trained on data of 93 rearfoot runners. A subject-dependent gradient boosted regression trees (XGB) model provided the most accurate estimates (mean absolute error: 5.39 +/- 2.04 BW.s(-1), mean absolute percentage error: 6.08%). A similar subject-independent model had a mean absolute error of 12.41 +/- 7.90 BW.s(-1) (mean absolute percentage error: 11.09%). All of our models had a stronger correlation with the VILR than the APTA (p < 0.01), indicating that multiple 3D acceleration features in a learning setting showed the highest accuracy in predicting the lab-based impact loading compared to APTA

    Postural adjustments in catching: on the interplay between segment stabilization and equilibrium control

    Get PDF
    The purpose of this study was to investigate postural adjustments in one-handed ball catching. Specifically, the functional role of anticipatory postural adjustments (APA) during the initial arm raising and subsequent postural adjustments (SPA) for equilibrium control and ball-hand impact were scrutinized. Full-body kinematics and kinetics allowed an analysis of the mechanical consequences of raising up the arm and preparing for ball-hand impact. APA for catching were suggested to be for segment stabilization. SPA had a functional role for equilibrium control by an inverted pendulum mechanism but were also involved in preparing for the impact of the ball on the hand, which was illustrated by an increased postural response at the end of the movement. These results were compared with raising up the arm in a well-studied reaction-time task, for which an additional counter rotation equilibrium mechanism was observed. Together, our findings demonstrate that postural adjustments should be investigated in relation to their specific functional task constraints, rather than generalizing the functional role of these postural adjustments over different tasks

    SOFIA : software and control flow integrity architecture

    Get PDF
    Microprocessors used in safety-critical systems are extremely sensitive to software vulnerabilities, as their failure can lead to injury, damage to equipment, or environmental catastrophe. This paper proposes a hardware-based security architecture for microprocessors used in safety-critical systems. The proposed architecture provides protection against code injection and code reuse attacks. It has mechanisms to protect software integrity, perform control flow integrity, prevent execution of tampered code, and enforce copyright protection. We are the first to propose a mechanism to enforce control flow integrity at the finest possible granularity. The proposed architectural features were added to the LEON3 open source soft microprocessor, and were evaluated on an FPGA running a software benchmark. The results show that the hardware area is 28.2% larger and the clock is 84.6% slower, while the software benchmark has a cycle overhead of 13.7% and a total execution time overhead of 110% when compared to an unmodified processor

    Feeding history affects intraguild interactions between Harmonia axyridis (Coleoptera: Coccinellidae) and Episyrphus balteatus (Diptera: Syrphidae)

    Get PDF
    While the effect of several factors such as predator and prey size, morphology and developmental stage on intraguild predation (IGP) is widely investigated, little is known about the influence of diet on the occurrence and outcome of IGP. In the present study, the effect of the diet experienced during larval development on IGP between the ladybird Harmonia axyridis and the syrphid Episyrphus balteatus is investigated. Four diets were tested for H. axyridis: eggs of the Mediterranean flour moth Ephestia kuehniella, pea aphids, Acyrthosiphon pisum, in an ad libitum amount, pea aphids in a limited amount, and honey bee pollen. For E. balteatus only the two aphid diets were tested. First, experiments were performed to determine the quality of the various diets for development of both predators. Second, IGP experiments between H. axyridis and E. balteatus were performed both in Petri dishes and on potted pepper plants. The diet of both species influenced the incidence of IGP between H. axyridis and E. balteatus both in Petri dishes and on potted plants. In general, smaller larvae of H. axyridis (those fed on poor or restricted diet) fed more on hoverflies than large (wellnourished) ladybird larvae. Further, poorly nourished (smaller) larvae of E. balteatus were more susceptible to predation than well-fed (larger) hoverfly larvae. The observed effects were not only due to the lower fitness of larvae of both predators reared on an inferior quality diet but also to changes in predator behaviour. The results from this study show that IGP interactions are influenced by a multitude of factors, including feeding history of the organisms involved, and emphasize the importance of taking these factors into account in order to fully understand the ecological relevance of IGP
    corecore