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951.
952.
Laboratory assays indicated that infective-stage juveniles of Neoaplectana carpocapsae are highly pathogenic to Simulium spp. larvae. Instar susceptibility increased with larval size, with early instars being nonsusceptible. High rates of mortality (75 – 100%) were achieved in assays against late instars. These results indicate that N. carpocapsae may have potential value as a blackfly biocontrol agent. 相似文献
953.
Use of intrauterine devices as a means of contraception in a colony of chimpanzees (Pan troglodytes)
The uncontrolled reproduction of the captive chimpanzee colony at the Primate Centre, CIRMF, Gabon, has led to high neonatal mortality. The only solution meeting ethical, financial, and practical considerations was to attempt reversible physical contraception using intrauterine devices (IUDs). Human IUDs were inserted into 21 females of various ages, parities, and stages of the menstrual cycle. Over a 30-month period, five of the study animals became pregnant. This reduction of conception rate, with minimal side effects, demonstrates the reliability of IUDs for controlling reproduction of chimpanzee colonies. 相似文献
954.
Bioluminescence in the unicellular dinoflagellate Gonyaulax polyedra represents an excellent model for studying a circadian controlled process at the biochemical and molecular levels. There are three key components involved in the bioluminescence reaction: the enzyme, luciferase, its substrate, luciferin, and a luciferin-binding protein (LBP), which sequesters the substrate at pH 7.5 and thus prevents it from reacting with the enzyme. All components are tightly packed together in organdies, designated scintillons. The entire bioluminescent system is under circadian control with maximum amounts in the night. For both proteins circadian control is exerted at the translational level. In case of Ibp mRNA a small interval in its 3'untranslated region serves as a cis -acting element to which a trans -factor binds in a circadian manner. The binding activity of this factor decreases at the beginning of the night phase, when synthesis of LBP starts, and it increases al the end of the night, when synthesis of LBP stops indicating that it functions as a clock-controlled represser. 相似文献
955.
Mass‐reared sterile tephritid flies released in sterile insect technique (SIT) programmes exhibit behaviour, physiology and longevity that often differ from their wild counterparts. In the present study, video recordings of flies in laboratory cages are used to determine whether the sequential processes of mass‐rearing and sterilization (using gamma radiation) that are integral to SIT affect general activity patterns of male and female Queensland fruit flies Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) (‘Q‐flies'). Compared with wild flies, mass‐reared flies exhibit a marked reduction in overall activity, and further reduction is found after sterilization. In terms of the frequency of activities, both fertile and sterile mass‐reared Q‐flies fly less often and exhibit more bouts of inactivity and grooming than wild Q‐flies. In addition, in terms of the duration of activities, fertile and sterile mass‐reared Q‐flies spend less time flying and more time walking, grooming and being inactive than wild Q‐flies. Although fertile and sterile mass‐reared flies are similar in other regards, sterile mass‐reared flies spend more time being inactive than fertile mass‐reared flies. These findings raise new questions about how changes in behaviour and activity levels may influence the performance of mass‐reared sterile Q‐flies in the field, as well as the physiological and metabolic processes that are involved. The frequency and duration of inactivity could provide a simple but powerful and biologically relevant test for quality in mass‐rearing and SIT programs. 相似文献
956.
In trials conducted in Benin, conidia of Beauveria bassiana were evaluated as a control method against the cowpea weevil, Callosobruchus maculatus , in stored cowpea. In the first trial using a high artificial infestation of C. maculatus in 8-kg batches of cowpea in jerry cans under typical conditions, concentrations of 1 × 109 and 1 × 1011 conidia kg−1 were compared with lemon grass oil at 2 mL kg−1 and the synthetic pesticide mixture of 1.5% pirimiphos methyl + 0.05% deltamethrin at 0.5 g kg−1 . After 2 months of storage, seed losses (SD) were 20.63 (5.3)% in the untreated control, 8.04 (3.2)% in the low-dose B. bassiana group, 3.12 (1.3)% in the high-dose B. bassiana group, 2.52 (0.4)% in the lemon grass oil group and 0% in the pirimiphos methyl + deltamethrin group. In a second trial with natural infestations in 50-kg batches of cowpea in 200-L drums, treatment with B. bassiana 1 × 1011 conidia kg−1 was compared with pirimiphos methyl + deltamethrin at 0.5 g kg−1 . After 6 months of storage on six farms, losses reached 30.76 (1.5)% in the control, 1.28 (0.2)% in the pirimiphos methyl + deltamethrin group and 3.69 (0.6)% in the B. bassiana group. 相似文献
957.
Aims: To assess the impact of Bacillus amyloliquefaciens and Microbacterium oleovorans on bacterial and fungal groups associated to the roots of field-grown maize.
Methods and Results: Identification and count of bacterial and fungal culturable populations associated to the roots of maize seedlings, changes in culturable community structure according to the richness and diversity indexes concept and shifts in microbial activity through analysis of cellulolytic, ammonification and nitrification potentials were determined, in relation to kernel treatment with biological control agents. Following the treatment of maize kernels with B. amyloliquefaciens at 107 CFU ml−1 , an increase in bacterial diversity was observed at the rhizoplane of resultant seedlings. Bacterial richness was significantly increased at the root inner tissues of seedlings treated with Mic. oleovorans . Fusarium , Aspergillus , Penicillium and Trichoderma were the main fungal genera isolated and there population sizes were unequally affected by the addition of biocontrol agents.
Conclusions: Numbers and types of isolated bacteria and fungi changed in response to the addition of biocontrol agents, while microbial activity remained unchanged with respect to control.
Significance and Impact of the Study: This study provides an insight of the effects of proven biocontrol agents on micro-organisms naturally associated to the target crop. 相似文献
Methods and Results: Identification and count of bacterial and fungal culturable populations associated to the roots of maize seedlings, changes in culturable community structure according to the richness and diversity indexes concept and shifts in microbial activity through analysis of cellulolytic, ammonification and nitrification potentials were determined, in relation to kernel treatment with biological control agents. Following the treatment of maize kernels with B. amyloliquefaciens at 10
Conclusions: Numbers and types of isolated bacteria and fungi changed in response to the addition of biocontrol agents, while microbial activity remained unchanged with respect to control.
Significance and Impact of the Study: This study provides an insight of the effects of proven biocontrol agents on micro-organisms naturally associated to the target crop. 相似文献
958.
In this article, a model‐free feedback control design is proposed for the drug administration in mixed cancer therapy. This strategy is very attractive because of the important issue of parameter uncertainties unavoidable when dealing with biological models. The proposed feedback scheme use past measurements to update an on‐line simplified model. The control design is then based on model predictive control in which a suitable switching is performed between two different cost functions. The effectiveness of the proposed model‐free control strategy is validated using a recently developed model (unknown to the controller) governing the cancer growth on a cells population level under combined immune and chemotherapy and using real human data. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献
959.
The improvement of various cognitive skills associated with video game play has been well documented; however, the development of consciousness implications have not been considered. In the present study several potential indicators of consciousness development, including and especially lucid dreaming frequency, were examined as a function of video game play. In the first study, high video game players were more likely to report lucid dreams, observer dreams, and dream control when dream recall frequency and motion disorientation during play were controlled. There were no similar differences in other consciousness development indices. In the second study, a slightly different pattern of results occurred because of respondents all being frequent players. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
960.
Abstract Melaleuca quinquenervia (Cav.) S.T. Blake, Australian broad-leaved paperbark, has become a serious weed in southern Florida. Poliopaschia lithochlora (Lower) is a promising candidate as a potential biological control agent, and this study describes laboratory and field observations of the life history of this moth. Eggs are laid in small batches, mainly on the surface of leaves, and larvae are voracious leaf feeders, concealed in tubes that are usually found in small colonies attached to leaves and stems. Larvae move from these tubes to feed on surrounding leaves, and saplings and suckers are frequently defoliated. Prepupae form sealed bulbs in the larval tubes in which they pupate. Adult females are mainly active and oviposit at night. Development from egg to adult occurs in approximately 80 d. Field populations appear to be regulated by several egg and larval parasites. Because this moth severely damages saplings and suckers of M . quinquenervia , prefers low-lying humid sites, and can be successfully mass reared, it is rated highly for its potential as a biological control agent. 相似文献