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1.
The probit 9 standard for quarantine treatment efficacy (99.9968% mortality) was originally recommended for tropical fruits heavily infested with fruit flies and it centers on high mortality to achieve quarantine security. This standard may be too stringent for quarantine pests in commodities that are rarely infested or are poor hosts, The alternative treatment efficacy approach measures risk as the probability of a mating pair, gravid female, or parthenogenic individual surviving in a shipment. This will be a function of many factors including infestation rate and shipment volume. Applying the risk-based alternative treatment efficacy approach to pests on rarely infested or poor hosts will lower the number of required test insects needed for developing quarantine treatments; hence data for a quarantine treatment could be generated by testing 10,000 or fewer insects with no survivors, compared with 90,000-100,000 insects to demonstrate the traditional probit 9 efficacy. Several commodity/quarantine pest systems where this approach could be applied are discussed. This approach would save time and resources, and help farmers export their crop on a more-timely basis. 相似文献
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Neven LG 《Journal of economic entomology》2005,98(3):709-715
Nonchemical quarantine treatments, using a combination of short-duration high temperatures under low oxygen, elevated carbon dioxide atmospheric environment were developed to control codling moth in sweet cherries, Prunus avium (L.). The two treatments developed are a chamber temperature of 45 degrees C for 45 min and a chamber temperature of 47 degreesC for 25 min under a 1% oxygen, 15% carbon dioxide, -2 degrees C dew point environment. Both these treatments have been shown to provide control of all life stages of codling moth while preserving commodity market quality. The third and fourth instars of codling moth are equally tolerant to CATTS treatments and are the most tolerant immature stages to these treatments. We determined that low levels of oxygen are more important than elevated carbon dioxide in achieving high levels of insect mortality. Efficacy tests of both treatments resulted in 100% mortality of 5000 third instars of codling moth in each treatment. These treatments may be used to provide quarantine security in exported sweet cherries where codling moth is a quarantine concern and fumigation with methyl bromide is not desired. 相似文献
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Nonchemical quarantine treatments, using a combination of short duration high temperatures under low oxygen, elevated carbon dioxide atmospheric environment were developed to control western cherry fruit fly, Rhagoletis indifferens Curran, in sweet cherries, Prunus avium (L.). The two treatments developed use a chamber temperature of 45 degrees C for 45 min and a chamber temperature of 47 degreesd C for 25 min, both under a 1% oxygen, 15% carbon dioxide, -2 degrees C dew point environment. Both these treatments have been shown to provide control of all life stages of western cherry fruit fly while preserving commodity market quality. There was no definitive egg or larval stage, which was demonstrated to be the most tolerant to either controlled atmosphere temperature treatment system treatment. Efficacy tests for both treatments resulted in 100% mortality of >5000 western cherry fruit flies in each treatment. These treatments may provide, with further study, quarantine security in exported sweet cherries where western cherry fruit fly is a quarantine concern and fumigation with methyl bromide is not desired. 相似文献
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Neven LG 《Journal of economic entomology》2008,101(2):295-301
The development of postharvest quarantine treatments can be both expensive and time-consuming. It is necessary to determine the species and stage of the pest most tolerant to the treatment, if more than one species is the target of the treatment. Initial laboratory studies often include infesting the commodity with various egg and larval stages of the pest and performing treatments and evaluations of the fruit. In collaboration with others, I have previously developed combination high temperature under controlled atmosphere treatments against two quarantine pests in apples (Malus spp.) and peaches and nectarines (both Prunus spp.). I decided to develop an artificial system that can be used for these initial tests without the need for infesting large quantities of the fruit. I tested the system on the immature stages of the pests under regular air and controlled atmospheres by using the controlled atmosphere water bath system. This system can be used for rapid assessment of the most tolerant stage and species of a pest to a combination heat and controlled atmosphere treatment without the expense of infesting, treating, and evaluating the commodity. 相似文献
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A simple method for detecting sterigmatocystin in agricultural commodities by minicolumn chromatography was developed. Clean-up as well as semi-quantitative estimation could be done on the same column. The method is suitable for the analysis of samples of rice, wheat, maize and sorghum contaminated with sterigmatocystin and could be used as an effective preliminary screening technique in public health laboratories. 相似文献
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An international committee known as COSPAR has agreed that the probability of a single viable organism aboard any unmanned spacecraft intended for planetary landing should be kept less than 10–3, in agreement with work by Sagan and Coleman. At present, the U.S.A. is committed to remain consistent with this standard. Using a model which includes both expected losses from failures to collect data and from contamination to analyze the quarantine problem, evidence is given which suggests that the current quarantine requirements may be too strict if their implementation forces a program delay. U.S. policy should be re-examined, keeping more fully in mind both the types and the relative sized of the losses which might be encountered. 相似文献
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Tae Hyung Kwon Chung Gyoo Park Byung-Ho Lee Dominique R. Zarders Gwang Hyun Roh Paul E. Kendra Dong H. Cha 《Journal of Asia》2021,24(1):129-135
Spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), is a serious invasive pest of berries and cherries in the U.S. and Europe and has become a major phytosanitary trade barrier. In this pilot study, we explored the potential of using stand-alone ethyl formate (EF) treatment and a combinatory treatment of EF and cold temperature as postharvest control options for D. suzukii in imported blueberries. Stand-alone EF fumigations were effective against D. suzukii with LCt99% of 207.7 and 168.5 g·h·m?3 for eggs, the most tolerant life stage, at 5 and 21 °C, respectively. In a scale-up (10 m3) trial conducted at 5 °C, complete control of D. suzukii eggs placed inside and outside of blueberry boxes was achieved using 70 g·m?3 EF for 4 h with 5% blueberry loading ratio without deleterious impact on blueberry appearance such as soft spot or berry shrivel. In small scale pilot studies, 9-d stand-alone cold treatment at 5 °C was sufficient for complete control of D. suzukii eggs and larvae tested, but not pupae. The efficacy of this cold treatment appeared to be improved when D. suzukii eggs were first treated with low-dose EF (LCt50% level) prior to the cold treatment. The combination treatment resulted in complete mortality of D. suzukii eggs, larvae, and pupae tested after 7, 5, and 9 d of cold treatment, respectively. Together, these results suggest that stand-alone EF treatment, or the combination treatment of low-dose EF and cold as a systems approach may have a potential as postharvest treatments for D. suzukii in blueberries. 相似文献
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Nemeroff CB 《Neuron》2008,59(2):185-186
Depression during pregnancy and in the postpartum period is common, devastating to mothers and their offspring, and poorly understood in terms of pathophysiology. In this issue of Neuron, Maguire and Mody provide evidence for a role for aberrant neurosteroid regulation of the GABA(A) receptor subunit in the etiology of postpartum depression, presaging elucidation of the pathophysiology and development of treatments of this depression endophenotype. 相似文献
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The conserved COP9 signalosome (CSN) multiprotein complex is located at the interface between cellular signaling, protein modification, life span and the development of multicellular organisms. CSN is required for light-controlled responses in filamentous fungi. This includes the circadian rhythm of Neurospora crassa or the repression of sexual development by light in Aspergillus nidulans. In contrast to plants and animals, CSN is not essential for fungal viability. Therefore fungi are suitable models to study CSN composition, activity and cellular functions and its role in light controlled development. 相似文献
13.
A role for CCR9 in T lymphocyte development and migration 总被引:14,自引:0,他引:14
Uehara S Grinberg A Farber JM Love PE 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(6):2811-2819
CCR9 mediates chemotaxis in response to CCL25/thymus-expressed chemokine and is selectively expressed on T cells in the thymus and small intestine. To investigate the role of CCR9 in T cell development, the CCR9 gene was disrupted by homologous recombination. B cell development, thymic alphabeta-T cell development, and thymocyte selection appeared unimpaired in adult CCR9-deficient (CCR9(-/-)) mice. However, competitive transplantation experiments revealed that bone marrow from CCR9(-/-) mice was less efficient at repopulating the thymus of lethally irradiated Rag-1(-/-) mice than bone marrow from littermate CCR9(+/+) mice. CCR9(-/-) mice had increased numbers of peripheral gammadelta-T cells but reduced numbers of gammadeltaTCR(+) and CD8alphabeta(+)alphabetaTCR(+) intraepithelial lymphocytes in the small intestine. Thus, CCR9 plays an important, although not indispensable, role in regulating the development and/or migration of both alphabeta(-) and gammadelta(-) T lymphocytes. 相似文献
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Natural compounds, mostly from plants, have been the mainstay of traditional medicine for thousands of years. They have also been the source of lead compounds for modern medicine, but the extent of mining of natural compounds for such leads decreased during the second half of the 20th century. The advantage of natural compounds for the development of drugs derives from their innate affinity for biological receptors. Natural compounds have provided the best anti-malarials known to date. Recent surveys have identified many extracts of various organisms (mostly plants) as having antiplasmodial activity. Huge libraries of fractionated natural compounds have been screened with impressive hit rates. Importantly, many cases are known where the crude biological extract is more efficient pharmacologically than the most active purified compound from this extract. This could be due to synergism with other compounds present in the extract, that as such have no pharmacological activity. Indeed, such compounds are best screened by cell-based assay where all potential targets in the cell are probed and possible synergies identified. Traditional medicine uses crude extracts. These have often been shown to provide many concoctions that deal better with the overall disease condition than with the causative agent itself. Traditional medicines are used by ~80 % of Africans as a first response to ailment. Many of the traditional medicines have demonstrable anti-plasmodial activities. It is suggested that rigorous evaluation of traditional medicines involving controlled clinical trials in parallel with agronomical development for more reproducible levels of active compounds could improve the availability of drugs at an acceptable cost and a source of income in malaria endemic countries. 相似文献
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Influence of different post-planting treatments on the development in Holm oak afforestation 总被引:1,自引:0,他引:1
M. N. Jiménez E. Fernández-Ondoño M. A. Ripoll F. B. Navarro E. Gallego E. De Simón A. M. Lallena 《Trees - Structure and Function》2007,21(4):443-455
This work examines the influence of different post-planting treatments in the development of afforested Holm oak, Quercus ilex L. subsp. ballota (Desf.) Samp., in an abandoned agricultural field in SE Spain. A total of nine post-planting treatments were carried out: tilling spring and autumn in different years, spreading of organic and inorganic mulch, irrigation in different periods. Soil preparation prior to planting consisted of digging of a hole with a backhoe excavator of 80 HP and homogenized the profile characteristics. Survival, nutrient concentrations in both leaves and soil, and foliage surface have been studied. Dry-season irrigation every 2 weeks provided the best survival rate (98.3%), while mulching with solid urban wastes caused the worst results (6.6%). The supply of forest debris increased the N, K, and Mn concentrations at all depths with respect to the other treatments, and the solid urban waste had the same effect in N, P, K, Na, Cu, Fe, and Zn. All the foliar nutrients decreased in 2005 with respect to the 2004 sampling, except in N, Cu, and Zn. The use of foliar nutrient concentrations, together with the increase in leaf surface is proposed as a non-destructive index of development and of forestation stands in the first stages of growth. The application of forest debris, and particularly the placement of boulders in the beds of individual trees proved most effective in sapling development. 相似文献
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The effects of gene injection-related handling on the subsequent development of in vitro-produced bovine oocytes were studied. In Experiment 1, centrifuged oocytes were stored in an injection chamber for 30 min on a warm (+39 degrees C) stage at 18, 22, 26 or 30 h post insemination. In Experiment 2, centrifuged oocytes were stored for 60, 90 or 120 min on a warm stage, while in Experiment 3 they were stored for 60 min on a warm or cool (+22 degrees C) stage. In Experiment 4, the centrifuged zygotes were injected with buffer either into the pronucleus or cytoplasm. Development to morulae and blastocysts at Day 7 was monitored. The results indicate that handling of oocytes either very early (18 h post insemination) or very late (30 h post insemination) significantly reduced development (P<0.05). The duration of the storage or the temperature during storage did not have any significant effect on the development of the embryos. Development (counted from the cleaved ova), however, was significantly lower (P<0.01) in pronucleus-injected than in cytoplasm-injected or control embryos (27.7, 45.5 and 44.0% morulae and blastocysts, respectively). The conclusion of this study is that the main reason for decreased development of pronucleus-injected, in vitro-produced bovine zygotes is the pronucleus-injection itself rather than injection-related handling or the overall damage caused by zygote piercing. 相似文献
18.
John Frank Eshun José Potting Rik Leemans 《The International Journal of Life Cycle Assessment》2010,15(7):715-725
Background, aim, and scope
The timber sector, i.e., forestry and timber industry, plays an important role in the socioeconomic development of Ghana through timber products export. Timber production in this sector is associated with increasing environmental burdens in terms of use of materials and energy, production of emissions and waste, and land use changes. The purpose of this study was to compile a comprehensive life cycle inventory (LCI) to identify the most dominant environmental pressures for five major production lines in the timber industry, and to evaluate the influence of the choice of the functional unit on the results (1 m3, 1 kg, and 1 euro). LCA’s of wood typically base their functional unit on volume, but mass or money may be more appropriate for the rather different products considered in this study. 相似文献19.
Thresholds, equilibria, and their stability are found for SIQS and SIQR epidemiology models with three forms of the incidence. For most of these models, the endemic equilibrium is asymptotically stable, but for the SIQR model with the quarantine-adjusted incidence, the endemic equilibrium is an unstable spiral for some parameter values and periodic solutions arise by Hopf bifurcation. The Hopf bifurcation surface and stable periodic solutions are found numerically. 相似文献