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Ilana Kobiler Miriam Akerman Leah Huberman Dov Prusky 《Postharvest Biology and Technology》2011,59(2):166-171
In Israel, black spot caused by Alternaria alternata is the main postharvest factor that impairs the quality and reduces the storability of persimmon fruit (Diospyros kaki cv. Triumph). The fungus infects the fruit in the orchard and remains quiescent until harvest. After harvest, the pathogen slowly colonizes the fruit during storage at 0 °C, which elicits black spot symptom development 2–3 months after storage entry. A commercial postharvest dip treatment in chlorine at 500 mg L?1, released from sodium troclosene tablets, effectively controlled black spot in fruit stored for up to 2 months. However, decay incidence increased as the length of storage was extended beyond 2.5 months. The long incubation period that precedes black spot symptom development after harvest enabled the development of a series of integrative approaches for application at the pre- and postharvest stages, in combination with the commercial chlorine dip treatment, to improve the control of black spot disease. Preharvest treatments included treatment with the cytokinin-like N1-(2-chloro-4-pyridyl)-N3-phenylurea (CPPU) 30 d after fruit set, or a single spray with the curative fungicide polyoxin B 14 d before harvest, and when one of these was applied in combination with the postharvest chlorine dip treatment, the black spot infected area was reduced by 3 and 60%, respectively, compared with the chlorine dip alone. At the postharvest stage, fogging during storage, or post-storage on-line spraying with sodium troclosene, when applied in combination with the postharvest chlorine dip, improved the percentage of marketable fruit by 2 or 10%, respectively, compared with the chlorine dip alone. The results indicate that postharvest pathogens that show a slow colonization pattern might enable the integration of pre- and postharvest disease control methods to improve quality and reduce postharvest disease development. 相似文献
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由链格孢菌引起的黑斑病是导致以色列柿子(Diospyros kaki cv.Triumph)贮藏过程中果实品质下降、贮期缩短的主要因素。其病原真菌在采收前的果园中即开始侵染果实,但一直处于休眠状态。采收后,在0℃贮藏环境中病原菌开始繁殖,当贮藏2～3个月后,柿果表面出现黑斑症状。商业上采用二氯异氰尿酸钠片剂溶解后生成500 mg.L-1的氯水浸果,可在2个月的贮期内有效控制黑斑病的发生。然而,当贮期超过2个半月后,柿子果实的腐烂率则不断增加。在柿子采后出现黑斑症状之前病原真菌较长的潜伏期内,采前与采后阶段可采取一系列的综合技术措施,并与商业氯水浸果处理相结合来提高对贮藏柿果黑斑病的防控效果。采前处理包括柿子坐果30 d后,以1-(2-氯-4-吡啶)-3-苯基脲(CPPU)处理或采收前14 d以治疗性杀菌剂多抗霉素(polyoxin B)进行喷果处理。试验结果表明,与采后单独使用氯水浸果处理相比,将CPPU或polyoxin B处理与采后商业处理相结合,可使柿果黑斑浸染面积分别减小3%和60%;采收后贮藏期间二氯异氰尿酸钠喷雾处理或采后立即用二氯异氰尿酸钠喷果处理与采后商业氯水处理相结合比单独使用氯水处理可分别提高柿子好果率2%和10%。研究结果表明,对于具有较长潜伏侵染方式的采后病原菌来说,可应用采前和采后处理相结合的方法来提高果实的贮藏品质及减轻采后病害的发生。 相似文献
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In order to evaluate the protection conferred by an experimental inactivated vaccine against infectious coryza, three challenge trials were undertaken using 112 1-day-old broilers. The vaccine "Hepa Inmuno NC" included bacterial antigens of Avibacterium paragallinarum (serogroups A, B, variant B, and C) as well as antigens of Newcastle virus and hepatitis virus. Fifty-six broiler chicks were vaccinated at the first day of life at the hatchery while another 56 chicks were left unvaccinated. Three infection trials were conducted simultaneously using each of the three serogroups A, B, or C of Av. paragallinarum. In each trial, 17 vaccinated and 17 unvaccinated broilers were used. Challenge was performed at day 31 of life by injection, into the left infraorbital sinus, of approximately 1 x 10(5) colony forming units of the corresponding Av. paragallinarum strain. Clinical signs were recorded on day 2 postchallenge. All broilers were euthanatized and both infraorbital sinuses were bacteriologically examined for the presence of Av. paragallinarum on day 5 postchallenge. In comparison with the unvaccinated broilers, the vaccine significantly reduced the number of broilers with clinical signs after challenge with serogroup B, and significantly fewer vaccinated broilers were positive for the presence of Av. paragallinarum after challenge with serogroup C. On the other hand, no significant protection was observed when broilers were challenged with Av. paragallinarum from serogroup A. Despite the high infection rates in vaccinated chicks after an experimental infection with Av. paragallinarum, it was possible to reduce colonization of Av. paragallinarum (serogroup B) and clinical signs (serogroup C) in broiler chicks by vaccination at the first day of life. Further cross-protection trials should be done, including other Av. paragallinarum strains in the vaccine, especially those from serogroup A. 相似文献
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A general method for combining existing algorithms into new programs that are unequivocally preferable to any of the component algorithms is presented. This method, based on notions of risk in economics, offers a computational portfolio design procedure that can be used for a wide range of problems. Tested by solving a canonical NP-complete problem, the method can be used for problems ranging from the combinatorics of DNA sequencing to the completion of tasks in environments with resource contention, such as the World Wide Web. 相似文献
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Huberman AD Wang GY Liets LC Collins OA Chapman B Chalupa LM 《Science (New York, N.Y.)》2003,300(5621):994-998
The segregation of initially intermingled left and right eye inputs to the dorsal lateral geniculate nucleus (DLGN) during development is thought to be in response to precise spatial and temporal patterns of spontaneous ganglion cell activity. To test this hypothesis, we disrupted the correlated activity of neighboring ganglion cells in the developing ferret retina through immunotoxin depletion of starburst amacrine cells. Despite the absence of this type of correlated activity, left and right eye inputs segregated normally in the DLGN. By contrast, when all spontaneous activity was blocked, the projections from the two eyes remained intermingled. Thus, certain features of normal neural activity patterns are not required for the formation of eye-specific projections to the DLGN. 相似文献
7.
B. Aloni Leah Karni Z. Zaidman Y. Riov M. Huberman R. Goren 《The Journal of Horticultural Science and Biotechnology》2013,88(5):923-928
SUMMARYHeat stress causes abscission of flowers in pepper plants and thus reduces yield. In the present study, we investigated the involvement of ethylene in heat-stress related flower abscission, by comparing the response of flowers of bell pepper, cv. Maor, known to be sensitive to flower abscission, and flowers of paprika, cv. Lehava, a resistant cultivar of Capsicum annuum. Their differing susceptibilities to high temperatures depend on light. Under high-temperature, high-light conditions, bell pepper was less susceptible than paprika, but, under high-temperature low-light, bell pepper was more susceptible. At high temperatures, flower explant abscission was much higher with bell pepper than paprika. Ethylene production (EP) by bell pepper explants reached a maximum at 34°C and decreased at higher temperatures (42 and 48 C), while in paprika EP rates were lower and reached the maximum at 42°C. Explants of bell pepper flowers were more susceptible to exogenous ethephon than paprika flowers. The sensitivity of a collection of pepper cul-tivars to heat induced flower abscission was more closely correlated with their flower sensitivity to ethephon than with the flower EP rate. We suggest that the differential susceptibility of bell pepper and paprika to heat stress is a result of both different ethylene production by their flowers and their differing sensitivities to ethylene produced under high-temperature stress. However, the sensitivity of the flower to ethylene may be more important in inducing their abscission. 相似文献
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Laida Ramos Tania Rodríguez‐Ramos Alberto Huberman Mario Pablo Estrada 《Aquaculture Research》2013,44(7):1066-1075
To date, no hormonal treatments are available for control of shrimp reproduction and only eyestalk ablation is of practical use. The crustacean hyperglycemic hormone (CHH) is the most abundant neuropeptide of the eyestalk CHH family. It plays an important role in the regulation of hemolymph glucose levels, as its principal function, but it is also implicated in additional physiological processes such as moulting and reproduction. In the present study, the cDNA encoding Litopenaeus schmitti (Burkenroad) mature CHH was cloned into the Escherichia coli pTYB2 expression vector. Using this strategy we have obtained, for the first time, the recombinant CHH from L. schmitti with its C‐terminus fused to an intein tag. The expected fused protein of about 63 KDa was expressed in E. coli forming inclusion bodies. It was purified in a soluble form by electroelution following molecular size fractionation in sodium dodecil sulphate polyacrylamide gel electrophoresis. The ability of the chimeric CHH protein to elevate glucose levels in the hemolymph of the eyestalk‐ablated Litopenaeus vannamei (Boone) shrimps indicates that its biological activity as hyperglycemic protein is preserved. The results provide an alternative tool to obtain soluble recombinant proteins from the CHH family of neuropeptides to get a better understanding of shrimp endocrinology. 相似文献
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Strong regularities in world wide web surfing 总被引：5，自引：0，他引：5
One of the most common modes of accessing information in the World Wide Web is surfing from one document to another along hyperlinks. Several large empirical studies have revealed common patterns of surfing behavior. A model that assumes that users make a sequence of decisions to proceed to another page, continuing as long as the value of the current page exceeds some threshold, yields the probability distribution for the number of pages that a user visits within a given Web site. This model was verified by comparing its predictions with detailed measurements of surfing patterns. The model also explains the observed Zipf-like distributions in page hits observed at Web sites. 相似文献
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This work evaluates the efficiency of the administration of the disinfectant N-alkyl dimethyl benzyl ammonium chloride (TIMSEN) in the prevention of the horizontal transmission of serovars A, B, and C of Avibacterium paragallinarum, the causative agent of avian infectious coryza. This disinfectant was administered in drinking water (50 ppm) and once or twice per day by coarse spray (800 ppm, 8 ml per m3 during 3 seconds). In three trials conducted with vaccinated birds, the disinfectant reduced the clinical signs of infectious coryza significantly (P < 0.05). There was no significant effect when the product was used in a fourth trial with unvaccinated birds. Furthermore, the application of only one daily environmental spraying was sufficient to significantly reduce clinical signs. According to these results, in order to diminish the clinical signs of infectious coryza in birds vaccinated against A. paragallinarum, it is recommended to administer this disinfectant in drinking water and by environmental spraying. 相似文献