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101.
In order to obtain a better understanding of the active defense strategy of cherimoya (Annona cherimola Mill.) fruit, hydrolytic and antifungal activity, as well as expression of proteins functionally and immunogenically related to the pathogenesis-related proteins chitinase (PR-Q) and 1,3-β-glucanase (PR-2), were estimated in fruit at different ripening stages. Increase in expression of the 27 kDa constitutive chitinase and the induction of two new proteins, a 26 kDa chitinase and a 51 kDa 1,3-β-glucanase were associated with enhanced in vitro hydrolytic and antifungal activity of the acidic protein extract in ripe fruit. Ripening modified the expression of constitutive basic isoenzymes, with a sharp decrease in both relative accumulation and hydrolytic activity. Likewise, a new basic 33 kDa chitinase was induced in the over-ripe fruit, concomitant with accumulation of a basic constitutive 76 kDa 1,3-β-glucanase. At this stage, the basic protein extract modified in vitro growth inhibition of Botrytis cinerea. Short-term high CO2 treatment delayed fruit ripening and maintained a similar distribution of activity and isoenzymatic pattern in both protein fractions to that in unripe fruit. These results indicate that the changes in the pattern of defense proteins and hydrolytic activity in cherimoyas appear to be associated with ripening. Moreover, unlike the constitutively expressed isoenzymes, only the transitorily induced chitinases and 1,3-β-glucanases were associated with an active defense-related response.  相似文献   
102.
103.
The impact of detritivorous earthworms (Eisenia andrei) on microbial community structure and function in grape marc, a lignocellulosic enriched plant residue, was investigated in a mesocosm experiment. Analysis of carbon and nitrogen pools was also carried out in order to evaluate how changes in microbial communities affect plant residue decomposition. The grape marc was completely processed after fifteen days as a result of the high density of earthworms present and the rapid gut transit time. Eisenia andrei had a large impact on the structure of the microbial community, as revealed by phospholipid fatty acid analysis. Earthworm activity reduced the abundance of both bacterial (except for Gram-negative bacteria) and fungal PLFA biomarkers relative to the control values. Decreases in microbial activity and in protease and cellulase activities were also attributable to the presence of earthworms. Moreover, earthworms strongly modified the substrate utilization patterns of microbial communities, as revealed by BIOLOG analysis. The presence of earthworms led to an increase in the utilization of some amino acids and polymers, which reached a higher substrate diversity value than that in the control mesocosm. The differences in microbial communities were accompanied by a reduction in the total C content and the labile C pool, relative to the control, although there were no significant differences in either cellulose or hemicellulose contents. However, total N content increased in both mesocosms – with and without earthworms – and the concentration of NH4+ was also enhanced by earthworm activity. The results indicate that detritivorous earthworms play a key role in decomposing fresh plant residues in the short term via their intensive interactions with microbial communities.  相似文献   
104.
Vibrio spp. are the most common and harmful shrimp pathogenic bacteria; however, microalgae and cyanobacteria have the ability to produce antimicrobial substances against these species. In this study, the organic and aqueous extracts of 28 species of marine microalgae and cyanobacteria were screened against Vibrio campbellii M1. Two of these phytoplankton species with antibacterial activity in aqueous extracts (Dunaliella tertiolecta and Skeletonema costatum) and nontoxic to brine shrimp Artemia franciscana nauplii were used to evaluate their anti‐Vibrio effect when used as green‐water cultures in Vibrio‐challenged white shrimp Litopenaeus vannamei cultures. No differences in mortality of juvenile L. vannamei were observed between treatments tested, suggesting that the pathogenicity of V. campbellii could be related to the growth stage of shrimp. The proximal composition of D. tertiolecta and S. costatum was in the recommended range for penaeid shrimp nutrition, allowing shrimp supplemented with these microalgae to have significantly greater total length and weight than control shrimp. Shrimp supplemented with S. costatum presented the highest values of organic mass (11.48 mg/organism) and growth rate (0.31 mg/d) in comparison to D. tertiolecta. These results indicate that microalgae are not only capable of producing antibacterial compounds against Vibrio but can also help shrimp nutrition.  相似文献   
105.
Mineral fertilizers, organic amendments, and pesticides are inputs commonly used in conventional farming practices. The aim of this study was to evaluate the effects of single or combined applications of spent grape marc-vermicompost, urea, and/or diuron on soil-enzyme activities and the persistence of this herbicide in soils with low organic carbon content. The application of vermicompost enhanced dehydrogenase (DHase) enzyme activity over time but altered soil urease activity to a very limited extent. The reduction in diuron concentrations and the increase in DHase activity indicated that the soil microorganisms were capable of degrading the ureic herbicide. Treatment with vermicompost and diuron had a stimulatory effect on soil microbial activity. On the whole, the application of diuron and urea to the vermicompost-amended soil raised DHase and urease activity to maximum levels (>3 μg INTF g?1 h?1 and >47 μg NH4+ g?1 h?1, respectively). The application of urea to the unamended and vermicompost-amended soil decreased diuron persistence from 18.8 and 33 d to 12.5 and 15 d, respectively. Our findings show that although vermicompost additions reduce diuron availability, this boosts diuron degradation when combined with urea. These additions, under different soil management conditions, minimize the bioavailability and persistence of diuron and consequently the risk of leaching and seepage into aquifers. Compared with untreated soils, these types of treated soils could also improve agricultural sustainability and the quality of the environment.  相似文献   
106.
The objective of this research was to culture the calanoid copepod Pseudodiaptomus euryhalinus, Johnson 1939, and the harpacticoid Tisbe monozota, Bowman, 1962, in monospecific and combined cultures (P. euryhalinus : T. monozota at 1:1, 2:1, and 1:2 starting ratios), and to compare the nauplii, copepodite, and adult production. Mean total production ranged from 740.3 ± 137.5 organisms/L (P. euryhalinus) to 884.3 ± 489.7 organisms/L (T. monozota) for monospecific cultures. The 1:1 ratio mixed cultures gave 780.4 ± 155.8 organisms/L, those with the 2:1 and 1:2 P. euryhalinus and T. monozota starting ratios produced 710.1 ± 195.2 and 799.7 ± 232.5 organisms/L, respectively, and there were no significant difference among treatments. All mixed cultures gave significantly lower copepodite productions than the monocultures of each species. In addition, the tendency to a decreased progeny production of the initial females of T. monozota indicates that the outcome of long‐term mixed cultures would production either a high dominance of P. euryhalinus, or monocultures of this species .  相似文献   
107.
This report describes the surgical anatomy and successful removal of the internal gonads in a 6-year-old male pseudohermaphrodite Friesian horse by standing laparoscopy. Gonads could not be identified by physical or ultrasonographic examination and bilateral standing flank laparoscopy revealed the presence of intra-abdominal gonads suspended from the dorsal aspect of the abdominal cavity by 10–15 cm long vascular pedicles. No evidence of female internal genitalia such as a uterus was found and bilateral gonadectomy was performed laparoscopically. Histological analysis of the excised gonads confirmed the diagnosis of male pseudohermaphroditism. Minor cosmetic surgery of the external genitalia to correct urinary misdirection was successfully performed 3 months after laparoscopic castration. Standing flank laparoscopic examination was excellent for identification and surgical removal of internal genitalia. Standing flank laparoscopy should be considered for inspection and removal of internal genitalia in intersex horses.  相似文献   
108.
The pathogenicity of Eimeria coecicola for rabbits has been demonstrated in our experiments. The animals suffered from prolonged affection of appendix lasting at least 20 days. Pathological changes appeared with the development of merogony since day 4 post infection (DPI) and were characterized by an inflammatory infiltration and abundant pyogenic component in lamina propria, swelling and coalescence of upper parts of appendix mucosa above atrophied domes, where spaces filled with stagnating inflammatory exudate, endogenic stages of coccidia, and desquamated epithelia are formed. The alteration of the epithelium and exposure of the appendix lamina propria occur in relation with the gametogony in the period of about 10 DPI. Since 8 DPI, the epithelium of the infected endogenic stages of coccidia becomes hyperplastic, proliferates into lamina propria and is subjected to necrosis. Groups of immature oocysts and their fragments remain in lamina propria and are resorbed, at least for 10 days, by granulomatous inflammatory structures with abundant multinucleate cells of the type of foreign body cells.  相似文献   
109.
During the infection caused by Trichinella pseudospiralis serious damage to muscles is partly compensated with regeneration process. Short, thin fibrillae with central position of the nuclei--regenerating myotubes originate 20--40th day post infection in endomysial tubes remaining after damaged muscle fibres, left by migrating larva. On the 10th day post infection in the vicinity of moving larva activation of nuclei and increased origin of satellite cells under basal membrane occur. With development of the infection endothelia in the vicinity of altered fibrillae are increasing in number but there is small inflammatory and fibroproductive reaction only. During the infection caused by Trichinella spiralis and T. nativa, alteration of muscle fibres is accompanied by early inflammatory and fibroproductive reaction towards immediate surroundings of larvae. In a changed segment of muscle fibre with the larva--in pseudocyst there is altered basal lamina as well, built in increased glycocalyx and in the course of 20 days encased by connective tissue. Revascularisation and regeneration in a short damaged segment does not occur even during long-lasting infection because of separation by capsule.  相似文献   
110.
Robenidine as an anticoccidial agent alone (in doses of 50 and 100 mg/kg) or in association with two other antiprotozoal compounds--pyrimethamine and sulfadoxine (in doses of 2.5 and 250 mg/kg, respectively) were tested in the treatment of chronically infected mice with an avirulent cyst-forming HF strain of Toxoplasma gondii. The efficacy of the used drugs was evaluated by the cysts number in the brains of treated mice versus control group, antibody level and viability of survived cysts by the consecutive infection of mice. According to these criteria none of the tested drugs alone or combined exhibited to be able to produce an effective cure of cyst-stage of toxoplasmosis in experimental mice.  相似文献   
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