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11.
Earthworm immune-competent cells (coelomocytes) can be adversely affected by soil metal contamination. The aim of the present paper was to perform comparative studies on the coelomocytes of four lumbricid species dermally exposed for 2 days to filter paper soaked with Ni, Cu, Zn, Cd, or Pb chlorides (1 mM). Coelomocytes were expelled by electro-stimulation, counted, and assayed ex vivo by flow cytometry and spectrofluorometry. The coelomocytes of Allolobophora chlorotica and Dendrobaena veneta contain both amoebocytes and riboflavin-storing eleocytes; consequently, they were subjected to assays based on flow cytometric quantification of autofluorescent eleocytes and spectrofluorometric measurement of riboflavin content in coelomocyte lysates. In Al. chlorotica, the number of coelomocytes, the percentage of eleocytes, and the amount of riboflavin were significantly lower in Cu-exposed worms although these cytometric parameters were less affected by Ni, Zn, Cd exposure, and entirely unaffected by Pb exposure. In D. veneta, such cellular effects were also only observed in Cu-exposed worms. The coelomic fluids of Aporrectodea caliginosa and Lumbricus rubellus are constitutionally impoverished of eleocytes; therefore, these species could not be subjected to assays measuring the riboflavin content of these granular cells. Rather, the amoebocytes of Ap. caliginosa and L. rubellus were subjected to flow cytometric measurements of in vitro neutral red uptake (NR). However, the NR uptake assay was technically demanding, requiring a strictly normalized incubation period over all samples to yield useful comparative data. In contrast, the riboflavin content in the coelomocyte lysates of eleocyte-rich species appears to be a robust and convenient immune-function biomarker of environmental stress.  相似文献   
12.
The study focused on assessing the influence of rhamnolipids on the phytotoxicity of diesel oil-contaminated soil samples. Tests evaluating the seed germination and growth inhibition of four terrestrial plant species (alfalfa, sorghum, mustard and cuckooflower) were carried out at different rhamnolipid concentrations (ranging from 0 to 1.200?mg/kg of wet soil). The experiments were performed in soil samples with a different diesel oil content (ranging from 0 to 25?ml/kg of wet soil). It was observed that the sole presence of rhamnolipids may be phytotoxic at various levels, which is especially notable for sorghum (the germination index decreased to 41?%). The addition of rhamnolipids to diesel oil-contaminated soil samples contributed to a significant increase of their phytotoxicity. The most toxic effect was observed after a rhamnolipid-supplemented diesel oil biodegradation, carried out with the use of a hydrocarbon-degrading bacteria consortium. The supplemention of rhamnolipids (600?mg/kg of wet soil) resulted in a decrease of seed germination of all studied plant species and an inhibition of microbial activity, which was measured by the 2,3,5-triphenyltetrazolium chloride tests. These findings indicate that the presence of rhamnolipids may considerably increase the phytotoxicity of diesel oil. Therefore, their use at high concentrations, during in situ bioremediation processes, should be avoided in a terrestrial environment.  相似文献   
13.
Transport of metabolites across the mitochondrial inner membrane is highly selective, thereby maintaining the electrochemical proton gradient that functions as the main driving force for cellular adenosine triphosphate synthesis. Mitochondria import many preproteins via the presequence translocase of the inner membrane. However, the reconstituted Tim23 protein constitutes a pore remaining mainly in its open form, a state that would be deleterious in organello. We found that the intermembrane space domain of Tim50 induced the Tim23 channel to close. Presequences overcame this effect and activated the channel for translocation. Thus, the hydrophilic cis domain of Tim50 maintains the permeability barrier of mitochondria by closing the translocation pore in a presequence-regulated manner.  相似文献   
14.
In both the horse and the man, nutritional ergogenic aids have been used to improve physical ability in conjunction with an appropriate training regimen. Although training increases physical condition, the ease of taking a nutritional additive to improve training results explains the demand for supplementation, which may increase mechanical energy of work, delay onset of fatigue, or improve neuromuscular coordination. The purpose of this study was to determine the effects of oral supplementation of β-hydroxy-β-methylbutyrate (HMB) and γ-oryzanol (GO) on indices of exercise-induced muscle damage in Thoroughbred race horses. In this 32-week study, the horses were assigned to either a placebo, GO (3.0 g/d), HMB (15 g/d), or GO and HMB treatment groups. The supplements were administered for the first 16 weeks of the study during the training period before the racing season began. Blood samples were taken at baseline, and then during training, before exercise, immediately after exercise, and 30 minutes after exercise. Heart rate and speed were monitored in each exercise session. Hematocrit, glucose, lactate (LA), creatine phosphokinase, and aspartate aminotransferase were measured before and after each exercise session. Analysis of variance showed a significantly greater increase in postexercise creatine kinase activity in placebo-supplemented group than in the other treatment groups, both in the training period and during the racing seasons (P < .05). Blood LA was higher immediately after exercise in the placebo group compared with the supplemented groups. In conclusion, supplementation with HMB and GO resulted in decreased creatine kinase and LA after exercise. These findings support the hypothesis that HMB and GO supplementation helps to prevent exercise-induced muscle damage.  相似文献   
15.
The behavior of 2 spectacled bears (Tremarctos ornatus) was studied at Wroclaw Zoo (Poland), where they were housed in a very small outdoor enclosure, and then in a separate study after transfer to a large naturalistic exhibit at Chester Zoo (CZ; United Kingdom). The studies combine to form an opportunistic “experiment” on the effects of transfer on zoo animals. This situation provided a unique opportunity for a closer investigation of known behavior problems and their causation. In part 1 of the study, at Wroclaw Zoo, the median amount of time devoted to stereotypical movements was 57 min/h. After the move to CZ, immediate changes in behavior were reported in 1 individual, for whom the stereotypy was eradicated. The other bear continued performing repetitive behavior of high intensity and only used a small area of the large enclosure. Signs of dental problems were subsequently observed in both bears, and so a dental examination was carried out, resulting in multiple extractions. After treatment, the amount of time that the bear with ongoing behavior problems spent stereotyping reduced significantly, and foraging increased. Our data suggest the bears' stereotypic behavior occurred not only in response to an understimulating environment in their old enclosure but also perhaps in association with medical conditions in one of the bears. Although other factors could have contributed to the observed reduction in stereotypy, it is clear that further investigation is needed into the effects of pain and physical condition on stereotypy in animals.  相似文献   
16.
Plant Foods for Human Nutrition - This study analysed fruits of cranberry cultivars: Ben Lear, Bergman, Early Richard, Pilgrim and Stevens and compared them with wild-grown cranberry fruits. The...  相似文献   
17.
Nanomaterials and particularly silver nanoparticles (AgNPs) have increased great interest in many fields of science. The element may affect plant growth and development but so far research studies have been scarce and their results disparate. Tulip is one of the most important ornamental plants and its production technology is constantly being improved. The aim of this study was to investigate the effects of AgNPs on growth and yield attributes of tulip cv. ‘Pink Impression’. Before planting, the tulip ‘Pink Impression’ bulbs were soaked in the following concentrations of AgNPs: 25, 50, 100 and 150?mg?L-1. Control bulbs were soaked in deionized water. The plants were forced in a greenhouse for two growing seasons. The tulips treated with 100?mg?L?1 AgNPs flowered earlier, had longer cut-flower stem, larger petals, greater stem diameter and cut-flower fresh weight. Moreover, at this concentration of AgNPs, they showed increased leaf greenness index (SPAD), stomatal conductance, root fresh weight, root length and produced daughter bulbs of the greatest weight. The study outcomes indicate that AgNPs may be used as plant growth promoters in horticulture.  相似文献   
18.
The objective of this study has been to determine the influence of food and ions on the pharmacokinetics of enrofloxacin (ENRO) in turkeys, administered per os at a dose of 10 mg/kg of body weight (b.w.). Co-administration of ENRO with ions or with food significantly retarded its absorption, and the interaction was more pronounced when the drug was given together with food. The bioavailability of ENRO was 65.78 ± 7.81% and 47.99 ± 9.48% with ions and food, respectively. The maximum concentration (Cmax) in plasma of animals exposed to ions reached 0.87 ± 0.26 μg/ml in a tmax of 2.07 ± 0.76 h; in animals which were fed while medicated, the analogous parameters were 0.36 ± 0.13 μg/ml and 8.06 ± 3.08 h. The PK/PD analysis demonstrated that a decrease in the concentration of ENRO in turkeys’ blood due to the interaction with ions or food might impair the drug's clinical efficacy toward some pathogenic microorganisms in turkeys if a routine dose of 10 mg ENRO/kg b.w. is administered.  相似文献   
19.
Journal of Soils and Sediments - The objective of this study was to evaluate the mutual relations between the soil organic matter (SOM) fractions: fulvic acids (FA), humic acids (HA), humins (HN),...  相似文献   
20.
Biotic interactions affect the impact of potential plant growth promoting microorganisms in the rhizosphere, but their magnitude and fundamentals are often hardly known. In a pot experiment, two physiologically different strains of the ectomycorrhizal fungus Paxillus involutus (GUL and FRA) were tested separately and in combination with associated bacteria (Sphingomonas paucimobilis 1 L, Ralstonia pickettii 16 B, Sphingomonas sp. 23 L) on their effects on the growth of willows (Salix viminalis). Both P. involutus strains significantly increased the growth of the willows compared with non-inoculated plants, but the magnitude of this effect was significantly affected by the fungal strain. The P. involutus strain GUL with higher synthesis of auxin-like substances, acid phosphatases, siderophores and faster utilisation of yeast extract in vitro increased the willow growth in situ more effectively than strain FRA. Additionally, dual inoculation with the P. involutus strains GUL and FRA in combination with the associated bacteria promoted the willow growth, especially the combination with S. paucimobilis 1 L. This bacterial strain used effectively C sources which are common components of plant root exudates, e.g. glucose, sucrose, maltose and mannose as well as compounds synthesized by fungi, e.g. trehalose in vitro. We conclude that the analyses of fungal metabolites and of C source use of associated bacteria can successfully contribute to accelerate the selection of capable plant growth promoting combinations.  相似文献   
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