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101.
In urban environments, trees are often faced with limiting physical factors at above- and below-ground levels. These factors include poor air quality, and water and soil pollution that may differ substantially from the natural environment. While numerous studies on urban climate and floristic analyses have been published, studies on the physiological performance and growth of trees in urban sites are rather scarce. They are often in contradiction with the general opinion of the growth's constraint. Generally, it is recognized that urban soils are made of poor landfill materials hampering soil water retention. Often, the soil is sealed by asphalted surfaces that prevent rain infiltration. Nevertheless, there is a gap of information to support the hypothesis by which such conditions determine plant water stress. This study will analyze the water relations and the performance of photosynthesis of Quercus ilex exemplars growing in three different conditions of urban green areas (urban park, outskirt/countryside and urban road) in the city of Florence (Italy) conducted in the year 2002. Results have evidenced a decline in photosynthetic rate in all three sites but a certain capacity of Q. ilex to acclimate to the harsh conditions of urban roads in terms of water relations, tissue elasticity and in photosystem efficiency that was higher at the beginning of summer.  相似文献   
102.
We examined fruiting behaviors of 24 dipterocarp species in a lowland rain forest of Peninsular Malaysia during two consecutive episodes of general flowering (GF). The first GF episode (GF2001) occurred from August 2001 to February 2002, and the second GF episode (GF2002) followed immediately, from March to September 2002. The magnitude of GF2002 was greater than that of GF2001 at the community level. Significant positive size dependence of fruiting behavior at the community level was found in both GF2001 and GF2002, but there was no significant association between the fruiting behaviors in GF2001 and GF2002 except for one species. These results imply that tree size was one of the explanatory factors for fruiting behavior of dipterocarp species, but there was no evidence that adjacent reproduction caused the absence of reproduction and decreased fecundity in the subsequent fruiting event. In contrast, strong spatial aggregation of fruiting trees was found in GF2001, suggesting that external factors may affect fruiting behavior of dipterocarps in a minor GF episode. Among the 12 study species, there were large variations in fruiting behavior, but growth type (e.g., fast-growing or slow-growing) did not simply explain the inter-specific pattern of fruiting behavior. Thus, tree size may account for fruiting behavior of dipterocarps during the consecutive GF episodes through species-specific differences in phonological responses to internal and external conditions.  相似文献   
103.
Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric ulcers due to inhibition of prostaglandin production. Prostaglandins have an influence on physiological gastrointestinal motility, but the relationships between NSAID-induced gastric ulcer, gastrointestinal motility and motilin are unknown. Fifteen dogs were allocated randomly to three groups in which either gelatin, meloxicam or indomethacin was administered. Fecal occult blood and gastrointestinal motility were monitored continuously for 6 days. In addition, analyses of the plasma motilin concentration, gastrointestinal endoscopy and gastric emptying, and detection of motilin cells were performed. Gastrointestinal motility was disturbed in the indomethacin group, presenting as disappearance of interdigestive migrating contractions (IMCs) 3 days before gastric ulcers were detected. Delayed gastric emptying and hypermotilinemia were observed significantly more often in the indomethacin group compared with the other groups. Motilin cell-crypt/villi ratio in the indomethacin group significantly decreased in the duodenum and jejunum, compared with the other groups. No significant changes in any tests were observed in the meloxicam group, when compared with the gelatin group. These findings suggest that the disturbance of IMCs caused by hypermotilinemia, with changes in motilin cell distribution, and delayed gastric emptying induced by indomethacin may contribute to the development of gastric ulcers.  相似文献   
104.
Fisheries Science - Our ultimate aim is to establish a small-bodied surrogate broodstock (e.g., mackerel) that produces functional gametes of the Pacific bluefin tuna Thunnus orientalis using...  相似文献   
105.
Amyloid protein was isolated from the cerebral meninges of 4 aged dogs with cerebral amyloid angiopathy. By immunoblot analysis, antiserum against synthetic oligo-peptide consisting of 1-28 amino acid of amyloid beta protein recognized prominent wide band ranging from 14 to 18 kilodalton (kd). When amyloid samples were solubilized by formic acid, the antiserum recognized lower molecular weight band ranging from 3 to 4 kd. Immunohistochemical studies on cerebral amyloid angiopathy and senile plaques were performed in 17 aged dogs. Anti-amyloid beta protein serum labeled amyloid deposits in cerebral vessel walls and senile plaques. Compact deposits of beta protein were detected in primitive or classical plaques. After using formic acid pretreatment, diffuse deposits of beta protein in the neuropil representing diffuse plaques were detectable. Classical and primitive plaques reacted with antiserum against glial fibrillary acidic protein, while not with antisera against alpha 1-antichymotrypsin, IgG and IgM. Amyloid deposits in the intestines of aged dogs examined, did not react with anti-amyloid beta protein serum.  相似文献   
106.
Polyphosphate kinase (PPK), encoded by the ppk gene, is a principal enzyme responsible for synthesis of inorganic polyphosphate (poly P) from ATP in many Gram-negative bacteria. In order to elucidate the functions of poly P in Pseudomonas syringae pv. tabaci 6605, an in-frame deletion mutant of the ppk gene (ppk) was constructed. The ppk mutant did not accumulate poly P, whereas the wild-type strain accumulated a large quantity. The mutant had reduced swarming motility, even though it retains swimming motility like the parental strain. The mutant exhibited increased sensitivity to prolonged incubation and environmental stresses, such as heat shock and oxidative stress and reduced exopolysaccharide (EPS) production compared to the wild-type. Northern blot analysis revealed that expression of the rpoS gene, encoding the stationary phase sigma factor RpoS, was reduced in ppk in the logarithmic phase, indicating that rpoS is regulated by the ppk gene. The poly P deficient mutant had significantly reduced ability to cause disease in its host tobacco plant and in planta growth of the mutant was also significantly reduced in host tobacco leaves as compared to the wild-type strain. Thus, our results suggest that poly P plays an important role in the virulence of P. syringae pv. tabaci 6605.  相似文献   
107.
Winter wheat scab in Hokkaido, Japan is caused predominantly by Gibberella zeae and Microdochium nivale and can result in significant yield losses. A selective medium for isolation of G. zeae was previously developed, but not for M. nivale. The purpose of this study therefore was to develop a selective medium for isolation of airborne spores of M. nivale. Based on the basic composition of Komada’s Fusarium-selective medium, carbon and nitrogen sources and the most suitable vitamin B component for the basal composition were examined. Hyphal growth of M. nivale was promoted when galactose was replaced with lactose and combined with L-asparagine, while aerial hyphal formation increased with thiamine hydrochloride as the vitamin B source. In antimicrobial composition, colony formation of other filamentous fungi was greatly inhibited by spiroxamine. Thiophanate methyl, to which M. nivale shows resistance, selectively inhibited the growth of Fusarium spp. only. Spore trapping using the selective medium was subsequently performed in a wheat field. M. nivale formed characteristic pinkish colonies on the selective medium in the case of contamination with other filamentous fungi, making differentiation easy. Overall, the findings show that LATTS medium developed in this study is effective for isolation of airborne spores of M. nivale.  相似文献   
108.
Three generations of a swine family produced by crossing a Japanese wild boar and three Large White female pigs were used to map QTL for various production traits. Here we report the results of QTL analyses for skeletal muscle fiber composition and meat quality traits based on phenotypic data of 353 F(2) animals and genotypic data of 225 markers covering almost the entire pig genome for all of the F(2) animals as well as their F(1) parents and F(0) grandparents. The results of a genome scan using least squares regression interval mapping provided evidence that QTL (<1% genome-wise error rate) affected the proportion of the number of type IIA muscle fibers on SSC2, the number of type IIB on SSC14, the relative area (RA) of type I on SSCX, the RA of type IIA on SSC6, the RA of type IIB on SSC6 and SSC14, the Minolta a* values of loin on SSC4 and SSC6, the Minolta b* value of loin on SSC15, and the hematin content of the LM on SSC6. Quantitative trait loci (<5% genome-wise error rate) were found for the number of type I on SSC1, SSC14, and SSCX, for the number of type IIA on SSC14, for the number of type IIB on SSC2, for the RA of type IIA on SSC2, for the Minolta b* value of loin on SSC3, for the pH of loin on SSC15, and for the i.m. fat content on SSC15. Twenty-four QTL were detected for 11 traits at the 5% genome-wise level. Some traits were associated with each other, so the 24 QTL were located on 11 genomic regions. In five QTL located on SSC2, SSC6, and SSC14, each wild boar allele had the effect of increasing types I and IIA muscle fibers and decreasing type IIB muscle fibers. These effects are expected to improve meat quality.  相似文献   
109.
ABSTRACT Fungal isolates from gray leaf spot on perennial ryegrass (prg isolates) were characterized by DNA analyses, mating tests, and pathogenicity assays. All of the prg isolates were interfertile with Triticum isolates and clustered into the crop isolate group (CC group) on a dendrogram constructed from rDNA-internal transcribed spacer 2 sequences. Since the CC group corresponded to a newly proposed species, Magnaporthe oryzae, all of the prg isolates were designated M. oryzae. However, DNA fingerprinting with MGR586, MGR583, and Pot2 showed that the prg isolates are divided into two distinct populations, i.e., TALF isolates and WK isolates. The TALF isolates were virulent only on Lolium species, whereas the WK isolates were less specific, suggesting that gray leaf spot can be caused not only by Lolium-specific isolates but also by less specific isolates. We designated the TALF isolates as Lolium pathotype. The TALF isolates showed diverse karyotypes in spite of being uniform in DNA fingerprints, suggesting that theyare unstable in genome organization.  相似文献   
110.
In Experiment 1, mature laying hens were inoculated intravaginally with 10(6) colony-forming units of Salmonella enterica serovar enteritidis (S. enteritidis), Salmonella typhimurium, Salmonella infantis, Salmonella hadar, Salmonella heidelberg, or Salmonella montevideo to compare their abilities to colonize the reproductive organs of chickens and to contaminate eggs. Salmonella enteritidis was more frequently recovered (from 11 of 40 eggs, 27.5%) than the other serovars, and especially the inner shell was contaminated with these organisms in 10 of 40 eggs (25.0%). The contamination rates and the viable counts in cloaca were significantly (P < 0.05) higher in hens inoculated with S. enteritidis than in those inoculated with the other serovars at 4 days postinoculation (PI). In the vagina, the positive rates were 90%-100% in hens inoculated with S. enteritidis, and the viable counts of the organisms in this portion were significantly (P < 0.05) higher than those of the other serovars at 2, 4, and 7 days PI. The ceca were colonized similarly by each serovar at 7 days PI. The spleen and ovary were infected with S. enteritidis in three and one hen, respectively. No Salmonella was recovered from liver and peripheral blood in any hen. Salmonella enteritidis was recovered from other oviductal portions than the vagina (10%-20%), whereas no forming egg was contaminated in the oviduct. In Experiment 2, the in vitro adherence of these six serovars to the vaginal epithelium was compared with vaginal explants. The mean number of S. enteritidis attaching to the secondary villi in the vaginal lumen was significantly (P < 0.05) higher than those of the other serovars. These results suggest that S. enteritidis has a specific advantage over the other Salmonella serovars by its capacity to colonize the vaginal tissues of hens, and this higher affinity of S. enteritidis to the vagina may play a significant role in the production of many S. enteritidis-contaminated eggs.  相似文献   
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