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71.
Abstract – The spawning behavior of male and female largemouth bass Micropterus salmoides (Lacépède) was studied in central Illinois during the spring of 1998 to examine patterns of muscular activity associated with different spawning related behaviors and to evaluate whether electromyogram (EMG i ) telemetry could be used to detect spawning activity. Fish were implanted with EMG i transmitters (8 females, 16 males) on April 7, prior to the initiation of spawning, and were released in four 0.10-ha earthen research ponds. Continuous EMG i records, underwater videography and additional visual observations for one pair of EMG i tagged fish were collected throughout the entire spawning event, allowing us to quantify behavioral correlates of physical activity. Male EMG i activity patterns were only correlated with female patterns during courting and periods of male aggression toward the female. Overall, EMG i activity was highest for the female during shuddering (gamete deposition), whereas male EMG i activity was similarly high during periods of nest excavation, shuddering and post-spawn parental care activities. During spawning, female EMG i activity was positively correlated to shuddering. Average daily EMG i activities for females peaked on the day of spawning. As a result of their engagement in parental care activities, male activity continued to rise even after spawning was completed. EMG i telemetry appears to be a useful technique for monitoring the reproductive activity of largemouth bass, especially in areas of high cover or turbid water or during low light conditions. This technology permitted us to quantify and contrast the activity patterns associated with different spawning related activities, information that will be required to construct accurate, gender-specific bioenergetics models for this species. 相似文献
72.
Molecular epidemiology of avian pathogenic Escherichia coli (APEC) isolated from colisepticemia in poultry 总被引:6,自引:0,他引:6
The molecular biology and epidemiology of 150 avian pathogenic Escherichia coli strains (APEC) isolated from septicemic poultry in Germany was investigated by serotyping, pulsed field gel electrophoresis (PFGE), and polymerase chain reaction (PCR). Only 49.6% of the isolates could be grouped to serogroups O1, O2, and O78. Macrorestriction analyses data revealed two large clonal groups (clusters I and II) among the APEC strains with a similarity of 60.9% to each other. An association between restriction pattern and serogroup or origin of the strains was only present in a few subgroups of each clusters I and II, but was not evident. In contrast, our data revealed distinct combinations of virulence-associated genes in that 51.2% of the O2-strains harboured a combination of the genes fyuA, irp2, iucD, tsh, vat, fimC, and colV and 36.4% of the O78-strains possessed the same gene combination with exception of vat. With 34 different gene combinations the non-O1, -O2, -O78 isolates revealed a higher variability in their virulence gene pattern than O1-, O2-, and O78-strains with 6, 13, and 9 patterns, respectively. Our data indicate only a limited association between the virulence gene pattern and the serogroup of APEC strains and question the sensitivity of O-typing for APEC identification without the application of further diagnostic tools. Although a limited number of APEC clones exist, horizontal gene transfer seems to be common in these pathogens. These findings strengthen further research on the population structure of APEC and may be the reason for the lack of clear definition of this common E. coli pathotype. 相似文献
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Jennifer Eiermann BVSc Kristin Kirkby-Shaw DVM MS PhD DACVS-SA DACVSMR CCRT Richard B. Evans PhD Sebastian C. Knell Dr med vet DECVS Michael P. Kowaleski DVM DACVS DECVS Philipp A. Schmierer Dr med vet DECVS Mary S. Bergh DVM DACVS DACVSMR Jason Bleedorn DVM MS DACVS Laura C. Cuddy MVB MS DACVS-SA DECVS DACVSMR DECVSMR MRCVS Nina R. Kieves DVM DACVS-SA DACVSMR CCRT Peter Lotsikas DVM DACVS DACVSMR Antonio Pozzi DVM MS DACVS DECVS DACVSMR 《Veterinary surgery : VS》2020,49(1):80-87
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Ahmad Fakhro Susanne von Bargen Martina Bandte Carmen Büttner Philipp Franken Dietmar Schwarz 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(4):579-590
As Pepino mosaic virus has become a pathogen of major importance in worldwide tomato production, information is needed on possible differences between
the sensitivity of cultivars towards infection. Furthermore, it is important what hosts other than Solanaceae may be virus reservoirs and are, therefore, threats for tomato cultivation. Two PepMV isolates (PepMV-Sav, E397, a European
tomato isolate and PV-0554, a Peruvian pepino isolate) differing in their origin and virulence were used for several experiments
to investigate these issues. The response to mechanical inoculation with PepMV was studied using 25 tomato cultivars, seven
indicator plant species, and nine other possible horticultural host plants. Symptom development after infection with PepMV
was monitored and the virus was detected by DAS-ELISA and IC-RT-PCR. Garlic and broad bean were shown to be additional hosts
of PepMV depending on the virus isolate. Nicotiana benthamiana seems to be the most sensitive indicator among all tested indicator plants developing symptoms. Both PepMV isolates infected
all tested tomato cultivars. Development of disease symptoms depended on the cultivar and the virus isolate but symptoms were
not visible in all cases. None of the cultivars showed tolerance against the two isolates but two responded with a lower susceptibility
at an absorbance level of 0.2 (healthy control 0.09). It was observed that some cultivars grown hydroponically showed also
lower losses in biomass and yield. Data indicated a correlation between absorbance level in DAS-ELISA and reduction in total
tomato growth. 相似文献
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Chloroplast DNA (cpDNA) restriction site analysis of nine species of Daucus (covering four of five sections) and nine carrot
accessions was done using 14 Petunia cpDNA clones as probes and 10 restriction enzymes. Cladistic analysis yielded a phylogeny
generally concordant with a recent morphological classification. A cpDNA insertion-deletion mutation was found in the cultivated
carrots (probe P10– Bgl II digest). Mitochondrial DNA (mtDNA) restriction site analysis of the same material using four maize
mtDNA clones as probes and 10 enzymes exhibited extensive mitochondrial diversity in Daucus, both within and between sections.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献