12 research outputs found

    Ethnobotanicals for Storage Pest Management: Effect of powdered leaves of Olax zeylanica in suppressing infestations of rice weevil Sitophilus oryzae (Coleoptera: Curculionidae)

    Get PDF
    Abstract The rice weevil Sitophilus oryzae is considered the major problem in stored rice in Sri Lanka. Due to the adverse effects of pesticide usage, research on the re-evaluation and use of many ethnobotanicals as alternative storage pest control agents has been intensified. Although plant materials with insecticidal properties provide small-scale farmers with a locally available, eco-friendly and inexpensive method of control of storage insect pests, lack of understanding and knowledge prevent their widespread application. The present study was therefore undertaken to investigate the effectiveness of the botanical Olax zeylanica in controlling infestations of the rice weevil with the view of fulfilling this lack. In two separate bioassays, contact/feeding and fumigant toxicity of powdered leaves of O. zeylanica were tested against 1-7 days old adults under laboratory conditions. All experiments were conducted using a no-choice bioassay apparatus. Contact/feeding toxicity was tested by directly exposing weevils to 1.0, 3.0, 5.0 and 7.5g of leaf powder mixed with 100g of rice grains while fumigant toxicity was evaluated by using the same doses where weevils were exposed to fumes emitted from the leaf powders. In both bioassays 100% mortality of the weevils was observed within 18 hours of exposure to 3.0, 5.0 and 7.5g doses of leaf powder. Percentage weevil mortality in treated rice tested with three doses of leaf powder at all the time intervals (except for 1.0g) was significantly higher (p < 0.05) than that of the corresponding control. No Contact/feeding toxicity was recorded when weevils were directly exposed to 1.0g leaf powder whereas only 14% weevil mortality was observed even after 24hours of exposure to fumes of leaf powder. Results also revealed that weevil mortality increased both with increasing dose and time of exposure. It is of interest to note that in both bioassays a 100% weevil mortality was obtained after 18 hours of exposure to a lower amount of leaf powder such as 3.0g, when the adults were either directly exposed to the leaf powder or to its fumes. Moreover, LD50 values of 2.55g and 2.08g for leaf powders obtained after 12 hours of exposure to insects in contact/feeding toxicity test and fumigation test respectively indicated that leaf powder is more toxic to weevils when they were in direct contact with it. Findings of the present study bears out the exceptionally high efficacy of O. zeylanica leaves applied directly mixed with the food material or introduced as a fumigant to suppress weevil infestations in stored grains and strengthen the possibility of using this plant as an alternative to synthetic chemicals in storage pest management. Keywords: Olax zeylanica, Sitophilus oryzae, Direct Contact/Feeding Toxicity, Direct Fumigation Toxicit

    Importance of the Inverted Control in Measuring Holistic Face Processing with the Composite Effect and Part-Whole Effect

    Get PDF
    Holistic coding for faces is shown in several illusions that demonstrate integration of the percept across the entire face. The illusions occur upright but, crucially, not inverted. Converting the illusions into experimental tasks that measure their strength - and thus index degree of holistic coding - is often considered straightforward yet in fact relies on a hidden assumption, namely that there is no contribution to the experimental measure from secondary cognitive factors. For the composite effect, a relevant secondary factor is size of the "spotlight" of visuospatial attention. The composite task assumes this spotlight can be easily restricted to the target half (e.g., top-half) of the compound face stimulus. Yet, if this assumption were not true then a large spotlight, in the absence of holistic perception, could produce a false composite effect, present even for inverted faces and contributing partially to the score for upright faces. We review evidence that various factors can influence spotlight size: race/culture (Asians often prefer a more global distribution of attention than Caucasians); sex (females can be more global); appearance of the join or gap between face halves; and location of the eyes, which typically attract attention. Results from five experiments then show inverted faces can sometimes produce large false composite effects, and imply that whether this happens or not depends on complex interactions between causal factors. We also report, for both identity and expression, that only top-half face targets (containing eyes) produce valid composite measures. A sixth experiment demonstrates an example of a false inverted part-whole effect, where encoding-specificity is the secondary cognitive factor. We conclude the inverted face control should be tested in all composite and part-whole studies, and an effect for upright faces should be interpreted as a pure measure of holistic processing only when the experimental design produces no effect inverted.Australian Research Council DP0984558 to Elinor McKone; Australian Research Council Centre of Excellence in Cognition and its Disorders (project number CE110001021); Kate Crookes salary supported by Hong Kong Research Grants Council grant (HKU744911) to William Hayward

    Importance of the inverted control in measuring holistic face processing with the composite effect and part-whole effect

    Get PDF
    Holistic coding for faces is shown in several illusions that demonstrate integration of the percept across the entire face. The illusions occur upright but, crucially, not inverted. Converting the illusions into experimental tasks that measure their strength - and thus index degree of holistic coding - is often considered straightforward yet in fact relies on a hidden assumption, namely that there is no contribution to the experimental measure from secondary cognitive factors. For the composite effect, a relevant secondary factor is size of the "spotlight" of visuospatial attention. The composite task assumes this spotlight can be easily restricted to the target half (e.g., top-half) of the compound face stimulus. Yet, if this assumption were not true then a large spotlight, in the absence of holistic perception, could produce a false composite effect, present even for inverted faces and contributing partially to the score for upright faces.We reviewevidence that various factors can influence spotlight size: race/culture (Asians often prefer a more global distribution of attention than Caucasians); sex (females can be more global); appearance of the join or gap between face halves; and location of the eyes, which typically attract attention. Results from five experiments then show inverted faces can sometimes produce large false composite effects, and imply that whether this happens or not depends on complex interactions between causal factors. We also report, for both identity and expression, that only top-half face targets (containing eyes) produce valid composite measures. A sixth experiment demonstrates an example of a false inverted part-whole effect, where encoding-specificity is the secondary cognitive factor.We conclude the inverted face control should be tested in all composite and part-whole studies, and an effect for upright faces should be interpreted as a pure measure of holistic processing only when the experimental design produces no effect inverted

    Facilitating free travel in the Schengen area - A position paper by the European Association for Biometrics

    Get PDF
    Due to migration, terror‐threats and the viral pandemic, various EU member states have re‐established internal border control or even closed their borders. European Association for Biometrics (EAB), a non‐profit organisation, solicited the views of its members on ways which biometric technologies and services may be used to help with re‐establishing open borders within the Schengen area while at the same time mitigating any adverse effects. From the responses received, this position paper was composed to identify ideas to re‐establish free travel between the member states in the Schengen area. The paper covers the contending needs for security, open borders and fundamental rights as well as legal constraints that any technological solution must consider. A range of specific technologies for direct biometric recognition alongside complementary measures are outlined. The interrelated issues of ethical and societal considerations are also highlighted. Provided a holistic approach is adopted, it may be possible to reach a more optimal trade‐off with regards to open borders while maintaining a high‐level of security and protection of fundamental rights. European Association for Biometrics and its members can play an important role in fostering a shared understanding of security and mobility challenges and their solutions

    Facilitating free travel in the Schengen area—A position paper by the European Association for Biometrics

    No full text
    Due to migration, terror-threats and the viral pandemic, various EU member states have re-established internal border control or even closed their borders. European Association for Biometrics (EAB), a non-profit organisation, solicited the views of its members on ways which biometric technologies and services may be used to help with re-establishing open borders within the Schengen area while at the same time mitigating any adverse effects. From the responses received, this position paper was composed to identify ideas to re-establish free travel between the member states in the Schengen area. The paper covers the contending needs for security, open borders and fundamental rights as well as legal constraints that any technological solution must consider. A range of specific technologies for direct biometric recognition alongside complementary measures are outlined. The interrelated issues of ethical and societal considerations are also highlighted. Provided a holistic approach is adopted, it may be possible to reach a more optimal trade-off with regards to open borders while maintaining a high-level of security and protection of fundamental rights. European Association for Biometrics and its members can play an important role in fostering a shared understanding of security and mobility challenges and their solutions. © 2023 The Authors. IET Biometrics published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology

    In Vitro α-Amylase and Protein Glycation Inhibitory Activity of the Aqueous Extract of Flueggea leucopyrus Willd

    No full text
    There is much interest in plant-based medicine with antidiabetic and antiglycation properties. Chronic hyperglycemia plays a vital role in the development of long-term diabetic complications by inducing protein glycation and the gradual formation of advanced glycation end products (AGEs) in various body tissues. The main objectives of this study were to investigate the aqueous extract of the whole plant of Flueggea leucopyrus Willd (FLAE), a medicinal plant used in traditional medicine in Sri Lanka for its in vitro α-amylase inhibitory activity and its inhibitory potential on the formation of AGEs. α-Amylase inhibitory activity determined by 3,5-dinitrosalicylic acid method revealed that FLAE possesses 29%–91% inhibitory activity at a concentration range of 2.5–400 μg/mL, respectively. Nonenzymatic protein glycation inhibitory capacity assessed by bovine serum albumin-fructose fluorescence spectrometric assay showed that FLAE at 15.6–250.0 μg/mL inhibited AGE formation by 0.9%–98%, respectively. Radical scavenging ability of FLAE using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and total phenolic and flavonoid contents of FLAE were also determined. This study shows that Flueggea leucopyrus Willd not only inhibits α-amylase enzyme, which is known to break starch to glucose, but also inhibits the formation of AGEs, which occur due to chronic hyperglycemia that leads to the onset of diabetic complications

    Asia has the global advantage: Race and visual attention

    No full text
    In studies of visual attention, and related aspects of cognition, race (continent/s of ancestry) of participants is typically not reported, implying that authors consider this variable irrelevant to outcomes. However, there exist several findings of perceptual differences between East Asians and Caucasian Westerners that can be interpreted as relative differences in global versus local distribution of attention. Here, we used Navon figures (e.g., large E made up of small Vs) to provide the first direct comparison of global-local processing using a standard method from the attention literature. Relative to Caucasians, East Asians showed a strong global advantage. Further, this extended to the second generation (Asian-Australians), although weakened compared to recent immigrants. Our results argue participants' race should be reported in all studies about, or involving, visual attention to spatially distributed stimuli: to continue to ignore race risks adding noise to data and/or drawing invalid theoretical conclusions by mixing functionally distinct populations
    corecore