27 research outputs found

    Effect of grain type on the insecticidal efficacy of Paya® against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

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    The objective of the current study was to determine the insecticidal effectiveness of diatomaceous earth formulation (DE) Paya®. The effects of grain commodity (wheat, barley, maize and rice), exposure times and dose rates were evaluated. The efficacy of diatomaceous earth (DE) against 1–7 days old adults of Tribolium castaneum (Herbst) was evaluated on wheat, rice, maize and barley at 26±1 °C and 60±5% RH in darkness. The mortality of adults was tested at five concentrations: 0.125, 0.25, 0.5, 1 and 1.5 g/kg of grain and different exposure times (24, 48 h, 7 and 14 d). To evaluate the progeny production, dead and alive adults were removed from containers after 14 days and these containers were kept at above-mentioned conditions for 45 days. The results obtained indicated that the highest adult mortality was observed after the longest exposure period on barley and wheat so that the two highest DE dosages caused 100% mortality of T. castaneum. The efficacy of Paya® on maize and rice was not satisfactory, given that after a 14 days exposure at the highest dose rate the mortality did not exceed 37% and 66% in the case of maize and rice, respectively. The results demonstrated that the mortality increased with rises in concentration and exposure time and also highly affected by grain type

    Referential gestures are not ubiquitous in wild chimpanzees : alternative functions for exaggerated loud scratch gestures

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    Royal Zoological Society of Scotland for providing core funding for Budongo Conservation Field Station. This work was supported by the ERC grant awarded to KS (ERC_CoG 2016_724608).A fundamental aspect of human communication is our ability to refer to external objects and events through both words and gestures (such as pointing), yet the evolutionary origins of such signals remain obscure. Apes, living in their natural environments, rarely or never point, but it has been claimed that male chimpanzees, Pan troglodytes schweinfurthii, from the Ngogo community, Uganda, habitually use exaggerated loud scratches (ELSs) to refer to specific body locations where they wish to be groomed (Pika & Mitani, 2006, Current Biology, 16(6), 191–192). This study suggested continuity between referential abilities in humans and our closest living relatives, making it an important finding to replicate in other populations. Hence here, we compared whether ELSs are used in a referential manner across four wild communities of eastern chimpanzees (Ngogo, Kanyawara, Sonso and Waibira). Our data show that scratchers were significantly more likely to receive grooming in the scratched location at Ngogo compared to the other three sites. At the latter sites this response occurred at low rates and signallers did not seem to pursue this goal. This suggests that ELSs do not function referentially at these sites, and the published findings from Ngogo were not replicated. Further exploration into alternative functions of ELSs in the Kanyawara community revealed that, in this community, this signal functions to initiate grooming bouts and to reengage partners during grooming pauses. Individuals who produced the signal to initiate grooming were likely to offer grooming. In contrast, during grooming bouts, groomers produced ELSs to request reciprocation of grooming from their partner. Our study demonstrates that chimpanzees do not ubiquitously use the ELS in a referential manner, but that they can use this gesture in a highly flexible fashion, with signal function depending on the intricate details of the social contexts in which they are produced.Publisher PDFPeer reviewe

    Power maximization of variable-speed variable-pitch wind turbines using passive adaptive neural fault tolerant control

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    Power maximization has always been a practical consideration in wind turbines. The question of how to address optimal power capture, especially when the system dynamics are nonlinear and the actuators are subject to unknown faults, is significant. This paper studies the control methodology for variable-speed variable-pitch wind turbines including the effects of uncertain nonlinear dynamics, system fault uncertainties, and unknown external disturbances. The nonlinear model of the wind turbine is presented, and the problem of maximizing extracted energy is formulated by designing the optimal desired states. With the known system, a model-based nonlinear controller is designed; then, to handle uncertainties, the unknown nonlinearities of the wind turbine are estimated by utilizing radial basis function neural networks. The adaptive neural fault tolerant control is designed passively to be robust on model uncertainties, disturbances including wind speed and model noises, and completely unknown actuator faults including generator torque and pitch actuator torque. The Lyapunov direct method is employed to prove that the closed-loop system is uniformly bounded. Simulation studies are performed to verify the effectiveness of the proposed method

    An <i>in vivo</i> method for measuring the adsorption of plasma proteins to titanium in humans

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    <div><p>A novel method of collecting <i>in vivo</i> plasma proteins of humans from osteotomies prepared during insertion of an oral implant is described. A rod containing a collecting portion with a predetermined surface is introduced into the osteomy, removed, and transferred for enzyme-linked immunosorbent assay analysis. Two experiments were used to examine the feasibility of the method. In the first, titanium (Ti) rods with different roughness were exposed for 10 min to the blood. Blasted and acid-etched surfaces adsorbed four times more and acid-etched surfaces adosorbed two times more plasma proteins as compared to machined surfaces. In the second experiment, blasted and acid-etched rods were wetted for 10 s prior to the insertion. The adsorption for fibronectin, albumin, fibrinogen, and IgG was enhanced significantly compared with nonwetted rods. These results are discussed in the light of previous methods used in studies on adsorption. Thus, use of the collecting instrument enables aspects of human plasma–implant interface to be studied in a more realistic manner.</p></div

    An in vivo

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