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A virological analyses of a sewage treatment plant which provided chlorinated, activated sludge treated sewage effluent to irrigate a complete two-year crop of sugarcane was made. The raw, the activated sludge treated and the chlorinated sewage effluent, as well as streams and a harbor receiving sewage effluents were concentrated by either the polymer two-phase, PE-60, Al(OH)3, protamine sulfate, or cellulose membrane method and assayed for human enteric viruses. Viruses were recovered from 100% (11/11) of the raw sewages tested at concentrations ranging from 27 to 19 000 PFU l?1 while 76% (13/17) of the activated sludge treated effluent was positive at concentrations ranging from 7 to 5222 PFU l?1. After chlorination, 58% (31/53) of the samples was positive for virus at concentrations ranging from 2 to 750 PFU l?1. Human enteroviruses were also isolated from shallow flowing streams at distances up to 3 mi (5 km) from the closest known sewage effluent discharge point and from a harbor approximately 0.5 mi (0.8 km) from the point of sewage discharge entering the harbor. The viruses most often isolated were echovirus 7, coxsackievirus B-4, B-5 and poliovirus 1, 2, and 3. These results indicate that although activated sludge treatment plus chlorination remove approximately 90% of the virus from the raw sewage, the final treated sewage effluent, which is normally discharged into a stream and in this experimental study to irrigate sugarcane, still contains a significant concentration of infectious viruses. Furthermore, the recovery of enteroviruses from waterways at points distant from the sewage treatment plants indicates that sewage-borne viruses persist in natural water environment. The significance of enteric viruses in waters accessible to the public and used for irrigation purposes remains to be determined.  相似文献   
3.
A modified malonaldehyde (MA) assay for antioxidant activity, which involves derivatization and headspace solid-phase microextraction (HS-SPME) was developed and validated. The recovery of MA as 1-methylpyrazole (product of MA and N-methylhydrazine) from a headspace of an aqueous solution containing MA, buffer, surfactant, and cod liver oil using HS-SPME with a PDMS/DVB fiber was 91.3 +/- 3.38%. MA was analyzed by a gas chromatograph with a nitrogen-phosphorus detector, and its detection limit was 0.0103 nmol/mL. The antioxidant activities of natural compounds were determined as the percentage inhibition of MA formed from cod liver oil oxidized by Fenton's reagents in the above aqueous solution. Sesamol inhibited MA formation most (86.1%), followed by eugenol (84.4%), capsaicin (80.7%), ethylvanillin (45.3%), and vanillin (31.6%) at a level of 50 microg/mL. This method did not require any organic solvents and is a simple, fast, and a highly sensitive method for MA determination.  相似文献   
4.
SUMMARY: The vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in the pelagic waters of Lake Biwa was evaluated from June to September in 1995–97 from eight acoustic surveys using a quantitative echosounder. In each survey, echoes from a depth range of 3 m to the sea bottom were collected at a station every 2.7 s for 24 h together with measurements of vertical profiles of water temperature and chlorophyll-a. The ayu's echoes were identified using an underwater video camera. The ayu were observed near the maximum chlorophyll-a depth and above the thermocline. Their density was highest at depths of 4–11 m with 2–4 individuals/m 3 and was almost zero below 20 m. Echo signs were recorded as having a frequent duration of more than 1 h at night, whereas were of a shorter duration in the day. The fish stay in the epilimnion during the day without any clear vertical migration, but are distributed more uniformly at night. The advantages of remaining in the epilimnion are discussed in terms of food availability and predator avoidance.  相似文献   
5.
The origins of the motor nerve fibers supplying the individual hindlimb muscles were elucidated in the fowl by the retrograde degeneration method. Chromatolytic cells were seen in the ipsilateral lamina 9 of the lumbosacral enlargement. Motoneurons innervating the individual hindlimb muscles were localized in the characteristic position of lamina 9. Both hip and thigh muscles are supplied by motoneurons of almost all the columns in lumbar segments and by those of dorsolateral columns in sacral segments, while the shank and foot muscles are supplied by motoneurons of ventromedial columns in sacral segments. The origins of the dorsal cord of the lumbosacral plexus are situated laterally in the lamina 9 and those of the ventral cord are located medially in it.  相似文献   
6.
Surveillance of the distribution of sand fly species is important for prediction of the risk and expansion of Leishmania infection in endemic and surrounding areas. In the present study, a simple and reliable method of typing New World Lutzomyia species circulating in endemic areas in Ecuador was established by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique. PCR-RFLP of 18S ribosomal RNA (rRNA) genes with the restriction enzyme AfaI and subsequently HinfI successfully identified seven sand fly species in nine endemic areas in Ecuador. Although intraspecific genetic-diversity affecting the RFLP-patterns was detected in a species, the patterns were species specific. The method promises to be a powerful tool for the classification of New World Lutzomyia species.  相似文献   
7.
Estimating carbon (C) and nitrogen (N) stocks in deadwood in forests nationwide is required for understanding large-scale C and N cycling. To do so requires estimated values of wood density and C and N concentrations. Additionally, parameters that show variation should be examined. In this study, we clarified the estimated values and the variation in three parameters in each decay class of each of two tree species and examined whether dead log diameter and region contribute to variation in the parameters. Data were collected from 73 Chamaecyparis obtusa (Sieb. et Zucc.) Endl. plantations and 66 Cryptomeria japonica D. Don plantations throughout Japan. Wood densities decreased from 386 to 188?kg?m?3 for C. obtusa and from 334 to 188?kg?m?3 for C. japonica in decay classes 1–4. The variation in wood density increased with decay class, and the coefficient of variance increased from 13.9% to 46.4% for C. obtusa and from 15.2% to 48.1% for C. japonica. The N concentrations increased from 1.04 to 4.40?g?kg?1 for C. obtusa and from 1.11 to 2.97?g?kg?1 for C. japonica in decay classes 1–4. The variation in N concentration increased with decay class, and the coefficient of variance increased from 51.9% to 76.7% for C. obtusa and from 50.3% to 70.4% for C. japonica. Log diameter and region contributed to variations in wood density and N concentration in decay classes 1 and 2 for C. obtusa and C. japonica. However, no relationship was observed between regional climates and the two parameters. In contrast, C concentrations ranged from 507 to 535?g?kg?1 and were stable with much lower coefficients of variance throughout the decay classes for both tree species. Thus, we recommend that the same C concentration can be adapted for all decay classes of both tree species.  相似文献   
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9.
Human immunodeficiency virus (HIV) infects lymphocytes and macrophages via CD4 and chemokine receptors. In this study, the infectivity of a chimeric simian and human immunodeficiency virus (SHIV) having a CCR5-specific HIV-1 envelope gene was examined. A SHIV strain termed SHIV-JRFL could enter cells via CD4 with a chemokine receptor CCR5, not CXCR4, and the viral replication was suppressed by recombinant human RANTES, one of beta-chemokines. The intravenous inoculation of SHIV-JRFL into two rhesus macaques resulted in a systemic infection, though it was rather weak. During the early infection, the production of RANTES from Con A-stimulated PBMCs of the infected monkeys increased. These results suggested that beta-chemokine has the potential to limit the infectivity of an R5-type SHIV.  相似文献   
10.
Nineteen analogues were synthesized by modifying the tert-butylhydrazine moieties of N'-tert-butyl-N'-(3,5-dimethylbenzoyl)-5-methyl-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide and N'-tert-butyl-N'-(3,5-dimethylbenzoyl)-5-methylchromane-6-carbohydrazide (chromafenozide), and the synthesized analogues were evaluated for their insecticidal activity against Spodoptera litura F. While all of the synthesized analogues had insecticidal activity inferior to those of the lead compounds, several of the analogues nonetheless showed high insecticidal activity. Chromafenozide has shown very high selectivity toward lepidopteran species.  相似文献   
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