232 research outputs found

    Vorratsschutz im Ökologischen Landbau: Entscheidungshilfe durch das Computerprogramm VOEL 1.0

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    VOEL 1.0 is a decision-support software for the protection of organic stored-products that was developed for store-keepers, farmers and pest control specialists in Ger-many. Most of the information given applies to all Central European countries, except for some legislative aspects concerning registration, which are specific for Germany. The program contains a decision-support module for monitoring and control of stored product pest, an encyclopedia on pests and beneficial organisms, a key for the deter-mination of these organisms, information on registered products for stored product protection in Germany, a data bank where literature concerning associations of pests and beneficials can be retrieved, a list of references on stored product protection in general and several original papers on stored-product protection

    Mitigating the effects of future climate on maize productivity.

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    Current climate changes affect agricultural production. Crop management strategies can be used to mitigate these effects. This study was carried out to evaluate the use of crop and soil management strategies to mitigate the effects of future climate on maize yield in mesoregions of the state of Minas Gerais, Brazil. The CSM-CERESMaize model was used to simulate the effect of maize root system depth and of the amount of plant residue left on the soil surface by the previous crop in maize yield for different scenarios of change in precipitation and solar radiation. The decrease in rainfall volume reduced the average maize yield in some regions by more than 50%. The increase in solar radiation maize yield rise, while its reduction caused more than 20% yield drop in most regions. The management strategies evaluated have the potential to mitigate such effects

    Modelling management strategies to mitigate the effects of alterations of temperature and of CO2 concentration on maize.

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    Ongoing climate change may affect rainfed maize yield in Brazil, which can be attenuated by some crop management strategies. This work aimed to evaluate, by using computational modeling, management practices with potential to mitigate the effects of changes in temperature and CO2 concentration on maize yield. The CSM-CERES-Maize model was applied to simulate the mitigating potential of using maize cultivars with 0.3 m, 0.5 m and 0.7 m deep root system, associated with 0 t ha-1, 2 t ha-1 and 4 t ha-1 of crop residue left on the soil surface. A set of 33 years of daily weather data, along with soil profile data, were used to evaluate the approach in 10 regions of the state of Minas Gerais, Brazil. For most of the regions, the use of mulching and of a maize cultivar with deeper root system was not capable of attenuating the temperature rise. In contrast, any factor limiting root growth of maize to a depth of 0.30 m, causes significant yield drop, even for a scenario of reducing temperature by 3 oC or rising CO2 concentration. In warmer and drier regions, the positive response of maize to the increase in CO2 concentration was more pronounced

    Aphid and Plant Volatiles Induce Oviposition in an Aphidophagous Hoverfly

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    Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG) response of this syrphid fly to the common aphid alarm pheromone, (E)-β-farnesene (EβF), and to several plant volatiles, including terpenoids (mono- and sesquiterpenes) and green leaf volatiles (C6 and C9 alcohols and aldehydes). Monoterpenes evoked significant EAG responses, whereas sesquiterpenes were inactive, except for the aphid alarm pheromone (EβF). The most pronounced antennal responses were elicited by six and nine carbon green leaf alcohols and aldehydes [i.e., (Z)-3-hexenol, (E)-2-hexenol, (E)-2-hexenal, and hexanal]. To investigate the behavioral activity of some of these EAG-active compounds, E. balteatus females were exposed to R-(+)-limonene (monoterpene), (Z)-3-hexenol (green leaf alcohol), and EβF (sesquiterpene, common aphid alarm pheromone). A single E. balteatus gravid female was exposed for 10 min to an aphid-free Vicia faba plant that was co-located with a semiochemical dispenser. Without additional semiochemical, hoverfly females were not attracted to this plant, and no oviposition was observed. The monoterpene R-(+)-limonene did not affect the females’ foraging behavior, whereas (Z)-3-hexenol and EβF increased the time of flight and acceptance of the host plant. Moreover, these two chemicals induced oviposition on aphid-free plants, suggesting that selection of the oviposition site by predatory hoverflies relies on the perception of a volatile blend composed of prey pheromone and typical plant green leaf volatiles

    Investigating cooperation with robotic peers

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    We explored how people establish cooperation with robotic peers, by giving participants the chance to choose whether to cooperate or not with a more/less selfish robot, as well as a more or less interactive, in a more or less critical environment. We measured the participants' tendency to cooperate with the robot as well as their perception of anthropomorphism, trust and credibility through questionnaires. We found that cooperation in Human-Robot Interaction (HRI) follows the same rule of Human-Human Interaction (HHI), participants rewarded cooperation with cooperation, and punished selfishness with selfishness. We also discovered two specific robotic profiles capable of increasing cooperation, related to the payoff. A mute and non-interactive robot is preferred with a high payoff, while participants preferred a more human-behaving robot in conditions of low payoff. Taken together, these results suggest that proper cooperation in HRI is possible but is related to the complexity of the task

    Uma metodologia alternativa para o zoneamento de risco climático da cultura do milho.

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    Produzir milho sob condições de sequeiro é uma prática comum no Brasil. Neste sistema, de produção as culturas são fortemente afetadas pela inerente variabilidade climática anual e interanual, especialmente pelos veranicos, que afetam a produtividade. Uma das estratégias mais simples, com praticamente nenhum custo, para mitigar este problema é a determinação de uma janela de semeadura, que minimize os efeitos negativos da variabilidade climática na agricultura de sequeiro. Os objetivos deste estudo foram: a) usar os resultados de produtividade de milho simulada com um modelo baseado em processos, para estabelecer janelas de semeadura e b) comparar os resultados obtidos com a atual metodologia empregada pelo Ministério da Agricultura, Pecuária e Abastecimento (Mapa). Utilizou-se o modelo CSMCERES-Maize, do Sistema de Apoio à Decisão para Transferência de Agrotecnologia (DSSAT), para simular cenários de épocas de semeadura semanais, sob condições de sequeiro, para municípios do Estado de Minas Gerais. Para cada época de semeadura, determinou-se a quebra de rendimento, comparando o rendimento médio da época de semeadura atual com o maior rendimento médio obtido a partir de todas as datas de semeadura. Assim, cada data de semeadura foi associada a um risco de perda de rendimento. As janelas de semeadura obtidas a partir das simulações foram ligeiramente diferentes daquelas propostas pelo Mapa. O uso de modelos baseados em processos para simular o rendimento das culturas permite a integração de muitos fatores não considerados na atual metodologia de zoneamento agrícola utilizada pelo Mapa. A abordagem proposta tem vantagens sobre a metodologia do Ministério da Agricultura, entre as quais a possibilidade de determinar o rendimento médio esperado e a sua amplitude.bitstream/item/94391/1/bol-87.pd

    Hardness, function, emotional well-being, satisfaction and the overall sexual experience in men using 100-mg fixed-dose or flexible-dose sildenafil citrate

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    The prescribing information for sildenafil citrate (VIAGRA, Pfizer, New York, NY, USA) recommends flexible dosing (50 mg initially, adjusted to 100 or 25 mg based on effectiveness and tolerability) in most men with erectile dysfunction (ED). In many men, however, 100 mg may be the most appropriate initial dose because it would reduce the need for titration and could prevent discouragement and treatment abandonment should 50 mg be insufficient. Results of two previously published double-blind, placebo-controlled sildenafil trials of similar design except for a fixed-dose vs flexible-dose regimen were analyzed. Relative to the flexible-dose, approximately one-third more men were satisfied with an initial and fixed dose of 100 mg. In addition, tolerability was similar, and improvements from baseline in outcomes on validated, ED-specific, patient-reported questionnaires were either similar (erectile function and the percentage of completely hard and fully rigid erections) or greater (emotional well-being and the overall sexual experience). The similarity in outcomes is not surprising given that almost 90% of the men in the flexible-dose trial titrated to 100 mg after 2 weeks. These data suggest prescription of an initial dose of 100 mg for men with ED, except in those for whom it is inappropriate
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