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1.
The effect of phosphine at exposure periods of 24, 48 and 120 h on hatching and mortality of 0- to 1-day-old eggs of susceptible (TN6) and resistant (FC10) strains of Rhyzopertha dominica of field origin was investigated. The fumigant affected hatching in both the strains. In a 48-h exposure at 27 (+/- 2) degrees C, the LD99 doses for the eggs of TN6 and FC10 were 0.56 and 3.25 mg litre-1, respectively. Significant reduction in hatching was observed in treated batches with progressive increase of phosphine dose in the first 2-3 days. On subsequent days the numbers hatching were often similar to those in controls, and sometimes exceeded control hatch, especially following a 5-day exposure. A critical change in the order of susceptibility of egg and adult stages of the two strains was noticed. In 48-h exposures, eggs of the susceptible strain were more tolerant than their adults, whilst the reverse was true in the resistant strain.  相似文献   
2.
Antibacterial compounds from the flowers of Alangium salviifolium   总被引:2,自引:0,他引:2  
1-Methyl-1H-pyrimidine-2,4-dione and 3-O-beta-D-glucopyranosyl-(24beta)-ethylcholesta-5,22,25-triene, isolated from the flowers of Alangium salviifolium, showed remarkable antibacterial activities against a number of Gram-positive and Gram-negative bacterial species.  相似文献   
3.
Formation of a Reservoir of Sperm in the Oviduct   总被引:2,自引:0,他引:2  
A reservoir of sperm in the initial segment of the oviduct has been found in several species of domestic and laboratory mammals. Evidently, the reservoir serves to ensure successful fertilization by providing the appropriate number of sperm in the appropriate physiological state for fertilizing oocytes soon after they enter the oviduct. Recent evidence indicates that sperm are trapped in the reservoir by binding to specific carbohydrate moieties on the surface of the mucosal epithelium of the oviduct. A bovine seminal plasma protein has been identified that associates with sperm and confers on them the capacity to bind to the carbohydrate moiety.  相似文献   
4.
A new diterpenoid, 15-angeloyloxy-16,17-epoxy-19-kauronic acid (1), along with five known metabolites, 16-kauren-19-oic acid (2), 6′-hydroxy-2′,3′,4,4′-tetramethoxychalcone (3), isosakuranetin (4), acacetin (5), and kaempferide (6) was isolated from the organic extracts of the roots of Chromoleana odorata. Their structures were determined by spectroscopic evidences. The structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction studies. Compound 2 exhibited significant α-glucosidase inhibitory and antibacterial activities against Escherichia coli and Bacillus subtilis.  相似文献   
5.
6.
1. The concentrations of 17 beta-oestradiol (E2) and progesterone (P) were determined in the plasma of layer breeder hens at the end of their first laying season, in relation to neoplasms of the oviduct, including magnum tumours and leiomyomas. 2. The plasma concentration of E2 was higher in tumorous than in non-tumorous hens indicating it may be involved in the development of oviduct tumours. 3. The plasma concentrations of P in tumorous and non-tumorous hens were not significantly different, suggesting no active role of P in the aetiology of the tumours. 4. The E2: P ratio was higher in tumorous than in non-tumorous hens. This ratio could be of value in predicting hens at risk of developing oviduct tumours.  相似文献   
7.
8.
Transboundary animal diseases (TADs) are highly contagious and have the potential to spread very rapidly irrespective of the national borders, causing serious economic losses. These diseases cause high morbidity and mortality in susceptible animal populations. Furthermore, the extent of their consequences may significantly affect the food security and national economics. In Pakistan, the main TADs include rinderpest, peste des petits ruminants, foot and mouth disease and avian influenza. In the present paper the status of these diseases in Pakistan is discussed.  相似文献   
9.
In the present study, embryogenic calli of sugarcane variety BL4 were induced using 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin in different concentrations and combinations. In contrast to earlier studies, embryogenic callus sectors were identified and isolated microscopically within 1–2 weeks. Subsequently, 51 media formulations were used for regeneration of proliferated embryogenic callus, using MS medium supplemented with three different cytokinins [kinetin, 6-Benzylamino purine (BAP), and thidiazuron (TDZ)] and auxins (IAA/NAA and IBA) in different combination and concentrations. After acclimatization, the genomic DNA of regenerated plants was studied to explore the insertion polymorphism of transposable elements in order to ascertain the variation among somaclones. Though low concentration of kinetin with 2,4-D was found supportive to embryogenic callus development, the highest number of regenerated plantlets was observed using BAP (1 μM), however the plantlets had very low fresh weight (2.2 g). Conversely, TDZ alone supported a significant increase in the number of plantlets regenerated (38–40) with higher fresh weight. The somaclones generated during this study showed considerable positional polymorphism of activator-like transposable elements possibly due to the stress associated with in vitro culture. This study provides a procedure to produce regenerated sugarcane plants from embryogenic callus in a relatively short time.  相似文献   
10.
Recent data from the European and Hungarian Antimicrobial Resistance Monitoring Systems have indicated that the routine use of gentamicin in human and veterinary medicine frequently leads to the selection of gentamicin resistance in Escherichia coli. The aim of this study was to provide molecular characterization of gentamicin resistance in clinical and commensal E. coli strains representing humans and food producing animals by genotyping for antimicrobial resistance and virulence using a miniaturized microarray. All 50 strains tested proved to be multidrug resistant defined as resistance to three or more antimicrobial classes. Antimicrobial resistances genes such as aadA1-like, strB, bla(TEM), sul1 and tet(A) or tet(B), and corresponding phenotypes (streptomycin-, ampicillin-, sulfamethoxazole- and tetracycline resistance) were detected in >50% of isolates regardless of the host or clinical background. However, certain genes encoding gentamicin resistance such as aac(6')-Ib and ant(2″)-Ia as well as catB3-like genes for phenicol resistance were only detected in human isolates. Among virulence genes, the increased serum survival gene iss was predominant in all host groups. Although the majority of gentamicin resistant E. coli strains were characterized by diverse antimicrobial resistance, and virulence gene patterns, accentuated links between catB3-like, aac(6')-Ib, bla(CTX-M-1) and sat genes could be detected in human strains. Further resistance/virulence gene associations (tet(A) with iroN and iss) were detected in poultry strains. In conclusion, the simultaneous characterization of antimicrobial resistance and virulence genotypes of representative clinical and commensal strains of E. coli should be useful for the identification of emerging genotypes with human and or animal health implications.  相似文献   
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